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BACKGROUND OF THE INVENTION
The invention relates to a radiation-polymerizable mixture which contains as the essential constituents:
(a) a polymeric binder,
(b) an acrylic or alkacrylic acid derivative polymerizable by free radicals and having a boiling point above 100° C. under normal pressure and
(c) a compound or a combination of compounds, which is capable of initiating the polymerization of the compound (b) under the action of actinic radiation.
The mixture is suitable in particular for the preparation of photoresists, especially those which can be prepared and processed by the dry resist process.
Mixtures of the above-mentioned type are known. In U.S. Pats. No. 3,887,450 and No. 3,953,309, photopolymerizable mixtures for use in the dry resist process are described, which can be developed with aqueous-alkaline solutions and, as the polymerizable compounds, preferably contain exclusively those having two or more polymerizable ethylenically unsaturated groups.
Similar mixtures are known from European Patent Application No. 128,014, which additionally contain a mono-unsaturated polymerizable compound, especially an aryloxypolyalkoxyalkyl (meth)acrylate. This addition is intended to improve the flexibility, tackiness and developability of the layers; stripping of the exposed layer areas is thus also facilitated.
German Offenlegungsschrift No. 3,441,787 has disclosed mixtures of the same type and applicability, which contain mono-unsaturated or polyunsaturated monomers, of which at least one contains an aromatic OH, SH or sulfonamide group. These mixtures are distinguished in particular by ready strippability after exposure.
In dry photoresist layers, it is generally customary to use monomers which contain urethane groups. Mixtures of this type are described, for example, in U.S. Pats. No. 3,850,770, No. 4,019,972, No. 4,088,498, No. 4,250,248 and No. 4,387,139. In all these cases, the mixtures contain polyunsaturated compounds, in most cases di-unsaturated compounds.
U.S. Pat. No. 3,783,151 has disclosed similar mixtures based on polyunsaturated polymerizable compounds which contain urethane groups and which are used for the preparation of radiation-curable surface coatings and printing inks. The urethane groups can be introduced by reaction with monovalent or polyvalent isocyanates. If monovalent isocyanates are employed, they are always reacted with polyunsaturated monomers, for example with pentaerythritol triacrylate.
The dry photoresist materials described above and containing monofunctional unsaturated compounds admittedly have improved flexibility and strippability in the exposed state. However, they have other disadvantages which restrict their usefulness in practice. Thus some of the monomers tend to crystallize, and in other cases the exposed layers are unduly brittle or have inadequate adhesion to copper in the unexposed state.
DISCLOSURE OF THE INVENTION
It is therefore an object of the invention to provide a radiation-polymerizable mixture which has good flexibility, developability and strippability after exposure.
It is another object of the invention to provide a mixture, as above, which has reduced brittleness and improved adhesion to copper compared to known radiation polymerizable mixtures.
It is yet another object of the invention to provide a radiation-polymerizable recording material incorporating the above mixture.
Still another object of the invention is to provide a process for the preparation of relief recordings using the recording material.
According to the invention, a radiation-polymerizable mixture is proposed which contains as the essential constituents:
(a) a polymeric binder,
(b) an acrylic or alkacrylic acid derivative polymerizable by free radicals and having a boiling point above about 100° C. under normal (atmospheric) pressure, and
(c) a compound or a combination of compounds, which is capable of initiating the polymerization of the compound (b) under the action of actinic radiation.
In the mixture according to the invention, the acrylic or alkacrylic acid derivative is a compound of the formula I ##STR2## in which
A is 0, NH or N-alkyl,
Q is --CO--C p H 2 p--Z-- or --C k H 2k O--,
Z is 0 or NH,
R 1 is H or alkyl,
R 2 is alkyl, alkenyl, cycloalkyl, aryl, aralkyl or SO 2 R 3 ,
R 3 is alkyl, alkenyl, cycloalkyl, aryl, aralkyl or aryloxy,
k is a number from 3 to 20,
l is a number from 0 to 20,
m is a number from 2 to 20,
n is a number from 1 to 20 and
p is a number from 2 to 10.
The invention also encompasses a radiation-polymerizable recording material with a flexible transparent temporary support and a transferable thermoplastic radiation-polymerizable photoresist layer which contains the essential constituents:
(a) a polymeric binder,
(b) acrylic or alkacrylic acid derivative polymerizable by free radicals and having a boiling point above 100° C. under normal pressure, and
(c) a compound or a combination of compounds, which is capable of initiating the polymerization of the compound (b) under the action of actinic radiation, and, if appropriate, a cover sheet, which can be peeled off, on the free side of the photoresist layer and which adheres less strongly to the layer than the temporary support.
In the recording material according to the invention, the acrylic or alkacrylic acid derivative is a compound of the formula I ##STR3## in which A is O, NH or N-alkyl,
Q is --CO--C p H 2 p--Z-- or --C k H 2k O--,
Z is O or NH,
R 1 is H or alkyl,
R 2 is alkyl, alkenyl, cycloalkyl, aryl, aralkyl or SO 2 R 3 ,
R 3 is alkyl, alkenyl, cycloalkyl, aryl, aralkyl or aryloxy,
k is a number from 3 to 20,
l is a number from 0 to 20,
m is a number from 2 to 20,
n is a number from 1 to 20 and
p is a number from 2 to 10.
The invention also proposes a process for the production of relief recordings, wherein a dry, solid, radiation-polymerizable photoresist layer contains as the essential constituents:
(a) a polymeric binder,
1 (b) an acrylic or alkacrylic acid derivative polymerizable by free radicals and having a boiling point above 100° C. under normal pressure, and
(c) a compound or a combination of compounds, which is capable of initiating the polymerization of the compound (b) under the action of actinic radiation.
The photoresist layer is attached to a flexible transparent temporary support, laminated under pressure and with heating to a final support and is irradiated imagewise. The temporary support is peeled off, and the unirradiated layer areas are washed out with a developer.
In the process according to the invention, the photoresist layer contains, as the acrylic or alkacrylic acid derivative which can be polymerized by free radicals, a compound of the formula I ##STR4## in which A is O, NH or N-alkyl,
Q is --CO--C p H 2p --Z-- or --C k H 2k O--,
Z is O or NH,
R 1 is H or alkyl,
R 2 is alkyl, alkenyl, cycloalkyl, aryl, aralkyl or SO 2 R 3 ,
R 3 is alkyl, alkenyl, cycloalkyl, aryl, aralkyl or aryloxy,
k is a number from 3 to 20,
l is a number from 0 to 20,
m is a number from 2 to 20,
n is a number from 1 to 20 and
p is a number from 2 to 10.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Monofunctional polymerizable compounds, including also those of the above formula I, are known per se and are described as constituents of photocurable coating compositions, surface coatings or adhesives, for example in U.S. Pats. No. 3,957,561, No. 4,111,769, No. 4,227,980, No. 4,424,100 and No. 4,439,600 and in European Patent Applications No. 36,813 and No. 37,314. Among these known compounds, those of the formula I corresponding to the definition given above are suitable for use in the mixture according to the invention.
In the general formula I, R 1 is preferably a hydrogen atom or a methyl group.
R 2 preferably has at least 4 carbon atoms. If R 2 is an alkyl or alkenyl radical, this radical preferably has 4 to 12 carbon atoms in a straight chain. Preferred cycloalkyl radicals are those which have 5 or 6 ring members and which can be unsubstituted or substituted by alkyl or alkoxy groups having 1 to 3 carbon atoms. The aryl radicals employed are in particular substituted or unsubstituted phenyl radicals. Possible substituents are preferably alkyl, alkoxy or alkylenedioxy groups having 1 to 4 carbon atoms.
R 3 is preferably an alkyl, aryl or aryloxy radical, in particular an alkyl radical having 2 to 8 carbon atoms or a mononuclear aryl or aryloxy radical having 6 to 10 carbon atoms.
If A is an N-alkyl group, this preferably has 1 to 6 carbon atoms.
Particularly preferably, A and Z are oxygen atoms.
Preferably, k is a number from 3 to 10, in particular from 3 to 6; l is preferably 0 to 10; m is preferably 2 to 10, in particular 2 to 4; n is preferably 1 to 15, particularly preferably 1 to 10; and p is preferably 3 to 6.
The preferred monofunctional monomers should be virtually non-volatile under the preparation and storage conditions for the mixture and not crystallize during storage of the mixture.
Examples of suitable monomers are the reaction products of isocyanates with hydroxyethyl acrylate or methacrylate or with the reaction products obtained by reaction of hydroxyethyl (meth)acrylate with alkylene oxides or lactams or lactones of aminocarboxylic or hydroxycarboxylic acids, for example caprolactam or caprolactone.
The reaction product of hydroxyethyl methacrylate with tert.-butyl isocyanate is less preferable, since it tends to volatility in most mixtures.
The reaction products of hydroxyethyl methacrylate with halogenated phenyl isocyanates, such as 4-chloro- or 3-chloro-4-methyl-phenyl isocyanate, or with naphthyl isocyanates are also not preferable because of their tendency to crystallize.
In addition to the monofunctional monomers, the mixtures according to the invention can contain polymerizable compounds with at least two terminal ethylenic double bonds. In general, esters of acrylic or methacrylic acid with polyhydric, preferably primary, alcohols are used as the polyfunctional compounds of this type. Examples of suitable polyhydric alcohols are ethylene glycol, propylene glycol, butane-1,4-diol, butane-1,3-diol, diethylene glycol, triethylene glycol, polyethylene glycols or polypropylene glycols with molecular weights from about 200 to 1,000, neopentyl glycol, trimethylolethane, trimethylolpropane, pentaerythritol and oxyethylated bisphenol A derivatives. Bis-acrylates and bis-methacrylates which contain urethane groups and which are obtained by the reaction of diisocyanates with partial esters of polyhydric alcohols and, if appropriate, diols or polyols are also suitable. Such monomers containing urethane groups are described in German Offenlegungsschriften No. 2,064,079, No. 2,361,041 and No. 2,822,190. Similar monomers have been disclosed in German Offenlegungsschrift No. 3,048,502.
The total quantity of polymerizable compounds in the mixture according to the invention is in general 25 to 75 and preferably 40 to 60% by weight, relative to the non-volatile constituents of the mixture. The proportion of monofunctional monomers is in general 5 to 100, preferably 20 to 95 and particularly preferably 55-95% by weight, relative to the total quantity of polymerizable compounds.
A large variety of substances can be used as the polymerization initiators, which can be activated by radiation, in particular actinic light, in the mixture according to the invention. Examples are benzoin and its derivatives, trichloromethyl-s-triazines, heterocyclic compounds with carbonylmethylene groups containing trihalogenomethyl groups, for example 2-(p-trichloromethyl-benzoylmethylene)-3-ethyl-benzo-thiazoline, acridine derivatives, for example, 9-phenyl-acridine, 9-p-methoxyphenyl-acridine, 9-acetyl-amino-acridi and benzo(a)acridine, phenazine derivatives, for example 9,10-dimethyl-benzo(a)phenazine and 10-methoxybenzo(a)phenazine, quinoxaline derivatives, for example 6,4',4"-trimethoxy-2,3-diphenylquinoxaline and 4',4"-dimethoxy-2,3-diphenyl-5-azaquinoxaline, or quinazoline derivatives. The initiators are generally employed in a quantity from 0.01 to 10 and preferably from 0.05 to 4% by weight, relative to the non-volatile constituents of the mixture.
A wide variety of soluble organic polymers can be employed as the binders. Examples which may be mentioned are polyamides, polyvinyl esters, polyvinyl acetals, polyvinyl ethers, epoxide resins, polyacrylates, polymethacrylates, polyesters, alkyd resins, polyacrylamide, polyvinyl alcohol, polyethylene oxide, polydimethylacrylamide, polyvinylpyrrolidone, polyvinylmethylformamide, polyvinylmethylacetamide and copolymers of the monomers forming the homopolymers enumerated.
Natural substances or modified natural substances, for example gelatine and cellulose ethers, can also be used as the binders.
With particular advantage, binders are used which are water-insoluble but soluble or at least swellable in aqueous-alkaline solutions, since layers with such binders can be developed with the preferred aqueous-alkaline developers. Binders of this type can, for example, contain the following groups: --COOH, --PO 3 H 2 , --SO 3 H, --SO 2 NH--, --SO 2 --NH--SO 2 -- and --SO 2 --NH--CO--.
The following may be mentioned as examples of these: maleate resins, polymers of β-(methacryloyloxy)-ethyl N-(p-tolyl-sulfonyl)-carbamate and copolymers of these and similar monomers with other monomers, as well as styrene/maleic anhydride copolymers. Alkyl methacrylate/methacrylic acid copolymers and copolymers of methacrylic acid, alkyl methacrylates and methyl methacrylate and/or styrene, acrylonitrile and others, such as described in German Offenlegungsschrift No. 2,064,080 and No. 2,363,806, are preferred. More specifically, the former German patent document discloses binders, preferred in the present invention, that are copolymers of methacrylic acid and at least one alkyl methacrylate, with molecular wieght generally ranging from 20,000 to 200,000, wherein the alkyl group with 4 to 15 carbon atoms. One such copolymer is a terpolymer from (a) methacrylic acid, (b) methyl methacrylate or ethyl methacrylate and (c) an alkyl methacrylate with 4 to 15 carbon atoms in the alkyl group. Suitable copolymers can also be prepared only from methacrylic acid and a higher alkyl acrylate, but in this case the alkyl group generally should not contain more than eight carbon atoms.
German Offenlegungsschrift No. 2,363,806 discloses copolymeric binders, likewise preferred in the present invention, that are comprised of:
(A) an unsaturated carboxylic acid,
(B) an alkyl methacrylate with at least 4 carbon atoms in the alkyl group, and
(C) an additional monomer which is capable of copolymerization with monomers (A) and (B) and which has a corresponding homopolymer characterized by a glass transition temperature of at least 80° C., preferable at least 100° C.
Suitable components (c) of the terpolymer include styrene or substituted styrene, e.g., vinyl toluene, p-chlorostyrene, α-chlorostyrene, α-methylstyrene, vinly ethyl benzene, o-methoxystyrene, or m-bromostyrene; vinyl napthalene and substituted vinly naphthalene; heterocyclic vinyl compounds, e.g., N-vinlyl carbazole, vinyl pyridine, or vinyl oxazole; vinyl cycloalkanes, e.g., vinyl cyclohexane and 3,5-dimethyl-vinyl cyclohexane; acrylamide methacrylamide, N-alkylacrylamide, acrylonitrile, methacrylonitrile, aryl methacrylate, aralkyl methacrylate, and others. Preferred terpolymers of this type are those in which component (C) is styrene, p-chloro-styrene, vinyl toluene, vinyl cyclohexane, acrylamide, methacrylamide, N-alkylacrylamide, phenyl methacrylate, acrylonitrile, methacrylonitrile, or benzyl methacrylate, styrene being preferred. Higher-molecular copolymers, such as are described in the earlier German Patent Application P 3,427,519, are particularly preferred. The higher molecular copolymers disclosed in the German application are prepared by mass polymerization and, generally, have mean molecular weights in the range from about 65,000 to 150,000. They are comprised of (i) 20 to 60 mole-% of acrylic acid or methacrylic acid; (ii) 25 to 80 mole-% of an alkyl methacrylate having at least 4 carbon atoms in the alkyl group, a homopolymer of said methacrylate (ii) having a glass transition temperature of not more than 20° C.; and (iii) up to 30 mole-%, preferably between 3 and 20 mole-%, of a monomeric ethylenically unsaturated compound which is copolymerizable with said acid (i) and said methacrylate (ii), a homopolymer of said compound (iii) having a glass transition temperature of at least 80° C.
The quantity of the binder is in general 25 to 75 and preferably 40 to 60% by weight of the constituents of the mixture.
As conventional further constituents, the mixture can contain polymerization inhibitors, hydrogen donors, sensitometric regulators, dyes, pigments, plasticizers, and cross-linking agents which can be activated thermally.
As the actinic radiation, to which the mixture according to the invention is sensitive, any electromagnetic radiation can be employed, the energy of which is sufficient for initiating polymerization. Visible and ultraviolet light, X-rays and electron beams are particularly suitable. Laser radiation in the visible and ultraviolet regions can also be used. Short-wave visible light and near ultraviolet light are preferred.
Suitable supports for the recording materials prepared with the mixture according to the invention are, for example, aluminum, steel, zinc, copper, screens or plastic films, for example of polyethylene terephthalate. The support surface can be pretreated chemically or mechanically, in order to adjust the adhesion of the layer to the correct level.
The mixture according to the invention is preferably used as a photoresist material which can be transferred dry. For this purpose, it can be applied in a known manner as a prefabricated, transferable dry resist film to the workpiece which is to be processed, for example to printed circuit board base material. To prepare the dry resist material, a solution of the mixture in a solvent is in general applied to a suitable support, for example a polyester film, and dried. The layer thickness of the resist layer can be about 10 to 80 and preferably 20 to 60 /um. The free surface of the layer is preferably covered by a cover film, for example of polyethylene or polypropylene. The finished laminate can be stored as a large roll and cut up to resist rolls of any desired width when required.
The films can be processed in any apparatus customary in the dry resist technology. The cover film is peeled off in a commercially available laminating device and the photoresist layer is laminated onto a copper-clad base material. The plate thus prepared is then exposed through an original and, after the support film has been peeled off, developed in the known manner.
Examples of suitable developers are aqueous, preferably aqueous-alkaline solutions, for example solutions of alkali metal phosphates, carbonates or silicates, to which, if appropriate, small quantities, for example up to 10% by weight, of water-miscible organic solvents or wetting agents can be added. If binders are used which are insoluble in aqueous alkaline solutions, organic solvents, for example trichloroethane, are also used.
The mixtures according to the invention can be employed in the most diverse fields of application. With particular advantage, they are used in the form of a dry resist film for the preparation of resists, i.e., etch resist layers or plating resists, on metallic supports, for example copper.
In this application, the outstanding elasticity and toughness of the photoresist layers prepared from the mixture according to the invention manifest themselves both in the unexposed state and in the exposed state. The photopolymerizable layer laminated to copper is so firmly coherent that the unsupported layer areas covering the holes remain undamaged when the carrier film is severed, and are not carried away with this film. Using layers prepared from the mixture according to the invention, it is possible to bridge holes of 6 mm in diameter and larger,the layer remaining undamage when the film is severed, when the layer is developed and when the bared areas are electroplated and/or etched.
Compared with known dry resist layers having exclusively difunctional or polyfunctional monomers, the layers prepared from the mixtures according to the invention have the advantage of better adhesion to copper, of reduced brittleness in the exposed state and of easier strippability after processing. As compared with known dry resist layers which contain both monofunctional and polyfunctional monomers, they have better adhesion to copper in the exposed and unexposed state and--as compared with some of these known mixtures--a lower tendency to crystallize.
The mixtures according to the invention give layers of high flexibility in the unexposed and exposed states, so that the resist templates produced from them can be readily and reliably corrected or retouched. The layers can be developed in a short time, to leave no residue, and, on stripping in the light-cured state, form smaller blobs or particles. In contrast to most of the known dry resist materials containing monofunctional monomers, it is possible to employ with advantageous results those mixtures according to the invention which exclusively contain monofunctional monomers.
These layers have the advantage that after removal (stripping) in the exposed state they completely dissolve in the stripping solution after some time, i.e., do not leave any undissolved blobs or particles behind. It is therefore also possible to use alkaline stripping solutions of lower concentration, i.e., for example 2% instead of 5% potassium hydroxide solution, with substantially the same effect.
The exposed resist templates also withstand aggressive processing solutions, for example gold baths, and show good resistance to developers.
The mixtures according to the invention form dry resist layers, the shear viscosity of which in the unexposed state is less dependent on atmospheric humidity than that of known comparable dry resist materials.
Apart from the dry resist process, the mixture according to the invention is also suitable for other applications, where flexibility and toughness of the light-sensitive layer are important, as for example for the preparation of photoresist solutions, printing forms, relief images, screen-printing templates and color proofing sheets.
The examples which follow illustrate the preferred embodiments of the mixture according to the invention and their applications. Unless otherwise stated, percentage figures and quantitative ratios are to be understood as weight units. Parts by weight (p.b.w.) and parts by volume (p.b.v.) have the same relationship as grams and cm 3 .
EXAMPLE 1
The following 5 coating solutions were prepared:
______________________________________5 p.b.w. of a terepolymer of methyl methacrylate, n-hexyl methacry- late and methacrylic acid (5:60:35) having a mean molecu- lar weight M.sub.W = 70,000,1.1 p.b.w. of a diurethane obtained from 2 moles of hydroxyethyl methacry- late and 1 mole of 2,2,4-tri- methyl-hexamethylene-diisocyanate,3.9 p.b.w. of a further polymerizable com- pound as indicated below,0.05 p.b.w. of 9-phenyl-acridine and0.01 p.b.w. of a blue azo dye obtained by coupling 2,4-dinitro-6-chloro- benzenediazonium salt with 2-methoxy-5-acetylamino-N,N- diethylaniline, in16 p.b.w. of butanone and4 p.b.w. of ethanol.______________________________________
The individual further polymerizable compounds used were:
(a) the reaction product of hexapropylene glycol monomethacrylate and phenyl isocyanate,
(b) the reaction product of hexapropylene glycol monomethacrylate and m-tolyl isocyanate,
(c) the reaction product of 1 mole of hydroxyethyl acrylate, 2 moles of caprolactone and 1 mole of n-butyl isocyanate,
(d) the reaction product of diethylene glycol monomethacrylate and butyl isocyanate or
(e) the reaction product of 2 moles of hydroxyethyl methacrylate and 1 mole of 2,2,4-trimethylhexamethylene diisocyanate (comparison).
The solutions were whirler-coated onto biaxially stretched and thermofixed polyethylene terephthalate films of 25 /μm thickness, in such a way that a layer weight of 45 g/m 2 was obtained in each case after drying at 100° C.
Dry resist films thus prepared were laminated by means of a commercially available laminating device at 115° C. to phenoplast laminate boards clade with 35 /μm thick copper foil and exposed for 4 seconds by means of a 5 kW metal halide lamp at a distance of 110 cm between the lamp and the vacuum copying frame. The original used was a line pattern with line widths and spacings down to 80 /μm.
After exposure, the polyester films were peeled off and the layers were developed for 60 seconds with 1% sodium carbonate solution in a spray development apparatus.
The flexibility of the cured resist layers was tested in accordance with DIN 53,232. Using a combtype crosscut tool, parallel cuts at 1 mm spacing were scribed through the resist layer in one direction and in a second direction at 90° thereto. A pressure-sensitive adhesive tape was then firmly pressed down on the layer surface in the cut area and peeled off at a defined force and rate. The flexibility and adhesion of the layer, the appearance of the cut edges and the percentage of cut squares detached from the support were then evaluated. Rating was on a scale from Gt 0 to Gt 4, Gt 0 meaning completely clean, undamaged cut edges and 0% detachment, and Gt 4 meaning pronounced splintering of strips along the cut edges and at least 65% detachment of cut squares.
Whereas the resist layers (a) to (d) were flexible (Gt 0), the comparison layer (e) was brittle (Gt 4). The flexibility of the resist is an important property which plays a role, inter alia, in the event of a possible retouching or correction.
In a further test, plates prepared and developed as above were rinsed for 30 seconds with tap water, incipiently etched for 30 seconds in a 15% ammonium peroxidisulfate solution, rinsed again with water, immersed for 30 seconds in 10% sulfuric acid and then electroplated successively in the following electrolyte baths:
1. Sixty minutes in a copper electrolyte bath from Messrs. Schloetter, Geislingen/Steige, of the "Glanzkupferbad" type
Current density: 2.5 A/dm 2
Metal coating: about 30 /μm
Temperature: room temperature
2. 15 minutes in a lead/tin bath LA from Messrs. Schloetter, Geislingen/Steige
Current density: 2 A/dm 2
Metal coating: 15 /μm
Temperature: room temperature
The plates did not show any undercutting or damage whatsoever.
The electroplated plates were stripped in 2% potassium hydroxide solution at 50° C. The following times were required for stripping, the first figure in each case indicating the time in seconds up to the start of stripping and the second figure indicating the time up to the end of stripping:
(a) 45-70 (b) 45-65 (c) 65-100 (d) 50-80 (e) 95-150
It will be seen that the stripping time is substantially shortened by the addition of the monofunctional monomers. At the same time, a reduction in the size of the particles formed is observed. This means that the resist can be removed without problems even from narrow channels between conductor tracks.
EXAMPLE 2
Solutions of the following composition were whirler-coated onto 3 polyester films of the type indicated in Example 1, in such a way that after dying a layer weight of 30 g/m 2 was obtained in each case:
______________________________________5 p.b.w. of the terpolymer indicated in Example 1,x p.b.w. of the reaction product of 2 moles of hydroxyethyl methacrylate and 1 mole of 2,2,4-trimethyl-hexa- methylene diisocyanate,y p.b.w. of the reaction product of 1 mole of hydroxyethyl acrylate, 2 moles of caprolactone and 1 mole of n- butylisocyanate,0.05 p.b.w. of 9-phenyl-acridine,0.006 p.b.w. of the blue azo dye from Example 1 and0.024 p.b.w. of the green dye 1,4-bis-(4- tert.-butoxy-phenylamino)-5,8- dihydroxy-anthraquinone in25 p.b.w. of butanone and5 p.b.w. of ethanol.______________________________________
The quantitative proportions of the monomers in the individual mixtures were as follows:
(a) X=2; y=3 (b) x=1.1; y=3.9 (c) x=0.5; y=4.5
The materials were processed as in Example 1. In the exposed state, all the resist layers were flexible. For stripping in 2% potassium hydroxide solution at 50° C., the following times (seconds) were required: (a) 45-60 (b) 25-30 (c) 15-20
The dependence of the stripping time on the quantitative proportion of monofunctional monomers is clearly evident.
EXAMPLE 3
Dry resist materials were prepared with coating solutions according to Example 2, containing the following quantities of monomers:
______________________________________x p.b.w. of the bifunctional monomer indi- cated in Example 2,y p.b.w. of the reaction product of hexapropylene glycol monomethacry- late and m-tolyl isocyanate______________________________________
(a) x=2; y=3 (b) x=1.1; y=3.9 (c) x=0.5; y=4.5
For stripping in 2% potassium hydroxide solution at 50° C., the following times in seconds were required:
(a) 35-45 (b) 25-30 (c) 15-25
EXAMPLE 4
A coating solution of
______________________________________5 p.b.w. of the terpolymer indicated in Example 1,5 p.b.w. of the reaction product of 1 mole of hydroxyethylacrylate, 2 moles of caprolactone and 1 mole of n- butyl isocyanate,0.05 p.b.w. of 9-phenyl-acridine,0.006 p.b.w. of the blue azo dye from Example 1 and0.024 p.b.w. of the green dye 1,4-bis-(4- tert.-butoxy-phenylamino)-5,8- dihydroxy-anthraquinone in15 p.b.w. of butanone and5 p.b.w. of ethanol.______________________________________
was whirler-coated onto the polyester film described in Example 1 in such a way that a layer weight of 30 g/m 2 was obtained after drying at 100° C. The layer was laminated to a phenoplast laminate plate clad with a 35 /μm thick copper foil. It was then exposed for 6 seconds with a metal halide lamp through a negative original of a track pattern and, after peeling off the support film, developed for 60 seconds with 1% sodium carbonate solution.
The bared copper surfaces were removed by means of a copper chloride etch solution containing ammonia and the resist was stripped with 5% potassium hydroxide solution at 50° C. A good etching result was obtained. The stripping time was 25 to 55 seconds, and the particles initially formed had dissolved completely in the stripping solution after about 12 hours. The good developer resistance of the resist layer, which exclusively contains a monofunctional monomer as the polymerizable compound, is particularly surprising.
To determine the developer resistance, an exposure for 6 seconds was made through a 13-step exposure wedge with density steps of 0.15 and development with 1% sodium carbonate solution was then carried out until the unexposed areas had been just completely removed (t a ). The number of step wedges found was compared with that obtained at three times the developing time (3×t a ):
______________________________________ t.sub.a 3 × t.sub.a______________________________________step wedges 8 (9) 8______________________________________
EXAMPLE 5
Dry resist materials with 38 /μm thick resist layers were prepared by whirler-coating the solutions indicated below onto polyester films and subsequent drying:
______________________________________5.6 p.b.w. of the terpolymer indicated in Example 1,3.1 p.b.w. of the monomer from Example 4,1.3 p.b.w. of one of the polyglycol bismethacrylates indicated below,0.05 p.b.w. of 9-phenyl-acridine,0.006 p.b.w. of the blue azo dye according to Example 1 and0.024 p.b.w. of the green anthraquinone dye according to Example 2 in15 p.b.w. of butanone and5 p.b.w. of ethanol.______________________________________
The bifunctional monomer employed was (a) the bis-methacrylate of a polypropylene glycol of molecular weight 420 and in the other case (b) the corresponding ester of a polyethylene glycol of molecular weight 400. The photoresist layers were processed as described in Example 1. 30-70 seconds in case (a) and 35-60 seconds in case (b) were required for stripping after electroplating.
In a further test series, dry resist materials according to (a) and (b) were laminated to copper-clad test plates with holes of between 1 and 6 mm diameter and exposed through a negative original corresponding to the holes (diameter of the transparent areas 1.4 to 6.4 mm). The unexposed layer areas were then washed out with 1% sodium carbonate solution and the bared copper was etched away with copper chloride solution containing ammonia. After etching, all the holes were bridged by cured photo-resist.
EXAMPLE 6
As described in Example 1c and 5a, dry resist materials were prepared, laminated to copper-clad plates of insulating material, exposed and developed. The structured plates obtained were then electroplated as follows:
(1.) 60 minutes in a copper electrolyte bath from Messrs. Blasberg, Solingen, of Cuprostar LP 1" type Current density: 2.0 A/dm 2 Metal coating: about 24 /μm Temperature: room temperature
(2.) 15 minutes in a nickel bath of "Norma" type from Messrs. Schloetter, Geislingen/Steige Current density: 3.5 A/cm 2 Metal coating: 12 /μm Temperature: 50° C.
(3.) 10 minutes in an "Autronex CC" type gold bath from Messrs. Blasberg, Solingen Current density: 1.0 A/dm 2 Metal coating: 3 /μm Temperature: room temperature
The plates did not show any undercutting or damage.
EXAMPLE 7
The procedure followed was as in Example 1, but in each case one of the following was employed as the monofunctional polymerizable compound:
(a) the reaction product of hydroxyethyl methacrylate and n-butyl isocyanate,
(b) the reaction product of 1 mole of hydroxyethyl methacrylate, 2 moles of caprolactone and 1 mole of n-butyl isocyanate,
(c) the reaction product of hexapropylene glycol monomethacrylate and n-butyl isocyanate.
Results similar to those in Example 1 were obtained with the resulting dry resist materials.
EXAMPLE 8
A dry resist material was prepared in accordance with Example 1c. For comparison, another otherwise identical material was prepared which, instead of the monofunctional monomer from Example 1c, contained the same quantity of the reaction product of 1 mole of hydroxyethyl acrylate and 2 moles of caprolactone. The materials were laminated to copper as in Example 1, exposed for 6 seconds and developed. The flexibility and adhesion of the unexposed layers were tested as in Example 1. The developer resistance was also tested as in Example 4.
The table which follows shows the results:
______________________________________ Developer resistance, wedge stepsResist Adhesion to Cu t.sub.a t.sub.a × 3______________________________________1 c Gt 0 8 (9) 8Comparison Gt 4 6 (7-9) 4 (5-8)______________________________________
Apart from markedly poorer adhesion, the comparison layer is conspicuous by the large number of partially cross-linked steps and by the poorer developer resistance.
EXAMPLE 9
Coating solutions of the following compositions were prepared:
(a)
______________________________________5 p.b.w. of the terpolymer indicated in Example 1,1.1 p.b.w. of the bifunctional monomer indi- cated in Example 1,3.9 p.b.w. of the reaction product of diethy- lene glycol monomethacrylate and n-butyl isocyanate,0.05 p.b.w. of 9-phenyl-acridine and0.016 p.b.w. of the blue azo dye indicated in Example 1 in16 p.b.w. of butanone and4 p.b.w. of ethanol,______________________________________
(b) the same solution as under (a), but wherein the monofunctional monomer was replaced by the samwe quantity of phenoxyethoxethyl acrylate (comparison),
(c) the same solution as under (a), but wherein the monofunctional monomer was replaced by the same quantity of hydroquinone monomethacrylate (comparison),
(d) (comparison)
______________________________________5 p.b.w. of the terpolymer indicated in Example 1,5 p.b.w. of a commercially available solu- tion of 65 p.b.w. of a bisacrylate containing urethane groups in 35 p.b.w. of phenoxyethyl acrylate (Laromer LR 8642x from BASF AG),0.05 p.b.w. of 9-phenyl-acridine and0.016 p.b.w. of the blue azo dye indicated in Example 1 in16 p.b.w. of butanone and4 p.b.w. of ethanol,______________________________________
(e) (comparison)
______________________________________40 p.b.w. of the terpolymer indicated in Example 1,12 p.b.w. of trimethylolpropane triacrylate,10 p.b.w. of phenoxyethoxyethyl acrylate,0.312 p.b.w. of 9-phenyl-acridine and0.096 p.b.w. of the blue azo dye indicated in Example 1 in100 p.b.w. of butanone and25 p.b.w. of ethanol.______________________________________
The solutions were whirler-coated onto polyester films of the type indicated in Example 1 and dried; the layer weight was 45 g/m 2 in each case. The dry resist material were then laminated in a commercially available laminator at 115° C. to copper-clad plates of insulating material. The adhestion of the unexposed layers was tested by the cross-cut test described in Example 1. The table which follows shows the results.
______________________________________ a b c d e______________________________________Adhesion Gt 0 >Gt 4 >Gt 4 >Gt 4 >Gt 4______________________________________
On storage, the monofunctional monomer crystallized out of the layer (c).
EXAMPLE 10
A coating solution consisting of
______________________________________5 p.b.w. of the terpolymer indicated in Example 1,1.5 p.b.w. of the bismethacrylate indicated in Example 1,3.5 p.b.w. of the monofunctional monomer indicated in Example 1c,0.05 p.b.w. of 9-phenyl-acridine and0.01 p.b.w. of the blue azo dye indicated in Example 1 in16 p.b.w. butanone and4 p.b.w. of ethanol______________________________________ was whirler-coated onto a polyester film as in Example 1 and dried. Two dry resist films prepared as described above were laminated to one another in a laminating apparatus. After a support film had been peeled off, a further resist layer was applied and finally a fourth resist layer was combined with the others by lamination.
In the second test, the procedure followed was as above, but the monofunctional monomer in the coating solution was replaced by the same quantity of the bismethacrylate indicated therein (comparison). A sandwich laminate with a resist layer of four times the thickness was also prepared from this material in the same manner as above.
Samples of the two laminates were each stored at 0% and at 53% relative humidity. The shear viscosity (in MPa.s) at 40° C. was then measured on these samples. The ratio of the shear viscosities at 0%/53% relative humidity was 1.7 for the material according to the invention; in the comparison test, the corresponding ratio was 4.5. The test shows that the dependence of the shear viscosity of the unexposed resist layer, which is a measure of the cold flow of the layer, on the atmospheric humidity is substantially smaller in the case of the material according to the invention than in the case of the material without a monofunctional monomer. | A radiation-polymerizable mixture, recording material and process for using the recording material in relief recordings. The radiation-polymerizable mixture contains:
(a) a polymeric binder,
(b) a compound of the formula: ##STR1## `in which A is O, NH or N-alkyl,
Q is --CO--C p H 2p -Z-- or --C k H 2k O--,
Z is O or NH,
R 1 is H or alkyl,
R 2 is alkyl, alkenyl, cycloalkyl, aryl, aralkyl or SO 2 R 3 ,
R 3 is alkyl, alkenyl, cycloalkyl, aryl, aralkyl or aryloxy,
k is a number from 3 to 20,
l is a number from 0 to 20,
m is a number from 2 to 20,
n is a number from 1 to 20 and
p is a number from 2 to 10, and
(c) a compound or a combination of compounds, which is capable of initiating the polymerization of the compound (b) under the action of actinic radiation.
The mixture is especially suitable for the preparation of dry photoresist materials and is distinguished by good flexibility and adhesion to copper and by easy strippability in the light-cured state. | 8 |
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application claims priority from U.S. provisional application No. 61/333,643 filed 11 May 2010; entitled High Volume Pump having low hydrostatic head. The entire contents being hereby included by reference and for which benefit of the priority date is claimed.
FIELD OF THE INVENTION
[0002] The present invention is directed toward a rotary kinetic energy fluid pump having a high volume while maintaining a low hydrostatic head.
BACKGROUND OF THE INVENTION
[0003] In systems similar to those filed in U.S. patent application Ser. No. 11/387,405 entitled “Electrical generation from low temperature thermal energy” and patent application Ser. No. 12/517,421 “Air conditioning by vapor compression and expansion”, there can be a need, depending upon configuration, to move substantially high volumes of fluid through a solar collector efficiently in order to collect solar energy for converting into work. It is anticipated that these systems will be deployed in situations where the system is off the grid. This means that energy required to run the system will need to be generated by the system.
[0004] The preferred system will be able to circulate large volumes of water or fluid while consuming a small amount of work energy.
[0005] The solar collectors are preferably designed to have large flow channels with a small flow resistance, therefore requiring a low head pressure to create sufficient flow. Further it is desired due to cost constraints and maintainability that the pump circuit be low pressure to minimize hose and joint expansion, use lower grade fittings and materials etc. The walls of the solar collectors may be formed from flat (not curved or tube) polymers. Such collector walls are not designed to withstand much pressure, and don't need to if a low flow resistance is achieved.
[0006] In such systems, as the water is heated, the saturation pressure (or fugacity) increases. If the pump produces a vacuum or suction at the inlet of the pump so that the absolute pressure at the inlet is less than the saturation pressure, the pump can go into cavitation. The efficiency of the pump is greatly diminished even to the point that it can stop pumping fluid, which can cause the solar collectors to overheat either locally or systemically. The present application discloses new and innovative pump design to minimize and prevent this cavitation and subsequent overheating.
SUMMARY OF THE INVENTION
[0007] In accordance with the present invention, there is provided in at least one embodiment, a pump providing water flow of between 60-70 gallons per minute through a set of solar panels comprising approximately 900 square foot solar collection surface area using only 50-70 watts to run the pump. These panels, at peak operation, can output typically between 30-40 kWatts of heat energy. Water temperatures up to 185° F. have been pumped in an unpressurized system without concern for cavitation.
[0008] It is therefore an object of the invention to provide a high output flow rates with low hydrostatic head.
[0009] It is therefore an object of the invention to pump high temperature water at low pressures without cavitation.
[0010] It is another object of the invention to pump fluids with little input energy.
[0011] It is another objective of the invention to have a pump which has low capital and operating costs.
[0012] It is another objective of the invention to provide a pump which protects the solar collectors from overheating.
BRIEF DESCRIPTION OF THE DRAWINGS
[0013] A complete understanding of the present invention may be obtained by reference to the accompanying drawings, when considered in conjunction with the subsequent, detailed description, in which:
[0014] FIG. 1 shows a schematic view of a version of a heat pump and heat engine embodiment requiring a pump of the present invention;
[0015] FIG. 2 shows a schematic view detailing the heat exchanger portion of the heat engine from the embodiment shown in FIG. 1 ;
[0016] FIG. 3 shows a schematic view detailing the heat exchanger portion of the heat pump from the embodiment shown in FIG. 1 ;
[0017] FIG. 4A shows a top perspective view of an input portion of an embodiment of a pump impeller of the present invention;
[0018] FIG. 4B shows a through view of a side of an embodiment of a pump impeller of the present invention;
[0019] FIG. 4C shows a bottom perspective view of an output portion of an embodiment of a pump impeller of the present invention;
[0020] FIG. 5A shows a perspective view from the center for an (nth) section of the impeller shown in FIG. 4 ;
[0021] FIG. 5B shows a perspective view of the (nth) section of 5 A rotated approximately 45 degrees clockwise;
[0022] FIG. 5C shows a perspective view of the (nth) section of 5 A rotated approximately 60 degrees counterclockwise;
[0023] FIG. 5D shows a partially through orthogonal view of the face of 5 B;
[0024] FIG. 5E shows a partially through orthogonal view of the face of 5 C;
[0025] FIG. 6 in general shows the combination of two sections (n) (n−1) from FIG. 5 which illustrates the interdigitated nature of the sections spanning (n) (n−1) (n−2) and (n−3) channels and focusing primarily on input characteristics;
[0026] 6 A- 6 C and 6 E contains two sections joined (n) and (n−1) and shows a top right, bottom right, face on and back on view(s) of the sections;
[0027] FIGS. 6D and 6F shows through views of the (n) and (n−1) sections;
[0028] FIG. 7 focuses mostly on the outlet characteristics of a section;
[0029] FIGS. 7A-7B shows a perspective top view of an outlet;
[0030] FIG. 7 D shows a perspective bottom view of an outlet;
[0031] FIG. 7C , shows a partial through perspective view of an outlet;
[0032] FIG. 7E shows a partial through orthogonal view of an outlet;
[0033] FIG. 7F shows a through perspective view of an outlet;
[0034] FIG. 8 shows a schematic representation of the inflection point of the impeller of the pump between acceleration/compression and deceleration/expansion with pressure conversion.
DETAILED DESCRIPTION
[0035] A system which incorporates aspects of a pump of the current design is shown in FIG. 1 . A solar collector ( 100 ) for such a system would preferably be designed such that a pump ( 10 ) for providing large volume of fluid flow across a heat exchanger ( 250 ) of the heat engine evaporator would be advantageous in order to act as a nearly constant temperature heat source into the heat engine chamber ( 716 ). Various heat exchangers may be deployed ( 250 ) ( 350 ) ( 450 ) ( 550 ), as shown in FIGS. 2 and 3 , in order to further segregate various fluids to the various working channels of the HE and HP in order to maximize properties of each.
[0036] Care should be taken to keep the vapor pressure of the liquid connecting rod (LCR) fluid from exceeding the total pressure of the working fluid, resulting in a possible rapid transfer of heat and mass (vapor of the LCR fluid) from the LCR fluid to the working chamber as a result of boiling of the LCR fluid. If the LCR fluid is physically separated from the working chamber, the higher pressure of the LCR fluid vapor can cause separation or dislocation of the physical separation means from the LCR liquid fluid. This may have the potential to damage the physical separation means and/or interfere with the proper operation of the cycle by reducing the volume of the chamber. Therefore the heat source, heat sink, and ambient temperatures under consideration, should be kept even and controlled so as not to become an issue.
[0037] FIGS. 4A-4C show a pump rotor ( 10 ) having a hub ( 12 ) for rotating on a spindle, in the case of 4 A, in a counter clockwise rotation. This embodiment is designed to have a high inlet or throat area ( 14 ) relative to the area of the feed pipe (not shown). As the rotor ( 10 ) turns, the inlet face ( 11 ) spins about an axis or hub ( 12 ) imparting momentum onto the fluid in the same direction as the rotation of the inlet face ( 11 ). Thus the fluid flowing in the feed pipe continues to flow into the rotor inlet with minimal disruption. While the impeller will operate over a range of rotational velocity it is preferred that the inlet face ( 11 ) move at approximately two times the rotational velocity of the adjacent fluid at the inlet face. Under these conditions, a relatively low amount of suction is produced because of the large inlet throat area and gentle slope of the receding face ( 18 ). As the fluid is drawn into the throat area it eventually meets a guiding face ( 30 ) which can also be seen as the opposing surface to the receding face ( 18 ), which along with the shroud ( 26 ) and the compressing face ( 24 ) form a channel through-which the fluid flows. As the fluid is accelerated by kinetic energy, which by application of the Bernoulli's principle results in an overall decrease in localized pressure, the compressing face ( 24 ) following the general direction of acceleration acts to reduce the cross sectional area of the flow channel which slightly increases pressure on the otherwise incompressible fluid roughly in balance with the Bernoulli's equation for decrease in pressure, thus resulting in a minimization of cavitation.
[0038] FIGS. 5 through 6 show an (n), (n−1), and (n−2) section(s) depending upon the view which highlight the actual flow through the channels which are nested or interdigitated one with another. Using the throat edge ( 14 ) as a reference, the fluid is accelerated and flows along the receding face ( 18 ) of the channel while the cross sectional area is minimized at the minimal port area ( 32 ) which then flows under the (n+1) section and expands until flowing to the output port ( 34 ).
[0039] As an alternative way of illustration shown in FIG. 8 , the fluid starts in an acceleration zone ( 40 ) where the fluid is accelerated by addition of kinetic energy due to the rotation of the throat edge ( 14 ) and compressing face ( 16 ) in a counterclockwise direction. A portion of the fluid is then scooped between the throat edge ( 14 ) and the trailing edge ( 20 ) and the compression face ( 24 ) and shroud ( 22 ) of the input where it flows toward an inflection point ( 44 ) where it continues to be accelerated and slightly compressed as the cross sectional volume decreases due to the compression face. The fluid reaches an inflection point ( 44 ) where the face recedes and becomes an expansion face ( 17 ) and to a deceleration zone ( 42 ) where the fluid is decelerated and the kinetic energy previously imparted to the fluid is converted to pressure. The zones ( 40 ) and ( 42 ) and compression face ( 16 ) and expansion face ( 17 ) in drawing 8 were exaggerated for teaching. The principles controlling actual acceleration and deceleration for minimization of cavitation are discussed below.
[0040] In another way of viewing the current system, as each channel passes by a point in space, a section of liquid is “scooped” off and the liquid continues to flow into the next channel. This is a simplification since the fluid is swirling in the feed pipe above the rotor inlet. The net effect is the differential between the “Bernoulli velocity” as denoted in the table below which measures an angular velocity of the fluid, and the “Outer Port Rotor Velocity” integrated with the “Inner Port Rotor Velocity” which provides, for example, an Outer Relative Velocity”. For example, if the Bernoulli velocity of the fluid is 68 inches per second, and the Outer Port of the Rotor is traveling at 182 inches per second; the Outer Relative Velocity becomes; (182−68=114 inches per second) which provides an understanding of the rate at which fluid at the inlet is “scooped” off to flow through the channel. While somewhat empirical, this model has provided predictable results when matched with mechanical measurements.
[0041] Relative to a fixed point, the fluid in each rotor channel is accelerated in the direction from the entrance of the channel to the outlet of the channel opposite the direction of the pressure or head development across the pump because the exit pressure is higher than the inlet pressure. However the fluid flow velocity component along the channel flow path at the channel inlet is designed to be approximately 37% of the velocity of the rotor channel. Thus relative to the rotor, the fluid flows through the rotor channel from the inlet of the channel to the exit of the channel, causing flow from the lower pressure inlet to the higher pressure outlet.
[0042] Since the fluid in the free stream in the feed pipe has little to no component of velocity in the direction of the rotor rotational velocity (only along the axial direction of the tube), the action of the rotor causes the fluid flow velocity to increase in the direction from the exit of the channel to the inlet of the channel. This adds energy to the fluid. As the fluid passes through the rotor channel, the area of the rotor channel increases and thus the velocity of the fluid decreases, converting the flow energy into pressure per Bernoulli's equation. In the preferred embodiment, the decrease in the rotor channel area is designed to provide a constant deceleration rate of the fluid as it flows through the channel.
[0043] This embodiment currently does not use a seal at the outer diameter of the rotor. The radial clearance is set for an acceptable flow loss between the outer diameter of the rotor and the inner diameter of the pump housing.
Preferred Embodiment
[0044] Design perimeters for one embodiment of the present invention can be shown in the table below:
[0000]
Design Parameter
Element
Value
Unit
Housing OD
5.5
inch
Housing Wall
0.24
inch
Pipe ID
5.02
inch
Pipe Area, Inside
19.79
in{circumflex over ( )}2
Desired Clearance Radial
0.01
inch
Shroud OD
5.00
inch
Design Flow Rate
70
gpm
Number of Ports
10
ports
Design Rotor Speed
720
rpm
Design Differential Pressure
6
inch water
Bernoulli velocity
68.03
in/sec
Average Axial Flow
13.62
in/sec
Specific gravity
1
(water)
Port Outer Radius
0.085
inch
Port Width
0.85
inch
Port Inner Radius
1.5650
inch
Port Height
0.4
inch
Port Area
0.34000
in{circumflex over ( )}2
Section Thickness
0.48
in
Outer Port Rotor Velocity
182
in/sec
Inner Port Rotor Velocity
118
in/sec
Outer Relative Velocity
114
in/sec
Inner Relative Velocity
50
in/sec
Flow Rate per Port
27.9
in{circumflex over ( )}3/sec
Outer Port Chord Length
1.52
in
Inner Port Chord Length
0.98
in
Port to Port Time
0.0083
seconds
Axial Flow, Per Port
51.01
in{circumflex over ( )}3/sec
Minimum Hub Diameter
1.25
in
Max Port Width
1.79
in
[0045] This embodiment currently does not use a seal at the outer diameter of the rotor. The radial clearance as defined above is set for an acceptable flow loss between the outer diameter of the shroud and the inner diameter of the pump housing.
CONCLUSION, RAMIFICATIONS, AND SCOPE
[0046] Although the present invention has been described in detail, those skilled in the art will understand that various changes, substitutions, and alterations herein may be made without departing from the spirit and scope of the invention in its broadest form. The invention is not considered limited to the example chosen for purposes of disclosure, and covers all changes and modifications which do not constitute departures from the true spirit and scope of this invention.
[0047] For example, although the foregoing refers to applications for high flow, low head flows used in solar energy collection, it is contemplated that the present invention could be used for other high flow applications.
[0048] Further, compressor face and channel details may vary from application to application in terms of dimensions and number and position of structural members.
[0049] In other embodiments there may be differing ratios of throat opening to constriction values at the inflection point.
[0050] Having thus described the invention, what is desired to be protected by Letters Patent is presented in the subsequent appended claims. | A pump for providing high volume flows with a low hydrostatic head. The pump is particularly suited for heated fluids such as those from a solar collector and the like. | 5 |
FIELD OF THE INVENTION
The present invention relates to a process for preparing improved latex compositions, and the improved latices thereby produced. More particularly, the present invention relates to a process for preparing latices from various polymers and specifically from conjugated diene butyl rubber. Still more particularly, the present invention relates to a process for preparing latices from adducts of conjugated diene butyl rubber and particular dienophiles, such as maleic anhydride. The present invention also relates to improved latex compositions, and more particularly improved latex films produced thereby.
BACKGROUND OF THE INVENTION
The preparation of a latex from certain polymers, such as butyl rubber and sulfobutyl rubber is known. Thus, aqueous suspensions of such materials have herebefore been prepared, employing various emulsifying agents and stabilizers, and latex products have been prepared from these emulsions for use as adhesives and as bonding agents for various fibers, etc. While such processes are known, the preparation of artificial latices, particularly from polymers containing acidic functionality, and their neutralized counterparts, has been difficult. These particular polymers, and their neutralized analogues, e.g., the sodium salts of sulfobutyl rubbers, are very difficult to emulsify. They require mixed solvent systems to effect solubilization, very specific emulsifiers, and are very susceptible to inversion to water in oil emulsions during finishing.
It is therefore an object of the present invention to provide a novel process for preparing latices of ionomeric polymers containing carboxylate functionality in a simple and uncomplicated manner.
In order better to understand the significance of this invention, however, it is necessary to review first the development of the polymers which form the base for this new latex.
Butyl rubber is produced by the copolymerization of an isoolefin such as isobutene with a conjugated multiolefin such as isoprene or butadiene. While butyl rubber has been a highly successful commercial product, various modified forms of butyl rubber containing greater degrees of unsaturation have been sought. Thus, Ser. No. 228,727, filed on Feb. 23, 1972 in the name of Francis P. Baldwin and Alberto Malatesta, now U.S. Pat. No. 3,816,371, and Ser. No. 228,728, also filed on Feb. 23, 1972 in the name of Francis P. Baldwin, now U.S. Pat. No. 3,775,387, respectively disclose a conjugated diene butyl rubber and a method for preparing same. These applications thus disclose the dehydrohalogenation of halogenated butyl rubber in order to produce a conjugated diene butyl rubber containing conjugated diene unsaturation. The conjugated diene butyl rubber thus produced, as described and claimed in Ser. No. 228,727, which is incorporated herein by reference, is represented by the general formula: ##EQU1## wherein n + 1 represents the number of isoolefin units incorporated in the butyl rubber, and m represents the number of initial diolefin units present, though other structures may be present, for example the structure: ##EQU2##
Further, several methods for preparing such conjugated diene butyl rubber are disclosed in Ser. No. 228,727, and these methods are also incorporated herein by reference. Additionally, other conjugated diene structures derivable from generic butyl rubber are disclosed in Ser. No. 465,479, filed on Apr. 30, 1974.
As stated above, it is therefore an object of the present invention to provide an uncomplicated method of preparing latices from such polymers and the resulting modified analogues occurring from the Diels-Alder addition of a dienophilic anhydride. It is another object of this invention to provide improved latices for use, in films, as adhesives, bonding agents, paper coatings, etc.
SUMMARY OF THE INVENTION
It has now been discovered that improved latices can be prepared from polymers containing acidic functionality, such as copolymers of an isoolefin containing from 4 to 7 carbon atoms and a conjugated multiolefin containing from 4 to 14 carbon atoms, wherein a major portion of said conjugated multiolefin has conjugated diene unsaturation, by the steps of forming an adduct of the copolymer and a dienophile capable of implanting carboxylic acid functionality on the polymer, such as a dienophilic anhydride, dissolving the polymer in a suitable solvent to form a cement, emulsifying the cement thus formed with an appropriate amount of water and an emulsifier to an average particle size of from 1 to 10 microns, and neutralizing the raw emulsion thus formed with a suitable base, stripping off the solvent and concentrating the finished latex.
The ionomeric latices which are thus produced are substantially homogeneous, and have an average particle size of from about 0.1 to 3 microns, preferably less than about 1 micron, an average solids content which can be easily adjusted between about 5 and 70 weight percent solids, preferably from about 40 to 70 weight percent solids and most preferably about 60 weight percent solids, and can be neutralized to a pH of from 3 to 12, preferably from 5 to 12, depending upon the particular emulsifier which is utilized. Such latices, when cast, form clear, smooth films which have excellent physical properties, including an improved modulus, improved tensile strengths, and superior elongation properties. These latices are highly useful as binders or coatings for paper, adhesives, particularly as adhesives for non-woven fabrics, prepared from such polymers as polyolefins, including polypropylene, polyethylene, etc.
DETAILED DESCRIPTION
The precursor polymer from which the improved latex compositions of the present invention are prepared preferably comprise a conjugated diene butyl rubber, which itself may be prepared by the dehydrohalogenation of halogenated butyl rubber. Specifically, these processes for preparing conjugated diene butyl rubber comprise contacting a solution of halogenated butyl rubber with: (1) a soluble metal carboxylate, where the metal is selected from the metals of Group IB, IIB, IIA and VIII of the Periodic Table; (2) a soluble carboxylic acid; and (3) an oxide or a hydroxide of a metal selected from Groups IA or IIA or the Periodic Table. Alternatively, the carboxylic acid and the Group IA or IIA metal oxide or hydroxide can be replaced in part by a Group IA or IIA metal carboxylate. Further details of the process for preparing the conjugated diene-containing butyl rubber used in preparing the latex of the present invention may as has been stated be gleaned from Ser. No. 228,728, filed Feb. 23, 1972, incorporated herein by reference.
In the initial step for preparing the present ionomeric latices from such polymers as conjugated diene butyl rubber, a Diels-Alder adduct of the conjugated diene butyl and a particular dienophile is formed. The Diels-Alder reaction for the addition of an ethylenic double bond to a conjugated diene such as 1,3-butadiene or cyclopentadiene, is a well known reaction. The use of various dienophiles in these reactions are also well known, including polyfunctional and monofunctional dienophiles. Typical of such polyfunctional dienophiles are m-phenylene-bis-maleimide, ethylene glycol dimethacrylate, trimethylolpropane trimethacrylate, and typical of such monofunctional dienophiles are cis-2-butenediol, maleic anhydride, maleic and fumaric acid, vinyl trichlorosilane, allyl alcohol, acrylic and methacrylic acid, crotonaldehyde and the like.
In the present process, an adduct is formed between the conjugated diene butyl rubber and an equimolar amount of a dienophile which is capable of implanting carboxylic acid functionality on the polymer, such as a dienophile anhydride, preferably maleic anhydride. Such an adduct is soluble in appropriate hydrocarbon solvents due to the absence of ionic links. No selective polar cosolvent, such as alcohol, is thus required to solubilize the polymer, as is the case with ionomers containing sulfonic acid functionality.
A cement phase is thus prepared from the resultant adduct by dissolving same in a hydrocarbon phase, such as hexane, heptane, benzene and various other such solvents which dissolve butyl, but preferably toluene. Alternately, the adduct can be formed by preparing a cement of the conjugated diene butyl and adding the dienophile thereto, the Diels-Alder reaction adduct being formed spontaneously. The rate of reaction may be accelerated by heating the cement. The concentration of polymer in the cement phase can vary from about 2 to 50 weight percent solids. This cement phase may now be used to prepare an aqueous emulsion of the adduct.
Subsequently, a raw emulsion is formed from the adduct of the conjugated diene butyl rubber. As stated previously, the emulsion is easily formed and is highly stable due to the solubility of the adduct in the hydrocarbon, and the insensitivity of the adduct to possible polar impurities. To form a stable raw emulsion from modified conjugated diene butyl, the cement phase of the polymer is contacted with water containing a suitable dispersing agent. The amount of H 2 0 employed can vary from about 50 to 200 volume percent of the cement phase, preferably from about 70 to 100 volume percent. The emulsifier used, as the dispersing aid, can be anionic or nonionic. An example of a typical anionic emulsifier useful in the present invention is Alipal CO-433, the sodium salt of a sulfate ester of nonylphenoxypoly(ethyleneoxy) 4 ethanol. An example of a typical chemically sensitive type of anionic emulsifier useful in the present invention is Neofat 92-04, a mixture of C 12 -C 18 fatty acids, the main component of which is 77% oleic acid. An example of a typical nonionic emulsifier useful in the present invention is Triton X100, an ethoxylated octyl phenol comprising about nine moles of ethylene oxide. The amount of emulsifier employed can vary from about 3 to 20 (based on the weight of polymer present), more preferably from about 3 to 10 parts per hundred.
Principally, the purpose of these additives or emulsifiers is to assist in the preparation of a stable raw emulsion, which can be formed because of the above-noted nature of the adducts of this invention. These homogeneous raw emulsions are thus characterized by an average particle size of between about 2 and 10 microns, and preferably less than about 5 microns.
Finally, it is now possible to prepare a stable, homogeneous artificial latex of the ionomeric form of the polymer. This is accomplished by neutralizing the raw emulsion with an appropriate base, either inorganic or organic in nature. Examples of an inorganic base will be ammonium hydroxide an alkali metal hydroxide, and most preferably potassium hydroxide. An example of an appropriate organic base would be ethyl amine. The result of this neutralization is the preparation of a substantially homogeneous raw emulsion in ionomeric form. This ionomeric raw emulsion is then stripped of solvent and excess water to form a finished latex. The finished latex is characterized by an average particle size of from about 0.1 to 3 microns, preferably from about 0.1 to 2 microns, and most preferably less than about 1 micron, an average solids content which can easily be adjusted between about 5 and 70 weight percent solids, preferably from about 40 to 70 weight percent solids, and most preferably to about 60 weight percent solids, without disturbing the homogeneity of the emulsion, and a pH of from about 5 to 12.
The preparation, in such a relatively simple manner, of such a homogeneous, stable latex of the ionomeric polymer from these polymers was totally unexpected. Furthermore, the latex itself has been found to possess certain unexpectedly superior properties as compared to previously prepared latices. The latices of this invention are therefore easily cast into smooth, clear films, which demonstrated improved tensile strength of two orders of magnitude greater than butyl rubber when similarly cast from latex, i.e. 3000 psi vs 30 psi. They have an improved 500% modulus of greater than about 500 psi, and exhibit superior properties as a binder for paper and as an adhesive, particularly for non-woven fabrics, as polyolefins, including polypropylene, polyethylene, etc. These properties are believed to principally result from the stable, homogeneous nature of the latices of the ionomeric polymers containing carboxylate functionality produced by the present process.
A more complete understanding of the present invention can be obtained by reference to the following examples:
EXAMPLE 1
A cement was prepared by dissolving 275 grams of conjugated diene butyl rubber (prepared by the process of Ser. No. 228,728, and containing 1.2 mole percent conjugated diene, 0.14 mole percent allyl ester and 0.14 weight percent chlorine) in 1,750 milliliters of toluene in a 2-gallon can, on a reciprocating shaker. When all of the polymer had dissolved, 6.5 grams of maleic anhydride were added and the mixture left on the shaker for 4 days to effect solution of the anhydride and partial reaction with the polymer. The can was then removed, and placed on a steam bath where the contents were nitrogen blanketed, and allowed to react completly by heating overnight (approximately 16 hours). The cement thus prepared was used in the following manners shown in Examples 2 and 3.
EXAMPLE 2
Anionic Emulsion with Non-Ionic Character
Three hundred and thirty-three grams of the cement, namely the conjugated diene butyl rubber adduct dissolved in toluene, containing 50 grams of the polymer, was added to a water phase containing 300 grams of deionized water and 15.5 grams of 31% Alipal, an anionic surfactant, and hand stirred. An emulsion was formed, and the particle size of this crude emulsion was reduced in dispersator for three 3-minute intervals, at 40 volts open, 110 volts open and 110 volts closed. The average particle size of the raw emulsion was then approximately 1 micron. Neutralization of the raw latex was then carried out by adding 1.3 grams of potassium hydroxide (0.024 moles) to a pH of 11.7. The raw latex was then stripped on a Rotovac to remove the toluene and excess water. The finished latex included 47.8 by weight percent solids and was very fluid.
A smooth, clear film formed by casting from the latex followed by drying revealed the following physical properties:
100% modulus, psi = 150
300% modulus, psi = 375
500% modulus, psi = 525
tensile strength, psi = 2800
% elongation = 1000
EXAMPLE 3
Anionic Emulsion
To another 333 g. portion of the cement prepared in Example 1 containing 50 grams of the polymer were added 2.5 grams of Neofat 92-04, an emulsifier. This cement phase was slowly added to a water phase containing 300 grams of deionized water and 5.0 grams of 10 weight percent potassium hydroxide solution, and hand mixed. A homogeneous mixture did not form, and the particle size was reduced on a dispersator for three 3-minute intervals, at 40 volts open, 110 volts open and 110 volts closed, respectively. The solution still did not appear homogeneous, and 13 milliliters of a 10 weight percent solution of potassium hydroxide was then added, followed by reduction of the particle size on the dispersator for 3 minutes at 110 volts closed. The particle size of the raw emulsion was then approximately 1 micron average, and had a pH of 11.9. The raw latex was then stripped on a Rotovac to remove toluene and excess water and the finished latex had 47 weight percent solids and was very fluid.
A sample was then again cast on a glass plate and dried as in Example 2, and demonstrated the following physical properties:
100% modulus, psi = 200
tensile strength = 310
% elongation = 200
EXAMPLE 4
In order to demonstrate that a chemically sensitive form of an ionomeric latex (in coagulable form) has been prepared in Example 2, samples of the latex of the present invention and latex prepared from unmodified butyl rubber and a chemically sensitive emulsifier were compared. Each was coagulated with a 10% solution of calcium nitrate, with the following results in terms of milliliters of Ca(NO 3 ) 2 per 20 grams of polymer to effect coagulation:
______________________________________Latex Prepared From Latex PreparedConjugated Diene Butyl From Butyl______________________________________8.8 8.0______________________________________
These data show that both latices are readily coagulable by the addition of small amounts of polyvalent, water-soluble metal salts. | A process for preparing latices in ionomeric form from copolymers of an isoolefin containing from 4 to 7 carbon atoms and a conjugated multiolefin containing from 4 to 14 carbon atoms, where a major portion of said conjugated multiolefin has conjugated diene unsaturation, is disclosed. The process principally comprises forming an adduct of conjugated diene butyl rubber with a dienophile capable of implanting carboxylic acid functionality on the polymer such as maleic anhydride, emulsifying the adduct thus formed, and neutralizing the resulting emulsion with a suitable base. Highly improved ionomeric latices are also disclosed, having an average particle size of less than about 1 micron, average solids contents easily adjusted from between about 5 to 70 weight percent solids, and having a pH, depending on the emulsifier used, of from 3 to 12. Films cast from these latices have an improved tensile at break of greater than about 2500 psi. | 2 |
FIELD OF THE INVENTION
[0001] The present invention relates generally to process industry, such as power plants. Particularly the present invention relates to determining fouling in a heat exchange system and method of cleaning such a heat exchange system, such as a boiler of a power plant. More particularly, the present invention relates to a method for air/fuel control. Furthermore the present invention relates to a method for optimizing of cleaning particles or fouling from surfaces of a process system.
BACKGROUND OF THE INVENTION
[0002] It has been known for a long time that maintaining the stoichiometric ratio between air and fuel in a pulverized fuel fired process is an important criterion to minimize emissions such as NO x and CO. For example, a pulverized coal (PC) boiler constitutes a large number of burners. It has been both observed and proved that the stoichiometric ratio between air and fuel has to be maintained on a per burner basis. Therefore, both the fuel flow and the airflow are measured, and either the airflow or the fuel flow is used as the control variable, to keep the ratio between the fuel flow and the airflow for each individual burner within strict limits.
[0003] It has been proved that matching the airflow to the fuel flow for each individual burner reduces emissions as well as improves other variables in the operation of a solid fuel fired boiler. However, it has been identified that only matching the airflow and the fuel flow does not provide the minimum emission level for the NO x , CO and other adjacent emissions.
[0004] The typical and current air/fuel balancing concept has been described in the scheme of FIG. 1 . As illustrated in FIG. 1 , typical air/fuel balancing method is based on air flow and coal flow measurements for each individual burner. Please note, that the total amount of air is matched with the total amount of fuel by keeping the O 2 concentration in the exhaust gas on a certain level (e.g. 2%). The point of the known optimization methods is to keep the same share of fuel and air on each burner. If one burner carries a higher amount of fuel, a higher amount of air should be distributed to that burner. That is, the percent fuel and the percent air on one burner should be the same. However, now it has been surprisingly observed that occasionally either more or less air than the stoichiometric ratio would suggest, is needed for a certain burner in order to minimize the emissions. The reason for this phenomenon is unknown, but has most likely a connection to the mixing properties of the fuel and air in the flame. Therefore, a need exists in the industry for a method of optimizing air/fuel ratio wherein optimization will be made more efficiently being based on the measurements of the actual process conditions.
[0005] The present invention relates further to soot cleaning optimization. Minimizing of emissions such as NOx, decreases also the need for soothing. Cleaning particles (fouling) from surfaces is a routine that is fairly common in the process industry. For example, when running a combustion process it is essential to keep heat exchanger surfaces clean for the sake of efficiency. Many different kinds of soot cleaners (blowers) are used and they are run according to a certain sequence to keep the heat exchange surfaces as clean as possible. The soot cleaning is generally done by blowing steam on the heat transfer surfaces or by using pressurized air or sound waves to remove the particle layer, mainly soot from the heat transfer surfaces. The particles released from the heat transfer surface section that is soot blown are then entrained into the exhaust gas stream.
[0006] Running soot cleaners is expensive. Furthermore, cleaning heat exchanger tubes with steam, without any particle layer on their surfaces, is very eroding for the walls of these tubes. Erosion of the heat exchanger tubes is again a very expensive affair. However, high expenses will emerge as well if soot cleaners are not used at all. Therefore, it is of great importance to optimize the soot cleaning process thoroughly.
[0007] Typically the need for the soot cleaning is estimated from raised exhaust gas temperatures and possible steam temperature anomalies. Some systems weight the heat transfer tubes and on the basis of the mass of the tubes estimate the amount of the fouling on the tubes. Information obtained by these methods does not necessarily give the precise information about which heat exchanger tubes has the most part of the soot stuck to its surface and which tubes are fairly clean.
[0008] Therefore, a need exists in the industry for a method of optimizing soot cleaning whereby the soot cleaning will be made more economically and efficiently being based on the measurements of the actual process conditions.
OBJECTS AND SUMMARY OF THE INVENTION
[0009] It is an object of the invention is to provide a method for air/fuel control wherein at least one of the group of primary airflow, mill parameters, and secondary airflow is controlled using a control algorithm, which is determined by correlation analysis between ECT signals and the output and input signals of the process in order to detect dependencies, and by fuzzy modeling of the dependencies.
[0010] Furthermore, an another object of the invention is to provide a soot cleaning optimization method to be used in a process industry in which information on a sequence of a cleaning, time between running, etc. variables for cleaning devices are optimized based on the measurement of the particles entrained in the gas stream of the process. The measurement is based on detecting static electricity and/or change thereof in the gas stream of the process.
[0011] Another object of the invention is to provide means for obtaining accurate knowledge of location and amount of fouling inside a heat exchange system, such as a boiler of a power plant. According to the invention this knowledge can be used to optimize cleaning of a heat exchange system.
[0012] A typical method in a heat exchange system according to the invention comprises following steps:
Exhaust gas steam is led by a heat exchange surface of the heat exchange system. A certain part of the heat exchange surface of the heat exchange system is cleaned with a cleaning equipment having an operation parameter status. A typical cleaning equipment of the invention, e.g. a steam based soot blower in a boiler, is arranged to clean a certain part of the heat exchange tubes in the boiler. A typical large boiler comprises several separate pieces of cleaning equipment, each of which can typically be run separately of each other. A typical steam based soot blower in a boiler blows steam of a certain pressure on the heat exchange tubes to be cleaned and is moved over its part of the tubes at a certain point of time, with a certain speed. These operation parameters can normally adjusted by the operator of the boiler. Particles are released from the heat exchange surface. Normally and mostly these particles are soot. Soot is formed on different parts of the heat exchange surfaces with different speeds depending on various process parameters, e.g. the type and amount of fuel used. The amount of particles released from a certain part of the heat exchange surfaces by the cleaning equipment depends e.g. on the steam pressure of the cleaning equipment and the amount of particles that has been formed on that certain part being cleaned. The time elapsed between two cleanings of the same heat exchange tubes naturally effects on the amount of impurities formed on the tubes. The released particles are led into the exhaust gas stream of the heat exchange system. Amount and/or type of the released particles in the exhaust gas stream is measured and particle measurement data of these particles is created on the basis of these measurements. These measurements can be done with different kinds of equipment. Examples of a measurement systems and methods suitable for this purpose are given in the applicant's earlier patent publications U.S. Pat. No. 6,031,378 and WO 02/06775. That system is called Electric Charge Transfer System, or ECT-system. Suitable parts of these publications are hereby incorporated in this text by reference. In one embodiment of the invention the mass flow of particles in the exhaust gas stream is measured. Information of the fouling is created in an electronic memory by linking together and storing in the electronic memory coordinates of the part of the heat exchange surface of the heat exchange system being cleaned and the measurement data created during the cleaning of said part.
[0019] A typical system for determining fouling in a heat exchange system according to the invention comprises means that enable the method of the invention, i.e.:
Means for detecting operation parameter status of a cleaning equipment arranged to clean a certain part of the heat exchange surface of the heat exchange system. Naturally, these means should provide the system with the status of the wanted operation parameters in electronic form. Means for measuring the amount and/or type of released particles in the exhaust gas stream of the heat exchange system, e.g. the above-mentioned Electric Charge Transfer System, or ECT-system. Means for creating particle measurement data of released particles in the exhaust gas stream. This is normally a runnable computer program on e.g. the memory of a PC or any other suitable computer. An electronic memory e.g. on the PC. Means for creating information of the fouling in the electronic memory by linking together and storing in the electronic memory coordinates of the part of the heat exchange surface of the heat exchange system being cleaned and the measurement data created during the cleaning of said part. This means that a database is created e.g. on the hard disc of the PC. This databae can then be used in many different ways to examine the fouling.
[0025] The system of the invention can comprise e.g.:
Electronic means for analyzing the information of the fouling and for creating control signal for the cleaning equipment of the heat exchange system. This means e.g. a computer program used to analyze the information of the fouling in the electronic memory and signaling means from said computer to the cleaning equipment.
[0027] The operation parameter status of the cleaning equipment that is detected and stored in the electronic memory typically comprises status of at least one and preferably several of the following operation parameters:
Identification data of the cleaning equipment. The piece of cleaning equipment used at any time should be clearly identifiable. Coordinates of the cleaning equipment in the heat exchange system. Operational status of the cleaning equipment, i.e. is the cleaning equipment running or not running, Speed of the cleaning equipment. Information on the effect of the cleaning equipment, e.g. steam pressure used.
[0033] The most important piece of information to know is from which part of the heat exchange surfaces the particles measured in the exhaust gas stream were released. Knowledge about fouling tendency, i.e. the amount of fouling formed on different parts of the heat exchange system is obtained with this information. Typical suitable soot blower equipment comprises at least one of the following types of devices:
[0034] steam based soot blower
[0035] acoustic soot blower
[0036] air gun.
[0037] Other possible cleaning equipment suitable for use in the method and system of the invention are:
[0038] hammer cleaner
[0039] mechanical cleaner, such as steel-wire brush.
[0040] These different kinds of cleaning equipment are suitable for different circumstances.
[0041] In an embodiment of the method according to the invention the information of the fouling stored in the electronic memory is processed as a function of the heat exchange surface coordinates. Typically his process comprises optimization steps in order to find at least one of the following optimal parameters:
an optimal time to start cleaning of a particular part of the heat exchange surface of the heat exchange system optimal cleaning speed for a cleaning equipment of a particular part of the heat exchange surface of the heat exchange system optimal operation parameters for the cleaning equipment for cleaning a particular part of the heat exchange surface of the heat exchange system.
[0045] In an embodiment of the invention the aforementioned optimization is based on one or more of the variables:
time to be elapsed between two cleanings of a particular part of the heat exchange surface of the heat exchange system fouling tendency of ash on a particular part of the heat exchange surface carbon content in ash.
[0049] As a result of this kind of optimizations more efficient cleaning of the heat exchange system is achieved.
[0050] In further embodiments of the invention the information of the fouling stored in the electronic memory is used for at least one of the following:
Estimating fouling tendency on the heat exchange surfaces as a function of heat exchange surface coordinates. This means information about how easily fouling is formed on a certain location on the heat exchange surfaces. Estimating fouling distribution on the heat exchange surfaces as a function of heat exchange surface coordinates. This means information about how much fouling is there on a certain location on the heat exchange surfaces.
[0053] As a result of this kind of estimations cleaning of the heat exchange system can be planned to be more efficient.
[0054] In an embodiment of the invention
particle distribution on a cross-section of the exhaust gas channel is measured the measured data of the particle distribution is compared on previous measurements of the particle distribution fouling tendency and location for the fouling in the heat exchange system is determined by utilizing the comparison.
[0058] The particle distribution on a cross-section of the exhaust gas channel gives knowledge, when compared with previous results, about the origin of the particles. The afore-mentioned Electric Charge Transfer measurement system is very suitable for these particle distribution measurements. With help of the ECT system fouling tendency and location for the fouling in the heat exchange system are determined in an accurate manner. Also the amount of unburned carbon in the ash flow in the exhaust gas stream can be estimated using signals produced by the ECT measurement system.
BRIEF DESCRIPTION OF THE DRAWINGS
[0059] The present invention is illustrated by way of an example and is not limited in the accompanying figures, in which alike references indicate similar elements, and in which;
[0060] FIG. 1 illustrates schematically an air/fuel balancing concept according to the prior art,
[0061] FIG. 2 illustrates schematically a flow scheme of correlation analysis according to the present invention,
[0062] FIG. 3 illustrates schematically a fuzzy modeling algorithm according to the present invention,
[0063] FIG. 4 illustrates schematically an implementation of a control system according to the present invention,
[0064] FIG. 5 illustrates a schematic embodiment of an arrangement according to the present invention,
[0065] FIG. 6 illustrates a block scheme of an optimization according to the present invention, and
[0066] FIG. 7 illustrates a simplified block scheme of a soot cleaning method according to the present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0067] Generally, the first aspect of the invention provides a method for air/fuel control in burners, such as pulverized coal boiler, based on a measurement of a flow of particles for a suspension of gas and solids. The measurement can be used e.g. by using the measurement system disclosed in the applicant's earlier patent publication U.S. Pat. No. 6,031,378 and/or the method disclosed in the applicant's earlier patent publication WO 02/06775. The measurement system (Electric Charge Transfer System, ECT-system), disclosed in the above-mentioned patent publications, is able to measure e.g. the velocity and the mass flow of particles for a suspension of gas and solids. The ECT measurement is of a local character, that is, the signal caused by the flowing particles is a function of distance from the particles to the ECT antenna. Therefore, a big duct normally requires use of many ECT antennas. It should be noticed that the particles entrained in the gas flow are not necessarily evenly distributed over the whole duct. Using several antennas will ensure that the particle flow is sensed properly over the whole duct, even though the rope of the particles would change its coordinates. Please note that a not even distribution of ash particles in the exhaust duct contains also a lot of valuable information.
[0068] The ECT system measures the state of the two-phase flow in burner ducts. The ECT measurement splits the raw signal (ECT LF signal) into AC and DC components. DC component is the spectral line for ˜0 Hz (mean value). Normal AC is the standard deviation of the raw signal on the frequency band 0.3-15 Hz. The ECT velocity measurement collects measurement signals with a high sampling frequency (22 kHz). Fans and compressors as well as the combustion process (flame) cause pressure gradients in the gas flow. These gradients can be seen as intensified spectral density on different frequencies on the raw signal (ECT HF signal).
[0069] It has been observed that some patterns in the above mentioned ECT signals correlate with the readings from the emission metering devices of the boiler. The ECT measurement will provide information whether more or less air is needed than the stoichiometric ratio between fuel and air would suggest. The methodology to determine the optimal dosing of air for a burner is explained in more detail below.
[0070] The ECT signals (HF and LF) mirror the flow properties in the burner ducts. These flow properties depend on the process variables such as particle size, mass flow, particle velocity, and the flame properties (flame properties affect mainly the ECT HF signals). Dependency between the ECT signals and the output signals (NOx, CO, O2, airflow measurements, etc.) is estimated with different methods. The following methods can be used: correlation analysis, spectral analysis and fuzzy modeling. The result will be a dependency matrix showing which burner(s) has the strongest connection to the emission rates (e.g. NOx and CO).
[0071] The correlation analysis will typically build up large correlation matrixes between the ECT variables for the different burners as well as between the ECT variables of burners and the output variables (NOx, CO, O2, etc.). The size of the matrixes can be reduced significantly by eliminating such ECT signals that have strong correlation to a chosen ECT signal. In order to reduce the size of the matrix, a loop between 1 and n (number of burner pipes) is established where j expresses the reference burner pipe and k is the burner pipe against which the correlation is checked. If the correlation is strong enough between the ECT signals of the pipe j and the pipe k, the pipe k can be eliminated from the matrix due to the fact that the ECT signals for the pipe k is represented in the ECT signals in the pipe j because of the strong correlation. This method will reduce the size of the matrixes and would also make it possible to group different burner pipes according to their internal correlation. Please see the flow scheme illustrated in FIG. 2 (R shows the correlation).
[0072] Spectral analysis is applicable only on signals that have a well-defined sampling rate. This is not the case for many of the output measurements used in prior art methods, which are based on the principle of taking a sample and analyzing it offline. Also time of update for these measurements can be even a few minutes.
[0073] The most potential signal for spectral analysis purposes is the ECT HF signal for each pipe because this signal type reflects well the state of the flame. Please note that two individual channels are used for each pipe to get the particle velocity. The flame impacts the ECT HF signals strongly besides the fans that transport the gas into the boiler as well as out from the boiler.
[0074] The spectral analysis will divide the ECT HF signals into different bands and determine which of the bands are correlating with the flame quality, and which of the bands are also related to other variables such as particle size, mass flow of the coal etc. The standard deviation will be calculated for each band and stored as a variable in a matrix.
[0075] When the ECT-system is used, there are a lot of signals available with different properties. The key issue is to be able to determine the dependency between these signals in a reliable and simple way. Fuzzy logic rules fulfill these criteria. The noise has to be removed from the signal without loosing any relevant information in the signal. The algorithm works roughly as illustrated in FIG. 3 for each measurement vector.
[0076] The air/fuel control method according to the present invention can favorably be added on top of the air to fuel balancing in order to gain more reduction in the emissions. The control variables that can be used are fairly limited. The main control variables to affect the process are as follows: primary airflow (PA), mill parameters (separator settings, etc.) and secondary airflow (SA).
[0077] Please note that the role of the primary airflow is to transport the coal to the furnace, and the primary air should usually be kept as low as possible.
[0078] Therefore, this variable does not usually offer much controllability, but the primary air should be high enough to provide a proper transport of the coal.
[0079] Mill parameters such as separator settings etc. are important in order to keep the particle size of the coal as small as possible and the flow as steady as possible. However, there are only static classifiers (separators) on many plants, which limits the use of the separator settings as a control variable. It should be noticed that the steady flow of the fuel and a small particle size are essential for an optimal combustion.
[0080] The most favorable variable to be used for minimizing the emissions is usually the secondary air (SA). The SA has a great impact on the flame, and hence, also impacts the ECT HF signals strongly. The block scheme as illustrated in FIG. 4 shows the control structure roughly.
[0081] Generally, the second aspect of the present invention provides an optimized soot cleaning process based on a measurement of a mass flow of particles for a suspension of gas and solids. One process of this kind is illustrated as a simplified block scheme in FIG. 7 . The measurement can be used e.g. by using the measurement system disclosed in the applicant's earlier patent publication U.S. Pat. No. 6,031,378 and/or the method disclosed in the applicant's earlier patent publication WO 02/06775. Other suitable measuring systems are for e.g. other electrical measuring systems and optical analyzing systems. The soot cleaning optimization method can be utilized also independently in processes in which method for air/fuel control according to the first aspect of the invention is not used.
[0082] When the soot cleaning (particle cleaning) is in operation there will be more particles entrained in the gas stream than normally. The increase in the concentration of the particles will be calculated based on the increase in the ECT reading during the soot cleaning. Please see the illustration in FIG. 5 describing the arrangement. It should be noted, that the soot cleaning method according to the present invention can be carried out by using also other suitable measuring systems than ECT and which can detect changes in the gas stream during the soot cleaning. Such systems include e.g. optical measuring systems and other electrical measuring systems, such as systems using laser or acoustic waves.
[0083] The dependency between each cleaner and the ECT reading is mapped. This means in practice that the amount of particles that has built up in the coverage of a cleaning device k is calculated from the ECT readings.
m k =f ( ECT )/ T k 1
where:
[0084] m k =particle mass flow when cleaner k is running
[0085] T k =time elapsed between the last run of cleaning unit k
[0086] It should be noticed that the signals from advantageously all ECT antennas will be used for calculating the mass of particles that are emerged into the gas stream by cleaning unit k. In a situation where several cleaners are running simultaneously, a multivariable correlation analysis is to be applied.
[0087] The main variable that is to be optimized is the time (T k ) between the run of each cleaning device k (k=1, n, where n is the number of cleaning devices). This procedure is fairly straightforward. A limit (M LK ) for how big the m k is to be for cleaning is defined. The T k is then extrapolated from the latest run of the cleaning unit k, by also noting other process variables such as gas flows, solid feeds, etc.
[0088] Besides the elapsed time between the run of the cleaning unit, also the runtime and other parameters concerning the cleaning device is to be determined in order to achieve a maximal cleaning efficiency. The object function for each cleaning device depends on the physical properties of the device and should, hence, be determined on a case by case basis.
[0089] Furthermore, it has been observed that a certain signal behavior reflects specific conditions for the particles passing the antenna matrix. For example a positive DC signal on a normal AC level indicates a higher content of carbon in the ash flowing past the ECT antenna matrix. If the particles show a high negative DC signal on a normal AC level, the particles possesses properties that enable them to easily to stick onto the surfaces. Hence, ECT signal can be used to estimate important properties for the ash flowing in the exhaust gas channel. Please note that a high carbon in ash indicates a poor combustion and hence a risk for fouling.
[0090] The concept according to the present invention is used to optimize the soot cleaning more thoroughly. The block scheme in FIG. 6 illustrates the procedure. At least partly based on ECT measurements, one can estimate one or more of the following variables: 1) a time to be elapsed between runs of cleaning units k, 2) fouling tendency of the ash, and 3) carbon content in ash. Beside said estimates, one can use one or more of the following attributes as a variable in optimization: a) data input (temperatures, steam date, etc.) from data collection system of the process, b) data base containing history from previous cleaning and results, and c) ECT measurements. According to the present invention, by combining desired values from the group of estimated variables 1-3 and variables a-c, optimization of the soot cleaning process can be made. An aim of the optimization process is to maximize the efficiency of the process, such as the combustion process, and to minimize the costs of the cleaning process. As a result from the optimization process, one achieves information which can be used to control the cleaning sequence, time between running of cleaning devices, or the like variables for the cleaning devices.
[0091] The present invention provides an improved control for the soot cleaning process. Based on the information achieved with the optimization according to the present invention, one can e.g. define individually for each separate cleaning device different time between running and running parameters during cleaning.
[0092] While the invention has been described in the context of a preferred embodiment, it will be apparent to those skilled in the art that the present invention may be modified in numerous ways and may assume many embodiments other than that specifically set out and described above. The air/fuel optimization method and the soot cleaning optimization method can be exploited independently and thus described methods are not dependent of each other. Furthermore, it should be noted, that the soot cleaning method according to the present invention can be carried out by using also other suitable measuring systems than ECT and which can detect changes in the gas stream during the soot cleaning. Such systems include e.g. optical measuring systems and other electrical measuring systems. | Means for obtaining accurate knowledge of location and amount of fouling inside a heat exchange system, such as a boiler of a power plant, are provided. According to the invention this knowledge can be used to optimize cleaning of a heat exchange system. The system of the invention comprises: Means for measuring particles in the exhaust gas stream of the heat exchange system. These particles are at least partly released when cleaning a certain part of the heat exchange surface of the heat exchange system. Means for creating information of the fouling in an electronic memory by linking together coordinates of the part of the heat exchange surface being cleaned and the measurement data created during the cleaning of said part. | 5 |
CROSS REFERENCE TO RELATED APPLICATION
This application claims the benefit of U.S. Provisional Patent Application Ser. No. 60/168,147 filed Nov. 29 1999.
FIELD OF THE INVENTION
The present invention relates to perpendicular magnetic recording media, and more particularly relates to media designed to suppress soft magnetic underlayer noise.
BACKGROUND INFORMATION
Perpendicular magnetic recording systems have been developed for use in computer hard disk drives. Some examples of perpendicular magnetic recording heads for use in such systems are described in U.S. Pat. No. 4,438,471 to Oshiki et al., U.S. Pat. No. 4,541,026 to Bonin et al., U.S. Pat. No. 4,546,398 to Toda et al., U.S. Pat. No. 4,575,777 to Hosokawa, U.S. Pat. No. 4,613,918 to Kania et al., U.S. Pat. No. 4,649,449 to Sawada et al, U.S. Pat. No. 4,731,157 to Lazzari, and U.S. Pat. No. 4,974,110 to Kanamine et al.
Some examples of perpendicular magnetic recording media are described in U.S. Pat. No. 4,410,603 to Yamamori et al., U.S. Pat. No. 4,629,660 to Sagoi et al., U.S. Pat. No. 5,738,927 to Nakamura et al., and U.S. Pat. No. 5,942,342 to Hikosaka et al.
One of the challenges to implement perpendicular recording is to resolve the problem of soft underlayer noise. The noise is caused by fringing fields generated by magnetic domains in the soft underlayer that can be sensed by the reader. For the write process to be efficient, high moment materials, e.g., B S >20 kG, may be used for the soft underlayer. If the domain distribution of such materials is not carefully controlled, very large fringing fields can introduce substantial amounts of noise in the read element. Not only can the reader sense the steady-state distribution of magnetization in the soft underlayer, but it can also affect the distribution of magnetization in the soft underlayer, thus generating time-dependent noise. Both types of noise should be minimized.
The present invention has been developed in view of the foregoing, and to address other deficiencies of the prior art.
SUMMARY OF THE INVENTION
The present invention provides perpendicular recording media having a soft magnetic underlayer and magnetic regions which generate an external magnetic field in the soft magnetic underlayer. The soft magnetic underlayer is brought into a substantially single-domain state by the magnetic field. Reducing or eliminating multiple domains addresses the noise problem noted above. In a preferred embodiment, the magnetization in such a single-domain state is aligned radially without local domain walls. It is noted that a “single-domain” state is an approximation, which applies to materials without any magnetic defects. In actual magnetic films, the film will be magnetically saturated in accordance with the present invention in order to sufficiently reduce the number of domain walls, thus suppressing soft underlayer noise.
An aspect of the present invention is to provide a perpendicular magnetic recording medium including a soft magnetic underlayer and means for generating a magnetic field in the soft magnetic underlayer.
Another aspect of the present invention is to provide a perpendicular magnetic recording medium which includes a soft magnetic underlayer, a hard magnetic recording layer over the soft magnetic underlayer, and at least one magnetic region which generates a magnetic field in the soft magnetic underlayer.
A further aspect of the present invention is to provide a method of making a perpendicular magnetic recording medium. The method includes the steps of providing at least one magnetic region on a substrate disk, and providing a soft magnetic underlayer and a hard magnetic recording layer on the substrate disk in proximity to the at least one magnetic region. The magnetic region generates a magnetic field in the soft magnetic underlayer.
These and other aspects of the present invention will be more apparent from the following description.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a partially schematic side view of a perpendicular recording head and a perpendicular recording medium which may incorporate a reduced-noise soft magnetic underlayer in accordance with an embodiment of the present invention.
FIG. 2 is a partially schematic top view of a perpendicular recording medium illustrating a soft magnetic underlayer and hard magnetic regions which generate a radial magnetic field in the soft underlayer in accordance with an embodiment of the present invention.
FIG. 3 is a partially schematic radial section view of a perpendicular recording medium including hard magnetic regions which generate a radial magnetic field in the soft underlayer in accordance with an embodiment of the present invention.
DETAILED DESCRIPTION
FIG. 1 is a partially schematic side sectional view of a perpendicular magnetic recording medium 10 . The medium 10 includes a substrate 12 , which may be made of any suitable material such as ceramic glass, amorphous glass or NiP plated AlMg. A magnetically soft underlayer 14 is deposited on the substrate 12 . Suitable soft magnetic materials for the underlayer 14 include CoFe and alloys thereof, FeAlN, NiFe, CoZrNb and FeTaN, with CoFe and FeAlN being preferred soft materials. A magnetically hard recording layer 16 is deposited on the soft underlayer 14 . Suitable hard magnetic materials for the recording layer 16 include multilayers of Co/Pd or Co/Pt, L10 phases of CoPt, FePt, CoPd and FePd and hcp Co alloys, with such multilayers and L10 phases being preferred hard materials. A protective overcoat 18 such as diamond-like carbon may be applied over the recording layer 16 .
FIG. 1 also illustrates a perpendicular recording head 20 positioned above the magnetic recording medium 10 . The recording head 20 includes a main pole 22 and an opposing pole 24 . During recording operations, magnetic flux is directed from the main pole 22 perpendicularly through the recording layer 16 , then in the plane of the soft underlayer 14 back to the opposing pole 24 .
A partially schematic top view of the magnetic recording medium 10 is shown in FIG. 2 . The ring-shaped soft magnetic underlayer 14 is positioned between an inner magnetic ring-shaped band 26 and an outer magnetic ring-shaped band 28 . The inner and outer magnetic bands 26 and 28 may be made of any suitable magnetic material such as hcp Co alloys (e.g., CoPt 12 Cr 13 with M S ˜600 emu/cc and 4πM S ˜7.5 kG), L10 phases of FePt, CoPt, FePd or CoPd (e.g., with M S ˜1,200 emu/cc and 4πM S ˜15 kG), L10 alloys such as FePtB, and rare earth magnetic materials such as NdFeB (e.g., with 4πM S ˜14 kG) and SmCo (e.g., with 4πM S ˜12 kG), with such hcp Co alloys L10 phases being preferred materials. The size, shape and magnetic characteristics of the magnetic bands 26 and 28 may be selected as necessary in order to provide a sufficient magnetic field radially through the soft underlayer 14 . For example, the radial width of each magnetic band 26 and 28 may typically range from about 0.1 to about 100 mm, and the thickness of each magnetic band 26 and 28 may typically range from about 0.1 to about 50 microns. The radial width of the soft underlayer 14 typically ranges from about 5 to about 100 mm.
Although continuous concentric circular magnetic bands 26 and 28 are shown in FIG. 2, other geometries may be used as long as a sufficient magnetic field is generated in the soft underlayer 14 . For example, discontinuous ring-shaped bands may be used, e.g., the bands may have gaps around their circumferences. Furthermore, non-circular bands may be used, e.g., square, octagonal, etc. Alternatively, multiple discrete magnetic elements may be arranged in a desired pattern. Although two concentric bands 26 and 28 are shown in FIG. 2, any suitable number of bands may be used, e.g., one, two, three, four, etc. The magnetic bands 26 and 28 may be deposited on a disk substrate in the presence of radial magnetic field. Deposition in a radial magnetic field causes net remanent magnetization in the magnetic bands to be aligned radially, which, in turn, creates a radially distributed magnetic field in the plane of the disk substrate between the bands.
FIG. 3 is a partially schematic side sectional view of the magnetic recording medium 10 in accordance with an embodiment of the invention. Although a single-sided disk is shown in FIG. 3, double-sided media may alternatively be used. The soft underlayer 14 is located between the magnetic bands 26 and 28 . Preferably, the soft underlayer 14 and at least a portion of the magnetic bands are located in the same plane, as shown in FIG. 3 . The thicknesses of the soft underlayer 14 and the magnetic bands 26 and 28 may be different, as shown in FIG. 3, or their thicknesses may be the same.
As shown in FIG. 3 . The magnetic recording layer 16 is applied on, and is preferably coextensive with, the soft underlayer 14 . The protective coating 18 is applied over the recording layer 16 and the magnetic bands 26 and 28 .
The soft underlayer 14 preferably has radial anisotropy with the easy axis aligned along the radius of the disk and a coercivity smaller than the minimum radial field induced by the magnetic bands 26 and 28 . The magnetic bands 26 and 28 typically generate fields in excess of 10 Oe, more preferably in excess of 50 or 60 Oe.
To make a soft underlayer with built-in radial anisotropy several approaches can be used. Deposition in an external radial magnetic field (field induced anisotropy) may be used. Magnetostriction may be used if the soft underlayer film is deposited on an appropriate underlayer that would induce radially aligned stress in the soft underlayer film. Post-deposition annealing of the soft underlayer in radially aligned magnetic field may also be used.
If the coercivity of the soft underlayer material 14 is smaller than the fields generated by the concentric magnetic bands 26 and 28 , the entire soft underlayer 14 will be saturated radially in the direction of the applied field. Radially aligned magnetization also improves dynamic properties of the soft underlayer and reduces Barkhausen noise since the magnetization switching during the write process inside the soft underlayer will follow magnetization rotation rather than domain wall motion, which is known to be a faster and less noisy process.
The present recording media may be manufactured using conventional media tools. All of the structures of the disk are of macroscopic sizes and do not require complicated lithography as, for example, patterned servo technologies or patterned media. Deposition of the magnetic features on a disk substrate can be done directly utilizing shadow masks placed in proximity of the substrate. For example, the magnetic bands 26 and 28 may first be deposited using a shadow mask. Next, another shadow mask may be used to deposit the soft underlayer 14 and the recording layer 16 . After the second shadow mask is removed, the protective overcoat 18 may be deposited over the recording layer 16 and magnetic bands 26 and 28 .
Both boundary element modeling and analytical calculations show that fields with the magnitudes of about 6 to 60 Oe or higher can be achieved in accordance with the present invention, for example, with band separation of 2 cm, hard magnetic material thicknesses of 1-10 μm, and 4πM S of about 14 kG for NdFeB (4πM S ˜12 kG for SmCo). If stronger fields are necessary, thicker bands can be deposited. For example, if an hcp Co alloy is used, e.g., CoPtCr with M S ˜600 emu/cc, 4πM S ˜7.5 kG, the thickness of the bands may be increased (almost doubled in the case of CoPt 12 Cr 13 alloy) in order to achieve fields comparable to the fields generated with NdFeB or SmCo.
The magnetic field from a single band may be expressed as: H ∼ 4 π M S · δ [ 1 r - 1 r + w ] ,
where δ is the thickness of the magnetic band, w is the radial width of the band, and r is the radial distance away from the edge of the band. For a band made of NdFeB with 4πM S ˜14 kG, thickness α of 10 μm, r=1 cm, and w=0.3 cm, the field H is equal to about 32 Oe. Provided that there is a second magnetic band, e.g., as shown in FIG. 2, the magnitude of the achievable field doubles to approximately 64 Oe.
Whereas particular embodiments of this invention have been described above for purposes of illustration, it will be evident to those skilled in the art that numerous variations of the details of the present invention may be made without departing from the invention as defined in the appended claims. | The present invention provides perpendicular recording media having a soft magnetic underlayer and magnetic regions which generate an external magnetic field in the soft magnetic underlayer. The soft magnetic underlayer is brought into a substantially single-domain state by the magnetic field, thereby reducing or eliminating unwanted noise in the soft underlayer. In a preferred embodiment, the recording medium includes a ring-shaped soft magnetic underlayer positioned between concentric ring-shaped magnetic regions. | 8 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a projection lens for a projection television, and more particularly relates to a wide angle type projection lens with a favorable optical performance, which is compact and low in cost, and which can be used for a very bright projection television with a value of F NO less than or equal to 1.15, or in the extreme case less than or equal to 1.1.
2. Description of the Related Art
In recent years the demand has increased for projection television systems, which are nowadays used not only for analog display of broadcast television images but also as analog displays for electronic image replaying mechanisms such as video tape recorders, video disk players, and the like. Projection televisions are also being used for display of digitalized picture data, in both character and graphical format, such as computer output and video text data. And recently large screen projection type televisions are becoming more and more popular even for general household use. Accordingly enhancements of brightness, contrast, and resolution for projection televisions are being strongly pursued, in order to bring their picture quality closer to that of normal direct vision type televisions, and concurrently pressures for compactness and cost reduction are very strong.
Further, the picture quality of a projection television is dictated by the performance of the projection lens used, and the projection lens is required to be capable of forming clear images not only around the optical axis but also in regions remote from the optical axis. From the view point of reducing the size and cost of the projection television, it is important to reduce the size and cost of the projection lens which is a major factor in determining the size and cost of the projection television.
In the prior art relating to projection lenses for projection televisions, although in a compound type projection lens there were combined together a large number of glass lenses, these glass lenses were in general spherical lenses, and accordingly the number of lenses in the combination became undesirably large, which entailed undue bulk and cost; and further, due to the specific gravity of glass being relatively high, the compound projection lens as a whole was rather heavy.
Recently, however, it has become possible to produce large aperture aspherical type plastic lenses with relatively high accuracy, and accordingly various compound projection lenses have been contemplated incorporating combinations of glass lenses and plastic lenses, whereby it is possible to maintain the optical performance at a high level while reducing bulk and cost.
Plastic lenses are generally manufactured by a process of injection molding using a metal mold, and for forming a high accuracy plastic lens as a matter of course a high accuracy metal mold must be used. Thus, although the introduction of such compound lens has contributed to the reduction in the cost of projection lenses through reduction in the number of lens elements used in each lens system and other factors, the high cost of the metallic molds cannot be justified in some applications.
In fact, with a currently manufactured mainstream type compound projection lens of the above described hybrid type in which both plastic and glass lenses are used, apart from the so called back lens which is the one of the lenses which is farthest from the screen (closest to the face plate of the CRT) and which is typically of negative power and presents a strongly concave surface towards the direction of the screen (in the direction away from the face plate of the CRT), typically four lenses are used, of which one is a glass lens which is of strongly positive power, and the other three are individually and independently formed plastic lenses. Accordingly, for the manufacture of such a compound projection lens, it is required initially to provide three different metal molds for making these three individual plastic lenses, which entails substantial initial cost.
Further, another problem with the prior art has been that, since the coefficient of linear expansion of plastic material is remarkably large as compared with that of optical glass and also the rate of change of refractive index of plastic material with change of temperature is also large, therefore the change of back focus for a plastic lens due to change of temperature is relatively great, and therefore its performance for image formation is deteriorated. With a projection television, this has caused the problem of picture quality deterioration. And, in view of the requirements for provision of an acceptable optical performance relating to geometrical optical aberration and the like and furthermore for wide angle performance and compactness, in the prior art there have been very few compound projection lenses for projection televisions which achieved a value of F NO less than or equal to 1.15.
SUMMARY OF THE INVENTION
Accordingly, an objective of the present invention is to provide a projection lens for a projection television of such a type including both plastic and glass lenses, with which the initial cost for setting up manufacturing is reduced.
Another objective of the present invention is to provide such a projection lens, with which the running costs of manufacturing are reduced.
Another objective of the present invention is to provide such a projection lens, with which (excluding the back lens) only two different metal molds for injection molding the plastic lenses are required, rather than the three or more which have been required in the prior art.
Another objective of the present invention is to provide such a projection lens, with which (excluding the back lens) four plastic lenses are incorporated in the combination, and yet only two different injection molding metal molds are required.
Yet another objective of the present invention is to provide such a projection lens, which has an acceptable optical performance.
Yet another objective of the present invention is to provide such a projection lens, which is a wide angle lens.
Yet another objective of the present invention is to provide such a projection lens, which is compact.
Yet another objective of the present invention is to provide such a projection lens, which is light in weight.
Yet another objective of the present invention is to provide such a projection lens, which has a value of F NO less than or equal to 1.15, or, more preferably, less than or equal to 1.1.
In order to attain these objectives, and others, one aspect of the present invention proposes a projection lens for a projection television comprising a CRT which comprises a face plate, comprising coaxially in order in the direction towards said face plate of said CRT: a first lens of negative power, both of whose surfaces are aspherical; a second lens of positive power, at least one of whose surfaces is aspherical, and formed of a plastic material; a third lens of positive power; a fourth lens of positive power, at least one of whose surfaces is aspherical, and formed of a plastic material; and a back lens of negative power, which presents in the direction away from said face plate of said CRT a face of strongly concave curvature; said third lens being the strongest in absolute power of said six lenses; and said second lens and said fourth lens having substantially the same optical characteristics, and being disposed in reverse orientation on opposite sides of said third lens; wherein the following conditions are satisfied: (1) 0.03<|f 2 /f 1 |<0.6; (2) 1.0<f 3 /f< 1.4; (3) D 2 /f<0.07; and (4) 2<E 1 /D 1 <4; in which: f is the overall focal length of the entire system; f i is the focal length of the ith one of said lenses; D 1 is the central thickness of said first lens; D 2 is the axial distance between the opposing surfaces of said first lens and said second lens; and E 1 is the distance between the two surfaces of said first lens along the edges of the ray furthest from the optical axis.
As subsidiary but important concepts for this aspect of the present invention, said first lens may be formed of a plastic material; said third lens may be formed of a glass material; and second lens and said fourth lens may be substantially identical in form and material. And the projection lens may further comprise a fifth lens both of whose surfaces are aspherical, having substantially the same optical characteristics as said first lens, and disposed in reverse orientation thereto between said fourth lens and said back lens; and in this case said fifth lens may be formed of a plastic material, and indeed said first lens and said fifth lens may be substantially identical in form and material.
And, in order to attain the above objectives, and others, another aspect of the present invention proposes a projection lens for a projection television comprising a CRT which comprises a face plate, comprising coaxially in order in the direction towards said face plate of said CRT: a first lens of negative power, both of whose surfaces are aspherical, and formed of a plastic material; a second lens of positive power, at least one of whose surfaces is aspherical, and formed of a plastic material; a third lens of positive power; a fourth lens of positive power, at least one of whose surfaces is aspherical, and formed of a plastic material; a fifth lens (back lens) of negative power which presents in the direction away from said face plate of said CRT a face of strongly concave curvature; said third lens being the strongest in absolute power of said first through fifth lenses; said first lens and said fifth lens having substantially the same optical characteristics, and being disposed in reverse orientation on opposite sides of said third lens; and said second lens and said fourth lens having substantially the same optical characteristics, and being disposed in reverse orientation on opposite sides of said third lens; wherein the following conditions are satisfied: (1) 0.03<|f 2 /f 1 |<0.6; (2) 1.0<f 3 /f<1.4; (3) D 2 /f<0.07; and (4) 2<E 1 /D 1 <4; in which: f is the overall focal length of the entire system; f i is the focal length of the ith one of said lenses; D 1 is the central thickness of said first lens; D 2 is the axial distance between the opposing surfaces of said first lens and said second lens; and E 1 is the distance between the two surfaces of said first lens along the edges of the ray furthest from the optical axis.
As subsidiary but important concepts for this aspect of the present invention, said first lens and said fifth lens may be substantially identical in form and material; said second lens and said fourth lens may be substantially identical in form and material; and one of said first lens and said second lens may be formed of substantially the same material as one of said fourth lens and said fifth lens. Further, said third lens may be formed of a glass material.
Now, an explanation will be given for the rationale of the four conditions specified in the above statements of aspects of the present invention.
Condition (1) is the condition which limits the distribution of power of the first lens and the second lens, and its observance contributes to compensation for spherical aberration and coma aberration which can occur with large aperture compound lenses like the projection lens of the present invention, and of course in some aspects of the present invention also the distribution of power of the fourth lens and the fifth lens. In detail, the projection lens according to the present invention is of a type which in recent years has become of very wide aperture, from the view point of compactness and also wider angle function, and both the first lens and the second lens have aspherical surfaces. The first lens contributes to compensation of coma aberration for upper light rays of wide angle. If |f 2 /f 1 |≧0.6, the spherical aberration is over-corrected; while on the other hand if the absolute value of the ratio between f 2 and f 1 becomes less than or equal to 0.03 then the spherical aberration is under-corrected; and in either case compensation of the spherical aberration becomes troublesome, and the lens performance is deteriorated.
Condition (2) is the condition which relates to the focal length of the third lens, which is the highest power of all the lenses in the construction. When the ratio of f 3 to f is greater than or equal to 1.4, i.e. when the power of the third lens is relatively weak, then in order to obtain the required focal length for the projection lens as a whole the power of some of the plastic lenses must be made quite strong, and either the aberration is made worse or alternatively the total length of the projection lens becomes long. Further, the temperature characteristics are deteriorated. What is meant by the temperature characteristics becoming deteriorated is alteration of back focus and deterioration of aberration which arise due to a relatively great change of refractive index with respect to change of temperature. On the other hand, when the ratio of f 3 to f is less than or equal to 1.0, i.e. when the power of the third lens is relatively strong, then spherical aberration and coma aberration arising due to this third lens are increased, and difficulties arise with regard to compensation for this aberration by the other lenses of the construction.
Condition (3) is the condition which limits the interval along the optical axis between the opposing surfaces of the first lens and the second lens. When the value of D 2 /f is greater than or equal to 0.07, i.e. when the axial interval between the opposing surfaces of the first lens and the second lens becomes relatively large, then the bundle of rays that is spread by the first lens becomes relatively wide, i.e. the diameter of the optical bundle of rays that impinges upon the second lens becomes relatively large, and this causes relatively high spherical aberration which it is difficult to compensate for.
Condition (4) is the condition which limits the ratio between the thickness of the first lens at its central portion and the distance between its two surfaces at the level of the edges of the ray furthest from the optical axis. This ratio may be called the thickness ratio. Although this first lens (and the fifth lens, if one is incorporated) is a lens of relatively small negative power as far as its portion near the optical axis is concerned, as the thickness of its peripheral portion due to curvature of its aspherical face is increased it becomes of greater negative power, and this first lens particularly functions for compensating for coma aberration of light rays which are far from the optical axis. When the ratio E 1 /D 1 becomes greater than or equal to 4, i.e. when the thickness ratio of the first lens becomes large, then both the spherical aberration and the coma aberration become over-corrected, and problems arise with compensation. Furthermore, the manufacture of the first lens by injection molding of plastic material becomes difficult, i.e. the formability of the lens is deteriorated. In general, for efficient injection molding of a plastic lens, it is desired for this thickness ratio to be small, and it has been found in practice that if the condition (4) is not satisfied it becomes difficult to form the plastic lens with sufficiently high accuracy, and further the manufacturing cost is undesirably increased. On the other hand, if the ratio E 1 /D 1 becomes less than or equal to 2, i.e. when the thickness ratio of the first lens becomes very low, then both the spherical aberration and the coma aberration become under-corrected, and again problems arise with compensation.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a lens structural diagram showing a side view of the first preferred embodiment of the projection lens of the present invention;
FIG. 2 is a figure showing the optical performance of said first preferred embodiment of the projection lens of the present invention, in which FIG. 2(a) is a spherical aberration diagram, FIG. 2(b) is an astigmatism diagram, and FIG. 2(c) is a distortion aberration diagram;
FIG. 3 is a figure showing the optical performance of the second preferred embodiment of the projection lens of the present invention, in which FIG. 3(a) is a spherical aberration diagram, FIG. 3(b) is an astigmatism diagram, and FIG. 3(c) is a distortion aberration diagram:
FIG. 4 is a figure showing the optical performance of the third preferred embodiment of the projection lens of the present invention, in which FIG. 4(a) is a spherical aberration diagram, FIG. 4(b) is an astigmatism diagram, and FIG. 4(c) is a distortion aberration diagram;
FIG. 5 is a lens structural diagram showing a side view of the fourth preferred embodiment of the projection lens of the present invention;
FIG. 6 is a figure showing the optical performance of said fourth preferred embodiment of the projection lens of the present invention, in which FIG. 6(a) is a spherical aberration diagram, FIG. 6(b) is an astigmatism diagram, and FIG. 6(c) is a distortion aberration diagram;
FIG. 7 is a figure showing the optical performance of the fifth preferred embodiment of the projection lens of the present invention, in which FIG. 7(a) is a spherical aberration diagram, FIG. 7(b) is an astigmatism diagram, and FIG. 7(c) is a distortion aberration diagram;
FIG. 8 is a lens structural diagram showing a side view of the sixth preferred embodiment of the projection lens of the present invention;
FIG. 9 is a figure showing the optical performance of said sixth preferred embodiment of the projection lens of the present invention, in which FIG. 9(a) is a spherical aberration diagram, FIG. 9(b) is an astigmatism diagram, and FIG. 9(c) is a distortion aberration diagram;
FIG. 10 is a figure showing the optical performance of the seventh preferred embodiment of the projection lens of the present invention, in which FIG. 10(a) is a spherical aberration diagram, FIG. 10(b) is an astigmatism diagram, and FIG. 10(c) is a distortion aberration diagram;
FIG. 11 is a figure showing the optical performance of the eighth preferred embodiment of the projection lens of the present invention, in which FIG. 11(a) is a spherical aberration diagram, FIG. 11(b) is an astigmatism diagram, and FIG. 11(c) is a distortion aberration diagram;
FIG. 12 is a lens structural diagram showing a side view of the ninth preferred embodiment of the projection lens of the present invention;
FIG. 13 is a figure showing the optical performance of said ninth preferred embodiment of the projection lens of the present invention, in which FIG. 13(a) is a spherical aberration diagram, FIG. 13(b) is an astigmatism diagram, and FIG. 13(c) is a distortion aberration diagram; and:
FIG. 14 is a figure showing the optical performance of the tenth preferred embodiment of the projection lens of the present invention, in which FIG. 14(a) is a spherical aberration diagram, FIG. 14(b) is an astigmatism diagram, and FIG. 14(c) is a distortion aberration diagram.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
General Discussion
In the following explanations, the symbol "r" denotes the radius of curvature of the face in question of a lens, the symbol "d" denotes lens thickness or the interval between lenses, and the symbol "n" denotes the e-line refractive index of the lens in question.
The form of each of the non-spherical lens surfaces is specified as follows. Each of these non-spherical lens surfaces is rotationally symmetric about the central optical axis of the projection lens as a whole, and its equation, with respect to a rectangular coordinate system in which said central optical axis of the projection lens is taken as the x-axis, is given by ##EQU1## where is as given by ##EQU2## Here, the symbol "C" denotes the paraxial curvature, the symbol "K" denotes the conical constant, and the symbols "A i " denote the non-spherical coefficients.
Preferred Embodiment 1
FIG. 1 is a lens structural diagram showing a side view of the first preferred embodiment of the projection lens of the present invention. This projection lens comprises first through fifth lenses L1 through L5 and a back lens L 6 (BL), of respective thicknesses d 1 , d 3 , d 5 , d 7 , d 9 , and d 11 , arranged coaxially in order from the left side of the figure, beyond which there is understood to be provided a projection screen for the projection television incorporating this projection lens, to the right side of the figure. The first lens L1, which has a left side surface r 1 and a right side surface r 2 , and the fifth lens L5, which has a left side surface r 9 and a right side surface r 10 , are substantially identical in form although positioned in opposite orientations on the optical axis and are both of generally negative power, and are both, in this preferred embodiment but not compulsorily, made of the same acrylic resin plastic material. And, similarly, the second lens L2, which has a left side surface r 3 and a right side surface r 4 , and the fourth lens L4, which has a left side surface r 7 and a right side surface r 8 , are substantially identical in form although positioned in opposite orientations on the optical axis and are both of generally positive power, and are both, in this preferred embodiment but not compulsorily, made of the same acrylic resin plastic material, which, in this preferred embodiment but not compulsorily, is the same material as the material for the first and the fifth lenses L1 and L5. The third lens L3, which has a left side surface r 5 and a right side surface r 6 , is of positive power and is the strongest in absolute power of all the five lenses L1 through L5, and is made of BK7 glass material. And the back lens L6 (BL) is of negative power, has a left side surface r 11 facing to the left in the figure which is strongly concave, has a right side surface denoted as r 12 , and is also made of an acrylic resin plastic material. Thus the five lenses L1 through L5 are disposed in reverse orientation about the third lens L3 as a center. The axial distance between the first lens L1 and the second lens L2 is d 2 ; the axial distance between the second lens L2 and the third lens L3 is d 4 ; the axial distance between the third lens L3 and the fourth lens L4 is d 6 ; the axial distance between the fourth lens L4 and the fifth lens L5 is d 8 ; and the axial distance between the fifth lens L5 and the back lens L6 (BL) is d 10 . Between the back lens L6 (BL) and a face plate T of a CRT (not fully shown) which is separated by an axial distance of d 12 therefrom, which has a left side surface r 13 and a right side surface r 14 and which is of thickness d 13 , there is interposed a liquid filler material M, which serves the functions of cooling the front of the face plate T and also of reducing reflection from the surfaces r 12 and r 13 of the face plate T and of the back lens L6 (BL) and thus improves contrast and prevents the generation of false images, bright spots, etc.. The provision of this liquid filler material M is not essential to the concept of the present invention; alternatively, the surface r 12 of the back lens L6 (BL) facing towards the face plate T of the CRT could be made planar, and air could be interposed in the space between said back lens L6 (BL) and said CRT face plate T.
FIGS. 2(a) through 2(c) are respectively a spherical aberration diagram, an astigmatism diagram, and a distortion aberration diagram for this projection lens according to the first preferred embodiment of the present invention.
For this projection lens: ##EQU3## And the radiuses of curvature r i of the faces of the lenses and of the CRT face plate T, the thicknesses d i of the lenses and of the CRT face plate T and the distances therebetween, and the e-line refractive indices n i of the lens materials of the lenses, in this first preferred embodiment, are as follows:
______________________________________r d n______________________________________1 -47.246 2.88 1.493682 -59.151 1.503 63.412 9.00 1.493684 138.883 6.505 85.402 23.00 1.516336 -83.629 8.007 -138.883 9.00 1.493688 -63.412 1.509 59.151 2.88 1.4936810 47.246 30.5811 -43.175 3.00 1.4936812 -48.200 8.00 1.44185 (liquid)13 -350.000 14.10 1.51633 (CRT face plate)14 -350.000______________________________________
The aspherical surfaces r 1 through r 12 (except r 5 and r 6 ) of the lenses L1 through L5 and BL (except L3) in this first preferred embodiment are defined by the following sets of coefficients:
______________________________________Surface no. 1 (r.sub.1): K 0 A.sub.4 0.104136E-04 A.sub.6 0.408716E-09 A.sub.8 -0.293510E-11 A.sub.10 0.974569E-15Surface no. 2 (r.sub.2): K 0 A.sub.4 0.107541E-04 A.sub.6 0.224534E-08 A.sub.8 -0.282207E-11 A.sub.10 0.857372E-15Surface no. 3 (r.sub.3): K 0 A.sub.4 -0.115632E-05 A.sub.6 0.569059E-09 A.sub.8 0.820709E-13 A.sub.10 -0.200090E-15Surface no. 4 (r.sub.4): K 0 A.sub.4 -0.976492E-06 A.sub.6 -0.316086E-09 A.sub.8 0.715141E-12 A.sub.10 -0.231902E-15Surface no. 7 (r.sub.7): K 0 A.sub.4 0.976492E-06 A.sub.6 0.316086E-09 A.sub.8 -0.715141E-12 A.sub.10 0.231902E-15Surface no. 8 (r.sub.8): K 0 A.sub.4 0.115632E-05 A.sub.6 -0.569059E-09 A.sub.8 -0.820709E-13 A.sub.10 0.200090E-15Surface no. 9 (r.sub.9): K 0 A.sub.4 - 0.107541E-04 A.sub.6 -0.224534E-08 A.sub.8 0.282207E-11 A.sub.10 -0.857372E-15Surface no. 10 (r.sub.10): K 0 A.sub.4 -0.104136E-04 A.sub.6 -0.408716E-09 A.sub.8 0.293510E-11 A.sub.10 -0.974569E-15Surface no. 11 (r.sub.11): K -0.122574E+01 A.sub.4 -0.280911E-05 A.sub.6 -0.105685E-08 A.sub.8 0.171171E-11 A.sub.10 -0.112879E-14Surface no. 12 (r.sub.12): K 0.190133E+00 A.sub.4 0 A.sub.6 0 A.sub.8 0 A.sub.10 0______________________________________
Preferred Embodiment 2
FIGS. 3(a) through 3(c) are respectively a spherical aberration diagram, an astigmatism diagram, and a distortion aberration diagram for this projection lens according to the second preferred embodiment of the present invention.
For this projection lens: ##EQU4## And the radiuses of curvature r i of the faces of the lenses and of the CRT face plate T, the thicknesses d i of the lenses and of the CRT face plate T and the distances therebetween, and the e-line refractive indices n i of the lens materials of the lenses, in this second preferred embodiment, are as follows:
______________________________________r d n______________________________________1 -41.761 2.47 1.493682 -52.483 2.683 77.032 9.00 1.493684 184.193 5.335 77.864 27.00 1.516336 -78.652 8.007 -184.193 9.00 1.493688 -77.032 2.689 52.483 2.47 1.4936810 41.761 30.0011 -50.370 3.00 1.4936812 -48.200 8.00 1.44185 (liquid)13 -350.000 14.10 1.51633 (CRT face plate)14 -350.000______________________________________
The aspherical surfaces r 1 through r 12 (except r 4 through r 7 ) of the lenses L1 through L5 and L6 (BL) in this second preferred embodiment (except the single spherical surfaces, in this embodiment, of the second and fourth lenses L2 and L4, and the two spherical surfaces of the third lens L3) are defined by the following sets of coefficients:
______________________________________Surface no. 1 (r.sub.1): K 0 A.sub.4 0.112516E-04 A.sub.6 -0.350637E-09 A.sub.8 -0.256154E-11 A.sub.10 0.129368E-14Surface no. 2 (r.sub.2): K 0 A.sub.4 0.110312E-04 A.sub.6 0.956368E-09 A.sub.8 -0.306231E-11 A.sub.10 0.131226E-14Surface no. 3 (r.sub.3): K 0 A.sub.4 -0.567376E-06 A.sub.6 0.859149E-09 A.sub.8 -0.850993E-12 A.sub.10 0.177449E-15Surface no. 8 (r.sub.8): K 0 A.sub.4 0.567376E-06 A.sub.6 -0.859149E-09 A.sub.8 0.850993E-12 A.sub.10 -0.177449E-15Surface no. 9 (r.sub.9): K 0 A.sub.4 -0.110312E-04 A.sub.6 -0.956368E-09 A.sub.8 0.306231E-11 A.sub.10 -0.131226E-14Surface no. 10 (r.sub.10): K 0 A.sub.4 -0.112516E-04 A.sub.6 0.350637E-09 A.sub.8 0.256154E-11 A.sub.10 -0.129368E-14 Surface no. 11 (r.sub.11): K 0.573241E+00 A.sub.4 -0.330274E-05 A.sub.6 0.452280E-08 A.sub.8 -0.341917E-11 A.sub.10 0.938636E-15Surface no. 12 (r.sub.12): K 0.242159E+00 A.sub.4 0 A.sub.6 0 A.sub.8 0 A.sub.10 0______________________________________
Preferred Embodiment 3
FIGS. 4(a) through 4(c) are respectively a spherical aberration diagram, an astigmatism diagram, and a distortion aberration diagram for this projection lens according to the third preferred embodiment of the present invention.
For this projection lens: ##EQU5## And the radiuses of curvature r i of the faces of the lenses and of the CRT face plate T, the thicknesses d i of the lenses and of the CRT face plate T and the distances therebetween, and the e-line refractive indices n i of the lens materials of the lenses, in this third preferred embodiment, are as follows:
______________________________________r d n______________________________________1 -49.862 2.44 1.493682 -58.799 5.003 78.536 9.00 1.493684 170.877 7.505 111.217 28.00 1.516336 -107.130 9.607 -170.877 9.00 1.493688 -78.536 5.209 58.799 2.44 1.4936810 49.862 37.9711 -60.973 3.00 1.4936812 -57.840 12.00 1.44185 (liquid)13 -350.000 14.10 1.51633 (CRT face plate)14 -350.000______________________________________
The aspherical surfaces r 1 through r 12 (except r 5 and r 6 ) of the lenses L1 through L5 and L6 (BL) (except L3) in this third preferred embodiment are defined by the following sets of coefficients:
______________________________________Surface no. 1 (r.sub.1): K 0 A.sub.4 0.773189E-05 A.sub.6 -0.325927E-09 A.sub.8 -0.825162E-12 A.sub.10 0.286335E-15Surface no. 2 (r.sub.2): K 0 A.sub.4 0.790306E-05 A.sub.6 0.888739E-10 A.sub.8 -0.825455E-12 A.sub.10 0.275969E-15Surface no. 3 (r.sub.3): K 0 A.sub.4 -0.340034E-06 A.sub.6 0.117741E-09 A.sub.8 -0.473105E-13 A.sub.10 0.185531E-17Surface no. 4 (r.sub.4): K 0 A.sub.4 -0.263603E-06 A.sub.6 0.229125E-10 A.sub.8 0.359616E-13 A.sub.10 -0.595138E-17Surface no. 7 (r.sub.7): K 0 A.sub.4 0.263603E-06 A.sub.6 -0.229125E-10 A.sub.8 -0.359616E-13 A.sub.10 0.595138E-17Surface no. 8 (r.sub.8): K 0 A.sub.4 0.340034E-06 A.sub.6 -0.117741E-09 A.sub.8 0.473105E-13 A.sub.10 -0.185531E-17Surface no. 9 (r.sub.9): K 0 A.sub.4 -0.790306E-05 A.sub.6 -0.888739E-10 A.sub.8 0.825455E-12 A.sub.10 -0.275969E-15Surface no. 10 (r.sub.10): K 0 A.sub.4 -0.773189E-05 A.sub.6 0.325927E-09 A.sub.8 0.825162E-12 A.sub.10 -0.286335E-15Surface no. 11 (r.sub.11): K 0.490315E+00 A.sub.4 -0.135388E-05 A.sub.6 0.127895E-08 A.sub.8 -0.670598E-12 A.sub.10 0.142500E-15Surface no. 12 (r.sub.12): K -0.189142E-01 A.sub.4 0 A.sub.6 0 A.sub.8 0 A.sub.10 0______________________________________
Preferred Embodiment 4
FIG. 5 is a lens structural diagram showing a side view of the fourth preferred embodiment of the projection lens of the present invention. This projection lens comprises first through sixth lenses L1 through L5 and L6 (BL) of respective thicknesses d 1 , d 3 , d 5 , d 7 , d 9 , and d 11 , arranged coaxially in order from the left side of the figure, beyond which there is again understood to be provided a projection screen for the projection television incorporating this projection lens, to the right side of the figure. The first lens L1, which has a left side surface r 1 and a right side surface r 2 , and the fifth lens L5, which has a left side surface r 9 and a right side surface r 10 , are substantially identical in form although positioned in opposite orientations on the optical axis and are both of generally negative power, and are both made of the same acrylic resin plastic material. And, similarly, the second lens L2, which has a left side surface r 3 and a right side surface r 4 , and the fourth lens L4, which has a left side surface r 7 and a right side surface r 8 , are substantially identical in form although positioned in opposite orientations on the optical axis and are both of generally positive power, and are both made of the same acrylic resin plastic material. The third lens L3, which has a left side surface r 5 and a right side surface r 6 , is of positive power and is the strongest in absolute power of all the five lenses L1 through L5, and is made of BK7 glass material. And the back lens L6 (BL) is of negative power, has a left side surface r 11 facing to the left in the figure which is strongly convex, has a right side surface denoted as r 12 , and is also made of an acrylic resin plastic material. Thus the five lenses L1 through L5 are disposed in reverse orientation about the third lens L3 as a center. The axial distance between the first lens L1 and the second lens L2 is d 2 ; the axial distance between the second lens L2 and the third lens L3 is d 4 ; the axial distance between the third lens L3 and the fourth lens L4 is d 6 ; the axial distance between the fourth lens L4 and the fifth lens L5 is d 8 ; and the axial distance between the fifth lens L5 and the back lens L6 (BL) is d 10 . Between the back lens L6 (BL) and a face plate T of a CRT (not fully shown) which is separated by an axial distance of d 12 therefrom, which has a left side surface r 13 and a right side surface r 14 and which is of thickness d 13 , there is interposed a liquid filler material M of the same type and having the same function as in the first preferred embodiment described above.
FIGS. 6(a) through 6(c) are respectively a spherical aberration diagram, an astigmatism diagram, and a distortion aberration diagram for this projection lens according to the fourth preferred embodiment of the present invention.
For this projection lens: ##EQU6## And the radiuses of curvature r i of the faces of the lenses and of the CRT face plate T, the thicknesses d i of the lenses and of the CRT face plate T and the distances therebetween, and the e-line refractive indices n i of the lens materials of the lenses, in this fourth preferred embodiment, are as follows:
______________________________________r d n______________________________________1 -54.558 4.36 1.493682 -56.625 3.433 61.581 9.00 1.493684 80.293 5.355 98.089 28.30 1.516336 -96.466 9.607 -80.293 9.00 1.493688 -61.581 3.419 56.625 4.36 1.4936810 54.558 34.9911 -43.114 3.00 1.4936812 -45.017 12.00 1.44185 (liquid)13 infinite 14.10 1.51633 (CRT face plate)14 infinite______________________________________
The aspherical surfaces r 1 through r 12 (except r 5 and r 6 ) of the lenses L1 through L5 and L6 (BL) (except L3) in this fourth preferred embodiment are defined by the following sets of coefficients:
______________________________________Surface no. 1 (r.sub.1):K 0A.sub.4 0.457812E-05A.sub.6 0.233838E-08A.sub.8 -0.150669E-11A.sub.10 0.262942E-15Surface no. 2 (r.sub.2):K 0A.sub.4 0.563548E-05A.sub.6 0.242488E-08A.sub.8 -0.116131E-11A.sub.10 0.273798E-15Surface no. 3 (r.sub.3):K 0A.sub.4 -0.145107E-05A.sub.6 0.249198E-09A.sub.8 0.723499E-13A.sub.10 -0.150023E-15Surface no. 4 (r.sub.4):K 0A.sub.4 -0.223396E-05A.sub.6 0.753736E-09A.sub.8 -0.693895E-13A.sub.10 -0.104407E-15Surface no. 7 (r.sub.7):K 0A.sub.4 0.223396E-05A.sub.6 -0.753736E-09A.sub.8 0.693895E-13A.sub.10 0.104407E-15Surface no. 8 (r.sub.8):K 0A.sub.4 0.145107E-05A.sub.6 -0.249198E-09A.sub.8 -0.723499E-13A.sub.10 0.150023E-15Surface no. 9 (r.sub.9):K 0A.sub.4 -0.563548E-05A.sub.6 -0.242488E-08A.sub.8 0.116131E-11A.sub.10 -0.273798E-15Surface no. 10 (r.sub.10):K 0A.sub.4 -0.457812E-05A.sub. 6 -0.233838E-08A.sub.8 0.150669E-11A.sub.10 -0.262942E-15Surface no. 11 (r.sub.11):K 0.201919E-01A.sub.4 -0.230718E-05A.sub.6 0.374625E-08A.sub.8 -0.241349E-11A.sub.10 0.641452E-15Surface no. 12 (r.sub.12):K -0.100000E+00A.sub.4 0A.sub.6 0A.sub.8 0A.sub.10 0______________________________________
Preferred Embodiment 5
FIGS. 7(a) through 7(c) are respectively a spherical aberration diagram, an astigmatism diagram, and a distortion aberration diagram for this projection lens according to the fifth preferred embodiment of the present invention.
For this projection lens: ##EQU7## And the radiuses of curvature r i of the faces of the lenses and of the CRT face plate T, the thicknesses d i of the lenses and of the CRT face plate T and the distances therebetween, and the e-line refractive indices n i of the lens materials of the lenses, in this fifth preferred embodiment, are as follows:
______________________________________r d n______________________________________1 -50.282 5.50 1.493682 -57.236 4.673 73.564 9.00 1.493684 116.238 4.215 98.971 32.00 1.516336 -98.420 9.607 -116.238 9.00 1.493688 -73.564 4.679 57.236 5.50 1.4936810 50.282 33.4811 -50.135 15.00 1.4936812 infinity 14.10 1.51633 (CRT face plate)13 infinity______________________________________
The aspherical surfaces r 1 through r 11 (except r 5 and r 6 ) of the lenses L1 through L5 and BL (except L3) in this fifth preferred embodiment are defined by the following sets of coefficients:
______________________________________Surface no. 1 (r.sub.1): K 0 A.sub.4 0.508341E-05 A.sub.6 0.148481E-08 A.sub.8 -0.134567E-11 A.sub.10 0.342177E-15Surface no. 2 (r.sub.2): K 0 A.sub.4 0.568487E-05 A.sub.6 0.178970E-08 A.sub.8 -0.133563E-11 A.sub.10 0.367078E-15Surface no. 3 (r.sub.3): K 0 A.sub.4 -0.922801E-06 A.sub.6 0.247224E-09 A.sub.8 0.862530E-14 A.sub.10 -0.942701E-16Surface no. 4 (r.sub.4): K 0 A.sub.4 -0.155950E-05 A.sub.6 0.656939E-09 A.sub.8 -0.604272E-13 A.sub.10 -0.793691E-16Surface no. 7 (r.sub.7): K 0 A.sub.4 0.155950E-05 A.sub.6 -0.656939E-09 A.sub.8 0.604272E-13 A.sub.10 0.793691E-16Surface no. 8 (r.sub.8): K 0 A.sub.4 0.922801E-06 A.sub.6 -0.247224E-09 A.sub.8 -0.862530E-14 A.sub.10 0.942701E-16Surface no. 9 (r.sub.9): K 0 A.sub.4 -0.568487E-05 A.sub.6 -0.178970E-08 A.sub.8 0.133563E-11 A.sub.10 -0.367078E-15Surface no. 10 (r.sub.10): K 0 A.sub.4 -0.508341E-05 A.sub.6 -0.148481E-08 A.sub.8 0.134567E-11 A.sub.10 -0.342177E-15Surface no. 11 (r.sub.11): K 0.354429E+00 A.sub.4 -0.213021E-05 A.sub.6 0.286991E-08 A.sub.8 -0.191075E-11 A.sub.10 0.504101E-15______________________________________
Embodiments 6 Through 10
Now, preferred embodiments 6 through 10 of the present invention will be described.
In the following explanations, as before, the symbol "r" denotes the radius of curvature of the face in question of a lens, the symbol "d" denotes lens thickness or the interval between lenses, and the symbol "n" denotes the e-line refractive index of the lens in question.
The forms of some of the aspherical lens surfaces are specified as described earlier; but the forms of some of the others are specified as follows. Each of these aspherical lens surfaces is rotationally symmetric about the central optical axis of the projection lens as a whole, and its equation, with respect to a rectangular coordinate system in which said central optical axis of the projection lens is taken as the x-axis, is given by ##EQU8## where is as given by ##EQU9##
Here, the symbol "C" denotes the paraxial curvature, the symbol "K" denotes the conical constant, and the symbols "A i " denote the aspherical coefficients.
Preferred Embodiment 6
FIG. 8 is a lens structural diagram showing a side view of the sixth preferred embodiment of the projection lens of the present invention. This projection lens comprises first through fourth lenses L1 through L4 and a back lens L5 (BL), of respective thicknesses d 1 , d 3 , d 5 , d 7 , and d 9 , arranged coaxially in order from the left side of the figure, beyond which there is again understood to be provided a projection screen for the projection television incorporating this projection lens, to the right side of the figure. The first lens L1, which has a left side surface t 1 and a right side surface r 2 , is of generally negative power, and is made of acrylic resin plastic material. And the second lens L2, which has a left side surface r 3 and a right side surface r 4 , and the fourth lens L4, which has a left side surface r 7 and a right side surface r 8 , are substantially identical in form although positioned in opposite orientations on the optical axis and are both of generally positive power, and are both made of the same acrylic resin plastic material. The third lens L3, which has a left side surface r 5 and a right side surface r 6 , is of positive power and is the strongest in absolute power of all the four lenses L1 through L4, and is made of BK7 glass material. And the back lens L5 (BL) is of negative power, has a left side surface r 9 facing to the left in the figure which is strongly convex, and a right side surface denoted as r 10 , and is also made of an acrylic resin plastic material. Thus the two lenses L2 and L4 are disposed in reverse orientation about the third lens L3 as a center, and both of the faces of the first lens L1 are aspherical surfaces, while at least one of the faces of the second lens L2 (and of the fourth lens L4 which is substantially identical thereto) is a aspherical surface. The axial distance between the first lens L1 and the second lens L2 is d 2 ; the axial distance between the second lens L2 and the third lens L3 is d 4 ; the axial distance between the third lens L3 and the fourth lens L4 is d 6 ; and the axial distance between the fourth lens L4 and the back lens L5 (BL) is d 8 . Between the back lens BL and a face plate T of a CRT (not fully shown) which is separated by an axial distance of d 10 therefrom, which has a left side surface t 11 and a right side surface t 12 and which is of thickness d 11 , there is interposed a liquid filler material M, which has the functions mentioned in connection with previous preferred embodiments of this invention.
FIGS. 9(a) through 9(c) are respectively a spherical aberration diagram, an astigmatism diagram, and a distortion aberration diagram for this projection lens according to the sixth preferred embodiment of the present invention.
For this projection lens: ##EQU10## And the radiuses of curvature r i of the faces of the lenses and of the CRT face plate T, the thicknesses d i of the lenses and of the CRT face plate T and the distances therebetween, and the e-line refractive indices n i of the lens materials of the lenses, in this sixth preferred embodiment, are as follows:
______________________________________r d n______________________________________1 -52.16 2.70 1.4942 -67.42 0.20 1.0003 86.74 8.20 1.4944 263.20 8.31 1.0005 95.76 27.00 1.5166 -98.60 16.60 1.0007 -263.20 8.20 1.4948 -86.74 35.98 1.0009 -50.90 3.00 1.49410 -53.50 10.00 1.440 (liquid)11 infinity 13.00 1.560 (CRT face plate)12 -350.00______________________________________
The aspherical surfaces r 1 through r 10 (except r 5 and r 6 ) of the lenses L1 through L4 and L5 (BL) (except L3) in this sixth preferred embodiment are defined by the following sets of coefficients:
______________________________________Surface no. 1 (r.sub.1):K 0A.sub.3 0A.sub.4 0.5907E-05A.sub.5 0A.sub.6 -0.7798E-09A.sub.7 0A.sub.8 -0.1071E-12A.sub.9 0A.sub.10 0.8477E-16Surface no. 2 (r.sub.2):K 0A.sub.3 0.1851E-04A.sub.4 0.7882E-05A.sub.5 -0.4486E-06A.sub.6 0.2779E-07A.sub.7 -0.8364E-09A.sub.8 0.1017E-10A.sub.9 0A.sub.10 -0.6485E-15Surface no. 3 (r.sub.3):K 0A.sub.3 0A.sub.4 -0.1964E-06A.sub.5 0A.sub.6 0.4046E-10A.sub.7 0A.sub.8 -0.3100E-12A.sub.9 0A.sub.10 -0.1443E-16Surface no. 4 (r.sub.4):K 0A.sub.3 0A.sub.4 0.4589E-06A.sub.5 0A.sub.6 -0.1216E-09A.sub.7 0A.sub.8 -0.2086E-12A.sub.9 0A.sub.10 -0.1763E-16Surface no. 7 (r.sub.7):K 0A.sub.3 0A.sub.4 -0.4589E-06A.sub.5 0A.sub.6 0.1216E-09A.sub.7 0A.sub.8 0.2086E-12A.sub.9 0A.sub.10 0.1763E-16Surface no. 8 (r.sub. 8):K 0A.sub.3 0A.sub.4 0.1964E-06A.sub.5 0A.sub.6 -0.4046E-10A.sub.7 0A.sub.8 0.3100E-12A.sub.9 0A.sub.10 0.1443E-16Surface no. 9 (r.sub.9):K 0.2668A.sub.3 0A.sub.4 -0.3224E-05A.sub.5 0A.sub.6 0.1453E-08A.sub.7 0A.sub.8 -0.4666E-12A.sub.9 0A.sub.10 -0.2333E-16-Surface no. 10 (r.sub.10):K 0.2668A.sub.3 0A.sub.4 -0.2673E-05A.sub.5 0A.sub.6 0.1623E-08A.sub.7 0A.sub.8 -0.7558E-12A.sub.9 0A.sub.10 -0.1067E-15______________________________________
Preferred Embodiment 7
FIGS. 10(a) through 10(c) are respectively a spherical aberration diagram, an astigmatism diagram, and a distortion aberration diagram for this projection lens according to the seventh preferred embodiment of the present invention.
For this projection lens: ##EQU11## And the radiuses of curvature r i of the faces of the lenses and of the CRT face plate T, the thicknesses d i of the lenses and of the CRT face plate T and the distances therebetween, and the e-line refractive indices n i of the lens materials of the lenses, in this seventh preferred embodiment, are as follows:
______________________________________r d n______________________________________1 -51.85 5.00 1.4942 -64.96 0.30 1.0003 79.46 8.56 1.4944 222.00 7.13 1.0005 111.23 27.00 1.5166 -111.23 12.77 1.0007 -222.00 8.56 1.4948 -79.46 40.69 1.0009 -58.92 3.00 1.49410 -58.00 10.00 1.440 (liquid)11 infinity 13.00 1.560 (CRT face plate)12 -350.00______________________________________
The aspherical surfaces r 1 through r 10 (except r 4 through r 7 ) of the lenses L1 through L4 and L5 (BL) in this seventh preferred embodiment (except the single spherical surfaces, in this embodiment, of the second and fourth lenses L2 and L4, and the two spherical surfaces of the third lens L3) are defined by the following sets of coefficients:
______________________________________Surface no. 1 (r.sub.1):K 0A.sub.3 -0.1522E-03A.sub.4 0.1875E-04A.sub.5 -0.6976E-06A.sub.6 0.1718E-07A.sub.7 -0.1476E-09A.sub.8 -0.9585E-12A.sub.9 0A.sub.10 0.3251E-15Surface no. 2 (r.sub.2):K 0A.sub.3 -0.8311E-4A.sub.4 0.1197E-04A.sub.5 -0.3780E-06A.sub.6 0.8085E-08A.sub.7 0.3092E-10A.sub.8 -0.2827E-11A.sub.9 0A.sub.10 0.4570E-15Surface no. 3 (r.sub.3):K 0A.sub.4 -0.6672E-06A.sub.6 0.3683E-09A.sub.8 -0.2578E-12A.sub.10 -0.5576E-16Surface no. 8 (r.sub.8):K 0A.sub.4 0.6672E-06A.sub.6 -0.3683E-09A.sub.8 0.2578E-12A.sub.10 -0.5576E-16Surface no. 9 (r.sub.9):K 0.2668A.sub.4 -0.3882E-05A.sub.6 0.1105E-08A.sub.8 -0.2497E-12A.sub.10 -0.1489E-15Surface no. 10 (r.sub.10):K 0.2668A.sub.4 -0.2673E-05A.sub.6 0.1623E-08A.sub.8 -0.7558E-12A.sub.10 0.1067E-15______________________________________
Preferred Embodiment 8
FIGS. 11(a) through 11(c) are respectively a spherical aberration diagram, an astigmatism diagram, and a distortion aberration diagram for this projection lens according to the eighth preferred embodiment of the present invention.
For this projection lens: ##EQU12## And the radiuses of curvature r i of the faces of the lenses and of the CRT face plate T, the thicknesses d i of the lenses and of the CRT face plate T and the distances therebetween, and the e-line refractive indices n i of the lens materials of the lenses, in this eighth preferred embodiment, are as follows:
______________________________________r d n______________________________________1 -50.29 4.31 1.4942 -67.29 4.07 1.0003 78.66 9.00 1.4944 226.99 6.45 1.0005 100.30 24.17 1.5166 -112.64 11.40 1.0007 -226.99 9.00 1.4948 -78.66 40.29 1.0009 -58.86 15.00 1.49410 infinity 13.00 1.560 (CRT face plate)11 -350.00______________________________________
The aspherical surfaces r 1 through r 9 (except r 5 and r 6 ) of the lenses L1 through L4 and BL (except L3) in this eighth preferred embodiment are defined by the following sets of coefficients:
______________________________________Surface no. 1 (r.sub.1):K 0A.sub.4 0.4413E-05A.sub.6 0.9625E-09A.sub.8 -0.9729E-12A.sub.10 0.2774E-15Surface no. 2 (r.sub.2):K 0A.sub.4 0.4131E-05A.sub.6 0.1265E-08A.sub.8 -0.1010E-11A.sub.10 0.2592E-15Surface no. 3 (r.sub.3):K 0A.sub.4 0.1445E-06A.sub.6 -0.4329E-09A.sub.8 0.3740E-12A.sub.10 -0.1329E-15Surface no. 4 (r.sub.4):K 0A.sub.4 0.7886E-06A.sub.6 -0.6261E-09A.sub.8 0.5590E-12A.sub.10 -0.1728E-15Surface no. 7 (r.sub.7):K 0A.sub.4 -0.7886E-06A.sub.6 0.6261E-09A.sub.8 -0.5590E-12A.sub.10 0.1728E-15Surface no. 8 (r.sub.8):K 0A.sub.4 -0.1445E-06A.sub.6 0.4329E-09A.sub.8 -0.3740E-12A.sub.10 0.1329E-15Surface no. 9 (r.sub.9):K 0.7569A.sub.4 -0.3700E-05A.sub.6 0.2014E-08A.sub.8 -0.1268E-11A.sub.10 0.2686E-15______________________________________
Preferred Embodiment 9
FIG. 12 is a lens structural diagram showing a side view of the ninth preferred embodiment of the projection lens of the present invention. This projection lens comprises first through fourth lenses L1 through L4 and L5 (BL) of respective thicknesses d 1 , d 3 , d 5 , d 7 , and d 9 , arranged coaxially in order from the left side of the figure, beyond which there is again understood to be provided a projection screen for the projection television incorporating this projection lens, to the right side of the figure. The first lens L1, which has a left side surface r 1 and a right side surface r 2 , is of generally negative power, and is made of acrylic resin plastic material. And the second lens L2, which has a left side surface r 3 and a right side surface r 4 , and the fourth lens L4, which has a left side surface r 7 and a right side surface r 8 , are substantially identical in form although positioned in opposite orientations on the optical axis and are both of generally positive power, and are both made of the same acrylic resin plastic material. The third lens L3, which has a left side surface r 5 and a right side surface r 6 , is of positive power and is the strongest in absolute power of all the four lenses L1 through L4, and is made of BK7 glass material. And the back lens L5 (BL) is of negative power, has a left side surface r 9 facing to the left in the figure which is strongly convex, and a right side surface denoted as r 10 , and is also made of an acrylic resin plastic material. Thus the two lenses L2 and L4 are disposed in reverse orientation about the third lens L3 as a center. The axial distance between the first lens L1 and the second lens L2 is d 2 ; the axial distance between the second lens L2 and the third lens L3 is d 4 ; the axial distance between the third lens L3 and the fourth lens L4 is d 6 ; and the axial distance between the fourth lens L4 and the back lens BL is d 8 . Between the back lens L5 (BL) and a face plate T of a CRT (not fully shown) which is separated by an axial distance of d 10 therefrom, which has a left side surface r 11 and a right side surface r 12 and which is of thickness d 11 , there is interposed a liquid filler material M, which has the functions mentioned in connection with previous preferred embodiments of this invention.
FIGS. 13(a) through 13(c) are respectively a spherical aberration diagram, an astigmatism diagram, and a distortion aberration diagram for this projection lens according to the ninth preferred embodiment of the present invention.
For this projection lens: ##EQU13## And the radiuses of curvature r i of the faces of the lenses and of the CRT face plate T, the thicknesses d i of the lenses and of the CRT face plate T and the distances therebetween, and the refractive indices n i of the lens materials of the lenses along the optical axis, in this ninth preferred embodiment, are as follows:
______________________________________r d n______________________________________1 -51.00 3.50 1.4942 -57.67 0.50 1.0003 59.21 8.20 1.4944 79.46 8.31 1.0005 78.00 29.20 1.5166 -83.70 16.60 1.0007 -79.46 8.20 1.4948 -59.21 32.40 1.0009 -50.15 3.00 1.49410 -53.16 10.00 1.440 (liquid)11 infinity 13.00 1.560 (CRT face plate)12 -350.00______________________________________
The aspherical surfaces r 1 through r 10 (except r 5 and r 6 ) of the lenses L1 through L4 and BL (except L3) in this ninth preferred embodiment are defined by the following sets of coefficients:
______________________________________Surface no. 1 (r.sub.1):K 0A.sub.3 -0.8821E-05A.sub.4 0.4130E-05A.sub.5 -0.4454E-08A.sub.6 0.4662E-09A.sub.7 0.4840E-11A.sub.8 -0.1982E-12A.sub.9 0A.sub.10 0.2874E-16Surface no. 2 (r.sub.2):K 0A.sub.3 0.2774E-04A.sub.4 0.4518E-05A.sub.5 -0.3827E-06A.sub.6 0.2776E-07A.sub.7 -0.8422E-09A.sub.8 0.1079E-10A.sub.9 0A.sub.10 -0.7968E-15Surface no. 3 (r.sub.3):K 0A.sub.4 0.9520E-07A.sub.6 -0.5067E-09A.sub.8 0.4715E-13A.sub.10 -0.7012E-16Surface no. 4 (r.sub.4):K 0A.sub.4 0.1237E-05A.sub.6 -0.4454E-09A.sub.8 0.1228E-13A.sub.10 -0.2238E-16Surface no. 7 (r.sub.7):K 0A.sub.4 -0.1237E-05A.sub.6 0.4454E-09A.sub.8 -0.1228E-13A.sub.10 0.2238E-16Surface no. 8 (r.sub.8):K 0A.sub.4 -0.9520E-07A.sub.6 0.5067E-09A.sub.8 -0.4715E-13A.sub.10 0.7012E-16Surface no. 9 (r.sub.9):K 0.2668A.sub.4 -0.6582E-06A.sub.6 -0.3121E-08A.sub.8 0.3266E-11A.sub.10 -0.1351E-14Surface no. 10 (r.sub.10):K 0.2668A.sub.4 -0.2673E-05A.sub.6 0.1623E-08A.sub.8 -0.7558E-12A.sub.10 -0.1067E-15______________________________________
Preferred Embodiment 10
FIGS. 14(a) through 14(c) are respectively a spherical aberration diagram, an astigmatism diagram, and a distortion aberration diagram for this projection lens according to the tenth preferred embodiment of the present invention.
For this projection lens: ##EQU14## And the radiuses of curvature r i of the faces of the lenses and of the CRT face plate T, the thicknesses d i of the lenses and of the CRT face plate T and the distances therebetween, and the e-line refractive indices n i of the lens materials of the lenses, in this tenth preferred embodiment, are as follows:
______________________________________r d n______________________________________1 -84.92 4.00 1.4942 -86.72 0.20 1.0003 77.03 8.20 1.4944 149.59 8.31 1.0005 134.08 27.00 1.5166 -79.27 16.60 1.0007 -149.59 8.20 1.4948 -77.03 33.27 1.0009 -49.50 3.00 1.49410 -53.16 10.00 1.440 (liquid)11 infinity 13.00 1.560 (CRT face plate)12 -350.00______________________________________
The aspherical surfaces r 1 through r 10 (except r 5 and r 6 ) of the lenses L1 through L4 and L5 (BL) (except L3) in this tenth preferred embodiment are defined by the following sets of coefficients:
______________________________________Surface no. 1 (r.sub.1):K 0A.sub.4 -0.1050E-05A.sub.6 0.3132E-08A.sub.8 -0.7792E-12A.sub.10 -0.6978E-17Surface no. 2 (r.sub.2):K 0A.sub.3 0.2567E-04A.sub.4 -0.6995E-06A.sub.5 -0.1724E-06A.sub.6 0.1668E-07A.sub.7 -0.4157E-09A.sub.8 0.4494E-11A.sub.9 0A.sub.10 -0.2395E-15Surface no. 3 (r.sub.3):K 0A.sub.4 -0.1016E-05A.sub.6 0.1237E-09A.sub.8 -0.2943E-12A.sub.10 -0.2928E-16Surface no. 4 (r.sub.4):K 0A.sub.4 -0.9739E-07A.sub.6 -0.7477E-09A.sub.8 0.3519E-12A.sub.10 -0.1871E-15Surface no. 7 (r.sub.7):K 0A.sub.4 0.9739E-07A.sub.6 0.7477E-09A.sub.8 -0.3519E-12A.sub.10 0.1871E-15Surface no. 8 (r.sub.8):K 0A.sub.4 0.1016E-05A.sub.6 -0.1237E-09A.sub.8 0.2943E-12A.sub.10 0.2928E-16Surface no. 9 (r.sub.9):K 0.3A.sub.4 -0.3759E-05A.sub.6 0.3757E-08A.sub.8 -0.2154E-11A.sub.10 -0.4817E-15Surface no. 10 (r.sub.10):K 0.3A.sub.4 -0.2673E-05A.sub.6 0.1623E-08A.sub.8 -0.7860E-12A.sub.10 -0.1070E-15______________________________________
CONCLUSION
Thus, it is seen that, according to the present invention, there is provided a projection lens for a projection television, including both plastic and glass lenses, with which the initial cost for setting up manufacturing is reduced, and with which, further, the running costs of manufacturing are reduced. This is because, (excluding the back lens BL) only two different metal molds for injection molding the plastic lenses L1, L2, L4 and possibly L5 are required in the present invention, rather than the three or more which were required in the prior art, although (excluding the back lens BL) either three or four plastic lenses are incorporated in the construction. And, further, it is seen that this projection lens is wide angle and has an acceptable optical performance and is compact and light in weight, and can have a value of F NO less than or equal to 1.15, and even in the optimal case a value of F NO less than or equal to 1.1.
The present invention has been shown and described in terms of several preferred embodiments thereof, but is not to be considered as limited by any of the perhaps quite fortuitous details of said embodiments or of the drawings, but only by the terms of the appended claims, which follow. | This projection lens for a projection television includes coaxially in order towards the face plate of the CRT: a first lens of negative power, both of whose surfaces are aspherical; a second lens of positive power, at least one of whose surfaces is aspherical, formed of a plastic material; a third lens of positive power; a fourth lens of positive power, at least one of whose surfaces is aspherical, formed of a plastic material; and a back lens of negative power, which presents in the direction away from the face plate of the CRT a face of strongly concave curvature. The third lens is the strongest of the lenses in absolute power, and the second lens and the fourth lens have substantially the same optical characteristics, and are disposed in reverse orientation on opposite sides of the third lens. Certain conditions relating to lens parameters should be satisfied for acceptable optical performance. It is anticipated that the second lens and the fourth lens will be manufactured from plastic material by using the same metal mold for injection molding, which provides highly desirable cost economy for manufacturing setup. | 6 |
[0001] This application relates to U.S. Pat. No. 8,465,087, filed Mar. 23, 2010 and issued Jun. 18, 2013, which claims benefit under 35 U.S.C. §119(e) from provisional application Ser. No. 61/164,700, filed Mar. 30, 2009, entitled ENERGY ABSORBER WITH ANTI-SQUEAK ANTI-RATTLE FEATURE, the entire contents of which applications are incorporated herein by reference.
BACKGROUND
[0002] 1. (1) Technical Field
[0003] The present invention relates to recoverable energy absorbers, such as are used non-destructively and re-usably for absorbing energy in automotive and non-automotive applications.
[0004] 2. (2) Background Art
[0005] Vehicle manufacturers spend considerable time and effort to eliminate BSR noises because they can be very irritating and annoying to vehicle drivers and passengers, particularly when the BSR noises come from a location close to a passenger's head, and/or any component in the vehicle's passenger compartment, especially when the noises are created near or are amplified by components that effectively form an echo chamber.
[0006] Many different geometrically shaped thermoformed energy absorbers are known, such as those described in U.S. Pat. Nos. 6,017,084; 6,221,292; 6,199,942; 6,247,745; 6,679,967; 6,682,128; 6,752,450; 7,360,822; 7,377,577; 7,384,095; and 7,404,593. These absorbers are said to provide dynamic reaction force characteristics that produce a relatively “square wave” shape when observing their reaction force properties as a function of deflection.
[0007] U.S. Pat. No. 8,465,087 describes a formed energy absorber with an integrated anti-squeak/anti-rattle feature which includes a protrusion (“countermeasure”) that suppresses or dampens buzzes, squeaks or rattles at the end wall of an energy absorbing structure. Such structures typically lie between a Class-A surface (such as a bumper fascia, a headliner, or a door trim panel) and a rigid sheet metal structure in automotive applications. The absorber is typically installed with a 3-5 mm gap from one surface and is attached to another. However, in some instances it becomes necessary to reduce the gap to improve the reaction response time at the primary area of impact prior to secondary impacts as for example the head rolls into adjacent structures. When the absorber contacts the opposing surface, an undesirable buzz or rattle can be heard. This noise occurs because a flat hard plastic surface can tap or vibrate against the opposing structure. The '087 patent describes an anti-buzz, squeak or rattle feature that is formed integrally with energy absorbers during the thermoforming process. However, this feature has proven difficult to form consistently, requires relatively a narrow processing window, and generally lacks the flexibility necessary to fully mitigate the translation of one structure to another that creates a BSR condition.
[0008] Materials such as foam, felt, and flock are often added to absorbers which lack an integrated structure to remedy the issue. A fabric pad, flock material, foam padding, or some other kind of flexible material if added to one of the surfaces responsible for making the noise may lessen or eliminate the severity of the buzzing or tapping or eliminate the possibility of one surface translating into the other. However, this solution requires the purchase and assembly of one or more separate components, and that results in added complexity, cost, and mass.
SUMMARY OF INVENTION
[0009] One aspect of the present invention includes a base sheet and a plurality of energy absorbing units extending from the base sheet. Each energy absorbing unit includes a side wall that even when subjected to multiple hits deflects while absorbing energy and at least partially recovers after each hit. The energy absorbing unit includes an end wall. At least one of the base sheet and the end wall of at least one energy absorbing unit includes a number (X) of integrally-formed protruding countermeasures (“ears”) where 1<=X<1000. The protruding countermeasures have a lower standing strength than the energy absorbing units so that the protruding countermeasures dampen movement that may otherwise cause buzzes, squeaks and/or rattles (“BSR”) between the base sheet or end wall and an adjacent structure.
[0010] One aspect of the present disclosure includes a modified end wall structure that is superior to prior structures relative to ease of manufacture, cost, and function.
[0011] The improved energy absorber is created through a combination of designed geometry and tooling that creates a “domed” flexible member (“countermeasure”) extending from the end wall of an energy absorbing unit. The dome is designed and engineered in such a way that it interacts with the reaction surface through a touch or designed interference condition. In one embodiment, the frusto-conical side wall of the energy absorbing unit is maintained, but some or all of the end wall is convex or “domed”. In response to impact the side wall may buckle without reversion to its un-deflected state, but the countermeasure may revert to its initial condition soon after impact. This provides a rapid response to the desire to suppress buzzes, squeaks or rattles (“BSR”) after the hit.
[0012] In one embodiment, the domed countermeasure protrudes from the inner radius of an annular perimeter of the flat end wall. In another embodiment, the dome rises from the top of the side wall. In either embodiment there is tangential point contact between the energy absorbing structures and the adjacent structures that minimizes the surface area in contact with the reaction surface.
[0013] When the energy absorber is manufactured from a material of thickness (T), tooling is used to mold or coin the domed area to a thickness (t) substantially less than 0.5 (T), e.g., 0.1 (T). This makes the dome more flexible the rest of the structure and isolates or localizes preferred flexibility at and around the dome.
[0014] Imagine the dome is represented by part of a hemispherical shell with a pole positioned at its highest point and lines of longitude extending radially therefrom. In one embodiment, the dome may be lanced or cut parallel to the lines of longitude to create flexible “petals” that enable additional flexibility when compared to a non-lanced dome of the same material thickness. By changing the shape and position of the cuts in the dome, in combination with the “coined” thickness of the dome, additionally flexibility or strength may be imparted to meet BSR performance objectives.
[0015] In another aspect of the invention, an energy absorber includes a base sheet and a plurality of frusto-conical energy absorbing units extending from the base sheet. Each energy absorbing unit has a side wall that is oriented so that upon receiving the forces of impact (“incident forces”), the side wall offers some resistance, deflects and partially reverts (springs back) to an un-deflected pre-impact configuration while exerting reaction forces to oppose the incident forces. This phenomenon effectively cushions the blow by arresting the transmission of incident forces directed towards the mass or object to be protected (e.g., an anatomical member, a piece of sheet metal, an engine block, or the head of a passenger or player).
[0016] In another aspect of the present invention, a method includes the substantially simultaneous steps of forming an energy absorber with a base sheet and energy absorbing units extending from the base sheet with associated integral domed countermeasures of a weaker standing strength than the energy absorbing units.
[0017] In still another aspect of the present invention, an assembly method includes the steps of (1) providing a component or other mass to be protected, (2) forming substantially simultaneously an energy absorber including energy absorbing units and optionally at least one domed countermeasure in an end of one or more of the energy absorbing units, the countermeasure being configured to interface with the component or mass when placed adjacently, so that BSR from movement of the energy absorber relative to the adjacent component or mass is reduced or eliminated, and (3) assembling the energy absorber and the component or mass in adjacent positions.
[0018] In yet another aspect of the present invention, a thermoforming apparatus for making the energy absorber includes a heater for heating a flat sheet of a polymeric material, at least one thermoforming die for forming the flat sheet into a three-dimensional energy absorber that absorbs impacting forces non-destructively, the absorber having a base sheet and a plurality of energy absorbing units, and tooling for forming domed BSR countermeasures in at least one of the base sheet and the energy absorbing units.
[0019] These and other aspects, objects, and features of the present invention will be understood and appreciated by those skilled in the art upon studying the following specification, claims, and appended drawings.
BRIEF DESCRIPTION OF DRAWINGS
[0020] FIG. 1 is a cross-sectional view of opposing thermoforming dies for forming a sheet into an energy absorber with a plurality of energy absorbing units and domed countermeasures extending from recesses formed in the base sheet. At least some of the units have integral domed countermeasure for reducing buzzes, squeaks, and rattles (“BSR”) upon installation.
[0021] FIG. 2 is a cross-sectional view showing the thermoformed energy absorber of FIG. 1 .
[0022] FIG. 3 is a cross-sectional view showing the energy absorber installed between for example a roof structure of a passenger vehicle and a headliner or a helmet and the head of a wearer.
[0023] FIG. 4 is a cross section through one energy absorbing unit having a coined dome-shaped countermeasure extending from an end wall thereof.
[0024] FIGS. 5-6 are isometric views of a single energy absorbing unit.
[0025] FIGS. 7-8 are top views of the units depicted in FIGS. 5-6 .
[0026] FIG. 9 is a top view of an alternate embodiment.
[0027] FIG. 10 is a force-displacement graph that illustrates the response of energy absorbing units with and without a countermeasure.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
[0028] FIG. 1 illustrates a thermo forming process step in which an energy absorber 10 is shaped between a male (upper) die and a female (lower) die. If desired the dies could be inverted. FIG. 2 shows the product so formed. FIG. 3 depicts the energy absorber interposed between for example a vehicle roof 14 and a headliner 13 .
[0029] FIG. 4 is a cross section through one energy absorber (“EA”) 10 with a coined domed countermeasure 15 whose thickness (t) is substantially less than that of a base 16 or sidewalls 11 . A relatively thin dome 15 promotes flexibility in the interfacial region between the energy absorber 10 and a surface with which it is juxtaposed.
[0030] As shown in FIGS. 5-9 , if desired, the domed region 15 may be cut or lanced longitudinally and/or laterally to create slits 19 in a manner to be described to enhance flexibility and create pre-engineered zones of weakness.
[0031] In several embodiments of the invention the disclosed energy absorber has a base sheet 16 and a plurality of energy absorbing units 11 that preferably are reusable after exposure to multiple impacts. The energy absorbing units 11 extend from the base sheet 16 . Each energy absorbing unit 11 has an end wall 12 and a side wall 13 that in some cases revert at least partially towards an un-deflected configuration after impact. The sidewall 13 absorbs energy after being impacted. The end wall 12 of at least one energy absorbing unit 11 includes a number (X) of integrally-formed domed countermeasures 15 , where 1<=X<1000.
[0032] In some cases, the energy absorbing unit 11 reverts to an un-deflected or compression set configuration after a first impact. As used herein the term “compression set” means a configuration before impact in which an energy absorbing unit lies after being squeezed or compressed into position between for instance a Class A surface (e.g. a bumper fascia) and a rigid block or sheet of metal (e.g. a bumper frame). In other cases, the energy absorbing unit may revert to or towards the compression-set configuration after multiple impacts.
[0033] To absorb impact forces, the side wall 13 of an energy absorbing unit 11 bends in response to impact like the wall of a concertina or bellows and springs back to an un-deflected configuration in further response to impacting forces. In some cases opposing side walls 13 of an energy absorbing unit bend at least partially convexly after impact. In other cases, opposing side walls of the energy absorbing unit bend at least partially concavely after impact. Sometimes, opposing side walls of the energy absorbing unit 11 bend at least partially concavely and convexly after impact.
[0034] In one embodiment, the energy absorber 10 has an energy absorbing unit 11 with an end wall 12 that includes an annular ring around the perimeter of the end wall 12 of the domed countermeasure 15 . The domed end wall 12 is supported by an upper periphery of the side wall 13 and deflects inwardly, thereby absorbing a portion of the energy dissipated during impact.
[0035] Several alternative designs call for the countermeasure 15 to be formed in the base sheet 16 . In others, the countermeasure 15 is formed in the end wall 12 of an energy absorbing unit 11 .
[0036] Aided by these structures, the disclosed energy absorber can be re-used after single or multiple impacts. For example the hockey or football player or cyclist need not change his helmet after every blow. Most of the recovery occurs quite soon after impact. The remainder of the recovery occurs relatively late in the time period of recovery.
[0037] In a given end wall 12 there is a number (X) of countermeasures 15 , where 1<=X<1000. Some or all countermeasures 15 have slits 19 originating at an imaginary pole of a generally hemispherically shaped domed countermeasure. As used herein the term “hemispherical” is not limited in a geometrical sense to half of a sphere. It may describe or qualify a spheroid or oblate spheroid for example, like a squashed orange or pear or a section of a football.
[0038] As to the shape of the energy absorbing units 11 , it is useful to define an annular perimeter 17 ( FIGS. 7-9 ) of the end wall 12 inside the side wall 13 . The annular perimeter 17 has an inner radius (r) from which the domed countermeasure rises. Alternatively, the domed countermeasure may rise from a collar 21 extending from the end wall.
[0039] It is contemplated that the “soft” BSR countermeasure 15 can be formed integrally with the material of an energy absorbing unit at or near the location(s) of potential buzz, squeak, or rattle BSR noises.
[0040] Where deployed, the BSR countermeasure 15 has a relatively lower longitudinal/standing strength than the associated energy absorbing unit 11 . Though the sidewall of an energy absorbing unit may buckle and assume a permanent deformation following impact, the countermeasure flexes and reverts to its pre-impact configuration. Accordingly, it acts as a dampener, thus greatly reducing the likelihood of significant BSR noises in the final assembled product (such as an automotive vehicle or crash helmet for a motor cyclist or a helmet for the skier, hockey player or football player). Further, a significant assembly cost reduction and mass reduction can be realized with only a minimal or zero increase in the tooling and/or manufacturing cost because various wadding or muffling materials are no longer needed.
[0041] Various headliner constructions are exemplified in the drawings. However, persons skilled in this art will understand that the present disclosure is not limited to headliners, but instead can be applied to many other applications, including but not limited to other locations in a vehicle (e.g., doors, instrument panels, trim components for A, B and C pillars and roof supporting structures of vehicles, and other components), various types of protective headgear, and other protective gear that intercedes between an anatomical member (e.g., a knee, elbow, stomach) and an impacting object.
[0042] In one embodiment, an energy absorber 10 (illustrated in FIGS. 1-3 ) includes a matrix of hollow frusto-conical, distended frusto-conical (e.g. with an oval or elliptical footprint/lower perimeter/upper perimeter or cross section), cup-shaped (with a wall that is curvilinear—e.g., bowed, convex or concave when viewed from the side—or flat), domed, hemispherical or flat-sided pyramid-shaped) three-dimensional energy absorbing units with side walls 11 extending from a base sheet 16 . At least some of the energy absorbing units 11 have the BSR countermeasure 15 that extends from an end wall 12 of an energy absorbing unit 11 . In some cases the countermeasure 15 may effectively be flattened somewhat so that it resembles a domed end wall 16 that extends between the sidewalls 13 of an energy absorbing unit 11 ( FIGS. 5-6 ).
[0043] The energy absorbing units 11 can be arranged on the energy absorber 10 in any repeating or non-repeating, uniform or non-uniform pattern desired, such as an orthogonal or diagonal matrix of rows (parallel or converging) and columns (parallel or converging) that would partially or totally cover the mass to be protected, for example an area of a vehicle roof from the side-to-side and from the front-to-rear of a vehicle's passenger compartment.
[0044] Further, the energy absorbing units 11 can be similar to each other or can be varied, so as to have different or similar footprints, widths, heights, and/or cross-sectional shapes (parallel, inclined or perpendicular to the base sheet 16 ). The energy absorbing units 11 can have uniform or non-uniform spacing and/or different lateral relationships and/or be varied to accommodate the spatial constraints imposed by the environment of use, such as the vehicle roof and mating structures as needed for energy absorption in different areas of the assembly. For example, the energy absorber 10 can have different regions, some regions having energy absorbing units arranged or configured a first way, and other regions having energy absorbing units arranged or configured a second or different way. This is often the situation where energy absorbers are used in for example vehicle roof structures, as will be understood by persons skilled in this art. After thermoforming, the base sheet 16 may be flat or bent as desired.
[0045] As an example, the illustrated energy absorber 10 is thermoformed from a heated sheet 16 of a polyolefin polymeric material such as that available from Lyondell Bissell under the product name SV 152 . The sheet is heated to a temperature below its melting point and positioned between by opposing forming dies 17 , 18 (see FIG. 1 ), and then cooled to form a three-dimensional energy absorber (see FIG. 2 ). Opposing forming dies 17 , 18 are illustrated, but it is contemplated that the present inventive concepts can be made using other forming processes, such as a thermoforming process using only a single sided die (e.g. by vacuum thermoforming). Optionally the absorber is made by softening a sheet of starting material and positioning it across a tool with which it is made to conform under a vacuum. It will be appreciated that the present inventive concepts can be made by other forming processes, such as injection molding, compression molding, and the like.
[0046] Once formed, the illustrated energy absorber 10 is adapted to fit between and generally at least partially bridge a gap between for instance a vehicle headliner 13 and its roof 14 (see FIG. 3 ). In the exemplary application depicted, the energy absorbing units 11 and the base sheet 12 are generally configured to occupy at least some space between the headliner 13 and roof 14 . The outer ends 16 (also called “end walls” or “base” herein) of the energy absorbing units 11 and the base sheet 12 generally match the contoured mating surfaces on the headliner 13 and roof 14 .
[0047] The illustrated energy absorber 10 has differently shaped energy absorbing units 11 that are configured to meet spatial or aesthetic requirements and cover protruding bolts plus other fittings while optimizing the safe absorption of energy and distribution of impact loads in order to reduce at least in vehicular applications passenger head injury (such as during a vehicle crash or roll-over accident) or in other non-vehicular applications (such as head- or limb-protecting gear).
[0048] As noted above, the (BSR) countermeasure 15 (also called an “ear” or “soft structure” herein) is integrally formed into its end wall 12 , as illustrated. An energy absorber 10 may have energy absorbing units 11 with a collective number (X) of ears 15 that are associated with the energy absorber 10 , where 1<=X<1000.
[0049] The countermeasures 15 have a lower standing strength than the energy absorbing units 11 . Their “softness” reduces the potential for BSR noises caused by repeated noise-generating vibration and/or cyclical movement of the energy absorber 10 against adjacent rigid surfaces on for example the headliner 13 and roof 14 .
[0050] In end wall 16 , the illustrated BSR countermeasure 15 ( FIG. 1 ) preferably is formed by a rounded male protrusion 20 that extends from the top die 17 into a mating recess in the lower die 18 . The protrusions 20 include at least part of a hemispherical dome. As a consequence the sheet material assumes a shape after cooling that resembles a dome-shaped thin-walled hollow BSR countermeasure 15 . It will be appreciated that the dome may be described by an angle of latitude (in terrestrial terms) less than 90 degrees, i.e., the dome need not be a geometrically perfect hemisphere.
[0051] In some cases the base sheet 16 (or roof, depending on orientation) of an energy absorbing unit 11 itself may be domed to form a countermeasure 15 so as effectively to interface with a neighboring structure, thereby reducing an area of contact therebetween and reducing or eliminating BSR.
[0052] The illustrated BSR countermeasures 15 are sufficient in length and strength to maintain their generally hemispherical shape after the starting sheet material is cooled (see FIG. 2 ). In particular, the height of the BSR countermeasures 15 in combination with energy absorbing units 11 is greater than any expected gap between the headliner 13 and the roof 14 (in vehicular applications), such that the BSR countermeasure 15 contacts the headliner 13 (or roof 14 ) and is compressed during assembly into the vehicle.
[0053] The domed BSR countermeasure 11 also compensates for variations in the gap size due to part tolerance variation, assembly stack-up variations, and other process and part variables that may lead to inconsistent gaps. This results in the BSR countermeasures 15 acting to dampen any cyclical or vibratory movement of the energy absorber 10 , which in turn eliminates most BSR noises.
[0054] As an example, it is contemplated that the BSR countermeasures 15 can be about ⅛ to ½ inch in height (or more typically about ¼ to ⅜ inches), and at their base about 1/32 to ¼ inch in diameter (or more preferably about 1/16 to ⅛ inch in diameter).
[0055] As mentioned earlier, the countermeasure is preferably sufficiently flexible so that it deflects at relatively low loads in a relatively elastic manner. The term “relatively low load” as used herein is defined as less than 2 lb.f at each point of contact. By comparison, the energy absorbing unit itself typically collapses at loads in excess of 10 lb.f (see, e.g. FIG. 10 ). In this way, flexibility is substantially localized at the countermeasure on the end wall.
[0056] One manufacturing technique involves coining Though other methods may be suitable, coining is done by providing a rigid lower member (typically metal) and an upper coining member. A representative configuration is a matched metal set and a material which is more rigid than the molten plastic (like a rigid silicone rubber). This prompts displacement of material away from the domed countermeasure, preferentially thinning the dome in the contacted area. Other things being equal, the thinner the material, the less resistance is required to displace the dome. Furthermore, by relieving the dome with cross cuts as described above, the resistance required to displace the dome is further reduced.
[0057] It is to be understood that variations and modifications can be made on the aforementioned structure without departing from the concepts of the present invention, and further it is to be understood that such concepts are intended to be covered by the following claims unless these claims by their language expressly state otherwise. | An energy absorber includes a base sheet and a plurality of energy absorbing units with domed countermeasures extending from the base sheet. The countermeasures have slits in a domed portion thereof. The side walls of the energy absorbing units protect an adjacent object by cushioning the blow following repeated impacts in both vehicular and non-vehicular (e.g. helmets) environments. Preferably the side walls are oriented to buckle or bend after absorbing energy when impacted. The countermeasures primarily deaden any associated buzzes, squeaks or rattles. The integrally-formed countermeasures have a lower standing strength than the energy absorbing units. Methods related to the above are also described. | 5 |
CROSS-REFERENCE TO RELATED APPLICATIONS
This application is related to application Ser. No. 08/272,161 of David Andrew Barclay Miller, entitled "Current Mirror for Depletion-Mode Field Effect Transistors with Level Shifting", filed on Jul. 7, 1994, now abandoned, and application Ser. No. 08/273,042 of David Andrew Barclay Miller, entitled "Linear Optical Amplifier", filed on Jul. 8, 1994.
TECHNICAL FIELD
This invention relates generally to optical converters, and more particularly, to optical converters for converting an optical bipolar signal to an optical unipolar signal.
BACKGROUND OF THE INVENTION
Optical information processing entails the ability to perform analog operations such as correlation, convolution, and differentiation with optical beams. These operations provide results that are both positive and negative in value. Since the intensity of an optical beam is always positive, positive and negative values may be represented as the difference in power between two optical beams. As a result, a signal initially in unipolar form (i.e., a signal represented by the always positive-valued intensity of a single optical beam) must be converted to a signal in bipolar form (i.e., a signal that has both positive and negative values). After processing the optical signal in bipolar form, it is often desirable to convert the result back into unipolar form, particularly when the result is intended to form an image. An output that forms an image is desirable because often it may be readily understood from a visual inspection.
An apparatus for converting an optical bipolar signal to a unipolar signal is described by Miller in IEEE J. Quantum Electron., Vol. 29, Number 2, February 1993, pages 678-698, specifically on page 681 and in FIG. 3 of that article. One limitation of this apparatus is that an optical bias beam must be added to one of the rails of the bipolar input signal. Accordingly, this known apparatus requires a relatively complex optical system.
SUMMARY OF THE INVENTION
In accordance with this invention, reduced optical complexity is achieved by providing an apparatus for converting a bipolar optical signal to a unipolar optical signal includes first and second photodetectors electrically coupled in series for receiving the bipolar optical signal. An electro-absorption modulator such as a self-linearized modulator, for example, is electrically coupled to the photodetectors. The modulator serves to transmit therethrough a portion of the power of an optical beam in an amount proportional to the power of the bipolar optical signal to form a transmitted beam. A constant current source is provided for supplying a current that shifts the power of the optical beam transmitted through the modulator by a predetermined amount, thus forming the desired unipolar optical signal.
In one embodiment of the invention, the constant current source is a transistor. The transistor is configured so that a voltage applied thereto determines the value of the current employed to shift the power of the optical beam. Alternatively, the constant current source may be a current mirror, in which case the value of the current is determined by an input current supplied to the input of the current mirror.
In one particular embodiment of the invention, the photodetectors are photodiodes that supply a first current to a node in response to the bipolar optical signal. The electro-absorption modulator generates a second current in response to the optical beam transmitted therethrough and supplies this second current to the node. The transistor or current mirror supplies a predetermined current to this same node.
In an alternative embodiment of the invention, a plurality of the optical bipolar to unipolar converters of the present invention are provided to form a converter array for converting a plurality of bipolar signals to a plurality of unipolar signals. A single control circuit such as the input stage of a current mirror, for example, may be used to supply the same control input (such as a control voltage) to each of the individual converters in the array so that the shift in power of the optical beam transmitted through the modulator is substantially identical for all the converters.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 shows one embodiment of an apparatus for converting a bipolar optical signal to a unipolar optical signal in accordance with the present invention.
FIG. 2 shows one embodiment of a converter array that includes a plurality of the converters shown in FIG. 1.
FIG. 3 shows an alternative embodiment of the converter array shown in FIG. 2 in which the control voltage source is replaced with a control transistor.
FIGS. 4-5 show examples of known current mirror circuits.
DETAILED DESCRIPTION
FIG. 1 illustrates one embodiment of the optical bipolar to unipolar converter 20 of the present invention. A bipolar optical signal comprises two unipolar signals and the power of the bipolar optical signal may be represented as the difference in power between two optical signals each defining one rail of the bipolar signal. In FIG. 1 the bipolar input signal is represented by optical beams P inA and P inB and thus the value of the bipolar signal is equal to the power difference (P inA -P inB ). The converter 20 includes two photodetectors 2 and 4 coupled in series. In the embodiment of the invention shown in FIG. 1 the photodetectors 2 and 4 are reversed biased photodiodes. A node 10 located between the photodiodes 2 and 4 is connected to an electro-absorption modulator 6 and the drain of an output transistor 8. The electro-absorption modulator 6 generates a photocurrent that is proportional to the power of an optical beam incident thereon. The source of the output transistor 8 is coupled to ground and the gate of the transistor 8 is coupled to a constant voltage source 12. While the embodiment of the invention shown in FIG. 1 incorporates a field-effect transistor (FET), one of ordinary skill in the art will recognize that bipolar transistors may be employed instead. However, for the sake of clarity the following discussion will describe the invention as employing a FET.
In operation, the optical input beams P inA and P inB are incident upon respective ones of the photodiodes 2 and 4. Because the photodiodes are reverse-biased, they each generate a photocurrent. As is well-known, the current generated by a typical reverse-biased photodiode is linearly proportional to the input optical power. For many photodiodes the proportionality between the current and input power is such that for every incident Photon one electron of current is generated, i.e., ##EQU1## where I pc is the current generated by the photodiode, ω is the incident photon energy and e is the electronic charge. For the sake of clarity the following discussion will assume that the converter of the present invention employs photodiodes possessing this characteristic. However, one of ordinary skill in the art will recognize that the present invention may employ instead photodiodes having a different relationship between the incident power and the generated photocurrent. Nevertheless, regardless of the particular power-current relationship of the photodiodes employed, the net photocurrent I diff flowing out of the node 10 is proportional to the power difference between the optical beams P inA and P inB incident upon the photodiodes 2 and 4, respectively. Specifically, assuming that one electron is generated per incident photon,
I.sub.diff =e/ ω(P.sub.inA -P.sub.inB) (2)
The output FET 8 is biased so that the current I out flowing through its drain is a function of the gate-source voltage and is substantially independent of the source-drain voltage. It is well-known that such ideal behavior may be obtained over a given operating range that varies from FET to FET. Accordingly, if the gate-source voltage of the output FET 8 is maintained at a constant value as indicated by the arrangement in FIG. 1, I mod will depend only on the currents I diff and I out , where I mod is the current generated by the electro-absorption modulator 6. More particularly, by conservation of current
I.sub.mod =I.sub.out -I.sub.diff (3)
It is well-known that certain electro-absorption modulators generate one electron of photocurrent for every photon absorbed from the incident optical power beam. For such a modulator, the photocurrent I mod is proportional to the optical power absorbed in the modulator 6. This mode of operation is known as the "self-linearized modulator" mode and a modulator operating in this mode is referred to as a self-linearized modulator. An example of a self-linearized modulator that may be employed in the present invention is disclosed in the reference by D. A. B. Miller et al., IEEE Journal of Quantum Electronics, Vol. QE-21, Number 9, September 1985, pages 1462-1476. While the electro-absorption modulators shown in FIG. 1 transmits light therethrough, other modulators may be employed in which the modulator contains a reflective surface for reflecting light back through the modulator. Moreover, other electro-absorption modulator having a self-linearized mode of operation may be employed such as, for example, a bulk semiconductor diode that utilizes the Franz-Keldysh effect. Additionally, while the present invention will be described below as employing a self-linearized modulator, one of ordinary skill in the art will recognize that any electro-absorption modulator may be used for which the generated photocurrent is proportional to the absorbed optical power.
As seen in FIG. 1, the modulator 6 is powered by an optical supply beam P s that generates the photocurrent I mod . The modulator 6 emits an optical output beam P out that is smaller than the optical supply beam P s due to the photons absorbed to generate the photocurrent I mod . If the modulator 6 operates in the self-linearized mode, the output beam P out is smaller than the supply beam P s by an amount corresponding to one photon for every electron of current generated by the modulator, i.e.,
P.sub.out =P.sub.s -( ω/e)I.sub.mod (4)
Eliminating I mod by substituting equation 3 into equation 4 yields: ##EQU2## Finally, substituting equation 2 into equation 5 provides a relationship between the output beam P out and the difference between input signals P inA and P inB : ##EQU3##
Accordingly, the power of the output beam P out is proportional to the input power difference (P inA -P inB ) of the bipolar input signal, offset by an amount linearly dependent on the current I out flowing through the drain of the output FET 8. It should be noted that if the term I out were not present in equation (6) the converter 20 could not convert an input signal for which PinA was greater than P inB because such a situation would require that the output beam power P out be greater than the supply beam P S , which is not possible because the modulator 6 is not a source of optical energy. In fact, if the term in equation 6 containing I out were not present the modulator would not operate in its self-linearized mode whenever P inA was greater than P inB .
FIG. 2 shows a converter array that includes two converters 20 and 30 in accordance with the present invention. While the converter array shown in FIG. 2 includes only two converters, one of ordinary skill in the art will recognize that the array may include as many converters as desired for a particular application. As indicated in FIG. 2, the converters all may be powered by the same control voltage source 12 supplied to the gate of each transistor. One advantage achieved by employing a single control voltage is that if the output transistors employed in each converter are substantially the same, then each converter will provide the same linear offset to the bipolar signal when it is converted to a unipolar signal since the values of I out for all the output transistors will be the same (see equation 6).
In an alternative embodiment of the invention the control voltage source 12 may be replaced by a control transistor 14 such as shown in FIG. 3, which is powered by an input current. The gate of the control transistor 14 is coupled to the gate of each output transistor of each individual converter employed in the array. The control transistor 14 is arranged so that it forms a current mirror with each of the output transistors. Current mirrors are well-known and serve to reproduce a current from one location to one or more other locations.
FIGS. 4-5 show examples of current mirrors that employ bipolar transistors and enhancement-mode FETS, respectively. Examples of various current mirrors are disclosed in U.S. Pat. Nos. 5,134,358, 5,166,553 and 4,896,121. Another current mirror that may be employed in the present invention is disclosed in the co-pending application entitled "Current Mirror in Depletion-Mode Field Effect Transistor with Level Shifting," by D. A. B. Miller, filed in the U.S. Patent and Trademark Office on Jul. 7, 1994, which is hereby incorporated by reference. Regardless of the type of transistor employed, each current mirror shown in FIGS. 4-5 has an input transistor T in and an output transistor T out whose gates (or bases in the case of the bipolar transistors shown in FIG. 4) are coupled together. The sources (or emitters) of the input and output transistors T in and T out are also coupled together and in the exemplary current mirrors shown in the figures the sources (or emitters) are connected to ground. The drain (or collector) of the input transistor T in is coupled to the gate (or base) of both the input and output transistors T in and T out . In operation, a current I in supplied to the drain (or collector) of the input transistor T in will be reproduced at the drain (or collector) of the output transistor T out . If the input and output transistors are not identical, the input current I in will be proportional to the output current I out with non-unity gain. In FIG. 3, the control transistor 14 forms the input transistor of the current mirrors and the output transistors of each converter in the array form the corresponding output transistors of the respective current mirrors.
The control transistor 14 allows the output current I out of each converter to be controlled by a single input current I in supplied to the converter array. As a result, the value of the input current determines the value of the offset applied to the bipolar signal when it is converted to a unipolar signal. This arrangement may be advantageous over the arrangement in FIG. 2, in which the control voltage determines the value of the offset, because the offset is linearly proportional to the input current supplied to the control transistor 14. In contrast, if a control voltage is used, the offset generally will not be linearly proportional to the control voltage. This nonlinear relationship occurs because the source-gate (or emitter-base) voltage of a transistor is not in general linearly proportional to the source-drain (or emitter-collector) current. Another advantage achieved by using an input current to control the converter array rather than a control voltage is that the characteristics of a current mirror are relatively insensitive to temperature changes whereas a single transistor is significantly temperature dependent. In the case of bipolar transistors particularly, the relationship between the emitter-collector current and the emitter-base voltage is very temperature dependent.
The converter and converter array of the present invention may be fabricated from discrete components or as a single component monolithically integrated on a semiconductor wafer. Monolithic integration employing enhancement-mode FETs may be achieved by using conventional GaAs fabrication technology such as described in S. M. Sze, Physics of Semiconductor Devices, Wiley, New York, 2nd ed. 1981, p. 322. Monolithic integration employing depletion-mode FETs, quantum well modulators, and photodetectors may be achieved, for example, by a method disclosed in L. A. D'Araro et al., IEEE Journal of Quantum Electronics, Vol. 29, Number 2, February 1993, pages 670-677. | An apparatus for converting a bipolar optical signal to a unipolar optical signal includes first and second photodetectors electrically coupled in series for receiving the bipolar optical signal. An electro-absorption modulator such as a self-linearized modulator, for example, is electrically coupled to the photodetectors. The modulator serves to transmit therethrough a portion of the power of an optical beam in an amount proportional to the power of the bipolar optical signal to form a transmitted beam. A constant current source is provided for supplying a current that shifts the power of the optical beam transmitted through the modulator by a predetermined amount, thus forming the desired unipolar optical signal. | 7 |
This application is a continuation of Ser. No. 10/293,056, filed Nov. 12, 2002 now U.S. Pat. No. 6,762,264, which is a continuation of Ser. No. 09/598,416, filed Jun. 20, 2000, now abandoned.
BACKGROUND OF THE INVENTION
The present invention generally relates to silicone hydrogel compositions useful as biomedical devices, such as contact lenses and intraocular lenses.
Polymeric silicone materials have been used in a variety of biomedical applications, including, for example, in contact lenses and intraocular lenses. Such materials can generally be subdivided into hydrogels and non-hydrogels. Silicone hydrogels constitute crosslinked polymeric systems that can absorb and retain water in an equilibrium state and generally have a water content greater than about 5 weight percent and more commonly between about 10 to about 80 weight percent. Such materials are usually prepared by polymerizing a mixture containing at least one silicone-containing monomer and at least one hydrophilic monomer. Either the silicone-containing monomer or the hydrophilic monomer may function as a crosslinking agent (a crosslinker being defined as a monomer having multiple polymerizable functionalities) or a separate crosslinker may be employed.
Silicone hydrogels combine the beneficial properties of hydrogels with those of silicone-containing polymers (Kunzler and McGee, “Contact Lens Materials”, Chemistry & Industry , pp. 651-655, 21 August 1995). Silicone hydrogels have been used to produce a contact lens that combines the high oxygen permeability of polydimethylsiloxane (PDMS) materials with the comfort, wetting and deposit resistance of conventional non-ionic hydrogels.
Monomers that have been found to be particularly useful for preparing silicone-containing contact lenses are described in U.S. Pat. Nos. 4,136,250; 4,153,641; 4,189,546; 4,208,506; 4,217,038; 4,277,595; 4,327,203; 4,355,147; 4,740,533; 4,780,515; 5,034,461; 5,070,215; 5,310,779; 5,346,976; 5,374,662; 5,358,995; 5,387,632; 5,420,324; and 5,496,871.
U.S. Pat. No. 4,153,641 (Deichert et al) discloses contact lenses made from poly(organosiloxane) monomers which are α,ω terminally bonded through a divalent hydrocarbon group to a polymerized activated unsaturated group. Various hydrophobic silicone-containing prepolymers such as 1,3-bis(methacryloxyalkyl)-polysiloxanes were copolymerized with known hydrophilic monomers such as 2-hydroxyethyl methacrylate (HEMA). These materials were used to produce lenses which had a low water content and a high modulus (greater than 300 g/mm 2 ).
U.S. Pat. No. 5,358,995 (Lai et al) describes a silicone hydrogel which is comprised of an acrylic ester-capped polysiloxane prepolymer, polymerized with a bulky polysiloxanyalkyl (meth)acrylate monomer, and at least one hydrophilic monomer. The acrylic ester-capped polysiloxane prepolymer, commonly known as M 2 D x consists of two acrylic ester end groups and “x” number of repeating dimethylsiloxane units. The preferred bulky polysiloxanyakyl (meth)acrylate monomers are TRIS-type (methacryloxypropyl tris(trimethylsiloxy)silane) with the hydrophilic monomers being either acrylic- or vinyl-containing. While the properties of these lenses are acceptable, the modulus of these lenses can be high, which may result in damage to the epithelial layer and poor comfort.
Designing silicone based hydrogels utilizing M 2 D x as the base prepolymer has mainly involved copolymerizing the prepolymer with hydrophilic monomers, such as dimethylacrylamide and N-vinylpyrrolidone. Silicone is hydrophobic and has poor compatibility with hydrophilic monomers, especially when the M 2 D x prepolymer is of high molecular weight. Poor compatibility results in phase separated, opaque materials. This can be particularly problematic when preparing hydrogels to be used as optically clear contact lenses.
Reducing the molecular weight of the M 2 D x prepolymer can improve the incompatibility. Unfortunately, low molecular weight M 2 D x prepolymers typically result in hydrogels of high modulus. This is a direct result of the higher crosslink density of these low molecular weight M 2 D x based hydrogels.
In designing a low modulus silicone hydrogel based on low molecular weight M 2 D x prepolymers, one approach can be to use high concentrations of hydrophilic monomers. The lower modulus for these materials is a result of the higher water content and lower cross-link density. The major drawback of this approach is that the higher water content materials possess lower levels of oxygen permeability, due to the lower concentration of silicone in these materials. The low levels of oxygen permeability are not suitable for continuous wear contact lens application.
Another approach in the development of low modulus silicone hydrogels based on low molecular weight M 2 D x prepolymers is through the incorporation of the monomer methacryloxypropyl tris(trimethylsiloxy)silane (“TRIS”). Higher concentrations of TRIS results in hydrogels of lower modulus, but lenses made with high TRIS levels overall tend not to perform well in clinical studies.
The development of low modulus hydrogels based on low molecular weight M 2 D x prepolymers may be accomplished through the addition of silicone macromonomers, such as those taught by Y. Kawakami in Polymer Journal , v. 14, p. 913, 1982. High levels of silicone macromonomer may reduce the modulus by lowering the cross-link density of the resultant hydrogel without a significant reduction in oxygen permeability. The major disadvantage of this route is that the methacrylate based silicone macromonomers are very difficult to synthesize. The synthesis of siloxane macromonomers requires several steps.
SUMMARY OF THE INVENTION
There remains a need for a contact lens material having the high oxygen permeablity of a polysiloxane-containing prepolymer, yet have a modulus low enough to be used as a contact lens. The approach taken in this invention alters the silicone-containing monomer to affect the polymer properties. By lowering the methacrylate functionality of M 2 D x , the cross-linking density is reduced. This can be done by removing a percentage of the methacrylate groups on the end of the prepolymer.
These improved polymer silicone hydrogel compositions are formed from the polymerization product of a monomer mixture comprising a silicone prepolymer having the general formula:
wherein;
A is an activated unsaturated radical; A′ is either an activated unsaturated radical or an alkyl group; R 1 -R 10 are independently an alkyl, fluoroalkyl, alcohol, ether, or fluoroether group having 1-10 carbons, or an aromatic group having 6-18 carbons; m, n, and p are independently 0 to 200, m+n+p being from about 15 to 200; a is 1 to 10; and b is 0 to 10,
wherein the silicone prepolymer is prepared by the reaction of dimethacrylate disiloxane (M 2 ) and cyclic siloxane (D) in the presence of an catalyst, the improvement comprising adding at least one disiloxane (T 2 ) having the fomula:
wherein R 11 -R 16 are independently an alkyl group having 1-5 carbons, to the reaction mixture used to form the silicone prepolymer.
In particular, this invention is directed to preparing a M 2 D x based prepolymer that is endcapped with trimethylsilyl (TMS) as shown in formula II:
wherein m+n+p is 15 to 200.
Note that prepolymers of formula II are a species of formula I wherein b is zero and R 9 ,R 10 and A′ are methyl groups.
Applicants have found that the above preparation of making the prepolymer is especially effective in improving the flexibility of polymer silicone materials and hence lowering the modulus of silicone hydrogel copolymers, in contrast to previous siloxane compounds which were methacrylate endcapped and not endcapped with trimethyl silyl. The synthesis of the M 2 D x , TMS-endcapped prepolymer is easy, requiring fewer steps and components than previous methods.
The hydrogel material is especially useful in biomedical devices such as soft contact lenses, intraocular lenses, heart valves and other prostheses.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
This invention describes a novel approach to the design of low modulus silicone hydrogels based on M 2 D x prepolymers. The M 2 D x prepolymers of this invention contain a “built-in” modulus reducing functionality: a trimethylsilyl (TMS) endcap. Increasing the concentration of the TMS endcap (or reducing the concentration of the methacrylate cap) results in lower modulus, transparent silicone hydrogels without a reduction in water transport or oxygen permeability.
These improved polymer silicone hydrogel compositions are formed from the polymerization product of a monomer mixture comprising a silicone prepolymer having the general formula:
wherein;
A is an activated unsaturated radical; A′ is either an activated unsaturated radical or an alkyl group; R 1 -R 10 are independently an alkyl, fluoroalkyl, alcohol, ether, or fluoroether group having 1-10 carbons, or an aromatic group having 6-18 carbons; m, n, and p are independently 0 to 200, m+n+p being from about 15 to 200; a is 1 to 10; and b is 0 to 10,
wherein the silicone prepolymer is prepared by the reaction of dimethacrylate disiloxane (M 2 ) and cyclic siloxane (D) in the presence of an catalyst, the improvement comprising adding at least one disiloxane (T 2 ) having the formula:
wherein R 11 -R 16 are independently an alkyl group having 1-5 carbons, to the reaction mixture used to form the silicone prepolymer.
With respect to A, A′ of formula I, the term “activated is used to describe unsaturated groups which include at least one substituent which facilitates free radical polymerization, preferably an ethylenically unsaturated radical. This includes esters or amides of acrylic or methacrylic acid represented by the general formula:
wherein X is preferably hydrogen or methyl but may include other groups, e.g., cyano, and Y represents —O—, —S—, or —NH—, but is preferably —O—. Examples of other suitable activated unsaturated groups include vinyl carbonates, vinyl carbamates, fumarates, fumaramides, maleates, acrylonitryl, vinyl ether and styrl.
Dimethacrylate disiloxane (M 2 ) is represented by the general formula:
Cyclic siloxane (D) may be any cyclical compound and substitute analogs containing at least 3 silicone-oxygen groups. Examples include 1,1,3,3-tetramethyl-1,3-disila-2-oxacyclopentane, hexamethylcyclotrisiloxane and octamethylcyclotetrasiloxane or mixtures thereof. The preferred D is octamethylcyclotetrasiloxane (D 4 ).
The preferred T 2 is hexamethyl disiloxane and is represented by the following formula:
The catalyst used must be able to cleave Si—O bonds. Those agents include acid clays, hydrogen fluoride acid, HCl—FeC13 (hydrochloric acid-iron(III) chloride complex), concentrated sulfuric acid, and trifluoromethane sulfonic (triflic) acid. The preferred acids are concentrated sulfuric acid and triflic acid.
The present invention contemplates polymerizing polysiloxane prepolymer mixture with bulky polysiloxanylalkyl (meth)acrylate monomers and at least one hydrophilic monomer. The polysiloxane prepolymers utilized in this invention are those having m+n+p equal to about 15 to 200 repeating dimethylsiloxane units. Preferred polysiloxane prepolymers are those having about 25 to about 50 repeating dimethylsiloxane units. More preferred polysiloxane prepolymers are those in which there are 25 repeating dimethylsiloxane units.
It is preferred that the total concentration of the prepolymer is endcapped with 1 to 70 mole % trialkylsilyl, preferably 25 to 50 mole % trialkylsilyl and more preferably 40 to 50 mole % trialkylsilyl. Thus, “prepolymer” as used herein denotes a compound having formulae (I) and (II):
These M 2 D x , TMS-endcapped prepolymers are extremely easy to synthesize. The synthesis consists of an acid catalyzed, ring opening polymerization conducted in a single vessel. The cyclic siloxanes (D), endcapping agents (M 2 ) and disiloxanes (T 2 ) are simply added to a reaction vessel together with a suitable catalyst and stirred at room temperature for a period of time.
Silicone hydrogels of this invention are crosslinked polymeric systems that can absorb and retain water in an equilibrium state. These polymeric systems are based on at least one silicone-containing monomer and at least one hydrophilic monomer. Preferably, the silicone hydrogels of this invention are formed by polymerizing a monomer which comprises the prepolymer mixture of this invention, a second unsaturated silicone-containing monomer and at least one hydrophilic monomer. More preferably, the second unsaturated silicone-containing monomer may include monofunctional silicone-containing monomers. Most preferably, the monofunctional silicone-containing monomer is at least one member of the group consisting of bulky polysiloxanylalkyl (meth)acrylic monomers are represented by Formula (III):
wherein: X denotes —COO—, —CONR 4 —, —OCOO—, or —OCONR 4 — where each where R 4 is independently H or lower alkyl; R 3 denotes hydrogen or methyl; h is 1 to 10; and each R 2 independently denotes a lower alkyl radical, a phenyl radical or a radical of the formula
—Si(R 5 ) 3
wherein each R 5 is independently a lower alkyl radical or a phenyl radical.
Such bulky monomers specifically include methacryloxypropyl tris(trimethylsiloxy)silane (“TRIS”), pentamethyldisiloxanyl methylmethacrylate, tris(trimethylsiloxy)methacryloxy propylsilane, phenyltetramethyl-disloxanylethyl acrylate, methyldi(trimethylsiloxy)methacryloxymethyl silane, 3-[tris(trimethylsiloxy)silyl]propyl vinyl carbamate, 3[tris(trimethylsiloxy)silyl]propyl allyl carbamate, and 3-[tris(trimethylsiloxy)silyl]propyl vinyl carbonate.
Preferred hydrophilic monomers may be either acrylic- or vinyl-contain. The term “vinyl-type” or vinyl-containing” monomers refers to monomers containing the vinyl grouping (CH 2 ═CHR) and are generally reactive. Such hydrophilic vinyl-containing monomers are known to polymerize relatively easily. Acrylic-containing monomers are those monomers containing the acrylic group (CH 2 ═CRCOX) wherein R═H or CH, and X═O or NH, which are also known to polymerize readily.
Examples of suitable hydrophilic monomers include: unsaturated carboxylic acids, such as methacrylic and acrylic acids; acrylic substituted alcohols, such as 2-hydroxyethyl methacrylate and 2-hydroxyethylacrylate; vinyl lactams, such as N-vinyl pyrrolidone; and acrylamides, such as methacrylamide with N,N-dimethyl acrylamide (DMA) being the most preferred. Other monomers include glycerol methacrylate and 2-hydroxyethyl methacrylamide.
Silicone hydrogels of this invention are typically formed by polymerizing a monomer mixture comprising: about 10 to about 90 weight percent of a prepolymer, preferably 20 to 70 weight percent of a prepolymer, more preferably 20 to 50 weight percent, comprised of monomers represented by formula I and formula II wherein the total concentration of the prepolymer is endcapped with about 1 to about 70 mole % trimethylsilyl, preferably about 25 to about 50 mole % trimethylsilyl, more preferably about 40 to about 50 mole % trimethylsilyl; about 10 to about 50 weight percent of a monofunctional ethylenically unsaturated silicone-containing monomer, more preferably about 20 to about 50 weight percent of a monofunctional ethylenically unsaturated silicone-containing monomer, more preferably about 20 to about 40 weight percent of a monofunctional ethylenically unsaturated silicone-containing monomer, and about 5 to about 70 weight percent of a hydrophilic monomer, preferably 10 to about 50 weight percent of a hydrophilic monomer, more preferably about 20 to about 40 weight percent of a hydrophilic monomer. An example of a silicone hydrogel made from this invention may have about 20 parts of a prepolymer that is endcapped with 50 mole % TMS, about 35 parts of a hydrophilic monomer, about 25 parts of an monofunctional ethylenically unsaturated silicone-containing monomer. Other components, such as a diluent may be added and are discussed below.
The monomer mixture of the present invention may include additional constituents such as UV-absorbing agents, internal wetting agents, hydrophilic monomeric units, toughening agents, or colorants such as those known in the contact lens art.
Conventional curing methods in polymerizing ethylenically unsaturated compounds such as UV polymerization, thermal polymerization, or combinations thereof, can be used to cast these monomer mixtures. Representative free radical thermal polymerization initiators can be organic peroxides and are usually present in the concentration of about 0.01 to 1 percent by weight of the total monomer mixture. Representative UV initiators are known in the field such as, benzoin methyl ether, benzoin ethyl ether, 1164, 2273, 1116, 2959, 3331 (EM Industries) and Irgacure 651 and 184 (Ciba-Geigy). In the preferred embodiment, Darocur 1173 is the UV initiator.
Polymerization of the prepolymer of this invention with other copolymers is generally performed in the presence of a diluent. The diluent is generally removed after polymerization and replaced with water in extraction and hydration protocols well known to those skilled in the art. Representative diluents are diols, alcohols, alcohol/water mixtures, ethyleneglycol, glycerine, liquid polyethyleneglycol, low molecular weight linear polyhydroxyethylmethacrylates, glycol esters of lactic acid, formamides, ketones, dialkylsulfoxides, butyl carbitol, and the like. Preferred diluents include hexanol and nonanol.
It is also possible to perform the polymerization in the absence of diluent to produce a xerogel. These xerogels may then be hydrated to form hydrogels as is well known in the art.
The monomer mixture may include a tinting agent, defined as an agent that, when incorporated in the final lens, imparts some degree of color to the lens. Conventional tinting agents are known in the art, including non-polymerizable agents, or polymerizable agents that include an activated unsaturated group that is reactive with the lens-forming monomers. One preferred example of this latter class is the compound 1,4-bis(4-(2-methacryloxyethyl)phenylamino)anthraquinone, a blue visibility-tinting agent disclosed in U.S. Pat. No. 4,997,897 (Melpolder).
The monomer mixture may also include a UV-absorbing agent, defined as an agent that reduces light in the general region of 200 to 400 nm. Representative polymerizable UV absorbing materials for contact lens applications are described in U.S. Pat. No. 4,304,895 (Loshaek), U.S. Pat. No. 4,528,311 (Beard et al), U.S. Pat. No. 4,716,234 (Dunks et al), U.S. Pat. No. 4,719,248 (Bambury et al), U.S. Pat. No. 3,159,646 (Milionis et al) and U.S. Pat. No. 3,761,272 (Manneus et al). Examples of UV-absorbing compounds include the benzotriazoles and benzophenones.
Various techniques for molding hydrogel polymer mixtures into contact lenses are known in the art, including spin casting and static cast molding. Spin casting processes are disclosed in U.S. Pat. Nos. 3,408,429 and 3,496,254. Static cast molding involves charging a quantity of polymerizable monomeric mixture to a mold assembly, and curing the monomeric mixture while retained in the mold assembly to form a lens, for example, by free radical polymerization of the monomeric mixture. Examples of file radical reaction techniques to cure the lens material include thermal radiation, infrared radiation, electron beam radiation, gamma radiation, ultraviolet (UV) radiation, and the like; combinations of such techniques may be used. The mold assembly defines a mold cavity for casting the lens, including an anterior mold for defining the anterior lens surface and a posterior mold for defining the posterior lens surface.
U.S. Pat. No. 5,271,875 describes a static cast molding method that permits molding of a finished lens in a mold cavity defined by a posterior mold and an anterior mold.
The hydrogels of the present invention are oxygen transporting, hydrolytically stable, biologically inert and transparent. When used in the formation of contact lenses, it is preferred that the subject hydrogels have water contents of from about 5 to about 70 weight percent. More preferred is about 25 to about 50 weight percent. Furthermore, it is preferred that such hydrogels have a modulus from about 20 g/m 2 to about 200 g/mm 2 , and more preferably from about 75 g/mm 2 to about 175 g/mm 2 .
As stated previously, the M 2 D x TMS-endcapped prepolymers are extremely easy to synthesize. There are fewer steps and components needed than found in previously known methods. This reduces the cost and time necessary for producing the hydrogels or contact lenses.
As an illustration of the present invention, several examples are provided below. These examples serve only to further illustrate aspects of the invention and should not be construed as limiting the invention.
EXAMPLE 1
Preparation of 1,3-bis(4-methacryloyloxybutyl)tetramethyl Disiloxane (M 2 )
To a 5 liter four neck resin flask equipped with a mechanical stirrer, Dean-Stark trap, heating mantle, water cooled condenser and thermometer was added 1,1 dimethyl-1-sila-2-oxacyclohexane (521 g, 4.0 mol), methacrylic acid (361 g, 4.2 mol), and concentrated sulfuric acid (25.5 g). To the reaction mixture was then added IL of cyclohexane and hydroquinone (0.95 g, 8.6 mmol) as a polymerization inhibitor. The reaction mixture was heated to reflux for five hours during which time 28 mL of water was collected. The reaction mixture was then cooled, divided and passed through two chromatography columns filled with 1 kg of alumina (packed using cyclohexane as eluent). The cyclohexane was removed using a rotary evaporator and the resultant M 2 was placed under vacuum (0.2 mm Hg) for one hour at 80° C. (yield, 80%; purity by gas chromatography, 96%).
EXAMPLE 2
Synthesis of Methacrylate End-Capped Poly Dimethylsiloxane (M 2 D 25 )
To a 1,000-mL round-bottom flask under dry nitrogen was added octamethylcyclotetrasiloxane (D 4 ) (371.0 g, 1.25 mol) and M 2 (27.7 g, 0.7 mol). Triflic acid (0.25%, 1.25 g, 8.3 mmol) was added as initiator. The reaction mixture was stirred for 24 hours with vigorous stirring at room temperature. Sodium bicarbonate (10 g, 0.119 mol) was then added and the reaction mixture was again stirred for 24 hours. The resultant solution was filtered though a 0.3-μ-pore-size Teflon® filter. The filtered solution was vacuum stripped and placed under vacuum (>0.1 mm Hg) at 50° C. to remove the unreacted silicone cyclics. The resulting silicone hydride-functionalized siloxane was a viscous, clear fluid: yield, 70%.
COMPARATIVE EXAMPLES 3-16
Formulations of the Hydrogel with Varying Ratios
Formulations comprising the following substituents were prepared: α,ω-Bis(methacryloxyalkyl)polysiloxane (M 2 D 25 ), methacryloxypropyl tris(trimethylsiloxy)silane (“TRIS”) and N,N-dimethyl acrylamide (DMA). Each formulation contained a constant amount of hexanol as solvent (20 parts) and Darocur-1173 as a photoinitiator (0.5 parts). All formulations were UV-cured between two glass plates for two (2) hours at room temperature. The resultant films were isolated, followed by extraction with ethanol for sixteen (16) hours and boiling water hydration for four (4) hours, then placed in borate buffered saline. The ratios of the various substituents were varied, with the resulting properties noted.
The water contents and isopropanol extractables for films cast according to the procedures set forth above were measured gravimetrically. The tensile and tear properties were determined in buffered saline, according to the standard ASTM procedures 1708 and 1938 respectively. The oxygen permeabilities were determined by polargraphic methods taking the edge effect into consideration. (See Fatt, Rasson and Melpolder, Int'l Contact Lens Clinic , v. 14, 389 (1987)).
TABLE 1 Films prepared using M 2 D 25 endcapped with 0% mole trimethylsilyl DMA TRIS M 2 D 25 DK H 2 O Weight Modulus H 2 O Example (parts) (parts) (parts) (Barrers) (%) Loss (%) (g/mm 2 ) trans 3 20.00 39.50 20.00 179.00 11.61 17.83 181 1.05 4 23.95 33.10 22.45 131.60 17.94 19.25 223 14.91 5 35.00 24.50 20.00 85.00 32.70 21.19 212 79.96 6 35.00 20.00 24.50 196.00 32.19 21.48 290 91.35 7 20.00 29.50 30.00 181.90 10.65 17.72 306 9.03 8 20.00 39.50 20.00 189.30 10.12 18.81 204 4.53 9 20.00 34.50 25.00 139.40 11.56 18.65 238 6.93 10 35.00 20.00 24.50 91.10 32.21 19.83 305 70.4 11 29.50 20.00 30.00 129.40 23.67 19.93 355 45.21 12 24.75 24.75 30.00 120.20 17.36 21.80 327 19.46 13 35.00 24.50 20.00 85.40 34.70 21.35 219 74.07 14 20.00 29.50 30.00 201.90 12.19 21.10 314 4.59 15 31.45 23.35 24.70 113.30 29.55 21.85 274 51.83 16 27.90 26.70 24.90 125.20 23.42 21.55 260 22.25
Silicone hydrogel prepared with the above components produce films with generally high oxygen permeability. It is noted that the modulus of some of these films was too high for soft contact lens applications.
EXAMPLES 17-30
Films Prepared with M 2 D 25 Endcapped with 10% Mole Trimethylsilyl
This prepolymer was prepared by same procedure as above except that for the following amounts: M 2 9.08 grams, D 4 40.57 grams, T 2 (hexamethyldisiloxane) 0.35 grams and triflic acid 0.125 grams.
TABLE 2 Films prepared using M 2 D 25 endcapped with 10% mole trimethylsilyl DMA TRIS M 2 D 25 DK H 2 O Weight Modulus H 2 O Example (parts) (parts) (parts) (Barrers) (%) Loss (%) (g/mm 2 ) trans 17 20.00 39.50 20.00 200.00 11.69 17.42 163 1.16 18 23.95 33.10 22.45 160.40 18.04 19.47 191 9.53 19 35.00 24.50 20.00 80.40 32.62 19.48 179 91.35 20 35.00 20.00 24.50 77.80 33.89 24.61 263 2.68 21 20.00 29.50 30.00 187.30 10.65 17.72 246 2.79 22 20.00 39.50 20.00 208.00 9.97 18.70 164 6.04 23 20.00 34.50 25.00 198.60 11.93 19.15 215 7.72 24 35.00 20.00 24.50 84.50 31.80 19.27 250 90.99 25 29.50 20.00 30.00 120.20 23.33 19.19 329 40.44 26 24.75 24.75 30.00 164.10 17.43 19.55 275 20.54 27 35.00 24.50 20.00 75.80 34.06 21.03 190 79.86 28 20.00 29.50 30.00 158.30 11.88 20.16 284 2.91 29 31.45 23.35 24.70 102.70 27.03 22.14 272 59.79 30 27.90 26.70 24.90 119.70 22.97 21.11 232 22.55
Films containing M 2 D 25 endcapped with 10% mole trimethylsilyl showed a reduction in modulus as compared to Examples 3-16. The oxygen permeability was acceptable.
EXAMPLES 31-44
Films Prepared with M 2 D 25 Endcapped with 25% Mole Trimethylsilyl
This prepolymer was prepared by same procedure as above except that for the following amounts: M 2 8.98 grams, D 4 40.14 grams, T 2 0.88 grams and triflic acid 0.125 grams.
TABLE 3 Films prepared using M 2 D 25 endcapped with 25% mole trimethylsilyl DMA TRIS M 2 D 25 DK H 2 O Weight Modulus H 2 O Example (parts) (parts) (parts) (Barrers) (%) Loss (%) (g/mm 2 ) trans 31 20.00 39.50 20.00 126.60 12.17 18.34 137 0.65 32 23.95 33.10 22.45 134.40 18.21 18.68 158 7.47 33 35.00 24.50 20.00 92.50 33.67 18.84 161 69.93 34 35.00 20.00 24.50 79.00 35.04 21.71 227 90.15 35 20.00 29.50 30.00 67.30 12.44 24.39 250 1.96 36 20.00 39.50 20.00 156.50 9.56 20.23 139 4.53 37 20.00 34.50 25.00 169.90 11.08 18.77 181 8.43 38 35.00 20.00 24.50 87.40 32.65 20.96 232 91.11 39 29.50 20.00 30.00 129.50 25.59 20.36 282 68.92 40 24.75 24.75 30.00 201.10 18.96 20.84 241 17.73 41 35.00 24.50 20.00 87.50 34.89 21.93 155 89.85 42 20.00 29.50 30.00 126.70 12.80 21.54 165 2.57 43 31.45 23.35 24.70 92.80 29.32 21.91 209 59.53 44 27.90 26.70 24.90 142.00 24.58 21.56 197 29.18
Films made with M 2 D 25 endcapped with 25% mole trimethylsilyl showed a decrease modulus as compared to Examples 17-30.
EXAMPLES 45-46
Films Prepared with M 2 D 25 Endcapped with 40% Mole Trimethylsilyl
This prepolymer was prepared by same procedure as above except that for the following amounts: M 2 8.89 grams, D 4 39.72 grams, T 2 1.39 grams and triflic acid 0.125 grams.
TABLE 4 Films prepared using M 2 D 25 endcapped with 40% mole trimethylsilyl DMA NVP TRIS M 2 D 25 DK H 2 O Weight Modulus Example (parts) (parts) (parts) (parts) (Barrers) (%) Loss (%) (g/mm 2 ) 45 17.50 17.50 24.50 20.00 72.90 35.05 32.50 126 46 17.50 17.50 24.50 20.00 76.30 36.03 23.81 120
Films containing M 2 D 25 endcapped with 40% mole trimethylsilyl showed a reduction in modulus as compared to Examples 31-44.
EXAMPLES 47-48
Films Prepared with M 2 D 5 Endcapped with 50% Mole Trimethylsilyl
This prepolymer was prepared by same procedure as above except that for the follow amounts: M 2 8.82 grams, D 4 39.45 grams, T 2 1.73 grams and triflic acid 0.125 grams.
TABLE 5 Films prepared using M 2 D 25 endcapped with 50% mole trimethylsilyl DMA NVP TRIS M 2 D 25 DK H 2 O Weight Modulus Example (parts) (parts) (parts) (parts) (Barrers) (%) Loss (%) (g/mm 2 ) 47 17.50 17.50 24.50 20.00 65.30 36.55 24.33 109 48 17.50 17.50 24.50 20.00 76.30 35.53 24.86 103
Films containing M 2 D 25 endcapped with 50% mole trimethylsilyl showed a reduction in modulus as compared to Examples 45,46.
Many other modification and variations of the present invention are possible to the skilled practitioner in the field in light of the teachings herein. It is therefore understood that, within the scope of the claims, the present invention can be practiced other than as herein specifically described. | A method for reducing the modulus of polymer silicone hydrogel compositions by employing monomeric polysiloxanes endcapped with trimethylsilyl to reduce the crosslinking density of the hydrogel. The synthesis consists of a single vessel acid catalyzed ring opening polymerization and may be employed to produce copolymers useful as hydrogel contact lens materials. | 2 |
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention generally relates to post support devices and methods for wooden support posts that are typically connected to concrete piers or other surfaces such as wood porches, balconies or surfaces where water or moisture pervades the environment, and more particularly to post support devices and methods to minimize or repair rotting at the base in such wooden support posts because of prolonged exposure to the elements.
[0003] 2. Description of Related Art
[0004] In the field of construction there is a common problem of wood support posts rotting at the base because of prolonged exposure to the elements. These posts may be connected to concrete piers or other surfaces such as wood porches, balconies or any surface where water or moisture pervades the environment.
[0005] End grain of dimensional lumber has a natural capillary structure that aids the tree when it is living but which can be detrimental to wooden structural members if kept constantly wet. Water is sucked up by the end grain thus creating an optimal environment for rot and mould to establish itself and eventually destroy the integrity of the support post.
[0006] In other environments, pests such as termites are the threat. Open access to wood fiber at ground or surface level allows termites to gain access to a food source and begin their destructive work.
[0007] Support posts that are structurally compromised at the base can be a very expensive problem to fix. Support posts are often in such sizes as 6×6 (inches) dimensions or greater and are usually well connected into a supported framed structure above the remote end of the post making their removal laborious and costly.
[0008] These support posts rest upon concrete piers below porches, or decks or other similar structures, or they can be resting on the top decking surface of a porch and may be turned on a lathe, shaped and painted for decorative or cosmetic effect, in addition to supporting a roof structure above.
[0009] Rot and termite damage tends to progress up the inside core of a post much like a cone. This means that while a small area of rot may be visible from the exterior, the rot may extend much higher within the post.
[0010] There are a number of examples in the prior art of elevated post support devices designed to be used during new construction where easy installation is possible because the support post has not yet been installed into the structure. One can easily gain open access to the bottom of the post or the device is already secured to a concrete footing and the post can be dropped into position over the device.
[0011] However, if a rotted post is to be repaired, the prior art envisions that the rotting post be completely removed from the structure first and that a new post be installed in the same fashion and procedure as if it were new construction. The prior art envisions that the method of installation or repair accommodate to the height restrictions of the device rather than the device being capable of adapting within a typical and modest height range of rot within a post.
[0012] This means that the repair solution required when using the prior art devices necessitates complete removal of the post, which entails new material cost and labor. The prior art devices and methods do not lend themselves easily to situations where one desires to remove only the rotted portion of the post so that the rest of the post can be saved, thereby reducing replacement cost and labor. And yet this is a desirable choice given the high cost of replacing large structural posts that are typically securely connected to the remaining framing structure above while only five or six inches of rot exists at the bottom.
[0013] The prior art devices are only designed to provide a support post sufficient building code mandated clearance of at least one inch for all non-preservative treated ends of posts. But once rot sets in it almost always extends further than one inch from the surface of the grade. In fact the extent of rot may vary significantly depending of many factors such as snow and ice accumulations, direct or indirect exposure to rain or moisture.
[0014] While the prior art devices could be modified to accommodate whatever height one might anticipate rot could extend to, doing so would require numerous different height sizes to be made in anticipation of varying extents of rot. Or a single design which might be tall enough to function in a less common situation where the rot extends far above average heights might also be contemplated to cover as many instances as possible.
[0015] But such a device would be more than is required in many other instances, thus would be more expensive to manufacture. That is perhaps one of the reasons why the prior art has focused on devices which only meet the minimum building code elevation of one inch above a surface.
[0016] Another problem with the prior art devices is that they do not allow for variability during the installation, even within a reasonable range, so that the height at which a rotted post is cut is close to where healthy wood begins to predominate. The prior art devices offer no range of elevation in which to work beyond their discrete height.
[0017] The prior art devices are designed so that they connect to the post by way of external vertical planer surfaces that run up along the wall of the post and are secured to the post with fasteners. As a result, there is no seal to prevent water from seeping in between the post and the vertical planar surface. They are simply compressed against the post and screwed in place. As a result moisture is retained longer between post and planar surface and can gain access to the core of the post through the entry point of the fastener. These weaknesses leave the new post no better protected from moisture damage and eventual structural decay than the previous post with the same supporting device.
[0018] Some prior art (Scholl) devices are designed to protect a pier and a post combination by using compressive means around a post to create a seal in combination with a large cavity that encircles post and pier. It does not envision a mechanical seal which cuts into and penetrates beyond the plane of the post wall. This is clearly advantageous given its permanency and long term reliability when compared to applying caulking around the perimeter of the post where the support device planar surfaces terminate.
[0019] And yet one more factor is ignored by the prior art which renders their use ineffective or impractical in repair or renovation situations long after original construction. These are instances where a post to be repaired has been connected to a concrete surface by way of a device which has some kind of appendage or leg embedded into the concrete. This occurs at the time of construction whereby an anchoring appendage is submerged into wet cement and left to cure.
[0020] If one of the prior art devices were desired to be used in such a repair situation, it would entail cutting off the embedded appendage and removing a portion of concrete sufficient for another like device to be embedded within new cement poured into this cavity within the pier. This would be laborious, costly and time consuming. A device that is surface mounted to cured concrete would be the only reasonable solution even though the old embedded anchoring appendage would still have to be cut off.
[0021] To further demonstrate the utility and benefit of having a device with both variability in height range and a means of sealing and protecting the connection between post and device, consider one element of a repair technique that would be part of the method used when employing such an ideal device.
[0022] A simple method of fixing a rotted post that sits directly on a surface, without any kind of post support anchor, is to cut the post above the rotted portion and remove it. A new replacement filler block could be cut from identically dimensioned lumber so that it would fit snuggly within the void. Construction adhesives may be applied to the contact surfaces of the end of the old post and replacement filler block. However, this would likely doom the filler block to the same fate as its predecessor given that exposure to the elements would continue at the post to base surface interface and also at the joint between the filler block and post.
[0023] Alternatively, a traditional metal post support device could be used to secure the replacement filler block whereby screws pass through it into the filler piece connecting the two. The support device with the attached filler block can now be fitted underneath the hanging post and fastened to the concrete pier. In such a case, the height of any post support device would also have to be accounted for so that it and the filler block closely filled the void.
[0024] From a functional perspective, these two solutions, however crude, would at best address the compression strength required of the adapted support post. However, the lateral strength would still be a concern given that adhesive is all that binds the filler block and post.
[0025] This concept does offer some cosmetic benefits as it creates a support post with an identical profile as the original post. Further sanding and use of resin fillers and painting can result in a high quality aesthetic finish close to the original. However the joints or interfaces between surface, filler block and post remain exposed to the elements.
[0026] If the joint is not repaired properly and it remains close enough to the base surface such that it is within the zone of exposure to the elements, the process of rot is set to repeat itself once again. This concept is incomplete and far from optimum.
[0027] In summary, there remain significant issues of concern with this method of a repair such as inadequate lateral or torsion strength at the union of the old and new filler material, lack of protection of the union interfaces from further exposure to the elements or pests, and keeping the base of the filler block post bottom dry.
[0028] Therefore there is a need for an elevated surface mounted post support device that a) addresses the need for a permanent and reliable long term mechanical sealing system between post walls and the vertical planar surfaces of the device that connect to and secure the post; b) provides a high degree of compression, lateral impact and torsion strength; c) meets the minimum building code gap requirements between post and surface; and d) can be used in a range of situations where the progression of rot within a support post extends to varying heights.
[0029] The devices and methods of the present invention are provided to fulfill one or more of these needs as will be understood from the following description.
SUMMARY OF THE INVENTION
[0030] In order to address some of the shortcomings in the prior art, some aspects of the present invention provide a post support device that enables a rotted base portion of a wooden support post to be removed in situ and the remaining end of the support post to be secured for regained structural integrity, the device comprising a base adapted to being attached to the surface; elevation support means in cooperation with the base for supporting the post or a filler block if one is used in a position above the base; at least two cover plates, each cover plate being adapted to covering a portion of the exterior of the post, each cover plate further including an elongate flange portion facing inward towards the post and being positioned generally transverse to the longitudinal axis of the post, said flange portion including a leading cutting edge to enable the flange portion to bite into the surface material of the post upon the application of force to the flange portion to provide a mechanical seal between the flange portion and the post; first fastening means for securing each cover plate to the post; and second fastening means for securing the base and the elevation support means to the post or the filler block if one is used.
[0031] In some embodiments, the cover plate may define a top edge and the flange portion may be adjacent the top edge, the top edge may further include at least one V-shaped cutout to enable the flange portions on either side of the cutout a limited range of movement relative to each other.
[0032] In some embodiments, the elevation support means may comprise a raised area embossed into the base. In some embodiments, the elevation support means may comprise a formed member being connectable to the base and having an elevational thickness that supports the post or the filler block if one is used in a position at that distance above the base. Preferably, the elevational thickness is at least one inch.
[0033] In some embodiments the device may further include upwardly extending tabs on an upper surface of the base wherein the tabs are located on the inside and are aligned with the cover plate when the device is assembled, and third fastening means for securing each cover plate to at least one of said tabs.
[0034] In some embodiments, the elevation support means may define a periphery that is smaller than the periphery of the post or the filler block if one is used.
[0035] In some embodiments, the cover plates together in the assembled device completely envelope the periphery of the post. In some embodiments, each cover plate may further includes complementary overlapping side edges at each end, one being an underlying edge and the other being an overlying edge, wherein the overlying edge of one cover plate overlaps with the underlying edge of the adjacent cover plate. Fourth fastening means may be included for interconnecting the overlapping side edges on adjacent cover plates and simultaneously securing them to the post.
[0036] Preferred embodiments may comprise several components; a planar base with either an integrally formed elevated zone contained within the periphery of post walls or a separate component that creates a taller space between the planar base and the post, either of which would connect to the post bottom elevating it from the surface; at least two post cover panels that wrap around the post above and below a joint between a new filler block material and the original post (if a filler block were used); inwardly bent sharp edges adjacent the upper edges of the cover panels which can be driven or impaled into the side wall of the post to create a mechanical seal; and fasteners to connect the parts to each other and to the post.
[0037] The devices of the present invention could be used in new construction applications where a filler block would not be necessary as the device would be screwed directly onto the end of the new post followed by the cover panels. Thereafter, the new post and base support device could be fastened to the concrete pier. However, the devices' full potential, greatest value and most unique attributes are fully realized when used to repair old rotted wooden support posts.
[0038] The planar base surface separates the bottom of the post from the concrete pier or deck surface to which it connects, and where moisture or pests typically reside. At a minimum this planar base surface would be elevated at least ¼ inch by virtue of embossed or stamping the base material. The planar base may connected either directly to the end of a new post or to a replacement filler block by conventional fastening means. In the case of repair of an old post, the filler block fits directly underneath the cut end of the old post.
[0039] In another embodiments there may be a separate component sometime called a “stand off” that lifts the post higher above the concrete surface. Ideally this space should at least meet the building code minimum standard of 1″ for use with un-treated post ends. This “stand off” component is preferably made of square or rectangular tubing or could be made of stamped metal or an injection molded high density synthetic material. If it is made of metal it would be welded to the base plate of the device. In either case the “stand off” component is not subject to moisture damage and serves the purpose of elevating the bottom of the filler block or the original post (if a filler block is not used) to meet the minimum building code standards.
[0040] The two post cover panels wrap around the post overlapping each other and connecting tightly, while the upper edge of the panels have sharp inwardly pointing flanges or blades that cut circumferentially into the post walls creating a mechanical seal. Fasteners are screwed through overlapping and non overlapping portions of the panels above and below the filler block-to-post joint ensuring the entire combination of post and device becomes strong.
[0041] The ideal device is intended to connect either directly to the end of a support post or to a replacement filler block and the remaining cut end of a support post, so as to; a) provide compression, lateral impact and torsion strength; b) protectively seal around the post walls above the joint; and c) provide a dry and sealed joint connection between the bottom of the filler block and the base connection means to a surface. It does not address the issue of providing a compressive seal while covering or sheltering an entire post to pier connection.
[0042] The cover panels can be designed for a standard height of approximately 6 to 8 inches, which might be sufficient for vast majority of rotted post repair situations, or they may be shorter or taller, as required. The elevated embossed or “stand off” portion of the device could remain constant. But the height of the cover panels allows for a reasonable range within which to choose exactly where to cut off a rotted portion of post. Since the extent of rot may differ from one post to another it is useful to have a device which can affordably operate and adapt in these situations.
[0043] It should be understood that the prior art post support devices are designed to only marginally separate a post from a surface; typically no more than one inch. They are designed to provide only a discrete separation between a post and surface rendering them ineffective in most post repair situations. And, because there is no variability in their application, they work best in new construction only. If they must be used for repair work, the entire post must be replaced with a new post. No seal is provided where the side members of these devices connect to the post. The side members are usually intended to be nailed or screw against the post wall.
[0044] As has been shown herein, the present invention with the cover panels and the ability to use them with a custom sized filler block (within a range depending on the height of the cover panels) is easily adaptable to situations where much more than one or two inches of rot must be removed. As well, the sharp edged blade of the cover panels creates a reliable and clean looking seal for better protection. The concept of the sharp edged blade is vast improvement over any concept that provides a member that merely sits flat against a post wall. In such a case, a bead of caulking would have to be applied around the entire perimeter of the post. The caulking would account for the integrity of the entire seal and require frequent maintenance and attention. In contrast, the present invention that provides a mechanical seal for all but the very small corner portions improves long term performance significantly.
BRIEF DESCRIPTION OF THE DRAWINGS
[0045] For a better understanding of the present invention and to show more clearly how it may be carried into effect, reference is made by way of example to the accompanying drawings in which:
[0046] FIG. 1 is a perspective view of an embodiment of a post support device in accordance with the present invention showing the finished appearance with the cutting blades of the cover panels embedded in the side walls of the post.
[0047] FIG. 2 is a perspective view of the device in FIG. 1 with a portion cut away, partially revealing an embodiment of the stand-off base and the post inside the device;
[0048] FIG. 3 is a perspective view of the device in FIG. 1 without the cover panels to illustrate how a filler block is used with the apparatus for post repair applications and a cutaway perspective of the filler block shows screws that come from underneath the stand-off and base;
[0049] FIG. 4 is a top view of the device in FIG. 1 without the post to illustrate how the cover panels mate at the overlaps and are fastened together;
[0050] FIG. 5 is a perspective view of a cover panel of the device in FIG. 1 ;
[0051] FIG. 6 is a top view of an embodiment of a flat base;
[0052] FIG. 7 is a perspective view of an embodiment of the stand-off base;
[0053] FIG. 8 is a cross section of another embodiment of a stand-off base made from a single piece of sheet metal;
[0054] FIG. 9 is a perspective view of the device in FIG. 1 without the cover plates;
[0055] FIG. 10 is a perspective view post on top of an embossed elevated base rather than using the higher elevated stand-off component.
[0056] FIG. 11 is a cross section showing the device in FIG. 1 as used in new construction applications when a stand-off component is employed with a single continuous post;
[0057] FIG. 12 is a cross section showing the device in FIG. 1 as used in a post renovation application when a stand-off component is employed with a filler block;
[0058] FIG. 13 is a cross section perpendicular to that of FIG. 12 showing the device in FIG. 1 with a filler block and a stand-off component;
[0059] FIG. 14 is a cross section showing an embodiment of the device with an elevated embossed base used with a single continuous post;
[0060] FIG. 15 is a cross section perpendicular to that of FIG. 14 ;
[0061] FIG. 16 is a cross section showing an embodiment of the device with an embossed elevated base as used in with a continuous post; and
[0062] FIG. 17 is a cross section perpendicular to that of FIG. 16 .
DETAILED DESCRIPTION OF THE INVENTION
[0063] For the purposes of promoting an understanding of the principles of the invention, reference will now be made to the exemplary embodiments illustrated in the drawings, and specific language will be used to describe the same. It will nevertheless be understood that no limitation of the scope of the invention is thereby intended. Any alterations and further modifications of the inventive features illustrated herein, and any additional applications of the principles of the invention as illustrated herein, which would occur to one skilled in the relevant art and having possession of this disclosure, are to be considered within the scope of the invention.
[0064] Referring to FIGS. 1-3 , there is depicted an embodiment of a post support device in accordance the present invention. Post support device 5 comprises a base such as flat base plate 10 and an elevation support means in cooperation with the base. Depending on the application, the elevation support means may be an integrally formed elevated zone 11 that is embossed into the base plate 10 , preferably contained within the periphery of post walls, that supports the post in an elevated position above the base hence the ground) such as, for example, by a ¼ inch or more. Alternatively, the elevation support means may be a separate formed member being connectable to the base and having an elevational thickness that supports the post or the filler block if one is used in a position at that distance above the base. An example of a separate formed member is stand-off component 18 which creates a taller space between planar base 10 and post 2 . Stand off component 18 may comprise a pair of square or rectangular tubes that are joined to the base 10 , as shown. Either of these structures—the elevated zone 11 and the stand-off component 18 —elevate the bottom of post 2 from the planar base 10 .
[0065] Post support device 5 further comprises a pair of cover panels 14 that overlap each other on two faces along complementary overlapping side edges or tabs 30 and 32 : tab 30 defining an underlying edge and tab 32 defining an overlying edge. Each cover panel 14 has planar sides that are perpendicular to each other, each side having a width dimensioned to cover the corresponding sides of the post 2 , and a typical height of 6-8 inches, or as required for specific applications. Along the top edge of each side of the cover panel 14 is provided a flange 26 bent inward along the top at approximately 90 degrees to the side (hence the post) having a sharp cutting edge 26 a that is adapted to cut across the grain (transverse to the longitudinal axis of the post) into the side wall of the post 2 , thereby the flange 26 functions as a blade.
[0066] There is also provided a “V” cut 28 at the corner of the vertical bend in each cover panel 14 which is of sufficient size and depth to permit easy independent lateral movement of the adjacent portions of the planer surfaces of the cover panels. The “V” cut is important because, during the installation of the cover panel 14 , lateral strikes with a hammer to the top portions of the sides on the cover panel are required to engage the cutting blade 26 into the side wall of the post, and the “V” cut 28 enables the adjacent top portions of each side on the cover panel 14 to be driven inward.
[0067] Furthermore, the side corners 34 of each flange or blade, adjacent to the “V” cut 28 , are preferably cut at an angle greater than 90 degrees to the cutting edge 26 a , more preferably greater than 110 degrees, so that the side corners 34 more easily initiate engagement of the blade into the wood. Installation requires that the bend line at corner of the cover panel 14 and the post corner be aligned with each other. Once they are in close proximity to one another, a light to moderate strike of a hammer at the corner near the “V” cut 28 of the cover panel 14 is sufficient to engage the two adjacent corner points 34 of both cutting blades 26 across the longitudinal grain of the post. Further strikes along one cutting blade 26 at a time to the end of each cover panel 14 will set the blade 26 into the post. First fastening means such as wood screws 23 , just below the top edge and approximately at mid span of the cover panel 14 , may be inserted through holes 38 and used to fully pull the cutting blade into the post to provide a water tight seal.
[0068] The impaling the cutting blades into the side walls of the post is more like a clamping action with a hinge in vertical alignment with the corner of the post whereby the cutting edges 26 are initiating the cut into the post near the corner of the cover panel 14 and post. Therefore the angle of each corner 34 assists in making the initial cut into the wood in cleaner manner than if the corner were a 90 degree corner. With a 90 degree, corner the wood fiber is more apt to be ripped and crushed as the point at the corner 34 of the blade 26 arcs around the hinge point into the side wall of the post. Whereas, with the angled corner 34 , the cutting edge 26 a of the blade 26 is better able to cut the wood grain progressively as it moves across the width of the post. The result is a clean entry point of the blade 26 into the wood at both visible “V” cuts in the post.
[0069] Fourth fastening means such as self drilling screws 8 may be used to fasten the cover panels 14 together at overlapping tabs 30 and 32 , and to the post. A larger screw 4 is shown in the middle of the cover panel which can be used if desired in applications requiring increased strength, such as, for example, in hurricane environments. An optional third fastening means such as self drilling screw 33 may be used at the base and mid span of the cover panel which fits through a hole in the cover panel and then self drills and taps into a vertical tab 12 formed in the base 10 . In this manner, a complete seal is made around the periphery of the post, except for the small V cut openings 28 at the corners, for a support base that is dry, water resistant, and has excellent compression, and torsion strength.
[0070] Referring to FIGS. 4 and 5 , further illustration of the self drilling screws 8 and the cover panels 14 are provided. The screws 8 are installed through holes 35 along the overlapping tabs 30 and 32 locking the cover panels together and creating a strong and rigid shell that completely surrounds the base of the post. The cover panels abut themselves up against the vertical tabs 12 formed into the base 10 as they are placed in position around opposing corners of the post. The vertical tabs are closely aligned with the plane of the post walls so that they contact or come close to contacting the back side of the cover panels 14 . Self drilling screws 33 can also be inserted through holes 37 at the bottom edge of the cover panels 14 to fasten the panels to the vertical tabs 12 and the base 10 . The holding power of this fastening means is in addition to the second fastening means such as larger pan head screws 19 that secure the post or a filler block 21 to the stand-off component 18 and the base. In some environments where hurricanes are possible, it may be necessary to use a middle hole 36 that may be provided in the center of the cover panel and drive a larger fastener 4 through and into the post from opposing sides to provide additional lateral means of support from vertical lift from high winds. The screws 23 along the top edge of the cover panels also act as lateral fastening means to the post but the addition of the larger fastener 4 offers additional strength if needed.
[0071] Once the blades 26 have been firmly embedded into the respective sidewalls of the posts, a complete water seal has been achieved around the post except for the small “V” shaped openings 28 at the corners of the panels. These small areas are sealed with a small dab of exterior caulking to complete a perfect watertight seal. These caulking points can be inspected annually, and because of their small size, can easily be peeled away and new caulking applied if necessary.
[0072] A benefit of the waterproof shell around the base of the post that the cover panels 14 provide is that the end grain of the post is in a protected zone above where any water may pool. All side installed screws are also sealed effectively by the tight tolerances of the through holes and, since water cannot dribble down between the cover panels and the post walls, it cannot also find its way into the penetration holes in the post. Snow and ice or heavy rains have no effect on the integrity of the base and lower zone of the post that would otherwise be exposed when using the support bases found in the prior art.
[0073] Referring to FIGS. 6-8 , the base 10 that is used in conjunction with the stand-off component 18 has large holes 16 in the inner zone that allow the larger heads of fasteners 19 to pass through and into the tubular formation of the stand-off component 18 . A similar sized hole 20 is aligned directly over holes 16 in the base with smaller holes 22 directly above permitting the screw 19 to penetrate the bottom face of the post 2 or a filler block 21 . The stand-off tubes 18 being welded to the base 10 form an integral unit that can be designed to any height, but preferably at least 1″ above the base to comply with certain building code standards for untreated wood posts.
[0074] Another simple configuration of base and stand-off component entails forming both tube shapes from a single piece of sheet steel and welding it to the top surface of the base 10 .
[0075] Also in FIG. 6 are shown the vertical tabs 12 which are ideally formed from the same material as the base to save time and effort. The smaller outer holes 7 allow for wood screws or concrete fasteners to protrude through and secure the base to a surface.
[0076] There are basically two scenarios where the device is designed to be used: in post repair situations and in new construction. Post repair situations will require that the rotted lower portion of the post be removed with a saw, preferably with a right angled cross cut that allows a similarly dimensioned piece of lumber or similar materials (i.e. filler block 21 ) to fit between the remote post end and the stand-off component 18 or elevated embossed base 11 , as the case may be depending which embodiment of the base 10 is used. Either the stand-off 18 or embossed base 11 embodiments may be used in new construction but the stand-off provides better protection from moisture given the higher elevation. When a new post is used with either the stand-off 18 or the elevated embossed base 11 , the cover panels 14 function in the same manner by wrapping around the post, overlapping along their respective side edges (overlapping tabs), with the blades 26 penetrating the post walls.
[0077] For post repair scenarios, the height of the cover panels can be adapted to varying lengths to accommodate a range of common rotting patterns and depths. The benefit to this well appreciated by both homeowners and builders who face a situation of having to extricate a tall, heavy support post built into the framing of an upper deck or balcony. The only portion of the post that is damaged is typically the lower few inches and which requires repair. By using the stand-off embodiment of the device the damaged portion is easily cut off and the original mounting bracket cut off from the concrete or wood surface as well using a reciprocating saw with a metal blade. The filler block 21 is fastened first to the stand-off 18 with the screws 19 and cut to precise height so that when the block 21 and the device are inserted into the opening beneath the cut post there is reasonably tight fit. A small amount of heavy duty construction adhesive can be applied between the mating surfaces of the post 2 and the filler block 21 to enhance the union. Once the cover panels 14 surround the union between post 2 and filler block 21 , the post and support base become one rigid unitary piece whereby both compression loads and torsion loads are effectively resisted and withstood. Since the top end of the post remains fixed above into the framing of the upper deck the post remains very strong and resistant to lateral loads at the top or bottom ends of the post. In effect, the integrity of the post and deck or balcony has been restored and the lower region of the post will remain dry and healthy for long periods of time. The appearance of the finished application is improved beyond that offered by solutions found in the prior art, which may be appealing to a certain segment of the population.
[0078] Referring to FIG. 9 , there is depicted a transparent perspective view of the various components of the apparatus showing the relation of post connection means to the base and stand-off 18 . This view without the cover panels 14 reveals how a filler-block 21 can also be employed easily to adapt to the varying and unpredictable range of rot within old posts yet commonly within the range of heights of the cover panels that are manufactured. This view also depicts the fact that in the ideal device, the stand-off component 18 or the periphery of the flat elevated zone 11 of the embossed base lies within the periphery of the post or filler block walls. This ensures that if water somehow gained access on the inside the cover panels, that it would be free to drip down to the base 10 surface and keep the bottom of the post dry.
[0079] Referring to FIG. 10 , there is depicted a similar perspective view to illustrate the relative positions of the post overtop the embossed version of the base 10 . Vertical tabs 12 are shown in this illustration but are optional if a single continuous post application is employed. This is because the post can be firmly secured to the base 10 by fasteners 19 from underneath the base. However, in a post repair application it is possible that the tabs 12 may be used for two purposes. First they may serve to provide some alignment assistance of the panels to the base 10 but largely that is provided for if the filler-block 21 is centered evenly over the elevated zone 11 of the embossed base. Secondly, the cover panels are secured to the post by upper screws 8 ; then secured to the lower filler block by two optional side screws 4 ; the filler-block further fastened to the base by large screws 19 . Lastly, the cover panels may be mechanically secured to the base 10 by using self drilling screws 33 to penetrate the vertical tabs 12 of the embossed base 10 .
[0080] Referring to FIGS. 11 and 12 there is depicted a cross sectional view showing how the apparatus is used in new construction applications when a stand-off component 18 is employed. The cutting blades 26 are fully embedded into the side wall of the post. Wood screws 23 are shown also penetrating the side of the post 2 . The heads of the larger screws 19 are shown inside the stand-off tubes 18 . Self drilling screws 33 are shown at the base of the cover panel penetrating through the vertical tabs 12 and into the side of the stand-off. Not only is the post secured laterally to the cover panels and the base 10 by virtue of the stand-off component 18 but also by the lower lateral screws 33 through the panel and into tab 12 panel near the base 10 . FIG. 9A shows how the apparatus is used in post repair applications using the original post and a filler-block 21 .
[0081] Referring to FIG. 13 , there is depicted the same apparatus and post configuration as in FIG. 12 but rotated 90 degrees showing the other side of the stand-off 18 and providing a view of the overlapping fasteners 8 , top mid span fasteners 23 , and optional side screw 4 .
[0082] Referring to FIGS. 14 and 15 , there is depicted cross sectional views showing how the apparatus is used in new construction applications when an elevated embossed base 10 is employed with a single continuous post 2 . Fasteners on the sides of the cover panels are not shown in this view in order to emphasize the fastening means at the bottom of the post. The heads of the larger screws are shown fitting inside the cavity under the elevated base. FIG. 15 shows a view that is rotated 90 degrees and illustrates the positions of the various side fasteners through the cover panels. The view begins on the left from the V cut corner of the post thus by-passing the left cutting blade.
[0083] Referring to FIGS. 16 and 17 , there is depicted cross sectional views showing how the apparatus is used in post repair applications when an embossed 11 elevated base 10 is employed. The cutting blades 26 are fully embedded into the side wall of the post. The heads of the larger screws 19 are shown fitting inside the cavity under the elevated base. FIG. 17 is another cross sectional view of a the same apparatus but rotated 90 degrees to show the details of the screws 8 that secure the cover panels 14 together, the mid span screws 23 that pull the blades 26 in tighter against the post walls and the optional screw 4 in the middle of the cover panel. The cross sectional view of the left side of the apparatus also begins between the V cut at the corner, thus omitting the view of the blade 26 on this view.
[0084] The following describes both the characteristics of the device and the method of employing it.
[0085] The first step of using an embodiment of the present invention is to locate a support post with a rotted bottom portion. The extent of the rot must be determined and one should allow a zone of safety of at least 1 inch above the rotted area. A horizontal line is circumscribed around the post. The structure above the post should be temporarily supported by another post while the rotted portion is cut off, preferably with a reciprocating or circular saw. The void between the post end and the surface of the grade or concrete is accurately measured. With the elevation of the base of the device in mind, either with an embossed surface or a “stand off” component, the height of the filler block must be accurately measured so that the combined heights of base of the device and filler block exactly match that of the void. Depending on the embodiment of the device, the filler block is either a) secured to the embossed base of the device by standard fasteners that screw up through the support base of the device from underneath its bottom surface; or b) secured to the “stand off” component which is welded to the base plate to create a minimum one inch elevation above the concrete grade. The filler block would usually be identical nominally sized lumber as that of the post but could be any high density synthetic material.
[0086] It is the cover panels in conjunction with the post base device and filler block that provide the heretofore unaddressed benefits of improved lateral and torsion strength, a near perfect mechanical seal (except for the small exposed corner portion which is covered by a dab of caulking) and the freedom to variably select where to cut the old post within the range of the height of the panels while removing the rotted portion.
[0087] It should be noted that a variety of flat planer bases that elevate the end of the filler block above the surface could potentially be used with the post cover panels and achieve the effect of maintaining a firmly connected base to surface grade connection. But it is the design of the base of this device in concert with the cover panels which provide additional protection against any water or moisture that may accumulate on the surface of the base proximate to the end of the post or filler block.
[0088] An embossed elevated base would provide a minimum level of protection from surface moisture. A “stand off” component would provide a greater level of protection with building code standards in mind. A “stand off” component with a filler block would provide even greater protection to a repaired post. In any of these three scenarios, the post cover panels provide protection from water and insects and provide excellent torsion and lateral strength.
[0089] Construction adhesive is applied to the top surface of the filler block. The support base with attached filler block is then fitted into the void. Any excess adhesive that is squeezed out can be wiped off for a clean installation. The support base itself has either an embossed elevated center portion or taller “stand off” component, the perimeter lines of which lie within the periphery of the bottom of the filler block to encourage water and moisture to drain freely and cleanly away from the its bottom if moisture or water ever gained access to this area. This also ensures that if water accumulates on the base of the device that the end of the post or filler block would still remain elevated and dry. It also ensures that if any moisture or condensation ever found its way into the concealed area it would drip cleanly from the edge of the block to the base below.
[0090] In addition, vertical tabs creating a surface area formed into the base proximate to the periphery of the elevated portion. This surface aligns within the periphery of the filler block walls so that the inside face of the post cover panels in turn make full contact with the surface of the tabs. Optional screws can be driven through the bottom edge of the cover panels into the vertical tabs. This option may provide further strength to the entire assembly but may be unnecessary.
[0091] Once the base and filler block are situated directly under the post to be repaired, the first section of the post cover panel which resembles a corner section is placed roughly in position at one of the corners of the block and post. The panel is moved closer into the corner of the post until the sharp edges of top horizontal flanges or blades make contact with the post walls above the joint connection. The shapes of the cutting edges of the blades are designed to cut into the side wall of the post from an initial impact of force directed at the corner bend. The force sets the corner of the panel tight against the post where there is no blade. The blade corners are angled (not perpendicular) to the cutting edge of the blade—i.e. the edge of each corner has is at an angle 41 greater than 90 degrees to the cutting edge of the blade flange, preferably greater than 110 degrees, or about 135 degrees. The angled corner edges facilitate the blade to both cut into the post and move tangentially along the side of the post. Once the corner and first part of the blade are set, a direct impact against the post sets the rest of the blade. This does not require excessive force as it only needs to cut about ⅛″ or less into the post to create a mechanical seal. This method is important so as to set the corner of the panel and the blades tightly against the corner of the post before setting the rest of the edges of the blade into the post. The small gap or break in the seal at the “V” cut in the corner of the panel where the flanges do not extend to is later sealed with a small dab of exterior caulking. A reliable long term mechanical seal is thereby been completed. Caulking is used only as it is intended to be used—in small discrete areas rather than as the singular critical element of any exterior sealing system.
[0092] The second cover panel is placed around the opposing corner of the post and care is taken to ensure that one of the vertical edges of the panel is aligned so that as it is driven into final position it slides underneath the overlapping portion of the other cover panel. Sideways force is again applied along the sharp flange ensuring a complete mechanical seal around the post walls and another small dab of caulking is place at the corner gap. The “V” cuts in the top corners of the panels allow the top portion of each side of the cover panel to move freely of one another towards the post wall as they are struck by a hammer. Usually a hammer strike is sufficient to set the blade completely into the post wall. If desired a single screw could also be driven through at mid span of the top edge of the panel.
[0093] Two self drilling screws are driven through the overlapping vertical flanges of the two corner panel members making the entire panel structure a single unitary entity. This itself provides a high degree of lateral impact and torsion strength to the joint between the old post and filler block. In installations where a filler block is employed, two fasteners are screwed through the panels into opposite walls of the upper original post to further secure the panel and post. This ensures that the panels are mechanically connected to both the old post and the filler block so that the glued joint is not the only means of connection.
[0094] Two other fasteners may be screwed through the lower portion of the panels into opposite walls of the filler block (but adjacent to the previous screws) which is in turn connected directly to the support base by fasteners or with an intermediary spacer of metal or high density synthetic material. Incidentally the lateral screws also comply with a requirement under the building code for support posts if they are to meet uplift standards such as for hurricanes.
[0095] The repaired post has both the compression and lateral torsion strength of a new post because of the filler block and the wrapping panel covers. It also has a mechanically sealed joint that will remain dry. The only maintenance required is to inspect the corner dabs of caulking on an annual or bi-annual basis and repair as needed. The post to base to surface connection keeps the post end covered from direct exposure to the elements and pests, such as termites, yet it allows air flow underneath the post bottom to ensure it can dry out easily should water fins its way in. As well, the slim profile of the cover panels closely follows the vertical profile of the original post walls for an improved aesthetic appearance.
[0096] While the illustrated embodiments are adapted to square or rectangular support posts, alternative embodiments of the present invention are adapted to round posts, in which case the cover panels would be semi-cylindrical in overall shape to conform to the external dimensions of a round post.
[0097] 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.
[0098] While the above description and illustrations constitute preferred or alternate embodiments of the present invention, it will be appreciated that numerous variations may be made without departing from the scope of the invention. It is intended that the invention be construed as including all such modifications and alterations. | A post support device that enables a rotted base portion of a wooden support post to be removed in situ and the remaining end of the support post to be secured for regained structural integrity, the device having a base adapted to being attached to the surface, elevation support means in cooperation with the base for supporting the post above the base, at least two cover plates, each adapted to covering a portion of the exterior of the post, and each including an elongate flange facing inward towards the post and generally transverse to the longitudinal axis of the post, said flange portion including a leading cutting edge to enable the flange portion to bite into the surface material of the post upon the application of force to the flange to provide a mechanical seal between the flange and the post, first and second fastening means for securing each cover plate to the post and the base and the elevation support means to the post or the filler block if one is used, respectively. | 4 |
BACKGROUND OF THE INVENTION
The present invention relates to a new and improved construction of floor treating or cleaning machine, hereinafter conveniently referred to as a floor treating machine, such machine being of the type which is supported at the floor or surface to be treated by means of a work disk which is arranged beneath a substantially ring-shaped stop member and releasably coupled with a drive motor.
Floor treating machines of such type are employed for the most varied work, such as, for instance, for polishing, buffing, wiping, scrubbing, sanding, grinding, planing, spraying (with chemical agents) and so forth. These prior art floor treating machines can be basically classified into two groups, namely a first group which is employed for the thorough floor treating work and a second group employed for the maintenance work. Consistent with such subdivision there have been constructed for many years heavy, high-output floor treating machines for the thorough cleaning work and lighter, less powerful machine constructions for the maintenance cleaning work. The most commonly employed models are typically equipped with a work disk having a diameter of about 400 millimeters. Satisfying the requirements which prevail owing to the nature of the work which must be accomplished by resorting to the available equipment heretofore known in the art is extremely uneconomical and for years has only constituted a continual emergency solution. This can be already best appreciated from the aspect of the manufacturer of such equipment, since the production of two different types of machines results in smaller mass production and accordingly higher costs for each unit. Of perhaps even greater significance are the drawbacks considered from the standpoint of the user of such machine, particularly if it is appreciated that the thorough floor cleaning or treatment work -- in contrast to the daily maintenance cleaning work-- occurs at larger time intervals, possibly only once each year, with the result that the more expensive floor treating machine used for the thorough cleaning work is hardly used and therefore uneconomically employed.
Up to the present the manufacturers of such equipment have not been able to find a satisfactory solution for this problem and to offer one to the consumer. One proposal which has been made and commercialized relates to a two-speed machine which is operated at a lower rotational speed during the thorough cleaning work and at a higher rotational speed during the maintenance cleaning work. But with this solution, of course, the machines are more complicated and expensive, without really providing any increased advantages in terms of the more expensive costs of the equipment. In fact it has been found that the higher rotational speed only provides better utilization of the motor output which has been designed on the basis of the thorough cleaning work over a partial range of the maintenance work, not however over the entire range of maintenance work. Apart from the foregoing it has been found to be a further extremely disadvantageous factor that the correct selection of the rotational speed (for the purpose of optimumly utilizing the power of the motor) is extensively dependent upon the skill and "feeling" of the operator and improperly selected rotational speeds can lead to disturbances in the operation of the equipment. Due to these drawbacks preference has generally persisted for the single-speed machines.
Moreover, in an attempt to avoid the necessity of procuring two machines the users of such equipment have acquired bad habits. For instance, it has been found that the workers have used the machine intended for the thorough cleaning or treating work also for the maintenance cleaning work or, however, as more frequently was the case, the maintenance cleaning machine once per year for the heavy or thorough cleaning work and which last-mentioned type of work was much too rigorous for use with the maintenance cleaning machine. In the first case there existed on a daily basis loss in drive energy, whereas in the second case the machine was actually overloaded and thus either immediately or during the course of time broke down.
SUMMARY OF THE INVENTION
Hence, from what has been discussed above it should be apparent that this particular field of technology is still in need of floor treating machine constructions not associated with the drawbacks and limitations discussed above. It is therefore a primary object of the present invention to provide a new and improved construction of floor treating machine which satisfactorily fulfills the existing need in the art and is not associated with the aforementioned drawbacks and limitations of the prior art proposals.
Another and more specific object of the present invention aims at the provision of a floor treating machine which does not constitute a compromise solution as was heretofore the case and is capable of optimumly carrying out both types of work.
Still a further significant object of the present invention relates to an improved floor treating machine which is relatively simple in construction and design, extremely reliable in operation, quite versatile, and specifically adaptable for carrying out both thorough cleaning work as well as maintenance cleaning work.
Now in order to implement these and still further objects of the invention, which will become more readily apparent as the description proceeds, the invention is manifested by the features that there are provided two selectively insertable work disks of different diameter and for each such work disk there is provided a ring-shaped or ring stop. Thus, the given drive power which is dimensioned for the thorough cleaning work by means of the smaller diameter disk is applied to the floor by the larger size work disk with a specific power per unit surface adequate for the maintenance cleaning work and with an enlarged working range, and accordingly, can be fully utilized for the maintenance cleaning work. In contrast to the non-useful increase of the rotational speed undertaken with regard to the aspect of increasing the output, in this case the output or power of the machine is really increased by increasing the useful working range and by daily usefully employing the machine expenditure predicated upon the requirements of the thorough or primary cleaning work. A comparison with the two-speed machine has shown that additionally the floor treating machine of this development, when used in both of its useful stages, not only is properly dimensioned from the standpoint of the power requirements but additionally also with respect to its construction. Thus, while the heretofore known reversible machines when operating in the higher rotational speed range function with an overdimensioned transmission or gearing, the requirements which are placed upon the gearing or transmission of the machine of this development are approximately the same both for the thorough cleaning work as well as also for the maintenance cleaning work. Apart from the economies regarding energy which are realized the machine of the invention also from its constructional standpoint is devoid of any compromise solutions. This means that the apparent advantages which are gained by both the user as well as the manufacturer are not overpaid. The manufacturer can adequately satisfy the requirements with a single type of machine and therefore can produce such machines less expensively on a mass-production basis. On the other hand, the users of such equipment obtain two machines in one merely for the small additional cost of providing an additional work disk and the therewith associated ring stop.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention will be better understood and objects other than those set forth above, will become apparent when consideration is given to the following detailed description thereof. Such description makes reference to the annexed drawings wherein:
FIG. 1 is a perspective view of a floor treating machine employed for the primary or thorough floor cleaning work;
FIG. 2 illustrates the same machine portrayed in FIG. 1 but equipped with structure for carrying out the maintenance cleaning work; and
FIG. 3 illustrates the machine of FIG. 2 in a partially exploded view in order to reveal internal structure.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Describing now the drawings, according to the exemplary embodiment of floor treating machine shown in FIG. 1 the entire floor cleaning machine, conveniently designated by reference numeral 1, rests upon a work disk 2 which is conveniently driven by a suitable drive motor 3 through the agency of an appropriate detachable coupling which is not particularly visible in the showing of the drawing. The work disk 2 is detachably connected by means of the detachable or releasable coupling to the drive motor 3 in conventional manner which does not constitute part of the invention. As to the work disk 2, and as best seen by referrring to FIG. 1, such comprises a marginal edge or rim 2' from which upwardly extends a central hood portion 2a. At the underside of the marginal edge or rim 2' of the work disk 2 there is supported a suitable floor treating element 2b. Above the marginal edge or rim 2' of the work disk 2 there is located a stop or check ring 4 which is secured to a substantially plate-shaped wall portion 5 of the machine housing 5'.
As best seen by referring to FIGS. 2 and 3, instead of using the work disk 2 it is possible with the aid of the previously mentioned detachable coupling to insert a work disk 6 which, in contrast to the work disk 2, possesses a wider marginal edge 6' which protrudes past the stop ring 4 and accordingly has a larger diameter. In all other respects the work disks 2 and 6 may be essentially of the same construction. A substantially pot-shaped ring stop, designated in its entirety by reference character 7, and associated with this work disk 6, has a stop or check ring 8 which is accommodated in its diameter to the larger size diameter work disk 6, and which stop ring 8 in the working position of the ring stop 7 (FIG. 2) is located around the stop ring 4 above the edge 6' of the work disk 6. The end wall 9 of the ring stop or stop member 7 bears against the wall 5 of the machine housing 5' and the stop rings 4 and 8 are centered relative to one another by means of centering projections 10 (FIG. 3) and 11 (FIG. 2) respectively, arranged at the end wall 9 and which engage about the outside of the stop ring 4. The end wall 9 is equipped with a recess 12 for piercingly receiving therethrough and accommodating therein parts of the machine housing which protrude past the wall 5. This end wall furthermore carries plug-in or insertable pins 13 or equivalent structure which can positively engage with sleeves 14 (FIG. 3) formed of rubber or a suitable plastic, and which sleeves are secured at the wall 5 of the machine housing 5'. In this way it is possible to securely hold in its working position, as shown in FIG. 2, the ring stop 7.
The output of the drive motor 3 is dimensioned such that for the primary or thorough cleaning work, i.e. for the heavier cleaning work there is available the required specific power or output related to the surface of the smaller work disk 2. If the smaller work disk 2 is exchanged for the larger work disk 6, then, the specific output drops to a valve which is adequate for the maintenance work, and the given motor output is completely usefully applied to the floor over a larger working surface. Consequently, the motor output calculated for the thorough cleaning work is transformed during the maintenance cleaning work into an hourly output which can be considerably greater than that of a maintenance cleaning machine which is only provided for use for this purpose. Consequently, the user of the equipment has a two-fold gain since he can get by with a single machine, which beneficially during the daily maintenance work is capable of reducing the working times and therewith the operating costs of the worker which are forever always increasing more and more.
While there is shown and described present preferred embodiments of the invention, it is to be distinctly understood that the invention is not limited thereto but may be otherwise variously embodied and practiced within the scope of the following claims | A floor treating machine supported at the floor or surface to be treated by means of a work disk arranged beneath a substantially ring-shaped stop member, the work disk being detachably coupled with a drive motor. There are provided two selectively insertable work disks of different diamter and a ring-shaped stop member is provided for each such work disk. | 0 |
FIELD OF THE INVENTION
This invention is directed to heavy construction attachment systems, in particular, to a system incorporating major disassembable units and to the units of the system.
BACKGROUND TO THE INVENTION
In the construction industry, concrete foundations are commonly manufactured by using formwork into which concrete is poured. This formwork usually consists of re-usable wood and aluminum composite struts and joists which provide a supporting crib-work or lattice for the actual sheathing members onto which the concrete is poured. The sheathing frequently consists of plain or paper faced plywood members. Thus, a substantial plywood sheathing sheet for example 3/4 inch ply, having a replaceable paper liner as the casting surface, is usually nailed to an underlying supporting joist having an inset nailing strip. After the concrete has set, the underlying formwork lattice and plywood is removed. Frequently the plywood has to be torn down, owing to the entrainment of the attachment nails into the concrete. Similarly, the face of the plywood may be penetrated by the concrete and become damaged. The wood nailing strips of the supporting laticework will become damaged over time due to repeated re-use and will have to be replaced. Considerable expenditures in material and labour costs are therefore involved, and valuable resources are used up.
The present method of manufacturing concrete foundations also has a drawback in that seam outlines of the 4×8 foot sheathing sheets, caused by misalignments, gaps and penetrating cement flashings must be ground away where a smooth finished surface is required.
The use of hook and loop elements for the purpose of joining flexible elements is not new. The garment and footwear industries have for many years employed a particular hook and loop type attachment material, commonly referred to by the trade mark VELCRO, for securing the adjacent surfaces of clothing and footwear. However, this material is limited both by the presently available widths, which do not exceed four inches, and by the maximum anchoring force developed by the plastic hook elements. Furthermore, prior usage appears to have been concentrated on the application of this type of fastener in areas where a peeling, wave-like relative movement can be used to attach and detach a pair of complementary hook and loop surfaces, as when opening a garment or a shoe flap or on the installation of decorative, non-structural panels such as shown in Wilson, U.S. Pat. No. 4,744,189 issued May 17, 1988 or room dividers such as shown in Curatolo, U.S. Pat. No. 4,090,335 issued May 23, 1978.
SUMMARY OF THE INVENTION
The present invention provides a building construction having a plurality of rigid standard components for assembly in layered, substantially planer facing relation, a first such standard component manufactured in standard lengths with a first part of a hook and loop fastening system along a surface of the standard component; a second such standard component having a second part of a hook and loop fastening system of complementary attachability to the first part along at least one surface of the second component, so that such components can be cut and fit as necessary in the building construction and engaged with each other by face to face detachable engagement between the first and second parts of the hook and lopp fastening system.
In one embodiment the building component portions may be positioned in substantially horizontally oriented, substantially planar relation.
In a further embodiment the building component portions may be positioned in inclined oriented relation, such as component parts of a partition wall.
In an alternative embodiment the construction may be temporary, having a plurality of layers, with attachment components secured in releasable joining connection between more than one pair of opposed interfaces of the construction layers.
The present invention discloses in one embodiment a system for manufacturing concrete structures in which re-usable hook and loop area fasteners are secured to component portions and used to attach formwork components in face-to-face mutually adherent, detachable relation.
In this embodiment one of the layers on which the formwork is erected may become embeded in and left with the concrete for later use in attaching finishing details such as surface decoration, rugs or wall paper.
The invention further provides an attachment system having releasable connecting elements for adhering to concrete, to enable the provision of removable and substitutable surface finish members in attached relation by way of the connecting elements to the concrete structure. Such surfaces may be walls, floors and/or ceilings.
The invention further provides a building system wherein a layer of first connecting elements is secured in permanently adhered relation to a first access face of a structure, to form an integral part thereof, for use in securing a second reverse face of a complementary structure in secured relation at the interface therewith, having a layer of second fastening elements located at the interface in engaging relation with the first layer of first elements.
Thus, a carpet or other floor covering having suitable fastening elements on the undersurface, or ceiling panels or tiles having appropriate fastening elements on the upper surface may be readily, detachably secured to an appropriate structure. Similarly, wall surfaces for partitions and the like can be attached to a stud system. Also, the elements of the stud system may incorporate such complementary layered fastening elements.
In one embodiment a lattice of supporting members includes at least a first face of a first member in pressing, adjoined relation with a second face of a second member, each member having secured thereto one component portion of a two component connecting means, to form a connecting interface between the members. Such a connection may be used in concrete formwork, or in a permanent floor joist and sub-floor construction, as well as in wall constructions.
In another embodiment, a structural member is provided with a surface connecting means component part in bonded relation to a first surface portion thereof, for use in attaching a second member having a second surface with a complementary surface connecting means in bonded relation thereto, for joinder of the first and the second members.
In another embodiment a structural member having a first surface with a layer of surface connecting means first component parts mounted to a backing sheet and bonded to the member is provided with a removable protective cover secured thereover in protective relation, the protective cover including on one face thereof a layer of surface connecting means second components complementary to the first components of the connecting means, to permit the attachment and removal of the protective cover and exposure of the surface layer of connecting means first components. Such an embodiment may comprise a floor and sub-floor construction, wherein the protective cover remains in place during the completion of construction, so as to protect the surface connecting means therebeneath. Subsequently, a carpet or other covering may be substituted wherein the protected underlying connecting components are utilized to removably secure the covering to the sub-floor.
In general, the area fastening elements of complementary hooks and loops are of synthetic material, formulated in layers attached to backing sheets to facilitate area coverage by way of the attachment means, so as to develop the requisite attachment strength.
BRIEF DESCRIPTION OF THE DRAWINGS
Certain embodiments of the invention are described, without limiting the invention thereto, reference being made to the accompanying drawings, wherein;
FIG. 1 is a general view of a concrete formwork system in accordance with the present invention, in partially exploded relation;
FIG. 2 is a general view of a structural floor system in accordance with the present invention;
FIGS. 3 and 4 are general views of structural elements incorporating component connecting means in accordance with the invention;
FIG. 5 is a sideview section of a poured ceiling or roof incorporating one element of a connecting means combination in installed relation therewith.
FIG. 6 is a view similar to FIG. 5, the ceiling incorporating the complementary elements of the connecting means combination.
FIG. 7 is a general view in exploded relation showing the elements of a portion of a partition wall embodying the invention.
DETAILED DESCRIPTION OF THE INVENTION
In the making of the present invention it will be appreciated that certain inherent deficiencies and limitations of presently available hook and loop fasteners, such as the presently limited width of four inches in the VELCRO product, and the present upper limit on its gross developed joint strength can be overcome by the provision of wide width sheets of the respective hook and loop elements, the development of elements of improved characteristics and the adoption of improved manufacturing processes for the fasteners. An aspect of the components presented is the integration of a hook and loop fastening system into the surfaces of the products. What is described is an incorporation of this system directly into the elements comprising the building system. This aspect is required in order to provide the necessary flexibility of attachment when products are to be transported to the site as standard components or cut and fit on site for assembly into a building.
In addition, the invention presented in this application as well as previous application No. 148,711 filed Jan. 26, 1988 ANCHOR BOARD SYSTEM are not fastening products per se but rather are new designs of conventional building materials.
Referring to FIG. 1, a concrete formwork assembly 10 comprises a number of supporting struts 12 carrying beams 14 across which are laid joists 16, to which sheathing sheets 18 are secured.
A covering 41 overlays the gaps or joints 39 between adjoining sheathing sheets 18. At the interfaces 11, 22, 24 between the respective rigid components 14, 16, 18 area fastening elements comprising loops 27 and hooks 29 are located, to attach the respective components in securely anchored relation.
The covering 41 also utilizes area fastening elements comprising loops 27 and hooks 29 to secure it to the sheathing sheets 18.
Referring to FIG. 2, a portion 30 of a floor construction is shown. Illustrated are fabricated joists 32, each comprising a pair of opposed flanges 34, 36 having a web 38 secured therebetween. Such joists 32 can be of extruded light alloy such as aluminum, or fabricated of metal, or of wood and plywood as indicated.
The ends of joists 32 usually are supported by peripheral basement walls (not shown).
A subfloor comprising panels 40 is supported by joists 32. At the interface contact areas 46 and 47 are located area fastening elements secured to the respective components comprising loops 27 and hooks 29, to hold the respective components in mutually anchored relation. A flexible, protective cover sheet 50 overlies the upper surface of floor panels 40, being arranged to cover the floor panel intermediate gaps or joints 39.
During the erection of a building, sheet 50 may comprise a protective over-flooring element, to safeguard the underlying, upwardly extending hook portions 29 against damage from above. Once the building is erected and the finishing work completed, the protective sheet 50 can be removed and 4×8 sheets of plywood for a flooring system having a complementary loop layer on the underface thereof or a covering carpet with a looped underface, as disclosed in my copending application Ser. No. 136,953 can be installed.
FIG. 3 shows a substantially rigid panel 50 having a layer of loop elements 27 on one face thereof. This panel may comprise a finished surface element, which can be attached to installed hook elements 29 of a construction.
In the case of a poured ceiling surface, as illustrated in FIGS. 5 and 6, respective surface area attachment elements 54, 56 can be secured in situ at the time of pouring the concrete ceiling, or subsequently applied thereto. The enhanced utility achieved in making the surface area elements 54 or 56 as part of the formwork illustrated in FIG. 1, by appropriate adaptations, can be readily appreciated. Thus, in the case of the ceiling embodiment referred to in the FIG. 1 arrangement, a covering 41 may be either releasable so that it does not attach to the concrete or it may include upwardly extending loops or hooks, so as to bond the covering 41 to the undersurface of a ceiling that is poured thereover. It will be understood that the undersurface of covering 41 also is provided with hooks or loops, the selection of loops or hooks being appropriate to the fastening elements incorporated with the finish ceiling surface to be suspended therefrom. Further, fastening elements complementary to the selected elements of the undersurface of covering 41 will be secured to the upper surface of sheathing sheets 18, to enable detachable attachment of covering 41 to sheets 18, to facilitate initial assembly, and subsequent disassembly of the formwork.
FIG. 4 illustrates a panel 60 having a layer of loop elements 27 and hook elements 29 thereon, for use as an intermediate construction.
In operation, referring first to FIG. 1, a supporting grill work of elements 12, 14, 16 is erected. The presence at the respective interface areas of the hook/loop area attachments permits assembly without nailing or other auxiliary fastening steps. Similarly, the sheathing sheets 18 ar readily positioned in place and secured by the weight of the sheeting, together with the temporary application of downward force thereon, to engage the respective loop and hook elements 27, 29.
The barrier sheet 41 protects the upper surface of the sheathing sheets 18 so that liquid concrete cannot penetrate between adjacent sheets 18. This minimizes the need for subsequent joist-flash grinding. In the case of the sheathing sheet members 18, it is contemplated that they may be fabricated of materials other than plywood, such as aluminum composites having a foam core, in order to reduce the weight of these members while maintaining adequate structural strength and rigidity.
The barrier sheet 41 may have a treated upper surface thereon, to facilitate bonding with the concrete when it is poured, or a surface barrier layer which precludes such bonding. Also, the upper surface of sheet 41 may have recesses or protrusions, to facilitate in-situ bonding to the poured concrete.
In FIG. 2, suitable floor joists such as the illustrated prefabricated joists are installed at the requisite intervals. The joists 32 may also incorporate area attachment elements in accordance with the present invention at their end lower surfaces to facilitate their installation. The sub-floor panels 40 are then positioned in place where temporary downward force will engage the interface fastener elements, loops 27 and hooks 29.
A protective flexible sheeting 50 then is laid over the sub-floor, so as to cover the intermediate joists 39. The purpose of the sheeting 50 is to protect hook elements 29 of the subfloor panels 40. Once construction activity, such as that of the allied trades, electricians, plumbers, carpenters is completed, a carpet having a looped undersurface in accordance with my copending application Ser. No. 136,953 can be substituted for the sheeting 50.
In dissassembling the subject system it will be understood that, owing to the potentially large securing forces that can be generated between the interface attachment hook and loop means, the use of auxiliary mechanisms, such as pry bars or pulling mechanisms may be required.
Referring to FIG. 7 a portion of a partition wall assembly 70 is shown. A sill piece 72 of U-section, having fastening elements 73 therein receives a stud member 74 in inserted relation. An end under-face of portion 75 of stud member 74 has fastening elements 77 thereon, to engage the fastening elements 73 of sill piece 72. The side portions 78 of stud member 74 have the outer faces thereof covered or at least partially covered with fastening elements 77, to which the elements 73 of sheet 79 can adhere. In use a partition wall can be readily and rapidly assembled to provide a partition wall of adequate strength, yet which can be readily disassembled. The sill piece 72 may also be provided with attachment elements 73 or 77 on the underface thereof. The partition wall elements 72 and 74 are generally of rolled metal, of thin section, similar to the metal studs and sills presently used with nailing constructions.
It will be understood that the foregoing disclosed embodiments are illustrative of the invention and modifications thereto can be made, within the scope of the claims appended hereto. | Re-attachable structural assemblies incorporating complementary area fastening elements comprising hook and loop elements over extended rigid contact surfaces between structural members of an assembly are disclosed for use in the construction industry in relation to: temporary formwork for casting concrete; precast concrete components for permanent installation of finished surfaces; and, fabricated floor and wall systems including joists, sub-floors, and floor covering surface units. The use of synthetic hook and loop attachment systems affords significant savings in time, labor, and frequently in materials, particularly in the temporary formwork application. | 4 |
BACKGROUND OF THE INVENTION
This invention generally relates to a rodless cylinder apparatus which permits movement of a piston within a cylinder tube without employing a piston rod, and more particularly to a rodless cylinder apparatus which is capable of positioning the piston at a desired position in its stroke within the cylinder.
As most typically represented by an air cylinder, cylinders are widely used as an actuator for positioning various parts and jigs placed on a table at a selected or desired position. In general, each of the cylinders comprise a cylinder tube, a piston provided within the cylinder tube for reciprocating movement therealong, and a piston rod for transmitting the reciprocating movement of the piston to an external element.
It is known that a cylinder having a piston rod requires a cylinder tube which is at least as long as the stroke over which the piston rod makes a reciprocating movement. This presents a problem that the longer the stroke length is, the bigger space is needed for installation of the cylinder.
Because of the above-noted problem, a rodless cylinder has become more popular in recent years which allows a piston to make a reciprocating movement without employing a piston rod. Having no piston rod, such rodless cylinder can be installed in much smaller space as compared with the traditional cylinders having a piston rod.
FIGS. 7, 8 and 9 illustrate an example of the prior art rodless cylinder in trigonometry: FIG. 7 is a plan view of the rodless cylinder as viewed in the Z-axis direction; FIG. 8 is a side-elevational view of the rodless cylinder as viewed in the Y-axis direction, and FIG. 9 is a side-elevational view of the rodless cylinder as viewed in the X-axis direction (that is, the piston movement direction). In FIGS. 8 and 9, the rodless cylinder is shown partly in cross section.
A cylinder tube 1a of the cylinder is in a rectangular parallelepiped shape, and it has a hollow interior portion that serves as a guide along which piston 2a makes an reciprocating movement. The cylinder tube 1a also has a longitudinal gap of a given width which extends in the axial direction of the tube 1a along the entire stroke, namely, length of the reciprocating movement of the piston 2a, in order to allow a piston yoke 2b to project outwardly of the tube 1a and to move freely along the tube 1a. Because of the gap, the cylinder tube 1a is generally C-shaped in cross section as viewed in the piston movement direction (X-axis direction). The gap in the cylinder tube 1a is sealed by a sealing belt 5 for fluid tightness in the tube 1a.
The piston 2a is composed of right and left pistons 2a each of which is a cylindrical column that corresponds in cross-sectional shape to the hollow interior portion of the cylinder tube 1a. The piston yoke 2b has an upper portion projecting outwardly of the cylinder tube 1a and terminating in a support portion for supporting thereon a table or article carrier 6. Within the cylinder tube 1a, the pistons 2a are coupled to the left and right side of the yoke 2b respectively. A piston packing 3 is provided on and around the outer circumferential surface of the piston 2a. In the piston yoke 2b, a slot 4 is provided through which the sealing belt 5 extends. The sealing belt 5 is movable relative to the yoke 2b along the slot 4, so that the yoke 2b is capable of making a free reciprocating movement with the piston 2a while fluid tightness in the tube 1a is maintained by means of the sealing belt 5.
The table 6 has a channel-shaped cross section and mounted on the upper support portion of the piston yoke 2b. The piston yoke 2b has in its upper surface a guide channel for a dustproof belt 7. The belt 7 is slidable along the guide channel of the piston yoke 2b between the table 6 and piston yoke 2b. The belt pressing member 8 is rotatably mounted about a shaft 9 and normally urged by a spring 10 for pressing the dustproof belt 7 against a wall defining the gap of the cylinder tube 1a.
End caps 11L and 11R are provided at opposite ends of the cylinder tube 1a and have air supplying tubes 11a and 11b, respectively, for supplying pressurized air into the cylinder tube 1a. Belt covers 12L and 12R are provided for fastening the dustproof belt 7 and sealing belt 5 at the opposite ends of the cylinder tube 1a. The end cap 11L, cylinder tube 1a, sealing belt 5 and left piston 2a together form a left-side chamber space, while the end cap 11R, cylinder tube 1a, sealing belt 5 and right piston 2a together form a right-side chamber space.
When a predetermined amount of pressurized air is supplied through the air supplying tube 11a into the left-side chamber space, air pressure in the left-side chamber space is increased so as to move the left piston 2a and piston yoke 2b together to the right. Conversely, when a predetermined amount of pressurized air is supplied through the air supplying tube 11b into the right-side chamber space, air pressure in the right-side chamber space is increased so as to move the right piston 2a and piston yoke 2b together to the left. This causes the table 6 to make a reciprocating movement along the length of the cylinder tube 1a.
Although not shown in the drawings, a magnet is provided near the outer periphery of a cylindrical portion of the piston yoke 2b and a proximity switch is provided on the side surface of the cylinder tube 1a. With such magnet and proximity switch, the stroke end of the cylinder can be detected and the reciprocating movement of the piston 2a can be controlled as desired.
The prior art rodless cylinder 1 shows relatively strong load-resistance characteristics against a vertical (Z-axis direction) load moment that is applied to the piston 2a via the table 6. But, the prior art rodless cylinder 1 shows relatively weak load-resistance characteristics against a vertical load that is applied to the piston yoke 2b from the table 6, because, as previously noted, the cylinder 1 has the gap extending along the entire length of the piston movement (X-axis direction) to allow the piston yoke 2b to project outwardly of the tube 1a and to move freely along the tube 1a.
In particular, the rodless cylinder 1 shows extremely weak characteristics against a laterally bending moment that is applied from the center of the piston yoke 2b in the Y-axis direction. The laterally bending moment is such a moment that will rotate the piston yoke 2b in the Y-Z plane. Hereinafter, a moment that will rotate the piston yoke 2b in the X-Z plane will be referred to as a bending moment, and a moment that will rotate the piston yoke 2b in the X-Y plane will be referred to as a twisting moment.
Accordingly, in the case where a robot or the like is constructed using a plurality of the prior art rodless cylinders 1 in such a manner that it is capable of making controlled free movements in two or three-dimentional coordinates space, the total weight of parts and jigs which can safely be placed on the table 6 will be undesirably limited because of the above-mentioned various moments produced due to the weight of the rodless cylinder 1 itself. This makes the robot or the like extremely impractical.
In addition, the prior art rodless cylinder 1 can only detect the stroke end of the piston 2a by means of the magnet incorporated in the piston 2a and the proximity switch, but it can not detect a current position of the stroke of the piston 2a, and so it can not achieve such a function to stop the piston 2a (i.e., table 6) accurately at a desired position (intermediate point) in the stroke. Although the piston 2a can be stopped at an intermediate position in the stroke by applying the equal air pressure to both sides of the piston 2a because air contact surfaces on both sides of the piston 2a are equal in area, stop position of the piston 2a can not be accurately controlled. In particular, in the case where plurality of the rodless cylinders 1 are employed to form two or three-dimensional space and the movement direction of the piston 2a happens to coincide with the gravity direction, it will be extremely difficult to stop the piston 2a (and hence table 6) accurately at a desired intermediate position in the stroke.
SUMMARY OF THE INVENTION
It is therefore a primary object of the present invention to provide a rodless cylinder apparatus which is highly rigid against heavy loads and is also capable of positioning a piston accurately at any desired position in its stroke.
A rodless cylinder apparatus according to the present invention comprises: a rodless cylinder including a cylinder tube, a piston movable within said cylinder tube and a connecting member connected to said piston, said cylinder tube having a longitudinal gap extending in an axial direction thereof, through which said connecting member projects outwardly of the cylinder so as to connect the carrier with said piston and is also allowed to move along said cylinder tube in such a manner that the carrier is moved together with said piston; at least a first rod fixed relative to said cylinder tube to extend in parallel with a direction in which said piston moves within said cylinder tube, said rod being provided in such a manner to support at least a part of weight of the carrier applied to said rodless cylinder; and a sensor having a moving member movable along said rod as said piston moves within said cylinder tube, for detecting a current position of said piston in accordance with relative positional relation between the moving member and the rod.
In general, the rodless cylinder comprises at least a cylinder tube and a piston but no piston rod that is indispensable in the conventional cylinders. The article carrier is connected via the connecting member to the piston and is movable with parts and jigs placed thereon as the piston moves along the cylinder tube. In the prior art rodless cylinder, weight of the table is applied to the piston yoke and piston.
In the present invention, the rod is fixed relative to the cylinder tube in such a manner that the rod extends in parallel with the direction in which the piston and hence the carrier moves along the cylinder tube. The sensor is provided to be movable along the rod as the piston moves for detecting the current position of the piston.
Since the rod is arranged to receive at least a part of weight of the carrier, the rod serves as a beam for supporting the carrier. Accordingly, much stronger load-resistance characteristics can be obtained as compared with the prior art rodless cylinders where weight of the carrier is received only by the piston yoke or connecting member, piston and cylinder tube. Only one such rod may be sufficient to enhance the load-resistance characteristics, but when higher performance is desired against a lateral bending moment, two such rods may be provided.
As noted above, the present invention can remarkably enhance load-resistance characteristics by providing the rod in such a manner to support weight of the carrier. Further, since the sensor is constructed using this rod, there will be achieved a superior advantage that the piston can be positioned to stop accurately at a desired position in its stroke.
Now, the preferred embodiment of the present invention will be described in greater detail with reference to the attached drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
In the drawings:
FIG. 1 is a top plan view of a rodless cylinder apparatus according to an embodiment of the present invention, as viewed in the Z-axis direction;
FIG. 2 is a side elevational view of the rodless cylinder apparatus as viewed in the Y-axis direction;
FIG. 3 is an end view of the rodless cylinder apparatus as viewed in the X-axis direction;
FIG. 4 is a cross-sectional view illustrating in detail the construction of a sensor employed in the rodless cylinder apparatus of the present invention;
FIG. 5 is a block diagram showing an example circuitry of phase difference detector which is arranged to obtain a phase difference φ from the sensor unit of FIG. 4 in digital amount;
FIG. 6 is a cross-sectional view schematically showing the construction of a brake employed in the rodless cylinder apparatus of the present invention;
FIG. 7 is a top plan view of an example of a prior art rodless cylinder apparatus as viewed in the Z-axis direction;
FIG. 8 is a side elevational view of the prior art rodless cylinder apparatus as viewed in the Y-axis direction, and
FIG. 9 is an end view of the prior art rodless cylinder apparatus as viewed in the X-axis direction.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
FIG. 1 shows in trigonometry a rodless cylinder apparatus according to an embodiment of the present invention. More particularly, FIG. 1 corresponds to FIG. 7 and is a top plan view of the rodless cylinder apparatus as viewed in the Z-axis direction. It is also to be noted that FIG. 2 corresponds to FIG. 8 and is a side elevational view of the rodless cylinder apparatus of FIG. 1 as viewed in the Y-axis direction, and FIG. 3 corresponds to FIG. 9 and is an end elevational view of the rodless cylinder apparatus of FIG. 1 as viewed in the X-axis direction.
The rodless cylinder apparatus generally comprises a conventional-type rodless cylinder 1, securing plates 21L, 21R, a brake rod 22, a sensor rod 23, brake 24 and sensor 25. The rodless cylinder 1 is identical in construction with the cylinder previously discussed in connection with FIGS. 7 to 9. The table 6a employed in this embodiment is larger in width than the conventional table 6 and extends to cover the brake 24 and sensor 25 as viewed from above (in the Z-axis direction). The table 6a is mechanically coupled to the brake 24 and sensor 25 by welding, screwing or any other suitable means.
The securing plates 21L, 21R, each of which comprises an iron plate having a thickness of 25 mm, are fixed to a bed (not shown) or the like by welding, bolting or any other suitable means, and they serve to mechanically secure the brake rod 22, sensor rod 23 and rodless cylinder 1.
The brake rod 22 and sensor rod 23, each of which comprises an iron column having a diameter of 36 mm, are mechanically secured to the securing plates 21L, 21R by welding or bolt-nut connection. The rodless cylinder 1 may be secured to the securing plates 21L, 21R in similar manner.
The brake 24 has at its opposite ends bearings 24L, 24R by means of which it is slidable on and along the brake rod 22, and the brake 24 brakes the table 6a so as to stop it at a selected or desired stroke position. Likewise, the sensor 25 has at its opposite ends bearings 25L, 25R by means of which it is slidable on and along the brake rod 22, and the sensor 25 detects a current stroke position in absolute manner. Detailed construction of the brake 24 and sensor 25 will be described later.
The brake 24 and sensor 25 are both mechanically secured to the table 6a. This allows the table 6a to freely slide along the brake rod 22 and sensor rod 23 between the opposed securing plate 21L, 21R, via these brake 24 and sensor 25. So, the table 6a can make a reciprocating movement linearly in the X-axis direction.
The brake rod 22 and sensor rod 23 mechanically fixed to the securing plates 21L, 21R constitute fixed beams in the cylinder 1, in such a manner that the entire weight of the table 6a is received by the brake rod 22 and sensor rod 23 as the fixed beam. Thus, the rodless cylinder 1 functions solely as an actuator for moving the table 6a in the piston movement direction (X-axis direction) and is not affected by any load. Consequently, as compared with the conventional rodless cylinder apparatus, the rodless cylinder apparatus of this invention shows dramatically increased strength against various moments such as the bending, lateral bending and twisting moments.
The rodless cylinder apparatus of this invention is primarily characterized in that movement in the X-axis direction of the table 6a is controlled by the rodless cylinder 1, a current position of the table 6a is detected by the sensor 25, and the table 6a is stopped at a desired position by the brake 24 in accordance with the detection of its current position.
To stop the table 6a at a desired position by the brake 24, the present invention employs the positioning control technique as disclosed in Japanese Patent Laid-open Publication No. Sho 59-117902. Only outline of the positioning control technique is given herein since it is described in detail in the publication. The positioning control technique is characterized by having a learning control function which permits precise positioning of the table 6a in consideration of the speed or acceleration of the piston 2a (table 6a) or overrun amount corresponding thereto. The positioning control technique performs a positioning control by predicting overrun amount corresponding to the moving speed of the piston 2a, as well as predicting overrun amount in consideration of the acceleration because the initiation time of movement is relatively strongly affected by the acceleration. That is, predicted overrun amount is determined in consideration of both the moving speed and the acceleration of the piston 2a relative to the cylinder tube 1a, and the current position data from the sensor 25 or positioning target value (established value of movement amount) is changed in such a manner that compensation is made in accordance with the predicted overrun amount determined, and movement amount of the piston 2a is controlled on the basis of comparison with the changed position data or positioning target value.
FIG. 4 illustrates in detail the construction of the sensor 25 which is an absolute-type position sensor in the form of an induction-type, phase shift-type position sensor. Simplified description on this position sensor will be given herein since detail of it can be known from such as Japanese Utility Model Laid-open Publication Nos. Sho 57-134622, Sho 57-151503, Sho 57-135917, Sho 58-136718 or Sho 59-175105.
The sensor 25 serves to detect a linear position of the sensor rod 23 and comprises a coil assembly 41 and the sensor rod 23. The coil assembly 41 includes four primary coils 1A, 1C, 1B, 1D that are wound around the sensor rod 23 and spaced from each other in the axial direction of the rod 23 at a predetermined interval, and four secondary coils 2A, 2C, 2B, 2D that are disposed in corresponding relation to primary coils 1A, 1C, 1B, 1D. The coil assembly 41 is fixedly accommodated in the casing 42 in such a manner that its internal cylindrical space is concentrical with the sensor rod 23.
The sensor rod 23 comprises a magnetic calibration section 43 formed of a magnetic section 45, and annular non-magnetic sections 46 each of a predetermined width. The annular non-magnetic sections 46 are disposed around the sensor rod 23 and spaced apart from each other in the axial direction of the rod 23 in such a manner that, on the surface of the rod 23, the magnetic section 45 and any of the non-magnetic sections 46 appear in alternating fashion. The magnetic section 45 and non-magnetic sections 46 may be made of any suitable materials as long as they are able to impart a change in magnetic resistance or reluctance to a magnetic circuit produced in the coil assembly 41. For example, the non-magnetic sections 46 may be made of any non-magnetic material or air. Alternatively, the magnetic section 45 and non-magnetic sections 46 having different permeabilities may be formed in alternating fashion, by performing a laser burning on the iron sensor rod 23 to change the magnetic characteristics of the rod 23.
It is assumed here that each of the coils has a length (i.e., length in the axial direction of the rod 23) of P/2 (P is an optional value), and one pitch interval in the row of the magnetic section 45 and non-magnetic sections 46 is P. In this case, the magnetic section 45 and non-magnetic sections 46 may be of an equal length of P/2 or may be of different lengths.
According to this embodiment, the coil assembly 41 is constructed so as to work at four phases which are, for the sake of convenience, denoted in the drawings by reference characters A, C, B and D.
Positional relationship between the sensor rod 23 and coil assembly 41 is such that reluctances produced in the four phases A, C, B, D in correspondence with the position of the sensor rod 23 are different or shifted by 90° from one another in correspondence with the position of the sensor rod 23. For example, when the phase A is a cosine phase, the phase C will be a minus cosine phase, the phase B will be a sine phase, and the phase D will be a minus sine phase.
In the example shown in FIG. 4, pairs of the primary coils 1A, 1B, 1C, 1D and secondary coils 2A, 2C, 2B, 2D are provided respectively for the phases A, C, B, D. The secondary coils 2A, 2C, 2B, 2D are wound outwardly of the corresponding primary coils 1A, 1B, 1C, 1D.
In the illustrated example, each of the primary coils 1A, 1B, 1C, 1D and secondary coils 2A, 2C, 2B, 2D has, as previously noted, a length of P/2. Further, the coils 1A, 2A of the phase A are provided adjacent to the coils 1C, 2C of the phase C, while the coils 1B, 2B of phase B are provided adjacent to the coils 1D, 2D of the phase D. Further, it is assumed that the interval between the coils of the phase A and the coils of the phase B and interval between the coils of the phase C and the coils of the phase D is P (n±1/4) (n is an optional natural value).
Thus, in accordance with relative linear displacement between the sensor rod 23 and coil assembly 41, reluctance at each of the phases A-D in the magnetic circuit periodically changes in a cycle corresponding to the interval P, with the phases A-D being different or phase shifted by 90° from each other. More specifically, the phases A and C are different by 180° from each other, and the phases B and D are also different by 180° from each other.
Connection among the primary coils 1A, 1C, 1B, 1D and secondary coils 2A, 2C, 2B, 2D is shown in FIG. 5. Namely, the connection is such that the primary coils 1A, 1C of the phases A and C are excited at the same phase by sine wave signal sine ωt, and the outputs of the secondary coils 2A, 2C are added together at opposite phase. Similarly, the primary coils 1B, 1D of the phases B and D are excited at the same phase by cosine wave signal cos ωt, and the outputs of the secondary coils 2A, 2C, 2B, 2D are added together at opposite phase. The outputs of the secondary coils 2A, 2C, 2B, 2D are finally added together and provided as an output signal Y to the phase difference detecting circuitry 30.
This output signal Y is such a signal that has been produced from phase-shifting the reference AC signals (sine ωt and cos ωt) by an phase angle φ corresponding to relative linear position between the magnetic section 45 of the sensor rod 23 and the sensor 25. That is because the reluctances at the phases A-D are different by 90° from one another, and also the exciting signal for one pair of the phases A and D is different by 90° in electrical phase from that for the other pair of the phases B and D. Therefore, the output signal can be expressed as:
Y=K sin (ωt+φ),
in which K is a constant.
Phase φ of the reluctance change is proportional to the linear position of the magnetic portion 45 in accordance with a predetermined proportion coefficient (or a predetermined proportion function), and thus the linear position can be detected by measuring phase shift amount φ in the output signal Y from the reference signal sine ωt or cos ωt. However, if the phase shift amount φ is a full 2π, the linear position will correspond to the above-noted distance P. That is, by measuring the electrical phase shift amount φ, absolute linear positions within the distance P can be precisely detected with considerably high resolution.
It should be understood that the magnetic calibration section 43 of the sensor rod 23 may be made of other materials than magnetic and non-magnetic materials. For example, the magnetic calibration section 43 may comprise combination of materials having different electric conductivities. For example, the magnetic calibration section 43 may comprise a combination of high conductivity material such as copper and low conductivity material such as iron (or non-conductive material) so that there is produced a change in reluctance corresponding to eddy current loss. In such a case, the surface of the sensor rod 23 made of iron or the like may be plated with copper or the like, to form a conductive pattern. The conductive pattern may be of any shapes as long as it can efficiently produce a change of magnetic resistance.
Any suitable construction may be employed for obtaining phase shift amount φ between the output signal Y and reference signal sin ωt or cos ωt. FIG. 5 illustrates an example of the phase difference detecting circuitry 30 which is capable of obtaining such phase difference amount φ in digital amount.
In FIG. 5, the phase difference detecting circuitry 30 generally comprises a reference signal generating section for generating reference AC signals sin ωt or cos ωt, and a phase difference detecting section for detecting a phase difference (phase shift amount) Dθ between the mutual induction voltages of the secondary coils 2A-2D and the reference signal sin ωt. The reference signal generating section includes a clock oscillator 31, synchronous counter 32, ROMs 33, 33b, D/A converters 34, 34b and amplifiers 35, 35b. The phase difference detecting section includes an amplifier 36, zero crossover detecting and latch circuit 38.
In the reference signal generating section, the clock oscillator 31 produces rapid and accurate clock signals, in accordance with the other elements are caused to operate. The synchronous counter 32 counts the clock signals produced from the clock oscillator 31 and provides the counted value to the ROM 33 as an address signal as well as to the latch 38.
The ROMs 33, 33b store amplitude data corresponding to the reference ac signals; that is, the ROM 33 stores amplitude data of sin ωt, and the ROM 33b stores amplitude data of cos ωt. Each of the ROMs 33, 33b is responsive to the address signal (counted value) from the counter 32 for producing an amplitude data of the corresponding reference AC signal. More specifically, the ROMs 33, 33b receive the same address signal from the counter 32, in response to which they output two kinds of reference AC signals sin ωt and cos ωt. Alternatively, the two kinds of reference AC signals sin ωt and cos ωt may be produced by reading out the same ROM with address signals of different phases.
The D/A converters 34 and 34b convert the digital amplitude data from the corresponding ROMs 33 and 33b into analogue signals and provide these analogue signals to the amplifiers 35 and 35b. The amplifiers 35 and 35b in turn amplify the analogue signals and provide, as the reference ac signals sin ωt and cos ωt, the amplified analogue signals to the primary coils 1A-1D. If the frequency division number is M, then the counted value of M corresponds to the maximum phase angle 2π radian (360° ) of the reference AC signal; that is, one count of the counter 32 indicates a phase angle of 2π/M.
In the phase difference detecting section, the amplifier 36 amplifies the sum of secondary voltages induced in the secondary coils 2A-2D and outputs the amplified sum to the zero crossover detecting circuit 37. Based on the mutual voltages (secondary voltages) induced in the secondary coils 2A-2D, the zero crossover circuit 37 detects a zero crossover point where negative voltage changes to positive voltage and outputs a zero crossover detection signal to the latch circuit 38. Thus, upon receipt of the zero crossover detection signal (namely, upon detection of a zero crossover point), the latch circuit 38 latches the count of the counter 32 which has initiated counting in response to a clock signal defining the rise of the reference AC signals. Accordingly, the value latched in the latch circuit 38 accurately indicates the phase difference (phase shift amount) Dθ between the reference ac signals and the mutual induction voltage (composite secondary output). A current position in the entire stroke of the piston 2a can be detected on the basis of this phase difference Dθ.
FIG. 6 illustrates the construction of the brake 24 which is in the form of a pneumatic brake mechanism. The cylindrical casing 61 is provided around the brake rod 22. The bearings 24L, 24R are provided at opposite ends of the casing 61 in such a manner that they are slidable on and along the brake rod 22 in the axial direction of the rod 22. The bearings 24L, 24R contain packing members 62a, 62b and 63a, 63b respectively for maintaining airtightness within the casing 61.
Within the casing 61, several pipes are provided for supplying pressurized air from the air pressure source 66 via the electromagnetic valve 65 to the air chambers 67L, 67R and 68. The brake pistons 69L, 69R are in contact with the casing 61 via the packing members 70a, 71a and also in contact with the brake rod 22 via the packing members 70b, 71b in such a manner that they are slidable on and along the brake rod 22 in the axial direction of the rod 22. Further, the brake pistons 69L, 69R cooperate with the casing 1 for forming the air chambers 67L, 67R and 68. In the air chamber 68 formed between the brake pistons 69L, 69R, plurality of coil springs 72 are provided around the brake rod 22. The coil springs 72 extend between the brake pistons 69L, 69R and act to resiliently push the pistons 69L, 69R outwardly, i.e., apart from each other.
Each of the brake bushes 74L, 74R is a C-shaped bush provided around the brake rod 22 and is freely movable along the rod 22 in the normal state in which no external force is applied.
Coned dish springs 73L, 73R are provided around the respective brake bushes 74L, 74R. The inner circumferential edges of the springs 73L, 73R are in contact with the outer surface of the respective bushes 74L, 74R, while the outer circumferential edges of the springs 73L, 73R are in contact with the inner surface of the respective brake pistons 69L, 69R. With such arrangements, as the distances between the brake bushes 74L, 74R and the brake pistons 69L, 69R become smaller, the coned dish springs 73L, 73R are progressively widened at their outer circumferential edge portions to apply radially inward forces to the brake bushes 74L, 74R. Thus, the brake bushes 74L, 74R are radially inwardly compressed to firmly engage the brake rod 22, in order to effect braking. After that, as the distances between the brake bushes 74L, 74R and the brake pistons 69L, 69R become greater, the coned dish springs 73L, 73R are progressively restored to its original or normal state to eliminate the compressional forces from the bushes 74L, 74R. Thus, the brake bushes 74L, 74R disengage the brake rod 22 to stop braking.
When the air pressure source 66 is in the off-state, namely, not being activated, the brake pistons 69L, 69R are resiliently pushed apart from each other by the coil spring 72, and the coned dish springs 73L, 73R are pressed against the inner surface of the casing 61 via the brake pistons 69L, 69R. The inner diameters of the coned dish springs 73L, 73R thus pressed cause the brake bushes 74L, 74R to be pressed against the brake rod 22. Thus, the brake 24 is maintained in the braking state by the frictional force between the brake bushes 74L, 74R and the brake rod 22. Therefore, even when the air pressure source 66 is in the off-state, the brake 24 can be maintained in self-locking state (braking state).
When the air pressure source 66 is in the on-state, namely, is being activated, braking function by the brake 24 is controlled by on/off of the electromagnetic valve 65. When the electromagnetic valve 65 is in the off-state as shown in FIG. 6, pressurized air is introduced from the source 66 into the air chamber 68, and the air chambers 67L, 67R are exposed to the external atmosphere. Thus, the brake pistons 69L, 69R which are, as previously noted, normally pushed by the resilient force of the coil springs 72 are even more strongly pushed outwardly away from each other by additional high pressure of the introduced pressurized air. Accordingly, the coned dish springs 73L, 73R are pressed against the inner surface of the casing 61 with much greater force than when the air pressure source 66 is in the off-state, and hence the brake 24 is able to provide a greater braking force.
On the other hand, when the electromagnetic valve 65 is in the on-state, pressurized air is introduced from the source 66 into the air chambers 67L, 67R, and the air chamber 68 is exposed to the external atmosphere. Thus, high pressure of the introduced pressurized air acts to reduce the resilient force of the coil springs 72, so that the brake pistons 69L, 69R are moved inwardly toward each other against the bias of the coil springs 72. This eliminates the pressing force applied to the coned dish springs 73L, 73R, so that the brake bushes 74L, 74R disengage the brake rod 22. In this way, the braking force by the brake 24 is eliminated, and the brake bushes 74L, 74R are free to move along the brake rod 22.
In the preferred embodiment so far described, one brake 24 and one sensor 25 are provided on their respective rods. However, one brake 24 may be provided on each of the two rods, with the sensor 25 being provided on either of the rods. Alternatively, the brake 24 and sensor 25 may be provided on the same rod. Further, a rod may be provided within the cylinder tube to support thereon the piston and piston yoke in such a manner that the piston and piston yoke can move in the axial direction of the rod. The brake and sensor may be provided in the piston yoke.
Moreover, it is a matter of course that the brake may be of a mechanical type or any other types than the pneumatic type as described above.
Although the rodless cylinder 1 has been described as being secured at opposite ends to the securing plates 21L, 21R, the rodless cylinder 1 need not be secured directly to the securing plates 21L, 21R, as long as the brake rod 22 and sensor rod 23 form beams between the plates 21L, 21R and the rodless cylinder 1 is mounted in such a manner that the table can move along the rods. Namely, the rodless cylinder 1 may be fixedly connected with each rod 22, 23 in relative manner via securing plate etc.
Further, the rodless cylinder apparatus of the present invention may of course be realized by using a rodless cylinder other than that illustrated in FIGS. 7 to 9. Although the brake rod and sensor rod have been described as being exposed to the external environment, the entire rodless cylinder apparatus may be accommodated in a casing to be protected from dust in the external environment. In addition, a plurality of the rodless cylinder apparatuses of the invention may be employed to provide a robot which can freely move in two or three-dimentional coordinate space in controlled manner. In this case, it suffices only to interconnect the tables of the respective cylinder apparatuses forming the X-axis and Y-axis.
With the arrangements so far described, the rodless cylinder of the invention can have a greatly increased rigidity against external load, and also is capable of easily positioning the piston to stop accurately at a desired position in its stroke. | The rodless cylinder includes at least a cylinder tube and a piston, but it has no piston rod that is indispensable in the conventional cylinders. The article carrier is connected via the piston yoke to the piston and movable with parts and jigs placed thereon as the piston moves along the cylinder. At least one rod is fixed relative to the cylinder tube to extend in parallel with the direction in which the piston and hence the carrier moves. The sensor is provided to be movable along the rod as the piston moves. The sensor has a moving member movable along the rod as the piston moves within the cylinder tube, for detecting a current position of the piston in accordance with relative positional relation between the moving member and the rod. With such arrangements, the rodless cylinder as a whole has a higher rigidity against heavy load, and also the piston can be accurately positioned to stop at a desired position in its stroke. | 5 |
TECHNICAL FIELD
[0001] The present invention relates to downhole screens, and more particularly relates, in one non-limiting embodiment, to downhole screens that can be expanded or deployed in response to locally applied heat.
TECHNICAL BACKGROUND
[0002] In the past, sand control methods have been dominated by gravel packing outside of downhole screens. The idea was to fill the annular space outside the screen with sized gravel to prevent the production of undesirable solids (sand) from the formation. More recently, with the advent of tubular expansion technology, it was thought that the need for gravel packing could be eliminated if a screen or screens could be expanded in place to eliminate the surrounding annular space that had heretofore been packed with gravel. Problems arose with the screen expansion technique as a replacement for gravel packing because of wellbore shape irregularities. A fixed swage would expand a screen only a fixed amount. Problems still included that a washout in the wellbore would still leave a large annular space outside the screen. Conversely, a tight spot in the wellbore could create the risk of sticking the fixed swage.
[0003] One improvement of the fixed swage technique was to use various forms of flexible swages. In theory, these flexible swages were compliant so that in a tight spot they would flex inwardly and reduce the chance of sticking the swage. On the other hand, if there was a void area, the same problem persisted in that the flexible swage had a finite outer dimension to which it would expand the screen. Therefore, the use of flexible swages still left the potential problem of annular gaps outside the screen with a resulting undesired production of solids when the well was put on production from that zone.
[0004] Prior designs of screens have used a pre-compressed mat held by a metal sheath that is then subjected to a chemical attack when placed in the desired location downhole. The mat is then allowed to expand from its pre-compressed state. The screen per se is not expanded. This design is described in U.S. Pat. Nos. 2,981,332 and 2,981,333. U.S. Pat. No. 5,667,011 shows a fixed swage expanding a slotted liner downhole. U.S. Pat. Nos. 5,901,789 and 6,012,522 show well screens being expanded. U.S. Pat. No. 6,253,850 shows a technique of inserting one solid liner in another already expanded slotted liner to blank it off and the use of rubber or epoxies to seal between the liners. U.S. Pat. No. 6,263,966 shows a screen with longitudinal pleats being expanded downhole. U.S. Pat. No. 5,833,001 shows rubber cured in place to make a patch after being expanded with an inflatable. Finally, U.S. Pat. No. 4,262,744 is of general interest as a technique for making screens using molds.
[0005] U.S. Pat. No. 7,318,481 describes a screen assembly that includes a material that conforms to the borehole shape after insertion. The assembly comprises a compliant layer that takes the borehole shape on expansion. The outer layer is formed having holes to permit production flow. The material that is selected preferably swells with heat and in one non-limiting embodiment preferably comprises a shape memory foam that is thermoset. The base pipe may have a screen over it to act as an underlayment for support of the conforming layer or alternatively for screening. The conforming layer can expand by itself or expansion may also occur from within the base pipe. This design could be improved if the expansion of the compliant layer were activated by heat locally at its downhole location to a temperature greater than that experienced by the screen assembly on its trip into the hole. If the compliant layer experiences too much heating in advance of placement, it will deploy prematurely, and in most cases be difficult or impossible to dislodge.
[0006] A difficulty with supplying heat downhole by injecting a heated medium is that the heat will be dissipated during transmission and insufficient heat will be delivered to the desired site. Methods are known for providing heat only locally downhole, but they each have difficulties. Downhole heaters, such as electrically-powered heaters, such as a wireline deployed electric heater, or a battery fed heater, may generally lack sufficient power (amperage) to provide the necessary heat for deployment. Downhole combustion processes are also known to generate heat. However, most exothermic oxidation/combustion reactions require temperatures that would compromise mud stability, if not tubular integrity, and would tend to be difficult to initiate and would be problematic to formulate as a liquid or mud for downhole use. Again, initiating the reaction at the surface would tend to expend and dissipate most of the heat before placement in the target or the mud for downhole use. Hydration of acidic electrolytes (such as aluminum chloride, AlCl 3 ) or acids would also generate heat, but would be expected to be corrosive and at high temperatures could compromise the integrity of the tubular goods, tools, screens and other equipment in many circumstances. For instance, hydration of aluminum chloride would produce a product environment of about pH 0.8, as contrasted with using NaOH, which would generally yield a product environment of about pH 14. There are also heat generating reactions that can be timed through control of the reaction rate through manipulation of pH and other methods such as processes like N-SITU developed by Shell Oil Co. This technology is found in U.S. Pat. Nos. 4,178,993; 4,219,083; 4,289,633; and 4,330,037. This method is a surface-mixed reaction that must be carefully timed with pump rate and the like in order for the heat liberation to occur in a specific zone of interest. While this operation can be accomplished by those skilled in the art, unforeseen circumstances can cause last minute disruptions to this scheduled treatment, and the heat can be liberated in an undesired location in the wellbore.
[0007] It would thus be very desirable and important to discover a method and apparatus for deploying a compliant layer only at a particular temperature or temperature range at a particular location downhole.
SUMMARY
[0008] There is provided, in one form, a well completion method that involves covering at least one base pipe at least partially with a porous conforming material. The base pipe is run in to a desired location in a wellbore with the conforming material. The conforming material is heated to deploy it to bridge an annular gap to a wellbore wall. This may be done without base pipe expansion. The heat is provided locally downhole by a catalytic reaction that produces steam. Finally, fluids are produced through or filtered through the conforming material to the base pipe. In one non-limiting, alternative embodiment the conforming material is not radially constricted.
[0009] In another embodiment, there is provided a deployable screen assembly that includes a base pipe covered at least partially with a porous conforming material. The porous conforming material deploys in the presence of heat. A catalyst is provided on the assembly in proximity to the porous conforming material, where the catalyst is capable of generating heat upon contact with a fuel together with an oxidant.
BRIEF DESCRIPTION OF THE DRAWINGS
[0010] FIG. 1 is a cutaway view of the screen shown in elevation;
[0011] FIG. 2 is a section view of an assembly of screens, one of which is shown in FIG. 1 , in the expanded position downhole;
[0012] FIG. 3 is a section, cutaway view of an alternative construction of the screen described herein; and
[0013] FIG. 4 is a section view of the end of washpipe string containing catalyst.
DETAILED DESCRIPTION
[0014] It has been discovered that a novel chemical catalyst system may deploy a shape memory foam screen to accomplish the purpose of expanding the screen to bridge an annular gap to a wellbore wall at a relatively precise downhole location. The simplicity and heat generated locally make it a much more attractive alternative than conventional downhole heating devices that lack sufficient amperage to produce the required heat for deployment, or where the heat dissipates from the surface to the deployment site.
[0015] The apparatus and method herein addresses the task of providing a sand control screen downhole by providing a screen assembly with an outer layer that can conform to the borehole shape upon expansion. In one non-limiting embodiment, a material is selected that will swell, expand, enlarge or otherwise deploy to further promote filling the void areas in the borehole after expansion. In an alternative design, screen expansion is not required and the outermost layer swells to conform to the borehole shape upon heating. The screen section may be fabricated in a manner that reduces or eliminates welds. Welds are placed under severe loading in an expansion process, so minimizing or eliminating welds provides for more reliable screen operation after expansion.
[0016] One of the problems with using shape memory foams as a porous conforming material on the screen assemblies is that it wants to redeploy to its original, larger diameter when it experiences its glass transition temperature (Tg) or higher. It may be difficult to formulate the conforming material to its Tg because the material is too soft at Tg, which collapses the pores and stops flow and filtration through the material with relatively very small pressure differentials. This would defeat the purpose of using it as a screen. Also, since many applications for the screens herein are in horizontal wells, the Tg could be inadvertently and undesirably reached in the vertical section, but the screen may have to travel another 10,000 feet or more, requiring hours of run in. The shape memory foams, which are particularly suitable during and after placement, deploy in minutes at their Tg. Having a conforming material with a higher Tg than the bottom hole temperature where the screen is to be deployed would permit the screen to be located, contacted by heat from a local heat source to deploy the conforming material, to give a rigid, filtration foam when the material is cooled well below its Tg.
[0017] These and other advantages of the present method and apparatus will become more apparent to one skilled in the art from a review of the description of them and the claims that appear below.
[0018] FIG. 1 illustrates a portion of a section of a deployable screen assembly 10 . It has a base pipe 12 over which is the screen 14 and over which is outer conforming layer 16 . Layer 16 has a plurality of holes 18 . The base pipe 12 also has holes 20 . The actual filter material or screen 14 may be a mesh or a weave or one or more of other known filtration products. One non-limiting type of suitable conforming layer 16 is one that is soft so that it will flow upon optional expansion of the screen 10 . In another non-restrictive embodiment, material for the conforming layer 16 is one that will swell when heated. Suitable examples include, but are not necessarily limited to, porous polynitrile, HNBR, VITON, TEFLON, epoxy or polyurethane. In an alternative, particularly suitable embodiment, the conforming layer 16 swells sufficiently after being run into the wellbore, to contact the wellbore, without expansion of the screen 10 . Shown schematically at the ends 22 and 24 of screen 10 are stop rings 26 and 28 . These stop rings will contain the conforming layer 16 upon optional expansion of screen 10 against running longitudinally in an annular space outside screen 10 after it is expanded. Their use is optional. In one non-limiting, alternative embodiment the conforming material is not radially constricted.
[0019] In a particular aspect of the invention, the deployable screen assembly 10 contains a catalyst that when contacted with fuel will evolve sufficiently high temperature steam to raise the outer conforming layer 16 to its Tg to deploy it in a matter of minutes to bridge the annual gap between the assembly 10 and the borehole 30 wall; please see FIG. 2 for an embodiment where the conforming layer 16 is deployed. This steam evolution may be instantaneous or essentially instantaneous. The catalyst 39 may be placed in a concentric washpipe string 38 which is traditionally run in such applications or can be accommodated in engineered couplings on each joint, as schematically illustrated in FIG. 4 . Concentric washpipe string 38 has a bull plug 40 on its closed end, and a plurality of orifices 42 to permit the steam generated by the catalyst 39 to escape string 38 and contact the conforming layer 16 . Alternatively, the catalyst may be placed on another structure in relatively close proximity to the screen assembly 10 , by which is meant sufficiently close for the evolved steam to effectively contact and deploy the conforming layer 16 . In one non-limiting embodiment, the steam evolved should be in the range of from about 110 to about 500° C.; alternatively from a lower threshold of about 150° C. independently to an upper threshold of about 350° C. The overall temperature increase is dependent on the amount of fuel and the length of wellbore interval to be treated.
[0020] A number of possible catalysts may be used to evolve high temperature steam sufficiently quickly when contacted with the appropriate fuel. Oxford Catalysts, a UK company spun out of Oxford University, has developed a catalyst, described in WO2005/075342 A1 (EP 1711431), incorporated herein in its entirety by reference, that causes methanol (CH 3 OH) and hydrogen peroxide (H 2 O 2 ) to react exothermically to instantly form steam and carbon dioxide (CO 2 ). The catalyst decomposes the peroxide into water and oxygen, evolving much heat. The oxygen and methanol then react to liberate more heat, water and CO 2 . Unusually, the steam temperature is independent of the pressure, although it will be appreciated that the relatively instantaneous evolution of steam in a confined space such as the production zone of a wellbore will create pressure. Steam temperatures of about 500-800° C. may be evolved simply by pumping the fuel (methanol and hydrogen peroxide) to contact the catalyst. Steam generation using this catalyst may occur in a volume 25 times smaller than a conventional boiler to generate the same amount of steam. Simplified thermodynamic calculations indicate that as little as 150 gallons (568 liters) of this fuel could raise the temperature of 1,000 feet (305 m) of 6.625 inch (16.8 cm) casing from 150° F. to about 335° F. (65.6-168.8° C.). Since this liberation of heat does not occur until there is contact with a catalyst, the placement of this liberated energy becomes considerably more accurate. WO 2005/075342 also teaches that other substances can be used as fuels for this steam generation, e.g., C 1 to C 5 alcohols and combustible hydrocarbons. This document discloses that catalysts of metals of Groups 7, 8, 9, 10, and 11 of the Periodic Table are suitable, for instance a platinum catalyst is expected to be particularly suitable.
[0021] U.S. Pat. No. 4,456,069, incorporated by reference herein, teaches the generation of a gas where a reactant, such as hydrogen peroxide, is decomposed by a catalyst to form high temperature decomposition gases, such as steam and oxygen. A silver catalyst is mentioned. In this process, the gas is generated on the surface at relatively high velocity and very high temperature before being injected into a well to elevate the pressure and temperature within the well formation to stimulate the formation through the effects of thermal stress and high pressure gas flow.
[0022] Similarly, U.S. Statutory Invention Registration H1948, also incorporated by reference herein, discloses a high-activity hydrogen peroxide decomposition catalyst that includes an impregnated and calcined substrate with catalyst mixture to produce steam and oxygen. The catalyst mixture includes a H 2 O 2 catalytically active compound containing a transition metal cation mixed with an alkaline promoter. The transition metal may be any of the elements from Groups VB, VIB, VIIB, VII and IB of the Periodic Table of Elements. The alkaline promoter may be any compound which provides a basic solution containing elements from Groups IA and IIA of the Periodic Table of Elements. Preferably, the promoter and transition metal are mixed at a molar ratio of from about 0.5 to about 4.0.
[0023] Further, U.S. Pat. No. 6,837,759, additionally incorporated by reference herein, relates to a self-contained propulsion apparatus, such as would be suitable for a sub-sea remotely operated vehicle. The propulsion apparatus contains a fuel and an oxidant that react catalytically to form steam. Various catalysts suitable for use in combustion or oxidation reactions and/or for hydrogen peroxide decomposition are well known in the art. Suitable catalysts disclosed include metals such as platinum, ruthenium and copper, and metal oxides such as cupric oxide (CuO), copper manganese oxide (CuMn 2 O 4 ), or manganese oxide (MnO). The catalyst is taught as conveniently supported on alumina (Al 2 O 3 ) or carbon. Other suitable supports for the catalyst include silica (SiO 2 ) and titania (TiO 2 ).
[0024] The manner of assembly of the screen assembly 10 is another aspect of the invention. The conforming layer 16 may have an internal diameter that allows it to be slipped over the screen material 14 . The assembly of the screen material 14 and the conforming layer 16 are slipped over the base pipe 12 . Thereafter, a known expansion tool may be applied internally to base pipe 12 to slightly expand it. As a result, the screen material 14 and the conforming layer 16 are both secured to the base pipe 12 without need for welding. This is advantageous because when the screen 10 is run in the wellbore and expanded, the expansion process can put large stresses on welds that may cause screen failure. A non-limiting alternative way to assemble screen 10 is to attach the screen material 14 to the base pipe 12 in the manner just described and then to cure the conforming layer 16 right onto the screen material 14 . As another option a protective outer jacket 32 , shown in FIG. 3 , can be applied over screen material 14 and the conforming layer 36 mounted above. The joining process even with the optional perforated protective jacket 32 is the outward expansion from within the base pipe 12 , as previously described.
[0025] The holes 18 may have a variety of shapes. Their function is to allow formation fluids to pass after expansion. They can be a foam matrix, round holes or slots or other shapes or combinations of shapes. The conforming layer 16 may be made of a polymeric material and is preferably one that swells on exposure to sufficiently high temperature for effective but relatively short time periods to better conform to irregular shapes in the borehole 30 , as shown in FIG. 2 . Jacket 32 is a known product that has punched openings 33 and may optionally be used if the conforming layer 16 is used. The reason it is optional is that the conforming layer 16 to some degree provides the desired protection during run in. Additionally, without jacket 32 , the conforming layer 16 may be made thicker to better fill in void volume 34 in the annular space around a screen 10 after expansion. The thickness of the conforming layer 16 is limited by the borehole and the outer diameter of the components mounted inside of it. It is acceptable in one embodiment that the conforming layer 16 be squeezed firmly as that promotes its movement to fill voids in the surrounding annular space.
[0026] Those skilled in the art will appreciate that the apparatus and method herein allows for fabrication of an expandable screen with welds between layers eliminated. The use of the conforming material 16 allows a variety of expansion techniques to be used and an improvement of the ability to eliminate void spaces outside the expanded screen caused by borehole irregularities. Alternatively, the conforming material 16 may swell sufficiently without downhole expansion of the screen 10 to allow for the elimination of the need to gravel pack. If the material swells due to exposure to fluids downhole, its use as the conforming layer 16 is desired. A protective jacket 32 under the conforming layer 16 may be used as mechanical support for conforming layer 16 .
[0027] The conforming layer 16 may be a foam that is preferably thermosetting but can also be a thermoplastic if they are porous or may be produced in that condition. The conforming layer 16 is shown with a cylindrical shape, but this may be varied, such as by means of concave ends or striated areas (not shown), to facilitate deployment, or to enhance the filtration characteristics of the layer. In one non-limiting embodiment, the conforming layer 16 may be composed of an elastic memory foam such as an open cell syntactic foam and/or viscoelastic foam. This type of foam has the property of being convertible from one size and shape to another size and/or shape, by changing the temperature of the foam. Other foams expected to be useful in the methods and structures herein include polyurethane foams, epoxy foams, polyethers, polyesters, reticulated polyesters, ester-like-ether polymers, and polyethylene, and combinations thereof. This type of foam may be formed into an article with an original size and shape as desired, such as a cylinder with a desired outer diameter. The foam article thusly formed is then heated to raise its temperature to its transition temperature (Tg). As it achieves the transition temperature, the foam softens, allowing the foam article to be reshaped to a desired interim size and shape, such as by being compressed to form a smaller diameter cylinder. The temperature of the foam article is then lowered below the transition temperature, to cause the foam article to retain its interim size and shape. When subsequently raised again to its transition temperature Tg in position downhole, the foam article will return to its original size and shape.
[0028] The cylindrical foam conforming layer 16 may be originally formed onto the screen 10 or the base pipe 12 by wrapping a foam blanket with the desired original outer diameter OD 1 . Alternatively, the process for forming the conforming layer 16 on the base pipe 12 or screen 10 may be any other process which results in the conforming layer 16 having the desired original diameter, such as by molding the foam directly. The desired original outer diameter OD 1 is larger than the bore hole diameter (BHD) in which the assembly will be deployed. For instance, a conforming layer 16 having an original outer diameter OD 1 of 10 inches (25.4 cm) might be formed for use in an 8.5 inch (21.6 cm) diameter borehole.
[0029] The foam material composition may be formulated to achieve the desired transition temperature (Tg). This quality allows the foam to be formulated in anticipation of the desired transition temperature to be used for a given application. For instance, in use with the present methods and apparatus, the foam material composition may be formulated to have a transition temperature up to just slightly below the anticipated steam temperature to be evolved at the depth at which the assembly will be used. This causes the conforming layer 16 to expand at the steam temperature created locally at the desired depth, and to remain expanded against the bore hole wall once it is cooled. Downhole temperature in conjunction with the steam temperature may be used to expand the conforming layer 16 . That is, the conforming material may be formulated to give a material with a particular Tg that takes into account the addition of the downhole temperature to the evolved steam temperature.
[0030] The conforming layer 16 may be made to act as the sole filtration agent without the use of any screen material such as 14 or 32 . This is because the nature of the conforming material is to be porous, e.g. an open-cell foam. However, a normal technique for its production may be a mold that leaves an impervious coating or layer on the entire outer periphery thereof. This quality allows the material to be used as a packer material essentially in the condition in which it is removed from the mold. However, if the exterior surface that ultimately has contact with the borehole wall has the impervious layer stripped off or otherwise removed, the conforming layer 16 may be mounted to a base pipe 12 or a screen 14 or 32 and it may act solely as the only filtration material or in conjunction with the screen 14 . The screen 14 or 32 may be configured exclusively for structural support of the conforming material 16 to keep it from going through the base pipe 12 when well fluids are filtered through it or omitted altogether. The uphole and downhole ends of the conforming material 16 may have the impervious layer from the molding process of manufacturing left on to better direct flow to the openings in the base pipe 12 . Alternatively, the impervious layer may be removed to expose pores therethrough.
[0031] In the foregoing specification, the invention has been described with reference to specific embodiments thereof, and has been demonstrated as effective in providing methods and apparatus for completing wells by setting screens. However, it will be evident that various modifications and changes can be made thereto without departing from the broader spirit or scope of the invention as set forth in the appended claims. Accordingly, the specification is to be regarded in an illustrative rather than a restrictive sense. For example, specific combinations of conforming materials, catalysts, fuels, and other components falling within the claimed parameters, but not specifically identified or tried in a particular composition or apparatus, are anticipated to be within the scope of this invention.
[0032] The terms “comprises” and “comprising” in the claims should be interpreted to mean including, but not limited to, the recited elements. | A screen assembly has a material that conforms to the borehole shape after insertion. The assembly comprises a compliant layer that takes the borehole shape on expansion. The outer layer is formed having holes to permit production flow. The selected conforming material swells with heat, and in one non-limiting embodiment comprises a shape memory foam that is thermoset or thermoplastic. Heat is provided by supplying a fuel (including an oxidant) to a catalyst in close proximity to the compliant layer so that the product from the catalytic reaction is heated steam which contacts and deploys the conforming material. The base pipe can have a screen over it to act as an underlayment for support of the conforming layer or alternatively for screening. | 4 |
CROSS-REFERENCES TO RELATED APPLICATIONS
This application is a U.S. National Phase of PCT/US07/066764, filed on Apr. 17, 2007, which claims the benefit of U.S. provisional patent application Ser. No. 60/792,806, filed Apr. 17, 2006, the disclosures of which are incorporated herein in their entirety by reference for all purposes.
STATEMENT AS TO RIGHTS TO INVENTIONS MADE UNDER FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
This invention was made with Government support of Grant No. A1058708, awarded by the National Institutes of Health. The Government has certain rights in this invention.
FIELD OF THE INVENTION
The present invention generally relates to methods and compositions useful for the elimination of latent HIV reservoirs that persist despite highly active antiretroviral therapy (HAART).
BACKGROUND OF THE INVENTION
Human Immunodeficiency Virus (HIV) is the etiologic agent that is responsible for AIDS, a syndrome characterized by depletion of CD4 + T-lymphocytes and collapse of the immune system. HIV infection is pandemic and HIV-associated diseases have become a world-wide health problem. Upon infection, HIV integrates into the cellular genome of an infected cell. HIV infection then leads to two different scenarios: productive infection and latent infection. Productive infection occurs most frequently and leads to death of the infected cell after release of progeny virus. During latent infection, which is rare, HIV genes are not expressed after proviral integration, resulting in an infected cell that is characterized by transcriptionally silent HIV genes. These fully replication-competent HIV can persist dormant in cells for several years and then become reactivated (Chun et al., 1995, Nature Med 1(12):1284-1290; Chun et al., 1997, Proc Natl Acad Sci USA 94(24):13193-13197; for review, see Bisgrove, 2005, Expert Rev Anti Infect Ther 3(5):805-814).
Current treatments of AIDS typically seek to block one or more steps involved in the production of viral particles. Treatment options involve administration of reverse transcriptase inhibitors, inhibitors of viral protease, fusion, entry, or integration inhibitors in different combinations to block multiple steps in the viral life cycle. This approach, termed highly active antiviral therapy (HAART) has greatly decreased morbidity and mortality in people infected with HIV (Palella et al., 1998, N Engl J Med 338(13):855-860).
However, long-term follow-up studies have shown that HAART alone is not effective in completely eliminating HIV in infected patients. In most cases, upon ceasing HAART a rapid rebound in viremia occurs even after years of successful treatment with undetectable viral loads (Davey et al., 1999, Proc Natl Acad Scxi USA 96(26):15109-15114; Cohen and Fauci, 2001, Adv Intern Med 46:207-246). The rebound in viremia is believed to be due at least in part to the reactivation of latent HIV. Latent forms of HIV are not sensitive to HAART because these drugs (e.g., reverse transcriptase inhibitors, viral protease inhibitors) are only active against actively replicating forms of HIV. Although the frequency of latently-infected cells is only about 0.03-3 infectious units per million resting CD4 + T-cells (Siliciano et al., 2003, Nature Med 9(6):727-728), this latent population of HIV serves as a source of virus for reseeding the infection after discontinuation of HAART. Due to the longevity of this latent HIV reservoir, it is unlikely that HAART alone can ever clear it completely (Siliciano et al., 2003, Nature Med 9(6):727-728).
HIV latency is closely tied to expression of HIV genes, i.e., to HIV transcription, which initiates at a promoter located in the 5′ LTR driving transcription of the viral genome. The LTR comprises essentially 4 regions: a negative regulatory element (NRE), an enhancer region, a core promoter and a 5′ untranslated region (UTR) (for review, see Bisgrove, 2005, Expert Rev Anti Infect Ther 3(5):805-814). Of particular interest for activation of HIV expression is the enhancer region, which can be subdivided into a distal and proximal region. Several transcription factors bind to these regions. For example, Ets-1 and LEF-1 bind to the distal enhancer region, while the inducible transcription factors nuclear factor-kappa B (NF-κB) and NF-AT bind to and activate HIV transcription from the proximal enhancer.
Select viral proteins are also involved in activation of HIV gene transcription. For example, one of the early proteins expressed from the HIV genome is Tat, a viral transactivator that binds to an RNA recognition element (TAR) present in all viral transcripts and primarily drives high level of HIV expression by enhancing transcriptional elongation in of RNA polymerase II after binding to the HIV LTR.
Recently, several lines of evidence pointed to an inhibitory effect of chromatin on HIV gene expression initiated on the integrated HIV genome. With respect to histone H3, a protein component of a nucleosome (the base unit of chromatin), acetylation or methylation of amino acid residue lysine 9 has been implicated in transcriptionally active or inactive chromatin, respectively. It has been recognized that nucleosomes can negatively regulate gene expression by, e.g., preventing access to the DNA binding sites of transcription factors, thereby reducing or silencing expression of nearby genes (Owen-Hughes and Workman, 1994, Crit Rev Eukaryot Gene Expr 4(4):403-441; Knezeetic and Luse, 1986, Cell 45(1):95-104).
Prior to transcriptional activation, 5 nucleosomes are precisely positioned in the 5′ LTR of HIV. Nucleosome nuc-0, encompassing part of the NRE region is separated from nucleosome nuc-1 by a 265 bp nucleosome-free region, containing binding sites for transcription factors C/EBP, LEF-1, NF-κB, NF-AT, Sp1 and the TATA box (Verdin et al., 1993, EMBO J 12(12):4900; Jones and Peterlin, 1994, Annu Rev Biochem 63:717-743). Upon activation, nuc-1 is rapidly remodeled which may relieve a block to HIV gene transcription. Reactivation of HIV latency seems also to involve recruitment of acetyltransferase to the HIV-LTR, followed by acetylation of histones H3 and H4 (Lusic et al., 2003, EMBO J 22(24):6550-6561; Bisgrove, 2005, Expert Rev Anti Infect Ther 3(5):805-814). Thus, chromatin is an integral component of the HIV transcriptional regulatory machinery and modulation thereof are expected to have a direct impact on the expression of HIV genes.
Further, HIV latency may also be explained by integration of the HIV genome into heterochromatin, a transcriptionally repressive form of chromatin, that eventually may become reorganized leading to the activation of latent HGIV-1 expression (Jordan et al., 2003, EMBO J 22(8):1868-1877). Another mechanism underlying HIV latency may be transcriptional interference with a near-by gene (Han et al., 2004, J Virol 78(12):6122-6133).
Two strategies have been proposed to overcome the problem that current HAART is unable to completely clear the latent HIV reservoir. The first one can be described as an intensified HAART aiming to prevent even a very low level viral replication (Ramratnam et al., 2004, J Acquir Immune Defic Syndr 35(1):33-37). A second approach aims at eliminating the pool of latently infected cells by inducing HIV replication in these cells, while maintaining the patient on HAART to prevent a spreading infection. The latently-infected cells would then be eliminated by the immune system or virus-mediated cell lysis.
In pursuing the second approach, purging the latent HIV pool by activation of viral transcription, several clinical trials have been performed, however, with limited success so far. For example, studies using IL-2 or IL-2 and OKT3 have not shown significant reduction in the latent reservoir and viral rebound continues after cessation of HAART (Chun et al., 1999, Nat Med 5:651-655; van Praag et al., 2001, J Clin Immunol 21:218-226; Blankson et al., 2002, Ann Rev Med 53:557-593). Another potential drug useful for viral purging is IL-7 (Smithgall et al., 1996, J Immunol 156(6):2324-2330; Scripture-Adams et al., 2002, J Virol 76(24):13077-13082).
Recently, prostratin and the related 12-deoxyphorbol 13-phenylacetate (DPP) were described as promising inducers of latent HIV. Prostratin is a nontumor-promoting phorbol ester initially isolated in screens for inhibitors of HIV replication (Gustafson et al., 1992, J Med Chem 35(11):1978-1986). However, further studies indicated that in addition to blocking HIV infection, prostratin treatment, also upregulated HIV transcription from latent proviruses (Kulkosky et al., 2001, Blood 98(10:3006-15; Korin et al., 2002, J Virol 76(16):8118-8123; Biancotto et al., 2004, J Virol 78(19):10507-10515).
Prostratin has been reported to antagonize HIV latency by stimulating IKK-dependent phosphorylation and degradation of I κ Bα, leading to the rapid nuclear translocation of NF-κB binding of this factor to the HIV-LTR enhancer and activation of HIV expression (Williams et al., 2004, J Biol Chem 279(40):42008-42017).
To be clinically useful, activators of latent HIV expression must exhibit relatively low toxicity, permitting patients to withstand treatment with these agents (Perelson et al., 1997, Nature 387, 188-191). Although prostratin functions as an activator of latent HIV expression and was observed to lack toxicity when applied for short time courses, in its current dosage regimen, prostratin may not be useful for long-term, multiround treatments in humans. Prostratin was reported to induce substantial growth arrest and cell death if administered in a concentration of >500 nM for more than 2 days (Williams et al., 2004, J Biol Chem 279(40):42008-42017). Thus, if prostratin is to be considered as a human therapeutic, it is unlikely that high-dose or protracted treatment will be tolerated. Consequently, either short-term and/or low-dose treatments will probably be the only alternative, since sustained administration or prostrating at high-dose will probably result in dramatically negative side effects (Williams et al., 2004, J Biol Chem 279(40):42008-42017). However, no such protocols are available yet.
Histone acetylases and deacetylases play a major role in the control of gene expression. They regulate gene expression by acetylating and deacetylating lysine residues on histones as well as various transcription factors. The balance between the activities of histone acetylases, usually called acetyl transferases (HATs), and deacetylases (HDACs) determines the level of histone acetylation. Acetylated histones are associated with a relaxed, more open form of chromatin and activation of gene transcription, whereas deacetylated chromatin is associated with a more compacted form of chromatin and diminished transcription. Eleven different HDACs have been cloned from vertebrate organisms. A Class I HDACs includes HDAC1, HDAC2, HDAC3, and HDAC8 (Van den Wyngaert et al., 2000, FEBS Lett 468:77-83). A Class II HDACs includes HDAC4, HDAC5, HDAC6, HDAC7, HDAC7, HDAC9, and HDAC10 (Kao et al., 2000, Genes Dev 14:55-60; Grozinger et al., 1999, Proc Natl Acad Sci USA, 96:4868-73; Zhou et al., 2001, Proc Natl Acad Sci USA, 98:10572-77; Tong et al., 2002, Nucleic Acids Res 30:1114-23). HDAC11 has not been classified yet (Gao et al., 2002, J Biol Chem 277:25748-55). All share homology in their catalytic regions.
HDACs have also been implicated in the inhibition of HIV gene expression and thus, may contribute to establishing or maintaining HIV latency (Ylisastigui et al., 2004, AIDS 18(8):1101-1108). Further, it has been shown that NF-κB p50-HDAC1 complexes constitutively bind the latent HIV LTR and induce histone deacetylation and repressive changes in chromatin structure of the HIV LTR, changes that impair recruitment of RNA polymerase II and transcriptional initiation (Williams et al., 2006, EMBO J 25:139-149).
Thus, histone deacetylase (HDAC) inhibitors are also being considered as an adjuvant with HAART (see, Bisgrove, 2005, Expert Rev Anti Infect Ther 3(5):805-814). HDAC inhibitors have the ability to activate a range of HIV subtypes in a variety of different cell types (Van Lint et al., 1996, EMBO J 15(5):1112-1120; Quivy et al., 2002, J Virol 76(21):11091-11103). Some HDAC inhibitors are already in clinical use. For example, valproic acid is widely used to reduce epileptic seizures, and phenylbutyrate is used to treat sickle cell anemia and various forms of thalassemia, establishing their safety profile. Recently, it was suggested that the HDAC inhibitor valproic acid may have effects on the activation of latent HIV (Ylisastigui et al., 2004, AIDS 18(8):1101-1108).
TSA has been shown to synergize with both ectopically expressed p50/p65 and tumor necrosis factor alpha (TNF-α)/SFα (TNF)-induced NF-κB to activate the HIV LTR (Quivy et al., 2002, J Virol 76(21):11091-11103).
In another study, TSA, has been shown to inhibit HDAC1, leading to the recruitment of RNA polymerase to the latent HIV LTR. This bound polymerase complex, however, remains non-processive, generating only short viral transcripts. Synthesis of full-length viral transcripts can be rescued by the expression of Tat (Williams et al., 2006, EMBO J 25:139-149).
Cells latently infected with HIV represent a currently insurmountable barrier to viral eradication in infected patients. New approaches for the elimination of the latently infected HIV cells are urgently needed (see Pomerantz, 2002, Curr Opin Invest Drugs 3:1133-1137). Applicants herewith provide compositions and methods useful for the elimination of latent HIV reservoirs that persist despite HAART. The present invention is based, in part, on the Applicants' discovery that HDAC inhibitors, such as trichostatin A and valproic acid, synergize with a small molecule activator of latent HIV expression, such as prostratin, to activate a latent HIV reservoir. This unexpected finding makes possible the use prostratin in methods for eliminating latent HIV reservoirs in a subject at much lower doses than previously possible, thereby avoiding its cytotoxic effects observed upon administering prostratin at higher doses.
BRIEF SUMMARY OF THE INVENTION
This application discloses the surprising finding that activators of latent HIV expression and inhibitors of histone deacetylase synergize to activate latent HIV expression. Thus, the present invention relates to novel compositions and kits comprising such latent HIV expression and inhibitors of histone deacetylase and the uses thereof in methods for activating latent HIV expression, methods for eliminating a latent HIV reservoir, methods for rendering latent HIV sensitive to killing by an immunotoxin, and methods for treating patients infected with latent HIV.
In a first aspect, the present invention provides a method for activating latent HIV expression in a mammalian cell having an integrated HIV genome. In a preferred embodiment of the present invention, this method comprises the steps of (a) contacting the mammalian cell with an amount of an activator of latent HIV expression effective to activate latent HIV expression to a first expression level and (b) contacting the mammalian cell with an amount of an inhibitor of histone deacetylase effective to activate latent HIV expression to a second expression level, wherein the activator of latent HIV expression and the inhibitor of histone deacetylase synergize to generate the second expression level.
Several activators of latent HIV expression can be used to practice this method. For example, an activator of latent HIV expression is selected from the group consisting of prostratin, DPP, and structural analogs thereof. A preferred activator of latent HIV expression is prostratin.
In another embodiment of the present invention, an activator of latent HIV expression is selected from the group consisting of a NF-κB inducer, Tat, NF-AT, and a NF-AT inducer.
Several inhibitors of histone deacetylase can be used to practice this method. For example, an inhibitor of histone deacetylase is selected from the group consisting of trichostatin A, valproic acid, sodium butyrate and structural analogs thereof. A preferred inhibitor of histone deacetylase is trichostatin A. Another preferred inhibitor of histone deacetylase is valproic acid. An additional preferred inhibitor of histone deacetylase is sodium butyrate.
In a preferred embodiment of the present invention, the activator of latent HIV expression is prostratin and the inhibitor of histone deacetylase is trichostatin A.
Another surprising finding of this invention is that combinations of prostratin and inhibitors of HDAC act synergistically in a manner that allows use of much lower dose of prostratin; thus, potentially avoiding its toxicity at full dose. Thus, in a preferred embodiment, the amount of prostratin contacting the mammalian cell is less than 10% of an amount of prostratin that is required to obtain the same second expression level in the absence of trichostatin A.
In a preferred embodiment, the mammalian cell is in a human.
In another preferred embodiment the method of activating latent HIV expression in a mammalian cell that is in a human, comprises the step of administering HAART. Alternatively, the method may comprise the step of administering an immunotoxin.
Methods of the present invention may also comprise the step of determining the second expression level, for example, by determining HIV RNA expression or by determining HIV polypeptide expression.
In another preferred embodiment, the method of activating latent HIV expression comprises the step of administering Tat.
All mammalian cells into which HIV integrates can be used to practice the methods of the present invention. In a preferred embodiment, the mammalian cell is a resting lymphoid mononuclear cell, preferably a CD4 + T cell. Preferred is also a CD4 + macrophage. The mammalian cell may also be a myeloid mononuclear cell, preferably a peripheral blood mononuclear cell. Another preferred mammalian cell is a tissue macrophage.
In a further aspect, the present invention provides pharmaceutical compositions. A preferred pharmaceutical composition for eliminating a latent HIV reservoir in a mammalian cell comprises (i) an activator of latent HIV expression, (ii) an inhibitor of histone deacetylase, and (iii) a pharmaceutically acceptable carrier.
In another aspect, the present invention provides for the use of an activator of latent HIV expression and an inhibitor of histone deacetylase in the manufacture of a medicament, which can be used to eliminate a latent HIV reservoir in a mammalian cell.
In yet another aspect, the present invention provides kits. Kits of the invention can be used to practice the methods of the invention. A kit for eliminating a latent HIV reservoir in a mammalian cell comprises (i) a first container containing an activator of latent HIV expression, (ii) a second container containing an inhibitor of histone deacetylase, and (iii) an instruction for using the activator of latent HIV expression and the inhibitor of histone deacetylase for eliminating the latent HIV reservoirs in the cell.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 shows that TSA synergizes with prostratin to activate latent HIV expression. A. Expression of latent HIV expression is induced in J-Lat 6.3 cells. B. Expression of latent HIV expression is induced and in J-Lat 8.4 cells. TSA was used at a concentration of 100 nM and prostratin at a concentration of 2 μM, respectively. C. Low concentrations of prostratin are sufficient to activate latent HIV expression when coadministered with TSA. TSA and prostratin were used at the concentrations indicated. Activation of latent HIV expression was determined as % of GFP-positive cells. Unstim, unstimulated. Details are described in Example 2.
FIG. 2 shows that administration of TSA reduces prostratin-induced cell death. A. Administration of TSA reduces prostratin-induced cell death in J-Lat 6.3 cells. B. Administration of TSA reduces prostratin-induced cell death in J-Lat 8.4 cells. In A. and B., TSA was used at a concentration of 100 nM and prostratin at a concentration of 2 μM, respectively. C. Administration of TSA reduces prostratin-induced cell death in J-Lat 6.3 cells over a wide range of prostratin concentrations. TSA and prostratin were used at the concentrations indicated. Cell viability is indicated as % FsC×SSC. Unstim, unstimulated. Details are described in Example 3.
FIG. 3 shows that valproic acid (VpA) synergizes with prostratin to activate latent HIV expression in J-Lat 6.3 cells. HIV expression was determined as % of GFP-positive cells. VpA and prostratin were used at the concentrations indicated. un, unstimulated. Details are described in Example 4.
FIG. 4 shows that administration of valproic acid (VpA) reduces prostratin-induced cell death. Cell viability (expressed as viability (% FSC×SSC) was determined as in FIG. 2 . VpA and prostratin were used at the concentrations indicated. Details are described in Example 5.
FIG. 5 shows that Tat synergizes with TNF or TSA to activate latent HIV expression in J-Lat 6.3 cells. Tat additionally synergizes with temporally limited induction of NF-κB by transient stimulation with TNF-α (30 minute-pulse followed by wash). HIV expression was determined as % of GFP-positive cells. J-Lat 6.3 cells were either transfected with an empty CMV expression plasmid (CMV) or with a CMV expression plasmid encoding FLAG-Tat (FLAG-Tat) as indicated. Unstim, unstimulated. Details are described in Example 6.
FIG. 6 shows that TNF or TSA synergizes with Tat to activate latent HIV expression in J-Lat 9.2 cells. Tat additionally synergizes with temporally limited induction of NF-κB by transient stimulation with TNF-α (30 minute-pulse followed by wash). HIV expression was determined as % of GFP-positive cells. J-Lat 6.3 cells were either transfected with an empty CMV expression plasmid (CMV) or with a CMV expression plasmid encoding FLAG-Tat (FLAG-Tat) as indicated. Unstim, unstimulated. Details are described in Example 6.
FIG. 7 shows a model for activation of latent HIV expression. A. Latent HIV status. Histone deacetylase 1 (HDAC1) binds to NF-κB p50 homodimer which binds to the proximal enhancer region within the 5′ HIV LTR. HDAC1 is at least one of the HDACs that is recruited to the HIV LTR and removes acetyl groups from histones. Nuc-1 represents a repressive nucleosome preventing recruiting RNA polymerase II. B. Activation of latent HIV expression. Prostratin leads to the nuclear translocation of NF-κB (shown here as p50/RelA heterodimer complex), binding to the proximal enhancer region and displacing the HDAC1/p50/p50 complex. Following a remodeling of the nucleosomes involving acetylation (Ac), RNA polymerase II is recruited to the TATA box, initiates transcription and elongates HIV transcripts. C. TSA inhibits HDAC1, leading to the recruitment of RNA polymerase to the latent HIV LTR. This bound polymerase complex, however, remains non-processive, generating only short viral transcripts. (see, Williams et al., 2006, EMBO J 25:139-149). The following abbreviations are used: Nuc-0, nuc-1, nucleosomes flanking the HIV LTR region; HDAC1, histone deacetylase 1; p50, subunit of NF-κB dimer; RelA, p65 subunit of NF-κB protein; κ B, binding site for NF-κB dimer and p50/RelA proteins in the HIV LTR enhancer region; TATA, binding site of transcription factors initiating transcription at position +1; RNA Pol II, RNA polymerase II, a complex of transcription factors capable of initiating transcription initiation; Ac, acetylation of a Histone; P, indicating chain elongation of an RNA transcript; TSA, trichostatin A. A RNA hairpin loop (TAR) formed at the 5′ termini of nascent HIV transcripts is indicated. Tat, when present binds to TAR and upregulates HIV gene expression.
DETAILED DESCRIPTION OF THE INVENTION
I. Definitions
Unless defined otherwise, all technical and scientific terms used herein have the meaning commonly understood by a person skilled in the art to which this invention belongs. The following references provide one of skill with a general definition of many of the terms used in this invention: Singleton et al., Dictionary of Microbiology and Molecular Biology (2nd ed. 1994); The Cambridge Dictionary of Science and Technology (Walker ed., 1988); The Glossary of Genetics, 5th Ed., R. Rieger et al. (eds.), Springer Verlag (1991); and Hale & Marham, The Harper Collins Dictionary of Biology (1991). As used herein, the following terms have the meanings ascribed to them unless specified otherwise.
As used herein, “activator of latent HIV expression” means any compound that (i) can stimulate proviral latent DNA integrated into the genome of a host to begin transcription initiation, transcription elongation or replication and production of infectious virus and/or cell surface antigens, such as gp120 and/or gp41; and (ii) has a synergistic effect when co-administered with an HDAC inhibitor.
As used herein, “biological sample” means a sample of biological tissue or fluid that contains nucleic acids or polypeptides. Such samples are typically from humans, but include tissues isolated from non-human primates, or rodents, e.g., mice, and rats. Biological samples may also include sections of tissues such as biopsy and autopsy samples, frozen sections taken for histological purposes, blood, plasma, serum, sputum, stool, tears, mucus, hair, skin, etc. Biological samples also include explants and primary and/or transformed cell cultures derived from patient tissues. A “biological sample” also refers to a cell or population of cells or a quantity of tissue or fluid from an animal. Most often, the biological sample has been removed from an animal, but the term “biological sample” can also refer to cells or tissue analyzed in vivo, i.e., without removal from the animal. Typically, a “biological sample” will contain cells from the animal, but the term can also refer to noncellular biological material, such as noncellular fractions of blood, saliva, or urine, that can be used to measure expression level of a polynucleotide or polypeptide. Numerous types of biological samples can be used in the present invention, including, but not limited to, a tissue biopsy or a blood sample. As used herein, a “tissue biopsy” refers to an amount of tissue removed from an animal, preferably a human, for diagnostic analysis. “Tissue biopsy” can refer to any type of biopsy, such as needle biopsy, fine needle biopsy, surgical biopsy, etc. A “biological sample” encompasses samples that have been manipulated in any way after their procurement, such as by treatment with reagents; washed; or enrichment for certain cell populations, such as CD4 + T lymphocytes, glial cells, macrophages, tumor cells, peripheral blood mononuclear cells (PBMC), and the like. The term “biological sample” encompasses a clinical sample, and also includes cells in culture, cell supernatants, tissue samples, organs, bone marrow, and the like.
As used herein, “providing a biological sample” means to obtain a biological sample for use in methods described in this invention. Most often, this will be done by removing a sample of cells from a subject, but can also be accomplished by using previously isolated cells (e.g., isolated by another person, at another time, and/or for another purpose), or by performing the methods of the invention in vivo. Archival tissues, having treatment or outcome history, will be particularly useful.
As used herein, “effective amount”, “effective dose”, sufficient amount”, “amount effective to”, “therapeutically effective amount” or grammatical equivalents thereof mean a dosage sufficient to produce a desired result, to ameliorate, or in some manner, reduce a symptom or stop or reverse progression of a condition. In some embodiments, the desired result is an increase in latent HIV expression. In other embodiments, the desired result is the complete eradication of a latent HIV reservoir. Amelioration of a symptom of a particular condition by administration of a pharmaceutical composition described herein refers to any lessening, whether permanent or temporary, lasting or transit that can be associated with the administration of the pharmaceutical composition. An “effective amount” can be administered in vivo and in vitro.
The terms “eliminating”, “eradicating” or “purging” are used interchangeably.
The terms “full length viral mRNA” or “full length transcript” are used interchangeably and mean polyadenylated viral mRNA. The TAR sequence forms the leader sequence of the full length viral mRNA. In the presence of Tat, viral RNA is elongated beyond the TAR leader sequence and is polyadenylated into full length viral mRNA. Full length viral mRNA includes both spliced and unspliced mRNA.
As used herein, “HAART” refers to a treatment for HIV infection which is a cocktail of anti-viral drugs known as Highly Active Anti-Retroviral Therapy. HAART includes two reverse transcriptase inhibitors and a protease inhibitor. HAART reduces the viral load in many patients to levels below the current limits of detection, but the rapid mutation rate of this virus limits the efficacy of this therapy (Perrin and Telenti, 1998, Science 280:1871-1873). In addition, HAART is ineffective in treating latent HIV infection.
As used herein “HDAC” means histone deacetylase.
As used herein, “HDAC inhibitor” or “inhibitor of HDAC” means any compound that (i) inhibits the activity of a histone deacetylase (HDAC) and (ii) has a synergistic effect on an activator of latent HIV expression, wherein the synergistic effect results in an increase of transcription initiation or transcription elongation from an HIV genome integrated into the genome of a host, compared to the transcription initiation or transcription elongation obtained with the activator of latent HIV expression alone.
As used herein, “HIV” is used herein to refer to the human immunodeficiency virus. It is recognized that the HIV virus is an example of a hyper-mutable retrovirus, having diverged into two major subtypes (HIV-1 and HIV-2), each of which has many subtypes. However, compounds of the present invention can activate the LTR promoters from all HIV and other retroviruses which are similar to HIV-1 in the LTR region. Thus, the term “HIV” used herein, unless otherwise indicated, refers to any retrovirus which is regulated by an LTR promoter or LTR promoter homologue which shows inhibition of the LTR promoter or LTR promoter homologue by calcium response modifiers.
The terms “individual,” “host,” “subject,” and “patient,” used interchangeably herein, refer to a mammal, including, but not limited to, murines, felines, simians, humans, mammalian farm animals, mammalian sport animals, and mammalian pets. The term includes mammals that are susceptible to infection by an immunodeficiency virus.
As used herein, “individual,” “host,” “subject,” or “patient,” to be treated for a condition or disease by a subject method means either a human or non-human animal in need of treatment for a condition or disease. A preferred condition is a condition affected by or caused by latent HIV infection.
As used herein, the term “isomers” refers to compounds of the present invention that possess asymmetric carbon atoms (optical centers) or double bonds. The racemates, diastereomers, geometric isomers and individual isomers are all intended to be encompassed within the scope of the present invention.
As used herein, “in vitro” means outside the body of the organism from which a cell or cells is obtained or from which a cell line is isolated.
As used herein, “in vivo” means within the body of the organism from which a cell or cells is obtained or from which a cell line is isolated.
As used herein, a “label” or a “detectable moiety” means a composition detectable by spectroscopic, photochemical, biochemical, immunochemical, chemical, or other physical means. For example, useful labels include 3 H, 125 I, 32 P, fluorescent dyes, electron-dense reagents, enzymes (e.g., as commonly used in an ELISA), biotin, digoxigenin, or haptens and proteins or other entities which can be made detectable, e.g., by incorporating a radiolabel into a small molecule compound. A label may be incorporated into a small molecule compound, such as a prostratin, DPP, TSA, or valproic acid at any position.
As used herein, “latency”, “latent”, “latently infected reservoir” or grammatical equivalents thereof refer to the integration of a viral genome or a integration of a partial viral genome within a host cell genome further characterized by (i) the undetectable level of non-spliced viral RNA (<500 copies RNA/ml by a commonly used PCR assay; Chun et al., 1997, Proc Natl Acad Sci USA, 94:13193-13197); (ii) absence of detectable viral production; or (iii) only about 10 5 to 10 6 latently infected CD4 memory T cells in a subject (Williams et al., 2004, J Biol Chem 279(40):42008-42017). “Latency” also means a concept describing (i) an asymptomatic clinical condition; (ii) the state of viral activity within a population of cells, or (iii) the down-regulation or absence of gene expression within an infected cell.
As used herein, “level of a mRNA” in a biological sample refers to the amount of mRNA transcribed from a gene that is present in a cell or a biological sample. The mRNA generally encodes a functional protein, although mutations may be present that alter or eliminate the function of the encoded protein. A “level of mRNA” need not be quantified, but can simply be detected, e.g., a subjective, visual detection by a human, with or without comparison to a level from a control sample or a level expected of a control sample. A preferred mRNA is a HIV mRNA.
As used herein, “level of a polypeptide” in a biological sample refers to the amount of polypeptide translated from a mRNA that is present in a cell or biological sample. The polypeptide may or may not have protein activity. A “level of a polypeptide” need not be quantified, but can simply be detected, e.g., a subjective, visual detection by a human, with or without comparison to a level from a control sample or a level expected of a control sample. A preferred polypeptide is an HIV polypeptide, such as GP 120, reverse transcriptase, Gag polypeptide or its protease-processed products.
As used herein, “LTR” means the Long Terminal Repeat, a sequence repeated at the 5′ and 3′ ends of an HIV genome, which consists of an enhancer and a promoter region for gene expression, a RNA transcription start site, and an untranslated RNA sequence.
As used herein, “non-processive transcription” means initiation with inefficient elongation (transcription complexes pause and drop of the DNA) leading to an abundance of short, non-polyadenylated RNA and only rarely in elongated full length mRNAs. “Processive transcription” means efficient elongation of transcripts leading to high levels of polyadenylated mRNA.
As used herein, “pharmaceutically acceptable” refers to compositions that are physiologically tolerable and do not typically produce an allergic or similar untoward reaction when administered to a subject, preferably a human subject. Preferably, as used herein, the term “pharmaceutically acceptable” means approved by a regulatory agency of a Federal or state government or listed in the U.S. Pharmacopeia or other generally recognized pharmacopeia for use in animals, and more particularly in humans.
As used herein, “reactivated,” or grammatical equivalents thereof, in the context of in vivo reactivated HIV, refers to an HIV that, after a period of latency, becomes transcriptionally active, and in many instances forms infectious viral particles. The term “reactivated,” as used herein in the context of in vitro reactivated HIV in a subject cell, refers to an HIV (e.g., a recombinant HIV) that, after a period of latency, becomes transcriptionally active, i.e., a functional Tat protein mediates transcription from a functional HIV promoter (e.g., a long terminal repeat promoter).
As used herein, the term “salts” refers to salts of the active compounds of the present invention, such as activators of latent HIV expression or HDAC inhibitors, which are prepared with relatively nontoxic acids or bases, depending on the particular substituents found on the compounds described herein. When compounds of the present invention contain relatively acidic functionalities, base addition salts can be obtained by contacting the neutral form of such compounds with a sufficient amount of the desired base, either neat or in a suitable inert solvent. Examples of pharmaceutically acceptable base addition salts include sodium, potassium, calcium, ammonium, organic amino, or magnesium salt, or a similar salt. When compounds of the present invention contain relatively basic functionalities, acid addition salts can be obtained by contacting the neutral form of such compounds with a sufficient amount of the desired acid, either neat or in a suitable inert solvent. Examples of pharmaceutically acceptable acid addition salts include those derived from inorganic acids like hydrochloric, hydrobromic, nitric, carbonic, monohydrogencarbonic, phosphoric, monohydrogenphosphoric, dihydrogenphosphoric, sulfuric, monohydrogensulfuric, hydriodic, or phosphorous acids and the like, as well as the salts derived from relatively nontoxic organic acids like acetic, propionic, isobutyric, maleic, malonic, benzoic, succinic, suberic, fumaric, mandelic, phthalic, benzenesulfonic, p-tolylsulfonic, citric, tartaric, methanesulfonic, and the like. Also included are salts of amino acids such as arginate and the like, and salts of organic acids like glucuronic or galactunoric acids and the like (see, for example, Berge, S. M., et al, “Pharmaceutical Salts”, Journal of Pharmaceutical Science, 1977, 66, 1-19). Certain specific compounds of the present invention contain both basic and acidic functionalities that allow the compounds to be converted into either base or acid addition salts.
The neutral forms of the compounds may be regenerated by contacting the salt with a base or acid and isolating the parent compound in the conventional manner. The parent form of the compound differs from the various salt forms in certain physical properties, such as solubility in polar solvents, but otherwise the salts are equivalent to the parent form of the compound for the purposes of the present invention.
As used herein, the term “solvate” refers to compounds of the present invention that are complexed to a solvent. Solvents that can form solvates with the compounds of the present invention include common organic solvents such as alcohols (methanol, ethanol, etc.), ethers, acetone, ethyl acetate, halogenated solvents (methylene chloride, chloroform, etc.), hexane and pentane. Additional solvents include water. When water is the complexing solvent, the complex is termed a “hydrate.”
As used herein, “TAR” means the Trans-Activating Response element which is the target for Tat binding. The TAR region is the first 59-61 nt of the nascent RNA, the leader sequence positioned immediately 3′ of the transcription start site. It forms a stem-loop structure.
As used herein, “Tat” means the virally encoded trans-activating protein which functions as an elongation factor. Tat is essential for viral replication as the key viral element for increasing HIV gene expression.
As used herein, “transcription competent” in the context of transcription-competent latent HIV, refers to a latent HIV (including latent HIV-based retroviral vectors) that encodes functional Tat and has a functional TAR site in the LTR.
As used herein, the terms “treat”, “treating”, and “treatment” include: (1) preventing a condition or disease, i.e. causing the clinical symptoms of the condition or disease not to develop in a subject that may be predisposed to the condition or disease but does not yet experience any symptoms of the condition or disease; (2) inhibiting the condition or disease, i.e. arresting or reducing the development of the condition or disease or its clinical symptoms; or (3) relieving the condition or disease, i.e. causing regression of the condition or disease or its clinical symptoms. These terms encompass also prophylaxis, therapy and cure. Treatment means any manner in which the symptoms or pathology of a condition, disorder, or disease are ameliorated or otherwise beneficially altered. Preferably, the subject in need of such treatment is a mammal, more preferable a human.
II. Small Molecule Compositions
Applicants describe herein novel approaches for eliminating a latent HIV reservoir, wherein expression of the latent HIV is activated by the synergistic action of an activator of latent HIV expression and an HDAC inhibitor. As described herein, it is an objective of the present invention to provide activators of latent HIV expression and HDAC inhibitors useful to practice the methods of the present invention. Thus, the present invention provides compositions and methods that are useful in a wide range of methods. These methods include, but are not limited to, a method for activation of latent HIV expression, a method for eliminating a latent HIV reservoir, a method for increasing latent HIV gene expression, a method for rendering a latent HIV sensitive to killing by an immunotoxin or HAART; a method for treating HIV latency; and a method for increasing the activity of an LTR promoter in a T cell. This invention discloses the surprising finding that inhibitors of histone deacetylase (HDAC) synergize the effect of an activator of latent HIV expression. The compounds and composition disclosed herein can be used in either method described herein.
The inhibitors of histone deacetylase and the activators of latent HIV expression contemplated for use in the methods of the present invention will be described in detail below. In addition, the salts, hydrates, solvates, isomers, prodrugs, and structural analogs of these compounds d also contemplated.
A. Inhibitors of Histone Deacetylase
As described herein, one explanation for the low level of HIV transcription during postintegration latency may be the presence of repressive nucleosomes (see FIG. 7A ) and the presence of histone deacetylases (HDAC) contributing to transcription silencing or repression. Thus, in a preferred embodiment, a composition comprises an inhibitor of HDAC.
In accordance with the preceding embodiments, the histone deacetylase inhibitor may be any molecule that effects a reduction in the activity of a histone deacetylase. This includes proteins, peptides, DNA molecules (including antisense), RNA molecules (including RNAi and antisense) and small molecules.
The small molecule HDAC inhibitors include, but are not limited to, trichostatin A, butyric acid, phenylbutyrate, phenylacetate, trapoxin B (porphrin derivative, C 33 H 30 N 4 O 6 , Kijima et al., 1993, J Biol Chem 268(30):22429-35), MS 275-27 (benzamide derivative, C 21 H 20 N 4 O 3 ), hydroximates (e.g., suberoylanilide hydroxamic acid [SAHA, hydroxamic acid, C 14 H 20 N 2 O 3 , Butler et al., 2000, Cancer Res 60:5165-5170; Marks et al., Clin Cancer Res 7:759-760; Richon et al., 1998, Proc Natl Acad Sci USA, 95(6):3003-7]; azelaic bishydroxamic acid [ABHA, Parsons et al., 2002, Biochem Pharmacol 53:1719-1724]; suberic bishydroxamic acid [SBHA]; m-carboxycinnamic acid bis-hydroxamide [CBHA, hydroxamic acid, C 14 H 20 N 2 O 3 , Coffey et al., 2001, Cancer Res 61:3591-3594]), depudecin (fungal metabolite, C 11 H 16 O 4 ), oxamflatin (aromatic sulfonamide, C 18 H 14 N 2 O 4 S 1 ), apicidin (cyclo(N-O-methyl-L-tryptophanyl-L-isoleucine-D-pipecolinyl-1-2-amino-8-oxodecanoyl, cyclopeptide C 29 H 38 N 5 O 6 ), Scriptaid (hydroxamic acid, C 18 H 12 N 2 O 4 ), pyroxamide (suberoyl-3-aminopyridineamide hydroxyamic acid, C 13 H 20 N 3 O 3 , Butler et al., 2001, Clin Cancer Res 7:962-970), 2-amino-8-oxo-9,10-epoxy-decanoyl (AEO, ketone, C 10 H 17 NO 3 ), 3-(4-aroyl-1H-pyrrol-2-yl)-N-hydroxy-2-propenamide (propenamide, C 14 H 12 N 2 O 3 ), CI-994 (N-acetyldinaline; Kraker et al., 2003, Mol Cancer Ther 2(4):401-8; el-Beltagi et al., 1993, Cancer Res 53:3008-14; commercially available from Pfizer), CHAP1 (trichostatin A+trapoxinB, hydroxamic/porphyrin derivatives), CHAP31 (Furumai et al., 2001, Proc Natl Acad Sci USA 98:97-92; Komatsu et al., 2001, Cancer Res 61(11):4459-66; commercially available from Japan Energy Corporation); CHAP50 (Furumai et al., 2001, Proc Natl Acad Sci USA 98:97-92,; Komatsu et al., 2001, Cancer Res 61(11):4459-66; commercially available from Japan Energy Corporation), MS-275 (Suzuki et al., 1999, J Med Chem 42:3001-3; commercially available from Mitsui Pharmaceuticals, Inc.), M344 (Jung et al., 1999, J Med Chem 42:4669-4679), LAQ-824 (Catley et al., 2003, Blood 102(7):2615-22), FR901228 (cyclopeptide, C 24 H 36 N 4 O 6 S 2 ), FK228 (depsipeptide, Darkin-Rattray et al., 1996, Proc Natl Acad Sci USA 93(23):13143-7) and HC-toxin (Brosch et al., 1995, Plant Cell ( 11):1941-50). Additionally, the following references describe histone deacetylase inhibitors which may be selected for use in the current invention: AU 9,013,101; AU 9,013,201; AU 9,013,401; AU 6,794,700; EP 1,233,958; EP 1,208,086; EP 1,174,438; EP 1,173,562; EP 1,170,008; EP 1,123,111; JP 2001/348340; U.S. 2002/103192; U.S. 2002/65282; U.S. 2002/61860; WO 02/51842; WO 02/50285; WO 02/46144; WO 02/46129; WO 02/30879; WO 02/26703; WO 02/26696; WO 01/70675; WO 01/42437; WO 01/38322; WO 01/18045; WO 01/14581; Furumai et al. 2002, Cancer Res 62:4916-21; Hinnebusch et al., 2002, J Nutr 132:1012-7; Mai et al., 2002, J Med Chem 45:1778-1784; Vigushin et al., 2002, Anticancer Drugs 13:1-13; Gottlicher et al., 2001, EMBO J 20:6969-78; Jung, 2001, Curr Med Chem 8:1505-11; Komatsu et al., 2001, Cancer Res 61:4459-66; Su et al., 2000, 60:3137-3142.
This invention discloses that histone deacetylase inhibitors synergize with an activator of latent HIV expression, such as prostratin, to activate latent HIV expression. Further, this invention discloses that histone deacetylase inhibitors block or reduce prostratin-induced cell death.
1. Trichostatin A
In a preferred embodiment of the present invention, a histone deacetylase inhibitor is trichostatin A (TSA). TSA is a hydroxamic acid, [R-(E,E)]-7-[4-(Dimethylamino)phenyl]-N-hydroxy-4,6-dimethyl-7-oxo-2,4-heptadienamide). It his commercially available (BIOMOL Research Labs, Inc., Plymouth Meeting, Pa. and Wako Pure Chemical Industries, Ltd).
2. Valproic Acid
Another preferred histone deacetylase inhibitor is valproic acid (VpA). VpA is 2-propylpentanoic acid,
Valproic acid, valproate sodium, and divalproex belong to a group of medicines called anticonvulsants that are currently marketed to control certain types of seizures in the treatment of epilepsy. Valproic acid is marketed as “Depakene” (Abbott Laboratories). Divalproex is marketed as “Depakote” (Sanofi-Aventis for UK; Abbott Laboratories for U.S.) and as “Epival” (Abbott Laboratories for Canada). Valproate sodium is marketed as “Depacxon.”
Divalproex and valproate sodium form valproic acid in the body. Divalproex is available for oral administration as delayed-release capsules (in U.S., United States of America) and delayed-release tablets (in U.S. and Canada). VpA is also available for oral administration as capsules (U.S.) and as syrup (in U.S. and Canada). Valproate sodium is used for parenteral administration (injection) in the U.S.
Here, Applicants describe a novel use of VpA, Divalproex and valproate sodium in the methods of the present invention. Thus, in a preferred embodiment of a method of the present invention, Divalproex or valproate sodium is coadministered with an activator of latent HIV activation.
VpA is rapidly absorbed after oral administration. Peak serum levels occur approximately 1 to 4 hours after a single oral dose. The serum half-life of VpA is typically in the range of 6-16 hours.
3. Butyric Acid
Another preferred HDAC inhibitor is butyric acid, preferably sodium butyrate. Preferably, butyric acid is in the form of arginine butyrate or isobutyramide. Butyric acid is one of many naturally-occurring short-chain fatty acids that are generated in the small and large bowel by metabolism of carbohydrates. Butyrate is a four-carbon fatty acid with weakly acidic properties, and is rapidly absorbed and metabolized. Butyrates have shown significant anti-tumor effects. Sodium butyrate (NaB) has been used clinically in patients with acute myelogenous leukemias and there has now been extensive experience with arginine butyrate, a salt of butyrate, in clinical studies for the treatment of β-hemoglobinopathies, and more recently with refractory solid neoplasms (Foss et al., 1994, Proc. ASCO 13:162; Sanders et al., Proc. ASCO, 1995).
In another preferred embodiment of the present invention, a histone deacetylase inhibitor is a small interfering RNA (siRNA), for example, a si/shRNA directed against HDAC1, 2, 3, 4, 5, 6, 7, 8, 9, 10, or 11.
The activity of an HDAC inhibitor may be measured as described herein. An HDAC inhibitor may have an inhibitory effect against at least one class I HDAC or against at least one class II HDAC or against at least one class I and at least one class II HDAC.
B. Activators of Latent HIV Expression
Several activators of latent HIV expression can be used in the compositions and methods of the present invention. A preferred composition of the invention comprises a small molecule that activates latent HIV expression, such as prostratin, DPP and some NF-κB inducers. In another embodiment, an activator of latent HIV expression is a polypeptide, such as NF-κB, Tat, or NF-AT.
1. Prostratin
A preferred activator of latent HIV expression is prostratin (12-deoxyphorbol 13-acetate). Prostratin is a relatively polar, non-tumorigenic phorbol ester, identified in extracts of Homalanthus nutans , a tropical plant used in Samoan herbal medicine primarily for the treatment of jaundice) and stimulates protein kinase C (PKC; Gustafson et al., 1992, J Med Chem 35(11):1978-86).
2. DPP
Another preferred activator of latent HIV expression is 12-deoxyphorbol 13-phenylacetate (DPP; Bocklandt et al., 2003, Antiviral Res 59(2):89-98; Kulkjosky et al., 2004, AIDS Res Hum Retroviruses 20(5):497-505). DPP has been reported to be 20-40 fold more potent than prostratin, probably due to its more lipophilic side chain structure (Bocklandt et al., 2003, Antiviral Res 59(2):89-98).
3. Pro-Dugs and Derivatives
This invention also contemplates for use in the methods, kits and compositions described herein the use of natural pro-drugs of prostratin, which may be identified in extracts from Homalanthus nutans using methods known in the art and assays described herein.
Further, this invention also contemplates for use in the methods, kits and compositions described herein derivatives of prostratin and DPP, which may be prepared chemically using methods known in the art and tested for synergism with n HDAC inhibitor, for example, by employing assays described herein.
4. NF-κB Inducers
NF-κB and transcription factor Sp1 have been demonstrated to be key factors in stimulating replication of HIV, since viruses lacking binding sites for either transcription factor display attenuated replicative capacity (Leonard et al., 1989, J Virol 63:4919-4924). It has been proposed that the absence of NF-κB in the nuclei of latently infected CD4 lymphocytes could play a key role in promoting or maintaining proviral latency in this lymphocyte subset (Williams et al., 2004, J Biol Chem 279(40):42008-42017). As described herein, one explanation for the low level of HIV transcription during postintegration latency may be the absence of the inducible transcription factor NF-κB. Thus, in certain embodiments of the present invention, an NF-κB inducer is co-administered with an HDAC inhibitor.
a) Prostratin
As reported by Williams et al. and by Rullas et al., prostratin antagonizes HIV latency by activating NF-κB (see FIG. 7B ; Williams et al., 2004, J Biol Chem 279(40):42008-42017; Rullas et al., 2004, Antivir Ther 9(4):545-54). Thus, in a preferred embodiment of the present invention, a NF-κB inducer is prostratin. Another preferred NF-κB inducer is prostratin succinate sodium (unpublished studies from S Williams).
b) TNF-alpha
Another preferred NF-κB inducer is TNF-alpha (TNFα; Osborn et al., 1989, Proc Natl Acad Sci USA 86(7):2336-40; Israel et al., 1989, EMBO J 86(7):2336-40).
c) PMA
Another preferred NF-κB inducer, particularly for in vitro assays, is 4-α-phorbol 12-myristate 13-acetate (PMA; Sen et al., 1986, Cell 47(6):921-8). Due to its tumor-inducing activity, the in vivo use of PMA may be limited, particularly in humans.
d) Other NF-κB Inducers
Several other NF-κB inducers can be used to practice the methods of the present invention. Thus, other preferred NF-κB inducers include, but are not limited to TNF-beta (Messer et al., 1990, Cytokine 2(6):389-97); IL-1beta (Osborn et al., 1989 Proc Natl Acad Sci USA 86(7):2336-40); lipopolysaccharide (Sen et al., 1986 Cell 47(6):921-8); UV-light (Stein et al., 1989, Mol Cell Biol 9(11):5169-81); CD3 antibodies (Tong-Starkesen et al., 1989, J Immunol 142(2):702-7); CD3/CD28 antibodies in conjunction (Tong-Starkesen et al., 1989 J Immunol 142(2):702-7); Etopiside (Bessho et al., 1999, Anticancer Res 19(1B):693-8); Daunorubicin (Wang et al., 1996, Science 274(5288):784-7); hydrogen peroxide (Shreck et al., 1991, EMBO J 10(8):2247-58); Nocodazole (Rosette et al., 1995, J Cell Biol 128(6):1111-9); LIGHT (Zou et al., 2005, J Cell Physiol 205(3):437-43); bleomycin (Ishii et al., 2002, Toxicol Appl Pharmicol 184(2):88-97); camptothecin (Piret et al., 1996 Nucleic Acids Res 24(21):4242-8); cisplatin (Nie et al., 1998, Mol Pharmacol 53(4):663-9); celecoxib (Kim et al., 2004, J Cancer Res Clin Oncol 130(9):551-60); ciprofibrate (Li et al., 1996, Carcinogenesis 17(11):2305-9); cycloprodigiosin (Teshima et al., 2004, Nitric Oxide 11(1):9-16); dacarbazine (Lev et al., 2003, Mol Cancer Ther 2(8):753-63); Daio-Orengedeokuto (Cho et al., 2004, Can J Physiol Pharmacol 82(6):380-6); daunomycin (Das et al., 1997, J Biol Chem 272(23):14914-20); diazoxide (Eliseev et al., 2004, J Biol Chem 279(45):46748-54); diclofenac (Cho et al., 2005, FEBS Lett 579(20):4213-8); 5,6-dimethylxanthenone-4-acetic acid (Ching et al., 1999, Biochem Pharmacol 58(7):1173-81); flavone-8-acetic acid (Ching et al., 1999, Biochem Pharmacol 58(7):1173-81); haloperidol (Post et al., 1998, J Neurosci 18(20):8236-46); imiquimod (Schon et al., 2006, Expert Opin Ther Targets 10(1):69-76); isochamaejasmin (Tian et al., 2005, Mol Pharmacol 68(6):1534-42); Kunbi-Boshin-Hangam-Tang (Koo et al., 2001, Immunopharmacol Immunotoxicol 23(2):175-86); lithium (Nemeth et al., 2002, J Biol Chem 277(10):7713-9); mitoxantrone (Boland et al., 2000, J Biol Chem 275(33):25231-8); morphine (Yin et al., J Neuroimmunol 2006 Mar. 7 [Epub ahead of print]); nipradilol (Ando et al., 2005, Exp Eye Res 80(4):501-7); norepinephrine (Minneman et al., 2000, J Neurochem 74(6):2392-400); nystatin (Ogawa et al., 2006, J Invest Dermatol 126(2):349-53); oltipraz (Nho et al., 2004, J Biol Chem 279(25):26019-27); protocatechuic acid (Zhou-Stache et al., 2002, Med Biol Eng Comput 40(6):698-703); SN38 (metabolite of CPT-11; Kishida et al., 2005, Cancer Chemother Pharmacol 55(4):393-403); tamoxifen (Ferline et al., 1999, Br J Cancer 79(2):257-63); Taxol (Paclitaxel; Hwang et al., 1995, Cancer Biochem Biophys 14(4):265-72); vinblastine (Rosette et al., 1995, J Cell Biol 128(6):1111-9); vincristine (Das et al., 1997, J Biol Chem 272(23):14914-20); and WR1065 (Grdina et al., 2002, Mil Med 167(2 Suppl):51-3).
5. Tat
As described herein, one explanation for the low level of HIV transcription during postintegration latency may be the absence of the inducible transcription factor Tat. TSA has been shown to inhibit HDAC, leading to the recruitment of RNA polymerase to the latent HIV LTR. This bound polymerase complex, however, remains non-processive, generating only short viral transcripts (see FIG. 7 C). Synthesis of full-length viral transcripts can be rescued by the viral transactivator protein Tat (Williams et al., 2006, EMBO J 25:139-149). Thus, in certain embodiments of the present invention, a method comprises the step of administering Tat to a cell or to a subject. In another embodiment of the present invention, a composition comprises Tat.
In one embodiment of the invention, the Tat is a recombinant Tat. The basic molecular biological techniques employed in generating a recombinant Tat, i.e., methods such as DNA and plasmid isolation, restriction enzyme digestion, DNA ligation, purification and characterization of DNAs by polyacrylamide and agarose gel electrophoresis, labeling and hybridization of DNAs, Southern blotting, transformation, maintenance and growth of bacterial strains, protein expression and protein purification, and other general techniques are all well known in the literature. Specifically, the general techniques of molecular biology are described in “Molecular Cloning A Laboratory Manual” by Sambrook, J., Fritsch, E. F., and Maniatis, T. published by Cold Spring Harbor Laboratory Press, 2nd edition, 1989, or “A Practical Guide to Molecular Cloning” by Bernard Perbal published by John Wiley & Sons, New York, 1984.
Generally, the DNA encoding Tat is cloned into an expression vector and transformed into a suitable host cell, which expresses the recombinant Tat. The recombinant Tat may then be purified using methods known to the skilled artisan.
Alternatively, a composition of the present invention comprises a plasmid construct encoding Tat.
6. NF-AT
As described herein, one explanation for the low level of HIV transcription during postintegration latency may be the absence of the inducible transcription factor NF-AT (nuclear factor of activated T cells). Activation of latent HIV gene expression by NF-AT seems to be independent from the NF-κB activation pathway (Brooks et al., 2003, Proc Natl Acad Sci USA, 100(22):12955-12960). Thus, in certain embodiments of the present invention, a method comprises the step of administering NF-AT to a cell or to a subject. In another embodiment of the present invention, a composition comprises NF-AT. In yet another embodiment, a method comprises the step of administering a small a NF-AT inducer. In another preferred embodiment of the present invention, a composition comprises a NF-AT inducer which induces NF-AT in a cell.
7. Additional Activators of Latent HIV Expression
Additional activators of latent HIV expression can be identified routinely. For example, the J-Lat cell lines described herein and other established cell lines harboring latent HIV, such as OM-10.1, U1, or Jurkat cells, can be treated with various amount of an agent, e.g., an agent from a combinatorial chemical library to determine effective doses and conditions for obtaining productive HIV infection.
C. Testing Inhibitors of Histone Deacetylase and Activators of Latent HIV Expression
The small molecules described herein and agents derived therefrom through routine chemical manipulations that are useful for purging a latent HIV reservoir can be tested for their potential to activate latent HIV expression using the assays described herein. Other useful assays have been described in the art. For example, the small molecules described herein can be tested for induction of HIV expression in patient peripheral blood mononuclear cell (PBMC) cultures obtained from HIV infected individuals (e.g., Kulkosky et al., 2001, Blood 98(10):3006-15). Alternatively, the activation potential of the small molecules can be evaluated testing for reactivation of latent HIV infection from thymocytes and peripheral blood lymphocytes (PBLs) in the severe combined immunodeficient mouse containing human fetal thymus and liver cells (SCID-hu [Thy/Liv] mouse; Brooks et al., 2001, Nat Med 7:459-464; Korin et al., 2002, J Virol 76(16):8118-23).
In addition, the small molecules described herein and agents derived therefrom through routine chemical manipulations that are useful for purging a latent HIV reservoir can be tested for their potential to activate latent HIV expression by real time PCR detecting viral transcripts as described herein and as known in the art.
HDAC inhibitors described herein and agents derived therefrom through routine chemical manipulations that are useful for purging a latent HIV reservoir can be tested in chromatin immunoprecipitation assays measuring their capability to deacetylate the HIV promoter as described (Ylisastigui et al., 2004, AIDS 18(8):1101-8; Williams et al., 2004, J Biol Chem 279(40):42008-42017). The effect of HDAC inhibitors on resting CD4 + T cell phenotype can be measured by flow cytometric analysis (Ylisastigui et al., 2004, AIDS 18(8):1101-8).
Other HDAC inhibitors and agents derived therefrom through routine chemical manipulations may also be tested in the presence and absence of a candidate substance, such as a histone with a labeled acetyl group. For example, a method generally comprises: (a) providing a candidate HDAC inhibitor, (b) combining the candidate HDAC inhibitor with an HDAC; (c) measuring HDAC activity, and (d) comparing the activity in step (c) with the activity in the absence of the candidate HDAC inhibitor, wherein a lower measured activity in (b) when compared to the measured activity without the candidate HDAC inhibitor indicates that the candidate HDAC inhibitor is, indeed an HDAC inhibitor.
III. Synergistic Effect of Inhibitors of Histone Deacetylase and Activators of Latent HIV Expression
The compounds of the present invention, inhibitors of HDAC and activators of latent HIV expression find use in a variety of ways. The present invention discloses the surprising finding that HDAC inhibitors, such as TSA and valproic acid, which typically have no substantial effect on the expression of latent HIV expression, can potentiate the expression of latent HIV-1 above an expression level obtained by administration of an activator of latent HIV expression, such as prostratin, alone. That is, inhibitors of HDAC synergize with activators of latent HIV expression. Because inhibitors of histone deacetylase synergize with an activator of latent HIV expression, and in particular prostratin, a lower dose of the activator of latent HIV expression can be used to essentially obtain the same or greater effect on activation of latent HIV expression than would be obtained when using the activator of latent HIV expression alone. Thus, using a much lower dose of, for example, prostratin, potentially avoids its toxicity at full dose.
Methods of the present invention can be practiced in vitro and in vivo. In a preferred embodiment, the step of administering a composition according to the present invention is performed in vivo, for example, by an intradermal, intravenous, subcutaneous, oral, aerosol, intramuscular and intraperitoneal route of administration, or ex vivo, for example, by transfection, electroporation, microinjection, lipofection, adsorption, protoplast fusion, use of protein carrying agents, use of ion carrying agents, and use of detergents for cell permeabilization.
A. Method for Activating Latent HIV Expression
In a preferred embodiment the present invention provides a method for activating latent HIV expression in a mammalian cell having an integrated HIV genome, the method comprising the steps of (a) contacting the mammalian cell with an amount of an activator of latent HIV expression effective to activate latent HIV expression to a first expression level; and (b) contacting the mammalian cell with an amount of an inhibitor of histone deacetylase effective to activate the latent HIV expression to a second expression level, wherein the activator of latent HIV expression and the inhibitor of histone deacetylase synergize to generate the second expression level.
In a preferred embodiment of the present invention, the activator of latent HIV expression and the inhibitor of histone deacetylase are used simultaneously for the contacting of the mammalian cell. This can be done by contacting the mammalian cell with a composition comprising both compounds as further described herein. In other embodiments, the activator of latent HIV expression and the inhibitor of histone deacetylase are used sequentially.
In another preferred embodiment the present invention provides a method for activating latent HIV expression in a mammalian cell having an integrated HIV genome, the method comprising the steps of (a) contacting the mammalian cell with an amount of an activator of latent HIV expression effective to activate latent HIV expression; and (b) contacting the mammalian cell with an amount of an inhibitor of histone deacetylase effective to further activate the latent HIV expression, wherein the activation of latent HIV expression after step (b) is greater than the activation of latent HIV expression by step (a) alone; wherein the level of the HIV RNA in the mammalian cell is increased.
The HIV genome is integrated in the genome of the mammalian cell.
It is understood, that this method results in an increase of the activity of an LTR promoter in the mammalian cell leading to a more processive RNA polymerase II complex.
In a preferred embodiment, this method comprises the step of contacting a mammalian cell with an amount of Tat effective to activate latent HIV expression above the level exhibited by steps (a) and (b); wherein the level of the HIV RNA in the mammalian cell is further increased.
In another preferred embodiment, this method comprises the step of contacting a mammalian cell with an amount of NF-κB effective to activate the latent HIV expression above the level exhibited by steps (a) and (b); wherein the level of the HIV RNA in the mammalian cell is further increased.
In a preferred embodiment, the step of contacting a compound or composition of the invention with a mammalian cell is performed by administering the compound or composition to a mammalian cell in a human, preferably a human having a latent HIV infection.
The methods of the present invention can be applied to any cell wherein an HIV genome is integrated into the cellular DNA, preferably a mammalian cell and even more preferred a human cell. A preferred cell is a resting lymphoid mononuclear cell obtained from a mammal including e.g., lymphocytes, such as T cells (CD4, CD8, cytolytic, helper), B cells, natural killer cells; mononuclear phagocytes, such as monocytes, macrophages, epitheloid cells, giant cells, microglia, Kupffer cells, alveolar macrophages; dendritic cells, such as interdigitating dendrite cells, Langerhans cells, or follicular dendritic cells; granulocytes; etc. Preferred is a CD4 + T cell.
In another preferred embodiment, a preferred cell is a myeloid mononuclear cell, preferably, a peripheral blood mononuclear cell or tissue macrophage.
Another surprising finding of this invention is that because of inhibitors of histone deacetylase synergize the effect, an activator of latent HIV expression, and in particular prostratin, has on the activation of latent HIV expression, a lower dose of the activator of latent HIV expression can be used to essentially obtain the same or greater effect on activation of latent HIV expression than would be obtained when using the activator of latent HIV expression alone. Thus in a preferred embodiment, the amount of an activator of latent HIV expression, e.g., prostratin, contacting the mammalian cell is less than 50% of an amount of an activator of latent HIV expression, e.g., prostratin, that is required to obtain the same second expression level in the absence of trichostatin A. In another embodiment the amount of an activator of latent HIV expression, e.g., prostratin, contacting the mammalian cell is less than 25%, preferably less than 20%, preferably less than 10%, more preferably less than 5% and even more preferably less than 2% of an amount an activator of latent HIV expression, e.g., prostratin, that is required to obtain the same second expression level in the absence of trichostatin A.
B. Method for Treating HIV Latency
In a preferred embodiment of the present invention the composition of the invention are used in a method for treating HIV latency. This method can be practiced in vitro. Preferably this method is practiced in vivo. Preferably this method is practiced in a host latently infected with HIV, e.g., a human latently infected with HIV. This method seeks to complete eradicate a latent HIV reservoir in a latently HIV infected subject.
This method comprises the steps of administering to the latently HIV-infected host a therapeutically effective amount of a composition comprising an activator of latent HIV expression and an HDAC inhibitor.
When practiced in vivo, the method, optionally comprises the step of administering HAART. Thus, in yet another embodiment of the present invention, a method of treating a latently HIV-infected host comprises the step of administering highly active antiretroviral therapy (HAART).
According to this embodiment, a composition comprising an activator of latent HIV expression and an HDAC inhibitor may be coadministered with any HAART regimen. The current standard of care using HAART is usually a combination of at least three nucleoside reverse transcriptase inhibitors and frequently includes a protease inhibitors, or alternatively a non-nucleoside reverse transcriptase inhibitor. Patients who have low CD4 + cell counts or high plasma RNA levels may require more aggressive HAART. For patients with relatively normal CD4 + cell counts and low to non-measurable levels of plasma HIV RNA over prolonged periods (i.e. slow or non-progressors) may require less aggressive HAART. For antiretroviral-naive patients who are treated with initial antiretroviral regimen, different combinations (or cocktails) of antiretroviral drugs can be used.
Preferably, a composition comprising an activator of latent HIV expression and an HDAC inhibitor may be coadministered with a “cocktail” of nucleoside reverse transcriptase inhibitors, non-nucleoside HIV reverse transcriptase inhibitors, and protease inhibitors. For example, a composition comprising an activator of latent HIV expression and an HDAC inhibitor may be coadministered with a cocktail of two nucleoside reverse transcriptase inhibitors (e.g. ZIDOVUDINE (AZT) and LAMIVUDINE (3TC)), and one protease inhibitor (e.g. INDINAVIR (MK-639)). A composition comprising an activator of latent HIV expression and an HDAC inhibitor may also be coadministered with a cocktail of one nucleoside reverse transcriptase inhibitor (e.g. STAVUDINE (d4T)), one non-nucleoside reverse transcriptase inhibitor (e.g. NEVIRAPINE (BI-RG-587)), and one protease inhibitor (e.g. NELFINAVIR (AG-1343)). Alternatively, a composition comprising an activator of latent HIV expression and an HDAC inhibitor may be coadministered with a cocktail of one nucleoside reverse transcriptase inhibitor (e.g. ZIDOVUDINE (AZT)), and two protease inhibitors (e.g. NELFINAVIR (AG-1343) and SAQINAVIR (Ro-31-8959)).
Coadministration in the context of this invention is defined to mean the administration of more than one therapeutic in the course of a coordinated treatment to achieve an improved clinical outcome. Such coadministration may also be coextensive, that is, occurring during overlapping periods of time. Further discussion of such conventional treatment can be found in the art (e.g., Gulick, 1997; Qual Life Res 6:471-474; Henry et al., 1997, Postgrad Med 102:100-107; Hicks, 1997, Radiol Clin North Am 35:995-1005; Goldschmidt, 1996, Am Fam Physician 54:574-580).
This regimen is continued for a period past the point when the levels of integrated and unintegrated HIV in active and memory T cells are undetectably low. At the end of the period, the patient is weaned from HAART and from the activators of latent HIV expression and HDAC inhibitors according to the invention. At this point, the patient is monitored for reestablishment of normal immune function and for signs of reemergence of HIV infection. Additionally, any needed conjunctive immunotherapy, such as bone marrow transplants, various cytokines or vaccination, may be administered. After this, the patient is monitored on a routine basis for life to detect reemergence of HIV infection, in which case repeat therapy according to the above preferred embodiment is recommended.
C. Method for Rendering Latent HIV Sensitive to Killing by an Immunotoxin
Several immunotoxins can be employed in this method. A preferred immunotoxin is an immunotoxin targeted to an HIV protein expressed on the exterior of cells, such as the viral envelope glycoprotein or a portion thereof. The term “immunotoxin” refers to a covalent or non-covalent linkage of a toxin to an antibody, such as an anti HIV envelope glycoprotein antibody. The toxin may be linked directly to the antibody, or indirectly through, for example, a linker molecule. A preferred toxin is a toxin selected from the group consisting of ricin-A and abrin-A.
D. General Method
Activation of latent HIV expression (also referred to as reactivation of latent HIV expression) results in the conversion of latently infected cells to productively infected cells. This transition can be measured by any characteristic of active viral infection, e.g., production of infectious particles, reverse transcriptase activity, secreted antigens, cell-surface antigens, soluble antigens, HIV RNA and HIV DNA, etc.
The methods of the present invention described above, may optionally comprise the step of determining or detecting activation of latent HIV expression. In one embodiment, such a method comprises determining or detecting a mRNA, preferably an HIV mRNA. Other mRNAs, such as Tat mRNA, NF-κB mRNA, NF-AT mRNA and other mRNAs encoding polypeptides described herein can also be determined using the following methods.
1. Detection of mRNA
A preferred mRNA is an HIV mRNA. Thus, expression levels of HIV mRNA, may be determined. Detecting a increased expression level of the HIV mRNA relative to the mRNA level present in a latently infected cell indicates activation of the latent HIV expression. In one embodiment, the step of determining the level of the HIV mRNA comprises an amplification reaction. Methods of evaluating mRNA expression of a particular gene are well known to those of skill in the art, and include, inter alia, hybridization and amplification based assays.
a) Direct Hybridization-Based Assays
Methods of detecting and/or quantifying the level of a gene transcript (mRNA or cDNA made therefrom) using nucleic acid hybridization techniques are known to those of skill in the art. For example, one method for evaluating the presence, absence, or quantity of HIV polynucleotides involves a Northern blot. Gene expression levels can also be analyzed by techniques known in the art, e.g., dot blotting, in situ hybridization, RNase protection, probing DNA microchip arrays, and the like (e.g., see Sambrook, J., Fritsch, E. F., and Maniatis, “Molecular Cloning A Laboratory Manual” by T. published by Cold Spring Harbor Laboratory Press, 2nd edition, 1989).
b) Amplification-Based Assays
In another embodiment, amplification-based assays are used to measure the expression level of an HIV gene. In such an assay, the HIV nucleic acid sequences act as a template in an amplification reaction (e.g., Polymerase Chain Reaction, or PCR). In a quantitative amplification, the amount of amplification product will be proportional to the amount of template in the original sample. Comparison to appropriate controls provides a measure of the level of HIV mRNA in the sample. Methods of quantitative amplification are well known to those of skill in the art. Detailed protocols for quantitative PCR are provided, e.g., in Innis et al. (1990) PCR Protocols, A Guide to Methods and Applications , Academic Press, Inc. N.Y.). Exemplary methods using HIV nucleic acids as a template for PCR are described as well (E.g., see (Williams et al., 2004, J Biol Chem 279(40):42008-42017; Williams et al., 2006, EMBO J 25:139-149).
In one embodiment, a TaqMan based assay is used to quantify the HIV polynucleotides. TaqMan based assays use a fluorogenic oligonucleotide probe that contains a 5′ fluorescent dye and a 3′ quenching agent. The probe hybridizes to a PCR product, but cannot itself be extended due to a blocking agent at the 3′ end. When the PCR product is amplified in subsequent cycles, the 5′ nuclease activity of the polymerase, e.g., AmpliTaq, results in the cleavage of the TaqMan probe. This cleavage separates the 5′ fluorescent dye and the 3′ quenching agent, thereby resulting in an increase in fluorescence as a function of amplification (see, for example, Heid et al., 1996, Genome Res 6(10):986-94; Morris et al., 1996, J Clin Microbiol 34(12):2933-6).
Other suitable amplification methods include, but are not limited to, ligase chain reaction (LCR) (see, Wu and Wallace, 1989, Genomics 4:560; Landegren et al., 1988, Science 241:1077; and Barringer et al., 1990, Gene 89:117), transcription amplification (Kwoh et al., 1989, Proc Natl Acad Sci USA 86:1173), self-sustained sequence replication (Guatelli et al., 1990, Proc Nat Acad Sci USA 87: 1874), dot PCR, and linker adapter PCR, etc.
2. Detection of Polypeptide
The methods of the present invention described above, may optionally comprise the step of determining or detecting activation of latent HIV expression. In one embodiment, such a method comprises determining or detecting a polypeptide, preferably an HIV polypeptide or a polypeptide for which the coding region has been inserted into the HIV genome, such as the GFP polypeptide of the J-Lat cell lines described herein and by Jordan et al., (Jordan et al., 2003, EMBO J 22(8):1868-1877). Other polypeptides, such as Tat, NF-κB, NF-AT and others described herein can also be determined using the following methods.
Thus, expression level of an HIV polypeptide may be determined by several methods, including, but not limited to, affinity capture, mass spectrometry, traditional immunoassays directed to HIV proteins (such as gp120 and reverse transcriptase), PAGE, Western Blotting, or HPLC as further described herein or as known by one of skill in the art.
Detection paradigms that can be employed to this end include optical methods, electrochemical methods (voltametry and amperometry techniques), atomic force microscopy, and radio frequency methods, e.g., multipolar resonance spectroscopy. Illustrative of optical methods, in addition to microscopy, both confocal and non-confocal, are detection of fluorescence, luminescence, chemiluminescence, absorbance, reflectance, transmittance, and birefringence or refractive index (e.g., surface plasmon resonance, ellipsometry, a resonant mirror method, a grating coupler waveguide method or interferometry).
3. Determining Latent Viral Load
Methods and compositions for determining latent viral load have been described, e.g., in U.S. Pat. Appl. Publ. 2001/0039007, published Nov. 8, 2001, incorporated herewith by reference in its entirety.
IV. Pharmaceutical Compositions
In one aspect the present invention provides a pharmaceutical composition or a medicament comprising at least an activator of latent HIV expression and an inhibitor of HDAC of the present invention and optionally a pharmaceutically acceptable carrier. A pharmaceutical composition or medicament can be administered to a subject for the treatment of, for example, a condition or disease as described herein.
A pharmaceutical composition may include any combinations of latent HIV activator compounds, HIV transcription activators and HDAC inhibitors.
A. Formulation and Administration
Compounds of the present invention, such as the activators of latent HIV expression and the inhibitors of HDAC described herein, are useful in the manufacture of a pharmaceutical composition or a medicament comprising an effective amount thereof in conjunction or mixture with excipients or carriers suitable for either enteral or parenteral application.
Pharmaceutical compositions or medicaments for use in the present invention can be formulated by standard techniques using one or more physiologically acceptable carriers or excipients. Suitable pharmaceutical carriers are described herein and in “Remington's Pharmaceutical Sciences” by E. W. Martin. The small molecule compounds of the present invention and their physiologically acceptable salts and solvates can be formulated for administration by any suitable route, including via inhalation, topically, nasally, orally, parenterally, or rectally. Thus, the administration of the pharmaceutical composition may be made by intradermal, subdermal, intravenous, intramuscular, intranasal, intracerebral, intratracheal, intraarterial, intraperitoneal, intravesical, intrapleural, intracoronary or intratumoral injection, with a syringe or other devices. Transdermal administration is also contemplated, as are inhalation or aerosol administration. Tablets and capsules can be administered orally, rectally or vaginally.
For oral administration, a pharmaceutical composition or a medicament can take the form of, for example, a tablets or a capsule prepared by conventional means with a pharmaceutically acceptable excipient. Preferred are tablets and gelatin capsules comprising the active ingredient, i.e., a small molecule compound of the present invention, together with (a) diluents or fillers, e.g., lactose, dextrose, sucrose, mannitol, sorbitol, cellulose (e.g., ethyl cellulose, microcrystalline cellulose), glycine, pectin, polyacrylates and/or calcium hydrogen phosphate, calcium sulfate; (b) lubricants, e.g., silica, talcum, stearic acid, its magnesium or calcium salt, metallic stearates, colloidal silicon dioxide, hydrogenated vegetable oil, corn starch, sodium benzoate, sodium acetate and/or polyethyleneglycol; for tablets also (c) binders, e.g., magnesium aluminum silicate, starch paste, gelatin, tragacanth, methylcellulose, sodium carboxymethylcellulose, polyvinylpyrrolidone and/or hydroxypropyl methylcellulose; if desired (d) disintegrants, e.g., starches (e.g., potato starch or sodium starch), glycolate, agar, alginic acid or its sodium salt, or effervescent mixtures; (e) wetting agents, e.g., sodium lauryl sulphate, and/or (f) absorbents, colorants, flavors and sweeteners.
Tablets may be either film coated or enteric coated according to methods known in the art. Liquid preparations for oral administration can take the form of, for example, solutions, syrups, or suspensions, or they can be presented as a dry product for constitution with water or other suitable vehicle before use. Such liquid preparations can be prepared by conventional means with pharmaceutically acceptable additives, for example, suspending agents, for example, sorbitol syrup, cellulose derivatives, or hydrogenated edible fats; emulsifying agents, for example, lecithin or acacia; non-aqueous vehicles, for example, almond oil, oily esters, ethyl alcohol, or fractionated vegetable oils; and preservatives, for example, methyl or propyl-p-hydroxybenzoates or sorbic acid. The preparations can also contain buffer salts, flavoring, coloring, and/or sweetening agents as appropriate. If desired, preparations for oral administration can be suitably formulated to give controlled release of the active compound.
Compounds of the present invention can be formulated for parenteral administration by injection, for example by bolus injection or continuous infusion. Formulations for injection can be presented in unit dosage form, for example, in ampoules or in multi-dose containers, with an added preservative. Injectable compositions are preferably aqueous isotonic solutions or suspensions, and suppositories are preferably prepared from fatty emulsions or suspensions. The compositions may be sterilized and/or contain adjuvants, such as preserving, stabilizing, wetting or emulsifying agents, solution promoters, salts for regulating the osmotic pressure and/or buffers. Alternatively, the active ingredient can be in powder form for constitution with a suitable vehicle, for example, sterile pyrogen-free water, before use. In addition, they may also contain other therapeutically valuable substances. The compositions are prepared according to conventional mixing, granulating or coating methods, respectively, and contain about 0.1 to 75%, preferably about 1 to 50%, of the active ingredient.
For administration by inhalation, the compounds may be conveniently delivered in the form of an aerosol spray presentation from pressurized packs or a nebulizer, with the use of a suitable propellant, for example, dichlorodifluoromethane, trichlorofluoromethane, dichlorotetrafluoroethane, carbon dioxide, or other suitable gas. In the case of a pressurized aerosol, the dosage unit can be determined by providing a valve to deliver a metered amount. Capsules and cartridges of, for example, gelatin for use in an inhaler or insufflator can be formulated containing a powder mix of the compound and a suitable powder base, for example, lactose or starch.
Suitable formulations for transdermal application include an effective amount of a compound of the present invention with carrier. Preferred carriers include absorbable pharmacologically acceptable solvents to assist passage through the skin of the host. For example, transdermal devices are in the form of a bandage comprising a backing member, a reservoir containing the compound optionally with carriers, optionally a rate controlling barrier to deliver the compound to the skin of the host at a controlled and predetermined rate over a prolonged period of time, and means to secure the device to the skin. Matrix transdermal formulations may also be used.
Suitable formulations for topical application, e.g., to the skin and eyes, are preferably aqueous solutions, ointments, creams or gels well-known in the art. Such may contain solubilizers, stabilizers, tonicity enhancing agents, buffers and preservatives.
The compounds can also be formulated in rectal compositions, for example, suppositories or retention enemas, for example, containing conventional suppository bases, for example, cocoa butter or other glycerides.
Furthermore, the compounds can be formulated as a depot preparation. Such long-acting formulations can be administered by implantation (for example, subcutaneously or intramuscularly) or by intramuscular injection. Thus, for example, the compounds can be formulated with suitable polymeric or hydrophobic materials (for example as an emulsion in an acceptable oil) or ion exchange resins, or as sparingly soluble derivatives, for example, as a sparingly soluble salt.
The compositions can, if desired, be presented in a pack or dispenser device that can contain one or more unit dosage forms containing the active ingredient. The pack can, for example, comprise metal or plastic foil, for example, a blister pack. The pack or dispenser device can be accompanied by instructions for administration.
In one embodiment of the present invention, a pharmaceutical composition or medicament comprises an effective amount of an activator of latent HIV expression and an inhibitor of HDAC of the present invention as defined above, and another therapeutic agent, such as a component used for HAART, as described herein. When used with compounds of the invention, such therapeutic agent may be used individually (e.g., a component used for HAART and compounds of the present invention), sequentially (e.g., a component used for HAART and compounds of the present invention for a period of time followed by e.g., a second component used for HAART and compounds of the present invention), or in combination with one or more other such therapeutic agents (e.g., a reverse transcriptase inhibitor used for HAART, a protease inhibitor used for HAART, and compounds of the present invention). Administration may be by the same or different route of administration or together in the same pharmaceutical formulation.
Thus, in a preferred embodiment of the present invention, a pharmaceutical composition comprises (i) an activator of latent HIV expression, (ii) an inhibitor of histone deacetylase, and (iii) a pharmaceutically acceptable carrier.
In another preferred embodiment of the present invention, a pharmaceutical composition comprises (i) an activator of NF-κB or NF-AT, (ii) an inhibitor of histone deacetylase, and (iii) a pharmaceutically acceptable carrier.
B. Therapeutic Effective Amount and Dosing
In one embodiment of the present invention, a pharmaceutical composition or medicament is administered to a subject, preferably a human, at a therapeutically effective dose to prevent, treat, or control a condition or disease as described herein, such as HIV latency. The pharmaceutical composition or medicament is administered to a subject in an amount sufficient to elicit an effective therapeutic response in the subject. An effective therapeutic response is a response that at least partially arrests or slows the symptoms or complications of the condition or disease. An amount adequate to accomplish this is defined as “therapeutically effective dose.”
The dosage of active compounds administered is dependent on the species of warm-blooded animal (mammal), the body weight, age, individual condition, surface area of the area to be treated and on the form of administration. The size of the dose also will be determined by the existence, nature, and extent of any adverse effects that accompany the administration of a particular small molecule compound in a particular subject. A unit dosage for oral administration to a mammal of about 50 to 70 kg may contain between about 5 and 500 mg of the active ingredient. Typically, a dosage of the active compounds of the present invention, is a dosage that is sufficient to achieve the desired effect. Optimal dosing schedules can be calculated from measurements of compound accumulation in the body of a subject. In general, dosage may be given once or more daily, weekly, or monthly. Persons of ordinary skill in the art can easily determine optimum dosages, dosing methodologies and repetition rates.
In one embodiment of the present invention, a pharmaceutical composition or medicament comprising compounds of the present invention is administered in a daily dose in the range from about 0.1 mg of each compound per kg of subject weight (0.1 mg/kg) to about 1 g/kg for multiple days. In another embodiment, the daily dose is a dose in the range of about 5 mg/kg to about 500 mg/kg. In yet another embodiment, the daily dose is about 10 mg/kg to about 250 mg/kg. In another embodiment, the daily dose is about 25 mg/kg to about 150 mg/kg. A preferred dose is about 10 mg/kg. The daily dose can be administered once per day or divided into subdoses and administered in multiple doses, e.g., twice, three times, or four times per day. However, as will be appreciated by a skilled artisan, activators of latent HIV expression and inhibitors of HDAC may be administered in different amounts and at different times.
The recommended initial dose for VpA, in the treatment of seizures (see above), for example, is 15 mg/kg/day orally, increasing at 1-week intervals by 5-10 mg/kg/day until seizures are controlled or side effects preclude further increases. A maximum recommended dose is 60 mg/kg/day. When the total daily dose exceeds 250 mg, it should be given in a divided regimen. A similar dosing regimen may be used for VpA in the methods of the present invention.
To achieve the desired therapeutic effect, compounds may be administered for multiple days at the therapeutically effective daily dose. Thus, therapeutically effective administration of compounds to treat a condition or disease described herein in a subject requires periodic (e.g., daily) administration that continues for a period ranging from three days to two weeks or longer. Typically, compounds will be administered for at least three consecutive days, often for at least five consecutive days, more often for at least ten, and sometimes for 20, 30, 40 or more consecutive days. While consecutive daily doses are a preferred route to achieve a therapeutically effective dose, a therapeutically beneficial effect can be achieved even if the compounds are not administered daily, so long as the administration is repeated frequently enough to maintain a therapeutically effective concentration of the compounds in the subject. For example, one can administer the compounds every other day, every third day, or, if higher dose ranges are employed and tolerated by the subject, once a week. A preferred dosing schedule, for example, is administering daily for a week, one week off and repeating this cycle dosing schedule for 3-4 cycles.
Optimum dosages, toxicity, and therapeutic efficacy of such compounds may vary depending on the relative potency of individual compounds and can be determined by standard pharmaceutical procedures in cell cultures or experimental animals, for example, by determining the LD 50 (the dose lethal to 50% of the population) and the ED 50 (the dose therapeutically effective in 50% of the population). The dose ratio between toxic and therapeutic effects is the therapeutic index and can be expressed as the ratio, LD 50 /ED 50 . Compounds that exhibit large therapeutic indices are preferred. While compounds that exhibit toxic side effects can be used, care should be taken to design a delivery system that targets such compounds to the site of affected tissue to minimize potential damage to normal cells and, thereby, reduce side effects.
The data obtained from, for example, cell culture assays and animal studies can be used to formulate a dosage range for use in humans. The dosage of such small molecule compounds lies preferably within a range of circulating concentrations that include the ED 50 with little or no toxicity. The dosage can vary within this range depending upon the dosage form employed and the route of administration. For any compounds used in the methods of the invention, the therapeutically effective dose can be estimated initially from cell culture assays. A dose can be formulated in animal models to achieve a circulating plasma concentration range that includes the IC 50 (the concentration of the test compound that achieves a half-maximal inhibition of symptoms) as determined in cell culture. Such information can be used to more accurately determine useful doses in humans. Levels in plasma can be measured, for example, by high performance liquid chromatography (HPLC). In general, the dose equivalent of compounds is from about 1 ng/kg to 100 mg/kg for a typical subject.
Following successful treatment, it may be desirable to have the subject undergo maintenance therapy to prevent the recurrence of the condition or disease treated.
V. Kits
For use in diagnostic, research, and therapeutic applications suggested above, kits are also provided by the invention. In the diagnostic and research applications such kits may include any or all of the following: assay reagents, buffers, a compounds of the present invention, an HIV polypeptide, an HIV nucleic acid, an anti-HIV polypeptide antibody, hybridization probes and/or primers, expression constructs for e.g., Tat, NF-κB, or NF-AT, etc. A therapeutic product may include sterile saline or another pharmaceutically acceptable emulsion and suspension base.
In a preferred embodiment of the present invention, a kit comprises one or more activators of latent HIV expression and one or more inhibitor of HDAC. Optionally, the kit includes one or more components used for HAART as described herein. Typically, these compounds are provided in a container.
This invention provides kits for eliminating a latent HIV reservoir in a mammalian cell. In a preferred embodiment of the present invention this kit comprises (i) a first container containing an activator of latent HIV expression, (ii) a second container containing an inhibitor of histone deacetylase, and (iii) an instruction for using the activator of latent HIV expression and the inhibitor of histone deacetylase for eliminating the latent HIV reservoir in the mammalian cell.
In another preferred embodiment of the present invention this kit comprises (i) a first container containing an inducer of NF-κB or NF-AT, (ii) a second container containing an inhibitor of histone deacetylase, and (iii) an instruction for using the inducer of NF-κB or NF-AT and the inhibitor of histone deacetylase for eliminating the latent HIV reservoir in the mammalian cell.
In addition, a kit may include instructional materials containing directions (i.e., protocols) for the practice of the methods of this invention. The instructions may be present in the subject kits in a variety of forms, one or more of which may be present in the kit. While the instructional materials typically comprise written or printed materials they are not limited to such. Any medium capable of storing such instructions and communicating them to an end user is contemplated by this invention. Such media include, but are not limited to electronic storage media (e.g., magnetic discs, tapes, cartridges, chips), optical media (e.g., CD ROM), and the like. Such media may include addresses to internet sites that provide such instructional materials.
In a preferred embodiment of the present invention, the kit comprises an instruction for using an activator of latent HIV expression and an inhibitor of HDAC for increasing the level of latent HIV expression above the level of latent HIV expression induced by the activator of latent HIV expression alone.
Optionally, the instruction comprises warnings of possible side effects and drug-drug or drug-food interactions.
A wide variety of kits and components can be prepared according to the present invention, depending upon the intended user of the kit and the particular needs of the user.
In a preferred embodiment of the present invention, the kit is a pharmaceutical kit and comprises a pharmaceutical composition comprising (i) an activator of latent HIV expression, (ii), an inhibitor of HDAC, and (iii) a pharmaceutical acceptable carrier. Optionally, the pharmaceutical kit comprises a Tat. In another preferred embodiment, the pharmaceutical kit comprises a component for use in HAART as described herein. Pharmaceutical kits optionally comprise an instruction stating that the pharmaceutical composition can or should be used for treating a condition or disease described herein.
Additional kit embodiments of the present invention include optional functional components that would allow one of ordinary skill in the art to perform any of the method variations described herein.
Although the forgoing invention has been described in some detail by way of illustration and example for clarity and understanding, it will be readily apparent to one ordinary skill in the art in light of the teachings of this invention that certain variations, changes, modifications and substitution of equivalents may be made thereto without necessarily departing from the spirit and scope of this invention. As a result, the embodiments described herein are subject to various modifications, changes and the like, with the scope of this invention being determined solely by reference to the claims appended hereto. Those of skill in the art will readily recognize a variety of non-critical parameters that could be changed, altered or modified to yield essentially similar results.
While each of the elements of the present invention is described herein as containing multiple embodiments, it should be understood that, unless indicated otherwise, each of the embodiments of a given element of the present invention is capable of being used with each of the embodiments of the other elements of the present invention and each such use is intended to form a distinct embodiment of the present invention.
The referenced patents, patent applications, and scientific literature, including accession numbers to GenBank database sequences, referred to herein are hereby incorporated by reference in their entirety as if each individual publication, patent or patent application were specifically and individually indicated to be incorporated by reference. Any conflict between any reference cited herein and the specific teachings of this specification shall be resolved in favor of the latter. Likewise, any conflict between an art-understood definition of a word or phrase and a definition of the word or phrase as specifically taught in this specification shall be resolved in favor of the latter.
As can be appreciated from the disclosure above, the present invention has a wide variety of applications. The invention is further illustrated by the following examples, which are only illustrative and are not intended to limit the definition and scope of the invention in any way.
EXAMPLES
Example 1
General Methods
The practice of the present invention will employ, unless otherwise indicated, conventional techniques of molecular biology, microbiology, recombinant DNA, and so forth which are within the skill of the art. Such techniques are explained fully in the literature. See e.g., Sambrook, Fritsch, and Maniatis, Molecular Cloning: A Laboratory Manual , Second Edition (1989), Oligonucleotide Synthesis (M. J. Gait Ed., 1984), Animal Cell Culture (R. I. Freshney, Ed., 1987), the series Methods In Enzymology (Academic Press, Inc.); Gene Transfer Vectors For Mammalian Cells (J. M. Miller and M. P. Calos eds. 1987), Current Protocols In Molecular Biology (F. M. Ausubel, R. Brent, R. E. Kingston, D. D. Moore, J. G. Siedman, J. A. Smith, and K. Struhl, eds., 1987).
A. Cell Culture
J-Lat 6.3, J-Lat 8.4 T-cells, and J-Lat 9.2 cells are Jurkat T cell lines containing integrated but transcriptionally latent HIV proviruses. These J-Lat cells contain wild-type Tat and TAR and appear to be highly representative of the latently infected cells present in vivo (Williams et al., 2004, J Biol Chem 279(40):42008-42017).
J-Lat 6.3 T cells, J-Lat 8.4 T-cells and J-Lat 9.2 T cells were obtained from Jordan et al., (Jordan et al., 2003, EMBO J 22(8):1868-1877). J-Lat cells were cultured in RPMI supplemented with 10% fetal calf serum (FCS) and penicillin/streptomycin and L-glutamine described (Williams et al., 2004, J Biol Chem 279(40):42008-42017; Williams et al., 2006, EMBO J 25:139-149).
Typically, cells were stimulated with prostratin (LC Laboratories), from about 0.1 to about 10 μM; with TNF-α (R&D Systems) at 10 ng/ml; with 4-α-phorbol 12-myristate 13-acetate (PMA); with trichostatin A (TSA) at concentration s ranging from about 50-400 nM, with valproic acid (Sigma) at concentrations ranging from 0.3-3 mM; or combinations of one or more of these compounds (see the following Examples for details).
B. Cell Viability Assay
Following stimulation, cells were cultured for 16 hours at 37° C. 90% humidity, 5% CO2. Cells were then analyzed by flow cytometry for viability.
Cells were scored as viable if they were detected in a characteristically “live” region of light scatter and defraction as measured by flow cytometry.
C. Cell Transfection Assays
Cell transfection assays were essentially performed as described (Williams et al., 2004, J Biol Chem 279(40):42008-42017; Williams et al., 2006, EMBO J 25:139-149).
10 6 J-Lat 6.3 cells cultured in RPMI+10% fetal calf serum (FCS) and penicillin/streptomycin were pelleted by centrifugation and resuspended in 0.4 mL RPMI without serum. Cell suspension was mixed with 1 μg of pMACS-kk H2kk expression vector DNA (Miltenyi), and 10 μg of pCMV4 (Andersson et al., 1989, J Biol Chem 264 (14):8222-8229), or 10 μg pCMV4-FLAG-Tat expression vector (gift of Eric Verdin), transferred to a 0.4 cm gap electroporation cuvette (Stratagene), and electroporated at 975 μF, 250 mV for ˜25×10 −3 seconds. Electroporated cells were resuspended in 4 mL medium, and returned to cell culture for 48 hours. 90 μl aliquots of each sample were distributed to U-bottomed 96-well plates and 10 μl of 200 ng/mL TNF-α (Biosource), 10 μl of 1 mM Trichostatin A (Biomol), or 10 μl of RPMI. For 30′-pulse TNF-α stimulation experiments, 10 μl of 200 ng/mL TNF-α was added to 90 μl cell suspension for 30 minutes, cells were transferred to a V-bottomed 96 well plate and centrifuged at 1800 RPMI for 3 minutes. Supernatant was removed and replaced, and procedure was repeated 2×. Cells were resuspended in 100 μl fresh RPMI with 10% serum and penicillin/streptomycin. 16 hours after treatment, cells were pelleted by centrifugation, and resuspended in 50 μl PBS+1:100 dilution of streptavidin-conjugated anti-H2kk antibody. Samples were incubated 10 minutes, diluted in 200 μl PBS, pelleted by centrifugation, and supernatant removed. Cells were resuspended in 50 μl PBS+1:100 dilution of biotin-allophycoerythrin (APC), incubated 10 minutes, diluted in 200 μl PBS, pelleted by centrifugation, supernatant removed, resuspended in 100 μl PBS, pelleted by centrifugation, supernatant removed and resuspended in 50 μl PBS. Samples were analyzed by flow cytometry using a Beckton Dickinson FACSCalibur. Cells were analyzed using FlowJo (TreeSoft) flow cytometry analysis software. Live cells were identified by characteristic light scatter and defraction and exclusively analyzed. Cells with APC fluorescence greater that untransfected cells stained with biotin-APC were considered to be H2kk-positive, and to have been successfully transfected. Subsequent analyses were restricted to this subset of cells
D. HIV Immunoassays (Western Blotting)
Immunoblotting analysis can essentially be performed as described (Williams et al., 2004, J Biol Chem 279(40):42008-42017).
J-Lat 6.3 or 9.2 cells were adjusted to 1×10 6 cells/ml and stimulated with TNF-α or prostratin for various times. Cells were then lysed on ice in egg lysis buffer (50 mM HEPES, pH 7, 250 mM NaCl, 1% Nonidet P-40, 5 mM EDTA) for 20 mM and clarified by microcentrifugation. Lysates were next added to an equal volume of 2× Laemmli buffer (25 mM Tris, 200 mM glycine, 0.1% SDS) and heated to 95° C. for 5 min. Proteins were separated by SDS-PAGE, transferred to polyvinylidene difluoride membranes, and immunoblotted with various antibodies.
E. HIV-LTR-Driven Expression of GFP
The J-Lat T-cell clones used herein are infected with full-length HIV proviruses and contain the Aequorea victoria green fluorescent protein (GFP) gene in lieu of Net thus permitting epifluorescence monitoring of viral transcriptional activity. Under basal conditions, little or no GFP expression is detected; however, transcriptional activation of the latent provirus leads to GFP expression, which can be detected at the single-cell level by flow cytometry. Flow cytometry analysis and FACS was essentially performed as described (Williams et al., 2004, J Biol Chem 279(40):42008-42017).
Cells were analyzed for GFP-fluorescence and general viability characteristics on a FACSCalibur flow cytometer (Becton Dickinson). Data were analyzed with FlowJo (Treesoft) flow cytometry analysis software.
F. Detection of HIV mRNA
1. RNA Analysis
RNA extraction and analysis of initiated and elongated HIV transcripts can be performed as described (Williams et al., 2006, EMBO J 25:139-149)
2. Semi-Quantitative PCR
PCR analysis can essentially be performed as described (Williams et al., 2004, J Biol Chem 279(40):42008-42017; Williams et al., 2006, EMBO J 25:139-149).
J-Lat 6.3 cells (1×10 6 cells/mi) were treated with TSA (100 nM) or TNF-α(20 ng/ml) for 2 h at 37° C. For analysis of HIV mRNA synthesis in nucleofected primary T cells, RNA was extracted from 0.5×10 6 cells with an RNA Wiz kit (Ambion). RNA transcripts were quantitated with the QuantiTect SYBR Green RT-PCR kit (Qiagen). To quantitate viral transcripts, serial dilutions of a quantitated RNA stock of full-length viral genome were used as a reference standard (gift of R Grant). Initiated transcripts were detected with primers HIVTAR5(5′-GTTAGACCAGATCTGAGCCT-3′) [SEQ ID NO: 1] and HIVTAR3 (5′-GTGGGTTCCCTAGTTAGCCA-3′) [SEQ ID NO: 2]. Elongated transcripts were detected with primers HIVTat5 (5′-ACTCGACAGAGGAGAGCAAG-3′) [SEQ ID NO: 3] and HIVtat 3 (5′-GAGTCTGACTGTTCTGATGA-3′) [SEQ ID NO: 4]. β-Actin mRNA copies were quantitated with primers β-actin5 (5′-GTCGACAACGGCTCCGGC-3′) [SEQ ID NO: 5] and β-actin3 (5′-GGTGTGGTGCCAGATTTTCT-3′) [SEQ ID NO: 6] specific for a 239 by region in the β-actin mRNA and samples were normalized for β-actin copies. Fluorescence profiles were collected on an ABI 7700 real-time thermal cycler and analyzed with SDS v1.91 (Applied Biosystems). The absence of nonspecific bands in RT-PCR products was confirmed on 2% agarose gels.
Example 2
TSA Synergizes with Prostratin to Activate Latent HIV Expression
J-Lat 6.3 and 8.4 T-cells cultured in RPMI supplemented with 10% fetal calf serum (FCS) and penicillin/streptomycin were counted and adjusted to 1×10 6 cells/ml. 80 μl aliquots of J-Lat 6.3 and 8.4 T-cells, respectively, were pipetted in a 96-well u-bottomed plate. 10 μl of 20 μM prostratin (final concentration 2 μM; LC Laboratories) were added to prostratin stimulated cell samples. 10 μl cell culture medium were added to unstimulated cells. 10 μl of 1 μM trichostatin A (final concentration of 100 nM; BIOMOL) were added to TSA-stimulated cell samples. 10 μl cell culture medium were added to unstimulated cells. One cell sample of J-Lat 6.3 and 8.4 T-cells was incubated with prostratin (2 μM) and TSA (100 nM). Samples were mixed by pipetting, returned to a 37° C. incubator with 5% CO 2 and 90% humidity for 16 hours. Then HIV-LTR-driven expression of GFP was assessed by flow cytometry using a Beckton Dickenson FACScalibur as described above. Data analysis was performed using Treesoft FlowJo software. Cells with greater GFP fluorescence than a non-GFP expressing Jurkat control cells were considered GFP-positive. These experiments showed that prostratin induced the activation of latent HIV expression. Although TSA had no significant effect when administered alone, it potentiated the effect of prostratin about 5-6 fold in J-Lat 6.3 cells ( FIG. 1A ) and about 6-7 fold in 8.4 T-cells ( FIG. 1B ). This experiment showed that TSA synergizes with prostratin to activate latent HIV expression.
In a similar experiment, J-Lat6.3kRed2 cells, a modified cell line derived from J-Lat6.3 containing an integrated kB-DsRed2 reporter, was used. J-Lat6.3kRed2 cells were counted and adjusted to 1×10 6 cells/ml. 80 μl aliquots were pipetted in a 96-well u-bottomed plate. Two-fold serial dilutions of 4, 2, and 1 μM trichostatin A (TSA) were made and added to the cells at final concentrations of 400 nM, 200 nM, and 100 nM, respectively. Three-fold serial dilutions of 100, 33, 11, 3.7 μM prostratin were made and added to cells at final concentrations of 10 μM, 3.3 μM, 1.1 μM, and 0.37 μM (0.4 μM in FIG. 1C ), respectively. Samples were mixed by pipetting, returned to a 37° C. incubator with 5% CO 2 and 90% humidity for 20 hours, HIV-LTR-driven expression of GFP was assessed by flow cytometry as described above. This experiment showed that TSA had a drastic effect on the activation of latent HIV expression. The synergistic effect observed with 370 (400) nM TSA, for example, was about 16 fold when used in combination with 0.4 μM prostratin. A representative result of this experiment is shown in FIG. 1C .
Example 3
Administration of TSA Reduces Prostratin-Induced Cell Death
As described herein, it is known in the art that high concentrations of prostratin exert some toxic effects on cells. Thus, using the same experimental set-up as described in Example 2, above, cell viability was determined. Cell viability were quantitated as described above. Using J-Lat 6.3 cells and 8.4 T-cells, it was observed that 2 μM prostratin induced cell death in about 50% of the cells. Upon co-administration of 100 nM TSA, the prostratin-induced cell death was almost completely inhibited. A representative result is shown in FIGS. 2A and 2B . A similar effect was observed in J-Lat6.3kRed2 cells (using the set-up as described in Example 2). TSA inhibited prostratin-induced cell death even when prostratin was used at a concentration of 10 μM ( FIG. 2C ). In this experiment, cells were incubated with prostratin for about 20 hours, whereas J-Lat 6.3 cells and 8.4 T-cells (in FIGS. 2A and 2B ) were incubated with prostratin for 36 hours. Thus, a higher cell death was observed with longer prostratin treatment.
Example 4
Valproic Acid Synergizes with Prostratin to Activate Latent HIV Expression
In order to test a possible synergistic effect of additional histone deacetylase inhibitors, the effect of valproic acid in combination with prostratin was analyzed. J-Lat6.3kRed2 cells were adjusted to 1×10 6 cells/ml. 80 μl cell aliquots were pipetted in a 96-well u-bottomed plate. Three-fold serial dilutions of 30, 10, and 3.3 mM valproic acid (VpA) were made by serial dilution in a 96-well v-bottomed plate and 10 μl of these dilutions, or medium alone was added to cells in final concentrations of 3 mM, 1 mM, 0.3 mM and 0 mM, respectively. Three-fold serial dilutions of 100, 33, 11, 3.7 μM prostratin were made in a 96-well v-bottomed plate and 10 μl of these dilutions, or medium alone was added to cells in final concentrations of 10 μM, 3.33 μM, 1.1 μM, 0.37 μM, and 0 μM, respectively. Samples were mixed by pipetting, returned to an incubator for 18 hours. HIV-LTR-driven expression of GFP was assessed by flow cytometry as described above. This experiment also showed that the histone deacetylase inhibitor, valproic acid, synergizes the effect prostratin has on the activation of latent HIV expression. For example, at a concentration of 0.3 mM, valproic acid potentiated the effect of prostratin (at 0.37 μM) about 6-7 fold. A representative result of this experiment is shown in FIG. 3 .
Example 5
Administration Valproic Acid Reduces Prostratin-Induced Cell Death
As described in Example 3 for TSA, the effect of valproic acid on blocking prostratin-induced cell death was analyzed using the same experimental set-up as described in Example 4. Although in this experiment the prostratin-induced cell death was less pronounced it was evident that at all tested concentrations, valproic acid blocked prostratin-induced cell death when prostratin was used at a concentration of 10 μM ( FIG. 4 )
Example 6
Tat Synergizes with TNF to Activate Expression of Latent HIV
To test whether the viral transcription activator protein, Tat, also has a synergistic effect on TNF mediated activation of latent HIV expression the following cell transfection experiment was performed. 10 6 J-Lat 6.3 cells cultured in RPMI+10% fetal calf serum (FCS) and penicillin/streptomycin were pelleted by centrifugation and resuspended in 0.4 mL RPMI without serum. This cell suspension was mixed with 1 μg of pMACS-kk H2kk expression vector DNA (Miltenyi Biotech; see also Williams et al., 2006, EMBO J 25:139-149) encoding mouse cell surface-expressed MHC class I (Petry et al., 1999, Int Immunol 11:753-763; Tetsu and McCormick, 1999, Nature 398:422-426; Porter et al., 2002, J Immunol 168:4936-4945; Finotto et al., 2001, J Exp Med 193: 1247-1260), and 10 μg of pCMV4 (Andersson et al., 1989, J Biol Chem 264 (14):8222-8229), or 10 μg pCMV4-FLAG-Tat expression vector (gift of Eric Verdin), transferred to a 0.4 cm gap electroporation cuvette (Stratagene), and electroporated at 975 μF, 250 mV for ˜25×10 −3 seconds. Electroporated cells were resuspended in 4 mL medium RPMI, supplemented with 10% fetal calf serum and penicillin/streptomycin and incubated for 48 hours at 37° C., 5% CO 2 , 90% humidity. 90 μl aliquots of each sample were distributed to U-bottomed 96-well plates and 10 μl of 200 ng/mL TNF-α (Biosource), 10 μl of 1 mM Trichostatin A (Biomol), or 10 μl of RPMI (i.e., unstimulated cells) were added. For 30′-pulse TNF-α stimulation experiments, 10 μl of 200 ng/mL TNF-α was added to 90 μl cell suspension for 30 minutes.
After these treatments, the cells were transferred to a V-bottomed 96 well plate and centrifuged at 1,800 rpm for 3 minutes. The supernatant was removed and replaced, and procedure was repeated 2×. Cells were resuspended in 100 μl fresh RPMI with 10% serum and penicillin/streptomycin. 16 hours after treatment, cells were pelleted by centrifugation, and resuspended in 50 μl PBS+1:100 dilution of streptavidin-conjugated anti-H2kk antibody (BD Pharmingen). Samples were incubated 10 minutes, diluted in 200 μl PBS, pelleted by centrifugation, and supernatant removed. Cells were resuspended in 50 μl PBS+1:100 dilution of biotin-allophycoerythrin (APC), incubated 10 minutes, diluted in 200 μl PBS, pelleted by centrifugation, supernatant removed, resuspended in 100 μl PBS, pelleted by centrifugation, supernatant removed and resuspended in 50 μl PBS.
Cell samples were analyzed by flow cytometry using a Beckton Dickinson FACSCalibur. Cells were analyzed using FlowJo (TreeSoft) flow cytometry analysis software. Live cells were identified by characteristic light scatter and defraction and exclusively analyzed. Cells with APC fluorescence greater that untransfected cells stained with biotin-APC were considered to be Hak-positive, and to have been successfully transfected. Subsequent analyses were restricted to this subset of cells. Cells with greater GFP fluorescence than a non-GFP expressing Jurkat cell line were scored as GFP-positive. Percent GFP-positive cells was quantified and plotted. A representative result is shown in FIG. 5 .
This experiment demonstrates synergistic activation of latent HIV expression with coadministration of Tat and TNF or TSA. Whereas Tat alone induced only a moderate level of latent HIV-driven expression of GFP, coadministration of either TNF or TSA strongly enhanced this activity ( FIG. 5 ). Transient induction of NF-κB with 30-minute pulse treatment of TNF-α drove weak expression of latent HIV. However, expression of latent HIV in Tat-expressing cells was strongly sensitized to TNF-α pulse ( FIG. 5 ). These data demonstrate the effectiveness of Tat as a synergistic agent with weak activators of HIV expression.
Example 7
TNF and TSA Synergizes with Tat to Activate Expression of Latent HIV in J-Lat 9.2 Cells
The experiment described in Example 6 using J-Lat 6.3 cells was repeated using J-Lat 9.2 cells. A similar result was obtained ( FIG. 6 ). | The present invention provides methods and compositions useful for the elimination of latent HIV reservoirs that persist despite HAART. The methods and compositions overcome this latent barrier by inducing the replication of HIV in latently infected T cells while preventing the spread of the newly produced virions to uninfected cells by providing HAART simultaneously. Compositions of the invention comprise an activator of latent HIV expression, such as prostratin, and an inhibitor of histone deacetylase, such as TSA. A surprising finding of this invention is that the inhibitor of the histone deacetylase synergizes the effect of prostratin thus, allowing administering to a patient a lower, non-toxic dose of prostratin. | 0 |
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application claims the benefit of U.S. Provisional Patent Application Ser. No. 61/769,386 filed Feb. 26, 2013, the entire contents of which are incorporated herein by reference thereto.
[0002] This application also claims the benefit of U.S. Provisional Patent Application Ser. No. 61/769,388 filed Feb. 26, 2013, the entire contents of which are incorporated herein by reference thereto.
[0003] Reference is also made to the following U.S. patent application Ser. No. 13/862,074 filed Apr. 12, 2013, which claims priority to the following U.S. Provisional Patent Application Ser. No. 61/625,179 filed Apr. 17, 2012, the entire contents of each of the aforementioned applications are incorporated herein by reference thereto.
TECHNICAL FIELD
[0004] Exemplary embodiments of the present invention relate to an actuator for a shift by wire system and, more particularly, to a manual override system for an electronically controlled linkage.
BACKGROUND
[0005] Vehicles provide a number of controls allowing the driver of the vehicle to control various functions of the vehicle during operation. One control that is typically provided is a means for shifting the vehicle transmission. Automatic transmissions include a limited number of control selections such as park, reverse, neutral and drive as well as variants thereof.
[0006] In some automatic transmissions, a shift lever or mechanism is generally provided, wherein the driver operates the vehicle by moving the shift lever in a pattern in order to shift gears of the transmission. In some contemplated applications, the shifting of the transmission is achieved through an electronic system or shift by wire system wherein signals are provided to an electric motor coupled to the transmission via a button or actuator located within the vehicle compartment.
[0007] In an electronic system, an operator may not be able to shift the transmission if the vehicle loses power or there is a failure of one of the sensors and/or the motor of the electrical system.
[0008] Accordingly, it is desirable to provide an actuator for an electronic shift system wherein manual operation thereof is provided.
SUMMARY OF THE INVENTION
[0009] According to one exemplary embodiment of the present invention, an actuator for a shift by wire system is provided. The actuator having: a motor; a rack; a gear train configured to cause linear movement of the rack in response to rotational movement of the motor; a clutch mechanism for coupling and decoupling the rack to the motor; and a manual override for operating the clutch mechanism.
[0010] In another exemplary embodiment, a shift by wire system for a vehicle transmission is provided. The system having: an input device; a motor; a microcontroller operatively coupled to the motor and configured to receive signals from the input device to operate the motor; a sensor operatively coupled to the microcontroller and configured to receive signals from sensor, wherein the signals from the sensor are indicative of a position of the motor; a rack; a gear train configured to cause linear movement of the rack in response to rotational movement of the motor; a clutch mechanism for coupling and decoupling the rack to the motor; and a manual override for operating the clutch mechanism.
[0011] In yet another exemplary embodiment, a method for manually overriding a shift by wire system is provided. The method including the steps of: decoupling a rack of the shift by wire system from a motor by rotating a cam gear from a first position in a first direction to an intermediate position wherein a clutch spool is moved from a first position, wherein the clutch spool couples the motor to the rack to a second position, wherein the clutch spool decouples the rack from the motor; and further rotating the cam gear in the first direction from the intermediate position to a second position wherein a lever moves the rack after it has been decoupled from the motor, wherein the cam gear is spring biased into the first position and the clutch spool is spring biased into the first position.
[0012] In yet another embodiment, a clutch mechanism for coupling and decoupling a motor to a rack is provided. The clutch mechanism having: a clutch lever pivotally mounted to an axis for movement from a first position to a second position; a cam gear having a cam surface, wherein rotational movement of the cam gear causes the cam surface to move the clutch lever from the first position to the second position; and a gear train configured to cause linear movement of the rack in response to rotational movement of the motor, wherein movement of the clutch lever from the first position to the second position disconnects a pair of gears of the gear train.
[0013] In yet another embodiment, a method of decoupling and coupling a motor to a rack is provided. The method including the steps of: decoupling the rack from the motor by rotating a cam gear from a first position in a first direction to an intermediate position wherein a clutch spool is moved from a first position, wherein the clutch spool couples the motor to the rack to a second position, wherein the clutch spool decouples the rack from the motor; and further rotating the cam gear in the first direction from the intermediate position to a second position wherein a lever moves the rack after it has been decoupled from the motor, wherein the cam gear is spring biased into the first position and the clutch spool is spring biased into the first position and wherein the second direction is perpendicular to the first direction.
[0014] The above-described and other features and advantages of the present invention will be appreciated and understood by those skilled in the art from the following detailed description, drawings, and appended claims.
BRIEF DESCRIPTION OF THE DRAWINGS
[0015] Embodiments of the present invention will now be described, by way of example only, with reference to the accompanying drawings in which:
[0016] FIG. 1 is a view of an actuator in accordance with one non-limiting exemplary embodiment of the present invention;
[0017] FIG. 2 is a perspective view of the actuator illustrated in FIG. 1 ;
[0018] FIG. 3 is a perspective view of the actuator illustrated in FIG. 1 with portions of a clutch mechanism removed for illustration purposes;
[0019] FIGS. 4 and 5 are other perspective views of the actuator;
[0020] FIGS. 6-9 are views illustrating movement of the clutch mechanism in accordance with one exemplary embodiment; and
[0021] FIGS. 10 and 11 are cross-sectional views of components of the clutch mechanism illustrating movement of the clutch mechanism.
DETAILED DESCRIPTION
[0022] Referring now to the FIGS., an actuator 10 for use in a shift by wire system is illustrated. In one non-limiting exemplary embodiment, the actuator is configured to be mounted under a console in the passenger compartment of the vehicle or directly on a transmission of the vehicle or in any other suitable location. For use in vehicular applications, the actuator 10 needs to move a vehicle transmission 12 (illustrated schematically) into a specific gear. In one exemplary embodiment, the actuator is directly coupled to the transmission or is coupled thereto by a cable attachment 14 . As mentioned above, there is a need to provide a manual override in order to move the transmission from one position to another in the event of a power failure or a failure of a component of the shift by wire system. For example, there may be a need to move the transmission out of a park position into a neutral or other position in order to allow for towing of the vehicle.
[0023] In the illustrated embodiment, a rack 16 is coupled to the transmission either directly or by the cable 14 and is driven by a gear train 18 powered by a single motor 20 . Input signals from a driver select device 22 are processed by a controller or microcontroller 24 operatively coupled to the motor 20 using feedback signals from the actuator to identify its position. In one embodiment, the driver select device 22 (illustrated schematically) may be any one of a push button, lever, sensor, switch or any other equivalent device capable of providing signals to the microcontroller in order to operate motor 20 and thus operate the transmission in a shift by wire process, wherein there is not actual physical link directly between device 22 and transmission 12 .
[0024] In one embodiment, an encoder 26 and sensor 28 are also operatively coupled to the controller or microcontroller 24 so that feedback signals are provided to the microcontroller. In one non-limiting exemplary embodiment, controller or microcontroller 24 comprises a microprocessor, microcontroller or other equivalent processing device capable of executing commands of computer readable data or program for executing a control algorithm that controls the operation of the actuator and/or shift by wire system. In order to perform the prescribed functions and desired processing, as well as the computations therefore (e.g., the execution of fourier analysis algorithm(s), the control processes prescribed herein, and the like), the controller may include, but not be limited to, a processor(s), computer(s), memory, storage, register(s), timing, interrupt(s), communication interfaces, and input/output signal interfaces, as well as combinations comprising at least one of the foregoing. For example, the controller may include input signal filtering to enable accurate sampling and conversion or acquisitions of such signals from communications interfaces.
[0025] In accordance with an exemplary embodiment of the present invention, a manual override is provided through the use of a clutch mechanism 30 configured to disengage the drivetrain of the vehicle from the rack 16 of the actuator 10 . As used herein, clutch mechanism 30 may refer to the components necessary to input a manually applied user action to decouple the rack from the motor and/or subsequently move the same or alternatively anyone of the components that performs the aforementioned actions or sub actions necessary to perform the aforementioned actions.
[0026] In one embodiment, the clutch mechanism 30 or a component thereof further comprises a lever 32 configured to move the rack independently by a pre-described amount.
[0027] During normal electrical operation (e.g. shift by wire) inputs via device 22 are provided to the microcontroller 24 which in turn operates motor 20 . As motor 20 is operated a worm 34 coupled to a shaft 36 of the motor 20 is rotated. Rotation of worm 34 causes rotation of worm gear 38 . Worm gear 38 is also coupled to a gear 40 which rotates with worm gear 38 about an axis 42 . Gear 40 is configured to mesh with a gear 44 coupled to a gear 46 that is configured to mesh with rack 16 . Accordingly rotation of worm gear 38 in the directions of arrows 48 causes linear movement of rack 16 in the direction of arrows 50 which in turn causes a corresponding movement of the gears of the transmission coupled thereto either directly or indirectly.
[0028] As mentioned above, encoder 26 is also coupled to shaft 36 so that the rotational movement and location of worm 34 as well as rack 16 can be fed back to microcontroller 24 .
[0029] As previously discussed, power loss to the vehicle or system or malfunction of one of the components of the shift by wire system may prevent operation of the vehicle transmission and more particularly, prevent the same from being shifted from one position to another position more suitable for operation during the above malfunction (e.g., vehicle towing, etc.).
[0030] In accordance with one exemplary embodiment of the present invention, clutch mechanism 30 is provided to achieve manual operation of the actuator in the event of such a failure mentioned above. Clutch mechanism 30 comprises a clutch lever 52 configured to move a clutch spool or clutch component 54 from a first position wherein gear 46 is coupled to gear 42 by for example, a plurality of pins 56 of the clutch spool which when are in the first position couple gear 46 to gear 42 by for example engaging portions or openings of gear 42 and gear 46 and thus the rack 16 is directly coupled to motor 20 to a second position wherein pins 56 no longer couple gear 46 to gear 42 (e.g., pins 56 are moved out of engagement with both gears 42 and 46 or pins only engage one of gears 42 and 46 ) thus rack 16 is no longer coupled to motor 20 .
[0031] The first position of the clutch lever 52 is illustrated in at least FIGS. 8 and 10 and FIG. 10 illustrates cross-sectional views of portions of the clutch mechanism 30 as well as gears 46 and 42 . As illustrated in at least FIGS. 4 and 10 the clutch lever 52 and clutch spool 54 are spring biased into the first position by a spring 58 .
[0032] The second position of the clutch lever 52 is illustrated in at least FIGS. 4 , 7 , 9 and 11 . The clutch mechanism 30 further comprises a cam gear 70 having a cam surface 72 configured to act upon a portion or one end 74 of clutch lever 52 such that rotation of cam gear 70 in the directions of arrows 48 causes portion 74 of clutch lever 52 two move along cam surface 72 and thus transition the clutch lever 52 from the first position to the second position and thus overcome the biasing force of spring 58 such that clutch spool or clutch component 54 can be moved into a position wherein gears 42 and 46 are decoupled from each other and thus rack 16 is uncoupled from motor 20 .
[0033] Cam gear 70 further comprises a plurality of teeth 76 configured to engage a gear 78 whose rotation facilitates movement of the cam gear 70 such that clutch lever 52 is moved from the first position to the second position. Alternatively, clutch lever 52 and/or cam gear 70 is coupled to a cable or other actuation device that can be manipulated by an operator in order to transition clutch lever 52 from the first position to the second position and provide the desired movements of the clutch mechanism as well as the rack.
[0034] In addition and in one non-limiting exemplary embodiment, the clutch mechanism 30 provides two features. The first one being movement of the clutch spool or clutch component 54 from the first position to the second position in order to disengage the motor 20 from the rack 16 and ultimately the drivetrain of the vehicle while the second one is to move the rack 16 linearly after it has been disengaged from the motor 24 gear train 18 . The linear movement of rack 16 by cam gear 70 is facilitated by lever 32 which is coupled to cam gear 70 .
[0035] Accordingly and as illustrated in the attached figures rotational movement of cam gear 70 in a direction from a first position via a gear 78 will cause portion 74 to slide along cam surface 72 and clutch lever 52 is pivoted about an axis 80 as it moves from the first position to the second position in order to move the clutch spool 54 from the first position to the second position so that gears 42 and 46 are decoupled from each other. At this point or at an intermediate position of cam gear 70 , lever 32 is now in contact with a surface 82 of rack 16 and further movement of cam gear 70 in the direction (e.g., from the intermediate position of the cam gear 70 to a second position of the cam gear 70 ) will cause linear movement of the rack in the direction of arrow 86 which will in turn move the transmission from one gear selection to another.
[0036] In one non-limiting embodiment, gear 78 is configured to be moved via a hand tool (e.g., screwdriver from an individual) with a minimal amount of rotating motion merely necessary to disengage motor 20 from rack 16 and then move rack 16 in order to change the vehicle transmission from one selected position to another selected position (e.g., from the first position to the intermediate position to the second position). In the illustrated embodiment, movement of the rack is in a direction 90° offset or perpendicular from movement of the clutch spool 54 or clutch lever 52 . Of course, other directions are contemplated to be within the scope of various embodiments of the present invention. Accordingly, the clutch and manual override system provides unique two-stage motion acting on sequential components and perpendicular axes. Of course, numerous other configurations (e.g., other than 90° offset) are contemplated to be within the scope of exemplary embodiments of the present invention.
[0037] In one embodiment, gear 78 or a portion thereof is accessible via an access panel in order to provide the rotational movement of gear 78 via a hand tool. See for example slot 79 which may be configured to receive a corresponding screw driver. Of course, numerous other types of configurations are contemplated. Alternatively, gear 78 is operatively coupled to a manual input device in order to provide the desired movement of gear 78 (e.g., cable, lever, etc.) Referring now to at least FIG. 4 , cam gear 70 is spring biased into a first position by a spring 88 wherein gear 78 is configured to engage a first end of teeth 76 of cam gear 70 and cam surface 72 has not caused rotational movement of clutch lever 52 . Accordingly and as cam gear 70 is rotated via a rotational movement of gear 78 spring 88 will provide a biasing force to return cam gear 70 to the first position such that the clutch mechanism 30 we engages or re-couples motor 22 rack 16 . In other words once gear 78 is rotated in order to decouple the motor 20 from the rack 16 and rack 16 is moved via lever 32 , spring 88 will cause cam gear 72 rotate back to the first position such that clutch mechanism 30 can be couple motor 22 rack 16 via gear train 18 although rack 16 has now been repositioned via lever 32 . In addition and in order to assist in this process spring 58 will also bias the clutch spool 56 back into the first position.
[0038] In one non-limiting exemplary embodiment, a two-piece cam gear/lever driven by a separate driver is provided. The cam gear, when rotated, acts upon a clutch lever that is used to push the clutch spool with an initial part of its full rotation. The cam moves the lever through its travel to push the clutch spool to disengage the motor from the drivetrain. Continued rotation of the cam gear after this disengagement impacts an additional lever that pushes the rack a prescribed amount. At the end of this rotation the cam gear is acted upon by a return spring which will rotate the cam gear back to its initial position thereby rotating the lever away from the rack. Final rotation of the cam gear by the return spring will lower the clutch lever allowing a spring acting axially on the clutch spool to return the clutch spool to its original position engaging the motor to the drivetrain. The cam gear/lever can be acted upon by a separate driver either in direct connection by gear teeth or remotely by a cable.
[0039] In one non-limiting exemplary embodiment, the actuator 10 (gear train 18 and clutch mechanism 30 ) are configured such that rotational movement of cam gear 70 will only contact portion 74 of clutch lever 52 when the vehicle transmission is in a predetermined state (e.g., Park) and the two-step rotational movement of the clutch mechanism 30 will first disengage the gear train 18 from the rack and then move the rack via lever 32 to a another predetermined state (e.g., Park to neutral) in order to allow for towing of the vehicle. Of course, numerous other configurations are contemplated to be within the scope of exemplary embodiments of the present invention and the aforementioned movements are merely examples and the various embodiments of the present invention are not intended to be specifically limited to the examples provided herein.
[0040] It is, of course, that various configurations and alternatives are considered to be within exemplary embodiments of the present invention and it may or may not be necessary to spring bias cam gear 70 and clutch spool 54 back into their first positions.
[0041] While the invention has been described with reference to an exemplary embodiment, it will be understood by those skilled in the art that various changes may be made and equivalents may be substituted for elements thereof without departing from the scope of the invention. In addition, many modifications may be made to adapt a particular situation or material to the teachings of the invention without departing from the essential scope thereof. Therefore, it is intended that the invention not be limited to the particular embodiment disclosed as the best mode contemplated for carrying out this invention, but that the invention will include all embodiments falling within the scope of the appended claims. | A clutch mechanism for coupling and decoupling a motor to a rack is disclosed herein. The clutch mechanism having: a clutch lever pivotally mounted to an axis for movement from a first position to a second position; a cam gear having a cam surface, wherein rotational movement of the cam gear causes the cam surface to move the clutch lever from the first position to the second position; and a gear train configured to cause linear movement of the rack in response to rotational movement of the motor, wherein movement of the clutch lever from the first position to the second position disconnects a pair of gears of the gear train. | 5 |
BACKGROUND OF THE INVENTION
This invention relates to a device, a program automaton for weaving machines, finding application in the textile industry, especially in weaving and knitting.
A program automaton for weaving machines is known (which is described in Bulgarian Authorship Certificate No. 14496 and corresponding U.S. Pat. No. 3,674,991) with program nodes where a block for programming the weft comprises three or more series-connected electronic counters with decimal decoders, one electronic counter with decoder or two decade counters with decoders, playing the role of electronic switches, and a number of four-input AND-gates which number depends upon the number of the outputs of the decoder of the electronic switch. It is known as well that with ten-positional keys, connected with the outputs of the decoders and the inputs of the AND-gates, the program can be set. It is well known that all electronic counters applied in the program automaton are bidirectional in order to return back or reverse the program, which is necessary in view of the technological requirements of weaving, i.e. the necessity of deweaving several wefts, in the event that the stopping mechanism is not in action, to avoid faults in weaving.
Modern electronic counter circuits are bidirectional with two inputs--one for adding and another for subtracting. Therefore, they can add from 0 to 9, if decimal, and from 0 to 15, if hexadecimal. Conversely, they can subtract from 9 to 0, or from 15 to 0, repeating the cycle for addition and for subtraction. The counters operate similarly also when they are series-connected, i.e. for counting units, tens, hundreds, etc. The known program automaton for weaving machines is realized in a way that, with a minimum number of counters and minimum time for programming, it is possible for a large range of repeats to be set, e.g. to set a program of 1600 wefts with three counters for only two minutes, with 16 color tapes or bands in the repeat. Only two counters--for units and tens--are used for that purpose, along with one counter-switch, as at every one of the 16 colors after counting out one of them, the two counters are nulled and rebegin the counting. At a given decision of the program automaton, the weaving (adding) does not create problems. The deweaving (subtraction), when a deweaving is only of wefts from the color to which position the counter-switch is set, also does not create problems. However, a disadvantage of the known automaton is that when the deweaving has to continue to another color of the repeat, there are some difficulties at the returning of the counter-switch and at the series-connected counters, especially for the subtraction of digits, e.g. 100-16, 100-24, 100-36, 100-17, etc., because the counters for subtraction only count from 99 to 0, etc.
SUMMARY OF THE INVENTION
The task of the invention is to create a program automaton for weaving machines into which block for weft programming is incorporated a block for deweaving of complex programs, with a possibility for continuation of the deweaving of another color of the repeat.
This task is solved by a program automaton for weaving machines, comprising a transducer, connected to the crankshaft of the weaving machine and to a block for weft programming. The block for weft programming is connected to a block for subroutines and to control electromagnets for color selection. The block for subroutines is connected in a feedback path with the block for weft programming. The transducer is also connected to a block for weave programming, which, in turn, is connected to an electronic keys block. This electronic keys block is connected to a control block for controlling two blocks of electromagnets, the control block being further connected to the transducer. In the blocks for weft programming and for subroutines, there is included a block for deweaving at complex programs, comprising a reverse key, a first AND-gate, the output of which is connected to one of the inputs of a two-input static flip-flop, the other input being connected to the output of a bank of second AND-gates of the program automaton for weaving machines. The output of the first AND-gate is also connected to the input for subtraction of the counter-switch. A rectangular pulse generator is connected to one input of a two-input AND-gate while the second input of the AND-gate is connected with one of the outputs of the static flip-flop, and the output of the AND-gate is connected, by means of an OR-gate, to the input for subtraction of a units counter, to which is also connected the transducer for supplying pulses from the crankshaft of the weaving machine.
DESCRIPTION OF THE DRAWINGS
Figures illustrating the invention are shown in the enclosed drawings, where:
FIG. 1 illustrates a block scheme of the program automaton for weaving machines;
FIG. 2 illustrates the built-in block for deweaving of complex programs.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring to FIG. 1, the program automaton for weaving machines comprises a transducer 1 which is coupled to the crankshaft of a weaving machine and generates an output pulse for each revolution of the crankshaft in the forward direction, each revolution indicating the weaving of one weft. The transducer 1 is connected to a block for weft programming 18 which, in turn, is connected to a block for subroutines 19 and to electromagnets of color selection elements 20 which alternatively select the various color bands. The block for subroutines 19 is connected in a feedback loop with the block for weft programming 18. The transducer 1 is further connected to a block for weave programming 21 which, in turn, is connected to an electronic keys block 22. The keys block 22 is connected to a control block 23 which controls two blocks of electromagnets 24 and 25 which, in turn, control the formation of each weft. The transducer 1 is also connected to the control block 23.
The block for deweaving of complex programs is incorporated in the blocks 18 and 19 and, referring to FIG. 2, comprises a reverse key 2 having one end connected to ground and the other end connected to an inverter 3. The output of the inverter 3 is connected to one input of a three-input AND-gate 4, the output thereof being connected to one input of a static flip-flop 5. A first output of the flip-flop 5 is connected to an AND-gate 8 while a pulse generator 6, having an output frequency of, for example, 1000 Hz. to 5000 Hz., is also connected to AND-gate 8. A second output of flip-flop 5 is connected to an AND-gate 7 to which the output of a transducer 9 is also applied. The transducer 9, like transducer 1, is connected to the crankshaft of the weaving machine and produces an output pulse for each revolution of the crankshaft in the reverse direction.
The block for deweaving further comprises three counters 12, 14 and 16 with associated decoders 13, 15 and 17, respectively. Counter-decoder 12/13 provides individual outputs corresponding to the desired number of color bands, e.g. 16, and also represents the output of 18 which controls color selection elements 20 in FIG. 1. Counter 14 is coupled to counter 16 such that the counter-decoders 14/15 and 16/17 provide individual outputs representing the number of wefts, ten and units, respectively. Transducer 1 is coupled to the counting input of counter 16 while the null outputs of decoders 15 and 17 are connected respectively to the other two inputs of AND-gate 4. Each of the outputs of counter-decoder 12/13 is connected an input each of a bank of respective three-input AND-gates 11, the other respective inputs being selectively connected to the outputs of counter-decoders 14/15 and 16/17 whereby the desired number of wefts for each color band may be programmed. The outputs of the AND-gates 11 are combined and applied to a second input of flip-flop 5, the resetting inputs of counters 14 and 16 and to the incrementing input of counter 12. For subtractions, the output of AND-gate 4 is applied to the decrementing input of counter 12, while the outputs from AND-gates 7 and 8 are applied, through an OR-gate 10, to the subtracting input of counter 16.
The operation of the block for deweaving of complex programs will now be described. At the necessity of deweaving, the reverse key 2 is switched and a logic "one" appears at the output of inverter 3. Assuming that one or both of the counter-decoders 14/15 and 16/17 are not at their respective null positions, the second output of flip-flop 5 is at logic "one" which then activates AND-gate 7 allowing pulses from transducer 9 to pass through OR-gate 10 decrementing counter 16 and, in turn, counter 14. When both counters 16 and 14 reach zero, the null outputs from decoders 17 and 15, along with the logic "one" from inverter 3, cause AND-gate 4 to produce a logic "one" output. This logic "one" output then decrements counter 12 one position while changing the state of flip-flop 5 which then turns off AND-gate 7 and applies a logic "one" to AND-gate 8 which allows the pulses from generator 6 to rapidly decrement the counters 16 and 14. At the point where the outputs of the decoders 17 and 15 correspond to the AND-gate of the bank of AND-gates 11 selected by the output of the decoder 13, the output therefrom switches to a logic "one", again changing the state of flip-flop 5 which thereupon turns off AND-gate 8 and turns on AND-gate 7 allowing the block to continue the deweaving process for the particular color band. The above procedure repeats for the rest of the sequence of color bands until deweaving is terminated. | There is provided a program automaton for a weaving machine that includes means for effecting deweaving when there is more than one color in the repeat. The invention includes programmable counter means and a counter-switch. On deweaving, the counter means is decremented until it reaches zero. The counter-switch is then decremented one position while the counter means is reset and rapidly decremented to the programmed limit for the preceeding color in the repeat. | 3 |
TECHNICAL FIELD
[0001] The present application relates generally to enhancement of system performance in a wireless network and, more specifically, to reduction of inter-cell interference in a wireless network to optimize system capacity.
BACKGROUND
[0002] Power control is used on the uplink link in a wireless communication system to control the power of signals received at each base station from the wireless devices. As a wireless device moves within the network, the channel conditions change continuously due to fast and slow fading, shadowing, number of users, external interference, and other factors. Closed loop power control algorithms dynamically control the transmit power of the wireless device on the uplink link. Closed loop power control includes inner loop and outer loop power control mechanism. For inner loop power control, the base station measures the SIR of the received signal, compares the measured SIR to a SIR target, and adjusts the transmit power of the wireless device depending on the comparison. Outer loop power control adjusts the SIR target for the inner loop power control mechanism to maintain desired performance criteria, such as a desired Frame Error Rate (FER).
[0003] The inner loop power control mechanism provides improved performance for fast fading channels. Typically, in inner loop power control, the base station can send as many as 1500 up/down power control commands per second to the wireless device. The use of up/down power control commands keeps the received power level constant at the base station. When the received power level at the base station remains stable, the number of re-transmissions by the wireless device due to transmission errors can be maintained, e.g., below a threshold. Power control can also reduce intra-cell interference between uplink transmissions.
[0004] One problem with power control is that when fast fading occurs, the power of the wireless device may be increased many decibels (dBs) to compensate the path loss due to fast fading. The increase may be as large as 30 dBs. Because the fast fading loss to different cells has low correlation, a large increase of transmit power by the wireless device to maintain the signal level at the serving base station may result in significant interference with neighboring cells.
[0005] Therefore, the conventional method of increasing a wireless device's uplink transmit power to compensate for fast fading leads to strong inter-cell interference. The affected neighboring cells may need to combat the interference with additional resources. Improved methods and apparatus are needed for efficient utilization of resources and improved system capacity.
SUMMARY
[0006] The present application discloses methods and apparatus for improving a normal link adaptation process. The normal link adaptation process may be used to compensate for fast fading dips.
[0007] In some embodiments, a method for modifying a link adaptation process is disclosed. The method is implemented at a wireless device and modifies a link adaptation process that is used for uplink transmissions from the wireless device. During a normal link adaption process, the wireless device receives one or more transmission parameters from a base station. Based on the one or more received transmission parameters, the wireless device determines a slot transmit power that is used for transmitting a radio signal on a radio channel. The wireless device also calculates an average transmit power and compares the average transmit power to the slot transmit power. Based on the comparison, the wireless device derives a transmission parameter. The wireless device then transmits a data packet in accordance with the derived transmission parameter.
[0008] In some embodiments, a wireless device configured to modify a link adaptation process is disclosed. The wireless device comprises a transceiver and a processing circuit. The transceiver is configured to receive and transmit signals. The processing circuit is configured to modify the link adaption process. The processing circuit is configured to determine a slot transmit power for transmitting a radio signal on a radio channel and calculate an average transmit power. The processing circuit is further configured to derive a transmission parameter based on a comparison of the slot transmit power and the average transmit power.
[0009] In some embodiments, a method is implemented at a base station for controlling a modified link adaptation process of a wireless device. The base station determines one or more controlling parameters for controlling the modified link adaptation process at the wireless device. The one or more controlling parameters are then transmitted to the wireless device for use in modifying the link adaptation process.
[0010] In some embodiments, a base station configured to control a modified link adaptation process of a wireless device is disclosed. The base station comprises a transceiver for transmitting data and control signals to the wireless device. The base station also comprises a processing circuit for determining one or more controlling parameters. The controlling parameters are transmitted to the wireless device and used by the wireless device to modify a link adaptation process.
BRIEF DESCRIPTION OF THE DRAWINGS
[0011] FIG. 1 illustrates an exemplary wireless communication network implementing inner loop power control.
[0012] FIG. 2 illustrates a link adaptation process in which a fast fading dip detected by a base station and a fast fading compensation implemented by a wireless device.
[0013] FIG. 3 illustrates an exemplary method of modifying a link adaptation process at a wireless device.
[0014] FIG. 4 illustrates an exemplary wireless device configured to modify a link adaptation process.
[0015] FIG. 5 illustrates an exemplary method implemented at a base station for controlling a modified link adaptation process of a wireless device.
[0016] FIG. 6 illustrates an exemplary base station configured to control a modified link adaptation process of a wireless device.
DETAILED DESCRIPTION
[0017] Referring now to the drawings, the present invention will be described in the context of a wireless communication network 10 implementing High Speed Packet Access (HSPA) services. The wireless communication network may, for example, operate according to the Wideband Code Division Multiple Access (VVCDMA) standard, Long Term Evolution (LTE) standard, or other standard providing HSPA services. The wireless communication network 10 comprises a plurality of base stations 100 providing service in respective cells 12 of the wireless communication network. The base stations 100 are sometimes referred to as NodeBs (NBs), Evolved NodeBs (eNBs), or access nodes.
[0018] FIG. 1 illustrates two cells 12 , denoted as Cell A and Cell B, served by respective base stations 100 . A wireless device 200 is connected to the base station 100 in Cell A. The base station 100 in Cell A receives uplink transmissions from the wireless device 200 on an uplink channel, for example, a Dedicated Packet Control Channel (DPCCH) in WCDMA systems, and implements closed loop power control to maintain the signal level at the base station at a desired level. The signal level of the received signal may be measured as Signal to Interference Ratio (SIR) or Received Signal Code Power (RSCP). In one embodiment, the base station 100 measures the SIR of the received signal, compares the measured SIR to a SIR target, and adjusts the transmit power of the wireless device 200 depending on the comparison. When the SIR is above the SIR target, the base station 100 sends a down command and the wireless device 200 decreases its transmit power by one step. When the SIR is below the SIR target, the base station 100 sends an up command and the wireless device 200 , which increases its transmit power by one step. The base station 100 also implements outer loop power control to adjust the SIR target for the inner loop power control mechanism to maintain a desired performance criterion, such as a desired Frame Error Rate (FER).
[0019] When the wireless device 200 experiences fast fading, the received signal power will deteriorate rapidly, and the base station 100 will increase the transmit power of the wireless device 200 to maintain the desired signal level at the base station 100 . Fast fading refers to the phenomenon in which the time scale of the variation of the radio condition is small compared to the time scale of the application utilizing the channel.
[0020] FIG. 2 illustrates how inner loop power control compensates for path loss due to fast fading. FIG. 2( a ) illustrates the received signal strength at the base station 100 . FIG. 2( b ) illustrates the transmit power of the wireless device 200 . In FIG. 2( a ), a fast fading dip takes place at time t 0 . In some embodiments, the dip in the received signal power may be detected using SIR measurements or RSCP measurements. As the received signal power drops, the measured SIR also drops and the base station 100 sends power up commands to the wireless device 200 to compensate for the path loss due to fast fading. Upon receipt of the power up commands received from the base station 100 , the wireless device 200 increases its transmit power to counteract the fast fading. FIG. 2( b ) illustrates how the transmit power of the wireless device 200 changes with time. The increase of transmit power occurs at a time slightly later than t 0 . The increased transmit power compensates the path loss due to fast fading. The signal power received at the base station 100 returns to the pre fast-fading-dip level as shown in FIG. 2( b ).
[0021] When the transmit power of the wireless device 200 is increased, the interference on the neighboring cell increases as well. Thus, during fast fading events, the uplink transmissions from the wireless device 200 may interfere with the radio communication in neighboring cells. The transmit power of the wireless device 200 may be increased as much as 30 dB during the fading event, which would generate strong interference in the neighboring cell. In exemplary embodiments of the present disclosure, the wireless device 200 may be configured to limit the transmit power during fast fading event to mitigate interference caused by the wireless device 200 . In some embodiments, the wireless device 200 calculates a slot transmit power for an uplink transmission based on the directions or commands from the base station 100 . The wireless device 200 compares the calculated slot transmit power to an average transmit power of the wireless device 200 over a predetermined period. Based on the comparison, the wireless device 200 adjusts a transmission parameter to reduce the required slot transmit power to avoid creating excessive interference. Under normal conditions, the wireless device 200 uses the calculated slot transmit power for its uplink transmission. During a fast fading event, the wireless device 200 uses an adjusted slot transmit power.
[0022] FIG. 3 illustrates an exemplary method implemented at the wireless device 200 for modifying a normal link adaptation process to limit interference during fast fading events. The modified link adaptation process may be used to limit a fast fading compensation. In FIG. 3 , the wireless device 200 calculates a slot transmit power for transmitting a radio signal on a radio channel (Step 310 ), and calculates an average transmit power (Step 320 ). The wireless device 200 then derives a transmission parameter based on a comparison of the slot transmit power and the average transmit power (Step 330 ). The transmission parameter is used by the wireless device 200 to transmit a data packet (Step 340 ).
[0023] To determine an average transmit power, the wireless device 200 filters its transmit power on an uplink Dedicated Packet Control Channel (DPCCH). In one embodiment, the wireless device 200 calculates a filtered transmit power as follows:
[0000] P TX — filter ( n )α* P TX — filter ( n− 1)+(1−α)* P TX — measured ( n ) Eq (1)
[0000] where P TX — filter (n) represents the filtered DPCCH transmit power at time interval n. P TX — filter (n−1) represents the filtered DPCCH transmit power at time interval n−1. P TX — measured (n) represents the measured DPCCH transmit power at time interval n. The weighting factor α determines the length of the filter. The larger the weighting factor α is, the longer the length of the filter becomes. The weighting factor α may be determined by the base station 100 and signaled to the wireless device 200 over a control channel. The weighting factor α may be broadcast to the wireless device 200 . Alternatively, the weighting factor α may be determined and signaled by a radio network controller (RNC) via Radio Resource Control (RRC) signaling. Alternatively, the weighting factor α may be hard-coded in the wireless device 200 . The filtered transmit power at time interval n, P TX — filter (n), represents an average transmit power.
[0024] The wireless device 200 compares the filtered transmit power at time interval n with the calculated slot transmit as determined by inner loop power control to detect an increase in the slot transmit power. For example, the wireless device 200 may calculate a transmit power ratio R transmit — power according to:
[0000]
R
transmit
_
powe
r
=
P
slot
_
transmit
_
power
P
TX
_
filte
r
(
n
)
Eq
.
(
2
)
[0000] The transmit power ratio R transmit — power given by Eq. (2) reflects how much the slot transmit power deviates from the average transmit power. The wireless device 200 compares the transmit power ratio R transmit — power to a threshold. Based on the comparison, the wireless device 200 determines whether to modify a normal link adaptation process and apply a restriction on the fast fading compensation. For example, the wireless device 200 may compute a new transmission parameter based on this ratio.
[0025] There are several different approaches that can be used to limit the interference that would otherwise occur in response to a fast fading dip. In one approach, the wireless device 200 modifies a normal link adaptation process by reducing or limiting the data rate/transport format determined by the normal link adaptation process. The data rate/transport format may be a data rate/transport format on a data channel, e.g., an Enhanced Data Packet Data Channel (E-DPDCH). Limiting the data rate means that fewer bits will be transmitted reducing the total interference towards neighboring cells. In another approach, the wireless device 200 reduces or limits the total energy or power used for data transmission on an E-DPDCH. Both approaches are explained in detail below.
[0026] In some embodiments, the wireless device 200 adjusts the data rate for the uplink transmission in order to limit the transmit power increase that would have occurred during a normal link adaptation process. To adjust the data rate, the wireless device 100 calculates a rate correction factor based on the transmit power ratio R transmit — power and uses the rate correction factor CF to calculate the data rate/transport format for the uplink transmission. The rate correction factor CF may be calculated according to:
[0000] CF =max(1; k*R transmit — power ). Eq. (3)
[0000] The data rate R may then be calculated according to:
[0000]
R
=
max
(
R
normal
C
F
;
min_rate
)
,
Eq
.
(
4
)
[0000] where R normal is the normal data rate that would have been selected without compensation for fast fading, min_rate is the lowest data rate that is allowable, and k is a constant used to scale the ratio of the slot transmit power to the average transmit power. The constant k controls the extent to which the data rate in the transport format should be restricted. It is noted that in general higher data rate means higher transmit power. The constant k limits the fast fading compensation. The data rate R may be used to select the transport format. Both the min_rate and the constant k may be provided to the wireless device 200 by the base station 100 over a control channel. The two parameters can be broadcast to the wireless device 100 . Alternatively, a radio network controller may determine the min_rate and constant k and provide them to the wireless device 100 via RRC signaling. In some embodiments, these two parameters can also be hardcoded in the wireless device 200 as well.
[0027] In some embodiments, the rate correction factor CF may be provided to the transport format selection function for the wireless device 200 . In this case, the selection function uses the rate correction factor CF as a scaling factor to scale the available power headroom. The scaled available power headroom is then used to perform a data rate/transport format selection. In one exemplary scenario, when there is an increase in the ratio of the slot transmit power to the average transmit power, the scaling factor increases the available power headroom. More reserved power headroom restricts the maximum transmit power available for the wireless device 200 . This in turn would limit the data rate in the selected transport format.
[0028] In other embodiments, rather than adjusting the data rate/transport format, the wireless device 200 uses the transmit power ratio R transmit — power to directly adjust the transmit power on the Enhanced Data Packet Data Channel (E-DPCCH). To adjust the transmit power for the E-DPCCH, the wireless device 100 calculates a power correction factor based on the transmit power ratio R transmit — power . The power correction factor PCF may be calculated according to:
[0000]
P
C
F
=
max
(
min
(
1
;
y
*
1
R
transmit
_
power
)
;
min_PCF
)
,
Eq
.
(
5
)
[0000] where y is a constant that controls how much the E-DPCCH transmit power should be restricted, and min_PCF represents the smallest value the power correction factor PCF can take. min_PCF also reflects the largest power reduction that the wireless device 200 is allowed to make when restricting the change in E-DPCCH transmit power. The modified E-DPCCH transmit power may then be calculated according to:
[0000] P E-DPCCH =PCF*P normal — E-DPCCH , Eq. (6)
[0000] where P normal — E-DPCCH represents the power level that should be selected without any fast fading power limitation.
[0029] FIG. 4 illustrates an exemplary wireless device 200 configured to modify a link adaptation process as herein described. The wireless device 200 comprises a transceiver circuit 210 and a processing circuit 220 . The transceiver circuit 210 is configured to receive and transmit signals to and from a base station, e.g., the base station 100 . The processing circuit 220 is configured to modify a link adaptation process. The processing circuit 220 may comprise a link adaptation circuit 230 and a correction circuit 240 . The link adaptation circuit 230 is configured to select a normal transport format for the wireless device's uplink transmissions. In some scenarios, the normal transport format reflects a fast fading compensation. The correction circuit 240 is configured to modify the transport format selected by the link adaptation circuit 230 . The correction circuit 240 is configured to determine a slot transmit power for transmitting a radio signal on a radio channel. The correction circuit 240 calculates an average transmit power and derives a transmission parameter based on a comparison of the slot transmit power and the average transmit power. The derived transmission parameter is used by the wireless device 200 to transmit a data packet.
[0030] In some embodiments, the base station 100 may set conditions on when the wireless device 200 can restrict a fast fading compensation. For example, the base station 100 may decide that the wireless device 200 only applies a fast fading restriction when the measured path loss of an uplink transmission is larger than a threshold. Alternatively, the wireless device 200 may apply a fast fading restriction only when the wireless device 200 is transmitting above a pre-determined minimum power level. The path loss threshold and the pre-determined minimum power level may be transmitted to the wireless device 200 by the base station 100 . These two parameters may be broadcast to the wireless device 200 . Alternatively, a radio network controller may determine and transmit the path loss threshold and the pre-determined minimum power level to the wireless device 200 via RRC signaling. The path loss threshold and the pre-determined power level may be hard-coded in the wireless device 200 as well. As described above, the modified transmit power may represent a fast fading restriction imposed by the wireless device 200 to reduce or limit the increase of transmit power for fast fading compensation. In a fast fading restriction, one or more controlling parameters determine how large and/or when a fast fading restriction should be applied. For example, the path loss threshold, the pre-determined minimum power level, min_rate, constant k, min_PCF and constanty are all controlling parameters the wireless device 200 relies on to modify a normal link adaptation process. Those controlling parameters are determined and transmitted to the wireless device 200 by a radio network, either from a RNC node (via a base station) or directly from a base station, e.g., the base station 100 . An exemplary base station 100 configured to control a modified link adaptation process of the wireless device 200 is illustrated in FIG. 5 .
[0031] The base station 100 comprises a transceiver circuit 110 and a processing circuit 120 . The transceiver circuit 110 is configured to transmit data and control signals to the wireless device 200 . The processing circuit 120 is configured to determine one or more controlling parameters and transmit the one or more controlling parameters for the wireless device 200 to use in modifying a link adaptation process. The one or more controlling parameters may be transmitted to the wireless device 200 via RRC signaling or broadcasting.
[0032] FIG. 6 illustrates an exemplary method 400 implemented at the base station 100 for controlling a modified link adaptation process at the wireless device 200 . The base station 100 determines one or more controlling parameters for the wireless device (Step 410 ). The base station 100 then transmits the one or more controlling parameters to the wireless device to control a modified link adaptation process at the wireless device 200 (Step 420 ). Examples of the one or more controlling parameters include the path loss threshold, the pre-determined minimum power level, min_rate, constant k, min_PCF, and constant y, all described in detail in the above discussion.
[0033] It is noted that some or all of the above mentioned controlling parameters may be hardcoded in the wireless device 200 as well.
[0034] It is also noted that a radio network controller may be configured to determine the one or more controlling parameters for the wireless device 200 and transmit the one or more controlling parameters to the wireless device 200 via RRC signaling. The radio network controller may comprise a network interface for communicating with the base station 100 and a processing circuit for determining the one or more controlling parameters. The one or more controlling parameters are sent to the base station 100 via the network interface for transmitting to the wireless device 200 .
[0035] It is further noted that in some embodiments, other types of network nodes, such as eNBs, NodeBs, access nodes, etc., may be configured to control the wireless device 200 to modify a link adaptation process at the wireless device 200 .
[0036] When a fast fading restriction is applied, the modified link adaptation process does not fully compensate for fast fading dips. This may result in a lower data transmission rate. Or it may lead to increased re-transmission attempts. The effect of both consequences is that some data may be transmitted at a different time using different resources, for example, when the fast fading has subsided. The wireless device 200 avoids inefficient resource-utilization during fast-fading and arranges data transmission at another time when the channel conditions have improved. Another advantage of fast fading restriction is reduced interference level as experienced by neighboring cells during fast fading in cell A, which would lead to an improved overall system performance, especially in a multi-user multi-cell scenario. Fast fading restriction also lowers or limits the transmit power of the wireless device 200 , allowing the wireless device 200 to conserve battery power and extend the battery life.
[0037] The present invention may, of course, be carried out in other ways than those specifically set forth herein without departing from essential characteristics of the invention. The present embodiments are to be considered in all respects as illustrative and not restrictive, and all changes coming within the meaning and equivalency range of the appended claims are intended to be embraced therein. | The present application discloses methods and apparatus for modifying a normal link adaptation process of a wireless device ( 200 ). The normal link adaptation process may be used to compensate for a fast fading dip detected by a base station ( 100 ). The present application teaches that the normal fast fading compensation may cause inter-cell interference and degrade system performance. The present application discloses imposing a fast fading restriction or limitation on the normal fast fading compensation can reduce inter-cell interference, improve system capacity, and extends the battery life of the wireless device. | 7 |
The present application claims the benefit of priority under 35 USC §119(e) to U.S. Provisional Patent Application 61/187,302 entitled “Anti-michotic Wallboard Tape”, filed Jun. 16, 2009, which is hereby incorporated, in its entirety, herein by reference.
FIELD OF THE INVENTION
This invention relates to paper products and/or substrates suitable for being made into wallboard tape (also may be known as joint tape and/or drywall tape) and having improved reduction or inhibition in the growth of microbes, mold and/or fungus. The paper substrate is characterized by its excellent physical properties including cross direction (CD) tensile, machine (MD) tensile, internal bond, wet tensile, hygroexpansivity, curl, bonding properties, bonding of joint tape to joint compound, etc. The paper product of the invention contains a sizing agent and an antimicrobial compound as well as other optional components including without limitation a binder. The paper product of the invention may be produced by contacting the plurality of cellulose fibers with each of the sizing agent, antimicrobial compound, and optional components at any point in the papermaking process, converting process, and/or post-converting process. Finally, the invention relates to methods of using the paper substrate.
BACKGROUND OF THE INVENTION
Wallboard (also known as drywall) has become the dominant material in the production of interior building partitions. In particular, interior building partitions generally comprise a studwall of spaced parallel vertical members (studs) which are used as a support for preformed panels (wallboard) which are attached to the studwall by screws, nails, adhesive or any other conventional attachment system. Obviously, joints exist between adjacent preformed panels. In order to provide a continuous flat surface to the wall, it is necessary to “finish” the joint between adjacent panels. Generally, such “finishing” may include the building up of multiple layers of a mastic material (joint compound) and the blending of this joint compound and paper substrate suitable for wallboard tape utility into the panel surface so as to form the desired flat and contiguous wall surface. In addition, wallboard tape may be used to bring together a plurality of panels forming a corner which may include but is not limited to corner bead.
In order to facilitate this finishing of the joints and/or corners, most manufacturers bevel the longitudinal edges of the wallboard panels so as to allow a build-up of mastic material which will then match the level of the major surface area of the preformed panel. Typically, the buildup of the mastic material in the joint area comprises the application of a first layer of mastic material, the embedding of a wallboard tape (for example a paper tape) in the first layer of mastic material and then the overcoating of the tape with one or more, generally two layers of additional mastic material. This finishing of the joints is a time consuming process, since it is generally necessary to wait 24 hours between each application of a coat of mastic material in order to allow the coat to dry before the application of an overcoat of an additional layer of mastic material. Moreover, it is then necessary generally to sand the joint area so as to produce a finish which will match the major portion of the surface area of the wallboard panels. The “finishing” process thus is both time-consuming and labor-intensive.
In addition to the above, it is desirable to, create building materials that are antimicrobial so that they resist or inhibit the growth of microbes such as bacteria, fungus, molds, and mildew.
Wallboard tape paper is a very challenging paper to make as there is a very narrow window of operation in which to achieve the required high tensile strengths while maintaining other good physical properties such as bonding properties, bonding of joint tape to joint compound, hygroexpansivity, curl, etc. The challenge to the next generation of wallboard tape paper substrate production is to program an addition antimicrobial function into what is already a very specific and stringent set of physical properties such as CD tensile, MD tensile, internal bond, wet tensile, hygroexpansivity, curl, bonding properties, bond of joint tape to joint compound, etc (which are demanded by wallboard tape paper substrate converters and users). Such levels of physical properties such as CD tensile, MD tensile, internal bond, wet tensile, hygroexpansivity, curl, bonding properties, bond of joint tape to joint compound, etc, have been achieved by conventional production of paper substrates under acidic conditions and alkaline conditions. However, an alkaline paper substrate suitable for wallboard tape converting (e.g. have acceptable physical properties such as CD tensile, MD tensile, internal bond, wet tensile, hygroexpansivity, curl, bonding properties, bond of joint tape to joint compound, etc) has been difficult to achieve.
Despite the considerable efforts, there exists a need for a wallboard tape to satisfy the construction industries' requirements wallboard tape having highly sought after physical properties and maintain sustainable antimicrobial properties.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 : A first schematic cross section of just one exemplified embodiment of the paper substrate that is included in the paper substrate of the present invention.
FIG. 2 : A second schematic cross section of just one exemplified embodiment of the paper substrate that is included in the paper substrate of the present invention.
FIG. 3 : A third schematic cross section of just one exemplified embodiment of the paper substrate that is included in the paper substrate of the present invention.
FIG. 4 : A first pictorial representation of how wallboard and tape samples were tested for antimicrobial performance according to Example 1.
FIG. 5 : A second pictorial representation of how wallboard and tape samples were tested for antimicrobial performance according to Example 1.
FIG. 6 : A photograph showing the antimicrobial performance of Sample A after 62 days as measured by the process of Example 1.
FIG. 7 : A photograph showing the antimicrobial performance of Sample B after 62 days as measured by the process of Example 1.
FIG. 8 : A photograph showing the antimicrobial performance of Sample C after 62 days as measured by the process of Example 1.
FIG. 9 : A photograph showing the antimicrobial performance of Sample D after 62 days as measured by the process of Example 1.
FIG. 10 : A photograph showing the antimicrobial performance of Sample E after 62 days as measured by the process of Example 1.
FIG. 11 : A photograph showing the antimicrobial performance of Sample F after 62 days as measured by the process of Example 1.
FIG. 12 : A photograph showing the antimicrobial performance of Sample G after 62 days as measured by the process of Example 1.
FIG. 13 : A photograph showing the antimicrobial performance of Sample H after 62 days as measured by the process of Example 1.
DETAILED DESCRIPTION OF THE INVENTION
The present inventors have now discovered a paper substrate which, until now, was unable to meet the stringent physical properties required by the construction industries for useful wallboard tape application that also has sustainable antimicrobial properties, as well as methods of making and using the same.
The paper substrate of the present invention may contain recycled fibers and/or virgin fibers. Recycled fibers differ from virgin fibers in that the fibers have gone through the drying process at least once.
The paper substrate of the present invention may contain from 1 to 99 wt % of cellulose fibers based upon the total weight of the substrate, including 1, 5, 10, 15, 20, 25, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75, 80, 85, 90, 95 and 99 wt %, and including any and all ranges and subranges therein.
Preferably, the sources of the cellulose fibers are from softwood and/or hardwood. The paper substrate of the present invention may contain from 1 to 99 wt %, preferably from 5 to 95 wt %, cellulose fibers originating from softwood species based upon the total amount of cellulose fibers in the paper substrate. This range includes 5, 10, 15, 20, 25, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75, 80, 85, 90, 95, and 100 wt %, including any and all ranges and subranges therein, based upon the total amount of cellulose fibers in the paper substrate.
The paper substrate of the present invention may contain from 1 to 99 wt %, preferably from 5 to 95 wt %, cellulose fibers originating from hardwood species based upon the total amount of cellulose fibers in the paper substrate. This range includes 5, 10, 15, 20, 25, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75, 80, 85, 90, 95, and 100 wt %, including any and all ranges and subranges therein, based upon the total amount of cellulose fibers in the paper substrate.
Further, the softwood and/or hardwood fibers contained by the paper substrate of the present invention may be modified by physical and/or chemical means. Examples of physical means include, but is not limited to, electromagnetic and mechanical means. Means for electrical modification include, but are not limited to, means involving contacting the fibers with an electromagnetic energy source such as light and/or electrical current. Means for mechanical modification include, but are not limited to, means involving contacting an inanimate object with the fibers. Examples of such inanimate objects include those with sharp and/or dull edges. Such means also involve, for example, cutting, kneading, pounding, impaling, etc means.
Examples of chemical means include, but is not limited to, conventional chemical fiber modification means. Examples of such modification of fibers may be, but is not limited to, those found in the following U.S. Pat. Nos. 6,592,717, 6,582,557, 6,579,415, 6,579,414, 6,506,282, 6,471,824, 6,361,651, 6,146,494, H1,704, 5,698,688, 5,698,074, 5,667,637, 5,662,773, 5,531,728, 5,443,899, 5,360,420, 5,266,250, 5,209,953, 5,160,789, 5,049,235, 4,986,882, 4,496,427, 4,431,481, 4,174,417, 4,166,894, 4,075,136, and 4,022,965, which are hereby incorporated in their entirety by reference.
The paper substrate of the present invention may contain an antimicrobial compound. The paper substrate's antimicrobial tendency may be measured in part by ASTM standard testing methodologies such as D 2020-92, E 2180-01, G 21-966, C1338, and D2020, all of which can be found as published by ASTM and all of which are hereby incorporated, in their entirety, herein by reference.
Antimycotics, fungicides are examples of antimicrobial compounds. Antimicrobial compounds may retard, inhibit, reduce, and/or prevent the tendency of microbial growth over time on/in a product containing such compounds as compared to that tendency of microbial growth on/in a product not containing the antimicrobial compounds. The antimicrobial compound when incorporated into the paper substrate of the present invention preferably retards, inhibits, reduces, and/or prevents microbial growth for a time that is at least 5, 10, 15, 20, 25, 30, 35, 40, 45, 50, 75, 100, 125, 150, 200, 250, 300, 350, 400, 450, 500, 550, 600, 700, 800, 900, 1000% greater than that of a paper substrate that does not contain an antimicrobial compound, including all ranges and subranges therein.
Antimycotic compounds are, in part, mold resistant. Fungicide compounds are, in part, fungus resistant. The antimicrobial compound may have other functions and activities than provide either mold resistance and/or fungus resistance to a product containing the same.
The antimicrobial compound may also be mildew, bacteria and/or virus resistant. A mold specifically targeted, but meant to be non-limiting, is Black mold as applied to the above-mentioned paper substrate of the present invention.
It is preferable for the antimycotic and/or fungicide to not be highly toxic to humans.
The antimycotic and/or fungicide may be water insoluble and/or water soluble, most preferably water insoluble. The antimycotic and/or fungicide may be volatile and/or non-volatile, most preferably non-volatile. The antimycotic and/or fungicide may be organic and/or inorganic. The antimycotic and/or fungicide may be polymeric and/or monomeric.
The antimycotic and/or fungicide may be multivalent which means that the agent may carry one or more active compounds so as to protect against a wider range of mold, mildew and/or fungus species and to protect from evolving defense mechanisms within each species of mold, mildew and/or fungus.
Any water-soluble salt of pyrithione having antimicrobial properties is useful as the antimicrobial compound. Pyrithione is known by several names, including 2 mercaptopyridine-N-oxide; 2-pyridinethiol-1-oxide (CAS Registry No. 1121-31-9); 1-hydroxypyridine-2-thione and 1 hydroxy-2(1H)-pyridinethione (CAS Registry No. 1121-30-8). The sodium derivative, known as sodium pyrithione (CAS Registry No. 3811-73-2), is one embodiment of this salt that is particularly useful. Pyrithione salts are commercially available from Arch Chemicals, Inc. of Norwalk, Conn., such as Sodium OMADINE or Zinc OMADINE.
Examples of the antimicrobial compound may include silver-containing compound, zinc-containing compound, an isothiazolone-containing compound, a benzothiazole-containing compound, a triazole-containing compound, an azole-containing compound, a benzimidazol-containing compound, a nitrile containing compound, alcohol-containing compound, a silane-containing compound, a carboxylic acid-containing compound, a glycol-containing compound, a thiol-containing compound or mixtures thereof.
Additional exemplified commercial antimicrobial compounds may include those from Intace including B-6773 and B-350, those from Progressive Coatings VJ series, those from Buckman Labs including Busan 1218, 1420 and 1200 WB, those from Troy Corp including Polyphase 641, those from Clariant Corporation, including Sanitized TB 83-85 and Sanitized Brand T 96-21, and those from Bentech LLC including Preservor Coater 36. Others include AgION (silver zeolite) from AgION and Mircroban from Microban International (e.g. Microban additive TZ1, S2470, and PZ2). Further examples include dichloro-octyl-isothiazolone, Tri-n-butylin oxide, borax, G-4, chlorothalonil, organic fungicides, and silver-based fungicides. Any one or more of these agents would be considered satisfactory as an additive in the process of making paper material. Further commercial products may be those from AEGIS Environments (e.g. AEM 5772 Antimicrobial), from BASF Corporation (e.g. propionic acid), from Bayer (e.g. Metasol TK-100, TK-25), those from Bendiner Technologies, LLC, those from Ondei-Nalco (e.g. Nalcon 7645 and 7622), and those from Hercules (e.g. RX8700, RX3100, and PR 1912). The MSDS's of each and every commercial product mentioned above is hereby incorporated by reference in its entirety.
Still further, examples of the antimicrobial compounds may include silver zeolite, dichloro-octyl-isothiazolone, 4,5-dichloro-2-n-octyl-3(2H)-isothiazolone, 5-chloro-2-methyl-4-isothiazolin-3-one, 1,2-benzothiazol-3(2H)-one, poly[oxyethylene(ethylimino)ethylene dichloride], Tri-n-butylin oxide, borax, G-4, chlorothalonil, Alkyl-dimethylbenzyl-ammonium saccharinate, dichloropeyl-propyl-dioxolan-methlyl-triazole, alpha-chlorphenyl, ethyl-dimethylethyl-trazole-ethanol, benzimidazol, 2-(thiocyanomethylthio)benzothiazole, alpha-2(-(4-chlorophenyl)ethyl)-alpha-(1-1-dimethylethyl)-1H-1,2,4-triazole-1-ethanol, (1-[[2-(2,4-dichlorophenyl)-4-propyl-1,3-dioxolan-2-yl]-methyl]-1H-1,2,4-triazole, alkyl dimethylbenzyl ammonium saccharinate, 2-(methoxy-carbamoyl)-benzimidazol, tetracholorisophthalonitrile, P-[(diiodomethyl) sulfonyl]toluol, methyl alcohol, 3-(trimethoxysilyl) propyldimethyl octadecyl ammonium chloride, chloropropyltrimethylsilane, dimethyl octadecyllamine, propionic acid, 2-(4-thiazolyl)benzimidazole, 1,2-benzisothiazolin-3-one, 2-N-octyl-4-isothiazolin-3-one, diethylene glycol monoethyl ether, ethylene glycol, propylene glycol, hexylene glycol, tributoxyethyl phosphate, 2-pyridinethio-1-oxide, potassium sorbate, diiodomethyl-p-tolysulfone, citric acid, lemon grass oil, and thiocyanomethylhio-benzothiazole.
The antimicrobial compound may be present in the paper substrate at amounts from 1 to 5000 ppm dry weight, more preferably, from 100 to 3000 ppm thy weight, most preferably 50 to 1500 ppm dry weight. The amounts of antimycotic and/or fungicide may be 2, 5, 10, 25, 50, 75, 100, 12, 150, 175, 200, 225, 250, 275, 300, 325, 350, 375, 400, 425, 450, 475, 500, 600, 700, 800, 900, 1000, 1100, 1200, 1300, 1400, 1500, 1600, 1700, 1800, 1900, 2000, 2100, 2200, 2300, 2400, 2500, 2600, 2700, 2800, 2900, 3000, 3200, 3500, 3750, 4000, 4250, 4500, 4750, and 5000 ppm dry weight based upon the total weight of the paper substrate, including all ranges and subranges therein. Higher amounts of such antimycotic and/or fungicide may also prove produce an antibacterial paper material and article therefrom as well. These amounts are based upon the total weight of the paper substrate.
The paper substrate of the present invention may contain at least one sizing agent. Examples of the sizing agent may be, but is not limited to, alkaline sizing agents and acid-based sizing agents. Examples of alkaline sizing agents include without limitation unsaturated hydrocarbon compounds, such as C6 to C24, preferably C18 to C20, unsaturated hydrocarbon compounds and mixtures thereof. Examples of acid-based sizing agents include without limitation alum and rosin-based sizing agents such as Plasmine N-750-P from Pasmine Technology Inc.
FIGS. 1-3 demonstrate different embodiments of the paper substrate 1 in the paper substrate of the present invention. FIG. 1 demonstrates a paper substrate 1 that has a web of cellulose fibers 3 and a composition containing an antimicrobial compound 2 where the composition containing an antimicrobial compound 2 has minimal interpenetration of the web of cellulose fibers 3 . Such an embodiment may be made, for example, when an antimicrobial compound is coated onto a web of cellulose fibers during or after papermaking and/or during or after converting the substrate to a useful wallboard tape and/or during or after abrading (such as sanding) the surface of the substrate.
FIG. 2 demonstrates a paper substrate 1 that has a web of cellulose fibers 3 and a composition containing an antimicrobial compound 2 where the composition containing an antimicrobial compound 2 interpenetrates the web of cellulose fibers 3 . The interpenetration layer 4 of the paper substrate 1 defines a region in which at least the antimicrobial compound penetrates into and is among the cellulose fibers. The interpenetration layer may be from 1 to 99% of the entire cross section of at least a portion of the paper substrate, including 1, 2, 5, 10, 15, 20, 25, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75, 80, 85, 90, 95, and 99% of the paper substrate, including any and all ranges and subranges therein. Such an embodiment may be made, for example, when an antimicrobial compound is added to the cellulose fibers prior to a coating method and may be combined with a subsequent coating method if required. Addition points may be at the size press, for example.
FIG. 3 demonstrates a paper substrate 1 that has a web of cellulose fibers 3 and an antimicrobial compound 2 where the antimicrobial compound 2 is approximately evenly distributed throughout the web of cellulose fibers 3 . Such an embodiment may be made, for example, when an antimicrobial compound is added to the cellulose fibers prior to a coating method and may be combined with a subsequent coating method if required. Exemplified addition points may be at the wet end of the paper making process, the thin stock, and the thick stock.
The web of cellulose fibers and the antimicrobial compound may be in a multilayered structure. The thicknesses of such layers may be any thickness commonly utilized in the paper making industry for a paper substrate, a coating layer, or the combination of the two. The layers do not have to be of approximate equal size. One layer may be larger than the other. One preferably embodiment is that the layer of cellulose fibers has a greater thickness than that of any layer containing the antimicrobial compound. The layer containing the cellulose fibers may also contain, in part, the antimicrobial compound.
Further examples of sizing agents that may be incorporated into the present invention may include, but is not limited to, those found in the following patents: U.S. Pat. Nos. 6,595,632, 6,512,146, 6,316,095, 6,273,997, 6,228,219, 6,165,321, 6,126,783, 6,033,526, 6,007,906, 5,766,417, 5,685,815, 5,527,430, 5,011,741, 4,710,422, and 4,184,914, which are hereby incorporated in their entirety by reference. Preferred alkaline sizing agent may be, but not limited to, alkyl ketene dimer, alkenyl ketene dimer and alkenyl succinic anhydride.
The paper substrate of the present invention may contain from 0.05 to 1.5 wt % of the alkaline sizing agent based upon the total weight of the substrate. This range includes 0.05, 0.06, 0.07, 0.08, 0.09, 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, 1.0, 1.1, 1.2, 1.3, 1.4, and 1.5 wt %, including any and all ranges and subranges therein.
The paper substrate of the present invention may have a MD tensile as measured by conventional TAPPI method 494 of from 25 to 100, preferably from 40 to 90 lbf/inch width. This range includes MD tensile of 25, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75, 80, 85, 90, 95, and 100 lbf/inch width, including any and all ranges and subranges therein.
The paper substrate of the present invention may have a CD tensile as measured by conventional TAPPI method 494 of from 5 to 50, preferably from 20 to 50 lbf/inch width, most preferably 25 to 40 lbf/inch width. This range includes CD tensile of 5, 10, 15, 20, 25, 30, 35, 40, 45, and 50 lbf/inch width, including any and all ranges and subranges therein.
The paper substrate of the present invention may have a wet strength as measured by conventional TAPPI method 456 of from 5 to 50, preferably from 10 to 25, most preferably from 15 to 25, lb/inch width. This range includes wet strengths of 5, 10, 15, 20, 25, 30, 35, 40, 45, and 50 lb/inch width, including any and all ranges and subranges therein.
The paper substrate of the present invention may have an internal bond as measured by conventional TAPPI method 541 of from 25 to 350, preferably from 50 to 250, most preferably from 100-200, milli ft-lb/sq. in. This range includes internal bond of 25, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75, 80, 85, 90, 95, 100, 110, 125, 150, 175, 200, 225, 250, 275, 300, 325 and 350 milli ft-lb/sq. in, including any and all ranges and subranges therein.
The paper substrate of the present invention may have a pH of at least about 1.0 to about 14.0 as measured by any conventional method such as a pH marker/pen and conventional TAPPI methods 252 and 529 (hot extraction test and/or surface pH test). The pH of the paper may be from about 1.0 to 14.0, preferably about 4.0 to 9.0, most preferably from about 6.5 to 8.5. This range includes pHs of 1.0, 2.0, 3.0, 4.0, 5.0, 6.0 6.5, 6.6, 6.7, 6.8, 6.9, 7.0, 7.1, 7.2, 7.3, 7.4, 7.5, 7.6, 7.7, 7.8, 7.9, 8.0, 8.1, 8.2, 8.3, 8.4, 8.5, 8.6, 8.7, 8.8, 8.9, 9.0, 9.2, 9.4, 9.5, 9.6, 9.8, 10.0, 10.5, 11.0, 11.5, 12.0, 12.5, 13.0, 13.5, and 14.0, including any and all ranges and subranges therein.
The density, basis weight and caliper of the web of this invention may vary widely and conventional basis weights, densities and calipers may be employed depending on the paper-based product formed from the web.
The paper substrate according to the present invention may be made off of the paper machine having a basis weight of from 50 lb/3000 sq. ft. to 120 lb/3000 sq. ft, preferably from 70 to 120, and most preferably from 80-100 lb/3000 sq. ft. The basis weight of the substrate may be 50, 52, 54, 55, 56, 58, 60, 62, 64, 65, 66, 68, 70, 72, 74, 75, 76, 78, 80, 82, 84, 85, 86, 88, 90, 92, 94, 95, 96, 98, 100, 105, 110, 115 and 120 lb/3000 sq. ft, including any and all ranges and subranges therein.
The paper substrate according to the present invention may be made off of the paper machine having an apparent density of from 5.0 to 20.0, preferably 9.0 to 13.0, most preferably from 9.5 to 11.5, lb/3000 sq. ft. per 0.001 inch thickness. The apparent density of the substrate may be 5.0, 5.2, 5.4, 5.5, 5.6, 5.8, 6.0, 6.2, 6.4, 6.5, 6.6, 6.8, 7.0, 7.2, 7.4, 7.5, 8.0, 8.5, 9.0, 9.5, 10.0, 10.5, 11.0, 11.5, 12.0, 12.5, 13.0, 13.5, 14.0, 14.5, 15.0, 15.5, 16.0, 16.5, 17.0, 17.5, 18.0, 18.5, 19.0, 19.5 and 20.0 lb/3000 sq. ft. per 0.001 inch thickness, including any and all ranges and subranges therein.
The paper substrate according to the present invention may have a width off the winder of a paper machine of from 5 to 100 inches and can vary in length. The width of the paper substrate may be 5, 10, 15, 20, 25, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75, 80, 85, 90, 95, 100 inches, including any and all ranges and subranges therein.
Additionally, the paper substrate according to the present invention may be cut into streamers that have a width of from 1.5 to 3.25 inches wide and may vary in length. The width of the paper substrate streamer may have a width of 1.50, 1.60, 1.70, 1.75, 1.80, 1.85, 1.9, 1.95, 2.00, 2.10, 2.20, 2.30, 2.40, 2.50, 2.60, 2.70, 2.80, 2.90, 3.00, 3.05, 3.10, 3.15, 3.20, and 3.25 inches, including any and all ranges and subranges therein.
The paper substrate of the present invention may contain optional components as well including but not limited to binders, wet strength additives, and anionic promoters.
One optional component that is included as one embodiment of the paper substrate of the present invention includes without limitation a binder. Examples of binders include, but are not limited to, polyvinyl alcohol, Amres (a Kymene type), Bayer Parez, polychloride emulsion, modified starch such as hydroxyethyl starch, starch, polyacrylamide, modified polyacrylamide, polyol, polyol carbonyl adduct, ethanedial/polyol condensate, polyimide, epichlorohydrin, glyoxal, glyoxal urea, ethanedial, aliphatic polyisocyanate, isocyanate, 1,6 hexamethylene diisocyanate, diisocyanate, polyisocyanate, polyester, polyester resin, polyacrylate, polyacrylate resin, acrylate, and methacrylate. When the substrate of the present invention contains a binder, preferable binders include without limitation starch and polyvinyl alcohol.
When the substrate of the present invention contains a binder, the substrate may include any amount of binder including less than 5% of binder, This range includes less than 0.001, 0.002, 0.005, 0.006, 0.008, 0.01, 0.02, 0.03, 0.04, 0.05, 0.1, 0.2, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, 1, 2, 4, and 5 wt % based on the total weight of the substrate, including any and all ranges and subranges therein.
One optional component that is included as one embodiment of the paper substrate of the present invention includes without limitation a wet strength additive. The paper substrate of the present invention may contain at least one wet strength additive. The wet strength additive may be cationic, anionic, neutral, and amphoteric. A preferred wet strength additive is cationic and/or contains a basic functional group. Examples of the wet strength additive may be, but is not limited to, polymeric amine epichlorohydrin (PAE), urea formaldehyde, melamine formaldehyde and glyoxylated polyacrylamide resins. Further examples of wet strength additives that may be incorporated in to the present invention may include, but is not limited to, those found in the following patents: U.S. Pat. Nos. 6,355,137 and 6,171,440, which are hereby incorporated in their entirety by reference. Preferred wet strength additives include, but are not limited to, polymeric amine epichlorohydrin (PAE).
The paper substrate of the present invention may contain from 0.25 to 2.5 wt % of the wet strength additive based upon the total weight of the substrate. This range includes 0.25, 0.30, 0.35, 0.40, 0.45, 0.50, 0.6, 0.7, 0.8, 0.9, 1.0, 1.1, 1.2, 1.3, 1.4, 1.5, 1.6, 1.7, 1.8, 1.9, 2.0, 2.1, 2.2, 2.3, 2.4 and 2.5 wt %, including any and all ranges and subranges therein.
One optional component that is included as one embodiment of the paper substrate of the present invention includes without limitation an anionic promoter. The paper substrate of the present invention may contain at least one anionic promoter. Examples of the anionic promoter may be, but is not limited to, polyacrylates, sulfonates, carboxymethyl celluloses, galactomannan hemicelluloses and polyacrylamides. Preferred anionic promoters include, but are not limited to polyacrylates such as Nalco 64873.
The paper substrate of the present invention may contain from 0.05 to 1.5 wt % of the anionic promoter based upon the total weight of the substrate. This range includes 0.05, 0.06, 0.07, 0.08, 0.09, 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, 1.0, 1.1, 1.2, 1.3, 1.4, and 1.5 wt %, including any and all ranges and subranges therein.
The paper substrate of the present invention may also optionally include inert substances including without limitation fillers, thickeners, and preservatives. Other inert substances include, but are not limited to silicas such as colloids and/or sols. Examples of silicas include, but are not limited to, sodium silicate and/or borosilicates. Another example of inert substances is solvents including but not limited to water. Examples of fillers include, but are not limited to; calcium carbonate, calcium sulfate hemihydrate, and calcium sulfate dehydrate. A preferable filler is calcium carbonate.
The paper substrate of the present invention may contain from 0.001 to 20 wt % of the inert substances based on the total weight of the substrate, preferably from 0.01 to 10 wt %, most preferably 0.1 to 5.0 wt %, of each of at least one of the inert substances. This range includes 0.001, 0.002, 0.005, 0.006, 0.008, 0.01, 0.02, 0.03, 0.04, 0.05, 0.1, 0.2, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, 1, 2, 4, 5, 6, 8, 10, 12, 14, 15, 16, 18, and 20 wt % based on the total weight of the substrate, including any and all ranges and subranges therein.
The paper substrate may be made by contacting a plurality of cellulose fibers with a antimicrobial compound and/or a sizing agent consecutively in any order and/or simultaneously. Further, the contacting may occur in an aqueous environment having a pH of from about 1.0 to about 14.0, preferably from about 6.8 to about 8.5. The pH may be 1.0, 2.0, 3.0, 4.0, 5.0, 6.0 6.5, 6.6, 6.7, 6.8, 6.9, 7.0, 7.1, 7.2, 7.3, 7.4, 7.5, 7.6, 7.7, 7.8, 7.9, 8.0, 8.1, 8.2, 8.3, 8.4, 8.5, 8.6, 8.7, 8.8, 8.9, 9.0, 9.2, 9.4, 9.5, 9.6, 9.8, 10.0, 10.5, 11.0, 11.5, 12.0, 12.5, 13.0, 13.5, and 14.0, including any and all ranges and subranges therein. Accordingly the paper substrate may be made using acidic, near neutral, neutral, or alkaline conditions.
Still further, the contacting may occur at acceptable concentration levels that provide the paper substrate of the present invention to contain any of the above-mentioned amounts of cellulose fibers, antimicrobial compound, sizing agent, optional components, and/or inert substances isolated or in any combination thereof. The contacting may occur anytime in the papermaking process including, but not limited to the thick stock, thin stock, head box, size press, water box, and coater. The cellulose fibers, antimicrobial compound, sizing agent, optional components, and/or inert substances may be contacted serially, consecutively, and/or simultaneously in any combination with each other. The cellulose fibers, antimicrobial compound, sizing agent, optional components, and/or inert substances may be pre-mixed in any combination before addition to the paper-making process.
These methods of making the paper substrate of the present invention may be added to any conventional papermaking processes, as well as converting processes, including abrading or sanding to create a fine nap for greater adhesion qualities, slitting, scoring, perforating, sparking, calendaring, sheet finishing, converting, coating, laminating, printing, etc. Preferred conventional processes include those tailored to produce paper substrates capable to be utilized as wallboard tape. Textbooks such as those described in the “Handbook for pulp and paper technologists” by G. A. Smook (1992), Angus Wilde Publications, describe such processes and is hereby incorporated, in its entirety, by reference.
In one embodiment, the cellulosic fibers and sizing agent may be contacted at anytime during papermaking with or without optional substances or inert substances. In such an embodiment, the cellulosic fibers and sizing agent are contacted at least at the wet end of the paper machine, then the web is dried to make a paper substrate suitable for use as wallboard tape. Optional substances and/or inert substances may optionally be added at anytime during papermaking including without limitation optionally adding the binder to the web using a size press. The substrate may be sanded creating a nap, preferably a fine nap, for greater adhesion qualities. The surface of the substrate carrying the nap may then be contacted with the antimicrobial compound. The contacting may occur using a size press or any coater apparatus including without limitation a spray coater apparatus. Within this embodiment, the optional components and/or inert substances may optionally be contacted with the surface of the substrate at the same time as the antimicrobial compound.
The present invention is explained in more detail with the aid of the following embodiment example which is not intended to limit the scope of the present invention in any manner.
EXAMPLES
Example 1
Materials
Handsheet Furnish: 100% refined southern softwood collected on Jul. 20, 2007
Sizing Agent: Plasmine N-750-P (40% solids)
Aluminum Sulfate (Alum): (40% consistency)
Wet Strength Agent: Poly(amido-amine)-epichlorohydrin (25% solids)
Antimicrobial Agent (A/M): Intace B350
Starch: Tate & Lyle Pearl
Antimicrobial Gypsum Board: ½″ Dense Armor Plus Mold & Humidity Resistant gypsum panel from Georgia Pacific
Joint Compound: Ready Mixed Sheetrock All Purpose Joint Compound from US Gypsum
Method:
Two Dynamic Sheet Former (DSF) handsheets were made according to the following experimental design:
TABLE 1
DSF Study for paper substrates for use
as antimicrobial wallboard tape
Design:
Liquid
Wet
Surface
DSF
Sizing
Alum
Strength
Sizing
A/M*
BDBW
I.D.
lb/T
lb/T
lb/T
(Starch)
Agent
Target gsm
A
0
20
12
N
N
131.5
B
0
20
12
N
Y
131.5
C
10
20
12
N
N
131.5
D
10
20
12
N
Y
131.5
E
0
20
12
Y
N
125.0
F
0
20
12
Y
Y
125.0
G
10
20
12
Y
N
125.0
H
10
20
12
Y
Y
125.0
Due to the size of the wet-press felt, all sheets were divided into thirds and then wet-pressed at a pressure of 40 psi before drying on a rotary drum-dryer.
All sheets were tested for the following physical properties prior to any surface sizing with starch: Basis Weight (TAPPI T-410), Caliper (TAPPI T-411), Gurley Porosity (TAPPI T-460), and HST with 10% formic acid and dye solution (TAPPI T-530).
Samples E-H were then run through a bench-top puddle size press using the Pearl Starch and dried on a drum-dryer. The pearl starch was cooked in two batches having solids measuring 16.7% and 16.3% yielding an approximate pick up of 110 #/Ton.
Sheets for samples E-H were tested again for the same physical properties as before. All sheets for samples A-H were manually sanded using a belt sander and 80 grit sand paper.
Samples B, D, F, and H were manually dipped in a bath of Intace B350 anti-michotic agent to yield an approximate pick up of 2 #/Ton. Then each sheet for those samples was dried on a drum-dryer.
Samples from each condition A-H were cut into 1″ wide tape strips. Then they were adhered to 3″×3″ squares of anti-microbial gypsum board using joint compound and allowed to air dry.
Prior to inoculation, 3 samples from each condition (A-H) were soaked in ½″ of sterile water for 1 hour. Each gypsum board square was placed upright on its edge so that the water comes ½ ″ up the side of the square that has the tape touching the edge as indicated in FIG. 4 .
Sample squares were placed on 150×25 mm agar plates and inoculated with 0.38 mL of inoculum containing Chaetomium globosum, Aspergillus terreus , and Aspergillus niger . The inoculum was spread along the bottom half of the sample square (as seen in FIG. 5 ), allowing a portion of the tape to remain uninoculated.
There was also a set of additional tape samples (A-H) that were not bonded to gypsum panels that corresponded to each gypsum board specimen that was tested. The tape was exposed to water in the same manner as the gypsum board samples, but for 2 minutes instead of 1 hour. They were then inoculated over their entire surface with 0.25 mL of the inoculum.
Growth observations for all samples were recorded at 7, 21, 33, and 62 days after the samples were inoculated. Photographs of a representative sample for each condition were taken on or near each observation date.
An amended*form of ASTM Method D2020-92 Standard Test Methods for Mildew (Fungus) Resistance of Paper and Paperboard was followed. The amendments included
1) The test substances were wallboard pieces (i.e. gypsum board square) measuring 3 inches by 3 inches (see above and in FIG. 4 ). 2) Prior to inoculation, each wallboard piece was exposed to a ½ inch of sterile water for 1 hour. The test substance pieces were placed on their edge upright so that the water comes ½ inch up the side of the piece that has the tape touching the edge (see FIG. 5 ). 3) After exposure to the water, the test substances pieces were placed on the 150×25 mm agar plates. 4) Each replicate was inoculated with 0.38 mL of the inoculums. The inoculums were spread along the bottom half of the wallboard piece, the bottom being the edge that was immersed. This will allowed a portion of the tape to remain uninoculated. 5) For each wallboard piece, there was a corresponding separate piece of tape. The tape was exposed to the water in the same manner as the wallboard for 2 minutes. The tape pieces were inoculated over their entire surface with 0.25 mL of the inoculums.
Results;
Summary (Observations Until Day 33)
A/M Treatment—Application hinders mold growth from day 7 to 33 in all but one sample (Sample F).
Starch Content—Mold growth differences in samples with and without starch in them were not noted until day 33. There is a visual difference on day 20: Samples with starch had noticeably more and larger spore clusters than samples without.
Sizing Content—Mold growth was noticeably smaller in spore size and cluster amounts on samples where sizing was present.
Growth with Increasing Time—For samples with mold growth, regardless of starch or sizing content, sporulation mostly began on the edges of the tape by the first observation day (7 days after inoculation). By the second observation day (21 days after inoculation), mold growth had spread across the surface of the tape.
Time-Specific Observations
Day 7 Observations
All samples that contain the a/m application show no growth—a/m agent has an effect in prohibiting growth of mold.
Most growth initiated at the tape edge for samples where slight growth was noted.
At this stage of growth sizing and starch content do not appear to have an effect on mold growth due to the fact that replicates where “heavy” growth was noted in the “soaked” portion of the sample had sizing in one and no sizing in the other.
Most samples did not have growth past the inoculation site.
Day 21 Observations
Growth began to occur in the non-inoculated region where water “wicked” up the drywall portion of the sample during the soaking portion of sample prep.
Sizing still does not seem to hinder mold growth at this stage since occurrences of “heavy” growth appeared on samples with and without sizing. The effects of the content of starch are still not seen at this point either because the “heavy” mold growth appeared on samples with and without starch in them.
All samples that contain the a/m application still show no growth with the exception of sample F (no starch, no sizing, with a/m). This particular sample is believed to be an outlier. Two replicates for this sample had mold growth on the dry portion of the non-inoculated drywall.
Growth is now seen on the surface of all samples that show growth, not just the edge of the tape.
Day 33 Observations
Still no growth on the samples with the a/m treatment.
Most reps have the same mold coverage as day 21 results.
Additional mold growth is noted along the edge of the inoculated portion of the tape on samples containing starch but no a/m treatment.—effect of added nutrients (aka starch) now visible.
Day 62 Observations—
A/M Treatment—all samples show no growth on the tape itself. Sample F (with starch, no sizing, with a/m) has very slight growth on the drywall above the inoculation point only for two of three reps. No other a/m treated samples have growth anywhere on them.
Starch Content—For those samples without starch, sporadic mold growth is noted above the inoculation point. Samples that contain starch have evenly spread growth above the inoculation point with slightly larger spores below the inoculation point.
Sizing Content—Samples without sizing show consistent growth above and below the inoculation point. Samples with sizing show growth mostly confined to the inoculation area.
As used throughout, ranges are used as a short hand for describing each and every value that is within the range, including all subranges therein.
Numerous modifications and variations on the present invention are possible in light of the above teachings. It is, therefore, to be understood that within the scope of the accompanying claims, the invention may be practiced otherwise than as specifically described herein.
All of the references, as well as their cited references, cited herein are hereby incorporated by reference with respect to relative portions related to the subject matter of the present invention and all of its embodiment | This invention relates to paper products and/or substrates suitable for being made into wallboard tape (also may be known as joint tape and/or drywall tape) and having improved reduction or inhibition in the growth of microbes, mold and/or fungus. The paper substrate is characterized by its excellent physical properties including cross direction (CD) tensile, machine (MD) tensile, internal bond, wet tensile, hygroexpansivity, curl, bonding properties, bonding of joint tape to joint compound, etc. The paper product of the invention contains a sizing agent and an antimicrobial compound as well as other optional components including without limitation a binder. The paper product of the invention may be produced by contacting the plurality of cellulose fibers with each of the sizing agent, antimicrobial compound, and optional components at any point in the papermaking process, converting process, and/or post-converting process. Finally, the invention relates to methods of using the paper substrate. | 3 |
This application is a continuation of and claims the benefit of U.S. application Ser. No. 08/970,221 filed Nov. 14, 1997 U.S. Pat. No. 6,429,481, the disclosure of which is incorporated herein by reference.
BACKGROUND OF THE INVENTION
The present invention relates to field effect transistors, in particular trench DMOS transistors, and methods of their manufacture.
Power field effect transistors, e.g., MOSFETs (metal oxide semiconductor field effect transistors), are well known in the semiconductor industry. One type of MOSFET is a DMOS (double diffused metal oxide semiconductor) transistor. DMOS transistors typically include a substrate on which an epitaxial layer is grown, a doped source junction, a doped heavy body, a doped well of the same (p or n) doping as the heavy body, and a gate electrode. In trenched DMOS transistors the gate electrode is a vertical trench. The heavy body is typically diffused deeper than the bottom of the trench, to minimize electric field at the bottom corners of the trench and thereby prevent avalanche breakdown from damaging the device. The trench is filled with conductive polysilicon, and the polysilicon is generally overetched, to assure that it is completely removed from the surface surrounding the trench. This overetching generally leaves a recess between the top of the polysilicon and the surface of the semiconductor substrate (i.e., the surface of the epitaxial layer). The depth of this recess must be carefully controlled so that it is shallower than the depth of the source junctions. If the recess is deeper than the source junctions the source may miss the gate, resulting in high on-state resistance, high threshold, and potentially a non-functional transistor.
The source and drain junctions can be doped with either p-type or n-type dopants; in either case, the body will be doped with the opposite dopant, e.g., for n-type source and drain the body will be p-type. DMOS transistors in which the source and drain are doped with p-type carriers are referred to as “p-channel”. In p-channel DMOS transistors a negative voltage applied to the transistor gate causes current flow from the source region, through a channel region of the body, an accumulation region of the epitaxial layer, and the substrate, to the drain region. Conversely, DMOS transistors, in which the source and drain are doped with n-type carriers, are referred to as “n-channel”. In n-channel DMOS transistors a positive voltage applied to the transistor gate causes current to flow from drain to source.
It is desirable that DMOS transistors have low source to drain resistance (Rds on ) when turned on and low parasitic capacitance. The transistor structure should also avoid “punchthrough”. Punchthrough occurs when, upon application of a high drain to source voltage, depletion into the body region extends to the source region, forming an undesirable conductive path through the body region when the transistor should be off. Finally, the transistor should have good “ruggedness”, i.e., a high activation current is needed to turn on the parasitic transistor that inherently exists in DMOS transistors.
Generally a large number of MOSFET cells are connected in parallel forming a single transistor. The cells may be arranged in a “closed cell” configuration, in which the trenches are laid out in a grid pattern and the cells are enclosed on all sides by trench walls. Alternatively, the cells may be arranged in an “open cell” configuration, in which the trenches are laid out in a “stripe” pattern and the cells are only enclosed on two sides by trench walls. Electric field termination techniques are used to terminate junctions (doped regions) at the periphery (edges) of the silicon die on which the transistors are formed. This tends to cause the breakdown voltage to be higher than it would otherwise be if controlled only by the features of the active transistor cells in the central portions of the die.
SUMMARY OF THE INVENTION
The present invention provides field effect transistors that have an open cell layout that provides good uniformity and high cell density and that is readily scalable. Preferred trenched DMOS transistors exhibit low Rds on , low parasitic capacitance, excellent reliability, resistance to avalanche breakdown degradation, and ruggedness. Preferred devices also include a field termination that enhances resistance to avalanche breakdown. The invention also features a method of making trench DMOS transistors.
In one aspect, the invention features a trenched field effect transistor that includes
(a) a semiconductor substrate, (b) a trench extending a predetermined depth into the semiconductor substrate, (c) a pair of doped source junctions, positioned on opposite sides of the trench, (d) a doped heavy body positioned adjacent each source junction on the opposite side of the source junction from the trench, the deepest portion of the heavy body extending less deeply into said semiconductor substrate than the predetermined depth of the trench, and (e) a doped well surrounding the heavy body beneath the heavy body.
Preferred embodiments include one or more of the following features. The doped well has a substantially flat bottom. The depth of the heavy body region relative to the depths of the well and the trench is selected so that the peak electric field, when voltage is applied to the transistor, will be spaced from the trench. The doped well has a depth less than the predetermined depth of the trench. The trench has rounded top and bottom corners. There is an abrupt junction at the interface between the heavy body and the well, to cause the peak electric field, when voltage is applied to the transistor, to occur in the area of the interface.
In another aspect, the invention features an array of transistor cells. The array includes (a) a semiconductor substrate, (b) a plurality of gate-forming trenches arranged substantially parallel to each other and extending in a first direction, the space between adjacent trenches defining a contact area, each trench extending a predetermined depth into said substrate, the predetermined depth being substantially the same for all of said gate-forming trenches; (c) surrounding each trench, a pair of doped source junctions, positioned on opposite sides of the trench and extending along the length of the trench, (d) positioned between each pair of gate-forming trenches, a doped heavy body positioned adjacent each source junction, the deepest portion of each said heavy body extending less deeply into said semiconductor substrate than said predetermined depth of said trenches, (e) a doped well surrounding each heavy body beneath the heavy body; and (f) p+ and n+ contacts disposed at the surface of the semiconductor substrate and arranged in alternation along the length of the contact area.
Preferred embodiments include one or more of the following features. The doped well has a substantially flat bottom. The depth of each heavy body region relative to the depths of the wells and the gate-forming trenches is selected so that the peak electric field, when voltage is applied to the transistor, will be spaced from the trench. The doped wells have a depth less than the predetermined depth of the trenches. The trenches have rounded top and bottom corners. There is an abrupt junction at the interface between each heavy body and the corresponding well, to cause the peak electric field, when voltage is applied to the transistor, to occur in the area of the interface. The array also includes a field termination structure surrounding the periphery of the array. The field termination structure includes a well having a depth greater than that of the gate-forming trenches. The field termination structure includes a termination trench extending continuously around the periphery of the array, more preferably a plurality of concentrically arranged termination trenches.
In yet another aspect, the invention features a semiconductor die that includes (a) a plurality of DMOS transistor cells arranged in an array on a semiconductor substrate, each DMOS transistor cell including a gate-forming trench, each of said gate-forming trenches having a predetermined depth, the depth of all of the gate-forming trenches being substantially the same; and (b) surrounding the periphery of the array, a field termination structure that extends into the semiconductor substrate to a depth that is deeper than said predetermined depth of said gate-forming trenches.
Preferred embodiments include one or more of the following features. The field termination structure includes a doped well. The field termination structure includes a termination trench. The field termination structure includes a plurality of concentrically arranged termination trenches. Each of the DMOS transistor cells further comprises a doped heavy body and the doped heavy body extends into the semiconductor substrate to a depth than is less than the predetermined depth of the gate-forming trenches.
The invention also features a method of making a heavy body structure for a trenched DMOS transistor including (a) providing a semiconductor substrate; (b) implanting into a region of the substrate a first dopant at a first energy and dosage; and (c) subsequently implanting into said region a second dopant at a second energy and dosage, said second energy and dosage being relatively less than said first energy and dosage.
Preferred embodiments include one or more of the following features. The first and second dopants both comprise boron. The first energy is from about 150 to 200 keV. The first dosage is from about 1E15 to 5E15 cm −2 . The second energy is from about 20 to 40 keV. The second dosage is from about 1E14 to 1E15 cm −2 .
Additionally, the invention features a method of making a source for a trenched DMOS transistor including (a) providing a semiconductor substrate; (b) implanting into a region of the substrate a first dopant at a first energy and dosage; and (c) subsequently implanting into the region a second dopant at a second energy and dosage, the second energy and dosage being relatively less than the first energy and dosage.
Preferred embodiments include one or more of the following features. The first dopant comprises arsenic and the second dopant comprises phosphorus. The first energy is from about 80 to 120 keV. The first dosage is from about 5E15 to 1E16 cm −2 . The second energy is from about 40 to 70 keV. The second dosage is from about 1E15 to 5E15 cm −2 . The resulting depth of the source is from about 0.4 to 0.8 μm the finished DMOS transistor.
In another aspect, the invention features a method of manufacturing a trenched field effect transistor. The method includes (a) forming a field termination junction around the perimeter of a semiconductor substrate, (b) forming an epitaxial layer on the semiconductor substrate, (c) patterning and etching a plurality of trenches into the epitaxial layer; (d) depositing polysilicon to fill the trenches, (e) doping the polysilicon with a dopant of a first type, (f) patterning the substrate and implanting a dopant of a second, opposite type to form a plurality of wells interposed between adjacent trenches, (g)
patterning the substrate and implanting a dopant of the second type to form a plurality of second dopant type contact areas and a plurality of heavy bodies positioned above the wells, each heavy body having an abrupt junction with the corresponding well, (h) patterning the substrate and implanting a dopant of the first type to provide source regions and first dopant type contact areas; and (i) applying a dielectric to the surface of the semiconductor substrate and patterning the dielectric to expose electrical contact areas.
Other features and advantages of the invention will be apparent from the following detailed description, and from the claims.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a highly enlarged, schematic perspective cross-sectional view showing a portion of a cell array including a plurality of DMOS transistors according to one aspect of the invention. The source metal layer and a portion of the dielectric layer have been omitted to show the underlying layers. FIGS. 1 a and 1 b are side cross-sectional views of a single line of transistors from the array of FIG. 1, taken along lines A—A and B—B, respectively. In FIGS. 1 a and 1 b the source metal and dielectric layers are shown.
FIG. 2 is a highly enlarged schematic side cross-sectional view of a semiconductor die showing a portion of the cell array and the field termination.
FIG. 3 is a flow diagram showing the photo mask sequence of a preferred process for forming a trench DMOS transistor of FIG. 1 .
FIGS. 4-4 k are schematic side cross-sectional views showing the individual steps of the process diagrammed in FIG. 3 . The figure numbers for the detailed views in FIGS. 4-4 k are shown parenthetically under the corresponding diagram boxes in FIG. 3 .
FIGS. 5, 5 a and 5 b are spreading resistance profile graphs, reflecting the dopant concentration distribution at different regions of the transistor.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
A cell array 10 , including a plurality of rows 12 of trenched DMOS transistors, is shown in FIG. 1 . Cell array 10 has an open cell configuration, i.e., trenches 14 run in only one direction, rather than forming a grid. Individual cells are formed by alternating n+ source contacts 16 and p+ contacts 18 in rows 20 that run parallel to and between trenches 14 . The configuration of the regions of each row that have an n+ source contact are shown in cross-section in FIG. 1 a , while the regions that have a p+ contact are shown in FIG. 1 b.
As shown in FIGS. 1 a and 1 b , each trenched DMOS transistor includes a doped n+ substrate (drain) layer 22 , a more lightly doped n− epitaxial layer 24 , and a gate electrode 28 . Gate electrode 28 comprises a conductive polysilicon that fills a trench 14 . A gate oxide 26 coats the walls of the trench and underlies the polysilicon. The top surface of the polysilicon is recessed from the surface 30 of the semiconductor substrate by a distance R (typically from about 0 to 0.4 μm). N+ doped source regions 32 a , 32 b are positioned one on each side of the trench 14 . A dielectric layer 35 covers the trench opening and the two source regions 32 a , 32 b . Extending between the source regions of adjacent cells is a p+ heavy body region 34 and, beneath it, a flat-bottomed p− well 36 . In the areas of the cell array which have a n+ contact 16 , a shallow n+ doped contact region extends between the n+ source regions. A source metal layer 38 covers the surface of the cell array.
The transistor shown in FIGS. 1 a and 1 b includes several features that enhance the ruggedness of the transistor and its resistance to avalanche breakdown degradation.
First, the depth of the p+ heavy body region 34 relative to the depths of the trench 14 and the flat bottom of the p− well is selected so that the peak electric field when voltage is applied to the transistor will be approximately halfway between adjacent trenches. The preferred relative depths of the p+ heavy body, the p− well and the trench are different for different device layouts. However, preferred relative depths can be readily determined empirically (by observing the location of peak electric field) or by finite element analysis.
Second, the bottom corners of the trench 14 are rounded (preferably, the top corners are also rounded; this feature is not shown). Corner rounding can be achieved using the process described in copending application U.S. Ser. No. 08/959,197, filed on Oct. 28, 1997. The rounded corners of the trench also tend to cause the peak electric field to be moved away from the trench corners and towards a central location between adjacent trenches.
Third, an abrupt junction at the interface between the p+ heavy body and the p− well causes the peak electric field to occur in that area of the interface. Avalanche multiplication initiates at the location of the peak electric field, thus steering hot carriers away from the sensitive gate oxide and channel regions. As a result, this structure improves reliability and avalanche ruggedness without sacrificing cell density as much as a deeper heavy body junction. This abrupt junction can be achieved by the double doping process that will be described below, or by other processes for forming abrupt junctions, many of which are known in the semiconductor field.
Lastly, referring to FIG. 2, the cell array is surrounded by a field termination junction 40 which increases the breakdown voltage of the device and draws avalanche current away from the cell array to the periphery of the die. Field termination junction 40 is a deep p+ well, preferably from about 1 to 3 μm deep at its deepest point, that is deeper than the p+ heavy body regions 34 in order to reduce the electric field caused by the junction curvature. A preferred process for making the above-described transistors is shown as a flow diagram in FIG. 3, and the individual steps are shown schematically in FIGS. 4-4 k . It is noted that some steps that are conventional or do not require illustration are described below but not shown in FIGS. 4-4 k . As indicated by the arrows in FIG. 3, and as will be discussed below, the order of the steps shown in FIGS. 4-4 k can be varied. Moreover, some of the steps shown in FIGS. 4-4 k are optional, as will be discussed.
A semiconductor substrate is initially provided. Preferably, the substrate is a N++ Si substrate, having a standard thickness, e.g., 500 μm, and a very low resistivity, e.g., 0.001 to 0.005 Ohm-cm. An epitaxial layer is deposited onto this substrate, as is well known, preferably to a thickness of from about 4 to 10 μm. Preferably the resistivity of the epitaxial layer is from about 0.1 to 3.0 Ohm-cm.
Next, the field termination junction 40 is formed by the steps shown in FIGS. 4-4 c . In FIG. 4, an oxide layer is formed on the surface of the epitaxial layer. Preferably, the thickness of the oxide is from about 5 to 10 kÅ. Next, as shown in FIG. 4 a , the oxide layer is patterned and etched to define a mask, and the p+ dopant is introduced to form the deep p+ well field termination. A suitable dopant is boron, implanted at an energy of from about 40 to 100 keV and a dose of 1E14 (1×10 14 ) to 1E16 cm −2 . As shown in FIG. 4 b , the p+ dopant is then driven further into the substrate, e.g., by diffusion, and a field oxide layer is formed over the p+ junction. Preferably the oxide thickness is from about 4 to 10 kÅ. Finally, the oxide (FIG. 4) over the active area of the substrate (the area where the cell array will be formed) is patterned and removed by any suitable etching process, leaving only the field oxide in suitable areas. This leaves the substrate ready for the following steps that will form the cell array.
It is noted that, as an alternative to steps 4 - 4 c , a suitable field termination structure can be formed using a ring-shaped trench which surrounds the periphery of the cell array and acts to lessen the electric field and increase the resistance to avalanche breakdown degradation. This trench field termination does not require a field oxide or deep p+ body junction to be effective. Consequently, it can be used to reduce the number of process steps. Using a trench ring (or multiple concentric trench rings) to form a field termination is described in, e.g., U.S. Pat. No. 5,430,324, the full disclosure of which is hereby incorporated herein by reference. Preferably, the trench would have substantially the same depth as the trenches in the cell array.
The cell array is formed by the steps shown in FIGS. 4 d - 4 k . First, a plurality of trenches are patterned and etched into the epitaxial layer of the substrate (FIG. 4 d ). Preferably, as noted above, the trenches are formed using the process U.S. Application No. Ser. 08/959,197, filed on Oct. 28, 1997, now U.S. Pat. No. 6,103,635, so that the upper and lower corners of each trench will be smoothly rounded. As shown in FIG. 1 and described above, the trenches are patterned to run in only one direction, defined as an open cell structure. After trench formation, a gate oxide layer is formed on the trench walls, as is well known in the semiconductor field. Preferably the gate oxide has a thickness of from about 100 to 800 Å.
Next, as shown in FIG. 4 e , polysilicon is deposited to fill the trench and cover the surface of the substrate, generally to a thickness of from about 1 to 2 μm depending on the trench width (shown by the dotted lines in FIG. 4 e ). This layer is then planarized by the nature of its thickness relative to the trench width, typically from about 2 to 5 kÅ (indicated by solid lines in FIG. 4 e ). The polysilicon is then doped to n-type, e.g., by conventional POCL 3 doping or by phosphorus implant. The backside of the wafer need not be stripped (as is conventionally done prior to doping the polysilicon to enhance defect gettering) because any further doping of the highly doped substrate would be unlikely to result in any enhancement in defect gettering.
The polysilicon is then patterned with a photoresist mask and etched to remove it from the trench areas, as shown in FIG. 4 f . A small recess between the top of the polysilicon in the trench and the substrate surface inherently results when the polysilicon is etched completely to remove all of the polysilicon from the substrate surface. The depth of this recess must be controlled so that it does not exceed the depth of the n+ source junction that will be formed in a later step. To reduce the need to carefully control this aspect of the process, a relatively deep n+ source junction is formed, as will be discussed below.
Then, as shown in FIG. 4 g , the p− well is formed by implanting the dopant, e.g., a boron implant at an energy of 30 to 100 keV and a dosage of 1E13 to 1E15, and driving it in to a depth of from about 1 to 3 μm using conventional drive in techniques.
The next two steps (p+ heavy body formation) can be performed either before formation of the n+ source junction, or afterwards, as indicated by the arrows in FIG. 3 . P+ heavy body formation and n+ source junction formation can be performed in either order because they are both resist-masked steps and because there is no diffusion step in between. This advantageously allows significant process flexibility. The p+ heavy body formation steps will be described below as being performed prior to source formation; it will be understood that n+ source formation could be performed first simply by changing the order of the steps discussed below.
First, a mask is formed over the areas that will not be doped to p+, as shown in FIG. 4 h . (It is noted that this masking step is not required if the p+ heavy body is formed later, after the dielectric layer has been applied and patterned for contact holes. (see FIG. 4 k , below) so that the dielectric itself provides a mask.) As discussed above, it is preferred that the junction at the interface between the p− well and the p+ heavy body be abrupt. To accomplish this, a double implant of dopant (e.g., boron) is performed. For example, a preferred double implant is a first boron implant at an energy of 150 to 200 keV and a dose of 1E15 to 5E15 cm −2 , and a second boron implant at an energy of 20 to 40 keV and a dose of 1E14 to 1E15 cm −2 . The high energy first implant brings the p+ heavy body as deep as possible into the substrate, so that it will not compensate the n+ source junction to be introduced later. The second, lower energy/lower dose implant extends the p+ heavy body from the deep region formed during the first implant up to the substrate surface to provide the p+ contact 18 . The resulting p+ heavy body junction is preferably about 0.4 to 1 μm deep at this stage of the process (final junction depth after drive-in is preferably about 0.5 to 1.5 μm deep), and includes a region of high dopant concentration near the interface with the p-well, and a region of relatively low dopant concentration at the contact surface of the p+ heavy body. A preferred concentration distribution is shown in FIG. 5 .
It will be appreciated by those skilled in the art that the abrupt junction can be formed in many other ways, e.g., by diffused dopants, by using a continuous dopant source at the surface or by using atoms that diffuse slowly.
After the formation of the p+ heavy body, a conventional resist strip process is performed to remove the mask, and a new mask is patterned to prepare the substrate for the formation of the n+ source junction. This mask is a n+ blocking mask and is patterned to cover the areas of the substrate surface which are to provide p+ contacts 18 (FIGS. 1 and 1 b ), as shown in FIG. 4 i . This results in the formation of alternating p+ and n+ contacts after n-type doping (see lines A—A and B—B and cross-sectional views A—A and B—B in FIG. 4I, which correspond to FIGS. 1 a and 1 b ).
The n+ source regions and n+ contact are then formed using a double implant. For example, a preferred double implant process is a first implant of arsenic at an energy of 80 to 120 keV and a dose of 5E15 to 1E16 cm −2 followed by a second implant of phosphorus at an energy of 40 to 70 keV and a dose of 1E15 to 5E15 cm −2 The phosphorus implant forms a relatively deep n+ source junction, which allows more process flexibility in the depth of the polysilicon recess, as discussed above. Phosphorus ions will penetrate deeper into the substrate during implant and also during later diffusion steps. Advantageously, the n+ source regions will have a depth of about 0.4 to 0.8 μm after diffusion. The arsenic implant extends the n+ source to the substrate surface, and also forms the n+ contacts 16 (see FIGS. 1 and 1 a ) by compensating (converting) the p-type surface of the p+ heavy body to n-type in the desired contact area. The preferred sheet resistance profiles for the n+ source along the edge of the trench, and the n+ contact are shown in FIGS. 5 a and 5 b , respectively.
Thus, the alternating p+ and n+ contacts 18 , 16 , shown in FIG. 1 are formed by patterning the substrate with appropriate masks and doping with the first p+ implant and the second n+ implant, respectively, as described above. This manner of forming the alternating contacts advantageously allows an open cell array having a smaller cell pitch than is typical for such arrays and thus a higher cell density and lower Rds on .
Next, a conventional n+ drive is performed to activate the dopants. A short cycle is used, preferably 10 min at 900° C., so that activation occurs without excessive diffusion.
A dielectric material, e.g., borophosphate silicate glass (BPSG), is then deposited over the entire substrate surface and flowed in a conventional manner (FIG. 4 j ), after which the dielectric is patterned and etched (FIG. 4 k ) to define electrical contact openings over the n+ and p+ contacts 16 , 18 .
As noted above, the p+ heavy body implant steps can be performed at this point, if desired (rather than prior to n+ source formation), eliminating the need for a mask and thus reducing cost and process time.
Next, the dielectric is reflowed in an inert gas, e.g., a nitrogen purge. If the p+ body has been implanted immediately prior, this step is required to activate the p+ dopant. If the p+ body was implanted earlier, prior to the n+ drive, this step can be omitted if the dielectric surface is sufficiently smooth-edged around the contact openings.
The cell array is then completed by conventional metalization, passivation deposition and alloy steps, as is well know in the semiconductor field.
Other embodiments are within the claims. For example, while the description above is of an n-channel transistor, the processes of the invention could also be used to form a p-channel transistor. To accomplish this, “p” and “n” would simply be reversed in the above description, i.e., where “p” doping is specified above the region would be “n” doped instead, and vice versa. | A trenched field effect transistor is provided that includes (a) a semiconductor substrate, (b) a trench extending a predetermined depth into the semiconductor substrate, (c) a pair of doped source junctions, positioned on opposite sides of the trench, (d) a doped heavy body positioned adjacent each source junction on the opposite side of the source junction from the trench, the deepest portion of the heavy body extending less deeply into said semiconductor substrate than the predetermined depth of the trench, and (e) a doped well surrounding the heavy body beneath the heavy body. | 7 |
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a continuation of my co-pending application Ser. No. 12/150,826 filed on Apr. 30, 2008, entitled “Underwater Trenching Device” the full disclosures of which are incorporated by reference herein and priority of which is hereby claimed.
BACKGROUND OF THE INVENTION
[0002] The present invention relates to an underwater trenching system, and more particularly, to a trench making equipment that enlarges an underwater trench for burying a pipeline.
[0003] Many oil and gas production sites require installation of miles of pipelines for delivery of the produced material to a refinery or other destination. Often times, the pipelines are laid underwater, especially in shallow coastal waters. The pipes are usually buried at the bottom of a waterway, such as a river, marsh, or sea. In some locations, the pipes are simply laid along the bottom of a waterway and left exposed, to be buried by the action of the currents. In other uses, a trenching tool, such as a water jet, a cutter head, or a scoop, or clam shell digger digs a trench around the pipe, which then settles into the trench.
[0004] The bottom sediment eventually settles around the pipe although a large portion of it is carried to other areas of the waterway. The time when the sediment remain in suspension varies although it is known to have a potential for creating serious environmental damage to plants, animals, marine life, and the water. Over time, the sediment has a tendency to shift the pipeline, which causes it to rise from the bottom or from the trench. Current governmental regulations prohibit disturbing the waterway bottom for the second time, such that digging out the original trench for adjusting position of the pipeline is not a viable option. As a consequence, the only viable alternative is to excavate the side of the trench near the bottom and cause the pipeline to drop into the new indentation in the soil.
[0005] In short, all currently known equipment and methods for underwater trenching create large clouds of silt and debris that remain in suspension for a long time and seriously disrupt the ecology of the waterway. Reforming the trench by additional excavation of the bottom is not allowed.
[0006] There exists therefore a need for an underwater trenching system that avoids bottom trenching, while achieving the goal of lowering the pipeline into a trench without excavating the bottom of the trench.
SUMMARY OF THE INVENTION
[0007] It is therefore an object of the present invention to provide an underwater trenching system that is capable of evacuating sediment from a side of the trench without substantially disturbing the soil.
[0008] It is another object of the invention to provide an underwater trenching system that allows the pipe to settle back into the trench.
[0009] It is a further object of the present invention to reduce the time and cost of trenching by omitting the necessity to employ underwater divers.
[0010] These and other objects of the invention are achieved through a provision of an underwater trenching apparatus for repairing a trench formed in a bed of a waterway, within which a pipeline is located. The trenching apparatus comprises an elongated boom assembly having a proximate end configured for hingedly securing to a side of a floating vessel, such as a barge. A trenching unit is secured to a distal end of the boom assembly and moves between an above-water position and an underwater position with the help of a lifting means positioned on the deck of the barge, such for instance a lifting crane, a cable of which is detachably secured to the boom assembly.
[0011] The trenching unit comprises a pair of spaced-apart opposing sparge assemblies that deliver water and air under pressure to the trench where the pipeline is located. The water and air disturb the underwater formation and move the disturbed sediment or loose formation away from the pipeline in the trench. An elongated conduit admits the sediment through a bottom inlet opening and discharges the sediment through an upper outlet opening. An airlift unit mounted inside the tubular member is connected to an above-water air supply. The airlift unit creates turbulence inside the tubular member, causing sucking of the sediment into the tubular member and lifting the sediment and water toward the discharge opening.
BRIEF DESCRIPTION OF THE DRAWINGS
[0012] Reference will now be made to the drawings, wherein like parts are designated by like numerals, and wherein
[0013] FIG. 1 is a schematic view illustrating the underwater trenching apparatus of the instant invention in operation.
[0014] FIG. 2 illustrates the underwater trenching apparatus of the instant invention in transit or storage position.
[0015] FIG. 3 is a detail view showing the trenching unit connected to a single manifold.
[0016] FIG. 4 is a detail view showing the trenching unit with its pair of sparge assemblies.
[0017] FIG. 5 is detail, partially cut-away view showing one of the sparge assemblies and the airlift insert.
[0018] FIG. 6 is a detail view showing the airlift assembly mounted in the inlet portion of the tubular conduit.
[0019] FIG. 7 is detail view of the bottom of the sparge assembly illustrating the direction of intake flow entering the inlet portion of the tubular conduit.
[0020] FIG. 8 is a detail view of the nozzle of the sparge conduit.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0021] Turning now to the drawings in more detail, the system of the present invention is designated by numeral 10 . The system 10 comprises an elongated boom assembly 12 , a proximate end 14 of which is secured to a barge 16 or other suitable vessel. Conventional trenching equipment is usually centered on the barge. The system 10 , in contrast, is positioned on a side of the barge, with the boom assembly 12 secured to the starboard 20 of the barge 16 . Of course, the boom assembly 12 may be also secured to the port of the barge hull, depending on the location of the pipeline in the waterway. In FIG. 1 , the trenching system 10 is mounted on the barge 16 that moves in the direction of arrow 17 .
[0022] The proximate end 14 boom assembly 12 is hinged to a hinge plate 18 , which can be formed from a length of an I-beam, attached to the starboard 20 . The hinge plate 18 extends substantially horizontally, transversely to the starboard 20 and suspends the boom assembly 12 off the side of the barge 16 . The boom assembly 12 can move up and down in relation to the hinge plate 18 . A support bracket 22 supports the hinge plate 18 from below and absorbs some of the vertical and horizontal forces applied to the hinge plate 18 when the boom assembly 12 moves between a transport position shown in FIG. 2 to an operating position shown in FIG. 1 . A second reinforcing bracket 24 may be secured to the hinge plate 18 to further reinforce the position of the hinge plate 18 on the side of the barge 16 .
[0023] A distal end 26 of the boom assembly 12 is selectively secured to a lifting means 30 , which can be a deck crane, positioned on the deck 32 of the barge 16 . A lifting cable 34 detachably secures the boom assembly 12 to the lifting crane 30 to raise and lower the boom assembly 12 . The distal end 26 of the boom assembly 12 carries a trenching unit 40 that is lowered below the waterline 42 to reach the mud line 46 .
[0024] The boom assembly 12 comprises a pair of elongated beams 48 , 50 which are spaced from each other and are retained in a substantially parallel relationship by a plurality of transverse braces 54 and diagonal braces 56 . A mesh walkway 60 is secured between the beams 48 , 50 , allowing operators to access the trenching unit 40 and to measure the depth, at which the pipeline 62 extends below the mud line 46 . The depth measuring can be conducted using conventional devices that are well known in the industry and are not part of the instant invention.
[0025] Mounted on the deck 32 of the barge 16 is water and air supply units that deliver water under pressure and pressurized air to the trenching unit 40 . As can be seen in FIG. 3 , an air compressor 64 is positioned on the deck 32 and is connected to the trenching unit 40 by air supply conduits 68 , 69 . Water to the trenching unit 40 is supplied by a pair of jet pumps 70 , 72 that deliver water to the trenching unit 40 via water conduits 74 , 76 , respectively. The jet pumps 70 , 72 can produce 300 p.s.i. of pressure to the trenching unit 40 . The jet pumps are self-contained with fuel tanks, powered generator and an air compressor.
[0026] The trenching unit 40 comprises a pair of sparge units 80 , 82 that are connected to a single manifold 84 that supplies water under pressure through manifold connectors 86 , 88 , 90 , and 92 . Only two manifold connectors are active at a particular time during operation of the trenching unit 40 . Depending on the diameter of the pipeline 46 and the width of the desired trench, the trenching unit can be connected, through the manifold connectors to either two adjacent manifold connectors or to a pair of further spaced-apart manifold connectors. In the example illustrated in FIG. 3 , manifold connector 88 and 92 are used to supplying the pressurized water to the sparge units 80 , 82 .
[0027] The sparge units 80 and 82 are mirror images of each other. Each of the sparge units comprises a tubular conduit 94 that has a first inlet portion 96 , 98 , respectively, and a second discharge portion 102 , 104 , respectively. The discharge portions 102 , 104 are oriented at an angle to longitudinal axes of the first inlet portions 96 , 98 . The outlet openings of the second discharge portions 102 , 104 are oriented in opposite directions so that effluent is discharged away from the pipeline 46 .
[0028] The air supply conduit 68 is secured to the side of the first inlet portion 98 for delivering pressurized air to the interior of the first inlet portion 96 . Mounted inside the first inlet portion is an airlift insert 106 that has exterior dimensions slightly smaller than the interior of the first inlet portion conduit 98 . The insert 106 is secured inside the conduit defined by the first inlet portion and has a flared inlet opening 108 .
[0029] A plurality of openings 110 is formed in the walls of the insert 106 allowing air delivered through the air conduit 68 to enter the interior of the insert 106 and create turbulence inside the insert 106 . The turbulent flow carries the sediment, as will be explained in more detail hereinafter, toward the second discharge portion 102 and ultimately—to the discharge opening 112 of the second discharge portion 102 . As shown in FIG. 5 , the air supply conduit 68 is connected to the interior of the first inlet portion 98 at a level where the openings 110 in the insert 106 are located.
[0030] The openings 110 are preferably formed at an angle to the longitudinal axis of the insert 106 , as shown in FIG. 5 . The inclined openings 110 , which can be inclined at about 45 degrees in relation to the longitudinal axis, force the air upward into the first inlet portion 98 and create a turbulent flow therein. The flared bottom of the insert 106 and a reduced size of the remainder of the insert body 106 also facilitate the creation of a sucking force by creating a venturi effect and drop in pressure as the flow moves through the tubular portions 96 , 102 ( 98 , 104 ).
[0031] Each sparge unit 80 , 82 is provided with a sparge conduit 120 , 122 , respectively. The sparge conduits 120 , 122 are connected to the manifold 84 through manifold connector flanges 124 , 126 . Each sparge conduit 120 , 122 is provided with a plurality of discharge nozzles 128 , 130 that jet pressurized water/air mixture into the waterway bed 140 in the area adjacent the pipeline 46 . The nozzles 128 , 130 are detachably mounted in the corresponding openings formed in the wall of the sparge conduits 120 , 122 .
[0032] Each nozzle has exterior threads 131 that allow the nozzle to be threaded into the opening in the wall of the sparge conduit. An inlet opening 132 of the nozzle 128 (or 130 ) has a generally conical configuration, as can be seen in more detail in FIG. 8 . An outlet opening 134 has a diameter smaller than the diameter of the inlet opening 132 , such that the velocity of the fluid exiting the nozzle 128 ( 130 ) is increased causing a jetting effect. The water and air exiting the outlet opening 134 blast away sediment from the bottom of the waterway enlarging the trench 142 surrounding the pipeline 46 .
[0033] The disturbed sediment is sucked into the bottom opening 146 of the first inlet portion 98 and moves through the insert 106 under the force of the flow created by the incoming air flow. Some of the water moving through the sparge conduit 120 is diverted to the first inlet portion 98 below the airlift insert 106 by a pair of water hoses, or pipes 148 , 150 to facilitate movement of the sediment through the trenching unit 40 . The sediment can be discharged to the waterway bed 140 above the mud line 46 or, if the trench is shallow—even to the banks of the waterway.
[0034] To ensure alignment of the trenching unit 40 with the pipeline 46 , the trenching unit 40 is provided with a guiding means, which comprises a plurality of rotating guiding rollers. A transverse roller 152 is secured between the sparge conduits 120 , 122 at a position downstream from the inlets openings of the sparge conduits 12 , 122 . In the embodiment shown in FIG. 4 , the transverse roller 152 is positioned at an approximate level above an anticipated depth of the pipeline 46 .
[0035] A pair of vertical guiding rollers 154 , 156 is positioned in a general vertical alignment with the first inlet portion 96 , and a similar pair of vertical guiding rollers 158 , 160 is positioned in a general vertical alignment with the first inlet portion 98 . The rollers 154 , 156 , 158 , and 160 prevent the trenching unit 40 from significantly deviating from the dimensions created by the sides of the trench, where the pipeline 46 is located. The distance between the rollers 154 , 156 and 158 , 160 is selected to conserve energy and enlarge the trench 142 only as necessary for the pipeline 46 .
[0036] The barge 16 can be propelled by a tug boat 170 shown in phantom line in FIG. 1 , or by other suitable means that allow the trenching unit 40 to move along the pipeline and enlarge or form a trench. If desired, the roller guides 154 , 156 , 158 and 160 can be distanced to straddle the pipe 46 and keep the trenching unit 40 aligned with the pipeline 46 . The rollers are also important in protecting the conduits from contact with rocky trench walls.
[0037] If desired the nozzles 128 , 130 can be strategically spaced along the length of the inlet portions such that the majority of the nozzles are located closer to the bottom of the trench, while fewer nozzles are located in an area that would be approximately above the pipeline 46 . The depth of the pipeline 46 embedment can be measured prior to lowering the trenching unit 40 into water.
[0038] The barge 16 is propelled along the waterway at a desired speed, allowing the sparge units 80 , 82 to disturb underwater sediment and for the airlift force to lift the disturbed sediment away from the trench. The actual speed of travel depends on the condition of the waterway bed. Naturally, slower speed will be necessary where there exists clay bottom than where the bed is sandy. It is envisioned that a land vehicle may be employed for transporting the trenching apparatus of the present invention. Depending on several factors, such as the width of the waterway, the location of the pipeline and the depth, at which the pipeline is buried the land vehicle with the boom assembly mounted thereon may be employed.
[0039] Many changes and modifications can be made in the design of the present invention without departing from the spirit thereof. I therefore pray that my rights to the present invention be limited only by the scope of the appended claims. | An underwater trenching system is mountable on a side of a barge to be propelled by the barge along a waterway, the bed of which contains a trench with a laid pipeline. To remove the excess sediment from the trench the trenching unit delivers pressurized water and air to the trench. A sparge assembly with jet nozzles directs jets of water, breaking up the formation that has built up around the pipeline. The airlift assembly creates a turbulent flow to lift the disturbed sediment and remove it from the created trench. | 4 |
FIELD
[0001] The present invention relates to modified ionomers and a process for production thereof.
BACKGROUND
[0002] Poly(isobutylene-co-isoprene) or IIR, is a synthetic elastomer commonly known as butyl rubber (or Butyl polymer) which has been prepared since the 1940's through the random cationic copolymerization of isobutylene with small amounts of isoprene (usually not more than 2.5 mol %). As a result of its molecular structure, IIR possesses superior air impermeability, a high loss modulus, oxidative stability and extended fatigue resistance.
[0003] Halogenation of butyl rubber produces reactive allylic halide functionality within the elastomer. Conventional butyl rubber halogenation processes are described in, for example, Ullmann's Encyclopedia of Industrial Chemistry (Fifth, Completely Revised Edition, Volume A231 Editors Elvers, et al.) and/or “Rubber Technology” (Third Edition) by Maurice Morton, Chapter 10 (Van Nostrand Reinhold Company© 1987), particularly pp. 297-300.
[0004] The development of halogenated butyl rubber (halobutyl) has greatly extended the usefulness of butyl by providing much higher curing rates and enabling co-vulcanization with general purpose rubbers such as natural rubber and styrene-butadiene rubber (SBR). Butyl rubber and halobutyl rubber are high value polymers, as their unique combination of properties (excellent impermeability, good flex, good weatherability, and co-vulcanization with high unsaturation rubbers in the case of halobutyl) make them preferred materials for various applications, such as in making tire inner tubes and tire inner liners.
[0005] The presence of allylic halide functionalities allows for nucleophilic alkylation reactions. It has been shown that treatment of brominated butyl rubber (BIIR) with nitrogen and/or phosphorus based nucleophiles, in the solid state, leads to the generation of IIR-based ionomers with interesting physical and chemical properties (see: Parent J. S., Liskova A., Whitney R. A, Resendes R. Journal of Polymer Science, Part A: Polymer Chemistry 43, 5671-5679, 2005; Parent J. S., Liskova A., Resendes R. Polymer 45, 8091-8096, 2004; Parent J. S., Penciu A., Guillen-Castellanos S. A., Liskova A., Whitney R. A. Macromolecules 37, 7477-7483, 2004). The ionomer functionality is generated from the reaction of a nitrogen or phosphorus based nucleophile and the allylic halide sites in the halogenated butyl rubber to produce an ammonium or phosphonium ionic group respectively.
[0006] The formation of phosphonium butyl ionomers have been disclosed previously. U.S. Pat. No. 7,662,480 describes the synthesis of phosphonium butyl ionomer by mixing BIIR with 3 molar equivalents based on allylic bromide content BIIR in an internal mixer at 100° C. for 1 hour. This resulted in the complete conversion of all the allylic bromide to the phosphonium ionomer.
[0007] Similarly, WO 2012/083419 describes butyl phosphonium ionomers prepared by addition of BIIR to a Brabender internal mixer at 130° C. and 60 rpm. The rubber mixed for a short period before the addition of the TPP (1.2 molar equivalents) and further mixed for 7 to 10 minutes. This process resulted in 65% conversion of the allylic bromide to the phosphonium ionomer.
[0008] United States Patent Publication US 2012/0059074 describes butyl ionomer formation by premixing BIIR and TPP (1.2 molar equivalents based on allylic bromide) on a room temperature mill followed by heating the mixture on the mill 100° C. for 1 hour resulting in the complete conversion of all the allylic bromide to the phosphonium ionomer.
[0009] United States Patent Publication US 2013/0217833 describes an energy efficient, environmentally favourable process for preparing water and solvent-free rubber ionomers, however, no resulting polymer properties are described by feeding a free-flowing concentrated fluid containing brominated rubber and at least one volatile compound as well as a nitrogen or phosphorous containing nucleophile into an extruder that has a degassing, accumulating and outlet section wherein the brominated rubber is partially reacted to form a rubber ionomer.
[0010] In the above references, not all of the nucleophile mixed with the halogenated copolymer is reacted to form the ionomer. The unreacted nucleophile will remain in the polymer as residual nucleophile. The residual nucleophile may further react with oxidizing agents to further form an oxidative derivative of the nucleophile. For some rubber applications, butyl rubber must be compounded and vulcanized to yield useful and durable products. Excess triphenylphosphine (TPP) and triphenylphosphine oxide (TPP=O), however, may negatively affect vulcanization of the ionomer compound and the resulting physical and dynamic properties. The TPP reacts with sulfur to form the corresponding triphenylphosphine sulfide resulting in less available sulfur for vulcanization. Further, TPP reacts with peroxide to form TPP=O, resulting in less available peroxide for vulcanization. In addition, for high purity applications, extractables containing the excess residual nucleophile would not be suitable for such applications.
[0011] The phosphonium butyl ionomer polymers of the prior art have a distinct yellow to brownish colouration due to various undesired side and decomposition reactions. This feature is technically unacceptable to consumer in particular for applications such as coatings and films.
[0012] There remains a need for a process for the production of ionomers with high conversion and one or more of low residual nucleophile and corresponding derivatives, and low yellowness index.
SUMMARY
[0013] There is provided a process for producing an ionomer comprising at least the steps of
(a) admixing in a mixer a halogenated copolymer with at least one nitrogen and/or phosphorous based nucleophile in an amount of from 0.01 to 1.1 molar equivalents based on the total allylic halide content of the halogenated copolymer, at a temperature in a range of 40 to 200° C. for 0.5 to 30 minutes; and (b) extruding the mixture from step (a) at a temperature in a range of 50 to 200° C. for 0.5 to 30 minutes and/or milling the mixture from step (a) in a multi roll mill, preferably a two roll mill for about 0.5-90 minutes at a temperature in a range of 50-200° C.
[0017] The resulting ionomer typically contains an amount of residual nucleophile or oxidative derivative thereof between 0-50% based on the original amount of nucleophile added, and a final multiolefin content between 50-100% based on the multiolefin content of the halogenated copolymer.
[0018] There is further provided a ionomer produced by reacting a nucleophile with a halogenated copolymer having a total allylic halide content of about 0.05 to 2.0 mol % based on the total allylic halide content of the halogenated copolymer, comprising an amount of residual nucleophile or oxidative derivative thereof in a range of 0 to 50% based on the amount of nucleophile reacted to form the ionomer.
[0019] There is further provided an elastomeric compound comprising a cured blend of the ionomer of the present invention and at least one elastomer co-curable with the ionomer.
[0020] There is further provided an article of manufacture comprising the elastomeric compound of the present invention.
[0021] The process produces ionomer with high conversion and one or more of low residual nucleophile and corresponding derivatives, low yellowness index and low molecular weight breakdown.
[0022] Further features will be described or will become apparent in the course of the following detailed description.
DETAILED DESCRIPTION
[0023] The present invention is directed to ionomers and process of making said ionomers. As used herein, the terms “ionomeric isoolefin based copolymer”, “ionomeric copolymer”, “ionomer” may be used interchangeably.
[0024] According to the process of the present invention ionomers may be obtained by reacting a halogenated copolymer with a nucleophile in a mixer followed by feeding the mixture into an extruder or a multi roll mill.
[0025] The copolymers comprise at least one isoolefin monomer and at least one multiolefin monomer and/or β-pinene, and optionally one or more further copolymerizable monomers. As used herein, “isoolefin copolymers”, “isoolefin-multiolefin copolymers” and “copolymers” are used interchangeably.
[0026] Suitable isoolefin monomers include hydrocarbon monomers having 4 to 16 carbon atoms. In one embodiment, isoolefins have from 4-7 carbon atoms. Examples of suitable isoolefins include isobutene (isobutylene), 2-methyl-1-butene, 3-methyl-1-butene, 2-methyl-2-butene, 4-methyl-1-pentene, 4-methyl-1-pentene and mixtures thereof. A preferred isoolefin monomer is isobutene (isobutylene).
[0027] Multiolefin monomers copolymerizable with the isoolefin monomers may include dienes, for example conjugated dienes. Particular examples of multiolefin monomers include those having in the range of from 4-14 carbon atoms. Examples of suitable multiolefin monomers include isoprene, butadiene, 2-methylbutadiene, 2,4-dimethylbutadiene, piperyline, 3-methyl-1,3-pentadiene, 2,4-hexadiene, 2-neopentylbutadiene, 2-methyl-1,5-hexadiene, 2,5-dimethyl-2,4-hexadiene, 2-methyl-1,4-pentadiene, 4-butyl-1,3-pentadiene, 2,3-dimethyl-1,3-pentadiene, 2,3-dibutyl-1,3-pentadiene, 2-ethyl-1,3-pentadiene, 2-ethyl-1,3-butadiene, 2-methyl-1,6-heptadiene, cyclopentadiene, methylcyclopentadiene, cyclohexadiene, 1-vinyl-cyclohexadiene and mixtures thereof. A particularly preferred conjugated diene is isoprene. β-pinene may also be used instead of or in addition to the multiolefin monomer. Herein multiolefin/β-pinene monomers refers to the presence or use of one or more multiolefin monomers and/or β-pinene monomer.
[0028] The copolymer may optionally include one or more additional copolymerizable monomers along with the isoolefin and multiolefin/β-pinene monomers. Additional copolymerizable monomers include monomers copolymerizable with the isoolefin and/or multiolefin/β-pinene monomers. Suitable copolymerizable monomers include, for example, styrenic monomers, such as alkyl-substituted vinyl aromatic co-monomers, including but not limited to a C 1 -C 4 alkyl substituted styrene. Specific examples of copolymerizable monomers include, for example, α-methyl styrene, ρ-methyl styrene, chlorostyrene, cyclopentadiene and methylcyclopentadiene. In one embodiment, the butyl rubber polymer may comprise random copolymers of isobutylene, isoprene and ρ-methyl stryene.
[0029] The copolymers are formed from a mixture of monomers described herein. In one embodiment, the monomer mixture comprises from about 80% to about 99% by weight of an isoolefin monomer and from about 1% to 20% by weight of a multiolefin/β-pinene monomer. In another embodiment, the monomer mixture comprises from about 85% to about 99% by weight of an isoolefin monomer and from about 1% to 15% by weight of a multiolefin/β-pinene monomer. In certain embodiments, three monomers may be employed. In these embodiments, the monomer mixture may comprise about 80% to about 99% by weight of isoolefin monomer, from about 0.5% to about 5% by weight of a multiolefin/β-pinene monomer, and from about 0.5% to about 15% by weight a third monomer copolymerizable with the isoolefin and/or multiolefin/β-pinene monomers. In one embodiment, the monomer mixture comprises from about 68% to about 99% by weight of an isoolefin monomer, from about 0.5% to about 7% by weight of a multiolefin/β-pinene monomer and from about 0.5% to about 25% by weight of a third monomer copolymerizable with the isoolefin and/or multiolefin/β-pinene monomers.
[0030] The copolymer may be prepared by any suitable method, of which several are known in the art. For example, the polymerization of monomers may be performed in the presence of AlCl 3 and a proton source and/or cationogen capable of initiating the polymerization process. A proton source includes any compound that will produce a proton when added to AlCl 3 or a composition containing AlCl 3 . Protons may be generated from the reaction of AlCl 3 with proton sources such as water, alcohol or phenol to produce the proton and the corresponding by-product. Such reaction may be preferred in the event that the reaction of the proton source is faster with the protonated additive as compared with its reaction with the monomers. Other proton generating reactants include thiols, carboxylic acids, and the like. The most preferred proton source is water. The preferred ratio of AlCl 3 to water is between 5:1 to 100:1 by weight. It may be advantageous to further introduce AlCl 3 derivable catalyst systems, diethylaluminium chloride, ethylaluminium chloride, titanium tetrachloride, stannous tetrachloride, boron trifluoride, boron trichloride, or methylalumoxane. Inert solvents or diluents known to the person skilled in the art for butyl polymerization may be considered as the solvents or diluents (reaction medium). These include alkanes, chloroalkanes, cycloalkanes or aromatics, which are frequently also mono- or polysubstituted with halogens. Hexane/chloroalkane mixtures, methyl chloride, dichloromethane or the mixtures thereof may be preferred. Chloroalkanes are preferably used. The monomers are generally polymerized cationically, preferably at temperatures in the range from −120° C. to +20° C., preferably in the range from −100° C. to −20° C., and pressures in the range from 0.1 to 4 bar.
[0031] The copolymer may also be produced via a solution process as outlined in International Patent Publication WO 2011/089083 and references therein. A C6 solvent is a particularly preferred choice for use in a solution process. C6 solvents suitable for use in the present invention preferably have a boiling point of between 50° C. and 69° C. Examples of preferred C6 solvents include n-hexane or hexane isomers, such as 2-methyl pentane or 3-methyl pentane, or mixtures of n-hexane and such isomers as well as cyclohexane.
[0032] The copolymer may comprise at least 0.5 mol % repeating units derived from the multiolefin/β-pinene monomers. In some embodiments, the repeating units derived from the multiolefin/β-pinene monomers may be present in the copolymerin an amount of at least 0.75 mol %, or at least 1.0 mol %, or at least 1.5 mol %, or at least 2.0 mol %, or at least 2.5 mol %, or at least 3.0 mol %, or at least 3.5 mol %, or at least 4.0 mol %, or at least 5.0 mol %, or at least 6.0 mol %, or at least 7.0 mol %. In one embodiment, the butyl rubber polymer may comprise from 0.5 to 2.2 mol % of the multiolefin/β-pinene monomers. In another embodiment, the copolymer may comprise higher multiolefin/β-pinene monomer content, e.g. 3.0 mol % or greater. The preparation of suitable high multiolefin/β-pinene butyl rubber polymers is described in Canadian Patent Application 2,418,884.
[0033] In one embodiment, the halogenated copolymer may be obtained by first preparing a copolymer from a monomer mixture comprising one or more isoolefins, and one or more multiolefins and/or β-pinene in particular as described above, followed by subjecting the resulting copolymer to a halogenation process to form the halogenated copolymer. Halogenation can be performed according to the process known by those skilled in the art, for example, the procedures described in Rubber Technology, 3rd Ed., Edited by Maurice Morton, Kluwer Academic Publishers, pp. 297-300 and further documents cited therein. Halogenation may involve bromination and/or chlorination. Brominated copolymer may be of particular note. For example, a brominated butyl rubber comprising isobutylene and less than 2.2 mole percent isoprene is commercially available from LANXESS Deutschland GmbH and sold under the name BB2030™.
[0034] In the halogenated copolymer one or more of the repeating units derived from the multiolefin monomers comprise an allylic halogen moiety. During halogenation, some or all of the multiolefin and/or β-pinene content of the copolymer is converted to units comprising allylic halides. These allylic halide sites in the halogenated copolymer result in repeating units derived from the multiolefin monomers and/or β-pinene originally present in the non-halogenated copolymer. The total allylic halide content of the halogenated copolymer cannot exceed the starting multiolefin and/or β-pinene content of the parent copolymer, however residual allylic halides and/or residual multiolefins may be present. The allylic halide sites allow for reacting with and attaching one or more nucleophiles to the halogenated copolymer. The halogenated copolymer may have a total allylic halide content from 0.05 to 2.0 mol %. The halogenated copolymer may also contain residual multiolefin levels ranging from 2 to 10 mol %.
[0035] The ionomer of the present invention may be obtained by reacting a halogenated copolymer with a nucleophile having no pendant vinyl group, a nucleophile comprising a pendant vinyl group or a mixture thereof. The halogenated copolymer may be reacted first with a nucleophile having no pendant vinyl group and then with a nucleophile having a pendant vinyl group.
[0036] Nucleophiles suitable for the preparation of the ionomers may contain at least one neutral phosphorus or nitrogen center, which possess a lone pair of electrons, the lone pair being both electronically and sterically accessible for participation in nucleophilic substitution reactions. The ionomers obtained from such nucleophiles would comprise phosphorus-based or nitrogen-based ionic moieties.
[0037] In one embodiment, the allylic halide sites of the halogenated copolymer are reacted with nucleophiles (with or without a pendant vinyl group) having of formula (I):
[0000]
[0038] wherein,
[0039] A is a nitrogen or phosphorus; and,
[0040] R 1 , R 2 and R 3 are independently: a vinyl group, a linear or branched C 1 -C 18 alkyl group; a linear or branched C 1 -C 18 alkyl group comprising one or more hetero atoms selected from the group consisting of O, N, S, B, Si and P; C 6 -C 10 aryl group; C 3 -C 6 heteroaryl group; C 3 -C 6 cycloalkyl group; C 3 -C 6 heterocycloalkyl group; or combinations thereof. If the nucleophile has a pendant vinyl group, the vinyl group may be one of R 1 , R 2 or R 3 or could be pendant from one or more of the R 1 , R 2 or R 3 groups. Two or all three of the R 1 , R 2 and R 3 moieties may be fused together.
[0041] Suitable nucleophiles include, but are not limited to trimethylamine, triethylamine, triisopropylamine, tri-n-butylamine, trimethylphosphine, triethylphosphine, triisopropylphosphine, tri-n-butylphosphine, triphenylphosphine, diphenylphosphinostyrene, allyldiphenylphosphine, diallylphenylphosphine, diphenylvinylphosphine, triallylphosphine, 2-dimethylaminoethanol, 1-dimethylamino-2-propanol, 2-(isopropylamino)ethanol, 3-dimethylamino-1-propanol, N-methyldiethanolamine, 2-(diethylamino)ethanol, 2-dimethylamino-2-methyl-1-propanol, 2-[2-(dimethylamino)ethoxy]ethanol, 4-(dimethylamino)-1-butanol, N-ethyldiethanolamine, triethanolamine, 3-diethylamino-1-propanol, 3-(diethylamino)-1,2-propanediol, 2-{[2-(dimethylamino)ethyl]methylamino}ethanol, 4-diethylamino-2-butyn-1-ol, 2-(diisopropylamino)ethanol, N-butyldiethanolamine, N-tert-butyldiethanolamine, 2-(methylphenylamino)ethanol, 3-(dimethylamino)benzyl alcohol, 2-[4-(dimethylamino)phenyl]ethanol, 2-(N-ethylanilino)ethanol, N-benzyl-N-methylethanolamine, N-phenyldiethanolamine, 2-(dibutylamino)ethanol, 2-(N-ethyl-N-m-toluidino)ethanol, 2,2′-(4-methylphenylimino)-diethanol, tris[2-(2-methoxyethoxy)ethyl]amine, 3-(dibenzylamino)-1-propanol, N-vinyl caprolactam, N-vinyl phthalimide, 9-vinyl carbazole, N-[3-(dimethylamino)propyl]methacrylamide or mixtures thereof.
[0042] To form the ionomer of the present invention the halogenated copolymer and nucleophile are mixed in an internal mixer, for example, a tangential mixer, an intermeshing mixer, a kneader or other mixer commonly used in the rubber industry. The reaction between the nucleophile and the halogenated copolymer may be carried out at an elevated temperature that may range from about 40-200° C. More preferably, the reaction between the nucleophile and the halogenated copolymer may be carried out at a temperature in a range of about 80-200° C. In another embodiment, the reaction between the nucleophile and the halogenated copolymer may be carried out at a temperature in a range of about 100-160° C. The nucleophile and the halogenated copolymer may be combined in a mixer and mixed for 0.5-30 minutes, preferably 1-20 minutes, more preferably 2-15 minutes, and even more preferably 5-10 minutes.
[0043] The resulting mixture from the may then be hot fed or cold fed through an extruder for 0.5-30 minutes, preferably 1-20 minutes, more preferably 2-15 minutes, and even more preferably 5-10 minutes.
[0044] The extruder may be heated to a temperature in a range of about 50-200° C., preferably about 60-175° C., and more preferably about 80-150° C. The extruder may be also be in combination with other extruders. Alternatively, the resulting mixture can be placed on a multi roll mill, preferably a two roll mill for about 0.5-90 minutes, preferably about 5-60 minutes, and more preferably about 10-30 minutes. The mill may be heated to a temperature in a range of about 50-200° C., preferably about 60-175° C., and more preferably about 80-150° C.
[0045] Suitable extruder types include single screw and multiscrew extruders comprising any number of barrels and types of screw elements and other single or multishaft conveying kneaders. Possible embodiments of multiscrew extruders are twin-screw extruders, ring extruders or planetary roller extruders, whereby twin-screw extruders are preferred. The extruder unit may comprise one or more extruders connected in series.
[0046] In a particularly preferred embodiment, the nucleophile and halogenated copolymer are first mixed in a mixer and then extruded through an extruder. Mixing in the mixer may be performed at ambient temperature or at temperatures of 40-200° C. Mixing in the mixer may be performed for 0.5-30 minutes. Extruding through the extruder may be performed at a temperature in a range of 80-150° C. Extruding through the extruder may be performed for 0.5-30 minutes.
[0047] In another embodiment of the invention, the ionomer may be in a strand, ribbon, pellet, fryable bale or compressed bale form.
[0048] To pelletize the ionomer either a dry or underwater pelletizer may be used. If a dry cut pelletizer is used, the temperature of the butyl rubber ionomer before cutting may be in a range of about 0-180° C., preferably about 5-160° C., and more preferably about 25-100° C. If an underwater pelletizer is used, the temperature of the water may be in a range of about 0.1-90° C., preferably about 1-70° C., more preferably about 2-40° C. and even more preferably about 10-30° C. An additive may or may not be added to the water in the underwater pelletizer and may include an emulsifier, an antifoaming agent, wetting agent, dispersant, surfactant, or thickener and may be anionic, cationic or nonionic emulsifier conventionally used for stabilizing oil-in-water emulsions. This effect is based on a reduction in the surface tension between an organic polymer phase and an aqueous phase, caused by the emulsifier. The definition of the emulsifier in particular covers emulsifiers which cause the value of the surface tension between an organic and an aqueous phase to be less than 10 mN/m, preferably less than 1 mN/m. By way of example, the definition covers aliphatic and/or aromatic hydrocarbons having from 8 to 30 carbon atoms which have a hydrophilic terminal group, preferably a sulphonate terminal group, sulphate terminal group, carboxylate terminal group, phosphate terminal group or ammonium terminal group. The definition also covers nonionic surfactants having functional groups, examples being polyalcohols, polyethers and/or polyesters. The definition also covers fatty acid salts, such as the sodium and/or potassium salts of oleic acid, the corresponding salts of alkylarylsulphonic acids and of naphthylsulphonic acid, and also covers condensates thereof, e.g. with formaldehyde, and also covers the corresponding salts of alkylsuccinic acid and of alkylsulphosuccinic acid. Additionally, linear alkyl polyether sulfonates, alkyl polyethylene glycol ethers, polyethylene glycol esters, block copolymers based on ethylene oxide and propylene oxide, glycerol, polyglycerol esters, ethoxylated sorbitan fatty acid esters, alcohol alkoxylates may be suitable emulsifiers. If used, the emulsifier may be added in an amount that the concentration of the emulsifier in water may be about 10-250,000 ppm, preferably about 50-100,000 ppm, and more preferably about 5000-50,000 ppm.
[0049] The pelletized ionomer may or may not be dusted. The dusting agent may be present on the surface of the pellet in an amount of about 0.01-10 wt %, preferably about 0.05-5 wt %, and more preferably about 0.1-4 wt %, based on the total weight of the ionomer pellet. Suitable dusting agents include, but are not limited to inorganic fillers such as calcium carbonate, aluminum silicate, calcium stearate, stearic acid, magnesium stearate, clays, talcs, kaolin, barytes, mica, silica, titanium dioxide, etc. as well as resins and polyethylene dust or combinations thereof.
[0050] In another embodiment of the invention, the amount of nucleophile reacted with the halogenated copolymer may be in the range of about 0.01-1.1 molar equivalents, more preferably about 0.05-1 molar equivalents, even more preferably about 0.2-0.8 molar equivalents, based on the total molar amount of allylic halide present in the halogenated copolymer. The resulting butyl rubber ionomer preferably possesses about 0.01-10 mol %, more preferably about 0.1-1.0 mol %, even more preferably about 0.2-0.8 mol %, yet even more preferably about 0.2-0.5 mol % of ionomeric moieties. The resulting butyl rubber ionomer may be a mixture of the polymer-bound ionomeric moiety and allylic halide such that the total molar amount of ionomeric moiety and allylic halide functionality are present in an amount not exceeding the original allylic halide content.
[0051] In an embodiment of the invention, the ionomer would have an amount of unreacted residual nucleophile or oxidative derivative thereof in a range of about 0-50%, preferably about 0.5-30%, and more preferably about 5-20% based on original amount of nucleophile added to the reaction mixture.
[0052] In another embodiment of the invention, the ionomer exhibits a ratio of reacted nucleophile to unreacted residual nucleophile or oxidative derivative thereof of at least 2.0, preferably 2.0 to 100.0, more preferably 2.5 to 100.0 even more preferably 2.5 to 20.0 and yet even more preferably 2.7 to 20.0.
[0053] The ionomer produced according to the process of the present invention has improved colour properties making the ionomer particularly suitable for films and coatings. The Yellowness Index, as defined in ASTM E313, is a measure of how far an object departs from a preferred white towards yellow. The Yellowness Index of the polymer, according to an embodiment of the present invention as measured according to ASTM E313 is between about 1-100, preferably between about 10-70, more preferably between about 20-60, even more preferably between about 20-41.
[0054] Without being bound to a particular theory, it is believed that the Yellowness Index can be at least partially correlated to polymer breakdown as indicated by the isoprene level in the final polymer. Degradation of the ionomer is most susceptible at the 1,4-isoprene multiolefin segments as opposed to the isobutene segments of the polymer chain. A decrease in the 1,4-isoprene level therefore indicates breakdown of the ionomer. This is not favored for a number of reasons, most notably that a reduction in reactive sites for vulcanization results in a lower state of cure and consequently, an article with poorer physical and dynamic properties.
[0000] Such breakdown is believed to proceed with exposure to elevated temperatures for extended time periods. Such conditions, however, are typically required to ensure a high conversion of the nucleophile employed to form the ionomers.
It is, therefore, surprising that the mixing and temperature regime according to the present invention allows both high conversion, while maintaining an acceptable degree of polymer breakdown.
In an embodiment of the invention, the final multiolefin content of the ionomer is between about 50-100%, preferably about 60-99% and more preferably about 75-99% based on the multiolefin content of the halogenated copolymer reacted to form the ionomer.
In another embodiment, the ionomer has a multiolefin content of 0.5 mol % or greater.
In another embodiment, the ionomer has a multiolefin content of from 0.5 mol % to 8.0 mol %, preferably of from 0.5 mol % to 2.0 mol %.
Additional ingredients may be combined with the halogenated copolymer and the nucleophile during the process described above to form a ionomer composite. These ingredients may include one or more of other polymers, elastomers, plastics, fillers, antioxidants, stabilizers, oils, tackifiers, gels, resins, process aides, accelerators, curatives or vulcanizing agents, cure retarders and other ingredients common to the rubber industry. The halogenated copolymer and the nucleophile combined, may be present in an amount of about 1-100 wt %, about 5-99 wt %, about 10-90 wt % or about 15-80 wt % of the total weight of the ionomer composite.
[0055] The ionomer described above may be used in a secondary process to form a cured or uncured compound. In either case, the compound may include other polymers, elastomers, plastics, fillers, antioxidants, stabilizers, oils, tackifiers, gels, resins, process aides, accelerators, cure retarders and other ingredients common to the rubber industry. If the ionomer is used in a cured compound, curatives or vulcanizing agents may be added.
[0056] Co-curable polymers include, for example, elastomers comprising one or more units of unsaturation. The one or more units of unsaturation are preferably carbon-carbon double bonds, such as in olefins and/or dienes. Diene elastomers are of particular note. The co-curable elastomer may be a butyl rubber elastomer, a non-butyl rubber elastomer or a mixture thereof. Some examples of butyl rubber elastomers include butyl rubber (IIR), bromobutyl rubber (BIIR), chlorobutyl rubber (CIIR), and mixtures thereof. Some examples of particular non-butyl rubber elastomers include isobutylene-methylstyrene (BIMS) rubber (commercially available under the trade name Exxpro™), ethylene propylene rubber (EPR), ethylene propylene diene monomer (EPDM) rubber, butadiene rubber (BR), solution styrene butadiene rubber (sSBR), emulsion styrene butadiene rubber (eSBR), acrylonitrile butadiene rubber (NBR), hydrogenated acrylonitrile butadiene rubber (HNBR), natural rubber (NR), epoxidized natural rubber (ENR), polyurethane (PU), polyisoprene rubber, polyacrylic or polyacrylate (ACM), chloroprene (CR), chlorosulphonylpolyethylene or chlorosulphonatedpolyethylene (CSM), ethylene acrylic (AEM), thermoplastic polyester urethane (AU), thermoplastic polyether urethane (EU), epichlorohydrin (ECO), fluoroethylene propylene-perfluoroalkoxy (FEP or PFA), tetrafluoroethylene/propylene (FEPM or TFE/P), perfluoroelastomer (FFKM/FFPM), fluoroelastomer or fluorocarbon (FKM/FPM), fluorosilicone (FVMQ), silicone (VMQ/PVMQ), polytetrafluoroethylene (PTFE), ethylene vinylacetate (EVA) rubber, ethylene acrylate rubber, polyurethane rubber, polyisobutylene (PIB), chlorinated polyethylene (CPE), polynorbornene rubber (PNB), polysulphide rubber (TR), styrene-butadiene-styrene (SBS), styrene-butadiene rubber (SBR), styrene-butadiene (SB), styrene-isoprene-styrene(SIS), styrene-isoprene-butadiene-styrene (SIBS), atactic polypropylene (APP), isotactic polypropylene, ethylene-propylene copolymer, thermoplastic polyolefin (TPO), amorphous poly alpha olefin (APAO) or polyethylene (PE), ethyl vinyl acetate (EVA) and the like and mixtures thereof.
[0057] Fillers may be non-mineral fillers, mineral fillers or mixtures thereof. Non-mineral fillers may include, for example, carbon blacks, rubber gels and mixtures thereof. Suitable carbon blacks are preferably prepared by lamp black, furnace black or gas black processes. Carbon blacks preferably have BET specific surface areas of about 20-200 m 2 /g. Some specific examples of carbon blacks are SAF, ISAF, HAF, FEF and GPF carbon blacks. Rubber gels are preferably those based on polybutadiene, butadiene/styrene copolymers, butadiene/acrylonitrile copolymers or polychloroprene. Suitable mineral fillers comprise, for example, silica, silicates, clay, bentonite, vermiculite, nontronite, beidelite, volkonskoite, hectorite, saponite, laponite, sauconite, magadiite, kenyaite, ledikite, gypsum, alumina, talc, glass, metal oxides (e.g. titanium dioxide, zinc oxide, magnesium oxide, aluminum oxide), metal carbonates (e.g. magnesium carbonate, calcium carbonate, zinc carbonate), metal hydroxides (e.g. aluminum hydroxide, magnesium hydroxide) or mixtures thereof. Dried amorphous silica particles suitable for use as mineral fillers may have a mean agglomerate particle size in the range of about 1-100 microns, or about 10-50 microns, or about 10-25 microns. Suitable amorphous dried silica may have, for example, a BET surface area, measured in accordance with DIN (Deutsche Industrie Norm) 66131, of about 50-450 square meters per gram. DBP absorption, as measured in accordance with DIN 53601, may be about 150-400 grams per 100 grams of silica. A drying loss, as measured according to DIN ISO 787/11, may be about 0-10 wt %. Suitable silica fillers are commercially sold under the names HiSil™ 210, HiSil™ 233 and HiSil™ 243 available from PPG Industries Inc. Also suitable are Vulkasil™ S and Vulkasil™ N, commercially available from Bayer AG. High aspect ratio fillers may include clays, talcs, micas, etc. with an aspect ratio of at least 1:3. The fillers may include acircular or nonisometric materials with a platy or needle-like structure. The aspect ratio is defined as the ratio of mean diameter of a circle of the same area as the face of the plate to the mean thickness of the plate. The aspect ratio for needle and fiber shaped fillers is the ratio of length to diameter. The high aspect ratio fillers may have an aspect ratio of at least 1:5, or at least 1:7, or in a range of 1:7 to 1:200. High aspect ratio fillers may have, for example, a mean particle size in the range of from 0.001 to 100 microns, or 0.005 to 50 microns, or 0.01 to 10 microns. Suitable high aspect ratio fillers may have a BET surface area, measured in accordance with DIN (Deutsche Industrie Norm) 66131, of between 5 and 200 square meters per gram. The high aspect ratio filler may comprise a nanoclay, such as, for example, an organically modified nanoclay. Examples of nanoclays include natural powdered smectite clays (e.g. sodium or calcium montmorillonite) or synthetic clays (e.g. hydrotalcite or laponite). In one embodiment, the high aspect filler may include organically modified montmorillonite nanoclays. The clays may be modified by substitution of the transition metal for an onium ion, as is known in the art, to provide surfactant functionality to the clay that aids in the dispersion of the clay within the generally hydrophobic polymer environment such as onium ions that are phosphorus based (e.g. phosphonium ions) or nitrogen based (e.g. ammonium ions) and contain functional groups having from 2 to 20 carbon atoms. The clays may be provided, for example, in nanometer scale particle sizes, such as, less than 25 μm by volume. The particle size may be in a range of from 1 to 50 μm, or 1 to 30 μm, or 2 to 20 μm. In addition to silica, the nanoclays may also contain some fraction of alumina. For example, the nanoclays may contain from 0.1 to 10 wt % alumina, or 0.5 to 5 wt % alumina, or 1 to 3 wt % alumina. Examples of commercially available organically modified nanoclays as high aspect ratio mineral fillers include, for example, those sold under the trade name Cloisite® clays 10A, 20A, 6A, 15A, 30B, or 25A.
[0058] The ionomer may be present in the blend in an amount of about 1-99 phr, or about 1-90 phr, or about 5-75 phr, or less than 50 phr, or about 1-50 phr, or about 1 phr to less than about 50 phr, or about 10-50 phr, or about 5-30 phr, or about 15-30 phr. Fillers may be present in the blend in an amount of about 1-100 phr, or about 3-80 phr, or about 5-60 phr, or about 5-30 phr, or about 5-15 phr.
[0059] Ingredients may be compounded together using conventional compounding techniques. Suitable compounding techniques include, for example, mixing the ingredients together using, for example, an internal mixer (e.g. a Banbury mixer), a miniature internal mixer (e.g. a Haake or Brabender mixer) or a two roll mill mixer. An extruder also provides good mixing, and permits shorter mixing times. It is possible to carry out the mixing in two or more stages, and the mixing can be done in different apparatuses, for example one stage in an internal mixer and one stage in an extruder. For further information on compounding techniques, see Encyclopedia of Polymer Science and Engineering, Vol. 4, p. 66 et seq. (Compounding). Other techniques, as known to those of skill in the art, are further suitable for compounding.
[0060] The choice of curing system suitable for use is not particularly restricted and is within the purview of a person skilled in the art. In certain embodiments, the curing system may be sulphur-based, peroxide-based, resin-based or ultraviolet (UV) light-based.
[0061] A sulfur-based curing system may comprise: (i) a metal oxide, (ii) elemental sulfur and (iii) at least one sulfur-based accelerator. The use of metal oxides as a component in the sulphur curing system is well known in the art. A suitable metal oxide is zinc oxide, which may be used in the amount of from about 1 to about 10 phr. In another embodiment, the zinc oxide may be used in an amount of from about 2 to about 5 phr. Elemental sulfur, (component (ii)), is typically used in amounts of from about 0.2 to about 2 phr. Suitable sulfur-based accelerators (component (iii)) may be used in amounts of from about 0.5 to about 3 phr. Non-limiting examples of useful sulfur-based accelerators include thiuram sulfides (e.g. tetramethyl thiuram disulfide (TMTD)), thiocarbamates (e.g. zinc dimethyl dithiocarbamate (ZDC)) and thiazyl or benzothiazyl compounds (e.g. mercaptobenzothiazyl disulfide (MBTS)). A sulphur based accelerator of particular note is mercaptobenzothiazyl disulfide.
[0062] Peroxide based curing systems may also be suitable, especially for ionomers comprising residual multiolefin content in excess of about 0.2 mol %. A peroxide-based curing system may comprises a peroxide curing agent, for example, dicumyl peroxide, di-tert-butyl peroxide, benzoyl peroxide, 2,2′-bis(tert.-butylperoxy diisopropylbenzene (Vulcup® 40KE), benzoyl peroxide, 2,5-dimethyl-2,5-di(tert-butylperoxy)-hexyne-3, 2,5-dimethyl-2,5-di(benzoylperoxy)hexane, (2,5-bis(tert-butylperoxy)-2,5-dimethyl hexane and the like. One such peroxide curing agent comprises dicumyl peroxide and is commercially available under the name DiCup 40C. Peroxide curing agents may be used in an amount of about 0.2-7 phr, or about 1-6 phr, or about 4 phr. Peroxide curing co-agents may also be used. Suitable peroxide curing co-agents include, for example, triallyl isocyanurate (TAIC) commercially available under the name DIAK 7 from DuPont, N,N′-m-phenylene dimaleimide known as HVA-2 from DuPont or Dow), triallyl cyanurate (TAC) or liquid polybutadiene known as Ricon D 153 (supplied by Ricon Resins). Peroxide curing co-agents may be used in amounts equivalent to those of the peroxide curing agent, or less. The state of peroxide cured articles is enhanced with butyl polymers containing increased levels of unsaturation, for example a multiolefin content of at least 0.5 mol %.
[0063] The blend may be cured by resin cure system and, if required, an accelerator to activate the resin cure. Suitable resins include but are not limited to phenolic resins, alkylphenolic resins, alkylated phenols, halogenated alkyl phenolic resins and mixtures thereof. In some cases, curing may be achieved by heating the blend at a suitable curing temperature in the presence of the curing system. The curing temperature may be about 80° C. to about 250° C., or 100° C. to about 200° C., or about 120° C. to about 180° C.
[0000] Addition of ionomer as an additive to a co-curable elastomer may result in improvement in one or more of green strength of the uncured blend, flex fatigue ratio, adhesion, tear strength, damping, traction and crack growth resistance as described in EP13183546.4.
Ionomer composites may be shaped into a desired article prior to curing. Articles comprising the cured elastomeric compound include, for example, belts, hoses, shoe soles, gaskets, o-rings, wires/cables, membranes, rollers, bladders (e.g. curing bladders), inner liners of tires, tire treads, shock absorbers, machinery mountings, balloons, balls, golf balls, protective clothing, medical tubing, storage tank linings, electrical insulation, bearings, pharmaceutical stoppers, adhesives, a container, such as a bottle, tote, storage tank, etc.; a container closure or lid; a seal or sealant, such as a gasket or caulking; a material handling apparatus, such as an auger or conveyor belt; a cooling tower; a metal working apparatus, or any apparatus in contact with metal working fluids; an engine component, such as fuel lines, fuel filters, fuel storage tanks, gaskets, seals, etc.; a membrane, for fluid filtration or tank sealing. Additional examples where the ionomers may be used in articles or coatings include, but are not limited to, the following: appliances, baby products, bathroom fixtures, bathroom safety, flooring, food storage, garden, kitchen fixtures, kitchen products, office products, pet products, sealants and grouts, spas, water filtration and storage, equipment, food preparation surfaces and equipment, shopping carts, surface applications, storage containers, footwear, protective wear, sporting gear, carts, dental equipment, door knobs, clothing, telephones, toys, catheterized fluids in hospitals, surfaces of vessels and pipes, coatings, food processing, biomedical devices, filters, additives, computers, ship hulls, shower walls, tubing to minimize the problems of biofouling, pacemakers, implants, wound dressing, medical textiles, ice machines, water coolers, fruit juice dispensers, soft drink machines, piping, storage vessels, metering systems, valves, fittings, attachments, filter housings, linings, and barrier coatings.
EXAMPLES
Materials and Reagents
[0064] BB2030 (LANXESS), RB301 (LANXESS), Bayprene 210 (LANXESS), zinc oxide (St. Lawrence Chemical Company), carbon black (Cabot), triphenylphosphine (Alfa Aesar), triphenylphosphine oxide (Sigma Aldrich), stearic acid (HM Royal), WBC-41P (5 phr Zinc Oxide, 6.4 phr LANXESS Butyl 301, 10 phr SP1045 Resin, Rhein Chemie), Castor Oil (Alfa Aesar) were all used as received from their respective suppliers.
[0000] Compound testing equipment and procedures:
[0000] TABLE 1 Equipment/Test Method ASTM # MDR 200 (Moving Dye Rheometer) ASTM D 5289 Mooney Viscometer ASTM D 1646 Alpha Technologies T2000 ASTM D 412 ASTM D 624 Yellowness Index ASTM E313
For yellowness index, samples were pressed into a 6″×6″ sheet that was 2 mm thick and placed on a white tile and an average of 5 measurements were taken.
Example 1
[0065] Comparative Example as Described in U.S. Pat. No. 7,662,480:
[0066] 48 g (100 phr) of LANXESS BB2030™ and 4.7 g (9.7 phr, 3 molar equivalents based on allylic bromide content) of triphenylphosphine were added to a Brabender internal mixer (capacity 75 g) operating at 100° C. and a rotor speed of 60 rpm. Mixing was carried out for a total of 60 minutes. The resulting properties are shown in Table 2, most notably, a significant amount of residual/unbound TPP and its oxidized derivative triphenylphosphine oxide (TPP=O).
Example 2
[0067] Comparative Example as Described in WO 2012083419:
[0068] LANXESS BB2030™ (100 phr) was allowed to mix alone for a short period of time before the addition of the TPP (4.3 phr) and mixed for 10 minutes. The resulting properties are shown in Table 2, most notably, a residual/unbound TPP and its oxidized derivative triphenylphosphine oxide (TPP=O) indicating 65% conversion.
Example 3
[0069] Example of the Present Invention
[0070] LANXESS BB2030™ (100 phr) was added to a Banbury mixer, followed by the addition of triphenylphosphine (3 phr, 0.6 molar equivalents based on allylic bromide content) and mixed for 6 minutes. The mixture was then passed through a single screw extruder heated to 100° C. The resulting properties are shown in Table 2. Comparison of Example 3 to Example 1 and Example 2 show a lower amount of residual TPP and TPP=O. Additionally, Example 2 and Example 3 demonstrate comparable ionic content, indicating the improved efficiency of the process outlined in Example 3 (84% conversion).
[0000]
TABLE 2
1,4-
Active
Ionic
Unbound
isoprene
Bromine
Content
TPP/TPP = O
Yellowness
(mol %)
(mol %)
(mol %)
(mol %)
Index
Example 1
0.54
0.10
0.82
1.34
46
Example 2
0.57
0.24
0.54
0.38
43
Example 3
0.57
0.27
0.50
0.18
41
Example 4
0.40
0.20
0.40
0.45
105
Example 4
[0071] Comparative Example as Described in US 2013/0217833:
[0072] The formation of an ionomer as described in Example 2 of US 2013/0217833 resulted in an ionomer with the resulting properties are shown in Table 2. In addition to residual unbound TPP/TPP=O, a decrease in 1,4-isoprene (denoting polymer breakdown) and significant increase in yellowness index are observed when compared to Example 3.
Example 5-7
[0073] To demonstrate the negative impact of residual TPP/TPP=O on a vulcanized compound, TPP (Example 6) and TPP=O (Example 7) were incorporated into a traditional, butyl-based-resin cured formulation (Example 5) as outlined in Table 3. Referring to Table 4, both the addition of TPP and TPP=O results in poorer state of cure and subsequent poorer compound properties, highlighting the advantage of lower amount of residual TPP and TPP=O.
[0000]
TABLE 3
5
6
7
LANXESS Butyl 301
66.25
66.25
66.25
LANXESS Bromobutyl
24
24
24
2030
LANXESS Baypren 210
3.75
3.75
3.75
Carbon Black, N330
50
50
50
Castor Oil
5
5
5
Stearic Acid
0.5
0.5
0.5
Zinc Oxide
2
2
2
WBC-41P
12.8
12.8
12.8
Triphenylphosphine
0
1
0
Triphenylphosphine
0
0
1
Oxide
[0000]
TABLE 4
5
6
7
Triphenylphosphine
0
1
0
Triphenylphosphine Oxide
0
0
1
Cure Characteristics
Delta M H − M L (dN.m)
12.69
8.29
10.88
Compound Properties
Mooney Viscosity (M L 1 + 4, @ 100° C.,
77
77
78
MU)
Mooney Scorch (t′05, min)
11
17
15
Ultimate Tensile (MPa)
13.1
9.4
11.4
Ultimate Elongation (%)
645
968
692
Stress @ 100 (MPa)
2.0
1.6
1.8
Stress @ 300 (MPa)
6.1
3.7
4.9
M300/100
3.1
2.3
2.7
Elongation Set (%)
8
22
16
Tear Strength Unaged (kN/m)
53
15
32
[0074] All documents cited herein are incorporated herein by reference.
[0075] The novel features will become apparent to those of skill in the art upon examination of the description. It should be understood, however, that the scope of the claims should not be limited by the embodiments, but should be given the broadest interpretation consistent with the wording of the claims and the specification as a whole. | There is provided a process for producing an ionomer comprising the steps of (a) admixing in a mixer a halogenated copolymer with at least one nitrogen and/or phosphorus based nucleophile and (b) extruding the mixture from step (a). The process takes place with high conversion and the resulting ionomer contains a low amount of residual nucleophile and has a low yellowness index. | 2 |
REFERENCE TO RELATED APPLICATION AND PRIORITY CLAIM
This application expressly claims the benefit of earlier filing date and right of priority from the following patent application: U.S. Provisional Application Ser. No. 60/075,953 filed on Feb. 25, 1998 in the names of Cook et al and entitled "ELECTRIC-OPERATED, PUMP-TYPE VAPOR LEAK DETECTION MODULE". The entirety of that earlier-filed, co-pending patent application is hereby expressly incorporated herein by reference.
FIELD OF THE INVENTION
This invention relates generally to a module for an on-board leak detection system that detects fuel vapor leakage from an evaporative emission space of an automotive vehicle fuel system, and more especially to an electric-operated, pump-type module for such a leak detection system.
BACKGROUND OF THE INVENTION
A known on-board evaporative emission control system for an automotive vehicle comprises a vapor collection canister that collects volatile fuel vapors generated in the headspace of the fuel tank by the volatilization of liquid fuel in the tank and a purge valve for periodically purging fuel vapors to an intake manifold of the engine. A known type of purge valve, sometimes called a canister purge solenoid (or CPS) valve, comprises a solenoid actuator that is under the control of a microprocessor-based engine management system, sometimes referred to by various names, such as an engine management computer or an engine electronic control unit.
During conditions conducive to purging, evaporative emission space that is cooperatively defined primarily by the tank headspace and the canister is purged to the engine intake manifold through the canister purge valve. A CPS-type valve is opened by a signal from the engine management computer in an amount that allows intake manifold vacuum to draw fuel vapors that are present in the tank headspace and/or stored in the canister for entrainment with combustible mixture passing into the engine's combustion chamber space at a rate consistent with engine operation so as to provide both acceptable vehicle driveability and an acceptable level of exhaust emissions.
Certain governmental regulations require that certain automotive vehicles powered by internal combustion engines which operate on volatile fuels such as gasoline, have evaporative emission control systems equipped with an on-board diagnostic capability for determining if a leak is present in the evaporative emission space. It has heretofore been proposed to make such a determination by temporarily creating a pressure condition in the evaporative emission space which is substantially different from the ambient atmospheric pressure, and then watching for a change in that substantially different pressure which is indicative of a leak.
It is believed fair to say that there are two basic types of vapor leak detection systems for determining integrity of an evaporative emission space: a positive pressure system that performs a test by positively pressurizing an evaporative emission space; and a negative pressure (i.e. vacuum) system that performs a test by negatively pressurizing (i.e. drawing vacuum in) an evaporative emission space.
Commonly owned U.S. Pat. No. 5,146,902 discloses a positive pressure system. Commonly owned U.S. Pat. No. 5,383,437 discloses the use of a reciprocating pump to create positive pressure in the evaporative emission space. Commonly owned U.S. Pat. No. 5,474,050 embodies advantages of the pump of U.S. Pat. No. 5,383,437 while providing certain improvements in the organization and arrangement of a reciprocating pump.
SUMMARY OF THE INVENTION
One general aspect of the invention relates to a module for an on-board evaporative emission leak detection system that detects leakage from an evaporative emission space of a fuel system of an automotive vehicle, the module comprising: an enclosure comprising an interior space adapted to be communicated to atmosphere; a pump disposed within the interior space comprising a pumping chamber having an inlet in communication with the interior space and a flow passage for communicating the pumping chamber with an evaporative emission space to allow the evaporative emission space to be pressurized by the pump; a vent valve that is disposed within the interior space and is selectively operable to a first state that vents the flow passage to the interior space to thereby vent the evaporative emission space to atmosphere and to a second state that does not vent the flow passage to the interior space; and an electric-operated actuator mechanism, including an electric actuator, disposed within the interior space for operating the pump and the vent valve to perform a leak test on the evaporative emission space; the mechanism comprising a lever operatively coupling the actuator with one of the pump and the vent valve, the lever being mounted for pivotal motion about a pivot axis and comprising a lever arm; and a stop that is disposed to be abutted by the lever arm and is positionable relative to the lever arm for calibrating the lever to secure a desired relationship between electric actuator and the one of the pump and the vent valve.
Another general aspect relates to a method of calibrating a leak detection module pump in terms of a known pre-set stroke of a moveable pump wall comprising: providing a positive displacement pump comprising a wall that is reciprocally stroked to operate the pump; providing an electric-operated actuator mechanism, including an electric actuator and a pivotally mounted lever having a lever arm, for reciprocally stroking the pump; providing a positionable stop that is disposed to be abutted by the lever arm to define a limit of pivotal motion of the lever arm; and calibrating the lever arm by positioning the stop relative to the lever arm to a calibration position that secures a desired relationship between the electric actuator and the pump.
BRIEF DESCRIPTION OF THE DRAWINGS
The accompanying drawings, which are incorporated herein and constitute part of this specification, include one or more presently preferred embodiments of the invention, and together with a general description given above and a detailed description given below, serve to disclose principles of the invention in accordance with a best mode contemplated for carrying out the invention.
FIG. 1 is a general schematic diagram of an exemplary automotive vehicle evaporative emission control system including a leak detection system and module embodying principles of the invention.
FIG. 2 is a plan view showing the interior of a first embodiment of module.
FIG. 3 is a plan view showing the interior of a second embodiment of module.
FIG. 4 is an enlarged view in the direction of arrows 4--4 in FIG. 3.
FIG. 5 is a transverse cross section view in the direction of arrows 5--5 in FIG. 4.
FIG. 6 is a plan view showing the interior of a third embodiment of module.
DESCRIPTION OF THE PREFERRED EMBODIMENT
FIG. 1 shows an automotive vehicle evaporative emission control (EEC) system 10 in association with an internal combustion engine 12 that powers the vehicle, a fuel tank 14 that holds a supply of volatile liquid fuel for the engine, and an engine management computer (EMC) 16 that exercises certain controls over operation of engine 12. EEC system 10 comprises a vapor collection canister (charcoal canister) 18, a proportional purge solenoid (PPS) valve 20, a leak detection module (LDM) 22, and a particulate filter 24. In the illustrated schematic, module 22 and canister 18 are portrayed as discrete components, but they could alternatively be integrated into one assembly.
A tank headspace port 14a that communicates with headspace of fuel tank 14, a tank port 18a of canister 18, and an inlet port 20a of PPS valve 20 are placed in common fluid communication by a conduit 26. Another conduit 28 fluid-connects an outlet port 20b of PPS valve 20 with an intake manifold 29 of engine 12. Another conduit 30 fluid-connects a port 22a of module 22 to atmosphere via filter 24. Another conduit 32 fluid-connects a port 22b of module 22 with a vent port 18b of canister 18. Headspace of tank 14, canister 18, and associated conduits collectively define evaporative emission space within which fuel vapors generated by volatilization of fuel in tank 14 are temporarily confined and collected until purged to intake manifold 29 via opening of PPS valve 20.
EMC 16 receives a number of inputs, collectively designated 34, (engine-related parameters for example) relevant to control of certain operations of engine 12 and its associated systems, including EEC system 10. One electrical output port of EMC 16 controls PPS valve 20 via an electrical connection 36; other ports of EMC 16 are coupled with module 22 via electrical connections, depicted generally by the reference numeral 38.
From time to time, EMC 16 commands module 22 to an active state as part of an occasional leak detection test procedure for ascertaining the integrity of EEC system 10, particularly the evaporative emission space that contains volatile fuel vapors, against leakage. During occurrences of such a diagnostic procedure, EMC 16 commands PPS valve 20 to close. At times of engine running other than during such leak detection procedures, module 22 reposes in an inactive state, and in doing so provides an open vent path from the evaporative emission space, through itself and filter 24, to atmosphere. A vapor adsorptive medium within canister 18 prevents escape of fuel vapor to atmosphere during such venting.
EMC 16 selectively operates PPS valve 20 such that the valve opens under conditions conducive to purging and closes under conditions not conducive to purging. Thus, during times of operation of the automotive vehicle, the canister purge function is performed in a manner suitable for the particular vehicle and engine so long as the leak detection test procedure is not being performed. When the leak detection test procedure is being performed, the canister purge function is not performed. During a leak detection test, the evaporative emission space is isolated from both atmosphere and the engine intake manifold so that it can be initially positively pressurized by module 22, and the pressure thereafter allowed to decay if leakage is present.
FIG. 2 discloses a module 100 comprising a walled enclosure 102 that has been opened to reveal the contents of its interior space 103. An electromagnet assembly 104 and a pump assembly 106 are disposed within interior space 103, and each is securely mounted, such as by fastening to an enclosure wall using screws 108 passing through apertures in each assembly.
Electromagnet assembly 104 comprises two non-ferromagnetic retaining plates 110 that are C-shaped as viewed in plan and that sandwich between them a similarly shaped portion of a ferromagnetic core that comprises an E-shaped stack 109 of ferromagnetic laminations. As viewed in plan, E-shaped stack 109 includes three parallel legs, namely two outer legs 122a, 124a, and a middle leg 111. Electromagnet 112 further comprises a plastic bobbin 114 containing an electromagnet coil 116. Bobbin 114 fits onto middle leg 111 of stack 109 with its axis 119 coincident with middle leg 111. Outer legs 122a, 124a are sandwiched between corresponding legs 122, 124 of retaining plates 110, and screws 108 pass through them as shown to fasten assembly 104 to enclosure 102. The distal ends of legs 122, 124 comprise respective pivots that serve to mount respective toggle levers 126, 128 for pivotal motion about respective parallel axes 130, 132 that are perpendicular to legs 122, 124.
Each lever 126, 128 comprises a formed ferromagnetic part 127, 129 respectively that places it in magnetic circuit relationship with electromagnet 112. Each part may be considered to have two lever arms that are disposed at approximately right angles to one another. Part 127 of lever 126 comprises lever arms 126a, 126b, and part 129 of lever 128, lever arms 128a, 128b. Proximate the proximal ends of its two lever arms, each part 127, 129 comprises a pair of apertured tabs 134 that are bent at right angles to each side of the lever so that the apertured tabs of each pair are disposed mutually parallel and with their circular apertures axially aligned. Each pair of apertured tabs 134 provides for the mounting of the respective lever on the pivot at the distal end of a respective frame leg 122, 124, such as by means of a pivot pin 136.
The distal end of each lever arm 126a, 128a is disposed proximate an axial end of electromagnet 112 and contains a hole for mounting a respective grommet-like bumper 138. Each bumper 138 comprises a head that faces core 118 and protrudes sufficiently from the respective lever arm that it, rather than the respective lever arm part 127, 129, would abut core 118 when the electromagnet is operated in a manner to be explained later.
The distal ends of lever arms 126b, 128b are operatively associated with pump assembly 106. The distal end of lever arm 126b has a direct connection with a pumping mechanism 140 of pump assembly 106. The distal end of lever arm 128b carries a closure 142 that selectively associates with and disassociates from pump assembly 106 to form a vent valve 143.
Pump assembly 106 comprises a housing 144 that is mounted on enclosure 102 by passing screws 108 through apertured tabs at the sides of the housing base. Pumping mechanism 140 is disposed at one end of housing 144, and that end comprises a circular flange 146. Housing 144 further comprises a tubular wall 148 extending from flange 146 to an opposite end of the housing.
Pumping mechanism 140 comprises a movable wall 150 having a circular perimeter margin disposed against a rim 152 of flange 146. Wall 150 is shown to comprise a flexible, but fluid-impermeable, part 154 and a rigid part 156, stamped metal for example. Part 154 is a fuel-tolerant elastomeric material that is molded to part 156 by known insert-molding methods, thereby intimately uniting the two parts 154, 156 into an assembly. The outer perimeter margin of movable wall 150 comprises a circular bead 158 in part 154. Rim 152 comprises a circular groove 160 within which bead 158 is disposed. Bead 158 is held in groove 160 by a circular clinch ring 162 which is fitted over the abutted perimeter margins of wall 150 and flange 146 and which has an outer perimeter that is deformed and crimped onto the abutted perimeter margins of wall 150 and flange 146 in the manner shown. This serves to seal the two perimeter margins together so that a pumping chamber 164 is cooperatively defined by wall 150 and flange 146.
Pumping chamber 164 may be considered to have an axis 166 that is concentric with flange 146 and wall 150. Axis 166 is offset from an axis 168 of tubular wall 148. Tubular wall 148 comprises a passage 170 extending along axis 168 from pumping chamber 164 and opening to the interior space 103 of enclosure 102 at the end of housing 144 opposite pumping chamber 164. Intermediate its opposite ends, passage 170 is intersected by a canister passage 172 that is adapted to be placed in communication with canister 18. Canister passage 172 is formed in enclosure 102 and extends from its intersection with passage 170 to terminate in an external nipple 174 that forms port 22b and is available at the exterior of enclosure 102 for association with conduit 32.
A one-way valve 176 is disposed between pumping chamber 164 and passage 170 to allow fluid flow in a direction from pumping chamber 164 into passage 170, but not in an opposite direction. Valve 176 comprises an elastomeric umbrella valve element 178 mounted on an appropriately apertured internal wall of housing 144 that separates pumping chamber 164 from passage 170. Spaced from valve 176 circumferentially about axis 166 is a second one-way valve 180 comprising an umbrella valve element 181. Valve 180 has a construction like that of valve 176, but element 181 is mounted on an external wall of housing 144 to allow fluid flow in a direction from the interior space 103 of enclosure 102 into pumping chamber 164, but not in an opposite direction.
The walls of housing 144 that contain valves 176, 180 comprises respective depressions 182, 184 which are disposed in a housing surface 186 circumferentially spaced about a central post 188 that stands on surface 186 along axis 166. One axial end of a helical coil spring 190 is disposed over post 188 to bear against surface 186. Part 156 is formed to have a central tower 192 disposed over the opposite axial end of spring 190. That axial end of spring 190 bears against an end wall of tower 192.
Part 154 comprises an annulus 194 whose outside diameter (O.D.) joins with bead 158. The inside diameter (I.D.) of annulus 194 joins with a bead 196 that is molded onto the free edge of a flange 198 of part 156 at the base of tower 192. Bead 196 has a thickness as measured in a direction parallel with axis 166 that exceeds the thickness of flange 198, extending beyond the flange in both axial directions. Material of part 154 adheres to part 156 in covering relation to the entirety of the surface of the part that is circumferentially bounded by bead 196 externally of pumping chamber 164.
On the exterior of the end wall of tower 192, part 154 comprises a grommet-like post 200 that projects coaxially of axis 166 away from the tower. Intermediate its axial length, post 200 comprises a groove 202 fitting the post to the margin of a circular hole through the distal end of lever arm 126b. Between groove 202 and tower 192, post 200 comprises a bulk of molded elastomeric material 203 of part 154, and to the opposite axial side of groove 202, post 200 comprises a blunt, frusto-conically tapered nose 204 that is shaped to allow lever 126 to be operatively connected to pumping mechanism 140 by inserting nose 204 into and through the circular hole in lever arm 126b until groove 202 becomes fitted to the hole's margin. FIG. 2 shows spring 190 resiliently biasing movable wall 150 in a direction axially away from pumping chamber 164 to cause bead 196 to abut a radially inner margin of clinch ring 162 in the manner shown.
Closure 142 comprises a rigid disk 206, stamped metal for example, onto which elastomeric material 208 has been insert molded so that the two are intimately united to form an assembly. The elastomeric material forms a grommet-like post 210 that projects perpendicularly away, and to one axial side of, the center of disk 206. Post 210 comprises an axially central groove 212 providing for the attachment of closure 142 to the distal end of lever arm 128b in the same manner as the attachment of lever arm 126b to post 200. At the outer margin of disk 206, the elastomeric material is formed to provide a lip seal 214 that is generally frusto-conically shaped and canted inward and away from disk 206 on the axial side of the disk opposite post 210.
Enclosure 102 comprises a second nipple 216 that forms port 22a and is available on the enclosure exterior for association with conduit 30. This provides for interior space 103 to be continuously vented to atmosphere through filter 24.
The positions of the various parts of module 100 shown in FIG. 2 represent a condition where module 100 is in its inactive state. In that state, lever 128 is biased clockwise about axis 132 by a torsion spring 218 to cause closure 142 to be spaced apart from housing 144, thereby holding vent valve 143 open. Consequently, the evaporative emission space is vented to atmosphere through a vent path comprising conduit 32, passage 172, passage 170, interior space 103, conduit 30, and filter 24. When a leak detection test is to be performed, EMC 16 operates module 100 to an active state, and PPS valve 20, closed.
In the active state of module 100, electromagnet 112 is energized by a driver circuit to pivot lever 128 counterclockwise from the position shown in FIG. 2, thereby swinging closure 142 over a small acute angle about axis 132 to seal the open end of passage 170 closed due to the action of lip seal 214 with the end surface of housing 144 around passage 170. Consequently, the evaporative emission space under test is no longer vented to atmosphere because the vent path through vent valve 143 has now been closed. The electric current supplied to coil 116 by the driver circuit may be considered to comprise a first component that causes electromagnet 112 to exert a force on lever arm 128a that, in conjunction with the force vs. deflection characteristic of torsion spring 218, the inertial mass pivotally mounted about axis 132, and the pressure differential acting on closure 142, maintains closure 142 sealed closed against the end surface of housing 144 around passage 170 while module 100 continues to be in its active state.
The electric current supplied to coil 116 may be considered to also comprise a second component that is effective to cause electromagnet 112 to oscillate, or toggle, lever 126 during the active state of module 100, and thereby operate pumping mechanism 140, while the vent path to atmosphere remains closed. Movable wall 150 executes a pumping stroke, or downstroke, as lever 126 pivots clockwise about axis 130 from the position shown in FIG. 1, due to attraction of lever arm 126a toward armature core 118. Such stroking causes a charge of air that is in pumping chamber 164 to be compressed, and thence a portion of the compressed charge expelled through valve 176, into passage 170, into passage 172, and ultimately into the evaporative emission space being tested. The pump downstroke is limited by abutment of bead 196 with surface 186, and when that occurs, the consequent lack of further compression of the air charge prevents valve 176 from remaining open.
Electromagnet 112 then releases lever 126, and the action of spring 190 causes movable wall 150 to execute a charging stroke, or upstroke, in a direction away from pumping chamber 164. During the upstroke, valve 176 remains closed, but a pressure differential across valve 180 causes the latter valve to open. Now atmospheric air from interior space 103 can enter pumping chamber 164 through valve 180. At the end of the upstroke, bead 196 abuts clinch ring 162 at which time a charge of air has once again been created in pumping chamber 164. At that time, valve 180 closes due to lack of sufficient pressure differential to maintain it open. Pumping mechanism 140 is then once again downstroked by electromagnet 112 to commence the next pumping stroke wherein a charge of air is compressed, and a portion of the compressed charge is forced into the evaporative emission space.
Pumping mechanism 140 is repeatedly stroked in this manner until pressure suitable for performing a leak detection test has been created in the evaporative emission space under test. The component of electric current in coil 116 that oscillates, or reciprocally swings, lever 126 has a pulsing, or oscillating, characteristic that is chosen in relation to the inertial mass that is pivoted about axis 130 and the operating characteristic of spring 190 that pumping mechanism 140 can follow the oscillating, or pulsing, current component. Hence, spring 190 is much stiffer than spring 218.
Pressure sensing may be performed by a pressure sensor, or pressure switch, (not specifically illustrated in FIG. 2) disposed in association with enclosure 102. Once pressure suitable for performing a leak detection test has been created in the evaporative emission space under test, a suitable procedure for obtaining a leakage measurement may be may be employed while vent valve 143 and PPS valve 20 remain closed.
The presence of leakage may be detected by sensing loss of pressure in the evaporative emission space under test, for example sensing pressure loss by means of such a pressure sensor, or switch. Such sensor, or switch, may define a switch point corresponding to a pressure suitable for performing a test. When the pressure rises to the switch point, pumping mechanism 140 may be operated in a controlled manner to increase the pressure slightly higher. The controlled manner of operation may be time-based or pulse-based. Pumping mechanism 140 may be stroked a certain number of times and then stopped, remaining stopped until the pressure sensed by the sensor drops to the switch point. For example, twenty strokes at a twenty cycle per second stroke rate would require one second. When the pressure returns to the switch point, the pumping mechanism is again stroked and stopped in the same manner as before to again slightly increase the pressure.
For a stable leak, the testing will stabilize at a condition where pumping mechanism 140 will be stroked at fairly regular intervals. The durations of these intervals between successive strokings of the pumping mechanism are indications of the effective leak size. The larger the leak, the smaller the intervals, and vice versa. Once the intervals have substantially stabilized, they may be averaged to yield a leak measurement. At the conclusion of the test, module 100 is returned to its inactive state by terminating electric current flow to coil 116. At that time lever 128 swings back to the position shown by FIG. 2. Analog and digital sensors are believed suitable for the pressure sensor, and examples of suitable devices are a Motorola 5100 Series Sensor and an MPL (MicroPneumatic Logic) 500 Series Switch.
The module 100' of FIG. 3 is like module 100 of FIG. 2, and the same reference numeral is used in both Figures to designate similar parts. Module 100' differs from module 100 in the following respects.
In module 100', no elastomeric part, corresponding to part 138 of module 100, is present on the distal end of lever arm 128a, and an elastomeric part 220, different from part 138 of module 100, is present on the distal end of lever arm 126a. As shown by FIGS. 4 and 5, the distal end of lever arm 126a comprises axially aligned, relatively shallow counterbores 221a, 221b on opposite sides. The two counterbores are substantially identical in size and shape, each being circular, except for diametrically opposite ears 221e that protrude radially beyond the otherwise nominally circular edge. A central circular through-hole 222 and two smaller circular through-holes 224 that are spaced radially outward, and equal distances from the edge, of through-hole 222 extend through the lever arm between the bottoms of the two counterbores 221a, 221b. The axes of the three through-holes pass through a common diameter of through-hole 222 that is perpendicular to the length of lever arm 126a, and that is also shared by ears 221e so that each through-hole 224 is centered in a respective ear 221e.
Part 220 is intimately joined with lever arm 126a by insert molding. Part 220 may be considered to have an imaginary axis 220a perpendicular to the length of the lever arm and to comprise a circular rim 226 that radially overlaps the edge of through-hole 222. Portions of rim 226 occupy counterbores 221a, 221b, and through-holes 224. A radially inner margin of rim 226 occupies an annular volume that forms a radially outer region of through-hole 222.
At its center, part 220 comprises radially inwardly directed formations 228 that merge at a central hub. The illustrated embodiment comprises four such formations that are separated circumferentially by radial slots centered 90° apart about axis 220a. The hub includes two substantially identical snubbers 230 that project in opposite axial directions away from the hub along axis 220a. Each snubber terminates in a rounded distal end. At each of four locations where rim 226 overlies an end of a through-hole 224, part 220 further comprises a rounded dome forming a bumper 232. Bumpers 232 are substantially identical in size and shape. Each such bumper protrudes axially a certain distance out of its respective counterbore ear 221e. FIG. 5 shows that on each side of the lever arm, the corresponding snubber 230 protrudes axially farther than the two corresponding bumpers.
A ferromagnetic cap 234 is fitted over and onto the end of core 118, which protrudes slightly farther out of bobbin 114 than in module 100. A stop 236 is disposed a distance beyond cap 234, and the distal end of lever arm 126a is disposed between them. Stop 236 is part of an integral formation that extends from a wall of enclosure 102 within interior space 103.
Pumping mechanism 140 of module 100' has a movable wall 150 that is somewhat different from its FIG. 2 counterpart. In particular, part 154 of module 100' lacks a bead corresponding to bead 196 of module 100, and its post 200 is shorter, has a rounded nose, and lacks a groove 202. Module 100' also comprises a clinch ring 162 that differs from that of module 100 by extending radially inward just far enough to capture bead 158 in groove 160. The action of spring 190 serves to bias post 200 against lever arm 126b, seating the rounded nose of the post in the concave face of a dimple 238 formed in the lever arm. This in turn biases lever 126 in the counterclockwise sense about axis 130.
FIG. 3 illustrates a maximum counterclockwise position of lever 126 set by abutment of lever arm 126a with stop 236 when electromagnet 112 is not energized. Energization of electromagnet 112 will pivot lever 126 clockwise, downstroking movable wall 150 in the process. The maximum clockwise limit of pivotal motion is set by abutment of lever arm 126a with cap 234. Hence the stroke of movable wall 150 of pumping mechanism 140 is set by the spacing distance between stop 236 and cap 234, rather than by stops built into the pumping mechanism and housing in module 100.
While elastomeric part 138 has been omitted from lever arm 128a in module 100', it, or an alternative form, could be included, depending at least to some extent on the loudness of impacting noise of lever arm 128a with cap 234 when electromagnet 112 is first energized to operate valve 143 closed. Part 220 is believed to provide certain improvements in attenuation of both impact force and audible noise. When lever 126 rocks back and forth, it is snubbers 230 that initially abut cap 234 and stop 236. When the rounded distal end of a snubber 230 hits, it is believed that the central portion of part 220 begins to deform and become effective to commence decelerating the lever. By the time that a bumper 232 hits, the lever is believed traveling at a speed noticeably less than would otherwise be the case were the corresponding snubber absent. Module 100' is operated in the same manner as module 100 during an evaporative emission space leak test.
The module 100" of FIG. 6 is like module 100' of FIG. 3, and the same reference numeral is used in both Figures to designate similar parts. Module 100" differs from module 100' in the following respects.
Module 100" includes an adjustment mechanism for adjusting the stroke of movable wall 150 of pumping mechanism 140. The adjustment mechanism comprises an eccentric cam 240 that replaces stop 236. Eccentric cam 240 is disposed on a shaft that is mounted for turning about an axis 242. Eccentric cam 240 comprises a surface that is eccentric about axis 242 and that is disposed spaced from cap 234 in confrontation of lever arm 126a. The shaft that contains eccentric cam 240 comprises a tool engagement surface, a hex socket for example, that can be engaged and rotated by a suitable adjustment tool to similarly rotate eccentric cam 240 about axis 242 to a position where the portion of the eccentric surface that faces cap 234 is set to a desired spacing distance from the cap to produce a desired stroke for movable wall 150 when pumping mechanism is operated by electromagnet 112 acting on lever arm 126.
It is to be understood that because the invention may be practiced in various forms within the scope of the appended claims, certain specific words and phrases that may be used to describe a particular exemplary embodiment of the invention are not intended to necessarily limit the scope of the invention solely on account of such use. | A module for an on-board evaporative emission leak detection system that detects leakage from an evaporative emission space of an automotive vehicle fuel system, and corresponding method that calibrates a leak detection module pump to set a desired stroke of a moveable wall in the pump of such evaporative emission leak detection system. A pump disposed within interior space of the module has an inlet in communication with the interior space and an outlet that communicates through a flow passage with the evaporative emission space. A vent valve within the interior space is selectively operable to a first state that vents the flow passage to the interior space of the module, thereby venting the evaporative emission space to atmosphere, and to a second state that does not vent the flow passage to the interior space. An electromechanical actuator within the interior space operates the pump and the vent valve by respective magnetically responsive levers. An eccentric cam for calibrating a lever is disposed for abutment by an arm of the lever and turned to a position to secure a desired relationship between the pump and actuator. | 5 |
RELATED INFORMATION
[0001] This application is a continuation of co-pending application Ser. No. 10/702,834 filed on Nov. 5, 2003, which claims priority to Australian Provisional Application No. 2002952691 filed on Nov. 15, 2002. The priority of this prior application is expressly claimed, and the disclosure of the provisional application is hereby incorporated by reference in its entirety.
FIELD OF THE INVENTION
[0002] The present invention relates generally to counterpulsation heart assist devices, systems and methods and, more particularly, to heart assist devices utilising aortic deformation and/or aortic resection.
BACKGROUND OF THE INVENTION
[0003] The concept of providing counter-pulsation support for the failing heart has been known since the pioneering work of Kantrowitz. Counter-pulsation causes displacement of a volume of a patient's blood in the patient's aorta while the patient's heart is dilating in diastole and after the aortic valve has closed. This assists to move blood around the patient's peripheral vasculature as well as into the coronary arteries. The timed volume displacement in the aorta on the blood within the aorta just in advance of systolic ejection of blood from the heart reduces the afterload on the heart, by causing a transient low pressure above the aortic valve.
[0004] It is known from the use of counter-pulsation in Intra-Aortic Blood Pumps (IABPs) that counter-pulsation can provide short term support for the failing heart. These devices require a balloon to be inserted percutaneously into the descending aorta. The balloon is inflated and deflated in counter-pulsation with the heart by the transmission of a gas, usually helium, between the balloon and a bedside console. These devices suffer from the problem that there is a high risk of thrombo-embolism if the balloon remains in the vasculature for a prolonged period, which can lead to ischemic leg complications.
[0005] There have been a number of attempts to provide counter-pulsation support for the failing heart by applying counter-pulsation pressure to the outside of the aorta. These proposals are contained in the following patent specifications:
[0000] PCT 99/04833 USA 4,014,318 USA 4,583,523 USA 4,979,936 USA 6,030,336 USA 6,045,496
A similar arrangement is described by Furman, New York Journal of Medicine, Aug. 1, 1970, pp 1964-1969. In all of these arrangements means are provided to surround, or at least substantially surround, the aorta and to apply a squeezing pressure substantially uniformly around the circumference of the aorta. The present inventors have found that there are substantial advantages if the counter-pulsation pressure is applied to only a part of the circumference of the aorta.
[0006] It is also known to resect a part of the aorta for the purpose of inserting a patch or other graft into the aorta and to cause such patch or graft to counterpulsate. Such a system is described in the following patent specifications:
[0000]
PCT
01/13974
USA
4,630,597
[0007] The device described in these specifications is for insertion into the descending aorta which is straight. There is no suggestion of how to deal with the more complex issues that arise in placing the device into the ascending aorta which is curved along its length.
OBJECT OF THE INVENTION
[0008] It would be desirable to have a heart assist device, which may or may not be blood contacting, that could provide assistance to the heart function with reduced risk to the patient and/or of device malfunction than prior art devices.
SUMMARY OF THE INVENTION
[0009] In one aspect, the present invention provides a device for assisting the functioning of the heart of a patient, the device including:
[0010] an aortic compression means adapted, when actuated, to compress an aorta; and
[0011] motive means to periodically actuate, and de-actuate, the aortic compression means in counter-pulsation with the patient's heart rhythm,
[0012] wherein the aortic compression means is adapted to compress only a portion of the circumference of the aorta.
[0013] Preferably, the aortic compression means is adapted to compress less than half of the circumference of the aorta.
[0014] In one form, the aortic compression means is a mechanical device driven, upon actuation, into compressive contact with the exterior of the aorta. In another form, the aortic compression means includes a flexible membrane, which may be elastic or inelastic, driven, upon inflation, into compressive contact with the exterior of the aorta.
[0015] The aortic compression means is preferably adapted to compress only a portion of the circumference of the ascending aorta, most preferably only the radially outer side of the ascending aorta.
[0016] In a second aspect, the present invention provides, in a heart assist device of the type which induces counter-pulsation of an artery in the vasculature of a patient, the improvement comprising the application of a counter-pulsation pressure to the exterior of the artery such that the artery is caused to flex along a continuous line which increases in length as the counterpulsation pressure applied to the artery increases.
[0017] The line preferably has the shape of a conic section.
[0018] In a third aspect, the present invention provides, in a heart assist device of the type which induces counterpulsation of an artery in the vasculature of a patient, the improvement comprising the application of a counterpulsation pressure to the exterior of the artery such that the artery is caused to compress substantially without stretching or bunching.
[0019] In a fourth aspect, the present invention provides, in a heart assist device which includes aorta deformation means to apply a counter-pulsation pressure to the ascending aorta of a patient, characterised in that the aorta deformation means applies a deforming force to the outside of the radially outer side of the curvature in the ascending aorta and that the aorta deformation means induces in the aorta a smoothly curved ovate depression as it moves to a position of maximum deformation of the aorta.
[0020] In a fifth aspect, the present invention provides, in a heart assist device which includes aorta deformation means to apply a counter-pulsation pressure to the descending aorta of a patient, characterised in that the aorta deformation means applies a deforming force to the outside of the descending aorta and that the aorta deformation means induces in the aorta a smoothly curved circular depression as it moves to a position of maximum deformation of the aorta.
[0021] In a sixth aspect, the present invention provides, in a heart assist device including artery deformation means adapted to periodically apply a deforming force to a curved artery in a direction substantially normal to a tangent to the radially outer surface of the longitudinal curve in the artery, the deforming force being such that the artery is progressively deformed along a line which lies in a plane running through the artery, the plane moving radially inwardly through the artery as the deformation increases.
[0022] In a seventh aspect, the present invention provides, in a counter-pulsation type heart assist device adapted for insertion into the wall of the ascending aorta of a patient, the device including an inflatable balloon extending around less than one half of the circumference of the aorta and means to inflate the balloon in counter-pulsation with the heart of a patient into which the device has been inserted, the balloon having a substantially inelastic outer layer and an inner layer with a shape which is, when the balloon is deflated, smoothly curved and facing directly inwardly into the lumen of the ascending aorta of the patient into which the device has been inserted. Alternatively the device may be applied to the outside of the wall of the aorta.
[0023] In an eighth aspect, the present invention provides, in a heart assist device adapted to apply a counter-pulsation force to a patch inserted into at least the radially outer arc of the ascending aorta the force being applied to the radially outer arc of the aorta to cause the wall or the patch to invaginate, the device being characterised in that it includes deformation means for the application of the pressure to the wall or patch which deformation means has, when the wall or patch is fully invaginated, a shape which is substantially a mirror image of the section of the wall or patch which has been invaginated before it was so invaginated. Alternatively the device may be applied to the outside of the wall of the aorta.
[0024] The above embodiment is designed to apply a compressive force to the artery so as to cause the blood therein to be displaced while causing the minimum trauma to the vessel. In preferred embodiments of the invention the compression of the ascending aorta is induced in a way which reduces the enclosed volume of the aorta while not unduly stretching or bunching the wall of the aorta.
[0025] The deformation of the artery may be induced by a balloon or by a rigid object. In either case the object inducing the deformation shall be so shaped that the desired form of deformation of the artery is achieved. In the case of a balloon, the balloon should be so shaped that as it is inflated it will take on a shape similar to that which is desired to be achieved in the artery. It must also be so placed on the artery that the desired smoothly flexing and smoothly shaped deformation is achieved. In the case of a rigid object the object should initially be of an appropriate shape to induce the desired deformation of the artery as it is advanced towards the artery either along a linear path or an arcuate one. Preferably, the deforming object will be moved into the artery in a direction which is radial of the artery and either at right angles to its axis, if it is straight, or at right angles to a tangent to the radially outer side of the artery, if it is curved.
[0026] Preferably, the deformation of the vessel does not extend around more than 180 degrees of the circumference of the vessel, more preferably no more than 160 degrees and even more preferably not more than 140 degrees and most preferably between 100 and 140 degrees. The cuff or balloon may extend further around the aorta than the preferred amount, however, the active deformation of the aorta preferably only extends around an arc of the aorta within the above limits. The desire of this design preference is to avoid the inside surface of the deformed vessel touching the inside surface of the vessel diametrically opposite the deformation.
[0027] In preferred embodiments the deformational force will be applied directly to the arterial wall. However, if desired a layer of any suitable material may be placed between the deformational member and the wall. In an alternative embodiment of the invention a section of the arterial wall may be resected and a patch applied which substantially replicates the shape of the native artery and the deformational force applied to the outside surface of that patch. In this embodiment of the invention the patch is applied to the radially outer arc of the ascending aorta and preferably has a shape similar to the section of the ascending aorta which has been removed.
[0028] The heart assist device of the present invention allows, at least in preferred embodiments, partial unloading of the heart and augmenting of the cardiac output of the heart.
[0029] After use, if the heart has recovered, the device can be left in situ, in an inactive state, until needed again. The device can also be used to administer on-demand, spaced-apart sessions of counterpulsation for treatment or relief from chronic myocardial ischemia and/or heart failure.
[0030] In a preferred form of the invention, the device is adapted for attachment to the ascending aorta. An upper mid-line sternotomy provides surgical access to the ascending aorta. Alternatively, a thoracotomy may be used to place the device on the descending aorta.
[0031] The motive means referred to above can be any means that is capable of cyclically introducing fluid, and withdrawing fluid, from an inflatable bladder, balloon or cuff. The motive means can include or be associated with means for detecting speed and completeness of the filling and emptying, and for monitoring the delivered fluid pressure. The motive means can also act to record the ECG, having electrodes positioned on the housing or as separate wires attached to body tissues.
[0032] In a further aspect, the present invention provides a method for improving cardiac performance in a subject, the method including the steps of:
[0033] implanting a device in accordance with any one of the preceding aspects of the invention fully within the thoracic cavity of a subject;
[0034] actuating the motive means to periodically introduce the fluid into the space in synchrony with the diastolic period to reduce the interior volume of the aorta; and
[0035] alternating the period of actuation with periods of deactivation of the motive means to periodically withdraw the fluid from the space in synchrony with the commencement of the systolic period, thereby allowing the portion of the aorta adjacent the device to return to normal interior volume.
[0036] The method may include the step of resecting a portion of the ascending aorta in the shape of a toroidal truncate and sealingly attaching the periphery of the device to the periphery of the opening aorta.
[0037] In another aspect, the present invention provides a device for assisting the functioning of the heart of a patient, the device including:
[0038] a patch device sealingly attachable to the ascending aorta;
[0039] a flexible membrane sealingly attached to at least part of the interior of the patch device and defining an inflatable space adjacent the interior of the patch device; and
[0040] motive means to periodically introduce into, and withdraw from, the space a fluid, in counter-pulsation with the patient's heart rhythm.
[0041] The patch device is preferably attachable to the radially outer side of the ascending aorta. In one form, the patch device is attachable to the periphery of an opening in the ascending aorta formed by resecting a portion of the aorta. The membrane has a shape substantially replicating that of the interior surface of the resected portion of the aorta. The flexible membrane preferably also substantially replicates the shape of the interior of the patch device when the fluid is withdrawn from the space. It is believed that this design feature will reduce the incidence of thrombo-embolism by presenting, when deflated, a blood flow path without regions that would cause sluggish blood flow. The patch device is preferably in the shape of a truncated portion of a torus. The aorta is preferably resected along a line on the radially outer side, or passing through, the diameter of the mid point cross section of the aorta. The membrane, when the fluid is introduced into the space, is preferably expanded towards, but not abutting, the adjacent interior wall of the aorta.
[0042] In another form, the patch device is attachable to the ends of the aorta formed by removing a length of the aorta. The patch device preferably includes a truncated substantially toroidal portion with an externally facing hump that forms the inflatable space. The membrane is preferably attached to the patch device about the periphery of the hump. The surface of the membrane remote the space preferably has a shape, when the fluid is withdrawn from the space, substantially replicating that of the interior surface of the removed portion of the aorta. The flexible membrane preferably also substantially replicates the shape of the interior of the hump when the fluid is withdrawn from the space. The hump is preferably disposed external to a line on the radially outer side, or passing through, the diameter of the mid point cross section of the aorta. The membrane, when the fluid is introduced into the space, is preferably expanded close to, but not abutting, the adjacent interior wall of the aorta.
BRIEF DESCRIPTION OF THE DRAWINGS
[0043] Preferred embodiments of the invention will now be described, by way of examples only, with reference to the accompanying drawings in which:
[0044] FIG. 1 is a cross sectional ventral view of the aorta of a patient with a first embodiment of a device for assisting the functioning of a heart;
[0045] FIG. 2 is a schematic lateral view of the device shown in FIG. 1 ;
[0046] FIG. 3 is a ventral view of the aorta of a patient showing a series of planes through the aorta in which lines of flexure of the aortic wall will lie during application of a deforming force to the aorta;
[0047] FIG. 4 is cross sectional view along line 4 - 4 through the aorta of FIG. 3 showing a sequence of shapes assumed by the aortic wall as it is deformed;
[0048] FIG. 5 is a part longitudinal cross-sectional view through the aorta of FIG. 3 along line 5 - 5 of FIG. 6 , showing a sequence of shapes assumed by the aortic wall as it is deformed;
[0049] FIG. 6 is a lateral view from the right side of the aorta of FIG. 3 , showing a sequence of lines of flexure as the aorta is deformed;
[0050] FIG. 7 is a schematic side view of an ascending aorta showing a resection line;
[0051] FIG. 8 is a schematic side view of the aorta shown in FIG. 7 after resection of a portion of the aorta;
[0052] FIG. 9 is a schematic side view of another embodiment of a device for assisting the functioning of the heart with a withdrawn internal membrane;
[0053] FIG. 10 is a schematic side view of the device shown in FIG. 9 with an expanded membrane;
[0054] FIG. 11 is a schematic side view of the aorta shown in FIG. 8 after surgical attachment of the device shown in FIGS. 9 and 10 with the membrane shown in withdrawn and expanded positions;
[0055] FIG. 12 is a schematic cross sectional end view of the aorta and device shown in FIG. 11 ;
[0056] FIG. 13 is a schematic cross sectional view of an aorta of reduced size with a resected portion;
[0057] FIG. 14 is a cross sectional end view of the aorta of FIGS. 13 and 15 after surgical attachment of a further embodiment of device for assisting in the functioning of the heart;
[0058] FIG. 15 is a schematic front view of the resected aorta shown in FIG. 13 ;
[0059] FIG. 16 is a schematic front view of the aorta and device shown in FIG. 15 ;
[0060] FIG. 17 is a schematic side view of an ascending aorta showing an alternatively positioned resection line;
[0061] FIG. 18 is a cross sectional ventral view of the aorta of a patient with a further embodiment of a device for assisting the functioning of a heart.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0062] FIG. 1 is a schematic side view of an ascending aorta 10 and a heart assist device 16 in accordance with an embodiment of the invention. The device 16 has a relatively inelastic, preferably plastic, shell 17 and a flexible membrane 18 sealingly attached to the periphery of the shell 17 . The membrane 18 defines an inflatable space 19 between it and the interior of the shell 17 . The shell 17 also has an inlet/outlet port 20 which is adapted for connection to a motive means that can periodically introduce, and withdraw, a fluid (eg. a gas such as helium or a liquid such as a saline solution or an oil) to and from the space 19 in counter-pulsation with the patient's heart rhythm. The membrane 18 has a shape which is, when deflated, smoothly curved and facing directly inwardly towards the lumen of the ascending aorta 10 .
[0063] A relatively inelastic wrap 21 is used to hold the device 16 in the position shown on the radially outer side of the ascending aorta 10 .
[0064] The solid line 18 illustrates the position of the membrane 18 relative to the shell 17 when fluid has been withdrawn from the space 19 and the membrane 18 has been retracted. In this position the radially outer external side wall 10 e of the aorta 10 is in its normal or deflated position allowing maximum blood flow there through.
[0065] The phantom line 18 illustrates the position of the membrane 18 relative to the shell 17 after fluid has been introduced into the space 19 and the membrane 18 has been expanded. When the membrane 18 is expanded in this way, the aorta external wall 10 e is compressed and inwardly deformed until it is close to, but not abutting, the opposite interior wall of the aorta 10 r.
[0066] The membrane 18 is sized and positioned to compress only a portion of the circumference of the radially outer side of the ascending aorta 10 . More particularly, the membrane 18 compresses only about 140 degrees of the circumference of the aorta 10 .
[0067] FIGS. 3 to 6 show, in various orientations and views, the shape the external wall 10 e of the ascending aorta 10 assumes from initial deformation (line A) through to maximum deformation (line E). The lines A to E show the exterior of the aorta 10 flexing along a continuous line, that preferably has the shape of a conic section, which increases in length as the counter pulsation pressure applied to the artery increases. An advantage of flexing the aorta in this manner is that it is caused to compress substantially without stretching, which reduces the likelihood of damage. Also the line of flexure is constantly moving so that one line of the aorta 10 is not being constantly exposed to flexural movement. Put another way, the exterior of the aorta is deformed to induce a smoothly curved ovate depression as it moves towards a position of maximum deformation (line E) of the aorta 10 . In an alternative embodiment, a smoothly curved circular depression can be formed in the aorta.
[0068] The lines A to E also show how the artery is progressively deformed along a line which lies in a plane running through the artery 10 , that plane moving radially inwardly through the artery as the deformation increases.
[0069] The deformation described above can be caused to occur in many other different ways. For example, in another embodiment, deformation can be caused by a patch device inserted into the radially outer arc of the ascending aorta. In such an embodiment, the device includes a means for applying pressure to the wall or patch which, when the wall or patch is fully invaginated, forms a shape which is a mirror image of the section of the wall or patch which as been invaginated before it was so invaginated.
[0070] Another embodiment of a device for assisting the functioning of a heart according to the present invention will now be described in relation to FIGS. 7 to 12 . Like reference numerals will be used to indicate like features used in describing to the preceding embodiment.
[0071] FIG. 7 is a schematic side view of a portion of ascending aorta 10 . Line 12 is a resection line passing through the diameter of the midpoint cross section of the aorta 10 (see also FIG. 12 ).
[0072] FIG. 8 is a schematic view of the resected aorta 10 r after cutting the aorta 10 along the resection line 12 and removal of a resected portion 14 .
[0073] FIG. 9 is a schematic side view of a heart assist device 16 in accordance with another embodiment of the invention. The device 16 has a relatively inelastic, preferably plastic, shell 17 and a flexible membrane 18 sealingly attached to the periphery of the shell 17 . The membrane 18 defines an inflatable space 19 between it and the interior of the shell 17 . The shell 17 also has an inlet/outlet port 20 which is adapted for connection to a motive means that can periodically introduce, and withdraw, a fluid (eg. a gas such as helium or a liquid such as a saline solution or an oil) to and from the space 19 in counter-pulsation with the patient's heart rhythm.
[0074] FIG. 9 illustrates the position of the membrane 18 relative to the shell 17 when fluid has been withdrawn from the space 19 and the membrane 18 has been retracted ( 18 r in FIGS. 11 and 12 ). FIG. 10 illustrates the position of the membrane 18 relative to the shell 17 after fluid has been introduced into the space 19 and the membrane 18 has been expanded ( 18 e in FIGS. 11 and 12 ). When the membrane 18 is expanded it is close to, but not abutting, the opposite interior wall of the aorta 10 r.
[0075] The shell 17 has a peripheral edge of common shape to the opening formed in the aorta 10 r after removal of the resected portion 14 . This permits the device 16 to be attached to the resected aorta 10 r by stitching between the periphery of the shell 17 and the periphery of the opening in the resected aorta 10 r , as indicated by stitches 22 in FIG. 11 .
[0076] The motive means (not shown) include a fluid reservoir and a pump means adapted to pump the fluid from, the fluid reservoir to the port 20 , and thus the space 19 between the interior of the shell 17 and the flexible membrane 18 , and then withdrawn same, to expand ( 18 e ) and retract ( 18 r ) the membrane 18 as indicated in FIGS. 5 and 6 . Suitable implantable fluid reservoirs and pump means are disclosed in the applicant's international PCT patent application Nos. PCT/AU00/00654 and PCT/AU02/00974, which are hereby incorporated by cross reference.
[0077] More particularly, in use, the motive means is periodically actuated to introduce fluid into the space 19 in synchrony with the diastole period to reduce the interior volume of the aorta 10 r and thereby provide additional pumping of the blood in the aorta 10 r to assist the functioning of the heart. This introduction of fluid is alternated with periodic withdrawal of the fluid from the space 19 to allow the aorta 10 r to return to its normal interior volume. As described above, the introduction of fluid expands the membrane 18 to be close to, but not abutting, the opposite interior wall of the aorta 10 r . This maximises pumping volume without risk of the membrane 18 contacting and damaging the aorta 10 r.
[0078] It will be appreciated that the heart assist device 16 includes a component, namely the membrane 18 , which is blood contacting. However, the previously described disadvantages of blood contacting are minimised by the present invention as when the fluid is withdrawn from the space 19 the membrane 18 is drawn into a shape substantially replicating the original (now resected) aorta wall. As a result, no eddies or pockets are introduced into the blood flow path that may disrupt blood flow when the device 16 is not activated thereby substantially reducing clot risk.
[0079] Also, if the heart recovers the device 16 can be deactivated with the membrane 18 in the retracted position (see FIGS. 9 and 18 r in FIGS. 11 and 12 ) allowing natural blood flow there through. In this connection, it should also be noted that heart assist devices have been proposed that function in parallel to the aorta and which receive the full diverted flow of blood originally intended for to the aorta. These devices can not be deactivated unlike the device according to the present invention.
[0080] Further, by installing the device 16 in a position vacated by the resected portion 14 of the aorta 10 it achieves a relatively high pumping volume for a relatively low device volume.
[0081] The flexible membrane 18 is preferably manufactured from a polyurethane or a polyurethane-polysiloxane block co-polymer material or other similar material, which encourages ingrowth of the passing blood cells and can eventually create a new “natural” cell lining.
[0082] The device according to the present invention is also particularly advantageous for use in patients whose aortas have become diseased as the device can be implanted in place of the resected damaged section.
[0083] A further embodiment of the device for assisting the functioning of a heart according to the present invention will now be described in relation to FIGS. 13 to 16 . Like reference numerals will be used to indicate like features used in describing to the preceding embodiment. This embodiment is particularly suitable for use in patients having a naturally small aorta or an aorta that has shrunk through heart disease or the like.
[0084] FIG. 13 is a schematic cross sectional end view of a reduced diameter resected aorta 10 r showing resection line 12 and resected portion 14 . The periphery of the opening formed by removing the resected portion 14 is denoted 24 in FIG. 15 . FIG. 14 shows the resected aorta 10 r after its included angle {acute over (α)} has been increased to {acute over (α)} so as to open or stretch out the opening 24 in the aorta 10 r . Such stretching allows the attachment of a heart assist device 16 of a similar size to that used in a healthy aorta. In this way, the effective cross section of the aorta available for pumping by the membrane 18 can be increased. For example, from about 707 mm 2 at an original diameter of 30 mm to about 1257 mm 2 at a stretched diameter of 40 mm. This results in a corresponding increase in the pumping volume of the aorta 10 r.
[0085] FIG. 17 is a schematic side view of an ascending aorta 10 showing an alternatively positioned resection line 12 . In this form, the resection line 12 is angled towards the top of the aorta 10 to resect the upper, radially outer arc of the aorta 10 .
[0086] A further embodiment of a device for assisting the functioning of a heart according to the present invention will now be described in relation to FIG. 18 . Like reference numerals will be used to indicate like features used in describing to the preceding embodiments.
[0087] In FIG. 18 the heart assist device is a patch device 16 attachable to the ends of the aorta 10 , at stitches 22 , formed by removing a length of the aorta. The patch device 10 is in the general shape of a truncated toroid with an externally facing hump that forms the inflatable space 19 . The membrane 18 is attached to the patch device 16 about the periphery of the hump. The hump is disposed external to a line on the radially outer side, or passing through, the diameter of the mid point cross section of the aorta 10 .
[0088] The flexible membrane 18 substantially replicates the shape of the interior of the hump when the fluid is withdrawn from the space 19 . The membrane 18 , when the fluid is introduced into the space 19 , is expanded close to, but not abutting, the adjacent interior wall of the aorta, as is shown in phantom line.
[0089] Whilst the above embodiments have been described in relation to compressing the radially outer wall of the aorta, it would be appreciated by a person skilled in the art that other portions of the aorta can be deformed or other arteries can be deformed to assist in heart functions.
[0090] The heart assist devices described above are suitable for short and/or long term treatment for heart failure and/or myocardial ischemia.
[0091] It will be appreciated by persons skilled in the art that numerous variations and/or modifications may be made to the invention as shown in the specific embodiments without departing from the spirit or scope of the invention as broadly described. The present embodiments are, therefore, to be considered in all respects as illustrative and not restrictive. | The present invention relates to providing counter-pulsation heart assist by deforming the aorta. In a preferred embodiment, the deformation pressure is applied by cyclically, preferably in synchrony with the diastolic period of the heart. The deformation pressure may be applied to the outer wall of the aorta or to a patch covering a resected opening in the wall of the aorta. | 0 |
CROSS REFERENCE TO RELATED APPLICATIONS
This application is a continuation of U.S. Nonprovisional patent application Ser. No. 13/529,807 filed Aug. 23, 2012, entitled “Screen Reader with Focus-Based Speech Verbosity.”
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to software for low vision users. More specifically, it relates to a screen magnifier application that automatically adjusts speech output verbosity based on how a user arrives at an object's focus.
2. Brief Description of the Related Art
Personal computers and the Internet greatly enhanced communications and access to information from around the world. Typically, visual information is displayed upon a monitor screen and data can be added or manipulated via keystrokes upon an associated keyboard. Feedback is provided visually to the user by the monitor screen. Blind users cannot utilize the information appearing upon the monitor screen while visually impaired users may experience difficulty doing so. Accordingly, screen readers have been developed to assist blind and visually impaired users when they use a personal computer.
A screen reader is software which interprets the output of a computer as sent to a computer screen and converts it into alternative output. Typically, the alternative output is in the form of synthetic speech or Braille characters. Screen readers are particularly useful for a blind or low vision user. One such screen reader is JAWS for Windows developed and sold by Freedom Scientific, Inc., based in St. Petersburg, Fla. When installed upon a personal computer, JAWS provides access to the operating system, software applications and the Internet. JAWS includes a speech synthesizer that cooperates with the sound card in the personal computer to read aloud information appearing upon the computer monitor screen or that is derived through communicating directly with the application or operating system. Thus, JAWS provides access to a wide variety of information, education and job related applications. Additionally, JAWS includes an interface that can provide output to refreshable Braille displays. It should be noted that reference to JAWS is made as an example of a screen reader but the novel and non-obvious software media and methods claimed herein are applicable to screen readers as a whole.
In addition to screen reading, low vision individuals often require magnification of computer screen interfaces to discern text and images. Magnification systems may be built into the operating system itself or may comprise feature-rich, third-party products such as those sold under the MAGIC brand also manufactured by Freedom Scientific, Inc. Screen readers and screen magnifiers may work in conjunction so that both interoperate to provide a full array of features to the end user.
One of many useful features that screen readers provide to low-vision end users is the ability to output a description of a control on a graphic user interface. For example, as a user navigates a screen the various buttons, menus, and lists are announced to the user by speech output controlled by the screen reader software. However, the current state of the art outputs the same description regardless as to how to the user arrived at the particular control in the graphic user interface.
Speech output is a double-edged sword to the end user. When needed, it provides the necessary information for the user to understand the context and identity of the graphic user interface control. However, when it is not needed, the speech output becomes a distraction which the end user typically mutes with a keystroke. An end user that navigates about a graphic user interface may invoke the screen reader's speech output seemingly on a continual basis . . . some of the output necessary and some of the output unnecessary.
What is needed in the art is for the screen reader software to evaluate how the end user navigated to a control on the graphic user interface and automatically adjust the verbosity of the speech output to better convey an optimal amount of information to the end user.
However, in view of the art considered as a whole at the time the present invention was made, it was not obvious to those of ordinary skill in the field of this invention how the shortcomings of the prior art could be overcome.
BRIEF SUMMARY OF THE INVENTION
The long-standing but heretofore unfulfilled need for variable speech output by a screen reader based on how focus is set on a graphic user interface control is now met by a new, useful, and nonobvious invention. A screen reader software product such as JAWS includes software executable instructions stored in a computer readable medium. The computer readable medium may be optical discs such CDs and DVDs but is trending to downloadable software packages obtained by the end user online. It is also anticipated that some components or features of the present invention may operate remotely or “in the cloud” as processing, storage and other computing activities become more diffuse over high-bandwidth network environments.
Nevertheless, in one embodiment of the invention the software is installed on the computer of the end user. The end user's computer has a computer monitor that displays the graphic user interface of an operating system such as those sold under the WINDOWS brand by Microsoft Corporation out of Redmond, Wash. A graphic user interface has characters and graphics drawn on the screen at various positions, and therefore there is no purely textual representation of the graphical contents of the display.
Screen readers are often forced to employ new low-level techniques, gathering messages from the operating system and using these to build up an “off-screen model”, a representation of the display in which the required text content is stored. Operating system and application developers sometimes are able to provide alternative and accessible representations of what is being displayed on the screen through an API. Some APIs useful for screen reading software include Apple Accessibility API; AT-SPI; IAccessible2; Microsoft Active Accessibility (MSAA); Microsoft UI Automation; and Java Access Bridge. Screen readers can query the operating system or application for what is currently being displayed and receive updates when the display changes. For example, a screen reader can be told that the current focus is on a button and the button caption to be communicated to the user. This approach is considerably easier for screen readers, but fails when applications do not comply with the accessibility API. One approach is to use available operating system messages and application object models to supplement accessibility APIs.
The end user's computer will also have, or be coupled to, a speech output module which electronically translates alphanumeric data into human recognizable speech. Various applications are loaded and run through the operating system. It is important to note that the end user in this patent application refers to the low-vision user or “consumer” of the screen reader software. The end user is different from a developer user who authors software or web pages and has write access to the “source code” or instructions that determine how a program operates or how a web page is presented through a browser application.
In one embodiment of the invention, the screen reader software hooks into the event messaging of the operating system running on the computer. The operating system displays a graphic user interface having an end user operable control focusable by both keyboard and mouse input. A control is an element of the graphical user interface that displays an information arrangement changeable by the end user, such as a window or a text box. The characteristic of the control is to provide a single interaction point for the direct manipulation of a given kind of data. Controls may include buttons, check boxes, radio buttons, sliders, list boxes, spinners, drop-down lists, menus, toolbars, combo boxes, icons, tree views, grid views, links, scrollbars, text boxes, labels, tooltips, status bars, dialog boxes and the like.
The software monitors the event messaging for keyboard and mouse events setting focus on the control responsive to end user interaction with the graphic user interface wherein the screen reader automatically outputs to speech a more verbose description of the control responsive to focus set by tab keystroke and a less verbose description of the control responsive to focus set by mouse navigation. Mouse navigated focus on a control has a higher probability that the end user already knows what control he or she has focused on and therefore does not need as much information output to speech.
However, an end user that tabs between controls in a graphic user interface will likely require more information about those controls as he or she may be “hunting” for the appropriate control to manipulate. By way of example, a higher verbosity level set by a tab keystroke focus may output to speech “button . . . save file” while a lower verbosity level set by a mouse over focus may output to speech simply “save file.” Alternatively, lower verbosity levels may only include a “ding” sound or even be muted altogether.
Detecting a tab keystroke that sets focus on the control is achieved by hooking into a keyboard callback function and similarly detecting a mouse action setting focus on the control by a mouse hover event is achieved by hooking into a mouse callback function. The screen reader software may include instructions for obtaining, storing, retrieving and implementing end user preferences regarding the verbosity settings for both keyboard and mouse set control focus. This provides a greater level control to the end user and improves the productivity of the end user by not exposing him or her to excessive speech output if such information is not required by the end user.
An alternative embodiment of the invention operates substantially in the same way but distinguishes between tab keystrokes and non-tab keystrokes. Tabbing through a graphic user interface moves the focus from one control to another. Software developers and authors frequently control the tab order so that the controls are arrived at in an intuitive sequence. However, when focus is set on a control by a non-tab keystroke, it is more likely that the user had a more definitive idea of where he or she wanted to navigate. For example, in MICROSOFT WORD 2010 pressing the P key while holding down the control (CTRL) modifier will set focus on a button control to print the current document. These combinations of keys are also known as keystroke accelerators. The screen reader software according to the current invention will presume this precise keystroke sequence is indicative of the end user knowing exactly what control he or she intended to invoke. Therefore, there is little need to output a lengthy description of the print button control. It might simply output “print” or a sound or even nothing as there is a high level of confidence the end user already knows he or she has set focus on the button to print the document.
Another type of keystroke accelerator is a function key which may be used alone or in combination with modifier keys. In an embodiment of the invention a less verbose description of the control is outputted responsive to the function key setting focus on a control relative to a non-tab keystroke that consists of a single key down which is not a function key.
BRIEF DESCRIPTION OF THE DRAWINGS
For a fuller understanding of the invention, reference should be made to the following detailed description, taken in connection with the accompanying drawings, in which:
FIG. 1 is a conceptual view of a graphic user interface having a plurality of controls.
FIG. 2 is a conceptual view of a graphic user interface with focus set by a mouse pointer.
FIG. 3 is a conceptual view of a graphic user interface with focus set by a tab keystroke.
FIG. 4 is a conceptual view of a graphic user interface with focus set by an accelerator keystroke.
FIG. 5 is a conceptual view of a graphic user interface with focus set by a mouse hover event.
FIG. 6 is a diagrammatic view of an embodiment of the invention setting verbosity levels by focus events.
FIG. 7 is a diagrammatic view of another embodiment of the invention setting verbosity levels by focus events.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
An exemplary graphic user interface is denoted as a whole in FIG. 1 . The application is entitled “Generic Application” and is presented as dialog box 100 . Text box 105 contains arbitrary text 110 . Four buttons on the left side of dialog box 100 include copy text button 115 , print text button 120 , open file button 125 and save file button 130 . Hyperlink 135 is positioned below the four buttons. Below text box 105 are find button 140 , sound button 145 , zoom in button 150 , zoom out button 155 , back button 160 , stop button 165 , play button 170 , forward button 175 and settings button 180 . In FIG. 1 there are no control elements in focus.
In FIG. 2 , mouse indicia 200 hovers over copy text button 115 putting it in focus 210 as visually apparent from the change in the border of copy text button 115 . A low vision user hovering over copy text button 210 with mouse indicia 200 will likely already know which control they indicated to activate. Therefore, it is undesirable to output a lengthy description of the copy text button 115 to the end user. For the situation in FIG. 2 , the verbosity may be automatically set low by the screen reader software so that only “copy” is output to speech. Alternatively, there may be a special sound associated with the copy command which is output or possibly no output is made in this instance because of the high confidence level the end user knows what control they are focused on.
In FIG. 3 , mouse indicia 300 is not on any control but print text control button 120 has focus set 310 by a tab keystroke. Tabbing through all the controls in dialog box 100 is more indicative of an end user that requires more information output to speech so they are aware of which control upon which focus is set. In this tab-navigation example, the screen reader software is more verbose in its output compared to a mouse-based focus event. Therefore, the speech output from the tab-navigation may be “Button: Print Text.”
In FIG. 4 , end user has highlighted 440 a portion of text 110 using caret 400 . A CTRL-C keystroke combination invokes focus on a popup copy indicia 415 . In this case, the need for speech output detail is extremely low because the end user invoked a precise keystroke combination that will place highlighted text 440 onto the clipboard of the operating system. Short, non-textual audible indicia such as a ding or chime may complete the feedback loop for the end user in this situation.
In FIG. 5 , a mouse hover over link 135 changes the mouse indicia 500 to a hand cursor and sets a new focus 505 over link 135 . As the mouse navigation conveys a presumption of end user awareness the verbosity level may be adjusted downward. However, as the control is specific to a designated URL, only the URL identification (or an ALT description tag thereof) may be output to speech by the screen reader. In contradistinction, had the end user navigated to link 135 by tab keystroke a more verbose output may indicated first the type of control being a hyperlink.
FIG. 6 shows a flow chart process of an embodiment of the invention 600 which first detects an on focus event 605 through event messaging in the operating system of the computer running the screen reader application. The origin of focus 610 is determined as either a tab order 615 , a mouse over 620 or a keystroke combination 625 . It should be noted that alternative mouse and keyboard events are anticipated and included within this invention such as scrolling a mouse wheel and other input events enacted by the end user that set focus on a control.
Responsive to tab order 615 , verbosity setting A is set 630 . Text to speech (TTS) output 645 generates “Button Control . . . Copy Text.” Responsive to mouse over 620 , verbosity setting B 635 is set. TTS output 650 generates “Copy Text.” Responsive to keystroke combination 625 (e.g., CTRL-C), verbosity setting C 640 is set. TTS output 655 generates “Copied” which indicates that the text has already been copied. In this example, focus is set by tab order 615 and mouse over 620 but in keystroke 625 the function was automatically executed and no focus change effected.
In FIG. 7 , a Win32 API function called SetWindowsHookEx 705 allows installing a system-wide keyboard and/or mouse hook. Using these hooks it's possible to detect whether a keyboard or mouse event was the most recent input and act accordingly. For a keyboard event, KeyboardLLProc function 710 determines whether a tab keystroke (VK_TAB) was received. If so, it sets the verbosity for tab focus change 715 . Alternatively, if the keystroke received was not VK_TAB then the verbosity is set for an accelerator key focus change 720 which is less verbose. The next hook is then called 725 .
For a mouse event, MouseLLProc function 730 determines if the mouse event was a button event. This would activate the control, not just set focus so the next hook is called 725 . However, if the mouse event is anything other than a left mouse button down, middle mouse button down or right mouse button down then the verbosity is set for a mouse generated focus change 740 . After that, the next hook is called 725 .
As an illustrative example, the following tables show how verbosity levels may be adjusted according to how focus on a control is arrived at:
TABLE 1
Control
Button
Listbox
Hyperlink
Tab Focused
Button:
Listbox, Shipping
Hyperlink: Launch
Save File
Options, 10 items
Google Patents
Accelerator
Save File
Shipping Options,
{ding} Google
Focused
10 items
Patents
Mouse Focused
Save
Shipping
{ding}
As seen in Table 1, tab focus events output more lengthy (verbose) speech compared to accelerator keystroke focus events. Mouse focus event still produce even more terse output which may include only a sound (“ding”) when hovering over a hyperlink. In all cases where verbosity is reduced, it is anticipated that an embodiment of the invention permits the end user to direct the screen reader to output a more verbose description upon demand.
Functionally, the screen reader software has a host of information to output to speech regarding a control. Setting the verbosity may involve selectively outputting or suppressing the control type, control identity, control state, control item count and the like. An alternative embodiment of the invention may also reduce verbosity with string handling techniques such as outputting only the first word in a control description such as that shown in Table 1 for mouse focused listbox output which trimmed the string “Shipping Options” down to simply “Shipping” using string handling functions to find the integer location of the first space in the description and stopping the speech output at that location.
Hardware and Software Infrastructure Examples
The present invention may be embodied on various computing platforms that perform actions responsive to software-based instructions. The following provides an antecedent basis for the information technology that may be utilized to enable the invention.
The computer readable medium described in the claims below may be a computer readable signal medium or a computer readable storage medium. A computer readable storage medium may be, for example, but not limited to, an electronic, magnetic, optical, electromagnetic, infrared, or semiconductor system, apparatus, or device, or any suitable combination of the foregoing. More specific examples (a non-exhaustive list) of the computer readable storage medium would include the following: an electrical connection having one or more wires, a portable computer diskette, a hard disk, a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or Flash memory), an optical fiber, a portable compact disc read-only memory (CD-ROM), an optical storage device, a magnetic storage device, or any suitable combination of the foregoing. In the context of this document, a computer readable storage medium may be any tangible medium that can contain, or store a program for use by or in connection with an instruction execution system, apparatus, or device.
A computer readable signal medium may include a propagated data signal with computer readable program code embodied therein, for example, in baseband or as part of a carrier wave. Such a propagated signal may take any of a variety of forms, including, but not limited to, electro-magnetic, optical, or any suitable combination thereof. A computer readable signal medium may be any computer readable medium that is not a computer readable storage medium and that can communicate, propagate, or transport a program for use by or in connection with an instruction execution system, apparatus, or device.
Program code embodied on a computer readable medium may be transmitted using any appropriate medium, including but not limited to wireless, wire-line, optical fiber cable, radio frequency, etc., or any suitable combination of the foregoing. Computer program code for carrying out operations for aspects of the present invention may be written in any combination of one or more programming languages, including an object oriented programming language such as Java, C#, C++ or the like and conventional procedural programming languages, such as the “C” programming language or similar programming languages.
Aspects of the present invention are described below with reference to flowchart illustrations and/or block diagrams of methods, apparatus (systems) and computer program products according to embodiments of the invention. It will be understood that each block of the flowchart illustrations and/or block diagrams, and combinations of blocks in the flowchart illustrations and/or block diagrams, can be implemented by computer program instructions. These computer program instructions may be provided to a processor of a general purpose computer, special purpose computer, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, create means for implementing the functions/acts specified in the flowchart and/or block diagram block or blocks.
These computer program instructions may also be stored in a computer readable medium that can direct a computer, other programmable data processing apparatus, or other devices to function in a particular manner, such that the instructions stored in the computer readable medium produce an article of manufacture including instructions which implement the function/act specified in the flowchart and/or block diagram block or blocks.
The computer program instructions may also be loaded onto a computer, other programmable data processing apparatus, or other devices to cause a series of operational steps to be performed on the computer, other programmable apparatus or other devices to produce a computer implemented process such that the instructions which execute on the computer or other programmable apparatus provide processes for implementing the functions/acts specified in the flowchart and/or block diagram block or blocks.
GLOSSARY OF TERMS
Audible Cue is an unobtrusive sound that may be played in sequence or concurrently with text-to-speech or Braille to indicate the web page being output has been modified by a customization rule.
Braille is a method that is widely used by people who are visually impaired to read and write. A Braille display is an electronic, pin-actuated, computer controlled peripheral that outputs Braille to a visually impaired user. Examples include the FOCUS 40 and FOCUS 80 Braille displays designed, manufactured and sold by Freedom Scientific, Inc.
Dialog Box is typically a separate window generated in a software application that presents information to an end user and more often, presents options for an end user to select. A modal dialog box restricts activity to that box and does not permit other interaction in the software application until the modal dialog box is closed. For the purposes of this patent specification, the dialog box may be presented on the graphic user interface but will also be identified by non-visual output via the screen reader to convey selection options to the end user.
End user: is the person controlling the screen reader software. For the purposes of this patent specification, user and end user are used interchangeable. User and end user should not be confused with a developer or author . . . one that programs software code or a website designer or content generator that authors a web page.
Focus is the state of a control in a graphic user interface indicating it is targeted for end user interaction. This may be achieved by keystrokes and/or mouse navigation over the location of the control. In most environments, setting focus visually changes the appearance of the control by creating a slight variation in background of the control and/or its border. Non-visual feedback may be tactile and audio-based. Once a control is in focus, further user interaction by mouse or keyboard manipulates the control. For example, a button in focus may be activated by depressing the enter key or by a left mouse down click. A drop-down list in focus may be further manipulated by depressing the up and down arrow keys on the keyboard or the scroll wheel on a mouse. However, if focus is not on these controls, the downstream user interaction will not manipulate the controls as intended. Therefore, it is important for the end user to be aware that focus exists on the proper control prior to interacting with it.
Hooks are points in the system message-handling mechanism where an application can install a subroutine to monitor the message traffic in the system and process certain types of messages before they reach the target window procedure.
KBDLLHOOKSTRUCT structure contains information about a low-level keyboard input event. It is specific to the MICROSOFT WINDOWS operating system.
Keyboard accelerator (or, simply, accelerator) is a keystroke or combination of keystrokes that generates a WM_COMMAND or WM_SYSCOMMAND message for an application. It is specific to the MICROSOFT WINDOWS operating system.
KeyboardProc callback function is an application-defined or library-defined callback function used with the SetWindowsHookEx function. The system calls this function whenever an application calls the GetMessage or PeekMessage function and there is a keyboard message (WM_KEYUP or WM_KEYDOWN) to be processed. It is specific to the MICROSOFT WINDOWS operating system.
Keystroke Commands are one or more keystrokes typically made on a QUERTY-type keyboard for executing a procedure or function on the screen reader software. Keystroke commands are particularly useful for screen reader manipulation as the visually impaired end user can navigate a keyboard far more reliably than setting a coordinate-based pointing device indicia over a specific graphic user interface control.
LowLevelMouseProc callback function is an application-defined or library-defined callback function used with the SetWindowsHookEx function. The system calls this function every time a new mouse input event is about to be posted into a thread input queue. It is specific to the MICROSOFT WINDOWS operating system.
Modifier keys are special keys that modify the normal action of another key, when the two are pressed in combination. For example, <Alt>+<F4> in MICROSOFT WINDOWS will close the program in an active window. The most widely used modifier keys include the Control key, Shift key and the Alt key.
Non-textual Sound Indicia means any sound that may have an arbitrary meaning By way of non-limiting examples, these sounds may include alarm, alert, beeper, bell, buzzer, chime, foghorn, horn, siren, slide whistle, sonar, whistle, wind chimes, ambiance, bang, beep, blip, bloop, boing, boop, button, buzz, cartoon noises, chirp, clang, clank, clap, click, clink, crack, creak, crunch, cut, ding, Doppler, drop, electricity, fall, fanfare, flap, growl, hiss, howl, hum, knock, leak, metal, Morse code, noise, pop, rattle, ring, rip, roar, robot, rustle, scrape, scratch, screech, shuffle, sizzle, skid, snap, snip, sparks, splash, splat, spring, squeak, squeal, squish, static, steam, stone, swing, tap, tear, thud, tick, tink, underwater, warble, whine, whoosh, and wood.
Non-Visual Medium means a communication methodology that does not rely on visual acuity which would be required for computer screens and monitors. Non-visual mediums include tactile devices such as Braille displays and audio devices such as text-to-speech synthesizers and/or sound cues.
Screen Magnifier is a software application that interfaces with a computer's graphical output to present enlarged screen content. It is a type of assistive technology suitable for visually impaired people with some functional vision. Visually impaired individuals with little or no functional vision usually use a screen reader (see below). Screen magnifiers may also be used in conjunction with screen readers to both enlarge screen content and output said content to Braille or speech.
Screen Reader is a software application that attempts to identify and interpret what is being displayed on the screen (or, more specifically, sent to standard output, whether a video monitor is present or not). This interpretation is then re-presented to the user with text-to-speech, sound icons, or a Braille display device.
SetWindowsHookEx function is an application-defined hook procedure into a hook chain. A developer would install a hook procedure to monitor the system for certain types of events. These events are associated either with a specific thread or with all threads in the same desktop as the calling thread. It is specific to the MICROSOFT WINDOWS operating system.
Storage Medium is generally a hard drive or memory device whether local or remote to save and retrieve data and settings.
Tab Order: When an end user tabs from field to field in a form the tab order is the order the fields appear in the HTML code. However, sometimes the HTML author may want the tab order to flow a little differently. In that case, he/she can number the fields using the attribute TAB INDEX. The tabs then flow in order from lowest to highest.
Web Page is a document or information resource that is suitable for the World Wide Web and can be loaded and accessed via a web browser and displayed on a monitor or mobile device. This information is usually in HTML or XHTML format, and may provide navigation to other web pages via hypertext links.
Web Page Element: A single feature of web page content, e.g., link, heading, frame, etc. Elements may contain other elements, e.g., frames may contain links.
The advantages set forth above, and those made apparent from the foregoing description, are efficiently attained. Since certain changes may be made in the above construction without departing from the scope of the invention, it is intended that all matters contained in the foregoing description or shown in the accompanying drawings shall be interpreted as illustrative and not in a limiting sense. | The amount of speech output to a blind or low-vision user using a screen reader application is automatically adjusted based on how the user navigates to a control in a graphic user interface. Navigation by mouse presumes the user has greater knowledge of the identity of the control than navigation by tab keystroke which is more indicative of a user searching for a control. In addition, accelerator keystrokes indicate a higher level of specificity to set focus on a control and thus less verbosity is required to sufficiently inform the screen reader user. | 6 |
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a continuation of International Application No. PCT/SE00/01647 filed Aug. 28, 2000, which designated the United States and was published in English under PCT Article 21.
FIELD OF THE INVENTION
[0002] The present invention relates to a board machine and method for manufacturing a multilayer cardboard web with a printable surface layer, comprising a wet section and a press section, which wet section includes a first forming unit for forming a first layer, which first forming unit has at least one forming wire, running in an extended loop up to the press section to form a pick-up point for the multilayer cardboard web, and one or more further forming units for forming one or more further layers and for couching the same with said first layer on said extended forming wire of the first forming unit to form the multilayer cardboard web, which press section includes at least one double-felted press, having an upper press element, a lower press element in the shape of a press roll, which press elements create a press nip with each other, an upper press felt, running in a loop around a plurality of guide rolls and a pick-up roll, arranged at said pick-up point for transferring the multilayer cardboard web to the upper press felt, and a lower press felt, running in a loop around a plurality of guide rolls.
[0003] As used herein, the expression “the 0 line of the press” is defined, for a roll press, as the tangent perpendicular to a straight line intersecting the centers of the press rolls and, for a shoe press, as the tangent of the transition from the concave curvature to the convex curvature of the shoe at the exit of the press nip.
BACKGROUND OF THE INVENTION
[0004] One side of a multilayer cardboard web is often used for printing. This side, denoted the front side of the finished cardboard product, is formed by a surface layer that must have a high degree of surface smoothness to provide good printability. Special pulps are used for manufacturing the surface layer. Short-fiber pulps result in surface layers with improved printability. The pulp intended for the printable surface layer is preferably, but not necessarily, bleached. It may consist of a mixture of short-fiber and long-fiber pulps, in which the short-fiber proportion of the pulp may constitute 50-70 percent by weight of the mass. However, the short-fiber proportion may constitute 100 percent. The layer to be printed may also be made of 100 percent bleached long-fiber pulp. Short-fiber pulp can be pulp from birch or eucalyptus, for instance, while long-fiber pulp can be pulp from pine, for instance.
[0005] A number of methods and machines for manufacturing multilayer cardboard webs are described in patent literature and the following are mentioned by way of example: EP-0 511 186, WO 92/06242, U.S. Pat. No. 4,961,824,EP-0 511 185, U.S. Pat. No. 5,074,964, EP-0 233 058 and SE-506 611.
[0006] U.S. Pat. No. 5,639,349 (corresponding to DE-4401761) describes a method for improving the quality of multilayer papers in the wet section of a paper machine by recirculating the drainage water within each forming unit. The outer layer of the paper web is made of stock of higher quality than the stock for the core. The patent specification does not mention cardboard or board and the problem associated with providing a printable surface layer on a multilayer cardboard web. Neither does the patent specification touch upon the problem relating to the press section and the web run in the same, and in particular does not address the problem of pressing of a multilayer cardboard web with a printable surface layer.
[0007] U.S. Pat. No. 4,957,778 describes a paper machine for manufacturing two-layer carbonless copy paper. The paper machine has upper and lower fourdrinier formers, the layers of which are combined by couching to form a coherent paper web, which is pressed in a press with two single-felted press nips, created by two press rolls and a counter roll shared by the same. Multilayer cardboard webs are not touched upon in this patent specification and, consequently, neither are the problems associated with pressing a multilayer cardboard web.
[0008] In practice, the predominant technique for manufacturing a multilayer cardboard web is to manufacture the surface layer with a forming unit, for instance an upper fourdrinier former, arranged relative to at least one other forming unit, for instance a lower fourdrinier former, in such a way that the surface layer is couched with a subjacent layer and the cardboard web emerges from the wet section with the surface layer facing upwards. This in turn dictates the configuration of the press section. In accordance with conventional techniques, a double-felted roll press is employed as the first press. It is also known to use a double-felted shoe press with the shoe in a top or bottom position as the first press. A first double-felted press of known kind has an upper felt acting as a pick-up felt to transfer the cardboard web to the press nip, while the lower felt is intended to carry the cardboard web subsequent to its passage through the press nip. The surface layer of the cardboard web thus comes into direct contact with the upper felt. Accordingly, to be able to satisfy the requirement of high surface smoothness of the surface layer, the structure of the web-contacting surface of the upper felt must not be too rough. If, on the other hand, the structure of the web-contacting surface of the lower felt were to be too smooth or fine to ensure the correct web run after the press nip, the lower felt will not be sufficiently open to allow permeation of water and will relatively quickly become clogged with fibers, which means that reconditioning of the lower felt cannot be accomplished with the desired result and that the service life of the lower felt becomes relatively short. In practice, the two contradictory requirements for the properties of the upper felt and the lower felt result in the requirement that the differences between their surfaces structures with respect to roughness or smoothness become relatively small and there is, therefore, a risk of the cardboard web sometimes having a tendency to accompany the upper felt after the press nip instead of the lower felt as intended, even if the lower felt has the smoother surface. To ensure the correct web run in a shoe press with the shoe in the bottom position the lower felt must be passed over the downstream edge of the shoe and the upper felt passed approximately in the direction of the so-called 0 line, but this is not an acceptable solution as the web is then subjected to detrimental shear forces during its passage over the shoe edge.
SUMMARY OF THE INVENTION
[0009] The object of the present invention is to provide an improved board machine and an improved method of manufacturing a multilayer cardboard web. The invention thus enables the manufacture of a multilayer cardboard web having a printable surface layer with a desired high degree of surface smoothness and maximum dry-solids content after the press section, while safeguarding the web run in the press section.
[0010] The board machine, in accordance with the invention, is characterized in that the first forming unit is arranged to form the printable surface layer and arranged with its extended forming wire to transfer the multilayer cardboard web to the upper press felt of the press with the printable surface layer facing downwards to contact the lower press felt in the press nip. The lower press felt has a finer web-contacting surface to exert a greater adhesion force on the multilayer cardboard web than the upper press felt, and the lower press felt at the discharge side of the nip is arranged to encompass the lower press roll by a predetermined minimum sector angle α measured from a point in the press nip intersected by the 0 line of the press, as defined herein for a roll press and a shoe press, respectively.
[0011] The method, in accordance with the invention, is characterized in that the printable surface layer is formed in the first forming unit and the extended forming wire transfers the multilayer cardboard web to the upper press felt of the press with the printable surface layer facing downwards so that it is in contact with the lower press felt in the press nip. The lower press felt exerts a greater adhesion force on the multilayer cardboard web than the upper press felt by virtue of its finer web-contacting surface, and the lower press felt is caused to encompass the lower press roll by a predetermined minimum sector angle α measured from a point in the press nip intersected by the 0 line of the press, as defined herein for a roll press and a shoe press, respectively.
BRIEF DESCRIPTION OF THE DRAWINGS
[0012] The above and other objects, features, and advantages of the invention will become more apparent from the following description of certain preferred embodiments thereof, when taken in conjunction with the accompanying drawings in which:
[0013] [0013]FIG. 1 shows schematically parts of a board machine for manufacturing a multilayer board web in accordance with a first embodiment of the invention.
[0014] [0014]FIG. 2 shows schematically parts of a board machine for manufacturing a multilayer cardboard web in accordance with a second embodiment of the invention.
[0015] [0015]FIG. 3 is a cross section along the line III-III in FIG. 1.
[0016] [0016]FIG. 4 shows schematically a part of a shoe press used in the board machines shown in FIGS. 1 and 2.
[0017] [0017]FIG. 5 shows schematically a roll press in a board machine for manufacturing a multilayer cardboard web in accordance with a third embodiment of the invention.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
[0018] The present invention now will be described more fully hereinafter with reference to the accompanying drawings, in which preferred embodiments of the invention are shown. This invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art. Like numbers refer to like elements throughout.
[0019] [0019]FIGS. 1 and 2 show schematically parts of a board machine for manufacturing a cardboard web 1 , consisting of a first layer 2 and a further layer 3 . In the embodiment shown and in accordance with the present invention, the first layer 2 forms a surface layer in the finished two-layer cardboard web, while the further layer 3 forms its core. Alternatively, a cardboard web is manufactured, consisting of said first layer and several further layers, one of which is said core.
[0020] The board machines comprise a wet section 4 , a press section 5 and a drying section 6 .
[0021] The wet section 4 comprises a first forming unit 7 for manufacturing the first layer 2 and a second forming unit 8 for manufacturing the second layer 3 .
[0022] In the embodiment shown in FIG. 1, the two forming units 7 , 8 consist of a first fourdrinier former, located upstream, and a second fourdrinier former, located downstream, while in the embodiment in accordance with FIG. 2, they consist of a first twin-wire former or gap former located upstream, and a second twin-wire former or gap former located downstream. In this context, the expressions “upstream” and “downstream” indicate the relative locations of the forming units viewed in the machine direction.
[0023] The first fourdrinier former 7 , located upstream according to FIG. 1, is extended in the machine direction and has a fourdrinier wire 9 , running in a loop around an upstream breast roll 10 , a downstream suction couch 11 , a wire turning roll 12 and a plurality of other types of guide rolls 13 , such as alignment rolls and tension rolls. The upper part 14 of the fourdrinier wire 9 , dewatering the stock and forming the layer and web, between the breast roll 10 and the suction couch 11 is plane and horizontal. The first fourdrinier former 7 , located upstream, further comprises a headbox 15 , arranged close to the breast roll 10 to emit ajet of stock onto the upper part 14 of the fourdrinier wire 9 , and dewatering members 16 for dewatering the stock to form the first layer 2 .
[0024] The second fourdrinier former 8 , located downstream according to FIG. 1, has a fourdrinier wire 17 , running in a loop around a breast roll 18 , an upper guide roll 19 and two lower guide rolls 20 , which lower guide rolls are arranged in close proximity to the upper part 14 of the fourdrinier wire 9 of the first fourdrinier former 7 for couching the formed second layer with the formed first layer. The second fourdrinier former 8 comprises a headbox 21 , arranged close to the breast roll 18 to emit a jet of stock onto the upper, plane part 22 of the fourdrinier wire 17 , and dewatering members 23 for dewatering the stock to form the second layer.
[0025] The first twin wire former, located upstream according to FIG. 2, has first and second forming wires 25 , 26 , which run together in a forming zone. The first forming wire 25 runs in an upper loop around a plurality of guide rolls 27 . The second forming wire 26 runs in a lower loop around an upstream forming roll 28 and a downstream suction couch 29 , a wire turning roll 30 and a plurality of other guide rolls 31 , comprising alignment rolls and tension rolls. The lower forming wire 26 is extended up to the press section so that the suction couch 29 is located downstream of the second twin wire former 8 . In the loop of the first forming wire 25 , dewatering means 32 are arranged within said forming zone. A headbox 33 is arranged to emit a jet of stock into a gap defined by the forming roll 28 and a guide roll 27 located adjacently to the same in the upper wire loop 25 .
[0026] The second twin wire former 8 , located downstream according to FIG. 2, has first and second forming wires 34 , 35 , which run together in a forming zone. The first forming wire 34 runs in a loop around a plurality of guide rolls 36 and has a lower, linear part 37 , passing along the lower forming wire 26 of the first twin wire former 7 to create a couching zone. The second forming wire 35 runs in a loop around a forming roll 38 and, two guide rolls 39 . In the loop of the first forming wire 34 , dewatering means 40 are arranged within said forming zone. A headbox 41 is arranged to emit a jet of stock into a gap defined by the forming roll 38 and a guide roll 36 located adjacently to the same in the first wire loop 34 .
[0027] The first forming unit 7 , located upstream, is arranged to create a surface layer 2 suitable for printing in the finished cardboard web, while the second forming unit 8 , located downstream, is arranged to create a core 3 , which encounters the surface layer so that the two layers are couched together with each other to a coherent two-layer cardboard web, see FIG. 3, which leaves the forming wire 9 , 26 of the first forming unit 7 with the surface layer facing downwards.
[0028] The press section 5 in the board machines shown in FIGS. 1 and 2 comprises a first double-felted press 45 and a second double-felted press 46 , which presses 45 , 46 are arranged directly one after the other. The first press 45 comprises an upper press element 47 and a lower press element 48 , which press elements create a press nip with each other. The first press 45 further comprises an upper press felt 49 , which runs in a loop around a plurality of guide rolls 50 , comprising a pick-up suction roll 51 for transferring the multilayer cardboard web 1 to the upper press felt 49 , and a lower press felt 52 , which runs in a loop around a plurality of guide rolls 53 , and which together run through the press nip with the web 1 enclosed therebetween in a sandwich construction. The second press 46 comprises an upper press element 54 and a lower press element 55 , which press elements create a press nip with each other. The second press 46 further comprises an upper press felt 56 , which runs in a loop around a plurality of guide rolls 57 , comprising a pick-up suction roll 58 for transferring the multilayer cardboard web 1 to the upper press felt 56 , and a lower press felt 59 , which runs in a loop around a plurality of guide rolls 60 , and which together run through the press nip with the web 1 enclosed therebetween in a sandwich construction.
[0029] The lower press felt 52 , 59 of each press 45 , 46 has a finer surface structure than the upper press felt 49 , 56 with the purpose of ensuring that the web 1 adheres to the lower press felt 52 , 59 and not to the upper press felt 49 , 56 after the press nip. This difference in surface structure or adhesive capability is a first parameter to assist in safeguarding the correct web run.
[0030] The lower press element 48 , 55 in each press is a press roll, around which the lower press felt 52 , 59 runs in contact with the envelope surface of the press roll after the press nip by a pre-determined minimum sector angle α measured from a certain point in the press, depending on which type of press is used, as explained below. The web has a tendency to accompany the one of the two press felts that has the greater part in contact with the press roll after the press nip. This circumstance is a second parameter to assist in safeguarding the correct web run. At least the first parameter, and preferably both the first and second parameters, are utilized in the press, while the printable surface layer 2 simultaneously faces downwards. This enables an increased difference between the degrees of surface smoothness of the lower and upper felts. At the same time, the lower press felt is caused to maintain contact with the lower press roll downstream of the nip for a predetermined sector angle. Thus, the proper web run is facilitated.
[0031] The press sections 5 shown in FIGS. 1 and 2 are alike and their presses consist of a first shoe press 45 with a press shoe 63 and a subsequent, second shoe press 46 with a press shoe 64 . Each shoe press 45 has a shoe roll 47 , 54 in the upper position and a counter roll 48 , 55 in the lower position. Each counter roll 48 , 55 can have a blind-drilled, grooved or smooth envelope surface. Each shoe roll or one of the shoe rolls has an envelope surface 65 , see FIG. 4, in the shape of a press belt that is smooth, blind-drilled or grooved. From the point of view of operability, a blind-drilled or grooved press belt 65 is preferable, as this provides a large open volume behind the upper press felt 49 , 56 so that the cardboard web acquires a high dry-solids content while the upper press felt simultaneously remains open towards the open surface behind the upper press felt to enable ventilation of the same. Such high dry-solids content is further improved by employing a blind-drilled or grooved counter roll, thus providing a large open volume behind the lower press felt 52 , 59 . In especially difficult operating conditions, such as high web speed and low surface weight, a counter roll with a smooth envelope surface is used because the large open volume is not required, as smaller quantities of water (low surface weight) need to be removed and an extra great vacuum pulse is created in the lower press felt, which results in the “attraction” of the web to the lower felt being increased still further. Placing the shoe rolls in a top position creates enhanced possibilities for guiding the cardboard web to the lower press felt by arranging the lower felt to encompass the counter roll to a greater extent.
[0032] The lower press felt 52 is arranged to encompass the counter roll 48 with a pre-determined minimum sector angle α of 10° measured from a point (denoted a 0 point herein) on the periphery of the shoe 63 at which the concave curvature of the shoe transitions into a convex curvature, the tangent of this point being denoted the 0 line 61 of the shoe. The part of the upper press felt 49 surrounding the counter roll 48 is adjustable within a range from +5° to −5° measured as an angle β between the upper press felt 49 and the 0 line 61 , positive angle values being located below and negative angle values above this 0 line 61 .
[0033] Alternatively, the first press 45 can consist of a roll press as shown in FIG. 5. The second press 46 in such a press section can be a similar roll press or a shoe press as described above. The upper and lower press rolls 47 , 48 of the roll press can have smooth, blind-drilled or grooved envelope surfaces. The lower press felt 52 , see FIG. 5, is arranged to encompass the lower press roll 48 by a pre-determined minimum sector angle α of 10° measured from a 0 point on the periphery of the lower press roll 48 that is tangent to the periphery of the upper press roll. Stated differently, the 0 point is located on the periphery of the lower press roll 48 at a point intersected by a straight line connecting the centers of the press rolls 48 , 47 . The tangent to this 0 point is perpendicular to the straight line intersecting the centers of the press rolls, which tangent is denoted as the 0 line 62 of the roll press. The sector angle α is normally in the range 10°-25° for a roll press. The part of the upper press felt 49 surrounding the lower press roll 48 is adjustable within a range from +10° to −5° measured as an angle between the upper press felt 49 and the 0 line 62 , positive angle values being located below and negative angle values above this 0 line 62 .
[0034] Many modifications and other embodiments of the invention will come to mind to one skilled in the art to which this invention pertains having the benefit of the teachings presented in the foregoing descriptions and the associated drawings. Therefore, it is to be understood that the invention is not to be limited to the specific embodiments disclosed and that modifications and other embodiments are intended to be included within the scope of the appended claims. Although specific terms are employed herein, they are used in a generic and descriptive sense only and not for purposes of limitation. | A board machine and method for making a multilayer cardboard web, in which a first layer of the web having a printable surface is formed in a first forming unit and carried on an extended forming wire thereof through a couching unit where the first layer is couched with one or more additional layers, the multilayer web then being carried on the extended wire to a pick-up point. An upper press felt of a double-felted press picks up the web at the pick-up point such that the printable surface faces downward and contacts the lower press felt through the nip of the press. The lower felt is smoother than the upper felt, and the lower felt contacts the lower press roll for a minimum sector angle beyond an exit of the nip to ensure that the web follows the lower felt. | 3 |
[0001] This Application claims the benefit of U.S. Provisional Application Ser. No. 60/466,292 filed Apr. 29, 2003.
FIELD OF THE INVENTION
[0002] This invention relates generally to light reflective and locational pavement markers for use in identifying the lines or boundaries of roadway surfaces. More specifically, the invention relates to an improved version of a highway lane delineator in the form of a flexible raised pavement marker that is made entirely from plastic and rubber. It also relates specifically to a flexible reflective pavement marker that is both easy to recycle and much less damaging to plow implements.
BACKGROUND OF THE INVENTION
[0003] Current pavement markers are comprised of a steel frame having two parallel side rails designed to protect a reflector that is situated between the two side rails. These current pavement markers have several drawbacks. First, the steel side rails are designed to deflect the force of a plow blade, thus protecting the reflector. This constant striking and bouncing, however, causes undesirable and potentially costly wear and tear to the plow mechanism and to the plowing vehicle. It is also distracting to the plow operator who must endure the effect over many miles of interstate highway plowing. Secondly, current road repair and replacement techniques frequently involve grinding up large sections of roadway. The current steel markers need to be removed by hand before road resurfacing equipment can grind down the existing road surface. This process is often difficult and time-consuming due to the fact that the pavement markers are frequently bonded using high-strength epoxies. Additionally, steel is expensive to fabricate in comparison to injection molding, and expensive to ship in relation to the lightweight materials employed in the present invention. Lastly, steel reflectors can be dangerous missiles if inadvertently dislodged for any reason.
[0004] In the experience of this inventor, there is an established and convenient way in which the markers are currently mounted. In general, standard size diamond cutting blades are used to cut two parallel side grooves in the pavement. A center groove is then cut between the side grooves. The device of the present invention is designed to use the same mounting hole as is currently used for steel markers, as this is an established and efficient way of mounting them, particularly in reinforced concrete interstate highways.
[0005] The pavement marker of the present invention provides for a one-way reflector design, which is used for the majority of interstate markers. The marker uses the same size reflector that is mounted in the same relationship to the road surface as are steel markers. This insures the same reflectivity as is currently produced by steel markers, with the same reflector cleaning effect of tire action. Also, the low weight of plastic which is used to produce the marker of the present invention makes the unit safer if inadvertently dislodged and less expensive to ship. When grinding road surfaces, the pavement marker of the present invention can simply be ground up with the rest of the road surface without removing the unit from the roadway. It also may be possible to use reground tires for at least a portion of the rubber component of the marker of the present invention, thus helping to recycle this material.
[0006] In the marker of the present invention, an articulating plastic-rubber assembly is attached to a retro-reflector, which enables the reflector to move slightly downwardly and out of the way of snowplow blades. The device is intended as an alternative to steel raised pavement markers and has numerous advantages. The two main benefits of the marker of this invention are the elimination of the bouncing of the plow blade and the low cost of manufacture associated with injection molding. The foregoing and other features and advantages of the device of the present invention will be apparent from the detailed description that follows.
BRIEF DESCRIPTION OF THE DRAWINGS
[0007] [0007]FIG. 1 is a top, right side and rear perspective view of a pavement marker constructed in accordance with the present invention.
[0008] [0008]FIG. 2 is a top, right side and rear perspective view of the marker shown in FIG. 1 as it would appear installed in the installation grooves cut into a road surface.
[0009] [0009]FIG. 3A is a top plan view of the right leg assembly of the marker.
[0010] [0010]FIG. 3B is a right side elevational view the right leg assembly of the marker.
[0011] [0011]FIG. 3C is a rear elevational and cross-sectional view of the right leg assembly of the marker taken along line A-A of FIG. 3B.
[0012] [0012]FIG. 3D is an enlarged detail view of the view shown in FIG. 3C.
[0013] [0013]FIG. 4A is a top, left side and front perspective view of the right leg assembly of the marker shown in FIG. 3B.
[0014] [0014]FIG. 4B is a top, right side and rear perspective view of the right leg assembly of the marker shown in FIG. 3B.
[0015] [0015]FIG. 4C is an enlarged detail view of the front end of the right leg assembly illustrating the inside of the circular joint and showing the notch between the upper and lower leg.
[0016] [0016]FIG. 4D is another enlarged view of the front end of the right leg assembly illustrating the outside of the circular joint and showing the notch between the upper and lower leg.
[0017] [0017]FIG. 4E is an enlarged partial right elevational view of the front end of the right side leg assembly of the marker and showing the detail of the circular joint.
[0018] [0018]FIG. 4F is a rear elevational and cross sectional view of the circular joint taken along line B-B of FIG. 4E.
[0019] [0019]FIG. 4G is a front elevational and cross sectional view of the circular joint taken along line C-C of FIG. 4E.
[0020] [0020]FIG. 5A is a top plan view of the pavement marker shown installed in a road.
[0021] [0021]FIG. 5B is a right side elevational and cross sectional view of the pavement marker as installed in a road taken along line D-D of FIG. 5A.
[0022] [0022]FIG. 6A is a top plan view of the pavement marker shown installed in a road.
[0023] [0023]FIG. 6B is a right side elevational and cross sectional view of the pavement marker as installed in a road taken along line E-E of FIG. 6A.
[0024] [0024]FIG. 7A is a top plan view of the pavement marker as installed in a road and showing a portion of a snowplow blade passing over the right leg assembly of the marker.
[0025] [0025]FIG. 7B is a right side elevational and cross sectional view of the pavement marker and snowplow blade taken along line F-F of FIG. 7A.
[0026] [0026]FIG. 8A is a top plan view of the pavement marker as installed in a road and showing a portion of a snowplow blade passing over the right leg assembly of the marker.
[0027] [0027]FIG. 8B is a right side elevational and cross sectional view of the pavement marker and snowplow blade taken along line G-G of FIG. 8A.
[0028] [0028]FIG. 9 is a top, front and right side perspective view of one embodiment of the pavement marker and showing a removable reflector.
DETAILED DESCRIPTION OF THE INVENTION
[0029] Referring now to the drawings in detail, wherein like numbers refer to like numbered elements throughout, FIG. 1 illustrates a pavement surface marker, generally identified 2 , constructed in accordance with the present invention. In the preferred embodiment, the marker 2 is constructed primarily of a lightweight plastic material. As shown, a plastic reflector 1 , is attached to and suspended between two mirror-imaged upper leg components 3 of the marker 2 . Each of the upper leg components 3 is pivotally attached to a lower leg component 5 . On each side of the marker 2 , a rubber flange 7 which is part of the natural rubber component, is interposed between the upper leg component 3 and the lower leg component 5 . The flanges 7 prevent the attaching material, an epoxy adhesive, from oozing onto the upper leg components 3 . The flanges 7 serve an additional purpose, which is to hold the marker 2 in place during installation, thereby resisting the tendency of the lightweight plastic device to float out of the groove 11 in which the lower leg components 5 are placed on top of the liquid epoxy. A separate rubber bladder 9 is bonded to the bottom of the reflector 1 with adhesive which prevents the formation of ice under the reflector 1 . The bladder 9 also works to keep dirt and other road debris from getting under the reflector 1 and preventing it from flexing below ground level.
[0030] [0030]FIG. 2 shows the marker 2 as it would appear installed in a road surface 10 . Existing diamond saw machines with ‘standard’ 18 and 20-inch diameter blades are used to produce two parallel and longitudinally extending side grooves 11 and a shallower center groove 13 that extends between the side grooves 11 . Four leveling tabs, one on each of the lower legs 25 and one on each of the upper legs 27 , are used to visually insure that the marker 2 is set at the correct depth during installation.
[0031] [0031]FIGS. 3A and 3B show in greater detail the right leg assembly 3 , 5 , which is an exact mirror image of the opposite left leg assembly. FIGS. 3C and 3D show the rubber component 14 , which provides the flanges, 7 and which is molded into the two plastic lower leg components 5 and held in place by thermal bonding and grooves 15 which run the length of the plastic lower leg components 5 . The rubber component 14 forms a protective void, keeping water and debris from entering into the area that the upper legs 3 flex into. In the preferred embodiment, ribbing spaces 17 are formed in the lower legs 5 and serve to provide compressive strength and also a large undercut volume for the epoxy to flow into. This strong mechanical bond is a substantial improvement in retention safety versus the purely chemical bond on common steel markers.
[0032] [0032]FIGS. 4F and 4G illustrate the novel way that the upper legs 3 are joined with the lower legs 5 . Equal-sized notches 19 are molded into each of connections between an upper leg 3 and a lower leg 5 which surrounds a centralized, circular, common section 21 . During manufacture, this entire area, including the circular common section 21 becomes filled with rubber and, in effect, forms a torsion spring, holding the reflector 1 in its normal position. When depressed by a tire or snowplow blade 47 , the natural position of the rubber forces the two leg components 3 back to the normal position. This occurs due to the rubber filling the notches 19 and the circular common section 21 . When the pavement marker 2 is depressed, the rubber cores 23 act as a resilient torsional spring, applying pressure via the notches 19 to return the marker 2 to its raised position. There are positive mechanical stops in both positions resulting from the molded geometry of the plastic parts.
[0033] The perspective views of FIGS. 4A and 4B show grooves 29 that are molded into both plastic parts 5 for improving the bond between the rubber and the two plastic parts 5 in each leg assembly. The post 31 also serves a dual purpose as a stress reliever for the reflector 1 , resisting unequal forces between the two upper leg components 3 . This could occur, for example, when one upper leg component 3 is depressed by a tire or plow blade 47 and the other upper leg component 3 is not. The post 31 is also used as a fill point for the injection of the special plastic material needed to resist the severe impact of plow blades. A pair of top tabs 33 together with a bottom tab 35 , act in conjunction with the post 31 to hold the reflector 1 in place.
[0034] [0034]FIGS. 5A through 8B show the normal configuration of the marker 2 compared to its position when struck by a plow blade. For example, FIG. 5B shows the marker 2 in its normal position and also shows the road 10 and the epoxy adhesive 37 , which has flowed between the ribs 17 in the lower leg components 5 . The protected void 41 is evident as is the mechanically reinforced rubber bond 43 across the top of the void. FIG. 6B shows the marker 2 in its normal position and shows the rubber bladder 9 and its associated void 45 which serve to prevent ice and debris from collecting under the reflector 1 . FIGS. 7A and 7B show a snowplow blade 47 striking and depressing the upper leg components 3 . This movement pivots on the center of the radius 49 thereby causing the two plastic parts 3 , 5 to meet along a shared radius 51 . The rubber segment 43 between the upper legs 3 and the lower legs 5 stretches to keep the seal intact. The air inside the void 41 becomes pressurized momentarily. In the case of stopped traffic, where the marker 2 may become depressed for many minutes, there is enough of a gap between the normal position of the marker 2 and the sidewalls of the cut 11 , 13 in the road 10 to allow the rubber to controllably expand without compromising the seal. FIGS. 8A and 8B show the position of the reflector 1 and air bladder 9 when a plow blade 47 strikes the marker 40 . The normal position of the upper leg components 3 and reflector 1 are show as dotted lines. The pivot point is shown at the center of the dotted circle 53 .
[0035] The present invention, in one embodiment, provides for an easily removable and replaceable reflector 1 . See FIG. 9. The removable reflector is mounted in bracket 55 , bracket 57 and is reinforced by a reinforcing bar 59 . Therefore, in areas of high roadway use where the potential for damaging reflectors exists, the reflector 1 can be replaced without replacing the entire unit. Additionally, areas in which it snows frequently use salt and other corrosives, which may damage the reflective surface, also show a need for a removable and replaceable reflector 1 .
[0036] One possible manner of constructing the marker 2 of the present invention is to use an impact resistant plastic material to injection mold the upper leg components 3 . This material has a substantial long glass fiber content yet can replicate fine detail. When the material has cooled sufficiently, a coating of carbon-filled natural rubber is molded onto it, thereby creating half of the rubber seal between the two plastic parts 3 , 5 . The bottom leg components 5 are molded separately of a less impact resistant plastic than the upper leg components 3 , 4 and can be added to the mold containing the upper leg component 3 in a two shot molding process. The remainder of the rubber is molded to the assembly, creating the elastic pivot 21 and the side flanges 7 as well as sealing the leg assembly. The center air bladder 9 is produced from two molded halves that have mating features that facilitate the adhesive or thermal bonding of the two halves. | A reflective surface marker comprising a pair of generally parallel lower legs, each leg having a first end; a pair of generally parallel upper legs, each leg having a first end; a flexible hinge resiliently connecting the first end of said lower leg to the first end of said upper leg; a reflective material connecting said upper legs; and a bladder for resiliently supporting the reflective material. | 4 |
This application is a continuation of application Ser. No. 08/341,076, filed Nov. 17, 1994, now abandoned.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates generally to integrated circuits, and more specifically to a test mode power circuit for the integrated circuits.
2. Description of the Related Art
In a conventional test mode power circuit of an integrated-circuits chip, an internal voltage is generated as a power supply for the internal circuitry of the chip due to difficulty of laying power lines from an external voltage supply to the interior of the chip. This internal voltage is adjusted during a fabrication process by the use of variable resistors and compared by a comparator to a test voltage supplied from an external test circuit, producing an output indicating whether the internal voltage is higher or lower than the test voltage. Because of the limitations imposed by the layout of the chip, the comparator output signal must propagate through a long path to the test circuit. First and second buffer amplifiers are used in the propagation path. Since the first buffer amplifier is located inside of the chip, the power supply of this amplifier is taken from the internal voltage source, while the power supply of the second is taken from the external sources However, since the internal voltage is used both for comparison to the test voltage and for powering the first buffer amplifier, the latter will not operate during the time prior to the adjustment of the variable resistors if the internal voltage is lower than the threshold voltage of the first buffer amplifier, thus narrowing the test range of the power supply circuit.
SUMMARY OF THE INVENTION
It is therefore an object of the present invention to provide a test mode power supply circuit for an integrated-circuit chip having a greater test range for internal power supply voltage.
According to a first aspect of the present invention, there is provided a power supply circuit for an integrated-circuit chip having a test circuit. The power supply circuit includes a variable resistor setting means for establishing an internal voltage for the integrated-circuit chip, the internal voltage being variable by adjustment of the variable resistor setting means, and a comparator for comparing the internal voltage to a test voltage supplied from the test circuit to produce an output voltage indicating whether the internal voltage is higher or smaller than the test voltage. A first buffer amplifier, powered by an externally supplied voltage, amplifies the output voltage of the comparator to produce at least one output voltage. A second buffer amplifier, powered by the externally supplied voltage, amplifies the output voltage of the first buffer amplifier to supply an output voltage to the test circuit.
According to a second aspect, the present invention provides a power supply circuit for an integrated-circuit chip having a test circuit, comprising a first voltage source including variable resistor setting means for establishing a first internal voltage for the integrated-circuit chip, the first internal voltage being variable by adjustment of the variable resistor setting means. A second voltage source establishes a second internal voltage higher than the first internal voltage. A comparator compares the first internal voltage to a test voltage supplied from the test circuit to produce an output voltage indicating whether the first internal voltage is higher or smaller than the test voltage. A first buffer amplifier, powered by the second internal voltage, amplifies the output voltage of the comparator and produces at least one output voltage, and a second buffer amplifier, powered by an externally supplied voltage, amplifies the output voltage of the first buffer amplifier and supplies an output voltage to the test circuit.
BRIEF DESCRIPTION OF THE DRAWINGS
The present invention will be described in further detail with reference to the accompanying drawings, in which:
FIG. 1 is a block diagram of a prior art power supply circuit of an integrated-circuit chip;
Fig. 2 is a Shmoo plot of the prior art power circuit;
FIG. 3 is a block diagram of a power supply circuit according to a first embodiment of the present invention;
FIG. 4 is a Shmoo plot of the power supply circuit of the present invention; and
FIG. 5 is a block diagram of a power supply circuit according to a second embodiment of the present invention.
DETAILED DESCRIPTION
Before proceeding with the detailed description of the present invention, it may prove helpful to provide an explanation of a prior art LSI power supply circuit with reference to the block diagram of FIG. 1. The prior art LSI power supply circuit generally comprises first and second reference voltage generators 1 and 2, an internal voltage generator 3 for generating a voltage V int for use within the LSI chip, a comparator 4 for making a comparison between the voltage V int and a test voltage supplied from an external test circuit 5, and a series connection of first and second buffer amplifiers 6, 7 connected to the output of comparator 4 to produce an output signal for coupling to the test circuit 5 as a result of the comparison.
Specifically, the first reference voltage source 1 includes a pair of PMOS transistors 8, 9 of identical gain with their sources connected together in a current mirror configuration to the external voltage supply V cc via current source 10, with the drain and gate of transistor 8 connected together to ground and the drain and gate of transistor 9 being connected together to ground via a constant current source 11. The transistors 8 and 9 are operated in their saturation region to develop a reference voltage V m across the constant current source 11. Since the gate of transistor 8 is grounded, the reference voltage V m is equal to the difference in absolute value between the threshold voltages of transistors 8 and 9. To develop a sufficient voltage V m the threshold voltage of transistor 8 is set at a value higher than that of transistor 9. The voltage V m is supplied to the second reference voltage source 2 as a reference voltage.
The second reference voltage source 2 is a current mirror, high open-loop gain differential amplifier formed with a pair of PMOS transistors 14, 15 with their sources connected together to the external voltage supply V cc to form a high open-loop gain current mirror, and a pair of NMOS transistors 16, 17 which form a differential amplifier. The drain of NMOS transistor 16 is connected to the input of the current mirror and the drain of NMOS transistor 17 is connected to the output of the current mirror to which the gate of a PMOS transistor 13 is also connected. The sources of NMOS transistors 16, 17 are connected together to a constant current source 18 which is grounded. Variable resistors 19 and 20 are connected in series between ground and the source-drain path of PMOS transistor 13 to the voltage supply V cc . The reference voltage V m from the first reference voltage source is applied to the gate of NMOS transistor 17 and a voltage developed at the junction between variable resistors 19 and 20 is applied to the gate of NMOS transistor 16.
By virtue of the differential operation of the transistors 16, 17, the voltage at the junction between resistors 19, 20 is made equal to the input reference voltage V m , and a voltage V ref develops at the junction between the drain of transistor 13 and resistor 19 as an output of the second reference voltage source 2. Therefore, voltage V ref is equal to {1+(R1/R2)}V m , where R1 and R2 are the resistances of variable resistors 19 and 20. If there is a decrease (or increase) in voltage V ref from the normal level, there is a corresponding voltage drop (or rise) at the junction between resistors 19 and 20, which is fed back to the current mirror to produce a voltage drop (or rise) at the gate of PMOS transistor 21, As a result, there is an increase (or decrease) in current supplied from the external voltage supply V cc to the PMOS transistor 21 to (or decrease) voltage V.sub. ref. The feedback operation continues until voltage V ref returns to the normal level. The voltage V ref is supplied to the internal voltage generator 3.
The internal voltage generator 3 includes a pair of PMOS transistors 22, 23 with their sources connected together to the external voltage supply V cc to form a current mirror. Differential amplifier NMOS transistors 24, 25 are connected between the current mirror transistors 22, 23 and a constant current source 26 which is grounded. The internal voltage V int is established at the junction between the gate of NMOS transistor 24 and the drain of a PMOS transistor 21 whose gate and source are connected to the drain of transistor 23 and the voltage supply V cc , respectively, to form a feedback circuit to keep the voltage V int at a constant level in the same manner as the second reference voltage source 2. The internal voltage V int is supplied the comparator 4 as well as to the load circuit of the LSI power circuit.
The comparator 4 is comprised by current mirror PMOS transistors 27, 28 connected to the voltage supply V cc and differential amplifier NMOS transistors 29, 30 connected between the current mirror transistors and an NMOS switching transistor 31 which is grounded. The test voltage from the test circuit 5 is coupled to the gate of transistor 29 and the internal voltage V int is coupled to the gate of transistor 30. Switching transistor 31 is turned on in response to an enable pulse which is supplied from the test circuit during a test mode. The enable pulse is also supplied to the gate of a PMOS switching transistor 32 whose source-drain path is connected in parallel with the source-drain path of transistor 28. A pair of a PMOS transistor 33 and an NMOS transistor 34 is provided having their gates connected together and their source-drain paths connected in series between the voltage supply V cc and ground to form a first CMOS inverter, with the junction at their gates serving the input of the first CMOS inverter and coupled to the drain of transistor 32 and the junction at their source-drain paths being the output of the first CMOS inverter. A second CMOS inverter is likewise formed by a pair of PMOS transistor 35 and an NMOS transistor 36, the input of the second CMOS inverter being connected to the output of the first CMOS inverter.
The NMOS switching transistor 31 is normally in the OFF state to disable the current mirror differential amplifier, while the PMOS switching transistor 32 is normally in the ON state and therefore the output of the second CMOS inverter is normally at zero voltage level. In response to an enable pulse from the test circuit, the NMOS switching transistor 31 is turned on to allow the current mirror differential amplifier to develop a difference voltage between the test voltage and the internal voltage V int at the junction between transistors 28 and 30, while the PMOS transistor 32 is turned off to allow the inverter transistors 33 to 36 to respond to the difference voltage to produce a clearly defined voltage VD 1 at the output of the comparator 4 during the test mode. As will be described, to measure the voltage V int the output voltage of the second buffer amplifier 7 is checked to see if it is 1 or 0 while varying the test voltage in a specified range.
The voltage VD 1 from comparator 4 is supplied to the first buffer amplifier 6 which is also enabled during the test mode, and the output of the first buffer amplifier 6 is connected to the input of the second buffer amplifier 7. The purpose of the first and second buffer amplifiers is to offset the attenuation of the output signal of the comparator as it propagates through the LSI chip to the test circuit S. The first buffer amplifier 6 is fabricated in an inner location of the LSI chip that is far removed from the external access points of the voltage supply V cc . Because of the difficulty to form power lines as well as ground lines from the external access points to the inner location of the chip, the first buffer amplifier 6 uses the internal voltage V int as a power voltage.
The first buffer amplifier 6 includes a first CMOS inverter formed by a pair of a PMOS transistor 37 and an NMOS transistor 38 and a second CMOS inverter formed with a pair of a PMOS transistor 39 and an NMOS transistor 40, with the sources of the transistors 37 and 39 being connected to the output-of internal voltage generator 3. The output of the comparator 4-is applied to the input of the first CMOS inverter transistors 37, 38 and the output of the first CMOS inverter is applied to the input of a the second CMOS inverter transistors 39, 40 and to a first input of a second NAND gate formed with PMOS transistors 45, 48 and NMOS transistors 46, 47. The output of the second CMOS inverter is connected to a first input of a first NAND gate formed with PMOS transistors 41, 44 and NMOS transistors 42, 43. The sources of the PMOS transistors 41, 44, 45 and 48 are connected to the internal voltage supply V int . The enable pulse from the test circuit 5 is applied to the second inputs of the first and second NAND gates, i.e., the gates of NIMOS transistors 43, 47 and the gates of PMOS transistors 44, 48. With this arrangement, the output voltage of the comparator 4 is amplified by the first and second CMOS inverter transistors 37-40 and the application of an enable pulse to the first buffe amplifier 6 causes a voltage VD 2 (which is inverse to VD 1 ) to appear at the drain of PMOS transistor 44 whose source-drain path is in shunt with that of PMOS transistor 41 and causes a voltage VD 3 (which is inverse to VD 2 ) to appear at the drain of PMOS transistor 48 whose source-drain path is in shunt with that of transistor 45. Therefore, the output voltages VD 2 and VD 3 can vary in the range between the ground potential and the internal voltage V int .
The second buffer amplifier 7 is fabricated in a location close to the external access points of the voltage supply V cc and includes an NMOS transfer gate transistor 49 having its gate connected to the internal voltage supply V int and its source-drain path connected to the drain of transistor 44 for coupling the voltage VD 2 to the drain of a PMOS feedback transistor 50 whose source is connected to the external voltage supply V cc . A first CMOS inverter is formed with a PMOS transistor 51 and an NMOS transistor 52, with their source-drain paths being connected between the voltage supply V.sub. cc and ground. The gate of transistor 51 is connected to receive the voltage VD 2 from the transmission gate transistor 49, the gate of transistor 52 being connected to receive the voltage VD 2 direct from the drain of transistor 44. The junction between the first CMOS transistors 51 and 52 is connected to the gate of transistor 50 to form a feedback path and further connected to the gate of an NMOS transistor 55. On the other hand, the output voltage VD 3 is connected to the input of a second CMOS inverter formed with a PMOS transistor 53 and an NMOS transistor 54, with their source-drain paths being connected between the voltage supply V cc and ground. The junction between the second CMOS transistors 53, 54 is connected to the gate of an NMOS transistor 56 whose source-drain path is connected in series with the source-drain path of transistor 55 between the voltage supply V cc and ground.
In order to compensate for the difference in power supply voltage between the first and second buffer amplifiers 6 and 7, it is necessary to ensure that when there is a change in voltage VD 2 from low to high level, the gate of transistor 55 is driven sufficiently to low level. This is done by the feedback transistor 50 which feeds the gate voltage of NMOS transistor 55 back to the gate of transistor 51 so that the latter is driven to the level of voltage supply V cc from the level of the voltage V int .
When the test voltage is lower than the internal voltage V int , voltage VD 1 is low and voltages VD 2 and VD 3 are high and low, respectively, and transistors 55 and 56 are turned off and on, respectively, to produce a low level output. If the test voltage is higher than the internal voltage, transistors 55 and 56 are turned on and off, respectively, to produce a high level output.
During non-test modes, both of the voltages VD 2 and VD 3 are high and both of the transistors 55 and 56 are turned off, so that the output terminal V 0 of the second buffer amplifier 7 is maintained at a high impedance state.
Variable resistors 19 and 20 are trimmed to adjust the reference voltage V ref to a specified value. However, since the internal voltage is used for powering the first buffer amplifier 6 as well as for comparison with the test voltage, the threshold voltages of all transistors of the first buffer A amplifier are higher than those of the second buffer amplifier. As a result, during a fabrication process prior to the adjustment of variable resistors 19 and 20, the V int -driven first buffer amplifier 6 does not operate as desired, and no valid output is produced by the second buffer amplifier 7 if the internal voltage V int is lower than 2.3 volts, as illustrated in the Shmoo plot of FIG. 2.
Referring now to FIG. 3, there is shown an LSI power circuit according to a first embodiment of the present Invention. In FIG. 3, parts corresponding to those in FIG. 1 are marked with the same numerals as those used in FIG. 1 and their details are not shown for simplicity. According to the first embodiment, the first buffer amplifier 6 is fabricated in a location of the LSI chip close to the external access points of the voltage supply V cc and power lines are laid out from the external access points to the amplifier 6, instead of from the internal voltage generator 3, to reduce the threshold variability of the transistors of amplifier 6. The first buffer amplifier 6 thus operates in the range between the external voltage V cc and ground potential and produces output voltages VD' 2 and VD' 3 which are higher than the voltages VD 2 and VD 3 .
Since the first buffer amplifier 6 operates with V cc , it is not necessary to provide V int -V cc conversion. Thus, the transistors 49 and 50 of FIG. 1 are not employed and the voltage output VD' 1 from the V cc -driven buffer amplifier 6 is directly applied to the gates of transistors 51 and 52 of the second buffer amplifier 7'.
Due to the use of a V cc -driven buffer amplifier 6, the threshold voltages of its transistors are lowered to approximately 1.2 volts as illustrated in FIG. 4, increasing the range of voltages that can be measured.
FIG. 5 shows the power circuit according to a second embodiment of this invention. According to this embodiment, a third reference voltage source 60 and a second internal voltage generator 61 are provided in addition to the first and second reference voltage sources 1, 2 and the first internal voltage generator 3. The third reference voltage source 60 is of generally similar configuration to the first reference voltage source, but it generates a reference voltage V' ref which is higher than the reference voltage V ref produced by the second reference voltage source 2. The second internal voltage generator 61 uses the reference voltage V' ref to generate a second internal voltage V' int which is higher than V int . The first buffer amplifier 6 utilizes this second internal voltage V' int to activate its transistors to generate the pair of voltages VD 2 and VD 3 for the second buffer amplifier 7 identical to that of the first embodiment. The first internal voltage V int is applied to the comparator 4 as well as to the load circuit.
Specifically, the third reference voltage source 60 includes current mirror PMOS transistors 62, 63 and differential amplifier NMOS transistors 64, 65 and an AMOS transfer-gate transistor 66 which conducts in response to the enable pulse from the test circuit 5 for coupling the transistors 64, 65 to ground. The drains of NMOS transistors 64 and 65 are connected to the input and output of the current mirror, respectively. To the output of the current mirror is connected the gate of a PMOS transistor 67. Variable resistors 68 and 69 are connected in series between ground and the voltage supply V cc , via the source-drain path of PMOS transistor 67. The reference voltage V m from the First reference voltage source 1 is applied to the gate of NMOS transistor 65 as well as to the second reference voltage source 2 and a voltage developed at the junction between variable resistors 68 and 69 is applied to the gate of NMOS transistor 64. Variable resistor 68 has a higher resistance value than that of resistor 19 of the second reference voltage source 2. The reference voltage V' ref is established by the third reference voltage source 60 and supplied to the second internal voltage generator 61.
The second internal voltage generator 61 includes a pair of PMOS 7 transistors 70, 71 with their sources connected together to the external voltage supply V cc to form a current mirror Differential amplifier transistors 72, 73 are connected between the current mirror transistors 70, 71 and a transfer-gate transistor 74 which conducts in response to the enable pulse for coupling the transistors 72, 73 to ground. The internal voltage V' int is established at the junction between the gate of NMOS transistor 72 and the drain of a PMOS transistor 75 whose gate and source are connected to the drain of transistor 71 and the voltage supply V cc , respectively, to form a feedback circuit to keep the voltage V' int at a constant level in the same manner as the second internal voltage generator 3. The internal voltage V' int is the power supply voltage of the first buffer amplifier 6. Both of the third reference voltage source 60 and the second internal voltage generator 61 are operated to produce their outputs only during the test mode. Since the first buffer amplifier 6 is operated with a higher power voltage than in the case of the FIG. 1 prior art, the threshold voltages of its transistors is lowered, extending the range of measurement, and the Shmoo plot of FIG. 4 is obtained prior to the adjustment of the variable resistors of the second reference voltage source 2. | A power supply circuit for an integrated-circuits chip includes variable resistors for establishing an internal voltage for the chip. The internal voltage is variable with the variable resistors and compared by a comparator to a test voltage supplied from an external test circuit. A first buffer amplifier, powered by an externally supplied voltage, amplifies the output of the comparator to produce output voltages of opposite polarities. A second buffer amplifier, powered by the externally supplied voltage, amplifies the output voltages of the first buffer amplifier to supply an output voltage to the test circuit. In a modified embodiment, a second voltage source is additionally provided to establish a second internal voltage higher than the internal voltage produced by the first reference voltage source. The first buffer amplifier is powered by the second internal voltage, instead of by the first internal voltage, to amplify the output of the comparator. | 6 |
RELATED APPLICATIONS
This is a continuation of copending parent application Ser. No. 09/744,681, nationalized 29 Jan. 2001, the entire contents of which are hereby incorporated by reference, which application was the national stage under 35 USC 371 of PCT/IL99/00403, filed 22 Jul. 1999.
FIELD OF THE INVENTION
The present invention concerns environmentally friendly processes and compositions for preventing qualitative deterioration and quantitative loss of plant matter and foodstuffs, during all stages of storage and handling, including pre and post harvest, pre and post planting, distribution and marketing, as well as for preventing sprouting, rooting and promoting fecundity of certain plant matter. The processes and compositions of the present invention can also be used to reduce and eliminate harmful organisms and substances from earth, other growth media and substrates, equipment, materials, water, spaces and surfaces.
BACKGROUND OF-THE INVENTION
The present invention involves processes and compositions utilizing primarily aqueous hydrogen peroxide for preventing qualitative and quantitative loss of foodstuffs and plant matter during storage and/or handling of such. foodstuffs and plant matter. The present invention also involves a process for effecting Epical Dominance Breakdown in certain plant propagation material and as a consequence achieving a number of notable benefits, including storage stability of the plant propagation material itself and higher product yields, when such material is planted. The processes and compositions of the present invention can also be used to reduce and eliminate harmful organisms and substances from earth, other growth media and substrates, equipment, materials, water, spaces and surfaces.
Hydrogen peroxide itself is an environmentally friendly material because its decomposition products are water and oxygen. Its use in the present invention in optional combination with other components, is limited to such compositions and processes that are environmentally friendly, either because the other components are in themselves environmentally friendly or they are used in quantities that do not constitute a danger to individuals or to the environment.
Deteriorative losses of foodstuffs and plant matter during growing, storage and handling is a high priority global problem of considerable social, economic and political importance. Quantitative and qualitative losses during all stages of foodstuff and plant matter growing, storage and handling, impacts first and foremost on the possibility to sustain a reasonable nutritional level and life quality for the earth's inhabitants. Consequently, processes and compositions that can contribute significantly to quantitative and qualitative loss prevention, are of paramount importance. The present invention concerns effective processes and compositions for such purposes. What is more, the present invention concerns environmentally friendly and energy conserving processes and compositions for such ends.
The process and compositions of the invention inhibits plant matter, such as potatoes, seeds and foodstuffs from sprouting, rooting and pathogenic attack and decay, so that such material can be stored under conditions of high relative humidity (70-99+%), optimized to prevent weight loss by dehydration, during storage, for even extended periods of time. The process and compositions of the invention also allow storage under conditions of relatively high temperatures, i.e., low degree of refrigeration, in combination with high relative humidity. This facilitates significant energy savings relative to lower temperature refrigeration, usually required for foodstuff and plant matter storage, particularly under conditions of high relative humidity.
These factors are of prime importance in the post harvest period. But they are also significant in all stages of foodstuff and plant matter growing, storage and handling.
In the event of extended storage period, it can be advantageous to treat the stored plant matter or foodstuff every few weeks with the inhibiting solution and according to the process of the invention. In addition, in the interim period between such treatments, the stored plant matter or foodstuff can be maintained in an aseptic environment by providing a lower level dosage on a more frequent or regular basis, by solutions and treatments that provide the aseptic environment in conjunction with the additional humidity. The process of the invention is readily adaptable to be implemented during transit of the treated matter. This is of considerable significance, since agricultural products, particularly food products, are produced by and large, only during limited seasons of the year. In order for such food products to be available for human and animal consumption during all or at least extended seasons of the year, they must be stored under conditions that minimize losses by dehydration, pathogenic decay, sprouting, rooting and the like, while maintaining organoleptic qualities and preventing other processes that adversely affect their quality.
It is also of the utmost importance that methods and materials employed in extending the effective storage lifetime of perishable foodstuffs and plant matter, should not be detrimental to the consumers' personal health and welfare, nor cause any harm to the environment. While one specific application of the present invention so far, has been to extend the effective storage quality and lifetime of potatoes, it is self evident that the same or similar processes and materials can be used to extend the effective storage quality and lifetime, increase crop yields and specifically increase crop yields on a commercial scale, of plant material and foodstuffs in general. This applies not only to similar vegetable food crops, such as, sweet potatoes, carrots, onions, radishes, garlic, etc., but the process and compositions of the invention can be used to good advantage to extend the storage quality and lifetime of potato seeds, sweet potato propagation material, as well as bulbs, including flower bulbs and tubers. The present invention can also be suited to inhibit sprouting in seeds and grains. Furthermore, the process of the invention imparts extended shelf life stability, to all sorts of foodstuffs and plant material, including fruits and vegetables, so treated.
A reference that deals at length with the specific topic of potatoes as an example, and some of its related problems is; Smith, O., POTATOES: Production, Storing, Processing , The Avi Publishing Co., Inc., Westport, Conn.
The current total global yield of potatoes is estimated to be in the vicinity of 300 million tons per annum. It is both a basic food staple, because of its inherent nutritional value, being rich in carbohydrates and other nutrients and at the same time is frequently prepared for quick snacks as French fries or chips. It is even used in gourmet dishes, wherein product quality, taste and texture are more critical. Since the conditions under which potatoes grow, prevail only in certain seasons of the year in the various regions of the globe in which they are grown, the issue of preventing qualitative and quantitative losses during storage or during inter regional trade, is vital to those involved with potato growing, storage, trade and consumption. Dehydration during storage is one of the major reasons for weight loss in absolute quantitative terms. At the same time, it contributes to qualitative deterioration in the potatoes themselves. The amount of weight lost by dehydration, during storage is determined by the characteristics of the specific potato varieties involved and by the storage regime. An environment with high relative humidity, prevents water loss by evaporation from stored potatoes. Whereas an environment with low relative humidity can take up a substantial amount of moisture from stored potatoes. Water loss by dehydration of stored potatoes is weight loss of the stored product and consequently a direct economic loss.
Moreover, water losses from stored potatoes can adversely affect their quality in other ways. Tubers that have lost significant quantities of water by dehydration, are softer than tubers that have been stored under conditions that reduce or prevent such water losses. They are also more subject to bruising and consequently more vulnerable to pathogenic attack and decay.
To prevent weight loss due to dehydration, potatoes are normally stored under conditions of high relative humidity. Such conditions, unless certain counter measures are invoked, are known to promote sprouting and rooting of the stored potatoes, undesirable processes that contribute to the deterioration in potato quality and sometimes even total loss of the potatoes. In addition, high humidity environment frequently favors the growth of pathogens that both contribute to and promote qualitative and quantitative losses.
The materials in use up to now to prevent such undesirable consequences of storage include, isopropylphenylcarbamate (IPC), chloro isopropylphenylcarbamate (CIPC) (see for example, Hajslova, J., and Davidek, J., 1986, Sprout inhibitors IPC and CIPC in treated potatoes, Nahrung Food, 30, 75-79), maleic hydrazide (see for example, Yada, R. Y., Coffin, R. H., Keenan, M. K., Fitts, M., Duffault, C. and Tai G. C. C., 1991, Effect of maleic hydrazide on potato yield, sugar content and chip color etc., Amer. Potato J., 68, 705-709), 1,2-dihydro-3,6-pyridazinedione and 2,3,5,6,-tetrachloronitrobenzene (TCNB).
Use of CIPC is the most widespread practical method today of keeping potatoes sprout free during storage. However, the use of this sprout inhibitor creates a number of problems. These include, suppression of suberization and periderm formation, requiring as a consequence special additional treatment after the curing process. Moreover, CIPC leaves toxic residues on the tubers to which it is applied. The ambient storage temperature required to inhibit sprouting during potato storage is 2-4° C. Maintaining this relatively low temperature requires significant energy expenditure and cost. There is also a tendency for starches to be converted to sugars at temperatures below 9° C. and thereby degrade the taste characteristics of the potatoes, particularly potatoes intended for industry. Such potatoes suffer therefore from lower consumer acceptability, while for some industrial application, such potatoes are totally unacceptable. Moreover, CIPC has to be volatilized at relatively high temperatures (170°-180° C.) before introduction into the storage chamber, thereby effecting an undesirable burden on the refrigeration system and an extra expenditure of energy.
For potatoes harvested during the normal potato harvest season, two options are available to prevent sprouting and rooting. One involves maintaining storage temperatures between 2-4° C. The other allows storage at higher temperatures, but requires treatment with CIPC and other chemicals that inhibit sprouting. In the case of late harvest potatoes, storage at temperatures even as low as 2-4° C., does not provide assurance of effective sprouting inhibition. In such cases, even supplemental treatment with CIPC, does not assure effective sprouting inhibition. On the other hand, the process of the present invention, does provide effective sprouting and rooting inhibition over a wide temperature range.
While the usual storage temperatures employed with CIPC treatment are within the range 7-8° C., the process of the invention has been found to impart effective sprouting and rooting inhibition over a wide range of temperatures. This includes the current relevant range of storage from 2-10° C. It also includes a wide range of ambient temperatures. It should be emphasized once more, that the possibility of allowing higher storage temperature, provides a way of achieving substantial energy savings with economic, qualitative, quantitative and ecological benefits. Furthermore, certain embodiments of the present invention facilitate adjustment of the carbon dioxide-oxygen gas balance in the storage rooms, thus preventing “black-heart” deterioration in the stored potatoes. CIPC and similar based treatment processes do not inherently involve such gas balance adjustments.
It should be pointed out that CIPC is not effective at temperatures of 5° C. and below. In various circumstances, such as late harvest, sprouting can occur at such temperatures. However, the process and compositions of the present invention, is effective in inhibiting sprouting, even at temperatures of 5° C. and below. Experiments have shown that the interval between successive treatments for effective control by the process and compositions of the present invention, can be prolonged to as long as two to six months, under these conditions.
The wide temperature range that is suitable for storing plant matter and foodstuffs treated by the process and compositions of the present invention, also provides greater flexibility to accommodate a relatively wide variety of different conditions encountered in various facilities and environments. The process of the invention can also be implemented while the plant matter or foodstuff is being transported, thus providing a means for inhibiting deteriorative processes in transit, but also conserving time.
CIPC has a number of additional deficiencies that the process of the present invention overcomes. CIPC is systemic to tubers, fruits and food stuffs treated with it. That is to say it penetrates into the bulk of such tubers, fruits and food stuffs. As a consequence, this results in a number of limitations, that include;
(1) regulations that prohibit use of CIPC, to treat certain food materials;
(2) potatoes and similar foodstuffs that been treated with CIPC must undergo a waiting period of at least a month or two before they are marketed, in order to allow the CIPC to decompose;
(3) a storage room or bin in which CIPC treatment took place, is prohibited from being used for food or seed storage;
(4) application of CIPC requires special equipment that is expensive to acquire and maintain, a high and specific temperature to transform the liquid into a gas, and constant supervision of a skilled technician during the entire period of operation;
(5) CIPC attacks plastic, leaves a black, difficult to remove, layer on the surface of the storage room and leaves active residues in the walls for a period of years.
(6) CIPC has to be volatilized at high temperatures before introduction into storage chambers, thereby adversely affecting the temperature balance therein
All the above mentioned disadvantages of CIPC are eliminated when the process of the present invention is used instead of CIPC treatment. This is because the decomposition products of the compounds used in the present invention are harmless. For the most part, they consist of water and oxygen, with merely trace, practically undetectable quantities of other optional components, when used. In certain embodiments, it also provides for carbon dioxide-oxygen gas balance adjustment, thereby inhibiting “black-heart” deterioration of stored potatoes.
Finally, in certain countries the use of CIPC is either restricted or in the process of being restricted and even prohibited. The other materials mentioned above aside from those of the present invention, do not constitute attractive alternatives to the use of CIPC, because of similar or other deficiencies.
Hydrogen peroxide is a well known non-polluting oxidizing agent. A comprehensive article summarizing its production, uses and other features is presented in Kirk-Othmer, Encyclopedia of Chemical Technology-4th Edition, Vol. 13, pp. 961-995. The said article and its bibliography are included herein by reference. The known uses for hydrogen peroxide described in the Kirk-Othmer article include water treatment, disinfection and sterilization of contact surfaces of food packaging. The use of hydrogen peroxide for space decontamination, was also indicated as holding promise. The bibliography also cites various patents that involve stabilized hydrogen peroxide compositions. Such a composition containing silver salt or complex is described in WO 96/18301, while U.S. Pat. No. 4,915,955 concerns a stabilized silver salt compound or colloid for mixing with hydrogen peroxide to produce effective disinfectants. No mention is made in the article concerning the use of hydrogen peroxide or its compositions for treating foodstuffs or plant material.
The use of hydrogen peroxide in combination with silver ions for disinfection of water is also described in Shuval, H., et al, Water Sci. Technol., (1995), 31(5-6, Health-Related Water Microbiology 1994), 123-9 and in Shuval, H., et al, Water Supply, (1995), 13(2 IWSA International Specialized Conference on Disinfection of Potable Water, 1994), 241-51.
While occasional and sporadic reports in technical and sales promotional literature and meetings have indicated that hydrogen peroxide treatment can be beneficial for foodstuff and plant matter conservation, a recent summary presented at a meeting of the European Association for Potato Research that took place on Mar. 25-29, 1998, at Aberdeen, Scotland, indicated that such treatments are less effective than available alternatives. See, for example, Clayton, R. C., and Black, S., POTATO SEED STORE HYGIENE: CLEANING, DISINFECTION OR BOTH? Presentation at meeting of European Association for Potato Research, Mar. 25-29, 1998, at Aberdeen, Scotland.
Among publications that one might note as indicating possible benefits from hydrogen peroxide treatment of foodstuffs and plant matter, one can cite the following:
Afek, A., et al, NEW APPROACHES FOR INHIBITION OF SPROUTING AND REDUCTION OF WEIGHT LOSS DURING POTATO STORAGE, Abstracts of Conference Papers, Posters and Demonstrations, 13th Triennial Conference of the European Association for Potato Research, July 14-19, Veldhoven Netherlands and Postharvest, Taupo, New Zealand, August, 1996. This publication describes an ultrasonic technique for treating potatoes in storage with a solution containing 25% ethanol and 0.3% of a commercial concentrate containing hydrogen peroxide and silver ion. While the efficiency of the treatment in sprout inhibition was reported to be comparable to the standard CIPC treatment, no indication was given of effectiveness of treatment with aqueous hydrogen peroxide without the ethanol.
A sales promotion brochure for a preparation with the name Virosil-Agro, claims that the preparation is effective in preventing post-harvest deterioration in a large variety of fruits and vegetables. The preparation itself is described as “a multicomponent complex formulation containing hydrogen peroxide and silver in cationic form.” The forms of application do not include “Dry Fog”.
In an article in Hebrew by Nir, A. and Heller, D., in HaSadeh, Vol. 74, No. 12, pp. 1326-7, mixed results are reported for the disinfection of hatching eggs with a hydrogen peroxide preparation applied with an ultra-sonic fogger. No explanation is provided for the lack of consistency in results, although good results were reported for the more recent series of tests.
The mixed and inconclusive results observed so far for application of preparations containing hydrogen peroxide to foodstuffs and plants can probably be rationalized as follows:
Hydrogen peroxide is a strong oxidizing agent. It is also a strong disinfectant, effectively eliminating or at least reducing a wide variety of pathogens, including pathogens that cause decay. Being however at the same time a strong oxidizing agent, it can also cause damage surface tissues and protective peels and coatings of foodstuffs and plant matter, thereby making them more vulnerable to pathogen penetration. Consequently, reluctance so far to adopt environmentally friendly, hydrogen peroxide based processes and compositions for treating foodstuffs and plant matter to prevent qualitative and quantitative losses during storage and handling, can be attributed to a large extent to the absence of reliable processes and compositions for this purpose, that provide consistently effective results.
Consequently, it is an object of certain aspects of the present invention to provide a process and/or hydrogen peroxide containing compositions that allows plant matter and foodstuffs to be stored under conditions of high relative humidity and high relative temperature, while inhibiting detrimental processes that cause deterioration in quality that are frequently promoted by conditions of high relative humidity and temperature. Thus it is possible to gain the various benefits of high humidity and temperature storage without incurring detrimental consequences, frequently effected by storage of foodstuffs in a high humidity and high relative temperature ambiance. The sprouting, rooting and “black-heart” formation of potatoes or similar tubers during storage, can be cited as examples of detrimental processes that occurs during storage, particularly in a high humidity and high relative temperature ambiance.
Its is also an object of certain aspects of the present invention to provide a treatment process and/or compositions that prevent sprouting, rooting and “black-heart” formation of potatoes, other tubers, bulbs, seeds, grains, onions and other food and plant propagation material, particularly under conditions of high humidity and relatively high temperature storage. The said process also allows for convenient adjustment of carbon dioxide-oxygen gas balance, thereby inhibiting “black-heart” deterioration in potatoes.
It is also an object of certain aspects of the present invention to provide a process and/or compositions that result in energy savings during storage and handling of foodstuffs and plant matter.
It is also an object of certain aspects of the process of the present invention to apply a treatment process and/or compositions on seeds and plant propagation material that reduce losses from harvest until sowing, inhibit sprouting, protect seeds without loss of water necessary for growth, allow seeds to be maintained in an aseptic condition, so that they do not transmit infections and diseases, from country to country, to neighboring seeds, to the harvests they will produce or the earth in which they are planted.
It is another object of certain aspects of the present invention to provide processes and/or compositions that effect and promote Epical Dominance Breakdown, thereby inhibiting premature undesirable sprouting, but ultimately promoting enhanced sprouting capability, and in addition promoting and enhancing part of or all the following benefits and advantages, in appropriate plant matter, e.g. in potatoes
(1) More stems per tuber relative to an untreated control;
(2) greener and richer foliage;
(3) more uniform growth height;
(4) more tubers per maternal tuber;
(5) higher yields in kg/square meter;
(6) greater uniformity in the size distribution of the harvest product, particularly in standard sizes for industry, for marketing and for seeds;
(7) the pre-treatment in accordance with process and compositions of the invention preserves the maternal tuber from deteriorative processes that would ultimately contaminate the yields and
(8) because the effects of the treatment on seeds is beneficial, total flexibility is provided to the storers of potatoes, to market his produce to industry or/and consumer markets and/or for seed, all in accordance with market conditions. This can be done immediately after treatment, without having to wait a month, as required after treatment with CIPC.
The treatment process and/or compositions provided by the invention are total substitutes to the treatment and compositions in use at present for seed matter before export and/or before actual sowing. Furthermore, it is friendly to man and the environment, simple and economical to implement, The most common material in use until recently and still in use in some countries for this purpose, is ethyl methyl mercury chloride. This material contains a high concentration of organic mercury and has therefore been prohibited for use in most of the countries of the world. This is because it is dangerous to the health of the user, and contains a toxic metal that contaminates the ground and aquifers.
The new treatment process and/or compositions of the present invention are more efficient. They possess additional beneficial and superior properties. They are friendly to the user and the environment, in comparison to other alternative seed treatments with various sorts of fungicides and fumigation with formaldehyde.
It is an additional object of certain aspects of the present invention to provide a process and/or compositions for preventing modes of qualitative and/or quantitative losses of potatoes during storage, for example, by decay caused by infection with microorganisms, fungi, algae, yeasts, molds and viruses.
It is yet another purpose of certain aspects of the present invention to provide a storage process for storage of plant matter and foodstuffs that prevents qualitative and quantitative losses during storage, by undesirable microbiological or biochemical processes of the foodstuff itself, including when such processes are effected and/or promoted by high humidity and high temperature storage conditions.
It is also an object of certain aspects of the present invention to provide processes and compositions that can be used to reduce and eliminate harmful organisms and substances from earth, equipment materials, spaces and surfaces
Moreover, it is an important object of certain aspects of the present invention to achieve the above purposes in a simple way, that is safe to use, non-toxic, odorless, without hazardous residues and/or side effects, compatible with the environment and that does not leave any undesirable chemical residues in the materials or water, earth, other growth media and substrates, or on equipment, materials, water, spaces and surfaces exposed to the treatment by the process and compositions of the present invention, or endanger the health of operators implementing the process or handling the compositions or the foodstuffs treated by them. The process and compositions of the present invention are cost effective.
SUMMARY OF THE INVENTION
Percentages throughout the specification indicate weight by weight percentages.
In accordance with a preferred embodiment of the present invention, there is provided an environmentally compatible process for treating plant matter and foodstuffs, during storage, distribution and marketing, preplanting, growing, and pre and/or post harvest, to increase yields, eliminate health hazards, impart storage stability, extend shelf life and inhibit premature sprouting, rooting, germination, blossoming, decay, “black-heart” formation, pathogenic losses and other processes causing losses in quality and/or quantity of said plant matter and foodstuffs, said plant matter and foodstuffs including tubers-such as potatoes, bulbs, seeds grains and other germinating matter or items, plant vegetative propagation matter or items, as well as various fruits and vegetables including solanaceous fruits and vegetables, by treating the said plant matter or foodstuffs, during storage and/or distribution and marketing, preplanting and/or during pre and/or post harvest with an effective aqueous dosage comprising an effective concentration of hydrogen peroxide and optionally comprising, an effective dosage of one or more additional components selected from the following types of substances:
(i) effective-trace concentrations of dispersed metals or metal ions; (ii) effective concentrations of other and/or additional hydrogen peroxide activators, synergists and promoters; (iii) effective concentrations of hydrogen peroxide stabilizers and modifiers; (iv) effective concentrations of pH regulators; (v) effective concentrations of organic and/or inorganic additives,
wherein the effective concentration of hydrogen peroxide, time of treatment and form of application are such as to prevent such plant matter and foodstuffs quality and/or quantity loss, but at the same time not so high as to cause or induce damage to the plant matter and foodstuffs themselves.
In accordance with another preferred embodiment of the present invention, there is provided a process for preventing premature sprouting and enhancing the productivity in plant growth material, e.g., potatoes, potato tubers, potato growth material or other plant growth material, by effecting Epical Dominance Breakdown in the said potatoes, potato tubers, potato growth material or other plant growth material, comprising treating the potatoes, potato tubers, potato growth material or other plant growth material with an effective aqueous dosage comprising an effective concentration of hydrogen peroxide and optionally comprising, one or more additional components selected from the following types of substances:
(i) effective trace concentrations of dispersed metals or metal ions; (ii) effective concentrations of other and/or additional hydrogen peroxide activators, synergists and promoters; (iii) effective concentrations of hydrogen peroxide stabilizers and modifiers; (iv) effective concentrations of pH regulators; (v) effective concentrations of organic and/or inorganic additives.
In accordance with another preferred embodiment of the present invention, there is provided a composition for treating in an environmental friendly manner, plant matter and foodstuffs, during storage, distribution and marketing, preplanting, growing, and pre and/or post harvest, to increase yields, eliminate health hazards, impart storage stability, extend shelf life and inhibit premature sprouting, rooting, “black-heart” formation, germination, blossoming, decay, pathogenic losses and other processes causing losses in quality and/or quantity of said plant matter and foodstuffs, and promote epical dominance breakdown, said plant matter and foodstuffs including tubers-such as potatoes, bulbs, seeds grains and other germinating matter or items, plant vegetative propagation matter or items, as well as various fruits and vegetables including solanaceous fruits and vegetables, said composition being also suitable to treat earth, other growth media and substrates, equipment, materials, water, spaces and surfaces to reduce and eliminate harmful organisms and substances therefrom, comprising
(a) 0.001% to 50% of hydrogen peroxide (c) 0.001% to 5% of metal ion selected from the group consisting of copper, zinc, nickel, iron, manganese, molybdenum, potassium or combinations thereof and optionally
(i) effective trace concentrations of other dispersed metals or metal ions; (ii) effective concentrations of other and/or additional hydrogen peroxide activators, synergists and promoters; (iii) effective concentrations of hydrogen peroxide stabilizers and modifiers; (iv) effective concentrations of pH regulators; (v) effective concentrations of organic and/or inorganic additives.
In accordance with yet another preferred embodiment of the present invention, there is provided a composition for treating in an environmental friendly manner, plant matter and foodstuffs, during storage, distribution and marketing, preplanting, growing, and pre and/or post harvest, to increase yields, eliminate health hazards, impart storage stability, extend shelf life and inhibit premature sprouting, rooting, ““black-heart”-heart” formation, germination, blossoming, decay, pathogenic losses and other processes causing losses in quality and/or quantity of said plant matter and foodstuffs, and promote epical dominance breakdown, said plant matter and foodstuffs including tubers-such as potatoes, bulbs, seeds grains and other germinating matter or items, plant vegetative propagation matter or items, as well as various fruits and vegetables including solanaceous fruits and vegetables, said composition being also suitable to treat earth, other growth media and substrates, equipment, materials, water, spaces and surfaces to reduce and eliminate harmful organisms and substances therefrom, comprising
(a) 0.001% to 50% of hydrogen peroxide (b) 0.001% to 2.5% of silver ion (c) 0.001% to 2.5% of metal ion selected from the group consisting of copper, zinc, nickel, iron, manganese, molybdenum, potassium or combinations thereof and optionally
(i) effective trace concentrations of other dispersed metals or metal ions; (ii) effective concentrations of other and/or additional hydrogen peroxide activators, synergists and promoters; (iii) effective concentrations of hydrogen peroxide stabilizers and modifiers; (iv) effective concentrations of pH regulators; (v) effective concentrations of organic and/or inorganic additives.
In yet another embodiment of the invention, there is provided an environmentally compatible process for reducing and eliminating harmful organisms and substances from earth, equipment, materials, water, spaces and surfaces by treating the said earth, other growth media and substrates, equipment, materials, water, spaces and surfaces with an effective dosage of a composition comprising an effective concentration of hydrogen peroxide and optionally comprising, an effective dosage of one or more additional components selected from the following types of substances:
(i) effective trace concentrations of dispersed metals or metal ions; (ii) effective concentrations of other and/or additional hydrogen peroxide activators, synergists and promoters; (iii) effective concentrations of hydrogen peroxide stabilizers and modifiers; (iv) effective concentrations of pH regulators; (v) effective concentrations of organic and/or inorganic additives,
DETAILED DESCRIPTION OF THE INVENTION
The preferred range of concentrations or hydrogen peroxide for use in intermittent treatment of foodstuff and plant matter in accordance with the process of the present invention is from 0.001% to 50%, preferably from 0.01% to 20% and more specifically from 0.1% to 15%. The preferred range of concentrations for continuous or short interval treatment is 10 PPM to 40%.
The range of concentrations of dispersed metal and/or metal ion for use in accordance with this invention is from 1 PPB to 5%, preferably from 10 PPB to 10,000 PPM, more specifically from 20 PPB to 2000 PPM and even more specifically from 20 PPB to 1000 PPM. The combination of hydrogen peroxide with appropriate metal ion(s) provides in certain instances a synergistic effect by which the hydrogen peroxide effect is enhanced. In addition, the minute trace residue quantities of the metal ion(s) have been found to have a slower but longer lasting beneficial effect on the prevention of quality and quantity deterioration of foodstuff and plant matter.
The treatment of the treated matter in accordance with this invention can be implemented satisfactorily in various ways. These include, in certain cases dipping the treated matter in the above mentioned solution(s) or spraying the solution(s) onto the treated foodstuff or plant matter. However it should be pointed out that water or condensed water droplets on the surface of foodstuff and plant matter can enhance the proliferation of pathogens and thus have a detrimental effect. This is of particularly concern when it is important to maintain storage conditions of high relative humidity, such as in the storage of potatoes, to prevent material loss due to evaporation and other forms of deterioration induced by a low humidity environment.
Intermittent treatment by means of the process and compositions of the present invention, protects foodstuff and plant matter so treated from adverse effects of condensation of water on the surfaces of the foodstuffs and plant matter, so treated.
The application of the solution In the form of ultra small drops by solution atomizing systems that produce “dry” fogs with particle sizes of less than and up to 1000 microns in diameter, has been found to provide particularly beneficial results. These include compensation for or prevention of water loss, inhibition of sprouting, rot inhibition, less overall losses and higher yields for treated seeds. The beneficial results include epical dominance breakdown. The advantages of small particle size “dry” fog is attributed to the fact that very small particles behave to a large extent like a gas. They facilitate the achievement of very high relative humidity, i.e., even as high as 99%+, without any condensation on the stored matter. Furthermore, the small particles show a very high penetrability into small cracks and spaces. As a consequence, even when potatoes are stored in ordinary stacks or storage sacks, the “dry” fog storage has a high degree of penetrability and accessibility to all points in the stack or sack. This means that even in the simplest and most space compact facilities stored plant matter, such as potatoes and similar items, can be effectively treated to prevent weight loss due to dehydration as well as softening and other deteriorative processes brought about by an inadequate humidity environment.
Another benefit of the “dry” fog is that it allows higher concentrations of hydrogen peroxide and other active ingredients to be used without causing damage to the protective peel or surface of the plant matter so treated. The higher concentration of treating solutions enhances their effectiveness in the rapid elimination of pathogens. When the foodstuff and plant matter is treated by dipping or ordinary spraying, the optimal hydrogen peroxide concentration should be substantially between 0.5%-1.5% and treating time between a few seconds up to a few minutes. When the treatment is applied as a “dry” fog, the hydrogen peroxide concentration may be up to 40% and the time of application from several hours to a number of days.
A further benefit of application by fog is that it allows for convenient adjustment of the carbon dioxide-oxygen balance in the storage room or chamber, thus inhibiting “black heart” deterioration. Preferably, the air to liquid volume ratio in the fog should be between 300:1 and 1200:1, more preferably between 500:1 and 700:1.
In certain aspects and applications, the beneficial effects of the process of the present invention are enhanced by the addition of certain additives to the treatment solution, these additives may include:
Stabilizers and modifiers, such as but not limited to, citric acid, tartaric acid, boric acid, bromic acid, stannates, phosphonic acids etc.
pH Regulators, primarily mineral and organic acids, such as but not limited to phosphoric acid, peracetic acid, hydrochloric acid, sulfuric acid, etc. For optimum effectiveness, the pH should be lower than 6 and preferably between 1-4.
Trace element activators, synergists and promoters, such as but not limited to, dispersions of metal, non-metals or ions (of various valences when appropriate) such as, copper, zinc, nickel, iron, potassium, manganese, silver, chromium, molybdenum, magnesium, boron, phosphorus, iodine, sulfur, citrate, etc.
Organic or inorganic additives, such as but not limited to, peracetic acid, phenol, gelatin, glycerin, sodium azide, polymoxin B, sodium bicarbonate, pectin, salicylic acid, etc.
EXAMPLES
Example 1
In several experiments conducted in a storage room containing hundreds of metric tons of potatoes, a hydrogen peroxide-metal ion solution was introduced with a fogger overnight until a relative humidity level of 80-99% was attained. The potatoes were kept in the storage room for 5 months, during which time fogging treatment was effected 10-50% of the time. The result of the spraying was that losses due to disease were reduced from 8% to 2%, while losses due to dehydration were reduced from 5% to 2%. Therefore the total loss reduction was from 13% to 4.5%, a net average reclamation of 8.5%.
Example 2
The effect of treatment with various solutions of aqueous hydrogen peroxide plus additives at the following concentrations: 0% (control) and 0.1%-30%, by dipping for various lengths of time. Clear-cut sprout inhibition was obtained for bulbs so treated, compared to the control, as well as decay prevention for extended time.
In certain concentrations, an opposite result was obtained, of rot and severe phytotoxic damage to the tubers.
Each of the treatments were repeated five times. Each time involved 50 kilograms of potatoes.
Example 3
Same as Example 2, except that instead of dipping, the solutions were sprayed onto the foodstuff substrate until dripping (high volume).
Example 4
Same as Example 3, except that the spraying onto the foodstuff substrate was low volume.
Example 5
Same as Example 3, except that the spraying onto the foodstuff substrate was ultra low volume.
Example 6
Same as Example 3, except that the spraying onto the foodstuff substrate was by fogging. The gas liquid volume ratio was 600:1.
Examples 7-11
Each of the treatments described in examples 2-6 above were carried out on potato seeds.
Examples 12-16
Each of the treatments described in examples 2-6 above were carried out on wheat seeds, corn (maize), various grains and solanaceous plants. The concentrations of the hydrogen peroxide solutions were varied between 0.1-60%. The species so treated were examined after periods of 7-10 days. In all cases, no sprouting, blossoming and germination were observed.
The same species were examined after varying periods of several weeks to several months. Inhibition of decay was observed
In certain concentrations, an opposite result was obtained, of rot and severe phytotoxic damage to the tubers.
Example 17
750 tons of potatoes of the Desiree variety were stored in each of three cold rooms for six months at 10° C. At an average relative humidity of 97% provided as 3-7 micron droplets, weight loss after this time was only 2.8%. With a regular humidifier and average relative humidity of 92%, the weight loss was 6%. The weight loss in the control. average humidity 85% was 11%.
In addition, the quality of potatoes stored without providing humidity was low because of softening. The firmness of the different batches of potatoes described above were as follows: 64 newtons for 97% relative humidity; 58 newtons for 92% relative humidity and 48 newtons for 85% relative humidity. Potato firmness before storage was 70 newtons.
Example 18
Experiments were conducted to test the effectiveness of treating potato seeds to prevent sprouting, with a “dry” fog comprising, hydrogen peroxide, silver ion and phosphoric acid. After preliminary treatment with the active solution, the storage conditions were maintained at 90% relative humidity and 10° C. The results were as follows:
Concentration
(PPM)
Sprouting (%)
H 2 O 2
Ag ion
one month
two months
three months
0
0
15
27
35
500
1
4
23
31
1,250
2.5
0
3
6
5,000
10
0
2
5
By repeating the above dosage on a monthly basis, it was possible to totally eliminate sprouting for extended periods. However at levels above 25% H 2 O 2 , damage was caused to the peel that developed rapidly to rot
Example 19
Experiments were conducted to test the effectiveness of treating potato seeds to prevent sprouting, with a “dry” fog containing hydrogen peroxide and silver ion. After preliminary treatment with the active solution, the storage conditions were maintained at 90% relative humidity and 10° C. The results were as follows:
Concentration (PPM)
Sprouting (%)
H 2 O 2
Ag ion
Cu ion
one month
two months
three months
0
0
0
15
27
35
500
0
0
8
22
32
500
1
0
4
23
31
500
0
1
6
17
27
500
0.1
0.9
2
13
18
By repeating the above dosage on a monthly basis, it was possible to totally eliminate sprouting for extended periods. However at levels above 25% H 2 O 2 , damage was caused to the peel that developed rapidly to rot.
Example 20
Experiments were conducted to test the effect on yield enhancement of treating potato seeds with solutions containing hydrogen peroxide and silver ion. The potato seeds were initially harvested in late June and put into cold storage at 9-10° C. and 96-99+% RH, initially untreated Approximately one month later, each batch of various potato seed varieties was treated with a dose of a solution containing hydrogen peroxide and silver ion, the ratio of the active ingredients to the potato seeds being 2-5% H 2 O 2 and 40-100 PPM Ag ion on a wt/wt basis. Each batch was treated three more times. The second treatment took place about three and one half weeks after the first treatment and was at the same dosage level. The third treatment was almost four weeks after the second treatment, but the dosage level was reduced by half. The fourth treatment was about three weeks later also at the half dosage level.
The average potato yields in kilogram/square-meter for various potato seed varieties, were as follows:
Treated Potatoes
Untreated Potatoes
After 84 days
2.28 kg/m 2
1.65 kg/m 2
After 94 days
2.56 kg/m 2
2.04 kg/m 2
In addition to the higher yields in weight per unit area, the potatoes that were produced from treated potato seeds had a more uniform size distribution as well as a higher yield of marketable sizes relative to those of the untreated control. In addition, the maternal tubers remained robust and did not deteriorate so that the crop was not contaminated. The problem of maternal tuber deterioration and crop contamination is a basic problem of untreated potato seeds.
General Examples
The following is a number of additional examples of applications of the present new invention in various areas requiring humid and aseptic conditions:
(1) Treatment of hot-house plants and growth products;
(2) Treatment related to growing and marketing of mushrooms and buds;
(3) Treatment in meat storage;
(4) Treatment of eggs for eating or incubation for increasing moisture and preventing infection;
(5) Treatment of incubation spaces, incubation cells and hatching cells.
(6) Treatment of space and equipment in surgical operation rooms;
(7) Treatment of space and equipment in crowded halls and enclosed areas, such as, subway stations, buses, airplanes, ships and the like;
(8) Various treatments of sown earth to prevent ground pollution, instead of methyl bromide whose use is being prohibited.
(9) Storage spaces, greenhouses, hen houses, etc.
While certain embodiments of the invention have been hereinbefore particularly described, it will be apparent to anyone skilled in the art that many modifications and variations may be made, that do not deviate from the main features or spirit of the invention. The invention is accordingly not to be construed as restricted to such embodiments, but rather to its concept, spirit and general scope. | Environmentally friendly processes for prevention of qualitative deterioration and quantitative loss of plant matter and foodstuffs, during all stages of storage and handling, including pre- and post-harvest, pre- and post-planting, distribution and marketing involves the use of H 2 O 2 compositions including Ag and at least one of Cu and Zn ions. The processes can also be used to prevent sprouting and rooting, and to promote fecundity of certain plant matter, and can also be used to eliminate or reduce quantities of harmful organisms and substances from soil, other growth media and substrates, equipment, materials water, workspaces and surfaces. | 0 |
This application is a continuation of application Ser. No. 678,047, filed Dec. 4, 1984, now abandoned.
FIELD OF THE INVENTION
This invention relates to a rotation coupling device.
BACKGROUND OF THE INVENTION
In general, to transmit the rotation of a vehicle transmission to a measuring device such as a speedometer, a rotation device including a flexible shaft inserted through a tubular sheath is used.
Previously, in this kind of rotation coupling device, the clearance between the flexible shaft and the liner of the tubular sheath had to be kept as small as possible in order to suppress the noise of rotation knocking sound and the vibration of the speedometer needle that occurs due to stationary wave vibrations.
However, this technique has the following disadvantages.
1. It is difficult to control the inner diameter of the tubular sheath liner so as to minimize the clearance.
2. Changes of the inner diameter of the liner, when bending occurs, increase the resistance to sliding of the rotating shaft, which in turn shortens the lifetime of the rotating shaft.
3. The amount of lubricant that can be injected inside the tubular sheath is reduced, which also shortens the lifetime of the rotating shaft.
4. It is hard for the shaft to bend, which makes the positioning of the tubular sheath difficult.
SUMMARY OF THE INVENTION
One object of this invention is to resolve the difficulties listed above and to provide an improved rotation coupling device which can prevent the rotating knocking sound and the speedometer needle vibration without need to reduce the clearance between the tubular sheath liner and the rotating shaft.
Another object of the present invention is to suppress the stationary wave vibrations of the flexible rotating shaft and thus to suppress the noise of the rotation knocking sound of the rotating shaft.
In order to accomplish the above objectives, in this invention, special measures are taken at the parts of the tubular sheath corresponding to troughs and ridges, that is to say crests, of the stationary wave vibrations which occur in the flexible rotation shaft inserted through the tubular sheath of the rotation coupling device, whereby such crests of the vibrations are prevented from becoming large.
These and other aspects and advantages of the invention will become apparent by reference to the following detailed description of preferred embodiments when considered in conjunction with the accompanying drawing, wherein like numerals correspond to like elements throughout the drawing.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a partial cutaway front elevational view of a rotation coupling device according to one embodiment of this invention.
FIG. 2 is a simplified cross-sectional view showing stationary wave vibrations of a rotating shaft inside a tubular sheath.
FIG. 3 is an enlarged partial cross-sectional view of the tubular sheath joint as shown in FIG. 1.
FIG. 3A is a sectional view taken along line X--X in FIG. 3.
FIG. 4 is an enlarged partial cross-sectional view of the tubular sheath joint in another embodiment of this invention.
FIG. 5 is an enlarged partial cross-sectional side view of the tubular sheath joint in still another embodiment of this invention.
FIG. 6 shows a partial cutaway front elevational view of a rotation coupling device which is another embodiment of this invention.
FIG. 7 is a partial cutaway perspective view of the part of rotation coupling device in which a vibration suppression ring is built in.
FIG. 8 is a diagonal perspective view of the opened state of a vibration suppression ring.
FIG. 9 is a cross-sectional view of a tubular sheath liner for use in a rotation coupling device of the present invention.
DETAILED DESCRIPTION OF EMBODIMENTS
In the rotation coupling device of this invention shown in FIG. 1, a flexible shaft 1 having an outer diameter of, for example, 3.2 mm is passed through a tubular sheath 2 having, for example, an inner diameter of 4.2 mm and an outer diameter of 7.7 mm. As will be explained in more detail below, a tubular sheath joint 3A is installed at at least one location along the axial direction of the tubular sheath 2. One end of the tubular sheath 2 is coupled to a shaft 5 in a drive shaft 4 and the other end is coupled to a driven member 6.
When rotation is transmitted from the drive shaft 4 on the drive side to the flexible shaft 1, there is a tendency for the bending and deviation from center that occurs at the joint with the drive shaft 4 and the shaft 5 to continuously generate stationary wave vibrations of the rotating shaft 1 at the characteristic frequency of the system.
These stationary wave vibrations involve undulation of the rotating shaft 1 inside the tubular sheath 2, as shown in FIG. 2, and are propagated along the entire length of the rotating shaft 1 from the drive shaft 4 to the driven member 6. The rotating shaft 1 strikes the inner wall or liner of the tubular sheath 2 producing a knocking sound, which is noisy, and also causing the speedometer needle to vibrate.
In addition, it also sometimes happens that these stationary wave vibrations are also generated at the joint with the driven member 6 and propagated back toward the drive shaft 4.
Some crests of stationary wave vibrations generated in this manner are shown and indicated by the arrows in FIG. 2. In this invention, at every location where a wave crest occurs (at intervals of 1/2 wave length), a tubular sheath joint 3A is installed in the tubular sheath 2. By forming joints which reduce the inner diameter of the tubular sheath inner wall at these points, the growth of the crests of the vibrations of the rotating shaft 1 at these points is limited and absorbed, and the stationary wave is weakened and suppressed.
As shown in FIG. 3, tubular sheath 2 comprises an outer tubular cover member 2A and an inner liner 2B. The outer tubular cover member 2A may be made of resin material. Tubular sheath 2 is cut at a location where a wave crest of flexible rotating shaft 1 occurs and divided into two tubular portions. A tubular sheath joint 3A is provided to join the tubular portions of tubular sheath 2. Tubular sheath joint 3A comprises a generally cylindrical body 7 with tapered edges and a radially inwardly protruding annular member 7A formed at a central position on the inner surface of cylindrical body 7. As shown in FIGS. 3 and 3A, protruding member 7A has an inner diameter smaller than the inner diameter of inner liner 2B so as to oppose flexible rotating shaft 1 through a slight gap therebetween. As a result, the crest of a stationary wave vibration of the rotating shaft, i.e the antinodal point of the stationary wave, is regulated by protruding portion 7A.
In order to secure tubular joint 3A onto tubular sheath 2, the ends of the tubular sheath portions are respectively inserted into opposite ends of cylindrical body 7, and the cylindrical body is bonded to the outer tubular cover member 2A of the tubular sheath by heat welding. For example, the total length of cylindrical body 7 may be 30 mm, and the thickness 7.8 mm at the center in this embodiment. Assuming the dimensions given above for the flexible shaft and sheath, the inner diameter of the annular protruding member may, for example, be 4 mm.
In addition, as shown in FIG. 4, to eliminate the unevenness at the cut edge surface of the outer tubular cover member 2A, a buffer means 8 is installed through a washer 9 inside the joint cover 7 over the cut so as to contact the rotating shaft 1.
This buffer means 8 which is made of, for example, felt suppresses the vibration of the rotating shaft 1. Not only that, but it absorbs the small vibrations propagated from the drive shaft 4 to suppress the propagation of vibrations to the tubular sheath 2.
FIG. 5 shows one embodiment of such a joint cover 7 having the opposite ends thereof raised.
In the embodiment shown in FIG. 6, as shown in more detail in FIG. 7, cylindrical vibration suppressing rings 3B having an inner diameter larger than the outer diameter of the rotating shaft 1, are installed inside the tubular sheath 2 so as to contact the tubular sheath inner liner 2B at the crests of the stationary wave vibrations, that is to say, at half-wavelength intervals. This method is appropriate when the outer tubular cover member of the tubular sheath 2 has a braided copper wire component 11.
The vibrations of the rotating shaft 1 are suppressed and absorbed when the rotating shaft 1 at the crests thereof contacts with the vibration suppression rings 3B, and thereby the stationary wave is also suppressed. In addition, lubricant accumulates in the spaces between these vibration suppression rings 3B, which helps the rotating shaft 1 last longer. These vibration suppression rings 3B do not interfere with the rotation of the rotating shaft 1.
The vibration suppression rings 3B are made of metal or plastic. Before installation inside the tubular sheath 2, they are formed as flat plates as shown in FIG. 8. It is desirable for one side which will be the inside after the ring is curled up to be covered with, for example, short nylon bristles 12 to increase the vibration suppressing effect.
The dimensions of each vibration suppression ring could be, for example, length 10 mm, outer diameter 4.3 mm and thickness 0.2 mm to conform to the other dimensions given of the rotating shaft above. The short bristles could, for example, be 0.3 mm long and 1.5 denier in thickness with a density of at least 20 bristles/mm 2 .
If the liner member 2B of the tubular sheath 2 is made with a hexagonal cross-section, as shown in FIG. 9, lubricant such as grease can accumulate in the corners, increasing the lifetime of the rotating shaft 1 still further.
In operation, in a rotation coupling device with the configuration of this invention, when rotation is transmitted from the drive shaft 4 to the flexible rotating shaft 1, there is a tendency for stationary wave vibrations to occur in the flexible rotating shaft 1, but these vibrations are suppressed by the tubular sheath joint vibration suppression rings, preventing noise and speedometer needle vibrations due to the rotation knocking sound of the rotating shaft. In particular, in a case such as in a front wheel drive vehicle in which the rotating shaft is short and it is easy for transmission vibrations to be propagated, the vibration suppression effect is great and noise is considerably reduced.
The existence of the vibration suppression rings 3B (or, in the case of tubular sheath joints 3A, the existence of the buffer means 8) increases the accumulation of lubricant, which extends the life of the rotating shaft.
Finally, in the device of this invention, the following point is worthy of attention. Since small-diameter parts are made separately and then installed one at a time, it is easy to control their dimensions. The effective thickening of the tubular sheath walls reduces the variation in inner diameter due to bending. In addition, since the tubular sheath joint covers are tapered in an umbrella shape, the tubular sheath joints and the tubular sheath bend with nearly the same radius of curvature.
While preferred embodiments of this invention have been shown and described, it will be appreciated that other embodiments will become apparent to those skilled in the art upon reading this disclosure, and, therefore, the invention is not to be limited by the disclosed embodiments. | Stationary wave vibrations in a rotation coupling device comprising a rotating shaft disposed within a tubular sheath are suppressed by providing the sheath at the crests of the stationary wave with inwardly projecting vibration suppressing device, such as tubular sheath joints with inward protrusions or vibration suppressing rings disposed inside the sheath, which reduce the inner diameter of the sheath at the wave crests compared to the inner diameter of the rest of the sheath. | 8 |
BACKGROUND OF THE INVENTION
The present invention provides apparatus for measuring the electrical impedance of a tissue sample.
It is known that certain medical conditions can be monitored by measuring the impedance of a patient's tissue. This can be done by applying electrodes to the tissue through which a low voltage current can be passed through the tissue. It is known to use this technique to detect abnormal cell growth which can be indicative of a tumour. Electrical impedance spectroscopy has been used to identify premalignant changes in tissue samples, especially to identify the pre-cancerous phase of cervical cancer, known as cervical intraepithelial neoplasia (CIN).
Impedance measurements can be used to detect other conditions of a patient. For example, onset of labour is accompanied by changes in tissue impedance which can be identified by such measurements.
Electrical impedance spectroscopy measures the electrical impedance spectra of superficial tissues, such as for example cervical epithelium by placing an electrically conductive probe in contact with the tissue sample. Biological tissues have an electrical impedance which is dependant on the frequency of the current passed through the tissue. The biological tissues contain a number of components, such as a nucleus and a cytoplasm which have both resistive and capacitive properties. It is known that in cancerous and pre-cancerous tissues there is a significant change in the size of the cell nuclei, in the shape of the cells and in the arrangement of cells which form the tissue. These changes affect the electrical impedance of the tissue sample and therefore electrical impedance tomography can be used to detect significant changes in cell structure and therefore diagnose patients suffering from CIN.
The magnitude of the electrical impedance and the dependence of the electrical impedance on frequency of a tissue sample have been found to be indicative of the tissue composition. It has been found that different tissue structures are associated with different frequency bands within an electrical impedance spectrum.
It has been found that at low frequencies (less than about 1 kHz) the current is unable to pass through the cells due to the capacitance of the cellular membrane and charge accumulation occurs at large membrane interfaces. At intermediate frequencies, such as in the region of about 1 kHz to 1 MHz (also known as the β dispersion region) cell structures are the main determinant of tissue electrical impedance and current begins to penetrate the cell membranes. However, at higher frequencies (greater than about 1 MHz) the current is able to pass through the cells and the nuclei and at even higher frequencies (>1 GHz) the molecular structure is the determining factor contributing towards the electrical impedance of the tissue sample.
Within the lower part of the β dispersion range, low frequency current can be considered to be passing through the extracellular space within the tissue sample. The current passes around the cells and the resistance to the flow of the current will therefore depend upon the cell spacings and how the cells are arranged. At higher frequencies however current can penetrate the cell membranes and pass through both the intracellular and extracellular spaces. The current will therefore pass into the cells and the resistance to current flow will be determined by intracellular volume and possibly the size of the nucleus.
It is known that by measuring the electrical current patterns produced by a tissue sample over a range of frequencies, and applying an inverse modelling procedure, electrical parameters resulting from the tissue structure may be determined. The intracellular resistance of a given tissue sample has been found to be significantly affected by the relative sizes of the nucleus and the cell. It has therefore been found that the electrical impedance of tissue samples can be used to distinguish between tissues having different nuclear volume to cytoplasm volume ratios. Tissue samples having a higher ratio of nuclear volume to cytoplasm volume may be indicative of pre-cancerous tissues. The application of electrical impedance measurements using a probe which bears four electrodes on an end face in cervical cytology is disclosed in Electronics Letters, 36 (25) 2060-2062 and in The Lancet, 355: 892-95.
For example, it is known that in cervical tissues the major changes in the pre-cancerous stages are the gradual breakdown of superficial cell layering and the increase in the size of the cell nuclei. These changes will therefore have an effect on the electrical impedance of a tissue sample at intermediate frequencies and therefore electrical impedance can be used to diagnose the presence of pre-cancerous tissues.
The electrical impedance of a tissue sample is measured to give mean values of electrical impedance at a number of frequencies. This data, forming an electrical impedance spectrum, is then fitted by a least square deviation method to a Cole equation as discussed in US-2003/0105411 of the form:
Z = R ∞ + ( R 0 - R ∞ ) ( 1 + ( jF / F c ) ( 1 - α )
to give estimates of R 0 , R ∞ and F c . R 0 and R ∞ are the electrical impedances of the tissue sample at very low and very high frequencies respectively, F c is a frequency and α is a constant. α increases with the inhomogeneity of the tissue however it can be assumed that α is zero to improve the accuracy in the estimation of F c . In this case an equivalent electrical circuit consisting of a resistor R placed in parallel with a resistor S and capacitor C in series will have an impedance Z, given by the above equation, where:
R
0
=
R
,
R
∞
=
RS
R
+
S
,
F
c
=
1
2
π
C
(
R
+
S
)
Parameters R, S and C can therefore be determined from the fitted Cole equation. Because the probe was calibrated in saline of known conductivity, R and S are inversely proportional to conductivity and have the units of Ωm. R and S can therefore be related to the extracellular and intracellular spaces respectively. C is related to the cell membrane capacitance and is given in units of μF·m −1 .
WO-01/67098 discloses the use of an electrically conductive probe for measuring the electrical impedance of tissue samples comprising a tetrapolar electrode arrangement positioned at the probe tip for the in vivo measurement of the electrical impedance spectra of a tissue sample. Subject matter disclosed in that document is incorporated in the specification of the present application by this reference.
SUMMARY OF THE INVENTION
Known electrical probes have certain disadvantages. The probe must be sterilised after use, for example by cleaning chemicals. The sterilisation of the probes is both costly and time consuming. The screening unit must therefore obtain a significant number of probes so that while used probes are in the process of being sterilized there are enough sterilized probes available to screen the desired number of patients.
WO-98/41151 discloses a discardable, sterile sheath for use on a probe that performs both optical and electrical measurements. The sheath comprises electrodes on the tip of the sheath in close proximity to an optical window provided by the sheath. The electrodes on the tip of the sheath are close to the optical window to ensure that both optical and electrical measurements can be performed on the same area of tissue. The internal probe comprises electrical connections which make electrical contact with the electrodes in the sheath. However, any failure in electrical contact between the electrical connections of the probe and the electrodes in the sheath will lead to false readings which may lead to the incorrect diagnosis of a patient. There is therefore an undue burden placed on the operator in connecting the probe sheath to the probe correctly so as to provide an accurate measurement of the electrical impedance of the tissue sample. The provision of electrodes on the disclosed sheath also means that it is expensive to manufacture.
The present invention provides apparatus for measuring the electrical impedance of a tissue sample, which comprises:
(a) an elongate probe having electrodes towards one end thereof through which an electrical signal is transmitted between the apparatus and tissue in contact with it; and (b) a sheath comprising an elongate tubular body having a closed end and an open end and defining an internal cavity, in which the end of the probe on which the electrodes are provided can fit into the cavity, and in which at least a portion of the sheath is formed from a material which when contacted with a tissue sample is capable of providing a conductive path through the sheath between the electrodes and the tissue sample, and in which the resistivity of the material when contacted with the tissue sample is greater than the resistivity of the tissue sample.
The sheath can be formed at least partially from a non-electrically conductive polymeric material with a porous structure such that it can be impregnated with body fluid when contacted with a tissue sample and provides an ionically conductive path through the sheath between the electrodes and the tissue sample.
The sheath can be formed at least partially from a material which is inherently electronically conductive. For example, it can be formed from a material which is loaded with a conductive filler. Examples of suitable conductive fillers include certain carbon blacks.
Preferably, the ratio of the resistivity of the material of the sheath (when impregnated with body fluid if the conductivity through the sheath relies on ionic conduction in the body fluid) to the resistivity of the tissue sample is at least about 10, more preferably at least about 50, especially at least about 100, more especially at least about 500, for example at least about 1000.
It is known that the typical electrical resistivity of a tissue sample is about 1 Ωm. Preferably, at least a portion of the sheath is composed of a material which when contacted with a tissue sample has a resistivity of greater than about 1 Ωm, preferably greater than about 500 Ωm, for example greater than about 1000 Ωm. Preferably, at least a portion of the sheath is composed of a material which when contacted with a tissue sample has a resistivity of less than about 5000 Ωm, more preferably less than about 4000 Ωm, for example less than about 2500 Ωm.
A probe can be calibrated by placing them in contact with solutions of known conductivity and obtaining conductivity measurements. The calibration can take into account factors such as the resistivity of the material of the sheath.
Suitable materials for the sheath have been found to have an effective pore size of at least about 0.5 nm, more preferably greater than about 2 nm, for example about 3 nm. Preferably, the effective pore size of the material of the sheath is not more than about 15 nm, more preferably less than about 10 nm, for example about 5 nm. A small pore size can help to provide an effective barrier against contaminants, especially bacteria and viruses.
A preferred method for measurement of pore size involves use of solutions of polyethylene glycol molecules which differ from one another in respect of the molecular weights of the molecules. The solutions are pressurised against the membrane. Variations in the ability of the sheath material to allow the solution to pass through it depend on the molecular weight of the polyethylene glycol. A suitable measurement technique is disclosed in J Envir Engrg, Volume 128 Issue 5, pages 399 to 407 (May 2002).
The material of the sheath at the closed end in the vicinity of the electrodes can be different from the material of the sheath in other parts thereof. At least a portion of the wall of the sheath can be formed from an impermeable material. While it can be preferred for the walls of the sheath to be formed from one material, different materials can be used in different portions of the sheath.
The end of the probe on which the electrodes are provided is located within the sheath cavity prior to the sheath being placed in contact with a tissue sample. Preferably, at least a portion of the sheath is composed of a non-electrically conductive material having a porous structure which when contacted with a tissue sample allows the sheath to be impregnated with an aqueous solution which permits ionic conduction between the electrodes on the probe and the tissue sample. Alternatively, at least a portion of the sheath is composed of an electrically conductive material which has a greater resistivity than the tissue sample and provides a conductive path through the sheath between the electrodes and the tissue sample.
The sheath has the advantage that it can be easily fitted over the probe without requiring the sheath to be aligned with the electrical contacts present on the probe so as to form an electrical connection between the probe and the sheath. Furthermore, the sheath of the present invention has the advantage that the sheath makes electrical contact with a greater area of tissue than the prior art sheaths which have a plurality of electrodes spaced over the surface of the sheath. The electrical impedance of the tissue sample can therefore be measured over the entire area of tissue which is in contact with the sheath. The apparatus of the present invention therefore has improved sensitivity and specificity compared with constructions known previously, for example from WO-98/41151.
The dimensions of the sheath of the present invention depend on the dimensions of the probe which is to be covered. The sheath of the present invention preferably has a diameter of at least about 3 mm, more preferably at least about 5 mm, for example 6 mm. Preferably the diameter of the sheath is less than about 15 mm, more preferably less than about 10 mm, for example 8 mm. Preferably the sheath has a length of at least about 100 mm, more preferably at least about 125 mm, for example 150 mm. The length of the sheath is preferably less than about 250 mm, more preferably less than about 200 mm, for example 175 mm.
The sheath should preferably be a close fit on the probe. It can be preferred for the sheath to be a tight fit on the probe in the vicinity of the electrodes so that the electrodes are wetted by the solution which impregnates the sheath which is composed of a non-electrically conductive porous material so as to provide a conductive path between the electrodes and the tissue sample. Alternatively, it is preferred for the sheath to be a tight fit on the probe in the vicinity of the electrodes so that the electrodes are contacted with the electrically conductive sheath. It can also be preferred for the sheath to be a close fit on the probe at the open end of the sheath, so as to minimise ingress of material (especially contaminants) on to the surface of the probe within the sheath.
The probe can comprise a handle and a shaft. The handle of the probe is attached to the proximal end of the shaft. The shaft will often have a generally constant cross-section. The cross-section of the shaft (which might vary along its length) will generally be less than the cross-section of the handle. The cross-section of the handle might vary along its length, for example to facilitate secure handling by a user. In particular, the handle can be shaped so that it fits comfortably into a user's hand.
The electrodes will generally be arranged at or close to the end of the shaft. They can be provided on an end face of the probe so that they are directed at least partially away from the handle region of the probe. The electrodes can be provided on a side wall of the probe. The location of the electrodes will be selected according to the configuration of the tissue sample which is being examined.
Preferably, the sheath is used to cover at least the end of the probe where the electrodes are located. The sheath should preferably cover all of the surfaces of the probe which will be in contact with a patient's tissue sample during the examination procedure, at least those surfaces of the patient's tissue on which there are body fluids. Accordingly, the sheath preferably covers the probe tip and at least a portion of the probe shaft, especially the probe tip and the entire length of the probe shaft.
The sheath should be secured in place on the probe so that it does not become loose or otherwise dislodged during the examination of the patient's tissue. The material from which the sheath is formed can have elastic properties which can be relied on to help to secure the sheath on to the probe. A band of an elastic material can be applied over the sheath to secure it to the probe. A clip or other mechanical fastener can be used. The probe can be configured to assist in securing the sheath to the probe. For example, a groove can be provided in the probe for the sheath to deform into, either due to the elastic properties of the material of the sheath, or due to an additional fastener.
A sheath which has been used will preferably be disposed of after use, and then replaced with a new sheath. The present invention has the advantage that the same probe can be used repeatedly without the need to sterilise the probe between patients. The sheath of the present invention is therefore more cost effective than known screening probes or probe sheaths which require sterilisation of the probe or probe sheath or the replacement of the probe.
Preferably, the probe is capable of passing a current of at least about 1 μA peak-to-peak, preferably at least about 10 μA peak-to-peak, for example at least about 20 μA peak-to-peak. Preferably, the probes pass a current of less than about 50 μA peak-to-peak, for example 40 μA peak-to-peak.
In a preferred embodiment, the sheath of the present invention is capable of conducting a current of at least about 10 μA peak-to-peak, preferably at least about 20 μA peak-to-peak, for example at least about 30 μA peak-to-peak. Preferably, the sheath passes a current of less than about 50 μA peak-to-peak, for example 40 μA peak-to-peak.
Preferably, the tubular body of the sheath is in direct contact with at least a portion of the electrically conductive probe. Preferably, the sheath is composed of a water permeable, electrically non-conductive material which provides a number of pores or channels through which aqueous ions are able to diffuse. The diffusion of the water and ions into and through the sheath enables the current from the probe to pass to the tissue sample. If the sheath of the present invention is composed of a non-electrically conductive porous material which allows a large proportion of aqueous ions to diffuse through the sheath, the sheath will have a high electrical conductivity.
If the electrical conductivity of the sheath of the present invention when placed in contact with a tissue sample is greater than the electrical conductivity of the tissue sample the current from the probe will pass through the sheath rather than through the tissue sample.
During use, at least a portion of the sheath is placed in contact with the tissue sample. Preferably, the sheath is composed of a water permeable, electrically non-conductive material which allows aqueous ions to diffuse into the tubular body of the sheath providing an electrical contact between the electrical contacts of the probe and the tissue sample. However, the diffusion of the aqueous ions into the sheath which is composed of a water permeable, electrically non-conductive material occurs over a period of time and therefore there is a settling period associated with the readings of the sheath of the present invention. The settling time is the time required for the measurements made by the apparatus of the present invention to settle so as to provide accurate measurements of the tissue sample. If the portion of the sheath which is in contact with the tissue sample is relatively thick then the diffusion of the ions through the water permeable, electrically non-conductive sheath will be relatively slow and therefore the settling period associated with the sheath will be relatively long. Alternatively, if the portion of the water permeable, electrically non-conductive sheath which is in contact with the tissue sample is relatively thin the settling time will be relatively short. If the probe is covered by a sheath which is relatively thin however the risk of the sheath breaking during use is increased.
The current from the probe must be able to penetrate the tissue sample to a sufficient depth so as to be able to accurately measure the electrical impedance of the tissue sample. The squamous epithelium of the cervix has a thickness of approximately 400 μm. It is therefore preferable that the current from the probe penetrates the epithelium to a depth greater than 400 μm.
Factors affecting the choice of the thickness of the material of the sheath include having a sheath which is sufficiently thick so that the sheath has the toughness to withstand the treatment to which it will be subjected when in use without being damaged to the extent that the probe is exposed to the patient's body fluids. However, it can also be preferred to minimise the thickness of the material of the sheath so that the thickness of the conductive path is minimised. This can help to minimise the time taken for measurements to stabilise.
Preferably, the mean maximum thickness of the portion of the sheath which is in contact with the tissue sample is less than about 100 μm, more preferably less than about 75 μm, for example about 50 μm. Preferably, the mean minimum thickness of the portion of the sheath which is in contact with the tissue sample is more than about 10 μm, more preferably more than about 25 μm, for example 40 μm.
The inner surfaces of the walls of the tubular body of the sheath need not be in contact with the probe. For example, the closed end of the sheath is not in direct contact with the tip of the probe. Preferably, a gap is provided between the distal end of the probe and the inner surface of the tubular body of the sheath. Preferably, a wetting agent is present within the gap between the probe and the inner surface of the tubular body of the sheath so as to enable an electrical contact to be made between the sheath and the probe. Suitable wetting agents include aqueous solutions, such as for example salt solutions.
The sheath of the present invention can be composed of any suitable material having the properties discussed above. Preferably, the material of the sheath should be physically stable under the conditions to which it is exposed during use, for example at physiological temperatures. Preferably, the water permeable, electrically non-conductive material which is used at least at the closed end of the sheath includes at least one of cellulose acetate, polyethersulphone, polyamide and cellulose. Preferably, the electrically conductive material which is used at least at the closed end of the sheath includes at least one carbon loaded biocompatible materials. Suitable materials for forming the sheath of the invention include the cellulose based polymer materials sold by Medicell International Limited under the trade mark Visking and sold by Membrana GmbH under the trade mark Cuprophan.
The natural cellulose based polymer material sold under the trade mark Visking has a molecular weight cut-off (MWCO) range from 12000 to 14000. This cellulose based polymer material is stable at a temperature of 60° C. but will distort at approximately 120° C.
The natural cellulose based membrane sold under the trade mark Cuprophan has a molecular weight cut-off of about 10000 Daltons. Cuprophan is known to have good mechanical strength. Furthermore, due to the high suppleness of the material the risk of perforation of Cuprophan is reduced. Cuprophan is an unmodified cellulosic dialysis membrane manufacture by Membrana GmbH covering all basic requirements of standard dialysis treatment.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 depicts the results of tests using a probe together with a natural cellulose based membrane to measure the impedance of a cucumber at various frequencies.
DETAILED DESCRIPTION OF THE INVENTION
The present invention can be used to measure the electrical impedance of a cell sample to detect the presence of abnormal cells. The present invention can also be used to detect other conditions of a patient. For example, the onset of labour is accompanied by changes in tissue impedance which can be identified by such measurements. It has also been found that there is a noticeable difference in the electrical impedance of cervical tissues of pregnant women and women who are not pregnant. The present invention can therefore be used to diagnose obstetrical or non-obstetrical related conditions.
Embodiments of the invention will now be described in the following examples:
EXAMPLE 1
Electrical Conductivity
Preliminary electrical measurements were carried out on a range of membrane materials including cellulose acetate, polyethersulphone (PES), polyamide (nylon) and cellulose. Samples of natural cellulose based membranes sold under the trade marks Visking and Cuprophan were then selected for further electrical measurements. The sample of natural cellulose based membrane sold under the trade mark Visking is in the form of tubing. The properties of the samples of natural cellulose based membranes sold under the trade marks Visking and Cuprophan are illustrated in table 1.
TABLE 1
Thickness
Width
Length
MWCO
Normal
Material
Type
(μm)
(mm)
(mm)
(Daltons)
use
Cuprophan ™
Flat
11.5
250
250
10,000
Dialysis
sheet
Visking ™
Tubing
75.8 ± 5.7
10 flat
600
12-14,000
Dialysis
The measurement of the thickness of the sample of the natural cellulose based membrane sold under the trade mark Visking is a mean of twelve measurement made using a micrometer. The other data has been supplied by the manufacturer.
The first set of electrical measurements were carried out directly on samples of natural based cellulose materials sold under the trade marks Visking and Cuprophan which were placed between metal clamps. The second set of electrical measurements were made using a tetrapolar probe placed firstly in saline solutions and secondly on cucumber. A sample of the natural cellulose based membrane sold under the trade mark Visking or Cuprophan was then placed between the probe and the saline solutions or cucumber.
Cucumber was used as a test material as cucumber is a convenient test object which has a cellular structure and therefore a characteristic electrical impedance spectrum.
a) Membrane Measurements
Edge-to-edge measurements were obtained from a rectangular piece of each sample which was clamped at opposite ends between an aluminium plate and a PTFE holder. Face-to-face measurements were obtained by sandwiching a rectangular piece of each sample between two brass plates.
The equivalent combination of resistance R and capacitance C presented by each sample were measured using a Wayne Kerr Precision Analyser type 6425 at frequencies between 2 kHz and 20 kHz.
The samples were first measured when dry. The samples were then washed in warm water for 6 minutes and the measurements were taken again. The samples were then submerged in 5% physiological saline for at least 1 minute before a further reading was taken.
The results from two sets of experiments are shown in tables 2 and 3.
TABLE 2
Width
Length
Thick
C(pF)
C(pF)
R(kΩ)
R(kΩ)
Material
Geometry
Condition
(mm)
(mm)
(μm)
2 kHz
20 kHz
2 kHz
20 kHz
Cuprophan
face-face
Dry
10.0
10.0
15.7
60
57
∞
∞
Cuprophan
face-face
Washed
10.0
10.0
25.3
97
13
0.91
0.62
Cuprophan
face-face
Saline
10.0
10.0
27.3
1397
153
.0.31
0.022
Cuprophan
edge-edge
Dry
30.0
30.0
15.7
1
1
∞
∞
Cuprophan
edge-edge
Washed
28.0
30.0
25.3
2
2
540
579
Cuprophan
edge-edge
Saline
28.0
30.0
33.3
6
2
141
159
Visking
face-face
Dry
8.8
10.0
77.3
31
26
∞
∞
Visking
face-face
Washed
8.8
10.0
120
50
12
3.0
1.0
Visking
face-face
Saline
8.8
10.0
119
937
88
0.031
0.023
Visking
edge-edge
Dry
19.3
30.0
77.3
2
6
∞
∞
Visking
edge-edge
Washed
19.7
30.0
120
3
2
438
341
Visking
edge-edge
Saline
19.7
30.0
119
19
2
29
29
TABLE 3
Thickness
Impedance
Impedance
Resistivity
Material
Geometry
Condition
(μm)
(Ω)
phase (deg)
(Ωm)
Permittivity
Cuprophan
face-face
Dry
15.7
∞
89.9
∞
1.1
Cuprophan
face-face
Washed
25.3
910
0.1
5796
27.7
Cuprophan
face-face
Saline
27.3
31
0
122
43.0
Cuprophan
edge-edge
Dry
15.7
∞
85.5
∞
—
Cuprophan
edge-edge
Washed
25.3
540k
0.8
12.7
—
Cuprophan
edge-edge
Saline
33.3
141k
0.6
4.4
—
Visking
face-face
Dry
77.3
∞
89.9
∞
3.0
Visking
face-face
Washed
120
3k
0.1
2200
7.7
Visking
face-face
Saline
119
31
0
22.9
14.3
Visking
edge-edge
Dry
77.3
∞
87.7
∞
—
Visking
edge-edge
Washed
120
438k
0.9
34.5
—
Visking
edge-edge
Saline
119
29k
0.4
2.3
—
Electrical measurements were made on membrane samples. The results shown in table 3 are the mean of measurements made on three samples. Resistivities greater than 1 MΩm and impedances greater than 1 MΩ are shown as ∞. Impedance measurements were made at a frequency of 2 kHz.
The dry samples are non-conductive. The ‘face to face’ capacitance of the sample should simply reflect the thickness and permittivity of the samples. The relative permittivity may be calculated from the thickness and area of the sample. The calculated relative permittivity of the sample of natural cellulose based membrane sold under the trade mark Visking is 6 whereas the calculated relative permittivity of the natural cellulose based membrane sold under the trade mark Cuprophan is 1.
The resistivities can be calculated knowing the distance between the electrodes and the cross-sectional area of the membrane. The resistivities of the two samples at 20 kHz following washing with water are 833 Ωm (face-to-face) and 26.9 Ωm (edge-to-edge) for the sample of natural cellulose based membrane sold under the trade mark Visking and 2450 Ωm (face-to-face) and (edge-to-edge) 14.6 Ωm for the sample of natural cellulose based membrane sold under the trade mark Cuprophan.
After immersion in 5% saline solution the resistivities of the two materials are 19.3 Ωm (face-to-face) and 2.27 Ωm (edge-to-edge) for the sample of natural cellulose based membrane sold under the trade mark Visking and 80.6 Ωm (face-to-face) and 4.0 Ωm (edge-to-edge) for the sample of natural cellulose based membrane sold under the trade mark Cuprophan.
b) Measurements Made on Cucumber
A tetrapolar probe having a diameter of 5.5 mm was used. An AC current of 20 μA peak-to-peak was applied between a pair of electrodes and the resulting potential measured between the remaining two electrodes. Measurements were made over the frequency range of from 63 Hz to 64.5 kHz.
The cucumber was freshly sliced with a thickness of 10 mm. The spectral measurements were made by placing the face of the probe approximately half way between the centre and the edge of the cucumber. The samples were then each placed between the probe and the cucumber. Twelve measurements were made on the cucumber using 10×10 mm samples of the natural cellulose based membrane sold under the trade marks Visking or Cuprophan. The measurements were taken after the measurements had settled. The results are shown in FIG. 1 .
The results using the sample of the natural cellulose based membrane sold under the trade mark Cuprophan are almost indistinguishable from the measurements of the electrical impedance made by the probe without any membrane present. The measurements of the electrical impedance made using the sample of the natural cellulose based membrane sold under the trade mark Visking are lower than the measurements made by the probe without a sheath at low frequencies. This difference may be because the sample of the natural cellulose based membrane sold under the trade mark Visking is relatively thick and therefore there will be a shunt current. The sensitivity of the sheathed probe to the cucumber tissue will therefore be reduced when compared to the measurements of the unsheathed probe as the probe is further from the cucumber.
c) Settling Times
Twelve measurements were made at different points on the cucumber using samples of natural cellulose based membranes sold under the trade mark Visking and Cuprophan. The time for the measurements of the electrical impedance to settle was observed. The means and standard deviations for these settling times are shown in table 4.
TABLE 4
Condition
Thickness (μm)
Settling time (s)
Unsheathed probe
0
8.0 ± 5.2
Cuprophan ™ sheath
18.3 ± 6.1
6.6 ± 2.4
Visking ™ sheath
75.8 ± 5.7
46.9 ± 5.2
It can be seen that the settling time was not increased by the presence of the sample of the natural cellulose based membrane sold under the trade mark Cuprophan. However, the settling time is about 8 seconds even when using an unsheathed probe. A much longer settling time (46.9 seconds) is observed for the probe having a sheath composed of a natural cellulose based membrane sold under the trade mark Visking. It was also noted that the settling times increased at lower frequencies.
After these tests had been performed, the probe having a sheath composed of a natural cellulose based membrane sold under the trade mark Visking was used to measure a further 12 points on the cucumber. The mean settling time for this set of measurements was observed to be 16.1±7.9 seconds. This is considerably less than the mean settling time for the first set of measurements.
d) Measurements on Saline Solutions
Measurements on saline solutions were made by clamping the probe above the solution and then lowering it until it just made contact with a saline solution. The samples of the natural cellulose based membranes sold under the trade marks Cuprophan and Visking were then each placed over the end of the probe before the probe contacts the fluid. The samples were held in place against the probe with a rubber O-ring. The measurements were performed at a frequency of 9.6 kHz.
The saline solutions had varying conductivities within the range which would be expected on cervical tissue. The results are illustrated in Tables 5 and 6.
TABLE 5
Expected
Measured
Measured
Measured
resistivity
resistivity (Ωm)-
resistivity (Ωm)-
resistivity (Ωm)-
(Ωm)
unsheathed probe
Cuprophan ™
Visking ™
80.6
64.1
53.5
23.1
41.8
39.3
22.2
22.1
20.8
23.3
17.8
13.4
10.0
9.7
11.0
8.1
5.2
4.9
5.2
8.0
2.6
2.6
2.7
4.6
TABLE 6
Expected
Measured
Measured
Measured
resistivity
resistivity (Ωm)-
resistivity (Ωm)-
resistivity (Ωm)-
(Ωm)
unsheathed probe
Cuprophan ™
Visking ™
80.6
64.0
51.6
21.9
41.8
38.8
26.5
22.5
20.8
23.5
17.2
13.3
10.0
9.8
10.3
8.2
5.2
5.0
5.2
8.0
2.6
2.6
2.7
4.4
Measurements were made using a probe placed in contact with a saline solution. The measured resistivities are presented as the mean across the 30 frequencies between 63 Hz and 48 Hz. All measurements made using a membrane are significantly different (p<0.05) from those made using the bare probe.
When the probe is sheathed in a sample of a natural cellulose based membrane sold under the trade mark Visking™ appears to produce measurements which are underestimates of the true resistivity of the saline solution at high resistivities (>10 Ωm). The underestimates may be caused by a shunting of current in the sample of the natural cellulose based membrane sold under the trade mark Visking. The sample of the natural cellulose based membrane sold under the trade mark Visking also produces overestimates of the true resistivity of the solution at low resistivities (<10 Ωm) which could be due to the thickness of the tubing.
The sample of natural cellulose based membrane sold under the trade mark Cuprophan also produces some underestimation of the true resistivity of the solution at high resistivities (greater than 20.8 Ωm).
EXAMPLE 2
Infection Control Measurements
The ability of the samples of natural cellulose based membranes sold under the trade marks Visking and Cuprophan to block the passage of polio vaccine was tested. The sample of natural cellulose based membrane sold under the trade mark Visking is sold in the form of tubing.
A portion of the sample of the natural cellulose based membrane sold under the trade mark Visking was placed within a chamber containing 10 ml of PBS (phosphate buffer solution). 2 ml of PBS were placed within the inner region of the sample of the natural cellulose based membrane sold under the trade mark Visking. 3 drops of a polio vaccine were added to the inner region of the sample of natural cellulose based membrane sold under the trade mark Visking and gently mixed with the PBS. The test sample was left overnight. Two aliquots of dialsyate were taken from the outer chamber and one aliquot was taken from the inner chamber for qualitative enterovirus PCR (polymerase chain reaction) testing.
The sample of natural cellulose based membrane sold under the trade mark Cuprophan was tested by mounting the sample between two chambers of a perspex unit. 50 ml sterile PBS was placed on either side of the sample. One dose of a polio vaccine was added to the right hand side chamber of the unit. The test sample was left overnight. Three aliquots of dialysate were taken from the left hand side unit and one aliquot was taken from the right hand side unit for quantitative enterovirus PCR testing.
The aliquots were sent to a reference laboratory for PCR testing. No enterovirus RNA was detected as having passed through either of the samples of the natural cellulose based membrane sold under the trade marks Visking tubing or the Cuprophan membrane. The concentration of enterovirus RNA detected on the infection side of the sample of the natural cellulose based membrane sold under the trade mark Visking was 900000 TCID 50 per ml. The concentration of enterovirus RNA detected on the infection side of the Cuprophan membrane was 100000 TCID 50 per ml. | Apparatus for measuring the electrical impedance of a tissue sample comprises a probe and a sheath comprising an elongated tubular body having one closed end and one open end providing an internal cavity. The sheath is composed of a material which when contacted with a tissue sample is capable of providing a conductive path through the sheath between the electrodes and the tissue sample. The resistivity of the material forming the sheath when contacted with the tissue sample is greater than the resistivity of the tissue sample. The probe is received within the internal cavity of the sheath. The sheath is impervious to bacteria and viruses. | 0 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The invention concerns a gasket rotating between coaxial parts of the type which includes a metal mounting armature formed of two rings with a generally L-shaped cross-section placed on the top and bottom respectively to form the seating for a catch rim lining which interlocks with one of the rings.
2. Description of the Prior Art
According to a known method of fabrication, one of the rings has an axial catch flange for the other ring formed after mounting of the seating. Such an assembly makes it possible to create a monobloc unit by forming the catch flange of one of the rings on the other during fabrication.
This production method for the ring with which the desired catch flange is formed makes is necessary to use an elaborated section whose configuration must allow for local deformation.
The gasket of the present invention makes it possible to eliminate this problem by integration of all functions at the level of the gasket itself.
SUMMARY OF THE INVENTION
Accordingly, one object of the present invention is to provide a watertight support rim which interlocks with the lining attached to one of the rings and which rests on the outside edge of the other ring so as to keep the two rings together by enclosing this lining.
The assembly of the present invention lends itself favorably to fabrication of a monobloc gasket whose constituent parts are assembled in such a way as to give it the ability to absorb alignment or concentricity faults in the two coaxial parts.
A further object of the present invention is to provide a gasket which can be used as a self-lubricating bearing between coaxial parts supporting very light loads which are thus supported elastically by the lining enclosed between the two rings.
BRIEF DESCRIPTION OF THE DRAWINGS
A more complete appreciation of the invention and many of the attendant advantages thereof will be readily obtained as the same becomes better understood by reference to the following detailed description when considered in connection with the accompanying drawing, wherein:
The FIGURE details a cross-section of the rotating gasket.
DESCRIPTION OF THE PREFERRED EMBODIMENT
The rotating gasket represented is shown as it will appear once it has been mounted between two coaxial parts formed, to use a non-restrictive example, by the inner ring 10 and the outer ring 11 of a bearing, when the latter has a stopping shoulder 12 at the bottom of a mounting bore 13.
The rotating gasket 1 is composed of a metal mounting armature formed by an inverted outer ring 2 with a generally L-shaped cross-section which fits into the mounting bore 13 and rests against the shoulder 12 to define a chamber therebetween. On the ring 2 is molded a lining 3 with two main watertight rims, with one rim or lip 4 being radial and the other rim or lip 5 being axial. Both rims are in contact with an inner ring 6 with a generally L-shaped cross-section placed top to bottom in relation to the outer ring 2.
The inner ring 6, of which one flange extends radially toward the outer ring 2, has at the tip of this flange a slanted edge or end portion 7 tilted toward the part of ring 2 which is set in the mounting bore 13. A third watertight support rim 8 of the lining 3 rests on the slanted edge 7. This watertight support rim or lip 8 exerts axial force on the inner rim 6, which makes it difficult to separate the various elements of the gasket. The gasket formed in this way is ready for mounting, i.e., mounting is done simultaneously for the coaxial parts 10 and 11.
Thus, all the functional parts of the gasket, such as the lining 3 with rims 4, 5, and 8, and the surfaces in contact with these rims, are integrated and are not subject to the risk of deterioration following shocks or of pollution at the time of mounting.
The special positioning of the three watertight rims 4, 5, and 8 facilitates lubrication of these rims. The chambers or sub-chambers 91 and 92 which are formed, respectively, between axial rim 5 and support rim 8, and between axial rim 5 and radial rim 4, are greased so as to perfect lubrication of the respective lines of contact 41, 51 and 81 of the aforementioned rims 4, 5, and 8 with the inner ring 6.
This lubrication limits wear on the rims and prolongs the life of the gasket. Therefore, the grease used in the chambers 91 and 92 can be independent of the grease used to lubricate the coaxial parts. Thus, the lubricant can be chosen which is best suited to resolving a lead problem. For example, chamber 92 can be filled with a type of grease which ensures lubrication of rims 4 and 5, depending on the materials present and the utilization temperatures. The chamber 91 can be filled with a special grease which is resistant to external agents such as water or mud. This is of special interest when the gasket is being used on an automobile wheel bearing whose life and dependability are to be improved.
Therefore, the gasket according to the invention can be used advantageously in all cases where a rotating mechanical device is to be protected from the external environment.
Obviously, numerous modifications and variations of the present invention are possible in light of the above teachings. It is therefore to be understood that within the scope of the appended claims, the invention may be practiced otherwise than as specifically described herein. | A gasket is disclosed having a lining (3) with watertight rims (4,5,8) in which lining is placed between two rings (2,6). A rim (8), which interlocks with the lining (3) attached to one of the rings (2 or 6), rests on the edge (7) of the other ring (6 or 2) so as to keep the two rings together while enclosing the lining. | 5 |
BACKGROUND OF THE INVENTION
This invention relates to an electric drive system for a vehicle.
Vehicle electric drive systems or AC electric traction drives have been proposed to overcome some of the deficiencies of mechanical transmission systems, such as a limited number of speeds, increased costs of engineering and manufacturing components, and limiting vehicle configuration options. Such an electric drive system, as shown in U.S. Pat. No. 5,568,023 issued Oct. 22, 1996 to Grayer et al., typically includes an engine-driven 3-phase electric motor/generator coupled to an inverter/rectifier, which, in turn, is coupled to a DC bus. The bus feeds an inverter/rectifier which supplies power to a traction motor/generator which drives an axle or a wheel. The inverter/rectifiers invert the DC current on the bus to 3-phase AC current at a frequency to drive the wheels at the speed directed by the operator. An external power source applied to the tractor through the drive wheels and tending to move the tractor at a speed faster than the requested speed will cause the motors to act as generators and the whole sequence of power conversion will be reversed, regenerating mechanical power back into the engine. This regeneration action causes the engine to absorb power from externally forced loads in a manner similar to that of current mechanical transmissions.
Typically, the speed of the traction motor/generators is controlled by controlling the frequency of the current driving the motor. When the speed control is engaged, the drive will engage with full force or torque authority. Operators of conventional tractors with mechanical transmissions can depress a clutch pedal to release or reduce the torque driving the vehicle. By slowly engaging or disengaging such a mechanical clutch, the operator can control the torque being applied by the engine to move the vehicle. Therefore, by modulating the engagement of the clutch, the operator controls movement of the vehicle by controlling the driving force or torque that the wheels can exert. It would be desirable to have a similar clutch type control capability in an electric drive system.
SUMMARY OF THE INVENTION
Accordingly, an object of this invention is to provide a vehicle electric drive system with a control which operates in a manner similar to a clutch control of a conventional mechanical drive vehicle.
These and other objects are achieved by the present invention, wherein a vehicle electric drive system includes an engine driven electric motor/generator, a first inverter/rectifier coupled to motor/generator, a bus coupled to the first inverter/rectifier, a second inverter/rectifier coupled to the bus, and a traction motor/generator coupled to an output of the second inverter/rectifier. Electronic controllers control operation of the inverter/rectifiers in response to an operator speed control member. In addition, an operator controlled foot pedal is coupled to a transducer which generates a limit command signal representing the position of the foot pedal. An electronic control unit receives the limit command signal and limits current supplied by the second inverter/rectifier to the traction motor/generator to a limit current which is a function of the limit command signal and motor speed.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a simplified schematic diagram of a vehicle electric drive system according to the present invention;
FIG. 2 is a simplified schematic diagram of a operator control assembly for use with the present invention;
FIG. 3 is a logic flow diagram of an algorithm executed by the vehicle ECU of the control system of FIG. 1 .
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring to FIG. 1, a vehicle electric drive system 10 includes an internal combustion engine 12 controlled by electronic engine control unit (ECU) 13 . The engine 12 drives a 3-phase electric motor/generator 14 which supplies electrical power to and receives power from a bi-directional inverter/rectifier 16 , which is coupled to a high voltage DC bus 18 . The bus 18 feeds power to and receives power from bi-directional inverter/rectifiers 20 and 22 . Inverter/rectifier 20 is coupled to traction motor/generator 24 which drives and receives power from front wheels 26 . Inverter/rectifier 22 is coupled to traction motor/generator 28 which drives and receives power from rear wheels 30 via axle 32 via speed reducer 34 . Speed reducer 34 includes a high/low range box 35 which is controlled by a high/low range selector lever 37 . Each inverter/rectifier 16 , 20 and 22 is controlled by a corresponding micro-controller 17 , 21 and 23 , respectively. There are no batteries involved in the drive train as are normally used on drives for automobiles and buses.
The motors 24 and 28 are preferably DC brushless permanent magnet motors. Preferably, the rear motor 28 drives the rear axle through a two speed mechanically shifted gear box. Two speed gearing results in efficient motor operation because high gear provides the required speed to the axle for transport speeds, while the low gear provides the required torque to the axle for heavy pulling at low speeds.
An electronic vehicle control unit VCU 40 communicates with an operator control assembly 36 , the ECU 13 , various sensors (not shown), and the micro-controllers 21 and 23 . As best seen in FIG. 2, control assembly 36 includes a speed control lever 62 (or pedal or the equivalent) movable in a guide slot 64 with a forward branch 66 , a reverse branch 68 , a park branch 70 , a neutral position 72 and a hold zero speed position 74 . Control assembly 36 also includes conventional transducers 76 which are operatively coupled to the lever 62 and which generate lever position signals which are communicated to the VCU 40 . Control assembly may be similar to the shift quadrant which is used on production John Deere 7000 Series tractors. Control assembly 36 also preferably includes a torque hold switch 78 which is operatively coupled to the lever 62 and which generates a torque hold signal when lever 62 is in a neutral or park position.
Referring again to FIG. 1, rotor position sensors 44 , 46 and 48 are coupled to each of the motor/generators 14 , 24 and 28 and supply a rotation position signal to the corresponding micro-controllers 21 and 23 , 42 , which derive a speed signal therefrom. The inverter/rectifiers 20 , 22 invert and convert the DC bus current to a 3-phase AC current at a frequency to drive the wheels at a speed commanded by the operator via the speed control lever 62 . The rotor position sensors 46 , 48 , and the micro-controllers 21 , 23 form a closed speed control loop for each of the electric drive motors 24 and 28 , in which the microcontrollers 21 , 23 calculate a speed error from the difference between the commanded speed from lever 62 and the actual speed derived from sensors 46 , 48 , and a current is applied to the motors as a function of the speed error.
According to the present invention, an additional operator control device, preferably a foot operated pedal 50 , is coupled to a transducer 52 , such as a potentiometer, which generates a transducer signal (or limit command signal) representing the position of the pedal 50 . A spring 54 biases the pedal 50 to its raised position. A three position front wheel drive FWD switch 56 , and left and right brake switches 58 and 60 are also coupled to the VCU 40 . The brake switches are preferably operatively coupled to left and right brake pedals (not shown). The VCU 40 receives signals from the switches 56 , 58 and 60 , the speed control lever 62 and the clutch pedal transducer 52 . The VCU 40 also receives signals from a range box sensor switch 61 which provides VCU 40 with a signal representing the status of the high/low range box 35 . The VCU 40 executes an algorithm represented in simplified form by FIG. 2, and generates a torque limit signal which has a value which can vary from 0 to 100%. The inverter/rectifiers 20 , 22 and their associated microcontrollers 21 , 23 cooperate in response to the torque limit signal to limit the current supplied to the traction motor/generators 24 , 28 to limit the torque thereof accordingly.
Referring now to FIG. 2, the algorithm begins at step 100 when called from a main algorithm loop (not shown) which generates a vehicle speed command value which is applied to the micro-controllers 21 , 23 . Step 102 scans the various sensors and operator inputs and converts analog signals to digital signals. Step 104 converts the values from step 102 to engineering units. Step 106 scales and adds an offset to the signal from transducer 52 to form a clutch command signal so that the range of the clutch command signal corresponds to an upper portion of the movement range of the pedal 50 . Preferably, 100% clutch command signal will correspond to a position of pedal 50 slightly below its fully raised position, and a zero clutch command signal will correspond to when pedal 50 is depressed about 75%. Step 108 calculates a vehicle speed command signal (Veh_spd_cmd) based on a vehicle mode and the position of the speed control lever 62 .
Step 110 checks the consistency of the inputs commands and performs a safety check. If there is a failure, step 110 directs the algorithm to step 112 which sets a vehicle speed command value to zero and sets a torque limit value to zero, else to step 114 .
Step 114 limits a rate of change of the vehicle speed command value.
Step 116 calculates a rear motor speed required to achieve the desired speed, based on the vehicle speed command value, Veh_spd_cmd, and upon a rear gear ratio, as per the following C language computer statements:
RRGrat=Hi_Gear Ratio;
if(Lo_Rng)
RRGrat=Lo_Gear_Ratio;
Rmot_Spd_Cmd=RRGrat * veh_spd_cmd;
Veh_spd_cmd is the vehicle speed command computed from operator inputs, limited by actual vehicle speed. It is a function of an effective rear gearbox/tire ratio value, RRGrat determined from a range box sensor 61 . Lo_Rng is True when selector 37 is in its low speed range position. Hi_Gear_Ratio is the ratio of rear wheel speed to vehicle speed in the high speed range of the range box 35 . It includes the effect of rear tire rolling radius as well as the actual gear reduction. Lo_Gear_Ratio is the ratio of rear wheel speed to vehicle speed in the low speed range. Finally, the rear motor speed command, Rmot_Spd_Cmd, is calculated as a function of gear ratio, RRGrat, times veh_spd_cmd.
Step 118 calculates a rear motor torque limit value as a function of the position of the clutch command signal and of the speed control lever 62 , as per the following C language computer statements:
Rmot_Torq_Lim=Torq_Lim;
if ((Trq_Hld==FALSE))
Rmot_Torq_Lim=0.0;
The Rear Axle Torque Level is set equal to Torq_Lim, which is the desired percentage of available torque to be used for speed control based on the position of the operator's clutch pedal. The resultant Rmot_Torq_Lim is passed to the rear motor controller and it is the maximum percentage of available torque that the controller can apply in its attempt to maintain the commanded rear motor speed. If the load torque is below this level, the commanded motor(wheel)speed is maintained. If the load torque is above this level, the motor (wheel) speed slows down.
The Torq_Hld==FALSE statement checks for the Neutral position 72 of speed control lever 62 . Trq_Hld is always True if the operator's lever 62 is not at the zero speed position 74 . When the lever 62 is in the zero speed position, the operator can engage or disengage the Trq_Hld switch 78 to make Trq_Hld True in which case the motor controller 17 applies torque (up to the Torq_Lim) to maintain the commanded speed (zero), or False, in which case the operator is commanding free wheeling (neutral) or zero motor torque, regardless of the position of clutch pedal 50 .
Step 120 calculates a front motor speed command value, Fmot_Spd_Cmd, required to achieve the desired speed, based on the vehicle speed command value and upon a front gear ratio, as per the following C language computer statements:
Fmot_Spd_Cmd=veh_spd_cmd * FRGrat * Bst; where FRGrat is a ratio between front and rear wheel speeds (it includes the effect of rear tire rolling radius as well as the actual gear reduction. Bst is an effective boost ratio of the front wheel to rear wheel speed to maintain adequate load sharing. Thus, the front motor speed command is the product of the vehicle speed command, the effective gear ratio, and the boost factor.
Simultaneous application of both brake pedals modifies this speed command as described below in connection with step 122 .
Step 122 calculates a front motor torque limit value as a function of the position of the pedal 50 and of the speed control lever 62 , as per the following C language computer statements:
Fmot_Torq_Lim=Torq_Lim; (1)
if ((Trq_Hld==FALSE)) (2)
Fmot_Torq_Lim=0.0; (3)
if (MFWD_On==FALSE) (4)
Fmot_Torq_Lim=0.0; (5)
if ((MFWD_On)&&(MFWD_Auto)) (6)
{ (7)
if ((veh_spd_cmd−Auto_maxf)>0.) (8)
Fmot_Torq_Lim=0.0; (9)
if ((veh_spd_cmd+Auto_maxr)<0.) (10)
Fmot_Torq_Lim=0.0; (11)
} (12)
if (Fmot_Spd_Cmd>3000.) (13)
{ (14)
if ((Fmot_Torq_Lim<10.)&&(Torq_Lim>10.)) (15)
Fmot_Torq_Lim=10.; (16)
} (17)
if((Rt_Brk)&&(Lt_Brk)) (18)
{ (19)
Fmot_Torq_Lim=Brk_Torq; (20)
Fmot_Spd_Cmd=0.0; } (21)
In statement (1) a front motor torque limit is set based on the position of clutch pedal 50 where Torq_Lim is the desired percentage of available torque to be used for speed control based on the position of the clutch pedal 50 . The resultant Fmot Torq_Lim is passed to the front motor controller 21 and it is the maximum percentage of available torque that the controller can apply in its attempt to maintain the commanded front motor speed. If the load torque is below this level, the commanded motor (wheel) speed is maintained. If the load torque is above this level, the motor (wheel) speed slows down.
In statements 2 and 3 , the Trq_Hld value represents the status of switch 78 , and is always True if the operator's lever 62 is not at the zero speed position 74 . When the control lever 62 is in the zero speed position 74 , the operator can engage or disengage the Trq_Hld switch 78 to make Trq_Hld True in which case the motor controller applies torque (up to the Torq_Lim) to maintain the commanded speed (zero), or False, in which case the operator is commanding free wheeling (neutral) or zero motor torque, regardless of the position of clutch pedal 50 .
With respect to statements 4 and 5 , the 3 position switch 56 controls the engagement of the front wheel drive. The 3 positions of switch 56 set MFWD_On to True or False or to a third automatic mode. In the automatic mode, the front wheel drive is engaged (Fmot_Torq_Lim=Torq_Lim) below a speed of Auto_maxf (if moving forward) and is disengaged (Fmot_Torq_Lim=0) above that speed. In reverse and automatic mode, the front wheel drive is engaged (Fmot_Torq_Lim=Torq_Lim) below a speed of -Auto_maxr and is disengaged (Fmot_Torq_Lim=0) above that speed.
Statements 6 - 12 implement the MFWD_Auto feature.
In statements 13 - 17 , operate to cause the front motor controller 21 to maintain the torque of the front motor 24 at a minimum of 10% of maximum whenever the front motor speed command exceeds 3000 rpm, unless the a lower torque is commanded by the clutch pedal 50 .
Statements 18 - 21 provide a brake pedal override function. To provide front wheel braking torque when both brakes 58 , 60 are applied (Rt_Brk=True and Lt_Brk=True) statements 18 - 21 override all other speed and torque commands to the front wheel motor. Whenever both brakes are applied, a retarding torque up to the magnitude of Brk_Torq will be applied to slow the vehicle (regardless of vehicle direction).
Step 124 modifies the front motor torque limit value to zero if the FWD switch 56 is in its OFF, or if the FWD switch 56 is in its AUTO position and the front motor speed exceeds a preset limit speed.
Step 126 sets front motor speed to zero and sets the front motor torque limit value to a preset percentage of maximum available torque at current motor speed if the left and right brake switches 58 and 60 are both on.
Step 128 causes an exit from this subroutine.
Thus, the fully raised position of the pedal 50 represents a 100% current limit, that is 100% of the torque that the motor 24 or 28 is able to exert at its present operating speed. Depressing the pedal 50 rotates the potentiometer 52 and changes the clutch command signal supplied to the VCU 40 . The operator inputs a vehicle speed command through the speed control lever 62 , which the VCU, by steps 116 and 120 , converts to rear and front motor speed commands for the rear electric drive motor 28 and for the front electric drive motor 24 . Each of the electric drive motors 24 and 28 is in a closed speed control loop formed by the rotor position sensors 46 , 48 , and the micro-controllers 21 , 23 , in which the micro-controllers 21 , 23 generate a motor torque command value which is a function of a speed error, which is the difference between the commanded speed calculated from lever 62 in steps 116 and 120 and the actual speed derived from sensors 46 , 48 . The torque generated by each motor 24 , 28 is a function of the motor current. Preferably, the current is also electronically limited by the micro-controllers 21 and 23 in order to protect the motor and the controller. In addition, according to the present invention, the motor current and torque is further limited or varied as a function of the position of pedal 50 .
As the pedal 50 is depressed, the VCU 40 responds to the changing clutch command signal from potentiometer 52 by causing the microcontrollers 21 , 23 to reduce the current supplied to motors 24 , 28 and to thereby limit the torque of the motors until the torque reaches zero at a nearly fully depressed position of pedal 50 . From the operator's viewpoint, this system operates and reacts like a mechanical slipping clutch, however, there are no slipping surfaces to wear out, and control is easier to achieve. The system can operate indefinitely at low torque levels without damaging any components. The system allows an operator to move a vehicle slowly and with little force, such as when maneuvering close to buildings or hitching up to implements. This system permits an operator to engage the drive slowly and smoothly, and to precisely control the force exerted. It is possible for the drive axle to be exerting full torque at low or zero speed with the engine essentially at idle. With the clutch/inching pedal, the operator has full control of axle torque, so that the desired level of drive line torque can be maintained, even though one of the operator's cues to drive line torque level, engine noise, is less noticeable. This makes it easier to control the vehicle when hitching up to a mounted implement, for example,
With this system, engine power is transmitted to traction drives independent of engine speed, with a mechanically simple design and with an infinitely variable speed ratio.
While the present invention has been described in conjunction with a specific embodiment, it is understood that many alternatives, modifications and variations will be apparent to those skilled in the art in light of the foregoing description. Accordingly, this invention is intended to embrace all such alternatives, modifications and variations which fall within the spirit and scope of the appended claims. | A vehicle electric drive system includes an internal combustion engine, an electric motor/generator driven by the engine, a first inverter/rectifier coupled to motor/generator, a bus coupled to the first inverter/rectifier, a second inverter/rectifier coupled to the bus, and a traction motor/generator coupled to an output of the second inverter/rectifier, an operator speed control member, and a controller coupled to the second inverter/rectifier for controlling a current output of the second inverter/rectifier as a function of a position of the speed control member. Also included is an operator controlled foot pedal and a transducer coupled to the foot pedal and generating a signal representing foot pedal position which is supplied to the controller. The controller limits current supplied by the second inverter/rectifier to the traction motor/generator to a limit current as a function of the transducer signal. The controller, foot pedal and transducer cooperate to vary the limit current in response to movement of the foot pedal. A spring biases the foot pedal to an upper limit position. The controller causes the second inverter/rectifier to supply to the traction motor/generator a maximum amount of current, (such maximum current being a function of the foot pedal position), but not more than that required to achieve the speed commanded by the speed control. | 1 |
BACKGROUND OF THE INVENTION
[0001] The present invention relates to the security devices applicable notably to the transportation of precious or confidential documents, objects and funds or the monitoring of objects of value.
DESCRIPTION OF THE PRIOR ART
[0002] Amongst the security devices for transporting funds, protected cases are known, having means of neutralising documents or bank notes which they contain, by dispersing ink notably making the notes unusable.
[0003] The aforementioned neutralisation means include, for example, a pyrotechnic triggering system in the event of an attempt at forcible entry, the triggering system being parameterisable.
[0004] However, a protected case has the drawback of containing a limited number of notes in comparison with the large volume of ink which it must contain in order to ensure neutralisation of these notes.
[0005] Moreover, the use of protected cases often requires providing transportation vehicles, whilst providing in a vehicle compartments for receiving cases and providing these compartments with means of detecting the removal of each case out of its compartment.
[0006] Such arrangements are complex and expensive.
SUMMARY OF THE INVENTION
[0007] The invention aims to mitigate the drawbacks of the existing art by creating a control/command device ensuring control of the neutralisation and/or destruction of bank notes or documents whilst they are being transported notably in armored vehicles using radio frequency technologies.
[0008] The invention also aims to create such a control/command device for ensuring the monitoring of confidential documents or objects on their storage place.
[0009] According to the present invention, there is provided a control/command device for monitoring, neutralisation and/or destruction of valuables, documents and/or objects, wherein the control/command device includes at least one target device intended to be placed in the immediate vicinity of valuables, at least one document or an object to be monitored, neutralised and/or destroyed, at least one radio transmitter of signals containing information relating on the one hand to the target device and on the other hand to the valuables, document or object in the vicinity of which it is placed, the target device comprising an antenna for receiving signals coming from said transmitter, means connected to the said antenna for recognising in the signals of said transmitter the information concerning at least the target device placed in the vicinity of the valuables, document and/or object, means of detecting any abnormality in said signals, and controlling intervention means to indicate any incident in the monitoring of the object or proceeding with the neutralisation and/or destruction of the valuables or said at least one document.
[0010] The transmitter may have a range defining a predetermined security perimeter and the abnormality detection means may be means of detecting the exit of the target device out of the security perimeter of the transmitter through absence of reception of the signal from the transmitter.
[0011] The signals coming from the transmitter received by the target device may have a predetermined repetition rate and the abnormality detection means also can include means of detecting signals received outside the repetition rate.
[0012] The abnormality detection means can include a microprogrammed system connected to the antenna by a radio frequency coupler. It can also have associated with the antenna, a device for storing an electronic label identifying the target device and the valuables, document or object in the vicinity of which it is placed.
[0013] The abnormality detection means may have in the premises of at least one fund management or transportation company, an apparatus for monitoring bags of valuables to be transported, with which there are associated target devices, the control apparatus comprising a transceiver of radio frequency signals activating the target devices in a predetermined security perimeter, defined by the transmitter of the transceiver of the monitoring apparatus and the target devices each having means of detecting the absence of activation signals because the target devices have left the security perimeter of the control and command apparatus of the means of intervention by neutralisation and/or destruction of the valuables contained in the bags.
[0014] The abnormality detection means may have means associated with the transceiver for transmitting to the electronic label storage device of each target device data identifying the target device and the valuables contained in the bag with which the target bag is associated; it may also be connected to a central compatibility system or to an integrated company management system for receiving from the said system information relating to the identification target devices and to the valuables contained in the bags with which they are associated.
[0015] The abnormality detection means may also have at least one vehicle for transporting funds intended to receive the bags of valuables to be transported with which the target devices are associated, the vehicle comprising a transceiver for radio frequency signals activating the target devices in a predetermined security perimeter defined by the transceiver of the said vehicle, the means of detecting the absence of activation and control signals for the intervention means of each of the target devices reacting to the target devices leaving the security perimeter of the vehicle in order to control the intervention means for neutralising and/or destroying the valuables contained in the said bags.
[0016] The transceiver of said at least one vehicle may be in connection with a remote monitoring unit provided with a transceiver intended to receive alarm signals coming from the vehicle in the event of attack and to send, in response to the said alarm signals, to target devices situated in the vehicle, actuation signals outside the repetition rate of the activation signals of the target devices to enable the abnormality detection means to control the intervention means with a view to neutralising and/or destroying the valuables contained in the bags with which the target devices are associated.
[0017] The monitoring unit may be construction to send, to the target devices made active, information relating to the identity of the corresponding bags currently being loaded and possibly to the value of their content.
[0018] The monitoring unit may also have, in the premises of at least one company for managing or transporting bank notes, at least one apparatus for controlling the valuables delivered to the company by a transportation vehicle with which target devices are associated, the control apparatus comprising a transceiver of radio frequency signals activating the target devices in a predetermined security perimeter defined by the transmitter of the transceiver, the means of detecting the absence of activation signals contained in each target device when a target device leaves the security perimeter controlling the intervention means with a view to neutralising and/or destroying the valuables contained in the bag with which the said target device is associated.
[0019] The control apparatus may be a fixed or portable apparatus.
[0020] The said control apparatus may be formed by a gateway.
[0021] The transceiver of the control apparatus may be associated with means of activating the target devices when the target devices are inside protected premises of a company.
BRIEF DESCRIPTION OF THE DRAWINGS
[0022] For a better understanding of the invention and to show how the same may be carried into effect, reference will now be made, by way of example, to the accompanying drawings, in which:
[0023] [0023]FIG. 1 is a block diagram of the control/command device according to the invention;
[0024] [0024]FIG. 2 is a schematic view of the target device forming part of the control/command device according to the invention; and
[0025] [0025]FIG. 3 is a diagram showing the functioning of the control/command device according to the invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0026] The control/command device depicted in FIG. 1 is intended, for example, to provide the monitoring of the transportation of bank notes or other securities or valuables, whilst enabling them to be neutralised and/or destroyed at a distance using the transmission of information by radio frequency.
[0027] The radio frequency command and control device depicted in FIG. 1 has several bases transmitting radio frequency signals.
[0028] A first transmitting base includes a control apparatus in the form of a gateway 1 equipped with a radio frequency signal transceiver 2 and under which there are intended to be moved for example trolleys 3 transporting bags 4 of bank notes and with which there are associated target devices such as the device 5 , which will be described in more detail with reference to FIG. 2.
[0029] The control/command device also includes armored transportation vehicles such as the vehicle 6 . Each of the vehicles is equipped with a radio frequency signal transceiver 8 . In addition, at each delivery or removal point served by the armored vehicles 6 , there is provided a radio frequency signal transceiver 10 similar to the transmitters 2 and 8 and contained either in a gateway similar to the gateway 1 or in a portable control apparatus 11 .
[0030] The transceivers 2 , 8 and 10 are advantageously identical.
[0031] The gateway 1 is generally situated in the premises of a bank or a company transporting funds.
[0032] As depicted in FIG. 3, the transmitter of the transceiver 2 defines a safety perimeter P 1 which the target devices 5 and consequently the bank note bags 4 with which they are associated should not pass beyond.
[0033] Likewise the transceiver 8 of the armored vehicle 6 defines a security perimeter P 8 comprising the volume of the vehicle 6 itself and a zone for loading and unloading the latter in a security perimeter such as the perimeter P 1 defined by the gateway 1 .
[0034] The transceiver 10 of the portable control apparatus 11 , which can moreover also be incorporated in a gateway similar to the gateway 1 , is disposed in the premises of a company such as a commercial company or a bank which is to receive or dispatch bank notes or other valuables. Its transceiver defines a security perimeter P 10 . The transceiver 10 of the portable apparatus 11 and the transceiver 2 of the gateway 1 are also associated with means (not shown) of deactivating the target devices 5 .
[0035] The rôle of the gateway 1 and of the control apparatus 11 can also be provided by one and the same gateway or portable apparatus.
[0036] The control/command device also has a remote monitoring unit 14 provided with a transceiver intended to receive for example alarm signals coming from a vehicle such as the vehicle 6 in the event of attack and to send to the target devices 5 situated in the vehicle 6 suffering an attack actuation signal with a view to neutralising or destroying the bank notes transported by the vehicle and with which the target devices 5 are associated.
[0037] The bags containing the target devices 5 can be stored within a limit of 5 to 50 meters from any one of the radio frequency transmitters 2 , 8 and 10 defining the security perimeters or protected zones P 1 , P 8 and P 10 defined above and delimiting a functional security area which is determined according to the geographical structure of the places for loading and unloading the valuables. This distance, whose lower limit is 5 meters, helps to determine the radio frequency identification technology which can be used. Frequencies of 900 MHz, 2.45 MHz or any other frequency subsequently approved by the telecommunication regulatory authority may be adopted.
[0038] Finally, the control/command device according to the invention is connected to a central accounting installation 16 or to an integrated company management system, for example of the SAP R3 type.
[0039] [0039]FIG. 2 depicts schematically a target device like the target devices 5 in FIG. 1. This target device has an antenna 20 associated with a radio frequency electronic chip 22 or microcomponent which can be either of memory technology or of microprocessor technology, intended notably to store an electronic radio frequency identification label for the target 5 as well as values with which it is associated.
[0040] The antenna 20 is connected by means of the chip 2 and a radio frequency coupler 24 to a microprogrammed system 26 supplied by a battery or accumulator 28 and connected to a device 30 for intervening by spraying an ink for neutralising the bank notes or a chemical product for destroying these notes under the control of the microprogram system 26 . The operating frequencies of the frequency coupler 24 are in accordance with the current regulations.
[0041] Each target device 5 is a device which is before use in total standby mode, that is to say consuming, almost no energy. The change of this device into active mode is triggered when a transmitter such as the transceiver 2 contained in the gateway 1 is exposed to electromagnetic radiation.
[0042] As depicted in FIG. 3, the transmitter of the transceiver 2 of the gateway 1 defines a security perimeter P 1 .
[0043] It is assumed that the target device 5 is contained in a bag 4 of bank notes to be transported.
[0044] As depicted in FIG. 1, the bag 4 containing the target device 5 passes with a large number of other similar bags each provided with their target device, under the gateway 1 in front of the transceiver 2 which transmits an activation signal for all the target devices 5 passing through the gateway 1 .
[0045] Each of the target devices such as the device 5 then changes from standby mode to active mode and periodically receives an activation signal coming from the transmitter 2 .
[0046] When the bags with which the target devices 5 are associated pass under the gateway 1 , the amounts of the valuables transported in each of the bags are downloaded into each target device 5 . Each of these amounts, previously captured by a microcomputer, not shown, associated with the gateway 1 using for example the central accounting device 16 , ensures the accounting traceability of the valuables transported but has no security objective.
[0047] Simultaneously the vehicle 6 responsible for transporting the notes whose target devices 5 have been made active receives by radio, for example from the remote monitoring unit 14 , information relating to the identity of the bags currently being loaded and possibly the value of their content. The vehicle 6 is positioned by its driver so that its loading doors are situated inside the security perimeter P 1 defined by the transceiver 2 of the gateway 1 . The transceiver 8 of the armored vehicle 6 then defines the security perimeter P 8 around the vehicle, inside which it regularly transmits, every n seconds, messages for the target devices such as the device 5 , which will be situated in its security perimeter P 8 , that is to say which will be loaded into the vehicles, in order to keep these target devices in the active state.
[0048] The perimeters P 1 and P 8 define, at the time of the operations of transferring the bags of notes between the premises of the bank or of the transportation company and the armored vehicle 6 , an intersection zone 31 for transportation of the bags by handlers.
[0049] The current anticollision management technology of radio frequency applications makes it possible to read the identity and the value of several tens of bags per second when passing under a gateway and throughout the duration of transportation of the bags in the armored vehicle 6 . The target device 5 corresponding to each of the bags remains in active mode. The radio frequency coupler 24 of each target device 5 is interrogated continuously by the transceiver 8 of the armored vehicle 6 . The radio frequency identification system 8 of the armored vehicle 6 transmits a validation signal every 5 to 10 seconds, for example, making it possible to keep each target device 5 in active mode according to the dead man principle used in the protection of an isolated worker.
[0050] The transceiver 8 of the armored vehicle 6 reads all the radio frequency electronic labels recorded in the electronic chips 22 of the corresponding target devices 5 and records their presence as well as the content of the valuables if this has been entered by the client or the operator and/or directly by the accounting system in the radio frequency electronic label contained in the chip 22 .
[0051] This transceiver validates the quantitative data such as the number of bags and qualitative data such as the amount of the valuables contained in each bag.
[0052] As seen previously, the target device 5 associated with each bag 4 is kept in active mode throughout the duration of transfer of the bags which are kept in the security perimeter or field P 1 of the gateway 1 and/or in the security perimeter or field P 8 of the transceiver of the armored vehicle 6 and finally, when the vehicle 6 arrives at its destination, in the security perimeter P 10 of the transceiver 10 of the portable device.
[0053] At the end of the transportation of the bank notes by the armored vehicle 6 , the latter arrives at a delivery place, whose location is marked by the presence of the transceiver device 10 of the portable apparatus 10 held in the hand by an employee of the company delivering and defining the security perimeter P 10 whose intersection with the security P 8 of the transmitter 8 of the armored vehicle 6 delimits a zone 32 in which the transfer of the bags from the armored vehicle 6 to the premises receiving the bags of bank notes can be ensured with a maximum amount of security. The bags containing the target devices 5 are read by an employee of the transporter of funds by means of the portable terminal 11 containing the transmitter 10 . They can also be disposed on a support including a transceiver such as the transceiver 10 .
[0054] This terminal then provides a reading of the amount of the values contained in the bag by recognising the electromagnetic code contained in the electronic chip 22 of the target device 5 in order to verify the value of the content of each bag and to ensure accounting traceability of the valuables, and then deactivates the corresponding target device 5 , which returns to standby mode. If during various handlings of the bags containing the target devices 5 a bag were to leave one of the security perimeters P 1 , P 8 or P 10 , its antenna 20 , no longer receiving any periodic activation signal, causes the triggering, by the microprogrammed system 26 , of the device 30 for neutralising or destroying the bank notes contained in the corresponding bag.
[0055] In addition, the transporter of funds, which is represented either by the remote monitoring unit 14 of this company or by the driver of the armored transport vehicle 6 , has the possibility, in the event of an attempted attack, of controlling the triggering of the target devices 5 associated with the bags 4 of bank notes situated on board the armored vehicle 6 so that they provide the process of neutralising and/or destroying the valuables by an action in positive or negative mode from the armored vehicle.
[0056] The mode of triggering in positive mode is determined by the automatic nature of the occurrence of the triggering of the process if no derogation from the current action is generated during a parameterisable time T. The negative triggering mode is determined by an intentional action of an external process or an individual on the control/command system.
[0057] Advantageously, the triggering of the target devices 5 associated with the bags 4 transported in the armored vehicle 6 is provided by the remote monitoring unit 14 on reception, from a member of the team in the armored vehicle 6 , of information relating to an imminent attack or one which is currently being executed.
[0058] If, during the transfer, one of the bags containing a target device 5 in active mode is removed from the security perimeter P 1 defined by the transceiver 2 of the gateway 1 or from the security perimeter P 8 defined by the transceiver 8 of the armored vehicle 6 or from the security perimeter P 10 of the transceiver 10 of the reception center, the target device, no longer receiving any activation signal from one of the transmitters 2 , 8 , 10 , goes from active mode into triggered mode at the end of a predetermined time of n seconds, n being parameterisable. The triggered mode is managed automatically by a program contained in the microprogrammed system 26 of the target device 5 which, no longer receiving information coming from the radio frequency coupler 24 , the latter itself no longer receiving information from any radio frequency transmitter whatsoever, and this during a parameterisable time t, causes the triggering of the device 30 for neutralising or destroying the notes contained in the corresponding bag.
[0059] The control/command device which has just been described is applied to the monitoring and neutralisation or destruction of bank notes or other valuables during their loading, transportation and unloading.
[0060] It will easily be understood that this device can also be applied to the monitoring of rare documents or precious objects, in which case, instead of controlling their neutralisation by spraying ink or their destruction, the target devices trigger alarm devices or possibly the locking of exits from the premises containing the objects as soon as the objects and their associated target devices cross the security perimeter established by the control apparatus transmitting the validation signals to the target devices.
[0061] The control/command device uses commercially available technology. A list of the components forming part of the construction of the device is given below, along with a few examples of manufacturers of such components.
Component Manufacturer Transceiver 2, 8, 10 EM Marin Gemplus Motorola Oberthur Card Syst. Phillips - Mikron Schlumberger ST Microelectronics Target device 5 Antenna 20 and EM Marin microcomponent 22 Gemplus Motorola Oberthur Card Syst. Phillips - Mikron Schlumberger ST Microelectronics Radio frequency coupler EM Marin 24 Gemplus Motorola Oberthur Card Syst. Phillips - Mikron Schlumberger ST Microelectronics Microprogrammed system 26 Ampro Computers, Inc. Hitex GmbH Real Time Devices USA WinSystems, Inc. Remote monitoring unit 14 Brink's CCTG CET Protection One Delta-protection Euroguard | The device includes at least one target device intended to be placed in the immediate vicinity of valuables, at least one document or an object to be monitored, neutralized and/or destroyed, at least one radio transmitter of signals containing information relating on the one hand to the target device and on the other hand to the valuables, document or object in the vicinity of which it is placed, the target device comprising an antenna for receiving signals coming from the transmitter, means connected to the antenna in order to recognize in the signals from the said transmitter the information concerning on the one hand the target device and on the other hand the valuables, document and/or object in the vicinity of which it is placed, and means of detecting any abnormality in the said signals and intervention control means with a view to indicating any incident in the monitoring of the object or proceeding with the neutralization and/or destruction of the valuables or said at least one document. | 4 |
FIELD OF THE INVENTION
This invention relates to high-power, high-voltage modulators.
BACKGROUND
A broad range of applications require modulators and variable-voltage sources with high peak-power capabilities. Such applications include radar transmitters, X-ray machines, microwave-tube test sets, and semiconductor wafer manufacturing equipment. These machines and equipment employ such high-power amplifiers as cross-field amplifiers, traveling-wave tubes, magnetrons, klystron amplifiers (collectively referred to as “vacuum-electron devices”), and ion implanters. A number of high-voltage modulators are adapted to deliver pulsed power to these types of high-power amplifiers.
Conventional high-voltage modulators can be implemented using vacuum tubes, but the technology increasingly employs solid-state switches, which have higher peak-power capabilities and are more readily available. High-voltage modulators that employ solid-state switches provide excellent high-power, high-speed switching performance. There is always room for improvement, however, as competitive technology markets are ever watchful for cost-competitive systems that offer improved efficiency, reliability, speed performance, or a combination of these. For a detailed discussion of a conventional high-power modulator that employs solid-state switches, see U.S. Pat. No. 6,246,598,which is incorporated herein by reference.
BRIEF DESCRIPTION OF THE DRAWINGS
The subject matter disclosed is illustrated by way of example, and not by way of limitation, in the figures of the accompanying drawings and in which like reference numerals refer to similar elements and in which:
FIG. 1 depicts a high-voltage modulator 100 driving an anode of a klystron K 1 in accordance with one embodiment.
FIG. 2 details embodiments of driver 120 and switch SW 2 of FIG. 1 . Driver 120 is an “H” bridge with two identical halves driving respective inputs OFF and ON to the primary winding of transformer TX 2 .
DETAILED DESCRIPTION
FIG. 1 depicts a high-voltage modulator 100 driving an anode of a klystron K 1 in accordance with one embodiment. Modulator 100 drives klystron K 1 by alternately coupling the klystron anode to a high negative voltage via switch SW 1 and a low voltage via switch SW 2 . Each of switches SW 1 and SW 2 may include from one to N switch boards SB, coupled in series, with the number depending upon the magnitude of the switched voltage and the voltage rating of the switching elements on boards SB. A pair of driver boards DB 1 and DB 2 selectively turns switches SW 1 and SW 2 on and off responsive to optical trigger signals TRIG 1 and TRIG 2 . The driver boards are identical in this embodiment, as are the switches, so the following discussion is limited to driver board DB 1 and switch SW 1 .
Driver board DB 1 is powered by an AC source 105 via a first transformer TX 1 in this embodiment. The output terminals of transformer TX 1 connect to a conventional rectifier 110 , the positive and negative output terminals of which supply power to a controller block 115 and a driver 120 as a positive supply voltage VDR on a like-named supply node and zero volts on a ground node G 1 . Voltage VDR may vary, but is about fifteen volts in one embodiment. As with other designations used herein, VDR refers both to a signal and an associated node: whether a given reference is to a signal or a corresponding node will be clear from the context.
Driver 120 of driver board DB 1 provides output pulses to the primary windings of three transformers TX 2 via a pair of driver output terminals OFF and ON. The primary windings of transformers TX 2 are coupled in parallel so that the secondary windings issue simultaneous on and off pulses in response to pulses on output terminals OFF and ON. The pulses on the secondary windings of transformers TX 2 control switch boards SB to open and close switch SW 1 . In one embodiment, driver 120 issues a one microsecond pulse, from zero volts to VDR, on terminal ON to turn on switch SW 1 , and issues a subsequent similar pulse on terminal OFF to turn off switch SW 1 . The time between the pulses on node ON and node OFF determines the on and off times of switch SW 1 .
In one embodiment, switch SW 1 can be turned on for e.g. 100 us by asserting trigger signal TRIG 1 for 100 us: controller 115 issues a one-microsecond pulse on node PHB when signal TRIG 1 is asserted, and issues a subsequent one-microsecond pulse on node PHA when signal TRIG 1 is deasserted. Driver 120 responds to the pulses on nodes PHB and PHA by issuing corresponding pulses on respective driver output nodes ON and OFF to convey current through the primary winding of transformer TX 2 , and consequently through the secondary windings as well. The current through the secondary windings turns switch SW 1 on or off, depending upon the direction of current flow in the secondary windings.
The turns ratio of transformer TX 2 can vary, but is 1:1 in this example, with a single primary winding extending through the center of a toroid core. A single primary winding advantageously provides a high degree of voltage isolation between switch SW 1 and board DB 1 . The use of optical triggers and transformer TX 1 additionally isolates board DB 1 .
In some embodiments switch SW 1 may require one or more refresh pulses to remain on or off for a desired timing interval. In the embodiment of FIG. 2 , discussed below, the switch may require refresh-on pulses to remain on for extended periods, but does not require refresh-off pulses. Refresh pulses can be initiated by trigger signals. Alternatively, controller 115 can be configured to refresh periodically to maintain a desired switch state. Other embodiments will differ, as will be readily understood by those of skill in the art.
Modulator 100 may be adapted to switch very high voltages. In one embodiment, klystron K 1 employs a cathode voltage VCAT of about −43 KV and a collector voltage of about zero volts. A cutoff supply 125 increases the absolute value of the anode voltage ANODE of klystron K 1 to 2 KV above cathode voltage VCAT (to −45 KV) for application by switch SW 1 . This 2 KV increase ensures klystron K 1 turns off and stays off when switch SW 1 closes.
Switching high voltages generates high charging currents through stray capacitances CS 1 and CS 2 , which can cause considerable electrical noise to couple to driver board DB 1 . (Other stray capacitances, such as those associated with the other transformers TX 2 , are omitted for ease of illustration.) Capacitors C 1 and C 2 are coupled between respective inputs of transformer TX 2 and a second ground G 2 to convey this switching noise to the primary winding of transformer TX 1 via stray capacitance CS 3 through transformer TX 1 . Ground G 2 may be inductively isolated from ground G 1 to prevent the noise coupled from switch SW 1 via transformer TX 2 from interfering with the operation of controller 115 and driver 120 . In one embodiment ground G 2 is isolated from driver board DB 1 by tying the ground side of capacitors C 1 and C 2 to a ground lug via a low-inductance conductor.
FIG. 2 details driver 120 , one of transformers TX 2 , and switch boards SB (all FIG. 11 ) in accordance with one embodiment. In this example, driver 120 is an “H” bridge with two identical halves driving respective inputs OFF and ON to the primary winding of transformer TX 2 . Switch board SB includes a stack of e.g. twenty series-coupled switching elements SWE, each of which drops about 1/20 th of the voltage across the one switch board SB. There being three switch boards in the embodiment of FIG. 1 , each switching element SWE drops about 1/60 th of the 45KV modulated on node ANODE in that embodiment. Each switching element SWE is disposed between and selectively couples first and second high-current source nodes SN 1 and SN 2 , and the depicted series of switching elements work in concert to selectively couple nodes IN and OUT. The configuration of each switching element is identical in this embodiment, so only the lowermost instance of switching element SWE is described in detail. The number of switching elements connected in series may change based upon the magnitude of the switched voltage and the voltage rating of the switching transistors. In one embodiment, the switching elements SWE employ insulated-gate bipolar transistors (IGBTs), but other types of power-switching devices might also be used, as will be readily understood by those of skill in the art.
The following discussion describes how driver 120 responds to a one-microsecond pulse (zero to VDR to zero) on node PHB by issuing a negative-going pulse (VDR to zero to VDR) on terminal ON. The pulse on terminal ON causes current to flow through the primary winding of transformer TX 2 . The resulting currents through the secondary windings of transformer TX 2 turn on all the switching elements SWE in the stack, and consequently turn on switch SW 2 .
To begin, assume switch SW 2 is off (not conducting) and both input signals PHA and PHB are at ground potential. In that case, signals PHA and PHB pull the control terminals of transistors Q 1 and Q 3 away from VDR, turning transistors Q 1 and Q 3 on and Q 2 and Q 4 off. Both input terminals to transformer TX 2 are therefore pulled to supply voltage VDR and no current flows through the primary winding. The breakdown voltages of zener diodes D 14 and D 16 are each 8.2 volts in an embodiment in which VDR is fifteen volts. Capacitors C 4 and C 3 bypass respective zeners D 14 and D 16 to reduce the time delay associated with turning on and off transistors Q 1 and Q 3 .
To initiate an on pulse, and thus close switch SW 2 , signal PHB is pulled to voltage VDR and signal PHA is left at ground potential. Raising PHB turns transistor Q 3 off and Q 4 on, creating a current path through transistor Q 1 , the primary winding of transformer TX 2 , and transistor Q 4 . To terminate the on pulse, signal PHB is returned to ground, which turns transistor Q 3 on and Q 4 off, eliminating the current path through the primary winding of transformer TX 2 .
A zener D 17 and a capacitor C 6 couple node PHB to the control terminal of transistor Q 4 in the same manner diode D 16 and capacitor C 3 couple node PHB to the control terminal of transistor Q 3 . Diodes D 8 and D 9 and resistors R 47 and R 48 ensure transistors Q 3 and Q 4 turn off faster than they turn on to prevent transistors Q 3 and Q 4 from conducting simultaneously during switching. A second pair of diodes D 11 and D 19 provide source-to-gate over-voltage protection for transistors Q 3 and Q 4 . The H bridge of driver 120 is unusual in that high-side transistors Q 1 and Q 3 are both biased on while awaiting an input signal on nodes PHA or PHB. The H bridge can therefore generate on pulses by turning on just one transistor. The same is true for off pulses, as noted below. Leaving on just the high-side transistors (or just the low-side transistors) may improve noise immunity by providing low-impedance paths from nodes ON and OFF and supply terminals that evince relatively stable voltages. A more traditional H bridge configuration may be used in other embodiments.
The current pulse from node OFF to node ON causes transformer TX 2 to send a current pulse through each secondary winding. With reference to the lowermost winding and the associated switching element SWE, the secondary current develops a positive voltage of e.g. fifteen volts across a resistor R 50 , the terminals of which are coupled to the input nodes to switch SW 2 . This voltage is transmitted to the gate of a high-voltage IGBT Q 5 via a resistor R 55 and a zener diode D 50 , thereby turning IGBT Q 5 on. Diode D 50 holds the resulting charge on the gate of IGBT Q 5 to keep the IGBT on after the voltage across resistor R 50 dissipates. The remaining series-coupled switching elements SWE likewise turn on, effectively closing switch SW 2 .
The charge collected on the gate of IGBT Q 5 bleeds off via a resistor R 60 and the leakage through a transient voltage suppressor T 1 that provides gate-to-source over-voltage protection for IGBT Q 5 . Unless this charge is refreshed, switch SW 2 will eventually shut off in this embodiment. It may therefore be necessary to refresh the charge periodically if the on-time of switch SW 2 is to be relatively long. The IGBTs will typically be turned on and refreshed such that the applied gate voltage maintains them in saturation for as long as switch SW 2 is closed.
To initiate an off pulse to open switch SW 2 , signal PHA to driver 120 is pulled to voltage VDR. Raising PHA turns transistor Q 1 off and Q 2 on, creating a current path through transistor Q 3 , the primary winding of transformer TX 2 , and transistor Q 2 . Returning signal PHA to ground potential turns transistor Q 1 on and Q 2 off, eliminating the current path through the primary winding of transformer TX 2 . The operation of the half of driver 120 disposed between nodes PHA and OFF is identical to the other half in the instant case, like-identified elements being the same or similar, so a detailed discussion is omitted for brevity.
The “off” current from node ON to node OFF causes transformer TX 2 to send a current pulse through each secondary winding in the opposite direction of on pulses. With reference to the lowermost switching element SWE, the current through the secondary winding develops a negative voltage of e.g. negative fifteen volts across resistor R 50 , which charges the gate of IGBT Q 5 in the opposite polarity through resistor R 55 and zener D 50 . In an embodiment in which zener D 50 drops ten volts, the gate-to-emitter voltages on each IGBT Q 5 in the series is about negative five volts. This gate-to-emitter voltage shuts off the transistors, effectively opening switch SW 2 . The off-pulses on the secondary windings of transformer TX 2 should be long enough to complete the transition of the associated transistors Q 5 from on to off. Likewise, the on-pulses on the secondary windings of transformer TX 2 should be long enough to complete the off-to-on transition.
A feedback path extending between the collector (first current-handling terminal) and gate (control terminal) of IGBT Q 5 includes a series of transient voltage suppressors T 2 , a diode D 55 , and a damping resistor R 65 . By elevating the gate voltage on transistor Q 5 when the collector voltage exceeds a predetermined level, the feedback path clamps the collector-to-emitter voltage of IGBT Q 5 to a level below the manufacturer's absolute maximum voltage rating. By adding or subtracting from the number of transient voltage suppressors T 2 , the clamping voltage between the collector and emitter of IGBT Q 5 can be adjusted to accommodate devices with different collector-to-emitter voltage ratings.
When the voltage between the collector and gate of IGBT Q 5 increases above the predetermined level, transient voltage suppressors T 2 , diode D 55 , resistor R 65 , and zener D 50 conduct current to the gate of IGBT Q 5 to keep the IGBT out of the cutoff mode. Keeping the IGBT out of the cutoff mode lowers the dynamic impedance of the IGBT, and hence the collector-emitter voltage across the IGBT. This action protects the IGBT from over-voltage conditions that might occur due to power-supply transients and when attempting to turn switch SW 2 on or off, particularly in the presence of an inductive load. Should transistor Q 5 in one switching element turn on more slowly than the others, the resulting voltage developed between the collector and the gate of the slower one of transistors Q 5 causes the feedback path to conduct charge to the gate of that transistor, and thus reduces the off-to-on transition time of the transistor. Similarly, should one of the series of transistors Q 5 turn off more slowly than the others, the resulting voltage developed between the collector and the gate of the transistor causes the feedback path to conduct charge to its gate to prevent the transistor from turning off too quickly. The feedback paths thus equalize the turn-off times and the turn-on times of switching elements SWE so that no switch or subset of switches suffers a potentially damaging over-voltage condition. This feature advantageously simplifies the task of matching the turn-on and turn-off times of the series devices.
Diode D 55 ensures that a majority of the on-current from the secondary winding of transformer TX 2 is delivered to the gate/emitter junction of the IGBT, rather than to charge the capacitance associated with the protection path, and additionally prevents current from passing from gate to collector when transistor Q 5 is in saturation. Resistor R 65 lowers the clamping response of collector-to-gate feedback path to reduce ringing and oscillation. The above-referenced U.S. Pat. No. 6,246,598 (the '598 patent) describes a high-voltage modulator with a feedback scheme similar to that of FIG. 2 of the instant application. The feedback path of the '598 patent is coupled between the collector and gate of the associated transistor without the intervening diode D 50 , however. Diode D 50 isolates the gate of IGBT Q 5 from leakage current through the feedback path, as such leakage can interfere with the proper operation of the IGBT. Instead of developing a voltage across resistor R 60 , leakage current from the feedback path is dissipated through resistors R 55 and R 50 . The feedback path of the '598 patent also lacks resistor R 65 and the associated damping effect.
Each IGBT has an associated series of balancing resistors R 70 between its emitter and collector. Balancing resistors R 70 ensure that each IGBT has about the same collector-to-emitter voltage when switch SW 2 is off. In some embodiments, a capacitor can be added in parallel with resistor R 70 to further dampen voltage transients, as shown in the '598 patent. A diode D 60 connected in parallel with resistors R 70 is a fast-recovery voltage device that may be included to prevent transistor Q 5 from being reverse biased from emitter to collector. Such reverse conduction might occur, for example, if modulator 100 is used with an inductive load.
In the foregoing description and in the accompanying drawings, specific terminology and drawing symbols are set forth to provide a thorough understanding of the present invention. In some instances, the terminology and symbols may imply specific details that are not required to practice the invention. For example, signals described or depicted as having active-high or active-low logic levels may have opposite logic levels in alternative embodiments. As another example, circuits described or depicted as including IGBTs may alternatively be implemented using any other technology in which a signal-controlled current flow may be achieved.
While the present invention has been described in connection with specific embodiments, variations of these embodiments will be obvious to those of ordinary skill in the art. For example,
1. while the circuitry employed in the feedback path of the above-described switching elements are implemented using discrete components, the switching and feedback circuitry may be integrated in other embodiments; and 2. switching elements and switch boards can be combined in parallel for increased current-handling. Moreover, some components are shown directly connected to one another while others are shown connected via intermediate components. In each instance the method of interconnection, or “coupling,” establishes some desired electrical communication between two or more circuit nodes, or terminals. Such coupling may often be accomplished using a number of circuit configurations, as will be understood by those of skill in the art. Therefore, the spirit and scope of the appended claims should not be limited to the foregoing description. Only those claims specifically reciting “means for” or “step for” should be construed in the manner required under the sixth paragraph of 35 U.S.C. Section 112. | A high-power modulation system includes drive circuitry that receives input signals from the signal source via a series of transformers. The drive circuitry amplifies the input signals and provides the resulting amplified signals to the high-power switch. The switch includes a series of stacked switching elements, each with a control terminal, first and second current-handling terminals, and feedback path extending between the first current-handling terminal and the control terminal. The feedback paths work in concert to turn the switches on and off together to prevent excessive voltage from developing across one or a subset of the switching elements. The feedback path includes a resistor that dampens the bandwidth of the feedback path to reduce turn-off and turn-on ringing and oscillation. The damping resistor may be coupled in series with a diode that holds charge against the control terminal of the switching element. | 7 |
CROSS-REFERENCE TO RELATED APPLICATIONS
This application is related to co-pending U.S. Patent Application Ser. No. 14/014,633 entitled “ANTENNA ASSEMBLY AND ELECTRONIC DEVICE USING THE ANTENNA ASSEMBLY”. Such application has the same assignee as the present application. The above-identified applications are incorporated herein by reference.
BACKGROUND
1. Technical Field
The present disclosure relates to antenna assemblies, especially to an antenna assembly integral with metal housing and an electronic device using the antenna assembly.
2. Description of Related Art
Miniaturization of electronic devices applies as well to antennas as for the electronic devices. At the same time, electronic devices having metal housings are popular since the metal housings have high strength, high heat dissipation, tactile satisfaction, and attractive appearance. However, when the electronic devices having metal housings are miniaturized, the keep-out zones of the antennas may be reduced. As a result, the sending/receiving efficiency for signals of the antennas is adversely affected.
Therefore, there is room for improvement within the art.
BRIEF DESCRIPTION OF THE DRAWINGS
Many aspects of the disclosure can be better understood with reference to the following drawings. The components in the drawings are not necessarily drawn to scale, the emphasis instead being placed upon clearly illustrating the principles of the disclosure. Moreover, in the drawings, like reference numerals designate corresponding parts throughout the several views.
FIG. 1 is an isometric view of partial of an electronic device having an antenna assembly in accordance with an exemplary embodiment.
FIG. 2 is a return loss diagram for the antenna assembly of FIG. 1 .
DETAILED DESCRIPTION
FIG. 1 shows an antenna assembly 100 which is used in an electronic device 200 having a metal housing. The electronic device 200 may be a mobile phone, a tablet computer, or a radio communication device, for example.
The electronic device 200 includes a circuit board 220 . The circuit board 220 defines a feeding point 222 , through which the circuit board 220 feeds electrical signals to the antenna assembly 100 . The circuit board 220 also defines a grounding point (not shown).
The antenna assembly 100 includes a feeding terminal 10 , a radiator 30 , and a metal element 70 . The feeding terminal 10 electrically connects to the feeding point 222 . The radiator 30 connects to the feeding terminal 10 . The metal element 70 is spaced from the radiator 30 .
In the exemplary embodiment, the radiator 30 includes a first radiator 31 and a second radiator 33 . The first radiator 31 is substantially perpendicularly connected to the feeding terminal 10 . The second radiator 33 is substantially perpendicularly connected to the first radiator 33 , and on a same plane as the first radiator 31 . The length of the second radiator 33 is greater than the length of the first radiator 31 .
The metal element 70 is metal and part of the metal housing of the electronic device 200 . The metal element 70 includes a frame 71 , a first antenna unit 72 and a second antenna unit 74 , both of which extend from the frame 71 . The frame 71 is connected to the grounding point of the circuit board 220 by screws or metallic flexible sheet (not shown).
The first antenna unit 72 is substantially perpendicularly connected to the frame 71 . The first antenna unit 72 is on a first plane, the frame 71 is on a second plane, and the radiator 30 is on a third plane. The first plane, the second plane, and the third plane are vertical to each other. In the exemplary embodiment, the first antenna unit 72 is a sheet extending towards the radiator 30 , and spaced from the second radiator 33 . The second antenna unit 74 is also on the first plane. The second antenna unit 74 includes a first extending sheet 741 , a second extending sheet 743 , and a third extending sheet 745 . The first extending sheet 741 extends towards a direction as the same as the first antenna unit 72 . The first extending sheet 741 is parallel to and spaced from the first antenna unit 72 , and has a length greater than the length of the first antenna unit 72 . The second extending sheet 743 extends perpendicularly towards the radiator 30 , and substantially perpendicularly connects to the first extending sheet 741 and the third extending sheet 745 . The third extending sheet 745 extends towards the feeding terminal 10 , and is spaced from the second radiator 33 and the first antenna unit 72 . In the exemplary embodiment, the vertical distance between the third extending sheet 745 and the first extending sheet 741 is equal to the vertical distance between the first antenna unit 72 and the first extending sheet 741 . The first antenna unit 72 and the first extending sheet 741 cooperatively define a first slot. The third extending sheet 745 and the first extending sheet 741 cooperatively define a second slot.
When the feeding terminal 10 passes electrical signals from the electronic device 200 , the electricity flows through the first radiator 31 and the second radiator 33 to excite a first mode to receive or send a first signal, such as a WCDMA band2 signal. Since the first antenna unit 72 and the second antenna unit 74 both are parallel and adjacent to the second radiator 33 , the electricity of the second radiator 33 can flow to the first antenna unit 72 and the second antenna unit 74 . The electricity flowing to the first antenna unit 72 flows through the frame 71 and then to ground, allowing a second mode to be excited, to receive or send a second signal, such as a WCDMA band1 signal. The electricity flowing to the second antenna unit 74 flows through the third extending sheet 745 , the second extending sheet 743 , and the first extending sheet 741 , in that order, to the frame 71 and then to ground, allowing a third mode to be excited, to receive or send a third signal, such as GSM 850 signal and GSM 900 signal. FIG. 2 shows that the antenna assembly 100 has a low return loss at a first bandwidth between about 800 MHz to about 900 MHz, at a second bandwidth between about 1800 MHz to about 1900 MHz, and at a third bandwidth between about 1900 MHz to about 2100 MHz.
The exemplary antenna assembly 100 utilizes the metal element 70 of the electronic device 200 to form both a first antenna unit 72 and a second antenna unit 74 , which reduces the keep-out zone of the antenna assembly 100 without adversely affecting the efficiency of the antenna assembly 100 . As a result, the size of the antenna assembly 100 and the electronic device 200 are reduced.
It is believed that the exemplary embodiment and its advantages will be understood from the foregoing description, and it will be apparent that various changes may be made thereto without departing from the spirit and scope of the disclosure or sacrificing all of its advantages, the examples hereinbefore described merely being preferred or exemplary embodiment of the disclosure. | The metal housing of a miniaturized electronic device is shaped to function as a multiband antenna assembly. The antenna assembly includes a feeding terminal, a radiator connecting to the feeding terminal, and a metal element. The metal element is part of a housing of the electronic device. The metal element includes two antenna units, both of which are adjacent to and spaced from the radiator. An electronic device using the antenna assembly is also described. | 7 |
FIELD OF THE INVENTION
[0001] This invention relates generally to the field of digitally controlled printing devices, and in particular to continuous ink jet printheads which integrate multiple nozzles on a single substrate and in which print nonprint operation is effected by controlled deflection of the ink as it leaves the printhead nozzle.
BACKGROUND OF THE INVENTION
[0002] Many different types of digitally controlled printing systems have been invented, and many types are currently in production. These printing systems use a variety of actuation mechanisms, a variety of marking materials, and a variety of recording media. Examples of digital printing systems in current use include: laser electrophotographic printers; LED electrophotographic printers; dot matrix impact printers; thermal paper printers; film recorders; thermal wax printers; dye diffusion thermal transfer printers; and ink jet printers. However, at present, such electronic printing systems have not significantly replaced mechanical printing presses, even though this conventional method requires very expensive setup and is seldom commercially viable unless a few thousand copies of a particular page are to be printed. Thus, there is a need for improved digitally controlled printing systems, for example, being able to produce high quality color images at a high-speed and low cost, using standard paper.
[0003] Inkjet printing has become recognized as a prominent contender in the digitally controlled, electronic printing arena because, e.g., of its non-impact, low-noise characteristics, its use of plain paper and its avoidance of toner transfers and fixing. Ink jet printing mechanisms can be categorized as either continuous ink jet or drop on demand ink jet. Continuous ink jet printing dates back to at least 1929. See U.S. Pat. No. 1,941,001 to Hansell.
[0004] U.S. Pat. No. 3,373,437, which issued to Sweet et al. in 1967, discloses an array of continuous ink jet nozzles wherein ink drops to be printed are selectively charged and deflected towards the recording medium. This technique is known as binary deflection continuous ink jet, and is used by several manufacturers, including Elmjet and Scitex.
[0005] U.S. Pat. No. 3,416,153, which issued to Hertz et al. in 1966, discloses a method of achieving variable optical density of printed spots in continuous ink jet printing using the electrostatic dispersion of a charged drop stream to modulate the number of droplets which pass through a small aperture. This technique is used in ink jet printers manufactured by Iris.
[0006] U.S. Pat. No. 3,878,519, which issued to Eaton in 1974, discloses a method and apparatus for synchronizing droplet formation in a liquid stream using electrostatic deflection by a charging tunnel and deflection plates.
[0007] U.S. Pat. No. 4,346,387, which issued to Hertz in 1982 discloses a method and apparatus for controlling the electric charge on droplets formed by the breaking up of a pressurized liquid stream at a drop formation point located within the electric field having an electric potential gradient. Drop formation is effected at a point in the field corresponding to the desired predetermined charge to be placed on the droplets at the point of their formation. In addition to charging rings, deflection plates are used to deflect the drops.
[0008] Conventional continuous ink jet utilizes electrostatic charging rings that are placed close to the point where the drops are formed in a stream. In this manner individual drops may be charged. The charged drops may be deflected downstream by the presence of deflector plates that have a large potential difference between them. A gutter (sometimes referred to as a “catcher”) may be used to intercept the charged drops, while the uncharged drops are free to strike the recording medium. In the current invention, the electrostatic tunnels and charging plates are unnecessary.
SUMMARY OF THE INVENTION
[0009] It is an object of the present invention to provide a high-speed continuous ink jet apparatus and method whereby drop formation and deflection may occur at high repetition.
[0010] It is another object of the present invention to provide a method of producing continuous the jet printing apparatus utilizing the advantages of selecting processing technology offering low cost, high volume methods of manufacture.
[0011] It is yet another object of the present invention to provide an apparatus and method for continuous ink jet printing that does not require electrostatic charging tunnels or deflection plates.
[0012] In accordance with an aspect of the invention, apparatus is provided for controlling ink in a continuous ink jet printer in which a continuous stream of ink is emitted from a nozzle wherein the apparatus comprises a reservoir of pressurized ink, an ink staging chamber having a nozzle bore to establish a continuous flow of ink in a stream, ink delivery means intermediate said reservoir and said staging chamber for communicating ink between said reservoir and said staging chamber, said channel means comprising a primary ink delivery channel and an adjacent secondary ink delivery channel; and a thermally actuated valve positioned, when closed, to block ink flow through said secondary channel and, when opened, to permit ink flow through said secondary channel, whereby opening and closing of said valve results in deflection of said ink stream between a print direction and a non-print direction.
[0013] In accordance with another aspect of the invention, there is provided a method of fabricating a continuous inkjet printhead having a series of inkjet devices each of which includes primary and secondary ink delivery channels, an ink staging chamber having a chamber wall with a nozzle bore aligned with said primary ink delivery channel and a thermally actuated valve positioned over said secondary delivery channel to control, by opening and closing of said valve, deflection of an ink stream emitted from said nozzle bore between print and non-print directions. The fabrication method comprises providing a silicon substrate having a front side and a back side; forming a series of first and second adjacent wells in the substrate corresponding to said primary and secondary ink delivery channels; and depositing a patterned thermally actuated valve device over each of said second wells. The method also includes depositing and patterning sacrificial material over said wells to form a volume corresponding to said ink staging chamber; depositing a chamber wall material over said sacrificial material to define an ink staging chamber wall; etching a nozzle bore in the chamber wall aligned with said first well; and removing said sacrificial material through said nozzle bore thereby forming said ink staging chamber with said valve device released within the chamber. The method further includes etching a channel through the back side of said substrate to said wells to form said primary and secondary ink delivery channels to said ink staging chamber.
[0014] These and other aspects, objects, features and advantages of the present invention will be more clearly understood and appreciated from a review of the following detailed description of the preferred embodiments and appended claims, and by reference to the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0015] In the drawings:
[0016] [0016]FIG. 1 shows a simplified block schematic diagram of one exemplary printing apparatus according to the present invention.
[0017] [0017]FIG. 2 shows in schematic form a cross-section of a segment of a continuous ink jet printhead illustrating principles of the present invention.
[0018] FIGS. 3 - 17 show in schematic form the steps employed in a method of producing a continuous ink jet printhead in accordance with a feature of the invention.
DETAILED DESCRIPTION OF THE INVENTION
[0019] The present description will be directed in particular to elements forming part of, or cooperating more directly with, apparatus in accordance with the present invention. It is to be understood that elements not specifically shown or described may take various forms well known to those skilled in the art.
[0020] Referring to FIG. 1, a continuous ink jet printer system includes an image source 10 such as a scanner or computer which provides raster image data, outline image data in the form of a page description language, or other forms of digital image data. This image data is converted to half-toned bitmap image data by an image processing unit 12 which also stores the image data in memory. A plurality of valve control circuits 14 read data from the image memory and apply time-varying electrical pulses to a set of electrically controlled micro-valves that are part of a printhead 16 . These pulses are applied at an appropriate time, and to the appropriate nozzle in the printhead, so that drops formed from a continuous ink jet stream will form spots on a recording medium 18 in the appropriate position designated by the data in the image memory.
[0021] Recording medium 18 is moved relative to printhead 16 by a recording medium transport system 20 , and which is electronically controlled by a recording medium transport control system 22 , which in turn is controlled by a micro-controller 24 . The recording medium transport system shown in FIG. 1 is a schematic only, and many different mechanical configurations are possible. For example, a transfer roller could be used as recording medium transport system 20 to facilitate transfer of the ink drops to recording medium 18 . Such transfer roller technology is well known in the art. In the case of page width printheads, it is most convenient to move recording medium 18 past a stationary printhead. However, in the case of scanning print systems, it is usually most convenient to move the printhead along one axis (the sub-scanning direction) and the recording medium along the orthogonal axis (the main scanning direction) in a relative raster motion.
[0022] Micro-controller 24 may also control an ink pressure regulator 26 and valve control circuits 14 . Ink is contained in an ink reservoir 28 under pressure. In the non-printing state, continuous ink jet drop streams are unable to reach recording medium 18 due to an ink gutter 17 that blocks the stream and which may allow a portion of the ink to be recycled by an ink recycling unit 19 . The ink recycling unit reconditions the ink and feeds it back to reservoir 28 . Such ink recycling units are well known in the art. The ink pressure suitable for optimal operation will depend on a number of factors, including geometry and thermal properties of the nozzles and thermal properties of the ink. A constant ink pressure can be achieved by applying pressure to ink reservoir 28 under the control of ink pressure regulator 26 .
[0023] The ink is distributed to the back surface of printhead 16 by an ink channel device 30 . The ink preferably flows through slots and/or holes etched through a silicon substrate of printhead 16 to its front surface, where a plurality of nozzles and heaters are situated. With printhead 16 fabricated from a silicon substrate, it is possible to integrate valve control circuits 14 with the printhead.
[0024] Turning to FIG. 2, a segment of printhead 16 is shown schematically in cross-section. In the illustration the printhead includes an ink staging chamber 40 having a nozzle bore 42 from which ink under pressure is emitted in a stream directed toward the recording medium 18 . The pressurized ink from reservoir 28 is communicated via the channel device 30 to the staging chamber 40 by ink delivery channel means 30 which, for each ink jet nozzle comprises a primary ink delivery channel 44 and an adjacent secondary ink delivery channel 46 . In the embodiment illustrated, a thermally actuated valve 50 , shown in solid line, is positioned within the staging chamber 40 over the secondary channel 46 thereby blocking the flow of ink through the secondary channel 46 . With the flow of ink through channel 46 blocked, the pressurized ink flowing through the primary channel 44 is emitted through nozzle bore 42 without deflection as stream 52 shown in solid line. The nozzle bore 42 is preferably axially aligned with the primary ink delivery channel 44 and the secondary ink delivery channel is axially offset from the primary channel in a direction opposite to the desired deflection direction of ink stream as represented by dotted outline 52 a. When valve 50 is thermally actuated by signals from valve control circuits 14 to raise up as shown by dotted lines 50 a , pressurized ink flows through secondary channel 46 creating a lateral flow through the staging chamber 40 that combines with the ink flowing axially through the primary channel 44 to the nozzle bore 42 . The result of this lateral flow it to cause the deflection of the stream 52 as shown in dotted line 52 a. Thus, opening and closing of the valve results in deflection of the ink stream between a print direction and a non-print direction depending on the position of the gutter 17
[0025] A method by which the printhead of FIG. 2 may be fabricated in accordance with a feature of the invention will now be described with reference to FIGS. 3 through 16. To begin the process, as shown in FIG. 3, an oxide layer 80 , preferably in the thickness range of from 0.1 to 1.0 micron, is formed on a silicon substrate 82 . This oxide layer is patterned and etched to form an array of rectangular shaped openings 84 as seen in the plan view of FIG. 4. The openings may be staggered as shown in order to allow for access to electrical contact terminals from opposite sides of the substrate. It will be appreciated that these figures are schematic in nature to illustrate the steps of the fabrication process and are not drawn to scale. A resist layer 86 is next applied to the substrate 82 as shown in FIG. 5 by a known spin coating technique and is lithographically patterned. This pattern is etched into the silicon substrate 82 to form substrate wells 90 and 92 in the substrate 82 preferably in the depth range of from 1 to 100 microns as shown in FIG. 6. These wells will ultimately become the primary and secondary ink delivery channels 44 and 46 , respectively. In the preferred embodiment illustrated in FIG. 6, well 90 is formed as a cylindrical hole while well 92 is formed as a rectangular slot, although it will be appreciated that other configurations may be employed.
[0026] In FIG. 7, the resist layer 86 is stripped and a conformal second oxide layer 94 is grown on the substrate 82 . Since the 2 nd oxide layer is thermally grown the growth takes place at the substrate 82 , 1 st oxide layer 80 interface. So realistically this is where the 2 nd oxide layer is formed, under the 1 st oxide layer with thickness in the range of from 0.1 to 1 micron. In FIG. 8, a first sacrificial layer 100 is deposited. The deposited thickness is enough to completely fill substrate wells 90 and 92 as well as the rectangular-shaped openings of modified oxide layer 80 . In the preferred embodiment this layer is polysilicon. Alternatively, polyimide may be used. The first sacrificial layer 100 is then made planar to oxide layer 80 in FIG. 9 by chemical mechanical polishing. The chemical mechanical polishing process is designed to etch the first sacrificial layer 100 and stop on the modified oxide layer 80 creating a planarized first sacrificial layer 100 a.
[0027] In FIG. 10, a third oxide layer 102 is then deposited preferably in the thickness range of from 0.1 to 1 micron. This is followed by deposition and patterning of a lower valve actuator layer 104 as shown in FIGS. 10 and 11. The criteria for the lower thermal actuator layer 104 are i) high coefficient of thermal expansion; ii) resistivity between 3-1000 μΩ-cm; iii) high modulus of elasticity; iv) low mass density; and v) low specific heat. Metals such as aluminum, copper, nickel, titanium, and tantalum, as well as alloys of these metals meet these requirements. In the preferred embodiment, the metal is an aluminum alloy. In FIG. 12, an upper actuator layer 106 is then deposited and then removed in the areas above the planarized first sacrificial layer 100 a except for the material deposited on the lower actuator layer 104 and a small protective region 106 a adjacent the lower actuator layer 104 . The third oxide layer 102 not protected by the upper actuator layer 106 is also removed during this step. The criteria for the upper actuator layer 106 are i) low coefficient of thermal expansion; and ii) the layer should be electrically insulating. Dielectric materials such as oxides and silicon nitride meet these requirements. In the preferred embodiment, the dielectric material is an oxide. The protective region 106 a, along with the third oxide layer 102 , completely encloses the lower actuator layer 90 , protecting it from the ink.
[0028] In FIG. 13 a, a second sacrificial layer 110 is deposited and lithographically patterned. The second sacrificial layer encloses the rectangular shaped opening 84 (FIG. 13 b ) including the thermally actuated valve 50 and substrate well 90 , 92 . In the preferred embodiment, this material is photoimageable polyimide. This material can be spun on and patterned by masked exposure and development. The material is then final cured at 350 C. to provide a layer preferably in the thickness range 2-10 microns. A slight etchback in an oxygen plasma can be performed to adjust the final thickness and descum the surface. After subsequent removal, the volume occupied by this second sacrificial layer will become the in ink staging chamber 40 (FIG. 2).
[0029] In FIG. 14, a thick chamber wall layer 112 is then deposited with a preferred thickness so that all regions between the second sacrificial layer 110 will be filled up and result in a thickness on top of the second sacrificial layer 110 that is greater than 1 micron. In the preferred embodiment this material is an oxide layer. Other materials such as silicon nitride or oxynitrides can be used as well as combinations of this material to form the chamber wall layer 112 . This layer can then be planarized by chemical mechanical polishing with a preferred final thickness of the chamber wall layer 112 above the second sacrificial layer 110 to be greater than 1 micron.
[0030] In FIG. 15, the chamber wall layer 112 is next patterned and etched to form the nozzle bore 42 for the ejection of ink. The etch process also opens up a through-hole 116 in the chamber wall as well as in the upper actuator layer 106 so that electrical contact can be made to the lower actuator layer 104 which in turn activates the thermally actuated valve 50 . In FIG. 16, the back side of the silicon substrate 82 , is then patterned and ink feed channels 30 are etched into the silicon substrate 10 until they meet the liner oxide 94 coating the bottoms of the wells 90 and 92 . The first sacrificial layer 100 a , and second sacrificial layer 110 are then removed through the nozzle bore 42 with plasma etchants which do not attack the chamber wall layer 112 . This step will create the ink staging chamber 40 , clear away the sacrificial layer from wells 90 and 92 , and release the thermal actuator 50 (FIG. 2) comprised of lower actuator layer 104 and upper actuator layer 106 . For polyimide sacrificial layers an oxygen plasma is used. For polysilicon sacrificial layers XeF 2 (Xenon Difluoride) or SF 6 (Sulfur Hexafluoride) is used. Finally the liner oxide 94 coating the bottoms of the wells 90 and 92 is removed by etching from the back of the silicon substrate 10 thereby creating the primary and secondary ink delivery channels 44 and 46 (FIG. 17). Once the thermal valve actuator is released upon removal of the sacrificial layers, the bottom layer 104 of the actuator will be in a state of tensile stress that will cause the actuator to bend towards the opening of the secondary ink delivery channel thereby minimizing any leakage while the actuator is in the off (closed) state. More importantly, some minimal leakage can be tolerated in the off state. Such minimal leakage will cause a slight deflection of the ink stream 52 resulting in an initial deflection bias. However, this will not significantly affect the operation since what is most important is the change in deflection of the ink stream between the closed and open state of the thermal actuator.
[0031] The invention has been described in detail with particular reference to certain preferred embodiments thereof, but it will be understood that variations and modifications can be effected within the spirit and scope of the invention.
PARTS LIST 10 image source 12 image processing unit 14 valve control circuits 16 printhead 17 ink gutter 18 recording medium 20 recording medium transport system 22 transport control system 24 micro-controller 26 ink pressure regulator 28 ink reservoir 30 ink channel device 40 ink staging chamber 42 nozzle bore 44 primary ink delivery channel 46 secondary ink delivery channel 50 thermally actuated valve 52 ink stream 80 first oxide layer 82 silicon substrate 84 openings 86 resist layer 90, 92 substrate wells 94 conformal oxide layer 100 first sacrificial layer 104 lower thermal actuator layer 106 upper actuator layer 110 second sacrificial layer 112 chamber wall layer 116 through hole | A continuous inkjet printer in which a continuous ink stream is deflected at the printhead nozzle bore without the need for charged deflection plates or tunnels. The printhead includes a primary ink delivery channel which delivers a primary flow of pressurized ink through an ink staging chamber to the nozzle bore to create an undeflected ink stream from the printhead. A secondary ink delivery channel adjacent to the primary channel is controlled by a thermally actuated valve to selectively create a lateral flow of pressurized ink into the primary flow thereby causing the emitted ink stream to deflect in a direction opposite to the direction from which the secondary ink stream impinges the primary ink stream in the ink staging chamber. A method of fabricating the printhead includes layering of the thermally actuated valve over the secondary ink delivery channel formed in a silicon substrate and creating the ink staging chamber over the delivery channels with sacrificial material which is later removed through the nozzle bore etched into the chamber wall formed over the sacrificial material. | 1 |
BACKGROUND OF THE INVENTION
U.S. Pat. No. 4,105,776, issued Aug. 8, 1979, discloses, inter alia, amides of certain mercaptoacyl amino acids. Included among the amides disclosed by the patent are those having the formula ##STR1## wherein n is 0, 1 or 2; R a is hydrogen or alkyl; R b is hydrogen, alkyl, phenyl, substituted phenyl, mono-, di- or tri-phenylalkyl, alkylthiomethyl, phenylalkylthiomethyl, alkanoylamidomethyl, acyl, and others; and R c is hydrogen or hydroxy.
British patent specification No. 2,014,132, published Aug. 22, 1979 discloses, inter alia, amides, N-alkylamides, and N,N-dialkylamides (wherein the alkyl group(s) can be substituted with an amino or hydroxy substituent) of certain mercaptoacyl amino acids (the mercaptoacyl side chain contains a trifluoromethyl or pentafluoroethyl substituent).
The above described compounds inhibit the conversion of angiotensin I to angiotensin II in mammals, and are, therefore, useful in the treatment of hypertension.
BRIEF DESCRIPTION OF THE INVENTION
Compounds having the formula ##STR2## have hypotensive activity. In formula I, and throughout the specification, the symbols are as defined below.
R 1 is hydrogen, alkyl, aryl, arylalkyl or a hydrolyzable acyl protecting group such as ##STR3## wherein R 5 is alkyl or aryl;
R 2 is hydrogen, alkyl, trifluoromethyl or pentafluoroethyl;
R 3 is --CH 2 --, --S--, --CH(OH)--, --CH(O-alkyl)--, --CH(O-aryl)--, --CH(S-alkyl)--, --CH(S-aryl)--, --C(O-alkyl) 2 --, --C(S-alkyl) 2 --, ##STR4## --CCl 2 --, --CF 2 --, --CHCl--, or --CHF-- and R 4 is --CH 2 -- or --S--, with the proviso that if R 4 is --S--, R 3 is --CH 2 --; or together, R 3 and R 4 can be --CH═CH; and
n is 0, 1 or 2.
The term "aryl", as used throughout the specification either by itself or as part of a larger group, refers to phenyl or phenyl substituted with one, two or three halogen, alkyl, alkoxy, hydroxy, ##STR5## nitro, amino, alkylamino, dialkylamino, trifluoromethyl, cyano or carboxyl groups. Phenyl is the preferred aryl group.
The term "alkyl", as used throughout the specification either by itself or as part of a larger group, refers to groups having 1 to 8 carbon atoms. Alkyl groups having 1 to 3 carbon atoms are preferred.
The term "alkoxy", as used throughout the specification either by itself or as part of a larger group, refers to groups having 1 to 8 carbon atoms. Alkoxy groups having 1 to 3 groups atoms are preferred.
The term "halogen", as used throughout the specification either by itself or as part of a larger group, refers to fluorine, chlorine, bromine and iodine. The preferred halogen groups are chlorine and bromine.
DETAILED DESCRIPTION OF THE INVENTION
The compounds of formula I are useful as hypotensive agents. They inhibit the conversion of the decapeptide angiotensin I to angiotensin II and, therefore, are useful in reducing or relieving angiotensin related hypertension. The action of the enzyme renin on angiotensinogen, a pseudoglobulin in blood plasma, produces angiotensin I. Angiotensin I is converted by angiotensin converting enzyme (ACE) to angiotensin II. The latter is an active pressor substance which has been implicated as the causative agent in various forms of hypertension in various mammalian species, e.g., rats and dogs. The compounds of this invention intervene in the angiotensinogen→(renin)→angiotensin I→(ACE)→angiotensin II sequence by inhibiting angiotensin converting enzyme and reducing or eliminating the formation of the pressor substance angiotensin II. Thus by the administration of a composition containing one or a combination of the compounds of this invention, angiotensin dependent hypertension in the species of mammal suffering therefrom is alleviated. A single dose, or preferably two to four divided daily doses, provided on a basis of about 0.1 to 100 mg. per kilogram of body weight per day, preferably about 1 to 15 mg. per kilogram of body weight per day is appropriate to reduce blood pressure. The substance is preferably administered orally, but parenteral routes such as the subcutaneous, intramuscular, intravenous or intraperitoneal routes can also be employed.
The compounds of this invention can also be formulated in combination with a diuretic for the treatment of hypertension. A combination product comprising a compound of this invention and a diuretic can be administered in an effective amount which comprises a total daily dosage of about 30 to 600 mg., preferably about 30 to 300 mg. of a compound of this invention, and about 15 to 300 mg., preferably about 15 to 200 mg. of the diuretic, to a mammalian species in need thereof. Exemplary of the diuretics contemplated for use in combination with a compound of this invention are the thiazide diuretics, e.g., chlorthiazide, hydrochlorthiazide, flumethiazide, hydroflumethiazide, bendroflumethiazide, methychlothiazide, trichlormethiazide, polythiazide or benzthiazide as well as ethacrynic acid, ticrynafen, chlorthalidone, furosemide, musolimine, bumetanide, triametrene, amiloride and spironolactone and salts of such compounds.
The compounds of formula I can be formulated for use in the reduction of blood pressure in compositions such as tablets, capsules or elixirs for oral administration or in sterile solutions of suspensions for parenteral administration. About 10 to 500 mg. of a compound or mixture or compounds of formula I is compounded with a physiologically acceptable vehicle, carrier, excipient, binder, preservative, stabilizer, flavor, etc., in a unit dosage form as called for by accepted pharmaceutical practice. The amount of active substance in these compositions or preparations is such that a suitable dosage in the range indicated is obtained.
The compounds of this invention are readily prepared from the corresponding carboxylic acid having the formula ##STR6## wherein Y is alkyl, aryl or a protecting group, preferably an acyl group. The conversion of an acid of formula II to the corresponding hydroxamic acid having the formula: ##STR7## wherein Y' is alkyl, aryl or hydrogen can be accomplished by reacting the precursor acid successively with an alkyl haloformate (e.g., ethyl chloroformate) and hydroxylamine. The addition of alkyl haloformate can be carried out in the presence of an organic base (e.g., triethylamine) at a reduced temperature. The reaction can be run in an anhydrous organic solvent, preferably an ethereal solvent such as tetrahydrofuran. The subsequent reaction with hydroxylamine can likewise be run at a reduced temperature in an organic solvent, preferably a dipolar aprotic solvent such as dimethylformamide. In the products of formula III, Y' will be hydrogen if in the starting material of formula II, Y is acyl.
Those products of formula I wherein R 1 is a hydrolyzable acyl protecting group can be prepared from the corresponding mercapto product of formula I using art-recognized acylation techniques.
The compounds of formula II, and methods for their preparation, have been described in the patent and nonpatent literature.
Those compounds of formula II wherein R 3 is --CH 2 -- or --CH(OH)--, R 4 is --CH 2 -- and R 2 is hydrogen or alkyl, are described in U.S. Pat. Nos. 4,046,889, issued Sept. 6, 1979; 4,105,776, issued Aug. 8, 1978; and 4,154,840, issued May 15, 1979.
Those compounds of formula II wherein R 3 is --CH 2 --, --CCl 2 --, --CF 2 --, --CHCl--, or --CHF--, R 4 is --CH 2 --, and R 2 is hydrogen, alkyl or trifluoromethyl are disclosed in U.S. Pat. No. 4,154,935, issued May 15, 1979.
Those compounds of formula II wherein R 3 and R 4 together are --CH═CH-- and R 2 is hydrogen or alkyl are disclosed in U.S. Pat. Nos. 4,129,566, issued Dec. 12, 1978 and 4,154,942, issued May 15, 1979.
Those compounds of formula II wherein R 3 is --S-- and R 4 is --CH 2 -- or R 3 is --CH 2 -- and R 4 is --S--, and R 2 is hydrogen or alkyl are disclosed in Belgian Pat. No. 861,454, issued June 2, 1978.
Those compounds of formula II wherein R 2 is trifluoromethyl or pentafluoroethyl and R 3 and R 4 each is --CH 2 -- or --S-- or R 3 and R 4 together are --CH═CH--, are disclosed in British patent specification No. 2,014,132, published Aug. 22, 1979.
Those compounds of formula II wherein R 3 is --CH(O-alkyl)--, --CH(O-aryl)--, --CH(S-alkyl)--, or --CH(S-aryl)--, R 4 is --CH 2 -- and R 2 is hydrogen or alkyl are disclosed in United States patent application Ser. No. 52,691, filed July 2, 1979, the disclosure of which is incorporated herein by reference.
Those compounds of formula II wherein R 3 is --C(O-alkyl) 2 --, --C(S-alkyl) 2 --, ##STR8## and R 4 is --CH 2 -- are disclosed in United States patent application Ser. No. 99,164, filed Nov. 30, 1979, the disclosure of which is incorporated herein by reference.
The products of formula I have at least one asymmetric carbon atom. If R 2 is other than hydrogen, the products have two asymmetric carbon atoms. The compounds, therefore, exist in stereoisomeric forms or in racemic or diastereomeric mixtures thereof. All of these are within the scope of this invention. The synthesis described above can be run using reactants that are racemic or diastereomeric mixtures or stereoisomers. When the reactants are racemic or diasteromeric mixtures, the stereoisomers of the resulting product can be separated using art-recognized techniques. The L-isomer with respect to the carbon of the amino acid constitutes the preferred isomeric form.
The following examples are specific embodiments of this invention.
EXAMPLE 1
(S)-N-Hydroxy-1-(3-mercapto-2-methyl-1-oxopropyl)-L-prolinamide
A solution of (S)-1-[3-(acetylthio)-2-methyl-1-oxopropyl]-L-proline (13.5 g, 0.05 mole) and dry, distilled, triethylamine (5.1 g, 0.05 mole) in tetrahydrofuran (250 ml) is cooled, with stirring, to -15° C. and a solution of ethyl chloroformate (5.4 g, 0.05 mole) in tetrahydrofuran (50 ml) is added dropwise as the reaction temperature is maintained at -15° C. Following the addition, stirring was continued, at -15° C., for 30 minutes. After warming to 0° C., a solution of freshly prepared hydroxylamine* (ca. 5.8 g, 0.175 mole) in dimethylformamide (230 ml) is added dropwise, at a reaction temperature of 0° C., over a period of 5 minutes. The reaction mixture is stirred at 0° C. for three hours following the addition; it is then acidified to a pH of 2 by the addition of concentrated hydrochloric acid (ca. 13 ml). After the addition of ethyl acetate (500 ml), water is added (30 ml) to effect solution of the solids still in suspension. The acidic aqueous phase is separated and extracted with ethyl acetate (two 25 ml portions). The combined organic solutions are washed with brine and dried (MgSO 4 ). After removal of the solvents in vacuo, the waxy solid residue (14 g) is triturated with ethyl acetate (50 ml), followed by trituration with acetonitrile (two 25 ml portions) to give 2.7 g of solid, melting point 145°-148° C., dec. TlC, silica gel, CH 2 Cl 2 /MeOH/HOAc (90:5:5); one spot, Rf. 0.30. (Visualized with FeCl 3 , or nitroprusside reagent, or phosphomolybdic acid plus heat). It is recrystallized from 400 ml of ethyl acetate with a recovery of 2.1 g melting point 154°-155° C., dec. An aqueous solution shows a trace of insolubles. The solid is dissolved in 100 ml of double-distilled water, millipore filtered, and lyophilized to give 1.95 g of the title compound, melting point 154°-155° C., dec. Analysis, calc'd for C 9 H 16 N 2 O 3 S.1/4 H 2 O: C, 45.64; H, 7.02; N, 11.83; S, 13.54; SH, 13.96. Found: C, 45.98; H, 7.15; N, 11.68; S, 13.16; SH, 13.66.
EXAMPLES 2-18
Following the procedure of Example 1, but substituting the compound listed in column I for (S)-1-[3-(acetylthio)-2-methyl-1-oxopropyl]-L-proline, yields the compound listed in column II.
__________________________________________________________________________ Column I Column II__________________________________________________________________________2. 1-[3-(acetylthio)-2-methyl-1-oxopropyl]- N-hydroxy-1-(3-mercapto-2-methyl-1- 4-methoxy-L-proline oxopropyl)-4-methoxy-L-prolinamide3. 1-[3-(acetylthio)-2-methyl-1-oxopropyl]- N-hydroxy-1-(3-mercapto-2-methyl-1- 4,4-dimethoxy-L-proline oxoproyl)-4,4-dimethoxy-L-prolinamide4. 1-[3-(acetylthio)-2-methyl-1-oxopropyl]- N-hydroxy-1-(3-mercapto-2-methyl-1- 4-chloro-L-proline oxopropyl)-4-chloro-L-prolinamide5. 1-[3-(acetylthio)-2-methyl-1-oxopropyl]- N-hydroxy-1-(3-mercapto-2-methyl-1- 4-fluoro-L-proline oxopropyl)-4-fluoro-L-prolinamide6. 1-[3-(acetylthio)-2-methyl-1-oxopropyl]- N-hydroxy-1-(3-mercapto-2-methyl-1- 4,4-dichloro-L-proline oxopropyl-4,4-dichloro-L-prolinamide7. 1-[3-(acetylthio)-2-methyl-1-oxopropyl]- N-hydroxy-1-(3-mercapto-2-methyl-1- 4,4-difluoro-L-proline oxopropyl)-4,4-difluoro-L-prolinamide8. 1-[3-(acetylthio)-2-methyl-1-oxopropyl]- N-hydroxy-1-(3-mercapto-2-methyl-1- 4-hydroxy-L-proline oxopropyl)-4-hydroxy-L-prolinamide9. 3-[3-(acetylthio)-2-methyl-1-oxopropyl]- N-hydroxy-3-(3-mercapto-2-methyl- L-thiazolidine-4-carboxylic acid 1-oxopropyl)-L-thiazolidine-4-carboxamide10. 3-[3-(acetylthio)-2-methyl-1-oxopropyl]- N-hydroxy-3-(3-mercapto-2-methyl-1- L-thiazolidine-2-carboxylic acid oxopropyl)-L-thiazolidine-2-carboxamide 1-[3-(acetylthio)-2-methyl-1-oxopropyl]- N-hydroxy-1-(3-mercapto-2-methyl-1- 4,4-ethylenedioxy-L-proline oxopropyl)-4,4-ethylenedioxy-L-prolinamide 1-[3-(acetylthio)-2-methyl-1-oxopropyl]- N-hydroxy-1-(3-mercapto-2-methyl-1- 4,4-ethylenedithio-L-proline oxopropyl)-4,4-ethylenedithio-L-prolinamide 1-[3-(acetylthio)-2-(trifluoromethyl)-1- N-hydroxy-1-[3-mercapto-2-(trifluoromethyl)- oxopropyl]-L-proline 1-oxopropyl]-L-prolinamide 1-[3-(acetylthio)-2-(trifluoromethyl-1- N-hydroxy-1-[3-mercapto-2-(trifluoro- oxopropyl]-L-3,4-dehydroproline methyl)-1-oxopropyl]-L-3,4-dehydropro- linamide. 1-[3-(acetylthio)-2-methyl-1-oxopropyl]- N-hydroxy-1-(3-mercapto-2-methyl-1- 4-(methylthio)-L-proline oxopropyl)-4-(methylthio)-L-prolinamide 1-[3-(acetylthio)-2-methyl-1-oxopropyl]- N-hydroxy-1-(3-mercapto-2-methyl-1- 4-(phenyloxy)-L-proline oxopropyl)-4-(phenyloxy)-L-prolinamide 1-[3-(acetylthio)-2-methyl-1-oxopropyl]- N-hydroxy-1-(3-mercapto-2-methyl-1-oxo- 4-(phenylthio)-L-proline propyl)-4-(phenylthio)-L-prolinamide 1-[3-(acetylthio)-2-methyl-1-oxopropyl]- N-hydroxy-1-(3-mercapto-2-methyl-1-oxo- 4,4-(dimethylthio)-L-proline propyl)-4,4-(dimethylthio)-L-prolinamide__________________________________________________________________________ | Hydroxamic acid derivatives of certain mercaptoacyl amino acids inhibit the conversion of angiotensin I to angiotensin II in mammals and are useful for the treatment of hypertension. | 2 |
BACKGROUND OF THE INVENTION
The present invention relates to control devices for actuators. More particularly, the present invention relates to a control device for an actuator of construction equipment.
In conventional circuits used to control, for example, hydraulic cylinders, providing for stable and continuous operation has proven highly problematic. This difficulty is heightened by the constraints involved in high-speed engine operation. Attempts have been made to solve these problems using known circuits.
Turning now to FIG. 5, an example of one of such conventional circuits is shown. A main pump 12 is driven by an engine 11 to feed pressurized fluid through a discharge port 12 and an oil feed channel 13 to inputs of a plurality (three in the illustrated embodiment) of control valves 14a, 14b, and 14c. Directional control valve 14a is shown in schematic detail. Directional control valves 14b and 14c are identical to control valve 14a, and internal details thereof are omitted.
Directional control valves 14a, 14b, and 14c feed working fluid to actuators 15a, 15b, and 15c. The direction and volume of flow of the fluid is controlled by respective spools of control valves 14a, 14b, and 14c. Working fluid discharged from actuators 15b and 15c returns to a tank line 16, through an oil return channel and control valves 14a, 14b, and 14c.
Control valve 14a controls the feeding of pressurized fluid on upper oil feed channel 22 and lower oil feed channel 23 to an actuator 15a, a hydraulic cylinder. Actuator 15a is the target cylinder (the object to be controlled).
A pilot pump 17 is driven by engine 11 to feed pressurized fluid on a pilot pressure line 18 to a plurality of pilot valves 19a, 19b, and 19c.
Each pilot valve 19a, 19b, and 19c is controlled by its respective operating lever 20a, 20b, and 20c. Operating levers 20a, 20b, and 20c are controlled by an operator of the construction equipment.
Pilot valves 19a, 19b, and 19c control the flow of pressurized fluid from pilot pressure line 18 to pilot pressure receiving sections of respective pilot lines a1/a2, b1/b2 and c1/c2.
In its quiescent condition shown in the figure, operating lever 20a is in its neutral (unactuated) position. In this position, the spool of control valve 14a blocks the flow of pressurized fluid to and from upper and lower oil feed channels 23 and 22. A return channel 26 in control valve 14a permits return flow of fluid from a common return line 27 carrying discharge fluid from control valves 14b and 14c.
In addition to its quiescent condition, control valve 14a may be displaced into one of two operating positions. When operating lever 20a of pilot valve 19a is biased in the direction a1, the spool of control valve 14a is displaced upward by pilot pressure from pilot line a1 from its neutral position shown to a direct feed position in which metering oil channel 21 connects discharged fluid from upper oil feed channel 23 to a tank line 16, and connects fluid from check valve 29 to lower oil feed channel 22. This condition urges the piston in actuator 15a in the upward direction of moving an element (not shown) of the equipment of which the present control system is a part. In this position, common return line 27 is blocked by a return channel 26, which is closed in this position. A return-side throttle 25 restricts the flow of fluid therethrough to control the rate at which the piston of actuator 15a is capable of moving.
The second position of the spool of control valve 14a is in the downward direction. In this direction, the feeding and return flows from upper and lower oil feed channels 23 and 22 are reversed, compared to the first direction, whereby the piston of actuator 15a is moved downward. As in the first position, return flow of fluid from common return line 27 is blocked.
In the prior-art device, return-side throttle 25 is a fixed-diameter aperture whose size, and therefore whose maximum fluid flow rate, is fixed during manufacture of control valve 14a. The maximum fluid flow rate through control valve 14a is therefore determined at manufacture, and no provision exists to vary the rate at which the piston of actuator 15a moves. Although meter-in oil channel 21 is unrestricted, the flow rate therethrough is controlled by return-side throttle 25.
The maximum flow of oil that can be supplied by main pump 12 is proportional to the speed of rotation of engine 11. Stroke control of control valve 14a remains constant in relation to the angular degrees of actuation of operating lever 20a, regardless of quantity of available from main pump 12.
When engine speed is reduced, or other actuator spool or spools 14b, 14c are operated, the effect is the same as when the aperture of return-side throttle 25 is reduced because, even with control valve 14a set at full stroke the aperture of return-side throttle 25 is constant.
Under some conditions of inertial or gravity load, the aperture-limited flow of oil to actuator 15a may be insufficient to produce the required motion, or resist input forces. This may cause actuator 15a to void thereby produce temporary stoppage and generally unstable operation.
Such problems with required cylinder speed exceeding the available oil supply flow, and concomitant loss of control result in high levels of dissatisfaction among users.
Attempts have been made to simply increase the aperture size of the return-side throttle in order to eliminate the above drawbacks. This is not and adequate solution although it may prevent temporary stoppage of the system during operation. Problems of insufficient oil flow still remain during low engine speed or during simultaneous operation with other actuators.
Similarly, during high engine speed operation when actuator 15a is operated alone, large quantities of oil are restricted by return-side throttle 25, resulting in excessive heat generation.
OBJECTS AND SUMMARY OF THE INVENTION
In order to solve the above problem, the present invention controls the aperture of the oil return channel of a target actuator. This controls inertial load and power load, and prevents voiding of the target actuator. Similarly it reduces the calorific value (or heat produced per unit mass due to complete combustion) of fluid within the oil feed channels.
Accordingly, it is an object of the present invention to provide a control device for an actuator for construction equipment to control the aperture of the oil return channel of a target actuator.
It is a further object of the present invention to provide a control device for an actuator for construction equipment which controls inertial load and power load.
It is a still further object of the present invention to provide a control device for an actuator for construction equipment which prevents voiding of a target actuator and reduces calorific value of pressurized fluid within oil channels.
To satisfy the above objects, the present invention controls the flow capacity of the oil return channel of an actuator. This controls inertial load and power load, and prevents voiding of the target actuator. Similarly it reduces the heating of fluid within the oil feed channels.
Briefly stated, there is provided a device for controlling an actuator of construction equipment in which inertial load and power load are to be controlled by means of directional control valves which are modulated by respective operating levers to prevent voiding of a target actuator, and reduce heat generated in its return oil channel by means of controlling the aperture of the return oil channel.
According to an embodiment of the invention, there is provided a device for controlling an actuator of construction equipment by means of directional control valves which are modulated by respective operating levers, wherein, a meter-out circuit is provided between an actuator to be controlled and a tank line, said meter-out circuit being separated from a meter-in circuit which is connected to said control valves; and said meter-out circuit includes a meter-out valve having a throttle position and a large aperture position, said throttle position being adjusted by external signals which correspond to the strokes of the respective operating levers.
The above, and other objects, features and advantages of the present invention will become apparent from the following detailed description of the present invention.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a hydraulic circuit diagram of an actuator control device of construction equipment according to an embodiment of the present invention.
FIG. 2 is a characteristic diagram showing correlation between the area of the aperture of a meter-out valve used in the control device and its spool stroke and also showing correlation between the spool stroke and pilot pressure according to an embodiment of the present invention.
FIG. 3 is a diagram illustrating correlation between external signals representing pilot pressure to the meter-out valve and operating stroke of a lever for operating an actuator according to an embodiment of the present invention.
FIG. 4 is a diagram illustrating correlation between limiter pressure of the pilot pressure and engine speed which also illustrates correlation between limiter pressure and the maximum strokes of the operating levers for operating the other actuators according to an embodiment of the present invention.
FIG. 5 is a prior art hydraulic circuit diagram of an actuator control device of construction equipment.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring to FIG. 1, lower oil feed channel 23 of actuator 15a, which is the actuator to be controlled, includes a check valve 31. Lower oil feed channel 23 is connected to an input side of a meter-out valve 32. An output side of meter-out valve 32 is connected to tank line 16.
Directional control valve 14a, controls actuator 15a, whose piston is the element being controlled. Meter-out valve 32 is controlled by balancing the return force of a spring 34 and an external force Pi on an external signal line 33. The external force is produced in a pilot pressure controller 41 in response to pilot pressures applied thereto controlled by pilot valves 19a, 19b and 19c. Pilot pressure directly from pilot pump 17 is connected to an input of pilot pressure controller 41.
Unlike a conventional fixed throttle meter-out valve 32 of the present invention is controlled independently of the position of control valve 14a between a closed position, corresponding to the quiescent position of the prior-art embodiment of FIG. 5, a throttled position, corresponding to the first position of FIG. 5, and a non-throttled position, corresponding to the second position of FIG. 5. Independent control of meter-out valve 32 permits control of return flow that responds proportionately to engine speed and load requirements in a flexible manner not possible with the fixed aperture of return-side throttle 25. A check valve 31 in upper oil feed channel 23 prevents oil return to control valve 14a.
With the conventional circuits of FIG. 5, return-side throttle 25 in meter-out oil channel 24, of control valve 14a, is required because an independently controlled meter-out valve 32 having an adjustable throttle position is absent.
Since return line 35 from meter-out valve 32 is directly connected to tank line 16, permitting oil to return there through to the tank, it is unnecessary to return the oil to control valve 14a.
Pilot pressure controller 41, is included between a pilot pressure line 18 and pilot pump 17. External signal line 33 applies control forces Pi to meter-out valve 32 from pilot pressure controller 41 for controlling meter-out valve 32 according to the strokes of operating levers 20a, 20b, and 20c.
Pilot pressure controller 41 receives pilot pressures on pilot lines 42, 43, and 44 produced by actuation of operating levers 20a, 20b, and 20c, respectively of pilot valves 19a, 19b, and 19c. An engine speed detector 45, connected to engine 11, produces a signal proportional to engine speed which is connected on a signal line 46 to pilot pressure controller 41.
Control valve 14a is urged from the neutral position shown in the drawing to its upper position by pressure from pilot line a1 produced by manually moving the operating lever of pilot valve 19a in the direction a1. Working fluid is fed from meter-in oil channel 21 through oil feed channel 22 to the lower end of actuator 15a. This urges the piston of actuator 15a in the upward direction.
At that time, return oil displaced from the upper side of the piston of actuator 15a by the upward displacement of actuator 15a flows through either the throttled channel or the fully open channel, as selected by the position assumed by meter-out valve 32, under control of pilot pressure signals Pi from pilot pressure controller 41. The fluid from meter-out valve 32 is discharged through return line 35 to tank line 16.
When control valve 14a is shifted by pilot pressure from pilot line a2 the lower position working fluid is fed through control valve 14a upper oil feed channel 23 and check valve 31 directly fed into the upper side of. This urges the spool of actuator 15a into its retracted position.
During retraction, oil displaced from the lower side of actuator 15a is discharged through oil channel 22 and control valve 14a to tank line 16.
Referring now to FIG. 2, a correlation is shown between the area of the spool aperture of meter-out valve 32 of the present invention and its spool stroke as well as correlation between spool stroke of meter-out valve 32 and pilot pressure.
Referring now to FIG. 3, a correlation is shown between external signals representing pilot pressure Pi, which corresponds to the pilot pressure mentioned above, and the operating stroke of the operating lever of pilot valve 19a for actuator 15a.
Referring now to FIG. 4, a correlation is shown between limiter pressure which exists in relation to pilot pressure Pi and engine speed detected by sensor 45 as well as correlation between the maximum degree of the strokes of the operating levers of pilot valves 19b/19c for the other actuators and limiter pressure.
Referring again to FIGS. 2 to 4, when actuator 15a that includes meter-out valve 32 is operated alone, the lever-operating strokes for the other actuators are zero. Therefore, the maximum value on the solid line representing characteristic values of limiter pressure shown in the right graph of FIG. 4 is the limiter pressure actually applied, and a value which is on the upper line (line I) representing limiter pressures corresponding to an arbitrary engine speed is adopted as a limiter value in FIG. 3.
When actuators 15b/15c are operated simultaneously, the pressure of the limiter changes according to the degree of the operation stroke of their operating levers in such a manner as to smoothly deviate from the line I towards line II in FIG. 4.
Respective terminal points D' and G' on the upper limit line (line I) and the lower limit line (line II) of limiter pressures are slightly greater in this case than the lower limit (pressure C) for lever modulation shown in FIG. 3.
Referring now specifically to FIG. 3, the operating lever of pilot valve 19a for actuator 15a is operated within the modulation range between lever stroke points E and F in order to control pilot pressure Pi between pressure point C, which is identical to the valve opening pressure of meter-out valve 32, and pressure point D, which is identical to the full aperture pressure.
Referring now also to FIG. 4, when the engine speed is low at the same time that the operating lever for actuator 15a is operated to its full stroke, i. e. point F, the maximum value of pilot pressure Pi shown in FIG. 3 is limited by limiter pressure defined by line I in FIG. 4. In cases where the engine speed is low and another actuator or other actuators are operated by means of their respective operating levers, the maximum value of pilot pressure Pi shown is also limited by limiter pressure which is determined by either line II in FIG. 4 or intermediate characteristics between lines I and II. Therefore, instead of being fully opened, meter-out valve 32 is maintained at the throttle position corresponding to the limiter pressure as shown in FIG. 2 and consequently prevents voiding of actuator 15a which may otherwise be caused by insufficient working fluid.
When the engine speed is sufficiently high and the other actuators 15b/15c remain unoperated, the limiter value is at point D and identical to the full aperture pressure, wherein meter-out valve 32 is fully open. Since a large quantity of oil is available to flow without being throttled, there is no danger of generation of excessive heat.
Having described preferred embodiments of the invention with reference to the accompanying figures, it is to be understood that the invention is not limited to those precise embodiments, and that various changes and modifications may be effected therein by one skilled in the art without departing from the scope or spirit of the invention as defined in the appended claims. | A control valve feeds pressurized fluid for moving an actuator in first and second directions. A meter-out valve controls return flow of pressurized fluid from the actuator during actuation in the second direction. The meter-out valve is controlled by a pilot pressure controller independently of the actuator in response both to pilot pressures and to engine speed. The meter-out valve includes both a restricted channel and an unrestricted channel. The restricted channel, and the unrestricted channel are selectively connected dependent on the pilot pressures and the engine speed to supply sufficient fluid flow to permit stable operation of the actuator. | 4 |
FIELD OF THE INVENTION
[0001] This invention relates to a solar blanket roller assembly and, in particular, a solar blanket roller assembly which is intended to be installed below the deck of a pool.
BACKGROUND OF THE INVENTION
[0002] In the past, solar blankets have been used to cover swimming pools in order to reduce the amount of heat lost from the pool. Typically, the solar blanket has a size and shape corresponding to the surface of the pool. The solar blanket is put on the surface of the pool when the pool is not in use. When the pool is intended to be used, the solar blanket is typically rolled up onto a roller shaft. Typically, there are wheels at each end of the roller shaft and the entire roller assembly is rolled along the top of the pool deck. When the solar blanket has been removed from the pool surface, the entire roller assembly is moved away from the pool area. When it is desired to place the solar blanket back onto the surface of the pool the entire roller assembly is rolled to a position adjacent to the pool surface and the solar blanket is unrolled from the roller shaft and put back onto the surface of the pool. Because the roller assembly can be operated only on the top of the pool deck, it is an inconvenience to move the entire roller assembly away from and back to the pool area. Also, with the roller assembly on top of the deck, it takes up room that could otherwise be used for other activities. Also, the roller assembly is not particularly pleasing to look at, either when the solar blanket is rolled up or when it is unrolled.
SUMMARY OF THE INVENTION
[0003] Accordingly, it is an object of this invention to at least partially overcome the disadvantages of the prior art. Thus, it is an object of this invention to provide an improved type of solar blanket roller assembly which is installed below the deck of a pool.
[0004] Accordingly, in one of its objects, this invention resides in a below-deck solar blanket roller assembly comprising: a rotatable roller shaft for rolling and unrolling a solar blanket, the shaft having first and second ends and a longitudinal axis extending in a longitudinal direction; a non-rotatable protective casing having first and second ends, wherein the casing is spaced radially from the roller shaft, surrounds the roller shaft, and extends in the longitudinal direction, and wherein the casing has an elongated opening extending in the longitudinal direction; first end support supporting the first shaft end and positioning the first shaft end inside and relative to the casing; second end shaft support supporting the second shaft end and positioning the second shaft end inside and relative to the casing; first end wall closing the first end of the casing; second end wall closing the second end of the casing; power coupler at an end of the roller shaft for receiving power from a source to rotate the roller shaft.
[0005] Further aspects of the invention will become apparent upon reading the following detailed description and drawings which illustrate the invention and preferred embodiments of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
[0006] In the drawings, which illustrate embodiments of the invention:
[0007] [0007]FIG. 1 is a partial prospective section view along line 1 - 1 as shown in FIG. 2;
[0008] [0008]FIG. 2 is a partial sectional view along the vertical axis of an embodiment of the invention;
[0009] [0009]FIG. 3 is a partial sectional view along the vertical axis of another embodiment of the invention;
[0010] [0010]FIG. 4 is a partial, prospective, cut-away view of another embodiment of the invention;
[0011] [0011]FIG. 5 is a partial, prospective, cut-away view of another embodiment of the invention;
[0012] [0012]FIG. 6 is one preferred embodiment of the casing of the invention;
[0013] [0013]FIG. 7 is a partial cross-sectional view showing one way in which the invention may be installed;
[0014] [0014]FIG. 8 is a partial cross-sectional view showing another way in which the invention may be installed;
[0015] [0015]FIG. 9 is a prospective view showing some aspects of an embodiment of the invention;
[0016] [0016]FIG. 10 is a blow-out prospective view showing some aspects of a preferred embodiment of the invention;
[0017] [0017]FIG. 11 is a blow-out prospective view showing some aspects of a preferred embodiment of the invention; and
[0018] [0018]FIG. 12 is an end view of a preferred embodiment of the invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0019] A below-deck solar blanket roller assembly of the present invention is shown partially in FIGS. 1 and 2. The roller assembly 10 comprises a rotatable roller shaft 12 for rolling and unrolling a solar blanket 88 (as seen in FIG. 7). The solar blanket 88 is attached by suitable means, such as rivets, screws, glues, glue, touch fasteners or ties, to the roller shaft 12 . The roller shaft 12 has a first end 14 and a second end 16 and a longitudinal axis LA extending in a longitudinal direction LD.
[0020] The roller assembly 10 also includes a non-rotatable protective casing 18 having a first end 20 and a second end 22 .
[0021] The casing 18 is spaced radially from the roller shaft 12 . The casing 18 surrounds the roller shaft 12 . The casing 18 extends in the longitudinal direction LD. The casing 18 has an elongated opening 24 extending in the longitudinal direction LD. The solar blanket 88 passes through the opening 24 from the roller shaft 12 to the pool 64 (as seen in FIG. 7).
[0022] The roller assembly 10 also comprises a first end support 26 which supports the first shaft end 14 and which also positions the first shaft end 14 inside the casing 18 relative to the casing 18 . Preferably the first end support 26 supports the first end 14 through a bearing assembly 28 or other suitable device to permit easy rotation of the roller shaft 12 .
[0023] Similarly, there is a second end shaft support 30 supporting the second shaft end 16 and which positions the second shaft end 16 inside the casing 18 relative to the casing 18 . Once again, there is a bearing assembly 32 or other suitable device to permit easy rotation of the roller shaft 12 .
[0024] There is a first end wall 34 closing the first end 14 of the casing 18 .
[0025] Also, there is a second end wall 36 closing the second end 16 of the casing 18 .
[0026] In a preferred embodiment, the first end wall 34 sealingly closes the first end 20 of the casing 18 and the second end wall 36 sealingly closes the second end 22 of the casing. This is preferred in order to keep as much dirt and other debris as possible from entering the casing 18 after the casing 18 has been installed.
[0027] There is a power coupler 38 at an end of the roller shaft 12 for receiving power from a source to rotate the roller shaft 12 .
[0028] The source of power could be human energy. For example, there could be a manual crank positioned away from the casing. A human operator would turn the crank and the crank would be suitably coupled to the power coupler 38 such as through a chain and sprocket or through suitable gears.
[0029] Alternatively, the power source could be a suitable electric motor, such as a low voltage electrical motor 90 (as shown in FIG. 2). The electric motor 90 could be positioned within the casing 18 or outside the casing 18 . In either case, there would be suitable power linkage 92 from the electric motor 90 to the power coupler 38 .
[0030] The power coupler 38 is any suitable power coupler, including something as simple as a hole in the end of the roller shaft 12 to receive a similarly-shaped insert from the power linkage from the power source. Also, the power coupler 38 could include a sprocket, gear, or longitudinal extender.
[0031] The casing 18 has an inner peripheral wall 40 . In one embodiment of the invention, the first end support 26 comprises a first rigid support member 42 extending from a first position 44 on the inner peripheral wall 40 of the casing 18 to a second position 46 on the inner peripheral wall 40 of the casing 18 .
[0032] Similarly, the second end support 30 is comprised of a similar second rigid support member 48 extending from a third position on the inner peripheral wall 40 of the casing 18 to a fourth position on the inner peripheral wall 40 of the casing 18 .
[0033] Preferably, each of the rigid support members 42 and 48 is aligned in a plane parallel to a plane defined by the longitudinal axis LA and an axis orthogonal to the longitudinal axis, as for example as shown by the first rigid support member 42 in FIG. 1.
[0034] In a more preferred embodiment of the invention, each of the support members 42 and 48 is horizontal, such as the first rigid support member 42 as shown in FIG. 1.
[0035] In an alternative embodiment, the roller shaft 12 and the casing 18 are substantially the same as discussed above and shown in FIGS. 1 and 2, however, the first end support 126 as shown in FIG. 3 is comprised of a support member 142 which is aligned in a plane defined by two axes which are orthogonal to each other and also orthogonal to the longitudinal axis LA. For example, as shown in FIG. 3, the two axes which are orthogonal to each other are the vertical axis YA and the Z axis ZA which comes transversely out of the paper of FIG. 3.
[0036] In this embodiment, the second end support 130 similarly comprises a rigid support member 148 which is aligned in a plane defined by two axes which are orthogonal to each other and also orthogonal to the longitudinal axis.
[0037] Also, in order to have roller shaft 12 rotate most easily, each of the support members 142 and 148 support bearing assemblies 128 .
[0038] In another embodiment, as shown in FIG. 4, there is a lid 50 associated with the casing 18 . The lid 50 covers the elongated opening 24 in the casing 18 . The lid 50 is movable from a first position (as shown in FIG. 4) where the elongated opening 24 in the casing 18 is closed to a second position where the lid 50 is radially outward of the casing 18 where the elongated opening 24 in the casing 18 is open (as shown in FIG. 5).
[0039] As may be seen in FIG. 1, the opening 24 in the casing 18 is defined by first edge 52 and second edge 54 . As may be seen in FIG. 4, the lid 50 may be hinged to the casing 18 in the area adjacent to the first edge 52 .
[0040] Also, a blanket protector 56 may be hinged to the casing 18 in an area adjacent to the second edge 54 such that the blanket protector 56 rotatably moves from a first position the casing 18 to a second position radially outward from the casing 18 as shown in FIG. 5.
[0041] The blanket protector 56 protects the solar blanket 88 as the solar blanket 88 is either unwound from the roller shaft 12 or wound back up onto the roller shaft 12 .
[0042] The lid 50 is moved to the open position when the operator desires to either unroll the solar blanket 88 from the roller shaft 12 and place the solar blanket over the surface of the pool or, alternatively, when an operator wants to roll the solar blanket 88 back onto the roller shaft 12 . When the solar blanket is either entirely rolled onto the roller shaft 12 or when the solar blanket 88 is positioned over the pool surface, the operator will typically close the lid 50 so as to cover the elongated opening 24 , primarily for safety reasons but also for aesthetic reasons.
[0043] Preferably the lid 50 has a “V” shape in cross-section so that it wedges into the opening 24 and is at least partially supported by the first and second edges 52 and 54 of the opening 24 . Also, the lid 50 can be partially supported by lips 58 and 60 (as shown in FIG. 5).
[0044] In a preferred embodiment, the casing 18 is formed from plastic, corrugated pipe, primarily to provide strength and rigidity to the casing 18 , as shown if FIG. 4.
[0045] Alternatively, in another preferred embodiment, the casing is formed from galvanized metal. In this embodiment, the casing need not be circular in cross-section. For example, the casing 18 could have a generally hexagonal shape as shown in FIG. 6, or some other suitable cross-sectional shape.
[0046] In yet a further embodiment of the invention, the casing 18 can be formed from extruded plastic. In essence, the plastic is extruded into the desired shape of the casing 18 as shown generally in FIGS. 1 to 3 . In a further preferred embodiment, the casing 18 could be extruded to include the lips 58 and 60 which are on the edges 52 and 54 of the opening 24 (as best seen in FIG. 5).
[0047] In a pool 64 that is at least partially surrounded by a deck 62 , the roller assembly 10 is intended to be installed below the deck 62 . In a preferred embodiment, the casing 18 is oriented such that the opening 24 in the casing 18 is aligned with an opening 66 in the deck 62 . Preferably, the opening 66 in the deck 62 is spaced away from a portion of the deck 68 which is immediately adjacent to the pool 64 . Preferably the portion of the deck 68 immediately adjacent to the pool 64 is supported by the pool wall 70 . In a more preferred embodiment of the invention, the opening 66 in the deck is spaced between the portion of the deck 68 immediately adjacent to the pool 64 and a deck portion 72 distant from the pool 64 . Preferably the deck portion 72 distant from the pool 64 is supported by a deck support 74 .
[0048] In another embodiment of the invention, the casing 18 is oriented such that the opening 24 in the casing 18 is aligned with an opening 76 in the pool wall 70 , as shown in FIG. 8.
[0049] In a preferred embodiment of the invention, the casing is supported by a pair of casing supports 78 as shown in FIG. 9. Preferably the casing support 78 is comprised of a suitable block, concrete or brick structure underneath each of the first and second ends 20 , 22 of the casing 18 . For example, in FIG. 9, the casing support 78 comprises a vertical concrete support member 80 . Preferably, the vertical concrete support member 80 is formed by pouring concrete into a plastic tube or sonotube. Preferably, the vertical concrete support member 80 is supported by a suitable footing 82 .
[0050] The casing 18 is supported by a first casing support at the first end 20 of the casing 18 and by a second casing support at the second end 22 of the casing 18 .
[0051] Preferably, each casing support 78 has a casing leveller.
[0052] In one embodiment, the casing leveller, as shown in FIG. 9, comprises a relatively short length of pipe 84 which is moveable up and down on the vertical concrete support member 80 . The top portion 86 of the pipe 84 is shaped to receive the casing 18 . The pipe 84 can be moved up and down on the vertical concrete support member 80 to adjust the height of the particular end 20 , 22 of the casing 18 . Adjustable screws 86 are tightened and forced into the vertical concrete support member 80 to fix the pipe 80 and the casing 18 at the desired height.
[0053] It will be understood that, although various features of the invention have been described with respect to one or another of the embodiments of the invention, the various features and embodiments of the invention may be combined or used in conjunction with other features and embodiments of the invention as described and illustrated herein.
[0054] Although this disclosure has described and illustrated certain preferred embodiments of the invention, it is to be understood that the invention is not restricted to these particular embodiments. Rather, the invention includes all embodiments which are functional or mechanical equivalents of the specific embodiments and features that have been described and illustrated herein. | A below-deck solar blanket roller assembly is installed below the deck of a pool. The roller assembly includes a rotatable roller shaft for rolling and unrolling a solar blanket and a non-rotatable protective casing which surrounds the roller shaft. The roller assembly is intended to be installed below the deck of a pool. This invention at least partially overcomes some of the disadvantages of typical solar blanket rollers that are installed on the surface of the pool deck, such as inconvenience in moving the entire above-deck assembly away from and back to the pool area. The below-deck solar blanket roller assembly provides an aesthetically pleasing and safe alternative to solar blanket roller assemblies installed above the pool deck. | 4 |
CROSS REFERENCES TO RELATED APPLICATIONS
[0001] This application is a continuation of PCT/FI00/00115, filed Feb. 16, 2000, and claims priority on Finnish Application No. 990343, filed Feb. 18, 1999, the disclosures of both of which applications are incorporated by reference herein.
STATEMENTS AS TO RIGHTS TO INVENTIONS MADE UNDER FEDERALLY SPONSORED RESEARCH AND DEVELOPMENT
BACKGROUND OF THE INVENTION
[0002] As known in the prior art, in connection with the wet end fabrics of a paper machine, for example, in guiding, spreading and cleaning of a felt in a press section, a separate device is used for each purpose, at least one of each of them being arranged for said purpose in connection with each fabric. In the arrangements known in the state of the art, the devices used for these purposes are an automatic guide, a manual guide, a guide roll, a curved spreader roll, suction units and jets. Such separate devices cause extra costs, they take space and require support structures in connection with the frame structures of the machine.
[0003] One problem with the suction units used in connection with the separate devices known in the prior art has been that the width of the suction slot has not always been adjustable so that several suction units may have been needed for each felt.
[0004] One problem in connection with suction units has also been that the suction unit rubs against the felt so that the press section consumes more power.
[0005] In the arrangements known in the state of the art, in fast machines in particular, the felt has worn quickly, which has been partly due to the rubbing of the ceramic covers of felt suction units. Rolls and mechanical impurities also wear felt.
[0006] The spreader rolls in the arrangements known in the prior art have had a constant curvature, and thus it has not been possible to adjust their spreading effect.
SUMMARY OF THE INVENTION
[0007] An object of the invention is to provide a device in which the above-noted problems with the prior art devices are not encountered.
[0008] An object of the invention is also to provide a device which is of low cost.
[0009] One further non-indispensable object of the invention is also to disclose a device in which the width of the suction slot in the suction unit is adjustable.
[0010] One further non-indispensable object of the invention is also to disclose a device in which the curvature of the spreader roll can be adjusted.
[0011] In accordance with the invention, the device comprises device components that accomplish at least two of the following functions: guiding, spreading and/or cleaning of a fabric. An advantageous embodiment example of the invention comprises the above-mentioned functions, all in the same device.
[0012] The device according to the invention thus comprises in accordance with an advantageous embodiment an automatic guide, a guide roll, a curved spreader roll and a suction unit in a single device assembly. Jets may also be incorporated in the device assembly.
[0013] In accordance with an advantageous additional feature of the invention, instead of prior known ceramic ribs, suction ribs that can be bent, for example, plastic ribs or equivalent are used as suction ribs of the suction slot of the suction unit, which is possible because the fabric is supported by rollers in the device. The adjustment of plastic ribs for regulating the width of the suction slot is easy to carry out and, when needed, the suction width can be increased, for example, at the edges with respect to the centre because the plastic rib is easy to bend.
[0014] Advantageously, in accordance with an additional feature of the device according to the invention, the journalling of the rollers (the guide roll and the spreader roll are formed of rollers) is accomplished by means of bearings lubricated with circulating grease or circulating oil or by means of permanently lubricated bearings, and the device can be turned upside down by using a hydraulic motor or cylinder for the purpose of cleaning. Advantageously, the end seals of the suction slot in the suction unit of the device are accomplished, for example, by means of adjustable overlapping joints. The suction pipe system of the suction unit is laid from both the driving side and the tending side, thus achieving a good and uniform suction effect.
[0015] The functions of the curved spreader roll are provided by placing the rollers forming the spreader roll in a form which is suitably curved. In a press section, the deflections of tubular rolls can be compensated for, for example, by placing the rollers at the edges of the machine at different heights using, for example, spacer plates under the bearing housings.
[0016] In felt guidance, the manual guide of the prior art arrangements has been omitted and the automatic guide is most preferably accomplished as a mechanical guide comprising linear guides and a worm gear, whereby the problems of known devices are avoided. The automatic guide is provided with such a movement length that no separate manual guide is needed. The movement length is, for example, 140 mm. In connection with the device in accordance with the invention, as a measuring head is advantageously used a non-contacting sensor or a contacting measuring transducer, i.e. a felt and wire tracking device.
[0017] The invention provides substantial savings in costs as the space requirement and the complexity of the device assembly are reduced. When used on fast machines, the service life of the fabric increases if the wear of the felt loop constitutes the main reason for replacement of the felt. The other main reasons for replacement of the felt include, for example, hardening, clogging, contamination or scheduled shutdown.
[0018] Only one device according to the invention is needed for each fabric because the width of the suction slot of the suction unit part can be adjusted, which allows optimization to be accomplished for each individual felt.
[0019] The power consumption of the press is reduced because the suction unit is less rubbing and fewer rolls are used than in the prior art arrangements since separate guide rolls and spreader rolls are no longer needed as they have been formed of rollers in connection with the device.
[0020] Curvature, i.e the power of spreading, can be regulated, in which connection the spreading effect can be regulated, and automatic control is self retaining retaining owing to a trapezoid-thread screw used in accordance with an advantageous example. It is easy to add automation to the device according to the invention, for example, controls and their automation can be readily incorporated, which increases the means of affecting the felt loop, for example, the profiling of the moisture of the felt by adjusting the width of the suction slot.
[0021] In the following, the invention will be described in more detail with reference to the figures of the accompanying drawing, to the details of which the invention is, however, not by any means intended to be narrowly confined.
BRIEF DESCRIPTION OF THE DRAWINGS
[0022] [0022]FIG. 1 schematically depicts one advantageous embodiment of the device according to the invention when viewed from the end.
[0023] [0023]FIG. 2 schematically depicts the device illustrated in FIG. 1 when viewed in the longitudinal direction.
[0024] [0024]FIG. 3 depicts some possible applications of the device according to the invention for use in connection with press felts of a press section.
[0025] [0025]FIG. 4 schematically depicts one advantageous modification of the embodiment illustrated in FIGS. 1 and 2 when viewed from the end.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0026] The advantageous embodiment example of the invention shown in FIGS. 1 and 2 comprises a suction unit part 19 which comprises a suction chamber 16 connected to the driving and tending sides by means of suction pipes 11 (tending side) and 18 (driving side). An adjustable suction slot 15 is formed between bendable suction ribs, preferably plastic ribs 13 and 14 , a fabric F being passed to run over said suction slot 15 in a direction S. A spreader roll 30 which is adjustable in its curvature has been placed before the suction ribs 13 , 14 in the running direction of the fabric F, which spreader roll is formed of rollers 31 between which adjustable bearing housings 32 have been placed, said bearing housings enabling the set of rollers formed by the rollers 31 , i.e. the spreader roll 30 , to be made curved. A guide roll 40 made up of rollers 41 and bearing means 42 therebetween has been placed on the outlet side of the suction slot 15 . An automatic guide 20 comprises linear guides 22 and a worm gear 23 as well as a movement base 21 and advantageously a trapezoid-thread screw 24 . Doctor boxes of the device 10 have been denoted with the reference numeral 17 and end seals of the suction slot 15 with the reference numeral 12 . The end seals 12 may be, for example, adjustable seals based on an overlapping joint. The suction ribs 13 , 14 are adjustable in position and bendable for adjusting the suction slot 15 .
[0027] The device in accordance with the invention thus comprises according to the advantageous embodiment shown in FIGS. 1 and 2 an automatic guide 20 , a guide roll 40 , a curved spreader roll 30 and a suction unit 19 as a single device assembly. The adjustment of the suction unit part 19 and the suction ribs 13 , 14 in order to adjust the width of the suction slot 15 is easy to accomplish, for example, by increasing the suction width at the edges with respect to the centre because the suction ribs 13 , 14 can be bent to a desired position. Advantageously, the journalling arrangements of the rollers 41 , 31 in the guide roll 40 and in the spreader roll 30 have been accomplished by means of bearings lubricated with circulating grease or circulating oil or by means of permanently lubricated bearings. The rollers 31 , 41 can be placed at different heights at the edges of the machine by using, for example, spacer plates under the bearing housings. The device 10 can be turned upside down by using a hydraulic motor or cylinder (not shown) for the purpose of cleaning.
[0028] [0028]FIG. 3 shows a schematic application of a press section 50 in which devices 10 according to the invention have been placed in connection with fabrics F; 51 , 52 , 53 , 54 . The press section 50 illustrated in the figure comprises two press nips N 1 , N 2 formed between press rolls 55 , 56 and 57 , 58 , respectively. The guide rolls of the fabrics have been denoted with the reference numeral 59 and rolls which comprise a suction slot have been denoted with the reference numeral 61 . A roll 60 adjustable in position is situated at the beginning of the press section in connection with a suction roll 61 , a paper web being passed between said rolls from a former.
[0029] In the schematic modification of FIG. 4 of the embodiment shown in FIGS. 1 and 2, the position of the suction ribs 13 , 14 is advantageously curved with respect to the fabric. In that connection, the fabric does not run straight but drawn into a curve, in which connection its friction is lowest. In other respects, the illustration of FIG. 4 corresponds to the embodiment shown in FIGS. 1 and 2. In FIG. 4, the parts corresponding to those of FIGS. 1 and 2 have been denoted with the same reference numerals.
[0030] A felt and wire tracking device is advantageously used in connection with the device according to the invention, said device being based on an angle sensor and on a flap lying against the edge of the felt as well as on a measuring head, in which the flap of the measuring head lying against the edge of the felt remains in contact with the edge of the felt by means of a compression spring placed inside an oil-containing cylinder, the structure of the return mechanism of said spring resembling the structure of a conventional shock absorber. Oil or an equivalent medium flows through a piston from holes making the movement of the flap more stable, and the return force is adjustable. Two measuring heads are used for each fabric, and the signal is filtered. An angle sensor of strong construction is used as the angle sensor of the measuring head, which withstands the amounts required for longitudinal and radial load, and the measuring member constructed inside its transducer is a non-wearing capacitive transducer operating without a mechanical contact. A sensor can be used both in the measuring head and as a position sensor of the guide, in which connection the adapting of output and input impulses is easy.
[0031] Above, the invention has been described only with reference to one of its advantageous embodiment examples, to the details of which the invention is not intended by any means to be narrowly confined. Many variations and modifications are feasible within the scope of the inventive idea defined in the following claims. | A device ( 10 ) for use in connection with a fabric (F) in a former or a press section of a paper machine comprises sub-assemblies which accomplish at least two of the following functions: guiding, spreading and/or cleaning of the fabric (F). The device ( 10 ) has an automatic guide ( 20 ) and a guide roll ( 40 ) for guiding the fabric (F), a curved spreader roll ( 30 ) for spreading the fabric (F), and a suction unit 19 for cleaning the fabric (F). | 3 |
BACKGROUND
The storage capacities of data storage systems have grown enormously. For example, EMC Corporation's Symmetrix® data storage system can offer storage measured in Terabytes. To offer this storage, a Symmetrix® system pools a collection of physical disks (also referred to as “spindles”).
Each physical disk can respond to a limited number of I/O (Input/Output) operations (e.g., read and write requests) in a given time period. The number of I/O operations a physical disk can handle is often measured in IOPS (Input/Output operations per second). To respond to I/O requests quickly and conserve IOPS, many systems use a high-speed cache (pronounced “cash”). For example, a cache can store copies of data also stored on a physical disk. If the system can respond to a request using a copy of data stored in the cache instead of retrieving data from the physical disk, the system has both reduced response time and reduced the I/O burden of the physical disks.
A cache can also speed responses to write requests. For example, the Symmetrix® system can store write requests in a cache and defer storage of the information to a physical disk until later. Thus, a host requesting the write operation receives fast confirmation of the write operation from the storage system even though the write operation has not yet completed.
SUMMARY
In general, in one aspect, the description includes a method of responding to storage access requests. The method includes defining at least one write area and at least one read-only area, receiving a write request specifying a first address that resides within the at least one read-only area, determining a second address in the write address area, and storing data associating the first address with the second address.
Embodiments may include one or more of the following features. The method may further include storing information included in the write request at the second address. Determining the second address may include determining the next sequential address of a write area. The method may further include receiving a read request specifying the first address, accessing the data associating the first address and the second address, and requesting information stored at the second address. The method may further include redefining the write area and read area to form at least one new write area and at least one new read area where at least a portion of the new read-only area occupies an area previously occupied by the write area. The method may further include defining a third area for storing a copy of at least one of the read-only areas, copying data stored in at least one of the read-only areas into the third area, and collecting free blocks of the third area.
In general, in another aspect, the description includes a computer program product, disposed on a computer readable medium, for responding to storage access requests. The computer program includes instructions for causing a processor to define at least one write area and at least one read-only area, receive a write request specifying a first address that resides within the at least one read-only area, determine a second address in the write address area, and store data associating the first address with the second address.
In general, in another aspect, the description includes a method of managing storage. The method includes defining a read-only storage area, a write storage area, and a first garbage storage area. The method also includes repeatedly redirecting write requests for an address within the read-only storage area to the write area, collecting free space in the garbage storage area, and defining a new read-only storage area, a new write storage area, and a new garbage storage area such that the new read-only area includes the previously defined write area and the new write area includes collected free space in the new garbage storage area.
Embodiments may include one or more of the following features. The method may further include copying data stored in the new read-only storage area to the new garbage storage area. The storage areas may be physical storage areas. The write requests may specify a physical address.
In general, in another aspect, the description includes a system for handling I/O (Input/Output) requests. The system includes a collection of storage disks and a block table associating addresses specified by the I/O requests with addresses of the storage disk. The block table also defines at least one read-only area of the storage disks, at least one write area of the storage disks, and at least one third area of the storage disks. The system also includes instructions for causing a processor to process a read request by accessing the block table to determine the storage disk address associated with the-address specified by the request. The system also includes-instructions for causing a processor to process a write request that specifies a storage disk address corresponding to the at least one read-only area of the storage disks by determining a next location in the at least one write area and storing information in the block table that associates the location in the at least one write area with the storage disk address specified by the write request.
Advantages will become apparent in view of the following description, including the figures and the claims.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a diagram of a data storage system.
FIGS. 2-5 are diagrams illustrating data storage using read-only and write areas.
FIG. 6 is a diagram illustrating free block collection.
FIG. 7 is a diagram illustrating redefinition of storage areas.
FIGS. 8-14 are diagrams illustrating operation of a data storage system.
FIG. 15 is a flow-chart of a process for handling I/O requests.
DETAILED DESCRIPTION
Data storage systems often handle a very large number of I/O requests. For example, FIG. 1 illustrates a Symmetrix® data storage system 104 that handles I/O requests received from multiple hosts 100 a - 100 n . As shown, the system 104 includes a cache 106 to speed host 100 a - 100 n access to data stored by collections of physical disks 110 a - 110 n . The system 104 also includes front-end processors 102 a - 102 n that process I/O requests received from the host computers 100 a - 100 n . For example, for a read request, the front-end processors 102 a - 102 n can determine whether the cache 106 currently holds a requested data block. If so, the front-end processors 102 a - 102 n can quickly satisfy the host computer's 100 a - 100 n request using the cached block. If not, the front-end processor 102 a - 102 n can ask a back-end processor 108 a - 108 n to load the requested block into the cache 106 . Thus, a read request that the cache 106 cannot satisfy results in a read I/O operation. For a write request, the front-end processors 102 a - 102 n can store the write data in the cache for subsequent writing to the physical disks 110 a - 110 n by the back-end processors 108 a - 108 n.
Described herein are a variety of techniques that can both enable a storage system, such as the Symmetrix® system, to devote greater resources to responding to read I/O requests and reduce the I/O burden of write requests. Generally speaking, these techniques include the definition of separate read-only and write storage areas and the use of “redirection” to route write requests away from the read-only areas. Freed, at least in part, from the duty of handling write requests, a physical disk storing a read-only area can devote more resources to read requests. This can, in turn, effectively increase the I/O speed of a storage system without requiring alteration or addition of physical storage.
To illustrate redirection, FIGS. 2-5 depict a partitioning of physical storage 132 into read-only 128 and write 130 areas. For example, a first set of spindles may be reserved for the read-only area 128 while a second set of spindles may be reserved for the write area 130 .
As shown, the read-only area 128 includes two blocks having physical block addresses of “1” 128 a and “2” 128 b , respectively. Similarly, the write area 130 includes two blocks having physical block addresses of “3” 130 a and “4” 130 b , respectively. It should be noted that, for the purposes of illustration, FIGS. 2-5 present a greatly simplified data storage environment. That is, instead of a physical storage 132 area totaling four blocks 128 a , 128 b , 130 a , 130 b , physical storage 132 may feature, for example, 256 TB (Terabytes) of memory divided into 4K (Kilobyte) blocks (i.e., 2 36 blocks).
As shown in FIG. 2, an I/O system 126 receives I/O requests. For example, the I/O system 126 may receive requests that access to a cache did not satisfy. For instance, as shown, the I/O system 126 has received a read request 120 for a block stored at physical address “1”. Instead of issuing a request for block “1” as specified by the request 120 , the I/O system 126 accesses an I/O block table 124 that correlates the requested address 125 a with the actual physical storage 132 block address 127 a of the requested block. In the case shown in FIG. 2, the table 124 indicates that the requested block 125 a is stored at the first block 128 a of physical storage 132 . The I/O system 126 can then issue a request to physical storage 132 for the data (“ali”) stored at block “1” 128 a.
In the sequence of FIG. 2, translating the requested block address 125 a to the physical storage 132 block address 127 a had no apparent affect (i.e., requested block “1” was coincidentally stored at physical block “1” 128 a ). However, introducing this redirection mechanism can enable the I/O system 126 to direct write requests away from the read-only area 128 . For example, in FIG. 3, the I/O system 126 receives a request 134 to write data (“beth”) at block address “2”. Address “2” 128 b of physical storage 132 , however, currently falls within the address space 128 designated as read-only. Thus, the I/O system 126 determines a physical address of the next free block 130 a in the write area 130 for storing the data. As shown, the I/O system 126 updates the I/O block table 124 to associate physical storage block address “3” 127 b with the requested address, “2” 125 b , and instructs 136 physical storage 132 to store the data in physical storage block “3” 130 a.
The I/O system 126 can implement such redirection “behind-the-scenes.” For example, a host may have no idea that the data specified for storage at physical block address “2” 128 b is actually physically stored at block “3” 130 a . For instance, as shown in FIG. 4, when the I/O system 126 receives a read request 138 for the data block stored at address “2”, the I/O system 126 can use the I/O block table 124 to determine the physical location 130 a of the block. Thus, narrating FIGS. 3 and 4 from a host's view-point: the host requested storage of “beth” at physical block “2” (FIG. 3) and retrieved “beth” by specifying a read of physical block “2” (FIG. 4 ), exactly as expected by the host.
It should be noted that a write request need not specify insertion of new data, but may instead modify previously stored data. As shown in FIG. 5, the I/O system 126 can, again, direct such write requests away from the read-only area 128 . That is, instead of modifying the data stored at the specified address, the I/O system 126 can determine the address of the next free block 130 b in the write area 130 to store the modified data and update the I/O block table 124 accordingly. For example, a request 144 to change the value of block “1” from “ali” to “carl” causes the system 126 to store “carl” in physical block “4” 130 b and change the physical address 127 a associated with address “1” 125 a from “1” to “4” 127 a.
In addition to storage redirection, FIGS. 2-5 also illustrates sequential writing into the write area 130 . That is, for each successive write operation, the system 126 uses the next sequential write area 130 location. Since physical devices generally store nearby blocks more quickly than blocks found at scattered locations, sequential access facilitates fast storage of writes.
Eventually, a write area 130 may run out of free blocks (e.g., blocks that do not store current data). However, as shown in FIG. 6, a system can create room for more sequential writes by collecting free blocks of an area 154 together, updating an I/O block table to reflect block rearrangement, and defining a new write area for the collected free blocks.
In greater detail, FIG. 6 depicts an I/O block table 150 , 152 and physical storage area 154 , 156 before and after aggregation-of free blocks. As shown, an area 154 initially features two free blocks, “2” and “4” interspersed between two used blocks, “1” and “3”. After moving used block “3” 154 c to physical address block “2” 156 b and changing the I/O block table entry for block “3” from “3” 150 b to “2” 152 b physical storage 156 features a sequential two block area of free blocks, namely, blocks “3” and “4”. The system may define this new collection of free blocks as a new write area and continue handling write operations sequentially. Again, though the system moves blocks around, the corresponding changes to the I/O block table 150 , 152 enables an I/O system to maintain access to previously stored data.
Instead of operating on an active area (e.g., a read-only area) to collect free blocks, a system may create new write space by operating on a copy of active data. This permits the system to coalesce free blocks without interfering with on-going I/O operations. For example, a background process may handle block rearrangement and revision of I/O block table entries (e.g., entries for addresses “5” and “7”) representing the rearrangement.
FIG. 7 illustrates such free block collection using a “garbage area” copy of an active area. The garbage area may be assigned to different spindles than the active area to reduce impact on requested I/O operations.
In greater detail, FIG. 7 depicts physical storage 162 a partitioned into an active area and a garbage area. As shown, mirroring 164 a the garbage area copies the active area blocks into the garbage area and adds I/O block table 160 b entries for the garbage area. A system can then collect 164 b free blocks of the garbage area. Next, the system can redefine 164 c the physical blocks that constitute the active and garbage areas. For example, blocks “5” to “8” of physical storage 162 d which were previously allocated for the garbage area are now allocated for the active area. Similarly, blocks “1” to “4” of physical storage 162 which were previously allocated for the active area are now allocated for the garbage area.
As shown, to reflect the area redefinitions, a system has updated the I/O block table 160 d . If not updated, addresses “1” to “4” of the table 160 d would refer to physical blocks allocated for the new garbage area instead of the new active area. Thus, the system updates the physical addresses of the table 160 d to preserve the links to the appropriate areas. That is, after updating, addresses “1” to “4” in the block table 160 d are associated with physical addresses in the new active area and addresses “5” to “8” are associated with physical addresses in the new garbage area. Again, this ensures that while an I/O system may move physically stored blocks around, the I/O block table 160 , nevertheless, maintains the external presentation of stored data expected by hosts.
FIGS. 2-7 illustrated techniques that included the use of an I/O block table to direct write requests away from a read-only area, the collection of free blocks to dynamically form a new write area, the use of a garbage area to collect free blocks in the background, and the redefinition of areas to use the newly collected free blocks for sequential writing. FIGS. 8-14 illustrate operation of a system that combines these techniques.
In greater detail, each of FIGS. 8-14 show physical storage 202 and an I/O block table 200 accessed by an I/O system 204 . The table 200 includes a designation of the usage 210 of a physical address as “read-only”, “write”, or “garbage collection”. The table 200 also includes a mapping of an address 208 to a physical block 212 . To reduce the space occupied by the table 200 , the address 208 may not be physically stored, but may instead represent an index into the table 200 .
FIG. 8 depicts the state of an on-going system. In this system, the I/O block table 200 usage 210 data defines physical blocks “1” to “4” 214 a - 214 d as a read-only area, physical blocks “5” and “6” 214 e - 214 f as a write area, and physical blocks “7” to “10” 214 g - 214 j as a garbage collection area. Since the I/O block table 200 defines physical storage usage 210 , partitioning physical storage can occur without communicating the partitioning scheme to the physical storage device(s). That is, the intelligence of the system may reside in the I/O block table 200 and associated software 204 (e.g., instructions executed by a back-end processor) rather than requiring modification of a host or physical storage device. The system may, however, use a priori knowledge of physical storage to ensure segregation of the different usage areas on different spindles through-out system operation.
As shown in FIG. 9, the I/O system 204 receives a request 216 to insert “carl” at address “2”. As shown in the I/O block table 200 , address “2” 208 b corresponds to a physical address designated 210 for read-only use. Thus, the I/O system 204 determines the next sequential block 214 e in the designated write area for storing the data, for example, by incrementing a write area pointer. As shown, the I/O system 204 also updates the I/O block table 200 to designate physical block “5” 212 b as the physical storage block address for address “2” 208 b.
As shown in FIG. 10, the I/O system 204 next receives a request 218 to modify the data of address “3” from “beth” to “dawn”. Again, the I/O block table 200 indicates address “3” 208 c currently corresponds to a physical address designated for read-only use. Thus, the I/O system 204 , determines the next sequential block in the write area 214 f and updates the I/O block table 200 accordingly.
As shown in FIG. 11, while the I/O system 204 handles read and write requests, the I/O system 204 or another processor may collect free blocks in the garbage area together and correspondingly update the I/O block table 200 . For example, comparing FIG. 10 to FIG. 11, a garbage collection process has moved the storage location of “beth” from physical block address “9” 214 i to physical block address “8” 214 h and updated the I/O block table 200 accordingly.
As shown in FIG. 12, at some configurable time (e.g., when the current write area nears full), the I/O system 204 can redefine the read-only, write, and garbage areas. As shown, the I/O system 204 changes the designated usage 210 of the I/O block table 200 to define the collected free blocks, physical blocks “9”. and “10” 214 i - 214 j , as the new write area; define the old read-only area, blocks “1” to “4” 214 a - 214 d , as the new garbage area; and define a new read-only area from the old write area and the “compressed” old garbage collection area, blocks “5” to “8” 214 e - 214 h . As shown in FIG. 13, the system 204 updates the I/O block table 200 so that the addresses “1” to “4” 208 a - 208 d map to the new read-only area blocks 214 e - 214 h . It should be noted that while the I/O block table 200 changes the use 210 designated for a particular physical address 208 , the I/O block table 200 maintains the external view of data. For example, host requests for addresses “1” to “4” 208 a - 208 d still resolve to physical address 212 a - 212 d in the newly defined read-only area though the location of the read-only area has changed.
It should be noted that while FIGS. 12 and 13 are shown as discrete actions, a system may implement the area redefinition (FIG. 12) and I/O table update (FIG. 13) as a single atomic operation. For example, a substitute I/O block table may be built and swapped-in after completion.
As shown in FIG. 14, at some point, the system 204 then mirrors the new read-only area by copying blocks “5” to “8” 214 e - 214 h into the new garbage area, blocks “1” to “4” 214 a - 214 d , and updates the I/O block table 200 accordingly. The process illustrated in FIGS. 8-14 then repeats anew.
To summarize an example of I/O system operation, FIG. 15 illustrates a process 300 for handling I/O requests. As shown, the process 300 designates 302 read-only, write, and garbage areas. The process 300 can direct 306 write requests away from the read-only area, for example, using the I/O block table described above. During this time, the process 300 can mirror 304 the read-only area in the garbage area and coalesce 308 free garbage area blocks. The process 300 then defines 310 new read-only, write, and garbage areas, and repeats. Thus, the process 300 continually, and in real-time, creates collections of free blocks and uses them for sequential write operations. Hence, the process 300 can replace scattered random writes with efficient sequential ones. As described above, the process 300 can also increase the amount of resources dedicated to processing read requests through the use of storage indirection.
While described against a backdrop of the Symmetrix® data storage system, the techniques described herein are not limited to a particular hardware or software configuration and may find applicability in a wide variety of computing or processing environments. The techniques may be implemented in hardware or software, or a combination of the two. For example, the techniques may be implemented in ASICs. The techniques may also be implemented in computer programs executing on programmable computers that each include a processor, a storage medium readable by the processor (including volatile and non-volatile memory and/or storage elements), at least one input device, and one or more output devices.
Each program is preferably implemented in high level procedural or object oriented programming language to communicate with a computer system. However, the programs can be implemented in assembly or machine language, if desired. In any case the language may be compiled or interpreted language.
Each such computer program is preferably stored on a storage medium or device (e.g., CD-ROM, hard disk, or magnetic disk) that is readable by a general or special purpose programmable computer for configuring and operating the computer when the storage medium or device is read by the computer to perform the procedures described herein. The system may also be considered to be implemented as a computer-readable storage medium, configured with a computer program, where the storage medium so configured causes a computer to operate in a specific and predefined manner.
Other embodiments are within the scope of the following claims. | In general, in one aspect, the description includes a method of responding to storage access requests. The method includes defining at least one write area and at least one read-only area, receiving a write request specifying a first address that resides within the at least one read-only area, determining a second address in the write address area, and storing data associating the first address with the second address. | 8 |
FIELD OF THE INVENTION
[0001] This invention relates in general to cementing a casing string within a wellbore, and in particular to a pump down cement retaining device that prevents backflow of cement.
BACKGROUND OF THE INVENTION
[0002] Most oil and gas wells are drilled with a drill string comprised of drill pipe. After reaching a certain depth, the drill string is removed and casing is lowered into the wellbore. A cement valve, is normally attached to the lower end of the casing. The cement valve allows cement to be pumped down through the casing and up the annulus surrounding the casing, and prevents backflow of cement from the annulus back into the casing. Another type of casing string, referred to as a liner, may be installed in a similar manner. A casing string extends all the way back to the upper end of the well, while a liner string is hung off at the lower end of a preceding string of casing.
[0003] In another drilling technique, the casing is used as part or all of the drill string. The bit may be attached to the lower end of the casing string permanently, in which case it is cemented in place. Alternatively, it may be retrieved after reaching desired depth, such as by using a wireline, drill pipe, or pumping the bit assembly back up the casing. While drilling, the casing string may be rotated by a gripping mechanism and a top drive of the drilling rig. With liner drilling, the liner string serves as the lower end of the drill string, and a string of drill pipe is attached to upper end of the liner string.
[0004] In casing and liner drilling, if the bottom hole assembly, which includes a drill bit and optionally measuring instruments and steering devices, is to be retrieved before cementing, the operator will install a cement valve at the lower end of the liner after retrieval of the bottom hole assembly. The cement valve may be lowered into place on a wire line or a string of drill pipe and locked to a profile at the lower end depth of the liner string. Also, it is has been proposed to pump the cement valve down the casing, rather than convey it on a wire line. The cement valve may have a flapper valve to prevent back flow of cement. It may also have a frangible barrier to allow the cement valve to be pumped down the casing string. Once in place, increased fluid pressure causes the barrier to break and the fluid to flow out the lower end of the cement valve.
[0005] It has also been proposed to pump a receptacle down the casing string and latch it into a profile at the lower end prior to cementing. The receptacle has a passage that allows the downward flow of cement, but does not have a valve to prevent backflow. At the conclusion of cementing, a wiper plug or prong is pumped down into engagement with the receptacle. The prong stabs into the upper end of the receptacle to form a seal and retain the plug to prevent backflow of cement.
[0006] After the cement is cured, if the operator intends to drill the well deeper, the drill string must drill through the receptacle and wiper plug. It is thus desirable to make the receptacle and wiper plug of easily drillable materials. These materials must meet the requested specifications of the tools.
SUMMARY OF INVENTION
[0007] The method of this invention utilizes a receptacle that is positioned at the lower end of the casing string. A wiper plug is pumped down the string of casing following the pumping of cement. The wiper plug has a prong on its end with a seal that seals within a lower portion of the receptacle. The positioning of the seal places the receptacle under a compressive force when a pressure differential exists due to uncured cement in the annulus. Since the force is compressive, many of the components of the receptacle can be made of more easily drillable materials, such as plastic and resin composites, than in the prior art design. The prior art design had to accommodate at least some tensile forces.
[0008] In the preferred embodiment, the lower end of the prong is substantially flush with a lower end of the axial passage through the receptacle once locked in place. Preferably, the seal is also located at the lower end of the axial passage. The latching members of the prong and receptacle may comprise a ratchet sleeve and a grooved profile
BRIEF DESCRIPTION OF THE DRAWINGS
[0009] FIG. 1 is a sectional view of a receptacle installed in a profile at the lower end of a string of casing in accordance with this invention.
[0010] FIG. 2 is a sectional view of the receptacle of FIG. 1 , with the burst disk broken to allow fluid to be pumped through the axial passage.
[0011] FIG. 3 is a sectional view of the receptacle of FIG. 1 , showing a wiper plug and prong being pumped down the string of casing.
[0012] FIG. 4 is a sectional view of the wiper plug and receptacle of FIG. 3 , but showing the prong fully engaged with the receptacle.
[0013] FIG. 5 is a sectional view of the wiper plug, prong and receptacle of FIG. 4 , but showing fluid pressure acting upward on the lower end of the receptacle.
[0014] FIG. 6 is an enlarged sectional view of the wiper plug and prong of FIG. 3 .
[0015] FIG. 7 is a further enlarged sectional view of a lower portion of the wiper plug prong landed within the receptacle as shown in FIGS. 4 and 5 .
[0016] FIG. 8 is a sectional view of an alternate embodiment of a wiper plug and prong.
[0017] FIG. 9 is a sectional view of an alternate embodiment of a receptacle, and showing the wiper plug and prong of FIG. 8 installed.
DETAILED DESCRIPTION OF INVENTION
[0018] Referring to FIG. 1 , a string of casing 11 comprises tubular members secured together by threads for installation in a wellbore. The term “casing” is used broadly herein to include also a liner string, which is normally constructed the same as casing but does not extend fully to the surface, rather its upper end is hung off near the lower end of the preceding string of casing.
[0019] A lower or profile sub 13 is attached to the lower end and forms part of the string of casing 11 . Profile sub 13 has number of internal grooves that in this embodiment were used previously to secure a bottom hole assembly (not shown) for drilling. Profile sub 13 also has an annular recess 15 located therein that has a larger inner diameter than the inner diameter of the remaining portion of the string of casing 11 . Recess 15 is defined by an upper shoulder 17 and a lower shoulder 19 .
[0020] A cement plug receptacle 21 is shown latched into profile sub 13 . Cement plug receptacle 21 has a body 23 with an axial passage 25 extending through it. Body 23 has at least one and optionally a plurality of circumferential grooves 27 on its exterior. In this embodiment, grooves 27 are configured in a triangular fashion, resulting in a downward-facing conical flank 29 intersecting an upward-facing conical flank 31 . When viewed in cross-section, flanks 29 of grooves 27 are parallel to each other and flanks 31 are parallel to each other.
[0021] An outward-biased collar 33 surrounds body 23 at grooves 27 . Collar 33 is of a resilient material and is split so as to radially expand and contract. Collar 33 has at least one and optionally a plurality of internal grooves 35 for mating with grooves 27 of body 23 . The resiliency of collar 35 causes it to spring outward from grooves 27 when it reaches profile sub recess 15 . As receptacle 21 moves down casing 11 , prior to reaching recess 15 , the outer diameter of collar 33 will slidingly engage the inner diameter of casing 11 . Anti-rotation keys 37 , one at the upper end and one at the lower end of body 23 , engage collar 33 to prevent collar 33 from rotating relatively to body 23 . Grooves 35 have same configuration as grooves 27 , but body 23 is capable of axial movement from a lower position relative to collar 23 , shown in FIG. 4 to an upper position, shown in FIG. 5 . In the lower position, downward-facing flanks 29 of body grooves 27 are engagement with collar grooves 35 but upward-facing flanks 31 are not in engagement with collar grooves 35 . In the upper position of FIG. 5 , upward-facing flanks 31 are engagement with grooves 35 , but downward-facing flanks 29 are not in engagement with grooves 35 .
[0022] Referring still to FIG. 1 , body 23 has a lower body extension 39 that has a threaded neck 41 that secures it to the lower end of body 23 . Lower body extension 39 could optionally be integrally formed with body 23 . Axial passage 25 extends through lower body extension 39 . A latch member sleeve 43 with internal grooves is mounted within lower body extension 39 .
[0023] A lower seal 45 is attached to the lower end of lower body extension 39 by a threaded neck 47 . Lower seal 45 is illustrated as a cup seal, having a downward-facing concave interior; but it could be other types. Pressure acting on the lower side of lower seal 45 pushes seal 45 outward and upward into sealing engagement with profile sub 13 . A cylindrical seal member 48 is preferably located in the portion of axial passage 25 that extends through lower seal 45 .
[0024] An upper seal 49 is mounted to the upper end of body 23 by a threaded neck 51 in this example. Upper seal 49 may have the same general shape as lower seal 45 . Axial passage 25 extends through upper seal 49 but it is initially closed by a frangible barrier, which comprises a burst disk 53 in this example. Burst disk 53 closes axial passage 25 until the differential pressure acting on it exceeds a selected level, at which time it breaks or ruptures to allow flow through axial passage 25 . Burst disk 53 is secured to upper seal 49 by a shear cylinder retainer 55 . FIG. 1 shows burst disk 53 as initially installed and FIG. 2 shows burst disk 53 after being ruptured. Rather than the barrier device being a rigid frangible member, burst disk 53 could be a flexible elastomeric member or diaphragm that ruptures, or other types of devices.
[0025] FIG. 3 shows a wiper plug 57 being pumped down following the dispensing of cement. Wiper plug 57 has flexible ribs 59 on its outer side that seal against the inner diameter of casing 11 as it moves downward. A prong 61 is mounted to the lower end of wiper plug 57 and protrudes downward. Prong 61 comprises a rod located on the axis of wiper plug 57 . A plurality of transverse ports 67 optionally may be formed along its length. A nose 69 is attached to the lower end of prong 61 . Referring to FIG. 7 , nose 69 has one or more seal 71 that extends around it. Seals 71 seal against seal sleeve 48 located within lower seal 45 . A latch member comprising a ratchet sleeve 73 is mounted just above nose 69 . Ratchet sleeve 73 is a split cylindrical sleeve that is biased outward due to its internal resiliency. Ratchet sleeve 73 has grooves 75 on its exterior that will mate with the grooves in latch sleeve 43 . Grooves 75 and the mating grooves in latch sleeve 43 are configured to allow downward movement of prong 61 but not upward movement. During downward movement, the saw-tooth shape of grooves 75 in ratchet sleeve 73 cause ratchet sleeve 73 to retract and expand.
[0026] An annular retainer 77 located below ratchet sleeve 73 on the upper end of nose 69 has a tapered surface 79 on its upper end that faces upward and outward for urging ratchet sleeve 73 outward into tighter engagement due to internal pressure acting against nose seals 71 .
[0027] Preferably, most, if not all the components of cement plug receptacle 21 and wiper plug 57 are constructed of easily drillable materials to allow the operator to readily drill out the assembly after the cementing operation is over and the cement is secured. These materials may include composite materials, such as resin reinforced fiber as well as plastic materials. They may also include metallic materials such as aluminium.
[0028] In operation, after drilling to a desired depth and retrieving the bottom hole assembly (not shown), the operator places cement plug receptacle 21 into the upper end of the string of casing 11 and applies fluid pressure to casing 11 to pump it downward, typically with water. When cement plug receptacle 21 reaches recess 15 , the outward-biased collar 33 springs outward and secures cement plug receptacle 21 to profile sub 13 , as shown in FIG. 1 . Once in engagement, downward movement is prevented by upward-facing shoulder 19 and upward movement is prevented by downward-facing shoulder 17 .
[0029] Continued fluid pressure after cement plug receptacle 21 has landed shears burst disk 53 , as shown in FIG. 2 . Once burst disk 53 ruptures, the operator may pump cement through casing 11 , which flows through axial passage 25 and up the annulus surrounding casing 11 . When the desired quantity of cement has been dispensed, the operator places wiper plug 57 in casing string 11 , as shown in FIG. 3 , and pumps wiper plug 57 downward, normally with water. Wiper plug 57 pushes the cement in casing string 11 downward through axial passage 25 . Eventually, prong 61 will stab into axial passage 25 , as shown in FIG. 4 , and wiper plug 57 will land on retainer 55 . At this point, the tip of wiper plug nose 69 will be located substantially flush with the lower end of axial passage 25 . Seals 71 on nose 69 will be sealing engagement with seal sleeve 48 ( FIG. 7 ). Ratchet sleeve 73 will be in locking engagement with latch sleeve 43 . Downward-facing flanks 29 on body 23 will be in engagement with grooves 35 in collar 33 . Most, if not all, of ribs 59 of wiper plug 57 will be located above receptacle 21 and do not perform any latching function or any sealing function against upward acting pressure.
[0030] The operator may then release the fluid pressure from above wiper plug 57 . The weight of the cement in the casing annulus tends to cause it to flow back upward into casing string 11 . Wiper plug 57 and body 23 will initially move upward slightly in unison due to the differential pressure force as shown in FIG. 5 . This upward movement will stop once upward-facing flanks 31 on body 23 engage grooves 35 in collar 33 , as shown in FIG. 5 . The load path due to the pressure of the cement in the annulus passes through lower seal 45 , lower body extension 39 and body 23 into collar 33 , which transfers the load to profile sub 13 through upper shoulder 17 . The load path also passes from nose 69 through latch sleeve 43 into lower body extension 39 . Lower body extension 39 , body 23 , nose 69 and collar 33 will be in compression. No components of receptacle 21 or wiper plug 57 will be in tension as a result of the upward acting pressure.
[0031] After the cement has cured, the operator may run a new drill string, which could comprise drill pipe or a smaller diameter string of casing. A drill bit on the lower end will drill out cement plug receptacle 21 , leaving only profile sub 13 .
[0032] An alternate embodiment is shown in FIGS. 8 and 9 . Referring to FIG. 8 , prong 81 differs from the first embodiment in that is does not have holes such as ports 67 ( FIG. 2 ) extending through it perpendicular to its axis. Also, its internal cavity 82 is deeper than the internal cavity of prong 61 ( FIG. 6 ). Nose 83 is longer than nose 69 of the first embodiment; however, seals 85 are positioned about the same distance from the lower end as seals 71 on nose 69 of the first embodiment. Nose 83 may have an axially extending internal cavity 84 , as shown. A split ratchet ring 87 is attached near the lower end of prong 81 as in the first embodiment. Wiper plug 89 on the upper end of prong 81 has seal ribs 91 that protrude radially less distance from the body of wiper plug 89 than seal ribs 59 of the first embodiment.
[0033] Referring to FIG. 9 , receptacle 93 is shown anchored in a profile sub 95 that may the same as lower sub 13 of the first embodiment. Receptacle has a lower cup seal 97 that differs from lower seal 45 ( FIG. 1 ) in that it is carried on a tubular cup mandrel 99 of a more rigid material than the material of seal 97 . An annular load ring 101 encircles cup mandrel 99 for transmitting upward compressive force from lower seal 97 to a tubular extension member 103 . The first embodiment does not have a load ring. The upper end of cup mandrel 99 is secured to extension member 103 , and the lower end of cup mandrel 99 extends below load ring 101 into lower seal 97 . Ratchet or internally grooved sleeve 105 is mounted within extension member 103 for engagement with ratchet ring 87 on prong 81 as in the first embodiment.
[0034] Body 107 is attached to the upper end of extension member 103 and may be constructed the same as body 23 of the first embodiment. A collar 109 encircles body 107 and springs outward into a recess 111 of profile sub 95 as in the first embodiment. An upper cup seal 113 similar to upper seal 49 ( FIG. 1 ) is mounted on top of body 107 . A seat 115 containing a burst disc 117 is mounted within upper seal 113 . The operation of the embodiment of FIGS. 8 and 9 is the same as the operation of the first embodiment.
[0035] While the invention has been shown in only two of its forms, it should be apparent to those skilled in the art that is not so limited, but is susceptible to various changes without departing from the scope of the invention. | A wall casing cement plug assembly includes a receptacle with an axial passage. The receptacle is pumped to a lower end of the casing string and locked in place. The receptacle has a casing seal that engages the string of casing and a retainer mechanism on its exterior that engages a profile in the string of casing. Cement is pumped through the receptacle by rupturing a blocking device in the axial passage of the receptacle. A wiper plug is pumped down the string casing. The wiper plug has a prong on its lower end that stabs into the axial passage of the receptacle. A latch located in the lower portion of the receptacle locks the wiper plug to the body. | 4 |
CROSS-REFERENCE TO RELATED APPLICATIONS
This application claims the benefit of U.S. Provisional Application No. 60/567,031 filed Apr. 30, 2004, the disclosure of which is hereby incorporated by reference in its entirety.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates generally to threaded API casing connections, but more specifically to the couplings for API Buttress threaded casing to be used as a combination drill string and casing string—i.e., Drilling With Casing (DWC).
2. Description of the Related Art
Presently the conventional method for drilling oil and gas wells is to use drill pipe specifically designed for and dedicated to drilling the well bore. Upon drilling a well to completion, the drill pipe is pulled from the well and transferred to the next location for drilling another well. The drill pipe is thus used until it is worn out. The open hole left by the drill pipe is sealed off by running a string of casing pipes to the bottom of the hole and cementing the casing string in place.
In contrast to the above procedure, it is the purpose of new technology to eliminate the use of the above-described drill pipe and instead use the casing string for both drilling the well and casing off the open hole. The procedure is commonly referred to as “Drilling With Casing” (DWC). This procedure has been tried in various parts of the world but with limited success. However DWC offers so much potential for reducing drilling costs that interest remains high throughout the industry and many new projects are aimed at advancing the technology.
In conventional casing usage, the casing and its connections are subjected only to static loads comprising tension, torsion, compression, bending, pressure and any combination thereof. In DWC usage, the casing and connections are not only subject to all of the above static loads, but also to dynamic loads due to rotating the casing at 100 to 150 RPM while drilling the well bore. As the casing rotates and advances down the well bore, the casing string and particularly the connections, which have a larger outside diameter than the casing, are subject to cyclic fatigue loads, severe abrasion wear and impact loading, then finally to all the static loads mentioned above after the casing is set and cemented in the well.
This invention is directed at one of the primary problems associated with DWC—the connections which join each length of casing, one to another. Experience to date with DWC has demonstrated a need for a more robust, yet economical casing connection to withstand the additional rigors of dynamic loading and frictional wear caused by rotating the string while drilling.
BRIEF SUMMARY OF THE INVENTION
The invention comprises the following modifications of the standard API Buttress threaded coupling only, while maintaining it's compatibility with standard API Buttress threaded Pins:
1. The coupling threads only are modified with multiple tapers to reduce and equalize makeup stresses through the thinner cross-sections of both the pins and coupling, thereby minimizing the possibilities of thread galling during connection assembly. 2. The multiple thread taper reduces the bearing stresses, and therefore the localized stress risers in the run-out pin threads where the connections commonly fail in fatigue, under rotational cyclic loading. 3. The coupling is shortened to allow abutment of the two pins at the center of the coupling maximizing the torque capabilities of the connection. 4. The coupling can be formed with an integral, sacrificial wear-sleeve extension, protecting the coupling proper from frictional wear as the casing is rotated down the well bore.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING(S)
FIG. 1 is a side view, partially in cross-section, of two pipes joined with a coupling of the prior art.
FIG. 2 is a side view, partially in cross-section, of two pipes joined with a prior art coupling having a center section of increased thickness.
FIG. 3 is a side view, partially in cross-section, of two pipes joined with a coupling according to the present invention.
FIG. 4 is a side view, partially in cross-section, of two pipes joined using an alternative embodiment of the present invention.
FIG. 5 is a side view, partially in cross-section, of two pipes joined using a third embodiment of the present invention.
FIG. 6 is a side view, partially in cross-section, of two pipes joined using a fourth embodiment of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
Casing Couplings of the Prior Art
Referring now to the drawing in FIG. 1 , a standard API Buttress Threaded casing string 10 and coupling 15 according to the prior art is illustrated. The casing string 10 includes two casing sections, or pipes, 11 and 12 , having pin ends 11 A and 12 A, interconnected with a coupling 15 according to the prior art. FIG. 1 shows the connection fully assembled. Note the separation between pin ends 11 A and 12 A. This gap between the pins is commonly known as the “J” area.
Still referring to FIG. 1 , the casing members 11 and 12 include pin threads 13 and 14 on the outside end of each casing section, the threads mating with the threaded internal surface of the coupling 15 . The coupling 15 includes a first end 18 and a second end 19 with internal threaded surfaces 16 and 17 . The threads are preferably tapered API Buttress threads as are commonly used in the industry and in this application. However, other thread forms may be used.
Now referring to FIG. 2 , which shows another oil well casing connection in accordance with U.S. Pat. No. 5,015,017, a casing string is illustrated generally at 20 . The casing string 20 includes two casing sections 21 and 22 interconnected with coupling 25 , and the casing sections include external API Buttress pin threads 23 and 24 which mate with matching coupling threads 26 and 27 .
Essentially FIG. 2 is the same as FIG. 1 with the exception that the “J” area between pin ends 23 & 24 contains an integral reinforcing cross-section 30 of the coupling 25 . This heavy cross-section 30 substantially improves the strength of the coupling by converting the structural/mechanical behavior of the coupling from a simple beam to a cantilever beam. The visual contrast is readily noted by comparing the cross-sections of coupling 15 ( FIG. 1 ) and coupling 25 ( FIG. 2 ). Both connections preferably use the Standard API Buttress threads and are interchangeable with each other.
Casing Couplings According to the Present Invention
With reference to FIG. 3 and this invention, a casing string is illustrated with two casing sections 41 and 42 interconnected with coupling 45 and the casing sections include externally threaded pins 43 and 44 , which mate with internal coupling threads 60 . Threaded pins 43 and 44 contain standard API Buttress Threads with a constant taper. The faces of the two pin ends 65 are square cut to furnish maximum bearing face when butted together at center 50 of coupling 45 .
Again referring to FIG. 3 and this invention, it is standard with the API Buttress Thread Form for the coupling threads 60 and pin threads 43 , 44 to have identical thread tapers so as to produce uniform radial thread interference through the full length of the thread profile. When the connection is assembled, it is this thread interference that creates the contact pressure and therefore the sealing capabilities of the mating threads.
It will be further noted in FIG. 3 that the thread tapers of the pin and coupling members result in variable cross-sections along the thread profile of each member, with a thinner cross-section at pin ends 65 and similar thinning cross-sections at coupling ends 53 . When the connection is assembled it is seen that the thinner cross-sections of the respective pin and coupling members are opposite the heavier cross-sections of the mating member. The cross-sections therefore are unbalanced at the thinner ends of both members. When the connection is assembled, it is this imbalance between these cross-sections and the resulting excessive hoop stresses in the thinner cross-sections, that this invention addresses.
Referring again to FIG. 3 , it is evident that a uniform taper between the pin and coupling threads results in uniform interference along the thread profile. However, as pointed out above, the cross-sections of the mating members vary along the thread profile. Therefore, if the interference between the threads is uniform, but the cross-sections behind the threads are variable, then the resulting hoop stresses created in the cross-sections must also be variable; graduating from low stresses in the thicker part of the cross-section to high stresses in the thinner part. Indeed it has been found through Finite Element Analysis (FEA) that, after assembly, the hoop stresses in the thinner cross-sections of both the pins and coupling can exceed the yield strength of the steel. In addition to the negative impact on the yield strength, in the thinner portions of the mating members this differential yielding at the thin vs. thick cross-sections also causes differential movement between the threads at these same high stress points. This differential movement, at the high stress points, in turn results in thread galling in both coupling and pins at 65 and 66 . It is also anticipated that these same high stressed areas, particularly at the run-out threads 66 of the pin members 43 and 44 , could result in fatigue failure when the connections are used in the drilling mode (DWC).
Referring again to FIG. 3 . there is shown a cross-sectional view of a shortened API Buttress Threaded coupling 45 connecting two Buttress Threaded Pins 43 and 44 that abut at the center of the coupling 45 . FIG. 3 illustrates this shortened and multiple tapered coupling designed to:
1) Moderate the concentrated high stresses previously outlined 2) Minimize the thread galling in the areas of high stress 3) Maintain compatibility with standard API Buttress threaded pin members 4) Create a high torque connection by butting the pin ends at the center of the coupling
To accomplish these objectives the thread tapers in only the coupling member 45 are modified at the areas of high stress; i.e., the areas of cross-sectional imbalances at coupling ends 53 and pin ends 65 . As shown in FIG. 3 the thread taper in coupling 45 is segmented into sections S 1 , S 2 and S 3 . In the present invention the taper in section S 2 is maintained at the API standard taper. The taper in section S 1 is greater than the taper in section S 2 , and the taper in section S 2 is greater than the taper in section S 3 . The variable tapers in coupling 45 relative to the uniform tapers of pins 43 and 44 reduce bearing pressures in the mating thread elements in areas of the connection with unbalanced cross-sections; i.e. 65 on the pin ends and 53 of the coupling ends. The employment of multiple tapers reduces the contact pressure in the overstressed areas S 1 and S 3 and thus mitigates the problems of high stresses, thread galling and fatigue failure.
In one preferred embodiment, the threaded section on each side of a 7-inch API Buttress coupling is divided into three sections as previously described. The lengths and tapers for each section in this preferred embodiment are:
Section
Length (in)
Taper (in./in.)
1
1.784
0.07525
2
1.716
0.06250
3
1.125
0.05556
The section lengths and tapers employed in this invention are designed to reduce contact pressure in areas of the connection where cross-sections are unbalanced.
It might be noted that other taper profiles, such as elliptical or curved, might be used, but the segmented profile is preferred because it maximizes the length of section S 2 which has the same taper on both members therefore maximizing sealing integrity. It is emphasized that only the coupling tapers need be modified.
It is also emphasized that the pin threads 43 and 44 should be made to standard API Buttress specifications with no modifications to length or taper. This allows the casing pipes to be threaded by the many API licensed machine shops or mills in the world. By contrast there are only a few coupling manufacturers in the world and most have the modern equipment to machine the modifications required by this invention. Also couplings are easily transportable as opposed to 40′ lengths of pipe.
Again in FIG. 3 , the coupling is shortened by approximately ¾ inch, removing what is commonly known as the “J” area between the two pin members as previously pointed out in FIG. 1 . In this invention, elimination of the “J” area allows the two pins to butt one another at the coupling center thereby maximizing the torque capabilities of the connection and its use for DWC.
Now referring to FIG. 4 , an optional unthreaded extension 70 can be integrally machined on one end of the coupling 55 . The purpose of the extension is to provide a sacrificial wear sleeve to protect the main body of the coupling as the casing is rotated down the well bore. The wear sleeve would have the same outside diameter as the coupling with the inside diameter being slightly larger than the casing so as to slip over the casing when the connection is assembled. As an option, the wear sleeve can be hard banded if excessive abrasion is anticipated.
Again at FIG. 4 the inside diameter of the wear sleeve is uniform from the face 72 for a specific distance toward the center of the coupling, then is tapered outward toward the coupling OD 73 . This design detail is provided to permit the threading tool to cut perfect (full-formed) threads over the entire coupling thread length without cutting into the ID of the sacrificial wear sleeve. Elimination of machining marks in the wear sleeve near the coupling threads reduces the possibility of fatigue failures in the sacrificial wear sleeve extension.
In an alternative embodiment illustrated in FIGS. 5 and 6 , an API Buttress coupling has an internal reinforcing cross-section 80 at the center or in the “J” area. In this embodiment, each pin engages an internal square shoulder 82 at the heavy cross-section thereby maximizing the torque capability of the connection for its use for DWC.
As in the embodiment shown in FIG. 4 , an optional unthreaded extension 70 can be integrally machined on one end of the coupling 55 . This feature is illustrated in FIG. 6 . The purpose of the extension 70 is to provide a sacrificial wear sleeve to protect the main body of the coupling as the casing is rotated down the well bore. The wear sleeve would have the same outside diameter as the coupling with the inside diameter being slightly larger than the casing so as to slip over the casing when the connection is assembled. As an option, the wear sleeve can be hard banded in area 74 if excessive abrasion is anticipated.
Again, as in the embodiment shown in FIG. 4 , the inside diameter of the wear sleeve is uniform from the face 72 for a specific distance toward the center of the coupling, then is tapered outward toward the coupling OD 73 . This design detail is provided to permit the threading tool to cut perfect (full-formed) threads over the entire coupling thread length without cutting into the ID of the sacrificial wear sleeve. Elimination of machining marks in the wear sleeve near the coupling threads reduces the possibility of fatigue failures in the sacrificial wear sleeve extension.
It should be noted and anticipated that certain changes may be made in the present invention without departing from the overall concept described here and it is intended that all matter contained in the foregoing shall be interpreted as illustrative rather than in a limiting sense. | A modified API Buttress threaded casing connection is disclosed for use in drilling oil and gas wells in lieu of using conventional drill pipe. The coupling threads only are multiple tapered yet can be mated with standard API Buttress pin threads having a single taper. The coupling is also shortened to permit abutment of the mating pins at the center of the coupling and can be further enhanced with an integral, sacrificial wear sleeve on one end of the coupling. | 5 |
This application is a division of application Ser. No. 564,319, filed 12/22/83 now U.S. Pat. No. 4,632,375.
DETAILED DESCRIPTION OF THE INVENTION
This invention provides a servo-clamping device which, by means of the multi-directional rotary and suspended swinging movable clamping claw, is positioned in the clamping jaw groups, whereas the clamping jaw groups can be driven on one direction or adjusted in sideway displacements, or adjusted in angular displacements or in suspended swinging or in small angular rotations, or are set separately in a multi-direction form. Therefore, this design can be installed on the common processing work benches, and machine tools, and firmly fixed on the work benches on the floor so as to easily lock up the servos in proper directions, positions and angles in response to work pieces in various shapes and positions as its feature.
FIG. 1 shows the three-dimensional view of the servo-clamping device relative to the movable clamping claw with a a concave clamping surface of the examplary example in conjunction with the present invention.
FIG. 2 shows the view of three movable clamping claws clamping a small triangular work piece of the exemplary example in FIG. 1.
FIG. 3 shows the view of four movable clamping claws clamping a big triangular work piece of the exemplary example in FIG. 1.
FIG. 4 shows the view of four movable clamping claws clamping a small cylindrical work piece of the exemplary example in FIG. 1.
FIG. 5 shows the view of four movable clamping claws clamping a big round work piece of the exemplary example in FIG. 1.
FIG. 6 shows the view of four movable clamping claws clamping a big elliptic work piece of the exemplary example in FIG. 1.
FIG. 7 shows the view of four movable clamping claws clamping a small elliptic work piece of the exemplary example in FIG. 1.
FIG. 8 shows the view of four movable clamping claws clamping an irregular multi-lateral work piece of the examplary example in FIG. 1.
FIG. 9 shows the view of four movable clamping claws clamping a diamond-shaped work piece of the exemplary example in FIG. 1.
FIG. 10 shows the view of four movable clamping claws clamping a parallel work piece of the exemplary example in FIG. 1.
FIG. 11 shows the top view of the concave arc of the convex clamping surface of the clamping claw of the exemplary example in conjunction with the present invention.
FIG. 12 shows the top view of the multi-lateral convex clamping surface of the clamping claw of the exemplary example in conjunction with the present invention.
FIG. 13 shows the top view of the plane and convex and concave teeth of the convex clamping surface of the movable clamping claw of the exemplary example in conjunction with the present invention.
FIG. 14 shows the top view of the plane and convex arc of the convex clamping surface of the clamping claw of the exemplary example in conjunction with the present invention.
FIG. 15 shows the three-dimensional bottom view of the movable claw of the exemplary example in conjunction with the present invention.
FIG. 16 shows the three-dimensional bottom view of the convex rim of the top of the clamping claw of the exemplary example in conjunction with the present invention.
FIG. 17 shows the three-dimensional parts exploded view of the knockdown movable claw of the exemplary example in conjunction with the present invention.
FIG. 18 shows the profile view of the knockdown movable claw of the exemplary example in conjunction with the present invention.
FIG. 19 shows the top view of the multi-functional movable clamping claw in conjunction with the present invention.
FIG. 20 shows the A--A cross-sectional view of the multi-functional movable clamping claw in conjunction with the present invention.
FIG. 21 shows the B--B cross-sectional view of the multi-functional movable clamping claw in conjunction with the prefunctional movable clamping claw in conjunction with the present invention.
FIG. 22 shows the three-dimensional view of the multi-functional movable claw in conjunction with the present invention.
FIG. 23 shows the three-dimensional view of the multi-layer and multi-functional movable claw positioned by the slide seat in conjunction with the present invention.
FIG. 24 shows the cross-sectional view of the movable claw positioned by the ball shaft on the clamping jaw and adjustable by three-dimensional swing in conjunction with the present invention.
FIG. 25 shows the three-dimensional parts exploded view of the ball shaft and the multi-functional movable claw in conjunction with the present invention.
FIG. 26 shows the cross-sectional view of the movable claw positioned by the separable ball shaft in conjunction with the present invention.
FIG. 27 shows the three-dimensional view of the separable ball shaft and movable clamping claw in conjunction with the present invention.
FIG. 28 shows the cross-sectional view of the assembly of the multi-sectional and multi-layer ball shaft and movable claw in conjunction with the present invention.
FIG. 29 shows the three-dimensional parts exploded view of the multi-sectional and multi-layer ball shaft and movable claw in conjunction with the present invention.
FIG. 30 shows the cross-sectional view of the movable claw with a ball center in conjunction with the present invention.
FIG. 31 shows the three-dimensional parts exploded view of the multi-functional movable clamping claw with a ball center in conjunction with the present invention.
FIG. 32 shows the cross-sectional view of the assembly of the clamping claw and the slide seat with angular locking-up functions in conjunction with the present invention.
FIG. 33 shows the three-dimensional view of the fixing jaw with two movable clamping claw groups in conjunction with the present invention.
FIG. 34 shows the view of the clamping block group of the fixing jaw in conjunction with the present invention.
FIG. 35 shows the view of the rotable auxiliary block of the clamping jaw group in conjunction with the present invention.
FIG. 36 shows the view of the multi-sectional movable clamping claw groups in conjunction with the present invention.
FIG. 37 shows the view of the multi-sectional movable clamping claw group with different oblique cross sections in conjunction with the present invention.
FIG. 38 shows the view of the rotable and rotary movable clamping claws clamping a work piece in conjunction with the present invention.
FIG. 39 shows the view of the rotable and rotary movable clamping claws clamping a work piece in conjunction with the present invention.
FIG. 40 shows the cross-sectional view of the assembly of the movable clamping claw rotable along rectangular co-ordinates in conjunction with the present invention.
FIG. 41 shows the three-dimensional parts exploded view of the movable claw rotable along rectangular coordinates in conjunction with the present invention.
FIG. 42 shows the top view of the clamping jaw which clamps with its one side and has a single clamping claw in conjunction with the present invention.
FIG. 43 shows the view of the one-sided clamping jaw with a single clamping claw clamping a work piece in an oblique way in conjunction with the present invention.
FIG. 44 shows the three-dimensional view of the open-type are positioning seat of the clamping jaw group which positions the clamping claws in conjunction with the present invention.
FIG. 45 shows the three-dimensional view of the open-type big arc positioning seat of the clamping jaw group which positions the clamping claws in conjunction with the present invention.
FIG. 46 shows the three-dimensional view of the clamping jaw group each of the two sides of which clamps the tooth-shaped work piece with its singular multi-functional clamping claw respectively in conjunction with the present invention.
FIG. 47 shows the three-dimensional view of the box-type clamping jaw group with a slide seat and two movable clamping claws on one side of the clamping jaw group in conjunction with the present invention.
FIG. 48 shows the three-dimensional view of the clamping jaw group with individual rotary seats in conjunction with the present invention.
FIG. 49 shows the three-dimensional view of the clamping jaw group which holds down a semi-cylinder by its movable clamping claw rotable along rectangular coordinates in conjunction with the present invention.
FIG. 50 shows the three-dimensional view of positioning of the slide seat by the locking bolt of the dovetail keyway in conjunction with the present invention.
FIG. 51 shows the cross sectional view of the positioning of the slide seat by the locking bolt of the dovetail keyway in conjunction with the present invention.
FIG. 52 shows the top view of the clamping jaw group with two-end guided movable positioning slide seat in conjunction with the present invention.
FIG. 53 shows the top view of the clamping jaw group with straight line and arc guided moving positioning slide in conjunction with the present invention.
FIG. 54 shows the three-dimensional exploded view of the driving of the clamping jaw group by the socket seat and ring-and-post support block in conjunction with the present invention.
FIG. 55 shows the top view of the clamping view of the work piece by the rotation of the clamping jaw group under the driving of the socket seat and ring-and-post support block in conjunction with the present invention.
FIG. 56 shows the cross sectional view of the clamping of the work piece by the rotation of the clamping jaw group under the driving of the penetration rod and ring-and-post support block in conjunction with the present invention.
FIG. 57 shows the three-dimensional view of the go-through rod and ring-and-post support block to drive the clamping jaw group in conjunction with the present invention.
FIG. 58 shows the three-dimensional parts exploded view of the spherical coupling structure on the bottom of the clamping jaw group in conjunction with the present invention.
FIG. 59 shows the three-dimensional parts exploded view of the spherical coupling structure on the bottom of the clamping jaw group in conjunction with the present invention.
FIG. 60 shows the cross sectional view of the spherical coupling structure on the bottom of the clamping jaw group in conjunction with the present invention.
FIG. 61 shows the view of the spherical coupling actions of the spherical coupling structure on the bottom of the clamping jaw group in conjunction with the present invention.
FIG. 62 shows the three-dimensional view of the slide seat of the clamping jaw group which can slide sideway and swing up and down in conjunction with the present invention.
FIG. 63 shows the cross sectional view of the slide seat of the clamping jaw group which can slide sideway and swing up and down in conjunction with the present invention.
FIG. 64 shows the cross sectional view of the inner concave face provided on the lower side of the slide plane (with an angular locking) of the clamping jaw group in conjunction with the present invention.
FIG. 65 shows the view of the clamping of the work piece by the inner concave face provided on the lower side of the slide plane to strengthen the angular locking function of the angular locking of the clamping jaw group in conjunction with the present invention.
FIG. 66 shows the three-dimensional parts exploded view of the jaw seat and the changeable clamping jaw in conjunction with the present invention.
FIG. 67 shows the three-dimensional view 1 of the changeable clamping jaw without the removable clamping claw in conjunction with the present invention.
FIG. 68 shows the three-dimensional view of the changeable clamping claw in conjunction with the present invention.
FIG. 69 shows the three-dimensional view of the jaw base seat with support walls in conjunction with the present invention.
FIG. 70 shows the three-dimensional view of the support walls formed connection of several arcs of the jaw base seat in conjunction the present invention.
FIG. 71 shows the side view of the two-end fixed jaw and middle slide jaw in conjunction with the present invention.
FIG. 72 shows the front view of the movable clamping claw to be directly plugged in the jaw base seat by its plug rod in conjunction with the present invention.
FIG. 73 shows the first view of the movable clamping claw to be directly plugged in the jaw base seat by its bolt in conjunction with the present invention.
FIG. 74 shows the view of the installation of the movable clamping claw by adjusting the plug socket in conjunction with the present invention.
FIG. 75 shows the view of adjusting the plug socket to rotate and plug in the movable clamping claw in conjunction with the present invention.
FIG. 76 shows the three-dimensional parts exploded view of the bolt which can penetrate through the multi-layer movable clamping claw in conjunction with the present invention.
FIG. 77 shows the top view of the clamping of a ball work piece by the auxiliary blocking block in conjunction with the present invention.
FIG. 78 shows the three-dimensional view of the clamping of a ball work piece by the auxiliary blocking block in conjunction with the present invention.
FIG. 79 shows the three-dimensional view of the small blocking block and its driving structure additionally provided on the blocking block in conjunction with the present invention.
FIG. 80 shows the view of the clamping of the work piece by the small blocking block on the blocking block in conjunction with the present invention.
FIG. 81 shows the top view of the clamping device as positioned on the movable base seat in conjunction with the present invention.
FIG. 82 shows the view of the clamping device as positioned on the electrical-power-driven base seat in conjunction with the present invention.
FIG. 83 shows the three-dimensional view of the work-bench-type base seat to be firmly fixed on the floor in conjunction with the present invention.
FIG. 83-1 shows the inwardly inclining connection holes on the positioning seat and the positioning slide seat of the work-table (bench)-style base seat in conjunction with the present invention.
FIG. 83-2 shows the branch-type fork connection holes on the positioning seat or positioning slide seat of the work-table(bench)-style base seat in conjunction with the present invention.
FIG. 83-3 shows the wave-shaped or pinacle-shaped connection holes on the positioning seat or positioning slide seat of the work-table (bench)-type base seat in conjunction with the present invention.
FIG. 83-4 shows the three-dimensional view of the movable clamping claws which can be inserted and fixed in the positioning seat or positioning slide seat in conjunction with the present invention.
FIG. 83-5 shows the top view of the clamping side of the plane and the eccentric arc face of the movable clamping claw in conjunction with the present invention.
FIG. 83-6 shows the top view of the clamping side of the plane and the eccentric arc face of the movable clamping claw in conjunction with the present invention.
FIG. 83-7 shows the three-dimensional view of the clamping side and the push handle of the plane and the eccentric arc face of the movable clamping claws in conjunction with the present invention.
FIG. 83-8 shows the view of the clamping of the work piece by the movable clamping claw of eccentric arc face in conjunction with the present invention.
FIG. 83-9 shows the three-dimensional view of the rubber and metal clamping faces provided on the wooden square movable clamping claw in conjunction with the present invention.
FIG. 83-10 shows the three-dimensional view of the rubber, wooden or other metal clamping face provided on the iron or steel square movable clamping claw in conjunction with the present invention.
FIG. 84 shows the three-dimensional view of the clamping jaw group, one side of which is multi-group and separately driven in conjunction with the present invention.
FIG. 85 shows the three-dimensional view of the clamping jaw group, two sides of which are multi-group and separately driven in conjunction with the present invention.
FIG. 86 shows the top view of three groups of the movable clamping claws with the intersection of their driving loci at one point in conjunction with the present invention.
FIG. 87 shows the top view of three groups of the movable clamping claws with the intersection of their driving loci at one point and of the clamping of a work piece by their auxiliary sides in conjunction with the present invention.
FIG. 88 shows the top view of three groups of the movable clamping claws, when their driving loci form of a triangle in conjunction with the present invention.
FIG. 89 shows the top view of clamping a very small work piece by rotations of the movable clamping claws, when the driving loci of three groups of the movable clamping claws form a triangle in conjunction with the present invention.
FIG. 90 shows the top view of four groups of the movable clamping claws, when their driving loci form a rectangle in conjunction with the present invention.
FIG. 91 shows the top view of the clamping a very small work piece by rotations of the movable clamping claws, when the driving loci of four groups of the movable clamping claw form a rectangle in conjunction with the present invention.
FIG. 92 shows the three-dimensional view of the clamping structure as installed on the mechanical arm in conjunction with the present invention.
The main constituent structure of the servo-clamping device under the present invention composes movable clamping claw, clamping jaw group, driving device, and base seat which are separately described in sequence as follows:
Movable clamping claw 1 is a cylinder in a proper length, whereas the clindrical ring is in a form of full round ring rim at a proper angle and, when positioned at clamping jaw 2, serves as rotary slide face, while its other part will, at a proper angle, symmetrically or assymmetrically stretches out the clamping face with a trapezoidal cross section; the top face of this trapezoid is a smaller clamping face as shown in FIG. 1; movable clamping claw 1 can be positioned, adjusted and rotated in positioning seat 21 of clamping jaw 2 along the round back of this movable clamping claw.
As shown in FIG. 2, 3, 4, 5, 6, 7, 8, 9, and 10, movable clamping claw 1 can be provided in an equal number and opposite positions or an unequal number and staggered positions on each side of clamping jaw group 2, by which the clamping face of movable clamping claw 1 can be rotated, and adjusted as desired to make the clamping device of the present invention easily clamp triangular, round, elliptic, diamond, parallel or irregular work pieces in different sizes and also make various movable clamping claws 1 tightly clamp the work piece with the clamping direction of various bearing forces concentrated at the central position of the work piece by all possible means.
As shown in FIGS. 11, 12, 13 and 14, the part of the clamping face of movable clamping claws 1 can, along with the situation needed, be made with a trapezoid with its top face in a concave arc or equilateral polygonoor plane and concave and convex cylindrical face in different sectional radi and arrayed in order of sizes or vertical wheel teeth; also their various clamping faces can, according to their respective shapes, be cut and provided with longitudinal or latitudinal or oblique concave slots in an equal depth or their various clamping faces can be embossed with patterns as its feature.
On the back position of the coordination round arc at the bottom of the above-cited clamping claw 1 is provided with arc guide slot 18 in a proper depth and width and with an arc to accommodate fixing shaft 101 when positioned in positioning seat 21 of clamping jaw group 2 in order limit the maximum rotary scope of movable claw 1 as shown in FIG. 15; its top can have a flange with the small joint in a bigger form as shown in FIG. 16, which, when movable clamping claw 1 is set in positioning seat 21 of clamping jaw group 2, makes the elevated part of movable clamping claw 1 have a larger rotary rim of the back part to fully cover up the rotary connection seam between clamping jaw 2 and movable clamping claw 1, which, in turn, prevents very small and fine residual dedgs left by the work pieces forming falling into the connection seam to damage positioning seat 21 or the slide face of movable clamping claw 1 during the clamping and processing work.
As shown in FIG. 17, movable clamping claw 1 under the present invention can also be composed by semi-cylinder 11 and compensatory block 12; from the center of semi-cylinder 11 or compensatory block, extends out rotary shaft or the center of semi-cylinder 11 or compensatory block has contral shaft hole 14 to accommodate the rotary shaft penetrating into and installing in central shaft hole 14, a press-down spring 15 is to position the rotary shaft; on rotary shaft 13, semi-circular slot with a fixed arc length is provided; at the opposite position in central shaft hole 14, one or more sets of springs 17 and steel beads 16 are installed to make compensatory block 12 rotatable and adjustable, and also steel beads 16 are used to couple the changeable positions of this semi-circular slot, thus making sound indications of the fixed rotational torque.
As shown in FIG. 19, movable clamping claw 1 of the present invention to clamp work piece can also, be fixing shaft 101, be positioned in positioning seat 21 of clamping jaw group 2 or in slidable slide seat 201, whereas this movable clamping claw 1 can be a cylinder, or polygon, in a proper thickness, or in the form that, at a proper arc, the cylindric face of a cylinder is cut flat and on the rest arc rim, concave and convex arcs parallel to the central line are made in different radi and arrayed in sequence, and concave and convex arcs are made in different sectional roundnesses large and small tooth forms in different depths and in different radi in longitudinal cylindrical face; spring 17 and steel beads 16, which are set in advance in movable clamping claw 1, and the semi-circular slots which are drilled and provided at equal intervals on the perimeter of fixing shaft 101 can form multi-functional and movable clamping claw 1 with audio and adjustable and rotatable features between movable clamping claw 1 and fixing shaft 101 in design.
The above-cited movable clamping claw 1 consists of small and large tooth forms in proper cylinderical arcs which can be arrayed in order of sectional roundness and tooth depths; in various tooth slots, square longitudinal grooves are cut, whereas the connection part between the tooth faces and the square longitudinal slots forms in an arc formation, or a tooth tip and arc formation; besides, the longitudinal cylindrical arcs of movable clamping claw 1 are in different radi with respect to the arc positions; as to the convex arc as shown by line A--A in FIG. 20, if they are on other cross sections, the radi of their arcs are different from one another, just as the concave arcs shown by line B--B in FIG. 21; as to the above said multi-functional movable clamping claw 1, it is also possible to cut V-shaped slot in the central ring on the cylindrical face as shown in FIG. 22 as the feature.
As for the multi-functional movable clamping claws 1 under this design, its fixing shaft locked by the conventionally used mechanical positioning and locking method in positioning seat 21 or slide seat 201 of clamping jaw group 2; if both of the fixing jaw and the movable jaw have the design of movable clamping claws 1 at the same time, movable clamping claws 1 on both ends can be provided symmetrically or positioned staggeredly; when multi-functional movable clamping claws are clamping a work piece, movable clamping claws can, according to the outer configuration of the work piece, be rotated to select proper clamping faces to clamp the work piece or slide seats 201 are adjusted simultaneously to make movable clamping claws 1 get the best clamping position, so that even the common tooth faces, arc faces or angular bodies in different sizes can be clamped tightly under the status of not being damaged to successfully complete the processing operations.
Device of the multi-functional movable claws 1 on the above-said clamping jaw group 2 or slide seat 201 can be in a form of a single fixed shaft with only one multi-functional movable clamping claw 1 or with multi-layer individual movable clamping claw 1 as shown in FIG. 23; clamping jaw group 2 which is installed with multi-layer movable clamping claws 1 can be in a form of integral structure, in which only positioning seat 21 is cut and provided for the rotations of movable clamping claws 1 in order to reinforce the strength of this integral body; when this design is applied to clamping jaw group 2, they can be set in a parallel installation with several fixed shafts 101, and each of them has a single or multi-layer movable clamping claws 1 as a special feature; clamping jaw group can also have multi-layer movable clamping claws 1 whereas support ring 102 in a bigger diameter is installed between layers or in a group of several layers and the arc rim of exposed over the clamping faces is cut flatly to directly support or bear clamping jaw 2 or slide seat 201 so as to reinforce the integral structure.
The present invention can further make the above-cited multi-functional movable clamping claws 1 have a three-dimensional swinging function as shown in FIGS. 24 and 25, wherein the main structure is composed with movable clamping claws 1, clamping ring 103, ball 104, and upper and lower positioning shafts; clamping ring 103 and movable clamping claws 1 are coupled into a ring-shaped post by bolts and after coupled they form a ball socket just to cover ball 104, this ball socket goes up and down and forms an arc and smoothly sliding opening to allow upper and lower positioning shaft 105 and 106 easily penetrating this opening and also supporting the ball 104; thus by this way, movable clamping claws 1 can swing up and down or rotate in the box-type jaw or slide seat 201 to pick up the best clamping position. Furthermore, the above-cited design can be an integral movable clamping claws 1, thus one side of its central part is in a ball-type concave form and its other side is in ball-type convex form, and both of these two ball arcs have a same center as shown in FIGS. 26 and 27; its concave socket seat is coupled and supported by a separately ball 104, while the other convex side is supported by the concave arc end of upper positioning shaft 105, and it can also make a part of a ball 104 sunk in slide seat 201 or the frame of clamping jaw 2 in order to reinforce the stability of ball 104; the central concave arc and convex arc of movable clamping claws 1 of this design can be rotated and adjusted at the same center to get the best clamping position.
This invention is features in the design of the rotational center by ball 104 for the multi-functional clamping claws 1, or this can be designed in multi-layer ball 104, which in connected by central shaft 107 to form multi-layer movable claws 1 in its structure as shown in FIGS. 28 and 29, and this structure can even clamp work pieces in more complex geometric forms.
The above-cited design can also be an integral body composed of multi-functional movable clamping claws 1 and ball 104 as shown in FIGS. 30, 31 and 32, which are coupled simply by upper and lower positioning shafts 105 and 106 (their end faces are in a form of concave arc), or slide seat 201, or clamping jaw 2, which enables multi-functional clamping claws 1 also making three-dimensional adjustments and swingings.
As shown in FIG. 33, movable clamping claws 1 of the servo-clamping device of this invention can further be in a form of the clamping side of the clamping jaw in the same body or an auxiliary block 22 which can make rotary adjustments and is also in a position between movable clamping claws 1 and clamping jaw 2, the center of this auxiliary block 22 can have perpendicular clamping face, however its end face is, according to the selected directions and slopes, cut into an oblique section, and along the center of this oblique section, post 221 perpendicular to this oblique section protrudes and the central line of this post 221 is not perpendicular to the clamping face of the jaw; concave slot 222 is provided at the near end of rotary shaft 13, whereras press spring 223 can be inserted into this concave slot 222 when movable clamping claw 1 is installed; as shown in FIG. 33, one end of the oblique cross section of auxiliary block 22 on the clamping face opposite to cylindrical movable clamping 1 is also cut into an oblique section, in the center of this oblique section, a postioning hole 14 is drilled and provided, and this positioning hole 14 has two stages, since the diameter of its inner aperture is bigger and the diameter of its outer aperture is same to that of post 221, as shown in FIG. 33, this makes press spring 223 inserted at the inner aperture into concave slot 222 of post 221 to couple the post body and the movable clamping claw, thus making the oblique sections of both of them closely contacted in a combination as shown in FIG. 34; the outer end face of movable clamping claw 1 has a perpendicular rim, this end face can, according to actual needs, be imbossed with clamping patterns or engraved and provided with other geometric concave and convex structures to special work pieces.
As shown in FIG. 33, along the rim of the outer aperture of positioning hole 14 of movable clamping claw 1, one or more sets of steel beads 16, and spring 17 can be installed to coordinate with the semi-circular slots at equal intervals and in a ring form on the root of post 221 to make movable clamping claw 1 have audio equal amount micro-adjustments in directions.
The auxiliary block 22 of the above-said design can be a separate body in respect to clamping jaw 2; as shown in FIGS. 35 and 36, a rotary hole is provided at a selected position on clamping jaw or slide seat 201 to accommodate the rotary post 224 (in a diameter same to that of this rotary hole) extended out from the back of auxiliary block 22; rotary post 224 is provided with round slot 225 in a ring form, so during positioning, a plug rod 226 penetrates through the bottom of clamping jaw 2 or slide seat 201 and then inserts in round slot 225 to avoid auxiliary block getting off clamping jaw 2; the designed plug rod 226 can be in a round or square form but its diameter or width must be equal to that of round slot 225, while audio equal amount rotary adjustment device is also set between rotary post 224 and clamping jaw 2.
The movable clamping claw 1 of this design can also be composed by two or more sections as shown in FIGS. 36 and 37, both sides of which can have unidirectional or different directional oblique section, or can also have an oblique section on its one end and a perpendicular plane on its other end, while the way of their connection is accomplished by post 221 and press spring 223 as above-cited, or is coupled by rotary post 224 and plug rod 226.
As shown in FIG. 38, auxiliary block 22 of the present invention can be positioned and rotated, by above-cited plug rod 226, in the clamping side of the clamping jaw or slide seat 201, so during its clamping of the work piece, this can adjust auxiliary block 22 to make space wider in the upper position and narrower in the lower position, thus forming the effective locking effects, or as shown in FIG. 39, this will adjust auxiliary block to make spaces wider in its outer side and narrower in its inner side, and then movable clamping claws 1 is rotated to sandwich ball-shaped work pieces.
The above-cited movable clamping claws 1 that have the rotary cylindrical face can be positioned by rotary base block 33, as shown in FIGS. 40 and 41, post 221 directly extends and protrudes out from the clamping side of clamping jaw 2 or protruded from a auxiliary block 22 and then protrudes from post 221 and is coupled with base block 23 by press spring 223, to make this base block become a positioned rotary body or a rotational body along the oblique face of auxiliary block 22, the end of base block 23 of this design is in a form of rectangular body, concave arc positioning seat 21 is provided on the end face, one end of positioning seat 21 protrudes positioning rod 231 which penetrates through and presses movable clamping claws 1, or its both ends are provided with positioning holes to let positioning rod 231 penetrate through and stay to position movable clamping claws 1, or the arc wall of positioning seat 21 is provided with guide movable key or slot as shown in FIG. 49 to make movable clamping claws 1 with guide slot or key positioned and rotated. In this structure, movable clamping claws 1 can be in a form of a semi-cylinder or semi-cylinder with trapezoidal section and portions of its two ends protruding out from positioning seat 21 are made with protective lips in a larger radius to fully cover the top rim of positioning seat 21 of base seat 23; this design makes the position adjustments of movable clamping claws 1 can be firstly made by the rotation of base block 23 to change the direction of the post of movable clamping claws 1, and then rotated along the guide slot of movable clamping claws 1 themselves, thus forming rotations and displacements in rectangular coordinates to accomplish the micro adjustments on work pieces.
As shown in FIGS. 42, 43, 44, and 45, the clamping side of clamping jaw group of this invention can have a pair or more concave arc structure, or can also have concave structure with concave parts in different depths, such concave parts are the positioning seats 21 for movable clamping claws 1, a fixing shaft 101 or limit rod can protrude out from the center or non-central position of the arc to penetrate through movable clamping claws 1 to control the action position of movable clamping claws 1 or one or more guide keys or slots on the arc walls can engage opposite slots or keys on movable clamping claws 1; the clamping jaw group 2 of this design can also have a top cover structure to make the limit rod or fixing shaft 101 penetrate through and install in the top cover, so movable clamping claws 1 have better positioning and clamping effects as showing in FIG. 46 and 47.
As shown in FIG. 48, the positioning movable clamping claw 1 of clamping jaw group 2 of this invention can be inserted into the bearing face of clamping jaw group 2 by individual rotary seat 24 and this then makes movable clamping claws 1 positioned on rotary seat 24, thus forming a design to change movable clamping claws 1 as desired. The radi of the arc wall of the clamping side of clamping jaw group 2 are different, whereas the radius on its upper part is larger and the radius of its lower part is smaller, and penetration and installation hole 211 is provided on clamping jaw group 2; the upper section of rotary seat 24 is in a form of a semi-cylinder, and, at the connection between its lower and upper sections, a comparatively protruding bearing face is provided; a plug rod 211 which is smaller than penetration and installation hole protrudes from the bottom of this bearing face; the upper and lower sections of rotary seat 24 form a semi-round body with its upper radius smaller than its lower radius, whereas this slope matches with the oblique arc wall of clamping jaw 2; the above-cited rotary seat 24 can, by a smaller plug post 241, be obliquely inserted into penetration and installation hole 211 of clamping jaw 2 and then rotated to be installed in the arc wall; the upper section of rotary seat 24 also has an arc concave wall in a proper arc and a limit rod to accommodate and position the above-cited various cylindrical movable clamping claws 1; movable clamping claws 1 of this design can, by rotations of rotary seat 24 and rotations of opposite rotary seat 24, form multiple adjustments as desired.
The rotary seat 24 and the rotary slide face of clamping jaw group 2 in the above-cited design has a structure of reverse clamping and side inclinations, therefore, when this structure is used to clamp a work piece, it can achieve tight and firm locking effects; again as to clamping jaw group 2 of this design, the reverse clamping side of its jaw top face declines downward, and rotary seat 24 or movable clamping claws 1 or rotary seat 24 and movable clamping claws 1 are all higher than the opposite coupling body and their higher parts have a larger radius to fully cover slide connection seam between their own body and opposite bodies as shown by the connection part in the related figure to prevent any small residual dedgs left by the work piece from falling into this connection seam and damaging the wall face.
The clamping side of clamping jaw group 2 under the present invention can have a slide seat 201 (as shown in FIGS. 26, 28, 30, 32, 36, 38, 44, 45, 47, 50, 51, 52 and 53) which can be driven sideways in a straight line or arc line, positioned and firmly locked, of which the slide face of slide seat 201 and clamping jaw group 2 has been correspondingly provided with slide guide keyways for coupling, in other words, one has a dove-tail key, while the other has a dove-tail slot as shown in FIGS. 26, 28, 30, and 38, or this can be coupled by rectangular slide slot 202 and rectangular 203 for sliding as shown in FIGS. 32 and 36.
For the above-cited design, the section of slide seat 201 can be in a form of a trapezoid, as shown in FIGS. 32 and 34, clamping jaw 2 can be provided in a form of a wider body in the upper part and smaller body in the lower part or vice versa, rectangular slide slot 202 is cut and provided on its oblique slide face for the perpendicular slide face, thus, looking at the processing plane, this rectangular slide slot 202 is in a inclination status, with respect to rectangular slide key 203 of slide seat 201, the upper wall of this rectangular has insertion and catching function to make slide seat 201 and slide face of clamping jaw 2 keep a close contact status, and make the clamping face of slide seat 201 still maintain in a perpendicular status, and also make its bottom flatly stick to the bottom fixing body; rectangular slide slot 202 can, by a plug or blocking block, coverup its opening and; since rectangular slide key 203 of slide seat 201 is shorter, this makes slide seat 201 have a longer slide scope; when this design clamps a work piece, at one end of the wider clamping jaw, there appears a stronger pushing status, as shown in the upper part in FIG. 32, when a bigger force of the clamping work is applied, the upper end will not slip off the opening and impose firm locking and tightening function to the clamping of a work piece.
As to the slide positioning way of the above-cited slide seat 201, a locking screw can be provided at a proper position on the slide face, after slide seat 201 is positioned, this can, from the body of clamping jaw 2, lock inwardly to tightly press against slide seat 201, or as shown in FIGS. 50 and 51, the guide keys are provided with concave limit slots to limit the penetration of the adjustment screw from the clamping back side.
As shown in FIG. 52, the coupling and driving structure of slide seat 201 and clamping jaw group 2 can be arc slide face with its arc in a proper radius to make slide seat 201 slide sideways to a set arc locus; this design can also be driven in coordination with sideways straight line locus, thus forming a multi-step combination, as shown in FIG. 53, it can have multi-step slide seats 201, whereas a straight line or arc slide face appears between each two adjoining slide seats 201 for micro-adjustments to tightly clamp the work piece.
The clamping face of slide seat 201 can be a plane with press embossed patterns or can be provided with the above-cited positioning seat 21 in order to install various kinds of semi-cylinders or multi-functional movable claws 1, or can also be, as an extension of the above-cited design, the auxiliary block 22 and base seat 23 to install rotatable and movable clamping claws 1, or can be the movable clamping claws rotatable along rectangular coordinates; the top face of this slide seat 201 and the top face of the clamping jaw group 2 that couples with this slide seat 201 can all be in a form of the reverse clamping side inclining downward, and the top face of slide seat 201 has a raised and protruding protective lip to fully cover up the connection seam between the coupling slide vaces to expedite sliding and falling down of the residual dredgs left by the work pieces without falling into the connection seam as shown in FIG. 51; besides, this slide seat 201 can be in a form thinner in its upper part and thicker in its lower part while the fixing seat of clamping jaw 2 is in a form thicker in its upper part and thinner in its lower part and its slide face is an oblique face with firmly locking functions.
Clamping jaw group 2 under the present invention can also coordinate with the needs of the work pieces to make the slide jaw adequately adjust the clamping directions, and its structure is shown in FIG. 54, as socket seat 25 and a protective disc 26 are provided on the back of the slide jaw, the end of the guide screw is a ball-type body which penetrates into protective disc 26; right under the center of the bottom of the slide jaw which matches the socket seat, a ring-and-post support block 27 is provided, this support block 27 of the ring-shaped post is used for sliding in the guide slot on base seat 3; the ring-and-post support block 27 is in a form of cylinder, or the slide jaw can rotate a certain angle along the ring-and-post support block 27 as its rotary axis as shown in FIG. 55, whereas its maximum angle of rotation depends on the allowable scope of movements between the guide screw and protective disc 26, but it is necessary to maintain the initial driving position of the guide screw; by dint of the design of the top-pushing movable jaw of the socket seat 26, the above-cited guide screw can also be in a form that the end of this guide screw has a holding ring 251 to hold a positioning rod 261 which veritcally stands on the back of the jaw body, and its ring-and-post support block 27 is at a position under the same center of the positioning rod 261 as shown in FIGS. 56 and 57.
After the slide jaw of the present invention has been in installed the ring-and-post support block 27, an inward concave angle is cut and provided at the corner between the slide face of the slide jaw and the neck of the slide jaw extending downward, as shown in FIG. 58, the slide face between the bottom of the slide jaw and the jaw base seat, and the corner between the extended neck and guide slot arc most susceptible to damage during the sliding of the slide jaw, therefore the inward concave angle of the present invention make the turning angle b between the slide face of the jaw base seat and the guide slot not subjected to frictions, this there is not worry about any damage resulted.
As shown in FIGS. 59 and 60, there is the slide jaw structure adjustable in multiple clamping directions; on its back, it has the above-cited the pushing structure of socket seat 25, at central position in the bottom face of the jaw, a semi-spherical body with longitudinal slot protrudes upward and has as an appropriate thickness; at its center, a fill-in and installation hole 271 can be drilled downward from the top face of the jaw; the feature of this design lies in that a press post 273 with a ball head protrudes from fill-in and installation holes 227, and that the threaded end of press post 273 protrudes downward from the longitudinal slot and also penetrates through ring-and-post support -lock of neck base 274 installed on the bottom base of the jaw or over the slot, and then press post 273 is firmly locked by the female screw; inner threads are made on the wall of the fill-up and installation hole 274 of the slide jaw to accommodate filling block 272 for locking in and filling up the jaw top to a flat level; the coupling face of the above-cited neck base 274 and the spherical body of the jaw bottom face is a spherical concave seat; the bottom of the above-cited fill-in and installation hole 271 has an arc face with a center same to that of the spherical body, and a longitudinal slot is cut and provided on this arc face; socket seat 25 of the jaw back has a concave spherical arc whose radius is larger than the external radius of the terminal spherer of the guide screw; thus, the slide jaw of this invention can, by the socket seat 25 on its back, drive the plane to rotate a small angle and can also make the slide jaw swing up and down to change the angle of elevation as shown in FIG. 61, to maintain the driving status of the guide screw along a straight line and also to make clamping jaw 2 automatically adjust its direction in order to easily clamp a work piece.
The slide jaw of the above-cited jaw group can be in a multi-directional clamping design, or a slide jaw or fixed jaw with a latitudinal arc slot 204 in a horizontal axially fixed radius as shown in FIGS. 62 and 63; a wider latitudinal dove-tail slot 205 is provided on the arc slide wall face of latitudinal arc slot 204; as the arc of the cross section of latitudinal arc slot 204 is larger than 180°, the opposite slide seat 201 with an arc of its cross section same of that of latitudinal arc slot 204 can be installed in this latitudinal arc slot 204, and the front and (i.e. the clamping side) of slide seat 201 protrudes a protruding structure in an arc smaller than 180° for installing movable clamping claw 1; the opening part of latitudinal arc slot 204 or the round arc seat part of slide seat 201 in this design will not slip off; on the slide face of the said round arc, a dove-tail key 206 narrower in width can be provided, so this dove-tail key 206 can slide up and down in wider sideway dovetail slot 205, thus limiting the allowable angle of elevation of slide seat 201.
Furthermore, when clamping jaw group 2 of the present invention is installed with slide seat 201 or movable clamping claw 1, the under side of its oblique slide face can be provided with a concave form in a proper depth along the inverse clamping side as shown in FIGS. 64 and 65; during clamping a work piece, this makes the bottom of slide seat 201 or movable claw 1 tend to move out further, thus intensifying the tightly clamping force of the upper part against the work piece, and forming much better firmly locking effects.
The servo-clamping device in the present invention can be, according to the actual needs, designed into changeable clamping group 2; as shown in FIG. 66, it can be in a form that plug holes 207 are provided at equal distances between them on the bearing face of the base seat of the jaw, while its clamping jaw 2 is a separate body in a thickness same to that of the base seat of the jaw, and on the bottom of clamping jaw group 2, plug rods 208 are provided and can be selectively plugged into such equal-distant plug holes 207 to become in a readiness status; after plug rod 208 is plugged in, clamping jaw group 2 can be tightly locked up by bolts at the place under the bearing face of the base seat of the jaw. As shown in FIGS. 66 and 68, clamping side of the above-cited separate clamping jaw group 2 can be provided with the above-said various kinds of movable clamping jaws 1, or such separate clamping jaw group 2 do not have any movable clamping jaws 1 at all; the structure of the base seat of the jaws can also have support walls 28; as shown in FIG. 69, the plane support wall 28 can be provided with shorter independent jaws as desired; the bearing face of such support walls 28 can be formed by a formation of several concave arcs in connection; at the center of each concave arc, a plug hole 207 is provided for the insertion and positioning of separate rotary seats 24 and movable clamping claws 1; or as shown in FIGS. 72, 73, 74, and 75, from the center of each of movable clamping claws 1, a plug rod 208 or bolt 209 protrudes downward to be inserted or locking in plug holes 207; or middle adjustment rods 210 which can adjust the positions of height are inserted into plug holes 207; each of such middle adjustment rods may have a plug socket on its upper part and its lower part can plug or screw into plug holes 207 of the bearing face of the jaws; or their bottom part can be connected with bolt 209 or plug rod 208, while their upper part is coupled by an oblique penetration post 211, thus forming a structure of the penetration post 211 rotatable as desired. This penetration post 211 can penetrate and be installed with a single-layer or multi-layer movable clamping claws 1 as shown in FIGS. 75 and 76; the movable clamping claws 1 of this design can directly use the support wall 28 as their bearing force face, and can be, directly by the penetration, installation and locking of the penetration post 211, locked to plug hole 207 on the base seat of the jaw 1 of which if penetration post 211 or plug rod 208, bolt 209, or middle adjustment rod 210 additionally added and tightly locked with a positioning piece, after penetration post 211 or plug rod 208, bolt 209 or middle adjustment rod 210 has penetrated through the base seat of the jaw, the movable clamping claws 1 can be provided on the part of the fixed jaw to get rid of interfering the sliding movement and also to expedite the adjustments of their heights from the bottom.
As shown in FIGS. 77 and 78, this invention can also clamp work pieces in special shapes by the auxiliary blocking block 4 which is positioned on the side of the slide jaw and can also be turned and engaged with the fixed jaw or which is positioned on the side of base seat 3; this makes the work piece positioned by the three-point clamping claws, thus the work piece will not slip off sideways along the pressing direction of movable clamping claws 1 due to the particular shape of the work piece; as shown in FIG. 78, auxiliary blocking block 4 may have an engagement opening to accommodate the fixed jaw and base seat 3 to block the work piece.
The auxiliary blocking block 4 of the above-cited design can also have drivable small blocking blocks 41 as shown in FIGS. 79 and 80, of which these small blocking blocks 41 can be fixed or movable clamping claws 1 in various proper shapes, a bolt-driving structure can stretch out from or retract into the auxiliary blocking block 4, thus making small blocking blocks 41 and auxiliary blocking block 4 form a plane. The driving structure of small blocking blocks 41 of this design can be the same as shown in the drawing that a driving seat is fixedly provided on the external side of auxiliary blocking block 4 to accommodate the penetration and installation of bolts, the end of the bolts is driven by the conventionally used handle, or an electrically power operated driving structure is provided on the driving seat to make small blocking blocks 41 extend a set proper length.
The base seat 3 of the present invention serves a table for the sliding and positioning of integral clamping jaw group 2, and can be a seat body which extends downward and directly from the center of gravity of clamping jaw group 2 and can be firmly locked on or horizontally laid on other work table as shown in FIGS. 1, 44, 45, 47, 48, 49, 60 and 70; this base seat 3 can match the slide bearing face, jaw base seat or drilled holes provided on the fixed jaw, slide jaw or changeable clamping jaw of clamping jaw group 2; or as shown in FIGS. 81 and 82, a mechanical post 31 extends downward from the position of the center of gravity of clamping jaw group 2, the end face on the bottom of this mechanical post 31 is an oblique plane; a positioning post 32 extends from the center of this oblique plane, to plug in table seat 33 of an oblique end face, of which table seat 33 is formed by the upward extention of fixed seat 34; after inserted in table seat 33, the positioning post 32 of this design can be positioned by a press spring or press pin, while fixed seat 34 can be locked on the work table by fixing screws; thus clamping jaw group 2 can be rotated along the oblique coupling face between mechanical post 31 and table seat 33 to adjust the azimuth and clamping direction of the work piece under clamping as desired.
The design of the above-cited base seat 3 which can adjust the position of clamping jaw group 2 can also make base seat 3 have a multi-step mechanical post 32 to couple and connect oblique planes or horizontal planes to serve a design of multi-step adjustments, whereas the rotary and rotational adjustments of various steps can be made by the joint-motion structure of other machineries such as gear drive, in addition to manual power or electrical power driven means to conduct fixed or unfixed rotational as shown in FIG. 82.
The base seat of the servo-clamping device under the present invention can also be firmly installed on the work table (bench) on the floor as shown in FIG. 83, this work table (bench) has a sleeve-on and retractable rod-frame structure, on the top face of the work table (bench), positioning seat 35 and positioning slide seat 36 are provided along the rod-frame, of which positioning seat 25 is horizontally laid on the rod-frame, while positioning slide seat 36 positions with the holding rod frame of the penetration and installation seats on its sides; positioning seat 35 and positioning slide seat 36 are coupled by guide screw and can be driven in opposite directions; positioning seat 35 and positioning slide seat 36 under this design can serve as the base seat of the jaw of clamping jaw group 2, on which opposite latitudinal slots are provided respectively; on such slots, semi-circular connection holes 37 are cut and provided at equal intervals, and in opposite inward or outward or inward of outward directions; such semi-circular connection holes 37 can be used by the movable clamping claws 1 of changeable clamping jaw or separate body of clamping jaw group 2 to make the application of the present invention to clamp work pieces even more flexible. Besides, at the lower side of the above-cited positioning seat 35 and positioning slide seat 36, an article-carrying tray 38 is firmly provided by the rod-frame structure; the position to firmly set up this article-carrying tray 38 is slightly lower than that of the fixed seat of the guide screw to avoid any interference with the driving actions of the guide screw; the main functions of this article-carrying tray is to temporarily set related tools on this tray, when clamping jaw groups 2, movable clamping claws 1 or work pieces.
As shown in FIG. 83-1, outwardly faced connection holes 37 which are inclining inward in their central part are provided on the positioning seat 35 and positioning slide seat 36, such inwardly inclining connection holes 37 make movable clamping claws 1 only eccentrically displace toward the center during their clamping of a work piece and sliding, thus clamping the work piece lighter; if the connection holes 37 are made to incline toward both external sides, when movable clamping claws 1 tightly clamp the work piece, movable clamping claws 1 can only move toward the center, thus tending to exercise pressures toward the center, as shown in FIGS. 83-2 and 83-3, they can have connection holes 37 toward inside and outside which may be provided in an oblique shape and at fixed positions in branch-shaped fork or wave-shaped or pinacle and valley-shaped formation.
When the design of this invention is used to the movable clamping claws 1 on the work table (bench) on the floor can be separately inserted and positioned in connection holes 37, as shown in FIG. 83-4, such movable clamping claws 1 have the clamping sides of the plane and concave and convex arc face, or as shown in FIGS. 83-5 and 83-6, they have eccentric plug rod 208 or bolt 209, their eccentric arc clamping side can be unidirectional or two-directional two-sided formation as shown in FIG. 83-6, they also can have push handle 19 provided at a proper position on movable clamping claws 1 to push movable clamping claws 1, as shown in FIGS. 83-7 and 83-8, when movable clamping claws 1 are clamping a work piece, and after the eccentric movable claws 1 are rotated by the push handle, two opposite clamping faces produce the status of distance reduction, thus clamping the work piece together; if the movable clamping claw 1 on the other side pushes the work piece again, the frictional action between the work piece and the movable clamping claws 1 makes movable clamping claws 1 produce rotations to clamp the work piece together.
The servo-clamping device of the above-cited design can be also used to wood working, whereas in addition to the above-cited forms, its movable clamping claws 1 can be made with wooden materials and their clamping sides can be firmly glued with rubber plate or metal clamping jaw as shown in FIG. 83-9, or can be made with metal materials on which then clamping faces in various forms maybe installed as shown in FIG. 83-10.
Summing up all the above-cited various applicable structures, the servo-clamping device under the present invention, can, according to the characteristics of work pieces at the processing sites, make various clamping jaw groups 2 have a single group or several groups of movable clamping claws as shown in FIGS. 1 to 10, 33 to 49, 52, 53, 84 and 85, and also make movable clamping claws 1 on two sides installed and positioned in staggered positions with counterparts on the opposite sides; this makes movable clamping claws 1 directly clamp a work pieces, or makes compensatory trapezoidal lateral side face clamp smaller and thinner work pieces.
The clamping jaw group 2 under the present invention can also, according to the work characteristics, be installed in more directions and more groups; as shown in FIG. 86, clamping jaw group 2 is a form of triangular positioning according to base seat 3, by which the guide screw pushes and holds clamping jaw group 2 in three directions to clamp a work piece toward the center; the formation of its triangular position can make these three driving directions concentrate at one point, thus also making movable clamping claw 1 with compensatory trapezoidal clamping face being fully capable of clamping very small triangular and round work pieces or work pieces in other shapes, while those which can clamp larger work pieces by their semi-cylindrical movable clamping claw 1 are shown in FIG. 88. The way of the installation of triangular positions to clamp clamping jaw group 2 under this design can also make the driving loci of three groups of clamping jaw group 2 form a triangle in a proper size as shown in FIGS. 87 and 39, and, at the same time, the compensatory clamping face of movable clamping claw 1 may rotate a certain angle to achieve the purpose of reducing the clamping area.
The design of the above-cited driving loci can be expanded to install separate four-point or multi-point, equilateral or unequilateral clamping jaw groups, as shown in FIG. 85 is a four-point unequilateral separate clamping jaw group 21 as shown in FIGS. 90 and 91 are installed in equilateral form, but its driving loci form a properly sized square; if this structure has its movable clamping claws 1 in a semi-cylindrical form, under condition of normal positions, its movable clamping claws 1 can clamp a square in a size smaller to the radius of a movable clamping claw 1 or a clyinder or sphere in an equivalent diameter, and can clamp work pieces in much smaller sizes, after the angle of movable clamping claws 1 is properly adjusted.
The clamping jaw group 2 and movable clamping claw 1 of the servo-clamping device under the present invention can be applicable to conventionally used various clamping devices, or movable mechanical frames, machineries, and arms, and when movable clamping claw 1 clamps a work piece, this device can automatically adjust its angles according to the configuration of the work pieces to naturally form the best tightening status during tightly clamping a work piece. | An integral workbench having a table top formed as an integral vise including integral vise jaws and clamping elements which are longitudinally and angularly adjustable to vary the angle of clamping and selectively adjustable to vary the shape of the clamping surface. Either vise jaw has a pair of spaced apart openings formed therein longitudinally thereof and the other vise jaw has one such opening formed therein. Each opening has a substantially straight edge portion and a plurality of longitudinally-spaced cut-outs formed therein opposite to the straight edge portion. A clamping element is associated with each opening such that at least three clamping elements are provided. Each clamping element has a top portion that rests on the jaw and a shank portion that extends through the opening and is adapted to be selectively received within one of the cut-outs, providing longitudinal adjustability. The elements may rotate about the axis of the shank, providing angular adjustability. The top portion of each clamping element has at least one arcuate and at least one straight edge clamping surface formed thereon. By rotation of the element about their axis, the clamping surfaces may be adapted to be selectively clamped against the workpiece so that the shape of the clamping surface may be varied to conform with the shape of the surface of the workpiece to be clamped. | 1 |
[0001] This is a continuation application of copending prior application Ser. No. 09/995,379, filed on Nov. 26, 2001, which is a continuation application of prior application Ser. No. 09/461,936, filed on Dec. 15, 1999, now issued as U.S. Pat. No. 6,351,892 on Mar. 5, 2002, the disclosures of which are incorporated herein by reference.
BACKGROUND OF THE INVENTION
[0002] The present invention relates generally to the field of orientation sensors and, more particularly, to an orientation sensor including a conductive pattern including isolated conductive segments configured for segment to segment (hereinafter intra-pattern) property measurements useful in establishing one or more orientation parameters. The sensor is suitable for use in applications such as, for example, monitoring a remotely controlled underground boring device.
[0003] A number of orientation sensors have been designed especially for use in remote controlled underground boring devices. As will be seen, these prior art devices have shared a basic design concept.
[0004] One example of a prior art orientation sensor in the form of a roll sensor is disclosed in U.S. Pat. No. 5,174,033 (Rider). FIGS. 1 and 2 are partial reproductions of FIGS. 4 and 5, respectively, of the Rider patent. FIG. 1 shows a roll sensor generally indicated by the reference number 10 . Sensor 10 includes a substrate 12 and a cup-shaped member 14 which is sealed to substrate 12 by an O-ring 16 in a way which defines a cavity 18 . A conductive fluid 20 is contained by cavity 18 .
[0005] Attention is now directed to FIG. 2 in conjunction with FIG. 1. FIG. 2 illustrates a plurality of capacitor electrode plates 22 which are formed on the inner surface of substrate 12 . Electrical connections to capacitor electrode plates 22 are accomplished via a plurality of electrically conductive leads 24 . Cup-shaped member 14 serves as a grounded electrode common to all of electrode plates 22 . During operation, roll sensor 10 is designed to spin in the plane of FIG. 2, oriented such that gravity causes fluid 20 to continuously flow into the bottom portion of the cavity (FIG. 1). The roll orientation of sensor 10 is determined by measuring the capacitance between individual electrode plates 22 and cup-shaped member 14 as influenced by fluid 20 . It is important to note that measurements are taken, in essence, between the ends of the device. Moreover, it is submitted that prior art orientation sensors, in general, operate under the concept of using measurements taken along the length of the device. That is, by using electrically conductive members positioned at least at the ends of the device and/or centered therebetween or at other intermediate locations. For other examples, see U.S. Pat. Nos. 4,674,579, 4,714,118 and 5,726,359. As will be seen, the present invention eliminates the need for an implementation having electrodes at both ends of a device or spaced apart therebetween, introducing a highly advantageous and heretofore unseen configuration useful in measuring pitch and/or roll.
SUMMARY OF THE INVENTION
[0006] As will be described in more detail hereinafter, there is disclosed herein an orientation sensor capable of generating at least one output signal indicative of a particular orientation parameter. The orientation sensor comprises a sensor housing defining a closed internal chamber including a first internal surface. The first internal surface supports a first electrically conductive pattern which itself forms part of a sensing arrangement. The first electrically conductive pattern includes an arrangement of electrically isolated segments in a predetermined configuration. A flowable material is contained within the internal chamber, which flowable material contacts a portion of the first internal surface dependent upon the value of the particular orientation parameter.
[0007] In one aspect of the invention, an electrical property is measurable between the segments such that the orientation parameter can be determined using the output signal based only on the electrical property and, therefore, only on the portion of the first internal surface contacted by the flowable material. Thus, intra-pattern measurements yield the measured property without the need for conductive members distributed along the length of the chamber.
[0008] In another aspect of the invention, the particular orientation parameter is pitch. In this instance, a first electrically conductive pattern includes first and second electrically isolated segments defining a gap therebetween on the first internal surface such that the value of the electrical property is in proportion to an area of the gap covered by the flowable material between the first and second segments which, in turn, is in proportion to the pitch so as to cause the value of the electrical property between the first and second segments to change in response to changes in pitch.
[0009] In still another aspect of the invention, the particular orientation parameter is roll angle. In this instance, the first electrically conductive pattern includes at least first and second electrically isolated segments defining a first roll sensing gap therebetween on the first internal surface such that the value of the electrical property is in proportion to an area of the roll sensing gap covered by the flowable material between the first and second segments which, in turn, is in proportion to the roll so as to cause the value of the electrical property between the first and second segments to change in response to changes in roll. In one feature, the electrically conductive pattern defines a plurality of roll sensing gaps, each of which covers a particular range of roll positions of the orientation sensor. In one preferred embodiment, the electrically conductive pattern defines three roll sensing gaps that are configured so as to substantially surround a common center point about which the orientation sensor experiences roll. Each roll sensing gap is used to produce an output such that the roll position of the orientation sensor is unambiguously identifiable either statically or dynamically.
[0010] In yet another aspect of the present invention, an orientation sensor is provided which is capable of generating at least two output signals indicative of a particular orientation parameter. The orientation sensor comprises a sensor housing defining a closed internal chamber having first and second opposing internal surfaces. A first electrically conductive pattern is supported by the first internal surface and a second electrically conductive pattern is supported by the second internal surface. The first electrically conductive pattern includes a first plurality of electrically isolated segments in a first predetermined configuration while the second electrically conductive pattern includes a second plurality of electrically isolated segments in a second predetermined configuration. A flowable material is contained within the internal chamber such that the flowable material contacts first and second portions, respectively, of the first and second internal surfaces. The respective areas of the first and second portions contacted by the flowable material are dependent upon the value of the particular orientation parameter in a way which influences an electrical property measurable between the segments disposed on the first and second surfaces such that the first electrically conductive pattern produces at least a first output signal and the second electrically conductive pattern produces at least a second output signal. In one feature of the present invention, each pattern produces its output signal substantially independent of the other pattern based on contact with the flowable material.
[0011] In another feature of the present invention, the first and second electrically conductive patterns are identical and identically oriented such that combined use of the output signals to determine the value of the orientation parameter produces ratiometric cancellation of temperature error.
[0012] In one implementation according to the present invention, a combination pitch and roll orientation sensor is provided having a housing containing a flowable material which flows in the housing in response to the pitch and roll orientation of the housing. An electrical arrangement includes a single electrically conductive pattern cooperating with the flowable material so as to produce independent electrical signals corresponding to the pitch and roll of the housing.
BRIEF DESCRIPTION OF THE DRAWINGS
[0013] The present invention may be understood by reference to the following detailed description taken in conjunction with the drawings briefly described below.
[0014] [0014]FIGS. 1 and 2 are prior art figures taken directly from U.S. Pat. No. 5,174,033 for use in conjunction with the discussion of the prior art appearing above.
[0015] [0015]FIG. 3 is a diagrammatic side view of an orientation sensor manufactured in accordance with the present invention, shown here to illustrate general aspects of its highly advantageous structure.
[0016] [0016]FIG. 4 is a diagrammatic illustration of one of two identical printed circuit boards used in the orientation sensor of FIG. 3, shown here to illustrate the overall outline of the boards in conjunction with a highly advantageous electrically conductive sensing pattern that is defined on the depicted side of each board.
[0017] [0017]FIG. 5 is a diagrammatic illustration showing an electrically conductive pattern formed on the side of the printed circuit boards opposing the side depicted in FIG. 4.
[0018] [0018]FIG. 6 is a diagrammatic/schematic illustration showing one highly advantageous manner of electrically interconnecting the printed circuit boards of the orientation sensor of FIG. 3 for purposes of measuring pitch orientation.
[0019] [0019]FIG. 7 is a diagrammatic/schematic illustration showing one highly advantageous manner of electrically interfacing with the printed circuit boards of the orientation sensor of FIG. 3 for purposes of measuring roll orientation, which simultaneously permits the use of the pitch measurement scheme shown in FIG. 6.
[0020] [0020]FIG. 8 is a plot illustrating normalized roll output signals from the orientation sensor and associated circuitry of FIG. 7.
DETAILED DESCRIPTION OF THE INVENTION
[0021] Having described FIGS. 1 and 2 previously, attention is immediately directed to FIG. 3 which illustrates an orientation sensor manufactured in accordance with the present invention and generally indicated by the reference numeral 100 . It is noted that dimensions in FIG. 3 have been exaggerated for illustrative purposes. Sensor 100 is made up of first and second printed circuit boards 102 a and 102 b , respectively. A cylindrical tube 106 includes openings which are sealed to the inner facing surfaces 108 a and 108 b of each of the printed circuit boards so as to define a cavity 110 . Tube 106 may be formed, for example, from quartz or from other such suitable materials. In this preferred embodiment, printed circuit boards 102 a and 102 b are identical to one another, as well as being identically oriented at either end of tube 106 . It is to be understood, however, that an effective orientation sensor may be produced using only one of these printed circuit boards by sealing off tube 106 , for example, at the location of a dashed line 112 , which is described in further detail below.
[0022] Attention is now directed to FIGS. 3 and 4. The latter figure illustrates a printed circuit board pattern 114 that is formed on inner sides 108 a and 108 b of each of printed circuit boards 102 a and 102 b . The overall outline of the printed circuit boards is a “tombstone” configuration, however, it should be appreciated that any suitable outline may be used so long as measurements can be obtained in accordance with the teachings herein. Pattern 114 defines a highly advantageous configuration made up of individual, electrically isolated segments including one combination of segments for sensing pitch and another combination of segments for sensing roll. Specifically, a first segment 120 and a second segment 122 comprise a pitch sensing arrangement defining a pitch sensing gap 124 . The first segment comprises a circular shape with its center located at center point 128 . Alternatively, segment 120 could comprise a ring shape or other such suitable form. Second segment 122 comprises a ring shape which is likewise centered on center point 128 such that its innermost edge is equidistant from the edge of segment 120 about its periphery. During operation, orientation sensor 100 is designed to be mounted, for example, in the drill head of a boring tool such that roll takes place about an axis 126 (FIG. 3) which passes through the center point 128 (FIG. 4) of each of printed circuit boards 102 a and 102 b . Pitch, on the other hand, is measured in terms of the angle φ, as indicated in FIG. 3, wherein an arrow 130 represents a horizontal orientation.
[0023] Still referring to FIGS. 3 and 4, the roll sensing combination of segments comprises segment 122 along with segments 132 a - c so as to define first, second and third roll sensing gaps 134 a - c , respectively, which serve to surround center point 128 . Each of segments 132 a - c is spaced uniformly apart from segment 122 by virtue of an appropriate radius centered upon center point 128 . Therefore, each roll sensing gap covers an arc of somewhat less than 120° and is arcuate in form having a constant width. External connections are made via connection pads 136 a - c wherein pads 136 a - c are connected to roll sensing segments 132 a - c while pad 137 is connected to segment 122 . The connection pads are electrically connected with their associated segments by appropriately configured traces. For purposes of clarity, the traces are identified using the appropriate connection pad reference number. It is noted that segment 122 includes projections 138 a and 138 b . These projections serve to equalize roll signals obtained from the different roll sensing segments by approximating that portion of trace 137 which extends between roll sensing segments 132 b and 132 c.
[0024] Attention is now directed to FIGS. 3 - 5 . FIG. 5 illustrates an electrically conductive pattern 140 formed on outer sides 142 a and 142 b of printed circuit boards 102 a and 102 b , respectively. A feed-through 144 defining a through-hole is positioned encompassing center point 128 whereby to electrically connect a trace 146 and associated connection pad with segment 120 of pattern 114 on the opposite side of the printed circuit board. Connection pad 146 is arranged so as to be positioned laterally between connection pads 136 a and 136 c of pattern 114 (comparing FIGS. 4 and 5) for purposes of maintaining signal isolation between segment 120 and the various other segments. This purpose is also furthered by a ground segment 148 which covers essentially all of outer sides 142 , but for trace/pad 146 and a space 150 defined between ground segment 148 and trace/pad 146 . It is noted that patterns 114 and 140 may be modified in any suitable manner in accordance with the present invention. For example, in pattern 114 , roll sensing segments 132 a - c may be positioned (not shown) within the interior of segment 122 while segment 120 may surround (not shown) the outer periphery of segment 122 .
[0025] Still referring to FIGS. 3 - 5 , chamber 106 is partially filled with a flowable material such as, for example, a suitable conductive fluid 152 which is selected to function in the manner to be described. The fluid may readily be injected, for example, into chamber 106 through feed-through 144 of printed circuit board 102 a while air is allowed to escape from the feed-through of printed circuit board 102 b . Thereafter, the feed-throughs may be sealed using any suitable material such as, for example, silicone sealant. One useful conductive fluid has been found to be glycerin with a small quantity of saline solution added to provide for conductivity, as described in U.S. Pat. Nos. 5,155,442, 5,337,002, 5,444,382 and 5,726,359 which are incorporated herein by reference. In order to function in the manner intended, and at the same time, optimize contact with patterns 114 on surfaces 108 a and 108 b , chamber 106 is filled with conductive fluid 152 to a predetermined level. As will be seen, the predetermined fluid level should be selected in view of several considerations with regard to establishing an operational range of orientations to be detected. Thus, conductivity, as measured between any pair of segments defining a sensing gap, will vary based upon the portion of the sensing gap in direct contact with the conductive fluid. It is important to understand that flowable materials that enable measurement of electrical characteristics other than conductivity (such as capacitance and inductance) may also be used in chamber 110 . For instance, materials having dielectric characteristics are well suited wherein capacitance measured between the segments of electrically conductive pattern 114 varies in accordance with the portion of the fluid contacting the respective sensing gap. One example of a material having such dielectric characteristics is liquid silicone.
[0026] Having generally described the structure of orientation sensor 100 , the pitch aspect of its operation will be described with reference to FIGS. 3 and 6. For any particular pitch orientation within a predetermined operational range, some portion of each pitch sensing gap 124 will be contacted by conductive fluid 152 . FIG. 6 diagrammatically illustrates printed circuit boards 102 a and 102 b along with external electrical connections in a configuration for purposes of sensing pitch. The illustrated pitch measurement configuration utilizes a voltage source 160 having a positive (+) terminal electrically connected to connection pad 137 of printed circuit board 102 b and a negative terminal (−) connected to pad 137 of printed circuit board 102 a . For purposes of illustrations only this is shown as a direct current source. In actual practice, the source would be alternating in order to avoid electrolytic damage to the conductive fluid 152 and/or other parts of the orientation sensor 100 . Connection pads 146 of printed circuit boards 102 a and 102 b are electrically connected with one another and a pitch output 162 is taken from this connection. The variable resistivities between segments 120 and 122 of printed circuit boards 102 a and 102 b caused by contact of conductive fluid 152 with pitch sensing gaps 124 of the respective printed circuit boards are illustrated by equivalent variable resistors ER 164 and ER 166 . It is to be understood that these equivalent variable resistors each represent a lumped resistance corresponding to the actual, distributed resistance produced by the corresponding pitch sensing gap in contact with conductive fluid 152 . Thus, in operation, the sensor illustrated in FIG. 6 functions as equivalent variable resistors ER 164 and ER 166 connected in series with one another across voltage source 160 .
[0027] Continuing to refer to FIGS. 3 - 5 , it should be appreciated that the illustrated pitch sensing arrangement is highly advantageous. Specifically, orientation sensor 100 is configured for roll about axis 126 . Segments 120 and 122 of each printed circuit board, therefore, define pitch sensing gap 124 in such a way that the gap surrounds center point 128 . Additionally, pitch sensing gap 124 is circular in configuration and centered on center point 128 so that contact of the pitch sensing gap with conductive fluid 152 is constant irrespective of roll about axis 126 (assuming the proper characteristics of fluid 152 , as described above). Therefore, printed circuit boards 102 a and 102 b provide a constant pitch output signal for a fixed pitch orientation, which output signal is independent of roll. It should be appreciated that the pitch sensing gap may be configured depending on the specific intended application. For example, in a pitch sensor which is not subjected to roll, in normal use the pitch sensing gap may be defined as a “stripe” having a vertical component of orientation. Any configuration of pitch sensing gap is suitable in this regard so long as the area of the gap contacted by conductive fluid 152 is proportional to pitch orientation.
[0028] Still considering the pitch orientation measurement configuration illustrated in FIG. 6, it is important to understand that each printed circuit board produces a pitch signal independent of the other board. That is, each board measures pitch based solely on the resistivity present between segments 120 and 122 of pattern 114 . In essence, the measurements are taken in the plane of each printed circuit pattern. Therefore, as mentioned previously, only one of printed circuit boards 102 a and 102 b is necessary for producing a pitch measurement. Applicants submit that such a configuration has not been seen in the prior art. Accordingly, an effective pitch sensor may be implemented by closing chamber 110 at aforementioned line 112 such that the chamber is defined between this line and printed circuit board 102 a . The concept of independently produced measurements provides significant advantages over the prior art for reasons to be described.
[0029] As discussed above, prior art orientation sensors require electrodes that are positioned at opposing ends of a chamber (see FIGS. 1 and 2) and possibly centered or at other intermediate positions between the ends of the chamber (not shown). Accordingly, such prior art arrangements measure the electrical property of interest as distributed along the length of the chamber. The entirety of the chamber is thus involved in obtaining the desired measurement. In contrast, because the electrically conductive pattern of the present invention independently produces its measurement, the entirety of the flowable medium chamber is not involved in generating the desired orientation signal. That is, measurements are localized at each printed circuit board. In and by itself, it is submitted that this feature provides a heretofore unseen opportunity for improvement in the accuracy of an orientation sensor using a single flowable medium chamber. The significance of such independent readings will be described immediately hereinafter.
[0030] Referring again to FIGS. 3 - 5 , it should be appreciated that the electrical interconnection of printed circuit boards 102 a and 102 b in FIG. 6 utilizes the independently produced pitch signal of each board in a highly advantageous way. Specifically, as noted above, equivalent resistance 164 of circuit board 102 a and equivalent resistance 166 of circuit board 102 b are connected in series across voltage source 160 with pitch output 162 being taken at the common connection between the equivalent resistances. It should also be appreciated that measurements taken from each of the printed circuit boards are affected as a result of changes in conductivity of electrically conductive fluid 152 resulting from temperature changes. If only one printed circuit board were used, such temperature effects should be given consideration. However, in the circuit of FIG. 6, temperature equally affects the pitch signal produced by each printed circuit board. Therefore, as a result of the series connection of equivalent resistances 164 and 166 , the temperature produced resistance changes are seen to essentially cancel one another. No provision other than the use of the illustrated interconnection is required in order to realize this advantage. Therefore, in accordance with the present invention, this configuration is substantially immune to temperature induced error. It should be appreciated that the described temperature cancellation effects are ratiometric in nature and are not limited to this specific configuration. That is, ratiometric cancellation will be exhibited whenever a ratio is taken between measurements produced by the printed circuit boards 102 a and 102 b at either end of the orientation sensor.
[0031] Although the pitch measurements produced by printed circuit boards 102 a and 102 b are independent of each other, it should be appreciated that, for any particular pitch angle, the different portions of each printed circuit pattern contacted by conductive fluid 152 are, in fact, interdependent. For this reason, pitch output 162 is unique for any particular pitch orientation within a specified operational range of pitch angles. Specific details will be provided for establishing a particular operational range at an appropriate point below. It should be noted that the sensitivity of the orientation sensor is proportional to the length of tube 106 (FIG. 3).
[0032] Attention is now directed to FIG. 7 in conjunction with FIGS. 3 - 5 . FIG. 7 diagrammatically illustrates orientation sensor 100 including external electrical connections made to printed circuit boards 102 a and 102 b for use in sensing roll orientation. As mentioned previously, roll orientation sensing is accomplished using a particular combination of segments including segments 132 a - c and segment 122 , all of which cooperatively define roll sensing gaps 134 a - c . The external circuitry configuration of FIG. 7 may be used simultaneously with the pitch sensing configuration of FIG. 6 such that each of printed circuit boards 102 a and 102 b independently produces a pitch signal, but also independently produces roll signals. To this end, voltage source 160 is applied to connection pad 137 of each printed circuit board 102 a and 102 b , as originally shown in FIG. 6 so as to apply voltage to segment 122 of each printed circuit board 102 a and 102 b . Each one of connection pads 136 a - c for each printed circuit board 102 a and 102 b is connected to a circuit ground 170 through one of a plurality of resistors indicated by the reference numbers R 172 a - f , all of which have the same value. Equivalent resistances of roll sensing gaps 134 a - c for printed circuit board 102 a are indicated by the reference numbers ER 174 , ER 176 and ER 178 , respectively, while equivalent resistances of roll sensing gaps 134 a - c for printed circuit board 102 b are indicated by the reference numbers ER 180 , ER 182 and ER 184 , respectively. Once again, it is to be understood that each of these equivalent variable resistors represents a lumped resistance corresponding to the actual, distributed resistance produced by the corresponding roll sensing gap in contact with conductive fluid 152 . Therefore, a voltage divider is formed for each roll sensing gap comprising the resistance of the pitch sensing gap in series with one of resistors R 172 . Six roll outputs are indicated as ROLL a-f . For example, roll sensing gap 134 a of printed circuit board 102 a , having an equivalent resistance represented by ER 174 , is in series with resistor R 172 a . The corresponding roll output, ROLL a , is taken from the connection of R 172 a and connection pad 136 a.
[0033] Attention is now directed to FIGS. 7 and 8. FIG. 8 illustrates output signals ROLL a-c for counterclockwise roll in the direction indicated by an arrow 190 . For purposes of clarity, output signals ROLL d-f (independently produced by printed circuit board 102 b ) have not been illustrated. The specific position of printed circuit boards 102 a and 102 b in FIG. 7 correspond to the roll position of 0° in FIG. 8. Chamber 106 and the level of fluid 152 are also diagrammatically shown between the two printed circuit boards. In the position shown in FIG. 7, roll sensing gap 134 c is completely immersed in fluid 152 . Roll sensing gap 134 a is partially immersed in the fluid and is being further immersed by continuing rotation. Therefore, ROLL a exhibits a positive slope at the 0° roll position. Roll sensing gap 134 b is also partially immersed in fluid, but is emerging from the fluid with rotation such that ROLL b exhibits a negative slope at the 0° roll position. It is apparent from FIG. 8 that the combination of these three roll signals unambiguously identifies the roll position of orientation sensor 100 for any particular roll orientation under both static and dynamic conditions. Moreover, the roll output waveforms of FIG. 8 contemplate the level of fluid 152 as being above center point 128 of printed circuit board 102 a since positive plateaus 192 of the roll signal waveforms are longer in duration than negative plateaus 194 . That is, the orientation sensor is pitched such that the roll sensing gaps are completely immersed in fluid 152 over an arc that is longer than the arc over which the roll sensing gaps are completely out of contact with the fluid. This condition may be caused, for example, by a pitch, φ, of approximately −10% grade as indicated by fluid 152 which causes a greater proportion of fluid to contact printed circuit board 102 a compared with the portion contacting printed circuit board 102 b . The usefulness of roll signals from the second printed circuit board will be described immediately below.
[0034] Referring to FIGS. 3 and 4, the operational range of orientations over which orientation sensor 100 is useful depends upon a number of different factors including the level of fluid 152 , the length, L, of chamber 110 (tube 106 ), the diameter of tube 106 and the widths of the various pitch and roll sensing gaps. In this regard, the overall combination of these factors cooperate interactively to establish the operational range of the sensor. An orientation sensor has been produced in accordance with this disclosure for use in a horizontal directional drilling application anticipating an operational pitch range of approximately ±100% grade. Specific dimensions of this working embodiment include tube 106 having a length, L, of approximately 0.188 inches and an inside diameter of approximately 0.375 inches. Pitch sensing gap 124 includes inner and outer diameters of approximately 0.195 inches and 0.234 inches, respectively. Roll sensing gaps 134 a - c include inner and outer diameters of approximately 0.275 inches and 0.313 inches, respectively. These dimensions may be modified in any suitable way depending upon a specific application. For example, L may be increased so as to increase the pitch sensitivity of the orientation sensor. Likewise, pitch sensitivity is increased by lowering the relative level of fluid 152 . However, the effect of any modification should be considered with regard to other factors. For instance, if L is inordinately increased, the range over which fluid 152 contacts both printed circuit boards 102 a and 102 b will be decreased. The net result, at high pitch, may be one printed circuit board completely covered by fluid 152 while the opposing board makes no contact with fluid 152 .
[0035] It should be appreciated that the roll output signals of printed circuit board 102 b will essentially be identical to those obtained from printed circuit board 102 a when pitch angle φ is equal to zero. In instances where φ is not equal to zero, the output signals obtained from one printed circuit board will vary from those of the other printed circuit board dependent upon the specific value of φ. Because the rotational motion of inner sides 108 a and 108 b of printed circuit boards 102 a and 102 b relative to axis 126 is opposite to one another, ROLL a of printed circuit board 102 a corresponds to ROLL b of printed circuit board 102 b while ROLL b of printed circuit board 102 a corresponds to ROLL a of printed circuit board 102 b . While both printed circuit boards 102 a and 102 b independently produce roll signals, the overall accuracy of orientation sensor 100 can be improved even further by utilizing the roll signals available from both printed circuit boards. For example, all six of the roll signals may be converted to digital signals using an analog to digital converter (not shown),provided to a microprocessor (not shown), and thereafter provided to a suitable arrangement, such as a display (not shown) for calculation and display of the roll position of the orientation sensor.
[0036] The roll sensing configuration disclosed in FIG. 7 herein may be modified in an unlimited number of ways according to the present invention. For example, any number of two or more roll sensing gaps may be utilized. In the instance where only roll is dynamically measured, as little as a single roll sensing gap is useful. For example, a roll sensing gap (not shown) may be configured including a varying, known width which surrounds the center of rotation of roll of the orientation sensor. Dynamic analysis of the output from such a sensing gap can be used to uniquely identify any particular roll position. In this regard, any combination or configuration of the roll sensing gaps which uniquely identifies roll position of the orientation sensor is useful whether operable in static or dynamic conditions. Another possible modification resides in providing printed circuit boards having sensing gaps of different configurations (not shown) at either end of chamber 106 or, alternatively, identical patterns offset with respect to one another may be provided at either end of chamber 110 . In this way, two roll sensing gaps may be used to uniquely identify the static roll position of orientation sensor 100 .
[0037] Because the orientation sensor disclosed herein may be provided in a variety of different configurations and modified in an unlimited number of different ways, it should be understood that the present invention may be embodied in many other specific forms without departing from the spirit or scope of the invention. For example, electrically conductive patterns may be provided in forms other than as electrically conductive traces on a printed circuit board. In one such alternative, relatively rigid grid wires (not shown) may be used wherein the flowable medium may flow around and between the grid wires. Therefore, the present examples and methods are to be considered as illustrative and not restrictive, and the invention is not to be limited to the details given herein, but may be modified within the scope of the appended claims. | An orientation sensor capable of generating at least one output signal indicative of a particular orientation parameter is described. The orientation sensor comprises a sensor housing defining a closed internal chamber including a first internal surface. The first internal surface supports a first electrically conductive pattern which itself forms part of a sensing arrangement. The first electrically conductive pattern includes an arrangement of electrically isolated segments in a predetermined configuration. A flowable material is contained within the internal chamber, which flowable material contacts a portion of the first internal surface dependent upon the value of the particular orientation parameter. An electrical property is measurable between the segments such that the orientation parameter can be determined using the output signal based only on the electrical property and, therefore, only on the portion of the first internal surface contacted by the flowable material. Thus, intra-pattern measurements yield the measured property without the need for conductive members distributed along the length of the chamber. A combination pitch/roll sensor is described in which a single electrically conductive pattern cooperates with the flowable material so as to produce independent electrical signals corresponding to the pitch and roll of the housing. In one aspect, first and second electrically conductive patterns are provided at opposing ends of a flowable material chamber. Use of signals from the patterns results in ratiometric cancellation of temperature error. | 6 |
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention generally relates to treating patients for health issues, and more specifically relates to systems, devices and methods that use muscle response testing and multi-polar magnetic devices for treating patients for health issues.
[0003] 2. Description of the Related Art
[0004] For centuries, particular locations on the body, referred to as acupuncture or acupressure points, have been used to aid the body in healing. Each of the points on a human body correlates to a particular electromagnetic line, meridian or “flow” that runs through the body. Hieroglyphics and pictographs from the Shang Dynasty, circa 1600-1100 B.C., suggest that acupuncture was in use during that time period. Chinese documents from the beginning of the first century contain the earliest written record of acupuncture points.
[0005] The mummified remains of Otzi, an iceman estimated to be 5,300 years old, had tattoos on various locations of his body that correlate to acupuncture and meridian points. DNA evidence suggests that Otzi had genetic markers associated with reduced fertility. It was also found that Otzi had whipworm, an intestinal parasite, which would have caused him to have abdominal complaints. Otzi was also found to be suffering from arthritis. Among the tattoos found on his body, the tattoo behind his left knee is the location used today for individuals suffering from abdominal complaints, reproductive organ complaints, and vertigo, to name a few. The tattoo located on the inside of his ankle is used for improving digestion. In addition, his fingernails indicated that he had been sick three times in the six months prior to his death (cause of death was a wound), the last time lasting about two weeks. One of the tattoos is at an area of rejuvenation for the body. The placement of tattoos on Otzi's body fits his scientifically discovered medical history perfectly, and in fact, if Otzi went to a practitioner today, there is a good chance that those very same acupuncture points would be chosen to treat his ailments.
[0006] The use of acupuncture and acupressure has a more recent history as well. In 1683, a Dutch physician named Willem Ten Rhijne studied acupuncture for two years in Japan, and he mentioned it in an essay he wrote in a medical text on arthritis.
[0007] In 1943, Dr. Reinhold Voll, a medical doctor in Germany, was diagnosed with bladder cancer. Western medicine provided him with no hope of a cure so he tried acupuncture and was able to completely heal himself. This experience started his quest to learn more about acupuncture. During his studies of acupuncture, he learned that the points used on the body for acupuncture were in fact more conductive of electricity than the tissue surrounding it. From this discovery he was able to develop the EAV Device (Electromagnetic Acupuncture according to Voll), which is a diagnostic machine that is still widely used today. It is believed that the extra conductivity at or around the acupuncture points is what makes the placement of therapeutic devices at these locations so effective in the treatment of health issues.
[0008] Today, acupuncture and other healing arts, such as Jin Shin Jyutsu®, are widely accepted. Medical acupuncture is taught in Harvard Medical School and the Helms Medical Institute, as well as at other well-respected medical schools. Acupuncture, Jin Shin Jyutsu, as well as other similar therapeutic techniques based on traditional Chinese medicine (TCM) have been implemented in many hospitals to help with pain and healing. Although not always fully understood in the West, the value of these ancient healing arts is finally being appreciated by Western medicine.
[0009] Magnetism has been used for centuries for healing health complaints, and is possibly even older than acupuncture. Magnetic energy influences every cell in the body. If the cells become depolarized, it has been observed that an individual will tire. Thousands of years ago, the Eastern belief was that the life force or Chi is generated by the Earth's magnetic field. Its use is recorded in ancient Egyptian writings and it is known that Cleopatra wore magnetic jewelry (i.e., a lodestone) on her head in the belief that it would help her maintain a youthful appearance.
[0010] The existence of electromagnetic energy and its effect on the human body is being studied more and more in Western medicine. Many prestigious institutions have made it a focal point of clinical trials with such research being conducted at Harvard Medical School, Vanderbilt University Medical Center, and the University of Texas Medical Branch. Today magnetic therapies are accepted and used in many countries.
[0011] In 1964, Dr. George J. Goodheart, a doctor of chiropractic medicine, realized that basic chiropractic adjustments were not providing complete and long-term relief for patients' physical complaints. In response, Dr. Goodheart combined the knowledge of those before him with his own experiences involving the muscles of the body in relation to acupuncture therapy to create Applied Kinesiology, a unique method of balancing the electromagnetic lines or flows that run throughout the body. Applied Kinesiology describes a branch of holistic medicine that studies the relationship between muscle movement and the health of the human body.
[0012] He achieved significant results using his new methods and found a very important and specific relationship between the muscles and the rest of the body. He later discovered a diagnostic and treatment tool that he called therapy localization. He observed that if a patient touched a part of the body where there was a problem or “blockage,” a weak muscle would become strong. From that observation, Dr. Goodheart realized he could use a muscle that was strong and go to various points on the body to detect a reflex or organ that created weakness. This weakness would show up in the muscle that was being tested. In this way problem areas could be identified and solutions could be found. For example, he discovered that if an individual was exposed to supplements that could help a patient, that the physical exposure of the individual to the correct supplement would make a weak muscle strong again.
[0013] There are many references that describe the underlying principals of Applied Kinesiology including “Applied Kinesiology,” written by Tom and Carole Valentine of Rochester, VT (1985); “Your Body Doesn't Lie,” written by John Diamond of New York, NY (1980); and “Thorsons Introductory Guide to Kinesiology—Touch for Health,” written by Maggie La Tourelle and Anthea Courtenay of London, England (1992).
[0014] Building upon the efforts of Dr. Goodheart and Applied Kinesiology, there is a growing body of medical evidence that indicates that many health issues, whether physical, mental or emotional, are rooted in the electromagnetic lines or flows of the body. Different flows feed different sections of the body and a disruption in the flow will cause various health issues. The electromagnetic lines, also referred to as meridians, work in the body in a similar way as the electrical wiring in a house. When a circuit breaker “blows,” a section of the house fed by that current line loses power. It has long been observed that the removal of “blockages” of the meridian lines will restore good health. Different means have been used to stimulate these lines such as sharp stones, bone needles, and eventually metal needles, as well as hand techniques. Other methods used to “open” the blockages in electromagnetic lines include taping stationary magnets to a patient, magnetic beds, foot pads, plasters, etc, as well as various other types of machines.
[0015] Muscle response testing is a diagnostic methodology that uses the principals of Applied Kinesiology for determining a body's needs. Muscle response testing (MRT) is used widely by medical doctors, acupuncturists, chiropractors, osteopaths, veterinarians, and holistic dentists. There have been a number of books written on MRT including a seminal work written by Dr. David R. Hawkins in 1995.
[0016] During MRT, medical personnel will push down on a patient's extended arm while the patient resists the downward pressure. If the patient's nervous system is irritated for a period of time, a temporary short circuit will arise in the nervous system causing the arm being tested to momentarily weaken. During testing, medical personnel will irritate the nervous system by touching a sensitive area of the body, an acupuncture point or even by generating uncomfortable or irritating thoughts. Medical personnel may also ask a series of “yes/no” questions of the nervous system, looking for a weak or a strong response of the patient's extended arm. The weak or strong response reveals information about troubled areas in the body and provides additional information to medical personnel on how to treat the troubled areas.
[0017] MRT is used for virtually any question that can be asked of the body to make determinations about physiology, skeletal trauma, allergies, nutritional imbalances, emotional states or anything that may affect the body or the mind. MRT is a diagnostic tool that is only limited to the creativity of the practitioner's ability to ask a proper question. Once the information is ascertained, muscle testing may then be used to find out what the body or mind will respond to in terms of a resolution to the problem. Another benefit of MRT is that many of the problems that may be detected using MRT cannot be detected using conventional lab and exam tests and thus, are not discoverable except when using MRT.
[0018] There have been many efforts directed to using muscle response testing and applied kinesiology techniques. For example, U.S. Pat. No. 5,188,107 discloses a bi-digital O-ring test for imaging and diagnosis of internal organs of a patient. During the test, a patient forms an O-ring with a first hand by placing the finger tips of his thumb and one of his remaining fingers together, and a sample of tissue of an internal organ is placed in contact with the patient's second hand. The patient's internal organ is non-invasively externally probed with a probing instrument. The internal organ is the same type of organ as that of the sample. Simultaneously, a tester attempts to pull apart the O-ring shape of the first hand by means of the tester placing his thumb and one of the remaining fingers of each of his hands within the O-ring shape of the patient to form interlocking O-rings and pulling the thumb and the finger of the patient apart due to an electromagnetic field of the tissue of the sample interacting with an electromagnetic field of the internal organ being probed. This interaction is detected by the ability to pull apart O-ring shape, thereby permitting imaging of the boundaries of the internal organ being probed.
[0019] U.S. Pat. No. 5,855,539 discloses a kinesiology testing apparatus having a base, and a foot treadle having a first end and a second end. The first end of the foot treadle is pivotally attached to the base. The apparatus includes a line having a first end and a second end, whereby the second end of the line is secured adjacent to the second end of the foot treadle. Means is provided for securing the first end of the line to a person's arm. When a person has his arm extended out parallel to a floor, a downward force exerted by a foot of the person upon the foot treadle transmits, via the line, a downward force upon the persons arm.
[0020] In spite of the above advances, there remains a need for improved systems, devices and methods for efficiently diagnosing medical conditions using muscle response testing and treating the medical conditions using magnetic devices.
SUMMARY OF THE INVENTION
[0021] In one embodiment, the present invention discloses a method and system for placing one or more magnetic devices, such as an octapolar magnetic device, at a location on the body that is determined through using muscle response testing (MRT). The placement of the one or more magnetic devices preferably stimulates the electromagnetic lines in the body causing the bioelectrical energy in the body to flow freely. When the rivers of bioelectrical energy flow freely (as taught by traditional Chinese, Japanese, Indian, and Korean medicine), the individual feels better and heals faster.
[0022] In one embodiment, the present invention relates to systems, device, and methods for the treatment of health issues related to the blockage of the electromagnetic lines of the body. A blockage may result from either a lack of sufficient bioelectrical energy flow, or because of too much flow in one line and not enough in another. It has long been known that when these electromagnetic lines in the body are hindered in some way it causes disease. By stimulating the bioelectrical flow (Chi in Traditional Chinese Medicine (TMC) and Ki in Japanese Medicine), a physical healing of a variety of issues may take place.
[0023] In one embodiment of the present invention, multi-polar magnetic devices are placed on one or more points or locations on the body that have long been used for the stimulation of bioelectrical energy flow that is crucial to good health. In one embodiment, a multi-polar magnetic device has two positive and two negative poles alternating diagonally at the corners within a square 2×2 grid within the same plane. A flux field produced by the magnetic device opens magnetic lines at the desired point for healing the patient.
[0024] In one embodiment, the magnetic device has four disc-shaped magnetic bodies that are housed in a non-metallic enclosure that holds the magnetic bodies in place and in relative alignment with one another. It is believed that the relative orientation of the magnetic discs relative to one another enhances the performance of the device, because their collective orientations combine to produce a suitable field gradient that properly stimulates the electromagnetic lines of the body. The magnetic device includes an enclosure that has a prominent directional arrow, which is an important element contributing to the effectiveness of the systems and methods disclosed herein because it enables medical personnel to properly orient the magnetic devices for maximizing therapeutic benefit.
[0025] More than one device may be worn at a time. The two or more devices are preferably used at different points or locations on the body, whereby the points or locations are determined through Muscle Response Testing (MRT). The multi-polar magnetic devices are preferably not used in close proximity to one another, as doing so has been found to disrupt the field gradient of each apparatus.
[0026] The particular locations on the body used for the placement of the magnetic devices have been used for centuries in Eastern medicine. The placement of the magnetic devices at acupuncture points on the body is customized to a patient's needs. Through the relatively new science of Muscle Response Testing (MRT) or Manual Applied Kinesiology, blockages or points of correction on the body are located. After the exact placement points are identified, MRT is used again to determine one or more of the following: 1) the order of placement or placements, 2) the duration that each magnetic device will be left in place, 3) determining whether two or more device should be placed on the body at the same time or whether they should be placed one at a time in a series, and 4) determining whether the same placement series will be repeated or a new placement series will be used.
[0027] These and other preferred embodiments of the present invention will be described in more detail below.
BRIEF DESCRIPTION OF THE DRAWING
[0028] FIG. 1 shows a system for treating a patient including a pair of multi-polar magnetic devices, in accordance with one embodiment of the present invention.
[0029] FIGS. 2A-2C show a multi-polar magnetic device, in accordance with one embodiment of the present invention.
[0030] FIG. 3 shows a schematic top plan view of a multi-polar magnetic device, in accordance with one embodiment of the present invention.
[0031] FIGS. 4 and 5 show cross-sectional views of the multi-polar magnetic device of FIG. 3 .
[0032] FIGS. 6A-6F show a method of attaching a multi-polar magnetic device to a patient, in accordance with one embodiment of the present invention.
[0033] FIG. 7 shows acupuncture points and the main meridian channels on a human body.
[0034] FIGS. 8A-8D show Jin Shin Jyutsu points on a human body.
[0035] FIG. 9 shows meridian lines in a human body.
[0036] FIGS. 10A and 10B show a method of testing a patient, in accordance with one embodiment of the present invention.
[0037] FIGS. 11A-11C show a method of testing a patient, in accordance with one embodiment of the present invention.
[0038] FIGS. 12A-12C show a method of testing a patient, in accordance with one embodiment of the present invention.
[0039] FIGS. 13A-13B and 14 show some examples of the direction of energy flow through a human body.
[0040] FIG. 15A shows ascending energy flow through a human body.
[0041] FIG. 15B shows descending energy flow through a human body.
[0042] FIGS. 16 and 17 show the relationship between the teeth and parts of the human body.
[0043] FIG. 18 shows a method of treating a patient, in accordance with one embodiment of the present invention.
[0044] FIG. 19 shows a method of treating a patient, in accordance with one embodiment of the present invention.
[0045] FIG. 20 shows a method of treating a patient, in accordance with one embodiment of the present invention.
[0046] FIGS. 21A-21B show a method of treating a patient, in accordance with one embodiment of the present invention.
[0047] FIGS. 22A-22C show a method of treating a patient, in accordance with one embodiment of the present invention.
[0048] FIG. 23 shows a method of treating a patient, in accordance with one embodiment of the present invention.
[0049] FIG. 24 shows a method of treating a patient, in accordance with one embodiment of the present invention.
[0050] FIG. 25 shows a method of treating a patient, in accordance with one embodiment of the present invention.
DETAILED DESCRIPTION
[0051] Referring to FIG. 1 , in one embodiment, a system 100 for treating medical conditions preferably includes a storage case 102 having a base 104 and a cover 106 that is hingedly connected with the base. The base 104 is adapted to receive and hold a pair of octapolar magnetic devices 108 A, 108 B, which may be removed from the base 104 for being applied to a patient. The cover 106 preferably includes an underside 110 adapted to receive a plurality of adhesive discs 112 for adhering the magnetic devices to a patient and an instruction manual 114 that provides instructions for using the octapolar magnetic devices 108 A, 108 B. An elastic band 116 is preferably secured to the underside 110 of the cover 106 for storing the adhesive discs 112 , and the instruction manual 114 within the cover 106 of the case 102 .
[0052] Referring to FIGS. 2A-2C , in one embodiment, an octapolar magnetic device 108 desirably includes a housing 118 made of a non-metallic material, such as a plastic or polymer material, that is adapted to house a plurality of permanent magnets therein. In one embodiment, the housing 118 has a top surface 120 , a bottom surface 122 , and a side wall 124 extending between the top and bottom surfaces. The side wall 124 preferably defines a pentagon shape and desirably includes a first side wall section 126 , a second side wall section 128 , a third side wall section 130 , a fourth side wall section 132 , and a fifth side wall section 134 . The first and second side wall sections 126 , 128 preferably join one another at an acute angle that defines an apex 136 . The housing 118 also preferably includes an alignment marker 138 that is formed in the top surface 120 of the housing. A leading edge 140 of the alignment marker 138 is preferably aligned with the apex 136 of the housing 118 . The top surface 120 of the housing 118 also preferably includes a central marker 142 that is desirably centered between the four magnetic discs located within the housing. As will be described in more detail herein, the alignment marker 138 enables the octapolar magnetic device 108 to be properly aligned on a patient's body for maximizing therapeutic benefit.
[0053] Referring to FIGS. 3-5 , in one embodiment, the octapolar magnetic device 108 desirable includes four magnetic discs 144 , 146 , 148 , and 150 that are held by the housing 118 in a particular orientation that accounts for the magnetic properties of each magnetic disc, and so that the magnetic device 108 may be easily handled without altering the arrangement of the magnetic discs. In one embodiment, each of the magnetic discs is preferably a cylindrical, center-charged permanent magnet with each magnetic disc being of equal size and strength. The magnetic poles of the magnetic discs are desirably disposed substantially in two parallel planes, with each plane containing opposing positive and negative magnetic poles. Referring to FIG. 3 , in one embodiment, first and third magnetic discs 144 , 148 have their negative charged faces in a first plane and second and fourth magnetic discs 146 , 150 have their positively charged faces in the first plane. Collectively, the four magnetic discs form an octapolar magnetic device.
[0054] In one embodiment, a first face 152 of the first magnetic disc 144 lies in a first plane P 1 and is negatively charged and a second face 154 of the first magnetic disc 144 lies in a second plane P 2 and is positively charged. Thus, a negative magnetic pole of the first magnetic disc 144 is centered on the first plane P 1 , while a positive magnetic pole of the first magnetic disc 144 is centered on the second plane P 2 . The housing 118 holds the second magnetic disc 146 adjacent the first magnetic disc 144 . A first face 156 of the second magnetic disc 146 lies in the first plane P 1 and is positive charged and a second face 158 of the second magnetic disc 146 lies in the second plane P 2 and is positively charged. Thus, a positive magnetic pole of the second magnetic disc 146 is centered on the first plane P 1 , while a negative magnetic pole of the second magnetic disc 146 is centered on the second plane P 2 .
[0055] The four magnetic discs 144 , 146 , 148 , 150 are desirably oriented to define four vertices of a quadrilateral shape. The four magnetic poles in each of the two parallel planes comprise two positive and two negative poles, the two positive poles defining two diagonal vertices and the two negative poles defining the diagonal vertices of the quadrilateral shape. The distance between the poles in each plane is such that the magnetic field generated by each pole has a significant magnitude at each of the other poles
[0056] Referring to FIG. 3 , the negatively charged faces of magnetic discs 144 and 148 and the positively charged faces of magnetic discs 146 , 150 are in the first plane P 1 ( FIG. 4 ). The two negative poles on discs 144 , 148 define opposite diagonal vertices of the quadrilateral shape, while the two positive poles on discs 146 , 150 define opposite diagonal vertices. Each of the four magnetic poles is magnetically attracted by the two oppositely charged poles and is magnetically repelled by the like charged pole
[0057] Referring to FIGS. 3 and 5 , the magnetic discs preferably have the same diameter, height and shape. In one embodiment, each magnetic disc has a diameter of about 12.7 mm and a height of about 3.2 mm. However, larger or smaller magnetic discs may be used and still fall within the scope of the present invention. When cylindrical magnetic discs with opposite poles on opposite faces are utilized, both major faces of the octapolar magnetic device 108 will exhibit the same magnetic field. Thus, each major face of the octapolar magnetic device can be considered to have a quadrapolar configuration
[0058] In one embodiment, each of the magnetic discs preferably center-charged, which means the magnetic energy is concentrated on the central axis of each magnetic disc rather than being distributed uniformly over the face of the magnet. The magnetic induction field over the center-charged face has a steeper gradient than the field over a non-center-charged face. Suitable center-charged magnets are manufactured by Delco Remy, a division of General Motors Corporation.
[0059] The housing 118 preferably holds the magnetic discs 144 , 146 , 148 and 150 in the desired orientation. The housing 118 may be made of a thermoplastic material in which the four magnetic discs are held.
[0060] The alignment marker on the magnetic device has great importance regarding the treatment methods disclosed herein because the energy flow in bodies can become disrupted, thereby causing a variety of health issues. Energy can become stagnated, thus needing to be dispersed or it can be lacking in an area and need more from other areas to bring it into balance. In Jin Shin Jyutsu and other similar techniques, this is done by directional hand placement. The energy flow of the body is influenced by the way the hands are placed while the patient is being worked on by the practitioner. In the present invention, it is done by the use of the alignment marker and how the magnetic devices are oriented on the body. This is very important in achieving the re-establishment of proper energy for resulting in the elimination of disease. The alignment marker on the magnetic device influences the path and the direction of the energy flow in the body in the same way.
[0061] Referring to FIGS. 1 and 6 A- 6 F, in one embodiment, at least one of the octapolar magnetic devices 108 is attached to a patient's body. Referring to FIGS. 1 and 6A , one of the magnetic devices 108 and at least one adhesive disc 112 is removed from the case 102 . Referring to FIGS. 6A and 6B , a pair of tabs 160 A, 160 B is peeled away from a sheet 162 to expose a top face of an adhesive disc 164 , which is preferably transparent. Referring to FIG. 6C , the bottom major face 122 ( FIG. 2C ) of the housing 118 is preferably pressed against the exposed adhesive disc 164 on the sheet 162 to secure the adhesive disc to the housing 118 . The adhesive disc 164 is preferably attached to the bottom major face of the housing 118 so that the alignment marker 138 on the top major face 120 may be used for aligning the magnetic device on a patient.
[0062] FIG. 6D shows the adhesive disc 164 after it has been attached to the bottom major face 122 of the housing 118 . Referring to FIG. 6E , the housing 118 is preferably secured to a patient's body by pressing the adhesive disc 164 ( FIG. 6D ) and the bottom major face 122 of the housing 118 against the patient's skin. The alignment marker 138 on the housing 118 is used for properly aligning the magnetic device 108 on the patient for maximizing therapeutic benefit. In FIG. 6E , the alignment marker 138 and the magnetic device 108 are aligned at a six o'clock position. In FIG. 6F , the alignment mark 138 and the magnetic device 108 are aligned at a nine o'clock position. The orientation of the alignment marker is determined through muscle response testing as will be described in more detail herein.
[0063] In one embodiment, one or more magnetic devices are placed at locations or points on the body that are widely used in acupuncture, acupressure, Shiatsu, Jin Shin Jyutsu, and reflexology. The locations may also be acupuncture points, electromagnetic lines, meridians, points used in traditional Chinese medicine, locations on the body used in Jin Shin Jyutsu, and locations on the body used in Ki-Iki Jutsu® and Shiatsu. FIG. 7 shows the location of traditional acupuncture points and the main meridian lines on a human body. FIGS. 8A-8D show the location of Jin Shin Jyutsu points on a human body. These points have been observed to have more electrical current than surrounding areas of the body so that they may be used to stimulate the electromagnetic lines or flows of the body. FIG. 9 shows the electromagnetic lines that extend through a human body.
[0064] There is a very strong connection between the brain and the muscles of the body. The brain uses electrical current to direct muscular movement. This relationship makes the muscles very sensitive to the electrical flows of the body, thus making them good indicators of the strengths and weaknesses of the meridian lines or flows.
[0065] In one embodiment, a patient is assessed using Muscle Response Testing (MRT) or Manual Applied Kinesiology (AK). MRT is an effective way of determining energy pathways that are disrupted.
[0066] In one embodiment, one muscle is isolated, usually the deltoid, and consistent pressure is put upon it by gently but firmly pressing downward on the arm. Other muscles may be tested, however, the deltoid muscle is most commonly used for testing. When meridian line or flow weakness or blockage is identified through the electrical response of the muscle, the same technique may be used to determine which therapies are needed to strengthen the line and restore flow once again. The process is somewhat similar to finding a “blown” fuse in an electrical system in a house and replacing it to restore the electrical circuit and its flow of current.
[0067] When a patient/client is about to be tested, the first step is to check the polarity of the individual. As used herein, the terms patient and client may be used interchangeably. The Earth is a huge magnet and the body acts as an electromagnetic. There is a magnetic difference between the top of a patient's head (North Pole), and the bottoms of the patient's feet (South Pole). There is also a difference in the patient's hands, with the palm of the hand being the South Pole and the back of the hand being the North Pole.
[0068] Normal Polarity. Referring to FIGS. 10A and 10B , when the back of the hand is placed on the top of the patient's head, if the individual's polarity is correct, the deltoid (or whatever muscle is being used) will register weakness, and the arm will weaken. The reason for this is that the patient has two like magnetic poles. The top of the head is North, and the back of the hand is North, and as with any other type of magnet two similar poles will repel each other. The patient cannot feel the repulsion but the brain and the nervous system perceive it immediately and the inner reflexes to all the muscles are slightly weakened.
[0069] Normal Polarity. When the patient places the palm of the hand on the top of the head, if the individual's polarity is correct, the deltoid (or whatever muscle is being used) will register strength. The reason for this is that the patient has two opposite poles. The top of the head is North and the palm of the hand is South so there is an attraction, whereupon the computer in the brain is not affected so that the muscles keep their strength.
[0070] Unstable Polarity. Unstable polarity exists when the palm of the hand is placed on the top of the head and there is no change in the strength of the muscles. If the patient places the palm of the hand on the top of the head and the muscles weaken, this is an indication of a problem that must be corrected before the test can begin. The usual causes of polarity issues in the body are lack of water, structural ankle issues, heavy jewelry (metal will disrupt electrical flow), and occasionally cell phones. When the above polarity disturbances occur, which is not common, they must be corrected before continuing.
[0071] In one embodiment, Muscle Response Testing (MRT) is used to determine if the system and methods will work for the patient. Referring to FIGS. 11A-11C , in one embodiment, the patient can hold a magnetic device in their hand and the muscles will respond with either strength or weakness. If the arm tests strong while holding the device, that indicates that the magnetic therapy will work well for the body in promoting healing. If the muscle displays weakness while the individual holds the device that indicates that the therapy would not be the optimum method to promote healing. If the patient touches the magnetic device and the muscle displays strength that indicates that the system and methods will work well and help promote healing. The patient can also touch a device and if their arm is weak it would not be the best method to promote healing in their case.
[0072] After getting a positive response that the magnetic devices will benefit the patient, a determination is made regarding where the device is to be placed on the patient's body. This is once again determined by MRT. The locations or points chosen are ones used for centuries to stimulate the electromagnetic lines or flows in the body. The patient's symptoms help guide the practitioner to the proper location but finding the exact spot of placement is a process of elimination. Referring to FIG. 8B , in one embodiment, point # 4 located at the base of the skull on the right side of the body is used. When the # 4 location is pointed to and the deltoid responds with strength the tester knows there is not problem along this energy flow or line. If the # 4 location is pointed to and the response is a weakening of the deltoid muscle the indication is there are issues with this line or flow in the body and a device should be placed there. This process is used to check the points or locations of the body that could be used for possible device placement. The confirmation of the # 4 location is in agreement with the patient's symptoms because they suffer with headaches that occur mostly in the area of the forehead, they get neck pain, and have a very stubborn personality, all of which originate with a malfunctioning of the # 4 flow.
[0073] Next, MRT is conducted for determining the direction of the arrow on the magnetic device when the device is placed on the patient's body. The direction of the arrow will directly impact the success of the treatment methodology because the electromagnetic lines or flows run in many different directions. The tester uses a process of elimination. Testing is conducted with the arrow on the magnetic device pointed in each direction, one at a time, by either placing the device on the patient or letting the patient hold the device and shift the arrow each time a test is conducted. Referring to FIG. 12A , in one embodiment, the alignment marker 138 on the magnetic device 108 is pointed to the individuals left, the deltoid goes weak, which is a negative response, and the body's answer is “no.” Referring to FIG. 12B , in one embodiment, the alignment marker 138 on the magnetic device 108 is pointed down, the deltoid goes weak, which is a negative response, and the body's answer is “no.” Referring to FIG. 12C , in one embodiment, the alignment marker 138 of the magnetic device 108 is pointed to the patient's right, the deltoid muscle is strong, and the body's answer is “yes.” Based upon the above scenario, the magnetic device is placed on the # 4 point, on the right side of the body, with the directional arrow pointing to the patient's right.
[0074] If none of the tested arrow directions (i.e., up, down, left or right) provided a “yes” response, then the MRT testing will be conducted using the face of a clock. In one embodiment, the directional arrow is placed between 1 and 3 o'clock. The deltoid muscle is weak so the patient's body does not want the arrow in this direction. Next, the placement arrow is positioned between 3 and 6 o'clock, the deltoid is weak, a negative response, the body does not want the arrow in this direction. Next, the directional arrow is positioned between 6 and 9 o'clock, the deltoid muscle is strong indicating a positive or a yes, which means that the body wants the directional arrow pointing between 6 and 9 o'clock. Because it was already determined that the body did not test for the arrow direction to be down or to the right or left, there is no need to test for the 6 o'clock or 9 o'clock directions. The next test is the 7 o′clock direction, the deltoid goes weak, a negative response, the body does not want the 7 o'clock direction. The directional arrow is then placed in the 8 o'clock direction and the deltoid muscle is strong indicating a positive response, the body wants the arrow pointed in this direction. The testing indicates that the magnetic device should be placed on the right # 4 location with the directional arrow pointing to 8 o'clock.
[0075] In one embodiment, a determination is made regarding how long the magnetic device should be worn on the body. Again, this determination is preferably made through a process of elimination using MRT. In one embodiment, time is grouped in blocks to facilitate the test. For example, the device will be worn for 10 hours, the deltoid goes weak, a negative response, it will not be worn for 10 hours. The device will be worn under 10 hours, the deltoid is weak, a negative response, the device will not be worn under 10 hours. The device will be worn over 10 hours, the deltoid is strong, a positive response. How much over 10 hours? The device will be worn for 15 hours, the deltoid is weak, and will not be worn for 15 hours. The device will stay on for under 15 hours, the deltoid is strong, indicating a positive response by the body. This result indicates that the device should be worn for between 11 and 14 hours. The test continues. The device will stay on the body for 11 hours, the deltoid is weak, a negative response. The device will be left on the body for 12 hours, the deltoid is weak, a negative response. The device will be left on for 13 hours, the deltoid is weak, a negative response. The device will be left on for 14 hours, the deltoid is strong, a positive response. The test results indicate that the device should be placed on the right # 4 location with the arrow direction at 8 o'clock for 14 hours.
[0076] The next stage of testing is used to determine if the device placement will be re-applied. This can be determined by asking “will the placement need to be re-applied?” or having the patient hold the device by the # 4 location. If the deltoid is weak, the answer is negative, a no. If testing indicates the deltoid is strong, the answer is positive, a yes.
[0077] During testing, statements are verbalized initiating a response from the brain that affects the deltoid (or whatever muscle is chosen for testing). The device placement on the body will be re-applied two times, the deltoid is strong, a positive response, it will be repeated two times.
[0078] For determining whether the device should be reapplied in the location, duration, and direction, the following questions are asked. The device placement will be worn two days in a row, the deltoid is weak, a negative response, it will not be worn two days in a row. The statement is then made that the device placement on the body is spaced every other day, the deltoid is weak, a negative response, it will not be repeated every other day. Placement on the body will be repeated every third day, the deltoid is strong, a positive response, the device will be worn on the body for 14 hours, taken off, and repeated again for 14 hours 3 days later.
[0079] Based upon the above responses, the device needs to be worn on the right # 4 location with the arrow toward 8 o'clock, for 14 hours. After the 14 hours is complete, the device is to be removed. On the third day after removal the device is to be reapplied to the body at the same location, with the arrow direction to be the same, and the amount of time left on the body to be the same.
[0080] MRT is conducted to determine if a second placement is needed to further improve line flow. The deltoid is weak, a negative, no. Another placement will not be needed. If the test had been positive, the above process would be repeated for determining the location, direction, and length of time for placement of the second device.
[0081] Multiple Device Placement. The number of placements on the body may vary. In one embodiment, a determination is made if the method will benefit the health of the patient. The patient touches the device on a table, the deltoid is strong, a positive response, the individual would benefit from the method. The patient holds one device in their hand and a statement is made that only one location will be needed. The deltoid goes weak, indicating a negative response. The patient holds two devices in their hands and a statement is made that two locations will be needed. The deltoid is strong, indicating a positive response, the body wants devices in two locations on the body.
[0082] Testing is now conducted to determine where the two separate locations are on the body. The average number of devices is usually between one and three but can go higher in some cases. Another way to test for locations is to have the patient touch one device on a table, if the deltoid is weak, it is a negative response and more than one device is needed.
[0083] The patient touches two devices on the table, the deltoid is strong, a positive response from the body. This indicates that there should be two locations on the body for placement of the devices.
[0084] The patient is tested to determine if the locations to be used are used in Jin Shin Jyutsu, the deltoid is strong, indicating a positive response, we are looking for locations used in Jin Shin Jyutsu.
[0085] To facilitate the test, the body is broken up into sections. The points are located below the waist on the front of the body. The deltoid is weak, a negative response, the locations are not on points below the waist on the front of the body. The points are located below the waist on the back of the body. The deltoid is weak, a negative response, the locations are not on points below the waist on the back of the body. The points are located above the waist, the deltoid muscle is strong, a positive response, either one or both will be located above the waist. Testing has indicated that the point or points are located above the waist. The next section tested is above the waist on the back of the body. The deltoid muscle is weak, a negative response, the location is not on the back of the body.
[0086] Through a process of elimination it is determined that at least one or both of the locations are on the front of the body. This is confirmed by further testing. The deltoid muscle is strong indicating the device or devices will be placed on locations on the front of the body above the waist.
[0087] To find the exact location, each point will be tested by either the patient or the practitioner pointing to the area. In this case a weakness on the spot is the signal by the brain via the deltoid muscle indicating a line flow problem. One location has been found on the front of the body, the energy lock or sphere # 22 ( FIG. 8A ). When the left # 22 location was touched either by the patient or the practitioner, the deltoid weakened indicating line flow disruption. The directional arrow is then tested as previously discussed and the arrow will be facing to the patients' right.
[0088] At this stage, only one of the two locations has been identified for the particular placement. The testing continues for the second location by testing the arms. The deltoid is strong when the right arm is tested, a positive, yes. The second area of placement is located on the right arm. Again by process of elimination the points on the right arm are each tested and the location that shows up as weakness in the deltoid, indicated by the arm becoming weak, is the # 19 ( FIG. 8A ) by the bend of the elbow. Through a process of elimination, it has been determined that the second location is the energy lock or sphere # 19 on the right arm. The directional arrow will then be tested as described previously. In this case the arrow direction will by facing down toward the fingers.
[0089] For the double device placement it has been determined that the areas of placement will be the left # 22 and the right # 19 . Testing is then conducted to determine if both devices are placed on the body at the same time. The deltoid is weak, a negative response from the body. The devices will not be placed on the body at the same time.
[0090] Testing is conducted to determine if the # 19 will be placed on first, the deltoid muscle is weak, a negative response, the # 19 will not be placed on the body first. Testing is conducted to determine if the # 22 will be placed on the body first, the deltoid is strong, a positive response from the body, the device will be placed on the # 22 first with the arrow direction pointing to the patient's right. The amount of time it will be worn on the body alone is then tested as described previously. It is determined that the left # 22 will be worn on the body first, with the arrow direction to the patient's right, and is worn alone on the body for 5 hours.
[0091] Testing is then conducted to determine what will occur after the 5 hours have passed. The # 19 device is placed on the right arm. Both the # 22 and the # 19 devices are worn on the body together for a MRT time of 10 hours. Testing is conducted to determine what will occur after the 10 hours is complete. The # 22 is to be removed and the # 19 will stay on the arm another 5 hours alone on the body. After the 5 hours is complete all devices are removed. Testing is conducted to determine if the placements will be repeated when the 20 hours of initial placement is completed, or will another placement or placements be needed after the first round of placements. The deltoid muscle is strong, a positive response, another placement or placements will be needed.
[0092] In one embodiment, an individual may conduct MRT on himself, which enables the individual to quickly care for an injury or illness. Teaching MRT to a non-practitioner will enable individuals to care for common health issues such as virus, flu, injuries, etc. Deeper levels of line correction would require a qualified practitioner or trained medical professional.
[0093] Self test method # 1 . In one embodiment, the finger pad of the thumb and the finger pad of one of the fingers, usually the pointer or middle, are gently slid against each other. If the fingers are dry there should be very little to no resistance to this movement. If something is placed in the opposite hand that is good for the body, the individual will feel resistance between the two fingers and a feeling of tackiness will develop. If something is placed in the opposite hand that is not good for the body, then there will be no change or the slip of the fingers increases. This method can also be used to isolate locations on the body that show blockage. The regular protocol for MRT can be followed.
[0094] Self test method # 2 . This method uses a finger loop. The muscles of the fingers are used to evaluate the needs of the body. The fingers on one hand create a loop and, using the finger of the opposite hand, an individual gently applies pressure to try to break the looped fingers apart. If the individual cannot pull the finger through the loop that would be a strong or positive test. It is making the body's electrical flow stronger. If the individual is able to pull the finger through it is making the body's electrical flow weaker. This test uses the same principle that are used when MRT the arm. Once again the MRT protocol for the therapy is followed. Although two self tests are disclosed, there are other self test methods that may be used.
[0095] Other ways to access line or flow blockages. Taking a pulse reading, which is used extensively in TCM, can help determine which lines or flows are problematic. From this information, the practitioner or medical professional can press on the locations that correlate to the lines having difficulty. The areas where devices should be placed will most likely be tender, and sometimes even painful. They can also feel like small hard nodules or lumps, and at times can feel as though there is a little electrical buzz or a pulse. It would then be up to the discretion of the practitioner as to how many devices would be needed, the duration, and the direction of the arrows.
[0096] Any method of identifying meridian or line flow blockage can be adapted to the methods disclosed herein in the same manner as described herein. Methods to access line or flow issues range from machines that use points on the feet and hands, using points on the body, TCM face reading techniques, nail reading, iridology (reading the eye), and sclarolegy (reading the whites of the eyes).
[0097] As can be seen by FIGS. 13A , 13 B, and 14 , energy flow in the body takes many directions. There is also a daytime and evening general energy direction that occurs naturally in the body. In the daytime the flow travels from the feet up the front of the body and down the back. This is called ascending energy. In the evening when the body is ready to rest in sleep the energy flow should reverse and flow from the feet up the back and down the front of the body. This is called descending energy. The proper flow of the ascending and descending energy is very important to good health. Disruption of these flows will effect sleep patterns and fatigue, and impair the proper function of other electromagnetic current lines.
[0098] FIG. 15A shows the ascending energy (flow from feet to head) being stimulated by the hands. The left hand fingers toward the head and the right hand fingers toward the feet are placed on the mid-line of the body. To achieve the same effect with the present invention, a first magnetic device is placed on the navel with the directional arrow pointing down, and a second magnetic device is placed on the coccyx tip with the directional arrow facing up.
[0099] In FIG. 15B , the opposite energy flow is being addressed. The hands are positioned with the right hand on the upper portion of the body with the fingers toward the head and the left hand positioned on the lower part of the body with fingers toward the feet to address the descending energy. To address this energy, the first magnetic device is placed on the navel with the directional arrow facing up, and the second magnetic device is on the coccyx tip with the directional arrow facing down.
[0100] Energy can also become pooled in a certain area of the body. These areas of stagnation can be located by a hardness that is felt just under the skin. The area can be small (¼ inch) or quite large (3-4 inches). These areas are strongly affected by the direction of hand placement on the body or the direction of the alignment markers on the magnetic devices disclosed in the present invention. Thus, hand placement to correct energy flow problems correlates to the alignment markers on the magnetic devices disclosed in the present invention.
[0101] The present invention preferably has many valuable uses in dentistry because the teeth can have a huge impact on the health of an individual. Many electromagnetic lines run through the teeth. So when the teeth have issues, it will affect the lines or flows that pass through them causing disruption.
[0102] We can see how teeth impact the health of an individual when we examine the connection tooth # 3 , the first molar on the upper right side of the mouth, has with the rest of the body. Referring to FIG. 16 , a serious problem with this tooth can affect the pancreas, small intestine, larynx, mammary gland on the right breast, stomach, medial ankle, anterior knee, anterior hip, TMJ on the right side of the jaw, maxillary sinus, tongue, and thyroid.
[0103] Another example is tooth # 25 , the central incisor right lower. Referring to FIG. 17 , serious problems with this tooth could affect the adrenal glands, nose, sphenoid sinus, frontal sinus, sacrao-coccygeal joint, posterior hip and knee, kidney on the right side, bladder, genitor-urinary, ovaries, uterus, testicles, prostate, and the right ear.
[0104] A relatively new discovery in dentistry is a condition that can occur when a tooth is extracted, called a cavitation or “NECO” (Neuralgia Inducing Cavitational Osteonecrosis) lesion. The term NECO was given because some specialists feel that this dental issue could be responsible for Trigeminal Neuralgia as well as other types of facial pain.
[0105] A cavitation is a hole in the bone, which usually occurs where a tooth has been removed. In an X-ray, this area will show up as a shadow of a tooth. After a tooth is extracted, some feel that the membrane of the tooth remains behind so that the bone at this location never fills in. It may also be caused by the lines or flows that feed that particular tooth. If the lines or flows are experiencing a weakened condition, the space left behind after an extraction will have difficulty healing. The result is a spongy spot in the jaw at the extraction site. Other traumas can also cause cavitations.
[0106] There are many health dangers associated with a cavitation. These areas become breeding grounds for bacteria and the toxins they give off. They can also harbor mercury, and are very detrimental to the balanced flow of the energy lines, acting almost like a “leak” in the bioelectrical energy of the body. It is almost impossible to completely correct weakened flows that run through a cavitation or NECO lesion, which makes them a silent cause of recurring health issues.
[0107] Prior to the present invention, surgery would have been the recommended course to handle a cavitation. Surgery is very costly, painful, and can leave behind scar tissue which carries its own set of health issues. In one embodiment of the present invention, a magnetic device may be placed on an area of the face that correlates with cavitation location in the jaw so that the cavitations or NECO lesions can be stimulated to heal.
[0108] Muscle Response Testing is used to determine 1) the proper location for the magnetic device on the face, 2) the direction of the arrow on the magnetic device, and 3) the amount of time needed for placement of the magnetic device. In one embodiment, the average time the magnetic device will be worn on the face to correct a cavitation is around 56 hours.
[0109] The methods disclosed herein may also be used for other dental issues. When magnetic devices are placed near location # 18 ( FIG. 8A ) on the thumb, it can calm the gag reflex some experience during dental work. It may also help speed healing with any type of dental procedure by addressing the energy lines that affect the particular area of the mouth that is being worked on. These placements are very individualized and are not necessarily placed at the site of the actual dental work. As an example, a person who received a root canal may wear the magnetic device on location # 20 ( FIG. 8A ) on the forehead. This facilitates healing, which, in turn, helps with pain and discomfort. The patient is able to go about their business as through dental work had not been performed. This type of placement would follow the same procedure that has been outlined herein for placement of devices on an individual.
[0110] The present invention may be used to treat patients having a wide variety of conditions and diseases as discussed in case studies 1-10 below.
[0111] Case Study #1. A young girl about 10 years old had a fear of the dark. Whenever the family would arrive home at night, she couldn't enter the house until lights were turned on. MRT was conducted to determine if the present invention would work to help her alleviate her phobia of the dark. Energy flows or lines are responsible for anything the body experiences; they are even responsible for phobias that individuals may have. To test the patient, she was asked to think about the dark, which weakened her deltoid muscle, registering as weakness in her arm when gentle pressure was applied. The patient was then told to hold one of the magnetic devices in her hand and she was asked to think about the dark. This time the deltoid muscle was strong, indicating that the present invention would help her overcome her fear of the dark. Once again, the patient was asked to think about her phobia and tested which contact points on her body showed weakness as described previously under the method. These would be the locations that affected the lines or flows responsible for the phobia.
[0112] Referring to FIG. 18 , during MRT testing, through a process of elimination, it was discovered that the energy sphere or lock # 16 on the outside of the left ankle was registering weakness when she thought about the dark. It was determined that only one device was needed because only one location made the deltoid muscle go weak, indicated by the arm weakening. Also, when the young patient held one device in her hand, her deltoid muscle was strong but when another was added, it weakened, indicating her body only needed one device placed in one location. The location would be the left # 16 on the outside of the ankle.
[0113] The device was placed against the area and tested the strength of the deltoid by process of elimination as described in the method, it was determined that the arrow direction would be down. Then through asking the body verbal questions while muscle testing, it was determined that she would need to wear the device on the left # 16 for 10 hours which, because of her age, and the fact that she was in school, she wore while she slept. Arrow direction would be down. Through MRT we determined the apparatus would be worn three nights in a row. The Result: Her fear of the dark is vastly diminished.
[0114] Case Study #2. A patient had not been feeling well for a few weeks and through muscle response testing it was determined that this was bacterial in origin. As with Case Study #1, MRT was conducted to determine which point on the body was the root of the problem. The location of the problem would show up as a weakness in the deltoid muscle reflected in the testing arm weakening when light pressure was gently applied, and the problem location was touched.
[0115] The patient then held the magnetic device to see if the body would respond to the new therapy. The response was a strengthening of the arm when the weak area was touched while the individual held the apparatus. Then the number of devices needed was tested. The patient needed only one device because when two were placed in his hand, the patient's deltoid went weak, and only one location was found when points on the body were tested. Referring to FIG. 19 , the location needed was the left # 3 on the top of the shoulder blade close to the spine. This location fits with the prior test that indicated that the problem was bacterial in nature as the # 3 point is considered the body's natural antibiotic. A test for arrow direction was conducted by moving the arrow on the # 3 location until the arm registered strength. This happened when the arrow was toward the patient's right.
[0116] The test continued using verbal questions to determine the amount of time the patient would need to wear the device. The length of time was 10 hours and even though it did not have to be applied at a specific time (occasionally the time of application does matter as noted in the Chinese meridian clock) the patient wished to sleep with it on. When the patient woke up the next day, he reported that the symptoms he had been suffering with were gone.
[0117] Case Study #3. This case involved a tooth extraction that would possibly have led to a cavitation in the area due to the fact that the lines or flows that passed through that tooth were already showing signs of weakness or blockage. Cavitations or NECO lesions are caused by a lack of blood flow to the area of the extraction leaving the tissue in a necrotic state. In a sense it's a black hole. Since many of these energy lines run through the teeth, cavitations can cause problems along those lines or flows. These are very difficult to correct if the cavitation or NECO lesion is not addressed.
[0118] Referring to FIG. 20 , the tooth extracted was # 15 , the second molar. This tooth correlates with the parathyroid, tongue, maxillary sinus, left jaw TMJ, anterior hip, anterior knee, medial ankle joint, spleen, stomach, left breast, bladder, and pancreas. The area was MRT by pointing to different locations on the outside of the mouth close to the extraction site until the deltoid weakened. When the weakened area was located, the apparatus was applied over the location on the outside of the mouth.
[0119] The direction of the arrow was then tested, and it was to point toward the back of the head. Through verbal questions it was discovered that the device was to be left on for a total of 59 hours straight (there are cases where the time can be broken up). When examined three days later, the area of extraction was almost totally healed, the patient felt better, and the patient reported that her skin was healthier. Due to the fast healing of the area, pain was kept to a minimum as well.
[0120] Case Study #4. A patient had a pinched nerve in his neck. He was unable to move his head to the left or the right. The pain was so intense that it was to the point of nausea. This went on for about three weeks while other methods were tried unsuccessfully. The patient was tested to see if the new method would work for him and it was determined that it would, by the muscles of his arm registering strength. The patient was then tested to see which locations of the body would be used to correct his problem. Referring to FIGS. 21A and 21B , three locations were determined through MRT, which were the area of the # 12 on the left side of the neck, the # 15 on the left side of the groin area, and the # 24 on the top of the left foot. At each location, the arrow direction was then tested and it was determined that the arrows at all three locations would be facing to the right of the individual. The patient was then tested to determine length of treatment and it was determined that all three devices were to be applied at the same time and were to stay on together for a total of 12 hours. It was also determined through MRT that at the end of the 12 hours the # 15 and # 24 were to be removed and the # 12 was to remain on the neck for another 12 hours. Before the devices were placed on the body, the patient could not move his head to the right or left. After treatment, the patient could freely move his head and the pain had almost entirely disappeared. He reported being about 70-80% better than the day before. A second set of devices were recommended to reach 100% correction, but the patient felt so good he never applied them.
[0121] Case Study #5. A 28 year old patient was having a lot of health problems after he was in a serious car accident. The testing point for the vagus nerve was determined to be very weak, which is an indicator for major structural problems, probably as a result of the car accident. These structural problems were affecting the lines or flows for the gallbladder, umbilicus, and bladder energies. He was experiencing most of the symptoms that these blocked lines will manifest.
[0122] After identifying the problem lines or flows, MRT was used to determine which lines needed to be addressed first. Through MRT, it was determined that the gallbladder line needed to be worked on first. This determination was made by verbal questions. It was also determined that two locations were to be used to restore flow to the gallbladder line. Referring to FIGS. 22A-22B , the devices were placed on the # 14 located along the rib cage on the left side of the body, and the # 16 located on the left outer ankle. MRT was conducted to determine that the arrow on the # 14 was to be pointing to the individual's left, and on the # 16 , the arrow pointed down.
[0123] Both apparatuses were to be applied to the body at the same time and were to be left on together for a total of 10 hours. After the 10 hour placement was completed, the # 16 was to be removed, but the # 14 was to stay on another 10 hours by itself. After the # 14 was worn on the body for a total of 20 hours, it was to be removed also. It was determined through MRT that the patient would need a second placement series, but a space of a week would be needed between the two placement series. The patient reported, in the seven days between placements, that he felt a bit better every day. He reported that it was the first time he felt better since the accident.
[0124] Case Study #5—Second Round of Placements. The second round of placements was necessary to balance out a flow called the 5 th stratum, and the umbilicus line. Referring to FIGS. 22B and 22C , once again, two devices would be needed, with one placed on the left # 19 on the arm by the elbow, and the other on the left ring finger. The arrow on the device placed on the left # 19 would be facing to the right of the patient as would the device placed on the ring finger. It was determined that the # 19 was to be placed on the body first and would remain on the body alone for a total of 10 hours. After the completion of the 10 hours another apparatus was added to the finger. Both devices were to stay on together for another 10 hours. When the 10 hours were complete, the ring finger device was to be removed, and the device on the # 19 was to remain on for another 5 hours. This second set brought the patient's vagus point into complete balance, as indicated by the deltoid muscle registering strength when the point was tested. At the end of treatment, it was determined that the patient was symptom-free.
[0125] Case Study #6. The patient was suffering from flu-like symptoms. Referring to FIG. 23 , it was determined that one device would be needed, and it was to be placed on the left # 23 , with the arrow pointing to the individual's left. The apparatus was to be left on the left # 23 for 3-4 hours (with influenza it can stay on as long as 9 hours). In three hours all symptoms of influenza were gone.
[0126] Case Study #7. The patient was suffering from a stomach virus, experiencing diarrhea, and abdominal rumbling and discomfort. Referring to FIG. 24 , MRT determined that a device needed to be placed on the right # 15 with the arrow direction pointing down toward the feet. The apparatus was to be left on for about 5 or 6 hours. The patient started feeling better shortly after application of the device and by the time 5 hours had passed, the patient felt no symptoms of illness at all.
[0127] Case Study #8. This case study involved a patient that needed a root canal procedure. Referring to FIG. 25 , MRT testing indicated that the device should be placed on the forehead on the left # 20 location. MRT was also conducted to determine whether the device or devices need to be placed on before, during, or after the procedure. It was determined through MRT that one device was to be placed prior to the dental procedure and left on until the procedure was completed, which facilitated the healing of the area and helped eliminate much of the discomfort experienced after the procedure. No pain medication of any kind was needed after the procedure, not even an aspirin.
[0128] While the foregoing is directed to embodiments of the present invention, other and further embodiments of the invention may be devised without departing from the basic scope thereof, which is only limited by the scope of the claims that follow. For example, the present invention contemplates that any of the features shown in any of the embodiments described herein, or incorporated by reference herein, may be incorporated with any of the features shown in any of the other embodiments described herein, or incorporated by reference herein, and still fall within the scope of the present invention. | A system for treating patients includes a first magnetic device including a set of four magnetic discs arranged in a square array, the four magnetic discs including two having negative magnetic poles lying in a first plane and two having positive magnetic poles lying in the first plane, wherein the two magnetic discs having negative magnetic poles extend along a first diagonal line and the two magnetic discs having positive magnetic poles extend along a second diagonal line that crosses the first diagonal line, and a housing containing the four magnetic discs for maintaining the magnetic discs in the square array arrangement, the housing including an alignment marker for aligning the first magnetic device on a patient. | 0 |
CROSS-REFERENCES TO RELATED APPLICATIONS
This application claims the priorities of German Patent Applications, Ser. Nos. 103 08 657.9, filed Feb. 27, 2003, and 103 15 404.3, filed Apr. 4, 2003, pursuant to 35 U.S.C. 119(a)-(d), the disclosure of which is incorporated herein by reference.
BACKGROUND OF THE INVENTION
The present invention relates to a conveyor system for transport of containers, in particular to an airport baggage handling system.
Airport baggage handling systems typically involve a conveyor system having at least one curved conveyor to define a curved transport path. The curved conveyor has one end to define a container entry zone and another end to define a container exit zone, whereby the containers are moved along the transport path by a propulsion drive. Typically, the propulsion drive includes a conveyor belt for support of a side edge of the containers. Conventional baggage handling systems suffer shortcomings because the content accommodated by the container, e.g. bulk material or baggage item, shifts so that the position within the container changes.
It would therefore be desirable and advantageous to provide an improved conveyor system to obviate prior art shortcomings and to maintain a position of the content in the container when negotiating a curved transport path, even when the content rests only upon the container bottom.
SUMMARY OF THE INVENTION
According to one aspect of the present invention, a conveyor system for transport of containers, in particular an airport baggage handling system, includes a conveyor having a curved transport path with one end defining an entry zone and another end defining an exit zone, and a container propulsion mechanism for moving a container along the curved transport path between the entry and exit zones, wherein the curved transport path is constructed for movement of the container in an inwardly inclined disposition for reducing centrifugal forces.
The present invention resolves prior art problems by inclining the container during its advance through the curved transport path. The inclination is hereby so selected as to prevent a shift of the content in the container.
According to another feature of the present invention, the curved transport path is constructed for movement of the container in a manner that an outer side of the container is elevated in relation to an inner side of the container.
According to another feature of the present invention, the conveyor may have a carriage guided on an outer guide rail of the conveyor for lifting the container. This construction realizes a reliable elevation of the container. Suitably, the carriage is detachably connected to the container, when the container enters the entry zone, for conjoint movement of the carriage and the container along the curved transport path by the container propulsion mechanism, and detached from the container, when the container reaches the exit zone. This type of coupling between the carriage and the container can be realized in a simple manner by providing the container with a recess for engagement by the carriage.
According to another feature of the present invention, a return mechanism is provided for moving the carriage back to the entry zone. In this way, a continuous movement of the carriage is ensured in a simple manner. The return mechanism may include a guide rail, which is disposed below the transport path and receives the carriage at the exit zone, and a positioning element for moving the carriage upwards to the entry zone. Suitably, the guide rail is arranged in slanted disposition to allow the carriage to spontaneously roll back to the entry zone by its own weight.
According to another feature of the present invention, the positioning element may be configured in the form of a wheel for moving the carriage upwards about its outer circumference and realizing a form-fitting engagement with the container. The wheel is hereby designed like a miniaturized Ferris wheel with suspended gondolas. As an alternative, lifting of the container may also be implemented by constructing the conveyor with two rails which are disposed at an elevation sufficient to lift the container and which support the outer side of the container. Suitably, each of the rails is constructed as sliding rail so that the need for auxiliary means is eliminated.
According to another feature of the present invention, the rails may be constructed to form staggered ramps in the entry zone and staggered ramps in the exit zone for lifting the outer side of the container in the entry zone to rail level and for lowering the outer side of the container in the exit zone to a horizontal disposition. The provision of staggered ramps prevents an inadvertent tilting of the container and realizes a parallel elevation of the outer container side. Suitably, the ramps are staggered in transport direction by about a container length.
According to another feature of the present invention, the container has a bottom side which rests on the rails. As an alternative, the container may have an outwardly directed projection for support on the rails.
BRIEF DESCRIPTION OF THE DRAWING
Other features and advantages of the present invention will be more readily apparent upon reading the following description of currently preferred exemplified embodiments of the invention with reference to the accompanying drawing, in which:
FIG. 1 is a perspective illustration of one embodiment of a curved conveyor according to the present invention;
FIG. 2 is a perspective cutaway view, on an enlarged scale, of the conveyor of FIG. 1 , illustrating in detail the container entry zone;
FIG. 3 is a fragmentary perspective illustration of another embodiment a curved conveyor according to the present invention; and
FIG. 4 is a perspective cutaway view of the conveyor of FIG. 3 , illustrating the container in upright position form a different viewing direction.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
Throughout all the Figures, same or corresponding elements are generally indicated by same reference numerals. These depicted embodiments are to be understood as illustrative of the invention and not as limiting in any way. It should also be understood that the drawings are not necessarily to scale and that the embodiments are sometimes illustrated by graphic symbols, phantom lines, diagrammatic representations and fragmentary views. In certain instances, details which are not necessary for an understanding of the present invention or which render other details difficult to perceive may have been omitted.
Turning now to the drawing, and in particular to FIG. 1 , there is shown a perspective illustration of one embodiment of a curved conveyor according to the present invention, generally designated by reference numeral 1 and forming part of a conveyor system for transport of containers 2 for item pieces or also bulk material in a direction indicated by arrow A. The conveyor 1 is curved to define a curved transport path with one end defining a container entry zone 3 and another end defining a container exit zone 4 . The containers 2 are moved along the transport path by a container propulsion device, generally designated by reference numeral 5 and including a conveyor belt 6 which is operated by a motor (not shown) and intended for support of one side of the containers 2 (in FIG. 1 , the right-hand side). The conveyor belt 6 is hereby curved in conformity of the curved configuration of the transport path. The containers 2 are guided by the conveyor belt 6 via freely rotatable guide rollers 7 which are arranged on the inside of the curved conveyor belt 6 . The other side of the containers 2 is supported via a carriage 8 on a rail construction, generally designated by reference numeral 9 and including two guide rails 10 a , 10 b in parallel relationship.
The rail construction 9 is arranged at an elevated relationship to the conveyor belt 6 so that the containers 2 are inwardly tilted in the curved transport path. To realize a three-point support, each container 2 is supported on the inner side upon the conveyor belt 6 and on the outer side upon a support bar 11 which is secured to the carriage 8 .
When reaching the exit zone 4 , the form-fitting connection between the carriage 8 and the respective container 2 is released and the carriage 8 moves downwards. Subsequently, the carriage 8 is returned to the entry zone 3 by means of further guide rails 12 which are arranged below the conveyor belt 6 and thus below the transport path. FIG. 1 shows only small portions of the guide rails 12 for ease of illustration and clarity. Of course, the guide rails 12 extend to the entry zone 3 . In a direction toward the entry zone 3 , the guide rails 12 are inclined or oblique so as to allow the carriages 8 to spontaneously roll back to the entry zone 3 by their own weight. The guide rails 12 thus act as carriage return mechanism. Of course, the return of the carriages 8 from the exit zone 4 to the entry zone 3 may also be realized in a different way, for example by means of a friction belt.
Arranged in the entry zone 3 is a positioning element 13 by which the carriages 8 are moved upwards below a ready container 2 for form-fitting engagement of the carriage 8 with the container 2 .
Turning now to FIG. 2 , there is shown a perspective cutaway view, on an enlarged scale, of the conveyor 1 of FIG. 1 , to illustrate the positioning element 13 and two containers 2 in more detail and from a different viewing direction. The positioning element 12 is configured as wheel resembling a miniaturized Ferris wheel, whereby the carriages 8 are attached about the outer circumference of the wheel like suspended gondolas of a Ferris wheel and moved upwards. When reaching the apex of the wheel, the carriage 8 is detachably secured to the containers 2 by engaging a recess 14 ( FIG. 1 ) of the container 2 , and then moved together with the advancing container 2 . In the entry zone 3 , the outer side of the rail construction 9 is provided with an ascent 15 to elevate the outer side of the container 2 in relation to the inner side of the container 2 .
The containers 2 supplied to the entry zone 3 may be queued up, and the container 2 can be moved by a catch 16 to the pick-up position for detachable connection with the carriage 8 . In this position, the upper part of the carriage 8 is received in the recess 14 in the bottom of the container 2 , with the recess 14 situated approximately in mid-section of the container length side. Form this position on, the carriage 8 is freely movable along the transport path.
Instead of the guide rollers 7 , the propulsion device 5 may be supported by a driven vertical belt which travels at a same speed and in a same direction as the conveyor belt 6 . The container propulsion device 6 may be realized by frictional engagement or form-fitting engagement (not shown).
Referring now to FIG. 3 , there is shown a fragmentary perspective illustration of another embodiment of a curved conveyor according to the present invention. Parts corresponding with those in FIG. 1 are denoted by identical reference numerals and not explained again. The description below will center on the differences between the embodiments. In this embodiment, provision is made for two rails, an outer rail 17 a and an inner rail 17 b , for lifting the outer side of the containers 2 . The rails 17 a , 17 b are configured as sliding rails and have each a support surface 18 situated above the conveyor belt 6 . In the entry zone 3 of the transport path, the rails 17 a , 17 b have ends which are staggered in transport direction A to define ramps 19 a , 19 b , whereby the ramp 19 b of the inner rail 17 b begins ahead of the ramp 19 a of the outer rail 17 a , as viewed in transport direction A.
Transfer of the containers 2 into the entry zone 3 is realized by two conveyor belts 20 whereby the conveyor belt 6 receives the containers 2 from the conveyor belts 20 in lying disposition. Suitably, the containers 2 are properly guided by a profiled guide member 21 .
FIG. 4 shows in more detail the entry zone 3 of the conveyor of FIG. 3 from a different perspective, whereby the container 2 is positioned upright for ease of understanding and to show the bottom underside of the container 2 . As can be seen in FIG. 4 , the bottom underside of the container 2 has grooves 22 , 23 , 24 as well as shoulders 25 , 26 , whereby the grooves 22 , 23 , 24 and the shoulders 25 , 26 , are so configured as to allow an even elevation of the container on the outer side. In other words, the outer edge 27 of the container 2 extends horizontal. The guide member 21 hereby engages the groove 24 during transfer from the conveyor belts 20 to the conveyor belt 6 .
While the invention has been illustrated and described in connection with currently preferred embodiments shown and described in detail, it is not intended to be limited to the details shown since various modifications and structural changes may be made without departing in any way from the spirit of the present invention. The embodiments were chosen and described in order to best explain the principles of the invention and practical application to thereby enable a person skilled in the art to best utilize the invention and various embodiments with various modifications as are suited to the particular use contemplated. | A conveyor system for transport of containers, in particular an airport baggage handling system, includes a conveyor having a curved transport path with one end defining an entry zone and another end defining an exit zone. The containers are moved by a container propulsion mechanism along the curved transport path between the entry and exit zones, wherein the curved transport path is constructed for movement of the containers in an inwardly inclined disposition for reducing centrifugal forces. | 1 |
[0001] This application claims the benefit of the Korean Application No. P2003-0021949 filed on Apr. 8, 2003, which is hereby incorporated by reference.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention relates to a water heating apparatus, and more particularly, to a water heating apparatus having a hot water supply tube provided with a heat exchanger having a maximized heat transfer area and a refrigerator having the same.
[0004] 2. Description of the Related Art
[0005] Hot water may be obtained from a conventional refrigerator. A method of generating hot water from the conventional refrigerator is disclosed in Korea utility model laid open publication No. 119072 (Mar. 12, 1998). In the above prior art, drinking water fed externally is heated by heat emitted from a condenser, stored in a hot storage tank and taken when necessary.
[0006] As anther method of generating hot water, there is Korea Patent laid open publication No. 199980 (Mar. 8, 1999). In the above method, heater is installed outside water supply tube, and drinking water is heated by heater, stored in a hot storage tank and taken when necessary.
[0007] However, since the refrigerators according to the related arts store hot water in hot water storage tank and then use it, it has various disadvantages in that its use is very inconvenient, sanitation is poor and maintenance and repair are difficult.
[0008] In other words, once hot water stored in the hot water storage tank is taken in excess of a predetermined amount, water is again heated to generate hot water. This is inconvenient since users have to wait for a long time until the generated hot water is stored in the hot water storage tank.
[0009] If the users use the refrigerator for a long term period, foreign material is deposited on the hot water storage tank and thus the hot water stored in the hot water storage tank is spoiled to deteriorate sanitation. To this end, it is necessary to clean up the hot water storage tank periodically to get rid of the foreign material deposited on the hot water storage tank, which provides a difficulty to maintain and repair the refrigerator.
[0010] Also, an auxiliary heat source is needed additionally so as to generate hot water due to limitations in heat capacitance and heat transfer area of condenser or heater.
SUMMARY OF THE INVENTION
[0011] Accordingly, the present invention is directed to a water heating apparatus and a refrigerator having the same that substantially obviate one or more problems due to limitations and disadvantages of the related art.
[0012] An object of the present invention is to provide a water heating apparatus in which hot water is fed without a time delay by installing a heat exchanger at a hot supply tube; the heat exchanger having a maximized heat transfer area in heat exchange from and to a heater.
[0013] Another object of the present invention is to provide a water heating apparatus in which hot water generated in a hot water supply tube is taken such that foreign material is not deposited, thereby improving sanitation and making easy maintenance and repair.
[0014] A further object of the present invention is to provide a water heating apparatus in which hot water is generated through a heat exchanger having a maximized heat transfer area in heat exchange from and to heater and thereby an auxiliary heat source is not installed additionally.
[0015] Additional advantages, objects, and features of the invention will be set forth in part in the description which follows and in part will become apparent to those having ordinary skill in the art upon examination of the following or may be learned from practice of the invention. The objectives and other advantages of the invention may be realized and attained by the structure particularly pointed out in the written description and claims hereof as well as the appended drawings.
[0016] To achieve these objects and other advantages and in accordance with the purpose of the invention, as embodied and broadly described herein, a water heating apparatus comprises: a case defining a body; a hot water supply tube having an heat exchanger installed in the case; a heat storage liquid material received in the case; and a heater installed in the case, for heating the heat storage liquid material.
[0017] The heat exchanger has a shape to maximize a heat transfer area and is comprised of a wound wire.
[0018] Preferably, the wound wire of the heat exchanger has a spiral shape, and is comprised of a plurality of turns spaced apart by an interval from each other.
[0019] It is further preferable that the heat storage liquid material is material having a high specific heat such as water or paraffin.
[0020] The case is illustrated and described to have a cylindrical shape in this specification but is not limited by the shape. The size and shape of the case depend on the space structure in which the case is installed, the longitudinal length of the heat exchanger and the winding shape of the wound wire.
[0021] Preferably, the case has an inner surface coated with ceramic so as to prevent corrosion and improve heat resistant property and an outer surface covered with adiabatic material such as glass fiber or synthetic resin so as to prevent heat from emitting to exterior.
[0022] The hot water supply tube is further desirably comprised of a copper tube or a stainless tube to enhance corrosion prevention and heat conductivity from the heater.
[0023] The heater is installed in a longitudinal direction of the heat exchanger in the case.
[0024] The heater is preferably installed in a space defined between a center axis of the case and the heat exchanger, and it is further preferable that the heater is a seizing heater.
[0025] The water heating apparatus further comprises a temperature sensor installed in the case, for sensing temperature of the heat storage liquid material; and a microcomputer for turning the heater on/off depending on the temperature sensed by the temperature sensor.
[0026] In another aspect of the present invention, a refrigerator comprises: a body defining an outer shell; a water supply tube installed in the body to connect to external water pipe; a hot water supply tube branched from the water supply tube and having an heat exchanger at a predetermined portion; a cold water supply tube branched from the water supply tube; a case installed to surround a heat exchanger of the hot water supply tube; a heat storage liquid material received in the case; and a heater installed in the case, for heating the heat storage liquid material.
[0027] It is to be understood that both the foregoing general description and the following detailed description of the present invention are exemplary and explanatory and are intended to provide further explanation of the invention as claimed.
BRIEF DESCRIPTION OF THE DRAWINGS
[0028] The accompanying drawings, which are included to provide a further understanding of the invention and, are incorporated in and constitute a part of this application, illustrate embodiment(s) of the invention and together with the description serve to explain the principle of the invention. In the drawings:
[0029] [0029]FIG. 1 is a schematic view illustrating a refrigerator that has a water heating apparatus according to an embodiment of the present invention; and
[0030] [0030]FIG. 2 is a schematic view illustrating a water heating apparatus according to an embodiment of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
[0031] Reference will now be made in detail to the preferred embodiments of the present invention, examples of which are illustrated in the accompanying drawings.
[0032] As shown in FIG. 1, a refrigerator having a water heating apparatus according to an embodiment of the present invention, includes a body 1 defining an outer shell, a door 2 formed in the front of the body 1 , a water supply tube 10 installed in the body 1 so as to be connected with an external water pipe (not shown), a hot water supply tube 40 branched from the water supply tube 10 and having a heat exchanger at a predetermined portion, a cold water supply tube 50 branched from the water supply tube 10 .
[0033] A filter 20 for filtering the water fed from an exterior and removing foreign material from the water is installed on the water supply tube 10 . Three-way valve 30 for controlling the water flow direction is installed on a branch portion of the water supply tube 10 , which is branched from the water supply tube 10 to the hot water supply tube 40 and the cold water supply tube 50 .
[0034] A hot water supply unit 60 for supplying hot water depending on operation of a hot water supply control lever 65 is installed at an end of the hot water supply tube 40 . A cold water supply unit 70 for supplying hot water depending on operation of a cold water supply control lever 75 is installed at an end of the cold water supply tube 50 .
[0035] Meanwhile, as shown in FIG. 2, a water heating apparatus 100 is arranged on the hot water supply tube 40 . The hot water heating apparatus 100 includes a heat exchanger 40 a provided with a wire wound on a portion of the hot water supply tube 40 to maximize heat transfer area, a case 110 installed to surround a heat exchanger 40 a of the hot water supply tube, a heat storage liquid material 120 received in the case 110 , and a heater 130 installed in the case 110 , for heating the heat storage liquid material 120 .
[0036] A temperature sensor 140 for sensing temperature of the heat storage liquid material 120 is installed in the case 110 . A microcomputer (not shown) for turning the heater 130 on/off depending on the temperature sensed by the temperature sensor 140 is installed in the refrigerator body 1 to control the temperature of the heat storage liquid material 120 more easily.
[0037] In the meanwhile, it is desirable that the wound wire of the heat exchanger 40 a has a spiral shape and the turns of the wire are spaced apart from each other.
[0038] It is further desirable that the heat storage liquid material 120 is of material having a high specific heat such as water or paraffin.
[0039] The case 110 is illustrated and described to have a hollow cylindrical shape in this specification but is not limited only to the shape. The size and shape of the case 110 depend on the space structure of the refrigerator body 1 , the longitudinal length of the heat exchanger 40 a and the winding shape of the wound wire.
[0040] Preferably, an inner surface of the case 110 is coated with ceramic to prevent corrosion and improve heat resistant property and an outer surface of the case 110 is covered with adiabatic material such as glass fiber or synthetic resin to prevent heat from emitting to exterior.
[0041] Further, the hot water supply tube 40 is preferably of a copper tube or a stainless tube to prevent corrosion and enhance heat conductivity from the heater 130 .
[0042] The heater 130 is installed in the case 110 , particularly, in a space formed in the heat exchanger 40 a in a longitudinal direction. More preferably, the heater 130 is a seizing heater.
[0043] The hot water supply process of the refrigerator that has a water heating apparatus 100 according to an embodiment of the present invention configured as described above will be described now.
[0044] In a hot water standby state, drinking water is fed from an external water supply pipe to the water supply tube 10 , filtered through the filter 20 to get rid of foreign material, and fed to the hot water supply tube 40 through the three-way valve 30 .
[0045] Microcomputer controls the heater 130 to heat the heat storage liquid material 120 , and the heated heat storage liquid material 120 heats the heat exchanger 40 a.
[0046] At this time, the water fed to the hot water supply tube 40 is rapidly heated while passing through the heat exchanger 40 a.
[0047] The temperature sensor 140 senses the temperature of the heat storage liquid material 120 continuously. At this time, the microcomputer compares actual temperature and set temperature of the heat storage liquid material 120 .
[0048] If the actual temperature of the heat storage liquid material 120 is higher than the set temperature, the microcomputer turns the heater 130 off. If the actual temperature of the heat storage liquid material 120 is lower than the set temperature, the microcomputer turns the heater 130 on. The microcomputer repeats the above-mentioned process to maintain the temperature of the hot water stored in the heat exchanger 40 a to be constant.
[0049] Next, the actual supply process of the hot water generated as described above will be described.
[0050] As described above, in the hot water standby state, if a user operates the hot water supply operation lever 65 of the hot water supply unit 60 provided in the front of the refrigerator door 2 , the hot water stored in the heat exchanger 40 a is fed to the user through the hot water supply unit 60 without a delay.
[0051] The drinking water additionally fed to the hot water supply tube 40 by an amount of hot water fed to the user through the hot water supply tube 40 is rapidly heated while passing through the heat exchanger 40 a so that the user can get the desirable amount of the hot water.
[0052] In other words, the heat exchanger 40 a whose heat transfer area is maximized is formed on the hot water supply unit 40 so that the water passing through the heat exchanger 40 a is rapidly heated owing to heat exchange with the heat storage liquid material 120 and fed to the user.
[0053] On the other hand, the heater 130 is turned on/off with a predetermined interval without installing the temperature sensor 140 to generate hot water and supply it to the user.
[0054] In other words, hot water can be fed to the user by repeating steps of turning the heater 130 on for a predetermined time to heat the heat exchanger 40 a through the heat storage liquid material 120 and generate hot water and then turning the heater 130 off for a predetermined time.
[0055] Here, the on/off time of the heater 130 can be adjusted to efficiently generate hot water and supply it to the user.
[0056] Additionally, in a feed of cold water, drinking water is fed even to the cold water supply tube 50 and is cooled while passing through the cold water supply tube 50 branched to an evaporator (not shown). So, the cooled water is received in the cold water supply tube 50 .
[0057] Accordingly, if the user operates the cold supply operation lever 75 of the cold water supply unit 70 provided in the front of the refrigerator door 2 , the cold water received in the cold supply tube 50 is rapidly fed to the user through the cold supply unit 70 .
[0058] The additional water fed to the cold supply tube 50 as much as the amount of the fed water is cooled while passing the cold water supply tube 50 branched to an evaporator. So, the user can take the cold water as he or she wants.
[0059] As a result, the fed water is rapidly heated using the water heating apparatus including the heat exchanger having the maximized heat transfer area with the heater on the hot water supply tube so that the user can take the hot water as he or she wants.
[0060] Since hot water can be generated and fed without installing any additional storage tank, foreign material is not deposited and the water is not spoiled.
[0061] Thus, since clean water is fed to the user, the sanitation is improved. It is easy to manage them since the user does not have to get rid of the foreign material.
[0062] Since hot water is generated by the heat exchanger that has the maximized heat transfer area with the heater, hot water can be fed without installing any additional auxiliary heat source.
[0063] It will be apparent to those skilled in the art that various modifications and variations can be made in the present 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. | The present invention relates to a water heating apparatus having a heat exchanger that has a maximized heat transfer area between a hot water supply tube and a heater so that clean hot water is continuously fed without a time delay. To achieve these objects, a water heating apparatus comprises: a case defining a body; a hot water supply tube having an heat exchanger installed in the case; a heat storage liquid material received in the case; and a heater installed in the case, for heating the heat storage liquid material. | 5 |
RELATED APPLICATION
[0001] This patent arises from a U.S. patent application which is (a) a continuation of International Patent Application Serial No. PCT/EP2003/009493, filed Aug.27, 2003, (b) a continuation of International Patent Application Serial No. PCT/EP2003/009483, filed Aug. 27, 2003, and (c) a continuation-in-part of U.S. patent application Ser. No. 10/956,562, filed on Oct. 1, 2004. U.S. patent application Ser. No. 10/956,562 is a continuation of International Patent Application Serial Number PCT/EP03/09490, which was filed on Aug. 27, 2003. International Patent Application Serial No. PCT/EP2003/009493, International Patent Application Serial No. PCT/EP2003/009483, International Patent Application Serial Number PCT/EP03/09490, and U.S. patent application Ser. No. 10/956,562 are all hereby incorporated herein by reference in the entirety.
FIELD OF THE DISCLOSURE
[0002] This disclosure relates generally to handheld firearms, and more particularly, to firearms employing gas pressure loading mechanisms.
BACKGROUND
[0003] Throughout this patent, position designations such as “above,” “below,” “top” “forward,” “rear,” etc. are referenced to a firearm held in a normal firing position (i.e., pointed away from the shooter in a generally horizontal direction).
[0004] As used in this patent, “large caliber” denotes a rifle with a caliber or greatest case diameter of the cartridge of more than 15 mm. With large caliber rifles, a heavy projectile (for example, a bullet, an adapter base projectile, a charge of shot, a gas body or the like) is shot at a rather low speed compared with other, small caliber high-performance rifles. Consequently, the gas pressure is also comparatively low, particularly in the front region of the barrel.
[0005] In the case of a large caliber, gas-operated rifle whose cartridge diameter is above 15 mm, the breech is large and long, and hence heavy. As a result, the force required to reload it is also large. Since, as already mentioned, the gas pressure of such a rifle is low, the action area of the gas piston must be great. Accordingly the quantity of gas which is depleted from the barrel during firing is also large. For this reason, recoil-operated guns have usually been preferred. However, recoil-operated guns have the disadvantage of being particularly sensitive to the type of ammunition used.
[0006] In case of large caliber weapons, a central anchoring element upon which all occurring forces are supposed to impinge has recently been provided to save weight. To a large extent, when such a central anchoring element is employed, the weapon case can be designed in the lightest plastic style, since the weapon case is subjected to little stress because the stresses are largely absorbed by the central anchoring element. A gas piston which usually interacts with the gas cylinder requires an additional point of power input at the tapping point of the barrel. Consequently, it is rather heavy in construction.
[0007] Large caliber rifles are disadvantaged in that the rifle is built rather long, if it is constructed as an enlarged, normal caliber rifle.
BRIEF DESCRIPTION OF THE DRAWINGS
[0008] FIG. 1 is a longitudinal cross-sectional view through a rear barrel end of an example force receiving part and breech.
[0009] FIG. 2 is a perspective view of the example breech of FIG. 1 .
[0010] FIG. 3 is a schematic cross-sectional view through the example breech of FIG. 1 .
[0011] FIG. 4 is a horizontal cross-sectional view through the bolt head of FIG. 1 showing the bolt head in engagement with the rear part of a cartridge.
DETAILED DESCRIPTION
[0012] FIGS. 1-4 illustrate the breech of an example large caliber semi-automatic rifle. The example rifle of FIGS. 1-4 uses shell cartridges that have an overall length of about 90 mm, a case length less than 30 mm, and a caliber of 20 mm. FIGS. 1-4 illustrate the same weapon. The same reference numerals are used for the same structures throughout the figures.
[0013] The illustrated rifle has a barrel ( 101 ) which is inserted into a force receiving part ( 104 ). The rear end of the barrel ( 101 ) defines a cartridge chamber ( 103 ). The cartridge chamber ( 103 ) holds the cartridge case ( 165 ) of a cartridge ( 163 ).
[0014] The force receiving part ( 104 ) forms a central anchoring element. Thus, in addition to the barrel ( 101 ), a case, a sighting electronic unit, a sling carrier and/or an attachment (e.g., a grenade launcher, an automatic pistol, etc.) can be fastened to the force receiving part ( 104 ).
[0015] The force receiving part ( 104 ) defines an upper bore hole above the bore hole that receives the barrel ( 101 ). This upper bore hole includes two portions, namely, a front bore hole ( 167 ) and a rear bore hole ( 171 ). The front bore hole ( 167 ) has a smaller diameter than the rear bore hole ( 171 ). The front bore hole ( 167 ) is constructed to receive a breech-closing spring pipe or tube ( 169 ). The front bore hole ( 167 )joins into the rear bore hole ( 171 ), which forms a gas cylinder. The transition between the two bore holes ( 167 , 171 ) is beveled. This transition is connected to the barrel ( 101 ) by a gas intake bore hole ( 173 ). The gas intake bore hole ( 173 ) extends at a right angle to the barrel ( 101 ) and joins into the barrel ( 101 ) at the end of the cartridge chamber ( 103 ).
[0016] A pipe or tube is placed in the two bore holes ( 167 , 171 ). The pipe includes two cylindrical pipe sections with different diameters, namely, a breech-closing spring pipe ( 169 ) and a gas piston ( 175 ). The breech-closing spring pipe ( 169 ) is adjustable, and acts as a seal in the bore hole ( 167 ). The gas piston ( 175 ) is adjustable, and acts as a seal in the gas cylinder ( 171 ). The recess between the two pipe sections ( 169 ), ( 175 ) forms the active area of the gas piston ( 175 ). The gas piston ( 175 ) is extended to the rear in a single piece, namely, as a bolt head carrier ( 113 ).
[0017] The pipe ( 169 ), the gas piston ( 175 ) and the bolt head carrier ( 113 ) together comprise a movable component. This movable component defines a breech-closing spring locating bore hole ( 177 ) to the rear. The breech-closing spring locating bore hole ( 177 ) is a blind hole which is open to the rear and closed to the front. This bore hole ( 177 ) receives a breech-closing spring (not shown), which is supported behind the illustrated arrangement in the breech.
[0018] A firing lever (not shown) is coupled to the front side of the breech-closing spring pipe ( 169 ). This firing lever may be used to move the entire component ( 169 , 175 , 113 ) back against the force of the breech-closing spring.
[0019] When the cartridge ( 163 ) in the cartridge chamber ( 103 ) is fired, powder gases penetrate through the gas intake bore hole ( 173 ) into the gas cylinder ( 171 ). The gases press the entire movable component ( 169 , 175 , 113 ) to the rear against the force of the breech-closing spring via the gas piston ( 175 ).
[0020] The bolt head carrier ( 113 ) can be moved back either by hand or automatically. The bolt head carrier ( 113 ) travels a straight-line path of motion, which runs parallel to the center line of the barrel ( 101 ). Longitudinal grooves in the case, (not shown), guide the bolt head carrier ( 113 ) together with the breech-closing spring pipe ( 169 ) and gas piston ( 175 ) in the gas cylinder ( 171 ) in the force receiving part ( 104 ).
[0021] A bolt head ( 111 ) is located behind the barrel ( 101 ) and under the bolt head carrier ( 113 ). This bolt head ( 111 ) can be moved back and forth together with the bolt head carrier ( 113 ). However, the bolt head ( 111 ) cannot be moved alone. The movement distance of the bolt head ( 111 ) is longer than the length of a cartridge ( 163 ). The movement of the bolt head ( 111 ) is guided by longitudinal grooves or cross-pieces in the case.
[0022] The bolt head ( 111 ) is penetrated by a locking bolt ( 125 ). The locking bolt ( 125 ) has the shape of a vertical letter “T.” The vertical beam of the locking bolt ( 125 ) passes through a vertical bore hole ( 121 ) in the bolt head ( 111 ). This vertical beam terminates below in a locking extension ( 107 ). Each of the opposite ends of the horizontal beam of the “T” defines a locking finger ( 108 ). In the middle, the horizontal beam has a coupling projection ( 183 ) extending to the rear.
[0023] As shown in FIG. 3 , three recesses are defined in the force receiving part ( 104 ) for receiving corresponding parts of the locking bolt ( 125 ). One of the recesses is a lower, locking recess ( 105 ). The lower locking recess ( 105 ) comprises a conical bore hole. The middle of the bore hole lies on a vertical axis which passes through the center line of the barrel ( 101 ). The other two recesses are locking notches ( 106 ) symmetrically placed on opposite side of the vertical axis that passes through the locking recess ( 105 ). The locking notches ( 106 ) are seated in front of projections of the inner surface of the force receiving part ( 104 ).
[0024] When the locking bolt ( 125 ) is located in the lower position shown in FIG. 1 (i.e., the locking position), the locking extension ( 107 ) engages in the locking recess ( 105 ), and the locking fingers ( 108 ) engage in the locking notches ( 106 ). The bolt head ( 111 ) is then rigidly locked in the force receiving part ( 104 ). This is the locking position of the locking bolt ( 125 ).
[0025] When the locking bolt ( 125 ) is raised, the locking extension ( 107 ) lifts out of the locking recess ( 105 ) and the locking fingers ( 108 ) lift out of the locking notches ( 106 ). This is the unlocked position of the locking bolt ( 125 ). When the locking bolt ( 125 ) is in the unlocked position, the bolt head ( 111 ) is unlocked and can move to the rear.
[0026] A firing pin ( 119 ) passes through an oblong hole ( 131 ) in the locking bolt ( 125 ). This oblong hole ( 131 ) permits unhindered movement of the locking bolt ( 125 ) between the locked position and the unlocked position. The firing pin ( 119 ) is oriented horizontally and centrally relative to the barrel ( 101 ).
[0027] As can be seen in FIG. 4 , the firing pin ( 119 ) has a bulge ( 129 ). The rear side of the oblong hole ( 131 ) in the locking bolt ( 125 ) has a beveled edge ( 133 ) that extends from the rear and the bottom to the top and the front. This beveled edge allows the firing pin ( 119 ) to penetrate into the locking bolt ( 125 ) from the rear when the locking bolt is in the locked position shown in the FIG. 1 . However, when the locking bolt ( 125 ) moves up to its unlocked position, then the beveled edge ( 133 ) of the locking bolt ( 125 ) moves the bulge ( 129 ) of the firing pin ( 119 ) (and, thus, the firing pin ( 119 ) itself) to the rear. Consequently, the firing pin can only reach its front most position when the locking bolt ( 125 ) is in its locked position. As a result, a cartridge ( 163 ) may only be fired when the locking bolt ( 125 ) is in its locked position.
[0028] The use of the beveled edge ( 133 ) and the bulge ( 129 ) to control the position of the firing pin ( 119 ) eliminates the need for the firing pin spring required by other weapons in the prior art.
[0029] A cross shaft ( 189 ) is provided in the bolt head ( 111 ) behind the locking bolt ( 125 ). An axial tilting lever ( 187 ) is pivotably mounted on this cross shaft ( 189 ). One leg of this tilting lever ( 187 ) engages the coupling projection ( 183 ) of the locking bolt ( 125 ). The other leg of this tilting lever ( 187 ) ascends to the bottom of the bolt head carrier ( 113 ).
[0030] A descending locking projection ( 185 ) is located in front of this ascending leg of the tilting lever ( 187 ). The front side of the locking projection ( 185 ) has a beveled edge ( 193 ) that extends upward toward the top and front. This arrangement functions in the following manner. In the locked position of the breech bolt ( 125 ) (lower position), the bolt head carrier ( 113 ) is in the front most position. The locking projection ( 185 ) is seated above the locking bolt ( 125 ) and, thus, prevents the locking bolt ( 125 ) from being removed from its lowered position. The location of the tilting lever ( 187 ) in this state can be seen in FIG. 1 .
[0031] Now, if the bolt head carrier ( 113 ) is moved to the rear by hand or through gas pressure, the locking projection ( 185 ) also moves to the rear, thereby freeing the locking bolt ( 125 ) for upward movement. Simultaneously, the locking projection ( 185 ) runs into the vertical leg of the tilting lever ( 187 ) and rotates it (clockwise in the drawing). As a result, the horizontal leg of the tilting lever ( 187 ) lifts the coupling projection ( 183 ) and, consequently, the locking bolt ( 125 ). The upper part of the locking bolt ( 125 ) engages in a coupling groove ( 191 ), which is constructed at the bottom side of the bolt head carrier ( 113 ) in front of the bevel ( 193 ). Simultaneously, the locking projection ( 185 ) runs over the upper leg of the tilting lever ( 187 ) and thereby keeps the tilting lever ( 187 ) tilted, so that the tilting lever ( 187 ) keeps the locking bolt ( 125 ) in the upper position, (i.e., engaged in the groove ( 191 )). Consequently, the locking bolt ( 125 ) follows the motion of the bolt head carrier ( 113 ) to the rear. Since the locking bolt ( 125 ) remains engaged in the bolt head ( 111 ), the bolt head ( 111 ) also follows the motion of the bolt head carrier ( 113 ) to the rear. In this process, a case formation (not shown) engages the locking bolt ( 125 ) from below and prevents it from falling down.
[0032] To load and fire the next round, the bolt head carrier ( 113 ) must return to the front where the bolt head ( 111 ) contacts the rear of the barrel ( 101 ). To lock the breech, the parts ( 107 , 108 ) of the locking bolt ( 125 ) must drop down into the corresponding recesses ( 105 , 106 ) of the power intake part ( 104 ). This downward movement is forced by the beveled edge ( 193 ) of the locking projection ( 185 ). In particular, this beveled edge ( 193 ) cams the locking bolt ( 125 ) downward as the bolt head carrier ( 113 ) moves forward. Simultaneously, the rear side of the locking projection ( 185 ) releases the tilting lever ( 187 ) so that it can pivot upward again into the position shown in FIG. 1 . When the locking block ( 125 ) moves into the position of FIG. 1 , the bolt head ( 111 ) is locked. When the locking bolt ( 125 ) is located in its bottom position (see FIG. 1 ), the beveled edge ( 133 ) of the locking bolt ( 125 ) releases the firing pin ( 119 ) for firing of a shot. The weapon is now ready to fire, if there is a cartridge ( 163 ) in the cartridge chamber ( 103 ). (Prior to locking, as the bolt head carrier ( 113 ) moves forward, the gas piston ( 175 ) (which, in the illustrated example, is constructed in one piece with the bolt head carrier ( 113 )) runs into the front end of the gas cylinder ( 171 )).
[0033] In the illustrated example, the length of the cartridge case ( 165 ) is less than one third of the total return motion of the breech ( 111 , 113 ). As a result, the cartridge case ( 165 ) is completely removed from the cartridge chamber ( 103 ), even before the breech ( 111 , 113 ) has been appreciably slowed by the breech-closing spring. Further, the acceleration phase of the breech ( 111 , 113 ) is already completed, since the barrel ( 101 ) must be practically pressure-less by the time the cartridge case ( 165 ) is completely removed.
[0034] In order to support the cartridge case ( 165 ), the breech block ( 181 ) of the bolt head ( 111 ) is provided with support extensions ( 195 ) at the top and at the bottom. Lateral support of the cartridge case ( 165 ) is more difficult to guarantee.
[0035] Referring to FIG. 4 , a horizontal cross-section through the center of the bolt head ( 111 ) is shown. The bolt head ( 111 ) has, on both sides and symmetrical to one another, two slot-shaped recesses ( 110 a , 110 b ), which run to the rear through a spring bore hole ( 197 ). An extractor hook ( 161 ) is inserted in one of the recesses ( 110 a ). A spring (not shown) in the associated spring bore hole ( 197 ) acts on the extractor hook ( 161 ) via a tappet. The extractor hook ( 161 ) can be pivoted around a vertical axis. A supporting body ( 199 ) is seated in the other recess ( 110 b ). The supporting body ( 199 ) is also mounted on a vertical axis. This supporting body ( 199 ) is similar to the extractor hook ( 161 ), but it is a bit larger, so that it cannot move in the recess ( 110 b ). Moreover, unlike the extractor hook ( 161 ), the supporting body ( 199 ) does not encompass the cartridge base of a cartridge ( 163 ) located in the cartridge chamber ( 103 ). To reverse the ejection direction, it is merely necessary to exchange the extractor hook ( 161 ) with the spring for the supporting body ( 199 ), and to change the ejector (not shown) from one side of the weapon to the other.
[0036] From the foregoing, persons of ordinary skill in the art will appreciate that semi-automatic rifles for large caliber shell cartridges with a long cartridge length and short cartridge case have been disclosed. The disclosed rifles are light and reload reliably. For example, a large caliber gas-operated rifle with a central force receiving part ( 104 ) that holds the rear end of a barrel ( 1 ) and the locking abutments of a breech is disclosed above.
[0037] A disclosed example rifle includes a gas intake opening ( 173 ) defined in the force receiving part ( 104 ) and in the barrel ( 101 ). A gas cylinder ( 171 ) is firmly joined with the force receiving part ( 104 ). The gas intake opening is in communication with the barrel ( 1 ) and the gas cylinder ( 171 ). Having the gas intake opening ( 173 ) in the force receiving part ( 104 ) makes a separate, power absorbing enclosure for the gas intake opening unnecessary. Furthermore, the gas intake opening ( 173 ) is placed far to the rear, where the gas pressure is sufficient for unlocking and operating even a heavy breech with a long reloading path.
[0038] In the illustrated example, the barrel ( 101 ) of the weapon is preferably provided, as is generally the practice, with a cartridge chamber ( 103 ) that is constructed in one piece with the barrel ( 101 ). However, it is also conceivable that the cartridge chamber ( 103 ) be separate from the barrel ( 101 ). As used herein, the term “barrel” includes the cartridge chamber ( 103 ), whether it is constructed in one piece with the barrel ( 101 ) or separate from the barrel ( 101 ).
[0039] In the illustrated example, the gas intake opening ( 173 ) is located near the front end of the cartridge chamber ( 103 ). The gas intake opening ( 173 ) is in communication with a bore hole in the force receiving part ( 104 ), which is, in turn, in communication with the front end of the gas cylinder ( 171 ). In the case of extremely large caliber rifles, the cartridge chamber ( 103 ) is often rather short compared with the caliber of the barrel ( 101 ). In the case of shell cartridges like those described above, the cartridge chamber ( 103 ) is extremely short. Thus, slow acceleration of the breech by the discharge gases is sufficient to ensure that the projectile has left the barrel prior to the opening of the breech. With large caliber rifles, the pressure decrease usually occurs so prematurely that the excess pressure in the barrel ( 101 ) is rather low when the projectile leaves the barrel ( 101 ). The illustrated example does not use a conventional pipe or similar component. The force receiving part ( 104 ) ensures that even a high pressure in its bore is harmlessly received and passed on to the gas cylinder ( 171 ). This gas cylinder ( 171 ) is preferably constructed in the force receiving part ( 104 ) and, consequently, does not require its own power absorbing component.
[0040] The bore ( 173 ) can extend diagonally either in the direction of fire or opposite the direction of fire in order to utilize or inhibit the kinetic energy of the discharge gases. Since the kinetic energy at the end of the chamber ( 103 ) is quite low, it is preferred that the bore hole ( 173 ) extends at a right angle to the direction of fire. This permits the force receiving part ( 104 ) to be kept as compact as possible.
[0041] The gas cylinder ( 171 ), which directly connects to the bore ( 173 ), can be seated laterally or underneath the cartridge chamber ( 103 ). However, in order to avoid excessively extending the width of the weapon and to be able to mount a magazine under the breech, it is preferred that the gas cylinder ( 171 ) be seated above the cartridge chamber ( 103 ). Constructing the gas cylinder ( 171 ) in the force receiving part ( 104 ) above the cartridge chamber enables a weapon style that is very stout, and that has a short length in the longitudinal direction.
[0042] The breech of the illustrated example is, as usual, formed from a bolt head ( 111 ) and a bolt head carrier ( 113 ). To make a regulator for the bolt head carrier ( 113 ) unnecessary, and to keep the style of the weapon short in spite of the gas cylinder ( 171 ) being located far in the rear, the bolt head carrier ( 113 ) of the illustrated example forms the gas piston.
[0043] Similar to a semi-automatic shotgun with a tube magazine, where the gas piston surrounds the magazine tube, in the illustrated example, it is preferred that a pipe ( 175 ) be firmly joined to the bolt head carrier ( 113 ); that the pipe ( 175 ) penetrates the gas cylinder ( 171 ); and that the pipe ( 175 ) emerges to the front of the force receiving part ( 104 ) as an attachment pipe ( 169 ) for a breech-closing spring. The inner surface of the gas cylinder ( 175 ) has an annular-shape. Moreover, the gas discharge force occurs precisely centrally on the bolt head carrier ( 113 ). The pull-back spring for the breech, (i.e., the so-called “breech-closing spring”), passes through the pipe ( 169 ), so that the bolt head carrier ( 113 ) forming the gas piston ( 175 ) can also be reset precisely centrally and, consequently, cannot jam. As a result, the diameter of the gas cylinder ( 171 ) can be built shorter than would otherwise be possible.
[0044] In some examples, the pipe ( 169 , 175 ) carries a loading handle, which is either mounted to the pipe ( 169 , 175 ) or can be attached or joined to it. This handle is used for reloading.
[0045] Persons of ordinary skill in the art will recognize that there are various conventional means of locking a breech. For example, lateral locking shutters or locking lugs mounted in a circle around the longitudinal center of the barrel are known. However, the shutters are applied off center, while lugs involve a backward motion of the bolt head, which increases the overall length of the rifle, even if only slightly. Therefore, in an illustrated example, a locking bolt ( 125 ) penetrates transversely through the bolt head ( 111 ) and is pressed into a safety position by the bolt head carrier ( 113 ) when the bolt head carrier ( 113 ) is in its resting position. When the locking bolt ( 125 ) is in the safety position, it engages in recesses ( 105 , 106 ) of the force receiving part ( 104 ) and, as a result, it locks the bolt head ( 111 ). The recesses ( 105 , 106 ) are advantageously disposed somewhat circular-symmetrically to the longitudinal axis of the barrel. To unlock the bolt head ( 111 ), the bolt head ( 111 ) does not have to travel an unlocking distance, but instead the locking block ( 25 ) is simply pulled out at a right angle to the longitudinal axis of the barrel ( 101 ). The device that move the locking block ( 125 ) can be located above the bolt head ( 111 ) and, thus, does not take up any overall length.
[0046] Preferably, a tilting lever ( 187 ) is provided to assist in the unlocking. The tilting lever ( 187 ) is arranged in the bolt head ( 111 ). One end of the tilting lever ( 187 ) engages in the path of motion of the bolt head carrier ( 113 ). The opposite end of the tilting lever ( 187 ) engages in the path of motion of the locking bolt ( 125 ). When the bolt head carrier ( 113 ) moves back, it rotates the tilting lever ( 187 ) to thereby pull the locking bolt ( 125 ) out of the recesses ( 105 , 106 ) of the force receiving part ( 104 ). The tilting lever ( 187 ) is pivoted, for example, on a swiveling axis ( 189 ) which is transversely arranged in the bolt head ( 111 ). However, the tilting lever ( 187 ) may alternatively be replaced by a pressure spring which forces the locking bolt ( 125 ) out of the recesses ( 105 , 106 ) when the bolt head carrier ( 113 ) has moved back sufficiently to permit the upper part of the locking bolt ( 125 ) to enter the coupling groove ( 191 ).
[0047] Additionally it is preferred that the locking bolt ( 125 ) engages in the bolt head carrier ( 113 ) when the locking bolt ( 125 ) is in the unlocked position so that the locking bolt ( 185 ) and the bolt head ( 111 ) move with the bolt head carrier ( 113 ). In the illustrated example, a positive connection is created between the bolt head ( 111 ) and the bolt head carrier ( 113 ) via the locking bolt ( 125 ), regardless of how quickly the bolt head carrier ( 113 ) moves rearward. Thus, for example, the positive connection is formed even in the case of slow reloading.
[0048] Preferably the locking bolt ( 125 ) defines an oblong hole ( 131 ) through which the firing pin ( 119 ) passes. The firing pin ( 119 ) has a bulge ( 129 ) behind the locking bolt ( 125 ). The oblong hole ( 131 ) has a beveled edge ( 133 ) to the rear, which engages on the bulge ( 129 ) of the firing pin ( 119 ) and pushes it back when the locking bolt ( 125 ) is pulled out of engagement with the recesses ( 105 , 106 ) of the force receiving part ( 104 ), (i.e. when it is unlocked). Thus, after a shot, the firing pin ( 119 ) is forcefully pushed out of engagement with the cartridge ( 103 ) and cannot reach the cartridge base as long as the breech is unlocked. Consequently, a burst blasting cap (i.e., a so-called primer failure) cannot keep the firing pin ( 119 ) to the front, and a premature firing cannot take place when the bolt head ( 111 ) is not yet locked. This guarantees reliability and safety, even in the case of rare malfunctions.
[0049] Normally a bolt head ( 111 ) has only one extractor. However, providing two extractors is also known. As discussed in detail above, the illustrated bolt head ( 111 ) employs one extractor element ( 161 ) and one supporting element ( 199 ). In this example, there are two recesses ( 110 a , 110 b ) in the bolt head ( 111 ) on opposite sides of the locking bolt ( 125 ). The rear of one of the recesses ( 110 b ) is in communication with a bore hole. The rear of the other one of the recesses ( 110 a ) is in communication with a bore hole for a set-bolt and a spring ( 197 ). An extractor ( 161 ) is located in one of the recesses ( 110 a ). The extractor ( 161 ) can be swiveled against the force of the spring as transferred by the set-bolt. A supporting element ( 199 ) is inserted in the opposite recess ( 110 b ). The supporting element ( 199 ) is located opposite the extractor ( 161 ), and laterally supports the base of a cartridge ( 163 ) or cartridge case ( 165 ). The extractor ( 161 ) and the supporting element ( 199 ) face one another.
[0050] The supporting element ( 199 ) supports the cartridge case ( 165 ) after the extraction, so that the cartridge case ( 165 ) does not slip from the opposing extractor hook ( 161 ). After the shot, the breech first undergoes an acceleration phase and then a deceleration phase. During the deceleration phase, the base of the accelerated cartridge case rests firmly on the breech block ( 181 ). The front area of the bolt head ( 111 ) is called the “breech block.”
[0051] The spring, set-bolt and extractor ( 161 ) on one side and the supporting element ( 199 ) on the opposite side can, if desired, be exchanged to change the direction of cartridge ejection.
[0052] However, in the case of the shell cartridges discussed *above, the cartridge case is very short. As a result, the shell case could possibly leave the cartridge chamber during the acceleration phase or shortly after the acceleration phase. Since the supporting element ( 199 ) and the extractor ( 161 ) are seated in recesses ( 110 a , 110 b ) of the same type, they can be interchanged. In this manner, it is possible to rearrange the ejection direction of the rifle so that the rifle can be easily adapted to right-handed shooters or left-handed shooters.
[0053] Example gas pressurized loading devices are described in U.S. patent application Ser. No. ______ (Attorney Docket No. 20020/10047), which is incorporated in its entirety herein by reference. Example cartridge ejection arrangements are described in U.S. patent application Ser. No. ______ (Attorney Docket No. 20020/10056), which is hereby incorporated herein by reference in its entirety.
[0054] Although certain example, methods, apparatus and articles of manufacture have been described herein, the scope of coverage of this patent covers all methods, apparatus and articles of manufacture fairly falling within the scope of the appended claims either literally or under the doctrine of equivalents. | Firearms employing gas pressure loading mechanisms are disclosed. An example firearm includes a central force receiving component containing a gas cylinder, and a barrel in communication with a cartridge chamber received in the force receiving component. The cartridge chamber is in communication with a gas withdrawal opening and is sized to fire cartridges having a caliber of at least 15 mm. The firearm also includes a bore in communication with the gas withdrawal opening and the gas cylinder. Further, the firearm includes a locking block having a locked position and an unlocked position. The locking block engages the central force receiving component when the locking block is in the locked position. | 5 |
CROSS-REFERENCE APPLICATION
The present application is a divisional application of U.S. Appl. No. 09/706,810, filed Nov. 7, 2000 (now U.S. Pat. No. 6,525,370), which is a divisional application of 09/317,255, filed May 24, 1999 (now abandoned), which it a divisional application of 08/720,014, filed Sep. 27, 1996 (now U.S. Pat. No. 5,925,907).
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention generally relates to a semiconductor device including a transistor with a composite gate structure and a transistor with a single gate structure, and to a method for manufacturing such a semiconductor device. More specifically, the present invention relates to a nonvolatile semiconductor memory device including a nonvolatile memory cell having a composite gate structure of a floating gate and a control gate, and a transistor having a single gate structure of only a control gate, and also a method for manufacturing such a nonvolatile semiconductor memory device.
2. Description of the Related Art
Among nonvolatile semiconductor memory devices in which information stored therein can not be erased even when power sources are turned OFF, the information can be electrically written into the respective memory cells of EPROMs (Electrically Programmable Read-Only Memories), whereas the information can be electrically written into the respective memory cells as well as can be electrically erased from each of these memory cells in EEPROMs (Electrically Erasable Programmable Read-Only Memories).
In general, as a memory cell for such an EPROM and an EEPROM, a MOS transistor with a composite gate structure is employed. The composite gate structure is constituted by stacking a floating gate electrode and a control gate electrode which are made of polycrystalline silicon films with an insulating film interposed therebetween. On the other hand, as a gate electrode of a single gate structure of another MOS transistor other than the memory cell transistor formed in, for example, a peripheral circuit region, two layers of polycrystalline silicon films, which are made simultaneously with forming of the floating gate and the control gate of the memory cell transistor, are utilized so that the steps in manufacturing of the transistor can be simplified. Such a semiconductor memory device structure is disclosed in, for instance, JP-A-59-74677, JP-A-7-183411, and JP-A-548046.
In JP-A-59-74677, the composite gate containing the floating gate and the control gate of the memory transistor, and the single gate structure of the peripheral transistor are both formed by three layers of a first polycrystalline silicon film, an insulating film, and a second polycrystalline silicon film, wherein in the peripheral transistor, the first polycrystalline silicon film is electrically connected via an opening fabricated in the insulating film to the second polycrystalline silicon film in an integral form, so as to provide a structure essentially identical to the gate of the single layer structure. However, the steps in manufacturing the memory device of JP-A-59-74677 would be complicated, since the opening must be formed at a preselected place of the insulating film located between the first polycrystalline silicon film and the second polycrystalline silicon film, which constitute the gate electrode of the peripheral transistor.
In JP-A-7-183411 and JP-A-5-48046, it is disclosed to form the floating gate and the control gate of a memory cell transistor by stacking successively the first polycrystalline silicon film, silicon oxide film and the second polycrystalline silicon film and to form the control gate of the peripheral transistor by stacking the second polycrystalline silicon film directly on the first polycrystalline silicon film. In such a case that the composite gate of the memory cell transistor and the gate electrode of the peripheral transistor are both formed of a lamination of the first and second polycrystalline silicon films, it is required to introduce an impurity such as phosphorous into the first and second polycrystalline silicon films thereby reducing the resistance of the films, since the films are also used as wiring layers. However, any of JP-A-7-183411 and JP-A-5-48046 describes nothing about this matter.
On the other hand, JP-A-2-3289 discloses a composite gate of the memory transistor which is manufactured by successively stacking a first polycrystalline silicon film into which phosphorous is doped at a low concentration, an interlayer insulating film, and a second polycrystalline silicon film into which phosphorous is doped at a high concentration.
Generally speaking, as a method for introducing an impurity such as phosphorous into the first and second polycrystalline silicon films constituting the floating gate and the control gate, there are an ion injection method in which accelerated impurity ions are injected into the polycrystalline silicon films and an vapor phase diffusion method or thermal diffusion method, in which oxyphosphorus chloride is vapored in a furnace, so that phosphorous is diffused from the vapor phase into the polycrystalline silicon films.
However, in the thermal diffusion method, since the impurity concentration is determined by the solid solution degree corresponding to the diffusion temperature, it is difficult to introduce the impurity at a low concentration into the polycrystalline silicon film. When the impurity concentration of the first polycrystalline silicon film of the memory cell transistor is increased, the boundary condition between the gate oxide film and the first polycrystalline silicon film is deteriorated, and the injection or extraction of electrons into or from the first polycrystalline silicon film of the floating gate can not be uniformly carried out, so that the memory cells fail to operate under stable condition.
On the other hand, in the ion injection method, it is difficult due to a breakage of the gate oxide film and/or occurrence of the crystal defects in the substrate to introduce the impurity into the first polycrystalline silicon film by an amount sufficient to lower its resistance. If the resistance of the first polycrystalline silicon film is not sufficiently lowered, then the resistance of the gate electrode made of the first and second polycrystalline silicon films of the peripheral transistor becomes higher. Then, if the resistance of the gate electrode becomes higher, the first polycrystalline silicon film is subjected to depletion state when the voltage is applied to the gate electrode, so that the threshold voltage of the peripheral transistor becomes unstable.
In a conventional nonvolatile semiconductor memory device in which both a memory cell transistor and another transistor other than the memory cell transistor have a two-layer polycrystalline silicon film gate structure, it is difficult to provide the polycrystalline silicon film of the under layer with an impurity concentration which satisfies the necessary condition of the memory cell transistor, as well as the condition required for the another transistor other than the memory cell transistor.
Further, the memory device of JP-A-59-74677 has a problem that since the first and second polycrystalline silicon films constituting the gate electrode disposed at an active region in the region for forming peripheral transistors are connected with each other through the opening formed at a predetermined position in the insulating film interposed therebetween, the impurities, if contained at a high concentration in the second polycrystalline silicon film, may be diffused into the first polycrystalline silicon film through the opening thereby deteriorating the boundary condition between the gate oxide film and the first polycrystalline silicon film.
SUMMARY OF THE INVENTION
An object of the present invention is to provide such a semiconductor device containing a first transistor having a composite gate structure, and a second transistor having a single gate structure. In this semiconductor device, each of the composite gate structure and the single gate structure is fabricated by a lamination of a first polycrystalline silicon film and a second polycrystalline silicon film. Also, an impurity concentration of the first polycrystalline silicon film for constructing the above-described composite gate structure, and an impurity concentration of the first polycrystalline silicon film for constituting the single gate structure can be controlled independently of each other.
According to one aspect of the present invention, a semiconductor device comprises: a first transistor having a composite gate structure containing a lamination of a first polycrystalline silicon film, an interlayer insulating film, and a second polycrystalline silicon film; and a second transistor having a single gate structure containing a lamination of a third polycrystalline silicon film and a fourth polycrystalline silicon film, wherein said first polycrystalline silicon film and said third polycrystalline silicon film have substantially the same thickness; said second polycrystalline silicon film and said fourth polycrystalline silicon film have substantially the same thickness; said first polycrystalline silicon film and said third polycrystalline silicon film have different impurity concentrations controlled independently of each other; and said second polycrystalline silicon film, said fourth polycrystalline silicon film, and said third polycrystalline silicon film have substantially the same impurity concentration.
In a preferred embodiment of the present invention, the impurity concentration of said first polycrystalline silicon film is 1×10 18 to 1×10 19 atoms/cm 3 , and the impurity concentration of said third polycrystalline silicon film is 1×10 20 to 1×10 21 atoms/cm 3 .
According to another aspect of the present invention, a semiconductor device comprises: a first transistor having a composite gate structure containing a lamination of a first conductive film, an insulating film, and a second conductive film; and a second transistor having a single gate structure containing a third conductive film; wherein said second conductive film and said third conductive film have substantially the same conductivity; said third conductive film has a thickness substantially the same as a total of a thickness of said first conductive film and a thickness of said second conductive film, or a total of a thickness of said first conductive film, a thickness of said insulating film, and a thickness of said second conductive film; and said first conductive film has a conductivity different from any one of a conductivity of said second conductive film and that of said third conductive film.
Furthermore, according to another aspect of the present invention, a semiconductor device comprises: a first transistor having a composite gate structure containing a lamination of a first conductive film, an insulating film formed on said first conductive film, and a second conductive film formed on said insulating film and having a conductivity different from that of said first conductive film; and a second transistor having a single gate structure containing a third conductive film having substantially the same conductivity as that of said second conductive film, and also having substantially the same thickness as a total of a film thickness of said first conductive film and a film thickness of said second conductive film, or a total of a thickness of said first conductive film, a thickness of said insulating film, and a thickness of said second conductive film.
According to one aspect of the present invention, a method for manufacturing a semiconductor device including a first transistor having a composite gate structure and a second transistor having a single gate structure, comprises the steps of: forming a first insulating film on a surface of a first region of a semiconductor substrate and forming a second insulating film on a surface of a second region of the semiconductor substrate; forming a first polycrystalline silicon film over an entire surface of said semiconductor substrate; introducing an impurity at a first predetermined concentration into said first polycrystalline silicon film by ion injection; patterning said first polycrystalline silicon film to a predetermined shape in said first region; forming a third insulating film containing at least a silicon nitride film on at least said first region except for said second region of said semiconductor substrate; forming a second polycrystalline silicon film over an entire surface of said semiconductor substrate; introducing an impurity at a second predetermined concentration higher than said first concentration into said second polycrystalline silicon film by thermal-diffusion; patterning a lamination of said second polycrystalline silicon film, said third insulating film, and said first polycrystalline silicon film into a predetermined pattern in said first region to thereby fabricate said composite gate structure of said first transistor; and patterning a lamination of said first polycrystalline silicon film and said second polycrystalline silicon film into a predetermined pattern in said second region to thereby fabricate said single gate structure of said second transistor.
Moreover, according to another aspect of the present invention, a method for manufacturing a semiconductor device including a first transistor having a composite gate structure and a second transistor having a single gate structure, comprises the steps of: forming a first insulating film on a surface of an active region disposed in a first region of a semiconductor substrate and a second insulating film on a surface of an active region disposed in a second region of the substrate; forming a first conductive film over an entire surface of said semiconductor substrate; introducing an impurity at a first predetermined concentration into said first conductive film by ion-injection; forming a third insulating film above said first conductive film at an area including at least said first region except for said second region, or an area including at least said first region and said active region of said second region except for an element isolation region of said second region; forming a conductive film over the entire surface of said semiconductor substrate; introducing an impurity at a predetermined second concentration higher than said first concentration into said second conductive film by thermal diffusion; patterning a lamination of said second conductive film, said third insulating film, and said first conductive film into a predetermined pattern to thereby fabricate said composite gate structure of said first transistor in the active region of said first region; and patterning a lamination of said first conductive film and said second conductive film into a predetermined pattern to thereby fabricate said single gate structure of said second transistor in the active region of said second region.
BRIEF DESCRIPTION OF THE DRAWINGS
FIGS. 1A to 1 H are sectional views at the respective steps of a method for manufacturing a semiconductor device according to an embodiment of the present invention;
FIGS. 2A and 2B are sectional views of gate electrode portions of a memory cell transistor and a peripheral transistor in the semiconductor device of the present invention;
FIGS. 3A and 3B are a sectional view and a plan view, of a peripheral transistor in a semiconductor device manufactured by a method according to a second embodiment of the present invention; and
FIG. 4 shows a section of a peripheral transistor according to a third embodiment of the present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring now to FIGS. 1A through 1H, method for manufacturing an EEPROM (Electrically Erasable Read-Only Memory), according to a first embodiment of the present invention, will be described. In each of FIG. 1A to FIG. 1H, the left-sided portion represents a memory cell transistor formed in the memory cell region, whereas the right-sided portion shows a MOS transistor (peripheral transistor) fabricated in the peripheral circuit region.
First, to manufacture the EEPROM according to the first embodiment, as illustrated in FIG. 1A, a field oxide film 2 having a thickness of an order of 500 nm is formed on a surface of a silicon substrate 1 by the LOCOS method to provide an element isolation region. Then, a tunnel oxide film 3 having a thickness of an order of 10 to 12 nm is fabricated on the silicon substrate 1 at a memory cell region in an active region surrounded by the element isolation region made of the field oxide film 2 by way of the thermal oxidation method. Thereafter, a gate oxide film 4 having a thickness of an order of 10 to 40 nm is formed on the silicon substrate 1 at a peripheral circuit region in the active region surrounded by the field oxide film 2 by the thermal oxidation method. It should be noted that the tunnel oxide film 3 and the gate oxide film 4 may be formed in a reversed order or at the same time.
Next, as illustrated in FIG. 1B, a polycrystalline silicon film 5 having a substantially uniform thickness of an order of 150 nm is formed over the entire surface by the CVD method.
Subsequently, as indicated in FIG. 1C, phosphorus is introduced by the ion injection method into the polycrystalline silicon film 5 at an impurity concentration of an order of 1×10 18 to 1×10 19 atoms/cm 3 . It is undesired that the impurity concentration in the polycrystalline silicon film 5 exceeds the above impurity concentration, because the boundary condition between the tunnel oxide film 3 and the polycrystalline silicon film 5 in the memory cell region is deteriorated, so that electrons are no more uniformly injected into or extracted from the polycrystalline silicon film 5 serving as the floating gate. It should be noted that instead of phosphorous, arsenic ions may be injected.
Next, as shown in FIG. 10, the polycrystalline silicon film 5 in the memory cell region is patterned to form a floating gate.
Thereafter, as indicated in FIG. 1E, an ONO film (silicon oxide film/silicon nitride film/silicon oxide film) 6 is formed over the entire surface by the CVD method. A thickness of each of the two silicon oxide film layers for constituting this ONO film 6 is in an order of 10 nm, a thickness of the silicon nitride film is in an order of 20 nm, and thus an overall thickness of the ONO film 6 , as converted to an equivalent thickness of the oxide film, is in an order of 30 nm.
Then, as shown in FIG. 1F, an etching treatment is carried out, while using a photoresist (not shown) of a pattern covering the memory cell region as a mask, so as to remove wholly a portion of the ONO film 6 formed on the peripheral circuit region.
Thereafter, as indicated in FIG. 1G, a polycrystalline silicon film 7 having a uniform thickness of approximately 150 nm is fabricated over the entire surface by the CVD method.
Next, as illustrated in FIG. 1H, phosphorous is diffused into the polycrystalline silicon film 7 by way of the vapor phase diffusion method by performing the thermal treatment in a furnace in which oxyphosphorus chloride (POCl 3 : phosphoryl trichloride) is vapored. This phosphorous vapor phase diffusion is carried out until the impurity concentration of the polycrystalline silicon film 7 becomes an order of 1×10 20 to 1×10 21 atom/cm 3 so that the impurity concentration of the polycrystalline silicon film 7 becomes at least 10 times that of the polycrystalline silicon film 5 . It should be understood that instead of phosphorous, arsenic may be diffused.
At this time, since the polycrystalline silicon film 5 is in contact with the polycrystalline silicon film 7 in the peripheral circuit region, phosphorous is also diffused from the polycrystalline silicon film 7 into the polycrystalline silicon film 5 , so that the impurity concentration of the polycrystalline silicon film 5 becomes approximately 1×10 20 to 1×10 21 atoms/cm 3 . On the other hand, the ONO film 6 containing the silicon nitride film which has a low diffusion speed of phosphorous is interposed between the polycrystalline silicon films 5 and in the memory cell region. As a result, phosphorous does not diffuse through the ONO film 6 into the polycrystalline silicon film 5 in the memory cell region. Accordingly, the impurity concentration of the polycrystalline silicon film 5 in the memory cell region remains at an order of 1×10 18 to 1×10 19 atoms/cm 3 .
Subsequently, after photoresist (not shown) has been coated over the entire surface, this photoresist is patterned to a shape of a control gate 15 of the memory cell transistor 11 (see FIG. 2A) in the memory cell region, and also a shape of a gate electrode 16 of a peripheral transistor 12 (see FIG. 2B) in the peripheral circuit region. Then, by using the patterned photoresist as a mask, an anisotropic etching is carried out with respect to the polycrystalline silicon film 7 , the ONO film 6 , and the polycrystalline silicon film 5 . As a result, a floating gate made of the polycrystalline silicon film 5 , and a control gate made of the polycrystalline silicon film 7 are fabricated in the memory cell region, whereas a gate electrode of the peripheral transistor, which is made of the polycrystalline silicon films 5 and 7 , is formed in the peripheral circuit region.
Thereafter, a step of forming impurity diffusion layers (not shown) serving as sources and drains of the memory cell transistor 11 and the peripheral transistor 12 , by ion-injection using the control gate and the gate electrode as a mask, and further a step of forming an interlayer insulating film (not shown) which covers the overall areas of the memory cell transistor 11 and the peripheral transistor 12 are carried out to thereby accomplish the EEPROM.
As described above, in accordance with this first embodiment, phosphorous is introduced into the polycrystalline silicon film 5 at a relatively low concentration by way of the ion injection method and the ONO film 6 is left at least on the polycrystalline silicon film 5 of the memory cell region. Therefore, when phosphorous is introduced at a relatively high concentration into the polycrystalline silicon film 7 by way of the vapor phase diffusion method, the silicon nitride film of the ONO film 6 functions as a diffusion stopper of phosphorous. As a consequence, the impurity concentration of the polycrystalline silicon film 5 of the memory cell region can be maintained at a relatively low level, and further the impurity concentration of the polycrystalline silicon film 5 of the peripheral circuit region can be set to the relatively high level.
In this embodiment, the polycrystalline silicon films 5 , 7 forming the gate electrode of the peripheral transistor, and the polycrystalline silicon film 7 forming the control gate of the memory transistor have substantially the same conductivity which is higher than the conductivity of the polycrystalline silicon film 5 forming the floating gate of the memory transistor. Also, since the polycrystalline silicon films 5 and 7 have essentially uniform sectional areas, each of the polycrystalline silicon films 5 , 7 forming the gate electrode of the peripheral transistor, and the polycrystalline silicon film 7 forming the control gate of the memory transistor have substantially the same resistance.
As a consequence, the boundary between the tunnel oxide film 3 of the memory cell transistor 11 and the polycrystalline silicon film 5 can be maintained at better condition, and furthermore, the resistance of the gate electrode of the peripheral transistor 12 can be made sufficiently low. As a result, it is possible to manufacture an EEPROM having high reliability and capable of operating at high speed.
It should also be noted that in this embodiment, the ONO film 6 formed in the peripheral circuit region is completely removed in the step of FIG. 1 F. Alternatively, the ONO film 6 fabricated in the peripheral circuit region may be partially removed so as to retain its portion disposed at a region where the peripheral transistor is formed. Also, in this case, since phosphorous which has been introduced by the vapor phase diffusion method is diffused into the polycrystalline silicon film 5 through a portion where the ONO film 6 was removed, the impurity concentration of the polycrystalline silicon film 5 of the peripheral circuit region can be set to a relatively high concentration. Moreover, in this case, since the film structure of the memory cell transistor 11 in the longitudinal direction is substantially identical to the film structure of the peripheral transistor 12 in the longitudinal direction, the workability can be advantageously improved in the step of forming the floating gate by applying anisotropic etching to the polycrystalline silicon film 7 , the ONO film 6 and the polycrystalline silicon film 5 .
Also, in this embodiment, the description has been made of a case where an MOS transistor which is formed at the same time with the memory cell transistor 11 is the MOS transistor 12 of the peripheral circuit region. Alternatively, this embodiment may be applied to such a case that, for instance, the selecting transistor selectively switching the memory cell transistor 11 in the EEPROM is fabricated at the same time with the memory cell transistor 11 . Moreover, this embodiment may be applied not only to manufacturing of the EEPROM, but also any nonvolatile semiconductor memory device such as an EPROM in which each of the memory cell transistor and other transistors than the memory cell transistor uses a two-layer polycrystalline silicon film structure.
Next, a second embodiment of the present invention will be explained with reference to FIGS. 3A and 3B. FIG. 3A shows a section of a portion including the gate electrode of a peripheral transistor in a step of the method of manufacturing a semiconductor device according to the second embodiment of the present invention, i.e. a section along the line IIIA to IIIA′ in FIG. 3B, which is a plan view of the region including the peripheral transistor in the second embodiment.
In the second embodiment, substantially the same steps as those in the first embodiment as shown in FIGS. 1A to 1 E are carried out. The second embodiment is different from the first embodiment in the step of FIG. 1 F. In the first embodiment, the ONO film disposed in the region where the peripheral transistor is formed has been removed in the step of FIG. 1 F. On the other hand, in the second embodiment, only a part of the ONO film disposed in the element-isolation region where the field oxide film 2 is formed is removed, while unremoving a part of the ONO film disposed in the region 23 as shown in FIG. 3B including the active region 21 where the peripheral transistor is formed by masking the region 23 . Therefore, in the second embodiment, a part of the ONO film disposed on the first polycrystalline silicon film of the peripheral transistor and at an area substantially above the active region is unremoved in the step corresponding to FIG. 1F of the first embodiment. As a result, in the step of FIG. 1H where the impurity ions are introduced into the polycrystalline silicon film 7 , the impurity ions are not introduced into a portion 5 a (FIG. 3B) of the polycrystalline silicon film 5 disposed on the active region so that the impurity concentration of the portion 5 a remains at a low level and its resistance remains at a high level. However, a portion 5 b of the polycrystalline silicon film 5 disposed over the field oxide film 5 and serving as a wiring of the gate electrode has substantially the same impurity concentration as that of the polycrystalline silicon film 7 , resulting in a low resistance of the portion 5 b , which is effective to prevent the delay in operation of its circuit. Further, due to the same reason as that in the case of the tunnel oxide.
Incidentally, in FIG. 3E, 19 indicates the source/drain region of a peripheral transistor, 24 or 25 indicates a contact hole for connecting the source/drain region to a wiring layer (not shown) and 22 indicates a contact hole for connecting the gate electrode of the peripheral transistor to a wiring layer (not shown).
As previously described, according to the present invention, since the impurity is introduced at a relatively low concentration into the first polycrystalline silicon film by ion-implantation and also the insulating film containing the silicon nitride film is left on the polycrystalline silicon film in the memory cell region, when phosphorous is introduced at a relatively high concentration into the second polycrystalline silicon film by way of the thermal diffusion method, the silicon nitride film functions as a stopper for diffusion of the impurity. As a consequence, the impurity concentration of the first polycrystalline silicon film of the memory cell region can be maintained at a relatively low level, and further the impurity concentration of the first polycrystalline silicon film of the peripheral transistor can be set to a relatively high level.
As a result, the boundary between the tunnel oxide film (first insulating film) of the memory cell transistor formed in the memory cell region and the first polycrystalline silicon film can be maintained at better condition, and furthermore, the resistance of the gate electrode wiring of the MOS transistor formed in the peripheral region can be made sufficiently low. As a result, it is possible to manufacture a nonvolatile semiconductor memory device having high reliability and capable of operating at high speed. | A semiconductor device comprises a first transistor having a composite gate structure containing a lamination of a first polycrystalline silicon film, an interlayer insulating film, and a second polycrystalline silicon film; and a second transistor having a single gate structure containing a lamination of a third polycrystalline silicon film and a fourth polycrystalline silicon film, wherein the first polycrystalline silicon film and the third polycrystalline silicon film have substantially the same thickness; the first polycrystalline silicon film and the third polycrystalline silicon film have different impurity concentrations controlled independently of each other; the second polycrystalline silicon film and the fourth polycrystalline silicon film have substantially the same thickness, and the second polycrystalline silicon film, the fourth polycrystalline silicon film, and the third polycrystalline silicon film have substantially the same impurity concentration. Also, a method for manufacturing the above-described semiconductor device is described. | 7 |
BACKGROUND OF THE INVENTION
This invention relates to 2-aminomethyl-5-hydroxy-4H-pyran-4-one and certain derivatives thereof, especially the amide derivatives, which are useful as skeletal muscle relaxants. The invention also relates to processes for the preparation of such compounds; to pharmaceutical compositions comprising such compounds; and to methods and treatment comprising administering such compounds and compositions when a muscle relaxant effect is indicated.
The 2-aminomethyl-5-hydroxy-4H-pyran-4-ones of the present invention may be represented generically by the following structural formula (I): ##SPC1##
wherein R is hydrogen, or R represents an acyl moiety derived from a carboxylic acid especially an α-amino acid.
Unexpectedly, it has been discovered that the above-described pyranones of the present invention are useful as skeletal muscle relaxants and can be used for treating muscle spasms and other similar muscle disorders associated with or caused by injury or arising spontaneously with no known cause. Muscle spasm, spasticity and related clinical disorders involving muscle hyperactivity or increased muscle tone affect a large section of the population. Such clinical disorders involving muscle hyperactivity include the spasticity of cerebral origin which may arise from brain injury or tumor. Another related disorder is cerebral palsy. Other clinical disorders involving tonic skeletal muscle hyperactivity are Parkinson's disease, muscular rigidity and muscle spasm of traumatic origin including low-back and cervical spine syndromes, many orthopedic deformities, arthritic states, myositis, whip-lash injuries, fractures, dislocation, cramps, sciatica, and spinal cord injuries. At present a variety of medicinals are used in an attempt to relieve or correct the clinical disorders involving muscle hyperactivity including muscle spasm and spasticity and pain associated therewith. But administration of these various materials unfortunately is attended by concomitant side effects and toxicity and/or lack of specificity which limit their usefulness. There is an unsatisfied need at the present time for a medication which has a high specific effect on the muscle hyperactivity associated with various clinical disorders when administered either by the oral or parenteral route which at the same time has a minimum of side effects or contraindications.
Accordingly it is an object of the present invention to provide the above-described pyranones which are useful as skeletal muscle relaxants. It is a further object of the present invention to provide pharmaceutical compositions comprising such pyranones and to provide methods of treatment comprising administering such compounds and compositions when a skeletal muscle relaxant effect is indicated.
DETAILED DESCRIPTION OF THE INVENTION
In general, 2-aminomethyl-5-hydroxy-4H-pyran-4-ones of the present invention may conveniently be prepared from kojic acid [5-hydroxy-2-hydroxymethyl-4H-pyran-4-one], which is readily available. Blocking of the 5-hydroxy group as an ether derivative is necessary in some reactions and this can be carried out readily by reacting kojic acid with and alkyl or aralkyl halide such as benzyl halide (bromide or chloride) or the like in the presence of a strong base such as sodium methoxide and the like to form an alkyl ether which functions as a readily removable blocking group. This first step, protection of the 5-hydroxy group, is preferred in the preparation of the instant amide derivatives but is not necessary for the preparation of N-unsubstituted 2-aminomethyl-5-hydroxy-4H-pyran-4-one. There is no criticality as to the reaction temperature or solvent in this first step; for example, the conditions of A. F. Thomas and A. Marxer, 43 Helv. Chim. Acta 469 (1960) have been found to be suitable for the preparation of such ether derivatives. In the second step, the 5-protected intermediate (or kojic acid) is converted to its tosylate (or other alkyl or aryl sulfonate) by reaction with tosyl chloride in the presence of a base such as pyridine. Such sulfonation reactions are well-known and there is no criticality to the instant procedure; for example, the procedure of A. F. Thomas, J. Chem. Soc. 439 (1962) has been found suitable. Conversion of the sulfonate ester thus formed to the amino group may be accomplished directly by reaction with ammonia, or indirectly, for example via the production of an azide by reaction of the sulfonate with sodium azide in a solvent such as dimethylformamide. The azide species thus formed is easily reduced to the amine by treatment with a reducing agent such as, for example, hydrobromic acid in acetic acid in the presence of a bromine trapping reagent such as acetone or phenol, or alternatively catalytic hydrogenolysis. The 5-blocking group is easily removed by acid hydrolysis and, in the hydrobromic acid/acetic acid procedure, is removed simultaneously with the reduction of the azide. In a more direct route to 2-aminomethyl-5-hydroxy-4H-pyran-4-one, 5-hydroxy-4H-pyran-4-on-2-ylmethyl chloride or its sulfonate ester can be converted to the azide which is then reduced to the desired amine, without involvement of the 5-protected intermediate. The following schematic diagram illustrates the above generally described process. ##SPC2##
In addition to the free amine, 2-aminomethyl-5-hydroxy-4H-pyran-4-one (I), preferred embodiments of the present invention comprise amide derivatives of I. The most preferred amide derivatives are those formed from α-amino acids such as glycine and alanine, that is 2-amino-N-[(5-hydroxy-4H-pyran-4-on-2-yl)methyl] acetamide and 2-amino-N-[(5-hydroxy-4H-pyran-4-on-2-yl)methyl] propionamide, respectively. Such amides are formed by reaction of 2-aminomethyl-5-aralkyloxy-4H-pyran-4-one with suitable amine blocked amino acid intermediates by procedures well-known in peptide chemistry followed by removal of blocking groups. Thus for example, treating 2-aminomethyl-5-benzyloxy-4H-pyran-4 -one with N-benzyloxycarbonylglycine p-nitrophenyl ester in isopropanol at reflux provides 2-benzyloxycarbonylamino-N-[(5-benzyloxy-4H-pyran-4-one-2-yl)methyl]acetamide which is readily hydrolyzed with hydrobromic acid in acetic acid to 2-amino-N-[(5-hydroxy-4H-pyran-4-on-2-yl)methyl]acetamide.
Also contemplated within the scope of the present invention are pharmaceutically acceptable salt, ester and amide derivatives of the pyranones of the present invention represented by structural formula I. Such pharmaceutically acceptable forms may be prepared by conventional means. Salt forms are the most preferred and include (relative to the amino nitrogen): the hydrochloride, hydrobromide, sulfate, phosphate, citrate, tartrate, succinate and the like; with respect to salts based upon acidic hydroxyl function, salts derived from the alkali and alkaline earth metals such as sodium and potassium are preferred. These pharmaceutically acceptable salt, ester and amide derivatives of I are generally equivalent in potency to the free amino form of I or the preferred amides thereof taking into consideration the stoichiometric quantities employed.
In the method of treatment and pharmaceutical composition aspects of the present invention it is to be noted that the precise unit dosage form and dosage level depend upon the case history of the individual being treated and consequently are left to the discretion of the therapist. In general, however, the compounds of the present invention produce the desired effect of skeletal muscle relaxation when given at from about 0.1 to about 30 mg/kg. body weight per day. Any of the usual pharmaceutical forms may be employed such as tablets, elexirs and aqueous suspensions comprising from about 0.1 to about 30.0 mg. of the compounds of this invention per kilogram body weight given daily. Thus for example tablets given 2-4 times per day comprising from about 0.5 to about 75.0 mg. of the compounds of this invention are suitable; however, the preferred range for the unit dosage level in the form of tablets is from about 2.0 to about 40.0 mg. of the compounds of the present invention. Sterile solutions for injection comprising from about 1 to about 30.0 mg. per dose of the compounds of this invention given 2-4 times daily are also a suitable means of delivery.
The following examples representatively illustrate but do not limit the product, compositional or method of treatment aspects of the present invention.
EXAMPLE 1
Preparation of 2-aminomethyl-5-hydroxy-4H-pyran-4-one
A mixture of 143 g. of 2-azidomethyl-5-hydroxy-4H-pyran-4-one, prepared according to the procedure reported in 9 J. Chem. and Eng. Data 228 (1964), and 72 g. phenol is dissolved in 700 ml. of acetic acid. The solution is cooled in an ice bath and saturated with HBr gas. After half an hour a precipitate appears which is stirred for three hours. The mixture is cooled with ice and filtered. The solid is washed first with acetic acid, then freely with tetrahydrofuran, and finally with ether. After drying, there is obtained 287 g. of the dihydrobromide of 2-aminomethyl-5-hydroxy-4H-pyran-4-one, m.p. 206°-207°C.
The resulting dihydrobromide (287 g.) is dissolved in 1.5 liters of methanol and 1 liter of tetrahydrofuran is added. The solution is concentrated to a low volume (500 cc.) by evaporation in vacuum and 1 liter of tetrahydrofuran added. The solid is filtered, yielding 154 g. of the monohydrobromide of 2-aminomethyl-5-hydroxy-4H-pyran-4-one, m.p. 220°-222°C.
Analysis calcd.: C, 32.43; H, 3.60; N, 6.36; Br, 36.03.
Analysis found: C, 32.40; H, 3.76; N, 6.58; Br, 36.01.
EXAMPLE 2
Preparation of 2-amino-N-[(5-hydroxy-4H-pyran-4-on-2-yl)-methyl] acetamide
A mixture of 5 grams of 2-aminomethyl-5-benzyloxy-4H-pyran-4-one and 7.5 grams of the commercially available N-benzyloxycarbonylglycine p-nitrophenyl ester in 120 ml. isopropanol is refluxed for 20 minutes. At the beginning the solution becomes clear and then the end product crystallizes out. The solid is filtered while hot, yielding 7 grams, m.p. 179°-180°, of the intermediate 2-benzyloxycarbonylamino-N-[(5-benzyloxy-4H-pyran-4-on-2-yl)methyl]acetamide.
The resulting intermediate (5 g.) is dissolved in 70 ml. acetic acid and the resulting solution is saturated with HBr and refluxed for 30 minutes. The material dissolves at first and the desired product (4 g.) precipitates in the form of the dihydrobromide. The dihydrobromide is recrystallized from methanol yielding 2.08 grams of the monohydrobromide of 2-amino-N-[(5-hydroxy-4H-pyran-4-on-2-yl)-methyl]acetamide, m.p. 216°-218°C.
Analysis calcd.: C, 34.40; H, 3.99; N, 10.00; Br, 28.65.
Analysis found: C, 34.68; H, 4.02; N, 10.40; Br, 29.08.
EXAMPLE 3
Preparation of 2-amino-N-[(5-hydroxy-4H-pyran-4-on-2-yl)-methyl]propionamide
To a mixture of 5.04 g N-benzyloxycarbonyl-α-alanine, prepared by known methods [Ber. 65B, 1192-1201 (1932)], 60 ml methylene chloride and 4.5 ml triethylamine cooled at -5°C, is added 2.8 ml ethylchloroformate. The mixture is stirred for 5 minutes. To the resulting solution is added a mixture of 6.56 g 2-aminomethyl-5-benzyloxy-4H-pyran-4-one, 12 ml triethylamine and 60 ml methylene chloride. The mixture is stirred for 15 minutes at -5°C and 3 hours at 25°C, then extracted with dilute HCl, bicarbonate solution and then water. The organic layer is dried over Na 2 SO 4 and evaporated to dryness. The residue is treated with ether and filtered to yield 7.75 g of the intermediate, 2-benzyloxycarbonylamino-N-[(5-benzyloxy-4H-pyran-4-on-2-yl)methyl]propionamide.
The resulting intermediate (7.7 g) is dissolved in 120 ml acetic acid; the solution is saturated with HBr and heated at 90°C for 25 minutes, evaporated to dryness, and then 50 ml acetic acid is added and again evaporated to dryness. The residue is triturated with ether and decanted. The residue is dissolved in the minimum amount of water at 25°C, extracted with ether, and the aqueous phase evaporated to dryness yielding 7.4 g of a semisolid which is passed through a DOWEX 50W-X8 resin (supplied by BIO-RAD Laboratories) by elution with 1N NH 4 OH. The eluate is evaporated to dryness, dried at 85°C in high vacuum for 8 hours to yield 2.97 g of pure 2-amino-N-[(5-hydroxy-4H-pyran-4-on-2-yl)methyl]propionamide, m.p. 175°-178°C (dec.).
EXAMPLE 4
Pharmaceutical compositions
A typical tablet containing 5 mg. 2-aminomethyl-5-hydroxy-4H-pyran-4-one per tablet is prepared by mixing together with the active ingredient calcium phosphate, lactose and starch in the amounts shown in the tables below. After these ingredients are thoroughly mixed, the appropriate amount of magnesium stearate is added and the dry mixture blended for an additional three minutes. This mixture is then compressed into tablets weighing approximately 129 mg. each. Similarly prepared are tablets containing 2-amino-N-[(5-hydroxy-4H-pyran-4-on-2-yl)methyl]acetamide, and 2-amino-N[(5-hydroxy-4H-pyran-4-on-2-yl)methyl]propionamide, respectively.
______________________________________TABLET FORMULAINGREDIENT MG. PER TABLET______________________________________2-Aminomethyl-5-hydroxy-4H-pyran-4-one 5 mg.Calcium phosphate 52 mg.Lactose 60 mg.Starch 10 mg.Magnesium stearate 1 mg.TABLET FORMULAINGREDIENT MG. PER TABLET2-Amino-N-[(5-hydroxy-4H-pyran-4-on-2-yl)methyl]acetamide 5 mg.Calcium phosphate 52 mg.Lactose 60 mg.Starch 10 mg.Magnesium stearate 1 mg.TABLET FORMULAINGREDIENT MG. PER TABLET2-Amino-N[(5-hydroxy-4H-pyran-4-on-2-yl)methyl]propionamide 5 mg.Calcium phosphate 52 mg.Lactose 60 mg.Starch 10 mg.Magnesium stearate 1 mg.______________________________________ | The 2-aminomethyl-5-hydroxy-4H-pyran-4-ones of the present invention are disclosed to have pharmaceutical utility as skeletal muscle relaxants. Also disclosed are processes for the preparation of such pyranones; pharmaceutical compositions comprising such compounds; and method of treatment comprising administering such compounds and compositions when a muscle relaxant effect is indicated. | 2 |
TECHNICAL FIELD
[0001] This disclosure is directed to a new crystalline molecular sieve designated SSZ-102 having ESV framework topology, a method for preparing SSZ-102 using an N,N′-dimethyl-1,4-diazabicyclo[2.2.2]octane dication as a structure directing agent and uses for SSZ-102.
BACKGROUND
[0002] Molecular sieves are a commercially important class of crystalline materials. They have distinct crystal structures with ordered pore structures which are demonstrated by distinct X-ray diffraction patterns. The crystal structure defines cavities and pores which are characteristic of the different species.
[0003] Molecular sieves are classified by the Structure Commission of the International Zeolite Association according to the rules of the IUPAC Commission on Zeolite Nomenclature. According to this classification, framework type zeolites and other crystalline microporous molecular sieves, for which a structure has been established, are assigned a three letter code and are described in the “ Atlas of Zeolite Framework Types ,” Sixth Revised Edition, Elsevier, 2007.
[0004] ERS-7 is a single crystalline phase zeolite having a structure consisting of 17-sided (4 6 5 4 6 5 8 2 ) “picnic basket”-shaped cages connected by 8-membered ring windows with 4.7×3.5 Å free dimensions. The framework structure of ERS-7 has been assigned the three-letter code ESV by the Structure Commission of the International Zeolite Association.
[0005] Italian Patent No. 1270630 discloses zeolite ERS-7 and its synthesis using an N,N-dimethylpiperidinium cation as a structure directing agent. ERS-7 is reported to have a SiO 2 /Al 2 O 3 mole ratio between 15 and 30.
[0006] It has now been found that crystalline molecular sieves having ESV framework topology and having a SiO 2 /Al 2 O 3 mole ratio of from 5 to 12 can be prepared using an N,N′-dimethyl-1,4-diazabicyclo[2.2.2]octane cation as a structure directing agent.
SUMMARY
[0007] This disclosure is directed to a family of crystalline molecular sieves with unique properties, referred to herein as “molecular sieve SSZ-102” or simply “SSZ-102”. SSZ-102 has the framework topology designated “ESV” by the International Zeolite Association.
[0008] In one aspect, there is provided a crystalline molecular sieve having ESV framework topology and having a SiO 2 /Al 2 O 3 mole ratio of from 5 to 12. Molecular sieve SSZ-102 has, in its calcined form, the X-ray diffraction lines of Table 4.
[0009] In another aspect, there is provided a method for preparing a crystalline molecular sieve having ESV framework topology by contacting under crystallization conditions: (1) at least one source of silicon; (2) at least one source of aluminum; (3) at least one source of an element selected from Groups 1 and 2 of the Periodic Table; (4) hydroxide ions; and (5) an N,N′-dimethyl-1,4-diazabicyclo[2.2.2]octane dication as a structure directing agent.
[0010] In yet another aspect, there is provided a process for preparing a molecular sieve having ESV framework topology by: (a) preparing a reaction mixture containing: (1) at least one source of silicon; (2) at least one source of aluminum; (3) at least one source of an element selected from Groups 1 and 2 of the Periodic Table; (4) hydroxide ions; (5) an N,N′-dimethyl-1,4-diazabicyclo[2.2.2]octane dication; and (6) water; and (b) subjecting the reaction mixture to crystallization conditions sufficient to form crystals of the molecular sieve.
[0011] In still yet another aspect, there is provided a crystalline molecular sieve having ESV framework topology and having a composition, as-synthesized and in its anhydrous state, in terms of mole ratios, as follows:
[0000] Broad Exemplary SiO 2 /Al 2 O 3 5 to 12 5 to 10 Q/SiO 2 0.015 to 0.15 0.04 to 0.10 M/SiO 2 0.010 to 0.20 0.05 to 0.20
wherein Q is an N,N′-dimethyl-1,4-diazabicyclo[2.2.2]octane dication and M is selected from the group consisting of elements from Groups 1 and 2 of the Periodic Table.
BRIEF DESCRIPTION OF THE DRAWINGS
[0012] FIG. 1 is a powder X-ray diffraction (XRD) pattern of the as-synthesized molecular sieve prepared in Example 1.
[0013] FIG. 2 is a Scanning Electron Micrograph (SEM) image of the as-synthesized molecular sieve prepared in Example 1.
[0014] FIG. 3 shows a comparison of two X-ray diffraction patterns, the top one being calcined SSZ-102 as prepared in Example 10 and the bottom one being as-synthesized SSZ-102 as prepared in Example 1.
DETAILED DESCRIPTION
[0015] Reaction Mixture
[0016] In preparing SSZ-102, an N,N′-dimethyl-1,4-diazabicyclo[2.2.2]octane dication (“dimethyl DABCO dication”) is used as a structure directing agent (“SDA”), also known as a crystallization template. The SDA useful for making the molecular sieve is represented by the following structure (1):
[0000]
[0017] SDA dication is typically associated with anions which can be any anion which is not detrimental to the formation of the molecular sieve. Representative anions include elements from Group 17 of the Periodic Table (e.g., fluoride, chloride, bromide and iodide), hydroxide, sulfate, tetrafluoroborate, acetate, carboxylate, and the like. As used herein, the numbering scheme for the Periodic Table Groups is as described in Chem. Eng. News 63(5), 26-27 (1985).
[0018] In general, molecular sieve SSZ-102 is prepared by: (a) preparing a reaction mixture containing (1) at least one source of silicon; (2) at least one source of aluminum; (3) at least one source of an element selected from Groups 1 and 2 of the Periodic Table; (4) hydroxide ions; (5) an N,N′-dimethyl-1,4-diazabicyclo[2.2.2]octane dication; and (6) water; and (b) subjecting the reaction mixture to crystallization conditions sufficient to form crystals of the molecular sieve.
[0019] The composition of the reaction mixture from which the molecular sieve is formed, in terms of mole ratios, is identified in Table 1 below:
[0000] TABLE 1 Reactants Broad Exemplary SiO 2 /Al 2 O 3 5 to 50 10 to 30 M/SiO 2 0.10 to 1.00 0.40 to 0.90 Q/SiO 2 0.05 to 0.50 0.15 to 0.35 OH/SiO 2 0.10 to 1.20 0.70 to 1.20 H 2 O/SiO 2 10 to 70 15 to 35
wherein compositional variables M and Q are as described herein above.
[0020] Sources useful herein for silicon include fumed silica, precipitated silicates, silica hydrogel, silicic acid, colloidal silica, tetra-alkyl orthosilicates (e.g., tetraethyl orthosilicate), and silica hydroxides.
[0021] Sources useful for aluminum include oxides, hydroxides, acetates, oxalates, ammonium salts and sulfates of aluminum. Typical sources of aluminum oxide include aluminates, alumina, and aluminum compounds such as AlCl 3 , Al 2 (SO 4 ) 3 , Al(OH) 3 , kaolin clays, and other zeolites. An example of the source of aluminum oxide is zeolite Y.
[0022] For each embodiment described herein, the molecular sieve reaction mixture can be supplied by more than one source. Also, two or more reaction components can be provided by one source.
[0023] The reaction mixture can be prepared either batch wise or continuously. Crystal size, morphology and crystallization time of the molecular sieve described herein can vary with the nature of the reaction mixture and the synthesis conditions.
[0024] Crystallization and Post-Synthesis Treatment
[0025] In practice, molecular sieve SSZ-102 is prepared by: (a) preparing a reaction mixture as described herein above; and (b) subjecting the reaction mixture to crystallization conditions sufficient to form crystals of the molecular sieve.
[0026] The reaction mixture is maintained at an elevated temperature until the molecular sieve is formed. The hydrothermal crystallization is usually conducted under pressure and usually in an autoclave so that the reaction mixture is subject to autogenous pressure, at a temperature of from 125° C. to 200° C.
[0027] The reaction mixture can be subjected to mild stirring or agitation during the crystallization step. It will be understood by the skilled artisan that the molecular sieves described herein can contain impurities, such as amorphous materials, unit cells having framework topologies which do not coincide with the molecular sieve, and/or other impurities.
[0028] During the hydrothermal crystallization step, the molecular sieve crystals can be allowed to nucleate spontaneously from the reaction mixture. The use of crystals of the molecular sieve as seed material can be advantageous in decreasing the time necessary for complete crystallization to occur. In addition, seeding can lead to an increased purity of the product obtained by promoting nucleation and/or formation of the molecular sieve over any undesired phases. When used as seeds, seed crystals are added in an amount of from 1 to 10 wt. % of the source of silicon used for the reaction mixture.
[0029] Once the molecular sieve has formed, the solid product is separated from the reaction mixture by standard mechanical techniques such as filtration. The crystals are water-washed and then dried to obtain the as-synthesized molecular sieve crystals. The drying step can be performed at atmospheric pressure or under vacuum.
[0030] The molecular sieve can be used as-synthesized, but typically will be thermally treated (calcined). The term “as-synthesized” refers to the molecular sieve in its form after crystallization, prior to removal of the SDA cation. The SDA cation can be removed by thermal treatment (e.g., calcination), preferably in an oxidative atmosphere (e.g., air, gas with an oxygen partial pressure of greater than 0 kPa) at a temperature readily determinable by the skilled artisan sufficient to remove the SDA from the molecular sieve. The SDA can also be removed by photolysis techniques (e.g., exposing the SDA-containing molecular sieve product to light or electromagnetic radiation that has a wavelength shorter than visible light under conditions sufficient to selectively remove the organic matter from the molecular sieve) as described in U.S. Pat. No. 6,960,327.
[0031] The molecular sieve can subsequently be calcined in steam, air or inert gas at temperatures ranging from 200° C. to 800° C. for periods of time ranging from 1 to 48 hours, or more. Usually, it is desirable to remove the extra-framework cation (e.g., Na + ) by ion exchange or other known method and replace it with hydrogen, ammonium, or any desired metal ion.
[0032] Where the molecular sieve formed is an intermediate material, the target molecular sieve can be achieved using post-synthesis techniques to allow for the synthesis of a target material having a higher Si/Al ratio from an intermediate material by acid leaching or other similar dealumination methods.
[0033] The molecular sieve made by the process described herein can be formed into a wide variety of physical shapes. Generally speaking, the molecular sieve can be in the form of a powder, a granule, or a molded product, such as extrudate having a particle size sufficient to pass through a 2-mesh (Tyler) screen and be retained on a 400-mesh (Tyler) screen. In cases where the catalyst is molded, such as by extrusion with an organic binder, the molecular sieve can be extruded before drying or dried or partially dried and then extruded.
[0034] The molecular sieve can be composited with other materials resistant to the temperatures and other conditions employed organic conversion processes. Such matrix materials include active and inactive materials and synthetic or naturally occurring zeolites as well as inorganic materials such as clays, silica and metal oxides. Examples of such materials and the manner in which they can be used are disclosed in U.S. Pat. Nos. 4,910,006 and 5,316,753.
[0035] Characterization of the Molecular Sieve
[0036] Molecular sieves synthesized by the process described herein have a composition, as-synthesized and in its anhydrous state, as described in Table 2 (in terms of mole ratios):
[0000] TABLE 2 Broad Exemplary SiO 2 /Al 2 O 3 5 to 12 5 to 10 Q/SiO 2 0.015 to 0.15 0.04 to 0.10 M/SiO 2 0.010 to 0.20 0.05 to 0.20
wherein compositional variables Q and M are as described herein above.
[0037] Molecular sieves made by the process disclosed herein are characterized by their XRD pattern. The powder XRD pattern lines of Table 3 are representative of as-synthesized SSZ-102 made in accordance with this disclosure. Minor variations in the powder XRD pattern can result from variations in the mole ratios of the framework species of the particular sample due to changes in lattice constants. In addition, sufficiently small crystals will affect the shape and intensity of peaks, leading to significant peak broadening. Minor variations in the powder XRD pattern can also result from variations in the organic compound used in the preparation of the molecular sieve. Calcination can also cause minor shifts in the powder XRD pattern. Notwithstanding these minor pertubations, the basic crystal lattice structure remains unchanged.
[0000]
TABLE 3
Characteristic Peaks for As-Synthesized SSZ-102
2-Theta (a)
d-Spacing, nm
Relative Intensity (b)
7.53
1.173
W
7.93
1.115
W
9.64
0.916
W
11.91
0.743
W
13.38
0.661
M
13.64
0.649
M
14.06
0.630
M
14.46
0.612
W
15.27
0.580
W
15.82
0.560
W
16.00
0.554
M
17.08
0.519
M
17.87
0.496
W
18.30
0.484
W
19.04
0.466
VS
19.16
0.463
M
19.56
0.453
S
20.36
0.436
W
20.75
0.428
W
21.09
0.421
M
21.25
0.418
M
(a) ±0.20 degrees
(b) The powder XRD patterns provided are based on a relative intensity scale in which the strongest line in the X-ray diffraction pattern is assigned a value of 100: W = weak (>0 to ≦20); M = medium (>20 to ≦40); S = strong (>40 to ≦60); VS = very strong (>60 to ≦100).
[0038] The X-ray diffraction lines of Table 4 are representative of calcined SSZ-102 made in accordance with this disclosure.
[0000]
TABLE 4
Characteristic Peaks for Calcined SSZ-102
2-Theta (a)
d-Spacing, nm
Relative Intensity (b)
7.60
1.162
W
8.01
1.103
M
9.74
0.908
M
12.02
0.736
M
13.44
0.658
VS
13.70
0.646
VS
14.11
0.627
VS
14.56
0.608
W
15.30
0.579
W
15.87
0.558
W
16.20
0.547
W
17.16
0.516
W
17.96
0.493
W
18.38
0.482
W
19.12
0.464
VS
19.31
0.459
VS
19.70
0.450
S
20.39
0.435
W
20.89
0.425
W
21.16
0.419
M
21.34
0.416
M
(a) ±0.20 degrees
(b) The powder XRD patterns provided are based on a relative intensity scale in which the strongest line in the X-ray diffraction pattern is assigned a value of 100: W = weak (>0 to ≦20); M = medium (>20 to ≦40); S = strong (>40 to ≦60); VS = very strong (>60 to ≦100).
[0039] The powder XRD patterns presented herein were collected by standard techniques. The radiation was CuK α , radiation. The peak heights and the positions, as a function of 20 where 20 is the Bragg angle, were read from the relative intensities of the peaks, and d, the interplanar spacing corresponding to the recorded lines, can be calculated.
[0040] Processes Using SSZ-102
[0041] SSZ-102 is useful as an adsorbent for gas separations. SSZ-102 can also be used as a catalyst for converting oxygenates (e.g., methanol) to olefins and for making small amines. SSZ-102 can be used to reduce oxides of nitrogen in a gas streams, such as automobile exhaust. SSZ-102 can also be used to as a cold start hydrocarbon trap in combustion engine pollution control systems. SSZ-102 is particularly useful for trapping C 3 fragments.
EXAMPLES
[0042] The following illustrative examples are intended to be non-limiting.
Example 1
[0043] 0.45 g of a 50% NaOH solution, 2.28 g of deionized water, and 0.50 g of CBV720 Y-zeolite powder (Zeolyst International, SiO 2 /Al 2 O 3 mole ratio=30) were mixed together in a Teflon liner. Then, 1.08 g of a 19% dimethyl DABCO hydroxide solution was added to the mixture. The Teflon liner was then capped and placed within a steel Parr autoclave. The autoclave was placed on a spit within a convection oven and heated at 135° C. for 4 days. The autoclave was removed and allowed to cool to room temperature. The solids were then recovered by filtration, washed thoroughly with deionized water and dried at 95° C.
[0044] The resulting molecular sieve product was analyzed by powder XRD and SEM. The resulting powder XRD pattern is shown in FIG. 1 and indicates that the product is a pure ESV framework type molecular sieve. FIG. 2 is a SEM image of the product and shows a uniform field of crystals.
[0045] The product had a SiO 2 /Al 2 O 3 mole ratio of 7.67, as determined by ICP elemental analysis.
Example 2
[0046] 0.87 g of a 50% NaOH solution, 6.87 g of deionized water, and 1.00 g of CBV720 Y-zeolite powder (Zeolyst International, SiO 2 /Al 2 O 3 mole ratio=30) were mixed together in a Teflon liner. Then, 2.18 g of a 19% dimethyl DABCO hydroxide solution was added to the mixture. The Teflon liner was then capped and placed within a steel Parr autoclave. The autoclave was placed on a spit within a convection oven and heated at 150° C. for 4 days. The autoclave was removed and allowed to cool to room temperature. The solids were then recovered by filtration, washed thoroughly with deionized water and dried at 95° C.
[0047] The product of this preparation was identified by powder XRD analysis as a pure ESV framework type molecular sieve.
[0048] The product had a SiO 2 /Al 2 O 3 mole ratio of 8.74, as determined by ICP elemental analysis.
Example 3
[0049] 0.50 g of a 50% NaOH solution, 4.50 g of deionized water, and 0.50 g of CBV720 Y-zeolite powder (Zeolyst International, SiO 2 /Al 2 O 3 mole ratio=30) were mixed together in a Teflon liner. Then, 1.10 g of a 19% dimethyl DABCO hydroxide solution was added to the mixture. The Teflon liner was then capped and placed within a steel Parr autoclave. The autoclave was placed on a spit within a convection oven and heated at 135° C. for 4 days. The autoclave was removed and allowed to cool to room temperature. The solids were then recovered by filtration, washed thoroughly with deionized water and dried at 95° C.
[0050] The product of this preparation was identified by powder XRD analysis as a pure ESV framework type molecular sieve.
[0051] The product had a SiO 2 /Al 2 O 3 mole ratio of 8.21, as determined by ICP elemental analysis.
Example 4
[0052] 0.40 g of a 50% NaOH solution, 1.05 g of deionized water, and 0.51 g of CBV720 Y-zeolite powder (Zeolyst International, SiO 2 /Al 2 O 3 mole ratio=30) were mixed together in a Teflon liner. Then, 1.09 g of a 19% dimethyl DABCO hydroxide solution was added to the mixture. The Teflon liner was then capped and placed within a steel Parr autoclave. The autoclave was placed on a spit within a convection oven and heated at 135° C. for 4 days. The autoclave was removed and allowed to cool to room temperature. The solids were then recovered by filtration, washed thoroughly with deionized water and dried at 95° C.
[0053] The product of this preparation was identified by powder XRD analysis as a pure ESV framework type molecular sieve.
[0054] The product had a SiO 2 /Al 2 O 3 mole ratio of 8.03, as determined by ICP elemental analysis.
Example 5
[0055] 0.51 g of a 50% NaOH solution, 2.25 g of deionized water, and 0.50 g of CBV720 Y-zeolite powder (Zeolyst International, SiO 2 /Al 2 O 3 mole ratio=30) were mixed together in a Teflon liner. Then, 1.09 g of a 19% dimethyl DABCO hydroxide solution was added to the mixture. The Teflon liner was then capped and placed within a steel Parr autoclave. The autoclave was placed on a spit within a convection oven and heated at 135° C. for 4 days. The autoclave was removed and allowed to cool to room temperature. The solids were then recovered by filtration, washed thoroughly with deionized water and dried at 95° C.
[0056] The product of this preparation was identified by powder XRD analysis as a mixture of ESV framework type molecular sieve and a small portion of ANA framework type molecular sieve.
Example 6
[0057] 1.90 g of a 50% NaOH solution, 5.14 g of deionized water, and 5.00 g of LZ-210 Y-zeolite powder (SiO 2 /Al 2 O 3 mole ratio=13) were mixed together in a Teflon liner. Then, 14.89 g of a 19% dimethyl DABCO hydroxide solution was added to the mixture. Finally, 6.11 g of a 38.5% sodium silicate solution was added to the mixture and the gel was stirred until it became homogeneous. The Teflon liner was then capped and placed within a steel Parr autoclave. The autoclave was placed on a spit within a convection oven and heated at 150° C. for 6 days. The autoclave was removed and allowed to cool to room temperature. The solids were then recovered by filtration, washed thoroughly with deionized water and dried at 95° C.
[0058] The product of this preparation was identified by powder XRD analysis as a mixture of ESV framework type molecular sieve and ANA framework type molecular sieve.
Example 7
[0059] 0.38 g of a 50% NaOH solution, 2.02 g of deionized water, and 0.51 g of CBV720 Y-zeolite powder (Zeolyst International, SiO 2 /Al 2 O 3 mole ratio=30) were mixed together in a Teflon liner. Then, 1.45 g of a 19% dimethyl DABCO hydroxide solution was added to the mixture. The Teflon liner was then capped and placed within a steel Parr autoclave. The autoclave was placed on a spit within a convection oven and heated at 135° C. for 4 days. The autoclave was removed and allowed to cool to room temperature. The solids were then recovered by filtration, washed thoroughly with deionized water and dried at 95° C.
[0060] The product of this preparation was identified by powder XRD analysis as a mixture of ESV framework type molecular sieve and a small portion of LEV framework type molecular sieve.
Example 8
[0061] 2.39 g of a 50% NaOH solution, 6.78 g of deionized water, and 4.00 g of LZ-210 Y-zeolite powder (SiO 2 /Al 2 O 3 mole ratio=13) were mixed together in a Teflon liner. Then, 11.17 g of a 19% dimethyl DABCO hydroxide solution was added to the mixture. Finally, 8.37 g of a 38.5% sodium silicate solution was added to the mixture and the gel was stirred until it became homogeneous. The Teflon liner was then capped and placed within a steel Parr autoclave. The autoclave was placed on a spit within a convection oven and heated at 150° C. for 7 days. The autoclave was removed and allowed to cool to room temperature. The solids were then recovered by filtration, washed thoroughly with deionized water and dried at 95° C.
[0062] The product of this preparation was identified by powder XRD analysis as a mixture of ESV framework type molecular sieve and LEV framework type molecular sieve.
Example 9
[0063] 1.45 g of a 50% NaOH solution, 2.46 g of deionized water, and 0.49 g of a 50% aluminum hydroxide solution (Barcroft™ USP 0250) were mixed together in a Teflon liner. Then, 5.55 g of a 19% dimethyl DABCO hydroxide solution was added to the mixture. Finally, 6.00 g of colloidal silica (LUDOX® AS-40) was added to the mixture and the gel was stirred until it became homogeneous. The Teflon liner was then capped and placed within a steel Parr autoclave. The autoclave was placed on a spit within a convection oven and heated at 170° C. for 7 days. The autoclave was removed and allowed to cool to room temperature. The solids were then recovered by filtration, washed thoroughly with deionized water and dried at 95° C.
[0064] The product of this preparation was identified by powder XRD analysis as a mixture of ESV framework type molecular sieve, ANA framework type molecular sieve and MOR framework type molecular sieve.
Example 10
Calcination of SSZ-102
[0065] The as-synthesized molecular sieve product of Example 1 was calcined inside a muffle furnace under a flow of air heated to 540° C. at a rate of 1° C./minute and held at 540° C. for 5 hours, cooled and then analyzed by powder XRD.
[0066] FIG. 3 shows a comparison of two X-ray diffraction patterns, the top one being calcined SSZ-102 as prepared in Example 10 and the bottom one being as-synthesized SSZ-102 as prepared in Example 1. The powder XRD pattern indicates that the material remains stable after calcination to remove the organic SDA.
[0067] For the purposes of this specification and appended claims, unless otherwise indicated, all numbers expressing quantities, percentages or proportions, and other numerical values used in the specification and claims, are to be understood as being modified in all instances by the term “about.” Accordingly, unless indicated to the contrary, the numerical parameters set forth in the following specification and attached claims are approximations that can vary depending upon the desired properties sought to be obtained. It is noted that, as used in this specification and the appended claims, the singular forms “a,” “an,” and “the,” include plural references unless expressly and unequivocally limited to one referent. As used herein, the term “include” and its grammatical variants are intended to be non-limiting, such that recitation of items in a list is not to the exclusion of other like items that can be substituted or added to the listed items. As used herein, the term “comprising” means including elements or steps that are identified following that term, but any such elements or steps are not exhaustive, and an embodiment can include other elements or steps.
[0068] Unless otherwise specified, the recitation of a genus of elements, materials or other components, from which an individual component or mixture of components can be selected, is intended to include all possible sub-generic combinations of the listed components and mixtures thereof.
[0069] The patentable scope is defined by the claims, and can include other examples that occur to those skilled in the art. Such other examples are intended to be within the scope of the claims if they have structural elements that do not differ from the literal language of the claims, or if they include equivalent structural elements with insubstantial differences from the literal languages of the claims. To an extent not inconsistent herewith, all citations referred to herein are hereby incorporated by reference. | A method for making a new crystalline molecular sieve designated SSZ-102 is disclosed using an N,N′-dimethyl-1,4-diazabicyclo[2.2.2]octane dication as a structure directing agent. SSZ-102 has ESV framework topology. | 1 |
BACKGROUND OF THE INVENTION
[0001] The present invention relates to optical fiber cables that have buffer tubes arranged in S-Z strands, and in particular a method of determining the lay length of such S-Z strands during the manufacturing process.
[0002] In telecommunication cables, optical fibers or optical fiber ribbons are often used as a medium to transmit optical signals. These cables often have a central strength member, such as a steel rod or stranded steel wires, that extends longitudinally along the central axis of the cable. As shown in FIG. 1 (from U.S. Pat. No. 5,229,851, which is incorporated by reference), central strength member 2 is intended to withstand and resist any tensile or compressive force applied axially to the cable 1 . The central strength member 2 is often encircled by a covering 3 , which may serve as a cushioning material. A plurality of plastic buffer tubes 4 - 8 surround covering 3 and loosely house protect optical fibers or ribbons within them. A binder thread or threads 17 and 18 are often contrahelically applied around buffer tubes 4 - 8 to hold them in place. A water swellable tape (not shown) may be applied over the buffer tubes to block water ingress into the cable. An overall plastic jacket 20 then covers the contents of optical fiber cable 1 . If the intended installation for cable 1 requires extra mechanical strength, the cable may include additional strength members in the form of armor or strength yarns 19 placed intermediate the water swellable tape and the jacket.
[0003] As shown in FIG. 1, buffer tubes 4 - 8 are generally wrapped around central strength member 2 in a reverse helix or “S-Z” fashion. The locations at which the stranded tubes reverse direction (e.g. from an “S” to a “Z”) are referred to as reversal points. S-Z stranding of buffer tubes in general, and the reversal points in particular, are advantageous for accessing the cable midspan. That is, due to the S-Z stranding, one or more optical fibers within the cable may be “tapped” at the reversal points without having to sever the cable or to carry out major reconfiguration. The S-Z stranding provides sufficient excess of tube length to make the tap easy by opening the side of the cable at a point along its length without losing the desired slack in the ribbon units or optical fibers within the tube that is opened. Thus, taps in an S-Z stranded cable can be made without interrupting other tubes or ribbon units.
[0004] To ensure that the optical fibers within the buffer tubes are not subjected to bending stress, which may cause unwanted attenuation, a parameter of the S-Z stranded buffer tubes called “lay length” needs to be monitored. Bending stress is a loss mechanism in optical fibers that may occur if the cable is subjected to tensile forces, either from installation or temperature, or compression forces. Bending stress may cause signal loss in the optical fibers. The S-Z strand of buffer tubes in an optical fiber cable may take several forms. Each ‘S’ turn may be followed immediately by a reversal to a ‘Z’ stranding direction. Alternatively, there may be several helical turns between reversals. In general, then, the average lay length is defined by the distance between reversal points divided by the number of turns between reversals.
[0005] The actual lay length of each individual S-Z stranded tube will vary from the average lay length by a small amount due to additional twisting and processing conditions. That is, the lay length of any given tube, may be more or less than the average lay length, as a given tube may make more than a whole number of turns between reversals. For example, in a cable with 6 different colored buffer tubes, one being red, and all S-Z stranded around a central member, the red tube may be at the top or at the 12 o'clock position on the cable at the first reversal point. But at the next reversal point the red tube may be at the 6 o'clock position on the cable, 3 tubes removed from the 12 o'clock position. Thus, the red tube has gone one half turn more between reversals. This half-turn must be included in the lay length calculation for the most accuracy. Thus, the actual lay length of a given S-Z stranded buffer tube is comprised of several components and can be calculated to close approximation by:
Lay Length= D/N,
where: N=N′+n/T
[0006] where D is the axial distance between the reversal points, N is the number of turns between reversals, and N′ is the number of whole turns between the reversal points; n is the number of tubes which a given tube is offset from its angular position on the previous reversal point, counted in the direction of rotation; and T is the total number of buffer tubes.
[0007] To protect against bending stress on the optical fibers, the lay length of the S-Z stranded buffer tubes is checked on finished cable to verify that the lay length is within acceptable specifications. The only way to check the lay length on finished cables is to strip back the jacket and other layers in the cable over the buffer tubes. It is not sufficient to do this on the cable ends as the start-up and finish of the stranding process may have been done at conditions that vary from the rest of the cable. Instead, lay length has been measured manually during the manufacturing process after stranding. The line operator would make the length measurement while walking alongside the progressing cable, which was fairly easy to accomplish accurately because line speeds were slow. More recently, however, line speeds have increased dramatically, making this type of manual measurement inaccurate. One alternative is to stop the line periodically to take measurements. However this is impractical and inefficient.
[0008] Many methods of determining the lay length of S-Z stranded optical fiber cables require the detection of lay reversal points of the S-Z stranded buffer tubes. One approach to the lay reversal detection problem is described in U.S. Pat. No. 5,809,194. In this patent, a process for marking an outer jacket of an oscillating lay cable (including S-Z stranding) to indicate the locations of the lay reversal points under the jacket is described. This process includes the step of providing detectable markings on an unjacketed cable core in predetermined positions relative to the lay reversal points. The process further includes the step of sensing the detectable markings with a sensor (such as a luminescence scanner) prior to extruding an outer jacket over the cable core. Next, the process includes predicting the location of the sensed markings on the cable core after a cable jacket has been extruded and providing markings on the cable jacket at predetermined positions relative to the predicted location of the sensed markings.
[0009] Another approach to the lay reversal detection problem is described in U.S. Pat. No. 5,745,628. In this patent, similar to the '194 patent, a process and apparatus for marking an outer jacket of an S-Z stranded cable to indicate the lay reversal points under the jacket is described. This process comprises passing a portion of a cable core within a field of view of an imaging means to acquire an image of that portion of the cable core. This imaging means includes a camera connected to a vision inspection/image acquisition system. The quantity of visually distinguishable conductors in the acquired image is compared to a reference value. If the reference value is exceeded, a lay reversal point is indicated. Once a lay reversal point is indicated, its position is tracked through an outer jacketing step. A marking to indicate the location of a lay reversal point is applied to the outer jacket according to the tracked position of the lay reversal point.
[0010] Yet another approach to the lay reversal detection problem is described in U.S. Pat. No. 5,729,966. In this patent, similar to the '194 and '628 patents, a method for marking sections of a fiber optic cable so that lay reversal points can be indicated on an exterior surface of the fiber optic cable is described. The method includes the steps of: 1) determining a current length value of the cable; 2) measuring an offset distance value, the offset distance being a length measurement between a lay reversal point of the cable and a marking device; 3) entering the offset distance value into a memory; 4) as a lay reversal point is being made, adding the current length value to the offset distance to define a sum value; 5) comparing the sum value to the current cable length value; and 6) when the sum value equals the current cable length value, activating the marking device, whereby the marking device marks the cable section.
[0011] None of these patents, nor any reasonable combination of them, teaches, suggests, or discloses a system or method of determining the lay length of S-Z stranded buffer tubes during the manufacturing process of a fiber optic cable. While the '194 patent discloses using a sensor to detect a mark placed on a lay reversal point, and the '628 patent discloses using a camera and vision inspection/image acquisition system to detect an unmarked lay reversal point, neither of them discloses using the detected lay reversal point to determine the lay length of S-Z strands during the manufacturing process.
[0012] Consequently, Applicants have discovered that conventional techniques do not provide a method or system to accurately measure the lay length of S-Z stranded buffer tubes during the manufacturing process without slowing down the manufacturing process and that conventional techniques do not automate the method or system such that the measurement data is stored for future reference.
SUMMARY OF THE INVENTION
[0013] In accordance with the present invention, a method and system for determining the lay length of S-Z strands during the manufacturing process are provided that avoid the problems associated with prior art methods and systems for determining the lay length of S-Z strands during the manufacturing process.
[0014] In one aspect, a method of measuring the lay length of buffer tubes S-Z stranded on an optical fiber cable core while advancing the core during manufacturing consistent with the invention includes capturing an image of the S-Z stranded buffer tubes containing at least two reversal points on the advancing core. Capturing an image may be accomplished by triggering a camera to take at least one image of the advancing core. In addition, capturing the image may be accomplished by capturing a plurality of preliminary images and splicing the plurality of preliminary images together. Once the image is captured, the method continues by downloading the captured image to a storage device and measuring the lay length of the S-Z stranded buffer tubes via the storage device. The method may include storing the captured image and the lay length measurement in the storage device or assembling the image into a bitmap on the displaying means.
[0015] Preferably, measuring the lay length may comprises positioning cursors at the reversal points on the displayed image and determining the distance between the cursors in order to determine the distance between the reversal points. In addition, measuring the lay length may include counting the number of complete turns between the two reversal points on the displayed image; determining the number of fractional turns between the two reversal points on the displayed image; and calculating the lay length. In calculating the lay length, the following relation may be used.
Lay Length= D/ ( N′+n/T )
[0016] In the above relation, D is the distance between the reversal points, N′ is the number of complete turns between the reversal points, and n/T is the fractional number of turns between the reversal points.
[0017] In another aspect, a system of measuring the lay length of buffer tubes S-Z stranded on an optical fiber cable core while advancing the core during manufacture consistent with the invention includes a camera configured to capture an image of the S-Z stranded buffer tubes containing at least two reversal points on the advancing core. The image may comprise a plurality of preliminary images spliced together. The system also includes a computer configured to receive the captured image and to determine the lay length of the S-Z stranded buffer tubes captured in the image. Preferably, the computer is configured to store the image and the lay length, and may be further configured to display the image. The computer may display the image by converting the image into a displayable format and placing the image on a display. The displayable format may be selected from the group comprising tagged image file format (tif), graphics interchange format (gif), joint photographic experts group format (jpeg), and bit map format (bmp).
[0018] Preferably, the computer is further configured to determine the lay length of the S-Z stranded buffer tubes by calculating the lay length using the following relation.
Lay Length= D/ ( N′+n/T )
[0019] In the above relation, D is the distance between the reversal points, N′ is the number of complete turns between the reversal points, and n/T is the fractional number of turns between the reversal points. N′ may be received through user input into the computer and D may be received through user input into the computer by the user positioning cursors at the reversal points of the image displayed by the computer. The computer may determine the distance D based upon the cursors' positions by detecting the two reversal points of the image and determining the distance D based upon the distance between the detected reversal points.
[0020] It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory only and are intended to provide further explanation of the invention as claimed. The following description, as well as the practice of the invention, set forth and suggest additional advantages and purposes of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
[0021] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate several embodiments of the invention and together with the description, serve to explain the principles of the invention.
[0022] [0022]FIG. 1 is a diagrammatical view of an exemplary fiber optic cable according to the present invention;
[0023] [0023]FIG. 2 is a functional block diagram of a system for determining the lay length of S-Z strands during the manufacturing process consistent with the present invention;
[0024] [0024]FIG. 3 is a flow chart of a method for determining the lay length of S-Z strands during the manufacturing process consistent with the present invention;
[0025] [0025]FIG. 4 is a flow chart of a subroutine, used in the method of FIG. 3, for capturing and uploading to the computer workstation the image data of the S-Z stranded buffer tube of the advancing cable core is;
[0026] [0026]FIG. 5 is a flow chart of a subroutine, used in the method of FIG. 3, for displaying the image data;
[0027] [0027]FIG. 6 is a flow chart of a subroutine, used in the method of FIG. 3, for calculating the lay length of the S-Z stranded buffer tube; and
[0028] [0028]FIG. 7 is a flow chart of a method for determining the lay length of S-Z strands during the manufacturing process consistent with an alternative embodiment of the present invention wherein an image recognition software module is utilized.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0029] Reference will now be made to various embodiments according to this invention, examples of which are shown in the accompanying drawings and will be obvious from the description of the invention. In the drawings, the same reference numbers represent the same or similar elements in the different drawings whenever possible.
[0030] Broadly stated, the invention is a system and method of monitoring the lay length of S-Z strands during the manufacturing process. More particularly, the present invention provides for determining the lay length of such S-Z strands during the manufacturing process without slowing down the manufacturing process.
[0031] [0031]FIG. 2 illustrates a system for determining the lay length of S-Z strands during the manufacturing process in accordance with a preferred embodiment of the present invention. Generally shown is a camera 205 which captures images of a buffer tube 105 that is stranded about a single cable core 110 , such as a central strength member. These images are captured while the fiber optic cable 100 is moving in a manufacturing line parallel to the lens of camera 205 . The fiber optic cable 100 need not be slowed in the manufacturing process in order to practice the invention, but rather the manufacturing line can be run at its normal line speed. As will be understood by one of ordinary skill in the art, a “normal line speed” depends on a variety of factors, including the type of cable being manufactured for a given cable, however, a normal line speed implies the typical or average speed of the cable over a period of manufacturing. Such line speeds are known by those skilled in the art.
[0032] Specifically, the images are captured when the fiber optic cable 100 is in the state of manufacture after the buffer tube has been S-Z stranded. Also, it is advantageous if the images are captured after binder threads have been wound around the stranded buffer tube to hold the buffer tube in position, but before a water swellable tape has been applied over the S-Z stranded buffer tube 105 . While FIG. 2 shows only one S-Z stranded buffer tube around cable core 110 , those skilled in the art will appreciate that a plurality of buffer tubes may be stranded about a single cable core 110 , such as in the fashion depicted in FIG. 1. The buffer tubes are different colored (completely colored or striped) so as to allow their identification by the user or by an image recognition software module, as described below. The present invention can be practiced when only one S-Z stranded buffer tube is stranded around the cable core 110 or when a plurality of buffer tubes are stranded about the cable core 110 .
[0033] The images captured by camera 205 are sent to a computer workstation 210 . Computer workstation 210 provides for displaying the images taken with the camera 205 on a display 215 , which may comprise a monitor. In addition, computer workstation 210 provides for executing programming modules that accept user input and calculate the lay length of the S-Z stranded buffer tube 105 during the manufacturing process without slowing down the manufacturing process. Input devices such as a mouse 220 and a keyboard 225 may be utilized to obtain user input in conjunction with the operation of the computer workstation 210 .
[0034] Preferred systems and methods of the present invention use a personal computer or other similar microcomputer-based equipment in implementing computer workstation 210 . However, those skilled in the art will appreciate that computer workstation 210 may comprise any type of computer such as hand-held devices, multiprocessor systems, microprocessor-based or programmable consumer electronics, minicomputers, mainframe computers, and the like. The computer workstation 210 may also be practiced in distributed computing environments where tasks are performed by remote processing devices.
[0035] [0035]FIG. 3 is a flow chart setting forth the general steps involved in an exemplary method 300 for determining the lay length of S-Z strands during the manufacturing process. The implementation of the steps of method 300 in accordance with an exemplary embodiment of the present invention will be described in greater detail in FIG. 4 through FIG. 6.
[0036] Exemplary method 300 begins at starting block 305 and proceeds to subroutine 310 where the image data of the S-Z stranded buffer tube 105 of the advancing fiber optic cable 100 is captured and uploaded to the computer workstation 210 . The steps comprising subroutine 310 are shown in FIG. 4 and will be described in greater detail below. Next, the method proceeds to subroutine 320 where the image data is displayed. The steps of subroutine 320 are shown in FIG. 5 and will be described in greater detail below. The method continues to subroutine 330 where the lay length of the S-Z stranded buffer tube 105 is calculated. The steps of subroutine 330 are shown in FIG. 6 and will be described in greater detail below. From subroutine 330 , exemplary method 300 ends at step 340 .
[0037] [0037]FIG. 4 describes the exemplary subroutine 310 from FIG. 3 in which the image data of the S-Z stranded buffer tube 105 of the advancing fiber optic cable 100 is captured and uploaded to the computer workstation 210 . Exemplary subroutine 310 begins at starting block 405 and proceeds to step 410 where the camera 205 is placed X distance from the fiber optic cable 100 . In practice, a distance of about 7 feet (i.e about 2.1 m) has been found to be optimal for the distance X, but those skilled in the art will appreciate that distance X will vary as a function of the physical conditions present and as a function of the type of camera 205 used. As mentioned, cable core 110 is in the state of manufacture after the buffer tube has been S-Z stranded, and after binder threads to hold the buffer tube in position have been contrahelically wound on the stranded buffer tube, but before a water swellable tape has been applied over S-Z stranded buffer tube 105 .
[0038] Once camera 205 is placed in step 410 , exemplary subroutine 310 advances to step 420 where the camera 205 is used to capture the image data. Camera 205 may comprise a digital camera that records images in a digital file. Unlike traditional analog cameras that record infinitely-variable intensities of light, digital cameras record discrete numbers for storage on a flash memory card, floppy disk or hard disk. As with all digital devices, there is a fixed, maximum resolution and number of colors that can be represented.
[0039] Camera 205 is triggered by the user to capture the image data. This triggering can be facilitated by a programming module in the computer workstation 210 . Specifically, the user enters instructions into the computer workstation 210 , which in turn causes the camera 205 to capture the image data. Those skilled in the art will appreciate that the triggering of camera 205 and thus the capturing of the image data may be accomplished by other processes including automatically detecting the reversal oscillations of the strandings, taking into consideration a distance or time adjustment. The images may be transferred to the computer workstation 210 with a serial cable, USB cable or similar technique, or via the storage medium itself if the computer workstation 210 has a counterpart reader. Digital cameras record color images as intensities of red, green and blue, which are stored as variable charges in a CCD matrix. The size of the matrix determines the resolution, but an analog-to-digital converter (ADC), which converts the charges to digital data, determines the color depth.
[0040] After the camera 205 is used to capture the image data in step 420 , exemplary subroutine 310 advances to step 430 where the image data is uploaded to the computer workstation 210 . From step 430 subroutine 310 continues to step 440 and returns to subroutine 320 of FIG. 3.
[0041] [0041]FIG. 5 describes exemplary subroutine 320 from FIG. 3 in which the image data is displayed. Exemplary subroutine 320 begins at starting block 505 and proceeds to step 510 where the computer workstation 210 receives the image data. Once the computer workstation 210 receives the image data in step 510 , exemplary subroutine 320 advances to decision block 520 where it is determined if the image data comprise a plurality of preliminary image files. A plurality of preliminary image files may result if, for example, camera 205 was programmed to take a series of pictures of the cable core 110 . The capturing time of camera 205 is selected based on the line speed of the advancing fiber optic cable 100 . In order to calculate accurately the lay length of the S-Z stranded buffer tube 105 , at least two reversals of the S-Z stranded buffer tube 105 should be captured in the image data. Therefore, camera 205 may be controlled to capture a plurality of preliminary image files if at least two reversals cannot be captured in a single image file. The calculation of the lay length is discussed in greater detail with respect to FIG. 6.
[0042] If the image data does in fact comprise a plurality of preliminary image files, subroutine 320 advances to step 530 where the plurality of preliminary image files are spliced to create a resulting image file capable of being displayed. The splicing of the plurality of preliminary image files can be achieved, for example, by using an industry standard of image correlation. Image correlation is a method of taking two pictures and overlapping them in different positions and measuring the color difference of the two overlapping areas. The position yielding the least color difference becomes the location of the picture splice. The spliced image will depict a longer segment of the moving cable than any of the individual image files could show.
[0043] If at decision block 520 it is determined, however, that the image data does not comprise a plurality of preliminary image files, subroutine 320 continues to step 540 where the image data is converted to a resulting image file capable of being displayed. The resulting image file can be in a variety of different file formats. For example, the image file format and corresponding file extensions can comprise at least any one of the following: tagged image file format (.tif), graphics interchange format (.gif), joint photographic experts group format (.jpg), and bit map format (.bmp). However, embodiments of the present invention envision that any other file formats for the image data will suffice. From step 530 or from step 540 , exemplary subroutine 320 advances to step 550 where the resulting image file is displayed on the display 215 . From step 550 , subroutine 320 continues to step 560 and returns to subroutine 330 of FIG. 3.
[0044] [0044]FIG. 6 describes the exemplary subroutine 330 from FIG. 3 in which the lay length of the S-Z stranded buffer tube 105 is calculated. Exemplary subroutine 330 begins at starting block 605 and proceeds to step 610 where a selectable control element is positioned by a user on the first reversal point 115 of the S-Z stranded buffer tube 105 shown on the resulting image file as displayed on the display 215 . For example, the user may manipulate an input device such as mouse 220 , causing the corresponding movement of a selectable control element on the display 215 . The aforementioned selectable control element may comprise a cursor. Those skilled in the art will, however, appreciate that other input devices may be utilized as well as other selectable control elements.
[0045] Once the selectable control element is positioned by the user on the first reversal point 115 in step 610 , exemplary subroutine 330 advances to step 620 where the selectable control element is positioned by the user on the second reversal point 120 of the S-Z stranded buffer tube 105 shown on the resulting image file as displayed on the display 215 . After the selectable control element is positioned by the user on the second reversal point 120 in step 620 , exemplary subroutine 330 advances to step 630 where the distance between the first reversal point 115 and the second reversal point 120 of the S-Z stranded buffer tube 105 is calculated. Computer workstation 210 detects the aforementioned positioning of the selectable control element on the resulting image file as displayed on the display 215 and executes a programming module to calculate the distance between the first reversal point 115 and the second reversal point 120 . To facilitate this calculation, a calibration is performed on the system prior to its use in the manufacturing process. This calibration is accomplished by capturing a calibration image of a measuring device, a scale for example, placed behind a sample stranded core. This calibration image is then used to determine a pixel-to-length ratio utilized in subsequent calculations of the distance D between the first reversal point 115 and the second reversal point 120 .
[0046] After the distance between the first reversal point 115 and the second reversal point 120 of the S-Z stranded buffer tube 105 is calculated in step 630 , exemplary subroutine 330 advances to step 640 . At step 640 , the user enters the number of turns the S-Z stranded buffer tube 105 makes around cable core 110 between first reversal point 115 and second reversal point 120 . For example, the user may enter the number of turns between the first reversal point 115 and the second reversal point 120 by typing a response into the keyboard 225 . Alternatively, the user could use the mouse 220 in conjunction with a graphical user interface (GUI) displayed on display 215 . A GUI incorporates drag and drop features, icons, and pull-down menus, and preferably uses a mouse. The type of GUI is not significant and may be a WINDOWS, MACINTOSH, or MOTIF GUI, and, in a client/server environment, preferably resides on the client terminal. Those skilled in the art will appreciate that other processes may be used to enter user data.
[0047] After the user enters the number of turns between the first reversal point 115 and the second reversal point 120 of the S-Z stranded buffer tube 105 in step 640 , exemplary subroutine 330 advances to step 650 where the lay length of the S-Z stranded buffer tube 105 is calculated. Computer workstation 210 executes a program module to calculate the lay length of the cable. This calculation is based on the distance D between first reversal point 115 and second reversal point 120 and the number of turns the S-Z stranded buffer tube 105 makes around the cable core 110 between first reversal point 115 and second reversal point 120 as follows:
Lay Length= D/N,
where: N=N′+n/T
[0048] D is the axial distance between the reversal points; N is the number of turns between reversals; N′ is the number of whole turns between the reversal points; n/T is number of fractional turns, where T is the number of tubes being stranded, and n is the number of tubes which a given tube is offset from its position at the previous reversal point, counted in the direction of rotation. For example, consider the following construction: a six-tube construction, with the sequence of tubes: white, blue, red, green, brown, orange; the white tube is at the top of the cable in the captured image at the first reversal point and the red tube is at the top of the cable in the captured image at the subsequent reversal point. n/T is determined as follows: T=6; n=2 as the white tube is 2 tubes removed from its position at top of cable from last reversal. Note that in this example, the white tube may not be visible at the reversal point. Therefore n/T=⅓, that is the white tube (as well as the other tubes) has gone through and additional ⅓ turn.
[0049] This calculated lay length may be displayed on the display 215 , and the resulting image file, data entered by the user, and lay length of the S-Z stranded buffer tube 105 may be saved together in a file for future reference. From step 650 subroutine 330 continues to step 660 and returns to step 340 of FIG. 3.
[0050] [0050]FIG. 7 is a flow chart setting forth the general steps involved in an exemplary method 400 which is an alternative embodiment of the present invention for determining the lay length of S-Z strands during the manufacturing process utilizing an image recognition software module. Exemplary method 400 begins at starting block 705 and proceeds to exemplary subroutine 310 where the image data of the S-Z stranded buffer tube 105 of the advancing fiber optic cable 100 is captured and uploaded to the computer workstation 210 . The steps comprising subroutine 310 are shown in FIG. 4 and were described in great detail above.
[0051] From exemplary subroutine 310 where the image data of the S-Z stranded buffer tube 105 of the advancing fiber optic cable 100 is captured and uploaded to the computer workstation, exemplary method 400 proceeds to step 720 where the distance D between first reversal point 115 and second reversal point 120 and the number of turns the S-Z stranded buffer tube 105 makes around the cable core 110 between first reversal point 115 and second reversal point 120 are determined using the image recognition software module executed on computer workstation 210 . Generally, image recognition software programs have the ability to analyze digital images contained in data files and to distinguish features found within the image data. The image recognition software module of this embodiment is able to track a particular buffer tube by its color and also to determine if the slope of the tube is positive, negative, or neutral. In particular, the slope is considered as positive, negative or neutral, when the tube defines, in the image, a positive, negative, or zero angle with the axis of the cable.
[0052] This ability of the software allows detecting a reversal point during the passage of the cable. This is done differently when the neutral-slope portion of the tracked tube is directly shown on the captured image or when the same portion is not directly shown (this last case occurring when the tube is in the opposite part of the cable with respect to the camera at the reversal point). When the neutral-slope portion of the tracked tube is directly shown, the software module marks the point of the cable where this neutral-slope portion is detected and identifies this cable point as the reversal point. If the neutral-slope portion of the tracked tube is not shown, the software module can in any case detect the change of slope of the tracked tube and thereby identify the axial position of reversal point. For instance, if the slope changes from positive to negative, the software module will act as follows. First, it will mark the last visible point of the tracked tube having a positive slope and then it will mark the first visible point having a negative slope. Then, the software module determines the point that is halfway from the two marked points and identifies this halfway point as the reversal point of the cable. The distance between the two marked points also allows determining the circumferential position of the tracked tube at the reversal point of the cable. Differently, when the tube is directly shown in the image of the reversal, its circumferential position can be directly determined by the software module.
[0053] Being able to detect the axial position of the reversal points of the cable and the circumferential position of the tracked tube in correspondence of each reversal point, the software module can easily measure the distance D between two consecutive reversal points and the number of turns of the tracked tube between the same points.
[0054] The distance D can, for example, be obtained by multiplying the time between two reversal point detections and the velocity of the advancing cable. To measure the number of whole turns N′ and the fraction of turn n covered by the tracked tube between two reversal points, the software module counts occurrences of the tracked tube along the axis of the cable, starting from the detection of the last reversal point and ending at the detection of the subsequent reversal point, and also takes into account the relative circumferential position of the tracked tube in correspondence of the two reversal points and the slope of the tracked tube between the two reversal points.
[0055] For illustration purposes, consider a cable having a six-tube construction, with the following sequence of tubes: white, blue, red, green, brown, orange; the white tube is at the top of the cable (the reference position) in the captured image at the first reversal point and the green tube is at the top of the cable in the captured image at the subsequent reversal point. In this example the white tube neutral slope section is not visible in the image of the second reversal point. By comparing the circumferential positions of the white tube at the two reversal points, the software module will determine that an additional ½ turn has to be added to the whole number of turns of the tube.
[0056] From this analysis, the position of first reversal point 115 and second reversal point 120 , the number of turns between first reversal point 115 and second reversal point 120 , and the fractional turns between first reversal point 115 and second reversal point 120 can be determined without user input. From the determination of the position of first reversal point 115 and second reversal point 120 , the image recognition software module can determine the distance D between first reversal point 115 and second reversal point 120 .
[0057] From step 720 where the distance D between first reversal point 115 and second reversal point 120 and the number of turns the S-Z stranded buffer tube 105 makes around the cable core 110 between first reversal point 115 and second reversal point 120 is determined using the image recognition software module executed on computer workstation 210 , exemplary method 400 advances to step 730 where the lay length of the S-Z stranded buffer tube is calculated. Computer workstation 210 executes a program module to calculate the lay length of the cable. This calculation is based on the distance D between first reversal point 115 and second reversal point 120 and the number of turns the S-Z stranded buffer tube 105 makes around the cable core 110 between first reversal point 115 and second reversal point 120 , in the manner described above with respect to FIG. 6. This calculated lay length may be displayed on the display 215 , and the resulting image file, data entered by the user, and lay length of the S-Z stranded buffer tube 105 may be saved together in a file for future reference. From step 730 where the lay length of the S-Z stranded buffer tube is calculated, exemplary method 400 continues to step 740 and ends.
[0058] In view of the foregoing, it will be appreciated that the present invention measures the lay length of S-Z strands during the manufacturing process. Still, it should be understood that the foregoing relates only to the exemplary embodiments of the present invention, and that numerous changes may be made thereto without departing from the spirit and scope of the invention as defined by the following claims. | A system and method for determining the lay length of S-Z stranded buffer tubes during the manufacturing process of a fiber optic cable without slowing down the manufacturing process. Images of an S-Z stranded buffer tube are captured with a camera. The images are sent from the camera to a computer workstation. The computer workstation displays the images taken with the camera and executes programming modules that calculate the lay length of the S-Z stranded buffer tube during the manufacturing process of the cable. Input devices such as a mouse and a keyboard may be used in conjunction with the operations of the computer workstation. By measuring the lay length during cable manufacture, productivity may be maintained while ensuring that the stranding of buffer tubes does not fall out of tolerance, which might result in deleterious bending stress of optical fibers within the buffer tubes. | 3 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The invention relates to a remote control for a receiver, more particularly for a television set.
2. Description of the Prior Art
In local receiver networks, as operated in hotels and clinics or hospitals, in particular in so-called pay TV networks having individual pay TV channels in addition to the usual station channels of private and public broadcasting stations, keeping a record of reception or viewing time of channels subject to payment, namely pay TV channels, necessitates a special technical reequipment for the pay TV operator. In known pay TV systems the viewing hours relevant to individual television sets are each signalled via a separate line from each television set to a central accounting point and from there in conclusion to final invoicing of the guest or patient at the end of his stay in the hotel or hospital. Due to the lines and circuitry necessary for this purpose central accounting is highly complicated.
Television sets are already known for which authorization cards can be acquired by purchasing. These authorization cards are introduced into a card reader, a so-called swipe, in the television set which is then unblocked. The drawback of this solution is that constructional changes need to be made to the television set.
DE 42 17 649 A1 discloses using a swipe to unblock a television set or telephone, the swipe being included in a bed control unit. This bed control unit comprises entry keys which can be used for switching the television set ON/OFF and for channel selection. As an alternative it is proposed to eliminate these entry keys on the bed control unit and to provide instead a telephone or an infrared control means. As a further alternative the entry keys are to be provided on the swipe.
In DE 42 17 648 A1 a bed control unit having a swipe is disclosed, the control unit being connected to a control means in a remote control means, whereby headphones are connectable to the remote control means and unblocking use of a television set follows depending on the information stored in a swipe card.
DE 42 18 125 A1 shows that a control unit having the form of a telephone receiver can be used for remote control of a display monitor, an authorization check being implemented in the telephone receiver as to whether the user of the telephone receiver has authority to use a television set or not. It is proposed that this check be made via a corresponding chip card.
In EP-A-317404 a pay TV system is described in which a card reader is provided in the television set.
FR-A-2696888 discloses a remote control in which the function of the remote control can be determined by a plug-in storage card.
In DE-A-4212200 a remote control system is disclosed which serves to operate household appliances by using an IC card and a remote public telephone capable of processing said IC card via a public telephone network.
The aforementioned devices have, however, the disadvantage that monitoring ON of the television set necessitates means of a relatively complex configuration and installing these means is relatively complicated.
SUMMARY OF THE INVENTION
The invention thus has the object to simplify, and thus also to make cheaper, means for monitoring ON of various television sets including the devices necessary therefor such as e.g. remote controls and, where desired, clocking the ON times of individual or all program channels of a receiver.
This object is achieved by a cordless remote control for a television set of a pay TV system comprising a reader for a data medium, said data medium containing information for activating said remote control and/or at least one program channel of said receiver, wherein said remote control is assigned a code (C); and said remote control comprises a device for writing said code (C) of said remote control on said data medium, a device for reading said code (C) from said data medium on said remote control, and a device for comparing said read code (C) to said code (C) of said remote control and for controlling the unblocking of said remote control; and a method of unblocking a remote control for a television set of a pay TV system, wherein a code (C) assigned to said remote control is written onto a data medium by a writer integrated in said remote control; said code (C) store on said data medium is read by said remote control; said code (C) assigned to said remote control is compared to said code (C) read from said data medium; and it being established from said comparison whether said data medium has already been used for unblocking some other remote control.
In accordance with the invention a reader for a data medium containing information for activating the remote control and/or least a program channel of the receiver, for instance a chip or magnetic strip card, a perforated strip card, an optical or other suitable data medium, is arranged in or on a remote control or the housing thereof. There remote control is assigned a code, this code being written on the data medium by a device of remote control, read from the data medium and compared to the code of the remote control.
By means of this data medium reader the remote control itself and/or a program channel of a receiver is activated when the receiver type is correspondingly specified and/or the data medium introduced into the reader is recognized by it to be valid. For this purpose the control data for various receiver types can be stored on the card. Especially preferred is an arrangement in which a program key or a power ON key of the remote control itself is unblocked.
By arranging the data medium reader in or on the remote control the additional wiring systems hitherto necessary for known pay TV networks are eliminated as a result of which the network itself or its installation can be substantially simplified and made cheaper. In addition, a remote control configured as such can be used for signalling various receiver types. Converting receivers, as mandatory in the case of swipe means mounted on the unit itself, is also eliminated. Thus, a pay TV operator can operate his network with no change until he is in possession of remote controls configured in accordance with the invention which he then simply needs to replace for the remote controls used hitherto. More particularly, in changing from central booking to a localized decentralized booking there is no need for him to convert or even totally replace his expensive television sets.
The data medium reader is preferably integrated in the remote control which presents no problem for a series of conventional remote controls due to ample space being available. Otherwise a somewhat large housing would need to be provided for a remote control.
In accordance with a particularly preferred embodiment of the invention the reader is configured as a reader/writer combination. This makes it possible not only to verify the validity of an inserted data medium by the read procedure but also to write the data medium following selection of an unblocked program channel or an unblocked key of the remote control to register the unblocking action on the data medium. It is particularly preferred to further connect such a reader/writer to a time counter to also note on the data medium the time units clocked by a time counter corresponding to the viewing time of the unblocked program channel. On the other hand the data medium stores information as to whether one or more program channels are unblocked, or the number of unblock actions still available or the duration of allocated remaining viewing time. It is likewise in keeping with the invention when the time of unblocking and end of the time allocated for viewing is noted on the card. If it is merely desired to operate various receiver types with the remote control, then the writer can be eliminated.
It is especially simple, and convenient for the hotel guest or the patient in a hospital or his visitors when the data medium permits a large number of unblock procedures or a lengthy duration of use. The data medium can be procured by purchase once by the user, used until the end of its duration and then simply disposed of. This also affords maximum rationalization for the operator of receivers to be unblocked, for instance a pay TV operator, since namely using his system does not need to be invoiced individually for each user. Valid data media need merely to be made available or sold. If necessary, the used data medium may be returned and put back into circulation after having been updated or reprogrammed.
In a preferred embodiment the data medium carries the information needed to signal a plurality of different receiver types with the remote control. Selecting the desired type in each case can be done either on the remote control itself by swapping the data with the corresponding receiver or by the user via a key pad of the remote control. For implementing the aforementioned functions it is not a mandatory requirement that further information, in addition to that needed to signal the various types of receivers, exists on the card.
The invention is preferably employed in hotel and hospital pay TV networks, a pay TV network for the purpose of the invention being understood as a local closed circuit having its own transmitting station and television sets connected thereto which are often of different types. The station produces its own programs, more particularly video films, which can be distributed in the closed circuit to the connected television sets and dialled into by the users. In addition each television set is able to receive program channels broadcasted from outside the network. For recording the viewing times of the program channels, likewise simply termed pay TV, covering a large viewing area, for example, "Premiere", the invention can be put to use likewise to advantage.
The receiver type selection possible with the remote control in accordance with the invention can be put to use to advantage on pay TV networks having differing types of receivers.
Television sets in conventional pay TV networks feature a series of program channels received from private or public broadcasting stations and made available to the user at no charge, as well as a series of program channels for which payment is due which are distributed to the individual receivers of the pay TV network for example via closed-circuit video systems. In this case in general only these pay program channels need to be unblocked, whilst the remaining channels can be made use of without a valid data medium.
The invention can also be put to use to advantage in private applications. Thus, a child lockout may be employed to advantage.
In this case, also as regards pay TV networks, also all program channels may be locked out and unblocked only by insertion of a valid data medium, unblocking of simply a central power ON button also being sufficient, should such a button be provided.
In the case of a local network of receivers via which the pay program channels can be received, as is the case in pay TV, each remote control is preferably assigned to a specific receiver. This prevents abuse resulting from a user, after first-time unblocking of his remote control, gaining access to other receivers, likewise needing unblocking, without being required to pay for the use thereof. Receivers are already available on the market which have a sensor incorporated, preset to the emitter of a specific remote control or which can be set thereto.
Since, however, not all manufacturers offer such preset or settable receivers and the by far majority of receivers in use do not as yet include this desirable additional feature, a preferred embodiment is proposed by which modifications are needed simply in the remote control and an additional emitter/sensor is assigned to the receiver not necessitating any constructional changes on the receiver itself, however.
This device can be eliminated, however, when the receiver type is specified to the remote control, it then being possible to detect unblocking of program channels of other receivers by the data exchange between remote control and receiver. In addition, receivers of the same type can be made distinguishable for the remote control e.g. by allocating ID numbers.
In accordance with a first embodiment of the invention the data medium is "individualized", i.e. rendered usable only for one specific receiver or a specific remote control and in a second embodiment the remote control itself is usable only for a specific receiver.
For identifying the receiver as being "operable" or "non-operable" an emitter/sensor is applied to the receiver or in its vicinity. When the power key or the program key to be unblocked on the remote control is pressed the remote control first emits an ID signal which is sensed and identified by the emitter/sensor. If the emitter/sensor "sees" the signal received from the remote control as being OK, it in turn sends an OK signal back to the remote control. This signal is received by the remote control which in turn is equipped in accordance with the invention, with a corresponding sensor. It is not until such a signal is received and a valid data medium recognized by the reader that the remote control is unblocked.
In a further preferred embodiment of the invention the remote controls themselves may be coded, the code specified for a remote control then being written on a chip card after it has been inserted in a corresponding writer/programmer for programming. This code stored on the chip card can be read by the remote control. By comparing the code assigned to the remote control and the code read onto the chip card it can be established whether this chip card has already been used for unblocking another remote control. It can thus be prevented that a single chip card is used to unblock more than one remote control. This is important e.g. in the case of hotel pay TV systems with which the guest as a rule is able to switch on the television set as often as he likes over 24 hours for a fixed (invoiced) fee. In an alternative preferred embodiment the code must first be written on the chip card, e.g. when the chip card is purchased, to be able to operate a specific remote control coded with this code.
A further preferred embodiment of the invention provides for the chip card needing to remain in the remote control to permit certain program channels to be unblocked, these channels possibly being solely pay TV channels or pay TV channels and regular no-charge channels.
Although these embodiments are unable to prevent identical television sets, the sensor signal of which is not codable, from being switched on by one and the same remote control, they do ensure that the card itself cannot be used to unblock several remote controls (and thus television sets).
Should, for instance, in a hospital two television sets exist in a sick-room, then only one television set can be unblocked at any one time since ejecting the chip card from the remote control would automatically result in the remote control concerned, and thus the unblocked television set or its pay TV program, being switched off.
In yet a further embodiment of the invention a chip card can be used to unblock various remote controls, the different codes of the unblocked remote controls being stored on the chip card. Accordingly, all unblock actions of the various remote controls are stored on the chip card and can be correspondingly invoiced or debited after use.
BRIEF DESCRIPTION OF THE DRAWINGS
Preferred example embodiments of the invention will now be described relative to the attached drawings disclosing further features and advantages of the invention, in which:
FIG. 1 illustrates a remote control in accordance with the invention,
FIG. 2 illustrates a first embodiment of the remote control as shown in FIG. 1,
FIG. 3 illustrates a second embodiment of the remote control as shown in FIG. 1,
FIG. 4 illustrates a remote control in accordance with the invention having an additional sensor.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
FIG. 1 illustrates a remote control 50 having a slot 32 for inserting a data medium 40, in this example embodiment a chip card, in the region of a reader/writer 30 (FIG. 4) integrated in the remote control 50. By means of this remote control 50 a receiver 60 is operated which is connected to a local network, namely a pay TV network. The remote control 50 is provided with a power key 10 and program keys 1-9 and 0 as well as non-identified user keys via four program keys P1-P4 for selecting one of four pay program channels. It will readily be appreciated that the program keys may be replaced by a single button rocker.
FIG. 2 shows a first embodiment of the remote control in accordance with the invention in which merely the pay TV program channels P1-P4 of the television set 60 need to be unblocked for viewing by the user. In this example embodiment unblocking is done solely by unblocking the corresponding program keys P1-P4 on the remote control, whilst on the television set 60 no constructional changes are needed to disable or unblock the program channels P1-P4.
A signal path leads from each of the program keys 1-9 and 0, the power key 10 and the pay TV program keys P1-P4 to an emitter 28 of the remote control 50. The corresponding signal leads 11-24, 29 of the cited keys lead in conclusion via the signal lead 27 to the emitter 28, which in this example embodiment is an infrared. Depending on which key has been pressed the emitter 28 transmits a chararacteristic emission signal S which is received by the corresponding sensor 62 of the television set 60. As far as the program keys 1-9, 0 and the power key 10 are concerned the remote control 50 shown in FIG. 2 corresponds co a conventional remote control. The user has no trouble selecting each of the program channels set on the television set 60 and selectable by pressing the corresponding program key. The emitter 28 of the remote control 50 will not receive any input signal via the signal lead 27 when one of the pay TV program keys P1-P4 is pressed and no chip card 40 is inserted in the slot 32 indicated in FIG. 1.
In accordance with a very simple embodiment of the invention this is achieved by the signal leads 21-24 leading from the program keys P1-P4 and finally via the signal lead 27 to the emitter 28 of the remote control 50 being open-circuited and not being reclosed by a reader in the example embodiment (not shown in FIG. 2) until a chip card 40 recognized by this reader as being valid is properly inserted.
FIG. 3 shows a further embodiment of a remote control 50 in accordance with the invention. In this variant all program keys 1-9, 0 and the power key 10 need to be unblocked by means of the chip card 40. The further details of this embodiment as shown in FIG. 3 correspond to those as illustrated in FIG. 2.
In the example embodiment illustrated in FIG. 4 the remote control 50 comprises in addition to the emitter 28 also a sensor 29. Fitted to the television set 60 is an additional emitter/sensor 62 which receives the ID signal I from the emitter 28 of the remote control and, in turn, sends a authorization signal A when the ID signal I is "seen" by the emitter/sensor 62 as being an authentic signal; otherwise the emitter/sensor 62 remains mute. It is to be noted that the emitter/sensor 62 may be physically connected to the television set but not necessarily so, there existing no electrical or other signal connection between the emitter/sensor 62 and the television set 60.
It will readily be appreciated that this modification is to be made only on receivers which have not already been dedicated by the manufacturer to the signals of a specific remote control or provided with means of adjustment, e.g. for a pay TV operator.
The remote control 50 illustrated in FIG. 4 comprises a key pad 25 comparable to that of the remote control 50 shown in FIG. 1.
The signal leads 11-24, 29, indicated separately in FIGS. 2 and 3, are signified in FIG. 4 by the lead bus L. The lead bus L connects an input of a suitable circuit or a processor 26 which comminicates via a further data bus 31 with the reader/writer 30. Via lead bus L the processor 26 receives the information as to which of the keys of the key pad 25 have been pressed. If the pressed key involved is one requiring prior unblocking--which may be the pay TV keys P1-P4 or all program keys--the processor 26 will only output a control signal to the emitter 28 via the signal lead 27 when it has received the information from the reader/writer 30 via the bus 31 that a valid chip card 40 is inserted.
In identification and authorization in accordance with the invention the emitter 28 outputs an ID signal I as a first signal individual to the remote control concerned, intended for the emitter/sensor 62. The emitter/sensor 62 establishes whether the emitted ID signal I is authentic or not. When signal I is authentic, the emitter/sensor 62 in turn sends an authorization signal A which is received by the sensor 29 of the remote control 50. The sensor 29 in turn passes on the authorization signal A to the processor 26. It is only when the processor 26 has received such an authorization signal A from the sensor 29 right from the start and then the further conditions as cited above are satisfied that the processor passes on a power ON or program select signal S to the emitter 28 of the remote control 50 which in turn sends the signal S to the sensor 61 of the television set 60, this sensor 61 being one of the usual sensors for remote control signals.
In still a further embodiment of the invention which may also be designed without the devices and methods described above, the remote control 50 comprises a reader 30, preferably also a reader/writer 30, into which the chip card 40 can be inserted. Stored on this chip card 40 is information as to various types of receivers so that following entry of a code for specifying the receiver type via the key pad 25, control signals for controlling the emitter 28 of the remote control 50 can be generated by the processor 26 of the remote control 50 so that the existing receiver type can be signalled. Likewise, all signals emitted by the television set 60 can be received by the sensor 29 of the remote control 50 and correctly processed by the processor 26 since the type of the receiver is known to the latter. Accordingly, different types of receivers can be signalled by means of the above remote control in conjunction with the chip card 40.
In yet another preferred embodiment of the invention the code for specifying the type of receiver need not be entered via the key pad 25. For this purpose the remote control 50 first sends one or more ID signals I to the television set 60 when the corresponding key is pressed in the key pad 25. The television set "sees" the presence of the control wanted by the remote control 50 and sends an answer signal A back to the remote control 50, after having received the ID signal I, this answer signal being received by the sensor 29. Contained in the answer signal A of the television set 60 is information as to the type of receiver concerned. Following receipt of the answer signal A this information can be decoded by the processor 26 of the remote control 50 so that the processor 26 is able to adapt the operating requests to the corresponding type of receiver via the key pad 25 and forward via the signal lead 27 corresponding control signals to the emitter 28 of the remote control 50, these control signals then being received by the sensor 61 of the television set 60 and subsequently correctly decoded as to their meaning.
Thus, the remote control 50 can be activated as a function of the selection specific to the type of receiver involved. | A cordless remote control for a receiver, more particularly for a television set, comprising a reader for a data medium, said data medium containing information for the activating the remote control and/or at least one program channel of said receiver. | 7 |
REFERENCE TO PRIOR APPLICATION
This application is a continuation-in-part of U.S. application Ser. No. 731,212, filed Oct. 12, 1976, which is a divisional application of U.S. application Ser. No. 607,506, now U.S. Pat. No. 3,993,799 which is a continuation-in-part of U.S. application Ser. No. 512,224 filed Oct. 4, 1974 now abandoned.
BACKGROUND OF THE INVENTION
Electroless or autocatalytic coating of dielectric surfaces is a well known process finding wide-spread utility in the preparation of such diverse articles as printed circuits, automotive trim, mirrors, etc.
Normal commercial electroless coating processes generally involve an initial cleaning and etching of the dielectric substrate by physical or chemical means to improve adherence of the metallic coating. The etched surface is then catalyzed by suitable catalytic compositions and processes to provide a surface capable of electroless plating initiation. In the prior art, the catalytic treatment generally encompassed the use of precious metals. More recently, compositions and processes utilizing non-precious metals have been disclosed suitable for electroless plating of dielectrics. U.S. Pat. Nos. 3,993,491, 3,993,801, 3,993,799, 3,958,048, 4,048,354, and Ser. Nos. 645,198 and 720,588, now U.S. Pat. No. 4,082,899 which are included herein by reference disclose the prior art as well as the recent advancements in which non-precious metals have been reported.
In reviewing the teachings disclosed in U.S. Pat. Nos. 3,993,799 and 3,958,048 it is evident that colloids or either hydrous oxides, metals (elemental state) and alloys (phosphides, borides, nitrides, etc.) are useful in the catalytic treatment either as a two step or a single step activation treatment. Generally speaking, preferred metals in the above colloids are cobalt, copper, iron and nickel, although as suggested in U.S. Pat. No. 3,993,799 other non-precious metals may be used. It is recognized that it is generally desireable to have suspensions (dispersions) of very fine particulate matter for both stability (i.e., against precipitation), reactivity, and adhesion to the substrate. Accordingly, it is highly desirable to prepare such suspensions under conditions which would yield finely divided and highly stable colloids.
It is also well recognized in the art of electroless plating that for effective electroless plating onto catalytically treated non-conductors at least one of the following requirements must be met:
Case I: The catalytic surface may react chemically with the reducing agents presents within the electroless plating bath. More than one chemical reaction may take place.
Case II: The catalytic surface may react chemically with the metallic ions present within the electroless plating bath in a galvanic type replacement reaction.
In Case I, the chemical reactions may range from chemical reduction of the catalytic components present on the dielectric, and/or decomposition of the reducing agent at the interface ultimately yielding hydrogen gas via an active reducing agent intermediate. In Case II, to permit a galvanic replacement reaction, it is recognized that some of the metal ions present in solutions must be more noble with respect to the metal and metal ions present on the treated non-conductor surface. Such relationship is well recognized from the EMF series. Thus, while metals like copper, cobalt, nickel and iron may be preferred as recognized in U.S. Pat. No. 3,993,799, yet other non-precious metals may also be of potential use (e.g., zinc, manganese, etc.). It is further recognized that it is highly desireable to have catalysts which when contacted with the chemical (electroless) plating bath will yield short induction times. Generally speaking it is recognized that whenever the induction time is short, the probability for complete metallic coverage is excellent and thus eliminates the problem of skip plating.
SUMMARY OF THE INVENTION
It is the principle object of the present invention to provide an effective and economical process and compositions for preparing dielectric substrates for electroless coating or plating of a metallic surface thereon, and to provide an electroless coating process including such preparation.
It is a particular object of the present invention to provide improved compositions through which the catalytic activity would be increased. Other objectives of the present invention, if not specifically set forth herein, will be apparent to the skilled artisan upon the reading of the detailed description of the invention which follows.
Surprisingly, it has been discovered that the aforesaid objectives may be achieved by a process and compositon which render the colloidal composition a greater reactivity and hence provide a greater catalytic activity for the colloid when adsorbed onto the non-conductors. The improved compositions incorporate the additions of metallic ions (e.g., nickel) subsequent to the nucleation of the colloidal dispersion comprising copper.
DETAILED DESCRIPTION OF THE INVENTION
The process of the present invention is applicable to metallic plating of a wide variety of dielectric (non-conductor) substrates. Dielectric substrates described in the prior art, including thermoplastic and thermosetting resins and glass, may also be suitably plated in accordance with the present invention. Normally, these substrates will be cleaned and surface treated prior to plating in order to improve adherence of the metallic coating. The present invention is an improvement to the processes and compositions disclosed in the above cited references.
The colloids of the present invention are generally prepared by adding the selected compound of a catalytic metal or a salt thereof, e.g., the sulfate, nitrate, chloride, bromide or acetate salts, to an aqueous medium to produce an aqueous solution and reacting the above solution with a chemical agent which will yield by precipitation (nucleation) either a reduced metal, compound or an alloy of said metal. The precipitation reaction is generally carried forth in the presence of at least one colloid stabilizer thereby stabilizing the resulting colloid formed and insuring good dispersion for the medium.
Although there are various methods for the production of colloids, e.g., U.S. Pat. No. 2,438,230, such approaches, while simple to implement, do not provide as great a freedom with respect to selectivity of colloids formed and their properties as those produced by the precipitation technique. U.S. Pat. No. 3,635,668 describes a process for the production of copper hydrate suitable for use as a fungicide. U.S. Pat. No. 3,082,103 demonstrates a universal milling technique by which finely divided oxides may be formed. It should also be noted that while most of the examples in the present invention are directed to formation of the colloidal solutions via precipitation techniques, the present invention is not limited to this approach. Specifically, catalytic colloidal composition may also be prepared by the dissolution and stabilization of properly prepared powders. Hence, the manner by which the chemical components are used in preparing said colloidal catalytic composition is a matter of convenience, e.g., shipping costs. The precipitation technique for producing the catalytic medium is believed however to possess certain advantages. Specifically, this technique is potentially capable of producing colloids of varied size, shape, and chemical make-up. This freedom is especially useful with respect to desired subsequent catalytic properties. Furthermore, such technique is also useful in the preparation of reduced metal or metal-alloys or compounds by adding a suitable precipitating agent (e.g., reducing agent), which can form the reduced metallic state or the alloys or the resulting compound(s) through its chemical interaction with the metal ion(s). Typical reducing agents are tannic acid, hydrazine, amineboranes, hypophosphites, borohydrides, sulfur types, etc. In the event that the colloids are prepared by a precipitation technique it may further be recommended that after preparation, centrifugation, washing and redispersion in pure water be undertaken thereby removing extraneous ionic species and insuring a medium with low ionic strength.
The stability of the above colloidal compositions may be enhanced by various techniques, e.g., dialysis, repetitive centrifugation and washings, as well as by the addition of various materials, referred to herein as stabilizers. The term "stabilizer" as used herein to generally describe chemicals believed to be adsorbed onto the colloids thereby altering the charge characteristics of said colloids and thus preventing their coagulation. Such stabilizers may be of organic or inorganic nature.
Stabilizers contemplated by the present invention include secondary colloids, polyalcohols, sugars, dispersants and surfactants, which while by themselves do not serve to catalyze the dielectric substrate in this process, they are believed to stabilize the active colloid by an encapsulation (or absorption) mechanism. It is noted that for a specific composition more than one stabilizer may be present. Stabilizers may also be chemicals which take part within the colloidal double layer structure.
Typical secondary colloids are gum arabic, gelatine, agar agar, starch, albumin, hemoglobin, cellulose derivatives such as carboxymethyl cellulose and hydroxypropyl cellulose, N-alkylbeta-aminopropionic acid, carboxymethyl dextran, and the like. Typical sugars include mannitol, sorbitol, dulcitol maltose, and arbinose raffinose.
Surfactants may also be suitably employed as a stabilizer for the colloids. The surfactant, or surface active agent, as used herein generally refers to substances which are capable of lowering the surface tension of a liquid or the interfacial tension between two liquids. All such substances possess the common feature of a water-soluble (hydrophillic) group attached to an organic (hydrophobic) chain. Surfactants as used herein are also intended to encompass detergents, dispersant and emulsifying agents regardless of whether they are capable of lowering the interfacial surface tension. The surfactants used are not limited to the hydrocarbon type and they can be fluorocarbon or silicon bearing type.
It is also contemplated that a mixture of surfactants or surfactants with other stabilizers may be used. Care should be exercised (e.g., excess concentration) in the use of surfactants in the preparation of the present colloids, as would be noted by anyone skilled in the art.
The term "precipitation agent" as used herein is generally intended to encompass those chemical compounds which when contacted with metallic ions (with or without added energy) cause the onset (nucleation) of the secondary phase (insoluble phase). Typical materials may be reducing agents, hydroxides, sulphides and others. At times, depending on the chemical nature of the precipitation agents, codeposits within the resulting colloids are noted.
In general, the electroless coating process of the present invention comprises contacting (e.g., by immersion) the dielectric substrate, preferably previously etched with the colloid, i.e., the colloidal catalytic composition, washing the substrate and then contacting the colloid adsorbed substrate with a composition comprising an activating agent, (e.g., reducing agent) to form an activated state (e.g., reduced oxidation state) on the surface of the substrate, thus forming the catalytic nuclei active effective for the electroless build-up process upon subsequent immersion of the substrate in an appropriate electroless plating bath. Alternatively, the second step may be deleted.
Activation may also encompass a selective dissolution of the colloidal stabilizer(s) when present on the substrate.
For the sake of convenience, certain examples hereinafter will not refer to the intermediate rinsing step, but the need for such step should be recognized.
The following examples are illustrative of the present invention and are not to be taken in limitation thereof.
EXAMPLE 1
An ABS substrate was etched in a solution comprised of 400 g/l chromium oxide, 350 g/l concentrated sulfuric acid, and a fluorocarbon surfactant for several minutes at a temperature of 70° C. Thereafter, the etched substrate was immersed in the colloidal dispersions for 5 minutes. Plating evaluation was carried out at room temperature using a typical commercial electroless copper bath. The colloidal compositions were as follows:
______________________________________Cu(NO.sub.3).sub.2 0.04MNi(NO.sub.3).sub.2 0.01MNaBH.sub.4 0.019MNaOH 0.19MOrzan S 12 g/lDaxad 11 1.35 g/l______________________________________ Orzan S is predominantly sodium lignosulfonate. Daxad 11 is predominantly sodium salts of polymerized alkylnaphthalene sulfonic acids.
Test 1A: In this case the nickel and copper were admixed as above prior to the colloidal nucleation step.
Test 1B: Same as 1A, however, NaBH 4 and NaOH were reduced by 20% and nickel ions via the inorganic nickel compound was added post the copper colloid post nucleation to yield a 0.01M concentration level. Induction times were found to be 20 sec and 10 sec for tests 1A and 1B, respectively. It is also noted that after the colloidal compositions, immersion into a 0.3 g/l dimethylamine borane solution at 49° C. for 3 minutes took place. Furthermore, in preparing the above colloids, nucleation, preferably above room temerature, took place. It is further noted that though the present colloids are derived using coppric ions, copprous ions (Cu(I)) may be substituted and hence their incorporation falls within the spirit of this invention.
It is interesting to note that repeating the procedure of Example 1, however substituting cobalt, copper or iron for the nickel, did not reveal the unusual effect(s) encountered for nickel. It is further noted that though in this example certain specific nickel and copper salts were selected other salts or inorganic compounds of these metals may be substituted in a manner obvious to one skilled in the art. Further investigation of the unexpected results have demonstrated that the concentration of added nickel ions may be varied over a wide range while providing the noted improvement. In addition, examination by electron microscopy using composition similar to 1A and 1B have shown marked differences, specifically the diffraction pattern (plates 7315 and 7317) for 1B showed a greater degree of amorphous nature in comparison to 1A. Also the transmission mode showed 1B to contain an extremely fine grained background.
While I do not wish to be bound by theory it would appear that the addition of nickel post the copper colloid nucleation is placed around the copper colloid and thereby the resulting adduct has a greater catalytic activity.
It should also be obvious that various approaches may be taken in the charging of such colloids, e.g., controlled addition of compound with specific anions such as hydroxyl ions and/or controlled addition of suitable surfactants and/or secondary colloids. In addition, the reference to catalytic metal in this invention is intended to encompass various colloidal end-products (e.g., metals, alloys, oxides, compounds, and mixtures thereof) bearing the catalytic metal(s) in any of several oxidation states which are non-noble. The catalytic composition may be the colloidal product as prepared or the colloidal product derived after further cleaning of the colloid has been made to remove extraneous (undesired) chemical species.
It will further be obvious to one skilled in the pertinent art that many modifications and variations may be made in the preceding description without departing from the spirit and scope of the present invention. For example, it will be apparent that mixtures of reducing agents may be used in a single solution or may be used in succesive steps. Furthermore, it is within the scope of the present invention to delete the use of a separate reducing solution and directly immerse the substrate (contacted previously with the colloidal catalytic composition) in an electroless plating formulation containing one or more reducing agents.
It should also be recognized by those skilled in the art that, from the present teachings, multiple combinations of materials shown in separate examples are possible and such combinations fall within the spirit of the invention. It is understood that the term copper colloid encompasses colloids whose nucleus is of either elemental copper, compounds of copper or alloy of copper and mixtures thereof. | Metallic surfaces are imparted to non-conductive or dielectric substrates by an electroless (chemical) coating process comprised of coating the surface of the substrate with colloids of catalytic non-precious metals wherein the metals are either part of an alloy or in the elemental state or a compound and wherein the colloidal compositions are prepared by a special method which renders the colloids a greater catalytic activity when used in the plating process. | 8 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to the field of space frame structures, and in particular to frameworks of struts utilizing octahedron and tetrahedron geometry and components for realizing such structures.
2. Prior Art
Space frame systems involving assemblages of octahedrons and tetrahedrons have been known for many years. Such a system was described, for example, in U.S. Pat. No. 2,986,241 issued in 1961 to R. Buckminster Fuller. Dr. Fuller coined the term "octet" to describe structures which involve octahedron/tetrahedron geometry. As envisioned by Dr. Fuller, a space frame or truss having octet geometry can be made up of modular struts coupled together a their ends. Dr. Fuller disclosed that such structures have extremely favorable strength to weight ratios.
The present invention improves on the octet space frame invented by Dr. Fuller in that it allows even better strength to weight ratios to be attained. An additional feature of the present invention is the substantially simpler assembly effort required.
SUMMARY OF THE INVENTION
The basic building block of an octet structure includes both octahedron and tetrahedron shapes. These building blocks are assembled from uniform sized struts, an octahedron requiring twelve struts and a tetrahedron six. The struts form the edges of the building blocks and, in a completed truss, each single strut is a part of several adjacent building blocks. That is, a single strut in the interior of a truss, for example, at one time forms an edge of two adjacent octahedrons and two adjacent tetrahedrons. The ends of the struts are tied together by connectors, which as will be described in detail below, may be constructed to allow easy assembly of the structure.
One octahedron and two tetrahedrons assemble to form the fundamental "octet" unit. The replication of the fundamental octet unit in one direction results in an "octet mast" , which can be of any desired length, depending on the number of fundamental units assembled. Replication of octet units in two or three directions results in an "octet truss". In other words, linear replication results in a pole, replication in two directions results in a sheet (having the thickness of an octet unit), and replication in three directions results in a volume.
As disclosed by Dr. Fuller, an octet truss space frame is suitable for constructing relatively large structures having very favorable strength to weight ratios. The present invention improves on the octet truss as described by Dr. Fuller by fabricating octet truss structures using struts which, instead of being simple tubular struts, are octet masts comprised of smaller tubular struts. This type of construction provides even more favorable strength to weight ratios than disclosed by Dr. Fuller and makes possible much larger structures. Using the principles of the present invention, it is possible to construct structures having higher yet strength to weight ratios. This is accomplished by using a second expansion octet mast as a strut. That is, the struts which form the final space frame are octet masts whose struts, in turn, are also octet masts. A second expansion strut is not the limit. As many iterations as necessary to achieve the desired structure are possible. Since the ratio of strength to weight improves with each iteration, it can be seen that the principles of the present invention will allow extremely large structures with extremely favorable strength to weight ratios to be fabricated.
The struts which form the octahedron and tetrahedron shapes of the present invention must be securely joined at their ends so that structural integrity can be maintained. In any practical structure, the number of such joints is so large that the design of the joint from the point of view of ease of assembly is very important. In the case of structures to be built in outer space, assembly without tools, and possibly by robots, are also important considerations. It is also desirable that individual struts in a truss be removable and replaceable without having to disturb adjacent struts. In one of its aspects, the present invention involves a novel connector piece for joining the ends of the struts which allows simple, rapid, and secure assembly and also allows individual struts to be removed or replaced easily. The invented connector piece also results in an aesthetically pleasing structure.
In one embodiment shown, the assembly is accomplished by merely sliding the strut laterally along a face of the connector piece until the strut snaps into place. The assembly requires no tools or separate fasteners. The connector piece has an overall shape which can be viewed as two interpenetrating or as eight tetrahedrons covering the faces of an octahedron. It can be either solid or hollow, as desired. The strut ends fit between adjacent faces of the connector piece and may be retained in various possible ways as will be described in detail below.
A more detailed explanation of the invention in its various aspects can be had by reference to the following detailed description and the appended drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1A is a perspective view of a first preferred embodiment of a strut used in connection with octet geometry space frames, shown without fastening means, for clarity.
FIG. 1B is a cross sectional view taken at 1B--1B of FIG. 1A.
FIG. 2 is a perspective view of a first preferred connector piece used to join the struts which form octet geometry space frames, shown without fastening means, for clarity. FIGS. 2A and 2B depict two tetrahedrons which are combined in FIG. 2C to show the completed connector piece.
FIGS. 3A and 3B are an end view and side view respectively of one end of a strut similar to that shown in FIG. 1, but showing a first preferred retaining mean,
FIG. 3C is a partial cross sectional view of the strut of FIG. 3A taken in the direction 3C--3C of FIG. 3A.
FIG. 4A is a head on view of two adjacent faces of a connector piece similar to that shown in FIG. 2, but with retaining means for use with the strut of FIG. 3.
FIG. 4B is a partial cross section view of the connector piece of FIG. 4A taken in the direction 4B--4B 4B of FIG. 4A,
FIG. 4C is a partial cross section view of the connector piece of FIG. 4A taken in the direction 4C--4C 4C of FIG. 4A.
FIGS. 5A and 5B are a side and end view of an end of the strut of FIG. 3, showing a locking mechanism. Both FIGS. 5A and 5B are partially sectioned, the sectioned portions being at planes 5A--5A and 5B--5B.
FIG. 6 is an exploded view of an octet mast.
FIG. 7 is a plan view of a small section of an octet truss made according to the principles of the present invention.
FIG. 8 is an exploded view of the joint between two octet masts.
FIG. 9A is a head on view of two adjacent faces of a connector piece with a second embodiment retaining means.
FIG. 9B is a partial cross sectional view of the connector piece of FIG. 9A taken on 9B--9B of FIG. 9A.
FIG. 10A and 10B are end and side views respectively of one end of a strut showing a second embodiment retaining means.
FIG. 11 is another embodiment of a connector piece for use with the strut of FIG. 10.
FIG. 12 is a cross sectional view of the connector piece of FIG. 10, taken at 12--12 of FIG. 11.
DESCRIPTION OF THE INVENTION
The present invention involves fastening large numbers of struts at their ends in such sequence as to form space frames comprised of "octet" structures. In one of its aspects, the present invention is concerned with a simple and convenient connection means for joining the ends of the struts to achieve the desired octet form. FIGS. 1 and 2 show first preferred embodiments of a basic strut and a connector piece which can be used in connection with the improved space frames disclosed in this specification or with prior art octet space frames. For purposes of clarity, and as an aid to understanding, FIGS. 1 and 2 depict the basic strut and connector piece without showing retaining or locking means. Such means are described later.
The basic strut, generally indicated by the numeral 10 in FIG. 1, is comprised of a body portion 11 and two identical ends 12. The body portion 11 is preferably tubular and can conveniently have a cross sectional shape the same as that of an octet mast, i.e., a diamond shape, or can have any other desired cross sectional shape, e.g. circular or square. A diamond cross sectional shape may be preferred if robotic assembly is contemplated, since the diamond shape provides a directional reference at all times. The diamond shape also presents a pleasing appearance, especially when used in connection with the interpenetrating tetrahedron connector piece disclosed herein. Additionally, the diamond shape can in some cases provide additional stability. When the diamond shape is used, it is preferred that the body include a cross web, such as web 17, which increases the compressional strength of the body.
The strut ends 12 are secured to the body portion as by welding 16. The chisel shape on the end of the i.e., surfaces 13 and 14, is configured as two adjacent faces of an octahedron for purposes of mating with corresponding faces on the connector piece.
Connector piece 20, shown in FIG. 2C has 12 pairs of surfaces for mating with surfaces 13 and 14, e.g. surfaces 23 and 24. The connector piece can be a solid block, but for purposes of reducing the weight of the space frame it may be preferred to make it hollow. Connector piece 20 can be visualized as being comprised of two interpenetrating tetradedrons. FIGS. 2A and 2B show two tetrahedrons 20A and 20B which, when combined, make up the connector piece 20 in FIG. 2C. If faces 13 and 14 of one strut 10 are abutted to faces 23 and 24 of the connector piece 20, and the faces 13 and 14 of another strut 10 are abutted to faces 25 and 26, it will be seen that the two struts will be at right angles to each other. A third strut abutted to faces 27 and 28 will make an angle of 45° to the plane of the struts previously described, and a 60° angle with each strut. Similar relationships exist between the other pairs of faces of connector piece 20. Thus, it will be realized that connector piece 20 can serve to orient struts at any of the angles needed to form both the octahedrons and tetrahedrons as assembled in the octet form.
Strut 30, one end of which is shown in FIG. 3, is similar to the strut of FIG. 1, except that it is fitted with a first preferred means for retaining the strut in place on a connector piece. FIG. 3 shows the retaining means, but for clarity does not show means for tightening the joint. Such means are discussed later. The mating connector piece is shown in FIG. 4. FIG. 4A is a face on view of two adjacent faces of a connector piece similar to connector piece 20 except that the connector piece 40 is fitted with retaining means to retain struts such as strut 30. The strut retaining means shown in FIGS. 3 and 4 involves mating tongues and slots, but it will be understood by those skilled in the art that other types of interlocking slide means (such as a dovetail slide) could be used in their place. The unique characteristic which is disclosed, is an interlocking slide assembled using a motion 90° to the length of the strut, i.e., a lateral motion.
Strut 30 has a body 31 and two identical ends, only one of which (32) is shown. The end 32 has two faces 33 and 34 which are intended to mate with two adjacent faces of connector piece 40, e.g. faces 43 and 44. A lateral slot 35, adapted to mate with a corresponding tongue 45 on a face of connector piece 40 is set into each of the faces 33 and 34.
To assemble a strut 30 with the connector piece, an end is slid laterally across two corresponding faces of the connector piece with a pair of tongues 45 on the connector piece sliding in corresponding slots 35. The flat 36 on the end of end 32 contains two grooves 37 which mate with snap catches 46 of connector piece 40 to retain strut 30. Snap catches 46 are spring loaded by springs 47 so that when the strut is in its assembled location, the spring catches 46 straddle the land 38 between grooves 37. Retainer 48 positions and retains spring catches 46. The use of two spring catches 46 allows a strut to be inserted from either side of the connector. If one of the spring catches as shown in FIG. 4 were to be replaced with a fixed stop, toolless assembly can still be accomplished, but it can only be accomplished from the side of the remaining spring catch.
While the struts and connectors which have been described above will allow an octet mast or octet truss to be constructed, because of the clearances and tolerances necessary to permit assembly, there will inevitably be a certain amount of play or looseness in the connections, and thus some lack of tightness in the completed mast or truss. It is therefore preferable that the joints be tightened or locked into position. FIG. 5 (A and B) shows a first preferred means for tightening the joint between struts, such as strut 30', and connector pieces, such as connector piece 40. The strut end 32' shown in FIG. 5 is similar to strut end 32 except for the inclusion of joint tightening means. A pair of clamp pieces 51 ride in a slot milled or otherwise formed in end 32'. The clamp pieces 51 are cut away as shown so as to be somewhat compressible. They ride against shaft 52 which has two flats in the area contacting clamp pieces 51. Thus if shaft 51 is rotated 90° from the position illustrated, the clamp pieces 51 will move slightly into slots 35'. If the strut end 32' were assembled to a connector piece such as connector piece 40 with tongues 45 in slots 35', the motion of clamp pieces 5 would cause the connector piece to press tightly against end 32'. The compressibility of the clamp pieces assures that adequate clamping force will be applied, even though the dimensions of the parts may vary because of dimensional tolerances. Clamp pieces 51 are retained in the slot in end 32' by retainer 53. Lever 54 is fastened to the end of shaft 52 opposite the flats and is used to lock and unlock strut end 32' from a connector piece, the position shown dotted in FIG. 5A being the locked position while the solid position (corresponding to the drawn position of shaft 52) is the unlocked position. When lever 54 is in its solid drawn position, the end 32' can be slid into engagement with one of the pairs of faces of connector 40, and when engaged, can be locked by moving lever 54 to the dotted position.
An octet mast or truss can be assembled from struts and connector pieces by assembling them in the proper sequence until the desired structure results. No tools of any kind are required for assembly. The parts are assembled and locked manually, i.e., without the necessity of using tools of any sort. Because of the simplicity and regularity of the assembly process, it will be realized that it can be automated and done by robot if desired. A strut can easily be removed from a connector piece, even though the truss is completely assembled. It is only necessary to unlock any tightening mechanism, insert a blade to retract a spring catch 46 and slide the strut out of engagement with the connector piece.
Under some conditions, e.g., in outer space, the transmission of shock and vibration in a space frame can be a problem. To reduce such transmission, the mating surfaces between the struts and the connector pieces may be coated with vibration absorbing material.
The basic struts and connector pieces as described above can be assembled into octet truss space frame structures as described in Dr. Fuller's '241 patent mentioned above for example, or in accordance with a second aspect of the present invention, they can be assembled into an octet mast configuration which in turn is used as a strut of a larger octet truss space frame.
An octet mast is an elongated framework structure made up of interconnected struts characterized by a repeating sequence of octahedron and tetrahedron shapes. FIG. 6 is an exploded view of a section of an octet mast showing that the basic building block of the mast 60 consists of an octahedron 61 and two tetrahedrons 62 and 63. When assembled, the octahedron 61 and the two tetrahedrons 62 and 63 form an octet unit 64. Replicating the basic building blocks results in an octet mast. A mast of any desired length can be fabricated by repeating the sequence of one octahedron and two tetrahedrons until the desired length is attained. As discussed herein, an octet truss using octet masts as strut elements can provide very large and efficient structures. FIG. 7 is a plan view of a small section of an octet truss space frame made up of struts which are octet masts. Some details of the octet mast construction are not shown, for clarity.
The truss section 70 as shown in FIG. 7 is a part of a flat panel. It should be understood that the near and/or far surfaces of the panel can be filled in, to whatever extent desired with octet units to provide surfaces having smaller openings. That is, for example, if the truss of FIG. 7 was intended to be used as the framework for a floor of a marine platform, and the span between the octet mast/struts making up the top plane of the floor (e.g. octet mast/struts 71, 72, and 73) was too great to support the flooring to be used, the space between these members could be filled in to whatever degree is necessary using octet mast sections.
As noted above, a second (or greater) expansion of the octet mast/strut is considered to be within the scope of the present invention. That is, in the second expansion truss, the struts as shown in FIG. 71, e.g. struts 74 and 75, instead of being tubular struts, as in the first expansion truss, are octet masts, resulting in a lower weight for a given strength.
FIG. 8 is an exploded view of a typical joint between two octet mast/struts, identified by the numerals 81 and 82, illustrating the fact that no special means are required to make the connections between octet mast/struts. The joining of two octet mast/struts is accomplished automatically due to the fact the intersection includes struts which are common to both octet masts. The struts which are common to octet masts 81 and 82 can be seen to be the struts which form octahedron 83 and tetrahedron 84. As an aid in visualizing the interconnection, struts which appear in the exploded view of FIG. 8 more than once are shown solid at one appearance only, and dotted at all other appearances. For example, strut 85 appears in FIG. 8 four times; it is shown solid on octahedron 83 and dotted at each other appearance.
While FIG. 8 is illustrative of how connections are made between octet mast/struts, it is in fact somewhat simplified in that in actual structures each joint involves joining 6 to 12 octet mast/struts rather than just 2, as shown. FIG. 8, nevertheless, illustrates the principle involved.
A second embodiment of a connector piece with a second means of joining struts is shown in FIG. 9, and an end of an accompanying strut is shown in FIG. 10. The connector piece 90 of FIG. 9 is similar to the connector pieces 20 and 40 except for the strut retaining means. Faces 93 and 94 correspond to the faces 23 and 24, for example, of connector piece 20. Lug 95, which is set central in the space between faces 93 and 94 contains a tapped hole 96 with counterbores 97 on each side.
Strut 100 has an end 102 including an offset web 105. Bolt 106, with retaining "C" ring 107, is positioned on web 105 so that it will mate with the tapped hole 96 when surfaces 103 and 104 of end 100 abut surfaces 93 and 94. Web 105 is offset enough so
that when face 105A is assembled against lug 95, strut 100 will center over faces 93 and 94. "C" ring 107 nests in one of counterbores 97.
FIGS. 11 and 12 show another embodiment of a connector piece for use with the strut of FIG. 10. the connector piece as illustrated in FIGS. 11 and 12 consists of twelve tabs 111-122 radiating from a central region, each tab positioned to orient and retain one strut. Only tabs 111-121 are visible in the figures, 122 being hidden behind tab 119 in FIG. 11. The tabs as shown are secured to one another by welding 123. Each of the tabs has a tapped hole 124 to receive a bolt 106 of a strut 100, and two counterbores 125 to clear "C" ring 107.
As can be seen from the figures, the tabs 111-114, 115-118, and 119-122 will orient struts to lie in three mutually perpendicular planes, with each strut making a 45° angle with respect to each of the two planes it intersects. This geometry results in each strut making a 60° angle with each of its four neighboring struts. The orientation as described is the same strut orientation as achieved by the previously described connector pieces, and is that needed to obtain the octet structures desired
Each of the strut ends 102 includes a "U" shaped slot comprised of bottom face 105A of web 105, and side faces 108 and 109. This slot can be used to orient the strut when used in conjunction with the connector piece illustrated in FIGS. 11 and 12. The mating surfaces of, e.g., tab 115 would be surfaces 126 and 127, and one of surfaces 128 and 129, depending on which direction the strut is assembled. Bolt 106, threaded into tapped hole 124 will provide the mechanical connection between the strut and the tab.
What has been described is a novel octet based space frame system, and components which are useful in assembling such a space frame The components disclosed can also be used in connection with prior art octet space frames. Various adaptations and modifications within the spirit of the claims hereto will no doubt occur to those skilled in the art. Such adaptations and modifications are intended to be covered by the following claims. | A space frame constructed from a plurality of identical struts using octahedron/tetrahedron ("octet") geometry wherein the struts, instead of being simple tubular members, are fabricated as space frame masts using octet geometry. A second aspect of the invention concerns a connector piece for orienting and joining the ends of struts to form octet structures. In one embodiment, the connector piece is in the shape of two interpenetrating tetrahedrons, allowing assembly and disassembly of individual struts without disturbing other struts. Retaining means are described which do not require tools for assembly. | 4 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The invention relates to a device for filling the depressions in a cylinder of a printing machine (e.g., a screen roller) with a fluid. The invention also relates to a doctor blade device especially suited for this purpose, as well as to a process for changing the doctor blade device.
2. Discussion of the Prior Art
It is becoming increasingly important for printing machines to have, along with flexibility in web guidance, the capacity to change ink colors rapidly between printing jobs. Four-color printing machines, for example, must frequently be converted from a four-color printing mode with one web to a one-color printing mode with four webs. To minimize down time, such conversions must be carried out as quickly as possible. Conversion time is especially costly when printing machines are used for small runs e.g., when there are frequent changes in the type of production. Such printing machines include those connected to data networks for the decentralized printing of small runs. Printing machines of this type are described, for example, in German Patent Application DE 196 24 395.5. One time-consuming task in converting a printing machine is cleaning the inking unit.
German reference DE 39 11 839 A1 discloses what is known as a "rinse inking unit" for inking a screen roller. In this device, an inking channel is arranged below the screen roller. On both sides of the inking channel, doctor blades rest on the screen roller. Changing the ink in this device would require a time-consuming process of cleaning and exchange.
SUMMARY OF THE INVENTION
It is an object of the present invention is to provide a device for filling the depressions in a cylinder of a printing machine with a fluid, which device permits a quick change to a different fluid. A further object of the invention is to provide a doctor blade device for filling the depressions that is especially suitable for this purpose. Yet another object is to provide a process for changing the doctor blade device.
Pursuant to these objects, and others which will become apparent hereafter, one aspect of the present invention resides in a device for filling depressions of a cylinder of a printing machine with a fluid, which device includes at least two doctor blade devices configured to be selectively and individually movable into effective connection with the cylinder. In another embodiment of the invention one of the doctor blade devices is configured for filling a solidifiable fluid and another of the doctor blade devices is configured for filling ink into the depressions of the cylinder.
Another aspect of the invention resides in a doctor blade device for filling the depressions, which doctor blade device includes ink application means, a conveyance system for conveying fluid to the application means, a working blade arranged after the application means in a rotational direction of the cylinder, and means for moving the application means away from the cylinder independently of the working blade so that fluid can flow out of the application means when the application means is in a position away from the cylinder.
In another embodiment of the invention the application means includes a first doctor blade positioned positively and laterally on the cylinder so as to form a wedge-shaped first region that holds the fluid. The wedge-shaped first region is bordered by the doctor blade and a cylindrical surface of the cylinder.
A further embodiment of the invention provides a second doctor blade mounted in front of the first doctor blade in the rotational direction of the cylinder so as to define a second region. The second doctor blade has bores distributed along its length so as to place the second region and the first region in fluid communication.
In another embodiment of the invention the first region is operated at a slight overpressure of the fluid. Overflow ducts are in fluid communication with the second region and a collection basin so that the fluid can flow into the collection basin.
Still another embodiment of the invention provides two sealing plates. Each of the sealing plates is movably arranged to rest against a respective end face of the first doctor blade. Spring means are provided for pressing the sealing plates toward the respective end face. Bolts are arranged so that the sealing plates rest against the bolts and the first doctor blade with a 3-point support.
A further embodiment of the invention includes two working cylinders operatively connected to respective ones of the sealing plates so that the sealing plates can be moved toward and away from the cylinder. Flat surface members are arranged to guide the sealing plates with play during positioning movement toward the cylinder so as to permit centering of the sealing plates on the surface curvature of the cylinder.
In yet another embodiment of the invention the application means is configured to be moveable in a longitudinal direction of the cylinder out of the cylinder surface region of the cylinder.
Still another embodiment of the invention provides a first holder and a second holder arranged to hold respective sides of the application means and the working blade. A side wall is provided having a support member mounted thereto and a support tube mounted to the side wall and the support member. A spindle is mounted movably in the support tube. The first holder is movably arranged on the support tube and the second holder is attached to the spindle.
Still yet another embodiment of the invention provides means for oscillating the device. The oscillating means includes a working cylinder that rests on the support member and has a piston rod connected detachably to the second holder.
By moving one doctor blade device out of position (i.e., away from the cylinder) and another doctor blade device into position on the cylinder, it is possible to change rapidly to a different filling fluid. When this is done, no intervening cleaning step is needed. Furthermore, a specially proposed doctor blade device is automatically emptied when moved out of position, making cleaning unnecessary. In addition, the working blade that remains on the cylinder after the application mechanism of the doctor blade device has been moved away cleans the cylinder. This doctor blade device is well-suited for imaging a printing form of a printing machine for the "computer-to-press" method; for example, using the gravure printing/UV ink process described in German reference DE 196 24 441.2.
The various features of novelty which characterize the invention are pointed out with particularity in the claims annexed to and forming a part of the disclosure. For a better understanding of the invention, its operating advantages, and specific objects attained by its use, reference should be had to the drawing and descriptive matter in which there are illustrated and described preferred embodiments of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 shows a doctor blade device pursuant to the present invention, in partial section;
FIG. 2 is a top view in Direction II as in FIG. 1;
FIG. 3 is a view in Direction III as in FIG. 1;
FIG. 4 is a section along line IV--IV in FIG. 1;
FIG. 5 is an enlarged section from FIG. 1;
FIG. 6 shows the elements of FIG. 5 in the a position removed from the cylinder;
FIG. 7 shows a double printing group with doctor blade devices; and
FIG. 8 shows the ink supply system for the doctor blade devices in FIG. 7.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
The doctor blade device shown in FIG. 1 is attached to the side wall 4 of a printing machine by a support 3. The doctor blade device contains an application mechanism 129, which has a first doctor blade 6 and a second doctor blade 5, as well as a working blade 27. The doctor blades 5, 6 are positioned positively on the cylinder to be inked (here, a form cylinder 8). This means that the doctor blades 5, 6 point in the rotational direction 7 of the form cylinder 8. The doctor blades 5, 6 are arranged laterally on the form cylinder 8. The blades 5, 6 are attached to a carrier 9, which is mounted by guides 10, 11 in a support 12. The carrier 9 can be moved by means of a working cylinder 13 in the direction of the arrows 14, 15, i.e., toward and away from the form cylinder 8. The support 12, in turn, is attached to a carrier 16, which is supported by holders 17, 18 on a support tube 19. One end of the support tube 19 is attached to the side wall 4, while the other end is supported by a holder 20 on the support 3 (FIG. 4). At its front side, the carrier 16 is attached by the holder 18 to a spindle 21, which is mounted by guides 22, 23 in the support tube 19. As a result, the spindle 21 can be withdrawn from the support tube 19 telescopically, so that the holder 18 can be moved into the position 18' shown by the dashed-dotted line (FIG. 4). Similarly, the holder 17 then slides on the support tube 19 into the position 17'. In this way, the entire doctor blade device can be moved parallel to the form cylinder 8, so as to achieve a servicing position in front of the latter. In this servicing position, worn parts, e.g., the doctor blades 5, 6, can be easily exchanged. Before the doctor blade device is moved, the grip 24, which connects a working cylinder 25 to the holder 18, must be detached. The working cylinder 25 is supported by a holder 26 on the support 3 and is used, in a known manner, for the purpose of oscillation, i.e., to move the doctor blade device back and forth axially by a certain stroke.
The working blade 27 is positioned negatively on the form cylinder 8 (i.e., opposite to its rotational direction 7) below the doctor blade 6 and at a slight distance from it (FIG. 5). The working blade 27 is attached to a carrier 28, which can be moved in guides 29, 30 by means of working cylinders 33, 34 via levers 31, 32 in the direction of the arrows 35 and 36. The working cylinders 33, 34 are attached to the support 12 by holders 37, 38, while the levers 31, 32 are rotatably attached by bolts 39, 40 and holders 41, 42 to the holders 17, 18.
The doctor blade 6 forms, with the cylindrical surface of the cylinder 8, a first wedge-shaped region 61. The doctor blade 5 forms, with the cylindrical surface of the cylinder 8, a second wedge-shaped region 45, which is open at the top. The two regions 45, 61, are bordered longitudinally by the respective sealing plates 43, 44, which rest on the faces of the doctor blade 6. The two sealing plates 43, 44 also rest on the bolts 48, 49, achieving a three-point support, and are pressed by spring-loaded bolts 46, 47 against the end faces of the doctor blade 6 and the bolts 48, 49. The sealing plates 43, 44 can be moved in the directions 14, 15 by working cylinders 50, 51 (FIG. 2) via drivers 52, 53. For easy removal of the sealing plates 43, 44, the bolts 46, 47 can be moved via levers 54, 55 in the directions 56, 57 counter to the spring forces.
The function of the doctor blade device is described below in reference to FIGS. 5 and 6. The printing ink for inking the cups of a gravure printing form that is carried by the form cylinder 8 is supplied under pressure through a tube 58 and forced through the duct 59 and the duct 60 into the first region 61 between the doctor blades 5, 6. The printing ink then passes through bores 62, which are distributed along the length of the doctor blade 5, into the second region 45, and fills it. Overflow ducts 63, 64 prevent the ink from overflowing the sealing plates 43, 44 (FIG. 3). The fill level of the ink can be detected by a sensor 65 and reported to an ink supply control device, which is explained below.
When the form cylinder 8 is rotated in the direction 7, the cups of the form cylinder 8 are filled with ink in the known manner in the region 45, as FIG. 5 shows. Enclosed air bubbles are extracted from the cups by means of the cavitation that occurs on the doctor blade 5, so that the cups can be completely filled by means of the slight overpressure in the region 61 (depending on the viscosity of the ink up to approximately 2 bar) and the hydrodynamic effect of the doctor blade 6. The cylinder surface is then wiped clean by a working blade 27, which is supported by a rod 66, which in turn is attached to support fingers 67 of the support 12. The wiped-off ink is then able to flow between the support fingers 67 and through bores 68 in the carrier 28 into a collection basin 69. Here, a conveyor screw 71 driven by a motor 70 ensures that the ink is transported back through a hose 72 to an ink supply unit. During this inking procedure, as described above, the doctor blades 5, 6 are pressed in the direction 15 toward the surface of the form cylinder 8 by the working cylinder 13 via the carrier 9, while the working blade 27 is pressed in the direction 35 toward the cylinder surface by the working cylinders 33, 34 via the levers 31, 32 and the carrier 28. At their ends, the levers 31, 32 have balls 73, 127 which are carried along in the respective cylindrical bores 74, 128 in the carrier 28. As a result, the carrier 28 can be pivoted around the ball midpoints, and thus can always optionally position the doctor blade 6 onto the cylinder surface. Disks 75, 76 attached to the carrier 28 prevent ink from flowing into the region of the guides 29, 30.
FIG. 5 also shows that the sealing plates 43, 44, when pressed in the direction 15 toward the cylinder surface by the working cylinders 50, 51 via the drivers 52, 53 and the driver pins 77, 78, are supported on surfaces 79, 80. Because these surfaces 79, 80 are located near the cylinder surface and because the driver pins 77, 78 simultaneously engage, with play, in bores 81 in the sealing plates 43, 44, it is possible for the sealing plates 43, 44 to be centered on the surface curvature of the form cylinder 8 by a slight tilting movement under pressure of the working cylinder 50, 51. This centering option is advantageous when the position of the form cylinder 8 changes, e.g., to compensate for various thicknesses of the printing stock.
FIG. 6 shows the doctor blade device in a position away from the form cylinder 8. After the ink supply is stopped, the doctor blades 5, 6 are moved away from the cylinder surface in the direction 14 by means of the working cylinder 13 and then assume the positions 5', 6'. In addition, the sealing plates 43, 44 are moved away from the surface of the form cylinder 8 by means of the working cylinders 50, 51 and assume the positions 43', 44'. The ink is now able to flow out of the spaces 45, 61 and be captured in the collection basin 69. The working blade 27 remains on the form cylinder 8 in the position shown in FIG. 5 until the ink flows out of the spaces 45, 61 and the surface of the form cylinder 8, after several rotations of the cylinder, is wiped clean. Then the working blade 27 is withdrawn in the direction 36 into the position 27' shown in FIG. 6. A cleanly wiped cylinder surface is then available for subsequent work procedures, such as imaging or cleaning.
The doctor blade device can also be arranged more or less underneath the form cylinder 8. In this case, however, any second space 45 must be embodied with a longitudinal wall. Furthermore, measures must be taken to ensure that when the doctor blade device is moved out of position, the spaces 45, 61 empty. This can be done, for example, by opening the ink line.
FIG. 7 shows a side view of a double printing group with doctor blade devices. A web 82 to be printed is run via rollers 83, 84 between transfer cylinders 85, 86 positioned against one another. The transfer cylinders 85, 86 take the printing image from the form cylinders 88, 89 and transfer the image to both sides of the web 82 running in the direction 87. This drawing shows a UV/computer-to-press method of indirect gravure printing, as described in German reference DE 196 24 441.2. Each of the form cylinders 88, 89 has associated with it two doctor blade devices 90, 91 or 92, 93, whose structures correspond to the doctor blade device described above. In each case, the two doctor blade devices 90, 91 or 92, 93 are supported with one support 94, 95 in a float mounting. In the illustrated embodiment, the cups of the form cylinders 88, 89 are filled with black ink by the doctor blade devices 91, 93, using the UV driers 96, 97, by several cylinder rotations. After this, the doctor blade devices 91, 93 are moved away and the form cylinders 88, 89 are imaged with the help of laser heads 98, 99. If printing is to be carried out with black ink, the doctor blade devices 91, 93 filled with black ink are then moved back into position for the printing process. If colored ink is to be used, the doctor blade devices 90, 92 filled with colored ink are moved into position. In this way, it is possible to quickly implement ink changes, even those required when the web guidance is changed for the purpose of producing different printed products, e.g., small runs.
The described doctor blade devices can also be used when the depressions in a cylinder are to be filled with a different fluid; for example, when a printing form is to be produced on a form cylinder not with UV solidifiable ink, but with a filler substance solidified in a different manner. For instance, on the form cylinder 88, in addition to the doctor blade devices 90, 91 for printing with colored or black ink (not shown), it is also possible to provide a doctor blade device for applying a special filler substance for form production. The doctor blade devices can also be used for conventional gravure printing, for gravure printing with water-based ink, for inking screen rollers per se, e.g., anilox rollers, and for other purposes. Of course, the invention also encompasses equivalents of the embodied examples. For instance, instead of the working cylinders 13, 33, 34, 50, 51, which can be driven hydraulically or pneumatically, it is possible to use electrical lifting magnets, as applicable, in conjunction with return springs. The application mechanism 129 can also function with only one doctor blade, for example, or with a chamber blade or a nozzle application system.
FIG. 8 shows a controlled ink supply for the doctor blade devices 90-93 of a double printing group. The doctor blade devices 91, 93 are for black ink and the doctor blade devices 90, 92 are for colored ink. The processes are controlled by a computer 100. The entire ink supply is based on careful ink treatment, i.e., the ink is to be subjected to as little mechanical stress as possible, for instance, by constant recirculation. When sensors 101, 102 report a need for black ink, valves 103, 104 are opened by the computer 100 and an ink pump 105 is turned on. The pump 105 forces ink through lines 106, 107 into the doctor blade devices 91, 93. When the sensors 101, 102 report an adequate fill level, the pump 105 is turned off and the valves 103, 104 are closed. As described, the returning ink is fed via conveyor screws 108, 109 and lines 110, 111 into the ink container 112. For ink mixing, a stirring unit 113 can be switched on as desired.
The system for colored ink is constructed similarly. After a message from sensors 114, 115, valves 116, 117 are opened and an ink pump 118 is turned on in response to signals from the computer 100. Ink is supplied to the doctor blade devices 90, 92 through lines 119, 120. When a suitable fill level is reached, the ink pump 118 is turned off and the valves 117, 116 are closed. The wiped-off ink is returned via conveyor screws 121, 122 and lines 123, 124 to the ink tank 125, where it is mixed, as desired, by means of the stirring unit 126.
The invention is not limited by the embodiments described above which are presented as examples only but can be modified in various ways within the scope of protection defined by the appended patent claims. | A device for filling depressions in a cylinder of a printing machine with a fluid, e.g., an ink, which permits a quick change to a different fluid, includes at least two doctor blade devices arranged on the cylinder which doctor blade devices can be selectively moved individually into effective connection with the cylinder. | 1 |
FIELD OF THE INVENTION
[0001] The present invention relates to Novel forms of [R—(R*,R*)]-2-(4-fluorophenyl)-β,δ-dihydroxy-5-(1-methylethyl)-3-phenyl-4-[(phenylamino)carbonyl]-1H-pyrrole-1-heptanoic acid magnesium salt designated Form A, Form B, Form C, Form D, Form E, and Form F, characterized by one or more of their X-ray powder diffraction, solid state NMR carbon chemical shift, and solid state NMR fluorine chemical shift. The present invention also relates to pharmaceutical compositions containing such compounds, methods for their preparation and methods for their use in the treatment of hyperlipidemia, hypercholesterolemia, osteoporosis, benign prostatic hyperplasia (BPH) and Alzheimer's disease.
BACKGROUND OF THE INVENTION
[0002] The conversion of 3-hydroxy-3-methylglutaryl-coenzyme A (HMG-CoA) to mevalonate is an early and rate-limiting step in the cholesterol biosynthetic pathway. This step is catalyzed by the enzyme HMG-CoA reductase. Statins inhibit HMG-CoA reductase from catalyzing this conversion. As such, statins are collectively potent lipid lowering agents.
[0000] Atorvastatin calcium, disclosed in U.S. Pat. No. 5,273,995, which is incorporated herein by reference, is currently sold as LIPITOR® having the chemical name [R—(R*,R*)]-2-(4-fluorophenyl)-β,δ-dihydroxy-5-(1-methylethyl)-3-phenyl-4-[(phenylamino)carbonyl]-1H-pyrrole-1-heptanoic acid calcium salt (2:1) trihydrate.
[0003] Atorvastatin calcium is a selective, competitive inhibitor of HMG-CoA reductase. As such, atorvastatin calcium is a potent lipid lowering compound and is thus useful as a hypolipidemic and/or hypocholesterolemic agent.
[0004] A number of patents have issued disclosing atorvastatin, formulations of atorvastatin, as well as processes and key intermediates for preparing atorvastatin.
[0005] These include: U.S. Pat. Nos. 4,681,893; 5,273,995; 5,003,080; 5,097,045; 5,103,024; 5,124,482; 5,149,837; 5,155,251; 5,216,174; 5,245,047; 5,248,793; 5,280,126; 5,397,792; 5,342,952; 5,298,627; 5,446,054; 5,470,981; 5,489,690; 5,489,691; 5,510,488; 5,686,104; 5,998,633; 6,087,511; 6,126,971; 6,433,213; and 6,476,235, which are herein incorporated by reference.
[0006] Additionally, a number of published International Patent Applications and patents have disclosed crystalline forms of atorvastatin, as well as processes for preparing amorphous atorvastatin. These include: U.S. Pat. No. 5,969,156; U.S. Pat. No. 6,121,461; U.S. Pat. No. 6,605,729; WO 00/71116; WO 01/28999; WO 01/36384; WO 01/42209; WO 02/41834; WO 02/43667; WO 02/43732; WO 02/051804; WO 02/057228; WO 02/057229; WO 02/057274; WO 02/059087; WO 02/072073; WO 02/083637; WO 02/083638; WO 03/050085; WO 03/070702; and WO 04/022053.
[0007] Atorvastatin is prepared as its calcium salt, i.e., [R—(R*,R*)]-2-(4-fluorophenyl)-β,δ-dihydroxy-5-(1-methylethyl)-3-phenyl-4-[(phenylamino)-carbonyl]-1H-pyrrole-1-heptanoic acid calcium salt (2:1). The calcium salt is desirable, since it enables atorvastatin to be conveniently formulated in, for example, tablets, capsules, lozenges, powders, and the like for oral administration.
[0008] The process by which atorvastatin calcium is produced needs to be one which is amenable to large-scale production. Additionally, it is desirable that the product should be in a form that is readily filterable and easily dried. Finally, it is economically desirable that the product be stable for extended periods of time without the need for specialized storage conditions.
[0009] Furthermore, it has been disclosed that the amorphous forms in a number of drugs exhibit different dissolution characteristics, and in some cases different bioavailability patterns compared to the crystalline forms (Konno T., Chem. Pharm. Bull., 1990; 38; 2003-2007). For some therapeutic indications, one bioavailability pattern may be favored over another.
[0010] In the course of drug development, it is generally assumed to be important to discover the most stable crystalline form of the drug. This most stable crystalline form is the form which is likely to have the best chemical stability, and thus the longest shelf-life in a formulation. However, it is also advantageous to have multiple forms of a drug, e.g. salts, hydrates, polymorphs, crystalline, and noncrystalline forms. There is no one ideal physical form of a drug because different physical forms provide different advantages. The search for the most stable form and for such other forms is arduous and the outcome is unpredictable.
[0011] The successful development of a drug requires that it meet certain requirements to be a therapeutically effective treatment for patients. These requirements fall into two categories: (1) requirements for successful manufacture of dosage forms, and (2) requirements for successful drug delivery and disposition after the drug formulation has been administered to the patient.
[0012] There are many kinds of drug formulations for administration by various routes, and the optimum drug form for different formulations is likely to be different. As mentioned above, a drug formulation must have sufficient shelf-life to allow successful distribution to patients in need of treatment. In addition, a drug formulation must provide the drug in a form which will dissolve in the patient's gastrointestinal tract when orally dosed. For oral dosing in an immediate release dosage form, such as an immediate release tablet, capsule, suspension, or sachet, it is generally desirable to have a drug salt or drug form which has high solubility, in order to assure complete dissolution of the dose and optimal bioavailability. For some drugs, particularly low solubility drugs or poorly wetting drugs, it may be advantageous to utilize a noncrystalline drug form, which will generally have a higher initial solubility than a crystalline form when administered into the gastrointestinal tract. A noncrystalline form of a drug is frequently less chemically stable than a crystalline form. Thus, it is advantageous to identify noncrystalline drug forms which are sufficiently chemically stable to provide a practical product which is stable enough to maintain its potency for enough time to permit dosage form manufacture, packaging, storage, and distribution to patients around the world.
[0013] On the other hand, there are dosage forms which operate better if the drug form is less soluble. For example, a chewable tablet or a suspension or a sachet dosage form exposes the tongue to the drug directly. For such dosage forms, it is desirable to minimize the solubility of the drug in the mouth, in order to keep a portion of the drug in the solid state, minimizing bad taste. For such dosage forms, it is often desirable to use a low solubility salt or crystalline form.
[0014] For controlled release oral or injectable, e.g, subcutaneous or intramuscular, dosage forms, the desired drug solubility is a complex function of delivery route, dose, dosage form design, and desired duration of release. For a drug which has high solubility, it may be desirable to utilize a lower solubility crystalline salt or polymorph for a controlled release dosage form, to aid in achievement of slow release through slow dissolution. For a drug which has low solubility, it may be necessary to utilize a higher solubility crystalline salt or polymorph, or a noncrystalline form, in order to achieve a sufficient dissolution rate to support the desired drug release rate from the controlled release dosage form.
[0015] In soft gelatin capsule dosage forms (“soft-gels”), the drug is dissolved in a small quantity of a solvent or vehicle such as a triglyceride oil or polyethylene glycol, and encapsulated in a gelatin capsule. An optimal drug form for this dosage form is one which has a high solubility in an appropriate soft-gel vehicle. In general, a drug form which is more soluble in a triglyceride oil will be less soluble in water. Identification of an appropriate drug form for a soft-gel dosage form requires study of various salts, polymorphs, crystalline, and noncrystalline forms.
[0016] Thus, it can be seen that the desired solubility of a drug form depends on the intended use, and not all drug forms are equivalent.
[0017] For a drug form to be practically useful for human or animal therapy, it is desirable that the drug form exhibit minimal hygroscopicity. Dosage forms containing highly hygroscopic drugs require protective packaging, and may exhibit altered dissolution if stored in a humid environment. Thus, it is desirable to identify nonhygroscopic crystalline salts and polymorphs of a drug. If a drug is noncrystalline, or if a noncrystalline form is desired to improve solubility and dissolution rate, then it is desirable to identify a noncrystalline salt or form which has a low hygroscopicity relative to other noncrystalline salts or forms.
[0018] A drug, crystalline or noncrystalline, may exist in an anhydrous form, or as a hydrate or solvate or hydrate/solvate. The hydration state and solvation state of a drug affects its solubility and dissolution behavior.
[0019] The melting point of a drug may vary for different salts, polymorphs, crystalline, and noncrystalline forms. In order to permit manufacture of tablets on commercial tablet presses, it is desirable that the drug melting point be greater than around 60° C., preferably greater than 100° C. to prevent drug melting during tablet manufacture. A preferred drug form in this instance is one that has the highest melting point. In addition, it is desirable to have a high melting point to assure chemical stability of a solid drug in a solid dosage form at high environmental storage temperatures which occur in direct sunlight and in, geographic areas such as near the equator. If a soft-gel dosage form is desired, it is preferred to have a drug form which has a low melting point, to minimize crystallization of the drug in the dosage form. Thus, it can be seen that the desired melting point of a drug form depends on the intended use, and not all drug forms are equivalent.
[0020] When a drug's dose is high, or if a small dosage form is desired, the selection of a salt, hydrate, or solvate affects the potency per unit weight. For example, a drug salt with a higher molecular weight counterion will have a lower drug potency per gram than will a drug salt with a lower molecular weight counterion. It is desirable to choose a drug form which has the highest potency per unit weight. The method of preparation of different crystalline polymorphs and noncrystalline forms varies widely from drug to drug. It is desirable that minimally toxic solvents be used in these methods, particularly for the last synthetic step, and particularly if the drug has a tendency to exist as a solvate with the solvent utilized in the last step of synthesis. Preferred drug forms are those which utilize less toxic solvents in their synthesis.
[0021] The ability of a drug to form good tablets at commercial scale depends upon a variety of drug physical properties, such as the Tableting Indices described in Hiestand H, Smith D. Indices of tableting performance. Powder Technology, 1984; 38:145-159. These indices may be used to identify forms of a drug, e.g. of atorvastatin calcium, which have superior tableting performance. One such index is the Brittle Fracture Index (BFI), which reflects brittleness, and ranges from 0 (good—low brittleness) to 1 (poor—high brittleness). Other useful indices or measures of mechanical properties, flow properties, and tableting performance include compression stress, absolute density, solid fraction, dynamic indentation hardness, ductility, elastic modulus, reduced elastic modulus, quasistatic indentation hardness, shear modulus, tensile strength, compromised tensile strength, best case bonding index, worst case bonding index, brittle/viscoelastic bonding index, strain index, viscoelastic number, effective angle of internal friction (from a shear cell test), cohesivity (from a powder avalanche test), and flow variability. A number of these measures are obtained on drug compacts, preferably prepared using a triaxial hydraulic press. Many of these measures are further described in Hancock B, Carlson G, Ladipo D, Langdon B, and Mullarney M. Comparison of the Mechanical Properties of the Crystalline and Amorphous Forms of a Drug Substance. International Journal of Pharmaceutics, 2002; 241:73-85.
[0022] Drug form properties which affect flow are important not just for tablet dosage form manufacture, but also for manufacture of capsules, suspensions, and sachets.
[0023] The particle size distribution of a drug powder can also have large effects on manufacturing processes, particularly through effects on powder flow. Different drug forms have different characteristic particle size distributions.
[0024] From the above discussion, it is apparent that there is no one drug form which is ideal for all therapeutic applications. Thus it is important to seek a variety of unique drug forms, e.g. salts, polymorphs, noncrystalline forms, which may be used in various formulations. The selection of a drug form for a specific formulation or therapeutic application requires consideration of a variety of properties, as described above, and the best form for a particular application may be one which has one specific important good property while other properties may be acceptable or marginally acceptable.
[0025] The present invention answers the need by providing novel forms of atorvastatin magnesium. Thus the present invention provides new forms of atorvastatin magnesium designated Forms A, B, C, D, E, and F. The new forms of atorvastatin magnesium disclosed in the present application offer the advantage of high water solubility. This is an advantage for immediate release dosage forms since such forms need to be fully dissolved in the stomach before passing into the digestive tract.
SUMMARY OF THE INVENTION
[0026] In a first aspect, the present invention comprises a Form A atorvastatin magnesium having one or more of characteristics selected from the group consisting of:
I) an X-ray powder diffraction containing the following 2θ values measured using CuK a radiation: 9.3, 14.3, and 18.4; II) a 13 C shift containing the values: 118.7, 124.4, 140.3, and 141.7 ppm; and III) an 19 F shift containing the values: −108.4, and −112.6 ppm.
[0030] As described herein, the x-ray powder diffraction (XRPD) pattern is expressed in terms of degree 2θ and relative intensities with a relative intensity of >10% and relative peak width measured on a Bruker D8 Discover X-ray powder diffractometer with GADDS (General Area Diffraction Detector System) CS (available from Bruker AXS, Inc., 5465 East Cheryl Parkway, Madison, Wis.) operating in reflection mode using CuK a radiation (1.54 Å). Furthermore, in each aspect, the invention encompasses experimental deviation in the 2θ and the shift values described herein; including the deviation ±0.2° 2θ as provided in X-ray powder diffraction (XRPD) Tables 1-7, and deviation ±0.2 ppm as provided in solid state nuclear magnetic resonance (SSNMR) Tables 8-19 below. Based on the descriptions set forth herein, such experimental deviation in the 2θ and the shift values can be readily determined by the ordinarily skilled artisan.
[0031] In one embodiment, the Form A atorvastatin magnesium of the invention has an X-ray powder diffraction containing the following 2θ values measured using CuK a radiation: 9.3, 11.7, 14.3, and 18.4
[0032] In another embodiment, the Form A atorvastatin magnesium of the invention has an X-ray powder diffraction containing the 2θ values measured using CuK a radiation as set forth in Table 1 and Table 7 below.
[0033] In another embodiment, the Form A atorvastatin magnesium of the invention has a solid state NMR shift selected from the group consisting of:
A) a 13 C shift containing the values: 118.7, 124.4, 140.3, and 141.7 ppm; and B) an 19 F shift containing the values: −108.4, and −112.6 ppm.
[0036] In another embodiment, the Form A atorvastatin magnesium of the invention has a 13 C shift containing the values: 118.7, 124.4, 140.3, and 141.7 ppm.
[0037] In another embodiment, the Form A atorvastatin magnesium of the invention has a 13 C shift containing the values set forth in Table 8.
[0038] In another embodiment, the Form A atorvastatin magnesium of the invention has a an 19 F shift containing the values: −108.4, and −112.6 ppm.
[0039] In another embodiment, the Form A atorvastatin magnesium of the invention has an X-ray powder diffraction containing the following 2θ values measured using CuK a radiation: 9.3, 14.3, and 18.4; a 13 C shift containing the values: 118.7, 124.4, 140.3, and 141.7 ppm; and an 19 F shift containing the values: −108.4, and −112.6 ppm.
[0040] In a second aspect, the present invention is directed to Form B atorvastatin magnesium characterized by x-ray powder diffraction (XRPD) pattern expressed in terms of degree 2θ and relative intensities with a relative intensity of >10% and relative peak width measured on a Bruker D8 Discover X-ray powder diffractometer with GADDS (General Area Diffraction Detector System) CS operating in reflection mode using CuK a radiation (1.54 Å) as set forth in Table 2 and Table 7 below.
[0041] In a third aspect, the present invention is directed to Form C atorvastatin magnesium characterized by x-ray powder diffraction (XRPD) pattern expressed in terms of degree 2θ and relative intensities with a relative intensity of >10% and relative peak width measured on a Bruker D8 Discover X-ray powder diffractometer with GADDS (General Area Diffraction Detector System) CS operating in reflection mode using CuK a radiation (1.54 Å) as set forth in Table 3 and Table 7 below.
[0042] In a fourth aspect, the present invention is directed to Form D atorvastatin magnesium characterized by x-ray powder diffraction (XRPD) pattern expressed in terms of degree 28 and relative intensities with a relative intensity of >10% and relative peak width measured on a Bruker D8 Discover X-ray powder diffractometer with GADDS (General Area Diffraction Detector System) CS operating in reflection mode using CuK a radiation (1.54 Å) as set forth in Table 4 and Table 7 below.
[0043] In a fifth aspect, the present invention is directed to Form E atorvastatin magnesium characterized by x-ray powder diffraction (XRPD) pattern expressed in terms of degree 28 and relative intensities with a relative intensity of >10% and relative peak width measured on a Bruker D8 Discover X-ray powder diffractometer with GADDS (General Area Diffraction Detector System) CS operating in reflection mode using CuK a radiation (1.54 Å) as set forth in Table 5 and Table 7 below.
[0044] In a sixth aspect, the present invention is directed to Form F atorvastatin magnesium characterized by x-ray powder diffraction (XRPD) pattern expressed in terms of degree 2θ and relative intensities with a relative intensity of >10% and relative peak width measured on a Bruker D8 Discover X-ray powder diffractometer with GADDS (General Area Diffraction Detector System) CS operating in reflection mode using CuK a radiation (1.54 Å) as set forth in Table 6 and Table 7 below.
[0045] A further embodiment of the invention is a pharmaceutical composition comprising Form A, B, C, D, E, or F of atorvastatin magnesium in admixture with at least one pharmaceutically acceptable excipient, diluent, or carrier, each as described herein.
[0046] The atorvastatin magnesium Forms A, B, C, D, E and F disclosed herein may be used in the treatments and regimens and at the dosage ranges for which atorvastatin calcium (LIPITOR®) is known in the art to be useful. As inhibitors of HMG-CoA reductase, Forms A, B, C, D, E, and F of atorvastatin magnesium are useful as hypolipidemic and hypocholesterolemic agents as well as agents in the treatment of osteoporosis, benign prostatic hyperplasia (BPH), and Alzheimer's disease. Accordingly, a still further embodiment of the present invention is a method of treating hyperlipidemia, hypercholesterolemia, osteoporsis, benign prostatic hyperplasia (BPH), and Alzheimer's disease comprising the step of administering to a patient suffering therefrom a therapeutically effective amount of Form A, Form B, Form C, Form D, Form E, or Form F atorvastatin magnesium, each as described herein, in unit dosage form.
[0047] The invention further provides for the use of Form A, Form B, Form C, Form D, Form E, or Form F atorvastatin magnesium, each as described herein, in the preparation of a medicament for the treatment of hyperlipidemia, hypercholesterolemia, osteoporosis, benign prostatic hyperplasia, or Alzheimer's disease. Also, the invention provides for the use of Form A, Form B, Form C, Form D, Form E, or Form F atorvastatin magnesium, or a combination of two or more of these forms, each as described herein, in the treatment of hyperlipidemia, hypercholesterolemia, osteoporosis, benign prostatic hyperplasia, or Alzheimer's disease.
[0048] Finally, the present invention is directed to methods for production of Form A, Form B, Form C, Form D, Form E, or Form F atorvastatin magnesium, each as described herein.
BRIEF DESCRIPTION OF THE DRAWINGS
[0049] FIG. 1 : Diffractogram of Form A atorvastatin magnesium measured on a Bruker D8 DISCOVER with GADDS (General Area Diffraction Detector System) CS X-ray powder diffractometer.
[0050] FIG. 2 : Diffractogram of Form B atorvastatin magnesium measured on a Bruker D8 DISCOVER with GADDS CS X-ray powder diffractometer.
[0051] FIG. 3 : Diffractogram of Form C atorvastatin magnesium measured on a Bruker D8 DISCOVER with GADDS CS X-ray powder diffractometer.
[0052] FIG. 4 : Diffractogram of Form D atorvastatin magnesium measured on a Bruker D8 DISCOVER with GADDS CS X-ray powder diffractometer.
[0053] FIG. 5 : Diffractogram of Form E atorvastatin magnesium measured on a Bruker D8 DISCOVER with GADDS CS X-ray powder diffractometer.
[0054] FIG. 6 : Diffractogram of Form F atorvastatin magnesium measured on a Bruker D8 DISCOVER with GADDS CS X-ray powder diffractometer.
[0055] FIG. 7 : Proton decoupled 13 C CPMAS spectra of Form A atorvastatin magnesium. The peaks marked with an asterisk are spinning sidebands.
[0056] FIG. 8 : Proton decoupled 13 C CPMAS spectra of Form B atorvastatin magnesium. The peaks marked with an asterisk are spinning sidebands.
[0057] FIG. 9 : Proton decoupled 13 C CPMAS spectra of Form C atorvastatin magnesium. The peaks marked with an asterisk are spinning sidebands.
[0058] FIG. 10 : Proton decoupled 13 C CPMAS spectra of Form D atorvastatin magnesium. The peaks marked with an asterisk are spinning sidebands.
[0059] FIG. 11 : Proton decoupled 13 C CPMAS spectra of Form E atorvastatin magnesium. The peaks marked with an asterisk are spinning sidebands.
[0060] FIG. 12 : Proton decoupled 13 C CPMAS spectra of Form F atorvastatin magnesium. The peaks marked with an asterisk are spinning sidebands.
[0061] FIG. 13 : Proton decoupled 19 F MAS spectra of Form A atorvastatin magnesium. The peaks marked with an asterisk are spinning sidebands.
[0062] FIG. 14 : Proton decoupled 19 F MAS spectra of Form B atorvastatin magnesium. The peaks marked with an asterisk are spinning sidebands.
[0063] FIG. 15 : Proton decoupled 19 F MAS spectra of Form C atorvastatin magnesium. The peaks marked with an asterisk are spinning sidebands.
[0064] FIG. 16 : Proton decoupled 19 F MAS spectra of Form D atorvastatin magnesium. The peaks marked with an asterisk are spinning sidebands.
[0065] FIG. 17 : Proton decoupled 19 F MAS spectra of Form E atorvastatin magnesium. The peaks marked with an asterisk are spinning sidebands.
[0066] FIG. 18 : Proton decoupled 19 F MAS spectra of Form F atorvastatin magnesium. The peaks marked with an asterisk are spinning sidebands.
DETAILED DESCRIPTION OF THE INVENTION
[0067] Form A, Form B, Form C, Form D, Form E, and Form F atorvastatin magnesium can be characterized by one or more of x-ray powder diffraction-, solid state NMR carbon chemical shift-, and solid state NMR fluorine chemical shift patterns.
[0068] The “forms” of atorvastatin magnesium disclosed in the present invention may exist as ordered crystals, disordered crystals, liquid crystals, plastic crystals, mesophases, and the like. In X-ray powder diffractograms forms that are related through disorder will have essentially the same major peak positions but the disordering process will cause broadening of these peaks. For many of the weaker peaks, the broadening may be so severe that they are no longer visible above the background. The peak broadening caused by disorder may in addition cause errors in the location of the exact peak position. For solid state nuclear magnetic resonance (SSNMR) spectra, significant differences in chemical shifts may be seen from crystalline to disordered phases.
EXPERIMENTAL
X-Ray Powder Diffraction
[0069] Form A, Form B, Form C, Form D, Form E, and Form F atorvastatin magnesium were characterized by their X-ray powder diffraction pattern. Thus, the X-ray powder diffraction patterns of Forms A, B, C, D, E, and F were carried out on a Bruker D8 Discover X-ray powder diffractometer with GADDS (General Area Diffraction Detector System) CS operating in reflection mode using Cu K a radiation. The tube voltage and amperage were set to 40 kV and 40 mA, respectively. Scans were collected with the sample to detector distance set at 15.0 cm. The samples were scanned for a period of 60 seconds covering a range of 4.5° to 38.7° in 2θ. The diffractometer was calibrated for peak positions in 2θ using a corundum standard. Samples were run in ASC-6 silicon sample holders purchased from Gem Dugout (State College, Pa.). All analyses were conducted at room temperature, which is generally 20°-30° C. Data were collected and integrated using GADDS for WNT software version 4.1.14T. Diffractograms were evaluated using DiffracPlus software, release 2003, with Eva version 8.0 (available from Bruker AXS, Inc., Madison, Wis.).
[0070] To perform an X-ray diffraction measurement on a Bruker D8 Discover X-ray powder diffractometer with GADDS CS used for measurements reported herein, the sample is typically placed into a cavity in the middle of the silicon sample holder. The sample powder is pressed by a glass slide or equivalent to ensure a random surface and proper sample height. The sample holder is then placed into the Bruker instrument and the powder x-ray diffraction pattern is collected using the instrumental parameters specified above. Measurement differences associated with such X-ray powder diffraction analyses result from a variety of factors including: (a) errors in sample preparation (e.g., sample height), (b) instrument errors (e.g. flat sample errors), (c) calibration errors, (d) operator errors (including those errors present when determining the peak locations), and (e) the nature of the material (e.g. preferred orientation and transparency errors). Calibration errors and sample height errors often result in a shift of all the peaks in the same direction. Small differences in sample height when using a flat holder will lead to large displacements in XRPD peak positions. A systematic study showed that a sample height difference of 1 mm lead to peak shifts as high as 1° 2θ (Chen et al.; J Pharmaceutical and Biomedical Analysis, 2001; 26, 63). These shifts can be identified from the X-ray diffractogram and can be eliminated by compensating for the shift (applying a systematic correction factor to all peak position values) or recalibrating the instrument. As mentioned above, it is possible to rectify measurements from the various instruments by applying a systematic correction factor to bring the peak positions into agreement. In general, this correction factor will bring the measured peak positions into agreement with the expected peak positions and is in the range of the expected 2θ value ±0.2° 2θ.
[0071] Tables 1-6 list peak positions in degrees 2θ, relative intensities, and relative peak widths for X-ray powder diffraction patterns of each form of atorvastatin magnesium disclosed in the present application. The relatively narrow peak positions were picked by the DiffracPlus with Eva version 8.0 software. The broader peak positions were visually determined. All peak positions were rounded to 0.1° 2θ. The following abbreviations are used in Tables 1-6 to describe the peak intensity (s=strong; m=medium; w=weak) and the peak width (b=broad (where broad refers to peak widths of between 0.2 and 1.0 degrees 2θ, sh=shoulder, vb=very broad (where very broad refers to peaks with >1 degrees 2θ peak width)).
[0000]
TABLE 1
XPRD Peak List for Form A Atorvastatin magnesium
Relative
degree 2θ ± 0.2
Relative Intensity a
Peak Width b
9.3
w
b
11.7
w
b
14.3
w
b
18.4
s
b
[0000]
TABLE 2
XPRD Peak List for Form B Atorvastatin magnesium
Relative Peak
degree 2θ ± 0.2
Relative Intensity a
Width b
5.3
w
b
6.1
w
b
8.0
w
b
9.1
w
b
10.5
w
b, sh
10.9
m
b
13.2
w
b
13.9
w
b
15.6
m
b
16.1
w
b
16.7
w
b
17.2
w
b
18.1
s
b, sh
18.4
s
b
19.8
s
b
20.7
w
b, sh
21.2
m
b
21.8
m
b
23.0
w
b
24.1
w
b
24.8
w
b
25.6
w
b
27.3
w
b
29.1
w
b
[0000]
TABLE 3
XPRD Peak List for Form C Atorvastatin magnesium
Relative Peak
degree 2θ ± 0.2
Relative Intensity a
Width b
5.2
w
b
6.6
w
b
8.7
s
b
9.8
w
b
11.6
m
b
12.3
m
b
13.5
m
b
14.6
m
b
16.2
m
b
18.7
s
vb
19.9
s
b, sh
23.2
s
vb
[0000]
TABLE 4
XPRD Peak List for Form D atorvastatin magnesium
Relative Peak
degree 2θ ± 0.2
Relative Intensity a
Width b
7.7
m
b
8.8
m
b
10.2
m
b
11.9
w
b
13.8
w
b
15.9
s
b
17.3
m
b
18.7
s
b
20.5
s
vb
24.2
m
b
26.7
w
b
30.6
w
vb
[0000]
TABLE 5
XPRD Peak List for Form E atorvastatin magnesium
degree 2θ ± 0.2
Relative Intensity a
Relative Peak Width b
8.4
m
b
10.0
m
b
11.1
w
b
12.4
w
b
14.0
w
b
16.6
s
b
17.9
s
b
20.2
s
b
22.0
s
b, sh
23.1
s
b, sh
26.3
m
vb
30.3
m
vb
[0000]
TABLE 6
XPRD Peak List for Form F atorvastatin magnesium
degree 2θ ± 0.2
Relative Intensity a
Relative Peak Width b
8.7
m
b
10.1
s
b
11.7
w
b
12.7
w
b
14.7
w
b
16.1
s
b
17.5
m
b
18.5
m
b
20.4
s
b, sh
21.4
s
vb, sh
23.7
m
vb
26.8
w
vb
30.4
m
vb
[0072] Table 7 lists combinations of 20 peaks for Forms A, B, C, D, E, and F atorvastatin magnesium, i.e., a set of x-ray diffraction lines that are unique to each form
[0000]
TABLE 7
degree
Form
2θ ± 0.2
A
9.3
14.3
18.4
B
6.1
8.0
10.9
19.8
23.0
C
5.2
6.6
12.3
D
7.7
20.5
24.2
E
8.4
16.6
17.9
F
8.7
10.1
11.7
16.1
Solid State NMR Spectroscopy
[0073] For both 13 C-, and 19 F spectroscopy, approximately 80 mg of each sample were tightly packed into a 4 mm ZrO spinner. The spectra were collected at ambient conditions on a Bruker-Biospin 4 mm BL HFX CPMAS probe (Bruker BioSpin Corporation, 15 Fortune Drive, Manning Park, Billerica, Mass. 01821-3991) positioned into a wide-bore Bruker-Biospin Avance DSX 500 MHz NMR spectrometer. The samples were positioned at the magic angle and spun at 15.0 kHz, corresponding to the maximum specified spinning speed for the 4 mm spinners. The fast spinning speed minimized the intensities of the spinning side bands. The number of scans was adjusted to obtain adequate S/N.
[0074] 13 C Spectroscopy
[0075] The 13 C solid state spectra were collected using a proton decoupled cross-polarization magic angle spinning experiment (CPMAS). The Hartman-Hahn contact time was set to 2.0 ms. The proton decoupling field of approximately 90 kHz was applied. 2048 scans were collected. The recycle delay was adjusted to 7 seconds. The shift values are listed in Tables 8 to 13. The spectra were referenced using an external standard of crystalline adamantane, setting its upfield resonance to 29.5 ppm.
[0000]
TABLE 8
Carbon chemical shifts in ppm of Form A atorvastatin magnesium
13 C Chemical Shifts a
[ppm] ± 0.2
Intensity b
180.3
0.8
177.9
0.6
168.0
0.1
166.6
1.3
163.5
0.5
161.6
1.1
141.7
1.5
140.3
0.8
134.9
1.2
129.3
4.7
124.4
12.0
123.3
2.9
118.7
3.5
117.4
4.3
116.1
3.6
70.3
4.0
68.0
1.7
67.2
1.5
42.3
1.5
36.4
4.2
26.6
0.1
22.2
4.2
[0000]
TABLE 9
Carbon chemical shifts in ppm of Form B atorvastatin magnesium
13 C Chemical Shifts a
[ppm] ± 0.2
Intensity b
183.5
1.2
180.4
Peak shoulder
178.7
0.8
166.0
2.3
163.6
1.4
161.7
2.0
139.3
5.0
136.1
5.2
133.8
4.6
132.2
3.4
129.6
12.0
126.8
4.5
125.4
4.3
122.9
1.5
120.9
1.8
119.7
1.8
118.3
1.7
115.8
4.4
72.9
2.8
71.0
5.0
45.6
2.2
43.3
6.8
41.6
5.4
41.0
5.5
27.1
5.4
26.9
5.1
24.9
3.6
24.3
4.0
22.1
1.9
19.5
8.9
[0000]
TABLE 10
Carbon chemical shifts in ppm of Form C atorvastatin magnesium
13 C Chemical Shifts a
[ppm] ± 0.2
Intensity b
180.6
0.8
179.9
0.8
167.6
1.4
163.3
1.1
161.5
1.4
141.2
0.9
139.1
1.6
135.3
4.6
133.3
3.9
129.2
12.0
126.3
4.3
123.1
3.8
119.7
3.6
117.8
3.5
116.0
3.1
71.1
1.6
67.6
1.3
43.1
3.5
42.4
3.5
26.6
3.4
22.4
4.4
[0000]
TABLE 11
Carbon chemical shifts in ppm of Form D atorvastatin magnesium
13 C Chemical Shifts a
[ppm] ± 0.2
Intensity b
183.1
1.2
182.4
1.6
179.9
1.8
176.5
0.6
165.9
2.3
163.4
1.4
162.7
1.4
161.4
2.1
160.8
1.8
141.3
1.0
138.6
6.5
136.9
2.8
136.4
3.0
135.0
6.3
134.4
5.1
132.6
4.7
131.5
7.4
130.5
8.4
129.4
12.0
128.3
10.2
126.4
2.7
124.1
5.5
123.2
2.8
121.0
6.9
117.1
5.0
115.2
3.9
114.3
2.0
71.5
1.8
70.4
2.4
69.3
4.3
67.4
2.5
66.5
4.5
46.5
2.4
45.6
3.5
44.2
4.4
43.2
5.9
41.4
2.7
39.7
4.0
37.6
0.8
27.2
6.8
26.8
5.8
24.6
2.7
23.7
3.5
22.9
3.4
21.5
1.8
20.9
1.3
19.1
3.9
[0000]
TABLE 12
Carbon chemical shifts in ppm of Form E atorvastatin magnesium
13 C Chemical Shifts a
[ppm] ± 0.2
Intensity b
181.0
0.8
166.4
2.2
162.6
1.4
160.7
1.9
137.8
5.0
135.2
8.5
131.5
6.1
129.6
11.0
128.9
12.0
123.8
3.9
122.0
3.6
117.7
2.6
115.6
1.7
114.9
1.6
67.9
1.7
67.0
1.9
43.2
3.9
41.7
2.7
41.1
2.6
26.6
5.3
24.0
4.3
21.0
3.6
[0000]
TABLE 13
Carbon chemical shifts in ppm of Form F atorvastatin magnesium
13 C Chemical Shifts a
[ppm] ± 0.2
Intensity b
182.6
1.1
180.0
1.3
166.0
3.0
162.9
1.0
162.6
1.1
161.1
1.6
160.7
1.6
138.2
6.5
136.3
3.2
135.1
8.2
131.4
7.1
130.4
5.6
129.4
9.5
128.5
12.0
124.0
5.5
121.0
4.5
117.4
2.9
115.1
1.7
114.2
1.8
69.1
1.6
67.4
1.9
66.4
3.6
46.4
1.7
45.6
2.0
43.2
2.8
40.0
1.8
39.3
1.6
27.0
4.5
23.4
3.4
23.1
3.4
19.4
3.3
[0076] In each of Tables 8-13, “a” is referenced to external sample of solid phase adamantane at 29.5 ppm; and “b” is defined as peak height. Intensities can vary depending on the actual setup of the CPMAS experimental parameters and the thermal history of the sample. CPMAS intensities are not necessarily quantitative.
[0077] 19 F Spectroscopy
[0078] The 19 F solid state spectra were collected using a proton decoupled magic angle spinning (MAS) experiment. The proton decoupling field of approximately 90 kHz was applied. 32 scans were collected. The recycle delay was set to 90 seconds to ensure acquisition of quantitative spectra. Proton longitudinal relaxation times ( 1 H T 1 ) were calculated based on a fluorine detected proton inversion recovery relaxation experiment. Fluorine longitudinal relaxation times ( 19 F T 1 ) were calculated based on a fluorine detected fluorine inversion recovery relaxation experiment. The spectra were referenced using an external sample of trifluoro-acetic acid (50% V/V in H 2 O), setting its resonance to −76.54 ppm. Tables 14 to 19 list the fluorine chemical shifts in ppm of Forms A, B, C, D, E, and F atorvastatin magnesium respectively.
[0000]
TABLE 14
19 F Chemical Shifts
[ppm] ± 0.2
−108.4 (shoulder)
−112.6
[0000]
TABLE 15
19 F Chemical Shifts
[ppm] ± 0.2
−115.7
[0000]
TABLE 16
19 F Chemical Shifts
[ppm] ± 0.2
−109.6 (shoulder)
−113.0
[0000]
TABLE 17
19 F Chemical Shifts
[ppm] ± 0.2
−110.0
−111.7
−114.7
−119.8
[0000]
TABLE 18
19 F Chemical Shifts a
[ppm] ± 0.2
−113.2
−118.8
−122.1 (shoulder)
[0000]
TABLE 19
19 F Chemical Shifts
[ppm] ± 0.2
−114.7
−118.8 (shoulder)
−119.8
−122.3
[0079] The forms of atorvastatin magnesium described herein may exist in anhydrous forms as well as containing various amounts of water and/or solvents. Anhydrous, hydrated and solvated forms of atorvastatin magnesium are intended to be encompassed within the scope of the present invention. The forms of atorvastatin magnesium described herein, regardless of the extent of water and/or solvent having equivalent x-ray powder diffractograms are within the scope of the present invention.
[0080] The new forms of atorvastatin magnesium described herein have advantageous properties.
[0081] The ability of a material to form good tablets at commercial scale depends upon a variety of physical properties of the drug, such as, for example, the Tableting Indices described in Hiestand H. and Smith D., Indices of Tableting Performance, Powder Technology, 1984, 38; 145-159. These indices may be used to identify forms of atorvastatin magnesium which have superior tableting performance. One such index is the Brittle Fracture Index (BFI), which reflects brittleness, and ranges from 0 (good—low brittleness) to 1 (poor—high brittleness).
[0082] The present invention provides a process for the preparation of Forms A, B, C, D, E and F atorvastatin magnesium which comprises forming atorvastatin magnesium (e.g., from a solution or slurry in solvents) under conditions which yield Forms A, B, C, D, E and F atorvastatin magnesium.
[0083] The precise conditions under which Forms A, B, C, D, E and F atorvastatin magnesium are formed may be empirically determined and described herein are methods which have been found to be suitable in practice.
[0084] The compounds of the present invention can be prepared and administered in a wide variety of oral and parenteral dosage forms. The compounds of the present invention can be administered by injection, that is, intravenously, intramuscularly, intracutaneously, subcutaneously, intraduodenally, or intraperitoneally. Also, the compounds of the present invention can be administered by inhalation, for example, intranasally. Additionally, the compounds of the present invention can be administered transdermally. It will be obvious to those skilled in the art that the following dosage forms may comprise as the active component a compound of the present invention.
[0085] For preparing pharmaceutical compositions from the compounds of the present invention, pharmaceutically acceptable carriers can be either solid or liquid. Solid form preparations include powders, tablets, pills, capsules, cachets, suppositories, and dispersible granules. A solid carrier can be one or more substances which may also act as diluents, flavoring agents, solubilizers, lubricants, suspending agents, binders, preservatives, tablet disintegrating agents, or an encapsulation material.
[0086] In powders, the carrier is a finely divided solid which is in a mixture with the finely divided active component.
[0087] In tablets, the active component is mixed with the carrier having the necessary binding properties in suitable proportions and compacted in the shape and size desired.
[0088] The powders and tablets preferably contain from two or ten to about seventy percent of the active compound. Suitable carriers are magnesium carbonate, methylcellulose, sodium carboxymethylcellulose, a low melting wax, cocoa butter, and the like. The term ‘preparation’ is intended to include the formulation of the active compound with encapsulating material as a carrier providing a capsule in which the active component, with or without other carriers, is surrounded by a carrier, which is thus in association with it. Similarly, cachets and lozenges are included. Tablets, powders, capsules, pills, cachets, and lozenges can be used as solid dosage forms suitable for oral administration.
[0089] For preparing suppositories, a low melting wax, such as a mixture of fatty acid glycerides or cocoa butter, is first melted and the active component is dispersed homogeneously therein, as by stirring. The molten homogeneous mixture is then poured into convenient sized molds, allowed to cool, and thereby to solidify.
[0090] Liquid form preparations include solutions, suspensions, retention enemas, and emulsions, for example water or water propylene glycol solutions. For parenteral injection, liquid preparations can be formulated in solution in aqueous polyethylene glycol solution.
[0091] Aqueous solutions suitable for oral use can be prepared by dissolving the active component in water and adding suitable colorants, flavors, stabilizing and thickening agents, as desired.
[0092] Aqueous suspensions suitable for oral use can be made by dispersing the finely divided active component in water with viscous material, such as natural or synthetic gums, resins, methylcellulose, sodium carboxymethylcellulose, and other well-known suspending agents.
[0093] Also included are solid form preparations which are intended to be converted, shortly before use, to liquid form preparations for oral administration. Such liquid forms include solutions, suspensions, and emulsions. These preparations may contain, in addition to the active component, colorants, flavors, stabilizers, buffers, artificial and natural sweeteners, dispersants, thickeners, solubilizing agents, and the like.
[0094] The pharmaceutical preparation is preferably in unit dosage form. In such form, the preparation is subdivided into unit doses containing appropriate quantities of the active component. The unit dosage form can be a packaged preparation, the package containing discrete quantities of preparation, such as packeted tablets, capsules, and powders in vials or ampoules. Also, the unit dosage form can be a capsule, tablet, cachet, or lozenge itself, or it can be the appropriate number of any of these in packaged form.
[0095] The quantity of active component in a unit dosage preparation may be varied or adjusted from 0.5 mg to 100 mg, preferably 2.5 to 80 mg according to the particular application and the potency of the active component. The composition can, if desired, also contain other compatible therapeutic agents.
[0096] In therapeutic use as hypolipidemic and/or hypocholesterolemic agents and agents to treat BPH, osteoporosis, and Alzheimer's disease, the Forms A, B, C, D, E, and F atorvastatin magnesium utilized in a method of this invention are administered at the initial dosage of about 2.5 mg to about 80 mg daily. Useful daily doses includes those in the range of about 2.5 mg to about 20 mg. The dosages, however, may be varied depending upon the requirements of the patient, the severity of the condition being treated, and the compound being employed. Determination of the proper dosage for a particular situation is within the skill of the art. Generally, treatment is initiated with smaller dosages which are less than the optimum dose of the compound. Thereafter, the dosage is increased by small increments until the optimum effect under the circumstance is reached. For convenience, the total daily dosage may be divided and administered in portions during the day if desired.
[0097] Form A of atorvastatin magnesium may be prepared by dissolving the lactone form of atorvastatin (U.S. Pat. No. 5,273,995) in a solvent in which both the lactone and sodium salt forms are soluble. Useful solvents include lower weight alcohols, such as methanol and ethanol, water or tetrahydrofuran (THF) or mixtures thereof. NaOH is added to the solution, with stirring, at a temperature from about 45° C. to about 55° C., followed by slow addition of a magnesium salt, such as MgCl 2 or a hydrated form thereof. The mixture can them be cooled to ambient temperature to yield a suspension and a precipitate, which can be filtered from the suspension. Water can then be slowly added to the resulting solution with stirring to produce a second precipitate of atorvastatin magnesium Form A, which can then be removed by filtration.
[0098] Atorvastatin magnesium Form B may be prepared by suspending a sample of Form A, discussed above, in an aromatic organic solvent, such as benzene, xylene, ortho-xylene, para-xylene, meta-xylene, toluene, etc., at a temperature from about 40° C. to about 80° C. and stirring until From B atorvastatin magnesium is obtained.
[0099] Atorvastatin magnesium Form C may be obtained by suspending a sample of Form A, described above, in a mixture of acetonitrile and water at ambient temperature, with the acetonitrile being no more than 80% but no less than 50% of the acetonitrile/water mixture (volume/volume). The resulting mixture may then be stirred at ambient temperature until Form C is produced.
[0100] Form D atorvastatin magnesium may be prepared by suspending a sample of Form A, described above, in a mixture of about 9/1 (volume/volume) 2-propanol/water at ambient temperature and stirring the resulting mixture until Form D is obtained.
[0101] Form E atorvastatin magnesium may be prepared by suspending a sample of Form A, described above, in water at ambient temperature and stirring until Form E is obtained.
[0102] Form F atorvastatin magnesium may be obtained by suspending a sample of Form A, described above, in water at a temperature from about 45° C. to about 100° C. and stirring the resulting mixture until Form F is obtained.
[0103] Those skilled in the art will understand the forms of atorvastatin magnesium will be obtained in different amounts depending upon the amount of time spent in the steps above. Amounts of the desired forms may be obtained in periods from one day to 50 days by the methods above. It will also be understood that methods known in the art may be used to obtain the desired atorvastatin magnesium material from the resulting suspension, such as centrifuge filtration.
[0104] The following nonlimiting examples illustrate methods for preparing the compounds of the invention:
Example 1
[R—(R*,R*)]-2-(4-fluorophenyl)-α,δ-dihydroxy-5-(1-methylethyl)-3-phenyl-4-[(phenylamino)carbonyl]-1H-pyrrole-1-heptanoic acid hemi magnesium salt (Forms A, B, C, D, E, and F atorvastatin magnesium)
Form A Atorvastatin Magnesium
[0105] A 6.0 g sample of the lactone form of atorvastatin (U.S. Pat. No. 5,273,995) was dissolved in 100 mL of methanol at room temperature. Approximately 11.8 mL of 1 N NaOH (1.05 mol equivalents) was then added to the mixture. The solution was then stirred at 50° C. for approximately 1 hour. A solution of 1.19 g MgCl 2 .6H 2 O in 5 mL of H 2 O (0.55 mol equivalents) was then slowly added to the reaction mixture. The mixture was then cooled to room temperature and the resulting precipitate was removed by vacuum filtration through a 0.45-μm nylon membrane filter. Approximately 100 mL of H 2 O was then slowly added to the filtered solution, which caused a white precipitate to form. The resulting suspension was then stirred for approximately 30 minutes. The solid sample was then isolated by vacuum filtration. The filtered solid was then dried under vacuum at 70° C. for approximately 2 hours to afford 5.8 g of Form A atorvastatin magnesium.
Form B Atorvastatin Magnesium
[0106] A 50 mg sample of Form A atorvastatin magnesium (prepared as described above) was slurried in 0.25 mL of ortho-xylene at 45° C. for 28 days using magnetic stirring at 400 rpm. The solid sample was then isolated by centrifuge filtration through a 0.45-μm nylon membrane filter. The filtered solid was then air dried under ambient conditions for approximately 5 hours to afford Form B atorvastatin magnesium.
Form C Atorvastatin Magnesium
[0107] A 50 mg sample of Form A atorvastatin magnesium (prepared as described above) was slurried in 0.75 mL of acetonitrile:water (8:2, v/v) at ambient temperature for 28 days using magnetic stirring at 300 rpm. The solid sample was then isolated by centrifuge filtration through a 0.45-μm nylon membrane filter. The filtered solid was then air dried under ambient conditions for approximately 5 hours to afford Form C atorvastatin magnesium.
Form D Atorvastatin Magnesium
[0108] A 50 mg sample of Form A atorvastatin magnesium (prepared as described above) was slurried in 1 mL of 2-propanol:water (9:1, v/v) at ambient temperature for 28 days using magnetic stirring at 300 rpm. The solid sample was then isolated by centrifuge filtration through a 0.45-μm nylon membrane filter. The filtered solid was then air dried under ambient conditions for approximately 5 hours to afford Form D atorvastatin magnesium.
Form E Atorvastatin Magnesium
[0109] A 50 mg sample of Form A atorvastatin magnesium (prepared as described above) was slurried in 3 mL of water at ambient temperature for 28 days using magnetic stirring at 300 rpm. The solid sample was then isolated by centrifuge filtration through a 0.45-μm nylon membrane filter. The filtered solid was then air dried under ambient conditions for approximately 5 hours to afford Form E atorvastatin magnesium.
Form F Atorvastatin Magnesium
[0110] A 50 mg sample of Form A atorvastatin magnesium (prepared as described above) was slurried in 1 mL of water at 45° C. for 28 days using magnetic stirring at 300 rpm at 400 rpm. The solid sample was then isolated by centrifuge filtration through a 0.45-μm nylon membrane filter. The filtered solid was then air dried under ambient conditions for approximately 5 hours to afford Form F atorvastatin magnesium. | Novel forms of atorvastatin magnesium salt designated Form A, Form B, Form C, Form D, Form E, and Form F, pharmaceutical compositions containing such compounds, methods for their preparation and methods utilizing the compounds for treatment of hyperlipidemia, hypercholesterolemia, osteoporosis, benign prostatic hyperplasia (BPH) and Alzheimer's disease are described. | 2 |
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a continuation application claiming priority to U.S. application Ser. No. 12/664,190 filed Dec. 11, 2009, which is a U.S. National Stage Application of PCT/GB09/50030 filed Jan. 16, 2009, which claims priority to GB Application No. 0805207.8 filed Mar. 20, 2008, the contents of each of which are incorporated by reference herein.
TECHNICAL FIELD AND BACKGROUND OF THE INVENTION
[0002] This invention relates to industrial apparatus, namely a pulveriser or grinding mill, in which pieces of a material are pulverised into a finer particulate form. The invention relates particularly, but not exclusively, to a mill in which coal is pulverised into a powder form which is conveyed to combustion apparatus e.g. of a power station.
[0003] In particular the invention concerns a mill having a lower grinding ring, which may be a part formed with an annular depression. Grinding elements are sandwiched between the lower grinding ring and a top member, which may have an annular depression facing an annular depression in the grinding ring. The grinding ring and the top member are moveable relative to one another. The grinding ring and the top member are typically ring-shaped; the terms “grinding ring” and “top ring” may hereinafter be used.
[0004] Typically the required relative movement between the grinding elements and the lower grinding ring is achieved by driving the grinding ring, while the top ring is held against rotation. The grinding elements, which are typically steel balls or rollers, are not driven. They may be fixed in position, or free to precess.
[0005] The mill with which the invention is concerned is of the type having a rotating port ring generally as described in EP 0507983A. Such a port ring is provided, between the periphery or circumference of the grinding ring and an inclined liner (which may also be called a skirt, or gusset) carried by the wall of the mill. There is provided an annular passage or “throat”, just outboard of the grinding ring. Air flows upwardly through the port ring. The port ring has inner and outer annular walls, between which there area plurality of spaced-apart, inclined, vanes, separating openings through which air can flow. The port ring rotates with the grinding ring and the vanes impart a desired vector to the generally upwards air flow.
[0006] Around its 360 degree extent the port ring may define only openings and the through-thicknesses of the vanes. That is to say there is in effect an annular passage separated into individual openings only by the through-thicknesses of the vanes.
[0007] The inner and outer annular walls of the port ring are fixed. The gap between them, in which the vanes are located, cannot be varied.
[0008] The size of the gap is selected to provide an optimal air flow rate, which assures efficient advancement of coal fines towards the combustion apparatus. Control of air flow rate is of critical importance in a mill. Too high an air flow rate for a given throughput gives an increased risk that non-combustible materials may be carried forward to the combustion apparatus, along with desired coal fines. Too low an air flow rate, and the coal fines are not all carried to the combustion apparatus, leading to inefficient operation.
[0009] The rotating port ring is an excellent and successful mill feature but it is not optimal with coal sources which give rise to incomplete grinding; especially with coal sources which contain inclusions of rock. In such circumstances some unground pieces may be too big to fall through the port ring, and back into the material to be fed to the grinding zone, or scrapped.
SUMMARY OF THE INVENTION
[0010] In accordance with a first aspect of the present invention there is provided a pulveriser mill having a rotatable grinding ring, and a rotatable port ring around the circumference of the grinding ring, wherein the port ring defines, around its 360 degree extent, a plurality of openings which are separated by lands, the openings permitting air to flow from beneath the grinding ring to above the grinding ring and the lands serving as obstructions to the flow of air from beneath the grinding ring to above the grinding ring, wherein the aspect ratio of the openings (length divided by radial width) is in the range from 1:1 to 3:1.
[0011] Preferably the openings are wide. In the present invention the openings being “wide” means that the openings present a larger gap, in the radial direction, than would be found in a corresponding prior mill not having lands. To consider this, the summated area A of the openings A 1 in the mill of the present invention, separated by lands, may be compared with the summated area B of openings B 1 of a notional port ring of the same diameter, separated instead only by the through-thicknesses of vanes, in a mill which is in all other respects the same as said mill of the present invention. The ratio of A to B is preferably in the range 0.7 to 1.3, preferably 0.9 to 1.1. In other words the summated area is the same or similar. Given the presence of the lands, the openings A 1 must be wider than the openings B 1 , for the summated area A to be the same or similar to the summated area B. Preferably the mean width of the openings A 1 is from 1.1 to 3 times the mean width of the openings B 1 , preferable from 1.5 to 2.5 times the mean width of the openings B 1 . The total area available for air flow is thereby similar.
[0012] Preferably there is present a mill liner outside the port ring, suitably carried on the inside wall of the mill, as an annulus. The liner is typically a downwardly slanted metal skirt or gusset.
[0013] Preferably the port ring is made wider than heretofore by decreasing the width of, or eliminating, the mill liner.
[0014] Preferably the lands in total occupy at least 90 degrees of the 360 degree extent of the port ring, preferably at least 120 degrees, preferably at least 180 degrees, most preferably at least 220 degrees.
[0015] Preferably the lands in total occupy up to 280 degrees of the 360 degree extent of the port ring, preferably up to 260 degrees.
[0016] Preferably the openings in total occupy up to 270 degrees of the 360 degree extent of the port ring, preferably up to 240 degrees, preferably up to 180 degrees, and most preferably up to 140 degrees.
[0017] Preferably the openings in total occupy at least 80 degrees of the 360 degree extent of the port ring, and preferably at least 100 degrees.
[0018] The aspect ratio of the openings may be defined herein as the (mean) length divided by the (mean) width in the radial direction. Preferably the aspect ratio is in the range from 1:1 up to 2.5:1, most preferably from 1.2:1 up to 2.1:1.
[0019] Suitably the openings are generally rectangular (in which case the “length” is the straight length of the opening; orthogonal to the radial width), or are arcuate, preferably following the curvature of the circumference of the port ring (in which case the “length” is measured along the “hoop direction” thereof).
[0020] All measurements and definitions based thereon given in this specification are made with reference to the horizontal plane and/or as viewed from above in plan view.
[0021] Preferably the port ring is co-rotatable with the grinding ring. Preferably it is secured to the grinding ring for rotation therewith and includes a plurality of spaced-apart vanes. The vanes have upper and lower ends, and are preferably oriented at an angle in the range of 20 degrees to 40 degrees relative to a vertical axis of the mill, in a manner such that the lower ends lead, in the direction of rotation of the grinding ring, and the upper ends trail. Preferably adjacent vanes are spanned by respective lands or are left open. Preferably the openings and lands alternate, around the port ring.
[0022] There is typically a running clearance outside the port ring and this is a further opening available for air flow. In one embodiment the area available for air flow is the summation of the port ring openings and the running clearance; there are no further openings. When there is a mill liner the running clearance is suitably between the mill liner and the port ring.
[0023] The prior port ring of EP 507983A exhibits significant advantages over earlier pulveriser mill designs. Most importantly, it provides for air flow upwardly through the port ring in a manner such that the air flow is essentially vertical (as opposed to predominantly spinning or swirling movement obtained with some other apparatus). With such apparatus the air flow provides excellent upward transport of pulverised material (e.g., coal dust) with minimum required air velocity, and with low tendency to lift large particles.
[0024] However it is a limitation that unground pieces of a certain size are not able to fall through the port ring. Rather they may rest on the port ring and block the flow of air.
[0025] The provision of wider openings, but with lands between them, thereby to keep the overall air flow area, and a mess flow rate similar, reduces this problem without compromising mill operation. In fact, to our surprise, we have found that the measures of the present invention appear to lead to a general improvement in mill performance, going beyond the improvement in dealing with unground pieces. We have no explanation for this other than suggesting (without being bound by theory) that the “injection” of distinct or isolated streams of air produces a more effective air flow pattern above the port ring.
[0026] The openings defined herein may be spanned by one or more members, for example cross-bars, and in such cases for the purposes of the definitions herein (e.g. angular extent, width, area, aspect ratio) the length of an opening is regarded as the summation of the (mean) span of the visible or unoccluded portions of the opening in the lengthwise direction and the width of an opening is regarded as the summation of the (mean) span of the visible or unoccluded portions of the opening in the widthwise direction; in each case when viewed from above in plan. Preferably, however, the openings do not have any such members. Preferably they are entirely unoccluded.
[0027] Preferably the openings in the port ring are fixed. However the provision of the variable openings in the port ring is not excluded. If the openings in the port ring were variable (for example to change their length) the embodiment is to be regarded as being in accordance with the invention if there is one working configuration in which a definition of the present invention is satisfied. The fact that there may be other configurations in which definitions of the invention are not satisfied is not material.
[0028] In accordance with a second aspect of the present invention there is provided a pulveriser mill having a rotatable grinding ring, and a rotatable port ring around the circumference of the grinding ring, wherein the port ring defines, around its 360 degree extent, a plurality of openings which are separated by lands, the openings permitting air to flow from beneath the grinding ring to above the grinding ring and the lands serving as obstructions to the flow of air from beneath the grinding ring to above the grinding ring, wherein the lands occupy from 90 degrees to 280 degrees of the 360 degree extent of the port ring.
[0029] In this second aspect the aspect ratio of the openings may be as defined above in the first aspect.
[0030] Preferred features of the second aspect are the preferred features of the first aspect, as stated above.
[0031] In one embodiment additional, variable, openings are provided; that is, additional to the openings in the port ring (whether themselves variable or, as is preferred, fixed).
[0032] Preferably each variable opening is closable. Preferably each variable opening has a fully open condition and a fully closed condition. Preferably each variable opening has at least one condition in between, and preferably a plurality, more preferably a continuum, of conditions in between.
[0033] Preferably each variable opening is associated with a closure or blanking part which may be moved so as to change the condition of the variable opening. Preferably each closure part is slid over or under its opening, to change the effective area of the opening. Preferably the variable openings are provided in an annular part which is U-shaped in cross-section, and the closure part is an annular part which is U-shaped in cross-section, nested against (preferably nested beneath), and supported in rotation by, the annular part containing the variable openings. There may be one such closure part or more than one, defining segments of the periphery of the grinding ring.
[0034] The or each closure part may be controlled from outside the mill. Suitably this may be done as a pulveriser operation is under way. The or each closure part may be moved by means of a control member, for example a lever, push-pull member, worm and wheel, or rack and pinion gear, the rack being connected to the closure part and the pinion being connected to a control member, for example a control wheel or handle, or control wheels or handles, on the outside of the mill.
[0035] The movement of the closure part(s) could be powered by mechanical, electrical, pneumatic or hydraulic means.
[0036] Preferably a plurality of variable openings is under the control of a common control member.
[0037] Preferably each variable opening is provided on a wider radius than the openings in the port ring. Preferably there is present a mill liner outside the openings in the port ring, and the or each variable opening is provided in the mill liner. As mentioned above the mill liner is typically a downwardly slanted metal annulus carried on the inside wall of the mill.
[0038] Preferably each variable opening is rectangular, or is arcuate, and follows the curvature of the mill.
[0039] Preferably the variable openings are in an array in the hoop direction; each opening preferably being an arc of a circle, centered on the axis of the mill.
[0040] Preferably adjacent variable openings are separated in the hoop direction by a land at least as long as the openings; preferably at least 1.1 times as long; and preferably up to 2 times as long. Thus the variable openings preferably occupy less than 180 degrees of the extent of the 360 degree extent of the mill; and preferably occupy 60 to 160 degrees thereof.
[0041] The variable openings can be arranged evenly around the 360 degree extent of the mill, or can be arranged in groups. For example they may be arranged in three groups, the groups being separated by long lands. With certain mills, which have fixed grinding rings, it is not necessary to provide variable openings in the region of the grinding rings; only in the regions between the grinding rings.
[0042] Preferably the area of the variable openings, when fully open, is at least 10% of the area of the port ring openings (with the latter fully open, when they themselves are variable); preferably at least 20%, preferably at least 30% and most preferably at least 40%.
[0043] Preferably the area of the variable openings, when fully open, is up to 200% of the area of the port ring openings (with the latter fully open, when they themselves are variable), preferably up to 100%, more preferably up to 75%, most preferably up to 60%.
[0044] Thus, preferably when variable openings are present they provide, when fully open, from 40 to 60% of the area of the openings in the port ring (with the latter fully open, when they themselves are variable).
[0045] The openings in the port ring preferably together provide the major air flow area in the present invention. Additionally there is air flow through the running clearance. The variable openings, when present, are suitably intended for “trimming” the performance.
[0046] The provision of variable openings, when present, does not mean that the openings in the port ring must be made narrower.
[0047] Reduction in area of the port ring openings may be desirable but can be achieved by employing a design of port ring with somewhat longer lands, and corresponding shorter openings; and/or by reducing the running clearance.
[0048] It is a limitation of the existing mill designs described herein that when there is a need to change coal throughput, air speed must be changed in order to maintain the correct air-coal ratio, and hence the optimal velocity in the mill. When the air velocity is simply increased, as may happen in existing mills, there is an increased tendency to lift large pieces of mineral, and to advance them to the combustion apparatus. On the other hand when the air velocity is too low there is an adverse effect on the coal particle size distribution in the ground material advanced to the combustion apparatus, and consequently poor combustion. The provision of variable openings as a preferred aspect of the present invention substantially improves mill operation by permitting air velocity to be held within suitable limits, even when there are large changes in throughput.
[0049] The variable openings may be adjusted to vary the air flow rate (i.e. to allow more, or less, air to flow in a given time), but still at a desired air speed.
[0050] Operating the mill with the variable opening(s) partly open or open to the maximum extent reduces the requirement to increase the air speed.
[0051] Preferably the air speed is kept substantially constant (e.g. ±20% of the mid-value, preferably ±10%) during the method.
[0052] In accordance with a third aspect of the present invention there is provided a method of improving an existing pulveriser mill which has a rotatable port ring located around the circumference of a rotatable grinding ring of the mill (the port ring preferably being mounted on the grinding ring for common rotation therewith), the port ring having a plurality of spaced-apart vanes having upper and lower ends, defining openings separated by the through-thickness of the vanes, and the mill having a mill liner mounted to the wall of the mill around the port ring; wherein the method comprises: the replacement of said port ring by a second port ring having wider openings, said wider openings being separated by lands; and the narrowing of the mill liner, or the replacement of the mill liner by a narrower mill liner, or the removal of the mill liner without replacement.
[0053] Preferred features of the third aspect are any of the features defined as being necessary or desirable features of the first or second aspects.
[0054] In accordance with a fourth aspect of the present invention there is provided a method of operating a mill of the present invention as defined above.
BRIEF DESCRIPTION OF THE FIGURES
[0055] The invention will now be further described, by way of example, with reference to the accompanying drawings, in which:
[0056] FIG. 1 is a schematic side sectional view of the grinding part of a known pulveriser mill, in operational condition;
[0057] FIG. 2 is a schematic expanded side sectional view of a side region of a similar known pulveriser mill;
[0058] FIG. 3 is a plan view from above of the region shown in FIG. 2 ;
[0059] FIG. 4 is a schematic drawing showing the arrangement of vanes and openings, in the region shown in FIGS. 2 and 3 ;
[0060] FIG. 5 is a plan view from above of a peripheral region of a mill, illustrating the invention;
[0061] FIG. 6 is a side sectional view of a region of the mill also shown in FIG. 5 , showing the arrangement of lands and openings, illustrating the invention;
[0062] FIG. 7 is a side section view of an edge region of a mill, illustrating the invention, in a second embodiment; and
[0063] FIGS. 8A-8C are plan views, showing the side region of the second embodiment in different stages of operation.
DETAILED DESCRIPTION OF THE INVENTION
[0064] FIGS. 1-4 show a prior pulveriser mill generally in accordance with EP 507983A. The mill has a driven, lower steel grinding ring 2 (which is alternatively called a grinding member, or a grinding wheel, in this art). Grinding ring 2 has an upwardly-facing annular groove 4 , in which a plurality of grinding elements 6 , e.g. steel rollers or balls, are located. Above the grinding elements is located a fixed (non-rotating) steel top ring 8 , which has a downwardly-facing annular groove 10 , aligned with the annular groove 4 of the grinding ring 2 . Therefore the arrangement is like a ball race, with the grinding elements 6 free to precess within the oppositely-directed grooves 4 , 10 .
[0065] This type of pulveriser mill is used in a highly demanding environment, to crush coal into fines (powder) to be combusted. The coal fines are carried upwardly by an air current, towards the combustion apparatus.
[0066] Around the grinding ring 2 is a narrow throat 22 and in the throat 22 there is provided a port ring 24 ( FIG. 2 ). This rotates as one with the grinding ring 2 , to impart a desired movement to the upwardly-directed air, which carries the coal fines to the combustion apparatus.
[0067] The port ring 24 comprises a plurality of spaced-apart vanes 26 . The vanes 26 are welded between spaced-apart support rings 28 and 30 which are inner and outer circumferential walls of the port ring. Preferably the inner and outer support rings 28 , 30 of the port ring 24 are short sections of vertical concentric cylinders. The vanes 26 are inclined. The angle of inclination of the vanes is in the range of 20 degrees to 40 degrees from vertical. Preferably the angle of inclination is 25-30 degrees. The upper ends of the vanes are tilted in a direction opposite to the direction of normal rotation of the grinding ring (that is to say, the tilt of the vanes is such that the upper ends trail the lower ends when the grinding ring is rotated). In FIG. 3 the top edge of a vane is indicated as 26 a; 26 b denotes the projection of the inclined frontal face of a vane, visible from, above due to the inclination of the vane; and the lower edge of a vane is indicated as 26 c. Inner support ring 28 may be secured to the periphery of the grinding ring by means of bolts 32 or by welding, for example.
[0068] An annular mill liner 34 extends downwardly from the inside wall 35 of the mill body, to which it is preferably secured, towards the upper and outer edge of the port ring. Then the mill liner extends vertically downwardly to within about 1 cm of the upper edge of the outer member 30 of the port ring. The angle of inclination of the mill liner is typically between 30 degrees and 60 degrees, to the wall of the mill body (i.e. to the vertical).
[0069] Particles produced by the crushing or pulverising process are carried upwardly by means of air passing through the port ring 22 . Air flows upwardly in a nearly vertical manner with minimal swirling or spinning. As a result, the crushed particles are lifted upwardly in a smooth and efficient manner.
[0070] The invention will now be described, by way of example, with reference to the first embodiment of the invention, illustrated in FIGS. 5 and 6 .
[0071] The overall arrangement is similar to that described with reference to FIGS. 1-4 , in its grinding apparatus, and in that a rotating port ring is provided. Like the port ring described with reference to FIGS. 1-4 , the port ring 124 has a series of vanes 126 , mounted to the grinding ring (not shown) at its circumference. The vanes are mounted and inclined as described above, except that they are not evenly spaced. Each vane is welded in place such that the space 140 to one side of it is longer, in the hoop direction, than the space 142 on the other side of it. The longer spaces 140 are blanked off by blanking plates or lands 144 , welded to the upper edges of the respective vanes 126 , and to the upper edges of the support rings 128 and 130 , over the spaces 140 . Thus, only the other spaces 142 , forming fixed openings or ports, and defined by the more closely spaced vanes, are available for the through-flow of air. In this embodiment the ratio of the lengths of these spaces in the hoop direction (space 140 to space 142 ) is approximately 1.5 to 1. It will be apparent that more than one-half (in fact, about 215 degrees) of the annular extent of the port ring 124 has been rendered unavailable for air flow—see FIG. 6 (about 145 degrees of the annular extent therefore being available for air flow).
[0072] A running clearance 145 is provided between the port ring 124 and the mill liner 134 . The running clearance and the openings 142 together constitute the whole of the area available for air flow.
[0073] It is highly desirable to keep air speed at an optimum level and, at least approximately, to maintain the available area for the throughput of air. To achieve this the port ring 124 is made wider than has heretofore been the case--for example wider than the port ring shown in FIGS. 1 to 4 . The port ring, and in particular the openings in the port ring, are approximately 2.5 times as wide as they would have been, had the lands not been used, in this embodiment.
[0074] The result is a port ring which no longer provides a narrow throat obtruded only by the through-thicknesses of the vanes; it is a port ring which is considerably wider than it would otherwise have been, but with alternate openings covered by lands 144 . The summated area thereby provided for flow-through of air is thus similar, for the mill of the present invention and the prior mill having a narrower port ring without lands. This means that large pieces of unground spoil, such as rock, can fall through the port ring of FIGS. 5 and 6 , and back into material to be fed into the grinding zone, or into scrap, instead of accumulating on the port ring, as would have happened before.
[0075] The widening of the port ring may be accommodated by the mill liner 134 . When an existing mill, having a mill liner, is modified, the mill liner may be narrowed in-situ by removing a portion thereof in the mill; or the original mill liner may be removed and a narrower mill liner fitted in its place; or, in some cases, the mill liner may simply be removed, without being replaced. When a port ring/mill liner assembly is being fitted for the first time (either to an existing mill without a mill liner or as part of a newly constructed mill), a wide port ring and a narrow liner may be used (relative to the port ring and liner which would previously have been used).
[0076] The invention will now be described, by way of example, with reference to the second embodiment shown in FIGS. 7 and 8 A- 8 C.
[0077] The overall arrangement is similar to that described with reference to FIGS. 1-4 , in its grinding apparatus, and in that a rotating port ring is provided. Like the port ring described with reference to FIGS. 5 and 6 , the port ring 224 is mounted to the grinding ring 200 at its circumference, and has a series of fixed openings 240 , each pair of adjacent openings being separated by a land 244 , with each land spanning a pair of vanes 226 and completely closing what would otherwise have been further openings. A running clearance 245 is shown between the port ring 224 and the inclined mill liner 234 . The running clearance and the fixed openings together constitute the fixed area available for air flow. However it will be seen that in this embodiment the mill liner 234 is no longer a plain non-apertured annular sheet but has a series of spaced-apart, additional openings 250 , arranged in an annular array. Each opening is an elongate rectangle (but in another embodiment could be an arc, with the arcs being in a circular array, following the shape of the mill liner 234 .
[0078] A movable blanking part 252 beneath the mill liner has openings 253 which may be moved into register with the respective openings 250 in order to completely close them (see FIG. 8C ); or may be moved totally out of register with the respective openings in order to fully open them (see FIG. 8A ); or may be moved to any position in between (see FIG. 8B ). Blanking part 252 is a sector of a ring extending around the mill, close to the side wall, beneath the mill liner 234 . It has a shape which closely conforms to the shape of the mill liner 234 . It has vertical side walls 254 which are supported by bearers 256 .
[0079] In the embodiment of FIGS. 7 and 8 A- 8 C the arrangement of variable openings 250 in the mill liner is even all the way around the mill liner.
[0080] In this embodiment the movement to control the variable openings 250 occurs under mechanical control. A single control wheel 258 is mounted to the outside wall 260 of the mill. The wheel 258 is coupled to a shaft 262 which passes through the wall 260 , and carries a pinion gear 264 . The pinion gear is in mesh with a rack 266 shown schematically in FIGS. 8A-8C . The rack is mounted to a blanking part which has wheels (not shown) and which is mounted on a support track (not shown) such that turning the wheel 258 advances or draws back an annular band to bring each opening 250 to the same condition. By means of the simple common control it is assured that the air mass flow conditions around the mill are the same. It would be undesirable in this embodiment if certain openings were shut when others were open.
[0081] In this second embodiment the summation of the area of the variable openings 250 when fully open is approximately 50% of the summation of the area of the fixed openings 240 in the port ring 224 and of the running clearance 245 between the port ring 224 and the mill liner 234 .
[0082] Provision of the variable openings 250 means that air speed may be kept at an optimum level across a wide range of airflow rates, and mass transfer rates.
[0083] In this second embodiment nested, generally U-section, parts the mill liner 234 and the blanking part 252 are provided. The mill liner is fixed and the blanking part is movable, to open/close the variable apertures 250 . The blanking part 252 is advanced or retarded by a spur wheel and rack arrangement. In alternative embodiments these could be any of a number of arrangements, for example other mechanical arrangements e.g. worm and wheel; pneumatic apparatus; hydraulic apparatus; and electrical apparatus; in each case preferably controlled from outside the mill. | A pulveriser mill having a rotatable grinding ring and a rotatable port ring around the circumference of the grinding ring co-rotatable therewith, the port ring defining around its 360 degree extent a plurality of openings separated by lands, the openings permitting air to flow from beneath the grinding ring to above the grinding ring, and the lands serving as obstructions to the flow of air from beneath the grinding ring to above the grinding ring, wherein the aspect ratio of the openings is in the range from 1:1 to 3:1. | 8 |
[0001] This application is a continuation-in-part of U.S. patent application Ser. No. 10/974,848 filed Oct. 28, 2004, which is a continuation-in-part of U.S. patent application Ser. No. 09/832,979, filed Apr. 12, 2001, which claims the benefit of U.S. Patent Application Ser. No. 60/196,301, filed Apr. 12, 2000.
FIELD OF THE INVENTION
[0002] The present invention relates to a system and method for preventing unauthorized use and/or access to a building and vehicle and more particularly, the present invention relates to a device that provides owners and authorized users varying degrees of control over their vehicle including its theft prevention, particularly for constantly running vehicles such as a fire truck.
BACKGROUND OF THE INVENTION
[0003] Generally speaking, the theft of vehicles such as snowmobiles, ATVs, watercrafts, motorcycles and other vehicles having a magneto/stator present in the motor system, including most non jet propulsion aircraft, is fairly straightforward, much to the demise of the owners of such vehicles. This is also a problem for automobiles despite the fact that they do not include a magneto or stator.
[0004] The simplicity in, for example, starting the motors of these vehicles is realized by the arrangements used to link the ignition system to the ignition generator coil. In snowmobiles, for example, the block connectors electrically connect the ignition switch, kill switch and power accessories to the ignition switch. These elements are all exposed outwardly of the motor. To the skilled thief, since these elements are readily accessible, bypass is simple and can typically be achieved in seconds. The result is that the vehicle can be easily started and driven away with ease and with a minimum of effort.
[0005] In an attempt to speak to the escalation in theft of these vehicles, many devices have been proposed in the art which attempt to provide the user/owner with a greater degree of security. The arrangements known incorporate alarms, keylock systems, manual circuit interrupts inter alia. These devices, although somewhat useful, are all limited by the same vulnerability, namely the fact that they are external systems which are accessible by a thief and therefore are easily disabled by bypass or “hot wiring”.
[0006] In the case of snowmobiles, track locks have been proposed. These devices are simply not pragmatic; the user is confined to carrying these bulky awkward items on the snowmobile which requires storage space. This space is often at a premium in view of the size of the snowmobile.
[0007] A current manufacturer has offered a digital system (for selected models) and even though its method has a level of effectiveness, it is still vulnerable by its external application. Accordingly, the owner of earlier model vehicles is not helped by the new technology.
[0008] Other systems for preventing theft of watercraft include markings on the craft itself or special indications on the hull identification plate. These attempts at preventing theft can be easily circumvented by simply removing and replacing the plates or altering the information thereon.
[0009] In terms of automobiles, steering wheel arrangements such as the Club™ are typically employed. These devices are somewhat useful, but are easily removable by determined thieves.
[0010] Immobilizers are also used in automobiles for theft prevention, but are limited by their external disposition.
[0011] Perhaps one of the most difficult situations relates to constantly running vehicles or emergency vehicles. These are highly vulnerable to theft, since the driver, once the vehicle is parked, for example, is preoccupied and therefore not cognizant of unscrupulous activity. These conditions make theft trivial to complete. In situations as noted above, it would be useful if the vehicle could receive information updates concerning a patient or situation available to the driver (user) upon his return to the vehicle. Further, it would be advantageous, in the fire fighting scenario, where the firemen could access an adjacent building with a smart card without having to damage the building or risk loss of the fire truck through theft. The present invention seeks to amalgamate present needs for security with available technology in a previously uncombined and novel manner.
[0012] In view of the fact that the vehicles are expensive, a more sophisticated method and apparatus is required which is not external of the motor or engine and which does not employ interceptable digital streams.
[0013] The present invention addresses this need and thus one object of one embodiment of the present invention is to provide a control device mounted internally of the engine. This renders control of operation of the vehicle inaccessible to tampering.
SUMMARY OF THE INVENTION
[0014] One object of the present invention is to provide an improved apparatus and method for preventing unauthorized use of and ultimately the control of a vehicle.
[0015] A further object of the present invention is to provide a system for preventing unauthorized use of a vehicle having an engine housing and means for enabling starting of said engine, comprising, in combination a wireless smart card reader, a smart card for reading by said smart card reader, a circuit for disabling operation of said vehicle operatively connected to said smart card reader, comprising an interrupt circuit electronically connected to said means for enabling starting of said vehicle, said circuit for selectively interrupting said means for enabling starting of said vehicle, said circuit being mounted directly within said engine housing, switch means mounted within said engine housing and connected to said circuit for allowing interruption to said means for enabling starting of said vehicle, said switch means responsive to communication with said wireless smart card reader and battery connecting means for connecting said wireless smart card reader to the battery of a vehicle engine responsive to signals from said wireless smart card reader.
[0016] As a particular convenience, the switch means may be selected from any suitable switching devices, such as mechanical, electrical, electro-mechanical, electronic (digital) arrangements. The important feature is that the circuit (supra) is positioned within the housing as opposed to externally; this latter arrangement is what limited the effectiveness of the prior art.
[0017] Another object of one embodiment of the present invention is to provide a smart card based security system for preventing unauthorized use of a vehicle and unauthorized communication with a building, said system, comprising a vehicle wireless smart card reader connected within said vehicle, a building wireless smart card reader for permitting communication with said building, a smart card for communication with the readers, a circuit for disabling operation of said vehicle operatively connected to said smart card reader, comprising an interrupt circuit electronically connected to said means for enabling starting of said vehicle, said circuit for selectively interrupting said means for enabling starting of said vehicle, said circuit being mounted directly within said engine housing switch means mounted within said engine housing and connected to said circuit for allowing interruption to said means for enabling starting of said vehicle, said switch means responsive to communication with at least one of said wireless smart card reader and said building wireless smart card reader, and battery connecting means for connecting said wireless smart card reader to the battery of a vehicle engine responsive to signals from said wireless smart card reader, whereby said system is capable of data conveyance between said vehicle and said building.
[0018] The mounting location for the circuit is conveniently anywhere within the housing with a suitable connection to the ignition generator coil. As an example of a useful position, the circuit may be positioned between the stator and magneto.
[0019] A still further object of one embodiment of the present invention is to provide a method for preventing unauthorized use of a vehicle having an engine housing and means for enabling starting of said engine, comprising providing said vehicle with a wireless smart card reader, providing a smart card for reading by said smart card reader, providing a circuit for disabling operation of said vehicle operatively connected to said smart card reader, comprising, an interrupt circuit electronically connected to said means for enabling starting of said vehicle, said circuit for selectively interrupting said means for enabling starting of said vehicle, said circuit being mounted directly within said engine housing, switch means mounted within said engine housing and connected to said circuit for allowing interruption to said means for enabling starting of said vehicle, said switch means responsive to communication with said wireless smart card reader; and battery connecting means for connecting said wireless smart card reader to the battery of a vehicle engine responsive to signals from said wireless smart card reader, and contacting said smart card in proximity with said switch means to effect an enabled start of said vehicle.
[0020] The transceiver arrangement facilitates communication between the vehicle and other extraneous communication devices such as satellite systems, computers, web enabled cellular phones, GPS, personal digital assistants (PDA) or any other suitable device or combination of devices useful for communication.
[0021] The transceiver system can be used to control operation of the ignition generator, engine rpm, air/fuel mixture inter alia.
[0022] The provision for GPS capacity allows for tracking of the vehicle in the event it is stolen.
[0023] As a further object of one embodiment of the present invention, there is provided a method for preventing unauthorized use of a vehicle and unauthorized communication with a building based on a smart card platform security system, comprising providing a vehicle wireless smart card reader connected within said vehicle, providing a building wireless smart card reader for permitting communication with said building, a smart card for communication with the readers, providing a circuit for disabling operation of said vehicle operatively connected to said smart card reader, comprising an interrupt circuit electronically connected to said means for enabling starting of said vehicle, said circuit for selectively interrupting said means for enabling starting of said vehicle, said circuit being mounted directly within said engine housing, switch means mounted within said engine housing and connected to said circuit for allowing interruption to said means for enabling starting of said vehicle, said switch means responsive to communication with at least one of said wireless smart card reader and said building wireless smart card reader, and battery connecting means for connecting said wireless smart card reader to the battery of a vehicle engine responsive to signals from said wireless smart card reader, whereby said data conveyance between a vehicle point and a building point, a user point and said vehicle point, said user point and said building point and said vehicle point and said building point is effected wirelessly through said readers and said card to prevent illegitimate activity through the points.
[0024] A still further of object of one embodiment of the present invention is to provide a method for controlling vehicle function, operation and unauthorized use of said vehicle having an engine and block therefor, sensors for effecting engine activation and other functions, a power source, ignition coils, and means for establishing communication between said sensor and said coils, said method comprising the steps of providing switch means for and augmenting communication to and/or from said sensors for altering function of said sensors, providing wireless transceiver means connected to said switch means for receiving electromagnetic signals from a signal service provider and transmitting electromagnetic signals to said signal service provider, said switch means being actuable by said transceiver means, positioning said switch means and said transceiver means between at least one sensor of said sensors and said means for establishing communication between said sensors and said coils, mounting said switch means and said transceiver means to said at least one sensor, and activating said switch means by said transceiver means for communicating with said sensors for altering engine activation and other functions.
[0025] The means for establishing electrical communication between the sensors and coils is known in the art as an ECM motherboard. In current arrangements, the ECM motherboard in automobiles is externally mounted of the engine and thus is vulnerable to tampering. If removed and replaced with a similar component not equipped with a theft deterrent (immobilizer) auto theft is easily achieved.
[0026] By providing the switch arrangement and mounting location, the presence of an immobilized ECM motherboard is of no consequence; the arrangement discussed supra interrupts power to the sensors leading to the ECM motherboard and further is mounted at least partially within the engine block to avoid tampering, bypass or expeditious removal. The ECM may also be mounted internally.
[0027] As a particularly attractive advantage, the switch means may be integrally mounted to the sensor or a plurality of sensors. By providing several such switches, security for preventing unauthorized access may be augmented.
[0028] Further still, the smart card used in the present invention may be remotely updated with further information at any time. The information may be specific to one user to provide limited access to a building or other property as an example. Obviously, the system can operate on a network to alter many cards at one time. Broadly, examples of smart cards are known; the HID Company presently provides such cards. Although this is the case, the unification of a vehicle disabling circuit and building access provision has not been previously proposed.
[0029] It will be readily apparent to those skilled that the vehicles having stator/magneto arrangements could easily be adopted to the circuit mentioned above where the stator/magneto is removed in future modifications of such vehicles.
[0030] Having thus described the invention, reference will now be made to the accompanying drawings illustrating preferred embodiments.
BRIEF DESCRIPTION OF THE DRAWINGS
[0031] FIG. 1 is a perspective view of a typical engine of the vehicles set forth herein;
[0032] FIG. 2 is a view similar to FIG. 1 with the cover removed from the stator housing;
[0033] FIG. 3 is a schematic diagram of the wiring of a typical snowmobile;
[0034] FIG. 4 is a view similar to FIG. 2 with the arrangement according to one embodiment installed;
[0035] FIG. 5 is an abbreviated schematic diagram illustrating the positioning of the elements according to one embodiment of the present invention.
[0036] FIG. 6 is a schematic diagram of the starting circuit for an automobile with the switch;
[0037] FIG. 7 is a schematic illustration of a vehicle and positioning of various sensors; and
[0038] FIG. 8 is a schematic diagram of the switch arrangement in relation to the sensor(s) and ECM motherboard.
[0039] FIG. 9 is a schematic illustration of a vehicle and positioning of sensors.
[0040] FIG. 10 is a schematic diagram of the switch arrangement in relation to the sensors and ECM motherboard.
[0041] FIG. 11 is a schematic illustration of another embodiment.
[0042] FIG. 12 is a schematic illustration of another embodiment.
[0043] FIG. 13 is a schematic illustration of another embodiment.
[0044] FIG. 14 is a schematic illustration of an embodiment of the present invention incorporating smart card technology; and
[0045] FIG. 15 is a further embodiment of FIG. 14 .
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0046] Referring now to the drawings and particularly FIG. 1 , numeral 10 generally references the engine. There is provided a housing 12 for housing the magneto and stator. A cover 14 is fixed by fasteners 16 to provide a sealed stator/magneto housing. As is generally known, specialized tools and skill are required to remove the cover 14 and eventually gain access to the interior of the housing 12 .
[0047] FIG. 2 illustrates the interior of the housing 12 where there are mounted several coils 18 , shown in the example as a quantity of five. A main coil or ignition generator coil 20 is also provided and is integral in starting the engine. It is known that such coils generally operate on the principle of sensors. Coil 20 has two leads 22 and 24 which terminate at a block connector 26 . Block connector 26 also includes leads, generally referenced by numeral 28 , leading to the CDI box (not shown). A mating block connector 30 connects to block connector 26 and the former provides leads to the ignition switch, kill switch and power accessories (none of which is shown) of the vehicle (not shown).
[0048] The arrangement is generally well known in the art. Unfortunately, it is also well known that by simply disconnecting the block connectors 26 and 30 , all security systems typically associated with the vehicle are disabled while a signal is still capable of being supplied to the CDI box from the ignition generator coil 20 . Accordingly, the vehicle will start in this condition.
[0049] FIG. 3 illustrates a typical schematic diagram for a conventional snowmobile, although the diagram is applicable to typical magneto/stator motors. As the diagram illustrates, the disposition of the ignition generator coil 20 in the circuit facilitates easy starting of the engine when the block connectors 26 and 30 are disconnected.
[0050] FIG. 4 illustrates an example of the invention as positioned within the housing 12 . A switch 32 is disposed in housing 12 and in this case is an electrical/mechanical switch. FIG. 5 illustrates a truncated schematic of the circuit of FIG. 4 showing the positioning of the switch 32 and its relationship to ignition generator coil 20 . As illustrated, the switch 32 includes leads 34 and 36 , with lead 34 being connected to ignition generator coil 20 and lead 36 extending to other electrical connections related to starting the vehicle. By connection to ignition generator coil 20 , the circuit is interrupted in the OFF position and is unaffected by disconnection of block connectors 26 and 30 . Accordingly, the user, in order to start the vehicle must initially actuate the switch 32 into the ON position with, for example, a key 38 which, in turn, will re-enable the ignition generator coil 20 . Once this is done, normal procedures may be performed to start the vehicle.
[0051] In the embodiment of FIG. 5 , a switch is mounted in the housing 12 adjacent the ignition generator coil 20 . Trigger coils are reverenced by numeral 20 ′. This is not essential. In the situation where the switch system comprises a remotely controllable arrangement, the switch may be replaced by a receiver (not shown) well known in the art. In these devices an antenna can be positioned in any convenient location provided it can communicate with a transmitter (not shown). It will be appreciated to those skilled in the art that any suitable switch capable of selectively interrupting the ignition generator coil circuit may be used.
[0052] Advantageously, by positioning the circuit interrupt portion of the switch within the housing, tampering or bypass is difficult, tedious and would more than likely damage the vehicle if a thief attempted any tampering. Further, if the switch mechanism is damaged, broken or removed, the vehicle cannot be made to start unless original wiring is restored. Cover 14 is removed and the switch 32 removed from the vehicle. This is obviously time consuming and cannot be performed with any degree of stealth.
[0053] FIG. 6 illustrates a further embodiment of the overall concept of the invention. In this embodiment, the engine housing 12 is shown the ignition generator coil 20 connected to the switch means 32 and the circuit positioned within housing 12 . As illustrated, this circuit is electrically connected to a CDI box, referenced in this figure by number 18 . The CDI module 18 is, in turn, electrically connected to the additional coils as well as a power supply (not shown) as is well known. As a further variation of FIG. 6 , the dashed line represented by numeral 12 ′ constitutes the engine housing 12 , but accommodates a trigger coil 52 , which trigger coil 52 communicates electrically with switch means 32 and subsequently to CDI module 18 . This is a variation where the trigger coil 52 , switch means 32 and CDI module 18 are electrically connected for interruption. This provides an alternative to the ignition generator coil 20 , switch means 32 and CDI module 18 combination.
[0054] As still a further variant, the engine housing represented by the extended chain line 12 ″ may also include the CDI module 50 such that the CDI module 50 , switch 32 and ignition generator coil 20 as well as trigger coil 52 are all positioned within the engine housing.
[0055] FIG. 7 illustrates a further variation where the electrical communication between switch means 32 and ignition coils, referenced as 52 ′, is interrupted by CDI 18 .
[0056] The point in the further variations is to demonstrate the fact that the switch 32 is positioned within the housing and is in one manner or another connected to an essential element required for operation of the engine (not shown). By this provision, theft of the vehicle incorporating the variants outlined in FIG. 6 is substantially averted, since no parts are available outside of the engine compartment for easy removal and or exchange in order to steal the vehicle.
[0057] In FIG. 9 , a vehicle 51 is shown and includes an engine and an engine block, broadly denoted by numeral 54 . As is known, a number of sensors are required to carry out various functions with respect to the operation of the vehicle. In the example, numeral 56 represents a camshaft position sensor, numeral 58 represents a crankshaft position sensor and numerals 56 through 74 represent other sensors, amplifiers, inter alia.
[0058] As is illustrated in FIG. 8 , disposed between engine 54 and sensors 56 through 74 is a switch 80 . The sensors 56 through 74 are in electrical communication with an ECM motherboard 82 which is responsible for numerous functions, the most important of which for purposes of this discussion is communication between the sensors and ignition coils 84 and 86 . As is known, coils 84 and 86 each communicate with cylinders 88 , 90 , 92 , and 94 , respectively.
[0059] By providing power and/or signal interruption via switch 80 to the sensors 56 through 74 , it is inconsequential as to whether the ECM motherboard 82 is equipped with anti-theft provisions such as an immobilizer (not shown). This is a significant advantage since the sensors are effected by the switch 80 as opposed to the ECM motherboard 82 . By effecting the sensors 56 through 74 , the ECM motherboard 82 is also effected. This is a more effective system since it does not matter whether the ECM motherboard includes anti-theft provisions.
[0060] The sensors and particularly those shown in FIG. 8 , i.e., sensors 56 and 58 are typically at least partially mounted within the engine block 54 as is generally depicted in FIG. 9 . By connecting the switch 80 to all or some of the sensors 56 through 74 , the switch is therefore at least partially mounted in the engine block 54 and therefore presents significant difficulty for potential thieves to tamper with the arrangement. This is in marked contrast to the disposition of the ECM motherboard 82 which is easily accessible.
[0061] In this manner, the sensors 52 through 70 and the switch 80 (of which there may be several) can be integrated as a single unit. This arrangement is shown in FIG. 10 where the switch 80 and sensor 56 are unified as a single unit. FIG. 10 also shows in dashed line the possibility of augmenting security by linking various switches and sensors in tandem.
[0062] Referring now to FIG. 11 , shown is a generic illustration which is applicable to either stator magneto arrangements or conventional internal combustion engines. Once again, it is illustrated the switch 32 is positioned within the housing 12 and that any one of the essential elements for engine operation such as the trigger coil 52 camshaft position sensor 56 , crankshaft sensor 58 , CDI module 50 , ECM motherboard 82 and/or fuel/air supply 100 may be connected to the switch internally of housing 12 in order to provide the highest degree of security and therefore the lowest incidents of theft.
[0063] FIG. 12 illustrates a further variation of the arrangement when a transponder 102 is positioned within housing 12 and communicates with ECM motherboard 82 and CDI module 50 .
[0064] FIG. 13 illustrates yet another embodiment of the present invention in which a wireless transceiver is connected to the switch means for interrupting various operations of the vehicle. The interruption circuit has been discussed herein previously; however, in this embodiment the interrupt circuit includes a wireless communication means, such as a wireless transceiver or transponder. The overall union of these two elements is broadly denoted in FIG. 13 and represented by numeral 120 . As referenced with respect to FIG. 9 , the sensors 56 and 58 are in direct electrical communication with the interrupt circuit modified with the wireless transceiver.
[0065] By this arrangement, wireless communication is effected with the vehicle and in view of the fact that the interrupt circuit includes a wireless arrangement with sensors at least partially mounted within the engine housing 12 , all of the advantages realized with respect to the difficulty in removal of the arrangement are immediately realized. This is not the case with existing wireless arrangements, such as, for example, the On Star™ system. The On Star™ system is very useful, however, it can be tampered with and even removed entirely from the engine compartment in view of the fact that the arrangement is not at least partially mounted within the engine housing. By incorporating the desirable features of the circuit discussed herein previously and augmenting the system with a wireless transceiver, all of the limitations of externally mounted wireless systems are overcome. As will be appreciated, this is particularly useful for tracking a stolen vehicle or, in extreme situations where the vehicle has been “chopped” the engine can be located by the wireless transponder.
[0066] In order to facilitate communication with the vehicle, the conventional system for wireless communications may be employed. This includes the satellites, one of which is shown in FIG. 13 denoted by numeral 122 which can communicate with a land based tower 124 for receiving and transmitting signals to the wireless arrangement 120 in engine housing 12 as well as a portable communication device 126 , shown in the example as a laptop computer. It will be appreciated that other communication devices such as a web enabled cell phone, personal digital assistant or any other portable or permanent wireless communication device. This allows communication from land based systems such as the On Star™ with the tower and/or the individual circuit in the engine housing 12 . This is useful to control engine functions such as specific engine operations, and is useful to perform diagnostics on the engine and convey this information to a user of the vehicle by way of a stereo system within the vehicle (both of which are not shown) or by other means such as a user's cellular phone (not shown).
[0067] It will also be appreciated that all of the functions that are presently available by wireless communication can be realized with the instant invention such as vehicle tracking, performance and other factors. It will be evident that any of the existing wireless networks can be employed with the system with the simple modification of a specifically tuned transponder/transceiver.
[0068] Although embodiments of the invention have been described above, it is not limited thereto and it will be apparent to those skilled in the art that numerous modifications form part of the present invention insofar as they do not depart from the spirit, nature and scope of the claimed and described invention.
[0069] Turning to FIG. 14 , numeral 150 is globally representative of a further system for use in the present invention. In the schematic illustration, a wireless smart card reader is denoted by numeral 152 which reader can be positioned within a vehicle (not shown) at any particularly convenient location. The card reader 152 is electrically linked to the ignition system of a vehicle (not shown) and globally denoted by numeral 154 as well as the vehicle battery (not shown) and globally denoted by numeral 156 . In the embodiment shown, an optional feature is a display console 158 which could be directly connected to the wireless smart card reader 152 .
[0070] As generally referenced herein previously, the wireless smart card reader 152 is electrically connected to the vehicle disabling circuit, globally referenced in the example by numeral 160 . This disabling circuit 160 is the circuit that has been discussed extensively throughout the text herein supra. The vehicle disabling circuit 160 is one possible node; it is contemplated that other vehicle operating devices could be linked to the wireless card reader. This is referenced by the numerals 162 and 164 . Numerals 162 and 164 are representative of modules that are linked to the wireless reader 152 . These modules are effectively nodes which are connected to other vehicle functions. In the example, module 162 is indicated to be linked to the fuel pump 166 as well as another vehicle control device, referenced by numeral 168 . In terms of module 164 , the module could be linked to the vehicle starter motor denoted by numeral 170 as well as any other ancillary component to the starter motor or any other vehicle operating device, referenced by numeral 172 in the example. As a further example, the entire disabling circuit 160 may comprise a microprocessor with related supporting components and a semiconductor switch means.
[0071] It has been found that this system is particularly effective, namely the wireless system when combined with the vehicle disabling circuit discussed herein above. A particular advantage flows from the combination and it has been found that in the case of an emergency vehicle to augment the smart card technology with further access to a building is a particular benefit to avoid theft. In the illustration, numeral 174 is representative of a building structure having wireless transmission means 176 attached thereto. In this scenario, where the vehicle is a vehicle that requires constant engine running or is a vehicle where the engine must run and the driver(s) are preoccupied with an emergency situation or other urgent activity, the provision of the wireless access to the vehicle is particularly useful and this is augmented by the combination with a building. In the situation where an emergency were adjacent a hospital or a fire station or any related and authorized partner of such authorities, the use of the wireless means 176 from the building is effective to prevent unauthorized activity, namely theft, of the continuously running vehicle. With the combination of the driver or user having the wireless access, the vehicle is effectively always “disabled” until such time as the user or an authorized party (from a partner building) effects enablement of the vehicle.
[0072] As a further benefit to the arrangement, use of the smart card in the instant arrangement, which card is globally represented by numeral 180 in each of FIGS. 14 and 15 can be a multi-function microprocessor card. Such cards are known to retain information from data received from other wireless devices. In the instant situation, such data could be from the group of kilometer use, fuel use, destination locations, elapsed time at location, individual accessing the vehicle, engine operating parameters (oil pressure, oil temperature, engine temperature), results of engine diagnostics, diagnostic modifications made wirelessly etc., materials received at a destination, building access and information relayed to the network of a destination building, vehicle enablement and/or disablement, inter alia.
[0073] It is contemplated that in order to incorporate such a system with existing vehicles, a bypass and databus interface would be required for inclusion within the circuit (not shown). This facilitates integration of the existing system with pre-existing original security equipment within the vehicle.
[0074] With specific reference to FIG. 15 , shown as a further embodiment of the overall system illustrated in FIG. 14 . In the latter embodiment, the system may include a switch 182 , shown in the example as a seat switch. This system also includes a further node 184 , which node can be linked to transmission control, denoted by numeral 186 or some other ancillary control denoted by numeral 188 . As a further option the system may include an override device 190 to bypass the provisions of the system entirely. In the illustration, as an example when a vehicle is at the scene of an emergency, the engine, as noted previously, must be left running and the transmission is set appropriately to continue providing power for auxiliary demands. When the driver leaves the driver's seat of the vehicle (none of which is shown) the transmission is automatically locked. When the vehicle needs to be moved, the driver must sit in the driver's seat and place the smart card 180 within the vicinity of the reader 152 . The user has the correct authority, the transmission will unlock and the vehicle will be available for use.
[0075] In terms of the override device 190 , this could be installed in a location that will bypass the module or node 184 which is connected to the transmission. Further, the switch may have further contacts that can be used to notify the system that is has been overridden and this event will be logged. This information can be incorporated into the smart card as noted previously. When the system is disabled this can be indicated on the reader by an appropriate signal, i.e., an audible signal or a visual signal.
[0076] Although not shown, it is well within the purview of instant technology to provide a plurality of wireless cards 180 and a plurality wireless readers 152 . The examples shown are representative and multiple levels of the system can be linked to accommodate a variety of vehicles and buildings.
[0077] The embodiment(s) of the invention described above is (are) intended to be exemplary only. The scope of the invention is therefore intended to be limited solely by the scope of the appended claims. | A system for preventing unauthorised use of a vehicle having an engine housing and a device for enabling starting of the engine amongst other ancillary features is disclosed. The system provides a wireless smart card reader and a smart card which, may be a multi-function smart card for use with the reader. A circuit is provided in the system which disables operation of the vehicle. The circuit is integrated for electrical disablement by the smart card reader. The circuit includes an interrupt circuit connected to the device for enabling starting of the vehicle. The circuit is primarily directed to selective interruption. The circuit is positioned directly within the engine housing in order to prevent tampering or any other activity which would render the circuit inoperative or bypassed. As a further feature, the system, provide access to a building and the building can communicate with the wireless card reader associated with a vehicle to effect operation of the vehicle. A method of use accompanies the apparatus. | 1 |
BACKGROUND OF THE INVENTION
This invention relates to a card having a frame which comprises two rigidly supported side walls. The roll components of the card are rotatably supported between the side walls and further, the lickerin, the doffer as well as rolls of the web delivering assembly downstream of the doffer are secured to the lateral faces of the side walls.
In known cards two parallel side walls of cast iron are provided. The frame in such cards consists of these two side walls and the connecting elements arranged therebetween which together with the side walls form a box-like structure. The two oppositely disposed bearings for the stub shafts of the main cylinder are designed as pillow-block bearings and are affixed, for example, by screw connection, to the upper bounding surfaces of the side walls. The pillow-block bearings have to be in exact alignment with one another because of the substantial flywheel moment of the rolls and the required accuracy regarding the spacing between the rolls. For this reason, the upper bounding surfaces of the side walls have to be machined to be completely planar and flush with respect to one another at identical heights. Further, the securing surfaces of the pillow-block bearings have to be machined with precision. Such machining operations involve substantial manufacturing expense. On each side between the pillow-block bearing and the associated radial face of the cylinder there is provided a lateral shield which constitutes a closed, arcuate surface which, in essence, shrouds the radial faces of the cylinder. The structural components extending beyond the external circumference of the lateral shield are exposed to lateral fly. The lateral shield has, in addition to an edge flange, radially extending ribs, the height of which increases from the shield periphery towards the hub. Such an arrangement provides a clearance between the pillow-block bearing and the respective end face of the cylinder. In the intermediate space constituted by this clearance between the side wall of the card frame and the lateral shield underneath the pillow-block bearing, dust may accumulate to a significant extent. Each side wall of the frame shrouds the cylinder only in the zone which extends from the floor to the pillow-block bearing. For this reason, the lateral shield, among others, serves the purpose of supporting particularly those carding organs which are arranged above the pillow-block bearings, such as for example the flexible bends and the support for the flat chains. The manufacture of the above-outlined lateral shields involve substantial expense. It is a further disadvantage of the above-outlined arrangement that the drives for the different carding organs require separate supports and covers. As a result, the known carding machines have pillow-block bearings and lateral shields which have to be separately manufactured and the assembly and mounting of which involves substantial expense; further, the carding organs between the lickerin and the doffer are exposed to lateral fly to a substantial extent.
SUMMARY OF THE INVENTION
It is an object of the invention to provide an improved carding machine from which the above-discussed disadvantages are eliminated and which thus is simpler to manufacture and assemble and which further provides an effective shrouding of the carding organs between the lickerin and the doffer and which makes it possible to provide a common support arrangement for the drive of the individual carding organs.
This object and others to become apparent as the specification progresses, are accomplished by the invention, according to which, briefly stated, the card has a frame including two parallel-spaced, rigidly supported side walls having lateral surfaces, a lickerin and a doffer disposed between the side walls and mounted on the lateral surfaces thereof; and carding organs situated between the lickerin and the doffer. At least some of these carding organs are, with their lateral end faces, disposed immediately adjacent the lateral surface of the respective side wall and are laterally mounted on the side walls.
The invention is founded on the basic consideration to secure the carding organs and structural elements disposed between the lickerin and the doffer, not to the top of the side walls as in the known arrangements, but to the lateral faces of the side walls. Thus, for this purpose, the invention provides that the lateral end faces of the carding organs and structural elements, such as the main cylinder, the flexible bends and the supports for the flats are immediately adjacent the inner lateral faces of the side walls of the card frame and further, the carding organs and structural elements are supported laterally in the side walls.
Thus, according to the invention, the card frame has two side walls made, for example, of steel plates, which are immediately adjoining the carding organs and the carding organs are supported by means of their shafts or mounting elements, on the lateral surfaces of the side walls. Therefore, the expensive pillow-block bearings and lateral shields by means of which heretofore the carding organs had to be mounted on the top of the side walls are dispensed with in the card structured according to the invention. Thus, according to the invention, the side walls are either in part or in their entirety extended upwardly to the height level of the uppermost carding organ. This arrangement, in particular, renders unnecessary the expensive planar machining of the securing faces required heretofore for the pillow-block bearings. This arrangement according to the invention has the further advantage that the locations of support where the carding organs are to be secured on the lateral inner and outer faces of the side walls can be positively determined at the time the side walls are designed and may be provided therein by simple manufacturing operations. Thus, after marking, the apertures for the bearings or bolts may be provided by simply drilling holes through the side walls. This results in a very substantial simplification of production technology, leading to a more economical manufacture of the carding machine. The invention permits a particularly advantageous arrangement of the carding organs with respect to the side walls since, on the one hand, the shafts or securing elements of the carding organs may be directly mounted on the side walls and, on the other hand, the side walls can be arranged immediately adjacent the end faces of the movable or stationary carding organs, whereby dust accumulation and lateral fly can effectively be avoided.
By virtue of the fact that the end faces of the carding organs are arranged immediately adjacent the inner faces of the side walls and thus only a minimum intermediate space is present, maintenance, emptying and cleaning of the card are, in addition, significantly simplified and rendered easier. Further, the invention provides that the drives for the moving carding organs are secured externally of the side walls and the side walls serve as a common support for all the drives. As a result, by virtue of the simple arrangement of the side walls with respect to the carding organs, a very substantial simplification of manufacture is coupled with an effective shrouding of the carding organs.
In addition to protecting the cylinder against lateral fly, the side walls, among others, serve for receiving the flexible bends, front and back bends, the adjusting devices for these components as well as the adjusting devices for the cylinder grid, the stationary points for the lickerin and the adjustment for the doffer, the stationary points for the grinding and ejecting device and further serves as connecting component for the feeding organs and the web delivery unit.
The intermediate space between the lateral end faces of the carding organs and the side walls will be particularly narrow if the shaft bearings are mounted (for example by means of a screw connection) on the outer lateral surfaces of the side walls. Advantageously, the bearings for the cylinder are additionally supported, for example, by means of pedestals. In this manner, the substantial axle load of the stub shafts of the cylinder can be taken up in an effective manner.
Preferably, the side walls are steel plates in which reinforcing ribs or struts may be provided. Steel plates are stable, they are economical to manufacture and metal working operations are easy to perform thereon.
Expediently, the side walls of the machine frame are each one-piece components, so that during the prefabrication, all markings and apertures may be provided simultaneously or in a rapid sequence.
According to a preferred embodiment of the invention, however, the side walls are each multi-part components; this significantly simplifies the installation of the carding organs. Each side wall may be so divided that, for example, a lower and an upper wall part surrounds a bearing. Each side wall may also be composed of juxtapositioned wall portions. Such an embodiment makes possible the addition of further side wall portions, so that additional carding organs can be used for processing different types of fibers. Thus, the card may be extended in a simple manner by means of additional structural components and stages.
Expediently, the side walls completely shroud the end faces of the carding organs, for example, they cover the entire lateral face of the cylinder and the traveling flats, ensuring a particularly effective protection. Such shrouding extends from the base plate to the outermost upper limit of the carding organs.
In accordance with a further advantageous feature of the invention, the side walls are held together by additional connecting elements which are designed as auxiliary components for maintaining a fixed distance between the side walls and serve, for example, as clothing, material removal hood, feeding table, fixed flats or guide for traveling flats.
BREIF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic side elevational view of a preferred embodiment of the invention.
FIG. 1a is a schematic side elevational view of a modification of the same embodiment.
FIG. 2 is a schematic side elevational view of another preferred embodiment of the invention.
FIG. 3 is an enlarged front elevational sectional view taken along line III--III of FIG. 1.
FIG. 4 is a front elevational sectional view, on an enlarged scale, of a modified detail of FIG. 3.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Turning now to FIGS. 1, 1a and 3, on a base plate 1 there are arranged vertically oriented, parallel-spaced side walls 2 and 3 each being constituted as a one-piece member extending from the base plate 1 to the upper limits of the card. To the lateral surface of the side walls 2 and 3 there are affixed bearings 4, 5, 6 and 7 for the cylinder 17, the doffer 44, the web delivering assembly (not shown) and the lickerin 43, respectively. The stub shafts of each of these carding organs, journalling in the bearings 4-7, extend through the side walls 2 and 3 through openings provided therein. While, as noted, each side wall 2 and 3 may be entirely a one-piece member, it is expedient if each side wall has, in the zone of the cylinder, a relatively small top portion bounded by parting lines 8 and 9 as illustrated in FIG. 1a. Such an arrangement significantly facilitates the mounting of the cylinder bearing 4. The side walls 2 and 3 may be provided with reinforcing elements such as vertical, spaced ribs 16.
FIG. 2 shows a card in which the two side walls (only one is visible in FIG. 2) arranged on the base plate 1 are each formed of a plurality of side wall portions 10, 11, 12, 13, 14 and 15. The parting lines between the side wall portions 10-15 extend vertically. This embodiment provides that structural units may be positioned side by side or behind one another as modules.
Turning once again to FIG. 3 and also referring to FIG. 4, the main cylinder 17 of the card is rotatably supported between the side walls 2 and 3 which extend from the base plate 1 up to the highest point of the revolving flats. The stub shafts 18 and 19 of the cylinder 17 extend through bores 20 and 21 provided in the side walls 2 and 3 and are supported in bearings 22 and 23 which are mounted (for example, bolted) on the respective outer lateral surface of the side walls 2 and 3. A closure 24 is arranged externally of and spaced from the side wall 2 to define therewith a space in which, for example, a dust removing device may be disposed. At the outer lateral face of the side wall 3, on the other hand, a closure 25 defines a space which accommodates the driving components for the rotary carding organs.
Between each side wall 2 or 3 and the respective lateral end face of the cylinder 17 there are provided disc-like circular flanges 26, 27 which constitute integral parts of the respective side walls 2 and 3. This arrangement provides that the end faces of the cylinder 17 are situated very closely to the side walls 2 and 3. The flanges 26 and 27 extend into a recessed cylindrical space 17a at the end faces of the cylinder 17 and substantially fill out the same. The flanges 26, 27 have central openings through which the stub shafts 18 and 19 of the cylinder 17 extend. Each flange 26 and 27 further has, at its side oriented away from the respective side wall 2 or 3 to which it is attached, annular enlargements 28 and 29 which serve for securing carding organs, such as the cylinder grid 33 and the flexible bends 30 and 31 for the flat bars 32 (only one shown). Above the flexible bends 30 and 31 and the flat bars 32, return bends 34 and 35 which support the flat bars 36 (only one shown) are secured to the side walls 2 and 3, for example, by means of threaded bolts.
Further, referring to FIG. 4, on the base cylinder 1, in a face-to-face relationship therewith, there is positioned a support plate 38 with the interposition of a cylindrical rod 37. The side wall 2 is positioned on the support plate 38 in a vertical orientation. The bearing assembly 22 is inserted in a circular aperture of the side wall 2. The bearing assembly 22 extends beyond the outer face of the side wall 2 and is backed up by a bearing pedestal 40 which is secured, for example, by welding to the support plate 38 and the side wall 2. The rod 37 is horizontally supported in groove-like recesses provided in the base plate 1 and the support plate 38. The depth of the groove-like recesses is so designed that a clearance 39 is maintained between the base plate 1 and the support plate 38. The recesses and the rod 37 are located, for example, in that zone of the support plate 38 which is oriented towards the side wall 2. On that side of the base plate 1 which is oriented away from the side wall 2, there are provided a set screw 41 and a securing screw 42 which pass perpendicularly through the support plate 38. The securing screw is received in a complemental thread provided in the base plate 1. The structure shown in FIG. 4 and described in connection with the side wall 2 is duplicated at the opposite side wall 3.
The base plate 1, the support plate 38, the bearing pedestal 40 and the flange 26, together with the like components at the other side wall 3 form a central unit. During assembly of the carding machine, first the base plate 1 is assembled with the support plate 38 and the bearing pedestal 40 and aligned by means of the set screw 41. Thereafter the cylinder 17, together with the flanges 26 and 27 is inserted into the central unit. In this manner, a stable support for the cylinder 17 is effected. Only thereafter are the side walls 2 and 3 inserted and secured. Subsequently, the other carding organs are secured to the side walls 2 and 3 and to the flanges 26 and 27 integral therewith.
It is to be understood that the above description of the present invention is susceptible to various modifications, changes and adaptations, and the same are intended to be comprehended within the meaning and range of equivalents of the appended claims. | A card has a frame including two parallel-spaced, rigidly supported side walls having lateral surfaces, a lickerin and a doffer disposed between the side walls and mounted on the lateral surfaces thereof; and carding organs situated between the lickerin and the doffer. At least some of these carding organs are, with their lateral end faces, disposed immediately adjacent the lateral surface of the respective side wall and are laterally mounted on the side walls. | 3 |
CROSS-REFERENCE TO RELATED APPLICATION
This application is a continuation-in-part of U.S. application Ser. No. 10/347,740, now U.S. Pat. No. 6,944,891, filed Jan. 20, 2003.
STATEMENT OF FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
Not applicable.
BACKGROUND OF THE INVENTION
The present invention relates to toilets provided with improved trapways.
Conventional toilets have a bowl portion and a storage tank portion, usually formed in one or two main pieces. A serpentine passage is typically positioned behind and below the bowl to transport the contents of the bowl to waste/sewer/septic plumbing lines of the building. This passage is generally referred to as the “siphon” or “trapway”.
An up leg portion of such a passage is normally filled with water to “trap” sewer gases downstream thereof, so as to prevent them entering the building interior. Water is maintained in the bowl and the up leg part of the trapway by an arched portion of the trapway. The trapway (sometimes in conjunction with an adjacent jet) generates a siphon to evacuate the bowl contents when a normally air/vapor-filled downstream portion of the trapway is rapidly filled with water during the flush cycle.
The trapway thus helps retain water in the bowl prior to flushing, and then assists in the formation of a siphon helpful in removing waste during the flush cycle. Achieving these dual functions can be relatively easy where a large volume of water is used during a single flush cycle. However, for environmental and water conservation reasons many jurisdictions now restrict the sales of toilets which use too much water per flush. For example, some such regulations require no more than 1.6 gallons (6.06 liters) of water to be used per flush cycle.
Achieving an effective flush with that little water when the bowl is filled with feces, toilet paper, and other solids can be difficult. Hence, it is common with respect to some such low water usage toilets for consumers to flush the toilet twice or more to clean the bowl to their satisfaction when other than just urine is present. This not only frustrates the regulatory and conservation goals, it is time consuming for consumers.
Even where a toilet is reasonably efficient in its cleaning when using low amounts of water, there is also an interest in minimizing the time that the flush cycle takes. A short flush cycle has a number of advantages. For example, the period during which the toilet is generating maximum noise may be reduced if the flush cycle takes less time. This may be of interest if the toilet is being used during the middle of the night and the user wishes to minimize the possibility of others who are sleeping (e.g. a baby) being disturbed. Another advantage of a short flush cycle is that with such a cycle, if a second flush is needed to complete bowl cleaning, it can begin sooner.
Various attempts to accomplish a shorter flush cycle have included specially shaping the flow path, controlling the state of flow (turbulent or laminar), and/or reducing or eliminating the occurrence of air pockets at particular locations in the trapway. For example, U.S. Pat. No. 5,918,325 discloses a trapway modified in various ways to attempt to render flushing more optimal. See also U.S. Pat. Nos. 3,484,873, 5,706,529 and 6,292,956. The disclosures of these patents, and of all other patents and publications referred to herein are incorporated by reference as if fully set forth herein.
However, attempts to develop quick flush action having efficient cleaning with low volumes of water can be frustrated by “blow back”, which is a tendency of such trapways to develop reverse flow of air from the plumbing lines into a low pressure region of the trapway. Accordingly, there is still a need for low volume flush toilets that have a short flush cycle, yet clean even solid bowl waste effectively and efficiently.
SUMMARY OF THE INVENTION
The invention provides a toilet having a trapway with improved water and air evacuation characteristics. In one aspect the trapway extends between a bowl opening and an outlet, the trapway having a curved water dam region extending from the bowl opening to above the bowl opening to a down leg. The down leg slopes in a rearward direction from its top to an essentially horizontal baffle extending forward from a rear wall of the down leg adjacent a lower portion of the down leg, the lower portion of the down leg being linked to an out leg communicating with the outlet.
Preferably, the dam down leg radius is between about 2.25 and 3.5 inches (, and the down leg slopes less than 15 degrees from vertical, more preferably between about 1 and 8 degrees from vertical. The baffle preferably has a ledge length of between about 0.5 and 2.5 inches measured from the rear wall of the down leg, and even more preferably between about 0.7 and 1.5. The baffle has a ledge height of between about 1.5 and 3.0 inches measured from a bottom of the out leg, and more preferably between about 1.75 and 2.5 inches.
In another preferred form, the trapway has a circular cross-section throughout the curved water dam region. The curved water dam region preferably includes a dam down leg radius adjacent the down leg between about 1.5 and 4.0 inches.
In other preferred forms at least a portion of the out leg is straight and preferably horizontal, and at least a portion of the down leg is straight. In still other preferred forms the up leg has a circular cross-section, or it has a flat interior wall. In yet another preferred form the out leg has a circular cross-section or a flat interior wall.
It is most preferred that the trapway have a minimum ball passage of about 2 inches.
In another form the toilet also has a jet providing a capability for a flow rate of between 22 and 28 (preferably about 25) gallons per minute.
The present invention thus provides a toilet with a unique trapway design. It is designed so that water from the bowl completely and quickly fills key portions of the trapway during a flush cycle. This leads to rapid evacuation of the bowl contents, minimizing water waste. The trapway design improves the full flush cycle time and significantly improves the rate of the flushing action to nearly half that of common gravity driven toilets with conventional trapway designs.
The rearwardly slightly canted down leg reduces the formation of air pockets in the water dam region which would otherwise interfere with the siphoning effect of the trapway. The baffle ledge breaks up the water passing from the down leg to entrain air and particles, and further promote their rapid evacuation through the trapway. The uniform circular cross-section of the curved water dam region helps to lift the surface of the fluid at the water dam during siphon initiation, which further helps to remove air.
These and still other advantages of the invention will be apparent from the detailed description and drawings. What follows is merely a description of preferred embodiments of the present invention. To assess the full scope of the invention the claims should be looked to as the preferred embodiments are not intended to be the only embodiments within the scope of the claims.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a left side elevational view of a toilet trapway according to the present invention, with a typical environment that the trapway can used in being shown in dotted lines;
FIG. 2 is a vertical cross-sectional view taken down the front-to-back center line of the rear portion of the toilet of FIG. 1 ;
FIG. 3 is a cross-sectional view taken along line 3 — 3 of FIG. 2 ;
FIG. 4 is a cross-sectional view taken along line 4 — 4 of FIG. 2 ;
FIG. 5 is a reverse side view showing half of the trapway diagrammatically;
FIG. 6 is a cross-sectional view taken along line 6 — 6 of FIG. 5 ;
FIG. 7 is a cross-sectional view similar to FIG. 6 , albeit taken along line 7 — 7 of FIG. 5 ;
FIG. 8 is a cross-sectional view similar to FIG. 6 , albeit taken along line 8 — 8 of FIG. 5 ;
FIG. 9 is a cross-sectional view similar to FIG. 6 , albeit taken along line 9 — 9 of FIG. 5 ;
FIG. 10 is a diagrammatic representation of the trapway showing an air pocket (in full cross-hatch) generated by an air dam in an out leg of the trapway and also an air pocket (in phantom) formed by waste line blow back to a low pressure area in a down leg of the trapway not present in the trapway disclosed herein but which did occur in some prior trapway designs;
FIG. 11 is a view similar to FIG. 1 , but of a second embodiment;
FIG. 12 is a view similar to FIG. 2 , but of the second embodiment;
FIG. 13 is a cross-sectional view taken along line 13 — 13 of FIG. 12 ;
FIG. 14 is a diagrammatic representation of the trapway of FIG. 11 , with identification of certain parameters of the trapway:
FIGS. 15A and 15B are cross-sectional views showing alternate versions of an up leg of the trapway taken along line 15 — 15 of FIG. 12 ; and
FIGS. 16A and 16B are cross-sectional views showing alternate versions of an out leg of the trapway taken along line 16 — 16 of FIG. 12 .
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
FIG. 1 illustrates a toilet 10 having a siphon passage or trapway 12 design according to the present invention. In particular, other than the trapway 12 , the toilet 10 can be any suitable toilet, preferably of a low volume flush design.
For example, FIG. 1 shows in hidden lines a two-piece type toilet having a separate flush tank 14 mounted to a bowl base 16 . A hole (not shown) in the bottom of the flush tank 14 aligns with a hole (not shown) in the top of the bowl base 16 to allow water to pass from the flush tank and into the a bowl 18 , formed in the bowl base 16 , during a flush cycle.
The trapway 12 extends from an opening 20 in the bowl 18 along a serpentine path, having for much of its length an essentially uniform and constant circular cross-section (as shown in FIG. 3 ). This cross-section is present at least in the second bend 30 at the dam 34 .
The trapway has an outlet opening 22 at the bottom of the base of bowl 16 , which mounts over the open end of a waste plumbing line (not shown). The trapway 12 thus creates a path for contents in the bowl 18 to flow to the waste/sewer/septic line during a flush cycle.
Referring to FIG. 2 , an entry 24 of the trapway 12 extends back from the bowl opening 20 to a first bend 26 . An essentially straight backwardly directed up leg 28 extends from the first bend 26 at about a 40–60 degree angle to the second bend 30 . A down leg 32 extends from the second bend 30 declining slightly backwardly from top to bottom away from the opening 20 at, preferably, an angle approximately between 1–10 degrees from vertical, most preferably a 4–6 degree angle.
The bend 30 forms about a 40 degree angle between the up leg 28 and the down leg 32 so as to change flow direction about 140 degrees from the direction of flow through the up leg 28 . The surface at the inside diameter of the second bend 30 forms water dam 34 (along the lower inside surface), after which point water can pass through the downstream portion of the trapway 12 .
The bottom end of the down leg 32 transitions at another bend 36 which leads to a short, straight forwardly declining leg 38 . Leg 38 terminates at a bend leading to a straight, horizontal out leg 42 ending at a 90 degree bend 44 leading to the outlet opening 22 .
The trapway 12 has a generally uniform circular cross-section between the bowl opening and throughout the curved second bend 30 at the water dam 34 and through the down leg 32 . Preferably, the inside cross-section does not vary more than 5 percent in diameter throughout this portion of the trapway 12 . FIGS. 6–9 illustrate the non-circular cross-sections of the short angled leg 38 and the out leg 42 , which have flat lower surfaces, primarily for casting considerations.
Adjacent the bottom end of down leg 32 , the trapway 12 has a short, flat horizontal baffle 46 extending between the rear wall of the down leg 32 and the short angled leg 38 . The baffle 46 preferably extends a length about equal to the radius of the down leg 32 , or in one case about 1 1/16 inches. The baffle 46 works to generate turbulence and change the trajectory of the flow leaving the down leg 32 , which helps move the flow downstream.
A recessed cavity or pocket 48 , referred to herein as an air dam 48 , is optionally formed to extend about an upper interior portion of the out leg 42 on a side of a centerline 50 opposite the outlet opening 22 . Preferably, the air dam 48 is adjacent to the intersection of the angled leg 38 and the out leg 42 . The air dam 48 extends upwardly from an upper interior surface of the out leg 42 preferably in a smooth, contoured pyramidal-type configuration such that its base is larger than its tip, as shown in FIG. 4 .
Note, however, that the air dam 48 could be any suitable shape, such as hemi-spherical, as long as a sharp or small radius edge is formed at the leading edge of the air dam 48 sufficient to cause separation of the flow from the trapway 12 . Preferably, the upstream upwardly extending surface 51 of the air dam 48 forms about a 90 degree angle or less to aid in separation of the fluid from the surface of the trapway 12 as described below.
FIGS. 7 and 8 show half cross-sections of the through the out leg 42 at the air dam 48 . The air dam 48 can be about ½ to 1 inch (preferably ⅝″) high, about ½ to 3 inches in length (preferably 1½″) and about the diameter of the out leg 42 (preferably 2⅛″).
The trapway 12 is designed so that water from the bowl completely and quickly fills key portions of the trapway 12 during a flush cycle. This is achieved because the backwardly canted down leg 32 reduces or eliminates the formation of air pockets at the water dam 34 which interfere with the siphoning effect of the trapway 12 , the uniform circular cross-section of the second bend 30 helps to lift the surface of the fluid at the water dam 34 during siphon initiation.
Furthermore, the air dam 48 aids in rapid flushing by separating the fluid from the inside wall of the down leg 32 causing a sheet of fluid within the trapway 12 that tends to block air that may try to pass back through the trapway 12 from the waste line to a low-pressure region in the down leg 42 downstream from the water dam 34 . More specifically, as shown in FIG. 10 , during flushing fluid passes beyond the water dam 34 into the down leg 32 and the other normally air-filled downstream portions of the trapway.
Fluid leaves the lower end of the down leg and into the short angled leg 38 . After leaving the lower end of the short angled leg 38 , fluid at the upper surface (when viewed as shown in FIG. 2 ) of the trapway passes by a leading edge surface 52 of the air dam 48 (preferably being a small radius convex surface or a short flat sharp angle surface) which leads to the upwardly extending surface 51 of the air dam 48 preferably forming a right or acute angle with the short angled leg 38 . This causes the fluid to separate from the upper surface of the trapway at a relatively high velocity. This in turn causes an air pocket 54 to form generally in the region of the out leg 42 shown by the solid cross-hatching.
This effectively reduces the cross-sectional area through the out leg 42 , which increases the pressure and velocity of the fluid through the out leg 42 . This does two things. It increases the rate that the fluid passes through the out leg 42 (despite the smaller cross-sectional area) and causes the fluid to generate a greater down-ward force to counter the force of air in the waste line tending to move to a low pressure region in the down leg 32 and forming an air pocket 56 in the down leg 32 as represented by the hidden line cross-hatching, which is may occur sporadically depending on which pressure prevails. This phenomenon, referred to as “blow back”, is adverse to providing a rapid, powerful flush. Thus, the air dam 48 helps prevent blow back, and thus allows the fluid to pass through the full area of the down leg 32 and short angled leg 38 , and speeds the rate of flow through the out leg 42 .
FIGS. 11–14 illustrate another preferred embodiment of the invention, with features analogous to the aforementioned embodiment being referenced using like reference numbers albeit preceded by the numeral “1”. The trapway of this embodiment is of essentially the same construction as the aforementioned embodiment, however, without the air dam feature at the out leg.
In particular, like above in this embodiment the toilet 110 has a siphon passage or trapway 112 extending from an opening 120 in the bowl 118 along a serpentine path, having an essentially uniform, cross-section, such as the circular cross-section (as shown in FIG. 13 ) at the water dam 134 . The outlet opening 122 opening at the bottom of the bowl base 116 mounts over the open end of a waste plumbing line (not shown) so that the trapway 112 creates a path for contents in the bowl 118 to flow to the waste line during a flush cycle.
Referring now to FIG. 12 , a straight entry 124 of the trapway 112 extends back from the bowl opening to a first upward bend 126 . An essentially straight up leg 128 , having an essentially uniform circular (as shown in FIG. 15A ) or flattened circular (as shown in FIG. 15B ) cross-section, extends upwardly from the first bend 126 at about a 40 – 60 degree angle to a second bend 130 . A down leg 132 extends from the second bend 130 declining slightly backwardly from top to bottom away from the bowl opening.
The second bend 130 forms about a 40 degree angle between the up leg 128 and the down leg 132 . The surface at the inside diameter of the second bend 130 forms the water dam 134 (along the lower inside surface) after which point water can pass from the bowl to the waste line through the downstream portion of the trapway 112 . The bottom end of the down leg 132 transitions at another bend 136 which leads to a short, straight forwardly declining leg 138 . Leg 138 terminates at a bend 140 leading to a straight, horizontal out leg 142 ending at a 90 degree bend 144 leading to the outlet opening 122 .
The trapway 112 can have a generally uniform circular cross-sections including between the bowl openings throughout the curved second bend 130 at the water dam 134 and through the down leg 132 (see FIGS. 13 , 15 A and 16 A). In this case, preferably, the inside cross-section does not vary more than 5 percent in diameter throughout this portion of the trapway 112 . The up leg 128 and out leg 142 sections of the trapway 112 could, alternatively, have flattened lower surfaces, essentially forming a linear chord surface intersecting the inner diameter of these legs (see FIGS. 15B and 16B ). This flattened configuration of the up leg 128 and the out leg 142 is similar to the non-circular cross-sections of the short angled leg 38 and the out leg 42 of the aforementioned embodiment shown in FIGS. 6 and 9 , which have flat lower surfaces primarily for casting considerations.
Adjacent the bottom end of down leg 132 , the trapway 112 has a short, flat horizontal baffle 146 extending between the rear wall of the down leg 132 and the short angled leg 138 . The baffle 146 works to generate turbulence and change the trajectory of the flow leaving the down leg 132 , which helps move the flow downstream.
The trapway 112 is designed so that water from the bowl completely and quickly fills key portions of the trapway 112 during a flush cycle. This is achieved because the backwardly canted down leg 132 reduces or eliminates the formation of air pockets at the water dam 134 which interfere with the siphoning effect of the trapway 112 , the uniform circular cross-section of the second bend 130 also helps to lift the surface of the fluid at the water dam 134 during siphon initiation.
Fluid passes beyond the water dam 134 into the down leg 132 and the other normally air-filled downstream portions of the trapway. Fluid leaves the lower end of the down leg 128 and is interrupted by the baffle 146 before entering the short angled leg 138 . This disruption causes turbulent flow through the out leg 142 which works to entrain air in this region and thereby increase the rate that the fluid passes through the out leg 142 to counter air blow back.
With reference to FIG. 14 , the trapway 112 is configured with several design parameters intended to achieve rapid flushing action. Several of this parameters were discussed above, however, the following table summarizes eleven of the most significant parameters. Where appropriate, a range of preferred values is provided for each parameter.
TABLE 1
Trapway design parameters.
Parameter
Range
Trapway up leg radius (r 1 )
2.0–4.0 inches
Trapway up leg angle (θ 2 )
45–60 degrees
Up leg shape
Round or flat
Trapway dam up leg radius (r 3 )
1.0–3.0 inches
Trapway dam down leg radius (r 4 )
1.5–4.0
Trapway dam down leg angle (θ 3 )
0–15 degrees
Trapway corner radius (r 5 )
1–5 inches
Baffle ledge length (L 1 )
0.5–2.5 inches
Baffle ledge height (h 1 )
1.5–3.0 inches
Out leg shape
Round or flat
Outlet diameter (D o )
2.0–3.0 inches
The ranges provided above are selected for a trapway with a ball passage of about 1.8 to 2.1 inches and a toilet with jet way, as understood in the art, providing an initial flow rate of approximately 25 gallons per minute (“gpm”) and a “hold down” flow rate, in which the water level in the bowl is at or below the bowl opening, of approximately 10 gpm.
Of the eleven parameters noted above, the inventors of the present invention have determined empirically that the three parameters most critical to rapid flushing are the trapway to dam down leg radius (r 4 ), down leg angle (θ 3 ), and the baffle ledge length (L 1 ).
The down leg 132 is designed to extend from the second bend 130 backwardly from top to bottom away from the bowl opening at, preferably, an angle approximately between 1–15 degrees from vertical, more preferably between about 1–8 degrees, and most preferably between about 4–6 degrees from vertical. The down leg trap radius (r 4 ) is preferably 1.5–4.0, and more preferably 2.25–3.5 inches. This radius is selected to help develop the liquid flow profile over the water dam to ensure water flows closely around the inner bend of the water dam and push downstream air in this region toward the outlet.
The baffle 146 preferably extends a length of about 0.5–2.5 inches and more preferably about 0.7–1.5 inches for more optimal interruption of the water flow without closing off the passageway excessively. Further, the baffle 146 is preferably disposed at a height of about 1.5–3.0 inches from the lower surface of the out leg, and more preferably at about 1.75–2.5 inches. As mentioned, these valves are selected for a ball passage of about 2 inches. The baffle ledge height and length will vary up or down proportionally to the radius of the down leg.
It should be appreciated that preferred embodiments of the invention have been described above. However, many modifications and variations to the preferred embodiments will be apparent to those skilled in the art, which will be within the spirit and scope of the invention. Therefore, the invention should not be limited to the described embodiments. To ascertain the full scope of the invention, the following claims should be referenced.
INDUSTRIAL APPLICABILITY
The invention provides improved toilets that more efficiently flush waste material by assisting downstream flow of air in the trapway and by resisting upstream air blow back into the trapway. | A toilet has a trapway extending between a bowl opening and an outlet opening. The trapway defines a curved, preferably uniform circular cross-section water dam region above the bowl opening, a down leg, and a straight out leg between the down leg and the outlet opening. The down leg has a rearward slope where is located a horizontal baffle. The inclined down leg and horizontal baffle work in concert to prevent the back flow of air to a region above the dam as well as to facilitate rapid entrainment and evacuation of air below the dam. | 4 |
BACKGROUND OF THE INVENTION
[0001] This invention deals generally with farm machinery and more specifically with an electronic speed control for self propelled farm machines.
[0002] It is quite interesting that large self propelled farm machines are not all powered or steered in the same manner as the road vehicles with which we are familiar. Such machines are not powered by direct mechanical linkages from the engine to the drive wheels, and are not steered by changing the angle of the vertical planes of the wheels. The wheels of many such self propelled farm machines, including large farm tractors, are coupled to their engines by hydraulic systems. The engine directly drives hydraulic pumps, and those pumps are connected by hoses to hydraulic motors that are located at and turn the wheels. Wheel speed is then controlled by changing the quantity of hydraulic fluid that the pump delivers to the wheel motor. Furthermore, to reverse the motion of the hydraulic motor and thus reverse the direction of the wheel the direction of the hydraulic fluid flow is reversed.
[0003] It is even more interesting to note that the steering of such self propelled farm machines is accomplished by the very same system as the speed and forward and reverse directional control. The very large wheels of such equipment are not steered as automobile wheels are, but instead, the direction of the machine is changed by driving the wheels at different rotational speeds. Thus, for a typical self propelled farm machine with two forward drive wheels and two caster type smaller rear wheels, if the right forward wheel is stopped and the left forward wheel is rotated forward, the tractor will turn toward the right. In fact, if instead of being stopped, the right forward wheel is rotated in reverse at the same speed the left wheel is rotated forward, the tractor will turn right around the center of its own wheel axis.
[0004] Typically, the speeds of the wheels have been controlled by the machine operator using a lever with a direct mechanical linkage to a speed control rod interconnected with the two hydraulic pumps, one each for the right and the left wheels. The steering control also acts on these same two hydraulic pumps. The steering wheel is used to rotate the speed control rod that is connected to the pump interconnection linkages. The rotation of the speed control rod is around its own axis, and the pump linkages themselves are connected to the control rod by oppositely threaded collars. Thus, when the speed control rod is rotated, the pump linkages either come closer together or farther apart, depending upon the direction of rotation. This change in the spacing of the pump linkages changes their response to the motion of the speed control rod, and thus causes the right and left wheels to operate at different speeds and the farm machine to turn.
[0005] There is a significant trend in the farm equipment industry to automate farm equipment. It is particularly advantageous for very large fields to operate these machines under conditions where their speed is held closely to a setting set by the operator. In effect, it means placing self propelled farm machines in a “cruise control” mode. However, farm machines are subjected to rapidly occurring and widely varying load conditions that make any speed control difficult, and automatic speed control particularly difficult. One example is the condition of a machine suddenly coming under full load and therefore causing the engine to slow down, but instead being asked by either an automatic control system or an operator to regain speed. Such a condition is particularly likely when a machine includes an automatic speed control that quickly recognizes only that the machine is slowing down from the selected speed, and therefore automatically attempts to increase the speed. Under such conditions the engine, which is already fully loaded, will stall unless the operator intercedes and actually reduces the speed setting. With automatic speed controls becoming much more common for the large machines, it would be very desirable to have a control system that not only regulates the machine ground speed based on a control setting by the operator, but would also assure that no situation arises that causes the engine to stall because of loading.
SUMMARY OF THE INVENTION
[0006] The particular system of powering and steering self propelled farm machines by hydraulic motors at the wheels provides an opportunity for much improved vehicle speed control. The preferred embodiment of the invention uses a microprocessor to evaluate all the conditions to which the machine is subjected and to adjust the machine ground speed in a manner and at a rate that prevents stalling the engine. Furthermore, the present invention, although including the ability to accurately return to a desired previous speed, maintains the ground speed based upon the operator's speed control lever setting.
[0007] It should be appreciated that in the preferred embodiment of the invention the operator's speed control lever is not what we are accustomed to in an automobile. The farm machinery's speed control lever is not at all like an accelerator pedal and much more like a console gear shift lever. Thus, the operator actually sets a speed control lever position to set the desired ground speed of the machine, and that lever is not spring loaded, but holds its position until it is manually moved.
[0008] In the preferred embodiment of the invention, this lever setting is read by a speed control position sensor and an appropriate electrical signal is sent to the on-board microprocessor. The microprocessor then sends a related signal to a control valve that controls the hydraulic pressure to and the direction of movement of a speed control hydraulic cylinder that is attached to the prior art speed control rod. This is the same speed control rod which, in the prior art systems, is directly mechanically linked to the operator's speed control lever and controls the hydraulic pumps that feed the hydraulic motors driving the wheels.
[0009] The significant benefit of the insertion of a system of microprocessor driven electrical and hydraulic controls into the previous direct mechanical linkage is the ability to now control the machine speed based upon multiple parameters. For example, by using a ground speed sensor means with its signal supplied to the microprocessor, the microprocessor can more accurately maintain the ground speed based on the operator's speed control lever position. Previously, if the machine began slowing down, for instance, because of a hill, it was the operator who was required to adjust the speed control lever to a higher speed. In the present invention, the microprocessor senses the slowing down and quickly, certainly much faster than an operator could, increases the power to the wheels. The benefit of the present invention is that the operator's speed control lever becomes a control that can be labeled for precise ground speed settings, not merely, as in the prior art, a control to adjust the power output of the engine.
[0010] With the present invention, after a long straight run down a field at a prescribed speed, the speed control lever is typically reset to a lower speed for turning the machine around in the “headlands” at the end of the field. Any movement of the speed control lever outside of a specified narrow range is interpreted by the controller as an operator input requiring a new closed loop speed. Then, once the turn is completed, the operator moves the speed control lever forward to return the machine to a closed loop value near the speed value prior to entering the headlands.
[0011] Thus, by using an intuitive action by the operator, the new speed value as determined by the operator will be maintained as the newly regulated speed value by the controller.
[0012] Another significant benefit of the microprocessor and hydraulically controlled speed is the ability to dynamically adjust to load conditions. Field load condition variations may be crop density variations or terrain elevation changes, but are not limited to these two conditions. Various types of sensors are connected to the controller to report such load conditions during operation.
[0013] If the engine is operating at conditions requiring near maximum power, it is possible that increased field load conditions could stall the engine. In such cases, the controller is programmed to autonomously reduce speed value and thus, engine load, until less demanding field load conditions prevail. When sensors report that lighter load conditions are encountered, the controller will return the speed to the previous value.
[0014] The present invention thereby not only provides a fast response automatic speed control for self propelled farm machines, but also accommodates to all load conditions.
BRIEF DESCRIPTION OF THE DRAWING
[0015] FIG. 1 is a simplified block diagram of the prior art manual steering and speed control apparatus of a typical self propelled farm machine.
[0016] FIG. 2 is a simplified block diagram of the automatic speed control apparatus of the preferred embodiment of the invention.
DETAILED DESCRIPTION OF THE INVENTION
[0017] FIG. 1 is a simplified block diagram of the manual steering and speed control apparatus 10 of a typical self propelled farm machine. Motive power is delivered to left wheel 12 and right wheel 14 by hydraulic motors 16 and 18 , respectively. Hydraulic motors 16 and 18 are themselves powered from left hydraulic pump 20 and right hydraulic pump 22 , which are mechanically powered from the machine's engine (not shown) by conventional mechanical linkages (not shown).
[0018] Left pump 20 and right pump 22 supply hydraulic fluid under pressure to wheel motors 16 and 18 through hydraulic lines 24 . Each of pumps 20 and 22 has the capability of rotating its associated wheel motor so that the powered wheel will go forward or in reverse, and if the pump is in its neutral setting, to not power the wheel at all. The three settings of pumps 20 and 22 are indicted in FIG. 1 as “FWD”, “REV”, and “N”. Moreover, pumps 20 and 22 are not simple on and off devices, but their fluid outputs vary with the position of their control arms 26 and 28 . Thus, the farther each control arm 26 and 28 is moved away from the neutral position, the greater is the power delivered to the associated hydraulic motor and wheel.
[0019] Control arms 26 and 28 are both attached to speed control rod 30 , and speed control rod 30 is displaced axially, in the so called “common mode”, by speed control lever 32 that the machine operator moves. Speed control lever 32 is a simple lever that pivots on pin 34 attached to a point on machine chassis 36 and to a pivoting link on speed control rod 30 . With that simple mechanical linkage, as the operator moves speed control lever 32 , control arms 26 and 28 change the status of pumps 20 and 22 and vary the power delivered to wheels 12 and 14 . When, as shown in FIG. 1 , control arms 26 and 28 are parallel, pumps 20 and 22 respond equally to movement of speed control lever 32 and wheels 12 and 14 move in the same direction and at the same speed so that the machine moves straight ahead.
[0020] However, typically the steering system of the machine is also controlled by pumps 20 and 22 . To change the direction of such a farm machine, the speeds of drive wheels 12 and 14 are made to be different from each other, with one wheel turning slower than the other. This is accomplished by making left pump 20 and right pump 22 deliver different quantities of hydraulic fluid to their respective wheel motors, which can be accomplished by rotating a conventional steering wheel (not shown).
[0021] The rotation of such a steering wheel is mechanically transmitted to rotational drive 38 attached to and capable of rotating speed control rod 30 . Rotational drive 38 can typically be a gear linked to the steering wheel. As previously described, axial motion of speed control rod 30 moves control arms 26 and 28 that control the power that pumps 20 and 22 deliver to their respective wheel motors, and as long as control arms 20 and 22 are oriented in parallel, the power delivered to the wheel is equal. However, control arms 20 and 22 are attached to speed control rod 30 by threaded collars 40 and 42 that engage thread sets 41 and 43 respectively, and thread sets 41 and 43 have oppositely directed threads. Thus, the rotation of speed control rod 30 , referred to as the “differential mode”, changes the effect of the axial position of speed control rod 30 on pumps 20 and 22 , and thus changes the speed of wheels 12 and 14 .
[0022] For example, assuming a farm machine has its manual steering and speed control apparatus 10 set as shown in FIG. 1 , that is, both control arms have their pumps set in Neutral position. Then, rotating speed control rod 30 in the direction indicated by arrow “A” would cause control arm 26 to move toward the “Forward” setting of left pump 20 and control arm 28 to move toward the “Reverse” setting of right pump 22 . If engine power were then applied to both pumps, left wheel 12 would rotate for forward movement and right wheel 14 rotate for reverse movement. This action would actually cause the machine to rotate to the right around the central point of the axle between the right and left wheels. This same effect will occur when both pumps are set for forward motion, except that rotating speed control rod 30 will then cause one wheel to rotate faster and the other to slow down. This will then cause the machine to turn.
[0023] FIG. 2 is a simplified block diagram of automatic speed control apparatus 50 of the preferred embodiment of the invention which is used in conjunction with the prior art steering and speed control apparatus shown in FIG. 1 . To operate automatic speed control apparatus 50 with the prior art apparatus of FIG. 1 , automatic speed control apparatus 50 is inserted between speed control rod 30 and speed control lever 32 to the left of the separation point indicated by the dashed line B-B in FIG. 1 .
[0024] As shown in FIG. 2 , speed control rod 30 is then moved axially by hydraulic cylinder 52 , and speed control lever 32 is interconnected with speed control position sensor 54 . Speed control position sensor 54 indicates the position at which speed control lever 32 has been set, and speed control position sensor 54 is only one of several sensors from which microprocessor 56 derives information. Two other sensors interconnected with and supplying signals to microprocessor 56 are ground speed sensor means 58 and engine speed sensor 60 .
[0025] These sensors are all conventional devices. For instance, in the preferred embodiment of the invention speed control position sensor 54 is a dual hall effect rotary position sensor, ground speed sensor means 58 is a reluctance sensor on each wheel, and engine speed sensor 60 for four cylinder engines is an alternator signal and for six cylinder engines is a magnetic sensor. Each of these devices supplies an appropriate electronic signal to microprocessor 56 , which then interprets the conditions of the machine and takes action according to its internal program.
[0026] When the machine operator sets speed control lever 32 to any particular position for a specific machine speed, speed control position sensor 54 provides a signal to microprocessor 56 , and under normal conditions, microprocessor 56 provides appropriate signals to control valve 62 . Based on the signals received from microprocessor 56 , control valve feeds hydraulic pressure to hydraulic cylinder 52 , and speed control rod 30 , which is attached to hydraulic cylinder 52 is moved accordingly. FIG. 2 depicts a typical hook up in which pressure from control valve 62 moves hydraulic cylinder 52 and speed control rod 30 toward the right, and thus, based on the previous description of FIG. 1 , reduces the wheel speed of the machine. Similarly control valve 62 causes hydraulic cylinder 52 and speed control rod 30 to move to the left to increase wheel speed.
[0027] Programmed microprocessor 56 , with information received from ground speed sensor means 58 and engine speed sensor 60 , actually controls the ground speed to maintain the speed set by the operator and it also controls the engine speed of the machine to assure that there is enough power to do so. However, when, due to increasing load conditions, more power is needed than the engine can supply, a condition that would normally cause the engine to stall, rather than attempting to increase the speed of the engine, microprocessor 56 , based on its program, lowers the ground speed of the machine to counteract the increased load. This is exactly what a well experienced operator would do in regard to engine overloading based on his own sensory inputs for sound and vibration in the machine.
[0028] Of course, the present invention can be used by even an inexperienced operator, and automatic speed control apparatus 50 also has the advantage of automatically returning to the preset ground speed as soon as load and engine conditions will permit.
[0029] Another feature available by the use of microprocessor 56 is that a previous speed setting is retained in memory.
[0030] The present invention thereby not only provides a fast response automatic speed control that does not require the skill of a highly trained operator, but also provides an automatic speed control that adjusts to varying load conditions.
[0031] It is to be understood that the form of this invention as shown is merely a preferred embodiment. Various changes may be made in the function and arrangement of parts; equivalent means may be substituted for those illustrated and described; and certain features may be used independently from others without departing from the spirit and scope of the invention as defined in the following claims. For example, different sensors could be used for any of the parameters as long as the sensor output can be modified to furnish appropriate input signals to microprocessor 56 . Furthermore, hydraulic cylinder 52 and control valve 62 could be replaced by an electrical speed control power apparatus to provide and control the axial motion of speed control rod 30 . Moreover, speed control lever 32 can also be replaced with some other type of control. | The apparatus is an electronic speed control for farm machines. A microprocessor is fed data on the tractor engine speed, the tractor ground speed, and the manual speed lever setting, and electronically matches the desired ground speed to the engine speed to prevent stalling the engine. Ground speed is controlled by using the microprocessor to electrically vary a control valve that replaces the usual mechanical linkage between the speed control lever and the hydraulic pumps driving the hydraulic wheel motors. | 5 |
This application is a continuation of U.S. patent application Ser. No. 13/120,441, filed Mar. 23, 2011, which is a 371 of PCT/US2009/058614, filed Sep. 28, 2009, which claims priority to U.S. Provisional Application No. 61/100,318 filed on Sep. 26, 2008, the contents of all of which are hereby incorporated by reference in their entirety.
BACKGROUND
Currently, the only batteries (rechargeable or non-rechargeable) commercially available with ZnMn chemistries are round bobbin cells. ZnMn chemistries are low cost and lightweight, are environmentally benign, and have a very long charge retention. Round bobbin cells have a positive electrode that is stamped or pressed into a cylindrical hollow pellet and seated into a can, and the negative electrode is a gel that is filled into the center void of the positive electrode.
The high internal resistance of low capacity round bobbin cells limits the currents (i.e., power) that they can deliver. In contrast, flat plate (electrode) cells can be scaled up to large sizes providing high currents and storage capacities.
CA 2 389 907 A1 relates to a method of producing flat plate electrodes in a small format that exhibit high current densities, higher utilization of the active materials, and better rechargeability. The method of forming the electrodes requires the active materials, binders, thickening agents, additives, and an alkaline electrolyte to form a paste that is applied to a current collector. CA 2 389 907 A1 provides is a flat plate rechargeable alkaline manganese dioxide-zinc cell.
What is needed are low cost, lightweight, environmentally friendly batteries that can be used, for example, for large power back-up systems, which are primarily currently served by lead acid and NiCd chemistries. Such batteries should exhibit improvements in, for example, current density, memory effect (i.e., capacity fade), shelf life, charge retention (e.g., at higher operation temperatures), and voltage level of discharge curve over known round bobbin and flat plate cells.
SUMMARY
Provided is a flat plate electrode cell. The flat plate electrode cell comprises positive electrode plates and negative electrode plates. The positive electrode plates each comprise manganese and compressed metal foam. The negative electrode plates each comprise zinc and compressed metal foam. The positive electrode plates can have aligned tabs and the negative electrode plates can have aligned tabs, and the flat plate electrode cell can further comprise a positive terminal formed from the aligned tabs of the positive electrode plates and a negative terminal formed from the aligned tabs of the negative electrode plates.
The rechargeable flat plate electrode cell of the present disclosure provides improvements in, for example, current density, memory effect (i.e., capacity fade), shelf life, charge retention (e.g., at higher operation temperatures), and voltage level of discharge curve over known round bobbin and flat plate cells. In particular, the rechargeable flat plate electrode cell of the present disclosure provides longer cycle life with reduced capacity fade as compared with known round bobbin and flat plate cells.
The rechargeable flat plate electrode cell of the present disclosure achieves such benefits primarily through unique electrode formation. In particular, both the positive and negative electrode of the rechargeable flat plate electrode cell of the present disclosure are formed from compressed metal foam, which provides both low resistance and high rate performance to the electrodes and the cell.
BRIEF DESCRIPTION OF THE FIGURES OF THE DRAWING
FIG. 1 depicts an embodiment of the assembly of positive (cathode) electrode plates and negative (negative) electrode plates.
FIG. 2 shows the improvements of the rechargeable flat plate electrode cell of the present disclosure over commercially available ZnMn round bobbin consumer cells in terms of Cell Capacity Versus Discharge Rate.
FIG. 3 shows the improvements of the rechargeable flat plate electrode cell of the present disclosure over commercially available ZnMn round bobbin consumer cells in terms of Cell Capacity versus Cycles/Life.
DETAILED DESCRIPTION
The rechargeable flat plate electrode cell of the present disclosure reduces the material costs, weight, toxicity (regulated limitations), volume, and maintenance of known batteries (e.g., batteries used for stationary power back-up applications), while increasing charge retention and reliability. The rechargeable flat plate electrode cell of the present disclosure can be used wherever high capacity DC power storage is required, can replace lead acid or NiCd large format batteries or other high power electric back-up systems, and can be used directly in applications that can accept a wide voltage range and in conjunction with a voltage stabilizing system when the application requires a narrower voltage range.
The rechargeable flat plate electrode cell of the present disclosure comprises one or more anode plates comprising anode paste and one or more cathode plates comprising cathode paste. The anode and cathode pastes each comprises active material metal powders (e.g., zinc and manganese, respectively) mixed with aqueous or organic binder to create a paste that can be consistently coated on one or both sides of a substrate. The substrate holds the active material (i.e., the paste) and acts as a current collector. In an embodiment, the substrate is made of a conductive material such as steel, Ni, or Cu, and may be plated with indium or Ni (i.e., a material that is non-active relative to MnO 2 ) for the cathode and Cu (i.e., a non-active material relative to zinc) for the anode. In an embodiment, the substrate comprises a porous conductive substrate such as, for example, perforated metal, metal foam, metal felt, expanded metal, or carbon foam. More specifically, the substrate comprises nickel foam and/or copper plated nickel foam. Accordingly, the anode or cathode paste is coated on and throughout the foam mesh.
The coated substrate is dried and sized (i.e., compressed) to create a highly conductive, dense, porous flat plate electrode. The flat plate electrodes are wrapped and sealed in a layer of barrier and separator material to prevent short circuits and dendrite growth. The wrapped and sealed flat plate electrodes are stacked in an alternating cathode and anode pattern that is repeated until a desired capacity of the cell is reached. Tabs (collectors) of the flat plate cathode electrodes are connected together and tabs of the flat plate anode electrodes are connected together. In an embodiment, the rechargeable flat plate electrode cell of the present disclosure is bi-polar. Such bipolar batteries use a substrate to hold the positive active materials on one side and negative active materials on the other and the substrate acts as a cell wall. The cell walls are sealed either peripherally or tangentially to hold internal pressure and electrolyte.
In metal foams, typically 75-95% of the volume consists of void spaces. As such, the use of metal foams allows for thicker electrode substrates without increasing the resistance of the electrode substrates. Target compression from sizing for this embodiment is between about 42% and 45%, which gives desirable porosity, required for low resistance/high rate performance of the rechargeable flat plate electrode cell.
Without wishing to be bound by any theories, it is believed that the high density of compression reduces the resistance within the paste by reducing the distance between active particles in the active material and reduces the resistance to the substrate by bringing the active particles closer to it. The high density reduces the volume so the energy density is increased. The high density also reduces the void volume in the active material which reduces the amount of electrolyte required to fill the electrode which in turn reduces the rate at which dendrites are formed which protects the cell from shorting and increases cycle life. The density level is critical since over-compression will cause dry spots in the active material where electrolyte cannot get to. These dry spots are very high resistance which reduces performance and can create gassing areas which cause cell failure.
Without sizing, desired energy density and high power capability are not achieved. The target coated sized thickness for the cathode is less than about 0.0300 inches. Coated sized thickness for the cathode greater than about 0.0300 inches results in rate capability (power) losses, while coated sized thickness for the cathode less than about 0.0200 inches results in energy density losses, due to excess inter electrode spacing and substrate relative to active material.
The anode paste comprises about 75-98 weight %, for example, about 83.1 weight %, zinc active material; about 0.01-1.0 weight %, for example, about 0.27 weight %, polymeric binder; and about 0-20 weight %, for example, about 16.6 weight %, solid zinc oxide. Exemplary zinc active materials include lead-free zinc and zinc alloy, such as, for example, in metallic, powder, granular, particulate, fibrous, or flake form.
The cathode paste comprises about 70-90 weight % electrolytic manganese dioxide; about 2-15 weight %, for example, about 7.5 weight %, graphite and/or carbon black; about 3-10 weight %, for example, about 6 weight %, polymeric binder; about 1-15 weight %, for example, about 5 weight %, barium compound; and about 0.01-10 weight %, for example, about 5 weight %, hydrogen recombination catalyst. Exemplary barium compounds include barium oxide, barium hydroxide, and barium sulfate. Exemplary hydrogen recombination catalysts include silver, silver oxides, and hydrogen absorbing alloys. The cathode paste may further comprise indium.
Exemplary polymeric binders of either the cathode paste or anode paste include carboxymethyl cellulose (CMC), polyacrylic acid, starch, starch derivatives, polyisobutylene, polytetrafluoroethylene, polyamide, polyethylene, and a metal stearate. The polymeric binder of either the cathode paste or anode paste can include conductive graphite, for example, conductive graphite having an average particle size between 2 and 6 microns.
The rechargeable flat plate electrode cell of the present disclosure differs from currently commercially available rechargeable ZnMn batteries in that the flat plate electrodes of the cell:
are flat; have an internal carrier (substrate); have a current collector attached to the internal carrier; and have the anode's active material completely sealed in a barrier to stop dendrite failures.
The rechargeable flat plate electrode cell of the present disclosure further differs from currently commercially available batteries in that:
flat plate cathode electrodes are produced by use of aqueous or organic binder and metal powder which is coated, dried and sized, instead of a glycol gel that is injected into a barrier wrapped pocket, which allows for the production of high volume flat plate electrodes required for economical power back-up batteries; flat plate anode electrodes are produced by use of an aqueous or organic binder and metal powder which is coated, dried, and sized, instead of mixing and then high pressure stamp forming into a ridged pellet, which allows for the production of high volume flat plate electrodes required for economical power back-up batteries; multiple flat plate cathode electrodes and flat plate anode electrodes can be connected in parallel then placed in a container, filled with electrolyte, and then sealed, instead of a cathode pellet wedged into a metal can, a barrier separator inserted into the cathode pellet cavity, and then anode gel injected into the cavity with a metal pin inserted into the center of the gel, and closed using a seal ring and crimping, which allows for the high capacity required for stationary power back-up batteries.
Advantages of the rechargeable flat plate electrode cell of the present disclosure include:
reducing battery cost through lower material costs, lower production costs, and using fewer components; reducing battery weight through higher energy dense chemistry, and using fewer components; reducing battery volume through higher energy dense chemistry, and using fewer components; reducing environmental and regulated (storage, disposal, shipping) issues by using environmentally friendly chemistry; improving reliability by using batteries with higher capacities and internal series collectors so fewer batteries/connections are used; reducing continuous energy losses by using a chemistry with higher charge retention; and reduces energy losses in the system by improving performance (charge efficiency, rate capability) through battery design that reduces losses from internal resistance in the battery.
FIG. 1 depicts an embodiment of the assembly of positive (cathode) electrode plates and negative (anode) electrode plates. In particular, cathode plate C 1 is stacked atop anode plate A 1 , which is stacked atop cathode plate C 2 , which is stacked atop anode plate A 2 . While not shown in FIG. 1 , in the electrode stack, the alternating positive and negative electrode plates can be separated by separator layers, which insulate the electrode plates from one another. Alternatively, the flat plate electrodes can be wrapped and sealed in a layer of barrier and separator material to prevent short circuits and dendrite growth, as explained above. The lightly shaded section of each of the electrode plates represents the portion thereof upon which cathode paste or anode paste, respectively, has been applied. The darkly shaded section of each of the electrode plates represents the portion thereof which has been pressed (i.e., “coined”) to create a thin, flat, high density area (e.g., about 0.15 inch wide), to which a tab can be welded. Accordingly, the unshaded section of each of the electrode plates represents the tab (e.g., 1 inch wide) welded to the electrode plate. The tab can be, for example, copper or copper plated nickel. A positive terminal is formed from aligned tabs of the positive electrode plates and a negative terminal is formed from aligned tabs of the negative electrode plates.
As illustrated in FIGS. 2 and 3 , the rechargeable flat plate electrode cell of the present disclosure exhibits improved performance over commercially available ZnMn round bobbin consumer cells. In particular, FIG. 2 shows the improvements of the rechargeable flat plate electrode cell of the present disclosure over commercially available ZnMn round bobbin consumer cells (i.e., “Baseline Round Bobbin” and “Improved Round Bobbin”) as well as a cell as disclosed in CA 2 389 907 A1 in terms of Cell Capacity (expressed as a percentage of initial capacity) Versus Discharge Rate (expressed as a percentage of one hour capacity), while FIG. 3 shows the improvements of the rechargeable flat plate electrode cell of the present disclosure over commercially available ZnMn round bobbin consumer cells (i.e., “Baseline Round Bobbin” and “Improved Round Bobbin”) as well as a cell as disclosed in CA 2 389 907 A1 in terms of Cell Capacity (expressed as a percentage of initial capacity) versus Cycles/Life (expressed as full charge/discharge at C/16 and Room Temperature). As can be seen from FIG. 2 , the rechargeable flat plate electrode cell of the present disclosure has a capacity of greater than 50% of initial capacity, and in particular, a capacity of greater than 80% of initial capacity, at a discharge rate of greater than or equal to 50% of one hour capacity. As can be seen from FIG. 3 , the rechargeable flat plate electrode cell of the present disclosure has a capacity of greater than or equal to 60% of initial capacity at greater than or equal to 25 cycles at room temperature.
With further reference to FIG. 3 , the Baseline Round Bobbin was tested for seven cycles, the Improved Round Bobbin was tested for sixty-five cycles, and a cell as disclosed in CA 2 389 907 A1 was tested for one hundred cycles. The rechargeable flat plate electrode cell of the present disclosure was tested for twenty-five cycles, with predicted results shown for up to 200 cycles.
Additionally performance characteristics of the rechargeable flat plate electrode cell of the present disclosure can include capacity of greater than 5 Ahr, cycle life exceeding 200 cycles at 80% DOD above 50% initial capacity, power exceeding C/2 rate to 1 V at 50% initial capacity and 2C rate to 1V at 25% initial capacity, energy density exceeding 90 Whr/kg, and power density exceeding 180 W/kg. DOD, or depth of discharge, is a measure of how much energy has been withdrawn from a battery, expressed as a percentage of full capacity. C/2 rate refers to a discharge rate of 50% of one hour capacity.
The rechargeable flat plate electrode cell of the present disclosure can be utilized in a vehicle for starting a internal combustion engine, or in a more portable format can be used in power tools, cell phones, computers, and portable electronic devices.
The following illustrative examples are intended to be non-limiting.
EXAMPLES
With regard to formation of the flat plate anode electrodes, 360 grams of Zn, 72 grams of ZnO, and 59.88 grams of 2% CMC gel were mixed to form a paste comprising 83.1 weight % zinc active material (i.e., Zn), 16.6 weight % solid zinc oxide, and 0.27 weight % polymeric binder. The paste was applied to one side of copper plated nickel foam and pressed/worked in. The copper was plated on the nickel foam via copper plating 1A for 30 minutes. Water was evaporated from the paste, and the dried pasted foam was pressed to approximately 50% of its original thickness. A 0.15 inch strip at the top of each flat plate anode electrode was coined for attachment of a tab. Further details of formed flat plate anode electrodes can be found in Table 1, below. With regard to the capacity calculations in Table 1, the capacity of 0.625 g Zn is 512 mAh.
With regard to formation of the flat plate cathode electrodes, 41.90 grams of 2% CMC gel and 100 grams of cathode powder ground down to 1/10 th of the initial particle size were mixed to form a paste. The cathode powder comprised electrolytic manganese dioxide, 7.5 weight % graphite/carbon black, 5 weight % polymeric binding agent, 5 weight % barium compound, and 5 weight % hydrogen recombination catalyst, and is pressed to form high density initial particles. The 2% CMC gel provided an additional 1 weight % polymeric binding agent to provide a paste with a total of 6 weight % polymeric binding agent. The paste was applied to one side of nickel foam having a weight basis of 0.255 g/in 2 . Water was evaporated from the paste, and the dried pasted foam was pressed to approximately 50% of its original thickness. A 0.15 inch strip at the top of each flat plate cathode electrode was coined for attachment of a tab. Further details of formed flat plate cathode electrodes can be found in Table 2, below.
TABLE 1
Anode Design
Sized
Thickness
(Substrate
Paste
Sized
Sized
and
Paste Weight/
Weight
Width
Length
Weight
Width
Length
Paste)
Sized Area
Substrate
(g)
(in)
(in)
(g)
(in)
(in)
(in)
(g/in 2 )
A · h/in 2
A · h/in 3
1
2.669
2.52
2.37
13.098
2.54
2.50
0.0370
2.063
1.406
37.988
2
2.697
2.52
2.37
13.258
2.54
2.52
0.0370
2.071
1.411
38.147
3
2.634
2.53
2.38
15.061
2.54
2.53
0.0380
2.344
1.597
42.027
4
2.679
2.52
2.35
13.833
2.53
2.47
0.0370
2.214
1.508
40.767
5
2.631
2.53
2.38
15.144
2.55
2.55
0.0380
2.329
1.587
41.763
6
2.699
2.50
2.39
14.534
2.53
2.50
0.0370
2.298
1.566
42.319
7
2.375
2.54
2.36
15.238
2.56
2.49
0.0380
2.390
1.629
42.867
8
2.360
2.54
2.36
14.495
2.55
2.48
0.0370
2.292
1.562
42.212
9
2.339
2.52
2.38
15.492
2.55
2.48
0.0380
2.450
1.669
43.929
10
2.308
2.53
2.38
16.602
2.55
2.50
0.0390
2.604
1.775
45.502
11
2.618
2.53
2.37
14.380
2.54
2.51
0.0360
2.256
1.537
42.694
TABLE 2
Cathode Design
Paste
Sized
Weight/
Sized
Thickness
Sized
Coated
Paste
Sized
Sized
Coated
(Substrate
Coated
Weight
Width
Length
Thickness
Length
Weight
Width
Length
Length
and Paste)
Area
Substrate
(g)
(in)
(in)
(in)
(in)
(g)
(in)
(in)
(in)
(in)
(g/in 2 )
mAh/in 2
1
1.168
2.53
1.81
0.058
1.54
4.492
2.57
2.02
1.77
0.0250
0.988
216
2
1.170
2.52
1.82
0.054
1.56
4.129
2.57
1.97
1.72
0.0235
0.934
205
3
1.141
2.50
1.79
0.050
1.56
3.555
2.52
1.90
1.66
0.0225
0.850
186
4
1.149
2.49
1.81
0.049
1.57
3.577
2.54
1.94
1.69
0.0230
0.833
182
5
1.143
2.49
1.80
0.048
1.58
3.756
2.54
1.94
1.72
0.0230
0.860
188
6
1.138
2.48
1.80
0.050
1.58
3.815
2.53
1.94
1.72
0.0235
0.877
192
7
1.139
2.51
1.78
0.052
1.55
4.328
2.56
1.96
1.75
0.0235
0.966
212
8
1.154
2.50
1.81
0.050
1.56
4.067
2.56
1.96
1.69
0.0235
0.940
206
9
1.152
2.51
1.80
0.050
1.58
4.041
2.56
1.94
1.74
0.0230
0.907
199
Many modifications of the exemplary embodiments disclosed herein will readily occur to those of skill in the art. Accordingly, the rechargeable flat plate electrode cell of the present disclosure is to be construed as including all structure and methods that fall within the scope of the appended claims. | Provided is a flat plate electrode cell, comprises positive electrode plates and negative electrode plates. The positive electrode plates each comprise manganese and compressed metal foam. The negative electrode plates each comprise zinc and compressed metal foam. Both the positive and negative electrodes can have alignment tabs, wherein the flat plate electrode cell can further comprise electrical terminals tanned from the aligned tabs. The rechargeable flat plate electrode cell of the present disclosure, formed from compressed metal foam, provides both low resistance and high rate performance to the electrodes and the cell. Examples of improvements over round bobbin and flat plate cells are current density, memory effect, shelf life, charge retention, and voltage level of discharge curve. In particular, the rechargeable flat plate electrode cell of the present disclosure provides longer cycle life with reduced capacity fade as compared with known round bobbin and flat plate cells. | 8 |
CROSS-REFERENCE TO RELATED APPLICATIONS
This application is a division of application Ser. No. 11/015,534 filed on Dec. 18, 2004, now U.S. Pat. No. 7,224,047 issued on May 29, 2007.
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to packages for semiconductor devices (e.g., integrated circuit chips, discrete devicc chips, or both) and, more particularly, to such packages designed to reduce leakage, for example, of encapsulant from the package or of harmful substances (e.g., vapors, liquids, particles) from the ambient into the package.
2. Discussion of the Related Art
In the semiconductor device industry it is common to fabricate device packages from a metallic base and plastic or other polymer sidewalls. One of the many potential package types is known as an open cavity package, which is commonly used in applications where high thermal loads must be handled including, but not limited to, power devices (e.g., radio frequency, laterally diffused MOSFETs or RFLDMOSFETs). The most common open cavity package includes a high thermal conductivity base, ceramic side walls and embedded leads. These packages are typically of the hermetic or semi-hermetic variety. In both varieties the semiconductor device or chip is connected to the base and the leads, and the chip is protected from the outside environment by a substantially leak-tight sealed lid. As such, there is no requirement for semiconductor device encapsulant for environmental protection. For lower cost applications, the ceramic side walls of the package can be replaced with plastic. Many of the open cavity plastic packages are non-hermetic by design. In this case the semiconductor device must be encapsulated so that unwanted environmental degradation does not occur. The best environmental protection is achieved when the entire cavity (including the semiconductor device, wire bonds, package leads, and package base) is filled with a protective encapsulant such as silicone.
We have found that non-hermetic plastic packages fabricated in this or similar fashion have a number of problems associated with encapsulant leaking out of the cavity during the cavity fill process. Often the encapsulant leaking problem is not present in as-received open cavity packages. However, after die attach and wire bonding, when the packages are typically filled with encapsulant, we have observed that encapsulant does leak out at the plastic-to-metal interfaces of the package. This leakage results primarily from degradation of the interfaces between the different parts of the package, which in turn results from differences in the thermal expansion coefficients of the base, lead frame and sidewall materials as well as from less than ideal design. The difference in thermal expansion between the plastic side walls and the metal base and metal leads causes the plastic and metal to separate in one or more locations along the bond line. This separation provides leakage paths that allow the encapsulant to flow from the cavity to the outside surfaces of the package.
Thus, a need remains in the art for a semiconductor device package that reduces the leakage of encapsulant from the filled cavity.
In addition, these leaky interfaces also permit harmful substances (e.g., moisture, solvents, air-born particles) from the ambient to enter the package, where they can have a deleterious effect on device operation or package integrity.
Thus, a need remains in the art for a semiconductor device package that reduces the leakage of such harmful substances from the ambient into the package.
BRIEF SUMMARY OF THE INVENTION
In accordance with one aspect of our invention, a semiconductor device package comprises a container including a base and sidewalls of materials having different thermal expansion coefficients. The base is configured to support a semiconductor device chip, and a lead frame extends through at least one of the sidewalls. The package is characterized in that a portion of the lead frame within the sidewall has at least one aperture penetrating into the lead frame. The sidewall material extends into (e.g., molds around) the aperture, thereby forming a strong interfacial bond that provides a low leakage, sidewall-lead-frame interface.
In accordance with another aspect of our invention, the base has a reentrant feature that is positioned within the thickness of at least one of the sidewalls. This feature acts to engage or capture the side wall in such a way as to provide a strong, low leakage base-sidewall interface.
In accordance with yet another aspect of our invention, the top surface of the base has a groove that is positioned within the thickness of at least one of the sidewalls and engages the at least one sidewall, thereby forming a low leakage base-sidewall interface.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING
Our invention, together with its various features and advantages, can be readily understood from the following more detailed description taken in conjunction with the accompanying drawing, in which:
FIG. 1 is a schematic, cross sectional view of a semiconductor device package in accordance with one embodiment of our invention;
FIG. 2 is a schematic, top view of a lead-frame-sidewall interface having horseshoe features in accordance with another embodiment of our invention;
FIG. 3 is a cross-sectional view taken along line A-A of FIG. 2 for the case where the feature extends entirely through the thickness of the lead frame;
FIG. 4 is a cross-sectional view taken along line A-A of FIG. 2 for case where the feature is a depression in the lead frame;
FIG. 5 is a schematic, top view of a lead-frame-sidewall interface having oval features in accordance with another embodiment of our invention;
FIG. 6 is a schematic, top view of a lead-frame-sidewall interface having rectangular features in accordance with one more embodiment of our invention;
FIG. 7 is a schematic, top view of a lead-frame-sidewall interface having triangular features in accordance with another embodiment of our invention; and
FIG. 8 is a cross-sectional view of a reentrant feature formed on the base in accordance with an illustrative embodiment of our invention.
DETAILED DESCRIPTION OF THE INVENTION
With reference now to FIG. 1 , we show a semiconductor device package 10 for housing one or more semiconductor device chips 18 ; e.g., integrated circuit chips, discrete device chips, or both. The package 10 is formed by a container having a thermally conducting (e.g., metallic) base 12 , which often serves as a heat sink and an electrical connection, and an electrically insulating (e.g., plastic or other polymer) sidewalls 14 . An electrically conducting (e.g., metallic) lead frame 16 extends through at least one of the sidewalls 14 in order to facilitate making electrical contact to the chip 18 , which is mounted on the base 12 . To this end, electrical conductors 20 (typically wire bonds) are connected between terminals on the interior ends of the lead frame 16 and terminals on the chip 18 . The chip 18 and the conductors 20 are covered by a protective encapsulant 22 , which illustratively fills the container and is itself covered by a lid 24 . Illustratively, the encapsulant includes single or multiple layers of silicone and/or a hard material such as HYSOL® FP4470 Encapsulant, which is commercially available from the electronics division of Henkel Loctite Corporation located in Industry, Calif.
This type of open cavity package is typically formed in an insert mold cavity, where the base and lead frame are inserted into the mold cavity and plastic (or other polymer) is molded around these metallic components.
The lead frame, as is well known in the art, is designed to accept wire bonds from the semiconductor chip and to carry electrical signals between the chip and an external electrical circuit.
The metallic materials of the base and lead frame do not adhere well to the plastic material of the sidewalls and have thermal expansion coefficients different from that of the sidewall material, which in prior art designs tends to make leaky interfaces 30 between the lead frame 16 and the sidewalls 14 and leaky interfaces 40 between the base 12 and the sidewalls 14 . More specifically, during thermal excursions of the package (e.g., during high temperature processing steps, such as the common step of using eutectic AuSn solder, which melts at approximately 280° C., to bond the chip 18 to the base 12 ), the base and sidewall, and the lead frame and sidewall, both expand. Because the thermal expansion of the side wall is different from that of metallic base and lead, the metal exerts a force that deforms the plastic. Often this deformation is non-elastic. More specifically, whereas the metallic base and lead frame naturally return to their original shapes upon cooling, the plastic side wall does not, resulting in a gap between the metal and the plastic. Such gaps undesirably allow encapsulant to leak out. In addition, liquids, vapors and/or air-born particles can also enter the package cavity via these gaps. Both types of leakage can degrade the device reliability.
In accordance with one aspect of our invention, as shown in FIGS. 2-6 , the problem of a leaky lead-frame-sidewall interface 30 is addressed by forming fillable features 16 . 2 - 16 . 7 in the lead frame 16 ; that is, the features may be, for example, apertures 16 . 2 , 16 . 3 ( FIG. 2 , FIG. 3 , respectively), which are etched through the entire thickness lead frame, or depressions 16 . 4 ( FIG. 4 ; only one is shown for simplicity), which are stamped into the lead frame. For purposes of illustration, the depression 16 . 4 is shown only in the top surface of the lead frame, but it could also be located in the bottom surface of the lead frame or in both surfaces. The features may take on myriad geometric shapes such as, for example, circular (e.g., a linear array of tandem, oppositely facing semicircles 16 . 2 - 16 . 4 as in FIGS. 2-4 ; tandem stadium-like shapes or ovals 16 . 5 as in FIG. 5 ), rectangular (e.g., parallel rows of offset rectangles 16 . 6 as in FIG. 6 ), triangles (e.g., interlocking diamonds and bowties 16 . 7 as in FIG. 7 ), or any suitable combination of such shapes. The number of such features utilized is a matter of design choice; only two or three are shown in FIGS. 2 and 5 - 7 for simplicity. The features may be arranged head-to-tail, as the semicircles 16 . 2 of FIG.2 . Alternatively, the semicircles may “interlock” to block line-of-sight leakage paths between adjacent horseshoes and across the sidewall. Line-of-sight leakage paths are blocked, for example, in the features illustrated by the rectangles and diamond-bowtie features of FIGS. 6-7 .
After the features are formed, the sidewall 14 is molded around the lead frame 16 so that material of the sidewall fills the features, thereby engaging the lead frame and forming a relatively leak-free interface 30 . The features 16 . 2 - 16 . 7 have an additional advantage; they inhibit unwanted movement of the lead frame within the package.
In accordance with another aspect of our invention, as shown in FIG. 1 , the problem of a leaky base-sidewall interface 40 is addressed by forming reentrant features 12 . 1 (e.g. hook-like flanges) on the outer edges of the base 12 . After the reentrant feature 12 . 1 is formed, the sidewall is molded around the base (at the same time that it is molded around the lead frame 16 ). The molding process, of course, means that the base and sidewalls are at an elevated temperature. During the cooling cycle, the reentrant feature 12 . 1 of the metallic base 12 engages the plastic sidewall 14 , thereby pulling the sidewall back into place and forming a relatively leak-free interface 40 .
In general, the reentrant feature 12 . 1 is formed on at least one edge of the base 12 , but preferably on all such edges to ensure that a relatively leak-free interface 40 is formed around the entire package. Moreover, the reentrant feature may be continuous along each edge, or it may be segmented. The latter design has the advantage that it forms “teeth” that provide better locking of the base to the sidewalls. Although the reentrant feature 12 . 1 is depicted as being located at the top surface of the base, it could be positioned lower.
In addition, in accordance with yet another aspect of our invention, the problem of a leaky base-sidewall interface 40 is addressed by forming grooves 12 . 2 in the top surface of the base 12 and under the sidewalls 14 . The groove should be formed with sharp (rather than rounded) top edges, since the former inhibit the encapsulant 22 , before it is cured (i.e., when it is still in low-viscosity gel form) from leaking out through interface 40 . In general, the groove 12 . 2 is formed along at least one edge of the base 12 , but preferably on all such edges to ensure that a relatively leak-free interface 40 is formed around the entire package. The shape of the groove is otherwise not critical; for example, it can be V-shaped (as shown in FIG. 1 ) or it can be rectangular (not shown).
It is to be understood that the above-described arrangements are merely illustrative of the many possible specific embodiments that can be devised to represent application of the principles of the invention. Numerous and varied other arrangements can be devised in accordance with these principles by those skilled in the art without departing from the spirit and scope of the invention. In particular, each of the three design features discussed above may be used separately or in any combination thereof, but preferably all three are used together to lock the polymer to the metal, thereby maximizing the reduction in leakage of encapsulant from the package and/or the leakage of harmful substances from the ambient into the package.
EXAMPLE
This example describes the fabrication of a package for RFLDMOS (i.e., radio frequency, laterally diffused, metal-oxide-semiconductor) ICs, in accordance with one embodiment of our invention. Various materials, dimensions and operating conditions are provided by way of illustration only and, unless otherwise expressly stated, are not intended to limit the scope of the invention. This type of package illustratively contains six chips: two chips that function as active ICs (i.e., high power RFLDMOS transistors) and four that function as passive ICs (i.e., capacitors).
The container 12 had overall dimensions of 810 mils in length, 385 mils in width, and 99 mils in height. The sidewalls 14 and lid 24 were made of a liquid crystal polymer (LCP) material (e.g., VECTRA ® S-135 LCP Material, which is commercially available from Ticona located in Florence, Kentucky). The sidewalls were 72.5 mils thick in the region where the lead frame extended through the sidewalls, whereas the lid 24 had overall dimensions of 810 mils in length, 384 mils in width, and 43 mils in thickness. The base was made of copper (e.g., CDA 194) and had overall dimensions of 810 mils in length, 325 mils in width, and 50 mils in height/thickness.
The lead frame 16 was made of copper (e.g., CDA 151) and the portion extending through each of two opposite sidewalls had overall dimensions of about 600 mils in length and 5 mils in thickness. The width, which is measured in the same dimension as the sidewall width, is unspecified and not critical since the lead frame extends on both sides of the sidewalls. Five stadium-like or oval features were formed in tandem in each of the two lead frames 16 . Thus, each stadium feature included two semicircular features that faced one another. The stadium features were about 55 mils in length and were spaced on 92.5 mil centers. Each semicircular feature had about a 10 mil radius.
The reentrant feature 12 . 1 was formed along the entire length and width of the base 12 . The feature 12 . 1 had the reentrant shape shown in FIG. 8 and had the following approximate dimensions: d 1 =20 mils, d 2 =73 mils, d 3 =35 mils, d 4 =8 mils, d 5 =100 mils, θ 1 =28°,and θ 2 =18°.
The groove 12 . 2 was also formed along the entire length and width of the base 12 . It was stamped into the base, had a V-shape with a rounded bottom in cross-section as shown in FIG. 1 , and had the following approximate dimensions: 15 mils in maximum width and 10 mils in depth, with the sides of the V making a 60° angle with one another.
The encapsulant 22 was a single layer of cured silicone gel and was about 40 mils thick. The gel, which was purchased from Dow Corning, Midland, Mich. and was identified as HIPEC® Q3-6646 Semiconductor Protective Coating, was oven cured at a temperature of about 150° C. for about 120 min. | A semiconductor device package comprises a container including a base and sidewalls. The base is configured to support a semiconductor device chip, and a lead frame extends through at least one of the sidewalls. A portion of the lead frame within the sidewall has at least one aperture penetrating into the lead frame. The sidewall material extends into the aperture, thereby forming a strong interfacial bond that provides a low leakage, sidewall-lead-frame interface. The base has a reentrant feature that is positioned within the thickness of at least one of the sidewalls and engages the at least one sidewall, thereby forming a low leakage base-sidewall interface. The top surface of the base has a groove that is positioned within the thickness of at least one of the sidewalls and engages the at least one sidewall, thereby enhancing the low leakage base-sidewall interface. | 7 |
FIELD OF THE INVENTION
[0001] This invention relates to an endotoxin-adsorbent for preventing and treating autoimmune diseases, such as rheumatoid arthritis, by removing endotoxin in the gastrointestinal tract.
RELATED ARTS
[0002] Lipopolysaccharide (LPS), a component of the outer cell membrane of gram-negative bacteria, is known as endotoxin; and the lipid A component is the fatal toxic domain of LPS (Microbiology. David B D, Dulbecco R, Eisen H N, Harold S, Ginsberg H S, Barry W A. Harper International Edition 615-617, 1970).
[0003] Endotoxin has a variety of physiological and pathological effects and causes endotoxin shock in animals within one hour if enough amounts of LPS were injected. Since it causes fever even at low dose, it is also known as a pyrogen. Therefore, the contamination of endotoxin in medical products such as injection products used as a non-oral administration is strictly prevented.
[0004] Since large numbers of a variety of gram-negative microorganisms, such as E. coli , invariably reside in the gastrointestinal tract of animals and humans, a large amount of endotoxin consistently presents in the gastrointestinal tract. However, animals and humans do not suffer by fever in general, indicating that endotoxin is barely absorbed from intestinal walls due to the large molecular size or due to mucosal immune barrier systems such as IgA antibody barrier on intestinal walls.
[0005] The immune system is one of the major self-defense systems for host to keep homeostasis by recognizing and preventing the invasion of foreign substances such as microorganisms as well as the growth of abnormal cells such as cancer cells, and by excluding them from the body. However, once this system is destructed by unknown reasons, the immune system starts to attack self-components, and as a consequence, induces a variety of intractable diseases, so called “autoimmune diseases”. The following diseases are known as autoimmune diseases: rheumatoid arthritis, autoimmune hepatitis, autoimmune nephritis, autoimmune labyrinthitis, autoimmune encephalomyelitis, autoimmune chronic thyroiditis, type I diabetes, systemic lupus erythematosus, polydermatomyositis, psoriasis, Sjorgren syndrome, ulcerative colitis, Crohn's disease, and Guillain-Barre syndrome.
[0006] Rheumatoid arthritis is an example of a typical autoimmune disease. Since large numbers of patients suffer this painful disease and their quality of life in society is interfered by their limited function, this disease has been given many social attentions. The majority of patients with rheumatoid arthritis are forced to be confined to bed rest as the progress of arthritis, such as articular destruction, joint deformity, mobility impairment and pain increases. Currently, autoimmune diseases are treated with non-steroidal anti-inflammatory drugs, anti-inflammatory steroids, immune suppressants, and anti-cytokine antibodies such as Remicade. These therapeutic agents only suppress abnormal immune systems and inflammatory reactions, and are used to target specific symptoms, but not intended to cure the disease. Although several hypotheses for the causes of rheumatoid arthritis have been proposed, the etiology and the pathology of this disease remain unknown.
[0007] Based on the analysis of auto-antibodies in sera and cartilages from patients with rheumatoid arthritis, we have reached a hypothesis that the chronic abnormal absorption of mimic antigens and bacterial toxins from gastrointestinal tract due to the increased mucosal permeability is the fundamental, common disorder of autoimmune diseases. This hypothesis was proved by the following arthritis models in experimental animals. We administered purified heterologous type II collagen with and without the use of LPS to mice by oral route, and successfully induced three types of chronic arthritis in mice. Most importantly, bacterial toxins, such as endotoxin, are not only capable of disturbing immune homeostasis by stimulating host immune systems non-specifically, but also capable of inducing inflammatory diseases such as arthritis. Based on these observations, the inventors of this invention focused on the pathogenic roles of LPS, which is a dominant bacterial toxin produced by intestinal flora in large quantities, and reached a hypothesis that autoimmune diseases could be prevented and treated by blocking the absorption of excess amounts of LPS from gastrointestinal tract by using an endotoxin-adsorbent.
[0008] To begin, mice were administered chick type II collagen by oral route for more than 10 weeks. Mice developed antibodies to chick type II collagen, which cross-react to autologous type II collagen, and as a consequence, mice developed clinically apparent arthritis (Terato K, Ye X Y, Miyahara H, Cremer M A, and Grifiths M M. Induction of auto-immune arthritis in DBA/1 mice by oral administration of type II collagen. Br. J. Rheum. 35:828-838, 1996).
[0009] Since autoantibodies to cartilage are not always capable of inducing arthritis in experimental animals and humans, it was assumed that secondary factor(s) is involved in the induction of arthritis in patients with rheumatoid arthritis. Although a variety of bacterial toxins are considered as a potential secondary pathogenic factor, it is most likely that endotoxin will play the dominant pathological role in the majority of patients with autoimmune diseases, because endotoxin is most widely and commonly existing at high levels in the gastrointestinal tract. In order to test this possibility, mice were injected with a non-arthritogenic dose of monoclonal anti-type II collagen antibody cocktail and then received LPS by IP and oral route. The control mice receiving anti-type II collagen antibody alone did not develop arthritis, whereas, both groups of mice receiving LPS by IP and by oral administration developed severe arthritis, indicating that environmental factors such as LPS play important pathological roles in autoimmune diseases (Terato K, Harper D S, Griffiths M M, Hasty D A, Ye X Y, Cremer M A and Seyer J S. Collagen-induced arthritis: Synergistic effect of E. coli lipopolysaccharide bypass epitope specificty in the induction of arthritis with monoclonal antibodies to type II collagen. Autoimmunity 22:137-147, 1995).
[0010] It has been known that endotoxin is not only involved in rheumatoid arthritis but also involved in a variety of autoimmune diseases such as autoimmune encephalomyelitis (Nagai A et al. J. Immunol. 175:959-966, 2005), lupus lung injury (Chae B S et al. Arch Pharm Res 29:302-309, 2006), autoimmune thyroiditis (Damotte D et al. Eur Cytokine Netw 14:52-59, 2003), primary biliary liver cirrhosis (Ballet E et al. J. Autoimmun 22:153-158, 2004), and Guillain-Barre syndrome (Yuki N et al. Proc Natl Acad Sci USA 101:11404-11409, 2004).
[0011] The inventors of this invention have shown previously that oral administration of anti-LPS antibodies effectively suppressed the development of arthritis in this arthritis model (JP-A2006-151914). This evidence suggests strongly that the removal of endotoxin from the gastrointestinal tract is one of the best strategies for treatment of autoimmune diseases.
[0012] There are a variety of difficulties in mass-producing antibody for medical use, in addition to the high production cost. Antibody, which is a protein, is heat labile, and tends to loose biological activity during processing. Furthermore, antibody administered by oral route will be less effective because of its degradation by digestion enzymes in the gastrointestinal tract. Therefore, it is desired to develop a new effective endotoxin antagonist, which is heat stable, easy to mass-produce with low costs, and is safe for humans.
[0013] The contamination of endotoxin in injectable products must be removed completely, since even a minor contaminant of endotoxin induces adverse effects such as fever in patients. In order to remove endotoxin from medical products, several adsorbents specific to endotoxin have been used. Synthetic fibers, fabrics and particles covalently bound by a substance that has high binding affinity to endotoxin, have been used. By contacting these adsorbents with objective solution, endotoxin contaminated in the solution can be removed effectively. Several endotoxin-adsorbents, such as Affi-Prep Polymixin (BioRad, USA) and Toraymyxin (Toray Medicals, Japan), JP-A 11-335396 and JP-A 2002-263486, are currently used to remove endotoxin contaminated in injectable products and others.
SUMMARY OF THE INVENTION
[0014] The present invention provides a non-digestible and non-absorbable endotoxin-adsorbent, used for oral administration, comprising of particles of not more than 1% with a diameter not more than 5 μm, and particles more than 90% with a diameter not more than 50 μm, based on a volume-based size distribution analysis.
[0015] Futhermore, this invention also provides a formulation of the endotoxin-adsorbent or an agent for preventing and treating autoimmune diseases, a method for prevention and treatment of patients with autoimmune diseases by administering the endotoxin-adsorbent, and methods for manufacturing of endotoxin-adsorbents used for the prevention and treatment of autoimmune diseases.
DETAILED DESCRIPTION OF THE INVENTION
[0016] Endotoxin-adsorbent used for the treatment of patients with autoimmune diseases is required the following criteria: 1) a high endotoxin-binding capacity, 2) suitable physiological features for oral administration usage and 3) high margin of safety without any adverse effects. The number of microorganisms residing in the human gastrointestinal tract is believed to be approximately 100 trillion, and the number of endotoxin-containing microorganisms among these bacteria is also massive. Therefore, in order to remove large portions of endotoxin in the gastrointestinal tract, endotoxin-adsorbent must have high binding capacity of endotoxin.
[0017] In order to satisfy these requirements, new endotoxin-adsorbents, which have high endotoxin-binding capacity, high margin of safety, and suitable physical features for oral administration use, are provided in this invention.
[0018] The toxic core of an endotoxin molecule is located in the Lipid A region. This invention consists of a Lipid A-binding substance and insoluble carrier particles in order to adsorb and eliminate large amounts of endotoxin from the gastrointestinal tract into feces by oral administration, for preventing and treating autoimmune diseases such as rheumatoid arthritis.
[0019] The endotoxin adsorbent suitable for the usage of above purposes is as follows:
1. Endotoxin binding capacity of the particles is not less than 10×10 6 endotoxin units (EU) per 1 g of dry particles in in vitro test tube assay. 2. Endotoxin binding capacity of the particles is not less than 50×10 6 endotoxin units (EU) per 1 g of dry particles in in vitro test tube assay. 3. Endotoxin binding capacity of the particles is not less than 100×10 6 endotoxin units (EU) per 1 g of dry particles in in vitro test tube assay. 4. The endotoxin-adsorbent consists of an endotoxin-binding substance and carrier particles. 5. The endotoxin-adsorbent consists of a Lipid A binding substance, that is capable of binding endotoxin. 6. The endotoxin-adsorbent, which is a Lipid A binding substance, is polymixin B 7. The endotoxin-adsorbent consists of a Lipid A binding substance, polymixin B, and carrier particles which is a weakly acidic cation exchange resin with carboxy residue. 8. The methods for prevention and treatment of autoimmune diseases by administrating pharmacologically effective doses of endotoxin-adsorbent to patients by oral route.
[0028] Several materials such as polymixin B or a peptide antibiotic, and endotoxin-binding peptides (JP-A 11-335396, JP-A 2002-263486, JP-A 2002-311029, JP-A 2004-292357 and JP-A 2002-512140) have been known as Lipid A binding substances. All these materials can be used for the purpose of this invention.
[0029] The carrier of endotoxin-binding substance is desired to be small particles or powder suitable and convenient for oral administration usage. A variety of polysaccharides and their derivatives, such as cellulose, agarose, mannan, glucan, and chitin, or variety of synthetic polymers, such as polyacrylate, polystyrene, polypropylene, polyamide, and polyvinyl, can be used as the carrier of an endotoxin-binding substance.
[0030] There is no definite method required to conjugate Lipid A binding substance to the carrier particles. The cross-linkers, which have been widely used for immobilizing enzymes onto the solid surfaces like water soluble carbodiimides such as ECDI, hexamethylene diisocyanate, propyleneglycol di-glycidylether which contain 2 epoxy residues, and epichlorohydrin, can be used.
[0031] The features of Lipid A binding substance-carrier complexes are desired to be non-toxic, non-absorbable, and non-digestible by digestion enzymes and by microorganisms and resistant to other intestinal components such as gastric acid. “Non-digestible” means resistant to both digestion enzymes of animals and enzymes produced by microorganisms.
[0032] The microorganisms residing in the gastrointestinal tract possess enzymes which are capable of digesting cellulose and other substances that are resistant to digestion enzymes of animals (Kopecny J et al. Detection of cellulolytic bacteria from the human colon. Folia Microbiol (Praha) 49:175-7, 2004, Nakajima N et al. Dietary-fiber-degrading enzymes from a human intestinal Clostridium and their application to oligosaccharide production from nonstarchy polysaccharide using immobilized cells. Appl Microbiol Biotechnol 59: 182-9, 2002). Therefore, in this invention, the materials used as a carrier of LPS-binding substance should be restricted to materials, which are resistant to bacterial digestion, and usage of polysaccharides such as cellulose, agarose, mannan, glucan, and chitin as a carrier of an endotoxin-binding substance should be excluded.
[0033] Compared to naturally occurring polymers, synthetic polymers are generally resistant to digestion enzymes secreted into gastrointestinal tract of animals and even to various bacterial enzymes. Therefore, it is desired to choose a synthetic polymer as a carrier of lipid A binding substance. In fact, synthetic polymers such as polystyrene sulfonate calcium and anion exchange resin are widely used as a potassium adsorbent and as a cholesterol adsorbent for treatment of patients with high potassium and high cholesterols, respectively.
[0034] The particle size of endotoxin-adsorbent is an important factor that should be considered, since it has been known that small size particles, such as yeast, with less than 5 μm in diameter, are phagocytized by M cells, which reside on the surface of Peyer's patches scattered along small and large bowel regions (Gerbert A. et al. M cells in Peyer's patches of the intestine. Int Rev Cytol. 167:91-159, 1996). Therefore, the particle size of endotoxin-adsorbent not more than 5 μm in a diameter is excluded according to the specification of polystyrene sulfonate calcium defined in Japanese Pharmacopoeia.
[0035] The molecular weight of endotoxin is more than 10,000 daltons, and assumed to bind mainly on the surfaces of entotoxin-adsorbent particles rather than the inside of particles. Therefore, if the particle size is smaller, the endotoxin binding capacity is larger due to larger surface area per unit weight of particles. This evidence is shown in EXAMPLE 12.
[0036] There are two classes of fine grinding techniques, dry and wet methods. Impact method, screen method, grind method and others are known as dry methods, whereas catalyst-stirring method is an example of a typical wet method. There are several other methods, but there is no limitation in the methods for grinding the particles of endotoxin-adsorbent, and any of these methods can be used for preparing fine powder or small particles of endotoxin-adsorbent.
[0037] The particle size of endotoxin-adsorbent was determined based on particle size distribution method. The particle distribution analysis was performed according to “The method for determining particle size distribution. Method 1: Microscopic method” in the second supplement of the general test procedures, section 65, Japanese Pharmacopoeia, 13 th Issue. The 50% particle size (μm) was explained as the diameter of particles of the corresponding values of accumulative volume of particles is 50%.
[0038] LPS binding capacity of endotoxin-adsorbent in a test tube was determined according to the method described in “endotoxin test procedures” in Japanese Pharmacopoeia, in addition to a simple assay method of LPS by measuring OD values, which was developed during this invention. The experimental procedures and results are shown in EXAMPLE10 and 11 in detail.
[0039] The therapeutic effect of endotoxin-adsorbent on autoimmune diseases can be determined in mouse arthritis model as described in our previous invention, JP-A 2006-151914. Briefly, arthritis can be induced in 100% of mice by IP injection of enough amounts of anti-type II collagen monoclonal antibody cocktail (Chondrex Inc., Redmond, Wash., USA) within 3 days (Terato K et al. Induction of arthritis with monoclonal antibodies to collagen. J. Immunol. 148:2103-2108, 1992). By reducing the dose of monoclonal antibody cocktail to 2 mg, all mice remained normal without developing arthritis. However, oral administration of 3 mg of LPS on 3 consecutive days from day 0, day 1, day 2 and day 3 into these mice induced clinically apparent arthritis, which reached the peak on day 6-7. Furthermore, one group of mice was co-administered with indomethasin and ovoinhibitor, a protease-inhibitor purified from egg white. The combination of indomethasin and ovoinhibitor was used to increase the mucosal permeability of gastro-intestinal mucosa. In these mice, the effect of LPS was more significant, and more severe arthritis was induced by oral administration of a same dose of LPS. Using this arthritis model induced by a combination of monoclonal antibody and LPS, the therapeutic effect of endotoxin-adsorbent can be determined. The benefit of this model is multifold: time of experimentation is short compared with authentic collagen-induced arthritis model, the standard deviation of severity of arthritis among individual mice is much less, and the effect of LPS-adsorbent is clearly determined.
[0040] Since the endotoxin-adsorbent is used as a therapeutic for human patients by oral administration, various formulas, which are currently employed in medicines used by oral administration, can be applied: for example, powdered or suspended powdered form, capsule, tablet and solution. These formulas can be provided using authentic methods by mixing the endotoxin-adsorbent with various vehicles and additives within a range that is acceptable with respect to pharmaceutical guidelines.
[0041] The endotoxin-adsorbent can be administered orally at 10 mg −10 g per adult by a single or three administrations per day.
EXAMPLES
[0042] The individual examples of this invention are described in detail in the following sections, but the invention is not to be considered limited to these examples as described below.
Example 1
Epoxyacryl Resin-Polymixin B Conjugate, RPMB
[0043] Polymixin B sulfate (3 million units, Maruko Pharmaceuticals) was dissolved in 200 mL of 0.1M NaCl, and then pH was adjusted to 8 by adding NaOH. Four grams of polyacryl resin with epoxy residue (Amberzyme, Rohm and Haas, USA) was added to the solution and stirred using a blade propeller for 72 hours. The resin was washed with 1000 mL of distilled water on a membrane filter with a 5 μm pore size, and suspended in 50 mL of 1M glycine solution, pH 8.0, adjusted by NaOH. After incubation overnight, the resin was washed with 2 liters of distilled water on a filter, and dried in a desiccator. Yield of polymixin B-conjugated resin (this is called as RPMB) was 3.9 g.
Example 2
Epoxyacryl resin-Polymixin B Conjugate, RPMB-1
[0044] Polymixin B sulfate (3 million units, Maruko Pharmaceuticals) was dissolved in 200 mL of 0.1M NaCl, and adjusted pH to 8 by adding NaOH. Four grams of polyacryl resin with epoxy residue (Amberzyme, Rohm and Haas, USA) was transferred into a mortar, and grounded with a pestle by adding polymixin B sulfate solution drop-wise. Polymixin B and epoxyacryl resin was stirred for 72 hours using a magnetic stirring bar. The resin was washed with 1 liter of distilled water on a membrane filter with a 5 μm pore size, then suspended in 50 mL of 1M glycine solution, pH 8.0, adjusted with NaOH. After incubation overnight, the resin was washed with 2 liters of distilled water on a filter and dried in a desiccator. The yield of polymixin B-conjugated resin (this is called as RPMB-1) was 3.2 g.
Example 3
Epoxyacryl Resin-Polymixin B Conjugate, RPMB-2
[0045] One gram of polyacryl resin containing epoxy residue (Amberzyme, Rohm and Haas, USA) was grounded with a mortar and pestle. The powdered resin was suspended in 20 mL of distilled water, reacted with 0.6 g of epichlorohydrin and 0.3 mL of 50% NaOH for 2 hours. The resin was washed with 100 mL of distilled water on a membrane filter with a 5 μm pore size, and then mixed with in 5 mL of 1M phosphate buffer, pH 10.0, containing 3 million units of polymixin B, and stirred at 40° C. for 16 hours. After the reaction, the resin suspension was added by 50 mL of 1M glycine solution, pH 8.0, adjusted with NaOH, and kept overnight. The resin was washed with 2 liters of distilled water on a filter and dried in a desiccator. The yield of polymixin B-conjugated resin (this is called RPMB-2) was 0.5 g.
Example 4
Weakly Acidic Cation-Exchange Resin-Polymixin B Conjugate
[0046] Four grams of weakly acidic cation-exchange resin with carboxyl residues (Dowex MAC-3), was suspended in 50 mL of 0.1M MOPS (3-morpholinopropanesulfonic acid) solution, pH 7.5, and then reacted with 1 g of 1-Ethyl-3-(3-dimethylaminopropyl) carbodiimide hydrochloride (Sigma, USA), a coupling agent, at 4° C. for 2 hours with stirring. The activated resin was collected on a membrane filter with a 5 μm pore size and washed with 200 mL of distilled water. The washed activated resin was then suspended in 50 mL of 0.1M MOPS, pH 7.5, and then mixed with 3 million units of polymixin B dissolved in 10 mL of 0.1M MOPS solution, pH 7.5, and reacted at 4° C. for 16 hours with stirring. The resin was collected on a membrane filter with a 5 μm pore size and then suspended in 50 mL of 1M glycine solution, pH 8.0, adjusted with NaOH, and kept at 4° C. overnight, washed with 2 liters of distilled water and then dried in a desiccator. The yield of polymixin-conjugated weakly acidic cation exchange resin (This preparation is called 4/300) was 3.8 g.
Example 5
Weakly Acidic Cation-Exchange Resin-Polymixin B Conjugate, 1/300
[0047] Using the same resin (Dowex MAC-3) and same procedures shown in the example 4, except reducing the amount of resin from 4 to 1 g, 0.9 g of polymixin B-conjugated weakly acidic cation exchange resin was obtained. This preparation is called 1/300.
Example 6
Weakly Acidic Cation-Exchange Resin-Polymixin B Conjugate, 4M/300
[0048] Four grams of weakly acidic cation-exchange resin with carboxyl residues (Dowex MAC-3), was grounded with a mortar and pestle, and suspended in 50 mL of 0.1M MOPS, pH 7.5. The resin was reacted with 1 g of 1-Ethyl-3-(3-dimethyl-aminopropyl) carbodiimide hydrochloride (Sigma, USA), a coupling agent, at 4° C. for 2 hours with stirring. The activated resin was collected on a membrane filter with a 5 μm pore size and washed with 200 mL of distilled water. The resin was suspended in 50 mL of 0.1M MOPS, pH 7.5, and then added to 10 mL 0.1M MOPS, pH 7.5, containing 3 million units of polymixin B. Polymixin B and the resin were reacted at 4° C. for 16 hours with stirring. The resin was collected on a membrane filter with a 5 μm pore size and then suspended in 50 mL of 1M glycine solution, pH 8.0, adjusted with NaOH, and kept overnight, washed with 2 liters of distilled water, and then dried in a desiccator. The yield of polymixin B-conjugated weakly acidic cation exchange resin was 3.1 g. This preparatopm is called 4M/300.
Example 7
Weakly Acidic Cation-Exchange Resin-Polymixin B Conjugate, 1M/300
[0049] Using the same resin and same procedures as described in example 6, except reducing the amount of resin from 4 to 1 g, 0.52 g of polymixin B-conjugated weakly acidic cation exchange resin was obtained. This preparation is called 1M/300.
Example 8
Large Scale Grinding of Resin
[0050] Dowex Mac-3 resin (diameter: 300-1200 mm), 3300 liters, was grounded using a Dalton NeaMill, NEA-48 type. The yield of powdered Mac-3 was 1400 kg and the average particle size was 30 μm, ranging from 10 to 50 μm.
Example 9
Measurement of Particle Size Distribution
[0051] The particle size distribution was measured according to “Measurement of Particle Size Distribution. Method 1: Microscopic method” in the second supplement of the general test procedures, Section 65, Japanese Pharmacopoeia, 13 th Issue. The microscope and camera used for this experiment was Nikon ECLIPSE E600 and Victor KY-F55B, respectively. The collected data was analyzed using Nano Hunter NS2K-Pro. The result of analysis of 1006 particles of RPMB prepared in Example 1 by this method is shown in Table 1. The 50% particles size of RPMB was 213 μm, and the content of small particles not more than 5 μm in a diameter was 0%.
[0000]
TABLE 1
Distribution of particles Size of RPMB*
Distribution of Particle
Size
Diameter
10% Diameter
160 (μm)
50% Diameter
213 (μm)
90% Diameter
266 (μm)
Average Diameter
197 (μm)
*Total 1006 particles were analyzed.
Example 10
Endotoxin Adsorption and Elimination Capacity (1)
[0052] Endotoxin was assayed by an end point calorimetric assay method using Endospecy-ES24S kit (Seikagaku Kogyo, Japan). Lipopolysaccharide (LPS) from E. coli O-111 (Sigma L4130) was dissolved in pyrogen free water at 5 μg/mL. One mL of this LPS solution was mixed with 50 μg and 100 μg of RPMB-1, and 100 μg of polymixin B-unconjugated resin (control) and incubated at 37° C. with stirring. Endotoxin levels were determined in the supernatant before, 10 and 20 minutes after adding the resins. As shown in Table 2, LPS was specifically adsorbed by RPMB-1.
[0000]
TABLE 2
Endotoxin removal activity of RPMB determined by
limulus assay
Amount
LPS Activity (EU/mL) Remaining
Resin
(μg)
Before
10 min
20 min
RPMB-1
50
5632
2403
1207
RPMB-1
100
5526
1004
170
Control
100
5711
4605
4988
Resin
Example 11
Endotoxin Adsorption and Elimination Capacity (2)
[0053] The endotoxin binding capacity of polymixin B conjugates was also studied. LPS (Sigma L4130) was dissolved in pyrogen free water at 0.2 mg/mL, and 4 mL of this solution was added to a test tube containing 20.6 mg of RPMB-1, and incubated at 37° C. with stirring. The supernatant was collected every 30 minutes by centrifugation and the OD values at 210 nm was determined. The OD210 value was dropped from 1 to 0.6 within the first 30 minutes of incubation and remained unchanged afterwards. By adding 20.5 mg of fresh RPM-1 into the supernatant, the OD value was slightly reduced from 0.6 to 0.4. Therefore, it was assumed that 20.6 mg of LPS adsorbent added in the first test tube was saturated with LPS. Accordingly, LPS adsorption capacity of RPMB-1 was calculated based on the OD value changes of LPS solution. Since the LPS preparation used in this experiment is not pure and contaminated by DNA and proteins, it was assumed that the final OD value of 0.4 reflects the OD value of such contaminants. Based on this assumption, it was calculated that 1 g of RPMB is capable of binding approximately 25.9 mg of LPS (Sigma L4130) using the following formula:
[0000] (0.8 mg×0.4/0.6)/0.0206=25.9 mg
Since the endotoxin unit of this LPS preparation is 1.1×10 6 EU/mg, it was calculated that 1 g of RPMB-1 is capable of binding 29×10 6 EU of endotoxin.
Example 12
Effect of Particle Size on Endotoxin Binding Capacity
[0054] Polymixin B-conjugated resins prepared in Examples 1-7 were analyzed for their particle size distribution by the method described in Example 9 and assayed for the endotoxin binding capacity by the method described in Example 11 to study the relationship between particle size and LPS binding capacity. AffiPrep poplymixin B (BioRad, USA) was used as a reference.
[0055] The endotoxin binding capacity of individual batches of endotoxin-adsorbents prepared by conjugating with 3 million units of polymixin B was compared and expressed as endotoxin units (EU) per gram weight of resin as well as LPS weight per gram resin. The weight of LPS was obtained by converting the EU values based on the EU value per mg of LPS preparation (Sigma L4130, LPS preparation from E. coli O-111,B4, by trichloroacetic acid extraction) used for this experiment.
[0056] In spite of using the same amount of 3 million units of polymixin B to make conjugates as described in Example 1-7, it was apparent that endotoxin-binding capacity of polymixin B-conjugated resin is higher if the 50% particle size is smaller as shown in Table 3.
[0000]
TABLE 3
Relationship between particle sizes and endotoxin
binding capacity
50%
Endotoxin
Endotoxin
Particle
Binding
Binding
Polymixin B-
Size
Capacity
Capacity
Conjugated Resins
(μm)
(EU/g)
(LPS mg/g*)
AffiPrep
61
14 × 10 6
12 (mg)
Polymixin B
(Reference)
RPMB
213
20 × 10 6
17.5 (mg)
RPMB-1
32
29 × 10 6
26.5 (mg)
RPMB-2
32
120 × 10 6
105 (mg)
4/300
400
7.2 × 10 6
6.3 (mg)
1/300
400
7.7 × 10 6
6.7 (mg)
4M/300
26
29.5 × 10 6
30 (mg)
1M/300
29
136.3 × 10 6
120 (mg)
*Converted to dry weight of LPS
Example 13
Evaluation of Endotoxin-Adsorbent in Autoantibody Mediated, LPS-Induced Arthritis Model
[0057] DBA/1JNCrj mice (Japan Charles River) were divided into 5 groups (G1-G5, 5 mice per group). In order to increase the mucosal permeability, all mice received 40 μg of indomethasin (Sigma) and 2 mg of ovomucoid (Sigma) for 5 consecutive days from day −6 to −2 by oral route. On day 0, all mice received an IV injection of 0.2 mL of arthritogenic monoclonal antibody cocktail (10 mg/mL). Endotoxin derived from E. coli O-111 (Phenol extracted LPS, Sigma) was dissolved in PBS at 7.5 mg/mL, and 0.2 mL of this solution was administered into G1-G4 mice by oral route for 3 consecutive days from day 0 to 2. Endotoxin-adsorbent, RPMB-1, was suspended in distilled water at 100 mg/mL, and deaerated by vacuum pump to keep the particles in uniform suspension by preventing the aggregation of particles. The RPMB-1 suspension was administered to mice at doses of 0.125 mL (G2), 0.25 mL (G3) and 0.5 mL (G4) twice a day for 4 consecutive days from day 0 to 3 after LPS administration. G1 received 0.25 mL of water alone. Mice in G5, a positive control of arthritis, received IP injection of 0.1 mL of LPS solution (0.5 mg/mL in PBS) on day 3.
[0058] All mice were observed for the development of arthritis every day from day 0 to 14. Severity of arthritis was scored by 5 grades, 0: normal without any swelling, 1: clinically apparent swelling of one digit, 2: moderate redness and swelling of more than 2 digits or moderate redness and swelling of the entire paw, 3: severe redness and swelling of the entire paws, and 4: maximum inflamed limb with involvement of multiple joints. The sum of arthritis score (maximum 16 per mouse) of individual animals was calculated. The effect of endotoxin-adsorbent was calculated based on the average score of 5 mice using the following equation:
[0000] Suppression of arthritis (%)=(1−Average score of test group/Average score of control group)×100
[0000] Since the arthritis scores reached a maximum on day 7, the effect of endotoxin-adsorbent was calculated using the scores on day 7. The suppression of arthritis by RPMB prepared in EXAMPLE 2 at 25 mg, 50 mg and 100 mg per mouse by oral administration is shown in Table 3. None of the five mice which received 100 mg of RPMB-1 developed arthritis, whereas 2 out of 5 mice which received 50 mg of RPMB-1 developed mild arthritis (average score: 2), and 4 out of 5 mice which received 25 mg of RPMB-1 developed moderate arthritis (average score: 9) (Table 3, experiment 1), indicating a dose response effectiveness of RPMB-1.
[0059] Similarly, RPMB-2, 1M/300 and 4M/300, which have higher binding capacities of LPS then RPMB-1, were also tested for their effect on arthritis at a dose of 10 mg per mouse. All three preparations were equally effective and suppressed the development of arthritis almost completely (Table 3, experiment 2).
[0000]
TABLE 3
Suppression of arthritis by polymixin B conjugated
resins
Polymixin B-
Incidence
Severity of
Experiment
Conjugated
Dose
of
Arthritis
No
Resin
(mg/mouse)
Arthritis
(Score)
1
Control Resin
50
5/5
12 ± 1.6
RPMB-1
25
4/5
6.4 ± 1.8
RPMB-1
50
2/5
2 ± 2.8
RPMB-1
100
0/5
0 ± 0
2
Control Resin
10
5/5
12.6 ± 1.1
RPMB-2
10
0/5
0 ± 0
4M/300
10
1/5
0.8 ± 1.8
1M/300
10
0/5
0 ± 0
Example 14
Tablet
[0060] The tablets were prepared by mixing 15 g of 1M/300, which was prepared in EXAMPLE 7, 2.5 g of lactose, 2.4 g of corn starch, and 0.1 g of magnesium stearate. These four components were mixed well and compressed by single punch tableting machine to make tablets containing 200 mg of 1M/300 per a tablet.
Example 15
Capsule
[0061] RPMB-2 powder shown in EXAMPLE 3 was dispensed into hard capsules at 150 mg per a capsule. | It is believed that the abnormal absorption of endotoxin present in the gastrointestinal tract relates to the pathogenesis of autoimmune diseases such as rheumatoid arthritis. In an animal model for rheumatoid arthritis, it is observed that arthritis is improved by removing endotoxin. The present invention provides endotoxin-adsorbent, which is capable of removing endotoin in gastrointestinal tract and can be administered to humans safely. By using a non-digestible and non-absorbable, and therefore, safe endotoxin-adsorbent, which has a high endotoxin-binding capacity for removing large amounts of endotoxin present in the gastrointestinal tract, it is possible to prevent and treat autoimmune diseases such as rheumatoid arthritis. | 0 |
FIELD OF THE INVENTION
[0001] The invention relates generally to high-frequency Stirling and acoustic Stirling coolers, and more particularly, to a solution for an acoustic cooling device with a coldhead and an acoustic power source separated.
BACKGROUND OF THE INVENTION
[0002] In recent years, high-frequency (≧30 Hz) Stirling and acoustic Stirling (or high-frequency “pulse-tube”) coolers have attracted much commercial interest because of their higher efficiency, lower maintenance, and lower noise and vibration as compared to rival technologies. One of the chief disadvantages of high-frequency Stirling coolers, however, is that the set of thermally active components (heat rejector, regenerator, and heat acceptor or “cold tip”), often referred to as the “coldhead,” is typically very intimate with the source of acoustic power that drives it. This source is usually a pressure wave generator (PWG), including one or more linear motors coupled to pistons that alternately compress and expand the working gas at the warm end of the coldhead.
[0003] On the other hand, spatial separation of coldhead and acoustic power drive permits the use of acoustic Stirling cooling in applications where space near the region to be cooled is a premium, and/or where vibration at the cold tip must be minimized. Efforts have been made to separate a coldhead and an acoustic drive. However, current technology allows only minimal separation of the drive and the coldhead, for example, the LPT9310 Stirling cooler by Thales Cryogenics BV. None of the current technologies has allowed a separation distance substantially greater than the characteristic dimension of a power wave generator, or of a substantial fraction of an acoustic wavelength (measured at operating frequency). All previous approaches use very narrow-diameter transfer lines, presumably to minimize the volume added by the transfer line, as required especially by Stirling coolers with displacer mechanisms in the coldhead, driven by the pressure wave in the working gas and demanding minimal ‘dead’ or unswept volume to preserve that driving effect. This structure tends to make the gas velocity in the tube very high, necessitating a short length to minimize the visco-acoustic losses on the tube walls. Only one patent, U.S. Pat. No. 5,794,450 (Arthur Ray Alexander), mentions the use of transfer lines to separate the PWG and the coldhead of an acoustic Stirling system for a remotely driven “pulse tube” cooler or an array of coolers. However, in Alexander, the transfer lines are much less than a wavelength in length and on the order of the pressure-wave generator dimensions. In addition, Alexander teaches a loop system, where the phase-shifting network (the acoustic equivalent of a displacer mechanism in a conventional Stirling), connected to the cold-side of the regenerator, is also connected to the PWG as a source of fluid, suggesting that a circulating, not just oscillating, flow is anticipated. Alexander is also specifically limited to the field of cooling electronic components.
[0004] One patent application publication US 20050210887, to Arman, describes a split system with the acoustic driver and coldhead separated by a transfer line for purposes of vibration isolation.
[0005] The pressure-wave generators used in acoustic Stirling coolers are often referred to as “compressors” but are not to be confused with the more familiar kind that take a steady stream of gas at a low, constant pressure and compress it to a higher constant pressure. That type of compressor is found in rival cooling technologies such as Gifford-McMahon coolers or vapor-compression refrigerators. The advantage of that type of compressor and the coolers that use them, is that the compressor and the coldhead or cold heat exchanger can be very remote from each other, with the length of separation having relatively little impact on system performance. The working fluid simply flows unidirectionally through a connecting tube or duct at low, constant velocity, incurring very little pressure drop in the process. A Stirling or acoustic-Stirling system, by contrast, is very sensitive to the size of a volume or length of a duct connecting main components because the entire system must be dynamically resonant, and every component experiences significant oscillating pressure and/or oscillating flow.
[0006] A long coupling tube which is a significant fraction of a wavelength will shift the system's resonant frequency, change the impedance seen by the pistons in the pressure-wave generator, and experience non-negligible acoustic power loss on the tube surface. At 60 Hz, the wavelength of sound in helium gas at 300K is about 17 meters; the oscillating pressure and particle velocity go through their maximum variation in a quarter wavelength, so in order to avoid wavelength effects, the length of a transfer line must be kept much shorter than a quarter wavelength. To avoid significant impacts on the stroke of the PWG motors or the PWG's natural frequency, the transfer line's total volume must also be minimized. For these reasons, Stirling and acoustic-Stirling coldheads in split systems always have had transfer lines that are extremely narrow in diameter and relatively short, ≦50 cm long for systems that run at or near 60 Hz.
[0007] To this extent, a need exists for a solution for an acoustic cooling device with a coldhead and an acoustic power source separated by a distance that is not necessarily short compared to a wavelength. This extends the usefulness of a high-frequency acoustic Stirling cooler to applications where a relatively large separation distance is required or desired.
SUMMARY OF THE INVENTION
[0008] An acoustic cooling device is provided. A coldhead and an acoustic power source of the acoustic cooling device are separated by way of a long tube connecting them to enable the cold tip to be installed in a remote location where a traditional unitary system would not fit, would generate too much vibration, or would be otherwise undesirable. The dimensions of the tube and the relevant parameters of the acoustic power source are selected to keep the system resonant at the desired drive frequency (e.g., 60 Hz) and to minimize the impact of the long tube on the system efficiency and capacity.
[0009] A first aspect of the invention provides an acoustic cooling device, the cooling device comprising: an acoustic power source; and a first acoustic cooling head, wherein the acoustic power source and the first acoustic cooling head are connected by a first transfer line, a length of the first transfer line being at least 0.15 of a quarter wavelength in a working fluid at an operating frequency.
[0010] A second aspect of the invention provides a chilled storage system, the chilled storage system comprising: a chamber; and a cooler comprising an acoustic power source and a first acoustic cooling head connected by a first transfer line, wherein the first acoustic cooling head is in thermal communication with an interior of the chamber, and the acoustic power source is remotely located outside the chamber.
[0011] The illustrative aspects of the present invention are designed to solve the problems herein described and other problems not discussed, which are discoverable by one skilled in the art.
BRIEF DESCRIPTION OF THE DRAWINGS
[0012] These and other features of the invention will be more readily understood from the following detailed description of the various aspects of the invention taken in conjunction with the accompanying drawings that depict various embodiments of the invention, in which:
[0013] FIG. 1 shows a pressure wave generator with a remote coldhead according to one embodiment of the invention.
[0014] FIG. 2 shows performance of a split acoustic-Stirling cooler according to one embodiment of the invention compared to an equivalent unitary system.
[0015] It is noted that the drawings are not to scale. The drawings are intended to depict only typical aspects of the invention, and therefore should not be considered as limiting the scope of the invention. In the drawings, like numbering represents like elements between the drawings.
DETAILED DESCRIPTION
[0016] The present invention includes an acoustic cooling device with a working fluid at an operating frequency of approximately 60 Hz. The acoustic cooling device uses a transfer line which may be several meters long, and may contain total gas volume several times larger than the gas volume in a coldhead of the acoustic cooling system. Furthermore, the acoustic cooling device may be optimized to have efficiency close to or equal to that of an equivalent unitary system. This design is not possible in the existing systems because the addition of so much volume would cause the pressure wave generator to overstroke before useful pressure-wave amplitudes were reached, unless the transfer line were made extremely narrow, in which case the resulting high acoustic velocity in the transfer line would cause prohibitively high acoustic losses (hence the narrow, short transfer lines in all existing commercial systems).
[0017] What enables the present invention is a creative new understanding of the relevant relationships among components in an acoustic cooling system. It is known that the adiabatic volume in a PWG is not necessarily optimum when it is minimized. Rather, the piston diameter can be chosen to accommodate a given adiabatic volume, and the two can be chosen to guarantee that the motors in a PWG will execute their ideal stroke (e.g., for maximum efficiency) when producing the necessary pressure wave for a given load. (See Corey et al., U.S. Pat. No. 6,604,363.) If that load includes a long transfer tube of non-negligible volume, it may require that the pistons be enlarged to accommodate it. Conventional thinking would conclude that this would result in lower efficiency due to the increased piston seal perimeter and associated losses. The present invention recognizes that this may not be the case, due to complementary effects. For instance, an acoustic coldhead preferably has a pressure antinode, or a region of maximum acoustic pressure, at or near the center of the regenerator. The farther one obtains from the regenerator, up to a quarter wavelength, the lower the acoustic pressure amplitude. Because the dissipation (losses) in a clearance seal is proportional to the acoustic pressure squared, the seal loss (at the pistons, remote from the regenerator) may be, overall, lower with a long transfer line, even if the pistons are larger, but at a position of lower acoustic pressure than the regenerator. This may offset some of the losses that occur in the transfer line itself.
[0018] With reference to the figures, one embodiment of the invention will be described here. It should be understood that the invention is not limited to the embodiment described. FIG. 1 shows an acoustic cooling device 10 including an electrically-driven pressure-wave generator (PWG) 1 with a remote coldhead 2 according to one embodiment of the present invention. As shown in FIG. 1 , PWG 1 is connected to coldhead 2 by means of a long flexible transfer line 3 . Coldhead 2 is substantially insensitive to orientation. A portion of an inertance tube 4 is located along transfer line 3 . Coldhead 2 is in turn connected by means of inertance tube 4 to a reservoir, e.g., compliance tank 5 . Transfer line 3 has a length ( 7 ) that is, according to one embodiment, approximately 125 cm, over four times the longest PWG dimension ( 6 ) of approximately 31 cm. The frequency of a working fluid (not shown) is approximately 60 Hz and the fluid is helium, so the transfer line 7 is about 0.3 of a quarter wavelength (here 4.25 meters). A transfer line that is more than 0.15 of a quarter wavelength is considered a significant fraction of the quarter wavelength. An inner diameter 8 of transfer line 3 is selected based on a piston size (not shown) and an adiabatic volume (not shown) of PWG 1 to maximize overall efficiency. In the embodiment shown in FIG. 1 , transfer line ( 3 ) inner diameter ( 8 ) is approximately 0.80 cm, and its total volume (not shown) is approximately 61 cubic centimeters (cc). Cooling device 10 may further include a cooling fluid (not shown) for rejecting heat from coldhead 2 . In one embodiment, a portion of the cooling fluid is conducted along transfer line 3 . For maximum convenience, transfer line 3 may be enclosed with any of inertance tube 4 and conduits for cooling fluid (not shown) in a common protective shroud extending between PWG 1 and coldhead 2 , including flexible lines ( 3 ) comprising inner corrugations and outer braided coverings, as are known in the art. Inertance tube 4 and the conduits for cooling fluid (not shown) may be co-routed with transfer line 3 .
[0019] In this embodiment, a volume of all the gas in coldhead 2 (excluding inertance tube 4 and compliance tank 5 ) is less than approximately 37 cc, so transfer line 3 in this embodiment has considerably more gas volume than coldhead 2 .
[0020] FIG. 2 shows the performance of an acoustic cooling device 10 ( FIG. 1 ) according to one embodiment of the present invention (shown by line 100 ), versus that of an equivalent unitary system (shown by line 200 ). The unitary system uses the same PWG and coldhead as the acoustic cooling device 10 ( FIG. 1 ) of the current invention, but does not include a transfer line. As shown in FIG. 2 , the performances of the two systems are nearly identical, which shows that, against conventional expectation, a long transfer line does not have to be a significant penalty on cooler performance when designed correctly.
[0021] It should be understood that the scope of the current invention is not limited to the above-described embodiment, and the current invention provides various alternative embodiments. For example, according to one alternative embodiment, an acoustic cooling device may further include more than one coldheads and more than one transfer line. Each coldhead is connected to a (shared) PWG by a transfer line, and each transfer line is (connected in) parallel to one another. According to one embodiment, the more than one coldheads and the more than one transfer lines are unequal in length and volume. In another embodiment, inertance tube 4 and an associated reservoir (not shown) are part of the coldhead ( 2 ) assembly, so that inertance tube 4 does not extend from the coldhead 2 to the PWG 1 as it does in FIG. 1 .
[0022] In still another embodiment, an acoustic cooling device includes at least two coldheads. One of the coldheads is connected to a PWG by a transfer line and the other cooling head is mounted directly to the PWG.
[0023] In still another embodiment, a chilled storage system includes a chamber and an acoustic cooling device as described above. An acoustic cooling head is in thermal communication with an interior of the chamber, and the acoustic power source is remotely located outside the chamber.
[0024] It should be understood that generally, for any given transfer line or plethora of lines connecting to coldheads, the piston size and adiabatic volume of PWG 1 ( FIG. 1 ) can be chosen to guarantee system resonance at the desired frequency and adequate stroke to reach the desired pressure wave amplitude at coldhead 2 ( FIG. 1 ). The present invention recognizes that if a certain transfer line length is desired, transfer line diameter together with PWG adiabatic volume and piston size can be chosen to not only guarantee proper resonance frequency and sufficient piston stroke, but also to minimize the impact of the transfer line on the system performance.
[0025] The foregoing description of various aspects 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 form disclosed, and obviously, many modifications and variations are possible. Such modifications and variations that may be apparent to an individual in the art are included within the scope of the invention as defined by the accompanying claims. | An acoustic cooling device is provided. A coldhead and an acoustic power source of the acoustic cooling device are separated by way of a long tube connecting them to enable the cold tip to be installed in a remote location where a traditional unitary system would not fit, would generate too much vibration, or would be otherwise undesirable. The dimensions of the tube and the relevant parameters of the acoustic power source are selected to keep the system resonant at the desired drive frequency (e.g., 60 Hz) and to minimize the impact of the long tube on the system efficiency and capacity. | 5 |
CROSS-REFERENCE TO RELATED APPLICATIONS
This application is a continuation of U.S. patent application Ser. No. 12/895,258, filed on Sep. 30, 2010, the disclosure of which is expressly incorporated herein by reference in its entirety.
BACKGROUND
This specification generally relates to transmitting audio data.
An increasing number of users are utilizing voice recognition applications on computing devices. The use of a voice recognition application allows a user to dictate speech input for subsequent processing into text for input to an application program. This enables a user to provide input data or commands to an application in a “hands free” mode of operation. For example, a user can run a voice search application on a mobile phone. The mobile phone can include a microphone for audio input and a display device (e.g., a touchscreen) for displaying output to the user. The user can speak the topic they would like to search into the microphone (e.g., “Presidents of the United States”). The mobile phone can record the audio input stream (the user's spoken words). The mobile phone can digitize the recorded audio input stream. The mobile phone can transmit the audio input stream using a mobile communication network (e.g., a third generation (3G) network) to a receiver included in a speech recognition server. The speech recognition server can further process the received audio input stream in order to recognize the spoken words. A search engine application can receive the recognized spoken words as text input from the speech recognition server. The mobile phone can receive the results of the voice search from the search engine for display to the user on the display device (e.g., information regarding the Presidents of the United States, a list of the Presidents of the United States, etc.).
SUMMARY
According to one innovative aspect of the subject matter described in this specification, a user can utilize a voice search application on a mobile device (e.g., a mobile phone) to request information verbally regarding a topic of interest. For example, the user is a passenger in a car, driving with their spouse, and they are talking about where to spend time on their next vacation. The user would like information regarding the best beaches in the United States. The user, interacting with the voice search application on their mobile phone, speaks the words “best beaches in the United States” into the microphone on their mobile phone. The user expects the results of the voice search almost immediately. The mobile phone can transmit the input speech using a mobile communications network (the same network used to place and receive phone calls) to a server provided by the mobile communication service provider. The server can recognize the input speech, run a search engine using the recognized speech input and provide the search results to the user on their mobile phone. The mobile phone can display the search results on the display screen of the mobile phone as a list of web site links the user can visit to provide the requested information. However, as the user is traveling in the car the quality and speed of the mobile communications network can vary affecting the time between the spoken words and the search results. The mobile phone can provide the input speech to the server as a series of blocks where each block provides additional incremental data regarding the input speech. A speech recognition application on the server can attempt to recognize the input speech after receiving each block of data. Once the speech recognition application is confident it has successfully recognized the input speech it no longer needs to receive and process subsequent data blocks of input speech from the mobile phone. Therefore, the user can receive the results of the voice search more quickly than if the mobile phone sent the entire input speech to the server.
In general, innovative aspects of the subject matter described in this specification may be embodied in methods that include the actions of retrieving a digital audio signal, processing the digital audio signal to generate a first sub-set of data, the first sub-set of data defining a first portion of the digital audio signal, transmitting the first sub-set of data for generation of a reconstructed audio signal, the reconstructed audio signal having a fidelity relative to the digital signal, processing the digital audio signal to generate a second sub-set of data and a third sub-set of data, the second sub-set of data defining a second portion of the digital audio signal and comprising data that is different than data of the first sub-set of data, and the third sub-set of data defining a third portion of the digital audio signal and comprising data that is different than data of the first and second sub-sets of data, comparing a priority of the second sub-set of data to a priority of the third sub-set of data, and transmitting, based on the comparing, one of the second sub-set of data and the third sub-set of data over the network for improving the fidelity of the reconstructed signal. Other implementations of this aspect include corresponding systems, apparatus, and computer programs, configured to perform the actions of the methods, encoded on computer storage devices.
These and other implementations may each optionally include one or more of the following features. For instance, in some implementations, the second sub-set of data includes more data than the first sub-set of data; the actions further include subsequently transmitting the other of the second sub-set of data and the third sub-set of data over the network for further improving the fidelity of the reconstructed audio signal; wherein the third sub-set of data includes more data than each of the second sub-set of data and the first sub-set of data; wherein processing the digital audio signal to generate a first sub-set of data includes: determining an original sampling rate of the digital audio signal, and down-sampling data of the digital audio signal at a first sampling rate that is less than the original sampling rate to provide the first sub-set of data, wherein processing the digital audio signal to generate a second sub-set of data includes: up-sampling data of the first sub-set of data at the original sampling rate to provide first up-sampled data, subtracting the first up-sampled data from data of the digital audio signal to provide first residual data, and down-sampling the first residual data at a second sampling rate that is greater than the first sampling rate and that is less than the original sampling rate to provide the second sub-set of data, wherein processing the digital audio signal to generate a third sub-set of data includes: up-sampling data of the second sub-set of data at the original sampling rate to provide second up-sampled data, and subtracting the second up-sampled data from the first residual data to provide second residual data, the second residual data defining the third sub-set of data; wherein processing the digital audio signal to generate a first sub-set of data includes: determining a bit-depth of data of the digital audio signal, and extracting a first bit of each sample of the data of the digital audio signal to provide first extracted data, the first extracted data defining the first sub-set of data and the first bit being determined based on the bit-depth, wherein processing the digital audio signal to generate a second sub-set of data comprises extracting a second bit of each sample of the data of the data set to provide second extracted data, the second extracted data defining the second sub-set of data and the second bit being determined based on the bit-depth; the actions further include: receiving a signal, and ceasing processing of the digital audio signal to generate sub-sets of data in response to receiving the signal, wherein the signal indicates that a fidelity of reconstructed signal is greater than a threshold fidelity; and the actions further include compressing the first sub-set of data and the one of the second sub-set of data and the third sub-set of data.
In general, other innovative aspects of the subject matter described in this specification may be embodied in methods that include the actions of receiving a first sub-set of data, the first sub-set of data having been generated based on a digital audio signal, processing the first sub-set of data to generate a reconstructed audio signal, the reconstructed signal having a fidelity relative to the digital audio signal, receiving one of a second sub-set of data and a third sub-set of data based on a comparison of a priority of the second sub-set of data to a priority of the third sub-set of data, the second sub-set of data defining a second portion of the digital audio signal and comprising data that is different than data of the first sub-set of data, and the third sub-set of data defining a third portion of the digital audio signal and comprising data that is different than data of the first and second sub-sets of data, and processing the one of the second sub-set of data and third sub-set of data to improve the fidelity of the reconstructed audio signal. Other implementations of this aspect include corresponding systems, apparatus, and computer programs, configured to perform the actions of the methods, encoded on computer storage devices.
These and other implementations may each optionally include one or more of the following features. For instance, in some implementations, the second sub-set of data includes more data than the first sub-set of data; the actions further include: receiving the other of the second sub-set of data and the third sub-set of data, and processing the other of the second sub-set of data and the third sub-set of data to further improve the fidelity of the reconstructed audio signal; the third sub-set of data includes more data than each of the second sub-set of data and the first sub-set of data; processing the first sub-set of data includes up-sampling data of the first data sub-set at an original sampling rate of the data set to provide first up-sampled data, the reconstructed signal being generated based on the first up-sampled data, and the first data sub-set having been generated using a first sampling rate that is less than the original sampling rate, wherein processing one of the second sub-set of data and the third sub-set of data comprises up-sampling data of the one of the second sub-set of data and the third sub-set of data at the original sampling rate to provide second up-sampled data, the second up-sampled data being added to the reconstructed audio signal to improve the fidelity of the reconstructed audio signal, and the one of the second sub-set of data and the third sub-set of data having been generated using a second sampling rate that is less than the original sampling rate and that is greater than the first sampling rate, the actions further include: up-sampling data of the other of the second sub-set of data and the third sub-set of data at the original sampling rate to provide third up-sampled data, and adding the third up-sampled data to the reconstructed audio signal to further improve the fidelity of the reconstructed audio signal; the first sub-set of data is generated by extracting a first bit of each sample of data of the digital audio signal to provide first extracted data, the first extracted data defining the first sub-set of data and the first bit being determined based on a bit-depth, the second sub-set of data is generated by extracting a second bit of each sample of data of the digital audio signal to provide second extracted data, the second extracted data defining the second sub-set of data and the second bit being determined based on the bit-depth; the actions further include: determining that the fidelity of the reconstructed audio signal has achieved a threshold fidelity, generating a signal, and transmitting the signal over a network for ceasing transmission of subsequent sub-sets of data; and the actions further include decompressing the first sub-set of data and the one of the second sub-set of data and third sub-set of data.
The details of one or more implementations of the subject matter described in this specification are set forth in the accompanying drawings and the description below. Other potential features, aspects, and advantages of the subject matter will become apparent from the description, the drawings, and the claims.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1A is a diagram demonstrating encoding an audio input stream as a sequence of data blocks.
FIG. 1B is a diagram of an exemplary system that includes a computing device for transmitting data blocks to a computing device for receiving data blocks using a network.
FIG. 2 is a flowchart of an exemplary process for transmitting data blocks.
FIG. 3 is a flowchart of an exemplary process for receiving data blocks.
FIG. 4 is a flowchart of an exemplary audio encoding process using a sample rate with linear interpolation.
FIG. 5 is a block diagram showing exemplary sample rate encoding.
FIG. 6 is a flowchart of an exemplary audio decoding process using a sample rate with linear interpolation.
FIG. 7 is a flowchart of an exemplary audio encoding process using bit depth.
FIG. 8 is a flowchart of an exemplary audio decoding process using bit depth.
FIG. 9 is a flowchart of an exemplary audio encoding process using linear predictive coding.
FIG. 10 is a flowchart of an exemplary audio decoding process using linear predictive coding.
Like reference numbers represent corresponding parts throughout.
DETAILED DESCRIPTION
A distributed interactive speech application can record an audio or audiovisual signal in a first location and transmit it for further processing to a second location. In some implementations, the second location is remote from the first location. Each location can be a computing device that includes a transmitter and a receiver (or a transceiver). The first location can record, digitize and then transmit the digitized audio signal by way of a network to the second location. The second location can further process the received audio signal for use in one or more applications available at the second location. In some implementations, the first location can be a mobile computing device that records an audio input stream from a user (spoken words). The second location can be an application server. The application server can include a speech recognition application. The mobile computing device can digitize and transmit the recorded audio input stream by way of a mobile communication network to the application server. The speech recognition application can further process the received audio input stream in order to recognize the recorded spoken words. One or more applications on the application server can receive the recognized spoken words as text input from the speech recognition application. In some cases, the application can interpret the input text as one or more commands for processing by the application.
The first location can encode the audio input stream before transmitting the audio input stream to the second location using an audio encoding method. The audio encoding method can preserve the quality and bitrate of the audio input stream. In some situations, the network connection between the first location and the second location can have limited bandwidth. In some situations, the reliability of the network connection may be compromised. For example, a user is using a voice search application on a mobile phone while riding in a car. The overall quality of the mobile communication network may fluctuate as the user travels. The user may expect an action to be performed within a particular time after inputting the audio input stream (e.g., the user receives the results of the voice search). The user may experience a large time delay between the entry of the audio input stream (e.g., speaking the search terms into the microphone of the mobile computing device) and the receipt of the desired response (e.g., the results of the voice search displayed on the display device of the mobile computing device). The large time delay can be due to the poor bandwidth of the network connection between the mobile phone and a remote server. The encoding of the audio input stream at a high quality level and bitrate can also add to the time delay as the high quality level and bitrate can result in a large amount of data transmitted across the network from the mobile phone to the remote server.
In some implementations, the first location can provide an audio encoding method for encoding the audio input stream. Encoding can reduce the latency between the input of the audio stream to the first location (e.g., speaking into the microphone of the mobile computing device) and the receipt of the information regarding the audio input stream at the first location from the second location (e.g., the results of the voice search displayed on the display device of the mobile computing device). In addition, the audio encoding method can preserve the fidelity of the audio input stream, while transmitting the encoded audio data across a variety of networks with varying bandwidths and quality levels. The audio encoding method can encode the audio input stream as a sequence of data blocks where each subsequent data block includes information about the audio input stream not present in the previous data block. In addition, the size of each data block (the amount of data included in each data block) can increase with each subsequent data block. The second location can reconstruct the entire audio input stream at a low quality level from the first block of encoded audio data. The second location can add each subsequent block of encoded audio data to the one or more previous blocks of encoded audio data in order to refine the reconstruction of the audio input stream to have progressively higher fidelity.
In some implementations, each data block in the sequence of data blocks can include a priority. The priority can indicate the order of transmission of the data blocks from the first location to the second location (e.g., highest priority blocks are transmitted first followed by the lower priority blocks). In some cases, a data block can include metadata. The metadata can assist the speech recognition application in the second location with recognizing the encoded audio input stream. For example, metadata can include but is not limited to microphone characteristics, derived noise profiles, and audio data samples taken before the user began speaking (prologue audio). The first location can transmit the data blocks to the second location until the speech recognition application receives sufficient information to reconstruct the audio input stream at a high enough confidence level in order to provide accurate speech recognition. In some situations, the first location can transmit data blocks to the second location until there are no longer additional data blocks for transmission. In some situations, the first location can transmit data blocks to the second location until a timer expires, where the time set for the timer is a maximum user-perceived acceptable latency time from user speech input until receipt of the results.
FIG. 1A is a diagram 100 demonstrating encoding an audio input stream 102 as a sequence of data blocks 104 . An audio encoding method can encode the audio input stream 102 as a sequence of data blocks 104 where each subsequent data block includes information about the audio input stream 102 not present in the previous data block. The audio encoding method can encode the audio input stream 102 as a sequence of data blocks 104 where n number of data blocks can represent the complete audio input stream 102 .
FIG. 1B is a diagram of an exemplary system 150 that includes a first computing device 152 for transmitting data blocks to a second computing device 156 for receiving the data blocks using a network 154 . Referring to FIGS. 1A and 1B , the first computing device 152 encodes the audio input stream 102 as a sequence of data blocks 104 . The first computing device 152 sequentially transmits the data blocks 104 to the second computing device 156 by way of the network 154 . A speech recognition application on the second computing device 156 reconstructs a portion of the audio input stream from a first data block 104 a where the quality level of the reconstructed portion of the audio input stream is below that of the original audio input stream 102 . Subsequent data blocks in the sequence of data blocks 104 can refine the reconstructed audio input stream to have progressively higher fidelity. For example, data block 104 b includes data for the audio input stream 102 not included in data block 104 a . In addition, the sizes of each data block (the amount of data included in each data block) can increase with each subsequent data block. For example, data block 104 b can include more data for the audio input stream 102 than the amount of data included in data block 104 a.
The speech recognition application can reconstruct the entire audio input stream at a low quality level from a first block of encoded audio data (e.g., data block 104 a ). The speech recognition application can add each subsequent block of encoded audio data to the one or more previous blocks of encoded audio data in order to refine the reconstruction of the audio input stream to have progressively higher fidelity. For example, the speech recognition application can add data block 104 b to data block 104 a . The addition of data block 104 b to data block 104 a further refines data block 104 a . The speech recognition application can add data block 104 c to the sum of data block 104 a and data block 104 b to further refine the reconstruction of the audio input stream. In some implementations, the second computing device 156 can request the transmitting of each additional data block from the first computing device 152 until the speech recognition application is confident is has received sufficient information regarding the audio input stream 102 in the data blocks to accurately recognize the input speech. In some implementations, the first computing device 152 can transmit the entire sequence of data blocks (e.g., data blocks 104 ) to the second computing device 156 . In some implementations, the first computing device 152 can transmit data blocks to the second computing device 156 until a preset amount of time expires. The amount of time can be determined based on a maximum user-perceived acceptable latency time from the input of the user speech on the first computing device 152 until the receipt of the results of the speech recognition application from the second computing device 156 by the first computing device 152 .
In some implementations, the information in one or more data blocks in a sequence of data blocks can be metadata. For example, the metadata can include but is not limited to microphone characteristics of an input device, derived noise profiles, and prologue audio, which is audio data samples taken before the user began speaking. The speech recognition application in the second computing device 156 can use the metadata to assist in recognizing the encoded audio data provided in the additional data blocks transmitted from the first computing device 152 .
In some implementations, each data block in the sequence of data blocks 104 can include a priority. The priority can indicate the order of transmission of the data block from the first computing device 152 to the second computing device 156 . The first computing device can transmit the data blocks with higher priority before data blocks with lower priority. In some implementations, the first computing device 152 may encode the audio input stream 102 as a sequence of data blocks 104 where the audio encoding method assigns each data block a priority as it generates the data blocks. For example, the first computing device 152 encodes the audio input stream 102 in four data blocks (e.g., data blocks 104 a - d , where the number of data blocks, n, is equal to four). The audio encoding method assigns progressively lower priorities to each data block 104 a - d as it generates each data block. The first data block 104 a of the encoded audio data can provide a low quality outline of the audio input stream. The audio encoding method assigns the first data block 104 a the highest priority. Each subsequent data block 104 b , 104 c , 104 d provides additional information not present in the preceding data block and is assigned a progressively lower priority (e.g., data block 104 b has a higher priority than data block 104 c which has a higher priority than data block 104 d ). The speech recognition application on the second computing device 156 can reconstruct the audio input stream in the order in which the second computing device 156 receives the data blocks from the first computing device 152 . The speech recognition application reconstructs the audio input stream at a first quality level using data block 104 a . Subsequent data blocks 104 b , 104 c , 104 d provide progressively higher fidelity to the reconstructed audio input stream of data block 104 a.
In some implementations, the first computing device 152 may encode the audio input stream 102 as a sequence of data blocks 104 where the audio encoding method can generate all the data blocks prior to assigning their priority. For example, the first computing device 152 encodes the audio input stream 102 in three data blocks (e.g., data blocks 104 a , 104 c , and 104 d ) where a fourth data block, data block 104 b , consists of metadata (e.g., audio prologue information). The audio encoding method can assign the data blocks 104 a - d progressively lower priorities. In the case of metadata blocks, it may be necessary to transmit at least one block of encoded audio input data prior to transmitting the metadata block, as the second computing device 156 may not use the information in the metadata block alone to recognize the audio input stream.
FIG. 2 is a flowchart of an exemplary process 200 for transmitting data blocks. For example, referring to FIGS. 1A and 1B , the first computing device 152 can perform the process 200 in order to encode the input audio stream 102 , generate data blocks 104 , and transmit data blocks 104 . The process 200 begins by identifying data for encoding (step 202 ). For example, the process 200 can identify input audio stream 102 as the input audio data for encoding. The process 200 generates an initial data block based on the data (step 204 ). For example, the process 200 can generate data block 104 a based on the encoded input audio stream. The initial data block is transmitted (step 206 ). For example, the first computing device 152 can transmit data block 104 a using network 154 to the second computing device 156 . In step 208 , if additional data blocks can be generated for the data, the process 200 generates a subsequent data block based on the data and any previous data blocks (step 210 ). For example, the first computing device 152 can generate an additional data block for the encoded input audio stream (e.g., data block 104 b ). The data in the subsequent data block 104 b can be data not previously included in the previous data block 104 a . In addition, the size of the data block 104 b may be larger than the size of the previous data block 104 a . The data block 104 b can provide additional information to combine with data block 104 a to provide a higher quality representation of the input audio stream. The subsequent data block is transmitted (step 212 ). For example, the first computing device 152 can transmit data block 104 b to the second computing device 156 . The second computing device 156 can use the data in both the data block 104 a and the data block 104 b in order to recognize the speech of the input audio stream. The process 200 continues to step 208 . If in step 208 , additional data blocks are available, the process 200 continues to step 210 . If in step 208 , no additional data blocks can be generated for the data, the process 200 ends.
In some implementations, the first computing device 152 can base the determination for generation of additional data blocks (step 208 ) on the receipt of a request for an additional data block from the second computing device 156 . For example, if a voice recognition application on the second computing device 156 can recognize the input audio stream prior to the first computing device transmitting all available data blocks, the second computing device 156 can instruct the first computing device 152 not to transmit subsequent data blocks. In some implementations, the first computing device 152 can base the determination for generation of additional data blocks (step 208 ) on a timer. If the set time for the timer has expired, the process 200 may no longer generate and transmit additional data blocks.
FIG. 3 is a flowchart of an exemplary process 300 for receiving data blocks. For example, referring to FIGS. 1A and 1B , the second computing device 156 can perform the process 300 in order to receive, decode and reconstruct the input audio stream 102 for use in a voice recognition application. The process 300 begins by receiving a data block (step 302 ). For example, the first computing device 152 using network 154 transmits data block 104 a to the second computing device 156 , which receives the data block 104 a . The process 300 decodes the data block to reconstruct the signal (step 304 ). For example, the second computing device 156 decodes data block 104 a to reconstruct a low quality version of the input audio stream 102 . In step 306 , if additional data blocks are available, the process 300 receives a subsequent data block (step 308 ). For example, the second computing device 156 receives data block 104 b . The process 300 decodes the subsequent data block (step 310 ). For example, the second computing device 156 decodes the data block 104 b . The process 300 adds the data from the subsequent data block to the reconstructed signal (step 312 ). This results in an update of the reconstructed signal where the subsequent data block provides additional data regarding the original input audio stream. For example, the decoded data from data block 104 b is added to the decoded data from data block 104 a resulting in an updated reconstructed signal that includes the additional data provided by data block 104 b to provide a higher quality version of the input audio stream 102 .
In some implementations, step 304 of the process 300 can provide a low quality version of the input audio stream as an initial reconstructed signal to a voice recognition application. If the voice recognition application can recognize the speech from the reconstructed signal, the second computing device 156 can inform the first computing device 152 that successful recognition has occurred. The first computing device 152 may no longer provide subsequent data blocks to the second computing device 156 . In some implementations, step 312 of the process 300 can provide a version of the reconstructed signal to a voice recognition application. If the voice recognition application can recognize the speech from the version of the reconstructed signal provided by step 312 , the second computing device 156 can inform the first computing device 152 that successful recognition has occurred. The first computing device 152 may no longer provide additional subsequent data blocks to the second computing device 156 . If the voice recognition application cannot recognize the speech from the version of the reconstructed signal provided by step 312 , the process 300 can continue by receiving a subsequent data block. Step 312 of the process 300 can add data from each subsequent data block received to the version of the reconstructed signal creating a progressively higher quality version of the reconstructed signal for input to the voice recognition application. The voice recognition application can receive each version of the reconstructed signal and if successful recognition occurs, subsequent data may no longer be needed from the first computing device 152 .
In some implementations, the second computing device 156 can decide to no longer request or receive additional data blocks from the first computing device 152 . This second computing device 156 can base this decision on a timer. For example, a set time for a timer can be based on the acceptable latency time between receipt of the first data block by the second computing device 156 and transmission of the results requested by the speech of the input audio stream 102 by the second computing device 156 . In such cases, the voice recognition application provides the best possible recognition of the provided reconstructed signal, where the provided reconstructed signal may be at a lower quality level than the original input audio stream 102 .
FIG. 4 is a flowchart of an exemplary audio encoding process 400 using a sample rate with linear interpolation. For example, referring to FIGS. 1A and 1B , the first computing device 152 can perform the process 400 in order to encode the input audio stream 102 , generate the data blocks 104 , and transmit the data blocks 104 .
FIG. 5 is a block diagram showing exemplary sample rate encoding 500 . For example, referring to FIG. 1B , the first computing device 152 can perform the exemplary sample rate encoding 500 .
Referring to FIGS. 1A , 1 B, 4 and 5 , the process 400 begins by determining the sample rate of the original data ( 402 ). For example, the first computing device 152 determines that the sample rate of the original audio input stream 102 is 16 kHz. In general, and to account for the Nyquist frequency, an audio signal sampled at 16 kHz contains data at frequencies from 0-8 kHz. The process 400 sub-samples the original data at a first fraction of the sample rate ( 404 ). The sub-sampled rate for the data is less than the original sample rate for the data. In some implementations, the first computing device 152 determines the fraction of the sample rate based on the number of sub-samples of the original data needed to reproduce all of the original data. In addition, the first computing device 152 can select the fraction of the sample rate such that the resultant sub-sample rate is a multiple of the original sample rate for the audio input stream. For example, the first fraction is ¼ and the original sample rate for the audio input stream 102 is 16 kHz. The first computing device 152 sub-samples (down-samples) the audio input stream 102 at one-quarter of the sample rate of the original data (sub-sample at 4 kHz ( 504 )) obtaining one-quarter of the original audio input stream 102 (the data in the audio input stream at 2 kHz or less in the original 16 kHz audio input stream 102 ; i.e., ¼ of the 8 kHz Nyquist frequency). This results in the approximate size of the sub-sampled data being 25% of the size of the original data. In some implementations, the sub-sampling process can involve the use of a down-sampling anti-aliasing filter to eliminate artifacts from occurring in the sub-sampled audio signal.
The process 400 generates an initial data block based on the sub-sampled data ( 406 ). For example, the first computing device 152 generates data block 104 a that includes the encoded sub-sampled data (data sampled at 4 kHz from the original 16 kHz audio input stream 102 ). This results in the size of the data block 104 a being approximately 25% of the size of the original data. The process 400 compresses the initial data block ( 408 ). In some implementations, the first computing device 152 can compress the data in the data block 104 a using one of many available lossless data compression techniques. The lossless data compression techniques can include but are not limited to Huffman coding, Rice coding, free lossless audio codec (FLAG), and linear prediction (or linear predictive coding (LPC)). In some implementations, the first computing device 152 may digitally represent the uncompressed data using raw pulse-code modulation (PCM) (e.g., a sequence of numbers). The process 400 transmits the initial data block ( 410 ). For example, the first computing device 152 transmits data block 104 a to the second computing device 156 using the network 154 .
The process 400 up-samples the initial data block from the first fraction of the sample rate to the original sample rate to generate initial up-sampled data at the original sample rate ( 412 ). For example, the first computing device 152 decompresses the data in data block 104 a and up-samples the data from 4 kHz to 16 kHz ( 510 ) producing initial up-sampled data 512 at a 16 kHz rate that includes data in only one-quarter of the signal (data at 2 kHz or less). The initial up-sampled data 512 is subtracted from the original data ( 514 ) to produce a first low entropy residual signal that includes first residual data 516 at the frequency rate of the original audio input stream ( 414 ). For example, the first computing device 152 subtracts the initial up-sampled data 512 (the up-sampled signal at 16 kHz that includes data in only one-quarter of the signal (data at 2 kHz and below)) from the original audio input stream 102 with a sampling rate of 16 kHz. The resultant first low entropy residual signal includes first residual data 516 in three-quarters of the 16 kHz signal (data at frequencies between 2 kHz and 8 kHz).
The process 400 sub-samples the first residual data at a second fraction of the sample rate ( 416 ). The first computing device 152 can select the second fraction of the sample rate to provide additional data for the original audio input stream not provided by the sub-sampling of the original audio input stream at the first fraction of the sample rate. For example, the second fraction is ½ and the original sample rate for the audio input stream 102 is 16 kHz. The first computing device 152 sub-samples the first residual data at one-half of the sample rate of the original data (sub-sample at 8 kHz ( 518 )) obtaining one-half of the first residual data (data at 4 kHz or below; i.e., ½ of the 8 kHz Nyquist frequency of the original audio input stream). The obtained one-half of the first residual data includes one-quarter of the data from the original audio input stream 102 (the data in the audio input stream from 2 kHz to 4 kHz as the data at 2 kHz and below was subtracted from the original audio input stream 102 to produce the first low entropy residual data.) This results in the approximate size of the sub-sampled data being 25% of the size of the original data. In some implementations, the sub-sampling process can involve the use of a down-sampling anti-aliasing filter to eliminate artifacts from occurring in the sub-sampled audio signal.
The process 400 generates an intermediate data block based on the sub-sampled first residual data ( 418 ). For example, the first computing device 152 generates data block 104 b that includes the encoded sub-sampled first residual data (data sampled at 4 kHz from the original 16 kHz audio input stream 102 that includes data from 2 kHz to 4 kHz). This results in the size of the data block 104 a being approximately 25% of the size of the original data. The process 400 compresses the intermediate data block ( 420 ) using any of the previously described lossless data compression techniques. In some implementations, the first computing device may digitally represent the uncompressed data using raw PCM. The process 400 transmits the intermediate data block ( 422 ). For example, the first computing device 152 transmits data block 104 b to the second computing device 156 using the network 154 .
The process 400 up-samples the intermediate data block from the second fraction of the sample rate to the original sample rate to generate intermediate up-sampled data at the original sample rate ( 424 ). For example, the first computing device 152 decompresses the data in data block 104 b and up-samples the data in the data block 104 b from 8 kHz to 16 kHz ( 522 ) producing intermediate up-sampled data 524 at a 16 kHz rate that includes data in only one-quarter of the signal (data from 2 kHz to 4 kHz). The intermediate up-sampled data 524 is subtracted from the first residual data ( 526 ) to produce a second low entropy residual signal that includes remaining residual data 528 at the frequency rate of the original audio input stream ( 426 ). For example, the first computing device 152 subtracts the intermediate up-sampled data 524 (the up-sampled signal at 16 kHz that includes data in only one-quarter of the signal (data between 2 kHz and 4 kHz)) from the first residual data 526 (a data signal at 16 kHz that includes residual data above 2 kHz) resulting in remaining residual data 528 . The remaining residual data 528 is included in a data signal at 16 kHz, where the residual data is in the signal at frequencies above 4 kHz.
The process 400 generates a final data block based on the remaining residual data ( 428 ). For example, the first computing device 152 generates data block 104 c that includes the remaining residual data 528 . This results in the size of the data block 104 c being approximately 50% of the size of the original data. The process 400 compresses the final data block ( 430 ). In some implementations, the first computing device 152 can compress the data in the data block 104 c using one of many available lossless data compression techniques previously described. In some implementations, the first computing device may digitally represent the uncompressed data using raw PCM. The process 400 transmits the final data block ( 432 ). For example, the first computing device 152 transmits data block 104 c to the second computing device 156 using the network 154 . The process 400 ends.
In some implementations, the first computing device 152 can compress the sub-sampled data included in the data blocks using a lossy compression technique (e.g., Joint Photographic Experts Group (JPEG) compression). The lossy compression technique selected should preserve the phase information of the original audio input stream data. Preserving the phase information of the data can prevent the residual data signal (generated by subtracting the up-sampled data (up-sampled from the sub-sampled data) from the original data) from having a large magnitude and high entropy. A lossy compression technique can be used for compressing the sub-sampled data without the loss of any of the original audio input stream data due to the computation and transmission of residual data. For example, referring to FIG. 4 , the process 400 can compress a data block using a lossy compression technique. The data block prior to compression includes data from the original audio input stream at and below a particular frequency. When compressing the data block data using a lossy compression technique, some of the data in the original audio input stream at and below the selected frequency may be lost (not included) in the compression. The process 400 further decompresses and up-samples the data block to the original sample rate to generate up-sampled data. The up-sampled data will include only the data previously compressed and none of the lost data. The up-sampled data is then subtracted from the original audio input stream data resulting in residual data that includes data above the selected frequency and the data at and below the selected frequency that was lost in the previous compression. The lost data can then be included in the next data block, which may or may not be compressed. For example, referring to FIG. 5 , the initial data block 104 a and the intermediate data block 104 b can be compressed using a lossy compression technique. Any data lost by the lossy compressions can be present in the remaining residual data 528 that can be transmitted uncompressed or compressed using a lossless compression technique before transmission. The lossless compression of the remaining residual data or not compressing the remaining residual data can ensure the transmission of any data lost from previous lossy compression techniques for previously transmitted data blocks.
Referring to the example process 400 in FIG. 4 and referring to FIG. 1B , the first computing device 152 generates and transmits the encoded audio input stream using three data blocks. Other implementations of the process 400 may generate and transmit a different number of data blocks. The number of data blocks generated can depend on one or more factors that can include but are limited to the sampling rate of the original audio input stream, the selected sub-sampling rate of the original audio input stream, the bandwidth of the network connection between the transmitting device and the receiving device, and the latency time required for receipt of the results of the audio input stream. In some implementations, the transmitted data blocks can be a combination of compressed and uncompressed data blocks where the compression techniques can be a combination of lossy and lossless techniques.
FIG. 6 is a flowchart of an exemplary audio decoding process 600 using a sample rate with linear interpolation. For example, referring to FIGS. 1A and 1B , the second computing device 156 can perform the process 600 in order to receive the data blocks 104 , decode the data blocks 104 , and reconstruct the input audio stream 102 .
Referring to FIGS. 1A , 1 B, 4 and 6 , the process 600 begins by receiving the initial data block ( 602 ). The initial data block can include sub-sampled data. For example, the first computing device 152 transmits data block 104 a using the network 154 to the second computing device 156 . The process 600 decompresses the initial data block ( 604 ). For example, as previously described, the first computing device 152 can compress the data in the data block 104 a using one of many available lossy or lossless data compression techniques. In some implementations, the first computing device 152 may not compress the data in the data block 104 a . The second computing device 156 can decompress the data block 104 a . The process 600 then up-samples the decompressed data of the initial data block from the first fraction of the sample rate to the original sample rate ( 606 ). For example, the second computing device 156 up-samples the data in the data block 104 a from the 4 kHz sub-sampling rate to the 16 kHz original sample rate producing initial up-sampled data at a 16 kHz rate that includes data in only one-quarter of the signal (data at 2 kHz or less). The initial up-sampled data at the original sample rate is used as the initial reconstructed signal ( 608 ). The initial reconstructed signal can be a low sample rate version of the original audio input stream.
The process 600 receives the intermediate data block ( 610 ). The intermediate data block can include sub-sampled data. For example, the first computing device 152 transmits data block 104 b using the network 154 to the second computing device 156 . The process 600 decompresses the intermediate data block ( 612 ). For example, as previously described, the first computing device 152 can compress the data in the data block 104 b using one of many available lossy or lossless data compression techniques. In some implementations, the first computing device 152 may not compress the data in the data block 104 b . The second computing device 156 can decompress the data block 104 b . The process 600 then up-samples the decompressed data of the intermediate data block from the second fraction of the sample rate to the original sample rate ( 614 ). For example, the second computing device 156 up-samples the data in the data block 104 b from the 8 kHz sub-sampling rate to the 16 kHz original sample rate producing intermediate up-sampled data at a 16 kHz rate that includes data in only one-quarter of the signal (data from 2 kHz to 4 kHz) as the intermediate data block is a sub-sample of the first residual data. In some implementations, when lossy compression techniques are used, data may be included at frequencies below 2 kHz. The process 600 adds the intermediate up-sampled data to the initial reconstructed signal to produce an intermediate reconstructed signal ( 616 ). The intermediate reconstructed signal can be an intermediate sample rate version of the original audio input stream. For example, the intermediate reconstructed signal includes data at frequencies of 8 kHz and below from the original 16 kHz audio input stream 102 (effectively half of the original audio input stream).
The process 600 receives the final data block ( 618 ). The final data block can include the remaining residual data not included in previous data blocks. For example, the first computing device 152 transmits data block 104 c using the network 154 to the second computing device 156 . The process 600 decompresses the final data block ( 620 ). For example, as previously described, the first computing device 152 can compress the data in the data block 104 c using one of many available lossy or lossless data compression techniques. In some implementations, the first computing device 152 may not compress the data in the data block 104 c . The second computing device 156 can decompress the data block 104 c . The process 600 adds the decompressed residual data from the final data block to the intermediate reconstructed signal to produce a final reconstructed signal ( 622 ). The final reconstructed signal represents the original audio input stream 102 . The process 600 ends.
FIG. 7 is a flowchart of an exemplary audio encoding process 700 using bit depth. For example, and referring to FIGS. 1A and 1B , the first computing device 152 can perform the process 400 in order to encode the input audio stream 102 , generate the data blocks 104 , and transmit the data blocks 104 . The first computing device 152 can digitally record the input audio stream 102 resulting in multiple samples each having a specific bit depth representing the set of digital audio data for the audio input stream. The bit depth for each sample describes the number of bits of information recorded for each sample and directly corresponds to the resolution of each sample in the set of digital audio data.
Referring to FIGS. 1A , 1 B and 7 , the process 700 begins by setting an index i equal to one ( 702 ). The process 700 determines the bit depth N of the original data ( 704 ). For example, the process 700 determines the bit depth of the set of digital audio data for the audio input stream. The digital audio data comprises a series of samples where each sample is N bits. In some implementations, the first computing device 152 can digitize and encode the audio input stream 102 using an N bit linear PCM encoding technique. The process 700 extracts bit N−i of each sample ( 706 ). For example, when index i equals one, the process 700 extracts the most significant bit of each N bit sample. The process 700 generates a data block that includes the extracted bit for each N bit sample ( 708 ). The process 700 transmits the data block ( 710 ). For example, the first computing device 152 can transmit the data block (e.g., data block 104 a ) using network 154 to the second computing device 156 . If the index i is not equal to the bit depth N ( 712 ), bits of each N bit sample remain to be extracted and transmitted in a data block to the second computing device 156 by the process 700 . The process 700 determines if an additional data block should be generated and transmitted ( 714 ). If it is determined that an additional data block should be generated and transmitted, the process 700 increments the index i by one ( 716 ). The process then continues at 706 . If it is determined that an additional data block should not be generated and transmitted ( 714 ), the process 700 ends. If the index i is equal to the bit depth N ( 712 ), all bits of each N bit sample have been extracted and transmitted in a data block to the second computing device 156 by the process 700 . The process 700 ends.
In some implementations, the process 700 may determine that there is no longer a need to generate and transmit any further data blocks ( 714 ). For example, the second computing device 156 can inform the first computing device 152 that a voice recognition application has recognized the input audio stream from the data included in the data blocks already received by the second computing device 156 and no further data blocks are required in order to perform the voice recognition.
The process 700 encodes each block of data for the set of digital audio data for the audio input stream beginning with the most significant bit (N−1) of each N bit sample comprising the first block of data, the next most significant bit (N−2) of each N bit sample comprising the second block of data, proceeding until the last block of data comprised of the least significant bit (N−N=0) of each N bit sample. The process 700 can encode the data blocks directly as raw bits of data. The size of each data block is 1/N th the size of the original set of digital audio data for the audio input stream.
In some implementations, the audio input stream signal exhibits more energy (has more data present) at the lower frequency components of the signal as compared to the higher frequency components of the signal. As the frequency of the signal for the audio input stream increases, the numerical value for the digital representation of the signal for the sample also increases. Stated another way, higher frequency information is represented by a larger N bit value. As such, the exemplary audio encoding process 700 can include digital data in the first few data blocks (where higher frequency components of the audio input stream signal are represented in the first few most significant bits of each N bit sample) that can consist of long runs of “0”s or “1”s.
In some implementations, the audio input stream signal has a maximum amplitude that is lower than the recording equipment is capable of detecting. In this case, the digital representation of the audio input stream signal can include bits that may always be equal to zero, as the signal for those bits is undetected. In addition, a linear sixteen-bit encoding technique used for the digitization of the audio input stream signal can be chosen appropriately to avoid sign alternation. The choice of this particular type of linear sixteen-bit encoding can also contribute to the number of bits of the digitized audio input stream that may always be equal to zero.
In some of the implementations described, the digital data included in a data block can consist of long runs of “0”s or “1”s or may include bits that are always equal to zero. In these cases, the use of run length encoding for the digital data included in a data block can further reduce the size of the data block. For example, a reduced data block size can utilize less memory space on both the first computing device 152 and the second computing device 156 . In addition, the first computing device 152 transmits less data to the second computing device 156 resulting in reduced latency.
In some implementations, the transmitter (e.g., first computing device 152 ) can digitize and encode the audio input stream signal using a logarithmic encoding technique (e.g., a u-law algorithm). The use of a logarithmic encoding technique can reduce the dynamic range of the audio input stream signal. In general, the use of a logarithmic encoding technique may require fewer bits in order to represent the audio input stream signal resulting in fewer bits transmitted from the transmitter (e.g., first computing device 152 ) to the receiver (e.g., second computing device 156 ) while maintaining similar fidelity as compared to the original audio input stream signal.
FIG. 8 is a flowchart of an exemplary audio decoding process 800 using bit depth. For example, and referring to FIGS. 1A and 1B , the second computing device 156 can perform the process 800 in order to receive the data blocks 104 , decode the data blocks 104 , and reconstruct the input audio stream 102 .
Referring to FIGS. 1A , 1 B, 7 and 8 , the process 800 begins by setting an index i equal to one ( 802 ). The data block is received ( 804 ). For example, the first computing device 152 uses the process 700 to generate, encode and transmit data block 104 a using network 154 . The second computing device 156 receives the data block 104 a . The process 800 reconstructs the residual data signal based on bit N−i of each sample included in the data block ( 806 ). For example, the bit depth of the original data is equal to N. When the index i is equal to one, the data in the data block 104 a is the most significant bit of each N bit sample. The process 800 reconstructs a first residual data signal based on the most significant bit of each N bit sample included in data block 104 a . If the index i is equal to one ( 808 ), the process 800 checks if there are additional data blocks for receipt ( 814 ). If it is determined that an additional data block is not available for receipt ( 814 ), the process 800 ends. If it is determined that an additional data block is available for receipt ( 814 ), the process 800 increments the index i by one ( 816 ). For example, the index i is now equal to two. The process 800 then continues and receives the next data block ( 804 ). The process 800 reconstructs the residual data signal based on bit N−i of each sample included in the data block ( 806 ). For example, the first computing device 152 transmits data block 104 b that includes the N−2 bit (where the most significant bit is the N−1 bit) of each N bit sample. The process 800 receives data block 104 b . The process 800 reconstructs a second residual data signal based on the N−2 bit of each N bit sample included in data block 104 b . The index i is not equal to one ( 808 ). The process 800 adds the reconstructed residual data signal to the previous reconstructed data signal ( 810 ). The result is an updated reconstructed data signal that includes residual data based on the bit depth of the original input audio stream. For example, the process 800 adds the second reconstructed data signal to the first reconstructed data signal producing an updated reconstructed signal that is of a higher fidelity than the previous reconstructed signal as it includes an additional bit of data for each N bit sample. The process 800 checks if the index i is equal to the number of bits N in each sample ( 812 ). If the index i is not equal to the number of bits N in each sample, the process 800 checks if there are additional data blocks for receipt ( 814 ). If it is determined that an additional data block is available for receipt ( 814 ), the process 800 increments the index i by one ( 816 ). The process continues to receive the next data block ( 804 ). If it is determined an additional data block is not available for receipt ( 814 ), the process 800 ends. If the index i is equal to the number of bits N in each sample ( 812 ), the process 800 ends.
The processes 700 and 800 can be considered in the context of an audio signal transmission framework that produces progressively higher fidelity residual signals. A receiver (e.g., second computing device 156 in FIG. 1B ) receives residual signals generated and transmitted by a transmitter (e.g., first computing device 152 ). The receiver uses the residual signals to reconstruct a progressively higher fidelity signal. For example, the process 700 first generates and transmits the first data block, which includes data for the most significant bit of each N bit sample at a base residual signal fidelity. The process 800 receives the first data block and reconstructs the base residual signal. The next data block transmitted includes the data for the next most significant bit (N−2) of each N bit sample. The receiver reconstructs the residual signal and adds it to the base signal, generating a higher fidelity residual signal. The receiver generates and transmits each of the subsequent data blocks sequentially. The receiver receives the data blocks and sequentially reconstructs the audio input stream by adding each data block in sequence producing a progressively higher fidelity signal as each data block is added to the previously reconstructed signal. The receiver reconstructs each N bit sample of the audio input stream signal on a bit by bit basis, from the most significant bit to the least significant bit, resulting in a progressively higher fidelity reconstructed signal.
In some implementations, an audio signal transmission framework can combine the audio encoding process 400 using a sample rate with linear interpolation with the audio encoding process 700 using bit depth. A transmitter can generate a first data block that has a low sample rate and bit depth. For example, referring to FIGS. 1A and 1B , first computing device 152 can determine the sample rate of the original audio input stream 102 is 16 kHz. The first computing device 152 can sub-sample the audio input at a fraction of the sample rate (¼ of the sample rate resulting in a 4 kHz sub-sample rate). The first computing device 152 can determine the bit depth N of the original audio input stream 102 . The first computing device 152 can extract the most significant bit (the N−1 bit) for each N bit sample in the sub-sampled data to generate a residual data signal in data block 104 a where the first computing device 152 can additionally compress the data in the data block 104 a . The transmitter can generate a subsequent data block at the sub-sample rate that can increase the bit depth of the reconstructed residual data signal generated by the receiver. For example, the first computing device 152 generates, compresses and transmits the N−2 bit of each N bit sample at the 4 kHz sub-sample rate. Alternatively, the transmitter can generate a subsequent data block at a higher sub-sample rate and the same bit depth that can increase the sample rate of the reconstructed residual data signal generated by the receiver. For example, the first computing device 152 generates, compresses and transmits the most significant bit (the N−1 bit) of each N bit sample at an 8 kHz sub-sample rate. The transmitter can alternate between transmitting data blocks that can either increase the bit depth of the reconstructed residual data signal or increase the sample rate of the reconstructed residual data signal until the sample rate and bit depth of the reconstructed data signal equal the sample rate and bit depth of the original audio input stream. The transmitter can pre-determine the order in which to increase the sample rate and bit depths in order to maximize the incremental recognition accuracy achieved by each residual data signal produced by the receiver using each successive block of compressed residual data transmitted. In some implementations, the order in which the blocks are transmitted can be based on a priority level assigned to each block.
FIG. 9 is a flowchart of an exemplary audio encoding process 900 using linear predictive coding (LPC). LPC represents the spectral envelope of digital audio data in a compressed format using a linear predictive model. The linear predictive model uses a linear function (a predictor) that includes one or more previous values of a time series signal and one or more estimated predictor coefficients to predict (estimate) the next value of the time series signal. The predicted next value of the time series signal is the output of the predictor. An error term associated with the output forms another time series signal called the error residual. The complexity of the predictor can vary based on the amount of time it looks back in the input audio signal (the number of previous values of the time series signal used), the number of predictor coefficients used, and the complexity of the predictor coefficients. For example, a higher order predictor can use a higher order polynomial or other non-linear method.
The process 900 can use LPC to encode an initial block of digital audio data generated from the original audio input stream. For the initial encoded block of data, the process 900 can transmit information that describes the predictor (e.g., the set of predictor coefficients) used in the LPC of the original audio signal and a residual signal. The residual signal is the difference between the output of the predictor and the original audio input stream.
A first data block generated by the process 900 provides a first pass encoding of the audio input stream using a base LPC encoding technique. In some implementations, the process 900 can use alternative LPC encoding techniques to encode the residual data from the previous data blocks to generate subsequent data blocks. The predictor for the alternative LPC encoding technique can be more complex as compared to the predictor for the base LPC encoding technique. For example, an alternative LPC encoding technique can use a larger number of predictor coefficients (e.g., a longer prediction filter) than the base LPC encoding technique. For example, the alternative LPC encoding technique can implement a higher order predictor that uses a higher degree time series expansion of the audio input stream using, for example, higher order polynomials and other additional non-linear mappings. The process 900 can use progressively higher order predictors in the alternative LPC technique used to generate each subsequent data block to encode the residual data of the previous data block as each data block progressively decreases in size.
For example, and referring to FIGS. 1A , 1 B and 9 , the first computing device 152 can perform the process 900 in order to encode the input audio stream 102 , generate the data blocks 104 , and transmit the data blocks 104 . The process 900 begins by generating an initial data block using an initial LPC technique based on a first number of predictor coefficients ( 902 ). For example, the first computing device 152 generates data block 104 a using the initial LPC technique on the audio input stream 102 . The initial LPC technique uses two predictor coefficients (looks back two samples into the audio input stream 102 ). The data block 104 a includes the two predictor coefficients used in the LPC of the audio input stream 102 and an initial residual data signal. The initial residual data signal is the difference between the output of the predictor used in the initial LPC and the audio input stream 102 .
The process 900 transmits the initial data block ( 904 ). For example, the first computing device 152 transmits data block 104 a to the second computing device 156 using the network 154 . The process 900 determines if an additional data block can be generated and transmitted ( 906 ). If it is determined that an additional data block should not be generated and transmitted ( 906 ), the process 900 ends. If it is determined that an additional data block can be generated and transmitted ( 906 ), the process 900 continues at 907 . If it is determined that the current data block is not the final data block ( 907 ), the process 900 continues at 908 . The process 900 generates a subsequent data block using an alternative LPC technique on the data in the previous data block ( 908 ). The alternative LPC technique uses a larger number of predictor coefficients than the initial LPC technique. For example, the first computing device 152 generates data block 104 b using an alternative LPC technique on the initial residual data signal included in the previous data block 104 a . The alternative LPC technique uses four predictor coefficients (looks back four samples into the residual data of data block 104 a ). The data block 104 b includes the four predictor coefficients used in the LPC of the initial residual data signal and a second residual data signal. The second residual data signal is the difference between the output of the predictor used in the alternative LPC and the original audio input stream 102 . The process 900 transmits the subsequent data block ( 910 ).
If it is determined that the current data block is the final data block ( 907 ), the process 900 continues at 912 where the residual data is encoded. For example, the final data block includes the raw remaining residual data without the use of LPC. The first computing device 152 can determine the remaining residual data signal by subtracting the residual data signal from each of the previous data blocks from the original audio input stream 102 resulting in the remaining residual data. In some implementations, the final data block can be compressed using one of the lossless compression encoding schemes previously described (e.g., a Huffman encoding or Rice encoding). The process 900 transmits the subsequent (in this case the final) data block ( 910 ). If it is determined that there are no additional data blocks ( 906 ), the process 900 ends.
In some implementations, the first computing device 152 can base the determination for generation of additional data blocks ( 906 ) on the receipt of a request for an additional data block from the second computing device 156 . For example, if a voice recognition application on the second computing device 156 can recognize the input audio stream prior to the first computing device 152 transmitting all of the possible data blocks, the second computing device 156 can instruct the first computing device 152 not to transmit subsequent data blocks. In some implementations, the first computing device 152 can base the determination for generation of additional data blocks ( 906 ) on a timer. If the set time for the timer has expired, the process 900 may no longer generate and transmit additional data blocks.
FIG. 10 is a flowchart of an exemplary audio decoding process 1000 using linear predictive coding. For example, referring to FIGS. 1A and 1B , the second computing device 156 can perform the process 1000 in order to receive the data blocks 104 , decode the data blocks 104 , and reconstruct the input audio stream 102 .
Referring to FIGS. 1A , 1 B, 9 and 10 , the process 1000 begins by receiving an initial data block ( 1002 ). The initial data block includes the predictor coefficients (a first number of coefficients) used by the initial LPC technique in the process 900 . For example, data block 104 a includes the two predictor coefficients used by the initial LPC technique. The process 1000 begins reconstructing a first data signal using the first number of predictor coefficients ( 1004 ). The resultant reconstructed signal is the base reconstructed signal. For example, the process 1000 reconstructs the first data signal using the two coefficients in the data block 104 a . The process 1000 determines if there are additional data blocks for receipt ( 1006 ). If it is determined that an additional data block is not available for receipt ( 1006 ), the process 1000 ends. If it is determined that an additional data block is available for receipt ( 1006 ), the process 1000 receives a subsequent data block ( 1008 ). For example, the first computing device 152 transmits the data block 104 b using network 154 . The second computing device 156 receives the subsequent data block 104 b . The second data block 104 b includes the initial residual data signal, which is the difference between the output of the initial LPC predictor and the audio input stream 102 . If it is determined that this is not the final data block ( 1010 ), the process 1000 reconstructs a subsequent signal using an alternative number of predictor coefficients and residual data ( 1012 ). The subsequent data block includes the predictor coefficients (an alternative number of coefficients) used by the alternative LPC technique in the process 900 and a subsequent residual data signal. For example, data block 104 c includes the four predictor coefficients used by the alternative LPC technique. In addition, the data block 104 c includes the second residual data signal, which is the difference between the output of the predictor used in the alternative LPC and the original audio input stream 102 . The process 1000 reconstructs a subsequent data signal using the four predictor coefficients and the second residual data signal. The process 1000 adds the reconstructed subsequent data signal to the base reconstructed signal ( 1016 ). The addition of the reconstructed subsequent data signal to the base reconstructed signal results in the updating of the base reconstructed signal. The process 1000 determines whether there are additional data blocks for receipt ( 1006 ).
The process 1000 receives a subsequent data block ( 1008 ). If it is determined that this is the final data block ( 1010 ), the process 1000 decodes the data block ( 1014 ). The final data block is a reconstructed subsequent data block that includes raw residual data. In some implementations, the final data block can include raw residual data that is compressed using a lossless compression technique. The process 1000 in addition can decompress the raw residual data in the final data block prior to decoding the data. The process 1000 adds the reconstructed subsequent data signal to the base reconstructed signal ( 1016 ). The addition of the reconstructed subsequent data signal to the base reconstructed signal results in the updating of the base reconstructed signal. The process 1000 at 1006 , where it is determined that there are no more additional data blocks. The process 1000 ends.
In some implementations, a transmitter can use perceptual coding techniques that apply lossy audio compression to generate, encode and transmit audio data blocks. For example, the human brain may not process all frequencies of an audio input stream in the same manner. Some frequencies can be compressed or removed entirely from the audio input stream without any adverse effect. The perceptual coding techniques can use a psychoacoustic model to identify those frequencies that can be aggressively compressed or even eliminated from an audio input stream with no perceived difference noted by a listener.
When applied in the context of an audio signal transmission framework that produces progressively higher fidelity residual signals, a perceptual coding technique can aggressively reduce the fidelity of the audio input stream in the first data block. The perceptual coding technique can apply progressively less aggressive encoding of each residual data signal to produce the remaining sequential data blocks.
Existing audio encoding techniques such as code-excited linear prediction (CELP), which can be used as a basis for codecs designed to compress an audio input stream, can also be extended for use in the context of an audio signal transmission framework. For example, audio encoders may use vector quantization to compress various parts of the audio input stream such as the excitation signal or the residual. The audio signal transmission framework can generate sequential data blocks where the parameters that can be varied or augmented with each block can include the resolution of the vector quantization or the size of the codebook.
In some implementations, an audio signal transmission framework can use perceptual coding techniques for compressing the residual signal in the processes described with reference to FIGS. 4 , 7 , and 9 .
In general, the sequential data blocks generated by a transmitter can form a directed acyclic graph or tree. The transmitter can take different paths along the tree as long as the receiver receives all the data blocks needed in order to make use of the currently received data block. For example, the root node is the first (or initial) data block. Each node is labeled with the priority level of its associated data block. For example, an edge points from node A to node B. The edge requires the transmission of node A before node B in order for the receiver to receive the information in block A before the information in block B. The receiver may need the information in node A in order to make use of the information in the received block B. For example, in the progressive encoding techniques described with reference to FIGS. 4 , 7 , and 9 , the tree can be a chain comprising each node in the sequence of data blocks. In some implementations, the transmitter may transmit data blocks that include additional information, such as audio prologue information, if the receiver has already received at least one data block. The dependencies between nodes are expressed as edges in the graph. The transmitter uses an algorithm to determine the order in which to transmit the data blocks. In some implementations, the transmitter can pre-code the algorithm prior to the transmission of the data blocks. In some implementations, the transmitter can construct the tree as it generates and transmits the data blocks. For example, the transmitter can produce a last functional tree where a complete map of the tree is constructed as the data blocks are generated. For example, the transmitter selects the highest priority node (e.g., node B) for which every previous node (e.g., node A) that has an edge from that node (e.g., node A) to the selected node (e.g., node B) has already been transmitted. In most cases, the root of the tree will be the first node to be transmitted as it has no edges pointing to it.
In the processes described with reference to FIGS. 1A , 1 B and 2 to 9 , a transmitter sends data blocks in sequence to a receiver that reconstructs the audio signal as it receives each block. In addition, the receiver runs a voice recognition process. In some implementations, either the transmitter or receiver can decide that the transmitter has transmitted sufficient data blocks. In some implementations, the receiver can monitor the voice recognition process to determine the value of the recognizer's confidence signal. When the voice recognizer has received sufficient data blocks to recognize the speech in the reconstructed audio input stream with sufficient confidence, the receiver can signal to the transmitter to stop sending further blocks. In addition, the transmitter can transmit the recognition result.
In some implementations, the receiver or transmitter can monitor how much time has elapsed since the user finished speaking. If this time exceeds some pre-set threshold (e.g. 10 seconds), the transmitter can stop transmitting data blocks. In addition, the receiver can transmit the recognition result to the transmitter without regard to the confidence level of the voice recognizer.
In some implementations, a heuristic score can combine the confidence level of the recognizer with a measure of how much time has elapsed since the user finished speaking. When the heuristic score crosses a predetermined threshold level, the transmitter can halt the data block generation and transmission process. In some cases, (e.g., fast networks or in noisy environments) all possible data blocks may be generated and transmitted before this predetermined threshold is reached.
The processes described with reference to FIGS. 1A , 1 B and 2 to 9 can be applied to a short segment of speech being transmitted once for use in an application (e.g., a voice search application). In other applications, a user may be dictating a long message (e.g., dictating an electronic mail (email) message). In these applications, the transmitter can break the audio input stream into a sequence of short segments or chunks for the purpose of voice recognition. The transmitter can use a segmenting method (e.g., endpointing or voice activity detection) to segment the audio input stream. In these applications, the processes described with reference to FIGS. 1A , 1 B and 2 to 9 can be applied to each segment to generate, transmit, and receive the multiple data blocks per segment. In some implementations, the receiver can determine whether a sufficient number of data blocks are transmitted based on the need to meet real-time transmission criteria. For example, the receiver may signal the transmitter to stop the transmission of the data blocks for one segment of the audio input stream as soon as it is possible to begin transmitting blocks for the next segment of the audio input stream. For example, an audio signal transmission framework can integrate the transmission techniques for long messages into an audiovisual transmission protocol such as RTP (Real-Time Transport Protocol). The receiver can use RTTP control packets to signal when the transmitter should stop sending data blocks. In some implementations, the transmitter needs to keep up with the real time audio input stream as it generates and transmits data blocks to the receiver for each segment of the audio input stream. The transmitter can determine to transmit the remaining data blocks for the current audio input stream segment or to begin transmitting the data blocks for the next audio input stream segment.
A number of implementations have been described. Nevertheless, it will be understood that various modifications may be made without departing from the spirit and scope of the disclosure. For example, various forms of the flows shown above may be used, with steps re-ordered, added, or removed. Accordingly, other implementations are within the scope of the following claims.
Implementations of the present disclosure and all of the functional operations provided herein can be realized in digital electronic circuitry, or in computer software, firmware, or hardware, including the structures disclosed in this specification and their structural equivalents, or in combinations of one or more of them. Implementations of the present disclosure can be realized as one or more computer program products, i.e., one or more modules of computer program instructions encoded on a computer readable medium for execution by, or to control the operation of, data processing apparatus. The computer readable medium can be a machine-readable storage device, a machine-readable storage substrate, a memory device, a composition of matter effecting a machine-readable propagated signal, or a combination of one or more of them. The term “data processing apparatus” encompasses all apparatus, devices, and machines for processing data, including by way of example a programmable processor, a computer, or multiple processors or computers. The apparatus can include, in addition to hardware, code that creates an execution environment for the computer program in question, e.g., code that constitutes processor firmware, a protocol stack, a database management system, an operating system, or a combination of one or more of them.
A computer program (also known as a program, software, software application, script, or code) can be written in any form of programming language, including compiled or interpreted languages, and it can be deployed in any form, including as a stand alone program or as a module, component, subroutine, or other unit suitable for use in a computing environment. A computer program does not necessarily correspond to a file in a file system. A program can be stored in a portion of a file that holds other programs or data (e.g., one or more scripts stored in a markup language document), in a single file dedicated to the program in question, or in multiple coordinated files (e.g., files that store one or more modules, sub programs, or portions of code). A computer program can be deployed to be executed on one computer or on multiple computers that are located at one site or distributed across multiple sites and interconnected by a communication network.
The processes and logic flows described in this disclose can be performed by one or more programmable processors executing one or more computer programs to perform functions by operating on input data and generating output. The processes and logic flows can also be performed by, and apparatus can also be implemented as, special purpose logic circuitry, e.g., an FPGA (field programmable gate array) or an ASIC (application specific integrated circuit).
Processors suitable for the execution of a computer program include, by way of example, both general and special purpose microprocessors, and any one or more processors of any kind of digital computer. Generally, a processor will receive instructions and data from a read only memory or a random access memory or both. The essential elements of a computer are a processor for performing instructions and one or more memory devices for storing instructions and data. Generally, a computer will also include, or be operatively coupled to receive data from or transfer data to, or both, one or more mass storage devices for storing data, e.g., magnetic, magneto optical disks, or optical disks. However, a computer need not have such devices. Moreover, a computer can be embedded in another device, e.g., a mobile telephone, a personal digital assistant (PDA), a mobile audio player, a Global Positioning System (GPS) receiver, to name just a few. Computer readable media suitable for storing computer program instructions and data include all forms of non volatile memory, media and memory devices, including by way of example semiconductor memory devices, e.g., EPROM, EEPROM, and flash memory devices; magnetic disks, e.g., internal hard disks or removable disks; magneto optical disks; and CD ROM and DVD-ROM disks. The processor and the memory can be supplemented by, or incorporated in, special purpose logic circuitry.
Implementations of the present disclosure can be realized on a computer having a display device, e.g., a CRT (cathode ray tube) or LCD (liquid crystal display) monitor, for displaying information to the user and a keyboard and a pointing device, e.g., a mouse or a trackball, by which the user can provide input to the computer. Other kinds of devices can be used to provide for interaction with a user as well; for example, feedback provided to the user can be any form of sensory feedback, e.g., visual feedback, auditory feedback, or tactile feedback; and input from the user can be received in any form, including acoustic, speech, or tactile input.
Implementations of the present disclosure can be realized in a computing system that includes a back end component, e.g., as a data server, or that includes a middleware component, e.g., an application server, or that includes a front end component, e.g., a client computer having a graphical user interface or a Web browser through which a user can interact with an implementation of the present disclosure, or any combination of one or more such back end, middleware, or front end components. The components of the system can be interconnected by any form or medium of digital data communication, e.g., a communication network. Examples of communication networks include a local area network (“LAN”) and a wide area network (“WAN”), e.g., the Internet.
The computing system can include clients and servers. A client and server are generally remote from each other and typically interact through a communication network. The relationship of client and server arises by virtue of computer programs running on the respective computers and having a client-server relationship to each other.
While this disclosure contains many specifics, these should not be construed as limitations on the scope of the disclosure or of what may be claimed, but rather as descriptions of features specific to particular implementations of the disclosure. Certain features that are described in this disclosure in the context of separate implementations can also be provided in combination in a single implementation. Conversely, various features that are described in the context of a single implementation can also be provided in multiple implementations separately or in any suitable subcombination. Moreover, although features may be described above as acting in certain combinations and even initially claimed as such, one or more features from a claimed combination can in some cases be excised from the combination, and the claimed combination may be directed to a subcombination or variation of a subcombination.
Similarly, while operations are depicted in the drawings in a particular order, this should not be understood as requiring that such operations be performed in the particular order shown or in sequential order, or that all illustrated operations be performed, to achieve desirable results. In certain circumstances, multitasking and parallel processing may be advantageous. Moreover, the separation of various system components in the implementations described above should not be understood as requiring such separation in all implementations, and it should be understood that the described program components and systems can generally be integrated together in a single software product or packaged into multiple software products.
In each instance where an HTML file is mentioned, other file types or formats may be substituted. For instance, an HTML file may be replaced by an XML, JSON, plain text, or other types of files. Moreover, where a table or hash table is mentioned, other data structures (such as spreadsheets, relational databases, or structured files) may be used.
Thus, particular implementations of the present disclosure have been described. Other implementation s are within the scope of the following claims. For example, the actions recited in the claims can be performed in a different order and still achieve desirable results. A number of implementations have been described. Nevertheless, it will be understood that various modifications may be made without departing from the spirit and scope of the disclosure. For example, various forms of the flows shown above may be used, with steps re-ordered, added, or removed. Accordingly, other implementations are within the scope of the following claims. | The present disclosure includes processing a signal to generate a first sub-set of data, transmitting the first sub-set of data for generation of a reconstructed audio signal, the reconstructed audio signal having a fidelity relative to the signal, processing the signal to generate a second sub-set of data and a third sub-set of data, the second sub-set of data defining a second portion of the signal and comprising data that is different than data of the first sub-set of data, and the third sub-set of data defining a third portion of the signal and comprising data that is different than data of the first and second sub-sets of data, comparing a priority of the second sub-set of data to a priority of the third sub-set of data, and transmitting one of the second sub-set of data and the third sub-set of data over the network for improving the fidelity. | 6 |
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] The present application is a continuation of International Application No. PCT/KR2012/003294 filed on Apr. 27, 2012, which claims priority to Korean Application No. 10-2011-0040327 filed on Apr. 28, 2011 and Korean Application No. 10-2012-0044489 filed on Apr. 27, 2012, which applications are incorporated herein by reference.
TECHNICAL FIELD
[0002] The present invention relates to a horizontal thermoelectric tape and a method of manufacturing the same, and more particularly, to a horizontal thermoelectric tape which is capable of effectively shielding electromagnetic waves and exhibits superior heat dissipation effects, and to a method of manufacturing the same.
BACKGROUND ART
[0003] Typical operation of electronic products generates heat from electronic elements included in the electronic products.
[0004] As such, if the heat thus generated is not dissipated outside as quickly as possible, it negatively affects the electronic elements, which undesirably deteriorates functions of the electronic elements. This heat may cause noise and malfunction of peripheral parts or devices, and the lifetime of the products may decrease.
[0005] In particular, with the trend of manufacturing electronic products having high performance and functionality while being light, slim, short and small, there is an essential need for an increase in capacity and integration of electronic elements. How to effectively dissipate heat generated from the parts of electronic products is regarded as an important factor of determining performance and quality of the products.
[0006] Conventionally, in order to solve the above problems, although heat generated from electronic elements is removed using a fin fan process, a Peltier cooling process, a water-jet cooling process, an immersion cooling process, a heat pipe cooling process, etc., electronic elements require appropriate cooling and heat dissipation units so as to be adapted for electronic products which are manufactured to be slim and small these days.
[0007] Moreover, with the recent advance of electronics and telecommunications industries, the use of notebook computers, mobile phones and so on is widespread, and thus a process of removing heat by attaching a heat dissipation tape to such products, which are lighter and slimmer, is preferred.
[0008] However, conventional heat dissipation tape products are problematic because an adhesive layer and a heat dissipation layer are separately provided, which undesirably decreases heat dissipation efficiency, and also because the manufacturing process thereof is complicated. Also, conventional heat dissipation tape products include a conductive substrate formed using a deposition process, and are disadvantageous in terms of having low heat conductivity.
SUMMARY
[0009] Accordingly, the present invention has been made keeping in mind the above problems occurring in the related art, and an object of the present invention is to provide a horizontal thermoelectric tape and a method of manufacturing the same, wherein electromagnetic waves generated from certain devices and electronic elements at predetermined positions are shielded, and heat generated therefrom is effectively removed, thus exhibiting superior heat dissipation effects and heat conductivity.
[0010] In order to accomplish the above object, an aspect of the present invention provides a horizontal thermoelectric tape, suitable for use in shielding electromagnetic waves generated from an electronic element, transferring heat generated from the electromagnetic waves to the outside and having heat conductivity, the horizontal thermoelectric tape comprising a conductive substrate 70˜120 μm thick comprising a metal foil formed of at least one metal selected from the group consisting of aluminum, copper and nickel, a PET layer formed on the upper surface of the conductive substrate, and a heat dissipation adhesive layer formed on the lower surface of the conductive substrate. Also, the heat dissipation adhesive layer may be formed using an adhesive and a graphite filler.
[0011] Furthermore, the graphite filler may have a diameter of 5˜15 μm. Moreover, the graphite filler may be used in an amount of 10˜15 parts by weight based on 100 parts by weight of the adhesive. Also, the heat dissipation adhesive layer may further comprise a flame retardant and a hardener. The flame retardant may comprise at least one selected from the group consisting of aluminum hydroxide (Al(OH) 3 , magnesium hydroxide (Mg(OH) 2 ) and a phosphorus-based flame retardant. The hardener may comprise at least one selected from the group consisting of isocyanate, amine and epoxy.
[0012] Another aspect of the present invention provides a method of manufacturing a horizontal thermoelectric tape, comprising applying a heat dissipation adhesive onto the lower surface of a conductive substrate having PET attached to the upper surface thereof and comprising a metal foil 70˜120 μm thick formed of at least one metal selected from the group consisting of aluminum, copper and nickel, and laminating a releasable film on a surface of the heat dissipation adhesive opposite the surface thereof applied onto the conductive substrate. Also, the heat dissipation adhesive may be prepared by mixing an adhesive and a graphite filler to obtain a mixture which is then stirred. Furthermore, the graphite filler may have a diameter of 5˜15 μm. Moreover, the graphite filler may be used in an amount of 10˜15 parts by weight based on 100 parts by weight of the adhesive. Also, the heat dissipation adhesive may further comprise a flame retardant and a hardener. The flame retardant may comprise at least one selected from the group consisting of aluminum hydroxide (Al(OH) 3 ), magnesium hydroxide (Mg(OH) 2 ) and a phosphorus-based flame retardant. The hardener may comprise at least one selected from the group consisting of isocyanate, amine and epoxy.
[0013] According to the present invention regarding a horizontal thermoelectric tape and a method of manufacturing the same, heat generated from electronic elements can be effectively transferred and removed, and electromagnetic waves can be efficiently shielded. Specifically, the horizontal thermoelectric tape of the present invention unifies the double layer structure of a conventional horizontal thermoelectric tape including an adhesive layer and a heat dissipation layer, and is configured such that a conductive substrate is directly coated with a heat dissipation adhesive, thus increasing heat dissipation efficiency and simplifying the manufacturing process. Also, a non-deposited conductive substrate is used, resulting in a horizontal thermoelectric tape that has superior heat conductivity.
BRIEF DESCRIPTION OF DRAWINGS
[0014] FIG. 1 is a cross-sectional view illustrating a horizontal thermoelectric tape according to the present invention; and
[0015] FIG. 2 is a graph illustrating the results of measurement of effects of the horizontal thermoelectric tape according to the present invention on shielding electromagnetic waves.
DETAILED DESCRIPTION
[0016] Culminating in the present invention, intensive and thorough research carried out by the present inventors aiming to solve the problems encountered in the related art, led to development of a horizontal thermoelectric tape which unifies the double layer structure of an adhesive layer and a heat dissipation layer to form a single layer structure thus increasing heat dissipation efficiency and shielding electromagnetic waves and also in which a conductive substrate is not deposited thus exhibiting higher heat conductivity.
[0017] According to the present invention, a horizontal thermoelectric tape shields electromagnetic waves generated from electronic elements, transfers heat generated from such electromagnetic waves to the out side and has heat conductivity, and the horizontal thermoelectric tape includes a conductive substrate 70˜120 μm thick comprising a metal foil formed of at least one metal selected from the group consisting of aluminum, copper and nickel, a PET layer formed on the upper surface of the conductive substrate, and a heat dissipation adhesive layer formed on the lower surface of the conductive substrate.
[0018] The thickness of the conductive substrate is preferably set to 70˜120 μm. If the thickness of the conductive substrate is less than 70 μm, heat conductivity may decrease.
[0019] In contrast, if the thickness thereof exceeds 120 μm, it is difficult to finally manufacture a slim product due to the excessive thickness. Also, the conductive substrate preferably includes a metal foil, and the metal preferably includes at least one selected from the group consisting of aluminum, copper and nickel. When the metal comprising at least one selected from the group consisting of aluminum, copper and nickel is used, it may be formed into a conductive substrate without separate deposition, thereby further increasing heat conductivity. Furthermore, the conductive substrate, which is not damaged and contains no impurities, may be effectively formed, compared to when performing a deposition process.
[0020] Also, the heat dissipation adhesive layer is preferably formed from an adhesive and heat dissipation powder. The adhesive is preferably an acrylic adhesive or a silicone adhesive. In the heat dissipation adhesive layer, any material for the heat dissipation powder is not particularly limited so long as it imparts a heat dissipation effect, and preferable examples thereof include alumina and a graphite filler. Particularly useful is a graphite filler. In the case where graphite is used as the heat dissipation powder, the surface of the heat dissipation tape becomes smooth, positively affecting the outer appearance thereof and preventing damage to the heat dissipation tape itself. Also, when graphite is contained as the heat dissipation powder, the heat dissipation adhesive layer is prevented from being stripped from the conductive substrate, making it possible to provide a horizontal thermoelectric tape having higher adhesiveness. Furthermore, it is possible to provide a horizontal thermoelectric tape which is effectively maintained in adhesiveness even under external force applied to the horizontal thermoelectric tape. Although the graphite filler is not particularly limited in size, it preferably has a diameter of 5˜15 μm. If the diameter thereof is less than 5 μm, heat dissipation effects may deteriorate. In contrast, if the diameter thereof exceeds 15 μm, the surface of the tape may become coarse (Example 4). The graphite filler is preferably used in an amount of 10˜15 parts by weight based on 100 parts by weight of the adhesive. When the graphite filler is added in an amount less than 10 parts by weight, heat conductivity may decrease. In contrast, if the amount of the graphite filler exceeds 15 parts by weight, adhesion may decrease (Example 4).
[0021] Also, the heat dissipation adhesive layer preferably further includes a flame retardant and a hardener. The flame retardant may also be referred to as a flameproof agent, and is added to prevent combustion of the heat dissipation adhesive layer and generation of harmful gases upon combustion, and preferably includes at least one selected from the group consisting of aluminum hydroxide Al(OH) 3 ), magnesium hydroxide (Mg(OH) 2 ) and a phosphorus-based flame retardant. The hardener is used to enhance hardness of the heat dissipation adhesive layer, and preferably includes at least one selected from the group consisting of isocyanate, amine and epoxy.
[0022] In addition, according to the present invention, a method of manufacturing the horizontal thermoelectric tape includes applying a heat dissipation adhesive onto the lower surface of a conductive substrate having PET attached to the upper surface thereof and comprising a metal foil 70˜120 μm thick formed of at least one metal selected from the group consisting of aluminum, copper and nickel, and laminating a releasable film on a surface of the heat dissipation adhesive opposite the surface thereof applied onto the conductive substrate.
[0023] The thickness of the metal foil of the conductive substrate is preferably set to 70˜120 μm. If the thickness thereof is less than 70 μm, heat conductivity may decrease. In contrast, if the thickness thereof exceeds 120 μm, it is difficult to finally manufacture a slim product due to the excessive thickness. Also, the conductive substrate preferably includes a metal foil, and the metal preferably includes at least one selected from the group consisting of aluminum, copper and nickel. In the case where the metal comprising at least one selected from the group consisting of aluminum, copper foil and nickel is used, it may be formed into a conductive substrate without separate deposition, thus further increasing heat conductivity. Moreover, the conductive substrate, which is not damaged and contains no impurities, may be effectively formed, compared to when performing a deposition process. The heat dissipation adhesive may be prepared by mixing an adhesive and heat dissipation powder and stirring the mixture. The adhesive is preferably composed of an acrylic adhesive or a silicone adhesive. The heat dissipation powder may include at least one selected from the group consisting of a graphite filler, alumina, ceramic and carbon nanotubes. Particularly useful is a graphite filler. Although the graphite filler is not particularly limited in size, it preferably has a diameter of 5˜15 μm. If the diameter thereof is less than 5 μm, heat dissipation effects may deteriorate. In contrast, if the diameter thereof exceeds 15 μm, the surface of the tape may become coarse (Example 4). The graphite filler is preferably used in an amount of 10˜15 parts by weight based on 100 parts by weight of the adhesive. If the amount of the graphite filler is less than 10 parts by weight, heat conductivity may decrease. In contrast, if the amount thereof exceeds 15 parts by weight, adhesion may decrease (Example 4).
[0024] Also, the heat dissipation adhesive layer preferably further includes a flame retardant and a hardener. The flame retardant may also be referred to as a flameproof agent, and is added to prevent combustion of the heat dissipation adhesive layer and generation of harmful gases upon combustion, and preferably includes at least one selected from the group consisting of aluminum hydroxide (Al(OH) 3 ), magnesium hydroxide (Mg(OH) 2 ) and a phosphorus-based flame retardant. The hardener is added to enhance hardness of the heat dissipation adhesive layer, and preferably includes at least one selected from the group consisting of isocyanate, amine and epoxy.
[0025] A better understanding of the present invention may be obtained through the following examples which are set forth to illustrate, but are not to be construed to limit the present invention.
EXAMPLES
Example 1
Use of Metal Foil as Conductive Substrate
[0026] 100 parts by weight of an acrylic adhesive having a solid content of 45% was mixed with 11.1 parts by weight of a graphite filler having a diameter of 5˜15 μm as heat dissipation powder, and the mixture was uniformly dispersed using a high-speed stirrer for about 30˜60 min. Upon stirring, aluminum hydroxide as a flame retardant and an amine-based hardener were added. The resulting mixture was then stabilized at room temperature of about 20˜30° C. for about 30˜60 min so as to be defoamed, thus preparing a heat dissipation adhesive.
[0027] As a conductive substrate, a non-deposited metal foil 100 μm thick comprising an aluminum product (Metal foil SAMHWA, HANWHA aluminum product) was used. Furthermore, PET was attached to the upper surface of the conductive substrate.
[0028] Subsequently, the heat dissipation adhesive was applied onto the conductive substrate using a comma coater. As such, because the coating thickness is decreased due to evaporation of the solvent after drying, a coating was formed to be thicker by at least 40% than a desired thickness. Thereafter, the coated substrate was allowed to stand and aged at 40˜60° C. for 24 hr in a chamber so that the polymer of the heat dissipation adhesive was stabilized. Then, a releasable film was laminated on the conductive substrate so that a horizontal thermoelectric tape was usable in a state of being attached to a predetermined target. A final horizontal thermoelectric tape was configured such that the heat dissipation adhesive was 35 μm thick, the conductive substrate was 100 μm thick, and the PET coating layer including a bonding layer was 15 μm thick, resulting in a total thickness of 150 μm. FIG. 1 illustrates the horizontal thermoelectric tape of Example 1 configured such that the PET layer is provided on the upper surface of the conductive substrate and the heat dissipation adhesive layer is provided on the lower surface of the conductive substrate. In FIG. 1 , the reference numeral 100 designates a PET layer, the reference numeral 200 designates a conductive substrate including a metal foil, and the reference numeral 300 designates a heat dissipation adhesive layer.
Example 2
Use of Alumina as Heat Dissipation Powder
[0029] A horizontal thermoelectric tape was manufactured in the same manner as in Example 1, with the exception that alunina was used as the heat dissipation powder.
Example 3
Use of 8.8 Parts by Weight of Graphite Filler Based on 100 Parts by Weight of Acrylic Adhesive
[0030] A horizontal thermoelectric tape was manufactured in the same manner as in Example 1, with the exception that the graphite filler was used in an amount of 8.8 parts by weight based on 100 parts by weight of the acrylic adhesive.
Example 4
Use of 16.6 Parts by Weight of Graphite Filler Based on 100 Parts by Weight of Acrylic Adhesive
[0031] A horizontal thermoelectric tape was manufactured in the same manner as in Example 1, with the exception that the graphite filler was used in an amount of 16.6 parts by weight based on 100 parts by weight of the acrylic adhesive.
COMPARATIVE EXAMPLES
Comparative Example
Use of Deposited Conductive Substrate
[0032] A horizontal thermoelectric tape was manufactured in the same manner as in Example 1, with the exception that a conductive substrate having a thickness of 1˜1.5 μm, resulting from depositing an aluminum product 100 μm thick at a deposition rate of 1.6 m/min while supplying vapor in a vacuum at 70° C., was used.
Comparative Example 2
Use of Metal Foil 50 μm Thick
[0033] A horizontal thermoelectric tape was manufactured in the same manner as in Example 1, with the exception that aluminum 50 μm thick was used as the metal foil.
TEST EXAMPLES
Test Example 1
Measurement of Heat Conductivity of Example 1 and Comparative Example 1
[0034] Measurement of heat conductivity of Example 1 using the non-deposited metal foil comprising aluminum as the conductive substrate and Comparative Example 1 using the deposited conductive substrate was performed by the external agency (KAIST (Korea Advanced Institute of Science and Technology)). This measurement was carried out using a laser flash method. Also, a measurement instrument was LFA available from NETZSCH. The results are shown in Table 1 below.
[0000]
TABLE 1
Heat Conductivity (W/mK)
Ex. 1
100
Comp. Ex. 1
0.7
[0035] As is apparent from Table 1, in Comparative Example 1 wherein the horizontal thermoelectric tape was manufactured using the conductive substrate obtained by performing a deposition process, heat conductivity was much lower than in Example 1 without performing a deposition process. Hence, the use of the non-deposited conductive substrate as in Example 1 considerably increases heat conductivity compared to when using the deposited conductive substrate as in Comparative Example 1.
Test Example 2
Measurement of Heat Conductivity Depending on the Type of Heat Dissipation Powder
[0036] Measurement of heat conductivity of Example 1 using a graphite filler as the heat dissipation powder and Example 2 using alumina was performed. This measurement was carried out by the Center for Instrumental Analysis in Ajou University, Korea, and the rest of experiments were performed in the same manner as in Test Example 1. The results are shown in Table 2 below.
[0000]
TABLE 2
Heat Conductivity (W/mK)
Adhesion (gf/25 mm)
Ex. 1
100
1600~1700
Ex. 2
79
1400~1500
[0037] As is apparent from Table 2, Example 1 using the graphite filler as the heat dissipation powder exhibited higher heat conductivity than Example 2 using alumina. Furthermore, Example 1 using the graphite filler manifested superior adhesion to Example 2 using alumina.
Test Example 3
Measurement of Heat Conductivity and Adhesion Depending on the Amount of Graphite Filler
[0038] Changes in heat conductivity were measured depending on changes in the amount of graphite filler in Examples 1, 3 and 4. This measurement was carried out in the same manner as in Test Example 1. The results are shown in Table 3 below.
[0000]
TABLE 3
Heat Conductivity (W/mK)
Adhesion (gf/25 mm)
Ex. 1
100
1600~1700
Ex. 2
88
1700~1800
Ex. 3
11
800~900
[0039] As is apparent from Table 3, compared to Example 1, Example 3 exhibited higher adhesion but lower heat conductivity, and heat conductivity was improved but adhesion was decreased in Example 4. Therefore, Example 1 is regarded as the most preferable because both heat conductivity and adhesion are superior.
Test Example 4
Measurement of Heat Conductivity Depending on Changes in Thickness of Metal Foil
[0040] Heat conductivity was measured in the same manner as in Test Example 1 using the metal foils comprising aluminum 100 μm thick in Example 1 and aluminum 50 μm thick in Comparative Example 2. The results are shown in Table 4 below.
[0000]
TABLE 4
Heat Conductivity (W/mK)
Ex. 1
100
Comp. Ex. 2
58.836
[0041] As is apparent from Table 4, heat conductivity was much lower in Comparative Example 2 at a thickness of 50 μm than in Example 1.
Test Example 5
Shielding of Electromagnetic Waves
[0042] The effect of Example 1 on shielding electromagnetic waves was measured, wherein, in Example 1, the non-deposited metal foil comprising aluminum was used as the conductive substrate, and the amount of the graphite filler serving as the heat dissipation powder was 11.1 parts by weight based on the acrylic adhesive. This measurement was carried out by EMC (Electromagnetic Capability) Research Institute in Korea according to electromagnetic wave shielding standards [KS C 0304]. As measurement instruments, a Network Spectrum Impedance Analyzer (brand name: 4396B, available from Agilent, measurement range: 0.1 kHz˜1.8 GHz) and Shielding Effectiveness test Fixture (brand name: EM-2107A, available from Electo-Metrics Co. Ltd., measurement range: 30˜1500 MHz) were used. The results are shown in FIG. 2 .
[0043] FIG. 2 illustrates the electromagnetic wave shielding performance of Example 1 approximating to 70 dB.
[0044] Although the preferred embodiments of the present invention have been disclosed 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. | The present invention relates to a horizontal thermoelectric tape and a method for manufacturing same, and more particularly, to a horizontal thermoelectric tape for an effective blocking of an electromagnetic wave and an excellent heat dissipation effect. The horizontal thermoelectric tape of the present invention unifies the double layer structure of an adhesion layer and a heat dissipation layer, more effectively achieving the heat dissipation effect, and simplifying the manufacturing process thereof, and by using a non-evaporated metal foil as a conductive base material, enables a horizontal thermoelectric tape having an excellent heat conductivity, and using a conductive base material not containing impurities. | 2 |
TECHNICAL FIELD
The present invention concerns a method and apparatus for producing fibre yarn by first extruding a fibre suspension through a nozzle, removing excess water, and finally, by drying the yarn.
Especially an embodiment of the invention concerns a method and apparatus for dewatering the yarn and for twisting the yarn from extruded suspension to dried yarn.
BACKGROUND
Many different types of yarns made of natural fibers are known in the art. One well known example is paper yarn, which is traditionally manufactured from paper sheets. The first and only industrial method was developed in the late 19th century in Germany. It has been refined over time but the basic principle has remained the same and it is still in use today. Typically, paper manufactured from chemical, mechanical or chemi-mechanical pulp is slit to strips (width typically from 5 to 40 mm), which are twisted to thread. Said thread may be subjected to dyeing and finishing. The product (paper yarn) has limited applications because of deficiencies in its properties, such as limited strength, unsuitable thickness, layered or folded structure, and further, the manufacturing method is inefficient.
Cotton is very widely used as raw material in the manufacture of yarns and ropes. However, the cultivation of cotton requires significant water resources and it is widely carried out in regions where there is shortage of water and food. When available water is used for the irrigation of cotton fields, the situation with regard to food supply becomes worse. Thus the use of cotton does not support sustainable development, and there is a need for alternative sources of fiber, suitable for replacing cotton at least partly.
Cotton farming covers 5% of the world's farming area but it uses 11% of all agrochemicals. Intensive farming of cotton has caused pollution to the waters, wear of the soil and it has changed the animal population. In the future highly pollutant cotton can be replaced by cellulose based materials. There are already alternatives to cotton. Rayon is a material produced from cellulose fibers but it still requires heavy chemical treatments.
Methods for producing fibre yarn and other products from cellulosic materials are described in documents JP 4004501 B, JP 10018123, JP 2004339650, JP 4839973, EP 1493859, CN 102912622, CN 101724931, WO 2009028919 and DE 19544097. The methods described usually include chemical treatment of cellulose before or during manufacture of the product.
SUMMARY OF INVENTION
Production of yarn directly from fibres, such as pulp fibres, without a dissolution process or disintegration of the fibres to nanofibres would increase the efficiency and ecofriendliness of the yarn manufacturing process. It would also decrease the raw material cost significantly. Currently there is no industrial scale fibre yarn manufacturing process available for producing fibre yarn from said fibres. Fibre yarn products are produced of cotton yarn, different viscose process yarns etc. Currently there are many attempts to produce yarn from NFC.
For the above reasons, it would be beneficial to provide a method and apparatus for producing yarn directly from cellulose fibres in a manner that is commercially exploitable in industrial scale.
In a first aspect, the invention relates to a method/apparatus for taking advantage of new material by forming it mechanically into a yarn and enabling of producing environmentally friendly material which can substitute cotton and rayon.
Generally speaking the object of the invention is achieved by a novel method and apparatus as defined by the claims.
One embodiment of the invention provides a device and method that can produce cellulose based yarn continuously.
According to other aspects and embodiments of the present invention, the invention provides a yarn product that is cheaper than comparative product made of cotton.
According to one further aspect of the invention, the invention provides new use of wood and other vegetable fibres.
An embodiment of the invention is based on feeding pulp fibre suspension, such as pulp fibre suspension, from a nozzle on a first wire sieve, transporting the suspension on the first sieve to a nip formed by the first and a second sieve having a machine travel direction different from that of the first sieve for twisting and rotating the yarn to be formed between the wire sieves.
According to one embodiment, the relative machine travel directions of the at least two sieves is adjustable.
According to one embodiment, the gap between the at least two wire sieves narrows in the machine travel direction.
According to one embodiment of the invention, the gap between the at least two wires is adjustable.
According to one embodiment of the invention, at least one vacuum suction box is arranged on opposite side of at least one of the wires in relation of the wire gap.
According to one embodiment of the invention, the apparatus is equipped with at least one heating element for drying and treating the yarn to be manufactured.
The various embodiments of the invention provide essential benefits.
New method described herein for producing cellulose based yarn is cleaner to the environment compared to, for example, use of cotton and it can use harvesting surplus of wood and other cellulosic plant material. Finland's harvesting surplus of cellulosic material alone could replace 20% of the world's cotton demand. This device enables industrial scale fibre yarn production using technologies currently available in pulp and paper industry. The invention provides a possibility to create new field of industry and open totally new uses to northern wood fibres.
By the method and apparatus of the invention a fibre yarn can be made of pulp mass that need not be excessively chemically or mechanically processed. The fibre yarn can be used to replace yarn made of other materials. Further, the yarn can be used in new applications utilizing characteristic properties of the fibre yarn such as twistability. The fibre yarns can be recycled several times just like paper or board. The fibre material of the fibre yarn can be sourced from several sources. Wood fibre is suitable but also fibre materials used for manufacture of paper or board can be used as raw materials. The twisting to the yarn inherent for the inventive method increases the strength and elasticity of the yarn as it increases contacts between the fibres in the yarn, i.e. cross linking.
Other objects and features of the invention will become apparent from the following detailed description considered in conjunction with the accompanying drawings. It is to be understood, however, that the drawings are intended solely for purposes of illustration and not as a definition of the limits of the invention, for which reference should be made to the appended claims.
DESCRIPTION OF DRAWINGS
FIG. 1 is a schematic side view of one embodiment of the invention.
FIG. 2 is a schematic cross section of a nozzle that can be utilized for realizing the invention.
FIG. 3 is a schematic perspective view of one embodiment of the invention.
DESCRIPTION OF EMBODIMENTS
Definitions
Machine travel direction is the direction the sieve wires over their operating zone. Return travel direction is the direction on which the sieve wire loop runs on return side.
Operating zone of the wire sieve is the part of the sieve wire loop on which the yarn to be manufactured travels when it is processed.
Centerline of the wire is the centerline of that part of the wire loop on which the yarn to be manufactured travels when it is processed.
Pulp is considered to be mechanical, chemi-mechanical or chemical pulp mass wherein fibres have not been dissolved or disintegrated to nanofibres.
Starting point for this invention is a new method for the manufacture of fibrous yarn for connecting cellulose fibers to solid material. The method is disclosed in WO 2013/034814, which is included herein as reference. The main application for the material was the producing of the yarn by connecting fibers continuously together.
Main functions of this device are dewatering and forming of the cellulose yarn. Based on experiences from manual laboratory scale manufacturing moisture and excess water should be compressed out of the yarn while the yarn is simultaneously twisted to achieve the final form and to maintain the round cross section of the yarn during pressing.
According to the invention the pulp fibre suspension, such as pulp fibre suspension, is extruded between two angled wire sieves and the compression of wire sieves dewater the yarn and angular force element rotates and twists the yarn and the yarn will achieve its final form. The final result would resemble ordinary cotton yarn.
The proper parameters for producing the yarn such as speed, pressure and rotating angle affect to the quality and properties of the yarn. Other significant parameters include the angle of the nozzle, the speed difference between the respective speeds of the sieve and the fiber suspension 13 , which speed difference results in the stretching of the yarn, as well as speed difference between the respective speeds of formation part and drying part.
The embodiment in FIG. 1 comprises a first, lower sieve wire 1 arranged to run in a loop over guide rolls 2 . On the loop is formed a straight part between first guide roll 3 and second guide roll 4 . A second wire sieve 5 is arranged to run on a loop against the straight part of the first wire sieve 1 so that a gap 6 is formed between the wire sieves 1 , 5 . The gap between the two wire sieves 1 , 5 is arranged to narrow in the machine travel direction by guiding the second wire sieve 5 by third and fourth guide roll. This provides a narrowing pressurized gap for removing water from the pulp fibre suspension. The wire sieves 1 , 5 form a narrowing nip that is positioned to begin, in the machine travel direction, after the first guide roll 3 of the first wire sieve 1 . The first guide roll 7 of the second wire sieve 5 is positioned downstream of the first guide roll 3 of the first wire sieve 1 so that that an open space is formed on the first wire sieve 1 on the distance between the first guide roll 3 of the first wire sieve 1 and the first guide roll 7 of the second wire sieve 5 . The operation zone of the formed between the first and second guide rolls 3 , 4 of the second wire sieve 1 .
A nozzle 9 is positioned at the beginning of the operation zone of the apparatus over the open space of the first wire sieve 1 for feeding a pulp fibre suspension 13 on the first wire sieve 1 . On the opposite end of the operation zone is winder roll 11 or corresponding winding apparatus for collecting the manufactured yarn. The second guide roll 8 of the second wire sieve 5 and the second guide roll 4 of the first wire sieve 1 are spaced apart so that open space is formed on the first wire sieve 1 between these guide rolls 4 , 8 . Over this space optional heaters 12 can be placed. Suitable heaters are infrared heaters, hot air dryers or other known dryers or heaters used for example in paper, pulp and board industry. A suction box 14 for removing water and moisture from the yarn through the wire sieve can be placed on opposite side of each wire sieve 1 , 5 in relation to the yarn to be formed. In this example one suction box 14 is placed under the first wire sieve. The wire sieves 1 , 5 and winder roll are rotated by driven guide rolls, for example by means of electric motors or corresponding actuatiors.
Yarn is manufactured by the above described apparatus by feeding pulp fibre suspension over the first wire sieve 1 so that the running wire sieve 1 transfers the suspension to the nip of first and second wire sieve 1 , 5 . In the gap the yarn to be formed is twisted and rotated and pressed against the surfaces of the wire sieves 1 , 5 . This action removes water effectively and forms a good quality yarn.
One embodiment of a nozzle suitable for implementing the invention is shown in FIG. 2 , depicting a cross-section picture of a nozzle 9 . In this embodiment a circular nozzle is shown. The fiber suspension 13 is fed through the inner die or orifice 17 and if salt or other chemicals 15 are used for crosslinking, they may be fed through outer die or orifice 16 . Other cross-section geometries besides circular may as well be used, such as elliptical or rectangular. When the fibre suspension is pushed through the nozzle it has a velocity and narrow to a circular thin line 18 of fibre suspension. The diameter of the suspension line is defined by exit speed of the suspension 13 and speed of the first wire sieve 1 on which the suspension is fed.
Moist yarn obtained from the nozzle 9 initially contains water typically from 30 to 99.5% w/w. In the dewatering step the solid content of the yarn may be adjusted to desired level until all free water is removed.
The nozzle 9 forms a jet causing the gel formation. The nozzle is designed so that the flow accelerates and orients the fibres inside the nozzle. The crosslinking fluid merges with the fibre suspension outside the nozzle and the gel is formed. To maintain the round shape of the yarn in the wire section the yarn has to be twisted and rotated during the dewatering. This is done by tilting one of the wire sieves so that there is an angle difference in the wire machine direction alignment. Dewatering speed is adjusted by changing the wire gap 6 in machine direction and by vacuums Jet to wire speed difference changes the tension and stretches the yarn. Wire tension and wire gap causes also pressing of the preformed yarn to the wires.
FIG. 3 shows one embodiment of the apparatus according to the invention. It must be noted that parts and designs not shown in FIG. 1 but shown in FIG. 3 should be considered to be present in both embodiments when functionally needed as some of the part s are shown only in one figure for clarity. In here, the first wire sieve 1 is guided by three guide rolls. These rolls are mounted on a fixed (lower) frame part 19 . Second wire sieve 5 is mounted through its guide rolls to a movable (upper) frame part 20 that is movably mounted on the fixed frame part. An actuator 21 is used for adjusting the relative position of the movable frame part 20 and the fixed frame part 19 . This allows for adjusting the relative positions of the wire sieves 1 , 5 .
The method and apparatus is most suitable for producing yarns using the teachings of WO 2013/034814 that discloses a method for producing cellulose based yarn. The results from earlier experiments show that material properties of this new type of cellulose yarn are promising and good quality yarn has already been made. Previous experiments are made in laboratory scale and produced yarns have not been long enough for making e.g. fabric out of them. This problem can be solved by means of the invention.
Initial shape of the yarn is achieved through fast suspension crosslinking right after the nozzle 9 before the suspension hits the wire. In the nozzle rheology modifiers prevent clogging and the fibres are oriented with the flow. Different compounds are pumped through the nozzle with synchronized speeds and as they get mixed, the crosslinking prevents further mixing and initial dewatering with gravity.
Wet gel yarn 18 is extruded directly to the first wire sieve 1 , which conveys the material between first and second wire sieves 1 , 5 . When the preformed yarn encounters the second, in here upper, wire sieve 5 , water begins to be pressed out of it. The diameter of yarn decreases when it moves along between the wire sieves 1 , 5 . Wire sieves 1 , 5 are aligned so that the gap 6 between them decreases when approaching the output point and an angle difference in machine travel direction (X-Y) direction between the centerlines of the wire sieves 1 , 5 rotates the yarn while pressing.
All free water is removed by pressing and twisting the yarn between the wire sieves 1 , 5 . At this point the strength of the yarn is sufficient for reeling and the final dewatering takes place there. Also further drying of the yarn may be included to this device as described in narration of FIG. 1 .
Angular adjusting of the wires is implemented by two-pieced frame 19 , 20 . Fixed (lower) frame part 19 is solid and movable (upper) frame part 20 can be rotated as depicted by an arrow in FIG. 3 . Movable frame part 20 rotates along two conductors and it is lockable. Conductors permit slight movements also in horizontal plane. It is clear that a person skilled in the art can design various options for implementing this relative movement.
Frame of the device is designed to be easy to adjust and maintain.
The frame of the device is required to have high stiffness because rolls are attached only from one end and they must stay well aligned to get the yarn to uniform quality. Adding features and modifying the placement of the rolls for possible upcoming needs should be easy. It is clear that construction of the frame is not limited to the example shown.
The speeds of the wire sieves 1 , 5 are preferably accurately adjustable to get the operating speed synchronized with the pump that is feeding the material through the nozzle 9 . The operation of wire sieves can be accomplished individually with two PC controlled AC servo motors. The velocities can be automatically synchronized to each other by giving the amount of deviation in angularity of wires.
A fully functional and highly adjustable device for dewatering and forming cellulose yarn can be designed and manufactured according to the invention.
Main production parameters that effect each parameter on the form of yarn are wire sieve speed, rotating angle (angle between the wire sieves) and space between the upper (second) and the lower (first) wire. By changing the wire sieve angle in X-Y plane the force rotating the yarn at horizontal plane is changed. Gap between the wire sieves affect the compression pressure and it can also change the yarn rotation by changing friction force.
In a fully operating manufacturing facility it would be foreseeable to arrange a plurality of parallel nozzles to produce yarn on several production lines simultaneously. After the production stage described above with reference to FIGS. 1 to 3 the simultaneously produced plurality of yarns may be wound together to form one or several thick yarn(s).
Such a thick yarn consisting of said individual yarn may then be wound to a roll with or without a supplementary treatment stage of applying suitable chemicals for a particular desired effect.
Rough adjusting for these parameters can be based on results of visual inspection of the yarn. The main goal of the invention is to produce yarn continuously. The specific properties of yarn (constant diameter, tensile strength) can be adjusted by changing operating parameters. The results of the preliminary tests run on the invention were promising and established solid basis for future research.
The purpose of the invention is to provide a device to continuously produce yarn directly from a fibre suspension, preferably pulp fibre suspension. The way of turning fibre suspension into a yarn is completely new.
The device can be easily adjusted to manufacturing needs. The apparatus according to the invention can produce cellulose yarn continuously at very high speeds. Even higher speeds than 10 m/s are possible but then at least motors and drive pulleys needs to be dimensioned and chosen accordingly.
It can be contemplated that the angle and distance of the wires could be accurately adjustable by a computer while the process is ongoing for producing even longer and better shaped yarn. Further, the speed of the wire sieves may be same or different in relation to each other. Speed differences may be utilized for affecting the surface structure and twisting of the yarn, for example.
The invention utilizes preferably liquid penetrable wires, felts or belts as transfer and pressing elements. However, rubber or plastic bands or similar non-penetrable bands might also be used if water removal from the gap between the transfer and pressing elements is arranged, for example by suction. One alternative is use penetrable/non-penetrable pair of transfer and pressing elements.
With similar treatments as used with cotton yarn, cellulose yarn can reach comparable properties to cotton and can be utilized in fabrics. Raw cellulose material costs less than cotton which makes it also economically interesting. In addition, cellulose yarn is environmentally friendly. Raw material for cellulose can be gathered for example from harvesting surplus.
Thus, while there have been shown and described and pointed out fundamental novel features of the invention as applied to a preferred embodiment thereof, it will be understood that various omissions and substitutions and changes in the form and details of the method and device may be made by those skilled in the art without departing from the spirit of the invention. For example, it is expressly intended that all combinations of those elements and/or method steps which perform substantially the same results are within the scope of the invention. Substitutions of the elements from one described embodiment to another are also fully intended and contemplated. It is also to be understood that the drawings are not necessarily drawn to scale but they are merely conceptual in nature. It is the intention, therefore, to be limited only as indicated by the scope of the claims appended. | A method and apparatus for producing fiber yarn is provided. The novel apparatus includes a first transportation and pressing element ( 1 ) and a second transportation and pressing element ( 5 ) arranged adjacent to the first transportation and pressing element ( 1 ) as well as elements for driving the transportation and pressing elements ( 1, 5 ). The first and second transportation and pressing elements ( 1, 5 ) are arranged to form a nip therebetween. The apparatus also includes a nozzle ( 9 ) for feeding fiber suspension ( 6 ), such as pulp fiber suspension, to the nip between the first and second transportation and pressing elements ( 1, 5 ). | 3 |
CROSS REFERENCE TO RELATED APPLICATIONS
This application is the US National Stage of International Application No. PCT/EP2010/063701, filed Sep. 17, 2010 and claims the benefit thereof. The International Application claims the benefits of European Patent Office application No. 09011885.2 EP filed Sep. 17, 2009. All of the applications are incorporated by reference herein in their entirety.
FIELD OF INVENTION
The invention relates to a rotor comprising at least one turbine blade and a locking device for the axial and radial locking of the turbine blade, wherein the rotor comprises a blade groove and the turbine blade comprises a turbine blade root, wherein the blade groove and the turbine blade root are designed in such a way that the turbine blade root is fitted in the blade groove.
BACKGROUND OF INVENTION
Blade fastenings are usually used for the fastening of rotor blades on a rotor of a turbomachine, especially a steam turbine. As a result of the comparatively fast rotation of the rotor, the rotor blades which are arranged on the rotor are exposed to high centrifugal forces. The turbine blade root of the turbine blades must therefore withstand high forces and is pushed radially outward in the blade groove. In addition to the centrifugal forces, severe vibrational loads present a further problem which can result in mechanical damage, material fatigue, corrosion and a migratory movement of the blade root inside the blade groove. For fixing the turbine blade root inside the blade groove, various solutions, such as metal wedges, spring rings or sealing pieces, are known. Metal wedges certainly create a locking of the associated blade root inside a blade groove both axially and radially, but in the case of large rotor blades it is difficult to create sufficient retaining forces with such metal wedges during rotation in the radial direction. Disk springs create only radial retaining forces and necessitate additional expenditure for locking in the axial direction of the associated blade groove. Furthermore, complex measurements are necessary for disk springs during installation. As sealing pieces, provision must always be made for two parts, the installation of which, moreover, partially necessitates the machining of the parts by hand.
SUMMARY OF INVENTION
The invention is based on the object of providing a blade fastening for a turbomachine in which a precise and fixed retention of blades in associated blade holders is ensured over a long operating period.
This object is achieved by means of a rotor comprising at least one turbine blade according to the claims.
The locking device has a clamping piece which exerts a radial force from the rotor onto the turbine blade root. The clamping piece is arranged in this case in a groove which is located in the rotor, wherein the groove itself can be like the groove in which the shear pin is arranged. The size of the clamping piece is selected in such a way that a force is created, acting in the radial direction. This means that the turbine blade is pressed against the bearing flanks of the blade groove. Up to a certain rotational frequency, a movement of the blades in the groove is therefore effectively prevented. Beyond a certain rotational frequency, the centrifugal forces are of such magnitude that a movement is prevented as a result of the abutment against the bearing flanks. However, it is almost unavoidable that the turbine blade vibrates despite root fastening. The fastening according to the invention, moreover, prevents a relative movement between the turbine blade root and the blade groove, as a result of which surface damage is reduced.
Up to this rotational frequency, an axial displacement of the turbine blade is possible. Above the certain rotational frequency, the centrifugal forces are of such magnitude that an axial displacement is avoided, since the friction forces, which act as a consequence of the centrifugal force, effectively prevent a displacement of the turbine blade in the blade groove.
The clamping piece has an upper leg and a lower leg, wherein the upper leg butts against the turbine blade root and exerts a force against the turbine blade root in the radial direction. The lower leg butts against the rotor.
The invention is distinguished by the fact that the upper leg and the lower leg basically form a V-shape and by skilful material selection a spring force is exerted, acting from the rotor upon the turbine blade root in the radial direction.
In one advantageous development the shear pin butts against the lower leg.
Advantageous developments are disclosed in the dependent claims.
The invention is based on the idea that in a blade groove both radial and axial locking can be arranged. The shear pin is arranged in a corresponding hole in the turbine blade root and advantageously butts against an edge on the rotor. As a result, an axial movement of the turbine blade root is not possible. If a shear pin is arranged both on the leading edge and on the trailing edge of the turbine blade root in each case, then an axial displacement of the turbine blade root is effectively prevented both in the one direction and in the other direction.
The shear pin in this case is installed in a groove which is arranged in the rotor. The installation of the shear pin is carried out after the turbine blade has been installed in the rotor in the corresponding blade groove.
In order to avoid an unwanted loosening of the clamping piece, use is made of a locking element which is designed for locking the clamping piece. To this end, the clamping piece is designed as a locking plate and is arranged between the clamping piece and the rotor. By bending over the locking plate on the edge of the clamping piece, a displacement of the clamping piece is avoided, wherein at the same time the locking plate has to be arranged in a corresponding groove in the rotor.
BRIEF DESCRIPTION OF THE DRAWINGS
An exemplary embodiment of the solution according to the invention is subsequently explained in more detail with reference to the attached schematic drawings.
In the drawings:
FIG. 1 shows a side view of a rotor with a turbine blade in the installed state;
FIG. 2 shows a cross-sectional view of a part of a rotor with installed turbine blade;
FIG. 3 shows an enlarged view of a detail from FIG. 2 ;
FIG. 4 shows an enlarged view of a clamping piece;
FIG. 5 shows a perspective view of the clamping piece;
FIG. 6 shows a perspective view of a shear pin;
FIG. 7 shows a perspective view of a locking element.
DETAILED DESCRIPTION OF INVENTION
FIG. 1 shows a side view of a part of a rotor 1 with an installed turbine blade 2 . The turbine blade 2 has a turbine blade root 3 which is fitted into a corresponding blade groove 4 . The turbine blade 2 is inserted into the blade groove 4 in the axial direction 5 . The blade groove 4 is designed as a fir-tree blade groove and comprises a plurality of bearing flanks 6 .
The turbine blade 2 is locked in the blade groove 4 both in the axial direction 5 and in the radial direction 29 . The radial direction 29 basically corresponds to the longitudinal orientation of the turbine blade 2 and the axial direction 5 basically corresponds to the rotational axis, which is not shown in more detail in FIG. 1 .
For locking the turbine blade 2 , a locking device 7 , which is arranged beneath the turbine blade root 3 , is implemented. The turbine blade root 3 is designed in this case in such a way that this is fitted into the blade groove 4 , i.e. can basically move in the axial direction 5 .
In FIG. 2 , a sectional view through a part of the rotor 1 is shown. The locking device 7 in essence comprises three components. These would be, on the one hand, a shear pin 8 , a clamping piece 9 and a locking element 10 . The locking device 7 is arranged in a corresponding groove 11 in the rotor 1 . This groove 11 is formed both on the steam inlet side 12 and on the steam exit side 13 . The installation of at least two locking devices 7 , i.e. both on the steam inlet side 12 and on the steam exit side 13 , offers the advantage that the turbine blade 2 can no longer move in the axial direction 5 . The principle of operation and also the installation of the locking device 7 are explained in more detail with reference to FIG. 3 .
The shear pin 8 is of a cylindrical design and has a length L which is less than the height 14 of the groove 11 . As a result, a problem-free insertion of the shear pin 8 into the groove 11 is possible. The shear pin 8 is introduced into a hole 15 which is located in the blade root 3 . The hole 15 and the groove 11 in this case are designed in such a way that in the installed state the shear pin 8 butts against an edge 16 in the rotor 1 . A displacement of the turbine blade root 3 in the axial direction 5 is therefore no longer possible.
A further element of the locking device 7 forms the clamping piece 9 . In FIGS. 4 and 5 , a perspective and enlarged view of the clamping piece 9 is to be seen. In essence, the clamping piece 9 is constructed with a basic body 17 , which is of a cubic design, and with an upper leg 18 and a lower leg 19 . Between the upper leg 18 and the lower leg 19 a gap 20 is formed. The dimensions of the clamping piece 9 are selected in such a way that the height 21 of the clamping piece 9 is less than the height 14 of the groove. Inserting the clamping piece 9 into the blade groove 4 is therefore possible without any problem. The dimensions are also selected in such a way that in the installed state the upper leg 18 presses a force, which is similar to a spring force, against the turbine blade root 3 . The upper leg 18 has a projection 22 for this, which is about a third of the length of the clamping piece 9 . Both the upper leg 18 and the lower leg 19 are of a wedge-like construction, i.e. the upper leg 18 and the lower leg 19 taper from the basic body 17 in the direction of the legs 18 , 19 .
FIG. 6 shows a perspective view of the shear pin 8 . A third element of the locking device 7 is the locking element 10 which is constructed as a locking plate. The locking element 10 is explained in more detail with reference to FIG. 7 . In essence, the locking element 10 is designed as a sheet metal piece of an elongated form which is completely folded over once at its tip 23 , as a result of which a projection 28 is created. In the installed state, this projection 28 lies in a corresponding locking groove 24 . As shown in FIG. 3 , an axial displacement 5 of the locking element 10 is effectively avoided as a result. Furthermore, the locking element 10 has an end piece 26 which, in relation to a main piece 25 , is bent perpendicularly at the bending point 27 .
The locking device 7 is now installed as follows: First of all, the turbine blade 2 is introduced into the corresponding blade groove 4 . Next, the shear pin 8 is fitted into the corresponding hole 15 . The locking element 10 is inserted in the unbent state and at the tip 23 has a projection 28 which is arranged in a corresponding locking groove 24 . The clamping piece 9 is pushed onto the locking element 10 into the groove 11 in such a way that the shear pin 8 butts against the lower leg 19 . The possibility of the shear pin 8 falling out of the hole 15 is consequently avoided. The locking element 10 is inserted in the unbent state and at the tip 23 has a projection 28 which is arranged in a corresponding locking groove 24 . The locking element 10 is finally bent at the bending point 27 , as a result of which the possibility of the clamping piece 9 falling out of the groove 11 is effectively avoided. | A safety device for a turbine blade is provided. The safety device includes a shear pin, a clamping piece and a securing element, wherein the shear pin is arranged in a corresponding bore in the turbine blade foot and the clamping piece is designed having an upper limb and a lower limb, wherein the clamping piece exerts a radial force on the turbine blade foot for radial safeguarding. | 5 |
BACKGROUND OF THE PRESENT INVENTION
Orthogonally adjustable supports for tools and work holders have been known for many decades and have taken a variety of forms usually dependent upon the loading imposed upon the two axis support and the accuracy of adjustment, if any, required. In the widely used cross slide arrangement for supporting work holders and tools, linearly reciprocable slides are slidably mounted in a dovetail-type groove in a frame and a lead screw rotatably carried by the slide engages a stationary nut member on the relatively fixed frame for the slide. The slide in turn may form the base for a cross slide that also carries a rotatable lead screw threadedly engaging a nut member carried by the first slide.
This cross slide arrangement is suitable for heavy duty load applications and is quite capable, with the appropriate gearing and/or associated servo-mechanisms and controls, of providing accurate positioning of the work or tool supported on the cross slides. However, in many applications this degree of precision in positioning the work or tool is not required and the load supported does not require it.
A variety of linearly adjustable supports such as rod and rod clamp support structures has been suggested in the past for lighter load applications. In this general class of structures a fixed rod is provided and a rod clamp is adjustably positioned on the rod either with a deformable C-lamp or by a set screw arrangement where a set screw threadedly carried by a rod slide frictionally engages the side of the rod. In some cases an additional linearly adjustable rod passes through the clamp itself to gain an additional axis of adjustability for the support.
While the rod clamp supports have found a considerable degree of success for supporting light-load tools and workpieces, and other implements such as lighting, they have not found any great success in supporting medium or heavy-duty tooling workpieces or implements in the industrial environment because of their inability to positively lock either axially or rotationally, and also because of their inability to be adjusted in small increments. These rod clamp support assemblies rely primarily on friction to achieve locking, and hence experience a degradation in performance under higher loads, both linearly and rotationally.
One prior solution to the problem of providing adequate support in intermediate load applications utilizes a square threaded rod with a support member slidably positioned on the rod and located in position by opposed threaded fasteners on the opposite sides of the support member. This square rod and sliding support design, however, has not achieved any significant commercial success because of its inability to accurately locate the block on the rod and to positively lock the fasteners with respect to the square rod.
While the square rod support is satisfactory for some applications, it does not permit adequate clamping of the block on the rod because the block only clamps the rod on two sides, and this results in rod play in a plane transverse to the clamping direction.
A still further disadvantage in the square rod support is that substantial portions of the thread must be cut away, or never formed, to achieve the square configuration and this reduces axial rod strength. Also, the square rod support requires a large support block for a given rod cross-sectional area because of the square configuration of the bores therein.
It is the primary object of the present invention to ameliorate the above problems noted in multiple axis supports for intermediate load tools, workpieces and other implements.
SUMMARY OF THE PRESENT INVENTION
According to the present invention, support is provided for tools, workpieces and other implements that includes a plurality of angularly related hexagonal threaded rods and an interconnecting support block that provides multiple axis linear adjustability and a wide range of rotational adjustability about each axis with improved rod clamping. Toward this end, the present multiple axis support block has rod receiving transverse hexagonal bores extending completely therethrough. A pair of lock nuts are threaded on each rod and abut the sides of the block to axially locate the block with respect to each rod.
This construction provides improved rod clamping and increased rotational adjustability. Toward these ends and according to the present invention a first hexagonal threaded rod is carried by a fixed base and slidably receives the support block through one of the transverse hexagonal bores therein that are slightly larger and complementary to the threaded rods. The block is box-like in configuration and it has two slots, each running transversely through one bore and longitudinally into the other bore. These slots provide resiliency for the block, which is constructed of a low-carbon steel, that assists in performing two functions. Firstly, the block resiliency assists in tensioning the lock nuts in position, and secondly, it enables the block to clamp around the threaded support rods. An important aspect of the present invention is that during this clamping action around the hexagonal rods, the block clamps on four of the six hexagonal surfaces of each rod eliminating rod tilting in the block bores in any longitudinal plane extending through the rod. This is in distinction to square rod clamping blocks that are incapable of eliminating play between the rod and the block in a longitudinal plane extending through the rod in a direction transverse to the clamping force.
The second hexagonal threaded rod is slidably received in the other hexagonal bore in the block and has a fixture or bracket on the end thereof to which the tool, workpiece or implement may be attached. The block is axially adjusted along the first rod and with respect to the second rod by the two lock nuts threaded on each rod that are adapted to engage and abut against opposite sides of the support block. The block is moved axially on each rod by loosening and backing off one of the lock nuts. Thereafter the block is slid down the rod into engagement with the previously located lock nut and the other lock nut is threaded down against the opposite side of the block, positively locating the block in an adjusted position along the rod.
The hexagonal configuration of the threaded support rods provides greatly increased thread strength over the square threaded rod design because the combined or total arcuate length of thread per revolution for a given pitch circle diameter is far greater in the hexagonal rod. A further advantage in the hexagonal threaded rod design is that it permits a smaller block for a given rod cross-sectional area because the transverse bores in the block may be positioned somewhat close together.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of a portion of a conveyor line having two linearly and rotationally adjustable supports according to the present invention;
FIG. 2 is an exploded perspective of one of the linearly and rotationally adjustable supports illustrated in FIG. 1 according to the present invention;
FIG. 3 is a partly fragmentary cross-section taken generally along line 3--3 of FIG. 1 illustrating one of the support blocks;
FIG. 4 is an enlarged cross-section taken generally along line 4--4 of FIG. 3 illustrating the clamping action of one of the hexagonal rods; and
FIG. 5 is a cross-section generally similar to FIG. 3 with a round threaded rod substituted for one of the hexagonal rods in the FIGS. 1 to 4 embodiment.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring to the drawings and particularly to FIGS. 1 to 4, two dual axis linearly and rotationally adjustable support assemblies 10 and 11 are illustrated, each supported on a fixed steel support plate 13 welded to horizontal side rails 15 and 16 of an industrial conveyor for a paperboard carton setup and loading machine. The support assembly 10 carries a glue gun 18 while the adjustable support assembly 11 carries and adjustably positions a plow fold bar 19 fixed to a cross-member 20 carried by the lower end of support assembly 14.
Insofar as the present invention is concerned the support assemblies 10 and 11 are identical and reference will be made to the support assembly 10 hereinafter with the understanding that it applies to the support assembly 11 as well.
As seen in FIGS. 1 and 2, the support assembly 10 includes a horizontal hexagonal threaded rod 21 that is fixed in an aperture in vertical plate 13 by opposed threaded lock nuts 22 engaging the opposite sides of the fixed plate 13.
The two axis adjustable support 10 is seen to generally include a threaded hexagonal rod 21, a generally rectangular support block 26, an adjustable hexagonal threaded support rod 27, lock nuts 29 and 30 adapted to be threaded on rod 21 and clamped against the sides of block 26, and lock nuts 35 and 36 adapted to be threaded on rod 27 and clamped against the upper and lower sides of block 26.
The lock nuts 29, 30, 35 and 36 are hexagonal in configuration and have internal threads complementing the threads on rods 21 and 27.
The block 26 is constructed of a mild steel and has a first hexagonal through-bore 42 parallel but offset from the central horizontal axis of the block 26, and a second vertical hexagonal through-bore 43 that is non-itersecting with bore 42 and parallel to but offset from the vertical central axis of block 26. It should be understood that the terms "vertical" and "horizontal" used to describe the location of the rods 21 and 27 is purely arbitrary and that they may be located in any position desired.
Block 26 has opposed top and bottom walls 45 and 46 interconnected by opposed sidewall pairs 47, 48 and 49, 50. A first slot 52 extends completely vertically across the block from sidewall 48 (in FIGS. 1 and 2), transversely across bore 42 and longitudinally into the bore 43. A second slot 54 extends completely through the block horizontally from sidewall 47, transversely across bore 43, and opens into the longitudinal side of bore 42 as seen in FIG. 3. The slots 52 and 53 provide horizontal and vertical resilience for the block 26 that enables the block to clamp on the rods 21 and 27 and also tension the lock nuts 29, 30, 35 and 36 to maintain them in position.
During assembly, lock nut 30 is threaded on rod 21 until the lock nut is in a position along the rod previously determined and thereafter the block 26 is slid onto the rod 21 and backed up with lock nut 29 until the nut is loosely in engagement with block wall 49. Thereafter, rod 29 which carries with it a suitable tool, workpiece or implement at its distal end, with lock nut 36 previously threaded thereon, is slid through hexagonal bore 43. Lock nut 35 is then threaded down rod 27 until it begins to tighten against upper block surface 45. Lock nut 29 on rod 21 is then tightened against block 26, assuring intimate contact between the lock nuts 29 and 30 and block 26. During this final tensioning or torquing of lock nut 29, block 26 compresses slightly, decreasing the width of slot 42 and clamping the six surfaces defining bore 43 against the hexagonal rod 27. As seen in FIG. 4, four of the six surfaces defining bore 43 clamp against the rod 27 totally eliminating any tilting between the rod and the block 26 in any longitudinal plane extending through the axis of rod 27.
Thereafter lock nut 35 is finally set, compressing the block and partly closing slot 54 to clamp the surfaces defining bore 42 against the rod 21 in the same manner as described above with respect to bore 43. This final torquing of lock nut 35 also axially locates block 26 on rod 27.
The block 26 can be repositioned along either of the rods 21 or 27 in a similar manner. If for example it is desired to move the glue gun horizontally closer to the side rails 15 and 16, as seen in FIG. 1, the lock nut 30 is backed away from block 26 to its new position and then block 26 is slid along rod 21 until it engages the newly positioned lock nut 30. Thereafter, lock nut 29 is threaded against the opposite side of block 26 until fully clamped. Note that while loosening the lock nuts 29 and 30 removes the clamping force on the vertical rod 27, it does not permit any axial or rotational movement of the rod 27 with respect to block 26, and hence it does not affect its position. When the lock nut 29 is reset, the block 26 again clamps rod 27. Rod 27 may be readjusted with respect to the block 26 in the same manner as described with respect to movement of the block 26 along rod 21 so that no repetition in this procedure is believed necessary.
As seen in FIG. 5, the hexagonal configuration of two bores 42 and 43 in block 26, also permits the block to be used with one or two round rods 60. The round rod 60 has an outer diameter equal to the minor outer diameter of the rods 21, 27, i.e. the width of the rods across the flat portions thereof. This of course requires that the rod 60 have a smaller pitch circle diameter and hence smaller lock nuts 61 and 62 with threads equal in size to the threads on rod 60. The use of the one or more of the round rods 60 in the present support assembly is sometimes desirable when the implement supported must have an infinite variety of angular locations with respect to block 26. The six engaging and clamping surfaces of bore 43 on rod 60 eliminate all play between the rod 60 and the block 26 in all directions without causing any significant thread damage. | A support assembly of general utility that permits linear and rotational adjustability of the article supported including several angularly related hexagonal threaded rods interconnected by support blocks having transversely disposed rod receiving bores therein. The hexagonal configuration of the rods permits the blocks to be angularly located in any of six positions with respect to each rod, and clamping lock nuts threaded on the rods compress the blocks around each rod. | 5 |
This application is a continuation-in-part of application Ser. No. 08/650,462 filed on May 20, 1996, ABN.
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to hygienic devices and in particular to bidets.
2. Description of the Prior Art
Bidets have been found to be superior to the use of toilet paper for cleansing the anal-genital area of the human body. They have also provided relief for sufferers with hemorrhoids, fissures, and similar ailments. The conventional bidet is a free standing fixture with attached plumbing that provides water and drainage. A user sits on the porcelain rim of the bidet and adjusts the flow is and temperature of water with a control knob. Body position is then readjusted to accommodate the flow of water from fixed jets within the bowl. The reason that more people do not enjoy the benefits of a bidet is largely due to the extra space and expense a free standing bidet requires. Many owners of bidets find it inconvenient to move to a unit separate from the toilet. Yet shorter hospital stays, elderly home care and the AIDS crisis have created a greater need for this kind of cleansing. A wide variety of disposable douches, enemas, and wet wipes on the market have tried to meet this need. The problem is that the manufacture and disposal of these products use up valuable resources and despoil the environment. Thus a number of bidet devices and seats have been proposed for use with an ordinary flush toilet.
A primary object of a bidet device is to apply warm water to the anal-genital area of the user of a toilet. A number of such devices are electrically heated. For example, in U.S. Pat. No. 4,622,704 to Chung (1986), a lower reservoir is adapted to receive and electrically heat cold water from a refillable upper reservoir. The heated water is then transferred through a flexible hose to a handheld nozzle with a manual or electrical pump. In U.S. Pat. No. 4,422,190 to Huang (1983), an electric control system heats water inside a jacketed toilet seat, connected to the toilet water supply source. The system comprises a power source connector, a circuit breaker, a transformer for reducing input voltage, a heating coil and a thermostat, connected by a sensor inserted in the water of the jacket. The malfunction of any of these mechanisms in a moist environment, particularly if extension cords are used, may cause temperature and electrical shock for the user. Thus number of devices, using both the hot and cold water supply, have been proposed.
Some of these devices include a hand-held nozzle with a volume control that is attached to a sink faucet with a flexible hose. Here, the volume and temperature controls are often not accessible to the toilet. Pressure build-up or disconnection from the faucet could cause leakage, and water temperature cannot be changed. Thus some devices provide their own mixing valve, connected directly to the hot and cold water supply stops. Most of these devices, including U.S. Pat. No. 4,041,553 to Sussman (1977), U.S. Pat. No. 4,807,311 to Ingels (1989), and U.S. Pat. No. 4,995,121 to Barker (1991), provide external handles for adjusting the position of nozzles inside the bowl area. Their elaborate configurations restrict directional movement and are difficult to keep clean. U.S. Pat. No. 5,025,510 to Basile (1991), stores a hand-held nozzle with a flexible conduit within a compartment of the toilet or seat. While protected from elimination materials, the nozzle head is subject to mildew and mold which readily grow in the moist environment. Self-contained hand-held bidets, such as U.S. Pat. No. 4,890,340 to Lovitt (1990), are stored in a dry sanitary place but do not provide the continuous flow of water of the seat and bidet attachments.
Another object of the bidet device is to dispense a medicine or cleanser in series with the flow of water for internal and external body treatments. In U.S. Pat. No. 4,622,704 to Chung (1986) and U.S. Pat. No. 5,097,540 to Lovitt (1992), a liquid soap is somehow added to an internal chamber of a discharge handle and dispensed with the flow of water. A pump is used to dispense the liquid while the solution is being directed to the desired body area. This process may prove to be difficult for certain users. In U.S. Pat. No. 4,130,118 to McLaughlin (1978), a discharge apparatus holds a cartridge, containing solid salts, that is dissolved with the flow of warm water. These cartridges are more expensive and limited than the over-the-counter liquids used in many applications. Also, the increased weight and size of all these handles can make them awkward to maneuver. The limited volume of their reservoirs prevents multiple or extended treatments. These reservoirs must first be emptied before new liquids are added to apply different solutions.
A further object of the bidet device is to provide a safe and sanitary nozzle for applying both internal and external body treatments. The discharge nozzles of the prior art are elongated in shape and have attached disposable tips for applying internal body treatments such as douches and enemas. The insertion of these nozzle tips may irritate the sensitive lining of a body cavity especially for those suffering from hemorrhoids or, recovering from surgery. In addition, these tips can be expensive to purchase and present a disposal waste problem. In U.S. Pat. No. 4,764,997 to Anderson (1988), external heat therapy is administered with a sitz bathe adapted for such a nozzle. The integral molded channel of the sitz bathe restricts the free range of movement of the bidet. There is also the danger of contaminants being inadvertently introduced by the user during the soaking phase. Thus, independent self administration of these body treatments is often difficult.
Another object of the bidet device is to provide greater accessibility to the general population. Bidet devices thus far have been marketed to persons with special needs and tend to be automated to increase convenience. These mechanisms have complicated and expensive control and heating mechanisms that require electricity to operate. Often these functions are performed more efficiently by less complex and commercially made components. Thus a simple, more economical method of production needs to be explored.
A further object of a bidet device is to provide convenience of use without appearing obtrusive. Special seats that have nozzles located inside the toilet bowl modify the appearance of the toilet. Their proximity to the toilet bowl make them difficult to clean, and may cause unpleasant odors. Self-contained and portable hand-held bidets are either inconveniently stored out of sight or require an obtrusive reservoir tank for attachment.
A further advantage of a bidet device is to provide related solution-rinse applications with a sink basin or a shower. The elongated nozzle heads of the cited prior art can be only used with a toilet. They are not versatile enough to provide treatments to other parts of the body with a sink or a shower. Infant bathing, hair treatments, and body washes are applications that require a round nozzle head similar to that of an ordinary hand shower.
Accordingly, several objects and advantages of the present invention are:
(a) to provide a safe, efficient and sanitary warm water delivery system.
(b) to provide a safe, reusable nozzle head for both external and internal treatments.
(c) to provide a liquid dispenser that can be quickly changed for different applications.
(d) to make the device more affordable to purchase, use and maintain.
(e) to provide convenience for the user without having an obtrusive appearance.
(f) to provide a versatile nozzle head for related applications with a sink or shower.
Further objects and advantages include adaptations of self-adjustment mechanisms, currently used in showers and garden hose nozzles to modify discharge patterns. Still further objects and advantages will become apparent from a consideration of the ensuing description and drawings.
SUMMARY OF THE INVENTION
The present invention accomplishes the above-stated objectives, as well as others, as may be determined by a fair reading and interpretation of the entire specification.
A bidet apparatus is provided including a building fixture having a water pipe carrying pressurized water; a valve connector tube having a connector tube first end and a connector tube second end; a water pipe coupling structure coupling the connector tube to the water pipe so that the water pipe and the connector tube first end are in fluid communication; a mixing valve including a water inlet structure coupled to the connector tube second end, a medication inlet structure and a squeeze bottle containing medication and coupled to the medication inlet structure through a bottle coupler structure containing a check valve oriented to obstruct liquid flow into the bottle from the mixing valve structure, an internal mixing cavity in which the medication from the bottle and the water from the water pipe are mixed to produce a liquid mixture, a mixture outlet structure including an outlet coupling structure; a flexible mixture delivery tube having a delivery tube first end and a delivery tube second end, the delivery tube first end being coupled to the mixture outlet structure by the outlet coupling structure; a nozzle structure coupled to the delivery tube second end by a nozzle coupling structure; and a water flow control mechanism.
The building fixture preferably includes a hot water pipe carrying pressurized hot water and a cold water pipe carrying pressurized cold water, and a first said valve connector tube is preferably coupled with the water pipe coupling structure to the hot water pipe and a second said valve connector tube is coupled with the water pipe coupling structure to the cold water pipe, and a first water inlet means is preferably coupled with the connector tube coupling structure to the first valve connector tube and a second water inlet structure is preferably coupled with the connector tube coupling structure to the second valve connector tube, and the mixing valve preferably includes a mechanism for altering the ratio of pressurized hot water and pressurized cold water entering the mixing cavity from the first and second valve connector tubes to adjust liquid mixture temperature.
The water pipe coupling structure preferably includes a T-shaped pipe fitting fitted into a break in the water pipe. The building fixture is preferably a sink or a toilet. The water flow control mechanism preferably includes a valve in the nozzle structure.
BRIEF DESCRIPTION OF THE DRAWINGS
Various other objects, advantages, and features of the invention will become apparent to those skilled in the art from the following discussion taken in conjunction with the following drawings, in which:
FIG. 1 is a perspective view of the preferred embodiment housed in a sink vanity (cutway) showing a heated water transporting system supplied with a mixing valve assembly.
FIG. 2 is a perspective view of the valve assembly in FIG. 1 in a portable box housing.
FIG. 3 shows a perspective detailed view of a diverter tee assembly illustrated in FIG. 1.
FIG. 4 shows a perspective detailed view of the valve and dispenser assemblies in FIG. 1.
FIG. 5 is a perspective view of an alternative embodiment showing an unheated water transporting system supplied with a three port adapted ball valve.
FIGS. 6A and 6B show plan views of adaptations of the pattern portion in FIG. 5.
FIGS. 7A and 7B show perspective views of adaptations of the edge portion in FIG. 5.
FIG. 8 shows a perspective view of the nozzle assembly adapted for a shower arm.
FIG. 9 is a perspective view of a still further embodiment of the apparatus fitted to a water pipe extending from a wall where there is no pre-existing fixture.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
As required, detailed embodiments of the present invention are disclosed herein; however, it is to be understood that the disclosed embodiments are merely exemplary of the invention which may be embodied in various forms. Therefore, specific structural and functional details disclosed herein are not to be interpreted as limiting, but merely as a basis for the claims and as a representative basis for teaching one skilled in the art to variously employ the present invention in virtually any appropriately detailed structure.
Reference is now made to the drawings, wherein like characteristics and features of the present invention shown in the various FIGURES are designated by the same reference numerals.
First Preferred Embodiment
Referring to FIG. 1, a preferred embodiment of the bidet device has a heated water transporting system generally indicated by reference numeral 20 and shown housed in a sink vanity 22 adjacent to a flush toilet 24. Transporting system 20 includes a four-port mixing valve assembly, generally indicated by reference numeral 26, centrally mounted on the internal side of a side panel 30 of vanity 22, protruding through a sized opening and externally attached to a temperature/volume control knob 28. Valve assembly 26 is internally connected to the existing hot and cold water supply stops 32 and 34, feeding sink basin 36, through the hot and cold water supply lines 38 and 40, attached to a diverter assembly 42 mounted on each stop. Supply lines 38 and 40 can be made of polyethylene tubing that has been adapted on each end for attachment with the appropriate male tube adapters. A liquid dispenser assembly generally indicated by reference numeral 44, and a discharge nozzle generally indicated by reference numeral 46 are connected to valve assembly 26 on the external side of side panel 30 through sized openings disposed above and below control knob 28. Flush toilet 24, adjacent to vanity 22, includes a water reservoir tank 48, a bowl 50 having a generally oval flat rim 52, and a generally oval seat and lid assembly 54. Rim 52 has an approximately 3.5 cm width and is similar in size and shape to the flat rim of the bowl of a free standing bidet. Seat assembly 54, mounted on the rear portion of rim 52 in the usual and customary manner, is pivotally rotated in a vertical position.
In FIG. 2, a portable boxed housing 56 contains valve assembly 26 and is mounted on a wall to the rear of toilet 24, partially under tank 48. Dispenser and nozzle assemblies 44 and 46, and control knob 28 are connected to valve assembly 26 on a front panel 58 as described on side panel 30 of vanity 22 (FIG. 1). Supply lines 38 and 40, gathered and extended through an opening in a bottom panel 60, are mounted on a floor molding 62.
In FIG. 3, diverter assembly 42 (FIG. 1), comprises a male branch diverter tee 64, having three adapted openings or ports. A lower inlet port 66 is connected to an existing water supply stop S with a male tube adapter assembly 68. Assembly 68 is comprised of a male tube adapter attached to a stainless steel tubing that has been adapted at both ends with a nut and ferrule, forming a noncompressible seal with supply stop S. An upper outlet port 70 is connected to an existing supply line L with a male tube adapter 72 and an intermediate outlet port 74 has a check valve 76 leading to the nozzle assembly 46 (FIG. 1).
In FIG. 4, four-port mixing valve assembly 26, illustrated in FIGS. 1 and 2, has three inlet ports and one outlet port. Hot and cold water inlet ports 78 and 80 are connected to the supply lines 38 and 40. An upper inlet port 82 is connected to dispenser assembly 44 with the adapted elbow nipple and check valve assemblies 84 and 86. Elbow nipple assembly 84 is comprised of two street elbows joined with a hex bushing adapter that is connected to the outlet end of check valve assembly 86 with a nipple. Adapted check valve assembly 86 comprised of its check valve having its inlet end adapted for releasible engagement with a luer lock adapted cap 88 attached to a dispenser bottle 90 of dispenser assembly 44. The check valve preferably has a cracking pressure that provides minimal resistance when liquid is dispensed by compressing bottle 90. Bottle 90 is preferably made of pliable clear plastic having graduated markings that permit visible measurement. A lower outlet port 92 of valve assembly 26 is fitted with a dual elbow assembly 94, comprised of two street elbows joined with a nipple that provides the connection with nozzle assembly 46 (FIGS. 1 and 2). Valve assembly 26 has an internal pressure balancing mechanism (not shown) showing a hot water balancing spool 96, a cold water balancing spool 98 and a temperature stop 100. A circular flange 102 fastens and supports valve assembly 26 with a screw assembly 104 in the usual and customary manner.
In FIG. 5, an alternative embodiment of the present invention has an unheated water transporting system generally indicated by reference numeral 106. In transporting system 106, a three port adapted ball valve 108 comprised of a ball valve fitted with a male branch tee has an on/off control knob 110 and is connected to diverter assembly 42 mounted between an existing toilet water supply stop 112 and an existing toilet water supply tube 114. A lower inlet port 116 of adapted ball valve 108 is connected to check valve 76 of diverter assembly 42 with an elbow assembly 118, comprised of a nipple joined with a street elbow. An upper inlet port 120 is attached to adapted check valve assembly 86. An intermediate outlet port 122 is connected to nozzle assembly 46 with a hex bushing adaptor 124. Nozzle assembly 46 is comprised of a rotatable conduit holder assembly 126, a flexible hose 128, a rigid curved molded handle 130, a volume control 132 having a partial shut off knob 134, and a nozzle head 136. Holder assembly 126 is a standard rotatable ball and socket conduit joint that demountably supports handle 130. Nozzle head 136 is threadably attached to handle 130. In FIG. 6A, nozzle head 136 is shown to have an external knurled portion 138, surrounding a recessed pattern portion 140 with an internal shrouded portion 142 having a flat edge 144. Recessed pattern 140 has a circular array of openings in FIG. 6A and a centrally located opening in FIG. 6B. Edge 144 is adapted with a brush surface in FIG. 7A and is adapted with an irregular ridged surface in FIG. 7.
In FIG. 8, heated water transporting system 20 is adapted to an existing shower arm 146 with holder assembly 126 attached to the outlet and connected to dispenser and nozzle assemblies 44 and 46 with an adapted tee 148. Adapted tee 148 has two inlet ports and one outlet port. Upper inlet port 150 is attached to holder assembly 126. Intermediate inlet port 152, adapted with a check valve assembly 86, is removably attached to cap 88 of dispenser assembly 44. Lower outlet port 154, adapted with a nipple, is attached to flexible hose 128 of nozzle assembly 46. As shown by an arcuate arrow 156, dispenser bottle 90 is rotatable from a horizontal position to a vertical position at a 90 degree angle. From the description above, a number of advantages of my bidet device supplying repeatable solution treatments become evident:
(a) The warm water delivery system of the preferred embodiment provides the user of a toilet or sink with a continuous flow of adjustable warm water without the need for complicated delivery and directional mechanisms. A tee assembly, comprised of common fittings, supplies water to the bidet assembly without interfering with the existing valve assembly of the sink or toilet. The stainless steel tubing assembly provides a rigid and water tight connection between the supply line and the existing stop at a critical point. In the preferred embodiment, a pressure-balanced mixing valve conveniently supplies water of a consistent prescribed temperature to the user of a toilet or a sink. An alternative embodiment, suitable for warm climates, supplies naturally warm water feeding the toilet tank with a three port adapted ball valve. In both embodiments, the user directs a hand-held nozzle to the desired area without having to adjust body position or operate an external handle.
(b) The nozzle head can be adapted to apply a wide variety of internal and external body treatments without the need for disposable tips or extra equipment. When held away from the surface of the skin, a wide stimulating spray provides a sitz bath-type treatment. When the edge of the shrouded portion of the nozzle head is held close to a body opening, the discharge spray is externally directed into a body cavity to provide douche and enema-type cleansing. Nozzles are easily removed for sanitization and reused.
(c) The dispenser assembly of the present invention is simple and inexpensive to use. The check valve, often used as an anti-siphon device to prevent back flow of a liquid when the control valve is closed is here used to prevent back flow of water into the dispenser bottle when the control valve is opened. This unorthodox use provides additional applications without refilling. Available over-the-counter liquids can be used instead of expensive manufactured cartridges. A number of advantages over a self-contained soap chamber are provided with an externally attached dispensing reservoir. The external reservoir can be larger than an internal reservoir and additional liquid can be stored within the valve and flexible hose cavities for extending body treatments. Visual measurements on the bottle provide more accurate dispensing of liquid. Quick disconnect fittings provide easy removal for cleaning, exchange of liquids and refilling for dispensing a variety of solutions. Because liquids are measured and added before the flow of water, the user is not forced to coordinate dispensing the liquid with directing the solution to the desired body area.
(d) The substantial use of commercially available components reduces the cost of production, replacement and modification. The cost is further reduced when duplicate fittings and valves are used. Threaded attachment makes these parts easy to replace for maintenance and modification purposes. Commercial check valves, control valves, and fittings have been tested with time and are less likely to need replacement.
(e) The appearance of the toilet sink and shower facilities are not significantly modified by the installation or use of the device. There is no restriction as to the shape of the toilet bowl or need for extra space for a reservoir tank and an electric cord. The device can be inconspicuously installed adjacent but separate from the toilet bowl. The control valve and nozzle assemblies are convenient to the user of a toilet without being unsanitary. Standard components have a variety of colors and styles that blend with bathroom decor.
(f) The nozzle assembly is flexible enough to apply related solution-rinse body treatments in conjunction with a sink or shower. The different shrouded edges of the nozzle heads and the partial strut-off knob on the bidet handle permit a variety of massage and cleansing treatments with one hand. Thus a small infant can be held with the other hand while being bathed. A handicapped person can perform basic hygienic tasks alone.
Operation--FIGS. 1, 2, 5, and 8
The manner of using the bidet to cleanse the anal-genital area of the user of a toilet is similar to that of a free-standing bidet. Namely, the user sits directly on the rim of the bowl, providing a natural gasket with the thighs, and adjusts an on-off control knob that directs a stream of water to a body area. The main differences are that the user remains on the toilet, uses the control knob to alternately receive a liquid medicine or soap and water under pressure, and directs the solution with a hand-held nozzle.
Referring now to FIG. 5, the user compresses dispenser bottle 90 inserting a measured amount of liquid into check valve assembly 86 forcing excess water to drain from the nozzle head into bowl 52. The user then opens control knob 110 of ball valve 108 and directs a solution upward towards a specific anal-genital area. By holding nozzle head 136 away from the surface of the skin, a wide stimulating spray is provided. By holding edge 144 of shrouded portion 142 against a body opening, douche and enema-type treatments can be administered. The user can then manipulate the partial strut-off knob 134 with the directing hand to control the volume without using control knob 110 on ball valve 108. When the area is thoroughly cleansed and rinsed, the user returns handle 130 to holder assembly 126 and pats the area dry with a clean cloth. Nozzle head 136 can then be sprayed with a disinfectant or removed for more thorough cleaning.
Referring now to FIGS. 1 and 2 the user preadjusts the water for temperature with control knob 28 of valve assembly 26, directing the initial surge of water into bowl 52 for anal-genital cleansing, or into sink basin 36 for hair or infant cleansing. Then the user proceeds in the manner as described in FIG. 5. With the water turned off, liquid is inserted into the control valve and the solution is applied to the body area with nozzle assembly 46.
Referring now to FIG. 8 the user of a shower utilizes the existing valve assembly to apply various hair and body treatments. The user, after horizontally attaching bottle 90 to check valve assembly 86 on intermediate inlet port 152 of adapted tee 148, rotates holder assembly 126 so that bottle 90 is in a vertical position for dispensing the liquid. Liquid is dispensed and a solution is applied in the manner described in FIGS. 1, 2 and 5.
The bidet device may still alternatively extend from a water supply pipe within a building wall W which is not fitted to any existing fixture, as shown in FIG. 9. This bidet device is otherwise like that shown in FIG. 5, and connects to a single water line running within the building wall W, although the bidet embodiment shown in FIG. 1 may be used where both hot and cold water pipes run within the wall W. If the water supply pipe or pipes do not already protrude through the wall, a T-shaped connecter C of conventional design may be installed to carry the water out of the wall W and connected to the device.
Accordingly, the reader will see that my bidet device, providing repeatable solution treatments, can be used to apply a solution-rinse application with relative simplicity and convenience. The external bottle dispenser can be quickly removed, replaced or refilled. Thus liquids can be quickly exchanged to provide various as well as extended and multiple applications. A variety of different nozzle heads with different patterns and edge portions provide single-handed hair and body treatments in a sink or shower. Thorough cleansing of the anal-genital area avoids the need for abrasive and wasteful toilet paper and wet wipes. The use of tested standard parts to replace complicated mechanisms reduces production and maintenance costs.
Although the description above contains many specifications, these should not be construed as limiting the scope of the invention but as merely providing illustrations of some of the presently preferred embodiments of this invention. For example, the nozzle assembly can have other shapes and angle adjustment features such as nozzle head which can be rotated in a ball-in-socket joint and be comprised of a number of parts instead of a single molded form. The dispensing assembly can be adapted with tees to provide a plurality of openings to receive a variety of concentrates. The dispensing assembly can be adapted for use with a sink by pumping liquid into the mixing area of a faucet assembly.
In conclusion, there may be certain variations in the size, form, organization and materials of the parts shown as well as other applications of use not realized at this time, without departing from the basic functions and effectiveness of the invention. Thus the scope of the invention should be determined by the appended claims and their legal equivalents, rather than by the examples given.
While the invention has been described, disclosed, illustrated and shown in various terms or certain embodiments or modifications which it has assumed in practice, the scope of the invention is not intended to be, nor should it be deemed to be, limited thereby and such other modifications or embodiments as may be suggested by the teachings herein are particularly reserved especially as they fall within the breadth and scope of the claims here appended. | A bidet apparatus includes a building fixture having a water pipe carrying pressurized water; a valve connector tube having a connector tube first end and a connector tube second end; a water pipe coupling structure coupling the connector tube to the water pipe so that the water pipe and the connector tube first end are in fluid communication; a mixing valve including a water inlet structure coupled to the connector tube second end, a medication inlet structure and a squeeze bottle containing medication and coupled to the medication inlet structure through a bottle coupler structure containing a check valve oriented to obstruct liquid flow into the bottle from the mixing valve structure, an internal mixing cavity in which the medication from the bottle and the water from the water pipe are mixed to produce a liquid mixture, a mixture outlet structure including an outlet coupling structure; a flexible mixture delivery tube having a delivery tube first end and a delivery tube second end, the delivery tube first end being coupled to the mixture outlet structure by the outlet coupling structure; a nozzle structure coupled to the delivery tube second end by a nozzle coupling structure; and a water flow control mechanism. | 4 |
GOVERNMENTAL INTEREST
The Government has rights in this invention pursuant to Contract No. DAAA21-86-C-0171 awarded by the Department of the Army.
The invention described herein was made in the course of, or under, a contract or subcontract thereunder with the Government and may be manufactured, used and licensed by or for the Government for Governmental purposes without the payment to us of any royalties thereon.
This application is a continuation, of application Ser. No. 07/775,407, filed Oct. 15, 1991 now abandoned.
FIELD OF USE
This invention relates to an improved method of making Alpha-HMX which is highly impact insensitive.
BACKGROUND OF THE INVENTION
HMX, which is known as 1,3,5,7-tetranitro-1,3,5,7-tetraazacyclooctane, is the most powerful non-atomic explosive in military use. However, widespread use of this explosive has been limited by its excessive cost. Although HMX was first discovered in 1941, the only known process for its manufacture is the Bachmann Process but this is limited in its industrial applicability. The latter process has only been demonstrated in batch mode, and requires large excesses of reagents.
In spite of the difficulties of production, and the resulting high price, HMX has gained wide reputation as the most powerful nitramine explosive. In fact, HMX is the undisputed benchmark for all other explosives.
HMX would be applied more widely, however, if two short comings could be overcome, viz. The price of the material, and its impact sensitivity.
The first of these problems has been eliminated. The second problem has been attempted to be solved by various formulations, and compositions, all of which sought to modify its sensitivity through the inclusion of additives, both active and inert.
HMX has four polymorphs viz. Alpha, Beta, Gamma, and Delta. Three of these are stable enough to be prepared, and isolated. Delta is the only one of the four, which is unstable enough in the explosive art to be of no significance. Only trace amounts of this polymorph have been prepared for analytical purposes. Long standing reports clearly indicate that only the Beta polymorph should be considered useful, and safe. It is useful because of its high density, and safe because of its lack of sensitivity to shock. The literature indicates that Alpha and Gamma HMX are comparable to lead azide in terms of its shock sensitivity, and therefore are dangerous.
The most recent attempts to reduce the shock sensitivity of HMX have centered upon the use of small particle size in combination with additives. In the art, Beta HMX having an average particle size of 5 microns is known as Class 5 Beta HMX.
SUMMARY OF INVENTION
It is an object of this invention to provide an improved process of making HMX which provides both high power, and extreme insensitivity, at a price which competes directly with the less expensive nitramines analog RDX.
Another object is to provide an improved process of making Alpha HMX which is less sensitive to impact than Beta HMX itself. In fact, this process which produces Alpha HMX having an insensitivity to impact from drop heights of 5 to 10 times greater than that of Beta HMX itself. With this polymorph available at reasonable cost, it is expected that it could be used as a substitute for Beta HMX in existing formulations. This would provide insensitivity to the most conventional high powered explosive known to date.
Other objects and the attendant advantages of this invention will become more evident from a reading of the following specification:
DESCRIPTION OF EMBODIMENTS
The special insensitivity of this HMX is due to several factors, each of which must be held in tight tolerance. The particle size must be kept to about 1 to about 5 micron in range, the polymorph must be alpha, and the purity must be very high. To obtain the right polymorph the amount of nitric acid used must be carefully controlled as too high or too low a dilution could cause the formation of gamma HMX. Further, the temperature of the reaction must be kept as close to room temperature as possible because if the temperature rises above 45 degrees Centigrade, the product again obtained is gamma HMX, instead of alpha HMX, the desired product. To obtain the right size, the product must be precipitated with great agitation in the manner described with a high speed mixing turbine at about 15,000 RPM. The purity of the product must be upgraded using the solid phase up-grading techniques hereinafter described. Failure to follow any and all of the steps in the procedure, may seriously compromise, if not prevent the establishment of the special property of insensitivity to this alpha HMX material.
EXAMPLE 1
Nitration of TAT with a mixture of nitric acid and phosphorous pentoxide.
250 grams, within the effective range of 200 to 300 grams, of 98% nitric acid were introduced into a 500 ml. beaker, provided with a thermometer, and a magnetic stirring bar. 70 grams of phosphorous pentoxide were then added in portions over a 30 minute period. The addition was made with stirring via the magnetic stirring bar and the rate of addition of the phosphorous pentoxide was dictated by the temperature of the reaction mixture, which was not permitted to rise above 35 degrees Centigrade. The reaction mixture was allowed to stir covered by a piece of aluminum foil until the temperature fell to room temperature. 50 grams of TAT were then added in about 4 equal portions at such a rate that the temperature was prevented from rising above 40 degrees Centigrade. The reaction mixture was allowed to fall to room temperature, and the stirring bar was removed when all signs of any exothermic action had subsided. The beaker was covered by aluminum foil and allowed to set undisturbed for 16 hours at room temperature. During this time the entire reaction mixture sets-up to a cream cheese like consistency.
The reaction mixture is discharged directly into the vortex of a room temperature water bath stirred by an L-TEC air turbine mixed, (see U.S. Pat. No. 4,424,677), specifically designed for very high speed mixing and dispersing. The water acts to brake the reaction complex, and precipitates the alpha HMX, guaranteeing the formation of extremely small particles (crystals). The solid crude alpha is filtered, and washed with as much cold water as necessary to reach a constant of 7 ph. (This water should be maintained between 10 to 35 degrees Centigrade to prevent any digestion of the size of the crystals. The filtered but damp cake is then dispersed in 6 to 8 times its mass of agitated boiling water. The total washing time should not exceed 2 minutes in order to prevent size enhancement via digestion. The washed crude HMX, which should have no odor, is then filtered hot, and rinsed with cold water. This curtails crystal digestion before being thoroughly dried. The drying may be simple air drying, or vacuum drying at a temperature near 50 degrees Centigrade.
The still crude HMX must now be up-graded in purity before use. This is accomplished by anyone of the following methods.
PART 2
METHOD A
Purification of the contaminated HMX produced above by trituration with a nitric acid/phosphorous pentoxide mixture.
100 grams of the contaminated HMX are added portion wise to 100 grams of nitric acid (about 70 ml.), within the effective range 80 to 120 grams, containing 12.5 grams, which is within effective range 10 to 14 grams, of phosphorous pentoxide. The container may be a simple beaker which may be covered with aluminum foil. The quantity of nitric acid used here may be increased (not above 130 grams) for easier mixing of the mixture. The quantity used here has been found to be given about as thick a mixture as is practical. The quantity of phosphorous pentoxide may be reduced or increased depending for the greater part upon the amount of water originally present in the nitric acid and the amount of SEX present in the sample. The quantities used here have been found to work well over a very wide range of sample purities with initial melting points as low as 230 degrees centigrade. The phosphorous pentoxide should be fully dissolved and contain no solid particles. The nitric acid may be prepared ahead of time and kept as a stock solution. The HMX must be free of DANNO (1,5-diacetyloctahydro-3-nitro-7-nitroso-1,3,5,7-tetraazocine), since contamination with this compound can cause dangerous fume-offs. The gradual addition of the HMX to the nitric acid solution is to facilitate the mixing as no exothermic action should occur. The paste is left for about 16 hours at room temperature, samples may be taken to determine completion of the reaction. Reactions have been intentionally left for several days to determine if any danger results. No decomposition or fume-offs have resulted from this even when the reactions were allowed to completely dry out. When the reaction is complete the paste is spooned out of the container and dispersed in water. The HMX is washed at the filter with water until the ph remains constant. The HMX is then boiled in 8 times its weight of water for a few minutes to remove any residual phosphoric acid. The boiling continues until any foam on top has disappeared. If sufficient water is not used this foam will persist, and more water should be used. When the foam has broken up the dried material will have a literature melting of about 282 degrees centigrade which indicates a purity of greater than 98%.
METHOD B
The quantities and methods as in Example 1 above, however, a water proof container is employed and the mixture is placed in a constant temperature bath at 40 degrees centigrade. The thickness of the paste in the container is limited so as to permit attainment of bath temperature throughout the mixture in a reasonable period of time. If necessary the mixture may be stirred mechanically. Under these conditions the upgrading time is reduced to approximately 4 hours.
METHOD C
The same quantities were used as set forth in Example 1 however, the mixture is fed through a heated screw mixer or feeder for rapid mixing and temperature equilibration. The temperature may be adjusted upwards to the 70 degree region reducing the reaction time to a matter of minutes.
RESULTS
The impact values obtained via the "ERL, Type 12 Impact Tester" using a 2 and one half kilogram mass, demonstrated values 5 to 10 times greater than normally achievable with "Class 5 Beta HMX", and kinetic energy values 10 to 20 times greater than normal, As the following actual data indicates
______________________________________DROP Initiation y = yes, n = no______________________________________100 cm drop n100 cm drop n100 cm drop n100 cm drop n100 cm drop n100 cm drop n100 cm drop n100 cm drop n100 cm drop n100 cm drop n150 cm drop n150 cm drop n150 cm drop y150 cm drop n150 cm drop n150 cm drop y150 cm drop n150 cm drop y150 cm drop n150 cm drop y______________________________________
Do to the damage being caused to the test apparatus by the large amount of kinetic energy released from such great drop heights it was decided to accept the 50% initiation value as being somewhere above 150 cm.
ANALYSIS
We have found that small crystals of Alpha HMX, which were produced by this process, have an average particle size of about 1 to about 5 microns are remarkably resistant to impact initiation. Using the standard impact test (ERL, Type 12 impact tester), the 50% initiation point was found to be greater than 150 cm. This is a tremendously higher value than Beta HMX (Class 5) which has a 50% initiation point of 35 cm when examined by the same test method. It should be noted that the 150 cm value, cited above, is also much higher than many explosives normally considered relatively insensitive such as TNT which has 61.3 cm point. See Table below.
TABLE 1______________________________________ IMPACTEXPLOSIVES 50% PT (CM)______________________________________HMX 35.0 ± 1.8RDX 39.0 ± 1.3PETN 17.1 ± 2.2TNT 61.3 ± 2.1COMP B 44.2 ± 3.4ALPHA HMX 150______________________________________
CONCLUSION
The practice of the present invention is considered to be novel. The prior art attempts to achieve high levels of insensitivity of Alpha HMX or Beta HMX have had no success. What little progress that has been made is at the price of diluting the performance of the material Beta HMX with the incorporation of foreign substances.
This invention provides extreme insensitivity of Alpha HMX without compromising purity, and does this by the unique application of the present invention to change the dangerously sensitive alpha polymorph of HMX to a highly insensitive polymorph. We maintain very tight particle distribution of Alpha HMX within about 1 to about 5 microns.
In summary, this process proceduces the most powerful but least sensitive non-atomic exlosive in existence today. The explosive is the purest HMX known, and it contains no RDX contamination.
The foregoing disclosure and drawings are merely illustrative of the principles of this invention and are not to be interpreted in a limiting sense. We wish it is to be understood that We do not desire to be limited to the exact details described because obvious modifications will occur to a person skilled in the art. | An improved process of making a highly impact insensitive form of HMX cal Alpha HMX has been accomplished. Test results of insensitive impact from drop heights of 5 to 10 times greater than Beta HMX, the conventional explosive, has been successfully achieved. This accomplishment has been achieved without the addition of any additives, and is attributed to the attainment of small particle size, whole crystals, narrow size distribution, and sample purity. | 2 |
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
[0001] This Invention was made with U.S. Government support under Contract No. DE-EE0004737 awarded by the Department of Energy. The Government has certain rights in this invention.
BACKGROUND
[0002] Workpiece processing, such as solar cell or semiconductor wafer processing, requires a plurality of steps to achieve the finished product. In some embodiments, the workpiece must be moved from a station which performs one of these steps to another station which performs a different step. In some cases, the workpiece is placed in a carrier, which holds and protects the workpiece during these transitions.
[0003] However, these carriers are often constructed such that they hold or envelop the edges of the workpieces, thereby covering at least a portion of the workpiece. As a consequence, in some cases, the workpiece typically must be removed from the carrier to be processed, adding time and complexity to the process. In those cases where processing is performed on the workpiece while in the carrier, additional steps are often required to insure that the edges, which were blocked or obscured by the carrier, receive the same treatments as the remainder of the workpiece. Again, these extra steps add time and complexity to the process. Furthermore, in some cases, the edges of the workpiece that are covered during the processing may not be treated in another process step, reducing the efficiency or performance of the workpiece.
[0004] Additionally, during workpiece processing, it is often necessary to place a mask in front or on top of the workpiece to limit the exposure of the workpiece to energy, typically in the form of ions or light. This mask must be precisely aligned to the workpiece to insure that the workpiece is properly processed. Unfortunately, this critical alignment may be compromised by various forms of errors, such as thermal expansion of the mask or other materials that are not thermally matched with regard to the coefficient of thermal expansion (CTE) during processing, misalignment of the mask to the workpiece, general tolerance stack ups, workpiece irregularities, and other issues.
[0005] Therefore, it would be beneficial if there were a carrier that could be used to hold a workpiece, such that the carrier did not block or obscure the edges of the workpiece, thereby allowing complete processing of the workpiece while in the carrier. Furthermore, it would be beneficial if this carrier facilitated the alignment of a mask to the workpiece. Still further, it would be advantageous if this carrier were able to hold a plurality of workpieces and a plurality of masks, each associated with one of the workpieces.
SUMMARY
[0006] A carrier capable of holding a plurality of workpieces is disclosed. The carrier is divided into a plurality of bounded regions, called cells, which each hold one workpiece. The carrier includes movable projections located along the sides of each cell. This carrier, in conjunction with a separate alignment apparatus, aligns each workpiece within its respective cell against several alignment pins, using a multiple step alignment process to guarantee proper positioning of the workpiece in the cell. First, the workpieces are moved toward one side of the cell. Once the workpieces have been aligned against this side, the workpieces are then moved toward an adjacent orthogonal side such that the workpieces are aligned to two sides of the cell. Once aligned, the workpiece is held in place by the projections located along each side of each cell, which press against the edges of the workpiece. These projections hold the workpiece without obscuring the edges, the top surface or the bottom surface of the workpiece that is to be processed. In addition, the alignment pins, to which the workpiece is aligned, are also used to align the associated mask, thereby guaranteeing that the mask is properly aligned to the workpiece.
[0007] The alignment apparatus includes a first set of actuators that cause the carrier to move each of the workpieces toward a side of the cell. The alignment apparatus also includes a second set of actuators, operative after the first set of actuators, which cause the carrier to align the workpieces toward a second adjacent orthogonal side of the cell. The alignment apparatus may also include another set of actuators which can be used to lift and lower the workpieces to the carrier.
BRIEF DESCRIPTION OF THE FIGURES
[0008] FIG. 1 shows a perspective view of a carrier according to one embodiment;
[0009] FIG. 2 shows an enlarged view of a mask to be used with the carrier of FIG. 1 ;
[0010] FIG. 3 shows a detail of one of the mask alignment features located on a mask that can be installed in a cell of the carrier;
[0011] FIG. 4 shows an enlarged view of one cell of the carrier with the mask removed;
[0012] FIG. 5 shows an enlarged view of the cell alignment pin engaged with the mask alignment feature;
[0013] FIG. 6 shows a workpiece after alignment;
[0014] FIG. 7 shows a workpiece in a cell prior to alignment;
[0015] FIG. 8 shows a workpiece during the alignment process;
[0016] FIG. 9 is an enlarged view of the movable projection according to one embodiment;
[0017] FIGS. 10A-C show the interaction between the actuator and the movable projection;
[0018] FIG. 11 shows an alignment apparatus that can be used with the carrier of FIG. 1 ; and
[0019] FIG. 12A-C show the alignment apparatus of FIG. 11 during various stages of execution.
DETAILED DESCRIPTION
[0020] FIG. 1 shows one embodiment of the carrier 100 . This embodiment shows 16 cells 110 , grouped as a 4×4 matrix. However, other configurations and cell quantities are within the scope of the invention. The carrier 100 includes four outer walls 120 a - d and a plurality of inner walls 125 . These outer walls and inner walls are arranged in a grid pattern, where the area between intersecting walls defines a cell 110 . The number of inner walls 125 helps determine the number of cells 110 in the carrier 100 . Of course, if only one cell 110 is required, no inner walls 125 are needed.
[0021] The upper surface of the outer walls 120 a - d and inner walls 125 , also referred to as cladding, is preferably constructed of graphite to minimize contamination caused by sputtering. The interior frame of the carrier 100 , the components within the interior frame, and any surfaces that are not exposed to ion implantation may be constructed of a different material, such as aluminum. FIG. 1 also shows a mask 130 positioned on one of the cells 110 .
[0022] FIG. 2 is an enlarged view of the mask 130 shown in FIG. 1 . The mask 130 includes shoulders 140 a - e , which rest atop the outer walls 120 a , 120 d and the inner walls 125 (see FIG. 1 ). In some embodiments, the mask 130 is a monolithic graphite machined component. Located on several of the shoulders 140 a , 140 d , 140 e are mask locating features 145 . These mask locating features 145 may be constructed of silicon carbide and pressed into corresponding holes located in the shoulders 140 a , 140 d , 140 e of the mask 130 . These mask locating features 145 are machined based on the master module layout datums in order to insure that each mask 130 accurately and repeatedly aligns to each cell 110 even during elevated heat environments.
[0023] FIG. 3 shows a bottom view of the mask 130 of FIG. 2 . This figure is enlarged so that the lower surface of shoulder 140 d can be seen. Designed into this shoulder 140 d is one or more elongated depressions 150 , or V-grooves. The bottom of a mask locating feature 145 is visible and is located within a respective elongated depression 150 or V-groove. The alignment pins (see FIG. 4 ) fit into these elongated depressions 150 and align to the mask locating features 145 . Other shoulders 140 may also have one or more elongated grooves and mask locating features.
[0024] FIG. 4 shows an enlarged view of a cell 110 without a mask 130 installed. Portions of outer walls 120 a,b and inner walls 125 a,b form the perimeter of cell 110 . Located at the bottom surface of the cell 110 within the perimeter of the cell 110 is a platen 160 . The platen 160 may be an electrostatic chuck, as is known in the art. The platen 160 may have one or more openings 165 in it, which allow a set of lift pins to extend through the platen 160 to lift the workpiece, as described in more detail below.
[0025] Along the outer edges of the platen 160 (i.e. those portions nearest to the perimeter) may be shielding 170 , which insures that the platen 160 is not exposed to the ions during implantation. This may occur if the area occupied by the workpiece is slightly smaller than the area defined by the perimeter of cell 110 . This shielding 170 may be graphite to lower the risk of contamination. Located along inner wall 125 b are two alignment pins 180 a,b . A third alignment pin 180 c is located along outer wall 120 a . These three pins 180 a - c are located on the perimeter and serve to align the workpiece within the cell 110 . These pins also serve to align the mask 130 , via the mask locating features 145 illustrated in FIGS. 2-3 that mate with these alignment pins 180 a - c . While three alignment pins 180 a - c are shown, a different number of alignment pins may be used. For example, two alignment pins may be located along outer wall 120 a.
[0026] FIG. 5 shows an enlarged view of the alignment pin 180 engaged with shoulder 140 of the mask 130 . The mask 130 is shown as transparent so the interaction between the mask 130 and the alignment pin 180 can be shown. The mask locating feature 145 is disposed within the elongated depression 150 , as described above. When the mask is engaged with the carrier 100 , the alignment pin 180 is positioned within the mask locating feature 145 .
[0027] FIG. 6 shows an enlarged view of a cell 110 with the graphite cladding removed to allow visibility into the internal components of the carrier 100 . Located under the graphite cladding are the mechanisms used to align the workpiece 10 to the alignment pins 180 a - c of the cell 110 . Located along each side of the cell 110 are one or more movable projections 190 , which operate to move the workpiece 10 when actuated. The movable projections 190 may be any suitable device, such as pegs or wheels. These movable projections 190 are each naturally biased through the use of a biasing member, such as a spring, elastic band, or the like. FIG. 6 shows two such movable projections 190 located on each side of the cell 110 . In one embodiment, movable projections 190 a,b are inwardly biased, so as to move the projections toward the interior of cell 110 . Similarly, movable projections 190 c,d are also inwardly biased. In contrast, the remaining movable projections 190 e - h are all outwardly biased, so that they move away from the cell 110 . The terms “inward” and “outward” are referenced to the interior of the cell of interest. Movable projections 190 located on opposite sides of the perimeter are biased in the opposite way. In some embodiments, the movable projections 190 located along those sides on which the alignment pins 180 are disposed are naturally outwardly biased, while the remaining movable projections 190 are naturally inwardly biased. Of course, other biasing configurations are possible.
[0028] While movable projections 190 are shown along each side of the perimeter of the cell 110 , other embodiments are possible. For example, in some embodiments, movable projections 190 are only located on those sides opposite the sides where the alignment pins 180 are disposed.
[0029] In some embodiments, such as that shown in FIG. 6 , the movable projections 190 located along the inner walls 125 , such as movable projections 190 a - d may be used for two adjacent cells 110 . In other words, movable projections 190 a - d would also serve as movable projections for an adjacent cell. In other embodiments, each cell 110 may have dedicated movable projections 190 .
[0030] In operation, as shown in FIG. 7 , to place the workpiece 10 in the carrier 100 , the movable projections 190 are all actuated so as to overcome their natural biased position. In other words, movable projections 190 a - d are outwardly biased, while movable projections 190 e - h are inwardly biased. This allows the workpiece to be placed on the platen 160 . Note that movable projections 190 a,b are outwardly biased with respect to cell 110 , but would be inwardly biased relative to an adjacent cell 110 . Thus, these movable projections can be operative in two adjacent cells 110 . In this position, the workpiece 10 is not being pressed toward the alignment pins 180 .
[0031] As seen in FIG. 8 , movable projections 190 a,b are then allowed to return to their naturally biased position, causing them to extend inside the perimeter of the cell 110 . This action pushes the workpiece 10 toward the alignment pins 180 a,b . Once the workpiece 10 contacts the alignment pins 180 a,b , its movement in this direction ceases. The natural bias of the movable projections 190 a,b holds the workpiece 10 against the alignment pins 180 a,b.
[0032] As seen in FIG. 6 , after movable projections 190 a,b have ceased movement, movable projections 190 c,d are allowed to return to their naturally biased position. This serves to push the workpiece 10 , which is already aligned to alignment pins 180 a,b toward alignment pin 180 c . Once the workpiece 10 contacts the alignment pin 180 c , its movement in this direction ceases. The natural bias of the movable projections 190 c,d hold the workpiece 10 against the alignment pin 180 c . In this way, the workpiece 10 is held in place without blocking or obscuring any portion of the workpiece 10 .
[0033] To remove the workpiece 10 from the carrier 100 , these steps may be executed in reverse order. In this case, movable projections 190 c,d are actuated to overcome their natural biased positions, and movable projections 190 g,h move the workpiece 10 away from alignment pin 180 c . Subsequently, movable projections 190 a,b are actuated to overcome their natural biased positions, and movable projections 190 e,f move the workpiece 10 away from alignment pins 180 a,b.
[0034] Although this disclosure describes a sequential operation where the workpiece 10 is first moved toward alignment pins 180 a,b , and then toward alignment pin 180 c , other embodiments are possible. For example, the workpiece 10 can be moved in both directions simultaneously. In another embodiment, the workpiece is moved toward alignment pin 180 c first, and then toward alignment pins 180 a,b.
[0035] Similarly, the process of releasing the workpiece 10 may be different. In another embodiment, movable projections 190 a - d are actuated simultaneously, so that workpiece moves away from all alignment pins 180 a - c simultaneously. In another embodiment, movable projections 190 a,b are actuated first, thereby pushing the workpiece 10 away from alignment pins 180 a,b . The movable projections 190 c,d are then actuated, moving the workpiece 10 away from alignment pin 180 c.
[0036] In other words, the movable projections 190 can be actuated in any predetermined sequence.
[0037] The movable projections 190 can be actuated in a variety of ways. FIG. 9 shows an enlarged view of one embodiment of a movable projection 190 . The movable projection 190 includes a rotatable wheel 191 , which is pivotable about an axis located near one end of projection 190 . The movable projection 190 is pivotable about a point 192 . The opposite end of the projection 190 is attachable to a biasing member 193 . The biasing member 193 causes the movable projection 190 to rotate about the point 192 . The biasing member 193 may be a compliant spring mechanism that allows for irregularly shaped workpieces 10 to be used in the carrier 100 . It also allows for expansion caused by thermal growth during processing, since the energy imparted on the workpiece 10 , such as during implantation, may be significant and may cause parts of the workpiece 10 to grow at different rates. Biasing members 193 are also independent on each movable projection 190 allowing each one to be used independently. This may reduce hertzian stresses on the edge of each workpiece 10 . Actuator 221 is the mechanical device that pushes up and down and causes movable projection 190 to pivot about point 192 . Biasing member 193 then serves as the counteracting mechanism, allowing the movable projection 190 to return to a naturally biased position after actuator 221 is retracted from the opening 194 . A spring stop that help capture the biasing member 193 may be located on the back side of biasing member 193 . In some embodiments, the biasing member 193 can push the movable projection 190 , while in other embodiments, the biasing member 193 pulls the movable projection 190 . In one position, the movable projection 190 , and specifically the wheel 191 , extends into the cell 110 . In the second position, the wheel 191 is retracted from the cell 110 . Located in the movable projection 190 is an opening 194 . This opening 194 is aligned to an aperture under the movable projection 190 , through which an actuator may extend. When the actuator extends into this opening 194 , it moves the movable projection 190 and holds it in a help position, different than its naturally biased position.
[0038] While FIG. 9 shows a wheel 191 , other configurations of the movable projection 190 are also within the scope of the disclosure. For example, the wheel 191 may be replaced with a peg or other rigid member that does not need to rotate which performs the same function. This peg or other mechanism may still be connected to the biasing member 193 . The surface of the wheel 191 , peg, or other mechanism that contacts the workpiece 10 may be flat, angled, curved, or other shapes.
[0039] FIGS. 10A-C shows a cross-sectional view of the movable projection 190 , showing the interaction between the actuator 221 and the opening 194 . As can be seen in FIG. 10A , the actuator 221 is not exactly aligned to the opening 194 when the moveable projection 190 is in its naturally biased position. The opening 194 in the movable projection 190 has a sidewall having a downward facing ramp 195 . As the actuator 221 moves upward through an aperture in the carrier 100 , it travels along this ramp 195 , causing the movable projection 190 to move away from its natural biased position, as seen in FIG. 10B . When the actuator 221 is fully extended, as shown in FIG. 10C , the movable projection 190 is in the held position.
[0040] FIG. 11 shows one possible alignment apparatus 200 . This apparatus 200 can be used to lower the workpiece 10 onto the carrier 100 , actuate the movable projections 190 in a predetermined sequence, and later, lift the workpiece from the carrier 100 .
[0041] The apparatus 200 has a number of plates, some of which are stationary and others of which are movable. The top plate 210 is stationary and provides a platform on which the carrier 100 may be disposed. This top plate 210 may have a plurality of holes through which lift pins 231 and actuators 221 may pass. In other embodiments, a portion of the top plate 210 , such as the middle portion, may be removed to allow a space where these lift pins 231 and actuators 221 may pass. The top plate 210 may also have a mechanism used to hold or secure the carrier 100 to the top plate 210 . In one embodiment, this mechanism may be a set of magnets, which are aligned to magnetic portions located on the bottom of the carrier 100 .
[0042] Positioned beneath the top plate 210 is a movable plate, known as the actuator plate 220 . The actuator plate 220 is coupled to a linear actuator 280 , which moves the actuator plate 220 up and down along the central shaft 290 . Located on the upper surface of the actuator plate 220 and extending upwardly, is a plurality of actuators 221 . These actuators 221 may be of various heights. In the case of two different heights, one set of actuators 221 a are used to actuate the movable projections 190 a,b and 190 e,f of each cell 110 (see FIG. 6 ). These actuators are of a first height. A second set of actuators 221 b are used to actuate the movable projections 190 c,d and 190 g,h of each cell 110 . These actuators 221 b are of a second height, which is greater than the first height. These actuators 221 pass through openings in the top plate 210 , as described above. Other various height actuators may be employed to facilitate moving the workpiece to specific load, unload, clamp, offset, and rotational positions. This may be performed for processing, tailoring improvements, imaging for repeatability and accuracy verification, or teaching methods for robots, for example.
[0043] Beneath the actuator plate 220 is the lift plate 230 . The top surface of the lift plate 230 has a plurality of upwardly extending lift pins 231 , which are used to lift the workpieces 10 from the carrier 100 . These lift pins 231 are located so as to contact the underside of the workpieces 10 . As described above, each of the platens 160 (located in carrier 100 ) may have openings to allow these lift pins 231 to extend into the carrier 100 and lift the workpieces 10 . This lift plate 230 is controlled by a linear actuator 281 , which allows the lift plate 230 to move vertically along the central shaft 290 . To accommodate these lift pins 231 , actuator plate 220 may have openings therein to allow the lift pins 231 to pass through.
[0044] The alignment apparatus 200 may also have a lower plate 240 , which is stationary and used for bearing and as support anchors.
[0045] In operation, as shown in FIG. 12A , the lift plate 230 is lifted toward the top plate 210 , as is the actuator plate 220 .
[0046] The lift pins 231 extend through the carrier 100 . A robot or other mechanism then loads a workpiece 10 on the set of lift pins 231 associated with each respective cell 110 . In some embodiments, there are four lift pins 231 associated with each cell 110 , although other numbers of lift pins 231 can extend through each cell.
[0047] The lift plate 230 then descends as controlled by linear actuator 281 , which allows the workpieces 10 to sit in their respective cells 110 , as shown in FIG. 12B . In this view, the workpieces 10 are no longer visible, as they are sitting within the carrier 100 . At this time, the actuator plate 220 is still positioned up toward the top plate 210 , such that the actuators 221 a,b are engaged with openings 194 in the movable projections 190 , as shown in FIG. 10C .
[0048] As the actuator plate 220 is moved downward, as seen in FIG. 12C , away from the top plate 210 and the carrier 100 , the first set of actuators 221 a, which contain shorter pins, disengages from the movable projections 190 a,b and 190 e,f (see FIGS. 6-8 ) first. This allows these projections 190 a,b and 190 e,f to move to their natural biased positions and moves the workpiece 10 against the alignment pins 180 a,b , as shown in FIG. 8 .
[0049] As the actuator plate 220 continues to move away from the top plate 210 , as seen in FIG. 12C , the second set of actuators 221 b , which are longer, disengages from the remaining movable projections 190 c,d and 190 g,h. This allows the remaining movable projections 190 c,d and 190 g,h to return to their naturally biased positions. This movement causes the workpiece 10 to be moved against the alignment pin 180 c (see FIG. 6 ). The time between the disengagement of the first set of actuators 221 a and the second set of actuators 221 b is determined based on the difference in height between these two sets of actuators 221 a,b and the speed at which the actuator plate 220 moves (assuming that the actuator plate 220 moves at a constant speed). Of course, this time can be adjusted by using a non-linear speed profile for the actuator plate 220 . This can be achieved by controlling the linear actuator 280 to slow the speed of the actuator plate 220 after the first set of actuators 221 a have disengaged.
[0050] Performing two direction alignment in two separate steps may, in some embodiments, reduce workpiece breakage or workpiece jamming or misalignment in the cell. In other embodiments, the alignment in both directions is performed simultaneously.
[0051] In another embodiment, the actuator plate 220 can be implemented as two separate plates, where one plate has the first set of actuators 221 a and the second plate has the second set of actuators 221 b . These plates may be independently controlled by separate linear actuators, so that the actuators 221 can be moved in any desired sequence. This configuration allows different engagement and disengagement sequences.
[0052] As mentioned above, other embodiments are possible. For example, all actuators 221 may be the same height, since the alignment of the workpiece 10 occurs in both directions simultaneously.
[0053] Once the actuator plate 220 and lift plate 230 have been lowered, the workpieces are all aligned and clamped via the movable projections 190 (see FIG. 9 ) to their respective cells. Once the workpieces are clamped, the carrier 100 may be processed. The processing of the workpieces may include ion implantation, deposition, etching, or other processing steps, as are well known in the art. In one embodiment, masks, such as those shown in FIGS. 1-3 , are placed on each respective cell prior to the processing of the workpieces. This may be done using a robotic mechanism. In another embodiment, no mask is used during the processing. The carrier 100 may be moved to a different location for processing, such as ion implantation, than where the workpiece alignment occurs. This processing may involve flipping or rotating the carrier 100 . The embodiments disclosed herein may retain the workpieces 10 in the cells 110 during this moving, flipping, rotating, or other motion.
[0054] The present disclosure is not to be limited in scope by the specific embodiments described herein. Indeed, other various embodiments of and modifications to the present disclosure, in addition to those described herein, will be apparent to those of ordinary skill in the art from the foregoing description and accompanying drawings. Thus, such other embodiments and modifications are intended to fall within the scope of the present disclosure. Furthermore, although the present disclosure has been described herein in the context of a particular implementation in a particular environment for a particular purpose, those of ordinary skill in the art will recognize that its usefulness is not limited thereto and that the present disclosure may be beneficially implemented in any number of environments for any number of purposes. Accordingly, the claims set forth below should be construed in view of the full breadth and spirit of the present disclosure as described herein. | A carrier capable of holding one or more workpieces is disclosed. The carrier includes movable projections located along the sides of each cell in the carrier. This carrier, in conjunction with a separate alignment apparatus, aligns each workpiece within its respective cell against several alignment pins, using a multiple step alignment process to guarantee proper positioning of the workpiece in the cell. First, the workpieces are moved toward one side of the cell. Once the workpieces have been aligned against this side, the workpieces are then moved toward an adjacent orthogonal side such that the workpieces are aligned to two sides of the cell. Once aligned, the workpiece is held in place by the projections located along each side of each cell. In addition, the alignment pins are also used to align the associated mask, thereby guaranteeing that the mask is properly aligned to the workpiece. | 8 |
BACKGROUND
1. Field of the Invention
This invention relates generally to computer-based information systems, and, more particularly, to a computer-aided interactive system that provides a user with information about various career opportunities. The invention further relates to a method of using such an interactive computer-based system.
2. Statement of the Art
There is a long-recognized benefit to school-aged children and young adults in providing information relating to various career and occupations to enable them to direct their future academic studies toward obtaining a particular career or occupational position. It is also recognized that career and occupational information is useful to older adults who wish to pursue a new or different career from one in which they have previously been employed.
Presently, in order to investigate various careers or occupations, one must either manually search and read through numerous publications, or find and question someone working in a particular field of interest. This is true whether the person conducting the search is on the junior high, high school or college level, or is presently employed. A manual search of this type is very difficult to organize, particularly if a number of different careers are of interest to an individual, and the task is very time-consuming. Moreover, reading a periodical, for example, about a particular career lacks personal interaction and provides no means for asking pertinent questions about the particular career or occupation.
At the same time, there has been a tremendous increase in the availability and use of personal computers in the last fifteen years which has effectively put a wealth of information readily at one's fingertips. Additionally, CD-ROM technology is increasingly becoming a vital part of most personal computer systems because of its data storage capacity and quick data accessibility. CD-ROM has provided a medium for software applications that were impractical or impossible before. Complex and detailed graphic-based programs, such as games, are made increasingly possible because of CD-ROM technology. Thus, many new programs which are only available on compact disc have evolved as a result.
Because of its inherent qualities, one of the first and most notable uses of CD-ROM technology for personal computers involved encyclopedia applications. Due to its ability to store large mounts of information, several encyclopedia volumes can be stored on a single compact disc. In addition, due to its ability to quickly access information, CD-ROM technology has made it possible to include visual and audio effects that can be accessed and presented along with the encyclopedia text to enhance the computer environment for a user.
Thus, it would be advantageous to provide a computer-aided interactive means for researching career opportunities which permits the user to selectively access a compilation of information relating to one or more careers or occupations. It would further be advantageous to employ the technology of CD-ROM to facilitate such interactive researching.
SUMMARY OF THE INVENTION
In accordance with the present invention, computer-aided interactive means are provided for selectively accessing a compilation of information relating to one or more careers which is structured to facilitate self-directed and individualized searching of career and occupational opportunities. The interactive means of the present invention may be provided in any suitable computer-accessible format, including CD-ROM, and means are provided for downloading and printing career information from the system at the user's command to enable the user to memorialize the search results. The interactive means of the present invention is also structured to provide access to a single compilation of information in a variety of languages, including American Sign Language (ASL), thereby enabling its use by other than English-speaking persons.
The interactive means of the present invention comprises a computer-based system which contains a compilation of information relating to one or more careers. The information may be compiled in a database contained in a suitably structured software program. Alternatively, the information may be compiled on one or more CD-ROM discs and may be accessible by conventional means relating to CD-ROM. Alternative vehicles for accessing or providing interactive means for exploring career opportunities include on-line services, network services, direct TV, direct satellite and cable accessible resources.
The data may be compiled from various sources, including written information from, for example, government sources or public libraries. In a preferred embodiment, the information presented in the interactive means is derived from interviews of persons employed in a variety of careers. The interactive means presents to the user a means for selectively accessing the compiled information in a manner which allows the user to define his or her own research parameters. That is, the user may move through multiple levels of inquiry structured within the interactive means, and may, within a particular level of inquiry, selectively access a variety of information specifically responsive to the user's research needs.
The user initiates the interactive means through appropriate hardware structure. The user is provided with a means for selectively directing his research in a particular searchable field relating generally to careers. Thus, for example, the user may initiate his search in career opportunities by selecting from a menu of field identifiers. Examples of field identifiers may be "careers by geographical location," "careers by educational requirement," "careers by average yearly income," "careers by subject," and the like. Within any field identifier there may be a secondary, tertiary, quaternary, or further levels of sub-field identifiers to select from. For example, within the field identifier of "careers by geographical location," there may be secondary sub-field identifiers such as "careers in the Southern United States," "careers in the outdoors," "careers relating to water resources," and the like.
In a preferred embodiment, the information compiled relating to a specific career may be derived from interviews of persons employed in that career or occupation. Alternatively, live interviews may be staged using actors who are prepared to answer specific questions, the answers to which are derived from written text resources, such as government-generated data on occupations. In another alternative means, animation may be employed to present computer-generated "people" who serve as interviewees. Animation provides the opportunity to introduce special characterization to the interviews which may appeal more readily to younger users.
Upon selection of a particular career file, the user is provided with a menu of questions which were propounded to the interviewee. The questions propounded to each interviewee in any career or occupation may typically be the same. Thus, for example, the user of the interactive means of the present invention may inquire, "What education does your job require?", "What type of training is required for your job?", "What is your salary range?", and the like. The user may select one or more questions to be answered relating to a specific career. The user may then select another career or occupation, and may select for answering the same one or more questions. By doing so, the user may then compare the response to a single question propounded with respect to two or more career.
The method of the invention using interactive computer-aided or CD-ROM technology to selectively access information relating to one or more career facilitates self-directed and individualized searching of career opportunities. The method can thus be tailored to meet the unique inquiries and needs of the individual user. Further, the interactive means of the present invention is structured to provide the compiled information on career and occupational opportunities in one or more languages, such as English and Spanish, which permits the same system to be used by persons who are functional in English and/or other languages. Information provided in interview formats may also be available in American Sign Language. The ability to access the same information in a variety of languages provides the added advantage of acclimating non-English speaking persons to the type of issues or language which may be raised in a job interview with an English-speaking employer.
Still other objects and advantages of the invention will become readily apparent to those skilled in the art from the following detailed description, wherein the structure and method illustrated herein are described. As will be realized, the invention is capable of other and different embodiments, and its elements are capable of modifications in various respects, all without departing from the invention. Accordingly, the drawings and description are to be regarded as illustrative in nature, and not as restrictive.
BRIEF DESCRIPTION OF THE DRAWINGS
In the drawings, which illustrate what is currently considered to be the best mode for carrying out the invention:
FIG. 1 is an isometric view of a personal computer;
FIG. 2 is a flow diagram representing the accessing of information by the interactive means of the present invention; and
FIGS. 3(a)-3(e) are representations of various computer screens viewable during operation of the program.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
The interactive means of the present invention may be carried out in any suitable computer-aided software and hardware means. However, the use of CD-ROM technology to provide the interactive career search program of the present invention is described as an exemplar means of carrying out the invention. The program allows a user to access information on specific careers and interact with persons employed in those fields. The user can also access specific information within each career choice through a list of provided questions.
As shown in FIG. 1, the method of accessing career information effectively begins when the user chooses a compact disc 12 on which is encoded by conventional means information relating to one or more career or occupations. The information on any single disc 12 may be organized and encoded in any suitable manner and, for example, may contain career information relating to a particular field of interest or to a particular level of education, or the like. Once the main program, as diagrammed in FIG. 2, is accessed, the monitor 14 of the computer 10 will display the start-up screen 100 as shown in FIG. 3(a). The selections which appear on the green for accessing the encoded information may be selected by use of a mouse or cursor clicked on the appropriate portion of the screen, or by other means known in the art. As shown in FIGS. 2 and 3(a), the user may select "Begin" 102 to start the program 40. Once started, the program 40 accesses information encoded in the disc 12 which causes to be displayed a career menu screen 110 identifying those careers 120 contained on that particular disc 12, as shown in FIG. 3(b). For example, if a user is interested in an "art-skilled" career, the user may select and insert a disc 12 containing numerous accessible sub-files, each sub-file containing information concerning a career relating to the arts. The program first displays a menu comprising a first level of inquiry providing selection of those careers 120 which are encoded in the sub-files on that disc 12.
Once a particular career sub-file 122 has been selected, the program may then display a split screen 130 as shown in FIG. 3(c). On the left side 134 of the split screen 130 is a window 132 in which a person 142 being interviewed regarding a chosen career 122 is observed. In a preferred embodiment, the interviews are a digitized form of a videotaped interview with a person employed in that particular career or occupation. The interview is composed in a manner which gives the system user the sense of interviewing the person directly. The videotaped interview may be digitized in any manner known in the art, including MPEG compression technology.
On the right side 136 of the screen appears a list 138 of specific questions provided for the user to select from for response by the interviewee. Once a particular question 140 is selected, that portion of the program 40 or sub-file 122 is accessed which contains the interviewee's 142 response to the question 140. The user may select for response as many or as few questions as desired, and may move through the questions in any order. Multiple pages of questions may be selected by selecting the "MORE QUESTIONS" box 144 on the screen using a mouse or cursor.
The user may exit from a sub-file 122 and return to or re-access the career menu screen 110 at any time and select another career sub-file 120, or choose another field of interest with different career choices by inserting another compact disc 12. The user may also quit 112 the program. In doing so, the user can spend as much or as little time searching career information as desired, get detailed information from one or more careers, or ask specific questions from many different careers for comparison purposes. Thus, the user can tailor the program to obtain specific information.
While the questions propounded to the interviewee may be of a more personal nature, the user may access more factual information encoded with each sub-file about a particular career or occupation, such as current market forecasts for hiring trends in a particular career. Thus, as shown in FIG. 3(d), the user may, by selecting the "REFERENCE" 154 box, replace the person 142 interviewed regarding a particular career 122 with text 150 provided from a database compiled, for example, from government resources on occupations, market forecast periodicals, and the like. The user may access written information that corresponds to a selected question 140 otherwise propounded to the interviewee, or to other questions relating more specifically to factual information about the career (hiring trends, etc.). The ability to select between an audible digitized interview and written or textual information is facilitated by encoding with the sub-file a field of data comprising the digitized interview and a field of data comprising the textual information. The structure and encoding of these fields within the sub-file is well-known in the art. While in the "REFERENCE" 154 mode, the user also has an option to download and print 152 the textual information by accession of conventional commands.
Throughout the operation of the program, the user has the option of selecting from between two or more preferred languages, including English 104. Thus, within each sub-file, a field of encoded data comprises the list of randomly selectable questions in the English language, and other fields may have encoded substantially the equivalent questions in other languages. Other encoded fields of data provide the textual information in English and other languages accordingly. Additionally, other fields of data are encoded with digitized audio voice-overs corresponding to the questions responded to by the interviewee. Selection of a language other than the default language of English queues the program to access the appropriate fields of data corresponding to questions, interview voice-over or textual information in the same language.
Spanish 106 may typically be a common alternative language choice, as well as Vietnamese, Chinese. German, Polish, Italian, or many others. if, for example, Spanish 106 is selected, as shown in FIG. 3(e), the textual information accessible through the "REFERENCE" 154 selection will appear in the Spanish language. If the user selects to propound questions to the interviewee 142 as described hereinabove, the user will see the questions appear in the newly selected language and will hear the interviewee respond to the question in the selected language. Thus, if Spanish is selected, the user will see the questions in Spanish and will hear the questions responded to in the Spanish language. Further, when a language other than English is selected, the function keys 102, 112, 154 and 156 appear in the newly selected language, as illustrated in FIG. 3(e).
The interactive means is also structured with fields of dan in various sub-files to permit heating-impaired persons to access the same information. One of the selectable language buttons may be, therefore, ASL (American Sign Language). When ASL is selected, the program will access from memory a super-imposed box to appear within the window 132 on the left-hand side of the split screen 130 and a person may be observed interpreting the interviewer's response in ASL. Alternatively, a box may appear at the bottom of the window 132 in which the response will appear in writing, similar to a subtitle.
The interactive means of the system may be further explained by referring to FIG. 2. The user inserts the disc 12 and starts the program 40. As shown, the user has the option throughout the program to choose a language 46 other than the one currently being used. The system is structured to default to English. Once initiated by selecting "BEGIN" 102, the program 40 accesses from memory a career menu screen 110. If a desired career 122 is not displayed on the career menu screen 110, the user may "QUIT" 112 the program and replace the disc 12 with another. If a desired career 122 is displayed in the menu, the user can select the career 122 by use of a mouse or cursor clicked on the desired career. At this point, the user can either continue or select another career 56 by going back to the careers menu screen 110. Once a career 122 has been selected the selected sub-file is accessed from memory and the split screen 130 will appear. The user may then chose a question 140 to be answered. The response to the question may be shown in text 150 by selecting "REFERENCE" 158 or may be responded to by a person 142. The system will automatically default to displaying the interviewee. In the "REFERENCE" 158 mode, the user has an option to print 152 the information. At this time, the user can either ask another question 54, go back to the careers menu screen 110 by selecting "MAIN MENU" 156, or quit by selecting "QUIT" 112 at the careers menu screen 110.
Accordingly, described herein is a system and method for interactively accessing career information by computer-generated or computer-aided means. In this approach, the user can selectively access information regarding career opportunities in a serf-directed and individualized manner. The interactive means of the present invention thus provides easy and quick access to career and occupational information precluding the need to access outside information or to personally contact individuals from particular career fields. Further, the interactive means presents an interesting and animated means for accessing the information.
The general system and means of providing easily and interactively accessed information relating to careers may be adapted in a variety of manners to suit the level of the user (e.g., junior high school children to college level adults), the type of information sought regarding various careers or occupations and the type of technology available, including multiple interface capabilities between various computer system compatibilities. Hence, reference herein to specific details of the illustrated embodiment is by way of example and not by way of limitation. It will be apparent to those skilled in the art that many additions, deletions, and modifications to the illustrated embodiments of the invention may be made without departing from the spirit and scope of the invention as defined by the claims which follow. | A method for accessing career information located in a computer database through interactive CD-ROM technology or other suitable computer-accessible means. The method involves the use of several levels of inquiry from which a user can select various careers, and for each career ask specific questions. The answers to these questions can be answered through digitized speech and video enactments of a person employed in a particular career field, or through text displayed on a computer screen. The textual material contained in the database can be printed through an attached printer. The user may also operate the method in various selectable languages. | 6 |
FIELD OF THE INVENTION
This invention generally relates to copy sheet handling mechanisms and, particularly, to a system for proofing copy sheets in a printing, duplicating and like machine.
BACKGROUND OF THE INVENTION
Printing, copying or duplicating machines, such as rotary offset lithographic duplicating machines, normally are provided with some form of sheet receiving means at the exit end of the machine for stacking copy sheets issuing from the machine. Conventionally, the sheet receiving means include a receiving tray for receiving and stacking the sheets as the sheets fall by gravity and come to rest onto the top of a stack in the tray.
Many such machines employ conveyor means for delivering the sheets seriatim in a path outwardly over the receiving tray. Conventionally, the conveyor means includes a rigid gripper bar extending transversely between a pair of generally parallel, endless drive chains. Such conveyor means commonly are called chain delivery devices. The gripper bar has gripper fingers which grasp the sheets issuing, from the machine and direct the sheets outwardly over the receiving tray whereat the gripper fingers are timed for release of the sheets at very high speeds. Upon release, the sheets have a tendency, due to momentum to continue in their path of directed travel. Stripper devices, usually including stripper fingers which are transversely spaced so that the gripper fingers can pass therebetween, are used for engaging the lead ends of the sheets as the sheets issue from the conveyor means, "stripping" the sheets from the conveyor means, and directing the sheets downwardly into the receiving tray.
In some instances, the machine has some form of proofing mechanism at the exit end of the machine near the receiving tray. These mechanisms are provided whereby one or more sheets can be diverted or taken out of the normal stacking procedure in order to proof the copy for quality or apparent problems. For instance, it has been known to position an interrupter plate into the stack of sheets for pulling a sheet out of the stack for proofing purposes and so that continuous delivery of the sheets onto the stack is not interrupted.
Proofing copy sheets becomes a considerable problem in machines which have finishing stations, particular where the sheets are sequentially numbered. A very common example is serially numbered bank checks or drafts. Of course, there are many other instances where it is desirable to number the copy sheets as they exit from the printing couple of the machine.
It can be understood that if a numbered copy sheet is removed from the normal delivery system, that numbered sheet must somehow get back into the stack in its proper place or order. This can be very time consuming and, with heavy stock paper or large size copy sheets, very cumbersome. Further, placing the proofed copy back into the stack most often disorients the stack and causes problems with further processing of the copy sheets.
This invention is directed to a novel system for proofing copy sheets exiting from a printing or duplicating machine, particularly in applications where the machine includes a sheet numbering system.
SUMMARY OF THE INVENTION
An object, therefore, of the invention is to provide a sheet proofing mechanism for use in a printing, duplicating and like machine wherein sheets are delivered seriatim by conveyor means in a path over a receiving tray or the like, whereat the sheets drop onto a stack of sheets in the tray, with releasable gripping means on the conveyor means and stripping means for stripping each released sheet from the conveyor means and directing the sheet into the tray.
Generally, the sheet proofing mechanism includes deflecting means spaced along the sheet path from the stripping means for deflecting a released sheet from the conveyor means to a proofing station. Tripping means are provided along the path operatively associated with the gripping means for selectively releasing the gripping means at a first point to allow the stripping means to strip a released sheet from the conveyor means and at a second point to allow the deflecting means to deflect a released sheet to the proofing station.
In the disclosed embodiment, the tripping means comprises a singular, selectively movable adjustable cam member having a first cam portion movable into position for engaging and tripping the gripping means at the first point along the sheet path, and a second cam portion movable into position for engaging and tripping the gripping means at the second point along the path. Specifically, the cam member is in the form of a rotatable plate having a peripheral surface whereby selective rotation of the cam plate brings first and second peripheral surface portions into and out of positions at the aforesaid first and second points for tripping the gripping means.
As stated above, the invention has particular applicability in machines which include a numbering head for sequentially numbering the copy sheets. Conventionally, such numbering heads have indexing means for indexing the head to present sequential number imprints. The invention contemplates that the proofing mechanism includes interruption means for preventing operation of the indexing means on the numbering head, whereby a given sheet will not be sequentially numbered and such that the given sheet can be selectively deflected to the proofing station by the tripping means without interrupting the remaining order of sequential numbering. Control means are provided for actuating the interruption means and the tripping means, preferably including time delay means for actuating the interruption means prior to actuating the tripping means. The time delay is for the purpose of allowing the given sheet time to move from the numbering head to the area of the receiving tray and tripping means.
Other objects, features and advantages of the invention will be apparent from the following detailed description taken in connection with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
The features of this invention which are believed to be novel are set forth with particularity in the appended claims. The invention, together with its objects and the advantages thereof, may be best understood by reference to the following description taken in conjunction with the accompanying drawings, in which like reference numerals identify like elements in the figures and in which:
FIG. 1 is a schematic illustration of a printing machine in which the invention is applicable;
FIG. 2 is a somewhat schematic illustration of the components at the exit end of the machine for stacking copy sheets and for proofing selected sheets;
FIG. 3 is a perspective view of the deflecting finger assembly for the proof sheets;
FIG. 4 is a perspective view of the assembly of FIG. 3, looking toward the rear thereof, and showing the proofing tray for receiving copy sheets;
FIG. 5 is a fragmented perspective view of one end of the deflecting assembly, along with portions of the chain delivery means and tripping cam;
FIG. 6 is a fragmented perspective view looking at the back side of FIG. 5, with the deflecting finger assembly removed to facilitate the illustration;
FIG. 7 is a fragmented perspective view of the opposite end of the machine from that shown in FIG. 6;
FIG. 8 is a fragmented perspective view illustrating the micro-switch means for the stray sheet tripping rod;
FIG. 9 is a somewhat schematic illustration of the tripping cam in position for tripping the gripper fingers at a first point along their path of movement;
FIG. 10 is a view similar to that of FIG. 9, with the cam rotated to trip the gripper fingers at a second point along their path of movement; and
FIG. 11 is a somewhat schematic illustration of the interrupter means for preventing indexing of the numbering heads on the numbering drum.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring to the drawings in greater detail, and first to FIG. 1, the invention is disclosed in conjunction with a printing, copying or duplicating machine, such as a rotary offset lithographic duplicating machine, generally designated 10, the majority of which is shown in phantom in FIG. 1. The machine may include one or more printing couples, located in areas of the machine generally designated 12. Copy sheets are delivered from the printing couple by appropriate conveyor means to some form of receiving means at an exit end, shown in full lines and generally designated 14, of the machine for stacking the copy sheets. Conventionally, the sheet receiving means is in the form of a receiving tray for receiving the sheets as the sheets fall by gravity and come to rest onto the top of a stack, generally in the area designated 16, in the tray.
FIG. 2 is a somewhat schematic illustration of the major components at the exit end 14 (FIG. 1) of the machine for stripping copy sheets "C" off of a conveyor means, generally designated 18, and directing the sheets downwardly onto a stack "S" of sheets in a receiving tray 20. The proofing mechanism, described hereinafter, deflects the sheets to a proofing station, i.e., into a proofing tray 22.
More particularly, a chain delivery-type conveyor means includes an endless drive chain including an upper run 24 and a lower run 26 whereby the chain moves in the direction of arrows "A". As is known, a pair of such endless drive chains are mounted in parallel and spaced transversely at opposite sides of the paper path. Conventional gripper fingers 28 are mounted at spaced intervals on gripper bars 30 which are mounted transversely between the parallel chains and at spaced intervals longitudinally of the chains, as is known. As also is conventional, the gripper fingers grasp the sheets issuing from the machine off of an impression cylinder, described hereinafter, and move the copy sheets generally in a paper path as indicated by arrow 32. At an appropriate point along the path of travel of the sheets, shown in FIG. 2 as point "X", some form of tripping mechanism will open gripper fingers 28 whereby appropriate stripping means will strip the sheets from the chain delivery device and direct the sheets downwardly, as indicated by arrow B, onto stack "S" of sheets in receiving tray 20. In the illustrated embodiment, the stripping means are in the form of stripper fingers 34. In some machines, air jets are used as the stripping means to divert the sheets from the path into the receiving tray. Up to this point, the operation of the chain delivery device, stripping means, etc. is generally known in the art.
The invention contemplates deflecting means spaced along path 32 from point "X" for deflecting a sheet from the conveyor means, in the direction of arrow "C" to proofing tray 22. More particularly, referring to FIGS. 3, 4, and 5 in conjunction with FIG. 2, the deflecting means include a plurality of deflecting fingers 36 having curved rear ends 36a, the curved rear ends being effective to curve or bend a sheet downwardly into proofing tray 22 as shown best by arrow "D" in FIG. 4. As seen in FIG. 3, two of the deflecting fingers have pressure rollers 38 for purposes described hereinafter. Guide fingers 40, as shown in FIGS. 2 and 5 (also see FIGS. 6 and 7) are located below deflecting fingers 36 but stop short (at their rear ends), of curve portions 36a of the deflecting fingers. An appropriately released copy sheet, as described hereinafter, passes between guide fingers 40 and deflecting fingers 36 (actually, above guide fingers 40 and below deflecting fingers 36), and then into proofing tray 22 as a result of curved finger portions 36a.
In order to facilitate deflection of a released sheet from the gripper fingers of the conveyor means into proofing tray 22, a plurality of rollers 42 (FIGS. 5 and 6) are fixed to a shaft 44 and appropriately continuously rotated by motor means 46 (FIG. 6) to provide a positive drive in the direction of arrows "E" toward the proofing station or tray. The two pressure rollers 38 shown in FIG. 3 on two of the deflecting fingers 36 form a nip with two of the driven rollers 42 to positively drive a sheet against curved finger portions 38 and into the proofing tray. To this end, the two deflecting fingers 36 which mount rollers 38 are spring loaded, as at 48 in FIG. 3.
In order to better illustrate the deflecting fingers, it should be noted that FIG. 3 shows a deflecting finger assembly, generally designated 50, which includes a transverse rod 52 fixed between a pair of end mounting blocks 54. The view of FIG. 3 has been reversed in relation to FIGS. 6 and 7 in order to give a full illustration of the deflecting finger arrangement. With this understanding, and referring to FIGS. 6 and 7, transverse rod 52 seats in a saddle 56 at the top of rigid frame members 58, and stub shafts (not shown) pass through holes 59 in frame blocks 60 (FIGS. 6 and 7) and through holes 62 in mounting blocks 54 (FIG. 3). Saddles 56 are slightly wider than the diameter of rod 52, whereby the entire deflecting finger assembly 50 can pivot about an axis defined by holes 59, 62 and the appropriate stub shafts extending therethrough. It can be understood when viewing the assembly shown in FIG. 3, that the deflecting fingers 36 cause the assembly to be "top heavy" whereby the assembly will lean in the direction of arrow "F" about the pivot defined by holes 62. Arrow "F" is shown in the opposite direction in FIG. 6. In other words, the entire gripper finger assembly leans forwardly relative to the machine, as can be seen in FIG. 5.
FIG. 6 shows a micro-switch, generally designated 64, having a switch button 66 biased by a leaf spring switch actuator 68 opposite the "leaning direction" of deflecting finger assembly 50, i.e., opposite the direction of arrow "F" (FIG. 6). The first switch means (micro-switch 64) is appropriately connected to the main drive system of the machine and provides a safety feature should sheets become jammed between deflecting fingers 36 and guide fingers 40. The pressure of the jammed sheets will pivot the finger assembly opposite the direction of arrow "F" and rod 52 will move away from micro-switch button 66, whereupon leaf spring switch actuator 68 will trip the micro-switch to shut down the machine.
Another safety feature is shown in FIGS. 5, 7 and 8 and includes a small diameter safety rod 70 extending transversely across the top of deflecting finger assembly 50 (see FIG. 5) and into enlarged apertures 72 (FIGS. 5 and 7) in blocks 74 fixed to frame members 58. Springs (not shown) in blocks 74 bias safety rod 70 forwardly in the direction of arrow "G". As seen in FIG. 8, safety rod 70 passes across a second switch means, namely microswitch 76, which includes a switch button 78 located immediately behind bar 70. This provides a safety feature should a sheet "miss" the nip between deflecting fingers 36 and guide fingers 40 (or between upper pressure rollers 38 and lower driven rollers 42). Such a stray sheet sometimes is termed a "wild" sheet and, in essence, flies out of the normal sheet path because of a variety of reasons such as momentary air currents. Such a stray sheet can jam the machine severely and cause all kinds of bending, breaking or other damage to the machine components, such as the stripper fingers, deflector fingers, guide fingers, bars, shafts, etc. Should such a stray sheet miss the nip between the deflecting fingers and the guide fingers and become jammed against safety rod 70, the rod will move away from switch button 78 and trip the switch to shut down the machine.
Referring to FIGS. 9 and 10 in conjunction with FIG. 2, generally, tripping means in the form of a cam plate 80 is provided adjacent paper path 32 (FIG. 1) and in the path of gripper fingers 28 on the lower run 26 of conveyor means or chain 18. Specifically, as stated above, point "X" (FIG. 2) represents the point at which it is necessary to trip or open gripper fingers 28 in order that the copy sheets be stripped by stripper fingers 38 for delivery onto stack "S" in receiving tray 20. However, when it is desired to eject or deflect a sheet for proofing purposes, the sheet must bypass point "X" and the gripper fingers must be released at a point "Y" further rearwardly of the path so that the sheet can be deflected into proofing tray 22 as described above.
To this end, and referring to FIGS. 9 and 10, tripping cam 80 is rotatably mounted on the machine by a stub shaft 82 which is fixed to one end of a lever arm 84. The opposite end of the lever arm is connected to a piston shaft 86 of a piston-and-cylinder device 88. Therefore, the piston-and-cylinder device moves lever arm 84 in the direction of double-headed arrow "H" which, in turn, effects rotation of tripping cam 80 about shaft 82. Gripper fingers 28 are shown somewhat schematically in FIGS. 9 and 10 because they are widely known in the art, including some form of tripping mechanism for engaging a cam follower 90 which opens the gripper fingers, as at 92, to release the copy sheet.
FIG. 9 shows tripping cam 80 in a position where a first peripheral cam portion or lobe 94 is located in the path of travel of cam follower 94 for tripping or opening the gripper fingers. This represents the first point "X" in FIG. 2.
FIG. 10 shows piston-and-cylinder device 88 having rotated tripping cam 80 such that lobe 94 has been moved upwardly in the direction of arrow "I" out of the path of movement of cam follower 90 on the gripping fingers. Therefore, it can be understood that the gripping fingers will move past point "X" in FIG. 2. However, that rotation of tripping cam 80 causes a second portion 96 of the cam plate to be moved downwardly in the direction of arrow "J" (FIG. 10) into the path of travel of cam follower 90. The second peripheral cam portion 96 is located spaced from and down line of first peripheral cam portion 94 to define point "Y" in FIG. 2 at which the gripper fingers are opened to release the sheet for deflection into proofing tray 22, as described in detail above.
As stated heretofore, and referring to FIG. 11, the proofing system of the invention is particularly applicable for machines which include a finishing station, particularly a machine which is capable of sequentially numbering the copy sheets as they issue from the machine. FIG. 11 shows an impression cylinder 98 of the machine, along with a numbering drum 100 which includes one or more numbering heads, generally designated 102. The numbering heads are standard assemblies and include an indexing lever 104 which, when tripped or actuated, indexes the numbering head to the next sequential number. Some form of tripping cam 106 is located on the machine in the path of travel of the indexing levers 104 to momentarily move the levers and index the numbering head to the next number. This general arrangement is known in the art. However, the invention contemplates the provision of interruption means for preventing operation of the indexing of the numbering head so that a given sheet will not be sequentially numbered and such that the given sheet can be selectively deflected to the proofing station as initially effected by rotation of tripping cam 80 (FIGS. 9 and 10).
More particularly, cam 106 is fixed to a shaft 108 which, in turn, is fixed to one end of a lever arm 110. The opposite end of lever arm 110 is connected to a piston rod 112 of a second piston-and-cylinder device 114. Therefore, upon actuation of the piston-and-cylinder device to move lever arm 110 in the direction of arrow "K", cam 106 will be moved to the phantom position shown in FIG. 11 and out of the path of rotation of indexing lever 104. Consequently, the sequential numbering of the sheets are interrupted and the numbering head simply repeats the previous number for one or more copy sheets depending upon how many sheets are to be deflected into proofing tray 22.
Appropriate control means are provided for actuating piston-and-cylinder devices 88 and 114. A variety of control means can be utilized, ranging from manual switches whereby an operator first can actuate piston-and-cylinder device 114 to interrupt the numbering cycle and immediately thereafter actuate piston-and-cylinder device 88 to deflect the copy sheet which is not sequentially numbered However, in high speed duplicating machines, the control means can be incorporated in the microprocessor of the machine which controls the myriad of timing cycles for the feeding system, registration system, roller rotation synchronization, sheet transfer mechanisms, etc.
FIG. 11 schematically shows a microprocessor 116 coupled by a line 118 to a solenoid 120 for controlling piston-and-cylinder device 114. A line 122 (which is picked up in FIG. 9) leads to a solenoid 124 for actuating piston-and-cylinder device 88 for tripping cam 80. A time delay "T" is built into the microprocessor so that piston-and-cylinder device 114 is effective to interrupt the numbering system before piston-and-cylinder device 88 is effective to deflect a sheet into the proofing tray. This delay is necessary because of the distance the sheet travels off of impression cylinder 98 along conveyor means 18 to the rear deflecting area of the machine. Of course, as with all of the other functions of the machine, this time delay is variable depending upon the size of sheets being run through the machine. For instance, such microprocessors must be set to correlate the feeding station with other transfer mechanisms throughout the machine for longer and shorter sheet sizes.
It will be understood that the invention may be embodied in other specific forms without departing from the spirit or central characteristics thereof. The present examples and embodiments, therefore, are to be considered in all respects as illustrative and not restrictive, and the invention is not to be limited to the details given herein. | A sheet proofing mechanism for a printing, duplicating and like machine wherein sheets are delivered seriatim by a conveyor in a path over a receiving tray whereat the sheets drop onto a stack of sheets in the tray. Releasable gripping fingers are provided on the conveyor, and stripping fingers strip each released sheet from the conveyor and direct the sheet into the tray. A sheet proofing mechanism includes deflecting fingers spaced along the path from the stripping fingers for deflecting a released sheet from the conveyor to a proofing station. A tripping cam is provided along the path for selectively releasing the gripping fingers at a first point to allow the stripping fingers to strip the released sheet from the conveyor and at a second point to allow the deflecting fingers to deflect the released sheet to the proofing station. The machine also includes a numbering head for sequentially numbering the sheets, with an indexing lever for indexing the numbering head. The proofing mechanism includes an interrupter for preventing operation of the indexing lever whereby a given sheet will not be sequentially numbered and such that the given sheet can be selectively deflected to the proofing station without interrupting the remaining order of sequential numbering. | 1 |
FIELD OF THE INVENTION
[0001] The invention is directed generally to an ophthalmological process, and more specifically to a process to improve, maintain, or reduce loss of visual acuity in a patient having or at risk for developing macular degeneration.
BACKGROUND OF THE INVENTION
[0002] In the mammalian eye, macular degeneration (also called age related macular degeneration, AMD) is a pathological condition that is the most common cause of legal blindness among individuals over the age of 60, with an incidence ranging from 11% to 18.5% in individuals over the age of 85. In the United States, AMD affects roughly 3.6 million individuals, with over 200,000 new cases developing annually.
[0003] One type of AMD results in proliferation of new blood vessels in the subretinal area, typically the choroid. In the normal retina, both the large blood vessels and the capillaries have intact vessel walls. In the normal choroid, the large vessels have intact vessel walls, but the capillaries have fenestrations or openings in their walls. In patients with AMD, new blood vessels proliferate from the choriocapillaries through defects in Bruch's membrane beneath or on top of retinal pigment epithelium (RPE), and form vascular membranes. The resulting choroidal neovascularizations (new vessels in the choroid) occur in about 8-10% of all patients with AMD, and are also seen in patients with pathologic myopia and presumed ocular histoplasmosis syndrome, as well as other idiopathic conditions.
[0004] While the presence of the new vessels themselves is not problematic, any endogenous or exogenous fluid contained in these vessels (for example, blood, serous fluid, solubilized drug, etc.) will leak outside of the vessels and into the surrounding spaces. This accumulation of fluid can result in serous and hemorrhagic detachment of the RPE and neurosensory retina, and can lead to scarring in this area (fibrous deform scarring), resulting in decreased vision or even loss of vision. Thus, it is the fluid leakage from these new vessels in this type of AMD, called neovascular, exudative, or occult AMD, that is the cause of the resulting visual impairment.
[0005] Another type of AMD occurs less commonly and is due to dead RPE cells; this is termed atrophic AMD. In either type of AMD, without treatment, many of the affected individuals will become legally blind.
[0006] Patients with an early stage of AMD can be diagnosed in an examination by the presence of abnormal clumps of pigments in the eye. Accumulated dead outer segments of photoreceptor cells under the RPE is termed drusen. Hyaline excrescences that are located in Bruch's membrane (lamina basalis choroidea) also form. The presence of large, soft drusen in the eye indicates a pre-stage of exudative AMD, and places patients at higher-than-average risk for developing neovascularizations, especially if one eye is already affected.
[0007] To date, there are no known specific measures to prevent the occurrence of AMD. Nutritional therapies using antioxidants and zinc have been tried. There is one report ( Ophthalmology 105:11-23, 1998) of a clinical trial using lasers to prophylactically treat patients showing abnormal pigment in both eyes (bilateral drusen).
[0008] For patients already diagnosed with AMD in one or both eyes, treatment involves targeting light (phototherapy) to the macular area containing the nascent defective blood vessels to inhibit or impair their function. One type of phototherapy is photodynamic therapy (PDT). In PDT, a photosensitive agent is administered into the vessels of a patient, then the agent is activated at the target site of the new vessels (the macula) by directing low energy light from a laser specifically to this area. The activated agent generates free radicals and other activated chemical species which destabilize and destroy the new vessels.
[0009] PDT has been reported to be of some benefit to patients having AMD. For example, one study ( Arch. Ophthalmol. 17:1329-1345, 1999) evaluated PDT in four hundred and two eyes from patients diagnosed with AMD in at least one eye. Treatment outcome was assessed by comparing the patient's ability to accurately read a conventional vision chart (one having about five letters per line) pre-treatment and post-treatment. At twelve months post-PDT, 61% of the eyes (246/402) lost fewer than 15 letters (that is, the patient lost less than about three lines on a standard visual chart), while 46% of the eyes (96/207) from patients undergoing treatment with a placebo lost fewer than 15 letters (p<0.001). At twenty-four months post-PDT, the visual acuity and contrast sensitivity was sustained in patients receiving PDT. A significantly greater percentage of these patients (58%) lost fewer than 15 letters, compared to patients undergoing treatment with a placebo (38%). However, only 16% of the patients receiving PDT had improved vision, compared to 7% of the patient receiving a placebo.
[0010] Another type of phototherapy is photocoagulation therapy. In photocoagulation therapy, high energy light from a laser is directed specifically to the target site of the new vessels. The heat generated from the high energy laser coagulates the fluid in and around the new vessels. Laser photocoagulation is not a form of PDT; it is a separate treatment approach. It uses lateral transfer of heat, applied with a cautery-like method, to coagulate fluid within and surrounding the vessel, while PDT uses an activated photosensitive agent to generate active chemicals which damage or destroy the new vessels.
[0011] While either PDT or laser photocoagulation therapy is separately used to treat patients with AMD, neither is without drawbacks. A problem with PDT is that its effects are transient; patients receiving PDT must be retreated about every three months. Furthermore, the patients require at least five retreatments within the first two years merely to stabilize their condition, and before any therapeutic effect occurs. These cumulative treatments damage the retina, further reducing the patient's visual acuity.
[0012] One drawback of laser photocoagulation is that it is non-selective, and does not target only the new blood vessels. It must therefore be administered so that only the lesions are targeted, and the unaffected surrounding tissues are undamaged. However, in about half of the patients with AMD, the new vessels are located in the subfoveal area, which is difficult or impossible to target with laser coagulation without damaging the sensory retina. Another drawback is that photocoagulation treatment is not permanent and recurrence rates for new vessel production are high, reaching 39-76%, usually within the first two years. However, repeated treatments can actually induce the growth of new vessels and membranes (subretinal neovascular membranes and recurrent choroidal neovascularizations) at the site of the treatment. Repeated treatments may also irreversibly damage unaffected areas of the retina, including the neurosensory retina and RPE. Thus, the treatment itself may result in the patient having further reduced vision over a period of time. Specifically, some patients undergoing photocoagulation therapy develop scotoma, which is an area of depressed vision within the visual field, surrounded by an area of less depressed or of normal vision.
[0013] Methods to further refine the treatment of AMD to reduce or eliminate the above-described problems are therefore needed. Methods to prevent or delay the onset of AMD, and methods to maintain visual acuity and prevent further loss of vision in patients with AMD, are also needed.
SUMMARY OF THE INVENTION
[0014] The invention is directed to a method to prevent, alleviate, or delay the onset of AMD in a patient by administering photodynamic therapy (PDT) simultaneously or concomitantly with laser coagulation therapy. The invention is also directed to a method to prevent the progression of AMD, and to reduce further loss of vision in a patient having AMD, by administering PDT simultaneously or concomitantly with laser coagulation therapy. Surprisingly and beneficially, with the combined therapies, there is no need for retreatment of patients, as is required when PDT is separately administered, and there are no laser-induced neovascularizations, as occur when laser coagulation therapy is separately administered. Another benefit of the invention is that visual acuity is either maintained or is improved, without further loss of vision. The inventive therapy may be administered in any sequence, that is, laser coagulation therapy may be administered before or after PDT, or simultaneously with PDT. The invention can be used for both exudative and atrophic types of AMD.
[0015] An effective amount of a photosensitive agent for PDT is administered to a patient. The photosensitive agent is activated by low energy light that is directed to the neovascular target site using a laser (non-thermal laser). The photoactivated agent produces activated oxygen species, such as hydroxyl radicals and other radicals, that damage the new vessels, and may occlude the vessels. High energy light sufficient to create heat is also directed to the neovascular target site using a laser (thermal laser), resulting in coagulation of the fluid within and surrounding the new vessels. Either PDT or laser coagulation may be performed first, and the time between the two therapies may be within a few minutes, within a few hours, within a few days, or up to ninety days. PDT and laser coagulation may also be performed essentially simultaneously.
[0016] The invention is also directed to a method to improve visual acuity, and/or prevent further loss of vision in a patient already diagnosed with AMD, using the method described above.
[0017] The invention is further directed to a method to reduce the recurrence of new vessels in an eye of a patient having undergone PDT to treat AMD by further treating the patient with laser coagulation therapy concomitantly with the PDT in progress. The laser coagulation therapy may be administered within a few minutes of PDT, with a few hours of PDT, within 24 hours of PDT, or even ninety days after PDT. Alternatively, the laser coagulation therapy may have been administered, and thereafter the patient's standard PDT may be administered within a few minutes, within a few hours, within 24 hours, or up to ninety days after laser coagulation therapy.
[0018] The invention is also directed to a method to reduce the recurrence of new vessels in an eye of a patient having undergone laser coagulation therapy for AMD by further treating the patient with PDT concomitantly with laser coagulation therapy in progress, as described above. Alternatively, PDT may be administered first, and then the patient's standard laser coagulation laser therapy may be administered.
[0019] The invention is additionally directed to a method to minimize photosensitivity of a patient undergoing or having undergone PDT by administering the photosensitive agent to vessels of the patient and activating the agent with a low energy light, then treating the patient with plasmaphoresis to reduce the concentration of the agent in the patient's blood. In patients with AMD, plasmaphoresis is also beneficial in removing lipid components of the blood that may aggravate the disease, such as cholesterol and low density lipoproteins.
[0020] These and other embodiments of the invention will be further described in the following figures and detailed description.
BRIEF DESCRIPTION OF THE FIGURES
[0021] [0021]FIG. 1 is a schematic cross-sectional view of a mammalian eye.
[0022] [0022]FIG. 2 is an enlarged diagrammatic illustration of the circled area 2 of FIG. 1 showing detailed retinal and choroid structures.
DETAILED DESCRIPTION
[0023] With reference to FIG. 1, a mammalian eye 10 is shown. The locations of the anterior chamber 11 , cornea 12 , conjunctiva 13 , iris 14 , optic nerve 15 , sclera 16 , macula lutea 17 , lens 18 , retina 20 and choroid 22 are illustrated.
[0024] [0024]FIG. 2 is a diagrammatic enlargement of the circled area of FIG. 1. Between the retina 20 and the choroid 22 there is an outer segment of photoreceptor cells 24 including rods and cones, a subretinal space 25 , and a layer of retinal pigment epithelium (RPE) 26 . In a normal adult, retinal blood vessels 28 , including capillaries, have walls or membranes 29 that contain no fenestrations or openings. In a normal adult, the large choroidal vessels 30 similarly have walls 31 that contain no fenestrations but the choriocapillaries 32 have walls that contain fenestrations 34 . In an adult with macular degeneration (also called age related macular degeneration, AMD), there is either growth of new subretinal blood vessels whose walls or membranes are altered in that they also contain fenestrations, or the RPE cells are lost.
[0025] AMD is a pathological, progressive age-related degeneration in the macula lutea 17 of the retina 20 . The macula lutea 17 is located in the center of the posterior part of the retina 20 and is the most sensitive portion of the retina 20 . In the center of the macula lutea 17 is a depression, the fovea centralis 41 , from which rods are absent. About one-tenth inch inside the fovea 41 is the point of entrance of the optic nerve 15 and its central artery. At this point, the retina 20 is incomplete and forms the blind spot.
[0026] In exudative AMD, subretinal neovascular tissue 40 develops in the choroid 22 . The neovascular tissue 40 penetrates the RPE and subretinal space 25 , and extends into the area containing photoreceptor cells 24 . The neovascular tissue 40 has membranes or walls 42 that are altered in having fenestrations 34 , that permit fluid leakage into spaces surrounding photoreceptor cells 24 , the subretinal space 25 and the RPE 26 .
[0027] Neovascular tissue 40 results in visual impairment because of fluid leakage and accumulation in the spaces surrounding the new vessels. Therapies to prevent AMD are directed to slowing or stopping the formation or proliferation of new vessels in the choroid. Therapies to treat AMD are directed to at least partially damaging or destroy existing neovascular tissue 40 , and/or interfering with its function. In either case, leakage of fluid from the new vessels is decreased, and the concomitant scarring and loss of vision is likewise diminished or eliminated. Examples of such methods are disclosed in co-pending U.S. patent application Ser. Nos. 09/235,104 and 09/644,436, each of which is expressly incorporated by reference herein in its entirety.
[0028] The invention is directed to a method to prevent AMD in a minimally affected eye or an eye showing early stages of AMD, and to treat and thereby reduce vision loss in an AMD-affected eye, by treating the eye with photodynamic therapy (PDT) in combination with threshold laser coagulation therapy. The therapies may be administered in any sequence, that is, laser coagulation therapy may be administered before or after PDT, or they may be administered essentially simultaneously. The invention is applicable for both exudative and atrophic types of AMD.
[0029] The general principles by which PDT and laser coagulation affect AMD are as follows. PDT prevents or alters the function of the neovascular tissue by using low energy light to generate reactive species that damage the tissue. More particularly, the low energy light activates a photoactive or photosensitive agent that has been administered to a patient and which is contained within the new vessel. By targeting low energy light to the area containing the new vessel, the agent in this area is selectively activated. The activated agent generates singlet oxygen and other reactive oxygen radicals such as hydroxyl radicals, which damage the walls of the choriocapillaries and neovascular tissue, leading to an initial vascular thrombus. Threshold laser coagulation therapy slows or halts fluid leakage in an around the new vessels. It uses heat generated by high energy light in a laser to coagulate fluid within and surrounding the new vessels, preventing fluid escape from the leaky vessel wall and further penetration into the surrounding tissues.
[0030] PDT is a method for local and selective tissue or cellular destruction by the action of a particular wavelength of low energy light on the photosensitizing agent. The wavelength of light is selected to correspond to the absorbance spectrum of the photosensitizing agent. The agent capable of being photoactivated is administered into the bloodstream of a patient, usually by intravenous injection. The agent is transported in the blood to vessels 28 in the retina 20 . Either immediately thereafter, or after an appropriate interval, the agent is activated by directing light of the appropriate wavelength to this specific area. The size of the applied laser may be in the range of about 1 mm to about 9 mm.
[0031] The selection of the photosensitive agent depends upon several factors. These factors include the site or sites of tissue distribution requiring treatment, the mechanisms of action of the agents themselves, and their specific optimal absorption wavelengths. For example, tin ethyl etiopurpurin (SnET2), is frequently used as a photosensitive agent. SnET2 has several advantages, such as lower persistence and severity of skin photosensitivity, absorption at longer wavelengths yielding better tissue penetration, a higher extinction coefficient resulting in increased potency and efficiency, ease of synthesis, and ability to be produced in a highly pure form. Protoporphyrin is also a good photosensitizing agent. Protoporphyrin IX is a photoactive compound which is endogenously formed from 5-aminolevulinic acid (ALA) in the biosynthetic pathway of heme. ALA may be applied topically and is metabolized to protoporphyrin, the active photosensitizing agent. Laser irradiation is usually at a wavelength in the range of about 630 nm, or alternatively in the range of 670 nm. ALA may be administered orally in a bolus as an aqueous solution at a concentration of about 60 mg/kg body weight, or intravenously at a concentration of 30 mg/kg body weight. Other photosensitizing agents that may be used include, but are not limited to, benzoporphyrin derivative monoacid tube A (BPD-MA) and mono-l-aspartyl chlorine 6 (NPe6), with absorbance maxima in the range of about 660-690 nm, ATX-106, and indocyanine green (ICG).
[0032] Another photosensitive agent that may be used is verteporfin. Verteporfin is a synthetic, chlorin-like porphyrin. After intravenous injection at a dose of about 1-2 mg/kg, it is activated by light at 50 J/cm 2 (absorbance peak of drug) from a non-thermal laser (for example, a diode laser) set at an intensity of 600 mW/cm 2 and a wavelength of 689 nm. Once activated, it generates singlet oxygen and other reactive oxygen radicals that selectively damage neovascular endothelial cells, and cause thrombus formation due to specific choroidal neovascular occlusion.
[0033] Threshold laser coagulation therapy is performed by directing high energy light from any type of laser (for example, argon, krypton, or diode laser) to the macular area, as is known to one skilled in the art. Any wavelength of light (for example, visible light, infrared light) may be used. The energy delivered to create a very light lesion is tested on an extrafoveal area of the fundus. The laser creates multiple coagulation spots surrounding the fovea, and also has beneficial effects on reabsorption of the drusen. Patients having abnormal ocular pathology, such as extrafoveal pigment epithelial detachment, receive additional laser applications directed over these areas.
[0034] The size of the applied spots can vary, as can the number of spots applied. In one embodiment, the application spot size is between about 50 μm and about 500 μm. In another embodiment, the application spot size is about 200 μm. In yet another embodiment, the application spot size is greater than 500 μm. Generally, the smaller the spot size, the greater the number of spots that are applied; conversely, the larger the spot size, the fewer the number of spots that are applied. Thus, for smaller sized spots, the number of spots may be between about 50 to about 500 spots. In one embodiment, between about 150 to about 200 spots are administered. For larger sized spots, the number of spots may be between about 5 and about 50 spots. The spots are administered in the macula and adjacent area in a scatter fashion around the fovea. The duration of administration for each spot is between about 0.1 second to about 1 second, with an energy in the range of about 50 mW to about 500 mW.
[0035] In the inventive method, both PDT and threshold laser coagulation therapy are administered, but their administration is not restricted to a particular sequence. In one embodiment, PDT is administered and essentially simultaneously with or immediately thereafter laser coagulation therapy is administered. In another embodiment, PDT is administered and laser coagulation therapy is administered in the same treatment session, within a time frame of a few hours. In another embodiment, PDT is administered and laser coagulation therapy is administered after an interval from about one day up to about 90 days. In another embodiment, laser coagulation therapy is administered and essentially simultaneously with or immediately thereafter PDT is administered. In another embodiment, laser coagulation therapy is administered and PDT is administered in the same treatment session, within a time frame of a few hours. In another embodiment, laser coagulation therapy is administered and PDT is administered after an interval from about one day up to about 90 days.
[0036] In one embodiment, after administering the photosensitive agent (verteporfin, protoporphyrin, SnET2, NPe6, ATX-106, ICG, etc.), the patient is treated using a laser to administer low energy levels of light at a wavelength appropriate to activate the photosensitive agent. Threshold laser coagulation therapy is then essentially simultaneously or concomitantly initiated. Essentially simultaneously with includes administration of both high energy and low energy light within the same treatment session. Concomitant therapy includes administration either immediately thereafter or within a few hours, within 24 hours, or after an interval from about one day to ninety days.
[0037] In another embodiment, the patient is treated with threshold laser coagulation therapy, and is thereafter treated with PDT. The photosensitive agent may be administered either before or after laser coagulation treatment, depending upon a variety of factors such as the specific photosensitive agent used, the specific treatment protocol, etc. PDT is then simultaneously or concomitantly initiated, as described above.
[0038] Factors such as patient comfort, tolerance to treatment, and convenience may be factored into selecting the appropriate treatment regime. Exudates disappear within eight to ten weeks post treatment. The macula initially becomes dry, then improves and stabilizes after about three to six months post-treatment.
[0039] Patients who have been administered a photoactive agent are cautioned to avoid sunlight exposure for an appropriate period of time to prevent skin hypersensitivity. This period of time may vary, but is usually between five days and thirty days. During this time, the patient should minimize any time outdoors, and should take extra precautions when it is necessary to be outdoors. For patients who normally enjoy outdoor activities, live in a temperate climate, and/or desire to carry out their daily routines, such restrictions may be quite burdensome.
[0040] Therefore, in one embodiment of the invention, a patient who has been administered a photosensitive agent for PDT undergoes plasmaphoresis to remove or decrease the concentration of the photosensitive agent in the circulation. Another benefit of plasmaphoresis is that it reduces excessive cholesterol, low density lipoproteins, and other blood components that might aggravate AMD, therefore plasmaphoresis may be an advantageous treatment to patients with AMD at times other than following PDT.
[0041] Generally, plasmaphoresis involves the withdrawal, purification, and reinfusion of the purified blood back into the patient from whom it was withdrawn. It involves minimal patient discomfort, little patient time (two to three hours), and minimal safety risk, since the patient is reinfused with his or her own blood. The technical aspects of plasmaphoresis are known to one skilled in the art.
[0042] In one embodiment, the patient has an intravenous line in place for administration of the photosensitive agent and undergoes PDT. Thereafter, a second intravenous line is started and the patient undergoes plasmaphoresis; blood is withdrawn from one intravenous line and flows into an apparatus that separates the liquid plasma from the cellular components. The plasma then flows through a separating and/or filtering system, for example, an ion-exchange or other type of resin, that removes undesired substances such as the photosensitive agent. The patient's now filtered plasma is reinfused via the other intravenous line. Plasmaphoresis may be conducted immediately or shortly after PDT. Plasmaphoresis may also be conducted at a later time, such as within twenty-four hours of PDT, during which time the indwelling intravenous line may be left in place with suitable protections, as is known to one skilled in the art.
[0043] Eighteen patients ranging in age from 50-80 years of age, and either previously diagnosed with AMD or with early stage AMD have been treated using the inventive method. All of these patients experienced at least some loss of vision pre-treatment.
[0044] For PDT, verteporfin was the photosensitive agent and was administered intravenously at a dose of 1-2 mg/kg. Verteporfin was activated using a coherent laser with the red beam (krypton) at a wavelength of 640 nm. For laser coagulation therapy, the spot size was 200 μm and the duration was 0.4 seconds. The number of spots applied was between 150 and 350. The interval between PDT and laser coagulation therapy was 5 minutes to 24 hours.
[0045] Improved visual acuity was achieved in fifty percent (9/18) of these patients post-treatment within six to eight weeks post-treatment, as assessed by accurate reading of a standard vision chart. This is a dramatic improvement over the previously described results in patients treated with PDT alone, in which over 60 % of the patients lost some vision but less than 15 letters, 40% of the patients lost more than 15 letters, and only 16% of the patients showed improved vision.
[0046] Of the eighteen patients treated with the inventive method, the vision in the remaining fifty percent (9/18) of the patients remained stable over six to nine months, assessed by no further loss of visual acuity.
[0047] Beneficially, in the entire patient population treated with the inventive method, the incidence of the need for retreatment has been zero. Also advantageously, there have been no cases of laser-induced neovascularizations in patients receiving the inventive treatment.
[0048] The inventive therapy prevents new vessels (subretinal neovascularization) from forming at the site of treatment, which occur when laser coagulation therapy is administered without PDT. The inventive therapy also prevents recurrence of new vessel formation, a problem associated with separate PDT therapy.
[0049] The inventive treatment method has been used successfully to prevent AMD in patients who have diffuse occult lesions (a form of AMD), early stages of AMD (drusen, pigment clumps, etc.), and a combination of pigment with epithelial detachment and neovascular membrane.
[0050] The inventive method thus treats AMD, and further reduces or eliminates the need for retreatment. It also prevents or alleviates onset, and slows the progression, of AMD without inducing further growth of new vessels from the laser treatment itself.
[0051] It should be understood that the embodiments of the present invention shown and described in the specification are only preferred embodiments of the inventor who is skilled in the art and are not limiting in any way. For example, the inventive method may be used in conjunction with administration of other agents such as anti-angiogenic agents (e.g., systemic or intraocular), anti-proliferative agents, and/or with steroids (e.g., subconjunctival depot steroid therapy). Therefore, various changes, modifications or alterations to these embodiments may be made or resorted to without departing from the spirit of the invention and the scope of the following claims. | Age-related macular degeneration (AMD) results in the formation of new blood vessels in the eye. The walls of these vessels leak fluid, which causes scarring in the surrounding tissue, resulting in reduced vision or loss of vision. Photodynamic therapy (PDT) alone has been used to treat AMD, but many retreatments are needed, which cause further damage to the already diseased area. Laser treatment to coagulate the fluid actually causes additional new vessels to form. However, the inventive method of treating patients with both PDT and laser coagulation surprisingly either improved vision, or prevented further loss of vision. Moreover, the combined treatment eliminated the need for retreatment, and did not generate new vessel growth. Laser coagulation and PDT may be administered within the same treatment session or either may be administered first and the other may be administered within ninety days. | 0 |
FIELD OF THE INVENTION
This invention relates to continuous countercurrent devices for the separation of samples, and more particularly to an elution method and apparatus for continuous countercurrent chromatography of the type employing a rotating coiled tube, with gravimetric separation means cooperating with said rotating tube.
BACKGROUND OF THE INVENTION
Various arrangements for countercurrent chromatography have been developed to produce high efficiency solute partitioning in two-phase solvent systems. These systems generally use a stationary phase which is retained in the column while the mobile phase elutes through the system. In these prior systems, since the sample solution is introduced at the beginning of each operation, such systems are regarded as constituting batch separation techniques, and not continuous extraction processes.
However, continuous extraction processes necessitate "genuine" countercurrent flow, wherein two immiscible solvents move in opposite directions with respect to the separation column to allow continuous sample feeding and continuous enrichment and/or stripping of the ingredient or ingredients desired to be collected, present in a large quantity of liquid. Heretofore no satisfactory system for accomplishing this objective has been available.
The following prior U.S. Pat. Nos. illustrate the present state of the art:
Ito et al., 3,775,309
Ito et al., 4,040,742
Ito, 4,051,025
Ito, 4,058,460
SUMMARY OF THE INVENTION
In order to meet the above-described continuous-flow extraction requirement, the present invention employs the "genuine" countercurrent flow of two immiscible solvents through a helical column to achieve high-efficiency continuous solute extraction or partitioning. This extraction scheme will be useful not only in the separation of chemicals in research laboratories, but also in large-scale industrial applications, including reprocessing nuclear fuels and in eliminating hazardous pollutants from industrial waste water.
The principle employed is substantially as follows:
When an end-closed coiled tube containing two immiscible liquids is rotated in an acceleration field acting perpendicular to the axis of the coil, a dynamic equilibrium is established wherein the two liquids occupy approximately equal volumes in each coil unit from one end of the coil (the head end), and any excess of either phase remains at the other end of the coil (the tail end). This dynamic equilibrium of the two phases enables a high efficiency separation of solutes when the mobile phase is eluted through the head end of the coiled tube. Both retention of the stationary phase and thorough mixing of the phases are attained in the coiled tube so as to separate solutes according to their partition coefficients. For example, an efficiency of up to 10,000 theoretical plates has been achieved in the separation of dinitrophenyl amino acids using the flow-through coil planet centrifuge technique.
In order to introduce "genuine" countercurrent flow through this rotating coiled tube, it is further necessary to understand the following physical properties inherent in this dynamic equilibrium of two phases in the rotating coiled tube:
(1) It creates a linear pressure gradient from the head end to the tail end through the coiled tube. The maximum pressure difference P max can be calculated from the equation
P.sub.max = n (ρ.sub.H - ρ.sub.L) g h,
where n denotes the number of coil units; ρ L and ρ H denote the densities of the lighter and heavier phases; g denotes the acceleration; and h denotes the helical diameter. Thus, if the two portions of the coil containing the two phases are connected with a tube, the liquids start to circulate through the newly created loop in a direction from the head to the tail end through the connecting tube.
(2) When any amount of one phase is replaced by the other phase at any portion of the coil containing the two phases, the dynamic equilibrium is quickly reestablished by itself by "genuine" countercurrent flow of the two phases, i.e., forward movement of the former phase and backward movement of the latter phase.
(3) There are two directions for introducing the flow through the entire length of the coiled tube. The head-tail elution with either phase results in retention of the other phase in the coiled tube, as described above. On the other hand, the tail-head elution with either phase elutes out both phases until the entire column space is occupied by the same phase.
Accordingly, a main object of the present invention is to provide an improved countercurrent chromatography system which overcomes the deficiencies and disadvantages of the previously-used systems employed in countercurrent chromatography.
A further object of the invention is to provide a novel and improved system for high-efficiency solute partitioning which employs countercurrent flow wherein two immiscible solvents move in opposite directions with respect to a separation column to allow continuous sample feeding and continuous collection of a desired ingredient or ingredients.
A still further object of the invention is to provide an improved method and apparatus for continuous-flow countercurrent chromatography of the type employing a rotating coiled tube, wherein separation and collection are effected by cooperation of gravimetric separation means with the rotating coiled tube, and wherein the output flow may be selected to be either only the heavier phase or only the lighter phase of a two-phase mixture.
A still further object of the invention is to provide an improved continuous-flow countercurrent chromatography system which utilizes a rotating helical column to separate two phases of different densities and which further utilizes pressure gradients derived from the difference in densities to produce a circulation aiding in the selective output of one or the other of the two phases.
A still further object of the invention is to provide an improved continuous-flow countercurrent chromatography system which employs a rotating helical column in a gravity field to separate two phases of different densities, which collects the two phases in a chamber at the head end of the column, which allows the lighter and heavier phases to become separated in said chamber, and which includes means to elute one or the other of said two phases with high efficiency.
More general objects include providing for improved separation or extraction of components in a liquid; and providing a genuine countercurrent liquid-liquid separation process and apparatus.
BRIEF DESCRIPTION OF THE DRAWINGS
Further objects and advantages of the invention will become apparent from the following description and claims, and from the accompanying drawings, wherein:
FIG. 1 is a diagrammatic representation of a horizontal rotating coiled chromatography tube in a gravitational field, with inlet and outlet flow tube connections for two immiscible phases.
FIG. 2 is a diagrammatic view showing a structural arrangement according to the present invention connected to the head end of the chromatography tube of FIG. 1 for eluting a desired phase.
FIG. 3 is a diagrammatic view similar to FIG. 2 but showing a modification of the structural arrangement.
FIG. 4 is an enlarged vertical cross-sectional view taken longitudinally through the inner end portion of the elution pipe of FIG. 3.
FIG. 5 is a longitudinal cross-sectional view of a further modification of a chromatography column and head end elution arrangement according to the present invention.
FIG. 6 is a diagrammatic view of a further modified structural arrangement according to the present invention, using a shunt and settling chamber outside the rotating part of the chromatography assembly.
DESCRIPTION OF PREFERRED EMBODIMENTS
On the basis of the above-described physical factors, there will now be considered the provision of "genuine" countercurrent flow through the rotating coiled chromatography tube.
Referring to the drawings, FIG. 1 shows a rotating helically coiled tube 11 in an acceleration (gravitation) field g. The coiled tube 11 has two pairs of flow-connecting tubes, I F and I C to respectively feed and collect phase I, and II F and II C to respectively feed and collect phase II, where phases I and II are two immiscible phases in the rotating coiled tube 11. These flow-connecting tubes may be brought outside the rotating parts of the apparatus in a conventional manner with or without the use of rotating seals, as will be presently discussed. The flow-connecting tubes may be provided with suitable control valves 12 to 15, as shown.
The flow-connecting tubes II C and I F are located at the tail end of coiled tube 11 and the flow-connecting tubes II F and I C are located at the head end.
Assume that the rotating coiled tube 11 contains phases I and II in a dynamic equilibrium state, with all valves 12 to 15 closed. It is then possible to introduce phase II through tube II F and collect the same phase through tube II C by opening valves 14 and 12 to establish countercurrent flow of phase II through the coiled tube 11. However, introduction of phase I through tube I F to collect this phase exclusively at I C is difficult because in this situation both phases will be eluted at tube I C . This difficulty can be solved, however, by utilizing one of the following two possible methods:
1. Employ a selecting device at the head of the coiled tube 11 arranged such that only phase I is eluted through tube I C .
2. Take out the mixture of phases I and II in such a way that the flow rate of phase I through tube I C is equal to the feed rate of phase I through tube I F while returning the eluted phase II into the coiled tube 11 through a loop established between tubes I C and II F .
FIGS. 2 to 5 show examples of head end phase-selecting devices utilizing the first of the above two methods.
FIGS. 2 and 3 illustrate the use of a hollow cylinder 16 which is connected to the head end of the coiled tube 11 and is mounted to rotate coaxially therewith, whereby the acceleration g acts perpendicularly to the axis of the cylinder. Two-phase mixture introduced from the head of coiled tube 11 into the cylinder 16 can then be separated by the acceleration field into two phases, the heavier phase being at the bottom and the lighter phase being at the top, with an interface at 17, as shown in FIG. 2. These two phases remain substantially stationary relative to the acceleration field g, while the rotating cylinder moves relative to said two phases. Thus, if the input portion of collection tube I C stays always in the lower part of the cylinder 16, this permits only the heavier phase to be eluted, and if the input portion of collection tube I C stays always in the upper part of said cylinder, this permits only the lighter phase to be eluted through I C .
The phase-selecting device of FIG. 2 comprises a flexible tube 18 extending rotatably and sealingly through the center of the circular end cylinder wall 19 and leading to collecting tube I C . Flexible tube 18 has a weight (or float) 20 secured thereon close to its inner end. If the density of the element 20 is substantially greater than that of the heavier phase, it forces the inner end of tube 18 to be always positioned in the heavier phase, and if the density of element 20 is substantially less than that of the lighter phase, it acts as a float and forces the inner end of flexible tube 20 to stay always in the lighter phase. Thus, by suitable selection of the density of element 20, either the heavier or the lighter phase may be eluted at I C .
FIGS. 3 and 4 show another embodiment similar to FIG. 2 wherein the eluting tube I C comprises a rigid pipe 21 extending rotatably and sealingly through the center of the cylinder end wall 19 and being provided with an end closure cap 22 threadedly engaged on a reduced end portion 23 of the pipe. Said reduced end portion is provided with a plurality of flow holes 24. An annular groove is thus defined between cap 22 and the shoulder 26 adjacent reduced portion 25. A ring member 27 is freely rotatably mounted on the pipe, said ring member having an inner annular retaining rib 28 which engages rotatably in said annular groove. The ring member is provided with a radial outlet tube 29 on which is mounted a weight (or float) 20 similar to that employed in FIG. 2. Thus, the ring member 27 can freely rotate around the pipe 21 as a bearing, while permitting flow from the outlet tube 29 through the perforations 24 in the reduced pipe portion 23. The proper selection of the density of the weight or float element 20 biases the outlet tube 29 downwardly or upwardly in the rotating cylinder 16 to permit elution of the desired phase into collection tube I C .
Another embodiment which is functionally generally similar to that of FIG. 2 is illustrated in FIG. 5, wherein the design of a coiled column with a cylinder is simplified by employing a cylindrical, elongated, precision-bore casing 30 in which is tightly secured a threaded rod 31 which is sufficiently shorter than the length of the casing so as to define a cylindrical space 32 at the head end of the helical column defined by the helical space 33 between the rod 31 and the inside surface of the casing 30. As in FIG. 2, a flexible tube 18 may be employed, extending rotatably and sealingly through the center of end wall 34 of casing 30, with a weight or float 20 secured on its inner end, to define the elution collection conduit I C . Alternatively, the pipe 21, ring 27, radial tube 29, and weight or float 20 of FIGS. 3 and 4 may be employed in the embodiment of FIG. 5.
FIG. 6 shows an embodiment which employs the second of the above-described possible methods, namely, which uses a shunt and settling chamber outside the rotating part. FIG. 6 shows the use of an arrangement which allows continuous countercurrent extraction by employing a shunt S between the flow tubes I C and II F , and including a settling chamber 40. Phase mixture eluted through I C first enters the settling chamber 40, where phase separation takes place in the gravitational field. Phase I (in this case the heavier phase) is removed from the bottom of the settling chamber through a flow regulator 41 at a rate equal to the feed rate of phase I through I F . (If phase I is the lighter phase it is removed from the top portion of the settling chamber rather than from the bottom). Then, in the case illustrated in FIG. 6, phase II (in this case the lighter phase) separated in the chamber 40 spontaneously enters S and II F to return into the coiled tube 11 due to the pressure difference between the points of connection of II F and I C to coiled tube 11, as previously described. Phase II pumped through II F is mixed with the same phase entering through S and then enters the coiled tube 11, where it splits into two streams, one flowing toward the tail of the coiled tube 11 and eluted through II C at the rate equal to the feed rate through II F , and the other flowing toward the head end of the coiled tube 11 to circulate through the loop defined by settling chamber 40 and shunt element S.
In operation of the apparatus, the entire space of the coiled tube 11 is first filled with the extraction phase (phase II). Elimination of air bubbles from the coiled tube 11 can be completed by introducing the solvent from the tail into the rotating coiled tube. After closing the valve 12 at II C , the sample phase (phase I) which contains solute or solutes to be extracted, is introduced through I F , and a flow regulator employed on I C is adjusted to elute the solvent at the same rate. When phase I starts to elute through I C , the extraction phase (phase II) is introduced through II F and the valve 12 on II C is opened to elute the same phase. When the optimal conditions of flow rates and rotational speed are chosen, a steady "genuine" countercurrent flow will soon be attained in the portion of the coiled tube between the inlets of I F and II F .
Applicable flow rates of the two phases depend upon various factors such as:
(1) column factor (internal diameter, helical diameter and length of the tube),
(2) apparatus factor (acceleration field and rotational speed, and
(3) solvent factor (interfacial tension, viscosity, and density difference of the two phases), and should be determined by preliminary experiments.
Rotation of the coiled tube 11 with respect to the gravitational and/or centrifugal acceleration fields may be accomplished by conventional means, for example, as shown in U.S. Pat. Nos. 3,775,309, 4,051,025, and 4,058,460, above cited. All flow tubes of the rotating coiled tube 11 are brought to the outside of the rotary member of the apparatus either with or without the use of rotating seals. U.S. Pat. No. 3,775,309 shows an arrangement providing a rotating centrifugal force field without the use of rotating seals. U.S. Pat. No. 4,051,025 shows an arrangement including a slowly rotating coiled tube in the gravitational field. Although it requires two sets of rotating seals, it can be conveniently and economically adapted for large-scale industrial use. Likewise, the arrangement of U.S. Pat. No. 4,058,460 can utilize both gravitational and centrifugal acceleration field without the use of rotating seals. Therefore, it is suitable for both small-scale laboratory use and large-scale industrial applications.
While certain specific embodiments of continuous countercurrent devices for the separation of samples, using a rotating chromatography column, have been disclosed in the foregoing description, it will be understood that various modifications within the scope of the invention may occur to those skilled in the art. Therefore it is intended that adaptations and modifications should and are intended to be comprehended within the meaning and range of equivalents of the disclosed embodiments. | A continuous extraction system wherein two immiscible solvents move in opposite directions through a rotating helical column. Elution of a desired phase takes place by use of a separation device at the head end which selects either the heavier or the lighter phase. This may consist of a suitably weighted suspended outlet tube in a rotating cylindrical outlet chamber or may consist of a shunt and settling chamber located outside the rotating part; the heavier phase may be removed from the bottom and the lighter phase may be removed from the top. | 2 |
CROSS-REFERENCE TO RELATED APPLICATION
The present application claims priority to U.S. Provisional Patent Application Ser. No. 62/141,615, filed on Apr. 9, 2015, the disclosure of which is hereby incorporated in its entirety at least by reference.
FIELD OF THE INVENTION
This invention relates to steel tubes used in the construction of the frames (stiles and rails) of windows and doors that are provided with a thermal break. In particular the invention relates to a method and system of providing a thermal break in carbon steel or stainless steel tubes, with a wall thickness of between 10 and 16 gauge, used in the construction of windows and doors of any shape, including square, rectangular, round, curved or otherwise complex shapes. The invention also relates to tubes made of other thermally conductive metal, such as aluminum, although it provides especially unexpected good results with steel.
BACKGROUND OF THE INVENTION
The present invention relates to the technical field of fabrication of frames (stiles and rails) of doors and windows using hollow steel tubing, with a wall thickness of between 10 gauge and 16 gauge, where there is a requirement to control thermal conductivity between components inside and outside of a building.
The frames of conventional, thick walled, steel doors and windows are constructed from hollow tubes that may contain insulation within the hollow cavity of the tubing. This insulation controls both radiation and convection across the cavity but does not control conduction of heat through the steel walls of the tubes. Conduction of heat can cause significant energy loss and, in cold climates, doors and window frames can become very cold on the inside, causing problems of condensation and frosting. The present invention provides a means of providing a “thermal break” with an insulating material which separates inside and outside components from direct contact and effectively controls conduction.
Existing approaches teach that we may use two or more tubes separated by an insulating barrier to provide a thermal break. While such an arrangement limits conduction, the contact area is the full width of the tubing, which greatly reduces the effective insulating properties of the thermal break. Such an arrangement also uses much more steel than a conventional construction, increasing both cost and weight. Accordingly, these problems are overcome by the present invention which provides a means of adding a thermal break in thick walled tube construction that adds little weight and which utilizes the thermal properties of the insulating material to the greatest effect.
Although thermal breaks are common in the frames of aluminum windows and doors, the method and means of application requires the use of extruded profiles of aluminum that are not generally available in steel or, if available, would result in a structure far too heavy to be practicable. Some thermal breaks have been made using steel sheeting bent into complex folds that is only possible with steel thinner than 16 gauge. The present invention enables a thermal break to be provided in tubing constructed of carbon or stainless steel of between 10 gauge and 16 gauge.
The folded and extruded profiles currently used to create a thermal break can only be applied to straight sections of doors and windows and not to curved shapes such as a round window or an arched door or window. The present invention allows the thermal break to be utilized in the frames of square, rectangular, curved and or complex shaped doors and windows.
BRIEF SUMMARY
In one embodiment of the present invention, a thermal break system is provided comprising an inside steel panel having an inner surface and an outer surface, and a C-shaped section extending about a periphery thereof with a portion of the C-shaped section extending in part parallel to the inner surface of the inside steel panel; an outside steel panel having an inner surface and an outer surface, and a C-shaped section extending about a periphery thereof with a portion of the C-shaped section extending in part parallel to the inner surface of the outside steel panel; and an insulating material interposed between respective C-shaped sections of the inside steel panel and the outside steel panel to thermally isolate the inside steel panel and the outside steel panel from each other, and said inside steel panel and outside steel panel being secured together at respective C-shaped sections to form the thermal break system.
In one embodiment the inside and outside steel panel has a thickness of 10 gauge to 16 gauge. In another embodiment, the system is a window. In yet another embodiment, the system is a door. In one embodiment, the door is an arched door comprising a first upright stile, a second upright stile, and a curved rail.
In another aspect to the invention, a door is provided comprising an inside metal panel having an inner surface and an outer surface, and a C-shaped section extending about a periphery thereof with a portion of the C-shaped section extending in part parallel to the inner surface of the inside metal panel; an outside metal panel having an inner surface and an outer surface, and a C-shaped section extending about a periphery thereof with a portion of the C-shaped section extending in part parallel to the inner surface of the outside metal panel; and an insulating material interposed between respective C-shaped sections of the inside metal panel and the outside metal panel to thermally isolate the inside metal panel and the outside metal panel from each other, and said inside metal panel and outside metal panel being secured together at respective C-shaped sections to form the door. In another embodiment, the metal is aluminum.
In yet another aspect to the invention a tube assembly is provided comprising a first side having a first inner surface, a first outer surface, a first edge, and a second edge, the distance between the first edge and second edge defining a first width; a first panel located at the first edge extending perpendicularly from the first inner surface at a first depth; a second panel located at the second edge extending perpendicularly from the first inner surface at a second depth; a first land perpendicularly connected to the first panel extending parallel to the first inner surface, the first land having a first length; a second land perpendicularly connected to the second panel extending parallel to the first inner surface, the second land having a second length; a second side having a second inner surface, a second outer surface, a third edge, and a fourth edge, the distance between the third edge and fourth edge defining a second width; a third panel located at the third edge extending perpendicularly from the second inner surface at a third depth; a fourth panel located at the fourth edge extending perpendicularly from the second inner surface at a fourth depth; a third land perpendicularly connected to the third panel extending parallel to the second inner surface, the third land having a third length; a fourth land perpendicularly connected to the fourth panel extending parallel to the second inner surface, the fourth land having a fourth length; a first thermal break having a third width positioned between the first and third land; a second thermal break having a fourth width positioned between the second and fourth land; the first width and the second width being identical; the first length, third length, and third width being identical; and the second length, the fourth length, and the fourth width being identical.
In one embodiment, the first outer surface is exposed to environmental conditions and the second outer surface faces the interior of a building. In one embodiment, the first side comprising a first section, second section, and third section; and the second side comprising a fourth section, fifth selection, and sixth section; the first, third, fourth, and sixth sections consisting of upright stiles; the second and fifth section consisting of a curved rail. In another embodiment, the first and second sides joined to make an arched door. In one embodiment, the first and second sides joined to make an arched window. In yet another embodiment, a plurality of temporary access holes designed to allow access to a plurality of assembly screws is provided, the plurality of assembly screws joining the first land, third land, and first thermal break together and the second land, the fourth land, and the second thermal break together, the plurality of assembly screws being self-drilling and self-tapping. In one embodiment, the tube assembly of claim 8 , further comprising adhesive means between the first land, third land, and first thermal break, and the second land, the fourth land, and the second thermal break.
BRIEF DESCRIPTION OF THE DRAWINGS
Having briefly described the invention the same, will become better understood from the appended drawings, wherein:
FIG. 1 is an exploded cross section view of a thermal break created in a straight tube assembly.
FIG. 2 is a cross-section view of a tube after construction shown with two sides connected through an insulating strip.
FIG. 3 is a partial top section view of an arched door constructed according to the invention.
FIG. 4 is an exploded view of the door of FIG. 3 showing the components thereof.
FIG. 5 is a perspective view of a pair of doors constructed according to the invention.
DESCRIPTION OF PREFERRED EMBODIMENT
The present invention provides a thermal break for the frames (stiles and rails) of square, rectangular, curved and or complex shaped doors and windows made from carbon or stainless steel of between 10 gauge and 16 gauge. A tube is constructed comprising two “C” shaped profiles of steel with two strips of a suitable insulating material sandwiched between them. A suitable insulation material may be, for example Acrylonitrile Butadiene Styrene (ABS) or Polystyrene. In order to provide sufficient mechanical strength, an adhesive bonding agent and a plurality of metal screws are used join the components where they meet.
The final assembly becomes a single hollow tube with one side effectively separated from the other so as to control the conduction of heat around the wall of the tube. This tube can be further filled with insulating foam so that radiation and convection within the tube is also controlled.
The process of manufacture is able to be applied to straight tubes, tubes of any degree of curvature and complex shapes that are combinations of straights and curves. In this manner windows and doors of any size and shape may be provided with the thermal break.
In an alternative aspect, the present invention provides a thermal break for the frames (stiles and rails) of square, rectangular, curved and or complex shaped doors and windows made from thermally conductive metal, such as aluminum. A tube is constructed comprising two “C” shaped profiles of steel with two strips of a suitable insulating material sandwiched between them. A suitable insulation material may be, for example Acrylonitrile Butadiene Styrene (ABS) or Polystyrene. In order to provide sufficient mechanical strength, an adhesive bonding agent and a plurality of metal screws are used join the components where they meet.
FIG. 1 is an exploded cross section view of a thermal break created in a straight tube assembly. Referring now to FIG. 1 , a tube is constructed using two sides, 1 and 2 , made in a “C” profile with a width 3 essentially identical. One tube 1 is made up of an outer surface and an inner surface of an outside steel panel, for example, making up the surface of a door facing the exterior. The outer surface thereof faces the exterior of a building. The inner surface faces the tube 2 making up the panel facing the interior of a building. With respect to tube 2 , its inner surface faces the inner surface of tube 1 , and its outer surface faces the interior of a building when assembled. Depth 4 and 5 of said sides may be dissimilar and does not affect the function of the invention. The sides terminate with lands 6 and 7 having a width which is less than 50% of the width 3 of profiles 1 and 2 , determined by the strength requirement of the particular application. Insulating strips 8 , with a width approximately the same as lands 6 and a depth sufficient to provide the degree of insulation required, are sandwiched between profiles 1 and 2 , coincident with lands 6 and 7 . The assembly is joined using a plurality of self-drilling, self-tapping screws 9 in combination with an adhesive means applied to adjacent faces of lands 6 and 7 , and insulating strips 8 . Screws 9 , having an insulating washer means 11 under the screw head, pass through temporary access holes 10 , whose diameter is sufficient to allow washer means 11 to easily pass. Typical adhesives useful for the invention include Liquid Nails, Bostick, Dap or Tightbond. Alternative screw arrangements may be self-tapping but not self-drilling, in which case suitable pilot holes may be pre-drilled in lands 6 and 7 , as well as insulating strips 8 along an axis coincident with access holes 10 .
FIG. 2 is a cross-section view of a tube after construction shown with two sides connected through an insulating strip. FIG. 2 shows a cross section of the tube after construction where the sides 1 and 2 are connected with insulating strips 8 , typically made of ABS, sandwiched between them. The adjoining faces of lands are connected using a suitable adhesive medium and/or a mechanical connection using a plurality of screws 9 with insulated washer means 11 to connect lands 6 and 7 , passing through insulating strips 8 . Access holes 10 are not shown since they have been closed with electric arc welding.
FIG. 3 is a partial top section view of an arched door constructed according to the invention. Referring now to FIG. 3 a top section of an arched door frame is shown, which has been constructed using the same method as shown for the embodiment in FIG. 1 and FIG. 2 . However, in this case the assembly comprises two upright stiles 31 and 32 and a curved rail 33 . The method of construction is essentially similar to that shown in FIG. 1 and FIG. 2 .
FIG. 4 shows the components of the same section of door shown in FIG. 3 but prior to assembly. Side 1 and side 2 are each comprised of three “C” sections of steel. Side 1 comprises upright stiles 41 and 42 , plus a curved rail 43 . Side 2 comprises upright stiles 44 and 45 , plus a curved rail 46 . Upright stiles 42 , 42 , 44 and 45 have been made by bending sheet steel in a press break. Curved rails 43 and 46 have been fabricated out of sheet steel by cutting the curved shapes that are required in the vertical plane and cutting and bending the shapes needed in the horizontal plain. These components are then welded together to form the curved “C” sections. Specifically, upright stiles 41 and 42 are welded to curved rail 43 to form side 1 of the assembly. Similarly, curved rail 46 and upright stiles 44 and 45 are welded together to form side 2 . Side 1 and 2 include lands (a), (b), (c), and (d). Insulating strips 48 and 49 comprising sections (e), (f), (g), (h), (i), and (j) are cut from sheet material to a size and shape coincident with lands (a), (b), (c), and (d) of sides 1 and 2 . A plurality of temporary access holes 47 are drilled into side 2 so as to facilitate assembly with adhesive and screws the same as shown in FIGS. 1 and 2 . These access holes will be welded closed after assembly.
FIG. 5 is a perspective view of a pair of doors constructed according to the invention. Referring now to FIG. 5 , a pair of typical steel door slabs constructed using the system method of the present invention is shown. Door 1 and Door 2 are essentially identical to each other but mirrored. Each one is comprised of two upright stiles 51 and 22 , two curved rails 53 and 54 and one straight rail 55 . Side 56 of doors is separated from side 57 by thermal break 58 .
The advantages of the present invention include, without limitation, that it is highly efficient at controlling heat conduction from one side to the other. For example, door slabs of FIG. 5 being 100″ high and 76″ wide, a typical size for a double entry door, if constructed of 14 gauge steel would have a conductive transfer area of 117 square inches. The door slabs constructed using the present invention, utilizing 80 of 3 mm diameter screws to attach side 56 and side 57 across thermal break 58 has a conductive transfer area of 5.8 square inches or less than 5% of the conductive transfer area of the conventional door slab construction. The present invention is also light weight, using approximately 30% less steel than the prior method of sandwiching a thermal break between two tubes. The present invention also provides a tubular structure with a single cavity that can be filled with a suitable foam insulation material in order to further improve efficiency by controlling convection and radiation within the tubes. The present invention also utilizes conventional material and manufacturing equipment commonly found in metal factories, i.e., folding, drilling, welding and screwing together of steel. The present invention can be applied to produce insulated tubular doors and windows of curved and complex shapes in addition to conventional square and rectangular doors and windows.
While the invention has been described specifically as being implemented with steel, it will be appreciated that structures such as doors or windows made with other metals which are thermally conductive, such as aluminum, will benefit from the use of the invention even though perhaps not as much as in the case of steel.
It should further be noted that throughout the entire disclosure, the labels such as left, right, front, back, top, bottom, forward, reverse, clockwise, counter clockwise, up, down, or other similar terms such as upper, lower, aft, fore, vertical, horizontal, oblique, proximal, distal, parallel, perpendicular, transverse, longitudinal, etc. have been used for convenience purposes only and are not intended to imply any particular fixed direction or orientation. Instead, they are used to reflect relative locations and/or directions/orientations between various portions of an object.
In addition, reference to “first,” “second,” “third,” and etc. members throughout the disclosure (and in particular, claims) are not used to show a serial or numerical limitation but instead are used to distinguish or identify the various members of the group.
In addition, any element in a claim that does not explicitly state “means for” performing a specified function, or “step for” performing a specific function, is not to be interpreted as a “means” or “step” clause as specified in 35 U.S.C. Section 112, Paragraph 6. In particular, the use of “step of,” “act of,” “operation of,” or “operational act of” in the claims herein is not intended to invoke the provisions of 35 U.S.C. 112, Paragraph 6.
While the foregoing written description of the invention enables one of ordinary skill to make and use what is considered presently to be the best mode thereof, those of ordinary skill will understand and appreciate the existence of variations, combinations, and equivalents of the specific embodiment, method, and examples herein. The invention should therefore not be limited by the above described embodiment, method, and examples, but by all embodiments and methods within the scope and spirit of the invention as claimed. | A thermal break system, comprising an inside steel panel having an inner surface and an outer surface, and a C-shaped section extending about a periphery thereof with a portion of the C-shaped section extending in part parallel to the inner surface of the inside steel panel; an outside steel panel having an inner surface and an outer surface, and a C-shaped section extending about a periphery thereof with a portion of the C-shaped section extending in part parallel to the inner surface of the outside steel panel; and an insulating material interposed between respective C-shaped sections of the inside steel panel and the outside steel panel to thermally isolate the inside steel panel and the outside steel panel from each other, and said inside steel panel and outside steel panel being secured together at respective C-shaped sections to form the thermal break system. | 4 |
BACKGROUND OF THE INVENTION
The invention relates to an electric two-motor drive, each motor of which being connected to a single-phase a-c line which serves as the sole supply source.
There is provided a stator winding, arranged on a common stator lamination core, of a commutator motor having a relatively small number of poles and of an induction motor having a relatively large number of poles. There is provided a common armature which is wound in such a manner that the coils in each phase winding can form short circuits corresponding to the number of poles in the exciting induction motor stator field and that the coils, when functionally connected to input brushes via a commutator, can form circuits having a number of poles corresponding to the number of poles in the commutator stator fields.
DESCRIPTION OF PRIOR ART
In one known two-motor drive of this type (German Offenlegungsschrift No. 25 30 294), the stator lamination core has slots distributed over the entire circumference. The 12-pole, 3-phase stator winding of the induction motor and the windings of the 2-pole commutator motor, functioning as an a-c series motor, are arranged in common slots, with stator laminations being cut with unequal slot cross sections and with the windings of the induction motor being distributed uniformly in all slots. The windings of the series motor are carried by only some of the slots, which slots must therefore have a larger slot cross section than the other slots which carry the winding of the induction motor alone. The rotor carries a 2-pole armature winding connected to the commutator segments of a series motor and also carries an induction motor winding, which is completely separated and is wound having 2 phase windings and with a number of poles corresponding to the induction motor winding of the stator. The coils or groups of coils of the induction motor winding are connected in series, and form short circuits with one end of the winding being connected to the other.
In another known two-motor drive which is shown in Swiss Patent No. 17 611, there is disclosed a d-c motor and an a-c motor having an induction motor winding connected to the commutator and having a d-c wave winding. This drive system, which is used primarily as a rotary converter, is always operated simultaneously with both a-c and d-c current.
SUMMARY OF THE INVENTION
It is an object of the present invention to provide an electric two-motor drive arrangement which makes possible a more effective and efficient utilization of the winding copper used in the rotor with this utilization being simple and effective in terms of production efficiency and winding technique.
According to the teachings of this invention, there is provided an electric two-motor drive wherein the stator and the rotor windings are established having multiple poles and phase windings. A lap winding is connected to a commutator in order to establish a winding system which, at least in regard to a single rotor phase winding, will be functionally operable in commutator as well as induction motor operation. The coil span of this lap winding corresponds approximately to one pole pitch of the low pole, i.e. the 2-pole, commutator stator winding and corresponds to an uneven integral multiple of the multi-pole induction motor stator winding. One thereby obtains the result that, by virtue of simple design of the rotor winding as well as of the commutator, the copper of the winding of the one rotor phase winding used for commutator as well as induction motor operation is fully utilized in each of the two modes of operation (commutator and induction motor, respectively) of the two-motor drive, without the use of any switching. By arranging the rotor winding in a particular manner as taught by this invention, one obtains the result that, on the one hand, all phase windings respond to the multi-pole stator field of the induction motor as multi-phase windings formed by short circuited phase windings, and, on the other hand, if current flows through the brushes of the commutator and the stator winding of the commutator motor is thereby energized, the phase winding functions in conjunction with the 2-pole field as a normal commutator lap winding. This functioning as a normal commutator lap winding takes place without the occurrence of oversynchronous braking torques at speeds above the synchronous speed of the multi-pole induction motor caused by the rotor phase windings, since the voltages formed in low (e.g. 2) pole operation by the low-pole field in the above-described "multi-pole shorted circuits" add up to zero.
A particularly advantageous application of the two-motor drive constructed in accordance with the invention would be in automatic washing machine drives, in which the induction motor would be functional for the washing cycle and the commutator motor, as a series universal motor, for the spinning cycle. Due to the specific design and stress conditions during the spinning operation, i.e., during the universal motor operation, not all the copper of the rotor need be used.
The induction motor or the commutator motor of the two-motor drive according to the invention can be made predominant: there can be provided, according to further embodiments of the invention, at least one additional rotor phase winding which would be arranged in a known manner as an induction motor winding isolated from the commutator winding and the commutator. The coils or groups of coils of this winding are connected in series in each phase winding and the beginning of the series circuit is connected directly to its end. There can also be provided a two-loop lap winding arrangement connected to a commutator providing a common winding system for at least two rotor phase windings. There is also disclosed an electric two-motor drive which possesses advantages vis-a-vis the two-loop lap winding, particularly in regard to the problems of circulating currents and uneven segment voltages. This latter drive is arranged so as to provide a common winding system for at least two rotor phase windings: there are provided two commutators, each of the communtators having connected thereto a single loop lap winding with the brush systems for the two commutators being connected in series.
Further features and advantages will be set forth in connection with the following detailed description.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 shows the basic prior art circuit for an automatic washing machine drive having a three-phase induction motor and a universal motor (commutator) arranged on the same lamination core,
FIG. 2 shows a prior art winding diagram for the stator winding of a 12-pole, 3-phase winding induction motor and a 2-pole universal (commutator) motor arranged on the same stator lamination core,
FIG. 3 shows a first phase winding of a partially integrated rotor winding which is used only for induction motor operation and which has no connection to the commutator,
FIGS. 4 and 5 show a second phase winding which is connected to a commutator and is functional during both induction motor operation as well as during commutator motor operation, FIG. 4 depicting the winding when used for induction motor operation and FIG. 5 depicting the winding during universal motor operation with power supplied via brushes and commutator,
FIG. 6 depicts the winding scheme of a fully integrated phase winding which is functional in both low pole (e.g. 2 pole) commutator operation as well as high pole (e.g. 12 pole) induction operation,
FIG. 7 depicts the winding plan shown in FIG. 6 with an additional fully integrated phase winding for induction motor operation, which arrangement utilizes only one commutator, and
FIG. 8 depicts a fully integrated rotor winding with two phase windings for induction motor operation, which arrangement utilizes two commutators.
DETAILED DESCRIPTION
FIG. 1 shows in a dashed-dotted frame the integrated induction and universal motor to which electrical power is supplied via a single-phase line R, M p . The three phase windings of the Y or star connected stator winding are shown at U12-X12, V12-Y12, and W12-Z12. The field winding of the series universal motor 2 is shown at EF and is supplied via single-phase a-c line R,M p ; the brushes of associated rotor 21 are at BA. FIG. 1 shows reversing switch 3 having contacts 31 and 32 connected in parallel to inputs V12 and W12; as is seen in the figure, switch 3 is also connected to terminal R of the supplying single phase line R,M p and capacitor C is shunted across the reversing switch terminals 31, 32. Thermal monitor 4 is connected between the second terminal M p of the single-phase supply line R,M p and the input terminal U12 of the induction motor. The induction motor which can, for example, be used to drive the washing drum of an automatic washing machine, could be provided with 12 poles and with the utilization of a reduction belt drive would be able to rotate the drum of the washing machine at approximately 50 RPM's. The induction motor can also be provided with only two phase windings instead of the three phase windings shown in FIG. 1. According to a preferred embodiment the universal motor has two poles, although a different number of poles could be selected.
The number of poles of the universal motor should, however, differ from the number of poles of the induction motor since, by virtue of this difference, one obtains, without additional switching and interrupting means in the current supply to the induction motor, no overall oversynchronous braking torque of the induction motor when the commutator series motor is operated at a speed above the synchronous speed of the induction motor.
The upper portion of FIG. 2 depicts the winding plan of the prior art induction stator winding, generally shown in FIG. 1. The upper portion of FIG. 2 shows the core of a 12-pole, 3-phase winding induction motor 1 while the lower portion of FIG. 2 shows the winding plan of the stator of the 2-pole universal motor arranged on the same lamination core; the winding as shown in FIG. 2 consisting of these two winding configurations would be appropriate for the stator of a motor constructed according to the teachings of this invention.
FIG. 3 shows a first phase winding, which is not connected to the commutator, of a rotor winding having 2 phase windings which function in induction motor operation; the second phase winding of this rotor winding is shown in FIG. 4 with the brushes carrying no current for induction motor operation while FIG. 5 shows the brushes carrying current for low-pole (i.e. 2 pole) commutator operation. As seen in these Figures the rotor has 24 rotor slots with the commutator being provided with 24 segments to which are connected the winding as per FIGS. 4 and 5 in accordance with the teachings of the invention.
FIG. 3 shows the first phase winding which constitutes a 12-pole short-circuit winding having a coil span of 5τ p , this arrangement being functional only in induction motor operation. The current arrows shown indicate 12-pole rotor excitation.
FIG. 4 shows a second phase winding having the same coil span as the first phase winding shown in FIG. 3 with the coils in FIG. 4 being subdivided into subcoils and connected to a 24 segment commutator. This phase winding will be functional in induction motor operation as the normal short circuited rotor winding which will be energized by the 12 pole induction motor stator winding. The arrows shown in FIG. 4 indicate the direction of current induced in the winding during normal induction motor operation. It will be noted that, although the winding is connected to commutator segments (1, 3, . . . 23), this does not effect the winding operation as the input brushes normally connected to the commutator segments carry no current in FIG. 4, and, accordingly, the winding will, as mentioned, function as a normal induction motor secondary or rotor winding excited by the 12 pole induction motor primary or stator. Since, as mentioned, the brushes which are associated with the commutator of FIG. 4 do not function in the induction motor operation depicted in FIG. 4, these brushes are not shown in the figure.
FIG. 5 shows the same phase winding as FIG. 4 with FIG. 5 depicting the situation when the winding is energized via the brushes indicated in the figure and functioning as the rotor winding in a 2-pole universal motor. Again, the arrows superimposed on the windings show the direction of current flow during normal 2-pole universal motor operation.
FIG. 6 depicts a fully integrated phase winding for a 2 or 12 pole selectable drive motor having 24 slots (only 5 commutator segments are shown for ease of understanding). The winding shown in FIG. 6 will function as either a 2-pole commutator winding, which is closed upon itself, in normal fashion, or as a short-circuited 12 pole multiphase induction motor winding. In FIG. 6 the arrows indicate the two possible current flows in the winding, the upper arrows indicate current flow in two pole universal motor operation with the winding energized via the commutator and the lower arrows indicate current flow in 12 pole induction motor operation. This depicted winding is able to function in commutator motor operation or in induction motor operation by virtue of proper choice of slot number and coil span. The coil span is shorter than the pole pitch of the 2-pole system by a factor of approximately 1/6.
Although FIG. 6 shows but a single short circuited phase winding for induction motor operation, for optimum functioning, at least two such short circuited independent windings should be utilized.
One possible manner of combining two phase winding in a fully integrated rotor winding is shown in FIG. 7. Two windings such as seen in FIG. 6 are located jointly on the rotor in order to show the fully integrated winding part and are alternately connected to the 12 commutator segments of the commutator as shown. A rotor provided with such a winding can function either as a 2-pole commutator armature with 4 parallel winding branches or as a 12-pole short-circuited induction rotor having 2 winding phases. This armature would be fully functional in commutator as well as in induction motor operation even without an additional isolated phase winding not connected to the commutator.
FIG. 8 also shows two fully integrated phase windings which are connected to two different commutators (segments 1, 3, 5, 7, 9, 11 and 2, 4, 6, 8, 10, 12 respectively). As in FIG. 7, one phase winding is shown with solid lines and the second phase winding with dashed lines. In the two commutator winding plans shown in FIG. 8, the brush systems are connected in series and only two parallel branches are provided in the armature. In the embodiments of the windings shown in FIGS. 6 to 8, as in the embodiments of FIGS. 3, 4 and 5, the coil span of the winding is such as to correspond to an uneven multiple of a conventional asynchronous-motor winding. In regard to the partially integrated rotor winding as shown in FIGS. 3 to 5, it has been noted that the costs for the fabrication of the winding as well as for the commutator can be kept relatively low.
The coil span for the non-integrated phase winding shown in FIG. 3 can be set at 5τ p of the high pole machine. In this case, this winding can be located, similar to a 2-pole universal motor winding, as a diametral winding, into the slots by machine means, for example, by means of a so-called flyer. However, to obtain particularly short winding lengths, a pole pitch can be chosen which deviates upward or downward and so long as it meets the requirement as corresponding to an uneven multiple of the pole pitch of the multi-pole winding.
The basic principle is that, for the integrated winding, on the one hand, the coil span is to correspond to an uneven multiple of the multi-pole "asynchronous" winding and on the other hand, this span is to correspond as nearly as possible to the pole pitch (1τ p ) of the low-pole (i.e. 2-pole) commutator motor winding in order to obtain a good winding factor.
Regarding the displacement in space of the series-connected coils of a phase winding and the phase windings relative to each other, the following applies for the integrated rotor windings:
The series-connected coils are spatially displaced relative to each other by an even multiple of the pole pitch of "asynchronous" machine operation. The winding consists of m parts which are closed on themselves and are displaced at the rotor circumference by the spatial angle 2π/2p A M (p A =number of pole pairs of the "asynchronous" machine operation). | An induction and universal (commutator) motor combination which share a common lamination core and are supplied by a single-phase line. The stator and rotor are provided with multiple poles and phase windings. A winding system for at least one rotor phase winding is common to commutator motor as well as induction motor operation. A lap winding is connected to a commutator, said lap winding having a coil span corresponding approximately to a single pole pitch of the commutator motor stator winding and corresponding as well to an uneven integral multiple of the coil span of the multi-pole induction motor stator winding. The invention finds particular application in regard to drives for automatic washing machines. | 3 |
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application claims the priority benefit under 35 U.S.C. §119(e) of U.S. Provisional Application Ser. No. 61/256,921, entitled “ENHANCED GENE EXPRESSION IN ALGAE” filed Oct. 30, 2010, which is incorporated herein by reference in its entirety.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] This invention relates to the field of molecular biology and in particular to the expression of transgenes in algae.
[0004] 2. Description of the Background
[0005] Transgenes are foreign DNA sequences introduced into genomes, in the case of eukaryotic cells within the chromosomes. These genes are usually transcribed as any other gene of the host. Transcription is generally controlled by the chromatin structure that packs the chromosome's DNA into tight bundles in eukaryotic organisms called nucleosomes. As the chromatin structure around a specific gene relaxes, the DNA of the particular gene becomes accessible to the transcription machinery of the cell. Staining indicates that actively transcribed genes in eukaryotes are more loosely incorporated in nucleosomes and more prevalent in euchromatin. In some instances, transgenes are incorporated into the host's chromosome but fail to be expressed due to unfavorable chromatin structures. This phenomenon is called “gene silencing.” The ability to control how tightly a nucleosome is packed can help enhance the expression of transgenes in host cells. In mammalian cells, it has been proposed that coupling transgene expression with increased availability of a histone “tail” modifying gene, p300 (also known as a histone acetyl transferase, or “HAT”; in the family of CREB binding proteins, or “CBP”), can increase the expression level, presumably because the acetyl transferase activity causes a looser histone-DNA association and allows transcription factors access to the genes. T. H. J. Kwaks et al., J. Biotechnology, 115:35-46 (2005).
[0006] Microalgae encompass a broad range of organisms, mostly unicellular aquatic organisms. The unicellular eukaryotic microalgae (including green algae, diatoms, and brown algae) are photosynthetic and have a nucleus, mitochondria and chloroplasts. The chromatin structure in algae is distinct from other eukaryotes. The chromatin in algae stains heavily, indicating a more compact nucleosome structure and tight association of the DNA to the histones. These differences in chromatin structure of microalgae, particularly in green algae, suggest distinct mechanism of histone chromatin regulation of gene expression.
[0007] These differences in eukaryotic microalgae chromatin structure may be the factor behind the observation that stable nuclear transgene expression in microalgae is difficult and transient due to chromatin mediated gene silencing. H. Cerutti, A. M. J., N. W. Gillham, J. E. Boynton, Epigenetic silencing of a foreign gene in nuclear transformants of Chlamydomonas , The Plant Cell 9:925-945 (1997). When genetic constructs comprising a mammalian derived anti-apoptotic gene and a fluorescent reporter gene were previously introduced by the present inventors in algae, the expression levels were low and no expression of the fluorescence gene was detected, thus confirming that transgenes are difficult to express in algae.
[0008] Algae are considered an important source of healthy nutrients for human consumption and are important as biomass and biofuels. Genetic engineering and stable (over multiple generations) expression of transgenes would open new horizons and greatly enhance the value and desirability to beneficially culture algae. However, as noted above, stable and sufficiently high level of gene expression has been difficult to achieve. A method to improve transgene expression in algae and make that expression stable would be very useful. Such an approach would need to account for the uniquely robust histone mediated gene silencing of microalgae including green algae.
SUMMARY OF THE INVENTION
[0009] In accordance to one embodiment, the invention provides a system for enhanced gene expression in algae, the system comprising:
[0010] an algae compatible transcriptional promoter functionally upstream of a coding sequence for a gene expression enhancer (GEE) fusion protein, wherein the fusion protein comprises an algae derived p300 functionally fused to the DNA binding protein, wherein at least the portion of the coding sequence of the DNA binding protein domain is codon optimized for improved expression in an algae;
[0011] at least one transgene functionally downstream of an algae compatible transcriptional promoter; and
[0012] at least one DNA region that is a binding site for the DNA binding protein, in vicinity of at least one of said transcriptional promoters;
[0013] wherein said system resides in an algae.
[0014] In a preferred embodiment, the DNA binding protein is LexA DNA Binding domain. In another preferred embodiment, the p300 part of the GEE fusion protein is from Chlamydomonas reinhardtii . In a more preferred embodiment, only a HAT domain of the p300 protein is part of the GEE fusion protein. The p300 or only the HAT domain of p300 may be derived from homologs of other microalgae including green algae in addition to Chlamydomonas reinhardtii.
[0015] In accordance to another embodiment, the transgene is codon modified for improved expression in algae. In a preferred embodiment, the transgene or gene of interest (GOI) is a fluorescence-Bcl-x L fusion gene. The fusion protein may include a fluorescence-Bcl-x L construct (e.g. YFP-Bcl-x L fusion or a Venus-Bcl-x L fusion). In another preferred embodiment, the transgene is the YFP/Venus gene, not necessarily part of a fusion protein. Venus is an enhanced yellow fluorescent protein (YFP) that is stable over a wide range of pH, folds quickly, and emits at 30-fold the intensity of conventional YFP. Nagai T., Ibata K., Park E. S., Kubota M., Mikoshiba K. and Miyawaki A. (2002). A variant of yellow fluorescent protein with fast and efficient maturation for cell-biological applications. Nature Biotechnol, 20, 87-90.
[0016] In accordance to another embodiment, the system further comprises at least one selective marker such as an antibiotic resistance marker. In a preferred embodiment, the GEE fusion protein and the at least one transgene are introduced into the system on one vector and structurally arranged to be expressed from one bidirectional promoter region and comprising DNA binding sites in the vicinity of both promoters. In a more preferred embodiment, the GEE fusion protein and the transgene are introduced in the system on separate vectors, each comprising a selective marker and the selective markers are not the same. When separate vectors, both the GEE vector and the vector for the gene of interest (GOI) will contain selective markers. When the GEE is introduced on a separate vector from the vector for the GOI, the GEE vector may be used to generate a stable algae cell line that will serve as the recipient for the second vector expressing the GOI. This stable GEE algae cell line will function to enhance the expression of the second vector containing the GOI.
[0017] In accordance to yet another embodiment, the algae compatible transcriptional promoters are hsp70, rbcS, nitA, actin, tubA2 or a combination thereof.
[0018] In accordance to another yet embodiment, the GEE fusion protein comprises a DNA binding domain functionally fused to an algae derived p300 homologue having at least 80% identity over the HAT region to the p300 from Chlamydomonas reinhardtii . Preferably, the GEE fusion protein comprises a DNA binding domain functionally fused to the HAT domain of the HAT region to the p300 from Chlamydomonas reinhardtii . It is noteworthy that the p300 from mammalian species is much larger in size and is much less that 50% similar to Chlamydomonas reinhardtii p300.
[0019] The invention also provides a method of expressing a gene in algae at higher levels, comprising:
[0020] transforming algae with at least one vector comprising:
[0000] an algae compatible transcriptional promoter functionally upstream of a coding sequence for a gene expression enhancer (GEE) fusion protein, wherein the fusion protein comprises an algae derived p300 functionally fused to the DNA binding protein, wherein at least the portion of the coding sequence of the DNA binding protein domain is codon optimized for improved expression in an algae;
[0021] at least one transgene functionally downstream of an algae compatible transcriptional promoter; and
[0022] at least one DNA region that is a binding site for the DNA binding protein, in vicinity of at least one of said transcriptional promoters;
[0023] selecting a transformed algae cell; and
[0024] detecting the expression of said GEE gene and/or said transgene in algae.
[0025] In a preferred embodiment, the DNA Binding protein is the LexA binding domain, and more preferably the p300 is from Chlamydomonas reinhardtii . More preferably yet, the GEE fusion protein comprises the LexA binding domain functionally fused with the HAT domain of the p300 protein from Chlamydomonas reinhardtii.
[0026] In accordance to another embodiment, the transgene is a YFP-Bcl-x L fusion protein or a Venus-Bcl-x L fusion protein.
[0027] In accordance to yet another embodiment, the GEE fusion protein and said transgene are transformed in algae on separate vectors, first selecting a vector stably expressing the GEE fusion protein and then transforming the selected algae with the vector comprising the transgene.
BRIEF DESCRIPTION OF THE DRAWINGS
[0028] FIG. 1 illustrates the features of a vector in accordance to one embodiment of the present invention. The direction of transcription is indicated by arrows. The figure indicates certain structural components, as discussed herein elsewhere. The linear drawing provides further details of the respective region of the vector: a fused LexA-p300 protein coding region and a coding region of a GOI. In this embodiment, these two coding regions are transcribed in opposite directions (thus the “bidirectional” nomenclature). These two coding regions are separated by a locus comprising LexA binding sites.
[0029] FIGS. 2A and 2B illustrate another embodiment of the invention. FIG. 2A is a vector expressing a LexA-p300 fusion protein. FIG. 2B illustrates a vector expressing another gene which is advantageously introduced in algae (“gene of interest or “GOI”). In accordance to this embodiment, each of the LexA-p300 fusion and the GOI have, at or near their 5′-ends, LexA binding site(s).
[0030] FIG. 3 compares the putative p300 protein from algae ( Chlamydomonas reinhardtii (“Chlamy”) with known p300 proteins from the indicated phylogenetically representative species. The lighter colored section of each bar represents the histone acetylase (HAT) domain. The HAT domains are aligned for visualization purposes. These lighter bars include numbers that are indicative of the percent identity of the HAT domain of each protein proteins within each panel, with the indicated percentages of identity of each HAT protein to the p300 HAT domain of the p300 protein from Chlamy. The figure is drawn to scale, both in respect to the overall size of the p300 proteins and the location of the HAT domain within the protein.
DETAILED DESCRIPTION
[0031] Expression of transgenes in the algae is difficult. H. Cerutti, A. M. J. et al., The Plant Cell 9:925-945 (1997). Likewise, when the present inventors transformed a microalgae with a construct expressing a yellow florescence protein (“YFP”) fused to a cancer suppressing Bcl-x L gene (the transcription driven by the rubisco promoter (rcbS2) and relying on a heat shock translational enhancer (HSP70)), the transformed microalgae failed to produce fluorescence. However, transformants which survived marginally longer and were morphological affected (the result of limited expression of the Bcl-x L gene) were observed. It is expected that that gene silencing contributed to the poor expression of the transgenes in algae.
[0032] The present invention provides an effective method to increase transgene expression in algae, preferably a green algae, more preferably a microalgae. A preferred algae of the invention is an unicellular, photosynthetic algae. A yet more preferred algae is the microalgae. The GOI transgene expressed in the algae in accordance to the invention is expressed to a higher level. The expression is increased by at least 50%, preferably about two to at least five fold, relative to the expression of the same transgene engineered in the algae without the benefit of the present invention. In respect of fluorescence transgenes, the expression is increased sufficiently to allow monitoring the fluorescence signal. More preferably, the fluorescence signal is monitored in Chlamydomonas.
[0033] The transgene is introduced in algae. In accordance with an embodiment of the present invention, the transgene is placed on a vector. The vector is a nucleic acid structure used to introduce a cassette containing a DNA sequence into an algae chromosome. The vector is introduced in the nucleus of a host algae cell and the transgene is transcribed/translated in the algae. Methods of transformation of algae are well known to artisans skilled in the art. For example, a vector construct may be introduced via electroporation, via plasmid conjugation, and via particle bombardment. The transformed algae arc recovered on a solid nutrient media or in liquid media. Elizabeth H Harris, Chlamydomonas As A Model Organism , Annual Review of Plant Physiology and Plant Molecular Biology 52:363-406 (2001) and EMBO Practical Course: Molecular Genetics of Chlamydomonas , Laboratory protocols. Geneva, Sep. 18-28, 2006.
[0034] A preferred vector of the invention is a plasmid capable of integrating the DNA sequence of interest into a chromosome of the algae. There are a large numbers of vectors known and characterized. A preferred vector of the invention is pSP124. Lumbreras et al., Efficient foreign gene expression in Chlamydomonas reinhardtii mediated by an endogenous introns, The Plant Journal 14(4):441-447 (1998).
[0035] Methods of engineering vectors are well known in the art. The vector backbone may include genes encoding transformation markers, to indicate transformation of the host cell with the vector. A transformation marker may be a selective marker gene used to select cells in which the vector is present from normal cells without the vector. Selective markers are well known to artisans skilled in the art. Commonly used selective markers include genes that confer resistance to specific antibiotics such as bleomycin. Only cells containing the vector grow in media containing the antibiotic. Other vector backbones may also include marker genes that merely indicate which cells were transformed. When such markers are used, cells with and without the vector will grow but the cells containing the vector can be distinguished from those not having the vector because they display a specific characteristic conferred by the vector, e.g., color. A commonly used transformation marker gene is the yellow or green fluorescence gene. Cells containing a vector with such a gene will be yellow or green. Other common transformation markers include various luciferase genes. Cells containing the luciferase genes emit light.
[0036] Any effective combination of gene expression regulatory features compatible with expression of genes in the algae nucleus can be incorporated in the vector. The plasmid may include different types of promoters, for example constitutive promoters or inducible promoters. Preferred transcriptional promoters in accordance to the invention include the hsp70 (“heat shock protein” promoter), rbcS (“rubisco small subunit” promoter) and tubA2 (“actin” promoter). The vector employs suitable translational enhancer elements, generally referred to as 5′untranslated regions or “5′UTR.” Preferred enhancers in accordance to the invention are the tubA2 intron 1, the HSP70 enhancer, and the rcbS2 intron 1. The vector of the invention includes also effective translational terminators, 3′UTR. Examples of preferred 3′-UTR sequences include the tubA2, HSP70, and rcbS2 3′UTR. Other effective promoters, transcription enhancers and terminators may, in particular combinations, may produce satisfactorily high and stable expression.
[0037] Some of these options are illustrated in FIGS. 1 and 2 . The features selected to be exemplified in FIGS. 1 and 2 include the promoter and 3′ UTR regions of the Chlamy genes: tubA2 encoding actin (Tubulin); rbcS2 encoding the rubisco small subunit; or nitA encoding nitrate reductase. Furthermore, the hsp70A/rbcS2 tandem promoter is a preferred driver of transgene expression. Schroda M., Beck C. F. and Vallon A., Sequence elements within an hsp70 promoter counteract transcriptional transgene silencing in Chlamydomonas . Plant J. 31:445-455 (2002). This chimeric promoter contains the enhancer region of the nucleo-cytoplasmic-localized 70 kD heat shock protein gene (NCBI GenBank ID: M76725; by 572-833) and the promoter from the nuclear rubisco small subunit gene (NBCI GenBank ID: X04472; by 934-1142). Additionally, the first intron (bp 1307-1451) and 3′-untranslated region (bp 2401-2632) of the rbcS2 gene may be included to further promote stable transgene expression.
[0038] In accordance with an embodiment of the present invention, one or more vectors are used to introduce a cassette that contains a gene of interest (“GOI”) and a gene silencing inhibitor into the nucleus DNA of algae, e.g., a Chlamy nucleus. The GOI can be any gene desirably expressed in algae. Viable genes of interest include genes involved in controlling algae's metabolic pathways. For example, in one embodiment of the present invention the Bcl-x L gene can be inserted and expressed in the algae's nucleus. Bcl-x L is an abbreviation for B-cell lymphoma extra-large; it is known to be an inhibitor of apoptosis (programmed cell death). Boise L. H. et al., Bcl - x, a bcl -2- related Gene that Functions as a Dominant Regulator of Apoptotic Cell Death , Cell 74:597-608 (1993). In another embodiment genes affecting lipid or isoprenoid production pathways are desirably introduced. Due to Bcl-x L 's ability to inhibit apoptosis, its expression allows algae cells to live longer. A longer lifespan for microalgae enables the use of microalgae in various industrial applications such as photobioreactors.
[0039] A gene silencing inhibitor is also introduced into the algae. A gene silencing inhibitor is a peptide that induces relaxation of nucleosomes in the algae's nucleus. Gene silencing inhibitors include histone acetyl transferases (HATs) and other peptides that modify elements of the nucleosome, causing the chromatin structure to relax and to allow transcription factors to access the gene of interest. HAT proteins and the HAT domains of p300 and of other HAT proteins are known to cause histone acetylation and can be utilized in the invention. In accordance to the invention the domain responsible for the acetylation activity or the whole protein is deployed. See Fukuda H, et al., Brief Funct. Genomic Proteomic, 5(3):190-208 (2006); Renthal W. and Nestler E. J., Semin Cell Dev Biol. 20(4):387-94 (Epub 2009); and Lin Y. Y. et al., Genes Dev., 22(15):2062-74 (2008).
[0040] One preferred embodiment of the present invention utilizes a p300 protein as a gene silencing inhibitor. More preferably, a Chlamy derived p300 protein is utilized. In a yet more preferred embodiment, the Chlamy p300 protein is the homologue detailed in FIG. 3 . In a further more preferred embodiment, only the HAT domain of the Chlamy p300 gene is utilized. See FIG. 3 and relevant portion of SEQ ID NO 4.
[0041] FIG. 3 shows an alignment comparison of the Chlamy p300 with phylogenetically distinct other p300 homologues. The lighter colored section of each bar represents the histone acetylase (HAT) domain. The HAT domains are aligned for visualization purposes. These lighter bars include numbers that are indicative of the percent identity of the HAT domain of each protein proteins with the indicated percentages of identity of each HAT protein to the p300 HAT domain of the p300 protein from Chlamy. FIG. 3 is drawn to scale, both in respect to the overall size of the p300 proteins and the location of the HAT domain within the protein.
[0042] Table 1, exemplifies the highly conserved nature of the p300 proteins and particularly conserved nature of the HAT domains.
[0000]
TABLE 1
Comparison of HAT domain identity within each phylogenetic clade. The
bolded organism at the top of each column is the representative species
to which all other percent identities are based.
- 100%
- 100%
- 100%
- 100%
V. carteri - 85%
G. max - 91%
A. gambiae - 92%
M. mulatta - 100%
O. sativa - 91%
O. cuniculus - 100%
S. bicolor - 90%
C. floridanus - 89%
R. norvegicus - 99%
P. trichocarpa - 88%
M. musculus - 99%
Microalgae
Higher Plants
Insects
Mammals
[0043] Indeed, the percent identity between plant and mammalian p300 homologues is also very high, typically at least about 80%. See US Patent Publication US2003/0145349. However, the homology of the Chlamy p300 homologue to other organisms is lower. Likewise, the p300 full protein of Chlamydomonas reinhardtii is 11.5% identical and further 9.9% similar to the mouse p300 protein; 9.1% identical and a further 4.7% similar to the Drosophila p300 protein; and 23.6% identical and a further 9.9% similar to the Arabidopsis p300 protein. The Chlamy derived protein has N-terminal or C-terminal regions which are shorter and dissimilar in their location visa-vie the HAT domain to these of the mammalian or plant p300 proteins. See FIG. 3 . This is suggestive of proteins with overall distinct functions and phylogeny.
[0044] The various proteins p300 homologues in FIG. 1 and described herein elsewhere are:
C. reinhardtii p300/HAT Protein ID: 159467703 from NCBI Database. V. carteri p300/CBP Protein ID: 300256266 from NCBI Database. S. bicolor putative p300 Protein ID: C5XTZ4 from Universal Protein Resource. P. trichocarpa GenBank ID: POPTR — 007s15090 from Joint Genome Institute Database. G. max Protein ID: PF02135 from Joint Genome Institute Database. A. thaliana HAC1/p300/CBP GenBank ID: NM — 106550.3 from NCBI Database. O. sativa p300/CBP Protein ID: 108792657 from NCBI Database. D. melanogaster CBP/HAT Genbank ID: NM — 079903.2 from NCBI Database. A. gambiae HAT Protein ID: 158289391 from NCBI Database. C. floridanus CBP Protein ID: 307172990 from NCBI Database. M. musculus E1A/BP/p300 GenBank ID: NM — 177821.6 from NCBI Database. O. cuniculus p300 Protein ID: 291410334 from NCBI Database. R. norvegicus p300 Protein ID: XP — 576312.3 from NCBI Database. M. mulatta p300 HAT Protein ID: XP — 001102844.1 from NCBI Database. H. sapiens p300 Protein ID: NP — 001420.2 from NCBI Database.
[0060] In another preferred embodiment of the present invention, the gene silencing inhibitor is functionally tethered or, preferably, fused to a DNA binding protein or domain thereof (the tethered/fused protein or its/their gene hereinafter are referred to as the gene expression enhancer unit, or “GEE”). The DNA binding protein or domain binds to a particular DNA sequence (Binding Site or “BS”), bringing the gene silencing inhibitor to its histone target at a location in the vicinity of the BS and thereby inducing relaxation of the nucleosome at that genetic location. As the nucleosome relaxes, the nearby DNA sequence is exposed to transcription factors and is more actively transcribed.
[0061] In accordance to a preferred embodiment, the invention requires the expression in an algae protein that binds specific DNA sequences, which sequences can be engineered upstream of any GOI for expression in algae. The DNA binding protein/domain can be any protein having known DNA binding sites can be used. Examples of proteins targeting specific DNA motifs applicable to this invention include the Ga14 protein and Early Growth Response Protein 1. DNA binding site motifs for these proteins are known. Likewise, the binding domains of these as well as the LexA protein are known and are preferentially used, instead of the full-length protein. See for example Young, K., Biol. Reprod., 58:302-311 (1998) and Joung, J. et al., Proc. Natnl. Acad. Sci., 97:7382-7 (2000). The DNA binding site (BS) for Gal4 is 5′-CGGAGGACAGTCCTCCG-3′.
[0062] LexA is a preferred example of a DNA binding protein. LexA is a gene of bacterial origin. LexA proteins or genes are not known in algae. Thus, it is unlikely that the Chlamy genome will contain the DNA binding sequence of LexA. The function of LexA in the context of the invention is to bind a particular DNA sequence (binding site, “BS”). LexA binding sites are found upstream promoters in a number of microorganisms. A consensus BS sequence for LexA is CTGTATATATATACAG. SEQ ID NO 9. The binding domain of the LexA protein is known and, for the purpose of the invention, it is preferred to employ only the binding domain. Protein ID: 2293118 from NCBI Database:
[0000]
MKALTARQQEVFDLIRDHISQTGMPPTRAEIAQRLGFRSPNAAEEHLKA
LARKGVIEIVSGASRGIRLLQEEEEGLPLVGRVAAGEPLLAQQHIEGHY
QVDPSLFKPNADFLLRVSGMSMKDIGIMDGDLLAVHKTQDVRNGQVVVA
RIDDEVTVKRLKKQGNKVELLPENSEFKPIVVDLRQQSFTIEGLAVGVI
RNGDWLEFPGIRRPWRPLESTCSQANSGRISYDL.
[0063] As noted above, the DNA binding protein or domain thereof, preferably the LexA domain, is constructed to translate in a protein allowing the DNA binding domain and a nucleosome relaxation protein to act in concert. Any nucleosome relaxation protein might be used. Preferably, as noted above, a Chlamy p300 domain is used.
[0064] Without being limited to a single mechanism of action, it is proposed that one partner binds to the DNA, the other acetylates nearby histones, thereby creating a looser association between the DNA and the histones at that site. Therefore any method to render the DNA binding domain and the acetylase domain spatially close to each other is preferred. A fused protein is more preferred. The order of the two units (N-terminal proximity) within the fusion protein is not critical. However, in the p300-LexA binding domain example, it is preferred that LexA binding domain is at the N-terminal end of the fusion. “Functional” fusion proteins are designed. By way of example, certain linker regions are introduced to allow flexibility, orientation or simply “dead” protein sequence corresponding to strategically placed genetic engineering features such as primers and restriction enzyme sites.
[0065] Preferably, the GEE can be a p300 peptide homolog and the DNA binding domain can be LexA binding domain, creating a p300-LexA binding domain fusion protein and its gene construct. Preferably, that fusion is an algae p300-LexA binding domain fusion. More preferably, the fusion is the Chlamy p300-LexA fusion. Alternatively, the fusion comprises select domains of the Chlamy p300-LexA proteins. See SEQ ID NO 4. Yet more preferably, the fusion, at the nucleic acid level, comprises a LexA sequence modified in its codon usage for higher yield when expressed in algae. Preferably, the whole of the GEE fusion protein gene was designed for preferred codon usage in algae, even if part of the gene (p300) is an algae derived gene, as provided by SEQ ID NO 1 and SEQ ID NO 3. Indeed, the transgene (GOI) and other genes in the system preferably arc codon optimized based on codon frequency in algae.
[0066] It should be noted that other algae p300 homologues or their acetylasehistone acetyltransferase (HAT) domains may be preferentially used in the invention. However, these preferred homologues must be at least about 60% identical to the Chlamy p300, preferably at least about 70% identical, at least about 80% identical, at least about 85% identical, at least about 90% identical or more. A p300 homologue from V. carteri (algae) was recently identified. It has about 85% identity to the Chlamy p300, over the HAT domains.
[0067] The LexA-p300 fusion DNA (SEQ ID 1) is the nucleotide sequence encoding a fusion protein (exemplary GEE) comprising the LexA binding domain and the full length Chlamy p300 sequence, all of the fusion designed to reflect preferred codon usage in algae. It was adapted to the nuclear codon usage of C. reinhardtii according to the table provided by the Kazusa Codon Usage Database (Species ID: 3055), using Gene Designer software from DNA 20. The sequence up to nucleotide 690 is that of the LexA DNA binding domain and the fell length C. reinhardtii p300 sequence begins at nucleotide 700. A 3-amino acid peptide linker (GVL) connects LexA binding domain and p300, which represents the DNA restriction site PpuMI (9 bp). The LexA gene sequence is codon-optimized for C. reinhardtii nuclear expression using AA sequence from Protein ID: 2293118 from NCBI Database:
[0000]
SEQ ID NO 1
1
ATGAAGGCTCTGACCGCTCGCCAGCAGGAGGTGTTTGATCTGATTCGGGA
51
CCATATCAGCCAAACGGGCATGCCCCCTACGCGCGCGGAGATCGCGCAAC
101
GGCTGGGCTTCCGCTCCCCGAACGCGGCTGAGGAGCACCTGAAGGCGCTG
151
GCGCGCAAGGGTGTGATTGAGATCGTCTCCGGCGCGTCGCGGGGCATTCG
201
GCTGCTGCAGGAGGAGGAGGAGGGTCTGCCTCTGGTGGGGCGGGTGGCTG
251
CGGGCGAGCCCCTGCTGGCCCAGCAGCACATTGAGGGCCACTACCAAGTG
301
GACCCGTCCCTCTTCAAGCCGAACGCCGATTTCCTGCTGCGCGTCAGCGG
351
TATGAGCATGAAGGACATCGGCATCATGGACGGTGACCTGCTGGCCGTGC
401
ATAAGACGCAGGACGTGCGCAACGGCCAAGTGGTCGTCGCCCGCATCGAT
451
GACGAGGTGACCGTGAAGCGCCTGAAGAAGCAGGGGAACAAGGTCGAGCT
501
GCTGCCCGAGAACAGCGAGTTCAAGCCCATCGTGGTGGATCTGCGCCAGC
551
AATCCTTCACCATCGAGGGCCTGGCGGTGGGCGTGATCCGCAACGGCGAC
601
TGGCTGGAGTTCCCGGGCATCCGCCGCCCGTGGCGCCCTCTGGAGTCCAC
651
GTGCTCGCAGGCCAACTCCGGCCGCATTAGCTACGACCTGGGGGTCCTTA
701
TGGTGCCGATGGGCGCGCCCGCTATGCCCATGGGCAACAACGGCTCGCCC
751
ATGCTGAACGGCATGGGTATGTTCAACGCCCCGCAGCAGACCGTGCCCAA
801
CGGCGGGCCGGGTGGCGTGAACCCCATGGGCCAGGTGCCGGCGATGCCTG
851
CGCCGATCCCCAACGGCGGTCTGCCCGGTATGAACGCTGCCGGCGGTGCC
901
GACGATCCTGCGAAGCAGCGGGAGCAATCGATCCAGAAGCAGCAGCGCTG
951
GCTGCTGTTCCTGCGGCACTGCGCGAAGTGCCGGGCTCCCGGCGAGGACT
1001
GCCAGCTGAAGTCCCAGTGCAAGTTCGGCAAGCAGCTGTGGCAGCACATC
1051
CTGTCGTGCCAAAACCCGGCCTGCGAGTACCCGCGCTGCACCAACTCCAA
1101
GGATCTGCTCAAGCACCACCAGAAGTGCCAGGAGCAGACCTGCCCCGTGT
1151
GCATGCCGGTGAAGGACTACGTGAAGAAGACGCGCCAGGCGACCCAACAG
1201
CAGCAACAAATGCAGCAACAACAGCAAATCCAGCAACAGCAACAACAACA
1251
AATGCAACAGCAACAGATGCAACAGCAGCAGCTCCAGCAGCAGCAGATGC
1301
AACAACAACAGCAGATGCAGCAGCAGCAACAGCCCGGCGTGGGCGCCAAC
1351
TTCATGCCCACCCCGCCCATGATGCCGAACGGCATGTTCCCTCAACAGCA
1401
GCCCCAGCAGGCGATGCGCCTGAACGCCAACGGCCTCGGCGGCCAGAAGC
1451
GCCCCCACGAGATGATGGGTATGTCCAGCGGCGGCATGGACGGTATGAAC
1501
CAGATGGTGCCCGTCGGCGGCGGCGGCATGGGCATGTCGATGCCGATGGG
1551
TATGAACAACCCCATGCAGGGCGGTATGCCCCTGCAGCCTCCGCCCCAGG
1601
TGCAGGCTCCCGGTCAGGGCCCCATGATGAGCGCCCCTCAGCAGCAACAG
1651
CAGCAACCGGCCCCTAAGCGGGCGAAGACCGACGATGTGCTGCGCCAGAA
1701
CACGGGCACCAGCCTCCTGGAGACGTTCGACGCCAAGCAGATCCGCGTGC
1751
ACGTGGACCTGATCCGCGCTGCCGCGGTGACCCAGAAGGCCCAGCAGCCT
1801
CCCCCGGCTAACCCCGACGACGCGTGCAAGGTCTGCGCGCTGACGAAGCT
1851
GTCGTTCGAGCCCCCGGTGATTTACTGCTCGAGCTGCGGCCTGCGCATCA
1901
AGCGCGGCCAGATCTTCTACAGCACGCCTCCGGACCACGGCAACGACCTG
1951
AAGGGTTACTTCTGCCACCAGTGCTTCACCGACCAGAAGGGCGAGCGCAT
2001
CCTGGIGGAGGGCGTCTCGATCAAGAAGAGCGACCTGGTGAAGCGCAAGA
2051
ACGATGAGGAGATCGAGGAGGGGTGGGTGCAGTGCGACCACTGCGAGGGC
2101
TGGGTGCACCAGATTTGCGGCATGTTCAACAAGGGCCGGAACAACACGGA
2151
CGTCCACTACCTGTGCCCTGACTGCCTGGCCGTGGGCTACGAGCGCGGCC
2201
AGCGCCAGAAGACGGAGGTCCGCCCCCAGGCGATGCTCGAGGCGAAGGAT
2251
CTGCCCACGTCCCGGCTGTCCGAGTTTATTACGGAGCGCCTGAACCGCGA
2301
GCTGGAGAAGGAGCACCACAAGCGGGCTGAGCAGCAGGGCAAGCCGCTGC
2351
ACGAGGTGGCGAAGCCCGAGCCCCTGACCGTGCGGATGATCAACTCCGTG
2401
ATGAAGAAGTGCGAGGTCAAGCCGCGCTTCCACGAGACGTTCGGCCCCAC
2451
CGACGGCTACCCCGGGGAGTTCGGCTACCGGCAGAAGGTGCTGCTGCTGT
2501
TCCAAAGCCTGGACGGTGTCGACGTGTGCCTGTTCTGCATGTACGTGCAG
2551
GAGTACGGCAAGGACTGCCCTGCGCCCAACACCAACGTGGTGTACCTGTC
2601
GTATCTGGACTCCGTCAAGTACTTCCGCCCTGAGATTCCCTCGGCCCTGG
2651
GCCCTGCCGTGTCGCTGCGCACCTTCGTGTACCACCAACTCCTGATCGCC
2701
TACGTGGAGTTTACCCGCAACATGGGTTTTGAGCAGATGTACATTTGGGC
2751
GTGCCCGCCGATGCAAGGCGACGACTACATCCTGTACTGCCACCCGACCA
2801
AGCAGAAGACGCCGCGCTCGGACCGCCTGCGCATGTGGTACATTGAGATG
2851
CTGAAGCTGGCGAAGGAGGAGGGTATCGTGAAGCACCTGAGCACGCTGTG
2901
GGATACGTACTTCGAGGGCGGTCGCGACCACCGGATGGAGCGCTGCTCGG
2951
TCACGTACATTCCGTACATGGAGGGCGACTACTGGCCCGGCGAGGCTGAG
3001
AACCAGCTCATGGCCATTAACGACGCGGCCAAGGGCAAGCCTGGGACCAA
3051
GGGTGCGGGCAGCGCCCCGAGCCGCAAGGCCGGTGCCAAGGGCAAGCGCT
3101
ACGGCGGTGGCCCCGCCACGGCTGATGAGCAGCTGATGGCCCGCCTCGGT
3151
GAGATCCTGGGCGGGAACATGCGGGAGGACTTCATTGTGGTCCACATGCA
3201
GGTGCCCTGCACGTTCTGCCGCGCTCACATTCGGGGTCCGAACGTGGTGT
3251
ACCGCTATCGGACGCCGCCTGGCGCGACCCCTCCCAAGGCTGCCCCCGAG
3301
CGCAAGTTCGAGGGCATCAAGCTGGAGGGCGGTGGCCCCAGCGTGCCCGT
3351
GGGCACCGTCTCGAGCCTGACGATCTGCGAGGCGTGCTTTCGCGACGAGG
3401
AGACGCGCACGCTGACCGGCCAACAGCTGCGCCTGCCCGCTGGCGTGTCG
3451
ACCGCTGAGCTCGCGATGGAGAAGCTGGAGGAGATGATCCAGTGGGACCG
3501
CGACCCTGACGGCGACATGGAGAGCGAGTTCTTCGAGACGCGGCAGACCT
3551
TCCTGTCGCTGTGCCAGGGCAACCACTACCAGTTCGACACCCTCCGCCGC
3601
GCTAAGCACTCGTCGATGATGGTGCTCTACCACCTGCACAACCCCCACTC
3651
GCCGGCGTTCGCGTCCTCGTGCAACCAGTGCAACGCCGAGATCGAGCCGG
3701
GCAGCGGCTTTCGCTGCACCGTGTGCCCCGACTTCGACATGTGCGCCAGC
3751
TGCAAGGTCAACCCTCATAAGCGCGCCCTGGACGAGACGCGCCAGCGGCT
3801
GACCGAGGCCGAGCGCCGGGAGCGCAACGAGCAGCTGCAGAAGACCCTCG
3851
CCCTGCTGGTGCACGCCTGCGGCTGCCACAACAGCGCGTGCGGCTCCAAC
3901
AGCTGCCGCAAGGTGAAGCAGCTGTTCCAGCACGCGGTCCACTGCCAGAG
3951
CAAGGTGACCGGGGGCTGCCAGCTGTGCAAGAAGATGIGGTGCCTGCTGA
4001
ACCTGCACGCCAAGTCCTGCACCCGCGCGGACTGCCCGGTGCCGCGCTGC
4051
AAGGAGCTGAAGGAGCTGCGCCGGCGCCAAACGAACCGGCAGGAGGAGAA
4101
GCGCCGGGCGGCCTACGCCGCTATGCTGCGCAACCAGATGGCCGGCAGCC
4151
AGGCTCCGCGCCCCATGTAA.
[0068] LexA-p300 Fusion Protein (SEQ ID NO 2) is the respective protein sequence encoded by the nucleic acid sequence of SEQ ID NO 1. The LexA binding domain is the sequence up to and including amino acid 230 and the full-length p300 HAT domain sequence begins at amino acid 234. A 3-amino acid peptide linker (GVL) connects LexA binding domain and p300, which represents the DNA restriction site PpuMI (9 bp):
[0000]
SEQ ID NO 2
1
MKALTARQQEVFDLIRDHISQTGMPPTRAEIAQRLGFRSPNAAEEHLKAL
51
ARKGVIEIVSGASRGIRLLQEEEEGLPLVGRVAAGEPLLAQQHIEGHYQV
101
DPSLFKPNADFLLRVSGMSMKDIGIMDGDLLAVHKTQDVRNGQVVVARID
151
DEVTVKRLKKQGNKVELLPENSEFKPIVVDLRQQSFTIEGLAVGVIRNGD
201
WLEFPGIRRPWRPLESTCSQANSGRISYDLGVLMVPMGAPAMPMGNNGSP
251
MLNGMGMFNAPQQTVPNGGPGGVNPMGQVPAMPAPIPNGGLPGMNAAGGA
301
DDPAKQREQSIQKQQRWLLFLRHCAKCRAPGEDCQLKSQCKFGKQLWQHI
351
LSCQNPACEYPRCTNSKDLLKHHQKCQEQTCPVCMPVKDYVKKTRQATQQ
401
QQQMQQQQQIQQQQQQQMQQQQMQQQQLQQQQMQQQQQMQQQQQPGVGAN
451
FMPTPPMMPNGMFPQQQPQQAMRLNANGLGGQKRPHEMMGMSSGGMDGMN
501
QMVPVGGGGMGMSMPMGMNNPMQGGMPLQPPPQVQAPGQGPMMSAPQQQQ
551
QQPAPKRAKTDDVLRQNTGTSLLETFDAKQIRVHVDLIRAAAVTQKAQQP
601
PPANPDDACKVCALTKLSFEPPVIYCSSCGLRIKRGQIFYSTPPDHGNDL
651
KGYFCHQCFTDQKGERILVEGVSIKKSDLVKRKNDEEIEEGWVQCDHCEG
701
WVHQICGMFNKGRNNTDVHYLCPDCLAVGYERGQRQKTEVRPQAMLEAKD
751
LPTSRLSEFITERLNRELEKEHHKRAEQQGKPLHEVAKPEPLTVRMINSV
801
MKKCEVKPRFHETFGPTDGYPGEFGYRQKVLLLFQSLDGVDVCLFCMYVQ
851
EYGKDCPAPNTNVVYLSYLDSVKYFRPEIPSALGPAVSLRTFVYHQLLIA
901
YVEFTRNMGFEQMYIWACPPMQGDDYILYCHPTKQKTPRSDRLRMWYIEM
951
LKLAKEEGIVKHLSTLWDTYFEGGRDHRMERCSVTYIPYMEGDYWPGEAE
1001
NQLMAINDAAKGKPGTKGAGSAPSRKAGAKGKRYGGGPATADEQLMARLG
1051
EILGGNMREDFIVVHMQVPCTFCRAHIRGPNVVYRYRIPPGATPPKAAPE
1101
RKFEGIKLEGGGPSVPVGTVSSLTICEACFRDEETRTLTGQQLRLPAGVS
1151
TAELAMEKLEEMIQWDRDPDGDMESEFFETRQTFLSLCQGNHYQFDTLRR
1201
AKHSSMMVLYHLHNPHSPAFASSCNQCNAEIEPGSGFRCTVCPDFDMCAS
1251
CKVNPHKRALDETRQRLTEAERRERNEQLQKTLALLVHACGCHNSACGSN
1301
SCRKVKQLFQHAVHCQSKVTGGCQLCKKMWCLLNLHAKSCTRADCPVPRC
1351
KELKELRRRQTNRQEEKRRAAYAAMLRNQMAGSQAPRPM*.
[0069] LexA-p300 HAT domain DNA (SEQ ID NO 3) is a nucleic acid sequence corresponding to a gene encoding the LexA binding domain-acetyl-transferase (HAT) domain of the Chlamy p300 protein. Similarly, the LexA binding domain is the sequence up to and including nucleotide 690 and the p300 HAT domain sequence begins at nucleotide 700. A 3-amino acid peptide linker (GVL) connects LexA binding domain and p300, which represents the DNA restriction site PpuMI (9 bp).
[0000]
SEQ ID NO 3
1
ATGAAGGCTCTCACCGCTCGCCAACAGGAGGTCTTTGATCTGATTCGCGA
51
CCACATCTCGCAGACCGGCATGCCGCCGACCCGGGCGGAGATTGCTCAGC
101
GGCTGGGCTTCCGGAGCCCCAACGCGGCCGAGGAGCACCTGAAGGCCCTC
151
GCGCGCAAGGGGGTGATCGAGATTGTCTCCGGCGCTAGCCGCGGCATCCG
201
CCTGCTGCAGGAGGAGGAGGAGGGCCTGCCGCTGGTCGGGCGGGTCGCGG
251
CCGGGGAGCCTCTGCTGGCCCAGCAGCACATCGAGGGCCACTACCAAGTG
301
GACCCCTCGCTGTTTAAGCCCAACGCGGACTTCCTGCTCCGGGTGTCGGG
351
CATGAGCATGAAGGACATCGGCATCATGGACGGCGACCTCCTGGCGGTGC
401
ACAAGACCCAGGACGTGCGCAACGGCCAGGTGGTCGTCGCGCGGATTGAC
451
GACGAGGTGACCGTGAAGCGGCTGAAGAAGCAGGGCAACAAGGTCGAGCT
501
GCTGCCCGAGAACTCGGAGTTCAAGCCTATCGTGGTCGACCTGCGCCAGC
551
AGTCCTTCACCATCGAGGGCCTGGCCGTGGGGGTCATCCGCAACGGTGAC
601
TGGCTGGAGTTCCCCGGCATCCGGCGCCCGTGGCGGCCGCTGGAGTCCAC
651
CTGCAGCCAGGCGAACTCCGGCCGCATCTCCTACGATCTGGGGGTCCTTG
701
AGGTGGCCAAGCCGGAGCCGCTGACCGTGCGGATGATCAACAGCGTGATG
751
AAGAAGTGCGAGGTCAAGCCCCGCTTCCACGAGACGTTCGGTCCGACCGA
801
CGGTTACCCCGGGGAGTTCGGCTACCGGCAGAAGGTGCTCCTCCTGTTCC
851
AGTCCCTCGACGGCGTCGACGTGTGCCTGTTCTGCATGTACGTGCAGGAG
901
TACGGGAAGGACTGCCCGGCGCCCAACACGAACGTGGTGTACCTGAGCTA
951
CCTGGACTCCGTCAAGTATTTCCGCCCCGAGATTCCCAGCGCCCTGGGCC
1001
CTGCGGTGAGCCTGCGGACCTTCGTGTACCACCAGCTCCTGATTGCGTAC
1051
GTGGAGTTCACGCGCAACATGGGCTTCGAGCAGATGTACATTTGGGCGTG
1101
CCCCCCCATGCAGGGGGACGACTATATCCTGTATTGCCATCCCACGAAGC
1151
AGAAGACCCCGCGCTCGGACCGCCTGCGCATGTGGTACATCGAGATGCTG
1201
AAGCTGGCTAAGGAGGAGGGCATCGTGAAGCACCTGTCGACGCTGTGGGA
1251
CACCTACTTCGAGGGCGGTCGCGACCACCGGATGGAGCGCTGCAGCGTGA
1301
CCTACATCCCCTACATGGAGGGCGACTACTGGCCTGGCGAGGCCGAGTAA.
[0070] LexA-p300 HAT domain AA (SEQ ID NO 4) is an exemplary GEE protein sequence of a LexA binding domain-Chlamy p300 protein, where the Chlamy p300 is limited to the histone acetyl-transferase (HAT) domain of the Chlamy p300 enzyme. The LexA binding domain is the sequence up to and including amino acid 230 and the p300 HAT domain sequence begins at amino acid 234. The 3-amino acid peptide linker (GVL) connects LexA binding domain and p300:
[0000]
SEQ ID NO 4
1
MKALTARQQEVFDLIRDHISQTGMPPTRAEIAQRLGFRSPNAAEEHLKAL
51
ARKGVIEIVSGASRGIRLLQEEEEGLPLVGRVAAGEPLLAQQHIEGHYQV
101
DPSLFKPNADFLLRVSGMSMKDIGIMDGDLLAVHKTQDVRNGQVVVARID
151
DEVTVKRLKKQGNKVELLPENSEFKPIVVDLRQQSFTIEGLAVGVIRNGD
201
WLEFPGIRRPWRPLESTCSQANSGRISYDLGVLEVAKPEPLTVRMINSVM
251
KKCEVKPRFHETFGPTDGYPGEFGYRQKVLLLFQSLDGVDVCLFCMYVQE
301
YGKDCPAPNTNVVYLSYLDSVKYFRPEIPSALGPAVSLRTFVYHQLLIAY
351
VEFTRNMGFEQMYIWACPPMQGDDYILYCHPTKQKTPRSDRLRMWYIEML
401
KLAKEEGIVKHLSTLWDTYFEGGRDHRMERCSVTYIPYMEGDYWPGEAE*.
[0071] Codon-optimized Venus gene sequence is a preferred embodiment:
[0000]
SEQ ID NO 5
1
ATGGTGTCGAAGGGTGAGGAGCTGTTTACCGGTGTCGTGCCTATTCTGGT
51
GGAGCTCGACGGCGACGTCAACGGGCACAAGTTTTCGGTGTCCGGCGAGG
101
GTGAGGGGGACGCGACGTACGGCAAGCTCACGCTGAAGCTGATCTGCACC
151
ACCGGCAAGCTGCCCGTCCCCTGGCCGACGCTGGTGACCACCCTGGGCTA
201
CGGCCTGCAGTGCTTCGCCCGCTACCCGGACCACATGAAGCAGCACGACT
251
TCTTCAAGTCGGCCATGCCCGAGGGGTACGTGCAGGAGCGCACGATCTTC
301
TTTAAGGACGATGGCAACTACAAGACCCGCGCTGAGGTGAAGTTCGAGGG
351
CGATACGCTGGTGAACCGCATCGAGCTCAAGGGCATCGACTTCAAGGAGG
401
ACGGCAACATCCTGGGTCACAAGCTGGAGTACAACTACAACTCCCACAAC
451
GTGTACATCACGGCGGATAAGCAGAAGAACGGCATCAAGGCCAACTTTAA
501
GATTCGCCATAACATCGAGGACGGCGGCGTGCAGCTCGCCGACCACTACC
551
AGCAGAACACCCCGATCGGCGACGGCCCCGTGCTGCTGCCCGATAACCAC
601
TACCTCAGCTACCAGTCGGCCCTGTCCAAGGATCCCAACGAGAAGCGCGA
651
TCACATGGTCCTCCTGGAGTTCGTGACCGCCGCTGGCATCACCCTGGGCA
701
TGGACGAGCTGTACAAGTAA.
[0072] SEQ ID NO 6 is the protein encoded by the nucleic acid of SEQ ID NO 5. The Venus AA sequence:
[0000]
SEQ ID NO 6
1
MVSKGEELFTGVVPILVELDGDVNGHKFSVSGEGEGDATYGKLTLKLICT
51
TGKLPVPWPTLVTTLGYGLQCFARYPDHMKQHDFFKSAMPEGYVQERTIF
101
FKDDGNYKTRAEVKFEGDTLVNRIELKGIDFKEDGNILGHKLEYNYNSHN
151
VYITADKQKNGIKANFKIRHNIEDGGVQLADHYQQNTPIGDGPVLLPDNH
201
YLSYQSALSKDPNEKRDHMVLLEFVTAAGITLGMDELYK*.
[0073] SEQ ID NO 7 is a nucleic acid encoding a Venus-Bcl-x L fusion of the invention. It was designed to represent preferred codon usage in algae. The sequence up to and including nucleotide 717 represents Venus. A 3-amino acid peptide linker (CVL) connects Venus and Bcl-x L , which represents the DNA restriction site PpuMI (9 bp). Bcl-x L begins at nucleotide 726.
[0000]
SEQ ID NO 7
1
ATGGTGTCGAAGGGTGAGGAGCTGTTTACCGGTGTCGTGCCTATTCTGGT
51
GGAGCTCGACGGCGACGTCAACGGGCACAAGTTTTCGGTGTCCGGCGAGG
101
GTGAGGGGGACGCGACGTACGGCAAGCTCACGCTGAAGCTGATCTGCACC
151
ACCGGCAAGCTGCCCGTCCCCTGGCCGACGCTGGTGACCACCCTGGGCTA
201
CGGCCTGCAGTGCTTCGCCCGCTACCCGGACCACATGAAGCAGCACGACT
251
TCTTCAAGTCGGCCATGCCCGAGGGGTACGTGCAGGAGCGCACGATCTTC
301
TTTAAGGACGATGGCAACTACAAGACCCGCGCTGAGGTGAAGTTCGAGGG
351
CGATACGCTGGTGAACCGCATCGAGCTCAAGGGCATCGACTTCAAGGAGG
401
ACGGCAACATCCTGGGTCACAAGCTGGAGTACAACTACAACTCCCACAAC
451
GTGTACATCACGGCGGATAAGCAGAAGAACGGCATCAAGGCCAACTTTAA
501
GATTCGCCATAACATCGAGGACGGCGGCGTGCAGCTCGCCGACCACTACC
551
AGCAGAACACCCCGATCGGCGACGGCCCCGTGCTGCTGCCCGATAACCAC
601
TACCTCAGCTACCAGTCGGCCCTGTCCAAGGATCCCAACGAGAAGCGCGA
651
TCACATGGTCCTCCTGGAGTTCGTGACCGCCGCTGGCATCACCCTGGGCA
701
TGGACGAGCTGTACAAGGGGGTCCTTATGAGCCAGAGCAACCGGGAGCTG
751
GTGGTGGACTTCCTGAGCTACAAGCTGAGCCAAAAGGGCTATAGCTGGTC
801
GCAGTTCTCCGACGTCGAGGAGAACCGGACCGAGGCCCCCGAGGGGACCG
851
AGTCCGAGATGGAGACGCCGAGCGCGATTAACGGCAACCCGAGCTGGCAC
901
CTGGCGGACTCCCCTGCCGTGAACGGCGCGACCGGCCACAGCTCCAGCCT
951
GGACGCGCGCGAGGTCATCCCGATGGCGGCCGTGAAGCAGGCCCTCCGCG
1001
AGGCCGGCGACGAGTTCGAGCTGCGCTATCGCCGCGCTTTCTCGGACCTG
1051
ACCAGCCAGCTGCACATCACCCCCGGCACGGCTTACCAAAGCTTCGAGCA
1101
GGTGGTGAACGAGCTGTTCCGCGACGGCGTGAACTGGGGTCGCATCGTGG
1151
CGTTCTTCAGCTTCGGCGGTGCGCTGTGCGTGGAGAGCGTCGACAAGGAG
1201
ATGCAGGTGCTGGTGTCGCGCATTGCGGCTTGGATGGCCACCTACCTGAA
1251
CGACCACCTGGAGCCCTGGATTCAGGAGAACGGCGGCTGGGACACCTTCG
1301
TCGAGCTGTACGGCAACAACGCTGCGGCGGAGAGCCGCAAGGGCCAAGAG
1351
CGGTTCAACCGCTGGTTCCTCACGGGGATGACCGTGGCGGGCGTCGTCCT
1401
GCTGGGCAGCCTGTTCTCGCGGAAGTAA.
[0074] Venus-Bcl-x L Protein (SEQ ID NO 8) is the protein fusion encoded by the nucleic acid of SEQ ID NO 7. The underlying Bcl-x L protein sequence (233 AA) is encoded by the DNA sequence GenBank ID: 20336334 from NCBI Database:
[0000]
SEQ ID NO 8
1
MVSKGEELFTGVVPILVELDGDVNGHKFSVSGEGEGDATYGKLTLKLICT
51
TGKLPVPWPTLVTTLGYGLQCFARYPDHMKQHDFFKSAMPEGYVQERTIF
101
FKDDGNYKTRAEVKFEGDTLVNRIELKGIDFKEDGNILGHKLEYNYNSHN
151
VYITADKQKNGIKANFKIRHNIEDGGVQLADHYQQNTPIGDGPVLLPDNH
201
YLSYQSALSKDPNEKRDHMVLLEFVTAAGITLGMDELYKGVLMSQSNREL
251
VVDFLSYKLSQKGYSWSQFSDVEENRTEAPEGTESEMETPSAINGNPSWH
301
LADSPAVNGATGHSSSLDAREVIPMAAVKQALREAGDEFELRYRRAFSDL
351
TSQLHITPGTAYQSFEQVVNELFRDGVNWGRIVAFFSFGGALCVESVDKE
401
MQVLVSRIAAWMATYLNDHLEPWIQENGGWDTFVELYGNNAAAESRKGQE
451
RFNRWFLTGMTVAGVVLLGSLFSRK*.
EXAMPLE 1
An Exemplary Vector of the Invention
[0075] FIG. 1 illustrates a construct in accordance to the invention. The starting vector is pSP124. See V. Lumbreras, D. R. S. and S. Purton, Plant J., 14(4):441-447 (1998). Features of the vector are listed in FIG. 1 , i.e. the two regions indicated in FIG. 1 to be part of the backbone vector, pSP124.
[0076] None pSP124 sequences are preferably engineered as individual synthetic DNA fragments and strung together via restriction enzyme sites, by well-known techniques. Alternative approaches and mixtures of approaches are available. For example, some features are optionally introduced as PCR products or “cut and pasted” from other available constructs. Typically, sequencing and/or other assays (e.g. size analysis, hybridization) are used to verify the resultant vector.
[0077] As an example, one section of the insert is created by synthesis of a region having a BamHI site and ending with an EcoRI site (“Synthetic — 1”). This region provides a transcriptional enhancer region, two LexA binding motifs, a rubisco transcriptional promoter (including the first intron of rbcS2), a YFP-Bcl-x L fusion protein, and a rubisco 3′UTR. The YFP and Bcl-x L coding regions were designed in this instance to reflect the preferred codon usage in algae.
[0078] Another region incorporated is prepared by high fidelity PCR and effectively provides the p300 (HAT) gene (“Genomic PCR”). Flanking the genomic PCR fragment are two additional regions prepared by synthetic DNA (“Synthetic — 2”). The region transcriptionally upstream of the p300 gene provides the LexA binding domain coding sequence downstream of transcriptional promoters and two LexA binding sites. The Synthetic — 2 region provides a 3′UTR. Combined, the Synthetic — 2 and Genomic regions create a complete transcription unit encoding a LexA-p300 fusion protein (GEE).
[0079] Effectively, FIG. 1 and these explanations provide an example of the features of a construct of the invention and illustrate methods of creating the features within an algae compatible plasmid. Two transcriptional units face opposing directions and each have two LexA binding sites, creating an opportunity for the LexA-p300 to bind at any of four sites and affect transcription levels of either transcriptional unit. A third transcriptional unit provides a selection marker, bleomycin-resistance.
[0080] It will be recognized by a skilled artisan that other design approaches are available, including the incorporation within the vector of additional or different genes incorporated for expression, different gene expression control features, other restriction sites, change the number of LexA-BS, and so on, without changing the concept behind the creation of this vector, namely to effectively increase the levels of expression of the genes located in vicinity of a DNA-BS, in the presence of a GEE that recognizes/binds the BS.
EXAMPLE 2
Additional Exemplary Vectors
[0081] Two vectors are constructed which are in most respects identical, but for the presence of a GEE unit. The vectors are otherwise the same to each other and similar to the vector of FIG. 2A . The use of these vectors in parallel allows testing of the p300 activity and the role of LexA in otherwise identical genetic backgrounds. The use of two vectors also allows for modulation of the GEE activities by such additional engineering, for example, as addition of other genes, addition of multiple copies of GEE and so on.
[0082] Notably, “LexA BS” does not refer to any limit of the number of binding sites; anything from one BS to many BS are possibly located at the indicated position. Practically speaking, it is unlikely to utilize more than about 8 BS, as benefit from additional sites would be unlikely. Preferably, about 2 to 6 BS are located in the region at or near the 5′ end of genes desirably expressed, more preferably there are 2-4 BS.
EXAMPLE 3
Characterization of GEE Efficacy with a Bidirectional Promoter
[0083] Experiment 1. Use the bidirectional construct with YFP reporter in the position of the GOI and either one of two variants of the GEE construct: [1] in which the LexA-p300 chimeric gene is driven in the opposite direction ( FIG. 1 ) or [2] in which only LexA is driven in the opposite direction which serves as a control.
[0084] Algae are transformed with the two constructs and selected on appropriate antibiotic containing selection media (e.g. media containing bleocin). After selection, 100 colonies from transformation for each construct are chosen to analyze the expression of the YFP transgene by assaying mRNA expression using rtPCR, protein expression with Western blot, and single cell fluorescence by flow cytometry and fluorescent microscopy. The clonal populations are passaged for 2, 4, 6, and 10 generations. The frequency of high-level expression of YFP are compared between the LexA-p300 and LexA only clones. The LexA-p300 GEE increases expression and maintains a higher level of nuclear transgene expression over time.
EXAMPLE 4
Characterization of GEE Efficacy Using Distinct Plasmids
[0085] Generate two sets of stable clones: Set one is a stable cell line with the incorporated transgene encoding the LexA-p300 fusion ( FIG. 2A ) that is then transformed with a plasmid that expresses the YFP vector ( FIG. 2B ). Set two is a stable cell line with the incorporated transgene encoding the LexA only (related to FIG. 2A with the exception of the p300 fusion partner) that is then transformed with a plasmid that expresses the YFP vector ( FIG. 2B ).
[0086] Select for stable cell lines and characterize the YFP expression over time by assaying mRNA expression by rtPCR, western blot to determine protein expression, and assay of single cell fluorescence by flow cytometry and fluorescent microscopy. The clonal populations will be passaged for 2, 4, 6, and 10 generations. Similarly, the frequency of high-level expression of YFP are compared between the LexA-p300 and LexA only clones. The LexA-p300 GEE increases expression and maintains a higher level of nuclear transgene expression over time.
[0087] The invention described above should be read in conjunction with the accompanying claims and drawings. The description of embodiments and examples enable one to practice various implementations of the invention and they are not intended to limit the invention to the preferred embodiment, but to serve as a particular example of the invention. Those skilled in the art will appreciate that they may readily use the conception and specific embodiments disclosed as a basis for modifying or designing other methods and systems for carrying out the same purposes of the present invention.
[0088] All references, including publications, patent applications, patents, and website content cited herein are hereby incorporated by reference to the same extent as if each reference were individually and specifically indicated to be incorporated by reference and was set forth in its entirety herein.
[0089] The websites mentioned herein were last visited on Oct. 30, 2010.
[0090] The use of the terms “a” and “an” and “the” and similar references in the context of describing the invention are to be construed to cover both the singular and the plural, unless otherwise indicated herein or clearly contradicted by context.
[0091] Recitation of ranges of values herein are merely intended to serve as a shorthand method of referring individually to each separate value falling within the range, unless otherwise indicated herein, and each separate value is incorporated into the specification as if it were individually recited herein. The word “about,” when accompanying a numerical value, is to be construed as indicating a deviation of up to and inclusive of 10% from the stated numerical value. The use of any and all examples, or exemplary language (“e.g. ” or “such as”) provided herein, is intended merely to better illuminate the invention and does not pose a limitation on the scope of the invention unless otherwise claimed. NO language in the specification should be construed as indicating any non-claimed element as essential to the practice of the invention. | The invention provides a system of enhancing the expression of transgenes in algae. Transgenes are engineered to have a binding site for certain proteins in proximity to their promoter, for example a LexA binding site. The algae is also engineered to express a nucleosome alteration protein fused to a protein with affinity to the DNA binding site acting in coordination. An example is a LexA-p300 fusion protein, where the p300 is derived from Chlamydomonas . The LexA binding domain guides the p300 to the binding site and the p300 loosens the nucleosome structure by acetylating histones within proximity of the transgene, thus remodeling the local chromatin structure to allow for high-level expression. | 2 |
BACKGROUND OF THE INVENTION
This invention relates to a die set for a coldwelding machine and more particularly to an improved, adjustable die set.
The normal coldwelding machine employed for welding pieces of wire or the like embodies two pairs of dies. Each pair of dies is movable between an opened position in which the workpiece may slide between the dies of the pairs and a closed position in which workpieces are gripped by the dies. When the workpieces are gripped by the pairs of dies, the pairs are moved toward each other from a spaced position to a welding position to effect an upset. The spacing between the dies of the pairs and between the pairs of dies in their opened positions is relatively critical. For example, it is normal practice to move the ends of the workpieces toward each other a distance approximately equal to twice the diameter of the wire being welded during each upset. Frequently a given set of dies is used for welding a range of wire diameters. Thus, when the diameter of the wire being welded is changed it is necessary to adjust the spacing between the pairs of dies. This has, heretofore, been accomplished by the use of removable spacers. Such an arrangement has obvious disadvantages. Considerable time is involved with making adjustments, additional parts are required and the possibility of error is introduced.
It is, therefore, a principal object of this invention to provide a die set for a coldwelding machine in which the spacing between the dies may be conveniently adjusted.
It is another object of the invention to provide an adjustable die set for a coldwelding machine.
It is a further object of the invention to provide an improved, adjustable die set for a coldwelding machine.
SUMMARY OF THE INVENTION
This invention is adapted to be embodied in a die set for a coldwelding machine that includes first and second dies. The dies have facing surfaces and are adapted to be used in a machine having means for moving the surfaces relative to each other. Adjustable stop means are interconnected to the dies and permit the dies to move relative to each other freely in a first direction and for adjustably limiting the degree of relative movement of the dies in the opposite direction.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a top plan view of an adjustable die set for a coldwelding machine embodying this invention.
FIG. 2 is a cross sectional view of the die set taken in the direction of the line 2--2 in FIG. 1.
FIG. 3 is a top view of one die of each of the pairs shown in FIG. 1 with portions broken away to show the adjustment between the dies.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
A die set for a coldwelding machine, which die set embodies this invention, is identified generally by the reference numeral 11. The die set 11 is comprised of a first pair of dies 12 and 13 and a second pair of dies 14 and 15. The dies 12, 13 and 14, 15 of the pairs are adapted to be moved toward and away from each other and the pairs of dies 12 and 13 and 14 and 15 are adapted to be moved toward and away from each other in a coldwelding sequence by a suitable coldwelding machine (not shown). The coldwelding machine may be of any of the known types embodying such dies. Examples of suitable machines may be used in conjunction with dies of the type disclosed herein are shown in U.S. Pat. Nos. 2,863,344 issued Dec. 9, 1958 in the name of William A. Barnes; 2,909,086 issued Oct. 20, 1959 in the name of William A. Barnes et al.; 2,909,951 issued Oct. 27, 1959 in the name of Walter J. Rozmus et al.; 2,932,221 issued Apr. 12, 1960 in the name of William A. Barnes et al.; 3,044,328 issued July 17, 1962 in the name of Stanley A. Zysk; 3,606,131 issued Sept. 20, 1971 in the name of Walter J. Rozmus or any of the other known machines of this type.
The dies 12 and 13 have facing surfaces 16 and 17 in which recesses are formed. In each recess is received a hardened insert 18 which insert is formed with a cavity 19 that is adapted to grippingly engage a wire, in a manner which will become more apparent as this description proceeds. The inserts 18 are held in each of the dies 12 and 13 by machine screws 21 or the like.
In a like manner, the dies 14 and 15 have facing surfaces 22 and 23 that are recessed to receive respective hardened inserts 24 in which cavities 25 are formed to receive the wire to be welded. The inserts 24 are held in place by machine screws 26.
The dies 12 and 14 are each formed with respective pairs of counterbored openings 27, 28 and 29, 31. Affixed to the dies 13 and 15 and extending from their respective faces 17 and 23 are pairs of pins 32, 33 and 34, 35. The pins 32 and 33 cooperate with the counterbores 27 and 28 to locate the dies 12 and 13 axially relative to each other while permitting free movement of the faces 16 and 17 toward and away from each other. In a similar manner, the pins 34 and 35 cooperate with the counterbored openings 29, 31 to locate the dies 14 and 15 axially relative to each other and to permit the faces 22 and 23 to move toward and away from each other.
An adjusting mechanism is provided between the dies 12, 14 and 13, 15 for holding respective facing surfaces 36, 37 and 38, 39 of these dies at an adjustably affixed distance. The adjusting mechanism, however, permits the faces 36, 37 and 38, 39 to move freely toward each other into abutting engagement. This adjusting mechanism may be best understood by reference to FIG. 3 wherein the mechanism associated with the dies 13 and 15 is illustrated in detail and is identified generally by the reference numeral 41.
The adjusting mechanism 41 comprises a pair of vertically spaced screws 42 each of which has a threaded terminal portion 43 that is received in a respective tapped opening 44 in the die 13. The portion of the die adjacent the face 38 is formed with a counterbore 45 that is concentric with the tapped opening 44. The die 15 is also formed with a complementary counterbore 46 that extends inwardly from its face 39 and which is aligned with the counterbore 45 of the die 13. A coil compression spring 47 encircles each of the screws 42 and is received within the respective counterbores 45 and 46 to urge the dies 13 and 15 away from each other. The springs 47 urge the dies to an opened position and this position is determined by a shoulder 48 formed at the base of the head 49 of each screws 42 with a corresponding shoulder 51 formed between a pair of bored openings 52 and 53 of of the die 15. The opening 52 extends between the counterbore 46 and the opening 53, with the latter opening receiving the head 49 of the screw 42.
Each screw head 49 is accessible through the outer face of the respective die 15 so as to permit its rotation by means of an allen wrench or similar tool. This rotation causes the screw threads 43 to advance or retract in the tapped openings 44 and adjust the open distance between the die faces 38 and 39. The adjusting mechanism 41, however, permits the dies 13 and 15 to move freely toward each other so that the die faces 38 and 39 can be brought into full engagement.
It is to be understood that the foregoing description is that of a preferred embodiment of the invention. Various changes and modifications may be made without departing from the spirit and scope of the invention as defined by the appended claims. | An adjustable die set for a coldwelding machine that is adjustable to facilitate its use with workpieces of varying dimensions. Specifically the die set includes pairs of dies having a screw threaded adjustable stop interconnecting them for adjusting the spacing between the dies. | 1 |
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims the benefit of U.S. Provisional Patent Application No. 60/467,988, filed May 2, 2003, which is hereby incorporated by reference in its entirety.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention relates to rail joints and, more particularly, to a rail joint having a rolled profiled bar.
[0004] 2. Description of Related Art
[0005] Railroad rails used in the railroad industry are typically formed of a plurality of railroad rail sections joined together by rail joints. As shown in FIG. 1 , a prior art rail joint 10 positioned between a first railroad rail 12 and a second railroad rail 14 is used to hold two ends 13 , 15 of the railroad rails 12 and 14 , respectively, in place. A plurality of holes 16 are defined in the rail joint 10 , wherein the holes 16 are adapted to receive fasteners, such as a bolt and nut arrangement, for securing the rail joint 10 to the railroad rails 12 , 14 . The rail joint 10 prevents lateral and/or vertical movement of the rail ends 13 , 15 of the railroad rails 12 , 14 and permits the longitudinal movement of the railroad rails 12 , 14 for expanding or contracting. Prior art rail joints have various strength requirements, as well as weight requirements set by the railroad industry. It is desirable to have a rail joint that is inexpensive to manufacture while having a maximum amount of strength for a minimum amount of weight per joint.
[0006] Further, due to technological advances in rail grinding and lubrication, present rail structures are lasting longer, thereby allowing more usable wear out of the rail heads than in the earlier constructed rail structures. This results in a decrease in distance between the rail head and a top portion of the rail joint, thus resulting in the possibility of the vehicle wheels contacting the rail joint, thereby causing premature failure of the rail joint. Therefore, it is an object of the present invention to overcome the above problems and to provide a strong rail joint that is inexpensive to manufacture.
SUMMARY OF THE INVENTION
[0007] The present invention provides for a rail joint made from a metallic bar that is rolled or forged. The rail joint includes a body having a length defined between a first end and a second end and defining a base section having a base front side and base back side, a web section having a web front side and a web back side, and a head section having a head front side and a head back side and defining an upper surface. The base section depends from the web section, and the web section depends from the head section. The web section of the body of the rail joint defines a plurality of holes for receiving fasteners. The head portion defines an abutting portion, an intermediate portion and a lug portion. A distance between the head front side and the head back side of the head section is greater than or equal to a distance between the base front side and the base back side of the base section. The strength of the rail joint as defined by the Moment of Inertia (I) is in a range of 14 to 15 in 4 and the weight of the rail joint is in a range of 1.5 to 1.65 pounds per inch of length of the rail joint.
[0008] The present invention also provides for a railroad rail assembly that includes a pair of abutting railroad rails and a pair of rail joints, as previously discussed, fastened to each side of the pair of railroad rails. A purpose of the present invention is to provide increased wheel flange clearance while maintaining the integrity of joining two rails together.
BRIEF DESCRIPTION OF THE DRAWINGS
[0009] FIG. 1 is a right side elevational view of a prior art rail joint connecting two adjacent railroad rails together;
[0010] FIG. 2 is a side elevational view of a rail joint made in accordance with the present invention;
[0011] FIG. 2 a is a side elevational view of the rail joint shown in FIG. 2 having dimension lines;
[0012] FIG. 3 is a top plan view, partially in section, of the rail joint shown in FIG. 2 ;
[0013] FIG. 4 is a right side elevational view, partially in section, of the rail joint shown in FIG. 2 ;
[0014] FIG. 5 is a left side elevational view, partially in section, of the rail joint shown in FIG. 2 ;
[0015] FIG. 6 is a bottom plan view, partially in section, of the rail joint shown in FIG. 2 ;
[0016] FIG. 7 is a front elevational view of a typical prior art railroad rail;
[0017] FIG. 8 is a side elevational view of the rail joint shown in FIG. 2 co-acting with a railroad rail;
[0018] FIG. 9 is a side elevational view of a rail joint assembly made in accordance with the present invention;
[0019] FIG. 10 is a side elevational view of a prior art rail joint profile; and
[0020] FIG. 11 is a side elevational view of the rail joint shown in FIG. 2 and prior art rail joint profiles co-acting with a railroad rail.
DETAILED DESCRIPTION OF THE INVENTION
[0021] The present invention provides for a rail joint 20 made from a metallic bar that is rolled or forged. The rail joint 20 can be made of steel or other metal. Referring to FIGS. 2-6 , the rail joint 20 includes a body 22 having a first end 24 and a second end 26 and defining a base section 28 , a web section 30 and a head section 32 . The base section 28 depends from the web section 30 , and the web section 30 depends from the head section 32 . The web section includes a web front side 34 and a web back side 36 and defines a plurality of holes 38 for receiving fasteners (shown in FIGS. 4 and 5 ). Referring to FIG. 2 , the base section 28 has a bottom surface 29 , a base front side 40 and a base back side 42 . The base section 28 also defines a heel portion 44 , a blended portion 46 , and a toe portion 48 . The heel portion 44 depends from the blended portion 46 , and the blended portion 46 depends from the toe portion 48 . The toe portion 48 extends away from the web front side 34 of the web section 30 and the heel portion 44 extends in an opposite direction from the toe portion 48 away from the web back side 36 of the web section 30 . The head section 32 has an upper surface 33 and includes a head front side 50 and a head back side 52 . The head section 32 defines an abutting portion 54 , an intermediate portion 60 and a lug portion 62 . The abutting portion 54 depends from the intermediate portion 60 , and the intermediate portion 60 depends from the lug portion 62 . The abutting portion 54 further defines a curved portion 56 and a straight portion 58 , wherein the curved portion 56 defines a contacting surface 59 . The lug portion 62 extends away from the web front side 34 of the web section 30 and the abutting portion 54 extends in an opposite direction from the lug portion 62 away from the web back side 36 of the web section 30 . A front recess area 64 is defined between the lug portion 62 of the head section 32 and the toe portion 48 of the base section 28 , and a back recess area 66 is defined between the abutting portion 54 of the head section 32 and the heel portion 44 of the base section 28 .
[0022] With continued reference to FIG. 2 , the specific design of the rail joint 20 provides the rail joint 20 with a maximum amount of strength for a minimum amount of weight. A distance L 1 between the head front side 50 and the head back side 52 of the head section 32 is greater than or equal to a distance L 2 between the base front side 40 and the base back side 42 of the base section 28 of the body 22 of the rail joint 20 . The lug portion 62 extends from the web front side 34 of the web section 30 a distance D 1 approximately equal to a distance D 2 the toe portion 48 extends from the web front side 34 of the web section 30 . Preferably, the distance D 1 is approximately within 0.125 inches or less of the distance D 2 . A recess 68 is defined between the abutting portion 54 and the lug portion 62 on the upper surface 33 of the head section 32 of the body 22 of the rail joint 20 . When the rail joint 20 is attached to a railroad rail, the recess 68 in the head section 32 is capable of receiving a wheel of a rail car riding on the railroad rail. The recess 68 preferably has a depth (D t ) that is sufficient to provide enough clearance for a wheel of a railcar riding on a railroad rail so as to prevent contact of the wheel on the lug portion of the head section of the body of the rail joint 20 . The depth (D t ) for a rail joint for uses in larger rails (i.e. 132-RE, 136-RE and 141-RE) of the recess 68 can be in a range of 0.6 to 0.8 inches and preferably is 0.631 inches, and the thickness of the lug portion D L is in a range of 0.35-0.50 inches, and preferably 0.40-0.47 inches.
[0023] Rail joint 20 can be used on any size or type of standard tee railroad rail 12 as shown in FIG. 7 . However, rail joint 20 is preferably used with 132-RE, 136-RE and 141-RE rails according to the American Railway Engineering and Maintenance Way Association (AREMA) specifications. Referring to FIG. 7 , railroad rail 12 that includes a body 72 having a head 74 , a web 78 , and a base 80 having an upper surface 82 . The head 74 having a top surface 76 is connected to the web 78 , which is connected to the base 80 . The web 78 defines a plurality of slots 84 (shown in phantom in FIG. 8 ) for receiving fasteners. A web recess 86 is defined between the head 74 and the base 80 on each side of the railroad rail 12 and a rail head recess 88 is defined between the head 74 and the web 78 on each side of the railroad rail 12 . The dimensions of the railroad rail 12 , designated by the letters A-H, can vary depending on the size and type of rail required for a particular need. For example, a railroad rail having the 136-RE designation weighs 136 pounds per yard and includes the following dimensions in inches as shown in FIG. 7 : Height (A) of railroad rail is 7{fraction (5/16)}; Width (B) of base 80 is 6; Width (C) of head 74 is 2{fraction (15/16)}; Thickness (D) of web 78 at center is {fraction (11/16)}; Depth (E) of head 74 is 1{fraction (15/16)}; Height (F) of web 78 is 4{fraction (3/16)}; Head angle (a) is 1 to 4 degrees; Base angle (a′) is 1 to 4 degrees; Slope (s) of head 74 is 1 to 40 degrees; and Height (H) of slot 84 is 3{fraction (3/32)}.
[0024] Referring to FIGS. 2-6 , it has been found that the specific shape and dimensions of the rail joint 20 results in improved strength characteristics when used with the preferred railroad rails. The strength of the rail joint 20 can be defined by the Moment of Inertia (I) and the Section Modulus (Z). “Moment of Inertia (I)” is defined as the capacity of a cross-section to resist bending, and can be expressed in inches to the fourth power (in 4 ). Section Modulus (Z) relates bending moment and maximum bending stress within the elastic range and can be expressed in inches to the third power (in 3 ). The “elastic range” is where the working stress does not exceed the elastic limit and the “elastic limit” is the maximum stress to which a structural member may be subjected and still return to its original length upon release of the load. Section Modulus (Z) can be expressed mathematically as: Z=I/c; wherein (I) is the Moment of Inertia of the cross-section about a neutral axis (N), and (c) is the distance from the neutral axis (N) to the outermost fibers.
[0025] The rail joint 20 when used with the preferred railroad rails (i.e., 132-RE, 136-RE and 141-RE) preferably has a length of 36 inches from the first end 24 to the second end 26 of the rail joint 20 and includes six holes 38 (partially shown in FIGS. 4 and 5 ) for receiving fasteners. Referring to FIG. 2 , the rail joint 20 preferably includes the following dimensions: Moment of Inertia (I) in a range of 14-15 in 4 (preferably 14.02-14.07 in 4 ); a top Section Modulus (Z) as defined from the neutral axis N to an upper end UE of the head section 32 in a range of 5.3-5.7 in 3 (preferably 5.54-5.57 in 3 ); and a bottom Section Modulus (Z) as defined from the neutral axis N to a bottom end BE of the base section 28 in a range of 5.3-5.7 in 3 (preferably 5.59-5.61 in 3 ). Preferably, the cross-sectional area is in a range of 5.6-5.7 in 2 (preferably 5.63-5.66 in 2) and the rail joint 10 has a weight in a range of 1.5-1.65 pounds per inch of length (preferably 1.59-1.60 pounds per inch). Preferably, the neutral axis N is about 2.53 inches from the upper end UE of the head section 32 and 2.51 inches from a bottom end BE of the base section 28 of the rail joint 20 .
[0026] The rail joint 20 when used with preferred smaller rails (i.e. 115-RE and 119-RE) preferably has a length of 36 inches from the first end 24 to the second end 26 of the rail joint 20 and includes six holes 38 (partially shown in FIGS. 4 and 5 ) for receiving fasteners. Referring to FIG. 2 , the rail joint 20 preferably includes the following dimensions: Moment of Inertia (I) in the range of 10-11 in 4 (preferably 10.24 in 4 ); a top Section Modulus (Z) in the range of 4.3-4.5 in 3 (preferably 4.44 in 3 ); the bottom Section Modulus (Z) 4.3-4.5 in 3 (preferably 4.45 in 3 ). Preferably, the cross-sectional area is in the range of 5.0-5.2 in 2 (preferably 5.12 in 2 ) and the rail joint 10 has a weight in a range of 1.4-1.5 pounds per inch of length (preferably 1.45 pounds per inch). Preferably, the neutral axis N is about 2.31 inches from the upper end UE of the head section 32 and 2.30 inches from the bottom end BE of the base section 28 of the rail joint 20 . The depth (D t ) of the recess 68 is within the range 0.550-0.700 inches and preferably 0.575 inches and the lug thickness D L is within a range of 0.35-0.45 inches, preferably 0.38-0.43 inches.
[0027] FIG. 2 a shows the rail joint 20 having dimensions designated as J1-J7. Table 1 shows the dimensions (J1-J7) of various size rail joints 20 along with the strength properties for the specific rail joint dimensions. The first two examples are for rail joints for railroad rails 132-RE, 136-RE and 141-RE. The last example is for a rail joint for railroad rails 115-RE and 119-RE. The dimensions are defined as follows: J1 is the length of the head section 32 from a central axis A; J2 is the length of the base section 28 from a central axis A; J3 is the height of the base section 28 ; J4 is the height of the head section 32 ; J5 is the distance from a neutral axis N to a top of the rail joint 20 ; J6 is the distance from a neutral axis N to a bottom of the rail joint 20 ; and J7 is the horizontal distance between central axis A and a longitudinal axis that first contacts the head section 32 . The strength properties include Moment of Inertia (I), top Section Modulus (Z) top , bottom Section Modulus (Z) bot , and weight in pounds per inch of length of the rail joint.
TABLE 1 J1 J2 J3 J4 J5 J6 J7 I Z top Z bot Weight (in) (in) (in) (in) (in) (in) (in) (in 4 ) (in 3 ) (in 3 ) (lbs/in) 2.747 2.879 1.260 1.327 2.53 2.51 0.405 14.04 5.55 5.60 1.60 2.747 2.879 1.260 1.217 2.53 2.51 0.405 14.02 5.54 5.59 1.59 2.624 2.624 1.150 1.241 2.31 2.30 0.378 10.24 4.44 4.45 1.45
[0028] FIG. 8 shows a rail joint arrangement 90 wherein rail joint 20 is attached to a railroad rail 12 . Referring to FIG. 8 , the base back side 42 of the base section 28 , the web back side 36 of the web section 30 , and the head back side 52 of the head section 32 of the body 22 of the rail joint 20 is received within the web recess 86 of the body 22 of the railroad rail 12 . The contacting surface 59 of curved portion 56 of the abutting portion 54 of the rail joint 20 abuts against a surface of the railroad rail 12 within the rail head recess 88 , thus defining a first fishing surface F 1 The bottom surface 29 of the base section 28 abuts against the upper surface 82 of the base 80 of the railroad rail 12 , thus defining a second fishing surface F 2 . By “fishing surface” is meant a surface where the rail joint 20 contacts a surface of a railroad rail. It has also been found that the rail joint 20 should be positioned a distance X between the top surface 76 of the railroad rail 12 and the upper surface 33 of the lug portion 62 in order to minimize the possibility of contact between rail wheels and the rail joint 10 . For example, the distance X is preferably, for larger rails, at least 2.0 inches, and, more preferably, 2.17 inches for a 132-RE rail, 2.37 inches for a 136-RE rail, and 2.52 inches for a 141-RE rail. The distance X is preferably, for smaller rails, at least 2.0 inches and, more preferably, 2.05 inches for a 115-RE rail and 2.24 inches for a 119-RE rail. It has been found that the present design maximizes Moment of Inertia (I) and minimizes weight of the rail joint 20 while providing additional wheel flange clearance over prior art rail joints resulting in a superior rail joint.
[0029] FIG. 9 shows a rail joint assembly 91 made in accordance with the present invention. Referring to FIGS. 8 and 9 , the assembly includes a pair of rail joints 20 , 20 ′, as previously discussed, attached to each side of a pair of abutting railroad rails 12 , 14 (shown in FIG. 1 ). A fastener 92 , such as a nut and bolt arrangement, passes through the hole 38 in rail joint 20 , slot 84 in railroad rail 12 , and a corresponding hole 38 ′ in rail joint 20 ′ and a nut 94 is received by the fastener 92 so as to attach the rail joints 20 , 20 ′ against each side of the adjacent railroad rail 12 .
[0030] FIG. 10 shows a prior art rolled rail joint 100 , resulting in a weaker rail joint 100 compared to rail joint 20 . The prior art rail joint 100 is similar to rail joint 20 , except for the differences noted below. Like reference numerals are used for like parts. The prior art rail joint 100 includes a body 22 having a base section 28 , a web section 30 , and a head section 32 . The shape of the web section 30 and the base section 28 of the prior art rail joint 100 are substantially similar to the web section 30 and base section 28 of rail joint 20 . The head section 32 of rail joint 100 also includes an abutting portion 54 , an intermediate portion 60 , and a lug portion 62 . However, the abutting portion 54 of rail joint 100 includes only a curved portion 56 and not a straight portion 58 as in rail joint 20 , thereby resulting in a weaker rail joint. Further, the distance D 1 the lug portion 62 of rail joint 100 extends outwardly relative to the toe portion 48 of the base section 28 is substantially less than the distance D 1 the lug portion 62 of rail joint 20 extends outwardly relative to the toe portion 48 .
[0031] FIG. 11 also shows other prior art rail joint profiles W, Y and Z (shown in phantom) attached to a railroad rail 12 . All of these joints are at least partially machined. Further, the shape of the head sections of the prior art rail joint profiles W, Y and Z, particularly the lug portions, does not extend as far as the lug portion 62 of rail joint 20 . The shape and dimensions of the present rail joint 20 are such that it can be rolled or forged, without any machinery, except for the bolt holes. This results in a stronger and less expensive rail joint having the same diameters of rail joints that are machined. The rail joint 20 begins with a forged billet that is rolled through various rolling stands resulting in the final profile, for example, steel having a minimum 125,000 psi tensile strength and a minimum 88,000 yield strength is preferred. Stronger steel having a higher tensile strength and higher yield strength can be used to compensate for resulting losses in mechanical properties of inertia and section modulus over prior art joints.
[0032] It will be readily appreciated by those skilled in the art that modifications may be made to the invention without departing from the concepts disclosed in the foregoing description. Accordingly, the particular embodiments described in detail herein are illustrative only and are not limiting as to the scope of the invention, which is to be given the full breadth of the appended claims and any and all equivalents thereof. | A rail joint made from a metallic profiled bar that is rolled or forged and is used for connecting adjacent railroad rails to each other. A purpose of the present invention is to provide increased wheel flange clearance while maintaining the integrity of joining two rails together. | 4 |
FIELD OF THE INVENTION AND RELATED ART
[0001] The present invention relates to an ink jet recording head capable of jetting ink, and an ink jet recording apparatus employing an ink jet recording head. Not only is the present invention applicable to an ordinary ink jet printer, but also, a copying machine, a facsimile machine having a communicating system, a wordprocessor having a printing portion, a multifunction recording apparatus capable of performing two or more of the functions of the preceding machines.
[0002] An ink container remains stationary during distribution, during a period in which a recording apparatus in which an ink container is held is not used, or the like situations. If an ink container which contains pigment ink is left stationary for a long period of time, the ink in the container sometimes becomes nonuniform in pigment concentration, in terms of the vertical direction, because the pigment in the ink has a tendency to agglomerate and sediment. Thus, if the pigment ink in an ink container is supplied from the ink container to an ink jet recording head while remaining in the above-mentioned condition, ink droplets jetted from the recording head are nonuniform in pigment concentration, making it possible that the image forming apparatus will yield inferior images.
[0003] One of the conventional solutions (solution in accordance with prior art) to the above-mentioned problem is as follows: Before a user mounts an ink container into a recording apparatus, the user is to manually shake the ink container in order to make the ink in the ink container uniform in pigment concentration by breaking up the agglomeration of pigment.
[0004] Japanese Laid-open Patent Application 2004-216761 discloses a solution to the above-mentioned problem, which is different from the preceding solution. In this case, a recording apparatus is of the serial scan type, and an ink container is mounted on the carriage of the recording apparatus. Thus, the pigment ink in the ink container is stirred by utilizing the inertia which occurs as the carriage is moved in the manner of scanning recording medium.
[0005] Further, if a recording apparatus in which an ink container is mounted is left unused for a long time after its usage, it is possible that the phenomenon that pigment in ink sediments will occur even in the ink passage which connects the ink container and ink jet recording head. As one of the solutions to this problem, some conventional ink jet recording apparatuses are designed to periodically carry out a recovery operation, that is, an operation for discharging the ink in the ink passage.
[0006] FIG. 23 shows one of the conventional ink jet recording cartridges 100 , which is an integrated combination of an ink container and an ink jet recording head. Although the cartridge 100 is provided with multiple ink passages, the number of which corresponds to the number of different colors in which the cartridge 100 is capable of printing, FIG. 23 , which is a sectional view of the cartridge 100 , shows only one ink passage. For descriptive convenience, the section of the ink passage, which extends from the ink inlet opening 105 to a bend 150 , will be called section O, and the section of the ink passage, which extends from the bend 150 to bend 160 , will be called section P. Further, the section of the ink passage, which extends from the bend 160 to a liquid chamber 108 will be called section Q.
[0007] The cartridge 100 has an internal ink storage space 154 , and an ink passage 106 . The ink passage 106 outwardly extends from the internal ink storage space 154 , and is positioned so that when the cartridge 100 is in use, the ink passage 106 extends vertically downward. The ink intake opening 105 of the ink passage 106 , which is the interfacial portion between the ink storage space 154 and ink passage 106 , is fitted with a filter 104 . Further, a substantial portion of the ink storage space 154 is filled with an ink absorbing member 103 , which absorbs and internally retains pigment ink 102 . The ink passage 106 is shaped like a crank, having two bends, which are the bends 150 and 160 , at which the ink passage 106 bends 90 degrees. The ink passage 106 is in connection with the liquid chamber 108 , which is on the inward side of a heat radiating member 109 , with a joint rubber 107 fitted around the joint between the ink passage 106 and liquid chamber 108 . The heat radiating member 109 is provided with a heater board 110 , which is fixed to the heat radiating member 109 with the use of unshown adhesive. The heater board 110 is provided with driving elements and ink jetting orifices, which are not shown. The heater board 110 and heat radiating member 109 make up an ink jet recording head 151 .
[0008] The pigment ink 102 is supplied from the ink absorbing member 103 to the liquid chamber 108 through the ink intake opening 150 and ink passage 106 , and is temporarily stored in the liquid chamber 108 . The recording head 151 jets the pigment ink 102 from the ink jetting orifices by applying the energy generated by the driving elements, to the pigment ink. As the pigment ink 102 is supplied to the liquid chamber 108 , the ambient air enters the ink storage space 154 of the cartridge 100 to compensate for the volumetric loss which could occur to the ink storage space 154 as the pigment ink 102 is supplied from the ink absorbing member 103 , were it not for the entry of the ambient air into the ink storage 154 .
[0009] Normally, as the cartridge 100 is left unused for a certain length of time, the pigment ink in the ink passage 106 and liquid chamber 108 becomes nonuniform in pigment concentration, creating such a pigment concentration gradient that the pigment concentration is lower on top side in terms of the vertical direction, and higher in the bottom portion. Therefore, after the cartridge 100 is left unused for a certain length of time, the pigment concentration gradient of the pigment ink 102 in these sections is such that the section O of the ink passage is lower in pigment concentration and the section Q of the ink passage is higher in pigment concentration. Further, in each of the sections O and Q, the top side is lower in pigment concentration and the bottom side is higher in pigment concentration. The pigment concentration gradient (which hereafter may be referred to as “ink density”) of the ink in the horizontal section P, or the section which connects the sections O and Q, is such that the ink density gradually reduces from the bend 150 , or the border between the sections O and Q, toward the bend 160 , or the border between the section Q and P. As for the density of the body of ink in the section P, which is measured at a given cross-sectional plane of the section P, it is lower in the top side, in terms of the vertical direction, and higher in the bottom side, as it is in the sections O and Q. The reason why the ink density gradient (pigment concentration gradient) changes as described above with the elapse of time is that the pigment is easily affected by gravity, and therefore, is likely to sediment. If the ink in the above described condition is supplied to the recording head 151 to form images, images which are nonuniform in density are formed.
[0010] The manner in which the pigment in ink sediments is affected by the type of pigment and the solvent density. In a cartridge which is holding such ink that is high in pigment sedimentation speed, the pigment concentration is rather high in the liquid chamber 108 . Further, in the liquid chamber 108 , the portion directly under the ink passage 106 is different in ink density (pigment concentration) from the peripheries thereof; in other words, even in the horizontal direction, the pigment ink is nonuniform in density. In some cases, there is a difference of no less than two levels, in terms of an ordinary ink density measurement scale, between the portion of the ink, which is highest in density, and the portion of the ink, which is lowest in density.
[0011] Therefore, the abovementioned recovery operation is carried out at a preset interval with the use of a recovery cap with which the recording apparatus is provided. This recovery operation is an operation in which the bubbles and high viscosity ink (ink having increased in viscosity while recording head is left unused) in the recording head 151 are discharged to maintain the ink jetting performance of the recording head 151 at a preset level or higher, and also, to remove the portions of the body of ink in the recording head 151 , which have become excessively deviant in density. In the recovery operation, the recovery cap is pressed upon the recording head 151 of the cartridge 100 to hermetically seal the space surrounded by the recovery cap and recording head 151 , and then a suction pump connected to the recovery cap is driven to suction out the ink in the ink passage 106 through the ink jetting orifices of the recording head 151 . In this recovery operation, the body of ink, which is on the downstream side of the filter 104 , is discharged.
[0012] As described above, if it is only the recovery operation that is employed to abolish the nonuniformity in the ink density in the ink passage 106 , the recovery operation must be very frequently carried out. Further, in the recovery operation, the body of ink, which is significantly nonuniform in density, is removed by discharging the entire body of ink, which is in the section of the ink passage 104 , which is on the downstream side of the filter 104 . Therefore, the amount by which ink is removed by the recovery operation (amount by which ink is wasted) is substantial, and accordingly, the recording apparatus must be provided with a larger waste ink absorbing member, that is, a waste ink absorbing member, the capacity of which matches the substantial amount by which the ink is wasted. Thus, it is possible that the employment of this method of abolishing the abovementioned excessive nonuniformity in the ink density by the recovery operation will require the main assembly of the recording apparatus to be increased in size.
[0013] The cartridge 100 , which is a multicolor cartridge, that is, a cartridge capable of forming multicolor images, is more complicated in the shape of the ink passages 106 than a monochromatic, that is, a cartridge dedicated to monochromatic printing. Therefore, the cartridge 100 is greater in the number of sections of the ink passage 106 , which are affected by the pigment sedimentation, being therefore greater in the frequency with which the recovery operation has to be carried out, than a monochromatic cartridge. Moreover, the ink passages of the cartridge 100 are generally longer than the ink passage of a monochromatic cartridge, and therefore, the cartridge 100 is greater in the amount by which ink is discharged in the recovery operation than a monochromatic cartridge.
SUMMARY OF THE INVENTION
[0014] The present invention was made in consideration of the above described reasons, and its primary object is to provide an ink jet recording head and an ink jet recording apparatus, which are capable of efficiently removing the sedimented ink ingredients.
[0015] According to an aspect of the present invention, there is provided an ink jet recording head for ejecting, through an ink ejection outlet, ink introduced through an ink supply port, comprising a first ink flow path in fluid communication with the ink supply port; a second ink flow path which is branched from said first ink flow path at a branch portion and which is in fluid communication with said ink ejection outlet; and a third ink flow path for fluid communication between said branch portion and an outside.
[0016] According to the present invention, the ink passage is structured so that the ingredients of pigment ink primarily sediment into the third section of the ink passage through the first section of the ink passage, and the body of ink in the third section of the ink passage, that is, the body of ink, into which the ingredients of pigment ink have sedimented, is removed from the third section. Therefore, the body of ink, into which the ingredients of pigment ink have sedimented, can be efficiently discharged. Thus, the present invention can reduce the amount by which ink must be discharged to eliminate the sedimented ink ingredients. Therefore, not only can the present invention reduce the operational cost of an ink jet recording apparatus, but also, can reduce in volume the waste ink absorbing member for absorbing the discharged ink, making it possible to reduce in size an ink jet recording apparatus.
[0017] These and other objects, features, and advantages of the present invention will become more apparent upon 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
[0018] FIG. 1 is a sectional view of the ink jet recording cartridge, in the first embodiment, which is an integral combination of a recording head and an ink container (or containers).
[0019] FIG. 2 is an enlarged sectional view of the essential portions of the cartridge shown in FIG. 1 .
[0020] FIG. 3 is a perspective view of a typical ink jet recording apparatus in which the cartridge shown in FIG. 1 is mountable.
[0021] FIG. 4 is a sectional view of the cartridge shown in FIG. 1 , and the recovery cap for the cartridge.
[0022] FIG. 5 is a sectional view of the recovery caps for the cartridge shown in FIG. 1 , and the essential portions of the cartridge, which are involved in the recovery operation, showing one of the steps in the recovery operation.
[0023] FIG. 6 is an enlarged sectional view of the valve mechanism shown in FIG. 5 .
[0024] FIG. 7 is a sectional view of the recovery cap for the cartridge shown in FIG. 1 , and the essential portions of the recording head of the cartridge, which are involved in the recovery operation, showing another step in the recovery operation.
[0025] FIG. 8 is a sectional view of the recovery cap for the cartridge shown in FIG. 1 , and the essential portions of the cartridge, which are involved in the recovery operation, showing the state of the cartridge, in which the two recovery caps are kept pressed on the cartridge.
[0026] FIG. 9 is a sectional view of the ink jet recording cartridge, in the second embodiment, which is an integral combination of a recording head and an ink container (or containers).
[0027] FIG. 10 is a sectional view of the cartridge and recovery cap shown in FIG. 9 .
[0028] FIG. 11 is a sectional view of the recovery cap for the cartridge shown in FIG. 9 , and the essential portions (ink passage) of the cartridge, which are involved in the recovery operation, showing one of the steps in the recovery operation.
[0029] FIG. 12 is a sectional view of the recovery cap for the cartridge shown in FIG. 9 , and the essential portions of the cartridge, which are involved in the recovery operation, showing another step in the recovery operation.
[0030] FIG. 13 is a sectional view of the ink jet recording cartridge, in the third embodiment, which is an integral combination of a recording head and an ink container (or containers).
[0031] FIG. 14 is a sectional view of the cartridge and recovery cap shown in FIG. 13 .
[0032] FIG. 15 is a sectional view of the recovery cap for the cartridge shown in FIG. 13 , and the essential portions (ink passage) of the cartridge, which are involved in the recovery operation, showing one of the steps in the recovery operation.
[0033] FIG. 16 is a sectional view of the recovery cap for the cartridge shown in FIG. 13 , and the essential portions of the cartridge, which are involved in the recovery operation, showing another step in the recovery operation.
[0034] FIG. 17 is a sectional view of the ink jet recording cartridge, which is an integral combination of a recording head and an ink container (or ink containers), and the recovery cap, in the fourth embodiment.
[0035] FIG. 18 is an enlarged sectional view of the point of the ink passage, at which the ink passage branches, and the adjacencies of this branching point.
[0036] FIG. 19 is a view of the ink passage shown in FIG. 18 , as seen from the direction indicated by an arrow mark F in FIG. 18 .
[0037] FIG. 20 is a sectional view of the ink jet recording cartridge, which is an integral combination of a recording head and an ink container (or ink containers), and the recovery cap, in the fifth embodiment.
[0038] FIG. 21 is a view of the ink passage shown in FIG. 20 , as seen from the direction indicated by an arrow mark I in FIG. 20 .
[0039] FIG. 22 is a schematic sectional view of an ink jet recording head, and an ink container separable from the ink jet recording head, showing their structures which make them separable.
[0040] FIG. 23 is a sectional view of an ink jet recording cartridge, in accordance with the prior art, which is an integral combination of a recording head and an ink container (or ink containers).
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0041] Hereinafter, the preferred embodiments of the present invention will be described with reference to the appended drawings.
Embodiment 1
[0042] FIG. 1 shows an ink jet recording cartridge 1 , in the first embodiment of the present invention, which is an integral combination of an ink jet recording head and one or more ink containers. The ink jet cartridge 1 in this embodiment has: an internal ink storage space 54 ; an air vent 11 which connects the internal ink storage space 54 and the ambient air; an ink passage which extends outward from the ink storage space 54 ; and an ink jet recording head 51 . The ink passage is provided with an ink intake opening 5 , which leads to the ink storage space 54 . The ink intake opening 5 is provided with a filter 4 . There is an ink absorbing member 3 in the ink storage space 54 , and the ink absorbing member 3 absorbs and internally holds pigment ink 2 .
[0043] In this embodiment, the ink passage has: a section 6 (first ink passage section), which is in connection with the abovementioned ink intake opening 5 ; a section 6 B (section on ink jet recording head side: second section) which branches from the section 6 at a branching point R, and connects to the abovementioned ink jet recording head 51 ; a section 6 A (section on ink ingredient sediment recovery means side: third section), which leads outward. When the cartridge 1 is in the operational attitude (in this embodiment, “operational attitude” is an attitude in which cartridge 1 is after being mounted so that direction in which ink is jetted from its ink jetting orifices is vertically downward), the section 6 A extends vertically downward from the branching point R, and the section 6 B horizontally extends from the branching point R, bends 90 degrees at a bend 50 , and extends vertically downward to the liquid chamber 8 . The liquid chamber 8 is on the inward side of a heat radiating member 9 , which is in connection with the cartridge 1 , with the presence of a joint rubber 7 between the cartridge 1 and heat radiating member 9 . The heat radiating member 9 is provided with a heater board 10 , which is one of the components of the ink jet recording head 51 . The ink jet recording head 51 in this embodiment is made up of the heat radiating member 9 and heater board 10 . The section 6 B of the ink passage leads into the liquid chamber 8 through the internal passage of the joint rubber 7 . The bottom end of the section 6 A is sealed by a valve mechanism 53 to prevent ink from leaking therefrom. The valve mechanism 53 is made up of: a ball 15 ; a coil spring 16 ; and a ball seat 17 upon which the ball 15 is kept pressed to hermetically seal the interface between the ball 15 and ball seat 17 .
[0044] Incidentally, in this embodiment, the ball seat 17 is an integral part of a plug 18 ; the two components are integrally formed by two-color injection molding. The ball seat 17 has a through hole, the axial line of which coincides with the axial line of a through whole S with which the plug 18 is provided. The plug 18 is formed of the same substance as the substance of which the cartridge 1 is formed. The plug 18 is attached to the cartridge 1 by ultrasonic welding, with the presence of no gap between the cartridge 1 and plug 18 .
[0045] FIG. 2 shows the condition in which the bodies of ink in the sections of ink passage in areas A, B, and C of the cartridge 1 will be after the cartridge 1 is left unused (undisturbed) for a certain length of time after being mounted into the main assembly of the recording apparatus. The area A includes the section 6 of the ink passage, which extends from the ink intake opening 5 to the branching point, and the section 6 A which extends from the branching point to the outlet. The area B is the section of the ink passage which extends from the branching point to the bend 50 . The area C includes the section 6 B of the ink passage, which extends from the bend 50 to the liquid chamber 8 , and the liquid chamber 8 . The pigment concentration gradient in the area A is such that the pigment concentration is lower (low concentration) on the top side in terms of the vertical direction, and higher (high concentration) on the bottom side. The pigment concentration gradient of the ink in the area C is the same as that in the area A. In the area B, which is the horizontal area which connects the areas A and C, the pigment concentration gradient is such that the pigment concentration gradually reduces from the branching point R toward the bend 50 , that is, from the area A toward the area C. Further, the pigment concentration gradient of the body of ink in the area B, which is measured at a given plane perpendicular to the axial line of the ink passage, is the same as those in the areas A and C, that is, lower (low concentration) on the top side in the vertical direction, and higher (high concentration) on the bottom side. A pigment concentration gradient of ink, such as the above described one, occurs because the pigment sedimentation is greatly affected by gravity.
[0046] Referring to FIG. 1 , in this embodiment, the ink passage section 6 branches at the branching point R into two passages, that is, the passage (section) 6 A, and the passage (section) 6 B which is perpendicular to the passage (section) 6 A. The section 6 A extends vertically downward from the branching point R, making it easier for the pigment in the ink in the section to sediment. The section 6 A is provided with the valve mechanism 53 , which is made up of the ball 15 , coil spring 16 , and ball seat 17 , as described above.
[0047] FIG. 3 is a perspective view of a recording apparatus 70 in which the cartridge 1 is mountable, and shows the general structure of the recording apparatus 70 . The recording apparatus 70 is a recording apparatus of the serial scan type, which has a pair of guiding shafts 71 and 72 , and a carriage 73 on which the cartridge 1 is mountable. The carriage 73 is supported by the pair of guiding shaft 71 and 72 , being enabled to move in the primary scan direction indicated by an arrow mark A. The carriage 73 is reciprocally moved in the abovementioned primary scan direction by a driving force transmitting mechanism made up of a carriage motor, a belt for transmitting the driving force of the carriage motor, etc. A sheet of paper P as a medium on which recording made is inserted into the main assembly of the recording apparatus 70 through a recording medium inlet 75 located on the front side of the apparatus main assembly, and is conveyed by a recording medium conveyance roller 76 through the apparatus main assembly in the secondary scan direction indicated by an arrow mark B. Before the leading edge of the paper P reaches the cartridge 1 on the carriage 73 , the paper P is curved so that the leading portion of the paper P move in the opposite direction from the direction in which the paper P is inserted into the apparatus main assembly.
[0048] An image is formed in sections on the paper P by alternately repeating the recording operation and conveying operation. In the recording operation, the recording head 1 is made to jet ink toward the printing area of the paper P on a platen 7 , while moving the carriage 1 , on which the cartridge 1 is borne, in the primary scan direction. In the conveying operation, the paper P is conveyed in the secondary scan direction by a distance equal to the width of each section of the image which is being recorded each time the carriage 1 is moved in the primary direction during the recording operation. The recording apparatus 70 is provided with a recovery cap mechanism 52 , which is positioned at the left end of the moving range of the carriage 73 , shown in FIG. 3 , so that when the carriage 73 is at the left end of its moving range, the recovery cap mechanism opposes the surface of the recording head 51 of the cartridge 1 on the carriage 73 , which has the opening of each ink jetting orifice.
[0049] The pigment ink 2 is supplied from the ink absorbing member 3 to the ink chamber 8 through the ink intake opening 5 and ink passage sections 6 and 6 B, and is temporarily stored in the ink chamber 8 . The recording head 51 jets the pigment ink 2 through its ink jetting orifices by applying to the pigment ink the ink jetting energy which it generates by its driving elements. The ink jetting energy can be supplied with the use of an electrothermal transducer (heater), a piezoelectric element, or the like. When an electro-thermal transducer is employed, the ink is made to boil by the heat generated by the electro-thermal transducer, and the energy generated by the boiling of the ink is used to jet the ink from the ink jetting orifices of the recording head 51 . As the pigment ink is supplied to the recording head 51 as described above, the cartridge 1 takes in the ambient air through its air vent 11 to compensate for the void which would be created in the ink absorbing member 3 as the pigment ink 2 is supplied from the ink absorbing member 3 , if the ambient air were not taken in.
[0050] FIG. 4 is an enlarged sectional view of the recovery cap mechanism 52 used in the recovery operation, which is an operation for recovering the performance of the recording head 51 by suctioning out the ink in the recording head 51 , and its adjacencies, and shows the structure of the recovery cap mechanism 52 . The recovery cap mechanism 52 has a pair of caps 12 and 19 , which are in connection with a suction pump. The cap 12 is for suctioning out the ink in the cartridge 1 through the ink jetting orifices of the recording head 51 . The cap 19 is for suctioning out the ink in the cartridge 1 through the section 6 A of the ink passage. The cap 19 has a sealing member 20 , which is for sealing the joint between the bottom end of the ink passage section 6 A and the cap 19 . The cap 19 is also provided with a projection 21 which projects beyond the top surface of the cap 19 , which comes into contact with the cartridge 1 . The cap 12 is provided with a discharge hole 13 , which is in connection with a discharge tube 14 .
[0051] Next, the operation for recovering the performance of the cartridge 1 by suctioning out the ink in the cartridge 1 will be described. It is assumed that before the recovery operation is carried out, the cartridge 1 has been left unused (undisturbed) for a long time, and therefore, the pigment in the bodies of ink in the areas A, B, and C of the cartridge 1 has sedimented. It is the bottom portion of the area A that has become highest in the pigment concentration. There are pigment particles which have accumulated in this portion of the area A. In the recovery operation, therefore, ink is suctioned out from this portion, or the bottom portion of the area A.
[0052] Referring to FIG. 5 , next, the cap 19 is pressed on the cartridge 1 so that the sealing member 20 is placed hermetically in contact with the area of the bottom surface of the cartridge 1 , which surrounds the bottom opening of the section 6 A of the ink passage. During this step, the projection 21 of the cap 19 enters the section 6 A beyond the plug 18 and ball seat 17 , while pushing up the ball 15 . As a result, the ball 15 is separated from the ball seat 17 , creating a gap, between the ball 15 and ball seat 17 , through which ink can flow.
[0053] The cap 19 is in connection with an unshown suction pump (vacuum pump) to generate negative pressure in the cap 19 . Next, referring to FIG. 6 , as the suction pump is driven, the ink in the section 6 A is suctioned into the cap 19 . That is, the body of ink in the bottom portion of the section 6 A, into which the pigment particles have sedimented, is suctioned in the direction indicated by an arrow mark T. The amount by which the ink is suctioned out can be optimized, and also, minimized, by setting the amount according to the length of time the recording apparatus has been continuously left unused. After the preset amount of ink is suctioned out, the cap 19 is separated from the cartridge 1 .
[0054] Referring to FIG. 7 , next, the cap 12 is pressed upon the recording head 51 , whereby the space surrounded the recovery cap 12 and recording head 51 is hermetically sealed. The discharge tube 14 of the cap 12 is in connection with an unshown suction (vacuum) pump. As soon as the cap 12 becomes connected to the recording head 51 , the suction pump is driven to suction out ink from the recording head 51 by an amount large enough to remove the sedimented ink ingredients and the lingering bubbles in the areas B and C. As ink is suctioned out of the recording head 51 , it is discharged outward from the cap 12 through the discharge hole 13 and discharge tube 14 , and then, is sent to the waste ink absorbing member in the recording apparatus. As soon as the process of suctioning ink out of the recording head 51 is completed, the cap 12 is retracted (separated) from the recording head 51 (cartridge 1 ).
[0055] The caps 12 and 19 are placed in contact with, or separated from, the cartridge 1 by a mechanical driving means in the recording apparatus. In this embodiment, the caps 12 and 19 can be advanced toward, or retracted from, the cartridge 1 , independently from each other. In other words, the caps 12 and 19 are individually driven.
[0056] In this embodiment, the body of high density ink (high in pigment concentration) in the area D shown in FIG. 5 , that is, the body of ink into which the pigment has sedimented, is discharged by suctioning the ink in the cartridge 1 through the ink passage sections 6 and 6 A (for convenience, this process may be simply stated as “process of suctioning ink from ink passage section 6 A”). Then, the bodies of ink in the areas B and C, which are high in density (pigment concentration) and contain the bubbles, are removed by suctioning the ink in the cartridge 1 through the ink passage section 6 and 6 B (for convenience, this process may be referred to as “process of suctioning ink from ink passage 6 B”). The amount by which ink is to be suctioned out when removing the ink in the section 6 B has only to be just enough to remove the sedimented ink ingredients in the areas B and C, because the sedimented ink ingredients in the area A are removed before the ink in the section 6 B is suctioned out. Therefore, unlike in the past, it is unnecessary to remove all the ink in the areas on the downstream side of the filter 4 . In other words, compared to the amount by which ink has to be suction out according to the prior art, the amount by which ink has to be suction out of the ink cartridge 1 in this embodiment is smaller by an amount equal to the amount of ink in the top portion of the area A, that is, the body of ink which does not need to be removed, because the pigment had not sedimented in this body of ink. Therefore, this embodiment is smaller in the amount of waste ink, and therefore, the waste ink absorbing member in the recording apparatus may be smaller. Thus, this embodiment makes it possible to reduce the recording apparatus in size.
[0057] Described below are the sequential steps in the recovery operation for removing the sedimented ink ingredients with the use of the cap 19 .
[0058] 1) The sealing member of the cap 19 is pressed on the plug 18 to hermetically seal the space surrounded by the sealing member 20 , and the area of the bottom surface of the cartridge 1 , which is next to the bottom opening of the ink passage section 6 A.
[0059] 2) The projection 21 which extends from within the sealing member 20 reaches beyond the opening S of the plug 18 , and comes into contact with the ball 15 .
[0060] 3) The cap 19 is to be pressed hard enough for the projection 21 to push upward the ball 15 away from the ball seat 17 .
[0061] 4) Negative pressure is generated in the cap 19 to suction ink by a preset amount in the direction indicated by an arrow mark T.
[0062] 5) After the removal of the preset amount of ink, the cap 19 is moved in the direction (downward) to remove the pressure applied to the cartridge 1 by the cap 19 .
[0063] Incidentally, in the above described embodiment, ink is suctioned out of the ink passage section 6 A while keeping the cap 12 pressed upon the cartridge 1 , and thereafter, ink is suctioned out from the ink passage section 6 B while keeping the cap 19 pressed upon the cartridge 1 . However, it is acceptable to suction ink out of the ink passage section 6 A while keeping both the caps 12 and 19 pressed upon the cartridge 1 , and thereafter, suction ink out of the ink passage section 6 B. Shown in FIG. 8 is the state of the cartridge 1 and caps 12 and 19 , in which both caps 12 and 19 are kept pressed upon the cartridge 1 to keep hermetically sealed the spaces surrounded by the caps 12 and 19 and the corresponding areas of the cartridge 1 . In this case, when ink is suctioned out of the ink passage section 6 A with the use of the cap 19 , the sedimented ink ingredients in the area D can be more efficiently suctioned out, because the ink jetting orifices of the recording head 51 are kept sealed by the cap 12 . After ink is suctioned out of the ink passage section 6 A as shown in FIG. 8 , the cap 19 is separated from the cartridge 1 as shown in FIG. 7 . Then, the ink in the areas B and C are suctioned out through the cap 12 (by generating negative pressure in the cap 12 ).
Embodiment 2
[0064] Next, referring to FIGS. 9-12 , the second preferred embodiment of the present invention will be described. Incidentally, the components in this embodiment, which are identical to the counterparts in the first embodiments are given the same referential symbols as those given to the counterparts, and will not be described; only the components in this embodiment, which are not identical to the counterparts in the first embodiment, or not present in the first embodiment, will be described. In this embodiment, a heat radiating member 23 , which is the counterpart of the heat radiating member 9 in the first embodiment, is provided with a through hole 24 . Further, a sealing member 22 in this embodiment is made wider than the sealing member 22 in the first embodiment, and also, is shaped so that it can seal between the heat radiating member 9 and cartridge 1 around both the openings of the ink passage sections 6 A and 6 B. An ink jet recording head 55 , or the ink jet recording head in this embodiment, is structured to be compatible with the heat radiating member 23 . The employment of this structural arrangement makes it possible to eliminate the plug 18 , which was necessary in the first embodiment. Thus, it can eliminate the process for welding the plug 18 to the cartridge 1 .
[0065] Shown in FIG. 10 are a cap 25 , that is, the cap in this embodiment, used for the recovery operation, and the recording head 55 .
[0066] The cap 25 is an integral combination of the caps 12 and 19 used in the first embodiment. The cap 25 has a projection 26 which projects from the inward side of the sealing member 20 . Incidentally, the projection 26 , which is equivalent to the projection 21 used in the first embodiment, is longer than the projection 21 , by the length equal to the thickness of the heat radiating member 23 . Further, the cap 25 has two ink passage sections 56 A and 56 B, through which ink is suctioned out. The two ink passages sections 56 A and 56 B of the cap 25 correspond to the ink passage sections 6 A and 6 B of the cartridge, respectively. The ink passage sections 56 A and 56 B are separated by a three way valve U. The provision of the three way valve U between the two ink passage sections 56 A and 56 B of the cap 25 makes it possible to switch between the two ink passage sections 56 A and 56 B when suctioning ink.
[0067] FIG. 11 shows the state of the cap 25 and recording head 55 , in which the recovery operation is being carried out, with the cap 25 kept pressed on the recording head 55 so that the spaces formed by placing the cap 25 in contact with the recording head 55 remains hermetically sealed. As the cap 25 is pressed on the recording head 55 hard enough to keep the abovementioned spaces hermetically sealed, the projection 26 causes the ball 15 to separate from the sealing member 22 . In the recovery operation in this embodiment, first the three way valve U is turned so that the ink passage section 6 A becomes connected to the ink suctioning side, and the ink in the area A is suctioned out. In this step of the recovery operation, the body of ink in the area A, that is, the body of ink, in which the sedimentary ink ingredients had accumulated, is removed.
[0068] Next, referring to FIG. 12 , the three way value U is turned to connect the ink passage section 6 B to the side from ink is suctioned, while keeping the cap 25 pressed on the recording head 55 . Then, the bodies of ink in the areas B and C are suctioned out, whereby the sedimented ink ingredients are removed from the areas B and C, and also, the bubbles lingering in the ink passage section 6 B are removed.
[0069] The cap 25 , that is, the recovery cap in this embodiment, is more complicated than the recovery caps in the first embodiment. However, the cap 25 is an integral combination of the two caps 12 and 19 required in the first embodiment. In other words, the cap 25 replaces the two caps 12 and 19 which were required in the first embodiment. Therefore, the employment of the cap 25 makes it unnecessary to individually advance or retract multiple (two) caps; only one cap driving means, that is, the driving means for driving the cap 25 , is necessary. Further, the cap 25 has to be advanced once and retracted once per recovery operation. Therefore, this embodiment is smaller in the number of times a capping means has to be driven (number of times cap 25 has to be driven) per recovery operation. Therefore, this embodiment is smaller in the amount of the load for driving the cap than the first embodiment.
Embodiment 3
[0070] Next, referring to FIGS. 13-16 , the third embodiment of the present invention will be described. Incidentally, the components in this embodiment, which are identical to the counterparts in the first or second embodiment are given the same referential symbols as those given to the counterparts, and will not be described; only the components in this embodiment, which are not identical to the counterparts in the first or embodiment, or not present in the first or second embodiment, will be described. In this embodiment, a slidable pin 27 is provided in place of the ball 15 employed in the second embodiment. The slidable pin 27 is made up of a ball portion, such as the ball 15 in the second embodiment, and a projection portion, such as the projection 26 in the second embodiment. Thus, the valve mechanism is opened or closed by the slidable pin 27 .
[0071] FIG. 14 shows a cap 28 , that is, a cap in this embodiment, will be described. The cap 28 is provided with a plate 29 which comes in contact with the slidable pin 27 . As the cap 28 is pressed on a recording head 57 , which is a recording head in this embodiment, to hermetically seal the space formed between the cap 28 and recording head 57 , the plate 29 presses on the slidable pin 27 , causing thereby the slidable pin 27 to be separated from the sealing member 22 . The plate 29 is rigid enough not to deform when it presses on the slidable pin 27 .
[0072] The recover operation in this embodiment, which uses the cap 28 , is the same as the recovery operation in the second embodiment. FIG. 15 shows the state of the cartridge 1 and cap 28 , in which the ink is being suctioned out of the ink passage section 6 A in order to suction out the body of ink in the area D, which is high in pigment concentration. After the body of ink in the area D is suctioned out, the three way valve U is turned to connect the ink passage section 6 B to the side toward which ink is suctioned out, and the bodies of ink in the areas B and C are suctioned out to continue the recovery operation as shown in FIG. 16 .
[0073] In this embodiment, unlike the cap 19 , that is, the cap in the first or second embodiment, the cap 28 does not need to be provided with a projection ( 21 ). It is only the plate 29 , or the plate which comes into contact with the valve mechanism, that the cap 28 needs to be provided. Therefore, this embodiment is simpler in terms of the shape of the recovery cap ( 28 ) than the second embodiment.
Embodiment 4
[0074] Next, referring to FIGS. 17-19 , the fourth embodiment of the present invention will be described. This embodiment is different from the third embodiment in that the ink passage sections 6 , 30 , and 31 of the cartridge 1 in this embodiment, which correspond to the ink passage sections 6 , 6 A, and 6 B of the cartridge 1 in the third embodiment, are inclined. The section 6 branches into the sections 30 and 31 at a branching point G (sections 6 and 30 will be together referred to as section 30 , for convenience) in the area E. The section 31 leads into the liquid chamber 8 . The section 30 is the ink passage section in into which the pigment easily sediments, and which is provided with a valve mechanism, which is located at the bottom end of the section 30 . FIG. 18 is an enlarged view of the area E shown in FIG. 17 , which is the adjacency of the branching point G.
[0075] Both the ink passage sections 30 and 31 are inclined relative to the vertical direction. The ink passage section 31 , which branches from the section 30 , is greater in inclination angle, relative to the vertical direction, than the section 30 . FIG. 19 is a view of the internal wall of the ink passage, as seen from the direction indicated by an arrow mark F in FIG. 18 . It is evident from FIG. 19 that the ink passage section 30 is tubular and the section 31 branches out from the portion of the internal wall of the ink passage section 30 at the branching point G, in such a manner that the border line between the ink passage sections 30 and 31 curves as if the ink passages 30 were intact. Thus, the section 31 is not visible in the area of the drawing, which corresponds to the internal space of the section 30 . Based on the knowledge of the inventors of the present invention, in order to enhance the sedimentation of the pigment into the ink passage 30 , it is desired that a branching point G 2 shown in FIG. 18 is not on the valve mechanism side of the center line H of the ink passage section 6 (left side of center line H in FIGS. 17-19 ). That is, it is desired that the recording head 57 is structured so that the border line between the ink passage portions 30 and 31 does not intersect with the center line of the ink passage section 30 , nor is on the valve mechanism side of the center line. Pigment sediments in the direction of gravity. Therefore, structuring the cartridge 1 as described above make is possible to guide the pigment into the section 30 as the pigment sediments, while making it harder for the pigment to enter the section 31 . In this embodiment, it is desired that the cartridge 1 is structured so that the border line between the ink passage sections 30 and 31 is on the recording head side of the center line H (right-hand side of center line H in FIGS. 17-19 ).
[0076] The double-dot chain line in FIG. 18 is for describing the case in which the cartridge 1 is structured so that a part of the section 31 is visible in the internal area of the ink passage section 30 , as the ink passage section 30 is seen from the direction indicated by the arrow mark F, and also, so that the branching point G is on the recording head side (right-hand side) of the center line H of the section 30 of the ink passage. Also in this case, the cartridge 1 is structured so that the border line between the ink passage sections 30 and 31 is on the recording head side (right-hand side) of the center line H of the section 31 and does not intersect with the center line H. Pigment sediments in the direction of gravity. Therefore, structuring the cartridge 1 as described above makes it possible to guide the pigment into the section 30 of the ink passage as it sediments, making it therefore harder for the pigment enters the section 31 of the ink passage as it sediments.
Embodiment 5
[0077] Next, referring to FIGS. 20 and 21 , the fifth embodiment of the present invention will be described.
[0078] In this embodiment, the ink passage 6 of the cartridge 1 bifurcates into sections 32 and 33 . More specifically, the sections 33 branches out from the section 32 of the ink passage at a bifurcation point J, and leads into the liquid chamber 8 . The ink passage section 32 is the section, into which the pigment can more easily sediment than the section 33 . The section 32 is provided with a valve mechanism, which is located at the bottom end of the section 32 .
[0079] FIG. 21 is a drawing of the sections 32 and 33 of the ink passage, which are seen from the direction indicated by an arrow mark I in FIG. 20 . The section 32 of the ink passage is tubular. The section 33 of the ink passage branches from the section 32 of the ink passage, at the branching point J, which is on the recording head side of the center line H of the section 32 . Based on the knowledge of the inventors of the present invention, in order to promote the sedimentation of pigment into the section 32 , it is desired that the branching point J is on the recording head 59 side of the center line H of the section 32 . That is, it is desired that the cartridge 1 is structured so that the border line between the ink passage sections 32 and 33 does not cross the center line H. From the standpoint of ensuring that the pigment sediments into the section 32 of the ink passage, setting the position of the branching point J as described above is effective, and is more effective than adjusting the angle at which the ink passage section 6 bifurcates into the sections 32 and 33 . Pigment sediments in the direction of gravity. Therefore, structuring the cartridge 1 as described above makes it possible to guide the pigment into the section 32 of the ink passage while the pigment is sedimenting, making it harder for the pigment to enter the section 33 of the ink passage.
Miscellaneous Embodiments
[0080] Incidentally, in each of the above described preferred embodiments of the present invention, the present invention was applied to the ink jet recording cartridge, which is an integral combination of an ink cartridge (or ink cartridges) and an ink jet recording head. However, these embodiments are not intended to limit the present invention in scope. That is, the present invention is also applicable to an ink jet recording cartridge structured so that its ink jet recording head and ink container are separable from each other.
[0081] FIG. 22 is a sectional view of a recording head in accordance with the present invention, which is independent from an ink container, and shows the structure of the recording head. The structure of this recording head is the same as the structure of the recording head portion of the ink jet recording cartridge 1 shown in FIG. 1 , except that an ink container 101 , that is, the ink container for this recording head, is removably attachable to the recording head. Therefore, the structure of this recording head will not be described in detail.
[0082] Also in each of the above described preferred embodiments of the present invention, it was pigment ink (ink which contains pigment) that was jetted from the recording head. However, the liquid to be jetted from the recording head does not need to be ink; it may be liquid other than ink. Also in each of the above described embodiments, it was the pigment in ink that was discharged through the section(s) of the ink passage, which branched from the primary section of the ink passage. However, the ingredient(s) in ink, which is to be discharged, may be ingredients other than the pigment. Further, in each of the above described preferred embodiments, the recording apparatus was an ink jet recording apparatus. However, the present invention is applicable to recording apparatuses other than an ink jet recording apparatus. Further, the recording apparatus was of the serial scan type. However, the present invention is applicable to a recording apparatus of the full-line type, just as well.
[0083] 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.
[0084] This application claims priority from Japanese Patent Application No. 148841/2006 filed May 29, 2006 which is hereby incorporated by reference. | An ink jet recording head for ejecting, through an ink ejection outlet, ink introduced through an ink supply port includes a first ink flow path in fluid communication with the ink supply port; a second ink flow path which is branched from the first ink flow path at a branch portion and which is in fluid communication with the ink ejection outlet; and a third ink flow path for fluid communication between the branch portion and an outside. | 1 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a waterproof structure for a charging connector and, in particular, to a waterproof structure for a charging connector which is used in an apparatus such as an electric car requiring a charging operation.
2. Description of the Prior Art
Conventionally, in carrying cars used in physical distribution and the like, as well as in electric cars which have attracted public attention in recent years, there is provided in a suitable portion of the car body thereof a charging connector which is a connecting means for charging. Such a charging connector includes a waterproof cap which prevents the entrance of water or dust when not in use so as to prevent generation of a leak or the like. Also, to prevent the charging connector from projecting out from the vehicle body, there is employed a structure in which the charging connector is disposed in a recessed portion of the vehicle body.
Especially, in a waterproof structure for a charging connector when the charging connector is used outdoors (for example, in an electric car or the like), because there is a high possibility that water can enter, a body cover (a cover which forms the outer surface of the car body and can be freely opened and closed) provided on the car body surface side can be used to prevent entrance of water and dust to some degree. There is also provided a waterproof cap in the connecting opening of the charging connector, thereby providing a double waterproof and dustproof structure.
In this type of waterproof structure for a charging connector, for example, as shown in FIG. 7, a waterproof cap 2 is connected to charging connector 1 by means of a chain 3. When not in use (when a charging operation is not preformed), a user fits the waterproof cap 2 into the connecting opening of the charging connector 1, thereby preventing entrance of water and dust. The charging connector 1 is conveniently disposed within a recessed portion 8 and the opening of the recessed portion 8 can be opened and closed by use of a body cover 7. In a different example of the conventional waterproof structure, as shown in FIG. 8, the waterproof cap 2 is arranged such that it can be swung, by means of a pin 4, around a bracket 6 provided in the side portion of the connecting opening of the charging connector 1. Further, for example, one end of a torsion spring 5 wound around the pin 4 is engaged with the bracket 6, and the other end thereof is engaged with the waterproof cap 2. The waterproof cap 2 can be always closed by the force of the torsion spring when a charging operation is not performed. In addition, the cover is closed by the body cover 7.
If the body cover 7 is inadvertently left open, this can be immediately discovered by an operator. Therefore it is unlikely that the operator will forget to close the body cover. However, especially in the structure shown in FIG. 7, if the body cover 7 is closed when the waterproof cap 2 for closing the opening of the charging connector 1 is forgotten to be closed, then the connector is not sealed in a waterproof manner. That is, rainwater and dust can enter the charging connector 1, which results in the failure of the charging connector 1. In this case, to prevent the failure to close the waterproof cap 2, for example, the chain 3 may be extended such that, when the waterproof cap 2 is removed, the cap 2 can be moved out of the recessed portion. In this structure, when the operator tries to close the body cover 7 without closing the waterproof cap 2, then the chain 3 or waterproof cap 2 will be nipped by the body cover 7, which tells the operator that the operator has forgotten to close the waterproof cap 2.
However, even the above-mentioned structure still has a drawback that it requires a troublesome operation to push the excessive portion of the chain into the interiors of the body cover 7. That is, in this structure, even when the waterproof cap 2 is incompletely closed, if the body cover 7 is closed, then it is impossible to confirm the incompletely closed condition of the waterproof cap 2 from the outside.
Also, as shown in FIG. 8, in the structure of the type that the waterproof cap 2 is always forced toward the closing of the charging connector 1 by torsion spring 5, when charging is completed and a charging plug is then removed from the charging connector 1, the waterproof cap 2 is closed automatically. Therefore, there is no possibility that the operator forgets to close the waterproof cap 2.
However, in the charging operation, the operator must open the waterproof cap 2 with one hand to keep the cap in an opened state, while holding a charging plug with the other hand and fitting it with the charging connector 1. This requires operations to be performed clumsily with both hands. Also, in the waterproof cap 2 of this type, if the waterproof cap 2 and charging connector 1 are tightly fitted with each other for perfect waterproofing and dustproofing, then there arises a condition in which the waterproof cap 2 cannot be closed completely by the force of the torsion spring 5. It can also be expected that the force of the torsion spring 5 would be greatly increased. However, an extreme increase in the force reduces the operator's ability to open the waterproof cap 2.
As described above, in the structure shown in FIG. 8, because the fitting between the charging connector 1 and waterproof cap 2 must be relatively loose, the inherent function of the waterproof cap 2 cannot be performed fully, resulting in a structural problem.
SUMMARY OF THE INVENTION
In view of the above-mentioned, the invention aims at eliminating the drawbacks found in the conventional waterproof structures for a charging connector. Accordingly, it is an object of the invention to provide a waterproof structure for a charging connector which is simple, allows for efficient operation, prevents a failure to close a waterproof cap, and is sure to be able to protect the charging connector against water and dust.
In attaining the above object, according to the invention, there is provided a waterproof structure for a charging connector including a body cover for opening and closing the opening of a recessed portion formed in a portion of a vehicle body and a waterproof cap for covering a charging connector provided in the recessed portion, wherein the waterproof cap is openably and closably supported in the neighborhood of a connecting opening of the charging connector, the waterproof cap is arranged such that it can be switchingly energized in its closing and opening directions, and, when the body cover is moved in its closing direction, the waterproof cap is pressed by the body cover, thereby closing the connecting opening of the charging connector.
Also, the above object of the invention can also be accomplished by a structure in which the switchable moving of the waterproof cap in its closing and opening directions can be generated by a cam surface disposed around the axis of the support portion of the waterproof cap and an elastic member disposed to be contactable with the cam surface, or by a structure in which a pressure member for elastically pressing against the waterproof cap in its closing direction while the body cover is being closed is provided inside of the body cover or outside of the waterproof cap, or by a structure in which the waterproof cap and body cover are connected with each other by a connecting member and the waterproof cap can be opened and closed in linking with the opening and closing movements of the body cover.
According to the above-mentioned waterproof structure of the invention, the waterproof cap is maintained in its opened state by the force of an elastic member such as a leaf spring and the like acting on the cam surface when the cap is opened; on the other hand, when it is situated on the charging connector, the waterproof cap is energized in its closing direction by the action of the elastic member acting on the cam surface; and, while the body cover is closed, the waterproof cap is pressed in its closing direction by the inside of the body cover. That is, the present structure assures to close the waterproof cap completely and thus assures to waterproof and dustproof the charging connector perfectly.
Also, according to the structure of the invention, even if an operator forgets to close the waterproof cap, by means of an operation to close the body cover, the body cover presses down the waterproof cap. Thus, the waterproof cap is automatically closed on the charging connector because of the action of the leaf spring. This insures that the waterproof cap will be fully closed.
Further, according to the structure in which a link member is interposed between the waterproof cap and body cover, the waterproof cap can be opened in linking with an operation to open the body cover. Also, according to the structure in which an elastic member is interposed between the body cover and waterproof cap, the waterproof cap can be pressed elastically by the elastic member to thereby insure that the waterproof cap will be fully closed.
BRIEF DESCRIPTION OF THE DRAWINGS
The present invention is illustrated in the following drawings, in which:
FIG. 1 is a schematic horizontal section view of a first embodiment of a waterproof structure according to the invention;
FIG. 2 is an explanatory view of the action of a leaf spring on the cam portion of the waterproof cap in the respective opening and closing angles of the waterproof cap employed in the first embodiment of the invention;
FIG. 3 is an explanatory view of the action of a leaf spring on the cam portion of the waterproof cap in the respective opening and closing angles of the waterproof cap employed in the first embodiment of the invention;
FIG. 4 is an explanatory view of the action of a leaf spring on the cam portion of the waterproof cap in the respective opening and closing angles of the waterproof cap employed in the first embodiment of the invention;
FIG. 5 is a schematic section view of the structure of a locking elastic projection provided in the waterproof cap to be fitted into a securing hole formed in a charging connector;
FIG. 6 is a schematic horizontal section view of a second embodiment of a waterproof structure according to the invention;
FIG. 7 is a perspective view of a conventional waterproof cap; and
FIG. 8 is a perspective view of another conventional waterproof cap.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Description will be given hereinbelow of an embodiment of a waterproof structure for a charging connector according to the invention with reference to FIGS. 1 to 5.
FIG. 1 is a schematic horizontal section view of a first embodiment of a waterproof structure using a waterproof cap according to the invention. FIGS. 2 to 4 are respectively explanatory views of the action force of a leaf spring to be applied to a cam portion of the waterproof cap in the respective opening and closing angles of the waterproof cap, and FIG. 5 is a section view of the structure of a locking elastic projection which is provided in the waterproof cap and is fittable into a securing hole formed in the charging connector.
In FIG. 1, a recessed portion 13 is formed in a portion of a vehicle body 11 and an opening formed in the recessed portion 13 can be opened and closed by a body cover 12 which is pivotally mounted to the edge of the recessed portion. In the recessed portion 13, there is disposed a charging connector 21 in such a manner that it can be projected out according to cases and, in close proximity to the charging connector 21, a waterproof cap 31 is mounted which can be opened and closed in the same direction in which the body cover 12 is opened and closed.
A bracket 25 is provided on the side portion of the charging connector 21 and a pin 23 is fitted with the bracket 25. The waterproof cap 31 can be swung around the pin 23 and includes a cam portion 31a having a cam surface which is formed in a suitable shape. A leaf or leaf spring 24, which has a substantially V- or U-shaped side surface, is mounted on a flange portion 26 of the charging connector 21 and is arranged such that it is contactable with the cam portion 31a.
Although a connecting terminal is actually disposed within the charging connector 21, the illustration thereof is omitted here.
Description will now be given below of the operation to be performed by the cam portion 31a and leaf spring 24.
When the waterproof cap 31 is fully opened (see FIG. 2), the force of the leaf spring 24 is applied toward the pin 23 or toward the cam leading end side (upper side in FIG. 2) rather than the pin according to the contact conditions between the waterproof cap 31 and the cam portion 31a, so that the waterproof cap 31 is kept open.
When the waterproof cap 31 is closed from its open state, in the beginning of the closing operation thereof, the waterproof cap 31 receives from the leaf spring 24 a force which repels the closing operation. As shown in FIG. 3, when the waterproof cap 31 is slightly closed, the leaf spring 24 acts on the next contact portion (in the drawings, the surface that is most remote from the pin) of the cam portion 31a, thereby increasing the spring force to some extent. However, since the direction of action thereof extends in the direction of the pin 23, little force is being applied to the waterproof cap 31 in the opening and closing directions thereof. That is, this is a balanced intermediate state in which the direction of force of the leaf spring 24 can be switched between the opening and closing directions. It should be noted that such an intermediate state as shown in FIG. 3 occurs in a very narrow range in the middle of the opening and closing operation; that is, it is just a metastable state.
On the other hand, in such a state as shown in FIG. 4 in which the waterproof cap 31 is closed, the force of the leaf spring 24 acts around the pin 23 to close the waterproof cap 31. As a result of this, the waterproof cap 31 receives a force in a direction to bring a waterproof packing 32 attached to the inside of the waterproof cap 31 into close contact with the charging connecter 21.
Also, the waterproof cap 31 includes an elastic projection 33 for locking on the opposite side to the mounting side thereof, so that the projection 33 is projected inwardly of the cap 31 and is engageable into a securing hole 22 formed on the charging connector 21 side thereof. Due to this, when the waterproof cap 31 is closed, the locking elastic projection 33 is fitted into the securing hole 22. This enables the waterproof cap 31 to be secured in its closed state, and makes it possible for a user to recognize that the waterproof packing is surely closed according to an elastic sound or a response occurring when the projection 33 is inserted into the securing hole 22.
The locking elastic projection 33, as shown in FIG. 1, may be simply projected internally of the waterproof cap 31. Alternatively, the elastic projection 33 may be arranged as shown in FIG. 5. A projection 33a and a spring 33b are inserted into a cylinder 33c and the cylinder 33c is then covered with a spring storing cover 33d to form one united structure. The one united structure is threadedly engaged with, for example, the internal thread portion of the waterproof cap 31.
To open the waterproof cap 31, a knob 34 provided on the outer surface of the cap 31 can be pulled by hand. On the other hand, to close the waterproof cap 31, the waterproof cap 31 may be pressed by hand and, alternatively, since the knob 34 can be brought into contact with the inner surface of the body cover 12, the waterproof cam 31 can be closed completely only by closing the body cover 12. That is, even when a user happens to forget to close the waterproof cap 31 or the waterproof cap 31 is incompletely closed, the waterproof cap 31 is pushed down and closed in an operation to close the body cover 12. In addition, when the body cover 12 is closed, the upper end portion of the knob 34 is pressed by the inner surface of the body cover 12, thereby completely preventing the waterproof cap 31 from failing to close. The knob 34 is mounted in a cantilever manner and, therefore, it can be provided with proper elasticity.
Next, description will be given below of a second embodiment of a waterproof structure for a charging connector according to the invention with reference to FIG. 6.
FIG. 6 is a schematic horizontal section view of a second embodiment of a waterproof structure using a waterproof packing according to the invention. In the second embodiment, the same components thereof as in the first embodiment are given the same designations respectively, and thus the description thereof is omitted here.
Within the body cover 12 there is provided an elastic member 41 having suitable size. When the waterproof cap 31 is closed on the charging connector 21 and the body cover 12 is closed, then the elastic member 41 pushes against the waterproof cap 31 to thereby close the charging connector 21 positively, whereby the charging connector 21 can be waterproofed and dustproofed.
A structure is employed in which a point distant from the center of swing of the waterproof cap 31 is linked with a suitable point existing within the body cover 12 by a link member 51. The link member 51 includes a hinge in the middle stage thereof and links the above-mentioned two points with each other. Further, in the elastic member 41, there is formed a groove which is adapted to receive the link member 51, so that the link member 51 and elastic member 41 do not interfere with each other when the body cover 12 is opened and closed. However, when the elastic member 41 and link member 51 are provided at their respective positions where they do not interfere with each other, the above-mentioned groove is not necessary.
With this structure, if the body cover 12 is opened, then the link member 51 pulls and opens the waterproof cap 31 to thereby be able to connect a feeder line with the charging connector 21 immediately, so that the workability of the structure can be improved to a great extent.
Although, in the first and second embodiments, description is omitted of a structure for securing the body cover 12 in its closed state, of course, it is preferred to arrange the body cover 12 such that it can be secure with the recessed portion 13 thereof closed. However, this structure is not limited to a special one but various structures can also be 10 employed.
Also, the present invention is not limited to the above-mentioned embodiments at all but, for example, various charges in the shape and arrangement of the leaf spring, cam portion, waterproof cap, elastic member and the like may be resorted to without departing from the spirit of the invention or the scope of the subjoined claims.
As has been described heretofore, according to the invention, when the waterproof cap is opened, it can be maintained in the open state. On the other hand, when it is positioned on the charging connector, the waterproof cap is pushed in its closing direction. Also, when the body cover is closed, the waterproof cap is pushed in its closing direction by the inside of the body cover. This makes it possible to close the waterproof cap completely and thus to protect the charging connector from water and dust. Also, even when a waterproof cap closing operation is forgotten, by means of an operation to close the body cover, the body cover pushes down the waterproof cap, thereby closing the waterproof cap automatically. Therefore, the invention is sure to prevent a failure of the closing of the waterproof cap. | The waterproof structure for a charging connector includes a body cover for opening and closing the opening of a recessed portion formed in a vehicle body, and also includes a waterproof cap for covering a charging connector arranged to project from the bottom surface of the recessed portion. The waterproof cap is journalled openably and closably near a connecting opening formed in the charging connector, and a cam surface is provided around the axis of the journalled portion of the waterproof cap. The waterproof cap can be switchingly moved in its opening and closing directions by an elastic member contactably disposed with the cam surface. When the body cover is closed, then the waterproof cap is pushed by the body cover, thereby closing the connecting opening of the charging connector. | 8 |
FIELD OF THE INVENTION
[0001] The present invention relates to safety viewing devices for motor vehicles.
BACKGROUND OF THE INVENTION
[0002] Among related prior art includes U.S. Pat. No. 4,758,078 of Bracamonte, which describes an upwardly extendable motor vehicle mirror used to view beyond visually obstructive vehicles, such as SUVs and vans.
[0003] However, in Bracamonte '078, the driver can only see far away. There is a blind spot in the area directly beside the rear of an SUV or van, such as where a small child or shopping cart or other obstruction such as a closely passing vehicle might be located.
[0004] In contrast, there is a need for a rearview mirror, which is rearwardly extendable from the rear light area, clearly exposing anything immediately behind the adjacent SUV or van, which is a feature not attainable with the upwardly extending mirror of Bracamonte '078.
OBJECTS OF THE INVENTION
[0005] It is therefore an object of the present invention to provide a view to the motor vehicle driver of conditions in both directions along the traffic lane in addition to the area directly behind the vehicle, which is normally visible.
[0006] It is also an object of the present invention to provide a visual aid which helps a driver to safely back into a traffic lane from a parking place, wherein the visual images are derived from a vantage point just beyond the rear periphery of the vehicle.
[0007] It is also an object of the present invention to provide a visual aid which clearly shows vehicular or pedestrian traffic in close proximity to a danger zone in the vicinity of a motor vehicle and beyond
[0008] It is further an object of the present invention to provide a visual aid for providing a rear view which is also visible in the reflection from the rear view mirror.
[0009] Other objects will become apparent from the following description of the present invention.
SUMMARY OF THE INVENTION
[0010] In keeping with the aforementioned objects and others which may become apparent, the present invention provides a view to the driver of conditions in both directions along the traffic lane in addition to the area directly behind the vehicle which is normally visible. This visual aid helps a driver to safely back into a traffic lane from a parking place. The visual images are derived from a vantage point just beyond the rear periphery of the vehicle. This visual information, which clearly shows vehicular or pedestrian traffic in close proximity to the danger zone and beyond, is presented within the normal viewscape of a driver turned around and peering through the rear vehicle window as he or she prepares to back out. The visual image presented is also visible in the reflection from the rear view mirror. For some impaired drivers with limited range of motion of their torso, this is the only rear viewscape they have while backing up. This is becoming a more prevalent condition as the driving population ages. The visual aids of this invention are of particular benefit to low vehicles obscured on both sides by high vehicles (such as trucks, sport utility vehicles (SUV's), or vans) parked alongside.
[0011] While the invention can be built into a motor vehicle, the preferred embodiment of this invention is designed to be easily installed as an aftermarket accessory. It is attached to the rear license plate holder and has its own primary batteries as a power supply within a compact housing that also contains a mechanism and controls to deploy or store a mirror upon radio command from a small transmitter within the passenger compartment of the vehicle. The mirror has two slightly concave reflecting surfaces placed at right angles to each other and attached to the end of a telescoping rod such as to place the mirror such that it can be easily seen by the driver through the rear window when deployed. The reflections from the mirror surfaces are oriented so that views of the traffic lane in both directions are provided simultaneously. The vehicle should be slowly backed out just parallel or slightly beyond the longest vehicle parked alongside to gain maximum advantage from the view provided prior to backing out completely into the traffic lane. In two related variations of this embodiment, the primary batteries are replaced with rechargeable batteries in one version. They are charged intermittently every time the brake lights are operated by tapping into the brake light lines which are normally available at the rear of the vehicle. In another variation, the radio communications is replaced by a slender fiber optic cable which is snaked into the passenger compartment from the rear housing through a trunk or window and discreetly routed to the driver's area to terminate in a simple control box containing a light emitting diode (LED), battery and push button switch.
[0012] In another similar embodiment also attached to the rear license plate holder, the telescoping mirror is deployed vertically and a single mirror surface is used. In this case, the entire deployment mirror assembly is rotatable by a second motor so as to orient the mirror to view first one direction and then the other direction along the traffic lane.
[0013] For vehicles that have a robust car top carrier attached, a simpler embodiment is provided. A two surface mirror is attached at the end of an extending arm that is attached in a fixed fashion to the car top carrier. While perhaps not aesthetically pleasing, it is a simple inexpensive solution that is compatible with many SUV's, station wagons, or small commercial delivery vehicles.
[0014] For inclusion as a factory-provided accessory on new vehicles, a deployable embodiment of this invention can be totally hidden in the rear roof structure (until used) or can be stored in a streamlined bulge in the roof structure. The mirror, which is now hinged so that both surfaces can be stored flat, is pushed out of the roof on a telescoping rod and hinged down on a short arm to deploy in clear view of the rear window.
[0015] Another embodiment that is designed for simple aftermarket installation attaches the mirror accessory to the rear window opposite the driver side. This will work on most sedans, station wagons and SUV's. The accessory actually straddles the glass on the rear window with the folded two-surface deployable mirror in a flat housing on the outside while the drive motor and control relays are on the inside of the window. The window is moved up to seal the opening with gaskets provided to prevent wind noise or infiltration. For deployment, the mirror is extended rearward from the open end of the flat housing, and then at the end of the stroke a short arm positions it in view of the rear window. Since there is ready communication with the vehicle interior with this embodiment, it is easily powered by plugging into the cigarette lighter outlet and is controlled via hard wire with a simple two pushbutton control pod.
[0016] A final embodiment, with variations, uses a two-camera closed circuit video system with a flat panel display screen configured as a split screen. The display pops down from the ceiling at the rear window when needed and folds flat with the ceiling when not in use. The cameras can be mounted in a fixed position on brackets on the rear bumper facing sideways in opposite directions. For inclusion as original equipment on a new vehicle, the two cameras are attached to an arm which deploys out of a covered hatch in the trunk lid upon command.
BRIEF DESCRIPTION OF THE DRAWINGS
[0017] The present invention can best be understood in connection with the accompanying drawings. It is noted that the invention is not limited to the precise embodiments shown in drawings, in which:
[0018] FIG. 1 is a Top view of parked vehicles with approaching traffic using a visual aid of this invention.
[0019] FIG. 2 is a Perspective view of a two-surface mirror of this invention.
[0020] FIG. 3 is a Rear view of vehicle with deployed mirror of the preferred embodiment of this invention.
[0021] FIG. 4 is a Perspective view of internal major components of the preferred embodiment.
[0022] FIG. 5 is a Block diagram of the preferred embodiment of this invention.
[0023] FIG. 6 is a Side view of an alternate embodiment of this invention using a mirror with one reflecting surface.
[0024] FIG. 7 is a Side view of a van with a fixed mirror embodiment of this invention.
[0025] FIG. 8 is a Rear view of van with fixed mirror embodiment.
[0026] FIG. 9 is a Rear view of vehicle with roof mounted embodiment of this invention in stored position.
[0027] FIG. 10 is a Side view of vehicle with roof mounted embodiment in deployed position.
[0028] FIG. 11 is a Side view of vehicle with rear window mounted embodiment of this invention showing both stored and deployed positions.
[0029] FIG. 12 is a Rear view of vehicle with rear window mounted embodiment in deployed position.
[0030] FIG. 13 is a Schematic diagram of rear window mounted embodiment showing use of two automotive relays for control.
[0031] FIG. 14 is a Top view of two-camera arm assembly used with video system embodiment of this invention.
[0032] FIG. 15 is a Side view of vehicle rear quarter illustrating deployment of camera arm from hatch in trunk lid as used in video system embodiment.
[0033] FIG. 16 is a Interior rear view of vehicle equipped with video system embodiment of this invention.
DETAILED DESCRIPTION OF THE INVENTION
[0034] FIG. 1 shows the overall geometry of a car equipped with the display feature of this invention in a “helicopter” type of view. Vehicle 1 is attempting to back out of a parking space between SUV 2 and van 3 . A two-surface mirror 11 (shown more clearly in FIG. 2 ) is positioned in direct view of driver 6 via view line 9 or in a reflected view from rear view mirror 7 via view line 10 . Vehicle 1 is backed up part way by distance 4 so as to roughly line up 5 with the longer adjacent vehicle 3 . Approaching vehicle 13 via image ray 15 is viewable on one side of mirror 11 through rear window 8 . Simultaneously, approaching vehicle 12 is visible as an image the other side of mirror 11 via image ray 14 . Neither of these approaching vehicles would be visible to driver 6 except for the images presented by mirror 11 due to his restricted view of the traffic lane through all vehicle windows in this position.
[0035] The two-surface mirror of FIG. 2 has two reflecting surfaces, 20 and 21 , which are preferably slightly concave so as to intercept a wider view (similar in concept to the side view mirror distal to the driver). Surfaces 20 and 21 are preferably at right angles to each other with the sighting line 22 permitting a simultaneous view of both surfaces. For some embodiments, mirror 11 is designed with a hinge 23 joining surfaces 20 and 21 with spring bias from a torsion spring (not shown) to place the surfaces at right angles to each other. A light force inward at hinge 23 will permit mirror surfaces 20 and 21 to flatten out into a planar configuration.
[0036] The two adjacent mirror surfaces 20 and 21 form an angle ranging from greater than 0 degrees up to about 120 degrees, such as between 45 and 90 degrees, preferably 90 degrees, and a connecting means of connecting the mirror surfaces 20 and 21 .
[0037] The preferred embodiment of this invention is designed as an easily installed aftermarket accessory which is stored in a protective housing when not deployed.
[0038] Therefore, FIG. 3 shows a view at the rear vehicle 1 in the deployed position with telescoping rods 27 supporting mirror 11 in proper orientation visible through rear window 8 .
[0039] FIG. 4 shows an outline of housing 26 with self opening and closing lips 35 through which mirror 11 is driven by telescoping rod assembly 27 . The telescoping rod 27 is of non-circular crossection so as to resist twisting and have the ability to maintain rotational registration. It is driven in similar fashion to automotive power antennas via an internal semi-rigid cable which is urged into and out of housing 31 by a actuator or motor, such as a reversible DC permanent magnet gearmotor 32 . While it may be installed at any rearward location, such as in the fender or rear trunk cover, in a preferred embodiment, housing 26 is attached to a bracket that fits under license plate 25 and shares the same mounting screws. Housing 31 is angle adjustable at bracket 33 and mirror mount 34 is a ball joint that places mirror 11 in a vertical position at the correct view line before clamping. Position sensors are adjustable to customize the deployed and stored positions for a particular installation. These can be actual mechanical limit switches or optical or magnetic sensors. Inner housing 30 contains batteries and radio receiver and control equipment.
[0040] The block diagram of FIG. 5 illustrates the operation of the embodiment of FIG. 4 . A small transmitter 40 similar to a garage door opener is used by the driver to toggle between deploy and store modes by pressing push button 41 . Receiver 42 through control block 43 operates gearmotor 32 with the proper polarity to accomplish the desired move. Deployed limit sensor 46 stops motor 32 when at the proper level. Stored limit sensor 45 stops motor 32 when mirror 11 is properly stored. Batteries 44 can be 3 or 4 alkaline batteries such as “C” size. Such use would simplify installation, but it adds the need to change depleted batteries. This can be eliminated at the expense of a slightly more involved installation by using rechargeable batteries such as NiCad or LiMH types which are charged by charger 48 intermittently every time brake light 47 is actuated. Another simplification substitutes a single optical fiber connecting an internal controller consisting of a pushbutton, battery, and LED to controller 43 directly. While eliminating the radio frequency link, it makes the installation more cumbersome by requiring routing a tiny optical fiber from the outside of the vehicle to the interior.
[0041] FIG. 6 shows an embodiment similar to the preferred embodiment but using a single reflecting surface mirror 57 . Housing 55 is attached to horizontal adjuster link 53 with clamp 54 . While the assembly can be attached anywhere to a rear fender or to a trunk cover, preferably the assembly attaches to the license plate holder via plate 52 . Telescoping assembly 56 must be set in a vertical position for this embodiment. Internally, an actuator or motor, such as a second gearmotor, is used to rotate the entire vertical positioning assembly to orient mirror 57 first in one position along the traffic lane and then in the second position in the opposite direction. Transmitter controller 50 has now been enhanced with two position rotary control 51 to control rotation, in addition to push button 41 to control up and down operations.
[0042] FIGS. 7 and 8 illustrate an embodiment of this invention on vehicle 62 wherein mirror 11 is in a fixed deployed position. It is simply clamped to a rigid vehicle cartop carrier 63 via clamp 65 . It is then adjusted by sliding out bent member 66 out of fixed member 64 to the desired position and clamping via thumbscrew 67 .
[0043] FIGS. 9 and 10 illustrate an embodiment of this invention as original equipment.
[0044] FIG. 9 shows vehicle 72 with rear window 74 and roof mounted streamlined pod 73 housing a stored mirror assembly.
[0045] FIG. 10 , the side view, shows the mirror 11 deployed at the end of telescoping rod 75 and short arm 76 after emerging from pod 73 through door 77 . In actuality, streamlined pod 73 can be eliminated with the entire accessory stored within the normal exterior roofline with the option of a slight bulge on the interior roofline. When deployed, door 77 is powered open (arc “A”) and telescoping members 75 are urged forward (distance “B”) wherein at the limit of movement, arm 76 swings down (“C”) thereby placing mirror at the ideal position for viewing through rear window 74 . The reverse operations are used to store the feature in its roofline storage compartment. Mirror 11 has the collapsible feature to fit more easily in a flat compartment.
[0046] FIGS. 11-13 describe an aftermarket deployable mirror embodiment which is very simple to install with no tools. This system is simply straddled over the glass edge of a side rear window, adjusted for horizontal orientation, and sealed with flexible gaskets.
[0047] FIG. 11 shows a side view of vehicle 80 with mirror system in housing 81 which is attached to rear side window 85 . When deployed, see dashed lines, telescoping rod 83 is driven out by an outwardly extendable member, such as a telescoping member or a perforated semi-rigid plastic tape, wherein a short horizontal arm 84 (as in FIG. 12 ) pivoted at 82 deploys to place mirror 11 within view through rear vehicle window. Since housing 81 is flat to conform to the side of vehicle 80 , mirror 11 preferably has the collapsible feature.
[0048] While other power sources, such as batteries, may be used, the schematic diagram of FIG. 13 shows how power is preferably derived by plugging plug 98 into the vehicle accessory (cigarette lighter) socket. A front mounted control pod 97 may be a switch mechanism, such as simply two momentary single pole normally open switches, one to initiate “deploy” 90 and a second to initiate “store” 91 . Using no electronics or microprocessors, two automotive type relays mounted at the rear side window unit are all that is necessary for control. Each of the relays 92 and 93 preferably has three contacts; two are motor drive contacts and are normally open types, while the third set of contacts are normally closed and are used as safety contacts to prevent a short circuit situation if a “store” button 91 is accidentally hit while the deploy process in operation (or vice versa). This circuit latches the relays at the start of the deploy or start process so that a short press of a button is all that is needed to start a process which will stop itself when the appropriate normally closed limit switch is operated. Limit switch 95 stops the deploy process, while limit switch 96 stops the store process. A motor is used, such as gear motor 94 , which is preferably a permanent magnet reversible DC motor.
[0049] FIGS. 14 through 16 describe an alternate closed circuit video display embodiment using two video cameras and a flat panel display configured as a split screen with the image form each camera providing image for half the screen. Versions of this embodiment for use as an aftermarket installation would use fixed cameras attached to the rear bumper and aimed about 180 degrees away from each other (to the sides of the vehicle) to capture a view of the traffic lane in either direction.
[0050] FIGS. 14 and 15 relate to dual camera assembly 100 intended for use as original equipment. Arm 104 is pivoted from a powered pivot 105 and terminates in camera head 101 with video cameras 102 and 103 aimed away from each other.
[0051] FIG. 15 shows a portion of vehicle 107 with a hatch lid 106 incorporated in its trunk lid. Camera assembly 100 is pivoted inside of the trunk lid so that it can be deployed out by swinging on power pivot 105 upon command. Hatch lid 106 is powered open prior to deployment. It can be appreciated that cameras 102 and 103 would have a good view of the traffic lane in both directions in the deployed position.
[0052] Simultaneously with the deployment of the cameras, flat display 109 flips down from its storage position 110 (as in FIG. 16 ) flush with the ceiling of the vehicle interior. Note that display 109 in the deployed position is within the viewscape of rear window 108 ; its image is also viewable as reflected in the rear view mirror.
[0053] In the foregoing description, certain terms and visual depictions are used to illustrate the preferred embodiment. However, no unnecessary limitations are to be construed by the terms used or illustrations depicted, beyond what is shown in the prior art, since the terms and illustrations are exemplary only, and are not meant to limit the scope of the present invention.
[0054] It is further known that other modifications may be made to the present invention, without departing the scope of the invention, as noted in the appended Claims. | A visual aid helping a driver to safely back into a traffic lane from a parking place, said visual aid providing visual images from a vantage point just beyond the rear periphery of a motor vehicle, wherein the visual information shows vehicular and/or pedestrian traffic in close proximity to rear of the motor vehicle and obliquely to left and right sides thereof, said visual images being presented within the view of the driver. | 1 |
FIELD OF THE INVENTION
[0001] The invention relates to the technical field of monitoring transaction, particularly to a method and system for monitoring transaction execution on the Internet and computer storage medium.
BACKGROUND
[0002] Various transactions, for example, a third party application on an open platform, a virtual network community, a video broadcasting website, etc, are executed in networks. Generally, the service is provided to the user dependent on its execution environments, the execution environments including various elements for providing logic processing and data storage for the transaction. During the execution process of the transaction, it is necessary to pay attention to failures appearing in the execution environments of the transaction and timely analyze and process the failures.
[0003] A traditional method for monitoring transaction monitors each kind of execution environments in real time, the execution environments including network environments, devices such as a server and so on, transaction components, and transaction software etc. If an abnormality is monitored in an execution environment, alarms will be issued in the form of short messages or e-mails, and a person maintaining the transaction can learn of the execution environment in which a failure occurs by viewing contents of the alarms.
[0004] However, various kinds of execution environments are interdependent, so as to provide normal and stable operated service. For example, the normal execution of the transaction software depends on the normal execution of the transaction components, and the normal execution of the transaction software and the transaction components depends on the normal execution of execution environments such as the network environments and the server, etc. Therefore, when a failure is monitored in an execution environment of the transaction during the execution process of the transaction, it is usual to issue a large number of alarms to the person maintaining the transaction, which causes the person maintaining the transaction unable to accurately locate the failure.
SUMMARY OF THE INVENTION
[0005] Based on the foregoing contents, it is necessary to provide a method for monitoring transaction execution on Internet which may locate the failures precisely, with regard to the problem of the eruptive large number of alarms.
[0006] Besides, it is necessary to provide a system for monitoring transaction execution on Internet which may locate the failures precisely.
[0007] Furthermore, it is necessary to provide a computer storage medium for monitoring transaction execution on Internet which may locate the failures precisely.
[0008] A method for monitoring transaction execution on the Internet, comprising the steps of:
[0009] acquiring monitoring data of a transaction executing on the Internet, and abstracting abnormal data from the monitoring data;
[0010] acquiring an abnormal service based on the abnormal data; and
[0011] locating a source of execution failure in architecture layers based on the abnormal service.
[0012] A system for monitoring transaction execution on the Internet, comprising:
[0013] a data monitoring module configured for acquiring monitoring data of a transaction executing on the Internet, and abstracting abnormal data from the monitoring data;
[0014] an abnormal service acquiring module configured for acquiring an abnormal service based on the abnormal data; and
[0015] a detecting module configured for locating a source of execution failure in architecture layers based on the abnormal service.
[0016] A computer storage medium for storing computer executable instructions which are used for controlling the method for monitoring transaction execution on the Internet, the method comprising:
[0017] acquiring monitoring data of a transaction executing on the Internet, and abstracting abnormal data from the monitoring data;
[0018] acquiring an abnormal service based on the abnormal data; and
[0019] locating a source of execution failure in architecture layers based on the abnormal service.
[0020] With the method and system for monitoring transaction execution on the Internet and the computer storage medium described above, upon a abnormal service occurs, the source of execution failure is founded by detecting the architecture layers related to the service in accordance with the architecture layers, then it can be determined that whether a failure in each architecture layer is the primary factor that cause the abnormal service, accordingly, the accurately locating of the execution failure can be achieved, which avoids the one by one analysis for the numerous alarms by the person maintaining the transaction.
DESCRIPTION OF THE DRAWINGS
[0021] FIG. 1 is a flow diagram of a method for monitoring transaction execution on the Internet in accordance with an embodiment of the disclosure;
[0022] FIG. 2 is a diagram of an architecture hierarchy in accordance with an embodiment of the disclosure;
[0023] FIG. 3 is a flow diagram of the processing of locating the source of execution failure in the architecture layers based on the abnormal service in accordance with an embodiment of the disclosure;
[0024] FIG. 4 is a flow diagram of the processing of processing the recorded abnormal points in the sequence processing history in the architecture hierarchy to locate the source of execution failure in accordance with an embodiment of the disclosure;
[0025] FIG. 5 is a structure diagram of a system for monitoring transaction execution on the Internet in accordance with an embodiment of the disclosure;
[0026] FIG. 6 is a structure diagram of the detecting module in accordance with an embodiment of the disclosure;
[0027] FIG. 7 is a structure diagram of the detecting module in accordance with another embodiment of the disclosure.
DETAILED DESCRIPTION
[0028] As shown in FIG. 1 , in an embodiment, the method for monitoring transaction execution on the Internet comprises the following steps:
[0029] Step S 10 : acquiring monitoring data of a transaction executing on the Internet and abstracting abnormal data from the monitoring data.
[0030] In the embodiment, the monitoring data of the transaction is acquired by monitoring the execution process of the transaction, wherein the monitoring data is configured for explicitly indicating whether the transaction is healthy. For example, the monitoring data can be the number of online users, the number of complaints by users, the delay induced when a user accesses a web page, and so on. The monitoring data comprises data produced by the normal execution state and abnormal data produced by the abnormal execution. For example, the abnormal data can be data indicating that a web page is inapplicable.
[0031] Step S 30 : acquiring an abnormal service based on the abnormal data.
[0032] In the embodiment, in the execution process of the transaction, multiple functions are provided for a user via various services. For example, in a transaction, various small functions provided by multiple services form a processing capability owned by an application. The abnormal service in which a failure occurs is acquired based on the abstracted abnormal data, and the source inducing the failures in the service is found by subsequent processing.
[0033] S 50 : locating the source of execution failure in architecture layers based on the abnormal service.
[0034] In the embodiment, the architecture hierarchy of the transaction execution comprises an access layer, a logic layer, and a data layer, wherein the logic layer provides the user with the page for displaying the interface and makes response to variety requests of the user, and then proceeds logic processing, and the data layer is responsible for data storage, the transaction executed in the architecture hierarchy responds to the variety requests of the user. In particular, the architecture hierarchy is a layered model that comprises the access layer, the logic layer and the data layer in sequence from the front end to the back end. Wherein, the access layer is configured for receiving requests from a user and forwarding the requests from the user to the logic layer; the logic layer is configured for processing user request inputted from the access layer, performing logic processing for the transaction by using data stored in the data layer, and returning the processing result to the access layer; and the data layer is configured for temporarily or persistently storing data.
[0035] As shown in FIG. 2 , each of the access layer, the logic layer, and the data layer comprises elements such as transaction software, transaction components, basic networks, basic devices and infrastructures etc. Wherein, the transaction components are public domain software packets or software architecture packets (for example, WebServer components, network communicating components, database components, etc.); the transaction software executes on the transaction components, and most of the transaction software are programs directly provided for the user's access (for example, Common Gateway Interface (CGI) providing a page displaying an interface for a user); the basic devices are devices such as servers, switches, routers, etc.; and the infrastructures are data center, electrical supply equipments, data center space, etc.
[0036] Furthermore, the architecture hierarchy of the transaction can also perform configuration of architecture hierarchy as transaction software layer, a transaction component layer, a basic device layer, and an infrastructure layer, and will not be divided into the access layer, the logic layer, and the data layer.
[0037] In the architecture hierarchy of the transaction, in addition to detecting the architecture layer in which the abnormal service exists, multiple architecture layers related with the abnormal service should also be detected for abnormality in order to locate the source of execution failure, and obtain the failure source inducing an abnormality in the service.
[0038] In the above method for monitoring transaction execution, the processing of acquiring a corresponding abnormal service based on the abnormal data in the monitoring data and locating the source of execution failure in related architecture layers based on the abnormal service is not simply locating the abnormal service as the source of execution failure in the execution of the transaction on the Internet, but to correspondingly detect the architecture layers related with the abnormal service to locate the source of execution failure, which improves the monitoring accuracy, and further facilitates the maintenance of the transaction executing on the Internet.
[0039] As shown in FIG. 3 , in an embodiment, the specific processing of the above step S 50 comprises:
[0040] Step S 510 : detecting whether an abnormality exists in the architecture layer in which the abnormal service exists; if so, proceeding to step S 520 ; or else, the process ends.
[0041] In the embodiment, it is to detect whether respective segments in the architecture layer in which the abnormal service exists are abnormal, and record the abnormal points appearing in the architecture layer. Different architecture layers and different elements in an architecture layer correspond to different abnormal points. Specifically, an abnormal point is a description of an abnormal phenomenon, which is configured for determining whether an architecture layer and elements in thereof are abnormal. For example, for a basic device in an architecture layer, the abnormal point is that a server cannot be connected; and for a basic network, the abnormal point is that the packet loss rate of the network is larger than 30%.
[0042] Step S 520 , recording the abnormal point in the architecture layer in which the abnormal service exists.
[0043] Step S 530 , starting from a next architecture layer related with the abnormal service, performing the detection layer by layer in a sequence from the front end to the back end, and determining whether there exists any abnormality in the detected architecture layer; if so, then proceeding to step S 40 , or else, the process ends.
[0044] In the embodiment, a service in an architecture layer is usually dependent on a service(s) in a next architecture layer under the former layer so as to implement a corresponding function, these services are called downstream services. Therefore, it is necessary to detect layer by layer which starts from the next architecture layer to obtain the abnormal points existed in each architecture layer. Specifically, detecting each architecture layer in a sequence from the front end to the back end, and determining whether the detected architecture layer has a downstream service. If so, then it is further determined whether there is an abnormal point in the downstream service. It there is an abnormal point in the downstream service, the abnormal point is recorded. Wherein, in the architecture hierarchy of the executed transaction, the sequence from the front end to the back end refers to the sequence of the layers ordered as access layer, logic layer, and data layer, or to the sequence of transaction software, transaction component, basic device and infrastructure.
[0045] In another embodiment, the above step S 50 further comprises:
[0046] determining on the architedure layer where the abnormal service locates whether there is a next architecture layer related with the abnormal service; if so, then proceeding to step S 530 ; or else, locating the abnormal point recorded as the source of execution failure.
[0047] In the embodiment, when it is determined that an abnormal service normally operates independent of services in a next architecture layer, an abnormal point in the architecture layer in which the abnormal service exists is the source of execution failure, and it is unnecessary to detect layer by layer, so the efficiency of failure detecting is improved. Specifically, determining whether there is a service related with the abnormal service (i.e. a downstream service), the determined downstream service is highly associated with the abnormal service that performs the determination, and the abnormal service that performs the determination is operated under the dependency of the downstream service.
[0048] Step S 540 , recording the abnormal point in the detected architecture layer.
[0049] Step S 550 , processing the recorded abnormal points in sequence of the architecture layers in the architecture hierarchy to locate the source of execution failure.
[0050] In the embodiment, multiple recorded abnormal points are collected, and are processed in sequence from the front end to the back end in the architecture hierarchy to locate the source of execution failure. In the execution process of the transaction, an abnormal point appearing in any architecture layer may lead to the abnormal service. So collecting all abnormal points can determine the most possible failure cause and implement correlation analysis of respective architecture layers. Specifically, several recorded abnormal points are analyzed in association in the sequence of the architecture layers in the architecture hierarchy obtain the source of execution failure.
[0051] In the above method for monitoring transaction execution on the Internet, the most possible failure cause is determined by collecting all abnormal points to implement correlation analysis of respective architecture layers. That is, relatively discrete abnormal points are considered, so an accurate failure cause is obtained.
[0052] In an embodiment, the specific processing of the above step S 550 comprises: abstracting an abnormal point corresponding to a maximum priority as the source of execution failure from the recorded abnormal points based on priorities corresponding to the architecture layers.
[0053] In the embodiment, a priority can be preset for each architecture layer, the priority being configured for identifying the possibility of an abnormal point inducing an abnormal service in an architecture layer. That is to say, the priority also represents an influence factor inducing an abnormal service. An abnormal point having a maximum priority is an abnormal point having a maximum influence factor inducing an abnormal service, the possibility of becoming the source of execution failure of which is the maximum. Therefore, the abnormal point having the maximum priority can be abstracted from the recorded abnormal points based on priorities corresponding to the architecture layers, and the source of execution failure can be located based on the abstracted abnormal point.
[0054] As to multiple abnormal points having the maximum priority, it is further determined which one of the multiple abnormal points is the source of execution failure based on priorities of elements in an architecture layer. For example, if a failure occurs in an infrastructure, the failure must influence the basic devices, the basic components and the basic software. Therefore, if there is an abnormal point in both an infrastructure and a basic device, the abnormal point in the infrastructure is preferably considered as the source of execution failure, etc.
[0055] As shown in FIG. 4 , in another embodiment, the specific processing of the above step S 550 comprises:
[0056] Step S 551 , abstracting an abnormal point corresponding to an architecture layer at a rearmost end from the recorded abnormal points.
[0057] In the embodiment, the abnormal point corresponding to the architecture layer at the rearmost end is abstracted from the recorded abnormal points based on the sequence of the architecture layers from the front end to the back end, and the abnormal point generated in the architecture layer at the rearmost end is taken as the source inducing the abnormal service.
[0058] Step S 553 , locating the abstracted abnormal point as the source of execution failure.
[0059] In an embodiment, the above method for monitoring transaction execution on the Internet further comprises presenting the source of execution failure and abnormal point in a failure locating page to facilitate viewing by the person maintaining the transaction.
[0060] As shown in FIG. 5 , in an embodiment, the system for monitoring transaction execution on the Internet comprises a data monitoring module 10 , an abnormal service acquiring module 30 , and a detecting module 50 . Wherein:
[0061] The data monitoring module 10 is configured for acquiring monitoring data of a Internet transaction and abstracting abnormal data from the monitoring data.
[0062] In the embodiment, the monitoring data of the transaction is acquired by monitoring the execution process of the transaction, wherein the monitoring data is configured for explicitly indicating whether the execution of the transaction is healthy. For example, the monitoring data can be the number of online users, the number of complaints by users, the delay induced when a user accesses a web page, and so on. The monitoring data comprises data produced by the normal execution state and abnormal data produced by the abnormal execution. For example, the abnormal data can be data indicating that a web page is inapplicable.
[0063] The abnormal service acquiring module 30 is configured for acquiring an abnormal service based on the abnormal data.
[0064] In the embodiment, in the execution process of the transaction, multiple functions are provided for a user via various services. For example, in a transaction, various small functions provided by multiple services form a processing capability owned by the application. The abnormal service acquiring module 30 acquires the abnormal service where failure occurs based on the abstracted abnormal data, and the source inducing the abnormal service is found out by subsequent processing.
[0065] The detecting module 50 is configured for locating the source of execution failure in architecture layers based on the abnormal service.
[0066] In the embodiment, the architecture hierarchy of the transaction execution comprises an access layer, a logic layer, and a data layer, wherein the logic layer provides the user with the page for displaying the interface and makes response to variety requests of the user, and then proceeds logic processing, and the data layer is responsible for data storage, the transaction executed in the architecture hierarchy responds to the variety requests of the user. In particular, the architecture hierarchy is a layered model that comprises the access layer, the logic layer and the data layer in sequence from the front end to the back end. Wherein, the access layer is configured for receiving requests from a user and forwarding the requests from the user to the logic layer; the logic layer is configured for processing user request inputted from the access layer, performing logic processing for the transaction by using data stored in the data layer, and returning the processing result to the access layer; and the data layer is configured for temporarily or persistently storing data.
[0067] Each of the access layer, the logic layer, and the data layer comprises elements such as transaction software, transaction components, basic networks, basic devices and Infrastructures etc. Wherein, the transaction components are public domain software packets or software architecture packets; the transaction software executes on the transaction components, and most of the transaction software are programs directly provided for the user for accessing; the basic devices are devices such as servers, switches, routers and so on; and the infrastructures are data center, electrical supply equipments, data center space and so on.
[0068] Furthermore, the architecture system of the transaction can also directly set the architecture hierarchy as a transaction software layer, a transaction component layer, a basic device layer and an infrastructure layer, and is not divided into the access layer, the logic layer and the data layer any longer.
[0069] In the architecture system of the transaction, in addition to detecting whether an abnormality exists in the architecture layer in which the abnormal service exists, the detecting module 50 further detects multiple architecture layers related with the abnormal service for abnormality in order to locate the source of execution failure, and obtain the failure source inducing an abnormality in the service.
[0070] In the above system for monitoring transaction execution on the Internet, the processing of acquiring a corresponding abnormal service based on the abnormal data in the monitoring data and locating the source of execution failure in related architecture layers based on the abnormal service is not simply to take the abnormal service as the source of execution failure in the execution of the transaction on the Internet, but to correspondingly detect the architecture layers related with the abnormal service to locate the source of execution failure, which improves the monitoring accuracy, and further facilitates the maintenance of the transaction executing on the Internet is further facilitated.
[0071] As shown in FIG. 6 , the above detecting module 50 comprises an initial detecting unit 510 , a layer by layer detecting unit 530 , and a processing unit 550 .
[0072] The initial detecting unit 510 is configured for detecting whether an abnormality exists in the architecture layer, in which the abnormal service exists; if so, then recording the abnormal point in the architecture layer in which the abnormal point exists; or else, stopping execution.
[0073] In the embodiment, the initial detecting unit 510 detects whether respective segments in the architecture layer in which the abnormal service exists are abnormal, and records abnormal points appearing in the architecture layer. Different architecture layers and different elements in an architecture layer correspond to different abnormal points. Specifically, an abnormal point is a description of an abnormal phenomenon, which is configured for determining whether an architecture layer and elements in the architecture layer are abnormal.
[0074] The layer by layer detecting unit 530 is configured for starting from a next architecture layer related with the abnormal service and determining whether there is an abnormality in the detected architecture layer in sequence from the front end to the back end layer by layer; if so, then recording the abnormal point in the detected architecture layer.
[0075] In the embodiment, a service in an architecture layer is usually dependent on a service(s) in a next architecture layer relatively below the former layer to implement a corresponding function, these service(s) are referred to as downstream service. Thus, it is necessary for the layer by layer detecting unit 530 to detect layer by layer whether there is an abnormal point in the detected architecture layer starting from the next architecture layer of the architecture layer in which the abnormal service exists. Specifically, the layer by layer detecting unit 530 detects each architecture layer in sequence from the front end to the back end, and determines whether there is a downstream service in the detected architecture layer. If so, then it is further determined whether there is an abnormal point in the downstream service. It there is an abnormal point in the downstream service, the abnormal point is recorded. Wherein, in the architecture hierarchy of the executed transaction, the sequence from the front end to the back end refers to the sequence of the layers ordered as access layer, logic layer, and data layer, or to the sequence of transaction software, transaction component, basic device and infrastructure.
[0076] The processing unit 550 is configured for processing the recorded abnormal points to locate the source of execution failure in accordance with the sequence of the architecture layers in the architecture hierarchy.
[0077] In the embodiment, the processing unit 550 collects multiple recorded abnormal points, and processes them in sequence from the front end to the back end in the architecture hierarchy to locate the source of execution failure. In the execution process of the transaction, an abnormal point appearing in any architecture layer may lead to the abnormal service. So collecting all abnormal points can determine the most possible failure cause and implement correlation analysis of respective architecture layers. Specifically, the processing unit 550 analyzes several recorded abnormal points in association in the sequence of the architecture layers in the architecture hierarchy to obtain the source of execution failure.
[0078] In the above system for monitoring transaction execution on the Internet, the most possible failure cause is determined by collecting all abnormal points together to implement correlation analysis of respective architecture layers. That is, relatively discrete abnormal points are considered, so an accurate failure cause is obtained.
[0079] As shown in FIG. 7 , the above detecting module 50 further comprises a layer determining unit 540 for determining whether there is a next architecture layer relative to the architecture layer where the abnormal service occurs related with the abnormal service, and if so, informing the layer by layer detecting unit 530 , or else informing the processing unit 550 .
[0080] In the embodiment, when the layer determining unit 540 determines that an abnormal service normally operates independent of a service(s) in a next architecture layer, an abnormal point in the architecture layer in which the abnormal service exists is the source of execution failure, and it is unnecessary to detect layer by layer, so the efficiency of failure detecting is improved. Specifically, the layer determining unit 540 determines whether there is a service related with the abnormal service (i.e. a downstream service) in the next architecture layer, and determines whether the downstream service is highly associated with the abnormal service to be located, and the abnormal service to be located is operated on the dependency of the downstream service.
[0081] The above processing unit 550 is further configured for locating the recorded abnormal point as the source of execution failure.
[0082] In an embodiment, the above processing unit 550 is further configured for abstracting an abnormal point corresponding to a maximum priority as the source of execution failure from the recorded abnormal points in accordance with priorities corresponding to the architecture layers.
[0083] In the embodiment, a priority can be preset for each architecture layer, the priority being configured for identifying the possibility of an abnormal point inducing an abnormal service in an architecture layer. That is to say, the priority also represents an influence factor inducing an abnormal service. An abnormal point having a maximum priority is an abnormal point having a maximum influence factor causing a service abnormal, the possibility of becoming the source of execution failure of which is the maximum. Therefore, the processing unit 550 can abstract the abnormal point having the maximum priority from the recorded abnormal points based on priorities corresponding to the architecture layers, and thus locate the failure source based on the abstracted abnormal point.
[0084] As to multiple abnormal points having the maximum priority, the processing unit 550 further determines which one of the multiple abnormal points is the source of execution failure based on priorities of elements in an architecture layer. For example, if a failure occurs in an infrastructure, the failure must influence the basic devices, the basic components and the basic software. Therefore, if there is an abnormal point in both an infrastructure and a basic device, the abnormal point in the infrastructure is preferably considered as the source of execution failure, and so on.
[0085] In another embodiment, the above processing unit 550 is further configured for abstracting an abnormal point corresponding to the architecture layer at the rearmost end from the recorded abnormal points, and locating the abstracted abnormal point as the source of execution failure.
[0086] In the embodiment, the processing unit 550 abstracts the abnormal point corresponding to the architecture layer at the rearmost end from the recorded abnormal points in sequence from the front end to the back end in the architecture hierarchy, and takes the abnormal point in the architecture layer at the rearmost back end as the source causing the service abnormal.
[0087] In an embodiment, the above system for monitoring transaction execution on the Internet further comprises presenting the source of execution failure and its corresponding abnormal point in a failure locating page to facilitate viewing by the person maintaining the transaction.
[0088] In the above described method and system for monitoring transaction execution on the Internet and the computer storage device thereof, architecture layers associated with the abnormal service are detected in accordance with the architecture hierarchy to obtain the source of the execution failure, so as to learn whether a failure occurring in each architecture layer is a primary factor for causing the abnormal service. So the execution failure can be accurately located in the multiple architecture layers, and it is unnecessary for the person maintaining the transaction to analyze the contents of a large number of alarms one by one.
[0089] The invention further provides a computer storage medium storing computer executable instructions, wherein the computer executable instructions are operable for controlling a computer to implement the above method for monitoring transaction execution on the Internet, specific steps of which are described above and thus are omitted herein.
[0090] The above embodiments are merely several implementations of the invention, the descriptions of which are specific and in detail and cannot be considered as limiting the scope of the invention. It should be pointed out that the person skilled in the art can make some alterations and improvements to the invention without departing from the concept of the invention. The protection scopes of the invention are merely limited by the claims. | A presentation control method for an interaction interface comprises the following steps: acquiring a contact list and a message of a friend in the contact list; generating an image block corresponding to the friend in the contact list; and presenting the message of the friend in the image block. The aforementioned presentation control method for an interaction interface as well as a real-time communications tool and a computer storage medium generate a corresponding image block for every friend in the contact list, so as to further present the message of the friend in the image block. A user can directly view a message of a friend through an image block in an interface, so that the operation is simplified and the convenience of operations is enhanced. | 7 |
RELATED APPLICATION
[0001] This application relates to, but does not claim priority from, EPO 12 177 709.8 filed Jul. 24, 2012, the entire contents of which are incorporated herein by reference.
FIGURE SELECTED FOR PUBLICATION
[0002]
FIG. 7
BACKGROUND OF THE INVENTION
[0003] 1. Field of the Invention
[0004] The present invention relates to a device for micronization and a method for operating such device.
[0005] 2. Description of the Related Art
[0006] New physical properties, bioavailability and bio-efficacy of solid substances are often intrinsically related to the primary particle size and proportion of amorphous surface area. Particle size reduction by top-down processing i.e. milling is one of various strategies for improving solubility and reactive characteristics of poorly water-soluble ingredients. Thus, many attempts have been conducted to obtain good bioavailability achieved by creating an amorphous product.
[0007] Micronization is a highly effective kind of milling which allows a direct production of very fine particles, typically 5-50 μm, from relatively coarse-grained starting material, particle size, e.g. 0.1-1 mm.
[0008] Technological operation of micronization is widely used in production of active substances and excipients for pharmaceutical, cosmetic, and agrochemical industries, in chemical industry (e.g. fillers, pigments), and in many other fields.
[0009] Micronization can be accomplished by a prolonged milling in various classical mills (ball mill, jet mill, disintegrators etc.), wherein the milling process is based mainly on collisions of particles between themselves or with hitting elements of a milling device.
[0010] Disintegrators of various types are known from the prior art Examples of such disintegrators are for example disclosed in U.S. Pat. No. 4,406,409 A1 and HR 990 263 A2, the contents of each of which are incorporated herein by reference. Those disintegrators are principally based on the concept of two high-speed opposite rotating discs. The discs bear particular hitting elements, blades, which partially collide with particles directly, but mostly targeted to create an efficient airflow by mimicking turbines, driving particles into mutual collisions. In literature, there are described devices with various shaped blades on the discs:
1. round-shaped blades; 2. blades in the shape of elongated plates; and 3. blades in the shape of slightly curved plates;
without or with additional particular mechanic details (e.g. indented hitting surface) which eventually improve a course of micronization process due affecting airflow.
ASPECTS AND SUMMARY OF THE INVENTION
[0014] In response, the present invention provides an improved device for micronization based on the concept of desintegrator with two opposite rotating discs, known also as disintegration. The present device modified for significant improvement in micronization process. The main improvement of the present invention is a modification of particle hitting elements or blades, in positioning and shape. Along each of disc in two or several layers results in significant improvement of micronization. Discs are situated within the micronizer in a way that the layers of blades of first and second disc enter into each other's.
[0015] Particles of the material being micronized, carried by centrifugal force from the center of the device, pass through several layers of cubical and triangular shaped blades in the way to collide repeatedly with other particles and between rows of blades. Additionally, triangular blades, oppose to centrifugal particle flow by forcing them into repeated collisions, resulting in improved reduction of their size.
[0016] The present invention also provides a modified device for an improved milling process method, which is based on the concept of a disintegrator.
[0017] A device for micronization of substances according to the present invention comprises two rotors driven in a direction opposite to each other, each rotor carrying at least one row of multiple hitting elements forming a ring, said rings being arranged concentrically the rings of the different rotors engaging alternately with one another, the hitting elements being suitably arranged to provide transportation of the substance from inside the rings to the outside by effecting a suitable airflow, at least two directly adjoining rings carrying hitting elements with different foot print wherein at least a first ring is equipped with trapezoidal hitting elements with trapezoidal foot print and at least one other ring directly adjoining the first ring is equipped with triangular hitting elements with triangular foot print.
[0018] Present research showed that the footprint of the hitting elements has significant influence on the results of micronization. If was found out that with reduced particle size the effect of inter particle collisions has less influence on the micronization result and thus conventional turbine-like footprints of the hitting elements get less effective. The hitting elements according to the present invention provide a suitable air flow to effect inter particle collisions but also provide improved collisions between the particles and the hitting elements as well as permanent milling between the hitting elements of directly adjoining rings.
[0019] In another embodiment of the device one side of the triangular hitting elements and/or one of the parallel sides of the trapezoidal hitting elements is perpendicularly oriented to a radius crossing the hitting element.
[0020] Due to the arrangement of the hitting elements perpendicular to a radius crossing the respective hitting elements are suitably arranged to provide parallel arranged surfaces for milling of the substance between adjoining rings.
[0021] In a further embodiment of the device the trapezoidal hitting elements are of rectangular foot print.
[0022] With a rectangular footprint the trapezoidal hitting elements may be of generally cubical shape. Compared to other shapes cubical hitting elements are easier to produce and thus cheaper in production.
[0023] It was unexpectedly found that the shape of the hitting elements of one rotating disc in a form of cubes and other in a form of tightly positioned triangular shapes ( FIG. 5 ), unexpectedly results in significantly improved efficacy of micronization.
[0024] In another embodiment of the present device the triangular hitting elements are of basically right angled triangular foot print.
[0025] The right angled triangular footprint allows manufacturing of the triangular hitting elements with rectangular base elements that are divided diagonally. It is thus possible to use base elements with rectangular footprint to manufacture both, the rectangular hitting elements and the triangular hitting elements.
[0026] In a preferred embodiment the perpendicularly oriented side of the triangular hitting elements is the longer cathetus. Preferably the longest cathetus is oriented to the outward circumference of it's respective ring.
[0027] The longer cathetus of the triangular hitting elements is thus tangentially oriented and may serve for milling. The milling will take place between the tangentially oriented surface of the triangular hitting elements and surfaces of hitting elements of a cicumferring and directly adjoining ring. Furthermore the triangular hitting elements thus provide for sufficient air flow from the center of the rings to the outside.
[0028] In another embodiment the longest side of the triangular hitting elements is oriented in front in direction of rotation of the respective rotor.
[0029] Particularly in combination with right angled triangular hitting elements with the longest cathetus oriented to the outward circumference of the respective ring this embodiment directs the particles in backward loops, i.e. backward in substantially radial direction, thus resulting in extended time within the device and thus more inter particle collisions.
[0030] In another embodiment the hitting elements of directly adjoining rings are suitably arranged to provide milling between the hitting elements of adjacent rings.
[0031] As with shrinking particle size inter particle collisions get less important for size reduction of the particles, permanent milling between the hitting elements of adjacent rings becomes more relevant for the disintegration. By arranging the hitting elements of directly adjoining rings in this manner disintegration results are further enhanced.
[0032] Each ring may carry a number of hitting elements equivalent to the diameter in cm of the respective ring.
[0033] The number of hitting elements per ring obtained by this rule provides an optimal ratio of hitting elements to spaces between the hitting elements and thus further enhances the efficacy of disintegration.
[0034] The hitting elements may be made of stainless steel or ceramics and/or coated with industrial diamond or ruby.
[0035] The above materials and/or coatings provide high durability of the hitting elements as well as high availability of the used materials.
[0036] To achieve the above-mentioned advantage in manufacture of the hitting elements out of identical base elements, the triangular hitting elements and the trapezoidal hitting elements may have at least two sides with coinciding length.
[0037] Thus not only rectangular but also trapezoidal elements can serve as base elements for both, trapezoidal and triangular hitting elements.QQ
[0038] The above and other aspects, features and advantages of the present invention will become apparent from the following description read in conjunction with the accompanying drawings, in which like reference numerals designate the same elements.
BRIEF DESCRIPTION OF THE DRAWINGS
[0039] FIG. 1 shows a perspective view of a disintegrator.
[0040] FIG. 2 shows a sectional view of the disintegrator FIG. 1 .
[0041] FIG. 3 shows a first embodiment of hitting elements according to the state of the art.
[0042] FIG. 4 shows a second embodiment of hitting elements according to the state of the art.
[0043] FIGS. 5 and 6 show enlarged sections of FIG. 3 and FIG. 4 .
[0044] FIG. 7 shows a sectional view of the rotors according to an embodiment of the present invention.
[0045] FIG. 8 shows an enlarged section of FIG. 7 .
[0046] FIGS. 9-11 show the hitting elements according to FIGS. 7 and 8 in enlarged view.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0047] Reference will now be made in detail to embodiments of the invention. Wherever possible, same or similar reference numerals are used in the drawings and the description to refer to the same or like parts or steps. The drawings are in simplified form and are not to precise scale. The word ‘couple’ and similar terms do not necessarily denote direct and immediate connections, but also include connections through intermediate elements or devices. For purposes of convenience and clarity only, directional (up/down, etc.) or motional (forward/back, etc.) terms may be used with respect to the drawings. These and similar directional terms should not be construed to limit the scope in any manner. It will also be understood that other embodiments may be utilized without departing from the scope of the present invention, and that the detailed description is not to be taken in a limiting sense, and that elements may be differently positioned, or otherwise noted as in the appended claims without requirements of the written description being required thereto.
[0048] As used throughout, ranges are used as a shorthand for describing each and every value that is within the range. Any value within the range can be selected as the terminus of the range. In addition, all references cited herein are hereby incorporated by reference in their entireties. In the event of a conflict with a definition of the present disclosure and that of a cited reference, the present disclosure controls.
[0049] Various operations may be described as multiple discrete operations in turn, in a manner that may be helpful in understanding embodiments of the present invention; however, the order of description should not be construed to imply that these operations are order dependent.
[0050] The disintegrator 1 according to FIG. 1 is equipped with two electro motors 20 arranged opposite to each other and rotating in opposite direction co. Each electro motor 20 is coupled directly or indirectly via a gearbox to a rotor 3 that is equipped with multiple concentrically arranged rings 9 , 11 of hitting elements 5 , 7 (hereinafter also called blades). The rings 9 , 11 of hitting elements 5 , 7 of the two rotors 3 alternately engage with each other thus adjacent rings 9 , 11 of hitting elements 5 , 7 rotating in opposite direction co. The rotors 3 are encapsulated in a casing 21 that may be opened according to the illustration in FIG. 1 .
[0051] The whole disintegrator 1 is located on a mount 22 , e.g. a base frame that carries the electro motors 20 and the oppositely rotating rotors 3 .
[0052] The disintegrator 1 exhibits a filler 23 with a hopper 24 . As can be seen from FIG. 2 the filler 23 directs the material for micronization to the center of the rotors 3 . A sufficient airflow generated by the rotors 3 rotating in opposite direction co transports the material from the center of the rotors 3 to an outlet 25 at the circumference of the rotors causing multiple inter particle and particle-hitting-element collisions. At the outlet 25 the micronized material exits the casing 21 of the disintegrator 1 and either may be collected or again fed into the disintegrator 1 .
[0053] FIG. 2 clearly shows how the rings 9 , 11 of hitting elements 5 , 7 of the rotors 3 alternatively engage one another thus adjacent rings 9 , 11 of hitting elements rotating in opposite directions co.
[0054] FIGS. 3 to 6 show different views of hitting elements according to the prior art.
[0055] The hitting elements depicted in FIGS. 3 and 4 are of bladelike footprint that mainly generates an airflow transporting particles from the center of the rotors 3 to the circumference, thus generating inter particle collisions. However due to the pitch of the blades the time the particles stay within the disintegrator 1 is quite low.
[0056] FIGS. 5 and 6 show exemplary traces of articles from the center of the rotors 3 to the outer circumference where the particle exit the disintegrator 1 .
[0057] The improved device 1 claimed according to the present invention has the similar device construction like the disintegrators 1 from the prior art [J. Durek: Disintegrator and the method for the operation thereof, U.S. Pat. No. 4,406,409 A], [T. Lelas: Device for micronizing materials, HR990263 A2 (1999)] shown in FIGS. 1 and 2 .
[0058] An embodiment of a blade design (design of the hitting elements) according to the present invention is shown in FIGS. 5 to 11 . In this present embodiment a first ring 9 of trapezoidal blades carries hitting elements 5 with rectangular footprint and thus ob generally cubic shape. Another ring 11 , directly adjoining the first ring 9 carries triangular hitting elements 7 with a footprint of a right angled triangle. These triangular hitting elements 7 are tightly positioned and of generally prismatic shape. The different footprints of the blades 5 , 7 are shown in FIG. 5 .
[0059] FIG. 5 shows a cross-section in the plane of rotation of the hitting elements 5 , 7 thus depicting the different footprints of the hitting elements 5 , 7 on the different rotors 3 .
[0060] In the present embodiment the rotor 3 rotating in clockwise manner carries tree rings 9 of trapezoidal hitting elements 5 with rectangular footprint. The other rotor 3 (in the depicted view rotating counterclockwise) carries two rings 11 of triangular hitting elements 7 with triangular footprint. The rings 9 , 11 of hitting elements 5 , 7 engage alternately thus on a ring 9 rotating in clockwise manner follows a ring 11 rotating in opposite direction, i.e. counterclockwise manner.
[0061] Due to the different footprints of the hitting elements 5 , 7 and due to their arrangement the present embodiment provides an elongated time of the particles within the disintegrator 1 and thus a enlarged number of inter particle collisions, permanent milling between the hitting elements 5 , 7 of adjacent rings 9 , 11 and a enlarged number of collisions between particles and the hitting elements 5 , 7 .
[0062] The trace of a particle being micronized in a disintegrator 1 according to the present embodiment is depicted in FIG. 8 . Due to the arrangement of the hitting elements 5 , 7 the particles move in a loope-like manner thus resulting in a prolonged time within the disintegrator 1 .
[0063] The footprint of the triangular hitting elements 7 and their arrangement on their rotor 3 is depicted in FIGS. 9 to 11 .
[0064] FIG. 9 shows an enlarged cross-section of a triangular hitting element 7 according to the present embodiment. The hitting element 7 is of basically triangular footprint with rounded edges. As depicted in FIG. 9 the footprint is in the shape of a right angled triangle. The hypotenuse 15 of the right angled triangle is oriented tangentially to the outward circumference of the ring 11 built by the hitting elements 7 of it's respective ring. 11
[0065] The arrow in FIG. 9 indicates the direction of rotation co of the respective hitting element 7 , the longer cathetus 13 of the right enabled triangle thus being forward oriented.
[0066] According to FIG. 10 a center of the hypotenuse 15 of the triangular shaped footprint is perpendicularly cut by a radius r of the respective ring 11 . The longer cathetus 13 thus is inclined relative to the radius r by an angle a of 60 degrees. Accordingly (due to the fact that the triangle is right angled) the other cathetus 14 is inclined relative to the radius r by an angle β of minus 30 degrees.
[0067] FIG. 11 depicts two triangular hitting elements 7 arranged in a ring like manner. The hitting elements 7 are spaced from one another by a distance A of 15-100% of the length of the hitting elements 7 .
[0068] The longest side of the rectangular hitting elements 5 for example may be 30 mm. Accordingly the longer cathetus 13 of the triangular hitting elements 7 may be of the same length.
[0069] The course of the micronization process in the device 1 according to the present embodiment is actually the same as in the micronizer with hitting elements as disclosed in the prior art (shown in FIGS. 3 and 4 ). Material being micronized is added in the hopper 24 of the filler 23 . The latter brings the material into a central part of rotating discs 3 beside their axes. Due to a strong centrifugal force, particles of material being micronized pass through two or several layers of rotating hitting elements 5 , 7 (blades) of opposite discs rotating at high speed (about 5000-8000 rounds per minute) in opposite direction.
[0070] The influence of the shape of the blades on the efficiency the micronization has been studied by the use of the micronization device shown in FIGS. 1 and 2 from the prior art of the following technical characteristics:
(i) diameter of discs (0) of micronizer was 370 mm; (ii) number of layers of hitting elements (blades) on the discs was 3 on primary and 2 on secondary disc; (iii) number of blades on each of wreaths of discs was 20/16 (outer/inner wreath) from one side; and 18/16 (outer/inner wreath) from the other side of the micronizer; (iv) the rotation velocity was 10000 rpm.
[0075] The micronization device was equipped with two identical 20 kW power electro-motors that work at 220 V and 50 Hz.
[0076] Natural zeolite clinoptilolite, of the general formula:
[0000] (Me n+ ) x/n [(AlO 2 ) x (SiO 2 ) y ]·mH 2 O,
[0000] wherein Me=Na, K, Mg, Ca, Fe, Zn, Mn, Cr, was selected as a model substance of a hardness of 4 according to Mohs' scale. The starting material of an average particles size of 50-100 μm, was obtained from Zeocem a.s., Slovakia. The reason why zeolite is chosen is due to its NH 4 + sorption and retention capacity. It has been already demonstrated that zeolite can have significant improvement in sorption capacity, if micronized below one μm.
[0077] 1 kg of each sample of same zeolite clinoptilolite was micronized by using the device according to the prior art and three different hitting elements as depicted in FIGS. 5 , 6 and B. The disintegrators are characterized by the following data:
1. Plates formed according to U.S. Pat. No. 4,406,409 A ( FIG. 5 ; Micronization-1); 2. Slightly curved and indented plates according to HR990263 A2 ( FIG. 6 ; Micronizationt-2); and 3. The hitting elements according to the present invention ( FIG. 8 ; Micronization-3)
[0081] Prepared samples of micronized zeolite mineral were analyzed for particles size using a Malvern MasterSizer 2000 instrument and for NH 4 + ion sorption capacity with aqueous NH4Cl solution measured with an ion chromatograph DX-120 Dionex from the United States. The results of Micronization-1, Micronization-2 and Micronization-3 are shown in Table 1 and 2.
[0082] Table 1 shows the influence of the various shapes of hitting elements (blades) from different micronizing discs ( FIGS. 6 and 8 ) on efficacy of micronization of zeolite clinoptilolite of starting particle size 50-100 μm. The goal was to achieve larger amount of submicron particles.
[0000]
TABLE 1
MICRO-
MICRO-
MICRONIZATION-1
NIZATION-2
NIZATION-3
Particles
Volume (%)
Volume (%)
Volume (%)
size (μ.m.)
under
under
under
0.105
0.00
0.00
0.00
0.120
0.00
0.00
0.00
0.138
0.00
0.00
0.00
0.158
0.00
0.00
0.00
0.182
0.00
0.00
0.01
0.209
0.00
0.02
0.08
0.240
0.00
0.32
0.47
0.275
0.00
0.62
1.44
0.316
0.02
1.04
2.43
0.363
0.07
1.62
3.79
0.417
0.15
2.16
5.54
0.479
0.29
3.18
7.71
0.550
0.79
4.11
9.84
0.631
1.12
5.36
12.44
0.724
1.89
6.96
15.03
0.832
2.44
8.41
18.13
0.955
3.66
10.02
21.72
1.096
5.12
13.16
26.80
[0083] Table 2 shows the influence of the various shapes of hitting elements from different micronizing discs ( FIGS. 5 , 6 and 8 ) on particle specific surface are of zeolite clinoptilolite of starting particle specific surface area 0.9 m 2 /g.
[0000]
TABLE 2
MICRO-
MICRO-
MICRONIZATION 1
NIZATION 2
NIZATION 3
Specific
1.9
3.2
6.7
Surface Area
m 2 /g
[0084] Table 3 shows the influence of the various shapes of hitting elements from different micronizing discs ( FIGS. 5 , 6 and 8 ) on NH 4 + sorption of zeolite clinoptilolite of starting capacity 0.23 mmol/g.
[0000]
TABLE 3
MICRO-
MICRO-
MICRONIZATION-1
NIZATION-2
NIZATION-3
NH 4 + Sorption
0.48
0.78
0.94
Capacity
mmol/g
[0085] The results show that the process of MICRONIZATION-3 ( FIG. 8 ) with cube shaped hitting elements on one disc and tightly positioned triangular hitting elements on the other disc is superior to the other processes. It is also shown that MICRONIZATION-3 particles have much larger specific surface and capacity of ion sorption than those processed by other micronization types.
[0086] Further experiments show how repeated micronization (5 times in the same device, but with differently designed hitting elements affects particle size and crystalline surface deformation in order to enhance an amorphous portion of the surface and consequently improve solubility of poorly soluble pharmaceutically active ingredients.
[0087] 1 kg of each sample of ursolic acid (98% purity, Sigma Aldrich) of an average particle size of 30 pm was micronized five times in devices having different hitting elements. The discs were cooled through a feeder opening with liquid nitrogen spraying to avoid overheating of the heat-sensitive substance. The device used was according to the prior art while the hitting elements used are shown in FIGS. 5 , 6 and 8 .
[0088] The micronized samples were analyzed for particle size (Malvern MasterSizer 2000), while the extent of crystalline disorder of particles was quantified with isothermal calorimetry (IC TAM 3, TA instruments, USA). Data was recorded with proprietary software Digitam 4.2.
[0089] Table 4 shows the influence of the various shapes of hitting elements of different micronizing discs ( FIGS. 5 , 6 and 8 ) on ursolic acid particle size after five repeated micronization procedures.D
[0000]
TABLE 4
MICRO-
MICRONIZATIO-1
MICRONIZATION-2
NIZATION-3
Particles
Volume (%)
Volume (%)
Volume (%)
size (μ.m.)
under
under
under
0.105
0.00
0.00
0.00
0.120
0.00
0.00
0.00
0.138
0.00
0.00
0.00
0.158
0.00
0.00
0.28
0.182
0.00
0.00
1.38
0.209
0.00
0.12
2.73
0.240
0.00
0.46
3.69
0.275
0.01
1.19
5.39
0.316
0.06
1.97
8.42
0.363
0.23
2.83
11.76
0.417
0.50
4.09
14.01
0.479
0.87
5.36
19.32
0.550
1.12
7.01
25.19
0.631
2.02
9.13
31.12
0.724
3.29
11.51
36.14
0.832
4.78
13.61
42.72
0.955
6.12
16.29
50.02
1.096
8.44
19.17
59.80
[0090] Table 5 shows the influence of the various shapes of hitting elements from different micronizing discs ( FIGS. 3 , 4 and 5 ) on amorphous content of ursolic acid after five repeated micronization procedures.
[0000]
TABLE 5
M1CRO-
MICRO-
MICRONIZATION-1
NIZATION-2
NIZATION-3
Amorphous
3.68
6.12
19.23
Content
(%, w/w)
[0091] The tables above show that a reduction of particle size is not proportional to the number of repeated micronization processes; this is particularly notable in MICRONIZATION-1 and MICRONIZATION-2. It appears the smaller the particles are, the air friction affects them more, resulting in weaker collisions. This is predominant in discs having hitting elements with “turbine-like” design according to the state of the art devices. The hitting elements according to FIG. 7 show superior results, efficiently reducing particle size and inducing significant proportion of amorphous surface content.
[0092] Generally, it seems that major reason for effective and useful micronization from the design described in FIGS. 7-11 comes from the fact that the majority of particles is pushed back into compact repeated collisions ( FIG. 8 ) by the layers of tightly position hitting elements having extruded triangle shape as shown in FIGS. 7-11 . This way, particles return and collide repeatedly with other particles or hitting elements in the previous layer, while only a small amount of particles passes onto next flow layer. The flow of particles from this invention is shown in FIG. 8 . Such flow results in superior micronization compared to previous disintegrator devices, which relied mostly on turbine-like micronization effect. Particularly, airflow driven particle collisions, dominating in previous disintegrators are not sufficient for micronization below one (1) μm. Even after several repeated micronizing processes in prior art devices, particles do not reduce in size significantly, because airflow driven collisions become less important due to increased air friction and reduced kinetic energy of the particles. The smaller the particles become, the more air friction reduces impact velocity. The present invention demonstrates the importance of tight contact with the blades, which is important for adequate size reduction. Airflow based particle movements is used as vehicle to enable particle exit from the device by centrifugal force. To our best knowledge, it seems that the present invention is accomplishing superior micronization through four (4) major factors a) minimal air friction, b) compact particle inter-collisions, c) collision of particles with disc blades and, thus permanent milling between the different layers of blades resulting in improved micronization compared to state of the art devices.
[0093] The Use of the Device For Micronization From the Present Invention
[0094] The discs and hitting elements from the micronization device of the present invention can be built from various materials such as stainless steel 316, tungsten carbide or similar depending on the hardness of the materials to be micronized.
[0095] The micronization device of the present invention can be successfully used for milling of pure substances or mixtures of several substances, organic, inorganic or mixed compositions. Specifically it can be used for the processing of substances from the classes of raw materials, intermediates or final products in pharmaceutical, cosmetic, food, agrochemical or construction industry, in various kinds of chemical industries, agriculture, and in other fields of production.
[0096] A micronization process could induce defects in the crystalline network: these defects and increase of amorphous surface can improve the dissolubility of poorly soluble drugs. For example one such pharmaceutically active poorly soluble substance, is anti-ursodeoxycholic acid (UDCA). UDCA's solubility can be significantly improved by the use of the present device in a cost effective way, thus achieving better oral bioavailability.
[0097] The present invention can potentially enhance qualitative characteristics of various food ingredients, enabling cost-effective production processes and avoiding the need for chemical interventions. Micronizing macromolecular compounds can result in their more efficient processing, better solubility and oral bioavailability. Such modified molecules positively influence taste and nutritive characteristics. Micronized polysaccharides with high molecular mass, can also improve gelling characteristic and stability of gelatinous substances. Ratio of soluble fibers in food can be also increased by application of the present invention (breakage of chains, surface area increase) which is otherwise established only by addition of enzymes and implementation of heating process. During extraction of active ingredients from dry substances, the prior use of the present device on those substances can significantly improve related extraction time/quality and reduce the need for organic solvents due to smaller raw material particle size, increase of specific surface (better contact of solvent and raw material) and breakage of the bonds between active ingredient and raw material.
[0098] The present device can be also used for cost-effective processing of silica (including desert sand) to achieve more reactive nano size particles that can be used as advanced concrete additive for improvement of concrete properties or as added in certain percentage for brick production.
[0099] Herein mentioned examples of the use of the micronization device from the present invention are only illustrative and do not include all possible technical applications.
EXAMPLES
Example 1
Preparation of Pterostilbene Nanoparticles For Better Solubility—Bioavailability
[0100] 1.00 kg of Pterostilbene (98% purity, Organic Herb, China) 50 pm of crystalline particles as model substance were subjected to micronization from present invention with additional maintaining of low temperature (20° C.) of substance via slow liquid nitrogen stream flow addition through neck feeder. In this preparation discs with blades in the shape of cubes and extruded triangles were used ( FIG. 4 ), according to the present invention.
[0101] Such prepared samples of micronized Pterostilbene were subjected to particles size analyses and water solubility measurement. Average particle size after seven repeated processes of micronization were around 0.4 μm and significantly increased amorphous surface ratio (34% w/W). Solubility increased from 23 μg/ml, to 128 μg/ml.Z
Example 2
Preparation of Si0 2 Nanoparticles For Concrete Additive
[0102] 1.00 kg of white Si0 2 sand from Drava River was commercially obtained from the store in Croatia. The average particle size was between 0.1-2 mm. In this preparation discs with blades in the shape of cubes and extruded triangles were used ( FIG. 4 ), according to the present invention, but all together reinforced with tungsten carbide coating. The average particle size of sand after nine repeated micronization processes were 0.35 μm.
LIST OF REFERENCE NUMERALS
[0000]
1 device for micronization/disintegrator
3 rotors
5 trapezoidal/rectangular hitting element
7 triangular hitting element
9 first ring
11 other ring
13 longer cathetus
14 other cathetus
15 hypotenuse
20 electro motor
21 casing
22 mount
23 filler
24 hopper
A distance
d diameter
r radius
{acute over (ω)} direction of rotation
[0121] Having described at least one of the preferred embodiments of the present invention with reference to the accompanying drawings, it will be apparent to those skills that the invention is not limited to those precise embodiments, and that various modifications and variations can be made in the presently disclosed system without departing from the scope or spirit of the invention. Thus, it is intended that the present disclosure cover modifications and variations of this disclosure provided they come within the scope of the appended claims and their equivalents. | A device and method for operating the same for the micronization of substances in a device having two rotors driven in a direction (w) opposite to each other, each rotor carrying at least one row of multiple hitting elements forming a ring, said rings being arranged concentrically in, the rings of the different rotors engaging alternately with one another, the hitting elements being suitably arranged to provide transportation of the substance from inside the rings to the outside by effecting a suitable airflow, at least two, directly adjoining rings carrying hitting elements with different foot print wherein at least a first ring is equipped with trapezoidal hitting elements with trapezoidal foot print and at least one other ring, directly adjoining the first ring is equipped with triangular hitting elements with triangular foot print. | 1 |
FIELD OF THE INVENTION
[0001] The invention relates generally to the field of dental imagery, and in particular to a method and apparatus for effecting imagery of a prepared cavity in a tooth followed by automatic generation of a model to control automatic fabrication of a dental inlay for the cavity.
BACKGROUND OF THE INVENTION
[0002] The invention described herein relates generally to the following conventional situation. A dentist prepares a cavity of a decayed tooth to allow its restoration by means, e.g., of an inlay or a crown. After the preparation has been rendered, an impression of the cavity is taken, and is ordinarily sent to a dental laboratory. Contrary to such conventional techniques, there are different and more recent techniques which alleviate the role of the dental laboratory and fabricate the desired restorative piece in the dental office. In particular, the prepared cavity is registered by an electro-optic scan head. The data thus obtained can be complemented by operator input, using techniques from the CAD (Computer-Aided-Design) domain, and the final piece is fabricated with the aid of a miniature NC (numerical control) grinding machine.
[0003] U.S. Pat. No. 4,837,732 (Brandestini et al) describes a method for a dentist to record the shape in situ of teeth prepared for repair. The method involves the acquisition of data defining the three-dimensional shape of prepared teeth and their immediate vicinity. First, a video display shows a live image from a scan head, and the scan head is manually oriented relative to the prepared teeth while observing the image of the teeth on the video display. Thereafter the data produced by the scan head in a selected orientation generates corresponding depth and contrast images, and a depth image is processed based on the contrast image. This method also includes the step of superimposing graphic markers on the image displayed on the video display to facilitate an on-line alignment of the teeth displayed in the live image with reference data from previous data acquisitions.
[0004] The drawback to this method from the prior art is that it incorporates a registration scheme that can later interfere with the quality of the results, and also requires that the dentist be able to hold the scan head almost perfectly still at a specific point in the procedure. More specifically, the artifacts typically due to the 3D registration scheme (such as fringe, speckle and/or venetian blind effect) are cited in the patent as “intolerable and must be eliminated” since phase angle differences are used for measurement of the depth. Furthermore, the patent cites a need for a “quasi-instantaneous 3D acquisition following a trigger release”, the essential condition being that the orientation of the scan head must not change between the search and acquisition modes.
[0005] What happens in Brandestini et al is that the 3D result is overlaid on the search image allowing the dentist to verify the result. What is needed, however, is a system in which the 3D results are projected into the image using the projective equations of photogrammetry. This would cause the results to appear as if they were actually present in the scene at the time of image acquisition, allowing a much more accurate and precise evaluation.
[0006] Previous photogrammetric-based approaches, however, (see, e.g., U.S. Pat. No. 5,372,502) have not been too successful for a number of reasons. For example, such approaches have not been successful because it is hard to determine the exact relationship between the camera and the object. Moreover, it is also hard to precisely measure the object because teeth are fairly uniform in color and have little texture (which is in part why it is hard to determine the relationship discussed above).
SUMMARY OF THE INVENTION
[0007] The present invention is directed to overcoming one or more of the problems set forth above. Briefly summarized, according to one aspect of the present invention, a method (and system) for creating a dental model from a series of images of an intra-oral object includes the steps of (a) capturing a series of images of the intra-oral object from a plurality of capture positions, where the object includes common surface features and a control target arranged with respect to the object to provide control features; (b) measuring the control features from the control target imaged with the images of the object; (c) analytically generating a 3-dimensional model of the object by photogrammetrically aligning the measurements of the control features, thereby providing a photogrammetrically-aligned 3-dimensional model of the object while reducing image errors due to the variable orientation of the capture positions; and (d) adjusting the photogrammetrically aligned 3-dimensional model of the object by aligning the common features of the model to like features on the image of the object, thereby producing an aligned dental model from the series of images. In practice, the last stage involves the application of a 3-dimensional morphing algorithm to correct for the misalignment.
[0008] The principal advantage of the invention is that the use of photogrammetric projection methods and adjustment to control eliminates the need for a registration scheme, such as that used in Brandestini et al, which projects stripes of light onto the target and can result in unacceptable artifacts. Furthermore, under the present invention, there is no need to restrict the acquisition of the image(s) to a “quasi-instantaneous” state, as phase information is not used.
[0009] It becomes possible to measure the exact relationship between the camera and the intra-oral object because the use of a target provides something to measure, thus allowing the determination of the relationship between the camera and target. The use of 3D morphing addresses the matter of precisely measuring the object itself by projecting the data that is available into the picture and letting one see how well it fits—in the 3D object space. If correct, the model of the tooth should “fit” the tooth “skin tight”.
[0010] These and other aspects, objects, features and advantages of the present invention will be more clearly understood and appreciated from a review of the following detailed description of the preferred embodiments and appended claims, and by reference to the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0011] [0011]FIG. 1 is a block diagram of the method for creating dental models from imagery according to the invention.
[0012] [0012]FIG. 2 is a perspective diagram of a target useful with the method described in FIG. 1.
[0013] [0013]FIG. 3 is a block diagram of a morphing technique utilizing a database of generic tooth models.
[0014] [0014]FIG. 4 is a diagram of a dental system that utilizes the method shown in FIG. 1.
DETAILED DESCRIPTION OF THE INVENTION
[0015] Because dental image processing systems and methods are well known, the present description will be directed in particular to elements forming part of, or cooperating more directly with, apparatus and method in accordance with the present invention. Elements not specifically shown or described herein may be selected from those known in the art. Certain aspects of the embodiment to be described may be provided in software. Given the system as shown and described according to the invention in the following materials, software not specifically shown, described or suggested herein that is useful for implementation of the invention is conventional and within the ordinary skill in such arts. This is particularly true given the advanced technical state of conventional photogrammetry and the well-understood current automation of the photogrammetric process.
[0016] Referring initially to FIG. 4, a preferred embodiment of the invention is implemented in a system including an intra-oral camera 2 , a computer system 3 including instructions for implementing the invention and a machine tool 4 . In the schematic shown in FIG. 4, it should be understood that the interconnections between the camera 2 , the computer system 3 and the machine tool 4 are shown by arrows, and therefore not specifically indicated. These interconnections may take various forms, such as a cable or any other electromagnetic connection (such as an rf transmission), or the manual transfer of data from machine to machine. The camera 2 may be any type of conventional dental camera that is capable of capturing a reasonably high resolution image of an intra-oral object, such as the teeth 4 ; a preferred example is the intra-oral camera disclosed in commonly assigned, copending U.S. patent application Ser. No. 09/796,239, entitled “Intra-Oral Camera with Integral Display”, filed Feb. 28, 2001 in the names of J. P. Spoonhower, J. R. Squilla and J. T. Boland, and which is incorporated herein by reference.
[0017] The camera 2 is hand held by the dentist and several images are captured of the teeth; it is understood, however, that the orientation of the camera relative to the teeth will vary from one image to the next. The elimination of the effect of these different orientations on the subsequent measurements is one feature of the invention. The digitized data from the camera 2 is transferred to the computer system 3 for processing. The methodology of the invention is implemented by the computer system 3 in its processor 5 , and the imaging results may be interactively displayed on a monitor 6 . An operator using a keyboard 7 and/or a mouse 8 can manipulate a cursor 9 to perform measurements of the type that will be subsequently described. The output from the computer system 3 is a digitized three-dimensional surface pattern that is transferred to the machine tool 4 as a tool path program for the fabrication of a dental mold or a restorative piece. The program will direct a milling cutter 10 in the milling of the tooth mold or the restorative piece 11 from a suitable substrate, for example, ceramic or any other suitable machinable material.
[0018] The dental imaging method according to the invention employs a mensuration method that utilizes photogrammetric projection, analytical adjustment to control and three-dimensional morphing to develop accurate dental models. Mensuration, in this instance, refers to a measurement process involving several steps: (1) the identification of control points on the digitized image, (2) the stereoscopic transfer of those points to the overlapping images upon which they appear, and (3) the actual measurement of the image coordinates of the control points.
[0019] Photogrammetry generally is the science of measuring graphically by means of light, and more specifically the science of obtaining reliable measurements by means of photographs or other forms of imagery, such as electronic sensing by a sensor (see generally Manual of Photogrammetry, Fourth Edition, American Society of Photogrammetry, 1980). Photogrammetric projection refers to an image projection that uses an analytical representation of the physical model that describes the imaging process of the sensor. The term projection specifically refers to the concept of a light ray projecting from the intra-oral object, through the sensor lens, to the image plane, in this case using the physical model of the imaging process to determine where the points will be located.
[0020] Analytical adjustment to control refers to the process of correcting the set of parameters which describe the physical model, to a subset of known, or control, parameters. A least squares adjustment process is typically applied to a set of normal equations, derived from a set of linearized condition equations, which in turn are partial derivatives of the image coordinates with respect to the total parameter set. Details of the least squares process is well known to those of ordinary skill in this art and described, e.g., in the Manual of Photogrammetry, Fourth Edition, op. cit., pp. 77 - 88, which is incorporated herein by reference.
[0021] Three-dimensional morphing refers to the process of adjusting a 3-dimensional, object model to an image(s) of the object. This is accomplished by projecting a hypothesized 3-dimensional model of the object into an existing image (through the analytical physical model referred to above), detecting the misalignment between the true image and the projected, object model-derived image, and making corrections to the object model (which is then re-projected) to improve the fit. Techniques for three-dimensional morphing are well known in the art and will not be described in detail herein. For further information, reference may be made to articles by Frederic Pighin et al., “Synthesizing Realistic Facial Expressions from Photographs”, in Computer Graphics Proceedings, Annual Conference Series, 1998, pp. 75 - 83 and by Takaaki Akimoto et al., “Automatic Creation of 3D Facial Models”, in IEEE Computer Graphics & Applications, September 1993, pp. 16 - 22. In these articles, the specifics are directed toward facial models, but the technology application to teeth models would be the same.
[0022] Referring to FIGS. 1 and 2, the method according to the invention is shown, in which multiple images 12 of an intra-oral object (one or more teeth 14 ) are initially captured from several different aspects and/or positions by the camera 2 . For each image, one or more of the teeth 14 (e.g., a tooth 14 a ) includes a control target 16 , as shown in FIG. 2. (In practice, the tooth is typically either the original, unprepared tooth or the tooth as prepared (i.e., a tooth stump) for the restorative procedure.) The target 16 is rigid material, of saddle form, which rests on the tooth 14 a with length C along the side of the tooth. (Although not shown as such in FIG. 2, the control target 16 could span several teeth, such as both teeth 14 a and 14 b .) Lengths A, B, C, and D are known, and may be unequal. Angles included by the vertices 18 are also known; as will be described, the vertices 18 are the aforementioned known, or control, parameters that are used in the analytical adjustment to control. Several targets may be constructed in varying sizes to accommodate different size teeth. Generally, several images are taken from several different aspects/positions as the basis for a 3-dimensional view of the intra-oral object, including both the control parameters and certain common features on the tooth, such as the cusps and valleys describing the natural topographic surface of the tooth (or the tooth stump, if the intra-oral object is a prepared tooth).
[0023] The mensuration process involves the measurement of common features or parameters (the cusps and valleys) in a feature measurement stage 20 and the measurement of control features or parameters (the vertices 18 ) on the target 16 in a control measurement stage 22 . There are several ways to take these measurements. Referring to FIG. 4, these measurements may be interactively taken by an operator positioning the cursor 9 over the respective features on each of the multiple images 12 as they are displayed on the monitor 6 ; the coordinates of each measurement are then captured by the processor 5 . Alternatively, the processor 5 may employ appropriate conventional image processing algorithms to automatically locate each of the features; this may involve image enhancement and other feature improvement algorithms, as necessary. The measurements are then processed in a photogrammetric adjustment stage 24 in order to compute the object-space coordinates of any object point which is imaged in the multiple overlapping images from varying camera orientations; this process utilizes the aforementioned least squares process described in the Manual of Photogrammetry, Fourth Edition, op. cit. Basically, this is a multiray stereo intersection process that is used to locate each image point relative to the camera position. The result is a 3-dimensional model 26 of the tooth that has been processed with an analytical representation of the physical model which represents the imaging process of the sensor that captured the images.
[0024] However, the imaging device is usually a handheld camera that does not make a perfect geometric representation of the object, which creates errors due to the lack of certainty of knowledge about the image positions. One of the features of the invention is to tackle the problem of eliminating these errors, i.e., the camera's variability in orientation, before attempting to correct for errors in the actual model of the tooth. In this manner, the requirement (and problem) noted in the prior art, namely, that the scan head or imaging device must be held perfectly still, can be avoided. Therefore, an analytical adjustment using the control points (the vertices 18 ) to correct the estimates is made by analytically projecting the 3-D model 26 in an analytical projection stage 28 into an existing image (one of the multiple images 12 ), determining the misalignment of the control points (the vertices 18 ) between the model and the image in a misalignment stage 30 and refining the photogrammetric adjustments in a refinement stage 32 if the misalignment is unacceptable (decision 34 ). The projection is an analytical process, meaning that it is accomplished mathematically, and the determination of misalignment may be accomplished interactively (by using the cursor 9 ) or automatically with appropriate image processing algorithms. It is helpful to understand that this projection process utilizes the physical model representing the imaging process, therefore differing from a simple overlay of the 3-D model onto the image. Once these corrections are made, the variability in the model caused by the various camera orientations is reduced to an acceptable level, if not eliminated.
[0025] Once the control alignment is acceptable, the slopes and curves between the cusps and valleys in the model should either match, or be made to match, the corresponding features in the image of the tooth. Thus, it is necessary to determine the remaining misalignment of the model relative to the actual image in a misalignment determination stage 36 , that is, to determine the misalignment (if any) of the common features in the model with respect to the same features in the actual image. If misalignment is present (decision 38 ), a three-dimensional morphing stage 40 is initiated for adjusting the 3-dimensional object model in an adjustment stage 42 to an image(s) of the object. (This changes the 3-dimensional position of points in the model without affecting the prior alignment adjustment regarding the camera orientation.) This is accomplished in a projection stage 44 by projecting the hypothesized 3-dimensional model of the object into one of the existing images (through the analytical physical model referred to above) of the intra-oral object. Then, the misalignment between the true image and the projected, object model-derived image is detected in a misalignment stage 46 . If the misalignment is acceptable (decision 48 ), the process is ended; otherwise, corrections are made to the object model in the stages 40 and 42 (which is then re-projected) to improve the fit.
[0026] At this point, an acceptable model of the tooth has been generated and may be used in subsequent processing, such as in the fabrication of the desired restorative piece, either in a laboratory or in the dental office by use of the machine tool 4 . It should be understood that in addition to teeth, other dental prosthetics can be modeled in accordance with the invention, including without limitation bridges, veneers and other dental restorative units. Moreover, various other types of fabrication may be employed without limitation in addition to milling or cutting, such as injection molding.
[0027] [0027]FIG. 3 represents an alternative method for adjusting the 3-dimensional object model to an image(s) of the intra-oral object, that is, an alternative method to the logic represented by the elements 40 - 48 of FIG. 1. More specifically, in the alternative approach of FIG. 3, generic 3D models from a database 50 of such items may be used in addition to, or as a substitute for the 3D model provided in the elements 40 - 48 . This approach specifically addresses the issue around difficulty in accurately measuring the cusps and valleys, as they may not be as well defined as the target vertices, by allowing a generic tooth model to be used instead. This essentially means that in FIG. 1, the 3-D model 26 can be eliminated, or more correctly, reduced to only creating a 3D model of the target (vs. the tooth and target) and proceeding from there.
[0028] The invention has been described with reference to a preferred embodiment. However, it will be appreciated that variations and modifications can be effected by a person of ordinary skill in the art without departing from the scope of the invention.
PARTS LIST 2 camera 3 computer system 4 machine tool 5 processor 6 monitor 7 keyboard 8 mouse 9 cursor 10 milling cutter 11 restorative piece 12 multiple images 14 teeth 14a tooth 14b tooth 16 control target 18 vertices 20 feature measurement stage 22 control measurement stage 24 photogrammetric stage 26 3-D model 28 projection stages 30 misalignment stage 32 refinement stage 34 decision 36 misalignment stage 38 decision 40 3-D morphing stage 42 adjustment stage 44 projection stage 46 misalignment stage 48 decision 50 database of 3-D models | Creating a dental model from a series of images of an intra-oral object includes the steps of (a) capturing a series of images of an intra-oral object from a plurality of capture positions, where the object includes common surface features and a control target arranged with respect to the object to provide control features; (b) measuring the common features from the series of images of the object and the control features from the control target imaged with the images of the object; (c) analytically generating a 3-dimensional model of the object by photogrammetrically aligning the measurements of the control features, thereby reducing image errors due to the variability of the capture positions; and (d) adjusting the photogrammetrically aligned 3-dimensional model of the object by aligning the common features of the model to like features on the image of the object, thereby producing an aligned dental model from the series of images. | 0 |
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a National Phase Entry of International Patent Application No. PCT/EP2015/054099, filed on Feb. 26, 2015, which claims priority to French Patent Application Serial No. 1451648, filed on Feb. 28, 2014, both of which are incorporated by reference herein.
TECHNICAL FIELD
[0002] The present invention is applicable to the field of lubricants, and more particularly to the field of lubricants for motor vehicles. The invention relates to a lubricant composition comprising metal nanoparticles. More particularly, the invention relates to a lubricant composition comprising an anti-wear additive and metal nanoparticles. The lubricant composition according to the invention simultaneously has good stability as well as good, long-lasting friction properties.
[0003] The present invention also relates to a process for the lubrication of a mechanical part utilizing this lubricant composition. The present invention also relates to a composition of the additive-concentrate type comprising an anti-wear additive and metal nanoparticles.
BACKGROUND
[0004] Motor vehicle transmission components operate under a high load and high speeds. The oils for these transmission components must therefore be particularly efficient at protecting parts against wear, and in particular must have good properties for reducing friction on the surface of the components. Thus, if the friction level is not adapted to the geometry of the parts, wear occurs on the cone-ring assembly. The friction level can be adjusted by adding friction modifiers to these oils for gear boxes.
[0005] Moreover, the general introduction of motor vehicles on a global scale since the end of the last century poses problems relating to global warming, pollution, safety and use of natural resources, in particular the depletion of petroleum reserves. Following establishment of the Kyoto protocol, new standards protecting the environment require the car industry to construct vehicles having reduced pollutant emissions and fuel consumption. As a result, the engines of these vehicles are subject to increasingly stringent technical constraints: in particular they run more quickly, at increasingly high temperatures, and are required to consume less and less fuel.
[0006] The nature of engine lubricants for automobiles has an influence on the emission of pollutants and on fuel consumption. Engine lubricants for automobiles, called energy-saving or “fuel-eco”, have been developed in order to meet these new requirements.
[0007] Improvement in the energy performance of lubricant compositions can be obtained in particular by mixing friction modifiers into base oils. Among the friction modifiers, organometallic compounds comprising molybdenum are commonly used. In order to obtain good friction reduction properties, a sufficient quantity of molybdenum must be present in the lubricant composition.
[0008] However, these compounds have the drawback of causing the formation of sediments when the lubricant composition has too high a content of elemental molybdenum. The poor solubility of these compounds modifies, or even degrades the properties of the lubricant composition, in particular its viscosity. Now, a composition which is too viscous or not viscous enough militates against the movement of the mobile parts, easy starting of an engine, the protection of an engine when it has reached its operating temperature, and therefore ultimately causes in particular an increase in fuel consumption.
[0009] Moreover, these compounds contribute to an increase in the level of ash, reducing their potential for use in a lubricant composition, in particular in Europe. It is also known to formulate lubricant compositions comprising friction modifier compounds of the organomolybdenum type with organophosphorus- and/or organosulphur- and/or organophosphorus/sulphur-containing anti-wear and extreme-pressure compounds, in particular in order to improve the anti-wear properties of these engine or transmission oils.
[0010] Other compounds for reducing friction have been described as possibly being useful in the lubrication of mechanical parts, in particular of the parts of an engine. Document CN 101691517 describes an engine oil comprising tungsten disulphide nanoparticles, making it possible to improve the service life of the engine and reduce fuel consumption. However, the content of tungsten disulphide nanoparticles ranges from 15 to 34%, which can lead to risks of instability of the oil over time.
[0011] Moreover, the combination of nanoparticles and anti-wear compounds in grease compositions has been described, for example in document WO 2007/085643. However, this document only describes grease compositions and does not describe any engine or transmission lubricant.
[0012] It would therefore be desirable to have available a lubricant composition, in particular for motor vehicles, which is not a grease and which is both stable and has good friction reduction properties. It would also be desirable to have available a lubricant composition, in particular for motor vehicles, which is not a grease and the performances of which last over time. It would also be desirable to have available a lubricant composition, in particular for motor vehicles, which is not a grease and has good friction reduction properties while retaining satisfactory anti-flaking properties.
[0013] An objective of the present invention is to provide a lubricant composition overcoming some or all of the aforementioned drawbacks. Another objective of the invention is to provide a lubricant composition that is stable and easy to utilize. Another objective of the present invention is to provide a lubrication process making it possible in particular to reduce friction on the surface of mechanical parts, and more particularly of an engine or of a transmission component of motor vehicles.
SUMMARY
[0014] The invention thus relates to a lubricant composition with kinematic viscosity at 100° C., measured according to standard ASTM D445, ranging from 4 to 50 cSt and comprising at least one base oil, at least one compound comprising a dithiophosphate group and metal nanoparticles at a content by weight ranging from 0.01 to 2% with respect to the total weight of the lubricant composition. Surprisingly, the applicant found that the presence of a compound comprising a dithiophosphate group in a lubricant composition comprising at least one base oil and metal nanoparticles makes it possible to give said composition very good friction reduction properties. Moreover, the applicant found that the combination of a compound comprising a dithiophosphate group and metal nanoparticles in a lubricant composition makes it possible to maintain this reduction of friction over time. Without being bound by a particular theory, this maintenance of the effectiveness of friction reduction over time might be explained by the protection against oxidation of the metal nanoparticles by the compound comprising a dithiophosphate group, thus prolonging the action of the metal nanoparticles on the surface of a mechanical part, and more particularly of a transmission component or of a motor vehicle engine. Thus, the present invention makes it possible to formulate stable lubricant compositions comprising a reduced content of metal nanoparticles and having, however, remarkable friction reduction properties.
[0015] Advantageously, the lubricant compositions according to the invention have remarkable friction reduction properties that are maintained over time. Advantageously, the lubricant compositions according to the invention have good stability as well as viscosity that does not vary, or only very slightly. Advantageously, the lubricant compositions according to the invention have satisfactory anti-flaking properties. Advantageously, the lubricant compositions according to the invention have a reduced risk of oxidation. Advantageously, the lubricant compositions according to the invention have remarkable fuel saving properties.
[0016] In an embodiment, the lubricant composition essentially consists of at least one base oil, at least one compound comprising a dithiophosphate group and at least metal nanoparticles at a content by weight ranging from 0.01 to 2% with respect to the total weight of the lubricant composition. The invention also relates to an engine oil comprising a lubricant composition as defined above. The invention also relates to a transmission oil comprising a lubricant composition as defined above.
[0017] The invention also relates to the use of a lubricant composition as defined above for the lubrication of a mechanical part, preferably of a transmission component or of a vehicle engine, advantageously of motor vehicles. The invention also relates to the use of a lubricant composition as defined above for reducing friction on the surface of a mechanical part, preferably of a transmission component or of a vehicle engine, advantageously of motor vehicles. The invention also relates to the use of a lubricant composition as defined above for reducing the fuel consumption of vehicles, in particular of motor vehicles.
[0018] The invention also relates to a process for the lubrication of a mechanical part, preferably of a transmission component or of a vehicle engine, advantageously of motor vehicles, said process comprising at least one step of bringing the mechanical part into contact with a lubricant composition as defined above. The invention also relates to a process for reducing the friction on the surface of a mechanical part, preferably of a transmission component or of a vehicle engine, advantageously of motor vehicles, comprising at least bringing the mechanical part into contact with a lubricant composition as defined above. The invention also relates to a process for reducing the fuel consumption of a vehicle, in particular of a motor vehicle, comprising at least one step of bringing a mechanical part of the vehicle engine into contact with a lubricant composition as defined above. The invention also relates to the use of a compound comprising a dithiophosphate group for decreasing the oxidation of a lubricant composition comprising at least one base oil and metal nanoparticles. The invention also relates to a composition of the additive-concentrate type comprising at least one compound comprising a dithiophosphate group and tungsten disulphide nanoparticles.
DETAILED DESCRIPTION
[0019] The percentages given below correspond to percentages by mass of active ingredient.
Metal Nanoparticles
[0020] The lubricant composition according to the invention comprises metal nanoparticles at a content by weight ranging from 0.01 to 2% with respect to the total weight of the lubricant composition. By “metal nanoparticles”, is meant in particular metal particles, generally solid, the average size of which is less than or equal to 600 nm.
[0021] Advantageously, the metal nanoparticles are constituted by at least 80% by mass of at least one metal, or by at least 80% by mass of at least one metal alloy or by at least 80% by mass of at least one metal, in particular transition metal, chalcogenide with respect to the total mass of the nanoparticle. Advantageously, the metal nanoparticles are constituted by at least 90% by mass of at least one metal, or by at least 90% by mass of at least one metal alloy or by at least 90% by mass of at least one metal, in particular transition metal, chalcogenide with respect to the total mass of the nanoparticle. Advantageously, the metal nanoparticles are constituted by at least 99% by mass of at least one metal, or by at least 99% by mass of at least one metal alloy or by at least 99% by mass of at least one metal, in particular transition metal, chalcogenide with respect to the total mass of the nanoparticle, the remaining 1% being constituted by impurities.
[0022] Advantageously, the metal of which the metal nanoparticle is constituted can be selected from the group constituted by tungsten, molybdenum, zirconium, hafnium, platinum, rhenium, titanium, tantalum, niobium, cerium, indium and tin, preferably molybdenum or tungsten, advantageously tungsten. The metal nanoparticles can have the form of spheres, lamellas, fibres, tubes, and fullerene-type structures. Advantageously, the metal nanoparticles used in the compositions according to the invention are solid metal nanoparticles having a fullerene-type (or fullerene-like) structure and are represented by the formula MX n in which M represents a transition metal, X a chalcogen, with n=2 or n=3 depending on the oxidation state of the transition metal M.
[0023] Preferably, M is selected from the group constituted by tungsten, molybdenum, zirconium, hafnium, platinum, rhenium, titanium, tantalum and niobium. More preferably, M is selected from the group constituted by molybdenum and tungsten. Even more preferably, M is tungsten.
[0024] Preferably, X is selected from the group constituted by oxygen, sulphur, selenium and tellurium. Preferably, X is selected from sulphur or tellurium. Even more preferably, X is sulphur.
[0025] Advantageously, the metal nanoparticles according to the invention are selected from the group constituted by MoS 2 , MoSe 2 , MoTe 2 , WS 2 , WSe 2 , ZrS 2 , ZrSe 2 , HfS 2 , HfSe 2 , PtS 2 , ReS 2 , ReSe 2 , TiS 3 , ZrS 3 , ZrSe 3 , HfS 3 , HfSe 3 , TiS 2 , TaS 2 , TaSe 2 , NbS 2 , NbSe 2 and NbTe 2 . Preferably, the metal nanoparticles according to the invention are selected from the group constituted by WS 2 , WSe 2 , MoS 2 and MoSe 2 , preferentially WS 2 and MoS 2 , preferentially WS 2 . The nanoparticles according to the invention advantageously have a fullerene-type structure.
[0026] Initially, the term fullerene denotes a closed convex polyhedron nanostructure, composed of carbon atoms. The fullerenes are similar to graphite, composed of sheets of linked hexagonal rings, but they contain pentagonal, and sometimes heptagonal rings, which prevent the structure from being flat.
[0027] Studies of the fullerene-type structures have shown that this structure was not limited to the carbon-containing materials, but was capable of being produced in all the nanoparticles of materials in the form of sheets, in particular in the case of the nanoparticles comprising chalcogens and transition metals. These structures are analogous to that of the carbon fullerenes and are called inorganic fullerenes or fullerene-type structures (or “Inorganic Fullerene-like materials”, also denoted “IF”). The fullerene-type structures are described in particular by Tenne, R., Margulis, L., Genut M. Hodes, G. Nature 1992, 360, 444. The document EP 0580 019 describes in particular these structures and their synthesis process.
[0028] In a preferred embodiment of the invention, the metal nanoparticles are closed structures, of the spherical type, more or less perfect depending on the synthesis processes used. The nanoparticles according to the invention are concentric polyhedrons with a multilayer or sheet structure. This is referred to as an “onion” or “nested polyhedron” structure. In an embodiment of the invention, the metal nanoparticles are multilayer metal nanoparticles comprising from 2 to 500 layers, preferably from 20 to 200 layers, advantageously from 20 to 100 layers.
[0029] The average size of the metal nanoparticles according to the invention ranges from 5 to 600 nm, preferably from 20 to 400 nm, advantageously from 50 to 200 nm. The size of the metal nanoparticles according to the invention can be determined using images obtained by transmission electron microscopy or by high resolution transmission electron microscopy. It is possible to determine the average size of the particles from measurement of the size of at least 50 solid particles visualized on transmission electron microscopy photographs. The measured median value of the distribution histogram of the sizes of the solid particles is the average size of the solid particles used in the lubricant composition according to the invention.
[0030] In an embodiment of the invention, the average diameter of the primary metal nanoparticles according to the invention ranges from 10 to 100 nm, preferably from 30 to 70 nm. Advantageously, the content by weight of metal nanoparticles ranges from 0.05 to 2%, preferably from 0.1 to 1%, advantageously from 0.1 to 0.5% with respect to the total weight of the lubricant composition. As an example of metal nanoparticles according to the invention, the product NanoLub Gear Oil Concentrate marketed by the company Nanomaterials may be mentioned, being presented in the form of a dispersion of multilayer nanoparticles of tungsten disulphide in a mineral oil or oil of the PAO (Poly Alfa Olefin) type.
Compound Comprising a Dithiophosphate Group
[0031] The lubricant composition according to the invention comprises at least one compound comprising a dithiophosphate group. With a view to simplification of the description, the compound comprising a dithiophosphate group is called “dithiophosphate” in the remainder of the present description. The dithiophosphate, without being limitative, can be selected from the ammonium dithiophosphates, the amine dithiophosphates, the ester dithiophosphates and the metal dithiophosphates, alone or in a mixture.
[0032] In an embodiment of the invention, the dithiophosphate is selected from the ammonium dithiophosphates of formula (I):
[0000]
[0000] in which R1 and R2 represent, independently of one another, a hydrocarbon-containing group, optionally substituted, comprising from 1 to 30 carbon atoms.
[0033] In a preferred embodiment of the invention, R1 and R2 represent, independently of one another, a hydrocarbon-containing group, optionally substituted, comprising from 2 to 24 carbon atoms, more preferentially from 3 to 18 carbon atoms, advantageously from 5 to 12 carbon atoms. In another preferred embodiment of the invention, R1 and R2 represent, independently of one another, an unsubstituted hydrocarbon-containing group, and said hydrocarbon-containing group can be an alkyl, alkenyl, alkynyl, phenyl or benzyl group. In another preferred embodiment of the invention, R1 and R2 represent, independently of one another, a linear or branched alkyl hydrocarbon-containing group, more preferentially a linear alkyl hydrocarbon-containing group. In another preferred embodiment of the invention, R1 and R2 represent, independently of one another, a hydrocarbon-containing group optionally substituted by at least one oxygen, nitrogen, sulphur and/or phosphorus atom, preferably by at least one oxygen atom. As examples of ammonium dithiophosphate, the ammonium dimethyldithiophosphates, the ammonium diethyldithiophosphates and the ammonium dibutyldithiophosphates can be mentioned.
[0034] In another embodiment of the invention, the dithiophosphate is selected from the amine dithiophosphates of general formula (II):
[0000]
[0035] in which:
R3 and R4 represent, independently of one another, a hydrocarbon-containing group, optionally substituted, comprising from 1 to 30 carbon atoms, R5, R6 and R7 represent, independently of one another, a hydrogen atom or a hydrocarbon-containing group with 1 to 30 carbon atoms, it being understood that at least one of the R5, R6 and R7 groups does not represent a hydrogen atom.
[0038] In a preferred embodiment of the invention, R3 and R4 represent, independently of one another, a hydrocarbon-containing group, optionally substituted, comprising from 2 to 24 carbon atoms, more preferentially from 3 to 18 carbon atoms, advantageously from 5 to 12 carbon atoms. In another preferred embodiment of the invention, R3 and R4 represent, independently of one another, an unsubstituted hydrocarbon-containing group, and said hydrocarbon-containing group can be an alkyl, alkenyl, alkynyl, phenyl or benzyl group. In another preferred embodiment of the invention, R3 and R4 represent, independently of one another, a linear or branched alkyl hydrocarbon-containing group, more preferentially a linear alkyl hydrocarbon-containing group. In another preferred embodiment of the invention, R3 and R4 represent, independently of one another, a hydrocarbon-containing group optionally substituted by at least one oxygen, nitrogen, sulphur and/or phosphorus atom, preferably by at least one oxygen atom. In another preferred embodiment of the invention, R5, R6 and R7 represent, independently of one another, a hydrocarbon-containing group comprising from 2 to 24 carbon atoms, more preferentially from 3 to 18 carbon atoms, advantageously from 5 to 12 carbon atoms.
[0039] In another embodiment of the invention, the dithiophosphate is selected from the ester dithiophosphates of general formula (III):
[0000]
[0040] in which:
R8 and R9 represent, independently of one another, a hydrocarbon-containing group, optionally substituted, comprising from 1 to 30 carbon atoms, R10 and R11 represent, independently of one another, a hydrocarbon-containing group comprising from 1 to 18 carbon atoms.
[0043] In a preferred embodiment of the invention, R8 and R9 represent, independently of one another, a hydrocarbon-containing group, optionally substituted, comprising from 2 to 24 carbon atoms, more preferentially from 3 to 18 carbon atoms, advantageously from 5 to 12 carbon atoms. In another preferred embodiment of the invention, R8 and R9 represent, independently of one another, an unsubstituted hydrocarbon-containing group, and said hydrocarbon-containing group can be an alkyl, alkenyl, alkynyl, phenyl or benzyl group. In another preferred embodiment of the invention, R8 and R9 represent, independently of one another, a linear or branched alkyl hydrocarbon-containing group, more preferentially a linear alkyl hydrocarbon-containing group.
[0044] In another preferred embodiment of the invention, R8 and R9 represent, independently of one another, a hydrocarbon-containing group optionally substituted by at least one oxygen, nitrogen, sulphur and/or phosphorus atom, preferably by at least one oxygen atom. In another preferred embodiment of the invention, R8 and R9 represent, independently of one another, a hydrocarbon-containing group comprising from 2 to 6 carbon atoms. In another preferred embodiment of the invention, R10 and R11 represent, independently of one another, a hydrocarbon-containing group comprising from 2 to 6 carbon atoms.
[0045] In another embodiment, the dithiophosphate is selected from the metal dithiophosphates of general formula (IV):
[0000]
[0046] in which:
R12 represents a linear or branched, saturated or unsaturated, substituted or unsubstituted alkyl group comprising from 1 to 30 carbon atoms; R13 represents a linear or branched, saturated or unsaturated, substituted or unsubstituted alkyl group comprising from 1 to 30 carbon atoms; M represents a metal cation, preferably a Zn 2+ cation; n represents the valency of the metal cation.
[0051] In a preferred embodiment of the invention, the metal is selected from the group constituted by zinc, aluminium, copper, iron, mercury, silver, cadmium, tin, lead, antimony, bismuth, thallium, chromium, molybdenum, cobalt, nickel, tungsten, sodium, calcium, magnesium, manganese and arsenic. The preferred metals are zinc, molybdenum, antimony, preferably zinc and molybdenum. In a preferred embodiment of the invention, the metal is zinc. Mixtures of metals can be used. The metal dithiophosphates are neutral, as exemplified in formula (IV), or basic when a stoichiometric excess of metal is present.
[0052] In a preferred embodiment of the invention, R12 and R13 represent, independently of one another, a hydrocarbon-containing group, optionally substituted, comprising from 2 to 24 carbon atoms, more preferentially from 3 to 18 carbon atoms, advantageously from 5 to 12 carbon atoms. In another preferred embodiment of the invention, R12 and R13 represent, independently of one another, an unsubstituted hydrocarbon-containing group, and said hydrocarbon-containing group can be an alkyl, alkenyl, alkynyl, phenyl or benzyl group. In another preferred embodiment of the invention, R12 and R13 represent, independently of one another, a linear or branched alkyl hydrocarbon-containing group, more preferentially a linear alkyl hydrocarbon-containing group. In another preferred embodiment of the invention, R12 and R13 represent, independently of one another, a hydrocarbon-containing group optionally substituted by at least one oxygen, nitrogen, sulphur and/or phosphorus atom, preferably by at least one oxygen atom.
[0053] Advantageously, the dithiophosphate according to the invention is a zinc dithiophosphate of formula (IV-a) or of formula (IV-b):
[0000]
[0000] in which R12 and R13 are as defined above.
[0054] As metal dithiophosphate according to the invention, Additin® RC 3038, Additin® RC 3045, Additin® RC 3048, Additin® RC 3058, Additin® RC 3080, Additin® RC 3180, Additin® RC 3212, Additin® RC 3580, Kikulube® Z112, Lubrizol® 1371, Lubrizol® 1375, Lubrizol® 1395, Lubrizol® 5179, Oloa® 260, Oloa® 267 can for example be mentioned. In an embodiment of the invention, the content by weight of the compound comprising a dithiophosphate group ranges from 0.1 to 5%, preferentially from 0.2 to 4%, more preferentially from 0.5 to 2%, advantageously from 0.5 to 1.5% with respect to the total weight of the lubricant composition.
Base Oil
[0055] The lubricant compositions according to the invention can contain any type of lubricant base oil, mineral, synthetic or natural, animal or vegetable suited to their use. The base oil or oils used in the lubricant compositions according to the present invention can be oils of mineral or synthetic origin, of Groups I to V according to the classes defined in the API classification (or their equivalents according to the ATIEL classification) as summarized below, alone or in a mixture.
[0000]
TABLE I
Saturates
Sulphur
Viscosity index
content
content
(VI)
Group I Mineral
<90%
>0.03%
80 ≦ VI < 120
oils
Group II
≧90%
≦0.03%
80 ≦ VI < 120
Hydrocracked oils
Group III
≧90%
≦0.03%
≧120
Hydrocracked or
hydro-isomerized
oils
Group IV
Poly Alpha Olefins (PAO)
Group V
Esters and other bases not included in bases of
Groups I to IV
[0056] The mineral base oils according to the invention include any type of bases obtained by atmospheric and vacuum distillation of crude oil, followed by refining operations such as solvent extraction, deasphalting, solvent dewaxing, hydrotreatment, hydrocracking and hydroisomerization, hydrofinishing. The base oils of the lubricant compositions according to the invention can also be synthetic oils, such as certain esters of carboxylic acids and alcohols, or poly alpha olefins. The poly alpha olefins used as base oils are obtained for example from monomers having from 4 to 32 carbon atoms (for example octene, decene), and have a viscosity at 100° C. between 1.5 and 15 cSt measured according to standard ASTM D445. Their weight-average molecular weight is typically between 250 and 3000 measured according to standard ASTM D5296. Mixtures of synthetic and mineral oils can also be used.
[0057] There is no limitation on the use of any particular lubricant base for producing the lubricant compositions according to the invention, except that they must have properties, in particular viscosity, viscosity index, sulphur content, oxidation resistance, suited to use in a gearbox, in particular in a motor vehicle gearbox, in particular in a manual gearbox. In an embodiment of the invention, the lubricant bases represent at least 50% by weight, with respect to the total weight of the lubricant composition, preferentially at least 60%, or also at least 70%. Typically, they represent between 75 and 99.9% by weight, with respect to the total weight of the lubricant compositions according to the invention.
[0058] The lubricant composition according to the invention has a kinematic viscosity at 100° C. measured according to standard ASTM D445 ranging from 4 to 50 cSt. In an embodiment, the kinematic viscosity at 100° C. measured according to standard ASTM D445 of the composition according to the invention ranges from 4 to 45 cSt, preferably from 4 to 30 cSt. In a preferred embodiment of the invention, the lubricant compositions comprise at least one base of Group IV. In another preferred embodiment of the invention, the lubricant compositions have a viscosity index (VI) greater than 95 (standard ASTM 2270).
Other Additives
[0059] The lubricant compositions according to the invention can also contain any type of additive suitable for use in the formulations of transmission oils, for example one or more additives selected from the polymers, the antioxidants, the anti-corrosion additives, the friction modifiers different from the metal nanoparticles according to the invention and the dispersants, present in the usual contents required for the application. In an embodiment of the invention, the additive is selected from dispersants having a weight-average molecular weight greater than or equal to 2000 Da. According to the invention, the weight-average molecular weight of the dispersant is assessed according to standard ASTM D5296. By dispersant within the meaning of the present invention, is meant more particularly any compound that improves the maintenance of the metal nanoparticles in suspension.
[0060] In an embodiment of the invention, the dispersant can be selected from the compounds comprising at least one succinimide group, the polyolefins, the olefin copolymers (OCP), the copolymers comprising at least one styrene unit, the polyacrylates or their derivatives. By derivatives, is meant any compound comprising at least one group or a polymer chain as defined above. Advantageously, the dispersant according to the invention is selected from the compounds comprising at least one succinimide group.
[0061] In a preferred embodiment of the invention, the dispersant is selected from the compounds comprising at least one substituted succinimide group or the compounds comprising at least two substituted succinimide groups, the succinimide groups being linked at their vertex bearing a nitrogen atom by a polyamine group. By substituted succinimide group within the meaning of the present invention, is meant a succinimide group at least one of the carbon-containing vertices of which is substituted by a hydrocarbon-containing group comprising from 8 to 400 carbon atoms. In a preferred embodiment of the invention, the dispersant is selected from the polyisobutylene succinimide-polyamines.
[0062] Advantageously, the dispersant according to the invention has a weight-average molecular weight ranging from 2000 to 15000 Da, preferably ranging from 2500 to 10000 Da, advantageously from 3000 to 7000 Da. Also advantageously, the dispersant has a number-average molecular weight greater than or equal to 1000 Da, preferably ranging from 1000 to 5000 Da, more preferentially from 1800 to 3500 Da, advantageously from 1800 to 3000 Da. According to the invention, the number-average molecular weight of the dispersant is assessed according to standard ASTM D5296. In a preferred embodiment of the invention, the content by weight of dispersant having a weight-average molecular weight greater than or equal to 2000 Da ranges from 0.1 to 10%, preferably from 0.1 to 5%, advantageously from 0.1 to 3% with respect to the total weight of the lubricant composition.
[0063] The polymers can be selected from the group of the shear-stable polymers, preferably from the group constituted by the ethylene and alpha-olefin copolymers, the polyacrylates such as polymethacrylates, the olefin copolymers (OCP), the ethylene propylene diene monomers (EPDM), the polybutenes, the copolymers of styrene and olefin, hydrogenated or not, or the copolymers of styrene and acrylate. The antioxidants can be selected from the amine-containing antioxidants, preferably the diphenylamines, in particular dialkylphenylamines, such as the octadiphenylamines, the phenyl-alpha-naphthyl amines, the phenolic antioxidants (dibutylhydroxytoluene BHT and derivatives) or sulphur-containing antioxidants (sulphurized phenates).
[0064] The friction modifiers can be compounds providing metallic elements that are different from the metal nanoparticles according to the invention, or an ash-free compound. Among the compounds providing metallic elements, the complexes of transition metals such as Mo, Sb, Sn, Fe, Cu, Zn, the ligands of which can be hydrocarbon-containing compounds containing oxygen, nitrogen, sulphur or phosphorus atoms, such as molybdenum dithiocarbamates or dithiophosphates, can be mentioned. The ash-free friction modifiers are of organic origin and can be selected from the monoesters of fatty acids and polyols, alkoxylated amines, alkoxylated fatty amines, amine phosphates, fatty alcohols, fatty epoxides, borated fatty epoxides, fatty amines or glycerol esters of fatty acid. By “fatty” is meant within the meaning of the present invention a hydrocarbon-containing group comprising from 8 to 24 carbon atoms.
[0065] The anti-corrosion additives can be selected from the phenol derivatives, in particular ethoxylated phenol derivatives and substituted by alkyl groups in the ortho position. The corrosion inhibitors can be dimercaptothiadiazole derivatives.
[0066] In an embodiment of the invention, the lubricant composition comprises:
from 75 to 99.89% of at least one base oil, from 0.01 to 2% of metal nanoparticles, from 0.1 to 5% of at least one compound comprising a dithiophosphate group.
[0070] In another embodiment of the invention, the lubricant composition essentially consists of:
75 to 99.89% of at least one base oil, 0.01 to 2% of metal nanoparticles, 0.1 to 5% of at least one compound comprising a dithiophosphate group.
All of the characteristics and preferences presented for the base oil, the metal nanoparticles and the compound comprising a dithiophosphate group also apply to the above lubricant compositions.
[0074] In an embodiment of the invention, the lubricant composition is not an emulsion. In another embodiment of the invention, the lubricant composition is anhydrous. The invention also relates to an engine oil comprising a lubricant composition according to the invention. The invention also relates to a transmission oil comprising a lubricant composition according to the invention. All of the characteristics and preferences presented for the lubricant composition also apply to the engine oil or transmission oil according to the invention.
The Parts
[0075] The lubricant composition according to the invention can lubricate at least one mechanical part or mechanical component, in particular bearings, gears, universal joints, transmissions, the pistons/rings/liners system, camshafts, clutch, manual or automatic gearboxes, axles, rocker arms, housings etc. In a preferred embodiment, the lubricant composition according to the invention can lubricate a mechanical part or a metal component of the transmission, clutch, axles, manual or automatic gearboxes, preferably manual. Thus, the invention also relates to the use of a lubricant composition as defined above for the lubrication of a mechanical part, preferably of a transmission component or of a vehicle engine, advantageously of motor vehicles.
[0076] The invention also relates to the use of a lubricant composition as defined above for reducing friction on the surface of a mechanical part, preferably of a transmission component or of a vehicle engine, advantageously of motor vehicles. The invention also relates to the use of a lubricant composition as defined above for reducing the fuel consumption of vehicles, in particular of motor vehicles. The invention also relates to the use of a lubricant composition as defined above for reducing the flaking of a mechanical part, preferably of a transmission component or of a vehicle engine, advantageously of motor vehicles. All of the characteristics and preferences presented for the lubricant composition also apply to the above uses.
[0077] The invention also relates to a process for the lubrication of a mechanical part, preferably of a transmission component or of a vehicle engine, advantageously of motor vehicles, said process comprising at least one step of bringing the mechanical part into contact with a lubricant composition as defined above. The invention also relates to a process for reducing the friction on the surface of a mechanical part, preferably of a transmission component or of a vehicle engine, advantageously of motor vehicles, comprising at least bringing the mechanical part into contact with a lubricant composition as defined above. The invention also relates to a process for reducing the fuel consumption of a vehicle, in particular of a motor vehicle comprising at least one step of bringing a mechanical part of the vehicle engine into contact with a lubricant composition as defined above. The invention also relates to a process for reducing the flaking of a mechanical part, preferably of a transmission component or of a vehicle engine, advantageously of motor vehicles, comprising at least bringing the mechanical part into contact with a lubricant composition as defined above. All of the characteristics and preferences presented for the lubricant composition also apply to the above processes.
[0078] The invention also relates to a composition of the additive-concentrate type comprising at least one compound comprising a dithiophosphate group and tungsten disulphide nanoparticles. All of the characteristics and preferences presented for the tungsten disulphide nanoparticles and the compound comprising a dithiophosphate group also apply to the above composition of the additive-concentrate type.
[0079] In an embodiment of the invention, at least one base oil can be added to the composition of the additive-concentrate type according to the invention, in order to obtain a lubricant composition according to the invention. All of the characteristics and preferences presented for the base oil also apply to the above embodiment.
[0080] The invention also relates to the use of a compound comprising a dithiophosphate group for decreasing the oxidation of a lubricant composition comprising at least one base oil and metal nanoparticles. All of the characteristics and preferences presented for the base oil, the metal nanoparticles and the compound comprising a dithiophosphate group also apply to the above use.
[0081] The different subjects of the present invention and their implementations will be better understood on reading the following examples. These examples are given as an indication, without being limitative in nature.
Examples
[0082] Lubricant compositions No. 1 to No. 4 were prepared from the following compounds:
a base oil of the PAO (poly alpha olefin) type of Grade 6 (viscosity at 100° C. in the region of 6 cSt measured according to standard ASTM D445), a mixture of tungsten disulphide nanoparticles at 20% of active ingredient in an oil (NanoLub Gear Oil Concentrate marketed by the company Nanomaterials), a compound comprising a dithiophosphate group: zinc dithiophosphate (Lz 1371 marketed by the company Lubrizol).
Lubricant compositions No. 1 to No. 4 are described in Table II; the percentages indicated are percentages by mass.
[0000]
TABLE II
Lubricant
composition
No. 1
No. 2
No. 3
No. 4
Base oil
100
99
99
98
Compound
1
1
comprising a
dithiophosphate
group
Tungsten disulphide
1
1
nanoparticles
(NanoLub Gear Oil
Concentrate)
Test 1: Assessment of the Friction Properties of Lubricant Compositions
[0086] It is a question of assessing the friction properties of lubricant compositions No. 1 to No. 4 by measuring the coefficient of friction. The coefficient of friction is assessed using a pin-on-plate linear tribometer under the following conditions:
type of steel: AISI 52100 (hardness=800 HV), roughness of the plate: 35 nm, temperature: 100° C., calculated contact pressure: 1.12 GPa, sliding speed: 3 mm/s humidity level: 35-45R (ambient atmosphere), test duration: 8 h.
Table III gives the average coefficient of friction of lubricant compositions No. 1 to No. 4; the average coefficient of friction represents the average of the values of the coefficient of friction obtained after 4 tests.
[0000]
TABLE III
Composition
No. 1
No. 2
No. 3
No. 4
Coefficient of
0.100
0.110
0.075
0.060
friction
[0094] These results show that the lubricant composition according to the invention No. 4 has improved friction properties, with respect to a lubricant composition comprising a compound comprising a dithiophosphate group according to the invention but not comprising metal nanoparticles (composition No. 2) and with respect to a composition comprising metal nanoparticles according to the invention but not comprising a compound comprising a dithiophosphate group (composition No. 3). These results thus show a synergy of activity of the combination of a compound comprising a dithiophosphate group and metal nanoparticles in a lubricant composition for significantly reducing the coefficient of friction, in particular for steel/steel contacts. These results also show that the effectiveness of friction reduction is maintained over time by using a lubricant composition according to the invention. Moreover, lubricant composition No. 4 has satisfactory stability. | The present disclosure relates to a lubricant composition including an anti-wear additive and metal nanoparticles. The lubricant composition according to the disclosure has, simultaneously, good stability as well as good, long-lasting friction properties. | 2 |
BACKGROUND
In the hydrocarbon recovery industry boreholes are drilled to access hydrocarbon bearing formations for the purpose of extracting target fluids be the fluid gas, oil or a combination of fluids. While traditionally boreholes were drilled substantially vertically and therefore orientation of a bottom hole assembly could be relatively accurately tracked by tracking the orientation of the string at the surface, orientation in highly deviated or horizontal wells that are more common today is difficult and accuracy is limited. This is due in part to the frictional factors encountered as a string of several thousand feet is driven into the low side borehole wall. Because it is difficult to measure the friction all the way up the string, it is difficult to resolve the forces that act on the string and affect actual orientation downhole relative to apparent orientation at the surface.
Being able to accurately determine orientation in the downhole environment facilitates many operational interests. Therefore, the art is always receptive to new methods and apparatus that improve or enable orientation in the downhole environment.
SUMMARY
A pressure orienting swivel arrangement including a weight assembly and a pin adapter reactably interengagable with the weight assembly to orient the pin adapter to the weight assembly.
A pressure orienting swivel arrangement including a housing, a spring compression mandrel within the housing, a spring disposed about the spring compression mandrel, a weight assembly rotatably supported in the housing, and a pin adaptor rotatably supported within the housing and reactably interengagable with the weight assembly to accept a torque from the weight assembly.
A method for orienting a downhole tool including gravitationally orienting a weight assembly, interengaging a pin adapter and inducing rotation in the pin adapter with the weight assembly.
BRIEF DESCRIPTION OF THE DRAWINGS
Referring now to the drawings wherein like elements are numbered alike in the several Figures:
FIG. 1 is a cross section view of one embodiment of a pressure orienting swivel arrangement in a non-actuated position;
FIG. 2 is a cross section view of one embodiment of a pressure orienting swivel arrangement in an actuated position;
FIG. 3 is a perspective view of a weight assembly of the arrangement;
FIG. 4 is a perspective view of a gear ring of the arrangement;
FIG. 5 is a perspective view of a pin adaptor of the arrangement.
DETAILED DESCRIPTION
Referring to FIGS. 1 and 2 , a non-actuated position and an actuated position, respectively, of one embodiment of a Pressure Orienting Swivel arrangement 10 is illustrated. A comparison of the locations of various component of the arrangement in the two figures will provide an overview for the following description of the individual components and their interactions.
Referring to FIG. 1 , and beginning at an uphole end of the arrangement (left side of the figure as per convention) a top sub 12 can be seen. Top sub 12 is fixedly attached to a spring housing 14 at a threaded connection 16 . The top sub 12 includes an inside surface 18 that defines the outer most region of a fluid pathway 20 through which pressurization fluid is applied to the arrangement 10 when actuation thereof is desired. Further the top sub 12 includes a seal recess 22 receptive to a seal such as an o-ring (not specifically depicted due to scale, and not needed due to knowledge in the art). Slidably disposed within the inside surface 18 is a seal sleeve 24 .
The seal sleeve 24 is attached at a downhole end thereof to a spring compression mandrel 26 at an interconnection point 28 . The seal sleeve 24 provides a spring shoulder 30 upon which an uphole end 32 of a spring 34 bears during actuation of the arrangement 10 . A downhole end 36 of the spring 34 bears against a bushing 38 or other surface capable of supporting the spring 34 when under compression during actuation of the arrangement.
Adjacent the bushing 38 and through the spring housing 14 is one or more fluid displacement pathway(s) 40 (two shown) within each of which is a filter material 42 in one embodiment of the arrangement 10 . This provision allows for fluid to move into or out of the arrangement while the arrangement is being actuated or released from the actuated position to avoid the potential for hydraulic locking or inhibition of movement of the components of the arrangement 10 due to hydraulic forces created by fluid in the arrangement.
Downhole of the spring housing 14 and fixedly attached thereto is an extension sleeve 44 . The extension sleeve supports a pin 48 fitted to rotationally constrain a gear ring 72 . Within the extension sleeve 44 , a weight assembly 50 is supported on the spring compression mandrel 26 at bearing 46 and bearing 52 . Between the bearings 46 and 52 , the weight assembly is balanced axially to promote a relatively frictionless rotational movement within the arrangement 10 . This is a useful attribute for the arrangement because it facilitates the self-orientation of the weight assembly 50 . Orientation of the weight assembly 50 is important to the function of the arrangement 10 . Further the construction of the weight assembly 50 facilitates operation of the arrangement 10 . Referring to FIG. 3 , an enlarged view of the weight assembly 50 is provided for clarity of its construction. The weight assembly comprises a cage 53 , a weight 54 , a key 56 and an orientation torque producer 58 . It will be appreciated from the figure that the weight 54 extends, in this embodiment, about one half of the cage 53 . The purpose of the weight is to cause that the weight assembly 50 orient itself to gravity. In a horizontal or highly deviated well, this ensures that an operator can count on a correct orientation of at least one component in the wellbore. Because the orientation of the weight assembly 50 is known, a desired orientation of another component of the arrangement 10 can be set using the weight assembly 50 as the known. The weight assembly rotates itself only and therefore does not suffer from the drawbacks of prior art devices that have attempted to use an offset weight to orient target tools. Rather the weight assembly as disclosed herein has an overall mass that is substantially concentrated in the weight 54 and therefore only a very small percentage in the cage 53 and key 56 .
Importantly then the weight assembly also features an orientation torque producer 58 that functions to orient another component of the arrangement 10 to the weight assembly 50 . It is this function that allows an operator to set a desired orientation of this separate component. The component is a pin adapter 70 identified in FIGS. 1 , 2 and 5 . Because the weight assembly will find gravity and the pin adapter will orient to the weight assembly, a specifically positioned tool attached to the pin adapter 70 will have a known orientation when the arrangement is actuated.
Referring for a moment back to FIGS. 1 and 2 , further components of the arrangement 10 are identified to improve clarity of the discussion regarding the actuation of the arrangement. A gear ring 72 is positioned at a downhole end of extension sleeve 44 and is pinned in place rotationally by pin 48 . Reference to FIG. 4 makes clear the construction of gear ring 72 including a plurality of gear teeth 74 and lead in ramps 76 to help facilitate engagement therewith by the key 56 to prevent rotational movement of the weight assembly when that assembly is engaged with the gear ring 72 . Prevention of rotational movement of the weight assembly means that all of the torque production capability of the orientation torque producer 58 , in this embodiment a helical profile, is available to turn the pin adapter 70 . The pin adapter rotates within a pin adapter housing 78 which itself is joined to the extension sleeve 44 by a stop sleeve 80 . The pin adapter 70 , in this embodiment is supported within the housing 78 by a radial type bearing 82 and a thrust bearing 84 . A seal 86 is provided between the pin adapter 70 and the spring compression mandrel 26 to seal the arrangement and working with seal 22 for pressure based operation.
At a downhole end of the arrangement 10 ( FIGS. 1 , 2 and 5 ) is a pin adapter tail 88 that features an orientation indicator such as a groove 90 that will always be in a position opposed to gravity when the arrangement is actuated because of the interaction between pin adapter 70 and weight assembly 50 , which occurs at torque producer 58 of assembly 50 and a complementary profile 92 in this embodiment. The groove thus allows an operator to connect a tool at a specific desired orientation in the wellbore. One such tool is, as illustrated here, a perforation nozzle sub 94 having nozzle receptacles 96 . It will of course be understood that any tool could be attached to the pin adapter as desired or required for a particular application.
In operation, the arrangement 10 is assembled at surface with a tool 94 oriented to the groove 90 so that the tool will have the ultimate desired orientation in the wellbore when the arrangement reaches a target depth and achieves the actuated position. The arrangement is then run in the hole until it reaches the target location. Pressure supplied to the pathway 20 acts upon the arrangement to urge a number of its components in the downhole direction. These are the seal sleeve 24 , the spring compression mandrel 26 and the weight assembly 50 . The spring 34 is compressed by spring shoulder 30 of the seal sleeve 24 during this operation. Since gravity based orientation of the weight assembly 50 has already occurred, since it is continuous until engagement of the key 56 with the gear ring 72 , downhole movement of the weight assembly causes the engagement of the key 56 between a pair of teeth of the gear ring 72 . Since the gear ring itself is restricted in rotational movement by the pin 48 , the weight assembly will now also be prevented from moving rotationally. It is noted that a reduction in pressure on the arrangement 10 will allow the key 56 to disengage from the gear ring and thereby restore rotational movement to the weight assembly under action of the spring 34 but too, a repressurization will reengage the key 56 with the gear ring. This can be repeated as desired. Importantly, and as noted above, the gear ring maintaining the weight assembly rotationless means that upon further pressure based downhole movement of the weight assembly and engagement of the torque producer 58 with the pin adapter 70 , all of the torque generated is transferred to the pin adapter 70 . Torque on the order of about 70 ft lbs can be generated in one embodiment hereof upon the application of 5,000 psi.
While preferred embodiments have been shown and described, modifications and substitutions may be made thereto without departing from the spirit and scope of the invention. Accordingly, it is to be understood that the present invention has been described by way of illustrations and not limitation. | A pressure orienting swivel arrangement includes a freely rotatable weight assembly to orient to gravity prior to being urged to a fixed position. In the fixed position, a pin adapter is reactably interengagable with the weight assembly to orient the pin adapter to the weight assembly without reorienting the weight assembly from gravity. A method for orienting a downhole tool is also included. | 4 |
CROSS-REFERENCE TO A RELATED APPLICATION
[0001] This application claims the benefit of U.S. provisional patent application Ser. No. 61/891,674, filed on Oct. 16, 2013, entitled “HYDRAULIC BOREHOLE MINING SYSTEM AND METHOD,” the entire disclosure of which is incorporated herein by reference.
FIELD OF THE INVENTION
[0002] The present application relates to the field of subterranean hydraulic borehole mining. More specifically, the present invention relates to a new and novel high pressure system and method to perform economic, high production, continuous commercial mining by hydraulic borehole mining within a target ore body either in fully submerged conditions below the water table or at full atmospheric conditions.
BACKGROUND OF THE INVENTION
[0003] In situ hydraulic borehole mining equipment and techniques have been patented in the past for applications that include the mining of uranium, phosphate and heavy oil resource bodies, such as U.S. Pat. No. 4,915,452 issued to Dibble; U.S. Pat. No. 4,296,970 issued to Hodges; and U.S. Pat. No. 4,348,058 issued to Coakley et al. However, the mining systems and methods in these representative disclosures do not effectively address the fluid dynamics associated with maximizing effective jet horsepower, do not provide an economical alternative for mining in an isolated flooded environment, and do not effectively address the ability to efficiently lift the resource to the surface. These prior patents have defined equipment designed solely to lift ore back to the surface by the use of a high-pressure eduction system. Notwithstanding the advances made by these inventions, to date, no prior art hydraulic mining system has reached commercial success because of the ineffective utilization of fluids and the sub-optimization of production. Prior art systems do not fully integrate the critical components of hydraulic borehole mining to optimize reach and production rates on the one hand and minimize energy consumption on the other. Thus, continual economic commercial production rates have not been achieved, and the operating costs are too high to effectively replace conventional commercial mining systems and techniques.
[0004] Other problems associated with prior art mining systems are related to the mining pipe itself. The thread connections intermediate various sections of the mining pipe are prone to galling and eventually become unusable. With the externally flanged connections of the system invention, the problem of galling of threads is eliminated, inasmuch as the threads interconnecting the sections have been eliminated. In a threaded connection with multiple telescoping pipes, several sets of threads must be properly aligned in order to make up the mining string. Even with small misalignments, threads become galled, rendering a piece of mining pipe unusable. With the six string of the subject invention (five pipes down and one return), the pipe is aligned, put into place and assembled together with nuts and bolts, virtually eliminating any chance of damaging the mining pipe sections.
[0005] Another problem associated with prior art mining systems is the tendency to collect oversized particles in the bottom of the cavity. With prior art systems, when the system becomes blocked, advancement stops, requiring tripping out of the hole and drilling the rock fragments up by conventional methods, which severely affects operating economics.
[0006] Non-turbid lamination of the water flow to the jet is one component of the subject invention in terms of ultimate production and reach of the jet in the cavern in both atmospheric and submerged conditions.
[0007] Hydraulic borehole mining has several advantages over conventional mining techniques. One of the key attributes that is exploited through the borehole mining technique is the ability to selectively target and mine high grade resources. With hydraulic borehole mining, the highest-grade section of the resources can be selectively mined and the remaining lower grade resources are maintained in place. With traditional mining techniques, the overburden is removed or worked around in order to access the targeted resource. The usual expense and dilution of the economics of the project can render the project economically unfeasible. The use of the subject invention and associated techniques allows a small borehole to be drilled into the resource body, thereby permitting the target ore to be efficiently and economically mined and moved to surface.
[0008] The environmental impact of an underground hydraulic borehole mining process is exponentially less than that of a conventional open pit mining operation. Highly mobile equipment deployable at any angle on commercially available modern drilling rigs allows high accessibility to horizontal surface based, high slope and marine based operations. Small-scale equipment used in the process minimizes site impact and decreases mining risk of groundwater and surface contamination by cased isolation of the mining system and effective protection of groundwater. Leaching of resources such as uranium or contaminated fluids or acids such as those generated through oil sands or heavy minerals mining is minimized, if not completely eliminated. A unique aspect of the system herein disclosed is that, compared to prior art systems, it can operate both in a fully submerged state and in an atmospheric state. Operating in an atmospheric state extends the reach in certain geology by increasing net delivered horsepower.
[0009] In some cases, total elimination of open pit access allows safe access to the resource. The effective mining of the resource can allow stripping the target components within the ore, such as the ablation of U308 particles from sandstone or stripping target minerals from mineral sands and the corresponding reinjection of the waste tails in situ by blended sealing with cementitious grout. Effectively, remediation costs and requirements are significantly reduced, less overburden is moved, less in situ groundwater is affected, less surface impact is created and the carbon footprint of mining operations using the invention is greatly reduced compared to conventional mining operations or prior hydraulic borehole mining technology. Personnel head count can be reduced and exposure to high-risk ore such as uranium can be greatly reduced by effective and economic commercial hydraulic borehole mining. It is not necessary to expose personnel to radiation risk underground. Moreover, the invention provides closed loop fluid circulation limiting oxygenation of the resource. This reduces environmental exposure of radiation, salt water and acid onto the surface and in situ mining sector.
[0010] Within the United States and in other countries around the world a vast inventory of projects exist that have either reached the end of their known economic mining life, or that cannot be initiated into production due to unachievable economics or operational or technical inaccessibility. This invention with the complete modernization of new, conceptual and proven hydraulic engineering components will provide a new opportunity to reestablish prior mined resource areas, to create new jobs by economic resource creation and to enrich both private industry and government owned resource bases. Further, this invention will allow the establishment of a new realm of mining potential in environmentally sensitive areas which are not accessible currently because of destructive surface mining or risk of exposure to undesirable mining circumstances. Additionally, the mobility and accessibility of this invention allows the resource owner to target smaller reserves with more discerning accuracy of mining, thereby increasing established resource and reducing capital and regional impact.
[0011] Resource body types exist, such as metallurgical coal seams in steeply dipping planes along the environmentally sensitive slope of the Rockies, the steep hills of Appalachia, and the ultra-heavy oil reserves of west Texas and California that are not currently minable. The shale oil reserves on the Eastern Rockies slopes are sub-economic to conventional mining. The deep in situ uranium deposits in New Mexico, Colorado and Texas and the kaolin and phosphate deposits of the Southeastern states all have development, reserve and resource potential beneficial to private industry and government with the effective deployment of this system and apparatus. The Kimberlite reserves of Saskatchewan, Canada cannot be developed with conventional mining methods, yet exist as the largest Kimberlite reserves in the world. Kimberlite pipes which only allow fractional accessibility through conventional mining, Kimberlite and Lamprolite pipes in Australia and South Africa that have reached economic limit because dewatering costs are too high or the size of the pipes and the incline of the hanging walls are too steep for conventional mining, all may be accessed by the system and methods herein disclosed. The same may be said of millions of tons of other known resources that cannot be mined or declared as economic reserves because the ore is inaccessible due to high water tables and or excessively steep access ramps. This invention allows the resource owner to drill deep into pipes and target high-grade ores and minerals selectively and up to depths never achievable with conventional mining in certain conditions. Offshore granular resources such as tin mining can be enhanced with the invention where conventional dredges cannot access the resource through deep overburden. Technical accessibility with the invention proves a highly desirable effect on mining potential with low disturbance.
[0012] In the hydrocarbon resource sector, the system allows further development of oil shales, oil sands, oil rock and gas shales by cavity creation. Cavity creation allows significant opening of the natural fractures of the rock and may be used as a replacement to hydraulic fracturing or “fracking.” This advancement alone may have significant impact on the conventional oil industry in areas where fracking creates potential for disturbance or is completely banned.
[0013] The nature of the system allows the operator to excavate the oil in situ and transport the oil bearing rock to the surface. The subject invention will allow unique access to depleting fields that have significant quantities of oil not currently economically recoverable with known technology. The mining system of the present invention could be used in countries where fracking is completely banned and substitute shallow heavy oil deposits exist.
SUMMARY OF THE INVENTION
[0014] The subject invention provides an economic mining alternative to the energy consumption and fluid requirements of the prior art having sole eduction systems, and utilizes hydraulic airlift and/or eductor system technology to lift the resource to the surface through a vertical lift section of the system. The annular fluid of the system and an inner bore reverse circulation system differential allow an operator to inject a small amount of low pressure air into the return fluid column, thereby reducing its density and creating a vacuum at the system inlet to efficiently lift most resources to surface.
[0015] When compared to prior art stand-alone eductors, the airlift system of the subject invention can operate very efficiently with very limited energy. The reduced horsepower and diesel consumption during operation of the mining system of the present invention creates dramatic capital and operating cost savings.
[0016] The eduction system is an effective method to return the slurry to the surface. In some conditions such as with horizontal mining, eduction works in conjunction with the other components of the mining system. However, as a stand-alone method of lifting, the energy requirements are very high and require that a very high ratio of fluid and pressure be circulated to the bottom of the well bore to educt the disaggregated resource material back to the surface. The subject invention addresses this and other problems associated with prior art systems by being designed to work while jetting in atmospheric conditions or in submerged conditions. The eduction boost on the system is provided and allows access to long horizontal resource beds from the surface by providing a low pressure fluid eductor at the inlet of the miner to push the slurry coaxially through the horizontal section of the mining pipe into the vertical section of the well bore and for the hydraulic airlift at that point to boost the fluid the rest of the way to the surface through differential hydraulic pressure.
[0017] The pipe connections within the system herein disclosed address the galling problems noted above. The high-pressure fluid streams have no tolerance for leakage. The jetting connections operate at extremely high pressures (up to 10,000 psi), and the fluid must remain fully, safely and properly sealed for the entire length of the mining system. A pressure or fluid loss at a connection is intolerable due to the safety risk at high pressures and the need to control jet volumes and consistent delivery pressure at the outlet.
[0018] More particularly, the method of the subject invention involves economically mining subterranean resource in situ comprising the steps of drilling a surface hole into subsurface material to access the target resource, injecting high pressure fluid via a borehole mining tool into the resource thereby forming a jet to disaggregate the subsurface material creating a slurry of solids and fluid, injecting a gaseous fluid into the slurry to encapsulate and accelerate the high pressure fluid jet, injecting a large volume of water at low pressure into the slurry for eduction to mix with and transport the slurry, injecting low pressure air into an airlift sub to create suction whereby the slurry is lifted to the surface, separating solids and water at the surface; and optionally recycling the water for reuse in the method.
[0019] Further, the subject invention involves, a borehole mining system including at least one multi-conductor high pressure swivel for redirecting high pressure fluids of both air and water in a high pressure section through the system and to pass a generated slurry though the center bore, a low pressure swivel for redirecting the low pressure slurry at the surface, an air lift sub for assisting the return of the slurry to the surface, a lamination tool within the mining pipe for placing the high pressure water into laminar flow, a monitor pipe that maintains the laminar flow of the water from the monitor pipe to the single flow into the quartic-straight jet nozzle, an eductor system for mixing and returning the slurry to the surface, a plurality of internal flush connection subs joining the high pressure section, a turning section including a plurality of splitter vanes establishing and for maintaining the laminar flow of the water during a turn into a nozzle; and a fluid/air shrouding system.
[0020] The borehole mining system of the subject invention has a mining pipe with multiple passages, at least one of said passage being a high pressure section for redirecting a high pressure fluid water through the system; the high pressure section includes a first section with a pair of interior vanes positioned perpendicular to each other, and the interior vanes establish a laminar flow of the fluid within the first section. A second section is connected to the first section for receiving the laminar flow and turning the laminar flow to a different direction. The second section has a plurality of adjacent parallel passageways, each of the adjacent passageways conveying a different volume of said fluid, so that the laminar flow of said fluid is maintained in its flow through the second section. The passageway that is interior to its adjacent passageway will carries less volume of fluid because it is shorter and smaller, so that the flow of water through the turning section remains the same regardless of the passageway and thus maintains the laminar flow. The interior vanes that establish the laminar flow can establish a minimum of three or four passageways, and more, dependent on the size of the pipe. The interior vanes may be replaceable for better and longer life, as may be the blades of the turning section.
[0021] The subject invention operates at the torque and stress level required for drilling operations while mining. The system has a purpose-designed eductor drilling bit that educts right from the bit head itself. This attribute allows an operator to progress the well with the mining systems of the present invention compared to prior systems that had to be removed from the well. In addition, the subject system allows for the removal of material at the bottom of the well and not further up the drill string in the sidewall of the pipe as before. The inlet up the side wall of the pipeline does not allow the continuous mining of soft formation caving ores such as mineral sands because the prior art systems did not allow advancement while mining.
[0022] The subject invention aligns the two parallel high-pressure water supply lines from the pumps at surface. The water flow travels in parallel to a point in the mining pipe where it is introduced to four laminar flow chambers created by sectionalized vanes 9 meters long that align the fluid into laminar flow. The two laminar flow pipes connect to the mining head itself. A block co joins the fluids and maintains the laminar flow to the delivery section of the miner where the jet exits.
[0023] In order to turn the very high pressure flow 90 degrees to exit out of the jet to cut the sidewall and thus create the cavity mined, the system of the subject invention must maintain the alignment of the flow while in lamination in order to maximize the distance and the effectiveness of the jet. To do this, the subject invention utilizes a turning vane block that has inset replaceable turning vanes that turn the high-pressure high volume flow without creating turbidity or losing lamination. The subject borehole mining invention uses a set of replaceable turning vanes positioned prior to the chamber of the monitor jet. The current invention utilizes replaceable and serviceable blade sections that may be quickly and economically repaired for ongoing operations. When the blades become damaged over time by the passing of fluid over them, they may be removed by unbolting the housing and replacing them. Prior art designs often resulted in a pipe split which had to be welded back together or which was otherwise unserviceable and disposable. A set of removable turning splitter vanes further enhances the economics of the system, creates more overall efficiency and requires fewer replacement parts to maintain day-to-day operation of the equipment.
[0024] The hydraulic borehole mining process of the subject invention can be summarized as follows: a suitably sized hole is drilled to convey the borehole mining system to the top of the resources to be mined; that surface hole is then cased if necessary, and cemented as known in the art to provide stability and to protect groundwater and resource leaching; a hole is then drilled through the resource body; a mining pipe with multiple passages with a jet nozzle and a slurry recovery system is then lowered into the borehole. A high-pressure fluid pumping system is connected to the mining string and high pressure fluid is pumped down the string and out of the nozzle at the cutting face. The high-pressure fluid stream interacts with the rock face down hole disaggregating the rock and putting the particles into a slurried suspension; this slurry is then recovered through a piping system and returned to the surface, where the rock that is recovered will be processed and the mining fluid is returned to be pumped down hole again.
[0025] Another component of this invention is the ability to multi-task with up to six separate lines comprising the mining pipe. One line is the air/fluid shroud that can be utilized to protect the water jet. This shroud is a jet of high-pressure air or fluid (or a mixture of both) that is formed down hole to surround the high pressure water jet as it exits the nozzle. This shroud effectively provides an encasement and protection of the jet, whether cutting with fluids at atmosphere or submerged. In either case, the air and optional fluid increase the focus of the water jet and, hence, increases delivery jet horsepower on the target. Depending on the flow requirements, multiple lines can be used for jetting fluid, or, alternately, multiple jets could be used. In addition, air lift can be used in a line to use air lift for the primary method of slurry recovery or as a supplement to eduction. The mining pipe also has the ability to provide a return line for the slurry created while mining With a multiple line/passage mining pipe the operator has the option for a specific configuration for a specific application that can be changed if required, all while only requiring one mining pipe to be installed into a horizontal or vertical wellbore.
[0026] The mining system of the present invention mines hydraulically at significant depth at all angles from true vertical depth to a completely horizontal setting through a narrow diameter surface-drilled hole in both atmospheric and in submerged conditions. High pressure mining fluid is conveyed through the system to the cutting nozzle down the hole. This interaction between the mining fluid and the target rock face disaggregates and slurrifies it and it is returned to the surface via specific return elements in the system.
[0027] This invention can be utilized to economically and efficiently mine resources that sit from 0 to 90 degrees from the vertical. This hydraulic borehole mining system can be utilized in resource bodies that are submerged or that are dewatered. The system utilizes a fluid/air-shroud around the jet to increase the hydraulic horsepower to the rock face when the tool is utilized in a submerged or atmospheric environment. The entire process occurs in a closed loop system, from the high-pressure water delivery elements from the surface down the borehole to the return elements back up into the surface processing facilities. The surface annulus is sealed and connected to a pump that boosts the pressure on the annulus space, thereby aiding in the return of the slurry to the surface.
[0028] This system effectively utilizes principals of fluid engineering and differential dynamics both by maximizing effective hydraulic horsepower and fluid density properties by lamination of fluid flow through the mining system down the well bore and though a tight radius turn of the jet stream. A shroud of a high-pressure air or fluid stream (or a mixture of both) encircling the water jet stream protects the fluid jet generated by the laminated focused flow of mining fluid. The fluid jet shroud has proven effective to consolidate and protect the fluid stream and increase the effective jet horsepower both at atmosphere and under submerged conditions.
[0029] This mining system is designed to operate within the plane of the ore body that yields the greatest resource production at any angle from vertical to completely horizontal. The system is deployed either by directionally controlled drilling or vertically controlled stabilized drilling.
[0030] All of the elements of this mining system are designed to maximize fluid flow efficiency both down and up the wellbore. This fluid circulation with the air supported laminar hydraulic jet and the return to surface using differential pressure allows a significant reduction in equipment, energy and costs from any past versions of hydraulic borehole mining systems. Minimization of economics and reduction of the operating footprint and personnel prove to define commercial economics in multiple target ore types.
BRIEF DESCRIPTION OF THE DRAWINGS
[0031] FIG. 1 is a general schematic of a hydraulic borehole mining system in accordance with an embodiment;
[0032] FIG. 2 is a general overview of the hydraulic borehole mining string of the system of FIG. 1 ;
[0033] FIGS. 3( a )-( f ) are detailed drawings of the monitor subassembly for the hydraulic borehole mining string including a Y design laminar flow joint, turning vane block, nozzle holder and nozzle;
[0034] FIG. 4 is a drawing of the low pressure and high pressure combination swivel;
[0035] FIGS. 5( a ) and ( b ) are drawings of the flex joint insert for horizontal hydraulic borehole mining applications;
[0036] FIGS. 6( a ) and ( b ) are drawings of a section of mining pipe;
[0037] FIG. 7 is a drawing of a laminar flow insert mining pipe;
[0038] FIGS. 8( a )-( d ) are drawings of an airlift subassembly;
[0039] FIGS. 9( a )-( c ) are drawings of an internally flush high pressure connection assembly;
[0040] FIG. 10 is a drawing of a bit assembly;
[0041] FIG. 11 is a drawing of an eductor bit sub assembly; and
[0042] FIGS. 12( a ) and ( b ) show a drill rod assembly with connection subs.
DETAILED DESCRIPTION OF THE INVENTION
[0043] Referring now to FIG. 1 , a system and a process of hydraulic borehole mining for a subterranean resource in accordance with the present invention is described in detail. A rig shown generally at 1 is brought to the site, situated at a preferred location at the site, and operated to drill a well (or wellbore, as the term is used in the art) to the top of the resource body. The wellbore may be drilled at any angle from vertical to horizontal depending upon the geotechnical mining conditions down-hole and the structure of the ore body itself. A casing string 3 , if required, is then run into the initial bore and cemented into position to give strength to the wellbore. A conventional drill string is then fed into the casing string, and a pilot hole is drilled through the resource body. The conventional drilling string (not shown) is thereafter removed from the hole.
[0044] Referring now to FIGS. 2 and 6( a )-( b ), a mining string 5 is illustrated in greater detail. The mining string is run into the wellbore and includes an eductor bit 8 positioned at the bottom end 10 of the string and attached to a monitor pipe 12 , which houses the quartic-straight jet nozzle 15 ( FIGS. 3( e ) and ( f )), the turning vanes 18 ( FIG. 3( c )), and the integrated Y design laminar flow joint on monitor pipe 12 ( FIGS. 3( a ) and ( b )), all of which will be described in greater detail below. The monitor pipe 12 is connected to the mining string 5 that extends from the surface and the rig floor down to the subterranean resource deposit 21 ( FIG. 1) . The mining string includes swivels 22 , 24 ( FIG. 4 ). At swivel 22 , the connections are made from the mining string to the surface equipment at 120 . The swivels consist of a set of two swivels, one high pressure 24 and one low pressure 22 ; the interconnections of which provide all of the fluid connections needed for the process. The high pressure swivel, which sits on the bottom of the two swivels, takes the high pressure feeds of water for the quartic-straight jet nozzle, the air to the air lift system, fluid for the eductor, and the air or fluid to the air/fluid shroud, and sends them down the respective lines in the mining pipe to the attachments down the string. The low pressure swivel 22 that is attached above the high pressure swivel provides a passageway 130 or a return line for the slurry to return up the hole via the 90 degree turn into the return line, thereby directing the slurry to one or more surface processing facilities, generally shown at 26 in FIG. 1 . A unique and novel feature of the system of the present invention is the significantly enhanced ease of maintenance and efficiency of operation as compared to any prior art systems and methods. By way of example and not of limitation, maintenance of either the high or the low pressure side of the system will not involve replacing parts or tearing down the other side, and vice versa.
[0045] As best shown in FIG. 1 , the configuration of the surface portion of the mining system is illustrated. The surface equipment includes two high-pressure, high-volume jet mining pumps (not shown), which deliver water down hole via the swivel and high pressure lines 32 . An air compressor delivers air to the swivel via high and low pressure lines 36 to be delivered down hole to an air/fluid shroud 38 around a quartic-straight jet nozzle 15 and the airlift sub 100 shown in FIG. 8 , both of which are shown in FIG. 3 . When conditions dictate, the high pressure airline that forms the air shroud can be connected instead to a pump that supplies fluids of different densities to the shroud nozzle to aid in the hydraulic horsepower of the tool. Referring back to FIG. 1 , a lower pressure water pump delivers water to the eductor bit 8 and to the backside of the well head via low-pressure water line 44 to keep the surface hole full of water. The supply of low pressure water to the backside optionally may be forced in past a seal, introducing an additional amount of pressure and force to the backside of the pipe. This additional force above the weight of the column of water on the backside gives a boost to the recovery system by essentially forcing fluid under pressure up the mining string's lower density return line and thereafter to surface.
[0046] As shown in FIG. 1 , the return line runs from the swivel to a dewatering system via a low-pressure slurry return line 50 . This portion of the system removes the water from the resource and returns the water to a dirty water storage pond or tank. A storage facility 56 is used to store the dewatered resource while awaiting further processing by the mine. The water from the dewatering system then flows to a settling pond where any fines that have collected into the water are permitted to settle before flowing into a clean water storage area. The clean water storage area holds the clean water, which feeds all of the pumps.
[0047] The clean water is boosted into the high pressure pumps and then pressurized and pumped into the high pressure mining swivel 24 ( FIG. 2 , 4 ), where it is turned 90 degrees and down the mining string 5 through two external lines 62 , 64 on the mining pipe, as best shown in FIG. 6 . Each pump feeds one of the lines via high-pressure lines 32 . These lines are connected to the swivel 24 at flanges 66 with full bore fittings and then run the length of the pipe via stabilizers.
[0048] Referring to FIGS. 9( a )-( d ) and FIGS. 12( a )-( b ), the mining pipe connections utilize full flow connection subs 70 at each of the quint external lines which provides a high pressure seal between the mining pipe sections that make up string 5 via special high pressure, expandable O-rings 72 seated in grooves 74 formed in the sub 70 ( FIGS. 9( b ) and 9 ( c ). Each of the subs includes an external diameter d ( FIG. 9( b )) which fits inside a corresponding mating flange (not shown) on the mining pipe. This novel configuration allows for the full inside diameter (internally flush) of the external lines of the mining pipe to be maintained in the connection sub. The connection subs are utilized in the connection of the individual segments of the entire mining pipe ( FIG. 2) , the connection of the airlift sub ( FIGS. 8( c ) and ( d )) and the connection of the monitor pipe 12 ( FIGS. 3( a ) and ( b )). Due to the internally flush-full bore, restriction-free structure of the subs, there is less of a pressure drop in the high pressure lines at the connections, an advantage which manifests itself over a large number of connections in a string, where the pressure drop over the overall distance would be significant.
[0049] The last 9 meters of the mining pipe in the string contain a pair of laminar flow vanes 80 positioned perpendicular to one another and which are illustrated in greater detail in FIG. 7 . Each pipe includes two laminar sections 82 which are structured and arranged to preliminarily align the otherwise turbid flow of the water into a laminar flow stream configuration, thereby providing increased hydraulic horsepower to the jet stream. The laminar flow is established utilizing the four sections to split and align the flow. The vanes 80 are formed of a suitable material such as steel and are positioned securely in the high pressure water lines of the mining pipe as shown in FIG. 7 , the vanes being sealed in place by means of a high pressure o ring seal 84 in a housing 86 positioned inside of the lines. This o ring seal is extremely tight and fixes the units to minimize resonance within the pipe. The vanes 80 are designed for easy and quick replacement by withdrawal of the worn vanes and insertion of new vanes into slots 81 .
[0050] Referring to FIGS. 3( a ) and ( b ), the high pressure water lines feed the laminar water flow to the monitor pipe 12 where they are joined to a laminar flow block 88 ( FIG. 3( a ), which ensures that laminar flow is maintained while the water is joined and then forced through the turning vanes 18 ( FIGS. 3( c ) and ( d ) which split the flow and maintain it in a laminar stream around the bend without introducing turbidity. These vanes are spaced out unevenly at predetermined spacing distances based on the flow around the 90 degree turn into the quartic-straight jet nozzle 15 ( FIGS. 3( a ) and ( f ). The variation in the distances between the vanes is a function of the speed, drag and flow of the water around the bend. Thus the interior passageway 16 allows less volume of water to pass, being smaller in size than the exterior passageway 17 , which is larger. As the passageways progress from interior of the block side to the exterior, they become successively larger in volume and carry more water, thereby equalizing the flow of water through the block. Each passageway is thereby larger than the adjacent passageway as one goes from the interior of the block turn to the exterior. In this manner the laminar flow of water in each passageway through the laminar flow block 88 is maintained by allowing the same amount of water through the block throughout the ninety degree turn, thereby reducing or eliminating turbulence in the flow at the block exit. As a result, more water at a higher velocity can be provided through the system because of the continuation of the laminar flow. The turning vanes 18 are designed to work with the anticipated cutting fluid and the total anticipated volume of flow through the jet.
[0051] The turning splitter vanes are connected to the quartic-straight jet nozzle 15 by bolts. The quartic-straight jet nozzle delivers the laminar flow into a focused jet through the nozzle orifice 90 delivering a high pressure, high volume stream of fluid at supersonic velocity into the rock face. An air/fluid shroud surrounds the water jet exiting the quartic-straight jet nozzle. This air/fluid shroud is created by high pressure air or a high-pressure fluid delivered from the surface ( FIG. 1 ) through the high-pressure swivel 24 , via an external line on the mining pipe 5 , through the monitor pipe 12 and into the shroud. The air/fluid is then delivered into the air/fluid shroud that focuses the air/fluid in a large diameter nozzle that encircles the high pressure quartic-straight jet with nozzle orifice 90 . The air/fluid shroud effectively surrounds the high pressure jet and increases the distance over which the jet stays consolidated for both underwater and standard atmospheric operating environments. The shroud flow laminates and binds to the jet flow and helps to accelerate the jet flow at atmosphere. While submerged, it lowers the density of the water along the jet flow alignment, effectively increasing the hydraulic horsepower that will be acting on the ore face in both environments. A unique aspect of this feature is that it allows the system to be operated at either increased jet pressure (thus taking less time to disaggregate the rock) or, alternatively, at a lower pressure (consuming less energy) to have effectively the same force from the water jet at the rock face.
[0052] As the water jet impacts the rock face it begins to disaggregate the material. The disaggregated material mixes with the water creating a slurry stream which is then carried to the eductor bit 8 as shown in FIG. 2 . The eductor bit pushes the slurry stream up a center return pipe 92 whereupon it is accelerated by the vacuum created in the mining return pipe by the combination of an airlift system or sub, as it is known in the art, 100 (illustrated in greater detail in FIG. 8( b ) and the pressure applied to the outside of the mining string 5 . This vacuum is created in two unique ways. First, the airlift system 100 charged by air from the compressor 34 is carried through the mining pipe via an external line 102 to the airlift sub where it terminates at the airlift housing 104 . The air then escapes through even perforations in the ring within the airlift housing into the slurry return line 92 via the airlift entry ports (not shown). The tiny bubbles that are introduced at depth expand as they move up the slurry return line. The bubble expansion lowers the density in the slurry return line which causes a u-tube effect on the outside of the mining string, and fluid moves through an eductor bit opening 108 and into the mining pipe slurry return line. This suction recovers the slurry created by the quartic-straight jet nozzle 15 and the disaggregated ore.
[0053] The airlift system 100 is typically placed at depth in a vertical well at a level to maximize the lift of slurry. This is adjusted according to the type of resource. For instance, when mining Kimberlites, the depth of the airlift sub in the well is controlled closely to keep velocities of the resource lower to limit diamond breakage. For mining uranium, on the other hand, an example of ore where grain size after cutting is not monitored, the airlift housing is placed lower in the well to increase the tonnage/mining rate per hour. On horizontal wells the airlift release is generally within the vertical section of the well for lift, and the eductor pushes the cut ore through the horizontal section. Critical velocities are matched to each ore type and the direction of the well to ensure the slurry is maintained in suspension without erosion of the system. The airlift system is a significant improvement over previous systems that only incorporate a fluid eductor for the recovery of the slurry, inasmuch as the airlift system reduces the total amount of horsepower that is needed on location to drive the system. It is through this reduction of horsepower that a significant reduction of overall capital costs is attained, not only by eliminating an additional pump, but also by reducing the overall cost of the operating expenses as a result of the lower horsepower demands.
[0054] The second part of the slurry return system is the eductor bit 8 discussed above with reference to FIG. 2 . The eductor bit is operated with relatively low pressure and with a high volume stream of water. This water is delivered through one of the external lines 112 on the mining pipe 5 . This water is delivered to a sub assembly 110 ( FIG. 11 ), turned 180 degrees via conduit or line 112 and directed back up the inner bore of slurry return line 92 of the mining string 5 , which causes a suction that draws in slurry and forces it up the hole.
[0055] As shown in FIG. 11 , the slurry passes through the narrower gauge of the eductor housing while being simultaneously boosted through that section of the eductor with the clean water from the surface via external line 112 . The acceleration of the fluids through the narrow section and then up the slightly larger inner bore of slurry return line 92 of the mining pipe causes a vortex and, effectively, a vacuum on the down hole side of the eductor. The two fluid streams converging in the narrow body of the eductor accelerate and then are released into the larger return pipe diameter. The differential pressure does not allow the fluid out the bottom of the bit so it accelerates the flow up the well bore continuously. The slurry is then carried up the hole, through the high-pressure swivel 24 and through and out of the upper low-pressure return swivel 22 , where it is sent to the surface dewatering facility 26 via a slurry return pipe 50 , as shown in FIG. 1 . A bit assembly 120 ( FIG. 10 ) can be utilized, where the slurry passes a plurality of replaceable cone teeth 122 into the slurry return line and thereafter into the mining pipe return line, as hereinabove described. This offers no additional boost to the system but helps grind slurry when required.
[0056] Each resource type dictates the specific mining strategy utilized. The formation of the mined cavity can be by drilling a pilot ahead and through the resource body and starting at the bottom of the hole and mining up or back towards the rig in the case of a horizontal well, or starting at the top of resource body and utilizing the eductor bit of the present invention to drill and mine at the same time from the top down. The competency of the formation of the target resource and the geotechnical parameters surrounding it dictates the mining approach and strategy. In either direction, the cavity is developed through the disaggregation action of the hydraulic jet and the rotation of the mining string. The string is rotated at a slow rotational speed, the speed of rotation being determined by the competency of the formation and the distance or length of the cut at any given point within the resource body. The jet is rotated sufficiently slowly to allow enough effective interaction between the hydraulic jet and the rock face to perform the disaggregation and the slurrification of the resource. The rotational speed is determined by the amount of material that is returned and sent through the dewatering facilities. The time on the ore face coupled with the combination of flow and pressure is adjusted to maximize production. As the mining string is slowly rotated, a larger and larger cavity is created. This cavity in a vertical application can be a full 360 degree circle or pillars can be left in place to support the surrounding resource as the cavity is cut. As the returns diminish, the tool string is moved vertically and another rotational pass is made. This basic technique is continued until the desired cavity is cut from the targeted zone. Several times during the process, the mining string can be dropped to the bottom and the suction system can be used to remove any slurrified material that passed the mining string and fell to the bottom of the hole. Dependent on the resource being cut, an initial pass can be made without the shroud. Then, a second pass over the ore face can be made with the fluid/air shroud. The shroud system increases the effective hydraulic horsepower at the ore face, which increases the cutting distance of the tool. The entire cutting process is repeated with the shroud on to enlarge the cavity. Upon completion of the cavity mining the entire mining string is removed from the borehole.
[0057] When the hydraulic borehole mining is performed in a high angle or horizontal application, the technique used to create the cavity can be different than that of the vertical application. In a horizontal application, the system of the instant invention is ideally drilled and directed to the bottom of the targeted resource. A pilot hole will be drilled from surface to the bottom of the targeted resource body and then horizontally out as far as reasonably possible into the formation, based on the characteristics of the formation material. The hole will be drilled out as far as possible without collapsing on top of the tool string. The drilling string will be removed and replaced with the mining string of the present invention. The mining system will be run out in the lateral direction to the end of the hole. Thereafter, the jet will be turned on. In the horizontal application, the monitor pipe will be rotated no more than 180 degrees. Since the tool is on the bottom of the resource zone, the targeted areas will be to the side and the top of the monitor pipe. In thicker resource zones, one lateral well can be mined above the other. If the competency of the resource body is low then the monitor pipe can be manipulated to perform 60-degree sweeps to either side of the tool, thereby making a bowtie pattern in the resource body. The advantage to this pattern in a low competency formation is that it permits recovery of the resource on the sides, which is facilitated by the natural subsidence of the formation over the mining string. As a section of the cavity is excavated, the mining string is slowly extracted, making the cavity larger and longer as the tool is retracted into the surface casing string. Upon completion of the cavity the mining system is removed from the hole.
[0058] Although the present invention has been described with reference to a particular embodiment thereof, it will be understood by those skilled in the art that modifications may be made without departing from the scope of the invention. Accordingly, all modifications and equivalents which are properly within the scope of the appended claims are included in the present invention. | A hydraulic borehole mining system controlled and operated above-ground includes a high-pressure cutting nozzle that is delivered to an underground resource body through a relatively small diameter borehole. A series of water and air fluid streams at various pressures are delivered to the resource body, and the target resource is disaggregated and/or fluidized and conveyed back to surface via the hydraulic borehole mining pipe which serves as the conveyor of the system. The mining pipe is used to transport a high-pressure stream of combined air and water fluids that have been directed and aligned into laminar flow to a focused water jet cutting head. The central bore of the mining pipe brings the slurrified resource to the surface. The mining pipe transports the slurry via hydraulic airlift, fluid eduction or both. | 4 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to the field of color inks and paints used in the printing, signage, fine and decorative arts industries.
2. Description of Related Art
David Makow in Color, Vol. 11, No. 3, p. 205 (1986) has shown that cholesteric liquid crystals (CLC), and in particular, the CLC polymers (U.S. Pat. No. 4,410,570), possess color properties and effects that are not possible to obtain by conventional dyes and pigments, including: additive color properties; higher saturation and wider color gamut. However, in their present forms, liquid crystal coatings cannot be used as general purpose color inks and paints for the printing, signage, fine and decorative arts industries. CLC's in the liquid phase are not possible to use unless they are somehow encapsulated. The CLC polymer coatings, on the other hand, are solid at room temperature, and as Makow showed, produce remarkable color effects and are highly stable. These CLC polymers are still inconvenient for general purpose applications because they have to be applied at high temperatures. The polysiloxane-based CLC polymers are applied at 140° C. in the liquid crystal phase and its molecules must be aligned to form the helical configuration with the helix axis perpendicular to the substrate (paper or canvas). This constrains the use of CLC polymers only in special applications and only by specialists.
This invention shows that by making CLC polymers into flat flakes or platelets having the helical axis normal to the platelets surface and mixing them in a suitable fluid, the prior art problems are solved, making it possible for CLC polymers to be conveniently used for general purpose applications exploiting their remarkable color properties. This is a CLC ink which is applied at room temperature, and no further alignment by the user is needed, since the platelets are already in the proper helical configuration.
SUMMARY OF THE INVENTION
The principal object of the present invention is to provide a method for producing CLC flat flakes or platelets.
Another object of this invention is to make novel CLC color inks which can be applied at room temperature and after drying, retain their remarkable color effects.
Another object of this invention is to provide a method for making CLC color inks using notch filter platelets which result in 100% reflection of ambient light producing the brightest and most saturated colors.
Another object of this invention is to provide low cost polarizers and polarizing filters.
Another object of this invention is to to provide a broadband circular polarizer based on CLC materials.
Another object of this invention is to provide a new method for making micro-polarizer arrays needed for 3-D stereo displays.
Yet another object of this invention is to provide novel color CLC pens, pencils, and crayons for painting and printing applications.
These and other objects will become apparent when the preferred embodiments are described.
BRIEF DESCRIPTION OF THE DRAWINGS
FIGS. 1a-1e is an illustration of cholesteric liquid crystal polymer platelets which are used in the novel ink.
FIG. 2a-2e illustrates cross sections of individual platelets of the simple kind and the notch filter kind.
FIGS. 3a-c illustrate three methods for manufacturing CLC platelets and inks.
FIG. 4a-4b illustrates methods of laminating CLC layers and retarder layer for producing notch filter CLC platelets.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Cholesteric Liquid Crystal Inks
The present invention depends on the well known properties of chiral liquid crystals, CLC, (also called cholesteric liquid crystals) described in the following references: S. D. Jacobs et. al., Journal of the Optical Society of America, B, Vol. 5(9), pp 1962-1978 (September 1988); ii)- Martin Schadt and Jurg Funfschilling, Society of Information Displays, SID 90 DIGEST, p 324 (1990); and iii)- Robert Maurer, et. al., Society of Information Displays, SID 90 DIGEST, p 110 (1990). These liquid crystals spontaneously order themselves in an optically active structure of a left handed (LH) helix or a right handed (RH) helix with a helix pitch P, and an optical axis which coincides with the helix axis. FIG. 1a shows an RH, CLC film 1 (cross section) prepared with its optical axis 2 perpendicular to the film. It exhibits the property of selective reflection when a monochromatic beam 3 of wavelength λ, propagating along the helix axis satisfies the relationship
λ=λ.sub.0 =n.sub.a P, (1)
where n a is the average refractive index of the CLC material and P is its pitch. Unpolarized light 3 with wavelength λ=λ 0 incident on the film will interact with the helix structure and causes the reflection of 50% of its intensity as right circularly polarized light 3a (RCP), and the other 50% is transmitted as left circularly polarized light 3b (LCP). On the other hand, if the incident light 4 has one or more wavelengths that are not equal to λ 0 , all the light is transmitted. We remark that equation (1) is strictly valid in the case where the angle of incidence θ (measured from the helix axis) is zero. For a non-zero value of θ, the effective value of λ o shifts to a shorter wavelength λ.sub.θ given by
λ.sub.θ =λ.sub.θ [cos {sin -1 (sin θ/n.sub.a)}] (1a)
In all subsequent discussions in this application, whenever θ≠0 it is implied that λ o means λ.sub.θ as given by Eq. (1a). If the film had an LH helix, FIG. 1b, and the incident unpolarized light 6 satisfies λ=λ o , 50% of the selectively reflected polarized light 6a would have the LCP state, and the other 50% transmitted part 6b would have the RCP state. The selective reflection wavelengths according to Eq. 1 is tuned by tuning the pitch length which is a material property that is varied by varying the chiral concentration or the concentration of the mesogenic side-groups (U.S. Pat. No. 4,410,570). Thus the CLC materials are prepared to produce the three additive primary colors; red, green, and blue. It is important to note that this selective reflection polarizing property does not involve or depend on an absorptive mechanism as in the case of conventional color pigments, dyes and sheet polarizers.
A fundamental property of light is that it can have only two independent, mutually orthogonal polarization states, either circular, LCP and RCP states, or linear states. Other polarization properties of light used in this invention are shown in FIGS. 1c-1e. FIG. 1c shows that an LCP light 8 incident on a metallic reflector 9 is converted into an RCP light 10 because the metal causes a phase shift of 180° between the independent electric field vector components. A quarter-wave retarder 11, FIG. 1d, causes a 90° phase shift and converts a circular light 12 into linear 13, and a linear light 14 into circular 15. In FIG. 4e, a half-wave retarder 16 converts RCP light 17 into LCP light 18 and vice versa by causing a phase shift between the independent electric field vector components.
The present invention relies on CLC materials in the solid state at the operating temperature. Such CLC polymers have been synthesized in the LH and RH formulations (See M. L. Tsai et al, Appl. Phys. Lett., 54, 2395 (1989)). These polymers are brittle. I have exploited this brittleness property in an experiment to prove that I can make small flakes or platelets which when applied (easily transferred) to a different substrate, retained their selective reflection property, i. e, the platelets remained aligned in the helical configuration with the helix axis normal to the platelet surface. FIG. 2a illustrates typical CLC flakes or platelets shapes 20. They can have regular or irregular geometrical shapes, with the average lateral dimension typically more than 3 times the thickness. Platelets 20 could have average lateral dimensions are in the 4 to 100 microns range (8 to 200 helix pitches), and average thicknesses of 4 to 20 helix pitches. FOGS. 2b and 2c show simple CLC platelets 20a, 20b, respectively, which have either LH CLC (20 a) or RH CLC (20b) helices. These simple platelets while they yield acceptable brightness and color saturation for many printing applications, they still waste 50% of the selected color energy. The notch filter platelets shown in FIGS. 2d and 2e are preferred because they reflect 100% of the light, thereby increasing the brightness by a factor of 2. This can be understood by referring to the CLC and polarization of light properties described above and in FIG. 1. In FIG. 2d, a platelet 21 for a particular color band (e.g. red) consists of two CLC layers, an LH layer 21a and an RH layer 21b. A red beam incident on platelet 21 is totally reflected. 50% of the light is reflected by the LH layer 21a as an LCP light, and the remaining 50% is transmitted through the LH layer 21a as an RCP beam. Said transmitted RCP beam is subsequently reflected by the RH layer 21b and is then transmited again through layer 21a to the observer. Thus, all the incident light is reflected. The same result is achieved if the RH layer 21b is replaced with a half-wave retarder layer 21c and a second LH layer 21d as shown in FIG. 2e. In this case, the RCP light transmitted through layer 21a is converted to LCP light by the retarder 21c which in turn is reflected by the second LH layer 21d. The reflected LCP is transmitted again (in the reverse direction) through retarder 21d and is converted back to RCP light that is transmitted again (in the reverse direction) through the first LH layer 21a, completing the 100% reflection of the incident red beam. The same happens for the other colors by means of appropriately tuned platelets. These platelets of the simple 20 and notch filter 21 types are mixed in a suitable fluid producing a CLC ink which is then used in printing, drawing, painting and other imaging applications. These CLC inks are applied at room temperature and do not need alignment by the user, solving prior art problems encountered in the Makow Reference. Conventional pigments and dye inks filter colors by an absorption mechanism and are applied to white background, such as paper substrates. The CLC inks, on the other hand, are reflective (see properties described above, FIG. 1) and are applied to black background such as black paper. The CLC inks are applied to the black substrate such that the platelets lie parallel to the substrate surface, and the CLC helical axes are normal to said substrate surface. Exploiting the remarkable additive and color saturation properties, red, green and blue CLC inks are sufficient to generate all colors. These CLC color inks are mixed before application to the substrate or they are mixed sequentially as they are applied in turn onto the substrate. To my knowledge, no prior art has taught how to produce CLC inks, applied at room temperature (or operating temperature), that reflect 100% of the incident color, and without the need for alignment.
The CLC ink according to this invention comprises the pre-aligned CLC flakes or platelets and a suitable fluid. Said fluid is well known in the ink art (see Chapter 18, p 523 in J. Michael Adams, Printing Technology, 3rd Ed., Delmar Publishers, Inc., Albany, N.Y., 1988) and is selected depending on the applications. It further comprises vehicles and additives chosen for tackiness, drying speed, adhesion to substrates, printing or painting methods, and other properties.
Manufacturing Method
FIGS. 3a-c describe methods and apparatuses used for high throughput economical manufacturing of CLC platelets. Apparatus 22 in FIG. 3a comprises a first belt 32 rotated continuously by means of rotating drums 24, 25, and a second belt 34 rotated by drums 36, 37 in the opposite direction of first belt 32. The first belt 32 carries the aligned coating of a CLC, while the second belt 34 is allowed to press against the first belt in order to remove the CLC coating by adhesive means. This process of coating and removal of aligned CLC layers and the production of the final product, the platelets or flakes are carried out continuously according to the following steps:
1. The starting CLC polymer material in a molten state in a container 26 is coated onto belt 23 by means of a roller 27 (other coating means such as spraying and casting are possible).
2. While the coated belt is in motion, a knife edge means 28 is used to smooth the CLC film, maintains a uniform and repeatable thickness, and aligns the CLC molecules such that the helix axis is perpendicular to the belt surface. The alignment step is a crucial element for practicing this invention. The excess CLC material 29 is recycled.
3. The pre-aligned CLC film then passes through an auxiliary alignment means 30 (if necessary) which applies electric or magnetic fields in the proper orientation to ensure that the entire film is aligned in the helical form.
4. Above steps are carried out above the glass temperature and below the clearing temperature of the CLC polymer. For polysiloxane-based CLC polymers, this coating and aligning temperature (processing temperature)is between 120° C. and 150° C. Other CLC polymers may require different processing temperatures.
5. The aligned CLC film then passes through a drying and cooling chamber 31 and the desired pre-aligned CLC film 32 below the glass temperature is brittle and can be transferred adhesively by the second belt 34.
6. The second belt 34, rotating in the opposite direction of first belt, is coated by means of a roller 38 (spraying or other well-known means may be used) with an adhesive. Said adhesive passes through chamber 39 for drying and maintaining an optimum operating temperature, and other adhesive properties. The adhesive could be water soluble polyvinyl alcohol or other adhesives which can be dissolved in suitable low cost solvents that have minimum environmental impact. Some adhesive may be chosen to be brittle when dry.
7. The optimized adhesive coating 40 is pressed by means of drum 37 onto CLC film 32 on drum 25. This action transfers the CLC film from belt 23 to belt 34. Drums 25 and 37 have a rubber surface that ensures optimum transfer of CLC to the adhesive. My experiments indicated that the polysiloxane CLC polymer transfers in the form of small platelets or flakes.
8. The transferred CLC on the adhesive is passed through a cooler 37a which cools the combined coating to low enough temperature to ensure the brittleness of both CLC coating and the adhesive coating. While polysiloxane based CLC polymer is naturally brittle at room temperature, other CLC polymers may not be brittle enough for the subsequent step. By cooling to cryogenic temperature such as that of liquid carbon dioxide or liquid nitrogen, it is well known that polymers (CLC's and adhesives ) become brittle.
9. The brittle CLC and adhesive are removed by means of an ultrasonic air jet 41 or an air jet mixed with fine powder abrasive. The CLC on adhesive that is not removed by the ultrasonic means is scrubbed off by means of a scrubber 42. The flakes of CLC on adhesive are collected in a container 43 and are poured into container 44.
10. The CLC on adhesive mixture is further broken into the desired average flake or platelet size. The adhesive is subsequently dissolved off and separated from the CLC flakes -which are dried and mixed with the appropriate fluid to produce CLC ink.
11. The process steps 1-10 for producing aligned CLC flakes are repeated continuously as belts 23 and 34 continue to counter rotate.
FIG. 3b shows another embodiment 45 for producing aligned CLC flakes that uses only a single belt. The embrittled aligned CLC film passes through an ultrasonic bath 46 which imparts intense ultrasonic energy to the CLC film causing it to flake-off.
Yet another embodiment 47 for producing aligned CLC platelets and simultaneously produce the final CLC ink (with minimum steps) is shown in FIG. 3c, comprising: a belt 23; two drums 24,25; a means 48 for coating, and aligning CLC films; and a means for transferring said films. The transfer means further comprises one or more transfer belts 49,49a,49b, coated respectively with adhesives by means of rollers 50,50a,50b. The rollers 50,50a,50b coat each of their respective belts with a random adhesive pattern. These patterns are designed to transfer CLC flakes with a predetermined average size. The belts 49,49a,49b are immersed in solvent container 51 which dissolves off the adhesive and precipitates the flakes with a predetermined average size that are ready for use in inks. In this case the solvent may be the appropriate fluid needed for the final CLC ink product.
The coating and alignment means 27,28,30,31,48 used above for the simple aligned CLC flake 20 in FIGS. 2b, 2c can also be used to produce the notch filter flakes 21 in FIGS. 2d,2e by placing in the proper sequence a plurality said coating, aligning, and drying means. Alternatively, FIG. 4a shows an embodiment which laminates pre-aligned LH CLC film 53 on a substrate (dispensed from a roll 53a) with a pre-aligned RH CLC film (dispensed from a roll 54a) using the counter rotating laminating rollers 55,56 and the final notch filter laminate 57 is taken up by roller 57a. The LH and RH laminate 57 is then broken into proper sized flakes for use in CLC ink product. In FIG. 4b, another notch filter laminate 63 is produced from laminating pre-aligned LH CLC films 58,60 with a half-wave retarder film 59, said retarder film being interposed between said CLC films.
Many skilled in the art will be able to find other variations of producing aligned CLC inks without departing significantly from the basic teachings of this invention. For instance, if the pre-aligned CLC film is not brittle, it is still possible to use it for producing platelets by well known patterning and etching means. In this case photo-resist or etch resist patterns are generated which serve to protect the desired platelets regions, and the exposed regions are etched away by a suitable wet or dry etching means. This would produce the desired platelet size and shape.
Applications Of CLC Inks
The aligned CLC inks produced based on the teachings of this invention can be used in the printing, signage, fine and decorative arts industries. Unlike prior art, these inks can be dispensed by well known means at room temperature and without the need for further alignment of the CLC molecules into the desired helical form. In the CLC ink, the aligned CLC flakes are suspended in a host fluid or a host matrix depend on the printing or imaging application. In a crayon or a pencil form, the host matrix could be a wax or an equivalent sticky material that is solid state at room temperature. This is used by the painter by rubbing off onto a black paper, the CLC flakes of the appropriate color and the host matrix. The host fluid could be dispensed from a pen for drawing, paining, plotting, and writing. The ink could be applied by means of a brush, roller, or spray gun. The ink could also be formulated for use in off-set printing wherein the host fluid is made hydrophobic, or in gravure and flexographic printing wherein the host fluid is formulated for printing on plastic substrates, or other substrates. The CLC ink may also be used as a toner in electrographic copier and printers (based on xerography process), thermal color printers as well as inkjet printers. According to this invention, color images are produced which feature colors more saturated and brightness high than can be produced by conventional pigment and dye based inks. The new method for producing reflective color images generally comprises: aligned CLC color inks having at least the three additive primary colors red, green and blue; an ink dispensing tool which applies the CLC ink at ambient temperature; an image source which drives the ink dispensing tool; and a black substrate (paper, canvas, plastic sheet). Color images of the transmission kind can be produced by applying the CLC color inks to a transparent substrate such as glass, polycarbonate sheets, acrylic sheets, and other plastics. In both the reflective and transmissive images, the notch filter CLC 21 produce the brightest and highest saturation images.
Aligned CLC inks can be used in other applications such as the production of :
1. Polarizing color filters and filter arrays for displays and other imaging applications, by simply printing the appropriate pattern with CLC inks.
2. Broad band polarizers and micropolarizer arrays can also be printed for use in 3-D stereo imaging, 3-D displays, 3-D printing, and 3-D cameras.
3. Variable transmission windows. | In color printing, and in the fine arts, cholesteric liquid crystal (CLC) color inks are known to possess much higher color saturation and brightness than conventional pigment and dyed based inks. However, prior art CLC ink formulations are inconvenient because in the liquid phase they have to be confined in cells, and in the solid phase, they have to be applied at high temperature, and have to be aligned by some means to produce the optimum color. This invention solves the problem encountered in the CLC prior art, by making pre-aligned CLC platelets or flakes of appropriate thickness and size and mixing them in appropriate host fluids producing a novel CLC ink which can be applied at room temperature and without the need for alignment. The new pre-aligned room temperature CLC ink can be used as a substitute for conventional inks in almost all printing and plotting, and manual drawing and painting. Using the notch filter CLC platelets, the brightness is further enhanced. This invention teaches the CLC ink concepts, its applications and method of manufacturing. | 2 |
TECHNICAL FIELD
[0001] The present invention relates to a phosphor element including a phosphor inorganic material and a display device using the phosphor element.
BACKGROUND ART
[0002] There is a display device using an electro luminescent (hereinafter referred to as EL) element, as a display device in a flat panel display which has been focused on together with a liquid crystal panel, a plasma display and the like. The EL element includes an inorganic EL element using an inorganic compound as a light emitter and an organic EL element using an organic compound as the light emitter. The EL element has high-speed response, high contrast, vibration resistance and the like. Since the EL element has no gas in itself, it can be used under high or low pressure.
[0003] According to the EL element, although certain gradient can be implemented by driving in an active matrix method using a thin film transistor (TFT) because its driving voltage is low, the element is easily influenced by moisture and the like, so that it has a short life. In addition, the inorganic EL element is characterized in that it has a long life, a wide operating temperature range and excellent decay durability as compared with the organic EL element. Meanwhile, since a voltage required to emit light in the inorganic EL element is as high as 200V to 300V in general, it is difficult to drive it in the active matrix method using the thin film transistor (TFT). Therefore, the inorganic EL element has been driven by a passive matrix method.
[0004] According to the passive matrix driving, a plurality of scan electrodes extending parallel to a first direction and a plurality data electrodes extending parallel to a second direction which is perpendicular to the first direction are provided, a phosphor element is sandwiched between the scan electrode and the data electrode which intersect with each other, and one phosphor element is driven when an AC voltage is applied between the pair of scan electrode and data electrode. Since average luminance becomes low as a whole of the display device as the number of the scanning lines is increased in the passive matrix driving, it is necessary to improve the luminance as the phosphor element. In addition, the inorganic light emitter is provided by doping a phosphor material in an insulator crystal in general and it emits light when UV light is irradiated, but even when an electric field is applied, electrons are not likely to be spread and reaction against charging is strong, so that a high-energy electron is needed to emit light. Therefore, it is necessary to take measures to emit light with low-energy electrons.
[0005] According to the technique described in Japanese Patent Publication No. 54-8080, Mn, Cr, Tb, Eu, Tm, Yb or the like is doped in a phosphor layer including ZnS mainly to drive (flash) an inorganic EL element, so that emission luminance can be improved, but since it can be driven at high voltage of 200V to 300V only, the TFT cannot be used.
[0006] In addition, Japanese Patent Laid-open Publication No. 8-307011 discloses a phosphor element using silicon fine particles. According to the phosphor element, since a size of the silicon fine particle is very small such as 50 nm, a quantum effect is generated and a band gap width becomes a visible light region. Thus, the light is emitted in the visible light region.
SUMMARY OF THE INVENTION
[0007] When the phosphor element is used as a high-quality display device in a television and the like, it is necessary to drive the phosphor element at a low voltage so that the TFT can be used.
[0008] It is an object of the present invention to provide a phosphor element which can be driven at a low voltage and can use a thin film transistor.
[0009] A phosphor element according to the present invention includes a pair of electrodes opposed to each other, a phosphor layer sandwiched between the pair of electrodes and having silicon fine particles whose average particle diameter is not more than 100 nm. Then, at least a part of a surface of the silicon fine particle is covered with a conductive material.
[0010] When an external electric field is applied to the phosphor layer and electrons are spread in silicon fine particles, silicon emits light by a quantum effect. In this case, the inventor of the present invention found that when a surface of the silicon fine particle having a particle diameter of 100 nm or less was covered with a conductive material, the electrons could be easily spread in the silicon fine particles and light was emitted at a low voltage.
[0011] Each component of the phosphor element according to the present invention will be described.
[0012] The phosphor element may be fixed onto a substrate. The substrate is formed of a material having high electric insulation. When light of the phosphor element is emitted from the substrate side, the substrate is formed of a material having high optical transparency in a visible region. When a temperature of the substrate reaches several hundred of ° C. at a manufacturing step of the phosphor element, a material which has a high softening point, excellent heat resistance and thermal expansion coefficient which is almost the same as that of a laminated layer is to be used. Although glass, ceramics, a silicon wafer may be used in such substrate, non-alkali glass may be used so that alkali ion and the like contained in normal glass may not affect the phosphor element. In addition, alumina and the like may be coated on a glass surface as an ion barrier layer of alkali ion for the phosphor element.
[0013] The electrode is formed of a material in which an electric conduction property is high and there is no migration of ion by the electric field. For example, aluminum, molybdenum, tungsten may be used for the electrode. Since the electrode of the phosphor element on the phosphor side may be formed of a material having high transparency in the visible region in addition to the above performance, an electrode mainly formed of tin doped indium oxide (ITO) and the like can be used for the above electrode. In addition, when both of the pair of electrodes are transparent electrodes, both-side phosphor element can be provided. Furthermore, the phosphor element and the display device according to the present invention may be driven by a DC current, an AC current or a pulse.
[0014] For the conductive material, conductive inorganic material which is transparent in the visible region can be used. It is preferable that the conductive material includes an oxide or a composite oxide containing at least one element selected from a group of indium, tin, zinc, and gallium. The oxide material may include Ga 2 O 3 , GaInO 3 , In 2 O 3 , SnO 2 , In 4 Sn 3 O 12 , ZnO, CdIn 2 O 4 , Cd 2 SnO 2 , Zn 2 SnO 4 , MgIn 2 O 4 , ZnGa 2 O 4 , CdGa 2 O 4 , CaGa 2 O 4 , AgInO 2 , InGaMgO 4 , InGaZnO 4 , and the like. In addition, as another example, it is preferable that the conductive material includes a nitride (for example, titanium nitride) or a composite nitride containing at least one element selected from a group of titanium, zirconium, hafnium, gallium, and aluminum. As still another example, a thin film of metal such as gold, silver, platinum, copper, rhodium, palladium, aluminum, chrome and the like or an alloy containing mainly the above (magnesium silver alloy, for example) may be used. In addition, the silicon fine particles having the conductive material on at least one part of its surface may be dispersed in a transparent conductor matrix material. The transparent conductor matrix material preferably includes polyacetylene series; polyphenylene series such as polyparaphenylene, polyphenylenevinylene, poliphenylenesulfide, polyphenyleneoxide; heterocyclic polymer series such as polypyrrole, polythiophene, polyfurane, polyselenophene, polytellurophene; ionic polymer series such as polyaniline; polyacene series; polyester series; metal phthalocyanine series, these derivative, copolymer and mixture, and the like. As a more preferable example, there are poly-N-vinylcarbozole (PVK), polyethylenedioxythiophene (PEDOT), polystyrenesulfonate (PPS), polymethylphenylsilane (PMPS) and the like. Furthermore, a polymer having electron transport property which will be described in detail below may be used. Still furthermore, its electro conductivity may be adjusted by dispersing low-molecular organic material having the electron transport property, or conductive or semi-conductive inorganic material, in the conductive or semi-conductive polymer.
[0015] An electron transport layer formed of the material including the electron transport property may be formed between the electrode and the phosphor layer. The material including the electron transport property is a material having high electron mobility, which can promptly transport electrons in the electron transport layer. In a case of the organic material, a material mainly including aluminum quinolinate or oxadiazole derivative may be used, and in a case of the inorganic material, a single-crystalline body, polycrystalline body of an n-type semiconductor material and a resin diffused layer and the like of its particle powder can be used.
[0016] An electron hole transport layer formed of a material having electron hole transport property may be formed between the electrode and the phosphor layer. The electron hole transport layer may be provided between the electrode serving as a positive electrode and the phosphor layer. The material having the electron hole transport property is a material having high electron hole mobility, which promptly transports the electron hole in the electron hole transport layer, and a material mainly including polyvinyl carbozole series or polyphenylenevinylene series may be used.
[0017] A constitution of the phosphor element according to the present invention will be described.
[0018] As shown in FIG. 1 , the phosphor element includes a phosphor layer containing silicon fine particles having at least one part of the surface covered with the conductive material as the light emitter, between the pair of electrodes opposed to each other. That is, the phosphor element has a fundamental constitution in which the phosphor layer is sandwiched between the pair of electrodes and each electrode is connected to a power supply. In addition, the electrode may be formed on the substrate. Furthermore, the silicon fine particles having a surface covered with the conductive material may be dispersed in the transparent conductor matrix. In addition, the electron transport layer may be provided between the electrode and the phosphor layer. Furthermore, an electron injection layer may be provided between the electron transport layer and the electrode. In addition, the electron hole transport layer may be provided between the electrode serving as the positive electrode and the phosphor layer. Still furthermore, the electron hole injection layer may be provided between the electron hole transport layer and the positive electrode. Since the phosphor element is driven at the low voltage, when the thin film transistor (TFT) is provided in the structure, the display can implement active matrix driving at the low voltage.
[0019] Next, a condition to provide sufficient emission efficiency in the phosphor element will be discussed. The phosphor element is driven when the external electric field is applied to the electrode of the phosphor element, and the electrons are transported to the light emitter in the phosphor layer by the applied external electric field. Since the silicon fine particles having a size of 100 nm or less are provided in the center of the light emitter, when the electrons are spread in the center of the light emitter, silicon is excited by the quantum effect to emit light. Since the surface of the silicon fine particle is covered with the conductive material, the electrons are easily spread in the silicon fine particles of the center.
[0020] Here, the silicon fine particles are excited by transmitted electron energy, and then, the silicon fine particle emits light when it is changed from excited state to ground state. That is, as the particle diameter of the silicon fine particle becomes small, the quantum effect is more provided to enlarge the band gap. Thus, although the silicon fine particle having a particle diameter 100 nm or less emits light in a visible light region, as the particle diameter becomes small, its surface area is increased and the particles become unstable. Therefore, it is necessary to cover the silicon fine particle surface in order to keep the small particle diameter stably. In this case, it is preferable that the surface of the silicon fine particle is covered with the conductive material. Thus, energy can be effectively transmitted to the silicon atoms in the silicon fine particles.
[0021] In addition, when the electron transport layer is provided on the phosphor layer, the electrons can be effectively transmitted to the silicon fine particle. Furthermore, when the phosphor layer is sandwiched between the two electron transport layers formed of the material having the electron transport property, since the material serves as an electron hole stopper also, the transmitted electrons are not connected to the electron hole again, and the electrons can be effectively transmitted to the silicon fine particles.
[0022] According to the phosphor element of the present invention, at least one part of the surface of the silicon fine particle is covered with the conductive material, and the silicon fine particles are used as the light emitters. Thus, light can be emitted in the visible light region by the quantum effect and it can be chemically stabled. In addition, the phosphor element can be driven at the low voltage and the light can be emitted with high efficiency by the silicon fine particles.
BRIEF DESCRIPTION OF DRAWINGS
[0023] These objects and other objects, features, aspects and advantages of the present invention will become more apparent from the following detailed description of the present invention when taken in conjunction with the accompanying drawings:
[0024] FIG. 1 is a sectional view showing a constitution of a phosphor element according to a first embodiment of the present invention;
[0025] FIG. 2 is a sectional view showing a constitution of a phosphor element according to an eighth embodiment of the present invention;
[0026] FIG. 3 is a perspective view showing an electrode constitution of a phosphor element according to a ninth embodiment of the present invention;
[0027] FIG. 4 is a schematic plain view showing a display device according to a tenth embodiment of the present invention;
[0028] FIG. 5 is a sectional view showing another constitution of a phosphor element according to a fourth embodiment of the present invention; and
[0029] FIG. 6 is a sectional view showing another constitution of a phosphor element according to an eighth embodiment of the present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0030] Although a phosphor element according to embodiments of the present invention will be described in detail with reference to the accompanying drawings hereinafter, the present invention is not limited to the embodiments. In addition, the same reference numerals are allotted to substantially the same components in the drawings.
First Embodiment
[0031] A phosphor element according to a first embodiment of the present invention will be described with reference to FIG. 1 . FIG. 1 is a schematic view showing an element structure of the phosphor element 10 . The phosphor element 10 has a phosphor layer 3 sandwiched between two first and second electrodes 2 and 4 . According to a laminated relation of each layer, a transparent board 1 is provided as a substrate, and the first electrode 2 , the phosphor layer 3 and the second electrode 4 are laminated in this order thereon in the phosphor element 10 . In addition, light is emitted from the side of the transparent board 1 .
[0032] In addition, in the phosphor element 10 , although a luminescent color emitted from the phosphor element is determined by silicon fine particles which constitute the phosphor layer 3 , a color conversion layer may be provided ahead of the phosphor direction of the phosphor layer 3 or a color conversion material may be mixed in a transparent conductor matrix in order to display multiple colors, or white color or to adjust color purity of each color and the like. Since the color conversion layer and the color conversion material may only have to emit light as an excitation source, it may be an organic material or an inorganic material, so that a well-known fluorescent material, a pigment, a dye and the like can be used. For example, when the color conversion layer which emits light in complementary color to that of the light from the phosphor layer 3 is provided, a surface light source which emits white light can be provided.
[0033] The luminescent characteristics of the phosphor element 10 will be described. Extracting electrodes from the ITO transparent electrode (first electrode) 2 and the Ag electrode (second electrode) 4 , then, applying an external voltage between the ITO transparent electrode 2 and the Ag electrode 4 causes the phosphor element 10 to be emitted. In addition, according to the phosphor element in the first embodiment, a silicon fine particle surface having a particle diameter of 10 to 30 nm is covered with a titanium nitride film having a thickness of 10 to 30 nm. Next, a manufacturing method of the phosphor element 10 will be described. The phosphor element was manufactured according to the following procedures.
(a) A non-alkali glass substrate was used as the substrate 1 . A thickness of the substrate 1 was 1.7 mm. (b) The ITO transparent electrode 2 was formed on the substrate 1 using an ITO oxide target as the first electrode 2 by a RF magnetron sputtering method. (c) The phosphor layer 3 in which the silicon fine particle 5 was covered with a conductive material 6 was formed on the ITO transparent electrode 2 by an evaporation method. (d) The Ag electrode paste was screen-printed on the phosphor element 3 as the second electrode 4 and dried to form the second electrode 4 .
[0038] According to the above steps, the phosphor element 10 was formed.
[0039] When the first electrode 2 and the second electrode 4 of the phosphor element 10 were connected to a positive electrode and a negative electrode of a DC power supply 7 , respectively and a DC voltage was applied to them, bright emission at 4.5V was confirmed. Since the phosphor element 10 can be driven at a low voltage, a pixel can be controlled by the TFT
Second Embodiment
[0040] A phosphor element according to a second embodiment of the present invention will be described. This phosphor element is the same as the phosphor element 10 according to the first embodiment other than that a particle diameter of a silicon fine particle 5 is different. The particle diameter of the silicon fine particle 5 was 5 to 20 nm.
[0041] When a first electrode 2 and a second electrode 4 of the phosphor element according to the second embodiment were connected to a positive electrode and a negative electrode of a DC power supply 7 , respectively and a DC voltage was applied to them, bright emission at 3.6V was confirmed. Since the phosphor element according to the second embodiment can be driven at a low voltage, a pixel can be controlled by the TFT.
Third Embodiment
[0042] A phosphor element according to a third embodiment of the present invention will be described. This phosphor element is the same as the phosphor element 10 according to the first embodiment other than that a particle diameter of a silicon fine particle 5 is different. The particle diameter of the silicon fine particle 5 was 70 to 100 nm. When a first electrode 2 and a second electrode 4 of the phosphor element according to the third embodiment were connected to a positive electrode and a negative electrode of a DC power supply 7 , respectively and a DC voltage was applied to them, bright emission at 22V was confirmed. Since the phosphor element according to the third embodiment can be driven at a low voltage, a pixel can be controlled by the TFT
Fourth Embodiment
[0043] A phosphor element according to a fourth embodiment of the present invention will be described. This phosphor element is the same as the phosphor element 10 according to the first embodiment other than that a conductive material 6 is a magnesium silver alloy. A molecule ratio of magnesium and silver was 10:1 and a film thickness was 5 to 50 nm. When a first electrode 2 and a second electrode 4 of the phosphor element according to the fourth embodiment were connected to a positive electrode and a negative electrode of a DC power supply 7 , respectively and a DC voltage was applied to them, bright emission at 3.1V was confirmed. Since the phosphor element according to the fourth embodiment can be driven at a low voltage, a pixel can be controlled by the TFT.
[0044] In addition, when a metal material is used instead of a semiconductor material as the conductive material which covers the silicon fine particles, it is preferable that not entire surface of the silicon fine particle but only a part of thereof is covered with the conductive material. In this case, as shown in FIG. 5 , the phosphor layer 3 may be constituted by diffusing such silicon fine particles 15 in which a part of the surface is covered with a conductive material 16 formed of the metal material in a transparent conductor matrix 17 formed of a semiconductor material.
Fifth Embodiment
[0045] A phosphor element according to a fifth embodiment of the present invention will be described. This phosphor element is the same as the phosphor element according to the fourth embodiment other than that a particle diameter of a silicon fine particle 5 is different. The particle diameter of the silicon fine particle 5 was 70 to 100 nm. When a first electrode 2 and a second electrode 4 of the phosphor element according to the fifth embodiment were connected to a positive electrode and a negative electrode of a DC power supply 7 , respectively and a DC voltage was applied to them, bright emission at 19V was confirmed. Since the phosphor element according to the fifth embodiment can be driven at a low voltage, a pixel can be controlled by the TFT.
Sixth Embodiment
[0046] A phosphor element according to a sixth embodiment of the present invention will be described. This phosphor element is the same as the phosphor element according to the third embodiment other than that a conductive material 6 is mainly formed of Ga 2 0 3 . A particle diameter of a silicon fine particle 5 was 70 to 100 nm. When a first electrode 2 and a second electrode 4 of the phosphor element according to the sixth embodiment were connected to a positive electrode and a negative electrode of a DC power supply 7 , respectively and a DC voltage was applied to them, bright emission at 21V was confirmed. Since the phosphor element according to the sixth embodiment can be driven at a low voltage, a pixel can be controlled by the TFT
Seventh Embodiment
[0047] A phosphor element according to an seventh embodiment of the present invention will be described. This phosphor element is the same as the phosphor element according to the sixth embodiment other than that a conductive material 6 is mainly formed of In 4 Sn 3 O 12 . A particle diameter of a silicon fine particle 5 was 70 to 100 nm. When a first electrode 2 and a second electrode 4 of the phosphor element according to the seventh embodiment were connected to a positive electrode and a negative electrode of a DC power supply 7 , respectively and a DC voltage was applied to them, bright emission at 16V was confirmed. Since the phosphor element according to the seventh embodiment can be driven at a low voltage, a pixel can be controlled by the TFT.
[0048] In addition, in the phosphor element according to the second embodiment to seventh embodiment, although a luminescent color is determined by silicon fine particles 5 which constitute the phosphor layer 3 , a color conversion layer may be provided ahead of the phosphor direction of the phosphor layer 3 or a color conversion material may be mixed in the transparent conductor matrix in order to display multiple colors, or a white color or to adjust color purity of each color similar to the first embodiment.
Eighth Embodiment
[0049] A phosphor element according to an eighth embodiment of the present invention will be described with reference to FIG. 2 . FIG. 2 is a sectional view showing a constitution of a phosphor element 20 . The phosphor element 20 is different from that in the first embodiment to seventh embodiment in that a first electron transport layer 8 is provided between a phosphor layer 3 and a first electrode 2 , and a second electron transport layer 9 is provided between the phosphor layer 3 and a second electrode 4 . Electrons can flow into the phosphor layer 3 well because of these electron transport layers 8 and 9 . In addition, when the first electrode 2 and the second electrode 4 of the phosphor element according to the eighth embodiment are connected to a positive electrode and a negative electrode of a DC power supply 7 , respectively, the first electron transport layer 8 provided on the side of the first electrode 2 functions as an electron hole stopper layer. As a material constituting the electron transport layers 8 and 9 , there are two main types of an organic material such as a low-molecular material and a high-molecular material.
[0050] The low-molecular material including an electron transport property includes an oxadiazole derivative, a triazole derivative, a styrylbenzene derivative, a silole derivative, 1,10-phenanthroline derivative, a quinolinol series metal complex, a thiophene derivative, a fluorene derivative, a quinone derivative, and the like or their dimer or trimer. More preferably, although the following material may be used, the present invention is not limited to these, that is, 2-(4-biphenyl)-5-(4-tert-butylphenyl)-1,3,4-oxadiazole (PBD); 2,5-biss(1-naphtyl)-1,3,4-oxadiazole (BND); 2,5-bis[1-(3-methoxy)-phenyl]-1,3,4-oxadiazole (BMD); 1,3,5-tris[5-(4-tert-butylphenyl)-1,3,4-oxadiazole-2-yl]benzene (TPOB); 3-(4-biphenyl)-4-phenyl-5-(4-tert-butylphenyl)-1,2,4-triazole (TAZ); 3-(4-biphenyl)-4-(4-ethylphenyl)-5-(4-tert-butylphenyl)-1,2,4-triazole(p-EtTAZ); 4,7-diphenyl-1,10-phenanthroline (BPhen); 2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline (BCP); 3,5-dimethl-3′,5′-di-tert-butyl-4,4′-diphenoquinone (MBDQ); 2,5-bis[2-(5-tert-butylbenzoxazolyl)]-thiophene (BBOT); trynitrofluorenone (TNF); tris(8-quinolinolato) aluminum (Alq3); and 5,5′-bis(dimesitylboryl)-2,2′bithiophene (BMB-2T) and the like.
[0051] In addition, the high-molecular material including the electron transport property includes poly-[2-methoxy-5-(2-etyhlhexyloxy)-1,4-(1-cyanovinylene) phenylene] (CN-PPV), polyquinoxaline, and a low-molecule polymer and the like incorporating a molecular structure which shows the electron transport property, in a molecular chain. Furthermore, molecules of the above low-molecular material may be diffused in a conductive or non-conductive polymer. In addition, a single-crystalline body of an n-type semiconductor material in which electrons can be well injected and there is no absorption in a visible light range as represented by zinc oxide (ZnO), indium oxide (In 2 O 3 ), titanium oxide (TiO 2 ) and the like, its polycrystalline body, or a resin diffused layer of its particle powder and the like may be used.
[0052] In addition, when the metal material is used as the conductive material which covers the silicon fine particles instead of the semiconductor material, it is preferable that not entire surface of the silicon fine particle but only a part thereof is covered with the conductive material. In this case, as shown in FIG. 6 , the phosphor layer 3 may be constituted by diffusing such silicon fine particles 15 in which one part of the surface is covered with a conductive material 16 formed of a metal material, in a transparent conductor matrix 17 formed of a semiconductor material.
Ninth Embodiment
[0053] A phosphor element 30 according to a ninth embodiment of the present invention will be described with reference to FIG. 3 . FIG. 3 is a perspective view showing an electrode constitution of the phosphor element 30 . The phosphor element 30 further includes a thin film transistor 11 connected to the electrode 2 of the phosphor element according to the first embodiment to eighth embodiment. An x electrode 12 and a y electrode 13 are connected to the thin film transistor 11 . According to the phosphor element 30 , since at least a part of a surface of a silicon fine particle 5 is covered with a conductive material 6 , it can be driven at a low voltage and the thin film transistor 11 can be used. In addition, when the thin film transistor 11 is used, the phosphor element 30 has a memory function. As this thin film transistor 11 , low-temperature polysilicon or amorphous silicon thin film transistor and the like may be used. Furthermore, it may be an organic thin film transistor constituted by a thin film including an organic material, or may be a transparent thin film transistor formed of zinc oxide and the like.
Tenth Embodiment
[0054] A display device according to a tenth embodiment of the present invention will be described with reference to FIG. 4 . FIG. 4 is a schematic plain view showing an active matrix of the display device 40 which is constituted by x electrodes 12 and y electrodes 13 intersecting with each other. The display device 40 is an active matrix display device having a thin film transistor 11 . The active matrix display device 40 includes a two-dimensional phosphor element array in which a plurality of phosphor elements 30 including the thin film transistors 11 shown in FIG. 3 are arranged, the plurality of x electrodes extending parallel to each other in a first direction which is parallel to a surface of the phosphor element array, and the plurality of y electrodes 13 extending parallel to each other in a second direction which intersects with the first direction at right angles. The thin film transistor 11 in the phosphor element connects the x electrode 12 to the y electrode 13 . The phosphor element specified by the pair of x electrode 12 and y electrode 13 becomes a pixel. According to the active matrix display device 40 , as described above, a phosphor layer 3 constituting the phosphor element of each pixel includes silicon fine particles 5 in which at least a part of its surface is covered with a conductive material 6 . Thus, since it can be driven at a low voltage, the thin film transistor 11 can be used and a memory effect can be provided. In addition, since it can be driven at the low voltage, the display device has a long life. In addition, when the silicon fine particles 5 constituting the phosphor layer 3 are arranged in each pixel depending on its luminescent color (RGB), there can be provided a full-color display device using the three primary colors. In addition, a color filter may be provided ahead of the phosphor direction in order to adjust the color purity of each color of RGB. Furthermore, the phosphor layer 3 emitting one color to every pixel may be used, and a color conversion layer and the color filter may be further provided ahead of the phosphor direction. Thus, when the color conversion layer absorbs blue light generated from the phosphor layer 3 , green or red light is generated and when they are taken out respectively, there can be provided a full-color display device using the three primary colors according to another example.
COMPARATIVE EXAMPLE 1
[0055] A phosphor element according to a comparative example will be described. This phosphor element is the same as the phosphor element 10 according to the first embodiment other than that a particle diameter of a silicon fine particle is different and there is no conductive material on a surface. A particle diameter of a silicon fine particle in the comparative example 1 was 180 to 220 nm. When a first electrode 2 and a second electrode 4 of the phosphor element according to comparative example 1 were connected to a positive electrode and a negative electrode, respectively and a DC voltage was applied to them, bright emission at 103V was confirmed. Since the phosphor element according to the comparative example 1 is driven at a high voltage, it is difficult or impossible to control a pixel by the TFT
COMPARATIVE EXAMPLE 2
[0056] A phosphor element according to a comparative example 2 will be described. This phosphor element is the same as the phosphor element 10 according to the first embodiment other than that a particle diameter of a silicon fine particle is different. A particle diameter of a silicon fine particle in the comparative example 2 was 200 to 240 nm. Although a first electrode 2 and a second electrode 4 of the phosphor element according to the comparative example 2 were connected to a positive electrode and a negative electrode, respectively and a DC voltage was applied to them, emission could not be confirmed even at 200V
COMPARATIVE EXAMPLE 3
[0057] A phosphor element according to a comparative example 3 will be described. This phosphor element is the same as the phosphor element according to the fourth embodiment other than there is no conductive material. Although a first electrode 2 and a second electrode 4 of the phosphor element according to the comparative example 3 were connected to a positive electrode and a negative electrode, respectively and a DC voltage was applied to them, emission could not be confirmed even at 200V.
COMPARATIVE EXAMPLE 4
[0058] A phosphor element according to a comparative example 4 will be described. This phosphor element is the same as the phosphor element according to the fourth embodiment other than a film thickness of a magnesium silver alloy is different and the film thickness is 60 to 100 nm. Although a first electrode 2 and a second electrode 4 of the phosphor element according to the comparative example 4 were connected to a positive electrode and a negative electrode, respectively and a DC voltage was applied to them, emission could not be confirmed even at 200V
COMPARATIVE EXAMPLE 5
[0059] A phosphor element according to a comparative example 5 will be described. This phosphor element is the same as the phosphor element 10 according to the first embodiment other than a film thickness of titanium nitride which is the conductive material is different and the film thickness is 40 to 80 nm. Although a first electrode 2 and a second electrode 4 of the phosphor element according to the comparative example 5 were connected to a positive electrode and a negative electrode, respectively and a DC voltage was applied to them, emission could not be confirmed even at 200V.
[0060] As described above, although the present invention has been described in detail by the preferred embodiments, the present invention is not limited to the embodiments, and as will be understood by those skilled in the art, many preferred variations and modifications can be made in a technical scope of the present invention described in the following claims. | A phosphor element includes a pair of electrodes opposed to each other and a phosphor layer sandwiched between the pair of electrodes and having silicon fine particles whose average particle diameter is not more than 100 nm, and at least a part of a surface of the silicon fine particle is covered with a conductive material. In addition, the conductive material may include an oxide or a composite oxide containing at least one element selected from a group of indium, tin, zinc, and gallium. | 2 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates generally to circuit board fixing structures, and more particularly to a fixing structure for a circuit board of an electronic device.
2. Description of Related Arts
As the technology advances, electronic devices such as desktop computers, laptop computers and services have played an important role in daily life. Each electronic device is provided with a circuit board (or a motherboard) fixed to a housing of the electronic device. Various ways of fixing the circuit board to the electronic device are available and cause different effects on the circuit board.
One of conventional methods is that a housing of an electronic device is formed with a plurality of carried pads thereon, wherein each of the carried pads has a blind hole. A circuit board has a plurality of openings corresponding to the blind holes of the carried pads and is placed on the carried pads. The circuit board is fixed to the housing of the electronic device by a plurality of coupling members such as screws inserted into the openings and the blind holes. To fix the above circuit board to the housing of the electronic device needs a screwdriver or a similar tool to screw the coupling members, which is rather troublesome and time-consuming to implement. If a force for screwing the coupling members is not proper, the circuit board may be damaged by the coupling members. Moreover, since the coupling members are often made of metallic material having electrical conductivity, a signal interference is existed with the circuit board.
A non-reversible method for fixing a circuit board to an electronic device is to use sticky substance. When the circuit board or some component of the electronic device has some blemish, it is difficult to remove the blemished member and the whole circuit board is broken and useless.
A third fixing method is shown in a circuit board fixing structure comprising a carrier for carrying a circuit board formed with a plurality of through holes, a pillar penetrating one of the through holes and a stud with a handler portion. The pillar has a first opening and a second opening corresponding to the first opening. A user holds the handler portion of the stud and let the stud penetrate the first and second openings, the stud fixes the circuit board on the carrier. However, too many components and too many steps increase the cost of the product. Furthermore, the stud of this circuit board fixing structure maybe fall off from the pillar, and as a result, a fixing effect can't be achieved
Hence, an improved circuit board fixing structure is desired.
SUMMARY OF THE INVENTION
Accordingly, an object of the present invention is to provide a circuit board fixing structure in which a circuit board is easily assembled and tightly fixed.
To achieve the above object, A circuit board fixing structure includes a base and a circuit board. The base has a plurality of elastic claws and the elastic claws vertically extend from the base. Each elastic claw includes a fastening portion, which forms a fastening surface facing to a top surface of the base. The circuit board with edges is encircled by the elastic claws and an upper surface of the circuit board confronts the fastening surface of the fastening portion.
Other objects, advantages and novel features of the invention will become more apparent from the following detailed description when taken in conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWING
FIG. 1 is a perspective, exploded view of a circuit board fixing structure according to this invention; and
FIG. 2 is a perspective, assembled view of the circuit board fixing structure.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring to FIGS. 1 and 2 , an embodiment is shown. A circuit board fixing structure 100 comprises a circuit board 2 and a base 3 on which the circuit board 2 is mounted. The circuit board 2 is approximately shaped as a quadrangle taken from a top view, but the four angles thereof recess to be four cutouts 21 . The base 3 comprises four blocks 31 corresponding to the four cutouts 21 of the circuit board 2 and two pairs of elastic claws 32 locating at two opposite sides and facing to each other. The blocks 31 are used for limiting a movement of the circuit board 2 in a horizontal direction and the elastic claws 32 are used for limiting a movement of the circuit board 2 in a vertical direction. Each elastic claw 32 , extending from an upper surface (not labeled) of the base 3 , comprises a supporting bar 33 and a fastening portion 34 . The supporting bar 33 is flexible and can endure a small deflection. The fastening portion 34 , extending from a distal end of the supporting bar 33 , forms a fastening surface 36 with a downward exposure and an inclined surface 35 for guiding the circuit board 2 when the circuit board 2 is assembled onto the base 3 . Generally speaking, the claw 32 looks like an approximate “P” from a front-to-back direction. The base 3 further comprises a pair of crutch surfaces 37 lying on the upper surface thereof and having upward exposures. One baffle 38 is situated a little distance behind each of the elastic claw 32 for allowing the elastic claw 32 to deflect from an original position but not deflect so deeply. At first, the elastic claws 32 keep in its original position. When the circuit board 2 moves downward under a guidance of the inclined surfaces 35 , a force is pressed on the inclined surfaces 35 and causes a deflection of the supporting bars 33 towards the baffles 38 , accordingly, the circuit board 2 continues to go under the fastening surfaces 36 , and then, the elastic claws 32 resume to the original direction, and the circuit board 2 is sandwiched between the fastening surfaces 36 and the crutch surfaces 37 ultimately. In fact, the number of the cutouts 21 of the circuit board 2 and the number of the corresponding blocks 31 of the base 3 are not limited to be four, that is to say, we are looking forward to limit the horizontal movement of the circuit board 2 , and hence, whether the number of the blocks 31 of the base 3 is four or not is not important. For example, if a hole is existed the circuit board 2 , just only one hole corresponding to the block 31 also can retain the circuit board 2 . Moreover, the number of the edges and the number of the angles of the circuit board 2 are both not limited to be four.
In a second embodiment not shown in FIGS. 1-2 , the circuit board fixing structure 100 lacks the cutouts 21 of the polygonal circuit board 2 and the corresponding blocks 31 of the base 3 of the first embodiment, and at least one elastic claw 32 is mated with each edge of the circuit board 2 for providing a limitation of a horizontal movement of the circuit board 2 and also a limitation of a vertical movement of the circuit board 2 relative to the base 3 . One elastic claw 32 of the base 3 corresponding to one edge of the circuit board 2 is the best in this embodiment, but in practice, users can reduce some elastic claws 32 for simplification.
In a third embodiment similar to the second embodiment, at least one elastic claw 32 is mated with each angle of the circuit board 2 , which can also achieve a limitation of a horizontal movement of the circuit board 2 and a limitation of a vertical movement of the circuit board 2 . In this embodiment, users can also reduce some elastic claws 32 for simplification.
In a fourth embodiment, the circuit board 2 comprises the cutouts 21 and the base 3 comprises elastic claws 32 mating with the cutouts 21 . The supporting bar 33 of the base 3 completely and fully mates with the cutout 21 for providing the limitation of a horizontal movement of the circuit board 2 and the fastening surface 36 confronts an upper surface (not labeled) of the circuit board 2 for providing the limitation of a vertical movement of the circuit board 2 .
In this circuit board fixing structure 100 , when a user assembles the circuit board 2 onto the base 3 , the circuit board 2 moves downward under a guidance of the inclined surfaces 35 and a force is pressed on the inclined surfaces 35 to cause a deflection of the elastic claws 32 and the circuit board 2 to be sandwiched between the fastening surfaces 36 and the crutch surfaces 37 ultimately. It makes the assembling of the circuit board 2 on the base 3 simple and it avoids the circuit board 2 from being destroyed during the assembling process.
While a preferred embodiment in accordance with the present invention has been shown and described, equivalent modifications and changes known to persons skilled in the art according to the spirit of the present invention are considered within the scope of the present invention as described in the appended claims. | A circuit board fixing structure ( 100 ) includes a base ( 3 ) and a circuit board ( 2 ). The base has a plurality of elastic claws ( 32 ) and the elastic claws vertically extend from the base. Each elastic claw includes a fastening portion ( 34 ), which forms a fastening surface ( 36 ) facing to a top surface of the base. The circuit board is encircled by the elastic claws and an upper surface of the circuit board confronts the fastening surface of the fastening portion. | 7 |
CROSS-REFERENCE TO RELATED APPLICATION
This application claims priority to and the benefit of Korean Patent Application No. 10-2010-0113007 filed Nov. 12, 2010, the entire contents of which application is incorporated herein for all purposes by this reference.
BACKGROUND OF INVENTION
1. Field of Invention
The present invention relates to a gear train of an automatic transmission for vehicles which realizes at least nine forward speeds and one reverse speed by combining three simple planetary gear sets with four clutches and three brakes.
2. Description of Related Art
A typical shift mechanism of an automatic transmission utilizes a combination of a plurality of planetary gear sets. A gear train of such an automatic transmission that includes the plurality of planetary gear sets changes rotational speed and torque received from a torque converter of the automatic transmission, and accordingly transmits the changed torque to an output shaft.
In such an automatic transmission, a gear train is realized by combining a plurality of planetary gear sets, and the gear train including the plurality of planetary gear sets receives torque from a torque converter and changes and transmits the torque to an output shaft.
It is well known that when a transmission realizes a greater number of shift speeds, speed ratios of the transmission can be more optimally designed, and therefore a vehicle can have economical fuel mileage and better performance. For that reason, an automatic transmission that is able to realize more shift speeds is under continuous investigation.
In addition, with the same number of speeds, features of a gear train, such as durability, efficiency in power transmission, and size, substantially depend on the layout of the combined planetary gear sets. Therefore, designs for a combining structure of a gear train are also under continuous investigation.
A manual transmission that has too many speeds causes inconvenience to a driver. Therefore, the advantageous features of having more shift-speeds are more important in an automatic transmission because an automatic transmission automatically controls the shifting operations
Currently, four-speed and five-speed automatic transmissions are most often found on the market. However, six-speed automatic transmissions have also been realized for enhancement of performance of power transmission and for enhanced fuel mileage of a vehicle. In addition, seven-speed automatic transmissions and eight-speed automatic transmissions have been developed at a good pace.
The information disclosed in this Background section is only for enhancement of understanding of the general background of the invention and should not be taken as an acknowledgement or any form of suggestion that this information forms the prior art already known to a person skilled in the art.
SUMMARY OF INVENTION
Various aspects of the present invention provide for a gear train of an automatic transmission for vehicles having advantages of simplifying structures of the automatic transmission and improving power delivery performance and fuel economy as a consequence of realizing at least nine forward speeds and one reverse speed by combining three simple planetary gear sets with four clutches and three brakes.
One aspect of the present invention is directed to a gear train of an automatic transmission for vehicles that may include a first rotation element having a first member of the first planetary gear set directly connected to an input shaft so as to be always operated as an input element, a second rotation element having a second member of the first planetary gear set forming a first intermediate output path through which a reduced rotation speed is output and operated as a selective fixed element, a third rotation element having a third member of the first planetary gear set forming a second intermediate output path through which an inverse rotation speed is output and operated as a selective fixed element, a fourth rotation element having a first member of the second planetary gear set connected selectively to the first and second intermediate output paths so as to form a first variable input path and operated as a selective fixed element, a fifth rotation element having a second member of the second planetary gear set and a first member of the third planetary gear set selectively connected to an input shaft so as to form a second variable input path and operated as a selective fixed element, a sixth rotation element having a second member of the third planetary gear set connected to an output gear so as to form a final output path, a seventh rotation element having a third member of the second planetary gear set and a third member of the third planetary gear set selectively connected to the input shaft so as to form a third variable input path, and friction members having a plurality of clutches selectively connecting each rotation element to the input shaft or another rotation element and a plurality of brakes selectively connecting each rotation element to a transmission housing.
The friction member may include first, second, third, and fourth clutches and first, second, and third brakes, wherein the first clutch selectively connects the third rotation element to the fourth rotation element, the second clutch selectively connects the input shaft to the seventh rotation element, the third clutch selectively connects the second rotation element to the fourth rotation element, the fourth clutch selectively connects the input shaft to the fifth rotation element, the first brake selectively connects the second rotation element to the transmission housing, the second brake selectively connects the fifth rotation element to the transmission housing, and the third brake selectively connects the third rotation element to the transmission housing.
The second brake may be provided with a one-way clutch disposed in parallel therewith.
The first clutch and the first and second brakes may be operated at a first forward speed, the second clutch and the first and second brakes may be operated at a second forward speed, the first and second clutches and the first brake may be operated at a third forward speed, the first and second clutches and the third brake may be operated at a fourth forward speed, the second and third clutches and the third brake may be operated at a fifth forward speed, the second and fourth clutches and the third brake may be operated at a sixth forward speed, the third and fourth clutches and the third brake may be operated at a seventh forward speed, the first and fourth clutches and the third brake may be operated at an eighth forward speed, the first and fourth clutches and the first brake may be operated at a ninth forward speed, the third clutch and the second and third brakes may be operated at a reverse speed.
The first member may be a first sun gear, the second member may be a first planet carrier, and the third member may be a first ring gear in the first planetary gear set.
The first member may be a second ring gear, the second member may be a second planet carrier, and the third member may be a second sun gear in the second planetary gear set.
The first member may be a third ring gear, the second member may be a third planet carrier, and the third member may be a third sun gear.
The methods and apparatuses of the present invention have other features and advantages which will be apparent from or are set forth in more detail in the accompanying drawings, which are incorporated herein, and the following Detailed Description, which together serve to explain certain principles of the present invention.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic diagram of an exemplary gear train according to the present invention.
FIG. 2 is an operational chart for an exemplary gear train according to the present invention.
FIG. 3 is a lever diagram for an exemplary gear train according to the present invention.
DETAILED DESCRIPTION
Reference will now be made in detail to various embodiments of the present invention(s), examples of which are illustrated in the accompanying drawings and described below. While the invention(s) will be described in conjunction with exemplary embodiments, it will be understood that present description is not intended to limit the invention(s) to those exemplary embodiments. On the contrary, the invention(s) is/are intended to cover not only the exemplary embodiments, but also various alternatives, modifications, equivalents and other embodiments, which may be included within the spirit and scope of the invention as defined by the appended claims.
Description of components that are not necessary for explaining the present invention will be omitted, and the same constituent elements are denoted by the same reference numerals in this specification.
In the detailed description, ordinal numbers are used for distinguishing constituent elements having the same terms, and have no specific meanings.
FIG. 1 is a schematic diagram of a gear train according to various embodiments of the present invention. A gear train according to various embodiments of the present invention includes first, second, and third planetary gear sets PG 1 , PG 2 , and PG 3 disposed on the same axis, clutch means consisting of four clutches C 1 , C 2 , C 3 , and C 4 , and brake means consisting of three brakes B 1 , B 2 , and B 3 .
A rotation speed input from the input shaft IS is changed by the first, second, and third planetary gear sets PG 1 , PG 2 , and PG 3 and is output through the output gear OG. At this time, the first planetary gear set PG 1 is disposed at the rearmost, and the second and third planetary gear sets PG 2 and PG 3 are sequentially dispose to the front.
The input shaft IS is an input member and denotes a turbine shaft of a torque converter. Torque transmitted from a crankshaft of the engine is converted by the torque converter and is input to the gear train through the input shaft IS. The output shaft OS is an output member and is connected to a well-known differential apparatus so as to transmit an output of the gear train to driving wheels.
The first planetary gear set PG 1 is a single pinion planetary gear set, and includes three rotation elements consisting of a sun gear, a planet carrier, and a ring gear. For better comprehension and ease of description, the sun gear is indicated by the first sun gear S 1 , the planet carrier is indicated by the first planet carrier PC 1 , and the ring gear is indicated by the first ring gear R 1 .
The first sun gear S 1 is directly connected to the input shaft IS so as to be operated as a first rotation element N 1 forming an input path IP, the first planet carrier PC 1 is selectively connected to a transmission housing H and is operated as a second rotation element N 2 forming a first intermediate output path MOP 1 , and the first ring gear R 1 is selectively connected to the transmission housing H and is operated as a third rotation element N 3 forming a second intermediate output path MOP 2 .
Accordingly, in a state that a rotation speed of the input shaft IS is always input to the first rotation element N 1 , an inverse rotation speed is output through the second intermediate output path MOP 2 if the second rotation element N 2 is operated as a fixed element, and a reduced rotation speed is output through the first intermediate output path MOP 1 if the third rotation element N 3 is operated as a fixed element.
That is, the first planetary gear set PG 1 selectively outputs the reduced rotation speed and the inverse rotation speed.
The second planetary gear set PG 2 is a single pinion planetary gear set and includes three rotation elements consisting of a sun gear, a planet carrier, and a ring gear. For better comprehension and ease of description, the sun gear is indicated by a second sun gear S 2 , the planet carrier is indicated by a second planet carrier PC 2 , and the ring gear is indicated by a second ring gear R 2 .
The third planetary gear set PG 3 is a single pinion planetary gear set and includes three rotation elements consisting of a sun gear, a planet carrier, and a ring gear. For better comprehension and ease of description, the sun gear is indicated by a third sun gear S 3 , the planet carrier is indicated by a third planet carrier PC 3 , and the ring gear is indicated by a third ring gear R 3 .
The second sun gear S 2 is directly connected to the third sun gear S 3 and the second planet carrier PC 2 is directly connected to the third ring gear R 3 such that the second and third planetary gear sets PG 2 and PG 3 forms one compound planetary gear set and includes four rotation elements.
Accordingly, the second ring gear R 2 is operated as a fourth rotation element N 4 , the second planet carrier PC 2 and the third ring gear R 3 are operated as a fifth rotation element N 5 , the third planet carrier PC 3 is operated as a sixth rotation element N 6 , and the second and third sun gears S 2 and S 3 are operated as a seventh rotation element N 7 .
In addition, the second ring gear R 2 of the fourth rotation element N 4 is selectively connected to the first intermediate output path MOP 1 of the second rotation element N 2 and to the second intermediate output path MOP 2 of the third rotation element N 3 so as to form a first variable input path VIP 1 selectively receiving the reduced rotation speed and the inverse rotation speed.
The second planet carrier PC 2 and the third ring gear R 3 of the fifth rotation element N 5 are selectively connected to the input shaft IS so as to form a second variable input path VIP 2 and are selectively connected to the transmission housing H so as to be operated as a selective fixed element.
The third planet carrier PC 3 of the sixth rotation element N 6 is directly connected to the output gear OG which is an output member so as to form a final output path OP.
The second and third sun gears S 2 and S 3 of the seventh rotation element N 7 are selectively connected to the input shaft IS so as to form a third variable input path VIP 3 .
Friction members such as first, second, third, and fourth clutches C 1 , C 2 , C 3 , and C 4 and first, second, and third brakes B 1 , B 2 , and B 3 are used for connection between the rotation elements, connection between each rotation element and the input shaft IS, and connection between each rotation element and the transmission housing H.
The first clutch C 1 is disposed between the third rotation element N 3 and the fourth rotation element N 4 , the second clutch C 2 is disposed between the input shaft IS and the seventh rotation element N 7 , the third clutch C 3 is disposed between the second rotation element N 2 and the fourth rotation element N 4 , the fourth clutch C 4 is disposed between the input shaft IS and the fifth rotation element N 5 , the first brake B 1 is disposed between the second rotation element N 2 and the transmission housing H, the second brake B 2 is disposed between the fifth rotation element N 5 and the transmission housing H, and the third brake B 3 is disposed between the third rotation element N 3 and the transmission housing H.
In addition, the second brake B 2 and a one-way clutch F 1 are disposed in parallel according to various embodiments of the present invention. Since the one-way clutch F 1 is operated instead of the second brake B 2 at a normal first forward speed D 1 , shift shock may be prevented when upshift to a second forward speed D 2 .
If the one-way clutch F 1 is omitted, the second brake B 2 must be operated at the first forward speed D 1 .
The first and third brakes B 1 and B 3 are disposed at an external circumferential portion of the first planetary gear set PG 1 , the first and third clutches C 1 and C 3 are disposed between the first and second planetary gear sets PG 1 and PG 2 , the second brake B 2 including the one-way clutch F 1 is disposed at an external circumferential portion of the second planetary gear set PG 2 or between the second and third planetary gear sets PG 2 and PG 3 , and the second and fourth clutches C 2 and C 4 are disposed at a front portion of the third planetary gear set PG 3 .
If the friction members are dispersed as described above, formation of hydraulic lines for supplying hydraulic pressure to such friction members may be simplified, and weight balance in the automatic transmission may be enhanced.
Friction members consisting of the first, second, third, and fourth clutches C 1 , C 2 , C 3 , and C 4 and the first, second, and third brakes B 1 , B 2 , and B 3 are conventional multi-plate friction elements of wet type that are operated by hydraulic pressure.
FIG. 2 is an operational chart for a gear according to various embodiments of the present invention.
According to various embodiments of the present invention, three friction members are operated at each shift-speed.
That is, the first clutch C 1 and the first and second brakes B 1 and B 2 are operated at the first forward speed D 1 , the second clutch C 2 and the first and second brakes B 1 and B 2 are operated at the second forward speed D 2 , the first and second clutches C 1 and C 2 and the first brake B 1 are operated at a third forward speed D 3 , the first and second clutches C 1 and C 2 and the third brake B 3 are operated at a fourth forward speed D 4 , the second and third clutches C 2 and C 3 and the third brake B 3 are operated at a fifth forward speed D 5 , the second and fourth clutches C 2 and C 4 and the third brake B 3 are operated at a sixth forward speed D 6 , the third and fourth clutches C 3 and C 4 and the third brake B 3 are operated at a seventh forward speed D 7 , the first and fourth clutches C 1 and C 4 and the third brake B 3 are operated at an eighth forward speed D 8 , the first and fourth clutches C 1 and C 4 and the first brake B 1 are operated at a ninth forward speed D 9 , and the third clutch C 3 and the second and third brakes B 2 and B 3 are operated at a reverse speed REV.
At the first and second forward speeds D 1 and D 2 , the one-way clutch F 1 may be operated instead of the second brake B 2 . The second brake B 2 is not operated at a normal forward driving, and the second brake B 2 is operated at L and 2 ranges at which large driving torque is necessary.
FIG. 3 is a lever diagram for a gear train according to various embodiments of the present invention. In the drawings, a lower horizontal line represents a rotational speed is “0”, and an upper horizontal line represents a rotational speed is “1.0”, that is, the rotational speed thereof is the same as that of the input shaft IS.
Three vertical lines of the first planetary gear set PG 1 sequentially represent the first sun gear S 1 being the first rotation element N 1 , the first planet carrier PC 1 being the second rotation element N 2 , and the first ring gear R 3 being the third rotation element N 3 from the left to the right, and distances therebetween are set according to a gear ratio (teeth number of the sun gear/teeth number of the ring gear) of the first planetary gear set PG 1 .
Four vertical lines of the second and third planetary gear sets PG 2 and PG 3 sequentially represent the second ring gear R 2 being the fourth rotation element N 4 , the second planet carrier PC 2 and the third ring gear R 3 being the fifth rotation element N 5 , the third planet carrier PC 3 being the sixth rotation element N 6 , the second and third sun gears S 2 and S 3 being the seventh rotation element N 7 , and distances therebetween are set according to gear ratios (teeth number of the sun gear/teeth number of the ring gear) of the second and third planetary gear sets PG 2 and PG 3 .
Position of each rotation element in the lever diagram is well known to a person of an ordinary skill in the art who designs a gear train, and thus detailed description will be omitted.
First Forward Speed
As shown in FIG. 2 , the first clutch C 1 and the first and second brakes B 1 and B 2 are operated at the first forward speed D 1 .
Accordingly, in a state that the rotation speed of the input shaft IS is input to the first rotation element N 1 forming the input path IP, the second rotation element N 2 is operated as the fixed element by operation of the first brake B 1 . Therefore, the rotation elements of the first planetary gear set PG 1 form a first forward speed line T 1 and the inverse rotation speed is output through the third rotation element N 3 forming the second intermediate output path MOP 2 .
The inverse rotation speed of the second intermediate output path MOP 2 is input to the fourth rotation element N 4 through the first intermediate input path VIP 1 by operation of the first clutch C 1 , and the fifth rotation element N 5 is operated as the fixed element by operation of the second brake B 2 . Therefore, the rotation elements of the second and third planetary gear sets PG 2 and PG 3 form a first shift line SP 1 , and the first shift line SP 1 crosses the vertical line of the sixth rotation element N 6 that is the output element so as to output the first forward speed D 1 .
Second Forward Speed
The first clutch C 1 which was operated at the first forward speed D 1 is released and the second clutch C 2 is operated at the second forward speed D 2 .
The rotation speed of the input shaft IS is input to the seventh rotation element N 7 through the third variable input path VIP 3 by operation of the second clutch C 2 , and the fifth rotation element N 5 is operated as the fixed element by operation of the second brake B 2 . Therefore, the rotation elements of the second and third planetary gear sets PG 2 and PG 3 form a second shift line SP 2 , and the second shift line SP 2 crosses the vertical line of the sixth rotation element N 6 that is the output element so as to output the second forward speed D 2 .
At this time, the rotation speed of the input shaft IS is input to the first planetary gear set PG 1 through the input path IP, but it does not affect on shifting because the first and third clutches C 1 and C 3 connected to the second and third planetary gear sets PG 2 and PG 3 are not operated.
In addition, it is exemplified that the second brake B 2 is operated at the first and second forward speeds D 1 and D 2 , but the one-way clutch F 1 performs function of the second brake B 2 even though the second brake B 2 is not operated. If the one-way clutch F 1 is operated at the second forward speed D 2 , shift feel may be improved when upshift to the third forward speed D 3 .
Third Forward Speed
As shown in FIG. 2 , the second brake B 2 which was operated at the second forward speed D 2 is released and the first clutch C 1 is operated at the third forward speed D 3 .
Accordingly, in a state that the rotation speed of the input shaft IS is input to the first rotation element N 1 forming the input path IP, the second rotation element N 2 is operated as the fixed element by operation of the first brake B 1 such that the rotation elements of the first planetary gear set PG 1 form the first forward speed line T 1 . Therefore, the inverse rotation speed is output through the third rotation element N 3 forming the second intermediate output path MOP 2 .
At this state, the rotation speed of the input shaft IS is input to the seventh rotation element N 7 through the third variable input path VIP 3 by operation of the second clutch C 2 and the inverse rotation speed is input to the fourth rotation element N 3 by operation of the first clutch C 1 . Therefore, the rotation elements of the second and third planetary gear sets PG 2 and PG 3 form a third shift line SP 3 , and the third shift line SP 3 crosses the vertical line of the sixth rotation element N 6 that is the output element so as to output the third forward speed D 3 .
Fourth Forward Speed
As shown in FIG. 2 , the first brake B 1 which was operated at the third forward speed D 3 is released and the third brake B 3 is operated at the fourth forward speed D 4 .
Accordingly, in a state that the rotation speed of the input shaft IS is input to the first rotation element N 1 forming the input path IP, the third rotation element N 3 is operated as the fixed element by operation of the third brake B 3 . Therefore, the rotation elements of the first planetary gear set PG 1 form a second forward speed line T 2 and the fourth rotation element N 4 is operated as the fixed element by operation of the first clutch C 1 .
At this state, the rotation speed of the input shaft IS is input to the seventh rotation element N 7 through the third variable input path VIP 3 by operation of the second clutch C 2 . Therefore, the rotation elements of the second and third planetary gear sets PG 2 and PG 3 form a fourth shift line SP 4 , and the fourth shift line SP 4 crosses the vertical line of the sixth rotation element N 6 that is the output element so as to output the fourth forward speed D 4 .
Fifth Forward Speed
As shown in FIG. 2 , the first clutch C 1 which was operated at the fourth forward speed D 4 is released and the third clutch C 3 is operated at the fifth forward speed D 5 .
Accordingly, in a state that the rotation speed of the input shaft IS is input to the first rotation element N 1 forming the input path IP, the third rotation element N 3 is operated as the fixed element by operation of the third brake B 3 . Therefore, the rotation elements of the first planetary gear set PG 1 form the second forward speed line T 2 and the reduced rotation speed is output through the first intermediate output path MOP 1 of the second rotation element N 2 .
At this state, the reduced rotation speed is input to the fourth rotation element N 4 through the first variable input path VIP 1 by operation of the third clutch C 3 , and the rotation speed of the input shaft IS is input to the seventh rotation element N 7 through the third variable input path VIP 3 by operation of the second clutch C 2 . Therefore, the rotation elements of the second and third planetary gear sets PG 2 and PG 3 form a fifth shift line SP 5 , and the fifth shift line SP 5 crosses the vertical line of the sixth rotation element N 6 that is the output element so as to output the fifth forward speed D 5 .
Sixth Forward Speed
As shown in FIG. 2 , the third clutch C 3 which was operated at the fifth forward speed D 5 is released and the fourth clutch C 4 is operated at the sixth forward speed D 6 .
Accordingly, the rotation speed of the input shaft IS is input to the fifth rotation element N 5 and the seventh rotation element N 7 through the third and fourth variable input paths VIP 3 and VIP 4 by operation of the second and fourth clutches C 2 and C 4 respectively, and the second and third planetary gear sets PG 2 and PG 3 become direct-coupling state. Therefore, the rotation elements of the second and third planetary gear sets PG 2 and PG 3 form a sixth shift line SP 6 , and the sixth shift line SP 6 crosses the vertical line of the sixth rotation element N 6 that is the output element so as to output the sixth forward speed D 6 .
At this time, the rotation speed of the input shaft IS is input to the first planetary gear set PG 1 through the input path IP and the reduced rotation speed is output through the first intermediate output path MOP 1 by operation of the third brake B 3 . However, it does not affect on shifting because the third clutch C 3 is not operated.
Seventh Forward Speed
As shown in FIG. 2 , the second clutch C 2 which was operated at the sixth forward speed D 6 is released and the third clutch C 3 is operated at the seventh forward speed D 7 .
Accordingly, in a state that the rotation speed of the input shaft IS is input to the first rotation element N 1 forming the input path IP, the third rotation element N 3 is operated as the fixed element by operation of the third brake B 3 . Therefore, the rotation elements of the first planetary gear set PG 1 form the second forward speed line T 2 and the reduced rotation speed is output through the first intermediate output path MOP 1 of the second rotation element N 2 .
At this state, the reduced rotation speed is input to the fourth rotation element N 4 through the first variable input path VIP 1 by operation of the third clutch C 3 , and the rotation speed of the input shaft IS is input to the fifth rotation element N 5 through the second variable input path VIP 2 by operation of the fourth clutch C 4 . Therefore, the rotation elements of the second and third planetary gear sets PG 2 and PG 3 form a seventh shift line SP 7 , and the seventh shift line SP 7 crosses the vertical line of the sixth rotation element N 6 that is the output element so as to output the seventh forward speed D 7 .
Eighth Forward Speed
As shown in FIG. 2 , the third clutch C 3 which was operated at the seventh forward speed D 7 is released and the first clutch C 1 is operated at the eighth forward speed D 8 .
Accordingly, in a state that the rotation speed of the input shaft IS is input to the first rotation element N 1 forming the input path IP, the third rotation element N 3 is operated as the fixed element by operation of the third brake B 3 . Therefore, the rotation elements of the first planetary gear set PG 1 form the second forward speed line T 2 and the fourth rotation element N 4 is operated as the fixed element by operation of the first clutch C 1 .
At this state, the rotation speed of the input shaft IS is input to the fifth rotation element N 5 through the second variable input path VIP 2 by operation of the fourth clutch C 4 . Therefore, the rotation elements of the second and third planetary gear sets PG 2 and PG 3 form an eighth shift line SP 8 , and the eighth shift line SP 8 crosses the vertical line of the sixth rotation element N 6 that is the output element so as to output the eighth forward speed D 8 .
Ninth Forward Speed
As shown in FIG. 2 , the third brake B 3 which was operated at the eighth forward speed D 8 is released and the first brake B 1 is operated at the ninth forward speed D 9 .
Accordingly, in a state that the rotation speed of the input shaft IS is input to the first rotation element N 1 forming the input path IP, the second rotation element N 2 is operated as the fixed element by operation of the first brake B 1 . Therefore, the rotation elements of the first planetary gear set PG 1 form the first forward speed line T 1 and the inverse rotation speed is output through the third rotation element N 3 forming the second intermediate output path MOP 2 .
The inverse rotation speed of the second intermediate output path MOP 2 is input to the fourth rotation element N 4 through the first intermediate input path VIP 1 by operation of the first clutch C 1 , and the rotation speed of the input shaft IS is input to the fifth rotation element N 5 by operation of the fourth clutch C 4 . Therefore, the rotation elements of the second and third planetary gear sets PG 2 and PG 3 form a ninth shift line SP 9 , and the ninth shift line SP 9 crosses the vertical line of the sixth rotation element N 6 that is the output element so as to output the ninth forward speed D 9 .
Reverse Speed
As shown in FIG. 2 , the third clutch C 3 and the second and third brakes B 2 and B 3 are operated at the reverse speed REV.
Accordingly, in a state that the rotation speed of the input shaft IS is input to the first rotation element N 1 forming the input path IP, the third rotation element N 3 is operated as the fixed element by operation of the third brake B 3 . Therefore, the rotation elements of the first planetary gear set PG 1 form the second forward speed line T 2 and the reduced rotation speed is output through the first intermediate output path MOP 1 of the second rotation element N 2 .
In a state that the reduced rotation speed is input to the fourth rotation element N 4 through the first variable input path VIP 1 by operation of the third clutch C 3 , the fifth rotation element N 5 is operated as the fixed element by operation of the second brake B 2 . Therefore, the rotation elements of the second and third planetary gear sets PG 2 and PG 3 form a reverse shift line RS, and the reverse shift line RS crosses the vertical line of the sixth rotation element N 6 that is the output element so as to output the reverse speed REV.
As described above, nine forward speeds and one reverse speed are achieved by combining three simple planetary gear sets with four clutches and three brakes and operating three frictional elements at each shift-speed. Therefore, power delivery performance and fuel economy may be improved.
Since the friction members including a plurality of clutches and brakes are dispersedly disposed, formation of hydraulic lines for supplying hydraulic pressure thereto may be simplified and weight balance in an automatic transmission may be enhanced.
For convenience in explanation and accurate definition in the appended claims, the terms upper or lower, front or rear, inside or outside, and etc. are used to describe features of the exemplary embodiments with reference to the positions of such features as displayed in the figures.
The foregoing descriptions of specific exemplary embodiments of the present invention have been presented for purposes of illustration and description. They are not intended to be exhaustive or to limit the invention to the precise forms disclosed, and obviously many modifications and variations are possible in light of the above teachings. The exemplary embodiments were chosen and described in order to explain certain principles of the invention and their practical application, to thereby enable others skilled in the art to make and utilize various exemplary embodiments of the present invention, as well as various alternatives and modifications thereof. It is intended that the scope of the invention be defined by the Claims appended hereto and their equivalents. | A gear train of an automatic transmission for vehicles has the advantages of simplifying structures of the automatic transmission and improving power delivery performance and fuel economy as a consequence of realizing at least nine forward speeds and one reverse speed by combining three simple planetary gear sets with four clutches and three brakes. | 5 |
FIELD OF THE INVENTION
The invention relates to a fastening system for mounting detachable covering components, such as panels on other components such as automotive body parts, having at least one spacer that can be secured on the covering component on one side by a fastener and that is provided with a hook-and-loop-type fastening part on the opposite side. The fastening part is detachably engageable with a corresponding hook-and-loop fastening part secured on the other component.
BACKGROUND OF THE INVENTION
A fastening system of this type conforming to the prior art is disclosed in WO 2009/097950 A1. Such fastening systems serve to secure sheet-type panels in predefinable locations, for example, to conceal unattractive areas with a laminated veneer. They may also be used for thermal and sound insulation. For example, panel-type covering components may be used in automotive engineering to cover large areas of sheet metal parts as automotive body components. Loading doors, for example, may be the body parts, although body floors and roofs may also be involved. In addition to the automotive field, such fastening systems may also be used in railroads, ships and airplanes, where comparable problems must be solved.
The fastening system permits a detachable connection between the covering component and another component. Technical equipment inside the other component, such as cables, air conditioning ducts, electronic control systems, etc., may be readily accessible as needed, by removing the covering component from the other component having the respective technical equipment. The removal is accomplished by disengaging the hook-and-loop fastening parts, i.e., releasing the hook-and-loop fastener connection. In an effort to ensure secure fastening of the covering components, hook-and-loop fasteners today are designed with high holding forces. Although this design ensures the required reliability of the fastening, problems may occur in removing the components because of the high holding forces. In unfavorable cases, this problem may result in detachment of the spacer body from the covering component when the holding forces of the engaged hook-and-loop fastening parts are stronger than the holding force in effect between the fastener of the spacer body and the covering component.
SUMMARY OF THE INVENTION
An object of the present invention is to provide an improved fastening system that will permit reliable removal of the covering components despite the high holding forces in effect on the hook-and-loop fastening parts.
This object is basically achieved according to the invention by a fastening system having a flat mesh that increases the connecting portion between the covering component and spacer and that is attached to at least one edge of the side of the spacer body to be connected to the covering component. In the prior art, only the respective base area of the spacer body is available for an adhesive that is provided as the fastener. The presence of the flat mesh attached to the spacer body at the side then opens up additional possibilities for implementing a secure connection to the other component. Not only does the mesh increase the connecting portion per se, but the mesh structure with its corresponding mesh openings also permits other, more effective, connecting technologies in comparison with an adhesive connection between smooth surfaces. This mesh is therefore suitable for lamination, or foaming in place, in a covering component or for a foam lining, where form-fitting connections are created. In the case of adhesive connections with adhesives based on polyamide or with synthetic rubber adhesives, forming-fitting connections are also achieved due to the adhesive passing through the mesh openings. The hook-and-loop fastener connection can therefore be detached reliably as needed, without any risk of damage to the component to be fastened.
The mesh is preferably attached to all the edges of the rectangular spacer body. The connecting portion is then enlarged toward all sides of the spacer. The dimensions of the mesh are selected especially advantageously, so that the mesh enlarges the size of the connecting portion of the spacer with the covering component to more than twice the area of the spacer body.
The shape of the mesh can have a smooth curvature on its periphery, in particular being round or oval, or the mesh may have an angular shape. In the latter case, the mesh may also be designed to have corner angles, a few of which are open to the outside and a few of which are open to the inside, thus forming a mesh having a plurality of separate arms.
Regardless of the respective shape of the mesh, the spacer body may be situated in the central area of the connecting portion formed by the mesh or outside of this central area.
The actual mesh structure may advantageously be formed by two groups of intersecting mesh bars that are parallel in each group. The groups of mesh bars may intersect one another at right angles, so that rectangular mesh openings are formed.
In a particularly advantageous manner, the mesh may be integrally molded on the spacer body in one piece. The unitary spacer body and mesh may be a homogeneous injection-molded body or may be a plastic part with inserts of textile fibers or fiber glass cloth or metal cloth.
In advantageous embodiments, the spacer body has a protruding planar edging on the side to be connected to the covering component. The edging then is connected to the mesh in a coplanar arrangement. Therefore, in addition to the planar base area of the spacer body, a planar contact surface enlarging this area is also formed for the covering component.
Other objects, advantages and salient features of the present invention will become apparent from the following detailed description, which, taken in conjunction with the annexed drawings, discloses preferred embodiments of the present invention.
BRIEF DESCRIPTION OF THE DRAWINGS
Referring to the drawings which form a part of this disclosure:
FIG. 1 is an exploded perspective view of essential parts of a fastening system according to a first exemplary embodiment of the invention;
FIG. 2 is an exploded perspective view of only the spacer and a respective hook-and-loop fastening part of a fastening system according to a second exemplary embodiment of the invention;
FIG. 3 is a perspective view of only the spacer of a fastening system of a third exemplary embodiment of the invention;
FIGS. 4 to 8 are simplified schematic top plan views of the spacers of fastening systems according to fourth, fifth, sixth, seventh and eighth exemplary embodiments of the invention;
FIG. 9 is a top plan view of a spacer of a fastening system according to a ninth exemplary embodiment of the invention;
FIG. 10 is a front elevational view in section of the spacer of FIG. 9 taken along line X-X in FIG. 9 ;
FIG. 11 is a top plan view of the spacer of FIG. 9 drawn on an enlarged scale in comparison with the FIGS. 9 and 10 , but with the hook-and-loop fastening part removed from the box part of the spacer body; and
FIG. 12 is a bottom plan view of the spacer body of FIG. 11 with the hook-and-loop fastening part removed from the box part of FIG. 11 showing the underside of its backing part.
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 shows the individual components of the fastening system made up of these components as a whole, beginning with a spacer 1 shown at the bottom of FIG. 1 , fastenable to a covering component (not shown) by fastening system. The spacer 1 has a rectangular box part 3 with a frame recess 5 for accommodating, in a flush manner, a first hook-and-loop fastening part 7 . Fastener part 7 has hook elements 11 in the shape of mushroom heads, on a backing layer 9 . These hook elements can engage with corresponding hook elements 11 on a second hook-and-loop fastening part 15 , whose backing layer 13 is fastened to the respective other component 17 , body panel 19 . FIG. 1 shows a flat section of an automotive body panel 19 as an example. As in the prior art, the box part 3 of the spacer 1 may be designed with a different design height to implement the desired different distances between the covering component and the other component 17 .
With the fastening system according to the invention, a flat mesh 21 is the fastener for securing the spacer 1 on the covering component (not shown). This flat mesh is attached to the box part 3 and the side facing the covering component, and increases the connecting portion with the covering component beyond the size of the area of the box part 3 . In the exemplary embodiment in FIG. 1 , the mesh 21 is circular and surrounds the box part 3 such that the box part is situated in the area of the center of the circle. The mesh 21 is formed by two groups of mesh bars 23 and 25 , intersecting one another at or almost at right angles, thereby forming rectangular mesh openings 27 shaped like the mesh bars 23 and 25 (not all of which are labeled in the drawings). The mesh 21 is designed to be relatively fine, so the number of mesh openings 27 may amount to 50 openings or even far more than 50 openings. That mesh structure is especially suitable for connection to the covering component by lamination, or foaming in place or injection in place. Adhesives may also be used. In any case, this mesh structure yields a form-fitting anchoring due to the material or the adhesive permeating the mesh openings 27 . Hot-melt adhesives having a high thermal stability such as polyamide adhesives may also be used. The box part 3 is especially preferably made of an ABS material, in particular PC-ABS (polycarbonate-acrylonitrile-butadiene-styrene material). The entire spacer 1 with the box part 3 and the mesh 21 may be designed as a one-piece injection molded object made of plastic material, e.g., made of a polyamide-6 [nylon-6] material. Instead of a homogeneous injection-molded article, the box part may also be provided with an insert, such as a textile fiber material, glass fiber material or metal cloth.
FIG. 2 illustrates a modified embodiment differing from the first example in that the mesh 21 has a rectangular shape with flattened corners. As in the first exemplary embodiment, the box part 3 is positioned centrally within the connecting portion formed by the mesh 21 . Another difference is that the box part 3 has a greater height than in the first example. Furthermore, the mesh 21 is not directly connected to the box part 3 , but instead the box part 3 has a protruding planar edging 29 on the side connected to the covering component. The entire spacer 1 including the box part 3 , edging 29 and mesh 21 , is designed as a uniform injection-molded body in one piece.
In the exemplary embodiment in FIG. 3 , the only difference in comparison with the example in FIG. 2 is that the mesh 21 is oval-shaped.
To provide a mesh structure that increases the connecting area, the mesh 21 may have various shapes. The box part 3 also need not necessarily be positioned in the central area of the respective mesh 21 , just as the box part 3 need not have a square shape itself (as shown in the figures). Instead, box part 3 could also have a more elongated rectangular shape. FIGS. 4 through 8 illustrate a selection of possible variants of the design of the mesh 21 . FIG. 4 shows a slender oval shape with the box part 3 situated in the central area, in the form of a simplified schematic diagram of the mesh 21 . The example in FIG. 5 differs in comparison with the FIG. 4 example only in the decentralized position of the box part 3 . FIG. 6 , like FIG. 1 , shows a circular mesh 21 having the box part 3 situated in the central area. Finally, FIGS. 7 and 8 show examples in which mesh bars 31 running perpendicular to one another extend from a box part 3 of a square shape situated in the central area of the connecting portion. These mesh bars extend outward from each side of the square, so that the mesh 21 forms a bar cross having corner angles 33 that are open to the outside and corner angles 35 that are open to the inside. In the example shown in FIG. 7 , each bar 31 has the same width. The example in FIG. 8 differs from the FIG. 7 example in that the vertical bars 31 in the figure are narrower than the horizontal bars 31 , and the width of the narrower bars 31 is less than the side length of the box part 3 .
In another embodiment according to FIGS. 9 through 12 , the box part 41 forming the spacer body is in the form of a trough-shaped hollow box. The backing layer 9 of the hook-and-loop fastening part 7 can be secured on the bottom 43 of the hollow box above the mesh 21 without edging. For this purpose, the backing layer 9 has a protruding retaining lug 45 with a button-type extension 47 on the free end. The bottom 43 of the box part 41 has a slot 49 . Box part 41 is open on the side 48 toward which the slot 49 is open, so that the retaining lug 45 can be inserted into the slot 49 . The button-type extension 47 protrudes beyond the edges 50 of the slot 49 and thereby secures the hook-and-loop fastening part 7 on the box part 41 in a form-fitting manner.
While various embodiments have been chosen to illustrate the invention, it will be understood by those skilled in the art that various changes and modifications can be made therein without departing from the scope of the invention as defined in the appended claims. | A fastening system for mounting detachable covering components, like panels, on other components ( 17 ), like carriage parts ( 19 ), has at least one spacer ( 1 ) with a spacer body ( 3 ). One spacer body side can be attached to the covering component. The opposite side has an adhesive closure part ( 7 ) detachably engaged with a corresponding adhesive closure part ( 16 ) attached to the other component ( 17 ). At least on one border of the side of the spacer body ( 3 ) connected to the covering component, a flat mesh ( 21 ) abuts to enlarge the connection area between the covering component and the spacer ( 1 ). | 0 |
CROSS-REFERENCE TO RELATED APPLICATIONS
This application is a continuation of U.S. patent application Ser. No. 10/256,563, filed Sep. 27, 2002, and issued as U.S. Pat. No. 6,858,547, which claims benefit of U.S. Provisional Patent Application Ser. No. 60/388,928, filed Jun. 14, 2002. Each of the aforementioned related patent applications is herein incorporated by reference.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates generally to forming gate dielectric in field effect transistors, and particularly to forming metal oxide/metal silicate gate dielectric films using chemical vapor deposition.
2. Description of the Related Art
The present invention is especially useful in forming complementary metal oxide semiconductor (CMOS) integrated-circuit devices and will be described in that context. Other applications will also be mentioned. CMOS technology has enabled the microelectronic industry to simultaneously meet several technological requirements to fuel market expansion. This has been accomplished largely by a calculated reduction (scaling) of the dimensions of the field-effect transistor (FET). FIG. 1 illustrates portions of a cross sectional view of a field effect transistor (FET) pair in a typical complimentary metal oxide semiconductor (CMOS) device. Device 100 comprises a silicon wafer 155 doped with a p-type material, a p-type epitaxial silicon layer 165 on wafer 155 , a p-type well region 120 and an n-type well region 150 defined in epitaxial layer 165 , an n-type transistor (NMOS FET) 110 defined in p-well 120 and a p-type transistor (PMOS FET) 140 defined in n-well 150 . Region 180 electrically isolates NMOS 110 and PMOS 140 transistors and region 160 electrically isolates the pair of transistors 110 and 140 from other semiconductor devices on substrate 155 .
NMOS transistor 110 comprises a gate region 122 , a source region 114 and a drain region 116 . The source and drain regions are n-type regions on opposite sides of gate region 122 . Channel region 118 is interposed between source region 114 and drain region 116 . A gate dielectric layer 112 separates channel region 118 and gate region 122 . Gate dielectric 112 electrically insulates gate region 122 from channel region 118 . The gate region comprises a conductor material, typically doped polycrystalline silicon (polysilicon) or amorphous silicon. The dopant may be an n-type dopant such as a phosphorus or a p-type dopant such as boron. When an appropriate voltage is applied between p-type silicon wafer 155 and gate region 122 , electrons from p-well 120 move into region 118 directly below dielectric 112 thereby creating an n-type channel 118 . A voltage applied between source 114 and drain 116 causes current to flow between source 114 and drain 116 .
PMOS transistor 140 comprises a gate region 152 , a source region 144 and a drain region 146 . The source and drain regions are p-type regions on opposite sides of gate region 152 . Channel region 148 is interposed between source region 144 and drain region 146 . A gate dielectric 142 separates channel region 148 and gate region 152 . Dielectric 142 electrically insulates gate region 152 from channel region 148 . The gate region comprises a conductor material typically doped polysilicon or amorphous silicon. Again, the dopant may be an n-type or p-type material. When an appropriate voltage is applied between p-type silicon wafer 155 and gate region 152 , holes from n-well 150 move into region 148 directly below dielectric layer 142 thereby creating a p-type channel 148 . A voltage applied between source 144 and drain 146 causes current to flow between source 144 and drain 146 .
With the rapid shrinking of the transistor feature size, the gate dielectric thickness has also decreased. For several decades, silicon dioxide has been the material of choice for the gate dielectric layer. Silicon dioxide offers a stable high-quality Si—SiO 2 interface and superior electrical isolation properties.
However, as the dimensions of the transistor continue to decrease, the continued use of silicon dioxide as a dielectric gate material is problematic. The fundamental problem is the need to keep the capacitance of the gate high while the area of the gate is shrinking faster than the thickness of the gate dielectric. The capacitance C of the gate is given by C=kE 0 A/d, wherein A is the area of the gate, d is the thickness of the dielectric layer, k is the dielectric constant, and E 0 is the permittivity of free space. In order to ensure higher gate oxide capacitance, the silicon dioxide layer thickness proportionately has been decreased to less than 2 nanometers as the area of the gate has been decreasing. However, future generations will likely require a further reduction to below 1.0 nanometer. The primary issue is that as thickness decreases, leakage current increases. This leakage in current is due primarily to the ability of the electrons to go through the thinner SiO 2 dielectric layer. In an example, current density for a 1.5 nanometer thick SiO 2 layer at 1 V is 1 A/cm 2 ; however, as the SiO 2 thickness decreases to 1 nanometer, the leakage-current density approaches 100 A/cm 2 at the same operating voltage.
Consequently, there is a need for an alternative gate dielectric material that can be used in a large enough physical thickness to reduce current leakage density and still provide a high gate capacitance. In order to achieve this, the alternative gate dielectric material must have a dielectric constant that is higher than that of silicon dioxide. Typically, the thickness of such an alternative dielectric material layer is expressed in terms of the equivalent oxide thickness (EOT). Thus, the equivalent oxide thickness (EOT) of an alternative dielectric layer in a particular capacitor is the thickness that the alternative dielectric layer would have if its dielectric constant were that of silicon dioxide.
Another consideration in selecting an alternative dielectric material is the mobility of charge carries in the transistor channel. The material selected for the dielectric film affects the mobility of the carriers in the transistor channel, thereby affecting overall transistor performance. It is desirable to find an alternative dielectric material for which the mobility of carriers in the transistor channel is equivalent to or higher than that for silicon dioxide gate dielectric films. For future generation transistors, a peak mobility of 400 cm 2 /Vs or greater is desirable.
SUMMARY OF THE INVENTION
The present invention comprises forming a metal oxide, metal silicate, or combination metal oxide-metal silicate dielectric stack on a semiconductor wafer.
In one embodiment, the method comprises pre-treating the semiconductor wafer, e.g., to remove oxide, with hydrofluoric acid to form an HF-last surface and then pre-treating the HF-last surface with ozonated water for a specified time period. After pre-treating, a dielectric stack is formed on the pre-treated surface using a chemical vapor deposition process. A flow of NH 3 is then provided in a process zone surrounding the semiconductor wafer. In one embodiment, after providing the NH 3 flow, a polycrystalline or amorphous silicon gate is formed over the dielectric stack using a LPCVD process.
In another embodiment, the method of forming a dielectric stack on a semiconductor wafer comprises pre-treating the semiconductor wafer with hydrofluoric acid to form an HF-last surface, pre-treating the HF-last surface with NH 3 , forming the dielectric stack on the pre-treated surface, and providing a flow of N 2 in a process zone surrounding the semiconductor wafer after forming the dielectric stack.
In yet another embodiment, the method of forming a dielectric stack on a semiconductor wafer comprises pre-treating the semiconductor wafer with hydrofluoric acid to form an HF-last surface, pre-treating the HF-last surface using an in-situ steam generation process, forming the dielectric stack on the pre-treated surface, and annealing the semiconductor wafer after forming the dielectric stack. The in-situ steam generation process comprises providing an inert gas flow in a process zone surrounding the HF-last surface, reacting hydrogen with an oxidizer in the process zone surrounding the HF-last surface for a very short duration, and providing an inert gas flow in the process zone after the reacting step. Preferably, the dielectric stack comprises layers of hafnium oxide, hafnium silicate layers, or a combination thereof formed using a MOCVD process.
BRIEF DESCRIPTION OF THE DRAWINGS
So that the manner in which the above recited features of the present invention, and other features contemplated and claimed herein, are attained and can be understood in detail, a more particular description of the invention, briefly summarized above, may be had by reference to the embodiments which are illustrated in the appended drawings. It is to be noted, however, that the appended drawings illustrate only typical embodiments of this invention and are therefore not to be considered limiting of its scope, for the invention may admit to other equally effective embodiments.
Additional objects and features of the invention will be more readily apparent from the following detailed description and appended claims when taken in conjunction with the drawings, in which:
FIG. 1 illustrates portions of a cross sectional view of field effect transistor (FET) pair in a typical complimentary metal oxide semiconductor (CMOS) device.
FIG. 2 illustrates a cross-sectional view of a portion of a transistor having a dielectric stack.
FIG. 3 illustrates the processing steps used to form a hafnium oxide and hafnium silicate gate dielectric stack.
FIG. 4 illustrates the general chemical structure for the hafnium oxide precursors of the form Hf(NRR′) 4 .
FIG. 5 illustrates the chemical structure of the TDEAH precursor.
FIG. 6 illustrates the general chemical structure for precursors of the form SiR 1 R 2 R 3 R 4 .
FIG. 7 illustrates the chemical structure of the TDMAS precursor.
FIG. 8 illustrates the processing steps used to form a hafnium oxide and hafnium silicate gate dielectric stack.
FIG. 9 illustrates the processing steps that may be used for forming the dielectric stack using a flash in-situ steam generation (ISSG) pre-treatment process.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
FIG. 2 illustrates a cross-sectional view of a portion of a field effect (FET) 200 transistor having a dielectric stack in accordance with an embodiment of the invention. FET 200 comprises a source 250 , a drain 240 , a gate 210 , a dielectric stack 260 and a channel 270 interposed between source 250 and drain 240 . Preferably, the transistor is formed on a silicon wafer and the gate is made of polycrystalline or amorphous silicon. In a PMOS FET, source 250 and drain 240 comprise a p-type silicon and in an NMOS FET, source 250 and drain 240 comprise an n-type silicon.
In one embodiment, dielectric stack 260 comprises at least two layers, where each layer comprises either a metal oxide layer or a metal silicate layer. In the embodiment shown, there is a metal oxide layer 230 and a metal silicate layer 220 . The stack is formed using any metal that is capable of forming a high-k layer, e.g., HfO 2 , ZrO 2 . A high-k layer comprises a dielectric material having a dielectric constant greater than 4. Preferably, metal oxide layer 230 and metal silicate layer 220 comprise any metal that can form amino precursors. More preferably, metal oxide layer 230 comprises hafnium oxide and the metal silicate layer 220 comprises hafnium silicate. In one embodiment, the hafnium oxide layer thickness is about 3 nanometers and the hafnium silicate layer thickness is about 1 nanometer. Such a dielectric stack has an EOT of about 1.12 nanometers. In another embodiment, the hafnium oxide layer thickness is about 4 nanometers and hafnium silicate layer thickness is about 1.5 nanometers. Such a dielectric stack has an EOT of about 1.61 nanometers. An EOT of 1.61 nanometers provides the desired peak mobility of 400 cm 2 /Vs. In yet another embodiment, the dielectric stack thickness is selected to provide both the desired capacitance corresponding to 1.12 nanometers EOT and the desired peak mobility of 400 cm 2 /Vs.
EXAMPLE 1
FIG. 3 illustrates the processing steps used in accordance with the invention to form a hafnium oxide, hafnium silicate, or combination thereof gate dielectric stack having an EOT of about 1.12 nanometers. At step 310 , an HF-last surface is formed on a semiconductor wafer by introducing a dilute hydrofluoric acid solution onto the wafer surface for a specified time period. In one embodiment, the wafer is immersed in a hydrofluoric acid bath for a time period of about 2 minutes to about 15 minutes. More preferably, the wafer is immersed in a 2% hydrofluoric acid bath for about 2 minutes.
Next, the wafer is placed in a thermal chamber for pre-treating at 1 to 100 Torr. A step 320 , NH 3 is introduced onto the HF-last surface for a specified time period and at a specified temperature. Step 320 adds a nitride “coating” or “layer” that aids in preventing the dopant of the gate layer ( 210 in FIG. 2 ) from diffusing into the channel ( 270 in FIG. 2 ). Preferably, the specified time period is in the range of about 5 seconds to about 120 seconds and the specified temperature is in the range of about 400° C. to about 1,100° C. More preferably, the specified time period is about 30 seconds and the specified temperature is about 600° C. at 30 Torr.
The wafer is then transported from the thermal chamber to a deposition chamber. A hafnium oxide or hafnium silicate layer is then formed at step 330 using deposition processes such as MOCVD, LPCVD, PECVD, VPE, ALD or PVD. Preferably, the hafnium oxide or hafnium silicate layer is formed using a MOCVD process.
If a hafnium oxide layer is preferred, O 2 , N 2 and a hafnium oxide precursor are introduced onto the wafer surface. The hafnium oxide precursor is any precursor of the alkylamido or alkylamino ligand group. In one embodiment, the hafnium oxide precursor is selected from a group comprising amino or amido precursors of the form Hf(NRR′) 4 where
R=H, CH 3 , C 2 H 5 , C 3 H 7 , alkyl, and aryl and R′=H, CH 3 , C 2 H 5 , C 3 H 7 , alkyl, and aryl.
FIG. 4 illustrates the general chemical structure for the hafnium oxide precursors of the form Hf(NRR′) 4 . Preferably, the hafnium oxide precursor is tetrakis(diethylamido)hafnium (TDEAH). FIG. 5 illustrates the chemical structure of the TDEAH precursor.
TDEAH is flowed onto the wafer surface at a rate in the range of about 1 mg/min to about 50 mg/min. Preferably, TDEAH is flowed onto the wafer surface at a rate of about 7 mg/min. O 2 is flowed onto the wafer surface at a rate in the range of about 30 sccm to about 3,000 sccm. Preferably, O 2 is flowed onto the wafer surface at a rate of about 1,000 sccm. N 2 is flowed onto the wafer surface at a rate in the range of about 30 sccm to about 3,000 sccm. Preferably, N 2 is flowed onto the wafer surface at a rate of about 1,500 sccm. O 2 , N 2 and TDEAH are introduced onto the wafer surface either simultaneously or sequentially or a combination thereof.
The hafnium oxide layer is formed at temperatures in the range of about 225° C. to about 700° C. Preferably, the hafnium oxide layer is formed at about 485° C. The pressure in the deposition chamber is in the range of about 1.5 Torr to about 8 Torr. Preferably, the pressure is about 4 Torr. The hafnium oxide layer formed has a thickness in the range of about 5 Å to about 50 Å. Preferably, the hafnium oxide layer formed has a thickness of about 30 Å.
In one embodiment, the wafer is transported to a second chamber after forming the hafnium oxide layer in a first chamber. The process conditions of the first chamber are then adjusted for forming the hafnium silicate layer. The wafer is then transported back to the first chamber for forming the second layer. Alternatively, the wafer can remain in the same chamber for sequential deposition of the second layer. The choice of whether to use single- or multiple-chamber deposition depends on a number of factors including the deposition process chosen for each layer (e.g., MOCVD for one layer and ALD for another or MOCVD for both layers), the capabilities or limitations of the system (transfer speed between chambers, temperature ramping capabilities), whether the wafers are being processed in a development or production environment, and/or whether an anneal process is performed between the deposition of the two dielectric layers.
Alternatively, the hafnium silicate layer may be formed at step 330 using deposition processes such as MOCVD, LPCVD, PECVD, VPE, ALD or PVD. Preferably, the hafnium silicate layer is formed using a MOCVD process, where O 2 , N 2 , and hafnium silicate precursors are introduced onto the wafer surface and the process temperature is about 480° C. to about 600° C. and the pressure is adjusted to about 4 Torr.
The hafnium silicate precursors are precursors of the alkylamido or alkylamino ligand group. The hafnium silicate precursors are selected from precursors of the form Hf(NRR′) 4 and SiR 1 R 2 R 3 R 4 where
R=H, CH 3 , C 2 H 5 , C 3 H 7 , alkyl, and aryl;
R′=H, CH 3 , C 2 H 5 , C 3 H 7 , alkyl, and aryl;
R 1 =H, NH 2 , N(CH 3 ) 2 , N(C 2 H 5 ) 2 , N(C 3 H 7 ) 2 , NCO, alkoxy, amino, alkyl and aryl;
R 2 =H, NH 2 , N(CH 3 ) 2 , N(C 2 H 5 ) 2 , N(C 3 H 7 ) 2 , NCO, alkoxy, amino, alkyl and aryl;
R 3 =H, NH 2 , N(CH 3 ) 2 , N(C 2 H 5 ) 2 , N(C 3 H 7 ) 2 , NCO, alkoxy, amino, alkyl and aryl; and
R 4 =H, NH 2 , N(CH 3 ) 2 , N(C 2 H 5 ) 2 , N(C 3 H 7 ) 2 , NCO, alkoxy, amino, alkyl and aryl.
The general chemical structure for the precursors of the form Hf(NRR′) 4 is shown in FIG. 4 . FIG. 6 illustrates the general chemical structure for precursors of the form SiR 1 R 2 R 3 R 4 . Preferably, the hafnium silicate precursors are tetrakis(diethylamido)hafnium (TDEAH) and tetrakis(dimethylamido)silicon (TDMAS). FIG. 7 illustrates the chemical structure of the TDMAS precursor. The chemical structure for the TDEAH precursor is shown in FIG. 5 .
TDEAH is flowed onto the wafer surface at a rate in the range of about 1 mg/min to about 50 mg/min. Preferably, TDEAH is flowed onto the wafer surface at a rate of about 6 mg/min. TDMAS is flowed onto the wafer surface at a rate of about 1 mg/min to about 50 mg/min. Preferably, TDMAS is flowed at a rate of 50 mg/min. O 2 is flowed onto the wafer surface at a rate of about 30 sccm to about 1,000 sccm, preferably about 1,000 sccm, and N 2 is flowed onto the wafer surface at a rate of about 30 sccm to about 3,000 sccm, preferably about 1,500 sccm. O 2 , N 2 , TDEAH and TDMAS are introduced onto the wafer surface either simultaneously or sequentially or a combination thereof.
The hafnium silicate layer is formed at temperatures in the range of about 325° C. to about 700° C. and pressure is in the range of about 1.5 Torr to about 8 Torr. Preferably, the hafnium silicate layer is formed at about 600° C. at a pressure of about 4 Torr. The hafnium silicate layer thickness is about 5-20 Å, preferably 10 Å. The SiO 2 concentration of the hafnium silicate layer is from about 5 mol % to about 80 mol %. More preferably, the SiO 2 concentration is about 10 mol %.
Thus, either a hafnium oxide or hafnium silicate layer can be formed at steps 330 and 340 . Should, for example, hafnium oxide be used to form both layers, it is preferred that the hafnium oxide layers have differing compositions or stoichiometry, for example, a first layer comprised of HfO 2 and a second layer comprised of Hf 2 O 3 . Similarly, should both layers be comprised of hafnium silicate, it is preferable that the hafnium silicate layers have differing compositions and/or stoichiometry.
After forming the hafnium silicate layer or hafnium oxide layer at step 340 , the wafer is transported back to the thermal chamber for further processing at 1 to 100 Torr. At step 350 , N 2 is introduced onto the wafer surface for a specified time period and at a specified temperature. Preferably, the specified time period is in the range of about 5 seconds to about 60 seconds at temperatures in the range of about 400° C. to about 1,100° C. More preferably, N 2 is introduced onto the wafer surface for about 60 seconds at a temperature of about 800° C. at 10 Torr.
In one embodiment, a gate electrode is next formed at step 360 on the hafnium oxide or hafnium silicate layer. The gate electrode layer may be made of polycrystalline or amorphous silicon and is formed using a chemical vapor deposition process such as MOCVD, LPCVD, PECVD, VPE, ALD or PVD. In one embodiment, the gate electrode is formed using an LPCVD process where silane or disilane is flowed onto the wafer at temperatures in the range of about 400° C. to about 900° C. Preferably, the gate electrode is formed at a temperature of about 570° C.
In some embodiments, a nitride layer may be formed on the hafnium oxide or hafnium silicate layer before formation of the polysilicon gate (i.e., to form a layer between the hafnium silicate layer 220 and the polysilicon gate 210 , see FIG. 2 ). This embodiment is illustrated at step 850 of FIG. 8 . Alternatively, for example, a nitride layer may be formed between the channel 270 and the hafnium oxide layer 220 . This embodiment is shown at step 320 of FIG. 3 . The nitride layer prevents dopant diffusion from the gate electrode into the silicon channel. In such embodiments, the polysilicon gate electrode 210 is implanted with dopants such as boron and phosphorus; and the structure is then annealed at ˜1000° C. for activation and distribution of the dopant in the polysilicon layer. It is undesirable for dopant to diffuse from the gate electrode layer 210 into the silicon channel 270 . In small doses, such diffusion can affect threshold voltages, and in larger doses such diffusion can increase leakage currents. Either case drastically affects transistor performance.
EXAMPLE 2
FIG. 8 illustrates the processing steps used in accordance with the invention to form a hafnium oxide and hafnium silicate gate dielectric stack having a peak mobility of about 400 cm 2 /Vs. At step 810 , an HF-last surface is formed on a semiconductor wafer by introducing a dilute hydrofluoric acid solution onto the wafer surface for a specified time period. In one embodiment, the wafer is immersed in a hydrofluoric acid bath for a time period of about 1 minute to about 15 minutes. More preferably, the wafer is immersed in a 2% hydrofluoric acid bath for about 2 minutes.
Next, at step 820 , the HF-last surface is exposed to ozonated water by, for example, immersing the wafer in an ozonated water bath. Preferably, the ozone concentration in the ozonated water is in the range of about 10 ppm to about 30 ppm. Preferably, the ozone concentration in the water is about 20 ppm. Preferably, the HF-last surface is exposed to the ozonated water for about 5 minutes to about 15 minutes. More preferably, the HF-last surface is exposed to the ozonated water for about 10 minutes.
The wafer is next placed in a deposition chamber. A hafnium oxide layer is then formed at step 830 using deposition processes such as MOCVD, LPCVD, PECVD, VPE, ALD or PVD. Preferably, the hafnium oxide layer is formed using a MOCVD process.
O 2 , N 2 and a hafnium oxide precursor are introduced onto the wafer surface. The hafnium oxide precursor is any precursor of the alkylamido or alkylamino ligand group. In one embodiment, the hafnium oxide precursor is selected from a group comprising amino or amido precursors of the form Hf(NRR′) 4 where
R=H, CH 3 , C 2 H 5 , C 3 H 7 , alkyl, and aryl and R′=H, CH 3 , C 2 H 5 , C 3 H 7 , alkyl, and aryl.
FIG. 4 illustrates the general chemical structure for the hafnium oxide precursors of the form Hf(NRR′) 4 . Preferably, the hafnium oxide precursor is tetrakis(diethylamido)hafnium (TDEAH). FIG. 5 illustrates the chemical structure of the TDEAH precursor.
TDEAH is flowed onto the wafer surface at a rate of about 1 mg/min to about 50 mg/min, preferably about 7 mg/min, O 2 is flowed onto the wafer surface from about 30 sccm to about 3,000 sccm, preferably 30 sccm, and N 2 is flowed onto the wafer surface at a rate of about 30 scorn to about 3,000 sccm, preferably about 1500 sccm. O 2 , N 2 and TDEAH are introduced onto the wafer surface either simultaneously or sequentially or a combination thereof.
The hafnium oxide layer is formed at temperatures in the range of about 225° C. to about 700° C., preferably, at about 485° C. The pressure in the deposition chamber is in the range of about 3 Torr to about 8 Torr, preferably about 4 Torr. Preferably, the hafnium oxide layer formed has a thickness of about 2-5 nanometers, and preferably about 4 nanometers.
After forming the hafnium oxide layer, the wafer is transported from the deposition chamber another chamber. For example, the chamber may be an anneal chamber, a cool-down chamber or a loadlock chamber. Preferably, an anneal step is performed between deposition of the hafnium oxide layer and the hafnium silicate layer. Once the wafer is transferred, the temperature and pressure in the first deposition chamber are adjusted for forming the hafnium silicate layer. For an MOCVD process, the temperature is adjusted to about 600° C. and the pressure is adjusted to about 4 Torr. The wafer is then transported from the cool-down chamber to the deposition chamber. A hafnium silicate layer is then formed at step 840 using deposition processes such as MOCVD, LPCVD, PECVD, VPE, ALD or PVD. In another embodiment, the wafer is not transported to another chamber after forming the hafnium oxide layer, but the wafer remains in the deposition chamber while the process conditions of the deposition chamber are adjusted for forming the hafnium silicate layer. In this case, ramping the temperature from the processing temperature of the hafnium oxide processing conditions to the temperature of the hafnium silicate processing conditions provides an anneal-like environment and a separate anneal step may be eliminated.
Preferably, the hafnium silicate layer is formed using a MOCVD process. O 2 , N 2 , and hafnium silicate precursors are introduced onto the wafer surface. The hafnium silicate precursors are precursors of the alkylamido or alkylamino ligand group. The hafnium silicate precursors are selected from precursors of the form Hf(NRR′) 4 and SiR 1 R 2 R 3 R 4 where
R=H, CH 3 , C 2 H 5 , C 3 H 7 , alkyl, and aryl;
R′=H, CH 3 , C 2 H 5 , C 3 H 7 , alkyl, and aryl;
R 1 =H, NH 2 , N(CH 3 ) 2 , N(C 2 H 5 ) 2 , N(C 3 H 7 ) 2 , NCO, alkoxy, amino, alkyl and aryl;
R 2 =H, NH 2 , N(CH 3 ) 2 , N(C 2 H 5 ) 2 , N(C 3 H 7 ) 2 , NCO, alkoxy, amino, alkyl and aryl;
R 3 =H, NH 2 , N(CH 3 ) 2 , N(C 2 H 5 ) 2 , N(C 3 H 7 ) 2 , NCO, alkoxy, amino, alkyl and aryl; and
R 4 =H, NH 2 , N(CH 3 ) 2 , N(C 2 H 5 ) 2 , N(C 3 H 7 ) 2 , NCO, alkoxy, amino, alkyl and aryl.
The general chemical structure for the precursors of the form Hf(NRR′) 4 is shown in FIG. 4 . FIG. 6 illustrates the general chemical structure for precursors of the form SiR 1 R 2 R 3 R 4 . Preferably, the hafnium silicate precursors are tetrakis(diethylamido)hafnium (TDEAH) and tetrakis(dimethylamido)silicon (TDMAS). FIG. 7 illustrates the chemical structure of the TDMAS precursor. The chemical structure for the TDEAH precursor is shown in FIG. 5 .
TDEAH is flowed onto the wafer surface at a rate of about 1 mg/min to about 50 mg/min, preferably about 6 mg/min, TDMAS is flowed onto the wafer surface at a rate of about 1 mg/min to about 50 mg/min, preferably about 10 mg/min, O 2 is flowed onto the wafer surface at a rate of about 30 sccm to about 3,000 sccm, preferably about 1,000 sccm, and N 2 is flowed onto the wafer surface at a rate of about 30 sccm to about 3,000 sccm, preferably about 1,500 sccm. O 2 , N 2 , TDEAH and TDMAS are introduced onto the wafer surface either simultaneously or sequentially or a combination thereof.
The hafnium silicate layer is formed at temperatures in the range of about 325° C. to about 700° C. and at pressure in the range of about 3 Torr to about 8 Torr. Preferably, the hafnium silicate layer is formed at about 600° C. at a pressure of about 4 Torr. The hafnium silicate layer thickness is from 5 to 20 Å, preferably about 1.5 nanometers. The SiO 2 concentration of the layer is about 5-80 mol %, preferably about 45 mol % to about 50 mol %. More preferably, the SiO 2 concentration is about 50 mol %.
After forming the hafnium silicate layer, the wafer is transported from the deposition chamber to the thermal chamber for further processing. At step 850 NH 3 is then introduced onto the wafer surface at 1 to 100 Torr for a specified time period and a specified temperature. Preferably, the specified time period is in the range of about 5 seconds to about 60 seconds. More preferably, the specified time period is about 60 seconds. Preferably, the specified temperature is in the range of about 400° C. to about 1,100° C. More preferably, the specified temperature is about 700° C. at 30 Torr.
In one embodiment, a polycrystalline-Si or amorphous-Si gate electrode is next formed at step 860 on the hafnium silicate layer. The gate electrode layer is formed using a chemical vapor deposition process such as MOCVD, LPCVD, PECVD, VPE, ALD or PVD. In one embodiment, the gate electrode is formed using an LPCVD process where silane or disilane is flowed onto the wafer at temperatures in the range of about 400° C. to about 900° C. Preferably, the gate electrode is formed at a temperature of about 550° C. As described supra, to avoid undesired dopant diffusion from the gate electrode into the silicon channel, the wafer may be treated with NH 3 (step 850 of FIG. 8 ) after deposition of the dielectric layer 220 and before deposition of the polysilicon gate 210 (layers shown in FIG. 3 ). Such a treatment forms a nitride coating or layer that prevents dopant diffusion. Alternately, a nitride layer may be formed between the dielectric layer 230 and the silicon channel 270 by treating the wafer with NH 3 ( FIG. 3 , step 330 ) after formation of the HF-last.
As described previously, as an alternative to forming first a hafnium oxide layer then forming a hafnium silicate layer, two hafnium oxide layers may be used or two hafnium silicate layers may be used, or first a hafnium silicate layer followed by a hafnium oxide layer may be used. Optionally, a third layer may be formed over the second layer as just described. Such a third layer would comprise hafnium silicate.
Gate Formation using a Flash In-Situ Steam Generation (ISSG) Process
In the flash in-situ steam generation (ISSG) process in accordance with the invention, the reactants, hydrogen and an oxidizer, are introduced onto an HF-last wafer surface for a very short duration to form hydroxyl groups and water vapor in the thermal chamber The hydroxyl groups then bond to the HF-last surface, thereby enhancing high-k nucleation. In accordance with the invention, the growth of interfacial SiO 2 between the silicon channel and the hafnium oxide layer is minimized due to a very short flash in-situ steam generation process and by introducing inert gases before and after the flash ISSG process.
FIG. 9 illustrates the processing steps that may be used in accordance with the invention for forming the dielectric stack using a flash in-situ steam generation (ISSG) pre-treatment process. At step 910 , an HF-last surface is formed on a semiconductor wafer by introducing a dilute hydrofluoric acid solution onto the wafer surface for a specified time period. In one embodiment, the wafer is immersed in a hydrofluoric acid bath for a time period of about 1 minute to about 15 minutes. More preferably, the wafer is immersed in a 2% hydrofluoric acid bath for about 2 minutes.
After the HF-last processing, the wafer is placed in a thermal chamber. The HF-last surface is then pre-treated using a flash ISSG process. First, at step 920 , an inert gas such as helium or nitrogen is introduced into the chamber for a specified time period. Then, at step 930 , the reactants, hydrogen and an oxidizer such as O 2 or N 2 O, are introduced into the chamber for a very short duration. The flow of reactants is then stopped at step 940 while the inert gas continues to flow onto the wafer surface at step 950 . Table 1 provides some illustrative temperatures, flow rates and reactant flow times for a flash ISSG process.
TABLE 1
Reactant
Temp.
Oxidizer
Flow
(° C.)
H 2 (sccm)
(sccm)
He (sccm)
Time(s)
Example 1
750
8
2,980 (O 2 )
2,980
6
Example 2
750
15
2,980 (N 2 O)
2,980
6
Example 3
750
15
2,980 (O 2 )
2,980
6
Example 4
800
5
1,000 (O 2 )
0
3
Example 5
800
5
1,000 (N 2 O)
0
3
After the pre-treating, the wafer is transported to a deposition chamber. A metal oxide and a metal silicate layer are then formed on the pre-treated surface. Preferably, any metal that forms amino precursors, including alkoxides or halides, may be used to form the metal oxide and metal silicate layers. In one embodiment, hafnium oxide and hafnium silicate layers are formed at steps 960 and 970 using the processes described earlier in reference to FIGS. 3 and 8 . Table 2 provides illustrative parameters for forming the hafnium oxide and hafnium silicate layers.
TABLE 2
Pres-
Hf
Si
O 2
N 2
Temp.
sure
(mg/min)
(mg/min)
(sccm)
(sccm)
(° C.)
(Torr)
Example 6
7
0
1,000
1,500
485
4
Example 7
6
50
1,750
750
425
3
Example 8
6
50
1,750
750
525
5.5
Example 9
6
50
1,750
750
575
8
After forming the metal oxide and metal silicate layers, the wafer is transported from the deposition chamber to the thermal chamber for post-deposition processing. In one embodiment, the post-deposition processing comprises the post-treatment processes described earlier in reference to FIGS. 3 and 8 . In another embodiment, the post-deposition processing comprises annealing the wafer surface at step 980 in a thermal or plasma environment using H 2 , O 2 , N 2 O, NO, NH 3 , O 3 , N 2 , He or a combination thereof.
In one embodiment, a polycrystalline-Si or amorphous-Si gate electrode is next formed at step 990 after post-deposition processing. The gate electrode layer is formed using a deposition process such as MOCVD, LPCVD, PECVD, VPE, ALD or PVD. In one embodiment, the gate electrode is formed using an LPCVD process where silane or disilane is flowed onto the wafer at temperatures in the range of about 400° C. to about 900° C. Preferably, the gate electrode is formed at a temperature of about 550° C. To avoid undesired dopant diffusion, a nitride layer may be formed between the dielectric layer 220 and the polysilicon gate 210 prior to formation of the polysilicon gate. Alternately, a nitride layer may be formed between the dielectric layer 230 and the silicon channel 260 .
Various modifications may occur to those skilled in the art without departing from the true spirit and scope of the invention as defined by the appended claims. For example, although the specific embodiments are described using a hafnium oxide and hafnium silicate dielectric gate stack, those skilled in the art will appreciate that the dielectric stack may be formed using any metal that is capable of forming films with the desired capacitance and mobility. Additionally, although the specific embodiments use metal oxide and metal silicate films, other film compositions that provide the desired capacitance and mobility may also be used to form the dielectric stack.
While the foregoing is directed to embodiments of the present invention, other and further embodiments of the invention may be devised without departing from the basic scope thereof, and the scope thereof is determined by the claims that follow. | A method of forming a dielectric stack on a pre-treated surface. The method comprises pre-cleaning a semiconductor wafer to remove native oxide, such as by applying hydroflouric acid to form an HF-last surface, pre-treating the HF-last surface with ozonated deionized water, forming a dielectric stack on the pre-treated surface and providing a flow of NH 3 in a process zone surrounding the wafer. Alternately, the method includes pre-treating the HF-last surface with NH 3 , forming the stack after the pre-treating, and providing a flow of N 2 in a process zone surrounding the wafer after the forming. The method also includes pre-treating the HF-last surface using an in-situ steam generation process, forming the stack on the pre-treated surface, and annealing the wafer after the forming. The pre-treating includes providing an inert gas flow in a process zone surrounding the HF-last surface, reacting hydrogen with an oxidizer in the process zone for a very short duration, and providing an inert gas flew in the process zone after the reacting. | 7 |
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