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BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to improved ionizing radiation sensitive materials which are useful as electron beam resists and information recording media.
2. Description of the Prior Art
It is well-known that electron beam irradiation will cause crosslinking of certain polymers. An article by Herbert S. Cole et al entitled "Electron Sensitive Resists Derived from Vinylether--Maleic Anhydride Copolymers" in the IEEE Transactions on Electron Devices, July 1975, p. 417-420 and U.S. Pat. No. 3,703,402 describes a series of such materials made of octadecylvinyl ether and maleic anhydride copolymer half esterified with, among others allyl or propargyl alcohol or hydroxyalkyl acrylate. The authors state that the most efficient radiation induced crosslinking reactions are activated through the presence of an unsaturated terminal group in the resist, and, accordingly, there is a direct association between increased sensitivity and terminal unsaturation. Their experimental results indicated that reduction or elimination of terminal unsaturation caused a drastic decrease in the sensitivity of the resist polymer, and that to require a radiation dose no greater than 5×10 -7 C/cm 2 an unsaturated half ester is required and that the unsaturation must be terminal unsaturation.
Contrary to the teaching of Cole, it has also been discovered that in U.S. Pat. No. 4,375,398 that resist compositions equally as sensitive can be obtained with a copolymer that has the terminal unsaturation drastically reduced. It was further found that the contrast of such resists improves appreciably, which feature provides a resolution capability of less than 0.5 micrometer. This increased contrast is achieved with resists made by reacting an alkylvinyl ether-maleic anhydride copolymer with a hydroxyalkyl acrylate such as hydroxyethyl acrylate, hydroxyethyl methacrylate, 3-hydroxypropyl acrylate, 3-hydroxypropylmethacrylate, 4-hydroxybutyl acrylate, 4-hydroxybutyl methacrylate or allyl or propargyl alcohol or pentaerythritol triacrylate and an N-hydroxyalkyl amide or an N-aminoalkyl amide to form the novel half-ester copolymer.
It is therefore the object of this invention to obtain increase in sensitive while not sacrificing the increased contrast that was obtained subsequent to the Cole invention.
SUMMARY OF THE INVENTION
The present invention is concerned with a high sensitivity, high contrast electron beam resist material comprising a metal complex of the mixed half-ester or half amide product of the reaction of an N-hydroxy or N-aminoalkyl amide and a hydroxyalkyl terminally unsaturated copolymer with an alkylvinyl ether-maleic anhydride copolymer. In the preferred form of the invention an N-hydroxyalkyl cyclic amide, such as hydroxyethyl pyrrolidone, and a hydroxyalkyl acrylate, such as hydroxyethyl acrylate, are reacted with a long chain alkylvinyl ether-maleic anhydride copolymer, preferably having about 10-20 carbon atoms in the alkyl chain, such as octadecylvinyl ether-maleic anhydride copolymer and the product of this reaction is further reacted with a metal salt such as basic lead acetate. The hydroxyethyl pyrrolidone and hydroxyethyl acrylate are preferably charged in a 40:60 molar ratio which yields a resist copolymer containing approximately half of the anhydride groups unreacted and approximately half of the anhydride groups reacted to half esters said esterifying groups being in an approximate one to one ratio of hydroxyethyl pyrrolidone to hydroxyethyl acrylate. The product which is soluble in common solvents such as toluene readily forms smooth films on a substrate.
Upon irradiation with an electron beam, the resists of the invention crosslink at a low electron density to form an insoluble polymer (a negative resist) which is adherent to the substrate, is non-tacky and easily handled. The unexposed resist can be washed off readily to form the desired resist pattern.
DETAILED DESCRIPTION OF THE INVENTION
The electron beam sensitive materials of the invention are characterized by the following: (1) high improved sensitivity to electron beam irradiation; (2) insensitivity to visible light or near ultraviolet irradiation; (3) ease of forming smooth films on substrates; (4) resistance of the crosslinked polymer to wet or dry etch; (5) an ability of the material to be washed away readily in the unexposed areas with conventional solvents; (6) formation of a negative resist pattern; (7) superb contrast and resolution capabilities; (8) thermal stability; (9) good shelf life; (10) minimal dark reaction after exposure.
One embodiment of the material of the invention is prepared by esterifying an alkylvinyl ether-maleic anhydride copolymer with a mixture of N-hydroxyalkyl amide and hydroxyalkyl acrylate compounds and reacting this ester product with a metal salt to form the desired mixed half-ester copolymer. Then a thin film of the polymer is applied to a suitable substrate, such as chrome plated glass or quartz mask substrate, silicon wafer or a conductive polyeser substrate, and exposed to a beam of electrons at various charge densities.
The hydroxyalkyl amide component is either an N-hydroxyalkyl cyclic amide, such as hydroxyalkyl pyrrolidone, e.g. hydroxyethyl pyrrolidone, hydroxypropyl pyrrolidone, hydroxybutyl pyrrolidone, hydroxyethyl-γ-caprolactam, hydroxypropyl-γ-caprolactam, hydroxybutyl-γ-caprolactam and the like; or an N-hydroxyalkyl linear amide, such as N-hydroxyethyl acetamide, N-hydroxyethyl propionamide, and the like.
The terminally unsaturated component includes such compounds as allyl or propargyl alcohol and hydroxyalkyl acrylate, e.g. hydroxyethyl acrylate, or methacrylate, 3-hydroxypropyl acrylate or methacrylate, 4-hydroxybutyl acrylate or methacrylate or pentaerythritol triacrylate and the like.
Another embodiment of the material of the invention is prepared by reacting a metal complex of an alkylvinyl ether-maleic anhydride copolymer with a mixture of N-aminoalkyl amide and hydroxy alkyl acrylate compounds to form the desired mixed half-amide/ester copolymer. Then a thin film of the polymer is applied to a suitable substrate, such as chrome plated glass or quartz mask substrate, silicon wafer or a conductive polyester substrate, and exposed to a beam of electrons at various charge densities.
The aminoalkyl amide component is either an N-aminoalkyl cyclic amide, such as aminoalkyl pyrrolidone, e.g. aminoethyl pyrrolidone, aminopropyl pyrrolidone, aminobutyl pyrrolidone, aminoethyl-γ-caprolactam, aminopropyl-γ-caprolactam, aminobutyl-γ-caprolactam and the like; or an N-aminoalkyl linear amide, such as N-aminoethyl acetamide, N-aminoethyl propionamide, and the like.
EXAMPLE 1
Preparation of a lead complex of a mixed half-ester of octadecylvinyl ether-maleic anhydride copolymer
2.5 g., of a mixed half-ester product made by reacting 40 mole % of hydroxyethylpyrrolidone and 60 mole % hydroxyethyl acrylate with an octadecylvinyl ether-maleic anhydride copolymer was dissolved in 50 ml of hot isopropanol. To this soution was added, with stirring, a solution of 0.625 g. of lead acetate dissolved in 47 ml of hot-ethanol. An immediate precipitate forms and precipitation was completed by the addition of 50 ml of ice-cold methanol. The lead complex was filtered, washed with methanol and dried at 60° C. for 1 hour. The product was analyzed and contained 9.9% Pb.
EXAMPLE 2
Preparation of a rhodium complex of a mixed half-ester of octadecylvinyl ether-maleic anhydride copolymer.
3.88 g. of a mixed half-ester product made by reacting 40 mole % of hydroxyethylpyrrolidone and 60 mole % hydroxyethyl acrylate with an octadecylvinylether maleic anhydride copolymer was dissolved in 77.6 ml of hot isopropanol. To this solution was added 1 g. of rhodium trichloride dissolved in 20 ml of ethanol followed by 0.86 g, of stannous chloride dissolved in 20 ml of ethanol. The reactants were stirred at 70° C. for 30 minutes and the rhodium complex precipitated by the addition of 50 ml of cold methanol. The product was washed with methanol and dried at 60° C. for 1 hour.
EXAMPLE 3
Sensitivity of Resists Under Electron Beam Irradiation
Samples were prepared as described in Examples 1 and 2 were dissolved in toluene. They were then spin coated from toluene solution on chromed glass plates and dried. This left a thin film of the copolymer on the chrome. The coated plates were exposed to 15 kV electrons in a suitable device, the dose being varied over the plate through a range of 5×10 -8 to 5×10 -5 C/cm 2 . Exposure was adjusted to yield a pattern of 64 small squares, each receiving a different dose within this range. After exposure, plates were developed in a 1.1 (w/w) mixture of methylene chloride and isopropyl alcohol and dried. The thickness of the remaining resist was measured with a profilometer. A curve was constructed relating log (dose) to normalized thickness, where normalized thickness in the ratio of actual thickness over original thickness. The dose required for a normalized thickness of 0.5 is defined as sensitivity and the slope of the straight line portion of the curve defines its contrast.
The following metal containing polymers have been tested for electron sensitivity and it has been found that incorporation of the metal ions leads to an increase in sensitivity. This is shown in the following table which sets forth the sensitivity of two metal complexes of a mixed hydroxyethylacrylate-hydroxyethyl-pyrrolidone ester derivative of GANTREZ-AN8194.
__________________________________________________________________________ No Metal Rhodium Content Lead Complex ComplexEsterifying Alcohols or Sensitivity Sensitivity SensitivityRatio of Mixed Alcohols (C/cm.sup.2 × 10.sup.6) (C/cm.sup.2 × 10.sup.6) (C/cm.sup.2 × 10.sup.6)__________________________________________________________________________20 HEP/30 HEA 1.175 0.35 0.30__________________________________________________________________________ No Metal Content Calcium Complex Thallium ComplexEsterifying Alcohols or Sensitivity Sensitivity SensitivityRatio of Mixed Alcohols (C/cm.sup.2 × 10.sup.6) (C/cm.sup.2 × 10.sup.6) (C/cm.sup.2 × 10.sup.6)__________________________________________________________________________20 HEP/30 HEA 1.175 0.60 0.35__________________________________________________________________________ HEP is hydroxyethyl pyrrolidone HEA is hydroxyethyl acrylate
The rhodium complex is believed to differ from the lead and calcium salts in that the complexation occurs through olefinic groups rather than carboxylate groups.
While the invention has been described with reference to certain embodiments, it will be understood that changes and modifications may be made which are within the skill of the art. Accordingly, it is intended to be bound only by the appending claims.
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This invention describes an improved ionizing radiation sensitive material having high contrast, high sensitivity and comprised of a metal complex of a mixed half-ester or half amide product of the reaction of an N-hydroxy or N-aminoalkyl amide and a hydroxy alkyl terminally unsaturated compound with an alkylvinyl ether-maleic anhydride copolymer. A typical material is made by reacting a metal salt with the mixed half-ester or half-amide product of the reaction of an N-hydroxy or N-amino alkyl amide and a hydroxy alkyl terminally unsaturated compound with an alkyl vinyl ether-maleic anhydride copolymer.
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CROSS-REFERENCE TO RELATED APPLICATION
This application claims the priority, under 35 U.S.C. §119, of Austrian patent application AT A111/2014, filed Feb. 17, 2014; the prior application is herewith incorporated by reference in its entirety.
BACKGROUND OF THE INVENTION
Field of the Invention
The present invention relates to an installation for conveying materials, products, and the like, having at least one continuous conveyor belt which is guided via rollers, having a leading belt run for conveying the materials or products, respectively, and having a returning belt run, furthermore having a unit for detecting and controlling the tension of the conveyor belt, and having a unit for detecting deviations of the direction of movement of the conveyor belt from the correct direction of movement and for correcting the direction of movement of the conveyor belt, wherein the unit for detecting and controlling the tension of the conveyor belt displays a pressure-measuring apparatus which is situated at a mounting of a roller, and the unit for detecting deviations of the direction of movement of the at least one conveyor belt from the correct direction of movement and for correcting the deviations furthermore displays a sensor which is assigned to a lateral periphery of the conveyor belt, the output of the sensor, for the correction of the direction of movement of the at least one conveyor belt, serving for adjusting one of the mountings of one roller.
The present invention, in particular, relates to an installation for producing paper, having at least one wire belt or one felt belt, respectively, which is guided via rollers, in particular drying rollers, for producing a paper web, wherein the wire belt and the felt belt, respectively, represent a conveyor belt.
In the case of installations of this type for conveying materials, products, and the like, there is the requirement for orderly operation that the at least one conveyor belt exhibits a predetermined tension and that the conveyor belt is moved exactly in the conveying direction.
In the case of installations for producing paper the quality of the paper being produced is influenced by the tension of the wire belt or the felt belt, respectively. Furthermore, if the wire belt or the felt belt does not run in the correct direction of movement, the belt will move out of the directional path, on account of which the production process is disturbed.
In order to be able to control the tension of the conveyor belt it is known for one of the rollers via which the conveyor belt is guided to be configured with a pressure-measuring apparatus, in order to thereby detect the tension of the conveyor belt. The conveyor belt is moreover guided via a roller which is adjustable in the direction of movement of the conveyor belt, on account of which the tension of the conveyor belt can be controlled so as to be at the required value.
In order to be able to control the direction of movement of the conveyor belt it is known for a sensor to be assigned to one of the lateral peripheries of the conveyor belt, on account of which deviations from the required direction of movement of the conveyor belt can be identified. As has been narrated above, one of the two mountings of one of the rollers is configured with a pressure-measuring apparatus. Furthermore, the other mounting of this roller is adjustable in the direction of movement of the conveyor belt. On account of this adjustment of the mounting of one of the rollers in relation to the conveyor belt, which adjustment is controlled so as to emanate from the sensor, the direction of movement of the conveyor belt can be controlled so that the latter moves exactly in the required direction.
In the case of known installations for conveying materials, products, and the like, on the one hand, one of the mountings of one of the rollers is thus configured having a pressure-measuring apparatus which serves for detecting the tension of the conveyor belt, and, on the other hand, the other mounting of this roller is adjustable in relation to the conveyor belt, in order to thereby be able to control the direction of movement of the conveyor belt.
SUMMARY OF THE INVENTION
It is accordingly an object of the invention to provide an installation for conveying materials and products with a continuous conveyor belt, which overcomes the above-mentioned and other disadvantages of the heretofore-known devices and methods of this general type and which simplifies the constructive configuration of such a conveying installation.
With the foregoing and other objects in view there is provided, in accordance with the invention, a conveying installation, comprising:
at least one endless conveyor belt guided via a plurality of rollers, the conveyor belt having a leading belt run for conveying goods and a returning belt run;
at least one of the rollers having an adjustable mounting or bearing configured for adjusting and correcting a direction of movement of the at least one conveyor belt;
a tensioning unit for detecting and controlling a tension of the conveyor belt, the tensioning unit including a pressure-measuring apparatus disposed at the adjustable mounting of the one of the rollers;
a movement correction unit for detecting deviations of a direction of movement of the conveyor belt from a correct direction of movement and for correcting the direction of movement of the conveyor belt, the unit for detecting movement deviations including a sensor disposed to monitor a lateral periphery of the conveyor belt and having a sensor output configured for adjusting the adjustable mounting of the one of the rollers.
The installation is particularly configured as a papermaking installation for manufacturing a paper web, wherein the at least one conveyor belt is at least one wire belt or at least one felt belt.
In other words, the objects of the invention are achieved according to the invention in that the pressure-measuring apparatus for detecting the tension of the conveyor belt is situated at that mounting of one of the rollers that is adjustable for correcting the direction of movement of the at least one conveyor belt. The term mounting, as used herein, is substantially synonymous with the term bearing.
Since thus both the unit for detecting the tension of the conveyor belt and also the unit for controlling the direction of movement of the conveyor belt are assigned to the same mounting of a roller of the installation, the effect is simplification in the construction, the assembly, the maintenance and in the exchange of component parts. This advantageous effect is obtained in particular when an existing conveying installation is retrofitted, since then the assembly works required therefor have to be performed only on one side of one of the rollers.
Preferably, the mounting of that roller at which the pressure-measuring apparatus is disposed is situated on a carriage which is adjustable in the direction of movement of the conveyor belt, wherein the pressure-measuring apparatus is disposed between the mounting and the carriage.
According to one preferred embodiment, the unit for detecting and controlling the tension of the at least one conveyor belt displays a pressure-measuring apparatus, the output of which is guided to a control unit by way of which the tension of the conveyor belt is detected, wherein the output of the control unit serves for adjusting a further roller in the direction of movement of the conveyor belt. The unit for detecting and controlling the tension of the conveyor belt may furthermore display a roller which is wrapped to at least 10° by the conveyor belt and which is adjustable in the direction of movement of the conveyor belt. The carriage on which one of the mountings of the roller is situated is adjustable by means of a correcting unit which is actuatable in a hydraulic or pneumatic manner, respectively, and which is controlled by the unit for detecting deviations of the direction of movement from the correct direction of movement of the conveyor belt.
According to one further preferred embodiment, that mounting for a roller that is adjustable for correcting the direction of movement of the at least one conveyor belt, in particular adjustable in the direction of movement direction of said conveyor belt, is mechanically coupled for feedback to the sensor for identifying deviations of the direction of movement of the at least one conveyor belt from the correct direction of movement of the conveyor belt. Furthermore, that roller to which the units for detecting and controlling the tension of the conveyor belt and for detecting and correcting the direction of movement of the conveyor belt are assigned is preferably situated in the region of the returning run of the conveyor belt.
In particular, an installation according to the invention is configured having two continuous conveyor belts, the material to be conveyed being situated between them, wherein each of these two conveyor belts is guided via one roller in which one of the mountings is assigned a unit for detecting and controlling the tension of the conveyor belts, and this mounting furthermore is adjustable in the direction of movement of the assigned conveyor belt.
Other features which are considered as characteristic for the invention are set forth in the appended claims.
Although the invention is illustrated and described herein as embodied in Installation for conveying materials, products, and the like, having at least one continuous conveyor belt, it is nevertheless not intended to be limited to the details shown, since various modifications and structural changes may be made therein without departing from the spirit of the invention and within the scope and range of equivalents of the claims.
The construction and method of operation of the invention, however, together with additional objects and advantages thereof will be best understood from the following description of specific embodiments when read in connection with the accompanying drawings.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING
FIG. 1 shows a portion of an installation for producing a paper web, having two continuous felt belts which are movable so as to revolve, the paper web being situated between said felt belts, in a schematic illustration, and
FIG. 2 shows a roller via which a felt belt is guided, wherein one mounting of this roller is assigned a unit for detecting the tension of the felt belt and a unit for controlling the direction of movement of the felt belt, in an axonometric illustration.
DETAILED DESCRIPTION OF THE INVENTION
Referring now to the figures of the drawing in detail and first, particularly, to FIG. 1 thereof, there is shown a portion of an installation for producing paper with two groups of rollers 21 , 22 and 21 a , 22 a , respectively, and deflecting rollers 3 and 3 a , respectively, which are assigned to the former, and two continuous felt belts 1 and 1 a , respectively, which are movable so as to revolve. The belts are guided via the rollers 21 a , 22 and 22 a , respectively, and the deflecting rollers 3 and 3 a , respectively. A paper web 4 thereby moved through this portion is situated between the felt belts 1 and 1 a , respectively, and the rollers 22 and 22 a , respectively.
The rollers 22 and 22 a , respectively, which are heated rollers, represent drying rollers for the paper web 4 . At least some of the rollers 22 and 22 a , respectively, are driven.
In the left region illustrated in the drawing, the paper web 4 is guided via the roller 21 of the first group of rollers. Consequently, the felt belt 1 bears on the paper web 4 , which felt belt 1 at the same time is guided together with the paper web 4 via the roller 21 a of the second group of rollers, the felt belt 1 being situated between the paper web 4 and the roller 21 a . Thereafter, the felt belt 1 and the paper web 4 reach the first roller 22 of the first group of the rollers, the paper web 4 being situated between the felt belt 1 and this roller 22 . Continuing therefrom, the felt belt 1 is guided via the first deflecting roller 3 of the deflecting rollers assigned to the first rollers to the following roller 22 , whereas the paper web 4 moves via the first roller 22 a of the second group of the rollers which are assigned to the second felt belt 1 a . The second felt belt 1 a is moved via the first deflecting roller 3 a of the deflecting rollers 3 a assigned to the second group of rollers and consequently comes to bear on the paper web 4 which is guided via the first roller 22 a , the paper web 4 being situated between the second felt belt 1 a and the first roller 22 a . Thereafter, the second felt belt 1 a is guided via a further deflecting roller 3 a and a further roller 22 a.
Continuing therefrom the first felt belt 1 is guided via the further deflecting rollers 3 and the further rollers 22 , and the second felt belt 1 a is guided via the further deflecting rollers 3 a and via the further rollers 22 a.
The paper web 4 is guided in an alternating manner via a roller 22 of the first group of the rollers and via a roller 22 a of the second group of the rollers 22 a , the paper web 4 in the regions of the rollers 22 and 22 a , respectively, always being situated between one of the two felt belts 1 and 1 a , respectively, and the rollers 22 and 22 a , respectively.
At the end of this portion of this installation, the felt belts 1 and 1 a , respectively, are guided back to the beginning of this portion via further rollers 31 , 32 , 33 , 34 and 31 a , 32 a , 33 a , respectively, by way of which the felt belts 1 and 1 a , respectively, are deflected.
In the case of installations for producing a paper web there is, on the one hand, the requirement that the at least one felt belt displays a predetermined tension, since the quality of the produced paper depends on the tension of the felt belt or the felt belts, respectively. It must furthermore be ensured that the felt belt or the felt belts, respectively, moves or move in exactly the correct direction of movement, since a deviation of the felt belt or the felt belts, respectively, from the correct movement path causes functional disruptions in the operation of this installation.
In order to have the effect of controlling the tension of the at least one felt belt, a unit 5 for detecting and controlling the tension of the felt belt 1 is provided in the region of the returning run of the first felt belt 1 . The unit 5 is also referred to as a tensioning unit. The roller 33 here is assigned a pressure-measuring apparatus 51 by way of which the pressure exerted on the roller 33 by the felt belt 1 is detected. The output signal of the pressure-measuring apparatus 51 is transmitted via a measuring line 52 to a control unit 53 by way of which the tension of the felt belt 1 is detected. The output of the control unit 53 is transmitted via a control line 54 to a correcting unit 55 for the roller 32 , by way of which the roller 32 is displaceable in the direction of movement of the felt belt 1 . The roller 32 is wrapped to 90° by the first felt belt 1 . The wrapping is at least 10° and may also be 180°. On account of this wrapping, the tension of the felt belt 1 can be controlled to be a predetermined value by way of an adjustment of the roller 32 .
Two end positions of the displaceable roller 32 are illustrated in FIG. 1 .
Furthermore, a unit 6 for detecting deviations of the first felt belt 1 from the correct movement path and for correcting the direction of movement of the felt belt 6 is provided, which unit 6 includes a sensor 61 , which is assigned to a periphery of the felt belt 1 , and a control unit 62 . The unit 6 is also referred to as a movement correction unit. Deviations in the direction of movement of the felt belt 1 from the correct direction of movement are detected by the sensor 61 . Correction of the direction of movement of the felt belt 1 is performed by way of the control unit 62 . To this end, the roller 33 is configured having a mounting which is displaceable in the direction of movement of the felt belt 1 . By way of an adjustment of this mounting the angular position of the roller 33 in relation to the felt belt 1 is modified, on account of which the direction of movement of the felt belt 1 is controllable.
In an analogous manner, a unit 5 a (also referred to as a tensioning unit) for detecting and controlling the tension of the felt belt 1 a is assigned to the roller 33 a , via which the returning run of the second felt belt 1 a is guided. Here, one of the two mountings of the roller 33 a is assigned a pressure-measuring apparatus 51 a by way of which the pressure exerted on the roller 33 a by the felt belt 1 a is detected. The output signal of the pressure-measuring apparatus 51 a is transmitted via a measuring line 52 a to a control unit 53 a , by way of which the tension of the felt belt 1 a is detected. The output of the control unit 53 a is guided via a control line 54 a to a correcting unit 55 a , by way of which the roller 32 a which is wrapped by the felt belt 1 a is displaceable in the direction of movement of the felt belt 1 a , on account of which the tension of the felt belt 1 a is controllable.
Furthermore, a unit 6 a (also referred to as a movement correction unit) for detecting deviations of the second felt belt 1 a from the correct movement path and for correcting the direction of movement of the felt belt 1 a is provided, which unit 6 a displays a sensor 61 a , which is assigned to a periphery of the felt belt 1 a , and a control unit 62 a . Deviations of the direction of movement of the felt belt 1 a from the correct direction of movement are detected by the sensor 61 a . Correction of the direction of movement of the felt belt 1 a is performed by the control unit 62 a . To this end, the roller 33 a is configured having a mounting which is displaceable in the direction of movement of the felt belt 1 a . By way of an adjustment of this mounting the angular position of this roller 33 a in relation to the felt belt 1 a is modified, on account of which the direction of movement of the felt belt 1 a is controllable.
The functioning of the units for detecting the tension of the two felt belts 1 and 1 a , respectively, for controlling the tension of the felt belts 1 and 1 a , respectively, for detecting deviations of the direction of movement of the felt belts 1 and 1 a , respectively, from the correct direction of movement, and for correcting the directions of movement of the two felt belts 1 and 1 a , respectively, are explained by means of FIG. 1 .
To this end it is noted here that the felt belts 1 and 1 a represent the conveyor belts for the paper web 4 .
An embodiment according to the invention of these units will now be explained below with reference to FIG. 2 .
In FIG. 2 the roller 33 via which the felt belt 1 is guided and of which one of the mountings is configured having the pressure-measuring apparatus 51 is illustrated. The tension of the felt belt 1 is controllable by means of units 5 assigned to this roller 33 . Furthermore, the mounting of this roller 33 is displaceable in the direction of movement of the felt belt 1 , on account of which the direction of movement of the felt belt 1 is controllable.
The roller 33 , on one of its two ends, is mounted on a bearing mounting 30 which is situated on a carriage 60 which is displaceable in the direction of movement of the felt belt 1 . The pressure-measuring apparatus 51 which is preferably configured as a support-pressure measuring apparatus is situated between the bearing mounting 30 and the carriage 60 . The output of the pressure-measuring apparatus 51 is guided via the control line 52 to the control unit 53 . By way of the pressure-measuring apparatus 51 that pressure which is exerted on the roller 33 by the felt belt 1 is detected. The tension of the felt belt 1 is calculated therefrom by means of the control unit 53 . By way of the output signal of the control unit 53 , which is guided via the control line 54 to the correcting unit 55 , the correcting unit 55 is controlled so that the roller 32 is adjusted in the direction of movement of the felt belt 1 , on account of which the tension of the felt belt 1 is controlled.
The unit 6 for controlling and correcting the direction of movement of the felt belt 1 is configured having the sensor 61 which is pivotably mounted on a support frame 63 . Since the sensor 61 bears on one of the two lateral peripheries 11 of the felt belt 1 , said sensor 61 is pivoted by a deviation of the felt belt 1 from the correct direction of movement. On account of the sensor 61 being pivoted, a control valve 62 which is situated in a hydraulic or pneumatic control system is activated. Pressure lines 64 which lead to a correcting cylinder 65 having a correcting piston 66 are connected to the control valve 62 . The carriage 60 on which the bearing mounting 30 is situated is adjustable by the correcting piston 66 . By an adjustment of the carriage 60 the bearing mounting 30 is adjusted in the direction of movement of the felt belt 1 , on account of which the angular position of the roller 33 in relation to the direction of movement of the felt belt 1 is modified. By way of this modification of the angular position of the roller 33 the direction of movement of the felt belt 1 is controlled.
Since the bearing mounting 30 is coupled to the support frame 63 by way of a linkage 67 , a mechanical coupling for feedback of this control pertaining to the position of the sensor 61 is performed.
The adjustment of the carriage 60 by way of the output signal of the sensor 61 may also be electrically controlled.
Another correcting unit for the carriage 60 may also be provided in place of the correcting cylinder 65 having the correcting piston 66 .
The units for detecting and for controlling the tension of the felt belt 1 a and for detecting and controlling the direction of movement of the felt belt 1 a which are assigned to the second felt belt 1 a are configured in the same manner.
In the case of this constructive design it is relevant that the units for detecting the tension of the felt belts 1 and 1 a , respectively, and for controlling the directions of movement of the felt belts 1 and 1 a , respectively, are assigned to only one of the two mountings of a roller via which the felt belt 1 is guided, on account of which simplifications in erecting, converting, operating, and maintaining the installation can be achieved.
The present invention has been explained above by means of an installation for producing paper, in which the felt belts represent the conveyor belts for the paper web produced in the installation. However, the invention is also applicable to other installations which display at least one movable and continuous conveyor belt for transporting or for processing, respectively, materials or goods, respectively, since in the case of installations of this type controls for the tensions of the conveyor belts and for monitoring and correcting the directions of movement of the conveyor belts are required.
The following is a summary list of reference numerals and the corresponding structure used in the above description of the invention:
1 , 1 a Felt belts 11 Periphery of felt belt 1 21 , 22 , 21 a , 22 a Rollers 3 , 3 a Deflecting rollers 31 , 32 , 33 , 34 Rollers 31 a , 32 a , 33 a Rollers 30 Bearing mounting 4 Paper web 5 , 5 a Tensioning units, units for detecting and for controlling tension 51 , 51 a Pressure-measuring apparatuses 52 , 52 a Measuring lines 53 , 53 a Control units 54 , 54 a Control lines 55 , 55 a Correcting units 6 , 6 a Movement correction units, units for detecting and for controlling the direction of movement 60 Carriage 61 , 61 a Sensors 62 , 62 a Control units 63 Support frame 64 Control lines 65 Correcting cylinders 66 Correcting pistons 67 Linkage
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A conveying installation has least one endless conveyor belt guided via a plurality of rollers along a leading belt run for conveying material or products and a returning belt run, particularly for manufacturing a paper web with a wire belt or felt belt. At least one of the rollers has an adjustable mounting for adjusting and correcting a direction of movement of the conveyor belt. A tensioning unit for detecting and controlling a tension of the conveyor belt has a pressure-measuring apparatus disposed at the adjustable mounting. A movement correction unit for detecting deviations of a direction of movement of the conveyor belt from a correct movement and for correcting the movement includes a sensor that is disposed to monitor a lateral periphery of the conveyor belt. A sensor output of the sensor is used for adjusting the adjustable mounting of the one of the rollers.
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RELATED APPLICATIONS
[0001] This nonprovisional patent application claims the benefit of co-pending, provisional patent application U.S. Ser. No. 60/476,746, filed on Jun. 6, 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 generally to reciprocating pumps, more specifically to a coolant system for the piston and liner of the reciprocating pumps.
[0004] 2. Background of the Invention
[0005] In oil field operations, reciprocating pumps are often used for various purposes. Some reciprocating pumps, generally known as “mud pumps,” are typically used for well drilling operations. During operation, the pistons and liners of the pumps generate large amounts of heat due to friction. It is desirous to cool the liners and pistons in order to extend their operation lives, which in turn increases overall efficiency and reduces down-time for maintenance.
[0006] Prior systems for cooling pistons and liners includes various coolant injector systems. For example, in one system, a coolant line or hose is physically coupled to the piston rod with a the hose feeding into the piston. The coolant hose moves with the piston rod during operations. The hose in this system typically has a short life due to wear associated with moving with the piston rod. Another system includes a hose that connects to an outer surface of the piston rod that transmits the coolant through the piston rod to a sprayer located in the piston rod adjacent the piston. The hose in this assembly also has problems with wear because the hose connects to and reciprocates with the piston rod.
SUMMARY OF THE INVENTION
[0007] In this invention, a reciprocating pump assembly includes piston rod that is movable and reciprocates in order to pump a fluid. The piston rod has a piston portion at an end that stokes within a piston chamber. The pump assembly also includes a piston rod sleeve that houses the piston rod. The piston rod sleeve does not reciprocate with the piston rod, so the piston rod sleeve remains stationary. The piston rod sleeve also defines and annulus between the piston rod and the piston rod sleeve. The pump assembly has a fluid line that leads into the annulus. The fluid line delivers coolant to the annulus. The pump assembly also includes a flow passage. The flow passage has an inlet in fluid communication with the annulus for receiving the coolant. The passage also has an outlet in fluid communication with the piston chamber for delivering the coolant.
[0008] The flow passage of the pump assembly may be located within the piston rod. As such, the coolant flows through an interior of the piston rod between the inlet and outlet of the flow passage. The pump assembly can also include a fluid sprayer. The sprayer is typically located at the outlet of the flow passage in order to deliver a spray of fluid into the piston chamber.
[0009] The piston rod can include an outer shell that has an inner circumference. The piston rod can also include a pony rod that is located within the outer shell and has an outer circumference that is less than inner circumference of the outer shell. The pony rod and the outer shell define a clearance between the inner surface of the outer shell and the outer surface of the pony rod. The clearance can be a portion of the flow passage for carrying the coolant from the annulus and the piston chamber.
BRIEF DESCRIPTION OF THE DRAWINGS
[0010] [0010]FIG. 1 is a schematic elevational view of a reciprocating pump assembly constructed in accordance with this invention.
[0011] [0011]FIG. 2 is a top plan schematic view of the reciprocating pump assembly shown in FIG. 1.
[0012] [0012]FIG. 3 is a sectional view of a portion of the pump assembly shown in FIG. 1.
[0013] [0013]FIG. 4 is an enlarged sectional view of a portion of the pump assembly shown in FIG. 1.
[0014] [0014]FIG. 5 is an enlarged portion of the portion of the pump assembly shown in FIG. 4.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0015] Referring to FIG. 1, a reciprocating pump 11 includes a crankshaft housing 13 that comprises a majority of the outer surface of reciprocating pump 11 shown in FIG. 1. A piston rod housing 15 attaches to a side of crankshaft housing 13 and extends to a piston chamber or cylinder 17 . Cylinder 17 preferably includes a fluid inlet 19 and a fluid outlet 21 (FIG. 2).
[0016] Referring to FIG. 2, piston rod housing 15 is segmented into three portions, each portion comprising a piston throw 23 . Reciprocating pump 11 as shown in FIG. 2 has three piston throws 23 , which is commonly know as a triplex, but could also be segmented for five piston throws 23 , which is commonly known as a quintuplex pump. The description focuses on a triplex pump, but as will be readily apparent to those skilled in the art, the features and aspects described are easily applicable for pumps with various numbers of piston throws 23 . Each piston throw 23 houses a piston rod 33 (FIG. 3) extending toward cylinder 17 . As shown in FIG. 2, each piston throw 23 extends in the same longitudinal direction from crankshaft housing 13 .
[0017] Referring to FIG. 3, a portion of reciprocating pump 11 housed within crankshaft housing 13 is shown. Crankshaft housing 13 houses a crankshaft 25 , which is typically connected to a motor (not shown). The motor (not shown) rotates crankshaft 25 in order to drive reciprocating pump 11 . In the preferred embodiment, crankshaft 25 is cammed so that fluid is pumped from each piston throw 23 at alternating times. As is readily appreciable by those skilled in the art, alternating the cycles of pumping fluid from each of cylinders 17 helps minimize the primary, secondary, and tertiary (et al.) forces associated with reciprocating pump 11 . In the preferred embodiment, a connector rod 27 includes an end that connects to crankshaft 25 and another end that engages a crosshead 29 . Connector rod 27 connects to crosshead 29 through a crosshead pin 31 , which holds connector rod 27 longitudinally relative to crosshead 29 . Connector rod 27 pivots about crosshead pin 31 as crankshaft 25 rotates with the other end of connector rod 27 . A piston rod 33 extends from crosshead 29 in a longitudinally opposite direction from crankshaft 25 . Connector rod 27 and crosshead 29 convert rotational movement of crankshaft 25 into longitudinal movement of piston rod 33 . A crosshead housing 32 , located in crankshaft housing 13 , extends longitudinally away from crankshaft 25 . In the preferred embodiment, crosshead housing 32 guides crosshead 29 as crosshead 29 reciprocates longitudinally relative to crankshaft 25 .
[0018] Referring to FIG. 4, a piston portion 35 connects to piston rod 33 for pumping the fluid passing through reciprocating pump 11 . As illustrated in FIG. 4, piston portion 35 is a piston. Cylinder 17 (FIG. 1) connects to the end of piston rod housing 15 extending away from crankshaft housing 13 (FIG. 1). Cylinder 17 typically includes a cylinder chamber, which is where the fluid being pumped by reciprocating pump 11 is pressurized by piston 35 . Piston rod 33 preferably includes an outer shell or outer casing 37 and a pony rod 39 , that are each connected to and extending away from crosshead 29 . Pony rod 39 is preferably a solid shaft having a threaded profile toward the end extending away from crosshead 29 . Outer casing 37 preferably encloses a substantial portion of pony rod 39 , thereby defining a rod annulus 40 in the area between pony rod 39 and outer casing 37 .
[0019] Piston rod 33 also preferably includes a tubular extension or extension rod 41 connected to the ends of pony rod 39 and outer casing 37 . Extension rod 41 extends longitudinally away from crankshaft 25 (FIG. 3) to connect piston rod 33 with piston 35 . Piston rod 33 also preferably includes a rod clamp assembly 43 that connects extension rod 41 with the ends of outer casing 37 and pony rod 39 . In the preferred embodiment, rod clamp assembly 43 includes an intermediate casing 45 that abuts an end portion of outer casing 37 and receives a portion of pony rod 39 . A portion of intermediate casing 45 is flared so that the outer diameter of intermediate casing 45 located toward the end extending away from crankshaft 25 is greater than other portions of intermediate casing 45 . Extension rod 41 also has a flared portion located toward the end of extension rod 41 that is being connected to pony rod 39 and outer casing 37 .
[0020] The flared portions of intermediate casing 45 and extension rod 41 abut and are held relative to each other by an outer clamp 47 . Outer clamp 47 encloses the interface of intermediate casing 45 and extension rod 41 . Outer clamp 47 has a recess portion which surrounds the flared portions of extension rod 41 and intermediate casing 45 . Therefore, as outer casing 37 reciprocates longitudinally toward and away from crankshaft 25 , extension rod 41 must also reciprocate toward and away crankshaft 25 .
[0021] In the preferred embodiment, extension rod 41 is a tubular member which also receives and encloses a portion of pony rod 39 . Preferably an inner sleeve 49 , having a threaded profile that matingly engages with the threaded profile located toward the end of pony rod 39 extending away from crankshaft 25 , is positioned at the interface of intermediate casing 45 and extension rod 41 . Intermediate casing 45 preferably includes an inner bore which receives a portion of inner sleeve 49 and prevents inner sleeve 49 from moving relative to intermediate casing 45 closer to crankshaft 25 . Extension rod 41 also preferably has an inner bore which receives a portion of inner sleeve 49 , which prevents inner sleeve 49 from moving relative to extension rod 41 . In the preferred embodiment, an extension rod annulus 50 is defined between piston 35 , inner sleeve 49 , the end of pony rod 39 extending away from crankshaft 25 , and the interior of extension rod 41 . Piston 35 connects to the end of extension rod 41 extending away from rod clamp assembly 45 . In the preferred embodiment, a plurality of passages 51 extend longitudally through inner sleeve 49 , between rod annulus 40 and extension rod annulus 50 , around the threaded portion of pony rod 39 so that rod annulus 40 and extension annulus 50 are in fluid communication through rod clamp assembly 43 .
[0022] A piston liner 55 adjoins to an interior surface of cylinder 17 . In the preferred embodiment, piston liner 55 is in fluid communication with an interior portion of cylinder 17 and thereby defining a pumping chamber of reciprocating pump assembly 11 . Piston 35 slidingly engages piston liner 55 as piston 35 reciprocates longitudinally toward and away from crankshaft 25 . Reciprocating piston 35 within piston liner 55 causes the volume of the pumping chamber to increase and decrease as piston 35 reciprocates longitudinally toward and away from crankshaft 25 , thereby positively displacing the fluid being pumped through reciprocating pump 11 .
[0023] Piston 35 typically experiences wear from the heat created by sliding engagement of piston liner 55 during normal pumping operations. Typically the fluid being pumped through the pumping chamber of reciprocating pump 11 helps to lubricate and cool the portion of piston liner 55 on the cylinder side of piston 35 . A coolant assembly 57 provides coolant to the crankshaft 25 side of piston 35 to prevent excessive heat and wear between piston 35 and piston liner 55 . In the preferred embodiment, coolant assembly 57 preferably includes a piston rod sleeve or coolant sleeve 59 extending between crosshead housing 32 and the portion of crankshaft housing 13 that engages piston rod housing 15 . Coolant sleeve 59 preferably encloses outing casing 37 of piston rod 33 and is stationary. Seals 61 preferably seal the end of coolant sleeve 59 adjacent crosshead housing 32 and the end of connector sleeve 59 adjacent rod clamp assembly 43 . The interior surface of coolant sleeve 59 and seals 61 thereby define a sleeve annulus 63 surrounding outer casing 37 of piston rod 33 . In the preferred embodiment, a fluid line or injector hose 65 injects a coolant into sleeve annulus 63 through a sleeve port 67 extending through a side of sleeve 59 . Injector hose 65 typically extends away from lubricator sleeve 59 to an outer surface of crankshaft housing 13 to receive the coolant from a coolant source (not shown).
[0024] In the preferred embodiment, seal 61 located adjacent crosshead housing 32 is placed a predetermined distance from seal 61 located adjacent the end of crankshaft housing 13 extending away from crankshaft 25 , such that the distance between seals 61 is greater than or substantially equal to the length of the stroke of piston 35 . In the preferred embodiment, an outer shell or casing port 69 extends through a side of outer casing 37 of piston rod 33 . Rod annulus 40 and sleeve annulus 63 are in full communication through outer casing port 69 . Rod annulus 40 and sleeve annulus 63 are in fluid communication throughout the entire stroke length of the piston rod. In the preferred embodiment, outer casing port 69 is formed on a portion of outer casing 37 such that outer casing port 69 is always substantially between seals 61 during operations of reciprocating pump 11 . Therefore, coolant from injector hose 65 that accumulates in sleeve annulus 63 can readily communicate through outer casing port 69 into rod annulus 40 while piston rod 33 reciprocates toward and away from crankshaft 25 . In the preferred embodiment, the coolant that communicates from sleeve annulus 63 through outer casing port 69 travels along pony rod 33 toward passages 51 and inner sleeve 49 . The coolant communicates through passages 51 from rod annulus 40 and into extension annulus 50 toward piston 35 .
[0025] Referring to FIGS. 4 and 5, a spray port 71 is formed in extension rod 41 at a position adjacent piston 35 . An injector sprayer 73 is preferable located within a spray port 71 . Spray port 71 and injector sprayer 73 are preferably angled so that coolant is sprayed along the crankshaft 25 (FIG. 3) side of piston 35 and piston liner 55 . Therefore, in the preferred embodiment the coolant flows from sleeve annulus 63 through a continues passage that includes outer casing port 69 , rod annulus 40 , passages 51 within clamp assembly 43 , extension annulus 50 and spray port 71 . This flow passage is merely a preferred embodiment, and as will be readily appreciated by those skilled in the art, this passageway is subject change due to slight variations.
[0026] Coolant assembly 57 advantageously provides coolant to the crankshaft 25 side of piston 35 and piston liner 55 . This reduces excessive heat and wear between piston 35 and piston liner 55 . Coolant assembly 57 also advantageously provides and assembly in which fluid line or fluid hose 65 remains stationary during pump operations. Therefore, hose 65 is not subject to the reciprocating movements that cause wear and failure in previous cooling assemblies. Accordingly, pumping operations can continue for longer periods of time between replacement of the fluid hose 65 .
[0027] While the invention has been shown in only one of its forms, it should be apparent to those skilled in the art that it is not so limited, but is susceptible to various changes without departing from the scope of the invention. For example, injector hose 65 can extend from lubricator sleeve 59 toward a side portion of crankshaft housing 13 as shown in FIG. 4 or toward a lower portion of crankshaft housing 13 as shown in FIG. 3 to receive coolant fluid from a coolant source (not shown). A further example that can be readily appreciated by those still in the art, while the invention has only been shown with respect to mud pumps, the same lubrication system can also be easily adapted for service pumps using a piston attached to a pony rod.
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A reciprocating pump assembly includes piston rod that is movable and reciprocates in order to pump a fluid. The piston rod has a piston portion at an end that stokes within a piston chamber. The pump assembly also includes a piston rod sleeve that houses the piston rod. The piston rod sleeve does not reciprocate with the piston rod. Thus, the piston rod sleeve remains stationary. The piston rod sleeve defines and annulus between the piston rod and the piston rod sleeve. The pump assembly has a fluid line that leads into the annulus. The fluid line delivers coolant to the annulus. The pump assembly also includes a flow passage. The flow passage has an inlet in fluid communication with the annulus for receiving the coolant. The passage also has an outlet in fluid communication with the piston chamber for delivering the coolant.
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FIELD OF THE INVENTION
[0001] This invention relates to a dynamic random access memory, and more particularly, to a memory cell that uses a stacked capacitor, for use in such a memory and to a method for making the stacked capacitor.
BACKGROUND OF THE INVENTION
[0002] A standard dynamic random access memory (DRAM) employs, as the memory cell that is formed in a large array in a silicon chip, a series combination of a switch, generally a MOSFET, and a storage capacitor in which a binary digit (bit) is stored as information for later recovery. In one form of DRAM, the storage capacitor is formed by a stack of layers over the top surface of the silicon chip with the MOSFET switch formed within a region near the top surface of the chip. A conductive plug typically provides a low resistance connection between a source/drain region of the MOSFET in the chip and the layer of the stack that serves as the lower plate (bottom electrode) of the storage capacitor.
[0003] To achieve high capacity in DRAMS it is important to make the cells small and to position them closely. It is accordingly important that the stacked capacitor in a DRAM use little surface space on the surface of the chip but still provide a sufficiently high capacitance to serve reliability as the storage node.
SUMMARY OF THE INVENTION
[0004] The present invention is a DRAM that comprises an improved stacked capacitor and a process for the manufacture of such a DRAM. As is known, generally the manufacture is largely done on a wafer scale and eventually the wafer is diced into a chip that will house one or more DRAMS. It will be convenient to discuss the processing primarily with respect to a portion of a chip that will house a single memory cell.
[0005] The essential elements of the improved capacitor for a memory cell are formed by first forming a contact hole in the dielectric layer that overlies the top surface of a portion of the silicon chip that houses a switching transistor. A contact hole is formed for each capacitor over the region of the switching transistor where the capacitor is to be connected. A conductive plug, typically of doped polysilicon, is then provided at a bottom portion of the contact hole to make a low resistance connection to such region of the transistor, such region corresponding to the storage node of the cell. Typically this is done by first filling the contact hole with a conductor and then removing the top portion of the fill. This leaves only a bottom plug portion. The empty top portion of the contact hole is then widened by etching. The wall of the widened trench is now coated with a layer of a conductor, advantageously platinum, to form a low resistance connection between the coating and the conductive plug. This conductive layer serves as the lower plate (bottom electrode) of the capacitor. When the conductive plug is of a material that needs to be prevented from diffusing into the conductor serving as the lower plate of the capacitor, as is the case with platinum, there should be interposed between the plug and the lower plate a layer of a material that will serve as a barrier to such diffusion. After the deposition of the conductive layer, the diffusion barrier and conductive layer are patterned to localize each in the interior of the widened trench for proper isolation. The conductive layer is then coated with a material of dielectric constant suitable for use as the capacitor dielectric. A layer of barium strontium titanate is presently preferred because its very high dielectric constant makes for an efficient capacitor dielectric. The dielectric layer in turn is coated with a conductive layer, also advantageously of platinum. This platinum layer serves as the upper plate (top electrode) of the capacitor. Of course, measures need be taken to avoid electric shorts between the top and bottom electrodes of the capacitor.
[0006] An advantage of this capacitor design is that the storage trench is essentially self-aligned so that its fabrication can be done with a reduced number of lithography steps. Another advantage of this capacitor is that it can readily be made with relatively thin layers of platinum as compared to the layers used in prior design. Platinum is advantageous because of both its favorable work function and its resistance to oxidation.
[0007] It is important that individual storage cells be isolated. Accordingly, it is important that the first layer and any diffusion barrier layer be patterned to avoid shorts as discussed above. However, the dielectric layer that serves as the capacitor dielectric and the conductive layer that serves as the upper plate of the capacitor can be extended over the chip to serve in the same roles in other cells of the memory cell array.
[0008] Viewed from one process aspect, the present invention is directed to a method for forming a memory cell including a transistor and a capacitor. The method comprises the steps of: forming in a semiconductor chip a transistor having first and second regions of one conductivity-type spaced apart by a region of the opposite conductivity-type along a top surface of said chip; forming a dielectric layer over a top surface of the chip; forming a contact hole with substantially vertical side walls in the dielectric layer by anisotropic etching for exposing a top surface portion of said second region of the transistor; filling the contact hole with a conductive fill for providing a low resistance connection to said second region; removing the top portion of the conductive fill of the contact hole for forming a recess in the conductive fill and exposing the dielectric layer in the contact hole; etching the exposed dielectric layer isotropically for widening the recess and enlarging the surface area of the contact hole in the dielectric layer; depositing a first conductive layer conformally over the enlarged surface area of the contact hole suitable for use as a lower plate of a storage capacitor; patterning this conductive layer for confining it essentially to the interior of the contact hole, depositing a layer of a material of high dielectric constant for covering the first conductive layer; and depositing a second conductive layer conformally over the last mentioned dielectric layer suitable for use as an upper plate of a capacitor that comprises electrically isolated upper and lower plates separated by the layer of high dielectric constant.
[0009] Viewed from an other process aspect, the present invention is directed to a method of forming a stacked capacitor on the top surface of a silicon wafer for use as a storage capacitor in series with a switching transistor formed in a top surface portion of the silicon wafer. The method comprises the steps of: forming a first dielectric layer over the top surface of the silicon wafer; forming a contact hole in the dielectric coating for exposing the portion of the silicon transistor to which the lower plate of the storage capacitor is to be electrically connected; partially filling the contact hole with doped polysilicon suitable for forming an electrical connection to said portion of the silicon transistor; widening the unfilled portion of the contact hole to a cup-shape for enlarging the surface area of the unfilled portion; forming a diffusion barrier conductive layer over the doped polysilicon; depositing conformally over the surface of the unfilled portion of the contact hole, a first conductive layer suitable for serving as said lower plate of the capacitor; ion etching to remove any conductive material from the top surface of the first dielectric layer in order to fully separate and isolate individual storage cell trenches; depositing conformally over the first conductive layer and the contact hole a second dielectric layer suitable for serving as the dielectric of the capacitor; and depositing conformally over the second dielectric layer a second conductive layer suitable for serving as the upper plate of the capacitor without providing an electrical short to the lower plate of the capacitor.
[0010] Viewed from an apparatus aspect, the present invention is directed to a memory cell for use in a dynamic random access memory. The memory cell comprises a silicon chip whose active area is of one conductivity type and along whose top surface are spaced regions of the opposite conductivity type; and a dielectric coating over said top surface including a cup-shaped contact hole, the cup-shaped contact hole including a bottom plug portion making a low resistance connection to one of the spaced regions, and overlying the cup-shaped walls of the contact hole a conformal lower conductive layer, an intermediate dielectric layer, and an upper conductive layer, said lower and upper conductive layers being electrically isolated by said intermediate dielectric layer and forming a storage capacitor for the memory cell.
[0011] A more detailed description of the process and the resulting capacitor will be described with reference to the accompanying drawing.
BRIEF DESCRIPTION OF THE DRAWINGS
[0012] [0012]FIG. 1 shows a cross section of a memory cell in accordance with the present invention; and
[0013] Each of FIGS. 2 - 6 illustrate a portion of the silicon chip in a different stage in the formation of a stacked capacitor that is characteristic of a memory cell in accordance with the present invention.
[0014] It is to be noted the drawings are not to scale.
DETAILED DESCRIPTION
[0015] [0015]FIG. 1 shows in cross section a portion of a silicon chip 20 that includes a memory cell including a stacked capacitor in accordance with the present invention. The silicon chip 20 , whose bulk is for example, of p-type resistivity, includes at a top surface 21 thereof spaced first and second regions 22 a and 22 b , respectively of n-type conductivity to form an n-channel MOSFET. The two regions serve as the current terminals of the switch and operate as the source and drain of the MOSFET. It will be convenient hereinafter to describe region 22 a as the source and region 22 b as the drain, although, as is known, their roles reverse as logic information is written into or read out of a memory cell. A gate electrode 23 overlies the p-type region between the spaced n-type regions 22 a and 22 b and is separated from the surface by the gate oxide 25 in the manner characteristic of a MOSFET. Overlying the top surface 21 is a dielectric coating 26 typically largely of silicon oxide, that eventually includes the bit and word line conductors (not shown) necessary to provide the connections to the cell for writing into and reading out of a bit stored in the cell, in the usual manner. To provide storage the storage capacitor needs to be connected in series with the transistor region that is to serve as the storage node, the second (drain) region 22 b . To this end, the capacitor includes a conductive plug 27 that makes low resistance connection to the second region 22 b , a first essentially cup-shaped conductive layer 37 that serves as the first (lower) plate of the capacitor, an overlying dielectric layer 38 that covers and isolates the first conductive layer 37 , and a conformal second conductive layer 39 that overlies the dielectric layer 38 and serves as the upper or second plate of the capacitor. This second conductive layer 39 is generally connected to one terminal of the power supply, typically ground. Generally the first conductive region 22 a is connected to the bit line and the gate electrode 23 to the word line of the DRAM.
[0016] Although not an essential part of the capacitor, as previously mentioned, when platinum and polysilicon are used, it is generally advantageous to include below the first platinum layer 37 , a layer 36 , as of a material such as TiN, TaSiN, or TiAlN, either conformally over the entire surface of the opening as shown or selectively only over the polysilicon plug. This layer improves wetting of the platinum and also serves to minimize any interdiffusion or interaction between plug 27 and platinum layer and prevents the formation of high resistance interfacial layers during high-temperature processing steps (such as the deposition of the high dielectric material).
[0017] In the subsequent figures to be used in describing the fabrication of the capacitor, there is shown only portion 22 b of the silicon wafer 20 and the dielectric constant coating 26 .
[0018] In the fabrication of the capacitor, there is first formed over the dielectric coating 26 a layer of photoresist 31 that is patterned to serve as an etch mask for forming a contact hole in the coating 26 to expose the surface of region 22 b of the switching transistor. Advantageously, the etching is anisotropic reactive ion etching (RIE) to form a relatively narrow vertical hole 33 with straight vertical side walls, as seen in FIG. 2 to use only a limited portion of the chip surface.
[0019] After the photoresist is removed and there has been appropriate cleaning of the surface 21 of the chip 20 , the contact hole is partially filled with a conductor, typically polysilicon, to form a plug 34 that makes a low resistance connection to the region 22 b as seen in FIG. 3. The height of the plug preferably should be sufficient that the capacitor can be largely formed enough above the surface to little interfere with other conductors in the dielectric layer.
[0020] To form the plug 34 , it is generally the practice to overfill the contact hole, and if required to use chemical mechanical polishing (CMP) to planarize the surface, and then form a recess 33 in the polysilicon fill by suitable etching, typically isotropic dry etching, to reach the result shown in FIG. 3.
[0021] Next, isotropic etching, typically by suitable wet chemistry or chemical downstream etching, is employed to widen the recess or contact hole 33 to the essentially cup shaped opening 35 , as shown in FIG. 4. As used herein, essentially cup-shaped is intended to include a substantially cylindrical shape. If desired, and extra step may be added to bring the top surface of the poly plug 34 to the same level as the bottom of the widened trench.
[0022] As is shown in FIG. 5, a conductive barrier layer 36 is formed over opening 35 and then there is deposited conformally over the cup-shaped surface of the contact hole a metallic layer 37 suitable for use as the first plate of the capacitor. After the deposition, this metallic layer 37 and the barrier layer 36 are cleaned off where it is not desired, such as the top surface of dielectric coating 26 , to confine the layer to the interior of the contact hole. Typically the cleaning is done by a choice of ion-beam etching (IBE), chemically assisted IBE, or reactive IBE. Advantageously, such etching is done with the ions making a glancing angle with the top surface of the dielectric coating 26 to limit exposure of the side walls and bottom of the contact hole to the ion-beam, as is shown in FIG. 5. An angle of incidence of about 70° of the beam with respect to the surface normal of the wafer insures that there is insignificant etching of the capacitor plate material or barrier layer in the contact hole.
[0023] As previously discussed, it is advantageous to include the conductive barrier layer 36 , either over only the top of the plug or over the entire open surface as shown, before depositing the first layer 37 that serves as the lower plate of the capacitor.
[0024] Next, there is deposited conformally over the metal layer 37 a layer 38 of a material suitable for the capacitor dielectric, preferably barium strontium titanate because of its favorably high dielectric constant. Similar high dielectric constant materials should also be feasible.
[0025] To complete the capacitor and arrive at the structure of FIG. 6, a metal, again preferably platinum, is conformally deposited over the dielectric covered surface of the trench to form a layer 39 that serves as the second (upper) plate of the capacitor. The cup-shaped capacitor of the present invention is shown in FIG. 6.
[0026] Typical dimensions of the capacitor are as follows: The width of the hole is between 100 and 500 nanometers and the ratio of the depth to the width is typically between 2 and 3, although it may be chosen in a range between 0.5 and 5.0, largely depending on the space available.
[0027] Moreover as mentioned earlier, the dielectric layer 38 and the outer metal layer 39 can each be a continuous layer to serve as the capacitor dielectric and outer electrode of all the storage capacitors of a certain array.
[0028] It is to be understood that the exemplary memory cell described is merely illustrative of the general principles of the invention. Various other embodiments are feasible consistent with the spirit and scope of the invention. In particular, materials other than those mentioned may be used. For example, other conductors such as iridium, tantalum, ruthenium, ruthenium oxide, copper, and aluminum might be used for the capacitor layers.
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A semiconductor memory cell includes a field effect transistor coupled to a storage capacitor that formed as a multilayer stack over the surface of the silicon chip of the cell. The capacitor is formed by three conformal layers over the surface of a cup-shaped contact hole in a silicon oxide layer overlying the surface of the chip.
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SUMMARY OF THE INVENTION
This invention relates to a power unit for converting a multi-directional input such as oscillatory or recipricatory motion into a uni-directional output rotation.
The invention utilizes a unique coupling between coaxial input and output shafts wherein a slotted toroidal tubular driven member is caused to rotate by frictional drive members within the tube. The drive members are shifted to contact the inner walls of the tube on opposite sides at alternate times depending upon the direction of rotation of the drive means. This results in a smooth transition of alternate rotary motion into uni-directional rotary motion.
The term "frictional" is not intended to be limited to the contact of drive surfaces but also to include magnetic or hydraulic interaction between surfaces adapted for that purpose.
A wide variety of motion conversion devices have been shown and described in prior publications and patents. One such device is the subject of U.S. Pat. No. 3,666,063 issued May 30, 1972 to Schoeman et al. This device utilizes conventional uni-directional clutches alternately operable to provide uni-directional output from a multi-directional input.
The uses to which such a motion converter may be put are many and varied and a number of examples appear in the above cited U.S. Patent, Column 1, paragraph 3, lines 15-26 and the same is hereby incorporated by reference. Obvious uses include the conversion into rotational power of the energy of the rise and fall of water, for example, and the motion of certain pedal operated vehicles.
In the present invention the multi-directional torque of an input shaft is transferred to a plurality of stub shafts pivoted in toward the input shaft or out away from the input shaft, depending on the direction of rotation. On the outboard end of each of these shafts is a frictional drive member. The frictional drive members are enclosed within a toroidal driven member attached to the output shaft. The drive members are tilted inwardly or outwardly depending upon the direction of rotation of the input shaft and in the inward position contact the inner portion of the driven member and in the outer position contact the outer portion of the driven member. This action results in the driving of the driven member in a uni-directional manner.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS
FIG. 1 is a plan view of the device according to the invention partly in section and with parts broken away for clarity;
FIG. 2 is a schematic representation of a view taken along line II--II of FIG. 1;
FIG. 3 is a view similar to that in FIG. 2 with parts in an alternative position;
FIG. 4 is a cross-sectional view of a portion of the device taken along line IV--IV; and
FIG. 4a is an enlarged detail of the portion shown in FIG. 4.
DETAILED DESCRIPTION
FIG. 1 on the drawing illustrates an embodiment of the invention wherein the overall apparatus is indicated generally by the numeral 10. In this embodiment, an input shaft 12 is shown mounted in a frame 13 coaxial with a driven member 14 and a plurality of intermediate drive assemblies represented by 16 and 17. Driven member 14 is shown as a hollow toroidal flywheel mounted on the output shaft 18 which is also coaxial with shaft 12. Shafts 12 and 18 are mounted for rotation in frame 13 by bearings 15,15' respectively.
Each of the drive assemblies 16 and 17 are pivotal between inner and outer positions limited by a pin 19. Power from rotation of shaft 12 is imparted to shaft 18 by means of a transmission including bevel gear 20 which meshes with pinions 22,24 on stub shafts 23,25. Drive members 21,21', shown here as spherical wheels, are attached to stub shafts 23,25 and these wheels are captive within the flywheel driven member 14. Each of the stub shafts 23,25 are journaled in bearings as shown at 34,36 and pivotal about a spherical bearing such as 26.
A reversing mechanism 30 is mounted on the inner end of input shaft 12 and is connected to drive assemblies 16,17 by means of pivotal joints or hinges 32 between elements of arms 31 and the arms are centrally connected by a connecting pin 33 which is slidably fitted within respective ends of arms 31. Mounted on the outer end of each of stub shafts 23,25 are spherical drive members 21,21'. The reversing mechanism 30 causes motion of the drive assemblies and their respective stub shafts inwardly and outwardly as shown by the arrows in FIG. 1.
Outward movement of the drive assemblies 16,17 will cause spherical drive wheels 21,21' to engage the inside surface of flywheel 14 at point A and inward movement will cause engagement at point B, as shown by the arrows in FIG. 1 with respect to drive wheel 21'. The inward and outward movement of arms of drive assemblies 16,17 is caused to occur automatically upon change of direction of rotation of shaft 12 by means of a reversing mechanism such as that indicated at 30.
Reversing mechanism 30 is channeled to receive pins 35 which are attached to arms 31. (see also FIGS. 2, 3, 4 and 4a) Fitted within the channel in mechanism 30 are a plurality of baffle members 28 which may be moved from the solid line position indicated at 28 to the dotted line position 28' against the bias of springs 27 acting on limiting pins 29.
Clockwise rotation of mechanism 30 as shown in FIG. 4 will cause pins 35 to be confined to an outer path by baffles 28 and counter clockwise rotation will cause the pins to move to an inner path against springs 27.
Counterclockwise rotation will thus result in inward movement of drive wheels 21,21' to contact surface b of flywheel 14 as seen in FIG. 2 with respect to wheel 21. Clockwise rotation will result in outward movement of drive assemblies 16, 17, and drive wheels 21, 21' will make drive contact at point a as shown in FIG. 3. In either instance clockwise rotation of flywheel 14 results.
The drive wheels 21,21' preferably comprise a coating 38 of flexible, resilient material bonded to hubs 40 which are removably attached to stub shafts 23.
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Apparatus for converting multi-directional input to uni-directional output having a plurality of drivers rotated by the input and moveable to alternate positions with respect to opposed surfaces on the output driven member for frictional drive of the driven member. The drivers are moved to alternate positions automatically upon change of direction of the input.
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CLAIM OF PRIORITY
[0001] This application claims priority from U.S. application Ser. No. 11/533,400 entitled “Stackable, Nestable, and Gangable Table,” which was filed on Sep. 20, 2006 and issued as U.S. Pat. No. 7,849,804 on Dec. 14, 2010, which has at least one common inventor and is hereby expressly incorporated by reference.
FIELD OF THE INVENTION
[0002] This invention relates generally to the field of tables and more particularly to wire tables that can be nested, stacked or ganged.
BACKGROUND OF THE INVENTION
[0003] For many facilities such as schools, hotels, convention centers, churches, and offices it is desirable to utilize rooms and spaces in an efficient manner. At different times, these facilities will often need to use the same space for different purposes. Some activities require the use of furniture such as tables or desks, while at other times, furniture is not needed. These facilities will often move, rearrange, or eliminate the furniture in a room according to the needs of the event. In many instances, these facilities utilize desks or tables for such events as training, test administering, lectures, speeches, conventions, etc. When the furniture is not in use at these facilities it is desirable to minimize the floor space required to store these items.
[0004] The desire to utilize spaces for different activities also presents the need to arrange furniture for various applications. Very often, arranging the furniture is cumbersome, time consuming and labor intensive. Similarly, providing an aesthetically pleasing arrangement often requires additional time, effort, and labor.
[0005] The tables and desks used in these facilities come in many varieties adapted for many uses. In an effort to reduce the floor space required for storage, some tables and desks are stackable, nestable or gangable, while some are collapsible. One type of nestable table is represented in U.S. Pat. No. 3,326,148 to Jakobsen. This table includes a table top supported by four legs. The distance between one pair of legs is greater than the distance between another pair of legs to accommodate the nesting of the tables when stacked one on top of the other. The tables also include a glide extending along two opposite edges of the table to create a gap between each stacked table to facilitate separation of the stacked tables. Another example, U.S. Pat. No. 6,085,669 to Marchand et al., depicts a table top hinged to a frame of which the legs of the table are also attached. This hinge allows the table top to be rotated to a vertical position to accommodate a horizontal nesting of the tables.
[0006] Such tables provide a marginal space savings when stored. Such tables are often heavy and difficult to move or arrange. This presents problems for the facility that needs to provide accommodating facilities with a minimal investment of time and labor.
[0007] There is a need, therefore, for a stackable table that can accommodate a multitude of uses and which can be arranged and moved with minimal effort and time required. There is also a need to provide an aesthetically pleasing arrangement without requiring extra time and labor. Optimally, the table would be simple to maneuver and arrange. There is a further need for a stackable table that encumbers minimal floor space while in storage.
SUMMARY OF THE INVENTION
[0008] In order to address these needs, the present invention provides a stackable, nestable and gangable table which includes a work surface and a modesty panel supported by a wire frame base. The frame, work surface and modesty panel are configured so that a plurality of like-configured tables may be stacked and/or nested. The modesty panel is angled vertically from the top surface, such as at 92 degree angle in one specific embodiment. This angle allows for stability when the tables are nested and stacked together. The work surface may contain a recessed area to provide a “spill proof” or “spill resistant” design.
[0009] In another aspect of the invention, the wire frame defines one or more openings that are configured to allow accessories to mount within the opening. In one embodiment of the invention, the accessory mounted into the opening is a pouch carrier or receptacle that provides storage space for items while leaving the work surface unencumbered. The pouch includes a frame with the receptacle secured to the frame and a cantilever mounting arm that is configured to mount within the opening on the table. The accessory frame is configured so that the accessory, such as the pouch, may be situated between adjacent ganged tables without interference.
[0010] In yet another aspect of the invention, glide members may be attached to the base of the table. In a specific embodiment, the glide members include a portion that is generally trapezoidal in shape which form a “dovetail” joint when juxtaposed with another glide member when adjacent tables are ganged together. The glide members not only facilitate ganging of the tables, they also prevent relative movement between adjacent tables.
[0011] It is one object of the invention to provide a wire table that may be nested and/or stacked. A further object is to provide such a table that includes not only a work surface but also a modesty panel.
[0012] A further object resides in features of the invention that allow for various accessories to be removably supported on the gangable and/or stackable table. This object is beneficially achieved while avoiding interference between the accessories and an adjacent ganged table.
[0013] One significant benefit of the present invention is that it provides a wire table that is easily stacked and/or ganged. Other objects and benefits of the invention will become apparent upon consideration of the following written description and accompanying figures.
BRIEF DESCRIPTION OF THE DRAWINGS
[0014] FIG. 1 is a front perspective view of a wire frame table according to one embodiment of the present invention.
[0015] FIG. 2 is a top view of the wire frame table shown in FIG. 1 .
[0016] FIG. 3 is a top view of a further embodiment of the wire frame table shown in FIG. 1 .
[0017] FIG. 4 is a front perspective view of three wire frame tables stacked and nested according to one embodiment of the invention.
[0018] FIG. 5 is a front view of the wire frame table shown in FIG. 1 .
[0019] FIG. 6 is a top view of a glide member used with the table shown in FIG. 1 .
[0020] FIG. 7 is a cross-sectional view of the glide member shown in FIG. 6 .
[0021] FIG. 8 is a cross-sectional view of the wire frame where the glide member shown in FIG. 6 attaches.
[0022] FIG. 9 is a top view of three wire frame tables ganged according to one embodiment of the invention.
[0023] FIG. 10 is a front perspective view of three wire frame tables ganged according to one embodiment of the invention.
[0024] FIG. 11 is a side perspective view of the carrier pouch accessory for use with table shown in FIG. 1 .
[0025] FIG. 12 is a top perspective view of the carrier pouch shown in FIG. 11 .
[0026] FIG. 13 is a front perspective view of two ganged tables of the present invention and the receptacle pouch shown in FIG. 11 .
[0027] FIG. 14 is a side perspective view of the carrier pouch shown in FIG. 11 .
[0028] FIG. 15 is a cross-sectional view of a snap fit arrangement between the modesty panel and modesty panel support bar according to one embodiment of the wire table of the present invention.
[0029] FIG. 16 is a front view of an alternative embodiment of the table of the present invention.
[0030] FIG. 17 is a front view of another alternative embodiment of the table of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0031] For the purposes of promoting an understanding of the principles of the invention, reference will now be made to the embodiments illustrated in the drawings and described in the following written specification. It is understood that no limitation to the scope of the invention is thereby intended. It is further understood that the present invention includes any alterations and modifications to the illustrated embodiments and includes further applications of the principles of the invention as would normally occur to one skilled in the art to which this invention pertains.
[0032] A stackable table 10 in accordance with one embodiment of the invention is depicted in FIG. 1 . The table 10 may be used in a variety of facilities such as a classroom, conference room, church, or convention center to meet a variety of needs. The table 10 includes a wire frame base 12 of generally u-shaped construction to provide chair access and leg space within the frame. The wire frame base may be constructed from any wire or rod material, but is preferably of a 7/16 inch wire stainless steel or aluminum. The wire frame base 12 has a floor-engaging frame 12 ′ that includes two base side bars 14 , each connected at a first end 13 to a longitudinal back bar 16 to form a U-shape as shown in FIG. 1 . Attached at a second end 15 of each side bar 14 is a front vertical support rod 24 which extends vertically upward. Each front vertical support rod 24 extends to approximately the height of the desired work surface or table top 32 . A front cross member 26 (shown best in FIG. 2 ) may be provided which spans between the two front vertical support rods 24 . Many heights of the table top 32 are contemplated, but in a preferred embodiment the height of the work surface is approximately 27-29 inches. In an alternative embodiment, a standard bar height may be approximately 42 inches as shown in FIG. 16 . FIGS. 16 and 17 show alternative embodiments of the wire frame table 10 ′, 10 ″ of the present invention including different configurations of the wire frame base 12 ′, 12 ″, the modesty panel 36 ′, 36 ″ and of the height of the table top 32 ′, 32 ″. In one embodiment, the front cross member 26 is sized to provide a leg space between the vertical rods that is slightly larger than a typical stackable chair, an example of which is depicted in U.S. Pat. No. 6,722,735 to Lucci et al.
[0033] Two back vertical support rods 28 are attached at one end 27 to the longitudinal back bar 16 . These back vertical support rods 28 extend vertically upward from the longitudinal back bar 16 and are spaced from the front cross member 26 to accommodate the depth of a table top 32 , with or without a modesty panel 36 . The back vertical support rods 28 extend vertically upward and are each connected to an upper side bar 30 . In one embodiment, the back vertical support rods 28 and the top side bars 30 are formed from the same length of wire material. The joint may be formed by bending the wire material at approximately an angle A of about 92 degrees. The upper side bars 30 may then be joined at the other end to the front cross member 26 by means of brazing, welding, bolting, or any other suitable joining method known in the art. As seen in FIG. 2 , the upper side bars 30 join the front cross member 26 inboard from the base side bars 14 and vertical rods 24 .
[0034] It should be noted that in a preferred embodiment, the joints of the wire members can be formed from bending the wire material. Thus, the wire frame base 12 , front vertical support rods 24 and front cross member 26 may be formed from a single piece of wire material that has been formed by bending the wire into the desired skeleton.
[0035] FIG. 4 shows three stackable tables 10 A, 10 B, and 10 C in a stacked and nested configuration suitable for storage. As is apparent from the figure, the tables may be stacked with the respective table tops 32 and modesty panels 36 in contact with each other. The tables may be stacked and nested in the following manner: A top table 10 B is positioned adjacent a bottom table 10 A by moving the top table 10 B over the bottom table 10 A. The front vertical supports 24 of the tables are spaced a distance W 1 ( FIG. 2 ) such that they pass around the back vertical supports 28 of the adjacent table which are spaced at lesser distance W 2 . The top table 10 B is then moved forward until the frame members nest as shown in FIG. 4 with the base side bars 14 and back bars 16 resting on each other. The distance between the front vertical support rods W 1 is greater than the distance between the back vertical support rods W 2 which allows for the stackability/nestability of the tables as depicted in FIG. 4 .
[0036] In a particular embodiment, the table top 32 is of generally rectangular construction as shown in FIG. 2 to provide a usable work surface for the table. In one embodiment, the table top 32 may incorporate a slightly recessed surface 34 for containing or retaining pens and pencils on the table top, as illustrated in FIG. 3 . Similarly, grooves for holding pens/pencils (not shown) or grooves/holes for holding drinking cups (not shown) may be formed into the table top in any suitable manner known in the art, so long as the stackability/nestability of the tables is not impaired. The table top has any depth suitable for a particular use. In one embodiment, the depth of the table top 32 is approximately 19 inches; however, alternative depths are also contemplated by this invention.
[0037] In another feature of the invention, a modesty panel 36 of generally rectangular construction is disposed between the back vertical support rods 28 as shown in FIG. 1 . This invention contemplates many lengths of the modesty panel 36 . In one embodiment, the modesty panel 36 extends down from the table top 32 toward the longitudinal back bar 16 , or may extend a shorter distance. According to convention, the modesty panel 36 may extend approximately eight inches from the table top 32 . Like the support rods, the modesty panel 36 is also angled slightly to provide stability when the tables are stacked/nested as shown in FIG. 4 . In one embodiment, the angle between the table top and the modesty panel A is approximately 92 degrees, though other angles are acceptable.
[0038] In one embodiment, the table top 32 and modesty panel 36 are of unitary construction. The unitary top/panel 32 / 36 may then be snap fit into place at a channel 37 shown in FIG. 15 , on the edge of the unitary panel that fits the tubular material of the vertical supports 28 and side bars 30 . If the modesty panel 36 does not extend to the longitudinal back bar 16 , a modesty panel cross bar 38 (shown in FIG. 1 ) may be utilized with the snap fit design. The modesty panel cross bar 38 could be made from the same wire material and span the width of the two back vertical supports 28 such that the bottom of the modesty panel 36 can engage the cross bar 38 . Other methods of joining the table top 32 and modesty panel 36 to the frame 12 are contemplated including any suitable means known in the art such as welding, riveting, gluing, etc.
[0039] In order to enhance the fixation of the table top 32 to the wire frame of the table, at least one of the back vertical supports 28 and the associated upper side bar 30 may be canted inward at a slight angle so that the distance between the opposite upper side bars 30 decreases slightly from the front of the frame to the back. When the table top is positioned between the upper side bars 30 and back vertical supports 28 , the one back vertical support must be pushed outward enough for the table top 32 to fit between the bars. The natural spring resistance of the canted back vertical support will help hold the table top in position.
[0040] Alternatively, both back vertical supports 28 and associated upper side bars 30 may be canted inward from the vertical front-back plane. With this configuration, the table top 32 will have a slightly trapezoidal shape from front to back. In a specific embodiment, the inward cant may be at an angle of about 89 degrees.
[0041] In another feature of the invention the wire table defines an accessory opening 42 by joining an accessory bar 40 to the front vertical support rods 24 as shown in FIGS. 1 and 5 . It can be appreciated that the accessory opening 42 could be constructed on either side of the table, or both. The accessory bar 40 is spaced apart from the front vertical support rod 24 so as to define the opening 42 for mounting accessories. In one embodiment, the opening 42 is formed as an elongated slot, although other shapes of openings may be contemplated. The accessory opening 42 as shown in FIG. 5 can be used to support a hanging bracket 62 by means of a cantilever arm 60 , as illustrated in FIGS. 11-12 , which will be described in more detail later herein.
[0042] In a further feature, the table 10 may include glide members 44 that support the table while providing a ganging capability. The glide members 44 are located on the wire frame base 12 as shown in FIG. 1 . In a preferred embodiment, two glide members 44 are spaced apart on each side bar 14 of the wire base frame 12 . As shown in the detail views of FIGS. 6-8 , one portion 41 of the glide members 44 is configured for mounting to the side bar 14 by at least partially wrapping around the geometry of the side bar 14 . In one embodiment, where the wire frame base 12 is of a wire construction, the glide member 44 is configured to receive the wire frame in a channel 46 sized to receive the wire material.
[0043] In another embodiment, a secondary mechanism may be employed for securing the glide member 44 to the side bar 14 . For instance, one embodiment uses a screw 43 inserted through a hole 51 in the side bar 14 at the desired locations for positioning of the glide members, as shown in FIG. 8 . The channel 46 of the glide member 44 thus includes a portion 46 a to receive the side bar 14 , and a portion 46 b configured to receive the screw 43 , as shown in FIGS. 6 and 7 . The screw 43 helps position the glide member 44 on the frame and hold the glide member 44 in place during use. If the glide member 44 becomes worn or damaged it can be easily removed and replaced. In alternative embodiments, the screw 43 may be a spring pin that is initially depressed to mount the glide member 44 on the frame.
[0044] The second portion 45 of the glide member 44 is of a generally trapezoidal configuration. This shape provides a unique advantage when two or more tables are ganged together. In order to take advantage of the configuration of the portion 45 , the glide members 44 are located at offset positions on the opposite side bars 14 such that when two or more tables are placed side by side, as shown in FIG. 9 , the glide members 44 perform not only a spacing function, but also function to hold the consecutive tables in relative position. That is, the glide members 44 are located such that when two tables are placed next to each other, the angled edges 49 of the trapezoid shape 45 juxtapose to form a “dovetail” joint 47 . The alignment of the glide members 44 as depicted in FIG. 9 is such that the glide members 44 b attached to side bar 14 b (of the second table 10 b ) are offset relative to the glide members 44 a attached to side bar 14 a (of the first table 10 a ). Similarly, the glide members 44 c attached to side bar 14 c are offset relative to those attached to side bar 14 b . In a preferred embodiment, the glide members are arranged so that the glide members on side bar 14 a surround the glide members on the juxtaposed side bar 14 b.
[0045] This feature provides many advantages. First, the glide member 44 works to evenly space each table 10 apart from the next when the tables are ganged in rows as shown in FIG. 10 . Similarly, the engagement of the glide members 44 to one another prevents the tables from skewing. The “dovetail” joint 47 formed by the adjacent glide members 44 , provides an aesthetically pleasing arrangement for several tables with minimal effort. In one embodiment, the glide members are formed from a polycarbonate, but many suitable materials are contemplated by this invention.
[0046] As alluded to above, another feature of the table 10 is the side storage carrier or pouch 48 , illustrated in FIGS. 11-14 , that is configured to receive books, folders, or other supplies that might otherwise clutter the table top 32 . In one embodiment, the side storage receptacle pouch 48 is formed from a wire frame 50 . The wire frame 50 is of a generally rectangular construction and is preferably sized such that when the tables 10 are ganged, the wire frame 50 will fit inside the space between the table tops 32 as shown in FIG. 13 . A rectangular piece of material 54 , preferably of a knit or woven mesh, is secured to the longitudinal edges 52 , 53 of the wire frame 50 forming a pouch 56 sized to receive books, folders, training materials, etc. In one embodiment, the longitudinal edge 53 of the wire frame 50 that is disposed farthest from the table top 32 is elevated with respect to the other longitudinal edge 52 . It can be appreciated that when tables 10 are grouped together in rows, this raised edge 53 will help delineate the workspace or personal space for each table 10 as shown in FIG. 13 .
[0047] As best seen in FIG. 14 , the wire frame 50 terminates at a lateral edge 58 in a cantilever arm 60 . In a preferred embodiment, the ends 55 of the wire frame 50 are formed into the arm 60 from a continuous piece of material, such as a steel or aluminum tube. In an alternative embodiment, the arm 60 may be attached to the wire frame 50 of the side storage pouch 48 by any suitable method. The arm 60 is connected or attached to a hanging bracket 62 that is used to support the arm 60 on the wire table 10 . The hanging bracket 62 is generally elongated, as shown in FIG. 13 , with an oval member 64 that is configured to be received into the accessory opening 42 of the table 10 . In a preferred embodiment, the oval member 64 defines a groove 66 formed on the outside perimeter 68 . This groove 66 is deeper at the top end 70 than at the bottom end 72 of the oval member 64 . The differences in the depth (D 1 , D 2 ) of the groove 66 allows the hanging bracket 62 to be easily mounted into or removed from the accessory aperture 42 with no tools. To mount the hanging bracket 62 , and thus the accessory 48 attached to it, the top end 70 of the oval member 64 is inserted into the accessory opening 42 . The hanging bracket 62 is then angled into place as shown in FIG. 12 , and the bottom end 72 of the oval member 64 is seated on an edge of the accessory bar 40 with the weight of the accessory holding it in place. Reversal of this procedure allows for removal. It can be appreciated that other accessories, such as shelves, partitions, storage bins, etc, may be used with the hanging bracket 62 .
[0048] While the invention has been illustrated and described in detail in the drawings and foregoing description, the same should be considered as illustrative and not restrictive in character. It is understood that only the preferred embodiments have been presented and that all changes, modifications and further applications that come within the spirit of the invention are desired to be protected.
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A stackable, nestable, and gangable table for use in varied environments such as classrooms, conferences, testing, etc includes a wire frame scaled according to the anticipated use, a table top and a modesty panel angled obtusely from the table top to accommodate stacking and/or nesting of the tables. The table further includes glide members on the wire frame base that accommodates the ganging of tables next to one another. The glide members are mounted on the base in such a manner that they engage the opposing glides on the aligned consecutive table. The table also includes a mounting mechanism for mounting accessories such as a side storage pouch to provide additional storage and help delineate the personal work space of each table.
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TECHNICAL FIELD
The invention relates generally to fluid membrane separation using fiber membrane technology. In particular, the present invention relates to a boreside feed gas separation membrane module comprising membranes with discrete flow channels to allow for permeation based on separation of gases.
BACKGROUND OF THE INVENTION
A variety of devices for separating fluid mixtures with hollow fiber membranes have been described. See for example, U.S. Pat. Nos.: 4,961,760; 4,929,259; 5,000,763; 5,013,331; 5,013,437; 5,071,552; 5,160,042; 5,282,964; 5,702,601; 5,284,583 and 5,779,897.
Typically, the separation process is carried out in a module fabricated from semi-permeable membranes. Such membrane separations are based on relative permeabilities of various components of the fluid mixture, resulting from a gradient of driving forces, such as pressure, partial pressure, concentration and temperature. Such selective permeation results in the separation of the fluid mixture into retentate, i.e. slowly permeable components, and permeate portions, i.e. faster migrating components.
In boreside feed processes the feed fluid is introduced into the open bores of the hollow fibers and one or more components permeate through the walls of the hollow fibers into the region outside the fibers. The fluid which selectively permeates through the fiber membrane wall is removed from the shellside of the membrane, while the non-permeable fluid is removed from the non-permeate region.
Obtaining proper flow and distribution of the permeate fluid on the shellside of the fibers is a problem associated with boreside feed. During separation, the high permeate flow rate may result in excessive shellside pressure drops. Additionally, the uncontrolled flow of the permeate fluid on the shellside of the membrane may cause localized areas of high concentration or partial pressure of the permeate fluid, thus resulting in inefficient or ineffective separation of the fluid mixture.
The efficiency of the fluid separation process is determined by the properties of fluid mixture, the membrane material and its structure. The productivity of the membrane device is proportional to the surface area of the membrane material packed in the device, while the separation efficiency of the device inversely depends on the thickness of the membrane material. Generally this is achieved by providing the membrane as hollow fibers of substantial length and small diameter, arranged parallel to one another. However, decreasing the diameter of the long fibers can result in increased back pressure. The efficiency of separation drops further with the use of thinner capillaries or with highly permeable capillaries with asymmetric wall structures. Other methods to decrease the shellside pressure drop, such as larger fiber size, shorter device length and decreased fiber packing density result in increased cost and/or decreased module productivity.
Therefore, current membrane devices containing long hollow fibers with small diameters are costly and inefficient when the pressure drop is large and thus not commercially viable for meeting current uses. Thus, there is a need for improved and cost-effective devices comprising fiber membranes that are capable of operating at acceptable levels of separation productivity.
SUMMARY OF THE INVENTION
The present invention defines a boreside feed gas separation membrane device containing primarily hollow fiber membranes with discrete flow channels incorporated into the bundle to allow for pressure removal of the permeate gas collected on the shellside of the device. The flow channels minimize pressure drop and/or the build-up of back pressure on the shellside of the device while maintaining proper counter-current flow patterns in the device. The incorporation of flow channels results in improved efficiency of the device, especially for feed streams or membrane types that lead to high permeate flow rate that result in excessive shellside pressure drops.
In one aspect, the invention relates to a hollow fiber membrane fluid separation device adapted for boreside feed, wherein the device comprises:
(a) a plurality of elongate hollow fiber membranes adapted for separation of one or more fluids from a fluid mixture, wherein the membranes are arranged in a bundle having a first end and a second end;
(b) a first tubesheet having an inner face and an outer face and arranged at the first end of the bundle, wherein the hollow fiber membranes extend through the first tubesheet and are open at the outer face thereof;
(c) a second tubesheet having an inner face and an outer face and arranged at the second end of the bundle, wherein the hollow fiber membranes extend through the second tubesheet and are open at the outer face thereof;
(d) a core about which the bundle of hollow fiber membranes is arranged, wherein the core extends through and is attached to said first and second tube sheets;
(e) a plurality of elongate permeate flow channels arranged in spaced-apart relation to each other within the bundle and extending from the first end to the second end of the bundle, wherein the flow channels are embedded in the first and second tubesheets, and further wherein the flow channels are sealed at the outer faces of the first and second tubesheets;
(f) an elongate shell having first and second open ends, wherein the bundle, the first and second tubesheets, and the core are encased within the shell and the first tubesheet is arranged at the first end of the shell and the second tubesheet is arranged at the second end of the shell;
(g) a first sealing endcap which is attached, i.e. optionally sealed or removably attached, to the first open end of the shell, wherein a feed inlet region is established between the endcap and the outer face of the first tubesheet;
(h) a feed inlet for introducing into the feed inlet region a fluid mixture to be separated into the bores of the hollow fiber membranes;
(i) a second sealing endcap which is attached, i.e. optionally sealed or removably attached, to the second open end of the shell, wherein a non-permeate outlet region is established between the second endcap and the outer face of the second tubesheet;
(j) an outlet for removing from the non-permeate outlet region fluid from the mixture which does not permeate from the hollow fiber membranes;
(k) first and second sealing means which respectively seal the first and second tubesheets against the shell, thereby defining a permeate outlet region between the shell and the outside of the bundle; and
(l) a permeate outlet means for removing fluid which permeates from the hollow fiber membranes into the permeate outlet region.
In a preferred embodiment, the permeate flow channels are arranged uniformly within the bundle such that counter-current flow performance can be maintained during fluid separations. In a more preferred embodiment, the permeate flow channels are arranged at the interfaces between adjacent concentric membrane layers. In a most preferred embodiment, the permeate flow channels are arranged in the bundle as a series of concentric rings which encircle the core.
In an alternative embodiment, the device as described above, comprises a coreless design, wherein the bundle of hollow fiber membranes is arranged around an axially oriented hollow channel. In another preferred embodiment, a plurality of hollow fiber membrane bundles comprising permeate flow channels as described above, are assembled in a single shell as described in U.S. Pat. No. 5,282,964.
In another embodiment, the device further comprises a sweep inlet means for introducing a sweep fluid into the permeate outlet region.
In a preferred embodiment, the fluid mixture comprises a mixture of gases. Preferably the gas mixture comprises a gas selected from the group consisting of hydrogen, oxygen, helium, nitrogen, carbon monoxide, and carbon dioxide.
The invention device yields high-purity non-permeate product stream, while improving productivity and recovery of the process. Additionally, the invention is cost-effective, easy to manufacture and can be easily adapted for a wide range of productivity requirements.
These and other embodiments of the present invention will readily occur to those of ordinary skill in the art in view of the disclosure herein.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 illustrates a sectional view of the membrane separation device according to one embodiment of the invention.
FIG. 2 illustrates a sectional view of the membrane separation device according to another embodiment of the invention for carrying separations utilizing sweep fluids.
FIG. 3 illustrates a cross-sectional view of the membrane device shown in FIG. 1.
DETAILED DESCRIPTION
The practice of the present invention will employ, unless otherwise indicated, conventional techniques of chemistry and engineering which are within the skill of the art. Such techniques are explained fully in the literature. Kesting, R. E., Synthetic Polymeric Membranes, John Wiley & Sons, 2 nd Ed. (1985); Hwang, Sun-Tak and Kammermeyer, Karl, Membranes in Separation, Robert E. Kriegar Publishing Co., Inc., (1984).
All patents, patent applications, and publications mentioned herein, whether supra or infra, are hereby incorporated by reference in their entirety.
It must be noted that, as used in this specification and the appended claims, the singular forms "a", "an", and "the" include plural referents unless the content clearly dictates otherwise. Thus, for example, reference to "a hollow fiber membrane" includes two or more such membranes and the like.
Membranes of the invention may be homogenous, composite, or asymmetric membranes, as described in U.S. Pat. No 4,874,401. Preferably the membranes of the invention are asymmetric or composite. In addition, the membranes may be shaped in the form of flat sheets, hollow fibers, or hollow tubes.
Although a number of compositions and methods similar or equivalent to those described herein can be used in the practice of the present invention, the preferred materials and methods are described. Therefore, it is to be understood that the terminology and examples used herein are for the purpose of describing particular embodiments of the invention only, and are not intended to be limiting.
The present invention provides a device comprising membrane modules for separating one or more fluids in a fluid mixture into permeate and retentate portions. The fluid mixture may be a mixture of fluids in a gas, vapor, or liquid state. The membrane module comprises an elongated hollow casing and a plurality of flexible hollow fibers of semi-permeable membrane material. The casing encloses a flow pathway and has a pair of opposite ends. The flexible hollow membrane fibers are capable of separating a fluid mixture into permeate and retentate portions. Each hollow fiber has a pair of spaced opposite end portions and an elongated portion extended between and interconnecting opposite end portions.
The hollow fibers can be arranged in various forms such as individual hollow fibers, bundles of hollow fibers, knitted or wefted textiles, and membrane carpets or rugs, including those disclosed in Mahon, U.S. Pat. No. 3,228,876 and McLain, U.S. Pat. No. 3,422,008. Preferably the bundle is arranged in a substantially non-random organized manner. In a preferred embodiment, the bundle is elongated and arranged in a cylindrical fashion with the ends of the hollow fibers located at each end of the cylindrical bundle. Preferably, the hollow fibers in the bundle are arranged in either a parallel wrap fashion, wherein the hollow fibers lie substantially parallel to one another with each end of the hollow fibers found at each end of the bundle. In an alternative embodiment, the hollow fibers in the bundle are wrapped in a bias wrap fashion, wherein the hollow fibers are wrapped in a crisscross pattern at a set angle, thus holding the hollow fibers in place in a bundle. In a preferred embodiment, the number of fibers in a bundle range from 0.1 to 5 million, preferably from 1-2 million and most preferably from 1 to 1.5 million; wherein the outer diameter of the fiber ranges from 100 to 500 microns, preferably from 100 to 300 microns, and most preferably from 100 to 200 microns; the outer diameter of the bundle arranged as concentric circles ranges from 1 to 15 inches, preferably from 7 to 12 inches, and most preferably from 8 to 10 inches; and the packing density of the fibers within the bundle ranges from 30 to 70%, preferably from 40 to 65% and most preferably from 50 to 60%. The packing density is defined as the fraction of the cross-sectional area of the module occupied by the hollow fibers, wherein the cross-sectional area is based on its internal diameter and the cross-sectional area of the hollow fibers is based on their outer diameter.
The hollow fiber membranes are generally formed from a semi-permeable polymeric material, preferably olefinic polymers, such as poly-4-methylpentene, polyethylene, and polypropylene; polytetrafluoroethylene; cellulosic esters, cellulose ethers, and regenerated cellulose; polyamides; polyetherketones and polyetheretherketones; polyestercarbonates; polycarbonates, including ring substituted versions of bisphenol based polycarbonates; polystyrenes; polysulfones; polyimides; polyethersulfone; and the like. The hollow fiber membranes may be homogeneous, symmetric, asymmetric, or composite membranes. The membranes may have a dense discriminating region wherein the separation of the fluid mixture is based on differences in solubility and diffusivity of the fluids; or the membranes may be microporous wherein the separation is based on relative volatilities of the fluids. Preferably the membranes are asymmetric fibers as described in U.S. Pat. No. 4,955,993. The methods for preparing such hollow fiber membranes are well known in the art. (See, for example, U.S. Pat. No. 4,961,760).
A tubesheet is arranged around each end of the bundle, such that the hollow fiber membranes extend through the tubesheet and are open at the outer surface thereof. The tubesheet provides a support, holding the hollow fiber membranes in place and separates the membrane device into three different regions: (1) the feed inlet for the introduction of fluid mixture to be separated into the hollow fiber membranes; (2) the region between the tubesheets wherein a portion of the boreside fed fluid permeates across the hollow fiber membranes onto the shellside of the hollow fiber membranes; and (3) the non-permeate outlet region from which the retentate fluid is removed. The tubesheet is comprised of a thermoset or thermoplastic resinous material capable of forming a fluid-tight seal around the hollow fiber membranes, and optionally capable of bonding to the core and/or the hollow fiber membranes. The face of each tubesheet opposite the bundle is opened such that the bores of the hollow fiber membranes are opened to the region adjacent to each face, thereby allowing communication of fluid from such regions into and out of said hollow fiber membranes. Each tubesheet generally comprises a composite of the hollow fiber membranes embedded in the resinous material. The tubesheet may exist in any shape as desired, as long as it is able to withstand the pressure during operation. In a preferred embodiment, the tubesheet is circular with sufficient cross-sectional area and thickness to provide adequate support for the hollow fiber membranes. The portion of each tubesheet outside of the bundle may be built up for various purposes depending upon the design of the device.
Examples of resinous materials for the tubesheet are described in U.S. Pat. No. 4,961,760, and include artificial and natural rubbers, phenol aldehydes, acrylic resins, polysiloxanes, polyurethanes, fluorocarbons, and epoxy resins. In a preferred embodiment the tubesheet is prepared from epoxy resins. The device may optionally contain an additional tubesheet support means to support the outer edge of the tubesheets and to prevent or reduce bending and compression stresses resulting from the application of pressure on the outside of the tubesheet. The tubesheet support means may be made of any material which provides sufficient support to prevent or reduce the compression and bending stresses on the tubesheet and to prevent the tubesheets from collapsing in on one another. Such materials include high strength plastics such as PVC, composites, and metals such as aluminum and steel.
In one embodiment, the hollow fiber membrane bundle is arranged about a core, wherein the core extends through and is bonded to both the first and second tubesheets. The core provides support for the tubesheets, preventing them from collapsing upon one another during operation. The core also supports the hollow fiber membrane bundle which is arranged about the core. The core comprises a suitable material that possesses sufficient mechanical strength to provide the desired support for the bundle and tubesheets, and can include a rod, a solid tube, a perforated tube, and the like. Such materials include, but are not limited to, plastics such as PVC, a composite material, or a metal. Preferably, the core is comprised of a metal, such as aluminum or steel.
In an alternative embodiment, the device comprises a coreless design, wherein the bundle of hollow fiber membranes is wrapped along a long shaft, and the shaft is subsequently removed such that the bundle is arranged around an axially oriented hollow channel. In another preferred embodiment, a plurality of hollow fiber membrane bundles comprising permeate flow channels as described above, are assembled in a single shell as described in U.S. Pat. No. 5,282,964.
In another embodiment, a sweep fluid is introduced into the permeate outlet region to facilitate the removal of permeated fluids from the shellside of the hollow fiber membranes. The sweep fluid may be introduced through a sweep inlet means, wherein the sweep inlet means are preferably on the core. Alternatively, the sweep fluid may be introduced through a sweep inlet means, a second port located at the opposite end of the module from the feed port, and in communication with the permeate outlet region. In a preferred embodiment, the core tube is solid when it passes through the feed inlet region and non-permeate outlet region, and is perforated in the vicinity of the hollow fiber membrane bundle. In another preferred embodiment, the core is perforated at one end of the portion of the core located between the tubesheets. In one such embodiment, the sweep inlet is located at the opposite end of the module from the fluid mixture feed inlet. In an alternative embodiment, the sweep inlet is located at the same end of the module as the fluid mixture feed inlet.
The membrane device comprises a plurality of permeate flow channels arranged in spaced-apart relation to each other within the hollow fiber membrane bundle and extending from one end to the second end of the bundle, wherein the flow channels may extend through the first and second tubesheets and are sealed and blocked at the outer faces of the first and second tubesheets. The permeate flow channels are arranged in any desirable order and may be embedded within the interior of the hollow fiber bundle. The permeate flow channels may be arranged as concentric tubes parallel to the core; in a spiral fashion beginning at the core and ending near or at the outside of the bundle; or in such a manner that the first and second ends of the flow channel extend into the permeate outlet regions. Preferably, the permeate flow channels are arranged uniformly within the bundle such that the counter-current flow performance can be maintained during fluid separations. In a preferred embodiment, the bundle comprises a series of concentric layers of hollow fiber membranes arranged about the core, and the permeate flow channels are arranged at the interfaces between adjacent concentric membrane layers, such that the permeate flow channels are arranged in the bundle as a series of concentric rings which encircle the core.
In another embodiment, the device comprises a first set of additional flow channels placed perpendicular to the fiber bundle, wherein the additional channels are in proximity of the feed channel and are radially distributed, and preferably are located within the first 0-50% of the overall bundle length, i.e. in the region adjacent to the feed inlet. In an alternative embodiment, the device further comprises a second set of additional flow channels placed perpendicular to the fiber bundle, wherein the second set of additional flow channels are located within 50-100% of the overall bundle length, i.e. in the region at opposite end of the first set of additional flow channels. In another embodiment, the additional flow channels are radially distributed and located perpendicular to the fiber bundle, such that the additional channels are within the first 0-50% of the overall bundle length and terminate in the permeate outlet region. In yet another alternative embodiment, the additional flow channels are located perpendicular to the fiber bundle and are helically distributed, such that the additional channels are within the first 0-50% of the overall bundle length and are in close proximity to the feed channels, wherein the flow channel is at least about 3 to about 115 times the diameter of the membrane fiber, preferably at least about 7 to about 80 times, and more preferably at least about 19 to about 60 times the diameter of the membrane fiber. In an additional embodiment, additional perpendicular channels are optionally located throughout the entire length of the overall bundle to further facilitate fluid sweep efficiency.
The flow channels have an outer diameter ranging from about 500 to 15000 microns; preferably 1000 to 10000 microns; and most preferably 2500 to 7500 microns. The number of flow channels present in the bundle depends on the number required to lower the back pressure sufficiently (0.3 to 5 psig), while maintaining volumetric productivity. Generally, the number of flow channels in a bundle is about one channel per 500 to 500,000 hollow fiber membranes; preferably one channel per 5,000 to 300,000 hollow fiber membranes; and most preferably one channel per 10,000 to 200,000 hollow fiber membranes. Additionally, to maintain efficient counter-current flow performance, it is desirable to place the flow channels uniformly in the hollow fiber bundle. The number of flow channels used, channel spacing and channel size thus depends upon the bundle diameter, fiber packing density, fiber permeability and the bundle length. In general, for high volumetric permeate flow, tight channel spacing and large channel size is necessary. In a preferred embodiment, the flow channels are preferably placed at intervals measured along the bundle diameter from the core of between about 1/4 to about 2 inches, more preferably about 3/4 to about 1-1/2 inches, even more preferably about 3/4 to 1-1/4. For example, in an embodiment wherein the membrane device contains a bundle 9" in diameter and 72" in length, as the bundle is fabricated from a belt of gas-separation membrane fiber, 1/4" tubular polyethylene tubing is placed in the bundle at various intervals: at 2" diameter (3-1/4"×72" tubes placed 2" apart), at 4" diameter (6-1/4"×72" tubes placed 2" apart), at 6" diameter (9-1/4"×72" tubes placed 2" apart), and at 8" diameter (12-1/4"×72" tubes placed 2" apart), as depicted in FIG. 3.
The length of the flow channels should be sufficient to promote counter-current flow along a major portion of the length of the hollow fiber membranes. The flow channels preferably extend along the length of the bundle between the tubesheets between about 0 to 100%, more preferably between about 50 to 100%, even more preferably between about 80 to 100%. Other examples of materials useful as flow channels include materials that have mechanical strength and high void fraction such as open cellofoam, helically wound polyethylene fiber, large-bore porous hollow fibers, elastic sleeving, metallic screen rolled in tubular or triangular form, and the like.
The entire membrane device is placed within an elongated shell so as to form a seal between the tubesheets and the shell, thus preventing the fluid from communicating across or through the seal. The seal is formed by any capping means which provides a fluid tight seal between each of the tubesheets and the shell, including an adhesive material, an endcap, a gasket, and the like. The shell may comprise any material capable of protecting the membrane device from the environment, and is preferably a pressure vessel. Preferably, the casing material is a plastic such as PVC, a composite, or a metal. More preferably, the casing material is metal, such as aluminum or steel. The shell may optionally contain a material to absorb shock and/or to insulate the membrane device, wherein such material includes polyurethane foam and tightly packed foam beads.
Capping means are located at each end of the shell, and are arranged for sealing the end of the shell near the tubesheet to form regions adjacent to the opposite faces of the tubesheets which are opened to the hollow fiber membranes, i.e. (1) the feed inlet region adjacent to the outside face of the first tubesheet; and (2) the non-permeate outlet region adjacent to the outside face of the second tubesheet. Such end capping means are attached, i.e. optionally sealed or removably attached, to the shell by appropriate attachment means such as bolting, using o-rings and grooves, clam-shell retainer and other equivalent means.
The membrane device comprises a feed inlet means for introducing into the feed inlet region the fluid mixture to be separated, such as a port, nozzle, fitting, or other suitable opening. The feed inlet means may be located in the first end capping means. The feed inlet region is defined by the first tubesheet, the first end capping means, and the shell. The feed inlet region communicates with one end of the hollow fiber membranes, thus allowing the feed fluid mixture to be separated to flow into and down the bores of the hollow fiber membranes. Preferably, the feed inlet region is sealed to prevent fluid communication with the outside of the membrane device or with the region between the tubesheets which is outside the hollow fiber membranes.
The membrane device comprises a non-permeate outlet means for removing the retentate from the non-permeate outlet region. The retentate fluid exits the bores of the hollow fiber membranes at the end opposite the feed inlet end, and preferably, the exiting fluid enters a non-permeate outlet region. The non-permeate outlet means may be located in the second end capping means, and includes a port, nozzle, fitting, or other suitable opening. The non-permeate outlet region is a cavity defined by the second tubesheet, the shell, and the second end capping means. Preferably the non-permeate outlet region is sealed such that fluid cannot communicate with the outside of the membrane device or with the region between the tubesheets which is outside the hollow fiber membranes.
The membrane device comprises a permeate outlet means for removing the fluid which permeates through the hollow fiber membranes into the permeate outlet region. The permeate outlet means include a port, nozzle, fitting, or other suitable opening. In a preferred embodiment, the permeate outlet means is located at an end near the feed inlet means, resulting in counter-current flow of the feed fluid mixture as compared to the flow of the permeate fluid. This counter-current flow enhances the concentration gradient along the hollow fiber membranes, thereby improving the recovery and productivity of the membrane device. In an alternative embodiment, the permeate outlet means is located at the end opposite to the feed inlet means providing counter-current flow.
In a preferred embodiment, the membrane devices of this invention are useful in separating a mixture wherein the feed mixture comprises a gas mixture of one or more gases. The feed mixture preferably comprises at least one of the gases selected from the group consisting of hydrogen, helium, oxygen, nitrogen, carbon monoxide, carbon dioxide, methane, hydrogen sulfide, ammonia, methane, other light hydrocarbons, and the like. Light hydrocarbons as used herein refers to C 1-4 containing saturated and unsaturated hydrocarbons. Examples of such gases being separated are hydrogen and/or helium from light hydrocarbons, oxygen from nitrogen, nitrogen from methane, carbon monoxide and/or carbon dioxide from light hydrocarbons, and the like.
In the embodiment wherein the fluid mixture comprises a mixture of gases, generally, one side of the membrane is contacted with a feed gas mixture under pressure, while a pressure differential is maintained across the membrane. At least one of the components in the gas mixture selectively permeates through the membrane more rapidly than the other components. A stream is obtained on the low pressure side of the membrane which is enriched in the faster permeating component. The permeated gas is removed from the low pressure/downstream side of the membrane. A stream depleted in the faster permeating gas is withdrawn from the high pressure/upstream side of the membrane. Preferably, the separation process is carried out at pressures and temperatures which do not adversely affect the membrane. For example, for an oxygen/nitrogen mixture, the pressure differential across the membrane is preferably between 10 and 500 psig, more preferably between about 50 and 200 psig; whereas for a carbon dioxide/methane, the pressure differential across the membrane is preferably between 50 and 1000 psig, more preferably between about 50 and 500 psig. Additionally, for a continuous operation system, the operating temperature is preferably from about 0-100° C., more preferably from about 0-50° C.
In another preferred embodiment, wherein the fluid mixture to be separated comprises liquids, the material is transported through or across the membrane as a gas or vapor. The permeate may be removed from the device either as a gas or vapor or it may be condensed and removed as a liquid. This process of separation is referred to as membrane stripping, membrane distillation, or pervaporation and is preferably used to separate volatile compounds from non-volatile compounds. In membrane stripping, a microporous membrane is used and the permeate is removed from the device as a gas or vapor; in membrane distillation, the permeate is condensed and removed from the device as a liquid; whereas in pervaporation, a non-microporous membrane is used and the permeate may be removed as a gas or vapor as a liquid after condensation. Examples of volatile compounds which may be removed from liquid mixtures include C 1-10 aliphatic and aromatic halogenated hydrocarbons such as dichloromethane, dibromomethane, chloroform, tribromomethane, carbon tetrachloride, 1,1-dichloroethane, 1,2-dichloroethane, 1,1,1-trichloroethane, 1,1,2-trichloroethane, trichloroethylene, tetrachloroethylene (perchloroethylene), 1,2-dichloropropane, chlorobenzene, dichlorobenzene, trichlorobenzene, and hexachlorobenzene; C 1-10 aliphatic and aromatic hydrocarbons such as methane, ethane, propane, butane, hexane, heptane, octane, ethylene, propylene, butylene, benzene, toluene, and xylene; C 1-10 aliphatic and aromatic alcohols such as methanol, ethanol, propanol, butanol, pentanol, hexanol, and phenol; C 1-8 ketones such as acetone, methylethyl ketone, methylisobutylketone, pentanone, and hexanone; C 1-8 ethers such as bis(2-chloroethyl)ether; C 1-8 amines such as methylamine, dimethylamine, trimethylamine, ethylamine, diethylamine, triethylamine, ethylenediamine, and aniline; and the like. Less volatile liquids from which the volatile compounds may be removed include water and mixtures of water and organics. In another preferred embodiment, gases may be purified from solutions or other liquid impurities. Examples of such gases include oxygen, carbon monoxide, carbon dioxide, sulfur dioxide, hydrogen sulfide, ammonia, and the like.
The hollow fiber membrane device of the invention is constructed using processes well known in the art. Generally, the hollow fiber membranes are bundled into a desirable shape, preferably the bundles are arranged in a series of concentric layers or bias wrap laying down of fibers. The tubesheets are formed about the ends of the bundle either simultaneously with laying down of the fibers, or after the bundles are formed by techniques well known in the art. The permeate flow channels are arranged within the hollow fiber bundle during fabrication of the bundle, wherein the permeate flow channels are preferably arranged at the interface between the adjacent membrane layers.
The hollow fiber bundle with tubesheets, with or without the core, is inserted into the shell, followed by attachment of endcaps at the first and second ends of the shell. The following descriptions of preferred embodiments as illustrated by the figures is provided to further illustrate the invention.
FIG. 1 illustrates a hollow fiber membrane device 1 of the invention wherein the entire device is housed within a shell 2. The device comprises a bundle of hollow fibers 3, comprising permeate flow channels 4 interspersed in the bundle. The permeate flow channels 4 comprise a series of hollow cylinders and are arranged in a parallel fashion to the core tube 5. The core tube 5 extends through the first tubesheet 6 and the second tubesheet 7 and is bonded thereto. In one embodiment, the hollow fiber bundle 3 is arranged around the core tube 5. Encircling the entire hollow fiber bundle 3 and tubesheets 6 and 7 is a case 2. A first endplate 8 is adapted for sealing the first end of the case 2 nearest the first tubesheet 6. A second endplate 9 is adapted for sealing the second end of the case 2 nearest the second tubesheet 7. The first endplate 8 comprises a feed inlet port 10 for introducing into the device a fluid mixture to be separated. The second endplate 9 comprises a non-permeate outlet port 11 to withdraw the retentate fluids from the device. A permeate outlet port 12 for withdrawing the permeate fluid from the device is located in the case 2 near the first tubesheet 6. The first tubesheet 6, first endplate 8, and case 2 form a feed inlet region 13, wherein the feed fluid mixture is introduced and which is adjacent to the face of the first tubesheet 6 to which the one end of the hollow fiber bundle 3 is open. A non-permeate outlet region 14 is defined by the outside face of the second tubesheet 7, the second endplate 9, and the case 2, and is the region where the non-permeating fluids exit the hollow fibers, and from which the non-permeating fluids are withdrawn through the non-permeate outlet port 11. The permeate fluid is removed via the permeate outlet port 12.
FIG. 2 illustrates another embodiment of the invention device, wherein the hollow fiber membrane device 1 is adapted for the use of a sweep fluid. The entire device 1 is housed within a shell 102. The device comprises a bundle of hollow fibers 103, comprising permeate flow channels 104 interspersed in the bundle. The permeate flow channels 104 comprise a series of hollow cylinders and are arranged in a parallel fashion to the core tube 105. The core tube 105 extends through the first tubesheet 106 and the second tubesheet 107 and is bonded thereto. In one embodiment, the hollow fiber bundle 103 is arranged around the core tube 105. Encircling the entire hollow fiber bundle 103 and tubesheets 106 and 107 is a case 102. A first endplate 108 is adapted for sealing the first end of the case 102 nearest the first tubesheet 106. A second endplate 109 is adapted for sealing the second end of the case 102 nearest the second tubesheet 107. The first endplate 108 comprises a feed inlet port 110 for introducing into the device a fluid mixture to be separated. The second endplate 109 comprises a non-permeate outlet port 111 to withdraw the retentate fluids from the device. A permeate outlet port 112 for withdrawing the permeate fluid from the device is located in the case 102 near the first tubesheet 106. The first tubesheet 106, first endplate 108, and case 102 form a feed inlet region 113, wherein the feed fluid mixture is introduced and which is adjacent to the face of the first tubesheet 106 to which the one end of the hollow fiber bundle 103 is open. A non-permeate outlet region 114 is defined by the outside face of the second tubesheet 107, the second endplate 109, and the case 102, and is the region where the non-permeating fluids exit the hollow fibers, and from which the non-permeating fluids are withdrawn through the non-permeate outlet port 111. The permeate fluid is removed via the permeate outlet port 112. The core 105 at a first end has a sweep fluid inlet port 115 adapted for introducing a sweep fluid into the hollow fiber bundle 103 via perforations 116 in the core 105. The core 105 is plugged by a plug 117 at its second end, thereby forcing all the sweep fluid into the hollow fiber membrane bundle 103. The device further comprises a series of permeate flow channels 104 which are arranged within the bundle as described above.
FIG. 3 demonstrates a cross-sectional view of the membrane device shown in FIG. 1. A bundle of hollow fibers 203 arranged about a core or an axial void 205, with a series of permeate flow channels 204 is arranged in concentric fashion through the bundle.
Operation of the membrane device can be illustrated by reference to FIG. 1. A fluid mixture to be separated is introduced via the feed inlet port 10 into the feed inlet region 13 under pressure. The fluid mixture flows through the bores of the hollow fiber membranes, and a portion of the feed fluid mixture permeates across the membranes into the shellside region of the membrane device. The permeate flow channels 4 provide lower pressure resistance to flow and the permeate fluid to flow countercurrent to the feed fluid flow direction. The retentate fluid exits the hollow fibers of the bundle 3 into the permeate outlet region 14 and is removed from the device through the non-permeate outlet port 11. The permeate is removed from the shellside of the device through the permeate fluid outlet port 12.
Thus, a device comprising hollow fiber membranes with discrete flow channels incorporated in the membrane bundles is disclosed. Although preferred embodiments of the invention device have been described in some detail, it is understood that obvious variations can be made without departing from the spirit and scope of the invention as defined by the appended claims.
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A boreside feed gas separation membrane device containing primarily hollow fiber membranes with discrete flow channels incorporated into the bundle to allow for pressure removal of the permeate gas collected on the shellside of the device is described. The flow channels minimize pressure drop and/or the build-up of back pressure on the shellside of the device while maintaining proper counter-current flow patterns in the device. The incorporation of flow channels results in improved efficiency of the device, especially for feed streams or membrane types that lead to high permeate flow rate that result in excessive shellside pressure drops.
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FIELD OF THE INVENTION
This invention concerns the control of a video storage device associated with a video mixer.
BACKGROUND OF THE INVENTION
Video mixers, known also as production switchers, are used for combining and manipulating video signals from a number of video sources to form one or more output video signals comprising selections from, and combinations of, the video inputs. In live production the mixer operator controls the transition from one shot to the next; facilities for the combination and selection of audio signals may also be provided in the same equipment.
Typically an operator is able to select a video signal by pressing one of a row of push buttons, known as a “bus”. Mixers usually have between two and eight such busses grouped in pairs, which are associated with a particular video output. This output consists of one of the bus selections, or a combination of the selections from the two paired busses. The operator typically changes the output from one bus to the other, and thus the output picture from one picture to another picture, by moving a fader handle, often known as a T-Bar. The transition may be, for example, a cross-fade, or a wipe. In a cross-fade, the proportions of the two bus signals depend on the position of the fader. In a wipe both signals are present at full amplitude in the output but a variable portion of one picture is removed to reveal the other picture. The shape of the revealed portion is pre-determined by the operator and the relative areas of the output picture contributed by the respective input pictures depend on the position of the fader.
Other types of combination of, and transition between, pairs of busses are known and these may involve the use of signals from other busses to modify the transition or combination. A common method of combining pictures is the technique of “keying” in which the brightness or colour of a part of a picture is used to control the substitution of that part of that (“foreground”) picture for the equivalent part of another (“background”) picture. Alternatively the controlling, or key, signal may be a third signal different from (but usually related to) the foreground or the background.
Video mixers may not necessarily be controlled directly by an operator. Semi-automatic systems exist in which the operator initiates a video transition from one shot to another (e.g. between one bus and another), but the type of transition and the length of time needed for the transition to occur have been pre-programmed. Similarly, fully automatic systems are known in which all aspects of the video transitions are under the control of an automation system.
It is well-known to include a video store in a video mixer system, for example a solid state memory device holding one or more frames of video. If several frames can be stored, it is then possible for a dynamic video sequence to be played in response to an action by the operator, such a sequence is often referred to a “clip” by analogy with a short length of film.
Typically the sequence may be started when the operator moves the fader handle to initiate a transition from one video source to another. For example, as the edge of a wipe transition passes across the output picture, a moving logo, played from a store, may be keyed over the wipe.
Although it is possible to initiate the playing of the clip of the logo from the start of the fader movement controlling the wipe transition, the progress of the logo is determined by its original recording, whereas the progress of the wipe transition is controlled by the operator. The operator may wish to modify the progress of the wipe transition in real time in response to the video content, which may be live and therefore unpredictable.
SUMMARY OF THE INVENTION
The inventor has appreciated that it may be helpful to associate the timing of playout of a stored video sequence with the progress of a transition from one output picture to another.
The invention consists, in a first aspect, of a method of controlling a video storage device associated with a video mixer in which the timing of playout of a video signal from the video storage device is varied in dependence upon the progress of a transition made by the said video mixer between two video compositions.
Suitably, the said transition is controlled by an operator's movement of a control actuator that simultaneously controls the said transition and the timing of playout of a replayed video signal from the said video storage device.
Advantageously, the read or write address of said video storage device is varied in dependence on the progress of the said transition.
In a further embodiment, one of a plurality of stored frames is selected for whole or partial output from said mixer, the said selection being controlled by the progress of said video transition.
In a second aspect the invention consists of a method of keying a first video signal into a second video signal using a key signal, in which the key signal is replayed from a video store, wherein the timing of playout of the replayed key signal from the said store is varied in dependence upon the progress of a transition in the second video signal made by an associated video mixer between two video compositions.
Advantageously the said transition is controlled by an operator's movement of a control actuator that simultaneously controls the said transition and the time sequence of the replayed key signal from the said video store.
In a yet further aspect one of a plurality of stored frames is selected as the said key signal, the said selection being controlled by the progress said video transition.
In a third aspect the invention consists of a method of controlling a video storage device associated with a video mixer comprising the steps: receiving control signal information indicating progress of a transition made by the said video mixer between two video compositions, and generating a read address for reading video data from the video storage device for supply to the video mixer, the read address being generated at least in part in dependence upon the control signal information.
Advantageously the step of generating a read address for reading video data comprises the steps of: generating a start address of the first frame of a sequence of frames; and incrementing the start address in proportion to the product of the sequence length and the progress of the video mixer transition to generate the read address.
In one embodiment, the step of generating a read address comprises the step of generating a read address in accordance with the equation:
Read Address=Start Address+Rounded value of (Transition Position×Clip Length)
wherein the clip length is expressed in frames; the transition position is zero at the start of the transition and one at the end of the transition
In a fourth aspect the invention consists of a video storage device for a video mixer, comprising a video store, for storing video data therein; control input for receiving control signal information indicating progress of a transition made by the said video mixer between two video compositions, and an address generator for generating a read address for reading video data from the video store for supply to the video mixer, the read address being generated at least in part in dependence upon the control signal information.
Advantageously the address generator comprises: an initial address generator for generating the start address of the first frame of a sequence of frames an address modifier for incrementing the start address from the initial address generator in proportion to the product of the sequence length and the progress of the video mixer transition to generate the read address.
In one embodiment the address modifier generates a read address in accordance with the equation:
Read Address=Start Address+Rounded value of (Transition Position×Clip Length)
wherein the clip length is expressed in frames; the transition position is zero at the start of the transition and one at the end of the transition.
In a fifth aspect the invention consists of a video mixer comprising: a video storage device according to the invention, and an operator-controlled control actuator for controlling a transition made by the video mixer between two video compositions and the timing of playout of a replayed video signal from the video storage device.
BRIEF DESCRIPTION OF THE DRAWINGS
For a better understanding of the present invention, and to show how it may be brought into effect, reference will now be made, by way of example, to the accompanying drawings, in which:
FIG. 1 shows a video mixer system; and
FIG. 2 shows video clip storage system according to an embodiment of the invention.
DETAILED DESCRIPTION OF THE INVENTION
A video mixer system is shown in FIG. 1 .
Input video signals ( 1 ) are input to a cross-point switching matrix ( 2 ), which provides three output video signals: Bus A ( 3 ), Bus B ( 4 ), and Key Bus ( 5 ). It will be apparent to a skilled person that, depending upon the desired video mixer output signal, a video signal might not be output on all output busses at all times.
In addition, in some embodiments the Key Bus ( 5 ) may comprise two signals: namely video data to be inserted into the picture area, and a key signal to define the part(s) of the picture area into which the data is to be inserted.
The signals to be output on the respective busses are chosen from the inputs ( 1 ) by the matrix ( 2 ) under the control of a control panel ( 6 ), for example by means of the illustrated bus selection control signal The control panel ( 6 ) may have, for example a row of buttons corresponding to each Bus.
The signals ( 3 ) and ( 4 ) are fed to a mix/effects unit (or M/E unit) ( 7 ), which forms an output video ( 8 ) by selecting or combining the signals ( 3 ) and ( 4 ). The choice between or combination of the signals ( 3 ) and ( 4 ) is controlled from the control panel ( 6 ) via the illustrated transition control signal, possibly by means of a operator actuated control such as a fader handle or T-Bar on the panel.
In some embodiments the M/E unit ( 7 ) may be able to carry out keying operations or other methods of combining pictures in dependence upon picture content, However, this embodiment has not been illustrated for clarity.
The combined video signal ( 8 ) is fed to a down-stream-keyer (or DSK) unit ( 9 ) which also receives the Key Bus video signal ( 5 ). Additional controls on the panel ( 8 ), for example the illustrated Key control signal, enable the operator to combine the Key Bus video signal ( 4 ) with the combined video signal ( 8 ) to give a final video output signal ( 10 ).
The skilled person will appreciate that the M/E unit ( 7 ) and the DSK unit ( 9 ) may operate simultaneously and that the picture composition at the output ( 10 ) may not be identical with any of the inputs ( 1 ) and need not necessarily contain information from any of these inputs. Therefore a transition between one output composition to another may not involve the simple replacement of one input video by another—a transition may involve changing the way input pictures and/or video generated or stored in the mixer system are combined or presented to a viewer.
The system also includes a clip-store ( 11 ) that can write one of the inputs ( 1 ) to the matrix ( 2 ) into its storage registers; and, read out its storage registers back to the matrix ( 1 ) In this way a short input video sequence could be stored and then subsequently played back to, for example, the key bus ( 5 ). It is also possible to store both a key and a foreground signal for simultaneous replay. It is also known for a clip store to have more than one output. For example, a separate key-signal output may be provided so that every output frame has a key-signal frame associated with it and the key-signal frame can be used to control the insertion of the clip-store output frame into a background signal.
A typical video transition required from such a system might be a wipe from one video source to another where a logo moves across the screen at the same time as the wipe transition crosses the screen. This would be achieved by setting the M/E block ( 7 ) to carry out the wipe; the moving logo would have been previously stored as a clip in the store ( 11 ). The operator would move the fader controlling the wipe and, at the same time, the logo clip would be played from the store ( 11 ) and keyed over the wipe by the DSK block ( 9 ).
The video storage system shown in FIG. 2 (which could be used as the clip-store ( 11 ) in FIG. 1 ) will now be described.
The invention will be described with reference to a sequence of video frames comprising a video clip. However, the invention is not intended to be limited to sequences of video frames, and may be applied to the timing or spatial position of the read out and display of a single video frame, and reference to video clips or clip storage below should be interpreted accordingly.
Video signal ( 20 ) is input to a store ( 21 ) that has a number of addressable locations into which video can be written, and from which video can be read. The video signal read from the store appears at the output ( 22 ).
The writing of video into the store is controlled by a write address ( 23 ) from a write address generator ( 24 ), which responds appropriately to control signals ( 25 ), for example a clip record control signal, from a control panel. It is convenient for the store to be organised by video frames so that an incoming frame can be directed to a particular store location and a complete frame can be output from a particular location. Ordered groups of locations can be assigned to clips comprising sequences of frames. The illustrated video input timing information, which may be separated from the video input ( 20 ), is used by the address generator ( 24 ) to ensure the correct relationship between the write address ( 23 ) and the timing of the store input ( 20 ).
Video can be written to the store either continuously or intermittently. In intermittent writing the write address generator ( 24 ) provides a finite sequence of frame addresses associated with particular video input frames. In continuous writing a finite sequence of frame addresses is repeated so that newly arriving input frames overwrite the oldest frames.
The store may be partitioned into a number of areas for different clips or stills, each having its own address or range of addresses.
Reading from the store is controlled by the read address ( 26 ) If a fixed address is supplied to the store ( 21 ) the frame at that location is output repetitively (i.e. a still picture is output). A clip can be replayed by supplying the relevant sequence of addresses. It is, of course, possible to play a clip repetitively by repeating the sequence of addresses.
The playing of a clip can be synchronised with a video transition as follows. A read address generator ( 27 ) receives a clip play control input ( 28 ) from the control panel (e.g. the block ( 6 ) of FIG. 1 ) to identify the clip to be played and it outputs the address of the first frame of the clip. This address is passed to an address modification block ( 29 ) that also receives fader position information ( 30 ) about the position of the fader on the mixer's control panel that will control the progress of a video transition.
As the fader is moved by the operator, the clip read address is incremented in proportion to the product of the clip length and the fader position, and the resulting sequence of addresses forms the read addresses ( 26 ) to the store ( 21 ) This can be expressed as follows:
Read Address=Start Address+Rounded value of (Fader Position×Clip Length)
Where: the clip length is expressed in frames, and the fader position is zero at the start of its travel and one at the end of its travel. The rounding ignores any fractional results from the multiplication so that the resulting address is always an integer.
Once the read address is sent to the store, the addressed frame is read out under the control of the illustrated video output timing signal. Once that frame has been played, the current value of the fader position data ( 30 ) is used to determine the next frame to be played.
The duration of the video transition in frames may be different from the number of frames comprising the clip. If the operator moves the fader slowly, some clip frames will be played more than once. If the operator moves the fader quickly, some frames may be omitted. If the operator, having started the transition by moving the fader forwards then moves the fader backwards, the clip will be played backwards. And, if the operator stops moving the fader part way through the transition the clip will “freeze” to a still frame.
Advantageously the operator provides information to the control system to determine what happens at the start and end of the transition. It will usually be convenient for the clip store ( 11 ) to output a black frame until the start of the transition. At the end of the transition (when the fader reaches the end of its travel) it may be appropriate to continue to output the final frame of the clip. Alternatively it may be preferable for the clip store output ( 22 ) to return to black, possibly fading to black over a user-defined time period.
It may be that only part of a clip is to be synchronised with -a transition; in this case the clip start address and clip length values used in calculating the read address ( 25 ) will need to be modified to select the correct part. Alternatively, more than one clip may need to be played in sequence, or a clip repeated, either forwards or backwards, in the course of the video transition. These effects can be achieved by creating a sequence of address modifications that can be performed by the block ( 29 ).
In a further embodiment the read address ( 26 ) may refer to individual pixels or lines of stored video, and the modifier ( 29 ) may modify the timing of the read-out of lines or pixels from the display so that the position of the stored information within the output picture ( 10 ) is varied in synchronism with the progress of a video transition under the control of the fader position data ( 30 ).
The read address generator ( 27 ) may operate in other, known, ways such as providing a read address which is derived from the write address (as shown by the connection ( 31 )) so that the clip store operates as a variable video delay and the delay is modified by the block ( 29 ) in dependence on the progress of a video transition. It is also possible for the write address to be modified in dependence on the fader position whilst the read addresses remain unmodified.
The invention has been described by way of example and other variants within the inventive concept will be apparent to the skilled person. For example: the fractional part of the product of fader position and clip length could be used to control interpolation between stored frames; the sequence of the clip frames could be reversed; or, a non-linear relationship between the fader position and the store address could be used.
While the present invention has been described herein with reference to the illustrative embodiment, the skilled person will understand that various modifications may be made without departing from the inventive concepts defined in the appended claims.
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A video mixer may be employed to form a transition between two video compositions, for example a fade or a wipe. A video storage device may be associated with the video mixer and plays out a video signal, the timing of which is controlled in dependence upon the progress of the transition made by the said video mixer.
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BACKGROUND OF THE INVENTION.
This invention relates to improvements of melt-blowing processes and apparatuses applying to multiple rows of spinning orifices describes in U.S. Pat. No. 4,380,570 and 5,476,616, which are herewith incorporated as reference. More particularly, it relates to the improvement whereby melt-blowing spinnerettes are mounted on the surfaces of a polygonal melt-blowing extrusion die block thereby spinning thermoplastic fibers away from the center of the polygon at high extrusion rates, said fibers are then being deflected about 90 degrees by an air stream from a circular or polygonal air ring to enhance fiber entanglement and web formation of high bulk and low density.
OBJECTS OF THE INVENTION
It is an object of the present invention to increase the productivity of a melt-blowing extrusion die and enhance the fiber entanglement by an air stream directed at an angle at the melt-blown fibers to form a fiber web of high bulk and low density.
Another object of the invention is to obtain a fiber web of high compression recovery by adding a binder such as adhesive latex or thermoset phenol-formaldehyde or resorcinol-formaldehyde to said deflecting air stream to form an adhesive spray, thus binding the fiber cross-over points and producing a rigid web structure in a subsequent curing step.
SUMMARY OF THE INVENTION
These and other objects of the invention are achieved by mounting melt-blowing spinnerettes vertically on the surfaces of a polygonal cylinder, thereby melt-blowing fibers radially away from the center of the polygon horizontally in a radial fashion, the deflecting the radial fiber stream downward by means of a circular air or air/adhesive spray stream from one or more circular or polygonal air spray tubes, thus forming a highly entangled and/or bonded fiber web of high bulk and low density.
BRIEF DESCRIPTION OF THE DRAWINGS
A better understanding of the present invention as well as other objects and advantages thereof will become apparent upon consideration of the detailed disclosure thereof, especially when taken with the accompanying drawing, wherein like numerals designate like parts throughout;
FIG. 1 is a schematic top view of a polygonal die block having twelve spinnerettes mounted circumferentially, and showing the radial fiber spinning towards the circular air deflector tube;
FIG. 2 is across sectional side view of the same die block, showing the downward deflection of the fiber stream;
FIG. 3 is a cross sectional top view of a melt-blowing spinnerette, showing the flow of polymer, air, and fibers.
FIG. 4 is a top view of a cylindrical die block, where the spinnerettes have curved sealing surfaces matching the radius of the cylinder.
DETAILED DESCRIPTION OF THE INVENTION
It has been found in previous melt-blowing assemblies such as described in U.S. Pat. Nos. 4,380,570 and 5,476,616, that capacities for making fine fibers were limited by the number of spinning orifices over the width of an extrusion die from 20 spinning orifices per inch width of extrusion die head (U.S. Pat. No. 4,048,364, col. 5, line 55) to 177 orifices per inch width (U.S. Pat. No. 5,476,616, col. 4, line 23, Table 1, Example 9). In the present invention this orifice density can be increased to about 888 spinning orifices per linear inch width of extrusion die by using the following arrangement in Example 1 of this specification: A dodecagonal fixed die head 1 shown in FIG. 1 and 2 is mounted over a moving collecting screen 25. The die head has a diameter from edge 26 to edge 27 of 13,525 inches, and has 12 vertical surfaces 28 of 3.5×10 inches, each having eight rows of spinning orifices in a spacing as described in U.S. Pat. No. 5,476,616, col. 4, line 23, Table 1, Example 9. The total number of spinning orifices of this die block is approximately 21,333. The air ring 29 of dimeter of 24 inches is blowing fibers 30 onto the collecting screen 25 which moves the fiber web 31 toward a winding device at a constant speed. The web 31 of 24 inches width is produced by the 21,888 spinning orifices, or 888 spinning orifices per inch width of collected web 31. The 90 degree fiber deflection by the air stream from air ring 29 yielded a much bulkier web than when blown straight onto a collection device as described in Example 1. Polymer is moved under pressure from an extruder or other supply device into the main polymer cavity 21 of the die block 1 to the twelve distribution channels 23, which feed the spinnerette supply cavity 2. The polymer then enters the twelve spinnerette 24, one of which is depicted in FIG. 3 in detail.
Hot pressurized gas is fed from a hot gas supply system to the gas manifold 32 though pipes 33 and 34, the manifold 32 is connected to the gas channels 35, which feed gas through channels 36 and 22 to the spinnerette gas inlet 7.
Referring now to FIG.3, The spinnerette assembly is mounted on the die body 1 which supplies polymer melt to a supply cavity 2 feeding the spinning nozzles 3 which are mounted in the spinnerette body plate wherein nozzles 3 are spaced from each other at a distance of at least 1.3 times the outside diameter of a nozzle 3. The nozzles 3 lead through the gas cavity 5, which is fed with hot gas, air, or other suitable fluids from the gas inlet slot 6. The primary supply gas enters the spinnerette assembly through inlet channel 7 into a supply cavity 8 which is in the form of a first gas cavity having a height of at least six times the outside diameter of a nozzle 3. The baffle plate 9 diverts the gas stream and forces the gas through the slot 6 toward the base 10 of the nozzle 3. The nozzles 3 protrude through gas cover plate 11 through tight fitting holes 12 arranged in the same pattern as the nozzle mounts in spinnerette body plate 4. The gas cover plate family further consists of spacer plate 13 which forms a second gas cavity 14 between plates 11 and 15, said second gas cavity having a height of at least one half of the diameter of a nozzle 3, and wherein first gas plate 11, spacer plate 13, and second gas plate 15 have a total combined thickness of less than ten times the outside diameter of a nozzle 3. Another gas cover plate 16 is sometimes added to the assembly to facilitate expansion of the gas to attenuate the fibers exiting the nozzles 3. The complete path of the gas is now from inlet channel 7 into the gas supply cavity 8 through inlet slot 6 into the gas cavity 5 which has a specific height of 17. The gas then flows through gas holes 18 of plate 11 into the gas cavity 14 and then around the nozzles 3 through holes 19 and 20, in which the nozzles 3 are centered. The gas inlet slot 6 can be replaced by a series of holes having a similar total cross sectional opening as the slot they replace.
The invention is further illustrated by the following specific examples, which should not be taken as limitations on the scope of the invention
EXAMPLE 1
A dodecagonal melt-blowing die 1 having twelve spinnerette mounting surfaces 28 of 10×3.5 inches, and an edge 26 to edge 27 diameter of 13.523 inches as depicted in FIG. 1 and 2 was used. Twelve spinnerettes 24, each having eight rows of spinning nozzles 3 as illustrated in FIG. 3 were bolted to the mounting surfaces 28. The nozzle spacing was 0.045 inches, each spinnerette had 1776 spinning orifices. The total number of spinning orifices of this melt-blowing die was 21,312. Polypropylene of MFR 70 was supplied from an extruder to the die 1 at a rate of 3000 LB/hour under the following conditions:
______________________________________Extruder temperature (Degree F) 450Die 1 temperature (Degree F) 680Air temperature (Degree F) 750Air pressure (PSI) 30______________________________________
An air ring 29 of 24 inches diameter was deflecting the circular, horizontal fiber 30 stream downward onto a moving collecting screen 25 which traveled at 33.9 feet per minute. The collected web 31 had a basis weight of 3607 gram per square meter, a thickness of 15 cm, and a web density of 0.024 gram/cubic cm or 1.5 LB/cubic foot. The fiber diameters ranged from 5 to 8 micrometers. The screen distance 37 from the die block 1 was 30 inches.
EXAMPLE 2
Example 1 was repeated except the polymer used was polyethylene terephthalate (PET) of 0.55 intrinsic viscosity, and the extruder temperature was 560 degree F. The collecting screen moved at 33.9 feet per minute; the web basis weight was 36 gram per square meter, at a web thickness of 20 cm. The web density as 0.018 gram per cubic cm or 1.1 LB per cubic foot. The fiber 30 diameters ranged from 4 to 8 micrometers.
EXAMPLE 3
Example 2 was repeated except that the deflecting air stream from air ring 29 contained an adhesive acrylic binder spray (Rohm & Haas, Rhoplex TR-407), depositing 12% by weight of dry latex onto the fiber 30; web drying was accomplished in a hot air stream of 230 degree F. for 3 minutes. The final web thickness was 20 cm, basis weight 4043 gram per square meter, and web density 0.020 gram per cubic cm or 1.2 LB per cubic foot.
EXAMPLE 4
Example 2 was repeated except that the deflecting air stream from air ring 29 was turned off on one side, fiber web was collected by a vertical collecting screen at a distance from the spinnerette 24 of 35 inches. The web had the following properties:
______________________________________Basis weight (gram per square meter) 3610Web thickness (cm) 6Web density (gram per cubic cm) 0.060Web density (LB per cubic foot) 3.7Fiber diameter (micrometer) 4 to 8______________________________________
EXAMPLE 5
In this Example the products of Examples 2 and 3 were compared in their respective compression recovery: On each sample of 24×24 inches a steel plate of same dimension and 0.125 inches thickness, weighing 20 pounds, was placed for ten minutes, after which the steel plate was lifted and removed. The thickness recovery of each sample, measured two minutes after removing the steel plate, is listed in Table 1:
TABLE 1______________________________________ Example 2 Example 3 (non-bonded) (bonded)______________________________________Basis weight (gram/sq. meter) 3610 4043Initial thickness (cm) 20 20Initial density (gram/cubic cm) 0.018 0.020Final thickness (cm) 8 18Final density (gram/cubic cm) 0.045 0.022______________________________________
DISCUSSION OF EXAMPLES
The present invention demonstrates a high capacity system for making high-loft, low-density fiber webs from thermoplastic polymers for insulation or cushioning applications. A comparison of Examples 1 and 2 shows PET producing a lower density web than polypropylene, which is more desirable for most applications. Comparing Examples 2 and 3 shows the improved compression recovery of the bonded web as listed in Table 1. Examples 2 versus 4 demonstrates the significance of the 90 degree deflection of the fibers by the secondary air stream, which causes higher entanglement and lower density. The combination of fiber deflection and adhesive bonding, using PET polymer represents the preferred embodiment of this invention. Looking at FIG. 4, the binder is supplied from storage tank 43 through metering pump 44 into the gas supply line 46 through the atomizer device 45 which sprays the binder as a fine mist into the gas stream from gas compressor 41 which is regulated by valve 42.
The polygonal die block 1 can have a multiplicity of spinnerettes 24 or can be cylindrical as shown in FIG. 4 where the multiplicity of spinnerettes 38 have curved surfaces to seal on the curved surface 39 of the fixed cylindrical die block 40.
The minimum edge-to-edge diameter (D) of a polygonal die block is:
D (in inches)=spinnerette width (in inches)/sin (180°/No. of spinnerettes on polygon)
While the invention has been described in connection width several exemplary embodiments thereof, it will be understood that many modifications will be apparent to those of ordinary skill in the art; and that this application is intended to cover any adaptations or variations thereof. Therefore, it is manifestly intended that this invention be only limited by the claims and the equivalents thereof.
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There is disclosed a novel apparatus and process for melt-blowing fiberforming thermoplastic polymers at high rates to form high-loft, low density fine fiber webs suitable for insulation applications. The high rates are achieved by mounting melt-blowing spinnerettes on the surfaces of a polygonal cylinder and spinning fibers in a radial fashion, then deflecting the fiber streams 90 degrees by a secondary stream of cold air.
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BACKGROUND OF THE INVENTION FIELD OF THE INVENTION
The invention relates to a device for hooking a heddle on a harness cord of a weaving loom of the Jacquard type or a harness cord on a string of a Jacquard loom, and to a Jacquard loom equipped with such a device. The invention also relates to a method for the manufacture of such a device and to a method for hooking a heddle on a Jacquard harness cord by means of such a device.
BRIEF DESCRIPTION OF THE PRIOR ART
A Jacquard mechanism hook is conventionally associated with a string to which one or more cords are connected, the set of cords forming the harness of the Jacquard mechanism. In its lower part, each cord has to be hooked to the upper end of a heddle which comprises an eye for the passage of a warp thread. To carry out this hooking, it is known from EP-A-0 915 195 to injection-mould on the upper end of a heddle an endpiece which forms an orifice for the passage and wedging of the lower part of a cord, a flexible sheath of synthetic material being then slipped around the endpiece in order to assist in immobilizing the lower part of the cord. To exert a significant clamping force, such a sheath must have a relatively large thickness, thus giving rise to friction between the various sheaths mounted on adjacent heddles during the crossing of two heddles driven in opposite movements when the layout density of the heddles is high. These sheaths must also be relatively long in order to exert a sufficient clamping force. In practice, the length of these sheaths is at least greater than their strokes in order to prevent their ends from catching with one another. As a result of this, these sheaths, having considerable length and diameter, form a compact assembly in the upper part of the heddles, this assembly limiting access to the warp threads through the harness during maintenance operations. It also happens that these sheaths yield, thus giving rise to a risk of slipping of the cords in relation to the endpieces.
There are, moreover, heat-shrinkable sheaths which are placed onto the upper ends of the heddles after a cord has been knotted. Once heat-shrunk, these sheaths have a highly irregular external shape which is the image for the shape which they surround, this external shape having protuberances causing premature wear during repeated contacts at the crossing between the sheaths mounted on adjacent heddles.
It is also known from the FR-A-2 822 479 to use a tubular portion made of plastic or of metal in order to clamp the lower end of a cord in a longitudinal slot formed in an endpiece injection-moulded on the upper end of a heddle. The V-shape of the slot does not allow an efficient clamping of the cord which risks slipping when the loom is in operation, which makes the control of the heddle inaccurate and may cause faults in the shed. Furthermore, the slot, which extends over the entire length of the endpiece, embrittles this endpiece in the region of the injection-moulding zone of the heddle. An additional endpiece has to be mounted in the lower part of the tubular section, thus complicating the mounting operation. Finally, before the wedging of the cord, the tubular section is separated from the endpiece completely, so that it can slide level with the eye and with the bottom of the heddle.
The invention is intended more particularly to remedy these disadvantages by providing a novel hooking device, the overall diametral size of which may be greatly reduced, thus allowing a high layout density of the heddles, thereby making efficient hooking possible, and which is easy to mount.
SUMMARY OF THE INVENTION
The invention relates to a device for hooking a first element, of an assembly for the formation of the shed in a weaving loom of the Jacquard type, on a second element belonging to this assembly, the hooking device comprising an endpiece injection-moulded on the upper end of the first element and comprising two first branches, between which is defined an aperture for the passage of the lower end of the second element, this end comprising two strands which extend upwards from a portion of this second element received in this aperture. This device is characterized in that the endpiece comprises two second branches, between which is defined a housing for receiving the abovementioned strands, and in that it also comprises a metallic sleeve mounted on the endpiece and movable in translational motion on this endpiece between a first position, in which the sleeve allows access to the abovementioned aperture and does not interact with the second branches, and a second position, in which the sleeve exerts on the first branches and on the second branches a centripetal force for constricting the aperture and the housing and for wedging the abovementioned portion of the lower end of the second element and the adjacent strands respectively in the aperture and in the housing which are defined by the endpiece.
The use of a metallic sleeve makes it possible for the latter to remain cylindrical with a predetermined cross section, in practice circular, after it has been placed onto the endpiece equipped with a cord. Thus, the overall diametral size of the hooking device can be effectively controlled, thus limiting the risks of wear due to friction. In view of its rigid nature, the tube can exert a sufficient clamping force, whilst it can be substantially shorter and less thick than a conventional sheath. The result of this is that accessibility to the lower part of the harness and to the upper part of the set of heddles is greatly improved, as is accessibility to the warp threads for manual repairs to the harness. In view of the small length of the sleeve, the device can be light-weight. On account of the reduced diameter of the sleeve, the frictional forces are greatly reduced or even eliminated. Owing to the rigidity of the sleeve, the slip resistance of the cord is stable over time. The fact that the strands adjacent to the portion of the second element which is engaged in the aperture are received in the housing defined between the second branches makes it possible to obtain a blocking force distributed over the length of these strands, this being especially effective.
According to advantageous, but not mandatory, aspects of the invention, such a device may incorporate one or more of the following characteristics:
The second branches are provided with free ends which are distant from one another when the sleeve is in its first position and which together form the upper end of the endpiece when the sleeve is in its second position. A first end of the sleeve which is located towards the front of the latter when it passes from its first position to its second position is widened forwards. In this case, the second end of the sleeve may be convergent, extending away from its first end. The sleeve and the endpiece are provided with complementary means which form an abutment stopping the translational movement of the sleeve from its first position towards its second position. By virtue of the stop means, a positioning of the tube is obtained, thus facilitating the mounting operation and the visual check of the good positioning of the heddles in terms of height. The aesthetic appearance of the harness is also improved. There may be provision for the sleeve and the endpiece likewise to be provided with complementary means forming an abutment stopping the translational movement of the sleeve from its second position towards its first position. The means forming an abutment advantageously comprise a relief which is formed on an outer peripheral surface of the endpiece and against which one end of the sleeve comes to bear when the sleeve arrives in one of its positions from the other position. The relief may comprise at least one tooth, against which one end of the sleeve comes to bear when the sleeve arrives in its first position from its second position, this tooth being compatible with a displacement of the sleeve towards its first position from a position opposite the second position. The sleeve and the endpiece are provided with complementary means for immobilizing the sleeve on the endpiece in the second position by the cooperation of shapes. These immobilization means may likewise consist of abutment means stopping the translational movement of the sleeve from its first position towards its second position. These immobilization means advantageously comprise at least one reentrant relief formed in a running part of the sleeve and at least one complementary relief formed on a part of the endpiece which is elastically deformable when the sleeve passes from its first position to its second position. There may be provision for the complementary relief to be formed on one of the two first branches. The sleeve is made from stainless steel or from a copper-based alloy, with a wall thickness smaller than 0.6 mm, preferably smaller than 0.3 mm, more preferably of the order of 0.1 mm. The endpiece possesses, level with or in the vicinity of each of its ends, a substantially conical or frustoconical zone which is convergent, extending away from the opposite end. This makes it possible to limit the risks of catching between adjacent devices mounted on a loom. The second branches are provided with means for centring one of the strands according to a longitudinal axis of the endpiece. The invention also relates to a weaving loom of the
Jacquard type which comprises at least one hooking device, as described above. Such a loom is more economical, and the changes of its harness are easier and quicker than those of the prior art.
The invention also relates to a method for the manufacture of a device, as described above, which comprises steps involving:
a) installing the sleeve on the first element at a distance from its upper end, b) injection-moulding the endpiece on the first element, and c) if appropriate, displacing the sleeve towards its-first position on the endpiece.
Step c) is optional, in as much as it can be carried out later, particularly when the device is used for hooking a heddle on a harness cord.
Finally, the invention relates to a method for hooking a heddle of a weaving loom on a Jacquard harness cord by means of a device, as described above, this method comprising steps involving:
d) introducing the cord into the aperture of the endpiece, e) arranging the strands in the housing formed between the second branches, and f) displacing the sleeve from its first position towards its second position.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention will be better understood and other advantages of the latter will become apparent more clearly in the light of the following description of three embodiments of the hooking device and of a Jacquard loom which are in accordance with its principle, this description being given solely by way of example and being made with reference to the accompanying drawings in which:
FIG. 1 is a partial diagrammatic illustration of a weaving loom according to the invention;
FIG. 2 is a perspective view, on a larger scale, of a device for hooking the upper end of a heddle on the lower end of a cord, the device being in a first configuration;
FIG. 3 is a longitudinal section along the line III-III in FIG. 2 ;
FIG. 3A is a side view, on a larger scale, of the detail 3 A in FIG. 3 ;
FIG. 4 is a view, similar to FIG. 2 , when the hooking device is in a second configuration;
FIG. 5 is a longitudinal section along the line V-V in FIG. 4 ;
FIG. 5A is a cross section, on a larger scale, along the line A-A in FIG. 5 ;
FIG. 5B is a cross section, similar to FIG. 5A , for a hooking device according to a second embodiment of the invention;
FIG. 6 is a longitudinal section, on a larger scale, of a sleeve used in the device of FIGS. 1 to 5 ;
FIG. 7 is a section along the line VII-VII in FIG. 6 ; and
FIG. 8 is a view, corresponding to the detail VIII in FIG. 5 , of a hooking device according to a third embodiment.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
The loom M illustrated in FIG. 1 is equipped with a Jacquard mechanism 2 which controls a plurality of strings 4 , only one of which is illustrated and the lower end of which is associated with a plurality of cords 6 , the assembly of cords forming the harness H of the loom. The lower end 6 a of each cord 6 is connected to the upper end 8 a of a heddle 8 , each heddle being provided with an eye 8 b for the passage of a warp thread 10 and being subjected to the action of a return spring 12 fixed to the frame 14 of the loom by means of a rod 16 .
The heddles 8 may also be controlled individually by the mechanism 2 , in which case each cord 6 is displaced individually by means of this mechanism.
Within the meaning of the present description, the adjective “upper” relates to a part or an element of a device which is directed upwards in a normal configuration of use of the loom M, that is to say upwards in FIG. 1 , whilst the adjective “lower” designates a part or an element directed downwards in this configuration.
A hooking device 20 is used for connecting the upper end 8 a of each heddle 8 to the lower end 6 a of the corresponding cord 6 . This device 20 comprises an endpiece 22 injection-moulded on the end 8 a in the form of a substantially cylindrical body 221 of circular cross section. Beyond the end 8 a , the body 221 is prolonged by two branches 222 and 223 , between which is defined an aperture 224 , of which the dimensions in the plane of FIGS. 3 and 5 may vary as a function of a possible mutual approach of the branches 222 and 223 which are elastically deformable.
The branches 222 and 223 meet one another in a zone 225 which is opposite the body 221 and from which extend two other branches 226 and 227 , the free ends 226 a and 227 b of which extend at a distance from one another when the endpiece 22 is not stressed, as illustrated in FIGS. 2 and 3 .
The end 6 a of the cord 6 can be engaged in the aperture 224 . The two strands 6 b and 6 c formed by the cord 6 on either side of its part 6 d received in the aperture 224 then extend along the zone 225 and are engaged in a through-gap 228 defined between the branches 226 and 227 . The two strands 6 b and 6 c extend upwards from the portion 6 d of the cord 6 which is received in the aperture 224 .
As illustrated by the arrows F 1 and F 2 in FIG. 2 , the end 6 a can be engaged in the aperture 224 and then the strands 6 b and 6 c can be turned towards the gap 228 which thus forms a housing for receiving these strands.
The central longitudinal axis of the endpiece 22 is designated by X 22 , this axis coinciding with the longitudinal axis X 8 of the heddle 8 .
Each branch 222 and 223 is provided with a part 222 a , 223 a reentrant in the direction of the axis X 22 with respect to the rest of the branches 222 , 223 . These parts 222 a and 223 a thus define two zones 222 b and 223 b recessed with respect to the outer surfaces 222 c and 223 c of the branches 222 and 223 over most of their length.
A metallic sleeve 24 is mounted on the endpiece 22 and is intended for locking the end 6 a of the cord 6 with respect to this endpiece when the adjustment of the height of the heddle 8 has been carried out by setting the position of this end 6 a with respect to the endpiece 22 . In a most advantageous way, the sleeve 24 is made from stainless steel or from a copper-based alloy, such as brass, so that it does not risk rusting, even if the loom M is liable to operate in a damp or aggressive environment. The sleeve 24 has a circular cross section over most of its length, and its wall is thin, its thickness being smaller than 0.3 mm, preferably in the neighborhood of 0.1 mm. In practice, the wall thickness of the sleeve 24 may be selected lower than 0.6 mm.
The end 241 of the sleeve 24 is widened, that is to say is divergent, extending away from its running part 242 . The opposite end 243 is convergent in the direction of the central axis X 24 of the sleeve 24 and extending away from the part 242 .
The length of the sleeve 24 is designated by L 24 . This length is substantially smaller than that of the flexible sheaths used, for example, with the device known from EP-A-0 915 195. In practice, the length L 24 is between 10 and 40 mm, preferably of the order of 20 mm.
The sleeve 24 is provided with three localized dishings 244 uniformly distributed about the axis X 24 and reentrant in the direction of this axis. These three dishings or neckings define the minimized inside diameter of the sleeve 24 , that is to say the nominal outside diameter of a component capable of being received in this sleeve in the region of these dishings.
The body 221 is provided with two teeth 221 a , each defined between a surface 221 b perpendicular to the axis X 22 and a surface 221 c inclined in the direction of this axis, extending away from the aperture 224 .
When the device 20 is to be manufactured, the sleeve 24 is shaped by means of conventional cutting and dishing techniques. It is then slipped onto the end 8 a of the heddle 8 and displaced at a distance from this end in the direction of the eye 8 b . The endpiece 22 is then injection-moulded on the end 8 a . The sleeve 24 can subsequently be returned towards its first position illustrated in FIGS. 2 and 3 , this being possible in spite of the presence of the teeth 221 a because of the inclined nature of the surfaces 221 c which allow the end 243 to pass over the teeth 221 a . Once this passing has taken place, the tooth 221 forms an abutment with respect to a movement of the sleeve 24 in the direction of the eye 8 b . The configuration of FIGS. 2 and 3 is thus assumed.
Alternatively, the sleeve 24 may be kept at a distance from the endpiece 22 or engaged on this endpiece, but without its end 243 going beyond the teeth 221 a.
Once the end 6 a of the cord 6 is put in place and the adjustment of the height of the heddle has been carried out, the cord is cut to length in order to provide the strand 6 b , whilst the strand 6 c prolonged upwards in order to form the intermediate part of the cord 6 . The sleeve 24 is then displaced in the direction of the arrows F 3 , that is to say in a reciprocating movement parallel to the axes X 22 and X 24 , which then coincide, and in a direction moving away with respect to the eye 8 b of the heddle 8 . This makes it possible to reach the second position, illustrated in FIGS. 4 and 5 , in which the end 241 of the sleeve 24 comes to bear against a shoulder 229 formed in two parts 229 a and 229 b on the outer surfaces of the branches 226 and 227 . Thus, the end 241 and the shoulder 229 form an abutment with respect to the displacement of the sleeve 24 from its position of FIG. 2 to that of FIG. 4 . On account of this displacement, the branches 222 and 223 , on the one hand, and the branches 226 and 227 , on the other hand, approach one another, at the same time constricting the aperture 224 and the gap 228 . To be precise, the rigid nature of the sleeve 24 allows it to exert on the branches 222 , 223 , 226 and 227 a centripetal or compressive force E 1 in the direction of the axes X 22 and X 24 , this force being sufficient to block the strands 6 b and 6 c in the gap 228 as a result of the mutual approach of the ends 226 a and 227 a , and to wedge the part 6 d of the end 6 a in the aperture 224 .
In this region, an amplification effect is obtained with regard to the clamping force E 1 which is exerted by the sleeve 24 in the region of the parts 222 a and 223 a in order to “close” the branches 222 and 223 which tend to pivot about their fastening points on the zone 225 . The end 6 a of the cord is thus firmly gripped in the then flattened aperture 224 . Where the strands 6 b and 6 c are concerned, these are likewise firmly pressed against the zone 225 and gripped between the branches 226 and 227 on account of the force E 1 .
As may be gathered more particularly from FIG. 5A , the mutually confronting surfaces 226 b and 227 b of the branches 226 and 227 are concave, with a shape allowing them to center the strand 6 c on the axis X 22 when the force E 1 causes them to approach one another. In the example illustrated in FIG. 5A , the surfaces 226 b and 227 b each comprise two parallel portions connected by means of an inclined portion.
As illustrated in FIG. 5B for a variant of the invention, the surfaces 226 b and 227 b may be substantially in the form of an open V, thus likewise making it possible to center the strand 6 c on the axis X 22.
The cross sections corresponding to FIGS. 5A and 6B are taken in a part of the endpiece 22 where only the strand 6 c is present, the strand 6 b being received in the housing 228 over only part of the height of this housing.
The displacement of the tube 24 from its first position towards its second position makes it possible to bring one of the dishings 244 level with one of the zones 222 b and 223 b of the branches 222 and 223 , thus causing immobilization in the configuration of FIGS. 4 and 5 by the snapping of the sleeve 24 on the endpiece 22 . The clamping force of the sleeve 24 is thus secure.
The zones 222 b and 223 b and the dishings 244 may likewise serve as an abutment with respect to the displacement of the sleeve 24 from its first position towards its second position. In this case, the sleeve is shorter than that illustrated in the figures, in such a way that its front end 241 does not interfere with the shoulder 229 , the stopping of the displacement F 3 of the sleeve from its first position towards its second position being obtained when the dishings 244 engage in the zones 222 b and 223 b.
In any event, the fact that the front end 241 of the sleeve 24 is widened prevents this front end from marking or damaging the plastic forming the endpiece 22 during the displacement of the sleeve from its first position towards its second position. The widened nature of the end 241 is illustrated in the figure as the result of an outward deformation of the end 241 . Alternatively, this widened nature could be obtained by means of an inner chamfer of the end 241 , the outer surface of which would not be deformed.
The immobilization obtained in the configuration of FIGS. 4 and 5 is reversible in that it is possible to displace the sleeve 24 again towards the position of FIGS. 2 and 3 by expelling the dishings 244 from the zones 222 b and 223 b by means of an elastic deformation of the branches 222 and 223 which is of the same type as that which occurs at the termination of the stroke of displacement of the sleeve 24 from its first position towards its second position.
The use of the sleeve 24 makes it possible to control and limit the overall diametral size of the device 20 , the maximum outside diameter D 20 of the device 20 then being determined by the thickness of the branches 226 and 227 , without the sleeve 24 increasing this diameter.
The heddles can thus be laid out in a high density, whilst the risks of premature wear of the hooking devices are reduced or even eliminated.
The body 221 forms, in its part opposite the branches 226 and 227 , a tube of small diameter 221 d connected to the main part of the body 221 by means of a frustoconical zone 221 e convergent in the direction of the eye 8 b . In the configuration of FIGS. 4 and 5 , the outer end surfaces 226 c and 227 c of the branches 226 and 227 are rounded and convergent towards the axis X 22 , opposite the zone 225 , with a substantially frustoconical shape. The upper end of the device 20 , this upper end being defined by these surfaces, is thus shaped so as to limit shocks or friction with adjacent devices when this device is displaced upwards with respect to the adjacent devices. The zone 221 e has the same function when the device 20 is displaced downwards.
In view of its small thickness and of its relatively modest length L 24 , the sleeve 24 is lightweight and does not appreciably increase the inertia of the assembly formed by a cord 6 and by a heddle 8 . On account of the very good definition of the location of the tube 24 in the position of FIGS. 4 and 5 by virtue of the abutment means 229 and 241 and/or 222 b and 223 b , it is easy to check that it is put in place correctly, especially when numerous heddles are juxtaposed in a predetermined configuration, in as much as the corresponding sleeves then have to be substantially aligned.
The mode of displacement of the sleeve 24 from its first position towards its second position and even in the opposite direction makes it possible to consider an automation of the corresponding movement, thus achieving an appreciable timesaving and laborsaving.
On account of the reversible nature of the putting in place of the sleeve 24 in the position of FIGS. 4 and 5 , an adjustment in the length of the cord may be considered, the sleeve 24 being temporarily displaced towards its configuration of FIGS. 2 and 3 and then being returned to its place in its configuration of FIGS. 4 and 5 , without any impairment in the clamping force obtained by means of the sleeve 24 .
FIG. 8 relates to a second embodiment in which the elements similar to those of the first embodiment bear the same references. The aperture 224 of this embodiment is not surrounded completely by material, the branch 223 being interrupted and forming an aperture 223 o for the lateral introduction of the portion 6 d of the cord 6 in the aperture 224 . Once the sleeve 24 is in place, this portion 6 d is gripped in the aperture 224 by the branches 222 and 223 .
In the device of the invention, the part of the body 221 which is injection-moulded on the end 8 a of the heddle is separate from the part which is formed from the elements 222 to 229 and by means of which the end 6 a of the cord is blocked. Thus, the hooking structure of the cord does not risk weakening the connection between the endpiece 22 and the heddle 8 .
The sleeve 24 has been illustrated with a continuous circular cross section. It could be split longitudinally or be formed by the winding of a metal sheet with partial overlap.
The device may likewise serve for the connection between one or more harness cords 6 and a string 4 . In this case, the upper end or upper ends of the cord or cords 6 is or are injection-moulded in the body 221 and the lower end of the string 4 is wedged in the aperture 224 .
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A device for hooking a heddle of a weaving loom of the Jacquard type to a harness cord of the loom that includes an endpiece molded on an upper end of the heddle. The endpiece including an aperture for the passage and wedging of the cord and a housing for receiving two strands of the cord. The device also includes a rigid sleeve reciprocally slidably mounted on the endpiece between a first position, in which it allows access to the aperture, and a second position, in which it covers the aperture and exerts a compressive force for constricting the aperture and blocking access to the lower end of the cord. The device may also be used for hooking one or more cords on a string.
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CROSS-REFERENCE TO RELATED APPLICATION
[0001] This application claims the benefit of U.S. Provisional Application No. 60/796,002, filed 28 Apr. 2006. The disclosure of the above application is incorporated herein by reference.
FIELD OF THE INVENTION
[0002] The present invention pertains to a method of making a reflex insert tool which in turn is utilized to make an optical plastic part, such as a head lamp, or a tail lamp.
BACKGROUND AND SUMMARY OF THE INVENTION
[0003] Automobiles routinely have optical components, such as a rear tail light lens, that are manufactured during an injection molding process. Often these plastic parts have reflective elements or prisms built into their surface, in order to aid in the reflectivity of the lens. During the injection molding process, these prisms become part of the tool's surface which results in the negative of the prisms being projected onto an interior surface of the completed plastic part. The present invention focuses on a method of making a reflex insert tool that is placed in the mold of an injection molding machine in order to make a plastic optical part.
[0004] In the past, reflex insert tools were made by carefully organizing a group of highly machined individual reflex pins. A reflex pin is generally hexagonal or rectangular shaped having a precisely machined prism on one end thereof. The machined reflex pins are arranged in a clamp or a mandrel which in turn is inserted into an electroformed tank for approximately two weeks in order to produce a reflex skin that is a cast off of the prisms of the pins. This step creates what is generally known as an electroformed reflex skin. However, this skin is of insufficient thickness, lacks rigidity, and therefore is unreliable to be used as an insert tool.
[0005] Thus, the next step has been to build up the back surface of the reflex skin. The thickness of the backing preferably is approximately 0.50 of an inch thick. The backing adds rigidity to the reflex insert tool so as to stabilize the insert tool when it is mounted into a mold. Thus, in order to build up the back surface of the reflex skin so as to have sufficient thickness, large electroformed tanks are utilized that are filled with an electroforming bath consisting of nickel, cobalt, etc. This bath produces lower densities than the skin bath and is easier to machine. This building up process takes about 6-7 weeks as the electroforming process is a very gradual process.
[0006] Thus, the problem with utilizing the traditional electroforming process and their associated tanks of metal, is that the electroforming process is time consuming and labor intensive. As such, the traditional process of making a reflex insert tool takes up to twelve weeks. Moreover, the traditional electroforming process is extremely capital intensive as it requires large tanks of liquid electroformable metal that can be a caustic substance. These huge tanks consume large amounts of energy, require several people to operate and to manage, and the backing portion of the electroforming process takes six to seven weeks to complete. It would be desirable to eliminate or at least reduce this entire process.
[0007] Accordingly, it would be desirable to provide an improved method of manufacturing a reflex insert tool which is less capital intensive, requires less manpower and plating time, less expensive machinery, substantially shortens the cycle time for making a reflex tool all the while maintaining photometric performance. It would also be preferred to utilize a cold spray technology during the backing process so as to reduce heat on the reflex skin so as to minimize heat damage and warp age.
[0008] According to one aspect of the present invention, it would be desirable to speed up the process for manufacturing a reflex insert tool by entirely eliminating the electroplating process that was traditionally used to build up the backing on the insert skin.
[0009] According to another aspect of the present invention, a method of manufacturing a reflex insert tool comprises the steps of machining optical pins having a predetermined prism configuration. Said pins are then arranged in a bundle.
[0010] A clamp is provided which is operable to receive the arranged bundle of pins, and thus securely clamping the pins together. The loaded clamp is then placed into the electroformed tank to create an electroformed skin of about 0.140 of an inch thick. The clamp, with its associated electroformed skin, is then removed from the electroformed tank where the electroformed skin is then separated from the clamp.
[0011] A cold spray low pressure technique is next utilized for applying lower density backing material to the underside of the electroformed skin. The cold spray process continues until a predetermined thickness, or build up, is generated on the underside of the reflex insert skin. After the backing material has cured, the backing material is machined to a predetermined thickness and configuration. Thereafter, the profile of the machined reflex insert can be cut by a wire EDM or CNC milling process, and the insert is then ready for insertion into a tool for injection molding an optical part.
[0012] It will be appreciated that this process results in a reflex insert tool that can be used for making an assortment of optical parts. This novel process takes substantially less time than does conventional methods that were used in the past to make optical reflex insert tools. This novel process further utilizes less natural resources, less capital intensive machinery, and is safer to manufacture. This novel process increases the number of reflex inserts that can be manufactured while maximizing the use of existing electroforming tanks, and other resources. For example, because the electroforming tanks are not used for the electroforming the back surface of the skin, the tanks are now freed up for making new skins that can be in turn used to make more reflex inserts. The electroforming tanks are only needed for about two weeks in total for each reflex insert.
[0013] Further areas of applicability of the present invention will become apparent from the detailed description provided herein. It should be understood that the detailed description and specific examples, while indicating preferred embodiments of the present invention, are intended for purposes of illustration only, since various changes and modifications within the spirit and scope of the invention will become apparent to those skilled in the art from this detailed description. It will be appreciated that the present invention can be utilized wherever it is desirable to make a tool for an optical part.
BRIEF DESCRIPTION OF THE DRAWINGS
[0014] FIG. 1 is a perspective view of an optical pin that is used for a reflex insert;
[0015] FIG. 2 is a perspective view of a cluster of optical pins;
[0016] FIG. 3 is a perspective view of the bundle of optical pins organized together and positioned within a clamp, with a portion of the clamp broken away;
[0017] FIG. 4 is a side elevational view of the clamp filled with pins positioned within a tank of electroforming material;
[0018] FIG. 5 is a side elevational view of the newly created electroformed skin once it is separated from the clamp;
[0019] FIG. 6 is a schematic illustration of the cold spray process of applying backing material to the back side of the electroformed reflex insert skin;
[0020] FIG. 7 is a schematic diagram illustrating machining the back side of the electroformed skin;
[0021] FIG. 8 is a schematic diagram illustrating a wire EDM processes cutting out a preferred profile in the machined electroformed skin;
[0022] FIG. 9 is a side view of the finished reflex insert tool in its final form ready to be positioned into a mold;
[0023] FIG. 10 is a side view illustrating a finished molded lens and the reflex insert tool after having been injection molded using the reflex insert depicted in FIG. 9 ; and
[0024] FIG. 11 is a flow chart illustrating the steps for this method of making an optical reflex insert tool.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0025] With respect to FIG. 1 , an optical pin 10 has an elongated steel shaft with a precisely machined prism 12 on one end thereof. The prism 12 is specially configured to take on an optical surface configuration which in turn, is imparted onto an electroformed skin.
[0026] FIG. 2 illustrates a bundle 14 of optical pins 10 that are arranged together in a predetermined configuration. The configuration illustrated is exemplary in nature and it will be appreciated that the bundles can be arranged in a variety of profiles as desired. The bundle of pins 14 are arranged so as to have the respective prisms adjacent to one another.
[0027] FIG. 3 illustrates the bundle of pins 14 secured within a two-piece clamp 16 . The clamp has a first half 18 and second half 20 . The clamp 16 is shown with a cut-away section with the bundle 14 of pins shown positioned within an opening 22 located in the center of the clamp 16 . The clamp 16 has a back surface 24 and a front surface 26 . The clamp 16 is made preferably of stainless steel. Collectively, the clamp 16 and the bundle of reflex pins 14 create a clamped bundle of pins 28 that are ready for insertion into an electroforming tank. In this clamped state, the prisms of the reflex pins create a protruding surface 30 comprising an optical prism surface 32 collectively extending above the front surface 26 of the clamp 16 .
[0028] With reference to FIG. 4 , the clamped bundle of pins 28 is next positioned within an electroforming tank 34 . The clamped bundle of pins 28 is secured via a bracket 36 to a vertical wall 38 of the tank. The tank 34 is filled with electroform bath 40 to a level substantially above the optical prism surface 32 . The preferred electroform bath 40 includes cobalt, nickel and/or a formulation of same. The electroform bath 40 preferably has a sufficiently high density material so as to add rigidity to the electroformed skin. An electroformed skin 42 is shown built up off of the front surface 26 and off of the optical prism surface 32 . The process of forming the electroformed skin accrues over a period of two weeks, in the preferred embodiment. The electroformed skin 42 takes on substantially the same configuration as the front surface 26 and its adjoining optical prism surface 32 . A prism surface 44 is created on the back side 46 of the electroformed skin. A finish surface 48 represents the side opposite the back side 46 .
[0029] With reference to FIG. 5 , the electroformed skin 42 is shown separated from the clamped bundle of pins 28 . The electroformed skin 42 is approximately 0.140 inches thick being preferably made of nickel, or cobalt or an amalgamation of same. The finished side 48 of the electroformed skin now has a negative prism configuration 50 which will be used as the finished surface for molding optical lens parts.
[0030] With reference to FIG. 6 , the step of applying backing material to the electroformed skin 42 is illustrated. It will be preferred that a cold spray welding process be utilized. It is preferred to utilize a cold backing process so as to minimize heat and thus warp age on the negative prism configuration surface 50 . Thus, layers of backing material 52 are built up on the backside 46 of the electroformed skin 42 . This may be accomplished by a cold spray process wherein metal is disbursed in even presentations to the back of the electroformed skin. This may be done by the delivery of metal by a nozzle 54 that is connected to a machine, not shown. It will be preferred that the metal that is used for the backing buildup to have a low density property such that its density is lower than the density of the material comprising the electroformed skin 42 . For example, the backing material 56 could be made of the group consisting of aluminum, zinc, or an amalgamation of same. It is also possible that the metal 56 be a powder mixture when applied. It is preferred that the backing portion 52 be approximately 0.50 of an inch thick.
[0031] With reference to FIG. 7 , a machining step is illustrated showing the removal of the uneven backing portion 52 after the cold spraying step has been completed. It is necessary to provide a smooth surface 58 on the backing portion 52 so that the final reflex insert tool may be properly installed within a mold. A CNC Machine 60 is shown having a tool 62 for cutting away the excess backing material 56 . The electroformed skin 42 is not machined during this step. It will be appreciated that the machining step can be accomplished through other means, as desired.
[0032] With reference to FIG. 8 , the machined reflex insert 64 is now ready for the final machining so that the profile of the insert tool is created. This next step is accomplished by a wire EDM or CNC mill 66 passing through the machined reflex insert 64 so as to cut a desired profile for an insert tool. This causes undesirable material 68 to be cut away from the final reflex insert which ultimately will be placed within a tool for injection molding.
[0033] With regards to FIG. 9 , a finished reflex insert 70 is illustrated and is now ready for insertion into the injection molding tool shown in FIG. 10 . A finished insert 70 has an electroformed skin portion 42 and the associated backing portion 52 . As can be seen in FIG. 10 , the finished reflex insert 70 is located within a core 72 of an injection molding tool 74 . An injected molded plastic optical part 76 is shown having been molded from the tool 74 . The optical part 76 has an optical surface 78 of superior photometric qualities, thus ready for use after trimming and finishing.
[0034] It will be appreciated that the optical part 76 can be utilized in automotive, aeronautical, or wherever it is desirable to produce a part having a highly reflective optical surface of superior photometric qualities.
[0035] With regards to FIG. 11 , the steps for manufacturing a reflex insert tool 70 will be presented. The first step 80 includes manufacturing the optical pins to a desired configuration so as to have an optimal optical surface. The next step includes bundling 82 the optical pins together in an arrangement of a desired configuration. The next step includes clamping 84 the bundled optical pins, so as to securely hold them together for the electroforming stage. The next step includes locating 86 the assembled clamp into an electroformed bath. The clamp containing the pins must be sufficiently submerged within the electroformed bath so as to allow proper material buildup. The electroformed bath preferably includes material such as cobalt and nickel.
[0036] The next step includes building up 88 the electroformed skin to a desirable thickness. It is preferred to continue this electroforming process until the skin has reached approximately 0.140 inches in thickness. The next step includes removing 90 the clamp from the electroformed bath which concludes the step of generating the electroformed skin. The next step includes separating 92 the electroformed skin from the clamp. The clamp retains the bundle of optical pins. The electroformed skin now has an optical surface configured therein that is a take off of the plurality of prisms.
[0037] The next step includes building up 94 a material on the back of the electroformed skin. This is preferably accomplished by applying a cold spray material to the back side of the skin in a rapid manner under a low pressure condition. It will be appreciated then the buildup material be comprised of material such as aluminum or zinc. It is preferred that the backing material have a density less than that of the density of the electroformed material. Providing a lower density backing material aids machining of same, yet providing rigidity to the insert tool. It is preferred that the backing step take a few hours to less than one week.
[0038] The next step includes machining 96 the backing material to a desired thickness and a uniform plane. The last step includes CNC machining 98 the profile of the reflex insert to a desired configuration. The result is a completed finish reflex insert 70 that is ready for insertion to an injection molding tool 74 .
[0039] It will be appreciated that the aforementioned steps may be modified, yet still be within the spirit of the scope of the present invention. It will also be appreciated that the step of applying cold spray material to the electroformed skin substantially reduces the time over conventional methods, for building up the backing portion. It is preferred that the step of applying cold spray material be completed within approximately a one hour time period from beginning to end.
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Manufacturing a reflex insert tool includes the steps of assembling optical pins in a bundle, and inserting same into a mold clamp assembly. The mold clamp assembly is placed into a vat, wherein an electroformed skin is developed which in turn is removed from the bath. A cold spraying technique is utilized applying a build up of material on the back surface of the electroformed skin. The back surface of the reflex insert is then machined and through wire EDM, configured to a desired shape and thereafter ready for insertion into a tool for injection molding plastic parts therefrom.
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This application is a division of application Ser. No. 07/745,480 filed Aug. 14, 1991, U.S. Pat. No. 5,289,207 granted Feb. 22, 1994.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to an ink jet recording apparatus mountable on or connectable to a copying machine, a printer, communication equipment, or information equipment and a recovery method of a recording head applicable thereto. Particularly, the present invention is effective for a compulsory recovery mechanism (either electrical or mechanical) in a device having heat generating elements for forming bubbles in the ink generating thermal energy and a driving circuit for driving them with an electrical pulse signal.
2. Related Background Art
As fundamental inventions for forming bubbles with thermal energy, there are those as driving a heat generating resistor with an electrical pulse signal, or using optical energy, and in addition, having elements for converting the optical energy to heat, as described in U.S. Pat. No. 4,740,796 or West German Offenlegungshrift No. 2,843,064.
In the field of ink jet recordings, the recovery process called a predischarge is performed as a process for discharging the ink from an outlet in other than recording. As the invention for accomplishing this predischarge with an appropriate exhaust of ink including the in-recording or waiting, there is known U.K. Patent No. 2,169,855. In this official gazette, the recovery performed during usual recording as the predischarge is specifically described and stated expressly as the invention.
On the other hand, for the recovery of a recording head in an extreme state, the recovery using a pump ordinarily called suction recovery has been put to practical use, but there is a disadvantage in accomplishing a smaller, lighter or less expensive apparatus because of its complex construction. Also, in U.S. Pat. No. 4,977,459 disclosing that a proper recovery processing is executed in accordance with the state of a recording head, the final compulsory recovery adopts suction recovery, but not predischarge.
Also, a conventional predischarge is performed in an ordinary discharge condition for recording or its similar condition because it is relatively frequently operated. This is to extend the life of heat generating elements for the recording head. The predischarged ink is discharged toward an ink absorbing member, but in addition, specific paper, recording sheet, foam material, and a cap for recording head are known as the ink receiving member.
However, particularly in the bubble jet recording apparatus that forms flying ink droplets by producing ink bubbles by the use of the thermal energy among such ink jet recording apparatuses, the recording quality tends to degrade in a long term of recording.
Thus, as its cause, it is known that dyes or contaminants in the ink are solidified on a face of the heater which is an electricity-heat converter for supplying the thermal energy to the ink, due to the heat, and accumulated thereon. Therefore, large efforts have been made to remove contaminants, such as refining of dyes, so that such deposits may not be produced on the heater face, but there are some cases of making it difficult to use the recording head, because the recording quality is degraded, irrespective of almost no deposits on the heater face in a long term of recording using such ink, and there are no sufficient resolutions for that problem.
Particularly when the recovery can not be made only with a pump given as the compulsory recovery or with plural suction recoveries, there is currently no method or apparatus which allows an effective recovery processing in a short time, but the measure is only taken with a combination of complex processings.
SUMMARY OF THE INVENTION
It is an object of the present invention to provide a method of driving an ink jet apparatus having plural adjacent ink discharge openings, each opening having associated therewith energy generating means for generating energy to discharge ink from the associated opening, the method comprising the steps of selectively driving the energy generating means in a first driving mode to substantially simultaneously discharge ink from every other opening in a first cycle and from remaining openings in a second cycle immediately following said first cycle, the first and second cycles being repeated, and selectively driving the energy generating means in a second driving mode to substantially simultaneously discharge ink repeatedly from a group of adjacent openings in a first cycle and to substantially simultaneously discharge ink repeatedly from the group of adjacent openings in a second cycle beginning a predetermined time after the end of the first cycle.
It is another object of the present invention to provide an ink jet apparatus comprising plural adjacent ink discharge openings, each opening having associated therewith energy generating means for generating energy to discharge ink from the associated opening and control means for selectively driving the energy generating means in a first mode wherein ink is substantially simultaneously discharged from every other opening in a first cycle and from remaining openings in a second cycle immediately following the first cycle, the first and second cycles being repeated, and in a second mode wherein ink is substantially simultaneously discharged repeatedly from a group of adjacent openings in a first cycle and ink is substantially simultaneously discharged repeatedly from the group of adjacent openings in a second cycle beginning a predetermined time after the end of the first cycle.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view showing one example of an ink jet recording apparatus to which the present invention is applicable.
FIG. 2 is a perspective view showing one example of a recovery operation according to the present invention.
FIG. 3 is a perspective view showing a state of another recovery operation according to the present invention.
FIG. 4B is a systematic view showing an ink supply system and a recovery system for the recovery according to the present invention, and FIG. 4A is a partial detail view of a head thereof.
FIG. 5 is a configuration diagram of a circuit for performing the compulsory recovery operation according to the present invention.
FIG. 6 is an explanation view showing an example of dot pattern in performing the compulsory recovery discharge onto a recording medium.
FIG. 7 is an explanation view showing another example of dot pattern in performing the compulsory recovery discharge onto a recording medium.
FIG. 8 is an explanation view showing another example of dot pattern in performing the compulsory recovery discharge onto a recording medium.
FIG. 9 is a schematic view showing an operation panel of a printer to which the present invention is applied.
FIG. 10 is a view showing a specific example of a print pattern when the compulsory recovery discharge is applied.
FIG. 11 is an explanation view showing a specific example of another print pattern.
FIG. 12 is a perspective view of ink withdrawal means in another example of the present invention.
FIG. 13 is a cross-sectional view of FIG. 12.
FIG. 14 is a perspective view of ink withdrawal means in further another example of the present invention.
FIG. 15 is a cross-sectional view of FIG. 14.
FIG. 16 is a perspective view of ink withdrawal means in a still further example of the present invention.
FIG. 17 is a cross-sectional view of FIG. 16.
FIG. 18 is a flowchart for practicing the compulsory recovery mode during the recording in an example of the present invention.
FIG. 19 is a subroutine for the compulsory recovery mode during the non-recording in the example of the present invention.
FIG. 20 is a subroutine for the compulsory recovery mode for maintenance in the example of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
FIG. 1 shows one example of an ink jet recording apparatus to which the present invention is applicable. Here, 1 is an ink jet recording head, 2 is a carriage on which the recording head 1 is mounted, 3 is a connector for supplying an electrical signal for recording to the recording head 1, 4 is a flexible cable for transmitting the electrical signal from a main device to the recording head 1, 5 is a guide shaft for holding the carriage 2 freely movably, 6 is a cap unit having recovery means, 7 is a cap member, 8 is a wiper blade made of a material such as rubber, and 9 is a recording sheet of recording medium held at a position opposed to the recording head 1. Also, 16 is a soft porous member such as urethane foam for removing contaminants or fixed inks on a surface of the head.
Note that FIG. 1 shows a state during the recording operation, in which the recording head 1 is normally positioned opposed to the cap unit 6 in a condition where the power source is off, while if the power is turned on, the head 1 undergoes the automatic recovery operation with the cap unit 6 in a condition in contact with the cap member 7. Specifically, the ink is sucked from the head 1 with a suction pump, not shown, as will be described later, while waiting for a recording signal, and if the recording signal is received, the cap 7 is released from the head 1 and the recording is started.
Note that the recovery discharge according to the present invention (hereinafter referred to as the compulsory recovery discharge to distinguish from the ordinary recovery operation automatically performed when the power is turned on) is performed with a larger energy than the ordinary one, for simultaneously discharging the ink through all discharge ports, in which FIG. 2 shows a state where the compulsory recovery discharge is performed in a first example. Also, the ink compulsory discharge operation for recovery is performed by rising the voltage applied to the head 1 while the pulse width is kept constant, or by using a greater output than for the recording, with an increased pulse width, while the voltage supplied to the head 1 is kept constant. Note that usually after the recording sheet 9 is set on the apparatus, the compulsory recovery discharge is started onto a face of the sheet in a predetermined operation, and after the discharge of a predetermined number of pulses is terminated, it is automatically stopped.
However, in this example, trouble for setting the recording sheet 9 is taken, and further, when the paper width of the sheet 9 is small, a failure may arise that the discharge is made over the paper width, thereby making the inside of the apparatus dirty, so that the compulsory recovery discharge is performed into the cap member 7 as another means. Thereby, it is possible to prevent a disadvantage of making the inside of the apparatus dirty due to maloperation, and shorten the wasteful time such as a sheet feed time.
An example will be described below in which the compulsory recovery operation is performed by discharging the ink into the cap member 7.
The compulsory recovery discharge in this example is performed at a home position, i.e., a position where the head 1 is opposed to the cap member 7, in a predetermined operation. FIG. 3 shows a view in performing the compulsory recovery discharge.
If an instruction of the compulsory recovery operation is given, firstly, the setting is made so as to provide a constant pulse width by rising the voltage supplied to the recording head 1, or an increased pulse width by keeping the head voltage constant, whereby a larger output than for the recording is used. Note that the discharge is performed with the head 1 opened from the cap member 7, the ink exhausted from the cap member 7 is sucked through a suction tube 10 as shown in FIG. 4. In FIG. 4, 20 is a sub ink tank for supplying the ink to the head 1, 21 is an atmosphere opening valve for opening or shutting the interior of the cap member 7 to or from the atmosphere, 22 is a pump for performing the recovery operation, 23 is an ink cartridge, 24 and 25 are an ink bag and a waste ink absorbing member stored in the ink cartridge 23, respectively, and 26 is an ink supply tube, in which the ink is supplied from the ink bag 24 via the tube 26 to the subtank 20, then led to the recording head 1 and discharged.
Also, when the ordinary recovery operation is practiced, the ink is sucked from the head 1 with a negative pressure produced by the pump 22, with the atmosphere opening valve 21 being closed, in which the ink sucked from the head 1 via the cap member 7 is exhausted through the pump 22 into the waste ink absorbing member 25 within the ink cartridge 23.
Next, a specific example of the compulsory recovery discharge will be described in detail. With a liquid channel 2 of the known head 1 is provided a heat generating portion formed between a pair of electrodes E1, E2 provided on a heat generation resistive layer H. This heat generating portion supplies the thermal energy to a heat acting area (in the ink) nearby. Note that this heat generating element is provided with a well-known protective layer C.
In the normal recording with the head 1, the drive for discharging the ink is performed by supplying a driving pulse having a pulse width of 3 μs, a head voltage of 28 V and a frequency of 5.5 KHz, across the electrodes E1, E2. Also, for the head temperature control during the recording, the heat is retained by external heating means mounted on the head 1 or internal heating means within the head 1 not used for the discharge, both not shown, so that it may be at 30° C. in starting. However, if the recording is practiced for a long time (e.g., about 30 to 50 million characters) in this state, burnings of dyes in the ink or deposits of impurities are accumulated on the heat generating element (heater) H, not shown, provided in the liquid channel L, thereby gradually making the forming of bubbles unstable and not providing the normal amount of bubbles, so that fine ink droplets for recording are smaller or the discharge speed of ink droplets is decreased, which may degrade the recording quality.
Conventionally, when the recording quality was degraded or the undischarge occurred, the recovery operation was performed, such that the ink was sucked from the head with the cleaning operation, or the discharge face was wiped with a soft porous member, e.g., urethane foam, but there were some cases where the forming of bubbles might be unstable, which could not be recovered with such cleaning operation. Thus, to meet the condition as previously mentioned, the present invention permits the recovery to the state of substantial initial performance by
1) increasing the driving pulse width, or
2) increasing the driving voltage.
with the compulsory discharge in which a larger energy than the energy given at the recording is supplied to the heat generating portion.
FIG. 5 shows an example of a circuit configuration for performing the compulsory recovery discharge according to the present invention. Here, only the constituents necessary for the recovery operation are shown, in which MPU51 has a clock or timer for controlling various operations for the recording. 52 is an operation panel comprising the keys for specifying a compulsory recovery mode or other modes, in addition to a recording start key, not shown. 53 is a ROM, and 54 is a RAM for storing record data, etc. in which ROM 53 stores a recovery discharge routine in the compulsory recovery mode, or a routine 56 for performing the recovery operation by instructing the MPU51 that the pulse width, the driving voltage and the number of driving pulses should be applied to the discharge energy generating element 55.
Experiments were performed to obtain the above recovery condition, and it was found that 1) as a condition of increasing the driving voltage for the compulsory recovery discharge, providing that the bubble start voltage (minimum discharge voltage) is Vo, it is desirable that the ratio of Vo to the driving voltage, Kv value (V/Vo), is 1.22 to 1.35 (more correctly, the amount of energy can be represented by KV 2 , which is 1.48 to 1.82), and the number of pulses is set in a range from 3×10 5 to 10 6 (the bubble start voltage is a voltage value Vo for a pulse width of 3 μs).
2) as a preferable condition of varying the pulse width for the compulsory recovery discharge, providing that the bubble start pulse width (minimum discharge pulse width) is P TO , the recovery effect can be obtained when the ratio of the driving pulse width P T to P TO , K T value (P T /P TO ), is 1.48 to 1.7; more preferably, with various examinations of changing the lower limit, the level-up can be accomplished as a whole with 1.5 or more magnification, and more preferably, the recovery operation can be more effectively performed with 1.55 or more (note that the bubble start pulse width (minimum discharge pulse width) in 2) is the pulse width P TO for a voltage value of 28 V). Note that the amount of energy has a relation of Kv 2 =K T .
Specific examples are shown below as to the conditions. For an ink jet recording apparatus which was set to record with
Head voltage: 28 V
Discharge driving pulse width: 3 μs
Discharge frequency: 5.5 KHz a method of increasing the voltage for the compulsory recovery discharge was performed with
Head voltage: 30.2 V (bubble start voltage Vo×1.22)
Discharge driving pulse width: 3 μs
Discharge frequency: 4.0 (-5.5 KHz)
Discharge amount: 1×10 6 pulses with all nozzles
It should be noted that the discharge frequency is desirably set at a lower value to prevent nondischarge from occurring due to excessive bubbles.
As a method of increasing the pulse width for the compulsory recovery discharge, an experiment was perfomred with
Head voltage :28 V
Discharge driving pulse width: 3.48 μs (bubble start pulse width×1.48)
Discharge frequency: 4.0 (-5.5) KHz
Discharge amount: 1×10 6 pulses with all nozzles
As a result, the recording quality after the compulsory recovery discharge could be significantly improved as compared with before it. This compulsory recovery discharge method is especially preferable to a recovery method for print deviation when the print is practiced for a long term (with 30 to 40 million characters), but the effects can be sufficiently appreciated even when the recording quality is degraded due to a long storage time.
The results of above experiments are shown in the following table.
TABLE 1______________________________________Recoverability with increasedvoltage (number of experiments n = 10)Number of Number of recoverydischarge discharge pulsespulses Kv 3 × 10.sup.5 5 × 10.sup.5 10.sup.6 Remarks______________________________________1.15 X X X Normal discharge con- dition (pulse width 3 μs fixed)1.20 X X X Normal discharge con- dition (pulse width 3 μs fixed)1.22 Δ ◯ ◯ Normal discharge con- dition (pulse width 3 μs fixed)1.30 ◯ ◯ -- Normal discharge con- dition (pulse width 3 μs fixed)1.35 ◯ -- -- Normal discharge con- dition (pulse width 3 μs fixed)______________________________________ Other Comment: The head temperature is retained at 30° C. in starting. Evaluation ◯: print quality recovered Δ: print quality slightly recovered X: print quality not recovered (bad)
TABLE 2______________________________________Recoverability with increasedvoltage (n = 20)Number of Number of recoverydischarge discharge pulsespulses K.sub.T 3 × 10.sup.5 5 × 10.sup.5 10.sup.6 Remarks______________________________________1.33 X X X Normal discharge condition (voltage 28 V fixed)1.44 X X X Normal discharge condition (voltage 28 V fixed)1.48 Δ ◯ ◯ Normal discharge condition (voltage 28 V fixed)1.70 ◯ ◯ ◯ Normal discharge condition (voltage 28 V fixed)1.82 ◯ -- -- Normal discharge condition (voltage 28 V fixed)______________________________________ Other Comment: The head temperature is retained at 30° C. in starting. Evaluation ◯: print quality recovered Δ: print quality slightly recovered X: print quality not recovered (bad)
TABLE 3______________________________________Recoverability with head temperatureincreased (n = 10)Number of Number of recoverydischarge discharge pulsespulses Kv 3 × 10.sup.5 5 × 10.sup.5 10.sup.6 Remarks______________________________________1.15 X X X (pulse width 3 μs fixed)1.20 X Δ ◯ (pulse width 3 μs fixed)1.22 ◯ ◯ -- (pulse width 3 μs fixed)1.25 ◯ -- -- (pulse width 3 μs fixed)1.30 ◯ -- -- (pulse width 3 μs fixed)______________________________________ Other Comment: The head temperature is retained at 55° C. (The head is retained by using internal heating means within head or external heating means dedicated to the heating which is not used for the discharge). Evaluation ◯: print quality recovered Δ: print quality slightly recovered X: print quality not recovered
Note that as a result of increasing the pulse width while heating the head 1 under the same condition, the effect could be seen when K T lay in a range from 1.49 to 1.7.
As will be clear from Tables 1 to 3, the effect could be seen when Kv value for the voltage was in a range from 1.22 to 1.35 in the case of Table 1. It was found that the input energy into the heater with a Kv value of 1.22 was about 1.5 times the minimum discharge energy, and the recovery was made with a discharge pulse number of 5×10 5 , while the energy with a Kv value of 1.30 was about 1.7 times, and the recovery was made with a discharge pulse number of 3×10 5 . There was the effect when the Kv value was near 1.216, while there was no effect near 1.215. This substantiated the fact that the value of 1.48 times the energy value was critical.
Similarly, when the pulse width in Table 2 was increased, the print quality could be recovered with a K T value of 1.48 or more. This substantiated the condition of the present invention more correctly.
Table 3 shows the results with the head temperature forcibly retained at a high temperature, in which it is found that the input energy can be slightly lowered (Kv=1.20), and the effect can be improved with a reduced number of discharge pulses.
Moreover, the specific operation in the compulsory recovery discharge will be described based on FIG. 3. Here, 11 is an atmosphere communicating tube provided for releasing the pressure within the cap member 7 and connected to an atmosphere opening valve 21 as shown in FIG. 4. When a record start signal is entered to perform the compulsory recovery discharge in a state of FIG. 3, the cap member 7 is retracted to a position a little away (about 0.5 to 2 mm) from the head 1 and placed in a waiting state, holding an orientation to prevent the ink discharge by the compulsory recovery discharge from impinging on an inner face of the cap member and being splashed back.
Thus, the recording head 1 is driven in the above condition, in which the amount of discharge ink with the compulsory recovery is 64×80 pl×10 6 pulses=5.1 cc because one drop volume is about 80 pl/drop in the head for use with this example (having 64 discharge ports). The automatic suction with the suction pump is performed about 11 times because the amount of suction a time with the pump 22 is 0.5 cc/time. (However, the suction is made every time 0.5 cc is reserved, providing that the ink receiving amount with the cap member 7 is more than 0.5 cc in this case.) After the compulsory recovery discharge is terminated, one or more normal recovery operations are made, whereby bubbles remaining within the head 1 or ink droplets adhering to an ink discharge face are removed.
As above described, it has been found that a degraded print quality can be recovered to the initial quality with the compulsory discharge. However, when minute degradations in the print quality are detected, there is a risk of shortening the life of head on its durability if the compulsory discharge recovery is attempted many times.
Therefore, a further experiment was made, and in examining the minimum number of pulses for the recovery of minute degradation while satisfying a condition of 1.48 times for the present invention, with a head which failed to form bubbles at the early time of recording which was discovered in a long storage (left away for 3 months), the recoverability was such that the print quality could be sufficiently recovered to its initial quality with 5.7×10 4 to 1.8×10 5 pulses. Also, if the recovery was once performed in the order of n×10 3 pulses, the recovery effect could be obtained to sufficiently meet the normal continuous recording. Where n is 1≦n<10, and preferably, n=5 or more.
The following method was taken as specific means.
When the user practices the recovery using a recording medium, one sheet (A4 size) is desirable, taking the trouble into consideration, and further, as a result of seeking the number of pulses undoubtedly effective on the durability, the following condition was appreciated as preferable.
Using one sheet of A4 size, print was made 1/2 thinned-out and staggered in 80 columns and 40 lines, with a head temperature of 65° C. retained and a discharge frequency of 5.5 KHz, so that the compulsory recovery discharge pulse number was 5.7×10 4 . The compulsory discharge recovery operation was performed with the method as previously described in FIG. 2. Further, when the discharge for all solid print was made onto one sheet of A4 size, in 80 columns and 60 lines at maximum, 1.8×10 5 pulses are desirable.
Accordingly, the compulsory recovery discharge for the user to recover the print quality is desirable with a pulse number ranging from 5.7×10 4 to 1.8×10 5 pulses, and there is an advantage that the discharge can be more easily confirmed on the recording medium. Note that when the quality can not be recovered with the compulsory discharge recovery, the compulsory recovery discharge with 3×10 5 or more pulses must be performed. Normally, the pulse number is more preferably 1.8×10 5 to 3×10 5 from the viewpoint of the life, and the pulse number exceeding 3×10 5 should be limited to specific occasions such as the maintenance. Specific discharge dot patterns using the recording medium are shown in FIGS. 6 to 8.
FIG. 6 shows a pattern which is printed alternately staggered with a recording head having 12 nozzles (discharge ports) thinned out by 1/2. This pattern has an advantage that the state of dot through each discharge port is easily determinable for the all solid print, and in addition, it is superior in the effect of removing bubbles from other than the heat generating portion. With this pattern, the deformation of recording sheet is prevented and the recovery can be accomplished without inconvenience even if the recording is made on the entire face of recording sheet.
FIG. 7 shows a print pattern in which a recording head having 12 nozzles as in FIG. 6 is caused to continuously print 6 dots with upper and lower half of 6 nozzles each, and this 6×6 matrix is disposed staggered as a whole. With this pattern, the periods of abrupt discharge and pause are alternately encountered, so that the recovery effect can be further improved.
FIG. 8 shows a pattern in which the abrupt discharge and pause of FIG. 7 are alternately performed for all nozzles, and a remarkable effect can be provided because the state of ink can be improved due to multiplication effect of large ink flows within the head caused by the discharge through all nozzles.
In FIGS. 6 to 8, the compulsory recovery method of the present invention using the predischarge onto the recording sheet supplied is taken, wherein the post-processing of ink is eliminated, resulting in a smaller apparatus with reduced frequency of maintenance.
Further, an example in which the compulsory recovery discharge of the present invention is performed onto a paper face of recording medium will be described in detail.
FIG. 9 is a schematic view showing an operation panel of a printer used in the present invention. This printer has three modes for recovery means which are appropriately performed depending on the situation of failure, in which the first mode is a small recovery mode to be performed when the nondischarge of nozzles or deviation occurs, and can be executed with the following operations on the operation panel. If the panel mode is changed with the <SHIFT> key 2, and then the <CLEANING> key 7 is depressed, the cleaning for a head face is practiced with an urethane member 16 (as shown in FIG. 1) and then the suction recovery operation is performed once sequentially.
The second mode is a large recovery mode to be practiced when the recovery is difficult with the first mode, and can be executed with the following operations on the operation panel.
This mode can be performed by depressing the <SHIFT > key 2 and the <CLEANING> key 7 concurrently or continuously, in which the suction recovery operation is performed four times continuously, and then the first mode is performed.
The third mode is a recovery mode with the compulsory recovery discharge of the present invention, which is to be practiced when the print quality is bad even though the undischarge or deviation failure has been recovered with the second mode, and can be executed with the following operations.
This mode can be performed by depressing the <CLEANING> key 7 and the <PITCH/PAPER> key 6 concurrently after the panel mode is changed with the <SHIFT> key 2. That is, a paper is fed and the predischarge is performed to print a predetermined pattern with a predetermined number of pulses satisfying 1.48 multiplication condition as above described. With a constitution that when there is no paper of recording medium set, a paper sensor, not shown, is operated to automatically feed the paper, it will be understood that the paper is necessarily fed whenever the compulsory recovery discharge is executed, so that the ink contamination on the platen is avoided. When started, the compulsory recovery discharge is performed after the specific character notation is recorded, as shown in FIG. 10, whereby it can be seen that the compulsory recovery discharge is being executed. (The dot pattern used in the compulsory recovery discharge is one as shown in FIG. 6.)
After the compulsory recovery discharge is terminated, the paper is automatically exhausted, and then recovery means in the first mode is operated, thereby removing inks adhering to the neighborhood of nozzles or bubbles remaining within the head.
FIG. 11 is another example different from FIG. 10, in which the user can confirm the state of the compulsory recovery discharge, and know remaining lines. In FIG. 11, a reliable recovery can be also accomplished while informing the user that the compulsory recovery mode is being performed, as in FIG. 10.
In the example in which the predischarge was made into the cap as previously described, the recovery discharge was performed with the head and the cap separated by a fixed distance, but as another example, they do not have to be necessarily separated away, and it is also possible that the compulsory recovery discharge can be performed with the head 1 and the cap member 7 placed in contact with each other.
In this case, it is performed by having the atmosphere communicating tube 11 opened with the atmosphere opening valve 21, and sucking only discharged ink with the operation of the pump 22 as shown in FIG. 4. However, in this case, if an inner wall face of the cap is close to a discharge face, it is apprehended that discharged ink droplets are splashed back to adhere to the discharge face of the head 1, which may cause the nondischarge if largely accumulated, whereby it is desirable to open the atmosphere opening valve 21 at fixed intervals and suck the ink from the head 1 to prevent the occurrence of nondischarge.
As a further another method, the ink is sucked through the discharge port of the head 1 by performing the suction operation automatically by means of the pump 22 with the atmosphere communicating tube 11 held in closed state, while at the same time the compulsory recovery discharge can be performed with the pulse width or voltage as previously described. This method has advantages that the nondischarge can be eliminated through the discharge port of the head 1, and further the ink is prevented from splashing out of the cap member 7.
While in the above example, waste ink reversed within the cap member 7 in the compulsory recovery discharge is automatically sucked, waste ink is not necessarily received into the cap member 7, but for example, it can be received into an ink withdrawal box provided apart from the cap member 7, as shown in FIGS. 12 and 13. That is, in this example, the ink discharged with the compulsory recovery is received through an opening portion 14 of the ink withdrawal box 13 to be absorbed into an ink absorbing member 15, and accumulated in a lower side to be exhausted into a suction tube 10. Note that in the ink jet recording apparatus of the continuous system, the ink discharged with the compulsory recovery can be withdrawn for reuse.
FIGS. 14 and 15 show further another example of the present invention. In this example, to receive waste ink in the compulsory recovery discharge, the ink absorbing member 15 is provided within the cap member 7 and by discharging the ink toward the ink absorbing member 15, the splashing of ink can be avoided. Note that the ink absorbing member 15 is attached to keep a sufficient space at the position opposed to an array of discharge ports, in order to make it easier to receive the ink discharged with the compulsory recovery through the array of discharge ports and make it possible to prevent the ink from scattering outward. However, in this case, in performing the compulsory recovery discharge, the discharge face of the recording head 1 is kept in closed state by the cap member 7, or a slight amount of space may be provided therebetween.
FIGS. 16 and 17 show a form of the cap member 7 in still another example of the present invention.
In this example, an ink receiving groove 12 is provided in the cap member 7, a taper face 12A is formed inwardly of the ink receiving groove 12 as shown in FIG. 17, to receive discharged ink droplets on this taper face 12A and lead them downward. Thus, it is desirable to form at least the taper face 12A of a material which can easily receive ink droplets. In this way, this example can prevent the ink from splashing back on the cap member 7, so that no splashed ink may adhere to the recording head.
With the compulsory recovery into the cap, it is preferable to discharge the ink corresponding to an ink receiving volume of the cap itself if no other ink suction means acts on the cap. This is because the compulsory recovery can be securely accomplished exceeding the usual predischarge. In this example, for the cap having the absorbing member internally, preferred results could be obtained by supplying pulses in the order of 10 3 to each discharge portion.
Next, an example of a preferred sequence according to the present invention will be described using Table 4.
TABLE 4__________________________________________________________________________Rom Pulse Number of Dischargename Mode name energy pulses destination__________________________________________________________________________Recovery Mode 1 Normal Eo × 1.1 10.sup.2 or Within capmeans recovery less (or absorbing member) Mode 2 Compulsory Eo × 1.48 n1 × 10.sup.3 Within cap recovery 1 or more (or absorbing member) Mode 3 Compulsory Eo × 1.48 n2 × 10.sup.3 - Recording recovery 2 or more M.sub.1 × 10.sup.5 sheet Mode 4 Maintenance Eo × 1.48 M.sub.2 × 10.sup.5 Recording only or more sheet__________________________________________________________________________
Note that M 1 , M 2 are such that 1≦M 1 <M 2 <10, and n1, n2 are also such that 1≦n<n2<10. Eo is the minimum energy for producing bubbles with which the ink can be discharged. In Table 4, recovery means of the present invention has a ROM for execution of each mode. Each ROM can be selected by a single key input signal as previously described or in combination thereof, but this example is met with either selection means, and has a feature in the mode switching itself. Each ROM will be described below.
ROM in mode 1 is selected in the normal recovery mode, the content of which is such that 10 or less pulses with a pulse energy of Eo×1.1 are supplied to each heat generating element. In this mode, predischarged ink is received into the cap for head (or the ordinary absorbing member for withdrawal).
ROM in mode 2 is selected in the compulsory recovery mode 1 which is executed in a recording flowchart. Its content is such that n1×10 3 pulses with an energy of Eo×1.48 or more are supplied to each heat generating element. This mode has the same discharge destination as in mode 1.
ROM in mode 3 is selected in the compulsory recovery mode 2 for the non-recording in which the predischarge is performed onto a recording sheet during the non-recording, i.e., with no recording based on the record signal. This ROM is to supply n2×10 3 to M 1 ×10 5 pulses (usually the order of 10 4 is preferred) with an energy of Eo×1.48 or more to each heat generating element. Comparing mode 2 and mode 3, with a constitution capable of performing both modes, n1<n2 is a preferably condition. This is a necessary condition for stabilizing the life because excessive recovery is unnecessary and the frequency of mode executions is increased during the normal recording.
ROM in mode 4 is useful for the predischarge onto the recording sheet for maintenance only, in which its condition is the severest. That is, the energy condition is Eo×1.48 or more and M 2 ×10 5 pulses are supplied to each heat generating element. Here, M2>M1 for M1 in mode 3. In mode 3 for use with the user, pulses in the order of 10 4 are supported from the viewpoint of a higher life and a sufficient efficiency.
In this way, the present invention can be sufficiently accomplished as the ink jet recording apparatus itself has a given condition for each mode with a reference of Eo as above mentioned, irrespective of the form of the recording head.
FIGS. 18 to 20 show flowcharts of the example according to the present invention, and its subroutines, represented as the execution flow of contents described in Table 4. In this example, the control sequence is satisfied by prestoring those flows in memory even though there are not a plurality of ROMs.
FIG. 18 shows a main flow, FIG. 19 shows a compulsory recovery mode execution subroutine and, FIG. 20 shows a maintenance mode.
In FIG. 18, a printer is turned on, and at the same time, at step S1, the compulsory recovery mode is executed in such a way as to perform the predischarge into the cap or absorbing member by supplying Y1×10 3 shots of pulses with an energy of more than Eo×1.48 times to each heat generating element. Where 1≦Y1<10.
Then, the routine proceeds to step S2 for deciding whether or not a print signal exists, in which if recording, a sheet is fed (step S3), and the recording is executed (step S4). At decision step S5, it is decided whether or not the recording is terminated, and at decision step S8, if the usual recovery is required during the recording, the usual predischarge is performed (step S9). After recording, at step S6, the sheet is exhausted, and then, at step S7, the compulsory recovery is performed (Y2×10 3 shots of pulses with an energy of more than Eo×1.48 times are given to each heat generating element). This compulsory recovery is sufficient with either one, and can decrease the required number of compulsory recoveries by a user instruction or for maintenance. Note that Y2 satisfies 1≦Y2<10, and is also effective with Y2=Y1, but if both of them are performed, Y2 is sufficient for Y2<Y1.
The compulsory recovery in FIG. 19 is performed in the non-recording mode, in which it is continuously decided whether or not the compulsory recovery is instructed, at step SA1, and if instructed, it is decided whether or not the recording is terminated, at step SA2. Afterwards, if recording, the compulsory recovery can be executed after waiting for the termination of recording, or as in this example, the recording sheet is forcibly exhausted (step SA3) and a new recording sheet for the predischarge is supplied (step SA4).
If the supply of sheet is confirmed, the recovery with a predetermined pattern onto the sheet face is performed by supplying N1×10 4 shots of pulses with an energy of more than Eo×1.48 times to each heat generating element (step SA5). After termination of its pattern, the sheet is exhausted, at step SA6, and the routine waits, at step SA1. Where 1≦N1<10.
On the other hand, the maintenance flow for service in FIG. 20 does not have to be always operated as the subroutine, but is sufficient if it is operable only in the abnormal state of the apparatus or maintenance state. In FIG. 20, because of the non-recording state, it is decided whether or not designating signal is discriminated, at step SB1, and then the sheet is fed (step SB2).
In this maintenance mode, pulses with an energy of Eo×1.48 times are issued in the order of 10 5 . Accordingly, 1≦N2<10.
As shown in FIGS. 18 to 20, an excellent recovery sequence can be obtained by programming the variable number of execution pulses for each compulsory recovery.
The present invention brings about excellent effects particularly in a recording head or a recording device of the system of discharging the ink with bubbles formed by the thermal energy proposed by CANON INC. among the various ink jet recording systems. With such a method, the higher density and definition of recording can be accomplished.
As to its representative constitution and principle, for example, one practiced by use of the basic principle disclosed in, for example, U.S. Pat. Nos. 4,723,129 and 4,740,796 is preferred. This system is applicable to either of the so-called on-demand type and the continuous type. Particularly, the case of the on-demand type is effective because, by applying at least one driving signal which gives rapid temperature elevation exceeding nucleate boiling corresponding to the recording information on electricity-heat converters arranged corresponding to the sheets or liquid channels holding a liquid (ink), heat energy is generated at the electricity-heat converters to effect film boiling at the heat acting surface of the recording head, and consequently the bubbles within the liquid (ink) can be formed corresponding one by one to the driving signals. By discharging the liquid (ink) though an opening for discharging by growth and shrinkage of the bubble, at least one droplet is formed. By making the driving signals into pulse shapes, growth and shrinkage of the bubble can be effected instantly and adequately to accomplish more preferably discharging of the liquid (ink) particularly excellent in response characteristic. As the driving signals of such pulse shape, those as disclosed in U.S. Pat. Nos. 4,463,359 and 4,345,262 are suitable. Further excellent recording can be performed by employment of the conditions described in U.S. Pat. No. 4,313,124 of the invention concerning the temperature elevation rate of the above-mentioned heat acting surface.
As the constitution of the recording head, in addition to the combination of the discharging orifice, liquid channel, and electricity-heat converter (linear liquid channel or right-angled liquid channel) as disclosed in the above-mentioned respective specifications, the constitution by use of U.S. Pat. Nos. 4,558,333, or 4,459,600 disclosing the constitution having the heat acting portion arranged in the flexed region is also included in the present invention. In addition, the present invention can be also effectively made the constitution as disclosed in Japanese Laid-Open Patent Application No. 59-123670 which discloses the constitution using a slit common to a plurality of electricity-heat converters as the discharging portion of the electricity-heat converter or Japanese Laid-Open Patent Application No. 59-138461 which discloses the constitution having the opening for absorbing pressure wave of heat energy correspondent to the discharging portion. That is, according to the present invention, the recording can be surely and effectively accomplished, irrespective of the form of the recording head.
Further, the present invention can be effectively applied to the recording head of the full line type having a length corresponding to the maximum width of a recording medium which can be recorded by the recording device. As such a recording head, either the constitution which satisfies its length by a combination of a plurality of recording heads or the constitution as one recording head integrally formed may be used.
In addition, among the above-mentioned serial types, the present invention is also effective in using a recording head fixed to the main device, a recording head of the freely exchangeable chip type which enables electrical connection to the main device or supply of ink from the main device by being mounted on the main device, or a recording head of the cartridge type integrally provided with an ink tank on the recording head itself.
Also, addition of a restoration means for the recording head, a preliminary auxiliary means, etc. provided as the constitution of the recording device of the present invention is preferable, because the effect of the present invention can be further stabilized. Specific examples of these may include, operation means at the power on, for the recording head, capping means, cleaning means, pressurization or suction means, electricity-heat converters or another type of heating elements, or preliminary heating means according to a combination of these, and it is also effective for performing stable recording to perform preliminary mode which performs discharging separate from recording.
As to the type or number of recording heads mounted, only one recording head is provided corresponding to a monochromatic ink, or a plurality of recording heads can be provided corresponding to a plurality of inks different in recording color or density. That is, as the recording mode of the recording device, the present invention is extremely effective for not only the recording mode only of a primary color such as black etc., but also a device equipped with at least one of plural different colors or full color by color mixing, whether the recording head may be either integrally constituted or combined in plural number.
In addition, though the ink is considered as the liquid in the described examples of the present invention, the present invention is applicable to the ink solidifying at or below room temperature, and liquefying or liquid at the room temperature, or the ink liquefying when a recording enable signal is issued, as it is common to control the viscosity of ink to be maintained within a certain range for stable discharge by adjusting the temperature of ink in a range from 30° C. to 70° C. in the ink jet system. In addition, in order to avoid the temperature elevation due to the heat energy by positive utilization of the energy for the change of state from solid to liquid, or to prevent the evaporation of ink by using the ink solid in the shelf state, the ink which has a property of liquefying only with the application of heat energy, such as the ink to be discharged as the liquid because the ink liquefies with the application of heat energy in accordance with a recording signal or already solidifies when reaching a recording medium, is also applicable to the present invention. In this case, the ink may be in the form of being held in recesses or through holes of porous sheet as liquid or solid matter, and opposed to electricity-heat converters, as described in Japanese Laid-Open Patent Application No. 54-56847 or Japanese Laid-Open Patent Application No. 60-71260. The most effective method for inks as above described in the present invention is one based on the film boiling as above indicated.
Further, a recording apparatus according to the present invention may be used in the form of an image output terminal in the information processing equipment such as computer, a copying machine in combination with a reader, or a facsimile terminal equipment having the transmission and reception feature.
As described above, according to the present invention, the recording quality can be improved by applying a predetermined number of pulses with the energy exceeding 1.48 times the minimum electrical energy to be supplied to the discharge energy generating element during the usual recording, to the discharge energy generating element of the recording head, when the recording quality is degraded due to discharge failure. Also, by automatically sucking the ink reserved within the cap member at the same time while discharging the ink into the cap member, with the compulsory recovery discharge, the recovery operation can be practiced simply without making the surroundings of the apparatus dirty.
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An ink jet apparatus comprises plural adjacent ink discharge openings arranged in a line, each opening having associated therewith an energy generator for generating energy to discharge ink from the associated opening. The energy generators are selectively driven in a first mode wherein ink is simultaneously discharged from every other opening in a first cycle and from remaining openings in a second cycle immediately following the first cycle, the first and second cycles being repeated, and in a second mode wherein ink is simultaneously discharged repeatedly from a group of adjacent openings in a first cycle and is simultaneously discharged repeatedly from the group of adjacent openings in a second cycle beginning a predetermined time after the end of the first cycle.
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FIELD OF THE INVENTION
This invention relates in general to thermographic imaging systems and more particularly to improved processing temperature uniformity in heated drum processors for thermally processed thermographic imaging media.
BACKGROUND OF THE INVENTION
Photothermography is an established imaging technology. In photothermography, a photosensitive media is exposed to radiation to create a latent image which can then be thermally processed to develop the latent image. Devices and methods for implementing this thermal development process are generally known and include contacting the imaged photosensitive media with a heated platen, drum or belt, blowing heated air onto the media, immersing the media in a heated inert liquid and exposing the media to radiant energy of a wavelength to which the media is not photosensitive, e.g., infrared. Of these conventional techniques, the use of heated drums is particularly common.
A common photosensitive media useable in these imaging processes is known as a photothermographic media, such as film and paper. One photothermographic media has a binder, silver halide, organic salt of silver (or other deducible, light-insensitive silver source), and a reducing agent for the silver ion. In the trade, these photothermographic media are known as dry silver media, including dry silver film.
In order to precisely heat exposed photothermographic media, including film and paper, it has been found to be desirable to use electrically heated drums. An apparatus employing this technique, a cylindrical drum is heated to a temperature near the desired development temperature of the photothermographic media. The photothermographic media is held in close proximity to the heated drum as the drum is rotated about its longitudinal axis. When the temperature of the surface of the heated drum is known, the portion of the circumference around which the photothermographic media is held in close proximity is known and the rate of rotation of the drum is known, the development time and temperature of the thermographic media can be determined. Generally, these parameters are optimized for the particular photothermographic media utilized and, possibly, for the application in which the photothermographic media is employed.
U.S. Pat. 5,580,478, issued Dec. 3, 1996, inventors Tanamachi et al., discloses a temperature controlled, electrically heated drum for developing exposed photothermographic media. A cylindrical drum has a surface and is rotatable on an axis. An electrical heater is thermally coupled to the surface of the cylindrical drum.
Separate electrical resistance heaters heat a central heat zone and contiguous edge zones.
The present medical imaging film used can draw relatively significant amounts of heat from the processor drum surface as it first contacts the drum and warms up. Current drum processors typically use a circumambient (circumferentially uniform) internal drum heater. Normal heating devices include resistive element blanket heaters attached to the drum or lamp type radiative devices located in the drum core. Circumambient heaters can cause locations of the drum to under heat and over heat when film enters the processor. In locations of early film contact, where the most significant heat load takes place, the drum temperature can decrease while in other locations the drum temperature can increase because it is not loaded as much. The temperature controller does not correct this. In a closed loop temperature control setup, the drum temperature can be controlled to a tight temperature variation at a location on the drum, but the overall drum temperature will still vary because of the non-even heat load as the film is applied to the drum. There is thus a need for an improved heated drum for processing media which has improved processing temperature and uniformity.
SUMMARY OF THE INVENTION
According to the present invention, there is provided a solution to the problems and a fulfillment of the needs discussed above.
According to a feature of the present invention, there is provided in a thermographic imaging system in which exposed thermographic imaging media is moved along a path, apparatus comprising; a movable member of thermally conductive material located along said path, said member having a first dimension parallel to said path and a second dimension perpendicular to said path, said member having a first side which thermally contacts media moved along said path and a second opposite side, a first electrical heater in thermal contact with said second side of said member; a second electrical heater in thermal contact with said second side of said member, said second electrical heater having a plurality of separately activated segments extending in said first dimension; and a control for selectively activating said segments as media is moved along said path into contiguity with each said segments.
ADVANTAGEOUS EFFECT OF THE INVENTION
The invention has the following advantages.
1. Improved processing temperature uniformity in thermographic imaging systems.
2. Improved media uniformity.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a diagrammatic view of an embodiment of the present invention.
FIGS. 2 and 3 are graphical views useful in explaining the operation of the present invention.
FIG. 4 is a block diagram of a control logic system for the present invention.
FIG. 5 is a diagrammatic view of another embodiment of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
In general, according to the present invention, there is provided an improved heated drum for thermally processing exposed thermographic imaging media. Improved processing temperature uniformity has resulted in improved media uniformity. The heated drum includes a first electrical heater which extends around the drum's internal circumference and which is activated substantially continuously. A second electrical heater extends around the drum's internal circumference but is circumferentially segmented so that segments are activated as media comes into contact with the drum.
Referring now to FIG. 1, heater drum 10 includes a cylindrical drum 12 of thermally conductive material such as aluminum. A first electrical heater 14 (layer 1 ) and second electrical heater 16 (layer 2 ) are in thermal contact with the inner surface 19 of drum 12 . Second, electrical heater 16 includes twelve circumferentially positioned segments S 1 , . . . , S 12 , which are individually activated as media 18 comes into contact with the outer surface 20 of drum 10 . Drum 10 has a first or circumference dimension parallel to the path of movement of a media 18 in contact with drum 10 and a second or width dimension perpendicular to the first dimension.
These two layers 14 and 16 can sometimes be manufactured into one layer depending on heater wire sizes and routing restrictions, but can still act independently. The drum 10 operates typically under two different states: idle and load. The idle state is the case where there is no film 18 contacting drum 10 , and the load state is the case where film 18 is contacting the drum 10 . The idle layer (layer 1 ) 14 represents the current technology where, for example three heater zones coexist with three RTD sensors connected to independent temperature controllers as shown in FIG. 5, heaters 14 , 16 are depicted in a stretched out state before formation into cylinders affixed to the inner surface 19 of drum 12 . The three zones are for the left, center and right crossweb locations along the drum 10 . Each zone (Z 1 , Z 2 , Z 3 ) in the idle layer 14 has a constant heat flux pattern along the downweb or circumferential direction. The load heater layer (layer 2 ) 16 provides the extra heat energy needed when the film 18 is being processed. This layer 16 is broken into load segments or zones around the drum's circumference. FIG. 1 shows the segments broken into 12 arcs (S 1 , S 2 , . . . , S 12 ), each 30 degrees in angle. The segment number total depends on the drum's rotation speed, diameter and heat load and was optimized through trial and error in this case. As the film 18 enters the rotating drum 10 , the first load segment (S 1 ) activates nearest to the film's lead edge. Next, the second load segment (S 2 ) activates when the film reaches it. This process continues until a specific number of segments is reached in arc length. In FIG. 1, two segments make up that number and activate between locations P 1 and P 2 . When this length is reached, the first load segment (S 1 ) shuts off and the next load segment (S 3 ) is turned on. The process stops when the tail end of the film 18 enters the drum 10 and the load segment adjacent to this location is powered on and then off for a period of time that is consistent as part of the normal sequence which is then terminated. Each segment ideally provides enough extra heat energy to heat the film at that arc segment location. The number of heater load segments activated at a time must be calculated. Ideally, there would be a high number of segments present, but this is not practical from a cost standpoint. Numerical simulation has shown that 30 degree arc segments will work with an eight inch outer diameter drum rotating at two RPM with no more than two segments activated at a time when the medical imaging film is processing.
A time dependent, two dimensional finite element model was constructed. It simulated an eight inch round thermal processor heating an eight mil. thick, 17 inch long sheet of polyester base film in the downweb direction. The drum was made of aluminum and was 0.25 inches thick. It used a dual layer idle and load segmented heater attached to the inner aluminum surface of the drum. The load heater was segmented into 12 arcs like FIG. 1 shows. A discreet proportional controller was simulated to control the drum temperature. In the model, the controller responded by measuring the average temperature around the inner aluminum circumference of the drum. The proportional bandwidth and controller cycle time were optimized to reduce controller temperature variation. No temperature sensors were needed for the load heater layer because this layer is only activated by film presence. Film was applied to the drum using gap conduction elements in the locations of contact. The film's wrap angle about the drum was 180 degrees (between P 1 and P 3 in FIG. 1 ). The silicone surface of the drum and the film were subjected to air convection boundary conditions modeled after Newton's cooling law to simulate normal heat loss in their respective environments. The air convection boundary conditions were applied uniformly to the drum and film surface. In locations where the film was in contact with the drum, the convection on the film from that surface was removed. The ambient temperature of the film was lower than the drum.
Four heater configuration results are graphed from the numerical model in FIG. 2 . In the graph, the horizontal axis represents the length of film processed from head to tail. The film was 17 inches long. The vertical axis represents the final temperature the film reached on the drum just as it detached from the drum surface (finished processing). This graph essentially shows how uniform a piece of film is processed on the drum. The flatter the line, the more uniform it is processed.
The first case is the Uniform Heater. This would be the style of drum 10 with a circumambient heat flux single layer blanket heater 14 attached to the inner surface of the drum 10 . In this case, the film temperature begins to fall as the film 18 is processed after which the temperature then increases at a slow then faster rate. The initial temperature fall off is a response to the drum 10 being cooled by the film in a localized region and the temperature controller increasing its duty cycle to counteract. The entire inner surface of the drum 10 is heated. Because only a local region is cooling, the controller does not respond as strong as necessary. As the film 18 continues to load the drum 10 , the controller continues to heat the drum 10 . This heating effect catches up as new film 18 is applied and eventually the new film is warmed to a higher temperature than the previous section film 18 because the drum's temperature is increasing where new film 18 is being applied. The effect is very prominent for the tail section of film 18 because a significant section of the drum 10 has now been heated but no new film 18 is being applied and cooling the drum 10 . The hottest section of the drum 10 heats the last section of film 18 .
The second and third case results add a segmented load heater 16 . One has 60 degree arc segments and the second has 30 degree arc segments. The segments as discussed previously switch on one-by-one as the film 18 is loaded onto the drum 10 . Two segments are powered on for the 30 degree and one single segment for the 60 degree heater. Under these conditions, the amount of power produced by the load heater segments turned on is set to ideally equal the amount of power the film 18 draws from the drum 10 . Heat flux values for the load heater segments are then derived from this requirement. Once the film's tail edge passes the midpoint of the last heater zone segment that contacts it, the load heater switching sequence terminates. The 30 degree segment version produce very uniform processed film. The 60 degree case appeared to produce a temperature oscillation pattern that was not as optimal but still better than the original uniform heater.
For the fourth case, as can be done with numerical models, an ideal heater was modeled where the inner drum temperature was fixed to the controller temperature set point. This simulated a heater with a continuously varying watt density profile that changed as the film loaded onto the drum. This result shows what potential a special heater which followed the heat load profile of the drum could do.
Another important feature of the segmented heater is that it reduces the duty cycle variation for the controller. With a uniform heater, the temperature controller monitors the two distinct load states of idle and load. The controller naturally increases its duty cycle when the load state occurs. The amount it increases is a function of how much more power is necessary and how much power is available. The load heater reduces the duty cycle change of the controller between states.
FIG. 3 shows the heater duty cycles for the first three case results presented. The film 18 contacts the drum 10 at time zero. The film 18 dwells on the drum 10 for 15 seconds. The wrap angle and the film length were previously shown. With a uniform heater, the duty cycle increases from approximately 11 percent to 50 percent. The segmented heater cases reduced the duty cycle variation significantly. During the load state's midway point in time, the duty cycle equaled the idle state value indicating that load heaters were matched to the film heat load. The 30 degree case was better than the 60 degree case.
To build a segmented drum heater several parts are required. A sensor is needed to detect drum position. Another sensor is needed to detect film presence. The load heater would connect to a power controller with logic switches activating each segment when necessary. The duty cycle of this power controller either would be turned to a specific value depending on film load or actively adjusted based upon some feedback signal device. One feedback signal device is the idle heater duty cycle control value. As the idle heater duty cycle increased, the load duty cycle could increase and vice-versa. The idle heater duty cycle ideally does not change when the load beaters segments are activated when film is present.
Referring now to FIG. 4, there is shown a block diagram of a controller for controlling the heating of heater drum 10 . As shown, controller 50 includes temperature sensor 52 , temperature controller 54 , logic board 56 and relays 60 1 , 60 2 , . . . , 60 N Temperature sensor 52 provides the temperature of drum 10 to temperature controller 54 which controls the temperature of first electrical heater 14 . Logic board 56 activates relays 60 1 , 60 2 , . . . , 60 N to provide electrical power to segments 1, 2 , . . . N when a segment of second electrical heater 16 (layer 2 ) is between locations P 1 , and P 2 on drum 10 (FIG. 1 ).
Although the invention has been described as including a heated drum, other continuous members can also be used such as a continuous thermally conductive belt which is heated by said first and second electrical heaters.
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.
10 drum
12 cylindrical drum
14 first electrical heater
16 second electrical heater
18 film
19 inner surface of drum 12
20 outer surface of drum 12
50 controller
52 temperature sensor
54 temperature controller
56 logic board
60 relays
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A thermographic imaging system in which exposed thermographic imaging media is moved along a path, apparatus comprising: a movable member of thermally conductive material located along said path, said member having a first dimension parallel to said path and a second dimension perpendicular to said path, said member having a first side which thermally contacts media moved along said path and a second opposite side, a first electrical heater in thermal contact with said second side of said member; a second electrical heater in thermal contact with said second side of said member, said second electrical heater having a plurality of separately activated segments extending in said first dimension, and a control for selectively activating said segments as media is moved along said path into contiguity with each said segments.
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BACKGROUND OF THE INVENTION
It is known in the art to contain fluids under high pressure in conduits and vessels formed by mating two or more parts or to prevent such fluids from entering the conduits or vessels from outside. It is further known that in order to prevent leakage of such fluid at the mating surfaces of the parts, a deformable sealing element made of an elastomeric material can be provided to fill the space through which leakage might otherwise occur.
Deformable sealing elements, when subjected to high pressure differentials, tend to extrude through a clearance between the mating surfaces thereby compromising the integrity of the seal. Prior art solutions for the problem of seal extrusion have included the use of additional sealing components in the form of back-up washers. O-ring's have also been disposed in close-tolerance rectangular grooves to alleviate the problem of seal extrusion.
In addition to O-rings, prior art designs utilized in sealing applications have included lip seals and gaskets. However, all of these approaches have shortcomings. An O-ring profile, although simple and versatile, is impractical for sealing extensive irregular areas. The preparation of an O-ring that will remain in place when subjected to large pressure differentials is difficult as is its installation which is likely to be done incorrectly. Moreover, a close-tolerance rectangular groove is difficult to maintain, requires large amounts of space in the carrier, and concentrates stresses at corners of the groove. An O-ring seal will be subject to extrusion where an excessive gap exists between mating surfaces.
A sometimes more effective solution than those discussed above is sometimes provided by a lip seal profile. A lip seal profile, i.e., one which employs a flap, is capable of developing good contact under stress when mechanically loaded. However, a lip seal is also not without substantial limitations.
A lip seal becomes energized by the fluid pressure it is designed to contain rather than by mechanical loading. As the fluid pressure increases, a greater force is applied from within the hollow of the lip-seal against its flaps thereby increasing the seal's contact stress. As the fluid pressure increases so does the contact stress.
A lip seal is limited to effective sealing in only one direction. Additionally, the manufacture of lip seal elements which require molding of “flap” geometry undercuts to suit each specific application can be costly. Furthermore, a lip seal can be damaged if a small portion is mechanically loaded, for a period of time, prior to its installation in its intended environment. Such damage typically occurs during manufacturing, shipping, and/or storage.
Gaskets, as well as other designs known to the art, are susceptible to damage by excessive mechanical loading. The polymeric material of a such a seal is typically incompressible. If the seal is subjected to excessive compressive forces in the application, the seal is likely to mechanically fracture since it is forced to extrude under the compressive load. Such damage often occurs during installation in the application.
Finally, in the presence of a pressure differential, prior art profiles are subject to continuous and/or intermittent strain relaxation, (“creep”, “extrusion”) in the absence of back-up washers or a close tolerance groove to provide lateral restraint to the sealing element. However, the use of a back-up washer introduces an additional component with its attendant cost and the increased complexity of the interaction between the sealing element and washer. A rectangular groove, normally required to support a back-up structure, does not fully protect the seal from extrusion. Irregularities in the clearance between the mating surface and groove present areas where the seal can extrude. Gaskets by their design are laterally unrestrained seal systems and subject to creep.
SUMMARY OF THE INVENTION
The aforesaid problems of the prior art are overcome by the present invention which provides for a novel sealing element and its use to prevent the flow of fluid under high pressure differentials between the mating surfaces by providing a sealing element formed from a resilient polymeric material. The sealing element has a head with a cross section of generally semicircular circumference and a base to which the head is integrally connected. The base has integral wings extending outwardly in mutually opposite directions. The head of the sealing element is deformed by mechanical pressure applied against it by the mating element thereby increasing its contact surface area with the mating element for preventing passage of fluid between the sealing element and the mating surface. Pressure exerted by the fluid urges the deformed head against the wings for preventing passage of fluid between the sealing element and the carrier.
Fluid is prevented from traversing an interface between a surface of the carrier element and a surface of a the mating element by forming a concave groove in the carrier element, inserting within said groove, an elastomeric sealing element as described above, and placing the mating element surface in engagement with the carrier surface and with the convex outer surface of the head of the sealing element whereby said sealing element is deformed to assume a profile which presents an impenetrable barrier to the flow of fluid.
An object of the invention is to isolate or seal extensive irregular areas between two stationary mating surfaces as well as between symmetrical areas of mating surfaces.
Another object of the invention is to contain fluids, i.e., gas or liquids, within a vessel or conduit or exclude them from a vessel or conduit in the presence of a large pressure differential between the interior and exterior of the vessel or conduit.
Still another object of the invention is to effect a seal between surfaces having available areas which are very small.
DESCRIPTION OF THE DRAWINGS
FIG. 1 is a sectional elevation view of a sealing element with a carrier containing a polymeric component.
FIG. 2 is a sectional elevation view of a mating element having a mating surface intended to be engaged by the sealing element of FIG. 1 .
FIG. 3A illustrates a first step of a method of effecting a seal in accordance with the preferred embodiment of the invention;
FIG. 3B illustrates a second step of the method of effecting a seal in accordance with the preferred embodiment of the invention; and
FIG. 3C illustrates a third step of the method of effecting a seal in accordance with the preferred embodiment of the invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring now to FIGS. 1 and 2 of the drawings, the seal of the invention includes a closed loop sealing element 1 formed from an elastomeric polymer and having a uniform cross section throughout its length. Virtually any polymeric material resistant to compressive stress relaxation is suitable for use in the sealing element 1 .
The cross section of the sealing element 1 has a profile with a head 4 , which is generally semicircular in an unstressed condition, integral with a base 10 from which two integral wings 5 a and 5 b extend outwardly in mutually opposite directions.
Each of the wings has a profile narrower at a free end distal from the head 4 than at an opposite end proximate a juncture between the head 4 and the base 10 . The cross sectional profile of each wing initially widens with distance from the juncture between the head 4 and the base 10 toward an intermediate region of maximum thickness and then tapers inwardly, becoming progressively thinner with distance from the region of maximum thickness to its free edge.
A seal is effected when a seal carrier 3 , having a groove containing the sealing element 1 is urged against a surface 6 of a mating element.
The seal carrier 3 has a generally circular grove 8 , i.e., concave in cross section, with a radius more than twice the length of the radius of the semicircular head 4 of the sealing element 1 when in an unstressed condition. The base 10 of the profile is situated in and conforms to the groove 8 , the edges of the wings 5 a , 5 b being substantially flush with the edges of the groove 8 when the sealing element 1 is positioned within the groove 8 . When so positioned, approximately one-third of the height of the unstressed sealing element 1 , as measured from the lowest point 9 of the groove 8 to the apex 11 of the head 4 , protrudes above the seal carrier surface 13 outside of the groove 8 .
The tapered wings 5 a and 5 b protrude from the base 10 of the semi-circle at an oblique angle and conform to the concave groove 8 . The wings 5 a and 5 b initially widen with distance from the base 10 of the polymeric component's semi-circular profile until they are thickest, and then become progressively thinner until they terminate at the surface 13 of the carrier 3 .
The volume of the sealing element 1 is in the range of 90% to 100% of the volume of the groove 8 . When the seal is stressed during assembly of the mating element to the carrier, such that the mating surface 6 becomes flush with the grooved carrier surface 13 , the groove 8 will be more than 90 percent filled by the deflected sealing element 1 .
Referring now to FIGS. 3A, 3 B and 3 C of the drawings, the application of the seal will now be described.
As shown in FIG. 3A, a seal carrier 3 is placed in proximity to a mating element 12 with the sealing element 1 opposite the region of the mating surface 6 at which the seal is intended to be effected. The carrier 3 is then moved toward the mating surface 6 thereby stressing and deforming the sealing element 1 as shown in FIG. 3B from its unstressed semicircular profile. As pressure P is applied between the juxtaposed carrier and mating surfaces, the seal is “loaded” and the profile of the sealing element 1 is shifted to the eccentric position shown in FIG. 3 C.
EXAMPLE 1
A seal employing a sealing element 1 having a semicircular head 4 with a radius of 0.025 inches was placed with the convex surface of the head 4 lightly engaging a mating surface 6 on a mating element 12 . The initial contact surface area between the sealing element 1 and mating surface 6 was then measured. The carrier surface 13 was then placed against the mating surface 6 by applying minimum external force to the seal carrier 3 , thereby deforming the sealing element 1 . The effective contact area of the sealing element 1 was observed to increase by a factor of eighteen upon deformation. The resulting seal was able to withstand pressures in excess of 1000 psi once the seal was loaded.
The seal of the invention requires simple manufacturing steps. There are two essential components that must be fabricated: 1) a carrier 3 for the seal, and 2) a sealing element 1 that acts as the seal. Manufacture of the seal carrier 3 requires that a uniform concave depression be made in which the sealing element 1 will rest. The carrier 3 can either be molded, stamped, or cut from any type of metal or other rigid material.
Manufacture of the polymeric seal requires that a suitable polymeric mixture be molded in steel tooling that will provide the desired seal component dimensions. The polymeric mixture must embody a chemical system that enables molecular cross-linking to impart physical properties that will resist compressive stress relaxation.
The polymeric seal may either rest in the seal carrier groove 8 or be fixed in the groove 8 with an adhesive system. It is necessary that the wing tips 5 a and 5 b of the sealing element 1 remain situated within the groove 8 when the seal of the invention is assembled into the application.
Applying a minimum mechanical load to the sealing element 1 activates the seal of the invention. Several PSI of load force are adequate to establish a seal capable of withstanding pressure differentials magnitudes greater.
The seal of the invention utilizes a polymeric material to effect the seal. Effective contact between the two surfaces is necessary to form a seal. Surface finish on the mating surfaces and the clearance between the mating surfaces requires an elastomeric material capable of deforming and recovering its initial form to maintain effective contact between the two surfaces.
Seal contact area and the resulting seal surface stress (“contact stress”) from deflecting or mechanically loading the seal will determine the seal's efficacy. Normally, increasing either contact area or contact stress will increase sealing efficacy. However, constraints upon surface area or constraints upon design profiles, that could otherwise increase contact stress, have presented a problem. The seal of the invention is able to minimize contact area and maximize contact stress with a design profile that overcomes the usual constraints of design profiles known to the art. Rather than an O-ring profile (i.e. circular-section), the seal of the invention employs a semi-circular profile designed to deflect similarly to an O-ring when mechanically loaded. The seal's profile has a small radius that is impractical in an O-ring design. As the seal's profile collapses when mechanically loaded, both the contact area and contact stress increase thereby increasing the seal's efficacy. The result is an effective seal that occupies minimum surface area in the Application.
The seal of the invention requires at least 33% less sealing material than an O-ring to establish an equivalent seal. While an O-ring has a circular cross sectional profile, the profile of the seal of the invention is a small radius semi-circle. This geometry allows the seal of the invention to use less material than O-rings while having an equal or greater capacity to seal.
The seal of the invention is able to develop maximum contact stress in a manner consistent with a lip seal but using a profile that is resistant to damage, easily manufactured, and easily installed in the Application.
As in the case of a lip seal, the seal of the invention forms a “flap” as its profile collapses upon itself when subjected to minimal mechanical loading. In the Application, fluid pressure exerts a force upon this “flap” thereby increasing the seal's contact stress upon the sealing surface and improving the seal's efficacy. Unlike a lip seal with its flaps and necessary profile undercuts, the seal of the invention possesses a simple convex profile that is more resistant to damage and easily manufactured. Furthermore, unlike a lip seal, the seal of the invention is capable of sealing in either direction.
The seal of the invention is resistant to damage caused by excessive mechanical loading to which a gasket, common in the prior art, is susceptible. The seal of the invention is likewise resistant to the extrusion that a gasket experiences when a pressure differential exists across it. Since the seal of the invention utilizes a concave groove in which the polymeric seal material resides, the invention's sealing profile can be collapsed until the mating surface and seal carrier contact one another thereby limiting any additional mechanical stress.
As the seal's profile collapses upon itself during mechanical loading, a rubber wing of the profile, in conjunction with the carrier's concave groove, acts as a built in back-up washer to eliminate any tendency of the seal to extrude. Since the groove clearance becomes progressively smaller towards the edge of the groove, the seal's resistance to extrusion increases as the applied pressure increases. Furthermore, since the groove possesses a concave profile, there is no sharp groove angle, otherwise common in the art, which can present a fracture site as the seal attempts to extrude.
It is to be appreciated that the foregoing is a description of a preferred embodiment of the invention to which variations and modifications may be made without departing from the spirit and scope of the invention.
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A seal for preventing the flow of fluid under high pressure, between a carrier and a mating element adapted to engage the carrier is provided by a resilient elastomeric sealing element which is disposed in an arcuate groove in the carrier and deformed when the carrier is joined to the mating element. The sealing element has a base with oppositely extending wings and a head with a convex surface that is engaged by the mating element for deflecting the head within the groove.
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BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to methods of switching profiles in mobile devices, and more particularly, to a method of switching a profile in a mobile device based on time, date, location, or environmental factors.
[0003] 2. Description of the Prior Art
[0004] Mobile devices, such as mobile phones, PDAs, and smartphones, offer great convenience to users by allowing users to access communications and organization functions at any time and any place. In addition, most mobile devices are designed small enough to be carried in a pocket or clipped to a belt.
[0005] For this reason, mobile devices often accompany their users at all times. Most mobile devices include speakers for notifying users of incoming calls, scheduled events, and low battery charge. Unfortunately, if any of these notifications goes off while the user is at work, in a meeting, or at an important event, such as a wedding, disruption of the event, and consequent embarrassment of the user, ensues.
[0006] A number of options are available for the user to prevent such disruptions, including turning off the mobile device, muting the mobile device, activating a vibration feature, or some combination of these options. For example, the user may choose to mute all battery status notifications, but vibrate on incoming calls. Most mobile devices now include customizable “profiles,” which are used to define how the mobile device handles each type of notification event. Please refer to FIG. 1 , which is a diagram of profile options of various profiles for the mobile device. Depending on the environment the user is in, the user can select an appropriate profile, which includes settings such as volume, silent mode, vibration, and answering mode. If the user is in a meeting, the volume is turned off, silent mode is on, and vibration is on as long as silent mode remains on. If the user is in the car, then the volume is on, vibration is off, and the user can answer incoming calls with any key. The user can also customize each profile to suit their environment, or create new profiles.
[0007] While the creation, customization, and selection of the appropriate profile for each environment is a large step in the right direction, the user is very likely to forget to switch profiles when they change environments. So, the user may continue to use the meeting profile when they are driving, such that they miss calls, or have to look for the answer call key while driving, which is dangerous. Or, the user may forget to switch profiles before a meeting, and the mobile device may ring or make noises during the meeting, defeating the purpose of having the profiles in the first place.
SUMMARY OF THE INVENTION
[0008] According to the present invention, a method of switching a profile in a mobile device comprises the mobile device capturing an input when the mobile device detects a predetermined condition, and the mobile device switching the profile according to the input.
[0009] According to a second embodiment of the present invention, a method of switching a profile in a mobile device comprises the mobile device capturing an input when the mobile device detects a motion of the mobile device, and the mobile device selectively switching the profile according to the input.
[0010] These and other objectives of the present invention will no doubt become obvious to those of ordinary skill in the art after reading the following detailed description of the preferred embodiment that is illustrated in the various figures and drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0011] FIG. 1 is a diagram of profile options for a mobile device according to the prior art.
[0012] FIG. 2 is a diagram of switching a profile in a mobile device according to an embodiment of the present invention.
[0013] FIG. 3 is a diagram of a mobile device with a switchable profile according to an embodiment of the present invention.
DETAILED DESCRIPTION
[0014] Please refer to FIG. 2 , which is a flowchart of a method used for switching a profile in a mobile device according to the present invention. The method begins with detecting motion on a device, such as the mobile device mentioned above (Step 200 ). When motion is detected, the device may proceed to perform a number of steps to obtain information about its current environment. The device can record sounds through a microphone (Step 202 ), capture images of the environment through a camera (Step 204 ), obtain current time and date information (Step 206 ), or even obtain location information, e.g. through a GPS receiver (Step 208 ). The device can perform any combination of the above steps (Steps 202 - 208 ) to obtain information about its current environment. Then, based on the information obtained, the device may compare the information with a statistical model to estimate the current environment (Step 210 ).
[0015] In Step 200 , the mobile device detects motion of the mobile device. The motion may be detected when the mobile device begins moving from a state of rest, or when the mobile device stops moving from a state of motion. Other more refined methods of motion detection could also be employed, which take into account degrees of acceleration, acceleration along particular axes, etc. Further, instead of triggering the following steps of the method (Steps 202 - 208 ) by detecting motion, the mobile device could use a timer to activate the following steps (Steps 202 - 208 ) periodically. Other simple triggers, involving low power consumption light, heat, or sound sensors could also be used to detect a change in the environment. The mobile device may also utilize changes in the time to determine when to activate a profile change. For example, if the mobile device has been stationary for a long period of time after work, the profile may be changed from a home profile to a sleep profile. The following steps (Steps 202 - 210 ) may also be activated through a button press, such as an “auto-profile” button, which the user may press to tell the mobile device to determine on its own which profile to set depending on the current environment.
[0016] After the mobile device obtains some combination of audio, image, time/date, and location data from Steps 202 - 208 , the mobile device may compare the data obtained with the statistical model (Step 210 ). For example, amplitude of the audio data obtained in Step 202 may be used to determine if the user is outdoors or in a building. Certain types of sounds, such as car engines and honking noises may indicate that the user is outdoors. On the other hand, a low volume level, or a low instance of human voices, may indicate that the user is in a meeting, in the office, or at a theater. The image data obtained in Step 204 may have fluorescent lighting, which may indicate an indoor location, or natural lighting that may indicate an outdoor location. Low lighting may indicate a concert hall or movie theater. The image data and audio data may also include video data, which may include flicker of light sources or other recognizable characteristics. Using the current time and date data obtained in Step 206 , the mobile device may determine that the user is at work, in the car, or at home. If the current date falls on a weekend, then the user may not be at work. In conjunction with a calendar/scheduler application, the mobile device may determine that the user is in a meeting, at lunch with a client, or at a theatrical performance from events programmed into the scheduler. Finally, if the mobile device has a GPS unit, the location data obtained in Step 208 may be used to determine that the user is at their desk, in a conference room, in the car, at the theater, in church, or at any number of locations that are recognized by the GPS unit.
[0017] Based on the comparison with the statistical model, the mobile device then approximates the current environment in Step 210 , and selects a corresponding new profile that is appropriate for the environment the mobile device is in (Step 212 ). If the mobile device is in the office, the mobile device may select the office profile. If the mobile device is in a meeting, then it may select the meeting profile. As the mobile device may be making an approximation or estimate of where it is located, such that the location may be uncertain, the mobile device may further inform the user that it is changing to the new profile (Step 214 ). If the user approves of the profile change (Step 216 ), the mobile device applies the new profile (Step 220 ), and the behavioral model is updated (or learns) for future profile estimations (Step 222 ). On the other hand, if the user does not approve of the profile change, the user may manually select an appropriate new profile they feel fits the current environment, or simply keep the previous profile, and the mobile device may then set the new profile, or do nothing, and update the behavioral model accordingly.
[0018] Please refer to FIG. 3 , which is a diagram of a mobile device 30 with a switchable profile according to an embodiment of the present invention. The mobile device 30 may comprise a control circuit 300 , and a plurality of output and input devices 301 - 308 . Based on input from the plurality of input devices 301 - 304 , the control circuit 300 may select a profile 352 for controlling the plurality of output devices 305 - 308 . As shown, the control circuit 300 may comprise a processor 310 , a detection unit 320 , an input I/O 330 , an output I/O 340 , and memory 350 . The detection unit 320 may receive and process signals from a microphone 301 , a camera 302 , a temperature sensor 303 , and/or a motion sensor 304 , etc., through the input I/O 330 . Types of detection may include those described in Steps 200 to 208 shown in FIG. 2 . Then, based on behavior models 351 stored in the memory 350 , the detection unit 320 may generate a detection result that may be passed to the processor 310 . The processor 310 may then select an appropriate profile 352 from the memory 350 based on the detection result. The profile 352 may correspond to the profiles shown in FIG. 1 , and may be utilized by the processor 310 for modifying behavior of a ringer 305 , a display 306 , a vibration module 307 , and/or a power management module 308 , etc. For example, based on the profile 352 , the processor 310 may set a ring volume of the ringer 305 higher or lower, turn vibration of the vibration module 307 on or off, increase or lower backlight intensity of the display 306 , or activate a power-saving mode of the power management module 308 . The processor 310 may also be utilized to update the behavior model 351 .
[0019] Compared to the prior art, which leaves responsibility for making appropriate profile changes up to the user, the present invention enables the mobile device to determine the appropriate profile automatically, which is a great convenience to the user, and reduces the likelihood of missing a call or interrupting an important event.
[0020] Those skilled in the art will readily observe that numerous modifications and alterations of the device and method may be made while retaining the teachings of the invention.
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To switch a profile in a mobile device, the mobile device captures an input when the mobile device detects a predetermined condition, and the mobile device switches the profile according to the input. The predetermined condition could include detection of motion or rest, or recurring update periods. Examples of inputs captured include digital images, sounds, videos, location, and time.
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This is a continuation-in-part of application Ser. No. 435,029 filed Oct. 18, 1982, now abandoned.
TECHNICAL FIELD
This invention relates to a method of introducing fluorine into glasses. In one of its more specific aspects, this invention relates to a method in which a high fluorine glass, called a fluorine frit, is employed as the major fluorine source in a glass batch to increase fluorine retention in the final glass.
BACKGROUND OF THE INVENTION
The use of molten glass for the production of glass fibers is wellknown. Glasses used for this purpose contain a multiplicity of chemical elements. Among these is fluorine which is usually introduced into a glass batch as calcium fluoride (fluoro spar) or sodium fluosilicate (sodium silicofluoride). The presence of fluorine in the glass is important because fluorine acts as a melting aid, facilitates fining, and reduces flooding tendencies of the bushing from which glass fibers are drawn.
In calculating the quantity of the fluorine source required to impart the desired fluorine content to the final glass, it is necessary to allow for fluorine losses during the melting process. These losses are in the range of from about 30 to 80 percent of the fluorine added. The fluorine is evolved as silicon tetrafluoride (SiF 4 ), hydrogen fluoride (HF) and other fluorides such as boron trifluoride (BF 3 ) and boron oxyfluoride (BOF), depending upon the glass composition. The amount of the fluorine losses depends upon a variety of factors. These fluorine losses result in potential pollution problems.
The method of this invention is directed towards solving this problem.
U.S. Pat. No. 3,331,731 issued to Baak teaches a method of introducing fluorine into glasses which minimizes fluorine loss. Baak's method involves melting all the glass components except the fluorine source to a homogeneous glass, cooling and pulverizing the glass, mixing the pulverized glass with a powdered form of the fluorine source, and melting the mixture to prepare the final glass. Baak's method requires that in the order of 90 weight percent of the final glass batch components be pulverized and remelted to make the final glass.
The method of this invention is also directed at minimizing these costly pulverizing and remelting requirements.
STATEMENT OF THE INVENTION
According to this invention there is provided a method of increasing fluorine retention in a final glass and reducing fluoride emissions during the melting of glass batch. The method involves introducing fluorine into the glass batch in the form of a fluorine-containing frit and then melting the glass batch. The fluorine-containing frit comprises an inorganic fluoride and contains from about 6 to about 10 weight percent fluorine.
DESCRIPTION OF THE INVENTION
The method of this invention is applicable to increasing the fluorine content of any glass. It is particularly suitable for incorporating fluorine into E-type glasses.
The fluorine-containing frit, viz. an intermediate glass, will be added to the glass batch as particles in amounts necessary to supply from about 0.05 to about 2.00 weight percent fluorine in the glass batch.
The fluorine-containing frit can be clear or opaline and is preferably as small as the particles in the glass batch. The glass batch used to prepare the frit, and the frit itself can be of any suitable composition and, preferably, the frit will be prepared by melting silicon dioxide, aluminum oxide, calcium fluoride and calcium carbonate in amounts necessary to form a fluorine-containing frit containing between about 6 and about 10 weight percent fluorine.
The following examples demonstrate the method of this invention.
EXAMPLE I
The glass batch used to prepare a fluorine-containing frit (F1), comprised the following components:
______________________________________Component Weight Percent______________________________________SiO.sub.2 54.87Al.sub.2 O.sub.3 13.72CaF.sub.2 31.41Total 100.00______________________________________
The oxide composition of the batch for fluorine-containing frit (F1) was:
______________________________________Component Weight Percent______________________________________SiO.sub.2 51.56Al.sub.2 O.sub.3 12.89CaO 21.19F.sub.2 14.36Total 100.00______________________________________
The analyzed composition of the fluorine-containing frit (F1) prepared from this batch was:
______________________________________Component Weight Percent______________________________________SiO.sub.2 52.24Al.sub.2 O.sub.3 14.42CaO 23.59F.sub.2 9.74Total 99.99______________________________________
The fluorine-containing frit (F1) was then pulverized and added to glass batches having the following analyses:
______________________________________ Weight PercentsComponent Batch A Batch B Batch C Batch D______________________________________SiO.sub.2 43.41 41.39 47.29 42.60Al.sub.2 O.sub.3 11.39 10.84 11.94 10.89CaCO.sub.3 31.10 29.49 32.31 29.21H.sub.3 BO.sub.3 9.25 9.31 -- --Na.sub.2 CO.sub.3 0.81 0.82 -- --Frit (F1) 4.03 8.15 8.46 17.29Total 99.99 100.00 100.00 99.99______________________________________
In terms of oxide weight percents, these batches were as follows:
______________________________________ Weight PercentsComponent Batch A Batch B Batch C Batch D______________________________________SiO.sub.2 55.56 55.28 60.28 59.28Al.sub.2 O.sub.3 14.60 14.53 15.32 15.32CaO 22.41 22.30 23.40 23.40B.sub.2 O.sub.3 6.34 6.31 -- --Na.sub.2 O 0.58 0.58 -- --F.sub.2 0.50 1.00 1.00 2.00Total 99.99 100.00 100.00 100.00______________________________________
These final glass batches were melted at 2850° F. for three hours, cooled, and then the fluorine retention for each of the final glasses was determined. The results were as follows:
______________________________________Final Glass Fluorine RetentionPrepared From Wt. % F.sub.2 In Final Batch______________________________________Batch A 104 ± 6Batch B 95 ± 5Batch C 112 ± 5Batch D 118 ± 6______________________________________
Analysis of this data shows that, using the method of this invention, it was possible to prepare glasses in which from about 95 to about 100 weight percent of the fluorine in the final glass batches was retained in the glass.
EXAMPLE II
The glass batch used to prepare a fluorine-containing frit (F2) comprised the following components:
______________________________________Component Weight Percent______________________________________SiO.sub.2 53.44Al.sub.2 O.sub.3 13.36CaCO.sub.3 21.76CaF.sub.2 11.44Total 100.00______________________________________
The oxide composition of the batch for the fluorine-containing frit (F2) was:
______________________________________Component Weight Percent______________________________________SiO.sub.2 57.60Al.sub.2 O.sub.3 14.40CaO 22.00F.sub.2 6.00Total 100.00______________________________________
The analyzed composition of the fluorine-containing frit (F2) prepared from this batch was:
______________________________________Component Weight Percent______________________________________SiO.sub.2 57.17Al.sub.2 O.sub.3 14.54CaO 22.20F.sub.2 6.09Total 100.00______________________________________
The fluorine-containing frit (F2) was then pulverized and added to glass batches having the following analyses:
______________________________________ Weight PercentsComponent Batch E Batch F Batch G Batch H______________________________________SiO.sub.2 41.92 38.36 44.17 36.15Al.sub.2 O.sub.3 11.05 10.15 11.23 9.41CaCO.sub.3 30.29 27.83 30.60 25.66H.sub.3 BO.sub.3 9.28 9.36 -- --Na.sub.2 CO.sub.3 0.81 0.82 -- --Frit (F2) 6.65 13.48 14.00 28.79Total 100.00 100.00 100.00 100.01______________________________________
In terms of oxide weight percents, these batches were as follows:
______________________________________ Weight PercentsComponent Batch E Batch F Batch G Batch H______________________________________SiO.sub.2 55.56 55.28 60.28 59.28Al.sub.2 O.sub.3 14.60 14.53 15.32 15.32CaO 22.41 22.30 23.40 23.40B.sub.2 O.sub.3 6.34 6.31 -- --Na.sub.2 O 0.58 0.58 -- --F.sub.2 0.50 1.00 1.00 2.00Total 99.99 100.00 100.00 100.00______________________________________
These final glass batches were melted at 2850° F. for three hours, cooled, and then the fluorine retention for each of the final glasses was determined. The results were as follows:
______________________________________Final Glass Fluorine Retention, Wt. %Prepared From F.sub.2 In Final Batch______________________________________Batch E 76 ± 6Batch F 94 ± 5Batch G 93 ± 5Batch H 101 ± 6______________________________________
Analysis of this data shows that, using the method of this invention, it was possible to prepare glasses in which from about 76 to about 100 weight percent of the fluorine in the final glass batches was retained in the glasses.
EXAMPLE III
A glass batch was prepared wherein calcium fluoride was used as the fluorine source. The composition of this batch was:
______________________________________Component Weight Percent______________________________________SiO.sub.2 45.95Al.sub.2 O.sub.3 11.66CaCO.sub.3 30.27H.sub.3 BO.sub.3 7.38Na.sub.2 CO.sub.3 1.42CaF.sub.2 1.71Other 1.61Total 100.00______________________________________
The oxide composition of this glass batch was:
______________________________________Component Weight Percent______________________________________SiO.sub.2 55.3Al.sub.2 O.sub.3 14.0CaO 22.0B.sub.2 O.sub.3 5.0Na.sub.2 O 1.0F.sub.2 1.0Other 1.7Total 100.00______________________________________
After melting the above glass batch for three hours at 2850° F. and cooling, there was about 62 weight percent of the original glass batch fluorine in the final glass.
The three examples shown above indicate that while all the final glass batches had fluorine contents within the range of from about 0.5 to about 2.0 weight percent, the final glasses of Examples I and II, which were prepared using the method of this invention, had a much higher fluorine retention (between about 76 and about 100 weight percent) than did the final glass of Example III (about 62 weight percent), which was prepared by adding calcium fluoride to the batch, a method old in the art.
Analysis of the data from Examples I and II shows that using the method of this invention requires that only about 4 to about 29 weight percent of the final glass batch components, specifically the frit, be crushed or pulverized, and remelted, to make the final glass. This result distinguishes this invention over Baak, because Baak's method requires that in the order of 90 weight percent of the final glass batch components be pulverized and remelted to make the final glass. Additionally, in a glass production plant, the melting capacity required to produce the fluorine-containing frit of this invention is only about 4 to about 29 percent of the melting capacity required to produce the final glass. Since the major portion of the fluorine losses occur in frit production, it is apparent that when using the method of this invention, fluorine emission control means will be potentially required on a fewer number of melters compared to production of fluorine-containing final glasses without using fluorine-containing frit, as in the method taught by Baak.
It will be evident from the foregoing that various modifications can be made to this invention. Such, however, are within the scope of the invention.
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A method of introducing fluorine into glasses characterized by high fluorine retention and low processing costs which involves introducing the fluorine into the glass batch as a fluorine-containing frit comprising an inorganic fluoride and containing from about 6 to about 10 weight percent fluorine.
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CROSS REFERENCE TO RELATE APPLICATION
[0001] Provisional patent application #61353900 filed 10 Jun. 2010, titled Multi-purpose sponge applicator with universal grip
BACKGROUND
[0002] This invention relates to an apparatus for holding a tool, equipment or instrument during operation of said device. The term “universal” implies that various disabilities of the hand/fingers have been considered in the design of the grip. The term “multipurpose” implies that the grip itself may be manufactured as an accessory or attached to or part of a shaft, wheel, handle, surface, etc.
[0003] Various grips may be known. However, the distinguishing features of the multipurpose universal grip make it usable by persons with a thumb and one or more fingers on a hand, with deformed fingers, or with normal fingers. The present invention may accommodate one or two hands.
SUMMARY OF THE INVENTION
[0004] The present invention is directed to holding a tool, surface or instrument and may be attached to or part of a shaft, wheel, surface or handle. The grip may be two-handed, ambidextrous or right- or left-handed. The top and bottom surfaces of the grip may be flat, textured, circular or elliptical. The top and bottom surfaces may be identical.
[0005] An indentation on the top surface may serve as an anchor point for the thumb. This indentation may run the entire length of the grip to accommodate two hands. The indentation may be shaped to accommodate one or two thumbs. An indentation may be on the bottom surface to serve as an anchor point for the thumb.
[0006] There are sloped indentations for the tips of the fingers on the sides of the grip. These indentations direct the finger tips away from the top surface of the device. There may be ridges between the indentations on the sides of the device. Indentations and ridges do not encompass the circumference of the device.
[0007] These and other features, aspects and advantages of the present invention will become better understood with reference to the following drawings, description and claims.
BRIEF DESCRIPTION OF THE DRAWINGS
[0008] FIG. 1 The top view of the grip
[0009] FIG. 2 Artist's Rendering of the Invention when used as an applicator
[0010] FIG. 3 is a top plan view of the grip and handle of a 15″ sponge applicator embodiment.
[0011] FIG. 4 is a side view of the grip and handle of a 15″ sponge applicator embodiment.
[0012] FIG. 5 is a side view of the grip and handle of a 15″ sponge applicator embodiment.
[0013] FIG. 6 is a sponge 3×3×½ to be attached to a 15″ sponge applicator embodiment
DETAILED DESCRIPTION OF THE INVENTION
[0014] The multipurpose universal grip may be designed to be held by a thumb and one finger, by any mechanical device that substitutes for a thumb and one finger, or by any other method that allows the user to simultaneously grasp two opposite surfaces without bending the wrist. When holding the invention with a normal hand, a straight line can be drawn from the elbow to the tip of the thumb. The invention may be attached to a rigid shaft, wheel, surface or handle. In one version, the invention has no movable parts and no mechanical fasteners. The invention may be solid or hollow and may or may not have a reservoir for liquids. In addition, the bottom portion of the invention closest to the user may have a spiral, contoured shape. The invention has sloped indentations for fingers on the sides and flat, textured, circular or elliptical surfaces on the top and bottom faces. See FIG. 1 . The invention is in one version “disposable”. In addition, the exterior surface of the invention may have a textured surface as shown in FIG. 2 .
[0015] The invention may be made of formed plastic, metal or other rigid or semi-rigid material. The invention may be ambidextrous. The top and bottom may be identical. The spiral, contours on the sides of the invention may facilitate its grasp by an individual with a thumb and one or more fingers, with deformed fingers, or with normal fingers. The grip may be modified to accommodate one or two hands. This ergonomic device may be held equally well in either the left or right hand without bending the wrist.
[0016] In one embodiment, shown in FIGS. 2-5 , the invention is attached to a handle that connects to a sponge. One purpose of the embodiment is to extend the reach of the user for the purpose of applying liquids, including lotions and/or medications to body surfaces such as the back or to apply liquids such as paint or tar to building surfaces or to apply cleaning agents to other types of surfaces. Individuals of all ages may have limited ability to reach certain body parts in particular the back for the application of lotions and topical medicines. In addition a person may wish to spread a liquid on a surface which is otherwise unreachable. See FIGS. 3-5 for the 15″ variant used to apply acne medicine to the back. This version can be sized to fit inside a woman's purse, a beach bag or a gym bag. The entire assemble can be washed. In one version, the sponge cannot be detached from the handle. The sponge may be made from material that does not absorb lotion/medication. For example, the sponge material to be used with sunscreen should be lipophobic. The sponge material to be used with acne medications should be hydrophobic. The sponge may be re-usable and washable or disposable. The sponge on the 15″ variant is approximately the size and shape of the palm of an adult human hand as shown in FIG. 6 .
[0017] Versions describe herein an ergonomically friendly applicator for applying liquids. The sponge and the handle above the invention may be symmetric about the longitudinal axis. The invention is designed so that either the left or right hand can be used. The invention may be modified to accommodate two-handed use, for example, as the grip on a golf club. The overall size of the device and the material choice for the invention may vary depending on the. application. For example a length up to 60″ may be suitable for cleaning or maintenance tasks while the 15″ embodiment may be used to apply lotions/medicines to the mid-back. These examples are not intended to limit the application of the invention.
[0018] The invention may be incorporated with other gadgets including but not limited to kitchen tools such as knives and spatulas; work tools such as screwdrivers and flashlights; recreational items such as golf clubs and pogo sticks; weapons and steering mechanisms. All dimensions shown in FIGS. 1-6 may change, to accommodate the application.
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The Multi-purpose Universal Grip is an ergonomically designed grip for use by persons with a thumb and one or more fingers. The grip itself may be manufactured as an accessory or attached to or part of a shaft, wheel, handle, surface, etc.
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DESCRIPTION
[0001] This application claims priority of my prior, co-pending provisional patent application, Serial 60/302,165, filed on Jun. 28, 2001, entitled “ERGONOMIC HIGH VOLUME EVACUATOR HANDLE,” which is incorporated herein by reference.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] This invention relates to the physical health of dental health professionals. More specifically, this invention is an ergonomic grip design for a high volume evacuator that may reduce the risk of fatigue related conditions, such as carpal tunnel syndrome, that is associated with long-duration chair-side assistance.
[0004] 2. Related Art
[0005] Painful medical conditions caused by fatigue may result in a significant loss of productivity within the workplace or prematurely end the careers of employees. One common fatigue related injury among dental assistants, specific to the hand and wrist, is carpal tunnel syndrome. Complications such as carpal tunnel syndrome may be the result of repeated or prolonged exposure to stressful postures or actions. If the body and its sections are positioned correctly, from a biomechanical perspective, these complications may be avoided.
[0006] In the past, few attempts have been made to improve the apparatus used daily by dental assistants, specifically the high volume evacuator (HVE). One existing design involves an alteration to the straight-line suction path used presently. In this design the handle forms a near right angle with the disposable suction tip and the valve is operated with the thumb rather than the small and ring fingers. Another current product consists of a short slide-on grip composed of latex-free silicone rubber and is shaped similarly to a golf club grip, simply thicker in the middle than on the ends. Still, there is a need for an ergonomically designed HVE handle that can be simply and inexpensively integrated into common practice.
SUMMARY OF THE INVENTION
[0007] The invention comprises a modified handle for the high volume evacuator commonly used in dental offices. This handle more closely models the contour of the hand. The objective of this design is to reduce the incidence of carpal tunnel syndrome and other fatigue related conditions among dental health professionals. Use of the device may allow these professionals to provide chair side assistance for long periods of time without pain. Another objective of this invention is to make the integration of this technology into modem dental offices simple and inexpensive by conforming to existing design specifications as much as possible.
[0008] This device may consist of a few simple components. The internal aspect of the handle comprises a channel that provides the link between the patient and the evacuation source. This channel is typically comprised of a metal tube that is fitted with a rotating ball valve. The rearward portion of the metal tube, or pipe, includes a set of threads or ridges that allow the evacuator hose to be attached. At the front of this pipe, a disposable O-ring is attached internally. This O-ring ensures a tightly sealed connection between the handle and the removable suction tips that are used presently with high volume evacuators. The forward section of the handle includes a rotating-ball valve. This preferably consists of a sphere with a center bore that is attached to a plastic lever by a short metal stem. Movement of the lever rotates the ball within the tube to allow, or prevent, suction through the center-bore.
[0009] The metal interior of the handle is surrounded by a soft, autoclavable rubber grip. This grip produces the contoured shape of the invention and provides insulation from the metal parts. The rubber grip has a bulbous mid-section that is tapered towards both ends. The tapered forward section offers a suitable gripping surface for the pinkie finger, and the tapered rearward portion allows the thumb and forefinger to grip comfortably. The swollen middle section is designed to fit the palm of the hand or the insides of the thumb and fingers more naturally. After the taper at both ends of the bulbous mid-section are flared distal and proximal end sections. There flared ends provide rest/stop places for fingers or the thumb, depending on the manner in which the handle is held by the user. The rubber grip is removable for autoclavability, but can also be cleaned with disinfectant. A disposable plastic sleeve may be manufactured for sterility purposes.
BRIEF DESCRIPTION OF THE DRAWINGS
[0010] [0010]FIG. 1 is a side, schematic view of one embodiment of the ergonomic high volume evacuator handle of the present invention.
[0011] [0011]FIG. 2 is a side, schematic view of the internal components of the embodiment shown in FIG. 1, indicating the suction path and the direction of flow.
[0012] [0012]FIG. 3 is another side, schematic view of the embodiment of FIG. 1, showing some dimensions of the basic form of the grip.
[0013] [0013]FIG. 4 is a detail, schematic internal view of the valve used in the present invention.
[0014] [0014]FIG. 5 is a detail, schematic drawing of the rotating ball valve shown in FIG. 4.
[0015] [0015]FIG. 6 is a detail, schematic top view of the valve pictured in FIG. 4, showing the angles of rotation for the plastic lever required to open and close the valve.
[0016] [0016]FIG. 7 is an internal view of the valve, showing the placement of the O-ring that seals the connection between the handle and the disposable suction tip.
[0017] [0017]FIG. 8 is an illustration of one common grasp of the handle of the present invention used by dental assistants.
[0018] [0018]FIG. 9 is an illustration of another common grasp of the handle of the present invention used by dental assistants.
DETAILED DESCRIPTION OF THE INVENTION
[0019] Referring to the Figures, there are depicted several views of the invented ergonomic handle 100 for the high volume evacuator commonly used in dental offices. This device will preferably be used by professional dental assistants to provide a gripping surface that readily conforms to the contours of the hand. This will increase comfort and reduce the incidence of carpal tunnel syndrome and other fatigue related conditions.
[0020] The preferred embodiment of the ergonomic design for a high volume evacuator handle 100 is shown in FIGS. 1 and 2. The handle 100 comprises a soft shell or wrap which surrounds a metal tube 2 , or pipe, that is approximately ½ inch in diameter and preferably about 4 inches long. The metal tube 2 is fitted with a set of threads or ridges 3 at the rear (proximal) end and a valve 4 at the front (distal) end. The threads 3 are used to connect the metal tube 2 to the evacuator hose, which is not shown in the figures. The valve 4 shown in detail in FIG. 4 houses the rotating ball valve 10 that is shown in detail in FIG. 5, and provides the functional link between the metal tube 2 within handle 100 and the disposable suction tip 5 .
[0021] The rotating ball valve 10 comprises a metal sphere 12 with a center bore that attaches to a plastic lever 11 by a short metal stem 13 . The plastic lever forms a U-shape around the valve seat 4 , and is connected to the sphere 12 at the ends by two short connections 13 , as shown in FIG. 5. The plastic lever 11 rotates from approximately 45 degrees to 135 degrees with respect to the axis of the metal tube 2 as shown in FIG. 6. The lever is typically rotated in operation by using the small and ring fingers in a sweeping motion. The valve 10 is in the ‘on’ position when the plastic lever 11 is at an angle of 135 degrees. In this position, suction flows through the handle 1 in the direction indicated in FIGS. 1, 2, and 3 . At the distal end, the interior of the valve 4 contains a replaceable, rubber O-ring 14 as shown in FIG. 7. The O-ring 14 ensures the necessary seal between the metal tube 2 within handle 100 and the disposable suction tip 5 at the point of attachment, as shown in FIG. 7.
[0022] A soft, rubber grip 6 of handle 100 surrounds the metal tube 2 between the valve 4 and the set of threads or ridges 3 . The grip 6 comprises a bulbous mid-section 8 and tapered sections towards both the rear (proximal) end 7 and the front (distal) end 9 , as shown in FIG. 3. The grip design preferably includes flared ends to prevent slippage in the hand and create the useful recessed areas, tapered sections 7 and 9 . The grip is preferably about 3.5 inches in circumference at its widest point, typically the bulbous mid-section 8 and preferably about 2 inches in circumference at its narrowest point(s), typically the tapered sections 7 and 9 . The flared ends are typically more in circumference than the tapered sections, and less in circumference than the bulbous mid-section. These dimensions, and other preferred grip specifications are shown in FIGS. 1, 2 and 3 .
[0023] The rubber grip 6 is preferably a soft, removable wrap that can be fastened around the metal tube 2 by any one of a number of simple mechanisms. It may, however, alternatively comprise a flexible, hollow cylinder that may be slid off over the threads or ridges 3 or over the distal end after the valve 4 is removed. The grip 6 may be cleaned in place with disinfectant, but it may also be removed for autoclavability.
[0024] The ergonomic handle 100 provides a comfortable gripping surface for a variety of grasps, two of which are shown in FIGS. 8 and 9. Using the pencil grip of FIG. 8, the tapered section 7 nearest the threads or ridges 3 in connection with the flared proximal end allows the thumb and index finger to wrap comfortably around the handle 100 . The tapered section 9 nearest the valve 4 in conjunction with the flared distal end, provides a supportive groove for the thumb, index and middle distal phalanxes, or fingertips, as shown in FIG. 8. For this hold, the bulbous mid-section 8 matches the natural curvature of the thumb and index fingers to provide a comfortable and stable grasp.
[0025] Using the stab grip illustrated in FIG. 9, the ergonomic handle 1 utilizes contact with most all of the hand's interior surface to provide a firm, comfortable hold. The narrow proximal section 7 provides a comfortable gripping surface for the thumb and index finger. The distal grasp the handle powerfully with only the fingertips and prevents uncomfortable overlap between the fingers and the hand, as shown in FIG. 9.
[0026] Although this invention has been described above with reference to particular means, materials and embodiments, it is to be understood that the invention is not limited to these disclosed particulars, but extends instead to all equivalents within the scope of the following claims.
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Disclosed is an ergonomic handle for the high volume evacuator that is designed to reduce the incidence of fatigue-related medical conditions among dental assistants. The handle comprises a hollow tube composed of a rigid material that allows the suction to flow through the interior, a valve that allows the suction to be turned on and off, and a soft, non-latex rubber grip specifically shaped to match the natural curvature of the hand for a variety of grasps. The grip has a bulbous mid-section, and two recessed areas, one on each side of the bulbous mid-section. In addition, both the proximal and distal ends of the grip are flared. Preferably, the design will be compatible with existing technology to make its incorporation into modern dental offices simple and inexpensive. The device may maximize comfort and minimize the stresses encountered by dental assistants in a normal working day, specifically in the area of the hand.
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CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This Application is a Continuation of application Ser. No. 10/729,830 filed on Dec. 5, 2003, which is a continuation-in-part of PCT Application No. PCT/EP02/06180 filed Jun. 5, 2002, which in turn, claims priority from German Application 10127283.9, filed Jun. 5, 2001. Applicants claim benefit under 35 U.S.C. §120 as to the U.S. application and the PCT application and under 35 U.S.C. §119 to the German application, and the disclosures of all of said applications are incorporated herein by reference.
SUBMISSION OF SEQUENCE LISTING
[0002] The Sequence Listing associated with this application is filed in electronic format via EFS-Web and hereby incorporated by reference into the specification in its entirety. The name of the text file containing the Sequence Listing is Sequence_Listing — 22122 — 00009_CON2. The size of the text file is 19 KB, and the text file was created on May 19, 2010.
BACKGROUND OF THE INVENTION
[0003] 1. Field of the Invention
[0004] The present invention relates to a pharmaceutical composition containing an mRNA that is stabilised by sequence modifications in the translated region and is optimised for translation. The pharmaceutical composition according to the invention is suitable in particular as an inoculating agent and also as a therapeutic agent for tissue regeneration. Furthermore a process for determining sequence modifications that stabilise and optimise mRNA translation is disclosed.
[0005] 2. Description of the Prior Art
[0006] Gene therapy and genetic vaccination are tools of molecular medicine whose use in the treatment and prevention of diseases has considerable potential. Both of these approaches are based on the incorporation of nucleic acids into a patient's cells or tissue as well as on the subsequent processing of the information coded by the incorporated nucleic acids, i.e. the expression of the desired polypeptides.
[0007] The conventional procedure involved in previous processes of gene therapy and genetic vaccination is the use of DNA in order to incorporate the required genetic information into the cell. In this connection various processes for the incorporation of DNA into cells have been developed, such as for example calcium phosphate transfection, polyprene transfection, protoplast fusion, electroporation, microinjection and lipofection, in which connection lipofection in particular has proved to be a suitable process.
[0008] A further process that has been suggested in particular in the case of genetic vaccination involves the use of DNA viruses as DNA vehicles. Because such viruses are infectious, a very high transfection rate can be achieved when using DNA viruses as vehicles. The viruses used are genetically altered so that no functional infectious particles are formed in the transfected cell. Despite this precautionary measure, however the risk of uncontrolled propagation of the introduced therapeutic gene as well as viral genes remains due to the possibility of recombination events.
[0009] Normally DNA incorporated into a cell is integrated to a certain extent into the genome of the transfected cell. On the one hand this phenomenon can exert a desirable effect, since in this way a long-lasting action of the introduced DNA can be achieved. On the other hand the integration into the genome brings with it a significant risk for gene therapy. Such integration events may, for example, involve an insertion of the incorporated DNA into an intact gene, which produces a mutation that interferes with or completely ablates the function of the endogenous gene. As a result of such integration events, enzyme systems that are important for cellular viability may be switched off. Alternatively, there is also the risk of inducing transformation of the transfected cell if the integration site occurs in a gene that is critical for regulating cell growth. Accordingly, when using DNA viruses as therapeutic agents and vaccines, a carcinogenic risk cannot be excluded. In this connection it should also be borne in mind that, in order to achieve effective expression of the genes incorporated into the cell, the corresponding DNA vehicles contain a strong promoter, for example the viral CMV promoter. The integration of such promoters into the genome of the treated cell may, however, lead to undesirable changes in the regulation of the gene expression in the cell.
[0010] A further disadvantage of the use of DNA as a therapeutic agent or vaccine is the induction of pathogenic anti-DNA antibodies in the patient, resulting in a potentially fatal immune response.
[0011] In contrast to DNA, the use of RNA as a therapeutic agent or vaccine is regarded as significantly safer. In particular, use of RNA is not associated with a risk of stable integration into the genome of the transfected cell. In addition, no viral sequences such as promoters are necessary for effective transcription of RNA. Beyond this, RNA is degraded rapidly in vivo. Indeed, the relatively short half-life of RNA in circulating blood, as compared to that of DNA, reduces the risks associating with developing pathogenic anti-RNA antibodies. Indeed, anti-RNA antibodies have not been detected to date. For these reasons RNA may be regarded as the molecule of choice for molecular medicine therapeutic applications.
[0012] However, some basic problems still have to be solved before medical applications based on RNA expression systems can be widely employed. One of the problems in the use of RNA is the reliable, cell-specific and tissue-specific efficient transfer of the nucleic acid. Since RNA is normally found to be very unstable in solution, up to now RNA could not be used or used only very inefficiently as a therapeutic agent or inoculating agent in the conventional applications designed for DNA use.
[0013] Enzymes that break down RNA, so-called RNases (ribonucleases), are responsible in part for the instability. Even minute contamination by ribonucleases is sufficient to degrade down RNA completely in solution. Moreover, the natural decomposition of mRNA in the cytoplasm of cells is exquisitely regulated. Several mechanisms are known which contribute to this regulation. The terminal structure of a functional mRNA, for example, is of decisive importance. The so-called “cap structure” (a modified guanosine nucleotide) is located at the 5′ end and a sequence of up to 200 adenosine nucleotides (the so-called poly-A tail) is located at the 3′ end. The RNA is recognised as mRNA by virtue of these structures and these structures contribute to the regulatory machinery controlling mRNA regulation. In addition there are further mechanisms that stabilise or destabilise RNA. Many of these mechanisms are still unknown, although often an interaction between the RNA and proteins appears to be important in this regard. For example, an mRNA surveillance system has been described (Hellerin and Parker, Annu. Rev. Genet. 1999, 33: 229 to 260), in which incomplete or nonsense mRNA is recognised by specific feedback protein interactions in the cytosol and is made accessible to decomposition. Exonucleases appear to contribute in large measure to this process.
[0014] Certain measures have been proposed in the prior art in order to improve the stability of RNA and thereby enable its use as a therapeutic agent or RNA vaccine.
[0015] In EP-A-1083232 a process for the incorporation of RNA, in particular mRNA, into cells and organisms has been proposed in order to solve the aforementioned problem of the instability of RNA ex vivo. As described therein, the RNA is present in the form of a complex with a cationic peptide or protein.
[0016] WO 99/14346 describes further processes for stabilising mRNA. In particular modifications of the mRNA are proposed that stabilise the mRNA species against decomposition by RNases. Such modifications may involve stabilisation by sequence modifications, in particular reduction of the C content and/or U content by base elimination or base substitution. Alternatively, chemical modifications may be used, in particular the use of nucleotide analogues, as well as 5′ and 3′ blocking groups, an increased length of the poly-A tail as well as the complexing of the mRNA with stabilising agents, and combinations of the aforementioned measures.
[0017] In U.S. Pat. No. 5,580,859 and U.S. Pat. No. 6,214,804 mRNA vaccines and mRNA therapeutic agents are disclosed inter alia within the scope of “transient gene therapy” (TGT). Various measures are described therein for enhancing the translation efficiency and mRNA stability that relate in particular to the composition of the non-translated sequence regions.
[0018] Bieler and Wagner (in: Schleef (Ed.), Plasmids for Therapy and Vaccination, Chapter 9, pp. 147 to 168, Wiley-VCH, Weinheim, 2001) report on the use of synthetic genes in combination with gene therapy methods employing DNA vaccines and lentiviral vectors. The construction of a synthetic gag-gene derived from HIV-1 is described, in which the codons have been modified with respect to the wild type sequence (alternative codon usage) in such a way as to correspond to frequently used codons found in highly expressed mammalian genes. In this way, in particular, the A/T content compared to the wild type sequence was reduced. Moreover, the authors found an increased rate of expression of the synthetic gag gene in transfected cells. Furthermore, increased antibody formation against the gag protein was observed in mice immunised with the synthetic DNA construct. An increase in cytokine release in vitro in the case of transfected spleen cells of such mice was also observed. Finally, an induction of a cytotoxic immune response in mice immunised with the gag expression plasmid was also found. The authors of this article attribute the improved properties of their DNA vaccine to a change in the nucleocytoplasmic transport of the mRNA expressed by the DNA vaccine, which was due to the optimised codon usage. The authors maintain that the effect of the altered codon usage on the translation efficiency was only slight.
SUMMARY OF THE INVENTION
[0019] The object of the present invention is to provide a new system for gene therapy and genetic vaccination that overcomes the disadvantages associated with the properties of DNA therapeutic agents and DNA vaccines and that increases the effectiveness of therapeutic agents based on RNA species.
[0020] This object is achieved by the embodiments of the present invention characterised in the claims.
[0021] In particular, a modified mRNA, as well as a pharmaceutical composition containing at least one modified mRNA of the present invention and a pharmaceutically compatible carrier and/or vehicle are provided. The modified mRNA encodes at least one biologically active or antigenic peptide or polypeptide, wherein the sequence of the mRNA comprises at least one modification as set forth herein below as compared to the wild type mRNA. Such modifications may be located in the region coding for the at least one peptide or polypeptide, or in untranslated regions.
[0022] In one aspect, the G/C content of the region of the modified mRNA coding for the peptide or polypeptide is increased relative to that of the G/C content of the coding region of the wild type mRNA coding for the peptide or polypeptide. The encoded amino acid sequence, however, remains unchanged compared to the wild type (i.e. silent with respect to the encoded amino acid sequence).
[0023] This modification is based on the fact that, for efficient translation of an mRNA, the sequence of the region of the mRNA to be translated is essential. In this connection the composition and the sequence of the various nucleotides play an important role. In particular sequences with an increased G (guanosine)/C (cytosine) content are more stable than sequences with an increased A (adenosine)/U (uracil) content. In accordance with the invention, the codons are varied compared to the wild type mRNA, while maintaining the translated amino acid sequence, so that they contain increased amounts of G/C nucleotides. Since several different codons can encode the same amino acid, due to degeneracy of the genetic code, the codons most favourable for the stability of the modified mRNA can be determined and incorporated (alternative codon usage).
[0024] Depending on the amino acid to be coded by the modified mRNA, various possibilities for modifying the mRNA sequence compared to the wild type sequence are feasible. In the case of amino acids that are encoded by codons that contain exclusively G or C nucleotides, no modification of the codon is necessary. Thus, the codons for Pro (CCC or CCG), Arg (CGC or CGG), Ala (GCC or GCG) and Gly (GGC or GGG) do not require any alteration since no A or U is present.
[0025] In the following cases the codons that contain A and/or U nucleotides are altered by substituting other codons that code for the same amino acids, but do not contain A and/or U. Examples include: the codons for Pro, which may be changed from CCU or CCA to CCC or CCG; the codons for Arg, which may be changed from CGU or CGA or AGA or AGG to CGC or CGG; the codons for Ala, which may be changed from GCU or GCA to GCC or GCG; the codons for Gly, which may be changed from GGU or GGA to GGC or GGG.
[0026] In other cases, although A and/or U nucleotides may not be eliminated from the codons, it is however possible to reduce the A and U content by using codons that contain fewer A and/or U nucleotides. For example: the codons for Phe, which may be changed from UUU to UUC; the codons for Leu may be changed from UUA, CUU or CUA to CUC or CUG; the codons for Ser, which may be changed from UCU or UCA or AGU to UCC, UCG or AGC; the codon for Tyr, which may be changed from UAU to UAC; the stop codon UAA, which may be changed to UAG or UGA; the codon for Cys, which may be changed from UGU to UGC; the codon for His, which may be changed from CAU to CAC; the codon for Gln, which may be changed from CAA to CAG; the codons for Ile, which may be changed from AUU or AUA to AUC; the codons for Thr, which may be changed from ACU or ACA to ACC or ACG; the codon for Asn may be changed from AAU to AAC; the codon for Lys, which may be changed from AAA to AAG; the codons for Val, which may be changed from GUU or GUA to GUC or GUG; the codon for Asp, which may be changed from GAU to GAC; the codon for Glu, which may be changed from GAA to GAG.
[0027] In the case of the codons for Met (AUG) and Trp (UGG) there is however no possibility of modifying the sequence.
[0028] The substitutions listed above may be used individually and in all possible combinations in order to increase the G/C content of a modified mRNA compared to the original sequence. Thus for example all codons for Thr occurring in the original (wild type) sequence can be altered to ACC (or ACG). Preferably, however, combinations of the substitution possibilities given above are employed, for example: substitution of all codons coding in the original sequence for Thr to ACC (or ACG) and substitution of all codons coding for Ser to UCC (or UCG or AGC); substitution of all codons coding in the original sequence for Ile to AUC and substitution of all codons coding for Lys to AAG and substitution of all codons coding originally for Tyr to UAC; substitution of all codons coding in the original sequence for Val to GUC (or GUG) and substitution of all codons coding for Glu to GAG and substitution of all codons coding for Ala to GCC (or GCG) and substitution of all codons coding for Arg to CGC (or CGG); substitution of all codons coding in the original sequence for Val to GUC (or GUG) and substitution of all codons coding for Glu to GAG and substitution of all codons coding for Ala to GCC (or GCG) and substitution of all codons coding for Gly to GGC (or GGG) and substitution of all codons coding for Asn to AAC; substitution of all codons coding in the original sequence for Val to GUC (or GUG) and substitution of all codons coding for Phe to UUC and substitution of all codons for Cys to UGC and substitution of all codons coding for Leu to CUG (or CUC) and substitution of all codons coding for Gln to CAG and substitution of all codons encoding Pro to CCC (or CCG); etc.
[0029] Preferably the G/C content of the region of the modified mRNA coding for the peptide or polypeptide is increased by at least 7%, more preferably by at least 15%, and particularly preferably by at least 20% compared to the G/C content of the coded region of the wild type mRNA encoding for the polypeptide.
[0030] In this connection it is particularly preferred to maximize the G/C content of the modified mRNA as compared to that of the wild type sequence. For some applications, it may be particularly advantageous to maximise the G/C content of the modified mRNA in the region encoding the at least one peptide or polypeptide.
[0031] In accordance with the invention, a further modification of the mRNA comprised in the pharmaceutical composition of the present invention is based on an understanding that the translation efficiency is also affected by the relative abundance of different tRNAs in various cells. A high frequency of so-called “rare” codons in an RNA sequence, which are recognized by relatively rare tRNAs, tends to decrease the translational efficiency of the corresponding mRNA, whereas a high frequency of codons recognized by relatively abundant rRNAs tends to enhance the translational efficiency of a corresponding mRNA.
[0032] Thus, according to the invention, the modified mRNA (which is contained in the pharmaceutical composition) comprises a region coding for the peptide or polypeptide which is changed compared to the corresponding region of the wild type mRNA so as to replace at least one codon of the wild type sequence that is recognized by a rare cellular tRNA with a codon recognized by an abundant cellular tRNA, wherein the abundant and rare cellular tRNAs recognize the same amino acid. In other words, the substituted codon in the modified mRNA, which is recognized by a relatively frequent tRNA, encodes the same amino acid as the wild type (unmodified) codon.
[0033] Through such modifications, the RNA sequences are modified so that codons are inserted/substituted that are recognized by abundantly expressed cellular tRNAs. Modifications directed to altering codon usage in a nucleic acid sequence to optimise expression levels of polypeptides encoded therefrom are generally referred to in the art as “codon optimisation.”
[0034] Those tRNAs which are abundant or rare in a particular cell are known to a person skilled in the art; see for example Akashi, Curr. Opin. Genet. Dev. 2001, 11(6): 660-666. Each organism has a preferred choice of nucleotide or codon usage to encode any particular amino acid. Different species vary in their codon preferences for translating mRNA into protein. The codon preferences of a particular species in which a modified mRNA of the present invention is to be expressed will, therefore, at least in part dictate the parameters of codon optimisation for a nucleic acid sequence.
[0035] By means of this modification, according to the invention all codons of the wild type sequence that are recognized by a relatively rare tRNA in a cell may in each case be replaced by a codon that is recognized by a relatively abundant tRNA. As described herein, however, the coding sequence of the peptide or polypeptide is preserved. That is, a relatively abundant tRNA species, which replaces a relatively rare tRNA species in a modified mRNA of the invention, recognizes an amino acid identical to that recognized by the rare tRNA species.
[0036] According to the invention, it is particularly preferred to couple the sequential increase in the G/C fraction of a modified mRNA (particularly, for example, a maximally modified G/C content), with an increase in the number of codons recognized by abundant tRNAs, wherein the amino acid sequence of the peptide or polypeptide (one or more) encoded by the mRNA remains unaltered. This preferred embodiment provides a particularly preferred mRNA species, possessing properties of efficient translation and improved stability. Such preferred mRNA species are well suited, for example, for the pharmaceutical compositions of the present invention.
[0037] Sequences of eukaryotic mRNAs frequently include destabilising sequence elements (DSE) to which signal proteins can bind and thereby regulate the enzymatic degradation of the mRNA in vivo. Accordingly, for the further stabilisation of a modified mRNA of the invention, which may be a component of a pharmaceutical composition of the invention, one or more changes may be made in the wild type mRNA sequence encoding the at least one peptide or polypeptide, so as to reduce the number of destabilising sequence elements present. In accordance with the invention, DSEs located anywhere in an mRNA, including the coding region and in the non-translated regions (3′ and/or 5′ UTR), may be mutated or changed to generate a modified mRNA having improved properties.
[0038] Such destabilising sequences are for example AU-rich sequences (“AURES”) that occur in 3′-UTR regions of a number of unstable mRNAs (Caput et al., Proc. Natl. Acad. Sci. USA 1986, 83: 1670-1674). The RNA molecules contained in the pharmaceutical composition according to the invention are therefore preferably altered as compared to the wild type mRNA so as to reduce the number of or eliminate these destabilising sequences. Such an approach also applies to those sequence motifs recognised by potential endonucleases. Such sequences include, for example, GAACAAG, which is found in the 3′UTR of the gene encoding the transferring receptor (Binder et al., EMBO J. 1994, 13: 1969-1980). Sequence motifs recognized by endonucleases are also preferably reduced in number or eliminated in the modified mRNA of the pharmaceutical composition according to the invention.
[0039] Various methods are known to the person skilled in the art that are suitable for the substitution of codons in the modified mRNA according to the invention. In the case of relatively short coding regions (that code for biologically active or antigenic peptides), the whole mRNA may, for example, be chemically synthesised using standard techniques.
[0040] Preferably, however, base substitutions are introduced using a DNA matrix for the production of modified mRNA with the aid of techniques routinely employed in targeted mutagenesis; see Maniatis et al., Molecular Cloning: A Laboratory Manual, Cold Spring Harbor Laboratory Press, 3 rd Edition, Cold Spring Harbor, N.Y., 2001.
[0041] In this method, a corresponding DNA molecule is therefore transcribed in vitro for the production of the mRNA. This DNA matrix has a suitable promoter, for example a T7 or SP6 promoter, for in vitro transcription, followed by the desired nucleotide sequence for the mRNA to be produced and a termination signal for the in vitro transcription. According to the invention the DNA molecule that forms the matrix of the RNA construct to be produced is prepared as part of a plasmid replicable in bacteria, wherein the plasmid is replicated or amplified during the course of bacterial replication and subsequently isolated by standard techniques. Plasmids suitable for use in the present invention include, but are not limited to pT7Ts (GenBank Accession No. U26404; Lai et al., Development 1995, 121: 2349-2360), the pGEM® series, for example pGEM®-1 (GenBank Accession No. X65300; from Promega) and pSP64 (GenBank-Accession No. X65327); see also Mezei and Storts, Purification of PCR Products, in: Griffin and Griffin (Eds.), PCR Technology: Current Innovation, CRC Press, Boca Raton, Fla., 2001.
[0042] Thus, by using short synthetic DNA oligonucleotides that comprise short single-strand transitions at the corresponding cleavage sites, or by means of genes produced by chemical synthesis, the desired nucleotide sequence can be cloned into a suitable plasmid by molecular biology methods known to the person skilled in the art (see Maniatis et al., above). The DNA molecule is then excised from the plasmid, in which it may be present as a single copy or multiple copies, by digestion with restriction endonucleases.
[0043] The modified mRNA that is contained in the pharmaceutical composition according to the invention may furthermore have a 5′ cap structure (a modified guanosine nucleotide). Examples of suitable cap structures include, but are not limited to m7G(5′)ppp (5′(A,G(5′)ppp(5′)A and G(5′)ppp(5′)G.
[0044] According to a further preferred embodiment of the present invention the modified mRNA comprises a poly-A tail of at least 50 nucleotides, preferably at least 70 nucleotides, more preferably at least 100 nucleotides and particularly preferably at least 200 nucleotides.
[0045] For efficient translation of the mRNA a productive binding of the ribosomes to the ribosome binding site [Kozak sequence: GCCGCCACCAUGG (SEQ ID NO: 13), the AUG forms the start codon] is generally required. In this regard it has been established that an increased A/U content around this site facilitates more efficient ribosome binding to the mRNA.
[0046] In addition, it is possible to introduce one or more so-called IRES (“internal ribosomal entry site”) into the modified mRNA. An IRES may act as the sole ribosome binding site, or may serve as one of the ribosome binding sites of an mRNA. An mRNA comprising more than one functional ribosome binding site may encode several peptides or polypeptides that are translated independently by the ribosomes (“multicistronic mRNA”). Examples of IRES sequences that can be used according to the invention include without limitation, those from picornaviruses (e.g. FMDV), pest viruses (CFFV), polio viruses (PV), encephalomyocarditis viruses (ECMV), foot-and-mouth disease viruses (FMDV), hepatitis C viruses (HCV), classical swine fever viruses (CSFV), murine leukemia virus (MLV), simian immune deficiency viruses (SIV) or cricket paralysis viruses (CrPV).
[0047] According to a further preferred embodiment of the present invention the modified mRNA comprises in the 5′ non-translated and/or 3′ non-translated regions stabilisation sequences that are capable of increasing the half-life of the mRNA in the cytosol.
[0048] These stabilisation sequences may exhibit 100% sequence homology with naturally occurring sequences that are present in viruses, bacteria and eukaryotic cells, or may be derived from such naturally occurring sequences (i.e., may comprise, e.g., mutations substitutions, or deletions in these sequences). Stabilising sequences that may be used in the present invention include, by way of non-limiting example, the untranslated sequences (UTR) of the β-globin gene of Homo sapiens or Xenopus laevis . Another example of a stabilisation sequence has the general formula (C/U)CCAN x CCC(U/A)Py x UC(C/U)CC, which is contained in the 3′UTR of the very stable mRNAs that encode α-globin, α-(I)-collagen, 15-lipoxygenase, or tyrosine hydroxylase (C. F. Holcik et al., Proc. Natl. Acad. Sci. USA 1997, 94: 2410-2414). Obviously such stabilisation sequences may be used individually or in combination, as well as in combination with other stabilisation sequences known to a person skilled in the art.
[0049] For the further stabilisation of the modified mRNA it is preferred that the modified mRNA comprises at least one analogue of a naturally occurring nucleotide. This approach is based on the understanding that RNA-decomposing enzymes present in a cell preferentially recognise RNA comprising naturally occurring nucleotides as a substrate. The insertion of nucleotide analogues into an RNA molecule, therefore, retards decomposition of the RNA molecule so modified, whereas the effect of such analogs on translational efficiency, particularly when inserted into the coding region of the mRNA, may result in either an increase or decrease in translation of the modified RNA molecule.
[0050] The following is a non-limiting list of nucleotide analogues that can be used in accordance with the invention: phosphorus amidates, phosphorus thioates, peptide nucleotides, methylphosphonates, 7-deazaguanosine, 5-methylcytosine and inosine. The preparation of such analogues is known to the person skilled in the art, for example from U.S. Pat. No. 4,373,071, U.S. Pat. No. 4,401,796, U.S. Pat. No. 4,415,732, U.S. Pat. No. 4,458,066, U.S. Pat. No. 4,500,707, U.S. Pat. No. 4,668,777, U.S. Pat. No. 4,973,679, U.S. Pat. No. 5,047,524, U.S. Pat. No. 5,132,418, U.S. Pat. No. 5,153,319, U.S. Pat. Nos. 5,262,530 and 5,700,642. According to the invention such analogues may be present in non-translated and/or translated regions of the modified mRNA.
[0051] Furthermore the effective transfer of the modified mRNA into the cells to be treated or into the organism to be treated may be improved if the modified mRNA is associated with a cationic peptide or protein, or is bound thereto. In particular in this connection the use of protamine as polycationic, nucleic acid-binding protein is particularly effective. It is also possible to use other cationic peptides or proteins such as poly-L-lysine or histones. Procedures for stabilising mRNA are described in EP-A-1083232, whose relevant disclosure is incorporated herein in its entirety.
[0052] For gene therapy applications, for example, wherein a pharmaceutical composition of the invention is used, the modified mRNA therein codes for at least one biologically active peptide or polypeptide that is not formed or is only insufficiently or defectively formed in the patient to be treated. Administration of a modified mRNA encoding the at least one biologically active peptide or polypeptide or a composition thereof to such a patient, therefore, at least partially restores the expression and/or activity of the at least one biologically active peptide or polypeptide in the patient and thereby complements the patient's genetic defect. The direct introduction of a normal, functional gene into a living animal has been studied as a means for replacing defective genetic information. In such studies, nucleic acid sequences are introduced directly into cells of a living animal. The following references pertain to methods for the direct introduction of nucleic acid sequences into a living animal: Nabel et al., (1990) Science 249:1285-1288; Wolfe et al., (1990) Science 247:1465-1468; Acsadi et al. (1991) Nature 352:815-818; Wolfe et al. (1991) BioTechniques 11(4):474-485; and Felgner and Rhodes, (1991) Nature 349:351-352, which are incorporated herein by reference.
[0053] Accordingly, examples of polypeptides coded by a modified mRNA of the invention include, without limitation, dystrophin, the chloride channel, which is defectively altered in cystic fibrosis; enzymes that are lacking or defective in metabolic disorders such as phenylketonuria, galactosaemia, homocystinuria, adenosine deaminase deficiency, etc.; enzymes that are involved in the synthesis of neurotransmitters such as dopamine, norepinephrine and GABA, in particular tyrosine hydroxylase and DOPA decarboxylase, and α-1-antitrypsin, etc. Pharmaceutical compositions of the invention may also be used to effect expression of cell surface receptors and/or binding partners of cell surface receptors if the modified mRNA contained therein encodes for such biologically active proteins or peptides. Examples of such proteins that act in an extracellular manner or that bind to cell surface receptors include for example tissue plasminogen activator (TPA), growth hormones, insulin, interferons, granulocyte-macrophage colony stimulating factor (GM-CFS), and erythropoietin (EPO), etc. By choosing suitable growth factors, the pharmaceutical composition of the present invention may, for example, be used for tissue regeneration. In this way diseases that are characterised by tissue degeneration, for example neurodegenerative diseases such as Alzheimer's disease, Parkinson's disease, etc. and other degenerative conditions, such as arthrosis, can be treated. In these cases the modified mRNA, in particular that contained in the pharmaceutical composition of the present invention, preferably encodes, without limitation, a TGF-β family member, EGF, FGF, PDGF, BMP, GDNF, BDNF, GDF and neurotrophic factors such as NGF, neutrophines, etc.
[0054] A further area of application of the present invention is vaccination, i.e. the use of a modified mRNA for inoculation or the use of a pharmaceutical composition comprising a modified mRNA as an inoculating agent, or the use of a modified mRNA in the preparation of the pharmaceutical composition for inoculation purposes. Vaccination is based on introducing an antigen into an organism or subject, in particular into a cell of the organism or subject. In the context of the present invention, the genetic information encoding the antigen is introduced into the organism or subject in the form of a modified mRNA encoding the antigen. The modified mRNA contained in the pharmaceutical composition is translated into the antigen, i.e. the polypeptide or antigenic peptide coded by the modified mRNA is expressed, and an immune response directed against the polypeptide or antigenic peptide is stimulated. For vaccination against a pathogenic organism, e.g., a virus, a bacterium, or a protozoan, a surface antigen of such an organism may be used as an antigen against which an immune response is elicited. In the context of the present invention, a pharmaceutical composition comprising a modified mRNA encoding such a surface antigen may be used as a vaccine. In applications wherein a genetic vaccine is used for treating cancer, the immune response is directed against tumour antigens by generating a modified mRNA encoding a tumour antigen(s), in particular a protein which is expressed exclusively on cancer cells. Such a modified mRNA encoding a tumour antigen may be used alone or as a component of a pharmaceutical composition according to the invention, wherein administration of either the modified mRNA or a composition thereof results in expression of the cancer antigen(s) in the organism. An immune response to such a vaccine would, therefore, confer to the vaccinated subject a degree of protective immunity against cancers associated with the immunizing cancer antigen. Alternatively, such measures could be used to vaccinate a cancer patient with a modified mRNA encoding a tumour antigen(s) expressed on the patient's cancer cells so as to stimulate the cancer patient's immune response to attack any cancer cells expressing the encoded antigen.
[0055] In its use as a vaccine the pharmaceutical composition according to the invention is suitable in particular for the treatment of cancers (in which the modified mRNA codes for a tumour-specific surface antigen (TSSA), for example for treating malignant melanoma, colon carcinoma, lymphomas, sarcomas, small-cell lung carcinomas, blastomas, etc. A non-limiting list of specific examples of tumour antigens include, inter cilia, 707-AP, AFP, ART-4, BAGE, β-catenin/m, Bcr-abl, CAMEL, CAP-1, CASP-8, CDC27/m, CDK4/m, CEA, CT, Cyp-B, DAM, ELF2M, ETV6-AML1, G250, GAGE, GnT-V, Gp100, HAGE, HER-2/neu, HLA-A*0201-R1701, HPV-E7, HSP70-2M, HAST-2, hTERT (or hTRT), iCE, KIAA0205, LAGE, LDLR/FUT, MAGE, MART-1/melan-A, MC1R, myosin/m, MUC1, MUM-1, -2, -3, NA88-A, NY-ESO-1, p190 minor bcr-abl, Pml/RARα, PRAMS, PSA, PSM, RAGE, RU1 or RU2, SAGE, SART-1 or SART-3, TEUAML1, TPI/m, TRP-1, TRP-2, TRP-2/INT2 and WT1. In addition to the above application, the pharmaceutical composition of the invention may be used to treat infectious diseases, for example, viral infectious diseases such as AIDS (HIV), hepatitis A, B or C, herpes, herpes zoster (chicken pox), German measles (rubella virus), yellow fever, dengue fever etc. (flavi viruses), flu (influenza viruses), haemorrhagic infectious diseases (Marburg or Ebola viruses), bacterial infectious diseases such as Legionnaires' disease ( Legionella ), gastric ulcer ( Helicobacter ), cholera ( Vibrio ), E. coli infections, staphylococcal infections, salmonella infections or streptococcal infections, tetanus ( Clostridium tetani ), or protozoan infectious diseases (malaria, sleeping sickness, leishmaniasis, toxoplasmosis, i.e. infections caused by plasmodium , trypanosomes, leishmania and toxoplasma ). Preferably also in the case of infectious diseases the corresponding surface antigens with the strongest antigenic potential are encoded by the modified mRNA. With the aforementioned genes of pathogenic vectors or organisms, in particular in the case of viral genes, this is typically a secreted form of a surface antigen. Moreover, according to the invention mRNAs preferably coding for polypeptides are employed, because polypeptides generally comprise multiple epitopes (polyepitopes). Polypeptides comprising polyepitopes include but are not limited to, surface antigens of pathogenic vectors or organisms, or of tumour cells, preferably secreted protein forms.
[0056] Moreover, the modified mRNA according to the invention may comprise in addition to the antigenic or therapeutically active peptide or polypeptide, at least one further functional region that encodes, for example, a cytokine that promotes the immune response (e.g., a monokine, lymphokine, interleukin or chemokine, such as IL-1, IL-2, IL-3, IL-4, IL-5, IL-6, IL-7, IL-8, IL-9, IL-10, IL-12, INF-α, INF-γ, GM-CFS, LT-α or growth factors such as hGH).
[0057] Furthermore, in order to increase immunogenicity, the pharmaceutical composition according to the invention may contain one or more adjuvants. The term “adjuvant” is understood in this context to denote any chemical or biological compound that promotes or augments a specific immune response. Various mechanisms may be involved in this connection, depending on the various types of adjuvants. For example, compounds that promote endocytosis of the modified mRNA contained in the pharmaceutical composition by dentritic cells (DC) form a first class of usable adjuvants. Other compounds that activate or accelerate maturation of DC (for example, lipopolysaccharides, TNF-α or CD40 ligand) comprise a second class of suitable adjuvants. In general, any agent which is recognized as a potential “danger signal” by the immune system (LPS, GP96, oligonucleotides with the CpG motif) or cytokines such as GM-CSF, may be used as an adjuvant. Co-administration of an adjuvant enhances an immune response generated against an antigen encoded by the modified mRNA. The aforementioned cytokines are particularly preferred in this aspect. Other known adjuvants include aluminium hydroxide, and Freund's adjuvant, as well as the aforementioned stabilising cationic peptides or polypeptides such as protamine. In addition, lipopeptides such as Pam3Cys are also particularly suitable for use as adjuvants in the pharmaceutical composition of the present invention; see Deres et al, Nature 1989, 342: 561-564.
[0058] The pharmaceutical composition according to the invention comprises, in addition to the modified mRNA, a pharmaceutically compatible carrier and/or a pharmaceutically compatible vehicle. Appropriate methods for achieving a suitable formulation and preparation of the pharmaceutical composition according to the invention are described in “Remington's Pharmaceutical Sciences” (Mack Pub. Co., Easton, Pa., 1980), which is herein incorporated by reference in its entirety. For parenteral administration suitable carriers include for example sterile water, sterile saline solutions, polyalkylene glycols, hydrogenated naphthalene and in particular biocompatible lactide polymers, lactide/glycolide copolymers or polyoxyethylene/polyoxypropylen-e copolymers. Compositions according to the invention may contain fillers or substances such as lactose, mannitol, substances for the covalent coupling of polymers such as for example polyethylene glycol to inhibitors according to the invention, complexing with metal ions or incorporation of materials in or on special preparations of polymer compound, such as for example polylactate, polyglycolic acid, hydrogel or on liposomes, microemulsions, microcells, unilamellar or multilamellar vesicles, erythrocyte fragments or spheroplasts. The respective modifications of the compositions are chosen depending on physical properties such as, for example, solubility, stability, bioavailability or degradability. Controlled or constant release of the active component according to the invention in the composition includes formulations based on lipophilic depot substances (for example fatty acids, waxes or oils). Coatings of substances or compositions according to the invention containing such substances, namely coatings with polymers (for example poloxamers or poloxamines), are also disclosed within the scope of the present invention. Moreover substances or compositions according to the invention may contain protective coatings, for example protease inhibitors or permeability enhancers. Preferred carriers are typically aqueous carrier materials, in which water for injection (WFI) or water buffered with phosphate, citrate or acetate, etc., is used, and the pH is typically adjusted to 5.0 to 8.0, preferably 6.0 to 7.0. The carrier or the vehicle will in addition preferably contain salt constituents, for example sodium chloride, potassium chloride or other components that for example make the solution isotonic. In addition the carrier or the vehicle may contain, besides the aforementioned constituents, additional components such as human serum albumin (HSA), polysorbate 80, sugars or amino acids.
[0059] The concentration of the modified mRNA in such formulations may therefore vary within a wide range from 1 μg to 100 mg/ml. The pharmaceutical composition according to the invention is preferably administered parenterally, for example intravenously, intraarterially, subcutaneously or intramuscularly to the patient. It is also possible to administer the pharmaceutical composition topically or orally.
[0060] The invention thus also provides a method for the treatment of the aforementioned medical conditions or an inoculation method for the prevention of the aforementioned conditions, which comprises the administration of the pharmaceutical composition according to the invention to a subject or patient, in particular a human patient.
[0061] A typical regimen for preventing, suppressing, or treating a pathology related to a viral, bacterial, or protozoan infection, may comprise administration of an effective amount of a vaccine composition as described herein, administered as a single treatment, or repeated as enhancing or booster dosages, over a period up to and including between one week and about 24 months, or any range or value therein.
[0062] According to the present invention, an “effective amount” of a vaccine composition is one that is sufficient to achieve a desired biological effect. It is understood that nature and manner of the administration and the effective dosage may be determined by a medical practitioner based on a number of variables including the age, sex, health, and weight of the recipient, the medical condition to be treated and its stage of progression, the kind of concurrent treatment, if any, frequency of treatment, and the nature of the desired outcome. The ranges of effective doses provided below are not intended to limit the invention, but are provided as representative preferred dose ranges. However, the most preferred dosage will be tailored to the individual subject, as is understood and determinable by one of skill in the art, without undue experimentation. See, e.g., Berkow et al., eds., The Merck Manual, 16th edition, Merck and Co., Rahway, N.J., 1992; Goodman et al., eds., Goodman and Gilman's The Pharmacological Basis of Therapeutics, 8th edition, Pergamon Press, Inc., Elmsford, N.Y., (1990); Avery's Drug Treatment: Principles and Practice of Clinical Pharmacology and Therapeutics, 3rd edition, ADIS Press, LTD., Williams and Wilkins, Baltimore, Md. (1987), Ebadi, Pharmacology, Little, Brown and Co., Boston, Mass. (1985); and Katzung, ed. Basic and Clinical Pharmacology, Fifth Edition, Appleton and Lange, Norwalk, Conn. (1992), which references and references cited therein, are entirely incorporated herein by reference.
[0063] The present invention relates to the use of genetic material (e.g., nucleic acid sequences) as immunizing agents. In one aspect, the present invention relates to the introduction of exogenous or foreign modified DNA or RNA molecules into an individual's tissues or cells, wherein these molecules encode an exogenous protein capable of eliciting an immune response to the protein. The exogenous nucleic acid sequences may be introduced alone or in the context of an expression vector wherein the sequences are operably linked to promoters and/or enhancers capable of regulating the expression of the encoded proteins. The introduction of exogenous nucleic acid sequences may be performed in the presence of a cell stimulating agent capable of enhancing the uptake or incorporation of the nucleic acid sequences into a cell. Such exogenous nucleic acid sequences may be administered in a composition comprising a biologically compatible or pharmaceutically acceptable carrier. The exogenous nucleic acid sequences may be administered by a variety of means, as described herein, and well known in the art.
[0064] Such methods may be used to elicit immunity to a pathogen, absent the risk of infecting an individual with the pathogen. The present invention may be practiced using procedures known in the art, such as those described in PCT International Application Number PCT/US90/01515, wherein methods for immunizing an individual against pathogen infection by directly injecting polynucleotides into the individual's cells in a single step procedure are presented.
[0065] In one aspect, the present invention relates to methods for eliciting immune responses in an individual or subject which can protect the individual from pathogen infection. Accordingly, genetic material that encodes an immunogenic protein is introduced into a subject's cells either in vivo or ex vivo. The genetic material is expressed by these cells, thereby producing immunogenic target proteins capable of eliciting an immune response. The resulting immune response is broad based and involves activation of the humoral immune response and both arms of the cellular immune response.
[0066] This approach is useful for eliciting a broad range of immune responses against a target protein. Target proteins may be proteins specifically associated with pathogens or the individual's own “abnormal” or infected cells. Such an approach may be used advantageously to immunize a subject against pathogenic agents and organisms such that an immune response against a pathogen protein provides protective immunity against the pathogen. This approach is particularly useful for protecting an individual against infection by non-encapsulated intracellular pathogens, such as a virus, which produce proteins within the host cells. The immune response generated against such proteins is capable of eliminating infected cells with cytotoxic T cells (CTLs).
[0067] The immune response elicited by a target protein produced by vaccinated cells in a subject is a broad-based immune response which includes B cell and T cell responses, including CTL responses. It has been observed that target antigen produced within the cells of the host are processed intracellularly into small peptides, which are bound by Class I MHC molecules and presented in the context of Class I on the cell surface. The Class I MHC-target antigen complexes are capable of stimulating CD8 + T cells, which are predominantly CTLs. Notably, genetic immunization according to the present invention is capable of eliciting CTL responses (killer cell responses).
[0068] The CTL response is crucial in protection against pathogens such as viruses and other intracellular pathogens which produce proteins within infected cells. Similarly, the CTL response can be utilized for the specific elimination of deleterious cell types, which may express aberrant cell surface proteins recognizable by Class I MHC molecules.
[0069] The genetic vaccines of the present invention may be administered to cells in conjunction with compounds that stimulate cell division and facilitate uptake of genetic constructs. This step provides an improved method of direct uptake of genetic material. Administration of cell stimulating compounds results in a more effective immune response against the target protein encoded by the genetic construct.
[0070] According to the present invention, modified DNA or mRNA that encodes a target protein is introduced into the cells of an individual where it is expressed, thus producing the target protein. The modified DNA or RNA may be operably linked to regulatory elements (e.g., a promoter) necessary for expression in the cells of the individual. Other elements known to skilled artisans may also be included in genetic constructs of the invention, depending on the application.
[0071] As used herein, the term “genetic construct” refers to the modified DNA or mRNA molecule that comprises a nucleotide sequence which encodes the target protein and which may include initiation and termination signals operably linked to regulatory elements including a promoter and polyadenylation signal (for modified DNA) capable of directing expression in the cells of the vaccinated individual. As used herein, the term “expressible form” refers to gene constructs which contain the necessary regulatory elements operably linked to a coding sequence of a target protein, such that when present in the cell of the individual, the coding sequence is expressed. As used herein, the term “genetic vaccine” refers to a pharmaceutical preparation that comprises a genetic construct.
[0072] The present invention provides genetic vaccines, which include genetic constructs comprising DNA or RNA which encode a target protein. As used herein, the term “target protein” refers to a protein capable of eliciting an immune response. The target protein is an immunogenic protein derived from the pathogen or undesirable cell-type, such as an infected or transformed cell. In accordance with the invention, target proteins may be pathogen-associated proteins or tumour-associated proteins. The immune response directed against the target protein protects the individual against the specific infection or disease with which the target protein is associated. For example, a genetic vaccine comprising a modified DNA or RNA molecule that encodes a pathogen-associated target protein is used to elicit an immune response that will protect the individual from infection by the pathogen.
[0073] DNA and RNA-based vaccines and methods of use are described in detail in several publications, including Leitner et al. (1999, Vaccines 18:765-777), Nagashunmugam et al. (1997, AIDS 11: 1433-1444), and Fleeton et al. (2001, J Infect Dis 183:1395-1398) the entire contents of each of which is incorporated herein by reference.
[0074] In order to test expression, genetic constructs can be tested for expression levels in vitro using cells maintained in culture, which are of the same type as those to be vaccinated. For example, if the genetic vaccine is to be administered into human muscle cells, muscle cells grown in culture such as solid muscle tumor cells of rhabdomyosarcoma may be used as an in vitro model for measuring expression levels. One of ordinary skill in the art could readily identify a model in vitro system which may be used to measure expression levels of an encoded target protein.
[0075] In accordance with the invention, multiple inoculants can be delivered to different cells, cell types, or tissues in an individual. Such inoculants may comprise the same or different nucleic acid sequences of a pathogenic organism. This allows for the introduction of more than a single antigen target and maximizes the chances for developing immunity to the pathogen in a vaccinated subject.
[0076] According to the invention, the genetic vaccine may be introduced in vivo into cells of an individual to be immunized or ex vivo into cells of the individual which are re-implanted after incorporation of the genetic vaccine. Either route may be used to introduce genetic material into cells of an individual. As described herein above, preferred routes of administration include intramuscular, intraperitoneal, intradermal, and subcutaneous injection. Alternatively, the genetic vaccine may be introduced by various means into cells isolated from an individual. Such means include, for example, transfection, electroporation, and microprojectile bombardment. These methods and other protocols for introducing nucleic acid sequences into cells are known to and routinely practiced by skilled practitioners. After the genetic construct is incorporated into the cells, they are re-implanted into the individual. Prior to re-implantation, the expression levels of a target protein encoded by the genetic vaccine may be assessed. It is contemplated that otherwise non-immunogenic cells that have genetic constructs incorporated therein can be implanted into autologous or heterologous recipients.
[0077] The genetic vaccines according to the present invention comprise about 0.1 to about 1000 micrograms of nucleic acid sequences (i.e., DNA or RNA). In some preferred embodiments, the vaccines comprise about 1 to about 500 micrograms of nucleic acid sequences. In some preferred embodiments, the vaccines comprise about 25 to about 250 micrograms of nucleic acid sequences. Most preferably, the vaccines comprise about 100 micrograms nucleic acid sequences.
[0078] The genetic vaccines according to the present invention are formulated according to the mode of administration to be used. One having ordinary skill in the art can readily formulate a genetic vaccine that comprises a genetic construct. In cases where intramuscular injection is the chosen mode of administration, for example, an isotonic formulation is generally used. As described in detail herein above, additives for isotonicity can include sodium chloride, dextrose, mannitol, sorbitol and lactose. Isotonic solutions such as phosphate buffered saline are preferred. Stabilizers can include gelatin and albumin.
[0079] In some embodiments of the invention, the individual is administered a series of vaccinations to produce a comprehensive immune response. According to this method, at least two and preferably four injections are given over a period of time. The period of time between injections may include from 24 hours apart to two weeks or longer between injections, preferably one week apart. Alternatively, at least two and up to four separate injections may be administered simultaneously to different parts of the body.
[0080] While this disclosure generally discusses immunization or vaccination in the context of prophylactic methods of protection, the terms “immunizing” or “vaccinating” are meant to refer to both prophylactic and therapeutic methods. Thus, a method for immunizing or vaccinating includes both methods of protecting an individual from pathogen challenge, as well as methods for treating an individual suffering from pathogen infection. Accordingly, the present invention may be used as a vaccine for prophylactic protection or in a therapeutic manner; that is, as a reagent for immunotherapeutic methods and preparations.
[0081] The amount of a modified nucleic acid sequence generated using the methods of the invention which provides a therapeutically effective dose in the treatment of a patient with, for example, cancer or a pathogen-related disorder can be determined by standard clinical techniques based on the present description. In addition, in vitro assays may optionally be employed to help identify optimal dosage ranges. The precise dose to be employed in the formulation will also depend on the route of administration, and the seriousness of the disease or disorder, and should be decided according to the judgment of the practitioner and each subject's circumstances. However, suitable dosage ranges for intravenous administration are generally directed to achieve a concentration of about 20-500 micrograms of polypeptide encoded by the modified nucleic acid per kilogram body weight. Suitable dosage ranges for intranasal administration are generally directed to achieve a concentration of about 0.01 pg to 1 mg of polypeptide encoded by the modified nucleic acid per kg body weight. Effective doses may be extrapolated from dose-response curves derived from in vitro or animal model test systems.
[0082] The compositions comprising the modified nucleic acid molecules of the invention can be administered for prophylactic and/or therapeutic treatments. In therapeutic applications, compositions are administered to a patient already suffering from a hyperproliferative disorder (such as, e.g., cancer) in an amount sufficient to cure or at least partially arrest the symptoms of the disease and its complications. An amount adequate to accomplish this is defined as a “therapeutically effective amount or dose.” Amounts effective for this use will depend on the severity of the disease and the weight and general state of the patient.
[0083] Compositions comprising modified nucleic acid molecules of the invention can be administered alone, or in combination, and/or in conjunction with known therapeutic agents/compounds used for the treatment of a patient with a particular disorder. For the treatment of a patient with cancer, for example, a composition comprising at least one modified nucleic acid of the invention which encodes a tumour antigen, may be used in conjunction with one or more known cancer therapeutics, such as those described in the Physicians' Desk Reference, 54 th Edition (2000) or in Cancer: Principles & Practice of Oncology , DeVita, Jr., Hellman, and Rosenberg (eds.) 2nd edition, Philadelphia, Pa.: J. B. Lippincott Co., 1985, wherein standard treatment protocols and dosage formulations are presented.
[0084] In addition a method is also provided for determining how to modify the sequence of an mRNA so as to generate a modified mRNA having altered properties, which may be used alone or in a pharmaceutical composition of the invention. In this connection, and in accordance with the invention, the modification of an RNA sequence is carried out with two different optimisation objectives: to maximize G/C content, and to maximize the frequency of codons that are recognized by abundantly expressed tRNAs. In the first step of the process a virtual translation of an arbitrary RNA (or DNA) sequence is carried out in order to generate the corresponding amino acid sequence. Starting from the amino acid sequence, a virtual reverse translation is performed that provides, based on degeneracy of the genetic code, all of the possible choices for the corresponding codons. Depending on the required optimisation or modification, corresponding selection lists and optimisation algorithms are used for choosing suitable codons. The algorithms are executed on a computer, normally with the aid of suitable software. In accordance with the present invention, a suitable software program comprises a source code of Appendix I. Thus, the optimised mRNA sequence is generated and can be output, for example, with the aid of a suitable display device and compared with the original (wild type) sequence. The same also applies with regard to the frequency of the individual nucleotides. The changes compared to the original nucleotide sequence are preferably emphasised. Furthermore, according to a preferred embodiment, naturally occurring stable sequences are incorporated therein to produce an RNA stabilised by the presence of natural sequence motifs. A secondary structural analysis may also be performed that can analyse, on the basis of structural calculations, stabilising and destabilising properties or regions of the RNA.
[0085] Also encompassed by the present invention are modified nucleic acid sequences generated using the above computer-based method. Exemplary modified nucleic acid sequences of the invention include SEQ ID NOs: 3-7, 10 and 11. The present invention also includes pharmaceutical compositions of modified nucleic acid sequences of the invention, including SEQ ID NOs: 3-7, 10 and 11.
BRIEF DESCRIPTION OF THE DRAWINGS
[0086] FIG. 1 shows wild type sequences and modified sequences for the influenza matrix protein.
[0087] FIG. 1A (SEQ ID NO: 1) shows the wild type gene and FIG. 1B (SEQ ID NO: 2) shows the amino acid sequence derived therefrom (1-letter code). FIG. 1C (SEQ ID NO: 3) shows a gene sequence coding for the influenza matrix protein, whose G/C content is increased as compared to that of the wild type sequence. FIG. 1D (SEQ ID NO: 4) shows the sequence of a gene that codes for a secreted form of the influenza matrix protein (including an N-terminal signal sequence), wherein the G/C content of the sequence is increased relative to that of the wild type sequence. FIG. 1E (SEQ ID NO: 5) shows an mRNA coding for the influenza matrix protein, wherein the mRNA comprises stabilising sequences not present in the corresponding wild type mRNA. FIG. 1F (SEQ ID NO: 6) shows an mRNA coding for the influenza matrix protein that in addition to stabilising sequences also contains an increased G/C content. FIG. 1G (SEQ ID NO: 7) likewise shows a modified mRNA that codes for a secreted form of the influenza matrix protein and comprises, as compared to the wild type, stabilising sequences and an elevated G/C content. In FIG. 1A and FIGS. 1C to 1G the start and stop codons are shown in bold type. Nucleotides that are changed relative to the wild type sequence of FIG. 1A are shown in capital letters in 1 C to 1 G.
[0088] FIG. 2 shows wild type sequences and modified sequences according to the invention that encode for the tumour antigen MAGE1.
[0089] FIG. 2A (SEQ ID NO: 8) shows the sequence of the wild type gene and FIG. 2B (SEQ ID NO: 9) shows the amino acid sequence derived therefrom (3-letter code). FIG. 2C (SEQ ID NO: 10) shows a modified mRNA coding for MAGE1, whose G/C content is increased as compared to the wild type. FIG. 2D (SEQ ID NO: 11) shows the sequence of a modified mRNA encoding MAGE1, in which the codon usage has been optimised as frequently as possible with respect to the tRNA present in the cell and to the coding sequence in question. Start and stop codons are shown in each case in bold type.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0090] The following examples describe the invention in more detail and in no way are to be construed as restricting the scope thereof.
Example 1
[0091] As an exemplary embodiment of the process for determining the sequence of a modified mRNA according to the invention, a computer program was established that modifies the nucleotide sequence of an arbitrary mRNA in such a way as to maximise the G/C content of the nucleic acid, and maximise the presence of codons recognized by abundant tRNAs present in a particular cell(s). The computer program is based on an understanding of the genetic code and exploits the degenerative nature of the genetic code. By this means a modified mRNA having desirable properties is obtained, wherein the amino acid sequence encoded by the modified mRNA is identical to that of the unmodified mRNA sequence. Alternatively, the invention may encompass alterations in either the G/C content or codon usage of an mRNA to produce a modified mRNA.
[0092] The source code in Visual Basic 6.0 (program development environment employed: Microsoft Visual Studio Enterprise 6.0 with Servicepack 3) is given in the Appendix I.
Example 2
[0093] An RNA construct with a sequence of the lac-Z gene from E. coli optimised with regard to stabilisation and translational efficiency was produced with the aid of the computer program of Example 1. A G/C content of 69% (compared to the wild type sequence of 51%; C. F. Kalnins et al., EMBO J. 1983, 2(4): 593-597) was achieved in this manner. Through the synthesis of overlapping oligonucleotides that comprise the modified sequence, the optimised sequence was produced according to methods known in the art. The terminal oligonucleotides have the following restriction cleavage sites: at the 5′ end an EcoRV cleavage site, and at the 3′ end a BglII cleavage site. The modified lacZ sequence was incorporated into the plasmid pT7Ts (GenBank Accession No. U26404; C. F. Lai et al., see above) by digestion with EcoRV/BglII. pT7Ts contains untranslated region sequences from the β-globin gene of Xenopus laevis at the 5′ and 3′ ends. The plasmid was cleaved with the aforementioned restriction enzymes to facilitate insertion of the modified lacZ sequence having compatible 5′ and 3′ termini.
[0094] The pT7Ts-lac-Z construct was propagated in bacteria and purified by phenol-chloroform extraction. 2 μg of the construct were transcribed in vitro using methods known to a skilled artisan and the modified mRNA was produced.
Example 3
[0095] The gene for the influenza matrix protein (wild type sequence, see FIG. 1A ; derived amino acid sequence, see FIG. 1B ) was optimised with the aid of the computer program according to the invention of Example 1. The G/C-rich sequence variant shown in FIG. 1C (SEQ ID NO: 3) was thereby formed. A G/C-rich sequence coding for a secreted form of the influenza matrix protein, which includes an N-terminal signal sequence was also determined (see FIG. 1D ; SEQ ID NO: 4). The secreted form of the influenza matrix protein has the advantage of increased immunogenicity as compared to that of the non-secreted form.
[0096] Corresponding mRNA molecules were designed starting from the optimised sequences. The mRNA for the influenza matrix protein, optimised with regard to G/C content and codon usage, was additionally provided with stabilising sequences in the 5′ region and 3′ region (the stabilisation sequences derive from the 5′-UTRs and 3′-UTRs of the β-globin-mRNA of Xenopus laevis ; pT7Ts-Vektor in C. F. Lai et al., see above). See also FIG. 1E ; SEQ ID NO: 5, which includes only stabilising sequences and 1 F; SEQ ID NO: 6, which includes both increased G/C content and stabilising sequences. The mRNA coding for the secreted form of the influenza matrix protein was likewise also sequence optimised in the translated region and provided with the aforementioned stabilising sequences (see FIG. 1G ; SEQ ID NO: 7).
Example 4
[0097] The mRNA encoding the tumour antigen MAGE1 was modified with the aid of the computer program of Example 1. The sequence shown in FIG. 2C (SEQ ID NO: 10) was generated in this way, and has a 24% higher G/C content (351 G, 291 C) as compared to the wild type sequence (275 G, 244 C). In addition, by means of alternative codon usage, the wild type sequence was improved with regard to translational efficiency by substituting codons corresponding to tRNAs that are more abundant in a target cell (see FIG. 2D ; SEQ ID NO: 11). The G/C content was likewise raised by 24% by the alternative codon usage.
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The present invention relates to a pharmaceutical composition containing an mRNA that is stabilised by sequence modifications in the translated region and is optimised for the translation. The pharmaceutical composition according to the invention is particularly suitable as an inoculating agent as well as a therapeutic agent for tissue regeneration. In addition a process is described for determining sequence modifications that serve for the stabilisation and translation optimisation of mRNA.
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FIELD OF INVENTION
[0001] The present invention relates to an improved process for the preparation of Coenzymes. The invention also relates to novel intermediates for the preparation of coenzymes, and process for the preparation of the intermediates. The present invention particularly relates to an improved process for the preparation of Coenzyme Q, and more particularly Conenzyme Q 9 and Coenzyme Q 10 . Still more particularly this invention relates to regio and stereo controlled process for the preparation of Coenzyme Q 9 and Coenzyme Q 10 of formula I.
[0000]
[0000] where n=9 (Coenzyme CoQ 9 ), and where n=10 (Coenzyme CoQ 10 ).
[0002] In the description given below the Coenzyme CoQ 9 is referred to as formula I 9 and Coenzyme CoQ 10 as formula I 10
BACKGROUND AND PRIOR ART
[0003] These coenzymes belong to the class of ubiquinones that occur in all aerobic organisms from bacteria to plants and animals—the name ubiquinone suggests its ubiquitous occurrence. They are involved in mitochondrial processes such as respiration and act as antioxidants.
[0004] The present invention also provides novel Grignard reagent that is useful for the preparation of above mentioned coenzymes and a process for its preparation.
[0005] The coenzyme Q 10 in human has 10 isoprenoid units, and termed as CoQ 10 . CoQ 10 is present in virtually every cell in the human body and is known as the “miracle nutrient”, and plays a vital role in maintaining human health and vigor, maintenance of heart muscle strength, enhancement of the immune system, quenching of free radical in the battle against aging to name a few (“The miracle nutrient coenzyme” Elsevier/North—Holland Biomedical Press, New York, 1986; “Coenzyme Q: Bioechemistry, Bioenergetics, and clinical Applications of Ubiquinone” Wiley, New York, 1985; “Coenzyme Q, Molecular Mechanism in Health and Disease” CRC press).
[0006] As depicted above Coenzyme Q 9 and Coenzyme Q 10 of the formula I have 2,3-dimethoxy-1,4-benzoquinone nucleus as a head group with a side chain of n isoprene units. The poly prenyl side chain in Coenzyme Q has all-trans configuration. One of the methods of synthesis of these Coenzymes is coupling of the “benzoquinone nucleus” with the “polyprenyl side chain” of solanesol of the formula 3a 9 , where x=—OH and decaprenol of the formula 3a 10 , where x=—OH. with retention of its original double bond geometry.
[0000]
[0007] Various methods for introducing polyprenyl side chain into quinone nucleus, to prepare Coenzymes are found in literature. These methods involve functionalisation of the two coupling partners, the “quinone nucleus” and the “polyprenyl chain”.
[0008] Method 1: Polyprenyl alcohol and hydroquinone using zinc chloride as catalyst; reported in Huanxue Yu Nianhe (2002), 6 267(2002) which is shown in the Scheme 1 given below
[0000]
[0009] Decaprenol of the formula 3a 10 (1.8 g) dissolved in ether is treated with 2,3-dimethoxy-5-methyl benzohydroquinone of the formula 4, zinc chloride (anhydrous, 0.28 g), glacial acetic acid (0.02 ml) and stirred for 2 hours under nitrogen atmosphere. Ferric chloride solution is added to the above reaction mixture, stirred for ten minutes. The ethereal layer is then separated, dried and evaporated to give 2.2 g of crude CoQ 10 which is purified by column chromatography to give 0.56 g of the pure CoQ 10 of the formula I 10 with an overall yield of 20% (mp 45-46° C., Lit. mp 48-50° C.).
[0010] Low melting point obtained indicates the presence of cis-isomer and thereby making the process not stereoselective. The yield is also too low for commercialization of the process.
[0011] Method 2: By making π-Allyl Nickel bromide complex and protected quinone nucleus; reported in Bull. Chem. Soc. Jpn 47, 3098(1974), U.S. Pat. No. 3,896,153(1975) which is shown in scheme 2
[0000]
[0012] Nickel tetracarbonyl 4.5 g (15% solution in benzene) is treated with decaprenyl bromide of the formula 3b 10 10.0 g (15% solution in Benzene) at 50° C. for 4-4.5 hrs. The solution is cooled to below 10° C. and the benzene and excess nickel carbonyl is removed under reduced pressure. Decaprenyl nickel bromide of the formula 5 thus formed is then reacted with 6-bromo-2,3-dimethoxy-5-methyl-1,4-hydroquinone diacetate of the formula 6 in 30 ml of hexamethyl phosphoramide at 75° C. for 7 hours yielding 2.2 g of condensed product of the formula 7 with 40% yield. The condensed product of the formula 7 (0.8 g) is added to a suspension of lithium aluminum hydride in 20 ml of dry ether and refluxed for 24 hours. The excess lithium aluminum hydride is decomposed and the product hydroquinone is extracted in ether.
[0013] The hydroquinone is oxidized with aqueous ferric chloride at room temperature for 3 hour to give the final product CoQ 10 which is further purified by column chromatography to yield the COQ 10 of the formula I 10 with mp 20-22° C. (Lit. mp 48-50° C.) with 69% yield.
[0014] Author attributes the low melting point to the presence of cis isomer. The process is therefore not stereoselective. Further, the nickel tetracarbonyl used in the process is highly flammable, has the risk of explosion and highly toxic chemical, and cannot be used industrially. The overall yield of the process is only 27.6%. The process is therefore not suitable for industry.
[0015] Method 3: From allyl-stannyl and unprotected quinone using borontrifluoride etherate; reported in J. Org. Chem. 45, 4077 (1980), Chemistry Letters 885(1979) as shown in scheme 3.
[0000]
[0016] Trimethylstannyl lithium in tetrahydrofuran is slowly added to decaprenyl bromide of the formula 3b 10 at −78° C. to −60° C. and the reaction mixture is allowed to warm to room temperature. The reaction mixture is quenched in brine and the organic layer evaporated to form trimethyl decaprenyl stannanes of the formula 9. The stannyl reagent (0.42 mmol) in a mixture of methylene dichloride (25 ml) and isooctane (1 ml) is added to 2,3-dimethoxy-5-methylbenzoquinone (0.111 g, 0.61 mmol) and borontrifluoride etherate (2.6 mmol) in a mixture of methylene chloride (25 ml) and isooctane (1 ml) at −50° C. and the reaction mixture is maintained at the same temperature for 2 hours. The resulting product is isolated and chromatographed on silica gel to afford the starting quinone (70 mg) and CoQ 10 of the formula I 10 (189 mg) (86% trans).
[0017] The method forms 14% cis isomer and therefore far from stereo selective. The reaction does not go to completion and results in poor yield and not suitable for industry.
[0018] Method 4: From polyprenyl alcohol and quinone nucleus with silica-alumina as catalyst reported in U.S. Pat. No. 3,998,858(1976) as shown in scheme 4
[0000]
[0019] 2,3-dimethoxy-5-methyl-1,4-benzohydroquinone of the formula 4, (11 g) is reacted with boric acid (3.6 g) in toluene and water removed azeotropically. The residue is treated with silica-alumina (17 g) and a solution of decaprenol (14 g in 10 ml hexane, 94% purity) and stirred for 1 hour at 30° C. The adsorbent is removed and the filtrate is washed with water, and concentrated, and extracted in ether. The ethereal extract is treated with silver oxide (6 g) and allowed to stand overnight. The reaction mixture is filtered and concentrated to form 16.3 g of crude CoQ 10 , which is purified by column chromatography, followed by crystallization with acetone to give 8.5 g of CoQ 10 of the formula I 10 (Lit. mp 49° C.).
[0020] The melting point value indicates that process may form a stereoselective process using a simple technique of silica-alumina. However the ratio of silica and alumina to be used and also the respective grades would be critical for the reaction and is not mentioned. The inventors of the present invention tried various grades of silica-alumina and found that the reaction does not proceed.
[0021] Method 5: Polyprenyl alcohol and quinone nucleus reported in Chemistry Letters 1597(1988), as shown in scheme 5
[0000]
[0022] Isodecaprenol compound of the formula 10 (38.8 g, 72% purity) is reacted with 2,3 dimethoxy 5 methyl 1,4 benzohydroquinone compound of formula 4 (75.1 g) in the presence of borontrifluoride etherate in hexane and nitromethane at 43° C. The reaction mixture is quenched in aqueous medium and the nitromethane and the hexane layer is separated. The hexane layer is oxidized with ferric chloride hexahydrate in isopropanol at room temperature. The crude CoQ 10 of the formula I 10 is obtained in 51% yield with 8% Z isomer
[0023] The process forms 8% cis isomer and therefore not stereo selective. Boron trifluoride etherate is a corrosive chemical and not useful for commercialisation.
[0024] Thus literature does not provide a stereoselective process for coupling of the benzoquinone with the polyprenyl side chain for the preparation of Coenzymes Q, namely CoQ 9 and CoQ 10 . As shown in the coupling reactions mentioned above, 8%-15% of cis isomer is formed.
[0025] It was observed that purification of such a mixture to get the desired all-trans isomer of CoQ 9 and CoQ 10 with less than 1% cis, results in 25-30% purification loss. This would decrease the overall yield of production of these coenzymes mainly CoQ 9 and CoQ 10 , thereby making the commercial process of making the Coenzyme Q 9 or Coenzyme Q 10 cost ineffective.
[0026] Scope of clinical application of coenzymes specially CoQ 10 is becoming wider with its increasing broadband use Therefore if a cost effective process is developed for the preparation of COQ 10 it will greatly help in making this coenzyme easily and at affordable prices.
[0027] Preparation of coenzymes CoQ n where n represents the number of isoprenyl units, namely CoQ 9 or CoQ 10 , by the coupling of the two key units viz the “benzoquinone nucleus” and the “polyprenyl side chain” should be a straightforward route. However as discussed in prior art, the attempts with such coupling, results in isomerisation of the polyprenyl chain and the geometrical configuration of the chain is not retained. Therefore, the focus should be on the “stereoselective” coupling reaction of the “benzoquinone nucleus” with the corresponding “polyprenyl side chain” to obtain CoQ n where n represents the number of isoprenyl units. Such a condensation would enhance the cost effectiveness of the preparation of these coenzymes mainly Q 9 or Q 10 .
[0028] The inventors have observed that a simple, straightforward, stereo selective process for the preparation of coenzyme CoQ 9 or CoQ 10 of the formulae I 9 and I 10 respectively can be developed, by Grignard coupling of the benzoquinone nucleus and the polyprenyl side chain. For such a coupling the “benzoquinone nucleus” has to be converted to the required Grignard reagent with suitable protecting groups. The protecting groups used in literature for making Grignard reagent of the “benzoquinone nucleus” are methoxyethoxymethyl and methyl of the formula IIb & IIc.
[0000]
[0029] Literature method for making Grignard reagent compound of formula IIb from the compound of the formula 2 as reported in J. Org. Chem. 37 1889 (1972), U.S. Pat. No. 4,270,003 (1981), Synthesis (1981) 469-471 (1982) comprises the methods as depicted in Scheme 6a and Scheme 6b.
[0000]
[0030] In the method described in the Scheme 6a, 2,3 dimethoxy-5-methyl 1,4 benzoquinone compound of the formula 2 is brominated to form compound of formula 12. The bromination is effected using bromine in carbon tetrachloride and the product of the formula 12 is isolated by washing with ethanol and recrystallizing from petroleum ether, in 74% yield. The compound of the formula 12 is reduced employing aqueous sodium hydrosulphite solution in presence of methanol to get the compound of the formula 13. The compound of the formula 13 is finally converted to compound of the formula 14a by alkylation. The alkylation is carried out in presence of 50% sodium hydride in mineral oil (106 g) which is added in small portions to a stirred solution of 6-bromo-2,3-dimethoxy-5-methyl hydroquinone compound of formula 12 (262.9 g) in 4 litres of N,N dimethyl formamide at −20° C. Chloromethyl 2-methoxyethyl ether (273 g) is added dropwise over a 2 hours period and the mixture is allowed to warm to room temperature. Excess sodium hydride is destroyed with ethanol and the reaction mixture quenched in water. The ethereal layer containing the extracted product is concentrated and the residue purified by column to obtain the compound of formula 14a in 91% yield. The compound of the formula 14a is converted to the compound of the formula IIb, by reacting with magnesium in presence of tetrahydrofuran.
[0031] Yield of brominating 3,4 dimethoxy-5-methyl 1,4 benzoquinone, is only 74% which is low for such a simple reaction. The solvent used is toxic and not suitable for scale up. The inventors observed that reduction using aqueous sodium hydrosulphite solution gives yield of the compound of the formula 13 in not more than 40% and therefore not suitable for the industrial production. Further we observed that bromination followed by reduction of the benzoquinone to obtain compound of formula 13, results in low purity of not more than 76%.
[0032] The alkylation process uses N,N dimethyl formamide as a solvent and in large excess, 15 times the weight of the bromo compound of the formula 13. N,N dimethyl formamide is a costly solvent and such large excess is not suitable for industry. Sodium hydride used as a base is hazardous and is always present in suspension in oil. The oil also gets extracted in the solvent in which the product compound of formula 14a gets extracted. Thus the process is not compatible to the industry.
[0033] Another method of making 2,3 dimethoxy 5-bromo 6-methyl 1,4 hydroquinone is shown in Scheme 6 b
[0000]
[0034] In this method, 2,3-dimethoxy-1,4-hydroquinone of formula 4 is brominated in chloroform at 5° C., and the product isolated from chloroform is in quantitative yield.
[0035] We observed that bromination at 5° C. leads to incompletion of reaction and isolation of product from chloroform results in yield less than 75%
[0036] The Grignard reagent of formula IIc is prepared as given in scheme 6c
[0000]
[0037] In the process depicted in Scheme 6c, 2,3 dimethoxy 5 methyl benzoquinone of the formula 2 is brominated in room temperature in carbon tetrachloride in 75% yield, reduced with Zinc and acetic acid with 80% yield and methylated with dimethyl sulphate to get the compound of the formula 14b in 62% yield. The compound of the formula 14b is converted to compound of the formula IIc. Yield at each stage of the process is not substantial for mass scale production.
[0038] The inventors observed that the above process of reduction with zinc and acetic acid, and methylation after bromination results in purity of compound of formula 14b, which is not more than 76%.
[0039] The inventors have found that to avoid the drawbacks of the hitherto known processes exemplified above, the coenzyme CoQ 9 or CoQ 10 may be prepared by a simple, straightforward, stereoselective process of coupling of the benzoquinone nucleus with polyprenyl side chain using Grignard reaction of the formula IIb and IIc made by an improved process as more particularly defined hereinafter.
[0040] While developing the improved process for the preparation of the Grignard reagents of the formulae IIb and IIc, the inventors developed a new Grignard reagent of the formula IIa.
[0000]
OBJECTIVE OF THE INVENTION
[0041] The main objective of the present invention is to provide an improved process for the stereoselective preparation of the Coenzymes of formula I, namely, CoQ 9 and CoQ 10 of the formulae I 9 and I 10 respectively as given above.
[0042] Another objective of the present invention is to provide an improved process for the preparation of the coenzymes, namely, CoQ 9 and CoQ 10 of the formulae I 9 and I 10 respectively, which is simple, cost effective and commercially viable.
[0043] Still another objective of the present invention is to provide an improved process for the preparation of the coenzymes Q, namely, CoQ 9 and CoQ 10 of the formulae I 9 and I 10 respectively with high yield (50-56%) and purity 98%
[0044] Yet another objective of the present invention is to provide an improved process for the preparation of coenzymes I 9 and I 10 by stereospecific coupling of the polyprenyl side chain of formula 3a or 3b_with the Grignard reagents of the formula II.
[0045] Still another objective of the present invention is to provide intermediates of the formula III, useful for preparing the coenzymes of formula I.
[0046] Still another objective of the present invention is to provide a process for the preparation of intermediates of formula III useful for preparing the coenzyme of formula I.
[0047] Still another objective of the present invention is to provide a novel Grignard reagent of the formula IIa useful for preparing the coenzyme of formula I.
[0048] Yet another objective of the present invention is to provide a process for the preparation of novel Grignard reagent of the formula IIa useful for the preparation of the coenzymes of formula I.
[0049] Yet another objective of the present invention is to provide an improved process for the preparation of Grignard reagents of the formula IIb and IIc useful for the preparation of the coenzymes of formula I.
SUMMARY OF INVENTION
[0050] Thus the present invention relates to an improved process for the preparation of coenzyme of formula I, as shown in scheme A below:
[0000]
[0000] where n is an integer selected from 9 or 10; R1 and R2 are same or different and are selected from —OCH 2 OCH 2 CH 2 OCH 3 or —OMe, with the proviso that when R2 is —OCH 2 OCH 2 CH 2 OCH 3 , then R1 is not —OMe.
[0051] According to a further aspect of the invention, there is provided preparation of coenzyme CoQ 10 (n=10) of the formula I 10 as shown in scheme 7 below:
[0000]
[0000] where R1 and R2 are same or different and are selected from —OCH 2 OCH 2 CH 2 OCH 3 or —OMe, with the proviso that when R2 is —OCH 2 OCH 2 CH 2 OCH 3 , then R1 is not —OMe
[0052] According to still another aspect of the invention, there is provided preparation of coenzyme CoQ 9 (n=9) of the formula I 9 as shown in scheme 8 below:
[0000]
[0053] where R1 and R2 are same or different and are selected from —OCH 2 OCH 2 CH 2 OCH 3 or —OMe, with the proviso that when R2 is —OCH 2 OCH 2 CH 2 OCH 3 , then R1 is not —OMe
[0054] According to yet another aspect of the invention there is provided a novel intermediate of formula III useful for the preparation of coenzymes of formula I
[0000]
where R1 and R2 are selected from —OCH 2 OCH 2 CH 2 OCH 3 or —OMe, and n is selected from 9 or 10, with the proviso that when R2 is —OCH 2 OCH 2 CH 2 OCH 3 , then R1 is not —OMe.
[0056] According to yet further aspect of the invention there is provided an improved process for the preparation of compound of formula III, useful for the preparation of coenzymes of formula I
[0000]
where R1 and R2 are same or different and are selected from —OCH 2 OCH 2 CH 2 OCH 3 or —OMe, and n is selected from 9 or 10, with the proviso that when R2 is —OCH 2 OCH 2 CH 2 OCH 3 , then R1 is not —OMe;
[0058] which comprises,
[0059] i) reacting Grignard reagents of formula II,
[0000]
[0000] with compounds of formula 3,
[0000]
where n is selected from 9 or 10 in presence of cuprous halide in a solvent under inert atmosphere at a temperature in the range of −5° C. to 25° C.
[0061] According to another aspect of the invention there is provided a novel Grignard reagent of formula IIa, useful for the preparation of coenzymes of formula I, as shown in scheme 9 below:
[0000]
[0062] According to a still further aspect of the invention there is provided an improved process for the preparation of Grignard reagent of the formula IIb, useful for the preparation of coenzymes of formula I as shown in scheme 10 below:
[0000]
[0063] According to a yet further aspect of the invention there is provided a process for the preparation of Grignard reagent of the formula IIc, useful for the preparation of coenzymes of formula I as shown in scheme 11 below:
[0000]
DETAILED DESCRIPTION
[0064] The present invention provides an improved process for the preparation of the coenzymes of formula I, as shown in the Scheme-A
[0000]
[0000] where n is an integer selected from 9 or 10; R1 and R2 are same or different and are selected from —OCH 2 OCH 2 CH 2 OCH 3 or —OMe, with the proviso that when R2 is —OCH 2 OCH 2 CH 2 OCH 3 , then R1 is not —OMe.
[0065] which comprises,
[0066] i) reacting Grignard reagent of formula II,
[0000]
where R1 and R2 are same or different and are selected from —OCH 2 OCH 2 CH 2 OCH 3 or —OMe, with the proviso that when R2 is —OCH 2 OCH 2 CH 2 OCH 3 , then R1 is not —OMe;
with compound of formula 3,
[0000]
where n is an integer selected from 9 or 10, in presence of cuprous halide in a solvent under inert atmosphere at a temperature in the range of −5° C. to 25° C., to obtain an intermediate of formula III;
[0000]
[0069] ii) deprotecting the compound of formula III (wherein at least one of R1 and R2 is —OCH 2 OCH 2 CH 2 OCH 3 ) to obtain the corresponding hydroquinone;
[0070] iii) oxidizing the compound of step (i) or (ii) to obtain the coenzyme of formula I;
[0071] iv) isolating the compound of formula I; and
[0072] v) purifying and crystallizing the coenzyme of formula I by conventional methods.
[0073] According to an embodiment of the present invention, there is provided a process for the preparation coenzyme, CoQ 10 of the formula I 10 as shown in scheme 7:
[0000]
[0000] where R1 and R2 are same or different and are selected from —OCH 2 OCH 2 CH 2 OCH 3 or —OMe, with the proviso that when R2 is —OCH 2 OCH 2 CH 2 OCH 3 , then R1 is not —OMe
[0074] which comprises,
[0075] i) reacting Grignard reagent of formula II,
[0000]
where R1 and R2 are same or different and are selected from —OCH 2 OCH 2 CH 2 OCH 3 or —OMe, with the proviso that when R2 is —OCH 2 OCH 2 CH 2 OCH 3 , then R1 is not —OMe;
with compound of formula 3b,
[0000]
[0000] in presence of cuprous halide in a solvent under inert atmosphere at a temperature in the range of −5° C. to 25° C., to obtain an intermediate of formula IIIb;
[0000]
[0077] ii) deprotecting the compound of formula IIIb (where at least one of R1 and R2 is —OCH 2 OCH 2 CH 2 OCH 3 ) to obtain a hydroquinone;
[0078] iii) oxidizing the compound of step (i) or (ii) to obtain the coenzyme CoQ 10 of formula I 10 ;
[0079] iv) isolating the compound of formula I 10 ; and
[0080] v) purifying the coenzyme CoQ 10 of formula I 10 and further crystallizing by conventional method to obtain yellow to orange crystals of the coenzyme CoQ 10 of formula I 10 .
[0081] According to another embodiment of the present invention, there is provided a process for the preparation coenzyme, CoQ 9 of the formula I 9 as shown in scheme 8:
[0000]
[0000] where R1 and R2 are same or different and are selected from —OCH 2 OCH 2 CH 2 OCH 3 or —OMe, with the proviso that when R2 is —OCH 2 OCH 2 CH 2 OCH 3 , then R1 is not —OMe
[0082] which comprises,
[0083] i) reacting Grignard reagents of formula II,
[0000]
where R1 and R2 are same or different and are selected from —OCH 2 OCH 2 CH 2 OCH 3 or —OMe, with the proviso that when R2 is —OCH 2 OCH 2 CH 2 OCH 3 , then R1 is not —OMe;
with compound of formula 3a,
[0000]
[0000] in presence of cuprous halide in a solvent under inert atmosphere at a temperature in the range of −5° C. to 25° C., to obtain an intermediate of formula IIIa;
[0000]
[0085] ii) deprotecting the compound of formula IIIa (wherein at least one of R1 and R2 is —OCH 2 OCH 2 CH 2 OCH 3 ) to obtain a hydroquinone;
[0086] iii) oxidizing the compound of step (i) or (ii) to obtain the coenzyme CoQ 9 of formula I 9 ;
[0087] iv) isolating the compound of formula I 9 ; and
[0088] v) purifying the coenzyme CoQ 9 of formula I 9 and further crystallizing by conventional method to obtain yellow to orange crystals of the coenzyme CoQ 9 of formula I 9 .
[0089] According to still another embodiment of the present invention there is provided novel intermediate of formula III useful in the preparation of coenzymes of formula I
[0000]
where R1 and R2 are selected from —OCH 2 OCH 2 CH 2 OCH 3 or —OMe, and n is selected from 9 or 10, with the proviso that when R2 is —OCH 2 OCH 2 CH 2 OCH 3 , then R1 is not —OMe.
[0091] According to yet another embodiment of the present invention, there is provided an improved process for the preparation of intermediates of formula III useful in the preparation of coenzymes of formula I.
[0000]
where R1 and R2 are same or different and are selected from —OCH 2 OCH 2 CH 2 OCH 3 or —OMe, and n is selected from 9 or 10, with the proviso that when R2 is —OCH 2 OCH 2 CH 2 OCH 3 , then R1 is not —OMe,
[0093] which comprises,
[0094] i) reacting Grignard reagents of formula II,
[0000]
where R1 and R2 are same or different and are selected from —OCH 2 OCH 2 CH 2 OCH 3 or —OMe, with the proviso that when R2 is —OCH 2 OCH 2 CH 2 OCH 3 , then R1 is not —OMe;
with compound of formula 3,
[0000]
where n is selected from 9 or 10, in presence of cuprous halide in a solvent under inert atmosphere at a temperature in the range of −5° C. to 25° C.
[0097] According to still another embodiment of the present invention, there is provided novel Grignard reagent of formula IIa useful in the preparation of coenzymes of formula I
[0000]
[0098] According to yet another embodiment of the present invention, there is provided a process for the preparation of the novel Grignard reagent of the formula IIa, as shown in the Scheme 9
[0000]
[0099] which comprises,
[0100] (i) brominating the compound of the formula 15
[0000]
[0000] by known method, to obtain compound of formula 16;
[0000]
[0101] (ii) Alkylating the compound of the formula 16 obtained in step (i) with methoxyethoxymethyl chloride in the presence of a base, an alkali metal alkoxide or metal hydride, to obtain 2,3-dimethoxy-5-methyl-6-bromohydroquinone-1,4-dimethoxyethoxy methyl ether compound of formula 17;
[0000]
[0102] (iii) Reacting the compound of the formula 17 obtained in step (ii) with magnesium in presence of iodine and dibromoethane, using ether as a solvent at a temperature in the range of 0-65° C., to obtain the novel Grignard reagent of the formula IIa ;
[0103] (iv) cooling the resulting reaction mixture to room temperature, filtering to get the novel Grignard reagent in solution.
[0104] The compound of formula 15 can be prepared by methods known in the literature. Synthesis of this novel Grignard reagent is most economical as it can be made from the compound of formula 15, unlike the known Grignard reagents of formula IIb and IIc that are made from 2,3 dimethoxy-5-methyl 1,4 benzoquinone (CoQ 0 ), thereby having more number of steps in their preparation. Presence of only one protecting group of methoxyethoxymethyl in compound of formula IIa, reduces the requirement of the reagent methoxyethoxyethyl ether as compared to that required in dimethoxyethoxy-methyl ether in IIb, thus making it more cost effective. At the same time cleaving of the protecting group of the formula IIa employed in the present invention results in the formation of the moiety “2,3,4 trimethoxy 6-methyl phenol” that can be easily oxidised with an inexpensive chemical like ferric chloride unlike cerric ammonium nitrate an expensive oxidising agent required for methyl protection when compound of formula IIc is used.
[0105] According to still another embodiment of the present invention, there is provided an improved process for the preparation of the Grignard reagent of the formula IIb as shown in Scheme 10
[0000]
[0106] which comprises,
[0107] i. Reducing 2,3-dimethoxy-5-methyl-1,4 benzoquinone (CoQ 0 ) of the formula 2,
[0000]
[0000] with aqueous sodium hydrosulphite, in alkaline medium, in the presence of a water immiscible organic solvent, separating the organic phase, and evaporating the organic phase to obtain a concentrated residue, to which was added a hydrocarbon solvent to precipitate out compound of formula 4
[0000]
[0108] ii. Brominating the resulting compound of the formula 4 with bromine in chlorinated hydrocarbon solvent at a temperature in the range of 0-25° C.,
[0109] iii. Quenching the resultant reaction mixture in step (ii) in aqueous medium to obtain aqueous and organic phase, separating the organic phase and evaporating the organic phase to obtain a concentrated residue, to which was added a hydrocarbon solvent to precipitate out 2,3-dimethoxy-5-methyl-6-bromo 1,4 hydroquinone of the formula 13
[0000]
[0110] iv. Alkylating the 2,3 dimethoxy-5-methyl-6-bromo 1,4 hydroquinone of the formula 13 obtained in step (iii) with methoxyethoxymethyl chloride in the presence of a base selected from an alkali metal alkoxide or metal hydride, to obtain 2,3-dimethoxy-5-methyl-6-bromo hydroquinone1,4 dimethoxyethoxymethyl ether compound of formula 14a,
[0000]
[0111] v. Reacting the compound of the formula 14a obtained in step (iv) with magnesium in presence of iodine and dibromoethane, using ether as a solvent at a temperature in the range of 0-65° C., to obtain the Grignard reagent of the formula IIb; and
[0112] vi. Isolating the Grignard reagent of formula IIb
[0113] Unlike the prior art where reduction in step (i) to obtain compound of formula 4 is effected in homogeneous phase using water miscible solvent, in the process of the present invention, the reduction is carried out using aqueous hydrosulphite, in alkaline medium in the presence of a water immiscible organic solvent, separating the organic phase, and evaporating to obtain a concentrated residue, to which was added a hydrocarbon solvent to precipitate out compound of formula 4 which thereby increases the yield of the reduced product of the formula 4 substantially (to about 96% as compared to about 50% as per the prior art process).
[0114] According to the improved process of the present invention, the brominated product of formula 13 was isolated by precipitating out the solid in presence of a hydrocarbon solvent. The process described above increases the yield of the brominated compound (to about 96% as compared to 75% as per the prior art process).
[0115] In the modified process of the present invention the alkylation is carried out in the presence of a base sodium hydride in an inexpensive hydrocarbon solvent, or nonhazardous sodium alkoxide, in an inexpensive solvent like alcohol. Thereby making the process economical as compared to prior art where sodium hydride is used in presence of N,N dimethyl formamide which is an expensive solvent.
[0116] The bromo compound of formula 14a is reacted with magnesium in the presence of ether selected from diethylether, diisopropyl ether, tetrahydrofuran, at a temperature in the range of 0-65° C., to provide Grignard reagent of the formula IIb having — 92% purity.
[0117] According to yet another embodiment of the present invention, there is provided an improved process for the preparation of the Grignard reagent of the formula IIc as shown in Scheme 11
[0000]
[0118] which comprises,
[0119] (i) Reducing 2,3 dimethoxy-5-methyl 1,4 benzoquinone (CoQ 0 ) of the formula 2
[0000]
[0000] with aqueous sodium hydrosulphite, in alkaline medium, in the presence of a water immiscible organic solvent, separating the organic phase and evaporating the organic phase to obtain a concentrated residue, to which was added a hydrocarbon solvent to precipitate compound of formula 4;
[0000]
[0120] ii. Alkylating the compound of the formula 4, with alkyl sulphate by known method to obtain 2,3,4,5 tetramethoxy toluene compound of formula 4b
[0000]
[0121] iii. Brominating the resulting compound of the formula 4b with bromine in chlorinated hydrocarbon solvent at a temperature in the range of 0-25° C.,
[0122] iv Quenching the resultant reaction mixture in step (iii) in aqueous medium to obtain aqueous and organic phase and separating the organic phase, evaporating the organic phase to obtain a concentrated residue to which was added a hydrocarbon solvent to precipitate out 2,3,4,5 tetramethoxy 6-bromo toluene of the formula 14b
[0000]
[0123] v. Reacting the compound of the formula 14b obtained in step (iv) with magnesium in presence of iodine and dibromoethane, using ether as a solvent at a temperature in the range of 0-65° C., to obtain the Grignard reagent of the formula IIc, and
[0000]
[0124] vi. isolating the Grignard reagent of formula IIc.
[0125] Unlike the prior art where reduction in step (i) to obtain compound of formula 4 is effected in homogeneous phase using water miscible solvent, in the process of the present invention, the reduction is carried out using aqueous hydrosulphite, in alkaline medium in the presence of a water immiscible organic solvent, separating the organic phase, and evaporating to obtain a concentrated residue, to which was added a hydrocarbon solvent to precipitate out compound of formula 4 which thereby increases the yield of the reduced product of the formula 4 substantially (to about 96% as compared to about 50% as per the prior art process).
[0126] According to the improved process of the present invention, the brominated product compound of formula 14b was isolated by precipitating out the solid in presence of a hydrocarbon solvent. The process described above increases the yield of the brominated compound (to about 96% as compared to 75% as per the prior art process).
[0127] In the above mentioned process the purity of 2,3,4,5 tetramethoxy 6 methyl bromo benzene of the formula 14b is enhanced when formed by first alkylation of 2,3 dimethoxy 5 methyl 1,4 hydroquinone of the formula 2 , to form 2,3,4,5 tetramethoxy toluene compound of formula 4b which can be purified easily by vacuum distillation.
[0128] In a preferred embodiment of the present invention the various steps in the processes described above may be carried out as follows,
[0129] Reduction of 2,3-dimethoxy 5 methyl 1,4 benzoquinone, CoQ 0 of the formula 2, may be carried out by with sodium hydrosulphite in neutral or alkaline medium, preferably alkaline medium more preferably sodium hydroxide by dissolving CoQ 0 in a water immiscible organic solvent like ether, aromatic hydrocarbons, chlorinated hydrocarbons more preferably chlorinated hydrocarbons like methylene chloride, ethylene chloride, preferably methylene chloride. Thus the reaction may be carried out in biphase, at a temperature in the range of 0° C. to 30° C. preferably, 10 to 20° C. Isolation of 2,3-dimethoxy-5-methyl-1,4-hydroquinone compound of the formula 4, thus formed, may be carried out by acidifying the above reaction mixture, separating the organic phase and concentrating the organic phase. The concentrated organic phase may be added to aliphatic or aromatic hydrocarbon solvent like hexane, heptane, petroleum ether, preferably heptane to precipitate and filter the compound of formula 4.
[0130] Bromination of 2,3-dimethoxy-5-methyl-1,4-hydroquinone compound of formula 4, may be carried out with bromine in the presence of a chlorinated hydrocarbon solvent selected from methylene chloride and ethylenechloride at a temperature in the range of 0 to 30° C. preferably 10 to 20° C. Isolation of the brominated compound 2,3-dimethoxy-5-methyl-6-bromo-1,4-hydroquinone of formula 13 thus formed, may be carried out by quenching the resulting reaction mixture in aqueous medium, separating and concentrating the organic phase. The concentrated liquid may be added to a hydrocarbon solvent preferably heptane to precipitate and filter 2,3-dimethoxy-5-methyl-6-bromo-1,4-hydroquinone of formula 13.
[0131] Alkylation of 2,3-dimethoxy-5-methyl-6-bromo1,4-hydroquinone of the formula 13 may be carried out with methoxy ethoxy methyl chloride in the presence of metal hydride in aromatic hydrocarbons preferably toluene or an alkali metal alkoxide base selected from sodium methoxide, sodium ethoxide preferably sodium methoxide, in alcohol, at a temperature in the range of −30° C. to 30° C. preferably 15 to 25° C. 2,3-dimethoxy-5-methyl-6-bromo-1,4-hydroquinone methoxyethoxymethyl ether compound of formula 14a thus formed, may be isolated by quenching the reaction mixture in alcohol or aqueous medium, extracting in solvent selected from ether, aromatic hydrocarbon, chlorinated hydrocarbons preferably methylene dichloride, and concentrating the solvent.
[0132] 2,3-Dimethoxy-5-methyl-6-bromo-1,4-hydroquinone bismethoxyethoxymathyl ether of formula 14a, 2,3,4,5-tetramethoxy-6-methyl-bromo benzene compound of formula 14b or 2,3,4 trimethoxy-5-bromo-6-methyl phenol compound of formula 16 may be converted to the Grignard reagent, as given in literature.
[0133] 2,3-Dimethoxy-5-methyl-1,4-hydroquinone compound of the formula 4 may be alkylated using dimethylsulphate in acetone or in aqueous medium or in presence of alkali, preferably in aqueous medium in presence of alkali. The resulting product 2,3,4,5 tetramethoxy toluene of formula 4b, may be isolated by extracting in solvent and distilling out the solvent. The resultant residue may be distilled under vacuum at 0.2-10 mm Hg, preferably 0.5-0.8 mm Hg, to obtain the distilled 2,3,4,5 tetramethoxy toluene of formula 4b in more than 96% HPLC purity.
[0134] 2,3,4,5-tetramethoxy toluene of formula 4b may be brominated as given above to form 2,3,4,5-tetramethoxy-6-methyl bromo benzene of formula 14b.
[0135] The coupling of the Grignard reagents of the formula II with solanesyl bromide or decaprenyl bromide of the formula 3a_or 3b may be carried out in the presence of cuprous halide selected from cuprous chloride, cuprous bromide or cuprous iodide preferably cuprous bromide. Grignard reagent may be used in equivalent amount or excess of the solanesyl bromide or decaprenyl bromide in molar ratio of 1:1 to 1:4 preferably 1:1.1 to 1:2. The reaction may be carried out by adding the cuprous salt to the Grignard reagent and allowing to equilibrate for sufficient time. The copper salt is used in 1:1 to 1:0.1 molar ratio of the Grignard reagent. The solanesyl bromide or decaprenyl bromide of the formula 3a or 3b dissolved in a solvent, may be added to the Grignard reagent at temperature range of −25° C. to 25° C. preferably at room temperature. The solvent used may be the same as used for the Grignard reagent or different like aromatic hydrocarbon, aliphatic hydrocarbon like toluene, hexamethylphoshphoric triamide. The solvent for dissolving the solanesyl bromide or decaprenyl bromide may be preferably the same as used in Grignard reaction. The coupling of the Grignard reagent of the formula II, with solanesyl bromide or decaprenyl bromide of the formula 3a_or 3b may also be carried out by adding cuprous salt to the solution of solanesyl bromide or decaprenyl bromide of the formula 3a_or 3b_and the Grignard reagent of the formula II may be added to the above reaction mixture. The reaction may be monitored by HPLC and the rate of addition of the polyprenyl bromide solution may be adjusted with the rate of reaction. The reaction may be quenched in an aqueous medium in acidic or ammonium chloride solution preferably ammonium chloride solution, and the respective product of the formula IIIa or IIIb may be extracted in an water immiscible solvent, solvent evaporated, and the crude compound may be purified by column chromatography to obtain more than 96% pure compound.
[0136] Optional deprotection of IIIa (wherein at least one of R1 and R2 is —OCH 2 OCH 2 CH 2 OCH 3 ) or IIIb (wherein at least one of R1 and R2 is —OCH 2 OCH 2 CH 2 OCH 3 ) to obtain corresponding hydroquinone may be carried out by method given in literature, followed by oxidation to obtain the final product of compound of formula I 9 or I 10 .
[0137] The oxidation is carried out with cerric ammonium nitrate in acetonitrile as described in literature to obtain the final product of compound of formula I 9 or I 10 .
[0138] The details of the process are given in the Examples below which are provided for illustration only and therefore they should not be construed to limit the scope of the invention
EXAMPLE 1
Preparation of Grignard Reagent of 2,3 Dimethoxy-5-bromo-6-methyl 1,4 dimethoxyethoxy methyl ether Compound of Formula IIb
[0139] 2,3-Dimethoxy 5-methyl-1,4-benzoquinone of formula 2, (2.5 g) was dissolved in 7.5 ml of methylene dichloride and treated with sodium hydrosulphite (3.56 g) in an alkaline solution at 10-20° C. After 2 hours the reaction mixture was treated with conc. HCl (3.4 ml) to acidic pH. The reaction mixture was extracted with methylene dichloride and washed with water. The organic solvent was concentrated and poured in hexane. The precipitated solid was filtered to obtain 2.25 g of 2,3-dimethoxy-5-methyl-1,4-hydroquinone compound of formula 4. The solid was taken in methylene dichloride and treated with bromine (1.96 g) at 10 to 20° C. The reaction was quenched in water after 2 hours and extracted in methylene dichloride. The methylene dichloride was evaporated. The concentrated mass was added to hexane to precipitate out the solid of 2,3-dimethoxy-5-bromo-6-methyl-1,4-hydroquinone (3.06 g). The bromo compound was dissolved in toluene and treated with 1.024 g sodium hydride (60% suspension) in toluene at 0 to −5° C. Methoxyethoxy methyl chloride (3.17 g) was added at 5 to 10° C. The temperature was slowly raised to room temperature and the reaction was continued for 2 hrs. The reaction was quenched with methanol, followed by water and the toluene layer separated. The organic layer was distilled under vacuum to obtain 4.65 g of 2,3-dimethoxy-5-bromo-6-methyl-1,4-hydroquinone dimethoxyethoxy methyl ether compound of the formula 14a. The compound of formula 14a (4.65 g) was reacted with Magnesium (0.301 g) in tetrahydrofuran, in presence of a pinch of iodine at ambient temperature to form the Grignard reagent of 2,3 dimethoxy-5-bromo-6-methyl 1,4 dimethoxyethoxy methyl ether compound of formula IIb
EXAMPLE 2
Preparation of Grignard Reagent of 2,3 Dimethoxy-5-bromo-6-methyl 1,4 dimethoxyethoxy methyl ether Compound of Formula IIb
[0140] 2,3 dimethoxy 5-methyl 1,4 benzoquinone compound of formula 2 (2.5 g) was dissolved in 7.5 ml of methylene dichloride and treated with sodium hydrosulphite (3.56 g) in alkaline solution at 10-20° C. After 2 hours the reaction mixture was treated with conc. HCl 3.4 ml to acidic pH. The reaction mixture was extracted with methylene dichloride and washed with water. The organic solvent was concentrated and poured in hexane (10 ml). The precipitated solid was filtered to obtain 2.25 g of 2,3 dimethoxy 5 methyl 1,4 hydroquinone compound of formula 4. The solid was taken in methylene dichloride 15 ml and treated with bromine (1.96 g) at 10-20° C. The reaction was quenched in water after 2 hours and extracted in methylene dichloride. The methylene dichloride was evaporated. The concentrated mass was added to hexane to precipitate out the solid of 2,3 dimethoxy-5 bromo-6-methyl 1,4 hydroquinone (3.06 g). The bromo compound was dissolved in methanol and treated with sodium methoxide (1.5 g) at 5-10° C. Methoxyethoxy methyl chloride (3.17 g) was added at 5° C.-10° C., the temperature raised to room temperature and maintained for 8 hrs. The reaction was quenched in water and extracted in diisopropyl ether. The organic layer was distilled under vacuum to obtain 4.75 g of 2,3 Dimethoxy-5-bromo-6-methyl 1,4 di methoxyethoxy methyl ether compound of the formula 14a. The compound was reacted with magnesium (0.34 g) in tetrahydrofuran, in presence of a pinch of iodine at ambient temperature to form the Grignard reagent of 2,3 dimethoxy-5-bromo-6-methyl 1,4 dimethoxyethoxy methyl ether of the formula IIb .
EXAMPLE 3
Preparation of Grignard Reagent of 2,3,4,5 tetramethoxy-6-methyl-bromobenzene Compound of Formula IIc
[0141] 2,3dimethoxy-5-methyl 1,4 benzoquinone compound of formula 2 , 2.5 g was dissolved in 7.5 ml of methylene dichloride and treated with sodium hydrosulphite (3.56 g) in alkaline solution at 10-20° C. After 2 hours the reaction mixture was treated with conc. HCl (3.4 ml) to acidic pH. The reaction mixture was extracted with methylene dichloride and washed with water. The organic solvent was concentrated and poured in hexane. The precipitated solid was filtered to obtain 2.25 g. of 2,3 dimethoxy 5 methyl 1,4 hydroquinone compound of formula 4. The solid was taken in alkaline solution and dimethyl sulphate (5.75 g) was added at 40-50° C. The reaction mixture was quenched after 4 hours in water and extracted in methylene dichloride. The solvent was evaporated and the crude obtained was distilled under vacuum at 80° C. at 0.5-1.0 mm Hg to obtain 2.33 g of 2,3,4,5-tetramethoxy toluene. The compound was taken in methylene dichloride (15 ml) and treated with bromine (1.75 g) at 10-20° C. The reaction was quenched in water after 2 hours and extracted in methylene dichloride. The methylene dichloride was evaporated. The concentrated mass was added to hexane to precipitate out the solid of 2,3,4,5-tetramethoxy-6-methyl bromobenzene (3.03 g) of formula 14b. The compound of formula 14b was reacted with magnesium (0.30 g) in tetrahydrofuran, at ambient temperature, in presence of a pinch of iodine to form the Grignard reagent 2,3,4,5-tetramethoxy-6-methyl bromobenzene of formula IIc .
EXAMPLE 4
Preparation of Grignard Reagent of 2,3,4,5 tetramethoxy-6-methyl-bromobenzene Compound of Formula IIc
[0142] 2,3-dimethoxy 5-methyl-1,4-benzoquinone of formula 2 , (2.5 g) was dissolved in 7.5 ml of methylene dichloride and treated with sodium hydrosulphite (3.56 g) in alkaline solution at 10-20° C. After 2 hours the reaction mixture was treated with conc. HCl (3.4 ml) to acidic pH. The reaction mixture was extracted with methylene dichloride and washed with water. The organic solvent was concentrated and poured in hexane. The precipitated solid was filtered to obtain 2.25 g of 2,3-dimethoxy-5-methyl-1,4-hydroquinone of formula 4. The solid was taken in acetone, potassium carbonate (6.3 g) and dimethyl sulphate (5.75) g were added at 40-50° C. The reaction mixture was quenched after 4 hours in water and extracted in methylene dichloride. The solvent was evaporated and the crude obtained was distilled under vacuum at 80° C. at 0.5-1.0 mm Hg to obtain 2.33 g of 2,3,4,5-tetramethoxy toluene. The compound was taken in methylene dichloride (15 ml) and treated with bromine (1.75 g) at 10-20° C. The reaction was quenched in water after 2 hours and extracted in methylene dichloride. The methylene dichloride was evaporated. The concentrated mass was added to hexane to precipitate out the solid of 2,3,4,5-tetramethoxy-6-methyl-bromobenzene (3.03 g), compound of formula 14b. The compound 14b was reacted with magnesium (0.30 g) in tetrahydrofuran, at ambient temperature, in presence of a pinch of iodine to form the Grignard reagent of 2,3,4,5 tetramethoxy-6-methyl bromobenzene compound of the formula IIc.
EXAMPLE-5
Preparation of Novel Grignard Reagent of 2,3,4-trimethoxy-5-bromo-6-methyl-hydroquinone-1-methoxyethoxylmethyl ether of the Formula IIa
[0143] 2,3,4 trimethoxy-6-methyl-phenol compound of formula 15, (2.42 g) was taken in methylene dichloride 15 ml and treated with bromine 1.96 g at 10-20° C. The reaction was quenched in water after 2 hours and extracted in methylene dichloride. The methylene chloride layer was evaporated. The concentrated mass was added to hexane to precipitate out the solid of 2,3,4 trimethoxy-5 bromo-6-methyl-phenol (3.22 g) of formula 16. The bromo phenol of formula 16 was dissolved in toluene and treated with 0.513 g sodium hydride (60% suspension) in toluene at 0 to −5° C. Methoxyethoxy methyl chloride (1.59 g) was added at 5 to 10° C. The temperature was slowly raised to room temperature and maintained for 2 hrs. The reaction was quenched in water and the toluene layer separated. The organic layer was distilled under vacuum to obtain 4.03 g of 2,3,4-trimethoxy-5-bromo-6-methyl-hydroquinone-1-methoxyethoxylmethyl ether compound of the formula 17. The compound of formula 17 was reacted with magnesium (0.35 g) in tetrahydrofuran, at ambient temperature, in presence of a pinch of iodine, to form the Grignard reagent of 2,3,4-trimethoxy-5-bromo-6-methyl-hydroquinone-1-methoxyethoxylmethyl ether of the formula IIa.
[0144] 1 H-NMR (300 MHz, CDCl 3 , 2.33 (3H, —CH 3 ), 3.38-3.94 (18H, —OCH 2 O—, —CH 2 CH 2 O—, —OCH 3 )
EXAMPLE 6
Preparation of Novel Grignard Reagent of 2,3,4-trimethoxy-5-bromo-6-methyl-hydroquinone-1-methoxyethoxylmethyl ether of the Formula IIa.
[0145] 2,3,4 trimethoxy-6-methyl-phenol compound of formula 15, 2.42 g was taken in methylene dichloride (15 ml) and treated with bromine (1.96 g) at 10 to 20° C. The reaction was quenched in water after 2 hours and extracted in methylene dichloride. The methylene chloride layer was evaporated. The concentrated mass was added to hexane to precipitate out the solid of 2,3,4 trimethoxy-5 bromo-6-methyl-phenol (3.22 g) of formula 16. The bromo phenol of formula 16 was dissolved in methanol and treated with sodium methoxide (0.75 g) at 5-10° C. Methoxyethoxy methyl chloride (1.59 g) was added at 5° C. to 10° C. and the temperature was raised to room temperature and maintained for 8 hrs. The reaction was quenched in water and extracted in diisopropyl ether. The solvent was distilled under vacuum to obtain 4.0 g of 2,3,4-trimethoxy-5-bromo-6-methyl-hydroquinone-1-methoxyethoxylmethyl ether compound of the formula 17. The compound of formula 17 was reacted with magnesium (0.35 g) in tetrahydrofuran, at ambient temperature, in presence of a pinch of iodine, to form the Grignard reagent of 2,3,4-trimethoxy-5-bromo-6-methyl-hydroquinone-1-methoxy-ethoxylmethyl ether of the formula IIa .
[0146] 1 H-NMR (300 MHz, CDCl 3 , 2.33 (3H, —CH 3 ), 3.38-3.94 (18H, —OCH 2 O—, —OCH 2 CH 2 O—, —OCH 3 )
EXAMPLE 7
Preparation of Compound of the Formula IIIa (Where R1 and R2=—OCH 2 OCH 2 CH 2 OCH 3 )
[0147] The Grignard reagent of 2,3 Dimethoxy-5-bromo-6-methyl 1,4 hydroquinone dimethoxyethoxy methyl ether of the formula IIb prepared by the process described in Example 1, was cooled to 0-5° C. Cuprous bromide (0.65 g) was added to the Grignard solution of formula IIb, stirred at room temperature for 1 hour, followed by dropwise addition of a solution of solanesyl bromide in tetrahydrofuran (4 g in 25 ml tetrahydrofuran). The reaction mixture was stirred for four hours and the mixture quenched in 5% ammonium chloride solution and extracted in diethyl ether. The solvent was dried over anhydrous sodium sulphate and evaporated to give 7.2 g of crude, which was purified by column chromatography to give 4.4 g of the pure title compound
EXAMPLE 8
Preparation of Compound of the Formula IIIa (Where R1 and R2=—OCH 2 OCH 2 CH 2 OCH 3 )
[0148] The Grignard reagent of 2,3 Dimethoxy-5-bromo-6-methyl 1,4 dimethoxyethoxy methyl ether compound of the formula IIb prepared by the process described in Example 1, was slowly added to a solution of solanesyl bromide in tetrahydrofuran (4 g in 25 ml tetrahydrofuran) in presence of cuprous bromide (0.65 g). The reaction was continued for four hours at room temperature and the mixture quenched in 5% ammonium chloride solution and extracted in diethyl ether. The solvent was dried over anhydrous sodium sulphate and evaporated to give 7.8 g of crude, which was purified by column chromatography to give 4.0 g of the pure title compound
EXAMPLE 9
Preparation of Compound of the Formula IIIa (Where R1 and R2=—OMe)
[0149] The Grignard reagent of 2,3,4,5 tetramethoxy-6-methyl bromobenzene compound of the formula II c, prepared by the process described in Example 3, was cooled at 0-5° C. Cuprous bromide (0.75 g) was added to the Grignard solution of formula IIc , stirred at room temperature for 1 hour, followed by dropwise addition of a solution of solanesyl bromide in tetrahydrofuran (4 g in 25 ml tetrahydrofuran). The reaction mixture was stirred for four hours and the mixture quenched in 5% ammonium chloride solution and extracted in diethyl ether. The solvent was dried over anhydrous sodium sulphate and evaporated to give 7.0 g of crude, which was purified by column chromatography to give 3.78 g of the pure title compound.
EXAMPLE 10
Preparation of Compound of the Formula IIIa (Where R1 and R2=—OMe)
[0150] The Grignard reagent of 2,3,4,5 tetramethoxy-6-methyl bromobenzene compound of the formula IIc, prepared by the process described in Example 3, was slowly added to a solution of solanesyl bromide in tetrahydrofuran (4 g in 25 ml tetrahydrofuran) in presence of cuprous bromide (0.75 g). The reaction was continued for four hours at room temperature and the mixture quenched in 5% ammonium chloride solution and extracted in diethyl ether. The solvent was dried over anhydrous sodium sulphate and evaporated to give 7.0 g of crude, which was purified by column chromatography to give 3.36 g of the pure title compound.
EXAMPLE 11
Preparation of Compound of the Formula IIIa (Where R1=—OCH 2 OCH 2 CH 2 OCH 3 and R2=—OMe)
[0151] The Grignard reagent of 2,3,4-trimethoxy-5-bromo-6-methyl-hydroquinone-1-methoxy-ethoxylmethyl ether of the formula IIa prepared by the process described in Example 5, was cooled to 0-5° C. Cuprous bromide (0.79 g) was added to the Grignard solution of formula IIa, stirred at room temperature for 1 hour, followed by dropwise addition of a solution of solanesyl bromide in tetrahydrofuran (4 g in 25 ml tetrahydrofuran). The reaction mixture was stirred for four hours and the mixture quenched in 5% ammonium chloride solution and extracted in diethyl ether. The solvent was dried over anhydrous sodium sulphate and evaporated to give 7.2 g of crude, which was purified by column chromatography to give 4 g of the pure title compound.
EXAMPLE 12
Preparation of Compound of the Formula IIIa (Where R1=—OCH 2 OCH 2 CH 2 OCH 3 and R2=—OMe)
[0152] The Grignard reagent of 2,3,4-trimethoxy-5-bromo-6-methylhydroquinone-1-methoxy-ethoxylmethyl ether of the formula IIa prepared by the process described in Example 5, was slowly added to a solution of solanesyl bromide in tetrahydrofuran (4 g in 25 ml tetrahydrofuran) in presence of cuprous bromide (0.79 g). The reaction was continued for four hours at room temperature and the mixture quenched in 5% ammonium chloride solution and extracted in diethyl ether. The solvent was dried over anhydrous sodium sulphate and evaporated to give 7.8 g of crude, which was purified by column chromatography to give 3.68 g of the pure title compound.
EXAMPLE 13
Preparation of Compound of the Formula IIIb (Where R1 and R2=—OCH 2 OCH 2 CH 2 OCH 3 )
[0153] The Grignard reagent of 2,3 Dimethoxy-5-bromo-6-methyl 1,4 hydroquinone dimethoxy-ethoxy methyl ether of the formula IIb prepared by the process described in Example 1, was cooled to 0-5° C. Cuprous bromide (0.65 g) was added to the Grignard solution of formula IIb, stirred at room temperature for 1 hour, followed by dropwise addition of a solution of decaprenyl bromide in tetrahydrofuran (4.39 g in 25 ml tetrahydrofuran). The reaction mixture was stirred for four hours and the mixture quenched in 5% ammonium chloride solution and extracted in diethyl ether. The solvent was dried over anhydrous sodium sulphate and evaporated to give 7.2 g of crude, which was purified by column chromatography to give 4.39 g of the pure title compound
EXAMPLE 14
Preparation of Compound of the Formula IIIb (Where R1 and R2=—OCH 2 OCH 2 CH 2 OCH 3 )
[0154] The Grignard reagent of 2,3 Dimethoxy-5bromo-6-methyl 1,4 dimethoxyethoxy methyl ether compound of the formula IIb prepared by the process described in Example 1, was slowly added to a solution of decaprenyl bromide in tetrahydrofuran (4.39 g in 25 ml tetrahydrofuran) in presence of cuprous bromide (0.65 g). The reaction was continued for four hours at room temperature and the mixture quenched in 5% ammonium chloride solution and extracted in diethyl ether. The solvent was dried over anhydrous sodium sulphate and evaporated to give 7.8 g of crude, which was purified by column chromatography to give 3.88 g of the pure title compound.
EXAMPLE 15
Preparation of Compound of the Formula IIIb (Where R1 and R2=—OMe)
[0155] The Grignard reagent of 2,3,4,5 tetramethoxy-6-methyl bromobenzene compound of the formula IIc, prepared by the process described in Example 3, was cooled to 0-5° C. Cuprous bromide (0.75 g) was added to the Grignard solution of formula IIc, stirred at room temperature for 1 hour, followed by dropwise addition of a solution of decaprenyl bromide in tetrahydrofuran (4.39 g in 25 ml tetrahydrofuran). The reaction mixture was stirred for four hours and the mixture quenched in 5% ammonium chloride solution and extracted in diethyl ether. The solvent was dried over anhydrous sodium sulphate and evaporated to give 7.0 g of crude, which was purified by column chromatography to give 4.11 g of the pure title compound.
EXAMPLE 16
Preparation of Compound of the Formula IIIb (Where R1 and R2=—OMe)
[0156] The Grignard reagent of 2,3,4,5 tetramethoxy-6-methyl bromobenzene compound of the formula IIc, prepared by the process described in Example 3, was slowly added to a solution of decaprenyl bromide in tetrahydrofuran (4.39 g in 25 ml tetrahydrofuran) in presence of cuprous bromide (0.75 g). The reaction was continued for four hours at room temperature and the mixture quenched in 5% ammonium chloride solution and extracted in diethyl ether. The solvent was dried over anhydrous sodium sulphate and evaporated to give 7.0 g of crude, which was purified by column chromatography to give 3.65 g of the pure title compound.
EXAMPLE 17
Preparation of Compound of the Formula IIIb (Where R1=—OCH 2 OCH 2 CH 2 OCH 3 and R2=—OMe)
[0157] The Grignard reagent of 2,3,4-trimethoxy-5-bromo-6-methyl-hydroquinone-1-methoxyethoxylmethyl ether of the formula IIa prepared by the process described in Example 5, was cooled to 0-5° C. Cuprous bromide (0.79 g) was added to the Grignard solution of formula IIa, stirred at room temperature for 1 hour, followed by dropwise addition of a solution of decaprenyl bromide in tetrahydrofuran (4.39 g in 25 ml tetrahydrofuran). The reaction mixture was stirred for four hours and the mixture quenched in 5% ammonium chloride solution and extracted in diethyl ether. The solvent was dried over anhydrous sodium sulphate and evaporated to give 7.2 g of crude, which was purified by column chromatography to give 4.45 g of the pure title compound.
EXAMPLE 18
Preparation of Compound of the Formula IIIb (Where R1=—OCH 2 OCH 2 CH 2 OCH 3 and R2=—OMe)
[0158] The Grignard reagent of 2,3,4-trimethoxy-5-bromo-6-methyl-hydroquinone-1-methoxyethoxylmethyl ether of the formula IIa prepared by the process described in Example 5, was slowly added to a solution of decaprenyl bromide in tetrahydrofuran (4.39 g in 25 ml tetrahydrofuran) in presence of cuprous bromide (0.79 g). The reaction was continued for four hours at room temperature and the mixture quenched in 5% ammonium chloride solution and extracted in diethyl ether. The solvent was dried over anhydrous sodium sulphate and evaporated to give 7.8 g of crude, which was purified by column chromatography to give 3.95 g of the pure title compound.
EXAMPLE 19
Preparation of CoQ 9 of Formula I 9
[0159] The compound of the formula IIIa (4.4 g) prepared by the process described_in Example 7 was treated with 48% HBr solution (0.22 ml), in presence of isopropanol for 4 hours. The isopropanol was distilled off and the residue was taken in n -hexane. The hexane solution was washed with water dried over anhydrous sodium sulphate and distilled under vacuum to obtain 3.56 g of the residue of CoQ 9 dihydroquinone. The dihydroquinone was oxidized with ferric chloride (2.56 g) in 1 ml water, in presence of isopropanol at room temperature for 3 hours. The reaction was quenched in water and extracted in hexane. The hexane layer was dried over anhydrous sodium sulphate and evaporated to give crude CoQ 9 . The crude CoQ 9 was crystallized in ethanol, at 10-15° C., to obtain 2.67 g of pure compound, with overall yield from solanesyl bromide as 58%.
EXAMPLE 20
Preparation of CoQ 9 of Formula I 9
[0160] The compound of the formula IIIa (3.78 g) prepared by the process described in Example 9 was taken in 48 ml of methylene dichloride and treated with a solution 4 g of cerric ammonium nitrate in 25 ml of acetonitrile and 25 ml of water at 0° C. The reaction mixture was quenched in water and extracted in methylene dichloride solution. The methylene dichloride was concentrated under vacuum to obtain crude CoQ 9 . The crude CoQ 9 was purified by column chromatography and crystallized in ethanol, at 10-15° C. to obtain 2.34 g of pure compound, with overall yield from solanesyl bromide as 51%.
EXAMPLE 21
Preparation of CoQ 9 of Formula I 9
[0161] The compound of the formula IIIa (4.0 g) prepared by the process described in Example 11 was treated with 48% HBr solution (0.22 ml), in presence of isopropanol for 4 hours. The isopropanol was distilled off and the residue was taken in n-hexane. The hexane solution was washed with water dried over anhydrous sodium sulphate and distilled under vacuum to obtain 3.24 g of the residue of CoQ 9 hydroquinone. The hydroquinone was oxidized with ferric chloride (2.56 g) in 1 ml water, in presence of isopropanol at room temperature for 3 hours. The reaction was quenched in water and extracted in hexane. The hexane layer was dried over anhydrous sodium sulphate and evaporated to give crude CoQ 9 . The crude CoQ 9 was crystallized in ethanol, at 10-15° C., to obtain 2.30 g of pure compound, with overall yield from solanesyl bromide as 50%.
EXAMPLE 22
Preparation of CoQ 10 of Formula I 10
[0162] The compound of the formula IIIb (4.39 g) prepared by the process described in Example 13 was treated with 48% HBr solution (0.22 ml), in presence of isopropanol for 4 hours. The isopropanol was distilled off and the residue was taken in n-hexane. The hexane solution was washed with water dried over anhydrous sodium sulphate and distilled under vacuum to obtain 3.56 g of the residue of CoQ 10 dihydroquinone. The dihydroquinone was oxidized with ferric chloride (2.56 g) in 1 ml water, in presence of isopropanol at room temperature for 3 hours. The reaction was quenched in water and extracted in hexane. The hexane layer was dried over anhydrous sodium sulphate and evaporated to give crude CoQ 10 . The crude CoQ 10 was crystallized in ethanol, at 10-15° C., to obtain 2.53 g of pure compound, with overall yield from decaprenyl bromide as 51%.
EXAMPLE 23
Preparation of CoQ 10 of Formula I 10
[0163] The compound of the formula IIIb_(4.11 g) prepared by the process described in Example 15 was taken in 48 ml of methylene dichloride and treated with a solution 4 g of cerric ammonium nitrate in 25 ml of acetonitrile and 25 ml of water at 0° C. The reaction mixture was quenched in water and extracted in methylene dichloride solution. The methylene dichloride was concentrated under vacuum to obtain crude CoQ 10 . The crude CoQ 10 was purified by column chromatography and crystallized in ethanol, at 10-15° C., to obtain 2.54 g of pure compound, with overall yield from decaprenyl bromide as 51.0%.
EXAMPLE 24
Preparation of CoQ 10 of Formula
[0164] The compound of the formula IIIb (4.45 g) prepared by the process described in Example 17 was treated with 48% HBr solution (0.22 ml), in presence of isopropanol for 4 hours. The isopropanol was distilled off and the residue was taken in n-hexane. The hexane solution was washed with water dried over anhydrous sodium sulphate and distilled under vacuum to obtain 3.89 g of the residue of CoQ 10 hydroquinone. The hydroquinone residue was oxidized with ferric chloride (2.56 g) in 1 ml water, in presence of isopropanol at room temperature for 3 hours. The reaction was quenched in water and extracted in hexane. The hexane layer was dried over anhydrous sodium sulphate and evaporated to give crude CoQ 10 . The crude CoQ 10 was crystallized in ethanol, at 10-15° C., to obtain 2.77 g of pure compound, with overall yield from decaprenyl bromide as 55.8%.
ADVANTAGES OF THE INVENTION
[0165] 1. Provides Straight forward coupling of the “benzoquinone nucleus” with the “polyprenyl side chain” for the preparation of the coenzymes Q namely, CoQ 9 and CoQ 10 .
[0166] 2 Provides stereoselective coupling reaction for preparation of coenzymes Q namely, CoQ 9 and CoQ 10 by simple Grignard reaction, maintaining the geometrical isomer of the double bond. Controlling cis isomer in the reaction decreases purification loss incurred in removing unwanted cis isomer, thereby making the process cost effective.
[0167] 3. Provides a novel Grignard reagent compound of formula IIa and its preparation, which is useful for the preparation of Coenzymes namely, CoQ 9 and CoQ 10 .
[0168] 4. Provides novel intermediates compounds of formula III useful for the preparation of CoQ 9 .
[0169] 5. Provides novel intermediate compounds of formula III useful for the preparation of CoQ 10 .
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The present invention relates to novel intermediates for the preparation of coenzymes, processes for the preparation of the intermediates and an improved process for the preparation of Coenzymes. The present invention particularly relates to an improved process for the preparation of Coenzyme Q, more particularly for Conenzyme Q 9 and Coenzyme Q 10 . Still more particularly this invention relates to regio and stereo controlled process for the preparation of Coenzyme Q 9 and Coenzyme Q 10 of the formula I
where n=9 (Coenzyme CoQ 9 ), and where n=10. (Coenzyme CoQ 10 )
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FIELD OF THE INVENTION
This invention relates to grain cleaning and aeration and more particularly to an apparatus method for cleaning, distributing and aerating grain.
BACKGROUND OF THE INVENTION
Harvested grain crops, such as corn or the like, are usually stored and the moisture content is typically controlled by drying When the grain is sold, the price of the grain is effected by the amounts of fines in the grain. For example, the Federal Standards allows a maximum of 3% fines (broken corn and foreign material) in corn for No. 2 grade corn, and a maximum of 2% for No. 1 corn. Aeration of the grain during storage reduces the occurrence of mold damage.
A grain cleaner and distributor apparatus is disclosed in my U.S. Pat. No. 2,750,997 and this apparatus is effective in cleaning grain or similar material delivered to a storage structure. However, the distribution of the grain with this apparatus cannot be closely controlled because the grain receiver is non-adjustable. I have provided a novel receiver for this grain and distributing apparatus which permits controlled distribution of the grain into the storage structure. I have also developed a method of cleaning, distributing and aerating the grain with this improved apparatus.
SUMMARY OF THE INVENTION
It is an object of this invention to provide an improved grain cleaner and aerating apparatus which has a grain receiving control device for effectively controlling the distribution of the grain into the storage structure.
Another object of this invention is to provide a novel method of cleaning and distributing the grain by using the improved apparatus in one mode of operation and thereafter engaging a concavity at the top of the mound of grain in the storage structure with the apparatus in an inverted condition to aerate grain.
FIGURES OF THE DRAWING
FIG. 1 is a side view partly in elevation and partly in section illustrating the improved grain spreading and cleaning apparatus mounted in a storage structure,
FIG. 2 is a cross-sectional view of grain receiving components illustrating details of construction thereof,
FIG. 3 is a perspective view of the grain receiving components illustrated in FIG. 3,
FIG. 4 is a perspective view of the blade used to construct the control spout,
FIG. 5 is a diagrammatic view illustrating the improved grain cleaning and distributing apparatus as it is used to clean and distribute the grain;
FIG. 6 is a diagrammatic view similar to FIG. 2 but illustrating the apparatus in an adjusted mode of operation for aerating the grain.
FIG. 7 is a modified form of the control spout device; and
FIG. 8 is a cross-sectional view taken approximately along line 8--8 of FIG. 1 and looking in the direction of the arrows.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring now to the drawings and more specifically to FIG. 1, it will be seen that one embodiment of the improved grain cleaning and distributing apparatus, designated generally by the reference numeral 10, is thereshown. The apparatus 10 is mounted in a conventional storage structure S for grain or the like adjacent the opening located at the top of the storage structure. It is again pointed out that the storage structure may be any of the conventional kinds including bins, truck bodies or similar structures for use in the storage and/or delivery of grain The apparatus 10 is mounted or suspended adjacent the opening 0 to permit grain delivered to the storage structure to be received, cleaned and distributed by the apparatus.
The apparatus 10 includes a cylindrical grain receiving member 11 having a lower wall 12 with a centrally located opening 13 therein. A pair of elongate vertically disposed tubular elements 14 have their upper end rigidly secured to the lower surface of the lower wall 12 and depend therefrom. A tray-shaped distributor member 15 is positioned below the cylindrical grain receiving member 11 and has a lower wall 16 integral with an upstanding annular wall 17. The distributor member 15 is provided with an out-turned flange 18 which is integral with the annular wall 17. The distributor member 15 is also provided with a pair of vertically disposed elongate rods 20, each telescopically engaging in one of the tubular elements 14. Each vertically tubular element 14 is provided with a vertically adjustable lock element 21 thereon to permit the distributor member to be vertically shifted relative to the grain receiving member 11. A control spout device 22 is adjustably mounted on the cylindrical grain receiving member and depends therefrom.
It is pointed out that the tubular members 14 could be shortened in length and secured to the distributor member 15 rather than grain receiving member 11. The rods 20, on the other hand, would be lengthened and secured to the distributor member 15 rather than the grain receiving member 11. Each of the tubular members 14 would be secured to the distributor member 15 in registering relation with openings in the lower wall 16. With this arrangement, the grain receiver member 11 may be collapsed downwardly on the distributor member 15 by lossening the lock elements 21 and urging the rod (extended in length) downwardly through the tubular members and opening in the distributor member.
The apparatus 10 also includes a frustro-conically shaped screen device 23 having an opening at its upper end. An upper bead or rim 24 is secured to the screen 23a of the screen device at the upper end opening. It will be noted that the upper opening is of a size to receive the tray-shaped distributor member 15 therein with the out-turned flange 18 thereof engaging the upper bead 24. The screen device is also provided with a lower annular bead or rim 25 which is secured to the screen 23a at its lower edge.
In some instances, it may be desirable to reinforce the screen 23a because of the load exerted on the surface thereof. Therefore, a plurality of straight reinforcing rods will extend between and be welded to upper rim 24 and leave rim 25 to reinforce the screen 23a.
A rigid imperforate funnel-shaped body 26 engages the lower edge portion of the screen device 22 and projects downwardly. The funnel-shaped body 26 has a tapered wall 27 that tapers downwardly and terminates in a lower end portion 28. The lower end portion 28 is provided with openings therein for connection to a motor mounting means. The U-shaped hanger 30 is secured to the lower end of an elongate rod 31 which has its upper threaded end projecting through an opening in the lower wall 16 of the distributor member by a wing nut 32.
A fan assembly 33 is secured to the lower cylindrical end portion 28 of the funnel-shaped body 26 and depends therefrom. The front assembly 33 includes an electric motor 34 which is secured to a fan housing 35, the housing having an upwardly facing inlet 36.
The motor mounting means includes a small funnel 37 which is secured to the lower end portion of the funnel-shaped body 26 by nut and bolt assemblies 37a. A circular mounting member 37b is secured to the lower end of the electric motor 34 and is provided with attachment straps 37c. The straps 37c extend upwardly at an angle with respect to the mounting member 37b and each strap has an opening therein. The straps are positioned against the inner surface of the funnel-shaped body 26 and are secured thereto by nut and bolt assemblies 37a. The electric motor is therefore mounted in vertical relation within the funnel-shaped body 26.
The fan housing 35 accommodates a fan therein which is driven by the output shaft (not shown) of the electric motor 34. The fan housing 35 is provided with an outlet 38 which is connected in communicating relation with one end of an elongate conduit 39. The conduit extends outwardly to the exterior and a suitable conductor 40 having a conventional bayonette type socket member is connected to a source of electrical power and to the electric motor 34 for operating the electric motor. The conductor 40 extends through registering openings in funnel 37 and the funnel-shaped body 26 as best seen in FIG. 1. When the electric motor 34 is energized, air will pass through the inlet 36 and will be discharged through the outlet 38 and into the conduit 39.
The operation of the apparatus 10 during the grain cleaning and distribution phase is substantially identical to that disclosed in my U.S. Pat. No. 4,750,997. Grain passes through the grain receiving member 11 and into the tray-shaped distributor member 15 where the grain is discharged outwardly upon the screen device 22. The openings in the screen device 23 are of a magnitude to prevent grain from passing therethrough but do allow the fines to pass therethrough.
When the fan assembly is energized, the fine material moving downwardly along the screen device will be subjected to a pressure differential and the fines material will be sucked through the screen into the funnel-shaped body 26 then into the fan housing while entrained in a stream of air. These fines will thereafter be discharged exteriorly of the storage structure through the conduit 39.
Since the electric motor 34 is positioned interiorly of the cleaning apparatus 10, the electric motor will be cooled by the air flowing downwardly through the funnel over the motor. Since the output shaft is facing downwardly, there is little if any chance of rainwater flowing into the motor (and the resultant shorting) in the event that the apparatus is accidentally exposed to rain. It is pointed out that the electric motor 34 may be positioned exteriorly of the apparatus 10 in the manner disclosed in my U.S. Pat. No. 4,750,997.
During the distribution and cleaning phase of the grain, it is desirable to have uniform distribution of the grain in the storage structure. Means are provided for permitting a more uniform distribution of the grain in the storage structure and this means includes the adjustable control spout 22. The adjustable control spout 22 includes a spout member 41 which is mounted on an adjustable mounting member 42. The spout member 41 is formed of flexible plastic material and is preferably formed from a rectangular blank of such material as illustrated in FIG. 4. The blank has a plurality of vertical slits 43 therein that extend from the bottom edge 45 towards but terminates short of the top edge 46 as best seen in FIG. 4. These slits provide the panel with a plurality of panel elements 44.
The adjustable mounting member is formed of a rigid ferrous material and includes a circular flat body 47 having a central opening 48 therein. The central opening 48 communicates with and is defined by a depending cylindrical flange 49. The mounting member is positioned within the grain receiving member 11 so that the circular flat body 47 engages the upper surface 12a of the lower wall 12 of the grain receiving member. The depending cylindrical flange 49 projects through the central opening 13 in the lower wall of the grain receiving member and the depending flange is engaged by the upper end portion of the spout member 41. An upper clamping collar 50 clamps the upper end portion of the spout member to the depending cylindrical flange 49. A lower adjustable clamping collar 51 extends around and clamps the lower end portion of the spout member 41.
The lower adjustable clamping collar 51 may be adjusted to restrict or enlarge the cross-sectional size of the lower end portion of the spout member and to thereby control the amount of grain discharged from the spout member into the distributor member 15. This can be easily accomplished by tightening or loosening the lower adjustable clamping collar 51. When the lower adjustable collar is tightened, the panel elements 44 are urged into over-lapping relation with each other in a progressive manner to thereby reduce the cross-sectional size of the lower end of the opening. When the lower adjustable clamping collar is loosened, the cross-sectional size of the spout will be enlarged.
It is also desirable to adjust the spout laterally relative to the grain receiving member 11 and relative to the distributor member 15. It will therefore be seen that the diameter of the circular flat body 47 of the mounting member 42 has a diameter less than the diameter of the grain receiving member 11. It will further be noted that the opening 13 in the lower wall 12 of the grain receiving member is also larger than the diameter defined by the exterior surface of the depending cylindrical flange 49. Therefore the mounting member 42 can be translated laterally in any direction relative to the lower wall 12 of the grain receiving member.
Means are provided for retaining the mounting member in an adjusted position. This means includes a plurality of arcuate shaped magnets 52. The magnets are disposed between the upper surface 12a of the lower wall 12 and the lower surface of the circular flat body 47. Since the mounting member 42 in the cylindrical grain receiving member are formed of ferrous material, the magnets 52 are attracted to both of these members and serve to hold the control spout device 21 in an adjusted position.
The unique design of the control spout device 21 permits the lumen type passage defined by the spout to be selectively varied at its lower end to control the amount of grain or other material being discharged therefrom into the distributor member 15. The control spout device may also be translated laterally in any direction to vary the position the material will be discharged into the distributor member 15. This allows an operator to adjust the distribution of the material as the storage structure is being filled.
Referring now to FIG. 7 a modified form adjustable control spout designated generally by the reference numeral 22a. The control spout 22a is substantially identical to that shown in FIG. 3 and includes slits 43a which define panels 44a. The essential difference in the embodiment of FIG. 7 with respect to the embodiment of FIG. 3 involves the clamping collar or element. In FIG. 7, the clamping element 51a comprises an elastic ring preferrably formed of a resilient elastic material including rubber. Each of the panels 44a is provided with a small retainer element 51b which is integral therewith and projects outwardly therefrom. The retainer elements 51b prevent elastic clamping ring 51a from slipping from the lower end of the control spout 22a.
When the storage structure is filled with the grain or similar material, the upper surface of the grain forms a shallow peak having a upwardly facing concaved depression located just below the apparatus 10 as shown in FIG. 5. This concave depression C in the grain conforms generally to the exterior configuration of the screen device 23 and the funnel shaped body 26. This upper profile of the fill storage structure is simply a characteristic of the distribution function of the apparatus 10.
After the storage structure has been filled, the operator may remove the apparatus from its suspended relation with the storage structure and may disconnect the hanger 30 from its engaged relation with the cylindrical lower end portion 28 of the funnel shaped body. This permits the cylindrical member 11, the tray-shaped distributor member 15 and the control spout 22 to be removed from the apparatus which may then be inverted to position the screen device in the concave depression C. The screen device will engage the surface of the grain defining the depression and the fan assembly will be positioned uppermost as illustrated in FIG. 6. The conduit 39, which is flexibly, may then be directed through an opening in the storage structure so that the outer end of the conduit is located exteriorly of the storage structure. When the fan motor 34 is energized to operate the fan, air will be pulled through the grain and through the screen device and will be directed to the exterior through the discharge conduit 39.
In the proposed embodiment, operation of the fan assembly motor 34 is made responsive to the temperature of the air passing upwardly through the grain. A temperature sensitive probe device 60 is electrically connected to the fan motor 34 by an electrical conductor 61. The probe device includes a control box 62 having an adjustment dial for preselecting an operating temperature level. The probe device also includes an elongate temperature sensitive probe 63. The probe 63 senses the temperature of the air and surrounding grain adjacent its lower tip. With this arrangement, the fan motor 34 will operate until the temperature of all the grain surrounding the lower end of the probe 63 falls below the selected temperature level which then opens the electrical circuit to the fan motor 34. Since the grain has been cleaned (all fines removed), aeration can be easily accomplished.
The probe device 60a can be moved to any selected position including suspected hot spots. As an alternative sensing method, the probe device 60a may be mounted in the conduit 39 immediately adjacent the discharge outlet 38 in the fan housing 35. This probe device is identical in all respects to that previously described except that the probe 63a is shorter in length than the probe 63. The temperature of the air drawn through the grain into the fan housing 35 will be sensed as it is discharged from the housing. When the temperature of this air stream falls below the prescribed level, the circuit to the fan motor will be opened.
It is also pointed out that a conventional timing control (not shown) may be provided which could be placed at a location remote from the apparatus and storage structure but in controlling relation with the fan motor circuit. The timing control could be selectively set to operate the fan motor for a predetermined period of time (for example, 15 to 60 minutes or longer) before opening the circuit to the fan motor.
Thus my novel improved apparatus permits the grain or similar material to be cleaned and distributed in a storage structure and thereafter aerated by placing the apparatus in a different mode of operation. Thus is will be seen that the apparatus 10 permits grain to be effectively cleaned, uniformly distributed and aerated during and immediately after loading.
Thus, it will be seen that I have provided a novel apparatus and method for cleaning grain as it is uniformly distributed into a storage structure and which is also operable to aerate the grain after loading.
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An improved apparatus for cleaning, distributing and aereating grain is mounted in a storage structure and includes a frustro-conical screen device secured symetrically to an imperforate funnel-shaped member. A fan assembly is secured to the funnel-shaped body and is provided with a conduit which extends to the exterior. An adjustable control spout permits uniform distribution of grain upon the screen device where the fine material passes through the apertures in the screen while the grain is discharged into the storage structure. After the cleaning and distribution of steps are completed, the apparatus will then be inverted to position the screen device in the concave crater of the grain pile while positioning the funnel shaped body and fan assembly uppermost. The fan assembly will be energized to aereate the grain and present damage due to mold or fungus.
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FIELD OF THE INVENTION
The present invention relates to surgical drainage devices used in draining fluids from the body, e.g. the pleural cavity, and is particularly concerned with an improved drainage apparatus which provides ready incremental control and indication of the applied suction pressure.
BACKGROUND OF THE INVENTION
It is essential for normal breathing that the space within the pleural cavity surrounding the lungs be free of liquid and be subject to a negative pressure so as to draw the lungs outwardly to fill this pleural cavity in order to permit proper breathing. Any invasion of the pleural cavity such as caused by lung surgery or foreign objects which pierce the rib cage or such as occur, for example, where the patient has pleurisy, generates fluids in the pleural cavity which tend to obstruct normal breathing by preventing full expansion of the lungs. It is necessary to provide a device which can remove these fluids from the pleural cavity and at the same time ensure that the desired degree of negative pressure imposed by the suction control chamber is approximately maintained within the pleural cavity so that the lung maintains its maximal expansion.
Two of the basic types of apparatus which have been used for this purpose are shown, for example, in U.S. Pat. Nos. 3,363,626 and 3,363,627, and in pending U.S. application Ser. No. 120,295 filed Feb. 11, 1980, which are herein incorporated by reference. The first of these apparatuses provides three chambers, one chamber comprising a collection chamber for collecting the fluids drained from the pleural cavity through a thoracotomy tube, a second chamber known as an underwater seal chamber which protects the pleural cavity from being subject to atmospheric pressure, and a third chamber known as a suction control chamber which serves to regulate the degree of negative pressure within the pleural cavity. The other of these apparatuses provides a collection chamber with an underwater seal chamber located at the upper end thereof adjacent the lower end of the thoracotomy tube. Secretions from the body cavity form the underwater seal and excess secretions thereafter overflow into the collection chamber. These types of apparatuses have been highly successful in both removing fluids from the pleural cavity and in maintaining the desired degree of negativity within the pleural cavity.
It has been found that nurses frequently will "milk" the thoracotomy tubes in an effort to remove any clots or obstructions from the tube. This "milking" of the tube is achieved by squeezing the flexible thoracotomy tube adjacent the upper end and drawing the fingers down the tube to cause the fluids within the tube to be passed out the lower end of the tube and into the collection chamber. Obviously, this action has the effect of substantially lowering the degree of negativity within the pleural cavity. Such high negativity can be damaging to the pleural cavity and may also cause the liquid within a combined water seal-collection chamber to be drawn up into the pleural cavity. In addition, the entire water seal can be lost into the pleural space or the collection chamber during periods of high negativity in the pleural cavity. The loss of the water seal has the potential for causing pneumothorax in the event that the suction becomes disconnected. Thus, there is need for a means of providing necessary relief for the condition of excess negativity in the pleural cavity.
In one of the applicant's pending U.S. application Ser. No. 256,152, a metered air pump is disclosed by which excess negative pressure can be relieved by pumping as many small units of air into the thoracotomy tube as necessary. In another of applicant's pending U.S. application Ser. No. 309,796, an automatically operated valve connects the thoracotomy tube directly with the atmosphere whenever excess negativity occurs.
When excess negativity is relieved in the collection chamber and/or the thoracotomy tube, it is important that the pressure in the collection chamber and/or the thoracotomy tube be prevented from reaching atmospheric pressure. Should the pressure in the collection chamber and/or the thoracotomy tube reach atmospheric pressure, the collection chamber immediately ceases to drain fluids from the pleural cavity, a pneumothorax develops, the lung collapses and breathing of the patient can quickly become difficult. So long as the collection chamber and/or the thoracotomy tube are subatmospheric, a pneumothorax does not occur.
Even though drainage devices have been developed which do not require a filling of the underwater seal chamber (see also, for example, U.S. Pat. Nos. 4,015,603 and 4,312,351), these devices generally do not provide a direct indication of the suction force being exerted. Such a feature is, of course, highly desirable in a drainage device.
SUMMARY OF THE INVENTION
In accordance with the present invention, an improved medical drainage device for draining fluids from the body of a patient is provided which enables the operator to incrementally control the suction being applied and which affords a direct indication of the suction pressure being applied to the suction chamber so the applied suction can be closely controlled. The suction pressure control and indicator arrangement is simple and rugged in construction and efficient and dependable in use. According to the invention, the surgical drainage apparatus comprises a container which is connected to a suction source so that fluids can be drawn into the container, a fluid inlet in the container, a collection chamber for collecting the fluids drawn into the container through the fluids inlet, a manually adjustable, incrementally variable control device for controlling the amount of suction created within the container, and an indicator arrangement responsive to the suction pressure created within the collection chamber for providing an indication of the applied suction. The apparatus of the invention is completely "dry" prior to use, i.e., does not require any prefilling by a user.
In a preferred embodiment of the invention, the basic component of the indicator arrangement is a bellows which is connected to the collection chamber of the drainage device and which contracts with increased suction in the collection chamber. A scale cooperates with a pointer or indicator attached to the bellows to provide an indication of the suction. In this preferred embodiment, the controllable, incrementally variable control device comprises a control valve which is connected to a suction line and which incrementally controls the amount of air supplied to the suction line and hence the suction pressure in the container. An air flow control sheath associated with the control valve enables the operator to "set" the desired pressure, and thus with the direct reading of the applied suction pressure provided by the indicator arrangement to the operator during adjustment of the sheath the suction can be closely monitored and controlled. A negative pressure relief valve which fluidly connects the suction line and the fluid inlet allows excess negative pressure in the inlet tube to be quickly relieved.
Other features and advantages of the invention will be set forth in, or apparent from, the detailed description of a preferred embodiment found hereinbelow.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a cross-sectional front view of a drainage apparatus according to the present invention.
FIG. 2 is a top view of the drainage apparatus depicted in FIG. 1.
FIG. 3 is a perspective view of the suction indicator of the present invention.
FIG. 4 is a perspective view of the incremental suction control of the present invention.
FIG. 5 is a cross-sectional view of the suction control depicted in FIG. 4.
FIG. 6 is a front elevation view of an alternative embodiment of a suction control.
FIG. 7 is a partial top plan view of the suction control depicted in FIG. 6.
FIG. 8 is a cross-sectional view taken along the line 8--8 in FIG. 7.
FIG. 9 is a partial bottom view of the suction control depicted in FIG. 6.
FIG. 10 is a side elevation view of the sheath depicted in FIG. 6.
FIG. 11 is a cutaway view of a portion of the sheath depicted in FIG. 10.
FIG. 12 is a cross-sectional front view of an alternative embodiment of a drainage apparatus according to the present invention.
FIG. 13 is a cross-sectional top view of an alternative embodiment of a suction indicator.
FIG. 14 is a cross-sectional rear view of the suction indicator depicted in FIG. 13.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
With reference now to the drawings in which like numerals represents like elements throughout the several views, a preferred embodiment of a drainage device 10 is depicted in FIGS. 1 and 2. Drainage device 10 comprises a housing 12 having a main collection chamber 14, a fluid seal chamber 16, and a suction control chamber 18. Collection chamber 14 merely comprises a container formed at the bottom of housing 10 for the collection of fluids drawn or sucked in by the drainage device 10 and need not be additionally described. Further, fluid seal chamber 16 is of the type described in commonly assigned U.S. Pat. No. 4,312,351 (Kurtz et al), the subject matter of which is hereby incorporated by reference, and reference is made to that patent for a more complete description of this feature. However, for the sake of completeness, fluid seal chamber 16 will also be briefly described here, together with suction control chamber 18.
Fluid seal chamber 16 includes therein a portion of an inlet tube 20 which extends through housing 12 and which is adapted to be connected to the patient through a throacotomy tube (not shown). The bottom of fluid seal chamber 16 is formed into a cup portion 22 into which inlet tube 20 opens. An opening 24 on one side of fluid seal chamber 16 allows the fluids collected in cup portion 22 to flow out over a ledge 26 and into main collection chamber 14.
Suction control chamber 18 includes an outlet tube 30 which is adapted to be connected to a suitable source of suction. An angled passageway 32 connects suction control chamber 18 with main collection chamber 14. Disposed between outlet tube 30 and angled passageway 32 is an umbrella valve means 34. Umbrella valve means 34 acts as a one way valve to permit the flow of fluids from main collection chamber 14 to outlet tube 30, but to prevent any reverse flow. Located near the top of suction control chamber 18 adjacent outlet tube 30 is an opening 36. Fluidly connected to opening 36 is a variable control means 40.
As shown in greater detail in FIGS. 4 and 5, variable control means 40 includes a tubular body 42 having a semicircular top portion 44 and a T-shaped bottom portion 46. Located along the top of semicircular portion 44 is a series of holes 48. Slidably mounted on tubular body 42 is a sheath 50 having a handle 52. As clearly shown in FIG. 5, sheath 50 completely surrounds tubular body 42 except for the lower extending portion of T-shaped portion 46 with which tubular body 42 is attached to the top of housing 12. T-shaped portion 46 also includes stops 54 so that sheath 50 can slide along tubular body 42 to a position where all of the holes except the first are completely covered by sheath 50.
Provided on top of housing 12 is a negative pressure relief valve 60. Relief valve 60 is connected on one side by a small passage 62 to inlet tube 20 and by a larger passageway 64 to opening 36. As shown best in FIG. 1, relief valve 60 includes a piston body 66 with an aperture 68 therethrough. Piston body 66 is normally held in the position depicted in FIG. 1 by a spring 70 acting on the bottom of piston body 66 so that aperture 68 is not aligned with passageways 62 and 64. O-ring 72 seals piston body 66 from passageways 62 and 64. Relief valve 60 includes a handle 74 which can be depressed to align aperture 68 with passageways 62 and 64.
As shown in FIGS. 1, 2 and 3, the suction indicating means 80 is located in a chamber 82 which is open to atmosphere. Suction indicating means 80 includes a bellows 84 mounted in chamber 82 which is connected through a spring 86 to one end wall of chamber 82. The other fixed end of bellows 84 is supported in chamber 82 by an L-shaped inlet tube 88. Inlet tube 88 is mounted along the other end wall of chamber 82. Inlet tube 88 opens into main collection chamber 14 and the interior of bellows 84 which is sealingly mounted to L-shaped inlet tube 88. The movable end of bellows 84 includes an indicator vane 90 mounted thereon which cooperates with a scale 92 provided on the upper wall of chamber 82 to indicate the imposed suction. In practice, in an exemplary embodiment under consideration, the imposed suction will vary from about -10 cm of water to about -100 cm of water. As chamber 82 is at atmospheric pressure, bellows 84 contracts when suction is applied therein through inlet tube 88. The amount of contraction is proportional to the applied suction and thus indicator vane 90 in cooperation with scale 92 provides a direct reading of the suction applied to main collection chamber 14 and the unit.
It is noted that the wall suction in a hospital or like facility is frequently set at a "wide open" setting and typically varies between 200 mm Hg and 750 mm Hg deadhead. This amount of suction can obviously cause problems in a drainage device, and to overcome these problems and permit the device of the invention to be directly connected to wall suction without controlling or modifying the latter, a restriction (not shown) is conveniently provided in outlet tube 30. This restriction is sized so that with control means 40 wide open (maximum air), the imposed suction will be about -10 cm of water. Obviously, other suction levels can be chosen as desired. This restriction in conbination with control means 40 provides a range discussed above, i.e., from about -10 cm of water to about -100 cm of water. It has been found that for a quarter inch (0.250 inch diameter) outlet tube, satisfactory results have been obtained where the size of the restriction ranges between about 0.050 inches and 0.187 inches. In general, the restriction provided should not be so great that, with control means 40 wide open, the desired minimum negativity cannot be achieved.
In operation, drainage device 10 functions in the following manner. Initially, inlet tube 20 is connected to the area of the patient to be drained and outlet tube 30 is connected to a suitable source of suction. The fluids collected from the patient through inlet tube 20 first fill fluid seal chamber 16 up to ledge 26 and then the fluids spill over into main collection chamber 14. As soon as the suction is connected to outlet tube 30, suction indicating means 80 immediately indicates the applied suction in main collection chamber 14 due to the movement of vane 90 relative to scale 92. The movement of vane 90 occurs as bellows 84 contracts under the applied suction in main collection chamber 14 against the force of spring 86. Depending on the reading of vane 90, variable control means 40 is adjusted to provide the negative pressure desired in collection chamber 14. Initially, variable control means 40 is adjusted so that sheath 50 covers all but the first hole in tubular body 42. Depending upon the suction pressure desired, sheath 50 is moved by pushing on handle 52 to uncover additional holds 48. In this manner, the suction pressure in main collection chamber 14 is incrementally adjusted as more holes 48 are uncovered.
In one embodiment of the present invention, the first hole only is open and provides a suction pressure of -100 cm of water. As additional holes are uncovered, the applied suction pressure in collection chamber 14 varies as follows: the first two holes open, minus 75 cm of water; first three holes open, minus 50 cm of water; first four holes open, minus 35 cm of water; first five holes open, minus 20 cm of water; and all six holes open, minus 10 cm of water. Obviously, a greater or lesser number of holes and the size of the holes can be varied to change the incremental pressures achieved by uncovering a set number of holes.
Should an excess negative pressure be created in the inlet tube 20, the fluid in fluid seal chamber 16 rises in inlet tube 20. As this is not desired, upon seeing the fluid in inlet tube 20, negative pressure relief valve 60 is actuated. By actuating relief valve 60, the controlled and desired suction pressure in suction control chamber 18 is fluidly connected to inlet tube 20. In this manner, the excess negative pressure in the thoracotomy tube is relieved as air is bled into inlet tube 20. It should be noted that small passageway 62 restricts the flow of air sufficiently so that where a short period of excess negativity is desired in inlet tube 20, this desired excess negativity is not immediately relieved. However, prolonged periods of undesired excess negativity are relieved.
Depicted in FIGS. 6 to 11 is an alternative embodiment of a suction control chamber 100. In this embodiment, an outlet tube 102 is provided with a restricted outlet passageway 104 and a larger passageway 106 in which an umbrella valve means 108 is located. Fluidly connected to larger passageway 106 above umbrella valve means 108 is a variable control means 110. Variable control means 110 includes a tubular body 112 with a closed outer end. As additionally shown in FIGS. 7, 8 and 9, a series of holes 114 is provided in tubular body 112. Hole 114 closest to outlet tube 102 is the largest of holes 114 while the second hole is the smallest of holes 114. The third and succeeding holes 114 are successively larger than the preceding hole. Tubular body 112 also includes a series of notches 116 located along the top outer surface of tubular body 112. Located along the bottom outer surface of tubular body 112 starting at the outer end thereof is an elongate slot 118.
With reference now to FIGS. 10 and 11 as well as FIG. 6, a sheath 120 for tubular body 112 is depicted. Sheath 120 includes a handle 122 and a cylindrical bore 124 with a closed end. Bore 124 is sized to snugly receive tubular body 112 such that sheath 120 is capable of sliding relative thereto. Upstanding from the bottom of bore 124 is a small peg 126. As sheath 120 slides onto tubular body 112, peg 126 is received in slot 118 to prevent sheath 120 from rotating relative to tubular body 112. Located in the top of bore 124 is a recess 128. Housed in recess 128 is a spring 130 which urges a ball 132 into bore 124. As sheath 120 is received on tubular body 112, ball 132 is pushed upward against the force of spring 130 into recess 128. As peg 126 prevents sheath 120 from rotating, ball 132 is positioned such that ball 132 resiliently engages notches 116 as sheath 120 advances along tubular body 112. Notches 116 are positioned such that ball 132 enters a respective notch 116 when a predetermined number of holes 116 are opened to atmosphere and not covered by sheath 120. In this manner, sheath 120 is easily positioned by handle 122 to a position where a desired number of holes 114 are exposed to atmosphere, and ball 132 resiliently engages the respective notch 116 to indicate the desired positioning of sheath 120 and to resiliently hold sheath 120 in place.
It should be noted that holes 114 vary in size from a very small second hole to a large last hole which is approximately the same size as the first hole. By providing holes 114 of different sizes, a more evenly distributed range of desired suction pressures are maintained in the collection chamber. Obviously, a greater number of holes can be provided for a greater increment of control over the suction pressure in the collection chamber.
Depicted in FIG. 12 is an alternative embodiment of a drainage device 10' comprising a housing 12' having a main collection chamber 14', a fluid seal chamber 16', and a suction control chamber 18'. Main collection chamber 14' and fluid seal chamber 16' having an inlet tube 20' are similar to main collection chamber 14 and fluid seal chamber 16 described above and will not be discussed further.
Suction control chamber 18' is similar in function to suction control chamber 18 and includes an outlet tube 30' connected to a housing 136 in which an umbrella valve means 34' is located. Located in this embodiment of housing 136 is a well 138. Should housing 12' be tipped allowing liquids to enter housing 136 through passageways 32', a portion of the liquids entering housing 136 will remain in well 138 and indicate that draingage device 10 has been tipped.
In this embodiment of the present invention, outlet tube 30' forms a portion of a variable control means 140 having a tubular body 142. One end of tubular body 142 is attached to housing 136 and the other end contains a restricted outlet 144. Disposed along a portion of the length of tubular body 142 are a series of holes 146. Tubular body 142 also has an externally threaded portion 148 which terminates at a stop 150. Surrounding tubular body 142 is a sheath 152 having an internally threaded portion 154 which mates with threaded portion 148 of tubular body 142. With this construction, sheath 152 is threadably received on tubular body 142 so that rotation of sheath 152 results in longitudinal movement of sheath 152 along tubular body 142. As sheath 152 is turned in one direction, holes 146 can be incrementally uncovered while rotation of sheath 152 in the other direction results in the incremental covering of holes 146. It should be noted that stop 150 prevents sheath 152 from advancing along tubular body 142 to a position where the uppermost hole 146 is covered.
Similar to drainage device 10, drainage device 10' is provided with a negative pressure relief valve 60' which is connected on one side by passageway 62' to inlet tube 20' and on the other side by passageway 64' to suction control chamber 18'. However, in this embodiment, a one-way "pop" valve 160 is disposed between negative pressure relief valve 60' and passageway 62'. One-way valve 160 permits fluid flow only from suction control chamber 18' to inlet tube 20' to relieve excess negative pressure in inlet tube 20'.
As shown in greater detail on FIGS. 13 and 14, drainage device 10' is provided with a suction indicating means 80' which is similar to suction indicating means 80 described above. Suction indicating means 80' includes a chamber 82', a bellows 84', a spring 86', and an inlet tube 88'. In this embodiment, an indicator vane 90' is rotatably mounted to chamber 82' on a stem 164. Mounted to stem 164 is a gear 166 which meshes with a rack 168 attached to the end of bellows 84'. With this construction, the expansion or contraction of bellows 84' causes the longitudinal movement of rack 168 which in turn rotates gear 166 and indicator vane 90'. Indicator vane 90' is located adjacent a scale and indicates the suction in collection chamber 14'.
The operation of drainage device 10' is similar to the operation of drainage device 10 described above and need not be discussed further.
Although the invention has been described relative to exemplary embodiments thereof, it will be understood that variations and modifications can be effected in these embodiments without departing from the scope and spirit of the invention.
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A surgical drainage unit is provided for draining fluids from the body of a patient wherein the suction pressure, applied through a suction inlet of the unit to draw fluids into the unit, is incrementally controlled and a direct indication of the applied suction pressure is afforded. A device which contracts responsive to an increase in suction in a collection chamber of the unit is equipped with an indicator vane that cooperates with a fixed scale to indicate the amount of movement of the bellows and hence indicate the suction within the collection chamber. A manually adjustable control valve incrementally controls the amount of air admitted to a suction line within the unit to thereby control the applied suction. A negative pressure relief valve is also provided so that excess negativity within the inlet tube can be manually relieved.
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BACKGROUND OF THE INVENTION
[0001] In a dry room or car interior, it may require a humidifier for humidifying the air for comfortable living or driving. However, it is not available or it is difficult to obtain a portable mini humidifier from the commercial source.
[0002] Even a prior art of U.S. Pat. No. 4,085,893 disclosed an ultrasonic humidifier for atomizing water or other liquid, which however has the following drawbacks:
1. A water supply system including conduit or tube must be provided for supplying the water to be atomized by an ultrasonic vibrator, thereby causing a complex structure and unsuitable for portable uses. 2. There is no sensor provided for sensing the humidity in the air. 3. There is also no indicator showing the water content in a water supply system.
[0006] The present inventor has found the drawbacks of the prior art and invented the present portable humidifier.
SUMMARY OF THE INVENTION
[0007] The object of the present invention is to provide a portable humidifier comprising: a bottle for storing water therein, a capillary device immersed in the bottle for capillarily absorbing water as stored in the bottle, an ultrasonic vibrator mounted on an upper portion of the bottle for normally contacting a top wick portion of the capillary device and operatively vibrating for compressing the top wick portion for ejecting water mists upwardly outwardly through a plurality of perforations formed through the vibrator, a control device formed on a top cover of the bottle for controlling the on-off operation of the vibrator, a sensor formed on the top cover for sensing the surrounding humidity for reminding the user whether to actuate the control device for humidifying the surrounding, and a light indicator for illuminating and checking water stored in the bottle to remind whether to refill water into the bottle.
BRIEF DESCRIPTION OF THE DRAWINGS
[0008] FIG. 1 is a perspective view of the present invention.
[0009] FIG. 2 is a sectional drawing of the present invention.
[0010] FIG. 3 is an exploded view showing the elements of the present invention.
[0011] FIG. 4 is a front-view illustration showing an inside wall of the sensor means having guiding ribs flared on the inside wall for homogeneously dispersing the water mists into the surrounding.
[0012] FIG. 5 is a partial sectional drawing of the present invention showing the depression of the control means and opening of the sensor means for spreading water mists outwardly.
[0013] FIG. 6 shows the closing of the sensor means and the restored control means for switching off the vibrator operation of the present invention.
DETAILED DESCRIPTION
[0014] As shown in the drawing figures, the present invention comprises: a housing 1 , a capillary means 2 , an ultrasonic vibrator 3 , a control means 4 adjacent to a rear side R of the housing 1 , a sensor means 5 adjacent to a front side F of the housing 1 , and a light indicator 6 .
[0015] The housing 1 includes: a transparent bottle 11 , a bottom holder 10 embedded on a bottom portion of the bottle 11 , a covering plate 111 formed on an upper portion of the bottle 11 for closing the bottle 11 having an upper opening 112 formed through the covering plate 111 for refilling water into the bottle 11 and for inserting the capillary means 2 into the bottle 11 by passing through the opening 112 , a side socket 110 formed in the bottle 11 for resiliently providing a coupler 13 in the socket 110 for coupling an upper casing 12 detachably engaged on an upper portion of the bottle 11 , and a top cover 14 encapping the upper casing 12 .
[0016] The capillary means 2 includes: a capillary tube 21 having its upper portion secured in the upper casing 12 of the housing 1 and protruding downwardly through a tube opening 121 formed through the upper casing 12 and through an upper opening 112 in the covering plate 111 to be inserted into the bottle 11 ; a wick member 22 longitudinally formed in the capillary tube 21 having a top wick portion 23 protruding upwardly from the capillary tube 21 to be contacted with the ultrasonic vibrator 3 ; a bottom plug 24 fixed on a bottom portion of the capillary tube 21 having a plurality of slots 241 formed in the plug 24 to be fluidically communicated with the wick member 22 disposed in the capillary tube 21 ; and a tension spring 25 retained in the lower portion of the capillary tube 21 and resiliently urging the wick member 22 upwardly to help a resilient contacting between the top wick portion 23 with the vibrator 3 .
[0017] The capillary means 2 may be inclinedly secured in the housing 1 as shown in FIG. 2 to increase the length of capillary tube for absorbing much water therein. The wick member 22 may be further protected by a sleeve disposed around the wick member 22 which is made of water-absorbable material, such as cotton, foam, etc.
[0018] The ultrasonic vibrator 3 includes: a piezoelectric actuator 31 secured in the upper casing 12 and electrically connected to the control means 4 ; and a perforated vibrating blade 32 having a plurality of perforations 33 formed through the blade 32 and secured to the piezoelectric actuator 31 , whereby upon switching-on of the control means 4 to actuate the piezoelectric actuator 31 , the vibrating blade 32 will be vibrated to compress the top wick portion 23 having water absorbed therein to eject water mists upwardly outwardly through the perforations 33 in the blade 32 to be spread into the environment through a front opening 141 formed in the top cover 14 .
[0019] Each perforation 33 formed in the vibrating blade 32 may have a diameter of 6˜9 microns, but not limited in the present invention.
[0020] The control means 4 includes: a button plate 41 pivotally secured in a rear portion of the top cover 14 by a pivot means 40 for normally shielding a rear opening 142 formed in the top cover 14 , a front tooth 42 formed on a front portion of the button plate 41 to be engaged with a pair of bifurcated teeth 511 formed in a rear portion of the sensor means 5 for opening the sensor means 5 , a switch button 43 resiliently formed on an electronic module 45 and having a button spring 44 disposed around the switch button 43 to normally urge a central bottom portion of the button plate 41 upwardly to be slightly separated from the switch button 43 ( FIGS. 2 and 6 ) to keep normal-open of the switch button 43 , and a power source adapter 46 adapted to be connected with an utility power supply and electrically connected to the electronic module 45 , with the electronic module 45 secured in a rear portion of the upper casing 12 .
[0021] The button plate 41 includes a bottom protrusion 411 preferably formed as an arcuate shape as shown in FIG. 5 for smoothly depressing the switch button 43 of the control means 4 .
[0022] The sensor means 5 includes: a sensor plate 51 pivotally secured in a rear portion of the top cover 14 by a pivot 50 formed on a rear portion of the sensor plate 51 for normally shielding a front opening 141 of the top cover 14 , a pair of bifurcated teeth 511 formed on a rearmost end portion of the sensor plate 51 to be engaged with the front tooth 42 of the button plate 41 of the control means 4 , a humidity indicator 52 secured in an indicator recess 512 formed in the sensor plate 51 for indicating the humidity as sensed from the surrounding through a vent 531 formed in a cover sheet 53 (with the cover sheet 53 covering the humidity indicator 52 on the sensor plate 51 ); with the sensor plate 51 corresponding to the vibrating blade 32 of the ultrasonic vibrator 3 adjacent to the front side F of the housing 1 ; whereby upon depression on the button plate 41 of the control means 4 , the front tooth 42 of the button plate 41 will downwardly bias the bifurcated teeth 511 to lift the sensor plate 51 from FIG. 6 to FIG. 5 to open the sensor plate 51 to allow the water mists as ejected by the ultrasonic vibrator 3 to be spread outwardly through the front opening 141 of the top cover 14 for humidifying the surrounding such as in a room or in a car. Simultaneously, the depression of the button plate 41 will downwardly depress the switch button 43 to actuate the ultrasonic vibrator 3 for ejecting the water mists upwardly.
[0023] The humidity indicator 52 may be a color-change indicator including cobalt chloride which will be changed from red color to blue color, indicating the change from a wet condition (red) to a dry condition (blue). When it shows a blue color, it indicates the environment is dry and the present invention may be actuated to spread water mists into the air for obtaining a suitable humidity.
[0024] The sensor plate 51 has its inside wall 54 formed with a plurality of guiding ribs 55 flared sidewardly from a longitudinal center of the inside wall 54 as shown in FIG. 4 for guiding the water mists as upwardly ejected from the ultrasonic vibrator 3 to be spread outwardly sidewardly for homogeneously dispersing the mists into the surrounding air for rapidly reaching a desired comfortable humidity.
[0025] The light indicator 6 includes: at least a lamp 61 such as a light-emitting diode (LED) mounted in a lower portion of the upper casing 12 for projecting light downwardly through a prism lens 62 formed in the covering plate 111 of the bottle 11 for illuminating the water stored in the bottle 11 for checking the water level L whether to refill water into the bottle or not.
[0026] The lamp 61 may be modified to be a plurality of LEDs with different colors and may be flashed as driven by a flashing circuit, not limited in the present invention.
[0027] Upon decoupling of the upper casing 12 from the bottle 11 by depressing the coupler 13 inwardly, the upper casing 12 and the elements implemented therein will be removed and the water may be re-filled into the bottle through the opening 112 .
[0028] When depressing the button plate 41 of the control means 4 for starting the ultrasonic vibrator 3 , the front tooth 42 , as engaged with the bifurcated teeth 511 of the sensor plate 51 , will be biased and lifted upwardly as shown in FIG. 5 , a rear tooth 511 r of the bifurcated teeth 511 will be frictionally engaged with the front tooth 42 to temporarily “lock” the front tooth 42 in position for continuously depressing the switch button 43 for actuating the vibrator 3 during the humidifying operation.
[0029] When it is intended to stop the humidification, the sensor plate 51 is lowered to close the opening 141 and the bifurcated teeth 511 will spur the front tooth 42 of the button plate 41 upwardly (from FIG. 5 to FIG. 6 ) to restore the button plate 41 to allow the button spring 44 to resiliently urge the protrusion 411 of the button plate 41 upwardly to be separated from the switch button 43 , remaining a gap G between the button 43 and the button plate 41 and thereby deactivating the vibrator 3 to stop its vibrating operation.
[0030] The present invention is superior to the prior art with the following advantages:
1. The humidifier is a compact portable unit, being easily carried and conveniently used in a tiny space. 2. A sensor is provided for checking when to start the ultrasonic vibrator for operating the humidifier in a more scientific way. 3. Light indicator (LED) is provided for always checking the water level (L) in the bottle and also for projecting color light into water for enriching beautiful ornamental effect. 4. Guide means is provided for guiding the water mists from the vibrator to be homogeneously spread outwardly to the air for a more uniform humidity within the room or in a car.
[0035] The present invention may be modified without departing from the spirit and scope of the present invention.
[0036] The housing may also be further added therein with air-refreshing agent, deodorant or other hygienic agents.
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A portable humidifier comprises: a bottle for storing water therein, a capillary device immersed in the bottle for capillarily absorbing water as stored in the bottle, an ultrasonic vibrator mounted on a upper portion of the bottle for normally contacting a top wick portion of the capillary device and operatively vibrating for compressing the top wick portion for ejecting water mists upwardly outwardly through a plurality of perforations formed through the vibrator, a control device formed on a top cover of the bottle for controlling the on-off operation of the vibrator, a sensor formed on the top cover for sensing the surrounding humidity for reminding the user whether to actuate the control device for humidifying the surrounding, and a light indicator for illuminating and checking water level in the bottle to remind whether to refill water into the bottle.
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CROSS-REFERENCE TO RELATED APPLICATION(S) AND CLAIM OF PRIORITY
[0001] The present application claims the benefit under 35 U.S.C. § 119(a) of a Korean patent application filed in the Korean Intellectual Property Office on Oct. 31, 2007 and assigned Serial No. 2007-110144, the entire disclosure of which is hereby incorporated by reference.
TECHNICAL FIELD OF THE INVENTION
[0002] The present invention relates to channel encoding in a communication system. More particularly, the present invention relates to a method and apparatus for a parallel structured Latin square interleaving in a communication system.
BACKGROUND OF THE INVENTION
[0003] Recently, with high data rates required in mobile communication and wireless data communication, there are greater requirements on communication bandwidth efficiency or reliability. In particular, an error may be detected from digital data due to several factors in the process of transmitting and receiving the digital data, in the process of recording and reading the digital data through a storage medium, or in a process of reproducing multimedia data (i.e., audio or video data). Such an error can be corrected or reduced by using many error control schemes which have been researched up to now. Examples of the error control schemes include a Forward Error Correction (FEC) protocol and an Automatic Repeat reQuest (ARQ) protocol. A turbo code may be used in the FEC. Along with a circular tail-biting coding scheme, researches on a parallel processing technique for turbo codes have actively been conducted.
[0004] FIG. 1 is a block diagram illustrating a parallel processing method of a turbo decoder. If a full block size or an interleaver size is N, one block is divided into L sub-blocks and then parallel processing is performed. Each block has a size of M, where M=N/L. Each block receives data information from a memory under the control of individual processors 1 to L. Decoding processes are simultaneously carried out. Each processor receives the data information according to an interleaving rule determined by an interleaver or a de-interleaver.
[0005] FIG. 2 is a diagram illustrating an example of a contention occurrence in a decoding process based on parallel processing when a block consists of 4 sub-blocks. As described in FIG. 1 above, each of processors performs interleaving by reading out a data information bit from a corresponding memory according to an interleaving rule. Referring to FIG. 2 , two processors (i.e., a processor 1 and a processor 2 ) simultaneously read out information from a first memory. Since any information can be accessed only by one processor at any one time, the information has to be accessed two times to be read out by the two processors. In this case, a contention may occur, which is indicated by 200 in FIG. 2 . The occurrence of contention results in deterioration of efficiency in parallel processing. In order to avoid such a contention, various contention-free interleavers have been proposed.
[0006] An Almost Regular Permutation (ARP) interleaver is proposed by Berror. The ARP interleaver may be found in <Document 1: Designing good permutations for turbo codes: towards a single model: C. Berrou, S. Kerouedan, Y. Saouter, C. Douillard, and M. Jezequel, June 2004., in Pro. Int. Conf. Commun., p 341˜345>. In comparison with the conventional interleaver, the ARP interleaver further provides irregularity by using a relatively prime property. The ARP interleaver is defined by Equation 1 below:
[0000] π( k )=( P·k+L ·(α( k )· P+ β( k ))+γ)(mod N ). [Eqn. 1]
[0007] In Equation 1, π(k) denotes an interleaving rule of an interleaver and indicates a permutation for reading out data information from a memory by each processor. P and N are relatively prime to one other. L denotes a parallel processing order. γ denotes an initial setup value. k satisfies a relation of 0≦k≦N−1. α(k), and β(k) are positive integers having a period of L. In general, α(k) has a value between 0 and 1, and β(k) has a value between 0 to 8. The ARP interleaver is adopted by various standards such as Institute of Electrical and Electronics Engineers (IEEE) 802.16, Digital Video Broadcast-Return Channel Satellite (DVB-RCS), Digital Video Broadcast-Return Channel Terrestrial (DVB-RCT), and so forth. In addition, the ARP interleaver is proposed as an interleaver for the 3rd Generation Partnership Project 2 (3GPP2) standard.
[0008] An algebraic method is used in a Quadratic Permutation Polynomial (QPP) interleaver which may be found in <Document 2: On Maximum Contention-Free Interleavers and Permutation Polynomials Over Integer Rings: O. Y. Takeshita, March 2006., IEEE Transaction Information Theory, p 1249˜1253>. The QPP interleaver is a maximum contention-free interleaver. The QPP interleaver satisfies a contention-free condition with respect to all sub-blocks (that is, N sub-blocks each having a size of M). The QPP interleaver is defined by Equation 2 below:
[0000] π( k )= f 1 ·k+f 1 ·k 2 (mod N ). [Eqn. 2]
[0009] In Equation 2, π(k) denotes an interleaving rule of an interleaver. f 1 and f 2 are positive integers. The aforementioned <Document 2> may be used as a reference for explaining the requirements on f 1 and f 2 .
[0010] In addition, there is an interleaver using a Latin square matrix, wherein the interleaver determines a mixing sequence in each sub-block by using the conventional interleaver having a short length. The Latin square matrix having a size of L×L consists of L different symbols. The respective symbols are presented one by one in all rows and columns. Such a Latin square pattern can be repeated to form an M×L matrix U which represents a Latin square interleaver. The Latin square interleaver is defined by Equation 3 below:
[0000] π( k )= u ts ·M+π T ( t ). [Eqn. 3]
[0011] In Equation 3, π(k) denotes an interleaving rule of an interleaver. π T (t) denotes a conventional sub-block interleaver. u ts denotes an element of a t th row and an s th column in the matrix U. M denotes a sub-block size. k satisfies a relation of k=s·M+t.
[0012] A turbo code having a parallel processing structure can be designed in a general system when parallel processing of various orders is possible for various-sized blocks supported in the system. Interleavers proposed to meet such a requirement have to undergo an optimization operation.
[0013] In case of the ARP interleaver disclosed in the aforementioned <Document 1> as the conventional technique, the following are taken into account when the optimization operation is performed. It is assumed that the initial setup value γ and the value a are determined. If k(mod L)=0, β(k) has a value of 0. Otherwise, if k(mod L)≠0, β(k) has a value between 0 to 8. In this case, the number of cases of approximately |P|·8L−1 has to be considered, where |x| denotes a cardinality of x.
[0014] In case of the QPP interleaver disclosed in the aforementioned <Document 2> as the conventional technique, there are two design methods according to a block length N. If N is divided by 4, f 1 and N are positive integers and are relatively prime to one other. If N is represented as a product of prime numbers, f2 is a positive integer of which elements are the prime numbers. Therefore, the total number of cases is |f1|·|f2|.
[0015] In case of the Latin square interleaver, if L=4, a total of 576 cases exists for a 4×4 Latin square matrix. A total of 24 cases exists for a reduced Latin square matrix, in which a first row is fixed to (0,1,2,3). Among the 24 cases, only 12 cases having a good distribution are taken into account. Therefore, the number of cases for the Latin square interleaver is less than that of the interleaver disclosed in the <Document 1> or <Document 2>.
[0016] In general, the parallel processing order is 4 for a turbo code having a small or medium block size. For a turbo code having a medium or large block size, the parallel processing order is 8 or 12, which is greater than 4. Table 1 below shows the number of cases to be considered for optimization by each interleaver with respect to 3 cases.
[0000]
TABLE 1
N = 320, L = 4
N = 640, L = 4
N = 1024, L = 8
ARP interleaver
40960
81920
1073741824
QPP interleaver
15200
55360
261632
conventional Latin
12
12
23309006400
square interleaver
[0017] In Table 1 above, the QPP interleaver considers a relatively less number of cases than the ARP interleaver but considers a significantly larger number of cases than the Latin square interleaver. In case of the Latin square interleaver, if L=4, only 12 cases are considered irrespective of a full block size. Disadvantageously, however, if L=8, the number of cases increases exponentially.
SUMMARY OF THE INVENTION
[0018] To address the above-discussed deficiencies of the prior art, it is a primary aspect of the present invention to solve at least the above-mentioned problems and/or disadvantages and to provide at least the advantages described below. Accordingly, an aspect of the present invention is to provide a method and apparatus for a contention-free interleaver having a good throughput while reducing the number of cases for optimization of the interleaver irrespective of a parallel processing order L and a block size N.
[0019] In accordance with an aspect of the present invention, an interleaving method using a parallel structured Latin square matrix in a communication system is provided. The method includes dividing input information bits into sub-blocks according to a parallel processing order, generating a first Latin square matrix or a second Latin square matrix by comparing the parallel processing order with a predetermined threshold, and performing interleaving by reading out the information bits divided into the sub-blocks according to the generated Latin square matrix.
[0020] In accordance with another aspect of the present invention, an interleaving apparatus using a parallel structured Latin square matrix in a communication system is provided. The apparatus divides input information bits into sub-blocks according to a parallel processing order, generates a first Latin square matrix or a second Latin square matrix by comparing the parallel processing order with a predetermined threshold, and performs interleaving by reading out the information bits divided into the sub-blocks according to the generated Latin square matrix.
[0021] Before undertaking the DETAILED DESCRIPTION OF THE INVENTION below, it may be advantageous to set forth definitions of certain words and phrases used throughout this patent document: the terms “include” and “comprise,” as well as derivatives thereof, mean inclusion without limitation; the term “or,” is inclusive, meaning and/or; the phrases “associated with” and “associated therewith,” as well as derivatives thereof, may mean to include, be included within, interconnect with, contain, be contained within, connect to or with, couple to or with, be communicable with, cooperate with, interleave, juxtapose, be proximate to, be bound to or with, have, have a property of, or the like. Definitions for certain words and phrases are provided throughout this patent document, those of ordinary skill in the art should understand that in many, if not most instances, such definitions apply to prior, as well as future uses of such defined words and phrases.
BRIEF DESCRIPTION OF THE DRAWINGS
[0022] For a more complete understanding of the present disclosure and its advantages, reference is now made to the following description taken in conjunction with the accompanying drawings, in which like reference numerals represent like parts:
[0023] FIG. 1 is a block diagram illustrating a parallel processing method of a turbo decoder;
[0024] FIG. 2 is a diagram illustrating an example of a contention occurrence in a decoding process based on parallel processing when a block consists of 4 sub-blocks;
[0025] FIG. 3 is a flowchart illustrating a process of performing interleaving using a parallel structured Latin square matrix according to an exemplary embodiment of the present invention;
[0026] FIG. 4 is a flowchart illustrating a process of configuring an extended Latin square matrix from a basic Latin square matrix according to an exemplary embodiment of the present invention;
[0027] FIG. 5 is a block diagram illustrating an apparatus for performing parallel structured interleaving according to an exemplary embodiment of the present invention;
[0028] FIG. 6 is a diagram illustrating a process of performing Latin square interleaving according to an exemplary embodiment of the present invention;
[0029] FIG. 7A is a graph illustrating a Frame Error Rate (FER) with respect to a signal to noise ratio (i.e., E b /N o ) to compare a throughput of a Latin square interleaver and a throughput of an Almost Regular Permutation (ARP) interleaver when a parallel processing order is 4 and a full block length M is 640 according to an exemplary embodiment of the present invention; and
[0030] FIG. 7B is a graph illustrating an FER with respect to an E b /N 0 to compare a throughput of a Latin square interleaver and a throughput of a Quadratic Permutation Polynomial (QPP) interleaver when a parallel processing order is 8 and a full block length M is 1024 according to an exemplary embodiment of the present invention.
DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS
[0031] FIGS. 3 through 7B , discussed below, and the various embodiments used to describe the principles of the present disclosure in this patent document are by way of illustration only and should not be construed in any way to limit the scope of the disclosure. Those skilled in the art will understand that the principles of the present disclosure may be implemented in any suitably arranged wireless communication system.
[0032] Hereinafter, a method and apparatus for performing interleaving by configuring a Latin square matrix while avoiding a memory contention in a wireless communication system will be described. The Latin square matrix is extended from a basic Latin square matrix according to a parallel processing order.
[0033] FIG. 3 is a flowchart illustrating a process of performing interleaving using a parallel structured Latin square matrix according to an exemplary embodiment of the present invention.
[0034] Referring to FIG. 3 , in step 300 , a transmitter divides a full data block N into L sub-blocks according to a parallel processing order L required in the system. Each sub-block has a size of M, where M=N/L.
[0035] In step 302 , the transmitter determines whether the parallel processing order L is greater than a predetermined threshold. If the parallel processing order L is less than the threshold, proceeding to step 310 , the transmitter performs interleaving by using the conventional Latin square interleaver (see the Latin square interleaver disclosed in the Background of the Invention). In the conventional Latin square interleaver, in comparison with other interleavers (i.e., see <Document 1> and <Document 2>), the number of cases for optimization of the interleaver exponentially increases along with the increase in the full data block size N and the parallel processing order L. On the contrary, in comparison with other interleavers (i.e., see <Document 1> and <Document 2>), the number of cases for optimization of the interleaver is significantly small when the parallel processing order L is less than the threshold.
[0036] If the parallel processing order L is greater than the threshold in step 302 , proceeding to step 304 , the transmitter configures an l×l Latin square matrix. Herein, l is a constant less than the parallel processing order L, where L and l are not relatively prime to one other (that is, L is a multiple of l). The Latin square matrix is a matrix in which, when l different elements are arranged in a square form consisting of l rows and l columns, there is no duplicated element in the rows and columns. The l×l Latin square matrix is expressed by Equation 4 below:
[0000]
u
l
=
[
a
11
a
12
…
a
1
l
a
21
a
22
a
2
l
⋮
⋰
⋮
a
l
1
a
l
2
…
a
ll
]
.
[
Eqn
.
4
]
[0037] In Equation 4, u l denotes an l×l Latin square matrix, and a i,j denotes an element of an i th row and a j th column of u l . To reduce the number of cases for optimization of the interleaver, a first row (a 11 a 12 . . . a 1l ) of u l can be set to (0 1 2 . . . l) to form the Latin square matrix, which is called an l×l reduced Latin square matrix. In addition thereto, the l×l Latin square matrix can be configured in various forms.
[0038] In step 306 , the transmitter generates an extended Latin square matrix by using the l×l Latin square matrix. The basic l×l Latin square matrix of Equation 4 above can be extended to generate the extended Latin square matrix having a size of L=n·l, which is expressed by Equation 5 below. Herein, n denotes a parameter for converting the Latin square matrix u l into a Latin square matrix u L having a size required by the system.
[0000]
u
L
=
(
u
l
)
(
n
)
=
(
[
a
11
a
12
…
a
1
l
a
21
a
22
a
2
l
⋮
⋰
⋮
a
l
1
a
l
2
…
a
ll
]
)
(
n
)
=
[
a
11
…
a
1
l
a
11
(
1
)
…
a
1
l
(
1
)
…
a
11
(
n
-
1
)
…
a
1
l
(
n
-
1
)
a
21
(
n
-
1
)
…
a
21
(
n
-
1
)
a
21
…
a
2
l
…
a
21
(
n
-
2
)
…
a
2
l
(
n
-
2
)
⋮
⋮
⋮
⋮
⋰
⋮
⋮
a
11
(
1
)
…
a
1
l
(
1
)
a
11
(
2
)
…
a
1
l
(
2
)
…
a
11
…
a
1
l
a
21
…
a
2
l
a
21
(
1
)
…
a
2
l
(
1
)
…
a
21
(
n
-
1
)
…
a
2
l
(
n
-
1
)
⋮
⋮
⋮
⋮
⋰
⋮
⋮
⋮
⋮
⋮
⋮
⋰
⋮
⋮
a
11
(
n
-
1
)
…
a
1
l
(
n
-
1
)
a
11
…
a
1
l
…
a
11
(
n
-
2
)
…
a
1
l
(
n
-
2
)
a
21
(
n
-
2
)
…
a
2
l
(
n
-
2
)
a
21
(
n
-
1
)
…
a
2
l
(
n
-
1
)
…
a
21
(
n
-
3
)
…
a
2
l
(
n
-
3
)
⋮
⋮
⋮
⋮
⋰
⋮
⋮
]
[
Eqn
.
5
]
[0039] In Equation 5, when u l is an l×l Latin square matrix, (u l ) (n) is extended into u n·1 which is an extended Latin square matrix. Herein, a ij (k) =a ij +l·k and 0≦k≦n−1. The L×L matrix extended according to Equation 5 above has a form in which L different symbols are transposed in every row and column, thereby forming a Latin square matrix. If u l has a reduced format, u L also has a reduced format. Details thereof will be described below with reference to FIG. 4 .
[0040] In step 308 , the transmitter performs full interleaving by combining interleaving results in each sub-block unit by the use of the extended Latin square matrix.
[0041] Thereafter, the procedure of FIG. 3 ends.
[0042] As described above with reference to FIG. 3 , in a method of designing a Latin square interleaver of the present invention, when a parallel processing order required by the system is high, Latin square matrixes having a size required by the system are generated by extending a basic Latin square matrix having a small size. In addition, Latin square interleavers are configured using the generated extended Latin square matrixes to select an interleaver that provides an optimal throughout. In the case of a sub-block interleaver, the conventional interleaver can be used, if necessary, with modification.
[0043] FIG. 4 is a flowchart illustrating a process of configuring an extended Latin square matrix from a basic Latin square matrix according to an exemplary embodiment of the present invention.
[0044] Referring to FIG. 4 , an interleaver initializes values i, j, and n in step 400 . The value i is a time index. The value j is a parallel processing index. The value n is a parameter for converting a reduced Latin square matrix into a new Latin square matrix having a size required by the system. According to embodiments, the value j may be defined as the time index, and the value i may be defined as the parallel processing index.
[0045] In step 402 , the interleaver initializes a counter to 0. The counter is used to perform an operation by the number of times corresponding to a size of the row (or column) of the Latin square matrix required by the system.
[0046] In step 404 , the interleaver extends the row (or column) of the extended Latin square matrix u L by using a ij (k) =a ij +l·k from a permutation of a row (or column) (i.e., 0, 1, 2, . . . , l−1) of the reduced Latin square matrix u l . Herein, k satisfies a relation of 0≦k≦n−1.
[0047] For example, a first row (a 11 a 12 . . . a 1l ) of the l×l Latin square matrix of Equation 4 is extended to the first row (a 11 a 12 . . . a 1l a 11 (1) a 12 (1) . . . a 1l (1) a 11 (2) a 12 (2) . . . a 1l (2) . . . a a 11 (n) a 12 (n) . . . a 1l (n) ) of the L×L Latin square matrix of FIG. 5 . Likewise, second to L th rows are also extended according to Equation 5.
[0048] In step 406 , the interleaver stores the generated row (or column) at a position corresponding to the count.
[0049] In step 408 , the interleaver increments the count value. In step 410 , the interleaver determines whether the count value is less than a parallel processing order L. If the count value is greater than the parallel processing order L, the procedure ends. Otherwise, if the count value is less than the parallel processing order L, returning to step 404 , steps 404 to 410 are repeated by the number of times corresponding to the size of the row (or column) of the Latin square matrix required by the system. By repeating steps 404 to 408 according to the parallel processing order L, the extended Latin square matrix is generated as shown in Equation 5 above. According to embodiments, processing may be performed in a matrix unit rather than a row or column unit.
[0050] Thereafter, the procedure of FIG. 4 ends.
[0051] Now, an example of an extended Latin squared matrix will be described under the assumption that a parallel processing order is 4. First, a 4×4 reduced Latin square matrix having a parallel processing order L of 4 is expressed by Equation 6 below:
[0000]
u
4
=
[
a
11
a
12
a
13
a
14
a
21
a
22
a
23
a
24
a
31
a
32
a
33
a
34
a
41
a
42
a
43
a
44
]
,
u
4
=
[
0
1
2
3
2
3
0
1
3
0
1
2
1
2
3
0
]
.
[
Eqn
.
6
]
[0052] In Equation 6, u 4 has a reduced format in which a first row (a 11 a 12 a 13 a 14 ) always has values of (0 1 2 3). u 4 can be extended into u 8 by using Equation 5 above. The extended matrix u 8 is expressed by Equation 7 below:
[0000]
u
8
=
(
u
4
)
(
2
)
=
(
[
a
11
a
12
a
13
a
14
a
21
a
22
a
23
a
24
a
31
a
32
a
33
a
34
a
41
a
42
a
43
a
44
]
)
(
2
)
=
[
a
11
a
12
a
13
a
14
a
11
(
1
)
a
12
(
1
)
a
13
(
1
)
a
14
(
1
)
a
21
(
1
)
a
22
(
1
)
a
23
(
1
)
a
24
(
1
)
a
21
a
22
a
23
a
24
a
31
a
32
a
33
a
34
a
31
(
1
)
a
32
(
1
)
a
33
(
1
)
a
34
(
1
)
a
41
(
1
)
a
42
(
1
)
a
43
(
1
)
a
44
(
1
)
a
41
a
42
a
43
a
44
a
11
(
1
)
a
12
(
1
)
a
13
(
1
)
a
14
(
1
)
a
11
a
12
a
13
a
14
a
21
a
22
a
23
a
24
a
21
(
1
)
a
22
(
1
)
a
23
(
1
)
a
24
(
1
)
a
31
(
1
)
a
32
(
1
)
a
33
(
1
)
a
34
(
1
)
a
31
a
32
a
33
a
34
a
41
a
42
a
43
a
44
a
41
(
1
)
a
42
(
1
)
a
43
(
1
)
a
44
(
1
)
]
u
8
=
(
[
0
1
2
3
2
3
0
1
3
0
1
2
1
2
3
0
]
)
2
=
[
0
1
2
3
4
5
6
7
5
6
7
4
1
2
3
0
3
0
1
2
7
4
5
6
6
7
4
5
2
3
0
1
4
5
6
7
0
1
2
3
1
2
3
0
5
6
7
0
7
4
5
6
3
0
1
2
2
3
0
1
6
7
4
5
]
[
Eqn
.
7
]
[0053] In Equation 7, a first column (a 11 a 12 a 13 a 14 a 11 (1) a 12 (1) a 13 (1) a 14 (1) ) of u 8 is (0 1 2 3 4(a 11 (1) =a 11 +k*1=0+1*4) 5(a 12 (1) =a12+k*1=1+1*4) 6(a 13 (1) =a 13 +k*1=2+1*4) 7(a 14 (1) =a 14 +k*1=3+1*4))=(0 1 2 3 4 5 6 7). A second column (a 12 (1) a 22 (1) a 23 (1) a 24 (1) a 21 a 22 a 23 a 24 ) of u 8 is (5(a 21 (1) =a 21 +k*1=2+1*4) 6(a 22 (1) =a 22 (1) =a 22 +k*1=2+1*4) 7(a 23 (1) =a 23 +k*1=3+1*4) 4(a 24 (1) =a 24 +k*1=0+1*4) 1 2 3 0)=(5 6 7 4 1 2 3 0). In this manner, elements of the remaining columns can be calculated.
[0054] If n=3, u 4 is extended by Equation 8 below:
[0000]
u
12
=
(
u
4
)
(
3
)
=
(
[
a
11
a
12
a
13
a
14
a
21
a
22
a
23
a
24
a
31
a
32
a
33
a
34
a
41
a
42
a
43
a
44
]
)
(
3
)
=
[
a
11
a
12
a
13
a
14
a
11
(
1
)
a
12
(
1
)
a
13
(
1
)
a
14
(
1
)
a
11
(
2
)
a
12
(
2
)
a
13
(
2
)
a
14
(
2
)
a
21
(
2
)
a
22
(
2
)
a
23
(
2
)
a
24
(
2
)
a
21
a
22
a
23
a
24
a
21
(
1
)
a
22
(
1
)
a
23
(
1
)
a
24
(
1
)
a
31
(
1
)
a
32
(
1
)
a
33
(
1
)
a
34
(
1
)
a
31
(
2
)
a
32
(
2
)
a
33
(
2
)
a
34
(
2
)
a
31
a
32
a
33
a
34
a
41
a
42
a
43
a
44
a
41
(
1
)
a
42
(
1
)
a
43
(
1
)
a
44
(
1
)
a
41
(
2
)
a
42
(
2
)
a
43
(
2
)
a
44
(
2
)
a
11
(
1
)
a
12
(
1
)
a
13
(
1
)
a
14
(
1
)
a
11
(
2
)
a
12
(
2
)
a
13
(
2
)
a
14
(
2
)
a
11
a
12
a
13
a
14
a
21
a
22
a
23
a
24
a
21
(
1
)
a
22
(
1
)
a
23
(
1
)
a
24
(
1
)
a
21
(
2
)
a
22
(
2
)
a
23
(
2
)
a
24
(
2
)
a
31
(
2
)
a
32
(
2
)
a
33
(
2
)
a
34
(
2
)
a
31
a
32
a
33
a
34
a
31
(
1
)
a
32
(
1
)
a
33
(
1
)
a
34
(
1
)
a
41
(
1
)
a
42
(
1
)
a
43
(
1
)
a
44
(
1
)
a
41
(
2
)
a
42
(
2
)
a
43
(
2
)
a
44
(
2
)
a
41
a
42
a
43
a
44
a
11
(
2
)
a
12
(
2
)
a
13
(
2
)
a
14
(
2
)
a
11
a
12
a
13
a
14
a
11
(
1
)
a
12
(
1
)
a
13
(
1
)
a
14
(
1
)
a
21
(
1
)
a
22
(
1
)
a
23
(
1
)
a
24
(
1
)
a
21
(
2
)
a
22
(
2
)
a
23
(
2
)
a
24
(
2
)
a
21
a
22
a
23
a
24
a
31
a
32
a
33
a
34
a
31
(
1
)
a
32
(
1
)
a
33
(
1
)
a
34
(
1
)
a
31
(
2
)
a
32
(
2
)
a
33
(
2
)
a
34
(
2
)
a
41
(
2
)
a
42
(
2
)
a
43
(
2
)
a
44
(
2
)
a
41
a
42
a
43
a
44
a
41
(
1
)
a
42
(
1
)
a
43
(
1
)
a
44
(
1
)
]
[
Eqn
.
8
]
[0055] There are a total of 24 cases for u 4 having a reduced format defined by Equation 6. In addition, there are also a total of 24 cases for u 8 of Equation 7 and u 12 of Equation 8. Therefore, the number of cases to be considered for optimization of interleaving is determined to be small according to the reduced Latin square matrix irrespective of the parallel processing order.
[0056] FIG. 5 is a block diagram illustrating an apparatus for performing parallel structured interleaving according to an exemplary embodiment of the present invention.
[0057] Referring to FIG. 5 , a fill data block is divided into a plurality of sub-blocks according to a parallel processing order L. Data information consists of the respective sub-blocks and is stored in each of memories 1 to L. A sub-block interleaver reads out the data information stored in each of the memories 1 to L according to an interleaving rule. The sub-block interleaver may be a conventional interleaver. A plurality of sub-block interleavers performs the same interleaving operation. Data information bits are mixed by the respective sub-block interleavers. Data is output by being combined between blocks by a Latin square interleaver.
[0058] According to the present invention, the Latin square interleaver is designed differently depending on the parallel processing order. In general, if the full data block length N has a small or medium size (about 2000 or below), a required parallel processing order is low. If the full data block length has a medium or large size (about 1000 or above), the required parallel processing order is high. That is, when the parallel processing order is low, the Latin square matrix is configured according to the conventional Latin square interleaving method. If the parallel processing order L required by the system is high, an L×L extended Latin square matrix is configured using an l×l reduced Latin square matrix. Herein, l is an integer less than L, where l is not relatively prime to L (i.e., L is a multiple of l). A method of configuring the L×L extended Latin square matrix by using the l×l reduced Latin square matrix has been described above in detail with reference to FIG. 4 .
[0059] As such, the Latin square interleaver configures a Latin square matrix according to a parallel processing order (see Equation 7 and Equation 8), and then performs interleaving on data according to the configured Latin square matrix.
[0060] The configured Latin square matrix generates an M×L matrix in an iterative format. An interleaver function is performed according to Equation 3. FIG. 6 is a diagram illustrating a process of performing Latin square interleaving defined by Equation 3. For example, when information is read from a memory at a k th location of a first processor 1 , information at a π T (t) th location of a u t0 th sub-block defined by the matrix U is read. When information is read from the memory at a k th location of a second processor 2 , the information at the π T (t) th location of a u t1 th sub-block is read. Likewise, L processors simultaneously read the information at the π T (t) th location from the sub-block location defined by the matrix U. Thus, parallel processing is performed. A memory contention does not occur since the same sub-block index does not exist in one row or column according to characteristics of the Latin square matrix.
[0061] FIG. 7A is a graph illustrating a Frame Error Rate (FER) with respect to a signal to noise ratio (i.e., E b /N o ) to compare a throughput of a Latin square interleaver and a throughput of an Almost Regular Permutation (ARP) interleaver when a parallel processing order is 4 and a full block length M is 640 according to an exemplary embodiment of the present invention. Parameters of the ARP interleaver used herein are proposed by the 3GPP2 standard. The parameters of the ARP interleaver are expressed by Equation 9 below:
[0000] P= 201, L= 4, α=(0,0,1,1), β=(0,6,3,1), γ=3. [Eqn. 9]
[0062] For the Latin square interleaver, a 3GPP interleaver having a length of 160 is used as a sub-block interleaver. The Latin square interleaver has a format of Equation 10 below:
[0000]
u
4
=
[
0
1
2
3
2
3
0
1
3
0
1
2
1
2
3
0
]
[
Eqn
.
10
]
[0063] A full coding rate is ⅓. An incident matrix of a configured convolution code is expressed by Equation 11 below. A max long-MAP is used as a decoding scheme. Decoding is repeated up to 8 times. The decoding is finished when no error is detected from a decoded bit in the decoding process.
[0000]
g
(
D
)
=
[
1
1
+
D
+
D
3
1
+
D
2
+
D
3
]
.
[
Eqn
.
11
]
[0064] Referring to FIG. 7A , the Latin square interleaver and the ARP interleaver show similar throughputs until the E b /N o reaches approximately 1.5 dB. After 1.5 dB, the ARP interleaver shows a slightly better throughput. After the E b /N o reaches approximately 2.25 dB, the throughput of the ARP interleaver is almost constant even if the E b /N 0 increases. However, the Latin square interleaver shows an excellent throughput even if the E b /N 0 is high, which is indicated by 700 in FIG. 7A .
[0065] FIG. 7B is a graph illustrating an FER with respect to an E b /N o to compare a throughput of a Latin square interleaver and a throughput of a Quadratic Permutation Polynomial (QPP) interleaver when a parallel processing order is 8 and a full block length M is 1024 according to an exemplary embodiment of the present invention. The parameters of the QPP interleaver are expressed by Equation 12 below:
[0000] f 1 =31, f 2 =64. [Eqn. 12]
[0066] For the Latin square interleaver, a 3GPP interleaver having a length of 128 is used as a sub-block interleaver. The Latin square interleaver has a format of Equation 13 below:
[0000]
u
8
=
(
[
0
1
2
3
2
3
0
1
3
0
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[0067] Other simulation conditions are similar to those of FIG. 7A . The two interleavers show the almost same throughputs until the E b /N 0 reaches approximately 1.25 dB. After 1.25 dB, the QPP interleaver shows a better throughput until the E b /N o reaches approximately 1.8 dB. However, the throughput of QPP interleaver shows less improvement even if the E b /N o increases. Similarly to the APP interleaver, the proposed Latin square interleaver shows an excellent throughput even if the E b /N o is high, which is indicated by 702 in FIG. 7B .
[0068] As described above, a communication system of the present invention performs interleaving by configuring a Latin square interleaver according to a parallel processing order. Therefore, there is an advantage in that the number of cases to be considered for optimization of the interleaver is significantly smaller than other interleavers. Further, the proposed interleaver shows a throughput almost the same as that of other contention-free interleavers. In particular, a throughput (i.e., FER) is improved at a high signal to noise ratio (i.e., E b /N o ). Furthermore, any type of conventional interleavers can be used as a sub-block interleaver.
[0069] While the present invention has been shown and described with reference to certain exemplary embodiments thereof, it will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the present invention as defined by the appended claims and their equivalents. Therefore, the scope of the invention is defined not by the detailed description of the invention but by the appended claims and their equivalents, and all differences within the scope will be construed as being included in the present invention.
[0070] Although the present disclosure has been described with an exemplary embodiment, various changes and modifications may be suggested to one skilled in the art. It is intended that the present disclosure encompass such changes and modifications as fall within the scope of the appended claims.
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A method and apparatus for parallel structured Latin square interleaving in a communication system are provided. The method includes dividing input information bits into sub-blocks according to a parallel processing order, generating a first Latin square matrix or a second Latin square matrix by comparing the parallel processing order with a predetermined threshold, and interleaving by reading out the information bits divided into the sub-blocks according to the generated Latin square matrix.
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RELATED APPLICATIONS
This application claims priority to Taiwan Application Serial Number TW 104127031, filed Aug. 19, 2015, which is herein incorporated by reference.
BACKGROUND
Field of Invention
The present invention relates to a photosensitive resin composition and its application thereof. More particularly, the present invention relates to a film formed by the photosensitive resin composition and its application thereof. The film has a good refractivity and adhesivity to molybdenum (Mo).
Description of Related Art
In the manufacturing process of a liquid crystal display component, forming a protective film on a substrate is an important step. Demanding procedures under harsh conditions are required for manufacturing a liquid crystal display component or a solid-state imaging device, etc. For example, local high temperature occurs when processing by infusion with an acid solvent or alkaline solvent on the surface of substrate or by sputtering to form a wiring electrode layer. Thus, the protective film is laid on these components to prevent them from damage. Nowadays, the protective film is generally formed on the substrate by subjecting a photosensitive resin to processes of coating, exposure and developing, etc.
To enable the protective film to resist the aforementioned harsh conditions of the processes, high transparency, high surface hardness and smoothness are required, along with an excellent adhesivity between the protective film and substrate. Moreover, good resistance to water, solvents, acid, alkali and the like of the protective film is also required. In the aforementioned characteristics, since the protective film is formed on a color filter or a substrate, the requirement of high transparency is critical. If the transparency of the protective film is poor, when the protective film is applied to the liquid crystal display element, the brightness of the liquid crystal display element is insufficient, and the display quality of the liquid crystal display element is impacted.
To improve the transparency of the protective film, Japanese Patent Publication No. 2010-054561 disclosed a photosensitive composition for a protective film, comprising: an alkali-soluble bonding resin (A), a compound having a vinyl unsaturated group (B), a photoinitiator (C), and a solvent (D), in which the bonding equivalence of the unsaturated bond in the compound having a vinyl unsaturated group (B) is between 90 and 450 g/eq, and the amount of unsaturated double bond of a single compound is between 2 and 4 in the compound having a vinyl unsaturated group (B). A weight average molecular weight of the alkali-soluble bonding resin (A) is between 10,000 and 20,000.
Additionally, Japanese Patent Publication No. 2004-240241 has disclosed a photosensitive composition comprising: a copolymer (A), a polymer having a vinyl unsaturated group (B) and a photoinitiator (C). The copolymer (A) is polymerized by an unsaturated carboxyl (anhydride) having a vinyl group, a compound having a vinyl unsaturated group containing an epoxy group and other compounds having a vinyl unsaturated group. The photoinitiator (C) is 2-butanedione-[-4-methylthio benzene]-2-(O-oxime acetate), 1,2-butanedione-1-(-4-morpholino phenyl)-2-(O-benzoyl oxime), 1,2-octadione-1-[4-thiophenyl benzene]-2[O-(4-methyl benzoyl) oxime] or the like. However, the film formed by the photosensitive resin composition is unable to satisfy increasing requirements of refractivity and adhesivity to molybdenum.
Therefore, how to achieve the requirements of the refractivity and the adhesivity to molybdenum at the same time is a goal in the technical field of the present invention.
SUMMARY
Therefore, one of an aspect of the present invention is to provide a photosensitive resin composition.
Another aspect of the present invention is to provide a film formed by the photosensitive resin composition, and having a good refractivity and adhesivity to molybdenum.
The other aspect of the present invention is to provide a device including the aforementioned film.
According to the aspects of the present invention, a photosensitive resin composition is provided. The photosensitive resin composition comprises an alkali-soluble resin (A), a compound having a vinyl unsaturated group (B), a photoinitiator (C), a solvent (D) and a silane compound (E), in which the silane compound (E) includes a silane compound (E-1). The details are described as below.
PHOTOSENSITIVE RESIN COMPOSITION
An Alkali-Soluble Resin (A)
A Resin Having an Unsaturated Group (A-1)
The alkali-soluble resin (A) includes a resin having an unsaturated group (A-1). The resin having an unsaturated group (A-1) is prepared by polymerizing a mixture, in which the mixture includes an epoxy compound having at least two epoxy groups (a-1-1) and a compound having at least one carboxyl group and at least one vinyl unsaturated group (a-1-2). Preferably, the mixture can selectively include a carboxylic anhydride compound (a-1-3) and/or a compound having an epoxy group (a-1-4).
In one example of the present invention, the epoxy compound having at least two epoxy groups (a-1-1) of the resin having an unsaturated group (A-1) may have a structure of formula (a-I):
in the formula (a-I), R 1 , R 2 , R 3 and R 4 individually and independently represent a hydrogen atom, a halogen atom, an alkyl group of 1 to 5 carbons, an alkoxy group of 1 to 5 carbons, an aryl group of 6 to 12 carbons or an aralkyl group of 6 to 12 carbons.
The epoxy compound having at least two epoxy groups (a-1-1) having a structure of the formula (a-I) can include but is not limited to a bisphenol fluorene compound having epoxy groups which is obtained by reacting bisphenol fluorine with epihalohydrin.
For examples, the aforementioned bisphenol fluorene can include but is not limited to 9,9-bis(4-hydroxyphenyl)fluorene, 9,9-bis(4-hydroxy-3-methylphenyl)fluorene, 9,9-bis(4-hydroxy-3-chlorophenyl)fluorene, 9,9-bis(4-hydroxy-3-bromophenyl)fluorene, 9,9-bis(4-hydroxy-3-fluorophenyl)fluorene, 9,9-bis(4-hydroxy-3-methoxyphenyl)fluorene, 9,9-bis(4-hydroxy-3,5-dimethylphenyl)fluorene, 9,9-bis(4-hydroxy-3,5-dichlorophenyl)fluorene, 9,9-bis(4-hydroxy-3,5-dibromophenyl)fluorene, and the like.
The aforementioned epihalohydrin may include but is not limited to epichlorohydrin, epibromohydrin or the like.
The aforementioned bisphenol fluorine having epoxy groups may include but is not limited to (1) commercial products, manufactured by Nippon Steel Chemical Co. Ltd., and the trade names are ESF-300 or the like; (2) products manufactured by Osaka Gas Co. Ltd., and the trade names are PG-100, EG-210 or the like; (3) products manufactured by S.M.S. Technology Co. Ltd., and the trade names are SMS-F9PhPG, SMS-F9CrG, SMS-F914PG or the like.
In the other example of the present invention, the epoxy compound having at least two epoxy groups (a-1-1) of the resin having the unsaturated group (A-1) may have a structure of formula (a-II):
in the formula (a-II), R 5 to R 18 individually and independently represent a hydrogen atom, a halogen atom, an alkyl group of 1 to 8 carbons, an aryl group of 6 to 15 carbons, and the n represents an integer from 0 to 10.
The epoxy compound having at least two epoxy groups (a-1-1) having a structure of the formula (a-II) is obtained by reacting a compound with the structure shown in formula (a-II-1) with epihalohydrin in the presence of alkali metal hydroxides:
in the formula (a-II-1), R 5 to R 18 and n have the same definitions as above, therefore it is not repeated here.
Moreover, in presence of an acid catalyst, the epoxy compound having at least two epoxy groups (a-1-1) with a structure of the formula (a-II) is obtained by the following steps. A compound having a structure of the formula (a-II-2) is reacted with phenol compounds by a condensation reaction, and thus the aforementioned compound having a structure of the formula (a-II-1) is obtained. And then, an excess amount of epihalohydrin are added to subject to a dehydrohalogenation reaction, so as to obtain the epoxy compound having at least two epoxy groups (a-1-1) with a structure of formula (a-II).
in formula (a-II-2), R 19 and R 20 can be the same or different, and R 19 and R 20 independently represent a hydrogen atom, a halogen atom, an alkyl group of 1 to 8 carbons, an aryl group of 6 to 15 carbons; X 1 and X 2 can be the same or different, and X 1 and X 2 independently represent a halogen atom, an alkyl group of 1 to 6 carbons or an alkoxy group of 1 to 6 carbons. Preferably, the halogen atom represents chlorine or bromine. The alkyl group can be a methyl group, an ethyl group, or a t-butyl group. The alkoxy group can be a methoxy group or an ethoxy group.
Specific examples of the aforementioned phenol compounds can be phenol, cresol, ethylphenol, n-propylphenol, isobutylphenol, t-butylphenol, octylphenol, nonylphenol, xylenol, methylbutylphenol, di-t-butylphenol, vinylphenol, propenyiphenol, ethynylphenol, cyclopentylphenol, cyclohexylphenol, cyclohexylcresol or the like. The phenol compounds can be used alone or in a combination of two or more.
Based on an amount of the compound having a structure of the formula (a-II-2) as 1 mole, an amount of phenol compounds is 0.5 moles to 20 moles, and preferably is 2 moles to 15 moles.
Specific examples of the aforementioned acid catalyst may be hydrochloric acid, sulfuric acid, p-toluenesulfonic acid, oxalic acid, boron trifluoride, anhydrous aluminium chloride, zinc chloride and the like. Preferably, the acid catalyst is selected from p-toluenesulfonic acid, sulfuric acid or hydrochloric acid. The acid catalyst can be used alone or in a combination of two or more.
In addition, there is no specific limitation to the amount of the acid catalyst. Preferably, based on the amount of the compound having a structure of formula (a-II-2) as 100 wt %, an amount of the acid catalyst is preferably 0.1 wt % to 30 wt %.
The aforementioned condensation reaction can be performed in the absence of solvents or in the presence of organic solvents. Specific examples of the organic solvents may be toluene, xylene, methyl isobutyl ketone or the like. The organic solvents can be used alone or in a combination of two or more.
Based on a total amount of the compound having a structure of the formula (a-II-2) and the amount of the phenol as 100 wt %, an amount of the organic solvent is 50 wt % to 300 wt %, and is preferably 100 wt % to 250 wt %. Besides, the condensation reaction is performed at 40° C. to 180° C. for 1 hour to 8 hours.
After the condensation reaction is complete, a neutralization treatment or a rinsing treatment can be performed. The neutralization treatment is to adjust the pH value of the solution to 3 to 7, and is preferably 5 to 7. The rinsing treatment is performed with a neutralizing agent, and the neutralizing agent is a basic compound, for example, alkali metal hydroxides such as sodium hydroxide, potassium hydroxide and the like; alkaline earth metal hydroxides such as calcium hydroxide, magnesium hydroxide and the like; organic amines such as diethylene triamine, triethylene tetramine, aniline, phenylene diamine and the like; and ammonia, sodium dihydrogen phosphate and other compounds. The rinsing treatment can be performed in a commonly used manner. For example, the reacted solution is repeatedly extracted by adding an aqueous solution containing the neutralizing agent. After the neutralization or rinsing treatment is complete, unreacted phenols and solvents can be removed via distillation at a reduced pressure, and then concentrated to obtain the compound having a structure of the formula (a-II-1).
An example of the aforementioned epihalohydrin may be 3-chloro-1,2-epoxypropane, 3-bromo-1,2-epoxypropane or a combination thereof. Before the aforementioned dehydrohalogenation reaction is performed, alkaline metal hydroxides such as sodium hydroxide, potassium hydroxide and the like can be added prior to or during the dehydrohalogenation reaction. The aforementioned dehydrohalogenation is performed at 20° C. to 120° C. for 1 hour to 10 hours.
In one embodiment, the alkaline metal hydroxides added in the dehydrohalogenation reaction can be an aqueous solution. In this embodiment, when the alkaline metal hydroxide aqueous solution is continuously added to a dehydrohalogenation reaction system, water and epihalohydrin can be continuously distilled at atmospheric pressure or at a reduced pressure, thereby separating and removing the water, and the epihalohydrin can be continuously refluxed into the reaction system at the same time.
Before the aforementioned dehydrohalogenation reaction is performed, quaternary ammonium salts, such as tetramethyl ammonium chloride, tetramethyl ammonium bromide, trimethyl benzyl ammonium chloride and the like can be added as a catalyst, and reacted at 50° C. to 150° C. for 1 hour to 5 hours. Then, alkaline metal hydroxide or an aqueous solution thereof is added, and the dehydrohalogenation reaction is performed at 20° C. to 120° C. for 1 hour to 10 hours.
Based on a total equivalent hydroxyl groups in the compound having a structure of the formula (a-II-1) as 1 equivalent, the amount of the epihalohydrin is 1 equivalent to 20 equivalents, and is preferably 2 equivalents to 10 equivalents. Based on the total equivalent hydroxyl groups in the compound with the structure in the formula (a-II-1) as 1 equivalent, an amount of the alkaline metal hydroxide that was added to the dehydrohalogenation reaction is 0.8 equivalents to 15 equivalents, and preferably is 0.9 equivalents to 11 equivalents.
In addition, to perform the dehydrohalogenation reaction smoothly, polar aprotic solvents such as dimethyl sulfone, dimethyl sulfoxide and the like can also be added in addition to alcohols such as methanol, ethanol and the like, to perform the reaction. When the alcohol is used, based on an amount of the epihalohydrin as 100 wt %, the amount of alcohol can be 2 wt % to 20 wt %, and is preferably 4 wt % to 15 wt %. When the polar aprotic solvent is used, based on the amount of the epihalohydrin as 100 wt %, the amount of polar aprotic solvent can be 5 wt % to 100 wt %, and is preferably 10 wt % to 90 wt %.
After the dehydrohalogenation reaction is completed, a rinse treatment can be optionally performed. Afterwards, the epihalohydrin, the alcohol, the polar aprotic solvent and the like are removed by a heating treatment at a reduced pressure. The heating treatment at the reduced pressure can be performed at 110° C. to 250° C. and a pressure less than 1.3 kPa (10 mmHg).
To prevent the formed epoxy resin from containing hydrolysable halogens, solvents such as toluene, methyl isobutyl ketone and the like, and alkali metal hydroxide solutions such as sodium hydroxide, potassium hydroxide and the like can be added to the solution after the dehydrohalogenation reaction to perform the dehydrohalogenation reaction again. During the dehydrohalogenation reaction, based on the total equivalent of hydroxyl groups in the compound having a structure of formula (a-II-1) as 1 equivalent, the amount of alkali metal hydroxide is 0.01 moles to 0.3 moles, and is preferably 0.05 moles to 0.2 moles. In addition, the dehydrohalogenation reaction is performed at 50° C. to 120° C. for 0.5 hour to 2 hours.
After the dehydrohalogenation reaction is completed, salts can be removed by performing a filtration step, a rinse step and the like. In addition, solvents such as toluene, methyl isobutyl ketone or the like can be removed by a heating treatment at a reduced pressure, thereby obtaining an epoxy compound having at least two epoxy groups (a-1-1) having a structure of formula (a-II). The aforementioned epoxy compound having at least two epoxy groups (a-1-1) having a structure of formula (a-II) can include but is not limited to commercially available products manufactured by Nippon Kayaku Co. Ltd., and the trade names are NC-3000, NC-3000H, NC-3000S, NC-3000P and the like.
In one example of the present invention, the aforementioned compound having at least one carboxyl group and at least one vinyl unsaturated group (a-1-2) of the resin having an unsaturated vinyl group (A-1) is selected from the group consisting of the following subgroups (1) to (3): (1) acrylic acid, methacrylic acid, 2-methacryloyloxyethyl butanedioic acid, 2-methacryloyloxybutyl butanedioic acid, 2-methacryloyloxyethyl hexanedioic acid, 2-methacryloyloxybutyl hexanedioic acid, 2-methacryloyloxyethyl hexahydrophthalic acid, 2-methacryloyloxyethyl maleic acid, 2-methacryloyloxypropyl maleic acid, 2-methacryloyloxybutyl maleic acid, 2-methacryloyloxypropyl butanedioic acid, 2-methacryloyloxypropyl hexanedioic acid, 2-methacryloyloxypropyl tetrahydrophthalic acid, 2-methacryloyloxypropyl phthalic acid, 2-methacryloyloxybutyl phthalic acid or 2-methacryloyloxybutyl hydrophthalic acid; (2) a compound obtained by reacting (methyl)acrylate esters having hydroxyl group(s) with a dicarboxylic acid compound, in which the dicarboxylic acid compound may include but not limited to hexanedioic acid, butanedioic acid, maleic acid, and phthalic acid; (3) a hemiester compound obtained by reacting (methyl)acrylate having hydroxyl group(s) with a carboxylic acid anhydride compound. The aforementioned (methyl)acrylate having hydroxyl group(s) may include but is not limited to (2-hydroxyethyl)acrylate, (2-hydroxyethyl)methacrylate, (2-hydroxypropyl)acrylate, (2-hydroxypropyl)methacrylate, (4-hydroxybutyl)acrylate, (4-hydroxybutyl)methacrylate, pentaerythritol triacrylate and the like. The aforementioned carboxylic acid anhydride compounds can be the same as the carboxylic anhydride compound (a-1-3) in the resin having an unsaturated group (A-1), therefore it is not repeated here.
As described above, the resin having an unsaturated group (A-1) can selectively comprise the carboxylic anhydride compound (a-1-3) and/or the epoxy compound (a-1-4). The aforementioned carboxylic anhydride compound (a-1-3) can be selected from the group consisting of the following subgroups (1) to (2): (1) dicarboxylic acid anhydride compounds such as butanedioic anhydride, maleic anhydride, itaconic anhydride, phthalic anhydride, tetrahydrophthalic anhydride, hexahydrophthalic anhydride, methyltetrahydrophthalic anhydride, methylhexahydrophthalic anhydride, methyl endo-methylene tetrahydrophthalic anhydride, chlorendic anhydride, pentanedioic anhydride, 1,3-dioxoisobenzofuran-5-carboxylic anhydride and the like; and (2) tetracarboxylic acid anhydride compounds such as benzophenone tetracarboxylic dianhydride (BTDA), diphenyl tetracarboxylic dianhydride, diphenyl ether tetracarboxylic acid dianhydride and the like.
The aforementioned compound having an epoxy group (a-1-4) can be selected from the group consisting of glycidyl methacrylate, 3,4-epoxycyclohexyl methacrylate, glycidyl ether compounds having unsaturated group(s), unsaturated compounds having epoxy group(s) or a combination thereof. The aforementioned glycidyl ether compounds having unsaturated group(s) may include but not limited to commercially available products such as Denacol EX-111, Denacol EX-121, Denacol EX-141, Denacol EX-145, Denacol EX-146, Denacol EX-171, Denacol EX-192 and the like manufactured by Nagase ChemteX Corporation.
The aforementioned resin having an unsaturated group (A-1) can be obtained by polymerization of the epoxy compound having at least two epoxy groups (a-1-1) of the formula (a-I) with the compound having at least one carboxyl group and at least one vinyl unsaturated group (a-1-2) to form a reacted product having hydroxyl group(s), and then reacting the reacted product with the carboxylic anhydride compound (a-1-3). Preferably, based on the total equivalent hydroxyl groups of the reacted product having hydroxyl group(s) as 1 equivalent, the equivalent anhydride groups in the carboxylic anhydride compound (a-1-3) is preferably 0.4 equivalents to 1 equivalent, and more preferably is 0.75 equivalents to 1 equivalent. When a plurality of the carboxylic anhydride compounds (a-1-3) is applied, it can be added sequentially or simultaneously in the reaction. Preferably, when a dicarboxylic acid anhydride compound and tetracarboxylic acid anhydride compound are used as the carboxylic anhydride compound (a-1-3), the molar ratio of the dicarboxylic acid anhydride compound and the tetracarboxylic acid anhydride compound is 1/99 to 90/10, and more preferably is 5/95 to 80/20. In addition, the aforementioned reaction can be performed at a 50° C. to 130° C.
The resin having an unsaturated group (A-1) can be obtained by reacting the epoxy compound having at least two epoxy groups (a-1-1) of the formula (a-II) with the compound having at least one carboxyl group and at least one vinyl unsaturated group (a-1-2) to form an reacted product having hydroxyl group(s), and then the reacted product is subjected to a polymerization reaction by adding the carboxylic anhydride compound (a-1-3) and/or the compound having an epoxy group (a-1-4). Preferably, based on the total equivalent epoxy groups of the epoxy compound having at least two epoxy groups (a-1-1) of formula (a-II) as 1 equivalent, the acid value equivalent of the compound having at least one carboxyl group and at least one vinyl unsaturated group (a-1-2) is preferably 0.8 equivalent to 1.5 equivalent, and more preferably is 0.9 equivalent to 1.1 equivalent. Based on the hydroxyl groups in the reacted product having hydroxyl group(s) as 100 mole %, the amount of the anhydride compound (a-1-3) is 10 mole % to 100 mole %, preferably is 20 mole % to 100 mole %, and more preferably is 30 mole % to 100 mole %.
When the aforementioned resin having an unsaturated group (A-1) is prepared, alkaline compounds are usually added to the reacting solution as a reacting catalyst to accelerate the reaction. The reacting catalyst can be used alone or in a combination of two or more. The aforementioned reacting catalyst may include but is not limited to triphenyl phosphine, triphenyl stibine, triethylamine, triethanolamine, tetramethylammonium chloride, benzyltriethylammonium chloride and the like. Preferably, based on the total amount of the epoxy compound having at least two epoxy groups (a-1-1) and the compound having at least one carboxyl group and at least one vinyl unsaturated group (a-1-2) as 100 parts by weight, the amount of the reacting catalyst is preferably 0.01 parts by weight to 10 parts by weight, and more preferably is 0.3 parts by weight to 5 parts by weight.
In addition, to control the degree of polymerization, a polymerization inhibitor is usually added into the reacting solution. The aforementioned polymerization inhibitor may include but is not limited to methoxyphenol, methylhydroquinone, hydroquinone, 2,6-di-t-butyl-p-cresol, phenothiazine and the like. The aforementioned polymerization inhibitor may be used alone or in a combination of two or more. Based on the total amount of the epoxy compound having at least two epoxy groups (a-1-1) and the compound having at least one carboxyl group and at least one vinyl unsaturated group (a-1-2) as 100 parts by weight, the amount of the polymerization inhibitor is preferably 0.01 parts by weight to 10 parts by weight, and more preferably is 0.1 parts by weight to 5 parts by weight.
When the resin having an unsaturated group (A-1) is prepared, a polymerization solvent can be used if necessary. Specific examples of the aforementioned polymerization solvent are alcohol compounds such as ethanol, propanol, isopropanol, butanol, isobutanol, 2-butanol, hexanol, ethylene glycol or the like; ketone compounds such as methyl ethyl ketone, cyclohexanone or the like; aromatic hydrocarbon compounds such as toluene, xylene or the like; cellosolve compounds such as cellosolve, butyl cellosolve or the like; carbitol compounds such as carbitol, butyl carbitol or the like; propylene glycol alkyl ether compounds such as propylene glycol monomethyl ether or the like; poly(propylene glycol) alkyl ether compounds such as di(propylene glycol) methyl ether or the like; acetate ester compounds such as ethyl acetate, butyl acetate, ethylene glycol monoethyl ether acetate, propylene glycol methyl ether acetate or the like; alkyl lactate compounds such as ethyl lactate, butyl lactate or the like; or dialkyl glycol ether compounds. The aforementioned polymerization solvent may be used alone or in a combination of two or more. Furthermore, the acid value of the resin having an unsaturated group (A-1) is preferably 50 mgKOH/g to 200 mgKOH/g, and more preferably is 60 mgKOH/g to 150 mgKOH/g.
An average weight molecular weight of the alkali-soluble resin (A-1) is generally 1,200 to 15,000, preferably is 1,500 to 13,000, and more preferably is 1,800 to 10,000.
Based on the alkali-soluble resin (A) as 100 parts by weight, the amount of the aforementioned resin having an unsaturated group (A-1) is 30 parts by weight to 100 parts by weight, preferably is 50 parts by weight to 100 parts by weight, and more preferably is 70 parts by weight to 100 parts by weight. If the alkali-soluble resin (A) of the photosensitive resin composition contains the resin having an unsaturated group (A-1), the refractivity of the photosensitive resin composition can be improved.
Though not willing to be limited by a theory, it is believed that the refractivity is proportional to polarity of a molecule. An aromatic ring has a molecule structure with high polarity, thus the refractivity of the resin having an unsaturated group (A-1) may be increased due to the aromatic ring structure.
Alkali-Soluble Resins (A-2)
Preferably, the alkali-soluble resin (A) includes alkali-soluble resin (A-2).
A term of “(meth)acrylic acid” used in the present invention represents acrylic acid and/or methacrylic acid; a term of “(meth)acryloyl” represents acryloyl and/or methacryloyl; a term of “(meth)acrylate” represents acrylate and/or methacrylate.
The alkali-soluble resin (A-2) is a resin that can be soluble in an alkaline aqueous solution without being limited to any specific structure. Preferably, the alkali-soluble resin (A-2) is a resin containing a carboxylic group, a phenol-novolac resin and the like. More preferably, the alkali-soluble resin (A) is copolymerized from a compound (a1) of unsaturated carboxylic acid or unsaturated carboxylic anhydride, an unsaturated compound containing epoxy group(s) (a2) and/or other unsaturated compounds (a3) in a solvent in the presence of an appropriate polymerization initiator.
When the alkali-soluble resin (A-2) is copolymerized from the compound (a1) of unsaturated carboxylic acid or unsaturated carboxylic anhydride, the unsaturated compound containing epoxy group(s) (a2) and/or other unsaturated compounds (a3), based on an amount of the compounds used to polymerize the alkali-soluble resin (A-2) as 100 parts by weight, an amount of the compound (a1) of unsaturated carboxylic acid or unsaturated carboxylic anhydride is 5 parts by weight to 50 parts by weight, preferably is 8 parts by weight to 45 parts by weight, and more preferably is 10 parts by weight to 40 parts by weight. The compound (a1) of unsaturated carboxylic acid or unsaturated carboxylic anhydride refers to a compound containing the structure of carboxylic acid or carboxylic anhydride and unsaturated polymerizable bonds without being limited to any specific structure. For example, the compound can be an unsaturated monocarboxylic acid compound, an unsaturated dicarboxylic acid compound, an unsaturated acid anhydride compound, an unsaturated polycyclic carboxylic acid compound, an unsaturated polycyclic dicarboxylic acid compound and an unsaturated polycyclic acid anhydride compound.
Specific examples of the aforementioned unsaturated monocarboxylic acid compound can be (meth)acrylic acid, butenoic acid, α-chloroacrylic acid, ethyl acrylic acid, cinnamic acid, 2-(meth)acryloyloxyethyl succinate monoester, 2-(meth)acryloyloxyethyl hexahydrophthalate, 2-(meth)acryloyloxyethyl phthalate and omega-carboxyl polycaprolactone polyol monoacrylate (a trade name of ARONIX M-5300, manufactured by Toagosei Co., Ltd.).
Specific examples of the aforementioned unsaturated dicarboxylic acid compound are maleic acid, fumaric acid, mesaconic acid, itaconic acid and traconic acid. In an example of the present invention, the unsaturated dicarboxylic acid anhydride compound is the anhydride compound of the aforementioned unsaturated dicarboxylic acid compound.
Specific examples of the aforementioned unsaturated polycyclic carboxylic acid compound can be 5-carboxyl bicyclo[2.2.1]hept-2-ene, 5-carboxyl-5-methylbicyclo [2.2.1]hept-2-ene, 5-carboxyl-5-ethylbicyclo[2.2.2.1]hept-2-ene, 5-carboxyl-6-methylbicyclo [2.2.1]hept-2-ene and 5-carboxyl-6-ethylbicyclo[2.2.1]hept-2-ene.
A specific example of the aforementioned unsaturated polycyclic dicarboxylic acid compound can be 5,6-dicarboxylic bicyclo[2.2.1]hept-2-ene. The aforementioned unsaturated polycyclic dicarboxylic acid anhydride compound is the anhydride compound of the aforementioned unsaturated polycyclic dicarboxylic acid compound.
Preferably, the examples of the aforementioned compound (a1) of unsaturated carboxylic acid or unsaturated carboxylic anhydride are acrylic acid, methacrylic acid, maleic anhydride, 2-methacryloyloxyethyl succinate monoester and 2-methacryloyloxyethyl hexahydrophthalic acid. The compound (a1) of unsaturated carboxylic acid or unsaturated carboxylic anhydride can be used alone or in a combination of two or more.
Based on the amount of the compound used to polymerize the alkali-soluble resin (A-2) as 100 parts by weight, an amount of the unsaturated compound containing epoxy group(s) (a2) is 10 parts by weight to 50 parts by weight, preferably is 12 parts by weight to 45 parts by weight, and more preferably is 15 parts by weight to 40 parts by weight. Specific examples of the unsaturated compound containing epoxy group(s) (a2) may be (meth)acrylate compounds containing epoxy group(s), α-alkyl acrylate compounds containing epoxy group(s) and glycidyl ether compounds.
Specific examples of the (meth)acrylate containing epoxy group(s) may be glycidyl (meth)acrylate, 2-methylglycidyl (meth)acrylate, 3,4-epoxybutyl (meth)acrylate, 6,7-epoxyheptyl (meth)acrylate, 3,4-epoxycyclohexyl (meth)acrylate and 3,4-epoxycyclohexylmethyl (meth)acrylate.
Specific examples of the α-alkyl acrylate compounds containing epoxy group(s) may be glycidyl α-ethylacrylate, glycidyl α-n-propylacrylate, glycidyl α-n-butylacrylate and 6,7-epoxyheptyl α-ethylacrylate.
Specific examples of the glycidyl ether compounds may be o-vinylbenzylglycidylether, m-vinylbenzylglycidylether and p-vinylbenzylglycidylether.
Preferably, the examples of the unsaturated compound containing epoxy group(s) (a2) may be glycidyl methacylate, 3,4-epoxycyclohexylmethyl (meth)acrylate, 6,7-epoxyheptyl methaacrylate, o-vinylbenzylglycidylether, m-vinylbenzylglycidylether and p-vinylbenzylglycidylether.
Based on the amount of the compounds used to polymerize the alkali-soluble resin (A-2) as 100 parts by weight, an amount of the other unsaturated compounds (a3) is 0 parts by weight to 85 parts by weight, preferably is 10 parts by weight to 80 parts by weight, and more preferably is 20 parts by weight to 75 parts by weight. Specific examples of the other unsaturated compounds (a3) may be alkyl (meth)acrylate, alicyclic (meth)acrylate, aryl (meth)acrylate, unsaturated dicarboxylic diester, hydroxyalkyl (meth)acrylate, polyether of (meth)acrylate, aromatic vinyl compounds and other unsaturated compounds.
Specific examples of the alkyl (meth)acrylate may be methyl (meth)acrylate, ethyl (meth)acrylate, n-propyl (meth)acrylate, iso-propyl (meth)acrylate, n-butyl (meth)acrylate, iso-butyl (meth)acrylate, sec-butyl (meth)acrylate and tert-butyl (meth)acrylate.
Specific examples of the alicyclic (meth)acrylate may be cyclohexyl (meth)acrylate, 2-methylcyclohexyl (meth)acrylate, tricyclic[5.2.1.02,6]deca-8-yl (meth)acrylic ester (or referred to as dicyclopentanyl (meth)acrylate), dicycopentyloxyethyl (meth)acrylate, isobornyl (meth)acrylate and tetrahydrofuranyl (meth)acrylate.
Specific examples of the aryl (meth)acrylate may be phenyl (meth)acrylate and benzyl (meth)acrylate.
Specific examples of the unsaturated dicarboxylic diester may be diethyl maleate, diethyl fumarate and diethyl itaconate.
Specific examples of the hydroxyalkyl (meth)acrylate may be 2-hydroxyethyl (meth)acrylate and 2-hydroxypropyl (meth)acrylate.
Specific examples of the polyether of (meth)acrylate may be polyethylene glycol mono(meth)acrylate and polypropylene glycol mono(meth)acrylate.
Specific examples of the aromatic vinyl compounds may be styrene monomer, α-methylstyrene, m-methylstyrene, p-methylstyrene and p-methoxy styrene.
Specific examples of the other unsaturated compounds may be acrylonitrile, methacrylonitrile, chloroethylene, vinylidene chloride, acrylamide, methacrylamide, vinyl acetate, 1,3-butadiene, isoprene, 2,3-dimethyl 1,3-butadiene, N-cyclohexyl maleimide, N-phenyl maleimide, N-benzyl maleimide, N-succinimide-3-maleimidobenzoic ester, N-succimide-4-maleimidobutyric ester, N-succinimide-6-maleimidocaproate, N-succinimide-3-maleimido propionic ester and N-(9-acridinyl) maleimide.
Preferably, the examples of the other unsaturated compounds (a3) are methyl (meth)acrylate, butyl (meth)acrylate, 2-hydroxyethyl (meth)acrylate, tert-butyl (meth)acrylate, benzyl (meth)acrylate, dicyclopentyl (meth)acrylate, dicyclopentyloxyethyl (meth)acrylate, styrene and p-methoxy styrene. The other unsaturated compounds (a3) can be used alone or in a combination of two or more.
Specific examples of a solvent used during manufacturing the alkali-soluble resin (A-2) of the present invention may be alcohol, ether, glycol ether, ethylene glycol monoalkyl ether acetate, diethylene glycol, dipropylene glycol, propylene glycol monoalkyl ether, propylene glycol monoalkyl ether acetate, propylene glycol monoalkyl ether propionate, aromatic hydrocarbon, ketone and ester.
Specific examples of the alcohol are methanol, ethanol, phenylcarbinol, 2-phenylethanol and 3-phenyl-1-propanol.
Specific example of the ether is tetrahydrofuran.
Specific examples of the glycol ether are ethylene glycol monopropyl ether, ethylene glycol monomethyl ether and ethylene glycol monoethyl ether.
Specific examples of the ethylene glycol monoalkyl ether acetate are ethylene glycol monobutyl ether acetate, ethylene glycol monoethyl ether acetate and ethylene glycol monomethyl ether acetate.
Specific examples of the diethylene glycol are diethylene glycol monomethyl ether, diethylene glycol monoethyl ether and diethylene glycol monobutyl ether, diethylene glycol dimethyl ether, diethylene glycol diethyl ether and diethylene glycol methyl ethyl ether.
Specific examples of the dipropylene glycol are dipropylene glycol monomethyl ether, dipropylene glycol monoethyl ether, dipropylene glycol dimethyl ether, dipropylene glycol diethyl ether and dipropylene glycol methyl ethyl ether.
Specific examples of the propylene glycol monoalkyl ether are propylene glycol monomethyl ether, propylene glycol monoethyl ether, propylene glycol monopropyl ether and propylene glycol monobutyl ether.
Specific examples of the propylene glycol monoalkyl ether acetate are propylene glycol methyl ether acetate, propylene glycol ethyl ether acetate, propylene glycol propyl ether acetate and propylene glycol butyl ether acetate.
Specific examples of the propylene glycol alkyl ether propionate are propylene glycol methyl ether propionate, propylene glycol ethyl ether propionate, propylene glycol propyl ether propionate and propylene glycol butyl ether propionate.
Specific examples of the aromatic hydrocarbon are methylbenzene and dimethylbenzene.
Specific examples of the ketone are ethyl methyl ketone, cyclohexanone and diacetone alcohol.
Specific examples of the ester are methyl acetate, ethyl acetate, propyl acetate, butyl acetate, ethyl 2-hydroxypropionate, methyl 2-hydroxy-2-methpropionate, ethyl 2-hydroxy-2-methpropionate, methyl glycolate, ethyl glycolate, butyl glycolate, methyl lactate, propyl lactate, butyl lactate, methyl 3-hydroxypropionate, ethyl 3-hydroxypropionate, propyl 3-hydroxypropionate, butyl 3-hydroxypropionate, methyl 2-hydroxy-3-methbutyrate, methyl methoxyacetate, ethyl methoxyacetate, butyl methoxyacetate, methyl ethoxyacetate, ethyl ethoxyacetate, propyl ethoxyacetate, butyl ethoxyacetate, methyl propoxyacetate, ethyl propoxyacetate, propyl propoxyacetate, butyl propoxyacetate, methyl butoxyacetate, ethyl butoxyacetate, propyl butoxyacetate, butyl butoxyacetate, 3-methoxybutyl acetate, methyl 2-methoxypropionate, ethyl 2-methoxypropionate, propyl 2-methoxypropionate, butyl 2-methoxypropionate, methyl 2-ethoxypropionate, ethyl 2-ethoxypropionate, propyl 2-ethoxypropionate, butyl 2-ethoxypropionate, methyl 2-butoxypropionate, ethyl 2-butoxypropionate, propyl 2-butoxypropionate, butyl 2-butoxypropionate, methyl 3-methoxypropionate, ethyl 3-methoxypropionate, propyl 3-methoxypropionate, butyl 3-methoxypropionate, methyl 3-ethoxypropionate, ethyl 3-ethoxypropionate, propyl 3-ethoxypropionate, butyl 3-ethoxypropionate, methyl 3-propoxylpropionate, ethyl 3-propoxylpropionate, propyl 3-propoxylpropionate, butyl 3-propoxylpropionate, methyl 3-butoxypropionate, ethyl 3-butoxypropionate, propyl 3-butoxypropionate and butyl 3-butoxypropionate.
Preferably, the examples of the solvent used for manufacturing the alkali-soluble resin (A-2) of the present invention are diethylene glycol dimethyl ether and propylene glycol monomethyl ether acetate. The aforementioned solvent can be used alone or in a combination of two or more.
A polymerizing initiator can be used during the process of manufacturing the alkali-soluble resin (A-2) of the present invention. Specific examples of the polymerizing initiator are azo compounds or peroxides.
Specific examples of the azo compounds are 2,2′-azobis(isobutyronitrile), 2,2′-azobis(2,4-dimethylvaleronitrile), 2,2′-azobis(4-methoxy-2,4-dimethylvaleronitrile), 2,2′-azobis(2-methyl butyronitrile), 4,4′-azobis(4-cyano valeric acid), 2,2′-azobis(dimethyl-2-methylpropionate) and 2,2′-azobis(4-methoxy-2,4-dimethylvaleronitrile).
Specific examples of the peroxides are dibenzoyl peroxide, dilauroyl peroxide, tert-butyl peroxypivalate, 1,1-di(tert-butylperoxy)cyclohexane and hydrogen peroxide.
The polymerizing initiators can be used alone or in a combination of two or more.
A weight average molecular weight of the alkali-soluble resin (A-2) of the present invention is generally 3,000 to 100,000, preferably is 4,000 to 80,000, and more preferably is 5,000 to 60,000. The weight average molecular weight of the alkali-soluble resin (A-2) of the present invention can be adjusted by using a single resin or using two or more resins with different molecular weights synergistically.
Based on the amount of the alkali-soluble resin (A) as 100 parts by weight, the amount of the alkali-soluble resin (A-2) is 0 to 70 parts by weight, preferably is 0 to 50 parts by weight, and more preferably is 0 to 30 parts by weight.
Compound Having a Vinyl Unsaturated Group (B)
The compound having a vinyl unsaturated group (B) described herein can include a compound (B-1) having a structure of formula (b-II) or formula (b-II), and other compounds having a vinyl unsaturated groups (B-2).
Compound (B-1)
The compound (B-1) includes the structure of the formula (b-I) and/or the formula (b-II):
in the formula (b-I), R 21 and R 22 individually and independently represent a hydrogen atom and a methyl group, p represents a number of 0 to 4.
in the formula (b-II), R 23 and R 24 individually and independently represent a hydrogen atom and a methyl group, m represents a number of 0 to 4.
The p and the m in the formula (b-I) and the formula (b-II) represent an average number of addition of an alkoxyl group per molecule.
Specific examples of the aforementioned compound (B-1) having the structure of the formula (b-I) can be p-(isopropylphenyl)phenyl (meth)acrylate and p-(isopropylphenylphenoxy) ethyl (meth)acrylate, and is preferably p-isopropylphenylphenoxy ethyl (meth)acrylate.
Specific examples of the aforementioned compound (B-1) having the structure of the formula (b-II) can be o-phenylphenyl(meth)acrylate, m-phenylphenyl(meth)acrylate, p-phenylphenyl(meth)acrylate, o-phenylphenoxy ethyl (meth)acrylate, m-phenylphenoxy ethyl (meth)acrylate and p-phenylphenoxy ethyl (meth)acrylate, preferably are o-phenylphenyl(meth)acrylate and o-phenylphenoxy ethyl (meth)acrylate.
Based on the amount of the alkali-soluble resin (A) as 100 parts by weight, the amount of the compound (B-1) is 15 parts by weight to 100 parts by weight, preferably is 20 parts by weight to 90 parts by weight, and more preferably is 25 parts by weight to 80 parts by weight. If the photosensitive resin composition includes the compound (B-1), the refractivity and adhesivity to Mo of the film formed by the photosensitive resin composition can be further improved.
Though not willing to be limited by a theory, it is believed that due to having an aromatic structure, the compound (B-1) has a better refractivity. In addition, the compound (B-1) has a steric structure, thus a shrinkage rate and strain inside the film are lowered down, and the compound (B-1) has better adhesivity to Mo.
Other Compound Having a Vinyl Unsaturated Group (B-2)
The compound having the vinyl unsaturated group (B) of the present invention can include other compounds having the vinyl unsaturated group (B-2), which is selected from a compound having a vinyl unsaturated group or a compound having at least two (including two) vinyl unsaturated groups.
The compound having a vinyl unsaturated group can include but is not limited to (meth)acryloyl morpholine, 7-amino-3,7-dimethyloctylamine (meth)acrylate, isobutoxymethyl (meth)acrylamide, isobornyloxyethyl (meth)acrylate, isobornyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, ethyl diethylene glycol (meth)acrylate, tert-octyl (meth)acrylamide, dipropyl ketone (meth)acrylate, (dimethylamino)ethyl (meth)acrylate, dodecyl (meth)acrylate, dicyclopentenyloxyethyl (meth)acrylate, dicyclopentenyl (meth)acrylate, N,N-dimethyl (meth)acrylamide, tetrachlorobenzene (meth)acrylate, 2-tetrachlorophenoxylethyl (meth)acrylate, tetrahydrofurfuryl (meth)acrylate, tetrabromobenzene (meth)acrylate, 2-tetrabromophenoxylethyl (meth)acrylate, 2-trichlorophenoxylethyl (meth)acrylate, tribromobenzene (meth)acrylate, 2-tribromophenoxylethyl (meth)acrylate, 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, vinylcaprolactam, N-vinyl pyrrolidone, phenoxyethyl (meth)acrylate, pentachlorobenzene (meth)acrylate, pentabromobenzene (meth)acrylate, glycerol polymono(meth)acrylate, propanediol polymono(meth)acrylate, borneol (meth)acrylate. The compound having a vinyl unsaturated group can be used alone or in a combination of two or more.
The aforementioned compound having at least two vinyl unsaturated groups can include but is not limited to diethylene glycol di(meth)acrylate, dicyclopentene di(meth)acrylate, triethylene glycol di(meth)acrylate, tetraethylene glycol di(meth)acrylate, tri(2-hydroxyethyl)isocyanate di(meth)acrylate, tri(2-hydroxyethyl)isocyanate tri(meth)acrylate, caprolactone modified tri(2-hydroxyethyl)isocyanate tri(meth)acrylate, trihydroxymethylpropyl tri(meth)acrylate, ethylene oxide (hereinafter abbreviated as EO) modified trihydroxymethylpropyl tri(meth)acrylate, propylene oxide (hereinafter abbreviated as PO) modified trihydroxymethylpropyl tri(meth)acrylate, tri(propylene glycol) di(meth)acrylate, neopentyl glycol di(meth)acrylate, 1,4-butanediol di(meth)acrylate, 1,6-hexanediol di(meth)acrylate, pentaerythritol tri(meth)acrylate, pentaerythritol tetra(meth)acrylate, polyester di(meth)acrylate, polyethylene glycol di(meth)acrylate, dipentaerythritol hexa(meth)acrylate, dipentaerythritol penta(meth)acrylate, dipentaerythritol tetra(meth)acrylate, EO modified dipentaerythritol hexa(meth)acrylate, EO modified dipentaerythritol penta(meth)acrylate, di(trimethylolpropane) tetra(meth)acrylate, EO modified bisphenol A di(meth)acrylate, PO modified bisphenol A di(meth)acrylate, EO modified hydrogenated bisphenol A di(meth)acrylate, PO modified hydrogenated bisphenol A di(meth)acrylate, PO modified glycerol triacrylate, EO modified bisphenol F di(meth)acrylate, phenolic polyglycidyl ether (meth)acrylate. The aforementioned compound having at least two vinyl unsaturated groups can be used alone or in a combination of two or more.
Based on the amount of the alkali-soluble resin (A) as 100 parts by weight, an amount of the compound having the vinyl unsaturated group (B) is 15 parts by weight to 300 parts by weight, preferably is 25 parts by weight to 280 parts by weight, and more preferably is 40 parts by weight to 250 parts by weight.
Photoinitiator (C)
The photoinitiator (C) of the present invention is subjected to no specific limitation, and an example of the photoinitiator (C) of the present invention can include but is not limited to O-acyloxime photoinitiators, triazine photoinitiators, acetophenone compounds, biimidazole compounds, benzophenone compounds, a-diketone compounds, ketol compounds, ketol ether compounds, acyl phosphine oxide compounds, quinone compounds, compounds containing halogens and peroxides. The following describes in detail.
Specific examples of the aforementioned O-acyloxime photoinitiators are 1-[4-(phenylthio)phenyl]-heptane-1,2-diketone 2-(O-benzoyloxime), 1-[4-(phenylthio)phenyl]-octane-1,2-diketone 2-(O-benzoyloxime), 1-[4-(benzoyl)phenyl]-heptane-1,2-diketone 2-(O-benzoyloxime), 1-[9-ethyl-6-(2-methylbenzoyl)-9H-carbazole-3-yl]-ethyl ketone 1-(O-acetaldoxime), 1-[9-ethyl-6-(3-methylbenzoyl)-9H-carbazole-3-yl]-ethyl ketone 1-(O-acetaldoxime), 1-[9-ethyl-6-benzoyl-9H-carbazole-3-yl]-ethyl ketone 1-(O-acetaldoxime), ethyl ketone-1-[9-ethyl-6-(2-methyl-4-tetrahydrofuranylbenzoyl)-9H-carbazole-3-yl]-1-(O-acetaldoxime), ethyl ketone-1-[9-ethyl-6-(2-methyl-4-tetrahydropyranylbenzoyl)-9H-carbazole-3-yl]-1-(O-acetaldoxime), ethyl ketone-1-[9-ethyl-6-(2-methyl-5-tetrahydrofuranylbenzoyl)-9H-carbazole-3-yl]-1-(O-acetaldoxime), ethyl ketone-1-[9-ethyl-6-(2-methyl-5-tetrahydropyranylbenzoyl)-9H-carbazole-3-yl]-1-(O-acetaldoxime), ethyl ketone-1-[9-ethyl-6-(2-methyl-4-methoxytetrahydrofuranylmethoxybenzoyl)-9H-carbazole-3-yl]-1-(O-acetaldoxime), ethyl ketone-1-[9-ethyl-6-(2-methyl-4-methoxytetrahydropyranylmethoxybenzoyl)-9H-carbazole-3-yl]-1-(O-acetaldoxime), ethyl ketone-1-[9-ethyl-6-(2-methyl-5-methoxytetrahydrofuranytmethoxybenzoyl)-9H-carbazole-3-yl]-1-(O-acetaldoxime), ethyl ketone-1-[9-ethyl-6-(2-methyl-5-methoxytetrahydropyranylmethoxybenzoyl)-9H-carbazole-3-yl]-1-(O-acetaldoxime), ethyl ketone-1-[9-ethyl-6-{2-methyl-4-(2,2-dimethyl-1,3-dioxolan)benzoyl}-9H-carbazole-3-yl]-1-(o-acetaldoxime) and ethyl ketone-1-[9-ethyl-6-{2-methyl-4-(2,2-dimethyl-1,3-dioxolan)methoxybenzoyl}-9H-carbazole-3-yl]-1-(O-acetaldoxime).
Preferably, the aforementioned O-acyloxime photoinitiators are 1-[4-(phenylthio)phenyl]-octane-1,2-diketone 2-(o-benzoyloxime) (e.g. trade name of OXE 01, manufactured by Ciba Specialty Chemicals Co.), 1-[9-ethyl-6-(2-benzoylmethylbenzoyl)-9H-carbazole-3-yl]-ethyl ketone 1-(O-acetaldoxime) (e.g. trade name of OXE 02, manufactured by Ciba Specialty Chemicals Co.), ethyl ketone-1-[9-ethyl-6-(2-methyl-4-tetrahydrofuranmethoxybenzoyl)-9H-carbazole-3-yl]-1-(O-acetaldoxime) and ethyl ketone-1-[9-ethyl-6-{2-methyl-4-(2,2-dimethyl-1,3-dioxolan)methoxybenzoyl}-9H-carbazole-3-yl]-1-(O-acetaldoxime). The aforementioned O-acyloxime photoinitiators can be used alone or in a combination of two or more.
Specific examples of the triazine photoinitiator of the present invention are vinyl-halomethyl-s-triazine compounds, 2-(naphtho-1-yl)-4,6-bis-halomethyl-s-triazine compounds and 4-(p-aminophenyl)-2,6-bis-halomethyl-s-triazine compounds.
Specific examples of the vinyl-halomethyl-s-triazine compound are 2,4-bis(trichloromethyl)-6-p-methoxy styrene-s-triazine, 2,4-bis(trichloromethyl)-3-(1-p-dimethylaminophenyl-1,3-butadienyl)-s-triazine and 2-trichloromethyl-3-amino-6-p-methoxy styrene-s-triazine.
Specific examples of the 2-(naphtho-1-yl)-4,6-bis-halomethyl-s-triazine compound are 2-(naphtho-1-yl)-4,6-bis-trichloromethyl-s-triazine, 2-(4-methoxy-naphtho-1-yl)-4,6-bis-trichloromethyl-s triazine, 2-(4-ethoxy-naphtho-1-yl)-4,6-bis-trichloromethyl-s-triazine, 2-(4-butoxy-naphtho-1-yl)-4,6-bis-trichloromethyl-s-triazine, 2-[4-(2-methoxyethyl)-naphtho-1-yl]-4,6-bis-trichloromethyl-s-triazine, 2-[4-(2-ethoxyethyl)naphtho-1-yl]-4,6-bis-trichloromethyl-s-triazine, 2-[4-(2-butoxyethyl)-naphtho-1-yl]-4,6-bis-trichloromethyl-s-triazine, 2-(2-methoxy-naphtho-1-yl)-4,6-bis-trichloromethyl-s-triazine, 2-(6-methoxy-5-methyl-naphtho-2-yl)-4,6-bis-trichloromethyl-s-triazine, 2-(6-methoxy-naphtho-2-yl)-4,6-bis-trichloromethyl-s-triazine, 2-(5-methoxy-naphtho-1-yl)-4,6-bis-trichloromethyl-s-triazine, 2-(4,7-dimethoxy-naphtho-1-yl)-4,6-bis-trichloromethyl-s-triazine, 2-(6-methoxy-naphtho-2-yl)-4,6-bis-trichloromethyl-s-triazine and 2-(4,5-dimethoxy-naphtho-1-yl)-4,6-bis-trichloromethyl-s-triazine.
Specific examples of the 4-(p-aminophenyl)-2,6-di-halomethyl-s-triazine are 4-[p-N,N-di(ethoxycarbonylmethyl)aminophenyl]-2,6-bis(trichloromethyl)-s-triazine, 4-[o-methyl-p-N,N-di(ethoxycarbonylmethyl)aminophenyl]-2,6-bis(trichloromethyl)-s-triazine, 4-[p-N,N-di(chloroethyl)aminophenyl]-2,6-bis(trichloromethyl)-s-triazine, 4-[o-methyl-p-N,N-di(chloroethyl)aminophenyl]-2,6-bis(trichloromethyl)-s-triazine, 4-(p-N-chloroethylaminophenyl)-2,6-bis(trichloromethyl)-s-triazine, 4-(p-N-ethoxycarbonylmethylaminophenyl)-2,6-bis(trichloromethyl)-s-triazine, 4-[p-N,N-di(phenyl)aminophenyl]-2,6-bis(trichloromethyl)-s-triazine, 4-(p-N-choroethylcarbonyaminophenyl)-2,6-bis(trichloromethyl)-s-triazine, 4-[p-N-(p-methoxyphenyl)carbonylaminophenyl-2,6-bis(trichloromethyl)-s-triazine, 4-m-N,N-di(ethoxycarbonylmethyl)aminophenyl]-2,6-bis(trichloromethyl)-s-triazine, 4-[m-bromo-p-N,N-di(ethoxycarbonylmethyl)aminophenyl]-2,6-bis(trichloromethyl)-s-triazine, 4-[m-chloro-p-N,N-di(ethoxycarbonylmethyl)aminophenyl]-2,6-bis(trichloromethyl)-s-triazine, 4-[m-fluoro-p-N,N-di(ethoxycarbonylmethyl)aminophenyl]-2,6-bis(trichloromethyl)-s-triazine, 4-[o-bromo-p-N, N-di(ethoxycarbonylmethyl)aminophenyl]-2,6-bis(trichloromethyl)-s-triazine, 4-[o-chloro-p-N, N-di(ethoxycarbonylmethyl)aminophenyl]-2,6-bis(trichloromethyl)-s-triazine, 4-[o-fluoro-p-N,N-di(ethoxycarbonylmethyl)aminophenyl]-2,6-bis(trichloromethyl)-s-triazine, 4-[o-bromo-p-N,N-di(chloroethyl)aminophenyl]-2,6-bis(trichloromethyl) s-triazine, 4-[o-chloro-p-N,N-di(chloromethyl)aminophenyl]-2,6-bis(trichloromethyl)-s-triazine, 4-[o-fluoro-p-N,N-di(chloroethyl)aminophenyl]-2,6-bis(trichloromethyl)-s-triazine, 4-[m-bromo-p-N,N-di(chloroethyl)aminophenyl]-2,6-bis(trichloromethyl)-s-triazine, 4-[m-chloro-N,N-di(chloroethyl)aminophenyl]-2,6-bis(trichloromethyl)-s-triazine 4-[m-fluoro-p-N,N-di(chloroethyl)aminophenyl]-2,6-bis(trichloromethyl)-s-triazine, 4-(m-bromo-p-N-ethoxycarbonylmethylaminophenyl)-2,6-bis(trichloromethyl)-s-triazine, 4-(m-chloro-p-N-ethoxycarbonylmethylaminophenyl)-2,6-bis(trichloromethyl)-s-triazine, 4-(m-fluoro-p-N-ethoxycarbonylmethylaminophenyl)-2,6-bis(trichloromethyl)-s-triazine, 4-(m-bromo-p-N-ethoxycarbonylmethylaminophenyl)-2,6-bis(trichloromethyl)-s-triazine, 4-(m-chloro-p-N-ethoxycarbonylmethylaminophenyl)-2,6-bis(trichloromethyl)-s-triazine, 4-(m-fluoro-p-N-ethoxycarbonylmethylaminophenyl)-2,6-bis(trichloromethyl)-s-triazine 4-(o-bromo-p-N-ethoxycarbonylmethylaminophenyl)-2,6-bis(trichloromethyl)-s-triazine, 4-(o-chloro-p-N-carbonylethoxycarbonylmethylaminophenyl)-2,6-bis(trichloromethyl)-s-triazine, 4-(o-fluoro-p-N-carbonylethoxycarbonylmethylaminophenyl)-2,6-bis(trichloromethyl)-s-triazine, 4-(m-bromo-p-N-chloroethylaminophenyl)-2,6-bis(trichloromethyl)-s-triazine, 4-(m-chloro-p-N-chloroethylaminophenyl)-2,6-bis(trichloromethyl)-s-triazine, 4-(m-fluoro-p-N-chloroethylaminophenyl)-2,6-bis(trichloromethyl)-s-triazine, 4-(o-bromo-p-N-chloroethylaminophenyl)-2,6-bis(trichloromethyl)-s-triazine, 4-(o-chloro-p-N-chloroethylaminophenyl)-2,6-bis(trichloromethyl)-s-triazine, 4-(o-fluoro-p-N-chloroethylaminophenyl)-2,6-bis(trichloromethyl)-s-triazine and 2,4-bis(trichloromethyl)-6-[3-bromo-4-[N,N-di(ethoxycarbonylmethyl)amido]phenyl]-1,3,5-triazine.
Preferably, the 4-(p-aminophenyl)-2,6-di-halomethyl-s-triazine compounds are 4-[m-bromo-p-N,N-di(ethoxycarbonylmethyl)aminophenyl]-2,6-di(chlorotrichloromethyl)-s-triazine and 2,4-bis(chlorotrichloromethyl)-6-p-methoxy styrene-s-triazine. Depending on requirements of the manufacturing process, the 4-(p-aminophenyl)-2,6-di-halomethyl-s-triazine compounds can be used alone or in a combination of two or more.
Specific examples of the acetophenone compounds are p-dimethylamine acetophenone, α,α′-dimethoxy azoxy acetophenone, 2,2′-dimethyl-2-phenyl acetophenone, p-methoxy acetophenone, 2-methyl-1-[4-(methylthio)phenyl]-2-morpholino-1-propanone and 2-benzyl-2-N,N-dimethylamine-1-(4-morpholinophenyl)-1-butanone. Preferably, the acetophenone compounds are 2-methyl-1-[4-(methylthio)phenyl]-2-morpholino-1-propanone and 2-benzyl-2-N,N-dimethylamine-1-(4-morpholinophenyl)-1-butanone.
Depending on requirements of the manufacturing process, the acetophenone compounds can be used alone or in a combination of two or more.
Specific examples of the biimidazole compounds are 2,2′-bis(o-chlorophenyl)-4,4′,5,5′-tetraphenylbiimidazole, 2,2′-bis(o-fluorophenyl)-4,4′,5,5′-tetraphenylbiimidazole, 2,2′-bis(o-methylphenyl)-4,4′,5,5′-tetraphenylbiimidazole, 2,2′-bis(o-methoxyphenyl)-4,4′,5,5′-tetraphenylbiimidazole, 2,2′-bis(o-ethylphenyl)-4,4′,5,5′-tetraphenylbiimidazole, 2,2′-bis(p-methoxyphenyl)-4,4′,5,5′-tetraphenylbiimidazole, 2,2′-bis(2,2′,4,4′-tetramethoxyphenyl)-4,4′,5,5′-tetraphenylbiimidazole and 2,2′-bis(2-chlorophenyl)-4,4′,5,5′-tetraphenylbiimidazole, 2,2′-bis(2,4-dichlorophenyl)-4,4′,5,5′-tetraphenylbiimidazole. Preferably, the biimidazole compound is 2,2′-bis(2,4-dichlorophenyl)-4,4′,5,5′-tetraphenylbiimidazole. Depending on requirements of the manufacturing process, the biimidazole compounds can be used alone or in a combination of two or more.
Specific examples of the benzophenone compounds are thioxanthone, 2,4-diethylthioxanthone, thioxanthone-4-sulphone, benzophenone, 4,4′-bis(dimethylamine) benzophenone and 4,4′-bis(diethylamino) benzophenone. Preferably, the benzophenone compound is 4,4′-bis(diethylamino) benzophenone. Depending on requirements of the manufacturing process, the benzophenone compounds can be used alone or in a combination of two or more.
Specific examples of the α-diketone compounds are benzil, diacetyl; a specific example of the ketol compound is benzoin; specific examples of the ketol ether compounds are benzoin methyl ether, benzoin ethyl ether and benzoin isopropyl ether; specific examples of the acyl phosphine oxide compounds are 2,4,6-trimethylbenzoyl diphenylphosphine oxide and bis-(2,6-dimethoxybenzoyl)-2,4,4-trimethylphenyl phosphine oxide; specific examples of the quinone compounds are anthraquinone and 1,4-naphthoquinone; specific examples of the compounds containing halogens are phenacyl chloride, tribromomethyl phenyl sulfone and tri(trichloromethyl)-s-triazine; and a specific example of the peroxide is bis-tert-butyl peroxide. Depending on requirements of the manufacturing process, the aforementioned α-diketone compounds, ketol compound, ketol ether compounds, acyl phosphine oxide compounds, quinone compounds, the compounds containing halogens and peroxides can be used alone or in a combination of two or more.
An amount of the photoinitiator (C) can be adjusted depending on the desired requirement. In a specific example of the present invention, based on the amount of the alkali-soluble resin (A) as 100 parts by weight, an amount of the photoinitiator (C) is 10 parts by weight to 100 parts by weight, preferably is 12 parts by weight to 90 parts by weight, and more preferably is 15 parts by weight to 80 parts by weight.
Solvent (D)
The solvent (D) of the present invention can be dissolved completely with other organic compositions, and has high volatility so that the solvent (D) can be evaporated from the dispersion liquid with little heat under normal pressure. Therefore, a solvent with a boiling point below 150° C. under normal pressure is mostly used. The solvent (D) includes aromatics, such as benzene, methylbenzene and dimethylbenzene; alcohols, such as methanol and ethanol; ethers, such as ethylene glycol monopropyl ether, diethylene glycol dimethyl ether, tetrahydrofuran, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, diethylene glycol methyl ether, diethylene glycol ethyl ether, diethylene glycol butyl ether; esters, such as ethylene glycol monomethyl ether acetate, ethylene glycol ether acetate, propylene glycol monomethyl ether acetate, propylene glycol ethyl ether acetate, propylene glycol propyl ether acetate, ethyl 3-ethoxypropionate; and ketones such as ethylmethyl ketone and acetone. Preferably, the solvent (D) is diethylene glycol dimethyl ether, propylene glycol monomethyl ether acetate, ethyl 3-ethoxypropionate or in a combination of two or more so that the photosensitive resin composition has excellent storage stability.
An amount of the solvent (D) can be adjusted depending on requirements. Based on the amount of the alkali-soluble resin (A) as 100 parts by weight, the amount of the solvent (D) is 500 parts by weight to 3000 parts by weight, preferably is 600 parts by weight to 2800 parts by weight, and more preferably is 700 parts by weight to 2500 parts by weight.
Silane Compound (E)
The photosensitive resin composition of the present invention includes a silane compound (E). The silane compound (E) includes a silane compound (E-1) having a structure of formula (I):
in the formula (I), A individually and independently represents a single bond, an alkylene group or an arylene group, B individually and independently represents a hydrogen atom, an alkyl group, an aryl group, —OR or an organic group having a diphenyl phosphine group, in which R is an alkyl group of 1 to 6 carbons or a phenyl group,
in which at least one B is the organic group having the diphenyl phosphine group, at least one B is —OR, and when B is —OR, A connected to B is the single bond.
Specific Examples of the silane compound (E-1) can include [4-dimethyl(1-methylethoxy)silyl]phenyl)diphenyl phosphine, [2-[dimethyl(1-methylethoxy)silyl]phenyl]diphenylphosphine, [2-(methoxydiphenylsilyl)phenyl]diphenyl phosphine, [(ethoxysilylidyne)tris(methylene)]tris[diphenyl phosphine], [(ethoxydimethylsilyl)methylene]bis[diphenyl phosphine], [2-(ethoxydimethylsilyl)ethyl]diphenylphosphine, [3-(dimethylphenoxysilyl)propyl]diphenyl phosphine, [(dimethylphenoxysilyl)methyl]diphenylphosphine, [4-(ethoxydimethylsilyl)phenyl]diphenylphosphine, [2-(dimethylphenoxysilyl)ethyl]diphenylphosphine, [3-(ethoxydimethylsilyl)propyl]diphenylphosphine, [(ethoxydimethylsilyl)methyl]diphenylphosphine, [(dimethoxysilylene)bis(methylene)]bis[diphenyl phosphine], [(diethoxysilylene)di-2,1-ethanediyl]bis[diphenyl phosphine], [4-(diethoxymethylsilyl)phenyl]diphenylphosphine, [(diethoxysilylene)di-3, 1-propanediyl]bis[diphenyl phosphine], [3-(diethoxymethylsilyl)propyl]diphenylphosphine, [(diethoxymethylsilyl)methyl]diphenylphosphine, [2-(diethoxymethylsilyl)ethyl]diphenylphosphine, bis(2-diphenylphosphinoethyl)-methylsilyethyltriethoxysilane, [2-(trimethoxysilyl)ethyl]diphenylphosphine, [2-[6-(trimethoxysilyl)hexyl]-1,3-propanediyl] bis[diphenylphosphine], [6-(trimethoxysilyl)hexyl] diphenylphosphine, [2-[(triethoxysilyl)methyl]-1,3-propanediyl]bis [diphenylphosphine], [1-[2-(triethoxysilyl)ethyl]-1,2-ethanediy]bis [diphenylphosphine], [2-(trimethoxysilyl)ethyl]diphenylphosphine, [6-(triethoxysilyl)hexyl] diphenylphosphine, [4-(triethoxysilyl)butyl] diphenylphosphine, [(triethoxysilyl)methyl] diphenylphosphine, [1-[(triethoxysilyl)methyl]butyl]diphenylphosphine, [1-[(triethoxysilyl)methyl]propyl]diphenyl phosphine, [1-methyl-2-(triethoxysilyl)ethyl]diphenyl phosphine, [7-(triethoxysilyl)heptyl] diphenylphosphine, 1,1′-[(triethoxysilyl)methylene]bis[1,1-diphenyl phosphine], [2-(triethoxysilyl)ethyl] diphenyl phosphine, [4-(triethoxysilyl)phenyl]diphenylphosphine, [2-(triethoxysilyl)propyl] diphenylphosphine, [2-(triethoxysilyl)ethyl]diphenylphosphine or a combination of two or more.
Based on the amount of the alkali-soluble resin (A) as 100 parts by weight, an amount of the silane compound (E-1) is 1 part by weight to 10 parts by weight, preferably is 1.2 parts by weight to 9 parts by weight, and more preferably is 1.5 parts by weight to 8 parts by weight. If the photosensitive resin composition does not include the silane compound (E-1), the film formed by the photosensitive resin composition has poor refractivity and adhesivity to Mo.
Other Silane Compound (E-2)
The photosensitive resin composition of the present invention may further include other silane compound(s) (E-2), and the other silane compound(s) (E-2) may be an adhesion accelerator.
The aforementioned adhesion accelerator can improve adhesivity of the substrate, and preferably the adhesion accelerator is a functional silane crosslinking agent. Preferably, the functional silane crosslinking agent includes a carboxyl group, an alkenyl group, an isocyanate group, an epoxy group, an amine group, a hydrosulphonyl group or halogens. Specific examples of the adhesion accelerator are p-hydroxy phenyl trimethoxy silane, 3-methacryloxypropyl trimethoxysilane, vinyl triacetoxysilane, vinyl trimethoxysilane, vinyl triethoxysilane, vinyl tri(2-methoxyethoxy)silane, γ-isocyanatepropyl triethoxysilane, 3-glycidylpropyl trimethoxysilane, 2-(3,4-epoxycyclohexyl)ethyl trimethoxysilane, 3-glycidylpropryl dimethyl methoxysilane, 3-aminopropyl trimethoxysilane, N-(2-aminoethyl)-3-aminopropyl trimethoxysilane, N-(2-aminoethyl)-3-aminopropylmethyl dimethoxysilane, 3-mercaptpropyl trimethoxysilane, 3-chloropropyl trimethoxysilane and 3-chloropropylmethyl dimethoxysilane. In addition, the adhesion accelerator includes but is not limited to an adhesion auxiliary with a trade name of SZ 6030 (manufactured by Dow Corning Toray Silicone Co., KBE-903, KBE-603, KBE-403 and KBM-403 (manufactured by Shin-Etsu Chemical Co., Ltd.). Depending on requirements of the manufacturing process, the aforementioned adhesion auxiliary can be used alone or in a combination of two or more.
Based on the amount of the alkali-soluble resin (A) as 100 parts by weight, an amount of the other silane compound (E-2) is 0 to 11 parts by weight. Based on the amount of the alkali-soluble resin (A) as 100 parts by weight, an amount of the silane compound (E) is 1 part by weight to 12 parts by weight, preferably is 1.2 parts by weight to 11 parts by weight, and more preferably is 1.5 parts by weight to 10 parts by weight.
Inorganic Particles (F)
The photosensitive resin composition includes inorganic particles (F). The Group IV element oxide is a main component of the inorganic particles (F) according to the invention. By adding the inorganic particles (F) with high refractive rate, the refractivity of the film produced by the photosensitive resin composition is raised.
In one embodiment of the invention, a particle size of the inorganic particles (F) is from 1 nm to 100 nm; preferably is from 1 nm to 50 nm; more preferably is from 5 nm to 15 nm. A method for measuring the particle size may be a known one such as a method by dynamic light scattering. If the particle size is less than 1 nm, secondary aggregation and whiting easily occur in the film obtained thereby; if the particle size is greater than 100 nm, uniformity of a surface of the film may be impacted.
In one embodiment of the invention, the oxide suitable for the inorganic particles (F) is preferably titanium oxide, zirconium oxide, hafnium oxide and composite particles formed by the said metal oxide and silicon oxide as well as tin oxide. More preferably, the inorganic particles (F) is titanium oxide or zirconium oxide, i.e. the group IV element is more preferably titanium or zirconium.
In another aspect, the two crystalline forms, anatase and rutile coexist in titanium oxide. Preferably, the crystalline form is rutile type, which has high refractivity and excellent light resistance.
Furthermore, since titanium oxide has a photocatalytic activity, it is difficult to be applied in an optical field. Preferably, the surface of the particle of titanium oxide is covered by silicon oxide.
According to the present invention, the inorganic particles (F) may be a powder form or a dispersed sol form where the oxide particles are dispersed in a dispersion medium. Examples of the dispersion medium are methanol, methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone, N-methyl-2-pyrrolidone, propylene glycol monomethyl ether, ethoxyethanol.
In one embodiment of the invention, commercially available titanium oxide particles are NanoTek TiO2 made by Japan CI Kasei (the dispersion medium is methyl isobutyl ketone, anatase type); Korea NanoCMS system, Lot No.: S111109 (the dispersion medium is ethoxyethanol, rutile type); Red Lake series made by JGC Shokubai Kasei, Japan (the dispersion medium is methanol, anatase type); TS series made by Tayca (the dispersion medium is methyl ethyl ketone, rutile type). Commercially available zirconium oxide particles are HXU-120JC made by Japan Osaka Cement Co. (the dispersion medium is methyl ethyl ketone) or zirconium oxide particles with the average particle size of 13.00 nm made by Mikuni Color Ltd.
In one embodiment of the invention, based on the amount of the alkali-soluble resin (A) as 100 parts by weight, an amount of the inorganic particles (F) is from 50 to 250 parts by weight, preferably from 60 to 230 parts by weight, more preferably from 70 to 200 parts by weight. If the inorganic particles (F) are used, the refractivity of the photosensitive resin composition can be improved, so as to raise the refractivity of the film obtained thereby.
Additives (G)
Additionally, the photosensitive resin composition of the present invention can further include additives (G) depending on required physical and chemical characteristics, and a selection of the additives (G) can be made by a skilled person in the art. In an example of the present invention, the additive (G) may be a loading agent, polymers except the alkali-soluble resin (A), an ultraviolet light absorber, an anti-agglutinant, a surfactant, a storage stabilizer or a heat-resistance promoter.
Specific examples of the aforementioned loading agent are glass and aluminum. Specific examples of the aforementioned polymers except the alkali-soluble resin (A) are polyvinyl alcohol, polyethylene glycol monoalkyl ether, polyfluoro alkyl acrylate.
Specific examples of the aforementioned ultraviolet light absorber are 2-(3-t-butyl-5-methyl-2-hydroxy phenyl)-5-chlorophenyl azide and alkoxy benzophenone; and the anti-agglutinant is polyacrylate sodium.
The aforementioned surfactant can facilitate a coating ability of the photosensitive resin composition of the present invention. Specific examples of the surfactant may be a fluorine-containing surfactant or a silicone surfactant.
The aforementioned fluorine-containing surfactant at least includes fluorinated alkyl group or a fluorinated alkylene group at an end, a main chain and a branch chain thereof, and specific examples of the fluorine-containing surfactant are 1,1,2,2-tetrafluoro octyl (1,1,2,2-tetrafluoro propyl) ether, 1,1,2,2-tetrafluoro octylhexyl ether, octaethylene glycol di(1,1,2,2-tetrafluorobutyl)ether, hexaethylene glycol (1,1,2,2,3,3-hexafluoropentyl)ether, octapropanediol di(1,1,2,2-tetrafluorobutyl)ether, hexapropanediol (1,1,2,2,3,3-hexafluoropentyl)ether, perfluoro sodium dodecyl sulfate, 1,1,2,2,8,8,9,9,10,10-perfluorododecane, 1,1,2,2,3,3-hexafluorodecane, fluothane benzene sulfonate, fluothane sodium phosphate, fluothane carboxylic sodium, fluothane polyoxyethylene ether, diglycerol tetra(fluothane polyoxyethylene ether), fluothane ammonium iodide, fluothane lycine, fluoroalkyl polyoxyethylene ether, perfluoroalkyl polyoxyethylene ether and perfluoroalkyl alkanol. In another example of the present invention, the fluorine-containing surfactant is BM-1000, BM-1100 (manufactured by BM CHEMIE), Megafac F142D, F172, F173, F183, F178, F191, F471, F476 (manufactured by Dainippon Ink And Chemicals, Inc.), Fluorad FC 170C, FC-171, FC-430, FC-431 (manufactured by Sumitomo Chemical Co., Ltd), chlorofluorocarbons S-112, S-113, S-131, S-141, S-145, S-382, SC-101, SC-102, SC-103, SC-104, SC-105, SC-106 (manufactured by AGC Display Glass Co., Ltd.), F Top EF301, 303, 352 (manufactured by Shin-Akita Kasei), Ftergent FT-100, FT-110, FT-140A, FT-150, FT-250, FT-251, FTX-251, FTX-218, FT-300, FT-310, FT-400S (manufactured by NEOSU).
Specific examples of the aforementioned organic silicone surfactant are TORE organic silicone, with the trade name of DC 3 Paint Additive (DC 3 PA), DC 7 PA, SH 11 PA, SH 21 PA, SH 28 PA, SH 29 PA, SH 30 PA, SH 190, SH 193, SZ 6032, SF-8427, SF-8428, DC 57, DC 190 (manufactured by Dow Corning Toray Silicone), TSF-4440, TSF-4300, TSF-4445, TSF-4446, TSF-4460, TSF-4452 (manufactured by Momentive Performance Materials Inc).
The aforementioned surfactant may also be other surfactants in addition to the aforementioned fluorine-containing surfactant and a silicone surfactant, and the other surfactants may be polyoxyethylene alkyl ether, such as lauryl alcohol polyoxyethylene ether, polyoxyethylene stearate ether and polyoxyethylene oleyl ether; polyoxyethylene aryl ether, such as polyoxyethylene n-octyl phenyl ether and polyoxyethylene n-nonyl phenol ether, polyoxyethylene dialkyl ester, such as polyoxyethylene dilaurate and polyoxyethylene distearate; and nonionic surfactant, such as KP341 (manufactured by Shin-Etsu Chemical Co., Ltd.) and poly flow No. 57, 95 (manufactured by Kyoeisha grease Chemical Industries, Ltd).
The aforementioned surfactant can be used alone or in a combination of two or more.
The aforementioned storage stabilizer may be sulfur, quinones, hydroquinones, polyoxides, amines, nitroso compounds or nitryl group, and specific examples of the storage stabilizer are 4-methoxy phenol, (N-nitroso-N-phenyl) hydroxylamine aluminum, 2,2′-thio-bis(4-methyl-6-t-butylphenol) and 2,6-di-t-butylphenol.
The aforementioned heat-resistance promoter may be N-(alkoxymethyl) glycoluril compound and N-(alkoxymethyl) melamine. Specific examples of the aforementioned N-(alkoxymethyl) glycoluril compound are N,N,N′,N′-tetra(methoxymethyl)glycoluril, N,N,N′,N′-tetra(ethoxymethyl)glycoluril, N,N,N′,N′-tetra(n-propoxymethyl)glycoluril, N,N,N′,N′-tetra(isopropoxymethyl)glycoluril, N,N,N′,N′-tetra(n-butoxymethyl)glycoluril and N,N,N′,N′-tetra(t-butoxymethyl)glycoluril, and preferably is N,N,N′,N′-tetra(methoxymethyl)glycoluril. Specific examples of the aforementioned N-(alkoxymethyl)melamine are as below: N,N,N′,N′,N″,N″-hexa(methoxymethyl)melamine, N,N,N′,N′,N″,N″-hexa(ethoxymethyl)melamine, N,N,N′,N′,N″,N″-hexa(n-propoxymethyl)melamine, N,N,N′,N′,N″,N″-hexa(isopropoxymethyl)melamine, N,N,N′,N′,N″,N″-hexa(n-butoxymethyl)melamine and N,N,N′,N′,N″,N″-hexa(t-butoxymethyl)melamine, and preferably is N,N,N′,N′,N″,N″-hexa(methoxymethyl)melamine. For example, commercial products of the aforementioned N-(alkoxymethyl)melamine are NIKARAKKU N-2702, MW-30M (manufactured by Sanwa Chemical).
An amount of the additives (G) of the present invention can be determined by a skilled person in the art. Preferably, based on the amount of the alkali-soluble resin (A) as 100 parts by weight, the amount of the additives (G) is 0 to 10 parts by weight, preferably is 0 to 6 parts by weight, and more preferably is 0 to 3 parts by weight.
Preparation of Film and Device Having the Same
The present invention provides a film on a substrate. The film is formed by coating the photosensitive resin composition on the substrate, and subjecting the substrate to a pre-bake treatment, an exposing treatment, a developing treatment and a post-bake treatment.
Preferably, the film is a planarized film, an interlayer insulating film of a TFT substrate in a liquid crystal display device or an organic light-emitting device, a core material of a waveguide element or a protective film of a wrapping material.
A coating method of the film of the present invention is subjected to no specific limitation. For example, the photosensitive resin composition is applied onto the substrate by spray-coating, roller-coating, spin-coating, slit-coating, bar-coating, ink-jet printing or the like, preferably by spin-coating or slit-coating. Then, the substrate is subjected to the pre-baking treatment to remove the solvent therein so as to form a prebaked film. The conditions of the pre-baking treatment depend on types and a formulating ratio of the components in the photosensitive resin composition. However, the prebaking treatment is usually conducted at a temperature ranging from 60° C. to 110° C. for 30 seconds to 15 minutes. Preferably, the prebaked film has a thickness ranging from 3 to 6 μm.
After the pre-baking treatment, the prebaked film is subjected to the exposing treatment via a photomask by using, for example, UV light, far-UV light, X ray, charged particle beam. For example, the UV light may be g-line (wavelength of 436 nm), h-line, or i-line (wavelength of 365 nm), the far-UV light may be KrF excimer laser, the X ray may be synchrotron radiation, and the charged particle beam may be an electron beam. Preferably, the UV light is adopted, and more preferably, the g-line or the i-line is adopted. Examples of a device for providing the UV light may include, but are not limited to, a high-pressure mercury lamp, an ultra-high pressure mercury lamp, and a metal halide lamp. Preferably, the exposure dose ranges from 50 to 1500 J/m 2 .
The developing treatment is conducted by immersing the prebaked film into a developing solution for 30 seconds to 2 minutes, so as to remove an undesired portion and obtain a developed film with a desired pattern. Examples of the developing solution include: (1) inorganic alkali compounds, such as sodium hydroxide, potassium hydroxide, sodium carbonate, sodium silicate, sodium metasilicate, and ammonia; (2) primary aliphatic amines, such as ethylamine, and n-propylamine; (3) secondary aliphatic amines, such as diethylamine, and n-propylamine; (4) tertiary aliphatic amines, such as trimethylamine, N,N-diethylmethylamine, N,N-dimethylethylamine, and triethylamine; (5) tertiary alicyclic acids, such as pyrrole, piperidine, N-methyl piperidine, N-methyl-1,8-diazabicyclo[5.4.0]undec-7-ene, and 1,5-diazabicyclo[4.3.0]non-5-ene; (6) tertiary aromatic amines, such as pyridine, methylpyrimidine, dimethylpyridine, and quinoline; and (7) quaternary ammonium alkali compounds, such as an aqueous tetramethylammonium hydroxide solution and an aqueous tetraethylammonium hydroxide solution.
Moreover, water-soluble organic solvents and/or surfactants, such as methanol and ethanol, may be optionally added into the developing solution, and examples of the method of the developing treatment may be but not limited to puddle developing, impregnation developing (with or without sonication), and rinse developing.
The developing solution composed of the alkali components is usually removed by rinsing the developed film on the substrate with water, followed by drying with compressed air or nitrogen gas. Preferably, a post-exposure treatment is conducted using a high-pressure mercury lamp, so as to fully expose the developed film to the radiation. More preferably, the exposure dose of the post-exposure treatment ranges from 2000 to 5000 J/m 2 .
Thereafter, the post-baking treatment is conducted via a heating device, such as a heating plate or an oven, with a temperature ranging from 120° C. to 250° C., so as to cure the film. The baking period of the post-baking treatment may vary depending on a type of the heating device. As for the heating plate, the heating time of the post-baking treatment ranges from 5 minutes to 30 minutes. As for the oven, the heating time ranges from 30 minutes to 90 minutes. The film is obtained by the aforementioned treatments.
Examples of the substrate suitable for the present invention include an alkali-free glass, a soda-lime glass, a Pyrex glass, a quartz glass, a glass coated with a transparent conductive film thereon, and the like, which are commonly used in a liquid crystal display; and a photoelectric conversion substrate (for example, a silicon substrate) used in a solid-state image sensor.
The present invention further provides a device including the aforementioned film.
According to the element of the present invention, the device includes but is not limited to a display device, a semiconductor device, an optical waveguide device or the like.
The following examples are provided to illustrate the preferred embodiments of the invention, and should not be construed as limiting the scope of the invention.
DETAILED DESCRIPTION
Preparation of Alkali-Soluble Resin (A)
Synthesis Example 1
A 500 mL four-necked flask was continuously added with 100 parts by weight of a fluorene epoxy compound (Model ESF-300, manufactured by Nippon Steel Chemical Co., epoxy equivalent 231), 30 parts by weight of acrylic acid, 0.3 parts by weight of benzyltriethylammonium chloride, 0.1 parts by weight of 2,6-di-t-butyl-p-cresol, and 130 parts by weight of propylene glycol methyl ether acetate, wherein the feeding rate was controlled at 25 parts by weight/min, the temperature was maintained in the range of 100° C. to 110° C., and the mixture was reacted for 15 hours to obtain a light yellow and transparent mixture solution having a solid content concentration of 50 wt %.
Next, 100 parts by weight of the mixture solution was dissolved in 25 parts by weight of ethylene glycol ethyl ether acetate, and at the same time, 6 parts by weight of tetrahydrophthalic anhydride and 13 parts by weight of benzophenonetetracarboxylic dianhydride (BTDA) were added. Then, the mixture solution was heated to 110° C. to 115° C. and reacted for 2 hours to obtain the resin (A-1-1) having an unsaturated group, wherein the resin (A-1-1) having an unsaturated group had an acid value of 98.0 mgKOH/g.
Synthesis Example 2
A 500 mL four-necked flask was continuously added with 100 parts by weight of a fluorene epoxy compound (Model ESF-300, manufactured by Nippon Steel Chemical Co., epoxy equivalent 231), 30 parts by weight of acrylic acid, 0.3 parts by weight of benzyltriethylammonium chloride, 0.1 parts by weight of 2,6-di-t-butyl-p-cresol, and 130 parts by weight of propylene glycol methyl ether acetate, wherein the feeding rate was controlled at 25 parts by weight/min, the temperature was maintained in the range of 100° C. to 110° C., and the mixture was reacted for 15 hours to obtain a light yellow and transparent mixture solution having a solid content concentration of 50 wt %.
Next, 100 parts by weight of the mixture solution was dissolved in 25 parts by weight of ethylene glycol ethyl ether acetate, and at the same time, 13 parts by weight of benzophenone tetracarboxylic dianhydride was added, and then the mixture solution was reacted for 2 hours at 90° C. to 95° C. Then, 6 parts by weight of tetrahydrophthalic anhydride was added, and the mixture solution was reacted for 4 hours at 90° C. to 95° C. to obtain the resin (A-1-2) having an unsaturated group, wherein the resin (A-1-2) having an unsaturated group had an acid value of 99.0 mgKOH/g.
Synthesis Example 3
A reaction vessel was added with 400 parts by weight of an epoxy compound (Model NC-3000, manufactured by Nippon Kayaku Co. Ltd.; epoxy equivalent 288), 102 parts by weight of acrylic acid, 0.3 parts by weight of methoxyphenol, 5 parts by weight of triphenyl phosphine, and 264 parts by weight of propylene glycol methyl ether acetate, wherein the temperature was maintained at 95° C., and the mixture was reacted for 9 hours to obtain an intermediate product having an acid value of 2.2 mgKOH/g. Then, 151 parts by weight of tetrahydrophthalic anhydride was added and the mixture was reacted for 4 hours at 95° C. to obtain the resin (A-1-3) having an acid value of 102 mgKOH/g and a weight average molecular weight of 3,200.
Synthesis Example 4
A 1000 ml four-necked flask equipped with a nitrogen inlet, a stirrer, a heater, a condenser and a thermometer was added with nitrogen introduced. 30 parts by weight of methacrylic acid, 35 parts by weight of glycidyl methacrylate, 10 parts by weight of 1,3-butadiene, 25 parts by weight of styrene, 2.4 parts by weight of 2,2′-azobis-2-methylbutyronitrile and 240 parts by weight of diethylene glycol dimethyl ether as the solvent were added. The mixture in the flask was then stirred at a temperature of 85° C. for 5 hours to be polycondensed. Next, the solvent was devolatilized to obtain the alkali-soluble resin (A-2-1).
Synthesis Example 5
A 1000 ml four-necked flask equipped with a nitrogen inlet, a stirrer, a heater, a condenser and a thermometer was added with nitrogen introduced. 10 parts by weight of 2-methacryloyloxyethyl succinate, 50 parts by weight of 3,4-epoxycyclohexylmethyl methacrylate, 20 parts by weight of 2-hydroxyethyl methacrylate, 10 parts by weight of dicyclopentanyl methacrylate, 10 parts by weight of styrene, 2.4 parts by weight of 2,2′-azobis-2-methylbutyronitrile and 240 parts by weight of diethylene glycol dimethyl ether as the solvent were added. The mixture in the flask was then stirred at a temperature of 85° C. for 5 hours to be polycondensed. Next, the solvent was devolatilized to obtain the alkali-soluble resin (A-2-2).
Synthesis Example 6
A 1000 ml four-necked flask equipped with a nitrogen inlet, a stirrer, a heater, a condenser and a thermometer was added with nitrogen introduced. 15 parts by weight of acrylic acid, 30 parts by weight of glycidyl methacrylate, 20 parts by weight of 2-hydroxy ethyl methacrylate, 35 parts by weight of benzyl methacrylate, 2.4 parts by weight of 2,2′-azobis-2-methylbutyronitrile and 240 parts by weight of diethylene glycol dimethyl ether as the solvent were added. The mixture in the flask was then stirred at a temperature of 85° C. for 5 hours to be polycondensed. Next, the solvent was devolatilized to obtain the alkali-soluble resin (A-2-3).
Preparation of Photosensitive Resin Composition
Example 1
100 parts by weight of alkali-soluble resin (A-1-1), 15 parts by weight of p-(isopropylphenyl)phenyl (meth)acrylate (B-1-1), 10 parts by weight of 1-[9-ethyl-6-(2-methylbenzoyl)-9H-carbazol-3-yl]-ethylketone-1-(O-acetyloxime) (C-1), 3 parts by weight of bis(2-diphenylphosphinoethyl)-methylsilyethyltriethoxysilane (E-1-1), and 50 parts by weight of titanium oxide (the average particle size of 13.14 nm; F-1) were added into 500 parts by weight of propylene glycol monomethyl ether acetate (D-1) and stirred by a shaking agitator uniformly, so as to form the photosensitive resin composition of Example 1.
Examples 2 to 11 and Comparative Examples 1 to 3
Examples 2 to 11 and comparative examples 1 to 3 use the same method of forming the photosensitive resin composition as the example 1. However, types and amounts of the components of the examples 2 to 11 and the comparative examples 1 to 3 are changed, and detailed conditions as well as an evaluation result are shown in Table 1.
EVALUATION METHOD
1. Refractivity
The photosensitive resin compositions of the examples and comparative examples were spin-coated on a glass substrate (100 mm×100 mm×0.7 mm) with a thickness of 2 μm. The films were pre-baked at a temperature of 90° C. for 2 minutes. A photoresist mask was placed between an exposure machine and the coated films, and the films were exposed to the UV light with energy of 100 mJ/cm 2 . The exposed films were then immersed in the 0.045% of KOH solution for 50 seconds at 23° C. to remove an unexposed portion. After washed by water, the developed film was pre-baked at 235° C. for 30 minutes to form the desired film.
The refractivity of the film on the glass as mentioned above was assayed by a prism coupler (PC-2010, Metricon Co. Ltd) and a laser with a wavelength of 633 nm at 25° C. in an incubator. Evaluation criteria are as follows.
⊚: refractivity≧1.65;
◯: 1.65>refractivity≧1.60;
Δ: 1.60>refractivity≧1.55; and
X: refractivity<1.55.
2. Adhesivity to Mo
The photosensitive resin compositions of the examples and comparative examples were spin-coated on a Mo plated glass substrate (100 mm×100 mm×0.7 mm) with a thickness of 2 μm. The films were pre-baked at a temperature of 90° C. for 2 minutes. A photoresist mask was placed between an exposure machine and the coated films, and the films were exposed to the UV light with energy of 100 mJ/cm 2 . The exposed films were then immersed in the 0.045% of KOH solution for 50 seconds at 23° C. to remove an unexposed portion. After washed by water, the developed film was pre-baked at 235° C. for 30 minutes to form the desired film. According to a cross-hatched of an adhesiveness testing method in a section 8.5.2 of JIS.K5400(1900) 8.5, the pixel color layer was cut to 100 grid patterns by a knife. Next, the grid patterns were adhered by a tape, and then the tape was removed. An evaluation was made according to the residual grid patterns and the following criterion. The less the damaged grid patterns are, the better the adhesivity to Mo is.
⊚: no damaged grid patterns
◯: 0%<an amount of damaged grid patterns≦5%;
Δ: 5%<the amount of damaged grid patterns≦35%; and
X: 35%<the amount of damaged grid patterns≦100%.
According to the evaluation result in Table 1, the film formed by the photosensitive resin composition including the silane compound (E-1) has good refractivity and adhesivity to Mo. In addition, the film formed by the photosensitive resin composition including the resin having the unsaturated group (A-1), the compound (B-1) and/or the inorganic particles (F) has good refractivity. Moreover, the film formed by the photosensitive resin composition including the compound (B-1) has good adhesivity to Mo. However, the film formed by the photosensitive resin composition without the silane compound (E-1) has poor refractivity and adhesivity to Mo.
Although the present invention has been described in considerable detail with reference to certain embodiments thereof, other embodiments are possible. Therefore, the spirit and scope of the appended claims should not be limited to the description of the embodiments contained herein.
It will be apparent to those skilled in the art that various modifications and variations can be made to the structure of the present invention without departing from the scope or spirit of the invention. In view of the foregoing, it is intended that the present invention cover modifications and variations of this invention provided they fall within the scope of the following claims.
TABLE 1
Comparative
Examples
Examples
composition (parts by
1
2
3
4
5
6
7
8
9
10
11
1
2
3
Alkali-soluble
A-1
A-1-1
100
—
—
70
—
—
—
—
100
—
—
100
—
—
(A)
A-1-2
—
100
—
—
50
—
—
—
—
—
—
—
100
—
A-1-3
—
—
100
—
—
30
—
—
—
—
—
—
—
—
A-2
A-2-1
—
—
—
30
—
—
100
—
—
100
—
—
—
—
A-2-2
—
—
—
—
50
—
—
100
—
—
—
—
—
100
A-2-3
—
—
—
—
—
70
—
—
—
—
100
—
—
—
Compound
B-1
B-1-1
15
—
—
—
—
—
—
—
—
—
—
—
—
—
having vinyl
B-1-2
—
30
—
—
—
—
—
—
—
—
—
—
—
—
group (B)
B-1-3
—
—
50
—
—
—
—
—
—
—
50
—
—
—
B-1-4
—
—
—
100
—
—
—
—
—
—
—
—
—
—
B-2
B-2-1
—
—
50
—
150
—
250
—
150
—
—
100
100
—
B-2-2
—
—
—
—
—
75
—
200
—
300
—
—
—
100
Photoinitiator
C-1
10
—
—
—
—
10
—
90
—
—
30
—
30
—
(C)
C-2
—
15
—
5
50
—
65
—
80
—
—
50
—
—
C-3
—
—
20
25
—
60
—
—
—
100
—
—
—
50
Solvent (D)
D-1
500
—
1100
1400
800
—
2500
—
3000
1000
—
1200
1500
—
D-2
—
700
—
—
1000
2200
—
2800
—
200
2000
—
—
1200
Silane
E-1
E-1-1
3
—
—
—
—
—
8.5
—
—
—
8
—
—
—
compound
E-1-2
—
1
—
—
—
—
—
10
—
—
—
—
—
—
(E)
E-1-3
—
—
5
—
—
—
—
—
—
—
—
—
—
—
E-1-4
—
—
—
1.5
—
—
—
—
—
—
—
—
—
—
E-1-5
—
—
—
—
6.5
—
—
—
0.8
—
—
—
—
—
E-1-6
—
—
—
—
—
2
—
—
—
10.5
—
—
—
—
E-2
E-2-1
—
—
1
—
—
—
—
—
—
—
—
2
—
—
E-2-2
—
—
—
—
—
—
—
2
—
—
—
—
—
2
Inorganic
F-1
50
—
—
—
—
—
—
—
—
—
—
—
—
—
particles (F)
F-2
—
—
135
—
—
—
—
250
—
—
—
—
—
—
F-3
—
—
—
—
—
75
—
—
—
—
—
—
—
—
Additives (G)
G-1
—
1
—
—
—
—
—
—
—
—
—
—
—
—
G-2
—
—
—
—
—
—
2
—
—
—
—
—
—
—
Evaluation
Refractivity
⊚
⊚
⊚
⊚
⊚
⊚
∘
⊚
∘
∘
⊚
X
X
X
Adhesivity to
⊚
⊚
⊚
⊚
∘
∘
∘
∘
Δ
Δ
⊚
X
X
X
Mo
B-1-1 p-(isopropylphenyl)phenyl (meth)acrylate
B-1-2 m-phenylphenyl acylate
B-1-3 o-phenylphenoxy ethyl acrylate
B-1-4 p-phenylphenoxy ethyl acrylate
B-2-1 dipentaerythritol hexacrylate
B-2-2 dipentaerythritol tetracrylate
C-1 1-[9-ethyl-6-(2-methylbenzoyl)-9H-carbazole-3-yl]-ethyl ketone 1-(O-acetaldoxime)
C-2 1-[4-(phenylthio)phenyl]-octane-1,2-diketone 2-(o-benzoyloxime)
C-3 2-methyl-1-[4-(methylthio)phenyl]-2-morpholino-1-propanone
D-1 propylene glycol methyl ether acetate (PGMEA)
D-2 ethyl 3-ethoxylpropionate
E-1-1 bis(2-diphenylphosphinoethyl)-methylsilyethyltriethoxysilane
E-1-2 [2-(triethoxysilyl)ethyl] diphenyl phosphine
E-1-3 [(diethoxysilylene)di-2,1-ethanediyl]bis[diphenyl phosphine]
E-1-4 [4-dimethyl(1-methylethoxy)sily]phenyl)diphenyl phosphine
E-1-5 [3-(dimethylphenoxysilyl)propyl]diphenyl phosphine
E-1-6 [(ethoxysilylidene)tris(methylene)]tris[diphenyl phosphine]
E-2-1 3-methacryloxypropyl trimethoxysilane
E-2-2 3-mercaptpropyl trimethoxysilane
F-1 TiO 2 , average particle size: 13.14 nm (manufactured by NanoCMS, Korea)
F-2 ZrO 2 , average particle size: 17.46 nm (manufactured by Osaka Cement Co., Ltd., Japan)
F-3 ZrO 2 , average particle size: 13.00 nm (manufactured by Mikuni Color Ltd.)
G-1 SF-8427 (manufactured by Dow Corning Toray Silicone)
G-2 KBM-403 (manufactured by Shin-Etsu Chemical Co., Ltd.)
|
A photosensitive resin composition includes an alkali-soluble resin (A), a compound having an unsaturated vinyl group (B), a photo initiator (C), solvent (D) and a silane compound (E) having a structure shown as formula (I):
in the formula (I), A individually and independently represents a single bond, an alkylene group, or an arylene group, B individually and independently represents an organic group having diphenyl phosphine, hydrogen atom, an alkyl group, an aryl group, or —OR, in which R is a C1-C6 alkyl group or a phenyl group, at least one B is the organic group having diphenyl phosphine and at least one B is —OR. When B is —OR, A connected to B is the single bond. A film formed by the photosensitive resin composition has good refractivity and adhesivity to molybdenum.
| 6
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RELATED DISCLOSURE
The subject invention is directed to compounds related to those disclosed and claimed in application Ser. No. 09/284,458 (now U.S. Pat. No. 6,008,215), filed Apr. 16, 1999.
FIELD OF APPLICATION OF THE INVENTION
The invention relates to novel benzonaphthyridines, a process for their preparation, their use and medicaments containing them. The compounds according to the invention are used in the pharmaceutical industry for the preparation of medicaments.
KNOWN TECHNICAL BACKGROUND
WO91/17991 describes under the title “New sulphonyl compounds” certain benzonaphthyridine derivatives, which are to be suitable for the treatment of airway disorders. In WO93/09780 and in DE-OS 4310050 the use of these benzonaphthyridine derivatives for the treatment of dermatoses, allergic rhinitis and conjunctivitis as well as of nasal polyps is described. For the compound (−)-cis-8,9-Dimethoxy-2-methyl-6-[4-(p-toluenesulfonamido)-phenyl]-1,2,3,4,4a,10b-hexahydrobenzo[c][1,6]naphthyridine, which is particularly emphasized in WO91/17991, WO93/09780 and DE 4310050, the WHO has proposed the INN Tolafentrine.
DESCRIPTION OF THE INVENTION
The invention relates to compounds of the formula I
in which
R1 is ethoxy,
R2 is methoxy or ethoxy,
and the salts of these compounds.
The compounds of the formula I are chiral compounds having chiral centers in positions 4a and 10b. The Invention therefore both comprises all conceivable pure diastereomers and pure enantiomers, and their mixtures in any mixing ratio, including the racemates. Preferred compounds of the formula I are those in which the hydrogen atoms in the positions 4a and 10b are cis to one another.
Particularly preferred are the compounds
(−)-cis-8,9-Diethoxy-2-methyl-6-[4-(p-toluenesulfonamido)-phenyl]-1,2,3,4,4a,10b-hexahydro-benzo-[c][1,6]naphthyridine and
(−)-cis-9-Ethoxy-8-methoxy-2-methyl-6-[4-(p-toluenesulfonamido)-phenyl]-1,2,3,4,4a,10b-hexahydro-benzo[c][1,6]naphthyridine
and the salts of these compounds.
Suitable salts for compounds of the formula I preferably are all acid addition salts. Particular mention may be made of the pharmacologically tolerable salts with the inorganic and organic acids customarily used in pharmacy. Examples of such suitable salts are water-soluble and water-insoluble acid addition salts with acids such as for example, hydrochloric acid, hydrobromic acid, phosphoric acid, nitric acid, sulfuric acid, acetic acid, citric acid, D-gluconic acid, benzoic acid, 2-(4-hydroxybenzoyl)benzoic acid, butyric acid, sulfosalicylic acid, maleic acid, lauric acid, malic acid, fumaric acid, succinic acid, oxalic acid, tartaric acid, embonic acid, stearic acid, toluenesulfonic acid, methanesulfonic acid or 3-hydroxy-2-naphthoic acid, where the acids are employed in salt preparation—depending on whether a mono- or polybasic acid is concerned and depending on which salt is desired—in an equimolar quantitative ratio or one differing therefrom.
Pharmacologically intolerable salts, which can be obtained, for example, as process products during the preparation of the compounds according to the invention on an industrial scale, are converted into pharmacologically tolerable salts by processes known to the person skilled in the art.
According to expert's knowledge the compounds of the invention as well as their salts may contain, e.g. when isolated in crystalline form, varying amounts of solvents. Included within the scope of the invention are therefore all solvates and in particular all hydrates of the compounds of formula I as well as all solvates and in particular all hydrates of the salts of the compounds of formula I.
The invention further relates to a process for the preparation of the compounds of the formula I, in which R1 and R2 have the meanings indicated above, and their salts.
The process is characterized in that
a) compounds of the formula II
in which R1 and R2 have the abovementioned meanings, are reacted with a reactive derivative of p-toluenesulfonic acid, or in that
b) compounds of the formula III
in which R1 and R2 have the abovementioned meanings, are subjected to a cyclocondensation reaction
and in that, If desired, compounds of the formula I obtained according to a) or b) are then converted Into their salts, or in that, if desired, salts of the compounds of the formula I obtained according to a) or b) are then converted into the free compounds.
The reaction of compounds of the formula II with reactive derivatives of the p-toluenesulfonic acid (for example, a p-toluenesulfonic acid halide, particularly the acid chloride) is carried out in inert solvents in a manner known to the expert for the preparation of sulfonamides. The reaction is preferably carried out in the presence of an auxiliary base, such as for example, triethylamine or pyridine.
The cyclocondensation is carried out in a manner known per se to the person skilled in the art according to Bischler-Napieralski (e.g. as described in J. Chem. Soc., 1956, 4280-4282) in the presence of a suitable condensing agent, such as, for example, polyphosphoric acid, phosphorus pentachloride, phosphorus trichloride, phosphorus pentoxide, thionyl chloride or preferably phosphorus oxychloride, in a suitable inert solvent, e.g. in a chlorinated hydrocarbon such as chloroform, or in a cyclic hydrocarbon such as toluene or xylene, or another inert solvent such as acetonitrile, or without a further solvent using an excess of condensing agent, preferably at elevated temperature, in particular at the boiling temperature of the solvent or condensing agent used.
The described methods of preparation can be carried out analogously to the methods described in WO91/17991. The following examples serve to illustrate this.
EXAMPLES
1. (−)-cis-8,9-Diethoxy-2-methyl-6-[4-(p-toluenesulfonamido)-phenyl]-1,2,3,4,4a,10b-hexahydro-benzo[c][1,6]naphthyridine
A solution of 2.3 g p-toluenesulfonic acid chloride in 5 ml absolute dichloromethane is added dropwise to a solution of 3.5 g (−)-cis-6-(4-Aminophenyl)-8,9-diethoxy-2-methyl-1,2,3,4,4a,10b-hexahydrobenzo-[c][1,6]naphthyridine in 20 ml absolute pyridine, and the mixture is then stirred at room temperature for a further 3 h. After the evaporation of the solvents, the residue is extracted with dilute sodium hydroxide solution and dichloromethane. The organic phase is then washed with water, dried over sodium sulfate and concentrated. 5.4 g of the title compound are obtained as rough product, which is recrystallised twice in ethyl acetate/methanol. Yield: 4.3 g yellowish crystalls. M.p. 267-268° C.
EF: C 30 H 35 N 3 O 4 S, MW: 533.70
Optical rotation: [α] D 20 =−88.4° (c=1, chloroform/methanol, 1+1) [α] 578 Hg 20 =−93.2° (c=1, chloroform/methanol, 1+1)
2. (−)-cis-9-Ethoxy-8-methoxy-2-methyl-6-[4-(p-toluenesulfonamido)-phenyl]-1,2,3,4,4a,10b-hexahydro-benzo[c][1,6]naphthyridine
2.52 g (−)-cis-3-(3-Ethoxy-4-methoxyphenyl)-1-methyl-4-[4-(p-toluenesulfonamido)-benzamido]-piperidine are heated to boiling under reflux for 5 h in 4.3 ml phosphorus oxychloride and 60 ml of acetonitrile. After destilling off the excess acetonitrile and phosphorus oxychloride, the residue is partitioned between dichloromethane and saturated sodium hydrogencarbonate solution. The organic phase is washed with water, dried over sodium sulfate and concentrated. After evaporation of the dichloromethane, the residue is purified over silica gel by chromatography. The main product fraction is separated and concentrated. The title compound is obtained after recrystallisation in ethyl acetate/diethyl ether (1:10) as faint yellow fine crystalls. M.p. 207-219° C. (unsharp, destruction and red colouring).
EF: C 29 H 33 N 3 O 4 S×0.88H 2 O, MW: 535.49
Optical rotation: [α] D 20 =−65.1° (c=1, methanol)
Starting Compounds
A. (−)-cis-3-(3-Ethoxy-4-methoxyphenyl)-1-methyl-4-[4-(p-toluenesulfonamido)-benzamido]-piperidine
The title compound is obtained by reaction of 1.36 g (−)-cis-4-Amino-3-(3-ethoxy-4-methoxyphenyl)-1-methylpiperidine with 4-(p-toluenesulfonamido)-benzoyl chloride [prepared from 1.5 g 4-(p-toluenesulfonamido)-benzoic acid and thionyl chloride] in dichloromethane under addition of triethylamine as auxiliary base. 2.65 g are obtained as solid foam. M.p. 100-105° C. (the substance sticks together from about 93° C.).
EF: C 29 H 35 N 3 O 5 S, MW: 537.68
Optical rotation: [α] D 20 =−69.6° (c=1, methanol)
B. (−)-cis4-Amino-3-(3-ethoxy4-methoxyphenyl)-1-methylpiperidine dihydrochloride
The title compound is prepared analogously to the method described in DE 4217401, using rac-3-(3-Ethoxy-4-methoxyphenyl)-1-methylpiperid-4-one instead of rac-3-(3,4-Dimethoxyphenyl)-1-methylpiperid-4-one as starting material.
EF: C 15 H 24 N 2 O 2 ×2HCl×0.96H 2 O, MW: 354.52, [colourless crystalls (isopropanol)], m.p. 252-254° C.
Optical rotation: [α] D 20 =−65.5° (c=1, methanol)
C. (−)cis-4-Amino-3-(3-ethoxy-4-methoxyphenyl)-1-methylpiperidine
The free base is prepared from the dihydrochloride (compound B) by treating with dilute sodium hydroxide solution and extraction with dichloromethane. It is used in the next reaction step without further purification.
COMMERCIAL UTILITY
The compounds according to the invention have valuable pharmacological properties which make them commercially utilizable. As potent inhibitors of type 3, 4 and 5 of cyclic nucleotide phosphodiesterase (PDE3, PDE4 and PDE5), they are suitable on the one hand as bronchial therapeutics (for the treatment of airway obstructions on account of their dilating and cilium-stimulating action but also on account of their respiratory rate- and respiratory drive-increasing action), but on the other hand especially for the treatment of disorders of inflammatory nature, e.g. of the airways (asthma prophylaxis), of the skin, of the intestine, of the eyes and of the joints, which are mediated by mediators such as interferons, members of the tumor necrosis factor family, interleukins, chemokines, colony-stimulating factors, growth factors, lipid mediators (e.g., inter alia, PAF, platelet-activating factor), bacterial factors (e.g. LPS), immunoglobulins, oxygen free radicals and related free radicals (e.g. nitrogen monoxide NO), biogenic amines (e.g. histamine, serotonin), kinins (e.g. bradykinin), neurogenic mediators (such as substance P, neurokinin), proteins such as, for example, granular contents of leukocytes (inter alia cationic proteins of eosinophils) and adherent proteins (e.g. integrins). The compounds according to the invention have smooth muscle-relaxant action, e.g. in the region of the bronchial system, of the blood circulation, and of the efferent urinary passages. Furthermore they have a cilium-frequency increasing action, e.g. in the bronchial system.
In this context, the compounds according to the invention are distinguished by low toxicity, good human acceptance, great therapeutic breadth and the absence of significant side effects.
On account of their PDE-inhibiting properties, the compounds according to the invention can be employed as therapeutics in human and veterinary medicine, where they can be used, for example, for the treatment and prophylaxis of the following diseases: acute and chronic (in particular inflammatory and allergen-induced) airway disorders of various origin (bronchitis, allergic bronchitis, bronchial asthma); disorders with a reduction of the cilium activity or with increased demands on the ciliar clearance (bronchitis, mucoviscidose); dermatoses (especially of proliferative, inflammatory and allergic type) such as, for example, psoriasis (vulgaris), toxic and allergic contact eczema, atopic eczema, seborrheic eczema, lichen simplex, sunburn, pruritis in the anogenital area, alopecia areata, hypertrophic scars, discoid lupus erythematosus, follicular and widespread pyodermias, endogenous and exogenous acne, acne rosacea and other proliferative, inflammatory and allergic skin disorders; disorders which are based on excessive release of TNF and leukotrienes, i.e., for example, disorders of the arthritis type (rheumatoid arthritis, rheumatoid spondylitis, osteoarthritis and other arthritic conditions), systemic lupus erythematosus, disorders of the immune system (AIDS), including AIDS-related encephalopathies, autoimmune disorders such as diabetes mellitus (Type I, autoimmune diabetes), multiple sclerosis and of the type virus-, bacteria- or parasite-induced demyelinization diseases, cerebral malaria or Lyme's disease, shock symptoms [septic shock, endotoxin shock, Gram-negative sepsis, toxic shock syndrome and ARDS (adult respiratory distress syndrome)] and also generalized inflammations in the gastrointestinal region (Crohn's disease and ulcerative colitis); disorders which are based on allergic and/or chronic, faulty immunological reactions in the region of the upper airways (pharynx, nose) and of the adjacent regions (paranasal sinuses, eyes), such as, for example, allergic rhinitis/sinusitis, chronic rhinitis/sinusitis, allergic conjunctivitis and also nasal polyps; and also disorders of the central nervous system such as memory disorders and Alzheimer's disease, candidiasis, leishmaniases and leprosy.
On account of their vasorelaxant activity, the compounds according to the invention can also be used for the treatment of high blood pressure disorders of various origin such as, for example, pulmonary high blood pressure and the concomitant symptoms associated therewith, for the treatment of erectile dysfunction or colics of the kidneys and the ureters in connection with kidney stones.
On account of their cAMP-increasing action, however, they can also be used for disorders of the heart which can be treated by PDE inhibitors, such as, for example, cardiac insufficiency, and also as anti-thrombotic, platelet aggregation-inhibiting substances.
The invention further relates to a method for the treatment of mammals including humans who are suffering from one of the abovementioned diseases. The method comprises administering a therapeutically effective and pharmacologically tolerable amount of one or more of the compounds according to the invention to the sick mammal.
The invention further relates to the compounds according to the invention for use in the treatment and/or prophylaxis of diseases, especially the diseases mentioned.
The invention also relates to the use of the compounds according to the invention for the production of medicaments which are employed for the treatment and/or prophylaxis of the diseases mentioned.
The invention furthermore relates to medicaments for the treatment and/or prophylaxis of the diseases mentioned and which contain one or more of the compounds according to the invention.
Advantageously, the substances according to the invention are also suitable for combination with other substances which bring about stimulation of cAMP, such as prostaglandins (PGE2, PGI2 and prostacyclin) and their derivatives, direct adenylate cyclase stimulators such as forskolin and related substances, or substances indirectly stimulating adenylate cyclase, such as catecholamines and adrenergic receptor agonists, in particular beta mimetics. In combination, on account of their cAMP degradation-inhibiting action, they in this case display a synergistic, superadditive activity. This comes to bear, for example, in their use in combination with PGE2 for the treatment of pulmonary hypertension.
The medicaments are prepared by methods known per se familiar to the person skilled in the art. As medicaments, the compounds according to the invention (=active compounds) are either employed as such, or preferably in combination with suitable pharmaceutical auxiliaries, e.g. in the form of tablets, coated tablets, capsules, suppositories, patches, emulsions, suspensions, gels or solutions, the active compound content advantageously being between 0.1 and 95%.
The person skilled in the art is familiar on the basis of his expert knowledge with the auxiliaries which are suitable for the desired pharmaceutical formulations. Beside solvents, gel-forming agents, ointments bases and other active compound excipients, it is possible to use, for example, antioxidants, dispersants, emulsifiers, preservatives, solubilizers or permeation promoters.
For the treatment of disorders of the respiratory tract, the compounds according to the invention are preferably also administered by inhalation. For this purpose, these are administered either directly as a powder (preferably in micronized form) or by atomization of solutions or suspensions which contain them. With respect to the preparations and administration forms, reference is made, for example, to the details in European Patent 163 965.
For the treatment of dermatoses, the compounds according to the Invention are used in particular in the form of those medicaments which are suitable for topical application. For the production of the medicaments, the compounds according to the invention (=active compounds) are preferably mixed with suitable pharmaceutical auxiliaries and additionally processed to give suitable pharmaceutical formulations. Suitable pharmaceutical formulations which may be mentioned are, for example, powders, emulsions, suspensions, sprays, oils, ointments, fatty ointments, creams, pastes, gels or solutions.
The medicaments according to the invention are prepared by methods known per se. The dosage of the active compounds takes place in the order of magnitude customary for PDE inhibitors. Thus topical application forms (such as, for example, ointments) for the treatment of dermatoses contain the active compounds in a concentration of, for example, 0.1-99%. The dose for administration by inhalation is customarily between 0.1 and 3 mg per day. The customary dose in the case of systemic therapy (p.o. or i.v.) is between 0.01 and 10 mg/kg per day.
It is of particular interest for the present invention, that the compounds of formula I according to the invention clearly differ from the structurally closest compound of the state of the art—namely tolafentrine—in a surprising and for the person skilled in the art not foreseeable manner (Data are shown below In the chapter “Biological investigation”).
The in-vitro data presented below for the compounds 1 and 2 (the numbers correspond to the numbers of the examples) show promise that the compounds 1 and 2 will have a clearly improved effectiveness in humans in comparison to tolafentrine. The higher potency with regard to the PDE4-inhibition indicates a considerably stronger antiinflammatory capacity, while the more distinct PDE3/PDE5-inhibition indicates a better broncholytic effectiveness.
BIOLOGICAL INVESTIGATIONS
In the investigation of PDE4 inhibition at the cellular level, the activation of inflammatory cells has particular importance. An example which may be mentioned is the FMLP (N-formylmethionylleucylphenylalanine)-induced superoxide production of neutrophilic granulocytes, which can be measured as luminol-potentiated chemiluminescence [McPhail L C, Strum S L, Leone P A and Sozzani S, The neutrophil respiratory burst mechanism. In “Immunology Serie” 1992, 57, 47-76; ed. Coffey R G (Marcel Decker, Inc., New York-Basel-Hong Kong)].
Substances which inhibit chemiluminescence, and/or cytokine secretion, and/or the secretion of inflammation-increasing mediators in inflammatory cells, like T-lymphocytes, monocytes, macrophages and granulocytes are those which inhibit PDE4 or PDE3 and PDE4. The latter isoenzyme of the phosphodiesterase families is particularly represented in granulocytes. Its inhibition leads to an increase in the intracellular cyclic AMP concentration and thus to the inhibition of cellular activation. PDE4 inhibition by the substances according to the invention is thus a central indicator of the suppression of inflammatory processes. (Giembycz MA, Could isoenzyme-selective phosphodiesterase inhibitors render bronchodilatory therapy redundant in the treatment of bronchial asthma? Biochem Pharmacol 1992, 43, 2041-2051; Torphy T J et al., Phosphodiesterase Inhibitors: new opportunities for treatment of asthma. Thorax 1991, 46, 512-523; Schudt C et al., Zardaverine: a cyclic AMP PDE3/4 inhibitor. In “New Drugs for Asthma Therapy”, 379-402, Birkhaüser Verlag Basel 1991; Schudt C et al., Influence of selective phosphodiesterase inhibitors on human neutrophil functions and levels of cAMP and Ca; Naunyn-Schmiedebergs Arch Pharmacol 1991, 344, 682-690; Tenor H and Schudt C, Analysis of PDE isoenzyme profiles In cells and tissues by pharmacological methods. In “Phosphodiesterase Inhibitors”, 21-40, “The Handbook of Immunopharmacology”, Academic Press, 1996; Hatzelmann A et al., Enzymatic and functional aspects of dual-selective PDE3/4-inhibitors. In “Phosphodiesterase Inhibitors”, 147-160, “The Handbook of Immunopharmacology”, Academic Press, 1996.
A. Methodology
1. Inhibition of the PDE Isoenzymes
The PDE activity was determined according to Thompson et al. (1) with a few modifications (2). The test samples contained 40 mM tris HCl (pH 7.4), 5 mM MgCl 2 , 0.5 μM cAMP or cGMP, [ 3 H] cAMP or [ 3 H]cGMP (about 50,000 cpm/sample), the PDE isoenzyme-specific additives described in greater detail below, the given concentrations of inhibitor and an aliquot of the enzyme solution in a total sample volume of 200 kd. Stock solutions of the compounds to be investigated in DMSO were prepared in concentrations such that the DMSO content in the test samples did not exceed 1% by volume—to avoid affecting the PDE activity. After preincubation at 37° C. for 5 minutes, the reaction was started by addition of the substrate (cAMP or cGMP). The samples were incubated at 37° C. for a further 15 min. The reaction was stopped by addition of 50 μl of 0.2N HCl. After cooling on ice for 10 minutes and addition of 25 μg of 5′-nucleotidase (snake venom from Crotalus atrox), incubation was carried out again for 10 min. at 37° C. and the samples were then applied to QAE Sephadex A-25 columns. The columns were eluted with 2 ml of 30 mM ammonium formate (pH 6.0). The radioactivity of the eluate was measured and corrected by the corresponding blank values. The proportion of hydrolyzed nucleotide in no case exceeded 20% of the original substrate concentration.
PDE1 (Ca 2+ /calmodulin-dependent) from bovine brain: the inhibition of this isoenzyme was investigated in the presence of Ca 2+ (1 mM) and calmodulin (100 nM) using cGMP as a substrate (3).
PDE2 (cGMP-stimulated) from rats' hearts was purified chromatographically [Schudt et al. (4)] and investigated in the presence of cGMP (5 μM) using cAMP as a substrate.
PDE3 (cGMP-inhibited) and PDE5 (cGMP-specific) were investigated in homogenates of human blood platelets [Schudt et al. (4)] using cAMP or cGMP as a substrate.
PDE4 (cAMP-specific) was investigated in the cytosol of human polymorphonuclear leucocytes (PMNL) [isolated from leucocyte concentrates, see Schudt et al. (5)] using cAMP as a substrate. The PDE3 inhibitor motapizone (1 μM) was used in order to suppress the PDE3 activity emanating from contaminating blood platelets.
2. Inhibition of the Formation of Reactive Oxyyen Species in Human PMNL
The formation of reactive oxygen species determined by means of luminol-potentiated chemiluminescence (5) and the isolation of the PMNL from human blood (6) was carried out essentially as described in (5) and (6): equal-size portions (0.5 ml) of the cell suspension (10 7 cells/ml) were preincubated at 37° C. for 5 min. In the absence or presence of the compounds to be investigated in a buffer solution containing 140 mM NaCl, 5 mM KCl, 10 mM HEPES, 1 mM CaCl 2 /MgCl 2 , 1 mg/ml of glucose, 0.05% (w/v) BSA (bovine serum albumin), 10 μM luminol and 4 μM microperoxidase. Stock solutions of the compounds to be investigated in DMSO were prepared in such concentrations that the DMSO content—to avoid an effect on the PDE activity—in the test samples did not exceed 0.1% by volume. After preincubation, the test samples were additionally transferred to the measuring apparatus [“Multi-Biolumnat” LB 9505C from Berthold (Wildbad, Germany)] before stimulation with the receptor agonist FMLP (N-formylmethionylleucylphenylalanine, 100 nM). The chemiluminescence was recorded continuously for 3 min.; the AUC values were calculated from this recording.
3. Statistics
The IC 50 values were determined from the concentration inhibition curves by nonlinear regression using the program GraphPad InPlot™ (GraphPad Software Inc., Philadelphia, USA).
4. References
(1) Thompson W. J., Terasaki W. L., Epstein P. M. and Strada S. J., Assay of cyclic nucleotide phosphodiesterase and resolution of multiple molecular forms of the enzyme; Adv. Cycl. Nucl. Res. 1979, 10, 69-92
(2) Bauer A. C. and Schwabe U., An improved assay of cyclic 3′,5′-nucleotide phosphodiesterase with QAE Sephadex A-25; Naunyn-Schmiedeberg's Arch. Pharmacol. 1980, 311, 193-198
(3) Gietzen K., Sadorf I. and Bader H., A model for the regulation of the calmodulin-dependent enzymes erythrocyte Ca 2+ -transport ATPase and brain phosphodiesterase by activators and inhibitors; Biochem. J. 1982, 207, 541-548.
(4) Schudt C., Winder S., Müller B. and Ukena D., Zardaverine as a selective inhibitor of phosphodiesterase isoenzymes; Biochem. Pharmacol. 1991, 42, 153-162
(5) Schudt C., Winder S., Forderkunz S., Hatzelmann A. and Ullrich V., Influence of selective phosphodiesterase inhibitors on human neutrophil functions and levels of cAMP and Ca; Naunyn-Schmiedeberg's Arch. Pharmacol. 1991, 344, 682-690
(6) Hatzelmann A. and Ullrich V., Regulation of 5-lipoxygenase activity by the glutathione status in human polymorphonuclearleukocytes; Eur. J. Biochem. 1987, 169, 175-184
B. RESULTS
In Table 1 which follows, the Inhibitory concentrations determined according to Section A1 [inhibitory concentrations as −log IC 50 (mol/l)] for the compounds according to the invention are indicated for various PDE isoenzymes. The numbers of the compounds correspond to the numbers of the examples.
TABLE 1
PDE1
PDE2
PDE3
PDE4
PDE5
Tolafentrine
4.75
6.09
7.02
7.20
5.63
1
<5
5.96
7.10
8.60
7.04
2
5.14
6.39
7.28
9.00
6.74
in table 2 below the inhibitory concentrations determined according to Section A2 for tolafentrine and compound 1 are indicated for the FMLP-stimulated chemiluminiscence in human PMNL.
TABLE 2
Inhibition of the FMLP-stimulated chemiluminiscence in human
PMNL in vitro by tolafentnne and compound 1 [inhibitory
concentrations as -log IC 50 (mol/l)].
Tolafentrine
6.07
1
7.39
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Compounds 8,9-diethoxy-2-methyl-6-[4(p-toluenesulfonamide) phenyl]-1,2,3,4,4a,10b-hexahydrobenzo[c][1,6]naphthyridine and 9-ethoxy-8-methoxy-2-methyl-6-[4-(p-toluenesulfonamido)phenyl]-1,2,3,4,4a,10b-hexahydrobenzo[c][1,6]naphthyridine and medicament compositions based thereon are useful for treating airway disorders, high blood pressure disorders and concomitant disorders connected therewith.
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TECHNICAL FIELD
[0001] This disclosure relates generally to a linkage connecting a frame of a machine with an implement.
BACKGROUND
[0002] Earth-moving machines, such as loaders, have linkages connecting the frame of the machine to an implement such as a bucket. Many different linkage designs exist. For many linkage configurations, when raising or lowering the implement, the angle of the implement relative changes. In some cases, when the implement is sufficiently raised from the ground, the angle of the implement relative to the ground may cause material to spill from the back of the implement, towards the machine frame. To prevent this from occurring, it is desirable to tilt the angle of the implement forward as the implement is raised, to maintain an approximately constant angle of the implement relative to the ground.
[0003] Methods of maintaining the angle of an implement relative to the ground are known. One common method is by means of a hydraulic system, such as described in U.S. Pat. No. 3,563,137 to Graber et. al. As a bucket is raised from the ground, a hydraulic cylinder is actuated to tilt the angle of the bucket forward to maintain a constant angle or, at a minimum, prevent the angle of the bucket from exceeding a threshold. Systems of this type, however, often require sensors, valves, specific cylinders, hosing, and software control systems.
[0004] To address these concerns, some linkages may be characterized as “self-leveling.” That is, as the linkage is raised, the mechanical configuration of the linkage causes the angle of the implement relative to the ground to stay substantially level. While these linkages do not have some of the same drawbacks as more complicated leveling systems, the components of a self-leveling linkage may be expensive to produce, requiring specific manufacturing tolerances and complex component shapes. Further, forces imposed on the linkage may cause wear or failure of one or more linkage components. It is therefore desirable to have a mechanical linkage design that is easy to manufacture and also has a design that allows for longer wear life.
[0005] The present disclosure is directed to overcoming or mitigating one or more of the problems set forth above.
SUMMARY
[0006] One aspect of the disclosure provides a linkage for an earth-moving machine. The linkage includes a boom arm pivotably connected to a machine frame at a first pivot, an implement pivotably connected to the boom arm at a second pivot, and an angle control assembly connected to the machine and connected to the implement. The angle control assembly prevents the implement from tilting beyond a threshold when the boom arm is raised. The angle control assembly includes an upper control arm pivotably operably connected to a lower control arm, and a rocker arm pivotally connected to the upper control arm and to the lower control arm.
[0007] In another aspect, an assembly for controlling the angle of an implement on an earth-moving machine is disclosed. The assembly includes an upper control arm, a lower control configured to mechanically interface with the implement, and a rocker arm configured to pivotably couple the lower control arm to the upper control arm.
[0008] In another aspect, an earth-moving machine is disclosed. The machine includes a machine frame, a ground engaging element, a boom arm pivotably connected to a machine frame at a first pivot, a hydraulic cylinder connected to the machine frame and configured to raise or lower the boom arm, and a bucket pivotably connected to the boom arm at a second pivot. The machine also includes an angle control assembly connected to the machine and connected to the bucket. The angle control assembly arm prevents the angle at second pivot from exceeding a threshold when the boom arm is raised. The angle control assembly includes an upper control arm pivotably connected at the first pivot, a lower control arm pivotably connected to the bucket, a rocker arm pivotally connected to the upper control arm and to the lower control arm.
BRIEF DESCRIPTION OF THE DRAWINGS
[0009] FIG. 1 shows an exemplary machine linkage incorporating a system to prevent the angle of an implement from tilting as the linkage is raised.
[0010] FIG. 2 illustrates a block diagram of an implement angle control assembly.
[0011] FIG. 3 illustrates a linkage according to the present disclosure, in several different positions.
DETAILED DESCRIPTION
[0012] FIG. 1 shows an exemplary machine linkage 10 suitable for earth moving machines such as a track loader, wheel loader or backhoe-loader, or a similar machine carrying an implement such as bucket. Machine linkage 10 includes a boom arm 12 operably attached to a frame tower 14 , which is in turn coupled to a machine frame 15 . Boom arm 12 is pivotably connected to machine frame 15 at a pivot 28 . As shown in FIG. 1 , machine linkage 10 may include a plurality of boom arms 12 , and optionally include other structural components, such as a crossbar 16 and a crossbar 18 .
[0013] In the example shown, boom arm 12 is pivotably connected to a bucket 20 at a pivot 42 . Bucket 20 may be raised or lowered relative to the ground by means of one or more boom cylinders 22 . Boom cylinders 22 are coupled to boom arms 12 , and also coupled to frame tower 14 , machine frame 15 , or some other structural component of the machine. Extension of boom cylinders 22 allows bucket 20 to be raised vertically relative to the ground.
[0014] Bucket 20 is also coupled to an implement control cylinder 34 at implement armature 38 . In addition, implement control cylinder is connected at pivot 40 , with implement armature 36 running from pivot 40 to bucket 20 . Extension of implement control cylinder 34 allows bucket 20 to tilt backward or “rack back.” Retraction of the implement control cylinder 34 allows bucket 20 to rotate forward or “dump.”
[0015] In the absence of any other control mechanism, as boom cylinders 22 extend and boom arm 12 is raised, the angle of bucket 20 relative to the ground changes. Potentially, if the linkage is raised to a sufficient height, material might fall out of bucket 20 backward (i.e., towards the frame of the machine). To mitigate this, bucket 20 is pivotably attached to lower control arm 32 at second pivot 21 , to react against bucket 20 as machine linkage 10 is raised, to maintain a substantially constant angle of bucket 20 relative to the ground. Lower control arm 32 is coupled to a rocker arm 30 , which in turn is pivotably connected to boom arm 12 . Rocker arm 30 is pivotably connected to an upper control arm 26 , which preferably but not necessarily attaches to boom arms 12 at first pivot 28 .
[0016] FIG. 2 illustrates a block diagram of an exemplary implement angle control assembly. As will be described in more detail below, angle control assembly 200 prevents an implement from tilting beyond a threshold angle when a linkage is raised by mechanically transmitting motion to a hydraulic valve, which in turns actuates a hydraulic cylinder to control the angle of the implement.
[0017] Angle control assembly 200 includes lower control arm 32 with end 204 for connecting to an implement such as a bucket. Lower control arm 32 also includes end 206 for coupling to rocker arm 30 . Rocker arm 30 is operably coupled to upper control arm 26 , and includes end 210 , where rocker arm 30 may be coupled to the machine (such as to boom arm 12 in FIG. 1 ). These pivotable connections may be made by means of pins or any other mechanisms for fastening well known in the art.
[0018] FIG. 2A shows a closer view of rocker arm 30 . Rocker arm 30 is preferably triangular in shape in one plane, with end 206 of lower control arm 32 preferably attaching near the top of rocker arm 30 , and with end 214 of upper control arm 26 preferably attaching below end 206 on rocker arm 30 . As used herein, the directional terms “above” and “below” refer to height relative to the ground when attached to a machine, and “forward” means in the direction of the implement on the machine, and “backwards” means in the direction away from the implement towards the machine frame. Preferably, rocker arm 30 attaches to the machine at end 210 .
[0019] Angle φ in FIG. 2A is convenient to use as a method of measuring the angular distance between lower mechanism 209 and upper mechanisms 211 , where lower mechanism 209 is formed by points 206 , 210 , 221 and 204 , and the upper mechanism 211 is formed by the points 216 , 214 , 210 and 218 . Lower mechanism 209 and upper mechanism 211 are in essence two four-bar linkages sharing point 210 and separated by angle φ, which can range from a positive angle to a negative angle. The angle φ, as well as the lengths of the lower control arm 32 , upper control arm 26 , rocker arm 30 , the distance from 204 to point 221 , and the distance from 216 to 218 , can be appropriately dimensioned to control the overall action of angle control assembly 200 . The configuration shown allows the movement of lower control arm 32 to be transmitted to upper control arm 26 , through rotation of rocker arm 30 . This movement is not necessarily in a 1 to 1 ratio, and is dependent on the ratio between the lengths 210 to 206 and 218 to 216 . Lower control arm 32 moves in the range of about 1.2 to 2.5 times the distance of movement of upper control arm 26 , as machine linkage 10 is raised, more preferably in the range of about 1.3 to 2.0 times the distance of movement of upper control arm 26 .
[0020] Angle control assembly 200 includes pivot link 216 for rotation about pivot 218 . Angle control assembly 200 also includes a rear assembly 220 . Rear assembly 220 is responsible for transmitting the action of the front mechanism to a valve that controls a hydraulic implement tilt cylinder (e.g., implement control cylinder 34 in FIG. 1 ), thus completing a mechanical feedback loop which controls the angle of bucket 20 , and keeps it from surpassing a certain angle relative to the ground. More specifically in the example of FIG. 2 , rotation of pivot link 216 about pivot 218 rotates lever 222 , which contacts lever 224 and causes rotation of lever 224 about pivot 226 . This in turn, causes movement of linkage arms 232 , 236 , 242 , and 246 , about pivots 226 , 230 , 234 , 238 , 240 , 244 , and 248 . The resulting mechanical motion causes lever 250 to rotate about pivot 248 to actuate a hydraulic valve 252 . Actuation of hydraulic valve 252 causes extension or retraction of a hydraulic cylinder to control the angle of tilt of the implement. Hydraulic valve is preferably a well-known mechanical valve that allows lever 250 to push down or pull up on the valve spool, allowing mechanical motion of lever 250 to be transferred into a change in hydraulic pressure of hydraulic cylinder 34 .
[0021] FIG. 3 shows a linkage consistent with the present disclosure in three different positions. In position A the linkage is not raised and the bucket is the in the dumped position. In positions B and C, however, the linkage is raised at two different heights above the ground, however the angle of the bucket relative to the ground is substantially unchanged. This depicts operation of an angle control assembly such as that described in FIGS. 1 and 2 .
INDUSTRIAL APPLICABILITY
[0022] The present disclosure provides an advantageous linkage system to prevent material from spilling from an implement, such as the bucket on an earth-moving machine. The disclosure provides a mechanical system that avoids the complexities of other types of implement control systems, while providing the necessary control of the angle of a bucket with components that may be easy to manufacture. In addition, due to the arrangement of the components and the nature of forces placed on the components, the components may be relatively more durable over the operating life of the linkage.
[0023] Other embodiments, features, aspects, and principles of the disclosed examples will be apparent to those skilled in the art and may be implemented in various environments and systems.
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An assembly for controlling the angle of an implement on an earth-moving machine. The assembly includes an upper control arm, a lower control configured to mechanically interface with an implement; a rocker arm configured to pivotably couple the lower control arm to the upper control arm.
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BACKGROUND OF THE INVENTION
This invention relates to curing polymeric latexes, more specifically to self-curing polymer latexes.
Diverse self-curing polymer latexes are known in the art. For example, blends of a carboxylated latex such as an acrylic acid/styrene/butadiene terpolymer latex with a melamine formaldehyde or urea formalde resin are known to be self-curing, i.e., they form a curing composition which cures at elevated temperatures.
Other self-curable latex systems employ a carboxylated latex which is crosslinked with a polyvalent cation or with a cationic polymer. Such latexes have the disadvantages of being pH dependent and of forming films which are highly sensitive to water and other aqueous fluids.
It is known that acid and oxazoline groups will react under certain conditions to form an amide ester. Unfortunately, however, latex particles containing both oxazoline and acid groups have not heretofore been prepared.
Accordingly, it would be desirable to provide a polymer latex which is self-curing without the formation of by-products and which, upon curing, forms films or adhesives having excellent physical properties and improved resistance to water and organic solvents.
It would also be desirable to provide a process by which polymers or polymer latexes containing both pendant acid and pendant oxazoline groups are prepared.
SUMMARY OF THE INVENTION
The present invention is such a polymer and process. In one aspect, the present invention is a thermosettable latex composition comprising discrete polymer particles, which particles have been prepared by the polymerization of addition polymerizable monomers, which monomers comprise (a) a coreactive monomer containing pendant groups which are capable of reacting with oxazoline groups to form a covalent bond thereto, (b) an oxazoline as represented by the general structure: ##STR1## wherein R 1 is an acyclic organic radical having addition polymerizable unsaturation, each R 2 is independently hydrogen, halogen or an inertly substituted organic radical and n is 1 or 2 and (c) at least one other addition polymerizable monomer which does not contain a coreactive or oxazoline group.
In another aspect, this invention is a process for preparing a latex comprising discrete particles containing pendant acid and oxazoline groups, said process comprising the steps of (a) forming a latex containing particles of a polymer containing pendant acid groups by polymerizing the first monomer mix comprising an addition polymerizable monomer containing an acidic group and at least one other addition polymerizable monomer which is copolymerizable with said monomer, said polymerization being conducted at a pH sufficiently low that the monomer containing the acidic group substantially copolymerizes with said other monomer, then (b) adjusting the pH of the resulting latex to a value at which an addition polymerizable oxazoline is not significantly reactive or hydrolyzed under conditions suitable for the polymerization thereof, (c) adding to said latex a second monomer mix comprising (1) an addition polymerizable oxazoline as represented by the general structure: ##STR2## wherein R 1 , R 2 and n are as defined hereinbefore and (2) at least one other monomer which does not contain pendant acid or oxazoline groups, and (d) polymerizing said monomer mix under conditions such that the second monomer mix is polymerized within or around said particles of a polymer containin pendant acid groups.
Surprisingly, the latexes of this invention exhibit, upon drying and curing, excellent tensile strength and elongation, as well as superior resistance to water and solvents. Accordingly, such latexes are useful in a variety of applications including films, coatings, adhesives, binders for nonwoven fabrics and the like.
DETAILED DESCRIPTION OF THE INVENTION
The latexes of this invention are advantageously prepared in a two-stage emulsion polymerization process. In the first stage of polymerization, a first monomer mix comprising an addition polymerizable coreactive monomer and at least one other monomer copolymerizable therewith is polymerized.
Such polymerization is conveniently conducted using substantially conventional emulsion polymerization techniques in aqueous medium with conventional additives. Typically, the aqueous phase will contain from about 0.5 to about 5 weight percent (based on the monomer charge) of conventional nonionic or anionic emulsifiers (e.g., potassium, N-dodecyl sulfonate, sodium isooctobenzene sulfonate, sodium laurate, nonyl phenol ethers of polyethylene glycols and the like).
Conventional emulsion polymerization catalysts can be employed in the foregoing latex polymerization and common examples thereof include peroxides, persulfates, azo compounds and the like such as sodium persulfate, potassium persulfate, ammonium persulfate, hydrogen peroxide, azodiisobutyric diamide as well as catalysts (e.g., redox catalysts) which are activated in the water phase (e.g., by a water-soluble reducing agent). The type and amount of catalyst, as well as the particular polymerization conditions employed, will typically depend on the other monomers which are used and polymerization conditions will be generally selected to favor the polymerization of such other monomers. Typically, such catalysts are employed in a catalytic amount, e.g., ranging from 0.01 to about 5 weight percent based upon the monomer weight. In general, the polymerization is conducted at a temperature in the range of from about -10° to about 110° C. (preferably from about 50° to about 90° C.). When the coreactive monomer is one containing pendant weakly acidic groups as described hereinbelow, such as carboxyl groups, the polymerization is advantageously conducted under conditions sufficiently acidic to promote the copolymerization of the weakly acidic coreactive monomers with the other monomers being employed. In such case, the pH is preferably between about 1 and about 6, more preferably between about 1 to about 4. The polymerization may be conducted continuously, semi-continuously or batch-wise.
Similarly, conventional chain transfer agents such as, for example, n-dodecyl mercaptan, bromoform, carbon tetrachloride and the like can also be employed in the normal fashion in the aforementioned first stage polymerization to regulate the molecular weight of the polymer formed therein, and, typically, when such chain transfer agents are used, they are employed in amounts ranging from 0.01 to about 10 (preferably from about 0.1 to about 5) weight percent based upon the weight of the monomers employed in the polymerization. The amount of chain transfer agent employed depends somewhat on the particular transfer agent employed and the particular monomers being polymerized.
Suitable latex polymerization procedures are taught, for instance, in U.S. Pat. Nos. 4,325,856; 4,001,163, 3,513,121; 3,575,913; 3,634,298; 2,399,684; 2,790,735; 2,880,189; and 2,949,386.
The coreactive monomers employed herein are those which contain pendant coreactive groups which are capable of reacting with an oxazoline group to form a covalent bond thereto. It is understood that the reaction of such coreactive groups with the oxazoline group will typically, but not necessarily, cause the oxazoline ring to open.
Typically, the pendant coreactive group on the coreactive monomer will contain a reactive hydrogen atom. Exemplary coreactive groups containing an active hydrogen atom include weak acid groups, aliphatic alcohols; aromatic alcohols, i.e., phenols; amines and amides, i.e., --CONH 2 and --CONH-- groups. In general, the more reactive of such groups, i.e., those having the more labile hydrogen, such as the acids and aromatic alcohols, are preferred herein. Such more reactive groups will generally react with the oxazoline ring more readily under milder conditions than the less reactive groups such as the amines and aliphatic alcohols. Amide groups are generally intermediate in reactivity.
Especially preferred are monomers containing pendant weak acid groups or acid anhydride groups, especially ethylenically unsaturated monomers containing weak acid or acid anhydride groups. Exemplary of suitable monomers containing carboxylic acid groups include itaconic acid, acrylic acid, methacrylic acid, fumaric acid, maleic acid, vinylbenzoic acid and isopropenylbenzoic acid. The more preferred species include acrylic, methacrylic, fumaric, itaconic and maleic acids. Maleic anhydride is an example of a suitable monomer containing an acid anhydride group.
Suitable coreactive monomers containing phenolic groups include ortho- and meta-vinyl phenol.
Suitable coreactive monomers containing aliphatic hydroxyl groups include, for example, hydroxyethylacerylate, hydroxypropylmethacrylate and N-hydroxyethyl-N-methyl acrylamide. Derivatives of styrene having aliphatic hydroxyl groups are also useful herein.
Suitable coreactive monomers containing amide groups include acrylamide, methacrylamide, vinyl acetamide and α-chloroacrylamide. N-methylacrylamides and N-methylmethacrylamide are examples of monomers containing (CONH) groups.
Suitable coreactive monomers containing amine groups include allyl amine, 2-aminoethylacrylate, 3-aminoethylmethacrylate and the like.
In addition to the coreactive monomer, the first monomer mix also contains at least one other monomer which is not a coreactive monomer and which is copolymerizable with the coreactive monomer. A broad range of addition polymerizable monomers are copolymerizable with said coreactive monomers and are suitable herein.
Suitable monomers include, for example, the monovinyl aromatics, alkenes, esters of α,β-ethylenically unsaturated carboxylic acid; carboxylic acid esters wherein the ester group contains addition polymerizable unsaturation; halogenated alkenes; acyclic aliphatic conjugated dienes and the like.
The term "monovinyl aromatic monomer" is intended to include those monomers wherein a radical of the formula: ##STR3## (wherein R is hydrogen or a lower alkyl such as an alkyl having from 1 to 4 carbon atoms) is attached directly to an aromatic nuclear containing from 6 to 10 carbon atoms, including those wherein the aromatic nucleus is substituted with alkyl or halogen substituents. Typical of these monomers are styrene, α-methylstyrene, ortho-, meta- and para-methylstyrene; ortho-, meta- and para-ethylstyrene; o,p-dimethylstyrene; o,p-diethylstyrene; isopropylstyrene; o-methyl-p-isopropylstyrene; p-chlorostyrene; p-bromostyrene; o,p-dichlorostyrene; o,p-dibromostyrene; vinylnaphthalene; diverse vinyl (alkylnaphthalenes) and vinyl (halonaphthalenes) and comonomeric mixtures thereof. Because of considerations such as cost, availability, ease of use, etc., styrene and vinyltoluene are preferred and styrene is especially preferred as the monovinyl aromatic monomer.
Alkenes suitably employed herein include the monounsaturated aliphatic organic compounds such as ethylene, N- and isopropylene, the diverse butenes, pentenes, hexanes and the like as well as alkenes containing diverse substituent groups which are inert to the polymerization thereof. Preferred are unsubstituted C 2 -C 8 alkenes with C 2 -C 4 unsaturated alkenes being most preferred.
Esters of α,β-ethylenically unsaturated carboxylic acids useful herein include typically soft acrylates (i.e., those whose homopolymers have a glass transition temperature (T g ) of less than about 25° C.) such as benzyl acrylate, butyl acrylate, sec-butyl acrylate, cyclohexyl acrylate, dodecyl acrylate, ethyl acrylate, 2-ethylbutyl acrylate, 2-ethylhexyl acrylate, heptyl acrylate, hexyl acrylate, isobutyl acrylate, isopropyl acrylate, methyl acrylate, propyl acrylate, etc.; hard acrylates (i.e., those whose homopolymers have a T g of greater than about 25° C.) such as 4-biphenylyl acrylate and tert-butyl acrylate; soft methacrylates such as butyl methacrylate, and hexyl methacrylate; and hard methacrylates such as sec-butyl methacrylate, tert-butyl methacrylate, cyclohexyl methacrylate, ethyl methacrylate, isobutyl methacrylate, isopropyl methacrylate, methyl methacrylate, propyl methacrylate, etc. The cost, availability and known properties of butyl acrylate and ethyl acrylate make these monomers preferred among the acrylates. The cost, availability and known properties of methyl methacrylate make it preferred among the methacrylates.
Halogenated alkenes useful herein include, for example, vinyl chloride, vinylidene chloride, vinyl fluoride, vinylidene fluoride, the diverse polychloro-, polyfluoro- and polybromo-alkenes and the like.
Acyclic aliphatic conjugated dienes usefully employed herein include typically those compounds which have from about 4 to about 9 carbon atoms, for example, 1,3-butadiene, 2-methyl-1,3-butadiene; 2,3-dimethyl-1,3-butadiene; pentadiene; 2-neopentyl-1,3-butadiene and other hydrocarbon analogs of 2,3-butadienes, such as 2-chloro-1,3-butadiene; 2-cyano-1,3-butadiene, the substituted straight chain conjugated pentadienes, the straight chain and branched chain conjugated hexadienes, other straight and branched chain conjugated dienes having from 4 to about 9 carbon atoms, and comonomeric mixtures thereof. The 1,3-butadiene hydrocarbon monomers such as those mentioned hereinbefore provide interpolymers having particularly desirable properties and are therefore preferred. The cost, ready availability and the excellent properties of interpolymers produced therefrom makes 1,3-butadiene the most preferred acyclic aliphatic conjugated diene.
Mixtures of two or more of the foregoing monomers may, of course, be employed herein, if desired. Of the foregoing monomers, most preferred are styrene, mixtures of styrene and butadiene, butyl acrylate, methyl methacrylate and vinyl acetate.
The proportion of monomers used in the first monomer mix may vary considerably depending upon the particular end-use of the composition. Typically, however, the coreactive monomer is employed in a relatively minor amount, e.g., from about 0.1 to about 20, preferably from about 1 to about 10, weight percent of the monomers. In general, the coreactive monomer is employed primarily to impart the desired self-curing characteristics to latex compositions and the other monomers employed to impart the other desired properties to the composition. For example, in a preferred acid/oxazoline-modified sytrene/butadiene latex, the oxazoline-modified polymer will advantageously exhibit properties similar to those commonly associated with styrene/butadiene polymers and the acid monomer contributes little except curing characteristics to the polymer. It is noted that weak acid-containing polymers also often exhibit enhanced colloidal stability.
Upon completion of the polymerization of the first monomer mix, the pH of the resulting coreactive latex is adjusted, if necessary, into a range which is sufficiently high that during the subsequent polymerization of the second monomer mix containing oxazoline monomers, the oxazoline ring does not significantly react or hydrolyze. Typically, adjustment of the pH into the range from about 3 to about 11, preferably about 6 to about 11, more preferably from about 7 to about 10, is satisfactory. Any convenient water-soluble alkaline material, e.g., ammonium hydroxide, sodiu hydrogen carbonate or sodium hydroxide, is advantageously employed to raise the pH to the aqueous phase.
To the coreactive latex is added a second monomer mix comprising an oxazoline monomer and at least one other addition polymerizable monomer which is not a coreactive monomer or an oxazoline and which is copolymerizable with the oxazoline monomer. This second monomer mix is added to the coreactive latex under conditions such that the monomers are polymerized within or around the coreactive latex particles. The general polymerization conditions employed are as described hereinbefore except that the pH of the aqueous phase is adjusted, if necessary, into the aformentioned range (i.e., sufficient to prevent substantial reaction or hydrolysis of the oxazoline monomer) during the polymerization reaction.
If necessary or desired, additional amounts of aqueous phase emulsifier, catalyst, initiator and the like may be added to the coreactive latex prior to or simultaneously with the addition of the second monomer mix in order to facilitate the polymerization thereof.
The second stage of the polymerization may be conducted immediately following the preparation of the coreactive latex. Alternatively, the coreactive latex may be prepared beforehand and stored until the second stage polymerization is conducted.
The oxazolines employed herein are as represented by the general structure: ##STR4## wherein R 1 is an acyclic organic radical having addition polymerizable unsaturation; each R 1 is independently hydrogen, halogen or an organic radical and n is 3. Preferably, R 1 is ##STR5## wherein R 3 is hydrogen or an alkyl radical. Most preferably, R 1 is an isopropenyl group. Each R 2 is preferably hydrogen or alkyl group with hydrogen being most preferred; n is preferably 1. Most preferably, the oxazoline is 2-isopropenyl-2-oxazoline.
The other monomers employed in this second monomer mix is any addition polymerizable monomer which is not a coreactive monomer or an oxazoline and which is copolymerizable with said oxazoline. In general, those monomers described hereinbefore as useful in the first monomer mix are also usefully employed in the second monomer mix. It is often desirable to "match" the monomers employed in the first monomer mix with those in the second monomer mix, i.e., to employ the same or substantially similar monomers in the same or substantially similar proportions in both the first and second monomer mixes. For example, if styrene, butadiene and acrylic acid are employed in the first monomer mix, a second monomer mix containing styrene, butadiene and oxazoline monomer can be employed to match said first and second monomer mix. Of course, it is not necessary or always desirable to match the backbone of the first and second monomer mixes in the practice of this invention. More generally, the choice of other monomers in both the first and second monomer mixes is such that the resulting latex has the desired physical and chemical properties.
The proportions of monomers used in the second monomer mix may vary considerably depending on the particular end-use of the composition. Typically, however, oxazoline is employed in a relatively minor amount, e.g., from about 0.1 to about 20, and preferably from about 1 to about 10, weight percent of the monomers. In general, the oxazoline monomer is employed primarily to impart the self-curing characteristics to the latex and the other monomers are employed to impart the other desired properties to the latex.
Advantageously, the second monomer mix contains from about 0.05 to about 20, preferably from about 0.2 to about 5, more preferably from about 0.5 to about 2, mole of oxazoline monomer per mole of coreactive monomer employed in the first monomer mix. Most preferably, the amount of oxazoline monomer employed is substantially equivalent on a molar basis to the amount of acid monomer employed.
Following the polymerization of the second monomer mix, there is obtained a curable latex composition. Such composition comprises discrete polymer particles which polymer particles have been prepared by the addition polymerization of monomers comprising (a) a coreactive monomer, (b) an oxazoline monomer as described hereinbefore and (c) at least one other addition polymerizable monomer. When the other monomer in the first monomer mix is different from the other monomers employed in the second monomer mix, the resulting latex particles will have been prepared from, in addition to the oxazoline monomers, at least two other addition polymerizable monomers. While not intending to be bound by theory, it is believed that the polymer particles in the latex of this invention are structured latexes in which the polymers prepared in the second monomer mix either encapsulate or interpenetrate the polymers prepared from the first monomer mix. However, it is recognized that during the polymerization of said second monomer mix, certain amounts of graft or block copolymers may be formed. The precise polymeric structure of the polymer particles is not considered critical to this invention. Essential features of the polymer particles are that such particles contain both pendant coreactive groups and pendant oxazoline groups.
Advantageously, the polymer particles have a particle size distribution such that, upon film formation, the particles can become relatively closely packed together to form coherent films.
The curing latex composition of this invention may be used for a variety of applications including paper coating compositions, adhesives, binders and fibrous, nonwoven fabric compositions and the like. Such compositions are especially suitable for those applications in which a self-curable, curing polymer composition is desired.
The latexes of this invention may be employed as adhesives, films or binders by applying the latex to the desired substrate and then dewatering the latex in curing the dewatered polymers. The dewatering step may be performed by merely allowing the aqueous phase to evaporate under ambient conditions. Alternatively, elevated (i.e., 50°-165° C.) temperatures may be employed to dewater the latex. Curing of the polymer may, likewise, be performed at ambient temperatures. Such ambient temperature curing is an unexpected property of the latexes of this invention. Such room temperature curing is generally conducted over a period of several hours to several days depending on the particular polymers employed, the amounts of oxazoline and coreactive groups in the polymer, the thickness of the film adhesive or binder layers, the amount of crosslinking desired and like factors. Curing may also be effected by heating the polymers to about 100° to about 165° C., preferably 120° to 150° C. for short periods. The foregoing drying and curing points may not be distinct steps but may be carried out simultaneously if desired.
The following examples are intended to illustrate the invention but not to limit the scope thereof. All parts and percentages are by weight unless otherwise indicated.
EXAMPLE 1
Into a 1-gallon, jacketed reactor equipped with lab pumps to deliver monomer and aqueous feeds are added 593 g of deionized water, 7 g of a 1 percent active aqueous pentasodium diethylene triamine pentacetate solution and 21.9 g of a 32 percent solids seed latex containing polystyrene particles having a volume average particle size of about 263 Å.
The reactor is purged with nitrogen and heated to 90° C. Then, over a 3-hour period, is added a monomer stream containing 455 g of butyl acrylate, 217 g of styrene, 28 g of acrylic acid and 3.8 g of 55 percent active divinylbenzene. Beginning simultaneously with the start of the monomer stream is added continuously over a 4-hour period 245 g of deionized water, 15.56 g of a 45 percent active aqueous surfactant solution, 14 g of a 10 percent aqueous sodium hydroxide solution and 4.9 g of sodium persulfate. Following addition of the monomer and aqueous streams, the reaction mixture is heated at 90° C. for 1 additional hour and then cooled. The product is a 45 percent solids latex of a butyl acrylate/styrene/acrylic acid/divinylbenzene polymer in a 65:31:4:0.3 percent weight ratio.
A 1244.0 g portion of the resulting coreactive latex is then placed into a 1-gallon stainless steel reactor together with 100 g of water and sufficient ammonium hydroxide to increase the pH from 3.9 to 8.7. The reactor is then purged with nitrogen and the monomer mix comprising 14 g of 2-isopropenyl-2-oxazoline, 91 g of butyl acrylate and 35 g of styrene are added. Also added are 171 g of deionized water and 0.7 g of sodium persulfate. The resulting mixture is then polymerized at 60° C. for 8 hours and cooled. The resultant latex contains polymer particles having both pendant acid and pendant oxazoline groups, as confirmed by infrared spectroscopy.
The resultant latex is thickened with a small amount of sodium polyacrylate and 20-mil thick films of the latex are cast onto a Teflon brand coated steel plate using a film bar of 20-mil thickness. The films are then dried at ambient temperature until they are transparent and then they are peeled from the plate and further dried at ambient temperature for about 24 hours. The air-dried films are then cured for 5 minutes in an oven set at diverse curing temperatures as noted in Table I following. The cured films are then cut into 0.5-inch wide strips and tested on an Instron tensile tester to measure elongation and tensile strength at break. Duplicate cured films are soaked in an excess of 0.5 percent aerosol OT solution for 5 minutes and then tested on an Instron to measure elongation and tensile strength at break. For comparison, a sample of the carboxylic latex containing no pendant oxazoline group is formed into films and tested as described herein. The results are as reported as Sample No. C-1 in Table I following. The results obtained on films prepared from the latex of this invention are reported in Table I following as Sample No. 1.
TABLE I______________________________________ Comparative Sample No. 1 Sample No. C-1*______________________________________R.T. Cure .sup.1Dry Tensile.sup.2 815 1085Wet Tensile.sup.3 909 383Dry Elong..sup.4 351 413Wet Elong..sup.5 285 435100° C. Cure.sup.6Dry Tensile 1385 965Wet Tensile 1124 472Dry Elong. 304 395Wet Elong. 275 443120° C. Cure.sup.7Dry Tensile 1361 851Wet Tensile 1300 378Dry Elong. 268 399Wet Elong. 283 401150° C. Cure.sup.8Dry Tensile 1460 861Wet Tensile 1648 562Dry Elong. 236 403Wet Elong. 260 504______________________________________ *Not an example of the invention. .sup.1 Films cured at room temperature for 24 .sup.2 Tensile strength of films cured at designated temperatures measure in dry films using an Instron tensile .sup.3 Tensile strength of films cured at the designated temperatures, measured on films soaked for 5 minutes in a 0.5 percent aqueous surfactan solution immediately before testing. Testing performed on an Instron tensile tester. .sup.4 Percent elongation of films cured at designated temperatures measured on dry films using an Instron tensile .sup.5 Percent elongation of films cured at the designated temperature, measured on films soaked in an aqueous surfactant solution immediately before testing. Testing performed on an Instron Tensile .sup.6 Films cured at 100° C. for 5 .sup.7 Films cured at 120° C. for 5 .sup.8 Films cured at 150° C. for 5 minutes.
As can be seen from Table I above, the latex of this invention forms films having higher tensile strength than the films formed from the control latex. More significantly, the tensile strength of the films of this invention are not significantly impaired upon soaking the films in water. In fact, at high curing temperatures, wetting of the films actually increases their tensile strength. By contrast, the control samples loses significant tensile strength upon soaking in the surfactant solution.
EXAMPLE 2
In this example, a coreactive latex (51 percent solids) containing a styrene/butadiene/fumaric acid terpolymer (57.6/40.5/1.9 weight ratio) is used as a starting material.
A 1584-g portion of this latex is added to a 1-gallon stainless steel reactor. Sufficient of the 28 percent aqueous ammonium hydroxide solution is added to the latex to increase the pH to about 8.5. Then, 198 g of deionized water, 2 g of a 1 percent active sodium diethylene triamine pentaacetate solution, 1 g of sodium persulfate, 20 g of 2-isopropenyl-2-oxazoline, 99 g of styrene and 4 g of carbon tetrachloride are added. The reactor is then purged with nitrogen and 81 g of butadiene are added. The reaction mixture is then heated to 60° C. for 8 hours. The latex is then steam distilled to remove unreacted monomers. The resulting latex contains particles having both pendant coreactive and pendant oxazoline groups, as confirmed by infrared spectroscopy. Films are prepared from the product latex and cured as described in Example 1 hereinbefore. The tensile properties of the resultant films are evaluated as described in Example 1 with the results as reported as Sample No. 2 in Table II following.
For comparison, a portion of the coreactive latex which has not been modified with the oxazoline polymer is formed into films, cured and tested as described in Example 1. The results are as reported in Sample No. C-2 in Table II following.
TABLE II______________________________________ Comparative Sample No. 2 Sample No. C-2*______________________________________R.T. Cure.sup.1Dry Tensile.sup.2 997 1052Wet Tensile.sup.3 406 103Dry Elong..sup.4 443 552Wet Elong..sup.5 351 207100° C. Cure.sup.6Dry Tensile 1072 1173Wet Tensile 458 110Dry Elong. 447 531Wet Elong. 362 286120° C. Cure.sup.7Dry Tensile 1268 1215Wet Tensile 624 123Dry Elong. 455 546Wet Elong. 387 361150° C. Cure.sup.8Dry Tensile 1420 1500Wet Tensile 1195 392Dry Elong. 435 579Wet Elong. 405 405______________________________________ *Not an example of the invention. Notes .sup.1 through .sup.8 are the same as in Table I.
Here, it is seen that the dry tensile strength of the carboxylated, IPO modified latex is essentially equivalent to those of the dry carboxylated latex. However, when wet tensile strength is evaluated, the film prepared from latexes of this invention are clearly superior to those of the control.
EXAMPLE 3
In this example, a 48.6 percent solids latex of a 58/38/4 ratio of styrene/butadiene/acrylic acid terpolymer is employed as coreactive starting material.
A 1646-g portion of this latex is added to a 1-gallon stainless steel reactor. Sufficient of a 28 percent aqueous ammonium hydroxide solution is added to the latex to increase the pH to about 8.6. Then, 198 g of deionized water, 1 g of sodium persulfate, 2.0 g of a 1 percent active sodium diethylene tetraamine pentaacetate solution, 20 g of 2-isopropenyl-2-oxazoline, 96 g of styrene and 6 g of carbon tetrachloride are added to the reactor. The reactor is then purged with nitrogen and 84 g of butadiene are added. The resulting mixture is then polymerized at 60° C. for 7 hours. The resultant latex contains particles having both pendant acid and pendant oxazoline groups. Films are formed from the product latex according to the method described in Example 1 and are tested for tensile properties. The results are as reported in Table III. For comparison, films are prepared from the carboxylated latex containing no oxazoline groups. These films are tested for tensile properties with the results as reported in Table III following as Sample No. C-3.
TABLE III______________________________________ Comparative Sample No. 3 Sample No. C-3*______________________________________R.T. Cure.sup.1Dry Tensile.sup.2 1642 1709Wet Tensile.sup.3 963 1412Dry Elong..sup.4 411 370Wet Elong..sup.5 315 276100° C. Cure.sup.6Dry Tensile 1819 1849Wet Tensile 1510 1412Dry Elong. 406 395Wet Elong. 347 276120° C. Cure.sup.7Dry Tensile 1989 1750Wet Tensile 1598 1776Dry Elong. 403 378Wet Elong. 348 342150° C. Cure.sup.8Dry Tensile 1949 1744Wet Tensile 2008 1805Dry Elong. 355 377Wet Elong. 324 331______________________________________ *Not an example of the invention. Notes .sup.1 through .sup.8 are the same as in Table I.
Again, the excellent tensile properties of wet and dry films of this invention are seen.
EXAMPLE 4
Into a 1-liter, glass reactor immersed in a temperature controlled water bath are added 359 g of deionized water, 3 g of a 1 percent active aqueous pentasodium diethylene triamine pentaacetate solution and 4.5 g of a 32 percent solids seed latex containing polystyrene polymer particles.
The reactor is purged with nitrogen and heated to 83° C. Then, over a 1-hour period is added a first monomer stream containing 90 g of butylacrylate, 53.75 g of methylmethyacrylate and 5.0 g of acrylic acid. After this first monomer addition, the reactor is maintained at about 83° C. for 15 minutes. Three grams of 28 percent ammonium hydroxide solution is added to increase the pH from 3.5 to 8.3, and then a second monomer stream is begun. This second monomer stream is added over a 1-hour period and contains 90 g of butylacrylate, 53.75 g methylmethacrylate and 7.5 g of 2-isopropenyl-2-oxazoline. Beginning at the start of the first monomer addition is also added, over a 21/4-hour period, an aqueous stream containing 90 g deionized water, 1.5 g of sodium persulfite, 0.3 g NaOH and 3.3 g of a 45 percent active surfactant solution. Following the addition of the monomer and aqueous streams, the reactor is maintained at 83° C. for 1 additional hour, and then cooled.
This latex is formed into films as described in Example 1. The films are cured by heating at 125° C. for 5 minutes and tested for tensile strength and elongation as described in Example 1. The results are reported as Sample No. 4 in Table IV following.
For comparison, films are prepared in like manner from the following latexes:
______________________________________Sample No. C-4A Butylacrylate/methylmethacrylate (60/40)Sample No. C-4B Butylacrylate/methylmethacrylate/ acrylic acid (60/38.33/1.67)Sample No. C-4C Butylacrylate/methylmethacrylate/ 2-isopropenyl-2-oxazoline (60/37.5/2.5)Sample No. C-4D 50:50 Blend of C-4B and C-4C______________________________________
All films are tested for tensile strength and elongation as described hereinbefore with the results as reported in Table IV following.
TABLE IV______________________________________ Sample No. 4 C-4A* C-4B* C-4C* C-4D*______________________________________Dry Tensile.sup.1 1420 710 960 980 1080Dry Elongation.sup.2 560 730 680 780 690Wet Tensile.sup.3 940 380 740 860 906Wet Elongation.sup.4 430 550 630 600 630______________________________________ *Not an example of the invention. .sup.1 Same as Note.sup.2, Table I. .sup.2 Same as Note.sup.4, Table I. .sup.3 Same as Note.sup.3, Table I. .sup.4 Same as Note.sup.5, Table I.
As can be seen from the data in Table IV, films prepared from the latex of this invention exhibit the highest tensile stength, whether tested wet or dry. Even Sample No. C-4D, which contains only oxazoline-containing particles and acid-containing particles, does not exhibit the tensile strength of films prepared from the latex of this invention.
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Latexes containing particles having pendant coreactive groups and oxazoline groups are disclosed. Said latexes are self-curing yielding films and other articles having excellent tensile strength and resistance to water and other solvents. In addition, a process for making such latexes is disclosed.
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BACKGROUND OF THE INVENTION
[0001] In the manufacture of paper products, such as facial tissue, bath tissue, paper towels, dinner napkins and the like, a wide variety of product properties are imparted to the final product through the use of chemical additives applied in the wet end of the tissue making process. Two of the most important attributes imparted to tissue through the use of wet end chemical additives are strength and softness. Specifically for softness, a chemical debonding agent is normally used. Such debonding agents are typically quaternary ammonium compounds containing long chain alkyl groups. The cationic quaternary ammonium entity allows for the material to be retained on the cellulose via ionic bonding to anionic groups on the cellulose fibers. The long chain alkyl groups provide softness to the tissue sheet by disrupting fiber-to-fiber hydrogen bonds in the sheet.
[0002] Such disruption of fiber-to-fiber bonds provides a two-fold purpose in increasing the softness of the tissue sheet. First, the reduction in hydrogen bonding produces a reduction in tensile strength thereby reducing the stiffness of the tissue sheet. Secondly, the debonded fibers provide a surface nap to the tissue sheet enhancing the “fuzziness” of the tissue sheet. This tissue sheet fuzziness may also be created through use of creping as well, where sufficient interfiber bonds are broken at the outer tissue surface to provide a plethora of free fiber ends on the tissue surface.
[0003] Both debonding and creping increase levels of lint and slough in the product. Indeed, while softness increases, it is at the expense of an increase in lint and slough in the tissue sheet relative to an untreated control. It can also be shown that in a blended (non-layered) tissue sheet that the level of lint and slough is inversely proportional to the tensile strength of the tissue sheet. Lint and slough can generally be defined as the tendency of the fibers in the paper sheet to be rubbed from the sheet when handled.
[0004] A multi-layered tissue structure to enhance the softness of the tissue sheet. One such embodiment, a thin layer of strong softwood fibers is used in the center layer to provide the necessary tensile strength for the product. The outer layers of such structures are composed of the shorter hardwood fibers, which may or may not contain a chemical debonder. A disadvantage to using layered structures is that while softness is increased the mechanism for such increase is believed due to an increase in the surface nap of the debonded, shorter fibers. As a consequence, such structures, while showing enhanced softness, do so with a trade-off of an increase in the level of lint and slough.
[0005] A chemical strength agent may be added in the wet-end to counteract the negative effects of the debonding agents. In a blended tissue sheet, the addition of such chemical strength agents reduces lint and slough levels. However, such reduction is done at the expense of surface feel and overall softness of the tissue sheet and becomes primarily a function of tissue sheet tensile strength. In a layered tissue sheet, strength chemicals are added preferentially to the center layer. While this perhaps helps to give a tissue sheet with an improved surface feel at a given tensile strength, such structures actually exhibit higher slough and lint at a given tensile strength, with the level of debonder in the outer layer being directly proportional to the increase in lint and slough. Co-pending U.S. patent application Ser. No. 09/736,924 (Shannon et al.) published on Aug. 22, 2002 discloses low slough tissue products made with acrylamides containing hydrophobic moieties. These synthetic polymers, while reducing the amount of slough compared to traditional debonders, still show an increase in slough with decreasing tensile strength.
[0006] Therefore there is a need for a means of reducing lint and slough in soft tissue sheets while maintaining the softness and strength of the tissue sheets. It is an objective of the present invention to design paper-making chemicals, more specifically tissue making chemicals, capable of reducing hydrogen bonding while also possessing ability to reduce lint and slough. It is a further objective to develop a process for making soft, low slough, low lint tissue products via wet end application of chemistry. It is a further objective of the present invention to make soft, absorbent, low lint and slough tissue products such as sanitary bath tissue, facial tissue, paper towels and the like via wet end application of such chemistry.
SUMMARY
[0007] It has now been discovered that certain cationic water dispersible synthetic copolymers when applied to the wet end of the tissue machine may act as debonding chemicals while at the same time reducing the amount of lint and slough. Hence, soft tissue sheets having low lint and slough levels are obtained. The chemicals of the present invention are synthetic co-polymers formed from two or more different monomers. The synthetic co-polymers of the present invention are the polymerization product of a cationic monomer and at least one hydrophobic monomer. Additionally, the synthetic co-polymers of the present invention may also be the polymerization product of a cationic monomer, at least one hydrophobic monomer and optionally at least one non-ionic hydrophilic monomer. While not wishing to be bound by theory, it is believed that the synthetic copolymers attach to the fibers via electrostatic attraction for the anionic fibers. As the synthetic co-polymers have no hydrogen or covalent bonding entity, they debond the fibers via the traditional mechanism by which chemical debonding agents function.
[0008] The synthetic co-polymers of the present invention are, however, good film forming agents and have good inter-molecular adhesive properties. Hence, the fibers are held in place by the co-polymer to co-polymer cohesive properties and good slough reduction occurs. The aliphatic hydrocarbon portion of the synthetic co-polymer molecule enables a significant level of debonding to occur and insures that the tissue sheet product has good surface nap or “fuzzy” feel. Yet, these fibers retain a significant inter-fiber bonding potential due to intra- and inter-molecular associative forces present in the synthetic copolymers that help the fibers remain anchored to the tissue sheet. As such, fibers treated with these synthetic co-polymers produce a tissue sheet having lower lint and slough at a given tensile strength than a tissue sheet prepared with conventional softening agents or a combination of conventional softening agents and conventional strength agents.
[0009] The term “water dispersible” as used herein, means that the cationic synthetic copolymers are either water soluble or capable of existing as stable colloidal, self-emulsifiable or other type dispersions in water without the presence of added emulsifiers. Added emulsifiers may be employed within the scope of the present invention to aid in the polymerization of the cationic synthetic co-polymers or assist in compatiblizing the cationic synthetic co-polymers with other chemical agents used in the tissue sheet, however, the emulsifiers are not essential to formation of stable dispersions or solutions of the cationic synthetic co-polymers in water.
[0010] It is known in the art to add latex polymer emulsions of styrene butadiene rubber binders and ethylene vinyl acetate binders topically to a formed tissue sheet to decrease strength loss associated with topical application of debonders and other softening agents. Large amounts of emulsifiers are used in the production of such latex polymers and these emulsifiers are critical to the stability of the latex polymers in water. The latex polymers are not of themselves water dispersible. The emulsions are susceptible to breaking, causing a film of the latex polymer to develop on processing equipment. This film continues to deposit on equipment to the point where shutdown and clean-up of the equipment is required. As the latex polymers are not water dispersible clean-up can be time consuming, costly and environmentally unfriendly. Furthermore, the lack of water dispersability makes tissue sheets made with these latex polymers difficult to impossible to redisperse, causing a significant economic penalty to be incurred in tissue sheets employing these traditional latex polymers. As these latex polymers are not cationic, wet end application of these latex polymers is significantly constrained and the latex polymers demonstrate ability to only increase strength. The disadvantages to using these materials have severely limited commercial use of traditional latex polymers in tissue-based products.
[0011] It is known wherein a procedure for creping paper comprises incorporation in paper pulp or a paper sheet of a cationic water soluble addition polymer containing amine groups and optionally quaternary ammonium groups. Optionally the addition polymer may contain units of one other monoethylenically unsaturated monomers in a level such that the addition polymer remains water soluble. A critical aspect of such a procedure is the presence of free amine groups which, when used in conjunction with the optional quaternary group, must be present in a ratio>1:1 relative to the quaternary group. The addition polymers are used as creping facilitators to promote enhanced Yankee dryer adhesion. However, enhanced Yankee dryer adhesion is typically not a desirable characteristic when making low slough and lint tissue-based products, such adhesion being known to those skilled in the art to increase levels of lint and slough. Furthermore, the presence of the free amine groups makes the addition polymers sensitive to pH when applied in the wet end of tissue making processes, turning the tissue sheet hydrophobic under acidic conditions and imparting undesired wet strength when used under basic conditions. An additional consideration when using the addition polymers is the presence of the free amine groups, capable of reacting with other papermaking additives, such as those containing aldehyde and azetidinium groups, thereby risking the reduction of the efficacy of those additives.
[0012] Hence, in one aspect, the present invention resides in a tissue chemical additive capable of simultaneously debonding and reducing lint and slough, the tissue chemical additive comprising a cationic synthetic water dispersible co-polymer containing a hydrophobic portion such that the hydrophobic portion is capable of demonstrating intra-molecular adhesive properties in the dry state while exhibiting ability to debond a tissue sheet when applied to the tissue sheet at a low consistency. The synthetic co-polymers have the following general structure:
[0013] Wherein:
[0014] R 1 , R 2 , R 3 are independently H, C 1-4 alkyl radical, or mixtures thereof.
[0015] R 4 is a C 1 -C 8 alkyl radical or mixtures thereof.
[0016] Z 1 is a bridging radical attaching the R 4 functionality to the polymer backbone. Examples include, but are not limited to, —O—, —COO—, —OOC—, —CONH—, —NHCO—, and mixtures thereof.
[0017] Q 1 is a functional group containing a cationic quaternary ammonium radical.
[0018] Q 2 is an optional group comprised of a non-ionic hydrophilic or water soluble monomer or monomers (and mixtures thereof) incorporated into the synthetic co-polymer so as to make the synthetic co-polymer more hydrophilic. Q 2 possesses limited ability to hydrogen or covalently bond to cellulose fibers, such bonding resulting in an increase in stiffness of the tissue sheet. Suitable hydrophilic monomers or water-soluble nonionic monomers for use in the cationic synthetic co-polymers of the present invention include, but are not limited to, monomers, such as, hydroxyalkyl acrylates and hydroxyalkyl methacrylates, such as hydroxyethyl methacrylate (HEMA); hydroxyethyl acrylate; polyalkoxyl acrylates, such as polyethyleneglycol acrylates; and, polyalkoxyl methacrylates, such as polyethyleneglycol methacrylates (“PEG-MA”). Other suitable hydrophilic monomers or water-soluble nonionic monomers for use in the ion-sensitive cationic synthetic copolymers of the present invention include, but are not limited to, diacetone acrylamide, N-vinylpyrrolidinone, and N-vinylformamide.
[0019] The mole ratio of z:x will specifically range from about 0:1 to about 4: 1, more specifically from about 0:1 to about 1:1, and most specifically from about 0:1 to about 1:3. The mole ratio of (x+z):y may be from about 0.98:0.02 to about 1:1, and most specifically from about 0.95:0.05 to about 0.70:0.30.
[0020] Hence, in another aspect, the present invention resides in a soft, low lint and slough absorbent paper sheet, such as a tissue sheet, comprising a cationic synthetic water dispersible co-polymer containing a hydrophobic portion such that the hydrophobic portion is capable of demonstrating intermolecular associative properties in the dry state while exhibiting ability to debond a tissue sheet when applied to the tissue sheet at a low consistency. The cationic water dispersible synthetic co-polymers have the following general structure:
[0021] Wherein:
[0022] R 1 , R 2 , R 3 are independently H, C 1-4 alkyl radical, or mixtures thereof.
[0023] R 4 is a C 1 -C 8 alkyl radical or mixtures thereof.
[0024] Z 1 is a bridging radical attaching the R 4 functionality to the polymer backbone. Examples include, but are not limited to, —O—, —COO—, —OOC—, —CONH—, —NHCO—, and mixtures thereof.
[0025] Q 1 is a functional group containing a cationic quaternary ammonium radical.
[0026] Q 2 is an optional group comprised of a non-ionic hydrophilic or water soluble monomer or monomers (and mixtures thereof) incorporated into the synthetic co-polymer so as to make the synthetic co-polymer more hydrophilic. Q 2 possesses limited ability to hydrogen or covalently bond to cellulose fibers, such bonding resulting in an increase in stiffness of the tissue sheet. Suitable hydrophilic monomers or water-soluble nonionic monomers for use in the cationic synthetic co-polymers of the present invention include, but are not limited to, monomers, such as, hydroxyalkyl acrylates and hydroxyalkyl methacrylates, such as hydroxyethyl methacrylate (HEMA); hydroxyethyl acrylate; polyalkoxyl acrylates, such as polyethyleneglycol acrylates; and, polyalkoxyl methacrylates, such as polyethyleneglycol methacrylates (“PEG-MA”). Other suitable hydrophilic monomers or water-soluble nonionic monomers for use in the ion-sensitive cationic synthetic copolymers of the present invention include, but are not limited to, diacetone acrylamide, N-vinylpyrrolidinone, and N-vinylformamide.
[0027] The mole ratio of z:x will specifically range from about 0:1 to about 4:1, more specifically from about 0:1 to about 1:1, and most specifically from about 0:1 to about 1:3. The mole ratio of (x+z):y may be from about 0.98:0.02 to about 1:1, and most specifically from about 0.95:0.05 to about 0.70:0.30.
[0028] In another aspect, the present invention resides in a method of making a soft, low lint tissue sheet, comprising the steps of: (a) forming an aqueous suspension comprising papermaking fibers; (b) depositing the aqueous suspension of papermaking fibers onto a forming fabric to form a wet tissue sheet; and, (c) dewatering and drying the wet tissue sheet to form a paper sheet, wherein a cationic water dispersible synthetic co-polymer containing a hydrophobic portion such that the hydrophobic portion is capable of demonstrating intra-molecular adhesive properties in the dry state while exhibiting an ability to debond the tissue sheet is added to the aqueous suspension of the paper-making fibers or topically to the wet tissue sheet at a consistency of about 80% or less, the cationic water dispersible synthetic co-polymer has the following general structure:
[0029] Wherein:
[0030] R 1 , R 2 , R 3 are independently H, C 1-4 alkyl radical, or mixtures thereof.
[0031] R 4 is a C 1 -C 8 alkyl radical or mixtures thereof.
[0032] Z 1 is a bridging radical attaching the R 4 functionality to the polymer backbone. Examples include, but are not limited to, —O—, —COO—, —OOC—, —CONH—, —NHCO—, and mixtures thereof.
[0033] Q 1 is a functional group containing a cationic quaternary ammonium radical.
[0034] Q 2 is an optional group comprising a non-ionic hydrophilic or water soluble monomer or monomers (and mixtures thereof) incorporated into the synthetic co-polymer so as to make the synthetic co-polymer more hydrophilic. Q 2 possesses limited ability to hydrogen or covalently bond to cellulose fibers, such bonding resulting in an increase in stiffness of the tissue sheet. Suitable hydrophilic monomers or water-soluble nonionic monomers for use in the cationic synthetic co-polymers of the present invention include, but are not limited to, monomers, such as, hydroxyalkyl acrylates and hydroxyalkyl methacrylates, such as hydroxyethyl methacrylate (HEMA); hydroxyethyl acrylate; polyalkoxyl acrylates, such as polyethyleneglycol acrylates; and, polyalkoxyl methacrylates, such as polyethyleneglycol methacrylates (“PEG-MA”). Other suitable hydrophilic monomers or water-soluble nonionic monomers for use in the ion-sensitive cationic synthetic copolymers of the present invention include, but are not limited to, diacetone acrylamide, N-vinylpyrrolidinone, and N-vinylformamide.
[0035] The mole ratio of z:x will specifically range from about 0:1 to about 4:1, more specifically from about 0:1 to about 1:1, and most specifically from about 0:1 to about 1:3. The mole ratio of (x+z):y may be from about 0.98:0.02 to about 1:1, and most specifically from about 0.95:0.05 to about 0.70:0.30.
[0036] The amount of the cationic synthetic co-polymer additive added to the papermaking fibers or the paper or tissue sheet may be from about 0.02 to about 5 weight percent, on a dry fiber basis, more specifically from about 0.05 to about 3 weight percent, and still more specifically from about 0.1 to about 2 weight percent. The synthetic co-polymer may be added to the fibers or paper or tissue sheet at any point in the process, but it can be particularly advantageous to add the synthetic co-polymer to the fibers while the fibers are suspended in water, before or after formation but prior to final drying of the sheet. This may include, for example, addition in the pulp mill or to the pulper, a machine chest, the headbox, or to the paper or tissue sheet prior to being dried where the consistency of the tissue sheet is about 80% or less.
[0037] In order to be an effective cationic synthetic co-polymer or cationic synthetic polymer additive suitable for use in tissue applications, the cationic synthetic co-polymer or cationic synthetic co-polymer additive should desirably be (1) water soluble or water dispersible; (2) safe (not toxic); and, (3) relatively economical. In addition to the foregoing factors, the cationic synthetic co-polymers and cationic synthetic co-polymer additives of the present invention, when used as a binder composition for a tissue sheet substrate, such as a facial, bath or towel product should be (4) processable on a commercial basis; i.e., may be applied relatively quickly on a large scale basis, such as by spraying (which thereby requires that the binder composition have a relatively low viscosity at high shear); and, (5) provide acceptable levels of sheet or substrate wettability. The cationic synthetic co-polymers and cationic synthetic co-polymer additives of the present invention and articles made therewith, especially facial tissue, bath-tissue and towels comprising the particular compositions set forth below, can meet any or all of the above criteria. Of course, it is not necessary for all of the advantages of the preferred embodiments of the present invention to be met to fall within the scope of the present invention.
DESCRIPTION OF THE DRAWINGS
[0038] [0038]FIG. 1 is a graph comparing GMT and slough values for a topical application to a wet sheet of a particular synthetic co-polymer of the present invention and controls.
[0039] [0039]FIG. 2 is a graph comparing GMT and softness values for a topical application to a wet sheet of a particular synthetic co-polymer of the present invention and controls.
[0040] [0040]FIG. 3 is a graph comparing slough and softness values for a topical application to a wet sheet of a particular synthetic co-polymer of the present invention and controls.
[0041] [0041]FIG. 4 is a graph comparing GMT and slough values for a topical application to a wet sheet of various synthetic co-polymers of the present invention and controls.
[0042] [0042]FIG. 5 is a graph comparing slough and softness values for a topical application to a wet sheet of various synthetic co-polymers of the present invention and controls.
[0043] [0043]FIG. 6 is a graph comparing GMT and slough values for bulk wet end application of various synthetic co-polymers of the present invention and controls.
[0044] [0044]FIG. 7 is a graph comparing slough and softness values for bulk wet end application of various synthetic co-polymers of the present invention and controls.
[0045] [0045]FIG. 8 is a schematic diagram of testing equipment used to measure lint and slough.
DETAILED DESCRIPTION OF THE INVENTION
[0046] Cationic Synthetic Co-polymer Formulations
[0047] Suitable hydrophobic monomers for incorporating a hydrophobic functionality into the cationic synthetic co-polymers of the present invention include, but are not limited to, alkyl acrylates, methacrylates, acrylamides, methacrylamides, tiglates and crotonates, including butyl acrylate, butyl methacrylate, methyl acrylate, methyl methacrylate, ethyl acrylate, ethyl methacrylate, 1-Ethylhexyl tiglate, t-butyl acrylate, butyl crotonate, butyl tiglate, sec-Butyl tiglate, Hexyl tiglate, Isobutyl tiglate, hexyl crotonate, butyl crotonate, n-butyl acrylamide, t-butyl acrylamide, N-(Butoxymethyl)acrylamide, N-(Isobutoxymethyl) acrylamide, and the like including mixtures of the monomers all of which are known commercially available materials. Also known are various vinyl ethers including, but not limited to, n-butyl vinyl ether, 2-ethylhexyl vinyl ether, and the corresponding esters including vinyl pivalate, vinyl butyrate, 2-ethylhexanoate, and the like including mixtures of the monomers, all of which are suitable for incorporation of the hydrophobic aliphatic hydrocarbon moiety.
[0048] Suitable monomers for incorporating a cationic charge functionality into the synthetic co-polymer include, but are not limited to, [2-(methacryloyloxy)ethyl]trimethylammonium methosulfate (METAMS); dimethyldiallyl ammonium chloride (DMDAAC); 3-acryloamido-3-methyl butyl trimethyl ammonium chloride (AMBTAC); trimethylamino methacrylate; vinyl benzyl trimethyl ammonium chloride (VBTAC); 2-[(acryloyloxy)ethyl]trimethylammonium chloride; [2-(methacryloyloxy)ethyl]trimethylammonium chloride.
[0049] Examples of preferred cationic monomers for the cationic synthetic co-polymers of the present invention are [2-(methacryloyloxy)ethyl]trimethyl ammonium chloride, [2(methacryloyloxy)ethyl]trimethyl ammonium methosulfate, [2-(methacryloyloxy)ethyl]trimethyl ammonium ethosulfate.
[0050] Suitable hydrophilic monomers or water-soluble nonionic monomers for use in the cationic synthetic co-polymers of the present invention include, but are not limited to N- and N,N-substituted acrylamide and methacrylamide based monomers, such as N,N-dimethyl acrylamide, N-ethyl acrylamide, N-isopropyl acrylamide, and hydroxymethyl acrylamide; acrylate or methacrylate based monomers, such as, hydroxyalkyl acrylates; hydroxyalkyl methacrylates, such as hydroxyethyl methacrylate (HEMA); hydroxyethyl acrylate; polyalkoxyl acrylates, such as polyethyleneglycol acrylates; and, polyalkoxyl methacrylates, such as polyethyleneglycol methacrylates (“PEG-MA”). Other suitable hydrophilic monomers or water-soluble nonionic monomers for use in the ion-sensitive cationic synthetic co-polymers of the present invention include, but are not limited to, N-vinylpyrrolidinone and N-vinylformamide.
[0051] For the cationic synthetic co-polymers of the present invention the mole % of hydrophobic monomers will range from about 40 mole % to about 98 mole % of the total monomer composition, the amount of cationic monomers will range from about 2 mole % to about 50 mole % of the total monomer composition. The amount of optional hydrophilic monomers will range from about 0 mole % to about 58 mole % of the total monomer composition. Most preferably, the mole percent of hydrophobic monomers is from about 50 mole % to about 95 mole % of the total monomer composition, the mole % of cationic monomers is most preferably from about 5 mole % to about 30 mole % of the total monomer composition, and the amount of optional hydrophilic monomers is most preferably from about 0 mole % to about 20 mole % of the total monomer composition.
[0052] The synthetic co-polymers of the present invention may have an average molecular weight average molecular weight ranging from about 10,000 to about 5,000,000. More specifically, the cationic water dispersible synthetic co-polymers of the present invention have a weight average molecular weight ranging from about 25,000 to about 2,000,000, or, more specifically still, from about 50,000 to about 1,000,000.
[0053] Another advantage to the disclosed cationic synthetic co-polymers is ability to produce sheets having low stiffness due to relatively low glass transition temperatures. While the cationic synthetic co-polymers of the present invention may have a wide range of glass transition temperature the glass transition temperature may be about 100° C. or less, more specifically about 70° C. or less, and most specifically about 40° C. or less. Some of the cationic synthetic co-polymers of the present invention may show more than one glass transition temperature. In such cases, the glass transition temperature of the lowest glass transition temperature may be about 100° C. or less, more specifically about 70° C. or less, and most specifically about 40° C. or less.
[0054] The cationic synthetic co-polymers of the present invention may be prepared according to a variety of polymerization methods, desirably a solution polymerization method. Suitable solvents for the polymerization method include, but are not limited to, lower alcohols such as methanol, ethanol and propanol; a mixed solvent comprising water and one or more lower alcohols mentioned above; and, a mixed solvent comprising water and one or more lower ketones such as acetone or methyl ethyl ketone.
[0055] In the polymerization methods which may be utilized in the present invention, any free radical polymerization initiator may be used. Selection of a particular polymerization initiator may depend on a number of factors including, but not limited to, the polymerization temperature, the solvent, and the monomers used. Suitable polymerization initiators for use in the present invention include, but are not limited to, 2,2′-azobisisobutyronitrile, 2,2′-azobis(2-methylbutyronitrile), 2,2′-azobis(2,4-dimethylvaleronitrile), 2,2′-azobis(2-amidinopropane)dihydrochloride, 2,2′-azobis(N,N′-dimethyleneisobutylamidine), potassium persulfate, ammonium persulfate, and aqueous hydrogen peroxide. The amount of polymerization initiator may desirably range from about 0.01 to about 5 weight percent based on the total weight of monomer present.
[0056] The polymerization temperature may vary depending on the polymerization solvent, monomers, and polymerization initiator used, but in general, ranges from about 20° C. to about 90° C. The polymerization time generally ranges from about 2 to about 8 hours.
[0057] The cationic synthetic co-polymer formulations of the present invention may also be delivered in emulsion form, whereby an aqueous polymerization process is used in conjunction with a surfactant or set of surfactants, such polymerization methods being known to those skilled in the art. The surfactants may be cationic or non-ionic, but more specifically non-ionic.
[0058] The amount of the cationic synthetic co-polymer additive added to the papermaking fibers or the paper or tissue sheet may be from about 0.01 to about 5 weight percent, on a dry fiber basis, more specifically from about 0.05 to about 3 weight percent, and still more specifically from about 0.1 to about 2 weight percent. The cationic synthetic co-polymer may be added to the papermaking fibers or the paper or tissue sheet at any point in the process. In one embodiment, the cationic synthetic co-polymers of the present invention may be added after the tissue sheet is formed, more specifically, to an existing wet tissue sheet. The solids level of the wet tissue sheet is preferably about 80% or lower (i.e., the tissue sheet comprises about 20 grams of dry solids and about 80 grams of water). More specifically, the solids level of the tissue sheet during the application of the cationic synthetic co-polymers may be most specifically about 60% or less, and most specifically about 50% or less. The application of the cationic synthetic co-polymer to the tissue sheet via this process may be accomplished by any method known in the art including but not limited to:
[0059] A spray applied to the fibrous tissue sheet. For example, spray nozzles may be mounted over a moving wet tissue sheet to apply a desired dose of a synthetic co-polymer chemical additive solution to the wet tissue sheet. Nebulizers can also be used to apply a light mist to a surface of a wet tissue sheet.
[0060] Non-contact printing methods such as ink jet printing, digital printing of any kind, and the like.
[0061] Coating onto one or both surfaces of the wet tissue sheet, such as blade coating, air knife coating, short dwell coating, cast coating, and the like.
[0062] Extrusion from a die head such as UFD spray tips, such as available from ITWDynatec of Henderson, Tenn., of the cationic synthetic co-polymer or cationic synthetic co-polymer additive in the form of a solution, a dispersion or emulsion, or a viscous mixture.
[0063] Impregnation of the wet tissue sheet with a solution or slurry, wherein the compound penetrates a significant distance into the thickness of the wet tissue sheet, such as about 20% or greater of the thickness of the wet tissue sheet, more specifically about 30% or greater, and most specifically about 70% or greater of the thickness of the wet tissue sheet, including completely penetrating the wet tissue sheet throughout the full extent of its thickness. One useful method for impregnation of a wet tissue sheet is the Hydra-Sizers system, produced by Black Clawson Corp., Watertown, N.Y., as described in “New Technology to Apply Starch and Other Additives,” Pulp and Paper Canada, 100(2): T42-T44 (February 1999). This system consists of a die, an adjustable support structure, a catch pan, and an additive supply system. A thin curtain of descending liquid or slurry is created which contacts the moving tissue sheet beneath it. Wide ranges of applied doses of the coating material, such as the cationic synthetic co-polymer, or cationic synthetic co-polymer additive, may be achieved with good runnability. The system may also be applied to curtain coat a relatively dry tissue sheet, such as a tissue sheet just before or after creping.
[0064] Foam application of the cationic synthetic co-polymer or cationic synthetic co-polymer additive to the wet tissue sheet (e.g., foam finishing), either for topical application or for impregnation of the cationic synthetic co-polymer or cationic synthetic co-polymer additive into the wet tissue sheet under the influence of a pressure differential (e.g., vacuum-assisted impregnation of the foam). Principles of foam application of additives such as binder agents are described in U.S. Pat. No. 4,297,860, issued on Nov. 3, 1981 to Pacifici et al. and U.S. Pat. No. 4,773,110, issued on Sep. 27, 1988 to G. J. Hopkins, the disclosures of both which are herein incorporated by reference to the extent that they are non-contradictory herewith.
[0065] Application of the cationic synthetic co-polymer or cationic synthetic co-polymer additive by spray or other means to a moving belt or fabric which in turn contacts the tissue sheet to apply the cationic synthetic co-polymer or cationic synthetic co-polymer additive to the tissue sheet, such as is disclosed in WO 01/49937 under the name of S. Eichhorn, published on Jun. 12, 2001.
[0066] The cationic synthetic co-polymer or cationic synthetic co-polymer additive may also be added prior to formation of the tissue sheet such as when the fibers are suspended in water. This may include, for example, addition in the pulp mill or to the pulper, a machine chest, the headbox or to the tissue sheet prior to being dried where the consistency is about 80% or less.
[0067] The most preferred means for addition prior to the tissue sheet formation is direct addition to a fibrous slurry, such as by injection of the cationic synthetic co-polymer or cationic synthetic co-polymer additive into a fibrous slurry prior to entry in the headbox. Slurry consistency can be from about 0.2% to about 50%, specifically from about 0.2% to about 10%, more specifically from about 0.3% to about 5%, and most specifically from about 1% to about 4%.
[0068] Application of the cationic synthetic co-polymer or cationic synthetic co-polymer additive to individualized fibers. For example, comminuted or flash dried fibers may be entrained in an air stream combined with an aerosol or spray of the cationic synthetic co-polymer or cationic synthetic co-polymer additive to treat individual fibers prior to incorporation of the treated fibers into a tissue sheet or other fibrous product.
[0069] The tissue sheet comprising the cationic synthetic co-polymers of the present invention may be blended or layered sheets, wherein either a heterogeneous or homogeneous distribution of fibers is present in the z-direction of the sheet. In some embodiments, the cationic synthetic co-polymers may be added to all the fibers in the tissue sheet. In other embodiments, the cationic synthetic co-polymers may be added to only selective fibers in the tissue sheet, such methods being well known to those skilled in the art. In a specific embodiment of the present invention, the tissue sheet is a layered tissue sheet comprising two or more layers comprising distinct hardwood and softwood layers, wherein the cationic synthetic co-polymers of the present invention are added to only the hardwood fibers. In another embodiment, the cationic synthetic co-polymers of the present invention may be added to all the fibers.
[0070] The tissue sheet to be treated may be made by any method known in the art. The tissue sheet may be wetlaid, such as tissue sheet formed with known paper-making techniques wherein a dilute aqueous fiber slurry is disposed on a moving wire to filter out the fibers and form an embryonic tissue sheet which is subsequently dewatered by combinations of units including suction boxes, wet presses, dryer units, and the like. Examples of known dewatering and other operations are disclosed in U.S. Pat. No. 5,656,132, issued on Aug. 12, 1997 to Farrington, Jr. et al. Capillary dewatering may also be applied to remove water from the tissue sheet, as disclosed in U.S. Pat. No. 5,598,643, issued on Feb. 4, 1997 and U.S. Pat. No. 4,556,450, issued on Dec. 3, 1985, both to S. C. Chuang et al., the disclosures of both which are herein incorporated by reference to the extent that they are non-contradictory herewith.
[0071] Drying operations can include drum drying, through drying, steam drying such as superheated steam drying, displacement dewatering, Yankee drying, infrared drying, microwave drying, radiofrequency drying in general, and impulse drying, as disclosed in U.S. Pat. No. 5,353,521, issued on Oct. 11, 1994 to Orloff and U.S. Pat. No. 5,598,642, issued on Feb. 4, 1997 to Orloff et al., the disclosures of both which are herein incorporated by reference to the extent that they are non-contradictory herewith. Other drying technologies may be used, such as methods employing differential gas pressure include the use of air presses as disclosed U.S. Pat. No. 6,096,169, issued on Aug. 1, 2000 to Hermans et al. and U.S. Pat. No. 6,143,135, issued Nov. 7, 2000 to Hada et al., the disclosure of both which are herein incorporated by reference to the extent they are non-contradictory herewith. Also relevant are the paper machines disclosed in U.S. Pat. No. 5,230,776, issued on Jul. 27, 1993 to 1. A. Andersson et al.
[0072] For tissue sheets, both creped and uncreped methods of manufacture may be used. Uncreped tissue production is disclosed in U.S. Pat. No. 5,772,845 issued on Jun. 30, 1998 to Farrington, Jr. et al., the disclosure of which is herein incorporated by reference to the extent that they are non-contradictory herewith. Creped tissue production is disclosed in U.S. Pat. No. 5,637,194, issued on Jun. 10, 1997 to Ampulski et al.; U.S. Pat. No. 4,529,480, issued on Jul. 16, 1985 to Trokhan; U.S. Pat. No. 6,103,063, issued on Aug. 15, 2000 to Oriaran et al.; and, U.S. Pat. No. 4,440,597, issued on Apr. 3, 1984 to Wells et al., the disclosures of all which are herein incorporated by reference to the extent that they are non-contradictory herewith. Also suitable for application of the synthetic co-polymers and synthetic co-polymer chemical additives of the present invention are tissue sheets that are pattern densified or imprinted, such as the tissue sheets disclosed in any of the following U.S. Pat. No. 4,514,345, issued on Apr. 30, 1985 to Johnson et al.; U.S. Pat. No. 4,528,239, issued on Jul. 9, 1985 to Trokhan; U.S. Pat. No. 5,098,522, issued on Mar. 24, 1992; U.S. Pat. No. 5,260,171, issued on Nov. 9, 1993 to Smurkoski et al.; U.S. Pat. No. 5,275,700, issued on Jan. 4, 1994 to Trokhan; U.S. Pat. No. 5,328,565, issued on Jul. 12, 1994 to Rasch et al.; U.S. Pat. No. 5,334,289, issued on Aug. 2, 1994 to Trokhan et al.; U.S. Pat. No. 5,431,786, issued on Jul. 11, 1995 to Rasch et al.; U.S. Pat. No. 5,496,624, issued on Mar. 5, 1996 to Steltjes, Jr. et al.; U.S. Pat. No. 5,500,277, issued on Mar. 19, 1996 to Trokhan et al.; U.S. Pat. No. 5,514,523, issued on May 7, 1996 to Trokhan et al.; U.S. Pat. No. 5,554,467, issued on Sep. 10, 1996, to Trokhan et al.; U.S. Pat. No. 5,566,724, issued on Oct. 22, 1996 to Trokhan et al.; U.S. Pat. No. 5,624,790, issued on Apr. 29, 1997 to Trokhan et al.; and, U.S. Pat. No. 5,628,876, issued on May 13, 1997 to Ayers et al., the disclosures of which are incorporated herein by reference to the extent that they are non-contradictory herewith. Such imprinted tissue sheets may have a network of densified regions that have been imprinted against a drum dryer by an imprinting fabric, and regions that are relatively less densified (e.g., “domes” in the tissue sheet) corresponding to deflection conduits in the imprinting fabric, wherein the tissue sheet superposed over the deflection conduits was deflected by an air pressure differential across the deflection conduit to form a lower-density pillow-like region or dome in the tissue sheet.
[0073] The term “tissue” as used herein is differentiated from other paper or tissue products in terms of its bulk. The bulk of the tissue products of the present invention is calculated as the quotient of the Caliper (hereinafter defined), expressed in microns, divided by the basis weight, expressed in grams per square meter. The resulting bulk is expressed as cubic centimeters per gram. Writing papers, newsprint and other such papers have higher strength and density (low bulk) in comparison to tissue products which tend to have much higher calipers for a given basis weight. For writing and printing papers, both bulk and surface strength are extremely important as well as high stiffness. The use of bulk or surface debonders to create bulk in papers other than tissue products goes against maximizing bulk and surface strength in printing papers. The tissue products of the present invention have a bulk about 2 cm 3 /g or greater, more specifically about 2.5 cm 3 /g or greater, and still more specifically about 3 cm 3 /g or greater.
[0074] Optional Chemical Additives
[0075] Optional chemical additives may also be added to the aqueous paper-making furnish or to the embryonic tissue sheet to impart additional benefits to the tissue product and process and are not antagonistic to the intended benefits of the present invention. The following materials are included as examples of additional chemicals that may be applied to the tissue sheet with the cationic synthetic co-polymers and cationic synthetic co-polymer additives of the present invention. The chemicals are included as examples and are not intended to limit the scope of the present invention. Such chemicals may be added at any point in the papermaking process, such as before or after addition of the cationic synthetic co-polymers and/or cationic synthetic co-polymer additives of the present invention. They may also be added simultaneously with the cationic copolymers and/or cationic synthetic co-polymer additives, either blended with the cationic synthetic co-polymers and/or cationic synthetic co-polymer additives of the present invention or as separate additives.
[0076] Charge Control Agents
[0077] Charge promoters and control agents are commonly used in the paper-making process to control the zeta potential of the papermaking furnish in the wet end of the process. These species may be anionic or cationic, most usually cationic, and may be either naturally occurring materials such as alum or low molecular weight high charge density synthetic polymers typically of molecular weight of about 500,000 or less. Drainage and retention aids may also be added to the furnish to improve formation, drainage and fines retention. Included within the retention and drainage aids are microparticle systems containing high surface area, high anionic charge density materials.
[0078] Strength Agents
[0079] Wet and dry strength agents may also be applied to the tissue sheet. As used herein, “wet strength agents” refer to materials used to immobilize the bonds between fibers in the wet state. Typically, the means by which fibers are held together in paper and tissue products involve hydrogen bonds and sometimes combinations of hydrogen bonds and covalent and/or ionic bonds. In the present invention, it may be useful to provide a material that will allow bonding of fibers in such a way as to immobilize the fiber-to-fiber bond points and make them resistant to disruption in the wet state. In this instance, the wet state usually will mean when the product is largely saturated with water or other aqueous solutions, but could also mean significant saturation with body fluids such as urine, blood, mucus, menses, runny bowel movement, lymph, and other body exudates.
[0080] Any material that when added to a tissue sheet or sheet results in providing the tissue sheet with a mean wet geometric tensile strength:dry geometric tensile strength ratio in excess of about 0.1 will, for purposes of the present invention, be termed a wet strength agent. Typically these materials are termed either as permanent wet strength agents or as “temporary” wet strength agents. For the purposes of differentiating permanent wet strength agents from temporary wet strength agents, the permanent wet strength agents will be defined as those resins which, when incorporated into paper or tissue products, will provide a paper or tissue product that retains more than 50% of its original wet strength after exposure to water for a period of at least five minutes. Temporary wet strength agents are those which show about 50% or less than, of their original wet strength after being saturated with water for five minutes. Both classes of wet strength agents find application in the present invention. The amount of wet strength agent added to the pulp fibers may be about 0.1 dry weight percent or greater, more specifically about 0.2 dry weight percent or greater, and still more specifically from about 0.1 to about 3 dry weight percent, based on the dry weight of the fibers.
[0081] Permanent wet strength agents will typically provide a more or less long-term wet resilience to the structure of a tissue sheet. In contrast, the temporary wet strength agents will typically provide tissue sheet structures that had low density and high resilience, but would not provide a structure that had long-term resistance to exposure to water or body fluids.
[0082] Wet and Temporary Wet Strength Agents
[0083] The temporary wet strength agents may be cationic, nonionic or anionic. Such compounds include PAREZ™ 631 NC and PAREZ®) 725 temporary wet strength resins that are cationic glyoxylated polyacrylamide available from Cytec Industries (West Paterson, N.J.). This and similar resins are described in U.S. Pat. No. 3,556,932, issued on Jan. 19, 1971 to Coscia et al. and U.S. Pat. No. 3,556,933, issued on Jan. 19, 1971 to Williams et al. Hercobond 1366, manufactured by Hercules, Inc., located at Wilmington, Del., is another commercially available cationic glyoxylated polyacrylamide that may be used in accordance with the present invention. Additional examples of temporary wet strength agents include dialdehyde starches such as Cobond® 1000 from National Starch and Chemcial Company and other aldehyde containing polymers such as those described in U.S. Pat. No. 6,224,714 issued on May 1, 2001 to Schroeder et al.; U.S. Pat. No. 6,274,667 issued on Aug. 14, 2001 to Shannon et al.; U.S. Pat. No. 6,287,418 issued on Sep. 11, 2001 to Schroeder et al.; and, U.S. Pat. No. 6,365,667 issued on Apr. 2, 2002 to Shannon et al., the disclosures of which are herein incorporated by reference to the extend they are non-contradictory herewith.
[0084] Permanent wet strength agents comprising cationic oligomeric or polymeric resins may be used in the present invention. Polyamide-polyamine-epichlorohydrin type resins such as KYMENE 557H sold by Hercules, Inc., located at Wilmington, Del., are the most widely used permanent wet-strength agents and are suitable for use in the present invention. Such materials have been described in the following U.S. Pat. No. 3,700,623 issued on Oct. 24, 1972 to Keim; U.S. Pat. No. 3,772,076 issued on Nov. 13, 1973 to Keim; U.S. Pat. No. 3,855,158 issued on Dec. 17, 1974 to Petrovich et al.; U.S. Pat. No. 3,899,388 issued on Aug. 12, 1975 to Petrovich et al.; U.S. Pat. No. 4,129,528 issued on Dec. 12, 1978 to Petrovich et al.; U.S. Pat. No. 4,147,586 issued on Apr. 3, 1979 to Petrovich et al.; and, U.S. Pat. No. 4,222,921 issued on Sep. 16, 1980 to van Eenam. Other cationic resins include polyethylenimine resins and aminoplast resins obtained by reaction of formaldehyde with melamine or urea. It is often advantageous to use both permanent and temporary wet strength resins in the manufacture of tissue products with such use being recognized as falling within the scope of the present invention.
[0085] Dry Strength Agents
[0086] Dry strength agents may also be applied to the tissue sheet without affecting the performance of the disclosed cationic synthetic co-polymers of the present invention. Such materials used as dry strength agents are well known in the art and include but are not limited to modified starches and other polysaccharides such as cationic, amphoteric, and anionic starches and guar and locust bean gums, modified polyacrylamides, carboxymethylcellulose, sugars, polyvinyl alcohol, chitosans, and the like. Such dry strength agents are typically added to a fiber slurry prior to tissue sheet formation or as part of the creping package. It may at times, however, be beneficial to blend the dry strength agent with the cationic synthetic co-polymers of the present invention and apply the two chemicals simultaneously to the tissue sheet.
[0087] Additional Softening Agents
[0088] At times it may be advantageous to add additional debonders or softening chemistries to a tissue sheet. Examples of such debonders and softening chemistries are broadly taught in the art. Exemplary compounds include the simple quaternary ammonium salts having the general formula (R 1′ ) 4-b —N + —(R 1″ ) b X − wherein R1′ is a C1-6 alkyl group, R1″ is a C14-C22 alkyl group, b is an integer from 1 to 3 and X− is any suitable counterion. Other similar compounds include the monoester, diester, monoamide and diamide derivatives of the simple quaternary ammonium salts. A number of variations on these quaternary ammonium compounds are known and should be considered to fall within the scope of the present invention. Additional softening compositions include cationic oleyl imidazoline materials such as methyl-1-oleyl amidoethyl-2-oleyl imidazolinium methylsulfate commercially available as Mackernium DC-183 from McIntyre Ltd., located in University Park, III and Prosoft TQ-1003 available from Hercules, Inc. Such softeners may also incorporate a humectant or a plasticizer such as a low molecular weight polyethylene glycol (molecular weight of about 4,000 daltons or less) or a polyhydroxy compound such as glycerin or propylene glycol. While these softeners may be applied to the fibers while in slurry prior to sheet formation, the cationic synthetic copolymers of the present invention typically provide sufficient debonding and softness improvement so as not to require use of additional bulk softening agents.
[0089] However, it may be particularly advantageous to add such softening agents simultaneously with the cationic synthetic co-polymers of the present invention to a formed tissue sheet at a consistency of about 80% or less. In such situations, dilute solutions of the softening composition and cationic synthetic co-polymer are blended directly and then topically applied to the wet tissue sheet. It is believed in this manner that tactile softness of the tissue sheet and resulting tissue products may be improved due to presence of the additional softening compound. An especially preferred topical softener for this application is polysiloxane. The use of polysiloxanes to soften tissue sheets is broadly taught in the art. A large variety of polysiloxanes are available that are capable of enhancing the tactile properties of the finished tissue sheet. Any polysiloxane capable of enhancing the tactile softness of the tissue sheet is suitable for incorporation in this manner so long as so long as solutions or emulsions of the softener and polysiloxane are compatible, that is when mixed they do not form gels, precipitates or other physical defects that would preclude application to the tissue sheet.
[0090] Examples of suitable polysiloxanes include but are not limited to linear polydialkyl polysiloxanes such as the DC-200 fluid series available from Dow Corning, Inc., Midland, Mich. as well as the organo-reactive polydimethyl siloxanes such as the preferred amino functional polydimethyl siloxanes. Examples of suitable polysiloxanes include those described in U.S. Pat. No. 6,054,020 issued on Apr. 25, 2000 to Goulet et al. and U.S. Pat. No. 6,432,270 issued on Aug. 13, 2002 to Liu et al., the disclosures of which are herein incorporated by reference to the extent that they are non-contradictory herewith. Additional exemplary aminofunctional polysiloxanes are the Wetsoft CTW family manufactured and sold by Wacker Chemie, Munich, Germany.
[0091] Miscellaneous Agents
[0092] It may be desirable to treat a tissue sheet with additional types of chemicals. Such chemicals include, but are not limited to, absorbency aids usually in the form of cationic, anionic, or non-ionic surfactants, humectants and plasticizers such as low molecular weight polyethylene glycols and polyhydroxy compounds such as glycerin and propylene glycol.
[0093] In general, the cationic synthetic co-polymers of the present invention may be used in conjunction with any known materials and chemicals that are not antagonistic to its intended use. Examples of such materials and chemicals include, but are not limited to, odor control agents, such as odor absorbents, activated carbon fibers and particles, baby powder, baking soda, chelating agents, zeolites, perfumes or other odor-masking agents, cyclodextrin compounds, oxidizers, and the like. Superabsorbent particles, synthetic fibers, or films may also be employed. Additional options include cationic dyes, optical brighteners, polysiloxanes and the like. A wide variety of other materials and chemicals known in the art of papermaking and tissue production may be included in the tissue sheets of the present invention including lotions and other materials providing skin health benefits.
[0094] The application point for such materials and chemicals is not particularly relevant to the present invention and such materials and chemicals may be applied at any point in the tissue manufacturing process. This includes pre-treatment of pulp, co-application in the wet end of the process, post treatment after drying but on the tissue machine and topical post treatment.
[0095] A surprising aspect of the present invention is that despite use of the hydrophobically modified cationic synthetic co-polymers, the tissue sheets still remain absorbent. The Wet Out Time (hereinafter defined) for treated tissue sheets of the present invention may be about 180 seconds or less, more specifically about 150 seconds or less, still more specifically about 120 seconds or less, and still more specifically about 90 seconds or less. As used herein, the term “Wet Out Time” is related to absorbency and is the time it takes for a given sample of a tissue sheet to completely wet out when placed in water.
[0096] Experimental
[0097] Basis Weight Determination (Tissue)
[0098] The basis weight and bone dry basis weight of the tissue sheet specimens was determined using a modified TAPPI T410 procedure. As is basis weight samples were conditioned at 23° C.±1° C. and 50±2% relative humidity for a minimum of 4 hours. After conditioning a stack of 16—3″×3″ samples was cut using a die press and associated die. This represents a tissue sheet sample area of 144 in 2 . Examples of suitable die presses are TMI DGD die press manufactured by Testing Machines, Inc., Islandia, N.Y., or a Swing Beam testing machine manufactured by USM Corporation, Wilmington, Mass. Die size tolerances are ±0.008 inches in both directions. The specimen stack is then weighed to the nearest 0.001 gram on a tared analytical balance. The basis weight in pounds per 2880 ft 2 is then calculated using the following equation:
Basis weight=stack wt . in grams/454*2880
[0099] The bone dry basis weight is obtained by weighing a sample can and sample can lid the nearest 0.001 grams (this weight is A). The sample stack is placed into the sample can and left uncovered. The uncovered sample can and stack along with the sample can lid is placed in a 105° C.±2° C. oven for a period of 1 hour±5 minutes for sample stacks weighing less than 10 grams and at least 8 hours for sample stacks weighing 10 grams or greater. After the specified oven time has lapsed, the sample can lid is placed on the sample can and the sample can is removed from the oven. The sample can is allowed to cool to approximately ambient temperature but no more than 10 minutes. The sample can, sample can lid and sample stack are then weighed to the nearest 0.001 gram (this weight is C). The bone dry basis weight in pounds/2880 ft 2 is calculated using the following equation:
Bone Dry BW= ( C−A )/454*2880
[0100] Dry Tensile (tissue):
[0101] The Geometric Mean Tensile (GMT) strength test results are expressed as grams-force per 3 inches of sample width. GMT is computed from the peak load values of the MD (machine direction) and CD (cross-machine direction) tensile curves, which are obtained under laboratory conditions of 23.0° C.±1.0° C., 50.0±2.0% relative humidity, and after the tissue sheet has equilibrated to the testing conditions for a period of not less than four hours. Testing is conducted on a tensile testing machine maintaining a constant rate of elongation, and the width of each specimen tested was 3 inches. The “jaw span” or the distance between the jaws, sometimes referred to as gauge length, is 2.0 inches (50.8 mm). The crosshead speed is 10 inches per minute (254 mm/min.) A load cell or full-scale load is chosen so that all peak load results fall between 10 and 90 percent of the full-scale load. In particular, the results described herein were produced on an Instron 1122 tensile frame connected to a Sintech data acquisition and control system utilizing IMAP software running on a “486 Class” personal computer. This data system records at least 20 load and elongation points per second. A total of 10 specimens per sample are tested with the sample mean being used as the reported tensile value. The geometric mean tensile is calculated from the following equation:
GMT =( MD Tensile* CD Tensile) 1/2
[0102] To account for small variations in basis weight, GMT values were then corrected to the 18.5 pounds/2880 ft 2 target basis weight using the following equation:
Corrected GMT =Measured GMT *(18.5/Bone Dry Basis Weight)
[0103] Caliper:
[0104] The term “caliper” as used herein is the thickness of a single tissue sheet, and may either be measured as the thickness of a single tissue sheet or as the thickness of a stack of ten tissue sheets and dividing the ten tissue sheet thickness by ten, where each sheet within the stack is placed with the same side up. Caliper is expressed in microns. Caliper was measured in accordance with TAPPI test methods T402 “Standard Conditioning and Testing Atmosphere For Paper, Board, Pulp Handsheets and Related Products” and T411 om-89 “Thickness (caliper) of Paper, Paperboard, and Combined Board” optionally with Note 3 for stacked tissue sheets. The micrometer used for carrying out T411 om-89 is a Bulk Micrometer (TMI Model 49-72-00, Amityville, N.Y.) or equivalent having an anvil diameter of 4{fraction (1/16)} inches (103.2 millimeters) and an anvil pressure of 220 grams/square inch (3.3 g kilo Pascals).
[0105] Lint and Slough Measurement:
[0106] In order to determine the abrasion resistance, or tendency of the fibers to be rubbed from the tissue sheet when handled, each sample was measured by abrading the tissue specimens via the following method. This test measures the resistance of a material to an abrasive action when the material is subjected to a horizontally reciprocating surface abrader. The equipment and method used is similar to that described in U.S. Pat. No. 4,326,000, issued on Apr. 20, 1982 to Roberts, Jr. and assigned to the Scott Paper Company, the disclosure of which is herein incorporated by reference to the extent that it is non-contradictory herewith. All tissue sheet samples were conditioned at 23° C.±1° C. and 50+2% relative humidity for a minimum of 4 hours. FIG. 8 is a schematic diagram of the test equipment. Shown is the abrading spindle or mandrel 5 , a double arrow 6 showing the motion of the mandrel 5 , a sliding clamp 7 , a slough tray 8 , a stationary clamp 9 , a cycle speed control 10 , a counter 11 , and start/stop controls 12 .
[0107] The abrading spindle 5 consists of a stainless steel rod, 0.5″ in diameter with the abrasive portion consisting of a 0.005″ deep diamond pattern knurl extending 4.25″ in length around the entire circumference of the rod. The abrading spindle 5 is mounted perpendicularly to the face of the instrument 3 such that the abrasive portion of the abrading spindle 5 extends out its entire distance from the face of the instrument 3 . On each side of the abrading spindle 5 is located a pair of clamps 7 and 9 , one movable 7 and one fixed 9 , spaced 4″ apart and centered about the abrading spindle 5 . The movable clamp 7 (weighing approximately 102.7 grams) is allowed to slide freely in the vertical direction, the weight of the movable clamp 7 providing the means for insuring a constant tension of the tissue sheet sample over the surface of the abrading spindle 5 .
[0108] Using a JDC-3 or equivalent precision cutter, available from Thwing-Albert Instrument Company, located at Philadelphia, Pa., the tissue sheet sample specimens are cut into 3″±0.05″ wide×7″ long strips (note: length is not critical as long as specimen can span distance so as to be inserted into the clamps A & B). For tissue sheet samples, the MD direction corresponds to the longer dimension. Each tissue sheet sample is weighed to the nearest 0.1 mg. One end of the tissue sheet sample is clamped to the fixed clamp 9 , the sample then loosely draped over the abrading spindle or mandrel 5 and clamped into the sliding clamp 7 . The entire width of the tissue sheet sample should be in contact with the abrading spindle 5 . The sliding clamp 7 is then allowed to fall providing constant tension across the abrading spindle 5 .
[0109] The abrading spindle 5 is then moved back and forth at an approximate 15 degree angle from the centered vertical centerline in a reciprocal horizontal motion against the tissue sheet sample for 20 cycles (each cycle is a back and forth stroke), at a speed of 170 cycles per minute, removing loose fibers from the surface of the tissue sheet sample. Additionally the spindle rotates counter clockwise (when looking at the front of the instrument) at an approximate speed of 5 RPMs. The tissue sheet sample is then removed from the jaws 7 and 9 and any loose fibers on the surface of the tissue sheet sample are removed by gently shaking the tissue sheet sample. The tissue sheet sample is then weighed to the nearest 0.1 mg and the weight loss calculated. Ten tissue sheet specimen per sample are tested and the average weight loss value in mg recorded. The result for each tissue sheet sample was compared with a control sample containing no chemicals. Where a 2-layered tissue sheet sample is measured, placement of the tissue sheet sample should be such that the hardwood portion is against the abrading surface.
[0110] Wet Out Time
[0111] The Wet Out Time of a tissue sheet treated in accordance with the present invention is determined by cutting 20 sheets of the tissue sheet sample into 2.5 inch squares. The number of sheets of the tissue sheet sample used in the test is independent of the number of plies per sheet of the tissue sheet sample. The 20 square sheets of the tissue sheet sample are stacked together and stapled at each corner to form a pad of the tissue sheet sample. The pad of the tissue sheet sample is held close to the surface of a constant temperature distilled water bath (23° C.±2° C.), which is the appropriate size and depth to ensure the saturated pad of the tissue sheet sample does not contact the bottom of the water bath container and the top surface of the distilled water of the water bath at the same time, and dropped flat onto the surface of the distilled water, with staple points on the pad of the tissue sheet sample facing down. The time necessary for the pad of the tissue sheet sample to become completely saturated, measured in seconds, is the Wet Out Time for the tissue sheet sample and represents the absorbent rate of the tissue sheet sample. Increases in the Wet Out Time represent a decrease in absorbent rate of the tissue sheet sample.
[0112] Softness:
[0113] Softness of tissue sheets and/or tissue products is determined from sensory panel testing. The testing is performed by trained panelists who rub the formed tissue sheets and/or tissue products and compare the softness attributes of the tissue sheets and/or tissue products to the same softness attributes of high and low softness control standards. After comparing these characteristics to the standards, the panelists assign a value for each of the tissue sheets' and/or tissue products' softness attributes. From these values an overall softness of the tissue sheets and/or tissue products determined on a scale from 1 (least soft) to 16 (most soft). The higher the number, the softer the tissue sheet and/or tissue product. In general, a difference of less than 0.5 in the panel softness value is not statistically significant.
EXAMPLES
Example 1
[0114] Example 1 demonstrates the preparation of a blended (non-layered) tissue basesheet. The blended tissue basesheet was made according to the following procedure. About 45.5 pounds (oven dry basis) of eucalyptus hardwood kraft fiber and about 24.5 pounds (oven dry basis) of northern softwood kraft fiber were dispersed in a pulper for about 30 minutes at a consistency of about 3%. The blended thick stock pulp slurry was refined for 10 minutes and then passed to a machine chest where the thick stock pulp slurry was diluted to a consistency of about 1%. Kymene 6500, a commercially available PAE wet strength resin from Hercules, Inc., was added to the pulp slurry in the machine chest at a rate of about 4 pounds of dry chemical per ton of dry fiber. The stock pulp slurry was further diluted to about 0.1 percent consistency prior to forming and deposited from an unlayered headbox onto a fine forming fabric having a velocity of about 50 feet per minute to form a 17″ wide tissue sheet. The flow rate of the stock pulp slurry in the flow spreader was adjusted to give a target sheet basis weight of 12.7 gsm. The stock pulp slurry drained through the forming fabric, building an embryonic tissue sheet. The embryonic tissue sheet was transferred to a second fabric, a papermaking felt, before being further dewatered using a vacuum box to a consistency of between about 15 to about 25%. The tissue sheet was then transferred via a pressure roll to a steam heated Yankee dryer operating at a temperature of about 220° F. at a steam pressure of about 17 PSI. The dried tissue sheet was then transferred to a reel traveling at a speed about 30% slower than the Yankee dryer to provide a crepe ratio of about 1.3:1, thereby providing the blended tissue basesheet.
[0115] An aqueous creping composition was prepared containing about 0.317% by weight of polyvinyl alcohol (PVOH), available under the trade designation of Celvol 523 manufactured by Celanese, Dallas, Tex. (88% hydrolyzed and a viscosity of about 23 to about 27 cps. for a 4% solution at 20° C.); about 0.01% by weight of a PAE resin, available under the trade designation of Kymene 6500 from Hercules, Inc.; and, about 0.001% of a debonder/creping release agent, available under the trade designation of Resozol 2008, manufactured by Hercules, Inc. All weight percentages are based on dry pounds of the chemical being discussed. The creping composition was prepared by adding the specific amount of each chemical to 10 gallons of water and mixing well. PVOH was obtained as a 6% aqueous solution; Kymene 557 as a 12.5% aqueous solution; and, Resozol 2008 as a 7% solution in IPA/water. The creping composition was then applied to the Yankee dryer surface via a spray boom at a pressure of about 60 psi at a rate of about 0.25 g solids/m 2 of product. The finished blended tissue basesheet was then converted into a 2-ply tissue product with the dryer side of each ply facing outward.
Example 2
[0116] Example 2 demonstrates use of a conventional wet end debonder for preparing soft tissue products. The blended tissue basesheet used in this example was made in general accordance with Example 1. The Prosoft TQ-1003 was diluted to 1% solids with water prior to addition to the machine chest. The diluted Prosoft TQ-1003, a cationic oleylimidazoline debonder, commercially available from Hercules, Inc. was added to the machine chest. The machine chest was then allowed to stir for about 5 minutes prior to start of the tissue sheet formation. The amount of debonder to total tissue basesheet fiber on a dry weight basis was about 0.1%. The finished blended tissue basesheet was then converted into a 2-ply facial tissue product with the dryer side of each ply facing outward.
Example 3
[0117] Example 3 demonstrates use of a conventional wet end debonder for preparing soft tissue products. The blended tissue basesheet used in this example was made in general accordance with Example 1. The Prosoft TQ-1003 was diluted to about 1% solids with water prior to addition to the machine chest. The diluted Prosoft TQ-1003, a cationic oleylimidazoline debonder, commercially available from Hercules, Inc. was added to the machine chest. The machine chest was then allowed to stir for about 5 minutes prior to start of the tissue sheet formation. The amount of debonder to total tissue basesheet fiber on a dry weight basis was about 0.2%. The finished blended tissue basesheet was then converted into a 2-ply facial tissue product with the dryer side of each ply facing outward.
Example 4
[0118] Example 4 demonstrates the topical application of cationic synthetic co-polymer of the present invention to a wet, blended tissue basesheet prior to drying the blended tissue basesheet. The blended tissue basesheet used in this example was prepared in general accordance with Example 1. A 30% by weight aqueous dispersion of a cationic synthetic co-polymer of the present invention containing 80 mole % of n-butyl acrylate and 20 mole % of [2-(methacryloyloxy)ethyl]trimethyl ammonium chloride was diluted with water and sprayed onto the side of the tissue basesheet that is later brought into contact with the Yankee dryer. The blended tissue basesheet had a consistency, at this point, of between about 10% and about 20%. The aqueous dispersion was sprayed through two nozzles (commercially available under the designation 650017 from Spraying Systems Co., Wheaton, Ill.) at about 60 psi for a total addition rate of about 180 mL/min. Addition levels were controlled by adjusting the concentration of the diluted cationic synthetic co-polymer dispersion. No changes were required to the creping adhesive package and no felt plugging or other process issues were encountered with application of the cationic synthetic co-polymer. The amount of cationic synthetic co-polymer to total tissue basesheet fiber on a dry weight basis was about 0.1%. The finished blended tissue basesheet was then converted into a 2-ply facial tissue product with the dryer side of each ply facing outward.
Example 5
[0119] Example 5 demonstrates the topical application of cationic synthetic co-polymer of the present invention to a wet, blended tissue basesheet prior to drying the blended tissue basesheet. The blended tissue basesheet used in this example was prepared in general accordance with Example 1. A 30% by weight aqueous dispersion of a cationic synthetic co-polymer of the present invention containing 80 mole % of n-butyl acrylate and 20 mole % of [2-(methacryloyloxy)ethyl]trimethyl ammonium chloride was diluted with water and sprayed onto the side of the tissue basesheet that is later brought into contact with the Yankee dryer. The blended tissue basesheet had a consistency, at this point, of between about 10% and about 20%. The aqueous dispersion was sprayed through two nozzles (commercially available under the designation 650017 from Spraying Systems Co., Wheaton, Ill.) at about 60 psi for a total addition rate of about 180 mL/min. Addition levels were controlled by adjusting the concentration of the diluted cationic synthetic co-polymer dispersion. No changes were required to the creping adhesive package and no felt plugging or other process issues were encountered with application of the cationic synthetic co-polymer. The amount of cationic synthetic co-polymer to total sheet fiber on a dry weight basis was about 0.2%. The finished blended tissue basesheet was then converted into a 2-ply facial tissue product with the dryer side of each ply facing outward.
Example 6
[0120] Example 6 demonstrates the topical application of cationic synthetic co-polymer of the present invention to a wet, blended tissue basesheet prior to drying the blended tissue basesheet. The blended tissue basesheet used in this example was prepared in general accordance with Example 1. A 30% by weight aqueous dispersion of a cationic synthetic co-polymer of the present invention containing 80 mole % of n-butyl acrylate and 20 mole % of [2-(methacryloyloxy)ethyl]trimethyl ammonium chloride was diluted with water and sprayed onto the side of the tissue basesheet that is later brought into contact with the Yankee dryer. The blended tissue basesheet had a consistency, at this point, of between about 10% and about 20%. The aqueous dispersion was sprayed through two nozzles (commercially available under the designation 650017 from Spraying Systems Co., Wheaton, Ill.) at about 60 psi for a total addition rate of about 180 mL/min. Addition levels were controlled by adjusting the concentration of the diluted cationic synthetic co-polymer dispersion. No changes were required to the creping adhesive package and no felt plugging or other process issues were encountered with application of the cationic synthetic co-polymer. The amount of cationic synthetic co-polymer to total tissue basesheet fiber on a dry weight basis was about 0.4%. The finished blended tissue basesheet was then converted into a 2-ply facial tissue product with the dryer side of each ply facing outward.
[0121] Table 1 summarizes the data for Examples 1-6. FIG. 1 shows graphically the relationship between slough and tensile. Both Table 1 and FIG. 1 demonstrate the cationic synthetic co-polymers of the present invention simultaneously reducing slough and strength when applied topically to a wet, formed tissue sheet. Furthermore, the softness data shown in Table 3 and graphically in FIG. 2 shows that the tissue products treated with the cationic synthetic co-polymers of the present invention follow the same strength/softness technology curve as the standard cationic oleylimidazoline debonder. Hence, the tissue products that have lower slough at equivalent softness are obtained as shown in FIG. 3. Also given in a Table 1 are wet-out times showing that the tissue products of the present invention retain their absorbent properties.
TABLE 1 Amount % of Dry Example Additive Fiber Wet-out time, s Slough, mg GMT 1 None 0 16 1.8 717 2 Prosoft TQ-1003 0.1% 3 4.8 346 3 Prosoft TQ-1003 0.2% 3 7.6 232 4 Invention 0.1% 13 2.0 496 5 Invention 0.2% 18 1.3 433 6 Invention 0.4% 18 1.2 441
Example 7
[0122] Example 7 demonstrates the preparation of a layered tissue basesheet. About 70 pounds, oven dried basis, of eucalyptus hardwood kraft pulp fibers were dispersed in a pulper for about 30 minutes, forming an eucalyptus hardwood pulp kraft fiber slurry having a consistency of about 3%. The Eucalyptus pulp hardwood kraft fiber slurry was then transferred to two machine chests and diluted to a consistency of about 0.5 to about 1%. About 70 pounds, oven dry basis, of LL-19 northern softwood kraft pulp fibers were dispersed in a pulper for about 30 minutes, forming a northern softwood kraft pulp fiber slurry having a consistency of about 3%. A low level of refining was applied for about 12 minutes to the softwood kraft pulp fibers. After dispersing, the northern softwood kraft pulp fibers to form the slurry, the northern softwood kraft pulp fibers were passed to a machine chest and diluted to a consistency of between about 0.5 to about 1%.
[0123] Kymene 6500, a commercially available PAE wet strength resin from Hercules, Inc., was added to both the eucalyptus hardwood and northern softwood kraft pulp slurries in the machine chest at a rate of about 4 pounds of dry chemical per ton of dry fiber. The stock pulp fiber slurries were further diluted to approximately about 0.1 percent consistency prior to forming and deposited from a three layered headbox onto a fine forming fabric having a velocity of about 50 feet per minute to form a 17″ wide tissue sheet. The flow rates of the stock pulp fiber slurries into the flow spreader were adjusted to give a target sheet basis weight of about 12.7 gsm and a layer split of 35% Eucalyptus hardwood-kraft pulp fibers on both outer layers and 30% LL-19 northern softwood kraft pulp fibers in the center layer. The stock pulp fiber slurries were drained on the forming fabric, building a layered embryonic tissue sheet. The embryonic tissue sheet was transferred to a second fabric, a papermaking felt, before being further dewatered with a vacuum box to a consistency of between about 15 to about 25%. The embryonic tissue sheet was then transferred via a pressure roll to a steam heated Yankee dryer operating at a temperature of about 220° F. at a steam pressure of about 17 PSI. The dried tissue sheet was then transferred to a reel traveling at a speed about 30% slower than the Yankee dryer to provide a crepe ratio of about 1.3:1, thereby providing the layered tissue basesheet.
[0124] An aqueous creping composition was prepared containing about 0.317% by weight of polyvinyl alcohol (PVOH), available under the trade designation of Celvol 523 manufactured by Celanese (88% hydrolyzed with a viscosity of about 23 to about 27 cps. for a 4% solution at 20° C.); about 0.01% by weight of a PAE resin, available under the trade designation of Kymene 6500 from Hercules, Inc.; and, about 0.001% of a debonder/creping release agent, Resozol 2008, manufactured by Hercules, Inc. All weight percentages are based on dry pounds of the chemical being discussed. The creping composition was prepared by adding the specific amount of each chemical to 10 gallons of water and mixing well. PVOH was obtained as a 6% aqueous solution; Kymene 557 as a 12.5% aqueous solution; and, Resozol 2008 as a 7% solution in IPA/water. The creping composition was then applied to the Yankee dryer surface via a spray boom at a pressure of about 60 psi at a rate of about 0.25 g solids/m 2 of product. The finished layered basesheet was then converted into a 2-ply tissue product with the dryer side layer of each ply facing outward. See Table 4 showing physical properties of blended tissue basesheets. GMT was normalized to the basis weight of the untreated tissue sheet.
Example 8
[0125] Example 8 demonstrates use of a conventional wet end debonder for preparing soft tissue products. The layered tissue basesheet used in this example was made in general accordance with Example 7. The Prosoft TQ-1003 was diluted to about 1% solids with water prior to addition to the machine chest. The diluted Prosoft TQ-1003, a cationic oleylimidazoline debonder, commercially available from Hercules, Inc. was added to the machine chest containing the eucalyptus hardwood kraft pulp fiber slurry going to the layer that would come into contact with the dryer. The machine chest was then allowed to stir for about 5 minutes prior to start of the tissue sheet formation. The amount of debonder relative to total dried fiber of the tissue basesheet was about 0.025%. The finished layered tissue basesheets were then converted into a 2-ply facial tissue product with the dryer side layer of each ply facing outward.
Example 9
[0126] Example 9 demonstrates use of a conventional wet end debonder for preparing soft tissue products. The layered tissue basesheet used in this example was made in general accordance with Example 7. The Prosoft TQ-1003 was diluted to about 1% solids with water prior to addition to the machine chest. The diluted Prosoft TQ-1003, a cationic oleylimidazoline debonder, commercially available from Hercules, Inc. was added to the machine chest containing the eucalyptus hardwood kraft pulp fiber slurry going to the layer that would come into contact with the dryer. The machine chest was then allowed to stir for about 5 minutes prior to start of the tissue sheet formation. The amount of debonder to total tissue basesheet fiber on a dry weight basis was about 0.05%. The finished layered tissue basesheets were then converted into a 2-ply facial tissue product with the dryer side layer of each ply facing outward.
Example 10
[0127] Example 10 demonstrates the topical application of cationic synthetic co-polymer of the present invention to a wet, layered tissue basesheet prior to drying the layered tissue basesheet. The layered tissue basesheet used in this example was prepared in general accordance with Example 7. A 30% by weight aqueous dispersion of a cationic synthetic co-polymer of the present invention containing 80 mole % n-butyl acrylate and 20 mole % of [2-(methacryloyloxy)ethyl]trimethyl ammonium chloride was diluted with water and sprayed onto the side of the layered tissue basesheet that is later brought into contact with the Yankee dryer. The layered tissue basesheet had a consistency, at this point, of between about 10% and about 20%. The aqueous dispersion was sprayed through two nozzles (commercially available under the designation 650017 from Spraying Systems Co., Wheaton, Ill.) at about 60 psi for a total addition rate of about 180 mL/min. Addition levels were controlled by adjusting the concentration of the diluted cationic synthetic co-polymer dispersion. No changes were required to the creping adhesive package and no felt plugging or other process issues were encountered with application of the cationic synthetic co-polymer. The amount of cationic synthetic co-polymer to total tissue basesheet fiber on a dry weight basis was about 0.1%. The finished layered tissue basesheet was then converted into a 2-ply facial tissue product with the dryer side layer of each ply facing outward.
Example 11
[0128] Example 11 demonstrates the topical application of cationic synthetic co-polymer of the present invention to a wet, layered tissue basesheet prior to drying the layered tissue basesheet. The layered tissue basesheet used in this example was prepared in general accordance with Example 7. A 30% by weight aqueous dispersion of a cationic synthetic co-polymer of the present invention containing 80 mole % n-butyl acrylate and 20 mole % of [2-(methacryloyloxy)ethyl]trimethyl ammonium chloride was diluted with water and sprayed onto the side of the layered tissue basesheet that is later brought into contact with the Yankee dryer. The layered tissue basesheet had a consistency, at this point, of between about 10% and about 20%. The aqueous dispersion was sprayed through two nozzles (commercially available under the designation 650017 from Spraying Systems Co., Wheaton, Ill.) at about 60 psi for a total addition rate of about 180 mL/min. Addition levels were controlled by adjusting the concentration of the diluted cationic synthetic co-polymer dispersion. No changes were required to the creping adhesive package and no felt plugging or other process issues were encountered with application of the cationic synthetic co-polymer. The amount of cationic synthetic co-polymer to total tissue basesheet fiber on a dry weight basis was about 0.2%. The finished layered tissue basesheet was then converted into a 2-ply facial tissue product with the dryer side layer of each ply facing outward.
Example 12
[0129] Example 12 demonstrates the topical application of cationic synthetic co-polymer of the present invention to a wet, layered tissue basesheet prior to drying the layered tissue basesheet. The layered tissue basesheet used in this example was prepared in general accordance with Example 7. A 30% by weight aqueous dispersion of a cationic synthetic co-polymer of the present invention containing 80 mole % n-butyl acrylate and 20 mole % of [2-(methacryloyloxy)ethyl]trimethyl ammonium chloride was diluted with water and sprayed onto the side of the layered tissue basesheet that is later brought into contact with the Yankee dryer. The layered tissue basesheet had a consistency, at this point, of between about 10% and about 20%. The aqueous dispersion was sprayed through two nozzles (commercially available under the designation 650017 from Spraying Systems Co., Wheaton, Ill.) at about 60 psi for a total addition rate of about 180 mL/min. Addition levels were controlled by adjusting the concentration of the diluted cationic synthetic co-polymer dispersion. No changes were required to the creping adhesive package and no felt plugging or other process issues were encountered with application of the cationic synthetic co-polymer. The amount of cationic synthetic co-polymer to total tissue basesheet fiber on a dry weight basis was about 0.4%. The finished layered tissue basesheet was then converted into a 2-ply facial tissue product with the dryer side layer of each ply facing outward.
Example 13
[0130] Example 13 demonstrates the topical application of cationic synthetic co-polymer of the present invention to a wet, layered tissue basesheet prior to drying the layered tissue basesheet. The layered tissue basesheet used in this example was prepared in general accordance with Example 7. A 30% by weight aqueous dispersion of a cationic synthetic co-polymer of the present invention containing 80 mole % n-butyl acrylate and 20 mole % of [2-(methacryloyloxy)ethyl]trimethyl ammonium chloride was diluted with water and sprayed onto the side of the layered tissue basesheet that is later brought into contact with the Yankee dryer. The layered tissue basesheet had a consistency, at this point, of between about 10% and about 20%. The aqueous dispersion was sprayed through two nozzles (commercially available under the designation 650017 from Spraying Systems Co., Wheaton, Ill.) at about 60 psi for a total addition rate of about 180 mL/min. Addition levels were controlled by adjusting the concentration of the diluted cationic synthetic co-polymer dispersion. No changes were required to the creping adhesive package and no felt plugging or other process issues were encountered with application of the cationic synthetic co-polymer. The amount of cationic synthetic co-polymer to total tissue basesheet fiber on a dry weight basis was about 0.8%. The finished layered tissue basesheet was then converted into a 2-ply facial tissue product with the dryer side layer of each ply facing outward.
[0131] Table 2 summarizes the data for Examples 7-12. FIG. 1 shows graphically the relationship between slough and tensile. Both Table 2 and FIG. 1 demonstrate the cationic synthetic co-polymers of the present invention simultaneously reducing slough and strength when applied topically to a wet, formed tissue sheet. Furthermore, the softness data shown in Table 3 and graphically in FIG. 2 shows that the tissue products treated with the cationic synthetic co-polymers of the present invention follow the same strength/softness technology curve as the standard cationic oleylimidazoline debonder. Hence, tissue products that have lower slough at equivalent softness are obtained as shown in FIG. 3. Also given in Table 2 are wet-out times showing that the tissue products of the present invention retain their absorbent properties.
TABLE 2 Amount % of Total Sheet Dry Example Additive Fiber Wet-out time, s Slough, mg GMT 7 None 0 18 2.3 753 8 Prosoft TQ-1003 0.025% 6 6.3 594 9 Prosoft TQ-1003 0.05% 5 5.0 544 10 Invention 0.1% 18 2.2 627 11 Invention 0.2% 17 3.0 660 12 Invention 0.4% 18 2.3 652 13 Invention 0.8% 23 1.2 602
[0132] Softness testing was completed on Examples 1-13. The data is shown in table 3 and plots of tensile vs. softness are shown graphically in FIG. 2 for both blended and layered sheets. As seen in FIG. 2, the cationic synthetic co-polymers of the present invention provide equivalent softness to the standard debonders known in the art but also provide for lower slough products. This benefit is seen independent of the particular sheet structure employed. Hence, as FIG. 3 shows, it is possible to make equivalently soft tissue products that advantageously have lower lint and slough by employing the cationic synthetic co-polymers of the present invention. Again, this effect is independent of the particular tissue sheet structure that may be employed.
TABLE 3 Amount % of Exam- Total Sheet Dry Slough, ple Additive Fiber mg GMT Softness 1 None 0 1.8 717 7.7 2 Prosoft TQ-1003 0.1% 4.8 346 8.3 3 Prosoft TQ-1003 0.2% 7.6 232 8.6 4 Invention 0.1% 2.0 496 8.1 5 Invention 0.2% 1.3 433 8.2 6 Invention 0.4% 1.2 441 8.2 7 None 0 2.3 753 8.1 8 Prosoft TQ-1003 0.025% 6.3 594 8.5 9 Prosoft TQ-1003 0.05% 5.0 544 8.4 10 Invention 0.1% 2.2 627 8.4 11 Invention 0.2% 3.0 660 8.4 12 Invention 0.4% 2.3 652 8.3 13 Invention 0.8% 1.2 602 8.3
[0133] Examples 14-19 compare the use of an anionic hydrophobically modified acrylate polymer and the cationic synthetic co-polymers of the present invention in a 2-layer, 2-ply facial tissue product.
Example 14
[0134] Example 14 demonstrates the preparation of a 2-layered tissue basesheet. The 2-layered tissue basesheet was made in general accordance with the procedure outlined in Example 7 with the exception that a 2-layered tissue basesheet used in this example was formed consisting of a layer which contacted the surface of the Yankee dryer containing 65% of the total sheet weight of eucalyptus hardwood kraft pulp fibers and a felt (air side) layer containing 35% total sheet weight of LL-19 northern softwood kraft pulp fibers. The finished 2-layered tissue basesheet was then converted into a 2-layer, 2-ply facial tissue product with the dryer side layer of each ply facing outward.
Example 15
[0135] Example 15 demonstrates the topical application of cationic synthetic co-polymers of the present invention to a wet, 2-layered tissue basesheet prior to drying the 2-layered tissue basesheet. The 2-layered tissue basesheet used in this example was prepared in general accordance with Example 14. A 30% by weight aqueous dispersion of a cationic synthetic co-polymer containing 80 mole % n-butyl acrylate and 20 mole % of [2(methacryloyloxy)ethyl]trimethyl ammonium chloride was diluted with water and sprayed onto the side of the tissue basesheet that is later brought into contact with the Yankee dryer. The 2-layered tissue basesheet had a consistency, at this point, of between about 10% and about 20%. The aqueous dispersion was sprayed through two nozzles (commercially available under the designation 650017 from Spraying Systems Co., Wheaton, Ill.) at about 60 psi for a total addition rate of about 180 mL/min. Addition levels were controlled by adjusting the concentration of the diluted cationic synthetic co-polymer dispersion. No changes were required to the creping adhesive package and no felt plugging or other process issues were encountered with application of the cationic synthetic co-polymer. The amount of cationic synthetic co-polymer to total tissue basesheet fiber on a dry weight basis was about 0.5%. The finished 2-layered tissue basesheet was then converted into a 2-layer, 2-ply facial tissue product with the dryer side layer of each ply facing outward.
Example 16
[0136] Example 16 demonstrates the topical application of cationic synthetic co-polymers of the present invention to a wet, 2-layered tissue basesheet prior to drying the 2-layered tissue basesheet. The 2-layered tissue basesheet used in this example was prepared in general accordance with Example 14. A 30% by weight aqueous dispersion of a cationic synthetic co-polymer containing 80 mole % n-butyl acrylate and 20 mole % of [2(methacryloyloxy)ethyl]trimethyl ammonium chloride was diluted with water and sprayed onto the side of the tissue basesheet that is later brought into contact with the Yankee dryer. The 2-layered tissue basesheet had a consistency, at this point, of between about 10% and about 20%. The aqueous dispersion was sprayed through two nozzles (commercially available under the designation 650017 from Spraying Systems Co., Wheaton, Ill.) at about 60 psi for a total addition rate of about 180 mL/min. Addition levels were controlled by adjusting the concentration of the diluted cationic synthetic co-polymer dispersion. No changes were required to the creping adhesive package and no felt plugging or other process issues were encountered with application of the cationic synthetic co-polymer. The amount of cationic synthetic co-polymer to total tissue basesheet fiber on a dry weight basis was about 1.0%. The finished 2-layered tissue basesheet was then converted into a 2-layer, 2-ply facial tissue product with the dryer side layer of each ply facing outward.
Example 17
[0137] Example 17 demonstrates the topical application of a hydrophobically modified anionic co-polymer to a wet, 2-layered tissue basesheet prior to drying the 2-layered tissue basesheet. The 2-layered tissue basesheet used in this example was prepared in general accordance with Example 14. A 30% by weight aqueous dispersion of a hydrophobically modified anionic co-polymer containing 60 mole % acrylic acid; 24.5 mole % n-butylacrylate; 10.5 mole % 2-ethylhexylacrylate; and, 5 mole % AMPS wherein the AMPS was converted to the sodium salt was diluted with water and sprayed onto the side of the tissue basesheet that is later brought into contact with the Yankee dryer. The 2-layered tissue basesheet had a consistency, at this point, of between about 10% and about 20%. The aqueous dispersion was sprayed through two nozzles (commercially available under the designation 650017 from Spraying Systems Co., Wheaton, Ill.) at about 60 psi for a total addition rate of about 180 mL/min. Addition levels were controlled by adjusting the concentration of the diluted hydrophobically modified anionic co-polymer dispersion. Significant issues were encountered with crush and holes in the 2-layered tissue basesheet when using the anionic co-polymer. The amount of anionic co-polymer to total tissue basesheet fiber on a dry weight basis was about 0.15%. The finished 2-layered tissue basesheet was then converted into a 2-layer, 2-ply facial tissue product with the dryer side layer of each ply facing outward.
Example 18
[0138] Example 18 demonstrates the topical application of a hydrophobically modified anionic co-polymer to a wet, 2-layered tissue basesheet prior to drying the 2-layered tissue basesheet. The 2-layered tissue basesheet used in this example was prepared in general accordance with Example 14. A 30% by weight aqueous dispersion of a hydrophobically modified anionic co-polymer containing 60 mole % acrylic acid; 24.5 mole % n-butylacrylate; 10.5 mole % 2-ethylhexylacrylate; and, 5 mole % AMPS wherein the AMPS was converted to the sodium salt was diluted with water and sprayed onto the side of the tissue basesheet that is later brought into contact with the Yankee dryer. The 2-layered tissue basesheet had a consistency, at this point, of between about 10% and about 20%. The aqueous dispersion was sprayed through two nozzles (commercially available under the designation 650017 from Spraying Systems Co., Wheaton, Ill.) at about 60 psi for a total addition rate of about 180 mL/min. Addition levels were controlled by adjusting the concentration of the diluted hydrophobically modified anionic co-polymer dispersion. Significant issues were encountered with crush and holes in the 2-layered tissue basesheet when using the anionic co-polymer. The amount of anionic co-polymer to total tissue basesheet fiber on a dry weight basis was about 0.25%. The finished 2-layered tissue basesheet was then converted into a 2-layer, 2-ply facial tissue product with the dryer side layer of each ply facing outward.
Example 19
[0139] Example 19 demonstrates the topical application of a hydrophobically modified anionic co-polymer to a wet, 2-layered tissue basesheet prior to drying the 2-layered tissue basesheet. The 2-layered tissue basesheet used in this example was prepared in general accordance with Example 14. A 30% by weight aqueous dispersion of a hydrophobically modified anionic co-polymer containing 60 mole % acrylic acid; 24.5 mole % n-butylacrylate; 10.5 mole % 2-ethylhexylacrylate; and, 5 mole % AMPS wherein the AMPS was converted to the sodium salt was diluted with water and sprayed onto the side of the tissue basesheet that is later brought into contact with the Yankee dryer. The 2-layered tissue basesheet had a consistency, at this point, of between about 10% and about 20%. The aqueous dispersion was sprayed through two nozzles (commercially available under the designation 650017 from Spraying Systems Co., Wheaton, Ill.) at about 60 psi for a total addition rate of about 180 mL/min. Addition levels were controlled by adjusting the concentration of the diluted hydrophobically modified anionic co-polymer dispersion. Significant issues were encountered with crush and holes in the 2-layered tissue basesheet when using the anionic co-polymer. The amount of anionic polymer to total sheet fiber on a dry weight basis was about 0.50%. Significant issues with felt plugging and crush were encountered such that it was not possible to transfer the sheet to the Yankee dryer and no product could be obtained.
[0140] Furthermore, as Table 4 shows, the anionic co-polymer used in Examples 17-19 did not reduce slough and tensile as did the cationic synthetic co-polymer used in Examples 15-16. The tensile reduction seen in Example 18 is most likely due to the large number of holes in the sheet and not representative of a debonding effect. The 2-layered tissue basesheet treated in accordance with Example 19 could not be transferred to the Yankee dryer and wound due to the extremely poor quality of the tissue basesheet.
TABLE 4 Amount % of Dry Example Additive Fiber Wet-out time, s Slough, mg GMT 14 None 0 4 7.2 631 15 Cationic, invention 0.5% 12 5.6 610 16 Cationic, invention 1.0% 21 4.8 550 17 Anionic 0.15% 5 11.6 661 18 Anionic 0.25% 10 7.3 577 19 Anionic 0.50% Could not make sheet
Examples 20-28
[0141] Examples 20-28 demonstrate the applicability of the present invention using a number of different cationic synthetic co-polymers. Additionally, these examples demonstrate ability to use the cationic synthetic co-polymers of the present invention in conjunction with other cationic papermaking additives. In Examples 20-28, the layered tissue basesheets used were made in general accordance with Examples 7-13. A cationic glyoxylated polyacrylamide, available under the trade designation of Parez 631 NC manufactured by Bayer, Inc., Suffolk, Va., was added to the LL-19 softwood kraft pulp fibers in the machine chest at a level of about 5 pounds of dry solids of the chemical per ton of dry LL-19 softwood kraft pulp fibers. A commercially available cationic polyamide epichlorohydrin wet strength resin, Kymene 6500 available from Hercules, Inc. was added to both the northern softwood kraft pulp fibers and the eucalyptus hardwood kraft pulp fibers in the machine chest at a level of about 4 pounds of dry solids of the chemical per ton of dry fiber. The cationic synthetic co-polymers were applied as aqueous dispersions via spraying through two nozzles (commercially available under the designation 650017 from Spraying Systems Co., Wheaton, Ill.) at about 60 psi for a total addition rate of about 180 mL/min. Addition levels were controlled by adjusting the concentration of the diluted cationic synthetic co-polymer dispersions. In each example, the layered tissue basesheets were converted into 2-ply facial tissue products with the dryer side layer of each ply facing outward as with all previous examples.
[0142] For Examples 21-23, a standard cationic oleylimidazoline debonder, available under the designation of Prosoft TQ-1003 manufactured by Hercules, Inc., was added to the northern softwood kraft pulp fibers going to the layer of the tissue basesheet in each example that is later brought into contact with the Yankee dryer. The debonder was added to the machine chest as about 1% aqueous emulsion and allowed to stir for about 5 minutes prior to forming the tissue basesheet for each example.
TABLE 5 Chemical Composition I 89.9 mole % Ethyl Acrylate, 0.1 mole % Methyl Methacrylate, 10 mole % [2-(methacryloyloxy)ethyl]trimethyl ammonium chloride II 89.9 mole % Ethyl Acrylate, 0.1 mole % Methyl Methacrylate, 10 mole % 2-[(acryloyloxy)ethyl]trimethyl ammonium chloride III 74.9 mole % Ethyl Acrylate, 0.1 mole % Methyl Methacrylate, 25 mole % 2-[(acryloyloxy)ethyl]trimethyl ammonium chloride IV 80 mole % Butyl Acrylate, 20% mole % [2- (methacryloyloxy)ethyl]trimethyl ammonium methosulfate
[0143] Specific chemical compositions of the cationic synthetic co-polymers used in Examples 24-27 are shown in Table 5. The chemical compositions I-III were prepared via an emulsion polymerization process using a non-ionic surfactant. The chemical compositions I-III were delivered as between about 25% to about 35% solids aqueous emulsions. The chemical composition IV was prepared via a solvent displacement process and was delivered as a 30% solids aqueous dispersion containing no surfactants. The physical test results are shown in Table 6. Example 28 is a control sample used to determine impact of water spraying alone on the tissue basesheet. As Example 28 demonstrates, the effects seen in the tissue basesheet, and ultimately the facial tissue products made from the tissue basesheets, wherein the cationic synthetic co-polymers of the present invention was used, are related to application of the cationic synthetic co-polymer and not a function of the water.
TABLE 6 Amount % of Total Sheet Dry Wet-out Example Additive Fiber time, s Slough, mg GMT Softness 20 None 0 6 3.5 1160 6.9 21 Prosoft TQ-1003 0.05% 5 3.9 1026 7.2 22 Prosoft TQ-1003 0.15% 3 7.8 747 7.8 23 Prosoft TQ-1003 0.20% 3 6.8 635 8.0 24 III 0.40% 10 2.0 1124 7.0 25 II 0.40% 21 2.3 842 7.6 26 I 0.40% 22 2.1 733 7.6 27 IV 0.20% 23 2.3 772 7.4 28 Water 7 4.1 1052 7.0
[0144] The data is shown graphically in FIGS. 4 and 5. As with the previous examples, the cationic synthetic co-polymers of the present invention show significantly less slough increase with decreased tensile than the standard oleylimidazoline debonder. FIG. 5 shows that the facial tissue products made using the cationic synthetic co-polymers of the present invention display lower slough at a given level of softness.
Examples 29-34
[0145] In Examples 29-34, all examples used a layered basesheet made in general accordance with Examples 7-13 with the exception that no refining was done to the eucalyptus hardwood kraft pulp fibers. A cationic glyoxylated polyacrylamide, available under the designation of Parez 631 NC manufactured by Bayer, Inc., was added to the LL-19 softwood kraft pulp fibers in the machine chest at a level of about 10 pounds of dry solids of the chemical per ton of the dry LL-19 softwood kraft pulp fibers. A cationic polyamide epichlorohydrin wet strength resin, available under the designation of Kymene 6500 manufactured by Hercules, Inc. was added to both the northern softwood kraft pulp fibers and the eucalyptus hardwood kraft pulp fibers in the machine chest at a level of about 4 pounds of dry solids of the chemical per ton of dry kraft pulp fiber. The cationic acrylate polymers and debonders were added to the Eucalyptus hardwood kraft fibers in the machine chest going to the layer of the tissue basesheets that is later brought into contact with the Yankee dryer. Specific chemical compositions of the cationic synthetic co-polymers used in Examples 31-34 are given in Table 7.
TABLE 7 Chemical Composition V 95 mole % methyl acrylate, 5 mole % [2- (acryloyloxy)ethyl]trimethyl ammonium chloride VI 80 mole % N-butyl acrylate, 20 mole % [2- (methacryloyloxy)ethyl]trimethyl ammonium chloride
[0146] The slough, tensile, and softness results are shown in Table 8 and graphically presented in FIGS. 6 and 7. Relative to the control debonders, the cationic synthetic copolymers of the present invention show significantly less slough formation. As with the other examples, tissue basesheets made using the cationic synthetic co-polymers of the present invention show less slough generation at a given tensile than the standard debonders.
TABLE 8 Weight % of Dry Fiber in Dryer Wet-out Example Additive Layer time, s Slough, mg GMT Softness 29 Prosoft TQ-1003 0.10% 2.9 7.6 605 8.2 30 Prosoft TQ-1003 0.15% 2.8 8.1 495 8.3 31 V 0.25% 22 2.2 629 8.0 32 V 0.50% 50.6 4.1 548 8.1 33 VI 0.25% 38.4 5.1 581 8.1 34 VI 0.50% 103.9 5.7 459 8.3
[0147] The results show that it is possible to reduce slough at equivalent or lower GMT by applying the cationic synthetic co-polymers of the present invention to a fiber slurry prior to formation of the tissue sheet.
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The present invention is a soft tissue sheet having reduced lint and slough. The tissue sheet comprises papermaking fibers and a synthetic co-copolymer. The synthetic co-polymer has the general structure:
wherein R 1 , R 2 , R 3 are independently selected from a group consisting of: H; C 1-4 alkyl radicals; and, mixtures thereof; R 4 is selected from a group consisting of C 1 -C 8 alkyl radicals and mixtures thereof; Z 1 is a bridging radical attaching the R 4 functionality to the polymer backbone; and, Q 1 is a functional group containing at least a cationic quaternary ammonium radical. w, x, y≧ 1 and the mole ratio of x to (x+y) is about 0.5 or greater.
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FIELD OF THE INVENTION
The present invention relates to fluorine-containing copolymers.
The present invention relates also to a carrier for developing electrostatic images which constitute, along with a toner, an electrostatic image developer for use with an electronic photographic copying machine (hereinafter referred to simply as "carrier").
BACKGROUND OF THE INVENTION
Known carriers include those coated with a copolymer comprising vinylidene fluoride (hereinafter generally referred to as "VdF") and tetrafluoroethylene (hereinafter generally referred to as "TFE") (Japanese Unexamined Patent Publication No.58-20,875).
The carrier coated with the VdF/TFE copolymer has excellent properties such as larger electrostatic charge capacity than the silicone-coated carrier and higher electrostatic charge stability due to lower adhesion of the toner to the carrier. However, when the carrier is used in combination with a toner which aims to give improved properties indicated as above to the silicone-coated carrier, the resultant electrostatic image developer exhibits a serious defect that images cannot be transferred because of too large an electrostatic charge capacity. When a toner capable of being used both for the silicone-coated carrier and the VdF/TFE copolymer coated carrier is to be developed without imparing the excellent properties of the carrier as stated above, the toner would be very costly and economically disadvantageous.
Also known are carriers coated with a VdF/TFE/vinyl butyrate copolymer (Japanese Unexamined Patent Publication No.54-110,839). This type of carrier has a moderate and suitable electrostatic charge capacity. However, the coating layer formed of the copolymer is soft and easily damaged when stirred with the particulate toner and low in durability.
SUMMARY OF THE INVENTION
It is the primary object of the present invention to provide a new polymer capable of forming a coating on the carrier core with improved properties.
It is another object of the invention to provide a carrier which can be used even in combination with a toner which is developed for the silicone-coated carrier.
It is a further object of the invention to provide a carrier comprising a core and a coating on the core, the coating having a suitable range of electrostatic charge capacity.
Other objects and features of the invention will become apparent from the following description.
We conducted extensive research to overcome the foregoing problems of the conventional techniques and found that new copolymers comprising 3 comonomers exhibit outstanding properties when used for coating the carrier core.
The present invention provides a fluorine-containing copolymer comprising:
a) 50 to 85 mole % of a structural unit represented by the formula
--CH.sub.2 13 CF.sub.2 --
(b) 5 to 40 mole % of a structural unit represented by the formula
--CF.sub.2 --CFX--
wherein X is H or F, and
(c) 3 to 18 mole % of a structural unit represented by the formula ##STR2##
The present invention also provides a carrier for developing electrostatic image, the carrier comprising a core and coating on the core, the coating being formed from a copolymer comprising:
(a) 50 to 85 mole % of a structural unit represented by the formula
--CH.sub.2 --CF.sub.2 --
(b) 5 to 40 mole % of a structural unit represented by the formula
--CF.sub.2 --CFX--
wherein X is H or F, and
(c) 3 to 18 mole % of a structural unit represented by the formula ##STR3##
DETAILED DESCRIPTION OF THE INVENTION
The copolymer and the carrier of the invention will be described below in greater detail.
The copolymer useful as coating materials for the carrier core in the invention comprises about 50 to about 85 mole % of the structural unit (a), about 5 to about 40 mole % of the structural unit (b) and about 3 to about 18 mole % of the structural unit (c). The copolymer containing less than 50 mole % or more than 85 mole % of the structural unit (a) results in a low solvent solubility when used as a solution for coating the carrier core. Over 40 mole % of the structural unit (b) used gives a copolymer which shows a low solvent solubility whereas a copolymer is difficult to obtain when the structural unit (b) is less than 5 mole %. When the amount of the structural unit (c) exceeds 15 mole %, a soft copolymer is formed which is low in durability as the coating of the carrier core whereas use of the structural unit (c) in an amount less than 3 mole % gives too high an electrostatic charge capacity to the carrier. A more preferred composition of the copolymer comprises about 55 to about 80 mole % of the structural unit (a), about 15 to about 35 mole % of the structural unit (b) and about 5 to about 15 mole % of the structural unit (c).
The copolymer of the invention may contain a copolymerizable monomer as a third component in addition to the foregoing monomer components or structural units in such an amount that the addition will not impair the properties of the copolymer, for example in an amount of up to about 30% by weight of the copolymer. Examples of such monomers are: ##STR4##
The copolymers of the invention are random copolymers and usually has an intrinsic viscosity (η) of about 0.2 to about 2.0, preferably about 0.35 to about 1.0, as determined at 35° C. using methyl ethyl ketone (MEK) as a solvent.
The copolymers of the invention are prepared by usual radical polymerization processes such as suspension polymerization employing isobutyryl peroxide, diisopropyl peroxydicarbonate, (CF 3 COO) 2 O or the like as the initiator and a mixture of water and a chlorofluorohydrocarbon such as 1,1,2-trichloro-1,2,2-trifluoroethane, 1,2-dichloro-1,1,2,2-tetrafluoroethane or the like as the medium; emulsion polymerization employing ammonium persulfate, potassium persulfate, hydrogen peroxide, a redox agent comprising a mixture of at least one of these peroxides, a reducing agent such as ferrous sulfate and a stabilizer such as e-ascorbic acid or the like as the initiator, water as the medium and C 7 F 15 COONH 4 or the like as the emulsifies, etc. In the case of suspension polymerization, the weight ratio of water/chlorofluorohydrocarbon is preferably about 3/1 to about 1/2 and ethyl acetate, acetone or the like may be added for adjusting the polymerization degree. In the case of emulsion polymerization, the amount of emulsifier is preferably about 0.01% based on the weight of water. The polymerization temperature in any polymerization method is usually 0° to 150° C., preferably about 15° to about 80° C. and the polymerization time is up to about 48 hours. The polymerization pressure in any polymerization method is about 2 to about 100 kg/cm 2 , preferably about 5 to about 10 kg/cm 2 .
The coating composition can be prepared by dissolving the copolymer of the invention into an organic solvent. A wide variety of organic solvents can be used which include acetone, methyl ethyl ketone, methyl propyl ketone, methyl isopropyl ketone, methyl isobutyl ketone and like ketone solvents; ethyl acetate, methyl acetate, n-butyl acetate and like acetic acid ester solvents; tetrahydrofuran, dioxane and like cyclic ethers; dimethylformamide, dimethylacetamide and like amides, etc. These solvents can be used singly or as a mixture of at least two kinds. The solvent may contain a diluent medium in an amount up to 50% of the solvent. Examples of diluent media are toluene, xylene and like aromatic hydrocarbons; tetrachloroethylene, trichloroethylene, methylene chloride and like halogenated hydrocarbons; methyl alcohol, ethyl alcohol, butyl alcohol, isopropyl alcohol and like alcohols; 1,1,2-trifluorotrichloroethane, 1,2-difluorotetrachloroethane, hexafluoromethaxylene, 1,1,1,2,2-pentafluorodichloropropane and like fluorine-containing solvents, etc. A preferred solvent has a boiling point of about 60° to about 140° C. in view of the evaporation rate and the like. The coating composition may contain an additive or additives in an amount of up to 30% based on the weight of the copolymer of the invention. Examples of additives are vinylidene fluoride polymer, vinylidene fluoride-tetrafluoroethylene copolymer, silicone, (meth)acrylic polymer, silica, carbon black, electric charge controlling agent, surfactant, lubricant, etc.
The carrier core can be coated by the conventional method or a similar one. More specifically, the surface of the carrier core is coated by the desired conventional method with a solution of the terpolymer of the invention in a solvent.
The materials useful for the formation of the carrier core in the invention are not specifically limited and can be any of conventional materials such as iron, cobalt, nickel, ferrite, magnetite and like ferronmagnetic metals and alloys; Mn-Cu-Al, Mn-Cu-Sn and like Heusler's alloys; and CrO 2 and like metallic oxides.
The carrier core is usually about 30 to about 1000 μm, preferably about 50 to about 500 μm in diameter.
The coating on the carrier core is controlled such that it amounts to usually about 0.1 to about 3%, preferably about 0.5 to about 2% based on the weight of the core. After the formation of coating on the core, the carrier may be heated to improve the properties of the coating.
The carrier according to the invention is used in combination with a conventional toner in developing electrostatic images. The toner is produced by dispersing a coloring agent in a binder resin. Examples of the binder resin are polystyrene, p-chlorostyrene, α-methylstyrene and like polystyrenes; poly(methylacrylate), poly(ethylacrylate), poly(n-propylacrylate), poly(butylacrylate), poly(laurylacrylate), poly(2-ethylhexylacrylate), poly(methylmethacrylate), poly(ethylmethacrylate), poly(n-butylmethacrylate), poly(laurylmethacrylate), poly(2-ethylhexylmethacrylate) and like polymers of α-methylene monocarboxylic acid esters; polyacrylonitrile, polymethacrylonitrile and like polyvinylnitrile; poly(2-vinylpyridine), poly(4-vinylpyridine) and like polyvinylpyridines; poly(vinylmethylether), poly(vinylisobutylether) and like polyvinylethers; polyvinylmethylketone, polyvinylethylketone, polymethylisopropenylketone and like polyvinylketones; polyethylene, polypropylene, polyisopropylene, polybutadiene and like polymers of unsaturated hydrocarbons, and halogenated derivatives thereof; homopolymers and copolymers of halogenated unsaturated hydrocarbons; mixtures of at least two polymers indicated above, etc. The binder resin may contain rosin-modified phenol-formaldehyde resin, oil-modified epoxy resin, polyester, polyurethane, polyimide, cellulosic resin, polyester and like resins.
Examples of the coloring agents used in the toner are carbon black, nigrosine, aniline blue, chrome yellow, ultramarine blue, methylene blue, phthalocyanine blue, etc.
The toner may contain a known additive or additives such as wax, silica, zinc stearate, etc.
The carrier of the invention and the toner is uniformly mixed in an ratio of about 0.3 to about 20 parts by weight of the latter per 100 parts by weight of the former. The mixture is used for developing electrostatic images in magnetic brushing process, cascade process, etc.
The coating formed from the copolymer of the invention on the carrier core has high strength and good adhesion to the core. Thus, the carrier is excellent in durability and has a high electrostatic charge capacity.
The carrier having a coating formed from the copolymer of the invention is highly compatible with the toner produced especially for use with the silicone-coated carrier without impairing the excellent properties such as electrostatic charge stability, etc. of the carrier coated with fluorine- containing copolymer.
Since the copolymer according to the invention is highly soluble in organic solvents and has good adhesion to a substrate and high film strength, it is useful for materials for producing weathering-resistant coating compositions, cladding for optical fibers, durable films, etc.
EXAMPLES
Given below are examples and comparison examples to clarify the features of the present invention.
EXAMPLE 1
A 1-liter autoclave was charged with 230 cc of water and 386 g of 1,2-dichloro-1,1,2,2-tetrafluoroethane. The autoclave was subjected to nitrogen replacement and was further charged with 25 g of vinylidene fluoride (VdF), 6 g of tetrafluoroethylene (TFE) and 1.5 g of vinyl pivalate (VPv). The contents in the autoclave were heated to 40° C. and sufficiently stirred and 1 g of diisopropylperoxydicarbonate was added thereto to initiate a polymerization. Throughout the polymerization, a mixture of VdF, TFE and VPv was fed to the reaction system so that the polymerization was conducted in a ratio of 72:18:10 (mole %) for 12 hours. The copolymer thus obtained was collected and dried under reduced pressure at 100° C., giving 40 g of a copolymer. The elementary analysis of the copolymer gave a result of C:F:H=37.7:55.9:2.87 (% by weight). In the 19 F-NMR spectrum of the copolymer using trifluoroacetic acid as the external reference and the numbers on the shift scale upfield from the reference being designated positive, there appeared the resonance of CF 2 of VdF between +15 and 17 ppm, the resonance of CF 2 between +42 and +46 ppm and between +47 to +49 ppm, and the resonance of CF 2 of bond (main chain) of VdF and TFE between +33 to +39 ppm. In the 1 H-NMR spectrum of the copolymer using tetramethylsilane as the inner reference and the numbers on the shift scale upfield from the reference being designated positive, there appeared the resonance of CH 3 of VPv at 1.2 ppm, the resonance of CH of VPv between +5 to +6 ppm, and the resonance of CH2 of VdF and VPv near at +3 ppm. A calculation based on the results of elementary analysis and the comparison of the peak strengths obtained in NMR spectra indicated the mole ratio of the components in the copolymer was VdF/TFE/VPv=73/19/8.
The copolymer was found to have a melting temperature (Tm) of 120° C., a crystalization temperature of 99° C. and an intrinsic viscosity (η) of 0.45 (at 35° C. using MEK).
EXAMPLE 2
Using 13 g of TFE, 21 g of VdF and 1.5 g of VPv and maintaining the mole ratio of additional monomers at VdF/TFE/VPv=60/30/10 during the reaction, the procedure of Example 1 was followed for 5.5 hours to obtain 45 g of a copolymer.
The copolymer was found to be composed of VdF/TFE/VPv=64/28/8 (molar ratio) from the calculation based on the elementary analysis and NMR spectra and have an intrinsic viscosity (η) of 0.57 (at 35° C. using MEK).
EXAMPLE 3
Using 16 g of TFE, 20 g of VdF and 1.5 g of VPv and maintaining the mole ratio of additional monomers at VdF/TFE/VPv=53/32/15 during the reaction, the procedure of Example 1 was followed for 9 hours to obtain 52 g of a copolymer.
The copolymer was found to be composed of VdF/TFE/VPv=57/30/13 (molar ratio) from the calculation based on the elementary analysis and NMR spectra and have an intrinsic viscosity (η) of 0.52 (at 35° C. using MEK).
EXAMPLE 4
Using 6 g of trifluoroethylene (TrFE), 26 g of VdF and 1 g of VPv and maintaining the mole ratio of additional monomers at VdF/TFE/VPv=72/18/10 during the reaction, the reaction procedure of Example 1 was followed for 16 hours to obtain 33 g of a copolymer.
The copolymer was found to be composed of VdF/TFE/VPv=72/18/10 (molar ratio) from the calculation based on the elementary analysis and NMR spectra and have an intrinsic viscosity (η) of 0.38 (at 35° C. using MEK).
EXAMPLE 5
A 3 parts by weight quantity of the copolymer obtained in Example 1 was dissolved in a mixture of 68 parts by weight of acetone and 29 parts by weight of MEK to prepare a coating solution.
A 200 g quantity of spherical iron particles (trademark "DSPR141", product of Dowa Iron Powder Co., Ltd., Japan: 100 μm in average particle size) serving as the carrier core material was coated with the coating solution using a fluidized bed apparatus at a temperature of 70° C. to form a carrier having a coating on the core in an amount of 0.5% by weight of the core.
A 3 parts by weight of a toner (commercially available and intended for use in a copying machine "FT 4800", product of Ricoh Co., Ltd. was added to 97 parts by weight of the carrier as obtained above.
A 7 g quantity of the combined toner and carrier was stirred in a glass container (50 ml) for 30 minutes at 300 rpm to prepare a uniform mixture as an electrostatic image developer.
A 200 mg quantity of the mixture was taken to evaluate the electrostatic charge of the toner by the blow-off method. The value was +2.8 μC/g.
EXAMPLE 6
The copolymer obtained in Example 2 was processed in the same manner as in Example 5 to prepare a mixture of carrier and toner.
The electrostatic charge on the toner was 3.4 μC/g.
EXAMPLE 7
The polymer produced in Example 3 was processed in the same manner as in Example 5 to prepare a mixture of carrier and toner.
The electrostatic charge on the toner was +3.30 μC/g.
EXAMPLE 8
The copolymer obtained in Example 4 was processed in the same manner as in Example 5 to form a mixture of carrier and toner.
The electrostatic charge on the toner was +3.65 μC/g.
COMPARISON EXAMPLE 1
A VdF/TFE copolymer (trademark "Neoflon VdFVT100", product of Daikin Industries, Ltd.) was processed in the same manner as in Example 5 to prepare a carrier and further combined with the toner to prepare a mixture of carrier and toner.
The electrostatic charge on the toner was 16.01 μC/g.
COMPARISON EXAMPLE 2
A copolymer prepared from 70 parts of VdF, 20 parts of TFE and 10 parts of vinyl butyrate was processed in the same manner as in Example 5 to prepare a carrier and further combined with the toner to prepare a mixture.
The electrostatic charge on the toner was 1.73 μC/g.
TEST EXAMPLE 1
A cluster of toner particles 9 μm in mean particle size was prepared by mixing together with use of a ball mill 100 parts by weight of a styrene/methyl methacrylate/n-butyl methacrylate copolymer (=50/20/30), 10 parts by weight of carbon black (trademark "Regal 660R", product of Cabot Co., Ltd.), 3.5 parts by weight of a low-molecular-weight polypropylene (trademark "Viscol 660P", product of Sanyo Chemical Industry, Ltd.) and 2 parts by weight of nigrosine dye (trademark "Oil Black SO", Orient Chemical Co, Ltd.), kneading and grinding the mixture and classifying the particles.
Two parts by weight of the toner was mixed with 100 parts by weight of each carrier obtained in Examples 5 to 8 and Comparison Examples 1 and 2, giving developers for electronic photographic copying machines.
Using the developers thus prepared, a copying operation was continuously carried out to produce photocopies on the modified version of electrophotographic copying machine "U-Bix 3000" (trademark, product of Konishiroku Photo Industry Co., Ltd.) incorporating a negative electrostatic dual-layer organic photoconductive photosensitive member containing an anthoanthrone-type pigment as a charge-generation material and a carbazole derivative as a charge-transported material. Up to 50,000 photocopies can be continuously produced on which images with no fogging were formed using the developer containing the carriers of Examples 5 to 8. When the photographic density of the original was 1.3 the highest density of the copied image after 50,000 photocopies was more than 1.3.
When the developer incorporating the carrier of Comparison Example 1 was used, the highest density at the start of the copying operation was only 0.6.
The copying operation using the developer with the carrier of Comparison Example 2 initiated fogging on production of only 15 copies.
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This invention provides a fluorine-containing copolymer comprising:
(a) 50 to 85 mole % of a structural unit represented by the formula
--CH.sub.2 --CF.sub.2--,
(b) 5 to 40 mole % of a structural unit represented by the formula
--CF.sub.2 --CFX--
wherein X is H or F, and
(c) 3 to 18 mole % of a structural unit represented by the formula ##STR1##
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The invention relates to a hanger and hanger mount assembly for a chest drainage unit and relates more specifically to a hanger and hanger mount assembly for a chest drainage unit that is adjustable to allow the chest drainage unit to hang in a vertical direction even when the chest drainage unit is displaced from its free hanging vertical position.
2. Description of Related Art
Chest drainage units (CDUs) are used to collect and measure fluids and other material from a patient's chest during and after surgery and as a result of injury to the patient's chest. It is important to accurately measure the amount of fluids and other material collected in the CDU from the patient in order to adequately monitor the patient's condition and be alerted to problems that may be developing.
CDUs typically have indicia to visually indicate the amount of fluids and other material removed from the patient's chest during use. These indicia usually takes the form of markings on the outside of the CDU corresponding to certain volumes of fluid and other material collected inside the CDU.
To determine the volume of fluids or other material collected, the series of indicia are usually visually aligned with the top surface of fluids and other material collected in the CDU. The specific indicia aligned with this top surface corresponds to the volume of such material collected in the CDU.
In the system of determining the volume of material collected in a CDU described above, the indicia correspond to volumes of material in the CDU when the CDU is in its most vertical position. Any deviation of the CDU from its most vertical position causes a misalignment of the top surface of the material collected and the correct indicia corresponding to the actual volume. In fact, when the CDU is moved sufficiently from its most vertical position, the top surface of the material collected will be aligned with an indicia corresponding to other than the correct volume of material collected so that an incorrect reading of the amount of material collected is obtained.
During use, many chest drainage units (CDUs) are suspended by a pair of hangers from a rail that is part of the bedframe. Referring to FIGS. 1 and 2, the CDU is generally labeled 2. The CDU 2 has a top 4, a front 6, a back 8 and a pair of opposed sides 10. Top sides 12 are formed where top 4 intersects opposed side 10.
A rigid hanger 14 connects CDU 2 to a bedframe piece 16 or similar support. Usually, a pair of hangers 14 connect CDU 2 to bedframe piece 16 from opposite ends of the top 4 of CDU 2 at a mount 18 as shown in FIG. 2. FIG. 1 shows only one hanger 14, the other hanger 14 being a mirror image of the hanger 14 shown.
Hanger 14 has a curved end 20 that extends around bedframe piece 16 and a pivot end 22 that is pivotally attached to the CDU 2 at mount 18. Mount 18 is attached to the top 4 of CDU 2 between CDU front 6 and CDU back 8 so that when curved end 20 is placed over bedframe piece 16 and CDU 2 is allowed to freely hang, pivot end 22 is directly above the horizontal line extending through the center of gravity of the CDU 2 that intersects the opposed sides 10 of CDU 2 when CDU front 6 and CDU back 8 are both vertical. The point of intersection of the horizontal line extending through the center of gravity of the CDU 2 and the opposed sides 10 of CDU 2 when CDU front 6 and CDU back 8 are both vertical will be referred to throughout this description as intersection point 24. In this way, when the hangers 14 are attached to the bedframe piece 16 and the CDU 2 is allowed to hang freely, CDU 2 hangs from the hanger mount 18 in its most vertical position.
Indicia 26 are typically located on the CDU front 6. This allows the volume of material collected from the patient to be visually determined as described above.
As stated above, the system for hanging CDUs from a bedside anticipates that the CDU will be allowed to freely hang in its most vertical position from a hanger attached to a rail that is part of a bedframe. In actual use several factors occur that prevent the CDU from hanging in its most vertical position.
One of the most common of these situations is shown in FIG. 3. In FIG. 3, the CDU 2 is moved away from its freely hanging vertical position by contact with an object A such as a part of the bedframe. In this common situation, the connection of mount 18 and the pivot end 22 of hanger 14 is constrained to move on an arc B defined by the rotation of hanger 14 around bedframe piece 16 in response to the contact with the object A.
In most CDUs, the length of hanger 14 is relatively short, typically about 4 inches. Because of this relatively short distance, if the object A moves the CDU 2 away from its most vertical position by more than the length of hanger 14, despite the movement of mount 18 and pivot end 22 on arc B, CDU 2 will necessarily be tilted at an angle from vertical. As previously mentioned, any deviation of CDU 2 from vertical results in a misalignment of the indicia 26 with the top of the material collected in CDU 2 so that an accurate reading of the collected amount is difficult or impossible to obtain.
Further, as shown in FIG. 4, even if CDU 2 is displaced away from its most vertical position by less than the length of hanger 14, CDU 2 may still be tilted away from a vertical position by contact between CDU 2 and the contacting object A. Contact between object A and CDU 2 will cause CDU 2 to move horizontally away from its free hanging position. As CDU 2 begins to move horizontally, the contact point between mount 18 and pivot end 22 is constrained to move along arc B. However, this path along arc B causes the center of gravity of CDU 2 to be raised, thus increasing the potential energy of the CDU/hanger system.
Further, because the CDU 2 pivots around the connection between mount 18 and pivot end 22, CDU 2 is a physical pendulum pivoting around the connecting point between mount 18 and pivot end 22. Contact between object A and CDU 2 may also cause this physical pendulum to rotate out of its vertical or lowest energy position to a non-vertical and higher energy position.
Of course, CDU 2 will try to minimize its potential energy by mount 18 and pivot end 22 moving along arc B and also by CDU 2 rotating around the connection between mount 18 and pivot end 22 to minimize the potential energy of the physical pendulum formed by CDU 2. However, frictional contact between CDU 2 and the contacting object A prevents CDU 2 from sliding along the contacting object A as mount 18 and pivot end 22 move along arc B and CDU 2 rotates around the connection point between mount 18 and pivot end 22 to the point of lowest potential energy. Consequently, even slight movement of CDU 2 from its free hanging vertical position may cause CDU 2 to not be vertical thereby making it difficult or impossible to accurately ascertain the volume of material collected in the CDU.
In view of the foregoing, it is desirable to have a hanger mount that allows the alignment of the indicia on the CDU with the top surface of the material collected in the CDU to accurately represent the volume of material collected even if the CDU is displaced from its free hanging vertical position.
SUMMARY OF THE INVENTION
A CDU hanger mount assembly and hanger is provided. The mount assembly and hanger allows the CDU to be supported by an object for supporting the CDU while the connecting point between the hanger mount and the pivot end of the hanger may be selectively moved from a point midway between the front and back of the CDU top toward the back of the CDU. This allows the CDU to be less displaced from the vertical upon displacing contact with an object such as a bedframe piece. The hanger and hanger mount assembly allows the alignment of the indicia on the CDU with the top surface of the material collected in the CDU to be a more accurate representation of the actual volume of material collected in the CDU. The mount assembly and hanger may also be used with medical devices other than CDUs.
It is therefore an object of the invention to provide a hanger and hanger mount assembly that is adjustable to allow the alignment of the indicia on the CDU with the top surface of the material collected in the CDU to accurately represent the volume of material collected even if the CDU is displaced from its free hanging vertical position.
It is a further object of the invention to provide a hanger and hanger mount assembly that is easy to use.
It is a further object of the invention to provide a hanger and hanger mount assembly that is easy to adjust.
It is another object of the invention to provide an adjustable hanger and hanger mount assembly that is easy and inexpensive to manufacture.
These and other objects of the invention will be clear from the description contained herein and more particularly with reference to the following detailed description of the invention and the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a side elevational view of a prior art chest drainage unit (CDU).
FIG. 2 is a perspective view of the CDU of FIG. 1.
FIG. 3 is a side schematic view of the device of FIG. 1 in contact with an object to produce a non-vertical orientation.
FIG. 4 is a side schematic view of the device of FIG. 1 in contact with an object to produce another non-vertical orientation.
FIG. 5 is a perspective view of a hanger of the preferred embodiment of the invention.
FIG. 6 is a perspective view of an alternate embodiment of a hanger of the preferred embodiment of the invention.
FIG. 7 is a side elevational view of the top of the preferred embodiment of the invention.
FIG. 8 is a side schematic view of the device of FIG. 7 freely hanging vertically from its front notch.
FIG. 9 is a side schematic view of the device of FIG. 7 with the hanger moved to a more rearward position to produce a vertical orientation of the CDU.
FIG. 10 is a side schematic view of the device of FIG. 7 with the hanger moved to its most rearward position to produce a vertical orientation of the CDU.
FIG. 11 is a side elevational view of another embodiment of the invention.
FIG. 12 is a side elevational view of another embodiment of the invention.
FIG. 13 is a perspective view of the embodiment of FIG. 12.
FIG. 14 is a plan view of the embodiment of FIG. 12.
DETAILED DESCRIPTION OF THE INVENTION
In the description that follows, like elements, whether described above or below, are referred to with like reference numbers. The invention includes a hanger 28 (FIGS. 5 and 6). Hanger 28 includes a curved end 20 and a mount piece 30 connected by a connecting piece 32. In the preferred embodiment, mount piece 30 extends from connecting piece 32 at substantially a right angle to the plane containing curved end 20 and connecting piece 32. In this embodiment, mount piece 30 is formed by bending the material of mount piece 30 into a hook shape.
In an alternate embodiment of hanger 28 shown in FIG. 6, a mount piece 30 extends from connecting piece 32 at substantially a right angle to the plane containing curved end 20 and connecting piece 32. In this embodiment, mount piece 30 ends in a knob 34 having a larger diameter that mount piece 30. In either embodiment of hanger 28, mount piece 30 is preferably circular in cross-section although other cross-sectional shapes may be used as will be clear to those skilled in the art.
In either embodiment of hanger 28, curved end 20 is preferably hook shaped with a radius of curvature to fit over a bedframe piece such as shown in FIG. 1 and designated 16 or similarly sized piece. In this way, when curved end 20 is placed over the bedframe piece, the hanger 28 will be supported by curved end 20.
In the preferred embodiment of the invention shown in FIGS. 7 through 10, an improved hanger mount is generally labeled 36. Each hanger mount 36 corresponds to a hanger 28 and is attached to CDU 2 at opposite top sides 12 of CDU 2. Each mount 36 comprises a bar 38 having a front end piece 40 and a back end piece 42. Bar 38 is connected to the top 4 of the CDU 2 by front end piece 40 that is located approximately above intersection point 24 when the CDU 2 is vertical. Front end piece 40 preferably extends away from top 4 at a right angle.
Bar 38 is connected to the top 4 of CDU 2 near CDU back 8 by back end piece 42. Back end piece 42 also preferably extends away from top 4 at a right angle.
A front bend 44 on bar 38 is located a distance C from top 4 along front end piece 40. Front bend 44 directs bar 38 substantially toward the plane formed by CDU back 8 and slightly back toward top 4. A front notch 46 is formed on the inside surface of front bend 44.
A back bend 48 on bar 38 is located a distance D above the back edge of top 4 along back end piece 42. Distance D is preferably less than distance C although it is not required to be so. Back bend 48 directs bar 38 toward front bend 44. A back notch 50 is formed on the inside surface of back bend 48. Bar 38 extends from front bend 44 to back bend 48 so that a closed loop is formed by bar 38 from the top 4 above the intersection point 24 of CDU 2 when CDU 2 is hanging vertically, through front end piece 40, front bend 44, bar 38, back bend 48 and back end piece 42 to top 4 near CDU back 8.
Front connector 52 and back connector 54 connect front end piece 40 and back end piece 42 to top 4, respectively. Front and back connectors 52, 54 may be any type of appropriate connector as will be clearly understood by those in the art.
In the preferred embodiment shown in FIG. 7, bar 38 includes at least one middle notch 56 on the inside of bar 38 between front notch 46 and back notch 50. Notches 46, 50 and 56 are preferably arcuate and sized to have a slightly larger radius than the cross-sectional radius of mount piece 30 to allow mount piece 30 to be securely positioned therein as described hereafter and yet allow hanger 28 to freely rotate within notches 46, 50 and 56 when mount piece 30 is placed in notches 46, 50 and 56 as will be described hereafter.
In the preferred embodiment, mount piece 30 is placed around one of notches 46, 50 or 56 in a cupping fashion so that the curved end 20 of hanger 28 is above notches 46, 50 or 56. Mount piece 30 is held in place within the respective notch by contact between mount piece 30 and the inside surface of the respective notch.
In the alternate embodiment of hanger 28 shown in FIG. 6, contact between knob 34 and the inside surface of notches 46, 50 or 56 prevents mount piece 30 from inadvertently moving out of contact with the respective notch that mount piece 30 is placed in contact with.
In operation of the invention, the curved end 20 of hanger 28 is placed over a bedframe piece 16 such as shown in FIG. 1 or similar device. When CDU 2 can freely hang from bedframe piece, the mount piece 30 is placed in front notch 46 so that intersection point 24 is located directly below front notch 46 and CDU 2 hangs in a vertical position as shown in FIG. 8. This vertical position allows the indicia 26 on the CDU front 6 to be accurately aligned-with the top surface of the material collected so that an accurate representation of the volume of material collected may be easily made.
If an object A contacts CDU back 8 and moves CDU 2 away from its vertical position or if CDU 2 is hung from a bedframe piece or similar device and an object A prevents CDU 2 from hanging vertically, mount piece 30 is moved sequentially from front notch 46 to middle notches 56 toward back notch 50. In moving mount piece 30 from front notch 46 to middle notches 56 and back notch 50, when mount piece 30 is positioned in a notch so that CDU 2 hangs in a vertical position (FIG. 9), no further movement along bar 38 from notch to notch is required. With CDU 2 in a vertical position, the alignment of indicia 26 with the top surface of the material collected will convey an accurate representation of the volume of material collected.
If, however, mount piece 30 is moved to back notch 50 and CDU 2 is still not completely vertical (FIG. 10), then placing mount piece 30 in back notch 50 at least allows CDU 2 to be more vertical than it would have been if mount piece 30 were constrained to remain in a position corresponding to the location of front notch 46, as it is in prior art devices. With mount piece 30 in position in back notch 50, when indicia 26 is aligned with the top surface of the material collected, the volume represented by the aligned indicia 26 will more accurately represent the volume of the material collected than would otherwise be possible.
As stated above, in the preferred embodiment, both front and back end pieces 40, 42 extend from top 4 at right angles to top 4. However, either front end piece 40 or back end piece 42, or both, may be attached to top 4 by front connector 52 and back connector 54, respectively, at angles other than 90°.
Further, although in the preferred embodiment the bar 38 extending between front bend 44 and back bend 48 is straight, bar 38 may be other than straight. In particular, bar 38 may be convex or concave curved relative to top 4.
FIG. 11 shows an alternate embodiment of the hanger mount 36. In this alternate embodiment, only notches 46 and 50 are present. In all other ways, the embodiment of FIG. 11 is identical to the preferred embodiment. In this embodiment, mount piece 30 may be placed in either front notch 46 or back notch 50. In use, if CDU 2 is able to freely hang in a vertical position, mount piece 30 should be placed in front notch 46 (FIG. 11 with hanger 28 shown in solid outline) so that indicia 26 will be precisely aligned with the top surface of the material collected to accurately represent the volume of material collected.
If an object A moves CDU 2 from its vertical position or is present when CDU 2 is hung to prevent CDU 2 from hanging vertically when mount piece 30 is placed in front notch 46, the decision whether to place mount piece 30 in front notch 46 or back notch 50 will depend on which positioning of mount piece 30 produces the most vertical alignment of CDU 2 so that an accurate representation of the volume of material collected can be ascertained by aligning indicia 26 with the top surface of the material collected. Mount piece 30 is shown in FIG. 11 in phantom placed in back notch 50.
In this embodiment, as in the preferred embodiment, either front end piece 40 or back end piece 42, or both, may also be attached to top 4 by front connector 52 and back connector 54, respectively, at angles other than 90°.
FIGS. 12 through 14 show an alternate embodiment of the invention. In this embodiment, each hanger mount 36 is attached to or near the top 4 of CDU 2 through front connector 52' and back connector 54' at substantially a right angle to the corresponding top sides 12 of CDU 2 and in substantially the same or a parallel plane to top 4. Connector 52' attaches front end piece 40 to 4 near the center point between CDU front 6 and CDU back 8. Connector 52' attaches back end piece 42 to top 4 at CDU back 8. As can be seen, hanger mount 36 in this embodiment extends from CDU 2 at approximately a right angle to sides 10. Front and back connectors 50', 52' may be any type of appropriate connector as will be clearly understood by those in the art.
In this embodiment, modifications of either embodiment of mount 36 described above may be used. The preferred embodiment of mount 36 is modified in this embodiment to move notches 46, 50 and 56 to a downward directed location along bar 38 between front and back end pieces 40, 42. In addition, the lengths C and D from the points of connection of front and back end pieces 40, 42 to front and back bends 44, 48, respectively, are preferably equal.
In this embodiment of hanger mount 36, either embodiment of mount piece 30 may be used to support the hanger mount 36, and consequently the CDU 2, from the bedframe piece 16 or similar object. Either embodiment of hanger 28 supports bar 38 at either front or back bend 44, 48 by contact between mount piece 30 and whatever notch 46, 50 or 56 mount piece 30 is placed in. The operation of mount 36 in this embodiment with respect to the placement of mount piece 30 in notches 46, 50 or 56 is exactly as described above in connection with the embodiments described above.
In all the embodiments, hanger 28 and hanger mount 36 may be made of any rigid material, including but not limited to, metals and plastics. The material used for hanger mount 36 will help to determine the appropriate connectors 52, 54, 52' and 54' as will be clear-to those skilled in the art.
The invention has been described as an assembly for supporting a chest drainage unit from a bedrail or similar object as will be clear to those skilled in the art. However, the assembly may also be used to support other medical devices where it is desirable to maintain a substantially vertical orientation despite contact with an object that, but for the use of the assembly of the present invention, would tend to move the medical device from the vertical orientation. Examples of such medical devices include, but are not limited to, sharps containers, autotransfusion blood devices, enteral feeding pumps and feeding bags, suction canisters, and urine drainage bags to name but a few of the possibilities.
The invention has been described in connection with specific embodiments. These embodiments have been described to illustrate the invention and not for the purpose of limiting the invention precisely to the description contained herein. Changes and modification may be made to the description given and still be within the scope of the invention as claimed. Further, obvious changes and modifications will occur to those skilled in the art.
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A CDU hanger mount assembly and hanger is provided. The mount assembly and hanger allows the CDU to be supported by an object for supporting the CDU while the connecting point between the hanger mount and the pivot end of the hanger may be selectively moved from a point midway between the front and back of the CDU top toward the back of the CDU. This allows the CDU to be less displaced from the vertical upon displacing contact with an object such as a bedframe piece. The hanger and hanger mount assembly allows the alignment of the indicia on the CDU with the top surface of the material collected in the CDU to be a more accurate representation of the actual volume of material collected in the CDU. The mount assembly and hanger may also be used with medical devices other than CDUs.
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This application is a division of copending Ser. No. 513,792 filed Oct. 10, 1974; which is a continuation of Ser. No. 452,305 filed Mar. 18, 1974, now abandoned.
BACKGROUND OF THE INVENTION
This invention relates to novel compounds useful as intermediates for making ether polycarboxylates.
It is known that ether polycarboxylates represented by the formula ##STR1## wherein M is alkali metal and X is hydrogen or COOM are useful as complexing agents for metal and alkaline earth metal ions and as detergency builders. Although methods for synthesis of such compounds (e.g., via Williamson ether type synthesis) have been disclosed, alternate processes for their preparation are desired. Accordingly, the provision of novel intermediates suitable for use in such alternate processes constitutes a significant contribution to the art.
SUMMARY OF THE INVENTION
This invention provides novel imide carboxylates, O-carboxylates thereof and amide carboxylates useful as intermediates for the preparation of the above described ether polycarboxylates and their acids and esters which are also intermediates for preparation of the salts. These compounds and their synthesis and use will be understood from the following description of the preferred embodiments.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
The carboxylates of this invention are: imide carboxylates represented by the formula ##STR2## wherein the R' substituents are hydrogen, COOM', M' being alkali metal, ammonium or one-half magnesium (at least one R' substituent must be COOM') and the R" substituent is an alkyl group containing from 1 to 12 carbon atoms, phenyl, or COOM; acids and esters of such imide carboxylates; O-carboxylates of such imide carboxylates; amide carboxylates represented by the formula ##STR3## wherein R IV is an alkyl group containing 1 to 12 carbon atoms, hydrogen, M' or a phenyl group having 0 to 3 alkyl substituents containing 1 to 12 carbon atoms each and at least one of the R' substituents attached to a carbon atom is COOM'; and acids and esters of such amide carboxylates.
The carboxylates of this invention can be prepared by carboxylating one or both heterocyclic CH 2 moieties of imides represented by the formula ##STR4## wherein R is hydrogen, an alkyl group containing from 1 to 12 carbon atoms or phenyl. (Such imides and methods for their preparation are known.) In some carboxylation procedures when R is hydrogen, the imide nitrogen may also be carboxylated. Generally, carboxylation of the imide will result in only monocarboxylation of one or both CH 2 moieties, however, under particularly severe carboxylation conditions, either or both CH 2 moieties may be dicarboxylated. Thus, the imide carboxylates formed can be represented by the formula wherein R' is hydrogen or COOM' (M' being alkali metal, ammonium or one-half magnesium) and R" is an alkyl group containing 1 to 12 carbon atoms, phenyl, or COOM. At least one of the R' substituents must be COOM', it being understood that the R' substituents need not be identical. Depending on carboxylation conditions, acid or ester forms of such imide carboxylates, rather than the salt forms, can be obtained. Of course, the salt forms can also be converted to the acid or ester forms by conventional acidulation and esterification reactions. It will be recognized that certain imide carboxylates may exhibit enolate forms, e.g. ##STR5## If M' is one-half Mg or ##STR6## if M' is a monovalent metal. Although the imide carboxylates used in this invention are, for convenience, represented in both the specification and claims by the keto structure (I), this representation is intended to encompass the enolate forms of such compounds which may exist under various conditions.
Under carboxylation conditions, the imides and/or their carboxylates can form O-carboxylates (i.e., carbonates) ##STR7## Such O-carboxylates are designated herein in the specification and claims as O-carboxylates of the imide carboxylates to clearly indicate their relationship to the imide carboxylates and to avoid the proliferation of nomenclature which would otherwise be required to designate configurations possible when one or both imide oxygens are carboxylated. It is to be understood, however, that no limitation that the O-carboxylates of the imide carboxylates must be derived from imide carboxylates is intended.
If the carboxylation reaction is conducted in the presence of alcohols, water, or a base, amide carboxylates ##STR8## will be formed (such amide carboxylates can also be formed if the imide carboxylates are subsequently reacted with alcohol, water or a base) which upon further carboxylation will yield ##STR9## Thus, the above amide carboxylates can be collectively represented by the formula ##STR10## In the above three formulae, R IV is hydrogen, M', an alkyl group containing 1 to 12 carbon atoms, phenyl, or phenyl substituted with up to three alkyl groups containing 1 to 12 carbon atoms each and at least one of the R' substituents attached to a carbon atom is COOM'.
The desired ##STR11## product or acids or esters thereof are obtained by hydrolyzing the imide or amide linkages of the above described imide carboxylates, O-carboxylates thereof and amide carboxylates. The term "hydrolyzing" is defined as encompassing hydrolysis reactions conducted in either acid or basic media or in the presence of alcohols in order to obtain the salt, acid or ester form as desired.
Hydrolysis, for example, by reaction of an alkali metal base (e.g., alkali metal hydroxide, carbonate, or bicarbonate) with carboxylates in which one O-linked carbon atoms is carboxylated will yield ##STR12## whereas reaction with carboxylates in which both -O-linked carbon atoms are carboxylated will yield ##STR13## Dicarboxylated -O-linked carbon atoms, if formed, may lose one of the carboxylate substituents via decarboxylation in the hydrolysis reaction. The NR" moiety will be split out as an amine (or ammonia, if R" is COOM) in the reaction. The use of carboxylates wherein at least one R' substituent on each -O-linked carbon is hydrogen is preferred since such compounds are more easily formed than those containing dicarboxylated carbons.
The use of carboxylates in which only one -O-linked carbon is carboxylated is generally preferred since the ether tricarboxylate obtained by hydrolysis appears more readily biodegradable than the ether tetracarboxylates obtained from compounds in which both -O-linked carbons are carboxylated. However, in some applications mixtures of ether tri- and tetra- carboxylates provide superior builder performance, rendering the use of mixtures of compounds in which one and in which both -O-linked carbon atoms are carboxylated desirable.
Preferably, the above described imide carboxylates, O-carboxylates thereof and amide carboxylates of this invention are obtained by carboxylation of the imide as shown. All of the carboxylates described, including the acid and ester forms thereof, are considered as carboxylation products obtained by carboxylating at least one CH 2 moiety of the imide. It will be understood that the particular carboxylates or mixtures thereof obtained with be dependent on the carboxylation conditions and whether or not the water, alcohol or base required for amide carboxylate formation is present.
The carboxylation of the imide is preferably conducted in a solvent. Any solvent which does not participate unduly in competitive side reactions can be employed. In general, aprotic solvents having relatively high (1 or greater) dipole moments and dielectric constants greater than 10 or solvent mixtures containing at least 30% of such high dipole moment solvents are preferred since the use of solvents of higher dipole moments usually results in higher yields, particularly when alkali metal phenate - carbon dioxide complexes are employed as carboxylating agents as hereinafter described. For example, solvents such as dimethylformamide, hexamethyl phosphoric triamide, pyridine, dimethyl sulfoxide, tetramethylurea, N-methylpyrolidone, bis-2-methoxy ethyl ether, tetrahydrofuran and ethyl acetate can be employed for most carboxylation reactions. In some instances, the use of mixed solvent systems (including systems containing low dipole moment solvents such as benzene, toluene, hexane, etc., which, when used alone, do not generally provide good yields) improves yields and/or minimizes gel formation. Optimum solvents or solvent mixtures for particular reaction systems can be determined by routine testing.
If desired, the carboxylated imide can be separated from the reaction mixture by conventional means such as filtration, centrifugation, etc. In some instances, such as when alkali metal phenate --CO 2 complexes are employed as carboxylating agent, unreacted imide, phenol, and solvent may be somewhat difficult to separate from the carboxylated imide by mechanical means. In such cases, separation can be conveniently accomplished by adding water to form an aqueous phase containing the carboxylate and extracting the aqueous phase with a water immiscible solvent for the imide and phenol (but not the carboxylate) e.g., toluene or chloroform.
In one preferred method of making compounds of this invention, an imide, N-alkyl 3,5-morpholinedione is carboxylated by reaction with methyl methoxy magnesium carbonate. The carboxylation is preferably conducted in a solvent such as dimethyl formamide or a mixture of dimethyl formamide and bis-2-methoxy ethyl ether at temperatures of from 100° to 160° C., preferably 135° to 145° C. to provide reasonable reaction rates commensurate with minimum thermal decomposition. (This temperature range is convenient at atmospheric pressure. If pressures are reduced to facilitate methanol removal, the temperature range can be lowered). This reaction, depending on concentration of reactants, length of reaction time, etc., can yield imide carboxylates in which one CH 2 moiety is carboxylated or in which both CH 2 moieties are carboxylated, or mixtures thereof. The ratio of compounds in which both CH 2 moieties are carboxylated can be increased by increasing the ratio of carboxylating agent to imide and/or prolonging the reaction. The ratio can, of course, be decreased by decreasing the amount of carboxylating agent and/or the reaction time.
The magnesium carboxylates thus obtained can be reacted with an alkali metal hydroxide to yield a mixture of ether tri- and tetra- carboxylates. Preferably, however, the magnesium carboxylates are first dissolved in cold phosphoric acid and treated with ammonia to precipitate magnesium and form the ammonium carboxylates which are then reacted with the alkali metal hydroxide.
In another preferred embodiment of making compounds of the invention, the imide is carboxylated by reaction with a carboxylating agent formed by combining carbon dioxide with a phenate represented by the formula ##STR14## wherein R'" is an alkyl group containing from 1 to 12 carbon atoms and n is an integer from 0 to 3. (Carboxylating agents of this type are described in U.S. Pat. No. 3,658,874, the disclosure of said patent being incorporated herein by reference). The carboxylation is preferably conducted in a high dipole moment solvent as previously discussed at temperatures of from 0° to 150° C., preferably 25° C. to 100° C. under sufficient pressure to prevent loss of carbon dioxide. Solvent, temperature, and pressure will, of course, be correlated to optimize solubility, reaction rate, etc. The reaction can provide imide carboxylates in which one or both CH 2 moieties are carboxylated, or mixtures thereof. The relative amounts of these compounds can be varied by adjustment of the amount of carboxylating agent and reaction time as in the previously described embodiment of this invention. This embodiment also generally leads to the formation of O-carboxylates, e.g. ##STR15## as well as imide carboxylates.
Carboxylation of the imide can also be accomplished in multiple step reactions. For example, the imide ##STR16## can be reacted with lithium diisopropyl amide (preferably in tetrahydrofuran at about -40° C. to -70° C.) and the reaction product treated with carbon dioxide to carboxylate (COOLi substituents) one CH 2 moiety and the imide nitrogen.
Carboxylation of imides can also be accomplished by using an alkali metal carbonate salt under CO 2 pressure, preferably at a temperature between 140° C. - 270° C. Conversion rate generally increases as CO 2 pressure increases. The CO 2 pressure required to obtain a particular conversion rate can be reduced by use of catalysts such as group VIII transition metals and their derivatives, for example, iron and nickel, and group IB and VB metals and their derivatives. The use solvents such as of molten low melting salts, e.g. sodium formate as solvents can accelerate the reaction, improve heat transfer, and facilitate removal of reaction products.
Other suitable carboxylating agents and optimum conditions for their use can be determined by routine testing.
Preferably, the carboxylates (I, II, III) are reacted with alkali metal base (usually at least 2% stoichiometric excess base and temperatures of 90° C. to 150° C. are employed) to yield ##STR17##
Alternately, these products can be obtained by acid hydrolysis of such carboxylates (preferably with aqueous mineral acid at temperatures of 25° C to 100° C.) and neutralization of the hydrolysis product with alkali metal base. Generally, the direct reaction of the carboxylate with alkali metal base is preferred to avoid possible decarboxylation during hydrolysis and/or salt formation. The use of sodium or potassium hydroxide, particularly sodium hydroxide in the saponification or neutralization reaction is preferred in view of the preference for the corresponding sodium or potassium ether carboxylates as detergency builders.
The preparation of compounds of this invention and their utility is further illustrated by the following examples wherein all parts and percentages are by weight unless otherwise indicated.
EXAMPLE I
About 14 grams sodium phenoxide in 100 ml. dimethylformamide is stirred under a carbon dioxide atmosphere, the temperature being allowed to rise from 25° C. to 33° C. over a period of 5 to 10 minutes. Formation of a precipitate which dissolves on further stirring as the mixture is allowed to cool to 25° C. is observed. After about 3 hours, the carbon dioxide atmosphere is replaced with nitrogen atmosphere and a solution of about 7.7 grams N-methyl 3,5-morpholinedione in 20 ml. of dimethylformamide is added to the mixture which is then allowed to stand for about 20 hours. The reaction mixture is poured into 200 ml. diethyl ether and filtered to isolate the imide carboxylate as a white solid which is dissolved in 100 ml. water. Sodium hydroxide (20 grams) is added and the solution is maintained at 85° C. for two hours with stirring. The solution is concentrated to about 50 ml. by vacuum distillation.
Addition of 200 ml. methanol precipitates a solid product identified by nuclear magnetic resonance analysis as ##STR18## Repeating the above procedure using a 4:1 mole ratio of carboxylating agent to imide yields a mixture of ##STR19##
EXAMPLE II
About 115 ml. 2.3 molar hexane solution of n-butyllithium is added, under nitrogen atmosphere, to a mixture of 400 ml. tetrahydrofuran and 24 grams diisopropyl amine precooled to -40° C. The mixture is cooled to -70° C. and a solution of 12.5 grams 3,5-morpholinedione in 100 ml. tetrahydrofuran is added and a stream of carbon dioxide is bubbled into the mixture for about one hour. The mixture is evaporated, leaving a dry powder residue containing ##STR20## which is dissolved in 150 ml. water and passed through an acid ion exchange column (packed with a sulfonated polystyrene resin marketed by Fisher Scientific Company under the trademark REXYN 101). The acid solution is neutralized with sodium hydroxide. Nuclear magnetic resonance analysis shows the solution to contain sodium 3,5-morpholinedione-2-carboxylate. Reaction of this product with hot sodium hydroxide and addition of methanol as in Example I yields ##STR21##
EXAMPLE III
Carbon dioxide is bubbled through a mixture of about 16 grams of potassium phenoxide in 100 ml. dimethylformamide. The temperature rises from 25° C. to 41° C. in about 10 minutes and slowly drops back to 25° C., the formation and dissolution of a solid being observed. After three hours carbon dioxide bubbling is stopped and the mixture is placed under nitrogen atmosphere, a solution of 7.7 grams N-methyl 3,5-morpholinedione in 15 ml. dimethylformamide is added and the mixture allowed to stand 4 days at about 25° C. The mixture is then poured into 200 ml. diethyl ether and filtered to recover a solid which is dissolved in 100 ml. water and reacted with 20 grams sodium hydroxide at 85° C. for two hours to yield ##STR22## in admixture with some potassium salts.
EXAMPLE IV
About 0.05 mole N-methyl 3,5-morpholinedione in 12 ml. dimethylformamide is added over a period of about forty minutes to 1.4 mole methyl methoxy magnesium carbonate in 50 ml. of a 75%/25% mixture bis-2-methoxy ethyl ether/dimethylformamide and the resulting mixture is maintained in the temperature range of 120° to 140° C. for one hour. The mixture is poured into 200 ml. ethyl ether and filtered to recover solid magnesium imide carboxylate product which is added to aqueous phosphoric acid (containing 1 mole H 3 PO 4 per mole of magnesium in the original methyl methoxy magnesium carbonate solution) and the resulting solution is neutralized to a pH of 9 with ammonia, forming ammonium salt of the carboxylate and precipitating the magnesium as hydrated MgNH 4 PO 4 . The carboxylate solution is separated from the precipitate by filtration and reacted with excess sodium hydroxide for two hours at 85° C. to yield ##STR23##
EXAMPLE V
About 12.9 grams N-methyl 3,5-morpholinedione and 41.5 grams potassium carbonate are heated to 200° C. under CO 2 pressure of 200 atmospheres for about 21/2 hours. The product is cooled, dissolved in water. Potassium hydroxide is added and the mixture boiled to remove methyl amine and evaporated to dryness. Analysis shows the product to contain ##STR24##
EXAMPLE VI
Two mixtures containing 1 mole N-methyl 3,5-morpholinedione and 3 moles sodium carbonate are prepared. One mixture is heated to and maintained at about 215° C. under 150 atmospheres carbon dioxide pressure for two hours. The other mixture is treated in the same manner after being admixed with 2 moles sodium formate.
Both mixtures are then cooled, dissolved in water, reacted with sodium hydroxide and heated to expel methyl amine.
Analysis shows both mixtures to contain ##STR25## with about five-fold greater yield being obtained from the sodium formate containing mixture. It is believed that the sodium formate promotes the reaction by functioning as a solvent for the N-methyl 3,5-morpholinedione sodium carbonate mixture.
EXAMPLE VII
About 0.05 mole N-methyl 3,5-morpholinedione in 12 ml. dimethylformamide is added over a period of about forty minutes to 1.4 mole methyl methoxy magnesium carbonate in 50 ml. of a 75%/25% mixture bis-2-methoxy ethyl ether/dimethylformamide and the resulting mixture is maintained in the temperature range of 120° to 140° C. for one hour. The mixture is poured into 200 ml. ethyl ether and filtered to recover solid magnesium imide carboxylate product which is added to aqueous phosphoric acid (containing 1 mole H 3 PO 4 per mole to magnesium in the original methyl methoxy magnesium carbonate solution) and the resulting solution is neutralized to a pH of 9 with ammonia, forming ammonium salt of the carboxylate and precipitating the magnesium as hydrated MgNH 4 PO 4 .
The carboxylate solution is separated from the precipitate by filtration and is concentrated to a syrup-like consistency. Ethyl alcohol is added and crystals of ##STR26## precipitate. This product is boiled in sodium hydroxide solution to expel ammonia and amine and yield
EXAMPLES VIII - X
The procedure of Example I is repeated with the imides shown in the following table being substituted for N-methyl 3,5-morpholinedione:
______________________________________EXAMPLE IMIDE______________________________________VIII ##STR27##IX ##STR28## ##STR29##______________________________________
In each example, the product ##STR30## is obtained.
EXAMPLE XI
The procedure of Example I is repeated using various solvents shown in the following table and a 2:1 mole ratio of carboxylating agent to imide. Product yields are shown based on imide charged to the reactions.
__________________________________________________________________________ % yield % yield Solvent Dipole Moment Donicity ##STR31## ##STR32##__________________________________________________________________________dimethylformamide 3.86 26.6 48 <1hexamethylphosphotri-amide 4.31 38.8 68 2ethylacetate 1.88 17.1 16 <1bis-2-methoxy notethyl ether 1.97 determined 22 3nitrobenzene 4.03 4.4 1 <1tetramethylurea 3.47 29.6 44 2hexane 0.085 not 1 <1 determinedacetonitrile 3.44 14.1 24 <1dimethyl-sulfoxide 3.9 29.8 49 <1tetrahydro-furan 1.75 20.0 23 1N-methyl- notpyrolidone 4.09 determined 46 1benzene 0 4.9 <1 <1 (calculated)pyridine 2.37 33.1 40 1toluene 0.31 not 2 <1 determined__________________________________________________________________________
It is seen from the above data that high dipole moment and donicity (a measure of basicity) generally are correlated with higher yields.
EXAMPLE XII
Anhydrous sodium phenate (232 gms) is dispersed in a mixed solvent consisting of 350 ml. toluene and 350 ml. dimethylformamide. Carbon dioxide is sparged into the mixture for about 30 minutes, temperature of the mixture being maintained at 25° C. Crystalline N-methyl 3,5-morpholinedione (128 gms) is added and the mixture is maintained at 45° C. under about 1.7 atmospheres carbon dioxide pressure. About 800 ml. water is added to the reaction mixture containing carboxylate product, predominantly. ##STR33## a major portion of which is converted to ##STR34## by hydrolysis.
An aqueous phase containing the carboxylates and sodium bicarbonate is separated. The aqueous phase is extracted with chloroform to remove residual solvent. Sodium hydroxide is added to the aqueous phase which is then boiled to convert the imide carboxylates and hydrolysis products thereof to trisodium 2 oxa-1,1,3-propane tricarboxylate.
The organic phase and chloroform extract are combined and distilled to recover unreacted N-methyl 3,5-morpholinedione which is recycled.
EXAMPLE XIII
One liter of a 2 molar solution of sodium phenate in pyridine is prepared by distilling a mixture of phenol, 50% aqueous sodium hydroxide and pyridine to remove water. The solution is cooled to 50° C. and sparged with carbon dioxide for about 30 minutes. One gram mole of N-methyl 3,5-morpholinedione is added and the reaction mixture is maintained at 50° C. for 4 hours. About 800 ml. of water is added and the mixture is counter currently extracted with 800 ml. toluene in three stages to remove phenol, unreacted N-methyl 3,5-morpholinedione and pyridine. The remaining aqueous phase is boiled to drive off any remaining solvent and consume carbonate by the reactions ##STR35##
Sodium hydroxide is added to convert remaining imide carboxylate and amide carboxylate to ##STR36##
The organic phase is distilled to recover raw materials and solvents which are recycled.
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Novel imide carboxylates, O-carboxylates thereof, and amide carboxylates are useful as intermediates for preparation of sequestrant compounds.
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FIELD AND BACKGROUND OF THE INVENTION
The present invention relates to devices and methods for providing network access control utilizing traffic-regulation hardware.
In recent years, security has become an increasing concern in information systems. This issue has become more significant with the advent of the Internet and the ubiquitous use of network environments (e.g. LAN and WAN). Methods that regulate network access based on network traffic have primarily used software solutions. A hardware solution can offer better tamper-proof performance in an inexpensive, low-profile unit. Such a solution would require minimal management infrastructure and no need for maintenance.
In the prior art, there are known network connectors, for protecting against unauthorized access, which can send unauthenticated traffic to a “substitution” device. Other methods include filtering based on an Ethernet exchanger and receive filtering using a hardware-based limited packet filter. However, techniques for providing network access control utilizing traffic-regulation hardware are not known in the art.
It would be desirable to have devices and methods for providing network access control utilizing traffic-regulation hardware.
SUMMARY OF THE INVENTION
It is the purpose of the present invention to provide devices and methods for providing network access control (NAC) utilizing traffic-regulation hardware.
For the purpose of clarity, the term “NAC device” is used herein to refer to a hardware device that provides network access control utilizing traffic-regulation hardware. The term “zeroize” is used herein to refer to resetting the NAC device to its initialization mode.
Preferred embodiments of the present invention provide solutions to NAC problems via a small embedded device that can be installed in-line on an Ethernet cable between a client system and an access switch, typically inserted into a switch port. The device includes one or more hardware relays. Each relay controls exactly one physical line (e.g. 100 Mb or 1 Gb Ethernet). When the relay is open, network traffic only flows through a packet filter, which may be implemented in software or hardware. This mode may be slower than the full rate of the network line. When the relay is closed, traffic flows freely.
When the relay is closed and traffic flows at full speed, the device checks for specially-formatted “alert” packets. When such an alert packet is detected, the device automatically opens the relay, and resumes packet inspection and filtering. The device may be powered by a battery, or may use power derived from the network line (e.g. Power Over Ethernet (POE)).
Therefore, according to the present invention, there is provided for the first time a device for providing network access control utilizing traffic-regulation hardware, the device including: (a) at least one client-side port for operationally connecting to a client system; (b) at least one network-side port for operationally connecting to a network; (c) a logic module for regulating network traffic, based on device-related data, between at least one client-side port and at least one network-side port, the logic module including: (i) a memory unit for storing and loading the device-related data; and (ii) a CPU for processing the device-related data; and (d) at least one relay, between at least one respective client-side port and at least one respective network-side port, configured to open upon receiving a respective network-access-denial command from the logic module.
Preferably, the device is powered by the network.
Preferably, the device further includes: (e) a battery for powering the device.
Preferably, the device further includes: (e) a reset mechanism for zeroizing the device.
Preferably, the device further includes: (e) a status indicator for indicating at least one operational status of the device.
Preferably, the device further includes: (e) a packet-matching module for detecting the device-related data from the network while the CPU is idle.
More preferably, the packet-matching module is configured to detect an alert packet from the network.
More preferably, the network-access-denial command is generated based on receiving the alert packet.
Most preferably, the non-volatile memory is configured to store a packet-filtering policy, wherein the packet-filtering policy is determined by a policy decision-point operationally connected to the network.
Preferably, the logic module is configured to maintain an open-relay line-rate when at least one relay is open, and to maintain a closed-relay line-rate when at least one relay is closed.
According to the present invention, there is provided for the first time a method for providing network access control utilizing traffic-regulation hardware, the method including the steps of: (a) operationally connecting a client-side port to a client system; (b) operationally connecting a network-side port to a network; (c) regulating network traffic, based on device-related data, between the client-side port and the network-side port; and (d) upon receiving a network-access-denial command, opening a relay between the client-side port and the network-side port.
Preferably, the method further includes the step of: (e) prior to the step of regulating, detecting the device-related data from the network.
More preferably, the step of detecting includes detecting an alert packet from the network.
More preferably, the network-access-denial command is generated based on receiving the alert packet.
Most preferably, the step of detecting the alert packet is based on a packet-filtering policy determined by a decision-point policy operationally connected to the network.
Preferably, the step of regulating includes maintaining a open-relay line-rate when the relay is open, and maintaining a closed-relay line-rate when the relay is closed.
These and further embodiments will be apparent from the detailed description and examples that follow.
BRIEF DESCRIPTION OF THE DRAWINGS
The present invention is herein described, by way of example only, with reference to the accompanying drawings, wherein:
FIG. 1 is a simplified schematic block diagram of an NAC device, according to preferred embodiments of the present invention;
FIG. 2 is a simplified schematic block diagram of the NAC device of FIG. 1 implemented in a typical network-architecture configuration, according to preferred embodiments of the present invention;
FIG. 3 is a simplified operational scheme of the initialization and operational modes for the NAC device of FIG. 1 , according to preferred embodiments of the present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
The present invention relates to devices and methods for providing network access control utilizing traffic-regulation hardware. The principles and operation for providing network access control utilizing traffic-regulation hardware, according to the present invention, may be better understood with reference to the accompanying description and the drawings.
Referring now to the drawings, FIG. 1 is a simplified schematic block diagram of an NAC device, according to preferred embodiments of the present invention. A NAC device 10 is shown having a client port 12 and a status indicator 14 (e.g. for indicating failure or low battery) located on a client side 16 . A network port 18 is shown located on a network side 20 . Client port 12 can be any standard port (e.g. a female RJ-45 connector) for connecting to client systems. Network port 18 can be any standard port (e.g. a male RJ-45 connector) for connecting to a network switch. While only one port (i.e. client port 12 and network port 18 ) is shown in FIG. 1 on client side 16 and network side 20 , it is noted that a plurality of ports can be configured into NAC device 10 on either or both sides.
A logic module 22 houses memory and processing components (e.g. CPU, RAM, flash-memory chip). A packet-matching module 24 is used for detecting alert packets in the network traffic to NAC device 10 . An optional battery 26 provides power to NAC device 10 . Alternatively, NAC device 10 may be powered from the network line (e.g. using POE). Since NAC device 10 is primarily a passive device, a reset button 28 is used to zeroize NAC device 10 . In implementations in which battery 26 is used, NAC device 10 can report a battery level, or provide notification by activating (or deactivating) status indicator 14 .
An exemplary signal-routing scheme for NAC device 10 involves a client-side line A (e.g. 10/100 Ethernet) routed to logic module 22 which can transmit signals, via a line B (e.g. 10/100 Ethernet), to a network-side line C (e.g. 10/100/1000 Ethernet). A physical relay D can serves to connect client-side line A to network-side line C and vice-versa. In implementations having a plurality of ports, a plurality of respective relays D is implemented as well. A line E (e.g. 10/100/1000 Ethernet) can transmit signals from packet-matching module 24 to network-side line C. The protocol for allowing the routing of various signal paths is described below in regard to FIG. 3 .
Line speed can be renegotiated without disconnecting a port. This prevents an end user from seeing indications that the port is disconnecting and reconnecting frequently. In addition, NAC device 10 can maintain different line rates at different times (e.g. a higher one when relay D is closed, and a lower rate when relay D is open).
FIG. 2 is a simplified schematic block diagram of the NAC device of FIG. 1 implemented in a typical network-architecture configuration, according to preferred embodiments of the present invention. A client system 30 (e.g. a PC) is shown having NAC agent software 32 . Client system 30 is operationally connected to client port 12 of NAC device 10 . An access switch 34 is operationally connected to network port 18 of NAC device 10 . Access switch 34 is operationally connected to a network 36 .
Network 36 can be a switched or routed network, and is typically connected to a DHCP/DNS server 38 . Network 36 is connected to a policy decision-point (PDP) 40 which is connected to security management servers. In preferred embodiments of the present invention, these servers are known as SmartCenter 42 and SmartDashboard 44 . Specifically, SmartDashboard 44 is a graphical management console, and SmartCenter 42 is a security management server, which stores and distributes the management configuration. SmartCenter 42 and smart dashboard 44 determine the access-control policy, which is jointly enforced by NAC device 10 and by PDP 40 .
Packet-matching module 24 is only active when relay D is open. In such a state, there is no direct (i.e. transparent) connectivity between client port 12 and network port 18 . All traffic is inspected by logic module 22 in this state. A packet-filtering policy (PFP) determines which network traffic is allowed in this state. The allowed traffic is typically only security-related (i.e. authentication) traffic. When relay D is closed, traffic flows too fast for logic module 22 to keep up. In such a scenario, logic module 22 enters an idle state until receiving an alert packet from PDP 40 .
FIG. 3 is a simplified operational scheme of the initialization and usage modes for the NAC device of FIG. 1 , according to preferred embodiments of the present invention. The process starts (Block 50 ), for first-time usage, with NAC device 10 in an “initialization” mode (block 52 ). Initialization can take place in the operational location (e.g. connected to NAC agent software 32 and/or access switch 34 of FIG. 2 ) of NAC device 10 , or NAC device 10 can be initialized in a more secure location, and then moved to its operational location. NAC device 10 then enters a “secure mode” (Block 54 ). The secure mode is a state in which no direct network traffic is allowed between client system 30 and network 36 . NAC device 10 can be zeroized (block 56 ), by activating reset button 28 , in order to return NAC device 10 to initialization mode (block 52 ).
As part of a network-side link-up (Block 58 ), NAC device 10 then acquires an IP address from DHCP server 38 or through other means. To determine PDP 40 , NAC device 10 queries DNS server 38 for an SRV (i.e. service) record, or discovers PDP 40 by other means. NAC device 10 connects to PDP 40 (e.g. by SSL), and receives the public key of PDP 40 . NAC device 10 stores the public key, which cannot be changed for the lifetime of NAC device 10 , in logic module 22 .
NAC device 10 is only willing to communicate with a PDP 40 that presents the stored public key. NAC device 10 also receives the PDP from PDP 40 . NAC device 10 receives the contents of an alert packet from PDP 40 . The PFP can be stored for an extended period of time in order to handle intermittent PDP failures NAC device 10 then enters a “transparent” mode (Block 60 ). The transparent mode is a state in which network traffic is allowed between client system 30 and network 36 , unless a PDP alert packet is received by NAC device 10 . NAC device 10 can be zeroized (block 64 ), by activating reset button 28 , in order to return NAC device 10 to initialization mode (block 52 ).
As part of a client-side link-up, client authentication, and PDP approval (Block 62 ), client system 30 , via NAC agent software 32 and NAC device 10 , authenticates itself to PDP 40 . Such traffic (i.e. authentication traffic) is allowed by the PFP of NAC device 10 . If authentication is successful, PDP 40 connects to NAC device 10 , and instructs NAC device 10 to close relay D. NAC device 10 then enters transparent mode (Block 60 ).
Client system 30 can be disconnected from network 36 either due to a client-side (or network-side) link-down or alert packet (Block 66 ). A client-side link-down occurs when the client-side link is broken. A network-side link-down occurs when the network-side link is broken. In the case that PDP 40 sends an alert packet to NAC device 10 , client system 30 is also disconnected. If client system 30 is disconnected, NAC device 10 goes into secure mode (Block 56 ). In such a situation, NAC device 10 requests a new PFP from PDP 40 . Until a new PFP is received, NAC device 10 uses the cached PFP stored in logic module 22 . If client system 30 is disconnected due to an alert packet, client system 30 will try to remediate its situation, and eventually will re-authenticate.
The alert packet uses a special frame to allow PDP 40 and/or client agent software 32 to alert NAC device 10 . This is similar to Wake-On-LAN (WOL), and can be similarly implemented. In such a configuration, NAC device 10 continuously “sniffs” the traffic when relay D is closed. WOL uses a “magic” UDP (layer 3) packet, which can be detected and routed by packet-matching module 24 of NAC device 10 . Such a UDP packet is also a broadcast packet, since NAC device 10 may not have an IP address at the time that the packet is received (e.g. a DHCP lease may have expired), and is only able to receive broadcast packets at this stage.
To protect against potential denial of service attacks, the alert packet should include some secured data. Either a nonce (i.e. cryptographic nonce in which a number or bit string is used only once in security engineering) can be allocated dynamically by PDP 40 , or the nonce can be static for each NAC device 10 (e.g. a hash of the MAC value and a secret value).
A “failure” mode (not shown in FIG. 3 ) can be indicated by status indicator 14 . The failure mode triggers a “fail-open” behavior for relay D, meaning that there is network connectivity. Such a failure mode applies to both software/firmware and hardware failures.
While the invention has been described with respect to a limited number of embodiments, it will be appreciated that many variations, modifications, and other applications of the invention may be made.
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Disclosed are devices and methods for providing network access control utilizing traffic-regulation hardware, the device including: at least one client-side port for operationally connecting to a client system; at least one network-side port for operationally connecting to a network; a logic module for regulating network traffic, based on device-related data, between the ports, the logic module including: a memory unit for storing and loading the device-related data; and a CPU for processing the device-related data; and at least one relay, between at least one respective client-side port and at least one respective network-side port, configured to open upon receiving a respective network-access-denial command from the logic module. Preferably, the logic module is configured to maintain an open-relay line-rate when at least one relay is open, and to maintain a closed-relay line-rate when at least one relay is closed.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a flange used for a base support (drum) of an electrophotographic photoconductor and, more particularly, to a flange made of synthetic resin, a flange processing device, and a method for processing a flange.
2. Description of the Related Art
In the electrophotographic photoconductor field for electrostatic image processing in electrostatic copiers, electrostatic printers, facsimiles, etc., a photoconductor drum is generally provided with a photosensitive layer at the uppermost surface and equipped with flanges in the openings formed at either ends of the photoconductor drum, and various types of units are arranged around it. While the photoconductor drum rotates, these units perform necessary or desired processes (e.g., selective exposure, development, image transfer, charge removal, and cleaning) on the photoconductor layer.
An electrophotographic photoconductor is fabricated by assembling together a cylindrical drum base support with a photosensitive layer that has been processed to a desired surface condition and centered flange members, i.e., the drum base support and flange members are separately manufactured and then assembled into a photoconductor.
As shown for instance in FIG. 14 , a flange member 10 made of synthetic resin or the like includes a flange part (or drum bumping part) 2 and an insertion part (or drum engagement part) 1 to be inserted into the inside of a cylindrical photoconductor drum (base support) 20 . The insertion part 1 protruding toward the movable side B is fitted to the inner side of the photoconductor drum 20 and serves to firmly fix the flange member 10 to the photoconductor drum 20 , and the flange part 2 serves to fix the positional relationship between the photoconductor drum 20 and flange member 10 by being bumped into the edge of the photoconductor drum 10 . The outer surface of the flange part 2 is provided with a helical gear 3 (hereinafter simply referred to as a “gear part” in some cases) that is engaged with a drive gear (not shown) for transmitting rotational power to the helical gear 3 . In addition, a shaft hole 4 is formed at the axial center of the flange member 10 so that the flange member is rotatively supported from the fixed side A. P/L denotes a reference plane. FIG. 15 is a cross-section of an example of a gear-equipped flange member of different shape, cut along a plane passing through its central axis. This flange member 10 has a protruding helical gear 3 at the fixed side A of a thin flange part 2 , which the helical gear 3 is smaller in diameter than the flange part 2 . A concentric shaft hole 4 is formed penetrating through the insertion part (drum engagement part) 1 , flange part 2 , and helical gear 3 .
In a case where a flange member to be pressed into a photoconductor drum is made of resin, in the prior art, the flange member is provided with an insertion part (drum engagement part) and an insertion stopping part (e.g., a flange part at which the flange member is bumped into the drum). The shape of the flange member needs to be so designed that the area of the flange member contacting the drum is large enough to avoid the situation where only the flange member rotates when force has been applied for rotating the photoconductor drum. Accordingly, the outer surface of the drum engagement part of the flange member, contacting the photoconductor drum, is designed to conform to the surface of the photoconductor drum.
Flanges of this type for photoconductor drum are disclosed for instance in Japanese Patent Application Laid-Open (JP-A) Nos. 07-13468 and 10-319782. Moreover, electrophotographic photoconductors formed using flanges are disclosed for instance in JP-A Nos. 2003-233271, 2003-241573, 2003-255759 and 2004-184452.
An image forming apparatus is generally equipped with a development device for supplying a toner-containing developer to the photoconductor drum, or a latent image bearing member, in order to visualize a latent image on the drum. Such development device systems are widely used wherein a development roller carries brush-shaped toner-containing developer particles on its surface, which are then allowed to contact a latent image on the photoconductor for visualizing the latent image.
Meanwhile, for example, in a case of a magnetic developer, a known configuration of a development roller that carries brush-shaped developer particles on its surface is that multiple magnets that serve as main magnetic poles and transfer magnetic poles are arranged in the development roller, whereby developer particles that have been transferred on the roller surface by means of the transfer magnetic poles are agglomerated into sets of particles stacked on top of each other on the roller surface by the main magnetic poles, making them in contact with the photoconductor surface.
Because the height of the stack of the particles attached to the development roller is influenced by magnetic attraction, the distance between the development roller and the photoconductor, i.e., the so-called development gap, needs to be specified for optimized conditions in which the developer is supplied to and is in contact with the photoconductor surface (see for example JP-A No. 2004-184452 for more details in this regard).
Support and rotation of the photoconductor drum are generally provided by a rotation spindle or bearings that are provided to flanges attached to both ends of the photoconductor drum, or by power supplied via gears. For this reason, these flanges need to be precisely and firmly fitted into openings at both ends of the photoconductor drum. For smooth and precise rotation of the photoconductor drum, the centers of the flanges need to be constantly held at the axis of rotation.
In order to obtain high-resolution images in an electrophotographic apparatus equipped with a photoconductor by optimizing the foregoing conditions by specifying the development distance, it is effective to manufacture a high-precision photoconductor. More specifically, it is necessary to reduce radial run-out of the photoconductor drum with respect to the flanges attached to both ends of the drum. To achieve this, it is necessary to use high-precision flanges.
However, attachment of flanges to a photoconductor is often conducted by press-fitting in combination with an additive where necessary, and thus the concentricity of the center holes of the flanges relative to the photoconductor drum surface is dependent on the manner in which they were press-fitted into the photoconductor. In this case, because of surface deviations of the press-fitted portions of the flange members from their center holes as well as of deformation of the flanges as a result of press-fitting, it has been difficult to improve concentricity of the flange center holes relative to the photoconductor drum surface.
Flanges formed by injection molding of plastic have been generally used as conventional flanges for photoconductor drum. However, there have been limitations with respect to precision in parameters of these flanges due to a variety of factors including dimensional precision of the mold used, deterioration of the mold, reproducibility of assembling the mold after disassembled for cleaning, lot-to-lot variations of resin, and molding variations. Specific characteristic values are concentricity and roundness. For continued mass production of flanges, however, there is a limitation in these values—it is required to admit a concentricity of 15 μm between the center shaft hole and drum engagement part of the flange and a roundness of 10 μm for both the shaft hole and drum engagement part. As described above, however, it is imperative to provide high-precision flanges for high-precision image formation. To achieve this, it is necessary that the molded article be subjected to a second cutting process to produce a high-precision component. Known technologies (methods and system) undesirably require a lot of skill and many steps for this.
Moreover, flanges for photoconductor drum are often equipped with a gear for transmitting driving force. In this case the mesh precision of the gear is an important characteristic value. Because of the structure of the mold, it has been difficult for flanges for photoconductor drum that are formed by injection molding to simultaneously exhibit high gear precision and high concentricity of the shaft hole relative to the drum engagement part diameter (see FIG. 15 ).
SUMMARY OF THE INVENTION
The present invention has been accomplished in order to overcome the foregoing problems, and an object of the present invention is to provide a flange with significantly improved run-out over its length that is used for a photoconductor drum, as compared to those prepared by injection molding through a conventional mold. Another object of the present invention is to provide a flange processing device and a method for processing a flange, each of which is capable of providing flanges of the same quality by making both the concentricity and roundness 0.005 mm or less. The final object of the present invention is to enable image forming apparatus to produce high-quality images.
The present invention aims to significantly increase dimensional precision of a synthetic resin flange by cutting two important portions thereof through a cutting process, which such a high dimensional precision has not been achieved only by injection molding. The flange of the present invention to be attached to a photoconductor drum includes a drum engagement part capable of being engaged with an inner surface of the photoconductor drum; and a center hole, wherein the flange is prepared by cutting at least one of a surface of the drum engagement part and an inner surface of the center hole so that the axis of the center hole coincides with the axis of the photoconductor drum. Cutting of this flange is performed without entailing re-clamping of the flange to a lathe chuck, and thereby the drum engagement part and the center hole are cut in such a way that the concentricity between the drum engagement part and the center hole is 0.005 mm or less and that the roundness of the drum engagement part is 0.005 mm or less, thereby reducing variations in the development gap and providing high-quality images.
It is preferable to form a narrow groove near the drum bumping part (flange part) so that the outer diameter of the drum engagement part (engagement diameter) is 0.1-0.5 mm smaller at the groove than at other areas of the drum engagement part. To prevent burrs on the flange from being pinched between the flange and the drum, the groove is provided near the drum bumping part so that the burrs are placed into the groove, thereby the stabilizing engagement condition. This groove or step cannot be formed with high precision only by means of injection molding, but can be formed by cutting process. The groove provided near the drum bumping part allows the flange to be attached to a photoconductor drum without any pinching of burrs at the drum end.
Moreover, the flange may be provided with a protruding part at a position opposite to the drum engagement part, which the protruding part is to be clamped to a lathe chuck upon cutting of the drum engagement part and center hole. This protruding part is provided to a flange with no gears that allows clamping of the flange to a lathe chuck. Since this flange is provided with the protruding part at its end surface, it can be clamped to the chuck even without gears. Thus cutting of the drum engagement part and center hole is made possible without re-clamping of the flange clamped to the chuck.
The flange processing device of the present invention includes: stocking means capable of housing a plurality of flanges therein; cutting means for cutting the flanges; and supplying means for supplying the flanges housed in the stocking means to the cutting means. Thereby, the flanges are transferred to the cutting means automatically and thus the injection molding step can be efficiently connected to the cutting step.
A cooling unit may be provided for blowing cooled air to the stocking means. This cooling unit for blowing cooled air to the flanges to be transferred to the cutting means can facilitate shape stabilization and thereby the flanges can be subject to cutting step in a time efficient manner.
The flange processing device of the present invention is one in which a thread-like chipping is removed by air suction from the inside of the lathe chuck at the main spindle. With this configuration, it is possible to remove chipping generated as a result of cutting of center hole and to prevent the chipping from being entwined with the bite.
The method of the present invention for processing a flange is one for processing a flange which include a drum engagement part capable of being engaged with an inner surface of a photoconductor drum and a center hole and which is to be attached to an end of the photoconductor drum, wherein in a state where a flange provided with a gear part is clamped to a lathe chuck at the gear part, at least one of a surface of the drum engagement part and an inner surface of the center hole is cut. By cutting the drum engagement part (shaft hole) and center hole in a state where the gear part is clamped to the lathe chuck, it is possible to reduce the pitch error over total teeth (i.e., it is possible to improve gear precision). Upon cutting of a flange provided with a protruding part, cutting of the drum engagement part and center hole is performed with the protruding part being clamped to the lathe chuck. In this way the drum engagement part and center hole can be cut with high precision. In the foregoing flange processing method, it is preferable to adopt an air balloon chuck in order to clamp a flange to the lathe chuck with a low pressure. Alternatively, a diaphragm chuck may be used in order to clamp a flange with a low pressure just as the air balloon chuck can. In this case, similar effects can be obtained. More specifically, the use of such a diaphragm chuck enables flange clamping at a pressure low enough to avoid deformation of the flange. Furthermore, the number of jaws provided to the lathe chuck is preferably 6 to 8. This prevents flange deformation to a greater extent.
It is preferable during cutting process to remove a thread-like is chipping by air suction from the inside of the lathe chuck. In addition, it is preferable that the bite enter the flange at an angle of 3° to 45° for the cutting of the center hole. By doing so it is possible to prevent generation of burrs at the initial stage of cutting. It is also preferable that the bite withdraw out of the flange at an angle of 3° to 45° for the cutting of the center hole. By doing so it is possible to prevent generation of burrs at the final stage of cutting. Furthermore, it is preferable to set cutting depth to 0.05-3 mm. This allows chippings to be linked together into a thread-like chipping which can be readily removed.
In the flange processing method, during the cutting process, a feedback control is established in which the work temperature is measured and cutting depth is changed according to the linear expansion coefficient of resin used. By this feedback control mechanism, the processed flanges have the same dimension even when room temperature and the flange surface temperature varied during the cutting process.
According to the present invention, it is possible to manufacture a high-precision flange for photoconductor drum without fail, and to provide a high-quality photoconductor drum attached to a flange that has significantly improved run-out over its length as compared to those prepared by injection molding through a conventional mold.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 shows a schematic perspective view showing an appearance of a flange of the present invention prior to cutting process.
FIG. 2 is an enlarged cross-sectional view of the flange of FIG. 1 after cutting process, which is provided with a groove at the bottom of the drum bumping part thereof.
FIG. 3 is a schematic perspective view showing an appearance of another flange of the present invention prior to cutting process.
FIG. 4 is a schematic perspective view showing an example of the shape (prior to cutting process) of a gear-free flange of the present invention, which is provided with a protruding part.
FIG. 5 is a perspective view showing a system configuration of a flange processing device (system) according to the present invention.
FIG. 6 is a schematic view showing a configuration for removing a thread-like chipping by air suction at the spindle of the lathe.
FIG. 7 is a schematic view showing an example of a device for uniformly blowing cooled air to a stacker.
FIG. 8 is a schematic diagram for explaining a pattern in which the bite moves upon cutting of the center shaft hole.
FIG. 9 is another schematic diagram for explaining a pattern in which the bite moves upon cutting of the center shaft hole.
FIG. 10 shows data obtained after cutting process.
FIG. 11 shows concentricity and roundness values for an article processed by a processing device according to an embodiment of the present invention, which are measured by a roundness analyzer made by TOKYO SEIMITSU.
FIG. 12 shows processing results obtained using diaphragm chucks other than a 6-jaw diaphragm chuck.
FIG. 13 shows variations in outer diameter of flange when room temperature varied from 22° C. to 27° C.
FIG. 14 is a cross-sectional view of an example of a gear-attached flange, including its center axis.
FIG. 15 is a cross-sectional view of another example of a gear-attached flange, including its center axis.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Hereinafter an embodiment of the present invention will be described with reference to the drawings. FIG. 1 shows a schematic perspective view showing an appearance of a flange (member) 10 A of the present invention prior to cutting process. FIG. 2 is an enlarged cross-sectional view of the flange 10 A of FIG. 1 after cutting process, which is provided with a groove 7 at the bottom of the drum bumping part 2 thereof. FIG. 3 is a schematic perspective view showing an appearance of another flange 10 B of the present invention prior to cutting process. FIG. 4 is a schematic perspective view showing an example of the shape (prior to cutting process) of a gear-free flange 10 C of the present invention, which is provided with a protruding part 5 b . FIG. 5 is a perspective view showing a system configuration of a flange processing device (system) according to the present invention.
A flange 10 A shown in FIG. 1 is a two-staged substantially cylindrical member formed by injection molding of synthetic resin. The flange 10 A is cut on a lathe or the like to give a shape shown in FIG. 2 . One end surface 5 a of a large diameter-main cylinder 5 includes a protruding part 5 b that after cutting serves as a drum engagement part 1 to be fitted into the inner circumference of a photoconductor drum end (not shown). At the center of the other end surface 5 c of the main cylinder 5 , having a circular end, has a protruding helical gear 3 and protruding shaft cylinder 6 to be a shaft portion, both of which are smaller in diameter than the main cylinder 5 . The center hole 6 a in the shaft cylinder 6 communicates with the shaft hole 4 . As shown in FIG. 2 , the drum engagement part 1 is cut to have a predetermined outer diameter in such a way that it is coaxial with the helical gear 3 . As shown in the cross-sectional view of FIG. 2 , a narrow groove 7 is formed in the vicinity of the drum bumping part (flange part) 2 of the flange 10 A so that the diameter of the drum engagement part 1 (engagement diameter) is 0.1-0.5 mm smaller at the groove 7 than at other areas of the drum engagement part 1 . The center hole part 6 a of the cylindrical shaft portion 6 provided at the center of the flange is processed to form a shaft hole 4 that is coaxial with the drum engagement part 1 and helical gear 3 .
A flange 10 B shown in FIG. 3 is also a substantially cylindrical member formed by injection molding of synthetic resin. The flange 10 B is cut on a lathe or the like to form a protruding part 5 b at one end surface 5 a of the main cylinder 5 , which the protruding part 5 b becomes a drum engagement part 1 to be fitted into the inner circumference of a photoconductor drum end. In the flange 10 B shown in FIG. 3 , the other end surface of the main cylinder 5 is processed to be a helical gear 3 . In a subsequent process, the drum engagement part 1 is cut so as to be coaxial with the helical gear 3 . A narrow groove (step) 7 is formed in the vicinity of the drum bumping part (flange part including the helical gear 3 ) 2 of the flange 10 B so that the diameter of the drum engagement part 1 (engagement diameter) is 0.1-0.5 mm smaller at the groove 7 than at other areas of the drum engagement part 1 . The center hole part at the center of the flange is processed to form a shaft hole 4 that is coaxial with the drum engagement part 1 and helical gear 3 .
A flange 10 C of the present invention shown in FIG. 4 (prior to cutting process) is a flange that does not have a gear, and is a member formed by injection molding of synthetic resin as are the foregoing flanges 10 A and 10 B. The flange 10 C is cut on a lathe or the like to form a protruding part 5 b at one end surface 5 a of the main cylinder 5 , which the protruding part 5 b becomes a drum engagement part 1 to be fitted into the inner circumference of a photoconductor drum end. At the center of the other end surface 5 c of the main cylinder 5 , there is provided a protruding protruding part 8 (for chucking) that is smaller in diameter than the main cylinder 5 , forming a two-staged substantially cylindrical member. At the inner side of the protruding part 8 , a protruding shaft cylinder 6 is formed that becomes a shaft portion. The center hole part of the cylindrical shaft portion 6 provided at the center of the flange is processed to form a shaft hole 4 that is coaxial with the drum engagement part 1 and helical gear 3 . The drum engagement part 1 is cut to have a predetermined outer diameter and, as in the case of FIG. 2 , in the vicinity of the drum bumping part (flange part) 2 thereof, there is provided a narrow groove 7 so that the diameter of the drum engagement part 1 (engagement diameter) is 0.1-0.5 mm smaller at the groove 7 than at other areas of the drum engagement part 1 .
Because of their specific structures these flanges 10 A, 10 B and 10 C can achieve the concentricity of 0.005 mm or less and roundness of 0.005 mm or less much easier than conventional flanges. This is achieved by setting the inner and outer diameters of the drum engagement part and center hole to predetermined values through a cutting process in which the flange is clamped to the lathe chuck only once (i.e., without re-clamping the flange to the chuck).
In particular, the use of a processing device to be described later and a cutting process in accordance with a processing method to be described later can, without fail, ensure that both the concentricity and roundness are 0.005 mm or less without re-clamping of the flange to be processed.
A flange processing device (system) shown in FIG. 5 , which is suitable for cutting of the flanges, will be described below. The flange processing device 100 shown in FIG. 5 is composed primarily of a lathe 50 , a cutting machine to be described later in detail. A stacker 70 can be attached to the flange processing device 100 for increasing overall operational efficiency in conjunction with an injection molding machine 60 . To be more specific, a stacker 70 for transferring flanges is attached to the flange processing device 100 so that flanges formed by injection molding can be readily supplied to the cutting machine. The stacker 70 is provided with trays 71 for storing flanges prepared using the injection molding machine 60 , and is connected to the side of the lathe 50 (hereinafter may be referred to as a “cutting machine”). In this way flanges can be automatically supplied from the tray 71 to the chuck 51 of the cutting machine 50 by means of a (flange member) supplier 72 .
An air blower 80 is incorporated into the flange processing system 100 so that the stacker 70 can function effectively. Injection molded flanges exhibit shrinkage right after their preparation and thus generally need to be left stand for a long period of time before their shapes are stabilized. However, it is necessary that full shrinkage be accomplished in the shortest time for synchronized operation with the cutting machine. To stabilize the shapes of flanges stored in the stacker 70 as early as possible, the air blower 80 (see FIG. 7 ) is incorporated into the flange processing system 100 as a cooling device for blowing cooled air to the flanges in the stacker 70 .
As described above, it succeeded in stabilizing the flange shapes by facilitating their shrinkage by using such an air blower. For increased heat efficiency, a stainless steel shield is wrapped around the stacker 70 . This cooling method can facilitate cooling of flanges at low costs, however, for a shorter flange shape stabilization time, another method may be adopted wherein a refrigerator is used that can accommodate the entire stacker.
The lathe 50 uses a 6-jaw diaphragm chuck as the chuck 51 that can be attached to the rotational spindle. This is because there is a concern of causing deformation of the flange due to the strain of clamping force when it is clamped to the chuck by means of normal air or oil pressure upon cutting of portions near the chuck. The use of the diaphragm chuck 51 enables flange clamping at a pressure low enough to avoid deformation of the flange. By controlling the pressure applied to the diaphragm chuck 51 , it is possible to achieve delicate cutting condition changes in a case where the shape of a non-processed injection molded article has changed from the previous one. Note that a similar effect can be obtained even when an air balloon chuck is used as the chuck for the lathe 50 .
The lathe 50 has a function of removing a thread-like chipping (cutting) by air suction at the spindle 52 . To be more specific, for the purpose of removing chippings during the cutting process, the lathe 50 has a hollow at the spindle through which a suction device (not shown) is connected to the lathe 50 for suctioning chippings by air from inside the spindle 52 . To realize this configuration it is necessary to ensure that cutting depth falls within a proper range (0.05-0.3 mm) during the actual cutting process so that chippings can be readily removed in the form of a thread-like chipping rather than separate chipping pieces. Note that the chipping suction configuration is not particularly limited to the above-noted configuration.
An example of a cutting operation will be described specifically below. A gear-equipped flange which is formed by injection molding of resin and has a shape shown in FIG. 1 is attached to the lathe by clamping it to the 6-jaw chuck at the outer surface of the gear part provided at the end of the flange.
Cutting is performed first for the drum engagement part of the flange. Although a proper cutting depth to form a thread-like chipping differs depending on the material, a cutting depth is preferably about 0.15 mm in the case of general polycarbonate. A groove is provided at the drum bumping part of the flange (see FIG. 2 ). The groove is about 0.1-05 mm in depth and the depth can be appropriately set according to the finish of the drum end. It was confirmed that a groove of 0.2 mm depth can avoid influences of burrs and warpage at the drum end.
With the configuration shown in FIG. 6 , a thread-like chipping is removed by air suction at the spindle of the lathe upon cutting of a shaft hole. For forming a thread-like chipping, the cutting depth is set to about 0.15 mm in the case where the flange is made of polycarbonate. An optimal cutting depth is selected depending on the material. During the cutting of a shaft hole, a thread-like chipping is removed together with other chipping pieces by air suction without any tangle of the thread-like chipping. To avoid generation of burrs at the end of the resultant shaft hole of the flange, which are created as a result of entry of the bite 53 (cutting tool) into the flange shaft core, it is preferable to change the angle at which the bite 53 enters the flange. FIG. 8 shows a pattern in which the bite 53 moves upon cutting of the shaft hole. With this cutting method, it is possible to avoid generation of burrs during entry of the bite 53 . Furthermore, in order to avoid generation of burrs that are generated by withdrawal of the bite 53 , it is preferable to change the angle in which the bite 53 withdraws out of the flange. FIG. 9 shows a pattern in which the bite 53 withdraws out of the flange during cutting the shaft hole. With this cutting method, it is possible to avoid generation of burrs during withdrawal of the bite 53 . For example, a cutting process adopting a bite entry angle of 30° and a bite withdrawal angle of 35° gave good results.
By cutting the drum engagement part and shaft hole part while clamping the outer surface of the gear part of the flange to the chuck, it succeeded in obtaining low concentricity between the resultant shaft hole and drum engagement part and excellent roundness. FIG. 11 shows obtained concentricity and roundness values measured by a roundness analyzer made by TOKYO SEIMITSU.
A 6-jaw diaphragm chuck was adopted, and it succeeded in achieving precisions shown in FIG. 11 in mass production of flanges with this chuck. However, the number of jaws may be 6 or more. Pre-evaluations were made with respect to a 3-jaw diaphragm chuck and an 8-jaw diaphragm chuck, and evaluation results are shown in FIG. 12 . In the case of the 3-jaw diaphragm chuck, there was a tendency that the cross-sectional shape of the processed flange. In order to ensure excellent cutting results, it is preferable that the number of jaws is 6 or more.
FIG. 10 shows cutting process data with different pressures (0-0.6 Mpa) applied to the diaphragm chuck. Pressure control can realize delicate cutting condition changes in a case where the shape of a non-processed injection molded article has changed from the previous one.
An air balloon chuck may be used as a chuck for clamping a flange to the lathe chuck, in order to clamp the flange with a low pressure as in the case of a diaphragm chuck. The air balloon chuck can provide the same effect as the diaphragm chuck.
Flange temperature changes during the actual cutting process causes flange expansion or shrinkage, and hence the cutting amount changes. FIG. 13 shows variations in outer diameter of flange when room temperature varied from 22° C. to 27° C. As shown in FIG. 13 , since the outer diameter of flange changes with the temperature, the processing device according to the embodiment is so configured that the variations in dimension among identical flanges can be minimized by controlling the degree of entry of the bite in the flange by feedback control according to the temperature change. For reference temperature data for this feedback control, either work surface temperature or room temperature is selected depending on the circumstances. Note, however, that if the room temperature change can be within about ±2° C. during the course of the cutting process, the effect of this feedback control is little and, since the cutting depth is preferably constant, in actual, room temperature-based control may be selected.
Although the descriptions given above are directed to the cutting process for the flange shown in FIG. 1 , the flange shown in FIG. 3 can be processed with high precision in much the same way by clamping the outer surface of the gear part of the protruding part of the flange. The flange shown in FIG. 4 formed by injection molding of resin is attached to the lathe 50 by clamping the protruding part 8 , which is provided to its end, to the 6-jaw chuck 51 . High-precision cutting of the drum engagement part 1 and center hole (shaft hole) 4 is made possible by performing cutting with the protruding part 8 being clamped to the lathe chuck only for once.
The present invention can be widely applied to substantially cylindrical mechanical components such as rollers that include plastic flanges attached at either end thereof, whereby roundness and concentricity are improved to increase rotation performance of the components.
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To provide a flange to be attached to an end of a photoconductor drum, the flange including: a drum engagement part capable of being engaged with an inner surface of the photoconductor drum; and a center hole, wherein the flange is prepared by cutting at least one of a surface of the engagement part and an inner surface of the center hole so that the axis of the center hole coincides with the axis of the photoconductor drum.
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BACKGROUND OF THE INVENTION
[0001] The invention relates to a hinged-lid box for cigarettes or cigarette packs, comprising a single-piece package blank made of (thin) cardboard for the purpose of forming a box part with box front wall, box rear wall, box side walls and a lid having lid front wall, lid rear wall and lid side walls, it being possible during the finishing process of the hinge-lid box to fold a collar, which is connected as a single piece to one side of the package blank, against an inner side of the package blank.
[0002] Such blanks are usually processed according to the transverse enveloping principle.
BRIEF SUMMARY OF THE INVENTION
[0003] The invention is based on the object of further developing and improving the aforementioned hinge-lid box, thus making it possible to manufacture hinge-lid boxes on high-performance packaging machines.
[0004] To achieve this object, the hinge-lid box according to the invention, or a blank for its manufacture, is characterized by the following features:
a) the package blank forms successive or continuous regions for an outer box side tab and lid side tab, box front wall and lid front wall, box side wall and lid side wall, box rear wall and lid rear wall, as well as marginal connective strips for connecting opposite marginal side tabs, b) the collar is attached to a free edge of the side tab.
[0007] During the production of the hinge-lid box, a first folding step involves folding the collar into the correct package position abutting the side tabs, the box front wall and the box side wall. The blank can now be folded around the package contents, with the (centered) box side wall with lid side wall being placed on a narrow side of the object to be wrapped and which can also be further processed by making U-folds.
[0008] The collar as part of the overall blank has a special configuration, specifically concerning the course of a top collar edge with respect to the relative position to the package blank and its dimensions.
[0009] Hinge-lid boxes made from the blank according to the invention are particularly advantageous for use as a suitable multipack for cigarettes, i.e. for accommodating a group of cigarette packs. One special feature is that by virtue of the sizing of the blank and the resulting hinge-lid box, a group of five adjacent cigarette packs are arranged in an upright position within the hinge-lid box. In addition, it is possible to connect two thusly formed multipack hinge-lid boxes to form a divisible or detachable unit, with the base walls of the hinge-lid boxes lying against one another, which can be detachably connected by means of adhesive tabs or the like, for example. According to a further special feature, the cigarette packs are arranged in the hinge-lid box, which is designed to give the impression of a multipack, by being stacked on top of one another and arranged with their large-surface pack sides facing one another, in particular with rear wall facing front wall.
BRIEF DESCRIPTION OF THE DRAWINGS
[0010] Further special features of the hinge-lid box and blank according to the invention will be discussed in more detail below with the help of the drawings, which show:
[0011] FIG. 1 is a perspective view of a hinge-lid box in its closed position.
[0012] FIG. 2 is the package according to FIG. 1 with the lid in an open position.
[0013] FIG. 3 shows a laid-open blank, namely the complete blank for a hinge-lid box according to FIG. 1 and FIG. 2 .
[0014] FIG. 4 shows the blank, or complete blank, according to FIG. 3 in an intermediate folding position.
[0015] FIG. 5 shows a side view of the hinge-lid box with closed lid.
[0016] FIG. 6 shows a perspective view of a different embodiment of a hinged-lid box or multipack with open lid.
[0017] FIG. 7 shows a modified blank for a hinge-lid box (element) of the multipack according to FIG. 6 , in laid-out position.
[0018] FIG. 8 shows a perspective view of another embodiment of a hinge-lid box as a multipack for cigarettes.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0019] The exemplary embodiments shown in the drawings are hinge-lid boxes for accommodating a group of packs, namely cigarette packs 10 . These are also hinge-lid packages whose embodiment is basically known. The group is arranged in a large-volume multipack configured as a hinge-lid package. The positioning of the cigarette packs 10 in the exemplary embodiment according to FIG. 1 and FIG. 2 is made as two pack groups 11 , 12 arranged one above the other. The cigarette packs 10 within the pack groups 11 , 12 are positioned next to each other in a row and aligned one above the other such that two cigarette pack 10 each are arranged exactly one above the other, with a total of ten cigarette packs 10 . The pack contents formed in this manner completely fills the multipack, or hinge-lid box.
[0020] The hinge-lid box is comprised, in conventional manner, of a lower box part 13 and an (upper) lid 14 . Disposed within the hinge-lid box is a collar 15 , which is seated within the box part 13 with a predominant, lower section. An upper collar head 16 which projects above the box part 13 is surrounded by the lid 14 when the box is closed.
[0021] The overall hinge-lid box comprises a single-piece blank, namely a complete blank pursuant to FIG. 3 . As part of the complete blank, a package blank 17 forms mutually delimited blank regions by means of embossed lines, namely—following one another in the transverse direction—a marginal box side tab 18 with lid side tab 19 joining it at the top. Adjacent thereto is a box front wall 20 with a connected lid front wall 21 . Following in the transverse direction is a box side wall 22 with lid side wall 23 . Connected thereto are box rear wall 24 and lid rear wall 25 . Located at the free edge of the box rear wall 24 is a box strip 26 with a corresponding lid strip 27 . The projecting walls of the box part 13 , on one hand, and the lid 14 , on the other hand, are delimited from one another in the region of the front wall and side walls by means of a punched line 28 , which has a plurality of residual connections 29 , 30 of the material for the purpose of creating a connection between the lid 14 and box part 13 before the lid 14 is opened for the first time. Formed in the region of the box front wall 20 and lid front wall 21 are two residual connections 29 located at a distance from one another, while a centered residual connection 30 is formed in each region of box side tab 18 and box side wall 22 . The residual connections 29 , 30 are severed when the lid 14 is opened for the first time. The box rear wall 24 and lid rear wall 25 are delimited from each other by a hinged line 31 which is configured as a punched line in some of its regions. The punched line 28 runs in the region of the box side tab 18 and in the region of the box side wall 22 in an oblique downward direction to a transverse section of the punched line 28 in the region of the box front wall 20 . Formed in the middle of the box front wall 20 at the lower side of the punched line 28 is an orifice 32 which is delimited in a semicircular shape and which facilitates the opening of the hinge-lid box when it is used for the first time.
[0022] An upper end wall 33 of the lid 14 and a lower base wall 34 of the box part 13 each comprise a plurality of folding tabs folded over one another which are arranged in the extension of the walls 19 , 21 , 23 , 25 and the walls 18 , 20 , 22 and 24 , respectively. Arranged in the region of box side tabs 18 and lid side tab 19 as well as in the region of the box side wall 22 and the lid side wall 23 are trapezoid-shaped corner tabs, which in the finished hinge-lid box lie on the inner side of end wall 33 and base wall 34 . An essentially rectangular inner tab 37 is attached in the region of the box front wall 20 and in the region of the lid front wall 21 . This inner tab 37 is slightly smaller than the surface area of end wall 33 and base wall 34 . The inner tab 37 lies on the outer side of the corner tabs 35 , 36 . Outer corner tabs 38 are arranged in the region of box rear wall 24 and lid rear wall 25 . The cover tabs 38 form the outer side or outer layer of end wall 33 and base wall 34 .
[0023] The respective cover tabs 38 correspond exactly in size and contour to the end wall 33 and base wall 34 .
[0024] One special feature is the positioning of the collar 15 as part of the complete blank. The collar 15 is attached to the box side tab 18 , specifically with one of two collar flaps 39 , 40 . The collar flap 40 is connected to a free edge of the box side tab 18 by means of a folding line 41 . The folding line 41 is formed by punching and partial cuts that allow for easy non-stressed folding.
[0025] The collar 15 has in the region of a central collar front wall 42 a conventional center depression 43 that is bordered by an upper collar edge 44 . Proceeding from each collar corner 45 the collar edge 44 extends downwards at an oblique angle, specifically as a continuation of the oblique course across the two collar flaps 39 , 40 . In the region of the box side tab 18 the collar edge 44 precisely meets the end of the punched line 28 , but at a slightly different angle.
[0026] In a first folding step during the production of the hinge-lid box, the collar 15 is folded at the folding line 41 until it lies on the inner side of the package blank 17 ( FIG. 4 ). In the process, the collar flap 40 lies on the inner side of the box side tab 18 . This first folding step is preferably already executed during the production of the blank in a paper or paper board manufacturing plant, so that, in terms of the collar 15 , prepared, partially-folded blanks for further processing can be delivered. The collar front wall 42 covers a part of the box front wall 20 and the lid front wall 21 . In addition, the collar flap 39 lies on the box side wall 22 . In this folded position the collar 15 is merely connected to the package blank 17 in the region of the box side tab 18 , namely by means of (two) glue beads 46 . This first folding step is expediently executed by the manufacturer of the blanks, so that blanks in the shape shown in FIG. 4 are delivered and fed to the packer.
[0027] The blank can now be folded around the block-shaped package contents, expediently by laying the box side wall 22 and lid side wall 23 on the package contents and folding the rest of the blank in a U-shaped manner. In order to complete a sleeve-like intermediate folding position, the box strips 26 are connected to the free side of the collar flap 40 by adhesive bonding.
[0028] Correspondingly, the lid strip 27 separated from the box strip 26 is likewise connected by adhesive bonding to the inner side of the lid side tab 19 . Afterwards the folding tabs for forming the end wall 33 and base wall 34 are folded and joined to each other by adhesive bonding.
[0029] By virtue of the course of the punched line 28 , on one hand, and the contours of the collar 15 , in particular the collar edge 44 , on the other hand, the collar edge 44 in the region of the box side tab 18 and in the region of the box side wall 22 runs from the front side of the hinge-lid box to its rear side in a oblique downward direction, while a closing edge formed by the punched line 28 assumes an oblique upward direction from the front side to the rear side. Collar edge 44 and closing edge, or punched line, 28 converge at an acute angle and meet at a contact point 48 at the rear side.
[0030] Due to the package construction outlined above, box strip 26 and lid strip 27 are separated from each other by a wedge-shaped cutout 49 at the height of the hinged line 31 . This results in obliquely directed edges of the box strip 26 and lid strip 27 corresponding to the course of the closing edge and collar edge 44 ( FIG. 5 ). The angle defined by the cutout 49 is somewhat greater than the angle defined by the collar edge 44 and closing edge in the region of the package sides, with the result that the oblique edges of the box strip 27 and lid strip 27 bordering the cutout 49 are not visible from the exterior ( FIG. 5 ).
[0031] A special feature is the design of the hinge-lid box with round package edges 50 , 51 in the region of the box part 13 and lid 14 as well as in the region of the collar 15 . The rounding of the package edges 50 , 51 has in particular been sized to conform to the dimensions of the package contents in this region, in particular to the rounded shape of cigarettes—for cigarette pack 10 —or to the rounded contours of cigarette packs 10 with round corners ( FIG. 2 ). However, the roundings of the package edges 50 , 51 can also exhibit a greater radius. The collar 15 being then so configured that after the first folding step ( FIG. 4 ), round edges 52 , 53 of the collar 15 lie precisely on the associated package edges 50 , 51 of the box front wall 20 . In addition, the collar 15 is configured namely with respect to the course of the collar edge 44 such that the contact point 48 lies outside the region of the round package edges 50 , 51 ( FIG. 5 ). Furthermore, due to punchings 54 , the resulting configuration of the inside folding tabs of end wall 33 and base wall 34 is such that their formation lies outside the region of the round package edges 50 , 51 .
[0032] Analogously, the package can also be designed with oblique edges, i.e. with beveled package edges, resulting in an package having an octagonal cross section.
[0033] In a multipack for two pack groups 11 , 12 arranged one above the other, the collar 15 is dimensioned such that a lower edge 55 extends at a slight distance above the base wall 34 . The collar 15 has been dimensioned such that the cigarette packs 10 of both pack groups 11 , 12 are provided with stable support. This means that the collar 15 extends at least to a point below the middle of the cigarette packs 10 of the lower pack group 12 .
[0034] A special feature is shown in FIG. 6 and FIG. 7 . A multipack designed as a hinge-lid pack is comprised of two sub-packages 56 , 57 . Each of these sup-packages 56 , 57 is a hinge-lid box having the features of the exemplary embodiment pursuant to FIG. 1 to FIG. 5 . The only difference is in the dimensions of the blank and thus of the hinge-lid box or sub-package 56 , 57 . For each sub-package 56 , 57 is dimensioned such that a pack group 11 or 12 of five cigarette packs 10 can be accommodated in a sub-package 56 , 57 . Here the cigarette packs 10 are ordered in the same manner as the pack groups in the hinge-lid box pursuant to FIG. 2 , i.e. positioned upright and occupying the complete volume of the package. In this exemplary embodiment a collar 15 also extends to the immediate region of a base wall, with the result that collar front wall 42 and collar flaps 39 , 40 support the (individual) pack group 11 , 12 across practically its complete height.
[0035] In FIG. 6 , two such sub-packages 56 , 57 have been consolidated to form a multipack unit. To this end, two sub-packages 56 , 57 of matching configuration lie with their base walls 34 against one another. In this region the sub-packages 56 , 57 are (detachably) connected to one another. The shown exemplary embodiment has in each region of adjacent narrow side walls a connecting element, namely an adhesive label 58 with a weakening line, namely a perforation line 59 in the region of the abutting base walls 34 . The unit shown in FIG. 6 can be divided by the dealer or consumer by severing the perforation line 59 .
[0036] The arrangement of the sub-packages 56 , 57 has been chosen in order that they are laterally reversed, i.e. with each box front wall 20 of the one sub-package 56 being on the same side as the box rear wall 24 of the other sub-package 57 .
[0037] Another special feature is shown in FIG. 8 . There too a hinge-lid box—whose cross-section exhibits right-angle pack corners—is configured as a multipack for a number of cigarette packs 10 . The special feature here is the arrangement of the cigarette packs 10 within the hinge-lid box. These are positioned in the hinge-lid box with their large-surface pack sides, namely with front side and rear side, facing each other. Their plan view dimension has been chosen to correspond to the front or rear side of a standard cigarette pack 10 . The height of the hinge-lid box corresponds to the number of cigarette packs 10 lying flat and arranged one above the other; in the exemplary embodiment pursuant to FIG. 8 this is the height of five cigarette packs 10 .
List of Designations
[0000]
10 cigarette pack 41 folding line
11 pack group 42 collar front wall
12 pack group 43 depression
13 box part 44 collar edge
14 lid 45 collar corner
15 collar 46 glue bead
16 collar head 48 contact point
17 package blank 49 cutout
18 box side tab 50 package edge
19 lid side tab 51 package edge
20 box front wall 52 round edge
21 lid front wall 53 round edge
22 box side wall 54 punching
23 lid side wall 55 lower edge
24 box rear wall 56 sub-package
25 lid rear wall 57 sub-package
26 box strip 58 adhesive label
27 lid strip 59 perforation line
28 punched line
29 residual connection
30 residual connection
31 hinged line
32 orifice
33 end wall
34 base wall
35 cornertab
36 cornertab
37 innertab
38 covertab
39 collar flap
40 collar flap
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Employed in the manufacture of (cigarette) packs of the hinge-lid type, preferably as a multipack, is a blank comprising a main package blank ( 17 ) and a collar ( 15 ) connected thereto as a single piece. A resulting complete blank is processed according to the transverse enveloping principle. The collar ( 15 ) is connected to the package blank ( 17 ) by means of a marginal folding line ( 41 ) in the region of an outer box side tab ( 18 ).
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FIELD OF THE INVENTION
[0001] The present invention is generally directed toward accelerating the healing process after damage to the intestinal tract. More particularly, the invention is directed to an apparatus for treatment of an enterocutaneous fistula.
BACKGROUND OF THE INVENTION
[0002] Stab wounds, gun shot wounds and surgical complications can result in an abnormal connection between the intestines and skin through which bowel contents may pass. This abnormal passage connecting the intestine to the skin is known as an enterocutaneous fistula (ECF). Ordinarily, these fistulas can be closed immediately after the stab wound, gunshot wound or surgical injury takes place without the occurrence of chronic ECF. However, sometimes associated injuries, severe life-threatening bleeding, or shock from blood loss or inadequate blood supply impair healing of intestinal wounds and ECF occurs many days or weeks after the initial injury.
[0003] Enterocutaneous fistulas present a major medical problem because they allow contents of the digestive system to leak out onto the skin. These small bowel contents include liquefied food as well as digestive enzymes and alkali which are caustic to the skin. Because the body produces large amounts of digestive fluids to digest food, more liquid escapes through the fistula than is ingested. Not only does the fistula result in damage to the skin and reduced gastrointestinal functionality, it also causes significant hygiene problems. The patient is unable to function normally until the drainage has been markedly reduced.
[0004] The occurrence of ECF weeks after initial injury may not be readily repaired surgically because of other life-threatening conditions such as inadequate blood clots, infection elsewhere in the body, or severe scar tissue or inflammation in the abdominal cavity. The marked inflammation and scarring that can occur after abdominal surgery can make any follow-up surgery difficult. The bowel wall can either become very thin and fragile, or it can become very thick and swollen. Either condition makes re-operation and immediate re-repair difficult, dangerous or impossible. Attempted re-operation can result in additional holes in the intestine which then must also be repaired. These holes may also break down, causing additional ECFs.
[0005] Currently, surgical repair of enterocutaneous fistula is a difficult procedure, involving a dangerous operation with the risk of causing additional fistulas. The current therapy is most simply described as keeping the patient alive until the body heals the fistula itself or until major surgery can be attempted.
[0006] Several steps may be taken to keep the patient alive and to reduce any discomfort. Total parenteral nutrition, the practice of providing nutrition in liquid form intravenously, could be used to bypass the normal digestive tract. This meets the patient's nutritional needs and thereby reduces the amount of fluid coming out of the ECF onto the skin.
[0007] Medication, such as somatostatin, may also be used to reduce bowel activity, resulting in lower ECF output. Additionally, the same apparatus used to cover colostomies could be used to cover the ECF openings to capture the ECF drainage to prevent skin damage and make life more comfortable for the patient. The wound can also be kept clean with the use of dressings.
[0008] The medical costs and financial burdens using the current enterocutaneous fistula treatments are huge. While the patient is in the hospital, costs can surpass $5,000 per day, and hospital stays may last for months. After leaving the hospital, most patients require total parenteral nutrition. This process can easily cost hundreds of dollars per day.
[0009] Furthermore, these measures do not properly address the release of intestinal fluids onto the skin. There is an important need for a device that can prevent the contents of the bowel from escaping through a fistula until the damage to the intestines can be properly treated.
SUMMARY OF THE INVENTION
[0010] The present invention is a prosthetic device that may be inserted between the healthy ends of the intestine surrounding the enterocutaneous fistula, effectively bridging the discontinuity in the intestines. The prosthetic device would allow contents of the intestinal tract to pass through the bowels without leaking out. It would allow the patient to intake food normally and not require total parenteral nutrition for extended periods. The prosthetic device includes means for securing the device within the intestines and preventing digestive fluids from escaping from the intestinal tract. Additionally, the device may include means to simulate peristalsis thereby pushing bowel contents into the undamaged portion of the intestine. The prosthetic device may also include unidirectional valves to prevent contents from moving backward through the digestive tract.
[0011] Using the invention described herein, a patient suffering from an enterocutaneous fistula may recover sooner without extensive hospital stays.
BRIEF DESCRIPTION OF THE DRAWINGS
[0012] Further advantages of the invention will become apparent by reference to the detailed description of preferred embodiments when considered in conjunction with the drawings, which are not to scale, wherein like reference characters designate like or similar elements to the several drawings as follows:
[0013] FIG. 1 depicts an embodiment of the invention.
[0014] FIG. 2 depicts another view of an embodiment of the invention.
[0015] FIG. 3 depicts an embodiment of the invention including an expandable inner member.
[0016] FIG. 4 depicts another view of an embodiment of the invention including an expandable inner member
[0017] FIG. 5 depicts an embodiment of the invention including an expandable inner member and unidirectional valves.
[0018] FIG. 6 depicts another view of an embodiment of the invention including an expandable inner member and unidirectional valves.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0019] In one embodiment of the invention, depicted in FIG. 1 and FIG. 2 , the prosthetic device consists of an elongated tube 1 which bridges both disconnected ends of the intestine. It includes means for securing the device into the small intestine and forming a seal such that bowel contents cannot seep around the prosthetic device. In the current embodiment, the seals are formed by means of inflatable cuffs 2 which encircle the elongated tube 1 and are located at both ends of the prosthetic device. The inflatable cuffs 2 may be inflated by passing air through inflation tubes 3 that may be connected to an air pressure source such as a syringe or air pump (not shown). The inflation tubes 3 may include valves that prevent air from escaping the inflatable cuffs 2 .
[0020] Elongated tube 1 may be constructed of any biocompatible material. Preferably, the elongated tube 1 is constructed of a mildly deformable material such as silicone rubber latex, vinyl tubing, or a thermoplastic elastomer.
[0021] Tubing with an inflatable cuff, such as that found on Emergency Medicine Tubes manufactured by MALLICKRODT for insertion into the trachea, may be used at the ends of the prosthetic device. Such tubing consists of a vinyl tubing with inflatable cuffs and inflation tubes. Tubing with a single inflatable cuff has previously been disclosed in U.S. Pat. No. 4,387,711 to Merry. The tubing with the inflatable cuff may be connected to the elongated tube 1 , or it may be one continuous piece. Pushing air or any gas into the inflatable cuffs 2 through inflation tubes 3 will result in expansion of the ends of the prosthetic device such that it forms a seal against the inner walls of the ends of the intestine. The seal prevents bowel contents from bypassing the prosthetic device. Other means to seal the prosthetic device against the inner walls of the intestine that are also known in the art may be used.
[0022] The claimed invention may optionally include means for promoting the motion of intestinal contents through the prosthetic device. In the pictured embodiment of FIG. 3 . and FIG. 4 , an expandable inner member 4 is present within the lumen of elongated tube 1 . Inner member 4 is connected to an air pump via inner member inflation tube 5 . This inner member inflation tube 5 passes through a small hole in the wall of elongated tube 1 . The area around the hole may be sealed to prevent any intestinal fluids from escaping. The air pump can push air into or suction air from expandable inner member 4 . Pushing air causes the expandable inner member 4 to inflate, expelling the bowel contents from the lumen of the prosthetic device.
[0023] The pump may then operate in reverse causing air to be suctioned out of the expandable inner member 4 such that the expandable inner member 4 contracts. The deflation and resulting contraction of the expandable inner member 4 allows more bowel contents to enter into the elongated tube 1 of the prosthetic device. Any pump that can alternate between pushing and pulling air may be used. Other means for mechanically moving the bowel contents in and out of the prosthetic device may be used, including, but not limited to, mechanical flaps or sequentially inflated balloons.
[0024] The expandable inner member 4 may be constructed of any deformable, non-corrosive material that can withstand the harsh acidic environment of the small intestine, such as plastic or preferably silicone. Inner member inflation tube 5 may be constructed of any narrow tubing such as vinyl tubing. In one embodiment, a balloon dilator manufactured my BOSTON SCIENTIFIC and sold under the MICROVASIVE CRE brand was used for both the inner member inflation tube 5 and the expandable inner member 4 . This balloon dilator was inserted through a small hole in the elongated tube 1 such that the balloon acted as the expandable inner member. The elastic properties of the elongated tube 1 in our embodiment allowed it to stretch around the inner member inflation tube and form a seal.
[0025] The prosthetic device may optionally include means for preventing the backflow of intestinal contents. As can be seen from FIG. 5 and FIG. 6 , in the preferred embodiment, the invention includes unidirectional valves 6 that allow digestive contents to pass through the prosthetic device in one direction only. As the bowel contents are expelled from the lumen of the prosthetic device, the unidirectional valves 6 ensure that digestive contents are only moved toward the direction of the anus. In the present embodiment, the unidirectional valves 6 consist of a deformable material that opens to allow fluid to pass in one direction, but closes when fluid pressure builds in the opposite direction. Such valves are well known in the art. Other unidirectional valves are known in the art and may be used in the prosthetic device.
[0026] In practice, the surgeon positions the prosthetic device between the disconnected ends of the intestine, with attention to the direction of flow if the device contains unidirectional valves 6 . The inflatable cuffs 2 are inserted far enough into each of the disconnected ends of the intestine such that their expansion will cause the inflatable cuffs to press against the undamaged intestinal wall. A syringe or other source of air, such as a pump, is connected to each inflation tube 3 , and air is then forced into the inflatable cuff 2 until the inflatable cuff 2 presses firmly against the intestinal wall. Typically, the device is left in the patient until other major trauma heals.
[0027] If the prosthetic device contains an expandable inner member 4 , to assist in the movement of digestive contents through the prosthetic device, then an inner member inflation tube 5 would be connected to an air pump capable of alternating between pushing or suctioning air.
[0028] When the patient has sufficiently recovered to allow for surgical reattachment of the two disconnected ends of the intestine, the surgeon will deflate the inflatable cuffs 2 by means of a pump capable of removing air, such as a syringe. The prosthetic device can then easily be removed from the patient.
[0029] It should be understood that features of any of these embodiments may be used with another in a way that will now be understood in view of the foregoing disclosure. For example, any embodiment could work with or without the expandable inner member 4 , or with or without the unidirectional valves 6 .
[0030] Although the present invention has been described and illustrated with respect to at least one preferred embodiment and uses therefor, it is not to be so limited since modifications and changes can be made therein which are within the full-intended scope of the invention.
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A prosthetic device for the intestine is disclosed that bypasses an enterocutaneous fistula so that the intestinal tract can properly function without bowel contents leaking onto the skin. The prosthetic device includes means to securely connect and seal it to the intestine, means to push bowel contents through it, and means to prevent the backflow of bowel contents through the digestive tract.
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BACKGROUND OF THE INVENTION
The present invention relates in general air conditioner units, and more specifically to heat exchanger coils for use in an air conditioner unit of the type suitable for mounting on the roof of a vehicle, such as a bus.
Many air conditioner units adapted for mounting on the roof of a vehicle spread the condenser and evaporator functions into two separate packages, requiring considerable roof space as well as creating air drag. Roof mounted air conditioner units which incorporate both the evaporator and condenser functions in a single package quite often limit heat exchanger coil surface area, particularly condenser surface area, limiting the capacity of the unit.
It is an object of the present invention to provide a heat exchanger coil which may be used in an aerodynamically configured roof top air conditioning package which provides an extremely high heat exchange capacity.
It is a further object of the invention to provide a heat exchange coil wherein in a continuous length of coil the orientation of the cross section of the coil changes angularly in two different planes.
SUMMARY OF THE INVENTION
A heat exchanger of the plate fin and tube type which comprises two longitudinally extending sections. The two sections each have a planar cross section and form a continuous length. The sections are bent relative to one another with the planar cross sections of the two sections forming an angular relationship therebetween in two different planes. In a preferred embodiment, a further bend is made thereby forming a third longitudinally extending section.
BRIEF DESCRIPTION OF THE DRAWINGS
This invention may be better understood and its numerous objects and advantages will become apparent to those skilled in the art by reference to the accompanying drawings, in which:
FIG. 1 is a perspective view of a bus having an air conditioner unit according to the present invention mounted on the roof thereof;
FIG. 2 is a perspective view of the air conditioner unit shown in FIG. 1 with the cover thereof opened to show the interior thereof;
FIG. 3 is a view similar to that of FIG. 2 illustrating another embodiment of the invention;
FIG. 4 is a perspective view of the air conditioner unit shown in FIG. 1 with the upper cover and some of the components partially broken away and/or removed in order to facilitate illustration of other features;
FIG. 5 is a plan view of the air conditioner unit of FIG. 1 with the upper cover removed;
FIG. 6 is an enlarged cross sectional view taken along the line 6--6 of FIG. 5;
FIG. 7 is a view similar to FIG. 6 illustrating another embodiment of the invention;
FIG. 8 is a cross sectional view of the unit as taken along the line 8--8 of FIG. 5 illustrating the unit mounted on a bus roof top;
FIG. 9 is a plan view of a condenser heat exchange coil;
FIG. 10 is a side view of the coil of FIG. 9;
FIG. 11 is an end view of the coil of FIG. 9;
FIG. 12 is a cross sectional view of the mounting of an evaporator fan assembly taken along the line 12--12 of FIG. 5;
FIG. 13 is a perspective view of an evaporator air delivery assembly;
FIG. 14 is a perspective view of the evaporator air assembly attachment clip;
FIG. 15 is a broken away perspective view of the partition upon which the evaporator air delivery fans are mounted; and
FIG. 16 is an enlarged view showing engagement of the clip of FIG. 14 with an evaporator fan assembly and the mating hardware.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring now to the drawings, and to FIG. 1 in particular, there is shown a vehicle 10, such as a transit bus, having a front 12, back 14, and first and second sides, 16 and 18, respectively. The bus has a roof 20 and an interior passenger compartment 21 best shown in FIG. 8.
The bus 10 includes an air conditioning system 22, which is made up of a single air conditioner unit 24 and a power pack 23. The power pack 23, which is shown only diagramatically in FIG. 1 is of conventional design and is typically mounted within the bus 10, adjacent to one of the bus sides. As is well understood in the art, the power pack 23 includes a refrigerant compressor, and a prime mover such as an internal combustion engine.
The air conditioner unit 24 is mounted on the roof 20 of the bus by any suitable means (not shown). As will be described in detail below, the air conditioner unit contains the evaporator and condenser coils for the air conditioning system, the blowers or fans for causing circulation of air across these coils, the air passageways for such air flow, as well as other standard components of a vapor compression air conditioning system.
Referring now to FIGS. 2 and 3, wherein two embodiments of the air conditioning unit 24 are shown, it will be noted that the unit comprises a base section 28 and a cover 30. The cover 30 is hinged at one end thereof by suitable hardware (not shown) and is likewise provided with suitable conventional latching hardware (not shown) at the other end thereof to facilitate holding the cover in its closed position as illustrated in FIG. 1 during normal operation of the system. Suitable devices, such as gas struts 26 are provided to hold the cover in the open position when desired.
As will be seen, the base 28 and the cover 30 are molded from a plastic resin, preferably a fiberglass reinforced thermosetting resin, in a single piece unit and are adapted to cooperate with one another when in the closed position to provide structural support of all components in the unit and to define the condenser air flow path and the evaporator air flow path of the unit. The location of the various major components will first be described and then the relationship of these components to the structural elements of the base 28 and the cover 30, and the air flow paths will be described in detail. As best show in FIGS. 2, 3 and 5, the base 28 is provided with a centrally located elongated opening 32. This opening 32 extends parallel to the longitudinal axis 34 of the base 28. As is seen in the various drawing figures, this axis extends between the front and back of the vehicle and is substantially parallel to the first and second sides 16 and 18 of the bus 10.
Located adjacent to each of the sides 36 and 38 of the elongated opening 32 is an elongated evaporator coil 40. Since the unit is symmetrical about the longitudinal axis 34, the same reference numerals will be applied to the various components of the system on each side of the axis. Located outboard from the evaporator coils 40 are three evaporator air delivery means 42. Each of the evaporator air delivery means 42 comprises a blower assembly having two blowers 44 driven by an intermediately disposed electric motor 46. Each of the evaporator air delivery means 42 is attached to a partition 48 which forms an integral part of the base 28. Both the partition and the attachment of the evaporator air delivery assemblies 42 thereto will be described in more detail below.
Located outboard from the partitions 48 are the condenser air delivery fans 50. The condenser air delivery fans 50 comprise two groups of three axial flow fans arranged to effect a vertical air flow relative to the unit 24. Two embodiments are illustrated for supporting the condenser air delivery fans 50 in their desired location. With reference to FIG. 2, it will be noted that the condenser air delivery fans 50 are mounted in a spaced relationship within the base 28. With reference to FIG. 3, the condenser air delivery fans 50 are mounted directly to the cover 30. Regardless of the method of mounting, the fans are in the same location when the cover 30 is closed and the unit is in operation. Each of these arrangements will be described in more detail below.
Finally, located outboard from the condenser air delivery fans 50 and adjacent to the sides 52 and 54 the base 28, are the condenser heat exchange coils 56. It should be noted that the condenser coils 56 extend longitudinally from one end 58 of the base in an inclined orientation to the other end 60 of the base wherein they undergo a double bend to transition to a substantially vertical orientation and a further bend 64 to define a U-shaped end thereto. The U-shaped end which provides three surfaces of the condenser surrounding a region 66 in which one of the condenser air delivery fans 50 is located.
Looking now primarily at FIGS. 6, 7 and 8 and with secondary reference to FIGS. 2, 3, 4 and 5, the air flow paths through the air conditioner unit 24 will be described. FIG. 8 illustrates a cross sectional area of the unit 28 mounted on the roof 20 of a bus 10. It should be appreciated that this showing is simplified and is meant only to facilitate the description of the air flow paths. First, the return flow from the passenger compartment 21, as illustrated by arrows 70, is through a longitudinal opening 72 in the roof of the bus which is configured to communicate with the elongated opening 32 in the base 28 of the air conditioner unit. A grill or louvers 74 or the like typically will be provided in the opening 72.
Air flowing from the interior of the bus is caused to flow by action of the evaporator air delivery fans 42 through the openings 72 and 32 and into an elongated plenum 76, which is defined on its upper side by the cover 30 and on its left and right sides by the faces 80 of the evaporator coils 40. Return air drawn in to the plenum 76 is caused to pass through the two evaporator coils 40 wherein it is cooled and dehumidified. Upon passing from the opposite faces 82 of the evaporator coils, the cooled and dehumidified air passes to another plenum 86, which is defined by the upstanding partitions 48, the cover 30 and the bottom 88 of the base 28.
Looking now at FIG. 13, it will be noted that each of the evaporator air delivery assemblies includes a fan mounting plate 90 having a pair of openings therein 92 which cooperate with the discharge openings 94 of each of the individual fans 44. As will be described in more detail hereinbelow, each of the outlets 92 is designed to cooperate with mating openings 98 provided in the partitions 48.
Each of the openings 98 communicates with a supply air passageway 100 each which is defined by a partition wall section 114 formed integrally into the molded base 28. As is evident from several of the drawing views, each of these passageways 100 extends from the mounting of the evaporator air delivery assembly 42 outwardly towards the outer edges of the unit wherein openings 101 are provided in the bottom 88 of the base 28 which cooperate with openings 103 in the roof 20 of the bus to thereby deliver cooled, dehumidified air to the passenger compartment 21.
Looking now to the condenser air flow path. First, the alternative mounting arrangements for the condenser air delivery fans 50 will be described. As mention hereinabove, the condenser air delivery fans are conventional axial flow fans of the type mounted within a shroud assembly 102 and each is driven by an individual motor 104. In the embodiment illustrated in FIGS. 3, 7 and 8, each of the condenser fan assemblies 50 is mounted directly in to an opening 106 provided in the cover 30. A conventional grill or the like 108 is provided to cover the upper surface thereof for aesthetic and safety purposes. Electrical supply wires for each of the motors 104 are not shown in the drawing figures but are adapted to pass from a suitable electrical supply and routed appropriately along the inside of the unit cover 30.
Another embodiment of the mounting of the condenser air delivery fans 50 is shown in FIGS. 2, 5 and 6, wherein the condenser fans, substantially as described above in connection with the previous embodiment, are supported by pedestal like supports 110, which may be molded directly into the base 28. With such an arrangement, the grill assemblies 108 are attached to the cover 30 to cover the openings 106 therein and are designed to mate with the six condenser air delivery fans 50 when the cover is moved to its closed position.
Regardless of the arrangement of supporting the condenser air delivery fans, the air flow path for condenser air is the same and is shown in FIGS. 6, 7 and 8.
As mentioned above, the preferred direction of air flow of the condenser air delivery fans 50 is vertically upwardly as viewed in the drawing figures. As a result, the entire area outside of the partitions 48, the bottom 88 of the base 28 and the upper portion of the cover 30 defines the condenser air flow plenum 112. It should be appreciated with reference to the drawing figures that this region includes the area overlying the partitions 114 which define the supply air passageways 100.
As a result of the above described arrangement, when the condenser fans are operating a region of low pressure is established within the plenum 112 and air flow is caused to move into that region through the various openings 116 provided in the outer periphery of the cover 30. As illustrated in FIGS. 6 and 7, this air flow is directly across the condenser coils 56. It should be appreciated that the condenser fans 50 located within the regions 66 defined by the U-shaped bends in the condenser coils 56 causes air flow to be drawn across three linear sections portion of the condenser coil thereby resulting in an extremely high value of heat transfer occurring in these regions of the unit.
As best shown in FIGS. 4 and 5, the partitions 48 are interconnected at the fight-hand end, as viewed in these drawing figures, by an end partition 118. At the left-hand end, the partitions 48 intersect with additional partition sections 120 which serve to additionally define the evaporator fan plenums 86 and the condenser fan plenums 112.
It will be appreciated with reference to FIGS. 2 and 3 that there is integrally formed with the inner surface 122 of the cover 30 a series of upstanding surfaces, generally 124, which are adapted to mate with the upper ends of the various partition sections 48, 118 and 120 to effectively seal these regions to enhance the efficiency of air flow therethrough. Also, as shown generally by reference numeral 128, gasket or sealing material may be provided on the upper edges of the various partitions in order to further enhance the desired seal.
Referring in detail to the various drawing figures, and in particular FIGS. 9, 10 and 11, the details of the condenser heat exchanger coil 56 are shown. The coil 56 is of the plate fin and tube type comprising a plurality of refrigerant tubes which may comprise two or more rows extending in a serpentine fashion therethrough and having plate type heat exchange fins installed thereon. As is shown in, among other views FIGS. 4, 6, 7 and 8, the condenser coil 56 comprises a major elongated section 130 which is inclined from the vertical. As is best seen in FIGS. 4, 9 and 11, the coil makes a transition from the inclined section 130 through a double bend 62 to a vertically extending section 132. By a double bend it is meant that the heat exchange coil undergoes a bend in two different planes. Specifically, the heat exchange coil makes a 90 degree bend from the major elongated section 130 to the shorter vertical section 132 while at the same time the elongated section 130 is bent from the inclined orientation to the vertical orientation. Further, as mentioned hereinabove, the vertical section 132 then makes a further turn, as at 64, to define the U-shaped section defining the region 66 previously described.
It will be appreciated that the configuration of the condenser heat exchange coil 56 allows a combination of an aesthetically pleasing package wherein the sides of the unit are inclined and the height of the unit is minimized while at the same time allowing an increased length of condenser heat exchange coil to thereby provide optimum performance.
Looking now at FIGS. 12 through 16, the details of attachment of the evaporator air delivery assembly 42 to the partition 48 will be described. As best shown in FIG. 13 and as described hereinabove, each evaporator air delivery assembly 42 includes two blowers or fans 44 driven by an intermediately disposed electric motor 46. The blowers and motor 44, 46 are carded by an evaporator air delivery assembly mounting plate 90. The mounting plate is provided with a vertically extending notch 136 formed in the upper edge 138 thereof.
Looking now at FIG. 15, an upstanding protrusion 140 is integrally molded into the bottom 88 of the base. The upstanding protrusion 140 is spaced from the partition wall 48 a distance substantially equal to the thickness of the mounting plate 90 and defines a space 142 between the protrusion 140 and the wall 48. Attached to the partition wall 48 at a location substantially directly above the protrusion 140 is a vertically oriented U-shaped bracket 144. The bracket 144 may be formed from sheet metal and attached to the partition wall 48 permanently by conventional fastening means.
Installation of the evaporator fan delivery assembly 42 to the partition 48 is achieved by placing the lower edge 146 of the mounting plate 90 into the space 142 between the protrusion 140 and the partition wall 48 with the lower edge 146 resting on the bottom 88 of the base. The plate is then moved in to confronting sealing engagement with the partition wall 48 with the U-shaped bracket 144 extending into the notch 136. As so positioned the openings 92 and in the mounting plate 90 are in fluid flow communication with the openings 98 in the partition wall 48. Attachment of the assembly is then completed by use of a retaining clip 148 as illustrated in detail in FIG. 14. The clip 148 is formed preferably from a sheet metal stamping and comprises three spaced parallel fingers 150. These fingers extend from a U-shaped channel section 152 which structurally interconnects the three fingers and provides a handle type configuration to facilitate easy manual insertion of the clip.
As shown in FIGS. 12 and 16, the clip is adapted such that the middle finger 150 is received within the U-shaped bracket and the two other fingers 150 are adapted to engage the side of the mounting plate 90 which is not in engagement with the partition 48. The size of the U-shaped bracket and the thickness of the fingers 150 are such that the fingers are frictionally retained within the U-shaped bracket 144 and in retaining relationship with the mounting plate 90 to thereby hold the mounting plate in the desired operable engagement with the partition wall 48. Removal of an evaporator fan assembly 42 or replacement for maintenance reasons, accordingly, may be readily carded out by simply withdrawing the retaining clip 148, removing the unit 42 and replacing it with an operable assembly 42, which may in turn be easily attached in the manner described.
It will thus be appreciated that there has been disclosed a new and improved roof mounted air conditioner unit 24 suitable for mounting on the roof of a vehicle such as a bus. The unit comprises a compact efficient arrangement of the heat exchange coils, air delivery passageways, and fans and makes use of an extremely compact yet large surface area condenser coil arrangement. The unit utilizes an evaporator fan mounting arrangement which greatly simplifies the fan mounting and reduces the labor required in replacing such a fan assembly. The air conditioner further comprises a clam shell type arrangement wherein the upper cover is fabricated from a single molded piece, and, the supporting base is also a single piece in which the coils, air handling fans and air supply passages are all molded and/or supported therein.
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A heat exchanger of the plate fin and tube type which comprises two longitudinally extending sections. The two sections each have a planar cross section and form a continuous length. The sections are bent relative to one another with the planar cross sections of the two sections forming an angular relationship therebetween in two different planes. In a preferred embodiment, a further bend is made thereby forming a third longitudinally extending section.
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BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] This invention relates broadly to suturing devices for surgical applications. More particularly, this invention relates to devices that clamp and anchor suture material to tissue.
[0003] 2. State of the Art
[0004] In surgical applications it frequently necessary to anchor tissue with suture material. Typically, the suture material is coupled to a needle and sewn into the tissue surrounding a surgical site (e.g., wound). The two ends of the suture material are tensioned and knotted to provide closure of the surgical site. The ability to control the tension on the suture material is important. To this end it is common for surgeons to tie double knots, that is a first knot to control tension and a second knot to secure the first knot. Such knot tying significantly extends the time required for suturing.
[0005] There have been attempts to provide devices that take the place of conventional suturing with a suture needle and a length of suture material. Examples of devices that pinch or clamp the suture material are described in U.S. Pat. No. 2,075,508 to Davidson; U.S. Pat. No. 3,664,345 to Dabbs et al.; U.S. Pat. No. 3,976,079 to Samuels et al.; U.S. Pat. No. 4,291,698 to Fuchs et al.; U.S. Pat. No. 5,643,295 to Yoon; U.S. Pat. No. 5,720,747 to Burke; U.S. Pat. No. 5,810,853 to Yoon; U.S. Pat. No. 6,010,525 to Bonutti et al.; and U.S. Pat. No. 6,569,187 to Bonutti et al. These clamp-type devices are susceptible to inadvertent slippage of the suture material and loss of tension therein, and also have the disadvantage of requiring complex instruments, of being difficult to manipulate and/or not sufficiently reducing the time required for suturing and tying.
[0006] Thus, there remains a need in the art for devices that facilitate more time efficient and effective suturing and tying.
SUMMARY OF THE INVENTION
[0007] It is therefore an object of the invention to provide devices and methods for suturing tissue in a time efficient and effective manner.
[0008] It is another object of the invention to provide devices and methods for suturing tissue that facilitate control over the tension applied to the suture material.
[0009] It is a further object of the invention to provide suturing devices (and corresponding methods) that are easy to manipulate.
[0010] In accord with these objects, which will be discussed in detail below, a suturing device for surgical applications includes first and second elements that are rotatable with respect to one another about a central axis. Each element has a cutout into its exterior surface. The cutouts, which extend along a direction substantially parallel to the central axis, are adapted to accept suture thread material therein. A central member is disposed along the central axis between the first and second elements to define space therebetween. When the first element is rotated with respect to the second element, the suture thread material is wrapped around the central member in the space between the first and second elements to thereby grasp and hold suture thread material. Preferably, the second element is realized with deformable material such that its cutout collapses and grasps suture material thread disposed therein.
[0011] It will be appreciated that the two elements cooperate to efficiently and effectively grasp and hold suture thread material therein for a broad range of suturing applications, and facilitate tension control on the suture material thread.
[0012] In the preferred embodiment of the invention, the device is made of bioabsorbable material for internal suturing procedures.
[0013] Additional objects and advantages of the invention will become apparent to those skilled in the art upon reference to the detailed description taken in conjunction with the provided figures.
BRIEF DESCRIPTION OF THE DRAWINGS
[0014] FIG. 1A is an exploded view of a suturing device in accordance with the present invention;
[0015] FIG. 1B is a bottom view of the bottom element of the suturing device of FIG. 1A ; and
[0016] FIG. 2 is a schematic view of an alternate suturing device in accordance with the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0017] Turning now to FIGS. 1A and 1B , a suturing device in accordance with the present invention includes two elements 11 A, 11 B, preferably of annular shape as shown, that are rotatable with respect to one another about a central axis 12 . Such rotation is preferably accomplished by affixing a rotating member 13 to the element 11 B. The rotating member 13 rotates freely with respect to element 11 B about the central axis 12 , and snuggly fits into a bottom cavity 15 of element 11 A. The rotating member 13 includes a recess 17 that is accessible through a port 19 extending along the central axis of the element 11 A. The recess 17 is shaped to accept a drive tip 23 formed at the end of a mandrel 21 . The mandrel 21 is inserted thru the port 19 of element 11 A such that the surfaces of the drive tip 23 mate to the surfaces of the recess 17 of the rotating member 13 . Rotation of mandrel 21 causes the rotating member 13 (in addition to the element 11 A affixed thereto) to rotate with respect to element 11 B about the central axis 12 . In this manner, the two elements 11 A, 11 B are rotated with respect to one another.
[0018] Preferably, such rotation is limited to one direction (e.g., either counter-clockwise or clockwise) by an annular ridged surface 25 disposed on the bottom side of the rotating member 13 as shown in FIG. 1B . One or more pawls 27 are disposed on the top side 29 of the element 11 B. The ridged surface 25 and the pawls 27 cooperate such that the rotation of the two elements 11 A, 11 B with respect to one another is limited to one direction (e.g., either counter-clockwise or clockwise).
[0019] The two elements 11 A, 11 B also have cutouts 31 A, 31 B into their exterior as shown in FIG. 1A . The cutouts 31 A, 31 B extend along a direction substantially parallel to the central axis 12 . Preferably, the element 11 B is deformable upon crimping pressure applied thereto (which is preferably applied to one or more crimping grooves 33 disposed on the exterior surface of the element 11 B) such that the cutout 31 B collapses and grasps suture material thread disposed therein as described below.
[0020] The suture material can be made of non-stretchable or stretchable, non-absorbable or absorbable materials. The suture material may also be coated with an antibiotic or other therapeutic drug. The suture material can have various outer-diameter or cross-sectional sizes in accordance with the surgical application.
[0021] Preferably, the elements 11 A, 11 B have an annular shape with a diameter on the order of 0.125 inches and a height on the order of 0.1 inches. Moreover, the elements 11 A, 11 B and the rotating member 13 (and possibly the retention button described below) may be made of non-bioabsorbable material or bioabsorbable material (such as polymers or copolymers of lactide, glycolide, caprolactone, polydioxanone, trimethylene carbonate, polyorthoesters and polyethylene oxide). In addition, the elements 11 A, 11 B and the rotating member 13 (and possibly the retention button described below) may be coated with an antibiotic or other therapeutic drug. In this configuration, the suturing device 10 of FIGS. 1A and 1B can be used for suturing internal tissues and for microsurgical applications.
[0022] During surgical operations, the elements 11 A, 11 B are initially positioned with respect to one another such that the cutout 31 A is substantially aligned with the cutout 31 B as shown. At least one suture material length is sewn into tissue in the vicinity of the surgical site. With the two elements 11 A, 11 B positioned at or near the sewn tissue, one or more segments of the suture material are positioned within the two cutouts 31 A and 31 B and subject to the desired amount of tension.
[0023] While maintaining the desired amount of tension on the suture material, crimping pressure is applied to the element 11 B (preferably by applying pressure to the one or more crimping grooves 33 ) such that the element 11 B deforms and the cutout 31 B collapses and grasps the suture material thread disposed therein, thereby affixing the element 11 B to suture material thread at a position at (or near) the sewn tissue.
[0024] The operator inserts the mandrel 21 through the port 19 such that the surfaces of the drive tip 23 mate to the surfaces of the recess 17 . The mandrel 21 is rotated such that top element 11 A rotates with respect to the bottom element 11 B. Such rotation causes the suture material passing through the cutout 31 A (and to the collapsed cutout 31 B) to wrap around the rotating member 13 in the annular space between the two elements 11 A, 11 B. The wrapping of the suture material around the rotating member 13 , which is preferably formed by one or more complete rotations of the top element 11 A with respect to the bottom element 11 B, effectively binds the suture material thereto. The one-way rotatability of the two elements 11 A, 11 B ensures that the suture material is held by the two elements with the desired amount of tension. In this manner, the suturing device of FIGS. 1A and 1B effectively grasps the suture material thread near tissue at a surgical site, and maintains the desired tension on the suture material thread.
[0025] As described below with respect to FIG. 2 , one end of the suture material may have a retention button permanently affixed thereto. The shape of the retention button can vary provided that it prevents the suture material from being pulled through the sewn tissue when tension is applied to the opposite end of the suture material. In this configuration, the suture material is sewn through the tissue at the surgical site with tension such that the retention button is disposed adjacent the sewn tissue. The other end of the suture material is then grasped and clamped with tension with the suturing device of FIGS. 1A and 1B to effectively maintain the desired tension on the suture material thread. Alternatively, the retention button may be omitted and replaced by a suture knot or other suitable suture retention mechanism.
[0026] An alternate suturing device in accordance the present invention is shown in FIG. 2 . The suturing device 10 ′ includes two elements 11 A′, 11 B′, preferably of annular shape as shown, that are rotatable with respect to one another about a central axis 12 ′. Such rotation is preferably accomplished by a central cylinder 51 that extends through a central annular opening in the top element 11 A′ and into a central annular opening in the bottom element 11 B′. The central annular opening in the bottom element 11 B′ is sized to enable the bottom element to rotate about the central cylinder 51 , while the central annular opening in the top element 11 A′ is sized such that the central cylinder 51 fits snuggly therein. The bottom element 11 B′ is held in place along the central axis 12 ′ by a snap ring or other suitable retention mechanism. The inside of the central cylinder 51 includes a recess portion 17 ′ that mates to the drive tip 23 of the mandrel 21 for rotating the central cylinder 51 (and the top element 11 A′ affixed thereto) with respect to the bottom element 11 B′, thereby rotating the top element 11 A′ with respect to the bottom element 11 B′. Preferably, rotational movement between the two elements 11 A′ and 11 B′ is limited to one direction (e.g., either counter-clockwise or clockwise) by an annular ridged surface (not shown) that is disposed on the bottom side of the element 11 A′ and cooperating pawls (not shown) that are disposed on the top side of the element 11 B′ in a manner similar that described above. The ridged surface and the pawls cooperate such that the rotation of the two elements 11 A′, 11 B′ with respect to one another is limited to one direction (e.g., either counter-clockwise or clockwise).
[0027] The two elements 11 A′, 11 B′ also have cutouts 31 A′, 31 B′ into their exterior as shown in FIG. 2 . The cutouts 31 A′, 31 B′ extend along a direction substantially parallel to the central axis 12 ′. Preferably, the element 11 B′ is deformable upon crimping pressure applied thereto (which is preferably applied to one or more crimping grooves (not shown) disposed on the exterior surface of the element 11 B′) such that the cutout 31 B′ collapses and grasps suture material thread disposed therein as described below.
[0028] The suture material can be made of non-stretchable or stretchable, non-absorbable or absorbable materials. The suture material may also be coated with an antibiotic or other therapeutic drug. The suture material can have various outer-diameter or cross-sectional sizes in accordance with the surgical application.
[0029] Preferably, the elements 11 A′, 11 B′ have an annular shape with a diameter on the order of 0.125 inches and a height on the order of 0.1 inches. Moreover, the elements 11 A′, 11 B′ and the cylinder 51 (and possibly the retention button 55 described below) may be made of non-bioabsorbable material or bioabsorbable material (such as polymers or copolymers of lactide, glycolide, caprolactone, polydioxanone, trimethylene carbonate, polyorthoesters and polyethylene oxide). In addition, the elements 11 A, 11 B and the rotating member 13 (and possibly the retention button 55 described below) may be coated with an antibiotic or other therapeutic drug. In this configuration, the suturing device 10 ′ of FIG. 2 can be used for suturing internal tissues and for microsurgical applications.
[0030] During surgical operations, at least one suture material length is sewn into tissue 53 in the vicinity of the surgical site. Preferably, one end of the suture material length(s) has a retention button 55 permanently affixed thereto. The shape of the retention button 55 can vary provided that it prevents the suture material from being pulled through the sewn tissue 53 when tension is applied to the opposite end of the suture material length. In this configuration, the suture material length is sewn through the tissue at the surgical site with tension such that the retention button is disposed adjacent the sewn tissue 53 as shown. Alternatively, the retention button 55 may be omitted and replaced by a suture knot or other suitable suture retention mechanism.
[0031] The two elements 11 A′, 11 B′ are initially positioned with respect to one another such that the cutout 31 A′ is substantially aligned with the cutout 31 B′ as shown. With the two elements 11 A′, 11 B′ positioned at (or near) the sewn tissue 53 , one or more segments of the suture material (for example, one shown in FIG. 2 ) are positioned within the two cutouts 31 A′ and 31 B′ and subject to the desired amount of tension.
[0032] While maintaining the desired amount of tension on the suture material, crimping pressure is applied to the element 11 B′ (preferably by applying pressure to the one or more crimping grooves as described above) such that the element 11 B′ deforms and the cutout 31 B′ collapses and grasps the suture material thread disposed therein, thereby affixing the element 11 B′ to the suture material thread at a position near the sewn tissue 53 .
[0033] The operator then inserts the mandrel 21 into the central cylinder 51 such that the surfaces of the drive tip 23 mate to the surfaces of the recess 17 ′. The mandrel 21 is rotated such that top element 11 A′ rotates with respect to the bottom element 11 B′. Such rotation causes the suture material passing through the cutout 31 A′ (and to the collapsed cutout 31 B′) to wrap around the central cylinder 51 in the annular space between the two elements 11 A′, 11 B′. The wrapping of the suture material around the central cylinder 51 , which is preferably formed by one or more complete rotations of the top element 11 A′ with respect to the bottom element 11 B′, effectively binds the suture material thereto. The one-way rotatability of the two elements 11 A′, 11 B′ ensures that the suture material is held by the two elements with the desired amount of tension. In this manner, the suturing device of FIG. 2 effectively grasps the suture material thread near tissue at a surgical site, and maintains the desired tension on the suture material thread.
[0034] There have been described and illustrated herein several embodiments of an improved suturing device and a suturing methodology utilizing such devices. While particular embodiments of the invention have been described, it is not intended that the invention be limited thereto, as it is intended that the invention be as broad in scope as the art will allow and that the specification be read likewise. Thus, while particular configurations for guiding and grasping suture material thread and for effectuating rotation of a two suture guiding mechanisms have been disclosed, it will be appreciated that other configurations can be used as well. For example, the top element of the suturing device may also be deformable upon pressure applied thereto such that its cutout collapses and grasps suture material thread disposed therein and the two elements are fixed in position, thereby minimizing the risk of slippage of the suture material thread held therein. It will therefore be appreciated by those skilled in the art that yet other modifications could be made to the provided invention without deviating from its spirit and scope as claimed.
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A suturing device for surgical applications includes first and second elements that are rotatable with respect to one another about a central axis. Each element has a cutout into its exterior surface. The cutouts extend along a direction substantially parallel to the central axis and are sized to accept suture thread material therein. A central member is disposed along the central axis between the first and second elements to define space therebetween. When the first element is rotated with respect to the second element, the suture thread material wraps around the central member in the space between the first and second elements to thereby grasp and hold suture thread material therein. Preferably, the second element is realized from deformable material such that its cutout collapses and grasps suture material thread disposed therein. In this manner, the two elements cooperate to efficiently and effectively grasp and hold suture thread material therein for a broad range of suturing applications, and facilitate tension control on the suture material thread.
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CROSS-REFERENCE TO RELATED APPLICATIONS
This application claims priority from U.S. Provisional Application No. 62/204,145, filed Aug. 12, 2015, the entire contents of which are incorporated by reference in their entirety.
FIELD OF THE INVENTION
The present application relates to a process for selectively producing single-isomer benzoprostacyclin derivatives, including beraprost and its derivatives.
BACKGROUND OF THE INVENTION
Prostacyclin derivatives are useful pharmaceutical compounds and possess activities such as platelet aggregation inhibition, gastric secretion reduction, lesion inhibition, and bronchodilation.
Beraprost is a synthetic benzoprostacyclin analogue of natural prostacyclin that is currently under clinical trials for the treatment of pulmonary hypertension and vascular disease (excluding renal disease) in North America and Europe.
Beraprost and related benzoprostacyclin analogues of the formula (I), as defined below, are disclosed, for example, in U.S. Pat. No. 5,202,447 and Tetrahedron Lett. 31, 4493 (1990).
Furthermore, as described in U.S. Pat. No. 7,345,181, several synthetic methods are known to produce benzoprostacyclin analogues.
Known synthetic methods generally require one or more resolutions of intermediates to obtain a pharmacologically active isomer of beraprost, such as beraprost 314-d, or a related benzoprostacyclin analogue. Also, current pharmaceutical formulations of beraprost or a related benzoprostacyclin analogue may consist of several isomers of the pharmaceutical compound, and only one of which is primarily responsible for the pharmacologic activity of the drug.
Isolation of isomers of beraprost compounds from current synthetic methods requires multiple preparative HPLC or chromatographic purification procedures or multiple recrystallizations, which are not preferable or feasible on a commercially applicable scale. Therefore, it is desired to achieve an efficient, commercially applicable synthetic route to the isomers of beraprost or a related benzoprostacyclin analogue.
SUMMARY OF THE INVENTION
In some embodiments, the present invention provides a process for preparing a compound of the following formula:
wherein R 1 represents a cation, H, or C 1 - 12 alkyl,
R 2 and R 3 each represent H or a hydroxy protective group
R 4 represents H or C 1 - 3 alkyl, and
R 5 represents H or C 1 - 6 alkyl, comprising:
(1) reacting a compound of the following formula:
wherein R 2a is H or an hydroxy protective group
with a compound of the following formula:
wherein R 1a is a cation, H, or C 1 - 12 alkyl, X is halogen
to form a compound of the following formula:
wherein R 1a , R 2a and X are each defined above;
(2) cyclizing a compound of formula (IV) to form a compound of the following formula:
wherein R 1a and R 2a are each defined above;
(3) isomerizing an allyl of the compound of formula (V) to form a propenyl resulting in a compound of the following formula:
wherein R 1a and R 2a are each defined above;
(4) ozonolysis and in situ reduction to convert the propenyl of the compound of formula (VI) to an alcohol resulting in a compound of the following formula:
wherein R 1a and R 2a are each defined above, R 6 is H or a hydroxy protective group;
(5) deprotecting an acetate of the compound of formula (VII) to form a compound of the following formula:
wherein R 1a , R 2a and R 6 are each defined above;
(6) selectively deprotecting the primary hydroxy protective group, followed by oxidation of the primary hydroxy group to form an aldehyde, followed by coupling with a side-chain of the formula:
wherein R 4 and R 5 are each defined above, to form a compound of the following formula:
(7) reduction of the ketone, deprotection of any remaining hydroxy protective group and optionally converting the R 1a into a cation or H to form a compound of the following formula:
In some embodiments, the present invention provides a method that produces the compound of formula (I) as a substantially pure single isomer.
In some embodiments, R 2 , R 3 , R 2a and R 6 each independently represent an acetate, a silyl ester (for example trimethylsilyl, triethylsilyl, t-butyldimethylsilyl, t-butyldiphenylsilyl, phenyldimethylsilyl, tetrahydropyranyl), benzoate ester, benzyl or substituted benzyl.
In some embodiments, R 1a is CH 3 and R 2a and R 6 are both H. In some embodiments, X is bromo, iodo, or chloro.
In some embodiments, azobisisobutyronitrile is used as a radical initiator in step (2).
In some embodiments, a catalytic amount of carbonylchlorohydridotris(triphenylphosphine) ruthenium (II) is used in step (3).
In some embodiments, step (4) produces an in situ trapped aldehyde intermediate represented by the compound of formula (XI)
wherein R 1a and R 2a is each defined above.
In some embodiments, sulfuric acid is used in step (5).
In another aspect, the present invention also provides a process for preparing a compound of the following formula:
wherein R 1a represents a cation, H, or C 1 - 12 alkyl and R 2a and R 6 each represent H, a hydroxyl protective group, an acetate protective group, a silyl ether, benzoate ester, benzyl, or substituted benzyl comprising:
(1) performing a Mitsunobu reaction on the compound of the following formula:
wherein R 2a is defined above,
with a compound of the following formula:
wherein R 1a is defined above, X is halogen
to form a compound of the following formula:
wherein R 1a , R 2a and X is each defined above;
(2) radical cyclization of formula (IV) to form a compound of the following formula:
wherein R 1a and R 2a is each defined above;
(3) isomerizing the allyl of the compound of formula (V) to form a propenyl resulting in a compound of the following formula:
wherein R 1a and R 2a is each defined above;
(4) ozonolysis and in situ reduction to convert the propenyl of the compound of formula (VI) to form an alcohol resulting in a compound of the following formula:
wherein R 1a , R 2a and R 6 are each defined above;
(5) deprotection of the acetate of the compound of formula (VII) to form a compound of the following formula:
wherein R 1a , R 2a and R 6 is each defined above.
In some embodiments, the compound of formula (VIII) is produced as a substantially pure single isomer.
In some embodiments, R 2a and R 6 each independently represent an acetate, a silyl ester (for example, trimethylsilyl, triethylsilyl, t-butyldimethylsilyl, t-butyldiphenylsilyl, phenyldimethylsilyl, tetrahydropyranyl), benzoate ester, benzyl or substituted benzyl.
In some embodiments, R 1a is CH 3 , and R 2a and R 6 are both H. In some embodiment, X is chloro, bromo or iodo.
In some embodiments, azobisisobutyronitrile is used in step (2) as a radical initiator.
In some embodiments, a catalytic amount of carbonylchlorohydridotris(triphenylphosphine) ruthenium (II) is used in step (3).
In some embodiments, sulfuric acid is used in step (5).
In some embodiments, the present invention provides a method that can produce a compound of formula (I), as defined below, in a substantially isomerically pure form. In some embodiments, the present invention provides a method for preparing a compound of formula (I) in fewer steps than the prior art. In a preferred embodiment, the present invention provides a method for preparing a compound of formula (I) in commercially useful quantities. In another preferred embodiment, the present invention provides a method that can produce the beraprost diol intermediates represented by formula (VIII), as defined below, in a substantially isomerically pure form, which can be used for the production of pharmaceutical compounds represented by the general formula (I) or other similar compounds. In yet another preferred embodiment, the present invention provides a method comprising a key radical cyclization step for the synthesis of tricyclic beraprost and its derivatives on a larger scale, preferably more than about 2 grams, more preferably more than about 10 grams. In other embodiments, the invention relates to any of the compounds in the reaction schemes depicted herein in a more pure form compared to those obtained by presently known methods, including an isomerically more pure form.
In some embodiments, the synthesis of beraprost diol (7) is carried out in five steps. The first step of the synthesis comprises the coupling of (1R,4R)-4-hydroxycyclopent-2-en-1-yl acetate and 2-bromophenol-6-carbomethoxypropane using a Mitsunobu reaction to obtain bromophenyl acetoxycyclopentenyl ether (3) with a yield of about 89.5%. The second step comprises radical cyclization and in situ radical trapping by reacting with allyltributyltin using azobisisobutyronitrile as a radical initiator. This step permits the formation of a tricyclic core in a stereochemical fashion. The stereochemistry is governed by the stereochemistry of the coupled compound bromophenyl acetoxycyclopentenyl ether (3) at the ether linkage and acetate group, as shown by the chiral purity of beraprost diol (99.9% by HPLC). In some embodiments, the isolated yield for this step is 65.5%. The fourth step comprises isomerizing the allyl group of allyl acetoxycyclopentabenzofuran (4) to propenyl group by using catalytic amount of carbonylchlorohydridotris(triphenylphosphine)ruthenium (II) to obtain alkenyl acetoxycyclopentabenzofuran (5) in 92.6% yield. The propenyl group of alkenyl acetoxycyclopentabenzofuran (5) is converted into alcohol functionality by the process of ozonolysis and in situ reduction using sodium borohydride, which provides hydroxy acetoxycyclopentabenzofuran (6) in 85.5% yield (over two steps). The last step involves deprotecting the acetate group using concentrated sulfuric acid to obtain beraprost diol (7), which is crystallized from MTBE in 80% yield. In some embodiments, the yield may be greater than 80%, greater than 85%, greater than 90%, or greater than 95%. In a preferred embodiment, the overall yield of this process over 5 steps is 37%, or greater than 37% with a chiral purity of 99.9% or more by HPLC. In some embodiments, the overall yield is greater than 40%, greater than 45%, or greater than 50%.
In some embodiments, a method of producing beraprost diol comprises the steps shown below.
In some embodiments, the methods described herein are advantageous over the previous methods for making beraprost or its derivatives as it directly produces the optically active diol, and thus does not require separating the desired isomer from a racemic mixture. In addition, in some embodiments, the methods described herein can be used to synthesize beraprost in only seven or eight steps, which is the shortest chiral route to obtain the beraprost 314d isomer as well as its derivatives.
In some embodiments, the synthesis of beraprost is carried out according to the following scheme.
In some embodiments, the present invention provides a process for preparing a compound of the following formula:
wherein R 1 represents a cation, H, or C 1 - 12 alkyl,
R 2 and R 3 each represent H or a hydroxy protective group,
R 4 represents H or C 1-3 alkyl, and
R 5 represents H or C 1 - 6 alkyl, comprising:
(1) reacting a compound of the following formula:
wherein R 2a is H or an hydroxy protective group,
with a compound of the following formula:
wherein R 1a is a cation, H, or C 1 - 12 alkyl, X is a halogen selected from chloro, bromo and iodo,
to form a compound of the following formula:
wherein R 1a , R 2a and X are each defined above;
(2) cyclizing a compound of formula (IV) to form a compound of the following formula:
wherein R 1a and R 2a are each defined above;
(3) isomerizing an allyl of the compound of formula (V) to form a propenyl resulting in a compound of the following formula:
wherein R 1a and R 2a are each defined above;
(4) ozonolysis and in situ reduction to convert the propenyl of the compound of formula (VI) to form an alcohol resulting in a compound of the following formula:
wherein R 1a and R 2a are each defined above, R 6 is H or a hydroxy protective group;
(5) deprotecting an acetate of the compound of formula (VII) to form a compound of the following formula:
wherein R 1a , R 2a and R 6 are each defined above;
(6) selectively deprotecting the primary hydroxy protective group, followed by oxidation of the primary hydroxy group to form an aldehyde, followed by coupling with a side-chain of the formula:
wherein R 4 and R 1 are each defined above to form a compound of the following formula:
(7) reduction of the ketone, deprotection of any remaining hydroxy protective group and optionally converting the R 1a into a cation or H to form a compound of the following formula:
In some embodiments, the present invention provides a method that produces the compound of formula (XII) as a substantially pure single isomer.
In some embodiments, R 2 , R 3 , R 2a and R 6 each independently represent acetate, trimethylsilyl, triethylsilyl, t-butyldimethylsilyl, t-butyldiphenylsilyl, phenyldimethylsilyl, tetrahydropyranyl, benzoate ester, benzyl, or substituted benzyl.
In some embodiments, R 1a is CH 3 and R 2a and R 6 are both H.
In some embodiments, azobisisobutyronitrile is used as a radical initiator in step (2).
In some embodiments, a catalytic amount of carbonylchlorohydridotris(triphenylphosphine) ruthenium (II) is used in step (3).
In some embodiments, sulfuric acid is used in step (5).
In some embodiments, the present invention provides a process for preparing a compound of the following formula:
wherein R 1 represents a cation, H, or C 1 - 12 alkyl,
R 2 and R 3 each represent H or a hydroxy protective group,
R 4 represents H or C 1-3 alkyl, and
R 5 represents H or C 1 - 6 alkyl, comprising:
(1) reacting a compound of the following formula:
wherein R 2a is H or an hydroxy protective group,
with a compound of the following formula:
wherein R 1a is a cation, H, or C 1 - 12 alkyl, X is a halogen selected from chloro, bromo and iodo,
to form a compound of the following formula:
wherein R 1a , R 2a and X are each defined above;
(2) cyclizing a compound of formula (XVII) to form a compound of the following formula:
wherein R 1a and R 2a are each defined above;
(3) isomerizing an allyl of the compound of formula (XVIII) to form a propenyl resulting in a compound of the following formula:
wherein R 1a and R 2a are each defined above;
(4) ozonolysis and in situ reduction to convert the propenyl of the compound of formula (XIX) to form an alcohol resulting in a compound of the following formula:
wherein R 1a and R 2a are each defined above, R 6 is H or a hydroxy protective group;
(5) deprotecting an acetate of the compound of formula (XX) to form a compound of the following formula:
wherein R 1a , R 2a and R 6 are each defined above;
(6) selectively deprotecting the primary hydroxy protective group, followed by oxidation of the primary hydroxy group to form an aldehyde, followed by coupling with a side-chain of the formula:
wherein R 4 and R 5 are each defined above to form a compound of the following formula:
(7) reduction of the ketone, deprotection of any remaining hydroxy protective group and optionally converting the R 1a into a cation or H to form a compound of the following formula:
In some embodiments, the present invention provides a method that produces the compound of formula (XV) as a substantially pure single isomer of the formula
In some embodiments, R 2 , R 3 , R 2a and R 6 each independently represent acetate, trimethylsilyl, triethylsilyl, t-butyldimethylsilyl, t-butyldiphenylsilyl, phenyldimethylsilyl, tetrahydropyranyl, benzoate ester, benzyl, or substituted benzyl.
In some embodiments, R 1a is CH 3 and R 2a and R 6 are both H.
In some embodiments, azobisisobutyronitrile is used as a radical initiator in step (2).
In some embodiments, a catalytic amount of carbonylchlorohydridotris(triphenylphosphine) ruthenium (II) is used in step (3).
In some embodiments, sulfuric acid is used in step (5).
In some embodiments, the present invention provides a process for preparing four single isomers of the formula (I), (XII), (XXV) and (XXVI). In some embodiment, a method of producing the four isomers comprises the steps shown below.
In some embodiments, the present invention provides a process for preparing a compound of the following formula:
wherein R 1 represents a cation, H, or C 1 - 12 alkyl,
R 2 and R 3 each represent H or a hydroxy protective group,
R 4 represents H or C 1 - 3 alkyl, and
R 5 represents H or C 1 - 6 alkyl, comprising:
(1) protecting a hydroxyl group of a compound of the following formula:
wherein R 1a is a cation, H, or C 1 - 12 alkyl; R 2a and R 6 are each H or a hydroxy protective group, to produce a compound of the following formula:
wherein X is a trityl protecting group, tertiary butyldimethyl silyl (TBDMS), triethyl silyl (TES), methoxy methane (MOM), tertiary butyldiphenyl silyl (TBDPS), acetate, benzoate, or benzyl;
(2) protecting a hydroxyl group of the compound of (XXVII) to form a compound of the following formula:
wherein Y is tertiary butyldimethyl silyl (TBDMS) group, triethyl silyl (TES), methoxy methane (MOM), tertiary butyldiphenyl silyl (TBDPS), acetate, benzoate, or benzyl;
(3) deprotection one of the hydroxyl protective groups to form a compound of the following formula:
(4) oxidation of a hydroxyl group of the compound to form a compound of the following formula:
(5) Reacting with stannanes to form a compound of the following formula:
wherein Z is tributyl tin (SnBu3);
(6) coupling with a compound of the following formula:
to form a compound of the following formula:
wherein R 1 , R 2 , R 4 and R 5 are each defined above,
(7) deprotecting the protective group Y and reducing the ketone of the compound of the formula (XXXIII) to form a compound of the following formula:
In some embodiments, the methods described herein produce the compound of formula (I) as a substantially pure single isomer.
In some embodiments, a method of producing a compound of formula (I) comprises the steps shown below.
In some embodiment, the methods described herein can be used to prepare a compound of formula (I) without the formation of keto-phosphonate side chain from Weinreb amide, and thus avoids the use of butyl lithium which is a strong base. Under strong basic conditions, the methyl group on the keto-phosphate side chain can racemize and hence lose the optical purity (chiral purity). In contrast, the methods described herein use Weinreb amide, which not only reduces the step of conversion to phosphate but also avoids the problem of racemization and reduces impurities in the subsequent steps. Therefore, in some embodiments, the methods described herein provide the advantage of easily obtaining a desired single isomer of esuberaprost with high chiral impurity.
In some embodiments, the a process for preparing a compound of the following formula:
wherein R 1 represents a cation, H, or C 1 - 12 alkyl,
R 2 and R 3 each represent H or a hydroxy protective group,
R 4 represents H or C 1 - 3 alkyl, and
R 5 represents H or C 1 - 6 alkyl, comprises:
(1) reacting a compound of the following formula:
with a compound of the following formula:
in a Grubbs II metathesis reaction, and
(2) base hydrolysis to produce the compound of formula (I).
In some embodiments, the present invention provides a method that produces the compound of formula (I) as a substantially pure single isomer.
In some embodiments, a method of producing a compound of formula (I) comprises the steps shown below.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 shows 1 H NMR spectrum of compound (3).
FIG. 2 shows 1 H NMR spectrum of compound (4).
FIG. 3 shows HPLC profile of compound (4).
FIG. 4 shows 1 H NMR spectrum of compound (4).
FIG. 5 shows HPLC profile of compound (4).
FIG. 6 shows 1 H NMR spectrum of compound (5).
FIGS. 7 a and 7 b show HPLC profile of compound (5).
FIG. 8 shows 1 H NMR spectrum of compound (6).
FIGS. 9 a and 9 b show HPLC profile of compound (6).
FIG. 10 shows 1 H NMR spectrum of compound (7).
FIG. 11 shows HPLC profile of crude sample of compound (7).
FIG. 12 shows HPLC profile of compound (7).
FIG. 13 shows HPLC profile of compound (7) spiked with reference.
FIG. 14 shows HPLC profile of compound (7) spiked with racemic diol.
FIG. 15 shows 13 C NMR spectrum of compound (7).
FIG. 16 shows mass spectrum of compound (7).
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Unless otherwise specified, “a” or “an” means “one or more.” In one embodiment, a method for making a substantially pure isomer of beraprost or its related derivatives of following formula:
wherein R 1 represents a cation, H, or C 1 - 12 alkyl,
R 2 and R 3 each represent H or a hydroxy protective group,
R 4 represents H or C 1 - 3 alkyl, and
R 5 represents H or C 1 - 6 alkyl, comprises:
(1) performing a Mitsunobu reaction on a compound of the following formula:
wherein R 2a is H or an hydroxy protective group,
with a compound of the following formula:
wherein R 1a is a cation, H, or C 1 - 12 alkyl, X is halogen
to form a compound of the following formula:
wherein R 1a , R 2a and X are each defined above;
(2) radical cyclization of formula (IV) to form a compound of the following formula:
wherein R 1a and R 2a are each defined above;
(3) isomerizing the allyl of the compound of formula (V) to form a propenyl resulting in a compound of the following formula:
wherein R 1a and R 2a are each defined above;
(4) ozonolysis and in situ reduction to convert the propenyl of the compound of formula (VI) to form an alcohol resulting in a compound of the following formula:
wherein R 1a and R 2a are each defined above, R 6 is H or a hydroxy protective group;
(5) deprotection of the acetate of the compound of formula (VII) to form a compound of the following formula:
wherein R 1a , R 2a , and R 6 are each defined above;
(6) selectively deprotecting the primary hydroxy protective group, followed by oxidation of the primary hydroxy group to the corresponding aldehyde, followed by coupling with a side-chain of the formula:
wherein R 4 and R 5 are each defined above to form a compound of the following formula:
(7) reduction of the ketone, deprotection of any remaining hydroxy protective group, and optionally converting the R 1a into a cation or H to form a compound of the following formula:
Beraprost 314-d is known as the pharmacologically active isomer of beraprost, which exists as a racemic mixture of four isomers and beraprost 314-d can exist as a pharmaceutically acceptable salt. This compound is represented by the compound of formula (I) wherein R 1 is a cation or H, R 2 and R 3 are H, and R 4 and R 5 are CH 3 .
In a preferred embodiment, the compound of formula (I) is produced as a substantially pure single isomer without need for separating the desired isomer from other isomers. “Substantially pure” can mean greater than 90% of the desired isomer, greater than 95% of the desired isomer, or greater than 98% of the desired isomer. In some embodiments, R 2 and R 3 , R 2a , and R 6 of the compound of formula (I) each independently represent acetate, trimethylsilyl, triethylsilyl, t-butyldimethylsilyl, t-butyldiphenylsilyl, phenyldimethylsilyl, tetrahydropyranyl, benzoate ester, benzyl, or substituted benzyl. In a preferred embodiment, R 1a is CH 3 , R 2a and R 6 are both H.
In some embodiments, the radical cyclization of step (2) uses azobisisobutyronitrile as a radical initiator however, it is not limited to only azobisisobutyronitrile there are various other reagents that can be sued as radical initiators including but not limited to 4,4′-Azobis(4-cyanovaleric acid), 4,4′-Azobis(4-cyanovaleric acid), 1,1′-Azobis(cyclohexanecarbonitrile), 2,2′-Azobis(2-methylpropionitrile) and 2,2′-Azobis(2-methylpropionamidine) dihydrochloride.
In some embodiments, the isomerization of step (3) uses a catalytic amount of carbonylchlorohydridotris(triphenylphosphine) ruthenium (II). The isomerization can also be performed by using various other catalysts, including metal catalysts, such as ruthenium metal complexes, such as ruthenium hydride complex and Grubbs catalyst, rhodium metal, such as rhodium chloride (RhCl 3 .xH 2 O), and palladium metal, such as palladium chloride (PdCl 2 ).
In some embodiments, the deprotection of step (5) uses sulfuric acid. However, various other inorganic acids such as HCl and HNO 3 can also be used.
In some embodiments, R 2a can be a protecting group know to a person of ordinary skill in the art, for example, an alkyl, benzyl (Bn), trimethylsilyl (TMS), tert-butyldimethylsilyl (TBDMS), tert-butyldiphenylsilyl (TBDPS), or an acetate (Ac) group.
In some embodiments, step (4) of the claimed method produces an in situ trapped aldehyde intermediate represented by the compound of formula (XI).
In some embodiments, the reduction of the ketone of formula X may be achieved using a non-selective reducing agent, such as for example sodium borohydride with cerium trichloride heptahydrate, and the subsequent diastereomers separated, or alternatively a chiral reducing agent capable of selectively reducing the ketone may be used to obtain substantially one isomer of the resulting alcohol. Selective reducing agents are known in the art and include, for example, (R)-(+)-2-Butyl-CBS-oxazaborolidine and catecholborane, (R)-(+)-2-Methyl-CBS-oxazaborolidine and catecholborane, (+) DIP-chloride, NaBH 4 and 2-(3-Nitrophenyl)-1,3,2-dioxaborolane-4S,5S-dicarboxylic acid (D-TarB-NO 2 ), modified DIBAL reagents, and modified LAH agents.
In one embodiment, the compound of formula (I) is produced as a single isomer represented by formula (I) and in substantially isomerically pure form. In one embodiment, the product represented by formula (I) comprises 90% of the resulting isomeric mixture, or preferably 95% of the resulting isomeric mixture, or more preferably 98% of the resulting isomeric mixture, or even more preferably 99% of the resulting isomeric mixture, and most preferably greater than 99% of the resulting isomeric mixture.
In some embodiments, the beraprost diol of formula (I) is crystallized from MTBE in about 80% yield. In some embodiments, the method produces the compound of formula (I) with a yield of at least 37%. In some embodiments, the method produces the compound of formula (I) with a chiral purity of 99.9% by HPLC.
In some embodiments, a process for preparing a compound of the following formula:
wherein R 1 represents a cation, H, or C 1 - 12 alkyl,
R 2 and R 3 each represent H or a hydroxy protective group,
R 4 represents H or C 1 - 3 alkyl, and
R 5 represents H or C 1-6 alkyl, comprises:
(1) reacting a compound of the following formula:
wherein R 2a is H or an hydroxy protective group,
with a compound of the following formula:
wherein R 1a is a cation, H, or C 1 - 12 alkyl, X is a halogen selected from chloro, bromo and iodo,
to form a compound of the following formula:
wherein R 1a , R 2a and X are each defined above;
(2) cyclizing a compound of formula (IV) to form a compound of the following formula:
wherein R 1a and R 2a are each defined above;
(3) isomerizing an allyl of the compound of formula (V) to form a propenyl resulting in a compound of the following formula:
wherein R 1a and R 2a are each defined above;
(4) ozonolysis and in situ reduction to convert the propenyl of the compound of formula (VI) to form an alcohol resulting in a compound of the following formula:
wherein R 1a and R 2a are each defined above, R 6 is H or a hydroxy protective group;
(5) deprotecting an acetate of the compound of formula (VII) to form a compound of the following formula:
wherein R 1a , R 2a and R 6 are each defined above;
(6) selectively deprotecting the primary hydroxy protective group, followed by oxidation of the primary hydroxy group to form an aldehyde, followed by coupling with a side-chain of the formula:
wherein R 4 and R 5 are each defined above to form a compound of the following formula:
(7) reduction of the ketone, deprotection of any remaining hydroxy protective group and optionally converting the R 1a into a cation or H to form a compound of the following formula:
In some embodiments, the present invention provides a method that produces the compound of formula (XII) as a substantially pure single isomer.
In some embodiments, R 2 , R 3 , R 2a and R 6 each independently represent acetate, trimethylsilyl, triethylsilyl, t-butyldimethylsilyl, t-butyldiphenylsilyl, phenyldimethylsilyl, tetrahydropyranyl, benzoate ester, benzyl, or substituted benzyl.
In some embodiments, R 1a is CH 3 and R 2a and R 6 are both H.
In some embodiments, azobisisobutyronitrile is used as a radical initiator in step (2).
In some embodiments, a catalytic amount of carbonylchlorohydridotris(triphenylphosphine) ruthenium (II) is used in step (3).
In some embodiments, sulfuric acid is used in step (5).
In some embodiments, the present invention provides a process for preparing a compound of the following formula:
wherein R 1 represents a cation, H, or C 1 - 12 alkyl,
R 2 and R 3 each represent H or a hydroxy protective group,
R 4 represents H or C 1-3 alkyl, and
R 5 represents H or C 1 - 6 alkyl, comprising:
(1) reacting a compound of the following formula:
wherein R 2a is H or an hydroxy protective group,
with a compound of the following formula:
wherein R 1a is a cation, H, or C 1 - 12 alkyl, X is a halogen selected from chloro, bromo and iodo,
to form a compound of the following formula:
wherein R 1a , R 2a and X are each defined above;
(2) cyclizing a compound of formula (XVII) to form a compound of the following formula:
wherein R 1a and R 2a are each defined above;
(3) isomerizing an allyl of the compound of formula (XVIII) to form a propenyl resulting in a compound of the following formula:
wherein R 1a and R 2a are each defined above;
(4) ozonolysis and in situ reduction to convert the propenyl of the compound of formula (XIX) to form an alcohol resulting in a compound of the following formula:
wherein R 1a and R 2a are each defined above, R 6 is H or a hydroxy protective group;
(5) deprotecting an acetate of the compound of formula (XX) to form a compound of the following formula:
wherein R 1a , R 2a and R 6 are each defined above;
(6) selectively deprotecting the primary hydroxy protective group, followed by oxidation of the primary hydroxy group to form an aldehyde, followed by coupling with a side-chain of the formula:
wherein R 4 and R 5 are each defined above to form a compound of the following formula:
(7) reduction of the ketone, deprotection of any remaining hydroxy protective group and optionally converting the R 1a into a cation or H to form a compound of the following formula:
In some embodiments, the methods described herein produce the compound of formula (XV) as a substantially pure single isomer of the formula
In some embodiments, R 2 , R 3 , R 2a and R 6 each independently represent acetate, trimethylsilyl, triethylsilyl, t-butyldimethylsilyl, t-butyldiphenylsilyl, phenyldimethylsilyl, tetrahydropyranyl, benzoate ester, benzyl, or substituted benzyl.
In some embodiments, R 1a is CH 3 and R 2a and R 6 are both H.
In some embodiments, azobisisobutyronitrile is used as a radical initiator in step (2).
In some embodiments, a catalytic amount of carbonylchlorohydridotris(triphenylphosphine) ruthenium (II) is used in step (3).
In some embodiments, sulfuric acid is used in step (5).
In some embodiments, the present invention provides a process for preparing a compound of the following formula:
wherein R 1 represents a cation, H, or C 1 - 12 alkyl,
R 2 and R 3 each represent H or a hydroxy protective group,
R 4 represents H or C 1-3 alkyl, and
R 5 represents H or C 1 - 6 alkyl, comprising:
(1) protecting a hydroxyl group of a compound of the following formula:
wherein R 1a is a cation, H, or C 1 - 12 alkyl; R 2a and R 6 are each H or a hydroxy protective group, to produce a compound of the following formula:
wherein X is a trityl protecting group;
(2) protecting a hydroxyl group of the compound of (XXVII) to form a compound of the following formula:
wherein Y is TBDMS group;
(3) deprotection one of the hydroxyl protective groups to form a compound of the following formula:
(4) oxidation of a hydroxyl group of the compound to form a compound of the following formula:
(5) Reacting with stannanes to form a compound of the following formula:
where in Z is SnBu 3
(6) coupling with a compound of the following formula:
to form a compound of the following formula:
wherein R 1 , R 2 , R 4 and R 5 are each defined above,
(7) deprotecting the protective group Y and reducing the ketone of the compound of the formula (XXXIII) to form a compound of the following formula:
In some embodiments, the present invention provides a method that produces the compound of formula (I) as a substantially pure single isomer.
In some embodiments, the present invention provides a process for preparing a compound of the following formula:
wherein R 1 represents a cation, H, or C 1 - 12 alkyl,
R 2 and R 3 each represent H or a hydroxy protective group,
R 4 represents H or C 1-3 alkyl, and
R 5 represents H or C 1 - 6 alkyl, comprising:
(1) reacting a compound of the following formula:
with a compound of the following formula:
in a Grubbs II metathesis reaction, and
(2) base hydrolysis to produce the compound of formula (I).
In some embodiments, the methods described herein produce the compound of formula (I) as a substantially pure single isomer.
The present invention is further illustrated by, though in no way limited to, the following examples.
EXAMPLE 1
Synthesis of Bromophenyl Acetoxycyclopentenyl Ether (3)
A 500 mL, three necked, round bottom flask fitted with a dropping funnel, argon inlet and a rubber septum was charged with a solution of (1R,4R)-4-hydroxycyclopent-2-en-1-yl acetate (1) (10.0 g, 70.34 mmol), 2-bromophenol-6-carbomethoxypropane (2) (21.1 g, 77.37 mmol), triphenylphosphine (20.29 g, 77.37 mmol) and triethylamine (7.8 g, 77.37 mmol) in anhydrous tetrahydrofuran (100 mL). To this, diisopropyl azodicarboxylate (15.6 g, 77.37 mmol) was added drop wise at 0° C. over a period of 45 mins. After complete addition, reaction mixture was allowed to attain room temperature slowly. The progress of the reaction was monitored by a TLC with dimensions of 2.5×7.5 cm was used to elute reaction mixture in 20% ethyl acetate and hexanes to confirm complete consumption of starting material. At this stage, the reaction was complete and quenched with a saturated solution of ammonium chloride (150 mL). The organic layer was separated and aqueous layer was extracted with ethyl acetate (2×100 mL). The combined organic layers were washed with brine, dried over sodium sulfate and evaporated in vacuo to obtain crude product (78 g). This was combined with Lot #RD-UT-1137-169 (1 g scale) and purified by chromatography to obtain pure bromophenyl acetoxycyclopentenyl ether (3) (27.5 g, 89.5%). Specifically, a filter-type column of diameter 11.5 cm and 18 cm in length packed with silica gel (551.7 g) was used for purification using ethyl acetate and hexanes. The polarity of the solvent was increased from 0 to 13%. This compound was characterized by 1 H NMR.
TABLE 1
Materials used in Example 1
Name
MW
Lot No.
Amount
mmol
Eq.
(1R,4R)-4-
142.16
SSL-0080-
10.0
g
70.34
1.0
hydroxycyclopent-2-
148-30
en-1-yl acetate (1)
2-Bromopenol-6-
273.12
20141104
21.1
g
77.37
1.1
carbomethoxypro-
pane (2)
Diisopropyl
202.21
T-09-0210
15.6
g
77.37
1.1
azodicarboxylate
(DIAD)
Triphenylphosphine
262.29
MKBK2887V
20.29
g
77.37
1.1
Triethylamine
101.19
T-11-0541
7.8
g
77.37
1.1
Tetrahydrofuran
NA
SHBD8022V
100
mL
NA
NA
(anhydrous)
Silica gel
NA
80107
551.7
g
NA
NA
(230-400 mesh)
The reaction in Example 1 is described in the scheme below:
EXAMPLE 2
Synthesis of Allyl Acetoxycyclopentabenzofuran (4)
A 1000 mL, three necked, round bottom flask fitted with a condenser, a dropping funnel and a rubber septum was charged with a solution of bromophenyl acetoxycyclopentenyl ether (3) (27.0 g, 68.00 mmol) and allyltributylstannane (135.1 g, 408.00 mmol) in anhydrous toluene (50 mL) and heated to 110° C. under argon. The reaction system was evacuated to remove atmospheric air and replaced with argon. To this solution a suspension of AIBN (5.6 g, 34.00 mmol) in toluene (100 mL) was added in one portion and heating was continued at reflux temperature for 10 minutes. The progress of the reaction was monitored by a TLC with dimensions of 2.5×7.5 cm was used to elute reaction mixture in 25% ethyl acetate and hexanes to confirm complete consumption of starting material. A longer TLC helped in resolving the spot closer to the Rf value of starting material. At this stage, the reaction was complete and the reaction mixture was cooled to ambient temperature. This reaction mixture was concentrated in vacuo to remove toluene to half the original volume and then loaded directly onto the silica gel packed column for purification. Specifically, a filter-type column of diameter 11.5 cm and 18 cm length was packed with silica gel (579.7 g) was used for purification using ethyl acetate and hexanes. The polarity of the solvent was increased from 0 to 9%. A smaller filter type column of diameter 9.5 cm and 15 cm length packed with silica gel (396.2 g) was used for purifying impure fractions using the above solvents and polarity. The pure fractions yielded 8.9 g (Lot #RD-UT-1137-175-I) with 95.5% purity (by UPLC) and impure fractions were purified again by a second column chromatography to yield 7.03 g (Lot #RD-UT-1137-175-II) with 96.26% purity (by UPLC). The total isolated yield of allyl acetoxycyclopentabenzofuran (4) was 15.9 g (65.5%). The compound was characterized by 1 H NMR.
TABLE 2
Material used in Example 2
Name
MW
Lot No.
Amount
mmol
Eq.
Bromophenyl
397.27
RD-UT-
27.0
g
68.00
1.0
acetoxycyclo-
1137-172
pentenyl
ether (3)
Allyltributyl-
331.12
05013BJV
135.1
g
408.00
6.0
stannane
Azobisiso-
164.21
MKBJ4237V
5.6
g
34.00
0.5
butyronitrile
(AIBN)
Toluene
NA
SHBD4769V
150
mL
NA
NA
(anhydrous)
Silica gel
NA
80107
975.9
g
NA
NA
(230-400 mesh)
The reaction in Example 2 is described in the scheme below:
EXAMPLE 3
Synthesis of Alkenyl Acetoxycyclopentabenzofuran (5)
A 1000 mL, single necked, round bottom flask fitted with a condenser was charged with a solution of allyl acetoxycyclopentabenzofuran (4) (15.6 g, 43.52 mmol) in anhydrous toluene (500 mL). To this, carbonylchlorohydridotris(triphenylphosphine)ruthenium (II) (2.07 g, 2.17 mmol) was added and then the system was evacuated three times and replaced with argon. This was heated to reflux at 110° C. under argon. The progress of the reaction was monitored by UPLC every 20 mins for 1 hour, which showed 96% conversion and no progress beyond that point. After 1 h, the reaction was concentrated in vacuo to reduce the amount of toluene and then loaded directly onto the silica gel packed column for purification to yield alkenyl acetoxycyclopentabenzofuran (5) (14.5 g, 92.6%) (Lot #RD-UT-1137-178). Specifically, a filter-type column of diameter 11.5 cm and 18 cm in length packed with silica gel (580 g) was used for purification using ethyl acetate and hexanes. The polarity of the solvent was increased from 0 to 8%. The compound was characterized by 1 H NMR and UPLC (ratio of product: starting material, 98.5: 1.5).
TABLE 3
Material used in Example 3
Name
MW
Lot No.
Amount
mmol
Eq.
Allyl
358.42
RD-UT-
15.6
g
43.52
1.0
acetoxycyclo-
1137-175-I
pentabenzofuran
(4)
Carbonylchloro-
952.40
RD-UT-
2.07
g
2.17
0.05
hydridotris(tri-
1137-175-II
phenylphos-
phine)ruthenium(II)
Toluene (anhydrous)
NA
MKBP7702V
500
mL
NA
NA
Silica gel
NA
SHBD6439V
580
g
NA
NA
(230-400 mesh)
The reaction in Example 3 is described in the scheme below:
EXAMPLE 4
Synthesis of Hydroxy Acetoxycyclopentabenzofuran (6)
A 500 mL, three necked, round bottom flask fitted with an ozone bubbler, rubber septa was charged with a solution of alkenyl acetoxycyclopentabenzofuran (5) (14.2 g, 39.61 mmol) in anhydrous methanol (150 mL) and anhydrous dichloromethane (50 mL), and this was cooled to −78° C. Then ozone gas was bubbled through the solution for 2h. Specifically, a Wedeco GSO 10 series ozone generator was used as a source for ozone. The oxygen pressure was maintained at 0.5 psi with instrument running at power level of 81 W. Utmost care should be taken while bubbling the ozone through the reaction mixture. Excess ozone may generate side products in the reaction mixture. Progress of the reaction mixture should be monitored every 25 minutes. Time required for conversion may be higher of lager amounts.
The progress of the reaction was monitored by TLC, which indicated complete conversion of starting material. A small aliquot was quenched with dimethyl sulfide to convert ozonide to aldehyde for in process analysis using 60% ethyl acetate:hexane as mobile phase for TLC. At this stage, the temperature of the reaction mixture was increased to −20° C. and flushed with argon gas for 5 minutes.
To this solution (ozonide intermediate), sodium borohydride (2.99 g, 79.23 mmol) was added at −20° C. and stirred under argon for 0.5 h while allowing the reaction mixture to attain ambient temperature. The progress of the reaction was monitored by TLC. Specifically, a 80% ethyl acetate:hexane mobile phase was used for elution. After completion of the reaction, it was quenched with a saturated solution of ammonium chloride (30 mL) and organic volatiles were evaporated in vacuo. The residue was partitioned between ethyl acetate (200 mL) and water (200 mL). The organic layer was separated and aqueous layer was extracted with ethyl acetate (2×150 mL). The combined organic layers were washed with brine (150 mL), dried over sodium sulfate and evaporated in vacuo to obtain crude product. This was loaded on to the silica gel packed column for purification to obtain hydroxy acetoxycyclopentabenzofuran (6) (11.8 g, 85.5%) (Lot #RD-UT-1137-180). Specifically, a filter-type column of diameter 11.5 cm and 18 cm in length packed with silica gel (622 g) was used for purification using ethyl acetate and hexanes. The polarity of the solvent was increased from 0 to 50%.
The compound was characterized by 1 H NMR and HPLC to determine the amount of homolog impurity formed due to carried over starting material from the previous olefin isomerization step (Step III) (ratio of product:homolog, 99.3:0.7). The structure of homolog impurity is given below.
The reaction in Example 4 is described in the scheme below:
TABLE 4
Material used in Example 4
Name
MW
Lot No.
Amount
mmol
Eq.
Alkenyl
358.42
RD-UT-
14.2
g
39.61
1.0
acetoxycyclo-
1137-178
pentabenzofuran (5)
Methanol (anhydrous)
NA
T-08-0195
150
mL
NA
NA
Dichloromethane
NA
SHBF0333V
50
mL
NA
NA
(anhydrous)
Sodium borohydride
37.83
0000023281
2.99
g
79.23
2.0
Silica gel
NA
80107
622
g
NA
NA
(230-400 mesh)
EXAMPLE 5
Synthesis of Beraprost Diol (7)
A 500 mL, single necked, round bottom flask was charged with a solution of hydroxy acetoxycyclopentabenzofuran (6) (10.7 g, 30.71 mmol) in anhydrous methanol (150 mL). Then a solution of conc. H 2 SO 4 (0.1 mL) in 50 mL methanol was added and stirred overnight (14 h).
Reaction rate was found to be slow based on TLC. A 5% methanol:DCM mobile phase was used for TLC elution. At this stage additional amount of conc. H 2 SO 4 (0.27 mL in 10 mL methanol solution) was charged four times at different intervals (14 h, 21 h, 38 h, 62 h) until completion of the reaction. Reaction was found to be complete after 68 h (total conc. H 2 SO 4 used is 1.18 mL).
At this point, the reaction mixture was cooled to 0° C. and a solution of saturated sodium bicarbonate (25 mL) was added over a period of 5 minutes until pH reached 8. This mixture was evaporated in vacuo to remove organic volatiles and the residue was partitioned between ethyl acetate (150 mL) and water (150 mL). The organic layer was separated and aqueous layer was extracted with ethyl acetate (2×100 mL). The combined organic layers were washed with brine, dried over sodium sulfate and evaporated in vacuo to obtain crude product (9.3 g). Crude product was crystallized from MTBE to obtain beraprost diol (7) (7.5 g, 80% isolated yield) (Lot #RD-UT-1137-182-0). Specifically, crude product was dissolved in 45 mL (5 volumes) MTBE by heating to reflux temperature and slowly cooled to RT. At approx. 30° C., 90 mg of pure seed (beraprost diol, Lot #13-13206-01) was added and stirred at room temperature for 2 h, which yielded thick off-white solid. This was cooled to 10° C. and stirred for 15 minutes and filtered through filter paper (No. 4) while using 5% MTBE:Hexane (50 mL) for washing. The off-white solid material was air dried until constant weight was obtained. This was characterized by 1 H NMR, 13 C NMR, MS, optical rotation, chiral HPLC and melting point. See summary of analytical data table for values.
The reaction in Example 5 is described in the scheme below:
TABLE 5
Material used in Example 5
Name
MW
Lot No.
Amount
mmol
Eq.
Hydroxy
348.40
RD-UT-
10.7
g
30.71
1.0
acetoxycyclo-
1137-180
pentabenzofuran
(6)
Concentrated
NA
T-07-0373
1.18
mL
NA
NA
sulfuric acid
Methanol
NA
T-08-0195
240
mL
NA
NA
(anhydrous)
A summary of Analytical Data on single isomer of Beraprost Diol is shown in the table below.
TABLE 6
Summary of Analytical Data on Single Isomer of Beraprost Diol
S.
No.
Description
Results
1.
Structure
2.
Chemical Name
methyl 4-((1S,2R,3aS,8bS)-2-hydroxy-1- (hydroxymethyl)-2,3,3a,8b-tetrahydro-1H- cyclopenta[b]benzofuran-5-yl)butanoate (or) 1H-Cyclopenta[b]benzofuran-5- butanoic acid, 2,3,3a,8b-tetrahydro-2- hydroxy-1-(hydroxymethyl)-, methyl ester, (1S,2R,3aS,8bS)-
3.
CAS Number
132203-90-8
4.
Lot Number
RD-UT-1137-182-CI
5.
Molecular Formula
C 17 H 22 O 5
6.
Molecular Weight
306.35
7.
MS
Practical Value: [M + Na] + = 329.51
Calculated Value: [M + Na] + = 329.35
8.
Melting Point
64.5 to 66.3° C.
9.
Optical Rotation
[α] D = +25.6 at 25° C. (c 1.000, EtOH)
Ref: [α] D = +25.6 at 24.9° C. (c 1.000, EtOH)
10.
1 H NMR
Conforms to the structure
11.
13 C NMR
Conforms to the structure
12.
Purity by Chiral
99.90%
HPLC
EXAMPLE 6
Synthesis of Beraprost Based on Scheme 4
Beraprost is synthesized according to the method shown in Scheme 4. In particular, the synthesis has the following steps: 1) tritylation of compound 1 having a tricyclic core and side chain for coupling to form compound 2; 2) TBDMS protection to form compound 3; 3) detritylation to form compound 4; 4) oxidation to form compound 5; 5) coupling with tributyl tin to form compound 6; 6) reaction with Weinreb amide to form compound 7; 7) reduction and deprotection to form Beraprost. The reaction conditions for each step is well known in the art, such as described in Das et al., Chem. Rev. (2007), 107:3286-3337.
EXAMPLE 7
Synthesis of Beraprost based on Scheme 5
Beraprost is synthesized according to the method shown in Scheme 4, including a Grubbs II metathesis step and base hydrolysis step. In particular, ruthenium metal catalyst is used for Grubb's metathesis reaction. It involves the use of Grubb's II (the second generation ruthenium catalyst) in solvents, e.g. dichloromethane, methyl tertiary butyl methylether, pentane, hexane, methanol, isopropyl alcohol, tetrahydrofuran, and acetone. The reaction conditions for each step is well known in the art, such as described in Das et al., Chem. Rev. (2007), 107:3286-3337.
|
A method is described for making single isomers of synthetic beraprost diol, a key intermediate for making 314-d isomer of beraprost. The method requires fewer steps than the known methods for making these compounds and can be used to scale up the reaction more easily to produce commercial quantities.
| 2
|
RELATED APPLICATIONS
U.S. Pat. application Ser. No. 120,418, filed Feb. 11, 1980 for an Inflatable Packer System by Felix Kuus.
U.S. Pat. application Ser. No. 124,664, filed Feb. 26, 1980 for a Valve Retrieval Mechanism For An Inflatable Packer System. .
BACKGROUND OF THE INVENTION
1. Field of The Invention
The present invention relates to a valve assembly which may be used in an inflatable packer system. Such packer systems may be employed in a drill stem or formation testing tool. The preferred embodiment of the valve assembly is intended for use, for example, in the "Inflatable Packer System" by Felix Kuus, described and claimed in U.S. Pat. application Ser. No. 120,418, filed Feb. 11, 1980. The teachings of that application are hereby specifically incorporated by reference.
The testing tool may be used to evaluate the producing potential or productivity of an oil or gas bearing zone prior to completing a well. As drilling of a bore hole proceeds, there may be indications, such as those obtained from studying the core, which suggest the desirability of testing one or more formations for producing potential.
For the test, a testing tool is attached to the drill string and lowered into the uncased well bore to isolate the zone to be tested.
It is advantageous to have a tool that can be set at any depth in the well so that several zones can be tested, if desired, on a single trip into the well. Therefore, the valving used to control inflation and deflation of the packer(s) must be designed so that the packer(s) can be inflated and deflated repeatedly.
However, all valve functions can be mechanically controlled only by rotation of the drill string and/or by weight set-down and lifting on the drill string, since those are the only actions which can be taken from the surface.
2. Description of the Prior Art
One tool for well bore testing widley used in the industry is disclosed in U.S. Pat. No. 3,439,740 granted to George E. Conover. The Conover tool is representative of that class of packer inflation systems wherein drill pipe rotatoion actuates a piston pump which displaces fluid into the packer(s).
The Conover tool has a plurality of parts which cooperate together to perform four basic operations: (1) packer inflation by drill stem rotation; (2) flow testing by applying weight set-down on the drill string; (3) shut-in pressure testing by upward pull on the drill string; and (4) packer deflation by the simultaneous application of downward and rotational forces on the drill string to actuate a clutch which allows a mandrel to move downwardly, which in turn moves a sleeve valve downwardly, thereby allowing the packer(s) to deflate. When the packers are reset, initial rotation of the pump causes hydraulic fluid to force the sleeve valve upwardly whereupon further pumping will inflate the packers again.
The Conover tool is mechanically complex due to the functional cooperation required for flow and shut-in testing as well as inflation and deflation of the packers. For instance, the manner in which deflation of the packers is accomplished requires a complicated clutch and valving arrangement. It also requires a simultaneous application of weight and rotation to the drill string, all of which must be accomplished at the surface of the well under test.
Also in the Conover tool, there is no modularity. The pump portion and valve portion are mechanically and functionally interrelated. Therefore, in case of a pump failure or valve failure, the failure cannot be isolated to a particular module and that exchanged for a good one.
SUMMARY OF THE INVENTION
The preferred embodiment of the invention comprises a valve assembly for use in a well testing tool. The valve includes an outer valve member which may be fixed against rotation and against longitudinal movement by means of a drag spring and inflated packer(s), respectively. The outer valve member surrounds an inner valve member which may be moved down and up by means of weight set-down and lifting on the drill string after packer inflation.
The valve assembly may also incorporate a shifting sleeve which can be pumped down by initial flow of inflation fluid to establish an inflation fluid passageway through the valve.
The valve assembly is intended for use to control the flow of inflation fluid to the packer(s). It may also seal off the packer(s) upon initial weight set-down, and vent the test zone to the well annulus during weight set-down to obviate any "plunger" effect on the zone. In addition, it may be used to vent the pressurized inflation fluid to the well annulus during weight set-down. For this purpose, the term "well annulus" is intended to mean that portion of the well on either side of, and usually above, the zone of interest which is to be tested.
At the end of weight set-down, the valve assembly may seal off the test zone from the well annulus to render the zone ready for shut-in and flow testing.
On lifing, the inner valve member may retrieve the shifting sleeve, and interaction between the inner valve member and the shifting sleeve can be employed to allow the packer(s) to deflate.
The valve assembly also preferably equalizes the pressure of the test zone with that of the well annulus upon initial lifting to prevent damage to the packer(s). It may also seal off the inflation fluid vent upon lifting.
BRIEF DESCRIPTION OF THE DRAWINGS
FIGS. 1A-1F show the valve assembly in the elongated or stretched positions;
FIG. 1G illustrates a detail of the shifting sleeve and seal interrelationship;
FIG. 1H shows the shifting sleeve in the pumped-down position; and
FIGS. 1I-1K illustrate the valve in the closed position after weight set-down.
DETAILED DESCRIPTION
Valve Assembly 108
A presently preferred embodiment of valve assembly 108 is shown in FIGS. 1A-1F in the elongated or stretched configuration before pump rotation is started.
In this preferred embodiment the valve assembly 108 includes a cylindrical top sub 420 which is internally threaded near the upper end and internally and externally threaded near the lower end.
The lower end of top sub 420 is threaded onto a longitudinally extending cylindrical upper connector 422 which is externally threaded near the top end thereof with an unthreaded portion extending therebeyond. A conventional O-ring carried by the top sub 420 provides a seal between the unthreaded portion of the upper connector 422 and the top sub 420. The interior diameter of the upper end of upper connector 422 is preferably enlarged as at 424 to receive the lower end of stinger from an adjacent subassembly for example. A conventional O-ring carried by the upper connector 422 may provide a seal between the upper connector 422 and the stinger 362 when the testing tool is made up.
Upper connector 422 is grooved around the exterior periphery toward the upper end as at 426. Passageways 428 running parallel to the center line in the wall of the upper connector 422 extend from the lower face thereof to the groove 426. Pressure relief vents as at 430 (FIG. 1B) extend from the outer surface of upper connector 422 to passageway 428. Upper connector 422 may also be externally threaded near its bottom end as seen in FIG. 4C.
A cylindrical spline sleeve 432, internally threaded at the upper end thereof, threadedly engages the lower end of top sub 420. Internally extending splines, as at 434, run the length of spline sleeve 432 from the threaded portion at the upper end to the lower end thereof. The spline sleeve 432 is also externally threaded at the lower end. In addition, pressure relief ports as at 436 are drilled through the wall toward the upper end thereof.
An upper ring retainer 438, internally threaded at the upper end thereof, may be threaded onto the lower end of spline sleeve 432. The lower end of upper ring retainer 438 preferably terminates in an inwardly depending collar 440. When upper ring retainer 438 is threaded onto spline sleeve 432, a release ring 442 may be clamped between the lower end of spline sleeve 432 and the upper face of collar 440.
A cylindrical torque sleeve 444 may surround a portion of the length of upper connector 422 and be internally threaded near the lower end thereof. Externally, longitudinally extending splines 446 at the upper end of torque sleeve 444 may interact with splines 434 on the interior of spline sleeve 432. Conventional O-rings carried by the torque sleeve 444 preferably provide a seal above pressure relief vent 430 between torque sleeve 444 and upper connector 422.
The internal diameter near the lower end of torque sleeve 444 may be enlarged which provides a shoulder 448 and a seat for another seal 450 between torque sleeve 444 and upper connector 422 below pressure relief vent 430. A detent or shoulder 449 may also be cut into the outer diameter of the torque sleeve 444 for seating the release ring 442. The lower, inner edge of ring 442 may be chamfered slightly to allow it to be pushed over the shoulder 449 for a purpose to be described.
A cylindrical inflation vent sleeve 452 may also surround a portion of the length of upper connector 422 and is preferably externally and internally threaded near the upper and lower ends, respectively. The upper end of inflation vent sleeve 452 bears against the lower end of seal 450 and retains the upper end of seal 450 against shoulder 448 when the upper end of inflation vent sleeve 452 is threaded into the lower end of torque sleeve 444. Pump inflation vents, as at 454, may also be drilled through the wall of inflation vent sleeve 452 toward the upper end thereof and communicate with a space 456 between the inner diameter of inflation vent sleeve 452 and the outer diameter of upper connector 422.
A cylindrical time-delay cylinder 458, externally threaded near its upper end and internally threaded near its lower end as shown in FIGS. 1B and 1C, may be threaded into the bottom end of inflation vent sleeve 452. The upper end of the time delay cylinder 458 may directly overlay a lower portion of upper connector 422. Holes may be drilled through the wall of the time-delay cylinder, near its top and bottom ends, and tapped to receive plugs 460 and 462, respectively. Conventional O-ring seals carried by the plugs may be used to provide for sealing between the plugs and the holes. Conventional O-rings carried by the upper end of time-delay cylinder 458 may also provide a seal between it and the upper connector 422.
A cylindrical time-delay piston 464, internally threaded near its upper end and internally threaded near its lower end, as shown in FIGS. 1B and 1D, respectively, attaches to the bottom end of upper connector 422. A conventional O-ring carried below the threads on the lower end of upper connector 422 may be used to provide a seal between it and time-delay piston 464. Longitudinally extending coaxial passageways in the wall, as at 466, may be drilled from the top of time-delay piston 464 toward the bottom end thereof and terminate in apertures, as at 468, drilled radially through the wall of the time-delay piston in fluid communication with the external diameter thereof.
The upper ends of the passageways 466 may be in fluid communication with the lower ends of passageways 428 in the upper connector 422 (FIG. 1C). Conventional O-rings, one carried by bottom connector 422 and one carried by time-delay piston 464, preferably maintain a fluid-tight connection between the bottom end of upper connector 422 and the upper end of time-delay piston 464.
A space 469 (FIG. 1C) is provided between the inner diameter of time-delay cylinder 458 and the outer diameter of time-delay piston 464 by reducing the external diameter of the piston along a portion of its length. The reduction in the outer diameter of piston 464 also provides a downwardly facing piston face 470. In this preferred embodiment, the clearance between the time-delay cylinder 458 and time-delay piston 464, above piston face 470, is approximately three to five thousandths of an inch in diameter.
Space 469 may preferably be filled with Dow Corning fluid 200, 350 centistoke. Filling may be accomplished by removing the plugs 460 and 462 and pouring the fluid in one opening while venting air from space 469 through the other.
A cylindrical seal retainer 472 (FIGS. 1C and 1D), externally threaded near the upper end thereof and surrounding time-delay piston 464, may be threaded into the bottom end of time-delay cylinder 458. The upper end of seal retainer 472 may underlie a lower length of time-delay cylinder 458 and an O-ring carried by seal retainer 472 may provide a seal therebetween. Two conventional O-rings carried by seal retainer 472 near the upper end thereof may provide a seal between seal retainer 472 and time-delay piston 464.
An equalizing housing 474, externally threaded near the upper end and externally and internally threaded near the bottom end thereof, may be threaded into the lower end of time-delay cylinder 458. An O-ring carried by the equalizing housing 474 maintains a seal between time-delay cylinder 458 and equalizing housing 474.
An upwardly facing, inwardly depending shoulder 476 may be formed on the inner diameter of equalizing housing 474, about midway of its length and below radially extending relief vents, as at 478, drilled through the wall of time-delay piston 464.
Sealing between equalizing housing 474 and time-delay piston 464 just below relief vents 478 may be accomplished by a seal 480. Seal 480 is maintained in position longitudinally between the bottom end of seal retainer 472 and shoulder 476 on equalizing housing 474.
A cone and seal spacer 482, externally threaded approximately midway along its length, threads into the bottom end of the equalizing housing 474 and surrounds time-delay piston 464. Sealing between the cone and seal spacer 482 and the lower length of time delay piston 464 may be provided by a conventional O-ring carried by the cone and seal spacer 482. Another conventional O-ring carried by equalizing housing 474 may provide a seal against cone and seal spacer 482.
The bottom half of the cone and seal spacer 482 overlies openings 468 in time-delay piston 464 and a primary bump 484 on a retrieving sleeve 486. Ports, as at 488, may be drilled through the wall of the cone and seal spacer 482 in fluid communication with openings 468 in the lower length of time-delay piston 464. The lower end of the cone and seal spacer 482 is preferably tapered from the outer diameter to approximately the inner diameter thereof to provide a lifting ramp 490.
Equalizing ports, as at 492 (FIG. 1D), may be drilled through the wall of equalizing housing 474 near the lower end thereof. Sealing between the equalizing housing 474 and time-delay piston 464 below the holes 492 may be accomplished by means of a seal 494. Seal 494 is restrained longitudinally between the upper end of cone and seal spacer 482 and a downwardly facing shoulder 496 on the inner diameter of equalizing housing 474 below equalizing ports 492.
Retrieving sleeve 486 preferably surrounds the lower end of time-delay piston 464 and the upper end thereof bears against a downwardly facing shoulder 498 formed on the outer diameter of the time-delay piston 464. A radially extending secondary bump 500 also extends around the outer periphery of retrieving sleeve 486 below the primary bump 484 and spaced therefrom in the manner shown.
A cylindrical sleeve housing 501 (FIGS. 1D and 1E), internally threaded near both ends, threadedly engages the bottom end of equalizing housing 474. A conventional O-ring carried by equalizing housing 474 may provide a seal between the sleeve housing 501 and equalizing housing 474 above the common threaded portion. Deflate ports 502 may also be drilled through the wall of sleeve housing 501 approximately midway along the length thereof.
A cylindrical lower mandrel 504 (FIGS. 1E and 1F), externally threaded near both ends, threadedly engages the externally threaded lower end of time-delay piston 464. The lowermost unthreaded length of time-delay piston 464 preferably overlies an unthreaded length of lower mandrel 504. A conventional O-ring carried by lower mandrel 504 may provide a seal between the common lengths of time-delay piston 464 and lower mandrel 504.
A cylindrical lower connector 506, internally threaded at its lower end and surrounding lower mandrel 504, threadedly engages the lower end of lower mandrel 504. The inner diameter of the lower connector 506 bears against the outer diameter of the lower mandrel 504 at the upper and lower ends. A passageway 508 is provided between the common lengths of the inner diameter of lower connector 506 and outer diameter of lower mandrel 504, for example, by reducing the outer diameter of lower mandrel 504 between the ends thereof. Conventional O-rings carried by lower mandrel 504 provide seals between the upper and lower ends of the lower mandrel 504 and lower connector 506.
Surrounding the outer periphery of lower connector at its upper end, in descending order, are a seal 510, a seal spacer 512, a connector split ring 514, and another seal 516. The outer diameter of the lower connector 506 may be reduced along the length underlying seal 510, seal spacer 512, and seal 516 and grooved to accommodate the connector split ring 514. Connector split ring 514 may protrude above the outer diameter of lower connector 506 and fit into an internally enlarged lower end of seal spacer 512.
The reduction in the outer diameter of the upper length of lower connector 506 also provides an upwardly facing shoulder 518. Seal 516 is restrained longitudinally between the lower end of seal spacer 512 and shoulder 518. Seal 510 is restrained longitudinally between the lower end of retrieving sleeve 486 and the upper end of seal spacer 512, which in turn bears against connector split ring 514.
Concentrically aligned deflate ports as at 520 and 522 in FIG. 1E, may be drilled through the walls of lower connector 506 and seal spacer 512 respectively, above connector split ring 514 and below seal 510. In addition, inflation fluid ports, as at 524 (FIG. 1F), may be drilled through the wall of lower connector 506 near the lower end thereof in fluid communication with passageway 508.
A cylindrical shifting sleeve 526 (FIG. 1E) preferably surrounds the upper length of lower connector 506 and overlies seal 510, seal spacer 512, and seal 516. The internal diameter of the shifting sleeve 526, from seal 516 downwardly, rides on the external diameter of the lower connector 506 and is adapted to move axially with respect thereto. The internal diameter of the shifting sleeve 526 may be radiused where it overlies seals 510 and 516 as shown in more detail in FIG. 1G. Other deflate ports as at 528 may be drilled through the wall of shifting sleeve 526 in line with deflate ports 502, 522, and 520 in the walls of the sleeve housing 501, seal spacer 512, and lower connector 506, respectively.
The outer diameter of shifting sleeve 526, toward its upper end, bears against the inner diameter of sleeve housing 501 and a conventional O-ring carried by the shifting sleeve 526 may provide a seal therebetween. The uppermost portion of shifting sleeve 526 may have a reduced outer diameter and be externally threaded. Threadedly attached thereto may be the lower, internally threaded end of a collet 530.
The collet may comprise a ramp 532 (FIG. 1D) and spring 534 which may be integral. The ramp 532 tapers upwardly from the inner diameter to nearly the outer diameter thereof. The collet 530 is also split longitudinally from the top end of the ramp 532 to the juncture of the spring 534 with the threaded portion thereof as seen in FIG. 1E.
A bottom sub connector 536 (FIGS. 1E and 1F), externally threaded near the upper end and internally threaded near the bottom end, preferably threadedly engages the lower end of sleeve housing 501. The inner diameter of the upper end of the bottom sub connector 536 may bear against the outer diameter of lower connector 506 and a conventional O-ring carried by bottom sub connector 536 may provide a seal between it and the lower connector 506. Three screws spaced at 120°, one of which is shown at 538, may also be threaded into the upper face of bottom sub connector 536.
Two fluid ports 540 may be drilled through the wall of the bottom sub connector and sealed with pipe plugs 542, as shown. The internal diameter of the bottom sub connector 536, below fluid port 540, may be enlarged to provide a downwardly facing shoulder 544. Passageways, as at 545, may be drilled through the shoulder 544 for communication with fluid ports 540.
A bottom sub 546 (FIG. 1F), externally threaded near the upper end thereof, may threadedly engage the lower end of bottom connector 536. The lowermost length of bottom sub connector 536 may overlie bottom sub 546 and a conventional O-ring carried by the bottom sub 546 used to provide a seal therebetween. The uppermost length of bottom sub 546 may extend into the enlarged internal diameter of bottom sub connector 536.
The inner diameter of the upper end of the bottom sub 546 may be enlarged to generate an upwardly facing shoulder 548, against which the lower end of a seal 550, carried in the resulting enlargement, bears. The upper end of seal 550 may also abut downwardly facing shoulder 544 on bottom sub connector 536. The inner diameter of the bottom sub 546, near the upper end thereof, may bear against the outer diameter of the lower connector 506 and a conventional O-ring carried by the bottom sub 546 used to provide a seal therebetween.
Axially extending fluid passageways, as at 552, may be formed in the wall of bottom sub 546 from the top end toward the bottom end thereof. The passageways may terminate at fluid ports, as at 554, which are formed to extend radially through the wall of bottom sub 546 near the bottom end thereof. The ports 554 may be closed by pipe plugs 556.
The lower end of the bottom sub 546 may be tapered from the outer diameter toward the inner diameter and externally threaded. A conventional O-ring may be carried by the bottom sub 546 just above the threaded portion at the lower end thereof. The bottom sub 546 may also be internally threaded near the lower end thereof and enlarged in diameter to produce a downwardly facing shoulder 558.
A cylindrical adapter 560 may fit within the lower end of bottom sub 546 so that the external diameter at the upper end thereof bears against the internal diameter of bottom sub 546. A conventional O-ring carried by the adapter 560 may provide a seal between the upper, outer surface of the adapter 560 and the inner diameter of the bottom sub 546.
The outer diameter of the adapter 560 may be reduced below the O-ring seal and the reduction terminated at a radially extending collar 562 on adaptor 560. The reduction in outer diameter contributes to forming a fluid passageway 561 between the inner diameter of bottom sub 546 and the outer diameter of adapter 560. In addition, passageways, as at 563, may be axially formed through the collar 562 in fluid communication with passageway 561.
A cylindrical adapter nut 564, externally threaded near the lower end thereof, may be threaded into the lower end of adapter 560. The upper end of the adapter nut 564 thus bears against the lower face of collar 562 and holds the upper face thereof against shoulder 558.
The lowermost end portion of adapter 560 below collar 562 may be reduced in diameter and adapted to fit within the next lower module in the test string.
Operation of Valve 108
When a testing tool is made up, the upper end of top sub 420 may be threaded onto the lower end of an adjacent subassembly, e.g., a check/relief valve (not shown). The lower end of a stinger in such a check/relief valve then fits into enlarged diameter 424 of upper connector 422 in the valve 108. Passageway 372 in check/relief valve 106 is then in fluid communication with passageway 428 in upper connector 422 of valve 108.
Basically, the valve 108 can be considered a telescoping unit. The outer portions of the valve 108, i.e., torque sleeve 444 (FIG. 1B), inflation vent sleeve 452 (FIG. 1B), time-delay cylinder 458 (FIGS. 1B and 1C), equalizing housing 474 (FIGS. 1C and 1D), sleeve housing 501 (FIGS. 1D and 1E), bottom sub connector 536 (FIGS. 1E and 1F), and bottom sub 546 (FIG. 113) are connected to the testing tool below the valve 108 and are held stationary during a test cycle by the inflation of packer 112 singly or packers 112 and 122, in the case of straddle packer test.
The inner portions of the valve 108, i.e., top sub 420 (FIG. 1A), spline sleeve 432 (FIG. 1A), upper connector 422 (FIGS. 1A-1C), time delay piston 464 (FIGS. 1B-1E), lower mandrel 504 (FIGS. 1E and 1F), lower connector 506 (FIGS. 1E and 1F), and any components carried thereby, are connected to the testing tool above the valve 108 and move up and down with the drill string during a test cycle.
As the testing tool is run into the well, valve 108 is in the elongated or stretched position shown in FIGS. 1A-1F. It is held in the elongated or stretched positions by release ring 442 (FIG. 1B) which requires sufficient weight set-down on the drill string to push it over the shoulder 449 and downwardly along the outer circumference of sleeve 444 as will be described presently.
In the stretched configuration and before pump rotation is started, the various ports and vents are positioned as follows:
1. Pump pressure relief vents 430 in upper connector 422 (FIG. 1B) are closed between seal 540 and conventional O-rings, all carried by torque sleeve 444, below and above the pump pressure relief vents 430, respectively.
2. Relief vents 478 in time-delay piston 464 (FIG. 1D) are closed off by seal 480 and the O-rings at the upper end of retainer 472, thereby isolating the inside of the tool below valve 108 from the well annulus.
3. Ports 488 in the cone and seal spacer 482 (FIG. 1D) are always open.
4. Deflate ports 520, 522, and 528 (FIG. 1E) in the lower connector 506, seal spacer 512, and shifting sleeve 526, respectively, are open to the well annulus through deflate ports 502 in sleeve housing 501.
5. Inflation port 524 in the lower end of lower connector 506 (FIG. 1F) is open.
6. Pressure relief ports 436 in the spline sleeve 432 (FIG. 1A) are always open.
When the testing tool has been run into the proper depth, a pump is activated. Inflation fluid flows down passageway 428 in upper connector 422, passageway 466 and holes 468 in time delay piston 464, and ports 488 in cone and seal spacer 482 to enter the space above shifting sleeve 526.
At this point, shifting sleeve 526 is held against downward movement by virtue of ramp 532 engaging secondary bump 500 (FIG. 1D) and seals 510 and 516 (FIGS. 1E and 1G) having snapped into position into the matching radii cut into the inner 26 diameter of shifting sleeve 526.
Pressure buildup above the shifting sleeve 526 moves it downwardly, causing ramp 532 to ride over secondary bump 500 and seals 510 and 516 to disengage from their respective radii. Sleeve 526 moves downwardly until the lower face thereof abuts the heads of screws 538 in the upper face of bottom sub connector 536.
During downward movement of shifting sleeve 526, pressure balance to prevent hydraulic load on shifting sleeve 526 is accomplished through deflate port 502 in sleeve housing 501 (FIG. 1E). As shifting sleeve 526 moves downwardly, well fluid in the space below the shifting sleeve 526 is vented to the well annulus through deflate ports 502.
At this point, the shifting sleeve 526 is in the position shown in FIG. 1H and the ports associated therewith are positioned as follows:
1. Deflate port 528 in shifting sleeve 526 has been sealed off due to having moved below seal 516 carried by lower connector 506.
2. Ports 520 and 522 in the lower connector 506 and seal spacer 512, respectively, are in fluid communication with ports 488 in cone and seal spacer 482 and passageway 508 between lower mandrel 504 and lower connector 506.
Inflation fluid is then free to fow from ports 488 in cone and seal space 482 into the space between the outer diameter of seal spacer 512 and inner diameter of shifting sleeve 526. Ports 522 and 520 in the seal spacer 512 and lower connector 506, respectively, are open and inflation fluid continues flowing into passageway 508 to ports 524 in the wall of the lower length of lower connector 506. Fluid flow continues through ports 540 and passageway 545 in the bottom sub connector 536 to passageway 552 and ports 554 in bottom sub 546. Finally, fluid exits valve 108 through passageway 561 between the inner diameter of bottom sub 546 and the outer diameter of adapter 560 and then through bores 563 formed in collar 562 on adapter 560.
Continued pump rotation maintains the flow of inflation fluid to the packers until they are fully inflated.
After inflation pressure has been reached, packer setting is verified by lifting on the string and observing a weight indicator. Weight is then applied to the drill string against the counterforce supplied by the set packers.
Release ring 442 pushes over shoulder 449 on inflation vent sleeve 452 and the applied weight starts closing the stretched or elongated valve 108. The interaction between release ring 442 and shoulder 449 prevents valve 108 from telescoping during running in when high friction could be present, as in directional drilling, undersize holes, etc.
As seen in FIG. 1A, pressure buildup between the top sub 420 and torque sleeve 444 is prevented during telescoping of the valve 108 by pressure relief ports 436 in the wall of spline sleeve 432. Drilling mud escapes through ports 436 as top sub 420 moves downwardly relative to torque sleeve 444.
First, as the valve telescopes, ports 524 in lower connector 506 (FIG. 1F) pass under seal 550 carried by bottom sub 546. The inflation passage to the packers is thus sealed off to prevent packer deflation. Simultaneously therewith, the relief vents 478 in the time-delay piston 464 (FIG. 1D) pass under seal 480 carried by equalizing housing 474. The interior of the tool and, therefore, the space between the packers, i.e., the test zone, is then in fluid communication with the well annulus through relief vents 478 in the time-delay piston 464 and equalizing ports 492 in the wall of equalizing housing 474. This compensates for the "plunger" effect on the test zone as weight is set down on the drill string.
Valve 108 continues telescoping at a rate governed by the interaction between time-delay piston 464 and time-delay cylinder 458 as determined by the clearance between them, which is preferably between three and five thousandths inch on the diameter. This allows the viscous fluid in space 469, such as Dow Corning 200, 350 centistoke, for example, to slowly be displaced through the clearance. Conventional O-rings above and below volume 469 prevent contamination of the fluid with drilling mud.
Next, pump pressure relief vents 430 in upper connector 422 (FIG. 1B) pass under seal 450 carried by torque sleeve 444. This puts inflation passageway 428 in upper connector 422 in fluid communication with the well annulus through pump inflation vents 454 in the inflation vent sleeve 452. Thus, pressurized inflation fluid above the sealed off packers is vented to the well annulus.
Valve 108 continues telescoping and relief vent 478 in time-delay piston 464 (FIG. 1D) passes under seal 494 carried by equalizing housing 474 and sleeve retrieval bump 484 on retrieving sleeve 486 passes under ramp 532 on collet 530. Relief vent 478 passing under seal 494 seals off and prevents fluid communication between the test zone and the well annulus through equalizing ports 492 in equalizing housing 474. Sleeve retrieval bump 484 passing under 4 ramp 532 prepares the shifting sleeve 526 for retrieval.
Valve 108 continues closing until it is completely collapsed and piston face 470 on time-delay piston 464 (FIG. 1G) has completely traversed space 469. Valve 108 is then 8 in the position shown in FIGS. 1I-1K, ready for drill stem testing, such as, for example, flow and shut-in testing.
Upon completion of the testing, a steady pull is applied to the drill string to slowly elongate valve 108. The rate of elongation is again controlled by the clearance between the time delay piston 464 and time delay cylinder 458. As before, the outside of the valve 108 and the lower portion of the testing tool is held from coming up due to the packers yet being inflated.
During the picking up stroke, relief vents 478 in the time-delay piston 464 (FIG. 1D) cross back under seal 494 carried by equalizing housing 474. This allows fluid communication and thus equalization between the test zone and the well bore through equalizing ports 492 in equalizing housing 474. Therefore, the annulus above the packer(s) will equalize with the tested formation zone and prevent packer damage during deflation.
Second, sleeve retrieval bump 484 on retrieving sleeve 486 moves up and catches ramp 532, part of collet 27 530, on shifting sleeve 526 (FIG. 1D). Shifting sleeve 526 continues moving up with retrieving sleeve 486 until ramp 532 on collet 530 is cammed outwardly by engagement with lifting ramp 490 on cone and seal spacer 482. At this point, sleeve retrieval bump 484 rides under ramp 532 and upward movement of shifting sleeve 526 stops.
Next, the pressure relief vents 430 in the wall of upper connector 422 (FIG. 1B) cross back under seal 450 carried by torque sleeve 444. This seals off inflation passage 428 in upper connector 422 to prevent communication thereof with the well annulus through pump inflation vents 454 in the wall of inflation vent sleeve 452.
As valve 108 continues elongating, fluid ports 524 in the wall of lower connector 506 (FIG. 1F) cross back under seal 550. This allows packer deflation through passageway 508 between the inner diameter of lower connector 506 and outer diameter of lower mandrel 504 and deflate ports 520, 522, 528, and 502 in lower connector 506 (FIG. 1E), seal spacer 512, shifting sleeve 526, and sleeve housing 501, respectively.
Next, relief vents 478 in the wall of time delay piston 464 (FIG. 1D) cross back under seal 480 carried by equalizing housing 474. The bore is thus again sealed off from the well annulus through equalizing ports 492 in the wall of equalizing housing 474.
Finally, release ring 442 carried by upper ring retainer 438 snaps back below shoulder 449 on torque sleeve 444. Now valve 108 is back in its original stretched or elongated position, ready to be either relocated in the well for more testing or retrieved from the well.
In addition to the preceding normal operation of valve 108, torque may be transmitted through the valve. This may be accomplished through the interaction of splines 434 on spline sleeve 432 with splines 446 on torque sleeve 444 (FIG. 1A).
Having now reviewed this Detailed Description and the illustrations of the presently preferred embodiment of this invention, those skilled in the art will realize that the invention may be employed in a substantial number of alternate embodiments. Even though such embodiments may not even appear to resemble the preferred embodiment, they shall nevertheless employ the invention as set forth in the following claims.
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A valve assembly for use in an inflatable packer system comprising an outer valve member, an inner valve member adapted to move axially relative to said outer valve member when weight is set down on and lifted from the system, and a shifting sleeve which is pumped down by inflation fluid with respect to both said inner and outer valve members to establish an inflation fluid passageway.
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FIELD
The invention pertains to flame detectors. More particularly, the invention pertains to modular flame detectors which include interchangeable filter modules.
BACKGROUND
Known flame detectors of a type used in oil refineries and chemical plants often include triple band infrared sensing structures. Such flame detectors currently available in the marketplace are usually sold in fixed configurations. Customers order flame detectors that are either tuned to detect hydrocarbon fires (petroleum products) or non-hydrocarbon fires (hydrogen).
The detectors are tuned to either of these two fire types by the selection of particular wavelength filters that are placed in front of an infrared radiation sensor, such as, for example, a pyroelectric sensor. In known detectors, the filters are permanently affixed to the detectors. Infrared filters usually pass wavelengths of 2-6 microns. Known flame detectors often use three or four channels.
It would be advantageous to be able to easily change the sensing characteristics or, personality of the detector by quickly changing the set of filters in the product. The filters could be factory installable, or field installable.
BRIEF DESCRIPTION OF THE DRAWINGS
FIGS. 1A-1B are various views of a first embodiment of a detector which embodies the invention;
FIGS. 2A-2B are various views of a second embodiment of a detector which embodies the invention; and
FIGS. 3A-3B are various views of another embodiment of a detector which embodies the invention.
DETAILED DESCRIPTION
While embodiments of this invention can take many different forms, specific embodiments thereof are shown in the drawings and will be described herein in detail with the understanding that the present disclosure is to be considered as an exemplification of the principles of the invention, as well as the best mode of practicing same, and is not intended to limit the invention to the specific embodiment illustrated.
In embodiments of the invention, a filter module holds a set of filters that establish the detector's personality, that is, which fires it is optimized to detect. The module can be fitted over broadband infrared or UV detectors that are mounted on a circuit board or any other component mounting member.
The set of filters, or, personality module, could either be changed by a customer or by a manufacturer (in order to be able to offer fewer SKU's). In another aspect of the invention, the filter module can be designed to hold up to six filters. It will be understood that the number of filters is not a limitation of the invention.
The filters can pass infrared or ultraviolet radiation, for example, based on the types of fires of interest. For example, a spectral range of 2-6 microns might be selected for multi-channel IR detectors having changeable filter modules.
In another aspect, and without limitation, two pieces of thin material, metal or plastic, can be used to sandwich the filters. The filters can be any size, but would, preferably be about 0.25 inches in diameter or along an edge. The material could be formed with a pocket or recess to hold the filter in the proper position relative to the respective infrared sensor. The filter-holder, or module, can then be keyed so that it can be plugged into the flame detector.
In a disclosed embodiment, the various modules can be coupled together by using fasteners, by providing threads and a screw-type attachment feature, or, by means of a snap-fit fastener structure. The modules can be installed in an external housing. Depending on the environment, an explosion proof housing can be used.
Control circuits could be mounted on a planar member, such as a printed circuit board along with the sensors. The filter module can overlay the printed circuit board and sensor module, and be attached thereto as discussed above. Such modular detectors could be coupled wirelessly or by cables to a monitoring system.
FIGS. 1A , 1 B illustrate an embodiment of a flame detector 10 which embodies the invention. Detector 10 includes a mounting element 12 , which could be a printed circuit board, a filter module 14 and a cover 16 .
A plurality of pyroelectric sensors 18 is carried on the member 12 . It will be understood that any appropriate type of radiant energy sensor could be used in the detector 10 , without limitation. The type of sensor chosen is not a limitation of the invention.
Control Circuits 20 also carried on element 12 are coupled to members of the plurality 18 , such as 18 a, b c . . . . The control circuits 20 carry out processing of signals from the sensors 18 to determine the presence of fire. The control circuits 20 can also communicate wirelessly, or wired, as indicated at 20 a with a displaced monitoring system S.
The filter module 14 includes a plurality of shaped openings, or recesses, 22 which can receive the various filters 24 . The filters 24 are retained in position relative to optical inputs of sensors 18 , such as 18 - 1 , by a portion 22 a of respective ones of the recesses 22 . An optical path, such as 22 b extends through each of the members of the plurality 22 to enable incoming radiant energy R, perhaps from a fire, which has passed through the various filters 24 , to pass through the member 14 and be incident on the optical inputs 18 - 1 of the sensors 18 .
As would be understood by those of skill in the art, the filters of plurality 24 would be selected to have optical characteristics consistent with the particular incident radiant energy R which is indicative of a type of fire, or fires of interest. Neither the composition, nor the shapes of the filters 24 are limitations of the invention. The members of the plurality 24 can be the same or different depending on the type of fire of interest as well as signal processing by circuits 20 .
The cover 16 protects the filters 24 and retains them in position in the openings 22 , in the recesses 22 a. Openings 26 through the cover 16 provide a plurality of optical paths for incident radiant energy R to enter detector 10 , pass through he filters 24 , and the module 14 so as to be incident on the optical inputs of the sensors 18 .
Elements 12 , 14 , 16 can be coupled together via fasteners, such as 28 - 1 , 28 - 1 , snap-fit members 28 - 2 as in embodiment 30 , or snap-fit elements 38 - 2 of embodiment 50 , all without limitation.
Alternately, threads can be formed on the members, such as 14 , 16 which can be threadably coupled together without needing separate fasteners, such as 28 - 1 , 28 - 2 . It will be understood that the exact form of coupling of the elements 12 , 14 , 16 together is not a limitation of the invention.
The detector 10 can be carried in an explosion proof container 10 a . As would be understood by those of skill in the art, connectors could be carried by the housing 10 a to provide wired communication 20 a to/from the monitoring system S.
In the embodiment 30 of FIGS. 2A , 2 B snap lock-type connectors 38 - 2 which engage slots 14 b have been provided to lock the filter module 14 - 1 to the cover 16 - 1 . In the embodiment 50 of FIGS. 3A , 3 B filter module 14 - 2 is illustrated coupled to mounting member 12 - 1 by snap fit-type connectors 14 c which engages slots 12 b in the mounting plate 12 - 1 . Other elements, as described above that appear in embodiments 30 and 50 have been assigned the same numerals in FIGS. 2A , 2 B, 3 A and 3 B as in embodiment 10 of FIGS. 1A , 1 B.
From the foregoing, it will be observed that numerous variations and modifications may be effected without departing from the spirit and scope of the invention. It is to be understood that no limitation with respect to the specific apparatus illustrated herein is intended or should be inferred. It is, of course, intended to cover by the appended claims all such modifications as fall within the scope of the claims.
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A flame detector includes a sensor module, which carries a plurality of pyroelectric sensors, and a filter module which carries a plurality of replaceable filters with one filter being associated with each sensor. The modules are coupled together and carried in an exterior housing. A cover can overlay the filters to retain them in predetermined positions relative to the respective sensors.
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FIELD OF THE INVENTION
The invention relates to cleaning apparatus; in particular to apparatus for cleaning tracheo-oesophageal valves.
BACKGROUND OF THE INVENTION
A laryngectomy is a surgical procedure which involves the removal of a patient's voice box and other surrounding structures often for treatment of cancer of the larynx.
Tracheo-oesophageal prosthetic valves are devices which allow vocal function to be restored to a patient following a laryngectomy. This type of valve is inserted into a hole between the trachea and the oesophagus. The valve blocks the flow of secretions and food materials from the oesophagus to the airway, but allows a passage of air from the airway into the throat to permit speech.
These valves usually stay in place for approximately 6 months before being replaced by a doctor or nurse or other specially trained therapist. The valves can easily become contaminated with secretions and yeasts from the mouth which can cause infections. This can stop the device working altogether, necessitating the replacement of the valve. To prevent this happening, the valves must be cleaned daily by the patient. If valves are not cleaned effectively then their life span is shortened. Frequent replacement of these indwelling valves is not only inconvenient for a patient but can cause trauma to the opening in which the device is placed. These valves are also expensive and frequent replacement causes unnecessary expense.
Cleaning products available currently include small brushes for insertion into the valve, and pipettes with which to flush liquid through the valve. The pipettes available on the market do not give a good seal against the valve and leakage occurs during use which is inconvenient to the user. Also, the pipettes cannot be used at the same time as using a brush.
US 2002/0056219 describes a device for cleaning the inside of a gun barrel. The cleaner comprises a brush attached to a hollow rod with a handle at the opposite end. The brush is mounted so it can freely rotate when the handle is held stationary. A squeeze bottle containing cleaning fluid at the handle end can be squeezed to allow cleaning fluid to run along the hollow rod and onto the brush.
Brushes and pipettes available for cleaning these valves do not give very effective cleaning. The device described in US 2002/0056219 would not be suitable for cleaning tracheo-oesophageal valves as using this type of device would require the user to manually manipulate and rotate the brush whilst squeezing the bottle to dispense fluid into the valve.
The present invention offers cleaning apparatus that mitigates the above-identified problems.
SUMMARY OF THE INVENTION
The invention provides tracheo-oesophageal valve cleaning apparatus as specified in Claim 1 .
Preferred aspects of the invention are specified in the claims dependent on Claim 1 .
The invention provides apparatus that offers more effective cleaning of indwelling tracheo-oesophageal valves. The apparatus of the invention provides a combined brush and fluid dispenser that dispenses an amount of fluid in a one action flush, the brush being rotated to clean the valve by the same action that forces fluid across the brush and into the valve. More effective cleaning leads to prolonged life of the valves.
BRIEF DESCRIPTION OF THE DRAWINGS
In the drawings, which illustrate preferred embodiments of the invention:
FIG. 1 shows a first embodiment of a cleaning apparatus in a ‘before use’ configuration;
FIG. 2 is an exploded view of the internal workings of the apparatus of FIG. 1 ;
FIG. 3 show the location of a tracheo-oesophageal valve;
FIG. 4 shows the cleaning apparatus of FIG. 1 after use;
FIG. 5 shows a second embodiment of a cleaning apparatus, with a cutaway portion showing the internal workings of the apparatus;
FIG. 6 shows an exploded cross-sectional view of the internal workings of the apparatus of FIG. 5 ;
FIG. 7 shows a further embodiment of a cleaning apparatus with a ring-type handle; and
FIG. 8 shows an embodiment of the cleaning element of the cleaning apparatus of FIGS. 1 and 5 .
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
With reference to FIG. 1 , a first embodiment of a cleaning apparatus 1 comprises a fluid dispenser 2 with a first narrow end 7 and a second broader end 8 . A rod 3 is present within the fluid dispenser 2 . The rod 3 is connected to a shaft 4 which extends beyond the fluid dispenser 2 and out through an outlet 6 . The shaft 4 is connected to a cleaning element, which in the example is a brush 5 .
The brush 5 may be detachable from the tip of the shaft 4 . The shaft 4 may also be removable from the end 19 of the rod 3 . Alternatively, both the brush 5 and shaft 4 may together be detachable from the end 19 of the rod 3 . The brush 5 and shaft 4 or the brush 5 may therefore be removed and replaced as necessary, without the need to replace the cleaning apparatus 1 .
The fluid dispenser 2 includes a cylindrical fluid reservoir 20 . A hollow plunger 17 fits into the cylinder 20 . A seal 9 between the plunger 17 and the cylinder 20 prevents fluid from leaking at broad end 8 of the fluid dispenser 2 . The plunger 17 mounts the seal 21 at one end thereof and a handle 10 at the other end. The rod 3 is located within plunger 17 . The end of the hollow plunger 17 mounting the handle 10 is sealed, whereas the end mounting the seal 9 includes an opening. The rod 3 is located within the plunger 17 .
The fluid reservoir 20 is filled with cleaning fluid for ejection from the outlet 6 . In a preferred embodiment the cleaning fluid is a saline solution or sodium bicarbonate. The reservoir 20 may be pre-filled with cleaning fluid, and the outlet 6 may be provided with a seal to prevent leakage of fluid before use of the apparatus 1 . Alternatively, the user may fill the reservoir 20 with cleaning fluid immediately prior to use.
As shown in FIG. 2 , the rod 3 is generally cylindrical in shape and has a substantially helical groove 13 extending along its outer surface.
The end 18 of the rod 3 is mounted within the plunger 17 such that it can freely rotate about its longitudinal axis. The other end 19 of the rod 3 sits in a housing formed in the dispenser 2 such that the rod 3 can freely rotate about its longitudinal axis but is constrained against movement in the direction X. The plunger 17 includes two protruding elements 15 and 16 each extending into groove 13 of the rod 3 .
In use, the user inserts the brush 5 into the tracheo-oesophageal valve 12 ( FIG. 3 ). A lip 14 of larger diameter than the brush 5 may be present. The lip 14 prevents the user inserting the dispenser 2 too far into valve 12 . Inserting a brush too far into the valve could damage the valve and a replacement may be required. The user grasps the device using the handles 11 and depresses the plunger 17 using the handle 10 , applying pressure in the direction labelled X in FIG. 1 . The movement of the rod 3 is constrained against movement in direction X as the end 19 of the rod 3 is in contact with the walls of the dispenser 2 . The protrusions 15 and 16 are forced to move along the helical groove 13 and the rod 3 is forced to rotate, thereby rotating the brush 5 inside the valve 12 . As the rod 3 rotates, the plunger 17 moves axially inside the dispenser 2 in the direction X. This axial movement of the plunger 17 forces fluid to flow out through the outlet 6 , over the brush 5 , and into the valve 12 . FIG. 4 shows the position of the plunger 17 after use.
The fluid dispenser 2 may be refilled with fluid after each use by placing the outlet 6 into an amount of fluid. Fluid is drawn up into the fluid reservoir 20 of the dispenser 2 by withdrawing the piston 17 to its original position (see FIG. 1 ). The rod 3 is constrained against movement in direction X as it is rotatably connected with the walls of the dispenser 2 . For example the walls of the dispenser 2 may comprise a groove in which sits one or more protrusions extending radially from the rod 3 . The protrusions 15 and 16 are forced to move back along the helical groove 13 . As the plunger 17 is withdrawn, the rod 3 is forced to rotate and the reservoir 20 is re-filled with fluid.
FIGS. 5 and 6 illustrate a second embodiment of the invention. Like reference numerals are used to refer to like features.
With reference to FIGS. 5 and 6 , a second embodiment of cleaning apparatus 25 comprises a fluid dispenser 26 with a first narrow end 27 and a second broader end 28 . A rod 31 is present within the fluid dispenser 26 . The rod 31 is connected to a shaft 4 which extends beyond the dispenser 26 and out through an outlet 29 . The shaft 4 is connected to a brush 5 . As in the previous embodiment, the brush 5 may be detachable from the cleaning apparatus 1 . The shaft 4 may also be removable. The brush 5 and shaft 4 together may be detachable from the cleaning apparatus 1 .
The fluid dispenser 26 includes a cylindrical fluid reservoir 30 . A hollow plunger 32 fits closely into the cylinder 30 . A circular seal 21 between the plunger 32 and the cylinder 30 seals the fluid reservoir 30 , minimising any leakage of fluid from the broad end 28 of the dispenser 26 . The plunger 32 mounts the seal 21 at one end thereof and a handle 10 at the other end. The rod 31 is located within the plunger 32 .
The fluid reservoir 30 is filled with cleaning fluid for ejection from outlet 29 . In a preferred embodiment the cleaning fluid is a saline solution or a sodium bicarbonate solution. As with the previous embodiment, the reservoir 30 may be pre-filled with cleaning fluid, and the outlet 29 may be provided with a seal to prevent leakage of fluid before use of the apparatus 25 . Alternatively, the user may fill the reservoir 30 with cleaning fluid immediately prior to use.
As shown in FIG. 6 , the internal hollow of plunger 32 is substantially cylindrical in shape and has a substantially helical groove 22 extending along its inner surface.
The end 33 of the rod 31 is mounted within the plunger 32 such that it can freely rotate about its longitudinal axis. The other end 34 of the rod 31 sits in a housing formed in the dispenser 26 such that the rod 31 can freely rotate about its longitudinal axis but is constrained against movement in the direction X. The rod 31 includes two protruding elements 23 and 24 each extending into the groove 22 on the internal surface of the hollow plunger 32 .
In use, the user inserts the brush 5 into their tracheo-oesophageal valve 12 ( FIG. 3 ). The narrow end 27 of the dispenser 26 is tapered. The tapered end 35 prevents the user inserting the dispenser 26 too far into valve 12 . The user grasps the device using the handles 11 and depresses the plunger 10 , applying pressure in the direction labelled X in FIG. 5 . The movement of the rod 31 is constrained against movement in direction X as it is rotatably connected with the walls of the dispenser 26 . In this embodiment the rod 31 comprises a circular groove in which sits one or more protrusions 36 and 37 extending radially from the dispenser 26 . Protrusions 36 and 37 are forced to move along this circular groove and hence movement of the rod 31 is constrained against movement in the direction X. As the plunger is depressed, the protrusions 23 and 24 are forced to move along the helical groove 22 and the rod 31 is forced to rotate, thereby rotating the brush 5 inside the valve 12 . As the rod 31 rotates, the plunger 32 moves axially inside the dispenser 26 in the direction X. This axial movement of the plunger 32 forces fluid to flow out through the outlet 29 , over the brush 5 , and into the valve 12 .
As with the previous embodiment, the fluid dispenser 26 may be refilled with fluid after each use by placing the outlet 29 into an amount of fluid. Fluid is drawn up into the fluid reservoir 30 of the dispenser 26 by withdrawing the plunger 32 to its original position. The rod 31 is constrained against movement in direction X as it is rotatably connected with the walls of the dispenser 26 . As fluid is drawn up, the protrusions 23 and 24 on the rod are forced to move back along helical groove 22 . As the plunger 32 is withdrawn, the rod 31 is forced to rotate and the reservoir 30 is re-filled with fluid. There may also be a lip at the broader end 28 of the dispenser 26 to prevent the plunger being unintentionally removed from the dispenser 26 when refilling the fluid reservoir 30 .
In a further embodiment of the invention, illustrated in FIG. 7 , the plunger 32 mounts a ring handle 38 . This feature enables a user to withdraw the plunger 32 using only one finger and means the device can be operated using only one hand.
In any of the aforementioned embodiments of the invention, the brush 5 may include bristles or other projections to aid cleaning of the valve. The brush 5 may include “fin-type” projections 39 such as those shown extending radially from the core 40 of the brush 5 in FIG. 8 . The projections 39 are easier to clean and harder wearing than bristles. They are made of rubber and are simple and inexpensive to manufacture.
The apparatus of the invention enables a user to efficiently clean a tracheo-oesophageal valve using a simultaneous fluid flush and rotating brush. This one step cleaning routine is much easier for a person to carry out and leads to more efficient cleaning, hence prolonging the life of the valve.
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Tracheo-oesophageal valve cleaning apparatus comprises a fluid dispenser with a fluid reservoir and an outlet; a cleaning element mounted proximal to the outlet; and a drive mechanism including an element mounted axially within the said fluid dispenser, wherein axial movement of the element of the drive mechanism towards to the outlet causes both rotation of cleaning element and fluid to be dispensed from the outlet.
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This application claims the benefit of U.S. Provisional Application No. 60/025,729 filed on Sept. 10, 1996.
The invention relates to a water collection device for use with existing rain guttering and roofing. More particularly, the invention relates to a water collector that is positioned within an inside valley of a roof to direct water in a more uniform manner to the guttering.
BACKGROUND OF THE INVENTION
To eliminate clogging of rain gutters by debris, e.g., leaves, various rain gutter covers have been designed to channel water into a rain gutter, while, at the same time, keeping the debris from entering the rain gutter. One such rain gutter cover is disclosed in U.S. Pat. No. 5,216,851 issued Jun. 8, 1993, herein incorporated by reference. Such rain gutter covers function through water adhesion principles that channel water into the gutter via a plurality of apertures formed in the rain gutter cover. These apertures direct the water into the rain gutter while debris of sufficient size is excluded from entering the rain gutter. Typically, such rain gutter covers are attached between a roofline and a lip of the rain gutter along the entire length of the rain gutter.
However, two portions of a roof may meet at an angle (typically, 90 degrees) to form what is known as an inside corner or inside valley. In principle, water flowing along an inside valley flows onto the top flat portion of a gutter cover following a path to the collector portion where, through principles of surface adhesion, the water is delivered into the rain gutter as the debris carried by the water is jettisoned off of the gutter cover. However, the amount of water flowing from an inside valley may exceed the gutter cover's ability to collect the water, thereby permitting much of the water to overflow the gutter cover and to fall onto the ground resulting in soil erosion, basement leakage and so on.
In an attempt to redirect the rain water from the inside valley to a larger cross-section of gutter covers, vertical deflectors or fence-like devices have been installed on the gutter covers. These fence-like devices extend usually 11/2 inches to 3 inches in height and are positioned to interrupt the flow of water before it reaches the gutter covers, thereby diverting the water laterally across the roofing or the horizontal portion of the gutter covers. In essence, the fence-like devices spread the large quantity of water within the inside valley across the roof. Unfortunately, tree debris, twigs, leaves, seeds, and so on accumulate behind the fence-like device, thereby reducing its effectiveness in diverting the rain water. Additionally, debris collecting behind the fence-like device contributes to the deterioration of the roofing material itself. To keep the fence-like device functioning, frequent cleaning is required, which is cumbersome, dangerous and contrary to the intended function of the gutter covers, i.e., keeping the rain gutters maintenance-free.
Therefore, there is a need in the art for a maintenance-free water collection device that functions within an inside valley of the roof without collecting debris.
SUMMARY OF THE INVENTION
The present invention overcomes the disadvantages associated with the prior art. Specifically, the present invention is a water collector for collecting water from roofing that forms an inside valley. The device provides the additional advantage of collecting the water without the device collecting tree debris or becoming clogged with leaves or twigs that may interfere with its function.
The present water collector includes a unitary sheet of metal or plastic such as aluminum, steel or vinyl. This unitary sheet includes an extended flat top portion, which functions as a closed-top portion for covering a lower portion of the inside valley at the gutter juncture. The flat top portion also serves to interfit under and between existing roof materials of the inside valley, such as roof shingles, to securely fasten the invention to the roof. The top portion provides a relatively uninterrrupted smooth path for rain water to travel from the inside valley and onto the top portion. The top portion has ridges for spreading water toward the edges of a gutter cover adjacent to the roofline. The top portion is connected along the front thereof to an arcuate surface (portion) that directs the water downward. The arcuate portion extends into a vertically disposed front portion. The front portion may contain one or more longitudinally extending, generally horizontally disposed rows of interrupted apertures. The interruptions of apertures in each row can be displaced horizontally with respect to the interruptions of the apertures in the next adjacent row, such that there is no path of rain flow down the front portion, which is not interrupted by at least one of the apertures. However, the present invention can also be implemented without any apertures on the front portion.
More specifically, each aperture contains an inwardly and downwardly extending flap provided along the top edge of the aperture, where the flap receives and diverts rain water into the aperture. The front portion can be attached to a conventional rain gutter cover that is mounted just below the water collector. As such, the rain water channeled into the apertures of the present invention is further channeled onto the top of a conventional gutter cover that extends along the gutter adjacent to the roofline.
The present invention is designed as an integral unit so that leaves, for example, and other debris which may clog the valley and gutter can neither enter the gutter nor clog the invention. The water collector is also designed such that it remains stationary without the use of fasteners or glue strips at the shingle interface and can be easily installed by a single unskilled person.
BRIEF DESCRIPTION OF THE DRAWINGS
The teachings of the present invention can be readily understood by considering the following detailed description in conjunction with the accompanying drawing, in which:
FIG. 1 is a perspective view of the preferred embodiment of the present water collector;
FIG. 2 is a sectional view of the preferred embodiment of the present water collector taken along line 2--2 of FIG. 1; and
FIG. 3 is a sectional view of the preferred embodiment of the present water collector taken along line 3--3 of FIG. 1.
To facilitate understanding, identical reference numerals have been used, where possible, to designate identical elements that are common to the Figures.
DETAILED DESCRIPTION
In accordance with the present invention, a rain water collector is provided which can be installed in existing roof valley configurations in conjunction with existing guttering with or without gutter covers. The present water collector is installed in a manner that does not require fastening devices to be applied to the roofing materials. Hence, it is easily installed generally by a single, unskilled person, and it is easily removed and replaced without damaging the roofing.
Referring to FIGS. 1-3, a rain water collector 10 is provided for an inside valley roofing configuration created by two intersecting rooflines 9. Such intersecting rooflines lead to a configuration of guttering connected at an angle, e.g., a right angle (at point 13). However, it should be understood that the present water collector can be implemented to accommodate a roofing juncture of any angles.
The water collector 10 has a closed-top portion 1 having a substantially triangular shape and a front portion 50. In the preferred embodiment, an arcuate front portion 26 is disposed between top portion 1 and front portion 50. Although the present invention is described below with an arcuate front portion 26, it should be understood that the present invention can be modified and implemented without the arcuate front portion 26.
More specifically, the arcuate front portion 26 extends from the top portion into a vertically disposed front portion 50. The front portion 50 may have a plurality of apertures 7 to direct rain water into a rain gutter. However, if a rain gutter cover 3 is available, vertically disposed front portion 50 can be attached along its bottom edge to a flange 2 of the rain gutter cover 3. Water collector 10 is constructed of a unitary sheet of constructed metal such as aluminum, aluminum copper alloy, vinyl or other weather resistant plastic. In one illustrative example, the unitary sheet has a length of approximately three (3) feet and a width of between 8 and 20 inches.
Although the present invention is implemented as a unitary sheet, those skilled in the art will realized that the present invention can be implemented having more than one sheet of material. Furthermore, it should be understood that the size (including the angles between the various portions of the water collector) of the present water collector can be adjusted to accommodate the dimension of a particular roof valley. For example, the front portion 50 does not have to form a right angle with respect to the top portion 1, i.e., these portions are not limited to a horizontal or a vertical configuration. Both portions can be implemented with a slope or pitch with respect to a horizontal or vertical axis.
The top portion 1 is installed such that the front arcuate portion 26 is substantially level (e.g., horizontal) and the top portion 1 is slightly pitched (e.g., 1 to 15 degrees) away from the valley. Such pitch enables water to drain toward the front arcuate portion 26 from an optional rear flap 11 extending from the top portion 1 at an angle that matches the slope of roofing 12. Rear flap 11 is optional, since it is possible to fabricate the water collector such that the top portion 1 is pitched at an angle that matches the slope of roofing 12, thereby allowing a portion of the top portion 1 to be directly inserted between the roofing material without the need of a rear flap. However, if the slope of the roofing 12 is particularly sharp, the angled rear flap allows the top portion 1 to be pitched slightly, i.e., having a less inclined slope than the roofing, thereby allowing the rain water to spread out as it travels across the top portion 1. Therefore, it is generally preferred to incorporate an angled rear flap on the water collector for roofing that has a sharp slope.
To install the water collector 10, flap 11 is slid between the roofing material such as roof shingles, to cause the water collector 10 to be stationary with respect to the roofing as shown in FIG. 3. To complete the installation, the bottom portion of vertically disposed front portion 50 is fastened with screws, rivets or clips 14 to the flange 2 of the top flat portion of gutter cover 3 as shown in FIG. 2. In the event that a gutter cover 3 is not used, the bottom portion of vertically disposed front portion 50 can be attached directly to the rain gutter 6.
The top portion 1 is also provided with longitudinal ridges or weirs 15 extending approximately 1/8 inches to 1/2 inches in height for spreading water to the edges of the collector adjacent to the roofing. The purpose of these ridges is to distribute the rain over a greater surface, so that the rain can be directed into the rain gutter at different points. Although a set of ridges 15 is shown in FIG. 1, those skilled in the art will realize after considering this specification that ridges of different quantity, shape and size can be employed on different locations on the top portion 1 to achieve the same effect.
For example, in an alternate embodiment, a single ridge 15a which is parallel to the front arcuate portion 26, may extend substantially across the entire width of the water collector. In yet another embodiment, a single ridge 15b which starts near the juncture of the rooflines, may extend horizontally and vertically toward the arcuate portion 26. This ridge 15b may have a dome like shape.
The vertical front portion 50 may contain one or more rows of a plurality of apertures 7, where each aperture contains a flap 16 connected to the top of the aperture, such that the flap 16 extends inwardly toward the rain gutter. These apertures can be formed integrally with the substantially vertical front portion 50 by stamping, piercing, or die cutting the flaps from the front portion and by bending the flaps inwardly.
Due to the principle of surface adhesion, rain traversing over the top of the aperture 7 is drawn into the aperture via the flap 16. The configuration of these rows of apertures is such that all generally vertical paths of rain flow downwardly across the vertical front portion 50, are interrupted by at least one of these apertures 7. The size of these apertures (approximately 1/2 inch by 3/4 inch) should be sufficiently small so as to generally prevent leaves and other debris from entering the rain gutter. Those skilled in the art will realize after considering this specification that apertures of different quantity (including the number of rows), shape and size can be employed to achieve the same water channeling effect.
Referring to FIG. 1, the top portion 1 can also be optionally provided with openings 8 for the purpose of directing rain into the rain gutter. Again, the size of these openings (approximately 1/16 inch to 1/4 inch in diameter) should be sufficiently small so as to generally prevent leaves and other debris from entering the rain gutter. These openings 8 are typically distributed over the surface of top portion 1 to enhance the guidance of rain water into the rain gutter. Since water collector 10 is positioned directly over both a portion of the roofing 12 and the rain gutter 6, water entering these openings 8 is either directed to the rain gutter 6 directly or to a different portion of the roofing 12 underlying the water collector 10. In both cases, the desired effect of spreading and directing rain water from the inside valley of a roof into a rain gutter 6 is accomplished.
Those skilled in the art after considering this specification will realize that this water collector 10 can be modified to adopt to valley configurations adjacent to non-connecting guttering at right angles as well as valleys having no roof edge which is adjacent to guttering, or valleys created by a dormer leading to straight guttering. Those skilled in the art after considering this specification will also realize that this water collector 10 can be modified to work with all types of roofing, including but not limited to, wood shingles, metal, slate, tile, and so on. In fact, the present water collector 10 can be used with open unprotected guttering.
Although various embodiments which incorporate the teachings of the present invention have been shown and described in detail herein, those skilled in the art can readily devise many other varied embodiments that still incorporate these teachings.
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A water collector for directing water from roofing configurations that form an inside valley to the rain gutters is disclosed. The device collects the water without the device collecting debris or becoming clogged with leaves or twigs that may interfere with its function.
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CROSS REFERENCE TO RELATED APPLICATION
This application is the national phase under 35 USC 371 of international application no. PCT/EP2011/004263, filed Aug. 25, 2011, which claims the benefit of the priority date of German application no. 10 2010 044 580.0, filed Sep. 7, 2010. The contents of the aforementioned applications are incorporated herein in their entirety.
FIELD OF DISCLOSURE
The invention relates to a method for operating a labelling machine.
BACKGROUND
Containers to be labelled can, for example, be used as bottles for liquids such as beverages. The containers, e.g. bottles, can consist of a transparent or translucent material, for example glass, or of a translucent plastic, e.g. PET. But it is also conceivable that the containers consist of other materials and can be filled with other content.
Before the containers are supplied to the labelling machine, they are thoroughly inspected with suitable inspection devices. For example, it is envisaged that an inspection for foreign matter be performed in which the containers are inspected for unwanted foreign matter in their interiors. For example using belt conveyors, the containers are supplied to the labelling machine on its infeed side. The labelling machine, for example, has a wheel-like main star or a labelling carousel in which the containers are supplied to a labelling assembly so that the containers are provided with labels. Furthermore, prior to reaching the labelling assembly, the containers are oriented into a target position in which the containers are to be labelled so that the respective labels on the respective containers are always identically oriented. The containers are discharged, on the outfeed side, from the labelling machine or from the labelling carousel, with re-inspections then being carried out. The onward transport to the downstream inspection devices can also be performed by means of transporters or belt conveyors. For example, the containers can be checked for sufficient filling level. In the subsequent inspections, the labels are checked e.g. for correct seating, correct orientation relative to embossings or such design features and/or damages, to name but a few examples of inspections.
It is also known to arrange a first inspection unit as an orientation station and a second inspection unit e.g. as a label seating control at the labelling carousel itself.
DE 20 2005 017 180 U1 relates to a device for orienting containers and a labelling machine with such a device. The containers have at least one geometric container feature (embossing) which is to be twisted into a target position. The containers are pre-oriented with a first camera system. In the transport orientation of the container, there follows a further camera system which effects an orientation into the target position, wherein the further camera system captures a narrower area of the circumferential surface than the first camera system. Thus, DE 20 2005 017 180 U1 proposes a multi-stage, namely a three-stage, orientation for the final fine orientation, for which four cameras are provided. The first two cameras, as seen in the conveying direction, form the first orientation stage, the following third camera serves the further orientation, with the following fourth camera serving the fine orientation.
DE 20 2005 020 478 U1 deals with a label seating control of containers that were labelled on a labelling machine. The label seating control has a camera for imaging the containers equipped with labels. An optical facility is arranged between the camera and the container, said facility generating beam paths that capture labels arranged circumferentially and/or above one another, with distance in between, in a staggered manner. In doing so, only the label surfaces of interest are inspected, with all remaining surface areas of the container being disregarded. In this respect, a correct seating of the label relative to a possible embossing cannot be checked with the label seating control of DE 20 2005 020 478 U1.
DE 10 2004 005 994 A1 discloses a labelling machine. It has a device for supplying labels and a labelling assembly. The labelling assembly has a label container, a glue roller, a rotatable carrier provided with glueable removal segments, and a gripping cylinder. Thus, for example, bottles can be provided with labels, wherein the labelling machine can for example be designed as a rotary runner, a linear machine or even a horizontal runner. In the outfeed area of the labelled bottles, a label seating control facility is arranged with which the desired arrangement of the labels on the bottles is monitored. It is conceivable to check the labels for correct seating, for example relating to design features (so-called embossings) arranged on the bottles. It is also possible to check neck labels and chest labels for correct orientation to one another or also relative to the design features. In case of a change of the label seating outside a specifiable tolerance limit, the label seating control facility conveys corresponding signals for selecting a correction facility which acts upon the labelling assemblies so that a correct label seating can be achieved. Naturally, the bottles provided with an incorrectly oriented label are picked out in a rejection device which, of course, is also possible via the correspondingly generated signal of the label seating control facility.
It is known that the labelled containers are re-oriented in respect of the embossing by means of a detection system downstream of the labelling assembly (DE 10 2008 050 249 A1), to be able to perform, for the label seating control, a seating control regarding a crease-free or damaged seating and also regarding the correct orientation relative to the embossing. For example, bottles or similar containers are filled with content by means of a filling device, to then be supplied to the labelling machine. The containers are oriented (first inspection unit) in the labelling machine or before, for example relating to design features (so-called embossings), so that the labels can be applied to the container in orientation to the design features. The labelled containers are re-oriented after labelling and moved on or transported at a (second) inspection device which can be designed as a label seating control. If the label seating control detects containers with a bad or faulty label seating, a signal for rejection is generated. The rejected containers, for example bottles, are stored on a separate transporter. In this respect, for a re-orientation between the labelling assembly and the label seating control, a further detection system is provided, e.g. with the first inspection unit designed as an orientation station.
DE 10 2007 031 218 A1 deals with a device comprising a turntable which is rotatable relative to a base; drives which are arranged on the turntable, wherein each drive comprises an angle sensor; rotary plates which are arranged on the turntable, wherein each drive drives a rotary plate; and a marking track that is immovably connected with the base and revolves around the turntable. Each drive is allocated a sensor on the turntable, with which the marking track can be read out, wherein each drive comprises an electronic circuit with which the orientation regarding the base of the respective rotary plate driven by the drive can be determined from the signal of the angle sensor of the drive and the signal of the allocated sensor. In the rotary plate drive, a program is deposited in the form of a target motion sequence that specifies which rotation angle the rotary plate is to assume in respect of the base relative to the turntable at the turntable's rotation angle currently detected by the sensor. Depending on the application, a different motion sequence of the rotary plate can thus be implemented in case of a rotation of the turntable.
DE 44 41 245 A1 discloses a method for controlling labelled vessels. The control device is integrated into a labelling machine and has a laser range finder. With the laser range finder, it can be ascertained whether a container is provided with a label or not. During an active measurement interval, the laser beam emitted by the laser range finder first hits the surface of a bottle moving past and measures the bottle's distance from the range finder's fixed housing, which thus forms the constant reference point. As soon as the laser beam hits the surface of the label, there arises a sudden reduction in the currently measured distance corresponding to the thickness of the label and, where applicable, of the glue film between the bottle and the label. This sudden change in distance is detected in an evaluation unit and assessed as a criterion for the presence of a label. Correspondingly, the evaluation unit sends no signal or a good signal to a sorting device. If no label exists on the bottle, no sudden change in distance becomes detectable either, so that the evaluation unit emits an error signal to the sorting device which picks out the corresponding bottle. A main disadvantage of this is that the control facility can only ascertain whether a label exists on the bottle or not. However, it cannot be ascertained whether the label is also correctly oriented, for example relative to design features, or has creases.
DE 20 2004 021 611 U1 assumes combined label seating control facilities in which both a label seating control and a contour detection (embossings) are possible. This requires an incident light illumination for detecting both labels and transmitted images as well as a transmitted light illumination for the contour control, wherein two illumination devices emitting from different directions are used. DE 20 2004 021 611 U1 points out that the use of two illumination facilities regarding the matching of individual lighting level and individual lighting duration is problematic, which is why it is proposed to subject containers, with a single illumination facility and specially designed and adapted optical means, to both transmitted light and incident light. The optical means are for example designed as a flat plate with a bright surface or as a mirror which should be arranged at exactly adapted angles and positions relative to the beam path of the single illumination facility. Thus, labels can be checked not only in respect of crease-free or undamaged seating but, simultaneously, also in respect of the correct orientation relative to the embossing. However, this still requires a facility for detecting the embossing, said facility being combined with the label seating control.
SUMMARY
The invention is thus based on the task of specifying a method for operating a labelling machine, said method enabling an orientation of containers according to embossings prior to labelling wherein, for a label seating control, a statement regarding the label position relative to the position of the embossing of the container concerned is possible without further embossing position detection.
In the method according to the invention, it is expedient that feature coordinates of design features of the container are tracked from the position of the first inspection unit arranged in the conveying direction of the labelling machine along the conveying path of the container to a second inspection unit which, for example, is designed as a label seating control.
The first inspection unit has several successive cameras arranged in the conveying direction of the labelling machine, e.g. CCD cameras. It is advantageous for the feature coordinates of the design feature of the container concerned, which are to be passed to the second inspection unit, to be detected by the last camera as seen in conveying direction. Naturally, the term “camera” is not meant to be limiting. Instead, the term “camera” comprises all suitable image or inspection recording facilities.
A design feature within the meaning of the invention comprises, for example, bottle seams and/or surface markings of the container wall, thus so-called embossings.
The method according to the invention preferably comprises the following steps, wherein only the steps after introducing the container concerned into the labelling machine are looked at. Of course, the labelling machine can for example be designed as a rotary runner, linear machine or even horizontal runner.
In a first step after introducing the container into the labelling machine, the container is transported to the first inspection unit which is designed as an orientation station. The first inspection unit, preferably its last camera as seen in the conveying direction, detects the design feature or its feature coordinates, which, as an equivalent for the position of a carrying element on which the container stands upright, is saved or expediently passed by the control system to the second inspection unit, possibly interconnecting a central control unit.
The container is transported to a labelling station. For this purpose, it is apparent that, prior to entering into the labelling station, no further orientation is required in addition to the first orientation due to the first inspection unit.
The labelling station labels the container.
The (labelled) container is transported away from the labelling station in the direction of the second inspection unit.
In the second inspection unit, while synchronising the saved feature coordinates of the design feature, a label seating control is performed which is why the second inspection unit can also be called a label seating control unit.
It is apparent that, due to the feature coordinates of the design feature which are saved or passed to the second inspection unit, a re-orientation of the container prior to entering into the second inspection unit can be dispensed with.
In the known manner, the carrying element is designed as a carrying plate with allocated drive (so-called variodrive), so that the carrying element is rotatable relative to the conveying direction of the labelling machine.
BRIEF DESCRIPTION OF THE FIGURES
Further advantageous designs of the invention are disclosed in the subclaims and the following FIGURE description. The only
FIG. 1 shows a labelling machine according to the invention in a basic representation in which the method according to the invention can be applied.
DETAILED DESCRIPTION
FIG. 1 shows a labelling machine 1 which has a labelling carousel 2 . By way of example, only one labelling assembly 3 is arranged at the labelling carousel 2 . Naturally, several labelling assemblies can also be provided at the labelling carousel 2 . By way of example, the labelling machine 1 is designed as a rotary runner. Naturally, labelling machines designed as linear machines or even as horizontal runners are also possible.
Containers 4 to be labelled are supplied to the labelling carousel 2 on an infeed side (arrow 5 ) which, by way of example, are transported via an infeed star 6 . The labelled containers 4 are rejected on a rejection side (arrow 7 ) from the labelling carousel 2 by means of a rejection star 8 .
The labelling carousel 2 has carrier elements 9 on which one container 4 each stands up. The carrier elements 9 rotate according to the rotation of the labelling carousel 2 together with it; however, they each have a rotary drive so that the upstanding container 4 is rotatable about its centre axis relative to the labelling carousel 2 in or against its rotation direction.
In the conveying direction of the labelling carousel 2 , a first inspection unit 10 is downstream of the infeed side 5 or the infeed star 6 . The first inspection unit 10 virtually represents an orientation station which can detect design features 11 of the respective container 4 . The design features 11 can be a bottle seam or surface markings of the container wall, so-called embossings, which are basically represented as an arrow tip. The first inspection unit 10 has, for example, several cameras such as CCD cameras each recording a circumferential section of the container 4 moving past and thus detecting the actual position of the design feature 11 , that is the actual position of the container 4 on the respective carrier element 9 . This is essentially known, which is why this is not further elaborated here. By means of the resulting actual data and a comparison with required target data, a control signal is generated in a central control unit 12 , said signal effecting a transfer of the container 4 from its actual position to its target position by correspondingly twisting the carrier element 9 . This is achieved by selecting the carrier element 9 or its drive with the control signal. In this target position, the container 4 is oriented with its particular design feature 11 such that a label 18 can be applied oriented relative to the design feature(s) 11 onto the container 4 . In the only FIG. 1 , the label 18 only is, by way of example, a chest label, wherein a label within the meaning of the invention can also have a neck label or is applied to the container 4 as an imprint.
The central control unit 12 is connected in the known manner, via control wires 13 , with the respective carrier element 9 or its drive and, via a control wire 14 , connected with the first inspection unit so that a data exchange or the generated signal is directly implemented. The control wires 13 and 14 are shown dot-dashed, with a wireless data exchange between the components also being possible.
If the respective container 4 reaches the labelling assembly 3 , an adapted change in position of the design feature 11 is effected in order to apply the label or other identifications such as imprints crease-free and undamaged and oriented relative to the design features 11 . In this respect, the term “labelling” within the meaning of the invention means the application of identifications such as labels and/or imprinting or the like on the corresponding outer periphery of the container 4 .
After labelling, the labelled container 4 is supplied to a second inspection unit 15 in which the labels are checked, for example, for correct seating relative to the design feature 11 but, for example, also for crease-free and undamaged seating. Both inspection tasks are performed with adapted, different illumination methods. If the second inspection unit 15 , for example, detects a label that is applied with creases or damaged, a corresponding control signal to a rejection device 16 is generated, which effects the rejection of the faulty container 4 . The rejection device 16 is connected with the second inspection unit 15 via a control wire 17 , wherein the control wire 17 continues onto the central control unit 12 . The control wire 17 is also shown dot-dashed, with a wireless data exchange also being conceivable. Thus, to date, the second inspection unit 15 not only checks the correct seating of the label as regards crease-free or undamaged seating but also the correct orientation relative to the design feature 11 .
This is where the invention applies, beginning with the first inspection unit 10 so that, in the second inspection unit 15 , only the correct seating of the label in respect of crease-free and/or undamaged seating is checked unconnected with the oriented position of the design feature 11 relative to the label.
It is expedient for one of the cameras of the first inspection unit 10 , preferably the last camera of the first inspection unit 10 as seen in the rotation direction of the labelling carousel 2 , to transmit feature coordinates of the design feature(s) 11 via the control wire 14 to the central control unit 12 or to the second inspection unit 15 so that it tracks feature coordinates or the position of the carrying element 9 on the conveying path of the container 4 from the first inspection unit 10 past the labelling assembly 3 to the second inspection unit, i.e. pursues the track of the particular container 4 concerned regarding each resulting twisting of the container 4 or its design features 11 from the target position recorded with the last camera. These tracked feature coordinates of the container 4 or of the carrier element 9 concerned, which can also be called a rotating plate with variodrive, are passed to or saved in the second inspection unit 15 which can also be called a label seating control. Thus, a re-detection of the container 4 concerned or a position detection of the embossing by means of further cameras before the labelling assembly 3 and in particular before the second inspection unit 15 is no longer required.
Moreover, with the procedure according to the invention, an additional detection of the design feature 11 by means of label seating control can be dispensed with, with only creases, damages or such distortions having to be detected. This is advantageous in respect of a very simple design of the second inspection unit 15 or the label seating control, as it now only has to be designed for the clear 360° all-round processing of the container 4 or of the label, wherein standard light sources and standard illumination methods can be used. Specific illuminations for detecting design features are no longer required, so that the label seating control can be standardised throughout.
It is expedient for the invention that the feature coordinates of the embossing of the container 4 , thus for example of a bottle on the labelling carousel 2 or labelling star, are tracked from the position of the last (orientation) camera in the rotation direction of the labelling carousel 2 to the camera unit of the second inspection unit.
Thus, in a first step, the design feature 11 of the container 4 is detected and, as an equivalent for the position of the carrying element 9 (angle degree/angle position of the variodrive) or of the container 4 , saved or transferred by the control system.
The container 4 is, rotatingly, transported to the labelling station 3 , or rotated (rotation of the labelling carousel 2 ).
The container 4 is labelled at the labelling station 3 .
The (labelled) container 4 is transported away from the labelling station 3 in the direction of the second inspection unit 15 or to the label seating control, or rotated (rotation of the labelling carousel 2 ).
In the second inspection unit 15 or in the label seating control, while synchronising with the saved embossing position, only one further label seating control is performed. An additional detection of the embossing by means of label seating control is dispensed with due to the procedure according to the invention. For this, the feature coordinates of the embossing are simply accepted by the second inspection unit 15 from the last orientation camera.
Naturally, the rotation directions of the labelling carousel 2 , shown in FIG. 1 , are only examples in connection with the infeed and rejection stars 6 and 8 . It must be pointed out that labelling machines have a considerable throughput of containers so that, naturally, not only a single carrier element 9 but several carrier elements 9 are provided on which a container 4 each stands upright.
REFERENCE LIST
1 labelling machine
2 labelling carousel
3 labelling assembly
4 container
5 infeed side
6 infeed star
7 rejection side
8 rejection star
9 carrying element
10 first inspection unit
11 design feature
12 central control unit
13 control wire
14 control wire
15 second inspection unit
16 rejection device
17 control wire
18 label
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A method for operating a labelling machine includes, at a first inspection unit, detecting feature coordinates of a design feature of a container, transferring the feature coordinates to a second inspection unit that follows a labelling assembly, and at the second inspection unit, while synchronizing the feature coordinates of the design feature, inspecting the container for correct label seating by tracking the feature coordinates of the design feature along a conveying path from the first inspection unit to said second inspection unit.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a wear detection probe or sensor for a brake pad.
2. Description of the Related Art
Wear detection probes are known for detecting when a brake pad of an automotive vehicle has been worn to an operating limit or to a degree that it cannot be used any longer. The known wear detection probe is shown in FIG. 5, and is identified by the numeral 1 . The prior art probe 1 includes a detection wire 3 made integral to a resin holder 2 by insert molding. The detection wire 3 extends along an arrangement path through the holder 2 from its rear end to its front end. The detection wire 3 then is formed with a fold 3 R at the front end surface of the holder 2 and extends back to the rear end.
The prior art wear detection probe 1 is accommodated in a brake pad 5 such that the folded portion 3 R of the detection wire 3 faces a disk rotor 4 like a brake disk. As the wear of the brake pad 5 progresses, the wear detection probe 1 is exposed to a pad surface of the disk rotor 4 and, accordingly, the folded portion 3 R of the detection wire 3 starts to abrade. When the wear of the brake pad 5 reaches its operating limit, the detection wire 3 is cut and a warning lamp (not shown) signals that the wear of the brake pad 5 has reached its operating limit.
The prior art wear detection probe 1 thus constructed has a problem of high production costs because the detection wire 3 is made integral to the holder 2 by insert molding.
In view of this problem, an object of the present invention is to reduce production costs.
SUMMARY OF THE INVENTION
According to the invention, there is provided a wear detection probe for a braking element, in which a detection wire is arranged in a path which substantially folds the detection wire at the front or abrasion end of a holder and extends to the rear end of the holder. Thus, wear of the braking element to its operating limit is detected when the folded portion of the detection wire is cut by a rotor. The wear detection probe includes at least one arrangement groove formed in the holder to extend substantially from the rear end of the holder to the folded portion of the detection wire. The detection wire is fitted or inserted in the arrangement groove. The wear detection probe further includes a restricting means for preventing the detection wire from coming out of the arrangement groove.
Since the wear detection probe is assembled by fitting the detection wire in the arrangement groove of the singly formed holder, production costs can be reduced as compared with the prior art wear detection probe in which the holder and the detection wire are made integral to each other by insert molding.
According to a preferred embodiment, the arrangement groove of the path is substantially formed in the outer surface of the holder. Although the detection wire is arranged in an arrangement groove that opens to an outer surface of the holder, the restricting means prevents the detection wire from coming out of the arrangement groove. Accordingly, the detection wire remains in the arrangement groove.
According to a further preferred embodiment, there is provided a wear detection probe for a braking element, in which a detection wire is arranged in a path which folds the detection wire at the front end of the holder and extends to the rear end of the holder. Wear of the braking element to its operating limit is detected when the folded portion of the detection wire is cut by the rotor. The wear detection probe includes at least one arrangement groove which is formed in the outer surface of the holder. The arrangement groove extends from the rear end of the holder to the location specified for the folded portion of the detection wire. The wire is fitted in the arrangement groove(s), and a restricting means is provided for preventing the detection wire from coming out of the arrangement groove(s).
Preferably, two arrangement grooves are formed, and the restricting means comprises a rib projecting from the rear end surface of the holder in a position to partition two extending portions of the detection wire extending from the arrangement grooves. A slit preferably is formed in the rib and opens in the rear edge of the rib. A connecting member is fitted or fittable through or into the slit and is adapted to connect the two extending portions of the detection wire at the opposite sides of the rib.
The two extending portions of the detection wire extending from the arrangement grooves are engaged with the rib by fitting the connecting member in the slit. Since the slit is open in the rear edge of the rib which intersects with the outer surface of the holder, the connecting member will not be disengaged from the slit. This prevents the detection wire from coming out of the arrangement grooves.
Preferably, the connecting member comprises a heat shrinkable tube, a rubber tube and/or a tube made out of soft resin that is fitted or fittable at least partly on the extending portions of the detection wire corresponding to the slit. Accordingly, the detection wire easily can be prevented from coming out of the arrangement grooves.
The slit preferably extends at an angle different from 0° or 180°, and most preferably substantially normal to the two extending portions of the detection wire that extend from the arrangement grooves.
According to a further preferred embodiment, the path comprises at least one through hole for substantially communicating with two or more arrangement grooves. The through hole is arranged at an angle different from 0° or 180°, and preferably substantially normal to the arrangement grooves and/or normal to the longitudinal direction of the holder. Accordingly, since the arrangement path in which the detection wire is fitted or arranged preferably is bent, a displacement of the detection wire can be prevented securely.
The path may further comprises a communication groove, which is open in the upper outer surface of the holder and which communicates between the upper sides of the through holes.
Further preferably, the folded portion is arranged substantially parallel to the front or abrasion end of the braking element and in a direction substantially normal to an axis of rotation of the rotor.
Most preferably, one or more extending portions of the detection wire extending from the one or more arrangement grooves are arranged at one or more heights being which are different from portions of the detection wire which are arranged in the arrangement grooves.
These and other objects, features and advantages of the present invention will become more apparent upon a reading of the following detailed description and accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of a wear detection probe according to a first embodiment of the invention.
FIG. 2 is a section of the wear detection probe in its mounted state.
FIG. 3 is a rear view of the wear detection probe without a detection wire.
FIG. 4 is a rear view of the wear detection probe with the detection wire assembled.
FIG. 5 is a section of a prior art wear detection probe.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Hereafter, one embodiment of the invention applied to a known disk brake of an automotive vehicle is described with reference to FIGS. 1 to 4 . This disk brake is comprised of a brake lining member B (braking element) for pressing the opposite surfaces of a disk-shaped rotor R which is integrally rotated with an unillustrated wheel. The disk brake further compromises a support member S to which the braking lining member B is fixed. The support member S and the brake lining member B are formed with mount holes Sh, Bh which are substantially aligned with each other. A wear detection probe or sensor P, according to this embodiment, is mounted or mountable in these mount holes Sh, Bh.
The wear detection probe P is comprised of a holder 10 and a known detection wire 20 obtained e.g. by resin-coating a metal braided wire.
The holder 10 is made of a heat resistant resin material and is an integral or unitary assembly of a cylindrical portion 11 , an enlarged portion 12 and a rib 13 . The enlarged portion 12 is substantially continuous with the rear end of the cylindrical portion 11 and is substantially concentric with the cylindrical portion 12 . The rib 13 preferably is in the form of a substantially rectangular plate and projects from the rear end of the enlarged portion 12 . An arrangement path for arranging the detection wire 20 is formed in the cylindrical portion 11 and the enlarged portion 12 .
The arrangement path includes two through holes 15 F, 15 R which extend in a direction at an angle different from 0° or 180°, preferably substantially normal to the longitudinal direction of the holder 10 at the front end of the holder 10 . A communication groove 16 is open in the (upper) outer surface of the cylindrical portion 11 and substantially communicates between the (upper) sides of the through holes 15 F, 15 R. Two arrangement grooves 17 L, 17 R are substantially open in the (lower) outer surfaces of the cylindrical portion 11 and the enlarged portion 12 . The arrangement grooves 17 L and 17 R individually extend backward from the lower openings of the through holes 15 F, 15 R, and are substantially open in the rear end surface of the enlarged portion 12 . The detection wire 20 is arranged in the right arrangement groove 17 R, the front through hole 15 F, the communication groove 16 , the rear through hole 15 R and the left arrangement groove 17 L in this order. It should be appreciated that the inner diameter and the width of the arrangement path are set substantially equal to the outer diameter of the resin coating of the detection wire 20 .
FIG. 2 is a section along the left arrangement groove 17 L which communicates with the rear (right in FIG. 2) through hole 15 R. The orientation of the wear detection probe P in FIG. 2 is laterally opposite from that in FIG. 1 . Accordingly, although the right arrangement groove 17 R is seen to be located more forward than the left arrangement groove 17 L in FIG. 1, the right arrangement groove 17 R cannot be seen in FIG. 2 in which the left arrangement groove 17 L is shown because it is located behind the left arrangement groove 17 L.
To mount the detection wire 20 in the arrangement path, the ends of the folded detection wire 20 are inserted through or into the front and rear through holes 15 F, 15 R from above the holder 10 . A portion of the detection wire 20 that comes out of the front through hole 15 F is fitted in the right arrangement groove 17 R. A portion of the detection wire 20 that comes out of the rear through hole 15 R is fitted in the left arrangement groove 17 L. The portion of the detection wire 20 located in the front through hole 15 F serves as a folded portion 20 R. When the wear of the brake lining member B reaches its operating limit, the folded portion 20 R is abraded with the front end of the cylindrical portion 11 to be consequently cut. Extending portions 20 S of the detection wire 20 are exposed from the rear ends of the arrangement grooves 17 L, 17 R and extend backwardly along the left and right surfaces of the rib 13 . The extending portions 20 are secured to an unillustrated terminal fitting and connected with an unillustrated breakage detecting circuit via a connector. Preferably, the extending portions 20 S are arranged at a height or position which is substantially different from or offset from the portions of the detection wire 20 in the arrangement grooves 17 L, 17 R. In other words, the extending portions 20 S are located below and/or above the portions of the detection wire 20 in the arrangement grooves 17 L, 17 R.
The wear detection probe P is mounted by a pair of mount pins 18 which project from the outer surface of the enlarged portion 12 such that the enlarged portion 12 and the rib 13 are accommodated in the mount hole Sh of the support member S and such that the cylindrical portion 11 is accommodated in the mount hole Bh of the brake lining member B. In this mounted state, the front end of the holder 10 faces the rotor R. At this time, the folded portion 20 R of the detection wire 20 extends in the vertical direction of FIG. 2 which is substantially same as the rotating direction of the rotor R or a tangential direction of the rotor R with respect to its axis of rotation. When the thickness of the brake lining member B is reduced to a specified degree as the wear thereof progresses, the front end of the wear detection probe P and the folded portion 20 R are abraded by the contact with the rotor R and, consequently, the detection wire 20 is cut. In this way, it is detected that the wear of the brake lining member B has reached its operating limit.
The holder 10 of this embodiment is provided with a restricting means 25 for preventing the detection wire 20 from coming out of the arrangement grooves 17 L, 17 R. This restricting means 25 preferably is comprised of the rib 13 , a slit 19 formed in the rib 13 and a heat-shrinkable tubing 26 (connecting member).
The rib 13 is arranged to partition the two extending portions 20 S of the detection wire 20 that extend from the arrangement grooves 17 L, 17 R. Thus the extending portions 20 S extend along opposite surfaces of the rib 13 . The slit 19 is formed to be open in the rear end of the rib 13 and extend along forward and backward or longitudinal directions. The heat-shrinkable tubing 26 is fitted to surround the two extending portions 20 S together after the detection wire 20 is arranged in the holder 10 . An end of the heat-shrinkable tubing 26 toward the holder 10 is deformed or treated to be held in the slit 19 , and the heat-shrinkable tubing 26 is heated in this state. Then, the heat-shrinkable tubing 26 is so deformed as to reduce its diameter and is adhered to both extending portions 20 S. In this way, the heat-shrinkable tubing 26 and the detection wire 20 are made substantially integral to each other.
In this state, the flat heat-shrinkable tubing 26 extends substantially horizontally or transversely in the slit 19 as shown in FIG. 4 . In front of the slit 19 , loose lateral movements of the two extending portions 20 S split on the opposite sides of the rib 13 are restricted by the contact with the rib 13 . Accordingly, the heat-shrinkable tubing 26 integral to the extending portions 20 S cannot laterally move to come out of the slit 19 . Loose vertical movements of the extending portions 20 S (or movements thereof substantially in the plane of the rib 13 ) are restricted by the engagement of the heat-shrinkable tubing 26 and the slit 19 . In other words, this prevents the detection wire 20 from coming down out of the arrangement grooves 17 L, 17 R.
Since the wear detection probe P according to this embodiment is of the type in which the detection wire 20 is fitted in the arrangement path of the singly formed holder 10 , production costs are lower than the prior art wear detection probe in which the holder and the detection wire are made integral to each other by insert molding.
Although the detection wire 20 merely is fitted or inserted in the arrangement grooves 17 L, 17 R which are open in the outer surface of the holder 10 , the detection wire 20 does not come out of the arrangement grooves 17 L, 17 R because the loose vertical movement of the detection wire 20 is restricted by fitting the heat-shrinkable tubing 26 integrally mounted on the detection wire 20 in the slit 19 .
Further, since the arrangement path in which the detection wire 20 is fitted is bent, a displacement of the detection wire 20 can be prevented securely even if a pulling force acts on only one of the two extending portions 20 S of the detection wire 20 in a backward direction.
Furthermore, since the two through holes 15 F, 15 R are so formed as to extend in a direction at an angle different from 0° or 180°, preferably substantially normal to the acting direction of the pulling force, the displacement of the detection wire 20 caused by the pulling force can be prevented more effectively as compared with the case where only one through hole is provided.
The through holes 15 F, 15 R of the arrangement path are short because they extend in a transverse direction of the holder 10 . Thus the detection wire 20 is less likely to buckle and/or get caught during the insertion as compared with a case where the through holes 15 F, 15 R extend in the longitudinal direction of the holder 10 . Further, since the arrangement grooves 17 L, 17 R extending in the longitudinal direction of the holder 10 are open in the outer surface of the holder 10 , the detection wire 20 can be fitted or arranged easily. In other words, the detection wire 20 easily can be arranged in the arrangement path.
The present invention is not limited to the described and illustrated embodiment, but the following embodiments are also embraced by the technical scope of the present invention as defined in the claims.
Although the two arrangement grooves are exposed in the outer surface of the holder in the foregoing embodiment, only one arrangement groove may be exposed in the outer surface of the holder while the other may be formed inside the holder according to the invention.
Although the heat-shrinkable tubing is used as a connecting member in the foregoing embodiment, a rubber tube, a tube made of a soft resin or the like may be used according to the invention.
Although the restricting means is comprised of the rib, the slit and the connecting member in the foregoing embodiment, it may be an other means, such as taping, to cover the arrangement grooves according to the invention.
Although the two arrangement grooves are both located below the slit (or at a height that is not flush with or corresponding to the slit) in the foregoing embodiment, one arrangement groove may be located below the slit while the other may be located above the slit.
Although the folded portion of the detection wire is accommodated in the holder in the foregoing embodiment, the invention is also applicable to a case where the folded portion of the detection wire is exposed at the front end surface of the holder.
Besides the preceding embodiments, a variety of other changes can be made without departing from the scope and spirit of the invention as defined in the claims.
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A wear detection probe for a braking element includes a holder with opposed front and rear ends. A portion of the holder near the front end is configured to retain a detection wire. Thus, after sufficient wear of the brake and the holder, the detection wire will be broken to produce a signal indicative of brake wear. The holder includes two arrangement grooves extending from the abradeable portion of the detection wire to the rear end of the holder. The wear detection probe further includes a rib. The extreme rear end of the rib may include a slot, and a heat shrinkable tube may surround the wires and engage partly in the slot.
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This is a division, of application Ser. No. 688,371 filed Jan. 2, 1985 U.S. Pat. No. 4,556,681.
This invention relates to a method for producing foamed polycarbonate articles and to foamable polycarbonate resins suitable therefor. More particularly, this invention relates to a method for producing foamed polycarbonate articles which method eliminates or reduces the necessity for drying the polycarbonate resin before the foaming and shaping step.
BACKGROUND
Foamed thermoplastic resins are finding increasing utility in the manufacture of a wide range of articles. Polycarbonate thermoplastic resins are suitable for foaming and may be used to produce foamed articles with the excellent physical properties generally associated with this thermoplastic resin. However, foamed articles are often very large in comparison to many injection molded or extruded articles and generally utilize methods of manufacture with extremely short cycle times and high throughput rates. In the case of polycarbonate, which is moisture sensitive at processing temperatures, the high throughput rates place a load on drying equipment which for many molders and extruders of thermoplastic resins is beyond the capacity of their equipment. Insufficient drying of the polycarbonate resin before melt processing results in hydrolysis of the resin and lower average molecular weights. Foamed articles produced from insufficiently dried polycarbonate resin exhibit reduced tensile strength, flexural strength, flexural modulus, deflection temperature, and falling ball impact strength.
Polycarbonate resins containing epoxy compounds as stabilizers are well known. U.S. Pat. No. 3,489,716, Calkins, et al., assigned to the same assignee as the present invention discloses a cycloaliphatic epoxy containing 1-2 cycloaliphatic rings in a polycarbonate resin as a heat and color stabilizer. These epoxies of Calkins, et al., have been used in the past by the assignee of the present invention in foam grade polycarbonate blends for commercial sale, but in amounts of 0.1% by weight of the blend and less.
U.S. Pat. No. 3,634,312, Babillis, et al., assigned to the same assignee as the present invention discloses the use of epoxy compounds as thermal stabilizers for copolycarbonate/phosphite compositions. U.S. Pat No. 3,839,247, Bialous, et al., assigned to the same assignee as the present invention, discloses aromatic epoxies, aliphatic epoxies, or mixtures thereof in combination with polycarbonate resin to prevent hazing and brittleness in the resin when subsequently subjected to elevated temperatures and moisture.
Therefore, it is an object of the present invention to produce foamed polycarbonate materials from undried resin having improved physical properties, particularly Izod impact strength.
It is yet another object of the present invention to produce foamable grades of polycarbonate resin which require little or no drying before foaming.
It is yet another object of the present invention to reduce or eliminate the necessity of drying polycarbonate resins before foaming.
DETAILED DESCRIPTION OF THE INVENTION
Briefly, according to the present invention, foamed polycarbonate articles may be made by a method which includes the step of foaming a polycarbonate resin composition containing from about 0.2% to about 1.0% by weight an aromatic, aliphatic, or cycloaliphatic epoxy compound. The presence of such epoxy compound allows for the elimination or reduction in severity of a heretofore necessary drying step.
Any of the usual polycarbonate resins are suitable for use in the polycarbonate resin composition mentioned herein. These resins include but are not limited to those described in U.S. Pat. Nos. 3,161,615; 3,220,973; 3,312,659; 3,312,660; 3,313,777; 3,666,614; among others all of which are incorporated herein by reference. Preferred polycarbonate resins are the aromatic polycarbonate resins of the dihydric phenols, particularly those of bisphenol-A. A preferred BPA-polycarbonate is referred to commercially as LEXAN® polycarbonate resin, a trademark of the General Electric Company.
Other thermoplastic resins may be blended with polycarbonate resin to form the polycarbonate resin composition. These thermoplastic materials which may also be present include acrylic and methacrylic polymers, polyethermides, phenylene oxide based resins such as polyphenylene oxide and blends of polyphenylene oxide and styrene resins; polyaryl ethers; polyesters; polyethylene; polyphenylene sulfides; polypropylene; polysulfones; ethylene polymers such as ethyl vinyl acetates; and necessary compatibilizers.
Epoxy functionalized materials suitable for use in the polycarbonate resin composition are aliphatic, cycloaliphatic and aromatic epoxy functionalized materials or mixtures thereof. Of the aromatic epoxies that are employed, they can be either the aromatic glycidyl ether or the aromatic glycidyl ethers containing 1 to 3 rings or they may be polyepoxides, i.e., aromatic polyglycidyl ethers containing 1 to 3 aromatic rings. Of the aliphatic epoxies, they may be best represented by the following formula: ##STR1## wherein R 5 is hydrogen or methyl and R 3 and R 4 are independently selected from hydrogen or alkyl radicals of 1 to 24 carbon atoms and n is an integer of from 1 to about 10. Of the cycloaliphatic epoxies, they can be either the cycloaliphatic-aliphatic glycidyl ethers or esters, or cycloaliphatic epoxies made by the epoxidation of cycloolefins with peracetic acid. Preferably, the cycloaliphatic epoxies contain 1-2 cycloaliphatic rings.
Specifically, the epoxies that can be employed herein are glycidol, bisphenol-A diglycidyl ether, tetrabromobisphenol-A diglycidyl ether, diglycidyl ester of phthalic acid, diglycidyl ester of hexahydrophthalic acid, epoxidized soybean oil, butadiene diepoxide, tetraphenylethylene epoxide, octyl epoxy tallate, dicyclopentadiene dioxide, vinylcyclohexene dioxide, bis (3,4-epoxy-6-methylcyclohexylmethyl) adipate, and 3,4-epoxycyclohexylmethyl-3,4-epoxycyclohexane carboxylate. Preferably, the epoxy compound employed in the practice of this invention is bisphenol-A diglycidyl ether.
Suitable epoxy functionalized materials are available from Dow Chemical Company under the tradename DER-332, from Shell Oil Corporation under the tradenames Epon 826, 828, and 871 and from Ciba-Giegy Corporation under the tradenames CY-182 and CY-183.
The epoxy functionalized materials are added to the polycarbonate resin composition in amounts effective to retain the Izod impact strength of the polycarbonate resin foam in spite of an otherwise insufficient drying step prior to the foaming step. A person skilled in the art may determine the optimum amount for any given epoxy functionalized material. Generally, the epoxy functionalized material should be added to the polycarbonate resin composition in a percent by weight ranging from about 0.2% to about 1.0% of the total polycarbonate resin composition. Preferably, the percent by weight is from about 0.3% to about 0.7% epoxy functionalized material.
Preferred polycarbonate resin compositions contain a reinforcing filler or agent. In general, any reinforcing filler can be used including metals, e.g., aluminum, iron, or nickel and the like and non-metals, e.g., carbon filaments, silicates, such as acicular calcium silicate, asbestos, TiO 2 , potassium titanate and titanate whiskers, wollastonite, glass flakes and fibers and the like. It is to be understood that unless the filler adds to the strength and stiffness of the composition, it is only a filler and not a reinforcing filler as contemplated herein. In particular, the reinforcing fillers increase the flexural strength, the flexural modulus, the tensile strength, and the heat distortion temperature. Although it is only necessary to have at least a reinforcing amount of the reinforcing filler present, in general, the reinforcing filler may be added to the polycarbonate resin composition in a ratio to the total thermoplastic resin present of from about 1/99 to about 9/1.
In particular, the preferred reinforcing fillers are of glass, and it is preferred to use fibrous glass filaments comprised of lime-aluminum borosilicate glass that is relatively soda free. This is know as "E" glass. However, other glasses are useful where electrical properties are not so important, e.g., the low soda glass known as "C" glass. The filaments are made by standard processes; e.g., by stream or air blowing, flame blowing, and mechanical pulling. The preferred filaments for plastics reinforcement are made by mechanical pulling. The filament diameters range from about 0.000112 to 0.00075 inch, but this is not critical to the present invention.
The length of the glass filaments and whether or not they are bundled into fibers and the fibers bundled in turn to yarns, ropes, or rovings, or woven into mats and the like are also not critical to the invention. In preparing the present compositions, it is convenient to use the filamentous glass in the form of chopped strands of from about 1/8 inch to about 1 inch long, preferably less than 1/4 inch long. However, even shorter lengths will be encountered because during compounding, considerable fragmentation will occur.
In general, best properties will be obtained if the sized filamentous glass reinforcement is added to the polycarbonate resin composition in a weight ratio to the total thermoplastic resin present of from about 1/99 to about 2/3. For direct molding or extruding use, it will be readily apparent to one skilled in the art at what composition the glass will cause flow problems. However, it is useful also to prepare polycarbonate resin compositions containing substantially greater quantities of glass and custom blending with resins that are not glass reinforced to provide any desired glass content of a lower value.
The polycarbonate resin compositions of the present invention may contain flame retardant additives. Useful flame retardant additives comprise a family of chemical compounds well known to those skilled in the art. Generally speaking, the more important of these compounds contain chemical elements employed for their ability to impart flame resistance, e.g., bromine, chlorine, antimony, and nitrogen. It is preferred that the flame-retardant additive comprise a halogenated organic compound (brominated or chlorinated); a halogen-containing organic compound in admixture with antimony oxide, elemental phosphorus compounds; a halogen-containing compound in admixture with a phosphorus compound or compounds containing phosphorus-nitrogen bonds.
Among the preferred halogen-containing compounds are the diaromatics of which the following are representative:
2,2-bis(3,5-dichlorophenyl) propane
bis-(2,chlorophenyl) methane
bis-(2,6-dibromophenyl) methane
1,1-bis(4-iodophenyl) ethane
1,2-bis-(2,6-dichlorophenyl)ethane
1,1-bis(2-chloro-4-iodophenyl) ethane
1,1-bis(2-chloro-4-methylphenyl) ethane
1,1-bis-(3,5-dichlorophenyl)ethane
2,2-bis-(3-phenyl-4-bromophenyl) ethane
2,3-bis-(4,6-dichloronaphthyl)-ethane
2,2-bis-(2,6-dichlorophenyl) pentane
2,2-bis-(3,5-dichlorophenyl) hexane
bis-(4-chlorophenyl) phenylmethane
bis-(3,5-dichlorophenyl) cyclohexylmethane
bis-(3-nitro-4-bromophenyl) methane
bis-(4-hydroxy-2,6-dichloro-3-methoxyphenyl) methane
2,2-bis-(3,5-dichloro-4-hydroxyphenyl) propane
2,2-bis-(3-bromo-4-hyroxyphenyl) propane
2,2-bis-(3,5-dibromo-4-hydroxyphenyl) propane Also preferred are the substituted benzenes exemplified by tetrabromobenzene, hexachlorobenzene, hexabromobenzene, and the biphenyls such as 2,2'-dichlorobiphenyl, 2,4'-dibromobiphenyl, 2,4'-dichlorobiphenyl, hexabromobiphenyl, octabromobiphenyl, decabromobiphenyl and halogenated diphenyl ethers, containing 2 to 10 halogen atoms.
The amount of the flame retardant additive used is not critical to the invention, so long as it is present in a minor proportion based on the total resin content of the polycarbonate resin composition--major proportions will detract from physical properties--but at least sufficient to render the polycarbonate resin composition non-burning or self-extinguishing. Those skilled in the art are well aware that the amount will vary with the nature of the polymers in the blend and with the efficiency of the additive.
The polycarbonate resin composition may additionally contain a phosphorus containing compound as a color stabilizer. Generally, phosphites are used for this purpose at a weight percent in the total polycarbonate resin composition of about 0.05%. Commonly, an epoxy functional material is added along with the phosphorus containing compound as a secondary stabilizer to scavenge the phosphorus containing compound by-products.
The polycarbonate resin composition may also contain other active or inactive fillers and additives including carbon black; chalk; antioxidants; stabilizers, such as salts of lead, cadmium, calcium, zinc, tin, or barium, waxes; dyes; pigments; impact modifiers; zinc oxides; etc.
The above polycarbonate resin composition may be expanded from a granular or bead form to assume a porous cellular, solidified structure by the action of various propellants or agents for expanding or blowing the materials. The blowing agents, in accordance with common practice, are usually gases, gas generating solids, or highly fugacious liquids which have been dissolved or otherwise intimately incorporated within the thermoplastic resinous material either at the extrusion or die head while the resinous material is in melt form or while the resinous material is in unexpanded granular form. Thus, the polycarbonate resin composition may not come into contact with a blowing agent until just prior to the instant of foaming.
The blowing agents suitable for use in or with the polycarbonate resin composition include gases which expand upon the release of pressure to foam the resin composition, liquids which will vaporize to a gas and expand the resin upon the release of pressure, solids which decompose to release a gas, and combinations of such gases, liquids, and solids. Examples of suitable normally gaseous agents which can be used are paraffins such as propane or butane and more permanent gases such as nitrogen, carbon dioxide, and air. Similarly, olefins such as ethylene, propylene, butylene, etc., and mixtures thereof can be used to advantage. Suitable normally liquid blowing agents include methyl chloride, higher paraffins such as pentane or hexane, freons, etc. Examples of suitable solids which upon decomposition release a gas are ammonium or azo type compounds, such as ammonium carbonate, ammonium bicarbonate, potassium bicarbonate, diazoaminobenzene, diazoaminotoluene, azodicarbonamide, diazoisobutyronitrile, etc. The amount of foaming agent used depends upon the volume of gas it will generate and the foam density required.
The foaming agent may be combined with the polycarbonate resin composition either prior to or at the instant of the actual foaming of the resin in an amount sufficient to result in the desired degree of foaming. Preferably, the foaming agent is premixed with the polycarbonate resin composition while in granular or particulate form and activated by the application of heat to the resin particles.
The polycarbonate resin composition may be foamed by any of the common techniques in either an injection molding or extrusion operation. Generally, such techniques involve heating the polycarbonate resin composition until it is in melt form and injecting the melt into a die cavity or extruding the melt through a die head with an activated blowing agent. One skilled in such techniques can easily prescribe more specific methods and conditions for foaming the polycarbonate resin composition.
Due to the presence of the epoxy functionalized material, the need for drying the polycarbonate resin composition prior to foaming is reduced or eliminated. It is normally required that the water content of polycarbonate resin containing compositions be reduced to about 0.02% by weight or less before foaming to avoid drastic reduction of Izod impact strength. Preferably, the water content is reduced to as low as possible. Under the present invention, the epoxy functionalized materials improve the Izod impact strength of foamed, water containing polycarbonate resins. In some cases, this may eliminate the need for drying the resin altogether. In any case, the adverse effects of otherwise insufficient drying will be reduced or eliminated.
PREFERRED EMBODIMENT OF THE INVENTION
Thus has been described a method for foaming polycarbonate resin containing compositions wherein the need for drying the polycarbonate resin composition is reduced or eliminated. In order to more fully and clearly illustrate the invention, the following specific examples are presented. It is intended that the examples be considered as illustrative of rather than limiting to the invention disclosed and claimed herein.
EXAMPLE 1
Polycarbonate resin was dry blended with 5% by weight glass fibers, stabilizers, and various amounts of epoxy functionalized materials. The resin compositions were extruded and comminuted into pellets having an equilibrium water content established through conditioning for 150 hours at room temperature and various relative humidities. The water content of the pellets was found to be roughly linear as a function of relative humidity between (0,0) and (100, 0.35 wt %). To each 100 parts by weight polycarbonate resin pellets was dry blended 0.1% by weight 5-phenyl tetrazole, a blowing agent to form a pellet powder mix for injection molding. The wet pellet powder mixes were thereafter foam injection molded without a drying step into test bars to determine unnotched Izod Impact Strength (ASTM D256).
EXAMPLE 2
Example 1 was followed wherein the amounts shown below of DER-332, a bisphenol-A diglycidyl ether made by Dow Chemical Company, were used as the epoxy functionalized material and the resin pellets were conditioned at 92% RH.
______________________________________92% Relative HumidityPolycarbonate Resin Unnotched IzodComposition Weight Impact Strength% Epoxy ft. lbs./in.______________________________________0 1.90.2 2.60.5 3.21.0 1.92.0 1.95.0 1.5______________________________________
EXAMPLE 3
Example 1 was followed wherein the amounts shown below of DER-332 were used as the epoxy functionalized material and the resin pellets were conditioned at 69.2% RH.
______________________________________69.2% Relative HumidityPolycarbonate Resin Unnotched IzodComposition Weight Impact Strength% Epoxy ft. lbs./in.______________________________________0 1.20.3 1.50.4 2.40.5 1.70.6 2.50.7 2.2______________________________________
EXAMPLE 4
Example 1 was followed wherein the amounts shown below of DER-332 were used as the epoxy functionalized material and the resin pellets were conditioned at 58% RH.
______________________________________58% Relative HumidityPolycarbonate Resin Unnotched IzodComposition Weight Impact Strength% Epoxy ft. lbs./in.______________________________________0 3.90.3 5.40.5 5.90.7 3.5______________________________________
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Epoxy compounds are added to polycarbonate resin to reduce or eliminate the necessity of drying the resin prior to a foaming process.
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CROSS REFERENCE TO RELATED APPLICATION
This application is a continuation-in-part of my copending application Ser. No. 486,168, filed July 5, 1974, now Pat. No. 3,960,482 for a Durable Press Process and is also continuation-in-part of my copending application Ser. No. 524,770 filed Nov. 18, 1974, now U.S. Patent No. 3,960,483 also for a Durable Press Process.
BACKGROUND OF THE INVENTION
1. Field of the Invention:
This invention relates to a durable press process for cellulosic fiber-containing fabrics and more particularly to a process which utilizes formaldehyde and a catalyst to impart wrinkle resistance to cellulosic fiber-containing fabrics.
There have been a great many proposed processes in recent years for treating cellulosic fiber-containing products, such as cloth made of cotton or cotton blends, with formaldehyde to provide durable cross-linking of the cellulosic molecules and to thereby impart durable crease resistance and smooth drying characteristics to the goods. However, problems have been encountered, and although a number of the processes have been operated commercially there is a great need for improvement.
As pointed out in U.S. Pat. No. 3,706,526, granted Dec. 19, 1972, the processes have tended to lack reproducibility, since control of the formaldehyde cross-linking reaction has been difficult. The process of this patent is said to solve the control problem by controlling moisture present in the cellulosic material during the reaction. The cellulosic material is conditioned to give to a moisture content of between about 4 to 20%, preferably 5 to 12%, based on the dry weight of the cellulose fiber, and it is then introduced into a gaseous atmosphere containing water vapor, a cellulose cross-linking amount of formaldehyde (e.g. 15 to 60 volume percent) and a catalytic amount of sulfur dioxide.
Canadian Pat. No. 897,363, granted Apr. 11, 1972, discloses a process for the formaldehyde cure of cellulosic fibers which comprises applying to the cellulosic material, a solution of zinc chloride, ammonium chloride, phosphoric acid or zinc nitrate, conditioning the fabric to a moisture content of between about 7 and 15 based on the dry weight of the fabric, and thereafter exposing the catalyst-containing fabric or article made therefrom to an atmosphere of formaldehyde or formaldehyde vapor (5 to 75% volume percent) at a temperature of between about 90° and 150° C.
The process requires precise moisture control and is said to be limited to the use of the few select catlysts.
Accordingly, a need exists for a simple and economical durable press process which does not depend on precise moisture control to moderate the cross-linking and does not require high concentrations of formaldehyde.
SUMMARY OF THE INVENTION
The present invention takes advantage of the observation that the cross-linking of cellulosic fibers with formaldehyde vapors takes place most readily when the fibers are in a moisture swollen condition. This is accomplished by introducing the fibers into a formaldehyde vapor treating chamber while they contain over 20% by weight of moisture, based on the dry weight of the fibers and, preferably, when over 60% by weight of moisture is present. Under these conditions the concentration of formaldehyde in the vapor treating chamber and amount of formaldehyde added can be kept to a minimum. Control of the reaction is accomplished by impregnating the cellulosic material with that amount of a catalyst which will produce the desired amount of cross-linking under the curing conditions used.
One object of this invention is to provide a durable press process which produces fabrics having high crease retention and excellent wash appearance with acceptable tensile strength.
Another object of the invention is to provide a formaldehyde vapor treating process in which the formaldehyde concentration in the vapor treating chamber can be kept at a low value, thereby reducing explosion and fire hazards.
Yet another object is to provide a durable press treatment process which requires a relatively small amount of formaldehyde thereby significantly reducing the amount of excess formaldehyde found on the garment after treatment and thus substantially reducing the washing and steam cleaning required by the known processes.
Still another object of the invention is to provide a durable press process which enables the control of the catalysts present and avoids limitation upon use of water as the moderator of the reaction.
DETAILED DESCRIPTION OF THE INVENTION
The process of the invention comprises increasing the moisture content of a cellulosic fiber-containing fabric to above 20% by weight so that the fibers are substantially completely swollen in the presence of a catalyst and then introducing the fabric into formaldehyde vapors in a treating chamber and curing to improve the wrinkle resistance of the fabric. The fabric may be impregnated with an aqueous solution of the catalyst and then treated with formaldehyde vapors.
The invention does not use limited amounts of moisture to control the cross-linking reaction since the cross-linking reaction is most efficient in the most highly swollen state of the cellulose fiber. The relatively high amount of water present allows more efficient conversion of formaldehyde to the hydrate which is the cross-linker. Thus, optimum results can be obtained with much less formaldehyde.
During the cross-linking reaciton at the curing stage, moisture is given up from the fabric as the cross-linking occurs, resulting in a decrease in the moisture content of the fabric. In fabrics having a moisture content of 20% or less, this tends to lower the effectiveness of the cross-linking reaction requiring higher concentrations of formaldehyde. In the process of the present invention, moisture is given up from a high level, that is, greater than 20% preferably greater than 30%, e.g., from 60-100% or more, and the cross-linking is optimized. Moisture which is so difficult to control, is not a problem in the present invention which only requires that the moisture content be above 20% which is simple to insure. Of course, water is not allowed to be present in so much of an excess as to cause the catalyst to migrate on the fabric.
The necessary moisture may be applied to the fabric by any conventional technique. It may be added separately or in the form of an aqueous solution of the selected catalyst, as by padding, fogging, spraying or the like. A fog spray will achieve high moisture content in a very short time. In addition, water spray or fog insures uniform moisturization.
In the present process, the amount of catalyst used controls the cross-linking. Preferably, an aqueous solution of the catalyst is padded onto the fabric so as to supply both the catalyst and the moisture in one operation. Of course, a spray technique could also be used.
As disclosed in copending application Ser. No. 524,770, alkylsulfonic acid catalysts may be used in the high moisture process since the cross-linking is optimized by the high moisture content and fully swollen condition of the fibers. While alkylsulfonic acids such as ethanesulfonic acid, give good results with acceptable whiteness, it has now been found that para-toluenesulfonic acid produces a fabric which is considerably whiter. Thus, the present invention relates to the use of arylsulfonic acids as catalysts in the high moisture content process. The arylsulfonic acid catalyst which is used is first dissolved in an aqueous solution and then applied to the fabric which is then treated with formaldehyde vapor to effect cross-linking.
The water soluble arylsulfonic acids which may be used as catalysts in the process of the present invention included toluene sulfonic acid, benzene sulfonic acid, naphthalene sulfonic acid and the halogen, hydroxy and nitro derivatives of these compounds, para-toluene sulfonic acid being particularly preferred.
For example, 4-chlorobenzene sulfonic acid, 3, 4 diamino benzene sulfonic acid, 4-ethyl-amino benzene sulfonic acid, 5-nitro toluene sulfonic acid, 8-hydroxynaphthalene sulfonic acid, 2-Naphthalene-5-nitroso-6-hydroxy sulfonic acid and 2-naphthalene-6-hydroxy sulfonic acid may be used.
The amount of catalyst may vary depending upon the particular type and the desired characteristic of the final fabric. However, in general the catalyst is incorporated in the fabric, on a dry weight basis, in an amount within the range of from 0.1% to about 10%, preferably about 0.1 to 1%.
The catalyst may be applied to the fabric from an aqueous solution by conventional techniques, preferably such as padding or spraying. The pH of the aqueous solution is of course in the acid range. Padding is the preferred method of application since the amount of solution applied can be carefully controlled.
The fabric may be continuously precured by first applying the aqueous catalyst solution to the fabric, adding additional moisture if necessary, and then exposing the fabric to formaldehyde vapors.
The concentration of the catalyst solution may be such as to supply with the catalyst that amount of water necessary to fully swell the cellulose fibers without further addition to moisture. Exposure to the formaldehyde vapors in this case is usually substantially immediately after the catalyst is applied to the fabric. Only two process steps are necessary, application of catalyst solution and treatment with formaldehyde vapors at the proper curing temperature. Of course, the fabric may be first formed into a garment and then impregnated with an aqueous solution of the acid catalyst followed by exposure to formaldehyde vapors. Again, the aqueous catalyst solution must contain sufficient water to fully swell the cellulose fibers or moisture must be added.
As indicated, the high moisture content in the fabric fully swells the cellulose fibers and optimizes the cross-linking reaction thereby providing improved crease resistance. Accordingly, considerably less formaldehyde is required than in the known vapor processes. This results in a direct reduction in the cost of the process. Moreover, due to the lower concentration of formaldehyde required, less excess formaldehyde is found on the fabric after treatment and the extent to which washing or steam cleaning is required is minimized.
The formaldehyde concentration in the treatment chamber is from about 1.0% to about 6.5% by volume, preferably about 1.0% to 3.0%. The dry add-on by reaction of the formaldehyde with the fabric at this concentration is generally less than about 0.5%. At concentrations of formaldehyde below about 1% by volume in the treatment chamber the wash appearance and crease resistance become less satisfactory than desired. At concentrations of much above about 3% there is usually no significant increase in these properties.
The utilization of small concentrations of formaldehyde in the treating chamber significantly reduces the fire hazard presented by formaldehyde since formaldehyde tends to be explosive in concentrations of 7% by volume or above when mixed with air.
The curing temperature at which the final cross-linking takes place is in the range of from about 200° F. to about 250° F., preferably about 212° F. to 245° F. Advantageously, it should be at least about 230° F. to insure that there is sufficient cross-linking to provide the necessary wrinkle resistance in the fabric. While higher temperatures may be used, they detract from the economics of the system. Temperatures above 325° F., as conventionally employed in resin curing, do not improve the present process and may serve to degrade the fabric by the action of the catalyst. The formaldehyde treatment and curing may take place in the same treating chamber or in separate chambers or zones of the treating apparatus.
It is sometimes desirable, depending upon the desired characteristic of the fabric, to add to the fabric a polymeric resinous additive that is capable of forming a soft film. For example, such additives may be a latex or fine aqueous dispersion of polyethylene, various alkyl acrylate polymers, acrylonitrilebutadiene copolymers, deacetylated ethylene - vinyl acetate copolymers, polyurethanes and the like.
Such additives are well known to the art and generally commercially available in concentrated aqueous latex form. For use in the process of this invention, such a latex is diluted to provide about 1% to 3% polymer solids in the aqueous catalyst-containing padding bath before the fabric is treated therewith. However, it is not necessary or desirable to add monomers or formaldehyde binding agents.
As the cellulosic fiber-containing fabric which may be treated by the present process there can be employed various natural or artificial cellulosic fibers and mixtures thereof, such as cotton, linen, hemp, jute, ramie, sisal, rayons, e.g., regenerated cellulose (both viscose and cuprammonium). Other fibers which may be used in blends with one or more of the above-mentioned cellulosic fibers are, for example, polyamides (e.g., nylons), polyesters, acrylics (e.g., polyacrylonitrile), polyolefins, polyvinyl chloride, and polyvinylidene chloride. Such blends preferably include at least 35% to 40% by weight, and most preferably at least 50% to 60% by weight, of cotton or natural callulose fibers.
The fabric may be a resinated material but preferably it is unresinated; it may be knit, woven, non-woven, or otherwise constructed. It may be flat, creased, pleated, hemmed, or shaped prior to contact with the formaldehyde containing atmosphere. After processing, the formed crease-proof fabric will maintain the desired configuration substantially for the life of the article. In addition, the article will have an excellent wash appearance even after repeated washings.
The equipment necessary to carry out the process is very much simplified since moisture control is not used as the moderator for the reaction. The aqueous, acid catalyst may be applied by padding or spraying. Moisturization of the fabric, if additional moisture is necessary, may be carried out by passing the fabric through a fog of water before entering the reaction chamber. The fabric containing the latent catalyst may then be placed in a reaction chamber to which gaseous formaldehyde is supplied from any convenient source, e.g., a formaldehyde generator wherein formaldehyde vapor is produced by heating para-formaldehyde. The formaldhyde vapors are diluted with air or other gas to provide the desired concentration. Preferably, the formaldehyde is generated outside the chamber containing the fabric to reduce the fire hazard.
The reaction chamber is preferably one which can be heated to a sufficiently high temperature to insure that the cross-linking reaction takes place. The atmosphere in the reaction chamber is preferably a mixture containing from 1% to 6.5% formaldehyde gas by volume, diluted with air or an inert gas such as nitrogen. Higher concentrations of formaldehyde could be used but are not required by this process.
To contact the fabric with formaldehyde vapors any suitable means may be employed. For example a batch system utilizing a closed vessel or tube containing the gaseous formaldehyde or into which formaldehyde is introduced may be used. The catalyst-containing fabric may be placed in the treating vessel for the appropriate time. In the alternative, a dynamic or continuous system can be used such as one wherein a stream of formaldehyde vapor is passed through a closed elongated chamber through which the fabric is also passed at an appropriate rate, either concurrently or countercurrently relative to the formaldehyde vapor or gas mix. It is also possible to use combinations of the above, such as by passing a stream of formaldehyde containing gas over a stationary fabric.
Having generally described this invention, a further understanding can be obtained by reference to certain specific examples which are provided herein for purposes of illustration only and are not intended to be limiting unless otherwise specified.
EXAMPLE 1
The fabric was a 50/50 polyester cotton sheeting which was padded with an aqueous para-toulene sulfonic acid catalyst solution containing the amount of catalyst as indicated in the following Table 1 to provide about 100% pick-up. The amount of catalyst shown in Table 1 is solution concentration, which at 100% pick-up of solution by the fabric also corresponds to the amount of catalyst by weight incorporated into the fabric based on the dry weight of the fabric. In addition to the specified amount of catalyst, the catalyst solution contained 0.2% Triton X-100 wetting agent. The cellulose fibers of the cloth at the 100% pick-up of solution were swollen to their maximum extent. The samples, without drying, were then placed in a heating chamber into which vapors from an amount (about 10 grams) of paraformaldehyde calculated to provide about 3.06% by volume of formaldehyde were introduced. The samples were exposed to the formaldehyde vapors for several mintues at about 100° F. and were then heated to about 245° F. in the chamber atmosphere.
The samples were then removed from the chamber, washed and dried. The crease resistance (Wrinkle Recovery) was determined by A.A.T.C.C. Test Method 66-1968. All samples were very white in appearance. The results are set forth in Table 1.
TABLE 1______________________________________p-Tol- Crease Recovery Angleuene Dry WetSample Sulfonic Fill- Fill-No. Acid Warp ing W & F Warp ing W & F______________________________________1 0.2 143.3 145.7 289.0 156.0 155.7 311.72 0.3 150.0 150.7 300.7 159.0 157.7 316.73 0.4 151.7 152.3 304.0 157.3 156.3 313.64 0.5 150.3 151.0 301.3 155.7 154.7 310.4______________________________________
As can be seen from the table, excellent crease resistance were obtained. A crease resistance of 290 is considered good by current standards in the industry.
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The present invention relates to a durable press process for cellulosic fiber-containing fabrics which utilizes formaldehyde and an aryl sulfonic acid catalyst to impart wrinkle resistance to the fabric.
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CROSS-REFERENCE TO RELATED APPLICATIONS
The present application claims priority under 35 U.S.C. §119(a) of German Patent Application No. 10 2012 000 717.5 filed Jan. 14, 2012, the disclosure of which is expressly incorporated by reference herein in its entirety.
BACKGROUND OF THE INVENTION
1. Field of the Invention
Embodiments of the invention relate to a spring band clip with a curved annular clip band having a first end portion and a second end portion between which an overlap region is formed, which is radially spaced from the clip band.
Furthermore, embodiments of the invention relate to a tool to release such a spring band clip.
2. Discussion of Background Information
Known spring band clips are used, for example, to attach a hose to pipe fittings. The spring band clip must be expanded to enable it to be pushed onto the hose. The spring band clip then contracts due to its intrinsic pretension, which thus holds it on the hose and presses the hose radially onto the pipe fitting.
Hose clips are known. For example, in German Patent No. DE 10 2005 036 208 B4 a spring band clip is described having markings that serve, after installation, to indicate whether a spring band clip with the correct nominal dimensions has been used.
The required expansion of the spring band clip before the actual installation is often seen as problematic and time-consuming. The expansion of the spring band clip is carried out by pressing the two end portions towards each other, resulting in an increase in diameter of the spring band clip. The use of an additional clip to hold the two end portions at a reduced distance with respect to one another in order to keep the spring band clip in the expanded condition is known. Such a clip is normally removed from the end portions after installation. As a result, there is a risk that the clip may be lost, thus contributing to pollution of the environment. This is especially problematic if the spring band clip is used in connection with moving machinery and in confined spaces. Additional precautions must be taken to prevent loss of the clip.
SUMMARY OF THE EMBODIMENTS
Embodiments of the invention are directed to a spring band clip, which allows for easy installation.
According to embodiments, a spring band clip of the type mentioned includes a locking device, which is at least partially integrated into the first end portion. In this manner, the locking device can be locked in position when the spring band clip is in an expanded state.
Thus, an additional element to keep the spring band clip in the expanded state is not required. Instead, the spring band clip has an integrated locking device, which reduces the effort for the production of the spring band clip. This also means that there are no parts that can be lost during installation. In addition, no additional space needs to be made available to enable the use of the spring band clip in confined spaces. After releasing the locking device, the spring band clip automatically contracts because of its intrinsic pretension to complete the installation.
Preferably, the locking device has a latch bent radially inward from the first end portion and a latching hook, which is arranged on an outer side of the spring band clip. By bending out the latch from the first end portion, a part of the locking device can be produced without additional elements. The latch is first stamped out and then bent accordingly. A latching hook, which is arranged on the outer side of the spring band clip, can then transfer sufficient force to enable the spring band clip to be held securely in the expanded state.
It is particularly preferred that the latching hook is formed integrally with the spring band clip, and is bent radially outwards out of the spring band clip. The latching hook can then be stamped out like the latch and then bent over. The weight of the spring band clip according to the embodiments is not increased when compared to a spring band clip, which does not have the possibility of being held in the expanded state. Rather, the already existing material of the spring band clip is used to form the locking device. In this way, it is not possible to lose one of the elements of the locking device because the latch and the latching hook are formed integrally with the spring band clip. The stamping and bending represents a very inexpensive production step, so that the manufacturing cost of the spring band clip remains very low. The result is a very simple design with low space requirements for the spring band clip.
Preferably, the latch is directed away from the first end portion, such that the latching hook is directed towards the second portion. Such a design enables an automatic locking of the locking device when the spring band clip, for example, is expanded manually. The latch then first slides over the latching hook, which can be deformed radially inwards. Once the latch has been moved beyond the end of the latching hook, the latching hook comes into play so that a return movement of the latch is prevented by the hook. Rather, the orientation of the latching hook causes this to occur by the force exerted by the tendency of the spring band clip to return to a smaller diameter; a force which is transmitted from the latch to the latching hook. Thus, inadvertent release of the locking device is prevented.
It is particularly preferred that the latching hook is designed to be longer than the latch. In this way, the latching hook exhibits a higher elasticity than the latch. Thus, the deformation required for latching is reproduced in essence by the latching hook. This enables the necessary forces to be absorbed very well.
In an alternative embodiment, the latch is designed to be longer than the latching hook. The latch then exhibits a higher elasticity. Accordingly during locking, there is essentially a deformation of the latch. The deformation forces can thereby be absorbed well.
Advantageously, the latch has a contact area for the latching hook extending in the radial direction. Thus, there is a relatively well-defined expanded position of the spring band clip. The position of the contact area will then determine how far the spring band clip is expanded.
Preferably, the first end portion extends in the circumferential direction at least over an angular range in which the latching hook is formed. The latching hook is then protected by the first end portion against external influences. While the first end portion does not necessarily completely cover the latching hook in the axial direction, it can still protect the latching hook from external influences. In this way, it is also achieved that the outer contours of the spring band clip with the locking device do not change compared to a spring band clip without a locking device. This is especially desirable for many applications.
Preferably, the latch extends in the radial direction over approximately half of the distance between the first end portion and the clip band. Thus there is still sufficient space available between the latch and the clip band to guide the latching hook between them. Then the latching hook itself does not necessarily need to be deformed radially outwards.
Preferably, the latching hook can be deformed radially inwards by a release tool, which is inserted between the first end portion and the clip band. By using the release tool, the latching hook can be pressed inwards with respect to the clip band in a relatively simple manner, so that the latching hook can move through beneath the latch. This allows a reduction in the diameter of the spring clip band, thus ensuring a tight fit of the spring band clip. A corresponding release tool can be produced relatively easily and can be used universally for hose clips of any nominal diameters. The expense involved in making available a release tool is therefore relatively low.
Embodiments are directed to a release tool for releasing a locking device of the above-described spring band clip.
Embodiments of the invention are directed to a spring band clip that includes an annular curved clip band having a first end portion and a second end portion, which are arranged to form an overlapping region and which are spaced radially from the clip band. A locking device, at least partially integrated in the first end portion, is structured and arranged to lock the clip band in an expanded state.
According to embodiments, the locking device may include a latch bent radially inwards from the first end portion and a latching hook disposed on an outer side of the clip band. The latching hook can be integrally formed with the clip band and is bent radially outwards from the clip band. Further, the latch can be arranged to face away from the first end portion, while the latching hook is directed towards the second end portion. The latching hook can be longer than the latch. Moreover, the latch can have a contact area extending radially that is arranged to contact the latching hook. The first end portion can extend in a circumferential direction at least over an angular range in which the latching hook is formed. The latch can radially extend more than approximately one-half of the distance between the first end portion and the clip band. Further, the latching hook can be deformable radially inwards by a release tool insertable between the first end portion and the clip band.
Embodiments of the invention are directed to a release tool for releasing a locking device of the above-noted spring band clip.
In accordance with embodiments of the invention, the release tool can be structured for insertion between the first end portion and the clip band to deform the latching hook.
Embodiments are directed to a method of operating a spring band clip that includes an annular band having a first end portion and a second end portion arranged to form an overlapping region. The method includes moving the first end portion and the second end portion toward each other to radially expand the annular band, and engaging a latching hook radially extending from the annular band with a latch radially extending from the first end portion to lock the annular band in a radially expanded state.
According to embodiments, the method can further include inserting a tool between the annular band and the first end portion to move at least one of the latch and the latching hook away from the other, whereby the annular band radially compresses.
In accordance with still yet other embodiments of the present invention, the method can further include moving at least one of the latch and the latching hook away from the other, whereby the annular band radially compresses.
Other exemplary embodiments and advantages of the present invention may be ascertained by reviewing the present disclosure and the accompanying drawing.
BRIEF DESCRIPTION OF THE DRAWINGS
The present invention is further described in the detailed description which follows, in reference to the noted plurality of drawings by way of non-limiting examples of exemplary embodiments of the present invention, in which like reference numerals represent similar parts throughout the several views of the drawings, and wherein:
FIG. 1 shows a spring band clip in side view,
FIG. 2 shows a spatial representation of a spring band clip, and
FIG. 3 shows the spring band clip according to FIG. 2 in the released state.
DETAILED DESCRIPTION OF THE EMBODIMENTS
The particulars shown herein are by way of example and for purposes of illustrative discussion of the embodiments of the present invention only and are presented in the cause of providing what is believed to be the most useful and readily understood description of the principles and conceptual aspects of the present invention. In this regard, no attempt is made to show structural details of the present invention in more detail than is necessary for the fundamental understanding of the present invention, the description taken with the drawings making apparent to those skilled in the art how the several forms of the present invention may be embodied in practice.
FIG. 1 shows a spring band clip 1 having a curved annular clip band 2 . The clip band 2 has a first end portion 3 and a second end portion 4 , which are formed by the corresponding bent ends of the clip band 2 . Thus, the end portions 3 , 4 of the clip band 2 are radially spaced with respect to one another.
Between the end portions 3 , 4 , an overlap region 5 is formed in which two layers of the clip band 2 are arranged axially side by side. The overlap region 5 is increased when the spring band clip 1 assumes its nominal diameter, i.e., not in the expanded state shown in the Figure. Thus, the clip band 2 is provided with a pretension that radially draws together the spring band clip 1 .
To keep the spring band clip 1 in an expanded state, which allows for easier installation of the spring band clip 1 , the spring band clip 1 is provided with a locking device 6 . The locking device 6 is integrated in the spring band clip 1 , i.e., it is part of the spring band clip or the clip band 2 and the first end portion 3 .
The locking device 6 comprises a latch 7 which is bent radially inwards from the first end portion 3 . In addition, the locking device 6 comprises a latching hook 8 , which is bent out of the clip band 2 . Here, the latch 7 and the latching hook 8 are flexibly deformed so that they assume the positions shown in the figure in the unloaded state.
In order to compensate the axial offset between the first end portion 3 and the locking device 6 , the latch 7 and/or the latching hook 8 can be bent in the axial direction as well as in the radial direction. In particular, it is possible for the latch 7 to be embodied or formed as an extension to the first end portion 3 in the axial direction, which is then bent in the radial direction. It is advantageous if the latch 7 has a contact area for the latching hook 8 , which extends in radial direction. Thus, there is a defined contact area for the latching hook 8 .
The latch 7 extends in the radial direction approximately over half of the distance 1 between the first end portion 3 and the clip band 2 . While the contact surface of the latch 7 is large enough to securely engage with the latching hook 8 while, there is still sufficient space beneath the latch 7 to enable the latching hook 8 to pass between the latch 7 and the clip band 2 when the latching hook 8 is elastically deformed radially inwards for the release of the locking device 6 .
A release tool may be provided to deform the latching hook 8 , and thus to release the locking device 6 , by exerting a force in the circumferential direction and/or in the radial direction on the latching hook 8 , so that it is deformed radially inwards. This leads to a release of the locking device 6 , so that the spring band clip 1 can contract.
FIG. 2 shows the spring band clip 1 in a spatial representation. In contrast to the embodiment of the spring band clip 1 shown in FIG. 1 , in the embodiment according to FIG. 2 , the latch 7 is formed to be longer than the latching hook 8 , so that the latch 7 is more easily deformable then the latching hook 8 .
The spring band clip 1 in the representation in FIG. 2 is shown in the tensioned state, and thus has a relatively large inner diameter. A relative movement between the first end portion 3 and the second end portion 4 (i.e., away from each other) is prevented by the locking device 6 in that the latch 7 is latched behind the latching hook 8 . A slot 9 is provided to receive the second end portion 4 in the clip band 2 , whereby the end portion 4 is formed with a reduced axial width so that it can be received in the slot 9 . The overlap region 5 is thus formed about the slot 9 .
The latch 7 is integral with the first end portion 3 and is bent radially inwards in such a way that it engages with the latching hook 8 .
In FIG. 3 , the spring band clip 1 according to FIG. 2 is shown in the released state so that, after releasing the locking device 6 , for example, the latch 7 has been deformed by the action of a release tool, such that the latch 7 has been moved over the latching hook 8 , so that the end sections 3 , 4 are moved away from one another in the circumferential direction. Due to the pretension of the clip band 2 , the spring band clip 1 has contracted and now has a reduced diameter compared to the state shown in FIG. 2 . Accordingly, the overlap region 5 has increased.
By the reception of the second end portion 4 in the slot 9 of the clip band 2 , both the latch 7 and the latching hook 8 are axially centered in the clip band 2 . This results in a very symmetrical force transmission. At the same time, simple production is possible.
The entire spring band clip 1 , including the clip band 2 , the end portions 3 , 4 and the locking device 6 are made as a single element, for example, a steel band. The locking device 6 is formed by simple stamping and bending of the latch 7 and the latching hook 8 .
Thus, this results in a spring band clip 1 , which enables holding in the expanded state, while the manufacturing cost is simultaneously kept low. This spring band clip 1 has a simple structure and a low mass and requires only a small space. It therefore does not require additional components, which ensures easy handling.
It is noted that the foregoing examples have been provided merely for the purpose of explanation and are in no way to be construed as limiting of the present invention. While the present invention has been described with reference to an exemplary embodiment, it is understood that the words which have been used herein are words of description and illustration, rather than words of limitation. Changes may be made, within the purview of the appended claims, as presently stated and as amended, without departing from the scope and spirit of the present invention in its aspects. Although the present invention has been described herein with reference to particular means, materials and embodiments, the present invention is not intended to be limited to the particulars disclosed herein; rather, the present invention extends to all functionally equivalent structures, methods and uses, such as are within the scope of the appended claims.
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Spring band clip, removal tool, and method of operating spring band clip. The spring band clip includes an annular curved clip band having a first end portion and a second end portion, which are arranged to form an overlapping region and which are spaced radially from the clip band. A locking device, at least partially integrated in the first end portion, is structured and arranged to lock the clip band in an expanded state.
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BACKGROUND OF THE INVENTION
The present invention relates to a quilting machine with adjustable-length cloth-holder cylinder.
Currently various types of quilting machines, used for the quilting of quilted blankets, eiderdowns, mattresses and the like, are available on the market. In a first type of quilting machine, the cloth to be quilted is stretched and fixed on a first carriage, which slides linearly on a second carriage.
The second carriage also slides in a direction at right angle relatively to that of the first carriage. The carriages are controlled so as to move below a fixed sewing head according to a trajectory imparted by a template or by another control system.
Another type of quilting machine operates exactly in reverse; in fact, it is the sewing head which moves along orthogonal axes with respect to a stationary carriage whereon the cloth to be quilted is fixed.
This known quilting machines have markedly excessive planar dimensions. Furthermore, the movement of the carriages, due to the considerable inertia masses involved, imposes operational limitations.
SUMMARY OF THE INVENTION
The technical aim of the present invention is therefore to provide a quilting machine which allows to obviate the disadvantages of known ones, in particular considerably reducing the dimensions and having a high flexibility in use in terms of the possibility of operating on products with different dimensions and thicknesses.
This aim is achieved by a quilting machine, characterized in that it comprises a cloth-holder cylinder supported rotatable about a horizontal axis and provided with means for fastening a cloth along a cylindrical path, a sewing head supported externally to said cloth and slideable parallel to the cylinder, means for the movement of said sewing head and of said cylinder being furthermore provided to impart a predetermined trajectory to the sewing line.
BRIEF DESCRIPTION OF THE DRAWINGS
Further characteristics of the invention will become apparent from the following description of an embodiment illustrated only by way of non-limitative example in the accompanying drawings, wherein:
FIG. 1 is a partially schematic elevation view of the machine;
FIG. 2 is an elevation view of the part related to the cloth-holder cylinder;
FIG. 3 is a view along the sectional plane III--III of FIG. 2;
FIG. 4 is a view along the sectional plane IV--IV of FIG. 2;
FIG. 5 is a view along the sectional plane V--V of FIG. 2;
FIG. 6 is a view along the sectional plane VI--VI of FIG. 1.
DESCRIPTION OF THE PREFERRED EMBODIMENT
With reference to the above described figures, the machine comprises a frame composed of three columns 1, 2 and 3 which rest on the ground and are mutually connected by an upper beam 4 and by an intermediate beam 5, both horizontal. Two superimposed openings 6, 7 are defined between the beams 4 and 5 and the columns 2 and 3.
The beams 4 and 5 are each composed of two members 8, 9 and respectively 10, 11 having counterposed C-shaped cross sections (FIGS. 2, 3, 4).
Between the columns 2 and 3, at the lower opening 7, there extends a horizontal beam 12 with square cross section with the faces inclined at 45° with respect to a vertical plane and provided, at the opposite ends, with flanges for fixing to the columns.
The portions of the columns 2 and 3, which delimit the lower opening 7 at the sides, widen towards the ground and two respective downwardly extending brackets 13, 14 are frontally rigidly associated therewith. The opposite ends of a tubular beam 15 with square cross section, parallel to the preceding beam 12, are welded to the brackets 13, 14.
Three angular elements 16, 17, 18 are rigidly associated with the column 2, on the face opposite the column 3 and below the members 10, 11. A frame 19, having the shape of an inverted triangle with the lower vertex underlying the beam 12, is fixed to the angular elements 16,17,18.
Brackets are arranged at the vertices of the frame 19 for the rotatable support of three rollers 20, 21, 22. The rollers 20, 21, 22 are tangentially in contact with the inner surface of a hoop 23 with square cross section (see FIG. 5) which embraces the beam 5. The hoop 23 is therefore capable of rolling on the rollers 20, 21, 22. To prevent the derailment of the hoop, respective pairs of rollers 24, 25, 26 which roll on the opposite sides of the hoop are provided on the supporting brackets of the rollers 20-22. Small angularly distributed L-shaped elements 27 are rigidly associated on the inward face of the hoop, that is to say on the face opposite to the one directed towards the column 2, and bear needles 28 directed radially outwards or appropriate clamps, and act as hooking elements for an edge of the cloth to be quilted. The other edge of the cloth is hooked to the same number of needles 29 fixed to small L-shaped elements 30 which protrude from a second hoop 31 coaxial to the hoop 23 and rotatably coupled thereto. However the hoop 31 is capable of being moved with respect to the hoop 23 depending on the width of the cloth to be quilted. For this purpose the hoop 31 is mounted rotatable on a carriage 32 composed of two triangular frames 33, 34, similar to the frame 19, and connected to one another by crossbars 35.
The frame 34 carries at the vertices three free rollers 36, 37, 38 tangent internally to the hoop 31, to each whereof is coupled a pair of anti-derailment rollers 39, 40, 41 according to a construction identical to the one related to said rollers 24-26.
From the crossbars 35 protrude two brackets, converging internally to the frame 32, and which rotatably support two respective wheels 42, 43 having planes of rotation perpendicular to one another. The wheels 42, 43 roll on the upper faces of the beam 12, which thus constitutes a sort of sliding rail for the carriage 32.
Above the carriage 32 and laterally with respect to the members 10, 11, bushes 44, 45 are mounted wherein slide two guiding bars 46, 47 fixed to the sides of said members parallel to the beam 12. The bars 46, 47 have the purpose of preventing oscillations of the carriage 32 the weight whereof rests in any case on the beam 12.
The hoop 31 moves with respect to the hoop 23 by means of a threaded rod 48 which has an end axially rigidly associated but rotatable with respect to the column 3 below the beam 5.
The rod 48 is engaged in a female thread 49 rigidly associated with the carriage 32 and is actuated by a reversible motor reducer 50 installed below the beam 5.
For the motorization of the hoops 23 and 31 a single motor is provided, consisting of a reversible motor reducer 51 mounted centrally on the beam 15 and provided with an output shaft 52 the opposite ends whereof are supported in plates 53 and 54 rigidly associated with the angular element 17 and with the frame 34. The shaft 52 is telescoping to allow the mutual spacing and approach of the hoops 23 and 31.
On the shaft 52, at the planes of rotation of the hoops 23 and 31, respective pinions 55, 56 are keyed, whereon with the aid of pairs of free spools 57, 58 and 59, 60, protrudingly supported by the plates 53 and 54, there mesh two chains 61, 62 closed in a loop about said hoops.
Conveniently, on the outer surface of the hoops a strip 63 (see FIG. 5) is provided, in material having such characteristics as to keep the chain guided and allow the links of the chain to penetrate therein and ensure an effective traction action.
As illustrated above, while two lateral edges of the cloth to be quilted are hooked to the needles 28, 29 of the hoops 23, 31, for the fixing of the terminal and initial edges two needle-holder bars 64, 65 are provided which extend between the hoops 23 and 31, and each whereof is telescoping.
The needle-holder bar 64, which is the one which fastens the terminal edge of the cloth, is constituted by a tubular profiled element 66 with square cross section wherein slides a rod 67, also with square cross section, so as to cause a prismatic rotary coupling.
Evenly spaced L-shaped elements 68 are rigidly associated with the tubular profiled element 66 and orientated tangentially with respect to the hoops, each provided with a pair of needles 69. A plurality of clamps 70 can be provided on the rod 76, each having an L-shaped element 68 provided with a pair of needles 69. The clamps 70 are removable and adjustable on the rod 67 to allow its sliding in the profiled element 66 during the approach of the hoops. The coupling of the bar 64 to the hoops 23 and 31 is conceived so as to allow the rotation of said bar by a certain angle and to move the bar along the periphery of the hoops as a function of the length of the cloths to be quilted.
For this purpose, with the hoop 23 there is rigidly associated a ring 71 (FIG. 5) which protrudes inwards and on which a clamp is fixable, composed of two jaws 72, 73 locked to one another by a bolt 74.
The jaw 73 is rigidly associated with a disk 75 from which there extends a tang 76 engaged rotatably in a bush 77 welded in a recess provided on the head of the profiled element 66.
With the jaw 73 there is rigidly associated a small plate 78 from which there protrudes a small arm 79 which bears a flap 80 acting as abutment for a screw 81 screwed, in an adjustable manner, in a small column 82 fixed to the profiled element 66. Between the small column 82 and the flap 80 there acts a traction spring 83 which keeps the screw 81 resting against the flap 80. In this position the needles 69 are perpendicular to the plane of tangency of the hoops. Naturally the coupling of the rod 64 to the hoop 31 is fully identical to the one just described. The hoops 23 and 31 and the needle-holder bars 64 and 65 constitute what in the present description is defined as the cloth-holder cylinder.
The bar 64 oscillates in order to hook and unhook the needles 69 from the edge of the cloth. This operation is performed in a very precise angular stop position of the cylinder. The control is actuated by means of an L-shaped lever 84, articulated to the member 11 and controlled by an actuator constituted by a fluidodynamic jack 85. When the cylinder reaches the intended stop position, by actuating the jack 85, the lever 84 acts on a small roller 86 arranged on the profiled element 66, determining the rotation of the bar 64 in contrast with the return action of the springs 83 and, consequently, the lowering of the needles into the periphery of the cylinder.
Differently from the bar 64, the bar 65 for fixing the initial edge of the cloth does not rotate and extends telescopingly between the hoops 23 and 31. The bar 65 comprises therefore a tubular element 87 fixed to the hoop 23 and provided with small L-shaped elements 88 which bear pairs of needles 89. In the element 87 there is slideable a rod 90 fixed to the hoop 31, whereon needle-bearing clamps 91 are locatable. On the needles 89 there is superimposable a U-shaped profiled element 92, the opposite ends whereof are rigidly associated with respective levers 93, 94. The profiled element 92 is kept, by a spring 95, lowered on the needles so as to lock the edge of the cloth and at the same time provide a protection of the needles 89. To control the actuation in opening and in closure of the profiled element 92, a small roller 96 is provided on the lever 93; furthermore, a lever 97 acts on the small roller 96, the lever 97 being articulated to an arm 98 of the frame 1 and actuated by a jack 99.
To internally support the cloth stretched on the cylinder, a plurality of cylindrical sectors 100, 101, 102, 103 are fixed to stationary parts of the machine by means of arms 104, 105, 106, 107. More precisely, the sector 100 is fixed to the member 10, while the sectors 101, 102, 103 are fixed on one side to the frame 19 and, on the opposite side, to brackets rigidly associated with the inner face of the column 3. In FIG. 2 said sectors are not illustrated for the sake of clarity.
A grid 109 is arranged along the portion of circle comprised between the sectors 100 and 103, the grid 109 being in the shape of a cylindrical sector composed of two arcs 110, 111 connected to one another by telescoping rods. The grid 109 is movable radially outwards to push from the inside against the cloth and unhook it from the needles on which it is retained.
For this purpose, two stems 113, 114 are articulated to the opposite ends of the grid 109, proximate to the upper ends of the arcs 110, 111, and are vertically guided in a block 115 rigidly associated with the member 11 and respectively in a block 116 supported by an L-shaped element 117 to the carriage 32.
Between the upper ends of the arcs 110, 111 and the coupling points 118, 119 of the frame 19 and of the carriage 32, substantially vertical fluidodynamic jacks 120, 121 are arranged. Two similar jacks 122, 123 are arranged horizontally between the lower ends of the arcs 110, 111 and the couplings 124, 125 of the frame 19 and of the carriage 32. In this manner, by simultaneously actuating the jacks 120-123, the grid 109 moves along a radial component. To neutralize any unbalancing effects of the jacks the stems 113, 114 have a rack-like structure for engaging spools 126, 127 mutually connected by a shaft 128.
For quilting the cloth stretched on the cylinder, a sewing head 129 is provided, linearly movable along a generatrix of the cylinder. The sewing head is supported by a slider 130 slideable between the members 8-11 and constituted by a pair of shoulders 131, 132 which have two horizontal portions 133, 134 superimposed, C-shaped and mutually connected by transverse stiffening ribs 135. On the shoulders 131, 132, pairs of rollers 136 are laterally mounted for the sliding of the slider on rails 137 fixed inside the members.
The upper portion 133 of the slider moves above the cloth stretched on the cylinder, while the lower portion 134 enters the hoop 23 and moves below the cloth. The sewing head 129 and the so-called "crochet" device 138 (FIG. 3), which cooperates with the sewing head for the execution of the stitches, are mounted at the ends of the portions 133, 134.
Parallel to the sliding direction of the slider, a chain 139 is fixed thereon, and a pinion 140 of a motor reducer 141 flanged on the column 2 meshes therewith. The actuation of the motor reducer 141 determines the movement of the slider 130 and therefore of the sewing head 129 with respect to the cloth.
The operation of the described apparatus is as follows.
The cloth to be quilted is initially applied to the cylinder by hooking the initial edge of the cloth on the needles 89 against which it is fixed by the bar 92. Then, by rotating the cylinder, the lateral edges of the cloth are hooked on the needles 28, 29. The final edge of the cloth is finally hooked to the needles 69 of the bar 64 and once the cloth is stretched and cut the quilting is executed.
By virtue of the linear motion of the sewing head by means of the actuation of the motor reducer 141 and of the rotation of the cylinder by means of the motor reducer 51 (which causes both hoops 23, 31 to rotate simultaneously), it is possible to perform sewings according to any trajectory. Advantageously the motor reducers 51 and 141 are controlled by a programmed processor.
Once the quilting is completed the cloth is removed by unhooking the perimetral flaps of the cloth first from the needles 69, by means of the rotation of the bar 6 as a consequence of the abutment of the lever 84 on the roller 86, then from the needles 28 and 29 and from the needles 89.
An advantage of the described machine resides in the possibility of its rapid adaptation to the dimensions of the cloths to be quilted. In fact, by activating the motor reducer 50, it is possible to move the carriage 32 on the guides 46 and vary the distance between the hoops 23 and 31, while by slackening the locking force of the jaws 72, 73 on the rings 71 it is possible to move the bar 64 with respect to the bar 65.
As can be seen, the invention substantially achieves the intended aim and objects. In particular the machine has an extended dimension in one direction and therefore has substantially reduced overall dimensions with respect to that of conventional machines with the cloth-holder carriage movable in two orthogonal directions.
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The quilting machine includes a cloth-holder cylinder supported rotatable about a horizontal axis and provided with means for fastening the cloth along a cylindrical path. Externally to the cloth, along a generatrix of the cylinder, there moves a sewing head the motion whereof is coordinated with that of the cylinder so that the sewing line follows a predetermined trajectory.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a data processor, and more specifically to a method of locating and controlling a memory device provided in the data processor.
2. Description of Related Art
A typical conventional data processor includes a central processing unit (CPU) for executing data processing. The CPU is coupled to an address bus used to supply an address to an external device and a data bus for transferring data between the CPU and the external device. In addition, the CPU is coupled to a control bus used for controlling the external device. One typical CPU is adapted to handle a memory space in such a manner that a plurality of consecutive memory areas are treated as a one block. In this CPU, a width of an internal data bus is larger than a width of an external data bus. Therefore, a plurality of external bus cycles can be generated in response to one internal bus cycle. This type of CPU can be exemplified by Intel's microprocessor i8088 and a CPU including a cache controller therein. As known, the cache controller has adopted a data exchange procedure in which a memory space is divided into a plurality of blocks, and data exchange or transfer between a cache memory and an external memory is collectively executed in units of blocks.
In addition, the data bus is coupled to a plurality of DRAMs (dynamic random access memory), which constitute external memories for the CPU. Each of the DRAMs is controlled by one corresponding DRAM controller coupled to the address bus. Each DRAM controller is controlled by a control logic which is coupled to the CPU through a control bus in order to interface an operating timing between the control bus and the external device such as the DRAMs and the DRAM controller. Typically, the control logic supplies a common memory read signal and a common memory write signal to all the DRAM controllers. The DRAM controllers are also controlled by a decoder coupled to the address bus so that one of the DRAM controllers is selectively activated in response to a chip select signal generated by the decoder on the basis of the result of decoding of an address on the address bus.
The DRAM is configured to be capable of executing a high speed page mode operation, in which if a row address does not, change, a data exchange can be executed by changing only a column address and activating a column address strobe again. In a normal access mode, a row address and a column address are applied to the DRAM by executing an address input by two times. Therefore, since the input of the row address is unnecessary, the data exchange can be correspondingly executed at a high speed.
On the other hand, the DRAM has one restriction in which once a row address strobe is activated, a precharge period in which the row address strobe is made inactive is required. If the precharge period is not satisfied, a content of the DRAM will be lost.
Now, assuming that the address bus is composed of 32 bits, and two 1M DRAMs are used, an address of 0000 0000 h to 000F FFFF h is assigned to a first DRAM, and an address of 0010 0000 h to 001F FFFF h is assigned to a second DRAM, in a memory map of the data processor. Here, the suffix "h" means a hexadecimal notation. In addition, the CPU can access to the external device with units of block each of which includes a plurality of units of processing, similarly to the type including the cache memory therein. Here, the unit of processing is called a "word". For example, one block includes four words.
Under the above mentioned conditions, an operation of the conventional data processor will be discussed. At a T1 clock of a first bus cycle, an address is supplied to the address bus, and decoded by the decoder. If the supplied address designates the first DRAM, the decoder outputs an active chip select signal to a first DRAM controller associated with the first DRAM. On the other hand, a memory access is outputted to the control bus and converted by the control logic into an active memory read signal or into an active memory write signal. Now, assume that the memory read signal has been activated.
In response to the active chip select signal and the active memory read signal, the first DRAM controller associated with the first DRAM is activated. As a result, at a falling of the T1 clock, the row address strobe supplied to the first DRAM is activated by the first DRAM controller and thereafter maintained in an active condition. Then, the first DRAM controller supplies an address signal to the first DRAM during a high level period of the T1 clock. At a rising of a T2 clock following the T1 clock, the column address strobe supplied to the first DRAM is activated, so that a content of the first DRAM is outputted to the data bus. At an end of a low level period of the T2 clock, the data exchange is completed, and a first TB clock following the T2 clock rises. The TB clock is used in the high speed page mode operation, and makes it possible to execute the data exchange with only one clock. At a rising of the first TB clock, the column address strobe supplied to the first DRAM is inactivated, and a next address is supplied to the first DRAM during a high level period of the TB clock. At a falling of the first TB clock, the column address strobe supplied to the first DRAM is activated, and the a second data exchange is executed during a low level period of the TB clock. Succeeding to the first TB clock, second and third clocks are generated so that the same memory reading operation (the data exchange) is executed three times. As a result, the data exchange is executed four times in total by the T1 and T2 clocks and the succeeding first to third TB clocks.
Following the first bus cycle, a second bus cycle starts, and a T1 clock of the second bus cycle rises at an end of the low level period of the third TB clock of the first bus cycle. At the T1 clock, a next address is supplied to the address bus so that a memory access will be started. However, at a falling of the T1 clock of the second bus cycle, the row column strobe supplied to the first DRAM is inactivated, and maintained in an inactive condition for a period corresponding to one clock period, since a period for the precharging is required to have one clock period. As a result, the row column strobe supplied to the first DRAM is activated at a falling of the T2 clock of the second bus cycle. Namely, the starting of the memory access in the second bus cycle is delayed from the starting of the memory access in the first bus cycle by a period of time corresponding to one clock. Because of this, a TW clock is inserted between the T2 clock and the first TB clock in the second bus cycle, so that the CPU is brought into a wait condition so as to adjust the timing. This adjustment is controlled by the control logic.
As seen from the above, when the same bank of the memory is continuously accessed by the CPU, the data exchange, which will be completed with five clocks in ordinary cases, requires six clocks. As a result, the processing capacity of the data processor will correspondingly decrease. If first and second accesses are made to different banks, respectively, a second access can be completed with five clocks. However, considering a processing situation of the CPU, an instruction reading operation is of course executed for consecutive memory banks, and data processed by the CPU is collectively stored in some region of the memory (localization of access region). Therefore, the possibility of access to the same bank is higher than the possibility of access to different banks. As a result, opportunity of the six clock access is much.
The above mentioned operation time was made on the basis of clocks. In fact, however, various operating timings of different DRAMs coupled to the CPU must be satisfied. For example, an access period of time from the activation of the column address strobe until the completion of the data exchange must be ensured. Therefore, if the processing capacity of the data processor is increased by increasing the frequency of the clock, the operation based on the T1 and T2 clocks can be adjusted by inserting the TW clock for waiting, but it is not possible to adjust the operation of the TB clock by inserting the TW clock. As a result, there occurs a situation in which the operating timing (for example, the access period of time starting from the activation of the column address strobe) cannot be satisfied. In this situation, the data processor cannot properly operate.
In addition, the DRAM has rapid access mode such as the high speed page mode which is higher than the ordinary access operation. However, ROMs (read only memory) and SRAMs (static random access memory) always require the same access time. In the case that these memories are coupled to the CPU, if the CPU is adapted to execute a first memory access by the T1 and T2 clocks and each of succeeding memory accesses by one TB clock as in the conventional example explained hereinbefore, it is requires that the memory access can be completed by only one clock. As a result, expensive ROMs or SRAMs are required.
Furthermore, if ROMs or SRAMs are used, these memory resources are often located at the outside of the cache coverage. In addition, it is necessary to generate various control signals so that the data exchange between the DRAM and the CPU is executed in the high speed access mode (T1, T2, TB, TB and TB clocks) and the data exchange between the ROM or SRAM and the CPU is executed in a normal access mode (four sets of T1 and T2 clocks). However, if the ROMs or SRAMs are located at the outside of the cache coverage, the performance of the data processor inevitably degrades. If the CPU operates in different modes, the control circuit becomes complicated.
SUMMARY OF THE INVENTION
Accordingly, it is an object of the present invention to provide a data processor which has overcome the above mentioned defect of the conventional one.
Another object of the present invention is to provide a data processor capable of continuously accessing the same region of an external device with the same period of time as that required when a different region is accessed.
Still another object of the present invention is to provide a data processor capable of accessing a low access speed external device apparently as quick as the data processor accesses a high access speed external device.
The above and other objects of the present invention are achieved in accordance with the present invention by a data processor comprising a CPU and a memory accessed by the CPU, the memory being divided into a plurality of memory banks in such a manner that a size of one block that can be accessed by the CPU is assigned to one memory bank, the CPU generating a control signal for locating the memory banks in an interlaced or interleaved manner, one of the memory bank including a plurality of memory sub-banks, and the CPU generating another control signal for sequentially executing a data exchange between the CPU and the memory sub-banks.
The above and other objects, features and advantages of the present invention will be apparent from the following description of preferred embodiments of the invention with reference to the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a block diagram of a first embodiment of the data processor in accordance with the present invention;
FIG. 2 shows a memory map realized in the data processor shown in FIG. 1;
FIG. 3 is a timing chart showing an operation of the data processor shown in FIG. 1, in which two banks of memory are provided and a number of block each of which includes four words are located in the interleaved manner;
FIG. 4 is a block diagram of a second embodiment of the data processor in accordance with the present invention;
FIG. 5 shows a memory map realized in the data processor shown in FIG. 4;
FIG. 6 is a timing chart showing an operation of the data processor shown in FIG. 4, in which four banks of memory are provided and each of the memory banks includes two sub-banks;
FIG. 7 is a block diagram of a third embodiment of the data processor in accordance with the present invention;
FIG. 8 is a truth table illustrating an operation of the selector shown in FIG. 7;
FIG. 9 shows a memory map realized in the data processor shown in FIG. 7;
FIG. 10 is a timing chart showing an operation of the data processor shown in FIG. 7, in which four banks of memory are provided and each of the memory banks includes four sub-banks;
FIG. 11 is a logic diagram of the address decoder shown in FIG. 1; and
FIG. 12 shows a memory map realized in a typical conventional data processor.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring to FIG. 1, there is shown a block diagram of a first embodiment of the data processor in accordance with the present invention.
The shown data processor includes a central processing unit (CPU) 1 for executing data processing. The CPU is coupled to an address bus 2 used to supply an address to an external device and a data bus 2 for transferring data between the CPU and the external device. In the shown embodiment, the address bus 2 has a width of 32 bits, and respective bits of the address bus are designated by A 0 , A 1 , . . . , A 31 , where the suffix added to the letter "A" shows a bit position. Here, the CPU has a width of an internal data bus which is larger than a width of an external data bus. Therefore, a plurality of external bus cycles can be generated in response to one internal bus cycle. As mentioned hereinbefore, this type of CPU can be exemplified by Intel's microprocessor i8088 and a CPU including a cache controller therein.
In addition, the data bus 3 is coupled to a plurality of DRAMs 8-1 DRAM0 and 8-2 DRAM1, which constitute external memories for the CPU. DRAM0 8-1 and DRAM1 8-2 are controlled by DRAM controllers (DRAMC) 7-1 and 7-2 coupled to the address bus 2. Each of the DRAM controller 7-1 and 7-2 is controlled by a control logic 5 which is coupled to the CPU through a control bus 4 in order to interface an operating timing between the control bus 4 and the external device such as the DRAMs and the DRAM controller. The control logic 5 supplies a common memory read signal MRD 9 and a common memory write signal MWR 10 to all the DRAM controllers 7-1 and 7-2 in parallel. The DRAM controllers are also controlled by an address decoder 6 coupled to the address bus 2. The address decoder 6 decodes a portion of an address on the address bus 2 and generates chip select signals MEM0CS and MEM1CS, which are supplied to a chip selection input CS of the DRAM controllers 7-1 and 7-2, respectively. Here, the chip select signals MEM0CS and MEM1CS are an active low signal in which the signal is active when it is of "0" and inactive when it is of "1". In this specification, an upper bar means an active low signal.
The control logic 5 receives a bus cycle request from the CPU 1 through the control bus 4, and activates the memory read signal MRD 9 if the memory read is requested, and the memory write signal MWR 10 if the memory write is requested. In addition, when the memory (the external device to the CPU) completes the data exchange, the control logic 5 notifies it to the CPU 1 through the control bus 4.
For example, the address decoder 6 is constituted of inverters 12-1 to 12-12, 11-input AND gate 13 and 2-input NAND gates 14-1 and 14-2, connected as shown in FIG. 11. Address inputs DA 0 to DA 10 are respectively supplied through the inverters 12-1 to 12-11 to the AND gate 13, whose output is connected to the NAND gates 14-1 and 14-2. A Bank input BNK is supplied through the inverter 12-12 to the NAND gate 14-1 and directly to the NAND gate 14-2. With this arrangement, if all of address inputs DA 0 to DA 10 are of "0" and the BNK input is also of "0", the NAND gate 14-1 activates the chip select signal MEM0CS. When all of address inputs DA 0 to DA 10 are of "0" and the BNK input is of "1", the NAND gate 14-2 activates the chip select signal MEM1CS.
The DRAM controllers 7-1 and 7-2 have the same construction, and therefore, inputs and outputs are shown only for the DRAM controller 7-1. When a chip select input CS is active and when either the memory read signal MRD 9 or the memory write signal MWR 10 is active, the DRAM controller operates to control the associated DRAM. The DRAM controller has address inputs RA 0 to RA 19 , and operates to supply the address inputs RA 10 to RA 19 (often called a "row address") to address outputs MA 0 to MA 9 , coupled to an address input port of the associated DRAM. At the same time, the DRAM controller activates the row address strobe RAS. At this time, if the memory write signal MWR is active, the DRAM controller activates a write enable signal WE. Thereafter, the DRAM controller operates to supply the address inputs RA 0 to RA 9 (often called a "column address") to the address outputs MA 0 to MA 9 and at the same time, activates the column address strobe CAS.
Each of the DRAMs 8-1 and 8-2 is configured to be capable of executing the high speed page mode operation as already explained hereinbefore.
The above mentioned arrangement and construction are fundamentally the same as those of the conventional data processor. According to the present invention, the BNK input of the address decoder 6 is connected to the address bit A 2 of the address bus 2, and the address inputs DA 0 to DA 10 of the address decoder 6 are connected to the address bits A 21 to A 31 . On the other hand, the address inputs RA 0 to RA 19 of each DRAM controller are connected to the address bits A 0 , A 1 , A 3 to A 20 . (For reference, in a typical conventional data processor, the BNK input of the address decoder 6 is connected to the address bit A 20 of the address bus 2, and the address inputs RA 0 to RA 19 of each DRAM controller are connected to the address bits A 0 to A 19 .)
Referring to FIG. 2, there is shown a memory map realized in accordance with the above mentioned connection between the address bus and the address decoder and the DRAM controllers. As shown in FIG. 2, address 00000000 h to 00000003 h , 00000008 h to 0000000B h , 00000010 h to 00000013 h , 00000018 h to 0000001B h , . . . are assigned to the DRAM0 7-1. On the other hand, address 00000004 h to 00000007 h , 0000000C h to 0000000F h , 00000014 h to 00000017 h , 0000001C h to 0000001F h , . . . are assigned to the DRAM1 7-2. Namely, the memory banks are located by units of 4 words in the interleaved manner, differently from the conventional data processor in which, for example, memory banks are continuously located as shown in FIG. 12.
Referring to FIG. 3, there is shown a timing chart illustrating the operation of the data processor shown in FIG. 1.
Assume that the address "0" is outputted to the address bus at a T1 clock in a first cycle. The address decoder 6 decodes the address "0" and activates the chip select signal MEM0CS. In response to this signal, the DRAM controller 7-1 activates the row address strobe RAS at a falling the T1 clock, so that access to the DRAM 8-1 starts. Thereafter, the row address strobe RAS is maintained in the active condition.
Then, the DRAM controller 7-1 supplies an address signal of MA 0 to MA 9 to the DRAM 8-1 during a high level period of the T1 clock. At a rising of a T2 clock following the T1 clock, the column address strobe CAS supplied to the DRAM 7-1 is activated, so that a data exchanged between the DRAM 7-1 and the CPU 1 is executed through the data bus 3. At an end of a low level period of the T2 clock, the data exchange is completed, and a first TB clock following the T2 clock rises. At a rising of the first TB clock, the column address strobe CAS supplied to the DRAM 8-1 is inactivated, and a next address of MA 0 to MA 9 is supplied to the DRAM 8-1 during a high level period of the TB clock. At a falling of the first TB clock, the column address strobe CAS supplied to the DRAM 8-1 is activated, and the a second data exchange is executed during a low level period of the TB clock. Following to the first TB clock, second and third clocks are generated so that the same memory reading operation (the data exchange) is executed three times. As a result, the data exchange is executed four times in total by the T1 and T2 clocks and the succeeding first to third TB clocks. Thus, data is read from or written to the addresses of 00000000 h to 00000003 h in the memory map shown in FIG. 2.
Now, assume that an address of "4" is outputted to the address bus 2 in a T1 clock of a second cycle succeeding to the first cycle. In this situation, the chip select signal MEM0CS is inactivated and the chip select signal MEM1CS is activated. As a result, the access to the DRAM1 8-2 is executed completely similar to the above mentioned access to the DRAM0 8-1. At this time, the DRAM controller 7-1 inactivates the row address strobe RAS, so that the precharging period of time can be ensured for the DRAM0 8-1. As a result, data is read from or written to the addresses of 00000004 h to 00000007 h in the memory map shown in FIG. 2.
As seen from the above, although the data is read from or written to apparently continuous addresses in the memory, the memory access is alternately executed to the DRAM0 8-1 and the DRAM1 8-2, so that the delay of the access time caused for the precharging will not occur.
The above mentioned embodiment is such that, in the memory space, memory blocks each composed of four words are located in the interleaved manner. The reason for this is that the CPU under consideration can access four words as one block. For example, if the CPU is adapted to access sixteen words as one block, memory blocks each composed of sixteen words are located in the interleaved manner. In this case, the BNK input of the address decoder 6 is connected to the address bit A 4 of the address bus 2, and the address inputs DA 0 to DA 10 of the address decoder 6 are connected to the address bits A 21 to A 31 . On the other hand, the address inputs RA 0 to RA 19 of each DRAM controller are connected to the address bits A 0 , A 1 , A 2 A 3 , A 5 to A 20 .
Referring to FIG. 4, there is shown a second embodiment. This second embodiment is adapted to adjust a mismatching of the operating timing with the TB clocks, which is the second problem of the prior art discussed hereinbefore.
In FIG. 4, elements similar to those shown in FIG. 1 are given the same Reference Numerals and explanation thereof will be omitted. In the second embodiment, four DRAMs 8-1 to 8-4 are provided, and each of these DRAM is similar to the DRAMs shown in FIG. 1.
The second embodiment includes inverters 15-1 to 15-4, two-input NAND gates 16-1 to 16-4, bidirectional buffers 17-1 to 17-4 having a latch function. When an input E is active, the buffer is open. On the other hand, if an input D is "1", data is supplied from the data bus 3 to the DRAM, and when the input D is "0", data is supplied from the DRAM to the data bus 3.
DRAM controllers 18-1 to 18-4 are associated to the DRAMs 8-1 to 8-4. These DRAM controllers 18-1 to 18-4 operate basically similar to a conventional DRAM controller and the DRAM controller shown in FIG. 1. However, the DRAM controllers 18-1 to 18-4 have a different high speed page mode, an operating timing of which will be explained hereinafter.
The BNK input of the address decoder 6 is connected to the address bit A 2 of the address bus 2, and the address inputs DA 0 to DA 9 of the address decoder 6 are connected to the address bits A 22 to A 31 . The address input DA 10 of the address decoder 6 is grounded. On the other hand, the address inputs RA 0 to RA 19 of each of the DRAM controllers 18-1 to 18-4 are connected to the address bits A 1 and A 3 to A 20 .
The E input of the buffer 17-1 is connected to receive an output of the NAND gate 16-1 receiving an output of the inverter 15-2 receiving the MEM0CS signal and an output of the inverter 15-1 receiving the address bit A 0 . The E input of the buffer 17-2 is connected to receive an output of the NAND gate 16-2 receiving the address bit A 0 and the output of the inverter 15-2. The E input of the buffer 17-3 is connected to receive an output of the NAND gate 16-3 receiving an output of the inverter 15-3 receiving the MEM1CS signal and an output of the inverter 15-4 receiving the address bit A 0 . The E input of the buffer 17-4 is connected to receive an output of the NAND gate 16-4 receiving the address bit A 0 and the output of the inverter 15-3. On the other hand, the D input of each of the buffers 17-1 to 17-4 are connected to receive the memory write signal 10.
Referring to FIG. 5, there is shown a memory map realized in the second embodiment. As shown in FIG. 5, addresses of 0000000 h , 00000002 h , 00000008 h , 0000000A h , . . . are assigned to the DRAM00 8-1. Addresses of 00000001 h , 00000003 h , 00000009 h , 0000000B h , . . . are assigned to the DRAM01 8-2. Addresses of 00000004 h , 00000006 h , 0000000C h , 0000000E h , . . . are assigned to the DRAM10 8-3. Addresses of 00000005 h , 00000007 h , 0000000D h , 0000000F h , . . . are assigned to the DRAM11 8-4.
Referring to FIG. 6, there is shown a timing chart illustrating the operation of the second embodiment of the data processor shown in FIG. 4.
The address of the address bus changes at a T1 clock in a first cycle. If the address decoder 6 activates the chip select signal MEM0CS. In response to this signal, the DRAM controllers 18-1 and 18-2 activate the row address strobe RAS, so that access to the DRAM00 8-1 and DRAM01 8-2 starts. Thereafter, at a rising of a T2 clock following the T1 clock, the column address strobe CAS of the DRAM controllers 18-1 and 18-2 is activated, so that a data exchange between the DRAM00 8-1 and the DRAM01 8-2 and the CPU 1 becomes possible. At this time, the E input of the buffer 17-1 is activated, a data exchange between the DRAM00 8-1 and the CPU 1 is executed. At a first TB clock, the address changes, with the result that the E input of the buffer 17-2 is activated, a data exchange between the DRAM01 8-2 and the CPU 1 is executed. On the other hand, at a rising of the first TB clock, the column address strobe CAS is inactivated. At a rising of a second TB clock, the column address strobe CAS is activated, again. Thus, the DRAM10 and the DRAM11 sequentially execute the data exchange, similarly to the DRAM00 and the DRAM01.
After an end of the third TB clock, and at a T1 clock of a second cycle, the address changes, the chip select signal MEM0CS is inactivated and the chip select signal MEM1CS is activated. Therefore, the second embodiment can ensure the precharging time, similarly to the first embodiment.
In the second embodiment, the transition timing of the column address strobe CAS from the active condition to the inactive condition and vice versa is expanded to one clock, while the transition timing is a half clock in the first embodiment. Therefore, the controlling timing of the DRAMs is less severe, minimizing the requirements of the DRAM controllers.
Referring to FIG. 7, there is shown a third embodiment. In FIG. 7, elements similar to those shown in FIGS. 1 and 4 are given the same Reference Numerals and explanation thereof will be omitted. In the third embodiment, the memory includes eight banks.
The third embodiment includes selectors 22-1 and 22-2. An operation of each selector is illustrated in the truth table shown in FIG. 8.
When a G input of each selector is inactive, Y 0 , Y 1 , Y 2 and Y 3 outputs are inactive ("1"). When the G input is active, if A and B inputs are "0, 0", Y 0 is active, and if A and B inputs are "0, 1", Y 1 is active. If A and B inputs are "1, 0", Y 2 is active, and if A and B inputs are "1, 1", Y 3 is active.
DRAM controllers 19-1 to 19-8 will be explained hereinafter when an operating timing is explained. These DRAM controllers 19-1 to 19-8 are associated to eight DRAMs 20-1 to 20-8 (DRAM00 to DRAM03 and DRAM01 to DRAM13). Buffers 21-1 to 21-8 have the same function as the buffer 17 shown in FIG. 4.
The BNK input of the address decoder 6 is connected to the address bit A 2 of the address bus 2, and the address inputs DA 0 to DA 8 of the address decoder 6 are connected to the address bits A 23 to A 31 . The address inputs DA 9 and DA 10 of the address decoder 6 is grounded. On the other hand, the address inputs of each DRAM controller are connected to the address bits A 3 to A 20 . In addition, the A and B inputs of each selector are connected to the address bits A 0 and A 1 . The G input of the selector 18-1 is connected to receive the MEM0CS signal, and the G input of the selector 18-2 is connected to receive the MOM1CS signal.
Referring to FIG. 9, there is shown a memory map realized in the third embodiment. As shown in FIG. 9, addresses of 00000000 h , 00000008 h , . . . are assigned to the DRAM00. Addresses of 00000001 h , 00000009 h , . . . are assigned to the DRAM01. Addresses of 00000002 h , 0000000A h , . . . are assigned to the DRAM02. Addresses of 00000003 h , 0000000B h , . . . are assigned to the DRAM03. Addresses of 00000004 h , 0000000C h , . . . are assigned to the DRAM10. Addresses of 00000005 h , 0000000D h , . . . are assigned to the DRAM11. Addresses of 00000006 h , 0000000E h , . . . are assigned to the DRAM12. Addresses of 00000007 h , 0000000F h , . . . are assigned to the DRAM13.
Referring to FIG. 10, there is shown a timing chart illustrating the operation of the third embodiment of the data processor shown in FIG. 7.
If the address on the address bus changes at a T1 clock in a first cycle, the address decoder 6 activates the chip select signal MEM0CS. In response to this signal, the DRAM controllers 19-1 to 19-4 activate the row address strobe RAS, so that access to the DRAM00 to DRAM03 starts. In response to the address outputted in synchronism to the T1 clock, the Y 0 output of the selector 22-1 is activated, so that a data exchange between the DRAM00 and the CPU 1 is executed at an end of the T2 clock, namely at a rising of a first TB clock. Similarly, at the first TB clock, the Y 1 output of the selector 22-1 is activated, so that a data exchange between the DRAM01 and the CPU 1 is executed. The Y 2 output of the selector 22-1 is activated at the second TB clock, so that a data exchange between the DRAM10 and the CPU 1 is executed. The Y 3 output of the selector 22-1 is activated at the third TB clock, so that a data exchange between the DRAM11 and the CPU 1 is executed.
In the third embodiment, since the four DRAMs (DRAM00 to DRAM03 or DRAM10 to DRAM13) are driven at the same one-time timing, the DRAM high speed page mode access is not used. Therefore, the DRAMs and the DRAM controllers can be replaced by memories such as ROMs or SRAMs which have a constant access speed.
The invention has thus been shown and described with reference to the specific embodiments. However, it should be noted that the present invention is in no way limited to the details of the illustrated structures but changes and modifications may be made within the scope of the appended claims.
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A data processor which includes a central processing unit (CPU) coupled to an address bus for supplying an address to an external memory and a data bus for supplying data to the external memory and receiving data from the external memory, and a control logic for controlling data exchange between the CPU and the external memory with a predetermined unit amount of data processing of the central processing unit. The external memory includes first and second DRAMs and the CPU executes the data exchange with units of four words. Each DRAMs has a memory area divided into a number of sub-areas each have four continuous addresses, so that the sub-areas of the first DRAM and the sub-area of the second DRAM are alternately assigned in continuous addresses in one memory space formed of the first and second DRAMs. When an continuous addresses are supplied, a controller controls so that the first and second DRAMs are alternately accessed.
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Related Application
The present application is a continuation-in-part application of application Ser. No. 399,156, filed Sept. 20th, 1973, to Joseph M. Zaidan and now U.S. Pat. No. 3,861,816.
BACKGROUND OF THE INVENTION
The present invention relates to a coupling for scaffolding.
Previously proposed couplings used for assembling scaffolding tubes include bolts and nuts which serve to connect the tubes to the coupling. The erection of scaffolding with couplings of this type represents a difficult and lengthy process because for each tube connection bolts must be screwed into the nuts. Furthermore, due to the weather exposure which occurs on building sites, bolts are liable to rust and deteriorate thereby increasing the difficulty of assembling the scaffolding.
SUMMARY OF THE INVENTION
An object of the present invention is to at least reduce these disadvantages by providing a robust coupling which eliminates the need for nuts and bolts.
According to the present invention there is provided a coupling for use in the construction of a scaffolding assembly. The coupling includes a central link, two pairs of arms projecting from the link, each arm having an aperture therein and each pair of arms being intended to embrace a respective scaffolding member, and a pair of wedges adapted to project through the apertures in a respective pair of arms to bear upon and retain in position an embraced scaffolding member, in which each wedge is provided with stop members to resist withdrawal from the apertures.
The stop members extend outwardly from opposite sides of each wedge to a width greater than a dimension of one aperture of each pair of arms. The wedges are made from an elongated trapezoidal blank strip, which is bent to have a U-shaped cross-section, and the stop members are formed by bending outwardly opposite corners of the thinner end of each wedge. The other apertures of each arm pair have lateral recesses through which the stop members pass. Consequently, the wedges can be slid freely into the apertures of each pair of arms before the scaffolding members are embraced, but the wedges cannot be separated from the fully assembled coupling and scaffolding members because the stop members when inserted block one of the apertures of each arm pair.
To satisfy certain standards which prohibit direct contact of the wedges with scaffolding tubes, two flat base plates are provided, each of which is inserted beneath a wedge in the apertures of each pair of arms.
According to a preferred embodiment, each base plate includes a rectangular plate provided at the ends of its longitudinal sides with four projections which serve to prevent the withdrawal of the base plate from the apertures. The apertures of the arms are shaped and dimensioned such that while the base plates can be introduced thereinto, for example, by inclining them relative to their normal position of use, they cannot be withdrawn from the apertures once in place.
One embodiment of a coupling arrangement according to the invention will now be described with reference to the attached drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a general perspective view showing the assembly of two scaffolding tubes by the use of a coupling arrangement according to the invention.
FIG. 2 is a plan view of a blank from which a coupling member of the coupling arrangement shown in FIG. 1 is made.
FIGS. 3 to 5 show a wedge member of the coupling arrangement during three successive stages of its manufacture.
FIG. 6 shows a base plate for separating the wedge member and a scaffolding tube.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring to FIG. 1, the coupling arrangement includes a coupling member 1 and two wedges 2 and 3. As shown in FIG. 2, the coupling member 1 is made from a cross-shaped metal blank having four arms 4 to 7, connected to a central portion 8, and each perforated with apertures 9 to 12 respectively. Apertures 9 and 10 of the two contiguous arms 4 and 5 have a rectilinear edge and a rounded edge whose concavity is turned towards the central portion 8. The height of apertures 9 and 10 is greater than the width. Apertures 11 and 12 formed on the two other arms have the same dimensions as apertures 9 and 10, but each has on its base two lateral slots 13.
The blank of FIG. 2 is brought into the shape of the coupling member shown in FIG. 1 by bending arms 4 and 6 on one side of central portion 8 until they are substantially perpendicular to the latter, and by bending in the same way arms 5 and 7 on the other side of the central portion.
Each of the wedges is made from an elongated metal blank strip 14 of trapezoidal shape as shown in FIG. 3. A plurality of notches 15 are formed on the flat surface of blank 14, with the notches being parallel to the base of the blank. With the aid of a press the blank is shaped into a member 16, as shown in FIG. 4, having a U-shaped cross-section whose outer surface is shaped in complementary manner to that of the rounded edge of apertures 9 to 12. After introducing the thinnest end of each member 16 through two apertures of a respective pair of arms, the corners thereof are twisted towards the outside in such a way as to form two horns 17 and 18 constituting stop members. The deformation can be such that the distance between the ends of the horns is greater than the width of apertures 9 and 10 but less than the width of apertures 11 and 12 level with recesses 13.
Between the wedges and the tubes to be assembled are inserted base plates 19, one of which is shown in detail in FIG. 6. The base plate includes a rectangular rigid plate provided at the ends of its longitudinal sides with four projections 20. The length of the portion of the base plate between the projections is at least equal to the distance separating the outer faces of one pair of arms and the width of the portion of the base plate is slightly less than the width of apertures 9 and 10. Moreover, the width of the base plate level with projections 20 is greater than the width of apertures 9 and 10, but less than the height of the latter. As a result of this dimensioning, the plates can be introduced into the apertures by inclining them in the direction of the height of the apertures. On turning the base plates again in the direction of the width of the apertures, they then cannot separated from the coupling member.
Each wedge can have a plurality of protruberances along its facing side. These protruberances, which could either be in addition or alternative to the notches, are arranged in the same manner as the notches.
The coupling according to the invention is assembled in the works in such a way that a ready-to-use product is obtained. The assembly method is described below.
First of all the base plates are fitted by placing them in front of apertures 9 and 10 and respectively orientating them in the direction of the height of these apertures. Projections 20 can freely traverse the apertures in view of the relative dimensions of these and the base plates. The base plates are then pivoted by 90°.
The wedges are then fitted into the apertures. To do this, the wedges 16 as shown in FIG. 4 are used. The tapered ends of the wedges are introduced into apertures 9 and 10, and then into apertures 11 and 12. The horns 17 and 18 of the wings at the tapered ends are then bent towards the outside. The wedges and base plates are then definitively integral with the coupling member 1. However, they can freely slide through the slotted apertures 11 and 12 because the width of the base plates level with the projections, as well as the width between the horns 17 and 18 of the wedges are less than the width of the apertures 11 and 12 level with recesses 13.
To assemble two scaffolding tubes 21 and 22, the base plates and wedges are withdrawn from apertures 11 and 12 until the projections 20 and horns 17 and 18 strike against the inner surface of arms 4 or 5. Then tubes 21 and 22 are inserted between arms 4 and 6 and 5 and 7 respectively, and the wedges and base plates are pushed through the slotted apertures 11 and 12 and then are jammed by means of hammer blows. Tubes 21 and 22 are then locked against the central portion 8. The notches 15 formed on the outer surface of the wedges prevent a sliding or untimely withdrawal of the wedges under the action of vibrations. According to the invention, the effectiveness of these notches is increased if, during manufacture, arms 4 and 5 are inclined slightly outwardly in such a way that the notches are hooked on the outer edges of apertures 9 and 10.
To free tubes 21 and 22 a hammer blow is applied to the narrow edges of the wedges. However, the wedges and base plates are not separated completely from the coupling member 1. This represents one of the advantages of the invention because in this way there is no danger that the wedges accidentally fall or get lost.
It should be noted that in the operating position wedges 2 and 3 bring about an elastic deformation of the tubes which contributes towards the prevention of accidental unlocking of the wedges. Thus the latter continue to exert their locking action even if they are slightly displaced towards the aperture as a result of vibrations or shocks.
The described coupling therefore offers complete safety and reliability, but is still extremely simple to assemble and disassemble.
Each of the arms 4 to 7 has a width L (see FIG. 2) which is relatively large, for example 8 cm, so that each offers an immediate support point to the respective scaffolding tubes 21 and 22. The connecting points of the tubes thus become semifixation points. Consequently the buckling lengths of the tubes are reduced and the tubes are able to withstand greater loads. If the width L of the arms is too small, for example less than 5 cm, the connection between the scaffolding tubes becomes an articulated-type connection.
Tests have shown that a coupling member 1, which is cut from a 6 mm thick metal sheet and has arms 4 to 7 about 7 cm wide, is able to resist a force of 1,800 applied for example by means of a hydraulic jack at one end of one of the tubes. This performance is very satisfactory in view of the normal load which has to be borne by a coupling which is of the order of 750 kg.
The coupling according to the invention also has the advantage of being of very simple in construction because it requires neither screws, bolts nor hinges and because it can be mass produced at competitive prices.
It is noted that the above description and the accompanying drawings are provided merely to present an exemplary embodiment of the present invention and that additional modifications of such embodiments are possible within the scope of this invention without deviating from the spirit thereof.
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A coupling for connecting two scaffolding members. A central link is provided with two pairs of arms, each projecting from the link. Each arm is provided with an aperture. Each pair of arms are adapted to embrace a respective scaffolding member. A respective wedge is adapted to project through the apertures in a respective pair of arms so as to bear upon and retain in position an embraced scaffolding member. Each wedge is provided with a pair of stop members which serve to resist withdrawal of the wedge from the apertures.
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CROSS REFERENCE TO RELATED APPLICATIONS
This application claims priority to PCT international patent application number PCT/EP2006/065775, filed Aug. 29, 2006 and German utility model 20 2005 013 691.3, filed Aug. 30, 2005.
FIELD OF THE INVENTION
The present invention relates to a connection device for the plug-type connection of at least one media conduit (pipeline or hose pipe for gases or liquids).
BACKGROUND OF THE INVENTION
Such a connection device is described both in WO 2004/029497 A1 and in WO 2005/028939 A1. In this known embodiment, the insert part is in the form of a sleeve and is inserted into an enlarged portion of the receiving opening of the base part so as to be circumferentially sealing at least with respect to the ingress of dirt or such contaminants. The insert part in the inserted state lies completely within the base part so as to terminate flush on the mouth side. Furthermore, the insert part comprises a first, relatively harder dimensionally stable plastic material, a dirt seal being integrally formed cohesively from a second, relatively softer and elastic plastic material in the free, mouth-side end region of the spring arms. The insert part is therefore in the form of an integral multicomponent molding made from plastic. The spring arms are formed by longitudinal slots of the sleeve-shaped insert part, the longitudinal slots likewise being filled with the injected material of the dirt seal. In the known connection device, it has been shown in practical use that it is sometimes very difficult to detach the conduit by removing the insert part from the base part.
SUMMARY OF THE INVENTION
The present invention is based on the object of improving a connection device of the type mentioned in such a way that the detachment process is simplified whilst maintaining secure locking of the inserted media conduit.
Accordingly the invention provides that the latching shoulders of the spring arms are decoupled from the sealing region of the dirt seal with respect to their radial detachment movement via a deformation zone in such a way that the radial detachment movement of the latching shoulders as a result of the deformation of the deformation zone, with respect to a detaching force to be applied for the detachment movement, takes place substantially uninfluenced by the dirt seal, which rests radially on the media conduit. This achieves an advantageously low detachment force for the detachment movement.
A first embodiment provides that each spring arm has, as a deformation zone in a region lying between an inner cone and a free spring arm end, a weakening zone with reduced flexural stiffness in such a way that, when the free spring arm end is radially supported on the conduit (preferably indirectly via a dirt seal provided in this region), the latching shoulder is capable of moving radially inward into its detachment position under elastic bending deformation of the weakening zone. For this purpose, a lower radial detachment force is advantageously sufficient because the weakening zone according to the invention makes it possible to achieve a situation in which the free end region, which is preferably supported on the conduit circumference via the dirt seal, of each spring arm does not counteract the radial detachment movement, or only counteracts it to a lesser extent. This means that the latching shoulders of the spring arms with respect to their radial detachment movement are in practice decoupled from the free end region (preferably from the region of the dirt seal). The latching shoulders can therefore move radially with a low radial detachment force, without or with only unsubstantial movement of the spring arms in the end-side region. As a result, overall the detachability is markedly improved. By virtue of the fact that the weakening zone is in each case preferably arranged axially between the latching shoulder and the free spring arm end, in practice, a flexible joint is formed between these regions.
In a second embodiment of the invention, the spring arms with their free ends are decoupled from the mouth-side end of the sleeve-shaped insert part via axial interspaces, the deformation zone being formed by regions of an elastic plastic material which are arranged in the region of the free spring arm ends and in the interspaces and are integral with the dirt seal, in such a way that during the radial detachment movement of the latching shoulders, the free spring arm ends are correspondingly concomitantly moved radially under the elastic material deformation of the plastic material of the deformation zone. This may also result proportionally in a bending deformation in the region of the free ends of the spring arms.
In the preferred embodiments, by virtue of the fact that the spring arms are decoupled from the mouth side of the insert part, the latter can be formed at its mouth-side end with a ring section, which is continuous in the circumferential direction, with a planar, front end ring face. This ensures improved support of the dirt seal in particular in the axial direction.
Despite the improved detachability as a result of the invention, at the same time there is also a high level of protection against undesired detachment. For this purpose, preferred configurations will be explained in the text which follows.
BRIEF DESCRIPTION OF THE DRAWINGS
In the text which follows, the invention will be explained in more detail with reference to preferred exemplary embodiments illustrated in the figures of the drawing, in which:
FIG. 1 shows an axial section of a first embodiment of a connection device according to the invention in a first section plane (plane I-I shown in FIG. 2 ), by way of example in an embodiment as an elbow connector with plugged media conduit,
FIG. 2 shows an axial section in a second plane (II-II according to FIG. 1 ) which is arranged at right angles with respect to the plane according to FIG. 1 ,
FIG. 3 shows an enlarged illustration of the region III in FIG. 2 with the media conduit only illustrated by dashed lines,
FIG. 4 shows a perspective view of an insert part according to the invention,
FIG. 5 shows an enlarged plan view of the insert part in the arrow direction V according to FIG. 4 ,
FIG. 6 shows a partially sectioned side view in the arrow direction VI according to FIG. 5 ,
FIG. 7 shows an enlarged partial section S-S according to FIG. 6 ,
FIG. 8 shows a section D-D according to FIG. 5 ,
FIG. 9 shows an enlarged illustration of the region C in FIG. 8 ,
FIG. 10 shows an enlarged illustration of the region W in FIG. 8 ,
FIG. 11 shows a cross section in two axially offset planes corresponding to the profile of the section line F-F in FIG. 8 ,
FIG. 12 shows an enlarged illustration of the region U in FIG. 11 ,
FIG. 13 shows an enlarged partial section R-R according to FIG. 6 ,
FIG. 14 shows a section A-A according to FIG. 5 ,
FIG. 15 shows a section B-B according to FIG. 5 ,
FIG. 16 shows an enlarged section L-L according to FIG. 14 ,
FIG. 17 shows an enlarged section K-K according to FIG. 14 ,
FIG. 18 shows a section G-G according to FIG. 5 ,
FIG. 19 shows an enlarged illustration of the region J in FIG. 18 ,
FIG. 20 shows an enlarged partial section M-M according to FIG. 19 ,
FIG. 21 shows an enlarged illustration of the region F′ in FIG. 8 ,
FIG. 22 shows a section in the plane I-I according to FIGS. 8 and 21 ,
FIG. 23 shows an enlarged illustration of the region Y in FIG. 15 ,
FIG. 24 shows a second embodiment of the insert part as an alternative to FIG. 4 ,
FIG. 25 shows an enlarged plan view of the insert part in the arrow direction XXV according to FIG. 24 (similar to FIG. 5 ),
FIG. 26 shows a side view XXVI according to FIG. 25 (similar to FIG. 6 ),
FIG. 27 shows a section D-D according to FIG. 25 (similar to FIG. 8 ),
FIG. 28 shows an enlargement of the region N in FIG. 27 ,
FIG. 29 shows a cross section corresponding to the section line F-F in FIG. 27 (similar to FIG. 11 ),
FIG. 30 shows an enlargement of the region U in FIG. 29 (similar to FIG. 12 ),
FIG. 31 shows a section G-G in FIG. 25 (similar to FIG. 18 ),
FIG. 32 shows an enlargement of the region J in FIG. 31 (similar to FIG. 19 ),
FIG. 33 shows an axial section of a second embodiment of a connection device according to the invention, by way of example in the form of a through-connector for two media conduits (not illustrated),
FIG. 34 shows a section in the plane A-A according to FIG. 33 ,
FIG. 35 shows an enlargement of the region. B in FIG. 34 ,
FIG. 36 shows a side view of the insert part in the embodiment according to FIGS. 33 to 35 ,
FIG. 37 shows a plan view of the mouth side in the arrow direction C according to FIG. 36 ,
FIG. 38 shows an axial section in the plane D-D according to FIG. 37 ,
FIG. 39 shows an axial section in the plane G-G according to FIG. 37 (rotated through 90° in the plane of the drawing),
FIG. 40 shows a side view (sectioned in regions), of the insert part in the arrow direction E according to FIG. 37 ,
FIG. 41 shows a section in the radial plane I-I according to FIG. 40 ,
FIG. 42 shows a detail enlargement of the region b in FIG. 39 , and
FIG. 43 shows a very enlarged view of the region N in FIG. 38 .
DETAILED DESCRIPTION
In the various figures of the drawing, identical parts have always been provided with the same reference symbols, with the result that each description of a part, which may appear only once with reference to a specific drawing figure, also applies analogously with respect to the other figures of the drawing in which the part with the corresponding reference numeral can likewise be seen.
A connection device 1 according to the invention comprises, according to FIGS. 1 to 3 and FIGS. 33 to 35 , a housing part 2 with, at least, one receiving opening 4 , which is open at one end, for axially inserting an end of a media conduit 6 in the form of a pipeline or hose pipe and a clamping ring 8 which is arranged in the housing part 2 or within the receiving opening 4 , for locking the axially, i.e. in the direction of a plug axis 10 , inserted conduit 6 . In this case, the connection device 1 makes it possible for the conduit 6 , which in particular is made from plastic, to be fitted simply and quickly by means of simply being inserted into the housing part 2 without any other fitting steps. The clamping ring 8 rests in an enlarged portion of the receiving opening 4 in such a way that it surrounds the receiving opening 4 and therefore the inserted conduit 6 . At a point on its circumference, the clamping ring 8 has an axially and radially continuous slot, i.e. an interruption in its circumferential profile, as a result of which it can be radially elastically enlarged and/or constricted. In its inner circumferential region, the clamping ring 8 (see in this regard in particular the larger illustrations in FIGS. 3 and 35 ) has (at least) one radially inwardly protruding, circumferential tooth edge 12 . In addition, the clamping ring 8 has (at least) one outer cone 14 , which interacts with an inner cone 16 of the housing part 2 for the purpose of locking the conduit 6 in such a way that when the conduit 6 is pulled in the detachment direction (arrow direction 18 in FIGS. 1 to 3 ), i.e. in the event of a movement counter to the insertion direction (arrow 20 in FIGS. 1 to 3 ), the clamping ring 8 is first carried along by the force-fitting bearing state of its tooth edge 12 until its outer cone 14 comes to rest in the inner cone 16 of the housing part 2 . If the conduit is pulled further, a radially inwardly directed force is produced via the cones 14 , 16 , by means of which force the clamping ring 8 is elastically constricted, with the result that the tooth edge 12 interacts in a force-fitting and/or interlocking manner with the substantially smooth, cylindrical conduit outer circumference and, as a result, the conduit 6 is locked so as to prevent it from being withdrawn. In this case, an advantageous configuration, which is not illustrated, however, can provide that the inner cone 16 of the housing part 2 comprises two axially adjacent inner cone sections with different cone angles. A first inner cone section, which is positioned at a distance from the insertion side (mouth side of the housing receiving opening), is designed to have a first, relatively flat cone angle, and a second inner cone section, which is adjoining in the direction toward the insertion or mouth side, has a second, steeper cone angle. In this case, the outer cone 14 of the clamping ring 8 also comprises two axially adjacent outer cone sections with corresponding cone angles so as to match the inner cone sections. As a result of this configuration, shortening of the axial return path for locking purposes is achieved. Details in this regard are included in the earlier application DE 20 2005 009 575.3, to which full reference is therefore made.
In order to seal off the conduit 6 in a pressure-tight manner, a sealing ring 24 (pressure seal) is arranged within the housing part 2 in the region between the clamping ring 8 and a bore step 22 . In addition, a supporting sleeve 26 , which is coaxial with respect to the plug axis 10 , is preferably arranged within the housing part 2 for engaging in the inserted conduit 6 . The supporting sleeve 26 therefore supports the inserted or plugged-on, conduit 6 on the one hand against the radial force applied via the clamping ring 8 and on the other hand also against the bearing force of the sealing ring 24 from the inside. As a result, the connection device 1 according to the invention is in principle also suitable for relatively flexible hose pipes.
For, on the one hand, the producibility and fitability of the connection device 1 and, on the other hand, the detachability of the conduit 6 , the housing part 2 is formed in two parts; it comprises a base part 28 and an insert part 32 . The insert part 32 has the inner cone 16 and is connected to the base part 28 via an interlocking latching connection 30 (snap-action interlocking connection with an active face/undercut angle of greater than/equal to 90°). The insert part 32 has, on the mouth side, a dirt seal 34 with a sealing region A for bearing circumferentially on the inserted conduit 6 . The insert part 32 is described in more detail further below with reference to the separate illustrations in FIGS. 4 to 23 and 36 to 43 .
The above-described supporting sleeve 26 , in the case of parts which have not been shaped by machining technology, is expediently designed to be integral with the base part 28 , in particular as a molding made from plastic (see FIGS. 1 and 2 ). According to FIGS. 33 to 35 , the supporting sleeve 26 can also be in the form of a separate insert part 26 a . As a result, the insert part 26 a with the supporting sleeve 26 on the one hand and the base part 28 on the other hand can comprise different materials.
Preferably, the insert part 32 with the dirt seal 34 is formed as an integral multicomponent molding comprising in particular at least two different plastic materials, to be precise the insert part 32 comprises a first, relatively harder and dimensionally stable plastic material, while the dirt seal 34 is integrally formed in one piece directly cohesively from a second, relatively softer and elastic plastic material. Preferably, this material is a thermoplastic elastomer (TPE). In this case, the dirt seal 34 has, on its side pointing radially inward, the seal region A for bearing circumferentially on the conduit 6 .
The insert part 32 is formed together with the dirt seal 34 overall substantially in the form of a sleeve and inserted into an enlarged portion of the receiving opening 4 of the base part 28 . In order to seal off the gap between the base part 28 and the insert part 32 against the ingress of dirt and the same contaminants, the insert part 32 has a seal 37 on its outer circumference. In the preferred embodiment illustrated, this seal 37 comprises a relatively soft elastic material and, for this purpose, is integrally formed in particular in one piece and cohesively in a similar manner to the dirt seal 34 . The seal 37 therefore preferably comprises a TPE (thermoplastic elastomer). In this case, it is particularly advantageous if the insert part 32 in the inserted state lies completely within the base part 28 so as to terminate flush on the mouth side. This results in an advantageously compact design of the connection device 1 , which has a planar end face, which is closed via the dirt seal 34 toward the conduit 6 , on the mouth side.
For the detachability of the conduit 6 , provision is made for the sleeve-shaped insert part 32 (see in this regard in particular the separate, enlarged illustrations in FIGS. 4 to 23 and 36 to 43 ) to have at least two radially elastic, diametrically opposite spring arms 40 , which are formed by longitudinal slots 38 . Each spring arm 40 engages with a radially outwardly protruding, tab-like latching shoulder 42 in an interlocking manner, i.e. with an undercut ≧90°, in a corresponding latching opening 44 of the base part 28 in a detachable manner. The latching openings 44 are in this case in the form of radial through-openings, with the result that the latching shoulders 42 can be reached from the outside with a suitable tool and moved radially inward for detachment purposes, as a result of which the conduit 6 together with the clamping ring 8 and the insert part 32 can be removed (arrow direction 18 in FIGS. 1 to 3 ).
In the preferred configuration described, it is furthermore advantageous if the longitudinal slots 38 of the insert part 32 are completely filled with the material of the dirt seal 34 (see in this regard in particular the section A-A in the region of the longitudinal slots 38 in FIG. 14 and the cross section in FIG. 11 ). This configuration means that optimum dirt sealing is ensured since actual gaps are avoided even in the region of the longitudinal slots 38 . Nevertheless, the elasticity of the sealing material filling the longitudinal slots 38 (in particular a TPE) allows for the necessary radial movement of the spring arms 40 .
Alternatively, the dirt seals 34 and 37 can be embodied by separate elastomeric inserts (for example O rings). In this case, however, it is advantageous to fill the longitudinal slots 38 as described with an elastic material (TPE).
In the embodiments according to FIGS. 1 to 32 (see in this regard, for example, FIGS. 4 , 6 , 8 , 14 , 15 and 18 ), the longitudinal slots 38 forming the spring arms 40 run from the region of the inner cone 16 continuously as far as the opposite, mouth-side end of the sleeve-shaped insert part 32 . As a result, the spring arms 40 extend starting from a circumferentially closed ring section 46 , which has the inner cone 16 , of the insert part 32 with its free ends 48 as far as the mouth side, where the free ends 48 are connected to the dirt seal 34 .
According to the invention, it is now provided in all embodiments that the latching shoulders 42 of the spring arms 40 are decoupled from the region of the dirt seal 34 with respect to their radial detachment movement via a deformation zone 49 in such a way that the radial detachment movement of the latching shoulders 42 takes place substantially uninfluenced by the dirt seal 34 , which is supported radially on the media conduit 6 , with the principal deformation of the deformation zone 49 as regards a detachment force to be applied for the detachment movement. As a result, the detachment force is largely independent of an opposing force brought about by the dirt seal 34 , with the result that, overall, an advantageously low detachment force is sufficient for actuating the latching shoulders 42 .
In order to improve or facilitate the detachability of the latching connection 34 , the embodiments according to FIGS. 1 to 32 provide that each spring arm 40 has, as a deformation zone 49 , a weakening zone 50 with reduced flexural strength in such a way that, when the free spring arm end 48 is radially supported via the dirt seal 34 on the conduit 6 , the latching shoulder 42 is capable of moving radially inward into its detachment position under elastic bending deformation of the weakening zone 50 . In this regard, reference is made to the illustrations in FIGS. 2 and 3 . If, for detachment purposes by means of a suitable tool (not illustrated) through the latching openings 44 , in each case a radial detachment force F L is applied to the latching shoulders 42 , as a result the spring arms 40 are moved (pivoted) overall elastically radially inward. Since, however, the free ends 48 of the spring arms 40 are supported, indirectly via the dirt seal 34 , on the circumference of the media conduit 6 , given a continued radial movement of the latching shoulders 42 in each case a bending deformation in the region of the weakening zone 50 occurs after a specific radial compression of the dirt seal 34 , with the result that the weakening zone 50 acts as a flexible joint. As a result, in practice the free spring arm ends 48 are “decoupled” from the detachment force, i.e. the free ends 48 at most cause only a slight force which counteracts the detachment force F L , as a result of which the detachment force F L is overall advantageously low.
In a preferred embodiment, the weakening zone 50 of each spring arm 40 is arranged in the region lying axially between the latching shoulder 42 and the dirt seal 34 . In this case, advantageously the weakening zone 50 of each spring arm 40 can be formed by a cross-section reduction, to be precise by a cross-section reduction of at least 25% to at most approximately 75%, preferably of from 50% to 75% to from approximately 50% to 25%, of the original spring arm cross section which is provided in the adjoining regions of the spring arm 40 . In this case, the cross-section reduction can be formed by an outer radial cutout and/or by an inner radial enlargement of the inner cross section.
In the preferred exemplary embodiment illustrated according to FIGS. 1 to 32 , on the one hand each spring arm 40 has, in the weakening zone 50 on its radially outwardly pointing side, a radial cutout 52 , which preferably runs in the manner of a groove in the circumferential direction. On the other hand, the insert part 32 has, in the region of the spring arms 40 on its inner side pointing radially inward toward the conduit 6 and in the region of the deformation zones 49 , an enlarged inner diameter. In this case, it is provided that the inner diameter adjoining the smallest diameter of the inner cone 16 is enlarged in the direction of the deformation zones 49 via cone sections 54 running at an angle. In this regard, particular reference is made to FIG. 3 and also to FIGS. 8 and 15 . Accordingly, an edge 56 with an inner diameter which is greater than the outer diameter of the media conduit 6 ( FIG. 3 ) is formed between the inner cone 16 and the cone sections 54 in the region of each spring arm 40 . As a result of the inner contour described of the spring arms 40 , a radial movement play which is sufficient for the detachment movement is provided. During the detachment movement, in each case the edge 56 of each spring arm 40 cannot come to bear on the conduit 6 beyond a certain radial excursion, as a result of which a further radial movement of each spring arm 40 then only still takes place in the region between the edge 56 and the free end 48 or the deformation zone 49 (as a result of the free ends 48 of the spring arms 40 being supported on the conduit 6 via the dirt seal 34 ).
An advantageous configuration of the invention will now be explained with reference to FIGS. 2 , 3 and 5 and FIGS. 34 , 35 and 37 . Accordingly, the latching shoulder 42 of each spring arm 40 has a latching edge face 58 with an outer radius of curvature R a , which is at least approximately equal to the inner radius R i of the base part 28 . According to FIGS. 5 and 37 , in the unstressed rest position of the spring arms 40 the latching edge faces 58 protrude radially outward beyond the inner circumference, which substantially corresponds to the outer circumference of the insert part 32 , of the base part 28 , in order that the latching edge faces 58 can engage in the latching openings 44 . In this case, the radii mid-points of the radii of curvature R a of the latching edge faces 58 are radially offset with respect to the radii mid-point of the radius R i . As a result of the detachment movement of the latching shoulders 42 radially inward, the mid-points of the radii R a then move toward the mid-point of the radius R i , with the result that the latching edge faces 58 then also precisely correspond to the inner curvature of the base part 28 . As a result, an improvement of the release of the latching during detachment is achieved by virtue of the latching shoulder 42 of each spring arm 40 with the latching edge face 58 coming completely free from the region of the latching opening 44 given the smallest possible radial excursion. If, in contrast to this, the radius of curvature R a were to be greater by the offset of the mid-points of the radii R a and R i according to FIGS. 5 and 37 , each latching shoulder 42 would have to be moved further radially inward in order that the lateral end regions, which point in the circumferential direction, of the latching edge face 58 also come free from the latching opening 44 . The detachment is likewise facilitated by this advantageous configuration.
In a preferred configuration, it is also provided according to FIG. 23 that holding edges are formed within the insert part 32 adjacent to the inner cone 16 as an axial end stop opposing a movement of the clamping ring 8 directed in the withdrawal direction of the conduit 6 , to be precise first holding edges 60 are formed in the region of the spring arms 40 and second holding edges 62 are formed in the regions lying between the spring arms 40 and in each case between the slots 38 . As a result of the holding edges 60 , 62 , high withdrawal forces are made possible, which ensures a high level of protection against undesired detachment of the conduit 6 . In this case it is provided according to FIG. 23 that the first holding edges 60 are offset with respect to the second holding edges 62 by an axial offset X in the direction of the inner cone 16 in such a way that the clamping ring 8 (not illustrated here), when subjected to a force F Z acting in the withdrawal direction of the conduit 6 , first comes to bear only on the first holding edges 60 , as a result of which the spring arms 40 are subjected to a radially outwardly acting holding force component F H . In this case, the axial offset X is designed to be small, however, so that, after a deformation in the elastic region, the clamping ring 8 additionally comes to bear against the second holding edges 62 , which further improves the protection against detachment. When the clamping ring 8 is bearing against the first holding edges 60 , forces are therefore resolved, the radial component F H ensuring that the holding force of the elastic spring arms 40 is increased. As a result, very high withdrawal forces are achieved.
In particular in connection with the above-described configuration; it is furthermore advantageous if the latching shoulder 42 of each spring arm 40 has, in the region of its latching edge face 58 , a stop element 64 in such a way that, in a state in which the conduit 6 is subjected to the force F Z in the withdrawal direction, the latching shoulder 42 , in a position in which it engages in a defined manner in the latching opening 44 of the base part 28 , is supported against a further radially outwardly directed movement, which in particular results from the above-described holding force component F H . For this purpose, the stop element 64 is supported on the inner circumference of the base part 28 in the region adjoining the latching opening 44 (see in this regard FIGS. 2 and 3 ). As illustrated, the stop element 64 can be in the form of a shoulder on the latching edge face 58 (see in this regard, for example, FIGS. 6 , 8 and 10 ). The stop element 64 therefore delimits the spring excursion radially outward whilst loading the connection device 1 . This avoids a situation in which, in particular as a result of the radial holding force component F H , the spring arms 40 could be pushed too far radially outward. As a result of such an excessive deformation of the insert part 32 , the latter could possibly jam during the detachment process and/or the clamping ring 8 could be ripped out despite the axial stop at the holding edges 60 , 62 . These problems are advantageously avoided by the stop elements 64 ; the detachability is improved whilst ensuring high withdrawal forces.
As can furthermore best be seen in the enlarged illustrations in FIGS. 3 and 35 , each latching shoulder 42 advantageously has, on its side protruding radially outward, when viewed in the axial direction, a rounded-off flank face 66 . As a result of the fact that the contour of the outer region is rounded off in this way, undesired compressions in the region between the latching edge face 58 and the base region, which adjoins the ring section, of the spring arms 40 are avoided which can result owing to the bending during unlocking of the spring arms 40 . In addition, the frictional forces when withdrawing the unlocked insert part 32 are reduced.
Finally, in an advantageous configuration the dirt seal 34 is chambered axially on both sides on the free mouth side at least in subregions of its circumference. On the mouth side, this is achieved by injection-molded web sections 68 comprising the relatively hard first plastic material (see, for example, FIGS. 3 , 8 and 21 ). These web sections 68 also act as a supporting ring for the dirt seal 34 , with the result that good dimensional stability is achieved.
FIGS. 24 to 32 illustrate a second embodiment of the insert part 32 , in which in particular the region of the dirt seal 34 is modified with respect to the first embodiment shown in FIGS. 1 to 23 . In order to ensure a good sealing effect toward the inserted media conduit 6 for providing safe dirt sealing as a result of relatively high radial compression, but at the same time to keep the plugging force to be applied for inserting the conduit 6 and also the radial detachment force F L (cf. FIG. 3 ) low, this embodiment according to FIGS. 29 to 32 provides that tangential or secant-like recesses 70 are formed in the region of the longitudinal slots 38 between the relatively soft plastic material and the relatively hard plastic material radially outside and axially beneath the region of the dirt seal 34 (see also FIGS. 39 and 42 ). This can be achieved in terms of molding technology by corresponding cross-slides. In this case, according to FIGS. 31 and 32 the dirt seal 34 is supported in the region of the recesses 70 axially in the insertion direction 20 (cf. FIGS. 1 to 3 ) via webs 72 comprising the elastic material. Furthermore, according to FIGS. 27 and 28 the region of the largest inner cross section of the weakening zone 50 according to the invention of each spring arm 40 directly adjoins a radial face 74 , which points in the insertion direction 20 , of the dirt seal 34 . As a result of these described measures, a certain flexibility is achieved in the region of the dirt seal 34 given a good radial sealing effect in such a way that the radial compression of the dirt seal 34 has at most very little influence on the detachment force F L and on the plugging force.
The embodiment according to FIGS. 33 to 43 differs from the embodiments according to FIGS. 1 to 32 by a particular configuration of the deformation zone 49 according to the invention. In this case, the spring arms 40 are designed to be axially shortened in such a way that they, with their free ends 48 , are decoupled from the mouth-side end of the sleeve-shaped insert part 32 via axial interspaces 80 . In this case, the deformation zone 49 is formed by regions of an elastic plastic material, which are arranged in the region of the free spring arm ends 48 and in the interspaces 80 and are integral with the dirt seal 34 in such a way that, during the radial detachment movement of the latching shoulders 42 , the free spring arm ends 48 are concomitantly moved radially under elastic material deformation of the elastic plastic material. In this regard, particular reference is made to the enlarged illustration in FIG. 43 . Preferably, the free end 48 of each spring arm 40 is formed by an axial radially inner web section 82 , whose radially measured thickness is reduced in comparison with the spring arm 40 . In this case, the elastic plastic material forming the deformation zone 49 engages over the web sections 82 radially and axially in the direction toward the latching shoulders 42 . As a result of this advantageous configuration, a ring section 84 , which is continuous in the circumferential direction and comprises the first, dimensionally stable plastic material, can be formed at the mouth-side end of the insert part 32 . This ring section 84 has a planar, front end ring face 86 . This configuration results in improved axial support and covering (chambering) of the dirt seal 34 for the purpose of protection, for example, against a water jet (see in this regard in particular FIGS. 35 , 38 and 43 ).
In a further advantageous configuration, preferably two mutually diametrically opposite, radially outwardly protruding shoulders 88 are arranged at the mouth-side end of the sleeve-shaped insert part 32 (see, for example, FIGS. 37 and 40 ). These shoulders 88 engage in corresponding cutouts of the base part 28 in such a way that they are used firstly for radially positioning the insert part 32 in the base part 28 and secondly as an end stop for the axial insertion limitation (see in particular FIG. 33 ).
The invention is not restricted to the exemplary embodiments described and illustrated, but also includes all embodiments with a similar effect within the context of the invention.
As a person skilled in the art will appreciate, the above description is meant as an illustration of implementation of the principles of this invention. This description is not intended to limit the scope or application of this invention in that the invention is susceptible to modification, variation, and change, without departing from the spirit of this invention, as defined in the following claims.
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A connector device having a housing part and a clamping ring arranged in the receiving hole and cooperating with an inner cone of the housing part to lock a plugged-in media conduit. An inner insertion piece is removably connected to a base piece and provided with the inner cone. The insertion piece has at least two radially elastic spring arms to enable removal of the conduit. Radially outward-protruding catching extensions of the spring arms engage catching holes for detaching purposes. A contamination seal is disposed in the region of free ends of the spring arms to circumferentially rest upon the media conduit. The catching extensions are disconnected from the sealing area via a deformation zone so that the radial detaching movement of the catching extensions is performed without being influenced by the contamination seal because the deformation zone is deformed.
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CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims the benefit of U.S. Provisional Application No. 62/110,263, filed Jan. 30, 2015; U.S. Provisional Application No. 62/112,032, filed Feb. 4, 2015; and U.S. Provisional Application No. 62/113,092, filed Feb. 6, 2015, which are incorporated by reference herein.
TECHNICAL FIELD
[0002] This description relates generally to data analysis, and more particularly to denoising and data fusion of biophysiological rate features.
BACKGROUND
[0003] Data analysis generally encompasses processes of collecting, cleaning, processing, transforming, and modeling data with the goal, for example, of accurately describing the data, discovering useful information or features among the data, suggesting conclusions, or supporting decision-making. Data analysis typically includes systematically applying statistical or logical techniques to describe, condense, illustrate and evaluate data. Various analytic techniques facilitate distinguishing the signal or phenomenon of interest from unrelated noise and uncertainties inherent in observed data.
[0004] Sensor data fusion techniques typically provide higher-level information from data observed at multiple sensors, for example, employing spatio-temporal data integration, exploiting redundant and complementary information, as well as available context. Exploratory data analysis often applies quantitative data methods for outlier detection attempt to identify and eliminate inaccurate data. In addition, descriptive statistics, such as the statistical mean, median, variation or standard deviation may be generated to help interpret the data. Further, data visualization may also be used to examine the data in graphical format, providing insight regarding the information embedded the data.
[0005] In general, statistical hypothesis testing, or confirmatory data analysis, employs statistical inference to determine if a result is significant based on a confidence interval or threshold probability. Model selection techniques may be employed to determine the most appropriate model from multiple hypotheses. Decision theory and optimization techniques, including chi-square testing, may further be employed to select the best of multiple descriptive models. Statistical inference methods include, but are not limited to, the Akaike information criterion (AIC), the Bayesian information criterion (BIC), the focused information criterion (FIC) the deviance information criterion (DIC), and the Hannan-Quinn information criterion (HQC).
[0006] A photoplethysmogram (PPG) is an optically obtained plethysmogram, or volumetric measurement of an organ. The pulse oximeter, a type of PPG sensor, illuminates the skin with one or more colors of light and measures changes in light absorption at each wavelength. The PPG sensor illuminates the skin, for example, using an optical emitter, such as a light-emitting diode (LED), and measures either the amount of light transmitted through a relatively thin body segment, such as a finger or earlobe, or the amount of light reflected from the skin, for example, using a photodetector, such as a photodiode. PPG sensors have been used to monitor respiration and heart rates, blood oxygen saturation, hypovolemia, and other circulatory conditions.
[0007] Conventional PPGs typically monitor the perfusion of blood to the dermis and subcutaneous tissue of the skin, which may be used to detect, for example, the change in volume corresponding to the pressure pulses of consecutive cardiac cycles of the heart. If the PPG is attached without compressing the skin, a secondary pressure peak may also be seen from the venous plexus. A microcontroller typically processes and calculates the peaks in the waveform signal to count heart beats per minute (bpm).
[0008] However, signal noise from sources unrelated to desired features, including, for example, motion artifacts and electrical signal contamination, have proven to be a limiting factor affecting the accuracy of PPG sensor readings. While the signal noise from sources unrelated to desired features may be avoided in a clinical environment, this signal noise may have an undesirable effect on PPG sensor readings taken in free living conditions, for example, during exercise. As a result, some existing data analysis methodologies may have drawbacks when used with PPG sensor readings taken in free living conditions.
SUMMARY
[0009] According to one embodiment, a device includes a memory that stores machine instructions and a processor coupled to the memory that executes the machine instructions to receive a plurality of feature data points and extract a feature from a feature data point of the plurality of feature data points that satisfy a predetermined range. The processor further executes the machine instructions to perform a plurality of hypothesis tests to determine whether the feature corresponds to each of a plurality of predetermined hypothesis distributions comprising a first hypothesis distribution. If the feature corresponds to the first hypothesis distribution, the processor further executes the machine instructions to qualify the feature as a qualified estimate of an actual feature.
[0010] According to another embodiment, a method includes receiving a plurality of feature data points and extracting a feature from a feature data point of the plurality of feature data points that satisfy a predetermined range. The method further includes performing a plurality of hypothesis tests to determine whether or not the feature corresponds to each of a plurality of predetermined hypothesis distributions comprising a first hypothesis distribution. The method also includes qualifying the feature as a qualified estimate of an actual feature if the feature corresponds to the first hypothesis distribution.
[0011] According to yet another embodiment, a computer program product includes a non-transitory, computer-readable storage medium encoded with instructions adapted to be executed by a processor to implement receiving a plurality of feature data points and extracting a feature from a feature data point of the plurality of feature data points that satisfy a predetermined range. The instructions are further adapted to implement performing a plurality of hypothesis tests to determine whether or not the feature corresponds to each of a plurality of predetermined hypothesis distributions comprising a first hypothesis distribution. The instructions are also adapted to implement qualifying the feature as a qualified estimate of an actual feature if the feature corresponds to the first hypothesis distribution.
[0012] The details of one or more embodiments of the present disclosure are set forth in the accompanying drawings and the description below. Other features, objects, and advantages of the present disclosure will be apparent from the description and drawings, and from the claims.
DESCRIPTION OF THE DRAWINGS
[0013] FIG. 1 illustrates a block diagram depicting an exemplary biophysiological periodic data analyzer in accordance with an embodiment.
[0014] FIG. 2 illustrates a flowchart of an exemplary method of multiple-model adaptive estimation used to analyze biophysiological periodic data in accordance with an embodiment.
[0015] FIG. 3 illustrates a graph depicting exemplary statistical hypotheses for use in performing statistical inference regarding feature data in accordance with an embodiment.
[0016] FIG. 4A illustrates a flowchart of an exemplary method of analyzing biophysiological periodic data in accordance with an embodiment.
[0017] FIG. 4B illustrates another flowchart of an exemplary method of analyzing biophysiological periodic data in accordance with an embodiment.
[0018] FIG. 4C illustrates another flowchart of an exemplary method of analyzing biophysiological periodic data in accordance with an embodiment.
[0019] FIG. 5 illustrates a schematic view depicting a computing system that may be employed in a biophysiological periodic data analyzer in accordance with an embodiment.
DETAILED DESCRIPTION
[0020] FIG. 1 illustrates a block diagram of an exemplary biophysiological periodic data analyzer, according to one embodiment. An biophysiological periodic data analyzer 10 includes a feature receiver 12 , a rate calculator 14 , an outlier eliminator 16 , a recent rate calculator 18 , a rate filter 20 , a rate change computer 22 , a biosemantic binary qualifier 24 , a feature modifier 26 , and a filter generator 28 . The feature receiver 12 is configured to receive multiple simultaneous data points from various sensors monitoring biophysiological features of a subject, including, but not limited to, a heart rate (HR), a respiration rate, a fluid solution concentration, and a bodily movement. The subject may include, but not limited to, a person, an animal, and a living organism.
[0021] The data points include a data fusion from multiple sources coming from different features on the same underlying sensors, or different sensors. For example, the data points include feature data regarding a subject's heart rate and respiration rate observed over time using photoplethysmogram (PPG) sensors, such as pulse oximeters. In one embodiment, the PPG sensor and the biophysiological periodic data analyzer may be embedded in a wearable device that is fastened to a subject, for example, the subject's head, foot, finger, and wrist.
[0022] The feature receiver 12 sorts the monitored feature data points and places the data points in order, for example, feature-by-feature. The feature receiver 12 outputs each ordered data point along with a synchronous time output. The rate calculator 14 uses the most recent data point and a corresponding time output to calculate the current feature rate based on a series of recent data points.
[0023] The outlier eliminator 16 determines whether the current feature rate falls within an acceptable range based on a set of predetermined biological limits regarding the feature, for example, minimum and maximum rate limits. A current feature rate that falls outside the acceptable range are not used in further calculations. The recent rate calculator 18 uses a series of current feature rates within the acceptable range during a desired window of time to calculate an updated recent feature rate.
[0024] The outlier eliminator 16 imposes constraints on the hypotheses based on biophysiological limits. For example, a minimum limit (‘minHR’) and a maximum limit (‘maxHR’) may be based on the realistic expected range of human heart rates. Similarly, minimum and maximum relative limits (‘+/−deltaHR’) centered around the recently observed heart rate value (uRecent) may be based on physiological limitations regarding the rate of change of the heart rate over the sampling time.
[0025] The rate filter 20 performs statistical calculations on qualified feature data from the biosemantic binary qualifier 24 , which is further explained below. FIG. 2 illustrates a flowchart of an exemplary method of multiple-model adaptive estimation (MMAE) used to analyze biophysiological periodic data in accordance with an embodiment. MMAE 30 may be implemented by the rate filter 20 to analyze qualified feature data. In an embodiment, the rate filter 20 includes multiple Kalman filters, each based on a different model. For example, a first Kalman filter 32 is based on a first model, a second Kalman filter 34 is based on a second model, a third Kalman filter 36 is based on a third model, and a fourth Kalman filter 38 is based on a fourth model. Optionally, the statistical calculations may implement weightings attached to the data from each of the input streams, for example, indicating a preference for information from one stream over that of another stream. The rate change computer 22 continuously computes the current rates of change regarding the filtered and unfiltered rates.
[0026] The fusion at the hypothesis level follows an approach equivalent to that used in the generic multiple-model adaptive estimation framework, as described in the context of Kalman filters by P. D. Hanlon and P. S. Maybeck in “Multiple-Model Adaptive Estimation Using a Residual Correlation Kalman Filter Bank,” IEEE Transactions on Aerospace and Electronic Systems, Vol. AES-36, No. 2, April 2000, pp. 393-406, the entirety of which is incorporated herein by reference. The Kalman filter estimation involves an estimate and an uncertainty of the state of the system. For instance, in an embodiment, an unscented Kalman filter associated with alternate hypotheses of system behavior is used, which explicitly fits a distribution from deterministic sampling of the input, as described in Simon J. Julier & Jeffrey K. Uhlmann, “A new extension of the Kalman filter to nonlinear systems”, Int. Symp. Aerospace/Defense Sensing, Simul. and Controls, vol. 3, p. 182, 1997, the entirety of which is incorporated herein by reference.
[0027] The biosemantic binary qualifier 24 determines qualified data, or qualifies data, based on a binary selection criterion for each input feature, based on compatibility with learned probabilistic models (many possible methods for model development). The binary selection approach handles input data, even when there is a large fraction of anomalies, or uncertainty, in the feature data. The biosemantic binary qualifier 24 includes, for example, a maximum likelihood decision engine. The biosemantic binary qualifier 24 produces qualified data as output.
[0028] In an embodiment, the biosemantic binary qualifier 24 uses the recent rate along with the filtered and unfiltered rates of change to perform a hypothesis testing method 40 . Multiple hypothetical models are considered for each observed data point, and the decision to accept the point is made based on a decision rule for each hypothesis. The model hypotheses incorporate biophysical limits on both on rates of change and the hard limits on the values of the inputs, grounded in biophysiological constraints. Each hypothesis transforms the input feature differently, depending on the nature of the hypothesis.
[0029] FIG. 3 illustrates a graph depicting exemplary statistical hypotheses for use in performing statistical inference regarding feature data in accordance with an embodiment. A graph 50 illustrates various exemplary test hypotheses. Based on the window statistics with respect to a particular time window, such as the mean and standard deviation of the windowed rates, multiple hypothetical probability models are trained, or developed. In an embodiment, the test hypotheses consist of discrete expected probability distributions, for example, including a recent distribution 52 , a trial distribution 54 , and an artifact distribution 56 .
[0030] Referring to FIG. 3 , the decision question is presented: “Should a new beat 58 be accepted as a legitimate heart beat?” Two exemplary hypotheses have been developed with respect to the heart rate (HR), as follows: A first hypothesis, the recent distribution 52 , presumes the measured input feature is consistent with the recently observed heart rate. A second hypothesis, the trial distribution 54 , presumes the measured input feature has been corrupted and is consistent with one-half the recently observed heart rate. The second hypothesis is related to a specific sort of signal corruption that gives an accurate estimate of one-half the heart rate, which is grossly inaccurate for the true rate. A third hypothesis, artifact distribution 56 , presumes the measured input feature has been corrupted and is consistent with an artifact that is unrelated to the true heart rate. In other embodiments, additional hypotheses may be included, for example, based on characteristics of the input data stream.
[0031] The biosemantic binary qualifier 24 tests each of the hypotheses on the basis of a probabilistic test. For instance, in the case of the first hypothesis type described, both the recent distribution 52 and the candidate point 58 are available. Therefore, the computation of the posteriori likelihood of the point being derived from the distribution is used to represent the posteriori likelihood of the associated hypothesis.
[0032] Each hypothesis is considered independently—on the basis of its own test against a null hypothesis. For instance, a hypothesis is based on exceeding a threshold in a log-likelihood ratio test, or in exceeding a threshold with respect to the affinity to the distribution associated with the hypothesis. Following this, all hypotheses which overcome the null hypothesis are ranked based on an a priori ranking among hypotheses and the highest ranked hypothesis is selected. This has the advantage that diverse hypothesis types may be considered—some with an explicit probability model for which likelihood may be computed, but others using logical triggers for which no explicit probability model exists.
[0033] Thus, these statistics are combined among the different data sources, and then applied across each of the hypotheses. Alternatively, separate statistics may be calculated associated with each data type and these may be selectively attached to different hypotheses.
[0034] In an alternate embodiment in which all of the hypotheses have explicit probabilities, the hypothesis selection may then proceed by computing the relative likelihood of each hypothesis computed and selecting the most likely hypothesis is selected as being correct. This triggers certain logic, as described below, to either accept or to reject the candidate point.
[0035] For example, the feature data point may be accepted as measured, based on a relatively high correlation to the hypothesis associated with the recent distribution 52 . Otherwise, the feature modifier 26 may modify the feature data point before it is accepted, for example, based on a relatively high correlation to the hypothesis associated with the trial distribution 54 . On the other hand, the feature data point may be dropped from the output stream, based on a relatively high correlation to the hypothesis associated with the artifact distribution 56 .
[0036] The filter generator 28 updates the rate filter 20 and provides feedback to the biosemantic binary qualifier 24 to develop the model hypotheses. The model hypotheses are stochastic processes, which calculate the increases in uncertainty associated with the time-sensitivity of information gathered. If no recent feature data has been explained, the uncertainty grows. In an embodiment, the statistics calculation implements, for example, a Langevin correction. This modifies the probability model to account for the time value of data by growing the model variance with the time gap period. In an embodiment, the Langevin model, which is based on physical models of Brownian motion, grows the model variance linearly with time.
[0037] FIGS. 4A through 4C illustrate flowcharts of an exemplary method of analyzing biophysiological periodic data in accordance with an embodiment. Examples of biophysiological periodic data that may be analyzed using the present method described in this disclosure include, for example, a heart rate (HR), a respiration rate, a fluid solution concentration, and a bodily movement. The present method processes one or more streams of feature data regarding a biophysiological feature over time and outputs a single stream of qualified data.
[0038] Referring to FIG. 4A , input data tracks 62 , 64 , and 65 are fed in order, feature-by-feature at 60 . In one embodiment, the features may include, for example, the interbeat interval of a heart, a respiration rate, a step rate, and any other periodic signal from a biophysiological sensor. A feature data stream is separated into a sensed event at 68 , and a corresponding time at 70 . The output time at 70 is presented to a process that continues at FIG. 4B , and the output rate, and/or output trial rate at 72 is presented to processes that continue at FIGS. 4B and 4C . At 72 , a current rate (thisRate) associated with the sensed event and a trial rate (trialRate) associated with a statistical hypothesis are each calculated based on the event at 68 .
[0039] A set of fixed, or absolute, biophysiological limits regarding the features are received at 74 , and a determination is made at 76 , regarding whether the rate and/or trial rate at 72 fall within an acceptable range defined by the biophysiological limits. If the rate and/or trial rate at 72 are found to be within the acceptable range at 76 , the process continues at 80 of FIG. 4B . Otherwise, the rate and trial rate at 72 that fall outside the acceptable range are discarded at 78 . The biophysiological limits are forwarded to the process at 80 of FIG. 4B .
[0040] Referring to FIG. 4B , if the rate and/or trial rate at 72 are found to be within the acceptable range at 76 , the recent rate based on statistics over a trailing window of time is updated at 80 , based on the rate at 72 and the time at 70 in FIG. 4A . Data points that fall outside the acceptable range at 76 of FIG. 4A are trimmed from the input to the recent rate. At 82 , the current rate of change of the rate of block 72 is computed, resulting in a delta rate (deltaRate) at 84 . The recent rate calculated over a fixed window of time is stored in a buffer, at 86 .
[0041] In addition to the absolute limits applied at 76 , the present method also detects conditions in which limits on the allowable rate of change have been exceeded. A dynamic limit computed by the statistics of the recent time window, such as a confidence interval. For example, a ninety-percent confidence interval, a ninety-two-percent confident interval, or a ninety-five-percent confidence interval is applied based on a probabilistic model fit with respect to the previous window.
[0042] Statistical feedback data from FIG. 4C is used to modify the recent rate filter (recentRateFilt), which is calculated over a time window and stored in a buffer 88 as illustrated in FIG. 4B . For example, the recent rate filter includes multiple Kalman filters, as described above. The data fusion among the different streams entering at the top of the block diagram of FIG. 4A is managed in the calculation of statistics in the recent window at 88 . Referring to FIG. 4B , at 90 , the current rates of change of the recent rate filter at 88 and the trial rate at 72 are computed, resulting in a delta rate (deltaRateFilt)at 92 .
[0043] Statistical hypothesis testing and data fusion are performed at 94 , for example, by a maximum likelihood decision engine (biosemBinaryQualifier, or BBQ), to determine the event type based on the biophysiological limits at 74 , the recent rate at 86 , the delta rate at 84 , the filter delta rate and the trial delta filter rate at 92 and statistical feedback data at 112 from FIG. 4C . The resultant event type at 96 , is forwarded to the process at FIG. 4C .
[0044] Referring to FIG. 4C , based on the event type at 96 in FIG. 4B , decision logic at 100 determines the hypothesis category, for example, type 0, type 1, or type 2. In an embodiment, the decision rule (decision logic) may be framed as a question, for example, “Should a newly observed feature (beat) be accepted as legitimate?” The question may be answered probabilistically, for example based on whether the feature lies within a certain confidence interval of each of the hypotheses, or alternatively by computing the chi-squared statistics associated with each of the hypotheses.
[0045] If the event type at 96 is determined to belong to a hypothesis category, type 0, no further processing is performed regarding the event type at 102 . If the event type 96 is determined to belong to a hypothesis category, type 1, the feature is passed along without modification at 104 . If the event type 96 is determined to belong to the category, type 2, the feature is modified according to a suitable model at 106 .
[0046] At 108 , the feature outputs at 104 and 106 are combined with the time at 70 of FIG. 4A to produce a qualified feature with a timestamp. The result for each timestamp is sent as an output at 110 , for example, including a postqualified feature, the corresponding hypothesis category or type. Optionally, a corresponding weight may be included in the output.
[0047] In addition, in an alternative embodiment, the final result may be temporally smoothed to improve the precision, albeit at the expense of responsiveness. For example, the feature stream may be estimated using various data smoothing approaches including, for example, a boxcar moving average filter, an exponential moving average filter, or the like. For example, the qualified feature stream and the smoothed feature stream provide two estimates of the true heart rate of a subject over time based on the measured heart rate data represented by the feature data streams.
[0048] Statistical data is computed based on the qualified feature with regard to a corresponding window of time at 112 , and the filter criteria is developed to update the recent rate filter at 88 in FIG. 4B . For example, a Langevin correction is made for time gaps in the data streams. In an embodiment, all of the required filtering criteria are determined at 112 . A corollary output is sent to a buffer at 114 , for example, including statistics such as the qualified feature mean and standard deviation with respect to the time window corresponding to each timestamp. The windowed statistics may be used, for example, to produce a confidence measure on the output qualified feature stream.
[0049] As illustrated in FIG. 5 , an exemplary computing device 120 may be employed in the biophysiological periodic data analyzer 10 of FIG. 1 includes a processor 122 , a memory 124 , an input/output device (I/O) 126 storage 128 and a network interface 130 . The various components of the computing device 120 are coupled by a local data link 132 , which in various embodiments incorporates, for example, an address bus, a data bus, a serial bus, a parallel bus, or any combination of these.
[0050] The computing device 120 may be used, for example, to implement the method of analyzing biophysiological periodic data of FIG. 1 . Programming code, such as source code, object code or executable code, stored on a computer-readable medium, such as the storage 128 or a peripheral storage component coupled to the computing device 120 , may be loaded into the memory 124 and executed by the processor 122 in order to perform the functions of the method of analyzing biophysiological periodic data of FIG. 1 .
[0051] Aspects of this disclosure are described herein with reference to flowchart illustrations or block diagrams, in which each block or any combination of blocks may be implemented by computer program instructions. The instructions may be provided to a processor of a general purpose computer, special purpose computer, or other programmable data processing apparatus to effectuate a machine or article of manufacture, and when executed by the processor the instructions create means for implementing the functions, acts or events specified in each block or combination of blocks in the diagrams.
[0052] In this regard, each block in the flowchart or block diagrams may correspond to a module, segment, or portion of code that including one or more executable instructions for implementing the specified logical function(s). It should also be noted that, in some alternative implementations, the functionality associated with any block may occur out of the order noted in the figures. For example, two blocks shown in succession may, in fact, be executed substantially concurrently, or blocks may sometimes be executed in reverse order.
[0053] A person of ordinary skill in the art will appreciate that aspects of this disclosure may be embodied as a device, system, method or computer program product. Accordingly, aspects of this disclosure, generally referred to herein as circuits, modules, components or systems, may be embodied in hardware, in software (including firmware, resident software, micro-code, etc.), or in any combination of software and hardware, including computer program products embodied in a computer-readable medium having computer-readable program code embodied thereon.
[0054] It will be understood that various modifications may be made. For example, useful results still could be achieved if steps of the disclosed techniques were performed in a different order, and/or if components in the disclosed systems were combined in a different manner and/or replaced or supplemented by other components. Accordingly, other implementations are within the scope of the following claims.
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A computer-implemented method for analyzing biophysiological periodic data includes receiving a stream of feature data points, determining whether each of the feature data points lies within or outside a predetermined limit, and eliminating a first subset of the feature data points in response to having determined that the each of the data points in the first subset lies outside the predetermined limit. The method further includes extracting a feature from the feature data points that lie within the predetermined limit over a time window, performing multiple hypothesis tests to determine whether or not the feature corresponds to a any of multiple hypothesis distributions, and qualifying the feature as a qualified estimate of an actual feature if the feature corresponds to statistical mean of a plurality of recent qualified estimates.
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BACKGROUND OF THE INVENTION
The borehole of producing oil and gas wells is typically lined from top to bottom with steel casing anchored by a sheath of cement that is securely and circumferentially bonded to both the casing and the wall of the wellbore. Offshore wells are sometimes abandoned with no equipment projecting above the water surface. Oftentimes wells are drilled at extreme depths with the drilled wellbore deviating sustantially from the vertical. There is, therefore, the need for a reliable method of locating the wellhead of such abandoned offshore wells or for locating the bottom of a deviated well, especially in the case of a well blowout when a relief well is to be drilled to intersect the deviated well at a point above or near the blowout. Other similar situations may arise when the exact location of the wellhead or well bottom is needed.
One of the methods that has been used in such well location efforts is by searching with a magnetometer for the magnetic anomaly created by the well casing. The natural magnetization of a well casing due to the earth's magnetic field produces an anomaly in the total magnetic field which may be detected with a sensitive magnetometer at distances up to a few hundred feet. The magnitude of the anomaly is proportional to the end steel area of the casing, the vertical component of the earth's field, the effective permeability, and is inversely proportional to the square of the distance from the wellhead or well bottom. However, the vertical component of the earth's magnetic field goes to zero at the magnetic equator. Thus, the reduced anomaly over about twenty percent of the earth's surface is difficult to impossible to detect.
SUMMARY OF THE INVENTION
In accordance with the present invention there is provided a method for magnetizing well casing by means of an internal magnetizer being advanced through the well casing to create a magnetic anomaly along such well casing. The direction of the magnetic field of the magnetizer travels through the well casing so as to create a plurality of magnetic flux leakage points along the well casing. The distance between the magnetic flux leakage points is such that a desired magnetic field strength is created along the well casing at a desired radial distance outward from the well casing. More particularly, the desired magnetic field strength is created at a radial distance outward from the well casing at least equal to the distance between the magnetic flux leakage points.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 illustrates a well casing being magnetized in accordance with the present invention.
FIG. 2 illustrates the magnetic anomaly created by the magnetized well casing of FIG. 1.
FIG. 3 illustrates the magnetic anomaly of the well casing of FIG. 1 as a function of distance into the formation surrounding the well casing.
DESCRIPTION OF THE PREFERRED EMBODIMENT
A typical wellbore 10 is shown in FIG. 1 lined with steel casing 11 and anchored by a sheath of cement 12 which is circumferentially bonded to both the casing 11 and the wall of the wellbore 13. An internal magnetizer, shown schematically at 14, is lowered into the casing by means of a suitable wireline cable (not shown). The magnetizer core may preferably be of soft iron wound with a number of layers of copper wire. Power is supplied to the magnetizer from an uphole power supply 15. The power can be applied to the magnetizer continuously as a D.C. voltage or can be applied in unipolar pulses from a storage capacitor. When the polarity of the power to the magnetizer is reversed, a magnetic pole develops in the casing 11. By causing these reversals to occur at several feet or more along the casing 11, a magnetic anomaly is created in the casing which can be detected by a flux gate magnetometer or other type magnetometer in a nearby wellbore being drilled or in a relief well being drilled to intersect the wellbore 10 in the event of a well blowout. With the polarity shown in FIG. 1, the magnetization last "felt" by the casing 11 will be in the upward direction as the magnetizer 14 is advanced upward through the casing.
More particularly, the anomaly created by the magnetization of the casing 11 may be as illustrated in FIG. 2 wherein a plurality of alternating N and S magnetic poles are spaced along the casing 11. The spacing L between such poles should be of sufficient distance to maximize the detection range of the casing from a relief well or other well into which a magnetometer is located. Although not to scale in FIG. 2, the monopole spacing L is much greater than the casing radius r. preferably the desired magnetic field strength is created at a radial distance outward from the well casing at least equal to the distance between the magnetic flux leakage points. FIG. 3 illustrates magnetic anomaly as a function of distance from the magnetized well casing for spaced magnetic monopoles of alternating polarity of 30 feet, 60 feet, 90 feet, 120 feet and 150 feet. It can be seen that as the spacing distance L between the monopoles is increased, the distance of detection of the anomaly from the well casing is increased. This is due to the fall of the magnetic field strength at the rate of 1/R 2 where R is the distance from the magnetometer in the relief or other wellbore to the magnetized well casing 11 in the wellbore 10 for example.
In one embodiment, the internal magnetizer 14 was comprised of an 18 inch Armco soft iron core of 11/4 inch diameter with a two layer winding of #16 copper wire. A monopole magnetic pole strength of 1.8×10 5 α-ft 2 (on 1.8×10 3 cmu) was produced with a 30 volt D.C. pulse supplied to the magnetizer from the capacitive discharge of the uphole power supply.
It is to be understood that the foregoing merely describes one embodiment of the present invention. Various modifications, as well as alternate embodiments, may become apparent to one skilled in the art without departing from the scope and spirit of the invention as hereinafter defined by the appended claims. For example, in lieu of magnetizing the well casing after it has been located and cemented in the wellbore, the casing could be magnetized on the earth's surface as it is being lowered into the wellbore. Also pulsed power may be utilized in magnetizing the casing in lieu of D.C. power.
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A well casing is magnetized by traversing an internal magnetizer along and within the well casing while periodically reversing the direction of the magnetic field of the magnetizer to create a plurality of magnetic flux leakage points along the well casing.
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BACKGROUND OF THE INVENTION
This invention relates to a method of dredging up sludge, which is deposited on the bottom of the water, continuously in a high density and sending the resultant sludge under pressure to a predetermined place, and an apparatus used to practice this method.
In order to remove the sludge deposited on the bottom of the water in, for example, a dam and a harbor, a method of sending up the sludge with the water by using a dredging pump is employed. However, according to this dredging method in which a large quantity of water is sent up with the sludge, large power and equipment are required.
Moreover, in order to separate sludge from the muddy water sent up by a dredging pump, it is necessary to secure a vast land to be reclaimed from the sea. It is difficult to carry out a dredging operation in a place where such a vast land to be reclaimed from the sea is not available. Since the separating of sludge from the muddy water is generally done in a small land to be reclaimed from the sea, a lot of time is required to carry out the operation.
In order to dredge up the sludge efficiently by using small power and a small land to be reclaimed from the sea, it is necessary that the sludge be brought up from the bottom of the water continuously in a high density. To meet this requirement, it is desirable to send up the sludge with the shape of the layer thereof kept as it originally was while preventing to as great an extent as possible the water from mixing in the sludge. In a dredging operation carried out with a view to achieving this purpose, various types of sludge sucking devices which suit the purpose are used. For example, suction devices based on a centrifugal pump system and a pneumatic pump system have been proposed.
In these systems, the sludge deposited on the bottom of the water is sent up by sucking the sludge as it is into the pump, or agitating the sludge to increase the fluidity thereof and sucking the resultant sludge, which is akin to muddy water, into the pump. Accordingly, the sucked sludge of an increased fluidity flows into the suction port along the flow of the muddy water. In case of sucked sludge having a fluidity close to that of water, a channel of water is formed early in the sludge in most cases except the case where the sludge has, for example, a water content of not lower than 200% (namely, a content of water two times as large as the weight of dry sludge). Therefore, a large quantity of water is sucked with sludge, i.e., water the quantity of which is far larger than that of the sludge is necessarily sent up, so that the dredging efficiency greatly decreases.
As may be inferred from such phenomena, it is very difficult to dredge up sludge continuously in a high density by utilizing these suction devices and a flow of the muddy water, due to the principle that the water flows more smoothly than sludge. This makes it necessary to use a large suction device and large power.
A dredging apparatus in which the air is supplied to the upper portion of a casing, which is opened horizontally and provided with a screw horizontally therein, so as to discharge the water has also been developed. However, in this apparatus, water with sludge is fed from the front portion of a casing. Therefore, it is impossible to send up sludge with a high efficiency as in the above-described apparatus made according to the known techniques.
SUMMARY OF THE INVENTION
The present invention has been made to give solution to the problem that according to the above described conventional dredging methods and apparatus, it is indispensable to transfer a large quantity of water with sludge, and its primary object is to make it possible to effect a continuous dredging of underwater sludge at a high density of the latter by way of forming an air chamber from which water is removed away, at the intended underwater bed, digging and scooping sludge at the underwater bed in the air chamber, using mechanical means such as a bucket wheel having an open bottom and peripheral scraping claws, and transferring the dug and scooped sludge out of water with its content of water suppressed as much as possible.
In the dredging apparatus according to the present invention, a hood is provided on the outer side of a cutter wheel, and the dredging of sludge is done as the cutter wheel is rotated in an air chamber formed by supplying compressed air into this hood.
This dredging apparatus consists mainly of a stationary chamber adapted to store the dredged sludge therein and send the sludge to a pump, and a cutter wheel adapted to be rotated along the outer circumference of the stationary chamber, and having a plurality of bottom-opened scraping claws implanted in a cutter wheel body.
In a conventional dredging apparatus, the sludge is fluidized, sucked and then sent up, while, in the apparatus according to the present invention, the sludge is dug out in the air chamber by buckets or scraping claws with the occurrence of the mixing of water in the sludge prevented to as great an extent as possible, the resultant sludge being then sent under pressure to a sludge treatment plant through a pipe line in such a manner that the water is not substantially mixed in the sludge.
In a preferred embodiment of the present invention, a cutter wheel having scraping claws (bottom-opened buckets) rotatable around a horizontal shaft is used as a sludge digging means. In short, the significance of the present invention resides in that the water is replaced by the air to form an air chamber, in which the sludge is dug out and sent up as the shape of the layer thereof is kept substantially as it originally was. However, it necessarily occurs that the dredged sludge contains water to some measure, since sludge containing a large quantity of water is dug out during an operation of this dredging apparatus.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a longitudinal sectional view, showing a whole of the dredging apparatus according to the present invention;
FIG. 2 is a cross-sectional view of the apparatus of FIG. 1, in which a left-hand half portion shows a front view of the cutter wheel in the apparatus and a right-hand half portion shows a front view in section of the cutter wheel and the interior of the storage tank mounted inner to the cutter wheel;
FIG. 3 is a plan view, showing the apparatus of FIG. 1 with the cutter wheel and the storage tank partly cut away and in section; and,
FIG. 4 shows a side elevational view, taken for illustration of a whole of a dredger equipped with the apparatus for dredging sludge in high density according to the present invention; and
FIG. 5 shows a top plan view of the dredger of FIG. 4.
DESCRIPTION OF THE PREFERRED EMBODIMENT
An embodiment of the present invention will now be described.
As shown in FIGS. 4 and 5, which are general construction diagrams of a dredger having an apparatus for dredging sludge in a high density, the dredger is provided at the front end portion of a dredger body 17 with a ladder 16 so that the ladder 16 can be moved pivotally in the vertical direction, and at the rear end portion thereof with a spud 14 fitted vertically therein. The spud 14 is moved vertically by a spud winch 21 and implanted in the seabed to be utilized as a fulcrum of a swinging movement of the dredger body 17. Two swing wires 15 are wrapped around rollers at the front end portions of the ladder 16 so as to extend to left and right. The dredger body 17 is swung reciprocatingly by moving these swing wires 15 by operating swing winches 22 and thereafter moved forward.
An apparatus 30 for dredging sludge in a high density is provided at the front end of the ladder 16, and it is adapted to dig out sludge as it is swung to left and right in accordance with the movements of the dredger body 17.
In this dredging apparatus 30, a cutter wheel 1 having a plurality of scraping claws 2 implanted radially in a cutter wheel body is fitted around the outer circumference of a sludge storage tank 3 closed at its front and rear sides and provided at its upper portion with an opening 23 from which sludge is introduced thereinto, as shown in FIGS. 1-3. The cutter wheel 1 is mounted rotatably on a shaft 4, and the power generated by a driving unit 5 is transmitted to the shaft 4 by utilizing a driving means, such as a chain sprocket, to rotate the cutter wheel 1 and carry out a dredging operation.
On the outer side of the outer circumferential portion of the cutter wheel 1, a semicylindrical hood 10 is provided, which is adapted to store supplied compressed air therein to form an air chamber. The cutter wheel 1 is rotated within the hood 10, and sludge is dredged in the air chamber.
The cutter wheel 1 comprises of a cylindrical member 1b fitted rotatably around the outer circumference of a circumferential wall 1a of the storage tank 3, a plurality of sludge inlets 13 provided at regular intervals along the surface of the cylindrical member 1b, and bottom-opened scraping claws 2 radially disposed in the portions of the sludge inlets 13.
The sludge storage tank 3 is a horizontally disposed cylindrical tank provided with an opening 23 at the upper portion thereof, and a sludge suction port 7 at the lower portion thereof. The shaft 4 for driving the cutter wheel 1 fitted around the outer circumference of this sludge storage tank 3 is provided thereon with agitator wings 6, which are rotated in the storage tank 3 to agitate the sludge introduced thereinto, and set the same ready to be sent up under pressure easily.
The sludge dug out by the scraping claws 2 as the cutter wheel 1 is rotated is supplied at the highermost portion of the sludge storage tank 3 into the opening 23 thereof through the bottom openings of the scraping claws 2. The sludge is then stirred by the agitator wings 6 in the storage tank 3 and transferred to pneumatic pumps 8 via the sludge suction port 7. A passage continuing from the sludge suction port 7 is provided therein with an auxiliary wing 9, whereby the sucked sludge is pressurized and transferred to the pneumatic pumps 8.
How to operate the dredging apparatus according to the present invention will now be described.
The substantially upper half portion of the cutter wheel 1, which is rotated around the fixed sludge storage tank 3 as mentioned above, is surrounded by the hood 10. The compressed air a sent from air compressors 18 on the dredger body 17 is supplied from an air supply port 11 provided in the hood 10, and discharged at a flow rate of not lower than a predetermined level from air discharge ports 12.
Accordingly, the portion of the cutter wheel which is exposed to the air and the sludge storage tank 3 form an air chamber (gaseous atmosphere) within the hood 10. Therefore, the entry of the water existing around the scraping claws 2 into the cutter wheel 1 and sludge storage tank 3 can be prevented while the sludge is dredged by the scraping claws 2.
When the cutter wheel 1 is driven by the driving unit 5 as mentioned above, the sludge m is dredged by the scraping claws 2, and lifted and introduced from the opening 23, which is provided at the upper portion of the sludge storage tank 3, into the interior of the same tank 3. As the cutter wheel 1, agitator wings 6 in the sludge storage tank 3 are rotated, so that the sludge m introduced thereinto is stirred by the agitator wings 6 and becomes softened to an increased fluidity, and it is then supplied to the sludge suction port 7 due to the pressure of the air a and the sludge-forwarding effect of the agitator wings 6
The sludge m in the sludge storage tank 3 is sucked from the sludge suction port 7, pressurized by the sludge pressurizing auxiliary wing 9, sent into a pump unit consisting of three pneumatic pumps 8, and then transferred under pressure from the upper side of the dredger body 17 to a sludge treatment plant (not shown) through a sludge discharge pipe line 19.
In each of the pneumatic pumps 8, a one-way valve V 1 is provided above the open end of a supply port 7a for the sludge m, and adapted to be opened by the pressure of the sludge m. When the sludge m is supplied with a compressed air supply port 20 opened to the atmospheric air via a three-way valve V 2 , the one way valve V 1 is opened, and the sludge m is supplied to the interior of a casing. When the casing is filled up with the sludge m, the three-way valve V 2 is shifted to a position in which the compressed air a can be supplied. When the compressed air a is supplied to the casing, the pressure thereof causes the sludge m to open a valve V 3 to send the sludge m under pressure to a predetermined place through the pipe line 19.
The apparatus 30 for dredging sludge in a high density, which is constructed as described above, has elements which enable the sludge m on the bottom of the water to be dredged continuously in a high density. This apparatus 30 has scraping claws 2 of a predetermined capacity, by which the sludge m is dug out and collected continuously.
The sludge is dug out by the scraping claws 2 with the cutter wheel 1 rotated around the outer circumference of the sludge storage tank 3, and it is then supplied to the air chamber A from which the water has been discharged by the compressed air a supplied to the interior of the hood 10. The sludge m in the sludge storage tank 3 is agitated and receives a differential pressure due to the depth of the water substituted by the compressed air a. The sludge is then further pressurized by the auxiliary wing 9 provided in the sludge suction port 7, and supplied into the casing of each pump 8. The sludge m supplied to the interior of the pump 8 is pressurized with the compressed air a and discharged.
The above-described dredging operation is carried out as the apparatus 30 is moved laterally by drawing the swing wires 15, the lateral movement of the apparatus 30 being made around the spud 14 provided at the rear end of the dredger body 17.
The scraping claws 2 provided in the circumferential portion of the cutter wheel 1 dig out the deposited sludge and take the same in the sludge storage tank 3 as they are moved in the above-mentioned manner. The sludge, which has been dug out in the air chamber A in the hood 10, in the scraping claws 2 is discharged to the sludge storage tank 3, so that the water existing around the hood 10 is not mixed in the sludge m. Accordingly, only the sludge m on the bottom of the water enters the storage tank 3, and a very small quantity of water, if any, is mixed in this sludge. Therefore, sludge having a water content far lower than that of the sludge dug out by a conventional dredging method is dredged and transferred to a treatment plant.
The sludge thus taken in the sludge storage tank 3 is stirred by the agitator wing 6. The fluidity of the sludge m is improved, and this sludge is pushed by the air pressure in the storage tank 3 to flow through the sludge suction port 7. The sludge is then pressurized by the auxiliary wing 9, and flows into the pneumatic pumps 8.
The sludge m thus supplied to each pneumatic pump 8 is discharged to a treatment plant through the pipe line 19 by the compressed air a from the compressed air supply port 20. A dredging operation is carried out in this manner.
The sludge deposited on the bottom of the water is thus dug out by the cutter wheel 1 in the dredging apparatus 30, taken in the pumps 8 and then discharged therefrom. Therefore, the possibility that the water is mixed in the dredged sludge can be kept extremely low. This enables the sludge to be dredged continuously in a high density.
Since the dredging apparatus 30 in this embodiment is provided with an auxiliary wing 9 for pressurizing the sludge m from the sludge tank 3 and sending the resultant sludge to the relative pump 8, the generation of the force for forwarding the sludge m to the interior of the pump 8 is promoted by the sludge sucking and pressurizing effect of the auxiliary wing 9 even when a pressure difference required to forward the sludge into the pump 8 is not so large due to the small depth of the water in which the dredging operation is carried out.
In the above-described embodiment, the cutter wheel 1 having scraping craws implanted in the circumferential portion thereof is mounted on a horizontal shaft and rotated therearound. Some other type of cutter, for example, a screw type cutter can also be used as long as it is capable of forming an air chamber in a sludge digging portion thereof.
The hood consists of a metal or a reinforced synthetic resin. If elastic sheets consisting of rubber are provided at the lower edge portions of the hood as parts functioning as packings, so as to form an air chamber effectively, superior effect can be obtained.
In the apparatus for dredging sludge in a high density according to the present invention, sludge is collected in an air chamber by digging out the bottom of the water mechanically by a cutter wheel which is capable of digging out the sludge deposited on the bottom of the water. Therefore, the collecting of sludge can be done reliably. In addition, since the dredged sludge is introduced into the sludge storage tank which is adapted to prevent water from entering, the sludge can be collected without permitting the environmental water around the hood to enter the sludge.
The air pressure in the air chamber formed in the interior of the hood is applied as it is to the sludge surface in the sludge storage tank. This enables the dredged sludge to be sent up continuously in a high density with a high efficiency.
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A method of and apparatus for continuously dredging sludge deposited on an underwater bed, at a high density of the sludge, according to which digging and scooping devices are placed in an airtight hood opened at its bottom, which is applied on the intended underwater bed and into which air is then introduced to obtain a condition in which water is removed out of the hood, and the digging and scooping devices are then put into operation, whereby dredging is effected at a high efficiency in that the content of water in sludge being dredged is suppressed to a minimum, the sludge being transferred under pressure in a state of containing substantially no additional water than it naturally contains.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a method for linking segments and a linking tool, and more particularly to a method for linking segments that are used as an assembly unit of a pipe for rehabilitating existing pipes or pipelines, and to a linking tool used in this method.
2. Description of the Related Art
In cases where sewage pipes or other pipelines that are buried underground have aged, methods for constructing a pipe lining have already been proposed and are being employed in practical applications.
With the aforementioned methods for constructing a pipe lining, a pipe-lining material, which is formed, e.g., by impregnating a tubular resin-adsorbent material with an uncured thermosetting resin, is inserted into a pipeline via fluid pressure while being everted, and the impregnated thermosetting resin is cured by heating the pipe-lining material in the state where the pipe-lining material is pressed against the inner circumferential wall of the pipeline by fluid pressure. This allows a plastic pipe to be installed within the pipeline to be repaired.
In another well-known method for repairing a pipeline using a rehabilitating pipe (Japanese Laid-open Patent Application Nos. 2003-286742 and 2005-299711), a segment made of a plastic material is used which is integrally composed of an internal surface plate that constitutes the inner circumferential surface of the rehabilitating pipe and an outer-wall plate that is vertically disposed on the peripheral edges of the internal surface plate. Segments are linked in the circumferential direction to assemble pipe units, which are then linked in the longitudinal direction of the pipe via a linking member to assemble the rehabilitating pipe. This method is used for large-bore pipelines.
When linked together in the longitudinal direction of the pipe as disclosed in Japanese Laid-open Patent Application Nos. 2003-286742 and 2005-299711, the segments are linked using a linking tool provided with a screw. A screw-fastening tool is therefore necessary, and time is required to tighten the screw. The screw may not be able to be turned when the operation is performed in confined spaces; moreover, the operation is troublesome and repetitive even when the screw can be turned. A significant burden is therefore placed on the worker, resulting in lengthened operational time.
SUMMARY OF THE INVENTION
It is therefore an object of the present invention to provide a method for linking segments, and a linking tool, whereby segments can be efficiently linked in the longitudinal direction of the pipe in a short period of time using a simple method.
The present invention provides a method for linking segments for a rehabilitating pipe for rehabilitating an existing pipeline. The segment is integrally formed at least from an internal surface plate that constitutes the inner circumferential surface of the rehabilitating pipe, and side plates that have an insertion hole formed thereon and are disposed on both sides of the internal surface plate so as to extend in the circumferential direction of the rehabilitating pipe. The method for linking the segments comprises the steps of preparing a linking pin that can be separated into pin halves by a separating pin; inserting the linking pin into the insertion hole in the side plate of a first segment with a part of the linking pin remaining outside the first segment; separating the linking pin into the pin halves by the separating pin, the separated pin halves being pressed against the first segment, thereby anchoring the pin halves to the first segment; and snap-fitting the pin halves remaining outside the first segment into a second segment through the insertion hole of the side plate thereof, thereby linking the first and second segments in the longitudinal direction of the rehabilitating pipe.
A linking tool according to the present invention comprises a tubular linking pin that is separable into pin halves and can be inserted into the insertion hole in the side plate of a first segment with a part of the linking pin remaining outside the first segment; and a separating pin that can be inserted into the tubular linking pin to separate the linking pin into the pin halves and press them against the first segment for anchoring thereto. The pin halves remaining outside the first segment are snap-fitted into a second segment through the insertion hole of the side plate thereof, thereby linking the first and second segments in the longitudinal direction of the rehabilitating pipe.
According to the present invention, a linking pin, which is inserted into the insertion hole of the side plate of a segment, is separated into pin halves by a separating pin. The pin halves are pressed against the segment, thereby anchoring the linking pin to the segment. The other end of the linking pin outside the segment is snap-fitted into another segment, allowing the two segments to be linked in the longitudinal direction of the rehabilitating pipe. Screw-fastening is therefore unnecessary, and the segments can be assembled in confined spaces where a manual screwing motion is difficult to perform. The assembly operation can be simplified and shortened even during assembly in open spaces. Excellent effects are obtained in that construction time is shortened, the burden on workers is lightened, and the number of workers required is reduced even during a construction work for assembling a rehabilitating pipe using the segments to repair an existing pipeline.
Further features of the invention, its nature and various advantages will be more apparent from the accompanying drawings and following detailed description of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of a segment shown partially broken and partially in cross-section;
FIG. 2 is a perpendicular cross-sectional view of two segments, as seen when both segments are linked in the circumferential direction;
FIG. 3 is a perspective view of a pipe unit wherein the segments are linked in the circumferential direction to provide the pipe unit;
FIG. 4 a is a perspective view of a linking tool;
FIG. 4 b is a perspective view of the linking tool, as viewed when it is disassembled;
FIG. 4 c is a vertical cross-sectional view of the linking tool;
FIG. 5 a is a lateral view of the linking tool in which linking pin halves have been spread apart horizontally;
FIG. 5 b is a lateral view of the linking tool showing a state in which the linking pin halves are folded together and overlaid;
FIG. 6 is a cross-sectional view showing the dimensions of the linking pin, the separating pin, the side plate of the segment, and the internal plate thereof;
FIG. 7 a is a plan view showing a state in which the linking tool is ready for insertion into a segment;
FIG. 7 b is a plan view in which the linking tool is inserted and anchored to the segment;
FIG. 8 a is a cross-sectional view in which the linking pin is inserted to the forward part of the internal plate of the segment;
FIG. 8 b is a cross-sectional view in which the linking pin is inserted to the insertion hole of the internal plate of the segment;
FIG. 8 c is a cross-sectional view showing a state in which the separating pin is pressed in, and the linking pin is separated into the linking pin halves;
FIG. 8 d is a cross-sectional view in which the separating pin has been pushed further in;
FIG. 8 e is a cross-sectional view in which the linking pin is pushed into the insertion hole of the side plate of another segment;
FIG. 8 f is a cross-sectional view in which two segments have been linked by the linking pin;
FIG. 9 a is a plan view in which two segments are being linked by the linking pin;
FIG. 9 b is a plan view in which both segments have been linked;
FIG. 10 is a cross-sectional view along a segment arc, in which segments are linked in the longitudinal direction of the pipe via the linking tool and the linking rod;
FIG. 11 is an illustrative view showing a state in which a rehabilitating pipe composed of the segments is laid in an existing pipeline; and
FIG. 12 is a perspective view showing the exterior of the rehabilitating pipe laid within the existing pipeline.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
The present invention will be described in detail hereinafter on the basis of the embodiments shown in the accompanying drawings.
FIG. 1 shows a segment 1 that serves as an assembly unit for a pipe for rehabilitating an existing pipe such as a sewerage pipe, a waterworks pipe, an agricultural water pipe and the like. The segment 1 is a block-shaped member that is integrally formed of plastic from an internal surface plate 101 that constitutes an inner circumferential surface of the rehabilitating pipe; side plates 102 , 103 that are vertically disposed at both sides of the internal surface plate 101 so as to extend in the circumferential direction of the rehabilitating pipe; and end plates 104 , 105 that are vertically disposed at both ends of the internal surface plate 101 so as to extend in the longitudinal direction of the pipe. The side plates 102 , 103 and the end plates 104 , 105 of the segment 1 have the same height and form an outer-wall plate that surrounds the rim of the internal surface plate 101 on all four sides. The widths (thicknesses) of the side plates 102 , 103 of the segment 1 in the longitudinal direction of the pipe have the same value. The segment 1 has a shape bent into an arc shape of a predetermined angle that divides the circumference of a circle into a plurality of equal parts, e.g., five equal parts of 72 degrees each. The segment is not limited to arc or fan shapes, however, and may also be another shape, such as a bent shape obtained by rounding off a cuboid or right angle, in accordance with the shape of the cross-section of the existing pipe, the size thereof, and the location of the existing pipe to be repaired.
A plurality of internal plates (reinforcement plates) 106 , 107 that are similar to the side plates are provided vertically on the upper surface of the internal surface plate 101 inside the side plates 102 , 103 in order to reinforce the mechanical strength of the segment 1 . Convex plates 103 b , 106 b , 107 b that project laterally are formed at a plurality of locations on both lateral surfaces of the internal plates 106 , 107 and the inner lateral surfaces of the side plates 102 , 103 in order to prevent deformations thereof, resulting in a ribbed structure and increasing the strength of the segment 1 .
A plurality of circular or substantially circular insertion holes 102 a , 103 a are formed in the circumferential direction at equal intervals on the side plates 102 , 103 so that a linking tool can be inserted. The linking tool links the segments in the longitudinal direction of the pipe, as described hereinafter. A plurality of circular or substantially circular insertion holes 106 a for inserting the linking tool are also formed in the internal plates 106 in positions corresponding to the insertion holes 102 a , 103 a of the side plates 102 , 103 when viewed in the longitudinal direction of the pipe. The diameter of the insertion holes 106 a is smaller than the diameter of the insertion holes 102 a , 103 a , as described hereinafter. A plurality of notches 107 a are formed on the internal plates 107 in positions that correspond to the respective insertion holes 102 a , 103 a of the side plates 102 , 103 .
The internal surface plate 101 , the side plates 102 , 103 , the end plates 104 , 105 , as well as the internal plates 106 , 107 and the convex plates that function as reinforcement plates for these parts, are all made of the same clear, translucent, or opaque plastic and are formed integrally using well-known molding techniques.
A plurality of rectangular opening parts 101 a are formed on the ends of the internal surface plate 101 on the sides having the end plates 104 , 105 so that the operation for linking the segments 1 in the circumferential direction can be performed from the inside.
The segments 1 are linked in the circumferential direction by bringing the outer surfaces of the end plates 104 and 105 of each of the segments 1 in close contact with one another, inserting bolts 6 into insertion holes 104 a , 105 a from the opening parts 101 a of the internal surface plate 101 , threading on nuts 7 , and fastening together both of the end plates 104 , 105 , as shown in FIG. 2 . Concave parts 104 b , 104 c and convex parts 105 b , 105 c for fitting to the respective concave parts 104 b , 104 c are formed across the entire length of the end plates 104 and 105 in the longitudinal direction of the pipe. Both segments can therefore be readily held in position and brought into close contact during the linking operation. A sealant (not shown) is applied to the parts to be fit, whereby the water-tightness of the linking parts can be increased.
Once the linkage of the segments 1 in the circumferential direction is completed, the opening parts 101 a are sealed shut using a lid (not shown) or the like. The bottom surface of the lid in such instances is continuous with the bottom surface of the internal surface plates 101 , and the inner surfaces (the surfaces facing the center of the pipe) of the internal surface plates 101 form a uniform surface.
The segments 1 are linked in the circumferential direction so that the inner surfaces of the internal surface plates 101 form a uniform surface, and so that the outer surfaces of the respective side plates 102 , 103 all form a single surface. A closed, ring-shaped pipe body 10 (referred to as a pipe unit hereinafter) having a short, predetermined length can therefore be assembled when the segments 1 are sequentially linked in the circumferential direction, as shown in FIG. 3 . The pipe unit 10 has a shape obtained by cutting a round pipe perpendicularly with respect to the longitudinal direction X thereof with a predetermined width D. The outside diameter of the pipe unit is smaller than the inside diameter of the existing pipeline to be repaired. The segments 1 correspond to the members that are obtained when the pipe unit 10 is cut along a radial direction R and divided into a plurality of pieces (five in the embodiment in the drawings).
The internal surface plates 101 , the side plates 102 , 103 , and the end plates 104 , 105 , which are the primary structural members of the segment, are shown in FIG. 3 . The internal plates 106 , 107 , the convex plates, other reinforcing structures, the insertion holes 102 a , 103 a , and the like are omitted from FIG. 3 in order to avoid complexity.
A linking tool 20 for linking the segments 1 or the pipe units 10 in the longitudinal direction of the pipe is shown in FIGS. 4 a through 4 c and 5 a , 5 b . The linking tool 20 comprises a tubular hollow linking pin 21 and a separating pin 24 . The linking pin has a hollow part constructed from overlaying linking pin halves 22 , 23 , and the separating pin separates the linking pin 21 into the linking pin halves 22 , 23 . The linking pin 21 has a shape formed integrally of plastic, in which the linking pin halves 22 , 23 are linked by thin parts 22 a , 23 a , as shown in FIG. 5 a . As shown in FIG. 5 b , the linking pin 21 can be bent at the thin parts 22 a , 23 a and folded. The linking pin thereby becomes a tubular pin having a structure in which the linking pin halves 22 , 23 are overlaid as shown in FIG. 4 a.
As shown in FIGS. 4 b , 4 c , the linking pin half 22 has the thin part 22 a that links to the linking pin half 23 ; a half-pipe part 22 c having a shape obtained when the portion of a circular tube above a pipe axis x 1 is cut off in the horizontal direction; a projecting part 22 b that has a half-pipe shape having a small diameter and that projects farther toward the distal end than the half-pipe part 22 c ; a first protruding part 22 d and a second protruding part 22 e that extend in the circumferential direction over the outer circumferential surface of the half-pipe part 22 c ; and a slanted part 22 f . The mutually facing surfaces of the first and second protruding parts 22 d and 22 e are vertical, while the opposite portions thereof are slanted and are continuous with the half-pipe part 22 c.
The linking pin half 23 is shaped to be laterally symmetric with the linking pin half 22 when viewed as in FIG. 5 a . The linking pin half 23 has the thin part 23 a , a projecting part 23 b , a half-pipe part 23 c , a first protruding part 23 d , a second protruding part 23 e , and a slanted part 23 f that correspond respectively to the thin part 22 a , the projecting part 22 b , the half-pipe part 22 c , the first protruding part 22 d , the second protruding part 22 e , and the slanted part 22 f of the linking pin half 22 .
The linking pin halves 22 , 23 have shapes that would result from horizontally cutting off a circular tube a predetermined small distance above (or below) a horizontal plane that passes through the central axis of the circular tube. The moderately flat, tubular linking pin 21 , which has an ellipsoid cross section, is therefore obtained when the linking pin halves 22 , 23 are overlaid as shown in FIG. 4 a.
As shown in FIG. 4 c , when the linking pin halves 22 , 23 are overlaid, a hollow part 21 a having a small diameter and a hollow part 21 b having a larger diameter are formed on the inside of the linking pin. The thickness of the linking pin halves 22 , 23 decreases beyond the first protruding parts 22 d , 23 d toward the end (the right side) of the linking pin. A hollow part 21 c having a larger diameter than the hollow part 21 b is therefore formed.
The separating pin 24 is a cylindrical pin of plastic or metal and has a conical distal part 24 a , a cylindrical distal part 24 b , a cylindrical center part 24 c , and a cylindrical proximal part 24 d.
The dimensions of the segment 1 , the separating pin 24 , and the linking pin 21 obtained when the linking pin halves 22 , 23 are overlaid are shown in FIG. 6 .
A diameter D 2 of the circular insertion hole 103 a formed in the side plate 103 of the segment 1 is larger than a diameter D 1 of the circular insertion hole 106 a of the internal plate 106 adjoining the side plate 103 . The size of the linking pin 21 allows the projecting parts 22 b , 23 b of the linking pin to pass through the insertion hole 106 a of the internal plate 106 with a predetermined spacing, and allows the half-pipe parts 22 c , 23 c to pass through the insertion hole 103 a of the side plate 103 with a substantially identical spacing. The first protruding parts 22 d , 23 d of the linking pin 21 are slanted on the inserting side (the left side) and protrude outwardly so high as to be able to pass through the insertion hole 103 a due to its elasticity if forcefully pressed. The second protruding parts 22 e , 23 e of the linking pin 21 are also of an identical size and have lateral symmetry with the first protruding parts 22 d , 23 d.
A distance t 1 from a boundary surface S 1 between the projecting parts 22 b , 23 b and the half-pipe parts 22 c , 23 c of the linking pin 21 to a vertical surface S 2 of the first protruding parts 22 d , 23 d is approximately equal to the distance between the opposing surfaces of the side plate 103 and the internal plate 106 of the segment 1 . A distance t 3 between opposing vertical surfaces S 2 , S 3 of the first protruding parts 22 d , 23 d and the second protruding parts 22 e , 23 e is approximately double a thickness t 2 of the side plate 103 (or the side plate 102 ) of the segment 1 in the longitudinal direction of the pipe.
The outside diameters of the distal part 24 b , the center part 24 c , and the proximal part 24 d of the separating pin 24 are p 1 , p 3 , and p 2 , respectively, where p 3 >p 2 >p 1 .
When the linking pin halves 22 , 23 are in an overlaid state, the size of the center part 24 c of the separating pin 24 allows the center part to be housed in the hollow part 21 c of the linking pin 21 but does not allow insertion into the hollow part 21 b . The size of the distal part 24 b of the separating pin 24 also prevents insertion into the hollow part 21 a of the linking pin 21 . However, when pressure is applied and the separating pin 24 is pushed in, the center part 24 c of the separating pin 24 is pressed into the hollow part 21 b of the linking pin 21 , and the size of the distal part 24 b of the separating pin 24 now allows the separating pin to be pressed into the hollow part 21 a of the linking pin 21 . When the center part 24 c of the separating pin 24 is pressed into the hollow part 21 b of the linking pin 21 , and the distal part 24 b of the separating pin 24 is pressed into the hollow part 21 a of the linking pin 21 , the linking pin 21 is pushed apart, and the joining parts 22 a , 23 a of the linking pin 21 are split. This causes the linking pin 21 to be separated into the linking pin halves 22 , 23 . The separated linking pin halves 22 , 23 are pressed against the insertion holes 103 a , 106 a of the side plate 103 and the internal plate 106 of the segment 1 by the separating pin 24 .
A method for linking segments in the longitudinal direction of the pipe using a linking tool configured in this manner will be described next.
With the linking pin halves 22 , 23 overlaid and the separating pin 24 housed inside the linking pin 21 , as shown in FIGS. 4 a , 4 c , the linking pin 21 is inserted into an insertion hole 103 a in the side plate 103 of the segment 1 , as shown in FIG. 7 a.
The half-pipe parts 22 c , 23 c of the linking pin 21 can pass through the insertion hole 103 a of the side plate 103 of the segment 1 , and the projecting parts 22 b , 23 b can pass through the insertion hole 106 a of the internal plate 106 . The linking pin 21 is therefore inserted into the insertion holes 103 a , 106 a with a predetermined spacing, as shown in FIG. 8 a . The insertion sides (the left side) of the first protruding parts 22 d , 23 d of the linking pin 21 are slanted, and therefore, if the separating pin 24 is forcefully pushed, the first protruding parts 22 d , 23 d will pass through the insertion hole 103 a due to the elasticity of the linking pin 21 , as shown in FIG. 8 b . The distance t 1 from the boundary surface S 1 between the projecting parts 22 b , 23 b and the half-pipe parts 22 c , 23 c to the vertical surface S 2 of the first protruding parts 22 d , 23 d is equal to the distance between the opposing surfaces of the side plate 103 and the internal plate 106 . The boundary surface S 1 therefore contacts the inside surface of the internal plate 106 , and the vertical surface S 2 contacts the inside surface of the side plate 103 .
As shown in FIGS. 8 c , 8 d , when the proximal part 24 d of the separating pin 24 is pushed in, the center part 24 c of the separating pin 24 is pressed into the hollow part 21 b of the linking pin 21 , and the distal part 24 b of the separating pin 24 is pressed into the hollow part 21 a of the linking pin 21 . The linking parts 22 a , 23 a are then split, and the linking pin 21 is separated into the linking pin halves 22 , 23 . The separated linking pin halves 22 , 23 are thus pushed apart by the separating pin 24 , the projecting parts 22 b , 23 b of the linking pin 21 are pressed against the insertion hole 106 a of the internal plate 106 , and the half-pipe parts 22 c , 23 c thereof are pressed against the insertion hole 103 a of the side plate 103 . The linking pin is thereby anchored to the segment 1 . The boundary surface S 1 of the half-pipe parts 22 c , 23 c is pressed against the inside surface of the internal plate 106 at this point, and the vertical surface S 2 of the first protruding parts 22 d , 23 d is pressed against the inside surface of the side plate 103 . The linking pin 21 is therefore reliably anchored to the segment 1 , and the linking pin 21 can be prevented from passing back through the insertion hole 103 a of the side plate 103 of the segment 1 and detaching therefrom. This state is also shown in FIG. 7 b.
Next, as shown in FIGS. 8 e and 8 f , the end opposite the inserted end of the linking pin 21 , which has been separated into the linking pin halves 22 , 23 , is inserted into the insertion hole 102 a of the side plate 102 of another segment 1 ′. The linking pin halves 22 , 23 are separated and flex to the inside, and are therefore readily inserted. The side plate 102 slides over the slanted surfaces of the second protruding parts 22 e , 23 e , and the side plate 102 of the segment 1 ′ and the linking pin 21 are snapped together and anchored. The distance between the opposing vertical surfaces S 2 , S 3 of the first protruding parts and the second protruding parts is approximately twice the thickness of the side plate 103 ( 102 ), and therefore the side plate 102 of the segment 1 ′ is anchored in a state of being pressed between the vertical surface S 3 of the second protruding parts 22 e , 23 e and the side plate 103 of the segment 1 . The segment 1 ′ is prevented from detaching from the linking pin 21 by the second protruding parts 22 e , 23 e . The segment 1 ′ is thus anchored to the segment 1 by the linking pin 21 , and therefore the segments 1 and 1 ′ can be firmly linked in the longitudinal direction of the pipe.
FIGS. 9 a , 9 b show the linkage of the segments 1 , 1 ′ via the linking tool 20 as viewed from above.
The cross-section of the linking pin can be made into a hexagonal or other polygonal shape instead of a tubular shape. The shapes of the insertion holes of the internal plates and the side plates of the segments are formed accordingly in such instances. The first and second protruding parts of the linking pin may also be formed around the entirety of the linking pin in the circumferential direction or may be formed intermittently in the circumferential direction.
A plurality of the insertion holes ( 102 a , 103 a , 106 a ) for the linking tool of the segments is formed along the circumferential direction of the side plates and the internal plates, as shown in FIG. 1 . The linking tool 20 is therefore inserted into a predetermined number of the plurality of the insertion holes, and the segments are linked in the longitudinal direction of the pipe by the linking tools. However, the linking tools 20 that link the segments are short, and therefore the linkage is weak. A linking rod that extends along the width of the segment in the longitudinal direction of the pipe is therefore inserted into the insertion hole of the segment, and one end of the linking rod is joined to the other end of a linking rod that has already been anchored to another segment, as disclosed in Japanese Laid-open Patent Application No. 2005-299711. The linking rod is thereby affixed to the segment, and the segment is thereby linked to another segment in the longitudinal direction of the pipe via the linking rod. This state is shown in FIG. 10 .
Segments 1 , 1 ′, 1 ″ are partially linked via the linking tools 20 in FIG. 10 . A metal anchoring nut 32 is inserted into the side plate 103 of the segment 1 and the side plate 102 of the segment 1 ′. A metal bolt 33 is screwed through the internal plates 106 of the segment 1 into the anchoring nut 32 , whereby the anchoring nut 32 is anchored to the segment 1 .
An axle part 31 b of a metal linking rod 31 that extends across both of the side plates 102 , 103 of the segment has a screw part 31 a on one end and a nut part 31 c , which has a screw 31 d on the inside, on the other end.
The linking rod 31 is passed through the insertion holes of the side plates and the internal plates of the segment 1 ′, and the portion of the nut part 31 c that juts out from the side plate 103 of the segment 1 ′ is rotated, whereby the screw part 31 a of the linking rod 31 is screwed into the anchoring nut 32 . The linking rod 31 is screwed in until the end of the nut part 31 c on the insertion side presses against the internal plate 106 . This causes the linking rod 31 to be anchored to the segment 1 ′, and the segment 1 ′ is linked and fastened to the segment 1 by the linking rod 31 . The nut part 31 c of the linking rod 31 of the segment 1 ′ performs the function of the anchoring nut 32 affixed to the segment 1 , and therefore the segment 1 ″ can be linked to the segment 1 ′ using another linking rod 31 in the same manner. A plurality of the segments can be sequentially linked in the longitudinal direction of the pipe via the linking rods by repetition of the same procedure.
A method for rehabilitating an existing pipeline using the segments will be described below.
The segments 1 are first transported into an existing pipeline 41 via a manhole 40 , as shown in FIG. 11 . The segments 1 are then sequentially linked in the circumferential direction to assemble the pipe units 10 , as shown in FIG. 3 .
The pipe units 10 are assembled in the same manner and then linked to previously assembled pipe units 10 in the longitudinal direction of the pipe. The pipe units 10 are linked by linking the segments 1 of the pipe units 10 using the above-mentioned linking tools 20 and/or linking rods 31 .
The pipe units 10 are sequentially linked in the longitudinal direction of the pipe inside the existing pipeline 41 as described above, whereby a rehabilitating pipe 42 can be laid inside the existing pipeline 41 . This state is shown in FIG. 12 . As in FIG. 3 , only the essential components are shown in FIG. 12 . The linking tools, linking rods, and other means for linking in the longitudinal direction of the pipe or in the circumferential direction have been omitted in order to avoid complexity.
A gap 43 is present between the outer circumferential surface of the rehabilitating pipe 42 and the inner-wall surface of the existing pipeline 41 . A grouting material or other filler is therefore poured into the gap 43 to make the rehabilitating pipe 42 and the existing pipeline 41 integrated. The assembly of the pipe unit 10 in the present embodiment is such that the end plates of the segments thereof are offset from the end plates of the segments in other pipe units, but the assembly may also be such that the respective end plates are aligned. FIG. 9 shows an example of an assembly in which the end plates of the segments are aligned.
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A linking tool links segments for a rehabilitating pipe for rehabilitating an existing pipeline. The segment is integrally formed at least from an internal surface plate that constitutes the inner circumferential surface of the rehabilitating pipe, and side plates that have an insertion hole formed thereon and are disposed on both sides of the internal surface plate so as to extend in the circumferential direction of the rehabilitating pipe. The linking tool includes a tubular linking pin that is separable into pin halves and can be inserted into the insertion hole in the side plate of a first segment with a part of the linking pin remaining outside the first segment. The linking tool further includes a separating pin that can be inserted into the linking pin to separate the linking pin into the pin halves and press them against the first segment for anchoring thereto. The pin halves remaining outside the first segment are snap-fitted into a second segment through the insertion hole of the side plate thereof, thereby linking the first and second segments in the longitudinal direction of the rehabilitating pipe. Such a linking tool allows the segments to be efficiently linked in a short period of time.
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CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application is a divisional application of co-pending U.S. patent application Ser. No. 12/832,104 filed Jul. 8, 2010, which is a divisional application of U.S. patent application Ser. No. 11/371,357 filed Mar. 8, 2006, now U.S. Pat. No. 8,033,899, which claims priority to JP2005-251643, JP2005-251644, and JP2005-251645, each filed Aug. 31, 2005.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention is directed to a cabin for a work vehicle, and more particularly to an air-conditioning unit within the cabin roof.
[0004] 2. Description of Related Art
[0005] For arranging the air-conditioning unit, the forward half of the roof is formed as a low ceiling portion bulging downward. The air-conditioning unit is arranged in a front portion of the low ceiling portion (e.g., JP Publication No. 2005-1537 (paragraph number [0016], FIG. 1 and FIG. 2).
[0006] In the above construction, the roof includes a low ceiling portion that accommodates the air-conditioning unit. This leads to narrowing of an upper forward field of view. Then, when performing a front loader operation, the driver seated on the driver's seat has difficulty in ascertaining a position of the bucket near an upper position, resulting in a possibility of lowering working efficiency.
SUMMARY OF THE INVENTION
[0007] The object of this invention is to provide an air-conditioning structure for a cab of a working vehicle with an improved upper forward view by providing a better arrangement for the air-conditioning unit.
[0008] A cabin for a work vehicle in accordance with the present invention comprises: a driver's seat positioned within the cabin; cabin frames including at least a transverse frame located in a rear region of the cabin; a roof supported by at least some of the cabin frames; at least one air-conditioning duct located within the roof; an air-conditioning unit located rearwardly with respect to a rearward end of a seat portion of the driver's seat and adjacent the transverse frame for conditioning air and for feeding air-conditioned air into the at least one air-conditioning duct.
[0009] Since the air-conditioning unit is disposed rearwardly with respect to the rear end of the seat portion of the driver's seat, a low ceiling portion for accommodating the air-conditioning unit need not be formed in a front portion of the roof of the cabin. A windshield position can be set high. As a result, an improved upper forward field of view is provided.
[0010] Moreover, since the position of the air-conditioning unit is set rearwardly of the rear end of the seat portion of the driver's seat, a low ceiling portion formed in the rear of the roof in order to accommodate the air-conditioning unit would not diminish the forward field of view of the driver seated on the driver's seat, but can alleviate a narrowing of overhead space.
BRIEF DESCRIPTION OF THE DRAWINGS
[0011] FIG. 1 shows a side elevation of a tractor;
[0012] FIG. 2 shows a perspective view showing a structural framework in a first embodiment;
[0013] FIG. 3 shows a side view in vertical section showing a cabin interior in the first embodiment;
[0014] FIG. 4 shows a plan view in cross section showing an inner surface of an inner roof portion seen from an outer roof in FIG. 2 ;
[0015] FIG. 5 shows a front view showing a duct disposed laterally of a roof;
[0016] FIG. 6 shows a perspective view showing a structural frame in a second embodiment;
[0017] FIG. 7 shows a side view in vertical section side showing a mounting structure for an air-conditioning unit in the second embodiment;
[0018] FIG. 8 shows a perspective view showing a structural framework in a third embodiment;
[0019] FIG. 9 shows a side view in vertical section side showing a mounting structure for an air-conditioning unit in the third embodiment;
[0020] FIG. 10 shows a perspective view showing a structural framework in a fourth embodiment;
[0021] FIG. 11 shows a side view in vertical section side showing a mounting structure for an air-conditioning unit in the fourth embodiment;
[0022] FIG. 12 shows a plan view in cross section showing a different embodiment of the air-conditioning duct;
[0023] FIG. 13 shows a plan view in cross section showing a different embodiment of the air-conditioning duct;
[0024] FIG. 14 shows a rear view showing an arrangement of the air-conditioning duct in FIG. 13 ;
[0025] FIG. 15 shows side view in vertical section side showing an upper frame serving also as a duct;
[0026] FIG. 16 (A) shows a perspective view showing upper ends of front posts higher than fore and aft frames;
[0027] FIG. 16 (B) shows a principle view showing an upper forward field of view for the driver in FIG. 16 (A);
[0028] FIG. 17 (A) shows a perspective view showing upper ends of front posts arranged rearwardly of forward ends of fore and aft frames; and
[0029] FIG. 17 (B) shows a principle view showing an upper forward field of view for the driver in FIG. 17 (A).
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
[0030] While several embodiments will be described below, a combination of a feature in one embodiment with another in a different embodiment is understood to be within the scope of the present invention unless such combination leads to a contradiction.
[0031] An agricultural tractor will be described as an example of the maintenance vehicle. As shown in FIGS. 1 and 2 , the agricultural tractor has a cab 1 formed of vertical frames 2 of a structural framework B constituting a framework, boarding and alighting side doors 3 , rear side windows 4 and a rear window 5 having transparent glass planes covering portions surrounded by the vertical frames 2 , an annular upper frame 6 extending over upper surfaces of the vertical frames 2 , and a roof 7 placed on the upper frame 6 .
[0032] The cabin 1 defines a driving and control section 8 therein. The driving and control section 8 includes a steering wheel 11 attached to a steering column 10 disposed adjacent an engine hood 9 , and a driver's seat 12 disposed rearwardly of the steering column 10 . The rearward end of the seating portion of the driver's seat 12 means a rear end of the top surface where the driver sits. When the seat 12 has a seat pad portion and a separate seat back, the rearward end of the seating portion of the driver's seat 12 may mean the rearward end of the seat pad portion.
[0033] The roof 7 supports an air-conditioning unit A for air-conditioning the interior of the cab 1 .
First Embodiment
[0034] Different forms of attaching the air-conditioning unit A will be described hereinafter. A first embodiment will be described first, in which, as shown in FIGS. 2 and 3 , the air-conditioning unit A is mounted above a rear end of the annular upper frame 6 extending over the upper surfaces of the vertical frames 2 constituting the structural framework B. A rear frame portion 6 B located in a rear position of a hood portion 7 of the annular upper frame 6 is called a transverse frame herein.
[0035] The construction of the structural framework B for supporting the air-conditioning unit A will be described. As shown in FIG. 2 , right and left vertical frames 2 are erected at connecting bend portions between fore and aft frame portions 6 A and rear frame portion 6 B acting as the transverse frame of the annular upper frame 6 , to serve also as window frames of the rear side windows 4 . A support frame 6 C is laid to extend between the two vertical frames 2 and at a height level a step lower than the rear frame portion 6 B.
[0036] The air-conditioning unit A is placed in a state of being dropped on the upper surface of the support frame 6 C and between the neighboring vertical frames 2 supporting the support frame 6 C. The support frame 6 C is called herein an air-conditioning unit mounting portion.
[0037] As shown in FIG. 3 , a pair of right and left brackets 16 are attached in a fore and aft posture to the upper surface of the support frame 6 C. The air-conditioning unit A enclosed in a unit case 24 is placed on and fixed by bolts to the right and left brackets 16 .
[0038] The construction of the roof 7 will be described.
[0039] As shown in FIGS. 3 through 5 , the roof 7 includes an outer roof 13 and an inner roof 14 , each attached to and supported by the upper frame 6 . The inner roof 14 is an integral resin molding article, has a rearward half thereof above the driver's seat 12 formed as a low ceiling portion bulging downward. The air-conditioning unit A is mounted in this low ceiling portion.
[0040] As shown in FIGS. 2 and 3 , the outer roof 13 is laid on the upper surface of the upper frame 6 , and is in the form of a flat plate larger than the support surface. A seal ring 19 of rectangular section formed in the shape of a ring is attached to a downward-facing surface of the outer roof 13 . In the state of the outer roof 13 laid on the upper frame 6 , part of the section of the seal ring 19 contacts the upper surface of the upper frame 6 , to stop circulation of air to and from the exterior.
[0041] As shown in FIGS. 3 through 5 , ambient air intake openings 13 B are formed in downward surfaces of sideways eaves portions 13 E of the outer roof 13 projecting from opposite sides of the upper frame 6 . An ambient air feed opening 13 C communicating with the above ambient air intake openings 13 B is formed in a position inwardly of the seal ring 19 . Numeral 33 in the drawings denotes dust filters provided for the ambient air intake openings 13 B.
[0042] Air drawn in through the ambient air intake openings 13 B is guided forwardly of the vehicle body through a communicating path “b” acting as an ambient air feed duct formed in the double wall of the outer roof 13 , and is blown off from the ambient air feed opening 13 C formed forwardly of the communicating path “b” into a space “a” leading to the air-conditioning unit A described hereinafter.
[0043] The internal structure of the inner roof 14 will be described. As shown in FIGS. 1 through 4 , the air-conditioning unit A includes an evaporator 20 , and a heater 21 disposed forwardly thereof. The evaporator 20 cooperates with a compressor, an expansion valve and a condenser to constitute a coolant circulation circuit. The heater 21 is connected through piping to a radiator 22 mounted in the engine hood 9 .
[0044] A sirocco fan 23 is disposed at the right-hand side of the evaporator 20 for feeding the ambient air drawn in through the ambient air feed opening 13 C toward the evaporator 20 and heater 21 .
[0045] As shown in FIG. 3 , the ambient air introduced through the ambient air feed opening 13 C, is drawn and guided through the space “a” formed between the downward surface of the outer roof 13 and the inner roof 14 acting as a circulation path, to a guide bore 24 a of the sirocco fan 23 enclosed in the unit case 24 .
[0046] As shown in FIGS. 3 and 4 , the evaporator 20 and sirocco fan 23 are surrounded by the unit case 24 . A rear air-conditioning duct 15 A continuous with the unit case 24 extends transversely for guiding conditioning air from the air-conditioning unit A, from opposite lateral ends of the evaporator 20 to the right and left sides. Lateral air-conditioning ducts 15 B extend forward from opposite lateral ends of the rear air-conditioning duct 15 A for guiding the conditioning air forwardly of the vehicle body.
[0047] The right and left air-conditioning ducts 15 B and 15 B will be described. As shown in FIGS. 3 through 5 , each of the right and left air-conditioning ducts 15 B has inwardly directed blow-off openings 15 b, and the rearward blow-off opening 15 b is located for directing an appropriate amount of cool air near the driver's face. On the other hand, each lateral air-conditioning duct 15 B has blow-off openings 15 a arranged adjacent the forward thereof and directed forward and downward for blowing off the conditioning air toward a windshield 25 of the cab 1 , and a blow-off opening 15 d disposed rearwardly of the blow-off openings 15 a for blowing off defrost air toward the door glass.
[0048] As shown in FIGS. 2 and 3 , branch ducts 15 C extend rearward from the opposite ends of the rear air-conditioning duct 15 A, and blow-off openings 15 c are formed at extension ends thereof for blowing off the conditioning air to the rear side windows 4 and rear window 5 . The above lateral air-conditioning ducts 15 B and the like are located in the inner roof 14 , and are mounted in low ceiling portions formed at opposite sides of the inner roof 14 as shown in FIG. 5 .
[0049] As shown in FIG. 3 , the inner roof 14 includes a circulation opening 14 A disposed forwardly of the portion accommodating the air-conditioning unit A for drawing in air of the cab interior. A wall surface extends upward along the unit case 24 from an upper surface of a slope of a bottom inner roof 14 b defining the low ceiling portion, and the circulation opening 14 A is formed in a horizontal portion at the upper end of the vertical surface 14 c. The vertical surface 14 c of the top inner roof 14 a is called herein an interior air introducing duct.
[0050] On the other hand, the ambient air feed opening 13 C and circulation opening 14 A are vertically opposed to each other, and a switching valve 17 is disposed therebetween to act as a valve mechanism for opening and closing the ambient air feed opening 13 C and circulation opening 14 A. Thus, a switching is made between a state of drawing ambient air through the ambient air intake openings 13 B into the space “a” formed between the inner roof 14 and outer roof 13 , and a state of shutting off ambient air and circulating the air in the cab interior through the space “a”.
[0051] The valve mechanism may be the slide type rather than the pivoting type. Although not shown, the valve mechanism is operable by a switching lever erected to a level above and adjacent the driver's seat 12 .
[0052] As shown in FIG. 3 , the inner roof 14 , which has the circulation opening 14 A for drawing in air of the cab interior, includes a rear top inner roof portion 14 a defining the circulation opening 14 A, and a forward inner roof portion 14 b located in the forward part of the cab 1 . The inner roof 14 has a fore and aft intermediate position thereof in tight contact with the outer roof 13 . The intermediate position in tight contact separates the rear inner roof portion 14 a and forward inner roof portion 14 b. A CD radio cassette recorder 29 or the like is mounted in a space of the forward inner roof portion 14 b having the above construction. The back pressure of the interior air taken in from the circulation opening 14 A does not directly act on the CD radio cassette recorder 29 or the like, so that the CD radio cassette recorder 29 or the like has a reduced chance of drawing in dust and the like.
[0053] As shown in FIGS. 3 through 5 , the ambient air intake openings 13 B are arranged adjacent the air-conditioning unit A. Consequently, the communicating path b formed in the outer roof portion 13 and communicating with the ambient air intake openings 13 B may be shortened, and the sirocco fan 23 may have a reduced suction resistance.
[0054] A support cover 18 extends rearwardly of the support frame 6 C for covering the air-conditioning unit A. The rear window 5 is supported by the support frame 6 C and on the undersurface of the support cover 18 to be pivotable rearward about a transverse axis X. In a closed state, the rear window 5 does not protrude a large extent rearward, thereby to avoid interference with a linkage mechanism and the like supporting a tilling implement, though these components are not shown in the drawings.
Second Embodiment
[0055] Next, a second embodiment will be described, in which, as shown in FIG. 6 , the air-conditioning unit A is mounted forwardly of the rear end of the annular upper frame 6 .
[0056] As shown in FIGS. 6 and 7 , an outer roof 13 and an inner roof 14 are arranged to surround the air-conditioning unit A. An ambient air feed opening 13 C is formed in the outer roof 13 forwardly of the air-conditioning unit A, and an ambient air intake opening 13 B is formed in a downward surface of an eaves portion 13 A of the outer roof 13 projecting rearwardly for feeding ambient air to the ambient air feed opening 13 C. The inner roof 14 has a circulation opening 14 A opposed to the ambient air feed opening 13 C for drawing in air from the interior of the cab 1 . A switching valve 17 is disposed between the ambient air feed opening 13 C and circulation opening 14 A to act as a valve mechanism for opening and closing the ambient air feed opening 13 C and circulation opening 14 A. A switching may be made between a state of drawing ambient air through the ambient air intake opening 13 B into a space “a” formed between the inner roof 14 and outer roof 13 , and a state of shutting off ambient air and circulating the air in the cab interior through the space “a”.
[0057] Air taken into the space “a” is drawn into the sirocco fan 23 via a guide bore 24 a formed in the upper surface of the unit case 24 of the air-conditioning unit A. After being conditioned by the evaporator 20 and the like, the air is delivered to the air-conditioning ducts 15 A and 15 B.
[0058] As shown in FIG. 4 , the rear air-conditioning duct 15 A extends from opposite lateral ends of the evaporator 20 as described hereinbefore, and lateral air-conditioning ducts 15 B extend forward from opposite lateral ends of the rear air-conditioning duct 15 A for blowing off conditioning air into the cab as in the first embodiment.
[0059] Next, a mounting structure for the rear side windows 4 and rear window 5 will be described. FIG. 7 shows the air-conditioning unit A disposed forwardly of the rear end of the annular upper frame 6 . In order to employ the construction for arranging the air-conditioning unit A forwardly of the rear end of the annular upper frame 6 , the rear end of the annular upper frame 6 is displaced rearwardly of the position of the rear window 5 . For this reason, rear pillars acting as the vertical frames 2 located at boundaries between the rear window 5 and rear side windows 4 are connected to the upper frame 6 through connecting frames 30 to increase connecting strength of the frames. The rear window 5 is supported, to be pivotable rearward to an open position, by pivot arms 32 pivotally connected to brackets 31 attached to the rear frame portion 6 B of the upper frame 6 .
Third Embodiment
[0060] Next, a third embodiment will be described, in which, as shown in FIG. 8 , the air-conditioning unit A is mounted below a suspending frame portion 6 D formed on the rear frame portion 6 B acting as the transverse frame.
[0061] The construction of the structural framework B for supporting the air-conditioning unit A will be described. As shown in FIGS. 8 and 9 , right and left vertical frames 2 are erected at connecting bend portions between fore and aft frame portions 6 A and rear frame portion 6 B of the annular upper frame 6 , to serve also as window frames of the rear side windows 4 . The suspending frame portion 6 D is laid to extend between the two vertical frames 2 and at a height level a step higher than the rear frame portion 6 B.
[0062] The air-conditioning unit A is suspended in a state of being slipped under the lower surface of the suspending frame portion 6 D and between the neighboring vertical frames 2 supporting the suspending frame portion 6 D. The suspending frame portion 6 D is called herein an air-conditioning unit mounting portion.
[0063] As shown in FIG. 9 , a pair of right and left brackets 27 are attached in a fore and aft posture to the lower surface of the suspending frame portion 6 D. The air-conditioning unit A enclosed in a unit case 24 is fixed by bolts to the right and left brackets 27 .
[0064] As shown in FIG. 9 , an outer roof 13 and an inner roof 14 are arranged to surround the air-conditioning unit A. An ambient air feed opening 13 C is formed in the outer roof 13 forwardly of the air-conditioning unit A, and ambient air intake openings (not shown) are formed in eaves portions (not shown) of the outer roof 13 projecting laterally of the vehicle body for feeding ambient air to the ambient air feed opening 13 C. The inner roof 14 has a circulation opening 14 A opposed to the ambient air feed opening 13 C for drawing in air from the interior of the cab 1 . A switching valve 17 is disposed between the ambient air feed opening 13 C and circulation opening 14 A to act as a valve mechanism for opening and closing the ambient air feed opening 13 C and circulation opening 14 A. A switching may be made between a state of drawing ambient air through the ambient air intake opening 13 B into a space “a” formed between the inner roof 14 and outer roof 13 , and a state of shutting off ambient air and circulating the air in the cab interior through the space “a”.
[0065] Air taken into the space “a” is drawn into the sirocco fan 23 via a guide bore (not shown) formed in the upper surface of the unit case 24 of the air-conditioning unit A. After being conditioned by the evaporator 20 and the like, the air is delivered to the air-conditioning ducts 15 A and 15 B.
[0066] As shown in FIG. 4 , the rear air-conditioning duct 15 A extends from opposite lateral ends of the evaporator 20 as described hereinbefore, and lateral air-conditioning ducts 15 B extend forward from opposite lateral ends of the rear air-conditioning duct 15 A for blowing off conditioning air into the cab as in the second embodiment.
[0067] As shown in FIG. 9 , the rear window 5 is supported by the undersurface of a portion of the inner roof 14 projecting rearwardly of the vertical frames 2 . The rear window 5 does not protrude a large extent rearward, thereby to avoid interference with a linkage mechanism and the like supporting a tilling implement, though these components are not shown in the drawings.
Fourth Embodiment
[0068] Next, a fourth embodiment will be described, in which, as shown in FIG. 10 , the air-conditioning unit A is mounted further rearwardly of the rear frame portion 6 B acting as the transverse frame.
[0069] The construction of the structural framework B for supporting the air-conditioning unit A will be described. As shown in FIGS. 10 and 11 , right and left vertical frames 2 are erected at connecting bend portions between fore and aft frame portions 6 A and rear frame portion 6 B of the annular upper frame 6 , to serve also as window frames of the rear side windows 4 .
[0070] As shown in FIG. 11 , a pair of right and left brackets 27 are attached in a fore and aft posture to the lower surface of the rear frame portion 6 B. The air-conditioning unit A enclosed in the unit case 24 is fixed by bolts to the right and left brackets 27 .
[0071] As shown in FIG. 11 , a rear cover 28 is attached to the rear frame portion 6 B to surround the air-conditioning unit A attached to the rear frame portion 6 B. The outer roof 13 is supported by the rear frame portion 6 B, and the inner roof 14 is supported by the rear cover 28 .
[0072] An ambient air feed opening 13 C is formed in the outer roof 13 , and ambient air intake openings (not shown) are formed in eaves portions (not shown) of the outer roof 13 projecting laterally of the vehicle body for feeding ambient air to the ambient air feed opening 13 C. The inner roof 14 has a circulation opening 14 A opposed to the ambient air feed opening 13 C for drawing in air from the interior of the cab 1 . A switching valve 17 is disposed between the ambient air feed opening 13 C and circulation opening 14 A to act as a valve mechanism for opening and closing the ambient air feed opening 13 C and circulation opening 14 A. The switching valve 17 switches between a state of drawing ambient air introduced through the ambient air intake opening 13 B, via a space between the inner roof 14 and outer roof 28 , into an inner space “a” of the rear cover 28 , and a state of shutting off ambient air and circulating the air in the cab interior through the inner space “a”. Reference “b” in the drawing denotes an ambient intake guide, and 14 c denotes an interior air intake guide.
[0073] Air taken into the space “a” is drawn into the sirocco fan 23 via a guide bore 24 a formed in the upper surface of the unit case 24 of the air-conditioning unit A. After being conditioned by the evaporator 20 and the like, the air is delivered to the air-conditioning ducts 15 A and 15 B.
[0074] As shown in FIG. 4 , the rear air-conditioning duct 15 A is disposed forwardly of the evaporator 20 , and lateral air-conditioning ducts 15 B extend forward from opposite lateral ends of the rear air-conditioning duct 15 A for blowing off conditioning air into the cab as in the first to third embodiments.
[0075] The rear window 5 is supported by an undersurface of a connection between the inner roof 14 and rear cover 28 . The rear window 5 does not protrude a large extent rearward, thereby to avoid interference with a linkage mechanism and the like supporting a tilling implement, though these components are not shown in the drawings.
Other Embodiments
[0076] The following modified constructions should be understood as applicable to the first to fourth embodiments described hereinbefore.
[0077] (1) A modified construction of the air-conditioning duct 15 will be described. A construction in which ducts 15 are arranged in the cab 1 and in a transversely middle position of the roof 7 will be described here. As shown in FIG. 12 , an evaporator 20 and a sirocco fan 23 are surrounded by a unit case 24 . A rear air-conditioning duct 15 A continuous with the unit case 24 extends transversely for guiding conditioned air from the air-conditioning unit A, from opposite lateral ends of the evaporator 20 to the right and left sides. A central air-conditioning duct 15 E acting as a main air-conditioning duct extends forward from a transversely middle portion of the rear air-conditioning duct 15 A for guiding the conditioned air forwardly of the vehicle body.
[0078] As shown in FIG. 12 , the central air-conditioning duct 15 E include right and left intermediate branch air-conditioning ducts 15 F acting as branch air-conditioning ducts extending right and left from intermediate positions in the fore and aft direction, and front air-conditioning ducts 15 G extending to full extents right and left from positions forwardly of the intermediate branch air-conditioning ducts 15 F. Each of the right and left intermediate branch air-conditioning ducts 15 F has blow-off openings 15 f formed therein. The blow-off openings 15 f are located to blow off an appropriate quantity of cool air to near the driver's face. On the other hand, the front air-conditioning ducts 15 G have front blow-off openings 15 a formed therein for blowing off conditioning air forward and downward toward the windshield 25 of the cab 1 , and blow-off openings 15 d formed rearwardly of the front blow-off openings 15 a for blowing off defrost air toward the door glass panes.
[0079] As shown in FIG. 12 , branch ducts 15 C extend rearward from opposite lateral ends of the rear air-conditioning duct 15 A, and have blow-off openings 15 c formed therein for blowing conditioning air to the rear side windows 4 and rear window 5 .
[0080] (2) A different modified construction of the air-conditioning duct 15 will be described. In this construction, the duct 15 is arranged in the cab 1 to cover the entire surface of the roof 7 . As shown in FIGS. 13 and 14 , an evaporator 20 and a sirocco fan 23 are surrounded by a unit case 24 . A full surface air-conditioning duct 15 H continuous with the unit case 24 extends forward from opposite lateral ends of the evaporator 20 for guiding conditioned air forward from the air-conditioning unit A.
[0081] As shown in FIG. 13 , the full surface air-conditioning duct 15 H has blow-off openings 15 f formed in intermediate positions in the fore and aft direction. The blow-off openings 15 f are located to blow off an appropriate quantity of cool air rearward to near the driver's face. On the other hand, blow-off openings 15 a are formed in the cab 1 for blowing off conditioning air forward and downward toward the windshield 25 of the cab 1 . Blow-off openings 15 d are formed rearwardly of the front blow-off openings 15 a for blowing off defrost air toward the door glass panes.
[0082] As shown in FIG. 13 , the full surface air-conditioning duct 15 H has blow-off openings 15 b formed therein for blowing conditioning air to the rear side windows 4 and rear window 5 . The air-conditioning duct 15 covering substantially the entire surface as described above has an advantage of allowing the blow-off openings to be formed in desired positions.
[0083] As a structure for introduces external air into the full surface duct 15 H having such construction, as shown in FIGS. 13 and 14 , ambient air feed openings 13 B are formed in eaves portion 13 E of the outer roof 13 projecting laterally of the vehicle body.
[0084] (3) Although not shown, bellows-like connectors may be provided in the connections between the right and left air-conditioning ducts 15 B and 15 B and rear air-conditioning duct 15 A. Then, the connecting state is stabilized by the elasticity of the duct itself and by absorbing manufacturing errors, for example.
[0085] (4) As shown in FIG. 13 , a hose 26 extends from the unit case 24 to discharge dew water from the evaporator 20 . The hose 26 extends out of the vehicle body through the interior of the vertical frame 2 present adjacent the unit case 24 .
[0086] (5) A mode of using the upper frame 6 as air-conditioning ducts 15 will be described next. As shown in FIG. 15 , an ambient air intake opening (not shown) is formed in a rearward eaves portion (not shown) of the outer roof 13 . Air is taken in from a communicating path “b” of the outer roof 13 into a space “a” formed with the inner roof 14 , and introduced through a guide bore 24 a into the air-conditioning unit A. As shown in FIG. 15 , ambient air and interior air introduced are sent out of an exit 24 A of the unit case 24 after being adjusted by the air-conditioning unit A. The exit 24 A communicates with the interior space of the upper frame 6 , so that the fore and aft frame portions 6 A of the upper frame 6 serve as the air-conditioning ducts 15 .
[0087] Thus, as shown in FIG. 15 , air blow-off openings 6 a of conditioned air are formed in inner surfaces of the fore and aft frame portions 6 A. Since the upper frame 6 is used also as air-conditioning ducts, there is no need to provide air-conditioning ducts separately.
[0088] The mode of supporting the air-conditioning unit A is the same as in the first embodiment.
[0089] (6) The following framework construction may be adopted for the cab 1 . As shown in FIG. 16 (A), (B), right and left front struts 2 , supporting the windshield 25 , of the structural framework B project above the right and left, fore and aft frame portions 6 A of the upper frame 6 , and an upper front frame portion 6 E extending transversely and connecting upper ends of the front struts 2 is installed above the right and left, fore and aft frame portions 6 A. Since these components are located above the right and left, fore and aft frame portions 6 A, the windshield 25 may be located in a correspondingly elevated position, to provide an excellent, enlarged field of view for the driver.
[0090] As shown in FIG. 17 (A), (B), right and left front struts 2 are curved so that upper end regions 2 A are located further rearward than lower regions of the front struts 2 . An upper front frame portion 6 E is placed to extend between the upper ends of the front struts 2 . The upper front frame portion 6 E and the right and left, fore and aft frame portions 6 A are set to the same height.
[0091] With this construction, the upper front frame portion 6 E can be located further rearward than the lower regions of the front struts 2 . The driver can look up with an enlarged field of view, to be able to see an increased height.
[0092] (7) The outer roof 13 may have eaves portions projecting laterally or fore and aft from the upper frame 6 , to prevent direct rays entering the cab having large glass surfaces.
[0093] (8) The foregoing embodiments have been described as applying this invention to the agricultural tractor. The invention may be applied to other agricultural machines such as a combine or to construction equipment.
[0094] (9) A lateral air-conditioning duct 15 B may be provided for only one of the right and left sides.
[0095] (10) The ambient air intake opening 13 B may be provided only to one of the eaves portions 13 E. Especially when it is provided on the left side (i.e. the side the operator often gets in and out of the cabin) of the roof ( 7 ), the filter in the ambient air intake opening 13 B may more easily be accessed for checking and maintenance. Also, since the fan 23 is located on the right hand area of the roof 7 , the air flow speed can be increased due to funneling effect since the opening 13 B is located at a distance from the fan 23 , leading to an increased efficiency of the fan 23 .
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A cabin for a work vehicle comprises: a driver's seat positioned within the cabin; cabin frames including at least a transverse frame located in a rear region of the cabin; a roof supported by at least some of the cabin frames; at least one air-conditioning duct located within the roof; an air-conditioning unit located rearwardly with respect to a rearward end of a seat portion of the driver's seat and adjacent the transverse frame for conditioning air and for feeding air-conditioned air into the at least one air-conditioning duct.
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FIELD OF THE INVENTION
The present invention relates to a novel oligonucleotide primer for phosphoridyl inositol in Bacillus cereus . The present invention also relates to to a method for the detection of Bacillus cereus in food.
BACKGROUND OF THE INVENTION
Among the predominantly occurring food borne pathogenic bacteria, Bacillus cereus , an opportunistic pathogen has been found to occur abundantly in Indian foods and also cause illnesses like diarrhoea and/or emesis (Rakh et al. 1988). The illness has been attributed to the presence of enterotoxins and other toxins including haemolysins claborated by strains of B. cereus . Conventionally, B. cereus is detected by its ability to grow on selective plating media containing egg yolk and inability to utilize mannitol. The isolates are further identified by morphological, cultural and biochemical characteristics. (Duguid, 1996).
Advances made in detection methods have led to the use of polymerase chain reaction (PCR) for the specific detection of B. cereus . PCR protocols have been developed for the detection of B. cereus group of bacteria in pure culture systems and food samples using specific sets of primers.
Reference is made to the work of Schrafts and Griffiths (1995), wherein primers for the cereolysin AB gene (M 24149) of B. cereus was designed. The detection limit for B. cereus by PCR in artificially contaminated milk samples was 103 CFU/ml without enrichment of the milk.
Reference is made to the works of Agata et. al. (1995) and Mantynen and Lindstrom (1998), wherein primers for the BceT gene was designed and used to study the distribution of the toxin gene in clinical and food isolates of B. cereus . Only qualitative observations were made on this work and no quantification has been reported. It was also postulated that the BceT gene could not be targeted to assess the enterotoxic potential of B. cereus strains.
Reference is made to the work of Wang et al. (1997), wherein a universal protocol for PCR detection of a number of food borne pathogenic bacteria was devised using haemolysin as the target gene. Detection of toxin producing strains of B. cereus was accomplished using these primers, following overnight enrichment of various food samples in a laboratory growth medium. This work provides only qualitative information and quantification was not addressed.
Reference is made to the work of Hsieh et al. (1999), wherein oligonucleotide primers were designed for sphingomyelinase gene and used for the PCR based detection of strains of B. cereus group in food samples. These primers can detect 100 cells/gram of the food sample only after an enrichment step for 8 hours indicating poor sensitivity
Reference is made to the work of Yamada et al (1999) disclosing spiked boiled rice sample with varying cell concentrations of B. cereus . The rice sample was enriched in nutrient broth for different time intervals. No amplification was observed with non-enriched food samples with a gyrase D specific primers, even when the initial cell number was 10 4 CFU of B. cereus per gram of boiled rice. Detection of low numbers of B. cereus by PCR was possible only after 15 hours enrichment in nutrient broth.
Reference is made to the work of Tsen et al. (2000), wherein primers were designed for 16s ribosomal RNA (Ribo Nucleic Acid) and used for PCR-based quantification of B. cereus spiked in food samples. Target cells ranging from 1 to 9 CFU/g of food sample could be detected only after 8 hours enrichment in brain heart infusion broth supplemented with glucose.
In German Patents DE 19915141 and DE 1991514 the sequences refer to 16s ribosomal RNA (Ribo Nucleic Acid) and gyrase B specific primers used for the detection of Bacillus cereus.
Reference is made to the work of Schrafts and Griffiths (1995) and Herman et al (1995), wherein a method for the isolation of target DNA from milk samples was devised. This method was elaborate comprising multitude of steps using combination of enzymes, detergents and column chromatography. The method also suffered from lack of sensitivity and could only detect 10 3 CFU/ml. B. cereus by PCR using primers for cereolysin AB gene,
Reference is made to the work of Yamada et al. (1999), wherein a protocol for the detection of B. cereus from boiled rice was described. The method included pre-enrichment step, two steps of filtration, followed by boiling of the samples prior to use in PCR. It was reported that at zero hour, a moderately high count of 2.4×10 4 CFU of B. cereus per gram of boiled rice failed to yield any PCR amplified product. Low numbers of B. cereus could only be detected after 15 hours of enrichment
The drawback of all these methods have been non-specific detection of target organism i.e. B. cereus , lack of reproducibility, failure to detect all the isolates of B. cereus in a food system and lack of sensitiveness to detect low numbers of target organism. Besides, the methods are cumbersome and procedures are lengthy. The problem of formation of spores by B. cereus group of organisms makes detection by PCR a difficult proposition. In most of the methods a step of enrichment in a suitable laboratory growth medium is included which may take 8 to 15 hours of incubation for building up of cell numbers which can result in target DNA for use in PCR detection.
OBJECTS OF THE INVENTION
The main object of the present invention is to provide an improved method for the detection of Bacillus cereus in foods which obviates the drawbacks detailed above.
Another object of the present invention is to use a primer designed for a conserved region of a specific gene in the target organism.
Still another object of the present invention is to use the designed primer in detecting isolates which belong to B. cereus group.
Yet another object of the present invention is to detect B. cereus in food systems directly by PCR.
Still another object of the present invention is to use a simple and effective method for the preparation of template DNA (Deoxyribo Nucleic Acid) of the organism directly from the foods.
Yet another object of the present invention is to use PCR conditions specific for the detection of target gene in the organism.
Still another object of the present invention is to detect very low numbers of target organism in the food systems.
SUMMARY OF THE INVENTION
Accordingly, the present invention provides a novel oligonucleotide primer for phosphotidyl inositol in B. cereus said printer comprising
PI-1 (F) 5′ AGTATGGGGAATGAG 3′
(SEQ ID NO: 1)
PI-1 (F) 5′ ACAATTTTCCCACGA 3′
(SEQ ID NO: 2)
The present invention also refers to method for the detection of B. cereus in foods said method comprising using primers specific for phosphotidyl inositol gene in B. cereus in a mixed microflora, said primers comprising
PI-1 (F) 5′ AGTATGGGGAATGAG 3′
(SEQ ID NO: 1)
PI-1 (F) 5′ ACAATTTTCCCACGA 3′
(SEQ ID NO: 2)
In one embodiment of the invention, the food matrices for detecting B. cereus in milk and cooked rice.
In another embodiment of the invention, template DNA from B. cereus in cooked rice is extracted using Triton X-100, 0.5-2%, boiling at 96-100° C. for 3-8 min and treatment with phenol : chloroform in the ratio of 22:21-28.27.
In another embodiment of the invention, the template DNA from B. cereus in milk is extracted using diethyl ether:chloroform in the ratio of 1:1-1:3, urea 1.5 3.5 M and sodium dodecyl sulphate in a range of 0.5-2%.
In a further embodiment of the invention, the PCR reaction mixture in a total volume of 25 μl comprises of Tris HCl: 8-12 mM; KCl 45-55 mM, MgCl 2 : 0.5-3.0 mM; gelatin: 0.005 0.02%; individual deoxynucleoside triphosphates: 150-300 μM; each specific primer: 30 60 picomoles; Taq DNA polymerase: 0.5-2.0) units and template DNA: 1-3 μl.
In another embodiment of the invention, detection of B. cereus is effected by amplification profile of target gene from an initial denaturation at 90-98° C. for 2-8 min, amplification cycles of 28-40, each cycle with a denaturation at 90-98° C. for 40-70 seconds, annealing at 46-54° C. for 40-80 seconds and an extension at 68-76° C. for 45-75 seconds and final extension at 68-76° C. for 4-12 min
In another embodiment of the invention, analysis of the PCR product is done in 1.2-1.8% agarose gel electrophoresis, visualization of the PCR product by staining with 0.5 (g/ml ethidium bromide and observation in a UV transilluminator.
In yet another embodiment of the invention, detection of minimum number of cells of B. cereus is done in a food matrix by PCR.
DETAILED DESCRIPTION OF THE INVENTION
The present invention relates to an improved PCR method for the detection of B. cereus in foods. The PCR method using the primers of the invention detects 1 to 106 cells of B. cereus directly in foods. Polymerase chain reaction method is used to selectively amplify phosphotidyl inositol gene in B. cereus . Milk and cooked rice samples were spiked with varying cell numbers of B. cereus ranging from 1 to 1,000,000. Protocols for extraction of template DNA from B. cereus present in food matrix were standardized using detergents and organic solvents. The PCR reaction mixture and amplification conditions were optimized for the specific amplification. Visualization of PCR products revealed that by the method followed, it is possible to detect cell numbers ranging from 1 to 1,000,000 in milk and cooked rice samples.
The primers of the invention directly detect Bacillus cereus in food systems by PCR. This method can detect all the strains of B. cereus . The method is rapid and sensitive making it possible to detect even 1 cell in a food matrix overcoming any steps of enrichment.
The following examples are given by way of illustrations of the present invention and therefore should not be construed to limit the scope if the present invention.
EXAMPLE-1
Oligonucleotide primers for phosphotidyl inositol gene of B. cereus were designated based on the gene sequence (M 30809) using the software programme Primer 3.0. This primer set amplifies a 342 base pair (bp) fragment of the gene, the sequence of which is given below. Sterilization of media and other solutions was achieved by autoclaving for 20 mm at 121° C.
PI-1 (F) 5′ AGTATGGGGAATGAG 3′
(SEQ ID NO: 1)
PI-1 (F) 5′ ACAATTTTCCCACGA 3′
(SEQ ID NO: 2)
Aliquots in 100 μl of a native food isolate of B. cereus was inoculated into sterile 10 ml brain heart infusion (BHI) broth and incubated for 18 h at 37° C. in a shaker incubator with 140 rpm. Cells were harvested by centrifugation at 10,000 rpm for 10 min at 4° C. The cells were suspended in 10 ml sterile 0.85% saline to get a cell concentration of 10 9 colony forming units per milliliter (CFU/ml). From this stock, serial dilutions in 9 ml sterile 0.85% saline were carried out to achieve cell concentrations ranging from 10 8 to 10 1 CFU/ml. The individual dilutions were used for spiking into milk samples.
Twenty milliliters of pasteurized milk was taken in a sterile screw capped tube of 25×125 mm dimension, steamed for 30 min in a cooker without any pressure and cooled to 30° C. In individual 1.5 ml sterile microcentrifuge tube, 0.4 ml of the cooled milk sample was mixed with 0.4 ml of 0.85% sale suspension of B. cereus to attain a final cell concentration ranging from of 10 6 , 10 5 , 10 4 , 10 3 , 10 2 , 10 1 and 10 0 CFU/ml. To each tube was added 0.25 ml each of diethyl ether and chloroform were added to the samples and vortexed for 30 seconds. The samples were centrifuged at 10,000 rpm for 15 min at 25° C. The aqueous phase was transferred to a fresh 1.5 ml sterile microcentrifuge tube and 0.5 ml of 6M urea and 0.1 ml of 10% sodium dodecyl sulphate were added. The samples were incubated at 37° C. for 20 min and then centrifuged 10,000 rpm for 15 min at 25° C. The supernatant was discarded and 0.1 ml of 0.2N NaOH was added to the samples and incubated at 37° C. for 10 min. DNA was precipitated by adding 1.0 ml of chilled absolute ethanol and 0.1 ml of 3M sodium aectate (pH 4.8) and holding the samples at −20° C. for 2 h. Samples were centrifuged at 10,000 rpm for 15 min at 4° C. The supernatant was discarded and excess salt in the DNA preparation was removed by adding 1.0 ml of chilled 70% ethanol and centrifuging the samples at 10,000 rpm for 15 min at 4° C. The supernatant was discarded and the DNA pellet was air-dried and resuspended in 15 (1 of sterile ultrafiltered water.
Amplification was performed in a total reaction volume of 25 μl which contained 2 μl of the DNA preparation from milk samples. The reaction mixture consisted of 1× PCR buffer (10 mM Tris HCl, pH 9.0, 50 mM KCl, 1.5 mM MgCl 2 , 0.01% gelatin), 200 μM of each deoxynucleoside triphosphate, 50 picomoles of each primer and 1.0 unit of Taq DNA polymerase Template DNAs were initially denatured at 94° C. for 5 min. Subsequently, a total of 35 amplification cycles were carried out in a programmable thermocycler. Each cycle consisted of denaturation for 1 min at 94° C., primer annealing for 1 min at 50° C. and extension for 1 min at 72° C. The last cycle was followed by a final exension at 72° C. for 8 min.
PCR products were analysed by agarose gel electrophoresis. Aliquots of 10 μl PCR products were mixed with 2.0 μl of loading dye and loaded onto 1.5% agarose gel and subjected to electrophoresis for 2 h at 120 volts in 1× TAE buffer. Gel was stained with ethidium bromide (0.5 μg/ml), de-stained with distilled water and examined on a UV transilluminator. A 100 bp ladder was used as molecular size marker. The amplification profile in the gel was documented in a CCD-camera based Gel Documentation System.
The specific amplicons of 342 bp for phosphotidyl inositol were observed when PCR was performed with milk samples containing B. cereus cells ranging from 1 to 1,000,000.
EXAMPLE-II
Oligonucleotide primers for phosphotidyl inositol gene of B. cereus were designated based on the gene sequence (M 30809) using the software programme Primer 3.0. This primer set amplifies a 342 base pair (bp) fragment of the gene, the sequence of which is given below. Sterilization of media and other solutions was achieved by autoclaving for 20 mm at 121° C.
PI-1 (F) 5′ AGTATGGGGAATGAG 3′
(SEQ ID NO: 1)
PI-1 (F) 5′ ACAATTTTCCCACGA 3′
(SEQ ID NO: 2)
Aliquots in 100 μl of a native food isolate of B. cereus was inoculated into sterile 10 ml brain heart infusion (BHI) broth and incubated for 18 h at 37° C. in a shaker incubator with 140 rpm. Cells were harvested by centrifugation at 10,000 rpm for 10 min at 4° C. The cells were suspended in 10 ml sterile 0.85% saline to get a cell concentration of 10 9 colony forming units per milliliter (CFU/ml). From this stock, serial dilutions in 9 ml sterile 0.85% saline were carried out to achieve cell concentrations ranging from 10 8 to 10 3 CFU/ml. The individual dilutions were used for spiking into cooked rice samples.
Raw rice in 1000 g quantity was taken, cleaned and washed with running tap water. Cleaned rice was mixed with water in 1:2 proportion, taken in a stainless steel container and steam cooked in a pressure cooker for 20 min. Cooked rice in 100 g aliquots were taken in individual sterile 500 ml glass beakers and was spiked with 1.0 ml saline suspension of B. cereus to get a cell concentration of 10 7 CFU/g and mixed uniformly.
Spiked cooked rice samples in 11 g aliquots was then added to 99 ml sterile 0.85% saline taken in a 250 ml conical flask, mixed well and serial dilutions were prepared in sterile 0.85% saline to get individual cell concentrations of 10 6 , 10 5 , 10 4 , 10 3 , 10 2 , 10 1 and 10 0 CFU/g. Aliquots of 1 ml of diluted samples were transferred to a 1.5 ml sterile microcentrifuge tubes. The samples were centrifuged at 10,000 rpm for 5 min at 4° C. The pellet was washed thrice with 1.0 ml phospate buffered saline of pH 7.4 and once with 1.0 ml sterile ultrafilter water by centrifugation at 10,000 rpm for 5 min at 4° C. and discarding the washes. The pellet was resuspended in a mixture containing 50 μl sterile ultrafilter water and 450 μl sterile 1% Triton X-100. The samples were incubated in boiling water for 5 min 0.5 ml phenol:chloroform (25:24) was added to the sample, vortexed briefly and centrifuged at 10,000 rpm for 15 min at 4° C. The aqueous phase was transferred to a fresh 1.5 ml sterile microcentrifuge tube and 0.5 ml chloroform was added to the sample. The samples were centrifuged at 10,000 rpm for 15 min at 4° C. and the aqueous phase was transferred to a fresh 1.5 ml sterile microcentrifuge tube. DNA was precipitated by adding 1.0 ml chilled absolute ethanol and 0.1 ml of 3M sodium acetate (pH 4.8) and incubating the samples at −20° C. for 2 h. The samples were centrifuged at 10,000 rpm for 15 min at 4° C. Excess salt in the DNA pellet was removed by adding 1.0 ml chilled 70% ethanol and centrifuging the samples at 10,000 rpm for 15 min at 4° C. The supernatant was discarded. The DNA pellet was air dried and dissolved in 15 μl of sterile ultrafilter water.
Amplification was performed in a total reaction volume of 25 μl containing 2 μl of the DNA preparation from milk samples. The reaction mixture consisted of 1× PCR buffer (10 mM Tris HCl, pH 9.0, 50 mM KCl, 1.5 mM MgCl 2 , 0.01% gelatin), 200 μM of each deoxynucleoside triphosphate, 50 picomoles of each primer and 1.0 unit of Taq DNA polymerase. Template DNAs were initially denatured at 94° C. for 5 min. Subsequently, a total of 35 amplification cycles were carried out in a programmable thermocycler. Each cycle consisted of denaturation for 1 min at 94° C., primer annealing for 1 min at 50° C. and extension for 1 min at 72° C. The last cycle was followed by a final extension at 72° C. for 8 min.
PCR products were analysed by agarose gel electrophoresis. Aliquots of 10 μl PCR products were mixed with 2.0 μl of loading dye and loaded onto 1.5% agarose gel and subjected to electrophoresis for 2 h at 120 volts in 1× TAE buffer. Gel was stained with ethidium bromide (0.5 (g/ml), destained with distilled water and examined on a UV transilluminator. A 100 bp ladder was used as molecular size marker. The amplification profile in the gel was documented in a CCD-camera based Gel Documentation System.
The specific amplicons of 342 bp for phosphotidyl inositol were observed when PCR was performed with cooled rice samples containing B. cereus cells ranging from 1 to 1,000,000.
The main advantages of the present invention are:
1. The designed phosphotidyl inositol primers is specific for the detection of B. cereus.
2. In a mixed microflora, the designed primer set specifically detects B. cereus with no cross reactivity.
3. A simple and effective protocol for extraction of template DNA for B. cereus present in a varied food matrix.
4. Standardized PCR conditions for the detection of B. cereus present in milk and cooked rice.
5. A rapid and sensitive PCR method which can detect even 1 cell of B. cereus in food system.
2
1
15
DNA
Bacillus cereus
1
agtatgggga atgag 15
2
15
DNA
Bacillus cereus
2
acaattttcc cacga 15
|
The present invention provides novel oligonucleotide primers for phosphotidyl inositol in B. cereus the primer comprising
PI-1 (F) 5′ AGTATGGGGAATGAG 3′
PI-1 (F) 5′ ACAATTTTCCCACGA 3′
and to a method for the detection of B. cereus in foods in a mixed microflora.
| 2
|
RELATED APPLICATION
[0001] This application claims the benefit of U.S. Provisional Application No. 60/417,683, filed on Oct. 10, 2002. The entire teachings of the above application are incorporated herein by reference.
BACKGROUND OF THE INVENTION
[0002] Chromated copper arsenate (CCA) is a pesticide commonly used in pressure-treated wood. CCA protects wood from deterioration, and CCA-treated wood is often found in outdoor wooden structures such as decks and children's play equipment. According to the Connecticut Department of Public Health, recent studies have shown that rainwater leaches CCA from pressure-treated wood that is not sealed, leading to potential contamination of the soil underneath the wood. Also, a significant residue of CCA can be left on the surface of pressure-treated wood. This residue can easily be removed from the wood surface and transferred onto objects contacting the wood surface, such as skin, hair and clothing.
[0003] The most toxic part of the CCA pesticide is the heavy metal arsenic. Arsenic is a known carcinogen, which can also be toxic to the skin and internal organs with long term exposure. There are concerns that regular contact with arsenic leached from pressure-treated wood can lead to an increased risk for cancer or other long-term health effects. It has been shown that exposure to CCA-treated wood can be the major source of arsenic for children who frequently play on structures made of CCA-treated wood.
[0004] Lead-containing paints also represent a significant public health concern. Soil adjacent to houses painted with exterior lead based paint can contain lead levels as high as 10,000 ppm. Once soil has become contaminated with lead, it remains a long term source of lead exposure. Similarly, interior lead based paint contributes to increased lead levels inside a home. Lead can be mobilized from a painted surface by a number of mechanisms including natural weathering processes, such as exposure to rain or other water and abrasion of the surface.
[0005] Lead that is ingested or absorbed by an organism is recognized as a neurotoxin, and children are particularly susceptible to its effects. As such, lead poisoning is one of the most common pediatric health problems in the United States. The Center for Disease Control defines childhood lead poisoning as occurring when blood lead levels are greater than 10 micrograms per deciliter based on evidence showing decreased intelligence and slower neurological development in children.
[0006] Thus, a method is needed to reduce or prevent the mobilization of heavy metals into the environment from sources such as CCA-treated wood and surfaces painted with lead based paint. Alternatively, a method is needed to reduce the bioavailability of heavy metals if they are liberated into the environment.
SUMMARY OF THE INVENTION
[0007] It has now been found that several sources of phosphate, chloride, sulfate, iron ions, bases (e.g., lime and magnesium oxide) and/or silicate can be used to reduce the surface solubility of lead and arsenic, when the surfaces are not substantially damaged or destroyed (e.g., through demolition or other waste-generating processes). When intact wood, steel or concrete surfaces painted with a lead-based paint were treated with a solution containing phosphate, iron and chloride bearing phosphate, or silicate, the amount of lead leaching from the surface into distilled water over 24 hours was reduced to an undetectable level (Example 1). Similarly, when CCA-treated wood was treated with a solution containing iron chloride or iron sulfate and subjected to the same leaching procedure, arsenic was reduced to non-detectable in the leachate (Example 1). Solutions containing iron(III) chloride or iron(III) sulfate with wet process amber phosphoric acid also reduced the amount of arsenic detected in the leachate of CCA-treated wood, while a slurry of iron(III) chloride and calcium oxide (lime) resulted in an undetectable amount of arsenic in the leachate (Example 1).
[0008] The present invention includes a method of reducing solubility of a heavy metal in wood containing a heavy metal, particularly pressure treated wood, to reduce leaching of the heavy metal from the wood when the wood is exposed to natural or induced leaching conditions, comprising applying a stabilizing agent comprising phosphate, silicate, chloride, sulfate, a base (e.g., lime), a source of iron ions or a combination thereof onto the wood to produce a treated wood, where the stabilizing agent binds to the heavy metal to form a heavy metal complex when exposed to natural or induced leaching conditions. Preferably, the wood contains arsenic (e.g., from treatment with chromated copper arsenate). Wood treated by this method is left intact, such that it is not demolished or otherwise generated into a waste for more than one month, more than six months, more than one year, more than two years, more than five years or more than ten years after treatment with the stabilizing agent.
[0009] In another embodiment, the present invention is a method of reducing solubility of a heavy metal in wood containing a heavy metal to reduce bioavailability of the heavy metal from the wood when the wood is contacted directly by an organism or a substance that directly or indirectly contacts an organism, comprising applying a stabilizing agent that contains phosphate, silicate, chloride, sulfate, a base, a source of iron ions or a combination thereof onto the wood to produce a treated wood, where the stabilizing agent binds to the heavy metal to form a heavy metal complex. Wood treated by this method is left intact, such that it is not demolished or otherwise generated into a waste for more than one month, more than six months, more than one year, more than two years, more than five years or more than ten years after treatment with the stabilizing agent.
[0010] The present invention also includes a wooden object containing a heavy metal, where the wooden object is coated with a stabilizing agent comprising phosphate, silicate, chloride, sulfate, a base, a source of iron ions or a combination thereof to produce a treated wooden object, where the stabilizing agent binds to the heavy metal to form a heavy metal complex when exposed to natural or induced leaching conditions, which reduces leaching of the heavy metal from the wooden object when the wooden object is exposed to natural or induced leaching conditions. Wooden objects treated by this method are left intact, such that they are not demolished or otherwise generated into a waste for more than one month, more than six months, more than one year, more than two years, more than five years or more than ten years after treatment with the stabilizing agent.
[0011] The present invention includes a method of reducing solubility of a heavy metal on a surface having painted thereon a heavy metal containing paint to reduce leaching or bioavailability of the heavy metal from said surface when the surface is exposed to natural or induced leaching conditions, consisting essentially of applying a stabilizing agent comprising phosphate, silicate, chloride, sulfate, a base, a source of iron ions or a combination thereof onto the surface having painted thereon the heavy metal containing paint to produce a treated paint, where the stabilizing agent binds to the heavy metal to form a heavy metal complex when exposed to natural or induced leaching conditions and where the treated paint is not removed from the surface. Typically, the heavy metal containing paint contains lead. A surface treated by this method is left intact, such that it is not demolished or otherwise generated into a waste (e.g., by sandblasting or high-pressure water treatment) for more than one month, more than six months, more than one year, more than two years, more than five years or more than ten years after treatment with the stabilizing agent.
[0012] In yet another embodiment, the present invention is a surface having painted thereon a heavy metal containing paint having applied thereto a stabilizing agent comprising phosphate, silicate, chloride, sulfate, a base, a source of iron ions or a combination thereof to produce a treated paint, where the stabilizing agent binds to the heavy metal to form a heavy metal complex when exposed to natural or induced leaching conditions to reduce leaching of the heavy metal from the surface when the surface is exposed to natural or induced leaching conditions. A surface treated by this method is left intact, such that it is not demolished or otherwise generated into a waste (e.g., by sandblasting or high-pressure water treatment) for more than one month, more than six months, more than one year, more than two years, more than five years or more than ten years after treatment with the stabilizing agent.
[0013] The present invention has the advantage of reducing surface solubility of various heavy metals, so as to reduce or prevent the leaching of the heavy metals from the surface of an object or reduce bioavailability of the heavy metals. This reduces the risk of soil contamination and toxicity to humans and other organisms. The sources of phosphate, silicate, chloride, sulfate, bases, and/or iron ions are readily available at a low cost, often making use of waste materials from other processes. Thus, the methods of the present invention represent an environmentally benign means of limiting heavy metal contamination.
DETAILED DESCRIPTION OF THE INVENTION
[0014] The present invention provides methods of reducing the solubility of heavy metals in heavy metal containing paint or wood, so as to reduce the leaching and bioavailability of heavy metals from such materials. Wood or wooden objects treated by methods of the present invention typically contain chromated copper arsenate or are painted with a heavy metal containing paint. Typically, wood treated by a method disclosed herein is unpainted, uncoated, and unsealed, such that the wood is bare. Other objects or surfaces painted with a heavy metal containing paint are also treatable by methods disclosed herein. Suitable objects or surfaces include those made of steel, iron, concrete, cement, plastic or other synthetic polymer, rubber or a natural polymer, paperboard, cardboard, fiberboard, fabric, asphalt, brick, stone and combinations thereof.
[0015] The term “leaching or leachable conditions,” as used herein, means any natural or induced condition that causes a heavy metal to solubilize and be removed from a heavy metal containing material. Natural or induced leaching conditions typically involve treating a material with water or rainwater that has a pH of 7 or less, typically 6 or less. The heavy metal containing material is treated with a stabilizing agent comprising phosphate, silicate, chloride, sulfate, a base, a source of iron ions or a combination thereof to form a heavy metal complex such as an insoluble heavy metal mineral. Preferably, the heavy metal complex is insoluble (e.g., the K sp is less than 10 −30 , 10 −40 , 10 −50 , 10 −60 , 10 −70 , or 10 −80 ). Formation of a heavy metal complex upon the surface of the heavy metal containing material will stabilize the heavy metal such that its leachability, under natural or induced leaching conditions, is reduced compared to its untreated form. A reduction in leaching can be assessed by any natural or induced leach test conditions such as, but not limited to, Toxicity Characteristic Leaching Procedure (TCLP, Method 1311), Simulated Precipitant Leaching Procedure (SPLP, Method 1310, which simulates rainwater leaching), Japan DI (uses acid adjusted deionized (DI) water for 6 hours to simulate rainwater leaching), Swiss sequential DI (uses sequential DI water leaching to simulate rainwater), rainwater, carbonated water, buffered citric acid (e.g., the California citric acid leaching test), acetic acid, distilled water, in vitro HCl-based bioavailability leach tests, the method involving deionized water described in Example 1, and other related methods.
[0016] The TCLP test is set forth in the Federal Register, vol. 55, no. 126, pp. 26985-26998 (Jun. 29, 1990) and described in the U.S. E.P.A. SW-846 manual. Briefly, in a TCLP test, 100 grams of material are tumbled with 2000 mL of diluted and buffered acetic acid for 18 hours. The extract TCLP solution is made up from 5.7 mL of glacial acetic acid and 64.3 mL of 1.0 N sodium hydroxide up to 1000 mL dilution with reagent water. SPLC uses the same tumbling procedure as the TCLP test, but replaces acetic acid with simulated acid rain (e.g., a solution of carbonic acid to pH 5.8 east of the Mississippi river and pH 5.9 west of the Mississippi river).
[0017] Suitable citric acid leach tests include the California Waste Extraction Test (WET), which is described in Title 22, Section 66700, “Environmental Health” of the California Health & Safety Code. Briefly, in a WET test, 50 grams of material are tumbled in a 1000 mL tumbler with 500 grams of sodium citrate solution for a period of 48 hours. The concentration of leached heavy metal is then analyzed by Inductively-Coupled Plasma (ICP) after filtration of a 100 ml aliquot from the tumbler through a 0.45 micron glass bead filter. A WET test result of greater than 5 ppm lead or 5 ppm arsenic will result in the soil being classified as hazardous in California.
[0018] The invention further pertains to methods of reducing the bioavailablity of heavy metals upon exposure to the stomach acids of animals or humans or other biological exposures. Bioavailability is the degree to which or rate at which a substance is absorbed or becomes available at the site of physiological activity after administration. Bioavailability can be assessed, in animals, for example, by studying metal uptake in the gastrointestinal tract and other organs.
[0019] A “stabilizing agent,” as used herein, causes one or more heavy metals to precipitate upon contact. The amount of stabilizing agent incorporated within and/or upon a material surface is determined based on the character of the material to be treated, the heavy metals present, desired heavy metal solubility reduction potential, desired heavy metal containing mineral toxicity, and desired heavy metal containing mineral formation relating to toxicological and site environmental control objectives. Heavy metals include, but are not limited to, copper, arsenic, chromium, lead, nickel, manganese, cobalt, zinc, cadmium, and mercury. Preferably, the heavy metal is arsenic or lead. Heavy metals are typically stabilized in a cationic form, but can optionally be stabilized as an elemental form or an anion (e.g., an oxyanion). More than one heavy metal can be treated simultaneously with a stabilizing agent. Stabilizing agents of the present invention comprise phosphate, silicate, chloride, sulfate, a base, a source of iron ions or a combination thereof and can contain one or more of the individual substances listed below.
[0020] Preferred stabilizing agents that contain phosphate include technical grade phosphoric acid, green phosphoric acid, wet process amber phosphoric acid, phosphoric and sulfuric acid blend coproduct or sodium chloride or calcium chloride amended phosphoric acid (phosphoric acid containing sodium chloride or calcium chloride). The term “wet process amber phosphoric acid” refers to phosphoric acid formed by acidolation of phosphate rock ore with sulfuric acid. The term “green phosphoric acid” refers to phosphoric acid formed by calcined ore acidolated with sulfuric acid. The term “phosphoric and sulfuric acid coproduct” refers to a by-product from the finishing of aluminum comprising phosphoric acid and sulfuric acid and optionally comprising aluminum and other metals (such as iron). In certain cases such as use of wet process amber and green phosphoric acid, such acids comprise sulfuric acid, vanadium, iron, aluminum and other complexing agents. Preferably, a stabilizing agent comprises phosphate and calcium. Another preferred stabilizing agent comprises phosphate and chloride, such as sodium chloride or calcium chloride amended phosphoric acid (e.g., where the sodium chloride or calcium chloride content is about 10% by weight).
[0021] Stabilizing agents comprising silicate include aqueous solutions of sodium silicate (e.g., where the sodium silicate content is about 10% by weight). Stabilizing agents comprising silicate preferably also contain phosphate.
[0022] Stabilizing agents, particularly arsenic stabilizing agents, contain iron ions, typically iron(II) and/or iron(III) ions. Preferred sources of iron ions include iron(III) chloride and iron(III) sulfate. Iron ions can be supplied by a surface or object being treated, particularly a surface or object that contains iron arsenate complexes, so that the stabilizing agent is contacted to the surface in the presence of a source of iron ions. For purposes of this invention, treating a surface with a stabilizing agent comprising one or more substances in the presence of a source of iron ions is considered to be equivalent to treating a surface with a stabilizing agent comprising both the one or more substances and a source of iron ions.
[0023] Stabilizing agents comprising a base typically comprise one or more basic salts, such as a alkaline or alkaline earth metal oxide, carbonate or bicarbonate. A preferred base is lime. Stabilizing agents comprising lime include aqueous solutions or slurries of calcium oxide, magnesium oxides and combinations thereof.
[0024] In one embodiment, a stabilizing agent comprises phosphate, silicate, iron ions or a combination thereof.
[0025] If a material contains arsenic, interaction of the stabilizing agent with arsenic typically forms a ferric-arsenate-base complex, a phosphate-calcium-arsenic complex (e.g., arsenic-substituted calcium phosphate crystals) or a phosphate-iron-arsenic complex. In such circumstances, the stabilizing agent contains phosphate and optionally iron ions. Calcium and iron can be present in the material being treated, in the stabilizing agent, or in a separate composition. The calcium and/or iron ions are typically applied as part of the stabilizing agent, but can also be applied simultaneously with the stabilizing agent or sequentially with the stabilizing agent. Under circumstances where both a source of iron ions and phosphate are applied, the source of iron ions is preferably applied before phosphate. Typical stabilizing agents for arsenic include a source of iron ions, often in the presence of a base, although the base is not required.
[0026] Preferably, if a material contains lead, interaction of the stabilizing agent with lead produces the mineral apatite lead phosphate (Ca 4 (Pb)(PO 4 ) 3 OH), lead phosphate (Pb 3 (PO 4 ) 2 ), lead silicate (PbSiO 3 ), lead sulfide (PbS), chloropyromorphite (Pb 5 (PO 4 ) 3 C1), plumbogummite, minerals containing iron (e.g., corkite), and combinations thereof. Typical stabilizing agents for lead include phosphate, often in combination with chloride and/or sulfate, although the latter anions are not required. Other typical stabilizing agents for lead include silicate, optionally in combination with one or more of the components listed above.
[0027] Stabilizing agents can be applied by a variety of methods, so long as a sufficient quantity of stabilizing agent adheres to a material or object being treated to reduce solubility of one or more heavy metals to a desired level. Preferably, a stabilizing agent is applied by a wet spray method. In a wet spray method, the stabilizing agent is applied to a material or object as a solution, liquid, or other sprayable formulation. Suitable solutions include dilute latex washes, which is a latex paint typically diluted with water or other suitable solvent. Latex paint comprising a stabilizing agent is further disclosed in U.S. Ser. No. 09/649,186, now U.S. Pat. No. 6,515,053, the entire teachings of which are incorporated herein by reference. Oil-based paint can also comprise a stabilizing agent. A stabilizing agent can be mixed with a stain or dye, such as a blended dye, so as to enable one to readily discern where the stabilizing agent has been applied or to give a surface or an object a visually pleasing appearance. Dyes and components of a solution, liquid or other sprayable formulation other than the stabilizing agent typically do not substantially contribute to the activity of a stabilizing agent and should not substantially interfere with the action of a stabilizing agent.
[0028] Stabilizing agents, optionally mixed with one or more other components, can also be applied to a material or object as a dry chemical or a dry slurry. The use of a dry chemical or slurry is indicated, for example, when treating a material that is saturated with water, such that application of a solution would not effectively penetrate the material. A dry chemical or dry slurry can contain a dye or stain. Dry chemicals and slurries can also contain an agent to assist in adhering the chemical or slurry to the surface being treated. Components of a dry chemical or dry slurry other than the stabilizing agent do not substantially contribute to the activity of a stabilizing agent and should not substantially interfere with the action of a stabilizing agent.
[0029] In another embodiment, a wiping device (e.g., made of paper, cloth, other woven natural or synthetic materials) is impregnated with a stabilizing agent, which can be present as a solution, dry chemical or dry slurry. Preferably, the wiping device is impregnated with a solution comprising a stabilizing agent. Such wiping devices are effective to reduce the solubility of heavy metals on surfaces, objects and materials disclosed herein. Also, such wiping devices can be used on organisms, particularly the skin of humans, after contact with a heavy metal or if contact with a heavy metal is suspected. This allows, for example, one to reduce the likelihood of exposure to a heavy metal by a hand-to-mouth route. Compounds other than a stabilizing agent can be present, so as to modify the pH of the stabilizing agent or assist in adhering the stabilizing agent to the wiping device. A wiping device intended for use on skin can also contain agents found in cosmetics such as moisturizers, cleansers, detergents, antimicrobials, antibiotics, scent, coloring agents and the like.
[0030] It does not appear that the concentration of stabilizing agent applied to a material is crucial to the invention, so long as the total amount of stabilizing agent applied is sufficient to reduce heavy metal solubility on the surface of a material to a desired level. For example, concentrations of P 2 O 5 ranging from 10% to 50% by weight have been found to be suitable in stabilizing agents. A surface typically only retains 1% to 5% by thin ({fraction (1/18)} inch) board weight of a composition containing a stabilizing agent. The remaining composition drips off of a surface unless the stabilizing agent is mixed with an adherent such as latex.
[0031] The amount of stabilizing agent required in the present method is minimal, especially in comparison with the amount of stabilizing agent required to treat a surface or an object that is becoming waste material (e.g., CCA-treated wood destined for a landfill, demolished structures, paint removed from a surface). Typically, a thin coating of a stabilizing agent is sufficient to reduce leaching of a heavy metal from an object or a surface that is substantially intact. Such thin coatings typically have a thickness of less than about 100 microns, less than about 50 microns, less than about 10 microns, less than about 5 microns, less than about 2 microns, less than about 1 micron, less than about 750 nm, less than about 500 nm, less than about 250 nm, less than about 100 nm or less than about 50 nm. While not being bound by theory, the thin coatings are expected to form a barrier over a surface and rapidly form insoluble crystals with heavy metals present in the surface, thereby reducing leaching.
[0032] Stabilizing agents can be applied to a material one or more times. Repeated or regular applications of a stabilizing agent can be made. Such repeated applications are particularly advantageous when a material contains a large amount of heavy metal, when a material is repeatedly exposed to leaching conditions, when additional heavy metal is brought to the surface of a material, when the material has a high moisture or solvent content, or when the surface of the material is weathered or abraded.
[0033] When an object or material painted with heavy metal based paint (e.g., lead based paint) is treated by a method disclosed herein, the paint is preferably not removed after treatment with a stabilizing agent. Most prior art relates to methods of stabilizing heavy metal based paint that is to be removed. The present method is particularly advantageous for minimization of heavy metal leaching from an object, when the object is to be exposed to leaching conditions over a period of time (e.g., an object that is exposed to weather). Also, methods disclosed herein are useful in treating painted objects where the cost of paint removal is too high, such as at large building structures or structures where the base paint retains a good adhesion character. In addition, the method of the present invention can be used to repair a breach or other fissure in a painted surface, so as to reduce leaching of heavy metals from or through the breach.
[0034] The examples below are merely illustrative of this invention and are not intended to limit the invention in any way.
[0035] Exemplification
EXAMPLE 1
[0036] A water leach test was conducted by submerging objects in a deionized water bath for 24 hours. The weight ratio of water to object was about 10 to 1. Objects subjected to the test included wood, steel and concrete objects painted with lead-based paint and CCA-treated wood. The painted objects were recovered from the South Boston convention center warehouse. Prior to the test, without curing, objects were treated by spraying one coat of stabilizer solution with 1% by weight solutions of technical grade phosphoric acid (HP), green phosphoric acid (WAG), wet process amber phosphoric acid (WAA), phosphoric and sulfuric acid blend coproduct (CP), 10% by weight sodium chloride amended phosphoric acid (WACL), 10% by weight aqueous sodium silicate (NS), ferric chloride (FC), ferric sulfate (FS), 1:1 mixtures of FC or FS and HP, or a 1% ferric chloride and 0.5% lime hydrate 1:1 water solution.
[0037] Following submersion in deionized water for 24 hours, the water was tested for the presence of lead (the objects with lead-based paint) or arsenic (the CCA-treated wood). Ten milliliter aliquot samples were submitted to Eastern Analytical Labs and measured by EPA method 200.7. The results are reported below in mg metal per L water.
1% 1% 1% 1% 1% 1% Object Control HP WAG WAA NS CP WACL Painted 0.29 <0.05 <0.05 <0.05 <0.05 <0.05 <0.05 Wood Painted 0.27 <0.05 <0.05 <0.05 <0.05 <0.05 <0.05 Steel Painted 0.32 <0.05 <0.05 <0.05 <0.05 <0.05 <0.05 Concrete 1% 1% 1% 1% 1% 1:1 1:1 FC/0.5% Object Control FC FS FC:WAA FS:WAA CaO (1:1 soln) CCA 0.15 ND ND 0.07 0.05 <0.05 Wood
[0038] While this invention has been particularly shown and described with references to preferred embodiments thereof, it will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the scope of the invention encompassed by the appended claims.
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Objects painted with heavy metal based paint, particularly lead based paint, and chromated copper arsenate-treated wood represent point sources of heavy metals. Humans can be exposed to the heavy metals either through direct contact with a surface containing heavy metal or by contacting heavy metals that leached from a surface, potentially leading to toxic or carcinogenic effects. The present invention provides methods of reducing the solubility of heavy metals, so as to reduce their leaching and bioavailability. The methods typically involve applying a stabilizing agent comprising phosphate, silicate, chloride, sulfate, a base (e.g., lime), a source of iron ions (e.g., ferric chloride, ferric sulfate) or a combination thereof to a surface.
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FIELD
The present invention is directed towards a safe handle wrapper for handles.
BACKGROUND
Modules operating on computer systems typically require access to shared resources. As examples, an application launched by an operating system may require access to files that are maintained by a file system, or the application may require access to network connections maintained by a network driver. Network drivers may require access to information structures maintained by a network packet classifier. This is a complex arrangement that includes numerous software modules, such as software drivers requiring access to many shared resources and an access supervisor that either maintains the resources or at least intercedes when a software module attempts to access a resource.
Intercession by an access supervisor is important for several reasons. For instance, when a first software module deletes a resource, other software modules that maintain direct pointers to the resource are unable to access or use the resource because their pointers no longer point to a valid resource. One solution to this problem is notifying software modules when a resource deletion occurs. However, this proposed solution requires detailed accounting and tracking of software modules and their respective pointers to the resources.
Another solution to this problem involves having an access supervisor intervene when a software module requires access to a particular resource. Such intervention ensures that a particular resource still exists before the software module is granted access to the particular resource. Typically, such intervention is accomplished by the access supervisor issuing a handle to each software module for a particular resource instead of allowing each software module a direct pointer to that particular resource.
A handle is associated with a resource and is used to refer to a particular resource when it is desired to be used by a software module. The software module does not use the handle to directly access the resource. Rather, the software module makes requests to the access supervisor for operations to be performed on the resource. The handle is presented as part of these requests to identify the resource that should be operated on. Further, multiple threads of a single program may request that operations be performed on the same resource by specifying the same handle to the access supervisor.
Handle administration systems are typically characterized by having handles that can assume either an allocated state or an unallocated state.
When a handle is in the allocated state, the access supervisor has associated that handle with a resource. The handle can then be used by a software module when the software module desires to perform an operation on the resource. To perform an operation on the resource, the software module makes a request to the access supervisor for a given operation and provides the handle to identify the resource on which the operation is to be performed. The access supervisor then checks to determine whether the handle is valid. If the handle is valid, then the operation may be performed. If the handle is not valid, then an appropriate notification to the software module may be generated.
When a handle is in the unallocated state, it is not associated with any resource and thus cannot be used to access a resource. A handle is in the unallocated state if it is never allocated or when it is “released.” A handle can be released by the software module that allocated it from the access supervisor. Releasing a handle means that the handle is no longer being used to access the resource with which it was formerly associated. Once a handle is released, it is available to be associated with another resource and thereby returned to the allocated state.
However, handles are not always released properly, and the consequences of an improper handle release can be quite costly in terms of performance and security. For example, a thread that opens a file may simply fail to close the file, resulting in a handle pointing to the file being leaked. Or, when a thread is terminated, a handle may fail to be released and the corresponding resource, to which the handle refers, may be leaked. Handle leaks like these can compromise program and overall computer performance over time, or simply cause a program to stop working.
Program security may further be compromised due to the eagerness by which handles are re-allocated. Such deficiencies are illustrated by the following example scenario in which Threads A and B concurrently execute semi-trusted code that requires access to the same publicly available file. Thread A may be assigned handle value X for the file, but execution of the semi-trusted code may switch to a different thread before a read operation is performed on the file. Thread B may then also use handle X for the same file, either maliciously or as a programming bug, perform a read operation on the file, close the file, and properly release handle X. Because handles are scarce resources, the access supervisor may soon thereafter allocate handle X to a Thread C, which executes fully trusted code. However, when Thread C reopens handle X, handle X may point to a completely different file. Therefore, when Thread A is re-started still using handle X, Thread A has access to the file intended for Thread C. Thus, thread management with semi-trusted code may result in security vulnerabilities in a multithreaded environment.
SUMMARY
Safe handles to implement safe, secure, and efficient management of handles are described herein.
Such management of handles includes wrapping a handle with a wrapper that enables, at least, secure and efficient creation, utilization, and releasing of handles.
BRIEF DESCRIPTION OF THE DRAWINGS
The detailed description is described with reference to the accompanying figures.
FIG. 1 shows a network environment in which example embodiments of safe handles may be implemented.
FIG. 2 shows an example of a safe handle.
FIG. 3 is a high level block diagram of an example of a handle administration system in accordance with the described embodiments.
FIG. 4 shows an example processing flow for implementing a safe handle.
FIG. 5 shows a processing flow for implementing a safe handle further to the example of FIG. 4 .
FIG. 6 illustrates a general computer network environment which can be used to implement the techniques described herein.
DETAILED DESCRIPTION
The following description is directed to techniques for efficiently and securely allocating, releasing, and re-allocating scarce resources such as handles. More particularly, a handle wrapper is described that eliminates certain resource leak vulnerabilities in a runtime environment and further eliminates certain handle recycling security vulnerabilities.
FIG. 1 shows server device 105 and client device 110 that are both capable of safe handle implementation 115 , in either of an operating system (OS) environment or in a runtime environment, in accordance with the example embodiments described herein. Server device 105 , client device 110 , and other data source 125 , which may also be capable of safe handle implementation, are communicatively coupled through network 120 .
Server device 105 may provide any of a variety of data and/or functionality to client device 110 . The data may be publicly available or alternatively restricted, e.g., restricted to only certain users or available only if an appropriate fee is paid. Server device 105 is at least one of a network server, an application server, a web blade, or any combination thereof. Other data source 125 may also be embodied by any of the above examples of server device 105 . An example embodiment of server device 105 is described in further detail below with reference to FIG. 6 .
Client device 110 may include any of a variety of conventional computing devices, including a desktop personal computer (PC), workstation, mainframe computer, Internet appliance, and gaming console. Further, client device 110 may be any device capable of being associated with network 120 by a wired and/or wireless link, including a personal digital assistant (PDA), laptop computer, cellular telephone, etc. Further still, client device 110 may include the client devices described above in various quantities and/or combinations thereof. Other data source 125 may also be embodied by any of the above examples of client device 110 . An example embodiment of client device 110 is also described in further detail below with reference to FIG. 6 .
Network 120 is intended to represent any of a variety of conventional network topologies, which may include any wired and/or wireless network. Network 120 may further utilize any of a variety of conventional network protocols, including public and/or proprietary protocols. For example, network 120 may include the Internet, an intranet, or at least portions of one or more local area networks (LANs).
Typically, server device 105 includes any device that is the source of content, and client device 110 includes any device that receives such content either via network 115 or in an off-line manner. However, according to the example embodiments described herein, server device 105 and client device 110 may interchangeably be a sending host or receiving host.
FIG. 2 shows an example embodiment of a “safe handle” 200 that is allocated for an agent requesting access to a resource in order to perform an operation on the resource. An agent is typically a software module that requires access to at least one resource in order for an operation to be performed. Such agents may be OS modules or runtime modules, and examples of such agents include dynamic link libraries (DLLs) and executable programs. The aforementioned resources may be any resource for which handles are used. Examples of such resources include files, data structures, or objects that are manipulated by agents.
More particularly, handle 210 is an identifier used to specify a resource on which operations are to be performed. Multiple possible representations of such identifier may exist. One such representation is an element in a handle database. A handle database may be used by a handle administrator to manage various handles (e.g., operating system handles) that may be used to access resources. Another possible representation is a pointer to the resource. To allocate a handle to a requesting agent, the handle administrator typically receives a call from the requesting agent. The handle administrator then establishes a relationship between the handle and the resource that the handle represents. The handle administrator then returns the handle to the requesting agent, and, thereafter, the handle is used to identify the resource on which an operation is to be executed. If the handle is valid, the operation requested by the requesting agent may be successful.
The handle may be released by the requesting agent when it is done performing operations on the resource it represents. As set forth above, releasing the handle means that the handle is no longer being used to access the resource with which it was formerly associated. A released handle is available to be associated with another resource and thereby returned to the allocated state. However, as further mentioned above, handles are not always released properly, and the consequences of an improper handle release can be quite costly in terms of performance and security.
Examples of the costly consequences of an improper handle release include a handle not being released when a thread is terminated, resulting in the handle being leaked; or a handle being released by only one of multiple threads using the same handle, resulting in security being compromised for the other threads.
As an example, consider CLR (common language runtime) on the Microsoft® .NET platform, which enables interaction of managed code with unmanaged code (e.g., Win32). In this environment, unmanaged code typically serves as a handle administrator, and therefore interacts with managed code to utilize the aforementioned resources. Without appropriate safeguards, the managed code may be interrupted before being able to properly release a handle obtained from the handle supervisor.
More particularly, a handle that is detected by the handle administrator as not being used, even though the handle is tentatively released or otherwise suspended, may be closed, disposed, or subjected to some other finalizing method for the purpose of memory management or resource recycling. For example, in the Microsoft® .NET platform, the managed method of “garbage collection” aggressively cleans up unused objects to reclaim memory. However, if garbage collection occurs prematurely on a type containing a handle and that type provides a finalizer that frees the handle, security of the corresponding resource and performance of a corresponding program can be severely compromised. The finalizer releases the resource and invalidates the handle. While resource release during finalization is normally expected, if the object was prematurely finalized (or disposed), another thread could still be using the contained handle of the object, which is now invalid. Further, a handle administrator (such as an operating system) enables a handle to be recycled, and thus the handle may be reallocated potentially with a different level of security, allowing a thread that used a prematurely finalized object to potentially access a different resource that it may not have permission to access. This is both a correctness and security problem.
To address at least these concerns described above, the example embodiment of a “safe handle” 200 in FIG. 2 further includes wrapper 205 encircling handle 210 . Wrapper 205 is either a data structure or software that contains, or wraps around, handle 210 . According to the present embodiment, wrapper 205 contains counter 215 to tabulate the number of threads currently using handle 210 . Alternative embodiments of wrapper 205 may further contain status flag 220 to indicate a current management status of handle 210 .
FIG. 3 shows an example embodiment of handle administration system 300 to implement safe handle 200 (see FIG. 2 ). Handle administrator 305 , which may correspond to a resource or access manager (not shown), may be implemented in any suitable hardware, software, firmware or combination thereof. A plurality of different agents 310 , 315 , and 320 are shown as consumers of resources 325 , 330 , and 335 .
As set forth above, agents 310 , 315 , and 320 are typically software modules, such as dynamic link libraries (DLLs) or executable programs that require access to any of resources 325 , 330 , and 335 to perform an operation. More particularly, agent 310 may be an OS module, and agents 315 and 320 may be runtime modules for the purposes of explaining the present embodiment. In relation to FIG. 1 , agents 310 , 315 , and 320 may be executable on server device 105 or client device 110 , either collectively or in various combinations.
As stated above, resources 325 , 330 , and 335 may be any resource for which handles are typically used. Examples of such resources include files, network connections, data structures, memory, or objects that are manipulated by the software modules.
Agents 310 , 315 , and 320 may require access to one or all of the resources, and, therefore a handle for a respective one of resources 325 , 330 , and 335 may be allocated to one or more of agents 310 , 315 , and 320 . In other words, a handle may be used by multiple threads, either as a matter of design or as a malicious attack vector.
Handle administrator 305 , which may be an OS module, generates and validates handles to be allocated to agent 310 requesting access to at least one of resources 325 , 330 , and 335 . Accordingly, handle administrator 305 uses handle 210 (see FIG. 2 ) to efficiently manage access to the resources 325 , 330 , and 335 on behalf of agent 310 .
Safe handle administrator 340 may be a runtime module. As either of agents 315 or 320 request access to any one of resources 325 , 330 , or 335 , safe handle administrator 340 generates safe handle object 200 for handle 210 (see FIG. 2 ), which may point to any one of resources 325 , 330 , or 335 . Safe handle administrator 340 may be invoked to create safe handle object 200 upon recognition of a subclass of a safe handle in the runtime environment. That is, in the runtime environment, when either of agents 315 or 320 call for handle 210 from handle administrator 305 , safe handle administrator 340 wraps handle 210 with wrapper 205 . Wrapper 205 typically includes counter 215 , though alternative embodiments may further include status flag 220 . The interaction between safe handle administrator 340 and handle administrator 305 to safeguard a handle from an OS environment in a runtime environment may be referred to as marshalling.
More particularly, counter 215 is incremented to “1” as safe handle administrator 340 associates safe handle 200 with a handle 210 . Counter 215 is then incremented by a value of 1 for every thread that begins executing an operation on the resource identified by the handle 210 and decremented by 1 when this operation is completed. When the requesting agent indicates it is done using the safe handle 200 , either explicitly or as a consequence of memory management methods (such as finalization), counter 215 is also decremented by “1”. Accordingly, safe handle administrator 340 is able to track the usage of handle 210 , and thereby prevent inadvertent or premature release of handle 210 . That is, when counter 215 is decremented to “0,” safe handle manager 340 allows handle 210 to be released. Attempts at using safe handle 200 after counter 215 reaches 0 fail in a well defined manner.
As stated previously, in alternative embodiments of safe handle 200 , wrapper 205 may include counter 215 and status flag 220 . Status flag 220 is an optional field which contains additional information which may be used in the determination of when the handle 210 should be released. For example, expedited release of a handle may be requested by a module in lieu of waiting for memory management methods to notice that the resource is unused. An expedited handle release operation includes decrementing counter 215 by 1 and releasing the handle when counter 215 reaches 0, otherwise the handle will be released as the last thread using the handle finishes its operations and decrements counter 215 to 0. However, counter 215 alone may not be sufficient to provide secure operation in a partially trusted environment since a malicious module could request an expedited handle release operation more than once, thus causing counter 215 to reach 0 while other threads are still using the handle. Thus, status flag 220 may be provided to record that an expedited release has been requested and refusing all further such operations for the respective safe handle.
FIG. 4 shows an example processing embodiment 400 for implementing a safe handle, with reference to the safe handle embodiment of FIG. 3 . Block 405 refers to an invocation by safe handle administrator 340 (see FIG. 3 ) to create safe handle object 200 . That is, at block 405 , a runtime environment may recognize the need to create an instance of a subclass of a safe handle, meaning that a safe handle is to be created for a runtime agent requiring a handle to access a resource upon which an operation is to be performed.
Block 410 refers to counter 215 being incremented to “1” as the runtime module referred to as safe handle administrator 340 (see FIG. 3 ) associates safe handle 200 with a handle 210 . More particularly, wrapper 205 which includes counter 215 and possibly status flag 220 is wrapped around handle 210 . This happens before any thread may perform an operation with newly created handle 210 .
Decision block 415 refers to safe handle administrator 340 determining whether a requesting thread may perform an operation on a safe handle 200 . More particularly, if safe handle administrator 340 determines that the value of counter 215 is 0 or that status flag 220 is set, then processing 400 proceeds to failure state 420 wherein usage of safe handle 200 fails.
Otherwise, block 425 refers to counter 215 being incremented by “1” before a particular thread performs an operation on the resource that safe handle 200 represents.
Block 430 refers to an operation occurring on the resource that safe handle 200 represents. As set forth above with regard to the particular example of the Microsoft® .NET platform, usage of safe handle 200 includes handle 210 being extracted from wrapper 205 in order to be passed to unmanaged code. The operation may be performed only after handle 210 is extracted from safe handle wrapper 205 . It is noted that the extraction of handle 210 may be executed by any runtime environment or safe handle administrator, not only the aforementioned Microsoft® .NET platform.
Block 435 refers to counter 215 being decremented by “1” once the operation on the resource that safe handle 200 represents is completed. The operations of blocks 425 , 430 , and 435 occur for each thread that performs an operation on the resource represented by handle 210 .
FIG. 5 continues processing flow 400 for implementing a safe handle further to the example of FIG. 4 . In particular, the continuation of processing flow 400 in FIG. 5 is directed towards the secure re-allocation of handles.
As set forth above with regard to FIG. 4 , block 430 refers to an operation occurring on the resource that safe handle 200 represents, and block 435 refers to counter 215 being decremented by “1” once the operation on the resource that safe handle 200 represents is completed.
Decision block 440 is attributed to safe handle administrator 340 (see FIG. 3 ) to check the status of counter 215 (see FIG. 2 ). Unless counter 215 is decremented to “0,” safe handle administrator 340 will not allow the release of handle 210 . Thus, if the counter is “1” or more, processing continues on towards block 445 , whereby use of the handle is maintained for the other threads that are currently performing operations on the resource it represents. However, if counter 215 is decremented to “0,” handle 210 is then released and made available for recycling at block 450 , i.e., re-allocation for another agent requesting access to a resource. For the counter 215 to be decremented to “0”, all threads should have completed any operations on the resource that the safe handle 200 represents and the requesting agent 310 , 315 or 320 should indicate that it is done using the safe handle 200 , either explicitly or as a consequence of memory management methods. As long as future attempts at using safe handle 200 fail (i.e., transition to failure state 420 ) and handle 210 has been exclusively used via safe handle 200 , then handle recycling security vulnerabilities are virtually eliminated.
In the above discussions regarding FIGS. 4 and 5 , the examples include incrementing and decrementing counter 315 by values of “1” and, further, safe handle administrator 340 allowing the release of handle 210 to occur only when counter 215 is at a base value of “0.” However, such descriptions are by example only, and are not intended (nor should they be construed) to be limiting. For example, with each additional thread using handle 210 , counter 215 may be incremented or even decremented by an integer value other than “1.” Similarly, for each thread that releases handle 210 , counter 215 may be decremented or even incremented by an integer value other than “1.”
FIG. 6 illustrates a general computer environment 600 , which can be used to implement safe handle 200 (see FIG. 2 ) described herein. The computer environment 600 is only one example of a computing environment and is not intended to suggest any limitation as to the scope of use or functionality of the computer and network architectures. Neither should the computer environment 600 be interpreted as having any dependency or requirement relating to any one or combination of components illustrated in the example computer environment 600 .
Computer environment 600 includes a general-purpose computing device in the form of a computer 602 , which may include server device 105 or client device 110 (see FIG. 1 ). The components of computer 602 can include, but are not limited to, one or more processors or processing units 604 , system memory 606 , and system bus 608 that couples various system components including processor 604 to system memory 606 .
System bus 608 represents one or more of any of several types of bus structures, including a memory bus or memory controller, a peripheral bus, an accelerated graphics port, and a processor or local bus using any of a variety of bus architectures. By way of example, such architectures can include an Industry Standard Architecture (ISA) bus, a Micro Channel Architecture (MCA) bus, an Enhanced ISA (EISA) bus, a Video Electronics Standards Association (VESA) local bus, a Peripheral Component Interconnects (PCI) bus also known as a Mezzanine bus, a PCI Express bus, a Universal Serial Bus (USB), a Secure Digital (SD) bus, or an IEEE 1394, i.e., FireWire, bus.
Computer 602 may include a variety of computer readable media. Such media can be any available media that is accessible by computer 602 and includes both volatile and non-volatile media, removable and non-removable media.
System memory 606 includes computer readable media in the form of volatile memory, such as random access memory (RAM) 610 ; and/or non-volatile memory, such as read only memory (ROM) 612 or flash RAM. Basic input/output system (BIOS) 614 , containing the basic routines that help to transfer information between elements within computer 602 , such as during start-up, is stored in ROM 612 or flash RAM. RAM 610 typically contains data and/or program modules that are immediately accessible to and/or presently operated on by processing unit 604 .
Computer 602 may also include other removable/non-removable, volatile/non-volatile computer storage media. By way of example, FIG. 6 illustrates hard disk drive 616 for reading from and writing to a non-removable, non-volatile magnetic media (not shown), magnetic disk drive 618 for reading from and writing to removable, non-volatile magnetic disk 620 (e.g., a “floppy disk”), and optical disk drive 622 for reading from and/or writing to a removable, non-volatile optical disk 624 such as a CD-ROM, DVD-ROM, or other optical media. Hard disk drive 616 , magnetic disk drive 618 , and optical disk drive 622 are each connected to system bus 608 by one or more data media interfaces 625 . Alternatively, hard disk drive 616 , magnetic disk drive 618 , and optical disk drive 622 can be connected to the system bus 608 by one or more interfaces (not shown).
The disk drives and their associated computer-readable media provide non-volatile storage of computer readable instructions, data structures, program modules, and other data for computer 602 . Although the example illustrates a hard disk 616 , removable magnetic disk 620 , and removable optical disk 624 , it is appreciated that other types of computer readable media which can store data that is accessible by a computer, such as magnetic cassettes or other magnetic storage devices, flash memory cards, CD-ROM, digital versatile disks (DVD) or other optical storage, random access memories (RAM), read only memories (ROM), electrically erasable programmable read-only memory (EEPROM), and the like, can also be utilized to implement the example computing system and environment.
Any number of program modules can be stored on hard disk 616 , magnetic disk 620 , optical disk 624 , ROM 612 , and/or RAM 610 , including by way of example, operating system 626 , one or more application programs 628 , other program modules 630 , and program data 632 . Each of such operating system 626 , one or more application programs 628 , other program modules 630 , and program data 632 (or some combination thereof) may implement all or part of the resident components that support the distributed file system.
A user can enter commands and information into computer 602 via input devices such as keyboard 634 and a pointing device 636 (e.g., a “mouse”). Other input devices 638 (not shown specifically) may include a microphone, joystick, game pad, satellite dish, serial port, scanner, and/or the like. These and other input devices are connected to processing unit 604 via input/output interfaces 640 that are coupled to system bus 608 , but may be connected by other interface and bus structures, such as a parallel port, game port, or a universal serial bus (USB).
Monitor 642 or other type of display device can also be connected to the system bus 608 via an interface, such as video adapter 644 . In addition to monitor 642 , other output peripheral devices can include components such as speakers (not shown) and printer 646 which can be connected to computer 602 via I/O interfaces 640 .
Computer 602 can operate in a networked environment using logical connections to one or more remote computers, such as remote computing device 648 . By way of example, remote computing device 648 can be a PC, portable computer, a server, a router, a network computer, a peer device or other common network node, and the like. Remote computing device 648 is illustrated as a portable computer that can include many or all of the elements and features described herein relative to computer 602 . Alternatively, computer 602 can operate in a non-networked environment as well.
Logical connections between computer 602 and remote computer 648 are depicted as a local area network (LAN) 650 and a general wide area network (WAN) 652 . Such networking environments are commonplace in offices, enterprise-wide computer networks, intranets, and the Internet.
When implemented in a LAN networking environment, computer 602 is connected to local network 650 via network interface or adapter 654 . When implemented in a WAN networking environment, computer 602 typically includes modem 656 or other means for establishing communications over wide network 652 . Modem 656 , which can be internal or external to computer 602 , can be connected to system bus 608 via I/O interfaces 640 or other appropriate mechanisms. It is to be appreciated that the illustrated network connections are examples and that other means of establishing at least one communication link between computers 602 and 648 can be employed.
In a networked environment, such as that illustrated with computing environment 600 , program modules depicted relative to computer 602 , or portions thereof, may be stored in a remote memory storage device. By way of example, remote application programs 658 reside on a memory device of remote computer 648 . For purposes of illustration, applications or programs and other executable program components such as the operating system are illustrated herein as discrete blocks, although it is recognized that such programs and components reside at various times in different storage components of computing device 602 , and are executed by at least one data processor of the computer.
Various modules and techniques may be described herein in the general context of computer-executable instructions, such as program modules, executed by one or more computers or other devices. Generally, program modules include routines, programs, objects, components, data structures, etc. for performing particular tasks or implement particular abstract data types. Typically, the functionality of the program modules may be combined or distributed as desired in various embodiments.
An implementation of these modules and techniques may be stored on or transmitted across some form of computer readable media. Computer readable media can be any available media that can be accessed by a computer. By way of example, and not limitation, computer readable media may comprise “computer storage media” and “communications media.”
“Computer storage media” includes volatile and non-volatile, removable and non-removable media implemented in any method or technology for storage of information such as computer readable instructions, data structures, program modules, or other data. Computer storage media includes, but is not limited to, RAM, ROM, EEPROM, flash memory or other memory technology, CD-ROM, digital versatile disks (DVD) or other optical storage, magnetic cassettes, magnetic tape, magnetic disk storage or other magnetic storage devices, or any other medium which can be used to store the desired information and which can be accessed by a computer.
“Communication media” typically embodies computer readable instructions, data structures, program modules, or other data in a modulated data signal, such as carrier wave or other transport mechanism. Communication media also includes any information delivery media. The term “modulated data signal” means a signal that has one or more of its characteristics set or changed in such a manner as to encode information in the signal. As a non-limiting example only, communication media includes wired media such as a wired network or direct-wired connection, and wireless media such as acoustic, RF, infrared, and other wireless media. Combinations of any of the above are also included within the scope of computer readable media.
Reference has been made throughout this specification to “one embodiment,” “an embodiment,” or “an example embodiment” meaning that a particular described feature, structure, or characteristic is included in at least one embodiment of the present invention. Thus, usage of such phrases may refer to more than just one embodiment. Furthermore, the described features, structures, or characteristics may be combined in any suitable manner in one or more embodiments.
One skilled in the relevant art may recognize, however, that the invention may be practiced without one or more of the specific details, or with other methods, resources, materials, etc. In other instances, well known structures, resources, or operations have not been shown or described in detail merely to avoid obscuring aspects of the invention.
While example embodiments and applications of the present invention have been illustrated and described, it is to be understood that the invention is not limited to the precise configuration and resources described above. Various modifications, changes, and variations apparent to those skilled in the art may be made in the arrangement, operation, and details of the methods and systems of the present invention disclosed herein without departing from the scope of the claimed invention.
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Enabling secure and efficient marshaling, utilization, and releasing of handles in either of an operating system or runtime environment includes wrapping a handle with a counter to tabulate a number of threads using currently using the handle. Thus, handle administration is implemented to circumvent potential security risks, avoid correctness problems, and foster more efficient handle releasing.
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CROSS-REFERENCE TO RELATED APPLICATION
This application is a Section 371 National Stage Application of International Application No. PCT/CN2012/079401, filed Jul. 31, 2012 and published as WO 2014/012275 A1 on Jan. 23, 2014, which claims priority to Chinese Application No. 201210250438.6, entitled “SEMICONDUCTOR DEVICE AND METHOD FOR MANUFACTURING THE SAME,” filed on Jul. 19, 2012, which is incorporated herein by reference in their entirety.
TECHNICAL FIELD
The present disclosure relates to the semiconductor field, and particularly, to a semiconductor device and a method for manufacturing the same.
BACKGROUND
With continuous scaling down of semiconductor devices, short channel effects are becoming more significant. On solution to suppress the short channel effects is to reduce the junction depth of source/drain extension regions. To form such shallow extension regions, it is necessary to adopt low-energy ion implantation in extension implantation, followed by ultra-short annealing to activate implanted ions. This poses challenges on manufacture apparatus and manufacture processes.
On the other hand, the ion implantation may cause substrate damages. Thus, an additional annealing process is needed to remove the damages.
SUMMARY
The present disclosure provides, among others, a semiconductor device and a method for manufacturing the same.
According to an aspect of the present disclosure, there is provided a method for manufacturing a semiconductor device, comprising: growing a first epitaxial layer on a substrate; forming a sacrificial gate stack on the first epitaxial layer; selectively etching the first epitaxial layer; growing and in-situ doping a second epitaxial layer on the substrate; forming a spacer on opposite sides of the sacrificial gate stack; and forming source/drain regions with the spacer as a mask.
According to a further aspect of the present disclosure, there is provided a semiconductor device, comprising: a gate stack formed on a substrate; a first epitaxial layer, which is in-situ doped and grown on the substrate, and is configured as source/drain extension regions; and source/drain regions.
BRIEF DESCRIPTION OF THE DRAWINGS
The above and other objects, features, and advantages of the present disclosure will become apparent from following descriptions of embodiments with reference to the attached drawings, in which:
FIGS. 1-6 are schematic views showing a flow of manufacturing a semiconductor device according to an embodiment of the present disclosure; and
FIGS. 7-14 are schematic views showing a flow of manufacturing a semiconductor device according to a further embodiment of the present disclosure.
DETAILED DESCRIPTION
Hereinafter, descriptions are given with reference to embodiments shown in the attached drawings. However, it is to be understood that these descriptions are illustrative and not intended to limit the present disclosure. Further, in the following, known structures and technologies are not described to avoid obscuring the present disclosure unnecessarily.
In the drawings, various structures according to the embodiments are schematically shown. However, they are not drawn to scale, and some features may be enlarged while some features may be omitted for sake of clarity. Moreover, shapes and relative sizes and positions of regions and layers shown in the drawings are also illustrative, and deviations may occur due to manufacture tolerances and technique limitations in practice. Those skilled in the art can also devise regions/layers of other different shapes, and relative sizes and positions as desired.
In the context of the present disclosure, when a layer/element is recited as being “on” a further layer/element, the layer/element can be disposed directly on the further layer/element, or otherwise there may be an intervening layer/element interposed therebetween. Further, if a layer/element is “on” a further layer/element in an orientation, then the layer/element can be “under” the further layer/element when the orientation is turned.
Next, an embodiment of the present disclosure will be described in detail with reference to FIGS. 1-6 .
As shown in FIG. 1 , a substrate 1000 is provided. The substrate 1000 may comprise any suitable substrate, including, but not limited to, a bulk semiconductor substrate such as a bulk Si substrate, a Semiconductor on Insulator (SOI) substrate, a SiGe substrate, and the like. For convenience, the following descriptions are given with respect to the bulk Si substrate by way of example.
On the substrate 1000 , an epitaxial layer 1004 may be grown by means of, for example, epitaxy. For example, the epitaxial layer 1004 may comprise SiGe (where an atomic percentage of Ge can be about 10%), with a thickness of about 5-10 nm. The thickness of the epitaxial layer 1004 substantially determines a thickness of source/drain extension regions to be formed later.
Subsequently, as shown in FIG. 2 , on the epitaxial layer 1004 , a sacrificial gate stack may be formed. For example, the sacrificial gate stack can be formed by sequentially depositing an oxide layer 1006 and a nitride layer 1008 and then patterning them. It is to be noted that there are various ways to form the sacrificial gate stack. The sacrificial gate stack comprising the oxide layer 1006 and the nitride layer 1008 , as shown in FIG. 2 , is just an example. According to embodiments of the present disclosure, the sacrificial gate stack preferably comprises a dielectric material such as oxide, nitride or a combination thereof, instead of a crystal semiconductor material (e.g., polysilicon), for convenience of following processes. It is intended to prevent following selective epitaxy from occurring at the sacrificial gate stack.
Next, as shown in FIG. 3 , the epitaxial layer 1004 may be subjected to selective etching. Such selective etching may be accomplished by wet etching, dry etching, or a combination thereof. Due to the etching selectively between the epitaxial layer 1004 (e.g., SiGe) and the substrate (e.g., Si), the etching can be stopped on the substrate 1000 . A portion of the epitaxial layer 1004 underlying the sacrificial gate stack can be reserved due to the presence of the sacrificial gate stack. In the example shown in FIG. 3 , lateral edges of the etched epitaxial layer 1004 are illustrated as being slightly recessed with respect to respective lateral edges of the sacrificial gate stack by an extent which can be controlled by conditions in the etching process.
Then, as shown in FIG. 4 , an epitaxial layer 1010 may be grown on portions of the substrate 1000 exposed by the above selective etching by means of, for example, epitaxy. The epitaxial layer 1010 may comprise Si. Because the sacrificial gate stack comprises dielectric materials such as oxide and nitride, the epitaxy will not occur at surfaces of the sacrificial gate stack. The epitaxial layer 1010 can be doped in-situ into an appropriate conductivity type while being grown. For example, for an n-type device, the epitaxial layer 1010 may be doped with n-type impurities, such as As or P, into the n-type; while for a p-type device, the epitaxial layer 1010 may be doped with p-type impurities, such as In, BF 2 , or B, into the p-type. The in-situ doped epitaxial layer 1010 can serve as extension regions of the device to be formed.
Next, as shown in FIG. 5 , a spacer 1012 may be formed on opposite sides of the sacrificial gate stack. For example, the spacer 1012 may comprise silicon nitride, silicon oxide, or a combination thereof. There are various ways to form the spacer, and thus detailed descriptions thereof are omitted here.
Subsequently, as shown in FIG. 6 , source/drain regions 1014 may be formed with the spacer as a mask. For example; the source/drain regions 1014 may be formed by means of ion implantation. Specifically, for an n-type device, n-type impurities such as As or P may be implanted; while for a p-type device, p-type impurities may be implanted. Following the ion implantation, annealing can be carried out to activate implanted ions.
After that, a gate replacement process can be performed. Specifically, the sacrificial gate stack (comprising the nitride layer 1008 and the oxide layer 1006 in this example) can be removed by selective etching, resulting in a groove inside the spacer. Then, a gate dielectric layer and a gate conductor can be filled into the groove, to form a true gate stack. For example, the gate dielectric layer may comprise a high-K gate dielectric, and the gate conductor may comprise a metal gate conductor.
Thus, a semiconductor device according to an embodiment of the present disclosure is achieved. As shown in FIG. 6 , the semiconductor device comprises the in-situ doped epitaxial layer 1010 formed on the substrate. The epitaxial layer 1010 (especially, portions thereof close to a channel region) servers as the source/drain extension regions 1016 of the semiconductor device. The epitaxial layer 1010 has its thickness substantially determined by the thickness of the epitaxial layer 1004 , due to its formation process. In other words, the thickness of the epitaxial layer 1004 substantially determines the depth of the extension regions 1016 . Because the thickness of the epitaxial layer 1004 grown on the substrate can be controlled in a relatively accurate manner to be relatively thin, it is possible to from the extension regions 1016 which are relatively shallow. Further, the extension regions 1016 can be in-situ doped while being grown. As a result, it is possible to avoid ion implantation and thus avoid ultra-short annealing thereon.
Hereinafter, a further embodiment of the present disclosure will be described in detail with reference to FIGS. 7-14 .
As shown in FIG. 7 , a substrate 2000 is provided. The substrate 2000 may comprise any suitable substrate, including, but not limited to, a bulk semiconductor substrate such as a bulk Si substrate, a Semiconductor on Insulator (SOI) substrate, a SiGe substrate, and the like. For convenience, the following descriptions are given with respect to the bulk Si substrate by way of example.
On the substrate 2000 , an epitaxial layer 2002 may be grown by means of, for example, epitaxy. For example, the epitaxial layer 2002 may comprise SiGe (where an atomic percentage of Ge can be about 10%), with a thickness of about 30-50 nm. The thickness of the epitaxial layer 2002 substantially determines a thickness of source/drain regions to be formed later.
Further, on the epitaxial layer 2002 , a further epitaxial layer 2004 may be grown by means of, for example, epitaxy. For example, the epitaxial layer 2004 may comprise Si, with a thickness of about 5-10 nm. The thickness of the epitaxial layer 2004 substantially determines a thickness of source/drain extension regions to be formed later.
Subsequently, as shown in FIG. 8 , on the epitaxial layer 2004 , a sacrificial gate stack may be formed. For example, the sacrificial gate stack can be formed by sequentially depositing an oxide layer 2006 and a nitride layer 2008 and then patterning them. As for the sacrificial gate stack, reference may be made to the above descriptions in conjunction with FIG. 2 .
Next, as shown in FIG. 9 , the epitaxial layer 2004 may be subjected to selective etching. Such selective etching may be accomplished by wet etching, dry etching, or a combination thereof. Due to the etching selectively between the epitaxial layer 2004 (e.g., Si) and the epitaxial layer 2002 (e.g., SiGe), the etching can be stopped on the epitaxial layer 2002 . A portion of the epitaxial layer 2004 underlying the sacrificial gate stack can be reserved due to the presence of the sacrificial gate stack. In the example shown in FIG. 9 , lateral edges of the etched epitaxial layer 2004 are illustrated as being slightly recessed with respect to respective lateral edges of the sacrificial gate stack by an extent which can be controlled by conditions in the etching process.
Then, as shown in FIG. 10 , an epitaxial layer 2010 may be grown on portions of the epitaxial layer 2002 exposed by the above selective etching by means of, for example, epitaxy. The epitaxial layer 2010 may comprise Si. Because the sacrificial gate stack comprises dielectric materials such as oxide and nitride, the epitaxy will not occur at surfaces of the sacrificial gate stack. The epitaxial layer 2010 can be doped in-situ into an appropriate conductivity type while being grown. For example, for an n-type device, the epitaxial layer 2010 may be doped with n-type impurities, such as As or P, into the n-type; while for a p-type device, the epitaxial layer 2010 may be doped with p-type impurities, such as In, BF 2 , or B, into the p-type. The in-situ doped epitaxial layer 2010 can serve as extension regions of the device to be formed.
Next, as shown in FIG. 11 , a spacer 2012 may be formed on opposite sides of the sacrificial gate stack. For example, the spacer 2012 may comprise silicon nitride, silicon oxide, or a combination thereof. There are various ways to form the spacer, and thus detailed descriptions thereof are omitted here.
Subsequently, as shown in FIG. 12 , the epitaxial layer 2020 and the epitaxial layer 2002 may be subjected to selective etching with the spacer as a mask. Such selective etching may be accomplished by wet etching, dry etching, or a combination thereof. Due to the presence of the sacrificial gate stack and the spacer, portions of the epitaxial layer 2020 and the epitaxial layer 2002 underlying them are reserved.
Then, as shown in FIG. 13 , an epitaxial layer 2014 may be grown on portions of the substrate 2000 exposed by the above selective etching by means of, for example, epitaxy. The epitaxial layer 2014 may comprise Si. Because the sacrificial gate stack comprises dielectric materials such as oxide and nitride, the epitaxy will not occur at surfaces of the sacrificial gate stack. The epitaxial layer 2014 can be doped in-situ into an appropriate conductivity type while being grown. For example, for an n-type device, the epitaxial layer 2014 may be doped with n-type impurities, such as As or P, into the n-type; while for a p-type device, the epitaxial layer 2014 may be doped with p-type impurities, such as In, BF 2 , or B, into the p-type. The in-situ doped epitaxial layer 2014 can serve as source/drain regions of the device to be formed. Further, the remaining portions of the in situ doped epitaxial layer 2010 can serve as the source/drain extensions 2016 of the device.
According to an example of the present disclosure, to improve performances of the device, the epitaxial layer 2014 may comprise SiGe (for a p-type device, where an atomic percentage of Ge can be greater than about 30%) or Si:C (for an n-type device). The epitaxial layer 2014 in such a configuration can apply stress to a channel region of the device, so as to enhance the mobility of carriers and thus improve the performances of the device.
After that, a gate replacement process can be performed. Specifically, the sacrificial gate stack (comprising the nitride layer 2008 and the oxide layer 2006 in this example) can be removed by selective etching, resulting in a groove inside the spacer. Then, a gate dielectric layer 2018 and a gate conductor 2020 can be filled into the groove, to form a true gate stack. For example, the gate dielectric layer 2018 may comprise a high-K gate dielectric, and the gate conductor 2020 may comprise a metal gate conductor. There may be further a work-function adjustment layer (not shown) interposed between the gate dielectric layer 2018 and the gate conductor 2020 . Then, an inter-layer dielectric layer 2022 (e.g., oxide) may be formed by means of, for example, deposition, and then subjected to CMP, resulting in the semiconductor device shown in FIG. 14 .
As shown in FIG. 14 , the semiconductor device comprises a gate stack (including the gate dielectric layer 2018 and the gate conductor 2020 ) formed on the substrate. The in-situ doped epitaxial layer 2010 serves as the source/drain extension regions 2016 of the semiconductor device. Like the above described embodiment, the extension regions 2016 formed in such a way can be controlled to be relatively shallow, and also it is possible to avoid ion implantation.
Further, the semiconductor device comprises the source/drain regions formed of the epitaxial layer 2014 . Likewise, the source/drain regions can be in-situ doped while being grown. As a result, it is possible to avoid ion implantation and thus avoid ultra-short annealing thereon.
From the foregoing, it will be appreciated that specific embodiments of the disclosure have been described herein for purposes of illustration, but that various modifications may be made without deviating from the disclosure. In addition, many of the elements of one embodiment may be combined with other embodiments in addition to or in lieu of the elements of the other embodiments. Accordingly, the technology is not limited except as by the appended claims.
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A semiconductor device and a method for manufacturing the same are provided. In one embodiment, the method comprises: growing a first epitaxial layer on a substrate; forming a sacrificial gate stack on the first epitaxial layer; selectively etching the first epitaxial layer; growing and in-situ doping a second epitaxial layer on the substrate; forming a spacer on opposite sides of the sacrificial gate stack; and forming source/drain regions with the spacer as a mask.
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FIELD OF THE INVENTION
Whenever any kind of excavation is carried out, either as an open pit, or underground, as in the case of a tunnel, the time comes after a certain stage has been reached in the work, that there is an alteration in the state of tension, commonly termed a subsidance, which takes place around the face being worked and where dynamiting is carried out; this being due to the earth previously supporting the sides (and the roof if it is a tunnel) having been removed in the course of the job being undertaken. This situation may come about either gradually, or it may arise suddenly, due to the effects of blasting.
Unfortunately these considerations must always be looked at from the theoretical point of view only, and they have no application in actual practice, since the characteristics of the ground being excavated are liable to vary so much that they cannot be used as a reliable means at all on which to base safety precautions. On the other hand, modern civil engineering practice is such that work is required to be carried out with such expediency and efficiency that this situation involving subsidence of the soil must be considered of paramount importance in order to avoid personal and material accidents and injuries which could occur if the subsidence was to give rise to a landslide.
DESCRIPTION OF THE PRIOR ART
The traditional practice employed to alleviate the effects of subsidence entails the use of shoring, comprising a series of frame having the same shape as the inside of the excavation, these being what are known as trusses when used in tunnels; and other members called longitudinals, which are placed perpendicularly to the trusses, thus lining the inside of the tunnel with a conventional shoring arrangement.
This type of shoring has the disadvantage of being extremely laborious to erect, and it inevitably makes the job much longer than it would otherwise need to be, were it not for the safely considerations involved to prevent accidents.
SUMMARY OF THE INVENTION
The embodiment proposed under the present invention, allows considerable improvements to be made to shoring arrangements in excavation work, enabling erection to be undertaken very rapidly indeed, and also counteracting the effects of subsidence to an acceptable degree; while at the same time it even detects serious cases of subsidence, which because of their nature, may require other arrangements to be made to counteract them and remove danger.
DESCRIPTION OF THE DRAWINGS
Embodiments of the invention will now be described by way of illustration with reference to the accompanying drawings showing a schematic arrangement of the application. Such schematic arrangement is in no way to be construed as imposing any limitations on the embodiment, and it may therefore be subject to those slight alterations which do not affect its essential features.
Referring to FIG. 1, this shows a longitudinal cross-sectional view of a tunnel shored in accordance with the invention.
FIG. 2 is an enlarged detail view of the section marked 10 in FIG. 1.
FIG. 3 is a plan view of part of the modular plating units.
FIG. 4 is a sectional view on plane 11 -- 11 shown in FIG. 3,
FIG. 5 is a sectional view on plane 12 -- 12 shown in FIG. 3.
FIG. 6 illustrates the application of the invention as shoring in an ordinary open pit.
The following legend is used in the accompanying drawings to identify the different parts of the embodiment and its location as listed below:
1 -- Frames or trusses.
2 -- Modular plating units.
3 -- Convex trapeziforms.
4 -- Joining segments.
5 -- Concave trapeziforms.
6 -- Windows.
7 -- Outer edges.
8 -- Soil or rock.
9 -- Concrete.
10 -- Section.
11 -- Section.
12 -- Section.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
In accordance with the improvements allowed for with the embodiment, and which are especially suited for shoring in excavations where the work needs to be undertaken with the utmost care, or where it is required to compensate for, or measure subsidence taking place in the vicinity of the face being worked, the procedure adopted is to place frames or trusses 1 in the hollow dug out, these having a shape similar to the section of the hollow, and it is on these trusses 1 where modular plating units 2 are supported, these being fabricated from steel pressings with a special design insofar that they have polygonal shaped leading edges, each made up from trapeziforms with alternate sides parallel to one another 3 and 5, being open at the wider end and bridged at the narrow end by means of segments 4 arranged alternately as concaves and convexes on each successive pair of units, and having outer edges 7 in their section as shown in the drawings. The space between modular plating units 2 and the soil 8 is filled with concrete 9, placed in position by any conventional means, in such a way that modular plating units 2 become attached to the inside surface of the excavation.
In this way, subsidence of the ground is prevented to a very large degree, since all fresh surfaces uncovered 8 in the course of digging, are immediately held secure by the inner supporting lining. The chief advantage derived from these improvements comes about as the result of the plating units having a polygonal shaped surface, which is considerably better than other means commonly used for shoring, because their mechanical strength is such as to enable them to withstand more satisfactorily the type of stressing brought about by forces imposed from the overlying soil. Moreover, edges 7 of the channels are designed so as to comprise lines where strains are concentrated, and can act as flexing points without stressing or affecting the rigid plates themselves, thus allowing the plating to adapt itself to the shape of the inside of the excavation. Such adaption is achieved because of the flexibility of the steel comprising the plate subjected to stressing along the length of the flexing edges as described, so that any slight local excess pressure is absorbed.
There is another extremely important effect which is achieved with this shoring arrangement having beams with flexing edges, and which is that any dangerous overstressing brought about from pressure in the surrounding soil can be quickly detected, because the edges of the beams will become noticeably deformed in way of the area in question. Hence, such deformations can be used to pin point places where subsidence has or is taking place, and which may require special reinforcement.
When the beams described in this invention are used as permanent shuttering for lining tunnels or open pits with concrete, the fact that the faces are parallel to the longitudinal centre line of the beams, and therefore to the face of the excavation, means that they contribute considerably to reinforcing the concrete. When applied to tunnels, the plates can be fabricated with a suitable curvature to allow them to adapt themselves to the cross-section as required.
The remaining faces, oblique to those just mentioned, serve the purpose of absorbing shear stresses set up in the concave face of the tunnel or pit at the periphery of the lining, thus preventing cracks from beginning; these being something which usually extend towards the inside of the hollow when the lining is made of concrete, and they are visible in any tunnel lined with this kind of material.
In order to obtain an increased degree of strength binding between plate unit 2 and the concrete, the former may have a layer of gunnite or concrete containing metal or glass fibre, extended over its surface to a suitable thickness. Such layer, in addition to improving strength performance, will help to protect the plate against corrosion.
A further noteworthy improvement achieved with the present invention concerns the need for all shoring to be strictly checked under difficult conditions, and frequently using only semi-skilled labour to do so. This means that any improvement allowing the erection of the shoring to be done more quickly and with increased simplicity is bound to be an advantage. The advantage achieved in this particular case is that as plates 2 are fabricated steel pressings, they are sufficiently rigid to allow the actual thickness of the material to be reduced without prejudicing strength, so that they are lighter in weight and can be more readily handled than members used in conventional shoring arrangements. More particularly, the advantage is derived from the fact that between each pair of adjoining and therefore opposing trapeziforms 3 and 5, windows 6 are arranged in the form of gaps which make one of the trapeziforms narrower than the other, so that the width of convex trapeziform 3 is greater than that of concave trapeziform 5. Hence, when two modular plate units are overlapped upon being assembled together, such assembly can be easily carried out, since these windows 6 allow play and tolerance to take up any deformation there may have been in the plates either during manufacture, storage or handling. Hence, erection can be smoothly undertaken without difficulties, thus contributing appreciably to the rapidity with which it can be completed.
The simplest way of erecting the modular plate units 2 to make a shoring, is to place the frames or trusses 1 in position first, these being such that their outside edge is about the same shape as the cross-section of the excavation. Modular plate units 2 are then arranged on these trusses 1, and as work on erection of the shuttering progresses, the space between the shoring and the soil 8 is filled with concrete, using either a pump of the type specially designed for this purpose, or any other conventional means normally employed in accordance with this kind of civil engineering technology. Correct size grading of the aggregate in the concrete, a suitably dry mixture to afford proper consistency of the mix, and careful filling of the shuttering, with particular care being paid to proper use of the vibrating rod to ensure this, are all important requirements to be borne in mind to prevent the mix from flowing out through the gaps in the polygonal shaped plates used to make up the shuttering.
Obviously the use of ordinary of oblique reinforcing members, should these be necessary to take up any considerable shear stresses which may arise, or the use of side shuttering, front shuttering for lining tunnels in the usual manner or for filling with concrete back up from the end of the tunnel, and any other technique among those which are traditionally used in this branch of civil engineering are all perfectly applicable in this invention, because in addition to deriving from each of their own peculiar and proven advantages, they will be improved to the extent of the embodiments described herein.
When plates 2 are assembled with others, overlapping is perfectly well achieved through contact between the faces lying parallel to one another, together with that between the protruding edges and the oblique surfaces, all in such a way that the fit allows no freedom or looseness, and there is an efficient coupling between the members.
The distance between trusses 1 will obviously depend on the characteristics of the ground to be shored, although in most cases this is roughly 1 meter.
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A shoring system provides trapezoidal pockets in modular plating units. The junction of planes in the trapezoids provides mechanical strength and deformation sites at which deformation can be seen.
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[0001] This application is a Division of U.S. patent application Ser. No. 12/780,726, filed on May 14, 2010 which claims priority from Korean Patent Application No. 10-2009-0117186 filed on Nov. 30, 2009 in the Korean Intellectual Property Office, the disclosures of both said applications being incorporated herein by reference in their entireties.
BACKGROUND
[0002] 1. Field of Disclosure
[0003] The present disclosure of invention relates to a display device, a thin-film transistor (TFT) structure, and a method of fabricating the TFT substrate, and more particularly, to a TFT based display device with maintained aperture ratio and minimized kickback voltage despite increased size of drain contact hole. The disclosure also relates to an Liquid Crystal Display (LCD) having a TFT array substrate that uses the here taught TFT structures, and a method of fabricating the LCD.
[0004] 2. Description of Related Technology
[0005] Liquid crystal displays (LCDs) are one of the most widely used types of flat panel displays. Generally, an LCD includes two spaced apart substrates both having electrodes and a liquid crystal layer interposed between the substrates. In an LCD, voltages are applied to the electrodes to generate electric fields through the liquid crystal layer. The electric field determines an alignment of molecules in the liquid crystal layer, thereby controlling an amount of light that passes through light polarizing layers of the LCD.
[0006] Of the two substrates included in an LCD, one is typically referred to as the thin-film transistor (TFT) array substrate and it includes a plurality of pixel units organized in an array format and each having one or more thin-film transistors (TFTs) and one or more pixel electrodes. Traditionally, the other substrate (common electrode substrate) contains a color filters layer. However, recently, research into a Color on Array (COA) structure has intensified wherein the CoA structure provides color filters on the TFT substrate instead of on the common electrode substrate. Part of the research is directed to ways to improve the planarization, alignment, and optical characteristics of LCDs using the CoA structure. In particular, research is being conducted on ways to improve planarization characteristics of TFT substrates having the COA structure in order to increase the reliability of the TFT substrate. One research direction looks at ways to increase the thickness of a planarization film as a way to improve the planarization characteristics of a CoA structure.
[0007] However, when the thickness of the planarization film is increased, a width of a contact-providing through hole in the pixel unit structure generally needs to also increase. More specifically, it is a drain to pixel-electrode contact through hole that is provided in a light blocking or black-masked area of the pixel unit that generally needs to increase in size. As the hole size increases, however, a drain electrode beneath it also has to increase in size according to traditional design methodologies so as to assure proper registration with the widened hole. More specifically, when the contact hole in question is the one to the TFT drain and the area of the underlying drain electrode has to be increased to prevent the occurrence of an overlay miss between the drain electrode and the contact hole, several disadvantages flow from this result (from increased drain electrode area).
[0008] Firstly, the value of an undesirable parasitic capacitance between the drain and gate nodes of the TFT tends to increase. Secondly, the increased drain electrode size operates to reduce an aperture ratio (e.g., a ratio of the light passing portion versus light blocking portions of each of the repeated pixel units in the LCD. The reduction in the aperture ratio can deteriorate image quality and waste backlighting power. Also the increased size of the drain contact hole can lead to undesired leakage of light around the contact hole area.
SUMMARY
[0009] The present disclosure of invention provides methods of fabricating thin-film transistor (TFT) based pixel units having an increased or maintained aperture ratio and maintained or minimized parasitic capacitance between drain and gate nodes of the TFT so that excessive kick back voltage is suppressed.
[0010] The present teachings are not restricted to just the embodiments set forth herein as examples. Various aspects of the present teachings will become more apparent to one of ordinary skill in the art to which the present teachings most closely pertain by referencing the detailed description as given below.
[0011] According to an aspect of the present disclosure, there is provided a method of fabricating a TFT array substrate. The method includes: forming a gate electrode in a repeated pixel unit region of a substrate; forming a gate insulating film on the gate electrode; forming a semiconductor layer portion on the gate insulating film to overlap the gate electrode; forming a source electrode and a spaced apart drain electrode to overlap the semiconductor layer and to thus form a channel region; forming a channel passivating film that covers the exposed channel surface between the source and drain electrodes but does not cover the drain electrode, and forming a data insulating film on the source electrode and the drain electrode and patterning the data insulating film to form a through hole directed to contacting the drain electrode wherein part of the formed contact hole may overlap the passivated channel region and yet not create substantial deterioration of TFT performance.
[0012] According to another aspect of the present disclosure, there is provided a TFT array substrate including: a gate electrode formed on a pixel region of a substrate; a gate insulating film formed on the gate electrode; a semiconductor layer formed on the gate insulating film to overlap the gate electrode; a source electrode and a drain electrode overlapping the semiconductor layer; and a data insulating film formed on the source electrode and the drain electrode, wherein part of a contact hole formed in the data insulating film may overlap the channel region.
[0013] According to another aspect of the present disclosure, there is provided a liquid crystal display including: an insulating substrate; gate wiring formed on the insulating substrate and including a gate line and a gate electrode; a semiconductor pattern; data wiring including a data line, a source electrode, and a drain electrode which is separated from the source electrode; a passivation film formed on the data wiring and made of an organic material; and a contact hole formed through the passivation film and exposing a sidewall of the drain electrode so that connection to the pixel-electrode may include connection to the sidewall of the drain electrode. Other aspects will become clearer from the below detailed description.
BRIEF DESCRIPTION OF THE DRAWINGS
[0014] The above and other aspects and features of the present disclosure of invention will become more apparent by describing in detail exemplary embodiments thereof with reference to the attached drawings, in which:
[0015] FIG. 1 is a plan view of a thin-film transistor (TFT) substrate according to a first exemplary embodiment of the present disclosure;
[0016] FIG. 2A is a cross-sectional view of the TFT substrate taken along the line I-I′ of FIG. 1 ;
[0017] FIG. 2B is an enlarged view of a portion ‘A’ in FIG. 1 ;
[0018] FIGS. 3 through 11 are cross-sectional views sequentially showing processes included in a method of fabricating a TFT substrate according to a second exemplary embodiment;
[0019] FIG. 12 is a cross-sectional view showing the relationship between the TFT substrate according to the first exemplary embodiment and an upper substrate that faces the TFT substrate;
[0020] FIG. 13 is a plan view of a TFT substrate according to a modified example of the first exemplary embodiment;
[0021] FIG. 14A is a cross-sectional view of the TFT substrate taken along the line II-II′ of FIG. 13 ;
[0022] FIG. 14B is an enlarged view of a portion ‘B’ in FIG. 13 ;
[0023] FIG. 15 is a plan view of a TFT substrate according to a third exemplary embodiment;
[0024] FIG. 16A is a cross-sectional view of the TFT substrate taken along the line III-III′ of FIG. 15 ;
[0025] FIG. 16B is an enlarged view of a portion ‘C’ in FIG. 15 ;
[0026] FIGS. 17 and 18 are cross-sectional views for explaining a method of fabricating a TFT substrate according to a fourth exemplary embodiment;
[0027] FIG. 19 is a cross-sectional view showing the relationship between the TFT substrate according to the third exemplary embodiment and an upper substrate that faces the TFT substrate;
[0028] FIG. 20 is a plan view of a TFT substrate according to a modified example of the third exemplary embodiment;
[0029] FIG. 21A is a cross-sectional view of the TFT substrate taken along the line IV-IV′ of FIG. 20 ;
[0030] FIG. 21B is an enlarged view of a portion ‘D’ in FIG. 20 ;
[0031] FIG. 22 is a layout diagram of a display device according to a fifth exemplary embodiment;
[0032] FIG. 23 is a cross-sectional view of the display device taken along the line V-V′ of FIG. 22 ;
[0033] FIG. 24 is a cross-sectional view of the display device taken along the line VI-VI′ of FIG. 22 ; and
[0034] FIGS. 25A and 25B are enlarged views of a portion ‘E’ in FIG. 22 .
DETAILED DESCRIPTION
[0035] Advantages and features of devices formed in accordance with the present disclosure and methods of accomplishing the same may be understood more readily by reference to the following detailed description of exemplary embodiments and the accompanying drawings. The present teachings may, however, be embodied in many different forms and should not be construed as being limited to the exemplary embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete and will fully convey the concepts of the present teachings to those skilled in the relevant art. In some embodiments, well-known processing processes, well-known structures, and well-known technologies will not be specifically described in order to avoid ambiguous interpretations of the present teachings. Like reference numerals generally refer to like elements throughout the specification.
[0036] Spatially relative terms, such as “below,” “beneath,” “lower,” “above,” “upper,” and the like, may be used herein for ease of description to describe one device or element's relationship to another device(s) or element(s) as illustrated in the drawings. It will be understood that the spatially relative terms are intended to encompass different orientations of the device in use or operation in addition to the orientation depicted in the drawings. For example, if the device in the figures is turned over, elements described as “below” or “beneath” other elements or features would then be oriented “above” the other elements or features. Thus, the exemplary term “below” can encompass both an orientation of above and below. The device may be otherwise oriented and the spatially relative descriptors used herein interpreted accordingly.
[0037] The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the disclosure. As used herein, the singular forms “a”, “an” and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms “comprises” and/or “comprising,” when used in this specification, specify the presence of stated components, steps, operations, and/or elements, but do not preclude the presence or addition of one or more other components, steps, operations, elements, and/or groups thereof.
[0038] Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this disclosure pertains. It will be further understood that terms, such as those defined in commonly used dictionaries, should be interpreted as having a meaning that is consistent with their meaning in the context of the relevant art and will not be interpreted in an idealized or overly formal sense unless expressly so defined herein.
[0039] Hereinafter, a TFT substrate according to a first exemplary embodiment will be described in detail with reference to FIGS. 1 through 2B . FIG. 1 is a plan view of the TFT substrate according to the first exemplary embodiment. FIG. 2A is a cross-sectional view of the TFT substrate taken along the line I-I′ of FIG. 1 . FIG. 2B is an enlarged view of a portion ‘A’ in FIG. 1 .
[0040] Referring to FIGS. 1 through 2B , the TFT substrate includes various devices, such as thin-film transistors, which are formed on an insulating substrate 10 . The insulating substrate 10 may be a light-passing one such as made of glass, including a soda lime glass or a boro silicate glass, or of a plastic.
[0041] Gate wiring, which delivers gate signals, is formed on the insulating substrate 10 . The gate wiring includes a gate line 22 which extends in a first direction, for example, a horizontal direction, and a gate electrode 24 which integrally protrudes from the gate line 22 and is included in a thin-film transistor. In the first exemplary embodiment, the case where just one gate line 22 extends through each unit pixel region of a given row is described. However, two gate lines may also be formed in each unit pixel region to transmit gate signals to different subpixels. In this case, two gate electrodes may also be formed in each pixel region to be adjacent respectively to data lines on both sides of that pixel which contains plural subpixels (or plural pixel-electrodes).
[0042] In the first exemplary embodiment, each pixel region may be a bound region having its boundaries formed by adjacent gate lines 22 and adjacent data lines 56 intersecting therewith.
[0043] A charge storage line (not shown), which delivers a common voltage to a charge storage electrode, may also be formed on the insulating substrate 10 in a layer level the same as that of the gate wirings. The storage line may extend in the horizontal direction to be substantially parallel to the gate line 22 .
[0044] The signal conveying wirings (e.g., the gate lines 22 and their integrally protruding gate electrodes 24 , the storage lines, etc.) may be made of an aluminum (Al)-based metal, such as aluminum and/or an aluminum alloy, of a silver (Ag)-based metal, such as silver and a silver alloy, of a copper (Cu)-based metal such as copper and a copper alloy, of a molybdenum (Mo)-based metal such as molybdenum and a molybdenum alloy, of a chromium (Cr), or titanium (Ti) and/or tantalum (Ta) based metal.
[0045] In addition, the signal conveying wirings may have multi-film structures composed of two or more conductive films (not shown) with different physical characteristics. One of the two conductive films may be made of metal with relatively low resistivity, such as an aluminum-based metal, silver-based metal or copper-based metal, in order to reduce a signal delay or a voltage drop of the signal conveying wiring. The other one of the conductive films may be made of a different material, in particular, a material having superior contact characteristics (e.g., ohmic contact characteristics) with zinc oxide (ZnO), indium tin oxide (ITO) and indium zinc oxide (IZO), such as molybdenum-based metal, chromium, titanium, or tantalum. Examples of multi-film structures include a chromium lower film and an aluminum upper film or an aluminum lower film and a molybdenum upper film. However, the present teachings are not limited thereto. The signal wirings may be made of various other metals and conductors (e.g., including light-passing conductors).
[0046] A gate insulating film 30 is formed on the insulating substrate 10 , the gate wiring, and the storage line. The gate insulating film 30 may be made of a silicon oxide (SiOx) and/or a silicon nitride (SiNx) or a silicon oxynitride (SiOxNy).
[0047] A semiconductor layer 42 , which is formed of hydrogenated amorphous silicon or polycrystalline silicon, is disposed on the gate insulating film 30 . The semiconductor layer 42 may have portions of various shapes. For example, the semiconductor layer portion 42 may be an island shape or may be formed as a linearly region. In the first exemplary embodiment, the semiconductor layer portion 40 is an island. The semiconductor layer portion 42 overlaps the area of the gate electrode 24 .
[0048] Ohmic contact layer portions 44 and 45 formed of a contact enhancing material such as silicide or n+ hydrogenated amorphous silicon doped with n-type impurities in high concentration, may be disposed on the semiconductor layer 42 . That is, a pair of the ohmic contact layer portions 44 and 45 may be formed on the semiconductor layer portion 42 .
[0049] Signal carrying wirings may be formed on the ohmic contact layer portions 44 and 45 and the gate insulating film 30 .
[0050] The signal carrying wirings include the data line 56 , a source electrode 52 which branches off integrally from the data line 56 , and a drain electrode 54 which is shaped like an island and is separated from the source electrode 52 by a predetermined gap (channel gap) to thereby face the source electrode 52 .
[0051] The data line 56 generally extends in a vertical direction, crosses the gate line 22 and the storage line, and delivers a predetermined data voltage for selective application to the pixel-electrode of the pixel unit.
[0052] The source electrode 52 branches off integrally from the data line 56 toward the drain electrode 54 . A data line contacting terminal end (not shown) is formed at an end of the data line 56 and receives a data signal from another layer or an external source to transmit the data signal to the data line 56 .
[0053] The data wiring may be formed of refractory metal such as chromium, molybdenum-based metal, tantalum, and titanium. In addition, the data wiring may have a multi-film structure composed of a lower film (not shown), which is formed of refractory metal, and an upper film (not shown), which is formed of a material with low resistivity and is disposed on the lower film. Examples of multi-film structures include a chromium lower film and an aluminum upper film or an aluminum lower film and a molybdenum upper film. Alternatively, the multi-film structure may be a three-film structure having molybdenum-aluminum-molybdenum films.
[0054] The source electrode 52 overlaps at least part of the semiconductor layer 42 . In addition, the drain electrode 54 faces the source electrode 52 and overlaps at least another part of the semiconductor layer 42 .
[0055] Referring to the magnified view in FIG. 2B , a gate-controlled semiconductive first region of the semiconductor layer 42 , which region is between the source electrode 52 and one side (left side in FIG. 2A ) of the drain electrode 54 , is defined as a first channel region CH_ 1 . In the first channel region CH_ 1 , a conductive channel through which electric charges can move, may be formed between the source electrode 52 and the drain electrode 54 when a turn-on gate voltage (V gON ) is applied to the gate electrode 24 and an appropriate data voltage is applied to the source electrode 52 . The thus formed, conductive channel may allow electric current to flow from the source electrode 52 to the drain electrode 54 so as to thereby charge the pixel-electrode to a desired potential level.
[0056] In one embodiment, a width W 1 or diameter R 1 of the drain electrode 54 may be 6 μm or less. This width W 1 may be partially overlapped by a bottom portion of a drain contact hole 84 . If in this embodiment the width W 1 (or diameter R 1 ) of the drain electrode 54 is made greater than the 6 μm dimension, a corresponding aperture ratio of the pixel unit may be disadvantageously reduced. In this case, if the aperture ratio is reduced, the intensity of light emitted from light sources (not shown) in a backlight assembly (not shown) must be increased in order to secure a desired or standard luminance level out of the top side of the LCD. However, such an intensity increase may disadvantageously increase the overall power consumption of a liquid crystal display (LCD). Thus, the width W 1 or diameter R 1 of the drain electrode 54 should be 6 μm or less in this embodiment in order to prevent the undesired increase in the overall power consumption of the LCD.
[0057] The ohmic contact layer portions 44 and 45 are interposed between the semiconductor layer portion 42 thereunder and the source and drain electrodes 52 and 54 thereon to establish ohmic connections and reduce contact resistance between them.
[0058] A channel passivation layer 61 is formed in the region between the source electrode 52 and the drain electrode 54 . The channel passivation layer 61 may be made of an inorganic matter such as SiNx and/or SiOx and/or SiOxNy. The channel passivation layer 61 protects exposed top surface portions of the semiconductor layer 42 .
[0059] The channel passivation layer 61 is pre-patterned such that it does not cover top surfaces of the source electrode 52 and the drain electrode 54 . Accordingly, at least the full top surface area of the drain electrode is available for contact therewith by way of a to-be formed, drain contact hole. (In one embodiment described below, sidewalls of the drain electrode are also available for contact therewith by way of a to-be formed, drain contact hole.) Because the channel passivation layer 61 is pre-patterned, when the drain electrode contacting through hole 84 is later formed through a data insulating film 80 (which will be described later) there is no need to first selectively etch through the passivation layer 61 to expose the drain electrode 54 . Thus mass production fabrication is greatly simplified. A method for forming the pre-patterned channel passivation layer 61 will be detailed below (for example in reference to FIG. 8 ).
[0060] One of red, green, and blue color filters 70 is formed on each pixel region defined by the intersection of the gate line 22 and the data line 56 . (Other color filters, e.g., white, cyan, etc. may also be used.)
[0061] Each of the color filters 70 passes light in its respectively predetermined and different wavelengths range. The color filters 70 may be arranged for example in a stripe, mosaic, or delta pattern.
[0062] The color filters 70 may be made of an organic material having photosensitivity, such as photoresist. The color filters 70 may be formed to a uniform thickness or formed in a stepped manner to have a predetermined step height. Each of the color filters 70 may be made of a red organic material which primarily passes light of a red wavelength, a blue organic material which primarily passes light of a blue wavelength, or a green organic material which primarily passes light of a green wavelength.
[0063] The data insulating film 80 (also planarization film 80 herein) is formed on the source electrode 52 , the drain electrode 54 , the passivation layer 61 , and the color filters 70 . The data insulating film 80 may be made of an organic photoresist material having superior planarization characteristics. Alternatively, the data insulating film 80 may be made of SiNx. The passivation layer 61 and the data insulating film 80 may be made of different materials. For example, when the passivation layer 61 is made of SiOx, the data insulating film 80 may be made of an organic material or SiNx. The data insulating film 80 may be formed to a thickness of approximately 3 μm to fully cover the color filters 70 so that the color filters 70 do not cause changes of distance between the overlying pixel-electrode 90 and a common electrode in the other substrate. Since the data insulating film 80 fully covers the color filters 70 , it can have superior planarization characteristics.
[0064] The contact hole 84 is formed through the data insulating film 80 so as to extend to underlying portions of the drain electrode 54 and of the passivation layer 61 . The pixel electrode 90 , which will be described more fully later, and the drain electrode 54 are electrically connected to each other by the contact hole 84 . Accordingly, a data signal can be transmitted to the pixel electrode 90 from the data line 56 by passing through the drain electrode 54 of the corresponding TFT. Here, part of the contact hole 84 may overlap the channel region (e.g., CH_ 2 ) but it is isolated from the overlapped portion of the channel region by the passivation layer 61 .
[0065] As the thickness of the data insulating film 80 increases, a width of the contact hole 84 also tends to increase, thereby increasing the likelihood of an overlay miss between the drain electrode 54 and the bottom of the tapered contact hole 84 . If the passivation layer 61 were not present, such an overlay miss may result in an internal short circuit, that is, may cause the pixel electrode 90 to directly connect to the semiconductor layer 42 such that a predetermined channel gap is made too short or shorted out completely and the TFT fails to operate as intended. To reduce the possibility of such internal short circuits, the area of the drain electrode 54 is typically increased in accordance with an increase in the width of the bottom of the contact hole 80 . However, an increase in the area of the drain electrode 54 may result in an increase in a value of a parasitic capacitance Cgd between the drain ( 54 ) and the gate ( 24 ) nodes of the TFT, thereby increasing an undesirable kickback voltage of the TFT. (The kickback voltage tends to increase when the Cgd capacitance increases.) In addition, an increase in the area of the drain electrode 54 may result in a reduction in the aperture ratio. Consequently, image quality of a display device may deteriorate.
[0066] According to the present disclosure however, the passivation layer 61 is formed in the region between the source electrode 52 and the drain electrode 54 above the semiconductor layer 42 . Thus, even when an overlay miss occurs; as is shown schematically in FIG. 2A , between the bottom of the contact hole 84 and the exposed upper surface of the drain electrode 54 , the misalignment may not cause the internal short circuit conditions described above. That is, the passivation layer 61 is present to prevent the drain-contacting portion of the pixel electrode 90 from directly contacting the semiconductor layer 42 to thus shorten the effective length of the TFT channel. Note that although the plan view of FIG. 2B makes it appear as if the channel length is being shortened in region CH_ 1 , this is not the case because the bottom of the drain contact hole is spaced apart from the channel surface by the thickness of the passivation layer 61 . Therefore, according to the present disclosure, even when the width of the contact hole 84 increases in accordance with the increase in the thickness of the data insulating film 80 , there is no need to correspondingly increase the area of the drain electrode 54 to accommodate for possible misalignment of the bottom of the contact hole. Accordingly, the value of the parasitic capacitance Cgd between the drain node ( 54 ) and the gate node ( 24 ) does not significantly increase. Consequently, an undesirable increase in the kickback voltage and an undesirable reduction in the aperture ratio can be substantially prevented.
[0067] After the drain contact hole 84 is formed, for example as a tapered hole, the pixel electrode 90 is formed on the data insulating film 80 . The pixel electrode 90 may be formed of a transparent conductor, such as ITO or IZO, or of a reflective conductor such as aluminum depending on whether the LCD is a light through-passing kind or a light reflecting kind. The pixel electrode 90 is electrically connected to the drain electrode 54 by way of a portion of the deposited pixel-electrode material extending through the contact hole 84 to make at least partially overlapping contact with the upper surface of the drain electrode 54 . The drain contacting portion of the pixel electrode 90 may be disposed on/above the drain electrode 54 and on the adjacent part of the passivation layer 61 . That is, the passivation layer 61 is interposed between the pixel electrode 90 and the semiconductor layer 42 . Accordingly, even when an overlay miss occurs between the bottom of the contact hole 84 and the drain electrode 54 , this misalignment does not cause the above-described internal short circuit phenomenon to occur (e.g., effective shortening of the TFT channel length) due to the presence of the short-preventing passivation layer 61 .
[0068] A column spacer (not shown) may be formed on the TFT substrate. The column spacer may be used to maintain a substantially constant cell gap between an upper substrate and the TFT substrate.
[0069] Hereinafter, a method of fabricating a TFT substrate according to a second exemplary embodiment will be described in detail with reference to FIGS. 3 through 12 . FIGS. 3 through 11 are cross-sectional views sequentially showing processes included in the method of fabricating a TFT substrate according to the second exemplary embodiment. For simplicity, elements having the same functions as those shown in the drawings for the first exemplary embodiment are indicated by like reference numerals, and thus their description will be omitted or simplified.
[0070] Referring to FIG. 3 , a gate layer wiring pattern 22 / 24 , which includes a patterned gate line 22 and a patterned gate electrode 24 , and a patterned storage line (not shown) are formed on a light-passing insulating substrate 10 .
[0071] The gate wiring layer may be formed by, e.g., blanket sputtering of the appropriate conductive materials. Then, the deposited gate wiring layer may be patterned by a wet-etching process or a dry-etching process. In the wet-etching process, an etchant, such as phosphoric acid, nitric acid or acetic acid, may be used in combination with an etchant resistant mask. In the dry-etching process, a fluorine-based etching gas, such as Cl 2 or BCl 3 , may be used in combination with a plasma resistant mask whose pattern is defined with use of appropriate photolithography.
[0072] Referring to FIG. 4 , next a gate insulating film 30 is formed on the insulating substrate 10 , the patterned gate wiring layer 22 / 24 . The gate insulating film 30 may be blanket formed by plasma enhanced chemical vapor deposition (PECVD) or reactive sputtering.
[0073] Referring to FIGS. 5 and 6 , next a hydrogenated amorphous silicon layer 40 , an n+ hydrogenated amorphous silicon layer 41 that is doped with n-type impurities in high concentration, and a conductive layer 50 are formed by stacking of respective conductive materials for forming the data wring layer are sequentially disposed on the gate insulating film 30 . The hydrogenated amorphous silicon layer 40 and the n+ hydrogenated amorphous silicon layer 41 doped with n-type impurities in high concentration may be formed by PECVD or chemical vapor deposition (CVD). In addition, the conductive layer 50 may be formed by sputtering.
[0074] Next (between FIGS. 5 and 6 ), photoresist is coated on the conductive layer 50 and then developed to form photoresist patterns (not shown) for patterning in one step the hydrogenated amorphous silicon layer 40 , the n+ hydrogenated amorphous silicon layer 41 doped with n-type impurities in high concentration, and the conductive layer 50 . Then, the hydrogenated amorphous silicon layer 40 , the n+ hydrogenated amorphous silicon layer 41 doped with n-type impurities in high concentration, and the conductive layer 50 are etched in one step using the photoresist patterns (not shown) as a mask, thereby forming a semiconductor layer 42 , an ohmic contact layer pattern 43 , and a conductive layer pattern 51 , respectively as shown in FIG. 6 .
[0075] Thereafter, new photoresist patterns 102 and 103 are formed on the conductive layer pattern 51 as shown in FIG. 6 for the purpose of next patterning the ohmic contact layer pattern 43 and the conductive layer pattern 51 . The left and right side photoresist pattern portions 102 are used to pattern a corresponding portion of the conductive layer pattern 51 into a semi-circular shaped source electrode 52 (see FIG. 2B ). On the other hand, the middle photoresist pattern 103 is used to pattern another portion of the conductive layer pattern 51 into the centrally located drain electrode 54 . Although not shown in FIG. 6 , the outer photoresist pattern portions 102 extend to also cover a leg portion of the Y-shaped source electrode 52 of FIG. 2B and portions 102 yet further extend to continuously surround the area where the color filter will be formed. The photoresist patterns 102 (and 103 ) are formed to a height sufficient to allow them to also serve as barrier ribs for containing color filter resin in an inkjet method that is used to later form the color filters 70 as will be described later. In addition, the photoresist patterns 102 and 103 may be inversely tapered (e.g., shaped as downward pointing frusto triangles in the cross section view) such that they can be easily exfoliated in a lift-off process which will be described later.
[0076] Referring next to FIG. 7 , the conductive layer pattern 51 is patterned using the photoresist pattern 102 and 103 as an etch mask, thereby forming the source electrode 52 and the drain electrode 54 . Here, the drain electrode 54 may be formed to a width (indicated by reference character ‘W 1 ’ in FIG. 2A ) or diameter (indicated by reference character ‘R 1 ’ in FIG. 2B ) of 6 μm or less.
[0077] The ohmic contact layer pattern 43 is also patterned at the same time as the conductive layer pattern 51 . As a result, a patterned ohmic contact layer 44 , which is overlapped by a bottom surface of the source electrode 52 , and a patterned ohmic contact layer 45 , which is overlapped by a bottom surface of the drain electrode 54 , are formed. Since the source electrode 52 and the drain electrode 54 are formed above the semiconductor layer 42 and in spaced apart relation, a channel region CH_ 1 is formed in a region of the semiconductor layer 42 which is not overlapped by the source electrode 52 and the drain electrode 54 .
[0078] Referring to FIG. 8 , while the photoresist patterns 102 and 103 are still in place, an insulating material is blanket deposited on all up facing and exposed surfaces of the resultant structure of FIG. 7 for example by PECVD or CVD deposition, thereby forming passivation layer regions 61 and 63 that do not overlap the source and drain electrodes, 52 and 54 . The deposited insulating material may be SiO2 or SiNx. Due to the photoresist patterns 102 and 103 still being formed on the upward facing tops of the source electrode 52 and the drain electrode 54 , the deposited insulating material that is stacked on upward facing top surfaces is not directly stacked on top surfaces of the source electrode 52 and the drain electrode 54 due to the photoresist patterns 102 and 103 . Instead, the insulating material is stacked on the top surfaces of the photoresist patterns 102 and 103 as an insulating material layers 62 and 64 . That is, the passivation layer regions 61 and 63 do not extend to directly cover the top surfaces of the source electrode 52 and the drain electrode 54 . The full top surface area of the drain electrode 54 as well as optionally part of the sidewall surface area of the drain electrode 54 are left available for later contact with the pixel-electrode after the drain contact hole is formed ( 84 in FIG. 11 ).
[0079] When the photoresist patterns 102 and 103 are inversely tapered as shown in FIG. 8 , the blanket deposited insulating material is not stacked on the down facing side walls of the photoresist patterns 102 and 103 , and there is a break in continuity between passivation layer regions 61 and 63 , thereby making it easy to later exfoliate the photoresist patterns 102 and 103 from the structure.
[0080] Referring to FIG. 9 , next drops of a colored organic material are selectively deposited, for example by ink jet spraying over the resultant structure of FIG. 8 by using, e.g., an inkjet printing device (not shown). In this inkjet deposition method, the still present, photoresist patterns 102 and 103 are used as barrier ribs for containing the liquid colored organic material before it is hardened. In other words, each respective pixel region is surrounded by the photoresist patterns 102 and 103 when it is sprayed and it is filled with the colored organic material. There is no need to spray the colored organic material over the region between the source electrode 52 and the drain electrode 54 in which no image is displayed.
[0081] Specifically, to form the color filters 70 using an inkjet printing device, a red organic liquid material is sprayed over and thus fills a pixel region surrounded by the photoresist patterns 102 and 103 while the inkjet printing device is moved in a predetermined direction over the pixel region that is predetermined to be a red pixel unit. In the case of an RGB striped pattern being used, the red organic material is sprayed over one in every three pixel regions arranged in the direction in which the inkjet printing device is moved. Then, green and blue organic materials are also sprayed over the other pixel regions in the same way. If the inkjet printing device can spray all of the three colored organic materials, it may move over pixel regions while alternately spraying the three colored organic materials.
[0082] A colored organic material when it is sprayed is a hardenable liquid material. However, since the sprayed colored organic material has a sufficient amount of viscosity and it is surrounded by the photoresist pattern 102 , it can stably remain within a pixel region. In the inkjet method, the photoresist patterns 102 and 103 , which are formed to pattern the data wiring and the ohmic contact layers 44 and 45 , can be used as ink jet barrier ribs. Thus, a process for separately forming barrier ribs can be omitted, which, in turn, simplifies the entire fabrication process.
[0083] The liquid, colored organic material plus solvent which is filled between the photoresist patterns 102 and 103 is dried and solidified for example by heat treatment or ultraviolet radiation. As a result, one of the red, green and blue filters 70 is formed in each pixel region.
[0084] Referring to FIG. 10 , the photoresist patterns 102 and 103 formed on the source electrode 52 and the drain electrode 54 are removed (exfoliated). Here, the insulating material layers 62 and 64 on the top surfaces of the photoresist patterns 102 and 103 are lifted off and thus removed. Accordingly, the passivation layers 61 and 63 no longer cover the top surfaces of the source electrode 52 and the drain electrode 54 . Thus, the top surfaces of the source electrode 52 and the drain electrode 54 are exposed. In one embodiment, a top surface cleaning process may be used to assuredly remove left behind micro remnants of the photoresist material of patterns 102 and 103 . In other words, the effect that can be achieved when the passivation layer regions 61 and 63 are formed, that the tops of the source electrode 52 and the drain electrode 54 are not covered by the passivation layer material ( 61 , 63 ). Since no additional photoresist process is now needed for selectively exposing the top surfaces of the source electrode 52 and the drain electrode 54 , the entire fabrication process can be simplified.
[0085] Referring to FIG. 11 , a data insulating film 80 is formed on the source electrode 52 , the drain electrode 54 , the color filters 70 , and the passivation layer 61 . The data insulating film 80 may be made of an organic material to have superior planarization characteristics. Alternatively or additionally, the data insulating film 80 may be made of SiNx. Planarization of film 80 by CMP or the like may be carried out before and/or after the drain contact hole 84 is formed. After the data insulating film 80 is deposited, the drain contact hole 84 is formed in the data insulating film 80 to expose at least part of the drain electrode 54 . Here, an overlay miss may occur between the bottom of the contact hole 84 (optionally down tapered hole 84 ) and the drain electrode 54 , thereby causing the bottom of the contact hole 84 to expose part of the passivation layer 61 between the source and drain electrodes. That is, part of the contact hole 84 may overlap the top of the passivation layer 61 that covers the channel region CH_ 1 .
[0086] According to the present disclosure, even when an overlay miss occurs, it is not accompanied by significant problems, as described above because the target missing portion of the downward extending pixel-electrode is vertically spaced apart from the semiconductor surface by the thickness of the passivation layer 61 .
[0087] Referring back to FIG. 2 , a transparent conductive material, such as ITO or IZO, is stacked on the data insulating film 80 by sputtering and then patterned to form a pixel electrode 90 which is electrically connected to the drain electrode 54 by passage through the contact hole 84 .
[0088] FIG. 12 is a cross-sectional view showing the relationship between the TFT substrate according to the first exemplary embodiment and the upper substrate that faces the TFT substrate. Referring to FIG. 12 , the upper substrate includes a base substrate 200 , a black matrix 210 , an overcoat layer 220 , and a common electrode 230 .
[0089] The black matrix 210 may be made of metal (metal oxide), such as chromium and chromium oxide, or organic black resist. The black matrix 210 may overlap a thin-film transistor formed on the TFT substrate. Accordingly, the black matrix 210 can prevent leakage of light, thereby improving image quality. According to the present disclosure, the contact hole 84 is formed in a region overlapped by the black matrix 210 . The size of the black matrix 210 does not need to be increased when the thickness of the planarization layer 80 is increased because the present design can tolerate misalignment between the drain contact hole 84 and the drain electrode 54 . Thus, an aperture ratio of the device need not be decreased when planarization thickness is increased, where decrease of the aperture ratio disadvantageously reduces image quality and/or increases backlighting power consumption.
[0090] Hereinafter, a TFT substrate according to a modified example of the first exemplary embodiment will be described with reference to FIGS. 13 through 14B . FIG. 13 is a plan view of the TFT substrate according to the modified example of the first exemplary embodiment of the present invention. FIG. 14A is a cross-sectional view of the TFT substrate taken along the line II-II′ of FIG. 13 . FIG. 14B is an enlarged view of a portion ‘B’ in FIG. 13 . For simplicity, elements having the same functions as those shown in the drawings for the first exemplary embodiment are indicated by like reference numerals, and thus their description will be omitted or simplified.
[0091] Referring to FIG. 13 , a source electrode 55 according to the modified example of the first exemplary embodiment fully surrounds the drain electrode 54 . Accordingly, a thin-film transistor according to the modified example of the first exemplary embodiment has a greater effective channel width than a thin-film transistor according to the first exemplary embodiment and thus can exhibit lower source to drain resistance when turned on and can provide better operation performance.
[0092] A method of fabricating a TFT substrate according to a modified example of the second exemplary embodiment is substantially identical to the method of fabricating a TFT substrate according to the second exemplary embodiment except that a source electrode 55 is formed to fully surround the drain electrode 54 , and thus a detailed description thereof will not be repeated.
[0093] Hereinafter, a TFT substrate according to a third exemplary embodiment of the present invention will be described in detail with reference to FIGS. 15 through 16B . FIG. 15 is a plan view of the TFT substrate according to the third exemplary embodiment of the present invention. FIG. 16A is a cross-sectional view of the TFT substrate taken along the line III-III′ of FIG. 15 . FIG. 16B is an enlarged view of a portion ‘C’ in FIG. 15 . For simplicity, elements having the same functions as those shown in the drawings for the first exemplary embodiment are indicated by like reference numerals, and thus their description will be omitted or simplified. The TFT substrate according to the third exemplary embodiment is identical to the TFT substrate according to the first exemplary embodiment except for the following features.
[0094] In the TFT substrate according to the third exemplary embodiment, a passivation layer 65 covers a source electrode 52 and a drain electrode 54 . In addition, a contact hole 84 is formed in the passivation layer 65 and a data insulating film 80 . Here, the contact hole 84 overlaps a channel region CH_ 3 . Accordingly, the channel region CH_ 3 of a semiconductor layer 42 is exposed. Thus, part of a pixel electrode 90 may extend to directly contact the semiconductor layer 42 . At the same time the pixel electrode 90 of this embodiment contacts the full sidewall of drain electrode 54 .
[0095] Hereinafter, a method of fabricating a TFT substrate according to a fourth exemplary embodiment will be described with reference to FIGS. 17 through 19 . FIGS. 17 and 18 are cross-sectional views for explaining the method of fabricating a TFT substrate according to the fourth exemplary embodiment of the present invention. For simplicity, elements having the same functions as those shown in the drawings for the first exemplary embodiment are indicated by like reference numerals, and thus their description will be omitted or simplified. The method of fabricating a TFT substrate according to the fourth exemplary embodiment is identical to the method of fabricating a TFT substrate according to the second exemplary embodiment except for the following features.
[0096] Referring to FIG. 17 , a source electrode 52 and a drain electrode 54 are formed on a substrate, and an insulating material is stacked on the substrate by PECVD or CVD, thereby forming a passivation film 60 . Here, the insulating material may be SiO2 or SiNx.
[0097] Next, a data insulating film 80 is formed on the resultant structure of FIG. 17 . After the data insulating film 80 is formed, the data insulating film 80 and the passivation film 60 are patterned to form a contact hole 84 . Here, part of the contact hole 84 may overlap a channel region CH_ 3 of a semiconductor layer 42 . Unlike in the second exemplary embodiment, in the fourth exemplary embodiment, the passivation film 60 ′ is patterned so that the later formed contact hole 84 extends through the passivation film 60 ′ to expose part of the semiconductor layer 42 . In other words, the passivation film 60 ′ is intentionally patterned so that part of the semiconductor layer 42 is exposed. The passivation film 60 ′ having the contact hole 84 ′ formed therethrough will be referred to as a passivation layer 65 .
[0098] When the contact hole 84 ′ is formed, the passivation film 60 on the semiconductor layer 42 is etched. Thus, when the passivation film 60 is etched to form the contact hole 84 , it may have a different etch selectivity from the semiconductor layer 42 in order to prevent the semiconductor layer 42 from being etched. In addition, when the data insulating film 80 is etched to form the contact hole 84 , it may have a different etch selectivity from the semiconductor layer 42 in order to prevent the semiconductor layer 42 from being etched.
[0099] FIG. 19 is a cross-sectional view showing the relationship between the TFT substrate according to the third exemplary embodiment and an upper substrate that faces the TFT substrate. Features shown in FIG. 19 are substantially identical to those shown in FIG. 12 except that the TFT substrate according to the third exemplary embodiment is applied, and thus a detailed description thereof will not be repeated.
[0100] Hereinafter, a TFT substrate according to a modified example of the third exemplary embodiment of the present invention will be described with reference to FIGS. 20 through 21B . FIG. 20 is a plan view of the TFT substrate according to the modified example of the third exemplary embodiment. FIG. 21A is a cross-sectional view of the TFT substrate taken along the line IV-IV′ of FIG. 20 . FIG. 21B is an enlarged view of a portion ‘D’ in FIG. 20 . For simplicity, elements having the same functions as those shown in the drawings for the third exemplary embodiment are indicated by like reference numerals, and thus their description will be omitted or simplified.
[0101] Referring to FIG. 20 , a source electrode 55 according to the modified example of the third exemplary embodiment fully surrounds the drain electrode 54 . Accordingly, a thin-film transistor according to the modified example of the third exemplary embodiment has a greater channel width than a thin-film transistor according to the third exemplary embodiment and thus exhibits better operation performance.
[0102] A method of fabricating a TFT substrate according to a modified example of the fourth exemplary embodiment of the present invention is substantially identical to the method of fabricating a TFT substrate according to the fourth exemplary embodiment except that a source electrode 55 is formed to fully surround the drain electrode 54 , and thus a detailed description thereof will not be repeated.
[0103] Hereinafter, a display device 1 according to a fifth exemplary embodiment will be described in detail with reference to FIGS. 22 through 25B . FIG. 22 is a layout diagram of the display device 1 according to the fifth exemplary embodiment. FIG. 23 is a cross-sectional view of the display device 1 taken along the line V-V′ of FIG. 22 . FIG. 24 is a cross-sectional view of the display device 1 taken along the line VI-VI′ of FIG. 22 . FIGS. 25A and 25B are enlarged views of a portion ‘E’ in FIG. 22 .
[0104] Referring to FIGS. 22 through 24 , the display device 1 according to the fifth exemplary embodiment includes a first display substrate 100 , a second display substrate 200 , a liquid crystal layer 300 , and a colored column spacer 501 .
[0105] The first display substrate 100 includes an insulating substrate 10 , gate wiring, a gate insulating film 30 , a semiconductor pattern 42 , ohmic contact patterns 46 and 47 , data wiring, a passivation film 70 , a contact hole 77 , and a pixel electrode 82 .
[0106] The insulating substrate 10 may be made of a light-transmissive and heat-resistant material such as transparent glass or plastic.
[0107] The gate wiring is formed on the insulating substrate 10 in a first direction, for example, a horizontal direction. The gate wiring includes a plurality of gate lines 22 which deliver gate signals, a gate electrode 26 which integrally protrudes from each of the gate lines 22 , and a gate line end terminal (not shown) which is formed at an end of each of the gate lines 22 and receives a gate signal from another layer or an external source to transmit the gate signal to each of the gate lines 22 . The gate electrode 24 , a source electrode 65 and a drain electrode 66 , which will be described later, form three terminals of a thin-film transistor.
[0108] The gate wiring (i.e., the gate lines 22 and the gate electrode 24 ) may be made of an aluminum (Al)-based metal, such as aluminum and an aluminum alloy (e.g., Al, AlNd, AlCu, etc.), silver (Ag)-based metal, such as silver and a silver alloy, copper (Cu)-based metal such as copper and a copper alloy, molybdenum (Mo)-based metal such as molybdenum and a molybdenum alloy (e.g., Mo, MoN, MoNb, etc.), chromium (Cr), titanium (Ti) or tantalum (Ta).
[0109] In addition, the gate wiring may have a multi-film structure composed of two conductive films (not shown) with different physical characteristics. One of the two conductive films may be made of metal with low resistivity, such as aluminum-based metal, silver-based metal or copper-based metal, in order to reduce a signal delay or a voltage drop of the gate wiring. The other one of the conductive films may be made of a different material, in particular, a material having superior contact characteristics with ITO and IZO, such as molybdenum-based metal, chromium, titanium, or tantalum. Examples of multi-film structures include a chromium lower film and an aluminum upper film or an aluminum lower film and a molybdenum upper film. However, the present teachings are not limited thereto. The gate wiring may be made of various other metals and conductors.
[0110] The gate insulating film 30 is formed on the gate wiring and portions of the insulating substrate 10 which are exposed by the gate wiring. The gate insulating film 30 may be made of an inorganic insulating material such as SiOx and SiNx, or may be made of an organic insulating material such as benzocyclobutene (BCB), an acrylic material, and polyimide. The gate insulating film 30 covers the gate wiring (i.e., the gate lines 22 and the gate electrode 24 ). In particular, the gate insulating film 30 is formed on the entire surface of the insulating substrate 10 , including a pixel region in which the pixel electrode 82 is formed. Here, a pixel region may be understood as a region which is defined by the gate wiring and the data wiring and through which light emitted from a backlight assembly (not shown) of the display device 1 passes.
[0111] The semiconductor pattern 42 , which is made of hydrogenated amorphous silicon, polycrystalline silicon or a conductive organic material, is formed on a portion of the gate insulating film 30 .
[0112] The semiconductor pattern 42 may have various shapes. For example, the semiconductor pattern 42 may be an island or may be formed linearly. If the semiconductor pattern 42 is shaped like an island as in the current exemplary embodiment, it may be overlapped by part of a source electrode 57 and part of a drain electrode 59 above the gate electrode 24 . The shape of the semiconductor pattern 42 may not be limited to an island.
[0113] The ohmic contact patterns 46 and 47 may be formed on the semiconductor pattern 42 . The ohmic contact patterns 46 and 47 are made of silicide, n+ hydrogenated amorphous silicon which is doped with n-type impurities in high concentration, or a material doped with p-type impurities, such as ITO. The ohmic contact patterns 46 and 47 are formed in pairs on the semiconductor pattern 42 and improve contact characteristics between the source electrode 57 and the semiconductor pattern 42 and between the drain electrode 59 and the semiconductor pattern 42 . When the contact characteristics between the source electrode 57 and the semiconductor pattern 42 and between the drain electrode 59 and the semiconductor pattern 42 are good enough, the ohmic contact patterns 46 and 47 may be omitted.
[0114] On the resultant structure including the ohmic contact patterns 55 and 56 , the data wiring, which includes a data line 56 , the source electrode 57 , the drain electrode 59 and a data line end terminal (not shown), is formed.
[0115] The data line 56 extends in a second direction, for example, a vertical direction. In addition, the data line 56 is insulated from each of the gate lines 22 and crosses each of the gate line 22 .
[0116] The source electrode 57 integrally protrudes from the data line 56 in the form of a branch and extends onto the semiconductor pattern 42 . The data line end terminal (not shown) is formed at an end of the data line 56 . The data line end terminal receives a data signal from another layer or an external source and delivers the received data signal to the data line 56 .
[0117] The source electrode 57 at least partially overlaps the semiconductor pattern 42 . The drain electrode 59 is separated from the source electrode 57 and is disposed above the semiconductor pattern 42 to face the source electrode 57 with respect to the gate electrode 24 . The semiconductor pattern 42 is exposed in the gap between the source electrode 57 and the drain electrode 59 . A thin-film transistor is a three-terminal device composed of the gate electrode 24 , the source electrode 57 , and the drain electrode 59 . In addition, a thin-film transistor is a switching device that allows electric current to flow between the source electrode 57 and the drain electrode 59 when a voltage is applied to the gate electrode 24 .
[0118] The drain electrode 59 may include a first drain electrode portion 59 _ 1 and a second drain electrode portion 59 _ 2 which extends from the first drain electrode portion 59 _ 1 toward the source electrode 57 . The first drain electrode portion 59 _ 1 may be formed as a pattern relatively wider than the second drain electrode portion 59 _ 2 . The second drain electrode portion 59 _ 2 may be formed as a bar-shaped pattern that extends from the first drain electrode portion 59 _ 1 toward the source electrode 57 .
[0119] The data wiring (i.e., the data line 56 , the source electrode 57 , and the drain electrode 59 ) may be a single film or multiple films which is/are made of one or more of Al, an Al alloy (e.g., Al, AlNd, AlCu or the like), Cr, a Cr alloy, Mo, a Mo alloy (e.g., Mo, MoN, MoNb or the like), Ta, a Ta alloy, Ti and a Ti alloy. For example, the data wiring may be made of refractory metal such as Cr, Mo-based metal, Ta and Ti. In addition, the data wiring may be formed of refractory metal such as chromium, molybdenum-based metal, tantalum, and titanium. In addition, the data wiring may have a multi-film structure composed of a lower film (not shown), which is formed of refractory metal, and an upper film (not shown) which is formed of a material with low resistivity and is disposed on the lower film. Examples of multi-film structures include a chromium lower film and an aluminum upper film and an aluminum lower film and a molybdenum upper film. Alternatively, the multi-film structure may be a three-film structure having molybdenum-aluminum-molybdenum films.
[0120] The passivation film 70 is formed on the data wiring (i.e., the data line 56 , the source electrode 57 , and the drain electrode 59 ) and exposed portions of the gate insulating film 30 . The passivation film 70 may be made of an inorganic material such as silicon nitride or silicon oxide, an organic material having photosensitivity and superior planarization characteristics, or a low-k dielectric material formed by PECVD, such as a-Si:C:O or a-Si:O:F.
[0121] The contact hole 77 , which exposes the drain electrode 59 , is formed in the passivation film 70 . The contact hole 77 exposes part of the first drain electrode portion 59 _ 1 and part of the second drain electrode portion 59 _ 2 . In addition, the contact hole 77 exposes a portion of the gate insulating film 30 which is located in a region adjacent to where the first drain electrode portion 59 _ 1 meets the second drain electrode portion 59 _ 2 . That is, since the first drain electrode portion 59 _ 1 is relatively wider than the second drain electrode portion 59 _ 2 , a portion of the gate insulating film 30 in a peripheral region of the second drain electrode portion 59 _ 2 may be exposed by the contact hole 77 .
[0122] The pixel electrode 82 is formed on the passivation film 70 which is located in a pixel region and is connected to the drain electrode 59 by the contact hole 77 . The contact hole 77 exposes a portion of the first drain electrode portion 59 _ 1 and a portion of the second drain electrode portion 59 _ 2 such that the pixel electrode 82 contacts a portion of the first drain electrode portion 59 _ 1 and a portion of the second drain electrode portion 59 _ 2 . In addition, the pixel electrode 82 may be formed in a region of the gate insulating film which is exposed by the contact hole 77 .
[0123] The pixel electrode 82 may be made of a transparent conductor, such as ITO or IZO, or a reflective conductor such as aluminum.
[0124] Although not shown in the drawings, each color filter (not shown) may be formed in a pixel region before the passivation film 70 is formed in the pixel region. Each color filter absorbs or passes light of a predetermined wavelength by using a red, green or blue pigment included therein in order to represent red, green or blue color. The color filters may represent various colors by additively mixing red, green and blue light that passed therethrough.
[0125] The second display substrate 200 will now be described below. A black matrix 220 for preventing leakage of light is formed on an insulating substrate 210 . The black matrix 220 is formed in regions other than a region facing the pixel electrode 82 , thereby defining a pixel region.
[0126] The black matrix 220 may overlap the drain electrode 59 disposed on the first display substrate 100 . That is, the black matrix 220 may overlap the first drain electrode portion 59 _ 1 and the second drain electrode portion 59 _ 2 of the drain electrode 59 . In order to minimize a reduction in the aperture ratio due to the black matrix 220 , the black matrix 220 may overlap part of the first drain electrode portion 59 _ 1 . That is, a side of the first drain electrode portion 59 _ 1 which does not meet the second drain electrode portion 59 _ 2 may not be overlapped by the black matrix 220 .
[0127] The black matrix 220 may overlap the contact hole 77 of the first display substrate 100 . That is, the contact hole 77 may be disposed in a region in which the black matrix 220 of the second display substrate 200 is formed. Thus, since the contact hole 77 is not disposed in a pixel region, the aperture ratio of the display device 1 can be increased. A width of the contact hole 77 may increase as the distance between the contact hole 77 and the semiconductor pattern 42 is reduced and may decrease as the distance between the contact hole 77 and the semiconductor pattern 42 increases.
[0128] Specifically, referring to FIG. 25A , when a contact hole 77 — a is separated from the semiconductor pattern 42 by a first gap G 1 , it may have a first aperture width W 1 . Referring to FIG. 25B , when a contact hole 77 — b is separated from the semiconductor pattern 42 by a second gap G 2 , it may have a second aperture width W 2 . Here, if the second gap G 2 is wider than the first gap G 1 , the second aperture width W 2 should be narrower than the first aperture width W 1 . If the second aperture width W 2 is substantially equal to or wider than the first aperture width W 1 , a portion of the contact hole 77 — b may be outside the region in which the black matrix 220 is formed. Accordingly, the overall aperture ratio of the display device 1 may be reduced. Therefore, if the second gap G 2 is wider than the first gap G 1 , the second aperture width W 2 should be narrower than the first aperture width W 1 . The black matrix 220 may be made of an opaque organic material or opaque metal.
[0129] Color filters (not shown) for representing colors may be formed on the insulating substrate 210 . In this case, the color filters may not be formed on the first display substrate 100 . That is, in the display device 1 according to the present invention, color filters may be formed on the first display substrate 100 or the second display substrate.
[0130] An overcoat layer 230 may be formed on the black matrix 220 in order to planarize step heights of the second display substrate 200 . The overcoat layer 240 is made of a transparent organic material, protects the color filters and the black matrix 220 , and insulates the black matrix 220 and the color filters from a common electrode 240 which will be described later.
[0131] The common electrode 240 is formed on the overcoat layer 230 . The common electrode 240 may be made of a transparent conductive material, such as ITO or IZO.
[0132] The liquid crystal layer 300 is interposed between the first display substrate 100 and the second display substrate 200 . The voltage difference between the pixel electrode 82 and the common electrode 240 determines transmittance.
[0133] A colored column spacer 501 is interposed between the first display substrate 100 and the second display substrate 200 . The colored column spacer 501 according to the fifth exemplary embodiment maintains a cell gap between the first display substrate 100 and the second display substrate 200 . The colored column spacer 501 may overlap the contact hole 77 of the first display substrate 100 . Accordingly, external light can be prevented from entering a thin-film transistor through the contact hole 77 . The colored column spacer 501 may be, e.g., black.
[0134] While teachings in accordance with the present disclosure of invention have been particularly shown and described with reference to exemplary embodiments thereof, it will be understood by those of ordinary skill in the art in light of the foregoing that various changes in form and detail may be made therein without departing from the spirit and scope of the present teachings. The exemplary embodiments should be considered in a descriptive sense only and not for purposes of limitation.
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Provided are a backlight assembly with improved heat dissipation, and a liquid crystal display (LCD) having such a backlight assembly. The backlight assembly includes: a light guide plate; a light source unit disposed on a side of the light guide plate; an intermediate housing covering an upper surface of the light source unit; and a lower housing coupled to the intermediate housing to accommodate the light guide plate and the light source unit, wherein the lower housing includes: a light source unit-fixing frame to which the light source unit is fixed, the light source unit-fixing frame contacting an inner surface of the intermediate housing; and a body portion disposed under the light guide plate and coupled to the light source unit-fixing frame.
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BACKGROUND OF THE INVENTION
Field of the Invention
The invention concerns a method and equipment for treating, and in particular, for dyeing fabric warp threads, wherein the warp threads, or warps, while in the raw (white) state, are made to pass in a single operational step through a so-called sizing bath which rigidifies the warps and making them more wear-resistant wherein the dyes to be deposited are present in as a viscous material or in a pasty state in the sizing bath. The warps so treated may then be woven and/or further dyed in a post-processing stage.
Background of the Related Methods
This known procedure incurs the following drawback. Because the warps are dyed subsequent to the making of the fabric, the finishing time is comparatively long in white weaving due to special operational steps that are incurred relating to interim storage, interim drying and the like. As a result, fabrics treated in this manner are costlier.
SUMMARY OF THE INVENTION
Accordingly, it is the object of the invention to create a method and apparatus which serves to lower these operational costs.
The novelty of the instant invention lies in the fact that untreated warps in the raw (white) state are made to pass in a single operational step through at least one bath containing the sizing substance, i.e. the size, wherein the dyes to be deposited are present as a viscous material or in a pasty state in the bath in addition to the size.
This method eliminates the necessity for subsequent dyeing at a remote third station. Instead, the warps are simultaneously treated with size and dye in a single operational step while passing through a single apparatus, i.e. in an in-line operation. Thus, the entire operational step to make dyed and sized warps is carried out in much less time than in the known procedure.
It was discovered in surprising manner that satisfactory dye deposition may be achieved in spite of maintaining the in-line speed of about 23 m/min. This is also and especially the case when the dye is present not as a dye liquor, but instead, as a viscous medium or in a pasty state.
However, the advantages of the method of the present invention are also obtained when dyeing the warps before the sizing operation at another station for multi-color weaving. Similarly, all the operational stages such as interim storage, interim drying and the like are eliminated.
Equipment with which to carry out the method of the invention appropriately comprises at least one trough receiving the bath of sizes and viscous dye; the warps to be treated being made to pass through the trough by means of conveyor rollers.
However, it is equally feasible to sequentially mount, directly in cascade, one trough for the size and one trough for the dye. It should be noted, however, that the size and the dye are deposited in a single, in-line operational step.
In the preferred embodiment of the present invention, the trough(s) are be mounted in-line directly in front of a drying chamber wherein the warps treated with size and dye are subjected to drying. This design allows further treatment of the dyed warps beyond the drying chamber proper, for example, to print and coat the dyed warps, and in particular in the form of wet-in-wet treatment feasible for dyes or coatings in the form of dispersion coatings. However, the apparatus of the present invention also makes it possible to mount a further printing system in-line and directly after the drying chamber proper, so that coating the warps with dye, lacquer, dispersions or the like is possible after the drying procedure.
In the latter embodiment, the printing system may comprise a dye reservoir from which dye is fed to the surfaces of printing rollers. The printing rollers can be forced against a rest surface, with the warps inserted therebetween; the rest surface being a lower roller. In particular, this design allows shaping the lower-roller surfaces so as to achieve different pressures on the warps at different roller locations.
Advantageously, the emulsion consisting of dye and size, contained in a reservoir and transferrable into the trough(s), shall be kept in a fluid state, wherein at least one agitator system is provided for the purpose of maintaining a fluid state by acting on the substance. Corresponding considerations regarding agitators apply to the dye receptacles.
Depending on the particular requirements, the agitator systems may be adjusted in such manner that they do not agitate the entire substance, but only a portion of it. As a result, marbling veins or tracks shall be formed and transferred to the warps. In this manner, corresponding patterns will be formed on the finished textiles, and these patterns can further be controlled by brushes or the like at the post-processing stages in manners known, per se, to produce the final-dyed warps.
The particular dye may be fed from dye receptacles to the troughs via feed lines, wherein the receptacles are equipped with a return line and a pump in order to return unused dye from the troughs to the dye receptacles. Therefore, the dye can be used up almost in its entirety.
Dyeing by the wet-in-wet procedure may also be achieved by the method and apparatus of the instant invention.
In this manner, excess dyes still contained in the warps may be squeezed out laterally and reach adjacent zones; thus, further affecting the color pattern.
Brush processing can take place both in front of and behind the drying chamber. However, brush processing may take place in front of the drying chamber only when dyeing has taken place beforehand.
At least one dye receptacle may be connected to size feed lines, wherein thickened pastes of dye pigments are fed in a controlled manner from the receptacle(s) to the size.
The dye recipes can be selected in such manner that the desired quantities of dye are absorbed simultaneously or adhere in part or in whole to the warps, even though the sizes are deposited at full production speed as mentioned above. The recipes can be controlled in such manner that a choice can be made between excesses and shortages of dye. Excesses of dye illustratively may be used so that, after a special desizing procedure, the filling threads are dyed at the same time. Thus, a dye magazine with dye pigment pastes may be additionally connected to the feed lines for the sizing materials, as a result of which the dye can be fed, in addition and as required, to the sizing materials.
Moreover, it is possible to simultaneously dye the initially separately arriving warps in different colors using separately controlled size receptacles.
It is furthermore possible to make use of a closed dye circuit passing through one or several dye receptacles to change the dyes as the warps keep moving and to prevent losses from standing or accumulations.
The closed dye loops ensure almost full consumption of the supplied material, as a result of which additional wastes are averted in production.
Wet-in-wet printed dye or dye-structure effects can be achieved in the immediate operational vicinity of the drying chamber by means of synchronously operating dye or deposition systems for the warps which can be adjustably dried in a drying chamber of which the humidity is monitored. In addition, further yarn changes and effects can be achieved by the actions of concurrently operating sponging, smoothing and brush rollers.
Again, the sorted incoming warps can be processed directly upon leaving the drying chamber by means of a further synchronously operating dyeing or deposition system. Because all warps are already being sorted at that site and are exiting while hot, the entire set of warps can be printed, coated or processed with arbitrary patterns. By printing or coating these hot warps, a novel interaction has been created between the printing and coating material on one hand, and on the other, the warps.
This effect is reinforced by the alternating exit of the warps from the fabric top and bottom sides.
The invention is elucidated below in relation to illustrative embodiments shown in the drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic elevation of one embodiment of the overall equipment of the invention,
FIG. 2 is a schematic elevation on an enlarged scale relative to FIG. 1 of that part of the equipment wherein the warps are coated and dyed,
FIG. 3 is a schematic elevation enlarged relative to FIG. 1 of that part of the equipment where the warps are additionally printed or coated.
DESCRIPTION OF THE PREFERRED EMBODIMENT
In all Figures, the warps move through the equipment in the direction of arrow 1, that is, from left to right as shown.
The initially untreated warps are wound on bobbins 2 or the like and pass through separating and sorting devices 3. Next, there is a drying chamber 4 with a housing 5 which to save energy may also includes the equipment of FIG. 2. As schematically shown in FIG. 1, two or more sequential troughs 6 may be used for coating in the above described manner. This equipment part is denoted by 7 (also see FIG. 2).
Because the warps have already been separated into upper and lower threads in the antechamber 8 containing the bobbins 2, the warps can be assigned to different troughs 6, as shown in FIG. 1. It should be noted that the troughs may be filled with different sizing agents or sizes, but are preferably filled with different dyes.
In the embodiment shown in FIG. 1, first the lower threads 10 and then the upper threads 9 are coated.
The warps so coated and dyed pass over preferably heated rollers 11 and 12 into the actual drying chamber 4 where their drying is completed. Because the drying chamber 4 and the heating-roller equipped compartments 13 and 14 are subjected to air heating (a temperature of about 140° C. being generated in the drying chamber, that is, within the housing 5), pre-drying takes place in the compartments 13 and 14 and this pre-drying is completed in chamber 4. As a result of which, the dried threads are hot when they exit the drying chamber in the direction of arrow 15.
Seen in the direction of advance, the equipment part 16 of FIG. 3 follows and joins the drying chamber; the equipment part 16 being inside the compartment 17. The coated and dyed warps leave the compartment 17 in the direction of arrow 18, and, as shown, are separated into upper and lower threads. In other words, the warps are sorted so that they may be wound on warp beam 19 or the like. For that purpose, the warp beam rotates in the direction of arrow 20.
As discussed above, the drying chamber 5 is equipped with an air heating system 21 of which the heater element is denoted by 22. The piping of the heating system 21 comprises hot or warm-air discharge means 23 and 24 through which the heated air is fed to the compartment 17 and also to compartments 25 and 26. In the preferred embodiment, the compartments 25 and 26 also serve to heat the pre-heating compartments 13 and 14.
As shown by FIG. 1, the compartments 25 and 26 hold the equipment parts represented by FIG. 2, which comprise a trough 6 holding a mixture or an emulsion of the sizes and the viscous dye. The warps 9 and 10 are made to pass through the trough 6 by means of rollers 27 and 28 (also see FIG. 2). The trough 6 is connected by a pipe system 29 to the drains 30 of individual dye receptacles 31 and 32, wherein the drains 30 can be selectively closed by valves 33. Unconsumed material is returned until total consumption has taken place to the dye receptacles 32 by means a return line 34 driven by at least one pump 35. It should be noted that, as illustrated in FIG. 1 and described above, the embodiment of the instant invention may comprises more than one sequential trough 6 wherein a trough containing size and a trough containing dye are mounted directly one behind the other. The size and dye are thus deposited in-line in a single operational stage. Moreover, the piping arrangement which supplies dye and size may be designed to provide a flexible distribution system for selectively supplying varying amounts of dye and size to the warps.
As shown in FIG. 2, the trough 6 is provided with control equipment which regulates the the amount and condition of the size and dye mixture supplied to the trough 6. By way of example, the trough 6 is provided with a quantity sensor which controls the amount of mixture supplied to the trough to ensure efficient and effective treatment of the warps. Additionally, the trough 6 is provided with an agitator to maintain the mixture in a liquid state.
The individual dye receptacles 31, 32 comprise agitating means 36 which keep the viscous or pasty dyes in the dye receptacles 32 in a fluid state.
A vessel, or reservoir 37 holds the size and dye mixture and is treated with an agitator 38 which is driven by a motor 39; just as are the motors of the agitators 36 of FIG. 2.
The size reservoir 37 also comprises a drain stub 40 with a shutoff valve 41 mounted in a line 42 leading to a pump 43 feeding the size upward in the direction of the arrow 54 into the trough 6. Therefore, the reservoir 37 and pump 43 serve to regulate the amount mixture supplied to the trough(s) 6. The vessel 37 further communicates by a connecting line 44 with the drains 30 of the dye receptacles 32, wherein the connecting line 44 also contains a shutoff valve 45. Therefore, the dye contained in the dye receptacles 32 can be fed in varying quantities, in varying compositions and where called for in varying consistencies into the size reservoir 37. The piping arrangement described above is not, however, limited to those embodiments shown in FIGS. 1-3, but rather is designed to efficiently and economically distribute the dye and size in desired amounts to desired locations.
FIG. 3 shows that part of the equipment belonging in the compartment 17 of FIG. 1 and which to some extent serves to post-process the treated warps. As shown by FIG. 3, additional printing may be applied by the wet-in-wet procedure in this post-processing stage, for instance, by using synchronously cooperating dye or deposition devices 46. Moreover, additional smoothing rollers 47, sponge rollers 48 and brush rollers 49 may be co-rotating to achieve further changes and effects in the yarn.
In one embodiment, the dyes which shall be deposited by means of a feed-line system 50 are only deposited in this instance by feed stubs 51 from above on the rollers; this post-process does not use baths for treatments as in the previous discussion. However, this post-process may comprise a bath or trough for treatment as illustrated in FIG. 3.
At the exit (see arrow 18 of FIG. 1), the warps 9 and 10 are so hot that the entire set of warps can be printed, coated or worked-on with arbitrary patterns. For that purpose and as shown by FIG. 1, dye can be deposited on warps 9 and 10 by a further synchronous dye or deposition device 52 (FIG. 1), and at the same time the dye may be dried by being in contact with the hot warps. Thus, a novel interaction is created between the printing and coating material on one hand and on the other the warps by the printing or coating of these hot warps.
While the invention has been particularly shown and described with reference to a preferred embodiment, it will be understood by those having ordinary skill in the art that various changes in form and detail may be made therein without departing from the spirit and scope of the invention.
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The instant invention provides a method for treating, in particular, for dyeing fabric warps, wherein the warps in the raw (white) state pass through a so-called sizing bath which rigidifies them and makes them more wear-resistant. The warps so treated are then woven and the textile so made is dyed in a manner to drastically lower costs. The invention calls for untreated warps in the raw (white) state to pass in-line through at least one bath containing the size in a single operational step, the dyes to be deposited being present as a viscous or pasty substance in the bath in addition to the size.
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CROSS-REFERENCE TO RELATED APPLICATIONS
This application is based on and claims the priority date of Applicant's co-pending U.S. Provisional Patent Application Ser. No. 60/786,512, entitled BENDABLE POST and filed on Mar. 28, 2006, by Thomas A. Ebel and Brian Kronenmeyer, the disclosure of which is incorporated herein by reference.
BACKGROUND OF THE INVENTION
The invention relates to sign posts, mailbox posts, and the like. More specifically, the invention includes a damage resistant flexible post mount that provides a stable post mount, which deflects under lateral loading, such as being pushed by a vehicle, and returns to its unloaded, upright condition.
Vehicle damage to sign posts and the like is commonly known and frequently occurs in many varied situations, which accumulates into a significant expense to repair damages and broken signage. Conversely, damage from vehicle and sign encounters also results in expensive damages to the vehicles.
While attempts have been made to address the issue of damage to signs by vehicles and to vehicles by signs, the previous suggestions have typically attempted to shift the damage to the sign in order to save the vehicle or attempted to develop resilient signage. These attempts have generally resulted in “disposable” signage that is sacrificed in deference to the vehicle, with associated shift of expense to replacement signage. Alternatively, the result has been compromised signage that may, at best, not shift cost to the signage, but also does not provide acceptable sign performance, including signs that may wobble or not stand.
BRIEF SUMMARY OF THE INVENTION
Accordingly, a bendable post of the invention provides an unique answer to the dilemma of impact damage to sign and mailbox posts and the like, with a sturdy and resilient post mount that diminishes post and vehicle damage and costs, is economical to use, and provides desirable performance in various environments.
In some aspects of the invention, the post is provided with a resilient foundation assembly whereby the post may pivot and deflect from a generally vertical orientation when a lateral force is applied to the post and the post may return to the generally vertical orientation when no lateral force is applied to the post. The foundation assembly including a foundation, a top assembly, and a resilient interconnection between the post and the top assembly.
In other aspects of the invention, the a foundation may be defined at one of a dirt, a concrete, and an asphalt surface. The top assembly may releasably couple with the foundation. The top assembly may include a plate and a stub that extends generally vertically upward from the plate. A resilient interconnection may be provided between the top assembly and the post. Further, a frangible interconnection may be provided between the resilient interconnection member and one of the post and the stub.
These and other features, objectives, and benefits of the invention will be recognized by one having ordinary skill in the art and by those who practice the invention, from this disclosure, including the specification, the claims, and the drawing figures.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING
FIG. 1 is a front elevation view of a bendable post of the invention, showing an information sign;
FIG. 2 is a fragmentary perspective view showing a bendable post of the invention in a mailbox post installation;
FIG. 3 is a left-side perspective view of a bendable post of the invention, showing a pavement mounted post bent by a vehicle;
FIG. 4 is a right rear perspective view thereof;
FIG. 5 is an upper front left perspective view of a base plate thereof;
FIG. 6 is an upper front perspective view thereof;
FIG. 7 is a perspective view of a pavement post assembly with top plate assembly and spring of a bendable post of the invention;
FIG. 8 is an enlarged fragmentary perspective view detail thereof;
FIG. 9 is another enlarged fragmentary perspective view detail thereof;
FIG. 10 is a lower perspective view of each of a pavement post base assembly and a dirt post base assembly of a bendable post of the invention;
FIG. 11 is an upper perspective view of the dirt post base assembly thereof;
FIG. 12 is another upper perspective view thereof;
FIG. 13 is a lower perspective view thereof;
FIG. 14 is a view of components of a concrete mounting kit of a bendable post of the invention, including concrete expandable studs, washers, and nuts;
FIG. 15 is a partial fragmentary exploded view of a bendable post of the invention, including pavement post assembly;
FIG. 16 is a side elevation view of the pavement post assembly thereof;
FIG. 17 is another side elevation view thereof;
FIG. 18 is a top plan view thereof; and
FIG. 19 is a perspective view thereof;
FIG. 20 is a top plan view of a top plate assembly of the bendable post of FIG. 15 ;
FIG. 21 is a side elevation view thereof;
FIG. 22 is another side elevation view thereof;
FIG. 23 is a top perspective view thereof;
FIG. 24 is a top plan view of a base plate of a pavement post assembly of a bendable post of the invention;
FIG. 25 is an edge view thereof;
FIG. 26 is another edge view thereof; and
FIG. 27 is a perspective view thereof;
FIG. 28 is a side elevation view of a base rod of the pavement post assembly;
FIG. 29 is another side elevation view thereof;
FIG. 30 is a top plan view thereof; and
FIG. 31 is a perspective view thereof;
FIG. 32 is a plan view of a top plate assembly of a bendable post of the invention;
FIG. 33 is an edge view thereof;
FIG. 34 is another edge view thereof;
FIG. 35 is a perspective view thereof;
FIG. 36 is a side elevation view of a top plate tube of the top plate assembly;
FIG. 37 is a plan view thereof;
FIG. 38 is another side elevation view thereof;
FIG. 39 is a top perspective view thereof;
FIG. 40 is a partial fragmentary exploded view of a bendable post of the invention, including a dirt base assembly;
FIG. 41 is a side elevation of the dirt base assembly thereof;
FIG. 42 is another side elevation thereof;
FIG. 43 is a top plan view thereof;
FIG. 44 is an upper perspective view thereof;
FIG. 45 is a side elevation of a gusset thereof;
FIG. 46 is an edge view thereof;
FIG. 47 is another edge view thereof;
FIG. 48 is a side perspective view thereof;
FIG. 49 is a side elevation view of a mail box post assembly base for a bendable post of the invention;
FIG. 50 is another side elevation view thereof;
FIG. 51 is a bottom plan view thereof; and
FIG. 52 is a lower perspective view thereof;
FIG. 53 is a fragmentary orthogonal view of an alternative embodiment of the invention, showing use of a square tubing upper post;
FIG. 54 is another fragmentary orthogonal view thereof;
FIG. 55 is an end plan view of a helical coil spring of the invention, the opposite end being a duplicate image thereof;
FIG. 56 is a side elevation view thereof;
FIG. 57 is another side elevation view thereof; and
FIG. 58 is an orthogonal projection thereof.
DETAILED DESCRIPTION OF THE INVENTION
A preferred embodiment of a bendable post according to the invention is generally shown in the drawing figures and discussed below. A bendable post of the invention may be utilized in various installations including a mailbox post (FIGS. 2 and 49 - 52 ), a pavement placed sign post ( FIGS. 1 , 3 - 10 , and 14 - 39 ), and a dirt placed sign post ( FIGS. 10-13 , 20 - 23 , and 32 - 48 ).
Addressing the common components of the various bendable post adaptations, each bendable post has a foundation assembly, a top assembly 100 , a helical coil spring 200 ( FIGS. 55-58 ), and an upper post 300 . The foundation assembly may vary according to specific mounting situations.
The upper post 300 may be of any suitable construction for a sign application or the like of interest and in the present example may include a 1.625 inch (41.3 mm) outside diameter SS20 galvanized steel post ( FIGS. 1-6 , 15 , and 40 ). Various color treatments may be optionally applied, including painting, powder coating, and sheathing as is understood by one having ordinary skill in the art.
The upper post is fitted closely in the coil spring 200 . Consistent with the example tube 300 , the spring may have an inside diameter of about 1.66 inch (42.2 mm). Various constructions may be used for the spring 200 and use of a 0.437 (11.1 mm) carbon steel wire has been found to provide good performance. One having ordinary skill in the art understands that different finishes and coatings may be applied to the spring and that materials and dimensions may be modified, all with beneficial and detrimental results as to durability and stiffness and the like.
The spring 200 may overlap the post 300 in various amounts depending upon various factors, including a user's desired result and actual post and spring dimensions. A range of about 1-3 inches (25-76 mm) may cover most installations. While various methods may be used to connect the spring and the post, including welding and adhesives, a loop 204 and 206 respectively, is more preferably formed at each opposing end of the spring and the spring is bolted together with the tube using a bolt 202 . In keeping with the example tube 300 , the loop may be adapted for slip fit of a 0.562 inch (14.28 mm) bolt through the loop. Of course, the post 300 is most preferably predrilled for slip fit of the bolt through the post ( FIGS. 5 , 6 , 15 , and 40 ). Further, the bolt is positioned at a spacing from the end of the post according to a preselected amount of overlap of the spring over the post. Standard washers are preferably used at each end of the bolt and the bolt may be secured in place with a variety of fasteners. A lock nut 208 may be preferred.
The fabrication of the bolt 202 may be dictated by various factors, including strength and durability. Some anticipated fabrications include stronger materials like common mild steel, which is commonly found at a hardware store, and more frangible materials like aluminum and plastics. A frangible bolt may be desired in installations where particular circumstance heighten safety or damage considerations. Thus, a “shear pin” effect at the bolt may be provided with softer or more frangible bolt fabrication.
Two opposing ends of the spring 200 may be constructed substantially the same for simplicity. Thus, having discussed connection of the spring 200 with the post 300 at one of the opposing ends of the spring, the second of the spring ends is connected with the top assembly 100 in similar manner. More specifically, the top assembly is provided with a plate 110 and a stub tube 120 . The plate may be a mild steel square with an about 9-9.5 inch (229-241 mm) side and an about 0.1875 to 0.25 inch (4.76-6.35 mm) thickness to keep in scale with the example post 300 .
The stub tube 120 mirrors the post 300 , being a length of 1.625 inch (41.3 mm) outside diameter SS20 tube. A length of about 3.5 inches (89 mm) for the tube 120 has been found to provide sufficient length for assembly, for maintenance, and for proper positioning of the spring 200 , that is, positioning of the flex point of the bendable post. As with the amount of overlap of the spring over the post, the length of the stub tube may also vary. The stub tube may conveniently be welded with the plate 110 and extend perpendicularly from one side of the plate.
Again, the spring preferably connects with the stub 120 substantially as with the post 300 . The spring 200 mates in slip fit engagement with the stub and may preferably overlap the stub 120 about two inches (50.8 mm), although this may be found to more preferably be anywhere in a range of about 1-3 inches (25-76 mm) as discussed above regarding the overlap of the spring on the post 300 . The stub tube 120 and the spring are bolted together with the tube using a bolt 212 . The stub is, therefore, pre-drilled for slip fit of the bolt through the stub. As with the spring loop 204 at the opposite spring end, the bolt also slip fits through a twin of the opposite spring loop 214 . Further, the bolt 212 may be identical to the bolt 202 . Although, consideration may be given to whether each, only one, or neither of the bolts provides “shear pin” protection as discussed above.
More specifically, as to the spring 200 , an overall length of the spring may be determined in part by post bendability characteristics. A more rigid coupling of the post 300 with the top plate assembly 100 is provided with the upper post 300 and the stub tube 120 abutting one another. Given the spring overlapping each of the post and the tube about two inches (50.8 mm), the spring would have a length of about four inches (101.6 mm). There is potential, however, for deformation of the upper post end and to the stub tube in this configuration. The spring may also experience a plastic deformation.
Alternatively, and perhaps at the other end of the spectrum, the upper post 300 may be spaced from the stub tube 120 , so at least about five spring coils are between the post and the tube. For the example spring 200 , this would be a space between the post and the tube of about 2.185 inch (55.5 mm) with a resulting spring length of at least about six inches (152 mm).
In a first alternative configuration of the post assembly, each of the cylindrical upper post 300 and the cylindrical stub tube 120 may be replaced with lengths of a square tube, providing post 400 and tube 420 ( FIGS. 53 and 54 ), although one having ordinary skill in the art understands that other tube cross section shapes, including rectangular and oval, may be desired under particular circumstances. Further, the square post 400 and the tube 420 may have miter cut ends and abut at a miter cut joint 430 , as contrasted with the square cut ends of the post 300 and tube 120 , above, although a post of any cross section may have a “mitered” end or interface with its supporting stub tube.
In whatever post and tube configuration, 300 and 120 or 400 and 420 , respectively, for example, a number of foundation assemblies may be used for different mounting situations, as suggested above. The foundation assemblies may include a concrete pavement mounting situation (FIGS. 1 and 3 - 6 , 14 ), an asphalt pavement mounting situation ( FIGS. 7-10 , and 15 - 19 ), a dirt mounting situation ( FIGS. 10-13 , and 40 - 48 ), and a mailbox post mounting situation (FIGS. 2 and 49 - 52 ). Each alternative mounting foundation includes a foundation or base plate 500 ( FIGS. 24-27 ) that provides a cooperating base for the plate 110 of the top plate assembly 100 . Thus, the base plate 500 may be quite similar to the plate 110 and may be a corresponding mild steel square with a corresponding side of about 9-9.5 inch (229-241 mm) and an about 0.1875 to 0.25 inch (4.76-6.35 mm) thickness to keep in scale with the example. Each of the top plate assembly 100 and the base plate 500 is provided with aligned coupling holes at their respective corners. While the top plate assembly may be drilled for slip fit of cooperating mounting bolts, the base plate may be cut with square holes for convenient use of carriage bolts or the like as shown in the drawing.
Relative to concrete pavement mounting, the base plate may further be provided with a set of concrete mounting holes 510 ( FIG. 24 ). The holes 510 are sized and positioned as desired to cooperate with set anchors or bolts. A common variety of concrete anchor is shown in FIG. 14 and may be used as is known by one having ordinary skill in the art.
For asphalt pavement mounting, the base plate may further be provided with a stake 520 that extends perpendicular to and downward from the plate 500 when installed. An about four foot (1219 mm) length of an about one inch (25.4 mm) diameter solid steel rod has been found to provide good foundation stability in context of the present example. The asphalt foundation is easily installed by drilling a hole through the pavement and driving the stake 520 through the asphalt hole until the base plate 500 is seated at the pavement surface. Of course, and end of the rod that is away from the base plate may be beveled or otherwise sharpened to enhance penetration. Again, the base plate is bolted with the top plate assembly 100 as discussed above.
When placing a bendable post of the invention in turf or other dirt environments, the foundation is easily provided with a modification of the above asphalt foundation. For dirt mounting, the asphalt foundation may further be provided with stabilizers 530 , including fins as shown ( FIG. 40 ). One having ordinary skill in the art knows that factors such as the number, the size, the shape, and the positioning of the stabilizers may change to adapt the dirt or turf foundation to different soil conditions. An obvious adaptation that the invention anticipates, for example, is use of an auger fin whereby a soil based foundation may be seated into place by screw auger.
Finally, an example of an adapting mailbox foundation 700 to retro-fit a mailbox post installation with a bendable post of the invention is shown in the drawing at FIGS. 49-52 . A notable modification as compared with the asphalt foundation is that the stake 520 is replaced with a length of nominal 3×3×11 gauge (0.120 inch) (76×76×3 mm) square tubing 540 . The tube may have a length that is sized as desired for local soil and frost considerations as well as for the alternative staking configurations discussed above, namely, the asphalt foundation and the turf foundation. An anticipated range of common lengths for the square tube 540 is about 30 to 48 inches (762-1220 mm), although this is not critical to the invention because experimentation or calculation relative to specific installations may determine an optimal secure foundation for the specific installation.
In an alternative statement, the present invention can be used in connection with signs of a variety of sizes, ranging from the likes of parking space restriction signs, stop signs, and other traffic direction signs to larger roadside signs used for advertising and their like, to smaller signs for particular uses. In the illustrated normal use of a traffic control sign, the support post typically are formed of galvanized steel tubular posts having an external diameter of about 1.66 inches. The post diameter can vary between 1 and 3 inches for a median range of sign sizes and can even be as small as ½ inch for particularly small applications. Posts are formed of galvanized steel or painted steel or other suitably rigid material. The posts typically are round but could be square or other shapes.
In the embodiments of the invention generally illustrated in the drawing, the posts are round, and the upper and lower sections are shown spaced apart by a predetermined distance. A round coil extension spring (with contiguous coils) fits over the upper and lower sections of the post. In a typical installation, a spring 9 inches long is employed, with the spring overlapping the upper and lower post by 3 inches and having a 3-inch section extending between the upper and lower post. The gap between the upper and lower post is important because it provides a number of active coils of the spring, so that the spring can bend over under elastic deformation from a vertical angle preferably to a 90 degree or perpendicular angle with respect to the lower section of the post. In the preferred practice of the present invention, the 3-inch gap between the upper and lower sections of the post provides room for 5 active coils of the 9-inch spring. The spring would work with 2-9 coils or more, and a more preferred range is 3-7 active coils between the upper and lower sections of the post. An excessive number of active coils makes the post less stable and the spring more expensive, while a smaller number of active coils constrains the range of deflection without plastic deformation of the spring.
While the spring desirably may be about 9 inches long, a spring length of 3-15 inches would be operative, and a spring length range of 6-12 inches is a more preferred range. The length of the spring is basically controlled by cost, a longer spring generally being unnecessary. The shorter the spring, the more likely the spring is to plastically deform when bent or to slip off the ends of the post if the spring does not overlap the post adequately.
The gap between the posts desirably is 3 inches but can range from 1-5 inches. A smaller gap may not provide enough active coils to permit a 90 degree bend in the sign without deforming the coils, but it would provide a substantial bend that may be satisfactory under certain conditions.
In order to provide a sign support that does not wobble under normal conditions, a substantially rigid spring is necessary. In the illustrated embodiment, the spring is a closed loop steel spring having a wire diameter of ⅝ inch. A wire diameter of ½ inch or somewhat less will work. A wire diameter of ⅜ inch is generally not satisfactory for a sign of the type illustrated in the present application. A wire diameter of 1 inch or perhaps more may be desirable for large, roadside signs. The wire diameter and number of active coils is selected to provide a sign that is substantially rigid under normal conditions but which deflects readily under impact of a vehicle or the like.
The spike on the bottom of the base desirably is formed of wrought iron or steel but can be formed of any suitably rigid material. The spike can be round, square, or virtually any shape, including hollow. The spike can be from 18-48 inches long, depending upon the application. A longer spike is necessary for a large sign or a loose sandy soil, whereas a shorter spike may be sufficient for a compact clay soil or a lighter weight sign.
One having ordinary skill in the art and those who practice the invention will understand from this disclosure that various modifications and improvements may be made without departing from the spirit of the disclosed inventive concept. One will also understand that various relational terms, including left, right, front, back, top, and bottom, for example, are used in the detailed description of the invention and in the claims only to convey relative positioning of various elements of the claimed invention.
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A bendable mailbox or sign post comprises a foundation defined at one of a dirt, a concrete, and an asphalt surface. A top assembly releasably couples with the foundation and has a plate and a stub extending upward from the plate. The elongated post extends vertically from a bottom end connected with the top assembly. A resilient interconnection is provided between the post and the top assembly, whereby the post pivots about the bottom end and deflects from its vertical orientation when a lateral force is applied to the post and the post returns to the vertical orientation when no lateral force is applied. A frangible interconnection may be provided between the resilient interconnection member and one of the post and the stub.
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FIELD OF THE INVENTION
[0001] The present invention relates to an improved synthetic process for preparing bicyclic pyrazolyl compounds, in particular, 3-(4-chloro-phenyl)-2-(2-chloro-phenyl)-7-(2,2-difluoro-propyl)-6,7-dihydro-2H,5H-4-oxa-1,2,7-triaza-azulen-8-one. The bicyclic pyrazolyl compounds have been found to be CB1 receptor antagonists and are therefore useful for treating diseases, conditions and/or disorders modulated by cannabinoid receptor antagonists.
BACKGROUND
[0002] CB-1 antagonists have been shown to useful for the treatment of a variety of diseases, conditions and/or disorders including obesity, alcoholism, smoking cessation, Parkinson's disease, sexual dysfunctions, dementia, and so forth. Consequently, there exists a desire to develop compounds that antagonize the CB-1 receptor. US Publication No. 2005/0101592 (U.S. Provisional Patent Application Ser. No. 60/518,280 filed on Nov. 7, 2003) describes a series of bicyclic pyrazolyl and imidazolyl compounds that act as CB-1 antagonists. However, there exists a need to produce bicyclic pyrazolyl compounds, in particular 3-(4-chloro-phenyl)-2-(2-chloro-phenyl)-7-(2,2-difluoro-propyl)-6,7-dihydro-2H,5H-4-oxa-1,2,7-triaza-azulen-8-one, in a more efficient and cost effective means at larger scales of manufacture.
SUMMARY
[0003] The present invention provides an improved process for preparing compounds of Formula (I):
wherein
[0004] R 0a , R 0b , R 1b , and R 1c are each independently halo, (C 1 -C 4 )alkoxy, (C 1 -C 4 )alkyl, halo-substituted (C 1 -C 4 )alkyl, or cyano (preferably, R 0a is chloro, fluoro, or methyl; R 0b is chloro, fluoro, or hydrogen (i.e., m is 0); R 1c is chloro, fluoro, (C 1 -C 4 )alkyl, trifluoromethyl, (C 1 -C 4 )alkoxy, or cyano; and R 1b is hydrogen (i.e., n is 0));
[0005] n and m are each independently 0, 1 or 2 (preferably, n and m are 0 or 1, more preferably, n and m are both 0);
[0006] R 4 is a chemical moiety selected from the group consisting of (C 1 -C 8 )alkyl, aryl, heteroaryl, aryl(C 1 -C 4 )alkyl, a 3- to 8-membered partially or fully saturated carbocyclic ring(s), heteroaryl(C 1 -C 3 )alkyl, 5-6 membered lactone, 5- to 6-membered lactam, and a 3- to 8-membered partially or fully saturated heterocycle, where said chemical moiety is optionally substituted with one or more substituents;
[0007] a pharmaceutically acceptable salt thereof, or a solvate or hydrate of the compound, or the salt.
[0008] Preferably, R 4 is a chemical moiety selected from the group consisting of (C 1 -C 8 )alkyl, aryl(C 1 -C 4 )alkyl, 3- to 8-membered partially or fully saturated carbocyclic ring(s), and 3- to 8-membered partially or fully saturated heterocycle, where said chemical moiety is optionally substituted with one or more substituents. More preferably, R 4 is (C 1 -C 8 )alkyl, halo-substituted (C 1 -C 8 )alkyl (preferably, fluoro-substituted (C 1 -C 8 )alkyl), cyclopentyl, cyclohexyl, piperidin-1-yl, pyrrolidin-1-yl, or morpholin-1-yl.
[0009] Most preferably, the compound of Formula (I) is 3-(4-chloro-phenyl)-2-(2-chloro-phenyl)-7-(2,2-difluoro-propyl)-6,7-dihydro-2H,5H-4-oxa-1,2,7-triaza-azulen-8-one (e.g., R 0a and R 1c are both chloro; n and m are both 0; and R 4 is 2,2-difluoro-n-propyl).
[0010] The process for preparing the compounds of Formula (I) described above comprises the steps of:
[0011] (1) protecting the hydroxy group of a compound of Formula (1a) with a hydroxy-protecting group to form a hydroxy-protected compound of Formula (1b)
where R 0a , R 0b , R 1b , R 1c , m, and n are as defined above for the compound of Formula (I) and Pg is a hydroxy-protecting group;
[0012] (2) reacting the hydroxy-protected compound of Formula (1b) with a compound of Formula (1c) to form a compound of Formula (1d)
where R 0a , R 0b , R 1b , R 1c , m, n and R 4 are as defined above for the compound of Formula (I) and Pg is a hydroxy-protecting group;
[0013] (3) converting the hydroxy group of the compound of Formula (1d) to a leaving group to produce a compound of Formula (1e)
where R 0a , R 0b , R 1b , R 1c , m, n and R 4 are as defined above for the compound of Formula (I), Pg is a hydroxy-protecting group, and L is a leaving group (e.g., halo, mesylate, tosylate, or any group capable of being displaced by an oxygen anion);
[0014] (4) removing said hydroxy-protecting group and cyclizing the compound of Formula (1e) to form the compound of Formula (I); and
[0015] (5) isolating the compound of Formula (I), or a pharmaceutically acceptable salt thereof, or a solvate or hydrate of the compound or salt.
[0016] An advantage of this process is that the compound of Formula (1a) can be converted to the compound of Formula (1e) without isolating the compound of Formula (1b) or the compound of Formula (1d).
[0017] The process described above may further comprise the following step
[0018] wherein the compound of Formula (1a) is prepared by a method comprising the steps of
[0019] (i) reacting a compound of Formula (2a) with a dialkyl oxalate in the presence of an alkali metal base (e.g., an alkali metal amide of a sterically hindered secondary amine (lithium bis(trimethylsilyl)-amide, lithium diisopropylamide, and lithium 2,2,6,6-tetramethylpiperidine), an alkali metal hydride (e.g., lithium hydride, sodium hydride, potassium hydride) or an alkali metal alkoxide (e.g., sodium ethoxide and sodium methoxide)) to form a compound of Formula (2b)
where R 1b , R 1c and n are as described above for the compound of Formula (I), M is an alkali metal (e.g., lithium, sodium or potassium) and R is a (C 1 -C 6 )alkyl group;
[0020] (ii) reacting the compound of Formula (2b) with a compound of Formula (2c) followed by treatment with an alkali metal hydroxide to form a compound of Formula (2d)
where R is a (C 1 -C 6 )alkyl group, M is as defined above, and R 0a , R 0b , R 1b , R 1c , n and m are as defined above for the compound of Formula (I); and
[0021] (iii) reacting the compound of Formula (2d) with a trialkylborate in the presence of an alkyl lithium followed by treating with basic hydrogen peroxide to produce the compound of Formula (1a). An example of a basic hydrogen peroxide is NaOOH which is formed by mixing aqueous sodium hydroxide with aqueous hydrogen peroxide.
[0022] In an alternative process, the compound of Formula (1a) can be prepared by a method comprising the step of
[0023] (i) hydrolyzing a compound of Formula (3d) to form the compound of Formula (1a)
where R 0a , R 0b , R 1b , R 1c , n and m are as defined above for the compound of Formula (I); and R is (C 1 -C 6 )alkyl.
[0024] In a preferred embodiment, the process is used to produce 3-(4-chloro-phenyl)-2-(2-chloro-phenyl)-7-(2,2-difluoro-propyl)-6,7-dihydro-2H,5H-4-oxa-1,2,7-triaza-azulen-8-one, or a solvate or hydrate thereof which comprises the steps of:
[0025] (1) protecting the hydroxy group of a compound of Formula (1a-1) with an acetyl group to form a compound of Formula (1b-1);
[0026] (2) reacting said compound of Formula (1b-1) with a compound of Formula (1c-1) to form a compound of Formula (1d-1)
[0027] (3) converting the hydroxy group of said compound of Formula (1d-1) to a chloro group to produce a compound of Formula (1e-1)
[0028] (4) removing said acetyl group and cyclizing said compound of Formula (1e-1) to form 3-(4-chloro-phenyl)-2-(2-chloro-phenyl)-7-(2,2-difluoro-propyl)-6,7-dihydro-2H,5H-4-oxa-1,2,7-triaza-azulen-8-one; and
[0029] (5) isolating said 3-(4-chloro-phenyl)-2-(2-chloro-phenyl)-7-(2,2-difluoro-propyl)-6,7-dihydro-2H,5H-4-oxa-1,2,7-triaza-azulen-8-one, or a solvate or hydrate thereof.
[0030] An advantage of this synthetic route is that the compound of Formula (1a-1) can be converted to the compound of Formula (1e-1) without isolating the compound of Formula (1b-1), or the compound of Formula (1d-1).
[0031] The compound of Formula (1a-1) may be prepared by treating a compound of Formula (2d-1) with an alkyl lithium (preferably, hexyllithium) and then reacting with a trialkylborate (preferably trimethylborate) followed by treating with basic hydrogen peroxide to produce the compound of Formula (1a-1).
[0032] In another embodiment of the present invention, an intermediate having the Formula (1d) is provided.
wherein
[0033] Pg is a hydroxy-protecting group;
[0034] R 0a , R 0b , R 1b , and R 1c are each independently halo, (C 1 -C 4 )alkoxy, (C 1 -C 4 )alkyl, halo-substituted (C 1 -C 4 )alkyl, or cyano;
[0035] n and m are each independently 0, 1 or 2; and
[0036] R 4 is a chemical moiety selected from the group consisting of (C 1 -C 8 )alkyl, aryl, heteroaryl, aryl(C 1 -C 4 )alkyl, a 3- to 8-membered partially or fully saturated carbocyclic ring(s), heteroaryl(C 1 -C 3 )alkyl, 5-6 membered lactone, 5- to 6-membered lactam, and a 3- to 8-membered partially or fully saturated heterocycle, where said chemical moiety is optionally substituted with one or more substituents. Preferably, Pg is acetyl; R 0a and R 1c are both chloro; m and n are both 0; and R 4 is 2,2-difluoro-n-propyl.
[0037] In yet another embodiment of the present invention, an intermediate having the Formula (1e) is provided.
wherein
[0038] Pg is a hydroxy-protecting group;
[0039] R 0a , R 0b , R 1b , and R 1c are each independently halo, (C 1 -C 4 )alkoxy, (C 1 -C 4 )alkyl, halo-substituted (C 1 -C 4 )alkyl, or cyano;
[0040] n and m are each independently 0, 1 or 2; and
[0041] R 4 is a chemical moiety selected from the group consisting of (C 1 -C 8 )alkyl, aryl, heteroaryl, aryl(C 1 -C 4 )alkyl, a 3- to 8-membered partially or fully saturated carbocyclic ring(s), heteroaryl(C 1 -C 3 )alkyl, 5-6 membered lactone, 5- to 6-membered lactam, and a 3- to 8-membered partially or fully saturated heterocycle, where said chemical moiety is optionally substituted with one or more substituents. Preferably, Pg is acetyl; R 0a and R 1c are both chloro; m and n are both 0; and R 4 is 2,2-difluoro-n-propyl.
[0042] Some of the compounds prepared by the processes described herein may exist as rotamers. For example, at least two major rotameric species have been observed by NMR for intermediates 1d-1, 1e-1, and I-1f (deprotected 1e-1). In addition, tautomeric forms of the compounds are also within the scope of the present invention.
Definitions
[0043] As used herein, the term “alkyl” refers to a hydrocarbon radical of the general formula C n H 2n+1 . The alkane radical may be straight or branched. For example, the term “(C 1 -C 6 )alkyl” refers to a monovalent, straight, or branched aliphatic group containing 1 to 6 carbon atoms (e.g., methyl, ethyl, n-propyl, i-propyl, n-butyl, i-butyl, s-butyl, t-butyl, n-pentyl, 1-methylbutyl, 2-methylbutyl, 3-methylbutyl, neopentyl, 3,3-dimethylpropyl, hexyl, 2-methylpentyl, and the like). Similarly, the alkyl portion (i.e., alkyl moiety) of an alkoxy, acyl (e.g., alkanoyl), alkylamino, dialkylamino, and alkylthio group have the same definition as above. Unless specified otherwise, “alkyl” is a general designation for a (C 1 -C 6 )alkyl. When indicated as being “optionally substituted”, the alkane radical or alkyl moiety may be unsubstituted or substituted with one or more substituents (generally, one to three substituents except in the case of halogen substituents such as perchloro or perfluoroalkyls) independently selected from the group of substituents listed below in the definition for “substituted.” “Halo-substituted alkyl” refers to an alkyl group substituted with one or more halogen atoms (e.g., “fluoro-substituted alkyl” refers to fluoromethyl, difluoromethyl, trifluoromethyl, 1-fluoroethyl, 2-fluoroethyl, 1,1-difluoroethyl, 1,2-difluoroethyl, 2,2-difluoroethyl, 1,1,1-trifluoroethyl, 2,2,2-trifluoroethyl, 1,1,2-trifluoroethyl, 1,2,2-trifluoroethyl, 1,2,2,2-tetrafluoroethyl, 1,1,2,2-tetrafluoroethyl, 1,1,1,2-tetrafluoroethyl, 1,1,2,2,2-pentafluoroethyl, 1,1,1,2,2-pentafluoroethyl, perfluoroethyl, etc.). Preferred halo-substituted alkyls are the chloro- and fluoro-substituted alkyls, more preferably, fluoro-substituted alkyls. When substituted, the alkane radicals or alkyl moieties are preferably fluoro substituents (as described above), or 1 or 2 substituents independently selected from (C 1 -C 3 )alkyl, (C 3 -C 6 )cycloalkyl, (C 2 -C 3 )alkenyl, aryl, heteroaryl, 3- to 6-membered heterocycle, chloro, cyano, hydroxy, (C 1 -C 3 )alkoxy, aryloxy, amino, (C 1 -C 6 )alkyl amino, di-(C 1 -C 4 )alkyl amino, aminocarboxylate (i.e., (C 1 -C 3 )alkyl-O—C(O)—NH—), hydroxy(C 2 -C 3 )alkylamino, or keto (oxo), and more preferably, 1 to 3 fluoro groups, or 1 substituent selected from (C 1 -C 3 )alkyl, (C 3 -C 6 )cycloalkyl, (C 6 )aryl, 6-membered-heteroaryl, 3- to 6-membered heterocycle, (C 1 -C 3 )alkoxy, (C 1 -C 4 )alkyl amino or di-(C 1 -C 2 )alkyl amino.
[0044] The terms “partially or fully saturated carbocyclic ring” (also referred to as “partially or fully saturated cycloalkyl”) refers to nonaromatic rings that are either partially or fully hydrogenated and may exist as a single ring, bicyclic ring or a spiral ring. Unless specified otherwise, the carbocyclic ring is generally a 3- to 8-membered ring. For example, partially or fully saturated carbocyclic rings (or cycloalkyl) include groups such as cyclopropyl, cyclopropenyl, cyclobutyl, cyclobutenyl, cyclopentyl, cyclpentenyl, cyclopentadienyl, cyclohexyl, cyclohexenyl, cyclohexadienyl, norbornyl (bicyclo[2.2.1]heptyl), norbornenyl, bicyclo[2.2.2]octyl, and the like. When designated as being “optionally substituted”, the partially saturated or fully saturated cycloalkyl group may be unsubstituted or substituted with one or more substituents (typically, one to three substituents) independently selected from the group of substituents listed below in the definition for “substituted.” A substituted carbocyclic ring also includes groups wherein the carbocyclic ring is fused to a phenyl ring (e.g., indanyl). The carbocyclic group may be attached to the chemical entity or moiety by any one of the carbon atoms within the carbocyclic ring system. When substituted, the carbocyclic group is preferably substituted with 1 or 2 substituents independently selected from (C 1 -C 3 )alkyl, (C 2 -C 3 )alkenyl, (C 1 -C 6 )alkylidenyl, aryl, heteroaryl, 3- to 6-membered heterocycle, chloro, fluoro, cyano, hydroxy, (C 1 -C 3 )alkoxy, aryloxy, amino, (C 1 -C 6 )alkyl amino, di-(C 1 -C 4 )alkyl amino, aminocarboxylate (i.e., (C 1 -C 3 )alkyl-O—C(O)—NH—), hydroxy(C 2 -C 3 )alkylamino, or keto (oxo), and more preferably 1 or 2 from substituents independently selected from (C 1 -C 2 )alkyl, 3- to 6-membered heterocycle, fluoro, (C 1 -C 3 )alkoxy, (C 1 -C 4 )alkyl amino or di-(C 1 -C 2 )alkyl amino. Similarly, any cycloalkyl portion of a group (e.g., cycloalkylalkyl, cycloalkylamino, etc.) has the same definition as above.
[0045] The term “partially saturated or fully saturated heterocyclic ring” (also referred to as “partially saturated or fully saturated heterocycle”) refers to nonaromatic rings that are either partially or fully hydrogenated and may exist as a single ring, bicyclic ring or a spiral ring. Unless specified otherwise, the heterocyclic ring is generally a 3- to 6-membered ring containing 1 to 3 heteroatoms (preferably 1 or 2 heteroatoms) independently selected from sulfur, oxygen and/or nitrogen. Partially saturated or fully saturated heterocyclic rings include groups such as epoxy, aziridinyl, tetrahydrofuranyl, dihydrofuranyl, dihydropyridinyl, pyrrolidinyl, N-methylpyrrolidinyl, imidazolidinyl, imidazolinyl, piperidinyl, piperazinyl, pyrazolidinyl, 2H-pyranyl, 4H-pyranyl, 2H-chromenyl, oxazinyl, morpholino, thiomorpholino, tetrahydrothienyl, tetrahydrothienyl 1,1-dioxide, and the like. When indicated as being “optionally substituted”, the partially saturated or fully saturated heterocycle group may be unsubstituted or substituted with one or more substituents (typically, one to three substituents) independently selected from the group of substituents listed below in the definition for “substituted.” A substituted heterocyclic ring includes groups wherein the heterocyclic ring is fused to an aryl or heteroaryl ring (e.g., 2,3-dihydrobenzofuranyl, 2,3-dihydroindolyl, 2,3-dihydrobenzothiophenyl, 2,3-dihydrobenzothiazolyl, etc.). When substituted, the heterocycle group is preferably substituted with 1 or 2 substituents independently selected from (C 1 -C 3 )alkyl, (C 3 -C 6 )cycloalkyl, (C 2 -C 4 )alkenyl, aryl, heteroaryl, 3- to 6-membered heterocycle, chloro, fluoro, cyano, hydroxy, (C 1 -C 3 )alkoxy, aryloxy, amino, (C 1 -C 6 )alkyl amino, di-(C 1 -C 3 )alkyl amino, aminocarboxylate (i.e., (C 1 -C 3 )alkyl-O—C(O)—NH—), or keto (oxo), and more preferably with 1 or 2 substituents independently selected from (C 1 -C 3 )alkyl, (C 3 -C 6 )cycloalkyl, (C 6 )aryl, 6-membered-heteroaryl, 3- to 6-membered heterocycle, or fluoro. The heterocyclic group may be attached to the chemical entity or moiety by any one of the ring atoms within the heterocyclic ring system. Similarly, any heterocycle portion of a group (e.g., heterocycle-substituted alkyl, heterocycle carbonyl, etc.) has the same definition as above.
[0046] The term “aryl” or “aromatic carbocyclic ring” refers to aromatic moieties having a single (e.g., phenyl) or a fused ring system (e.g., naphthalene, anthracene, phenanthrene, etc.). A typical aryl group is a 6- to 10-membered aromatic carbocyclic ring(s). When indicated as being “optionally substituted”, the aryl groups may be unsubstituted or substituted with one or more substituents (preferably no more than three substituents) independently selected from the group of substituents listed below in the definition for “substituted.” Substituted aryl groups include a chain of aromatic moieties (e.g., biphenyl, terphenyl, phenylnaphthalyl, etc.). When substituted, the aromatic moieties are preferably substituted with 1 or 2 substituents independently selected from (C 1 -C 4 )alkyl, (C 2 -C 3 )alkenyl, aryl, heteroaryl, 3- to 6-membered heterocycle, bromo, chloro, fluoro, iodo, cyano, hydroxy, (C 1 -C 4 )alkoxy, aryloxy, amino, (C 1 -C 6 )alkyl amino, di-(C 1 -C 3 )alkyl amino, or aminocarboxylate (i.e., (C 1 -C 3 )alkyl-O—C(O)—NH—), and more preferably, 1 or 2 substituents independently selected from (C 1 -C 4 )alkyl, chloro, fluoro, cyano, hydroxy, or (C 1 -C 4 )alkoxy. The aryl group may be attached to the chemical entity or moiety by any one of the carbon atoms within the aromatic ring system. Similarly, the aryl portion (i.e., aromatic moiety) of an aroyl or aroyloxy (i.e., (aryl)-C(O)—O—) has the same definition as above.
[0047] The term “heteroaryl” or “heteroaromatic ring” refers to aromatic moieties containing at least one heteratom (e.g., oxygen, sulfur, nitrogen or combinations thereof) within a 5- to 10-membered aromatic ring system (e.g., pyrrolyl, pyridyl, pyrazolyl, indolyl, indazolyl, thienyl, furanyl, benzofuranyl, oxazolyl, imidazolyl, tetrazolyl, triazinyl, pyrimidyl, pyrazinyl, thiazolyl, purinyl, benzimidazolyl, quinolinyl, isoquinolinyl, benzothiophenyl, benzoxazolyl, etc.). The heteroaromatic moiety may consist of a single or fused ring system. A typical single heteroaryl ring is a 5- to 6-membered ring containing one to three heteroatoms independently selected from oxygen, sulfur and nitrogen and a typical fused heteroaryl ring system is a 9- to 10-membered ring system containing one to four heteroatoms independently selected from oxygen, sulfur and nitrogen. When indicated as being “optionally substituted”, the heteroaryl groups may be unsubstituted or substituted with one or more substituents (preferably no more than three substituents) independently selected from the group of substituents listed below in the definition for “substituted.” When substituted, the heteroaromatic moieties are preferably substituted with 1 or 2 substituents independently selected from (C 1 -C 4 )alkyl, (C 2 -C 3 )alkenyl, aryl, heteroaryl, 3- to 6-membered heterocycle, bromo, chloro, fluoro, iodo, cyano, hydroxy, (C 1 -C 4 )alkoxy, aryloxy, amino, (C 1 -C 6 )alkyl amino, di-(C 1 -C 3 )alkyl amino, or aminocarboxylate (i.e., (C 1 -C 3 )alkyl-O—C(O)—NH—), and more preferably, 1 or 2 substituents independently selected from (C 1 -C 4 )alkyl, chloro, fluoro, cyano, hydroxy, (C 1 -C 4 )alkoxy, (C 1 -C 4 )alkyl amino or di-(C 1 -C 2 )alkyl amino. The heteroaryl group may be attached to the chemical entity or moiety by any one of the atoms within the aromatic ring system (e.g., imidazol-1-yl, imidazol-2-yl, imidazol-4-yl, imidazol-5-yl, pyrid-2-yl, pyrid-3-yl, pyrid-4-yl, pyrid-5-yl, or pyrid-6-yl). Similarly, the heteroaryl portion (i.e., heteroaromatic moiety) of a heteroaroyl or heteroaroyloxy (i.e., (heteroaryl)-C(O)—O—) has the same definition as above.
[0048] The term “substituted” specifically envisions and allows for one or more substitutions that are common in the art. However, it is generally understood by those skilled in the art that the substituents should be selected so as to not adversely affect the pharmacological characteristics of the compound or adversely interfere with the use of the medicament. Suitable substituents for any of the groups defined above include (C 1 -C 6 )alkyl, (C 3 -C 7 )cycloalkyl, (C 2 -C 6 )alkenyl, (C 1 -C 6 )alkylidenyl, aryl, heteroaryl, 3- to 6-membered heterocycle, halo (e.g., chloro, bromo, iodo and fluoro), cyano, hydroxy, (C 1 -C 6 )alkoxy, aryloxy, sulfhydryl (mercapto), (C 1 -C 6 )alkylthio, arylthio, amino, mono- or di-(C 1 -C 6 )alkyl amino, quaternary ammonium salts, amino(C 1 -C 6 )alkoxy, aminocarboxylate (i.e., (C 1 -C 6 )alkyl-O—C(O)—NH—), hydroxy(C 2 -C 6 )alkylamino, amino(C 1 -C 6 )alkylthio, cyanoamino, nitro, (C 1 -C 6 )carbamyl, keto (oxo), acyl, (C 1 -C 6 )alkyl-CO 2 —, glycolyl, glycyl, hydrazino, guanyl, sulfamyl, sulfonyl, sulfinyl, thio(C 1 -C 6 )alkyl-C(O)—, thio(C 1 -C 6 )alkyl-CO 2 —, and combinations thereof. In the case of substituted combinations, such as “substituted aryl(C 1 -C 6 )alkyl”, either the aryl or the alkyl group may be substituted, or both the aryl and the alkyl groups may be substituted with one or more substituents (typically, one to three substituents except in the case of perhalo substitutions). An aryl or heteroaryl substituted carbocyclic or heterocyclic group may be a fused ring (e.g., indanyl, dihydrobenzofuranyl, dihydroindolyl, etc.).
[0049] The term “solvate” refers to a molecular complex of a compound represented by Formula (I) or (II) (including prodrugs and pharmaceutically acceptable salts thereof) with one or more solvent molecules. Such solvent molecules are those commonly used in the pharmaceutical art, which are known to be innocuous to the recipient, e.g., water, ethanol, and the like. The term “hydrate” refers to the complex where the solvent molecule is water.
[0050] The term “protecting group” or “Pg” refers to a substituent that is commonly employed to block or protect a particular functionality while reacting other functional groups on the compound. For example, an “amino-protecting group” is a substituent attached to an amino group that blocks or protects the amino functionality in the compound. Suitable amino-protecting groups include acetyl, trifluoroacetyl, t-butoxycarbonyl (BOC), benzyloxycarbonyl (CBz) and 9-fluorenylmethylenoxycarbonyl (Fmoc). Similarly, a “hydroxy-protecting group” refers to a substituent of a hydroxy group that blocks or protects the hydroxy functionality. Suitable protecting groups include acetyl and silyl. A “carboxy-protecting group” refers to a substituent of the carboxy group that blocks or protects the carboxy functionality. Common carboxy-protecting groups include —CH 2 CH 2 SO 2 Ph, cyanoethyl, 2-(trimethylsilyl)ethyl, 2-(trimethylsilyl)ethoxymethyl, 2-(p-toluenesulfonyl)ethyl, 2-(p-nitrophenylsulfenyl)ethyl, 2-(diphenylphosphino)-ethyl, nitroethyl and the like. For a general description of protecting groups and their use, see T. W. Greene, Protective Groups in Organic Synthesis , John Wiley & Sons, New York, 1991.
[0051] The phrase “pharmaceutically acceptable” indicates that the substance or composition must be compatible chemically and/or toxicologically, with the other ingredients comprising a formulation, and/or the mammal being treated therewith.
DETAILED DESCRIPTION
[0052] The starting materials are generally available from commercial sources such as Aldrich Chemicals (Milwaukee, Wis.) or are readily prepared using methods well known to those skilled in the art (e.g., prepared by methods generally described in Louis F. Fieser and Mary Fieser, Reagents for Organic Synthesis , v. 1-19, Wiley, New York (1967-1999 ed.), or Beilsteins Handbuch der organischen Chemie, 4, Aufl. ed. Springer-Verlag, Berlin, including supplements (also available via the Beilstein online database)).
[0053] In the preparation of the bicyclic pyrazolyl compounds, protection of remote functionality (e.g., primary or secondary amine) of intermediates may be necessary. The need for such protection will vary depending on the nature of the remote functionality and the conditions of the preparation methods. Suitable amino-protecting groups (NH-Pg) include acetyl, trifluoroacetyl, t-butoxycarbonyl (BOC), benzyloxycarbonyl (CBz) and 9-fluorenylmethyleneoxycarbonyl (Fmoc). The need for such protection is readily determined by one skilled in the art. For a general description of protecting groups and their use, see Theodora W. Greene and Peter G. M. Wuts, Protective Groups in Organic Synthesis , John Wiley & Sons, New York, 2002.
[0054] Scheme I below summarizes the process of the present invention as well as key intermediates. For a more detailed description of the individual reaction steps, see the Examples section below. Although specific starting materials and reagents are depicted in the schemes and discussed below, other starting materials and reagents can be easily substituted to provide a variety of derivatives.
[0055] The compound of Formula (1a) can be prepared by either of the procedures outlined in Schemes II or III below. The hydroxy group on the pyrazole ring is protected with a hydroxy-protecting group before reacting with the desired hydroxyalkylamine compound (1c). Any hydroxy-protecting group can be used that is known in the art; however, an acetyl protecting group is preferred. For example, when an acetyl protecting group is used, a base (e.g., N,N-diisopropylethylamine) may be added slowly to a suspension of intermediate (1a) in a polar solvent (e.g., methylene chloride) at or slightly below room temperature followed by the addition of acetic anhydride. The carboxylic acid group on the pyrazole ring is then condensed with the desired hydroxyalkylamine compound (1c) to form an amide linkage. Standard amidation procedures well-known to those skilled in the art can be used. For example, compound of Formula (1b) can be treated with 2-chloro-4,6-dimethoxy-1,3,5-triazine followed by the addition of 4-methylmorpholine below room temperature and then slowly warmed to ambient temperature. The complex formed is then reacted with the desired hydroxyalkylamine compound (1c) to form the amide (1d) at a temperature between about 20° C. and about 25° C. The hydroxy group on the alkyl amine is converted to a leaving group (e.g., halo, mesylate, tosylate or any group capable of being displaced with the oxygen anion in the following cyclization reaction). When the leaving group is chloro, then the amide (1d) can be treated with a chlorinating agent (e.g., methanesulfonyl chloride in the presence of a base (e.g., N,N-diisopropylethylamine)) at a temperature of about 0° C. and then allowed to warm slowly to ambient temperature. Finally, the intermediate (1e) can be cyclized to the desired compound of Formula (I) (e.g., treatment with cesium carbonate at a temperature between about 20° C. and 30° C.). The advantage of this synthetic route is that the intermediate (1a) can be converted to the chloro intermediate (1e) in two steps without isolating any of the intervening intermediates (1b) or (1d).
[0056] An overview of ortho-metallation chemistry (i.e., conversion of intermediates 2d to 1a) may be found in Snieckus, V., Chem. Rev . (1990) 90, 879; Examples of ortho-metallation of aryl carboxylic acids can be found in Mortier, J., Moyroud, J, J. Org. Chem . (1994) 59, 4042 and Bennetau, B., Mortier, J., Moyroud, J., Guesnet, J., J. Chem. Soc. Perkin Trans. 1 (1995) 10, 1265. An example of an aryl-metal species being reacted with a trialkylborate followed by treatment with basic hydrogen peroxide to give a phenol can be found in Hawthorne, M., J. Org. Chem . (1957) 22, 1001. General procedures for using 4-methylmorpholine/2-chloro-4,6-dimethoxytriazine to make amides (i.e., conversion of intermediates 1b to 1d) may be found in Kaminski, Z. J., Synthesis (1987) 917; Kaminski, Z. J., Paneth, P., Rudzinski, J., J. Org. Chem . (1998) 63, 4248; and Garrett, C. E., Jiang, X., Prasad, K., Repic, O., Tetrahedron Letters (2002) 43, 4161. General procedures for deacetylation (i.e., conversion of intermediates 1e to 1f) may be found in Rapoport, H., Plattner, J. J., Gless, R. D., J. Am. Chem. Soc . (1972) 94, 8613
[0057] For a detailed preparation using the procedures described above, see the Example section below.
[0058] The hydroxy intermediate (1a) can be synthesized using the procedures described in Scheme II below.
[0059] The desired starting material (2a) may be purchased from a variety of chemical suppliers or prepared using standard chemical preparations as described in standard chemical synthesis books (e.g., Beilstein). The pyrazole ring may be built by first reacting the desired compound of Formula (2a) with dialkyloxalate (e.g., dimethyloxalate or diethyloxalate) in the presence of a strong base (e.g., lithium bis(trimethylsilyl)amide) in a aprotic solvent (e.g., tert-butyl methyl ether and tetrahydrofuran). The resultant enol (2b) may then be reacted with the desired hydrazine salt (2c) in a polar solvent (e.g., ethanol) followed by treatment with a strong base (e.g., alkali metal hydroxide). A hydroxy group may then be attached to the pyrazole ring by treating the compound of Formula (2d) with an alkyl lithium (e.g., hexyllithium, n-butyllithium, sec-butyllithium and tert-butyllithium) and trialkylborate (e.g., trimethylborate, triethylborate and triisopropylborate) followed by treatment with basic hydrogen peroxide.
[0060] Alternatively, the hydroxy intermediate (1a) can be prepared using the synthetic steps outlined in Scheme III below.
The keto ester intermediate (3a) can be prepared by condensing the desired acid chloride with 2,2-dimethyl-[1,3]dioxane-4,6-dione in the presence of a base (e.g., pyridine) in an aprotic solvent (e.g., methylene chloride) followed by heating at an elevated temperature in a protic solvent (e.g., ethanol). The hydrazono intermediate (3b) can then be prepared by treating the keto ester (3a) with the desired amine in the presence of sodium nitrate in an acidic medium (e.g., aqueous acetic acid). The bromo group may then be introduced using standard bromination procedures well-known to those skilled in the art. For example, intermediate (3b) can be treated with copper (II) bromide in an aprotic solvent (e.g., ethyl acetate and chloroform) at an elevated temperature. Cyclization of the bromo intermediate (3c) may then be accomplished by heating in a polar solvent (e.g., methanol) in the presence of sodium acetate. The hydroxy ester intermediate (3d) can then be hydrolyzed to the corresponding hydroxy carboxylic acid (1a) using conventional hydrolysis processes well-known to those skilled in the art. For example, the ester (3d) can be treated with a metal hydroxide (e.g., potassium hydroxide) in the presence of an aqueous protic solvent (e.g., methanol). For an example of a detailed preparation using the procedures described above, see the Example section below.
[0061] Conventional methods and/or techniques of separation and purification known to one of ordinary skill in the art can be used to isolate the compounds of the present invention, as well as the various intermediates related thereto. Such techniques will be well-known to one of ordinary skill in the art and may include, for example, all types of chromatography (high pressure liquid chromatography (HPLC), column chromatography using common adsorbents such as silica gel, and thin-layer chromatography), recrystallization, and differential (i.e., liquid-liquid) extraction techniques.
[0062] The compounds may be isolated and used per se or in the form of its pharmaceutically acceptable salt, solvate and/or hydrate. The term “salts” refers to inorganic and organic salts of a compound of the present invention. These salts can be prepared in situ during the final isolation and purification of a compound, or by separately reacting the compound with a suitable organic or inorganic acid or base and isolating the salt thus formed. Representative salts include the hydrobromide, hydrochloride, hydroiodide, sulfate, bisulfate, nitrate, acetate, trifluoroacetate, oxalate, besylate, palmitiate, pamoate, malonate, stearate, laurate, malate, borate, benzoate, lactate, phosphate, hexafluorophosphate, benzene sulfonate, tosylate, formate, citrate, maleate, fumarate, succinate, tartrate, naphthylate, mesylate, glucoheptonate, lactobionate, and laurylsulphonate salts, and the like. These may include cations based on the alkali and alkaline earth metals, such as sodium, lithium, potassium, calcium, magnesium, and the like, as well as non-toxic ammonium, quaternary ammonium, and amine cations including, but not limited to, ammonium, tetramethylammonium, tetraethylammonium, methylamine, dimethylamine, trimethylamine, triethylamine, ethylamine, and the like. See, e.g., Berge, et al., J. Pharm. Sci., 66, 1-19 (1977).
[0063] The compounds may contain asymmetric or chiral centers, and, therefore, exist in different stereoisomeric forms. It is intended that all stereoisomeric forms of the compounds as well as mixtures thereof, including racemic mixtures, form part of the present invention. In addition, the present invention embraces all geometric and positional isomers. For example, if a compound incorporates a double bond or a fused ring, both the cis- and trans-forms, as well as mixtures, are embraced within the scope of the invention.
[0064] Diastereomeric mixtures can be separated into their individual diastereoisomers on the basis of their physical chemical differences by methods well known to those skilled in the art, such as by chromatography and/or fractional crystallization. Enantiomers can be separated by converting the enantiomeric mixture into a diastereomeric mixture by reaction with an appropriate optically active compound (e.g., chiral auxiliary such as a chiral alcohol or Mosher's acid chloride), separating the diastereoisomers and converting (e.g., hydrolyzing) the individual diastereoisomers to the corresponding pure enantiomers. Also, some of the compounds of the present invention may be atropisomers (e.g., substituted biaryls) and are considered as part of this invention. Enantiomers can also be separated by use of a chiral HPLC column.
[0065] The compounds may exist in unsolvated as well as solvated forms with pharmaceutically acceptable solvents such as water, ethanol, and the like, and it is intended that the invention embrace both solvated and unsolvated forms.
[0066] It is also possible that the intermediates and compounds may exist in different tautomeric forms, and all such forms are embraced within the scope of the invention. The term “tautomer” or “tautomeric form” refers to structural isomers of different energies which are interconvertible via a low energy barrier. For example, proton tautomers (also known as prototropic tautomers) include interconversions via migration of a proton, such as keto-enol and imine-enamine isomerizations. A specific example of a proton tautomer is the imidazole moiety where the proton may migrate between the two ring nitrogens. Valence tautomers include interconversions by reorganization of some of the bonding electrons.
[0067] The present invention also embraces isotopically-labeled compounds (including intermediates) which are identical to those recited herein, but for the fact that one or more atoms are replaced by an atom having an atomic mass or mass number different from the atomic mass or mass number usually found in nature. Examples of isotopes that can be incorporated into the intermediates or compounds of the invention include isotopes of hydrogen, carbon, nitrogen, oxygen, phosphorus, sulfur, fluorine, iodine, and chlorine, such as 2 H, 3 H, 11 C, 13 C, 14 C, 13 N, 15 N, 15 O, 17 O, 18 O, 31 P, 32 P, 35 S, 18 F, 123 I, 125 I and 36 Cl, respectively.
[0068] The preparation of certain isotopically-labeled compounds (e.g., those labeled with 3 H and 14 C) is useful in compound and/or substrate tissue distribution assays. Tritiated (i.e., 3 H) and carbon-14 (i.e., 14 C) isotopes are particularly preferred for their ease of preparation and detectability. Further, substitution with heavier isotopes such as deuterium (i.e., 2 H) may afford certain therapeutic advantages resulting from greater metabolic stability (e.g., increased in vivo half-life or reduced dosage requirements) and hence may be preferred in some circumstances. Positron emitting isotopes such as 15 O, 13 N, 11 C, and 18 F are useful for positron emission tomography (PET) studies to examine substrate receptor occupancy. Isotopically labeled compounds of the present invention can generally be prepared by following procedures analogous to those disclosed in the Schemes and/or in the Examples herein below, by substituting an isotopically labeled reagent for a non-isotopically labeled reagent.
[0069] Compounds made by the process of the present invention are useful for treating diseases, conditions and disorders modulated by cannabinoid receptor antagonists.
[0070] Preliminary investigations have indicated that the following diseases, conditions, and/or disorders are modulated by cannabinoid receptor antagonists: eating disorders (e.g., binge eating disorder, anorexia, and bulimia), weight loss or control (e.g., reduction in calorie or food intake, and/or appetite suppression), obesity, depression, atypical depression, bipolar disorders, psychoses, schizophrenia, behavioral addictions, suppression of reward-related behaviors (e.g., conditioned place avoidance, such as suppression of cocaine- and morphine-induced conditioned place preference), substance abuse, addictive disorders, impulsivity, alcoholism (e.g., alcohol abuse, addiction and/or dependence including treatment for abstinence, craving reduction and relapse prevention of alcohol intake), tobacco abuse (e.g., smoking addiction, cessation and/or dependence including treatment for craving reduction and relapse prevention of tobacco smoking), dementia (including memory loss, Alzheimer's disease, dementia of aging, vascular dementia, mild cognitive impairment, age-related cognitive decline, and mild neurocognitive disorder), sexual dysfunction in males (e.g., erectile difficulty), seizure disorders, epilepsy, inflammation, gastrointestinal disorders (e.g., dysfunction of gastrointestinal motility or intestinal propulsion), attention deficit disorder (ADD including attention deficit hyperactivity disorder (ADHD)), Parkinson's disease, and type II diabetes.
[0071] Embodiments of the present invention are illustrated by the following Examples. It is to be understood, however, that the embodiments of the invention are not limited to the specific details of these Examples, as other variations thereof will be known, or apparent in light of the instant disclosure, to one of ordinary skill in the art.
EXAMPLES
[0072] Unless specified otherwise, reagents, solvents and starting materials are generally available from commercial sources such as Aldrich Chemicals Co. (Milwaukee, Wis.), Lancaster Synthesis, Inc. (Windham, N.H.), Acros Organics (Fairlawn, N.J.), Maybridge Chemical Company, Ltd. (Cornwall, England), Tyger Scientific (Princeton, N.J.), and AstraZeneca Pharmaceuticals (London, England).
General Experimental Procedures
[0073] NMR spectra were recorded on a Varian Unity™ 400 (available from Varian Inc., Palo Alto, Calif.) at room temperature at 400 MHz for proton. Chemical shifts are expressed in parts per million (δ) relative to residual solvent as an internal reference. The peak shapes are denoted as follows: s, singlet; d, doublet; t, triplet; q, quartet; m, multiplet; bs, broad singlet; 2s, two singlets. Atmospheric pressure chemical ionization mass spectra (APCI) were obtained on a Fisons™ Platform II Spectrometer (carrier gas: acetonitrile: available from Micromass Ltd, Manchester, UK). Chemical ionization mass spectra (CI) were obtained on a Hewlett-Packard™ 5989 instrument (ammonia ionization, PBMS: available from Hewlett-Packard Company, Palo Alto, Calif.). Electrospray ionization mass spectra (ES) were obtained on a Waters™ ZMD instrument (carrier gas: acetonitrile: available from Waters Corp., Milford, Mass.). Where the intensity of chlorine or bromine-containing ions are described, the expected intensity ratio was observed (approximately 3:1 for 35 Cl/ 37 Cl-containing ions and 1:1 for 79 Br/ 81 Br-containing ions) and the intensity of only the lower mass ion is given. In some cases only representative 1 H NMR peaks are given. MS peaks are reported for all examples. Optical rotations were determined on a PerkinElmer™ 241 polarimeter (available from PerkinElmer Inc., Wellesley, Mass.) using the sodium D line (λ=589 nm) at the indicated temperature and are reported as follows [α] D temp , concentration (c=g/100 ml), and solvent.
[0074] Column chromatography was performed with either Baker™ silica gel (40 μm; J. T. Baker, Phillipsburg, N.J.) or Silica Gel 50 (EM Sciences™, Gibbstown, N.J.) in glass columns or in Flash 40 Biotage™ columns (ISC, Inc., Shelton, Conn.) under low nitrogen pressure.
[0075] The following section provides representative examples of useful starting materials and/or intermediates that may be used in the process of the present invention.
Starting Materials and/or Intermediates
Preparation of 4-(4-chlorophenyl)-2-hydroxy-4-oxo-but-2-enoic acid ethyl ester lithium salt (I-2b)
[0076]
[0077] Lithium bis(trimethylsilyl)-amide (149 ml: 1.0 M in tetrahydrofuran, 149 mmol) was added to tert-butyl methyl ether (350 ml) at room temperature. The resulting solution was then cooled to −75° C. 1-(4-Chlorophenyl)ethanone (23.28 g, 150.6 mmoles) was added as a solution in 23 ml of tert-butyl methyl ether over 3 minutes while keeping the internal temperature less than −70° C. The reaction solution was allowed to stir for 1 hour at −75° C., then diethyl oxalate (22.0 g, 150 mmol) was added neat over 5 minutes while keeping the internal temperature less than −70° C. The clear dark orange reaction solution was then warmed to room temperature over 4 hours. (The product began to precipitate at −3° C.) The reaction was allowed to stir for 15 hours at room temperature, followed by isolation of the precipitated product by filtration. The filtercake was washed with 100 ml of room temperature tert-butyl methyl ether and then dried at 60° C. in vacuo for 1 hour to give 4-(4-chlorophenyl)-2-hydroxy-4-oxo-but-2-enoic acid ethyl ester lithium salt I-2b (36.72 g, 94%) as a powdery yellow solid.
[0078] 1 H-NMR (DMSO-d 6 ) δ 7.80 (d, 1.94H, J=8.7 Hz), 7.66 (d, 0.06H, J=8.7 Hz), 7.43 (d, 1.94H, J=8.7 Hz), 7.31 (d, 0.06H, J=8.3 Hz), 6.37 (s, 0.97H), 5.22 (s, 0.03H), 4.10 (q, 1.94H, J=7.05 Hz), 4.00 (q, 0.06H, J=7.05 Hz), 1.20 (t, 2.91H, J=7.05 Hz), 1.15 (t, 0.09H, J=7.05 Hz). Shows a 97:3 mixture of geometric isomers. Mass Spec (ESI): M+1=255.2 (mass of neutral compound)
Preparation of 1-(2-chlorophenyl)-5-(4-chlorophenyl)-1H-pyrazole-3-carboxylic acid (I-2d)
[0079]
[0080] 4-(4-Chlorophenyl)-2-hydroxy-4-oxo-but-2-enoic acid ethyl ester lithium salt I-2b (30.26 g, 116 mmoles) was suspended in 242 ml of ethanol. 2-Chlorophenylhydrazine hydrochloride (20.88 g, 116 mmoles) was added portionwise as a solid over 45 minutes while maintaining an internal temperature between 30-40° C. The reaction mixture went from a yellow suspension to a dark orange suspension. The reaction was allowed to stir for 3 hours while maintaining an internal temperature between 25-35° C. An aqueous potassium hydroxide solution (148 ml of 1.8 M solution, 266 mmoles) was added over 20 minutes while maintaining an internal temperature between 20-30° C. The reaction mixture was held for 2.5 hours. Within 30 minutes of potassium hydroxide solution addition, the reaction turned an almost clear, very dark rust orange in color. Aqueous hydrochloric acid (85 ml of 3.9 M solution, 331 mmoles) was added over 15 minutes while maintaining the reaction temperature between 20-30° C. The product precipitated during hydrochloric acid addition. The precipitated product was granulated for 16 hours at room temperature. The crude product was isolated by filtration and the filtercake was washed with 150 ml of water. The filtercake was a yellowish orange solid. After air-drying for 30 minutes, the filtercake was suspended in 480 ml of methanol. The suspension was heated to reflux to give a clear dark orange solution (all solids in solution within 1 hour of reaching reflux) and then held at reflux for 8 hours. The solution was cooled over 4 hours to room temperature, during which time product had precipitated from solution. The reaction mixture was held at room temperature for 10 hours, followed by cooling to 0° C., and stirring for 1.5 hours. Collection of the precipitate by filtration, washing the resulting filtercake with 150 ml of ice-chilled methanol, and drying at 60° C. in vacuo for 3 hours afforded 1-(2-chlorophenyl)-5-(4-chlorophenyl)-1H-pyrazole-3-carboxylic acid I-2d (29.28 g, 76%) as an off-white solid.
[0081] 1 H-NMR (CD 3 CN): δ 7.58-7.45 (m, 4H), 7.31 (d, 2H, J=8.7 Hz), 7.21 (d, 2H, J=8.7 Hz), 7.10 (s, 1H). Mass Spec (ESI): M+1=333.2
Preparation of 1-(2-chlorophenyl)-5-(4-chlorophenyl)-4-hydroxy-1H-pyrazole-3-carboxylic acid (I-1a)
[0082]
[0083] 1-(2-Chlorophenyl)-5-(4-chlorophenyl)-1H-pyrazole-3-carboxylic acid I-2d (628.1 g, 1.88 mol) was dissolved in tetrahydrofuran (11 liters) to give a clear light orange solution. This solution was cooled to −78° C. followed by the addition of hexyllithium (2.0 M solution in hexanes, 2.07 liters, 4.14 mol) over a period of 2 hours while keeping internal temperature less than −70° C. During the addition of the first equivalent of hexyllithium, the reaction solution remained clear orange, then during addition of a second equivalent of hexyllithium, the reaction solution turned brown and then very dark green. The reaction mixture was held for 20 minutes at −74° C., then warmed to −50° C. over 30 minutes and held for an additional 1 hour at this temperature. The reaction was cooled back to less than −70° C., followed by the addition of neat trimethylborate (238 g, 2.01 moles) over 3 minutes while keeping the temperature less than −68° C. The reaction solution was then warmed to room temperature over 3 hours. The reaction remained very dark green until reaching room temperature after which it turned clear dark orange. Aqueous sodium hydroxide (750 ml of 3.0 M, 2.25 mol) was added over 5 minutes to crude reaction solution while maintaining an internal temperature of 10-15° C. Concentrated aqueous hydrogen peroxide (253 g, 30 wt %, 2.01 moles) was then added over a period of 30 minutes while maintaining an internal temperature between 10-20° C. The reaction was allowed to warm to room temperature and stirred for 3.5 hours. Water (3 liters) was added followed by addition of concentrated aqueous hydrochloric acid (545 ml, 12.1 M, 6.59 mol) over 15 minutes while maintaining a temperature of 20-30° C. The pH of the crude reaction solution was approximately 2.5. The tetrahydrofuran and aqueous layers were separated and the aqueous layer was extracted with 4 liters of tert-butyl methyl ether. The tetrahydrofuran and tert-butyl methyl ether layers were combined, washed with 4 liters of brine, and dried over 2.5 Kg of Na 2 SO 4 . The crude solution was concentrated in vacuo to a thick orange oil containing some fine solids. The crude orange oil was then added to 5 liters of methanol, causing a bright yellow precipitate to crystallize from solution. The precipitated product was granulated for 20 hours at room temperature followed by cooling to 0° C. and stirring for 1 hour. The crude product was isolated by filtration and the resulting filtercake was washed with 1 liter of ice-chilled methanol. The filtercake was air-dried for 18 hours. This crude product (390 g) was suspended in 2.1 liters of 2-propanol followed by heating to reflux to give a clear yellow/orange solution. Solution held at reflux for 1 hour, then cooled over a period of 5 hours to 3° C. and stirred for 1 hour. The recrystallized product was isolated by filtration and the resulting filtercake was washed with 900 ml of ice-chilled 2-propanol, followed by air-drying for 18 hours. The product was oven-dried for 18 hours at 60° C. and 10 mm to afford 1-(2-chlorophenyl)-5-(4-chlorophenyl)-4-hydroxy-1H-pyrazole-3-carboxylic acid I-1a (282.9 g, 43%) as an off-white solid.
[0084] 1 H-NMR (CD 3 CN): δ 7.55-7.44 (m, 4H), 7.31 (d, 2H, J=8.7 Hz), 7.20 (d, 2H, J=8.7 Hz). Mass Spec (ESI): M+1=349.2
Preparation of Starting material 2-(2,2-Difluoropropylamino)-ethanol (Sm-1c)
[0085]
[0086] Two 22 liter 3-neck round-bottomed flasks equipped with a mechanical stirrer, thermometer, nitrogen inlet and drying tubes were each charged with ethyl pyruvate (2350 g, 20.24 mol) and then cooled to −15 to −10° C. using a dry ice/acetone bath. [Bis(2-methoxyethyl)amino]sulfur trifluoride (DeoxoFluor™; 3731 ml, 20.24 mol) was then added to each of the flasks while maintaining the temperature less than −5° C. The reaction mixtures were then stirred at a temperature less than 30° C. until no more starting material was present by gas chromatography (GC). Each reaction mixture was then added to a stirred mixture of water (16.6 Kg)/ice(16.6 Kg) and sodium bicarbonate (3.3 Kg) in a 30 gallon crock over approximately 30 minutes. The aqueous mixtures were then stirred overnight to room temperature. The two layers were separated for each crude reaction mixture and the aqueous layers were split in half and each extracted with methylene chloride (3× 2 liters). The methylene chloride layers were combined (24 L total) and then washed with brine (1× 2 liters) followed by treatment with charcoal and dried over magnesium sulfate. The solvent was removed and the liquid residue distilled at 60-110° C. at atmospheric pressure to yield 5557 g (99.4%) of 2,2-difluoro-propionic acid ethyl ester.
[0087] A 12 liter 3-necked round-bottomed flask equipped with a mechanical stirrer, thermometer, addition funnel, condenser, nitrogen inlet and drying tube was charged with 2,2-difluoro propionic acid ethyl ester from above (5557 g) and heated to reflux (approximately 53° C.). Ethanolamine (2457 g, 4023 mol) was added to the heated solution over approximately 1 hour while maintaining a gentle reflux. After the addition was complete, the mixture was refluxed for an additional hour (reaction was deemed complete by GC analysis). Ethanol was removed from the reaction mixture by vacuum distillation. The crude product was then crystallized by diluting with toluene (1:1) and followed by cooling to −20° C. After solids started to precipitate out of solution, hexane (4 ml/1 ml) was added and the mixture was allowed to stir for 2 additional hours at −20° C., followed by holding the mixture in a freezer overnight. The solids were filtered through a polypad and washed with freezer cold hexane (2× 1 liter). The isolated solids were then dried in vacuo with no heat to give 3000 g (49%) of 2,2-difluoro-N-(2-hydroxyethyl)-propionamide as a low melting solid (mp=36-38° C.).
[0088] Two 50 liter 3-necked round-bottomed flasks were each equipped with a mechanical stirrer, thermometer, addition funnel, nitrogen inlet and a drying tube. Tetrahydrofuran (THF: 9 liters) was charged to each flask and then cooled to −5° C. Lithium aluminum hydride (734.5 g, 31.18 mol) was added to each reaction flask portionwise while monitoring gas evolution and maintaining the temperature less than 25° C. using an ice/methanol bath. After the additions were complete, the reaction mixture was cooled to 0° C. and 2,2-difluoro-N-(2-hydroxyethyl)propanamide from above (1500 g, 9.79 mol) dissolved in THF (9 liters) was added to each reaction mixture while maintaining the temperature less than 30° C. After about 48-60 hours, the mixtures were cooled to 0° C. using an ice/methanol bath and quenched with a 10% sodium hydroxide solution (3.2 liters) while maintaining the temperature between 0-30° C. The reaction mixtures were filtered through an 18 inch (45.72 cm) crock funnel using a polypad. The solids from each reaction were slurried with methylene chloride (3× 7 liters) and filtered. All of the filtrates were then combined and concentrated to dryness in vacuo. The residue was distilled and the product collected between 95-100° C. at 25 mm Hg. All of the material collected was redistilled and the product (2-[(2,2-difluoropropyl)amino]ethan-1-ol Sm-1c was collected between 85° C./17 mm Hg and 102° C./25 mm Hg.
[0089] The following describes an alternative procedure for the preparation of Intermediate 5-(4-chlorophenyl)-1-(2-chlorophenyl)-4-hydroxy-1H-pyrazole-3-carboxylic Acid (I-1a).
Preparation of Intermediate 4-(4-Chlorophenyl)-3-oxo-butyric Acid Ethyl Ester (I-3a)
[0090]
[0091] Pyridine (105 ml) was added dropwise over a 30-minute period o a cooled (0° C.) to a stirred solution of 2,2-dimethyl-1,3-doxane-4,6-dione (78.5 g, 0.54 mol) in dichloromethane (200 ml). A solution of 4-chlorophenylacetyl chloride (100 g, 0.53 mol) in dichloromethane (150 ml) was then added dropwise. The reaction mixture was stirred for 1 hour at 0° C., The cooling bath was removed, and stirring was continued for an additional 2 hours. The reaction mixture was poured over 2N hydrochloric acid (aq.)/ice, layers separated and the aqueous layer washed with dichloromethane (2×150 ml). Combined organic layers were washed with 2N hydrochloric acid (aq.) (2×150 ml), brine, dried (Na 2 SO 4 ) and concentrated in vacuo to afford a solid.
[0092] The material obtained above was slurried in ethanol (1 liter), heated to reflux for 3 hours, then cooled and concentrated in vacuo. The oily residue was fractionally-distilled under vacuum to afford the title compound (I-3a) as a clear oil, 108 g.
Preparation of Intermediate 4-(4-Chlorophenyl)-2-[(2-chlorophenyl)-hydrazono]-3-oxobutyric Acid Ethyl Ester (I-3b)
[0093]
[0094] A solution of sodium nitrite (3.4 g, 50.4 mmol) in water (15 ml) was added dropwise over an hour period to a cooled (0° C.), stirred solution of 2-chloroaniline (6.4 g, 50.4 mmol) in acetic acid (50 ml)/water (7 ml). Then a solution of 4-(4-chloro-phenyl)-3-oxo-butyric acid ethyl ester I-3a (10 g, 42 mmol) in acetic acid (30 ml) was added dropwise over a 30-minutes period to produce an orange slurry (20 ml of water added to aid stirring). After an additional hour, the mixture was filtered, solids washed with water and air-dried. Solids slurried in ethanol (75 ml) for 30 minutes, filtered, solids washed with methanol and dried in vacuo to afford the title compound (I-3b) as an orange solid, 11.0 g.
Preparation of 4-Bromo-4-(4-chlorophenyl)-2-[(2-chlorophenyl)-hydrazono]-3-oxobutyric Acid Ethyl Ester (I-3c)
[0095]
[0096] A stirred slurry of 4-(4-chlorophenyl)-2-[(2-chlorophenyl)-hydrazono]-3-oxobutyric acid ethyl ester I-3b (10.0 g, 26 mmol) and copper (II) bromide (13.4 g, 59.8 mmol) in ethyl acetate (100 ml)/chloroform (100 ml) was heated at 60° C. for 3 hours. The reaction mixture was cooled and filtered through diatomaceous earth followed by washing with chloroform. The filtrate was diluted with dichloromethane, washed with water, brine, dried (Na 2 SO 4 ) and concentrated in vacuo to afford the title compound (I-3c) as a red oil, 12.1 g.
Preparation of intermediate 5-(4-Chlorophenyl)-1-(2-chlorophenyl)-4-hydroxy-1H-pyrazole-3-carboxylic Acid Ethyl Ester (I-3d)
[0097]
[0098] A mixture of 4-bromo-4-(4-chloro-phenyl)-2-[(2-chloro-phenyl)-hydrazono]-3-oxo-butyric acid ethyl ester I-3c (12.1 g, 26 mmol) and sodium acetate (10.8 g, 130 mmol) in methanol (100 ml) was heated at reflux for 4 hours, cooled, and then concentrated in vacuo. The residue was partitioned between ethyl acetate and water. The organic layer was washed with brine, dried (Na 2 SO 4 ) and concentrated in vacuo to afford a solid. A slurry of this material in cyclohexane was heated to reflux and allowed to stir at ambient temperature for 2 hours and then filtered to afford the title compound (I-3d) as a yellow solid (I-1d), 6.5 g.
Preparation of Intermediate 5-(4-chlorophenyl)-1-(2-chlorophenyl)-4-hydroxy-1H-pyrazole-3-carboxylic Acid (I-1a)
[0099]
[0100] Aqueous potassium hydroxide (200 ml, 3.18 M, 636 mmol) was diluted with 1 liter of methanol followed by portionwise addition of 1-(2-chlorophenyl)-5-(4-chlorophenyl)-4-hydroxy-1H-pyrazole-3-carboxylic acid ethyl ester I-3d (100 g, 266 mmol) as a solid. Initially, a clear dark orange solution formed, but solids quickly precipitated back out of solution. The reaction mixture was then heated to reflux (a clear dark orange solution was obtained at 55° C.). The reaction was held at reflux (70° C.) for 4 hours, followed by cooling to room temperature (a small amount of precipitated out of solution). Another 1 liter of methanol was added (more precipitate formed) followed by 260 ml of water (a clear dark orange solution). Concentrated aqueous hydrochloric acid was added (57 ml, 12.1 M, 690 mmol) over 10 minutes, keeping the temperature between 20-30° C. (pH˜3). A precipitate began to come out of solution after HCl addition was 70% complete. The mixture was stirred for 1.5 hours at room temperature, then the precipitate was collected by filtration, and the resulting filtercake washed with 500 ml of room temperature 1:1, methanol:water, followed by washing with 500 ml of water. Collected solids were air-dried for 2 hours followed by drying at 60° C. and 1 mm for 15 hours to afford 1-(2-chlorophenyl)-5-(4-chlorophenyl)-4-hydroxy-1H-pyrazole-3-carboxylic acid I-1a (90.8 g, 98%) as an off-white solid.
Example 1
Preparation of 3-(4-Chloro-phenyl)-2-(2-chloro-phenyl)-7-(2,2-difluoro-propyl)-6,7-dihydro-2H,5H-4-oxa-1,2,7-triaza-azulen-8-one (1A-1)
[0101]
Preparation of 4-Acetoxy-1-(2-chlorophenyl)-5-(4-chlorophenyl)-1H-pyrazole-3-carboxylic acid (I-1b)
[0102]
[0103] 1-(2-Chlorophenyl)-5-(4-chlorophenyl)-4-hydroxy-1H-pyrazole-3-carboxylic acid I-1a (572.0 g, 1.64 mol) was combined with 8 liters of methylene chloride to give an off-white suspension. N,N-Diisopropylethylamine (427.9 g, 3.29 mol) was added over 15 minutes while keeping the temperature between 20-25° C. A clear yellow solution resulted. Acetic anhydride (334.5 g, 3.24 mol) was added over 5 minutes keeping the temperature between 20-25° C. The reaction was stirred at room temperature for 16 hours. The crude reaction solution was washed twice with 4 liter portions of 0.5 M citric acid and once with 4 liters of brine. The crude solution was concentrated in vacuo to a total volume of 1 liter. This milky suspension was then added to 4 liters of hexanes causing the desired product to precipitate instantly. The solids were granulated for 30 minutes and then collected by filtration. The filtercake was rinsed with 3 liters of hexanes and then air-dried for 16 hours. The isolated product was then further dried at 60° C. and 8 mm for 2 hours. 4-Acetoxy-1-(2-chlorophenyl)-5-(4-chlorophenyl)-1H-pyrazole-3-carboxylic acid I-1b (601.6 g, 94%) was isolated as a powdery, off-white solid.
[0104] 1 H-NMR (CD 2 Cl 2 ): δ 7.50 (d, 1H, J=7.0 Hz), 7.47-7.37 (m, 3H), 7.28 (d, 2H, J=8.7 Hz), 7.12 (d, 2H, J=8.7 Hz), 2.26 (s, 3H). Mass Spec (ESI): M+1=391.2
Preparation of Acetic acid 1-(2-chlorophenyl)-5-(4-chlorophenyl)-3-[(2,2-difluoro-propyl)-(2-hydroxyethyl)-carbamoyl]-1H-pyrazol-4-yl ester (I-1d)
[0105]
[0106] 4-Acetoxy-1-(2-chlorophenyl)-5-(4-chlorophenyl)-1H-pyrazole-3-carboxylic acid I-1b (581.0 g, 1.48 mol) was dissolved in 10 liters of methylene chloride to give a pale yellow, slightly opaque solution. The solution was filtered through Celite® to give a clear green colored solution. 2-Chloro-4,6-dimethoxy-1,3,5-triazine (296.8 g, 1.64 mol) was added in one portion as a solid at room temperature to give an opaque suspension (addition is slightly endothermic). 4-Methylmorpholine (182.9 g, 1.80 mol) was added over 15 minutes while keeping the temperature between 18-22° C. (reaction returned to being yellow in color). The reaction was allowed to stir for 3 hours at room temperature, then 2-(2,2-difluoropropylamino)-ethanol Sm-1c (228.3 g, 1.64 mol) was added neat over 10 minutes while keeping the temperature between 20-25° C. The reaction mixture was stirred for 15 hours, then washed twice with 6 liter portions of 10% citric acid and once with 5 liters of brine. The crude product solution was concentrated in vacuo to a thick orange oil and then reconstituted in 4 liters of isopropyl ether. After removing 1 liter of distillates, precipitate began to form. Isopropyl ether (1.5 liters) was added to the crude product suspension and then the mixture was stirred at room temperature for 1 hour. The precipitated solids were collected by filtration and the resulting filtercake was rinsed with 2 liters of room temperature isopropyl ether, followed by air-drying for 16 hours. Acetic acid 1-(2-chlorophenyl)-5-(4-chlorophenyl)-3-[(2,2-difluoro-propyl)-(2-hydroxyethyl)-carbamoyl]-1H-pyrazol-4-yl ester I-1d (603.0 g, 78%) was isolated as a granular off-white solid.
[0107] 1 H-NMR (CD 2 Cl 2 ): δ 7.50-7.31 (m, 4H), 7.28 (d, 2H, J=8.3 Hz), 7.14 (d, 2H, J=8.7 Hz), 4.41-3.41 (m, various rotamers, 7H), 2.21 (s, 3H), 1.65 (t, 3H, J HF =19.5 Hz).
[0108] Mass Spec (ESI): M+1=512.2
Preparation of Acetic acid 3-[(2-chloroethyl)-(2,2-difluoropropyl)-carbamoyl]-1-(2-chlorophenyl)-5-(4-chlorophenyl)-1H-pyrazol-4-yl-ester (I-1e)
[0109]
[0110] Method A: Acetic acid 1-(2-chlorophenyl)-5-(4-chlorophenyl)-3-[(2,2-difluoro-propyl)-(2-hydroxy-ethyl)-carbamoyl]-1H-pyrazol-4-yl ester I-1d (580.6 g, 1.12 mol) was dissolved in 10 liters of methylene chloride to give a clear pale yellow solution. After cooling to 0° C., methanesulfonyl chloride (142.4 g, 1.21 mol) was added neat over 5 minutes, followed by addition of neat N,N-diisopropylethylamine (167.9 g, 1.29 mol) over 25 minutes, while keeping the temperature less than 5° C. After stirring 20 minutes at <5° C., the reaction was warmed to room temperature and stirred for 14 hours. The crude reaction solution was washed twice with 4.5 liter portions of 10% citric acid and once with 4 liters of brine. The crude product solution was concentrated in vacuo to give a crude solid, then 2 liters of methanol was added followed by stirring for 1 hour. About half of the crude solid had dissolved in and then crystallized from the methanol. This material was collected by filtration and the resulting filtercake was rinsed with 300 ml of room temperature methanol. This first crop of material was dried at 50° C. and 10 mm for 2 hours to give 245.2 g, 41.2% of the title compound as an off-white solid. The crude solid that had not dissolved in and crystallized from methanol was redissolved in 1 liter of methylene chloride, then concentrated to a viscous brownish oil. The methanol mother liquor left over from the first crop was concentrated to a total volume of 800 ml and was then combined with the viscous brownish oil. This mixture was warmed in a 40° C. waterbath until a clear solution was obtained, then the resulting solution was cooled to 0° C. and stirred for 30 minutes, resulting in product precipitation. The precipitate was collected by filtration, and the resulting filtercake was washed with 200 ml of ice-chilled methanol, followed by air-drying for 16 hours. The second crop material (290.9 g, 48.8%) was isolated as an off-white solid. The overall combined yield of first and second crops of acetic acid 3-[(2-chloroethyl)-(2,2-difluoropropyl)-carbamoyl]-1-(2-chlorophenyl)-5-(4-chlorophenyl)-1H-pyrazol-4-yl-ester I-1e was 536.1 g (90%).
[0111] Method B: 1-(2-Chlorophenyl)-5-(4-chlorophenyl)-1H-pyrazole-3-carboxylic acid I-2c (90.8 g, 260 mmol) was dissolved in 1.7 liters of methylene chloride, giving an off-white suspension. 4-Methylmorpholine (58.5 g, 576 mmol) was added, giving a clear yellow solution, followed by addition of acetyl chloride (22.6 g, 284 mmol) over 10 minutes while maintaining a temperature between 20-30° C. The reaction was stirred for 7 hours at room temperature, then cooled to 0° C. 2-(2,2-Difluoropropylamino)-ethanol (39.8 g, 286 mmol) was added neat over 1 minute followed by addition of 2-Chloro-4,6-dimethoxy-1,3,5-triazine (49.0 g, 271 mmol) portionwise as a solid over 1 minute. The reaction was allowed to slowly warm to room temperature over a period of 5 hours, followed by stirring for 12 hours at room temperature. The crude reaction solution was washed twice with 900 ml portions of 0.5 M citric acid and once with 900 ml of brine. Residual water was azeotropically removed through two cycles concentrating off methylene chloride and then adding more methylene chloride. The final crude methylene chloride solution volume was 1.2 liters. This solution was cooled to −2° C. followed by addition of neat methanesulfonyl chloride (36.0 g, 311 mmol) and then addition of neat N,N-diisopropylethylamine (42.1 g, 324 mmol) over a 10 minute period while maintaining a reaction temperature less than 10° C. The reaction solution was warmed to room temperature over 1 hour, followed by stirring for 20 hours, then washing the methylene chloride solution twice with 800 ml portions of 0.5 M citric acid and once with 800 ml brine. Product rich methylene chloride layer was clear dark orange in appearance (˜1.3 liters total volume). Crude solution was concentrated in vacuo to ˜300 ml, followed by addition of 1 liter of methanol. Resulting solution was concentrated in vacuo in a 30° C. waterbath by removing 900 ml of distillates. Another 800 ml portion of methanol was added followed by a final concentration in vacuo (30° C. waterbath) to remove 700 ml of distillates. The final total volume was ˜500 ml. The product rich concentrated solution was held at room temperature for 1 hour (solution was initially hazy, dark orange in appearance, then solids precipitated after ˜15 minutes). The mixture was cooled to −10° C. and stirred for 1 hour while maintaining temperature less than 0° C. The precipitated solids were collected by filtration, and the resulting filtercake was washed with 50 ml of ice-chilled methanol, followed by air-drying for 15 hours. The isolated solids were further dried at 60° C. and 1 mm for 2 hours (loss on drying was only 0.4 g) to give acetic acid 3-[(2-chloroethyl)-(2,2-difluoropropyl)-carbamoyl]-1-(2-chlorophenyl)-5-(4-chlorophenyl)-1H-pyrazol-4-yl-ester I-1e (104.0 g, 75%) as a white solid.
[0112] 1 H-NMR (CD 2 Cl 2 ): δ 7.49-7.47 (m, 1H), 7.44-7.40 (m, 1H), 7.37-7.33 (m, 2H), 7.28 (d, 2H, rotamers, J=8.7 Hz), 7.14 (d, 2H, rotamers, J=8.7 Hz), 4.46 (t, 0.72H, J cannot be determined), 4.14 (t, 1.28H, J cannot be determined), 3.97 (t, 1.28H, J HF =13.0 Hz), 3.87 (t, 0.72H, J=6.4 Hz), 2.22 (s, 1.08H), 2.20 (s, 1.92H), 1.62 (t, 3H, rotamers, J HF =19.5 Hz). Two major rotamers present in a ˜1.7:1 ratio.
[0113] Mass Spec (ESI): M+1=530.2
Preparation of 1-(2-chlorophenyl)-5-(4-chlorophenyl)-4-hydroxy-1H-pyrazole-3-carboxylic acid (2-chloroethyl)-(2,2-difluoropropyl)-amide (I-1f)
[0114]
[0115] Acetic acid 3-[(2-chloroethyl)-(2,2-difluoropropyl)-carbamoyl]-1-(2-chlorophenyl)-5-(4-chlorophenyl)-1-H-pyrazol-4-yl-ester I-1e (3.55 g, 6.69 mmol) was dissolved in 90 ml of methanol with warming in a 40° C. waterbath to give a clear colorless solution. The resulting solution was cooled to 0° C. (still a clear, colorless solution), followed by addition of K 2 CO 3 (1.02 g, 7.31 mmol) in one portion as a solid (reaction mixture goes from colorless to yellow). The reaction was stirred for 30 minutes at 0° C. followed by addition of concentrated hydrochloric acid (1.2 ml of 12.1 M, 14.5 mmol). Upon neutralization, the reaction turned colorless and clear, then product began to precipitate. The reaction was warmed to room temperature, then 45 ml of water was added, followed by stirring for 2.5 hours. The precipitated solids were collected by filtration and the resulting filtercake was washed with 50 ml of room temperature 2:1, methanol:water. The collected solids were dried at 50° C. in vacuo for 1 hour to give 1-(2-chlorophenyl)-5-(4-chlorophenyl)-4-hydroxy-1H-pyrazole-3-carboxylic acid (2-chloroethyl)-(2,2-difluoropropyl)-amide I-1f (2.86 g, 87%) as a white solid.
[0116] 1 H-NMR (CD 2 Cl 2 ): δ 9.67 (s, 0.52H), 9.57 (s, 0.48H), 7.51-7.48 (m, 1H), 7.46-7.41 (m, 1H), 7.39-7.31 (m, 2H), 7.24 (d, 2H, rotamers, J=8.7 Hz), 7.17 (d, 2H, rotamers, J=8.7 Hz), 4.75 (t, 0.52H, J HF =13 Hz), 4.47 (t, 0.48H, J=6 Hz), 4.08 (t, 0.48H, J HF =13 Hz), 3.94 (t, 0.52H, J=6 Hz), 3.84-3.79 (m, 2H), 1.66 (t, 1.44H, J HF =19.3 Hz), 1.59 (t, 1.56H, J HF =19.1 Hz). Two major rotamers present in a ˜1.07:1 ratio.
[0117] Mass Spec (ESI): M+1=488.2
Preparation of 3-(4-Chlorophenyl)-2-(2-chlorophenyl)-7-(2,2-difluoropropyl)-6,7-dihydro-2H,5H-4-oxa-1,2,7-triaza-azulen-8-one (I-1A)
[0118]
[0119] Acetic acid 3-[(2-chloroethyl)-(2,2-difluoropropyl)-carbamoyl]-1-(2-chlorophenyl)-5-(4-chlorophenyl)-1H-pyrazol-4-yl-ester I-1f (513.0 g, 0.97 mol) was suspended in 9.7 liter of ethanol (a off-white suspension). Cesium carbonate (348.0 g, 1.07 mol) was added portionwise as a solid over 2 minutes while maintaining an internal temperature between 21-27° C. Upon Cs 2 CO 3 addition, the reaction mixture turned pale yellow (still a suspension). The reaction was allowed to stir at room temperature for 19 hours, then the crude reaction mixture was filtered through Celite® to remove insoluble solids, giving a clear dark yellow filtrate. The Celite® filtercake was washed with 2 liters of ethanol. The crude product solution was concentrated in vacuo and gave a yellow solid. This solid was reconstituted in 7 liters of methylene chloride and the resulting mixture was washed once with 5 liters of half saturated aqueous NH 4 Cl and once with 4 liters of brine. The product rich methylene chloride layer was concentrated in vacuo to a total volume of 2.5 liters. The methylene chloride layer was clear and dark reddish in color. The product rich methylene chloride solution was treated with 105 g of Darco, followed by stirring at reflux for 30 minutes. After cooling, the Darco was filtered off by passing the solution through Celite®. The crude product solution was clear dark orange in appearance. The crude product filtrate was concentrated in vacuo to a total volume of 1.1 liters. This product rich methylene chloride solution was added over 20 minutes to 5 liters of cyclohexane while maintaining a reaction pot temperature of 50-60° C. Halfway through the methylene chloride solution addition, precipitate came out of solution. After complete addition, the methylene chloride solvent was removed at atmospheric pressure (3.55 liters of distillates collected while simultaneously adding 2 liters of cyclohexane to refluxing solution) from the reaction mixture by heating to 79° C. (internal pot temperature) over a 2.5 hour period. Once the internal temperature reached the boiling point of cyclohexane, all of the methylene chloride had been displaced. The reaction mixture took on a very dark pink/purple coloration with white solids suspended. The reaction mixture was held at 79° C. for 10 minutes, cooled to 50° C. and then held for 13 hours, followed by cooling to 30° C. and holding for an additional 4 hours. The precipitated product was collected by filtration, and the resulting filtercake was washed with 3 liters of room temperature cyclohexane, followed by air-drying for 3.5 hours. The isolated solids were further dried at 50° C. and 2 mm for 15 hours (loss on drying was only 0.2 g) to give 3-(4-chlorophenyl)-2-(2-chlorophenyl)-7-(2,2-difluoropropyl)-6,7-dihydro-2H,5H-4-oxa-1,2,7-triaza-azulen-8-one 1-1A (321.3 g, 73%) as an off-white solid.
Recrystallization of 3-(4-Chlorophenyl)-2-(2-chlorophenyl)-7-(2,2-difluoropropyl)-6,7-dihydro-2H,5H-4-oxa-1,2,7-triaza-azulen-8-one (1-1A)
[0120] 3-(4-Chlorophenyl)-2-(2-chlorophenyl)-7-(2,2-difluoropropyl)-6,7-dihydro-2H,5H-4-oxa-1,2,7-triaza-azulen-8-one 1-1A (5.00 g, 11.1 mmol) was dissolved in 20 ml of methylene chloride to give a clear orange solution. Darco KBB (0.5 g) was added followed by heating to reflux and stirring for 1 hour. After cooling, the Darco KBB was filtered off by passing the solution through Celite®, giving a clear light yellow filtrate. The Celite® filtercake was washed with 10 ml of methylene chloride. The eluent was concentrated in vacuo to give a total solution volume of ˜20 ml. The concentrated methylene chloride solution was then diluted with 150 ml of 2-propanol to give a clear pale yellow solution. Methylene chloride was removed from the resulting solution by atmospherically distilling off 71 ml of distillates as solution was heated from room temperature to 82° C. (boiling point of 2-propanol). The solution was then cooled over 3 hours from 82° C. to room temperature. Note: Solution became hazy around 34° C., followed by precipitate formation. The mixture was stirred at room temperature for 62 hours, then cooled to 0° C. and stirred for 2.5 hours before collecting the precipitate by filtration. The resulting filtercake was washed with 80 ml of ice-chilled 2-propanol, then air-dried for 1 hour. The recrystallized 3-(4-Chlorophenyl)-2-(2-chlorophenyl)-7-(2,2-difluoropropyl)-6,7-dihydro-2H,5H-4-oxa-1,2,7-triaza-azulen-8-one 1-1A (4.03 g, 81%) was isolated as a pure white crystalline solid.
[0121] 1 H-NMR (CD 2 Cl 2 ): δ 7.49-7.46 (m, 1H), 7.45-7.37 (m, 3H), 7.24 (d, 2H, rotamers, J=9.1 Hz), 7.16 (d, 2H, rotamers, J=8.7 Hz), 4.44 (dd, 2H, J=5.2 Hz, 1.9 Hz), 3.98 (t, 2H, J HF =13 Hz), 3.87 (t, 2H, J=3.7 Hz), 1.67 (t, 3H, J HF =19.1 Hz)
[0122] Mass Spec (ESI): M+1=452.2
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A process for preparing compounds of Formula (I) is described herein. The compounds have been shown to act as cannabinoid receptor ligands and are therefore useful in the treatment of disease linked to the mediation of the cannabinoid receptors in animals.
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BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to rail or freight car brake systems and, more particularly, to a brake cylinder limiting valves for an AAR-type freight car brake that prevents over-pressurization of the brake cylinder.
[0003] 2. Description of the Related Art
[0004] Control valves used in freight car brake systems, such as the DB-60 control valve manufactured by New York Air Brake Corporation of Watertown, N.Y., or the AB-type control valves manufactured by Wabtec Corporation of Wilmerding, Pa., typically supply air pressure to the brake cylinder of a freight car. If the brake cylinder or the plumbing between the control valve and the car has a leak, however, the brake cylinder will not maintain the original set pressure. In addition to brake cylinder leakage, resulting in low brake cylinder pressure, the brake system can leak into the brake cylinder, resulting in high brake cylinder pressure.
[0005] Brake control systems on rail or freight cars that comply with AAR standards are referred to as displacement type system and the brake cylinder pressure is proportional to the size of the auxiliary reservoir and brake cylinder volumes, which are proscribed by AAR regulations and controlled by means of the brake control valve. Control of the brake cylinder pressure is in response to modulation of the brake pipe pressure by the train driver. Although these systems are very reliable, they operate in an open loop mode with the brake cylinder pressure being the result of the relationship between auxiliary reservoir and brake pipe pressures. As a result, there is no feedback of brake cylinder pressure for the purpose of closed loop control. Leakage into or out of the brake cylinder may therefore result in brake cylinder pressures that are higher or lower than desired without any recognition by the system that the pressures are abnormal. While recently improvement to AAR brake systems include the addition of brake cylinder maintaining valves that compensate for brake cylinder leakage, the issue of brake cylinder over-pressurization is still a problem and may occur as the result of leakage in the quick service limiting valve, in the auxiliary reservoir, in the emergency reservoir, in the auxiliary reservoir, or in the brake pipe pressure into the brake cylinder while the brakes are applied.
[0006] A brake failure that results in over-pressurization of the brakes on a car in train is very hazardous and may result in “hot wheels,” which damages the wheels and raises the potential for a subsequent wheel failure and even train derailment. The train driver is usually unaware that a car has over-pressurized brakes due, in part, to the length of the train and the number of cars in the train. The only existing method of addressing this problem is to install a network of hot wheel detectors along a predetermined location in the continental rail system that can detect a hot wheel on a car using a thermal sensor, identify the car ID using an RFID tag, and then send an alarm to a dispatch center so that a dispatcher can contact the train driver. Such systems are costly, require significant modifications to the existing infrastructure, and are limited in geographic scope. As a result, rail car mounted system that can prevent over-pressurization of the brake cylinder and avoid the resulting hot wheel problem would be a significant safety improvement.
BRIEF SUMMARY OF THE INVENTION
[0007] The present invention comprises a brake cylinder limiting valve having a first portion that determined actual brake cylinder pressure and a second portion that determined intended brake cylinder pressure, and then allows for venting of the brake cylinder pressure if the actual brake cylinder pressure exceeds intended brake pipe pressure by a predetermined threshold. The intended brake pipe pressure is determined based on a reduction in brake pipe pressure relative to emergency reservoir pressure and the preferred threshold for venting is a brake cylinder pressure that is more than two and one-half times the brake pipe pressure reduction, plus a nominal amount for tolerance.
[0008] In one embodiment, the first portion comprises a first chamber in communication with a source of brake cylinder pressure, a second chamber in communication with atmospheric pressure, and a first diaphragm separating the first and second chambers and having a first wetted area, with the diaphragm configured to open a brake cylinder pressure exhaust port against the bias of a spring. The second portion comprises a third chamber in communication with a source of brake pressure, a fourth chamber in communication with a source of emergency reservoir pressure, and a second diaphragm separating the third and fourth chambers and having a second wetted area that is greater than the first wetted area by a threshold ratio, where the diaphragm is moveable to impart a second force via a floating pin that also biases the seat into the closed position. Thus, the brake cylinder pressure in the first chamber will be exhausted when it overcomes the bias force of the spring and any bias force being applied by the second diaphragm. The wetted area ratio of the second diaphragm to the first diaphragm is preferably 2.5 to 1, thereby providing for the same ratio of brake pipe pressure reduction to brake cylinder pressure increase required in an AAR compliant braking system. The brake cylinder limiting valve may be interconnected to the existing 4-port testing interface of a pipe bracket, or integrated into any number of locations in a conventional brake control valve.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING(S)
[0009] The present invention will be more fully understood and appreciated by reading the following Detailed Description in conjunction with the accompanying drawings, in which:
[0010] FIG. 1 is a schematic of a brake cylinder limiting valve according to the present invention;
[0011] FIG. 2 is a perspective view of an AAR control valve retrofitted in a first configuration with a brake cylinder limiting valve according to the present invention;
[0012] FIG. 3 is a perspective view of an AAR control valve retrofitted in a second configuration with a brake cylinder limiting valve according to the present invention;
[0013] FIG. 4 is a perspective view of a brake cylinder limiting valve adaptor according to the present invention for interconnecting to an AAR control valve; and
[0014] FIG. 5 is a schematic of a brake control valve showing three alternative locations for the installation of a brake cylinder limiting valve according to the present invention.
DETAILED DESCRIPTION OF THE INVENTION
[0015] Referring now to the drawings, wherein like reference numerals refer to like parts throughout, there is seen in FIG. 1 a brake cylinder limiting valve 10 for preventing over-pressurization of a brake cylinder. Valve 10 is a 2.5:1 differential pressure limiting valve which has a first portion that pneumatically determines the intended brake cylinder pressure and a second portion that compares the intended brake cylinder pressure to the actual brake cylinder pressure. The 2.5:1 differential pressure is selected to account for the ratio of brake pipe pressure to brake cylinder pressure required to be in an AAR compliance system. More specifically, because of the volumetric relationship between the auxiliary reservoir and the brake cylinder in an AAR braking system, a reduction in the brake pipe pressure will cause an increase in brake cylinder pressure which is 2.5 times the brake pipe reduction. For example, when an operator makes a 10 psi brake pipe reduction to actuate the brakes, the brake cylinder pressure is increased by 25 psi. Thus, it should be recognized that the present invention could be configured for a different differential pressure as desired or required by a non-AAR compliant system or system having different requirements.
[0016] As seen in FIG. 1 , valve 10 comprises a first port 12 in fluid communication with a source of brake cylinder pressure BC, a second port 14 in fluid communication with an exhaust EX (atmospheric pressure), a third port 16 in fluid communication with a source of brake pipe pressure BP, and a fourth port 18 in communication with a source of emergency reservoir pressure ER. Valve 10 further comprises a first diaphragm 20 separating a first chamber 22 that is in communication with first port 12 from a second chamber 24 that is in communication with second port 14 and exhaust EX. A spring 26 biases diaphragm 20 to move a seat 28 positioned thereon to selectively opens and close communication between first port 12 and an exhaust port 30 . Spring 26 is configured to provide the equivalent biasing force of between 5 and 10 psi.
[0017] A second diaphragm 32 is positioned in valve 10 to separate a third chamber 34 in communication with third port 16 and brake pipe pressure BP from a fourth chamber 36 in communication with fourth port 18 and emergency reservoir pressure ER. Movement of second diaphragm 32 is communicated to first diaphragm 20 via a floating pin 38 , thereby allowing a decrease in brake pipe pressure BP to adjust the amount of force necessary to open seat 28 . The wetted area of second diaphragm 32 separating the emergency reservoir pressure ER chamber 36 and brake pipe pressure BP chamber 34 is selected to be about 2.5 times the wetted area of first diaphragm 22 . As a result, valve 10 will not open seat 28 and vent brake cylinder pressure BC to exhaust port 30 unless brake cylinder pressure BC in chamber 22 exceeds both the bias force of spring 26 and 2.5 times any force applied to diaphragm 20 by pin 38 and diaphragm 32 , which is the amount of reduction of brake pipe pressure BP in chamber 34 . Thus, the first portion of valve 10 comprises an actual brake cylinder pressure feedback that is compared against the intended brake pipe pressure as determined by brake pipe pressure. As a result, valve 10 can determine whether the actual brake cylinder pressure exceeds the intended brake cylinder pressure and exhaust the brake cylinder if it is over pressurized by an amount equal to the bias force of spring 26 .
[0018] Exhaust port 30 is preferably connected to the inlet 40 of an exhaust valve 42 having a pilot 44 in communication with brake cylinder pressure BC that acts against a valve spring 46 to selectively connected exhaust port 30 with an exhaust EX. Valve spring 46 is configured to provide a biasing force equal to about 20 psi and thus will close exhaust valve 42 if brake cylinder pressure BC falls below about 20 psi. Conventional AAR brake systems include a retainer valve that, when manually activated, will bottle up the brake cylinder pressure by sealing the brake cylinder exhaust. This allows the train driver to bottle up the brakes on the cars, and then make a release and recharge of the brake pipe and all of the control valves on the train while the retainer bottles brake cylinder pressure. Retainers are typically used while descending long grades. By AAR standard, the retainer will bottle 20 psi in the high pressure setting. Exhaust cut-off valve 42 thus disables the brake cylinder limiting valve in retainer operations to comply with AAR standards.
[0019] In release and recharge, both the emergency and auxiliary reservoirs are pressurized to the brake pipe pressure, usually 90 psi. During a service brake application, the emergency reservoir pressure is unchanged from the original charge state. The brake cylinder limiting valve thus uses the difference between the emergency reservoir pressure and the brake pipe pressure to determine the brake pipe reduction, which is the brake command signal. The brake reduction is thus compared to the actual brake cylinder feedback pressure.
[0020] As explained above, during a normal brake application the brake cylinder pressure BC will be about 2.5 times the brake pipe reduction. Brake cylinder limiting valve 10 will therefore be in force balance and exhaust port 30 will be held closed by valve spring 26 , which has a nominal preload of between about 5 and 10 psi. This preload prevents undesired leakage from the brake cylinder limiting valve 10 in the balanced state, and accommodates tolerance variations of the brake system. If brake cylinder pressure BC increases as a result of any undesired leakage into the brake cylinder, such as from the brake pipe, the auxiliary reservoir, or the emergency reservoir, and does so in an amount equal to or greater than the value of spring 26 , first diaphragm 20 will move downwardly, as seen in FIG. 1 , thereby opening seat 28 and allowing brake cylinder pressure in chamber 22 to escape out of exhaust port 30 .
[0021] In an emergency brake application, brake pipe pressure is vented to zero psi and the emergency and auxiliary reservoirs and brake cylinder pressures are at equilibrium. Due to the ratios of the wetted areas in brake cylinder limiting valve 10 , exhaust port 30 is held firmly closed by seat 28 .
[0022] While FIG. 1 shows a brake cylinder limiting valve 10 having flexible diaphragms 20 and 32 , as well as floating pin 38 to provide force communication, the function of brake cylinder limiting valve 10 could be implemented using other comparable valve structures, such as a combination of pistons and seals that provide the requisite 2.5 to 1 area ratio between the actual brake cylinder feedback portion and the intended brake cylinder pressure determining portion.
[0023] As seen in FIG. 2 , valve 10 may be provided in a module 50 adapted for interconnection to a single-sided pipe bracket 52 via the existing 4-port interface 54 that is provided for periodic connection to a single car testing device. 4-port interface 54 includes conduits that provide for fluid communication to brake pipe pressure BP, auxiliary reservoir pressure AR, emergency reservoir pressure ER, and brake cylinder pressure BC and can thus provide all needed inputs for valve 10 . In FIG. 2 , module 50 is connected directly to 4-port interface 54 of pipe bracket 52 . As a result, module 53 would have to be removed so that a single car testing device could be connected to 4-port interface 54 for periodic testing of the braking system.
[0024] As seen in FIGS. 3 and 4 , valve 10 may be incorporated into an module 60 that is attached directly along a first side 66 to 4-port interface 54 and that contains a series of conduits 62 formed therein to provide fluid communication to valve 10 as well as to a corresponding set of ports 64 on a second side 68 that allow a conventional testing device to be attached to module 60 for periodic testing purposes. Although module 60 is shown in FIG. 3 to be attached to 4-port interface 54 with valve 10 above pipe bracket, module 60 could be configured to position valve 10 below pipe bracket 52 . As further seen in FIG. 3 , a test adaptor 70 may be bolted over adaptor 60 to allow for connection to a single car testing device.
[0025] It should be recognized by those of skill in the art that valve 10 may be configured into any portion of a braking system control valve, such as by redesigning the packaging of the control valve, as a module that interfaces to the release valve interface, or as a module fitted between either the service portion and the pipe bracket or the emergency portion and the pipe bracket (or by including valve 10 in any other location that has pneumatic access to brake pipe, emergency reservoir, and brake cylinder pressures). As seen in FIG. 5 , valve 10 may be integrated into one of at least three different locations, Alt 1 , Alt 2 , and Alt 3 , respectively, of a control valve 72 .
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A brake cylinder limiting valve having a first portion that determines actual brake cylinder pressure and a second portion that determines intended brake cylinder pressure based on brake pipe pressure reduction. The two portions are combined so that brake cylinder pressure will be vented if the actual brake cylinder pressure exceeds intended brake cylinder pressure by a predetermined threshold amount, which is preferably two and one-half times the brake pipe pressure reduction. An exhaust cut-off valve may be used to prevent venting of the brake cylinder pressure if it falls below a predetermined value.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to methods and apparatus for bleaching clothes and, more particularly, relates to techniques for "stone-washing" clothes using pumice rock impregnated with potassium permanganate.
2. Description of the Background
Stone-washing of garments has become increasingly popular in the past decade. This process generally consists of exposing the garments, such as jeans, to a combination of bleaching and an abrasive material, so that the jeans become both faded and appear to have been worn. The worn appearance desired by stone-washing may be obtained by (1) tumbling the garments with an abrasive stone, metal, or plastic material in a "dry" process, (2) tumbling the garments in a washing machine wherein the internal walls of a washing machine cylinder have been previously abraded by a volcanic rock, (3) washing the garments in water containing pumice rock, as generally described in German specification No. DE129699, or (4) agitating the garments in water and pumice sand, as disclosed in U.S. Pat. No. 4,575,887.
With respect to the first technique described above, the desired stone-washed appearance can be obtained by impregnating the pumice rock with potassium permanganate or other bleaching solutions. Pumice rock is an ideal abrasive material for achieving the desired worn appearance for the garments, and impregnated pumice rock allows the bleaching and abrasive functions to co-act with very favorable results. One of the significant problems with the pumice rock tumbling technique, however, relates to the difficulty of getting the bleaching solution to completely impregnate the pumice rock. Pumice rock is generally lighter than the potassium permanganate solution, and thus floats on the solution. Pumice rock has heretofore been placed in perforated buckets and forced down into a potassium permanganate solution, so that the solution impregnates the outer layer of pumice rock. The rock with the impregnated outer layer is then tumbled with the garments as described above in the stone-washing process. After the batch of garments has been tumbled, the garments are typically separated from the reduced diameter rock, which typically has its outer layer worn off by the abrasive tumbling action. A new outer layer of the rock is then generally reimpregnated and the rock reused in another batch process, until the rock or stones are reduced to an impractically small size, at which time the stones are discarded.
The impregnation of wood with preservatives or fire retardant liquids has long been accomplished by immersing the wood in liquid, then applying pressure to the liquid to drive the liquid into the wood, as disclosed in U.S Pat. Nos. 3,671,299 and 3,460,979. U.S. Pat. No. 4,433,031 discloses a special polymer for impregnating wood, wherein the wood is placed in a sealed chamber, a vacuum of at least twenty-six inches of mercury is drawn on the container, the wood is immersed in liquid while still under a reduced pressure, and pressure is increased to a level of about 350 psi to drive the liquid into the wood. Others have suggested the use of wave energy (U.S. Pat. No. 3,551,190) and sonic vibration (U.S. Pat. No. 3,639,152) to assist in impregnation of wood with a liquid preservative.
Metal castings intended to be subjected to pressure have long been impregnated with resins to seal porosity and prevent leakage. In many instances, the impregnation of metal castings seeks to seal the exposed surfaces of the castings rather than to impregnate the entire casting. The casting may be immersed in liquid and a vacuum then drawn on the chamber holding the castings (wet vacuum), or the vacuum may be first drawn on the chamber in which the castings are placed and liquid added (dry vacuum). In either case, the vacuum is released to achieve the effect of driving the resin into the outer skin layer of the casting. According to the disclosures of U.S. Pat. Nos. 4,311,735 and 4,384,014, pressure is subsequently applied to the chamber to assist in driving the liquid into the castings. A centrifuge for recovering excess impregnating liquid is disclosed in U.S. Pat. No. 4,196,231, and a special pressure vessel with porous support members is disclosed in U.S. Pat. No. 4,620,991.
An application roller for pressing an impregnating material into stone plates to seal the plates is disclosed in U.S. Pat. No. 4,620,989. U.S. Pat. No. 4,013,809 discloses a technique for sealing porous block, wherein the block is placed in a liquid-tight flexible bag which is then subjected to a vacuum, and a resin fed into the bag to immerse the block. A continous process for removing air from fruits and vegetables is disclosed in U.S. Pat. No. 3,052,209.
Although several porous objects, principally wood and metal castings, have long been impregnated with liquids with the assistance of vacuum, those skilled in the art of bleaching clothes and stone-washing fabrics have heretofore not recognized the applicability of technology associated with impregnating porous objects for stone-washing and, particularly, for impregnating pumice rock with a bleaching solution. Moreover, the characteristics of pumice rock and the purpose served by using pumice rock impregnated with a bleaching liquid as an integral step of a fabric bleaching process have historically been considered distinct from the characteristics of wood or castings and the techniques associated with impregnating those objects to retard decay and/or seal the object's surface.
The disadvantages of the prior art are, however, overcome by the present invention, and improved methods and apparatus are hereinafter disclosed for giving garments a worn and bleached or "stone-washed" appearance utilizing pumice rock impregnated to its core with a selected bleaching solution, such as potassium permanganate.
SUMMARY OF THE INVENTION
According to the preferred technique of the present invention, pumice rock is placed in a vessel and washed with water to remove fines and clay minerals. The vessel is then sealed and a vacuum drawn to approximately twenty inches of mercury. With the vacuum pump off, potassium premanganate is sprayed into the vessel. As potassium premanganate is sprayed into the evacuated vessel, the pressure will fall due to the input of liquid to the vessel and the release of air from the pumice rock. The spraying operation is continued until the vacuum drops a preselected level, typically from zero to three inches of mercury, at which time the spraying is discontinued. The pumice rock, if fully impregnated with potassium permanganate, will typically sink in the liquid bath. If the pumice is not fully impregnated, the process is repeated. Once the pumice is fully impregnated, the liquid is then drained from the vessel for reuse, and the impregnated rock tumbled with the garments in a perforated drum. The garments are then removed from the drum and placed in a sodium bisulfite solution to neutralize the potassium permangante, are subsequently washed in water, and finally dried. During tumbling, small fragments of grains from the pumice rock pass through the perforations of the drum and are discarded. After several tumbling operations, additional potassium permanganate is added to the tumbler.
It is an object of the present invention to provide an improved technique for stone-washing garments using pumice rock or a similar porous abrasive material which is entirely impregnated with a bleaching liquid.
It is another object of the invention to provide a low-cost rapid technique for impregnating pumice rock with a bleaching liquid until the entirety of the rock is permeated.
It is another feature of the invention to provide an improved technique for impregnating pumice rock with potassium permanganate which minimizes the handling of concentrated potassium permanganate by operators.
A feature of the present invention utilizes a sprayed liquid in a vacuum chamber to impregnate pumice rock.
It is an advantage of the present invention that the pumic rock may be reused for tumbling with garments for repeated stone-washing operations without the rock having to be reimpregnated with a bleaching solution.
The techniques of the present invention are well adapted for achieving quality stone-washing of garments without requiring a great deal of labor and without utilizing expensive equipment. The techniques of the present invention are well adapted to large-scale commercial stone-washing operations.
These and further objects, features, and advantages of the present invention will become apparent from the following detailed description, wherein reference is made to the Figures in the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a pictorial view, partially in cross-section, of a suitable vessel for impregnating pumice rock according to the present invention.
FIG. 2 is a flow block diagram of the method according to the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
The technique of the present invention allows garments to be more economically stone-washed. The invention is particularly applicable to the commercial treatment of new garments in a batch process. Typically one-thousand garments or more may be delivered by a garment manufacturer to a facility for stone-washing, and the garments batch-treated according the the present invention in lot sizes depending upon the size of the tumbler. The stone-washed garments are typically returned to the manufacturer for wholesale shipment to retailers. "Blue jeans" are one of the more popular stone-washed garments, although the invention is applicable to other garments and wearing apparel, including jackets, shirts, dresses, cloth shoes, etc.
Referring first to FIG. 1, there is shown a suitable vessel 10 for impregnating pumice rock with potassium permanganate or other selected liquid bleach. The vessel preferably includes a generally cylindrical upper body 12, a frustoconical lower body 14 having a discharge door 16 at a lower end thereof, a convex cover 18, and a top access door 20. With the doors, 16, 20 closed, a sealed cavity 22 is thereby formed within the vessel. A suitable transport cart (not shown) is intended to be positioned below the door 16 to receive impregnated pumic rock, and accordingly the vessel 10 is suitably supported on a plurality of conventional legs 24.
A drain line 28 with a filter cartridge 30 at the end thereof is provided for draining liquid from the vessel. Liquid is input to the vessel by a spray line 32 having a ring-shaped spray header 34 at the end thereof. Header 34 is preferably provided in the upper portion of the chamber 22, and includes a plurality of small diameter perforations 36 uniformly arranged about the circumference of the header, with some of the perforations being directed downward, some perforations being directed horizontally, and some perforations being directed at a downwardly inclined angle. A vacuum line 38 from the vessel is provided for withdrawing gas from the chamber 22 to create a vacuum within the vessel. A conventional sight glass 40 is provided for operator viewing of the liquid level in the vessel. If desired, a glass 41 may be provided in the convex cover 18 for operator viewing of the chamber 22 while under vacuum.
The top hinge door 20 may be power opened or closed by a plurality of fluid cylinders 42. The door 20 may be opened to input pumice rock into the vessel, and when closed, seals the vessel to create a fluid-tight chamber. Similarly, the discharge door 16 is pivotally provided for dumping impregnated pumice rock from the vessel to a transport buggy (not shown). The door 16 is powered by a plurality of cylinders 44, and seals with the vessel when closed. The angle of the frustoconical walls for the lower section 14 is preferably 45° or more from the horizontal, so that all pumice rock will slide out of the vessel when door 16 is fully open.
According to a preferred technique of the present invention and referring to FIGS. 1 and 2, pumice rock generally having a mean diameter in the range of from two to four inches is dumped through the opened door 20 into the vessel 10 to fill the lower conical section 14 and a portion of the cylindrical section 12. Water is then pumped into the vessel through line 46 and the pumice rock is washed to remove loose grit, clay, and sediment which might otherwise adversely effect the desired bleaching or abrasive action during the subsequent tumbling operation. The water may be discharged through line 28 and passed to a suitable drain.
Once the water from the discharge 28 is clear, a vacuum pump 52 is turned on to evacuate the chamber 22 to a selected level, generally in the range of from 18 to 22 inches of mercury. Potassium permanganate solution from storage tank 54 is then sprayed into vessel 10 by pump 56 through line 32. One-hundred gallons of solution may typically be input to the vessel holding approximately 300 to 600 pounds of pumice rock.
According to the present invention, all the pumice rock is preferably fully impregnated by the effect of spraying into an evacuated chamber which houses the rock, so that none of the rock need be thereafter reimpregnated after one or more tumbling operations. Accordingly, liquid potassium permanganate is sprayed into the evacuated upper portion of the chamber 22 with the vacuum pump off. Approximately one-hundred gallons of liquid potassium permanganate may be sprayed into the vessel during a time period of approximately ten minutes. Some of the sprayed liquid will vaporize due to the low pressure in the sealed vessel, air near the core of the pumice rock will be released and replaced with potassium permanganate, and accordingly air will be released from the pumice rock, and the released air and input of liquid to the sealed chamber will cause the vacuum to slowly drop. As the pumice rock becomes fully impregnated, it will sink in the excess (nonpermeating) liquid potassium permanganate bath.
After a desired quantity of sprayed liquid has been added and the vacuum in the sealed chamber reaches a predetermined level, e.g., 5 inches of mercury, the pump 56 may be shut off and the vessel left alone until the vacuum drops to a lower selected level, generally in the range of from 1 to 3 inches of mercury. During the waiting period, additional potassium permanganate may enter the rock above the liquid surface, and the impregnated rock will then sink. If the rock does not sink in a short period of time, the excess liquid may be retained in the tank, the vacuum again created, and the spray process again initiated until all the rock is fully impregnated and sinks in the liquid. Tests show that the center of the pumice rock becomes fully impregnated with potassium permanganate using the technique of the present invention.
In many instances, most of all of the rock will become full impregnated and thus sink in the liquid bath after one spraying operation. The techniques of the present invention are particularly suited to the rapid impregnation of pumice rock desired for commercial stone-washing operation. Accordingly, the tank may be immediately opened to atmosphere after the first spraying operation. If all the rock has not been fully impregnated (as observed by being 1-5 mersed in the liquid bath), the door 20 may be closed, a vacuum of approximately 20 inches of mercury drawn in the chamber 22, and the spraying process reinitiated. In almost all cases the entirety of the pumice rock can be easily and quickly fully impregnated by two such vacuum/spraying operations.
Once the rock has been fully impregnated, vent line 38 may be opened to allow air to enter the vessel and bring the pressure back to the atmospheric level. Drain line 28 may then be opened to drain liquid from the tank, and pump 58 may be activated to pump the drained liquid back to the storage tank 54 for subsequent reuse or, if desired, to a waste storage tank. The cylinder 44 may then be activated to open discharge door 16 and drop the impregnated rock to a transport cart. A quantity of new blue jeans, typically approximately 100 pair, may be placed in a conventional tumbler 60 having a perforated drum with approximately two-hundred pounds of impregnated pumice rock. The jeans and rock may then be tumbled for a short time period of from four to eight minutes, and the jeans removed from the tumbler and immediately placed in a neutralizing tank 62 containing, for instance, a liquid sodium bisulfite solution. Sodium bisulfite neutralizes the bleaching effect from the potassium permanganate, thereby inhibiting undesired additional deterioration of the fabric.
After being neutralized, the jeans may be placed in a conventional washer 64 and washed with water and a detergent to remove any remaining grit and chemicals. After being sufficiently washed, the jeans may be sent to dryer 66 for conventional drying, then folded and packaged for shipment back to the manufacturer.
During the tumbling operation, the pumice rock will abrade against the jeans, thereby giving the jeans the desired "worn" look, while the potassium permanganate within the pumice rock is slowly released during this abrasive process to perform its desired bleaching effect on the jeans. This tumbling action will cause the exterior layer of each pumice rock to become worn away so that the rock will decrease in size. Nevertheless, since the rock has been fully impregnated with potassium permanganate, the new layer continues to contain the desired quantity of liquid bleach to achieve its intended effect. During the tumbling operation, most of the grit or sand worn off the pumice rock will pass through perforations in the tumbler, and may be discharged from the bottom of the tumbler and discarded.
A given quantity of pumice rock may typically be used for tumbling several "loads" of jeans. After a period of time, additional pumice rock may be added to the tumbler with a new batch of jeans. As a feature of the present invention, however, the "used" pumice rock need not be reimpregnated, and may be continually reused until its size is sufficient to allow it to pass through the perforations in the tumbler. If desired, the used pumice rock may be dumped from the tumbler 60 and weighed so that a known weight of pumice rock may be provided for a new batch of jeans.
A suitable drain pump 58 is a Dayton Model 1P835 11/2 HP centrifugal pump with a 11/4" inlet and a 1" outlet. A suitable spray pump 56 is a Dayton Model 1P833 3/4 HP centrifugal pump with a 1" inlet and a 3/4 outlet. A suitable vacuum pump 52 is a Dayton Model 4ZH70 11/2 HP vacuum pump.
Several modifications of the technique described above will be suggested by the above disclosure. The rock may be put in the tumbler, a vacuum drawn on the tumbler, and the liquid input such that the liquid cascades slowly over the pumice rock. Also, it may be possible in input a relatively small quanitity of pumice rock to a liquid bath with a vacuum above the bath, allowing the layer of floating pumice rock to become impregnated and thus sink, and then input another quantity of rock. This latter procedure would, however, be time consuming and thus expensive compared to the preferred spraying technique. Alternatively, (although again less desirably) the rock could be repeatedly raised and lowered above and below the level of a liquid potassium permanganate bath, or the liquid level could be repeatedly raised or lowered with respect to the rock, such that each rock is repeatedly subjected to the liquid/air (vacuum) interface.
According to the present invention, liquid is input to a chamber which houses the pumice rock and is under a vacuum. The liquid is input in such a manner that each rock is continually and/or repeatedly subjected to both the simultaneous vacuum and to the liquid. In this manner, the liquid potassium permanganate penetrates the rock in a much more rapid manner and to a much deeper extent than if the rock were fully submerged in a liquid bath. The rock, once fully impregnated, will tend to sink in the liquid bath, and this provides an easy technique for determining if the rock is fully impregnated, or if the vaccum/spray process should be repeated.
Although the invention has been described in terms of specified embodiments which are set forth in detail, it should be understood that this is by illustration only and that the invention is not necessarily limited thereto, since alternative embodiments and operating techniques will become apparent to those skilled in the art in view of the disclosure. Accordingly, modifications are contemplated which can be made without departing from the spirit of the described invention.
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Improved techniques are provided for giving new garments, such as jeans, a worn appearance by tumbling the garments with potassium permanganate impregnated pumice rock. Pumice rock is thoroughly and quickly impregnated with potassium permanganate solution by placing the rock in a sealed chamber, drawing a vacuum in the chamber, spraying a potassium permanganate solution into the chamber while allowing the vacuum to drop to a preselected level, then retrieving the impregnated rock from the chamber. The garments and impregnated rock are then tumbled in a perforated container. New garments are added with additional rock to replenish the reduced the reduced volume of the used rock, which need not be reimpregnated. A preferred stone-washed appearance may be obtained by the combined bleaching effect of the potassium permanganate and the abrasive action of the rock.
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[0001] This application claims the benefit of U.S. application Ser. No. 09/282306, filed Mar. 31, 1999, which claims the benefit of U.S. Provisional Application No. 60/118952, filed Feb. 5, 1999, each of which is incorporated herein by reference in its entirety.
FIELD OF THE INVENTION
[0002] The field of the invention is weight bearing systems such as studs, joists, beams, and related devices and methods.
BACKGROUND OF THE INVENTION
[0003] Weight bearing systems comprise primary weight bearing elements such as studs and joists, and secondary weight bearing elements such as rim bands and end caps. Such weight bearing elements are common components in many constructions. For example, floor and ceiling joists function as weight bearing elements and are frequently found in residential and commercial buildings. Although there is a large variety of weight bearing elements, many weight bearing elements are limited in length and weight bearing capacity due to the material(s) from which they are constructed, and are oftentimes difficult to incorporate into constructions because of their structure or cost.
[0004] Primary Weight Bearing Elements
[0005] Primary weight bearing elements can be grouped in two classes, elements predominantly made from wood, and elements predominantly made from metal. Generally, primary weight bearing elements made from wood are found in older constructions, and were traditionally made from solid saw lumber. However, due in part to a sharp decline in the supply of appropriate solid saw lumber, alternative primary weight bearing members which use less solid saw lumber were developed. Such alternatives generally comprise two chords (a top, compression chord/member and a bottom, tension chord/member extending the length of the primary weight bearing element) coupled together by a web (see U.S. Pat. No. 5,664,393 issued on Sep. 9, 1997 to Veilleux et al., U.S. Pat. No. 5,560,177 issued on Oct. 1, 1996 to Brightwell, and U.S. Pat. No. 4,228,631 issued on Oct. 21, 1980 to Geffe). A commonly found alternative is an I-joist having sawn lumber chords or plywood chords. Such an alternative element advantageously reduces the amount of wood required for construction and thereby reduces the weight of the primary weight bearing element. However, almost all forms of wooden primary weight bearing elements are relatively heavy when compared to equivalent metal structures.
[0006] Moreover, wooden primary weight bearing elements are oftentimes limited to lengths of about less than 24′.
[0007] Generally, primary weight bearing elements made from metal are lighter than comparable wooden elements, may span longer distances and are fireproof. Furthermore, such elements are often available in continuous lengths. Primary weight bearing elements made from metal are common in various forms, including light gauge steel C-profile joists, trichord open web joists and screw fabricated steel truss joists (see U.S. Pat. No. 5,687,538 issued on Nov. 18, 1997 to Frobosilo et al., U.S. Pat. No. 5,499,480 issued on Mar. 19, 1996 to Bass, U.S. Pat. No. 5,457,927 issued on Oct. 17, 1995 to Pellock et al., U.S. Pat. No. 5,157,883 issued on Oct. 27, 1992 to Meyer, U.S. Pat. No. 4,793,113 issued on Dec. 27, 1988 to Bodnar, U.S. Pat. No. 4,729,201 issued on Mar. 8, 1988 to Laurus et al., U.S. Pat. No. 4,159,604 issued on Jul. 3, 1979 to Burrell, U.S. Pat. No. 3,686,819 issued on Aug. 29, 1972 to Atkinson, U.S. Pat. No. 3,541,749 issued on Nov. 24, 1970 to Troutner, U.S. Pat. No. 3,221,467 issued on Dec. 7, 1965 to Henkels, U.S. Pat. No. 2,578,465 issued on Dec. 11, 1951 to Davis, Jr. et al., U.S. Pat. No. 2,387,432 issued on Oct. 23, 1945 to Laney, and U.S. Pat. No. 157,994 issued on Apr. 4, 1950 to Palmer).
[0008] Light gauge steel C-profile joists may be manufactured from roll-formed galvanized steel. However, in order to achieve appropriate rigidity, light gauge steel C-profile joists are oftentimes made from 16-gauge steel, which tends to be more difficult to drill or perforate. Furthermore, additional elements are oftentimes difficult to attach to light gauge steel C-profile joists.
[0009] Trichord open web joists are generally more rigid than light gauge steel with C-profile but often have to be custom manufactured to fit span, load, etc. A further common disadvantage of trichord open web joists is that they are difficult to attach or to join with hangers.
[0010] Screw fabricated steel truss joists often suffer from 4 common drawbacks: They are labor-intensive, expensive in manufacturing, have to be custom made and tend to loosening of screws leading to impaired stability and additional wear.
[0011] Secondary Weight Bearing Elements
[0012] Rim bands are used to couple a structural element such as a joist to an adjacent structural elements such as wall studs. A simple rim band might have a “C” shape comprising one vertical segment and two horizontal segments, with the vertical or “back” segment tending to be substantially longer than the “top” and “bottom” horizontal segments or “legs”. One drawback of many rim bands is the tendency for the back to buckle. This tendency is generally compensated for by mounting the rim band to the side of one or more structural members such as a beam or studs such that compression forces are born primarily by the supporting structural member(s) rather than the rim band. An example of a rim band which is mounted in such a fashion can be found by referring to U.S. Pat. No. 5,956,916 issued on Sep. 28, 1999 to Liss. The rim band/ledger beam of Liss comprises a standard C shape with shear tabs punched out of and folded away from the back segment of the rim band. The rim band of Liss, although suitable in many applications, also suffers from the drawback that the shear tabs comprise a single piece folded out from the center of the back of the rim band. The centered shear tabs do not extend to the portions of the back adjacent to the top and bottom horizontal segments and thus would provide poor, if any, coupling to a joist comprising top and bottom cords as described above. Difficulty in attaching joists is a drawback of many rim bands. Moreover, if the sheer tabs did extend the entire length of the back, the rim band would have a tendency to bend under vertical loads at points where the shear tabs were located as only the horizontal legs of the rim band would be left to provide support at such points. Also, forming the bend causing the shear tabs to be positioned perpendicular to the back of the rim band may require more force than can easily be achieved at a work site. Yet another drawback found in some rim bands is the lack of a common rim band for use in structures having differently spaced joists.
[0013] Thus, there is still a need for improved weight bearing systems and methods to produce improved weight bearing elements.
SUMMARY OF THE INVENTION
[0014] The present invention is directed to improved weight bearing elements and methods relating to same. Some such elements are contemplated as having a web, and a chord connected to the web, the chord perimeter having a cross-sectional shape of a closed multi-sided figure having at least 5 sides, at least two of which are substantially parallel to the web. Some members may have chords which have a pentagonal cross sectional shape, and/or may include load transferring members or end-caps.
[0015] Other elements may comprise a stiffened rim band having pairs of die cut tabs and/or stiffening ribs positioned along the member/rim band. Some such elements comprise pairs of die cut tabs positioned along the length of the member at intervals which are a fraction of the distance used in standard joist spacings. Other elements comprise one or more pairs of die cut tabs positioned directly opposite each other such that one tab is adjacent the top of the rim band while the corresponding tab is adjacent the bottom of the rim band. Still other elements may comprise a diamond shape stiffener extruding from the back of the rim band and possibly formed by punching a slot into the back of the rim band and pushing the ends of the slot out from the back so as to form the diamond shape.
[0016] In some embodiments, the weight bearing elements disclosed herein may be “roll-formed” from a continuous sheet of material such as light gauge galvanized steel. In other embodiments, they may exhibit one or more of the following feature: improved load bearing capacity; lighter weight; reduced material usage; easier to manufacture and/or install; able to be cut to custom lengths.
[0017] Although joists are only a subset of the primary weight bearing elements to which the disclosed subject matter applies, the term “joist” will be used frequently hereafter to refer to all primary weight bearing elements in order to make this disclosure easier to read. Similarly, the term “rim bands” will be used frequently hereafter to refer to all secondary wait bearing elements. The term polygonal as used herein includes figures in which the bounding line segments are joined by curves as well as more traditional “angular” figures.
[0018] Various objects, features, aspects and advantages of the present invention will become more apparent from the following detailed description of preferred embodiments of the invention, along with the accompanying drawings in which like numerals represent like components.
BRIEF DESCRIPTION OF THE DRAWINGS
[0019] [0019]FIG. 1 is a perspective view of a joist embodying the invention.
[0020] [0020]FIG. 2 is a cross-sectional view of the joist of FIG. 1.
[0021] [0021]FIG. 3 is a perspective view of a joist and load transfer member combination embodying the invention.
[0022] [0022]FIG. 4 is a perspective view of a joist and end cap combination embodying the invention.
[0023] [0023]FIG. 5 is a perspective view of a back-mounted end cap.
[0024] [0024]FIG. 6 is a perspective view of a joist being connected to a “track” type support via a back mounted end-cap.
[0025] [0025]FIG. 7 is a perspective view of a back and bottom mounted endcap.
[0026] [0026]FIG. 8 is a perspective view of the endcap of FIG. 7 being used to connect a joist to a “rail” type support via a back and bottom mounted endcap.
[0027] [0027]FIG. 9 is a perspective view of a rim band embodying the invention.
[0028] [0028]FIG. 10 is a plan view of a cut sheet prior to its being folded into the rim band of FIG. 9.
[0029] [0029]FIG. 11 is a side view of the rim band of FIG. 9.
[0030] [0030]FIG. 12 is a top view of the rim band of FIG. 9.
[0031] [0031]FIG. 13 is a detail view of one of the diecut tabs of the rim band of FIG. 9.
[0032] [0032]FIG. 14 is a front view of one of the stiffeners of the rim band of FIG. 9.
[0033] [0033]FIG. 15 is a side view of one of the stiffeners of the rim band of FIG. 9.
[0034] [0034]FIG. 15 is a perspective view of a rim band and joist according to the claimed invention.
[0035] [0035]FIG. 16 is a perspective view of a rim band and joist according to the claimed invention.
[0036] [0036]FIG. 17 is a perspective view of a support system according to the claimed invention having showing how joists can be coupled to every other pair of diecut tabs to space the joists 16″ intervals.
[0037] [0037]FIG. 18 is a perspective view of a support system according to the claimed invention having showing how joists can be coupled to every third pair of diecut tabs to space the joists 24″ intervals.
[0038] [0038]FIG. 19 is a perspective view of a rim band embedded in a wall and providing support to upper studs.
[0039] [0039]FIG. 20 is a perspective view of a rim band embedded in a solid wall.
DETAILED DESCRIPTION
[0040] Joist
[0041] Referring to FIGS. 1 and 2, a preferred primary weight bearing element/joist 10 comprises top/tension and bottom/compression chords 100 and web 200 . Chords 100 comprise a top supporting side 110 , a left supporting side 120 A, a right supporting side 120 B, and left and right transition sides 130 A, and 130 B. Web 200 comprises body 210 , flanges 220 , fasteners 230 , and chord lips 240 . Referring to FIG. 2, the perimeters of chords 100 of joist 10 can be seen to have a polygonal cross sectional shape having 5 sides, at least two of which are substantially parallel to the web.
[0042] In preferred embodiments, supporting side 110 couples the two parallel sides 120 A and 120 B to each other and provides a load bearing surface. Sides 120 A and 120 B are substantially parallel to each other and to the body 210 of web 200 . Sides 110 , 120 A, 120 B, 130 A and 130 B can be seen to be planar and to compose parts, via their exterior surfaces 111 , 121 A, 121 B, 131 A, and 131 B, of the perimeter surface of the chord and to define a cavity 300 via their interior surfaces 112 , 122 A, 122 B, 132 A, and 132 B, which are not part of the perimeter surface of the chord. Thus, cavity 300 is adjacent to and partially forms a cavity located within the perimeter surface of the chord. Chords 100 are generally parallel to each other, and the cavities 300 contained within them extends the length of the chords 100 .
[0043] In joist/primary weight bearing element 10 , the 5 planar sides 111 , 121 A, 121 B, 131 A, and 131 B can referred in a number of ways. It is contemplated that referring to side 111 as the top mounting surface of chord 10 , side 121 A as the left mounting surface of chord 10 , side 121 B as the right mounting surface of chord 10 , side 131 A as the left transition surface of chord 10 , and side 131 B as the right transition surface of chord 10 may be beneficial. Using such terms to distinguish between the sides, it can be seen that joist 10 and its sides have the following features: the left side mounting surface 121 A and the night side mounting surface 121 B are each substantially parallel to body 210 of web 200 ; the top mounting surface 111 is substantially perpendicular to the web body 210 ; the left side mounting surface 121 A, the right side mounting surface 121 B, the left transition surface 131 A, and the right transition surface 131 B each comprise a top edge and a bottom edge with the top edge of each of the left side mounting surface 121 A and right side mounting surface 121 B being coupled to the top mounting surface 111 , the bottom edge of the left side mounting surface 121 A being coupled to the top edge 111 of the left transition surface 131 A, and the bottom edge of the right side mounting surface 121 B being coupled to the top edge of the right transition surface 131 B; the left and right transition surfaces 131 A and 131 B extend away from all of the top mounting surface 111 , the left mounting surface 121 A, and the right mounting surface 12 1 B; and the bottom edge of each of the left transition surface 131 A and right transition surface 131 B are coupled to the web 200 .
[0044] It is contemplated that alternative embodiments of primary weight bearing elements may have A planar sides where A is one of 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, or A is greater than 15.
[0045] Because chords 100 comprise planar, i.e. relatively flat and thin, sides connected together, it is possible to form chords 100 from a sheet of thin material such as galvanized steel by simply bending the material into the pentagon shape of the chords 100 . It is contemplated that alternative embodiments may utilize various gauges of steel including, but not necessarily limited to 18 gauge and 20 gauge. It is also contemplated that alternative embodiments of primary weight bearing elements may have sides which are less than N inches thick where N is one of 1, 0.75, 0.5, 0.25, 0.125, and 0.1.
[0046] The cavity 300 within one or more of chords 100 may be filled with a material 300 A so as to increase the weight or modify the weight distribution of the joist/primary weight bearing element 10 . Thus, some embodiments may be ballast (from top to bottom) weighted as in a floor joist, or a drag (from bottom to top) weighted as in a ceiling joist. The material or materials used may be uniform throughout the cavity or may comprise separate elements located within the cavity 300 . The materials used may also be used to modify other features of the joist other than weight including, but not limited to, buoyancy and rigidity.
[0047] Web 200 is preferred to be formed from the same sheet of material as chords 100 . It is also preferred that web 200 be “open” in the sense that portions of the web body 210 are removed, preferably by punching, to create the pattern shown in FIGS. 1 and 2, as well as to form flanges 220 . Web 200 is also preferred to comprise fasteners 230 for fastening chord lips 240 to body 210 .
[0048] End Cap
[0049] It is also contemplated that joists 10 may be used in combination with load transferring studs 400 as shown in FIG. 3, or couplers 500 as shown in FIGS. 4 - 8 . Load transfer studs may be comprised of flat plates and/or more 3-dimensional shapes such as that shown in load transfer stud 400 of FIG. 3. The size and dimensions of various embodiments of transfer studs 400 may vary, as may the method and materials used to form them, so long as they serve to transfer load forces from one chord to another so as to lessen the load on web 200 . Couplers 500 can be used to couple joist 10 to a second joist or to some other object. It is contemplated that in some embodiments, a particular device may function as both a load transfer stud 400 and a coupler 500 . As with transfer studs 400 , the size and dimensions of various embodiments of couplers 500 may vary, as may the method and materials used to form them, so long as they serve to couple a joist 10 to a second joist or another object. Transfer studs 400 and couplers 500 may also vary as to the manner in and/or location at which they are coupled to joist 10 . Some embodiments may thus attach at the ends using screws, while others may be coupled to a non-end portion of the joist, may be fastened by welding or some other means, and may be coupled to one or more sides of chords 100 or to a portion of web 200 . Various methods of using transfer studs 400 and couplers 500 are pictured in FIGS. 3 - 8 .
[0050] It should be noted that the use of parallel sides 120 A and 120 B on chords 100 provide a flat surface to which sides 430 of transfer studs 400 and sides 530 couplers 500 can be attached. It is contemplated that some embodiments will include pre-drilled holes in chords 100 and in the back 410 and sides 430 transfer studs 400 , and in the back 510 and sides 530 of couplers 500 to facilitate the fastening of such studs 400 and couplers 500 to joists 10 via chords 100 through the use of screws or other fasteners.
[0051] Referring to FIGS. 5 - 8 , alternative forms of couplers/end caps 500 are shown. It is contemplated that an end cap 500 such as that of FIG. 5 is particularly suitable for mounting via sides 530 to a joist 10 and via back 510 to another support such as a joist 10 or the track support 610 of FIG. 6. It is also contemplated that an end cap 500 such as that of FIG. 6, because it comprises flanges 520 , will be particularly suitable for mounting to a rail support 620 of FIG. 8.
[0052] Rim Bands
[0053] Referring to FIG. 9, a secondary weight bearing element/rim band 800 comprises a C shape comprising back/vertical segment 810 , upper leg/horizontal segment 820 , and lower leg/holizontal segment 822 . Rim band 800 also comprises stiffeners 840 , upper die cut shear tabs 831 and lower die cut shear tabs 832 .
[0054] Back 810 may vary in height but is preferred to be approximately 12″ high. Similarly, the width of upper leg 821 and lower leg 822 may vary, but upper leg 821 is preferred to have a width of 2″ while lower leg 822 is preferred to have a width of 2″. Thus, a preferred rim band can be formed by folding a sheet of metal approximately 16″ wide into a C shape having sides of 2″, 12″, and 2″. Less preferred embodiments may comprise a single side/back 810 without legs 821 and 822 . It is contemplated that alternative embodiments may utilize various gauges of steel including, but not necessarily limited to 18 gauge and 20 gauge. It is contemplated that any length, width, or height may fall within a range of plus or minus 6″ or smaller of the specified length, width or height unless such variation is expressly prohibited herein.
[0055] Die cut shear tabs 831 and 832 comprise pairs of tabs positioned opposite each other long the rim band with each pair of tabs being used to couple a joist to the rim band. A given pair of tabs will comprise one upper tab 831 positioned adjacent the upper leg 821 of rim band 832 so that it can readily be coupled to the upper chord of a support member 10 , and a lower tab 832 positioned adjacent the lower leg 822 of rim band 832 so that it can readily be coupled to the lower chord of a support member 10 . In preferred embodiments where back 810 is 8.5″ high, shear tabs 831 and 832 will be separated from each other by a distance of 8.5″, and each will be separated from the nearest leg by less than 0.5″ or less than 0.25″.
[0056] In alternative embodiments, sets of tabs having more than two sets of tabs per set may be utilized. It is contemplated that in such embodiments the tabs would be vertically aligned in a fashion similar to the pairs of tabs of FIGS. 9 - 20 for use on structural members having sufficient side surface area for coupling to all of, or at least a subset of the tabs. Thus embodiments comprising sets of vertically aligned tabs wherein the sets comprise 3, 4, 5, 6, or more tabs are contemplated wherein all or a subset of tabs may be suitable for use with a given joist type.
[0057] Die cut shear tabs 831 and 832 are preferred to be uniform in size throughout rim band 800 although they may very in size and shape in less preferred embodiments. Die cut shear tabs are preferred, referring to FIG. 13, to be formed by creating 0.16″ wide, U-shaped cut in back 810 of rim band 800 , with the “U” having a base width of 1.2″ of one side and a height of 1.9″ for the remaining two parallel sides. The size and shape of shear tabs 831 and 832 , either individually or in plural may vary in size and/or shape.
[0058] Each shear tab 831 or 832 is preferred to comprise a plurality of holes positioned long the length of the tab parallel to the sides of rim band 800 such that fasteners such as screws and or nails can pass project through the holes into and in a line parallel to the chords of joist 10 .
[0059] Referring to FIGS. 10 - 13 , shear tabs 831 and 832 are preferred to be spaced along the length of rim band 800 such that the separation between centers of adjacent shear tabs is such that it is a fraction of at least two standard joist spacings. As an example, joists are typically spaced at 16″ and 24″ intervals. By spacing shear tabs 831 and 832 at 8″ intervals, a single rim band can be used regardless of whether 16″ or 24″ spacing is chosen by placing joists and every other or every third pair of shear tabs. Cutting tabs at 9.6″ centers to accommodate placing joists at 19.2″ centers is also contemplated.
[0060] Stiffening members 840 are, referring to FIGS. 14 and 15, preferred to comprise a diamond shape having a cutout center. By punching, cutting, or otherwise creating an elongated aperture 841 in back 810 , the sides of the aperture thus formed can be pushed or otherwise forced away from the back 810 of rim band 800 so as to form a diamond shape comprising sides 841 a - c , perimeter outer perimeter 843 , and inner perimeter 844 . Although the actual dimensions of stiffening member 840 may vary, preferred embodiments will have a length between tips of the outer perimeter 843 of 8″, and approximately 3″ for inner perimeter 844 . Stiffening members 840 are also preferred to extrude from back 810 for a height of 0.4″ at their centers, and 0.15″-0.2″ near the upper and lower points of perimeters 843 and 844 . A preferred diamond shape consists essentially of four sides forming two Vs positioned adjacent to each other but with opposite orientations. Each V has an angle formed by its two sides which is greater than 5 or 10 degrees, but less than or equal to 45 degrees, and the angles between adjacent sides of the Vs where they are coupled together are preferably greater than or equal to 135 degrees but less than 170 or 180 degrees. Less preferred embodiments may have different angular relationships between sides and/or may utilize more or less than four sides.
[0061] Less preferred embodiments may utilize smaller stiffening members shaped similarly to those described above. Such embodiments may utilize two or more vertically aligned stiffening members rather than a single larger stiffening member, or may utilize smaller stiffening members arranged in some other pattern.
[0062] It is contemplated that weight bearing systems comprising rim band 800 will benefit from reduced shear. It is also contemplated that the tabs 831 and 832 help strengthen rim band 800 . It has been observed that a rim band with and effective 8″ track/back height is stiffer than one with a 10″ track.
[0063] Weight Bearing Elements in General
[0064] It is contemplated that weight bearing elements according to the subject matter disclosed herein may vary greatly in size. Thus smaller primary weight bearing elements may be used in, among others, prosthetic devices including but not limited to dental implants covering multiple teeth and long bone replacements, household utensils, cars, small planes, scaffolding, and furniture. Larger elements may be used in, among others, bridges, oil tankers, large planes, and lightweight ladders.
[0065] It is contemplated that various embodiments of the weight bearing elements disclosed herein may be formed from one or more materials. Such materials may include, but are not necessarily limited to: a metal such as stainless steel, aluminum, galvanized steel, and iron; polymers such as PVC, thermoplastic, inflexible polyethylene, and polycarbonate, polypropylene, and polyethylene (such polymers may be provided in granules, in an unpolymerized for, and/or in sheets of flexible polymers); fibrous man-made material including, but not limited to, glass-/carbon fibers hardened with resins; and elemental metals including magnesium.
[0066] Methods of Formation
[0067] It is contemplated that weight bearing elements according to the subject matter disclosed herein may be formed in a number of methods involving steps which include, but not limited to: pre-forming such as by rolling from a coil and/or plates of precut lengths; and preprocessing such as by coating, cutting, and/or punching.
[0068] One method of forming a primary weight bearing element/support member 10 according to the claimed subject matter might simply involve roll forming a sheet of metal into the shape shown in FIGS. 1 and 2 by bending each side of the sheet six times so as to form a pentagonal chord 100 and chord lip 240 , and then fastening, possibly through the use of adhesives, screws, welding, or a clench press, chord lip 240 to body 210 . Such a method could also include a step of punching out portions of body 210 so as to form a web pattern and flanges 220 as shown in the figures.
[0069] Another method involves the use of polymers which may be deformed from a sheet into a pentagonal shape and then fixed by heat and/or glue. Similarly, granules or unpolymerized material may be filled into a mold and symmetrical portions cast with such portion then being fixed together by heat, ultrasound, glue, etceteras. In yet another example, a fibrous man-made material is wrapped around templates to create a first, immature form, which will be modified into a second, mature form by applying resin or other polymer to harden the fiber mats. In yet one more example magnesium may be poured into a mold to obtain a first, immature form of the product which will then be fixed by heat to form a second, mature form.
[0070] One method of forming a secondary weight bearing element/support member 800 according to the claimed subject matter might simply involve (1) folding the sides of a sheet of metal to form a standard C shape comprising upper leg/horizontal segment 821 , lower leg/horizontal segment 822 , and back/vertical segment 810 ; (2) making the die cuts to form upper shear tabs 831 and lower shear tabs 832 ; and (3) forming stiffeners 840 , possibly by a combined punch and press operation. Shear tabs 831 and 832 can either be folded outward from back 810 during manufacture, or, more preferably, can be folded out as needed during weight bearing system assembly. The actual order of formation of the various components of element 800 may be varied. Although die cutting the tabs is preferred, any method which allows for formation of sets of vertically aligned tabs along the length of the rim band may be utilized.
[0071] Methods of Use
[0072] In addition to the methods explicitly and inherently disclosed above, weight bearing systems according to the claimed invention may be used in building a structure by, referring to FIG. 19: (1) providing a rim band 800 ; (2) positioning the rim band on top of one or more lower studs 912 ; (3) coupling one or more joists 10 to the rim band such that the combination of rim band 800 and lower studs 912 at least partially supports the one or more joists 10 ; (4) positioning one or more upper studs 911 on top of the rim band 800 such that the combination of rim band 800 and lower studs 912 at least partially supports the upper studs 911 . In some methods, the rim band 800 provided may comprise upper and lower horizontal segments 821 and 822 wherein the lower horizontal segment 822 rests on and is coupled to the lower studs 912 and the upper studs rest on and are coupled to the upper horizontal segment 911 . In other methods, the end of a joist 10 is positioned between the upper and lower segments 821 and 822 of the rim band 800 such that it is directly above a lower stud 912 and directly below an upper stud 911 . In such methods it is preferred that one side of each of the upper stud 911 , the lower stud 912 , and the joist 10 have a side positioned in or adjacent to a common vertical reference plane A, or, even more preferably that a second side of each of the upper stud 911 , the lower stud 912 , and the joist 10 also have a side positioned in or adjacent to a second common vertical reference B plane, the second vertical reference plane being parallel to the first vertical reference plane. In many instances, the end of joist 10 , the back of rim band 800 , and a third side of studs 911 and 912 will be positioned in or adjacent to a third vertical reference plane C where C is perpendicular to reference planes A and B.
[0073] It is contemplated that vertically aligning a lower stud 912 , and upper stud 911 , and a joist 10 permits rim band 800 to support upper stud 911 . In such an instance it is contemplated that joist 10 obtains support from lower leg 822 and possibly back 810 of rim band 800 while providing sufficient support to upper leg 812 to prevent it from bending or otherwise deforming under the load transferred to it via upper stud 911 . Although alternative embodiments may not match joists 10 to pairs of vertically aligned upper and lower studs 911 and 912 on a one for one basis, it is preferred that embodiments placing upper stud 911 on top of rim band 800 have at least one joist vertically aligned which each pair of vertically aligned studs. Track 913 may also be incorporated into the system so as to provide additional stability to upper and/or lower studs 911 and 912 and to facilitate coupling the studs to the rim band 800 and/or another structural member such as floor 930 .
[0074] Referring to FIG. 20, another method of use of a rim band as described herein is to at least partially imbed it within a wall (or floor or other structural member), possibly by using as a form member during formation of a concrete wall. Although many types of rim bands may be suitable for such a use, the rim band described herein is particularly suitable as the die cut shear tabs can be folded out as necessary after the wall has been formed to provide ready attachment of joists without requiring insertion of fasteners into the wall. Although the need for stiffening members 840 is less apparent when back 810 is supported by an adjacent surface, stiffeners 840 may function to prevent lateral movement of rim band 800 after the wall is formed, and may prevent buckling of the rim band during wall formation.
[0075] In preferred methods, the rim band and/or joists will comprise one or more of the rim bands or joists as previously described and as claimed herein.
[0076] Thus, specific embodiments and applications of primary and secondary weight bearing elements and related methods have been disclosed. It should be apparent, however, to those skilled in the art that many more modifications besides those already described are possible without departing from the inventive concepts herein. The inventive subject matter, therefore, is not to be restricted except in the spirit of the appended claims. Moreover, in interpreting both the specification and the claims, all terms should be interpreted in the broadest possible manner consistent with the context. In particular, the terms “comprises” and “comprising” should be interpreted as referring to elements, components, or steps in a non-exclusive manner, indicating that the referenced elements, components, or steps may be present, or utilized, or combined with other elements, components, or steps that are not expressly referenced.
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The present invention is directed to improved weight bearing elements and methods relating to same. Some such elements are contemplated as having a web, and a chord connected to the web, the chord perimeter having a cross-sectional shape of a closed multi-sided figure having at least 5 sides, at least two of which are substantially parallel to the web. Some members may have chords which have a pentagonal cross sectional shape, and/or may include load transferring members or end-caps. Other elements may comprise a stiffened rim band having die cut tabs and stiffening ribs. Some such elements comprise pairs of die cut tabs positioned along the length of the member at intervals which are a fraction of the distance used in standard joist positioning. Other elements comprise one or more pairs of die cut tabs positioned directly opposite each other such that one tab is adjacent the top of the rim band while the corresponding tab is adjacent the bottom of the rim band. Still other elements may comprise a diamond shape stiffener extruding from the back of the rim band and possibly formed by punching a slot into the back of the rim band and pushing the ends of the slot out from the back so as to form the diamond shape. In some embodiments, the weight bearing elements disclosed herein may be “roll-formed” from a continuous sheet of material such as light gauge galvanized steel. In other embodiments, they may exhibit one or more of the following feature: improved load bearing capacity; lighter weight; reduced material usage; easier to manufacture and/or install; able to be cut to custom lengths.
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BACKGROUND OF INNENTION
[0001] 1. Field of the Invention
[0002] This invention relates to an organic-inorganic hybrid surface adhesion promoter and two-step processes for their preparation.
[0003] This organic-inorganic hybrid surface adhesion promoter is particularly suited for application in improving the processing and promoting adhesion of organic materials on silicon, glass, ceramic, and metal, especially, in the fabrication of high quality organic waveguides.
[0004] 2. Description of the Prior Art
[0005] Processability and interfacial adhesion are two important issues when an organic material, whether as coating, adhesives or bulk, is applied onto an inorganic substrate. Processability is directly related to organic material's nature and is significantly affected by the substrate surface. Wettability and spreading are, for instance, two substrate-related processing issues. Only when the substrate surface energy is matched with the material to be applied, can good wetting and spreading, which are essential for coating quality, for example, be achieved for the material. Interfacial adhesion is dependent on the surface energy matching and chemical bonds between the organic materials and inorganic substrate. While a good matching in surface energy can enhance the interfacial adhesion by physical force (i.e. Van der Waals force), chemical bonds directly provide strong inter-chemical connection between different materials.
[0006] Ideally, the organic material or the inorganic substrate can be modified chemically to satisfy the requirement in processability and interfacial adhesion. In many cases, such chemical modification is not allowed and a surface treatment agent, coupling agent, or adhesion promoter is used to help the processing and interfacial adhesion. These promoters are usually small molecules based. Typical commercial chemicals for treating glass substrate are silanes, e.g γ-aminopropyl triethoxysilane and γ-methacryloxypropyl-trimethoxysilane. One end of these promoters can chemically react with glass while another end has a strong physical interaction or even chemical reaction with the organic materials to be applied on top. Most of the glass and carbon fibres used for manufacturing fibre/polymer composites, are, for instance, coated with some small molecular surface adhesion promoters. HMDS (1, 1, 1, 3, 3, 3-Hexamethyldisilazane) is widely used in treating silica wafers before coating photo-resist in semiconductor industry.
[0007] While small molecular surface adhesion promoters have been widely used in various applications, e.g. fibre/polymer composites, macromolecular surface adhesion promoters are seldom used. Macromolecular surface adhesion promoters, in fact, have many advantages. First of all, macromolecular ones have a good coverage on the substrate because a relative thick layer of the macromolecules can be easily deposited on substrate. This is important in guaranteeing the quality in treating a large substrate surface. Secondly, in addition to adhesion promotion, they can act as a stress relaxation interfacial layer which is useful in damping impact energy and avoid crack propagation in the top materials and even substrates. In this case, the promoters should have short intrinsic molecular relaxation time and should usually have low glass transition temperature (Tg). It is well accepted that an interface with strong interfacial bonding and a tough interfacial layer is the idea interface in fibre or particulate reinforced composites. Also, macromolecular surface adhesion promoters can also act as expansion transition layer between substrate and the organic materials to be applied on top. If the thermal expansion between the organic materials and substrate is mismatched, a stress which could develop in the materials and cause cracks in the materials can develop. For instance, when a UV curable sol-gel coating is deposited on silica for fabrication waveguides, the coating can easily develop cracking when it is heated to 130 to 170° C. for curing. The coefficient of thermal expansion (CTE) is around 10×10 −6 for sol-gel and 5.5×10 −7 for silica and is substantially mismatched between the two materials. A layer of ductile surface adhesion promoter which has similar CTE with the sol-gel coating will be able to reduce the thermal stress in the coating.
[0008] In comparison with small molecular ones, macromolecular surface adhesion promoters have some disadvantages, including, the difficulty in structure design and synthesis, strong selection to the materials, and high requirement in processing. Macromolecules have more complicated structure than small molecules do. There are first order, second order, and even third order structure for macromolecules and only first order structure for small molecules, which brings a lot difficulty in designing and synthesizing macromolecular promoters. Also, due to their long molecular chains, there is a compatibility issue at their interface with the top materials and the rheology of the macromolecules is related to their molecular weight as well as molecular texture.
[0009] It is well-known that metal alkoxides could be hydrolyzed and condensed to form glasses. It was also known that silica could be produced in-situ as a chemical of compounds e.g., tetraethylorthosilicate (TEOS). It was also known partially to hydrolyze silicon alkoxide with acid and metal oxide to prepare a glass precursor which could be fired to a glass composition at a temperature of above 1000 degree. The prior art also described the preparation of clear alcohol solution of acid hydrolyzed metal alkoxide which can be coated on the substrate and dried to produce an optical coating. Silane coupling agents are also known to provide a useful means to crosslink organic and inorganic surfaces and particles.
[0010] The “sol-gel” method provides a teaching that the condensation of reactive metal oxide monomers can occur in the liquid phase at temperatures in the range of 25.degree.- 60.degree. C. The sol-gel reaction is a two-step process during which metal alkoxides are hydrolyzed to form metal hydroxides, which in turn condense to form a three-dimensional network.
[0011] The sol-gel method allows the formation of hybrid composite materials made of inorganic (glass) and organic components which would not survive the very high temperatures of traditional glass making methods. Such a composite material can provide advantages resulting from the combination of the tensile strength and impact resistance of the organic polymer and the compressive of strength of the inorganic matrix. The introduction of organic groups into glass can thus provide variations in properties such as strength, toughness, stiffness, brittleness, hardness, homogeneity, density, free volume, and thermal stability. Secondary considerations include resistance to corrosion, creep, and moisture. Both the strength and stiffness of a composite can be derived from the properties of the reinforcing fiber. Toughness results from the interaction between the matrix and fibers. Such composite materials may be used in the manufacture of piezoelectric, ferroelectric, electro-optic, and superconducting fibers and films.
[0012] Organic-inorganic hybrids have recently attracted substantial attention due to the potential of combining distinct properties of organic and inorganic components within a single molecular composite.
[0013] There is a need for simple and inexpensive thin film deposition techniques. One of the key difficulties depositing thin films of organic-inorganic hybrids is the distinctly different character of the organic and inorganic components with regard to potential film forming processes. Organic materials tend to be soluble in solvents which are not, in general, the same as those appropriate for the inorganic component, making it's often impractical to find a suitable solvent to enable the solution deposition techniques (e.g. spin-coating). Additionally, organic compounds tend to decompose at relatively low temperature, where as inorganic materials often do not effectively evaporate until much higher temperatures.
[0014] U.S. Pat. No. 5,120,811 issued Jun. 9, 1992 to Glotfeller et al. provided a polymer/glass hybrid coating consisting essentially the reaction product of an acid-catalyzed hydrolysis product of a metal alkoxide selected from the group consisting of tetramethylorthosilicate, tetraethylorthosilicate and tetrapropylorthosilicate, and an acid-catalyzed hydrolysis product of a coupling agent having a metal alkoxide functionality and inorganic functionality, the organic functionality of the coupling agent being selected from the group consisting of acrylic, methaylic and epoxy moieties.
[0015] U.S. Pat. No. 5,178,675 issued Jan. 12, 1993 to Sexsmith provided on adhesive composition useful for bonding various substrates which contain alkoxy silane compound and an unsatutated acid compound. A preferred embodiment of the invention is an aqueous formulation containing a low molecular weight alkoxy silane compound, a low molecular weight unsaturated acid compound, and water. An example alkoxy silane compound is aminopropyl triethoxysilane while an example of the unsaturated acid compound is methacrylate acid The adhesives composition is particularly effective in bonding non-sulfurcured elastomeric materials such as polyol- and peroxide-cured elastomers to metal surfaces. That product is an adhesive composition useful for bonding various substrates which contain an alkoxy silane compound and an unsaturated acid compound. A preferred embodiment is an aqueous formulation containing a low molecular weight alkoxy silane compound, a low molecular weight unsaturated acid compound, and water. An example of alkoxy silane compound is aminopropyl triethoxysilane while an example of the unsaturated acid compounds is methacrylic acid. The adhesive composition is particularly effective in bonding non-sulfurcured elastomeric materials such as polyol- and peroxide-cured elastomers to metal surfaces.
[0016] U.S. Pat. No. 5,231,156 issued Jul. 27, 1993 to Lin provided an organic-inorganic hybrid polymer comprising the reaction product.
[0017] 5 to 25 percent by weight of an organofunctional alkoxy silane up the general formula are 95 to 75 percent by weight of an organic monomer capable of reaction with the organofunctional and polymerization, alkoxysilane hydrolyzes and condenses to form the inorganic polymer portion and the organic monomer reacts to what the organofunctional radical and further polymerizes to form the organic polymer portion of the organic-inorganic hybrid polymer.
[0018] U.S. Pat. No. 5,868,966 issued Feb. 9, 1999 to We et al. provided by hybrid materials which were formed having a homogenous distrbution of a conductive organic polymer or copolymer in an inorganic matrix. The conductive organic polymer may be electronically conductive, e.g., poyaniline, or way be ionically conductive, e.g., sulfonated polystyrene. The inorganic matrix is formed as a result of sol-gel chemistry, e.g., by the hydrolysis and condensation of tetraethyl orthosilicate and trialkoxysilyl groups in the organic polymers. A homogenous distribution of organic polymer in the inorganic matrix is achieved by preparing separate solutions of organic polymer and homogenous clear solution. Upon evaporation of the solvent and other volatiles, a monolithic hybrid material may be formed. The combination of conductive organic polymer in an inorganic matrix provides desirable adhesion properties to an inorganic substrate while maintaining the conductivity of the organic polymer. The term organic inorganic hybrid materials embrace two types of hybrids. In the firs, covalent bonding occurs between an organic polymer and an inorganic matrix, and such hybrids will be referred to as covalent hybrids. An oxygen atom, which is commonly found in both organic polymers and inorganic matrices, is typically employed to link the organic and inorganic components of the covalent hybrid. In a second type of hybrid, the organic polymer and inorganic matrix are intimately mixed together, i.e., the organic polymer uniformly dispersed throughout and inorganic matrix, or vice versa. The second type of hybrid, which does not contain a covalent bond between organic and inorganic components, will be referred to as dispersion hybrids. Covalent and dispersion hybrids are to be distinguished from conventional composite materials arm from organic and inorganic materials, with conventional composite materials have microscopic interfaces.
[0019] The development of sol-gel chemistry, which occurred during the past two decades has provided a convenient entry into the organic matrices of hybrid materials.
[0020] U.S. Pat. No. 5,973,176 issued Oct. 26, 1999 to Roscher et al. provided organically modified silanes which are hydrolysable, which by themselves, in mixtures or together with other hydrolyzable and/or condensable compounds may be processed into scratch-proof coatings, fillers, adhesives or caulking compounds, into formed articles or imbedding materials. The silanes are to be universally applicable, and they are to be incorporable into an organic-organic compound system, i.e. an inorganic-organic network. Furthermore, the silanes by themselves, in mixtures or together with other hydrolyzable and/or condensable compounds to yield hetero silicic acid polycondensates of good adhesive and U.S. Pat. No. 5,412,043, issued May 2, 1993 to Novak et al. provided an inorganic-organic composite material having a solid interwoven of an inorganic polymer matrix with interpentratng polymerized alcohols in which the organic matrix can be baeed on either Si or Ti atoms, which can be prepared by way of sol-gel procedure. The sol-gel reaction is a two-step process during which metal alkoxides are hydrolyzed to form metal hydroxides, which in turn condense to form a three-dimensional network. The sol-gel products of inorganic components are generally to produce hard and brittle glass. Sol-el method allows the formation of hybrid composite materials made of inorganic (glass) and organic components which would not survive the very high temperatures of glass making methods. Such a composite material can provide advantages resulting from the combination of tensile strength and impact resistance of the organic polymer and compression strength of the inorganic matrix. The introduction of organic groups into glass can thus provide variations in properties such as strength, toughness, stiffness, brittleness, hardness, homogeneity, density, three volume, and thermal stability. Secondary considerations include resistance to corrosion, creep, and moisture. Both the strength and stiffness of a composite can be derived from properties of the reinforcing fiber. Toughness results from the interaction between the matrix and the fibers. Such composite materials may be used in the manufacture of piezoelectric, ferroelectric, electro-optic, and superconducting fibers.
[0021] U.S. Pat. No. 5,631,331 issued May 20 at 1997 to Sakamara et al. provided organic-inorganic hybrid polymer having a structure of organic polymers bonded through siloxane linkages, sometimes called “ormosil” or “creamer”, has excellent properties including high mechanical strength, high heat resistance, flame retardancy, light-fastness and so on so that polymers of this type are promising and under extensive development works a constituent of coating compositions, material of structural members for high-temperature service and the like. The properties of these organic-inorganic hybrid polymers are intermediate of organic polymers, i.e. plastic resins, and inorganic materials, i.e. glass and ceramics, so that the application fields thereof are expected to cover those in which satifactory performance can be exhibited by none of the conventional organic materials and inorganic materials as well as mere combinations thereof.
[0022] This patent provided a novel and improved method for the industrial preparation of a silicon-containing polymer having a structure of organic polymers bonded through siloxane linkages and exiting excellent heat resistance in a simple and convenient process by using an inexpensive starting material of good availability. temperature properties and good optical attenuation values so that these hereto silicic acid polycondensates are suitable for optical or opto-electronics.
[0023] U.S. Pat. No. 6,005,028 issued Dec. 21, 1999 to Paul, provided alkoxides with polymerizable groups are single source precursors for organic-inorganic hybrid composites possessing good mechanical properties. Additional function groups of the alkoxides provide enhanced adhesion to other surf such as dentin. The selection of specific organic monomers having functional groups that are responsible for enhances properties of the organic-inorganic hybrid composites is important. Single source precursor containing the desired functional groups are condensed and polymerized into the organic-inorganic hybrid composites with enhanced properties.
[0024] U.S. Pat. No. 6,066,269 issued May 23, 2000 to Wer et al. provided hybrid materials which were formed having a homogenous distribution of a conductive organic polymer or copolymer in an inorganic matrix. The conductive organic polymer may be electronically conductive, e.g, polyaniline, or may be ionically conductive, e.g., sulfonated polystyrene. The inorganic matrix is formed as a result of sol-gel chemistry, e.g., by the hydrolysis and condensation of tetraehyl orthosilicate and trialkoxysilyl groups in the organic polymers. A homogenous distribution or organic polymer in the inorganic matrix is achieved by preparing separate solutions of organic polymer and sol-gel monomer, and then combining those solutions with a catalyst and stirring, to form a homogenous clear solution. Upon evaporation of the solvent and other volatiles, a monolithic hybrid material my be formed. The combination of conductive organic polymer in an inorganic matrix provides desirable adhesion properties to an inorganic substrate while maintaining the conductivity of the organic polymer.
[0025] These inorganic organic hybrids are the reaction product of hybrid forming components including organic polymer, sol-gel monomer, catalyst and solvent, where the solvent is preferably aqueous. The solvent provides for a homogenous distribution of organic polymer and sol-gel monomer in a solution, and thus the resulting hybrid material will likewise have a homogenous distribution of organic polymer in the inorganic matrix that forms from the sol-gel monomer. The catalyst is present to promote the hydrolysis and condensation chemistry that is necessary to convert the sol-gel monomer into the morganic matrix. The sol-gel monomer reacts with itself to form an inorganic matrix, which because it typically has a high glass transition temperature, is also referred to as a glass or inorganic glass. The organic polymer either has functionality that imbues with conductive properties, for example electronically or ionically conductive properties, or has a structure that may react and thereby be converted to an organic polymer having conductive properties. In a preferred embodiment, the organic polymer comprises functional groups that react with the sol-gel monomer, so that covalent bonding is formed between the organic polymer and the inorganic matrix.
[0026] U.S. Pat. No. 6,103,854 issued Aug. 15, 2000 to Arakawa et al. provided an organic-inorganic hybrid polymer material obtained by the process in which a polymer having a polycarbonate and/or a polyarylate moiety as a main frame, a metal alkoxide group as a functional group, a number average molecular weight of from 500 to 50000 as measured by GPC, and a metal alkoxide group equivalent weight of form 1 to 100, is hydrolyzed and polycondensed to form crosslinkages wherein the organic-inorganic hybrid polymer material has high heat resisiance mechanical strength, water resistance and surface hardiness.
[0027] U.S. Pat. No. 6,117,498 issued Sep. 123, 2000 to Chondroudis et al. provided a method of forming a film of an organic-inorganic hybrid material in a selected stoichiometric ratio upon a surface of substrate, the proposed method entails a number of simple steps. First, a subrate and a selected quantity of an organic-inorganic hybrid material are placed in a chamber, with the hybrid material being placed on a heater. Then, the hybrid material is heated sufficiently, as by passing an electric current through the heater, to cause its total ablation. As a consequence, a film of the organic-inorganic hybrid material, in the aforesaid selected stoichiometric ratio, reassembles as a film upon a surface of a substrate.
SUMMARY OF THE INVENTION
AIMS OF THE INVENTION
[0028] An object of the present invention is to provide an organic-inorganic hybrid macromolecular surface adhesion promoter that, in addition to the advantage of regular macromolecular surface adhesion promoter, can be easily designed and synthesized, is thermally very stable, have the physical properties falling between those of organic polymer and inorganic materials.
[0029] Organic-inorganic hybrids are a new class of materials developed to fill the gap between organic polymers and inorganic materials, such as ceramics. Generally, there are two types of organic-inorganic hybrids in terms of interaction: those without covalent bonding but with good compatibility and strong physical interaction between organic part and inorganic part and those with covalent bonding between the two phases. In the hybrids, the organic part is phase separated from the inorganic part, and the phase domain for each phase is in nanometer scale. Consequently, the hybrids are also called nano-composites. Organic-inorganic hybrids are usually synthesized by sol-gel process and the materials have been used as wear resistant coating, films, bulk materials, matrix for fibre composites, waveguides, and other applications.
STATEMENT OF THE INNENTION
[0030] In general terms, the present invention provides a surface adhesion promoter in the form of an organic-inorganic hybrid whose moleceles are composed of organic part on one end and inorganic chains on the other end, with the organic part chemically connected inorganic part by covalent bonds. In general terms
[0031] The organic part has good compatibility and can even react with organic materials which may be applied there were. The inorganic part can react with the substrates to form Si—O—Si M-O-M, M-O—Si, or Si—O-M (where, M stands for metal atom) connection
[0032] The organic part generally conssts of highly branched or lowly crosslinked network with some organic end groups hanging outside the network. The inorganic part generally includes a hydroxide end functional group. The inorganic part is also highly branched or lowly crosslinked.
[0033] The promoter is synthesized by sol-gel process. This strategy is to synthesize the organic part first and then connect inorganic part to the organic part by chemical reaction.
OTHER FEATURES OF THE INVENTION
[0034] The adhesion promoter can be easily designed, synthesized and processed. In addition to its adhesion promotion function, the promoter can also act as a transit interlayer between substrate and top layer of polymer.
GENERALIZED DESCRIPTION OF THE INVENTION
[0035] The surface promoter is synthesized by first hydrolyzing and polycondensing a trioxysilane (R—Si(OR′) 3 ) or its mixture with another one or two silanes with acid or base as catalyst, where R is an organic group which has similar chemical structure to the organic materials to be applied on top and/or can chemically react with the materials to form covalent bonding, and R′ is methyl, ethyl, and propyl.
[0036] If epoxy is to be applied thereover, the silane could be [3-(glycidyloxy) propyl] trimethyloxysilane. The 3-(glycidyloxy) propyl has a good compatibility with epoxy and can react with epoxy resin, coating, or adhesives to form strong covalent bonds.
[0037] If polytetrafluroethylene (PTFE) is to be applied thereover as a coating, the silane could be (tridecafluro-1,1,2,2-tetrahydro-oetyl) triimethyloxysilane.
[0038] If the organic material to be applied is a coating contains two distinct chain units, another one or two silanes are needed. For, instance, if unsaturated polyester resin is going to be applied, 10-15% diphenyldimethoxysilane could be added in two methacryloxypropyltrimethoxysilane for co-poly condensation. While methacryloxypropyl can react with the double bonds in unsaturated polyester, the diphenyl groups improve the compatibility between the surface promoter with the resin.
[0039] In order fully to hydrolyze the silanes, extra water is usually added. H 2 O can be used for all kinds of applications, except for the application in optical telecommuncaton because O—H bond has a very strong absorption between 1.3 and 1.55 μm wavelength, both of which are the communication working wavelength. In this circumstance, deuterium dioxide D 2 O, instead of H 2 O, can be applied.
[0040] Inorganic acids, e.g., HCl and H 2 SO 4 , and organic acids, eg., acetic acid are ideal acid catalysts while inorganic bases, e.g., NAOH, and organic bases, e.g., NEt 4 OH are ideal base catalyst. pH of 2-5 for an acid-catalyzed reaction and pH 8-11 for base catalyzed reaction are the desired levels. The reaction can be carried out in bulk, i.e. in the absence of a solvent, or in solvent. Organics, solvents, e.g., MeOH, EtOH, THF, and Acetone, are all suitable solvents for the reaction.
[0041] Experimentally, the reaction is started with charging silanes into a two necks or a three necks flasks and adding certain amount of acid or base so that the desired pH value can be met. After connecting a flux tube to the flask, water with 1.05-1.20 times of the theoretical amount is added into the flask during stirring, followed by bring the mixture to the desired temperature. Reaction could be carried out at room temperature to 110° C. In case a solvent is used, the boiling point of the solvent is a good reaction temperature. 65° C., for example, can be the reaction temperature when MeOH is used as solvent. Simply, the heater is adjusted so that the solvent is boiled and refluxed during the reaction. Reaction time is 5-24 hrs, depending on the catalyst and reaction temperature. Base and high reaction temperatue are both in favor of reaction kinetics, thus, short reaction.
[0042] When the reaction reaches a certain degree and the product is viscous if all the solvent and byproducts are removed, 5-30% of another silane or metal alkoxides are gradually added into the solution for co-polycondensation. Tetramethoxysilane and tetraethoxysilane are typical silanes used for synthesizing silicon containing surface adhesion promoter, and the metal alkoxides with long chain alkyl-groups are suitable for synthesizing metal containing promoter. Aluminum butoxide, zirconium propoxide, titanium butoxide, and zirconium butoxide are the examples of suitable metal alkoxides.
[0043] The selection of silane or metal oxides depends on the substrate to be worked on. When the substrate is glass, silica or silicon, silane, such as tetramethoxysilane and tetraethoxysilane, is chosen. This step of reaction is to connect inorganic part to the synthesized inorganic part. When the substrate is a metal like aluminum, for instance, alminum butoxide can be selected. If the thermal expansion mismatch between the organic materials and substrate is insignificant, the selection of siline and metal alkoxides is not critical and the silane and metal alkoxides could be inter-replaceable.
[0044] Before adding the above silane or metal alkoxides, a solvent should be added into the solution to reach a ratio of solvent to raw chemicals of 0.5:1 to 3:1. After stirring for 2-7 hrs, water, with theoretically required amount for the silane or metal alkoxides, is added into the solution to fully hydrolyze the silane or metal alkoxides. The resulted solution is then aged at room temperature for 24 hrs or longer before it is ready for use. Some H—O—Si or H—O-M end groups will be left in the promoter and will be the important function groups reacting with substrates.
[0045] After the aging, the obtained surface adhesion promoter is diluted with a solvent which is the same as that added during the reaction, and may be directly applied on the substrate, e.g., silica, glass, silicon wafer, aluminum, by dipping coating, spinning coating, or spraying, depending on the quality requirement. If the top organic material is going to be deposited as high quality film or coating for instance, dipping coating and spinning coating are suitable technologies for applying the promoter. The preferred thickness for the promoter is 0.2 to 3 μm. A thermal treatment at 90-150° C. is required to enhance the reaction between the promoter and the substrate. Si—O—Si M-O—Si, Si—O-M, or M-O-M bonds can be formed between the promoter and substrate. When the treatment is completed, the top organic materials can be applied.
[0046] The inorganic matrix of the inorganic organic hybrid materials of the invention is prepared using sol-gel chemistry. Monomers that may be employed in sol-gel chemistry numerous and well-known in the art, and are referred to herein as sol-gel monomers. Any of the monomers that are conventionally employed to prepare an inorganic marix by way of sol-gel chemistry, may also be employed to prepare the inorganic matrix of the inorganic organic hybrid materials of the invention. Exemplary sol-gel monomers include, without limitation, tetraethyl orthosilicate (TEOS), titanium tetraisopropoxide (TIPO), aluminum tri-sec-butoxide (ASBO), silicon tetrachloride, titanium tetrabutoxide, titanium(IV) bis(ethyl acetate) silicon(IV) aceate, silicon(IV) acetylacetonate, triethoxyhydrosilane, hexachlorodisiloxane, titanium(IV) ethoxide, titanum(IV) butoxide, titanium(IV) chloride, titanium(IV) 2-ethylhexoxide, titanium(IV) oxide acetylacetonate, titanium diisopropoxide bis(2,4-pentanedionate), titanium(IV), (triethanolaminato)isopropoxide, zirconium(IV) tert-butoxide, zirconium (IV) acetylacetonate, zirconium (IV) ethoxide, rubidium acetylacetonate, ruthenium (III) acetylacetonate, niobium(IV) ethoxide, vanadium (IV) oxytriethoxide, tungsten hexaethoxide, etc.
DESCRIPTION OF PREFERRED EMBODIMENTS
[0047] The following are examples of preferred embodiments of the invention.
EXAMPLE 1
[0048] 30 g of 3-(trimethoxysilyl)propyl methacrylate (TMSPM) was charged into a 250 ml three necks flask. After adding small amount of 37% HCl as catalyst, 6.7 g H 2 O was gradually dropped into the solution during magnetic stirring. The reaction was kept at 65 to 70° C. for 7 hrs. The solution was then cooled down to room temperature, followed by the addition of 30 ml ethanol and 2.5 g tetraethoxysilane (TEOS). The solution was stirred for 3 hrs at room temperature. Afterwards, 1 g H 2 O was added into the solution. After 24 hrs stirring, the solution was ready for use.
[0049] The surface adhesion promoter was applied on silicon wafer and glass to help the processing of various methacrylate containing polymers and sol-gel materials, and promote the adhesion between the materials and substrate. High surface quality and good adhesion was achieved when the surface adhesion promoter was applied in processing some methacrylate containing organic waveguide materials.
EXAMPLE 2
[0050] 15 g of 3-(trimethoxysilyl)propyl methacrylate (TMSPM) and 10 g of diphenydiethoxysilane (DPDES) were charged into a 250 ml three necks flask and mixed. After adding small amount of 37% HCl as catalyst, 6.3 g of D 2 O (deuterium dioxide) was gradually added into the mixture. The reaction was kept at 58° C. for 7 hrs. Then, 50 ml acetone was added into the solution at room temperature, followed by 2 g of tetraethoxysilane (TEOS). 4 hrs later, 1 g of D 2 O was gradually into the solution and the solution was kept stirring at room temperature for 24 hr.
[0051] The surface adhesion promoter was applied on silicon wafer, silica and glasses to help the processing and promote adhesion of the sol-gel waveguides synthesized from TMSPS and DEDES. The surface roughness of the undercladding and core were achieved at 0.1 μm after applying the promoter, which is difficult for thick sol-gel coatings. Also, no any delamination was observed after the waveguides were exposed to thermal cycle from room temperature to 170° C. and mechanical cut, i.e. dicing, and the cleaning with water and compressed air.
EXAMPLE 3
[0052] 30 g of 3-glycidoxypropyltrimethoxysilane (GPTMS) and 20 ml were charged into a 250 ml three necks flask and mixed. After tetramethylammonium hydroxide (TMAH) as catalysts 7.2 g of H 2 O was gradually added into the mixture. The reaction was kept at 50-65° C. for 5 hrs. Then, 20 ml ethanol was added into the solution at room temperature, followed by adding 4 g of aluminum butoxide. After being stirred for 4 hrs, 1 g of H 2 O was gradually into the solution and the solution was kept stirring at room temeature for 20 hr.
[0053] The surface adhesion promoter was applied on silicon wafer, aluminum and glasses to help the processing and promote adhesion of epoxy resin.
EXAMPLE 4
[0054] 17.5 g of vinyl-triethoxysilane (VTES) and 12.5 g of diphenydiethoxysilane (DPDES) were charged into a 250 ml three necks flask and mixed. HCl was used as catalyst and 6.8 g of H 2 O was used for hydrolysis. The reaction temperature and time were 80° C. and 9 hrs, respectively. Ethanol was used to dilute the solution before 5 g TEOS was added for polycondensation. Additional water of 2 g was used to fully hydrolyze residual TEOS and the resulted solution was aged, while kept stirring, at room temperature for 24 hrs. before being applied on glasses and silicone.
CONCLUSION
[0055] The surface adhesion promoter of the pressnt invention has many advantages, including all the advantages for macromolecular surface adhesion promoter as described above, the benefits from organic-inorganic hybrids, and the simplicity in molecular store design and synthesis. Since all the chemicals used for synthesizing the surface adhesion promoters have very good market availability, the production cost is also lower. Its application can be used in the areas that regular small molecular surface adhesion promoters are used, and can be also used as specialty surface adhesion promoter in the area where high performance is required. Ductile fibre-resin interface in high performance composites used in aerospace, and thermal expansion transition interface in organic waveguides on silicon wafer are two examples.
[0056] The application in fabricating organic waveguides is the most preferred area for the organic-inorganic hybrid surface adhesion promoter because the materials are very difficult in processing, while very high quality is required for the products. Organic materials, especially, have to be fluorinated in order to reduce their optical loss at the communication wavelength, such as 1550 nm and 1300 nm. Fluorinated materials have low surface energy and poor wetability and adhesion with silicon and silica, which are the common substrates for fabricating waveguides, easily, resulting in rough surface and delimitation. Waveguides are manufactured by coating organic materials layer by layer on highly polished silicon and silica. The surface roughness of under cladding and core has to be controlled to very low lever to reduce propagation loss. It is extremely difficult to achieve such high surface quality coatings by depositing low surfrce energy materials on high surface energy substrates. Also, waveguide fabrication process usually experiences some high temperature, over 200° C. for polyamide, for instance, and the fabricated waveguide samples will experience cutting and other tough post process for package. Delamination could easily occur during the processes if the adhesion is not good enough, and if there is no stress relaxation and thermal expansion transition mechanism at the interface. It was the initial tendency of this invention to develop a surface adhesion promoter and apply it in fabricating organic waveguides.
[0057] Thus, by the present invention, a series of silicon containing and metal containing organic-inorganic hybrids have been developed for promoting the adhesion between hydrophilic substrates, e.g silicon wafer, silicate, glass, metal oxide, ceremics, and metals, with sol-gel and polymer coatings, adhesives, and bulks. The hybrids consist of hydrophilic Si—O—Si or M-O-M inorganic network, where M stands for metal atoms, e.g., Al, Ti Zr, and Er, and hydrophobic organic sectors. There are chemical bonds between the inorganic and organic parts. It is flexible to design and prepare the hybrids according to the nature of the substrates, and the coatings, adhesives, or bulks to be applied on the substrates. The methodology is to connect hydrophilic inorganic parts, by a sol-gel process, with hydrophobic organic groups, identical or similar to those in the coatings to be applied. The former part provides a good adhesion with substrates while the later one provides the wetting and adhesion with the materials to be applied. Since the surface promoter is macromolecular, it serves as a transition layer between inorganic substrate and the materials to be applied. The hybrids can be easily applied on the substes prior to the coatings, adhesives, or bulks to be applied. Such hybrid adhesion promoter can also significantly improve the processability and quality of the coatings which are inert to hydrophilic substrates. Organic waveguide fabrication is the most preferred application of the surface adhesion promoter. Exemplary acrylate and methacrylate monomers that may be used in this invention include, without limitation, 3-(trimethoxysilyl)propyl methacrylate, 3-triethoxysilyl)propyl methacrylate (ESMA), methacryloxypropyltris(pentamethyldisiloxanyl)silane, 3-acryloxypropyldimethylmethoxysilane, N-(3-acryloxy-2-hydroxypropyl)3-aminopropyltriethoxysilane, 3-acryloxpropyltrimethoxysilane, 3-acryloxypropyltrichlorosilane, 2-methacryloxyethyldimethyl-3-trimethoxysilyl propylammonium chloride, 3-methacryloxypropyltris(methoxyethoxy)silane, methacrylozypropenyltrimethoxysilane, 3-methacryloxypropylmethyldiethoxysilane and methacryloxypropylmethyldichlorosilane.
[0058] Exemplary shyrene and styrene derivatives that may be employed on this invention include, without limiteation, styrylethyltimethoxysilane (STMS), styrylethyltriethoxysilane, syrylethyltriechlorosilane, styrylpropyltrimethoxysilane and styrylpropyldimethylethoxysilane.
[0059] Examples of alkoxy silane compounds used in the present invention include:
[0060] 1. 3-Trimethoxysilyl)propyl methacrylate
[0061] 2. 3-Glycidoxypropyltrimethoxysilane
[0062] 3. 3-Aminopropyltrimethoxysilane
[0063] 4. 3, 3, 3-Trifluoropropyl-trimethoxysilane
[0064] 5. 2-(3,4-Epoxycyclohexyl)ethyl-trimethoxysilane
[0065] 6. gamma-Methacryloxypropyltrimethoxysilane
[0066] 7. Isobutyl-trimethoxysilane
[0067] 8. (3-Bromopropyl)trimethoxysilane
[0068] 9. (3-Mercaptopropyl)trimethoxysilane
[0069] 10. Phenyltrimethoxysilane
[0070] 11. Vinyltrimethoxysilane
[0071] 12. (3-Glycidyloxypropyl)triethoxysilane
[0072] 13. 3-Aminopropyltriethoxysilane
[0073] From the forgoing description one skilled I the art can easily ascertain the essential characteristics of this invention, and without departing from the spirit and scope thereof, can make various changes and modifications of the invention to adapt it to various usages and conditions. Consequently, such changes and modifications are properly, equitably, and “intended” to be, within the fill range of equivalence of the following claims.
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An organic-inorganic hybrid surface adhesion promoter having the general formula, A-B, wherein A is hydrolyzed and polycondensed from a trioxysilane R-Si(OR′) 3 or its mixture with one or two more silanes, where R′ is methyl, ethyl or propyl, and where R is an organic group of methacrylate, epoxy, amine, isolyante, hydroxide or non-halogens or halogens containing alkyl, alkenyl, aryl, alkylary or arylalky, and wherein B is hydrolyzed and polycondensed from an alkoxy silane, chloride silane, or alkoxy or chloride metal compound, whereby B reacts with a substrate to form a uniting group which is selected from the group consisting of Si—O—Si, M-O-M, M-O—S and Si—O-M, M being a metal atom.
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FIELD OF THE INVENTION
[0001] The present invention relates to a mobile apparatus, a geographical information system and a method of acquiring geographical information, and more particularly to those acquiring related geographical information and services by a geographical object message.
BACKGROUND OF THE INVENTION
[0002] As our living standard improves drastically in recent years, people pay more attention to leisure activities, and taking a trip becomes one of the major leisure activities. To ensure consumers to have a successful trip, various different means are developed, such as global positioning system (GPS). GPS was originally intended for military purpose, but now it is used extensively in civil navigation due to its practicability. On the other hand, consumers who go out for a trip generally need a tourist guide for providing information on scenic spots and related routes.
[0003] A terminal of a conventional global positioning system can position an object or a place on a map based on the wireless signal from a plurality of GPS satellites and provide a map related hint function, wherein the hint function produces a hint signal for each location by comparing a positioning signal and a data stored in the terminal and displays the hint signal on the map.
[0004] Although the conventional global positioning system can provide navigation and positioning functions, users cannot acquire their desired information from a direct viewing. In view of the shortcomings of the prior art, the inventor of the present invention based on years of experience to conduct extensive researches and experiments, and finally developed a mobile apparatus, a geographical information system and a method of acquiring geographical information in accordance with the present invention. Derived from the traditional concept of hinting a fixed point, the present invention provides users the required geographical information. Therefore, a user taking a trip no longer needs the service of a tourist guide to enjoy the scenic spots, and the present invention definitely improves the degree of freedom of a trip and effectively manages personal time.
SUMMARY OF THE INVENTION
[0005] An objective of the present invention is to provide a mobile apparatus, a geographical information system and a method of acquiring geographical information, and more particularly to related geographical information and services acquired by a geographical object message.
[0006] To achieve the foregoing objective, the invention provides a geographical information system for acquiring geographical information of a geographical object, and the system comprises a geographical object message and a mobile apparatus, wherein the geographical object message is provided by the geographical object, which is usually an identification code or an image. After the mobile apparatus receives and identifies the geographical object message, the mobile apparatus generates an inquiry command. The geographical information corresponding to the inquiry command is searched from a database of the mobile apparatus based on the inquiry command to display the searched geographical information on the mobile apparatus.
[0007] To achieve the foregoing objective, the present invention also provides a geographical information system for acquiring geographical information of a geographical object, and the system comprises a geographical object message, a mobile apparatus and an information center, wherein the geographical object message is provided by the geographical object, and can be an identification or an image. After the mobile apparatus receives and identifies the geographical object message, the mobile apparatus generates an inquiry command, and sends out the inquiry command by a communication module of the mobile apparatus. After the information center receives the inquiry command, the information center searches the geographical information corresponding to the inquiry command and sends the searched geographical information to the mobile apparatus for display.
[0008] To achieve the foregoing objective, the present invention further provides a mobile apparatus comprising a device body, a database, a capture identification module, a communication module and a processor. The device body provides basic operating functions for the mobile apparatus, and the database, the capture identification module, the communication module and the processor are installed in the device body. The database stores the geographical information of at least one geographical object. The capture identification module acquires the geographical object message of the geographical object from outside and identifies the geographical object message to generate an inquiry command. The communication module is provided for sending the inquiry command and obtains the geographical information from outside. After the processor receives and processes the inquiry command, the processor transmits the inquiry command to the database to search the geographical information corresponding to the inquiry command, or the processor transmits the inquiry command to the communication module.
[0009] From the foregoing objective of the present invention, the invention derives a method of acquiring geographical information that is applied to a mobile apparatus for displaying geographical information, and the method comprises the steps of: acquiring a geographical object message of a geographical object from outside; generating an inquiry command after the geographical object message is identified; searching geographical information corresponding to the inquiry command from a database based on the inquiry command or searching geographical information corresponding to the inquiry command from an information center based on the inquiry command; and displaying the geographical information on the mobile apparatus.
[0010] In summation of the description above, the present invention adopts the geographical object message to provide a direct viewing of the user's required geographical information and related services, and improve the degree of freedom of a trip and effectively manage personal time.
[0011] To make it easier for our examiner to understand the objective of the invention, its structure, innovative features, and performance, we use a preferred embodiment together with the attached drawings for the detailed description of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
[0012] FIG. 1 is a schematic view of a geographical information system in accordance with the present invention;
[0013] FIG. 2 is a schematic view of a geographical information system in accordance with a first preferred embodiment of the present invention;
[0014] FIG. 3 is a schematic view of a geographical information system in accordance with a second preferred embodiment of the present invention;
[0015] FIG. 4 is a schematic view of a geographical information system in accordance with a third preferred embodiment of the present invention;
[0016] FIG. 5 is a schematic view of another geographical information system of the present invention;
[0017] FIG. 6 is a schematic view of another geographical information system in accordance with a first preferred embodiment of the present invention;
[0018] FIG. 7 is a schematic view of another geographical information system in accordance with a second preferred embodiment of the present invention;
[0019] FIG. 8 is a schematic view of another geographical information system in accordance with a third preferred embodiment of the present invention;
[0020] FIG. 9 is a schematic view of a mobile apparatus of the present invention;
[0021] FIG. 10 is a flow chart of a method of acquiring geographical information of the present invention; and
[0022] FIG. 11 is a flow chart of a method of acquiring geographical information in accordance with a preferred embodiment of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0023] In the related figures of preferred embodiments of a mobile apparatus, a geographical information system and a method of acquiring geographical information of the present invention, the same referring numerals are used for the same components in accordance with the present invention.
[0024] Referring to FIG. 1 for a schematic view of a geographical information system, the geographical information system is provided for acquiring geographical information of a geographical object 11 , and the system comprises a geographical object message 111 and a mobile apparatus 12 , wherein the geographical object message 111 is provided by the geographical object 11 . The mobile apparatus 12 generates an inquiry command after the geographical object message 111 is received and identified. The geographical information corresponding to the inquiry command is searched from a database (not shown in the figure) of the mobile apparatus 12 based on the inquiry command, and the searched geographical information then is displayed on the mobile apparatus 12 .
[0025] The geographical object is generally a building or transportation, and the transportation can be a public transit such as a bus. The geographical information is generally information relative to the geographical object such as the floor distribution, building feature, building history, nearby traffic, current position of a bus, and bus route, etc. The geographical object message is an identification code or an image, and the identification code is usually a combination of character strings or a barcode, and the geographical object message is usually transmitted by an electronic label installed in the geographical object to the mobile apparatus through a radio frequency signal. The image of the geographical object, such as its appearance, is usually photographed by a built-in photography module of the mobile apparatus, and taken as the geographical object message. Further, the geographical object message of the identification code can be obtained from Internet or a short message, and provided for users to understand the related geographical information in advance. The mobile apparatus is generally a mobile electronic apparatus, and more specifically a personal digital assistant or a mobile communication apparatus. T he mobile apparatus further comprises a radio frequency reader for receiving a geographical object message transmitted by a radio frequency signal, or comprises a photography module for photographing an image of a geographical object and taking the image as the geographical object message provided by the geographical object, or comprises a communication module for obtaining the geographical object message from Internet or a short message through a wireless communication. In the meantime, the mobile apparatus further comprises an identification unit for identifying the geographical object message of the geographical object from outside to generate an inquiry command, and the identification unit is provided for decoding signals and comparing the decoded signals, or the identifying and comparing images. Besides, the mobile apparatus further comprises a navigation module for generating at least one guided route based on the geographical object message. The navigation module comprises an electronic component such as a global positioning system chip for providing a navigation function. The navigation function can be executed based on the geographical information such as longitude and latitude, POI name, the detail addresses, phone numbers and so on. The database is generally a storage module for storing information related to the geographical object, such as the floor distribution, building feature, building history, nearby traffic, current position of a bus, and bus route, etc or storing a lookup table of the geographical information and the inquiry command.
[0026] Referring to FIG. 2 for a schematic view of a geographical information system in accordance with a first preferred embodiment of the present invention, the geographical information system comprises an identification code 212 of a building 21 and a personal digital assistant (PDA) 22 , wherein the building 21 installs an electronic label 211 for transmitting the identification code 212 of the building 21 , and the personal digital assistant 22 generates an inquiry command after the identification code 212 is received and identified, and the geographical information 23 corresponding to the inquiry command is searched from a database built in the personal digital assistant 22 based on the inquiry command to display the searched geographical information 23 , such as the floor distribution, building feature, building history and nearby traffic, on the personal digital assistant 22 .
[0027] Referring to FIG. 3 for a schematic view of a geographical information system in accordance with a second preferred embodiment of the present invention, the geographical information system comprises an image 311 for the appearance of a bus 31 and a mobile communication apparatus 32 , wherein the image 311 of the appearance of the bus 31 is photographed by a built-in photography module of the mobile communication apparatus 32 . After the mobile communication apparatus 32 receives the image 311 of the appearance of the bus 31 and identifies the bus number of the bus 31 in the image 311 , an inquiry command is generated, and the geographical information 33 corresponding to the inquiry command is searched from a database built in the mobile communication apparatus 32 based on the inquiry command. The mobile communication apparatus 32 then displays the searched geographical information 33 such as the bus route, and the departure time of the bus.
[0028] Referring to FIG. 4 a schematic view of a geographical information system in accordance with a third preferred embodiment of the present invention, the geographical information system comprises an identification code 411 of a building 41 and a personal digital assistant 42 , wherein the identification code 411 of the building 41 is obtained by the personal digital assistant 42 from Internet 43 , and the related geographical information 421 searched from a database 422 of the personal digital assistant 42 allows users to understand the building 41 . According to the map information in the searched geographical information 421 , a navigation module 423 installed in the personal digital assistant 42 is utilized to generate at least one guided route through a global positioning system 44 so that a user then is guided to reach the designated building 41 .
[0029] Referring to FIG. 5 for a schematic view of another geographical information system of the present invention, the geographical information system is provided for acquiring geographical information 531 of a geographical object 51 , and the system comprises a geographical object message 511 , a mobile apparatus 52 and an information center 53 , wherein the geographical object message 511 is provided by the geographical object 51 . The mobile apparatus 52 generates an inquiry command 521 after the geographical object message 511 is received and identified, and a communication module 522 of the mobile apparatus sends out the inquiry command 521 . After receiving the inquiry command 521 , the information center 53 searches the geographical information 531 corresponding to the inquiry command 521 and sends the searched geographical information 531 to the mobile apparatus 52 for displaying.
[0030] The geographical object is generally a building or transportation, and the transportation can be a public transit such as a bus. The geographical information is generally information relative to the geographical object, such as the floor distribution, building feature, building history, nearby traffic, current position of a bus, and bus route, etc. The geographical object message is an identification code or an image, and the identification code is generally a combination of character strings or a barcode, and the geographical object message is generally sent by an electronic label installed in the geographical object to the mobile apparatus through a radio frequency signal. The image is generally the appearance of the geographical object photographed by a built-in photography module of the mobile apparatus, and taken as the geographical object message. Further, the geographical object message of the identification code can be obtained via Internet or a short message, so that users can understand the related geographical information in advance. The mobile apparatus is generally a mobile electronic apparatus, and more specifically a personal digital assistant or a mobile communication apparatus. The mobile apparatus further comprises a radio frequency reader for receiving the geographical object message transmitted by the radio frequency signal. Besides, the mobile apparatus also comprises a photography module for photographing the image of the geographical object and taking the image as the geographical object message provided by the geographical object. The mobile apparatus also comprises a communication module for obtaining the geographical object message from Internet or a short message via a wireless communication. Meanwhile, the mobile apparatus comprises an identification unit for identifying the geographical object message of the geographical object from outside to generate the inquiry command, and the identification unit can execute the decoding and comparison for signals or the identification and comparison for images. The mobile apparatus further comprises a navigation module for generating at least one guided route based on the geographical object message. The navigation module comprises an electronic component such as a global positioning system chip for providing a navigation function. The navigation function can be executed based on the geographical information such as longitude and latitude, POI name, the detail addresses, phone numbers and so on. The information center generally comprises a geographical information system (GIS) for providing geographical information corresponding to the inquiry command, and the geographical information system stores information related to the geographical object, such as the floor distribution, building feature, building history, nearby traffic, current position of a bus, and bus route, etc. or stores a lookup table of the geographical information and the inquiry command.
[0031] Referring to FIG. 6 for a schematic view of another geographical information system in accordance with a first preferred embodiment of the present invention, the geographical information system comprises an identification code 612 of a building 61 , a personal digital assistant 62 and an information center 63 , wherein the building 61 includes an electronic label 611 for sending the identification code 612 of the building 61 , and the personal digital assistant 62 generates an inquiry command 621 after the identification code 612 is received and identified, and a built-in communication module 622 of the personal digital assistant 62 sends out the inquiry command 621 based on the inquiry command 621 , and after the information center 63 receives the inquiry command 621 , the information center 63 searches the geographical information 631 corresponding to the inquiry command 621 and sends the searched geographical information 631 , including the floor distribution, building feature, building history, and nearby traffic, to the personal digital assistant 62 for displaying.
[0032] Referring to FIG. 7 for a schematic view of another geographical information system in accordance with a second preferred embodiment of the present invention, the geographical information system comprises the appearance of a bus 71 , a mobile communication apparatus 72 and an information center 73 , wherein an image 711 of the appearance of the bus 71 is photographed by a built-in photography module 722 of the mobile communication apparatus 72 , and the mobile communication apparatus 72 generates an inquiry command 721 after the image 711 of the appearance of the bus 71 is received and the bus number of the bus 71 of the image 711 is identified, and a communication module 723 of the mobile communication apparatus 72 sends out the inquiry command 721 to the information center 73 . The information center 73 searches the geographical information 731 corresponding to the inquiry command 721 after the inquiry command 721 is received, and sends the searched geographical information 731 , such as the route of the bus 71 and the departure time of the bus 71 , to the mobile communication apparatus 72 for displaying.
[0033] Referring to FIG. 8 for a schematic view of another geographical information system in accordance with a third preferred embodiment of the present invention, the geographical information system comprises an identification code 811 of a building 81 , a personal digital assistant 82 and an information center 83 , wherein the identification code 811 of the building 81 is obtained from the personal digital assistant 82 via Internet 84 , and a communication module 822 of the personal digital assistant 82 sends an inquiry command 821 to the information center 83 to obtain geographical information 831 , so that users can understand the related geographical information 831 . According to a map information of the geographical information 831 , a navigation module 823 installed in the personal digital assistant 82 generates at least one guided route by using a global positioning system 85 to guide users to reach a designated building 81 .
[0034] Referring to FIG. 9 for a schematic view of a mobile apparatus of the present invention, the mobile apparatus 90 comprises a device body 91 , a database 92 , a capture identification module 93 , a communication module 94 and a processor 95 , wherein the device body 91 provides basic operation functions for the mobile apparatus 90 . The database 92 , the capture identification module 93 , the communication module 94 and the processor 95 are installed in the device body 91 . The database 92 stores geographical information 921 of at least one geographical object, and the capture identification module 93 obtains a geographical object message 931 of the geographical object from outside, and identifies the geographical object message 931 to generate an inquiry command 932 . The communication module 94 is provided for sending out the inquiry command 932 in order to obtain geographical information from outside. After the processor 95 receives and processes the inquiry command 932 , the processor 95 transmits the inquiry command 932 to the database 92 to search the geographical information 921 corresponding to the inquiry command 932 , or transmits the inquiry command 932 to the communication module 94 .
[0035] The mobile apparatus is generally a mobile electronic apparatus, and more specifically a personal digital assistant or a mobile communication apparatus. The capture identification module further comprises a radio frequency reader for obtaining a geographical object message of a geographical object transmitted by a radio frequency signal from outside, or comprises a photography module for photographing an image of the geographical object and taking the image as the geographical object message provided by the geographical object, and further comprises an identification unit for generating an inquiry command after the obtained geographical object message of the geographical object is identified. The identification unit can decode and compare signals or identify and compare images. The database is generally a storage module for storing information relative to the geographical object, such as the floor distribution, building feature, building history, nearby traffic, current position of a bus, and bus route, etc. or stores a lookup table of the geographical information and the inquiry command. The geographical object is generally a building or transportation, and the transportation can be a public transit such as a bus. The geographical information is generally information relative to the geographical object, such as the floor distribution, building feature, building history, nearby traffic, current position of a bus, and bus route, etc. The geographical object message is an identification code or an image, and the identification code is generally a combination of character strings or a barcode, etc., and the geographical object message generally includes an electronic label installed in the geographical object and is sent to the mobile apparatus by a radio frequency signal. The image is generally the appearance of the geographical object photographed by a built-in photography module of the mobile apparatus and taken as the geographical object message provided by the geographical object. Further, the geographical object message of the identification code can be obtained via Internet or a short message, so that users can understand the related geographical information. In the meantime, the mobile apparatus further comprises a navigation module for generating at least one guided route based on the geographical object message. The navigation module comprises an electronic component such as a global positioning system chip for providing a navigation function. The navigation function can be executed based on the geographical information such as longitude and latitude, POI name, the detail addresses, phone numbers and so on.
[0036] Referring to FIG. 10 for a flow chart of a method of acquiring geographical information of the present invention, the method is applied in a mobile apparatus for displaying geographical information, and comprises the steps of:
[0037] Step Sa 1 : obtaining a geographical object message of a geographical object from outside;
[0038] Step Sa 2 : generating an inquiry command after the geographical object message is identified;
[0039] Step Sa 3 : searching geographical information corresponding to the inquiry command from a database, or searching geographical information corresponding to the inquiry command from an information center based on the inquiry command; and
[0040] Step Sa 4 : displaying the geographical information on the mobile apparatus.
[0041] The mobile apparatus is generally a mobile electronic apparatus, and more specifically a personal digital assistant or a mobile communication apparatus, and the geographical object is generally a building or a transportation, and the transportation is a public transit such as a bus. The geographical information is generally information relative to the geographical object, such as the floor distribution, building feature, building history, nearby traffic, current position of a bus, and bus route, etc. The geographical object message can be an identification code or an image, and the geographical object message is obtained from Internet, a short message or a geographical object. The identification code is generally a combination of character strings or a barcode, and the geographical object message is generally transmitted by an electronic label installed in the geographical object to the mobile apparatus through a radio frequency signal. The image, such as the appearance of the geographical object, is generally photographed by a built-in photography module of the mobile apparatus, and taken as a geographical object message provided by the geographical object. The database is generally a storage module for storing information relative to the geographical object, such as the floor distribution, building feature, building history, nearby traffic, current position of a bus, and bus route, etc., or storing a lookup table of the geographical information and the inquiry command. The information center generally includes a geographical information system for providing geographical information corresponding to the inquiry command, such as the floor distribution, building feature, building history, nearby traffic, current position of a bus, and bus route, etc, and also storing a lookup table of the geographical information and the inquiry command. In the meantime, the mobile apparatus further comprises a navigation module for generating at least one guided route based on the geographical object message, and the navigation module comprises an electronic component such as a global positioning system chip for providing a navigation function. The navigation function can be executed based on the geographical information such as longitude and latitude, POI name, the detail addresses, phone numbers and so on.
[0042] Referring to FIG. 11 for a flow chart of a method of acquiring geographical information in accordance with a preferred embodiment of the present invention, the method comprises the steps of:
[0043] Step Sb 1 : sending out an inquiry signal from a radio frequency reader of a personal digital assistant;
[0044] Step Sb 2 : receiving an identification code sent from an electronic label of a building through a radio frequency signal;
[0045] Step Sb 3 : generating an inquiry command after the radio frequency reader receives and identifies the identification code;
[0046] Step Sb 4 : searching the geographical information corresponding to the inquiry command from a database based on the inquiry command or sending the inquiry command to the information center by the communication module to search the geographical information corresponding to the inquiry command; and
[0047] Step Sb 5 : displaying the geographical information, such as the floor distribution, building feature, building history and nearby traffic, on the personal digital assistant.
[0048] While the invention has been described by way of example and in terms of preferred embodiments, it is to be understood that the invention is not limited thereto. To the contrary, it is intended to cover various modifications and similar arrangements and procedures, and the scope of the appended claims therefore should be accorded the broadest interpretation so as to encompass all such modifications and similar arrangements and procedures.
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A mobile apparatus, a geographical information system and a method of acquiring geographical information are disclosed. The geographical information system is used for acquiring geographical information of a geographical object. The system at least includes a geographical object message and a mobile apparatus. The geographical object message is provided by the geographical object. The geographical object is generally an identification code or an image. The mobile apparatus is used for receiving the geographical object message, and generating an inquiry command after identifying the geographical object. Geographical information corresponding to the inquiry command is searched from a database of the mobile apparatus based on the inquiry command. The searched geography information is displayed on the mobile apparatus. The invention provides a direct viewing of geographic information for users to improve the degree of freedom of a trip and effectively manage personal time.
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This application is a divisional of Ser. No. 08/870,289 filed Jun. 6, 1997, now U.S. Pat. No. 5,996,879.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a pressure welding apparatus and a method for pressure-welding an electric wire to a pressure welding terminal in a double-sided solderless connector quickly and surely according to various wire-diameters.
2. Description of the Prior Art
FIG. 7 shows a conventional pressure welding means, wherein a solderless connector 46 is fixed on a base table 65 and an electric wire 67 is pressure-welded to a pressure welding terminal 36 in the solderless connector 46 by a pressure welding blade 66. The solderless connector 46 is a double-sided solderless connector having the pressure welding terminals 36 on both the upper and lower sides thereof, and after the electric wires 67 have been pressure-welded to all the pressure welding terminals 36 in upper receiving chambers 68, the electric wires 67 are pressure-welded likewise to the lower pressure welding terminals 36 after turning one side of the connector 46 to the other side. The electric wire 67 is relatively easily led to the terminal 36 due to a partition 47 between adjoining terminals.
However, in case of the pressure welding means shown in FIG. 7, it has been a bothersome work to change the pressure welding blade 66 at each time of working according to kind (diameter) of electric wire 67. And, there has been a problem such that the pressure welding has resulted in imperfect connection caused by insufficient stroke of the pressure welding blade 66 due to a downward deflection of a bottom plate 38 of the solderless connector 46 by pressure.
Further, FIGS. 8 and 9 show an example of the conventional pressure welding of an electric wire 70 to a solderless connector 69 with a wire guide 68, wherein a pair of horizontal wire guides 68 are arranged on a partition 71 of the connector 69 and the electric wire 70 inserted into the pair of wire guides 68 is pressure-welded as being guided along the wire guides 68 to a pressure welding terminal 73 by a pressure welding blade 72.
However, there has been a problem that the structure shown in FIGS. 8 and 9 is not applicable to a solderless connector (not shown) having no partition 71 between the pressure welding terminals 73, wherein the electric wire 70 should have been guided by the partition 71 from the lower end of the wire guides 68 to the pressure welding terminal 73.
SUMMARY OF THE INVENTION
An object of the present invention is to provide a pressure welding means which eliminates the aforementioned bothersome work of changing a pressure welding blade according to many kinds of electric wires and ensures perfect pressure welding of a double-sided solderless connector by preventing a deflection thereof caused by a given pressure and further ensures to guide an electric wire in case of a solderless connector lacking a partition between pressure welding terminals.
To achieve the above objective, the present invention adopts a pressure welding apparatus wherein a plurality of applicators having various wire pressure welding blades and connector support blades with a mechanism movable in up and down directions are arranged radially and rotatively around a rotary shaft enabling the operator to select said wire pressure welding blade and said connector support blade through rotary operation of said applicator. It is possible to arrange a plurality of said rotatable applicators symmetrically with respect to a double-sided solderless connector.
Further, the present invention provides a pressure welding method wherein a wire pressure welding blade and a connector support blade with a mechanism movable in up and down directions are arranged opposite to each other on both sides of a double-sided solderless connector and an electric wire is pressure-welded to one side of said double-sided solderless connector by said wire pressure welding blade, while the other side of said double-sided solderless connector is supported by said connector support blade. Still further, the present invention provides a pressure welding method, wherein a pair of wire guides are arranged on both sides of a wire pressure welding blade and an electric wire is pressure-welded along said wire guides to a pressure welding terminal in a solderless connector by said wire pressure welding blade, that said wire guides are vertically movable and, at the time of pressure welding, a pair of wire guides are closely located on both sides of said pressure welding terminal on a bottom wall of said solderless connector, also making the ends thereof contact with said bottom wall.
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 partially cross-sectional side view of a pressure welding apparatus according to an embodiment of the present invention;
FIG. 2 is a front view of the pressure welding apparatus of FIG. 1;
FIG. 3 is a plan view showing a rotary type applicator of the pressure welding apparatus of FIG. 1;
FIG. 4 is a front view showing a pressure welding method with a support blade;
FIG. 5 is a front view showing a state of the pressure welding of FIG. 4;
FIGS. 6A,6B,6C and 6D are front views showing a pressure welding method with wire guides;
FIG. 7 is an exploded perspective view showing a conventional pressure welding method;
FIG. 8 is a front view showing a pressure welding method with a conventional wire guide; and
FIG. 9 is a partially cross-sectional side view of the pressure welding method of FIG. 8.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
FIGS. 1 through 3 show an embodiment of a pressure welding apparatus according to the present invention.
The first feature of the pressure welding apparatus 1 is that a plurality of applicators (in this embodiment, six(6) per one side) 4 with various wire pressure welding blades (hereinafter referred to as "pressure welding blade") 2 and connector support blades (hereinafter referred to as "support blade") 3 are arranged radially around a rotary shaft 5 for enabling to suitably select an applicator 4 according to a wire-diameter by rotary operation of the shaft 5 with use of a servo-motor 6 and a timing belt 7.
According to the present embodiment, pressure welders 8a and 8b are arranged symmetrically in a vertical direction. A vertically symmetric structure has been disclosed in Japanese Patent Publication No. Heisei 8-124967. As shown in FIG. 1, the shaft 5 is set vertically and is supported by bearings 9 at both an intermediate portion and the base-end and has a small pulley 10 fixed on the other shaftend. The small pulley 10 is connected, with said timing belt 7, to a large pulley 11 of the servo-motor 6. The large pulley 11 is fixed to an output shaft 13 of a reduction gear 12 of the servo-motor 6. The large pulley 11 has a projection 14 for indicating a starting point, and a micro-photosensor 15 for detecting said projection 14 is provided on an apparatus frame 16. Setting of the starting point of rotating position of the applicator 4 is performed by using the sensor 15.
A slide guide 17 is fixed on said shaft 5, and a slider 19 having the pressure welding blade 2 or the support blade 3 is engaged movably in a vertical direction with the slide guide 17 by means of a coil spring 18.
As shown in FIG. 2, the support blade 3 of the lower pressure welder 8b is located opposite to the pressure welding blade 2 of the upper pressure welder 8a, or the pressure welding blade (2) of the lower pressure welder 8b can be located opposite to the support blade (3) of the upper pressure welder 8a. This point is the second feature of the pressure welding apparatus 1. A difference between the pressure welding blade 2 and the support blade 3 is an existence of a bent surface at the end as shown in FIGS. 4 and 5. It is acceptable on the upper pressure welder 8a to attach the pressure welding blade 2 to one applicator 4 (shown in FIG. 1) and to attach the support blade 3 to another applicator 4. For example, three kinds of pressure welding blades 2 and three kinds of support blades 3 can be arranged. This is the same for the lower pressure welder 8b. This enables to select any of the pressure welding blade 2 and the support blade 3 according to a wire-diameter by rotating the applicator 4.
Referring to FIGS. 1 and 2, the pressure welding blade 2 or the support blade 3 is fixed to respective slider 19, and a shank portion 21 fixed on the top of the slider 19 is engaged with a claw 23 of a primary slider 22. The primary slider 22 is driven up and down by a motor 25 located on the top of the apparatus by means of a crank mechanism 24 including a flywheel 26, a connecting pin 27 and a connecting rod 28. Said slider 19 is located at the top dead point by being pushed upward by the coil spring 18. The slider 19 descends by being pushed by the primary slider 22.
A connector holding beam 30 is placed between the upper and lower pressure welders 8a and 8b, and a plurality of solderless connectors 32 are arranged in parallel on said holding beam 30. This structure has been also disclosed in Japanese Patent Publication No. Heisei 8-124967.
FIGS. 4 and 5 show a state (method) of pressure welding connection of an electric wire 33 by the pressure welding blade 2 and the support blade 3 to a double-sided solderless connector 32 held by the holding beam 30. The bent surface 20 corresponding to a wire-diameter is formed at the end of the pressure welding blade 2 and a horizontal plane 34 is formed at the end of the support blade 3.
Upon performing the pressure welding, as shown in FIG. 5 the lower support blade 3 enters into a receiving chamber 39 of the solderless connector 32 and makes contact with a bottom of connector to support the solderless connector 32 without a deflection. Next or at the same time, the upper pressure welding blade 2 pressure-welds the electric wire 33 to a pressure welding terminal 35 in the solderless connector 32. The pressure welding of the electric wire 33 is surely performed without deficiency of pressing since the solderless connector 32 does not bend downward at wire's pressure welding because of supporting the solderless connector 32 by the support blade 3 from below.
The support blade 3 could be of platelike or columnlike, and for example it supports a portion between the front and rear pressure welding portions 36a of a pressure welding terminal 36 or directly supports a bottom wall (a partition) 38 of a connector housing 37 of FIG. 7. Driving of the support blade 3 and that of the pressure welding blade 2 are done by vertical movement of the slider 19 shown in FIG. 2. It is effective to make the vertical movement of the support blade 3 and the pressure welding blade 2 simultaneously for eliminating a time loss. After completion of the pressure welding of electric wires to the upper receiving chambers 39 of the solderless connector 32 shown in FIGS. 4 and 5, the pressure welding of electric wires to the lower receiving chambers 39 is performed following a setting of the support blade 3 on the upper side and the pressure welding blade 2 on the lower side by rotating the upper and lower applicators 4 shown in FIG. 1.
As shown in FIGS. 2 and 6, a pair of wire guides 40 are arranged movably in a vertical direction on both sides of the pressure welding blade 2. Said wire guides 40 are pushed toward the connector by a coil spring 41 as shown in FIG. 2 and are supported movably and vertically in the slider 19 by means of the coil spring 41. The wire guides 40 have a vertically straight sheet portion 40a with almost the same width as the pressure welding blade 2 as shown in FIGS. 1, 6A and 6B. Said wire guides 40 have been disclosed in Japanese Patent Publication No. Heisei 8-124967, but the present embodiment is characterized by a pressure welding method shown in FIG. 6B, wherein said wire guides 40 also function as a partition between each pressure welding terminal 43 in the solderless connector 42. This is the third feature of the present invention.
That is, as shown in FIG. 6A, firstly the electric wire 33 is located over the pressure welding terminal 43, and the pair of wire guides 40 are located on both sides of the electric wire 33, and the pressure welding blade 2 is located between the pair of wire guides 40. Secondly, as shown in FIG. 6B, the electric wire 33, the wire guides 40 and the pressure welding blade 2 are descended as a unit according to a descent of the slider 19 shown in FIG. 2, and the wire guides 40 are inserted into spaces between the adjacent pressure welding terminals 43, and then wire guide ends 40b make contact with a housing bottom wall 44 of the solderless connector 42. The pair of wire guides 40 are closely located on both sides of the pressure welding terminal 43. A vertically long guide plane 40d is formed at the inside of the sheet portion 40a of the wire guide 40, and the long sheet portion 40a guides the electrical wire 33 to the pressure welding terminal 43 even if housing side walls 45 of the solderless connector 42 are high.
Next, the pressure welding blade 2 is descended as shown in FIG. 6C, compressing the coil spring 41 shown in FIG. 2, and pressure-welds the electric wire 33 to the pressure welding terminal 43 as shown in FIG. 6D. The electric wire 33 is surely guided to the pressure welding terminal 43 since the pair of wire guides 40 also function as partitions as shown in FIGS. 6C and 6D in case a partition 47 in a solderless connector 46 shown in FIG. 7 is not provided.
An example wherein the wire guide 40 also functions as a connector support is shown in Japanese Patent Publication No. Heisei 8-124967.
Referring to FIG. 1, wire chuck portions 48 are located facing each other in front of the pressure welding blade 2, and the end of the electric wire 33 held by a pair of chuck claws 49 is pressure-welded to the solderless connector 32 by the pressure welding blade 2. In FIG. 1, the motor 25 is driven by turning on a wire detecting switch 50. The wire chuck portion 48 is descended as a unit with the primary slider 22 by a bump of a cylinder head 53 of a chuck cylinder 52 against a bumping projection 51 of the primary slider 22. A distance L between the bumping projection 51 and the cylinder head 53 equals to a distance between the electric wire 33 and the pressure welding blade 2. The wire chuck portion 48 ascends as a unit with the primary slider 22 by being pushed by the coil spring 54.
Said chuck portion 48 consists of the chuck cylinder 52 for opening or closing the pair of chuck claws 49, a spring holder 55 integrated with the cylinder head 53, a vertical guide 56 for vertically guiding the sliding of the chuck cylinder 52, a chuck stay 57 holding, said vertical guide 56 and standing upward, and the coil spring 54, which is flexibly set between a stay lower portion 58 and the spring holder 55, for pushing the chuck cylinder 52 up to the top dead point.
Said chuck stay 57 is fixed to a horizontal slider 59, and said horizontal slider 59 can horizontally move along two(2) horizontal guide bars 60 as shown in FIG. 2. A pair, right and left, of said wire chuck portions 48 are provided, and each chuck stay 57 is integrally fixed to the horizontal slider 59.
In case one chuck portion 48 is located at the center of the guide bar 60, that is, in front of the pressure welding blade 2, the other chuck portion 48 is located at the end of the guide bar 60 for enabling to receive the electric wire 33 from a worker. A structure of the chuck has been disclosed in Japanese Patent Publication No. Heisei 8-124967.
According to the present invention, as previously described, selection of the pressure welding blade and the support blade can be done by rotating the applicator, which increases productivity by eliminating time consuming conventionally required for changing the pressure welding blade or the support blade according to a kind (diameter) of electric wire. And, a speedy changeover of the pressure welding blade and the support blade arranged up and down can be done for dealing with the double-sided solderless connector. Also, sure pressure welding can be performed by preventing a deflection of the solderless connector causing from a given pressure. Further, sure guiding and sure pressure welding of an electric wire can be performed for a solderless connector having no partition between pressure welding terminals.
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Electric wires of a double-sided solderless connector are pressure-welded. The method of the pressure-welding includes the steps of: locating a pressure welding blade and support blade on both sides of a double-sided solderless connector, in a face to face relationship, so as to be movable in vertical direction; supporting one side of said double-sided solderless connector with said support blade; and pressure-welding respective electric wires to terminals at the other side of said double-sided solderless connector with said pressure welding blade.
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BACKGROUND OF THE INVENTION
[0001] The present invention relates to a method for economically converting salty or brackish water to fresh water by utilizing the existing water pressures that are available in operations such as the injection of water for oil recovery.
[0002] There is an increasing need for fresh water in various parts of the world, and a number of these areas are near operations where large amounts of water are pumped at pressures that can be utilized to purify water by reverse osmosis. Although reverse osmosis is widely used to remove dissolved solids from various impure waters, a few inherit problems limit its overall effectiveness. Chief among these are:
[0003] 1. The energy cost for pumping the raw feedwater up to pressures sufficient for reverse osmosis.
[0004] 2. The disposal of the reject water, whose saltiness is much increased over that of the original feedwater.
[0005] 3. Membrane fouling, both from entrained solids and from a buildup of the rejected ions on the membrane surface.
[0006] Current reverse osmosis practices address these difficulties in various ways, but it is believed that none have solved all of the problems as effectively and economically as is proposed by the present invention.
[0007] Disposal of the reject water for reverse osmosis remains a problem, especially in areas where laws restrict its discharge into streams, underground, or on the surface. To overcome the problem of the discharge of large volumes of salty water, U.S. Pat, No. 6,241,892, T. M. Whitworth, provides a process wherein the rejected material consists primarily of the solid salts, but even these small volumes must be disposed of or utilized in some way.
[0008] Membrane fouling is always a limitation in reverse osmosis and is often handled by simply halting the operation and using a procedure such as flushing to clean the surface of the membranes, but this interruption reduces the overall conversion efficiency of the feedwater to fresh water.
[0009] Therefore, there have been many attempts to improve on the membrane flushing/cleaning systems, or to pre-treat the feedwater so flushing is not needed as often.
[0010] For example, U.S. Pat. No. 6,334,955, T. Kawashima and T. Kawada, requires a timer that periodically opens and closes a special flushing valve to clean the reverse osmosis membranes during fresh water generation work, when interrupted, or when restarting after interruption, but the device adds to the complexity and cost of the system.
[0011] A number of physical and chemical methods have been studied to improve the quality of various feedwaters prior to contact with the reverse osmosis membranes. By way of example:
[0012] U.S. Pat. No. 6,395,181, S. B. Mullerheim, uses physical separation methods to remove solids and floatable materials;
[0013] U.S. Pat. No. 6,365,051, M. S. Bader, adds an organic solvent to precipitate the dissolved salts;
[0014] U.S. Pat. No. 6,183,646, E. E. Williams et al., treats the feedwater with agents designed to prevent biofouling;
[0015] U.S. Pat. No. 5,925,255, D. Mukhopadhyay, uses special treatments at high pH to remove hardness, etc. from feedwater prior to reverse osmosis;
[0016] U.S. Pat. No. 5,250,185, F. T. Tao, et al., softens the feedwater and raises the pH prior to reverse osmosis to reject more of the boron.
[0017] Thus, although there have been many efforts to try to solve certain facets of the aforementioned reverse osmosis problems, all known methods would add to the cost of the fresh water produced, and none of the improvements can solve all of the problems at the same time.
[0018] It is therefore an object of the present invention to utilize the existing pressures and high-flow velocities, which are available in situations such as waterflood injection water systems, to produce fresh water by reverse osmosis at a very low cost, with a minimum of membrane fouling, and with no wastewater disposal problems.
BRIEF DESCRIPTION OF THE DRAWINGS
[0019] This object, and other objects and advantages of the present invention, will appear more clearly from the following specification in conjunction with the accompanying schematic drawings, in which:
[0020] [0020]FIG. 1 illustrates a first embodiment of a system for carrying out the method of the present invention;
[0021] [0021]FIG. 2 shows a second embodiment for carrying out the inventive method; and
[0022] [0022]FIG. 3 shows a modified embodiment of the system of FIG. 2.
SUMMARY OF THE INVENTION
[0023] The method of the present invention includes the steps of disposing at least one reverse osmosis unit in a feedwater supply conduit, conveying through the supply conduit and the reverse osmosis unit feedwater at a pressure that exceeds the osmotic pressure for solids dissolved in the feedwater, and withdrawing from the reverse osmosis unit a first stream of fresh water as permeate, and a second stream of effluent, wherein the effluent is returned to, or continues to flow in, the supply conduit downstream of the reverse osmosis unit.
[0024] The present invention has a number of advantages. First of all, no additional power is required for the reverse osmosis. Furthermore, the membranes of the reverse osmosis unit or units are kept cleaner, and therefore the transport of fresh water through the membranes is enhanced by the high velocity of the feedwater as it flows past the membrane surfaces. In addition, there are no reject water disposal problems, since the reject water or effluent, which is still pressurized, is utilized for a further purpose.
[0025] Further specific features of the present invention will be described in detail subsequently.
DESCRIPTION OF PREFERRED EMBODIMENTS
[0026] Referring now to the drawings in detail, one of the preferred embodiments is illustrated in FIG. 1, which shows a reverse osmosis unit 1 , which is installed in a pipeline 2 that is connected to a water injection well in an oilfield (not shown). The supply water 3 (or feedwater) comes from the high-powered pumps of, for example, the oilfield injection water system, and is generally at a pressure that is sufficient for reverse osmosis; the water is usually filtered before it is sent to the pipeline distribution system. In operation, the valves 4 are normally open and the valves 5 are largely closed so that the bulk of the high-pressure feedwater flows around the semi-permeable membranes 6 at high velocity and flows on to the injection well or wells. If the pressure is high enough to exceed the osmotic pressure of the brackish or salty feedwater (for example 350 psi for the salt concentration of seawater) some fresh water (or permeate) 7 is forced through the membranes 6 and is collected in the symbolic container 8 as high quality fresh water, normally at or near atmospheric pressure, while the salt is rejected and is carried on towards the injection well in the reject water 9 . Thus there are no saltwater disposal problems since 100% of the reject water 9 is injected into oil reservoirs to displace oil. Since the volume of water flowing past the membranes is much greater than in most reverse osmosis systems, the increase in the salt concentration of the reject water is more modest. This increased saltiness is not a problem in the injection water, and it may even be a distinct advantage for oil recovery in those reservoirs that contain some types of clays that are prone to swelling with fresher water. This complete absence of any saltwater disposal problem is a key feature of the present invention.
[0027] In the embodiment illustrated in FIG. 1, one or more of the valves 5 are disposed in a by-pass loop, and are fully opened, partially opened, or closed as needed for installation purposes, servicing, adjustment of flow rate, etc.
[0028] The composition of the feedwater 3 (as well as the pressure at which it is supplied) covers a very wide range. About one half of all oil produced in the USA is aided by waterflooding and the EPA estimates that 21 billion barrels are injected annually for this purpose. The oil producers will utilize any water that is available and the injection water can range from any available fresh water or brackish water to the saltier underground waters often located in or near oil reservoirs. In mature waterfloods, salty formation water may be produced along with the oil and then reinjected.
[0029] Several types of water that could be encountered in oilfield waterfloods are listed in Table 1, along with the approximate natural osmotic pressure and the pressure needed for a good flow rate across the reverse osmosis membranes. Since the pressures used in waterfloods range from less than 100 to a few thousand pounds per square inch (psi) it can be seen in Table 1 that the present invention encompasses most of the waters that are now being injected for oil recovery. Therefore, no limits are placed on the pressures at which the present invention is effective as long as the reverse osmosis membranes can withstand the pressure. Since commercial reverse osmosis units are readily available for all types of brackish waters, and higher pressure units are available for the saltiest of seawaters, the present invention can be utilized immediately for all feedwaters except possibly the most concentrated brines. However, better membranes and higher pressure units are being developed and are therefore not excluded from the present invention.
[0030] The reverse osmosis unit 1 shown in FIG. 1 is just a schematic to show the direct application of the present invention to a water injection system in an oilfield. The reverse osmosis membrane unit 1 is simply flanged into the injection line to make as few changes as possible. Commercial membrane units (or modules) come in different lengths and diameters with end plates that can be adapted to standard oilfield piping systems.
[0031] The sketch in FIG. 1 is not intended to show the actual arrangement of the membranes within the membrane unit 1 . Either of the commercial spiral wound or hollow fiber membranes can be utilized in the present invention. A tubular membrane configuration may also work well because higher velocities of feedwater may be possible. The choice depends on the conditions: spiral wound membranes are available for the lower dissolved solids in some brackish water applications; hollow fiber configurations are very effective for higher salt concentrations (similar to seawater) because they can withstand higher pressures, have a higher surface area to volume ratio, and cause less pressure drop in the feedwater stream. To further enhance the benefits of the present invention, in some applications membrane modules are utilized that are designed to allow more space around the hollow fiber bundles to accommodate the fast-flowing feedwater. This luxury is possible since the contemplated oilfield application differs markedly from the usual reverse osmosis facilities because here the primary product is actually the saltwater effluent, all of which is injected to produce oil at a profit. The low-cost fresh water is only a byproduct but it can be a valuable one in areas where fresh water is needed. Therefore, full advantage can be taken of the much larger volumes of supply water that pass the membranes, and the usual conversion efficiency question (i.e., fresh water produced per unit of supply water) will not be a concern.
[0032] The large volume of feedwater that flows at high velocity past the membranes in the present invention increases the efficiency in at least two ways. First, as the water permeates the membrane under the applied pressure, a higher salt concentration is left behind at the surface of the membranes. This build up of a Concentrated Polarization Layer (or CPL) retards the flow of pure water through the membrane. Normally these excess dissolved salts are removed by slow diffusion away from the membrane surface until they reach the flowing feedwater stream. However, the large volume and high velocity of the feedwater of the inventive system helps to sweep away this CPL continuously, and much more effectively than in those systems that must be concerned with reducing the volume of wastewater discharged. Secondly, the high velocity and more turbulent flow of the feedwater in the membrane modules keeps the membrane surface much clearer of any entrained solids or other foreign material that can clog the membranes. Thus the membranes of the present invention need less frequent cleaning.
[0033] [0033]FIG. 1 illustrates a simple membrane module that allows high flow rates when added to an existing pipeline such as in an oilfield waterflood. In large scale reverse osmosis systems additional modules are often added in parallel and/or in series to increase the overall production of the fresh water, and these options are included in the present invention.
[0034] In another preferred embodiment shown in FIG. 2, four modules or units 10 are shown that are installed on a high-pressure water line 11 as illustrated. In this embodiment the feedwater 12 can be any water source that meets the criteria of the present invention, that is, it is being pumped for some use at a pressure that exceeds the osmotic pressure for the dissolved solids in the supply stream. In addition to water on its way to injection wells in oilfields, the feedwater 12 includes various applications such as cooling water in power plants where large volumes are circulated, and the small increase in salt concentration is not a problem. The assembly in FIG. 2 can be installed wherever it is convenient and where fresh water is desired. For example, in a pump house where the water is pumped to the pressure needed for the waterflood or other use, on offshore platforms where seawater is injected in waterfloods and where freshwater is always needed for various purposes, etc.
[0035] In operation, the pressure control valve or regulator 13 is partially closed or adjusted to ensure that a sufficient portion of feedwater 12 flows through the modules 10 and past the membranes 14 at high velocities to ensure that the aforementioned membrane cleaning advantages occur. Commercial “off the shelf” membrane modules may be used for the modules 10 as long as they are designed for the pressures of the system. To ensure the high velocity of the feedwater 12 past the membranes, it is advantageous if the feedwater distribution piping 15 , valves and fittings (not shown), along with the reject water piping system 16 , are of a larger diameter than those usually used in reverse osmosis systems that do not utilize the large volumes of the present invention.
[0036] In the embodiment shown in FIG. 2, large volumes of fresh water permeate 17 are produced efficiently for very low cost since the feedwater is pumped to the required pressure for other purposes. The large volume of reject water 16 rejoins the flowing feedwater 12 at 18 as shown in FIG. 2. The combined working water stream 19 flows on to its point of utilization, such as the aforementioned injection wells, cooling water, etc.
[0037] Another preferred embodiment of the invention is illustrated in FIG. 3 for those situations where the high-velocity feedwater 20 is not pressurized enough to exceed the osmotic pressure of the dissolved solids in the feedwater. In these cases a small booster pump 21 is installed to increase the pressure of the feedwater before it enters the membrane modules 10 . In general, the reverse osmosis modules array in FIG. 3 functions the same as in FIG. 2, and thus the same reference numbers have been used as in FIG. 2. The feedwater 20 splits into two streams and the adjustable pressure control valve 13 is not necessarily closed as far in this embodiment because the booster pump 21 helps to send a portion of the feedwater 20 on through the modules 10 as shown. To ensure that the osmotic pressure of the feedwater is exceeded, a pressure-control and relief valve 23 is installed on the reject pipeline 16 before it rejoins the main pipeline 22 at 18 . This valve drops the higher-pressure water 16 to a value close to that of the main feedwater 20 . The booster pump 21 , and the control valves 13 and 23 , are all adjusted in concert so that the pressure of the reject water will not be too dissimilar from the pressure in the main pipeline 22 . There is no danger of backflow through the relief valve 23 because of the higher pressure that is maintained on the feedwater side of the membrane in the array and at all points between the booster pump 21 and the relief-control valve 23 . This pressure is normally at least twice the osmotic pressure for the dissolved solids in the feedwater (see Table 1). Again, as in the other embodiments of the present invention, a high-flow rate of the feedwater past the membranes 14 is maintained so that the membranes are less subject to fouling and the reverse osmosis transport of fresh water through the membrane is enhanced. Also, the reject water becomes part of the pressurized water system at 18 , and the combined water 24 is fully utilized so there is no disposal problem. Although some power is required for the booster pump the amount is always somewhat less than for those reverse osmosis systems that do not use already-pressurized water as in the present invention. It should be noted that although the modules 10 are illustrated as being disposed in a parallel relationship, they could also be disposed in series, or partly in parallel and partly in series.
[0038] The present invention is, of course, in no way restricted to the specific disclosure of the specification and drawings, but also encompasses any modifications within the scope of the appended claims.
TABLE 1 Pressures Required for Reverse Osmosis of Various Types of Predominantly Salty Feedwaters Pressure Desired for Good Flow Total Dissolved Natural Osmotic Rates Across Solids mg/l Pressure Reverse Osmosis (parts/million) (psi) Membranes Water Type (ppm) (˜0.01/ppm) (psi) Potable Waters W.H.O. 500 5 10-20 Specifications EPA Standards 1,000 10 20-30 Substandard 1,000-7,000* 10-70 20-140 drinking waters Brackish Water 1,500-5,000 15 30-50 50 100-150 Seawater 35,000 350 800-1,200 Concentrated 200,000-300,000 2,000-3,000 4,000-5,000 brines 6,000-7,000
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A method is provided for converting feedwater to fresh water utilizing existing water pressures and high flow rates. At least one reverse osmosis unit is disposed in a feedwater supply conduit. Feedwater is conveyed through the supply conduit and the reverse osmosis unit at a pressure that exceeds the osmotic pressure for solids dissolved in the feedwater. A first stream of fresh water is withdrawn from the reverse osmosis unit as permeate, and a second stream is withdrawn therefrom as effluent. The effluent is returned to, or continues to flow in, the supply conduit downstream of the reverse osmosis unit.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention is directed to a method and apparatus for detecting a state of imminent cardiac arrhythmia, wherein detection of the state of imminent arrhythmia is made by using nerve signals from the autonomic nerves innervating the heart, and for administering appropriate anti-arrhythmia therapy upon detection of the state of imminent cardiac arrhythmia.
2. Description of the Prior Art
In the control of a device for heart therapy, such as a pacemaker, it is known to use signals providing a measure of the body's work load, in addition to utilization of the parameters in the ECG signal generated by the heart itself. These signals can be obtained when one or more load-related physiological variables, such as pH, oxygen saturation in blood etc., is/are detected with sensors. In more advanced devices for heart therapy, in which the device is able to provide many kinds of treatment depending on the condition of the heart, control of the device can also be exercised by utilization of other signals indicative of whether such conditions are either present, or are in the process of becoming established (incipient). Signals of these kinds can be related to hemodynamic conditions, e.g. blood pressure in the right ventricle. A sudden drop in pressure, combined with a very fast heart rate, could be indicative of, e.g., fibrillation in the heart.
In particular, control can be exercised through signals containing information related to the autonomic nervous system (ANS). In addition to being indicative of established heart conditions, these signals can also improve the possibility of detecting impending changes in the heart's condition so that prophylactic treatment can be started, e.g. to prevent the development of tachyarrhythmias, fibrillation in particular.
The autonomic nervous system innervates the heart by means of two sub-systems, the sympathetic nervous system and the parasympathetic nervous system respectively. The sub-systems will henceforth usually be referred to simply as the "sympathetic nerve" and "vagus nerve", unless otherwise specified. Increased signal activity in the sympathetic nerve increases heart activity, and increased signal activity in the vagus nerve reduces heart activity. Both systems normally balance each other when the body is at rest.
European Application 0 532 144 discloses a system for ANS control of a device for heart therapy. The device can also include a nerve stimulator, in addition to a conventional device for electrical heart therapy. In order to achieve a control signal related to the ANS, activity is detected in the sympathetic nerve by measurement of the regional, effective rise in impedance in the right ventricle. After the measurement signal is processed, the rise in impedance can be used as the control signal for the therapy device. Control could also be exercised through collaboration with one or more of the signals indicative of the body's work load, as noted above. In the device according to European Application 0 532 144, the activity of the sympathetic nerve or the activity of the nerve signal is indirectly sensed by measurement of this activity in the form of its effect on the heart via some appropriate parameter.
When the activity of the nerve signal is measured indirectly, the measurement becomes dependent on the ability of the measurement parameter to simulate the activity. If the patient suffers from some heart disease, which in particular may occur among patients in need of a heart therapy implant, this is not the case, and measurement in the heart will not then supply correct information about the activity of the nerve signal.
In addition to indirect measurement of the activity of the sympathetic nerve according to European Application 0 532 144, stimulation of the vagus nerve, more particularly its endocardiac ends, during impending tachyarrythmia has also been proposed (Max Schaldach "Electrotherapy of the Heart", 1992, Springer Verlag, Heidelberg, pp. 210-214).
In other electromedical therapy, e.g. the treatment of epilepsy, it is known to directly stimulate a nerve, more particularly the vagus nerve, by means of an implantable pulse generator. One such system having a helical electrode applied to the vagus nerve in the neck area is described in an article by Tarver et al.: "Clinical Experience with a Helical Bipolar Stimulating Lead", Pace, Vol. 15, October, Part II 1992, pp. 1545-1566. This system, however, only stimulates the nerve, and the pulse generator is controlled by means of an extracorporeally applied magnet.
SUMMARY OF THE INVENTION
It is an object of the present invention to provide a method and an apparatus for detecting a state of imminent cardiac arrhythmia, and for administering appropriate anti-arrhythmia therapy which avoids the above-discussed disadvantages of known devices and methods.
The above object is achieved in accordance with the principles of the present invention in a method and apparatus for detecting a state of imminent cardiac arrhythmia in response to activity in a nerve signal conveying information from the autonomic nerve system to the heart, by sensing neural activity of at least one of the sympathetic and vagus nerves using a sensor body placed in an extracardiac position for directly sensing such neural activity, with the sensed signal being supplied to a comparator which has a threshold value that defines a condition for the presence of arrhythmia. The comparator emits an imminent arrhythmia-indicating output signal depending on whether the sensor signal, representing the neural activity, meets the condition established by the comparator threshold. The sensor body may be placed for directly sensing the aforementioned neural activity in direct contact with the sympathetic and possibly vagus nerves.
The invention is described in greater detail with reference to an embodiment as disclosed in the attached drawings of a device according to the invention for heart therapy as applied in the above-described AICD defibrillator system. For illustrative--not restrictive--reasons, the device according to the invention will henceforth be designated in this description as a "nerve-stimulating heart defibrillator" or a "nerve-heart defibrillator" whose task is to terminate fibrillation in the heart. It is to be understood that also other tachyarrhythmias, such as impending but as yet unestablished fibrillation treated with ATP or cardioversion according to conventional techniques, can be treated and that the designation "nerve-heart defibrillator" in this context is a term only employed for explanatory purposes. Although the nerve-heart stimulator is explained and described herein in conjunction with a AICD-type defibrillator system, it is further understood that the nerve-heart stimulator can be employed independently without all the parts in the described defibrillator system.
DESCRIPTION OF THE DRAWINGS
FIG. 1 is a block diagram of a defibrillator system, embodying a nerve-heart defibrillator according to the invention.
FIG. 2 shows an example of a vagus nerve stimulator in the nerve-heart defibrillator.
FIG. 3 shows illustrative examples of patterns of vagus nerve stimulation pulses generated in accordance with the invention.
FIG. 4 shows an example of the structure of a nerve electrode suitable for use in accordance with the invention.
FIG. 5 is a block diagram of a further embodiment of a defibrillator system, embodying a nerve-heart defibrillator according to the invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
FIG. 1 shows an example of a defibrillation system using the nerve-heart defibrillator according to the invention, in which defibrillator implant is generally referenced 1. The implant 1 has an enclosure which may consist of e.g. a titanium capsule 3. The implant 1 includes a detection unit 5, a pacemaker unit 7, which can emit stimulation pulses to the heart both in the case of bradycardia and in the case of tachycardia, a nerve-heart defibrillation unit 9, an electrical defibrillation unit 11, a control unit 13, a diagnosis unit 15 and a telemetry unit 17. The different units in the implant 1 communicate internally via a databus 19.
The implant 1 communicates with an external programmer 21 via the telemetry unit 17, whereby communications primarily include the transmission of programming data to the implant 1 and transmission of diagnostic data, e.g. about different events in the heart, sensor signals and ECG signals, from the diagnostic unit 15.
The implant 1 is connected to a heart 25 via an electrode lead system 23 of attendant electrodes for emitting pacing as well as defibrillation pulses (including pulses with somewhat less energy than the level required for defibrillation, e.g. cardioversion pulses) to the heart 25 and for picking of signals indicative of the heart's condition. It should be noted that FIG. 1 is only schematic, and the signals designating the heart's condition also encompass sensor signals obtained from the sensing of heart-related physiological variables elsewhere in the, body, e.g. hemodynamics (pressure/flow) in the vascular system. As shown (enlarged) in FIG. 5, a blood pressure-sensing body 28 can be arranged, for example, in the patient's neck area around a blood vessel 29 (neck artery or vein), whereby the sensing body 28 may consist of a ring-shaped (possibly suturable) holder 30 and a sensing device on the inside of the holder device in the form of a pressure-sensitive cuff 31. The sensing body 28 supplies hemodynamic signals indicative of a blood pressure to the detection unit 5.
The implant 1 is also in connection with the sympathetic nerve 26 (a plus sign designates an activating effect on heart activity) and the vagus nerve 27 (a minus sign designates an inhibitory effect on heart activity) via the system 23 of electrodes and electrode leads in order to emit nerve-stimulating pulses to the vagus nerve 27 and blocking current to the sympathetic nerve 26 and for picking up heart-related nerve signals therefrom.
The defibrillator implant 1 accordingly includes, in addition to the nerve-heart defibrillator unit 9 described below, circuitry for performing the functions found in a modern defibrillator (AICD) of the type noted above. Thus, the heart's condition is monitored in the detection unit 5 by means of an IECG-monitoring device 51 and (in the embodiment of FIG. 5) hemodynamic signal monitor. Heart-related nerve signals are also monitored in the detection unit 5 in a nerve signal-monitoring device or neurosensor 53. Such a sensor 53 may be formed by a comparator with a threshold value defining a condition for the presence of an arrhythmia. If sensed nervous activity meets the condition, the comparator issues an imminent arrhythmia-indicating output signal. Thus normal sinus rhythm and abnormal conditions in the heart, the latter possibly being bradycardia, hemodynamically unstable tachycardia and ventricular fibrillation requiring treatment, as well as nerve (sympathetic) signal activity indicating that the above conditions are established or impending, are detected in the detection unit 5.
Data from the detection unit 5 are sent to the control unit 13 which, depending on the data, orders a requisite therapy, such as tachycardia-terminating heart stimulation, and also sends a command signal to at least one of the units 7, 9 and 11. In the case of a determination that tachycardia-terminating stimulation is need, the command signal is sent to the pacemaker unit 7.
Except for the nerve-heart defibrillator unit 9 and parts of the detection unit 5 (the neurosensor 53 in particular), the above-described components and functions are conventional in nature, as noted above. They will henceforth thus only be considered to the extent they relate to the nerve-heart stimulator unit 9, which will now be described, and the neurosensor 53, to be described subsequently, in the following description.
The nerve-heart stimulator unit includes a current generator 91 for nerve stimulation and is capable of supplying nerve-activating pulsed current with a balanced average current level, e.g. with a frequency range of 20 to 50 Hz, a pulse amplitude of 0-9 V and a pulse width of 0.1-1 ms, from a nerve stimulator 910, in addition to nerve-blocking direct current/high-frequency current, to be discussed subsequently. The unit 9 further includes a time control unit 92 which is capable of supplying control information to the current generator 91 regarding e.g., which activating and blocking pulses, pulse sequences and continuous output signals should be delivered via the electrode system 23 from the unit 9 to the sympathetic nerve 26 and vagus nerve 27, respectively, and also when the pulses are to be emitted. It should also be noted that the pulses supplied from the unit 9 may additionally include other suitable forms of pulses, such as dual diphasic pulses and alternatingly biphasic pulses separated by a pulse interval. The operating parameters of the current generator 91 and of the time control unit 92 are, like other parameters in the implant 1, programmable via the telemetry unit 17. Therapy supplied from the unit 9 can be supplied, repeatedly if need be, over a period of time, e.g. 5 to 10 seconds, suitable to the therapy. The time control unit 92 is shown, merely for illustrative purposes, as a separate unit in the unit 9. It can naturally be an integrated part of the current generator 91.
FIG. 2 shows an example of the nerve stimulator 910, which emits pulsed current for activating nerve stimulation, in the current generator 91. A voltage source 911 with a variable voltage V is connectable, via a switch 912, to a capacitor 913 with capacitance C. The capacitor 913 is also connectable, via the switch 912, to a capacitor 915, also with capacitance C. The capacitor 915 is connectable, via a switch 914, to an electrode output terminal 917. The nerve stimulator 910 can assume two states, a first state when the two switches 912 and 914 (both of which are controlled in parallel by the time control unit 92) assume the position marked in a FIG. 2, and a second state when the two switches 912 and 914 assume the position marked b. In the second state, the capacitors 913 and 915 are connected in series, whereupon the capacitor 913, which is charged to voltage V from the voltage source 911, is discharged via the capacitor 915 and the electrode output terminals 916 and 917. In the first state, the capacitor 913 is connected to the voltage source 911 by the switch 912, whereupon the capacitor 915 is also discharged via the electrode output terminals 916 and 917 and the patient. Control of events is exercised by the time control unit 92. The capacitance C for the capacitors 913 and 915 may, e.g., be 100 μF.
Examples of pulses emitted by the unit 9 are shown in FIG. 3. FIG. 3 shows the output signal over time t between the electrode output terminals 916 and 917 in FIG. 2. The pulse width t1 may be 0.5 ms, and the pulse interval t2 may be 50 ms (20 Hz) in moderate stimulation. In maximum stimulation, t2 is reduced to about 20 ms (50 Hz). The amplitude of the output voltage V is not affected as long as the output voltage V is above a threshold for stimulation of all fibers in the nerve. The threshold is electrode-related and amounts to about 5 volts for the electrode used here and described below.
An electrode (to be described below for the vagus nerve in conjunction with FIG. 4) in the system 23 and electrode cable for the respective nerve to be stimulated can consist of one or more flexible electrical conductors made of, e.g., MP35, each conductor being enclosed in electrical insulation made of, e.g., silicone rubber. The collective silicone rubber insulation on the conductors serves as the electrode cable's outer sheath. The electrode is devised for bipolar stimulation and has a first sub-electrode for the cathode and a second sub-electrode for the anode.
The sub-electrodes can be devised as cuffs, rings, helices or the like with e.g. platinum, and other electrically conducting metals and/or polymers, as well as carbon fibers/meshes as electrode material in contact with the nerve and an electrically insulating and mechanically resilient sheath of silicone rubber around the electrode material. The silicone rubber is pre-tensioned to some degree so that electrode, after implantation, retains mechanical and electrical contact with the nerve. The electrode can also be provided with suturing appliances and a device for mechanically relieving the load on the sub-electrodes, e.g. silicone rubber anchoring around the nerve with tensile relief for the conductors of the sub-electrodes. The electrode may also be anchored, with a constructively adapted design, in a blood vessel, preferably a venous vessel, immediately adjacent to the nerve.
A construction which is similar in all essential respects to the construction described for the stimulation electrodes can also be used for the sensor electrode employed for sensing heart-related activity in the sympathetic nerve. The vagus nerve could also be used, but the description relates to the sympathetic nerve as an example, whereby the nerve signals are sent to the nerve signal monitoring device 53 in the detection unit 5. The sensor electrode for the sympathetic nerve 26 can simultaneously serve as the stimulation electrode for the sympathetic nerve 26.
FIG. 4 shows an example of the construction principles for a cylindrical nerve electrode used herein and applicable to a nerve. FIG. 4 shows the vagus nerve 27 and an electrode 24, consisting of a sub-electrode 241 arranged distal to the heart and a sub-electrode 242 arranged proximal to the heart 25, arranged thereon. The arrow in FIG. 4 points toward the heart 25. The sub-electrodes 241 and 242 are for activating stimulation and are connected via conductors in the system 23 (FIG. 1) to the plus output terminal 916 and the minus output terminal 917, respectively, of the nerve stimulator 910. In case that the sub-electrode 24 leads to an anodic block, the result is that the main direction of nerve impulses is toward the heart 25.
As previously noted, the current generator 91 can also emit a current for blocking the sympathetic nerve 26, in addition to emitting the described pulses from the nerve stimulator 910 for activating the vagus nerve 27. One such blocking current can be achieved by additionally arranging, in the current generator 91, a pole-reversed nerve stimulator 910, described in FIG. 2, so the sub-electrode 242 becomes positive and so the sub-electrode 24 negative. Here, the frequency of the emitted blocking pulses should range from 200 to 500 Hz so the action potential in the nerve never has time to drop. Another way to achieve a nerve blockage is to provide the current generator 91 with a direct current generator for emitting a direct current which can be applied to the sympathetic nerve 26 as a direct current from the plus pole of the direct current generator for e.g. a few seconds. Also, instead of a direct current a square wave provided by a square wave generator can be employed.
Stimulation and any sensor electrodes for the sympathetic nerve and the vagus nerve are preferably implanted in the patient's neck area. For the vagus nerve 27, the preferred implantation site is in the neck area by or near the right middle portion of the external carotid artery. For the sympathetic nerve, the preferred implantation site, as regards stimulation, is the ganglion stellatum, whereby an electrode adapted to use with this thickened part of the nerve is employed.
The nerve-heart defibrillator described herein and including the unit 9 therefore achieves defibrillation of the heart 25 by delivering an activating current to the vagus nerve 27 and a blocking current to the sympathetic nerve 26 from the block 9 in response to one or more fibrillation conditions detected by the units 51, 52 and 53 in the detection unit 5. If the fibrillation persists, despite this treatment (which can be repeated if necessary) from the nerve-heart defibrillator unit 9, the control unit 13 can order collaboration with other parts of the defibrillator implant 1 which are relevant to the persistent fibrillation condition, so that one or more electrical defibrillation shocks are emitted by the block 11 for electrical defibrillation.
It should be noted that the nerve-heart stimulator unit 9 according to the invention in the defibrillator implant 1 is also capable of treating, as previously noted, impending but as yet unestablished fibrillation conditions (or other refractory tachyarrythmia) by prophylactically applying an activating current to the vagus nerve 27 and a blocking current to the sympathetic nerve 26, as described above.
The nerve signal monitoring device 53 contributes to improved monitoring by the detection unit 5 as regards tachyarrhythmias. The device 53 is, e.g., arranged to be able to observe changes in the signal patterns of the autonomic nervous system generated by e.g. myocardial ischemia, a condition which often precedes a tachyarrythmia. When the signal patterns are registered with an electrode as described herein (FIG. 4) and these patterns are processed (e.g. compared to patterns which are present under normal conditions), changes can be detected in sufficient time before dangerous tachyarrythmia becomes established.
One example of the course in treatment with the nerve-heart defibrillator unit 9, utilizing the neurosensor 53 and collaborating with other units in the defibrillator implant 1, is provided below.
As soon as the detector unit 5 detects impending fibrillation or some other dangerous, impending tachyrhythmia (e.g. a change in the activity of the autonomic nervous system), treatment from the unit 9 can be started in the form of light activation of the vagus nerve 27 for 5 seconds. If the detector unit 5 detects a return to a normal state of the heart 25, treatment is terminated. If the detector unit 5 continues to detect an abnormal condition for the heart 25, treatment will continue, supplemented with blocking of the sympathetic nerve, preferably at the ganglion stellatum, for a few seconds. If heart activity drops below a given rate because of the current delivered to the vagus nerve and the sympathetic nerve, the pacemaker block 7 automatically begins stimulating the heart 25 in order to maintain or restore its sinus rhythm. Treatment is terminated if the detector 5 now shows that the heart 25 has returned to a normal state. If this is not the case, the electrical defibrillator block 11 can be activated in order to shock the heart 25 in the conventional way.
Although the nerve-heart stimulator unit 9 has been described in the context of a conventional implant which also comprises many other units, the described example clearly only shows some of the therapy possibilities of the nerve-heart defibrillator 9 and shall not be interpreted as any restriction on its use. The nerve-heart stimulator unit 9 can alternatively, in treatment of supraventricular arrhythmias, only include the parts which stimulate the vagus nerve. In the treatment of supraventricular arrhythmias, the nerve-heart stimulator does not necessarily have to be implanted in the patient's body. It can also be used extracorporeally, e.g. for temporary use with appropriately situated external and internal nerve electrodes.
Although modifications and changes may be suggested by those skilled in the art, it is the intention of the inventors to embody within the patent warranted hereon all changes and modifications as reasonably and properly come within the scope of their contribution to the art.
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A device for detecting a state of imminent cardiac arrhythmia, relative to a normal state for a heart, in response to activity in nerve signals conveying information from the autonomic nerve system to the heart, contains a sensor body for sensing neural activity, a comparator with a threshold value forming a condition for the presence of an arrhythmia, the comparator emitting an arrhythmia-indicating output signal depending on whether neural activity meets the condition, and the sensor body being placeable in an extracardiac position for at least one of the sympathetic and vagus nerves. The sensor body directly senses activity in the nerve at that location in direct contact with the nerve. An implanted blood pressure sensing cuff also can be provided which generates signals indicative of blood pressure which can be evaluated in combination with the nerve signals for identifying the state of imminent cardiac arrhythmia.
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FIELD AND BACKGROUND OF THE INVENTION
This invention relates generally to liners for milking machine teat cups, and more particularly to improved teat cup liners that provide a superior seal against a teat upper portion and a controlled collapse around a teat lower portion to reduce tissue irritation and damage while enhancing the milking process.
Dairy animals, and particularly cows, are milked using automated milking machines. The milking machines include a milking unit including four teat cups, tubes downstream from the teat cups, a claw that acts as a manifold connected to the tubes for receiving milk, a pulsator, and pulsation tubes. The milking machines connect downstream with equipment for collecting milk.
The interface between milking machine and animal is a flexible liner inside a teat cup. A teat fits inside the liner during milking. An annular space between the liner and the teat cup is called a pulsation chamber. Vacuum from a vacuum pump is controlled by the pulsator to provide the pulsation of vacuum and pressure necessary to withdraw milk from the teats. A continuous vacuum is applied inside the liner to withdraw milk and keeps the milking unit attached to a cow. The continuous vacuum causes congestion of blood and other fluids in teat tissue. To relieve this congestion, atmospheric air is allowed into the pulsation chamber by the pulsator so that the flexible liner collapses onto the teat to relieve the congestion in the teat tissue. This pulsating action efficiently milks dairy animals.
The liner design is critical to obtaining efficient and complete milking while simultaneously providing maximum comfort and minimal irritation to the animal teats. Liners include at least two key components. First, is an upper dome portion and second is a lower barrel portion. Some liners include short tubes extending downstream from the liner barrel to connect to the milking claw. Other liners are designed to be connected to a separate short milk tube.
The upper dome portion includes an upper surface defining an opening through which a teat is inserted. The dome also includes an outer cylindrical wall with a lip to engage a teat cup. The dome defines an inner volume in which the vacuum acts to hold the milking unit on the animals. The shape and volume of liner domes have been studied for applying optimum vacuum and pressure to teats. (See U.S. Pat. No. 5,752,462.)
Liner barrels too have been the subject of considerable study. A basic liner barrel is cylindrical and essentially round in cross-section. When atmospheric pressure is applied in the pulsation chamber against the outer surface of the liner barrel, it collapses by flattening into a tight oval shape, and thereby applies pressure from two sides against a teat. Since teats are essentially round in cross-section, the application of pressure from two sides can cause undue stress, irritation, and excessive pressure on teat tissue.
In U.S. Pat. No. 3,967,587, the above problem with round barrels was addressed with a liner barrel having a square cross-section so that pressure was applied from four sides instead of two. The total pressure applied to a liner is the same regardless of whether the liner barrel is round or square in cross-section, so applying that pressure from four sides instead of two reduced the pressure and irritation on the teat by about one half.
One downside to a square-barreled liner is that during the vacuum phase, the teat tissue tends to expand into the corners of the square barrel and cause irritation of teat tissue. Further, the milking machine teat cups are held onto a teat by the vacuum in the liner. Therefore, a seal between teat and liner is necessary so that the milking machine does not fall off the cow during milking. Barrel liners with square cross-sections tend not to form as secure a seal with teats, and premature release can occur.
Thus, there is a need for a milking machine teat cup liner that will form a secure seal with a dairy animal teat, while simultaneously applying relatively uniform and gentle pressure to a teat for milking.
SUMMARY OF THE INVENTION
The present invention overcomes the excessive pressure applied by a liner barrel with a circular cross-section and the tissue irritation and vacuum loss that can result from a liner barrel with a square cross-section. The present invention utilizes a liner barrel with a round cross-section in its upper portion and a square cross-section in its lower portion to obtain a uniform seal with minimal irritation in the upper portion of a teat and with reduced pressure applied to the lower portion of a teat.
A liner in accordance with the present invention includes an upper dome portion having a top surface defining a teat opening, and a barrel joined to or formed integrally with the dome. The barrel has an upper transition portion with a substantially round cross-section and a lower portion with a substantially square cross-section. The upper portion can be tapered so that it has a generally round cross-section and becomes progressively smaller in diameter from top to bottom.
The upper round cross-section portion of the liner barrel creates a transition from the round cross-section of the liner dome to the lower square cross-section of the barrel. The beginning of the transition can begin at a lower end of a rounded shoulder inside the liner dome. Alternatively, the upper extreme of the transition section may be measured from the top surface of the dome when a dome shoulder is not present or has an irregular shape, for example.
Preferably, the transition portion is from between about one-half inch to one and a half inches long, and extends downward from the liner dome shoulder. The transition portion can begin from about three-quarters of an inch to about one and one half inch from the top of the liner dome. Another alternative is to have a transition portion that is up to about thirty percent of the total length of the liner barrel.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of a teat cup liner in accordance with the present invention;
FIG. 2 is a partial cross-section of a teat cup liner in accordance with the present invention;
FIG. 3 is a side view of a teat cup liner in accordance with the present invention;
FIG. 4 is a cross-section of a teat cup liner in accordance with the present invention; and
FIG. 5 is a cross-sectional view of a liner barrel taken along line 5 - 5 in FIG. 3 .
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
In the following detailed description of the preferred embodiments, the same reference numeral will be used to identify the same item in each of the drawings. Illustrated generally in FIGS. 1 through 4 is a teat cup liner 20 in accordance with the present invention, having an upper dome 22 , a barrel 24 , and an optional short milk tube 26 . Typically, liners 20 are made of rubber or silicone and are molded in a single piece.
Liners 20 are shaped and sized to fit within a teat cup of a milking machine (not illustrated). The teat cup and liner 20 cooperate to form an inflation that alternates applying pressure and vacuum from a vacuum pump (not illustrated) to massage a dairy animal's teat to withdraw milk.
The liner 20 dome 22 includes an annular wall 30 , an upper surface 32 , a teat opening 34 in the upper surface 32 , and a shoulder 36 . The annular wall 30 is connected to an upper portion 40 of the shoulder 36 , but is spaced apart from the rest of the shoulder 36 and the barrel 24 to define a recess 42 into which the top of a teat cup fits to secure the liner 20 to the teat cup. The upper surface 32 of the dome 22 is essentially flat, and the teat opening 34 is essentially round and sized to fit closely to a dairy animal teat inserted therethrough.
The dome shoulder 36 is spaced from the upper surface 32 to define a chamber 46 inside of the dome 22 . The shoulder 36 radius and spacing from the upper surface 32 can be selected to create a desired chamber 46 volume. In some liners, the shoulder 36 may not be well-defined or have a consistent radius. Nonetheless, in a preferred embodiment of the present invention, the shoulder 36 has a radius of about 0.351 inches and extends into the liner 20 dome 22 about 0.75 inches.
Extending downward from the shoulder 36 is the barrel 24 . The barrel 24 defines a bore 50 into which a dairy animal teat will fit. The barrel 24 of the present invention includes an upper transition portion 52 and a lower square portion 54 . The upper transition portion 52 changes in cross-sectional shape from the round dome 22 to the lower square portion 54 . Preferably, the transition portion 52 tapers from a relatively large internal diameter to a relatively small diameter from top to bottom. The preferred upper diameter is between about 0.828 inches and about 0.930 inches, and the shape is generally conical and tapers by about three to about ten degrees with the most preferred being about five degrees per side downward and inward. The preferred lower internal diameter is about 0.828 inches. The total length of the upper transition portion 52 is about 1.25 inches to about 1.38 inches long.
Preferably, the upper transition portion 52 has a length that is measured downward from the dome 22 shoulder 36 and has a length in the range of about three-quarters of an inch to about one and one-half inches. More preferably, the transition portion 52 is about 1.387 inches long. Alternatively, regardless of the dome shoulder 36 size, the top 53 of the transition portion 52 can begin from about three-quarters of an inch to about one and one-half inch down from the upper surface 32 of the dome 22 , and extend downward the length described above. The total length of the barrel 52 is between about 4.75 inches and 4.90 inches, and will increase (stretch) by about 0.919 inches plus or minus 0.060 inches when installed. The measurements are preferred only, and other measurements that accomplish the objectives herein are within the scope of the present invention. Indeed, measurements may vary depending on the animals being milked and the average teat size of the animals being milked.
The lower square portion 54 is desirable for reducing pressure on teat tissue and the corners 64 resist bending and remain relatively straight while the flat sides 66 collapse. The wall thickness of the barrel square portion 54 is about 0.100 inches, while the corner-to-corner dimensions X and Y ( FIG. 5 ) are preferably 0.942 inches across one side and 0.828 inches across the other side. The larger dimension X corresponds to corners with a 0.059 inch radius and the smaller dimension Y corresponds to a corner radius of about 0.197 inches. This differential causes the square barrel portion 54 to collapse in a roughly diamond shape for better control of the collapse and application of pressure to the teat.
The lengths of the transition portion 52 and the square portion 54 , may be expressed in terms of ratios, as well. For example, the transition portion 52 may be about 20% to about 40% with the most preferred being about 30% of the total barrel 24 length. As used herein “upper” means the upstream end of the liner 20 and “lower” means the downstream end of the liner 20 .
As indicated above, the liner 20 and teat combine to define an inner volume. The lower end of the inner volume of the liner 20 is defined by the inside rounded corner of the square barrel portions 54 adjacent to the short milk tube 26 . The upper end of the volume is defined by the inner top of the dome 22 .
The short milk tube 26 that extends down from the barrel 24 is optional and short milk tubes of other shapes and sizes, could be used, including short milk tubes that are separate elements to be attached to the liner 20 .
Between the barrel 24 and the short milk tube 26 is a thickened connector portion 28 that defines an annular recess 60 for engaging a hole in the bottom of a teat cup to maintain the liner 20 in a secure and extended position within the teat cup.
The foregoing detailed description of the drawings is meant for clearness of understanding only, and no unnecessary limitations therefrom should be read into the following claims. In particular, the terms “round” and “square” are general terms intended to cover generally oval and rectangular shapes, respectively. These terms may also include shapes with imperfect symmetry and unequal corner angles, for example, because exact shapes formed with flexible materials are not possible.
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A milking machine teat cup liner having a dome and a barrel, and the barrel has an upper transition portion and a lower square portion. The transition section mates with the round cross-section of the dome and the square cross-section of the lower square portion to provide superior vacuum seal with less irritation and damage to teat tissue.
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CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims the benefit of U.S. Provisional Patent Application No. 60/867,399, filed Nov. 28, 2006; U.S. Provisional Patent Application No. 60/868,342, filed Dec. 3, 2006; and U.S. Provisional Patent Application No. 60/870,398, filed Dec. 17, 2006. All of these related applications are incorporated herein by reference.
FIELD OF THE INVENTION
[0002] The present invention relates generally to memory devices, and particularly to methods and systems for writing and reading data to and from memory devices.
BACKGROUND OF THE INVENTION
[0003] Several types of memory devices, such as Flash memories, use arrays of analog memory cells for storing data. Each analog memory cell stores a quantity of an analog value, such as an electrical charge or voltage, which represents the information stored in the cell. In Flash memories, for example, each analog memory cell holds a certain amount of electrical charge. The range of possible analog values is typically divided into regions, each region corresponding to one or more data bit values. Data are written to an analog memory cell by writing a nominal analog value that corresponds to the desired bit or bits. The possible bit values that can be stored in an analog memory cell are also referred to as the memory states of the cell.
[0004] Some memory devices, commonly referred to as Single-Level Cell (SLC) devices, store a single bit of information in each memory cell, i.e., each memory cell can be programmed to assume one of two possible memory states. Higher-density devices, often referred to as Multi-Level Cell (MLC) devices, can be programmed to assume more than two possible memory states and thus store two or more bits per memory cell. In some cases, the number of bits stored per cell and the nominal analog values used in storing the bits may be varied in the course of operation of a memory.
[0005] For example, U.S. Pat. Nos. 6,643,169 and 6,870,767, whose disclosures are incorporated herein by reference, point out that there exists a tradeoff between the fidelity of data storage and the number of bits stored in a memory cell. The number of bits per cell may be increased when fidelity is less important and decreased when fidelity is more important. These patents describe a memory that can change between storage modes on a cell by cell basis.
[0006] Similarly, U.S. Pat. No. 6,466,476, whose disclosure is incorporated herein by reference, describes a multi-bit-per-cell non-volatile memory that stores different portions of a data stream using different numbers of bits per cell. In particular, data that require a high degree of data integrity (such as the header of a data frame) are stored using a relatively small number of bits per memory cell, while more error-tolerant data (such as music, images, or video) are stored using a relatively large number of bits per memory cell. Write circuitry decodes an input data stream and determines the number of bits to be written in each memory cell.
[0007] U.S. Patent Application Publication 2005/0024941, whose disclosure is incorporated herein by reference, describes a method and system for archiving data according to the desired data lifetime. For example, short-term data can be archived using larger programming voltage pulse increments than for long-term data; using a lower target threshold voltage than for long-term data; using wider programming voltage pulses than for long-term data; using higher starting programming voltages than for long-term data; using fewer programming voltage pulses than for long term data; using lower maximum programming voltages than for long term data; or using more levels per cell than for long-term data.
SUMMARY OF THE INVENTION
[0008] An embodiment of the present invention provides a method for storage that includes collecting information regarding respective performance characteristics of a plurality of memory units in a memory array, each memory unit comprising one or more cells of the memory array. The method includes receiving data for storage in the memory array, selecting a memory unit responsively to the respective performance characteristics, and storing the received data in the selected memory unit.
[0009] There is also provided, in accordance with another embodiment of the present invention, a method for storage, which includes receiving data from a host processor for storage by a memory controller in a memory array and receiving an input at the memory controller indicating that the memory controller is to operate in a power-saving mode. The data are written from the memory controller to the memory array in accordance with write parameters appropriate to the power-saving mode.
[0010] There is additionally provided, in accordance with an embodiment of the present invention, a method for storage, which includes receiving an instruction from a host processor to a memory controller to transfer data between a buffer and a memory array and receiving an input at the memory controller indicating that the memory controller is to operate in a high-throughput mode. The data are transferred between the buffer and the memory array using the memory controller at a throughput rate appropriate to the high-throughput mode.
[0011] Other embodiments of the present invention provide storage apparatus, which includes a memory controller that is configured to carry out the methods described above.
[0012] The present invention will be more fully understood from the following detailed description of the embodiments thereof, taken together with the drawings in which:
BRIEF DESCRIPTION OF THE DRAWINGS
[0013] FIG. 1 is a block diagram that schematically illustrates a system for data storage, in accordance with an embodiment of the present invention;
[0014] FIG. 2 is a flow chart that schematically illustrates a method for storing data, in accordance with an embodiment of the present invention; and
[0015] FIG. 3 is a flow chart that schematically illustrates a method for storing data, in accordance with another embodiment of the present invention.
DETAILED DESCRIPTION OF EMBODIMENTS
Overview
[0016] Embodiments of the present invention that are described hereinbelow provide methods and devices for controlling performance features of a memory, and particularly for controlling the power consumption of the memory. These methods are typically implemented in a memory controller, which handles requests by a host processor to write to, erase and read from the memory. In deciding how to handle write requests, the memory controller accesses a record, which may be stored, for example, in a database, of respective performance characteristics of different memory units (groups of cells) in the memory. The controller chooses one or more memory units to use in serving a given write requests by matching the performance characteristics of the memory units to performance requirements, such as power consumption or throughput.
[0017] In some embodiments, the controller has different operating modes, which are invoked by instructions from the host processor or other input. The controller handles read and write requests differently depending on the operating mode. For example, when the memory is installed in a battery-powered device, the controller may receive an input when the device is disconnected from external power, indicating that it should operate in a power-saving mode. In power-saving mode, the controller will choose to write data to memory units that are characterized by relatively low power consumption, as indicated by the record of performance characteristics mentioned above. Additionally or alternatively, while in power-saving mode, the controller may write the data in a manner that saves power by writing at low bit-density, low voltage, or coarse precision, or using small number of programming steps, and/or low pre-processing strength (specifically low encoding strength), for example.
System Description
[0018] FIG. 1 is a block diagram that schematically illustrates a system 20 for data storage, in accordance with an embodiment of the present invention. For the sake of illustration in the description that follows, it will be assumed that system 20 is part of a portable, battery-powered device, such as digital camera or portable media player. Such devices are normally capable of being connected to an external source of power, such as an AC power line or dedicated DC power supply or power supplied by a personal computer or other console via certain types of data connections, such as a USB connection. When the device is unplugged from the external power source, it is desirable that system 20 reduce its relative power consumption in order to prolong battery life.
[0019] System 20 comprises a memory subsystem 22 and a host processor 24 , which writes data to and reads data from the memory subsystem. The host processor may also provide indications of application requirements to the memory subsystem with respect to certain read and write requests. For example, for a given file that is to be written to the memory subsystem, the host processor may indicate the desired throughput rate and/or reliability of writing, storing and/or reading the data in the file. The memory subsystem uses these indications in determining how and where to store the data, as explained in detail hereinbelow.
[0020] Memory subsystem 22 comprises a memory array 26 , which is accessed and controlled by a memory controller 28 . The memory controller selects the cells in the array to which data are to be written and read from in response to each request from host processor 24 . The memory controller may also encode the data with suitable error correction codes before writing to the array, as well as decoding and correcting errors in the data upon readout. For these purposes, the controller may implement encoding and signal processing functions of the types described, for example, in PCT Patent Application PCT/IL2007/000580, filed May 10, 2007, which is assigned to the assignee of the present patent application and whose disclosure is incorporated herein by reference. Controller 28 and array 26 may be fabricated together on a single integrated circuit (IC) die, or they may alternatively be embodied in separate components, for example, on separate dies in a multi-chip package (MCP) or on separate IC. Although only a single memory array is shown in FIG. 1 , controller 28 may alternatively interface with multiple memory arrays simultaneously in the manner described herein. Additionally or alternatively, although host processor 24 is shown in FIG. 1 as being separate from controller 28 , the host processor and controller may be implemented as circuit component in the same chip
[0021] Memory array 26 comprises a matrix of memory cells 30 . In the examples that follow, it will be assumed that array 26 comprises analog non-volatile memory (NVM), such as MLC Flash memory. Alternatively, the principles of the present invention may be applied, mutatis mutandis, to memories of other kinds. For purposes of performance management by controller 28 , cells 30 are divided into groups, which are referred to herein as memory units. A group for this purpose may comprise only a single cell, but typically each memory unit comprises multiple cells, for example:
[0022] A group of cells that is simultaneously programmed or read (such as a row of cells sharing a common wordline).
[0023] A page, corresponding to a certain data value or set of data values that are simultaneously programmed to a group of cells, or a sector within a page.
[0024] A group of pages, such as a block (which is typically a group of pages that are simultaneously erased).
[0025] An entire die or plane (wherein a die typically comprises two planes).
[0026] Controller 28 maintains a record of performance characteristics of the memory units in a memory 32 . The record may conveniently be held in a control database 34 , but other data structures may alternatively be used for this purpose. Typically, memory 32 comprises a volatile memory, such as random-access memory (RAM), which is used by the controller to hold control information and may be backed up in memory array 26 when system 20 is powered down. Alternatively, database 34 may be held in an area of array 26 or in a separate programmable read-only memory (PROM) (assuming the database is written once and not updated thereafter).
[0027] Table I below lists some of the performance characteristics that may be recorded for each memory unit in database 34 . These characteristics are listed by way of example, and not limitation. In practice, database 34 may contain only a subset of these characteristics, and may also contain other relevant characteristics that are not listed below:
[0000]
TABLE I
MEMORY UNIT PERFORMANCE CHARACTERISTICS
Status (cells available for data, bad cells, etc.)
Capacity parameters (number of bits/cell).
Wear level (number of write/erase cycles performed on
this unit).
Signal characteristics, relating to the data storage
quality and reliability of the memory unit, including:
Noise variance of data stored in cells of the
unit.
Level of data retention error in the cells.
Number of errors detected in recent read
operations.
Number of program-and-verify (P&V) iterations
required to program cells in this unit.
Required number of erase iterations.
Speed characteristics, including:
Time required to program the cells in the unit.
Time required to erase the cells in the unit.
Sensing time (also referred to as busy time, i.e.,
time elapsed between a command by controller 28 to
read data from the memory unit and data output
from array 26).
The amount (and hence duration) of post-processing
(such as error correction code [ECC] decoding)
required to detect the data read from the unit.
The amount (and hence duration) of pre-processing
(such as ECC encoding) required to reliably
prepare the data for storage in this unit
Power consumption characteristics, including:
Power and maximum voltage value required for
writing data to the cells in the unit.
Power required for erasing the unit.
Power required for reading data from the cells in
the unit.
[0028] In practice, the power consumption characteristics may be understood more broadly to include a number of the signal and speed characteristics listed above. For example, in some memory devices, factors causing slow performance (such as a large number of P&V cycles required to write to a cell or a long sensing time to read from a cell) also result in larger power consumption. Similarly, large numbers of errors in the cells in a given unit may require controller 28 to expend more power in correcting the errors when reading from these cells.
[0029] The highest voltage value required to write data to a given unit (listed above under power consumption characteristics) may be determined using methods described in the above-mentioned U.S. Provisional Patent Application No. 60/868,342. In analog memory devices that are known in the art, nominal voltage values, which are typically uniform over the entire memory array, are used for writing the appropriate bit values to the cells. The analog values that are actually stored in the memory cells, however, often deviate from the nominal values in accordance with a certain statistical distribution. Therefore, in subsystem 22 , the statistical properties of the distribution of analog values stored in the cells of each memory unit may be measured, and the actual voltage values corresponding to different bit values may be adjusted for each unit based on these statistical properties. In consequence, different units may have different programming voltages, which are recorded in database 34 . For example, memory units whose analog values have a relatively low mean and low variance may be assigned a lower programming voltage and thus are identified as requiring lower programming power.
[0030] The performance characteristics of each memory unit may be tested in production of memory array 26 and recorded in database 34 prior to installation of the memory array in system 20 . Alternatively or additionally, these characteristics may be measured and/or updated after array 26 has been installed in system 20 . For example, the performance characteristics may be measured by a diagnostic routine that runs when subsystem 22 is first powered up, and deliberately initiates certain program, read and erase operations. This sort of routine may be re-run intermittently over the life of system 20 , typically as a background task of controller 28 . As another option, controller 28 may monitor normal read, write and erase operations in order to update the database.
[0031] Subsystem 22 has a power-saving mode, which is invoked by a power control input 36 to controller 28 . The input may be invoked by host processor 24 or manually by a user of system 20 . Alternatively or additionally, controller 28 may be configured to sense, via input 36 , whether system 20 is connected to an external source of power, as explained above, or is operating on internal battery power. The controller implements power-saving measures when operating on internal battery power. As a part of these measures, the controller may choose particular memory units to which it will write data depending on the specific power consumption characteristics of these memory units. The power-saving measures may be facilitated by preparatory and backup action that the control takes when external power is connected, as described further hereinbelow.
[0032] Behavior of controller 28 in power-saving mode may differ from one device to another. For example, digital cameras typically perform memory write operations while operating on battery power. In this case, the controller may choose memory units with low power consumption for writing images to memory. On the other hand, images are typically read out of the camera while the camera is connected to and receives power from a computer, so that power saving is not a consideration during read. By contrast, files are generally written to a portable media player (such as an MP3 player) while the player is connected to and receives power from a computer. In this case, it is more important that the files be written to subsystem 22 in a way that will facilitate low power consumption upon reading from memory array 26 , which is usually performed under battery power.
[0033] As noted above, controller 28 may also have high-throughput and high-reliability modes of operation, which are typically invoked by host processor 24 in response to application requirements. (Typically, these alternative modes require relatively high power consumption.) For example, the high-throughput mode may be invoked for storage of video data, as opposed to audio or still-image data, which can tolerate low throughput. As another example, controller 28 may use the high-throughput mode to write data rapidly from a buffer to memory array 26 when the buffer is about to overflow, or to read data from the memory array to a buffer when the buffer is nearly empty. The high-reliability mode may be used when writing data to the memory array in order to specify a certain coding strength to be used by the controller or a target bit error rate (BER) that is to be maintained in the stored data.
Methods for Reducing Power Consumption
[0034] FIG. 2 is a flow chart that schematically illustrates a method for storing data, in accordance with an embodiment of the present invention. Initially, power consumption characteristics of each memory unit in array 26 are measured, at a measurement step 40 . As noted above, this step may be carried out either by memory controller 28 in situ or by an external tester at the time of production, or both. Typical power consumption characteristics are listed above in Table I. The measured characteristics are recorded in database 34 , at a recording step 42 . After the power consumption characteristics have been recorded, memory subsystem 22 is ready to operate in power-saving mode when required. (Some aspects of power-saving mode operation, however, may be implemented without a database of power consumption characteristics.)
[0035] Controller 28 checks which mode it is to use upon receiving data from host processor for writing to memory array 26 , at a data input step 44 . As noted above, power control input 36 may be activated by various different components and factors. In the present example, it is assumed that input 36 is connected to sense when system 20 is receiving power from an external source (referred to herein as a “line”), at a power sensing step 46 .
[0036] If controller 28 determines at step 46 that the line power is on, it writes the data to memory array 26 in full-power mode, at a full-power writing step 48 . Typically, when lines power is available, the controller employs a strong pre-processing algorithm. For example, the controller may compute a strong error-correcting code, and may write the data together with the code to a memory unit at the full data density that the unit is able to sustain (i.e., using the full number of bits/cell that the cells of the memory unit are capable of storing). An another example, the controller may use a strong compression algorithm to compress the data in full-power mode and a weaker algorithm in power-saving mode. Optionally, the controller may choose the memory unit and coding scheme so as to reduce the power that will be required to read out the data subsequently, as described further hereinbelow with reference to FIG. 3 .
[0037] On the other hand, if controller 28 determines at step 46 that line power is off, it writes the data to memory array 26 in power-saving mode. For this purpose, the controller chooses one or more memory units whose power consumption characteristics (as recorded in database 34 ) indicate that they will require relatively low power to write, at a unit selection step 50 . The selected memory units, for example, may be those that require relatively low voltage and low power and few P&V cycles for programming, as explained above.
[0038] Controller 28 writes the data to the selected memory units in accordance with write parameters appropriate to the power-saving mode, at a low-power write step 52 . These write parameters may include, for example, data density, programming step size, and/or coding strength, as explained below:
[0039] Writing data at reduced density—The controller writes fewer bits/cell than would be possible if the cells were used at full capacity. Specifically, the controller may use only the lower voltage levels, thus exploiting only a narrow, low-voltage window within the overall range of levels supported by the cells. For instance, the controller may use only the two or four lowest levels of an eight-level (three bit) cell. As a result, the voltage and power applied in programming the cells are reduced.
[0040] Using larger incremental-step pulse programming (ISPP) increments in programming the cells—Flash memories are programmed by applying successive voltage steps to the cells, until the cells reach the desired levels. Increasing the size of the steps may reduce overall power consumption, although at the cost of larger programming errors.
[0041] Reducing the strength of pre-processing algorithms (such as ECC and/or compression algorithms, as noted above)—The “strength” of an ECC algorithm, for example, expresses the number and severity of errors that the code is able to correct or, equivalently, the computing power that must be invested in implementing the code. Reducing the strength of the code may mean using a simpler code or no code at all. In this way, the power consumed by the controller itself in code computation is reduced, at the possible expense of reduced reliability. When using this means of reducing power consumption, the controller may choose to write the data to memory units that have particularly good signal characteristics, as indicated in database 34 and listed in Table I above.
Additionally or alternatively, controller 28 may use other write parameters and may adopt other power-conserving measures, such as operating subsystem 22 at a reduced clock speed.
[0042] When lines power is restored to system 20 , controller 28 may compensate for the compromises that were made in writing data in power-saving mode, at a data compensation step 54 . Specifically, the controller may copy over data that were written at low density to other cells at full density. Additionally or alternatively, the controller may compress data that were written without compression in power-saving mode or may apply another stage of stronger compression to data that were only weakly compressed in power-saving mode. It may also be possible to perform maintenance tasks, such as refreshing cells, and to compute and store stronger error-correction codes at this stage. After copying the data in this manner, the controller may reuse the cells that originally held the data to storing additional data.
[0043] FIG. 3 is a flow chart that schematically illustrates a method for storing data, in accordance with another embodiment of the present invention. This method is directed particularly to writing data (typically in full-power mode) in a manner that will reduce the power needed to read the data in power-saving mode. It is useful, for example, in portable media players, which commonly write media files to memory while plugged into (and receiving power from) a personal computer, but then read and play back the media files under internal battery power.
[0044] The method of FIG. 3 is initiated when controller 28 receives data to write to memory array 26 , at a data input step 60 . The controller chooses memory units to which to write the data, at a unit selection step 62 , based on the power-consumption characteristics of the units as recorded in database 34 . For example, the controller may choose units that have low read power and/or low sensing time.
[0045] Controller 28 may choose a coding scheme that is appropriate for low-power readout, at a coding selection step 64 . Typically, coding schemes that permit the controller to minimize the amount of decoding computation are desirable in this context. For example, the controller may use a turbo code, which is decoded at read time using an iterative decoding scheme. As a result, when the controller decodes the data subsequently in power-saving mode, it may simply stop at a certain point in the iteration, in order to avoid excess power consumption, and output the data even if not all of the errors have been resolved. As another example, the controller may choose a coding scheme that is appropriate to the wear level of the memory unit: When the wear level is low, so that few errors are expected on readout, the controller may use a weak error-correcting code, which minimizes power consumption in decoding. At higher wear levels, the controller may use a stronger code in order to deal with the higher expected error rate. (On the other hand, given cells having different wear levels, the controller may still choose to store data in cells with the higher wear level if these cells are characterized by low power consumption.)
[0046] After choosing the memory units and coding scheme, controller 28 encodes and writes the data to memory array 26 , at a data writing step 66 .
[0047] Although the methods of FIGS. 2 and 3 are described, for the sake of convenience and clarity, with reference to system 20 ( FIG. 1 ), the principles embodied in these methods and in the use of the performance characteristics listed in Table I may similarly be applied in other sorts of memory and storage subsystems. It will thus be appreciated that the embodiments described above are cited by way of example, and that the present invention is not limited to what has been particularly shown and described hereinabove. Rather, the scope of the present invention includes both combinations and subcombinations of the various features described hereinabove, as well as variations and modifications thereof which would occur to persons skilled in the art upon reading the foregoing description and which are not disclosed in the prior art.
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A method for storage includes collecting information regarding respective performance characteristics of a plurality of memory units in a memory array, each memory unit including one or more cells of the memory array. When data are received for storage in the memory array, a memory unit is selected responsively to the respective performance characteristics, and the received data are stored in the selected memory unit.
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CROSS REFERENCE TO RELATED APPLICATIONS
This application is the National Stage of PCT/EP2009/050135 filed on Jan. 7, 2009, which claims priority under 35 U.S.C. §119 of German Application No. 10 2008 003 723.0 filed on Jan. 9, 2008, the disclosure of which is incorporated by reference. The international application under PCT article 21(2) was not published in English.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The invention relates to a pliers, such as a center cutter or a side cutter, having pliers jaws that are formed on pliers limbs and have a working region, the pliers limbs, which have gripping regions and are formed to cross over one another, being pivotably mounted by bearing bolts that connect a cover plate, and the pliers jaws being formed on the working region side of the cover plate and the cross-over region of the pliers limbs being formed on the other side of the cover plate. Here there are in question in particular high force ratio jaws, to which there belong also jaws such as pressing jaws and crimping jaws.
2. The Prior Art
A pliers of this kind is known for example from EP 331 927 B1. The disclosure content of this patent specification is hereby included in full in the disclosure of the present application, in respect of the basic construction of the pliers, in particular also in respect of the tooth-space engagement and of the run of the pliers limbs, as well as the principle of holding together by means of a cover plate, also for the purpose of incorporating features of the above-mentioned specification in claims of the present application.
Reference is also made to U.S. Pat. No. 2,806,394 A as prior art.
SUMMARY OF THE INVENTION
In regard to the known pliers, it is an object of the invention to improve the ease with which it may be handled.
This object is met according to a first aspect of the invention by the subject matter of claim 1 , it being provided that a tangential bend is formed in the pliers limbs on the gripping side relative to the cover plate, different pivot planes of the pliers limbs created thereby intersecting one another in the bend, the gripping regions running in one pivot plane and regions of the pliers limbs extending on the working region side of the tangential bend running in another pivot plane.
Because of the tangential bend, ease of handling is advantageously more favourable and improved, for example in the case that the pliers has to be placed such that the user's fingers engaging around the gripping region would already collide with a base or an upstanding feature. The tangential bend enables an advantageous separation of the working plane and the plane or the raised region in which the user's fingers engage around the handles. By virtue of the tangential bend being formed on the gripping side of the cover plate, the cutting region and also the cover-plate region of the known pliers remain unchanged. The favourable cutting properties continue to be obtained, for example in the case of a center or side cutter. In particular, a advantageous clearance for the cutter is also provided above and below.
A further solution to the problem is also provided by the features of claim 2 , it being provided that the pliers jaws are held together by only one cover plate, located on one side. In this way, placement of the pliers jaws directly against the working surface is enabled, when the single cover plate is located on the top. In principle, a cover plate may also be disposed underneath, and thus enable, in the upper side region, advantageous bringing against a workpiece or introduction into a working space.
Further features of the invention are explained below, which are in principle significant both combined with one or more of the features of the groups of features explained above, as well as however also independently.
Thus it is preferred that the cross-over region of the pliers limbs runs on the gripping side of the tangential bend. The gripping regions thus run through, in side view, together with the cross-over region of the pliers limbs, practically in a straight line. The tangential bend is then formed further toward the cover plate, preferably by virtue of bending deformation, in the pliers limb that runs through and is also preferably integral, so that the adjoining region of the pliers limbs, which is also referred as a whole as a head region of the pliers, extends in another pivot plane compared with the combined region of the gripping regions and the cross-over region.
As an alternative to this, the cross-over region of the pliers limbs may also run on the working region side of the tangential bend. The cross-over region then extends, preferably together with the portion of the pliers limbs forming the head region, in a common pivot plane, which is different from the pivot plane of the gripping regions.
More preferably, also only two different pivot planes are formed on the pliers.
It is further preferred that the cover plate is located on the inner side, when a tangential bend is provided; this means on the inner side of the angle in side view, thus in the space which encloses the smaller angle.
It is also further preferred that the rear sides of the pliers jaws, opposite from the cover plate, form a common contact face, which can be directly engaged against a workpiece or a base, because it is free of upstanding features. The rear sides of the pliers jaws, which in principle, as already stated above, may be the “upper side”, merge in this way into one another, preferably in alignment, thus form in any case a common contact plane in a substantial part of the rear side surface. A part of or the entire rear side of the cross-over region of a pliers limb in the cross-over region may also be incorporated into this contact plane. Because of the crossing-over arrangement, this rear side of the pliers limb in the region mentioned also results in additional stabilising of the contact.
The bearing mounting for the pliers jaws is further formed by means of a tooth-space engagement securing the pliers jaws to one another. This tooth-space engagement is preferably formed by a roller member. This roller member may be formed on one of the pliers jaws or also as a separate part, then preferably as a basically cylindrical pin.
When the tooth-space engagement is formed by the separate pin, it is further preferred that this bearing pin is of stepped form. A stepped embodiment of this kind enables the bearing pin to be held in a positive manner even when only one cover-plate is provided. While it is restrained against movement in one direction by the cover-plate, it is restrained against movement in the other direction—in the direction of its longitudinal axis—by the stepped formation. The stepped formation must not be formed as a continuous ongoing decrease in diameter. It may also be formed only by a groove, in which a protrusion from the pliers jaws engages.
In general form, it is provided that positive holding of the bearing bolt is achieved on the one hand by interaction with the cover plate and on the other hand by interaction with the pliers jaws.
In regard to the mounting of the preferably one cover plate by means of bearing pins, it is further preferably provided that these are held in the pliers jaws in rivet-like manner. For this, an end face of one of the bearing pins may form a part region of a rear side face of a pliers jaw or may be arranged offset relative to this; the latter preferably in the sense that a set back portion relative to the rear side face results. The other end region of the bearing pin may be formed in the manner of a rivet head.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention is explained further below with reference to the accompanying drawing, which however relates only to an embodiment. In the drawings,
FIG. 1 is a perspective view of the pliers;
FIG. 2 is a plan view of the pliers;
FIG. 3 is a view corresponding to FIG. 3 , from the rear;
FIG. 4 shows a cross-section through the item of FIG. 3 , sectioned along the line IV-IV;
FIG. 5 shows a side view of the pliers, relating the head region, with part of the jaw limb adjoining the cover plate on the grip region side, with a first arrangement of the tangential bend;
FIG. 6 is an illustration corresponding to FIG. 5 , with a second arrangement of the tangential bend;
FIG. 7 is an illustration of the pliers in the opened state;
FIG. 8 is an illustration corresponding to FIG. 6 , showing the rear side.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Shown and described is a pliers 1 formed as a center cutter having two pliers limbs, which form gripping regions 2 , 3 , these gripping regions each continuing initially into a cross-over region K of the pliers limbs and then integrally into a pliers jaw 4 , 5 . The pliers limbs are forgings. Each gripping region 2 , 3 and pliers jaw 4 , 5 is pivotably mounted on a bearing bolt 6 , 7 . The bearing bolts 6 , 7 extend transversely to a pivot plane of the pliers jaws in the front cutting region of the pliers jaws.
The gripping regions 2 , 3 cross over each other without any pivot pin before they pass into the region of the cover plate 8 which connects the pivot bolts 7 , 6 , accordingly after they change side relative to one another. The bearing bolts 6 , 7 pass through openings in the cover plate 8 that match the cross-section of the bolts. The cover plate 8 , which is disposed on one side only, according to FIG. 1 on the upper side of the pliers shown there, is of plate-like form. The cover plate 8 , which is of substantially elongate rectangular shape, has its longitudinal axis extending transversely to the longitudinal extent of the gripping regions 2 , 3 .
In order to fix the bearing bolts 6 , 7 , these have, at one end, (cf. for example FIG. 4 ) heads 9 and at the other end, are in the form of a rivet 10 . The heads have a frustoconical shape. The rivet portions are rounded transversely.
In the region of the cutters 11 , 12 that form the working region of the pliers jaws 4 , 5 and are directed toward one another, the cover plate 8 has an inwardly rounded recess, this for example advantageously with respect to a centring action for an item to be cut, such as for example a wire.
The pliers jaws 4 , 5 are formed to be visible on the working region side of the cover plate 8 , while the cross-over region K of the pliers limbs is formed on the other side of the cover plate 8 , the gripping region side of the cover plate 8 .
A roller member 14 , cf. for example FIGS. 3 , 4 and 7 , is housed between the bearing bolts 6 , 7 , at the same spacing from each bolt. The roller member 14 forms a kind of tooth space engagement between the cutting jaws and 12 . The roller member 14 is basically of cylindrical configuration. Its edges are bevelled.
The axial length of the roller member 14 corresponds more or less to the clear space from the underside of the cover plate 8 to the contact face 15 formed by the rear side of the pliers jaws 4 , 5 , see for example FIGS. 4 to 6 . Preferably the length is a little less. The roller member 14 , which is cylindrical and extends transversely to the cutters 11 , 12 , is thus seated, respectively partially, in a corresponding through cavity formed by two cavity portions 16 , 17 of the cutters 11 , 12 , see for example FIG. 8 . Since the cutters 11 , 12 are wedge-shaped and the roller member 14 is of cylindrical shape, the cavity portions 16 , 17 have, in the exemplary embodiment, a lens-shaped wall profile.
As will be apparent from a comparison between FIGS. 1 and 7 , the roller member 14 appears to move forwards when the pliers are opened and passes partially underneath the cover plate 8 . In reality, the cover plate 8 actually moves somewhat to the rear, cf. also FIGS. 3 and 8 which relate to the view from beneath.
The roller member 14 may be formed not only as a separate part, as in the exemplary embodiment, but may also be produced to be fixedly connected to one of the pliers jaws or even integral with this. Only the other pliers jaw then has the recess 16 .
The adjoining offset cross-over region K of the gripping regions 2 , 3 , on the gripping side behind the cover plate 8 , is clearly widened as compared with the gripping zone and the jaw zone (see for example the plan view according to FIG. 1 ). As a rule, the faces of the pliers limbs in this cross-over region K do not however engage on one another, but move with a spacing with respect to each other.
Referring to a side view, as is shown for example in FIGS. 5 and 6 , the tangential bend A is formed in each case on the gripping side of the cover plate 8 . The portions of the pliers limbs adjoining the tangential bend A to each side thus run in different pivot planes E 1 -E 1 and E 2 -E 2 respectively. The pivot planes E 1 -E 1 and E 2 -E 2 intersect one another in the region of the tangential bend A.
In the exemplary embodiment of FIG. 5 ( FIGS. 1 to 3 and 7 , 8 also relate in each case to this embodiment), the pliers jaws which appear in the side view in the form of plates that are as a whole in one piece and the region of the pliers limbs that extends underneath the cover plate run in the pivot plane E 1 -E 1 , while the cross-over region K together with the gripping regions 2 , 3 extends in the pivot plane E 2 -E 2 . The planes E 1 -E 1 and E 2 -E 2 together enclose an angle alpha, which is less than 180°.
The respective tangential bend A is, in further detail, formed by a bendingly formed portion 18 . The bendingly formed portion 18 is formed in the region of the pliers limb that is considerably reduced in thickness compared with the gripping regions 2 , 3 ; in the case of the embodiment according to FIG. 5 , also—seen form the cover plate 8 —before the step S formed in one pliers limb, which on the one hand is necessary for the cross-over of the pliers limbs, on the other hand, in the case of the other pliers limb, see for example FIG. 1 , is provided as a stabilising built-up mass of material. In this case, the notch-like cut between the cover plate and the step S or the related built-up material of the other pliers limb is also used for the bend.
The reduction in thickness is 10 to 70%, preferably for example 40 to 50%, of the thickness in the gripping region 2 , 3 . In this regard, with reference to the larger percent range, all intermediate values are also included in the disclosure.
The pliers 1 has only one cover plate 8 . With reference to the angle alpha, cf. FIGS. 5 , 6 , which in each case characterises the tangential bend A, this cover plate 8 is disposed in the interior of the angle.
On the side facing away from the cover plate 8 , the rear side of the pliers jaws 4 , 5 , the pliers jaws 4 , 5 form a common planar contact face 15 . In the exemplary embodiment, this contact face 15 extends, as shown, over practically the entire transverse region of the secured-together pliers jaws 4 , 5 and, in the elongate direction of the pliers, from a tip 19 as far as the tangential bend A. This contact plane is also free of upstanding features. It is therefore not for example interrupted by projecting pin portions or rivet heads. It is therefore suitable for direct engagement against a workpiece or for contact against a base.
In the case of the exemplary embodiment of FIG. 6 , the cross-over region K, or the rear side of this, is also incorporated into the contact face 15 . By contrast, in the case of the exemplary embodiment of FIG. 5 , only the rear side region of the pliers limbs that extends from the tip 19 as far as the tangential bend A, or the pliers jaws 4 , 5 formed by this, is incorporated into the contact face 15 .
In further detail, it is important that the angle alpha is between 110° and 175°; preferably between 150° and 165°, all degree values as well as fractions of degrees of the first range noted being here included in the disclosure.
The heads 9 mentioned of the bearing bolts 6 , 7 passing through the cover plate 8 form a planar, lower, outwardly lying boundary surface, which likewise lies in the contact face 15 mentioned or is optionally set back somewhat relative to this in the direction of the cover plate 8 .
In the same manner, the roller member 14 forms a lower end face, which likewise lies in the contact face 15 or, as in the case of the exemplary embodiment, is set back slightly from this in the direction of the cover plate 8 .
The roller member 8 itself is formed in a stepped manner. It has an upper larger-diameter region 14 a and a lower smaller-diameter region 14 b , see FIG. 4 .
Since the transition between the regions 14 a and 14 b is located at a corresponding shoulder 20 of the pliers jaws 4 , 5 and on the other hand, as already mentioned, the roller member 14 is covered, in the upward direction, by the cover plate 8 , the roller member 14 is thus secured in the pliers head in a positive manner.
All features disclosed are (in themselves) pertinent to the invention. The disclosure contents of the associated/attached priority documents (copy of the prior application) are hereby also included in full in the disclosure of the application, also for the purpose of incorporating features of these documents in claims of the present application.
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Pliers ( 1 ) as middle cutter or side cutter having plier jaws ( 4, 5 ) configured on plier legs, with a work range, wherein the plier legs with grip areas ( 2, 3 ) and configured to cross over one another around bearing bolts ( 6, 7 ) connected by a cover plate ( 8 ) are pivotably supported. The plier jaws on the working region side of the cover plate ( 8 ) and the crossing region (K) of the plier legs are configured on the other side of the cover plate ( 8 ). In order to improve the handling of these pliers, that relative to a side elevation, on the grip side with respect to the cover plate ( 8 ) in the plier legs, a tangential bend (A) is configured in which resultantly created different pivot planes (E 1 -E 1 ) or (E 2 -E 2 ) of the plier legs cross one another. The grip areas ( 2, 3 ) run in one pivot plane (E 2 -E 2 ) and in another pivot plane (E 1 -E 1 ) areas of the plier legs extended on the work range side of the tangential bend (A) run.
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TECHNICAL FIELD
[0001] The present invention relates generally to Digital Rights Management (DRM), and more particularly to a DRM solution that controls user distribution of excerpts of a content item.
BACKGROUND
[0002] This section is intended to introduce the reader to various aspects of art, which may be related to various aspects of the present invention that are described and/or claimed below. This discussion is believed to be helpful in providing the reader with background information to facilitate a better understanding of the various aspects of the present invention. Accordingly, it should be understood that these statements are to be read in this light, and not as admissions of prior art.
[0003] DRM solution are often considered as user unfriendly, a common complaint being that DRMs prohibit fair use as defined by the Digital Millennium Copyright Act, 1998 [see http://www.copyright.gov/legislation/dmca.pdf]. Among the many things considered as part of fair use is the right of an end user to cite or use an excerpt of a work, i.e. content item, for criticism, scholarship and so on. This is however not possible with the prior art DRM solutions.
[0004] It will therefore be appreciated that there is a need for a DRM solution that can:
Protect a content item against illegal or unauthorized use. Allow an end user to extract a portion of the content item and redistribute the portion to other end users who may then access the portion, regardless of whether or not these end users have access rights to the entire content item. Make it difficult for colluding end users to distribute an entire work freely by concatenating a set of excerpts of the work.
[0008] The present invention provides a part of such a solution: to wit, it provides the anti-collusion part.
SUMMARY OF INVENTION
[0009] The present application comprises a plurality of claims in each category. The skilled person will appreciate that the claims belong to a common inventive concept and that they cannot be expressed in an umbrella claim.
[0010] In a first aspect, the invention is directed to an apparatus for controlling distribution of licenses, a license being for an excerpt of a content item, the content item comprising a set of units, each excerpt comprising a subset of the set of units, the apparatus comprising a processor configured to: receive a license for the excerpt of the content item, the license comprising at least one indicator of the units covered by the license; retrieve stored information regarding licenses previously delivered to the apparatus; compare a limit value for the content item with the stored information combined with information from the license; and use the license to access the excerpt only if the limit value is not exceeded by the stored information combined with information from the license.
[0011] In a first preferred embodiment, the processor is further configured to receive the excerpt of the content item.
[0012] In a second aspect, the invention is directed to an apparatus for controlling distribution of licenses, a license being for an excerpt of a content item, the content item comprising a set of units, each excerpt comprising a subset of the set of units, the apparatus comprising a processor configured to: receive, from a device, an encrypted license for the excerpt of the content item, the license comprising at least one indicator of the units covered by the license; decrypt the encrypted license; retrieve stored information regarding licenses previously delivered to the first device; compare a limit value for the content item with the stored information combined with information from the license; and send the license to the device only if the limit value is not exceeded by the stored information combined with information from the license.
[0013] In a first preferred embodiment, the processor is further configured to: receive an encryption key from the device; and encrypt the decrypted license using the encryption key before sending it to the device.
[0014] In a third aspect, the invention is directed to an apparatus for controlling distribution of licenses, a license being for an excerpt of a content item, the content item comprising a set of units, each excerpt comprising a subset of the set of units, the apparatus comprising a processor configured to: receive, from a first device, a request for an authorization to send a license for the excerpt of the content item to a second device, the request comprising at least one indicator of the units covered by the license; retrieve stored information regarding licenses previously delivered to the second device; compare a limit value for the content item with the stored information combined with information from the request; and send the authorization to the first device only if the limit value is not exceeded by the stored information combined with information from the license.
[0015] In a fourth aspect, the invention is directed to an apparatus for controlling distribution of licenses, a license being for an excerpt of a content item, the content item comprising a set of units, each excerpt comprising a subset of the set of units, the apparatus comprising a processor configured to: receive a request for a license for the excerpt of the content item, the request comprising an identifier of a receiver of the license and at least one indicator of the units to be covered by the license; retrieve stored information regarding licenses previously delivered to the receiver; compare a limit value for the content item with the stored information combined with information from the request; and, only if the limit value is not exceeded by the stored information combined with information from the license: generate the license for the excerpt, the license comprising control words for the subset, and send the license to the receiver.
[0016] In a first preferred embodiment, the request is received from a first device having a license for the content item the first device being separate from the receiver.
[0017] In a second preferred embodiment, the request is received from the receiver, the receiver having received the excerpt from a second device.
[0018] In a third preferred embodiment, the processor is configured to obtain the control words for the subset from a master control word for the content item.
[0019] In a fourth preferred embodiment, the processor is configured to obtain the control words from a stored database.
[0020] In a fifth aspect, the invention is directed to a method for controlling distribution of licenses, a license being for an excerpt of a content item, the content item comprising a set of units, each excerpt comprising a subset of the set of units. An apparatus receives a license for the excerpt of the content item, the license comprising at least one indicator of the units covered by the license; retrieves stored information regarding licenses previously delivered to the apparatus; compares a limit value for the content item with the stored information combined with information from the license; and uses the license to access the excerpt only if the limit value is not exceeded by the stored information combined with information from the license.
[0021] In a sixth aspect, the invention is directed to a method for controlling distribution of licenses, a license being for an excerpt of a content item, the content item comprising a set of units, each excerpt comprising a subset of the set of units. An apparatus receives, from a device, an encrypted license for the excerpt of the content item, the license comprising at least one indicator of the units covered by the license; decrypts the encrypted license; retrieves stored information regarding licenses previously delivered to the first device; compares a limit value for the content item with the stored information combined with information from the license; and sends the license to the device only if the limit value is not exceeded by the stored information combined with information from the license.
[0022] In a seventh aspect, the invention is directed to a method for controlling distribution of licenses, a license being for an excerpt of a content item, the content item comprising a set of units, each excerpt comprising a subset of the set of units. An apparatus receives, from a first device, a request for an authorization to send a license for the excerpt of the content item to a second device, the request comprising at least one indicator of the units covered by the license; retrieves stored information regarding licenses previously delivered to the second device; compares a limit value for the content item with the stored information combined with information from the request; and sends the authorization to the first device only if the limit value is not exceeded by the stored information combined with information from the license.
[0023] In an eighth aspect, the invention is directed to a method for controlling distribution of licenses, a license being for an excerpt of a content item, the content item comprising a set of units, each excerpt comprising a subset of the set of units. An apparatus receives a request for a license for the excerpt of the content item, the request comprising an identifier of a receiver of the license and at least one indicator of the units to be covered by the license; retrieves stored information regarding licenses previously delivered to the receiver; compares a limit value for the content item with the stored information combined with information from the request; and, only if the limit value is not exceeded by the stored information combined with information from the license: generates the license for the excerpt, the license comprising control words for the subset and sends the license to the receiver.
BRIEF DESCRIPTION OF DRAWINGS
[0024] Preferred features of the present invention will now be described, by way of non-limiting example, with reference to the accompanying drawings, in which
[0025] FIG. 1 illustrates content divided into a plurality of units;
[0026] FIG. 2 illustrates a system according to a preferred embodiment of a decentralised approach of the present invention; and
[0027] FIG. 3 illustrates a system according to a preferred embodiment of a centralised approach of the present invention.
DESCRIPTION OF EMBODIMENTS
[0028] A co-pending application teaches a DRM solution, illustrated in FIG. 1 , in which an item of content 100 is partitioned into a set of sequential sequences called ‘units’ 110 , each unit being identified by a unit index (j). The content 100 thus comprises the set of units {U 0 , U 1 , U 2 , . . . , U n }. For delivery to an end user, the units are scrambled separately, a distinct control word (CW) being used for each unit. The resulting protected units 130 form a protected content 120 . The CWs are generated from a master CW that is comprised in a (global) content license that also is delivered to the end user.
[0029] The (first) end user may select a number of units to be sent to a second end user, generate the distinct CWs for the selected units and send the selected, protected units and an excerpt license comprising the generated, distinct CWs to the second end user. The use of a suitable CW generation algorithm ensures that the second user cannot generate CWs for other parts of the content than the parts of the excerpt. The selected number of units 110 make up a subset (or portion) of the content item 100 ; the subset is not necessarily contiguous, i.e. an excerpt license may be generated for units belonging to two or more separate parts such as for example U 0 -U 300 and U 500 -U 700 . This can enable generation of an excerpt license for the goals of a football match or the like.
[0030] However, it is conceivable that the first end user, or several end users, sends a plurality of excerpts to the second end user, thereby enabling the second end user to access the entire content item (or a major part thereof). The present invention seeks to overcome this problem.
[0031] An object of the present invention is thus to ensure that there is a limit to the amount of a content item that a device can access (i.e. render) through excerpt licenses. There are at least two possible solutions: a decentralised approach and a centralised approach.
[0032] Decentralised Approach
[0033] FIG. 2 illustrates a system according to a preferred embodiment of the decentralised approach of the present invention. The system 200 comprises a distributor 210 , a first device 220 , and a second device 230 .
[0034] The distributor 210 is configured to protect and distribute a content item 211 and the corresponding global content license 212 to a first device 220 , as described hereinbefore with reference to FIG. 1 .
[0035] The first device 220 is configured to select, following instructions from the first end user, an excerpt of the content 252 and to send the excerpt with a corresponding excerpt license 251 to the second device 230 .
[0036] The second device 230 is configured to receive, from the first end user device, the excerpt of the content 252 and the corresponding excerpt license 251 . If authorized to do so, the second device 230 is able to render the content of the excerpt 252 .
[0037] When the first device 220 has received instructions to send an excerpt 252 to the second device 230 , it generates the excerpt license 251 , as previously described herein, and sends the excerpt license 251 to the second device 230 . It is advantageous that the excerpt 252 is sent as well, but it should be appreciated that the excerpt 252 may also be received (possibly as part of a bigger excerpt or indeed the entire content item) by the second device 230 from a different source (or sources) provided that the excerpt license comprises sufficient information to allow the second device 230 to identify the units for which the excerpt license 251 comprises control words.
[0038] The excerpt license 251 preferably comprises an identifier of the content item, a list of pairs {unit index; CW}, and an integrity checksum. The first device 220 preferably encrypts the excerpt license 251 with a public key of the second device 230 .
[0039] Upon reception of the excerpt license 251 , the second device 230 decrypts it using its private key, if necessary, and checks the integrity of the excerpt license 251 using the integrity checksum. If the integrity is verified, then the second device 230 verifies if accessing the excerpt would bring it above the authorized limit for the content item. The limit may for example be expressed as a number of units and/or as a number of excerpts. To verify this, the second device 230 retrieves a stored counter (of e.g. the number of accessed units and/or excerpts) for the content identifier, adjusts the counter value with the relevant number from the received excerpt license (e.g. the number of units) and checks if the adjusted counter value exceeds a threshold value. If this is the case, then the second device 230 is not authorized to access the excerpt and advantageously erases the excerpt license (and possibly the excerpt). However, if the threshold is not exceeded, then the second device 230 updates the counter value and uses the excerpt license 252 to access the content of the excerpt 252 .
[0040] The second device 230 comprises at least one processor (not shown) configured to perform the necessary calculations and memory (also not shown) for storing a database with content identifiers and corresponding counter values. In a variant embodiment, the memory stores the index values of the units that it has already accessed, which allows the second device 230 to receive the same unit twice while it is only counted as one unit for purposes of the counter value.
[0041] Centralised Approach
[0042] FIG. 3 illustrates a system according to a preferred embodiment of the centralised approach of the present invention. The system 300 comprises a distributor 310 , a first device 320 , a second device 330 , and a central excerpt controller 340 .
[0043] The distributor 310 is configured to protect and distribute a content item 311 and the corresponding global content license 312 to a first end user, as described hereinbefore with reference to FIGS. 1 and 2 . The distributor 310 can also provide the central excerpt controller 340 with information, such as the master CW, that enables generation of an excerpt license.
[0044] The first device 320 is configured to select an excerpt 352 of the content that is to be sent with a corresponding excerpt license to the second end user. As in the decentralized approach, the excerpt 352 may be obtained by the second device 330 from other sources than the first device 320 , provided that the excerpt license comprises enough information to identify the units for which the excerpt license comprises control words.
[0045] However, in the centralized approach, the excerpt license may be delivered to the second device 330 in a number of different ways.
[0046] In a first variant, illustrated in FIG. 3 , the first device 320 sends a license request 322 to the central excerpt controller 340 . The license request 322 comprises the identity of the second device 330 (preferably in a certificate that further comprises the public key of the second device 330 ), a content identifier, a list of unit indices to be included in the excerpt license, and an integrity checksum. The license request 322 may, but is not necessarily protected by, for example, encryption.
[0047] The central excerpt controller 340 , which stores a record database for each managed device, verifies that the units of the excerpt will not bring the number of units (and/or excerpts) received by the second device 330 above a maximum authorized number of units (or excerpts) for the second device 330 . The database preferably comprises, for each device therein, a list of content identifiers and, for each content identifier, the units that have been delivered to the receiving device.
[0048] If the maximum number is reached, then the license request is refused; otherwise, the central excerpt controller 340 generates an excerpt license 351 and delivers this to the second device 330 . The excerpt license 351 preferably comprises the content identifier, a list of {index; CW} pairs, and an integrity checksum. The excerpt license is preferably encrypted using the public key of the second device 330 . The central excerpt controller 340 also updates its database with the information in the generated excerpt license 351 .
[0049] In a second variant, it is the second device 330 that sends the license request to the central excerpt controller 340 .
[0050] In the first and second variants, the central excerpt controller 340 may obtain the control words in at least one of the following ways. First, the central excerpt controller 340 may implement the CW generation algorithm and use the master CW to generate the unit CWs. Second, the central excerpt controller 340 may receive and store a complete list of unit CWs from the distributor 310 .
[0051] In a third variant, the first device 320 sends a license request 322 to the central excerpt controller 340 that verifies whether the second device 330 is authorized to receive the excerpt license, as in the first variant. If the second device 330 is authorized, then the central excerpt controller 340 returns an authorization to the first device 320 that then may generate the excerpt license and send it to the second device 330 .
[0052] In a fourth variant, the first device 320 encrypts the excerpt license with the public key of the central excerpt controller 340 . Upon reception of the excerpt license, the second device 330 sends the excerpt license to the central excerpt controller 340 , possibly together with its own public key. The central excerpt controller 340 decrypts the excerpt license and verifies if the second device 330 is authorized to access the excerpt. If this is the case, then the central excerpt controller 340 encrypts the excerpt license with the public key of the second device 330 and returns the re-encrypted excerpt license.
[0053] Upon reception of the excerpt license 351 , the second device 330 preferably decrypts it, using its private key, checks the validity of the integrity checksum. If the checksum is correct, then the CWs in the excerpt license 351 may be used to descramble and then render the excerpt.
[0054] The invention also relates to a computer program product, such as a DVD or a CD-ROM, that stores instructions, which, when executed by a processor, causes the processor to perform the method of the present invention.
[0055] It will be appreciated that the present invention can enable sharing of portions of a protected content, without making the entire content available to the recipient.
[0056] Each feature disclosed in the description and (where appropriate) the claims and drawings may be provided independently or in any appropriate combination. Reference numerals appearing in the claims are by way of illustration only and shall have no limiting effect on the scope of the claims.
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A method for controlling distribution of licenses, a license being for an excerpt of a content item, the content item comprising a set of continuous units, each excerpt comprising a subset of the set of continuous units, A device receives an identifier of a receiver of a license, and the license or a request to generate the license, the license or the request to generate the license comprising a content identifier and at least one indicator of the units covered by the license; retrieves stored information regarding licenses previously delivered to the receiver; compares a limit value for the content item with the stored information combined with information from the license or the request to generate the license; and allows the receiver access to the license only if the limit value is not exceeded by the stored information combined with information from the license or the request to generate the license Also provided is the device.
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BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] This invention relates to assembly of the rotor of a permanent magnet motor. The rotor has a plurality of recesses and overhung slots. Permanent magnet carriers and C-shaped lamination stacks are assembled in ring-shaped units interfitting with the recesses and overhung slots.
[0003] 2. Description of Related Art
[0004] This invention relates to the assembly of the rotor of a permanent magnet motor generally as described in U.S. Pat. No. 6,933,645.
SUMMARY OF THE INVENTION
[0005] Briefly, according to this invention, there is provided an apparatus for assembling a permanent magnet rotor. The rotor is comprised of a non-magnetic cylindrical shaft having a larger diameter central axial section and two smaller diameter bearing sections. The central section has an even number of recesses defining an even number of ribs and overhung slots. The apparatus comprises a temporary rotor fixture configured to slide over a smaller diameter bearing section of the rotor and to abut one end of the center section. The axial end of the fixture adjacent the center section has a configuration matching the center section including ribs and overhung slots whereby magnets in magnet carriers and C-shaped lamination stacks can be assembled over the ribs of the rotor fixture. The apparatus further comprises a split compression ring having an inner diameter that is sized to ride over the outer diameter of the C-shaped lamination stacks. Fasteners are provided for joining the split compression ring to compress the C-shaped lamination stacks sufficiently to provide a riding clearance between the C-shaped lamination stacks and the overhung slots.
[0006] Briefly, according to this invention, there is provided a method for assembling a permanent magnet rotor. The rotor is comprised of a non-magnetic cylindrical shaft having a larger diameter central axial section and two smaller diameter bearing sections, the central section having an even number of recesses defining an even number of ribs with overhung slots. The method comprises placing a fixture over a smaller diameter bearing section of the rotor abutting one end of the center section. The axial end of the fixture adjacent the center section has a configuration matching the center section including ribs and overhung slots. Next, the magnets in magnet carriers and the C-shaped lamination stacks are slid over the ribs of the fixture. Next, a split compression ring having an inner diameter that is sized to ride over the outer diameter of the C-shaped lamination stacks assembled on the ribs is placed over the row of assembled magnets and lamination stacks and joined so that the split compression ring compresses the C-shaped lamination stacks sufficiently to provide a riding clearance between the C-shaped lamination stacks and the overhung slots. Next, the assembled row of magnets in magnet carriers and C-shaped lamination stacks are slid onto the rotor. Finally, the compression ring is removed leaving an assembled row of magnets in magnet carriers and C-shaped lamination stacks in place on the rotor.
BRIEF DESCRIPTION OF THE DRAWINGS
[0007] Further features and other objects and advantages will become clear from the following detailed description made with reference to the drawings in which:
[0008] FIG. 1 shows a single row of magnet carriers and C-shaped laminations assembled on the temporary rotor fixture abutting one end of the rotor shaft;
[0009] FIG. 2 shows the split compression ring placed over the single row of magnet carriers and C-shaped laminations;
[0010] FIG. 3 shows the single row of magnet carriers and C-shaped laminations after being slid onto the rotor shaft and the split compression ring removed;
[0011] FIG. 4 is a perspective view of the temporary rotor fixture for assembling a row of magnet carriers and C-shaped laminations off the rotor shaft;
[0012] FIG. 5 is a perspective view of the split compression ring with the adjustment screws indicated;
[0013] FIG. 6 is an end view of a row of magnet carriers and C-shaped laminations assembled on the temporary rotor fixture and with the split compression ring in place to remove pressure on the overhung portions of the ribs; and
[0014] FIG. 7 is a perspective view in section of the assembled permanent magnet rotor.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0015] Referring to FIG. 7 , there is shown an assembled permanent magnet rotor shaft according to U.S. Pat. No. 6,933,645. The details of the magnet carriers and the C-shaped lamination stacks are set forth in that patent which is incorporated herein by reference. One of the challenges in assembling a permanent magnet rotor is to safely and securely assemble the rotor components on the shaft. The rotor is designed with tight tolerances and clearances. One of the major risks is gouging the shaft when sliding parts into position.
[0016] Referring to FIG. 7 , the shaft 10 comprises the foundation of the permanent magnet rotor. The shaft 10 is made of non-magnetic, high-strength material, such as nickel cobalt alloy. The shaft 10 has an interrupted cylindrical surface defined relative to the rotational axis of the rotor. At each end of the shaft, provisions are made for bearings 12 . The bearings 12 establish the rotational axis of the rotor. The shaft 10 has an even number of substantially identical recessed slots 13 . The slots 13 define substantially identical generally T-shaped ribs 11 with overhung dovetail surfaces 15 adjacent the slots. The magnets 19 are positioned within the slots held by a cradle or carrier 18 .
[0017] A plurality of generally C-shaped lamination stacks 17 comprised of magnetic, high-permeability material, such as electrical steel, surrounds the T-shaped ribs 11 as is clearly seen in FIG. 7 . The stacks are made up of individual sheets positioned perpendicular to the axis of rotation of the shaft. The sheets have edges that abut the overhung dovetail surfaces of the ribs. In this way, the C-shaped lamination stacks are mechanically secured to resist centrifugal forces when the shaft rotates.
[0018] A plurality of non-magnetic cradles 18 hold the permanent magnets in position in each slot. Each cradle 18 carries laminated permanent magnets 19 . Each cradle has a top wall and a bottom wall. These walls generally lie in the axial and circumferential directions when the cradle is installed in a slot on the rotor. The top wall abuts the magnets and resists the centrifugal force tending to throw out the magnets when the rotor rotates. The cradles are formed of lightweight, non-magnetic structural material, such as titanium. The cradles have axial end walls joined to the top and bottom walls. The bottom wall secures the axial end walls so that they do not collapse on the magnets when the top wall is urged radially outward at high rotation speeds. The axial end walls have edges that are configured to abut the overhung dovetail surface 15 of the ribs. The space between the axial end walls of the cradles is large enough to span the axial length of the magnets and also the axial length of the laminated stacks. Preferably, the axial length of the magnets and the laminated stacks is identical. The cradles are secured against centrifugal force by the engagement of the dovetail surfaces on the cradles and the overhung ribs. It is important to note that centrifugal force exerted by the cradle is applied directly to the ribs.
[0019] The assembly rotor, as shown in FIG. 7 , has multiple stages (circumferential rows of magnets and C-shaped lamination stacks forming ring-shaped units) which are slid axially into position. As stated, the rotor assembly comprises a non-magnetic, cylindrical shaft 10 having an axis of rotation and a generally cylindrical surface. An even number of recessed slots define an even number of ribs. The ribs have an overhung configuration. The overhung surfaces after assembly of the magnet carriers and C-shaped lamination stacks restrain the magnet carriers and C-shaped lamination stacks from moving radially outward from the axis of the rotor during rotation of the rotor.
[0020] Once assembled, the permanent magnets attempt to draw the C-shaped lamination stacks radially inward. This causes the components of a row to push radially outward as a reaction to the forces generated by the permanent magnets. This, in turn, results in a force across the overhung surfaces 15 . Forcing the stage axially along the shaft under these conditions can result in scoring or gouging of the ribs.
[0021] To overcome this problem, the stages are first assembled on a temporary rotor fixture 30 that at one axial end has a configuration substantially identical to the rotor. The temporary rotor fixture slides over the bearing 12 at one axial end of the rotor 10 and abuts the end of the ribs. The rotor fixture is rotated so that ribs 31 on the rotor fixture align with the ribs 11 on the rotor.
[0022] The magnet carriers 18 are slid onto the rotor fixture and axially positioned with one edge of each magnet carrier engaging the overhung portion of ribs on the rotor fixture. The C-shaped lamination stacks 17 are then placed in contact with the C-shaped lamination stacks held by the magnet carriers. FIG. 1 shows the assembled row on the rotor fixture.
[0023] The split compression ring 40 is then secured over the assembled row as shown in FIGS. 2 and 6 . The screws 41 are then turned in to compress the stage and remove pressure from the overhung surfaces of the ribs on the rotor fixture. The entire stage is then moved axially over the rotor into position as shown at FIG. 3 .
[0024] The split compression ring 40 forms a clamp. The clamp is made so that it can apply pressure to push the components of the stage off the overhung surface of the ribs. The clearances of the components are set in a way that when components are pushed inward toward the center of the shaft, the components have acceptable clearances for sliding along the shaft.
[0025] After the stage is in position, the split compression ring or clamp 40 is removed allowing the components of the row to expand into the final assembly position. The process is then repeated to place an additional row in place on the rotor.
[0026] Referring to FIG. 4 , the rotor fixture is shown in more detail. At one axial end, the fixture has ribs corresponding to the ribs on the rotor. The rotor fixture is formed of a non-magnetic material.
[0027] Referring to FIG. 5 , the split compression ring 40 is formed of a non-magnetic material, such as 300 Series stainless steel. Adjustment screws 41 have swivel heads at the end near the inner diameter of the compression ring so as to conform to the inner diameter when tightened in place. Thus, pressure can be applied to each component of the stage individually. This is accomplished by the adjustment screws aligned radially with each component. Preferably, a sleeve of soft material, such as Teflon®, is provided between the clamp and the rotor components so that the spit compression ring or clamp does not damage the components of the stage.
[0028] Having thus described my invention with the detail and particularity required by the Patent Laws, what is desired protected by Letters Patent is set forth in the following claims.
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Apparatus and method for assembling a permanent magnet rotor comprising a rotor fixture configured to slide over a smaller diameter bearing section of the rotor and abutting one end of a center axial section of the rotor and a split compression ring having an inner diameter that is sized to ride over the outer diameter of magnets in magnet carriers assembled on the rotor fixture.
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CROSS-REFERENCE TO RELATED APPLICATION
This disclosure is a continuation of U.S. patent application Ser. No. 13/835,641 filed Mar. 15, 2013.
BACKGROUND
This disclosure relates to short recoil weapons, and more particularly to the Browning M2 0.50 caliber (including all variants) and Browning 1919 0.30 caliber machine guns.
Short recoil weapons are generally configured to lock a bolt and a barrel together for a predetermined distance to ensure that energy produced by a fired cartridge is dissipated to a safe level prior to opening a breech. Prior to firing, a breech lock disposed in the barrel extension selectively engages a corresponding locking surface of the bolt (also described as the bolt lock interface), locking the bolt and barrel together. After the round is fired, the bolt, barrel extension and barrel travel together the predetermined distance. Then the breech lock disengages the bolt allowing the bolt to accelerate toward the rear of the receiver independently of the barrel.
While the bolt and the barrel are locked together and after the weapon is fired, a substantial portion of the recoil force is communicated to the locking surface of the bolt adjacent to the breech lock recess. Accordingly, a common wear point is the locking surface due to high cyclic rates of fire. After the amount of wear of the locking surface exceeds a predetermined wear threshold, the weapon may become dysfunctional or unsafe for use. Accordingly, even though only a small portion of the bolt is worn or distressed beyond allowable limits, the entire bolt is generally discarded.
SUMMARY
An insert for a gun bolt according to an example of the present disclosure includes a gun lock interface insert sized to be fixedly secured in a gun bolt. The gun lock interface insert includes a first guide structure and a second guide structure extending from a main body. The main body defines a first engagement surface and a second engagement surface. The first engagement and second engagement surfaces space apart the first guide and second guide structures. Each of the first engagement and second engagement surfaces is configured to selectively engage a breech lock.
In a further embodiment of any of the forgoing embodiments, the main body includes a first surface spaced apart from a second surface, and first and second surfaces spacing apart the first engagement and second engagement surfaces. A cross-sectional profile of the gun lock interface insert is generally trapezoidal. The cross-sectional profile is defined by each of the first and second surfaces, the first engagement and second engagement surfaces, and the first guide and second guide structures.
In a further embodiment of any of the forgoing embodiments, each of the first guide and second guide structures is sized to be slideably received in a corresponding channel of a barrel extension.
A lock interface insert for a gun bolt according to an example of the present disclosure includes a main body dimensioned to bound a breech lock recess defined in a gun bolt. The main body defines at least one engagement surface configured to engage a breech lock selectively received within the breech lock recess, and at least two outward guides extending from the main body and sized to be slideably received in a corresponding channel of a barrel extension.
In a further embodiment of any of the forgoing embodiments, each of the at least two outward guides is adjacent to the at least one engagement surface.
In a further embodiment of any of the forgoing embodiments, each of the at least two outward guides defines a bevel sloping towards the at least one engagement surface.
In a further embodiment of any of the forgoing embodiments, the at least one engagement surface includes a first engagement surface and a second engagement surface opposite the first engagement surface.
In a further embodiment of any of the forgoing embodiments, the main body defines a reference plane intersecting the at least two outward guides, and the first engagement and second engagement surfaces are arranged such that the main body is symmetrical about the reference plane.
In a further embodiment of any of the forgoing embodiments, each of the at least two outward guides is symmetrical about the reference plane.
In a further embodiment of any of the forgoing embodiments, a cross section of the main body taken transverse to the at least one engagement surface defines a trapezoidal geometry.
A method of repairing a bolt assembly according to an example of the present disclosure includes the steps of removing a portion of material adjacent to an engagement surface of a bolt to define a shaped cavity, providing a lock interface insert, and fixedly securing the lock interface insert at least partially within the shaped cavity. The lock interface insert includes a main body dimensioned to bound a breech lock recess adjacent to the shaped cavity. The main body defines at least one engagement surface configured to engage a breech lock selectively received within the breech lock recess.
In a further embodiment of any of the forgoing embodiments, the step of fixedly securing includes forming an interference fit to minimize relative movement between the lock interface insert and the bolt.
In a further embodiment of any of the forgoing embodiments, the step of inserting includes press fitting the lock interface insert in the shaped cavity.
In a further embodiment of any of the forgoing embodiments, the step of inserting includes inserting the lock interface insert completely within the shaped cavity.
In a further embodiment of any of the forgoing embodiments, the portion of material is adjacent to the breech lock recess.
In a further embodiment of any of the forgoing embodiments, the bolt defines a top and a bottom extending between a first bolt end and a second bolt end, and the shaped cavity is spaced apart from at least one of the top and the bottom.
In a further embodiment of any of the forgoing embodiments, the lock interface insert includes at least two outward guides extending from the main body. Each of at least two outward guides is sized to be slideably received in a corresponding channel of a barrel extension.
In a further embodiment of any of the forgoing embodiments, at least one engagement surface includes a first engagement surface and a second engagement surface opposite the first engagement surface.
A further embodiment of any of the foregoing embodiments includes removing the lock interface insert from the shaped cavity and fixedly securing the lock interface insert at least partially within the shaped cavity such that a different one of the first engagement surface and the second engagement surface bounds the breech lock recess.
In a further embodiment of any of the forgoing embodiments, a cross section of the main body taken transverse to the first engagement surface and the second engagement surface defines a trapezoidal geometry.
These and other features disclosed herein can be best understood from the following specification and drawings, the following of which is a brief description.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of a prior art machine gun.
FIG. 2 is a bottom view of a bolt of the prior art machine gun of FIG. 1 .
FIG. 3 is a partial side view of the bolt of the prior art machine gun of FIG. 1 , the bolt in an installed and unlocked position.
FIG. 4 is a partial side view of a worn surface of the bolt of the prior art machine gun of FIG. 3 .
FIG. 5 is a bottom view of a lock interface insert installed in a bolt.
FIG. 6 is a perspective view of the bolt and the lock interface insert of FIG. 5 in an uninstalled position.
DETAILED DESCRIPTION
FIG. 1 illustrates a perspective view of prior art machine gun 10 , and more particularly an M2 0.50 caliber machine gun. The machine gun 10 includes a receiver 12 disposed at a first weapon end 15 and a barrel 14 disposed at a second weapon end 17 . The receiver 12 includes a chamber 13 for receiving a bolt and a barrel extension 16 (shown in FIG. 3 ). The components of the machine gun 10 are well known.
FIG. 2 illustrates a bottom view of a bolt 18 of a prior art machine gun 10 . The prior art bolt 18 includes a first bolt end 27 and a second bolt end 29 . The bolt 18 is configured to be partially received in a barrel extension 16 (not shown). The bolt 18 includes a pair of rails 31 extending outward from a pair of lateral sides 24 between the first and second bolt ends 27 , 29 . The rails 31 include an upper surface 41 and a lower surface 43 each parallel to a bottom 20 and a top 22 of the bolt 18 . The rails 31 are configured to be slideably received in a pair of corresponding channels of the barrel extension 16 (not shown). The bolt 18 also defines a breech lock recess 30 extending inward from the bottom 20 of the bolt 18 for receiving a breech lock 26 (shown in FIG. 3 ).
FIG. 3 illustrates a partial side view of the bolt 18 and barrel extension 16 installed in the receiver 12 . The breech lock 26 is disposed within an inner cavity 28 defined by the barrel extension 16 . The breech lock 26 is free to move within the inner cavity 28 in a direction C. A receiver 12 includes a ramp 36 with a breech lock cam 37 for engaging a locking cam 35 of the breech lock 26 . During counter-recoil, the barrel extension 16 moves in a direction B with respect to the ramp 36 , causing the breech lock 26 to engage the breech lock cam 37 . The breech lock 26 extends upward in the direction C toward the breech lock recess 30 . The breech lock 26 engages the lock interface 32 of the bolt 18 adjacent to the breech lock recess 30 , causing the bolt 18 and the barrel extension 16 to lock together.
When the machine gun 10 is fired, a portion of a recoil force F is absorbed by a barrel buffer spring 40 and a driving rod spring 42 . However, a significant amount of the recoil force F is communicated to the lock interface 32 while the bolt 18 is locked to the barrel extension 16 by the breech lock 26 . Additionally, the recoil force F causes the bolt 18 to be driven in a slightly diagonal direction D along a bolt engagement surface 33 of the breech lock 26 when the bolt 18 and the barrel extension 16 are locked together. Accordingly, the lock interface 32 begins to wear as the machine gun 10 fires (shown in FIG. 4 ). After the amount of wear of the lock interface 32 exceeds a certain threshold, the operation of the machine gun 10 becomes unreliable. The operation of the machine gun 10 is well known.
FIG. 5 illustrates a bottom view of a bolt 118 and a lock interface insert 150 in an installed position. FIG. 6 illustrates a bottom perspective view of a portion of the bolt 118 and the lock interface insert 150 of FIG. 5 with the lock interface insert 150 in an uninstalled position. In this disclosure, like reference numerals designate like elements where appropriate and reference numerals with the addition of one-hundred or multiples thereof designate modified elements that are understood to incorporate the same features and benefits of the corresponding original elements.
As shown in FIG. 6 , the bolt 118 defines a shaped cavity 145 for receiving a portion of the lock interface insert 150 . The shaped cavity 145 extends between a forward surface 146 and a rear surface 148 of the bolt 118 along a horizontal axis H and adjacent to the breech lock recess 130 . The forward surface 146 defines a forward angle A F and the rear surface 148 defines a rear angle A R with respect to a floor 149 of the shaped cavity 145 . Each of the angles A F , A R is generally acute. The floor 149 extends at least partially between the upper and lower surfaces 141 , 143 of the rails 131 , which serve to guide the bolt's 118 movement with respect to the barrel extension 16 .
The lock interface insert 150 includes a main body 152 . The main body 152 includes a first insert surface 154 configured to form a flush and continuous surface with the bottom 20 the bolt 118 (shown in FIG. 5 ) to engage the receiver 12 . The main body 152 includes a second insert surface 156 substantially parallel to the first insert surface 154 and adjacent to the floor 149 of the bolt 118 when the lock interface insert 150 is placed within the shaped cavity 145 . The main body 152 includes a pair of first sides 160 opposite each other and adjacent to the first and second insert surfaces 154 , 156 . The first sides 160 are configured to form a flush and continuous surface with the lateral sides 124 of the bolt 118 (shown in FIG. 5 ).
The main body 152 includes a front engagement surface 168 and a rear engagement surface 170 opposite each other for selectively engaging the breech lock 26 . The front and rear engagement surfaces 168 , 170 are disposed between the first and second insert surfaces 154 , 156 . The front engagement surface 168 is generally oriented at the forward angle A F and the rear engagement surface 170 is generally oriented at the rear angle A R with respect to the second insert surface 156 . The front engagement surface 168 is configured to be substantially parallel to the forward surface 146 of the bolt 118 , and the rear engagement surface 170 is configured to be substantially parallel to the rear surface 148 of the bolt 118 . The rear engagement surface 170 may be configured to be substantially parallel to the bolt engagement surface 33 to redirect a portion of the recoil force F (shown in FIG. 3 ) perpendicularly from the rear engagement surface 170 and into the bolt engagement surface 33 of the breech lock 26 .
As shown in FIG. 5 , a cross section of the lock interface insert 150 is generally trapezoidal. The forward and rear angles A F , A R of the shaped cavity 145 may be substantially equal to each other and generally acute. This allows the lock interface insert 150 to be held captive in the shaped cavity 145 by the forward and rear surfaces 146 , 148 of the bolt 118 and minimizes the possibility that the lock interface insert 150 may become dislodged during operation of the machine gun 110 . As shown in FIG. 6 , the lock interface insert 150 is symmetrical along the horizontal axis H and can be inserted into the shaped cavity 145 with either the front or rear engagement surfaces 168 , 170 facing the breech lock 26 . However, other shapes and configurations of the lock interface insert 150 are contemplated.
The lock interface insert 150 includes a pair of outward guides 157 extending outward from the main body 152 along the horizontal axis H. The outward guides 157 are adjacent to the second insert surface 156 of the main body 152 and form a flush and continuous surface with the rails 131 of the bolt 118 when the lock interface insert 150 is installed in the shaped cavity 145 . Each of the outward guides 157 may include a pair of bevels 172 for realigning the lock interface insert 150 within the shaped cavity 145 along the horizontal axis H. Realignment occurs by engagement of the bevels 172 with an interior surface of the corresponding channels (not shown) of the barrel extension 16 . The bevels 172 also facilitate the insertion of the lock interface insert 150 into the shaped cavity 145 . The outward guides 157 may be integrally formed with the main body 152 .
The shaped cavity 145 and the lock interface insert 150 may be configured to form an interference fit when lock interface insert 150 is slide fitted along the horizontal axis H. Accordingly, no fasteners are required to secure the lock interface insert 150 within the shaped cavity 145 . The outward guides 157 also keep the lock interface insert 150 locked in place.
The lock interface insert 150 can be formed by machining, forging, casting or other methods depending on materials used and fitting specifications. The lock interface insert 150 may be formed from a second material including steel, alloy or other metals depending on military specifications and other requirements. The second material of the lock interface insert 150 may have a greater hardness than a first material of the bolt 118 . The second material of the lock interface insert 150 may also be different from the first material of the bolt 118 in metallurgy. Forming the bolt 118 and the lock interface insert 150 from different materials allows each of the components to be separately optimized according to performance requirements, cost and other parameters.
Installation of the lock interface insert 150 is as follows. A portion of the prior art bolt 18 adjacent to the lock interface 32 (shown in FIGS. 2-4 ) is removed to define the shaped cavity 145 (shown in FIG. 5 ). Removal of the portion of the prior art bolt 18 may be performed by methods generally known in the art including machining. In another embodiment, the shaped cavity 145 is formed during the manufacturing process. Thereafter, the lock interface insert 150 is inserted into the shaped cavity 145 along the horizontal axis H. The lock interface insert 150 may be press fit into the shaped cavity 145 with a conventional insertion tool (not shown).
When the rear engagement surface 170 wears beyond the predetermined wear threshold, the operator may reverse the orientation of the lock interface insert 150 by removing the lock interface insert 150 from the shaped cavity 145 , rotating the lock interface insert 150 about a rotational axis R (shown in FIG. 6 ), and reinserting the lock interface insert 150 into the shaped cavity 145 with the front engagement surface 168 adjacent to the breech lock 26 (shown in FIG. 5 ). In this way, the advantage of a lock interface insert feature may be extended. Additionally, a sufficient amount of the rear engagement surface 170 is configured to extend below the breech lock recess 130 (shown in FIG. 5 ) even though a portion of the surface 170 is worn. The remaining portion of the rear engagement surface 170 is able to contact the forward surface 146 of the bolt 118 when the lock interface insert 150 is rotated to retain the lock interface insert 150 within the shaped cavity 145 . The operator may discard the lock interface insert 150 to be replaced by another lock interface insert once both the front and rear engagement surfaces 168 , 170 are worn.
Accordingly, the lock interface insert 150 provides several benefits over the prior art bolt 18 . Only the lock interface insert 150 is discarded after the surfaces 168 , 170 are worn beyond a predetermined wear threshold rather than the entire bolt 18 . The bolt 118 is field reparable by replacement of the lock interface insert 150 . Accordingly, a lower quantity of bolts may be kept in inventory and the repair time of the bolt is reduced. Additionally, the front and rear engagement surfaces 168 , 170 of the lock interface insert 150 provide two separate wear surfaces, prolonging the duration between servicing of the bolt 118 .
Although the different embodiments have the specific components shown in the illustrations, embodiments of this disclosure are not limited to those particular combinations. It is possible to use some of the components or features from one of the embodiments in combination with features or components from another one of the embodiments.
The preceding description is exemplary rather than limiting in nature. Variations and modifications to the disclosed embodiments may become apparent to those skilled in the art that do not necessarily depart from the essence of this disclosure. The scope of legal protection given to this disclosure can only be determined by studying the following claims.
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An insert for a gun bolt according to an example of the present disclosure includes, among other things, a gun lock interface insert sized to be fixedly secured in a gun bolt. The gun lock interface insert includes a first guide structure and a second guide structure extending from a main body. The main body defines a first engagement surface and a second engagement surface. The first engagement and second engagement surfaces space apart the first guide and second guide structures. Each of the first engagement and second engagement surfaces is configured to selectively engage a breech lock. A method of repairing a bolt assembly is also disclosed.
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CROSS REFERENCE TO RELATED APPLICATIONS
This application is a continuation-in-part of co-pending application, Ser. No. 310,801, filed Nov. 30, 1972, now abandoned, the contents of which are expressly incorporated herein by reference.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to new adrenolytic ergoline derivatives.
2. Description of the Prior Art
Dihydrolysergamine and 1-methyl-dihydrolysergamine, the starting materials for the preparation of the compounds of the invention are known substances and are described in the literature at Gazz.Chim.Ital., 94, (1964), p 936.
SUMMARY OF THE INVENTION
The present invention provides a new class of 8β-pyrimidino-aminomethyl-10 α-ergoline and 10 α-methoxyergoline derivatives of the formula (I): ##SPC1##
wherein R is hydrogen or methyl; R 1 and R 2 are independently selected from the group consisting of hydrogen, alkyl groups having 1 to 6 carbon atoms, methoxy and phenyl; R 3 is hydrogen, halogen, an alkyl group having 1 to 6 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, phenyl, cyano, nitro, amino, an acylamino group having 1 to 3 carbon atoms, a carboxamido group having 1 to 3 carbon atoms or a carbalkoxy group having 1 to 3 carbon atoms; and R 4 is hydrogen or methoxy.
These compounds of formula (I) are prepared by a process having as its starting materials the known compounds dihydrolysergamine and 1-methyl-dihydrolysergamine wherein the formation of the intermediate 8β -guanidinomethyl derivative of 6-methyl- and 1,6-dimethyl-10 α-ergoline occurs according to the reaction: ##SPC2##
Wherein R, R 1 , R 2 , R 3 and R 4 are as defined above. The starting materials, dihydrolysergamine and 1-methyl-dihydrolysergamine (II) are described in the literature (Gazz.Chim.Ital., 94 (1964), p 936).
The intermediate 6-methyl- or 1,6-dimethyl-8β-guanidinomethyl-10 α-ergoline of formula III is obtained by reacting compound II with a compound capable of transforming the amino group into a guanidino group such as, for example, cyanamide, 1-guanidyl-3,5-dimethyl-pyrazole, an S-alkylisothiourea, wherein the alkyl group has 1-4 carbon atoms, and is preferably, ethyl, an O-alkylisourea, wherein the alkyl group has 1-4 carbon atoms, and is preferably, ethyl, or salts thereof.
This reaction is effected in an organic solvent such as a lower alkanol, preferably, ethanol at an elevated temperature, preferably at the boiling temperature of the solvent, i.e., about 50°-80°C. If the reactant employed is in the form of a salt, the corresponding salt of the 8β-guanidino-methyl derivative thus obtained, is thereafter transformed into the free base by treating with alkali in a conventional manner.
The 8β-guanidinomethyl derivative of the formula III is then condensed with an 8β-dicarbonyl compound of the formula:
R.sub.1 --CO--CH(R.sub.3)--CO--R.sub.2
wherein R 1 , R 2 and R 3 are as defined above. This reaction is effected in the presence of an organic solvent, such as a lower alkanol, for example, methanol, ethanol, propanol, butanol, etc. at a temperature between 10° and 150°C, over a period of 1 hour to 6 days.
The compounds of the invention can also be prepared by an alternative process. According to this alternative process, an ergoline compound of formula: ##SPC3##
is condensed, in an aprotic solvent with an anion of the structure: ##SPC4##
wherein R, R 1 , R 2 , R 3 and R 4 are as defined above, and X is selected from the group consisting of chlorine, bromine, mesyl or tosyl radical.
This anion is obtained by reacting the corresponding 2-aminopyrimidine with an organometallic compound, such as butyllithium, or a strong base such as sodium hydride, potassium hydride, sodium amide or potassium amide.
The pyrimidine anion is prepared directly in the reaction mixture in situ according to the following: ##SPC5##
wherein A is the strong base and by using dimethylformamide or liquid ammonia as a solvent. Which strong base is used is determined according to the nature of the group attached to the 5-position of the pyrimidine ring. If an electron attracting group is present in the 5-position (nitro or cyano group), sodium or potassium hydride is preferred; if an electron donor group (methyl) is attached to position 5, sodium or potassium amide will be used.
When this reaction is complete, the ergoline derivative, dissolved in an aprotic solvent, such as dimethylformamide or dimethylsulfoxide, is added and the mixture is heated to a temperature between 50° and 110°C for a period of from 30 minutes to 5 hours.
The obtained 8β-pyrimidino-aminomethyl derivative (I) is isolated and purified by crystallization or chromatography according to known techniques such as column chromatography.
The compounds of the present invention have a high and prolonged adrenolytic activity and a low toxicity and are therefore useful in therapy. This adrenolytic activity was tested on several of the present compounds in vitro in comparison with dihydroergotamine on isolated guinea pig seminal vescicle suspended in a physiological solution.
Table 1 reports the values of concentrations, in μg/ml., which are able to produce a 50% inhibition (IC 50 ) of the spasmogen effect caused by adrenaline. In the Table, several of the present compounds are compared with dihydroergotamine and it can be seen from these data that the compounds of the invention are at least twice as effective as dihydroergotamine and in one case, one hundred fifty times as effective as dihydroergotamine.
TABLE I______________________________________ TC.sub.50Compound μc/ml______________________________________1,6-dimethyl-8β-(5-nitro-2-pyrimidino-aminomethyl)-10α-ergoline 0.0071,6-dimethyl-8β-(2-pyrimidino-aminomethyl)-10α-meth-oxyergoline 0.0051,6-dimethyl-8β-(5-nitro-2-pyrimidino-aminomethyl)-10α-methoxyergoline 0.0011,6-dimethyl-8β-(5-methyl-2-pyrimidino-aminomethyl)-10α-methoxyergoline 0.0011,6-dimethyl-8β-(5-cyano-2-pyrimidino-aminomethyl)-10α-methoxyergoline 0.00011,6-dimethyl-8β-(5-cyano-2-pyrimidino-aminomethyl)-10α-ergoline 0.0051,6-dimethyl-8β-(5-bromo-2-pyrimidino-aminomethyl)-10α-methoxyergoline 0.0051,6-dimethyl-8β-(5-methyl-2-pyrimidino-aminomethyl)-10α-ergolinedihydroergotamine 0.015______________________________________
The adrenolytic activity of the compounds of the invention was also determined in vivo on the rat in comparison with dihydroergotamine and nicergoline. Table 2 reports the doses in mg/kg (ID 50 ) able to reduce by 50% the lethal effects caused by adrenaline after oral (os) and intravenous (i.v.) administration of these compounds as compared with dihydroergotamine and with nicergoline, i.e., 1,6-dimethyl-8 -(5'-bromonicotinoyloxymethyl)-10 -methoxyergoline (Br. J. Pharmac, 34, 700, 1968).
TABLE 2______________________________________Compound ID.sub.50 mg/kg (i.v.) (os)______________________________________1,6-dimethyl-8β-(4,6-dimethyl-2-pyrimidino-aminomethyl) 10α-ergoline -- 1.251,6-dimethyl-8β-(5-nitro-2-pyrimidino-amino-methyl) 10α-ergoline 0.09 0.041,6-dimethyl-8β-(5-amino-2-pyrimidino-amino-methyl)-10α-ergoline 0.18 0.51,6-dimethyl-8β-(5-chloro-2-pyrimidino-amino-methyl)-10α-ergoline -- 0.141,6-dimethyl-8β-(2-pyrimidino-aminomethyl)-10α-methoxyergoline 0.2 11,6-dimethyl-8β-(5-nitro-2-pyrimidino-amino-methyl)-10α-methoxyergoline 0.2 <0.11,6-dimethyl-8β-(5-methyl-2-pyrimidino-amino-methyl)-10α-methoxyergoline 0.1 0.11,6-dimethyl-8β-(5-cyano-2-pyrimidino-amino-methyl)-10α-methoxyergoline 0.015 0.21,6-dimethyl-8β-(5-cyano-2-pyrimidino-amino-methyl)-10α-ergoline 0.05 0.051,6-dimethyl-8β-(5-bromo-2-pyrimidino-amino-methyl)-10α-methoxyergoline 0.08 0.321,6-dimethyl-8β-(5-methyl-2-pyrimidino-amino-methyl)-10α-ergoline 0.15 0.1dihydroergotamine 0.08 15.01,6-dimethyl-8β-(5'-bromonicotinoyloxymethyl-10α-methoxyergoline (nicergoline) 0.024 7.0______________________________________
Some of the compounds reported in Table 2 have a long lasting effect of up to 24 hours as shown by the data contained in Table 3.
TABLE 3
Percentage of animals protected against lethal adrenaline dose
TABLE 3__________________________________________________________________________Percentage of animals protected against lethal adrenaline__________________________________________________________________________dose Dose Hours after administrationCompound mg/Kg of the compound (% survivors) (peros) 0.5 1 2 4 8 16 24__________________________________________________________________________1,6-dimethyl-8β-(4,6-dimethyl- 2.5 -- 80 60 30 -- -- --2-pyrimidino-aminomethyl-) 10α- 5 -- 100 80 50 20 -- --ergoline 10 -- 100 100 60 -- -- --1,6-dimethyl-8β-(5-nitro-2- 0.1 50 90 60 70 60 10 --pyrimidino-aminomethyl)-10α- 0.5 100 100 100 90 80 30 20ergoline1,6-dimethyl-8β-(5-cyano-2- 0.2 -- -- 100 90 -- -- --pyrimidino-aminomethyl)-10α- 0.5 -- 80 90 80 80 -- --methoxyergoline1,6-dimethyl-8β-(5-nitro-2- 0.1 -- 70 80 -- -- -- --pyrimidino-aminomethyl)-10α 0.5 100 -- 100 90 40 -- --methoxyergollne__________________________________________________________________________
Furthermore, nicergoline is known to be rapidly metabolized in the presence of blood in vitro (Arcamone et al. Bioch. Pharmac. 21, 2205, 1972) while the compounds of the present invention, under the same conditions, remain practically unaltered. This greater stability was confirmed by the determination of the submaximal inhibiting dosage which protects 80% of the tested animals (rats) against a single dose of 200 mg/Kg of body weight of adrenalin injected 8 hours after administration of the tested compounds according to the invention.
These data are reported in Table 4, where, for comparative purposes, the corresponding data for dihydroergotamine and nicergoline are given
TABLE 4______________________________________ ID in mg/kg body weight; perosCompound in rats after 8 hours______________________________________1,6-dimethyl-8β-(5-nitro-2-pyrimidino- 0.5aminomethyl)-10α-ergoline1,6-dimethyl)8β-(5-amino-2-pyrimidino- 1aminomethyl)-10α-ergoline1,6-dimethyl)8β-(5-chloro-2-pyrimidino- 1aminomethyl)-10α-ergoline1,6-dimethyl-8β-(5-cyano-2-pyrimidino- 0.5aminomethyl)-10αmethoxyergolinedihydroergotamine >201,6-dimethyl-8β-(5'-bromonicotinoyloxy- >20methyl) 10α-methoxyergoline (nicergoline)______________________________________
The low toxicity of the compounds of the invention is demonstrated by the data in Table 5 which sets forth the LD 50 values, both per os and i.v. in rats for several of the compounds of the invention.
TABLE 5______________________________________ LD.sub.50Compounds mg/kg i.v. os______________________________________1,6-dimethyl-8β-(2-pyrimidino-aminomethyl)- 25 25010α-methoxyergoline1,6-dimethyl-8β-(5-nitro-2-pyrimidino-amino- 28 200methyl) 10α-methoxyergoline1,6-dimethyl-8β(5-methyl-2-pyrimidino-amino- 18 --methyl-10α-methoxyergoline1,6-dimethyl-8β-(5-cyano-2-pyrimidino-amino- 38 160methyl)-10α-methoxyergoline1,6-dimethyl-8β-(5-cyano-2-pyrimidino-amino- 25 35methyl)- 10α-ergoline1,6-dimethyl-8β-(5-bromo-2-pyrimidino-amino- 50 230methyl)-10α-methoxyergoline1,6-dimethyl-8β-(5-methyl-2-pyrimidino-amino- 35 140methyl) 10α-ergoline1,6-dimethyl-8β-(5-amino-2-pyrimidino-amino- 18 140methyl)-10α-ergoline______________________________________
In addition, it has also been found that some of the compounds according to the invention display an unexpected hypotensive, analgesic, antiserotonin and sedative activity. The hypotensive and analgesic data for some of the compounds are given in Table 6.
The hypotensive activity was tested on the hypertensive rat; the reported data being the dose, expressed in mg/kg per os, which causes a pressure drop of about 30-40 mmHg.
The analgesic activity was evaluated by means of the hot plate test and the writhing test, the data being given in comparison with morphine and D-propoxyphene.
TABLE 6__________________________________________________________________________ Hypotensive Analgesic Activity Activity Hot plate Writhing Active Dose mor- D-propo- mor- D-propo-Compounds mg/kg per os phine xyphene phine xyphene__________________________________________________________________________1,6-dimethyl-8β-(2-pyrimidino-aminometh-yl)-10α-ergoline 5-10 1 1 0.5 51,6-dimethyl-8β-(5-methyl-2-pyrimidino-aminomethyl)-10α-ergoline 5-10 1 5 0.5 51,6-dimethyl-8β(5-cyano-2-pyrimidino-aminommethyl)-10α-methoxyergoline 1-2.5 -- -- 0.2 11,6-dimethyl-8β-(5-nitro-2-pyrimidino-aminomethyl)-10α-methoxyergoline 1-2.5 -- -- -- --1,6-dimethyl-8β-(5-cyano-2-pyrimidino-aminomethyl)-10α-ergoline 2.5-5 -- -- -- --__________________________________________________________________________
In the hot plate and writhing tests, the comparison compounds morphine and D-propoxyphene have been arbitrarily assigned the value of 1. Thus, in the hot plate test, the compound 1,6-dimethyl-8β-(2-pyrimidino-aminomethyl)-10α-ergoline has the same activity as both morphine and D-propoxyphene, while in the writhing test that compound has 1/2 the activity of morphine and 5 times the activity of D-propoxyphene.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
The following examples are given to illustrate the invention without, however, limiting it.
EXAMPLE 1
1,6-dimethyl-8β-(5-nitro-2-pyrimidino-aminomethyl)-10α -ergoline
A solution of 5 g of 1-methyl-dihydrolysergamine and 4 g of 1-guanyl-3,5-dimethylpyrazole nitrate in 200 ml of ethanol was refluxed for 7 hours. The solution was concentrated until crystallization began and 4 g of 1,6-dimethyl-8β-guandinomethyl-10β -ergoline nitrate melting at 242°-244° C were obtained. To a solution of 3 g of this product in 120 ml of methanol, 4.8 g of the sodium salt of nitromalondialdehyde (Organic Synthesis 27, 60) and 0.1 ml of piperidine were added.
The solution was stirred for 8 hours. The resulting precipitate was then collected with 2.5 g of 1,6-dimethyl-8β-(5-nitro-2-pyrimidino-aminomethyl)-10α -ergoline, melting at 204°-206°C, being obtained.
EXAMPLE 2
1,6-dimethyl-8β(4,6-dimethyl-2-pyrimidino-aminomethyl)-10α -ergoline
A solution of 4 g of 1-methyl-dihydrolysergamine in 150 ml of ethanol was refluxed for 4 hours with 2 equivalents of cyanamide. It was neutralized with nitric acid and concentrated until crystallization began. 2 g of 1,6-dimethyl-8β-guanidinomethyl- 10α -ergoline nitrate melting at 242°-244°C were separated.
The corresponding free base was obtained by the addition of an equivalent of sodium methylate to 1,6-dimethyl-8β-guanidinomethyl-10α -ergoline nitrate. 0.9 g of 1,6-dimethyl-8β -guanidinomethyl-10 α-ergoline base in 20 ml of acetylacetone was dissolved and the solution was refluxed for 3 hours. The residue was evaporated and chromatographed on an alumina column using chloroform as the eluant. This solvent was used in all examples in which column chromatography was used to purify the product. 0.6 g of 1,6-dimethyl-8β-(4,6-dimethyl-2-pyrimidinoaminomethyl)-10α-ergoline melting at 129°-131° was obtained.
EXAMPLE 3
1,6-dimethyl-8β-(4-methyl-6-phenyl-2-pyrimidino-aminomethyl)-10 α-ergoline
1 g of 1,6-dimethyl-8β-guanidinomethyl-10α -ergoline base and 5 g of benzoylacetone were heated to 80°C for 65 hours. The reaction mixture was concentrated in vacuo and the residue chromotographed on an alumina column. 0.5 g of 1,6-dimethyl-8β-(4-methyl-6-phenyl-2-pyrimidino-aminomethyl)-10.alpha. -ergoline, melting at 192°-194°C, was obtained.
EXAMPLE 4
1,6-dimethyl-8β-(5-chloro-2-pyrimidino-aminomethyl)-10α -ergoline
2 g of 1,6-dimethyl-8β-guanidinomethyl-10α -ergoline base and 2 equivalents of chloromalondiadehyde (J.Chem.Soc. 1949, p. 1550) were heated in butanol at 110°C for 4 hours. The reaction mixture was concentrated in vacuo and the residue was chromatographed on an alumina column. 1.2 g of 1,6-dimethyl-8β-(5-chloro-2-pyrimidino-aminomethyl)-10 α-ergoline, melting at 190°-192°C, were obtained.
EXAMPLE 5
1,6-dimethyl-8β (5-nitro-2-pyrimidino-aminomethyl)-10α -ergoline
One equivalent of 1-methyl-dihydrolysergamine was reacted with one equivalent of S-ethylisothiourea hydrochloride in 80% ethanol at 50°C for 3 hours. The 1,6-dimethyl-8β-guanidinomethyl-10α -ergoline hydrochloride thus obtained was condensed with the sodium salt of nitromalondialdehyde in a 1:1 molar ratio in the same manner as described in Example 1 to obtain the product in a yield of 45%; m.p. 204°-206°C.
EXAMPLE 6
1,6-dimethyl-8β -(5-nitro-2-pyrimidino-aminomethyl)-10α -ergoline
By operating in accordance with the procedures described in Example 5, but using O-ethylisourea hydrochloride in lieu of S-ethylisothiourea, 1,6-dimethyl-8β-guanidinomethyl-10α -ergoline hydrochloride was obtained in a yeild of 49%, m.p. 275°-278°C.
EXAMPLE 7
1,6-dimethyl-8β-(5-bromo-2-pyrimidino-aminomethyl)-10α -ergoline
By operating in accordance with the procedures described in Example 1, using bromomalondialdehyde (J,Org.Chem.28, 1963, p. 3243), 1,6-dimethyl-8β -(5-bromo-2-pyrimidino-aminomethyl)-10α -ergoline melting at 186°C, was obtained in 60% yield.
EXAMPLE 8
6-methyl-8β-(5-nitro-2-pyrimidino-aminomethyl)-10α -ergoline
A solution of dihydrolysergamine and 1-guanyl-3,5-dimethylpyrazole nitrate in ethanol was refluxed for 7 hours. By crystallization from the reaction mixture, 6-methyl-8β-guanidinomethyl-10 α-ergoline nitrate melting at 235°-237°C was obtained. This product was reacted with nitromalondialdehyde as described in Example 1 to obtain 6-methyl-8β-(5-nitro-2-pyrimidino-aminomethyl)-10α -ergoline in 61% yield; m.p. 258°-260°C.
By operating in accordance with the procedures described in Example 1, the following compounds were prepared:
1,6-dimethyl-8β-(2-pyrimidino-aminomethyl)-10α -ergoline; m.p. 164°-166°C
1,6-dimethyl-8β-(5-phenyl-2-pyrimidino-aminomethyl)-10α -ergoline; m.p. 185°C
1,6-dimethyl-8β-(5-methoxy-2-pyrimidino-aminomethyl)-10α -ergoline; m.p. 171°C
1,6-dimethyl-8β-(5-cyano-2-pyrimidino-aminomethyl)-10α -ergoline; m.p. 210°C.
EXAMPLE 9
1,6-dimethyl-8β-(5-nitro-2-pyrimidino-aminomethyl)-10α -methoxyergoline
0.5 g of 2-amino-5-nitropyrimidine was added under stirring and a nitrogen atmosphere to a suspension of 0.168 g of sodium hydride (50% dispersion in mineral oil) in 20 ml of dimethylforamide. When the evaluation of hydrogen ceased, a solution of 1.1 g of 1,6-dimethyl-8β-chloromethyl-10α -methoxyergoline dissolved in 10 ml of dimethylformamide was added and the mixture was heated to 100°C for 4 hours. At the end of the reaction, the dimethylformamide was evaporated off, the mineral oil was removed by treating with n-pentane and the residue was dissolved in boiling ethyl ether and filtered.
The ether was evaporated off and the residue was crystallized from acetone to obtain 0.800 g of the product melting at 160°-162°C.
EXAMPLE 10
1,6-dimethyl-8β-(5-methyl-2-pyrimidino-aminomethyl)-10α -methoxyergoline
To a solution of 0.085 g of sodium amide in 100 ml of liquid ammonia, 0.237 g of 2-amino-5-methylpyrimidine was added with stirring. The ammonia was then slowly evaporated and a solution of 0.554 g of 1,6-dimethyl-8β-chloromethyl-10α -methoxyergoline in 40 ml of anhydrous dimethylsulfoxide was added thereto. The mixture was stirred and heated to 60°C for 30 minutes, after which the dimethylsulfoxide was evaporated off and the residue dissolved in water and chloroform.
The chloroform solution was evaporated and the residue chromatographed on an alumina column. 0.200 g of the product melting at 195°-197°C was obtained.
EXAMPLE 11
1,6-dimethyl-8β -(5-bromo-2-pyrimidino-aminomethyl)-10α -methoxyergoline
By operating in accordance with the procedure described in Example 9, but using 2-amino-5-bromo-pyrimidine, there was obtained 1,6-dimethyl-8β-(5-bromo-2-pyrimidino-aminomethyl)-10α -methoxyergoline melting at 196°-198°C in 61% yield.
EXAMPLE 12
1,6-dimethyl-8β -(5-cyano-2-pyrimidino-aminomethyl)-10α methoxyergoline
By operating in accordance with the procedure described in Example 9 but employing 2-amino-5-cyano-pyrimidine, there was obtained 1,6-dimethyl-8β -(5-cyano-2-pyrimidino-aminomethyl)-10α -methoxyergoline melting at 136°-138°C in 68% yield.
EXAMPLE 13
1,6-dimethyl-8β -(5-carbethoxy-2-pyrimidino-aminomethyl)-10α -methoxyergoline
By operating in accordance with the procedure described in Example 9, but using 2-amino-5-carbethoxy-pyrimidine, there was obtained 1,6-dimethyl-8β -(5-carbethoxy-5-pyrimidino-aminomethyl)-10α -methoxyergoline melting at 216°-218°C in 48% yield.
EXAMPLE 14
1,6-dimethyl-8β -(2-pyrimidino-aminomethyl)-10α -methoxyergoline
By operating in accordance with the procedure described in Example 10, using 2-aminopyrimidine, there was obtained 1,6-dimethyl-8β-(2-pyrimidino-aminomethyl)-10α -methoxyergoline melting at 228°-230°C in 35% yield.
EXAMPLE 15
1,6-dimethyl-8β -(5-methoxy-2-pyrimidino-aminomethyl)10α -methoxyergoline
By operating in accordance with the procedure described in Example 10, but using 2-amino-5-methoxy-pyrimidine, there was obtained 1,6-dimethyl-8β-(5-methoxy-2-pyrimidino-aminomethyl)-10 α-methoxyergoline melting at 172°-174°C in 38% yield.
EXAMPLE 16
1,6-dimethyl-8β-(5-methyl-2-pyrimidino-aminomethyl)-10 α-ergoline
By operating in accordance with the procedure described in Example 10, but using 2-amino-5-methylpyrimidine and 1,6-dimethyl-8β-chloromethyl-10 α-ergoline, there was obtained 1,6-dimethyl-8β-(5-methyl-2-pyrimidino-aminomethyl)-10α -ergoline melting at 190°-192°C in 63% yield.
Of course, by operating in accordance with the procedures described above, other compounds falling within the scope of the invention, such as 1,6-dimethyl-8β-(5-dimethylamino-2-pyrimidino-aminomethyl)-10α-ergoline and 1,6-dimethyl-8β-(5-acetylamino-2-pyrimidino-aminomethyl)-10α-ergoline can also be prepared.
Variations can, of course, be made without departing from the spirit and scope of the invention.
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Novel 8β-pyrimidino-aminomethyl-10α-ergoline and 10α-methoxyergoline derivatives which possess a high and prolonged adrenolytic activity and a low toxicity, and some of which also possess hypotensive and analgesic activity are prepared by reacting a pyrimidine anion with an ergoline derivative in an aprotic solvent.
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BACKGROUND
Technical Field
The present disclosure relates to a process for manufacturing MEMS (Micro-Electro-Mechanical System) devices having two buried cavities and to the micro-electro-mechanical device.
Description of the Related Art
As is known, sensors including micromechanical structures made, at least in part, of semiconductor materials employing MEMS technology are increasingly widely used, due to their advantageous characteristics of small dimensions, low manufacturing costs, and flexibility.
A MEMS sensor generally comprises a micromechanical sensing structure, which transduces a physical or mechanical quantity to be detected into an electrical quantity (for example, correlated to a capacitive variation); and an electronic reading circuit, usually formed as an ASIC (Application-Specific Integrated Circuit), which carries out processing operations (i.e., amplification and filtering) of the electrical quantity and supplies an electrical output signal, either analog (for example, a voltage) or digital (for example a PDM—Pulse Density Modulation—signal). The electrical signal, possibly further processed by an electronic interface circuit, is then made available to an external electronic system, for example a microprocessor control circuit of an electronic apparatus incorporating the sensor.
MEMS sensors comprise, for example, sensors for detecting physical quantities, such as inertial sensors, which detect acceleration or angular velocity data; sensors of derived signals, such as quaternions (data representing rotations and directions in three-dimensional space), gravity signals, etc.; motion sensors, such as step counters, running sensors, uphill sensors, etc.; and environmental signals, which detect quantities such as pressure, temperature, and humidity.
To sense the physical/mechanical quantity, MEMS sensors of the considered type comprise a membrane or a mass formed in or on a semiconductor chip and suspended over a first cavity. The membrane may face the external environment or be in communication therewith via a fluidic path.
U.S. Pat. No. 9,233,834 describes, for example, a MEMS device wherein a sensitive part of the device that forms the membrane is separated from the rest of the chip and supported by springs. The springs decouple the sensitive part from the rest of the chip and absorb the package stress, without transferring it to the sensitive part. In this device, the sensitive part is housed within or faces a second cavity that enables a limited movement of the sensitive part with respect to the rest of the chip.
In practice, the device has two cavities, where a first cavity defines the membrane and a second cavity enables decoupling of the sensitive part of the device from the rest. In the known device, to obtain the two cavities, two semiconductor wafers are used, which are bonded together. If the device is provided with a cap, this is formed in a third wafer, which is also bonded, as discussed hereinafter with reference to FIGS. 1 and 2 .
FIG. 1 shows in a simplified way a MEMS sensor 1 formed in a chip 10 of semiconductor material, such as silicon. A cap 11 is fixed to a first face 10 A of the chip 10 , and a closing region 12 is fixed to a second face 10 B of the chip 10 via spacers 26 .
The chip 10 comprises a suspended region 13 separated from a peripheral portion 18 of the chip 10 through a trench 14 . Elastic elements (also referred to as springs 15 ) support the sensitive region 13 and connect it mechanically to the peripheral portion 18 . The sensitive region 13 houses a buried cavity 16 delimiting a membrane 19 . The term “buried cavity” herein refers to an empty area (or an area filled with gas) within a semiconductor material body or chip, which extends at a distance from the two main faces of the body, being separated from these faces by portions of semiconductor and/or dielectric material.
A second cavity 21 extends underneath the sensitive region 13 . The sensitive region 13 is provided with a stem 20 (also referred to as Z stopper) extending in the second cavity 21 and limiting oscillation of the sensitive region 13 in the event of impact or stresses that might damage the springs 15 .
The cap 11 covers here at the top the entire first face 10 A of the chip 10 and protects the latter from the external environment. The cap 11 is fixed via bonding regions 22 , for example of metal such as gold, tin, or copper, or polymeric material or a glass material (glass-frit), fixed to the peripheral portion 18 and is thus spaced apart by a gap 23 from the first face 10 A due to the thickness of the bonding regions 22 . Further, the cap 11 has a through hole 24 , which fluidically connects the membrane 19 to the environment that surrounds the chip 10 .
The closing region 12 has a protection function during handling of the MEMS sensor 1 (for example, during transport to an assembly system). In general, the closing region 12 is constituted by a second chip housing electronic components, such as an ASIC, but may be constituted by another support, such as a printed-circuit board, or the like. Generally, the closing region 12 has a containment trench 17 , to prevent material of the bonding regions 26 from reaching the mobile parts, limiting movement thereof in an undesired way.
By virtue of the second cavity 21 , the sensitive region 13 bearing the sensitive part of the MEMS sensor (membrane 19 ) is free to move within certain limits in a vertical direction (perpendicular to the main extension plane of the chip 10 and thus to the faces 10 A, 10 B thereof) and is not affected by stress during manufacturing, in particular during packaging, in so far as the sensitive region 13 is mechanically decoupled from the peripheral portion.
The device of FIGS. 1 and 2 is formed by bonding three wafers together. In particular, initially ( FIG. 3A ) a first wafer 350 of monocrystalline silicon is processed for forming the buried cavities 16 delimiting the membranes 19 at the bottom. Formation of the buried cavities 16 may take place in various ways, for example as described in U.S. Pat. No. 8,173,513. Further, on a first face 350 A of the first wafer 350 a gold layer is deposited so as to form first bonding and electrical-connection structures 351 . In addition, the first wafer 350 is etched from the front using a silicon etching for laterally defining the trenches 14 and the springs 15 .
In parallel, before or after ( FIG. 3B ), a second wafer 400 of monocrystalline silicon is provided with second bonding and electrical-connection structures 401 having a shape and dimensions that are congruent with those of the first bonding and electrical-connection structures 351 . Next, using a resist mask, a deep silicon etch is carried out to form holes 403 and trenches 404 . Etching is prolonged so that both the holes 403 and the trenches 404 have a greater depth than the thickness intended for the cap 11 ( FIG. 1 ).
Then ( FIG. 3C ), the second wafer 400 is flipped over and fixed to the first wafer 350 via a wafer-to-wafer bonding process of a known type, to obtain a composite wafer 500 .
Next ( FIG. 3D ), the first wafer 350 is thinned out from the back, to form the second cavities 21 and the stems 20 , and is etched once again from the back, to release the suspended regions 13 and the springs 15 . In addition, the second wafer 400 is thinned out until the bottom of the holes 403 and of the trenches 404 is reached.
After bonding a third wafer 410 and dicing the composite wafer 500 of FIG. 3D , the MEMS sensor 1 of FIG. 1 is thus obtained.
Consequently, in the process described, the MEMS device 1 is obtained by bonding three different wafers.
Thus, its thickness is considerable. Further, the process is rather complex in so far as it specifies bonding of three wafers.
BRIEF SUMMARY
One or more embodiments are directed to a MEMS device having two cavities and the manufacturing process thereof.
According to one embodiment a micro-electro-mechanical device is provided. The micro-electro-mechanical device comprises a monolithic body of semiconductor material having a first face and a second face. A first buried cavity is in the monolithic body and a sensitive region is in the monolithic body facing the first buried cavity. The device comprises a movable element over a second cavity that faces the first buried cavity. The device comprises a decoupling trench extending from the first face of the monolithic body as far as the first buried cavity. The decoupling trench separates the sensitive region from a peripheral portion of the monolithic body.
In at least one embodiment, the second cavity is buried in the sensitive region and the movable element is a membrane in the sensitive region and arranged between the second cavity and the first face. In another embodiment, the movable element and second cavity are spaced apart from the first face of the monolithic body and the movable element is supported by a structural element that is coupled to the first face of the monolithic body.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS
For a better understanding of the present disclosure, preferred embodiments thereof are now described, purely by way of non-limiting example, with reference to the attached drawings, wherein:
FIGS. 1 and 2 are, respectively, a cross-section and a top view of a known MEMS sensor;
FIGS. 3A-3D are cross-sections of successive manufacturing steps of the MEMS sensor of FIG. 1 ;
FIGS. 4A-4F show cross-sections of successive steps of an embodiment of the present manufacturing process;
FIG. 5 is a top view of a detail of the wafer formed in step 4 E of the present process;
FIGS. 6A-6D are cross-sections of successive steps of another embodiment of the present manufacturing process;
FIG. 7 is a top view of a detail of the wafer formed in step 6 B of the present process;
FIG. 8 is a top view of a detail of the wafer formed in step 6 C of the present process;
FIG. 9 is a cross-section of a different embodiment of the present MEMS device; and
FIG. 10 shows an apparatus using the present MEMS device.
DETAILED DESCRIPTION
The present manufacturing process will be described hereinafter with reference to manufacturing a single sensitive structure, it being understood that it is replicated a number of times in a wafer, prior to dicing the wafer, in a per se known manner to the person skilled of the art.
Initially ( FIG. 4A ), a buried cavity is formed in an initial wafer 100 of semiconductor material. For example, to this end, the manufacturing process described in U.S. Pat. No. 8,173,513 and summarized briefly hereinafter may be used.
In detail, on the initial wafer 100 , a resist mask 101 is formed having openings arranged according to a honeycomb configuration. Using the mask 101 , the initial wafer 100 is anisotropically etched for forming a plurality of trenches 102 , communicating with each other and delimiting a plurality of silicon columns 103 .
With reference to FIG. 4B , the mask 101 is removed and an epitaxial growth is carried out in reducing environment. Consequently, an epitaxial layer, for example of an N type with a thickness of 30 μm, grows above the columns 103 , closing the trenches 102 at the top and forming a first intermediate wafer 200 .
A thermal annealing is carried out, for example for 30 minutes at 1190° C., preferably in hydrogen atmosphere, or, alternatively, in nitrogen atmosphere.
As discussed in the patents referenced above, annealing causes migration of the silicon atoms, which tend to move into a lower-energy position. Consequently, and also by virtue of the short distance between the columns 103 , the silicon atoms of the latter migrate completely, and a first buried cavity 106 is formed. A thin silicon layer remains above the first buried cavity 106 and is formed in part by epitaxially grown silicon atoms and in part by migrated silicon atoms and forms a monosilicon closing layer 105 .
In the embodiment shown ( FIG. 4C ), another epitaxial growth is carried out, of an N type or else a P type and of thickness of a few tens of micrometers, for example 50 μm, starting from the closing layer 105 . A second intermediate wafer 201 is thus formed, which includes a first thick monosilicon region 108 that overlies the first buried cavity 106 .
With reference to FIG. 4D , a second cavity 109 is formed in the first thick region 108 , for example repeating the manufacturing process described in U.S. Pat. No. 8,173,513 (see also FIGS. 4A and 4B ). In this way, a sensor wafer 107 is formed having a first and a second face 107 A, 107 B and, above the first cavity 106 , a second thick region 114 . The second thick region 114 accommodates a second cavity 109 and a membrane 110 , which is delimited at the bottom of the second cavity 109 and faces the first face 107 A. The second thick region 114 has, for example, a thickness of approximately 50 μm, and the membrane 110 has, for example, a thickness of approximately 10 μm.
If the application so specifies, electronic components 121 may be provided in the membrane 110 , for example piezoresistors, via diffusion or implantation of dopant ion species, here of a P type, in a known manner and not shown. Further, in a per se known manner, electrical interconnections (not shown) may be provided on the first face 107 A of the sensor wafer 107 .
With reference to FIG. 4E , using a masking layer (not shown), a deep silicon etch is carried out through the second thick region 114 until the first cavity 106 is reached. A trench 111 is thus formed, external to and surrounding the second cavity 109 . In particular, in the embodiment shown, the trench 111 has the shape of a square spiral. In this way, as may be seen in the top view of FIG. 5 , the trench 111 is formed by five sides delimiting a sensitive portion 112 , and an arm or spring 113 connecting the sensitive portion 112 to the rest of the sensor wafer 107 (peripheral portion 104 and base 119 ).
A cap wafer 115 is fixed to the first face 107 A of the sensor wafer 107 . To this end, for example, bonding regions 116 , for instance, of metal such as gold, tin, or copper, or of polymeric material or a glass based material (glass-frit) may be applied previously to the cap wafer 115 and/or to the sensor wafer 107 . In this way, it is possible to electrically connect the electronic components 121 , integrated in the second wafer 107 , with conductive structures (not illustrated) in or on the cap wafer 115 . The bonding regions 116 further form spacers between the first face 107 A of the sensor wafer 107 and the cap wafer 115 , thus delimiting a gap 117 .
In the embodiment shown, the cap wafer 115 has a through hole 118 that enables fluidic connection between the gap 117 and the external environment and detection, by the membrane 110 , of the external pressure.
The cap wafer 115 may further be provided with holes (not shown) for bonding wires (not shown). Alternatively, in a way not shown either, through-silicon vias (not shown) may be provided in the peripheral portion 104 of the sensor wafer 107 for electrical connection of the electrical components 121 with the second face 107 B of the sensor wafer 107 .
After dicing the sensor wafer 107 into a plurality of MEMS devices 120 , each of them may be fixed to a support (not shown), for example an ASIC. Alternatively, the sensor wafer 107 may be fixed to a further wafer, prior to dicing, or to a printed-circuit board, in a way not shown.
According to a different embodiment, the second cavity may be formed via removal of a sacrificial layer.
In this case, the manufacturing process may comprise the same initial steps as those described above with reference to FIGS. 4A-4C .
Thus, starting from the structure of FIG. 4C , where the first cavity 106 has already been formed in the second intermediate wafer 201 , a sacrificial region 130 is formed on the first thick region 108 . The sacrificial region 130 is formed, for example, by depositing a sacrificial layer (for instance, of silicon oxide) and its definition via known photolithographic techniques ( FIG. 6A ). A structural layer 131 is deposited over the sacrificial region 130 , for example a polycrystalline silicon layer grown by CVD, to form a sensor wafer 210 having a first, non-planar, face 210 A, comprising a projecting area, corresponding to the structural layer 131 , and a lowered area, corresponding to the exposed portion of the first thick region 108 .
With reference to FIG. 6B , the structural layer 131 is etched to define a micro-electro-mechanical structure of an inertial type, for example an accelerometer. In this case, as may be seen in the top view of FIG. 7 , a suspended mass or platform 132 , springs 133 , connecting the platform 132 to the rest of the structural layer 131 , and mobile and fixed electrodes 134 , represented only schematically in FIG. 7 , are defined.
The sacrificial region 130 is removed by etching the sacrificial material, for example in hydrofluoric acid for releasing the platform 132 and the mobile electrodes, thereby obtaining the structure of FIG. 6B , where a second cavity 125 extends underneath the platform 132 .
Subsequently or previously, for example using a dry film ( FIG. 6C ) and analogously to what described with reference to FIG. 4E , using a masking layer (not shown) a deep silicon etch is made through the first thick region 108 , outside the area of the structural layer 131 , and thus outside the platform 132 , until the first cavity 106 is reached. The trench 111 is thus formed, which, in top view (see FIG. 8 ) surrounds the second cavity 125 and the platform 132 . Also here, the trench 111 has the shape of a square spiral and comprises five sides delimiting a sensitive portion 135 , and an arm or spring 136 connecting the sensitive portion 135 to the rest of the sensor wafer 210 , hereinafter also indicated as peripheral portion 137 .
A cap wafer 140 is fixed to the first face 210 A of the sensor wafer 210 analogously to what described with reference to FIG. 4F . In this case, since the surface 210 A of the sensor wafer 210 is not planar and the platform 132 projects above the thick region 108 , the cap wafer 140 has a recess 141 facing the sensitive region 135 .
Also in this case, the cap wafer 140 may have holes (not shown) for passage of bonding wires, or, in a way not shown, through-silicon vias may be provided in the peripheral portion 137 .
The sensor wafer 210 is diced into a plurality of MEMS devices 143 , and, analogously to what already described, each of them may be bonded to a support or the sensor wafer 210 may be fixed to a further wafer, prior to dicing.
In a different embodiment ( FIG. 9 ), the cap is formed directly by an ASIC, and the hole for connection to the external environment is formed directly in the sensor wafer, instead of in the cap.
In the embodiment shown, the sensor wafer 107 of FIG. 4E is used. The base portion 119 of the sensor wafer 107 , underneath the first cavity 106 in the view of FIG. 4E , is here perforated by a deep silicon etch, analogous to the trench 111 etching. A connection hole 145 is thus obtained and connects the first cavity 106 to the external environment.
First stoppers 146 , for example of dielectric material, such as silicon oxide, or metal material or polysilicon or a stack of different material layers, deposited and defined on the first face 107 A, in a per se known manner, are further formed on the first face 107 A of the sensor wafer 107 .
Second stoppers 147 are formed on a face 150 A of an ASIC wafer 150 , in a position so as to face, at a distance, the first stoppers 146 .
Spacer elements 151 as well as mechanical and electronic connection elements 152 are formed on the ASIC wafer 150 or on the sensor wafer 107 .
The spacers 151 may be of materials including gold, copper, tin, glass-frit or polymers and may have a thickness of 5 μm.
The mechanical and electronic connection elements 152 may, for example, be formed by so-called “solder balls”, arranged at contact pads 153 A, 1536 formed on the first face 107 A of the sensor wafer 107 and a face 150 A of the ASIC wafer 150 .
The sensor wafer 107 and the ASIC wafer 150 are bonded together, with the first face 107 A of the sensor wafer and the face 150 A of the ASIC wafer 150 facing each other, thereby forming a composite wafer. Finally, the composite wafer is diced into a plurality of finished devices 160 .
As an alternative to the above, the connection hole 145 may be formed at the end of the process, prior to dicing the composite wafer.
In this way, between the two faces 107 A and 150 A a gap 154 is formed, the thickness thereof is defined by the spacer elements 151 , and the sensitive portion 112 may move in a limited way within the gap 154 or the first cavity 106 , and is thus decoupled from the peripheral portion 104 .
In addition, the membrane 110 is connected to the external environment through the trench 111 , the first cavity 106 , and the hole 145 , thus forming a fluidic path.
The mechanical and electronic connection elements 152 enable, in addition to bonding the sensor wafer 107 and the ASIC wafer 150 , their electrical connection.
As an alternative to the above, the sensor wafer 107 and/or the ASIC wafer 150 may be diced prior to bonding, in a per se known manner. Further, it is possible to form the cap and ASIC also starting from the structure of FIG. 6A , and thus with the second cavity 125 formed by removal of a sacrificial region.
FIG. 10 is a schematic representation of an electronic apparatus 170 using the MEMS device 120 , 143 , 160 .
The electronic apparatus 170 comprises, in addition to the MEMS device 120 , 143 , 160 , a microprocessor 174 , a memory block 175 , connected to the microprocessor 174 and an input/output interface 176 , also connected to the microprocessor 174 . Further, a speaker 178 may be present for generating a sound on an audio output (not shown) of the electronic apparatus 170 .
In particular, the electronic apparatus 170 is fixed to a supporting body 180 , for example formed by a printed circuit.
The electronic apparatus 170 is, for example, an apparatus for measuring blood pressure (sphygmomanometer), a household apparatus, a mobile communication device (a cellphone, a PDA—Personal Digital Assistant—, or a notebook) or an pressure measuring apparatus that may be used in the automotive sector or in the industrial field in general.
In this way, the devices 120 , 143 , 160 may be formed with a lower number of wafers as compared to the devices currently produced, since both the cavities (i.e., the first cavity 106 and the second cavity 109 or 125 ) are formed in a same monolithic substrate, without bonding two wafers together.
In this way, the manufacturing costs are considerably reduced. Further, it is possible to reduce the thickness of the finished device, for a same robustness. Finally, it is possible to reduce problems of contamination and/or delimitation of the gluing materials, without forming specific containment trenches.
Finally, it is clear that modifications and variations may be made to the device and the manufacturing process described and illustrated herein, without thereby departing from the scope of the present disclosure. For example, the described embodiments may be combined for providing further solutions. In particular, the MEMS device 120 may be a sensor or an actuator of a different type, which may be obtained using MEMS technology and specify a mechanical decoupling from the rest of the chip.
The various embodiments described above can be combined to provide further embodiments. These and other changes can be made to the embodiments in light of the above-detailed description. In general, in the following claims, the terms used should not be construed to limit the claims to the specific embodiments disclosed in the specification and the claims, but should be construed to include all possible embodiments along with the full scope of equivalents to which such claims are entitled. Accordingly, the claims are not limited by the disclosure.
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A micro-electro-mechanical device formed in a monolithic body of semiconductor material accommodating a first buried cavity; a sensitive region above the first buried cavity; and a second buried cavity extending in the sensitive region. A decoupling trench extends from a first face of the monolithic body as far as the first buried cavity and laterally surrounds the second buried cavity. The decoupling trench separates the sensitive region from a peripheral portion of the monolithic body.
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BACKGROUND OF THE INVENTION
[0001] The present invention relates to a method for drying ceramic articles via a microwave dryer, and in particular to methods for drying ceramic honeycomb structures via a microwave dryer that promotes uniform drying of the honeycomb structures, thereby relieving or eliminating heat-induced structural degradation of the structures.
[0002] Ceramic honeycomb structures having transverse cross-sectional cellular densities of approximately one-tenth to 100 or more cells or channels per square centimeter of honeycomb cross-section have several uses, including use as particulate filter bodies, catalyst substrates, and stationary heat exchangers. Filter applications generally require that selected cells of the structure be sealed or plugged at one or both of the respective ends thereof in a manner such that wall-flow filtration, i.e., the filtering of fluids traversing the structure by directing at least some of those fluids through porous channel walls thereof, is effected.
[0003] Ceramic honeycomb manufacture involves several known steps. In general, the honeycomb shapes are first formed, e.g., by extrusion, from water-containing plasticized mixtures of ceramic raw materials. The formed honeycombs are next dried to solidify the desired honeycomb structure, and are finally fired to sinter or reaction-sinter the ceramic raw materials into strong unitary ceramic articles.
[0004] Referring to the appended drawings, the reference numeral 8 ( FIG. 1 ) generally designates a ceramic article of a type that is well known for applications such as catalyst substrates and diesel exhaust particulate filters. The base structure in both cases is a ceramic honeycomb 10 comprising a matrix of intersecting, thin, porous cell walls 14 surrounded by an outer wall 15 . In the illustrated example structure 10 is provided in a circular cross-sectional configuration including a first end 13 , a second end 16 and a middle portion 17 . The walls 14 extend across and between a first end face 18 and an opposing second end face 20 , and form a large number of adjoining hollow passages or channels 22 which extend between and are open at the end faces 18 , 20 of the structure 10 .
[0005] To form a filter from structure 10 ( FIGS. 2 and 3 ), one end of each of the cells 22 is sealed, a first subset 24 of the cells 22 being sealed at the first end face 18 , and a second subset 26 of the cells 22 being sealed at the second end face 20 of the substrate 10 . Either of the end faces 18 , 20 may be used as the inlet face of the resulting filter. The structure 10 with seals is then fired to form the filter.
[0006] In operation, contaminated fluid is brought under pressure to an inlet face and enters the filter via those cells which have an open end at the inlet face. Because the cells are sealed at the opposite ends, i.e., the outlet face of the body, the contaminated fluid is forced through the thin porous walls 14 into adjoining cells which are sealed at the inlet face and open at the outlet face. The solid particulate contaminant in the fluid, which is too large to pass through the pore structure of the walls, is left behind and the cleansed fluid exits the filter through the outlet cells and is ready for use.
[0007] Some previous methods used for drying ceramic honeycomb structures have led to decreased structural strength due to heat-induced structural degradation. Structural strength requirements are particularly demanding for ceramic catalyst substrates and filters to be used in the mechanically harsh environment of motor vehicle exhaust emissions control systems. Nevertheless, for the mass production of such filters and substrates it is highly desirable to be able to dry the ceramic substrates rapidly and as inexpensively as possible, while maintaining structural integrity and strength.
[0008] Various drying techniques have been utilized for ceramic honeycomb manufacture in the past, including conduction heating, convection heating, and RF heating. Microwave heating has been used to achieve higher volumetric heating uniformity than conduction and/or convection heating can provide alone, while at the same time offering low operating costs and reduced processing times. However, some ceramic materials useful for constructing ceramic substrates and filters, particularly including batches for the manufacture of cordierite, mullite, aluminum titanate, and similar ceramics that include a graphite additive to increase honeycomb porosity, are more difficult to dry via microwave drying. Also problematic from a drying standpoint are honeycombs directly incorporating materials such as transition metal oxide catalysts, where the catalysts include constituents that are semiconductive or very lossy at the desired microwave drying frequency.
[0009] These drying difficulties are attributed to the inability of microwave radiation to properly penetrate into and effect uniform heating within the interior portions of such materials, due to reduced microwave permeability occasioned by the presence of graphite or other lossy materials within the ceramic batch mixtures. The consequence is that the drying of such honeycombs using microwave radiation can lead to unacceptable localized heating, which in turn leads to unstable processing, poor select rates, and lower quality ware. For example, the drying of an aluminum titanate substrate with a 30% graphite additive has produced unwanted edge heating that results in cracks and/or contour problems in the associated filter.
[0010] One possible solution to this drying problem is simply to remove damaged edge portions from the dried honeycomb parts. This solution is obviously inefficient and creates a significant amount of waste. Other solutions include changing the composition of the ceramic batch mixtures to reduce the amount of graphite or other lossy materials therein, or using multiple drying steps, or using a combination of drying methods, for example, microwave plus hot air drying, to achieve drying without structural damage. However, each of these alternatives requires accepting unwanted compromises, such as lower quality end products and/or increases in manufacturing costs.
[0011] A method for drying ceramic substrates that reduces unwanted nonuniform drying characteristics within the ceramic substrates, thereby reducing unwanted heat-induced stress cracking and structural degradation of the substrates, while simultaneously decreasing associated cycle times, and associated operating costs, is therefore desired.
SUMMARY OF THE INVENTION
[0012] The present invention relates to a method for drying a thin-walled ceramic structure such as a honeycomb comprising providing microwave radiation from a microwave generating source, providing a ceramic honeycomb structure having a middle portion and at least one end, and exposing the ceramic honeycomb structure to the microwave radiation. The method further includes shielding at least one end of the ceramic honeycomb structure from directly receiving the microwave radiation, such that the radiation absorbed by the middle portion is equal to or greater than the radiation absorbed by the at least one end. Uniform drying of the ceramic substrate with reduced heat-induced structural degradation is thereby promoted. The radiation absorbed by the middle portion is preferably within the range of from about 0% to about 60% greater than the radiation absorbed by the at least one end, and more preferably within the range of from about 10% to about 40% greater than the radiation absorbed by the at least one end.
[0013] The present method is highly accurate and repeatable, may be completed in a relatively short cycle time, is relatively easy to perform, and results in a filter with relatively greater structural integrity with reduced deformation and degradation. The method further reduces the relative cracking and stress fractures within the desired structure produced during the drying process, reduces manufacturing costs associated with cycle times, is efficient to use, and is particularly well-adapted for the proposed use.
[0014] These and other advantages of the present invention will be further understood and appreciated by those skilled in the art by reference to the following written specification, claims, and appended drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0015] FIG. 1 is a perspective view of a ceramic honeycomb structure the drying of which embodies the present invention;
[0016] FIG. 2 is a perspective view of the ceramic honeycomb structure with alternatively plugged channels;
[0017] FIG. 3 is an end elevational view of the ceramic honeycomb structure of FIG. 2 ;
[0018] FIG. 4 is a top perspective view of a microwave dryer with a plurality of ceramic honeycomb structures located within an interior thereof;
[0019] FIG. 5 is a cross-sectional top plan view of the microwave dryer of FIG. 4 , with a plurality of ceramic structures located within the interior thereof;
[0020] FIG. 6 is a cross-sectional end elevational view of the microwave dryer of FIG. 4 , with a plurality of ceramic structures located within the interior thereof;
[0021] FIG. 7 is a graph of integrated dissipation vs. length for a ceramic structure dried via conventional means;
[0022] FIG. 8 is a graph of integrated dissipation vs. width for a ceramic structure dried via conventional means;
[0023] FIG. 9 is a graph of integrated dissipation vs. length for a ceramic structure dried via conventional means, and a ceramic structure dried via the present inventive process;
[0024] FIG. 10 is a graph of integrated dissipation vs. width for a ceramic structure dried via conventional means, and a ceramic structure dried via the present inventive process; via conventional means;
[0025] FIG. 11 is a graph of integrated dissipation vs. length for three modeled sample of ceramic structures dried via the present inventive process;
[0026] FIG. 12 is a graph of integrated dissipation vs. width for three modeled sample of ceramic structures dried via the present inventive process;
[0027] FIG. 13 is a side perspective view of a first alternative embodiment of the present inventive method, including a pair of shield members shielding end faces of the ceramic structure;
[0028] FIG. 14 is a side perspective view of a second alternative embodiment of the present inventive method, including a pair of ceramic structures positioned end-to-end;
[0029] FIG. 15 is a top perspective view of a third alternative embodiment of the present inventive method, wherein the ceramic structure is spaced from the sidewalls of a microwave applicator on a support tray; and
[0030] FIG. 16 is a top perspective view of a fourth alternative embodiment of the present inventive method, including multiple spaced trays.
DETAILED DESCRIPTION
[0031] Several methods and procedures are known in the art for forming green ceramic honeycomb structures featuring a plurality of hollow passages or channels extending therethrough. The present inventive process is directed to drying such structures regardless of the specific method used to form the honeycomb shape. The present inventive method for drying ceramic honeycomb structures 10 includes providing microwave radiation from a microwave generating source 30 ( FIGS. 4-6 ) located within a microwave housing 32 , exposing the ceramic honeycomb structure 10 to the microwave radiation, and shielding at least one of the ends 13 , 16 from directly receiving the microwave radiation, such that the radiation absorbed by the middle portion 17 of the ceramic structure 10 is equal to or greater than the radiation absorbed by the at least one end 13 , 16 , as described herein. It is noted that the present inventive process may be used to process either plugged or non-plugged ceramic structures.
[0032] In the illustrated example, the microwave housing 32 includes a bottom wall 34 , a top wall 36 , and a pair of side walls 38 . The microwave generating source 30 extends downwardly from the top wall 36 and is centrally located within the microwave housing 32 . In the illustrated example, a plurality of ceramic structures 10 are positioned within an interior 40 of the microwave housing 32 , each supported by an associated support tray 42 . It is noted that the present inventive method can be accomplished either via batch style or continuous-type flow processing, and that the housing 32 may be configured to house a single structure 10 , or multiple structures. Further, the structure(s) may be horizontally or vertically oriented as the drying process is completed. A pair of planar shield members 44 are positioned within the interior 40 of the microwave housing 32 and vertically above the structure 10 between the microwave generating source 30 and the ends 13 , 16 of the structure 10 , thereby shielding the ends 13 , 16 of the ceramic structure 10 from directly receiving the microwave radiation such that the radiation absorbed by a middle portion 17 of the ceramic structure 10 is equal to or greater than the radiation absorbed at the ends 13 , 16 . Preferably, the amount of radiation absorbed by the middle portion is within the range of from 0% to 60% greater than the radiation absorbed by the ends 13 , 16 of the structure 10 , and more preferably within the range of from 10% to 40%.
[0033] As best illustrated in FIG. 6 , the shield members 44 are adjustable in several directions with respect to the ceramic structure 10 being processed, including a vertical direction 48 and a horizontal direction 50 . Adjustment in the vertical direction 48 allows an operator to adjust the vertical distance of separation X between the uppermost portion of the ceramic structure 10 and the shield member 44 . Preferably, the distance X is less than or equal to 1.5 times the wavelength of the microwave radiation, more preferably within the range of 1.5 to 1.0 times the wavelength of the microwave radiation, and most preferably is about 0.5 times the wavelength of the microwave radiation. Adjustment in the horizontal direction 50 allows the operator to adjust the amount of overlap Y each shield member 44 has with the associated ceramic structure 10 . Preferably, the amount of overlap Y is within the range of from 0% to 30% of the overall length of the structure 10 , and more preferably is within the range of from 0% to 10% of the overall length of the structure 10 . Further, the relative angle θ between each shield member 44 and a longitudinal axis 53 of the ceramic structure 10 is also adjustable in a direction 51 . Preferably, the angle θ is within the range of from 0° to 5°, and more preferably is about 0°. The adjustability of the shield members 44 allow fine tuning of the positions of the shield members 44 with respect to the ceramic structure 10 to optimize the drying thereof.
[0034] As noted above, shielding the ends 13 , 16 of the ceramic structure 10 results in a more even power distribution within the ceramic structure 10 , and as a result, a more uniform drying thereof. As best illustrated in FIG. 7 , the integrated dissipation of the power absorbed by a structure subjected to microwave radiation within a conventional microwave drying, i.e., a drying that does not provide shielding, results in a power absorption that is significantly greater at the ends of the structure than an the middle portion thereof. Similarly, FIG. 8 illustrates that the power absorbed near the side wall 15 of the structure is also significantly greater than that absorbed near the center thereof.
[0035] Modeled examples were completed on given ceramic structures both with and without shielding. FIGS. 9 and 10 illustrate integrated dissipation vs. length of the structure, and integrated dissipation vs. width of the structure, respectively, for an unshielded sample 52 and a shielded sample 54 . Further, modeled examples were completed on three variations of system configurations utilized for processing a given ceramic structure. FIGS. 11 and 12 illustrate integrated dissipation vs. length of the structure, and integrated dissipation vs. width of the structure, respectively, of the three examples A-C. Example A included the modeling of a 36 inch in length structure with the distance X of the shield members 44 above the structure 10 being 10 inches, the overlap Y of the shield members 44 with the structure 10 being 10 inches, the angle θ between the shield members 44 and the structure 10 being 0°, and the number of structures 10 within the interior 40 of the housing 32 being 5. Example B included the modeling of a 20 inch in length structure with a distance X of 10 inches, an overlap distance Y of 18 inches, an angle θ of 0°, and 5 structures 10 simultaneously located within the interior 40 of the housing 32 . Example C included the modeling of a 36 inch in length structure 10 with a distance X of 20 inches, an overlap distance Y of 10 inches, an angle θ of 0°, and 5 structures 10 simultaneously located within the interior 40 of the housing 32 . It is clear from the integrated power dissipation along the length and width of the structures that the shielded process reduces the edge heating effect. Moreover, the integrated dissipation along the major axis ( FIG. 10 ) shows a more uniform heating as compared to the end heating occurring without shielding.
[0036] Alternative methods for shielding the ends 13 , 16 and end faces 18 , 20 of the ceramic structure 10 are also contemplated. It is noted that these alternative methods may be practice simultaneously with the other methods described herein. A first alternative embodiment includes the use of shield members 60 ( FIG. 13 ) spaced from the end faces 18 , 20 of the structure 10 . In the illustrated example, the shield members 60 are placed within the tray 42 that supports and carries the structure 10 through the housing 32 . Preferably, the shield members 60 are spaced a distance A from the associated end face 18 , 20 of less than or equal to one quarter of the wavelength of the microwave radiation.
[0037] A second alternative embodiment includes spacing multiple simultaneously processed ceramic structures 10 ( FIG. 14 ) a distance B from one another. In the illustrated example, two structures 10 are placed within the same tray 42 such that the distance A between the corresponding end faces 18 , 20 reduces or eliminates access thereto by the drying microwave radiation. Preferably, the distance B is less than or equal to about one quarter of a wavelength of the microwave radiation.
[0038] Other alternative embodiments include placing the trays 42 ( FIG. 15 ) relative to the sidewalls of a microwave applicator housing 32 ( FIG. 5 ) such that the distance between the ends 18 , 20 of honeycomb structures 10 and the associated sidewalls 38 ( FIG. 5 ) is preferably less than about one half the wavelength of the microwave radiation. It is also useful to space multiple trays 42 ( FIG. 16 ) within the interior 40 of a microwave applicator housing 32 such that the distance D between the trays 42 will provide a spacing of about one half of the wavelength of the microwave radiation between the honeycomb structures 10 .
[0039] The present method is highly accurate and repeatable, may be completed in a relatively short cycle time, is relatively easy to perform, and results in a filter with relatively greater structural integrity with reduced deformation and degradation. The method further reduces the relative cracking and stress fractures within the desired structure produced during the drying process, reduces manufacturing costs associated with cycle times, is efficient to use, and is particularly well-adapted for the proposed use.
[0040] It will be understood from the foregoing that the specific devices and processes illustrated in the attached drawings and described in the foregoing specification are exemplary only, and that the specific dimensions and other physical characteristics relating to those embodiments are intended to be illustrative rather than limiting.
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A method for drying a ceramic article comprises providing microwave radiation from a microwave generating source, providing a ceramic honeycomb structure having a middle portion and at least one end, and exposing the ceramic honeycomb structure to the microwave radiation while shielding the at least one end from directly receiving the microwave radiation, such that the radiation absorbed by the middle portion is equal to or greater than the radiation absorbed by the at least one end, and the proper drying of the entire honeycomb structure without heat-induced structural degradation is thus ensured.
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This is a continuation of application Ser. No. 622,249 filed on Oct. 14, 1975 now abandoned.
BACKGROUND OF THE INVENTION
Field of the Invention
The field of the invention is that of mirrors or reflectors having the capability of being deformed in varying degrees to have a curved, generally spherical contour to provide varying degrees of magnification.
Mirrors of the general type have been known in the prior art in patents including U.S. Pat. Nos. 1,910,119; 2,403,915; 2,555,387; 2,733,637; 3,054,328; 3,610,738; 3,527,527; and 3,623,793. The prior art offers only a few variable designs having distinct limitations. Some designs are characterized by inherent limitations of minimum and maximum deflections, diameters, thickness, overall size or general configuration, and therefore are of limited utility. Further, the prior art is characterized by a relative lack in simplicity of design, construction and actuating means with the result that they are comparatively expensive to manufacture. The herein invention offers the means to overcome the aforesaid deficiencies as described in detail hereafter.
SUMMARY OF THE INVENTION
The invention relates generally to curvature forming mechanisms, and more particularly to such mechanisms embodied in variable reflectors and mirrors. Mirrors and/or reflectors of various forms are useful and necessary items in connection with many human activities. Examples include cosmetic or shaving mirrors, rear and sideview mirrors for vehicles and in passageways and other areas as well. They appear as parts of telescopes, cameras, radiation devices and various types of toys, among many other and varied uses.
Typically, mirrors are made plane and non-flexible. When other than the normal functions are desired, such as magnifying or wide angle capabilities, typically these functions are not realized in simple or effective ways. With respect to the prior art designs available, some are only unidirectional.
The invention as disclosed in the exemplary embodiments described in detail herein offer a form of frame constructed to hold a deformable reflecting member. Specific manually actuatable devices are provided for realizing the variable deformation of the reflecting member. Additionally, volume displacement means are disclosed for purposes of achieving the deformation of the reflecting member.
In the light of the foregoing, it is a primary object of the invention to overcome all the deficiencies and limitations of the prior art and to provide simple, basic and practical forms of devices embodying the concepts of deformation of the reflecting surface for variable magnification or reduction.
It is a further object of the invention to provide a basic, simplified, efficient, effective, economical reflecting body of variable shape and/or contour.
Another object is to provide a multidirectional, infinitely variable curvable reflecting member adaptable for many useful, practical and beneficial applications.
A further object is to provide a mirror or reflecting surface as referred to that is changeable in curvature or contour so that it is capable of magnifying or diminishing the reflected image to any degree desired.
Another object is to provide a variable mirror characterized in that the mechanism is able to realize infinite variations inherently capable of progressing smoothly in either direction, the progression being immediately reversible.
A further object is to provide a variable mirror as referred to that can be thinner than the standard mounted mirrors commonly in use.
A further object is to provide simplified, versatile, adjusting devices that include the characteristics of being rugged-like, compact, shockproof, shatterproof, unbreakable and capable of being operated by or with gas, liquid, magnetism or other suitable means. Also, that the devices can be constructed in any desirable practical size or shape; of a large variety of materials singly or in combination; that can be fabricated by being molded, cast, or otherwise, entirely in one piece, having the capability to function under water, in outer space or in any environment. Further that the devices are inherently safe and easy to operate by reason of the particular design, materials and modes of operation.
Further objects and additional advantages of the invention will become apparent from the following detailed description and annexed drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a pictorial view of a compact having the reflecting mirror of the invention embodied therein;
FIG. 2 is a view of the reflecting element of FIG. 1 in a position for magnification.
FIG. 3 is a view of the reflecting element of FIG. 1 in a position for reduction of the image.
FIG. 4 is a sectional view of a modified form of the invention.
FIG. 5 is a sectional view of another modified form of the invention.
FIG. 6 is a sectional view of another modified form of the invention.
FIG. 7 is a bottom view of the device of FIG. 6.
FIG. 8 is a sectional view of a modified form of the invention.
FIGS. 9, 10 and 11 are sectional views of another modified form of the invention.
FIG. 12 is a section view of another modified form of the invention.
FIGS. 13 and 14 are sectional views of modified forms of the invention.
FIGS. 15, 16 and 17 are sectional views of modified forms of the invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Having reference to FIGS. 1-3, the invention in the exemplary form shown is embodied in a compact of circular shape having a bottom part 10 and a circular cover part 12, the parts being hinged together by a hinge as shown at 13.
Cover 12 has an annular ring-shaped sidewall 14 as may be seen in FIGS. 2 and 3 which supports the reflecting diaphragm 15 as shown, its peripheral edges being sealed to the support 14. The outer surface of the diaphragm 15 is a mirror and it may be constructed of various different materials as known in the art, such as metal foil or resilient plastic, including metallized Mylar, cellophane, polyethylene, and cellulose acetate.
The compact 10 may otherwise be of conventional construction other than as described herein. Numeral 20 designates a manual actuator for deforming the mirror for magnification as in FIG. 2 or reduction as in FIG. 3. Actuator 20 will be described presently.
FIG. 4 shows a form of the invention having a flexible diaphragm 30 peripherally sealed to the support 14 and to the element 15 which is the resilient reflectively coated membrane or diaphragm. Diaphragm 15 is sealed and joined to the periphery of the diaphragm 30 and supported and under tension, if necessary, to normally present a plane mirror surface. An air space is left between the sealed members 15 and 30 to prevent distortion causing contact and provide a fluidic coupling effect between them. Thus, when the driving diaphragm 30 is actuated, the reflective plastic membrane 15 being fluidly joined thereto and influenced by atmospheric pressure is therefore driven to form a concave or convex mirror surface. Upon reduction of the actuating force, the resilient membrane 15 returns to a plane surface.
The space between members 15 and 30 can be filled with liquid to prevent loss of motion due to air compression or expansion.
Preferably diaphragm 30 as shown is made thinner for flexibility near the peripheral edges, the thickness for rigidity tapering from the center part which is of uniform thickness toward the edges. The center part is rigid and the peripheral parts are flexible.
Numeral 32 designates a stem member connected at one end to the inside of holder 14 and extending out through opening 34 in the side of holder 14. On its end is knob 36. Within the holder it is attached to diaphragm 30. The knob 36 can be pressed downwardly or upwardly to thereby pull down or upwardly on the diaphragm 30 to vary the pressure in the space between the diaphragm 30 and membrane 15, the fluid coupling effect thereby deflecting the membrane 15 from a plane surface to provide a concave or convex surface.
FIG. 5 shows another modification. In this form of the invention, there is a stem 40 connected to rigid disc 42, the stem extending through an opening 41 in the bottom 43 of the holder 14. Numeral 44 designates a sealing member at the periphery of disc 42 which seals to the inside of holder 14 allowing sliding relative movement. By pressing or pulling on the member 40, the pressure between the diaphragms can be varied to control the contour of the mirror surface by moving the fluid between the diaphragms.
FIGS. 6 and 7 show a modified form of the invention. Numeral 50 designates a stem in sliding coupling centrally through a disc 51 fixed to the diaphragm 30. It extends and slides through openings 52-53 in disc 51. It has upwardly and downwardly offset end parts 54 and 55 which extend through openings 56 and 57 in the sides of holder 14. Numerals 58 and 59 are buttons or knobs on the ends of stem 50. By pushing on either knob 58 or 59, the parts 54-55 are cammed in openings 56-57 to translate stem 50 and disc 51 upwardly or downwardly to similarly move diaphragm 30 and through the coupling to correspondingly move the diaphragm 15.
FIG. 8 shows a simple modified form of the invention wherein both diaphragms are of transparent resilient flexible material such as Mylar polyester film or other suitable material. The wall 60 is preferably circular and of rigid plastic or other suitable material. One diaphragm 62 is mirrored by aluminizing on one surface, preferably the inward enclosed side. The Mylar film protects the mirror coating from handling or other damage. The aluminized coating 63 is a mirror on both sides. The outer side is visible through the transparent Mylar film. When an edge, or any part of the clear diaphragm 64 is pressed or deformed, the resulting enclosed fluid pressure deforms the opposite diaphragm 62 outwardly; the mirror surfaces are thus driven simultaneously concave-convex, appearing concave when viewed through the driving diaphragm 64, and convex when viewed from its opposite side 62.
FIGS. 9-11 show a modified form of the invention wherein the entire device is formed by molding or otherwise as an integrated unit of suitable material such as plastic. Preferably, it is circular having a wall 70 and end diaphragms 72 and 74. One diaphragm 72 is mirrored. Force may be applied to the other to deform the mirror through the coupling. In FIGS. 9-11, the unit has knob 76 which can be pushed or pulled as shown. Thus, member 72 is caused to form a convex surface as in FIG. 10 or concave as in FIG. 11.
FIG. 12 shows a modified form of the invention which is actuated by volume displacement. Diaphragm 15' is within holder 80. The spaces on opposite sides of the diaphragm are connected by tubes 82 and 84 to ends of cylinder 86 having in it piston 88. Piston 88 is actuatable by pivoted manual arm 90 toward one end or the other of cylinder 86 to vary the fluid volume ratio on each side of the diaphragm 15' so as to deform it one way or the other. Thus, the curvature is varied by relative displacement of fluid. Diaphragm 15' is mirrored on both sides and the sides of holder 80 are transparent so diaphragm 15' can be viewed from either side.
FIGS. 13 and 14 show modified forms wherein a plane rigid supporting disc 92 preferably circular and having a small central hole 94 for passage of the contained fluid coupling medium, is between the mirrored membrane 15 and the driving member. In FIG. 13 the driving member is diaphragm 96 which is thinner at the periphery like diaphragm 30, FIG. 4. These configurations are meant for use as a rear view mirror for vehicles and like applications. Actuation may be manually and remotely accomplished by hand, foot, turn signal lever coupling, cable, solenoid or the like.
In FIG. 14, the actuation is by way of squeeze bulb 97 and/or 97' connected by flexible tubes 100, 100' and 102 to hole 94. The advantageous and necessary limitation of these configurations are: as the mirror may be driven from its normal plane form to a convex wide angle viewing form, the disc 92 prevents the membrane from forming a concave, magnifying mirror. In a concave mirror, distant images appear out of focus, or inverted. A concave rear view mirror is therefore undesirable and indeed dangerous.
FIG. 15 shows a modified form of the invention that is molded or otherwise as a complete unit 110 of plastic or other suitable material. It includes bowed member 111 having corrugations 112 and 112' and integral diaphragm 15. It may have a knob like knob 76 of FIGS. 9-11. The corrugations 112 and 112' allow movement of members 111 toward and away from diaphragm 15. The coupling medium is air or any desired type or quantity of fluid matter, which may be inserted, changed or adjusted by hypodermic or like methods. The unit is of self-sealing material or may be sealed by any of several well-known methods to the art. The driving part 111 forms to a generally paraboloidal shape to avoid any distorting contact with the mirror 15 in concave formation. The extending periphery of part 111 provides protection to the mirror part 15.
FIG. 16 shows a form of the invention fabricated of transparent plastic or other suitable material, and like FIG. 15, is made of a single integral piece 120. It resembles a section of modified bellows and operates on similar principles. Diaphragm 15 is opposite thicker, more rigid wall 121, the diaphragm and wall 121 being joined by the peripheral part having a section as designated at 122. Force applied across the major diameter causes the minor diameter to increase, thereby increasing the enclosed volume, thus decreasing its relative pressure. The pressure differential causes the thin membranous mirrored 15 section to deform inwardly, effectively concave, when viewed from the top. Force applied across the minor diameter, preferably near the periphery, produces opposite results.
FIG. 17 shows a sectional view of a variable reflector device that is molded, cast or otherwise in the shape of a solid cylinder (i.e., disc) 130, of homogenous material such as a foamed plastic elastic substance. The surface portion 131 is cast or otherwise processed to have somewhat greater density and stiffness than the body of the disc and having the necessary smooth and normally plane mirrored surface 15 able to present a well-figured variable reflection. The opposite surface portion may also be formed to have greater density and stiffness. The greater density and stiffness also serve to properly transmit and/or receive applied force or pressure to cause the reflectorized surface 15 to deform concave or convex, returning to a plane when not otherwise actuated. The deformation may be accomplished as in the previous embodiments.
It is inherent in each configuration that the reflector member normally returns to a plane form if the driver member is destroyed or the actuating force is removed. In referring to the reflector member as deformable, it is intended that this term shall embrace materials having the quality or characteristic of being elastic.
From the foregoing those skilled in the art will readily understand the nature and the construction of the invention and the manner in which it achieves and realizes all of the objects as set forth in the foregoing.
The foregoing disclosure is representative of the preferred forms of the invention and is to be interpreted in an illustrative rather than a limiting sense. The invention is to be accorded the full scope of the claims appended hereto.
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A variable mirror having a reflecting surface which can be formed to have a curved, that is, a convex or concave contour to provide variable degrees of magnification. The mirror is adapted for utilization in a compact or vanity case, or the like. Various mechanisms are provided for varying the degree of curvature and magnification of the mirror, these means preferably being manually actuatable.
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BACKGROUND OF THE INVENTION
The present invention relates to a deinking agent for reclaiming waste paper used in preparing reclaimed pulp from printed waste paper such as newspaper, magazine and so on, and more specifically to a deinking agent for reclaiming waste paper which is suitable for using in a flotation process.
It has been conducted for a long time that paper pulp is reclaimed from printed waste paper such as newspaper, magazine to reuse the resulting reclaimed pulp as a feedstock for papermaking. In particular, recently the recycle of waste paper has been increasingly important and the resulting reclaimed pulp has widely been used in various fields from the viewpoint of effective use of various resources and of the environmental protection.
When printed waste paper is intended to be reused, the waste paper is reclaimed as waste paper pulp by using a disintegrator such as a pulper with an alkaline agent such as sodium hydroxide, sodium carbonate or sodium silicate, a bleaching agent such as hydrogen peroxide or sodium hypochlorite, a chelating agent such as EDTA and DTPA, and a deinking agent, for example, anionic surfactant such as fatty acid, alkylbenzenesulfonates, α-olefinsulfonates, higher alcohol sulfate salts and dialkylsulfosuccinate; nonionic surfactants such as alkylene oxide adducts of higher alcohol, alkylphenols and fatty acids; and a mixture thereof.
In order to enhance the deinking efficiency, deinking devices such as kneader, refiner and disperser have been improved to make the ink removed from the waste paper into fine particles in deinking process.
However the above-mentioned deinking agents are insufficient to collect the ink removed from the waste paper in the flotation process and thus they cannot provide high quality reclaimed pulp having high whiteness and a low content of remaining ink.
Japanese Patent unexamined publication (hereinafter referred to as J. P. Kokai) No. 51-53005 discloses a deinking agent comprising a quaternary ammonium salt cationic surfactant and J. P. Kokai No. 64-6190 also discloses a deinking agent comprising a combination of nonionic surfactant and a quaternary ammonium salt cationic surfactant wherein part of alkyl groups are replaced by hydroxyl. However the deinking agents do not have sufficient ability to deink from the waste paper, that is, the resultant reclaimed pulp has high content of remaining ink and low whiteness due to resticking part of the removed ink to the pulp.
SUMMARY OF THE INVENTION
Accordingly, an object of the present invention is to provide a deinking agent for reclaiming printed waste paper which provides high quality reclaimed pulp having high whiteness and a low content of remaining ink.
Another object of the present invention is to provide a deinking agent for reclaiming printed waste paper which can efficiently release ink from the waste paper in the disintegration process and which have excellent ability of collecting the ink and suitably foaming in the flotation process.
These and other objects of the present invention will be apparent from the following description and Examples.
The inventors of this invention have performed various studies to develop a deinking agent having preferred properties such as those discussed above and they have found out that the product obtained by quaternizing with quaternizing agent, a reaction product of an amine having at least two active hydrogens in its molecule, a fatty acid and/or a fatty acid alkyl ester and alkylene oxides has an excellent deinking ability to efficiently resolve the above problems. The present invention is accomplished on the basis of the finding.
Accordingly, the present invention provides a deinking agent for reclaiming waste paper comprising a mixture obtained by treating, with a quaternizing agent, a product prepared by addition of alkylene oxide to a reaction product of an amine having at least two active hydrogen atoms in its molecule with a fatty acid and/or a fatty acid alkylene esters, an amount of the quaternizing agent being 0.1 to 0.9 mole per mole of the amine.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
In a preferred embodiment, the present invention provides a deinking agent comprising a compound of the following formula (I) and a quaternary ammonium compound thereof in a molar ratio of from 9/1 to 1/9, preferably 4/1 to 2/3:
N(R.sup.1)(R.sup.2) R.sup.3 (I)
wherein R 1 is --C(O)R 4 or --(C 2 H 4 O)C(O)R 4 ; R 2 is --(C 2 H 4 O)--(AO) m H or --(AO) m H; R 3 is --C(O)R 4 or --(C 2 H 4 O)C(O)R 4 ; R 4 is C 9-23 alkyl or C 9-23 alkenyl; m is an integer from 40 to 100, preferably from 40 to 75 and A is C 2-4 alkylene. The quaternary ammonium compound of the compound having formula (I) possesses C 1-18 alkyl groups or an aryl groups, preferably methyl, ethyl or benzyl at the position of coordinate bond on the nitrogen atom.
Examples of the fatty acids for producing the deinking agent of the present invention include fatty acids, semi-hardened fatty acid and hardened fatty acid derived from animal oiles such as lard and tallow and vegetable oils, such as, olive oil, palm oil, soybean oil, rapeseed oil, linseed oil and coconut oil, fish oils and the like, and synthesized fatty acid having 10 to 24 of carbon atoms. Preferred are saturated or unsaturated straight chain fatty acid having 12 to 18 of carbon atoms. These fatty acids may be used alone or as a mixture of two or more of them. Examples of the fatty acid alkyl esters usable in the invention include C 1-10 alkyl esters of the above fatty acid, preferably C 1-3 alkyl esters such as methyl ester.
Examples of the amines having at least two active hydrogens for producing the deinking agent of the present invention include mono-, di- and trialkanol amines which have 2 to 12 of carbon atoms. Among these, preferred are monoethanol amine, diethanol amine and triethanol amine, more preferably triethanol amine.
Examples of the alkylene oxides for producing the deinking agent of the present invention include ethyleneoxide, propyleneoxide, butyleneoxide and the like. It may be used singly or in combination, when two or more alkylene oxides are used the alkylene oxides may be added to the reaction product by using a mixture of two or more alkylene oxides (random addition) or successive adding of the alkylene oxides (block addition). In particular, the random addition or the block addition using a ethyleneoxide and alkenyleneoxide other than the ethyleneoxide are preferably. A ratio of the ethyleneoxide is preferably not less than 50 molar percent of total alkylene oxides.
At the quaternazing agent for producing the deinking agent of the present invention, alkylhalides having from 1 to 18 of carbon atoms, arylhalides and alkylsulfates having from 1 to 18 of carbon atoms are preferable. Specific examples of the quaterazing agent include methyl chloride, benzyl chrolide, dimethyl sulfate and diethyl sulfate.
In accordance with the present invention, the deinking agent can be produced by reacting the above mentioned fatty acid and/or fatty acid alkyl ester, the amine, the alkylene oxide and the quaternizing agent in an optional ratio. However it is desirable to use 1.0 to 3.0 mole, preferably 1.5 to 2.5 mole of the fatty acid and/or the fatty acid alkyl ester; 40 to 100 mole, preferably 40 to 75 mole of the alkylene oxide; 0.1 to 0.9 mole, preferably 0.2 to 0.6 mole of the quarterizing agent relative to 1 mole of the amine. When the amount of the fatty acid and/or fatty acid alkyl ester, the amine, the alkylene oxide and the quaternizing agent is adjusted within the mole range mentioned above, the removal of the ink from the waste paper is increased and the ability of collecting the ink in the flotation process is enhanced. The reclaimed pulp having high whiteness cannot be obtained in less than 0.1 mole of the quaterizing agent per mole of the amine since the resulting deinking agent has weak properties of collecting ink and the fine ink particles cannot be completely collected. The reclaimed pulp having high whiteness cannot be also obtained in 1.0 mole or more of the quaterizing agent per mole of the amine since the resulting deinking agent has strong properties of removing the ink and the reclaimed pulp is recontaminated by the removed ink.
The reaction of the fatty acid or the fatty acid alkyl ester and the amine is not limited to specific one, but the reaction can be carried out by the conventional amide forming reaction of the fatty acid and the amine, esterification reaction of an alcoholic hydroxy group in the amine and the fatty acid, or ester exchange reaction of the alcoholic hydroxy group in the amine and the fatty acid alkyl ester. In the preferred embodiment, the fatty acid and triethanol amine in the mole ratio as mentioned hereinbefore may be esterified in the presence of or absence of acidic or alkaline catalyst at a temperature of 100° to 250° C. under a reduced pressure.
The alkylene oxide may be additionally reacted with the reaction product of the fatty acid or the fatty acid alkylester and the amine under the conventional condition in which addition reaction of the alkylene oxide to a compound having an active hydrogen is conducted. The addition reaction of the alkylene oxide to the above mentioned esterified reaction products can be conducted in the presence of a catalytic amount of alkaline material at a temperature of about 100° to about 200° C. under 1 to 3 kg/cm 2 of the pressure for several hours.
Quaterizing reaction of the resulting alkylene oxide adducts may be conducted under the conventional condition in which a tertiary amine is quaternized. It can be quaterized by adding diethylsulfate to the alkylene oxide adducts and then reacting them at a temperature ranging from 40° to 140° C. for several hours.
The deinking agent of the present invention has excellent properties and also has the properties when it is combined with one or more known deinking agents such as fatty acids, salts of higher alcohol sulfate, alkylbenzen sulfonates, alkylene oxide adducts, higher alcohol, alkylphenol and fatty acid. The deinking agent of the invention may be added to either the disintergration process or aging process or may be added to these two processes. The agent is the most effective in adding to the disitergration process. It is preferably to add the agent to the waste paper in a range of 0.2 to 1.0 percent by weight (hereinafter abbreviated to %) relative to the weight of the waste paper.
The deinking agent of the present invention has excellent properties of removing the ink fixed on pulp fiber of the printed waste paper such as newspaper and magazine and also excellent properties of collecting the ink in the flotation process. A use of the deinking agent therefore provides a high quality reclaimed pulp having high whiteness and a low content of remaining ink and enables to stably conduct a deinking process without any foaming problems.
The present invention will hereinafter be described in more detail with reference to the following non-limitative working examples and preparation examples.
EXAMPLE 1
Preparation of the deinking agent
2 moles of tallow fatty acid and 1 mole of triethanol amine were added to an autoclave and then the temperature was increased with stirring to dehydrate at a temperature of 160° C. under a reduced pressure. 0.3 % of an alkaline catalyst (relative to the weight of the resulting alkylene oxide adduct) was added thereto and then 20 moles of ethylene oxide (EO) and 30 moles of propylene oxide (PO) were mixed therewith to conduct an addition reaction of alkylene oxide at a temperature of 150 ° C. under the pressure of 3 atoms. 0.5 mole of diethylsulfate was added to the reactant and uniformly stirred at 70° C. for 1 hour to prepare the deinking agent shown in table 1.
A test of deinking ability
Printed waste paper as a starting material (offset-printed waste paper/typographically-printed waste paper/leaflet=4/3/3 (weight ratio)) was cut into pieces of 3×3 cm, charged into a pulp disintegrator. There were added, on the basis of the weight of the waste paper, 1.0 % of sodium hydroxide, 3.5 % of sodium silicate (No.3), 1.0 % (effective amount) of hydrogen peroxide and 0.35 % of the deinking agent listed in Table 1 to the disintegrator followed by addition of hot water in an amount sufficient to adjust the concentration of the pulp to 5 % and disintegration at 35° C. for 7 minutes. The resulting pulp slurry was soaked at 65° C. for 60 minutes, added hot water in an amount sufficient to adjust the concentration of the pulp slurry to 1% followed by flotation at 30° C. for 7 minutes. After the flotation, the pulp slurry was concentrated to 10 % and then diluted to 1% with water followed by preparation of the pulp sheet from the pulp slurry using a TAPPI sheet machine.
The whiteness of the resulting pulp sheet was determined by color measurement color difference meter and the amount of the remaining ink was determined in terms of rate of area carrying the remaining ink measured by an image analyzer. The result of the test was shown in Table 2.
EXAMPLES 2
The deinking agent was prepared by the same procedure used in Example 1 except that ingredients listed in table 1 were used. The resulting deinking agent was tested in the same way as Example 1. The result of the test is shown in Table 2.
COMPARATIVE EXAMPLE 1
Tallow trimethyl ammonium chloride which is a conventional deinking agent was tested in the same way as in Example 1. The result of the test is shown in Table 2.
COMPARATIVE EXAMPLE 2
A mixture of tallow fatty acid and C 12 H 26 (C 2 H 4 O) 3 SO 3 Na in a ratio of 0.5/0.08 (%) was used and calcium chloride was added in an amount of sufficient to adjust a content of calcium to 50 ppm in the flotation process. The deinking agent was tested in the same way as Example 1. The result of the test is shown in Table 2.
COMPARATIVE EXAMPLE 3
A reactant product of 1.0 mole of trierhanol amine and 2 moles of methyl ester of palm oil fatty acid was subjected to an addition reaction with 70 moles of EO followed by quaterizing the resulting product with 1.0 mole of dimethyl sulfate to obtain the deinking agent. The deinking agent was tested in the same way as Example 1. The result of the test is shown in Table 2.
COMPARATIVE EXAMPLE 4
A reactant product of 1.0 mole of trierhanol amine and 2 moles of tallow fatty acid was subjected to an addition reaction with 20 moles of EO and 50 moles of PO to obtain the deinking agent. The deinking agent was tested in the same way as Example 1. The result of the test is shown in Table 2.
TABLE 1______________________________________Composition of the deinking agents Fatty acid or Quaterizing Fatty acid Mole Alkylene agentExample of ratio Oxide moleNo. alkyl ester Amine *1) mole *2) ratio *3)______________________________________1 Tallow Tri- 2.0/1.0 EO/PO Diethyl fatty acid ethanol 20/30 sulfate amine (random) 0.5/1.02 Methyl Di- 2.0/1.0 EO/BO Methyl ester ethanol 60/15 chloride of tallow amine (block) 0.3/1.0 fatty acid______________________________________ *1) A reaction ratio of the fatty acid and the amine *2) EO is ethylene oxide, PO is propylene oxide and BO is butylene oxide. *3) A reaction ratio of the quaterizing agent and the amine
TABLE 2______________________________________The result of the test Remaining ink Whiteness(%) (number/1 field)______________________________________ExampleNo. 1 57.1 0.178No. 2 57.4 0.157ComparativeexampleNo. 1 50.4 1.139No. 2 51.9 1.041No. 3 52.5 0.985No. 4 53.4 0.886______________________________________
EXAMPLES 3 TO 5
The deinking agents were prepared by the same procedure used in Example 1 except that ingredients listed in Table 3 were used. The printed waste paper was deinked by using each deinking agent in a method mentioned hereinafter and then the results were evaluated in the same way as Example 1. The result of the test is shown in Table 4.
A test of deinking ability
Printed waste paper as a starting material (offset-printed waste paper/typographically-printed waste paper/leaflet=4/3/3 (weight ratio)) was cut into pieces of 3×3 cm, charged into a pulp disintegrator. There were added, on the basis of the weight of the waste paper, 1.0 % of sodium hydroxide, 3.5 % of sodium silicate (No.3), 1.0 % (effective amount) of hydrogen peroxide and 0.35 % of the deinking agent listed in Table 3 to the disintegrator followed by addition of hot water in an amount sufficient to adjust the concentration of the pulp to 15% and disintegration at 55° C. for 15 minutes. The resulting pulp slurry was soaked at 65° C. for 60 minutes, added hot water thereto in an amount sufficient to adjust the concentration of the pulp slurry to 5% followed by disintegration for 1 minute. After the disintegration, the pulp slurry was diluted to 1% with hot water followed by flotation of the pulp slurry at 30° C. for 7 minutes. After the flotation, the pulp slurry was concentrated to 10% and then diluted to 1% with water followed by preparation of the pulp sheet from the pulp slurry using a TAPPI sheet machine.
COMPARATIVE EXAMPLE 5
The deinking agent was prepared by mixing an adduct reactant of nonylphenyl and 9 moles of EO with tallow trimethyl ammonium chloride in a ratio of 0.35 to 0.10 (%). The printed waste paper was deinked by using the resulting deinking agent in the same method as Example 3 and then the test of the deinking ability was determined by the same way as Example 1. The result of the test is shown in Table 4.
COMPARATIVE EXAMPLE 6
α-olefin sulfonate was used as a deinking agent. The printed waste paper was deinked by using the α-olefin sulfonate in the same method as Example 3 and then the test of the deinking ability was determined by the same way as Example 1. The result of the test is shown in Table 4.
COMPARATIVE EXAMPLE 7
A reactant product of 1.0 mole of triethanol amine and 2 moles of methyl ester palm oil fatty acid was subjected to an addition reaction with 70 moles of EO followed by quaterizing the resulting product with 1.0 mole of dimethyl sulfate to obtain the deinking agent. The printed waste paper was deinked by using the resulting deinking agent in the same method as Example 3 and then the test of the deinking ability was determined the same way as Example 1. The result of the test is shown in Table 4.
COMPARATIVE EXAMPLE 8
A reactant product of 1.0 mole of trierhanol amine and 2 moles of tallow fatty acid was subjected to addition reaction with a mixture of 20 moles of EO and 50 moles of PO to obtain the deinking agent. The printed waste paper was deinked by using the resulting deinking agent in the same method as Example 3 and then the test of the deinking ability was determined by the same way as Example 1. The result of the test is shown in Table 4.
COMPARATIVE EXAMPLE 9
A reactant product of 1.0 mole of triethanol amine and 2 moles of coconut oil fatty acid was subjected to addition reaction with a mixture of 25 moles of EO and 5 moles of PO. The resulting product was quaterized to obtain the deinking agent by reacting with 1.0 mole of dimethyl sulfate. The printed waste paper was deinked by using the resulting deinking agent in the same method as Example 3 and then the test of the deinking ability was determined by the same way as Example 1. The result of the test is shown in Table 4.
TABLE 3______________________________________Composition of the deinking agents Fatty acid or Quaterizing Fattty acid Mole Alkylene agentExample of ratio Oxide moleNo. alkyl ester Amine *1) mole *2) ratio *3)______________________________________3 Coconut oil Mono- 1.5/1.0 EO/PO Benzyl fatty acid ethanol 70/30 chloride amine (random) 0.6/1.04 Stearic acid Tri- 2.0/1.0 EO/PO Dimethyl ethanol 30/10 sulfate amine (block) 0.2/1.05 Hardened Tri- 2.0/1.0 EO/PO Dimethyl tallow ethanol- 50/25 sulfate fatty acid amine (block) 0.4/1.0______________________________________ *1) A reaction ratio of the fatty acid and the amine *2) EO is ethylene oxide, PO is propylene oxide and BO is butylene oxide. *3) A reaction ratio of the quaterizing agent and the amine
TABLE 4______________________________________The result of the test Remaining ink Whiteness(%) (number/1 field)______________________________________ExampleNo. 3 57.2 0.131No. 4 57.9 0.108No. 5 58.3 0.092ComparativeexampleNo. 5 51.6 0.973No. 6 51.8 0.970No. 7 52.6 0.924No. 8 53.5 0.807No. 9 51.9 0.951______________________________________
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A deinking agent comprises a compound of the following formula (I);
N(R.sup.1)(R.sup.1) R.sup.2 (I)
wherein R 1 is --C(O)R 4 or --(C 2 H 4 O)C(O)R 4 ; R 2 is --(C 2 H 4 O)--(AO) m or --(AO) m ; R 3 is --C(O)R 4 or --(C 2 H 4 O)C(O)R 4 ; R 4 is C 9-23 alkyl or C 9-23 alkenyl; m is a integer from 40 to 100 and A is C 2-4 alkylene, and a quaternary ammonium compound thereof in a molar ratio of 9/1 to 1/9. The deinking agent for reclaiming printed waste paper has abilities to efficiently release the ink from the waste paper in the disintegration process and to collect the ink and produce suitable foam in the flotation process, which provides high quality reclaimed pulp having high whiteness and a low content of remaining ink.
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BACKGROUND OF INVENTION
This invention was made with Government support under Contract No. NAS3-24628 awarded by the National Aeronautics and Space Administration. The Government has certain rights in this invention.
The invention relates to rotary internal combustion engines of the type disclosed in prior U.S. Pat. No. 2,988,065 granted on June 13, 1961 to Wankel et al, and particularly to such an engine designed for operation as a stratified charge engine and employing two high pressure fuel injection nozzles, as disclosed in U.S. Pat. No. 4,083,329 granted on 11 April 1978 to Meyers.
Various stratified charge rotary engine designs are known, one such design being described in the aforementioned Meyers Patent. This system includes a pilot fuel injector, a main fuel injector and a single spark plug which ignites fuel from the pilot injector. The burning pilot fuel then ignites the fuel/air mixture in the rotating combustion pocket injected by the main injector. It is believed that the presence of a richer-than-flammable fuel/air mixture in the center of the pocket retards the flame propagation from the leading portion of the pocket to the trailing portion, even though a flammable fuel/air mixture is available on the trailing side of the richer-than-flammable mixture. This may slow down the burning process and reduce combustion efficiency.
Other stratified charge arrangements are described in U.S. Pat. No. 3,980,054 issued 14 September 1976 to Kono and in U.S. Pat. No. 4,036,183 issued 19 July 1977 to Igashira et al. These systems include a pair of spark plugs located on either side of the minor axis of the rotor housing. However, the engine described in these latter patents have fuel injection systems wherein fuel is introduced in the air intake passage almost opposite to the top-dead-center region of the engine. The spark plug arrangement shown in the '054 and '183 patents could not be utilized with the pilot/main fuel injector arrangement of the '329 patent. Accordingly, it would be desirable to provide a pilot/main injector type stratified charge fuel injection system which could accommodate a pair of spark plugs.
SUMMARY OF THE INVENTION
An object of the present invention is to provide a stratified charge rotary combustion engine with improved combustion efficiency.
These and other objects are achieved by the present invention wherein a rotary internal combustion engine includes main and pilot fuel injectors. The main fuel injector is positioned between the two spark plugs and has a central axis which is inclined with respect to the plane of rotor rotation.
BRIEF DESCRIPTION OF DRAWINGS
FIG. 1 is a schematic partial transverse sectional view of a top-dead-center region of a rotary combustion engine embodying the invention;
FIG. 2 is a sectional view taken along lines 2--2 of FIG. 1.
DETAILED DESCRIPTION
Referring to FIGS. 1 and 2, a rotating combustion engine 10 comprises an outer body or housing consisting of two axially spaced end housings (not shown) and an intermediate or rotor housing 12, the housings being secured together to form the engine cavity therebetween. An inner body or rotor 18 is journaled for rotation within said housing cavity on an eccentric portion of a shaft (not shown) which extends coaxially through and is supported by bearings (not shown) in the end housings.
The peripheral inner or running surface 24 of the intermediate housing 12 has a two-lobe profile which preferably is basically an epitrochoid, the two lobes joining at minor axis or junction 25. Each of the three working faces of the rotor 18 preferably is provided with a trough-like recess 19 therein.
The engine 10 also includes suitable gearing (not shown) between the rotor 18 and the engine housing to control the relative rotation of the rotor. Such gearing is conventional and preferably is similar to that illustrated in the aforementioned patent to Wankel et al.
A pilot fuel injector 50 is mounted on the intermediate housing 12 adjacent to and downstream of the lobe junction 25. The pilot injector 50 has its fuel discharge end disposed in a recess 51 opening to the trochoidal surface 24 for discharging fuel into each working chamber after the air-intake charge within the chamber has been substantially compressed and combustion is about to be initiated. A first spark plug type igniter 52 is also mounted on the intermediate housing adjacent to the lobe junction 25 and adjacent to and upstream from the injector 50. The electrodes of the spark plug 52 are disposed adjacent to the discharge end of the injector 50 preferably so that the injector discharge end and the spark plug electrodes both open through the trochoidal surface 24 through the same common recess 51. In addition, the injector 50 and spark plug 52 preferably are disposed so that at least a portion of the fuel vapor produced by fuel spray discharged from the pilot injector passes in close proximity to the spark plug electrodes as the fuel leaves the pilot injector for ready ignition by the spark plug 52.
A main fuel injector 60 is mounted on the intermediate housing 12 also adjacent to the lobe junction 25 but on the upstream side of the junction. As best seen in FIG. 2, the main injector 60 is inclined with respect to the plane of rotation of the rotor 18 by approximately 30 degrees. As in the case of the pilot injector 50, the main fuel injector 60 is arranged to initiate the discharge of its fuel into each working chamber 28 after the air charge in the chamber has been substantially compressed and combustion is about to be initiated in a timely manner relative to discharge of fuel from the pilot injector 50. For example, at low engine loads discharge of fuel from the main injector 60 into each working chamber 28 may be initiated somewhat after fuel is discharged from the injector 50 whereas at high engine loads in order to provide time for fuel discharge from the main injector 60, the fuel discharge from this main injector can be initiated somewhat before fuel is discharged from the pilot injector 50. As a result, the combustion flame resulting from the ignition by the spark plug 52 of the fuel discharging from the pilot injector 50 into each working chamber 28 is effective to ignite the fuel discharged from the main injector 60 into the chamber. Thus, the burning fuel discharged by the pilot fuel injector 50 functions as a pilot flame to ignite the fuel discharged by the main injector 60.
A second spark plug type ignition device 70 is positioned adjacent to and upstream of the main injector 60 so that the main injector is located generally between the first and second spark plugs 52 and 70. The pilot injector 50 and the spark plugs 52 and 70 are aligned with the plane of rotation of the rotor 18.
As described in U.S. Pat. No. 3,894,518 to Gavrun et al, an ignition circuit (not shown) for the spark plug 52 is arranged to fire the spark plug while fuel is discharging from the nozzle 50 into a working chamber 29 so that a portion of this fuel is ignited at the fuel injector 50 as it discharges from the injector and the burning of this initial portion of the fuel discharged from the injector 50 ignites the balance of the fuel discharging from the injector. The timing of the spark from the spark plug 52 is such that it fires during the period of discharge from the injector 50 into a working chamber 28 and preferably during the initial period of such discharge into each working chamber 28. The second spark plug 70 would be fired to ignite the flammable mixture on the trailing side of the minor axis, and upstream of the richer-than-flammable mixture (not shown) in the central region of the combustion pocket. It is predicted that this two-spark plug arrangement will better ignite the fuel/air mixture and improve the combustion efficiency.
While the invention has been described in conjunction with a specific embodiment, it is to be understood that many alternatives, modifications and variations will be apparent to those skilled in the art in light of the aforegoing 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.
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A stratified charge rotary combustion engine includes a main fuel injector, a pair of spark plugs and a piot fuel injector. The first spark plug is located upstream of the pilot fuel injector. The second spark plug is located upstream of the main fuel injector and is located upstream of the center of the top-dead-center region of the housing.
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FIELD OF THE INVENTION
The present invention relates to a cathode assembly for use in industrial electrolysis and a method of reactivating the cathode assembly.
BACKGROUND OF THE INVENTION
Sodium hydroxide and chlorine are important industrial starting materials. These are produced mainly by the electrolysis of sodium chloride. Processes for the electrolysis of sodium chloride have shifted from the mercury process, in which a mercury cathode is used, and the diaphragm process, in which an asbestos diaphragm and a soft-iron cathode are used, to the ion-exchange membrane process, in which an ion-exchange membrane as a diaphragm and an activated cathode having a low overvoltage are used. During the course of these developments, the electric power consumption rate for the production of 1 ton of caustic soda has decreased to 2,000 kWh.
Examples of processes for producing an activated cathode active in hydrogen generation for use in the ion-exchange membrane process include: a method in which a ruthenium oxide powder is dispersed into a nickel plating bath and composite plating is conducted onto an electrode base to obtain an active electrode; a method in which a nickel deposit containing a second ingredient such as sulfur or tin is formed by plating; and a method in which NiO plasma spraying is used. Examples thereof further include method in which Raney nickel, an Ni--Mo alloy, a Pt--Ru deposit formed by displacement plating, or the like is used. An activated cathode is also known in which a hydrogen-absorbing alloy is used in order to impart resistance to reverse current.
These techniques are described in the following publications (1) to (4).
(1) Electrochemical Hydrogen Technologies, pp. 15-62 (1990)
(2) U.S. Pat. No. 4,801,368
(3) J. Electrochem. Soc., 137, pp. 1419-1423 (1993)
(4) Modern Chlor-Alkali Technology, Vol. 3, pp. 250-262 (1986)
Recently, electrolytic cells which can be used in the ion-exchange membrane process at a heightened current density are being investigated in order to increase production capacity and reduce investment cost. Because low-resistance membranes have been developed, it has become possible to impose a high-density current load onto an electrode.
In the ion-exchange membrane process, the anode is usually an insoluble metal electrode (DSA). In view of the fact that DSA's have been used as anodes in the mercury process at current densities as high as up to 200 to 300 A/dm 2 , use of a DSA in electrolysis by the ion-exchange membrane process at such a high current density seems to pose no problem with respect to the anode alone. However, it is still unknown that existing cathodes can be used because their useful life and performance characteristics have not been confirmed at such high current densities in real cells.
Specifically, the cathode for use in the ion-exchange membrane process needs to exhibit the following characteristics: a low overvoltage; no damage to the membrane even upon contact with the cathode; and reduced release of fouling ingredients, e.g., metal ions. If there is no cathode which has these properties, a conventionally used cathode (one having high surface roughness and a catalyst layer of low mechanical strength) is employed. Basically, however, certain measures are necessary for the use of such a conventional cathode. On the other hand, for realizing the new process in which electrolysis is conducted at a high current density, there is a need to develop an activated cathode which has the above characteristics and is sufficiently stable even under the above-described electrolysis conditions.
FIG. 2 diagrammatically shows the currently most common process for sodium chloride electrolysis using an activated cathode. In this sodium chloride electrolysis, a cathode 3 is disposed on the cathode side, i.e., on one side, of a cation-exchange membrane 1 so that it is in contact with the membrane (zero gap) or is apart therefrom to form a gap of up to 3 mm. An anode 2 is disposed on the other side of the cation-exchange membrane 1. On the catalyst layer of the cathode 3, water containing sodium chloride reacts to yield sodium hydroxide.
The anode and cathode reactions are as follows.
2Cl.sup.- →Cl.sub.2 +2e.sup.- (1.36 V)
2H.sub.2 O+2e.sup.- →2OH.sup.- +H.sub.2 (-0.83 V)
The theoretical electrolytic potential is 2.19 V.
Conventional activated electrodes, when used in cell operation at a high current density, exhibit some serious problems which need to be solved as follows.
(1) Since the electrodes employ bases comprising nickel, iron, carbon, etc., these bases partly dissolve away as the electrodes deteriorate due to high current density. The dissolved base ingredients which have thus eluted into the catholyte move to the membrane and the anode chamber, leading to a decrease in product quality and impaired electrolytic performance.
(2) The overvoltage increases with increasing current density, resulting in reduced energy efficiency.
(3) As the current density becomes higher, the cell exhibits increased unevenness in the distribution of bubbles and in the concentration of the caustic soda that is produced. Hence, the catholyte exhibits an increased solution resistance loss.
It may be desirable to place the cathode 3 in contact with the ion-exchange membrane 1 such that there is no gap between the cathode material and the ion-exchange membrane, because this constitution should be effective in lowering the electrolytic voltage. However, because the cathode 3 has a rough surface, the cathode 3 may mechanically break the ion-exchange membrane 1 when used in contact therewith. Consequently, use of the conventional cathode 3 at a high current density in such a zero-gap constitution has been problematic.
If an existing cell needs almost no modification for efficient operation at both low and high current densities, this brings about a considerable economic advantage. On the other hand, when electrode deterioration has occurred, it is necessary to re-form the catalyst layer of the cathode. In many cases, however, this reactivation is technically or economically difficult.
SUMMARY OF THE INVENTION
Accordingly, an object of the present invention is to provide a cathode assembly which eliminates the above-described problems of the prior art, and which can be used in an electrolytic cell that is operated at a high current density.
Another object of the present invention is to provide a cathode assembly which eliminates the above-described problems of the prior art, and which can be used in electrolysis in an existing cell at a high current density.
The present invention achieves the above-described objectives by providing:
(1) A cathode assembly comprising a cathode, an ion-exchange membrane, and an electroconductive porous member permeable to gas and liquid sandwiched between the cathode and the membrane.
(2) The cathode assembly as described in (1) above, wherein the porous member comprises a catalyst active in hydrogen generation deposited on a part thereof.
(3) The cathode assembly as described in (1) above, wherein the porous member is in a form selected from the group consisting of a plate, sheet, fibers, web, paper, net and sinter of any of these, and comprises at least a carbonaceous material and has a thickness of from 0.05 to 5 mm and a porosity of from 10 to 95%.
(4) A method of reactivating a cathode assembly, which comprises conducting electrolysis using the cathode assembly of (1) above until its activity decreases and then deposition a catalyst active in hydrogen generation on the porous member.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a view illustrating one embodiment of the cathode assembly according to the present invention.
FIG. 2 is a view diagrammatically illustrating a conventional process for the electrolysis of sodium chloride.
[Description of Symbols]
1 ion-exchange membrane
2 anode
3 cathode
4 porous member
DETAILED DESCRIPTION OF THE INVENTION
In the present invention, an electroconductive porous member having gas and liquid permeability is sandwiched between a cathode and an ion-exchange membrane. This arrangement prevents the cathode from contacting the membrane and hence from damaging the same.
For this purpose, the porous member should have a smooth surface so as not to damage the ion-exchange membrane even in contact therewith. Although spacers have been used for this purpose, such as nets made of synthetic fibers, the porous member for use in the present invention is electrically conductive unlike these spacers. Because of its conductivity and because it is in contact with the cathode, the porous member functions also as a conductive part of the cathode.
From the above standpoint, the porous member is preferably made of a corrosion-resistant material such as, e.g., titanium, nickel, zirconium, carbon, or silver. However, a carbonaceous material (especially, a graphitized material) is preferred from the standpoints of cost and chemical stability. An optimal form of the member is a sheet form having a thickness of from 0.05 to 5 mm and a porosity of from 10 to 95%.
It is, however, noted that although the porous member is in direct contact with the ion-exchange membrane, the cathode reaction proceeds on the cathode. This is because the cell has a high hydrogen overvoltage due to the material constituting the porous member.
Interposing the porous member between the ion-exchange membrane and the cathode prevents fine particles which have been generated as a result of cathode deterioration or dissolved ingredients which have been released from a nickel base from directly penetrating into the membrane. Furthermore, this structure inhibits fouling of the membrane by the particles or the nickel base.
Furthermore, when a catalyst which accelerates hydrogen generation is deposited on the porous member made of a conductive material such as those enumerated above, the porous member assumes the same potential as the cathode. This porous member can then function as part of the cathode.
Although the catalyst can be deposited on the porous member prior to conducting electrolysis, it is exceedingly preferred to deposit the catalyst at a time when the activity of the cathode has decreased as a result of electrolysis. This is because the cathode assembly including the cathode can thus be reactivated to advantageously minimize fluctuations of electrolytic voltage in the electrolysis equipment.
Where the porous member is made of carbon, it is possible to deposit a catalyst on the carbonaceous member as described above. A carbonaceous member having a catalyst, or having a compound of a catalyst element, deposited thereon can be formed by a pyrolysis method.
Preferred examples of the catalyst include platinum group metals such as silver, palladium, ruthenium, and iridium and alloys containing any of these metals. Examples thereof further include cobalt, a combination of cobalt with either a platinum group metal or an alloy thereof, and a combination of cobalt with an oxide of a platinum group metal.
One embodiment of the present invention will be explained below, but the invention should not be construed as being limited thereto.
FIG. 1 is a view illustrating one embodiment of the cathode assembly of the present invention. This catalyst assembly has an electroconductive porous member 4 permeable to gas and liquid sandwiched between a cathode 3 and an ion-exchange membrane 1.
The sandwiched porous member 4 is preferably made of a carbonaceous material (especially, a graphitized material) from the standpoints of cost and chemical stability. An optimal form of the member is a sheet form having a thickness of from 0.05 to 5 mm and a porosity of from 10 to 95%.
This sheet form material as the porous member 4, i.e., electrode sheet 4, preferably retains moderate porosity from the standpoints of passing an electric current through the cell and supplying or removing gases or liquids.
The electrode sheet 4 has regions made of a hydrophobic material and regions made of a hydrophilic material so as to enable the smooth movement of an electrolyte, etc. Preferably, these materials are scatteringly deposited on a catalyst or on a catalyst-bearing collector.
Examples of the hydrophobic material for use with the hydrophilic material include pitch fluoride, graphite fluoride, and fluororesins. Especially in the case of fluororesins, a burning step is preferably conducted at a temperature of from 200 to 400° C. in order to obtain satisfactory performance and evenness thereof.
Porous carbon materials generally possess hydrophilic groups on the surface, such as quinone, ketone. To ensure the hydrophilicity, thermal treatment in atmosphere is effective. In this case, it is better way to form metal or metal oxide layer by thermal decomposition of the coating solution having silver, titanium and etc., as written in Example 1.
The hydrophobic and hydrophilic regions each preferably extends continuously along the direction of the electrode thickness. Namely, each side of the electrode sheet is mottled with respect to hydrophilicity and hydrophobicity. This mottle preferably has the following constitution. The hydrophilic material which is exposed on one side of the electrode sheet to constitute hydrophilic spots thereon is mostly distributed so as to extend in the sheet thickness direction to form, on the opposite side, hydrophilic spots of the same pattern in almost the same positions. Also, the hydrophobic material which is exposed on one side of the electrode sheet to constitute hydrophobic spots is likewise distributed so as to extend in the sheet thickness direction to form, on the opposite side, hydrophobic spots of the same pattern in almost the same positions.
Where the cathode assembly having such a constitution has deteriorated in performance as a result of, e.g., the electrolysis of sodium chloride, and requires reactivation, a catalyst layer may be formed on the porous material as needed so that the cathode assembly can be continuously used. Preferred examples of the catalyst include metals such as platinum, palladium, ruthenium, iridium, silver, and cobalt and oxides of these metals.
The catalyst is powdered and mixed with a binder, e.g., a fluororesin, or with a solvent, e.g., naphtha, to prepare a paste, which is applied to the porous material to fix the catalyst thereto. Other usable catalyst deposition methods include a method in which a solution of a salt of a catalyst metal is applied to the base surface and the resultant coating is burned. Also usable is a method in which the salt solution is subjected to electroplating or to electroless plating in the presence of a reducing agent.
A preferred method for uniting the porous member 4 with an electrode main body is to superpose the porous material on a current collector or feeder (this corrector was used as a cathode in previous cell) and to press them together at a pressure of from 0.1 to 30 kg·f/cm 2 . If a sufficient bonding strength cannot be obtained by mere pressing, the porous member is preferably fixed to the feeder prior to assembling the cell. The sheet preferably has a thickness of from 0.1 to 5 mm and a porosity of from 10 to 95%.
When the electrode of the present invention is used for the electrolysis of sodium chloride, an optimal ion-exchange membrane is a fluororesin membrane from the standpoint of corrosion resistance. The anode 3 is preferably a titanium-based insoluble electrode which has an oxide of a noble metal and is called a DSA. This DSA is preferably porous so that it can be used in contact with the membrane. In the case where the electrode of the present invention needs to be in close contact with the membrane, they may be mechanically bonded to each other prior to assembling the cell. It is, however, sufficient to apply pressure on the electrode during electrolysis. The pressure is preferably from 0.1 to 30 kg·f/cm 2 . Preferred electrolysis conditions include a temperature of from 10 to 90° C. and a current density of from 20 to 100 A/dm 2 .
The present invention will be explained below in more detail by reference to the following Examples, but the invention should not be construed as being limited thereto.
EXAMPLE 1
A cell having an electrolysis area of 1 dm 2 (width, 5 cm; height, 20 cm) was used. An electroconductive porous member to be disposed between a membrane and a cathode was produced by applying an aqueous silver nitrate solution onto the surface of a carbon cloth (PWB, manufactured by Zoltek) as a base and then pyrolyzing the coating in an inert atmosphere at 350° C. to deposit silver particles on the surface of the porous member (10 g/m 2 ).
A nickel mesh (8 mm LW, 6 mm SW, 1 mm T; conventionally used as a cathode) was used as a cathode base. After the surface of the base was roughened and etched with hydrochloric acid, it was plated in a nickel electrodeposition bath containing a powdery RuO 2 catalyst dispersed therein to form on the base surface a deposit containing catalyst particles. This plated nickel mesh was used as a cathode.
A porous DSA made of titanium was used as an anode. Nafion 981 (manufactured by E.I. du Pont de Nemours & Co.) was used as an ion-exchange membrane. The electrodes and the porous member were brought into close contact with opposing sides of the ion-exchange membrane to fabricate an electrode cell having a cathode compartment and an anode compartment. Saturated aqueous sodium chloride solution was supplied as an anolyte at a rate of 4 ml/min, while pure water was supplied to the cathode chamber at a rate of 0.5 ml/min. A current of 50 A was passed through the cell at a temperature of 90° C. As a result, the cell voltage was 3.35 V, and a 32 wt % NaOH solution was obtained from the cathode outlet at a current efficiency of 96%. Electrolysis was conducted for 30 days under these conditions while suspending the operation for 1 day every week. Throughout the 30-day electrolysis, the cell voltage increased by 10 mV but the current efficiency of 96% was maintained. The cell was disassembled and the membrane was then analyzed. As a result, no deposition of nickel or the like was observed.
EXAMPLE 2
A cell was fabricated in the same manner as in Example 1, except that the carbon cloth (PWB, manufactured by Zoltek) was used as a porous member without undergoing any treatment. A current of 50 A was passed through the cell. As a result, the cell voltage was 3.40 V, and a 32 wt % NaOH solution was obtained from the cathode outlet at a current efficiency of 96%. Electrolysis was conducted for 30 days under the same conditions. Through the 30-day electrolysis, the cell voltage increased by 20 mV but the efficiency of 96% was maintained. The cell was disassembled and the membrane was then analyzed. As a result, no deposition of nickel or the like was observed.
Comparative Example
A cell was fabricated in the same manner as in Example 1, except that the porous member was omitted. A current of 50 A was passed through the cell. As a result, the cell voltage was 3.30 V, and a 32 wt % NaOH solution was obtained from the cathode outlet at a current efficiency of 96%. Electrolysis was conducted for 30 days under the same conditions. Through the 30-day electrolysis, the cell voltage increased by 50 mV and the efficiency decreased to 94%. The cell was disassembled and the membrane was then analyzed. As a result, the membrane was found to have partly browned, and the deposition of nickel was observed.
The present invention brings about the following effects. Since the cathode assembly provided by the present invention has an electroconductive porous member permeable to gas and liquid sandwiched between a cathode and an ion-exchange membrane, it can be an activated cathode assembly which eliminates the problems of prior art techniques and which can be used in an electrolytic cell operated at a high current density.
The electrolytic performance of the cathode assembly can be improved by depositing a catalyst on the porous member. This enables an existing cell to be operated at a high current density without undergoing any modification.
The present invention provides a significant economic advantage because an existing conventional cell is readily adapted to utilize the inventive cathode assembly. Interposing the porous material enables even contact between the ion-exchange membrane and the cathode, whereby the current distribution in a large cell is improved.
Furthermore, when the cathode assembly of the present invention exhibits deteriorated performance during the course of operation, it can be reactivated according to the present invention by merely inserting a porous material having a catalyst deposited thereon, unlike conventional cathodes which are generally reactivated by re-forming a catalyst layer thereon. Consequently, there is no need to conduct a reactivation step which is technically or economically difficult. Therefore, the present invention also has a high industrial value.
While the invention has been described in detail and with reference to specific embodiments thereof, it will be apparent to one skilled in the art that various changes and modifications can be made therein without departing from the spirit and scope thereof.
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A cathode assembly comprising a cathode, an ion-exchange membrane, and an electroconductive porous member permeable to gas and liquid sandwiched between the cathode and the membrane. The porous member may have, deposited on a part thereof, a catalyst active in hydrogen generation. The porous member preferably is in the form of a plate, sheet, fibers, web, paper, net, or sinter of any of these, and comprises at least a carbonaceous material and has a thickness of from 0.05 to 5 mm and a porosity of from 10 to 95%. Also disclosed is a method of reactivating a cathode assembly, which comprises conducting electrolysis using the cathode assembly until its activity decreases, and then depositing a catalyst active in hydrogen generation on the porous member.
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FIELD OF THE INVENTION
[0001] The present invention is generally related to techniques for programmed input output transfers over a switch fabric.
BACKGROUND OF THE INVENTION
[0002] Non-transparent bridging first appeared in the late 1990's in the form of the DEC (Digital Equipment Corp.) “Drawbridge”, later marketed by Intel Corp as the 21555 Bridge. Non-transparent bridging on PCI Express is described in several articles authored by technical staff at PLX Technology of Sunnyvale, Calif. (See “Using Non-transparent Bridging in PCI Express Systems” by Jack Regula, 2004; “Non-Transparent Bridging Makes PCI-Express HA Friendly,” by Akber Kazmi, EE Times, Aug. 14, 2003, the contents of each which is hereby incorporated by reference). Non-transparent bridging has also been described in a series of publicly available webcasts entitled “Utilizing Non-Transparent Bridging in PCI Express Base™ to Create Multi Processor Systems”, offered through TechOnline in October of 2003 (See Business Wire, Oct. 14, 2003 “PLX To Provide In-Depth Webcast October 21 on Implementing PCI Express In Multiprocessor Systems”, quoting Jack Regula)
[0003] Non-transparent bridging provides mechanisms for programmed input output access between two nodes based on memory address translations and address routing. A non-transparent bridge may have an intelligent device on both sides of a bridge, each with its own independent address domain. In a non-transparent bridging environment, there is a need to translate addresses that cross from one memory space to another. However, the inventors of the present application have recognized that the address-based approach of non-transparent bridging has problems in regards to scalability, performance, and manageability, especially for Peripheral Component Interconnect (PCI) Express switch fabrics and PLX Technology's implementation of Express Fabric. Therefore, in view of these drawbacks, a new approach is desired to implement tunneled window connections for PCI Express Fabric.
SUMMARY OF THE INVENTION
[0004] Tunneled window connections are utilized in a switch fabric to perform programmed input output transfers. The window connections are based on global IDs.
[0005] In one implementation, a method of performing a programmed input output transfer in a PCI Express Fabric is disclosed that includes defining visibility of at least one host end point to other host end points of a switch or switch fabric, including defining windows on these host endpoints and connections between them. Tunneled PIO transfers between connected windows by routing the PIO transfer between window segments of host end points based on a global ID.
[0006] In another implementation, a method of performing a programmed input output (PIO) transfer in a PLX Express Fabric is disclosed in which a management entity defines tables in a global management end point of a switch and in host end points of the switch, the tables defining mappings between window segments of the initiating node and windows of the target node for routing transactions based on a global ID. The method includes performing a transaction between two end points of the switch fabric by routing the transaction based on a global ID
[0007] In another implementation, a PLX Express Fabric switch is disclosed. The switch includes a port for connection to a management entity or an internal management entity. The switch includes a global end point having a segmented base address register and a segment mapping table. A set of host end points is communicatively coupled to the global end point manager, each host end point having ingress and egress lookup tables. The segment mapping table and the ingress and egress lookup tables are programmed to define window connections between end points for programmed input output transactions.
BRIEF DESCRIPTION OF THE DRAWINGS
[0008] FIG. 1 illustrates a management CPU view of tunneled window connections in accordance with an embodiment of the present invention.
[0009] FIG. 2 illustrates the use of a segment mapping table to direct incoming traffic to a tunneled window connection host end point in accordance with an embodiment of the present invention.
[0010] FIG. 3 illustrates outgoing traffic from a tunneled window connection host end point in accordance with an embodiment of the present invention.
[0011] FIG. 4 is a flowchart for the access of a window in a host's memory by the MCPU. It describes a tunneled window connection between a management endpoint and a tunneled window connection host end point in accordance with an embodiment of the present invention.
[0012] FIG. 5 is a flowchart of a tunneled window connection host end point to another host end point in accordance with an embodiment of the present invention.
DETAILED DESCRIPTION
[0013] The present invention is generally directed to an application of a Tunneled Window Connection (TWC) mechanism for programmed I/O transfers (PIO) between nodes of a switch fabric using a connection oriented transfer mechanism based on ID routing through a global ID space.
[0014] In one embodiment, registers at initiator and target nodes define a connection between memory address apertures at both nodes so that load/store transfer commands can be tunneled through the switch fabric between initiator and target nodes with security, using ID routing. Multiple such connections can be stored at both initiator and target nodes and organized into tables. Connections are unidirectional tunnels for the transport of a memory request packet, which can be for a read or a write transfer, from an initiating node to a target node. Typically, each window at the initiator node is a segment of a Base Address Register (BAR) which is connected to an arbitrarily located window in the target node. The registers at the initiator node include the ID route to the target node. The registers at the target node include the ID of the initiator node at the other end of the connection, for use in access permission checking. Thus, the TWC mechanism improves security and provides other benefits, such as eliminating the burden of performing conventional memory address translations for PIO transfers. An exemplary application is in a PLX Express-Fabric™ environment, although it will be understood that other fabric environments are contemplated. The PLX Express-Fabric™ environment is promoted by PLX Technology, Inc. of Sunnyvale, Calif. and is described in white papers and other published papers describing the ExpressFabric® initiative, including the following articles incorporated by reference: “PLX Looks to Bring PCIe Fabric to Market,” HPCwire, November 2012; “What Else Can PCI Express Do?”, RTC Magazine, November 2012; “PLX Preps PCI Express Fabric amid Server Debate,” EE Times, September 2012; and “PCI Express Fabric: Rethinking data center architectures,” Embedded Computing, August 2012.
[0015] In one embodiment, the Tunneled Window Connection mechanism acts as an interface to a switch fabric for a compute node that allows it to transfer data with other compute nodes on the fabric by standard load and store computer instructions without the need for address translation. In one embodiment, the TWC mechanism employs an indexed window access for the use of load and store instructions by a processor instead of a direct memory access mechanism, thus reducing software overhead and latency for transfers of small amounts of data at a time.
[0016] The TWC mechanism provides a means for registering memory buffers at both initiator and target nodes, and allowing only a single connected initiator to transfer data to or from the buffer. In one embodiment, the global ID of the target is registered with the initiator as packets transferred between the two nodes are routed by ID instead of by address. Because ID routing is used, it's not necessary to translate the address in order to route the packet to its destination. The global ID of the initiator is registered with the target so that other nodes may be prevented from transferring data with the buffer, thus providing security for the transfer. The location of the target buffer in the target's address space is also stored in the target's registry and used when a transfer request with a matching connection number is received and security checks are passed. Although ID routing is used in the preferred embodiment, multiple routing mechanisms other than address routing are contemplated.
[0017] FIG. 1 illustrates a PCI Express Fabric switch, showing a management CPU (MCPU) 105 view of a tunneled window connection (TWC) between end points of a set of nodes in a PCI Express switch fabric, in accordance with an embodiment of the present invention. The MCPU 105 is coupled to a PCI-PCI Compliance bridge 120 , which in one embodiment, is made via an internal virtual bus (IVB) 115 and a virtual PCI-PCI bridge 110 . It will be understood that other conventional hardware and processor support may be provided to support the operation of the switch.
[0018] In one embodiment, a global end point (GEP) management unit 125 is coupled to the PCI-PCI Compliance bridge 120 . In one implementation, the GEP is a full type zero endpoint and includes registers to support creating entries to define the window connections. The GEP management endpoint is to manage the switch itself, and internal DMA controllers in addition to serving as the TWC management end point. The management end point of each switch is thus the management end point for the TWC (TWC-M). A segmented base address register (BAR) (e.g. a BAR2 in one implementation) is provided to support the tunneled window connection function, where each individual segment of the BAR is mapped to the TWC-H of one of the host ports of the switch.
[0019] A set of hosts 1 to N is illustrated, each having corresponding host ports. Each of the host ports in the Express Fabric has a TWC host end point (TWC-H) 130 , which is communicatively coupled via the data path of the switch to GEP management unit 125 . The management policy, as set by a system administrator via a management entity (or EEPROM settings), will dictate if the TWC-H end point is visible to a particular host port or not. A virtual PCI to PCI bridge interface provides a connection to an individual host, where an individual host computing device has associated computing hardware and host driver 150 and host software application 155 .
[0020] In one embodiment, the TWC Management of GEP management unit 125 , as well as TWC host end points 130 , have a single segmented (or windowed) BAR2 (and BAR3 for 64 bit BARs). Each of these segments (or more than one of them) can be pointed towards a window on a remote node.
[0021] In one embodiment, the MCPU, acting as a management entity, configures a connection between an outgoing address window at an initiating node, and an incoming address window at a target node, by configuring a table entry at each of the initiator and target nodes. The MCPU has associated software applications 107 and additionally, there may also be a management driver 127 . In one embodiment, the connection process is initiated when an application on one node needs to exchange data with another node. The two nodes may exchange messages via a conventional mechanism (e.g., an application specific protocol over the switch fabric or any other available fabric; using mailboxes or scratch registers or broadcasts over any fabric/transport), and agree to the data exchange using specified or negotiated initiator and target connection numbers. This connection mechanism can also be arbitrated and finalized by a management entity.
[0022] In one embodiment, an initiator (node) performs a data transfer by executing a load or store operation using an address that maps to the Tunneled Window Connector (TWC) portal into the switch fabric. When the address is in the range that maps through the portal, the TWC hardware extracts a connection number from the address, looks up the target global ID (GID) and connection number in a table, and modifies the packet for transfer through the fabric in one of the following ways:
1. Convert the memory read/write request packet to a new packet with ID-routed Vendor Defined Message header with target node connection number, offset within window and the target's ID as fields. This packet can be ID routed through a PCIe switch fabric to the target node; and 2. The TWC can pre-pend the original packet with an ID routing prefix. In PLX Express Fabric, a PCIe Vendor Defined End to End prefix is used. This prefix contains the Target's global Domain and BUS numbers, sufficient subset of the Target GID to route to it, plus the Source's Domain number which is needed for the return ID route, if the packet is a read request. When using the prefix un-needed bits of the address may be discarded and replaced by the target's connection number.
[0025] If the initiator (node) and target (node) are in different Express Fabric Domains, then the ID routing prefix described above must be pre-pended to the packet even when using the Vendor Defined Message option described above to provide the Destination Domain for use in ID routing.
[0026] In one embodiment, the initiator's connection table entry is stored at an index corresponding to the initiator's connection number. It contains the global ID of the target node and the target's connection number. The target node's connection table entry is stored at the index corresponding to its connection number. It contains the initiator's global ID, a set of access permissions and a base address that specifies the location of the registered buffer in its memory space. The buffer may be configured for read only access, write only access, read and write access by any fabric node, or by only the node whose global ID is registered in the table entry.
[0027] In one embodiment, the initiator's request packet arrives at the target node. At this point, the ID routing prefix, if any, may be discarded. The target connection number is extracted from the header and used to retrieve the registered information. First, access permissions are checked. If the permission checks fail, the request is rejected by, in a PLX ExpressFabric™, treating it as an unsupported request (UR). If the checks are passed, then the target buffer base address is retrieved from the table and added to or concatenated with the buffer offset carried in the request packet header. The composite address is then used as the address in a standard PCIe memory request packet that is forwarded from the egress of the target host port of the switch to the target host itself.
[0028] FIG. 2 illustrates the use of a Segment Mapping Table to associate each segment of the GEP BAR to one of the TWC-H endpoints of the switch. In one embodiment, the MCPU, and only the MCPU, uses address routing to initiate load/store transfers through host port TWC-H endpoints. The Segment Mapping Table supports these transfers by mapping the address range of each GEP BAR segment to a specific host port. On the TWC Management end point, the incoming address routed transfers are routed to individual TWC-H end points on the same switch by a Global Segment Mapping Table. The Global Segment Mapping Table allows an individual TWC management end point BAR2 segment to point to a specific TWC Host end point. In one implementation, this segment always goes to the Egress T-LUT entry 0 of the remote TWC Host end point as a default. That means a posted write by the TWC Management end point (same as GEP end point) BAR2 from the MCPU will land in the system memory allocated to the Egress A-LUT entry 0 of a host port for that segment.
[0029] FIG. 3 illustrates tunneled window connections between the Ingress T-LUT of a TWC-H endpoint 130 -H and the Egress T-LUT of two other TWC-H endpoints 130 - n and 130 - m potentially located in different switch chips elsewhere in the fabric, in accordance with embodiments of the present invention. Referring to FIG. 3 , in one embodiment, the windows, connected via ID-routed tunneling, are managed through the Ingress and Egress T-LUT (Tunnel LUT) entries in each TWC Host end point. The routing through the fabric between the switch containing the initiating node and the switch containing the target node is based on ID routing in a global ID space for TWC (unlike the address routing for the earlier technology of Non Transparency).
[0030] As illustrated in FIG. 2 , in one implementation, an individual TWC-H end point has an Egress T-LUT table 205 and local system memory blocks. In this example, the Egress T-LUT has 0, 1, 2, . . . n window entries, each corresponding to an entry in the T-LUT. The target connection number, which is part of the initiator's transfer request packet, points to the T-LUT entry number to be used to complete the transfer.
[0031] In one implementation, each TWC Host end point 130 does not share/have any global address range for address routing. A TWC Host end point 130 can only be reach from another TWC Host end point through a tunnel that targets one of the windows it exposes, using the global ID of that TWC Host end point. Note however as described earlier with regard to FIG. 2 , that the MCPU, and only the MCPU, can target TWC host end points using address routing.
[0032] FIG. 3 illustrates traffic initiated by a TWC Host End point 130 - x that targets TWC Host End points 130 - n and 130 - m, respectively. By programming its Ingress T-LUT 190 , each TWC Host end point's BAR2 can be segmented and pointed to various windows of remote nodes in the fabric, such as nodes 130 - n and 130 - x . The ingress T-LUT 190 is used to access any other TWC Host end point in the fabric, but cannot be used to access the MCPU (TWC Management/GEP end point memory). To access MCPU memory, the MCPU can set up an address trap for one of the Ingress T-LUT entries to map directly to the MCPU memory space that is allocated for this purpose.
[0033] In some embodiments, additional drivers are used to support the TWC mechanism. In particular, TWC host drivers and a TWC management driver may be utilized to aid in supporting the TWC mechanism.
[0034] FIG. 4 is a flowchart illustrating a TWC host end point to another TWC host end point. In block 405 , an application on one node requests MCPU to setup a TWC connection to another node. In block 410 , the MCPU TWC-M driver registers the connection in the TWC-H at both nodes, resulting in a local connection ID at each end, a destination ID at the initiating end, and an initiator ID at the target end of the connection. At block 415 , the MCPU TWC-M driver returns the initiator connection index and window size to the requesting application. In block 420 , the application does a load/store to the target node window, resulting in a PCIe memory request packet entering the initiator's switch. In block 425 , the switch HW extracts the initiator connection number from the address of the PCIe request TLP generated by the application, and uses it to index ingress T-LUT to get target host ID and target connection number. In block 430 , the switch pre-pends the PCIe request packet with an ID routing prefix containing the target host's ID and embeds the target connection number in the request's address just above the field of the address. In block 435 , egress logic in the target host port indexes the egress T-LUT with the connection number in the request packet to get the window base address and security information and performs the security checks. In block 440 , if the security checks pass, the egress logic adds the offset contained in the original request packet's address to the window base address to get the final destination address. It then replaces the address in the request packet with the destination address and forwards the packet to the host. In block 445 , if the packet is a read packet, a completion with the requested data will return from the host and to be ID routed back to the MCPU.
[0035] FIG. 5 is a flowchart illustrating the TWC management to a TWC host end point data path. In block 510 , an application on the MCPU requests a connection to a host port. In block 515 , the TWC management driver (TWC-M) prepares a target host egress T-LUT entry 0 for use by the MCPU and returns a window base address and size to the application. In block 520 , the application does a load/store to an address within the window returned by the TWC management driver. In block 525 , the application's memory request packet is address routed to the switch containing the target host port. In block 530 , routing logic in the ingress of that switch decodes the GEP BAR segment in which the address hits. It then uses this segment number to index a segment mapping table to get the host port number and forwards the packet to that port.
[0036] For implementing a remote PIO memory access using a Tunneled Window Connection to the remote node, and routing that access by using the remote node ID instead of using remote addresses, has several benefits in comparison to Non Transparent Bridging. One benefit of this method is that addresses don't need to be translated in order to be used for address routing through the fabric, unlike conventional non-transparent bridging.
[0037] Another benefit is that remote node addresses are also isolated, as the routing is only based on the remote node ID. Packets are routed through the PCIe fabric using ID routing, instead of address routing used by non-transparent bridging.
[0038] Moreover, the ID routing is scalable to hundreds or thousands of nodes without any system limitations.
[0039] Additionally, making these connections under the control of a management entity provides further security. Once it is secured by a management entity, a rogue TWC end point driver cannot access another host's memory. The security checks implemented by the management entity, together with hardware ID checking, prevent a rogue endpoint driver from accessing the memories of other hosts.
[0040] The security mechanisms apply at both the sending and receiving sides. The sender can target a remote node only if enabled/allowed to do so. The receiver can verify and authenticate the received data to make sure only an authorized sender is sending this data. The receiver can report security violations if it receives unsolicited data from a rogue node.
[0041] The TWC mechanism comes with increased security and robust features which cannot be applied on non-transparent bridging. This mechanism also supports the use of transfers across multiple PCIe BUS number Domains.
[0042] While embodiments of the invention have been described in the context of ExpressFabric to illustrate aspects of the invention, it will be understood that the invention is not limited to ExpressFabric. That is, the TWC mechanism can be implemented on PCI Express or any other fabric.
[0043] While the invention has been described in conjunction with specific embodiments, it will be understood that it is not intended to limit the invention to the described embodiments. On the contrary, it is intended to cover alternatives, modifications, and equivalents as may be included within the spirit and scope of the invention as defined by the appended claims. The present invention may be practiced without some or all of these specific details. In addition, well known features may not have been described in detail to avoid unnecessarily obscuring the invention. In accordance with the present invention, the components, process steps and/or data structures may be implemented using various types of operating systems, programming languages, computing platforms, computer programs, and/or general purpose machines. In addition, those of ordinary skill in the art will recognize that devices of a less general purpose nature, such as hardwired devices, field programmable gate arrays (FPGAs), application specific integrated circuits (ASICs), or the like, may also be used without departing from the scope and spirit of the inventive concepts disclosed herein. The present invention may also be tangibly embodied as a set of computer instructions stored on a computer readable medium, such as a memory device.
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Tunneled window connections are utilized in a switch fabric to perform programmed input output transfers. The window connections are based on global IDs. A management entity may enforce the tunneled window connections, improving security.
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CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] The present application claims benefit of the filing date of U.S. Provisional Patent Application No. 61/287,793, filed Dec. 18, 2009, the disclosure of which is incorporated herein by reference.
FIELD OF THE INVENTION
[0002] The field of this invention pertains to a bone cement for bone filler applications and in the preparation of such cement. More specifically, the invention relates a post irradiation shelf-stable dual paste direct injectable bone cement precursor systems suitable for implanting within the human body and methods of making same.
BACKGROUND OF THE INVENTION
[0003] Calcium phosphate based cements (CaPC) have been used as bone substitutes and bone grafts for nearly twenty years. In the 1980s, the research was focused on developing a formulation that was biocompatible for the intended use of clinical applications. These CaPC formulations have historically been provided in the form of a powder and liquid system, which upon mixing becomes a paste and goes through a partial dissolution that initiates a precipitation reaction resulting in the setting of the cement. Often such cements are based on an acid-base reaction to form a salt which usually takes the form of the calcium phosphate phase identified as hydroxyapatite or brushite.
[0004] Most of the presently available calcium phosphate precursor cement formulations are still a powder/liquid system wherein the powder and the liquid components are separately packaged and only to be combined prior to use at time of surgery. The mixing is accomplished by either (a) manual mixing, or (b) use of a mechanical based mixing system provided in a commercial product. However, both approaches have some shortcomings. The manual system is sometimes perceived to be time consuming, and user dependent/sensitive. The custom designed mechanical systems aim to provide a more satisfactory user experience by providing consistency and reproducibility for the end user, but are still considered to be cumbersome, difficult to use and cost ineffective.
[0005] Accordingly, there have been studies reported with the aim to develop premixed, self-hardening, cement pastes. For example, U.S. Pat. No. 6,793,725 describes a self-hardening calcium phosphate based bone cement paste that is mixed with liquid glycerol, hydroxypropyl methylcellulose and sodium phosphate. This premixed paste formulation allegedly remains stable over a period of time and hardens only when delivered to a desired site in a human body. This premixed paste formulation, however, does not exhibit a good washout resistance when it is applied to an open wet field in a human body, and is therefore limited in utility.
[0006] U.S. Patent Publication No. 2006/0263443 also discloses a premixed self-hardening calcium phosphate based bone cement paste containing a gelling agent, such as hydroxymethyl cellulose, carboxymethyl cellulose, chitosan, collagen, gum, gelatin and alginate, to enhance paste cohesiveness and washout resistance. This type of cement, allegedly possesses excellent physical properties, but it is also limited in utility since cement hardening in the interior of the cement mass is slow under some clinical bone grafting conditions, for instance, wherein the amount of water available from the tissue is limited, or wherein the interior of the cement is more than several millimeters away from the nearest graft-tissue interface.
[0007] U.S. Patent Publication No. 2007/0092580 teaches a self-setting dual phase cement precursor system composed of a first and second discrete containers, at least one of which is aqueous. The cement formed by combining these two phases, however, do not have a long-term shelf life, as the phases in each of these two pastes packaged in separate containers tend to destabilize/separate during storage. This is especially true after the dual paste system is sterilized using gamma radiation. Therefore, this formulation also is limited in utility.
[0008] The present invention aims at responding to the currently unanswered user need for providing a premixed dual paste injectable bone cement precursor system that is shelf stable even after it is sterilized using gamma radiation for in vivo usage, and that rapidly sets as a biocompatible bone cement possessing excellent physical properties when combined.
SUMMARY OF THE INVENTION
[0009] In one aspect of the invention, the invention relates to a rapid setting bone cement precursor system that is presented in the form of two shelf-stable pastes that are held in separate containers during product transport and storage. When the product is used during surgery, these pastes inject to a site of application through a specially designed static mixing device by the action of applied injection force. When the two pastes are mixed, they start to react to each other while injecting out. The reaction is continued at the site of application in the body environment, wherein the mixture of pastes converts into a bone cement in a specified time. The resulting cement is highly biocompatible, osteoconductive, injectable and bioresorbable that is useful in connection with bone repair procedures, for example, in the craniomaxillofacial, trauma and orthopedic areas.
[0010] In another aspect of the invention, the at least two pastes containing bone cement precursors are shelf stable even after terminal sterilization, e.g. using gamma irradiation, for in vivo use.
[0011] In yet another aspect of the invention, the invention provides a post irradiation shelf-stable product with greater than 3 month, preferably 6 month, and most preferably greater than 1 year of shelf life.
[0012] It is also an aspect of the invention to provide a stable and injectable bone cement precursor system comprising an acidic aqueous paste and an alkaline non-aqueous paste. The pastes themselves are not cements, but they may be combined to form a biocompatible bone cement that is useful in connection with bone repair procedure.
[0013] In a preferred embodiment, the acidic aqueous paste and the alkaline non-aqueous paste are designed to withstand terminal sterilization, such as gamma radiation, and still meet the long-term shelf life stability and injectability when kept separate, and reactivity to each other when mixed to set and form hydroxyapatite-based bone cement in a specified time. The resulting bone cement has superior biocompatibility and mechanical properties exhibiting excellent wet field wash out resistant properties.
[0014] Terminal sterilization, such as gamma irradiation, and pH have dramatic effect on the structural stability of polymer additives which may be used in these two pastes as they are either degraded into low molecular weight species or cross linked into polymeric gels which alters the viscosity. Accordingly, in order to provide a post irradiation shelf-stable bone cement precursor system, the polymer additives in accordance with an aspect of the present invention must be able to survive the terminal sterilization and extreme pH conditions.
[0015] Applicants have found that post irradiation stability is achieved by using synthetic polymers rather than natural cellulose based polymers as paste stabilizing agents in the acidic aqueous paste. Without wishing to be tied to a theory, it is believed that the cellulose polymers are susceptible to degrade into low molecular weight species in acidic aqueous medium during terminal sterilization, thereby affecting the viscosity of the paste during storage. The preferred polymer based stabilizing agent for the acidic aqueous paste is polyvinyl pyrrolidone (PVP) and polyethylene glycol (PEG).
[0016] With respect to the alkaline non-aqueous paste, Applicants have found that the use of either the natural when preferentially used in combination of antioxidants or synthetic polymers does not affect the alkaline non-aqueous paste's long term storage stability even after it is exposed to the terminal sterilization process, such as gamma irradiation. The preferred paste stabilizing agent for the alkaline non-aqueous paste is polyethylene glycol (PEG), cellulose-based polymer, such as hydroxyethylcellulose (HEC) when preferentially using an antioxidant such as thioglycerol.
[0017] According to an aspect of the invention, the acidic aqueous paste composition comprises at least one acidic calcium phosphate mineral, at least one synthetic polymer based paste stabilizing agent, a pH buffering agent and a humectant.
[0018] The at least one acidic calcium phosphate mineral is preferably monocalcium phosphate monohydrate (MCPM), monocalcium phosphate anhydrous (MCPA), dicalcium phosphate dehydrate (DCPD), and dicalcium phosphate anhydrous (DCPA).
[0019] The at least one synthetic polymer-based paste stabilizing agent is, preferably, polyvinyl pyrrolidone (PVP) and polyethylene glycol (PEG).
[0020] The pH buffering agent is, preferably, citric acid, tartaric acid and malic acid and their salts, including trisodium citrate and disodium tartarate. The most preferred pH buffering agent is citric acid.
[0021] The humectant is, preferably, glycerol and propylene glycol.
[0022] In a preferred embodiment, the acidic paste composition comprises monocalcium phosphate monohydrate (MCPM) and dicalcium phosphate anhydrous (DCPA), citric acid, water, glycerol, PVP and PEG.
[0023] According to an aspect of the invention, the alkaline non-aqueous paste comprises at least one basic calcium phosphate mineral, at least one paste stabilizing agent, a surfactant and a solvent.
[0024] The at least one basic calcium phosphate mineral is, preferably, β-tricalcium phosphate, α-tricalcium phosphate, tetracalcium phosphate, oxyapatite, hydroxyapatite or calcium-deficient hydroxyapatite. The most preferred at least one basic calcium phosphate mineral is tetracalcium phosphate (TTCP).
[0025] The at least one stabilizing agent used in the alkaline non-aqueous pastes, is preferably either natural with or without an antioxidant or synthetic polymer based. Without wishing to be bound to a theory, it is believed that in a water-free paste system, both the natural and synthetic polymers survive; therefore, providing paste stability during terminal sterilization and storage. The preferred at least one stabilizing agent is polyethylene glycol (PEG), cellulose-based polymer, such as hydroxyethylcellulose (HEC) and the preferred at least one antioxidant for use with the cellulose based polymer is thioglycerol.
[0026] The surfactant is, preferably, glycerol monostearate, lecithin, phospholipids, glycerol distearate, polyethylene glycol distearate, block polymers of PEG-PPG-PEG or PPG-PEG-PPG, Tween, Span, any polysorbate fatty acid ester or sorbitol esters. The most preferred surfactant is polysorbate 80 (Tween 80).
[0027] The solvent is, preferably, one or more of the following; glycerol, thioglycerol, ethanol, propanol, and propylene glycol. The most preferred solvents glycerin and propylene glycol.
[0028] In a preferred embodiment, the alkaline non-aqueous paste comprises tetracalcium phosphate, polyethylene glycol, polysorbate 80, and propylene glycol.
[0029] In accordance with another aspect of the invention, the alkaline non-aqueous paste comprises a bimodal mean particle size distribution of at least one basic calcium phosphate mineral in order to maximize the paste stability and cement reactivity. More preferably, the alkaline non-aqueous paste with a bimodal mean particle size distribution of TTCP was demonstrated to produce a bone cement that is superior than when a single mode mean particle size distribution of TTCP in the alkaline non-aqueous paste, when mixed with the acidic aqueous paste.
[0030] One aspect of the present invention is a calcium phosphate composition produced by mixing the acidic aqueous paste and the alkaline non-aqueous paste of the present invention. In an embodiment, the calcium phosphate cement is rapid setting. In another embodiment, the calcium phosphate cement is injectable. In yet another embodiment, the calcium phosphate cement is rapid setting and injectable.
[0031] One aspect of the present invention is to ease the mixing and application of a CaPC in surgery. The approach taken here has been to completely eliminate the need for the three separate steps whereby the user must (i) mix the powder and liquid components to form a cement paste, (ii) transfer the cement paste into a delivery syringe and (iii) inject the cement paste into a bone cavity. Instead, the intention of this invention is to simplify by combining these three separate steps into one whereby the user is provided with a system that eliminates the need for transfer of the cement paste into a syringe system and concurrently and homogeneously mixes the components during the injection step.
[0032] Yet another aspect of the present invention is to a method of making a post irradiation shelf-stable dual paste direct injectable bone cement precursor compositions comprising mixing at least one synthetic polymer based paste stabilizing agent, a pH buffering agent, and water; adding at least one acidic calcium phosphate mineral to the mixture of the at least one synthetic polymer based paste stabilizing agent, the pH buffering agent and water to form an acidic aqueous paste; and mixing at least one paste stabilizing agent, a surfactant, and a solvent; adding at least one basic calcium phosphate mineral to the mixture of the at least one paste stabilizing agent, the surfactant, and the solvent to produce an alkaline non-aqueous paste.
[0033] In accordance with the invention, the method may further comprise a step of storing the acidic aqueous paste in a container; storing the alkaline non-aqueous paste in another container; and providing a device which would inject the pastes concurrently from the separate containers to a static mixing device so that said a blended paste of said acidic aqueous paste and said alkaline non-aqueous paste can inject to a site of application by the action of applied injection force.
[0034] One aspect of the invention is to provide a kit comprising a dual paste injectable cement precursor system comprising two holding chambers, wherein the first holding chamber comprises an acidic aqueous paste and the second holding chamber comprises an alkaline non-aqueous paste, and a mixing device where the acidic aqueous paste and the alkaline non-aqueous paste are mixed and injected to a site of application by the action of applied injection force.
[0035] Another aspect of the invention is to provide a device for a dual paste injectable bone cement precursor system comprising: a syringe body and a static mixing tip, wherein the syringe body comprises a first holding chamber containing an acidic aqueous paste comprising at least one acidic calcium phosphate mineral, at least one synthetic polymer-based paste stabilizing agent, a pH buffering agent and a humectant, and a second holding chamber containing an alkaline non-aqueous paste comprising at least one basic calcium phosphate mineral, at least one paste stabilizing agent, a surfactant and a solvent, and the static mixing tip comprises a structure which allows the two pastes to be blended and to be applied to a desired site. In one embodiment, a device is a dual barrel syringe system having a static mixer wherein the acidic aqueous paste of the present invention and the alkaline non-aqueous paste of the present invention are stored in a one to one ratio in each barrel, and be mixed in the static mixer to be blended and initiate setting and be applied to a desired site. In another embodiment, the device and/or the dual barrel syringe system maintains a seal to reduce moisture and air leaks to ensure shelf life protection.
BRIEF DESCRIPTION OF THE DRAWINGS
[0036] FIG. 1 is a graphical overview of the dispersion analysis results of the acidic aqueous pastes and alkaline non-aqueous pastes of the present invention.
[0037] FIG. 2 is a graphical overview of the analysis results of wet field tests of the formulation of the present invention comprising the acidic aqueous paste E of Example 2 and the alkaline non-aqueous paste D1 of Example 3 before and after the aging test.
[0038] FIG. 3 is a graphical overview of the analysis results of injectability tests of the formulation of the present invention comprising the acidic aqueous paste E of Example 2 and the alkaline non-aqueous paste D1 of Example 3 before and after the aging test.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0039] Throughout the entire specification, including the claims, the word “comprise” and variations of the word, such as “comprising” and “comprises,” as well as “have,” having,” “includes,” “include,” and “including,” and variations thereof, means that the named steps, elements or materials to which it refers are essential, but other steps, elements, or materials may be added and still form a construct with the scope of the claim or disclosure. When recited in describing the invention and in a claim, it means that the invention and what is claimed is considered to what follows and potentially more. These terms, particularly when applied to claims, are inclusive or open-ended and do not exclude additional, unrecited elements or methods steps.
[0040] The term “cement” herein is used interchangeably with cement formulation, cement composition and bone cement.
[0041] The term “between” as used in connection with a range includes the endpoints unless the context suggests otherwise.
[0042] The term “long term shelf-life” or “shelf-stable” herein means that the cement precursors(s), such as calcium phosphate mineral(s), and other powder materials in a paste will not separate out from the liquid when exposed to real time and accelerated aging conditions and will set when mixed with the corresponding acidic aqueous/alkaline non-aqueous paste to form a bone cement after the dual paste system has been stored in a sealed container for a predetermined period of time, for at least 1.5 months, preferably 3 months, and more preferably for at least 6 months and most preferably more than 1 year according to the accelerated aging test described in details below.
[0043] The term “alkaline non-aqueous paste” as used in accordance with the present invention herein means that this paste includes a non-aqueous solvent such as glycerol or propylene glycol and a basic calcium phosphate mineral, and that the paste is able to be miscible with the acidic aqueous paste. It is contemplated that in an alkaline non-aqueous paste, there may be trace amounts of moisture present, such as moisture that is unavoidably present notwithstanding reasonably prudent steps to exclude such moisture. The alkaline non-aqueous paste itself is not a cement, in that the paste itself does not set to form a hard material in ordinary use. Rather, when the alkaline non-aqueous is combined with the acid aqueous paste, a cement is formed thereby.
[0044] The term “acidic aqueous paste” as used in accordance with the present invention herein means that this paste includes water and an acidic calcium phosphate mineral, and that the paste is able to be miscible with the alkaline non-aqueous paste. The acidic aqueous paste itself is not a cement, in that the paste itself does not set to form a hard material in ordinary use. Rather, when the acidic aqueous paste is combined with the alkaline non-aqueous paste, a cement is formed thereby.
[0045] The term “injectable” as used in accordance with the present invention herein means that the acidic aqueous paste which is held in one container, and the alkaline non-aqueous paste which is held in a separate container may be delivered to the site of application through a cannula, a needle, a catheter, a syringe or a specially designed static mixing device by the action of an applied injection force. This injection force is tested at an ambient temperature of between 18° C. to 22° C. as set out in Examples 1, 2 and 3 below, and does not exceed 225 N, and more preferably 150 N to allow ease of injectability for the end user.
[0046] The term “rapid setting” as used in accordance with the present invention herein means that when the acidic aqueous paste and the alkaline non-aqueous paste are mixed and delivered to a defect site, the mixture forms a cement in about 10 minutes or less, preferably in about 9 minutes or less, most preferably in about 8 minutes or less when the defect temperature is about 32° C.
[0047] The term “set” as used in accordance with the present invention herein means that the penetration force measured according to the wet field penetration resistance test described in details below is preferably greater than 10 MPa, more preferably greater than 20 MPa and most preferably greater than 24 MPa.
[0048] The term “biocompatible” when used in conjunction with a cement contemplates a cement that is not rejected by soft tissue or hard tissue when used in vivo in the intended application.
Kit
[0049] Preferably, the system is provided in the form of a kit, the kit including the dual paste injectable cement precursor system comprising an acidic aqueous paste and an alkaline non-aqueous paste in separate moisture impermeable holding chambers (e.g. glass, cyclic olefin copolymer plastic, etc) throughout the products shelf life and an appropriate mixing device. The mixing device may be conventional, or may otherwise be a device suitable for use in conjunction with the cement precursor systems taught in the art.
[0050] Preferably, a device having a syringe body with a static mixing tip, the mixing tip comprising an auger-like structure that allows the two pastes to be blended rapidly and subsequently to be applied to the desired area is used in accordance with the invention. The syringe body may include a region that serves as the container for separate pastes, by providing separate holding chambers for the acidic aqueous paste and the alkaline non-aqueous paste.
[0051] Any suitable container may be used in conjunction with the invention, and thus, for instance, the container may be any appropriate box, or bag, or package.
Cement Precursors in the Pastes
[0052] The cement precursors may be any material suitable for use in forming a biocompatible cement. Numerous cement chemistries may be used in conjunction with the invention. In a preferred embodiment, a calcium phosphate cement is employed. In one embodiment, a calcium phosphates cement may be formed by combining at least one calcium phosphate material in at least one of the two precursor pastes. In another embodiment, a calcium phosphate cement, for example, hydroxyapatite, is formed by combining at least two dissimilar calcium phosphate materials present respectively in the two precursor pastes.
[0053] The pastes need not include only a single calcium phosphate material, and thus, for instance, the pastes each may include multiple calcium phosphate materials, and some of the third calcium phosphate material may be present initially in either or both of the pastes.
[0054] Generally, it is preferred that the Ca/P ratio ranges from 0.5 to 2.0 in each paste. In some embodiments, particularly when it is desired to form hydroxyapatite, one of the pastes includes a calcium phosphate in which the Ca/P ratio is less than 5/3, and the other includes a calcium phosphate compound in which the Ca/P ratio is greater than 5/3. The Ca/P ratio in hydroxyapatite is 5/3, and it is believed that providing calcium and phosphate in both greater and lesser amounts will drive formation of hydroxyapatite. It is not necessary to employ two such pastes, especially if a setting accelerator is used. In some embodiments, the Ca/P ratio in one of the pastes is equal to 5/3. In the formation of hydroxyapatite with the heretofore described calcium phosphate cements, the formation of hydroxyapatite can proceed slowly if the cement is initially formed at a pH above about 8, and if the selection of precursors for such a cement would provide a pH of 8 or above, use of a setting accelerator is preferred. In some embodiments, one may choose the overall Ca/P in order to cause formation of a different calcium phosphate in the resulting cement, such as DCPA or DCPD.
[0055] Furthermore, the particle size of the at least one calcium phosphate can be adjusted to modify the rate of the rapid dissolution of calcium phosphate minerals during cement mixing and injection, as the particle size has effects on the chemistry of the setting reactions by controlling the pH and consequently, the setting reaction rate and strength.
[0056] The particle size of the calcium phosphate minerals (as well as any other powder components added to each paste) was measured using Beckman Coulter's LS 13320 Series particle size analyzer. It is noted that the particle size values mentioned herein refer to Volume Mean Diameter values.
[0057] A sample for analysis was prepared by adding a small amount of powder in a carrier medium. When the powder material is calcium phosphate, ethanol was used. The slurry was mixed aggressively for a short period of time prior to the analysis of the sample.
[0058] Volume distributions of mean diameter values were then obtained. Upon measurement completion, the cell was emptied and cleaned and refilled with the slurry of the powder in a carrier medium and repeated several times.
Calcium Phosphate Minerals
[0059] That at least one source of calcium phosphate useful in accordance with the present invention generally includes numerous calcium phosphate minerals already known in the art, such as those taught by Brown and Chow in U.S. Reissue patents 33,161 and 33,221, Chow and Takagi in U.S. Pat. Nos. 5,522,893, 5,542,973, 5,545,294, 5,525,148, 5,695,729 and 6,325,992 and by Constantz in U.S. Pat. Nos. 4,880,610 and 5,047,031, teachings of which are incorporated herein by reference.
[0060] Any suitable calcium compound may be used in conjunction with this embodiment of the invention. In preferred embodiments, the calcium compound is a calcium phosphate having a Ca/P ratio ranging from about 0.5-2.0. Alternatively, or in addition thereto, the calcium compound may be a suitable calcium salt, or any suitable calcium compound that is sparing soluble in acid.
[0061] Exemplary calcium compounds suitable for use in conjunction with the invention include tetracalcium phosphate (TTCP), dicalcium phosphate anhydrous (DCPA), dicalcium phosphate dihydrate (DCPD), monocalcium phosphate anhydrous (MCPA), monocalcium phosphate monohydrate (MCPM), alpha-tricalcium phosphate (alpha-TCP), beta tricalcium phosphate (beta-TCP), hydroxyapatite (HA), amorphous calcium phosphate (ACP), octacalcium phosphate (OCP), calcium deficient hydroxyapatite (CDH), carbonate-containing hydroxyapatite (CHA), fluoride-containing hydroxyapatite (FHA), calcium lactate, calcium sulfate, calcium gluconate, calcium lactate gluconate, calcium glycerophosphate, calcium silicate, calcium hydroxide, and other biocompatible calcium compounds with a solubility of at least about 2 wt. % in the acid environment. Generally, calcium compounds that are biocompatible and that form a suitable cement may be used. The selection of a particular calcium compound may be based on numerous factors, including for instance the reactivity of the compound with the selected acid, and also the overall acid and base contents of the cement, and the desired end cement products
Acidic Aqueous Paste
[0062] In a preferred embodiment, the acidic aqueous paste composition comprises at least one acidic calcium phosphate mineral, at least one synthetic polymer based paste stabilizing agent, a pH buffering agent, a humectant, and water.
Acidic Calcium Phosphate Mineral
[0063] The acidic calcium phosphate mineral is preferably monocalcium phosphate monohydrate (MCPM), monocalcium phosphate anhydrous (MCPA), dicalcium phosphate dehydrate (DCPD), and dicalcium phosphate anhydrous (DCPA).
[0064] In a preferred embodiment, the mean particle size of the at least one acidic calcium phosphate mineral is between about 0.4 μm to about 200 μm, preferably about 0.7 μm to about 150 μm, and most preferably about 1 μm to about 90 μm.
[0065] In a more preferred embodiment wherein the acidic aqueous paste contains MCPM and DCPA, the mean particle size of MCPM is between about 0.4 μm to about 200 μm, preferably about 10 μm to about 150 μm, and most preferably about 30 μm to about 90 μm; the mean particle size of the DCPA is between about 0.4 μm to about 200 μm, preferably about 0.7 μm to about 50 μm, and most preferably about 1 μm to about 20 μm.
[0066] With respect to an amount of the acidic calcium phosphate mineral present in the acidic aqueous paste, it may be present in an amount of between about 1% w/w and about 80% w/w, and preferably about 5% w/w and about 65% w/w based on the total weight of the acidic aqueous paste.
[0067] In a preferred embodiment wherein the acidic aqueous paste contains MCPM and DCPA, MCPM may be present in an amount of between about 1% w/w and about 40% w/w, more preferably between about 5% w/w and about 20% w/w based on the total weight of the acidic aqueous paste; and DCPA may be present in an amount of between about 20% w/w and about 80% w/w, more preferably between about 40% w/w and about 65% w/w based on the total weight of the acidic aqueous paste.
Synthetic Polymer Based Paste Stabilizing Agent for the Acidic Aqueous Paste
[0068] The synthetic paste stabilizing agent in accordance with the present invention can be any material useful for stabilizing the acidic aqueous paste to prevent or retard an unwanted alteration of the physical state, such as separation of the powder components from the liquid components even after the paste is exposed to gamma radiation for terminal sterilization.
[0069] Applicants have found that post irradiation stability of the acidic aqueous paste is achieved by using synthetic polymer based paste stabilizing agent rather than natural cellulose based polymer. Without wishing to be tied to a theory, it is believed that the natural cellulose polymers are susceptible to degrade into low molecular weight species in acidic aqueous medium during terminal sterilization, thereby affecting the viscosity of the paste during storage.
[0070] The synthetic polymer based paste stabilizing agent in accordance with the present invention allows the acidic aqueous paste to stay storage stable for a long term, even after it is exposed to gamma radiation for sterilization.
[0071] Examples of a paste stabilizing agent which can be used in the acidic aqueous paste, without limitation, are PVP and PEG.
[0072] Although PVP is quite often cross linked in a basic medium during terminal sterilization, in an acidic medium, it is believed that the rate of cross linking is slow, especially in the presence of calcium salts as the pyrrolidone ring is primarily engaged with calcium salts through ionic interactions. Accordingly, the pyrrolidone ring is protected from not being opened and cross-linked. Although an acidic aqueous paste comprising a higher amount of PVP provides greater stability, this results in the reduction of the reactivity to the alkaline non-aqueous paste. Therefore, when PVP is used as a synthetic polymer based paste stabilizing agent for the acidic aqueous paste, it must be present in an optimal level.
[0073] The mean molecular weight (Mw) of the PVP in the acidic aqueous paste is between about 1,000 Mw to about 1,000,000 Mw, preferably between about 10,000 Mw to about 100,000 Mw, more preferably about 20,000 to about 80,000 Mw, even more preferably about between 40,000 Mw to about 70,000 Mw, but most preferably between 50,000 Mw to about 60,000.
[0074] With respect to the amount of the PVP in the acidic aqueous paste, the PVP may be present in an amount of between about 0% w/w and about 40% w/w, more preferably between about 0.05% w/w and about 20% w/w, but most preferably between 1% w/w to 10% w/w based on the total weight of the paste.
[0075] It is also believed that PEG bonds with hydrogen molecule in the acidic aqueous paste, thereby slowing down the mobility of water molecules in the system to produce stability. The molecular weight of the PEG chain is important as rigidity of the chain itself plays important role in stability. Although an acidic aqueous paste comprising a higher amount of PEG provides greater stability; this results in the reduction of the reactivity to the alkaline non-aqueous paste. Therefore, when PEG is used as a synthetic polymer based paste stabilizing agent for the acidic aqueous paste, it must be present in an optimal level.
[0076] The mean molecular weight (Mw) of the PEG in the acidic aqueous paste is between about 1,000 Mw to about 60,000 Mw, preferably between about 5,000 Mw to about 40,000 Mw, more preferably between about 10,000 Mw to about 40,000 Mw, but most preferably between 15,000 Mw to about 25,000 Mw.
[0077] With respect to the amount of the PEG in the acidic aqueous paste, the PEG may be present in an amount of between about 0% w/w and about 40% w/w, more preferably between about 0.05% w/w and about 20% w/w, but most preferably between 1% w/w to 10% w/w based on the total weight of the paste.
pH Buffering Agent
[0078] In the acidic aqueous paste, a pH buffering agent is added to the paste in order to provide lower pH as well as to form ionic interaction with at least one acidic calcium minerals to provide paste stability. Without wishing to be bound to a theory, it is also believed that the pH buffering agent in accordance with the present invention can act as a setting accelerating agent, influencing the setting reaction once the acidic aqueous paste and the alkaline non-aqueous paste systems are combined.
[0079] Examples of a pH buffering agent which can be used in the present invention, without limitation, are citric acid, phosphoric acid, tartaric acid and malic acid and their salts, including trisodium citrate, sodium phosphate monobasic and disodium tartarate. The preferred pH buffering agent is citric acid. The citric acid can come in several forms, which are anhydrous, monohydrate, or dihydrate. The preferred form of citric acid is the monohydrate form.
[0080] The pH buffering agent is present in an amount of between about 1% w/w to about 10% w/w, or more preferably, in an amount of between about 5% w/w to about 8% w/w.
Humectant
[0081] The humectant in accordance with the present invention can be any material to help the water molecules within the acidic aqueous paste intact through formation of hydrogen bonds, thus enhancing the paste stability and injectability of the paste. Although an acidic aqueous paste comprising a higher amount of humectant provides greater injectability, this results in the reduction of the reactivity to the alkaline non-aqueous paste. Therefore, when a humectant is used in the acidic aqueous paste, it must be present in an optimal level.
[0082] Examples of a humectant which can be used in the present invention, without limitation, are glycerol, propylene glycol, glycol triacetate, sorbitol, lactic acid, and urea. The most preferred humectant is glycerol.
[0083] With respect to the amount of the humectant, it may be present in the acidic aqueous paste in an amount of between about 0% w/w and about 4% w/w, more preferably between about 0.5% w/w and about 2% w/w based on the total weight of the acidic aqueous paste.
Water
[0084] The amount of water present in the acidic aqueous paste may be between about 10 w/w % and about 30 w/w %, more preferably between about 15 w/w % and about 25 w/w %, based on the total weight of the aqueous paste.
Alkaline Non-Aqueous Paste
[0085] In a preferred embodiment, the alkaline non-aqueous paste composition comprises at least one basic calcium phosphate mineral, at least one paste stabilizing agent, a surfactant, and solvent.
Basic Calcium Phosphate Mineral
[0086] The basic calcium phosphate mineral is, preferably, β-tricalcium phosphate, α-tricalcium phosphate, tetracalcium phosphate, oxyapatite, hydroxyapatite or calcium-deficient hydroxyapatite. The most preferred at least one basic calcium phosphate mineral is tetracalcium phosphate (TTCP).
[0087] In another preferred embodiment, the mean particle size of at least one basic calcium phosphate mineral is between about 0.4 μm to about 200 μm, preferably between 2 μm to about 90 μm, and more preferably 30 μm to about 70 μm, and most preferably 45 μm to about 55 μm.
[0088] In another embodiment wherein the alkaline non-aqueous paste contains bimodal distribution of TTCP, the mean particle size of the first set of TTCP is preferably between 2 μm to about 60 μm, more preferably between 10 μm to 30 μm, and the mean particle size of the second set of TTCP is between 10 μm to 90 μm, more preferably between 25 μm to 60 μm.
[0089] With respect to an amount of the basic calcium phosphate mineral present in the alkaline non-aqueous paste, it may be present in an amount of between about 1% w/w and about 90% w/w, and preferably about 10% w/w and about 80% w/w based on the total weight of the alkaline non-aqueous paste.
[0090] In the most preferred embodiment wherein the alkaline non-aqueous paste contains TTCP, the TTCP may be present in an amount of between about 40% w/w and about 90% w/w, more preferably between about 60% w/w and about 80% w/w based on the total weight of the alkaline non-aqueous paste.
Paste Stabilizing Agent for the Alkaline Non-Aqueous Paste
[0091] The paste stabilizing agent in accordance with the present invention can be any material useful for stabilizing the alkaline non-aqueous paste to prevent or retard an unwanted alteration of the physical state, such as separation of the powder components from the liquid components even after the paste is exposed to gamma radiation for terminal sterilization.
[0092] With respect to the alkaline non-aqueous paste, Applicants have surprisingly found that the use of either the natural or synthetic polymers does not affect the non-aqueous paste's long term storage stability even after it is exposed to the terminal sterilization process, such as gamma irradiation.
[0093] Without wishing to be bound by a theory, it is believed that when a paste stabilizing agent, such as PEG and/or cellulose polymers are dissolved in non-aqueous solvents such as glycerol or propylene glycol, a complex hydrogen bond network is formed in which the TTCP particles are suspended, thereby making the paste storage stable for a long term.
[0094] Examples of a paste stabilizing agent which can be used in the alkaline non-aqueous paste, without limitation, synthetic polymer such as PEG or a natural cellulose-based polymer, such as hydroxyethylcellulose (HEC), ethylcellulose, methylcellulose, hydroxypropyl cellulose, carboxymethyl cellulose, hydroxypropyl methyl cellulose. The most preferred paste stabilizing agent for the alkaline non-aqueous paste is PEG and HEC when preferentially using an antioxidant such as thioglycerol.
[0095] The mean molecular weight (Mw) of the PEG in the alkaline non-aqueous paste is between about 1,000 Mw to about 60,000 Mw, preferably between about 5,000 Mw to about 40,000 Mw, more preferably between about 10,000 Mw to about 40,000 Mw, but most preferably between 15,000 Mw to about 25,000 Mw.
[0096] With respect to the amount of the PEG in the alkaline non-aqueous paste, the PEG may be present in an amount of between about 0% w/w and about 20% w/w, more preferably between about 0.5% w/w and about 10% w/w, but most preferably between 1% w/w to 5% w/w based on the total weight of the paste.
[0097] The mean molecular weight (Mw) of the HEC in the alkaline non-aqueous paste is between about 90,000 Mw to about 1,500,000 Mw, preferably between about 1,000,000 Mw to about 1,400,000 Mw.
[0098] With respect to the amount of the HEC present in the alkaline non-aqueous paste, the HEC may be present in an amount of between about 0% w/w and about 5% w/w, more preferably between about 0% w/w and about 1% w/w, but most preferably 0% w/w to 0.5% w/w based on the total weight of the paste.
Surfactant
[0099] The surfactant in accordance with the present invention can be any material useful for preventing coagulation of colloidal particles by helping particles suspend in liquid and to reduce the surface tension of the basic calcium phosphate mineral in the alkaline non-aqueous paste.
[0100] The surfactant of the present invention may be supplied in only the one of the at least two pastes, or in some or all of the at least two pastes. However, in a preferred embodiment where there are two pastes in a system containing acidic aqueous paste and alkaline non-aqueous paste, the surfactant is in the alkaline non-aqueous paste only.
[0101] Examples of a surfactant which can be used in the present invention, without limitation, are glycerol monostearate, lecithin, phospholipids, glycerol distearate, polyethylene glycol distearate, block polymers of PEG-PPG-PEG or PPG-PEG-PPG, Tween, Span, any polysorbate fatty acid ester or polysorbate monooleate (from oleic acid) or sorbitol esters. The most preferred surfactant is polysorbate 80.
[0102] With respect to the amount of the surfactant, it may be present in an amount of between about 0% w/w and about 4% w/w, more preferably between about 0.5% w/w and about 2% w/w based on the total weight of the total formulation when at least two pastes are combined.
[0103] In a preferred embodiment of the present invention, the surfactant may be present in an amount of between about 0% w/w and about 4% w/w, more preferably between about 0.5% w/w and about 2% w/w based on the total weight of the acidic aqueous paste containing MCPM and DCPA; and the reaction retarding agent may be present in an amount of between about 0% w/w and about 4% w/w, more preferably between about 0.5% w/w and about 2% w/w based on the total weight of the alkaline non-aqueous paste containing TTCP.
Solvent in Alkaline Non-Aqueous Paste
[0104] The solvent for the alkaline non-aqueous paste can be any suitable non-aqueous liquid at room temperature, which excludes water. Examples of the solvent for the alkaline non-aqueous paste in accordance with the present invention, without limitation, are glycerol, ethanol, propanol, and propylene glycol. The preferred solvent is glycerin and propylene glycol due to their biocompatibility and complete miscibility with water.
[0105] The non-aqueous liquid solvent in the alkaline non-aqueous paste may be present in an amount of between about 10 w/w % and about 40 w/w %, more preferably between about 20 w/w % and about 30 w/w %, and most preferably between about 22 w/w % and about 28 w/w %, based on the total weight of the alkaline non-aqueous paste.
Additive(s)
[0106] Various additives may be included in the inventive cements, slurries and pastes to adjust their properties and the properties of the hydroxyapatite products made from them. For example, proteins, osteoinductive and/or osteoconductive materials, X-ray opacifying agents, medicaments, supporting or strengthening filler materials, crystal growth adjusters, viscosity modifiers, pore forming agents, and other additives and a mixture thereof may be incorporated without departing from the scope of this invention.
[0107] The nature of the compounds and functional materials present in the cements is not limited to the heretofore described ingredients, but to the contrary any other suitable osteoconductive, bioactive, bioinert, or other functional materials may be used in conjunction with the invention. When used, these optional ingredients may be present in any amounts suitable for their intended purposes. For instance, particularly in the case of the calcium phosphate cements, one or both cement precursor phases may include a setting accelerator, such as phosphoric acid, hydrochloric acid, sulfuric acid, oxalic acid, and salts thereof, and sodium phosphate, potassium phosphate, and sodium fluoride. In some embodiments, some of the calcium phosphate materials themselves may promote setting; for instance, MCPM and certain nano-sized calcium phosphate materials may promote setting of the cement. Any other suitable setting accelerator may be used in conjunction with the present invention. Setting accelerators are described in more detail in Chow et al., U.S. Patent Application Publication No. 2005/0074415, published Apr. 7, 2005.
[0108] In some embodiments, one of the cement precursors includes an osteoinductive protein, by which is contemplated any protein that is useful in assisting in or inducing bone formation. Osteoinductive proteins are deemed particularly suitable for use in conjunction with the carboxyl/calcium cement systems because, at least for many known osteoinductive proteins, such proteins may denature at an alkaline pH.
[0109] Another optional ingredient is a filler, such as a radioopaque filler. The radio opaque filler may, for instance, be a suitable bismuth, barium, or iodide compound, such as barium sulfate or bismuth hydroxide. Other suitable fillers include bioglass, silica based, alumina based, biphasic calcium phosphate, calcium silicate, calcium sulfate, granular calcium phosphate ceramics, and the like.
[0110] A medicament, such as zinc, magnesium, strontium, boron, copper, silica or any other suitable medicament may be included in one or both of the phases of the cement precursors.
[0111] Either or both of the phases may include a material that is intended to affect the viscosity, cohesiveness, or injectability of the phases. Any suitable biocompatible ingredient.
[0112] In some embodiments, a macropore forming material may be used. As disclosed, for instance, in prior U.S. Pat. Nos. 7,018,460 and 6,955,716, a macropore forming material, such as mannitol, is useful in forming a macropores, or pores having a size greater than 150 microns. Such pores are sometimes deemed desirable and that they create a structure that may be useful in promoting growth of soft tissue in or near the region of these cements.
[0113] Also as described in U.S. Pat. Nos. 7,018,460 and 6,955,716, in some embodiments, one or more strength-enhancing components, such as fibers, meshes, or the like, may be used. Such components may be resorbable or non-resorbable.
EXAMPLES
[0114] Several formulations in accordance with the present invention were made as illustrated below in Examples 1, 2 and 3. A table of abbreviations used in Examples 1, 2 and 3 is provided below.
[0000]
Abbreviations
PEG = Polyethylene Glycol
MCPM = Monocalcium Phosphate Monohydrate
DCPA = Dicalcium phosphate Anhydrous
TTCP = Tetracalcium Phosphate
CAM = Citric Acid Monohydrate
SPM = Sodium Phosphate Monobasic
Span 80 = Sorbitan Monooleate
Tween 80 = Polysorbate 80
HEC = Hydroxyethylcellulose
TSCD = Trisodium Citrate Dihydrate
Example 1
[0115]
[0000]
Mean Particle Size (μm)/ Mean
Paste Type
Material
% w/w
Molecular Weight (Mw)
Acidic Aqueous
MCPM
11.60
40-60 μm
Paste
DCPA
58.04
1-12 μm
Water (WFI)
18.59
Citric Acid
7.45
Monohydrate
PEG
1.21
20k Mw
Glycerol
1.33
PVP
1.78
58k Mw
TOTAL
100.00
Alkaline Non-
TTCP
57.63
10-30 μm
aqueous Paste
TTCP
14.12
30-80 μm
Propylene Glycol
24.86
Tween 80
1.13
PEG
2.26
20k Mw
TOTAL
100.00
Example 2
Examples of Various Acidic Aqueous Pastes
[0116]
[0000]
Formulation
Paste
Mean Particle size
Family
Weights
(μm)/Mean Molecular
Reference
Material
(grams)
weight (Mw)
A
MCPM
10.28
40-60 μm
DCPA
51.42
1-12 μm
Water
17.38
TSCD
0.95
150-220 μm
CAM
6.96
Glycerol
0.36
PEG
0.93
20K Mw
B
MCPM
10.00
40-60 μm
DCPA
50.00
1-12 μm
Glycerol
0.36
SPM
0.5
Water
15.02
CAM
6.01
PEG
1.43
20 kMw
PVP
3.47
58k Mw
C
MCPM
10.00
40-60 μm
DCPA
50.00
1-12 μm
Glycerol
1.2
SPM
25.0
Water
16.01
CAM
6.41
PEG
1.66
20k Mw
PVP
2.25
58k Mw
D
MCPM
10.0
40-60 μm
DCPA
50.0
1-12 μm
Water
19.45
CAM
7.87
HEC
0.28
1.3 × 10{circumflex over ( )}6 Mw
E
MCPM
11.60
40-60 μm
DCPA
58.04
1-12 μm
Water (WFI)
18.59
CAM
7.45
PEG
1.21
20k Mw
Glycerol
1.33
PVP
1.78
58k Mw
F
MCPM
10.0
40-60 μm
DCPA HS II
54.98
1-12 μm
SPM
0.5
Water
40.0
CAM
14
G
MCPM
10.0
40-60 μm
DCPA HS II
50.0
1-12 μm
Phosphoric Acid
0.5
85%
Water
100.0
CAM
40.04
PVP C30
14.0
Example 3
Examples of Various Alkaline Non-Aqueous Pastes
[0117]
[0000]
Formulation
Paste
Mean Particle size/
Family
Weights
Mean Molecular weight
Reference
Material
(grams)
(Mw)
A1
TTCP
48.0
10-30 μm
TTCP
12.0
30-80 μm
Propylene Glycol
20.93
Span 80
0.92
PEG
1.84
20k Mw
B1
TTCP
48.0
10-30 μm
TTCP
12.0
30-80 μm
Propylene Glycol
20.93
Tween 80
0.92
PEG
1.84
20k Mw
Cl
TTCP
60.0
10-30 μm
Propylene Glycol
22.67
HEC
0.33
1.3 × 10{circumflex over ( )}6 Mw
D1
TTCP
57.63
10-30 μm
TTCP
14.12
30-80 μm
Propylene Glycol
24.86
Tween 80
1.13
PEG
2.26
20k Mw
E1
TTCP
48.0
10-30 μm
TTCP
12.0
30-80 μm
Glycerol
9.0
PEG
10.0
20k Mw
Triacetin
90.0
[0118] The dual pastes containing precursor for bone cement of the present invention were subjected to an array of qualification tests to verify that they meet the performance requirements. The dual pastes system of the present invention was analyzed for long term stability.
[0119] Long term stability may be measured by any technique or using any criteria deemed appropriate. In accordance with one such technique, a sample of the material or materials constituting the paste is first gamma irradiated and put in a accelerated aging chamber which is heated to a temperature of 40° C. at a relative humidity of 75%, and held at this temperature for a set period of time. The acidic aqueous paste and the alkaline non-aqueous paste then are mixed to form a cement, and the setting time of the cement is evaluated as compared with the original setting time of a similar cement made without thermal treatment of either of the pastes. If the setting time of the cement made with the thermally treated phase is approximately equal to the setting time of the similar cement, the paste may be deemed suitably stable for use in conjunction with the present invention. The invention is not limited to cement precursor systems that meet this criterion; rather, the foregoing is provided to illustrate one of but many possible methods for evaluating stability.
[0120] In the present case, the pastes illustrated in Examples 1, 2 and 3 were first sterilized using gamma radiation and put in an accelerated aging test chamber.
[0121] Subsequently, the acidic aqueous paste and the alkaline non-aqueous paste were mixed to form a bone cement and the resulting bone cement was tested for (1) aging stability, (2) wet field penetration resistance, (3) compression strength and (4) injectability, which are described in more details below.
Gamma Irradiation
[0122] Irradiation dose ranging between 25-35 kGy was used to sterilize the pastes of Examples 1, 2 and 3 following the protocol of ISO 11137-2, disclosure of which is incorporated by reference herein. The irradiation dose mentioned above is merely a preferred range, and that the irradiation dose should not be limited to the range mentioned above, but should be selected such that it is sufficient to sterilize while the adverse effects such as degradation, loss of stability, loss of efficacy of the pastes, etc. are minimal.
[0123] After the exposure to gamma irradiation for sterilization, the pastes were tested both pre-aged and post-aged after being put in the accelerated aging test conditions for a predetermined period of time as explained below.
Aging Test
[0124] The aqueous and alkaline non-aqueous pastes as described in Examples 1, 2 and 3 above were analyzed for long-term stability.
[0125] The various pastes were packaged in an air and moisture impermeable double barreled syringe system and were placed in a climatic oven set at an ambient temperature of 21° C. and aged for a set period of time.
[0126] After the exposure in the aging test conditions for a predetermined period of time, the pastes were analyzed to assess the dual pastes' stability and cement performance. A successful outcome in terms of paste stability was considered achieved when the aged paste test results were directly comparable with the non-aged, i.e. control samples, which were tested at a timepoint of zero. Such a result indicated no detectable degradation of the paste system over time under the test conditions used. The results are presented in Table A below.
Dispersion Analysis; Lumisizer Testing
[0127] The cements were produced as described in Examples 1, 2 and 3, were exposed to gamma radiation for sterilization and were tested for stability via dispersion analysis by use of LUMiSizer analysis. Approximately 0.5 ml of the paste to be tested was filled into a clean LUMiSizer vial to the predefined line on the vial. The vial was then sealed with the supplied screw cap lid and this sealed vial was then placed into the LUMiSizer and secured. The dispersion analysis test can now be performed and run to completion. The output from this test method displays the dispersion of the paste system in relation to time over a specific gravity applied onto the paste via centrifugal force. This dispersion data can be used to indirectly correlate the stability of the paste system and used for comparative purposes between various paste systems. A successful outcome in terms of paste stability was considered to be achieved when the aged paste dispersion test results were directly comparable with the non-aged, i.e. control samples, which were tested at a timepoint of zero. Such a result indicated no detectable degradation of the paste system over time under the test conditions used. FIG. 1 is an overview to dispersion analysis results generated for various formulations that were tested at various time points (0, 1, 3, 7, 14, 15, 21 and/or 28 days respectively).
Wet Field Penetration Resistance Test
[0128] The cements produced as described in Examples 1, 2 and 3, which were exposed to gamma radiation for sterilization and the accelerated aging conditions, were tested for wet field penetration resistance. The test consists of applying a load applicator through the cement at specific time points. The load applicator was made up of a small cylindrical stainless steel needle with 1/16″ in diameter. Immediately after initial mixing of the acidic aqueous paste and alkaline non-aqueous paste, the cement composition was deposited into a long groove (¼″ wide×¼″ deep) of a block heated at 32° C. One minute after the initial mixing, the cement was subjected to a constant flow of saturated phosphate solution using a Watson Marlow 323 peristaltic pump set at 20 rpm. The solution was kept constant at 32° C. Ten minutes after the initial mixing, the load applicator was made to penetrate the cement for 1.27 mm and the result force was recorded. Table A below shows the results of the penetration resistance tests using the bone cements produced according to Examples 1, 2 and 3. FIG. 2 is a graphical overview of the analysis results of wet field tests of the formulation of the present invention comprising the acidic aqueous paste E of Example 2 and the alkaline non-aqueous paste D1 of Example 3 before and after the aging test. This wet field penetration resistance test result can be considered having a successful outcome in terms of demonstrating paste stability as can be seen from this figure that the aged paste penetration test results were directly comparable with the non-aged, i.e. control samples, which were tested at a timepoint of zero with no statistically significant difference shown (p>0.05). Such a result indicates no detectable degradation of the paste system over time under the test conditions used.
[0000]
TABLE A
Formulations
Test Method
Compression
@
Acidic
Alkaline Non-
Wet Field
Injectability
4 hr post
Aqueous
Aqueous
(MPa)
(N)
mixing (MPa)
D PRE-AGED
C1 PRE-AGED
28.1
25.0
7.2
D Aged
C1 Aged
39.0
50.0
7.08
A PRE-AGED
C1 PRE-AGED
31.74
86.5
6.03
A Aged
C1 Aged
28.65
77.7
6.65
B PRE-AGED
C1 PRE-AGED
24.85
99.0
4.0
B Aged
C1 Aged
22.78
111.0
4.03
C PRE-AGED
A1 PRE-AGED
27.12
60.5
5.54
C Aged
A1 Aged
19.43
65.5
5.51
C PRE-AGED
B1 PRE-AGED
23.59
66.9
5.74
C Aged
B1 Aged
17.01
65.9
5.79
E PRE-AGED
D1 PRE-AGED
25.36
88.72
E Aged
D1 Aged
23.85
82.03
Injectablity Test
[0129] The cements produced as described in Examples 1, 2 and 3, which were exposed to gamma radiation for sterilization and the accelerated aging conditions, were also tested for injectability. A dual barrel syringe containing the combination of paste systems as described in Table above are placed in a test rig in a Tinius Olsen Tensometer electro-mechanical testing machine. The start of the test is T=0. Once the plunger reaches the set preload (5N), it displaces at a rate of 25 mm/min until the required extension is reached (15 mm). Once the 20 seconds wait has elapsed, the test resumes until a total displacement of 30 mm is reached unless a maximum load of 300N is reached first. This ‘stop-start’ function is required to provide the user with a flexibility in usage of the dual paste system with an injectability window.
[0130] For this test, maximum initial injectability force shall not exceed 225N, more preferably 150N for both the initial injectability as well as re-starting after stopping injection for 20 sec. The results are recorded in the Table A above. FIG. 3 is a graphical overview of the analysis results of wet injectability tests of the formulation of the present invention comprising the acidic aqueous paste E of Example 2 and the alkaline non-aqueous paste D1 of Example 3 before and after the aging test. This test result can be considered having a successful outcome in terms of demonstrating paste stability as can be seen from this figure that the aged paste injectability test results were directly comparable with the non-aged, i.e. control samples, which were tested at a timepoint of zero. Such a result indicates no detectable degradation of the paste system over time under the test conditions used. The injection force to enable the evaluation of ease of injectability can be obtained from ANSI/AAMI HE75:2009 (p. 367, FIG. 22.13) whereby 95% of males and 50% of females can squeeze up to 107N over a grip span range from 4.5 cm to 11 cm.
Compression Test
[0131] The cements produced as described in Examples 1, 2 and 3 were also tested for compressive strength. A set amount of the dual paste system (as listed in Table A) is injected into a cylindrical mould to form a set cement shape of diameter 6 mm and 12 mm length. The mould is then placed in Phosphate Buffered Saline (PBS) solution and the cement is allowed to set in this mould. Remove the set cement at a 4 hrs time point after incubation in PBS.
[0132] Measure the diameter and length of each specimen before separately placing each sample to be tested on the Tinius Olsen Tensometer electro-mechanical testing machine, ensuring that the load rate is set at 1 mm/min. Record the maximum load at which the cylindrical sample fails under compressive loading. The results are recorded in the Table A above.
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The present invention relates to a bone cement precursor system that is presented in the form of two shelf-stable pastes which have been terminally sterilized and are held in separate containers during product transport and storage. When the product is used during surgery, these pastes inject to a site of application through a static mixing device by the action of applied injection force. When the two pastes are mixed, they start to react to each other while injecting out. The resulting composition is highly biocompatible, osteoconductive, injectable, rapid setting and bioresorbable, and is useful in connection with bone repair procedures, for example, in the craniomaxillofacial, trauma and orthopedic areas.
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BACKGROUND OF THE INVENTION
This invention relates to an automatic thread handling system and, more particularly, to a system for controlling the needle thread for formation of each stitch.
In prior-art sewing machines, needle thread control was effected by tensioning the needle thread by a pair of discs mounted in the thread path between the thread supply and the eye of the needle. Such systems necessitate manual operation of a tension setting dial before sewing, so that a tension suitable for the impending sewing operation is applied by the discs to the needle thread. Thus, a complicated operation is required in preparation for sewing, and several trial sewing operations must usually be carried out to achieve neat stitches.
In order to overcome this problem, a variety of automatic thread handling systems have been devised, one example of which is disclosed in U.S. Pat. No. 4,215,641. The automatic needle thread control in these prior art systems is common in the following respects. That is, a thread-extracting mechanism is provided for extracting the needle thread from the thread supply and replenishing the thread used in the stitch formation. A computer calculates the length of thread to be extracted, based on work thickness and stitch length, and the resulting value is used to control the operation of the thread-extracting mechanism The thread thus extracted is taken up by a thread take-up mechanism including a take-up lever having a well-known characteristic illustrated by the solid-line curve in FIG. 4. The take-up mechanism is mechanically or electrically synchronized with the main shaft of the sewing machine for synchronizing the operation of the take-up lever with the vertical motion of the needle. The prior-art automatic thread handling systems are highly effective in reducing the work load of the operators in making preparations for sewing; however, the overall mechanical and electrical structures are rather complicated because of the necessity of incorporating the thread-extracting mechanism, in addition to the thread take-up mechanism, into the narrow space available within the head of the sewing machine.
SUMMARY OF THE INVENTION
It is, therefore, an object of the present invention to provide an automatic thread handling system having an improved thread-regulating mechanism for setting the length of needle thread needed to form each stitch and for taking up the thread from the needle.
For realizing this object, the automatic thread handling system of the present invention has a regulating mechanism mounted along a thread path leading from the thread supply to the needle, and a central processing unit for controlling the drive of the regulating mechanism based on work thickness and stitch length, the length of needle thread supplied for each stitch being set by the controlled drive of the regulating mechanism.
As is well known, the length of the needle thread used for the loop formed and expanded by the rotation of the looptaker is that necessary for forming a loop of fixed size as determined by the mechanical design of the machine. The needle thread is extracted from the thread supply mainly under the action of the looptaker rotation and is fed toward the needle. The needle thread length required for formation of each stitch is determined by stitch length and thickness of the workpiece being sewed.
The regulating mechanism of the present invention may be a reversible device which supplies the required length of needle thread prior to loop contraction and takes up the desired length of thread during such contraction. The mechanism may also be so designed that only the amount of thread to be taken up during contraction is controlled, thereby simplifying the control function of the central processing unit. For example, the desired length of needle thread may be extracted with rotation of the loop-taker to form a thread loop of fixed size, and the optimum thread take-up length determined according to work thickness and stitch length. The optimum take-up length is the length needed to form the fixed loop minus the length required to form each stitch. Thus, according to the present invention, the thread take-up mechanism and the mechanism for setting the length of needle thread necessary for stitch formation are integrally formed for automatic thread handling, in contrast to the customary procedure in which these two operations were separated from each other.
Thus, the system of the present invention enables the mechanical structure of the automatic thread handling system to be simplified considerably. As a result, the system can be easily built into the limited space available in the sewing machine head, while at the same time increasing the operational speed and reliability of the machine. Other features of the invention will become apparent from the following description of preferred embodiments thereof.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of a sewing machine incorporating an automatic thread handling system embodying the present invention.
FIG. 2 is a perspective view of a portion of the internal mechanism of a first embodiment of the invention.
FIG. 3 is a block diagram of the electrical control system for controlling the sewing machine of FIGS. 1 and 2.
FIG. 4 is a diagram showing certain operational characteristics of the sewing machine in a stitch forming cycle, and a timing diagram illustrating the thread take-up operation.
FIGS. 5a, 5b and 5c are flow charts illustrating the operation of the sewing machine of FIGS. 1 and 2 with the control system of FIG. 3.
FIG. 6 is a perspective view of a portion of the internal mechanism of a second embodiment of the invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
An embodiment of a sewing machine in which the automatic thread handling system is incorporated is hereinafter described by referring to the accompanying drawings.
In FIG. 1, a sewing machine 1 comprises a base 2, a standard 3 and a head portion 4. To the left rear side of the base 2 a lower arm having a work supporting surface 5a is projected horizontally and to the left front side thereof is detachably mounted an auxiliary plate 6. The plate 6 is in the form of a letter L consisting of an elongated auxiliary plate portion 6a extending towards the left-hand side and an auxiliary plate portion 6b extending towards the rear. A throat plate 7 is mounted to the left-hand side on the upper surface of the lower arm 5. Towards the front side on the upper surface of the base 2 are mounted a self lock-type power switch 8 and self lock-type speed setting switches 9, 10, 11 designed for low-, medium- and high-speed operation, respectively.
On the front surface of the head portion 4 is a pattern panel 15 with a number of symbol marks 12 for various stitch patterns, light emitting diodes (LEDs) 13, self restoring type pattern selection switches 14, and a self restoring type start stop switch 16. Upon actuation of a selected one of the switches 14, the symbol mark corresponding to the selected pattern is indicated by illumination of the corresponding LED 13 located between the switch 14 and the mark 12. The start stop switch 16 is so designed that, upon actuation thereof, a drive motor mounted in the head portion is energized and, upon a further actuation thereof, the drive motor is de-energized.
Upon actuation of the drive motor, a needle 17 performs simultaneously a vertical reciprocating motion and a jogging motion with a predetermined bight as determined by a lateral jogging mechanism (not shown) mounted within the head portion 4. A feed dog (not shown) also performs a fabric feed motion by a work feeding mechanism (also not shown) mounted within said lower arm 5. A looptaker (not shown) mounted in the lower arm 5 is also driven for expanding a thread loop. A presser foot 18 is carried by a presser bar 19, as shown in FIG. 2, and is designed to press the workpiece with a predetermined pressure by a pressure setting mechanism (not shown) and to be vertically movable by a presser lift lever (not shown). A rack 20 is secured to the upper part of the presser bar 19 and meshes with a gear 22 operatively connected to a movable terminal of a potentiometer 21. The gear 22 is driven by vertical movement of the presser bar 19, and the potentiometer 21 provides an analog output corresponding to the angle of rotation of the gear 22 so that the thickness of the workpiece may be determined on the basis of the analog output.
A needle position sensor 23 (FIG. 3) is mounted on the main shaft of the sewing machine to detect the position of the needle 17 or, more particularly, as shown in FIG. 4, to provide a needle position indicating signal SG 1 which rises and falls when the needle 17 is raised above the throat plate 7 or lowered therebelow, respectively. A read-out timing pulse generator 24 (FIG. 3) provides a timing pulse SG 2 which rises shortly after the needle 17 is lowered below the plate 7 from above and falls shortly after the needle 17 is raised above the plate 7 from below, as shown in FIG. 4, and a work thickness sensing timing pulse generator 25 (FIG. 3) provides a work thickness timing pulse SG 3 shortly after the rising of pulse SG 2, as also shown in FIG. 4.
The automatic thread regulating device of the sewing machine 1 will be described with reference to FIG. 2.
In FIG. 2, a needle thread 26, reeled out from a bobbin mounted in the head portion 4 of the sewing machine 1, is passed through an eye of the needle 17 by way of a suction device 27 and the surface of drive roller 28. The roller 28 is connected by gears 29, 30 to an upper shaft 31 operatively connected to the main shaft and is continuously rotated in a direction to raise the needle thread 26. A solenoid 32 is mounted above the roller 28, and a driven roller 33, mounted on the solenoid armature 32a, is biased against the periphery of the roller 28 by a spring 34 for clamping the needle thread 26 so that it may be taken up toward said suction device 27. The thread 26 to be taken up is sucked by said suction device 27 and the thread thus taken up is held under suction within the suction device 27. The device 27 is connected to a suction pump by an electromagnetic valve (not shown) which is opened for initiating the suction operation upon de-energization of the solenoid 32 and closed for terminating the suction operation upon energization of the solenoid 32.
When the solenoid 32 is energized and the roller 33 is raised against the force of spring 34, the needle thread 26 is relased from the clamping pressure exerted by rollers 28, 33 and may be easily taken out during expansion of the upper thread loop by the looptaker.
A rotary disc 35 is secured to the upper shaft 31 and a through-slit 36 is formed in this disc 35. For sensing the passing of the slit 36 of the disc 35 in the course of rotation thereof, a thread take-up start pulse generator 37 consisting of a light emitting section 37a formed by an LED and a sensor section 37b formed by a phototransistor encircles the disc 35. The generator 37 is so designed and constructed that, when the expanding process for the thread loop has come to a termination, the generator provides a thread take-up start pulse signal SG 4, as shown in FIG. 4.
A rotary disc 39 is secured to a drive shaft 38 of the drive roller 28, and a multiplicity of through-slits 40 are formed concentrically and at equidistant intervals in the disc 39. For sensing the passing of the slits 40 of the disc 39 in the course of rotation thereof, a thread take-up timing pulse generator 41, consisting of a light emitting section 41a formed by an LED and a sensor section 41b formed by a phototransistor, encircles the disc 39. In the present embodiment, a distance θ between adjacent slits 40 in the disc 39 is so selected that, for each rotational movement of 5 mm by the roller 28 (wherein rθ=5 mm, r stands for radius of the drive roller 28 and θ is indicated in radians), one thread take-up timing pulse SG 5 is generated by the generator 41.
A drive control circuit, enclosed in the sewing machine, will now be described by referring to the block diagram of FIG. 3.
In FIG. 3, a micro-computer 42 is composed of a central processing unit (CPU), a read only member (ROM) and a random access memory (RAM). The CPU provides a control signal to a motor drive circuit 43, in accordance with a control program stored in ROM, and in response to both the ON signal of switch 16 and the speed setting signals from switches 9, 10, 11, for controlling the drive motor 44 at the selected rotational speed. The CPU also acts, in sequential response to rising and falling of the signal SG 2 from the pulse generator 24, for sequential read-out from ROM of data representing the bight and feed for each stitch pattern selected by a switch 14 and for providing such data to a bight drive circuit 45 and a feed drive circuit 46.
A bight actuator 47 for the lateral jogging mechanism and a feed actuator 48 for the work feeding mechanism determine, for each stitch, the jogging position of the needle 17 and the position of a regulator for setting the feed amount and the feed direction of the feed dog. The CPU also provides a pattern indication signal to an LED 13 of a pattern indicating device 49, in accordance with the pattern selection signal provided by the selected switch 14, for lighting the LED 13 situated above the selected mark 12.
A work thickness sensor 50 provides the CPU with a digital signal converted from the analog signal from the potentiometer 21. Each time the timing pulse SG 3 from generator 25 is supplied to the CPU, the digital signal from the sensor 50 is stored as work thickness in RAM. The thread length required for each stitch formation is calculated by the CPU on the basis of the digital data stored in RAM as work thickness and the stitch data representing the length or distance between successive stitches and the parameters representing the characteristics of pattern to be formed. Further, the CPU calculates the optimum amount of thread to be taken up for each stitch formation by subtracting the required thread length from the length of the thread loop. The generator 37 provides the thread take-up start pulse signal SG 4 to the CPU which then provides an instruction to a solenoid drive circuit 51, based upon said pulse signal, for de-energizing the solenoid 32 and starting the thread take-up operation. The CPU also counts the number of signal pulses SG 5 from said generator 41 for determining the length of needle thread actually taken up by the drive roller 28 for comparison with the optimum amount calculated by the CPU. The CPU operates to energize the solenoid 32, when the drive roller 28 has taken up the optimum length of needle thread 26 by providing a thread take-up stop signal to the drive circuit 51.
The operation of the automatic thread adjustment device in the sewing machine described above will be elucidated by referring to the flow charts shown in FIGS. 5a, 5b and 5c and illustrating the operation of the micro-computer 42.
It is assumed that a desired one of switches 9, 10, 11 is actuated for selecting the operational speed of the sewing machine, the power switch 8 is turned on, the CPU state is initialized, the information in ROM for the formation of a straight stitch is rendered effective, and the LED 13 corresponding to the symbol mark 12 of the straight stitch is illuminated. The CPU also provides a command signal to the drive circuit 51 for energizing the solenoid 32, thereby disengaging the driven roller 33 from the drive roller 28. The needle thread 26 is thus released from clamping by the rollers 28, 33 and can be taken out.
Next, the state of the selection switches 14 is checked by an instruction 60 and, if the switch state is changed by selection of new pattern, the CPU invalidates the straight stitch information and validates the information in ROM for the formation of the selected stitch pattern. The CPU also provides a control signal to the pattern indicating device 49 for illuminating the LED 13 corresponding to the mark 12 for the stitch pattern. If a pattern has not been selected, the information for the straight stitch is still validated in the CPU.
The state of start stop switch 16 is then checked, according to an instruction 61. If this switch is turned on, the CPU sends out a drive control signal to the motor drive circuit 43 for driving the motor 44 at the speed selected by the switches 9, 10, 11. The motor 44 is driven in this way and the needle 17 starts to move downwardly from its uppermost position.
When the needle 17 has been determined, in accordance with an instruction 62, to be in its upper position above throat plate 7, the CPU reads out bight data for the first stitch in the selected stitch pattern from ROM and provides the bight data to the bight drive circuit 45, as a position control signal. The circuit 45 then controls the driving of the bight actuator 47 based upon said control signal. When the needle 17 has been determined, in accordance with instruction 62, to be in its lower position, (as when sewing has been started from the lower stop position for the needle), the fall of the timing pulse signal SG 2 from generator 24 is sensed in accordance with an instruction 63, the bight data is read out in the above manner and driving of the bight actuator 47 is controlled accordingly.
The rise of the timing pulse signal SG 2 from generator 24 is checked in accordance with an instruction 64. If such rise has been sensed, the CPU reads out the feed data for the feed dog from ROM and provides same to the feed drive circuit 46 as a position control signal. The circuit 46 then operates to control the driving of the feed actuator 48 in accordance with said control signal. The CPU reads out bight data for the next stitch from ROM and stores same in a predetermined storage location in RAM. On the other hand, in response to the timing pulse signal SG 3 from generator 25, which is supplied shortly after the rise of the timing pulse signal SG 2 from generator 24, the CPU operates to determine the optimum take-up length of needle thread 26 for contracting the thread loop expanded by the looptaker, to be later described. As described above, the optimum length is based on the digital data from generator 50 representing work thickness and the stitch data representing the distance between successive stitches in the selected stitch pattern. The optimum take-up length is transiently stored in a predetermined storage location in RAM.
As the needle 17 reaches the lowermost position and moves upwardly therefrom, the needle thread 26 is seized at the beak of the looptaker which then starts the loop expanding operation. The thread 26 is thus further lowered (at this time, the needle thread 26 can be withdrawn as the solenoid 32 remains energized). As the needle 17 is raised above the throat plate 7, the workpiece is fed by the feed dog in accordance with the feed data.
The fall of the pulse signal SG 2 from generator 24 is checked in accordance with an instruction 65 and, if such fall is sensed (as when the needle 17 has slightly cleared the plate 7), the bight data stored in RAM is read out and supplied to said drive circuit 45 as a position control signal. The circuit 45 operates to control the driving of the bight actuator 47. Thus, the needle 17 performs a lateral motion according to the bight data, as it is again lowered from its uppermost position. During such driving control of the bight actuator 47, the thread loop is expanded to its maximum diameter by operation of the looptaker.
Next, the thread take-up start pulse signal SG 4 from thread take-up start pulse generator 37 (i.e. the pulse signal supplied after completion of the thread loop spreading process) is checked in accordance with an instruction 66. If such signal SG 4 is sensed, the CPU provides an instruction to the solenoid drive circuit 51 to de-energize solenoid 32, thereby starting the taking up of the needle thread 26. Simultaneously, the CPU operates to set the number corresponding to the needle thread take-up length, as held in RAM, in an internal counter in the CPU and to subtract the number set in the internal counter one by one in response to the thread take-up timing pulse signal SG 5 from generator 41. When the contents of the internal counter are determined to be equal to zero, in accordance with an instruction 67, the CPU provides a command to the drive cirucit 51 to de-energize the solenoid 62 and to terminate the take-up of needle thread 26. Thus, if the optimum take-up amount as determined by the CPU is 10 cm, the number "20" is set in the internal counter in the form of a binary number. The internal counter of the CPU performs a subtractive operation in response to the thread take-up timing pulse signal SG 5 supplied from generator 41 (one such pulse signal being supplied for each 5 mm of take-up of the needle thread 26 caused by rotation of the drive roller 28), so that the subtractive operation ceases when the twentieth pulse signal SG 5 has been supplied and the counter contents have decreased to zero. As a result, the needle thread 26 is taken up by 10 cm by cooperation of the drive roller 28 and the driven roller 33.
As the solenoid 32 is turned on to enable the thread 26 to be lowered, one stitch is set in the workpiece, and the next instruction 68 is ready to be carried out. If, in accordance with such instruction 68, the switch 16 is determined to be off or out of operation, the CPU executes the above instruction 64 for setting the next stitch. The CPU reads out the bight and feed data sequentially and the selected stitch pattern is formed in the work. The solenoid 32 is turned on and off each time for accurately taking up and down the needle thread 26.
As the sewing work approaches completion, the operator actuates the start stop switch 16. The activated state of the switch 16 is sensed in accordance with the instruction 68, and the needle position sensing signal SG 1 from sensor 23 is checked to determine when the needle 17 is in its upper position. The CPU then provides a stop command to the drive circuit 43 for stopping the needle 17 at the predetermined position. The sewing operation is now completed and the machine operation is stopped.
Simultaneously with the command to de-energize solenoid 32, the CPU provides a control signal to open the electromagnetic valve of the suction device 27 for suction of the thread 26. In addition, simultaneously with the command to energize solenoid 32, the CPU provides a control signal to close the valve. By such arrangement, the length of thread taken up by the drive and driven rollers 28, 33 is held under suction within said suction device 27 to prevent the thread 26 from being entwined about neighboring members due to slack in the upper portion of the thread.
Furthermore, as the operator actuates a lever during sewing to raise the presser foot 18, the signals from sensors 23, 50 are immediately checked in accordance with instruction 70, 71. If such raising of the pressor foot 18 is sensed, the drive motor 44 terminates its operation for operational safety.
Reference is made to FIG. 6 for explanation of the second embodiment of the present invention.
This embodiment differs from the foregoing only as to the manner of driving the drive roller 28, which is described in detail below.
The drive roller 28 is secured to a drive shaft of a stepping motor 81 and, on top of the roller 28, there is provided the solenoid 32 with a driven roller 33 mounted thereon as in the preceding embodiment. On said upper shaft 31 is mounted, in addition to the rotary disc 35, a disc 82 corresponding to the rotary disc 39 for generating the thread take-up timing pulse signals. Twenty through-slits 83 are formed about the circumference of the disc 82 and at equal angular distances from one another, and the rotational travel of these slits 83 is sensed by the light emitting section 41a and the sensor section 41b of the thread take-up timing pulse generator. The disc 82 is located in relation to the disc 35 in such a manner that the rotational travel of the twenty slits 83 in the disc 82 is sensed sequentially at the same time that the generator 37 senses the rotational travel of the slit 36 of the disc 35. In addition, the spacing between adjacent slits 83 of the disc 82 is so selected that a slit 83 is moved between the sections 41a and 41b of the generator 41 each time the thread 26 is taken up 5 mm by the drive roller 28 driven by said stepping motor 81 and cooperating with the driven roller 33.
To the CPU of the micro-computer 42 is connected a thread take-up drive circuit 84 operative to control the driving of the stepping motor 81 as indicated by the broken line in FIG. 3. During the time that the solenoid 32 remains de-energized (the time necessary for taking up the calculated length of the needle thread 26), the drive circuit 84 responds to the respective timing pulse signals from pulse generator 41 to receive from the CPU a step command for driving the stepping motor 81.
Thus, when a pulse signal has been supplied from the pulse generator 37 as described above (that is, upon completion of the expanding process of the thread loop) the solenoid 32 is de-energized and the driven roller 33 energizes the drive roller 28 for clamping the thread 26 therebetween. The stepping motor 81 is simultaneously driven into operation and remains activated until the calculated thread length has been taken up and the solenoid 32 is turned on. Thereafter, at the same time that a command is supplied from the CPU to the drive circuit 51, a stop command is issued to said drive circuit 84 to stop the stepping motor 81. Thus, the motor 81 is stopped and the thread 26 is disengaged from the drive and driven rollers 28, 33. The stepping motor 81 remains deactivated until the next pulse signal is supplied from pulse generator 37.
Various modifications may be made to the automatic adjustment device described above. For example the stepping motor 81 of the second embodiment shown in FIG. 6 may be a reversible motor and the thread take-up drive circuit 84 may be modified for enabling positive supply of needle thread 26 to the needle 17 and take-up of the so supplied thread. The slits used for setting the timing for supply and take-up of the thread 26 may then be formed on the overall circumference of the disc 82. In this modification, the amount of needle thread to be extracted from thread supply 26 is determined by the mechanical structure of the sewing machine and the thread take-up length is calculated by the central processing unit (CPU).
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An automatic thread regulating system having an adjustment mechanism for controlling the thread feed and takeup during the formation of a sewing machine stitch. A central processing unit calculates the length of thread required for a specific stitch formation based on work piece thickness and stitch length. This information is directed to the adjustment mechanism which thereby regulates the appropriate thread amount by feed rolls and a suction apparatus.
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CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a divisional of U.S. patent application No. 11/411,377 filed Apr. 26, 2006, which is a divisional of U.S. patent application No. 11/220,255, filed on Sep. 6, 2005, now U.S. Pat. No. 7,062,392, which is a divisional of application No. 10/251,372, filed Sep. 19, 2002, now U.S. Pat. No. 6,970,794, the entire contents of which are herein incorporated by reference.
BACKGROUND
[0002] Broad classes of semiconductor devices may include several configurations of the same basic device differing in one or more aspects such as output voltage, frequency, trigger temperature, and the like. There are several conventional techniques for providing a specific configuration from a family of devices. In one technique, different versions of the same basic semiconductor are manufactured with slightly different internal component values or configuration to provide the differing outputs. For example, voltage regulators may include a family of devices having various output voltages and tolerance levels. Different devices are manufactured and inventoried by suppliers etc. to provide each of the possible combinations of output voltage and tolerance. An advantage of this approach is that devices with tight tolerances may be provided without the need for expensive external components. However, the cost of the regulators may be higher due to the lower quantities that are produced for each specific voltage/tolerance combination as well as the increased inventory costs.
[0003] Another technique uses one or more external components to complete an internal circuit such as an error amplifier for a voltage regulator. Here, the tolerance of the external components has a direct affect on the tolerance of the output that is generated. To attain an output with a tight tolerance, higher priced tight tolerance external components may be required. In addition, a large selection of the tight tolerance external components may be have to be stocked to provide flexibility in setting the output to the desired value.
[0004] Shown in FIG. 1A is a third technique for configuring a semiconductor 5 . The third technique uses digital input signals to set the semiconductor configuration. Pull-up resistors 6 in combination with switches 7 generate the digital input signals. One digital input may select between two ( 21 ) configurations. Two digital inputs may select between four ( 22 ) configurations. Three digital inputs may select between eight ( 23 ) configurations and so on. To select between a moderate number of configurations, a large quantity of pins may be required. Dedicating four pins merely for selecting between 16 configurations is costly in terms of both, price and package size. Whereas, using two pins for selection may provide reasonable cost and package size, but only provides selection from amongst four configurations.
SUMMARY
[0005] A voltage regulator has a plurality of predetermined configurations and comprises a measurement circuit to measure an electrical characteristic of at least one external impedance and to determine a digital value corresponding to the measured electrical characteristic. An address generator converts the digital value to a first digital address corresponding to a memory location having contents. Each of the contents corresponds to a respective one of the predetermined configurations. A controller configures the voltage regulator based on the contents of the memory location corresponding to the first digital address.
[0006] The details of one or more embodiments of the invention are set forth in the accompanying drawings and the description below. Other features, objects, and advantages of the invention will be apparent from the description and drawings, and from the claims.
DESCRIPTION OF DRAWINGS
[0007] FIG. 1A is a block diagram of a selection circuit connected to a conventional configurable semiconductor.
[0008] FIG. 1B is a block diagram of a configurable semiconductor connected to external impedances.
[0009] FIG. 2 is a detailed block diagram of a configurable semiconductor connected to external impedances.
[0010] FIGS. 3A and 3B are diagrams showing a relationship between an external impedance value and a digital value.
[0011] FIG. 4 is a schematic diagram of a configurable semiconductor having a multifunction pin.
[0012] FIG. 5 is a schematic diagram of a multifunction pin with programmable control.
[0013] FIG. 6 is a schematic diagram of a timing circuit for generating a digital value.
[0014] FIG. 7 shows waveforms associated with the timing circuit of FIG. 6 .
[0015] FIG. 8 is a flow diagram of an operation for configuring a semiconductor.
[0016] FIG. 9 is a flow diagram of an operation for selecting values for external impedances for configuring a semiconductor.
[0017] FIG. 10A is a block diagram of a voltage regulator connected to an external impedance.
[0018] FIG. 10B is a block diagram of a voltage regulator connected to two external impedances.
[0019] Like reference symbols in the various drawings indicate like elements.
DETAILED DESCRIPTION
[0020] FIG. 1B shows a configurable semiconductor device 10 having, for example, two select pins 12 and 14 to connect to two external impedances 16 and 18 . The configurable semiconductor device 10 advantageously uses a reduced number of select pins for interfacing to external components, as compared to conventional devices, to select one or more output and internal characteristics. One or more pins may be used to interface to the external component(s). The configurable semiconductor device probes or derives information from the external components connected to the select pins. The derived information has three or more predetermined level ranges that correspond to selected levels of the device characteristics. For example, a single pin connected to an external resistor may be used to select any one of 16 output voltage levels. The resistance of the external resistor is preferably selected to be one of 16 predetermined standard values. Each of the 16 values of resistance corresponds to one of the 16 output voltage levels. In addition, low precision passive components are preferably used as the external components to reduce cost and inventory. Each external component may have multiple, N, predetermined nominal values that each correspond to the selection of a predetermined characteristic level. If one pin is used, then N different characteristic levels may be selected. If two pins are used, then N*N different characteristic levels may be selected, and so forth for an increasing number of selection pins. The types of device characteristics that for example may be selected include output voltage, reference voltage, output current, reference current, clock frequency, temperature threshold, and tolerances of each of the device characteristics. For example, the configurable semiconductor device 10 may have a single select pin 12 connected to an external resistor that may have a nominal value selected from a group of 16 predetermined values. Each of the 16 predetermined values has a measured value range which corresponds to one of 16 predetermined output voltage levels possibly ranging from 3.3 volts to 15 volts. Examples of functional devices for which the configurable semiconductor device is particularly suitable include and are not limited to voltage regulators, current regulators, clock circuits, and temperature sensing circuits.
[0021] The external impedances 16 and 18 are preferably resistors, capacitors, or combinations of resistors and capacitors, but may be any component that exhibits predominantly an inductance, resistance, capacitance, or combination thereof. The external impedances 16 and 18 may be connected directly or indirectly from any energy source such as Vdd and ground or any suitable reference to the configurable semiconductor device pins 12 and 14 . For example, the external impedance 16 may be connected through a resistor/transistor network to Vdd and through a capacitor network to the select pin 12 .
[0022] The configurable semiconductor device 10 may determine a predetermined select value corresponding to the measured value of the impedance connected to a select pin. Preferably, the impedance is selected to have a standard value such as nominal resistance values corresponding to resistors having a 10% tolerance (e.g. 470, 560, 680, . . . ) to reduce device and inventory costs. To account for measurement tolerances and the tolerance of the external impedance, a range of impedance values may correspond to a single select value. The select value is preferably a digital value, but may also be an analog value. For example, values of measured resistance from 2400 ohms to 3000 ohms may be associated with a digital value corresponding to 2. While values of measured resistance from 3001 ohms to 4700 ohms are associated with a digital value corresponding to 3. The measured resistance includes variations due to tolerances of the external impedance and the internal measurement circuit. The impedance measured at each select pin is used to determine a corresponding digital value. The range of digital values may include 3 or more digital values and preferably range from 10 to 16 digital values per select pin. The digital values corresponding to each select pin may be used in combination to describe memory addresses. For example, a device having three select pins each to interface to impedance values that are mapped into one of 10 digital values, may describe 1000 memory addresses or lookup table values. The contents of the memory addresses are used to set a value for an output or internal characteristic of the device. Another exemplary device may include two select pins, each configured to interface to external impedances that are mapped to a digital value within a range of 10 values. The digital values in combination may describe 100 memory addresses or lookup table values that may each contain data for setting a characteristic of the configurable semiconductor device.
[0023] FIG. 2 shows a block diagram of an aspect of a configurable semiconductor device 20 . The configurable semiconductor device 20 includes a select pin 22 to interface to an external impedance 24 that is used for selecting a configuration of the configurable semiconductor device 20 . The external impedance 24 is similar in function and scope to the external impedances 16 and 18 .
[0024] A measurement circuit 26 connected to the select pin 22 measures an electrical characteristic that is a function of the external impedance 24 . For example, a current may be supplied to the external impedance and the voltage that is developed across the external impedance 24 then measured. Also, a voltage may be impressed across the external impedance 24 and then measure the current. Any measurement technique for measuring passive components may be used to measure the electrical characteristic including dynamic as well as static techniques. Exemplary measurement techniques include timing circuits, analog to digital converters (ADCs), and digital to analog converters (DACs). Preferably, the measurement circuit has a high dynamic range. The measurement circuit 26 may generate an output having a value corresponding to the value of the external impedance 24 . The output may be either digital or analog. The same output value preferably represents a range of external impedance values to compensate for value variations such as tolerances in the external impedance value, interconnect losses, and measurement circuit tolerances due to factors including process, temperature, and power. For example, all measured external impedance values ranging from greater than 22 up to 32 ohms may correlate to a digital output value of “0100”. While measured external impedance values ranging from greater than 32 up to 54 ohms may correlate to a digital output value of “0101”. The actual external impedance values are a subset of the measured external impedance value to account for the value variations. For example, in the above cases the actual external impedance values might be from 24 to 30 ohms and from 36 to 50 ohms. In each case an inexpensive low precision resistor may be selected to have a value centered within the range, such as 27 ohms and 43 ohms. In this way, inexpensive low precision components may be used to select amongst a range of high precision outputs. The select value may be used directly as a variable value to control a device characteristic of the configurable semiconductor 20 . The variable value may also be determined indirectly from the select value.
[0025] A storage circuit 27 may include variable values that may be selected as a function of the select value. The storage circuit may be any type of storage structure including content addressable memory, static and dynamic memory, and look-up tables.
[0026] For the case that the measurement circuit 26 generates output values that have a one-to-one correspondence to the external impedance values, a digital value determiner 28 may then set the output value to a select value that corresponds to a range of external impedance values.
[0027] FIG. 3A shows a relationship between groups of impedance values 50 and associated select values 54 . The groups of impedance values 50 may have a one-to-one correspondence to groups of digital output values 52 which are converted to the select values 54 associated with each of the groups of impedance values 50 . The impedance values ranging from a minimum impedance value to a maximum impedance are separated in into three or more groups, with each group having a nominal impedance. The nominal impedance values of each of the groups may be selected to have a spacing between nominal impedance values. Here, the nominal values, 27 ohms and 43 ohms, of the groups of impedance values have a spacing of 16 ohms. The spacing between the groups of impedance values is preferably based on geometric progression, however any mathematical relationship may be used to establish spacing between the groups such as logarithmic, linear, and exponential. The spacing between impedance groups may be based on any impedance value of the groups including a nominal value, an average value, a mean value, a starting value, and an ending value. Factors that influence selection of the impedance range of the groups and the spacing may include various tolerances such as the tolerance of the external impedance, the tolerance of internal voltage and current sources, and the tolerance of the measurement circuit. The tolerances may for example be caused by process, temperature, and power variations.
[0028] FIG. 3B shows a relationship between ranges of impedance values 56 and associated select values 58 . The ranges of impedance values 56 have a direct correspondence to the select values 58 . The impedance values ranging from a minimum impedance value to a maximum impedance are separated in into three or more groups, with each group having a nominal impedance. The nominal impedance values of each of the groups may be selected to have a spacing between nominal impedance values. Here, the nominal values, 27 ohms and 43 ohms, of the groups of impedance values have a spacing of 16 ohms. This direct correspondence between the ranges of impedance values 56 and associated select values 58 may be implemented by, for example, a nonlinear analog to digital converter (not shown).
[0029] Referring back to FIG. 2 , an address generator 30 may determine memory locations corresponding to the digital output values associated with external impedances connected to the select pins. The memory locations may be grouped in any manner such as a list for a single select pin, a lookup table for two select pins, and a third order table for three select pins.
[0030] A controller 32 sets a device characteristic of the configurable semiconductor device 20 as a function of the variable value. The variable value may be generated directly by the measurement circuit, determined indirectly from the select value, and determined from the contents of a memory location corresponding to the external impedance values connected to the select pins.
[0031] FIG. 4 shows an aspect of another configurable semiconductor device 60 . Configurable semiconductor device 60 is similar to configurable semiconductor device 20 in function, except that configurable semiconductor device 60 includes at least one multi-purpose select pin 62 . The multi-purpose select pin 62 may be used for configuring the semiconductor device 60 as well as for an additional function such as power down (PD), power enable, mode selection, reset, and synchronous operation. The semiconductor device 60 may be configured in a manner similar to that of configurable semiconductor device 20 .
[0032] In one aspect, a first range of impedance values connected to the multi-purpose select pin 62 may be used to configure the configurable semiconductor device 60 , while operation of the additional function may be controlled by a voltage or current impressed on the multi-purpose select pin, or impedance values outside the first range of impedance values.
[0033] An external impedance 64 and a switch 66 may be connected to the multi-purpose select pin 62 to provide the selection function and the additional function respectively. Bias voltages, Vb 1 and Vb 2 , may be applied to the external impedance 64 and transistor 66 . The bias voltages, Vb 1 and Vb 2 , may each be any value ranging from negative voltage through ground to positive voltage, and equal or not equal. The switch 66 may be connected in any manner including from the multi-purpose select pin 62 to ground, from the multi-purpose select pin 62 to a voltage source, from the multi-purpose select pin 62 to a current source, and from the multi-purpose select pin 62 through another impedance to an energy source. Any type of switch or device configured as a switch may be used including transistors, analog switches, jumper wires/traces, and manual switches.
[0034] FIG. 5 shows a configurable semiconductor device 70 coupled to a digital control circuit 72 . The digital control circuit 72 may be connected in any manner such as a stand-alone circuit and included in another device such as a processor. The configurable semiconductor device may include a multi-purpose select pin 74 similar in function to configurable semiconductor device 60 . The digital control circuit 72 may include several switches 76 to control external impedances 78 for setting an impedance on the multi-purpose select pin 74 . Any number and type of switches 76 may be employed including transistors, analog switches, jumper wires/traces, and manual switches. Preferably, the external impedances 78 are selected to have standard values although any range of values may be used. Another transistor 80 may control operation of additional functions.
[0035] FIG. 6 shows one embodiment of a measurement circuit 100 for determining a digital output 106 corresponding to an external impedance 102 . The external impedance 102 may be connected to the measurement circuit 100 through a select pin 104 . Table I shows exemplary values for the external impedance 102 and corresponding values of the digital output. Predefined operation # 2 may enable the power down function. The impedance at the select pin that corresponds to predefined operations # 1 or # 2 may be intentional or unintentional such as a selected resistor, a cold solder joint, a broken trace, shorted traces, or a failed external device.
TABLE I Digital # Rx/Ry Vout Vout % Output 0 Short to Vss up 0 0 Predefined to 10k operation #1 1 19.6k 0.8 −2 000 2 28.5k 1.0 −4 001 3 40k 1.2 −6 010 4 56k 1.5 −8 011 5 80.6k 1.8 +2 100 6 113k 2.5 +4 101 7 160k 3.0 +6 110 8 226k 3.3 +8 111 9 400k to an open Predefined operation #2
[0036] FIG. 7 shows a timing diagram associated with the measurement circuit 100 . A first waveform 120 represents a clock signal 120 to the D flip-flop 110 . A second waveform 122 represents an input signal to the D input of the flip-flop 110 . In operation, a controlled resistor 112 is initially set to a predetermined value. A first voltage is developed at a first node 114 as a function of the controlled resistor 112 and the external impedance 102 . The first voltage is clocked through the flip-flop 110 by the clock signal 120 . An incrementer/decrementer 116 may convert the output of the flip-flop 110 to the digital output 106 . In response to the digital output 106 , a decoder 118 adjusts the controlled resistor 112 to decrease the first voltage. The counter continues to increment until the first voltage decreases to a level equivalent to a logic “0”.
[0037] FIG. 8 shows an operation of a configurable semiconductor device. Starting at block 150 , energy is supplied to an external impedance. Continuing to block 152 , an electrical characteristic that is a function of the external impedance is measured. Electrical characteristics such as a voltage at the select pin and a current flowing through the select pin may be measured. At block 154 , a select value corresponding to the measured electrical characteristic is determined. Continuing to block 156 , an address may be generated as a function of the digital value. At block 158 , the contents of the address are determined. At block 160 , a variable may be controlled as a function of the select value such as directly and based on the address contents. At block 162 , a device characteristic such as an output voltage may be controlled as a function of the variable.
[0038] FIG. 9 shows an operation for selecting the spacing of external impedances used for configuring a semiconductor device. The spacing is preferably selected to permit the use of low precision components by varying the spacing from lower values to higher values to account for potential variations associated with the measurement circuit. Starting at block 200 , a measurement circuit is provided. Continuing to blocks 202 and 203 , tolerances associated with the measurement circuit and the external impedances may be determined. The tolerances may include variations due to process, temperature, and power. At block 204 , a measurement error such as a geometric progression, a maximum error, and root of the sum of the squares (RSS) error may be computed. Continuing to block 206 , a quantity of discrete values for the external impedance may be determined. For example, the measurement error may be applied across a voltage range of the measurement circuit to determine the maximum number of discrete values that may be selected. The quantity of discrete values may be any integer value greater than one. At block 208 , nominal values are selected for the external impedance as a function of the computed error and the selected quantity of discrete values. The described operation is not limited to the described order of operation. Other ones of the variables may be solved for such as solving for the tolerance of the external impedance after selecting a desired quantity of discrete values.
[0039] FIG. 10A is an example of a voltage regulator in accordance with the present invention. Referring now to FIG. 10A a voltage regulator 200 is shown therein providing Vout to load 210 , an external impedance 220 is used to select Vout. Table II shows exemplary values for the external impedance 220 and corresponding values of Vout. Predefined operation # 2 may enable the power down function or low voltage to protect for an overvoltage condition presented to load 210 . The impedance at the select pin that corresponds to predefined operations # 1 or # 2 may be intentional or unintentional such as a selected resistor, a cold solder joint, a broken trace, shorted traces, or a failed external device.
TABLE II # Impedance 220 Vout 0 Short to Vss up 0 or power to 10k down 1 19.6k 0.8 2 28.5k 1.0 3 40k 1.2 4 56k 1.5 5 80.6k 1.8 6 113k 2.5 7 160k 3.0 8 226k 3.3 9 400k to an open 0 or low voltage
[0040] FIG. 10B is an example of a voltage regulator in accordance with the present invention. Referring now to FIG. 10B a voltage regulator 200 is shown therein providing Vout to load 210 , an external impedance 220 is used to select a nominal Vout and impedance 240 is used to select the offset from the nominal Vout. This provides for a significant number of additional output voltages. Table III shows exemplary values for the external impedance 220 and corresponding values of the offset percentages. If impedance 240 is a large value or perhaps an open circuit no offset will be applied to the nominal Vout. While if impedance 240 is a short or very low a predefined operation, such as discussed above, is implemented.
TABLE III Offset # Impedance 240 percentage 0 Short to Vss up Predefined to 10k operation 1 19.6k −2 2 28.5k −4 3 40k −6 4 56k −8 5 80.6k +2 6 113k +4 7 160k +6 8 226k +8 9 400k to an open No Offset
[0041]
TABLE IV
Short to
Vss up
to 10k
19.6k
28.5k
40k
56k
80.6k
113k
160k
226k
400k to
Imped
Imped
Nominal
Offset %
an
240
220
Vout
0
−2
−4
−6
−8
+2
+4
+6
+8
open
Short
0 or
0 or
0 or
0 or
0 or
0 or
0 or
0 or
0 or
0 or
0 or
0 or
toVss
power
power
power
power
power
power
power
power
power
power
power
power
up to
down
down
down
down
down
down
down
down
down
down
down
down
10k
19.6k
0.8
0.8
*
0.784
0.768
0.752
0.736
0.816
0.832
0.848
.0864
0.8
28.5k
1.0
1.0
*
0.980
0.960
0.940
0.920
1.020
1.040
1.060
1.080
1.0
40k
1.2
1.2
*
1.176
1.152
1.128
1.104
1.224
1.248
1.272
1.296
1.2
56k
1.5
1.5
*
1.470
1.440
1.410
1.380
1.530
1.560
1.590
1.620
1.5
80.6k
1.8
1.8
*
1.764
1.728
1.692
1.656
1.836
1.872
1.908
1.944
1.8
113k
2.5
2.5
*
2.450
2.400
2.350
2.300
2.550
2.600
2.650
2.700
2.5
160k
3.0
3.0
*
2.940
2.880
2.820
2.760
3.060
3.120
3.180
3.240
3.0
226k
3.3
3.3
*
3.234
3.168
3.102
3.036
3.366
3.432
3.498
3.564
3.3
400k
0 or
0 or
0 or
0 or
0 or
0 or
0 or
0 or
0 or
0 or
0 or
0 or
to an
low
low
low
low
low
low
low
low
low
low
low
low
open
voltage
voltage
voltage
voltage
voltage
voltage
voltage
voltage
voltage
voltage
voltage
voltage
* predefined operation
[0042] Table IV above is an example of the nominal Vout and the offset percentage selected in accordance with external impedances. For example if impedance 220 is nominally 160 k ohms the nominal Vout is 3.0 volts and if impedance 240 is 28.5 k the offset from the nominal Vout is −4%. This results in a Vout of the voltage regulator of 3.168 volts.
[0043] A number of embodiments of the invention have been described. Nevertheless, it will be understood that various modifications may be made without departing from the spirit and scope of the invention. Accordingly, other embodiments are within the scope of the following claims.
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A voltage regulator having a device characteristic comprises a first terminal connectable to a first external impedance. A measurement circuit communicates with the first terminal to measure the first external impedance. A control circuit controls the device characteristic as a function of the measured first external impedance.
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CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is based on and claims priority from Korean Patent Applications No. 10-2011-0071343, filed on Jul. 19, 2011 and No. 10-2012-0018591, filed on Feb. 23, 2012 with the Korean Intellectual Property Office, the present disclosure of which is incorporated herein in its entirety by reference.
TECHNICAL FIELD
[0002] The present disclosure relates to a nitride electronic device and a method for manufacturing the same, and particularly, to a nitride electronic device and a method for manufacturing the same that can implement can implement various types of nitride integrated structures on the same substrate through a regrowth technology (epitaxially lateral over-growth: ELOG) of a semi-insulating gallium nitride (GaN) layer used in a III-nitride semiconductor electronic device including Group III elements such as gallium (Ga), aluminum (Al) and indium (In) and nitrogen.
BACKGROUND
[0003] A gallium nitride (GaN)-based compound semiconductor is a direct transition type semiconductor and can control a wavelength from visible rays to ultraviolet rays. The gallium nitride-based compound semiconductor has high thermal and chemical stability and high electron mobility and saturated electron velocity. The gallium nitride-based compound semiconductor has excellent physical properties such as a large energy band gap as compared to known gallium arsenic (GaAs) and indium phosphorus (InP)-based compound semiconductors. On the basis of these properties, an application range of the gallium nitride-based compound semiconductor has been expanded to optical devices such as light emitting diodes (LEDs) of a visible ray region and laser diodes (LDs), and the next-generation wireless communication and satellite communication systems requiring high power and high frequency properties, which are fields having a limitation when using known compound semiconductors.
[0004] Performance of a gallium nitride-based electronic device is determined by an epitaxial structure, a process technology such as ohmic contact by a low resistance metal material and Schottky contact having high bather potential and a device design for determining a range of high frequency operation and current operation. Here, the epitaxial structure includes a barrier layer constituted by aluminum gallium nitride (AlGaN), indium aluminum nitride (InAlN), aluminum nitride (AlN) and the like, a channel layer used as an electron movement path and a semi-insulating layer for device isolation and reduction in leakage current.
[0005] However, when implementing integrated structures having various properties on a single substrate at the same time, there are many limitations in designing of the epitaxial structure, a device process and designing of a device, which is an obstacle to implementing a GaN-based electronic device.
[0006] Accordingly, in order to manufacture a GaN-based field effect transistor (FET), it is necessary to develop an epitaxial structure, a process technology and a device design technology that can manufacture various FET devices on a single substrate.
SUMMARY
[0007] The present disclosure has been made in an effort to provide an electronic device which has structures differently having channel layers and barrier layers through a regrowth technology using a GaN layer as a semi-insulating layer and regrowth, and has integrated structures with various properties, which are implemented on a single substrate using a unit process and a design technology, and a method for manufacturing the same.
[0008] An exemplary embodiment of the present disclosure provides a nitride electronic device, including: a first nitride integrated structure in which a low temperature buffer layer, a first semi-insulating nitride layer, a first channel layer and a first barrier layer are sequentially stacked on a substrate, and the first semi-insulating nitride layer is partially etched; and a second nitride integrated structure in which a second semi-insulating nitride layer, a second channel layer and a second barrier layer are sequentially stacked on a part where the first semi-insulating nitride layer is partially etched.
[0009] Another exemplary embodiment of the present disclosure provides a method for manufacturing a nitride electronic device, including: forming an epitaxial structure in which a low temperature buffer layer, a first semi-insulating nitride layer, a first channel layer and a first barrier layer are sequentially stacked on a substrate; stacking a first dielectric layer for forming a pattern on the first barrier layer and partially etching the first barrier layer, the first channel layer and the first semi-insulating nitride layer; regrowing a second semi-insulating nitride layer on the etched first semi-insulating nitride layer; sequentially stacking a second channel layer and a second barrier layer on the second semi-insulating nitride layer; stacking a second dielectric layer for forming a pattern on the second barrier layer and etching the second barrier layer, the second channel layer and the second semi-insulating nitride layer; and removing the first and second dielectric layers and stacking metal electrode layers on the first and second barrier layers.
[0010] According to the exemplary embodiments of the present disclosure, it is possible to obtain the following various effects by integrating various types of devices using a semi-insulating GaN layer that isolates devices and limits leakage current in an electronic device.
[0011] It is possible to implement a compound semiconductor integrated circuit in which various types of devices are simultaneously manufactured on a single substrate using a regrowth technology.
[0012] Since different kinds of epitaxial structures may be grown, it is possible to form, as necessary, various types of electronic devices such as integration of high frequency devices having different operating frequencies, integration of a depletion mode (normally-on) device and a enhancement mode (normally-off) device by adjusting a thickness of a barrier layer, integration of a high frequency device constituted by a channel layer and a barrier layer and a high current device constituted by a channel layer or a Schottky diode and the like.
[0013] As electronic devices are integrated vertically, a degree of integration of devices in the same area may be improved as compared to a known horizontal device arrangement, and when a semiconductor integration process is used, the surface planarization may be achieved in a horizontal direction, and devices may be integrated in a vertical direction.
[0014] The foregoing summary is illustrative only and is not intended to be in any way limiting. In addition to the illustrative aspects, embodiments, and features described above, further aspects, embodiments, and features will become apparent by reference to the drawings and the following detailed description.
BRIEF DESCRIPTION OF THE DRAWINGS
[0015] FIG. 1 is a cross-sectional view illustrating a structure of a GaN electronic device according to the present disclosure.
[0016] FIGS. 2 to 9 are a process flowchart illustrating a method for manufacturing a GaN electronic device according to the present disclosure.
[0017] FIG. 10 is a cross-sectional view illustrating a structure of a GaN electronic device which includes only barrier layers by omitting a first channel layer and a second channel layer from the structure of the GaN electronic device of FIG. 1 .
[0018] FIG. 11 is a cross-sectional view illustrating a structure of a GaN electronic device in which a first integrated structure in the structure of the GaN electronic device of FIG. 1 is constituted by only a channel layer, and a second integrated structure is constituted by a channel layer and a barrier layer.
[0019] FIG. 12 is a cross-sectional view illustrating a structure of a GaN electronic device in which a first integrated structure in the structure of the GaN electronic device of FIG. 1 is constituted by a channel layer and a barrier layer, and a second integrated structure is constituted by only a channel layer.
[0020] FIG. 13 is a cross-sectional view illustrating a structure of a GaN electronic device which includes only channel layers by omitting a first barrier layer and a second barrier layer from the structure of the GaN electronic device of FIG. 1 .
DETAILED DESCRIPTION
[0021] In the following detailed description, reference is made to the accompanying drawing, which form a part hereof. The illustrative embodiments described in the detailed description, drawing, and claims are not meant to be limiting. Other embodiments may be utilized, and other changes may be made, without departing from the spirit or scope of the subject matter presented here.
[0022] Hereinafter, exemplary embodiments of the present disclosure will be described in detail with reference to the accompanying drawings. The configuration of the present disclosure and operational effect thereof may be apparently understood through the following detailed description.
[0023] Prior to the detailed description of the present disclosure, it is noted that the same reference numerals refer to the same elements throughout the specification even though the same elements are shown in the other drawing, and known constitutions may not be described in detail if they make the gist of the present disclosure unclear.
[0024] FIG. 1 illustrates a cross-sectional view of a GaN electronic device according to an exemplary embodiment of the present disclosure.
[0025] As illustrated in FIG. 1 , the GaN electronic device according to the exemplary embodiment of the present disclosure includes a sapphire substrate 101 , a low temperature buffer layer 102 , a first semi-insulating GaN layer 103 , a first channel layer 104 , a first barrier layer 105 , a second semi-insulating GaN layer 107 , a second channel layer 108 , a second barrier layer 109 , an ohmic contact layer-source electrode layer 111 , an ohmic contact layer-drain electrode layer 112 and a Schottky contact layer-gate electrode layer 113 .
[0026] According to the exemplary embodiment of the present disclosure, the second semi-insulating GaN layer 107 is used so as to ensure device isolation and reduction in leakage current of the GaN electronic device, and properties of electrical insulation and device isolation between first and second GaN integrated structures are implemented through a regrowth process of the second semi-insulating GaN layer 107 , thereby manufacturing an electronic device capable of implementing the same kind of or different kinds of various devices together on the same substrate.
[0027] FIGS. 2 to 9 illustrate a manufacturing process of the GaN electronic device according to the exemplary embodiment of the present disclosure.
[0028] Describing the manufacturing process of the GaN electronic device, a basic epitaxial structure is first formed. The epitaxial structure is formed by sequentially stacking the low temperature buffer layer 102 , the first semi-insulating GaN layer 103 , the first channel layer 104 for electron movement and the first barrier layer 105 forming a 2-dimensional electron gas (2-DEG) layer on the sapphire substrate 101 .
[0029] Thereafter, in an etching process for device integration, after patterning a first SiO 2 layer or a first SiN x layer 106 using a first mask, the first channel layer 104 and the first barrier layer 105 are etched. Then, the second semi-insulating GaN layer 107 is regrown on the first semi-insulating GaN layer 103 which is exposed. After two-dimensional surface growth is completed, the second channel layer 108 and the second barrier layer 109 are sequentially stacked. In this case, epitaxial properties of the semi-insulating GaN layer, the channel layer and the barrier layer, which are grown separately, are determined according to properties of devices to be integrated on the single substrate, and various types of devices may be integrated.
[0030] When the regrowth is completed, a second SiO 2 layer or a SiN x layer 110 is deposited, and then patterned oppositely to patterning using the first mask. Next, an etching process is performed up to the first SiO 2 layer or the SiN x layer 106 , and the SiO 2 layer or the SiN x layer 106 which is exposed is removed.
[0031] Thereafter, an electrode layer for manufacturing an electronic device is formed. In this case, a Schottky electrode of a gate electrode is formed after forming ohmic contact of a source electrode and a drain electrode according to a design of a device pattern. The same type of or different types of GaN devices may be integrated on a single substrate based on the above-mentioned processes.
[0032] FIG. 2 illustrates an epitaxial structure layer that is a basic structure of an electronic device using a GaN compound semiconductor. The epitaxial structure layer has a structure in which a sapphire substrate 101 , a low temperature buffer layer 102 , a first semi-insulating GaN layer 103 , a first channel layer 104 and a first barrier layer 105 are sequentially stacked.
[0033] Describing steps of a manufacturing process of the epitaxial structure layer, the low temperature buffer layer 102 is first grown on the sapphire substrate 101 . Thereafter, the first semi-insulating GaN layer 103 is grown on the low temperature buffer layer 102 to have a thickness of 2 to 3 μm so as to electrically insulate electronic devices and reduce leakage current. The first semi-insulating GaN layer 103 is grown to have an epitaxial structure which has high resistivity by changing a growth speed of high temperature GaN or controlling a growth mode of GaN.
[0034] Then, the first channel layer 104 is grown on the first semi-insulating GaN layer 103 . The first channel layer 104 is a path through which electrons forming an current flow in an electronic device move between electrode layers, and in order for the first channel layer 104 to have high mobility, no impurities is doped or a minimum amount of dopant is used. The first channel layer 104 may be constituted by a ternary compound semiconductor including indium (In) or aluminum (Al) so as to increase an effect of interrupting leakage current and limiting current.
[0035] Then, the first barrier layer 105 is grown on the first channel layer 104 . The first barrier layer 105 is mainly constituted by a ternary (Al x Ga 1-x N, In x Ga 1-x N, In x Al 1-x N) or quaternary (In x Al y Ga 1-x-y N) compound semiconductor. In this case, a composition ratio of elements and a thickness of the barrier layer are determined according to performance required for the GaN electronic device. In a high frequency electronic device, an Al x Ga 1-x N barrier layer is mainly used, a composition ratio of Al is in the range of 20 to 40%, and a thickness thereof is in the range of 10 to 40 nm.
[0036] FIGS. 3 and 4 illustrate a step of forming a pattern and an etching step for regrowing semi-insulating GaN.
[0037] Referring to FIG. 3 , a first dielectric layer 106 is used to form a pattern, and in this case, a thickness of the dielectric layer is in the range of 0.1 to 0.2 μm. SiO 2 or SiN x may be used for the first dielectric layer 106 .
[0038] Referring to FIG. 4 , an etching thickness is up to a depth at which the first semi-insulating GaN layer 103 is exposed and is generally in the range of 0.1 to 0.5 μm. FIG. 4 illustrates a first integrated structure.
[0039] Referring to FIG. 5 , the second semi-insulating GaN layer 107 is regrown on the surface of the etched first semi-insulating GaN layer 103 , and the second channel layer 108 and the second barrier layer 109 are stacked in sequence. In this case, a total thickness of the grown second integrated structure needs to be within the range of 1 μm in consideration of pattern work. The detailed configuration of the second channel layer 108 and the second barrier layer 109 is similar to that of the first channel layer 104 and the first barrier layer 105 and needs to be designed depending on properties of the GaN electronic device.
[0040] FIGS. 6 to 9 simply illustrate steps of a manufacturing process of the GaN electronic device.
[0041] Referring to FIG. 6 , a second dielectric layer 110 for an etching process is formed. In this case, the pattern formed is opposite to that of the first dielectric layer 106 . SiO 2 or SiN x may be used for the second dielectric layer 110 .
[0042] Referring to FIG. 7 , an etching process is performed up to the first dielectric layer 106 . Referring to FIG. 8 , the first dielectric layer 106 and the second dielectric layer 110 used for forming the patterns are removed. Referring to FIG. 9 , ohmic metal electrode layers 111 and 112 are stacked, and then Schottky metal electrode layers 113 are stacked according to a design structure of the GaN electronic device, thus manufacturing the GaN electronic device of FIG. 1 .
[0043] FIGS. 10 to 13 illustrate various types of electronic device structures based on the structure of the GaN electronic device illustrated in FIG. 1 .
[0044] FIG. 10 illustrates a structure in which the first channel layer 104 and the second channel layer 108 are omitted. In the high frequency electronic device, a channel layer may be omitted depending on properties of the first semi-insulating GaN layer 103 and the second semi-insulating GaN layer 107 .
[0045] FIG. 11 illustrates a structure in which the first barrier layer 105 is omitted, and FIG. 12 illustrates a structure in which the second barrier layer 109 is omitted.
[0046] Most of the electronic devices including a barrier layer have a high electron mobility transistor (HEMT) structure, and an electronic device without a barrier layer has a metal semiconductor field effect transistor (MESFET) structure having a high current driving property.
[0047] FIG. 13 illustrates a structure including only channel layers by omitting both the first barrier layer and the second barrier layer. FIG. 13 illustrates a structure in which the same kind or different kinds of metal semiconductor field effect transistors are integrated according to properties of the channel layer.
[0048] From the foregoing, it will be appreciated that various embodiments of the present disclosure have been described herein for purposes of illustration, and that various modifications may be made without departing from the scope and spirit of the present disclosure. Accordingly, the various embodiments disclosed herein are not intended to be limiting, with the true scope and spirit being indicated by the following claims.
|
The present disclosure relates to a nitride electronic device and a method for manufacturing the same, and particularly, to a nitride electronic device and a method for manufacturing the same that can implement various types of nitride integrated structures on the same substrate through a regrowth technology (epitaxially lateral over-growth: ELOG) of a semi-insulating gallium nitride (GaN) layer used in a III-nitride semiconductor electronic device including Group III elements such as gallium (Ga), aluminum (Al) and indium (In) and nitrogen.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The invention relates to a support and connecting profile comprised of synthetic material, synthetic resin, phenol and/or light metal for a self-supporting framework, and in particular, for light construction of hangars and large tent structures.
2. Description of the Related Art
Profiles are used for bearing and supporting structures, and in particular for small tents. Apart from structures in which the profiles are erected together with a tent skin to secure the profiles in position, self-supporting frameworks over which is pulled a roof skin are also known. In WO 93/15293, a portable tent system is described with an envelope shielded against radio frequencies, whose frame forms a self-supporting framework of fiberglass poles.
For large tents employed outside or for light construction hangars, in contrast, most often steel or aluminum profiles are used for constructing a self-supporting framework in order to absorb the greater forces occurring in large structures. In particular steel, but also aluminum, profiles with satisfactory strength have a comparatively heavy weight which makes the erection and disassembly of large tent structures, as well as their transport, difficult.
DE 34 13 069 C2 discloses support poles comprising fiberglass-reinforced synthetic material, which can be used inter alia for large capacity tents and skeleton-like structures. For this purpose, the support poles, for example, are completely pervaded by a fiberglass fabric, fiberglass spun threads, or fiberglass rovings extending through the profile in the axial and radial directions, that are used as reinforcement elements. The support profile also comprises additional statistically distributed fiberglass segments. With them, support profiles are intended to be formed which have high loading capacity in the axial direction, as well as in the radial direction.
SUMMARY OF THE INVENTION
The task of the present invention is to provide a support and connecting profile of the above described type for framework structures, which is especially adapted to its function and is rugged and not subject to damage even at low weight and under high loading.
This task is solved with the present invention in that the profile body or in specific regions thereof comprises reinforcements of a fiber composite, for example, glass, carbon or aramid fibers, applied onto or introduced into the profile body.
By means of the reinforcements purposefully integrated into the profile body, regions, especially those subject to local loading, of the nevertheless extremely light profile, in the skeleton structure can be especially reinforced or adapted thereby to differing stresses without any change in cross section, while the remaining regions, for reasons of cost, can remain unreinforced. Depending on the function of the profile in the structure, different loadings occur. Apart from axial loads, essentially acting axially onto the perpendicular support profiles, connecting profiles also absorb, for example, shearing forces, in order to prevent a collapse of the skeleton. In particular, at the fastening and connecting sites of the profile, high forces occur. According to the present invention, these forces can be absorbed through special reinforcements, which are each adapted to the magnitude of the force acting upon it. Therefore, the present invention not only makes it possible to apply individual support poles of a light material, for example, fiberglass-reinforced synthetic material, in the erection of skeletons for light construction of hangars and big tents, but also to erect the self-supporting skeleton entirely, or at least largely, of synthetic material or light metal profiles, which, compared to solid metal profiles, are significantly lighter. In particular, synthetic material profiles are also more elastic than metal profiles such that relatively large impacts, for example, if individual parts are dropped during the assembly, do not lead to permanent deformations.
The reinforcements can be variably applied if they are developed as strips or the like, which can be fastened or introduced by adhesion, bolts or rivets on or in the profile body. The strips can be applied only on one: side of the profile body. Especially high flexural strength can be attained, however, if reinforcements, for example, in the form of strips, are applied on two opposing sides on either the inside or the outside of the profile body.
For simple positioning, the profile body can comprise recesses or indentations for receiving the reinforcements. These recesses or indentations additionally strengthen the profile body itself The profile bodies can be developed as hollow profiles of synthetic material or as hollow aluminum profiles.
The profile body comprising additionally defined reinforcements is preferably developed as a continuous glass or carbon fiber profile. In this implementation according to the invention, the unreinforced synthetic material profile already has a high degree of rigidity at low weight. In this case, the reinforcements can especially advantageously be woven into the glass or carbon fiber fabric of the profile body, whereby high spot reinforcements can also be attained.
To attain a high refractory quality of the profile, chemicals having low flammability can be added to the glass or carbon fiber profile body. In this way, the guidelines applying inter alia to the erection and operation of tents can be observed. The guidelines laid down for Germany require that all building materials according to DIN 4102 Part 1 must at least be flame-resistant. Only for roofing, which is higher than 2.30 m above pedestrian areas, is it normally allowed that inflammable building materials according to DIN 4102 Part 1 are used. In Europe, the US, Japan. and East Asia, no specific legislation exists for tents. The tents are to some extent treated like other structural installations, i.e., they are also subject to the fire protection provisions for such structural installations. These require to some extent that the buildings must be able to withstand fire for 30 or 60 minutes. Aluminum and steel alone cannot achieve this; rather, they become deformed or they begin to melt. For the addition of corresponding chemicals, such as aluminum trihydrate, bromine or the like, to the synthetic resin, such as phenol, in the case of glass or carbon fiber structures, every fire classification can be attained such that every national requirement can be met.
The reinforcements can be introduced especially simply in a synthetic profile body produced by pultrusion. Even the reinforcements comprised of fiber composite materials can be produced simply by pultrusion. In a further development of the invention, the profile body is dyed throughout. In this way, color fastness is not impaired by scratches and slight damage to the profile body.
According to the invention, the profile body can be developed as a post, roof girder, gable support, gable cross transverse, roof beam, cloth holder, post shoe, gable support with bottom securement, strut girder connection in the gutter region, roof ridge connection between individual roofgirders, connecting part between gable supports and roof girders, cross bracing for rigidification between posts and between roof girders or the like framework parts. In this way, the self-supporting skeleton can be constructed entirely of synthetic profiles of the type according to the invention.
Further characteristics, advantages and application feasibilities of the invention are evident in the following description of embodiment examples and the drawings. All described characteristics by themselves or in any combination form the subject matter of the invention independently of their recapitulation in the claims or their reference below.
BRIEF DESCRIPTION OF THE DRAWINGS
The drawings depict:
FIG. 1 is across section through a support and connecting profile according to the invention with reinforcements; and
FIG. 2 is a cross section through a further implementation of a support and connecting profile according to the invention with reinforcements.
DETAILED DESCRIPTION OF THE INVENTION
A support or connecting profile 1 for erecting a self-supporting skeleton for light construction hangars and large tents is a synthetic profile, for example, comprised of polyester, epoxy, acrylic or vinyl resin, which is reinforced by fiber composite materials, integrated into the resin molding material, such as glass, carbon or aramid. These synthetic profiles are employed for posts, standing perpendicular on the ground, as well as for roof structures, for example, a gable roof, which rests on the perpendicular posts. Between the posts, as well as in the roof structure between the profiles bearing the load, connecting profiles for making the skeleton-like framework rigid are necessarily applied. These connecting profiles are also comprised of fiberglass-reinforced synthetic material. Since the specific weight of fiberglass is only approximately 30% of the specific weight of aluminum, the weight of the entire skeleton can be reduced considerably by using synthetic material profiles. This facilitates the transport and the erection of the skeleton for light construction hangars and large tents, whereby costs are reduced to a considerable extent, and leads to a decrease of the load resting on the support posts, whereby the construction of the skeleton is simplified.
However, shearing forces, for example, due to wind on the tent or the hangar, cause, at the connecting sites between the support and connecting profiles, forces to act obliquely onto the profiles. In order for the synthetic profile to be able to absorb these high forces, as well as others, at specific sites or regions of the skeleton structure, according to the invention, special reinforcements are introduced at these sites or regions into synthetic profile body 5 . These are, for example, woven into the fiberglass fabric of the synthetic profile body 5 . As a function of direction and magnitude of the forces exerted, these special reinforcements can be glass, carbon or aramid fibers or also synthetic wires.
To form the synthetic profile 1 with respect to color, coloring substances are added directly to the resin molding material, such that the synthetic profile body 5 is dyed completely throughout. In contrast to metal profiles which are only color coated or painted, scratches or slight damage do not lead to esthetic losses. Such synthetic profiles are therefore, also especially maintenance-friendly.
FIG. 1 shows in cross section the profile 1 developed as a hollow aluminum profile. The profile 1 is substantially rectangular and comprises at particular corners, circular grooves 2 opened toward the outside, in which, for example, fastening elements, not shown, can be applied. At opposing narrow sides 3 of the profile body 5 developed as a hollow profile, carbon fiber reinforcements 4 developed in the form of strips are applied by adhesion, bolts or rivets on the inside between two grooves 2 .
FIG. 2 shows a comparable profile body 5 which is also rectangular and comprises, at the four corners, corresponding grooves 2 . In this profile body 5 in the center of broad sides 6 , opposing flat recesses 7 are developed in which strip-like carbon fiber reinforcements 8 are received. Through the application or introduction of the carbon strips 4 , 8 onto the hollow profile body 5 , the hollow profile body's flexural rigidity can be substantially increased with an insignificant increase of the weight. Therein, the profile body 5 developed as a hollow profile forms the basic profile. The profile body 5 is reinforced such that at the inside and/or outside on two opposing sides 3 or 6 , reinforcements 4 , 8 are fastened in the recesses 7 as strips of, for example, pultruded carbon fibers by, for example, adhering, bolting or riveting them on. A weight advantage can be attained such that when using a relatively thin (lighter) aluminum profile in connection with the reinforcement of carbon fibers, greater values for tensile strength, compressive strength, modulus of elasticity and flexural rigidity can be attained.
In a typical extruded aluminum profile with dimensions of 130×70 mm and a wall thickness of 3 mm, the rigidity is increased from approximately 70 Npa to 120 Npa by installing two strips with the dimensions of 80×1.2 mm at the opposing sides of the profile body 5 . An extruded aluminum profile with a weight of approximately 4 kg per meter run yields approximately the same technical values as a thicker aluminum profile having a weight of approximately 6 kg per meter run.
With profiles specifically reinforced at sites or regions especially subject to loading, it is consequently possible to erect in a simple manner, self-supporting skeletons in particular for light construction hangars and large tent structures, which, at high bearing capacity, have low true specific weight due to the comparatively light aluminum or synthetic profiles.
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The invention relates to a support and a connecting profile made of plastic, synthetic resin, phenol and/or light metal for a self-regulating skeleton, in particular for halls constructed from light materials and large tent constructions, characterized in that the profile body ( 5 ) is provided with reinforcements ( 4,8 ) on or introduced in certain areas and which are made of fiber composite materials, e.g. glass, carbon or aramide fibers.
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This application is a division of U.S. patent application Ser. No. 07/722,440, filed Jun. 27, 1991, U.S. Pat. No. 5,263,026, assigned to the same assignee as the present invention.
BACKGROUND
The present invention relates generally to digital cellular communications, and more particularly, to a maximum likelihood sequence estimation based equalization method for use in mobile digital cellular receivers.
Communication channels in the cellular environment commonly impose a combination of distorting effects on transmitted signals. Rayleigh fading, where a signal's perceived power level rises and falls rapidly over a wide range, results from the combination of signals that have traversed paths differing in length by at least a significant fraction of a wavelength (i.e., about 30 cm. for cellular). Differences in path transmission times that approach the time taken to transmit a symbol result in a second problem called delay spread.
Delay spread results in reception of multiple delayed replicas of a transmitted signal. Each Rayleigh faded replica has randomly distributed amplitude and phase, and the rate at which this complex quantity varies is constrained by the Doppler bandwidth associated with a vehicle's speed. In a frequency nonselective environment, the sampled outputs of a receiver's matched filter provides uncorrelated estimates of the transmitted data. As such, in terms of discrete time samples, the channel has exhibited an impulse response proportional to a delta function. With delay spread, on the other hand, the discrete time channel impulse response is extended to introduce energy at a number of symbol times. The effect of the channel on the transmitted signal, in turn, may be viewed as the convolution of the transmitted information with the channel's impulse response. The channel, therefore, emulates a convolutional coding process.
This leads to the possibility of estimating the transmitted information through the use of methods analogous to typical decoding of convolutional codes, i.e., maximum likelihood sequence estimation techniques. Unlike the more widely applied forward error correction decoding environment, the details of the encoding process in a reverse error correction decoding environment, are not known a priori by the receiver. Issues related to the need to estimate the form of the encoding process are addressed by this invention.
For the North American digital cellular system, a number of documents define the standards of implemented components. With respect to this invention, the following are of interest: "Dual-Mode Mobile Station--Base Station Compatibility Standard" denoted here as IS-54, [EIA/TIA Project Number 2398, Rev. A, January 1991] and "Recommended Minimum Performance Standards for 800 MHz Dual-Mode Mobile Stations", denoted here as IS-55, [EIA/TIA Project Number 2216, April 1991].
It would therefore be desirable to provide an enhancement to the processing performed by equalizers for use in mobile telephones that provides for system complexity reduction and that provides for better performance in a fading channel.
SUMMARY OF THE INVENTION
The present invention provides for an equalization method that forms the nucleus of a receiver for digital cellular mobile telephones. A number of distinct aspects of the design are considered novel, including: non-real time operation mode that permits and exploits "time-reversed" equalization, which significantly enhances bit error rate performance; the use of maximum likelihood sequence estimation; use of variable coefficient least mean square tracking during estimation of the transmission channel's impulse response; and integrated symbol timing adjustment and carrier tracking algorithms.
More particularly, the present invention comprises a method of processing received symbols including known preamble data and transmitted data, which method compensates for the effects of a power fade caused by a frequency selective fading channel. One specific aspect of the present invention comprises a method of processing samples received from a delay-spread, fading channel, which samples are associated with a block of data transmitted within a time slot, and wherein the method is adapted to make data decisions, and comprises the following steps: (1) Storing samples received during the time slot; (2) Estimating the location within the time slot at which decision errors are most probable, by determining the location in time of the maximum fade depth in the transmission channel impulse response; (3) Processing the stored samples, starting with the first received sample and proceeding beyond the location of the maximum fade depth, using a predetermined maximum likelihood sequence estimation procedure to generate estimates of the transmitted data; (4) Processing the stored samples, starting with the final received sample and proceeding in a reverse direction with respect to the time sequence in which the samples were stored, beyond the above-determined location, using the maximum likelihood sequence estimation process to generate estimates of the transmitted data; (5) Simultaneous with the above two processing steps, generating estimates of the characteristics of the transmission channel impulse response, which are used in the maximum likelihood sequence estimation process; (6) Processing the output of the preceding estimate generating steps to generate data decisions.
The step of generating the channel impulse response estimates typically comprises using variable tap coefficients that are determined by estimating tap settings within the estimated channel impulse response by minimizing the square of the difference between actual received samples and those synthesized by passing known transmitted signals through the estimated channel. The processing is done in an iterative manner by combining previous estimates of channel impulse response and new estimates thereof based on recent information, and by varying the ratio of the contributions from the previous and new estimates as a function of location within the time slot.
The method may further comprise a symbol timing adjustment procedure comprising the following steps: (1) Using a subset of the samples received during a time slot, generating an error measurement comprising a measure of the degree to which the estimated channel impulse response matches the actual channel impulse response; (2) Generating a plurality of similar measures utilizing simultaneously recorded samples having different time offsets wherein at least one sample is advanced and one sample is retarded in time relative to the above measure; (3) Searching for a bit time setting that minimizes the above error measurement and adjusting the sampling to reflect the newly determined bit time setting.
The method may also further comprise a carrier offset tracking method comprising the following steps: (1) Recording at least two samples of at least one tap within the estimated channel impulse response at selected symbol locations within the time slot during the equalization process; (2) Generating frequency offset estimates at each of a plurality of time slots by observing the phase difference in each time slot between the at least two samples; (3) Combining this plurality of frequency offset estimates by using a filtering process to generate a precise frequency offset estimate; (4) Adjusting a controllable frequency source to compensate for the precise frequency offset estimate.
Also, the present invention also uses a forward maximum likelihood estimation method of processing samples received from a delay-spread, fading channel, which is adapted to make data decisions. This method comprises the following steps: Storing samples received during the time slot; Processing the stored samples, starting with the first received sample and proceeding beyond the last received sample of the time slot using a predetermined maximum likelihood sequence estimation procedure to generate estimates of the transmitted data; Simultaneous with the above processing, generating estimates of the characteristics of the transmission channel impulse response which are used in the maximum likelihood sequence estimation process; Processing the outputs of the preceding steps to generate data decisions.
The maximum likelihood sequence estimation method offers significant performance advantages when compared with alternative equalization options, such as decision feedback equalization, for example. With respect to meeting industry defined standards for performance of digital cellular telephones used in fading environments, the performance of the equalizer incorporating the maximum likelihood sequence estimation process of the present invention stands out as superior. It is the only known process that is capable of meeting, or even approaching, the current digital cellular mobile telephone specifications. Time reversed operation further enhances performance and permits implementation with reasonable complexity of a standards compliant mobile receiver.
BRIEF DESCRIPTION OF THE DRAWINGS
The various features and advantages of the present invention may be more readily understood with reference to the following detailed description taken in conjunction with the accompanying drawings, wherein like reference numerals designate like structural elements, and in which:
FIG. 1 illustrates the problem associated with reception in a mobile environment with a fading channel and one aspect of the solution provided by the present invention;
FIG. 2 is a block diagram of a digital cellular mobile telephone receiver incorporating a maximum likelihood sequence estimation based equalizer in accordance with the principles of the present invention;
FIG. 3 shows the processing performed in the maximum likelihood sequence estimation based equalizer of FIG. 2;
FIG. 4 illustrates a graph of relative error versus bit timing offset that illustrates one problem overcome using the maximum likelihood sequence estimation based equalizer of the present invention;
FIG. 5 is a flow diagram illustrating the processing performed by the equalizer of the present invention to implement carrier frequency offset compensation; and
FIGS. 6A and 6B are flow diagrams illustrating the processing performed by the equalizer of the present invention to implement bit timing.
DETAILED DESCRIPTION
Referring to the drawing figures, FIG. 1 illustrates the problem associated with reception in a mobile environment having a fading channel and one aspect of the solution provided by the present invention. FIG. 1 shows a graph showing received power level from a typical fading channel versus time. The location of the power fade is shown relative to a typical time slot. The time slot is shown enlarged and includes a preamble and a coded digital verification color code field (CDVCC), which comprise known dam that is used to initialize a receiver system employing the equalizer of the present invention. At the lowest portion of FIG. 1, equalization processing in accordance with the present invention is illustrated with the arrows "A" and "B", in which the equalizer of the present invention processes forward and time reversed computations through the location of the power fade in order to accomplish the objectives of the present invention. This will be more fully described below with reference to FIGS. 2 and 3.
FIG. 2 is a block diagram of a digital cellular mobile telephone receiver system 20 incorporating a maximum likelihood sequence estimation based equalizer 21 in accordance with the principles of the present invention. The system 20 comprises an amplifier 22 whose output is coupled by way of a downconverter, comprising a frequency source 23 and a mixer 24, to an analog filter 25. An analog to digital converter 26 is coupled to the analog filter 25 in order to digitize the downconverted data. A matched filter 27 is coupled between the analog to digital converter 26 and the equalizer 21 of the present invention. The equalizer 21 comprises a memory 30, a 4-state equalization trellis 31 that is adapted to calculate maximum likelihood sequence estimation metrics, a channel impulse response estimator 32, and an equalizer control circuit 33.
A serially coupled AGC circuit 35 and gain control circuit 38 are coupled to the amplifier 22. The equalizer control circuit 33 is coupled to an output of the matched filters 27 and is coupled to an input to the frequency source 23. Symbol sampling (bit timing) time control circuitry 37 is coupled to the equalizer control circuit 33 and the acquisition circuit 36 and provides control signals to the analog to digital converter 26. The output of the matched filters 27 is coupled to the AGC circuit 35 and the acquisition circuit 36 and to the equalizer control circuit 33 that is employed to control the frequency source 23 and provide training data for use in initializing the equalizer 21.
In operation, a partially filtered IF signal with a center frequency of 85.05 MHz enters the gain controllable amplifier 22. The resulting signal is then downconverted using the frequency source 23 and the mixer 24 to 461.7 kHz. This signal is then filtered using a narrow analog filter 25 to reject most of the received signals outside the 30 kHz band of interest The resulting signal is then sampled and converted to 8-bit digital samples using the analog to digital (A/D) converter 26. A 16 tap fractionally spaced digital FIR filter 27 then performs matched filtering to produce symbol spaced samples which enter the equalizer 21. Temporally offset matched filters 34 that are substantially the same as the matched filters 27 are provided for use by the symbol timing control circuit 37, via the equalizer control circuit 33.
The principles of maximum likelihood sequence estimation employed in the equalizer 21 have been described in technical literature starting in the early 1970's. A useful outline is found in "Adaptive Maximum-Likelihood Receiver for Carrier-Modulated Data Transmission Systems", by G. Ungerboeck, IEEE Trans. on Communications, Vol. COM-22, pp. 624-636, May 1974. Another description of the maximum likelihood sequence estimation technique is provided in the reference "Digital Communications --2nd Edition.", by J. G. Proakis, 1989, pp. 610-642.
The maximum likelihood sequence estimation process is outlined as follows. The channel has an impulse response containing significant energy in, say, N symbols. Assume that the transmitter sends a sequence of symbols, much longer than N. The transmitted sequence may be described as the transitions between states, where each state corresponds to a group of N-1 transmitted symbols. The states, therefore, correspond to overlapping groups of transmitted symbols. In consecutive states, therefore, all but one constituent symbol are the same, and the possible transitions between states are correspondingly constrained. As each sample is received, the equalization trellis 31 considers every possible sequence of N symbols that could have contributed to its value, by convolving that sequence with the estimated channel impulse response. For each hypothesized sequence, the result of the convolution corresponds, or fails to correspond, in some way (defined by a statistic called a metric) to the measured sample. On an individual basis, the hypothesized sequence with the closest match to the measured sample (the best metric) is the most likely to have been transmitted. However, over many samples and under the constraint that only certain state transitions are possible, the path (sequence of states) with the minimum cumulative metric has maximum likelihood, and this is what the decoder selects.
The system 20 has no a priori knowledge of the form of the encoder employed in the transmitter. Performance of the equalizer 21 therefore depends on the accuracy of the estimate of the encoder's state, the channel impulse response (CIR). FIG. 2 also shows the signals used in estimating the channel impulse response. The objective is to estimate the form of the transversal finite impulse response filter that would take as its input the transmitted information symbols {a(n)}, and produce at its output the samples taken from the matched filter, {z(n)}. During the transmission of preambles and coded digital verification color codes, the receiver knows the values of {a(n)}. However, at other times, only the estimated values {a d (n)} are available for use in the channel impulse response estimation process. This dependence leads to a significant performance-degrading possibility. If decision errors emerge from the equalizer, and these are then used to update the estimate of the channel impulse response, then further decision errors become more probable leading in a circular fashion to further decision errors and breakdown of the equalization process. This phenomena is referred to as a "channel impulse response tracking breakdown". Such difficulties are most likely to arise at the periods of minimum signal-to-noise ratio, or when the received signal power is at its minimum during reception of a slot.
Within the IS-54 standard, which describes the interface between mobile and base equipment for North American digital cellular systems, each information time slot is preceded by a known sequence, designated as the "preamble". As viewed by the receiver, therefore, information in the time slot is bounded on both sides by known sequences; the preamble for this slot and the preamble for the subsequent slot. Consequently, this equalizer 21 is adapted to mitigate the effects of a channel impulse response tracking breakdown. By finding the most probable instant at which the problem might occur, equalizer operation approaches that instant from both forward and a time-reversed directions, both of which begin with known information sequences that are useful for training. Assuming that a channel impulse response tracking breakdown occurs, this approach minimizes the number of affected symbols by predicting the failure point and avoiding equalization beyond that point.
At 100 km/hr, which is the maximum speed specified in IS-55, which describes the mobile unit minimum performance requirements, the average time between fades are on the order of 12 milliseconds. Given time slot durations of about 6.7 milliseconds, there is only a small possibility of two significant fades occurring within a time slot. However, very close to the center of the slot is the coded digital verification color code field. Even after a channel impulse response tracking breakdown, the channel impulse response estimator 32 is very likely to recover during processing of the coded digital verification color codes due to the certainty of the transmitted data. Hence, the underlying period for which multiple fades are a concern is around 3.5 milliseconds. The chance of more than one deep fade occurring during this time is very low. Consequently, time-reversed equalization improves bit error rate performance in the digital cellular environment.
The present equalizer 21 uses a 4-state architecture, corresponding to N=2, where N is the length of the estimated channel impulse response. This choice assumes that the energy in two (symbol-spaced) samples of the channel's impulse response dominates. To avoid channel impulse response tracking breakdown problems, reverse equalization is used for those symbols following the minimum power point in a received time slot.
More specifically, FIG. 3 shows the processing performed in the maximum likelihood sequence estimation based equalizer 21 of FIG. 2. The first step involves finding the location of the power fade (box 51) in terms of symbol number. Processing starts in the forward direction toward the location of the power fade. The symbol number is set to 0 (box 52), and then incremented (box 53). A decision is made whether the symbol then processed is a training symbol (box 54). If the symbol encountered is a training symbol, then training data is inserted (box 57). If a training symbol is not processed, then the equalization trellis is employed to generate metrics and, if possible, a decision (box 55). This is accomplished using equations outlined below. Then it is determined if a decision has been made (box 56). If a decision has been made, then an estimate of the channel impulse response is generated (box 58). If the decision is not made, or once the channel impulse response estimate has been generated, then the symbol number is compared to the location of the power fade plus a predetermined number of additional symbols (box 59). Processing is then repeated by incrementing the symbol number (box 53) and repeating steps (boxes 54-59) until the fade location plus a predetermined number of additional symbols has been reached.
Once the desired symbol location is reached in (box 59), then processing is performed in the reverse direction starting with the preamble of the next succeeding time slot, namely symbol number 177, for example. The symbol number is set to 178 (box 62), and then decremented (box 63). A decision is made whether the symbol then processed is a training symbol (box 64). If the symbol encountered is a training symbol, then training data is inserted (box 67). If a training symbol is not processed, then the equalization trellis is employed to generate branch metrics and a decision (box 65). This is accomplished using the equations outlined below. Then it is determined if a decision has been made (box 66). If a decision has been made, then an estimate of the channel impulse response is generated (box 68). If the decision is not made, or once the channel impulse response estimate has been generated, then the symbol number is compared to the location of the power fade less a predetermined number of additional symbols (box 69). Processing is then repeated by decrementing the symbol number (box 63) and repeating steps (boxes 64-69) until the fade location less a predetermined number of additional symbols has been reached.
More particularly, and in operation, samples entering the equalizer 21 may be identified as z(n), and the output decisions may be identified as a(n). The probability of correctness of a(n) depends on location within the bursts. When a(n) is known with certainty the values of a(n), denoted a t (n), are used by the channel impulse response estimator 32 for training. At other times, the best estimate of a(n) is the output of the traceback decision process of the equalization trellis 31, denoted a d (n).
The equalization trellis 31 operates as follows. Equalization proceeds in the forward direction from the beginning of the preamble up until M symbols after the minimum power symbol. In the reverse direction, the same occurs with processing continuing M symbols beyond the minimum power point. This overlap ensures that trace-back through the trellis in all likelihood converges to a single path by the minimum power point.
Traceback for actual decisions does not occur until the completion of the equalization process. In addition to final traceback, however, there is a need for tentative decisions during equalization, to provide data estimates for the channel impulse response estimation to remain current. A trade-off in determining these tentative decisions arises (a) because the more up-to-date the information is, the more up-to-date the channel impulse response estimate can be (remembering that the channel is far from stationary at high speeds), and (b) the higher the number of symbols that are considered before tentative decisions are made, the more accurate the decisions will be; and hence, the lower the probability that errors are introduced into the channel impulse response estimation. In the case of 4-state equalization there is very little sensitivity to the number of constraint lengths of delay introduced.
Branch metrics are calculated in the equalizer 21 using the following equation: ##EQU1## where app -- state(l) represents a hypothetical state in combination with potential input data; a h (l,n) is a corresponding transmitted signal (constellation point), C represents the current estimate of the channel's impulse response, and z is the measured output of the matched filter 27.
The channel estimator 32 utilizes a second order least mean square algorithm to determine the coefficients of the transversal filter 27 that is an estimate of the channel ##EQU2## where C 0 (k) and C 1 (k) arc complex values of estimated channel impulse response taps, C S0 (k) and C n (k) arc complex intermediate values related to the estimated channel impulse response taps, permitting second order operation, K 1 and K 2 arc the real gain values controlling the tracking rate of the channel impulse response estimation process, z(k) arc complex symbol spaced sampled outputs of the receiver matched filter, and a(k) arc complex estimated or known values of transmitted symbols.
The values K 1 and K 2 within these equations control the rate of adaptation, and (conversely) the sensitivity to noise and decision errors. Consequently, to minimize the error rate, a trade-off between ability to track changes in the channel and degradation in performance due to imperfect input information is needed to optimize the values of K 1 and K 2 . The optimal values of K 1 and K 2 vary as a function of instantaneous signal to noise ratios, and thus as a function of depth of fade. Therefore, algorithms for modifying the values during each burst have been evaluated, with considerable improvement in performance relative to that achievable with constant settings.
One approach for modifying K 1 and K 2 has provided good performance and is as follows:
1. Set the values of K 1 and K 2 that will apply at the symbol determined to correspond to the deepest fade; K 1-- fade.
2. Adjust each value linearly (with preset slope--K1 -- slope and K2 -- slope) to reach the selected values at the fade location, using:
before forward processing--initialize
K 1 =K 1-- fade--K 1-- slope.fade -- location
K 2 =K 2-- fade--K 2-- slope.fade--location
before reverse processing--initialize
K 1 =K 1-- fade--K 1-- slope.(177--fade -- location)
K 2 =K 2-- fade--K 2-- slope.(177--fade -- location)
during processing--as each symbol is processed
K 1 =K 1 +K 1-- slope
K 2 =K 2 +K 2-- slope,
where K 1-- fade is the real value of K 1 at the symbol with the maximum estimated fade depth, K 2-- fade is the real value of K 2 at the symbol with the maximum estimated fade depth, K 1-- slope is the real increment in K 1 applied during processing of each symbol, K 2-- slope is the real increment in K 2 applied during processing of each symbol, and fade -- location is the symbol number at the maximum estimated fade depth, and last -- location is the symbol number of the final symbol.
Estimation of the location of the power fade entails use of the received symbols from the matched filter 27, and the settings on the AGC circuit 35 that were active during reception of those symbols. As the response of the amplifier 22 to the AGC circuit settings is effectively instantaneous, the primary delays in utilizing this information arise in the matched filter 27. This filter 27 is a linear phase filter (constant delay), so the available input information can be easily transformed into an accurate estimate of the envelope power. This envelope is averaged by a rectangular FIR filter over about ten (10) symbol times, with very good performance.
After completion of acquisition, the carder frequency offset should be less than 200 Hz. To operate without impairment, this offset should be on the order of 20 Hz or less. Thus, estimation of and correction for carrier offset must continue after acquisition. The method employed utilizes the fact that when frequency offset occurs, the taps of the channel impulse response will rotate consistently at a rate proportional to the offset. Changes in tap phases over fixed periods, therefore, provide an observable characteristic to apply to frequency control. Note that random phase changes occur in addition to these consistent rates of change, so filtering is used to extract the frequency offset. In practice, offsets of around 1000 Hz can be resolved although the maximum expected offset after acquisition is 200 Hz. The approach used is as follows:
1. During the reception of each burst, the haft of that burst that does not include the deepest fade is selected for tracking. This scheme is aimed at avoidance of the very high rates of change in phase that typically accompany transitions through low signal amplitudes.
2. Two samples of each of the two estimated channel impulse response taps are recorded: just after the preamble (or leading into the postamble if the fade occurred during the first half of the slot), and 20 symbols later (or 20 symbols earlier). At a symbol rate of 24300 symbols per second, a 100 Hz offset would result in an average rotation of 29.6 degrees during the 20 symbol period. For any rotation in excess of 180 degrees, the observed rotation would be less than 180 degrees but in the opposite direction. This aliasing could impact performance for frequency offsets above about 300 Hz. In typical operation, however, the detriment to performance resulting from such aliasing has proved minimal, due to the anti-aliasing filtering inherent in the tracking. The selection of a sampling window of 20 symbols was based on concern about this aliasing. Otherwise, a longer window would improve noise immunity.
3. From information determined during the bit timing fine tuning, the dominant tap is selected. Using the recorded settings for this tap, a phase change is calculated, yielding an estimate of the frequency offset.
4. These estimates are then filtered over many bursts to reduce the "noise" that arises primarily due to the random (zero mean) presence of Doppler offsets and Gaussian noise. The filter output provides an estimate of the carrier offset and can be used to directly update the frequency control hardware. The offset is given by:
f -- offset -- estimate k+1 =(1-K fo )f -- offset -- estimate k +K fo freq -- observed,
where freq -- observed is derived from the observed phase change, the constant K fo controls the convergence rate of the estimation process, f -- offset -- estimate k is the estimated frequency offset at frame "k", and K fo is a constant controlling the convergence rate of the frequency tracking. If f -- offset -- estimate reaches half the resolution of the frequency source, then a step in frequency is applied, e.g., if the resolution is 20 Hz and f -- offset -- estimate exceeds 10 Hz, then a 20 Hz change in reference is applied. At the same time f -- offset -- estimate is reinitialized.
Referring to FIG. 5, it illustrates a flow diagram showing the processing performed by the equalizer 20 to implement carrier frequency offset compensation. Utilizing an already located fade, a decision (box 100) is made as to whether to use the first or second half of the received slot for frequency offset estimation. Based on this decision, samples are taken twenty symbols apart in the appropriate half of the slot (boxes 101,102). For the selected case, individual taps are compared and the larger is chosen (decisions 103, 104). The phases of the chosen tap at the selected two times are then subtracted (boxes 105-108) to produce "freq -- observed", a noisy estimate of the offset. This is filtered (box 109) to generate an accurate estimate of the offset If an adjustment in setting of the frequency control would reduce this offset, then a decision is made to do so (decision 110); and the decision is then implemented (box 111).
The equalizer is reasonably insensitive to errors in bit timing. However, for the following reasons, symbol timing adjustments continue during equalizer operation. The initial estimate produced by acquisition may differ sufficiently from optimal timing so that performance would benefit from adjustment. The transmit and receive symbol timing clocks may differ by about 5 ppm, resulting in drift of about 0.1 μS per frame (or a symbol every 8 seconds). This drift must be compensated for. In practice, individual independently-delayed signal paths will randomly rise and diminish in average strength, resulting in situations that would be best catered for by different symbol timing. Optimal symbol timing depends on an ability to track these changing situations.
The operation of the symbol timing control is as follows. The approach has similarities to the early-late gating schemes frequently employed in direct-sequence spread spectrum receivers. As each burst is received, a measure of the error between the expected preamble and the actual received preamble is generated. In addition, in alternating frames, similar measures are made on time advanced and retarded versions of the same input samples. If no timing adjustment is necessary, the error generated with the existing timing should be less (on average) than either of the others. Adjustments are made when this is not the case or there is a consistent disparity between the advanced and retarded error estimates. This process is simply a search for bit timing that minimizes the error statistic, as illustrated in FIG. 4. The control loop used includes an estimator of any consistent change in timing, corresponding to drift with respect to the transmitter. Drift in the order of 10 ppm can be compensated for by this loop.
This search for a minimum may be hampered by the possible presence of a local (non-global) minimum. In fact, for this statistic the presence of two minima is common (corresponding to the two taps implicit in the equalizer structure--see FIG. 1). The approach taken to resolve this conflict is as follows. The more advanced minimum is presumed to be the preferred sampling time. Multiple minima typically arise when there is a small level of delay spread, i.e., less than about 10 μS. Under such conditions the ratio of magnitudes of the estimated paths in the (symbol-spaced) channel impulse response differs significantly in the region of the more advanced minimum from that in the more retarded case. Thus, the ratio of tap magnitudes provides a statistic from which to conclude the appropriateness of a selected minimum.
With reference to FIGS. 6A and 6B they show flow diagrams illustrating the processing performed by the equalizer 20 to implement bit timing control. Inputs (box 80) include the on-time and time-offset samples (z (n) and z offset(n)), and a flag to indicate the direction of the time offset. The on-time samples are fed into the equalizer 20 just as they are during normal training 83. Similarly, the time offset samples are fed to the equalizer 20 (box 84). In both cases, the branch metrics (on the known correct paths) are accumulated over the latter symbols to provide measures (ERROR cum and ERROR OFFSET cum ) of the degree to which the samples match expectations.
In a separate process the magnitudes of each of two taps estimated as the channel impulse response at the end of the training process are calculated (box 85). Averaging the ratio of these taps over a number of frames (boxes 86-89) permits a judgement to be made as to whether the bit timing has selected an inappropriate local minimum. If a threshold (box 90) is reached, then bit timing will be advanced by a full symbol time (box 91). Taking account of the relative time at which samples were taken (box 92), the ERROR cum and ERROR OFFSET cum measures are combined to generate a noisy estimate of an appropriate timing adjustment (boxes 93, 94). This estimate is then filtered (box 95) to generate an actual timing offset adjustment. To compensate for consistent drift, an additional term "drift -- est" monitors and compensates for this effect.
Thus there has been described a maximum likelihood sequence estimation based equalization method for use in mobile digital cellular receivers. It is to be understood that the above-described embodiments are merely illustrative of some of the many specific embodiments which represent applications of the principles of the present invention. Clearly, numerous and other arrangements can be readily devised by those skilled in the art without departing from the scope of the invention.
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The present invention provides for sample timing adjustment using channel impulse response which is particularly well adapted for use in a receiver for digital cellular mobile telephones. The sample timing adjustment includes storing samples in time slots, generating estimates of the transmission channel impulse response, and using a subset of the samples received during the time slot, and generating error measurements of the degree to which the estimated channel impulse responses match the actual channel impulse responses. The different measures use simultaneously recorded samples having different time offsets. At least one sample used for each measure is advanced in time and one sample used for each measure is retarded in time relative to the samples used for generating the first measure. Then, a sample time setting that minimizes the error measurement is determined and the sampling is adjusted to reflect the newly determined sample time setting. Time-reversed operation further enhances performance and permits implementation with reasonable complexity for a standards compliant mobile receiver.
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BACKGROUND OF THE INVENTION
The present invention relates generally to the field of mascara brushes, and in particular to mascara brushes having more than one type of bristle.
The typical mascara brush of the prior art comprises a multiplicity of bristles mounted to a helically twisted wire, such that the free ends of the bristles are disposed in a spiral configuration. The shape of the brush is generally cylindrical, having bristles of uniform length throughout the length of the brush, or conical, having progressively shorter bristles toward the brush tip. Bristle density varies, sometimes according to bristle diameter, but is generally known to be in the range of 10 to 60 bristles per turn. The twisted wire axis is usually supplied with a handle at the end opposite the bristles. This handle also typically serves as the cap for the mascara container which houses the brush when it is not in use and carries the mascara supply.
The conventional mascara brush employs relatively soft bristles of nylon composition. These bristles are typically cylindrical in shape and have a circular cross-section, although other shapes are taught in the art. The suppleness of the bristle material is essential for the purpose of picking up the mascara from the container and transporting it to the eyelashes. However, this type of bristle often results in clumping during application, because, while the bristles are soft enough to properly transport the mascara, they are too soft to provide the combing effect necessary to achieve uniform distribution of mascara to the eyelashes. As a result, a separate instrument has been required to comb the lashes during application with the conventional brush.
It has been suggested by the prior art to use two different types of bristles in the same brush, i.e., soft bristles for applying the mascara and stiff bristles for combing the applied mascara through the lashes. For example, U.S. Pat. No. 4,964,429 to Cole discloses a mascara applicator with alternating rows of flexible bristles and stiff teeth. U.S. Pat. No. 4,861,179 to Schrepf discloses a spiral mascara brush having soft and stiff bristles randomly intermingled throughout the length of the brush in specific proportion. However, the spiral configuration of these brushes does not allow for a uniform distribution of the bristle tips, which has been found to be better for the purpose of picking up and transferring mascara, especially mascaras of high viscosity.
U.S. Pat. Nos. 4,733,425 and 5,161,554 disclose the use of certain bristle types which, when used with the conventional twisted wire axis, result in a non-spiral bristle configuration. U.S. Pat. No. 4,733,425, for example, discloses the use of hollow bristle fibers which compress when gripped between the wire axis and flare outwardly in a random arrangement. Similarly, U.S. Pat. No. 5,161,554 discloses the use of bristles with varying diameter along the longitudinal axis of the bristle such that they produce a random configuration depending on where they are engaged with the wire axis. However, these patents do not solve the previously addressed problem of clumping without the use of a separate combing implement.
Another proposed solution is disclosed in U.S. Pat. No. 4,887,622 wherein a lesser bristle density is used in combination with a larger diameter and thus stiffer bristle in an attempt to provide a brush which will both evenly apply the mascara and separate the lashes.
Thus, there is a need for an improved mascara brush which allows for optimal transfer of a high viscosity mascara product to the lashes in a single stroke application, by providing maximum exposure of brush to the eyelashes and incorporating a combing implement to eliminate clumping.
SUMMARY OF THE INVENTION
It is an object of the present invention to provide a mascara brush which is capable of both applying mascara and combing the eyelashes so as to provide a uniform distribution of mascara to the eyelashes.
It is another object of the invention to provide a mascara brush which maximizes the exposure of the lash to the mascara thereby providing for single stroke application.
It is a further object of the invention to provide a mascara brush which may be effectively utilized with high viscosity mascara formulations.
It is a still further object of the invention to provide a mascara brush capable of effectively reaching the corners and roots of eyelashes for optimal application of product.
The present invention contemplates an improved mascara brush having three sections or zones of bristle configuration along the length of the brush portion. The middle cylindrical section is comprised of a combination of stiff and supple bristles intermingled in random arrangement, and the end portions are comprised of a third type of bristle.
The diameter of the middle portion of the brush is preferably 0.325 inches or greater, larger than that of the standard mascara brush. The bristles of the middle section are preferably comprised of a combination of stiff, irregularly-shaped synthetic "goat" fibers of about 0.004 to 0.006 inches and soft ultrafine fibers of about 0.001 to 0.002 inches in diameter. These fibers are inserted between the legs of a wire axis which has been twisted in a helical formation and inserted into a rod which extends from the cap of the mascara container. By virtue of their irregular shape, the stiff bristles are held by the wire in random configuration and are distributed throughout the middle section of the brush in a non-spiral arrangement.
The bristles contained in the end portions of the brush are preferably comprised of hollow synthetic fibers of about 0.004 to 0.006 inches in diameter, most preferably of about 0.005 inches. These fibers are gripped between the wire core in the standard fashion, such that the bristles extend out from the wire in a spiral, or helical, configuration. Preferably, one or both of the end sections are tapered such that the bristle length progressively decreases nearer the tip and/or base of the brush. The bristle density of these end sections is significantly less than that of the middle section of the brush.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a longitudinal side view of a mascara brush according to the present invention;
FIG. 2 is an enlarged cross-sectional view of a non-circular bristle as utilized in the middle section of a mascara brush according to the present invention;
FIG. 3 is an enlarged cross-sectional view of a circular ultrafine bristle as utilized in the middle section of a mascara brush according to the present invention;
FIG. 4 is an enlarged cross-sectional view of a hollow bristle as utilized in the tapered end section of a mascara brush according to the present invention; and
FIG. 5 is a longitudinal side view of a second embodiment of a mascara brush according to the present invention.
DETAILED DESCRIPTION OF THE INVENTION
A mascara brush according to the present invention is shown in FIG. 1. The brush portion 10 is comprised of a plurality of bristles arranged in three distinct sections or zones 12,14,16 throughout the length of the brush--a middle section 14 and two end sections 12,16. The sections are distinguished by the diameter and stiffness of the bristles found in each section.
The bristles of all three sections of the brush are mounted to a metal wire 24 which is bent at its midpoint, forming the brush tip 26, and twisted about itself in a helical configuration as is known in the art. The pitch of the metal helix is preferably about 15.0 to 19.0 turns per inch. The wire 24 of the core has a diameter of about 0.0270 to 0.0290 inches. The bristles are gripped at their midpoints between the twisted wire and extend outwardly from the helical axis 24. Opposite the brush tip 26, the wire axis extends longitudinally beyond the last bristle at the base 27 of the brush portion 10 and is fixedly housed in a hollow rod 28 projecting from a cylinder 30, which may function as the cap of the mascara container.
The middle section 14 of the brush 10 is generally cylindrical in shape due to the fact that the bristles 22 of this section are of relatively uniform length. The diameter of the middle section 14 of the brush portion is preferably about 0.325 inches or greater, most preferably about 0.350 inches. This diameter is significantly greater than that of the standard mascara brush, so as to facilitate use with high viscosity mascara formulations and provide maximum exposure of the brush to the lashes. Longer bristles, such as the ones used in the present invention, were formerly believed to be too flexible to provide the stiffness and control required for mascara application. However, as is further shown below, the tri-sectional configuration and combination of bristle types utilized by the present invention allows for the use of such longer bristles while maintaining the stiffness required for optimal mascara application.
The bristles 22,23 utilized in the middle cylindrical section 14 of the brush are of two types: preferably, a soft bristle 23 for applying the mascara and a stiff bristle 22 for combing the mascara through the lashes. For purposes of this application, "soft" bristles are defined as those bristles which have relatively low flexural strength, i.e., resistance to bending, whereas "stiff" bristles have substantially greater flexural strength. Bristle stiffness varies depending on the bristle material, the diameter of the bristle and the bristle length. Thus, all other things being equal, a shorter bristle is more stiff than a longer bristle and a thicker bristle is stiffer than a thin bristle. Additionally, hollow bristles are generally more flexible than solid bristles of the same material and dimensions. As used herein, solid synthetic bristles having a diameter less than 0.004 inches are considered "soft" whereas solid synthetic bristles of 0.004 inches or greater diameter are considered "stiff."
As shown in FIG. 2, the soft bristles are preferably of generally circular cross-section and may be formed of various synthetic fibers, such as polyamide, polyesters, polyolefin and the like. The diameter of the soft bristle fiber is preferably about 0.001 to 0.002 inches to provide the requisite suppleness for applying the mascara. As shown in FIG. 3, the stiff bristles are preferably of irregular or non-circular cross section, similar to that of natural goat hairs. These fibers may be formed synthetically from any of the known materials listed above. The preferred bristle has a diameter of about 0.004 to 0.006 inches, most preferably about 0.005 inches.
The combination of stiff bristles 22 and soft bristles 23 comprising the middle section 14 of the brush are fed together in random arrangement through the legs of the twisted wire axis 24 and gripped at their midpoints therein. The bristles 22,23 of the middle section 14 are more densely packed than the bristles 18,20 of the end sections 12,16. Preferably, the density of the stiff bristles 22 is about thirteen to twenty-four bristles per turn, and the bristle density of the soft bristles 23 is about ten to eighteen per turn. In the preferred embodiment, the non-circular stiff bristles 22 are held in random engagement with the wire axis 24 by virtue of their irregular shape. This irregular engagement causes the bristle fibers 22 to project outwardly in random formation, thereby producing a fuller, more uniform bristle distribution throughout the middle section 14 of the brush.
The end sections 12,16 of the brush 10 are comprised of a plurality of stiff bristles 18,20 preferably of a different bristle type than the stiff bristles 22 used in the middle cylindrical section 14 of the brush. For example, as shown in FIG. 4, the bristles 18,20 utilized in the preferred embodiment are tubular fibers of hollow circular cross-section. These bristles 18,20 are known to be manufactured of various synthetic materials, such as polyamide, polyesters, and polyolefins, and are available in varying diameters. The preferred embodiment utilizes a hollow nylon fiber of about 0.004 to 0.006 inches in outer diameter, most preferably about 0.005 inches.
The fibers 18,20 utilized in the end sections 12,16 of the brush are gripped between the legs of the wire axis 24 at their midpoints. It is known that hollow fibers have a tendency to flare outwardly in a substantially V-shaped arrangement, thereby producing a random distribution of bristles at the face of the brush. However, it is preferred in the present invention that the end sections 12,16 of the brush maintain a spiral arrangement. Therefore, when using hollow bristles in the end sections 12,16 of the brush, the bristle density must be adjusted to assure a substantially spiral arrangement in these end sections, while remaining less densely packed than the middle section 14 of bristles. For example, the preferred embodiment incorporates a bristle density of about twenty-seven bristles per turn in the end sections 12,16 of the brush.
As shown in FIG. 5, one or both of the end sections 12,16 of the brush are preferably designed to have a sharp taper such that the bristles 18 at either end of the brush are progressively shorter than those bristles 20 immediately adjacent to the middle section 14 of the brush portion 10. Unlike brushes which utilize an elliptical or football shape, the sharp taper of this preferred embodiment clearly distinguishes the end sections 12,16 of the brush from the middle section 14 of the brush. This sharp taper has several advantages. For example, the tip end section 16 is useful as a styling tool for reaching into corners and combing through the delicate lashes of the lower eyelid. On the other hand, the short, stiff bristles of the base end section 12 serve to keep the middle section 14 of the brush cleaner upon removal from a mascara container by dispensing of any excess mascara accumulated at the opening of the container before it reaches the longer, more flexible bristles 22,23 of the middle section 14.
Therefore, while there have been described what are at present considered to be the preferred embodiments of this invention, it will be obvious to those skilled in the art that various changes and modifications may be made without departing from the invention, and it is, therefore, aimed to cover all such changes and modifications that fall within the true spirit and scope of the invention.
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A mascara brush having three sections and three types of bristles is disclosed. The brush portion has a larger diameter middle section comprised of a combination of soft and stiff bristles in random configuration, and two end sections comprised of hollow filaments which preferably become progressively shorter towards the ends of the brush portion. The end sections exhibit less bristle density than the middle section. This improved brush configuration allows for optimal one-stroke mascara application.
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BACKGROUND OF THE INVENTION
[0001] The invention relates to accessories for edge trimming pan-shaped downwardly accessible suspended ceiling panels.
PRIOR ART
[0002] A category of ceiling panels are of a type hung below a suspended grid. Panels of this style are typically attached to the grid with torsion springs carried on the panels. The torsion springs draw the panels up against a lower face of the grid elements. This type of panel allows for downward accessibility into the plenum above the ceiling and can be arranged to conceal the grid and provide a monolithic appearance for the ceiling.
[0003] There exists a need for componentry for trimming or finishing the edges of the described panels where the edges are exposed such as where the ceiling is interrupted for lighting or other utilities.
SUMMARY OF THE INVENTION
[0004] The invention provides a trim strip having a unique configuration enabling it to be attached to a grid member and to conceal both the grid member and an edge of an adjacent pan-shaped underhung ceiling panel. The trim strip is proportioned to match the depth of the ceiling panels so that it is visually integrated with the ceiling panels. The disclosed trim strip is arranged to receive a unique splice plate that can be conveniently used for both miter joints and butt joints. The splice plate is received in a track on the inside face of the trim strip. Locking tabs on the splice plate are deployed, typically without tools, to tightly lock the splice plate to joined ends of two lengths of the trim strip. The locking elements of the splice plate are arranged to bear against areas remote from the material directly behind the strip faces so that the risk of distorting a face with a locking force is eliminated.
BRIEF DESCRIPTION OF THE DRAWINGS
[0005] FIG. 1 is a fragmentary perspective view of a corner of a perimeter frame embodying the invention for a light fixture or other utility opening in a suspended ceiling constructed of a trim strip of the invention;
[0006] FIG. 2 is a side perspective view of a butt joint between two spliced trim strip lengths embodying the invention;
[0007] FIG. 3 is an end view of one form of the trim strip of the invention installed on a grid member and visually finishing the edge of a pan-shaped ceiling panel shown in phantom;
[0008] FIG. 4 is an end view of another form of the trim strip of the invention installed on a grid member and visually finishing the edge of a pan-shaped ceiling panel shown in phantom;
[0009] FIG. 5 is a perspective view of a trim strip splice plate of the invention;
[0010] FIG. 6 is a plan view of the splice plate;
[0011] FIG. 7 is a side view of the splice plate;
[0012] FIG. 8 is an end view of the splice plate; and
[0013] FIG. 9 is a sectional view of a lever tab of the splice plate taken in the plane 9 - 9 indicated in FIG. 7 .
DESCRIPTION OF THE PREFERRED EMBODIMENT
[0014] FIG. 1 illustrates an outer view of an “inside” miter joint 10 of two lengths of the inventive trim strip 11 . The broken lines illustrated in FIG. 1 show a rectangular form fabricated of four lengths of the trim strip 11 in a rectangular frame 12 . The illustrated frame 12 has the rectangular shape of a square that has nominal 2 foot by 2 foot dimensions of a conventional suspended ceiling grid module. The frame 12 can be assembled in other standard nominal rectangular sizes such as 2 foot by 4 foot. Dimensions used herein may be replaced by industry metric equivalents.
[0015] Different versions of a trim strip 11 and 13 are disclosed. Herein, the term “trim strip” relates to both versions 11 and 13 unless the context indicates otherwise.
[0016] The trim strip is preferably formed as an elongated unitary or one piece aluminum extrusion and may be painted or powder coated with a white or other desired color on its visible surfaces. The trim strip has the general shape of a channel with upper and lower horizontal flanges 16 , 17 , respectively, jointed by a vertical web 18 . An extension 19 of the web 18 extends somewhat above the upper flange 16 . Each trim strip 11 , 13 is nominally 1⅝ inch tall. A top surface 21 of the horizontal flange 16 is 1½ inch above a lower surface 22 of the lower horizontal flange 17 . The trim strip 13 of FIG. 4 has a horizontal extension 26 of the lower horizontal flange 17 on the side of the web 18 opposite the side on which the main part of the flange exists.
[0017] The lower flange 17 has a vertical lip 27 at its distal edge. The trim strip includes a pair of mutually facing angles 28 , 29 integral with the web 18 . The angles 28 , 29 include a horizontal leg 31 , 32 and a distal vertical leg 33 , 34 . The vertical spacing between the horizontal legs 31 , 32 and the spacing of the vertical legs 33 , 34 from the web 18 is maintained with sufficient accuracy such that collectively they form a track 36 in which is received a splice plate, discussed below, with a close sliding fit. Preferably, the elements of the trim strip have a uniform wall thickness except for the upper flange 16 which is made thinner to facilitate reception of a self-drilling screw as discussed below.
[0018] FIGS. 3 and 4 illustrate a typical mounting of a trim strip 11 , 12 on a grid member 38 . The image of the grid member 38 represents a standard grid tee or grid runner typically in the form of a main runner and special cross runners having slotted lower flanges for reception of torsion springs as is known in the industry and illustrated, for example, in U.S. Pat. No. 9,228,347. A trim strip is mounted on a grid member 38 by abutting the upper surface 21 of the upper flange 16 against the lower face of a flange 39 of the grid runner 38 and the upper extension 19 of the web 18 against a distal edge of the grid member flange 39 . A series of short self-drilling screws (only one is shown in FIGS. 3 and 4 ) spaced along the length of the trim strip are driven downwardly through the grid member flange 39 and the trim strip upper flange 16 to fix the trim strip to the grid runner 38 .
[0019] A principle use of the trim strip is to finish the edge of a pan-shaped metal ceiling panel 46 , shown in phantom in FIGS. 3 and 4 , where the panel edge would be otherwise exposed. This situation will occur, for example, where an adjoining panel is omitted to leave an opening for a light fixture or other utility such as an air supply or return vent or an audio speaker.
[0020] It will be understood, as suggested in FIGS. 3 and 4 , the trim strip 11 or 13 will occupy one-half the width of the grid runner flange 39 while the periphery of a ceiling panel will occupy the other half. Note that the trim strips are proportioned so that when installed, their lower faces 22 are coplanar with a main face 47 of the adjacent ceiling panel 46 .
[0021] Where a full module space in a suspension grid is devoted to a light fixture or other utility device, the trim strip 11 or 13 is fabricated into a rectangular frame dimensioned so that the upper part or extension 23 of the web of each trim strip side fits closely with the grid flanges 39 at the inner periphery of the module. To accomplish this, the lengths of the trim strip are cut at 45 degrees to produce miter joints such as shown in FIG. 1 . Upper flanges 16 of the assembled lengths of the trim strip are raised up against the lower surface of the flanges 39 of the grid members 38 defining the module. The rectangular frame 12 is then fixed in place preferably with self-tapping screws 41 down through the grid flanges 39 into the upper flanges 16 or with equivalent fastening elements.
[0022] FIGS. 5-9 illustrate a metal splice plate 50 preferably formed as a one-piece sheet steel stamping of, for example, 0.047 inch hot dipped galvanized stock. The illustrated splice plate 50 is an elongated element having a flat rectangular mid-section 51 and inclined lever tabs 52 at each end. The mid-section 51 is weakened across two transverse lines by edge notches 53 and a hole 54 to form potential hinge lines for bending the splice plate 50 into a 90 degree angle. The splice plate 50 is embossed across land areas 55 between the notches 53 and hole 54 in the direction the lever tabs 52 are displaced before being deployed. A weakened hinge line is similarly provided at the juncture between the mid-section 51 and each lever tab 52 by edge notches 56 and a central slot 57 . The lever tabs include laterally outlying grips 58 adjacent the mid-section 51 . Lower edges 59 of the grips at the edge notches 53 are maintained relatively sharp during the stamping process to facilitate their “bite” onto a trim strip as discussed below. To augment the biting or gripping action of the tab edges 59 , the grips 58 are stamped slightly downwardly out of the plane of the lever tab proper as shown in FIG. 9 .
[0023] The splice plate 50 is used to make miter and butt joints between lengths of the trim strips 11 , 13 . FIG. 1 illustrates the splice plate 50 holding joined lengths of trim strip abutted in an “inside” corner construction. Use of the term “inside” is in a traditional sense where the visible sides of the webs 18 are facing generally towards one another. The thickness and width of the plate mid-section 51 is proportioned to provide a close sliding fit within the track 36 established by the angles 28 , 29 . With the splice plate 50 bent into a right angle at one of the lines of the edge notches 53 and hole 54 , each end of the mid-section 51 is inserted in a respective track 36 of one of the two lengths of trim strip to be joined at a corner. Initially, the lower edges 59 of the lever tab notches 56 are displaced from the plane of the top of the mid-section 51 a distance greater than the wall thickness of the vertical legs 33 , 34 of the trim strip track 36 . This spacing of the edges 59 allows the lever tab grips 58 to pass freely along outer surfaces of the vertical legs 33 , 34 . The initial orientation of the lever tabs 52 is shown in FIGS. 5 and 7 .
[0024] The lever tabs 52 are deployed to lock the splice plate 50 and an associated trim strip length. As a lever tab 52 is depressed towards the web 18 of the respective trim strip length, the sharp edges 59 of the grips 58 bite into and lock onto respective track legs 33 , the material of a trim strip preferably being softer than that of the splice plate 50 . The material of the splice plate 50 is sufficiently malleable that a lever tab 52 does not appreciably spring back towards its original incline position.
[0025] The embossed area 55 where the splice plate 50 is hinged, avoids an interference of this hinge area with the ends of the trim strips at their webs 18 at a frame corner. With four splice plates 50 installed at the four corners, the frame 12 is a rigid assembly.
[0026] The trim strips 11 or 13 can be used to form the edges of several adjacent ceiling panels such as in narrow utility channel systems. More than one full length of trim strip may be needed to span the collective length of the panel edges. In such a case, two trim strips can be spliced by the disclosed splice plate 50 . In this situation, shown in FIG. 2 , the splice plate mid-section remains flat and is centered over the abutted ends of the lengths of trim strips. The splice plate 50 is locked in place on the two ends of the trim strips in the same manner as described in connection with the miter joint shown in FIG. 1 . Specifically, the lever tabs 52 are pressed towards respective trim strip webs 18 to cause the edges 59 to lock on the track angle legs 33 .
[0027] It will be appreciated that the locking forces developed by the lever tab grips 58 is supplied to parts of the trim strip that are remote from the exposed or finished face of the trim strip so that there is no risk that this locking force will cause a visible distortion in the visible face.
[0028] The version of the trim strip 13 shown in FIG. 4 is useful where it is desired that a ceiling opening such as for a light or air duct have a semi-flush membrane of, for example, transparent or translucent material, or a grill. In such a case, the membrane 61 can be installed on top of the horizontal extension 26 . In a square opening, the horizontal extension 26 will extend on four sides of the opening. In a narrow utility channel, the horizontal extension can be arranged on both sides of the channel to support opposite edges of the membrane 61 .
[0029] It should be evident that this disclosure is by way of example and that various changes may be made by adding, modifying or eliminating details without departing from the fair scope of the teaching contained in this disclosure. The invention is therefore not limited to particular details of this disclosure except to the extent that the following claims are necessarily so limited.
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In combination, extruded aluminum trim strips joined end-to-end and a splice plate, the trim strips together, the trim strip cross-sections including a web and a pair of opposed angles, the angles and web forming a track for receiving a mid-section of the splice plate with a close sliding fit, the splice plate having lever tabs at opposite ends, notches at sides of the plate, the plate being disposed in the tracks of both lengths of trim strips, the lever tabs and associated edges of the lever tabs formed by the notches being outside of the tracks, the associated edge being arranged in a locking manner with outer surfaces of the angles as a result of the lever tabs being bent in place towards the web.
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BACKGROUND OF THE INVENTION
The present invention relates to a device discharging or exhausting heated air generated by an electromotor or motors (hereinafter simply referred to as a motor), powered with a battery or batteries, for use in a forklift truck.
More particularly it relates to a device speedily discharging heated air, generated or produced by a motor placed in an almost completely covered space, by utilizing a cooling fan which is provided with in the motor and avails itself as a ventilator of the covered or closed space.
A battery-powered forklift truck is generally provided with a pair of motors, one is for propelling the main body of the forklift truck (hereinafter simply referred to as a body) and the other is for driving the hydraulic pump, both of which motors are strictly limited with respect to the space available for the location thereof. The motors are (hereinafter a singular form instead of plural form will be used for the convenience sake) often required to be placed in a relatively closed and poorly-ventilated place; it is not necessarily possible to place the motor in a well-ventilated open space. When the motor is placed on the upper portion of the body, as is sometimes observed, it is usually obliged to be hooded or covered for the sake of good appearance. Moreover the motor is sometimes subject to be placed together with heat-sensitive parts, which preferably should be placed in a cool place.
An electric motor is generally a heat-generating apparatus, to a certain extent, so it is often provided with a cooling fan to keep it cool or an exhaust fan to discharge heated air therefrom. When the motor is disposed in a closed space, consequently, the heated air emitted from the motor will be accumulated in the space not only to affect heat-sensitive regulating apparatus or the like placed in the same space but also to overheat the motor itself. This is the reason why openings for ventilation have been conventionally provided to otherwise closed space within which a motor for a forklift is positioned.
It can hardly be expected that a forklift truck is naturally ventilated by wind or moving air, as the traveling speed thereof is normally low and a forklift truck is frequently subject to indoor operation; only natural draught or convectional ventilation can be expected at the best. While a motor for the hydraulic pump is working this tendency is particularly noticeable, because the forklift truck is in a stationary state in such a situation. In conventional battery-powered forklifts undesirable effects from heat from the motor and/or overheating of the motor itself actually frequently occur.
SUMMARY OF THE INVENTION
It is an object of the present invention to provide a solution of the abovementioned problems.
The foregoing object of this invention is achieved by a device, for use in a battery-powered forklift, discharging heated air emitted from a motor out from a closed space, wherein the motor is placed, into the atmosphere, by providing an air exhaust duct of simple structure around an air exhaust fan of the motor and making an opening on a wall covering or defining the closed space, which opening is confronting to the air exhaust duct, in order to get a good cooling effect for the motor as well as the closed space.
DESCRIPTION OF THE DRAWINGS
FIG. 1 is a vertical sectional-view of a conventionally constructed closed-space for accommodating a motor;
FIG. 2 is an elevational view of an embodiment of this invention with a part thereof being broken away;
FIG. 3 is a sectional view taken along the line III -- III of FIG. 2;
FIG. 4 is a sectional view taken along the line IV -- IV of FIG. 2; and
FIG. 5 is an exploded perspective view of the device shown in FIG. 2.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Before turning to the illustrated embodiment shown in FIGS. 2 to 5, a brief reference is made to the conventionally constructed forklift truck motor arrangement of FIG. 1. As shown in FIG. 1, an electric motor 2 of a forklift truck is positioned in a substantially closed space 7 defined by a frame 3 of a forklift truck and a hood or cover 4. The cover 4 is provided with openings 4a and the frame 3 is provided with at least one opening 3a for ventilation purposes. With reference FIGS. 2 to 5 a preferred embodiment of this invention is described with respect to the structure and function thereof.
Structure:
The reference numeral 1 denotes an exhaust duct which is composed of an air collector body or a hood 1a and an air exhaust passage 1b. The exhaust duct 1 as best seen in FIG. 5 can be disassembled into two at approximately the middle thereof by simply unscrewing two nuts from respective bolts. The motor 2 is provided with an exhaust fan 2a which discharges the air sucked in suction openings 2b out of an air discharging openings 2c, both inlet and outlet openings being disposed on the outer shell of the electric motor 2, longitudinally apart with each other, as seen in FIG. 5. The reference numeral 3 denotes a fame of the fork lift truck body, the numeral 4 a cover fixed on the frame 3; both the frame 3 and the cover 4, as walls, define or form a closed space 7 wherein the motor 2 is installed. The motor 2 is secured to the frame 3 by means of mounting seats 6; the exhaust duct 1 is so disposed as to perfectly cover the air discharging openings 2c. An air exhaust opening 1c provided at the end of the air exhaust passage 1b is adjacently confronting with or covering a heated-air-exhausting opening 5 which is formed on the cover 4.
Function:
While the motor 2 is energized, heat is generated within it, however, the heated air is discharged through the air discharging openings 2c, because the air exhaust fan 2a is concurrently rotated. In this instance the heated air is not discharged into the closed space 7, as is the case with the conventional devices, but is discharged into the air collector body 1a of the air-exhaust duct 1, which air is led, successively through the air-exhaust passages 1b, the air-exhaust opening 1c, and the heated-air-exhausting opening 5, out into the open atmosphere.
As a result of functioning of this air exhaust system, the heat emitted from the motor 2 is not accumulated in the closed space 7, as it used to be in the conventional devices, that is the primary effect of this invention.
In this invention another remarkable effect can be observed; that is, the motor 2 concurrently functions as a ventilator for the closed space 7, because the motor is installed therein and the device is so constructed as to compulsorily discharge the exhaust air from the air-exhaust fan 2a out into the atmosphere. The motor 2 sucks air from the closed space 7 through the air suction opening 2b while it exhausts the heated air at the air discharging openings 2c, which results in flowing in of the same quantity fresh air from the atmosphere into the closed space 7. When there is a clearance or an opening for inletting fresh air between the frame 3 and the cover 4 at the overlapping portion thereof, the necessary amount of air naturally flows in; when it is needed, such as when the clearance is not large enough or it is purposely closed or non-existent, an air suction or inlet opening, such as the opening 3a (FIG. 1), or openings shall be made intentionally at preferable positions. In any way an air stream or flow, particularly a stream of fresh air from outside, is created in the closed space 7, which makes the space 7, contrary to such space in conventional forklift trucks, a most desirable place for the heat-sensitive and/or heat generating parts to be accommodated. This effect is especially conspicuous when the forklift trucks are employed in the sun, especially in the tropical geographic areas.
The cooling effect of the motor 2 itself, installing it in the closed space 7 in accordance with this embodiment shows a better result than installing it in an open space, which seems to be attributable to the fact that the cooling effect from the outside thereof is often better in the closed space than in the open space, while there is little difference, regarding the cooling within the motor 2, between the two instances. This is because the cooling of the external surface of the motor 2 is expedited by the air flow caused by the rotation of the same, for this purpose, however, the height of the duct or the thickness of the duct in the longitudinal direction of the electromotor should be determined as small as possible, so far as the duct can cover the discharging opening 2c of the electric motor. In order to positively utilize this cooling phenomenon, all that have to be done is to form an air suction opening to the left of the motor 2, for example, in FIG. 2. The air flows in the direction of arrows f shown in the Figure to increase the cooling effect at the external surface of the motor 2. Although the air exhaust duct 1 of the illustrated embodiment is constructed so it can be disassembled into two parts for the convenience of repairing the motor 2, a single piece, integral duct is of course permissible.
The location of the opening to exhaust the heated air is not necessarily restricted in the cover 4, nor is the number thereof is limited to one; at least one opening in a wall forming the external wall of the closed space is a requisite.
Summing up the effects of this invention, (1) a serious problem that has been accompanying the battery-powered forklifts, the superheat of the motor, has been perfectly dissolved with an excellent effect only by disposing an air exhaust duct and an opening in the external wall of the closed space, and (2) the closed space for installing the motor which has been thought to be a most unfavorable place for accommodating heatphobe parts has been ingeniously changed to a most preferable place for accommodating the same by suitably utilizing the motor as a ventilator for the same space.
It will be obvious to those skilled in the art that various changes may be made without departing from the scope of the invention and the invention is not to be considered limited to what is shown in the drawings and described in the specification.
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A device exhausting heated air generated by a heat source in a forklift truck, particularly a device discharging or exhausting heated air generated by an electromotor powered with batteries, which motor is placed in an almost covered space in a forklift, in order to get a cooling effect of the motor as well as the covered space, by utilizing an air exhaust fan which is provided in the motor and by providing an air exhaust duct covering the fan and an air exhausting opening in the wall of the covered space.
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RELATED APPLICATIONS
This is a U.S. National Phase Application under 35 U.S.C. § 371 of PCT Application No. PCT/US00/33529 filed Dec. 11, 2000, which claims the benefit of U.S. Provisional Patent Application Ser. No. 60/169,929 filed Dec. 10, 1999, the entire disclosures of which are expressly incorporated herein by reference.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention generally relates to a method and apparatus for sampling powder, and moves specifically to a method and apparatus for powder sampling which obtains undisturbed powder samples.
2. Related Art
Powdered materials are used in a wide range of industries. For example, an estimated 80% of pharmaceutical products take the form of tablets, which are compacts of powders. Powdered ingredients such as starches, flour, and sugars are essential raw materials in the food industry. Inorganic powders, such as oxides, nitrides, and carbides are used as raw materials in the ceramic industry. Detergents, abrasives, cosmetics, fertilizers, catalysts, etc., also involve processing powdered components.
Achieving homogeneous and well-characterized blends of powders and granules is a critical step in the manufacture of pharmaceutical tablets. Ineffective powder blending can result in increased variability in the contents of potent components in tablets, often resulting in rejection of finished product due to poor quality. If mixing inhomogeneities could be identified and/or avoided during the manufacturing process, fewer batches would be rejected, thus reducing manufacturing costs for existing products and perhaps decreasing time-to-market for new products.
At the present time, blending of granular materials is largely an art rather than a science. The ability to design and accurately assess a mixing process for a high potency drug is limited. Recognition of this problem has recently resulted in lawsuits and in tightening of FDA regulations. The situation is complicated by the lack of effective techniques for characterizing powder mixtures. In fact, the state of the art in sampling procedures (the thief probe) is often so inaccurate that it is possible for a high quality batch to be rejected due entirely to sampling error. Poor sampling capabilities have resulted in a lack of rigorous quantitative evaluations of actual powder mixing processes, further hindering both process development and quality control.
Characterization of homogeneity in a powder system is usually attempted by taking and analyzing discrete samples. The most common approach in stationary powder systems is to use a thief probe to withdraw samples from different locations. Thief samplers belong to two main classes, side-sampling and end-sampling. A typical side-sampling probe has one or more cavities stamped in a hollow cylinder enclosed by an outer rotating sleeve. The sleeve has holes that align with the cavities, allowing adjacent powder to flow into the cavities. An end-sampling thief has a single cavity at the end of the probe; such cavities can be opened and closed in a controlled manner. In both cases, the thief is introduced into the powder with the cavities closed. Once insertion is complete, the cavities are opened, allowing the powder to flow into them. The cavities are then closed, and the thief is withdrawn, removing samples from the mixture.
In principle, the homogeneity of the mixture may be statistically estimated from these samples. However, this estimate is meaningful only if the probe itself does not introduce errors. As mentioned above, this is not always the case. Errors are often introduced both when the theif probe is inserted into the powder bed and when powder flows into the thief cavities. In any sampling scheme, the experimentally measured variance, σ e 2 ,is actually a combination of the true variance resulting from the mixing process, σ m 2 , the variance introduced by sampling error, σ s 2 , and the variance resulting from chemical analysis, σ a 2 . In addition, for granular materials, any sample is composed of a finite number of particles, and there is a residual irreducible variance σ r 2 i.e.,
σ e 2 =σ m 2 +σ s 2 +σ a 2 +σ r 2 (1)
In an ideal situation, σ s 2 , σ a 2 and σ r 2 are negligible, and σ e 2 (the variance subject to USP rules) is almost identical to σ m 2 (the true variance). Unfortunately, thief probes often bias measurements to the point that sampling uncertainty is a large fraction of the measurement. Thief probes often introduce two types of errors: (i) the mixture is extensively disturbed when the thief probe is inserted into the powder bed, and (ii) particles of different size flow unevenly into the thief cavities. As a result of such errors, a homogeneous mixture can be deemed inadequate due entirely to sampling error.
Accordingly, what is needed, but has not heretofore been provided, is a powder sampling tool that preserves the homogeneity of the mixture and minimizes disturbance of the powder bed.
OBJECTS AND SUMMARY OF THE INVENTION
It is an object of the present invention to provide a thief probe system to render undisturbed samples in far more accurate and convenient manner than conventional thief probes.
It is another object of the present invention to provide a thief probe system that minimizes disturbance of a powder bed while obtaining samples.
It is an additional object of the present invention to provide a powder sampling method and apparatus which utilizes a cylindrical tube with a sharp or pointed circular lower edge for obtaining samples while minimizing disturbance of the powder.
It is a further object of the present invention to provide a powder sampling method and apparatus includes a cap for retaining powder within the sampler during retraction of the sampler from powder.
It is a further object of the present invention to provide a powder sampling method and apparatus which includes a mechanism for removing powder samples from the sampler.
The powder sampler of the present invention comprises a cylindrical tube with a lower end wherein the walls of the cylindrical tube taper to a sharp circular edge. The tube can be inserted into a powder bed to capture a powder sample within the tube. The sample remains within the tube based on arching, or alternatively, a cap can be used to retain the powder in the tube. The sample can then be removed from the tube in increments for testing. A powder extraction apparatus for removing the powder from the tube is included. The extraction apparatus comprises a push rod interconnected with threaded rod such that rotation of the threaded rod pushes the push rod through the cylindrical tube to push out the powder sample.
BRIEF DESCRIPTION OF THE FIGURES
Other important objects and features of the invention will be apparent from the following Detailed Description of the Invention taken in connection with the accompanying drawings in which:
FIG. 1 is a perspective view of the powder sampling apparatus of the present invention.
FIG. 2 is shows the powder sampling apparatus of FIG. 1 inserted into a powder.
FIGS. 3A , 3 B and 3 C show an embodiment of the apparatus of FIG. 1 with a capping fixture.
FIG. 4A is a top plan view and FIG. 4B is a side plan view of a core discharge fixture for removing a powder sample from the powder sampling apparatus.
FIG. 5 is a graph of core sample profiles of the interface between Avicel and lactose in a layered system.
FIG. 6 shows a plurality of sampling tubes extending through a template for taking a plurality of powder samples.
FIG. 7 shows an experimental set-up for taking a plurality of powder samples from a blender.
FIG. 8 illustrates the concentration profile for black sand versus depth for each core sampler.
FIG. 9 displays the axial profile after 30 revolutions
FIG. 10 shows nearly complete homogeneity is achieved after 240 revolutions.
DETAILED DESCRIPTION OF THE INVENTION
The present invention relates to a system for sampling powder from a vessel. The device may be herein referred to as a “core sampler.” As depicted in FIG. 1 , the core sampler of the present invention, generally indicated at 10 , comprises a cylindrical tube 20 , having an upper end 22 and a tapered lower end 24 which is tapered to a sharp angle 26 . The cylinder 20 has an inner wall 28 and an outer wall 29 . At the sharp angle 26 , the inner and outer walls 28 and 29 meet. The core sampler 10 could be constructed from stainless steel, but other strong metals or polymers would be equally suitable. To gather a sample, the core sampler 10 is inserted into a powder bed to a predetermined depth, thus isolating a cylindrical core of powder within the tube 20 . As shown in FIG. 2 , by using this approach, a nearly undisturbed column of powder is isolated inside the core sampler 10 .
Most materials of interest in pharmaceutical applications are sufficiently cohesive so that they do not drain out of the core sampler 10 under gravity. A simple cylindrical tube 20 is all that is required to pull a column of such powder from the bed. Cohesive powders resist flow due to gravity; they stick within the cylindrical tube 20 due to particle-particle and particle-wall frictional forces which lead to “arching.” Since the frictional forces of cohesive powders are high, cohesive powders are prone to arch. Arching will occur more readily in smaller diameter tubes, since the arching distance is decreased, and the ratio of tube surface area to volume of powder within the tube diameter is increased. Therefore, to increase the likelihood of extracting a sample of powder, smaller diameter core samplers may be used. Importantly, the core sampler of the present invention can be used to take vertical samples, samples at an angle, or even horizontal samples. Also, it should be noted that the inner diameter of the core sample can be varied in accordance with the powder being sampled and the size of the sample desired.
However, if smaller diameter cores are not practical, or for extremely free flowing powders, the core can be used with a capping fixture, as shown in FIGS. 3A , 3 B and 3 C. In this configuration, a fixture 40 designed to cap the end is attached to the exterior of the tube 20 by means of eyelets 42 . This capping fixture 40 has two components, (i) a plow rod 44 with a sharp conical plow 46 affixed at one end and a removable plow handle 48 on the opposite end, and (ii) a cap tube 50 with a thin circular disk or cap 52 affixed at one end and a removable cap handle 54 on the opposite end. The practice of using the core sampler 10 comprises of three steps. The starting configuration is depicted in FIG. 3 A. The cap tube 50 is slid through the eyelets 42 on the tube 20 and the cap handle 54 is attached at a marked position. The plow rod 44 is then slid within the cap tube 50 and the plow handle 48 is attached. In the starting position, the cap 52 rests flush on top of the plow 46 . In step 2, the core sampler 10 is inserted into a powder bed, generally indicated at 11 to a predetermined depth, as shown in FIG. 3B , thus isolating a cylindrical core of powder within the tube 20 . In step 3, the open end of the core tube 20 is capped so that the powder core remains in the tube 20 during extraction of the sampler from the powder bed 11 . To accomplish this, the plow rod 44 and cap tube 50 are further extended into the powder bed 11 to a level where the cap 52 is just below the level of the core tube 20 . The cap tube 50 is then rotated so that the cap 52 covers the end of the core tube 20 . Once the sampler is capped, it is pulled from the powder bed, as shown in FIG. 3 C. Importantly, the plow 46 and cap 52 do not interfere with the sample within the tube 20 . Rather, the cap and plow 52 are moved to below the opening of the tube 20 after the sample is already in the tube 20 , thereby eliminating disturbance of the sample by the plow 46 and cap 52 .
The present invention also includes a reliable and robust method for discharging the core sample. Since it is desirable to subdivide the powder column into a number of undisturbed samples of controlled weight, the discharge fixture must withstand very large forces sometimes required to move cohesive powders through small diameter cores. The core discharge fixture is generally indicated at 60 in FIGS. 4A and 4B . The fixture 60 comprises a tube holder 62 having an upright flange 63 attached to a metal base 64 . The upright flange 63 has an aperture slightly larger than the cylindrical tube 20 for receiving and holding the cylindrical tube 20 . Locking screws, not shown, may be used to retain the cylindrical tube 20 securely in place during sample extraction. A push rod 70 is inserted into the cylindrical tube 20 to push the powder sample therefrom. The push rod 70 is driven through the cylindrical tube 20 by a ram comprising a sliding platform 74 . The push rod 70 is mounted on the platform 74 by mount support 72 . The platform 74 is mechanically coupled to a linear motion system comprising a precision-threaded rod 76 , a handwheel 78 , guide rails 80 , and collars 82 and 84 . One collar 82 links the sliding platform to the precision-threaded rod 76 , while the other collars 84 connect the sliding platform to the guide rails 80 . The linear motion system is attached to the base 64 , so no relative motion occurs between the cylindrical tube 20 and the linear motion system. The guide rails 80 are interconnected with the base 64 by attachment to pillow blocks 81 . When the handwheel 78 is rotated, the precision-threaded rod 76 turns, moving the sliding platform 74 forward, sending the push rod 70 linearly through the cylindrical tube 20 . Sample size is controlled by the number of turns on the handwheel 78 . In cases where the material is free flowing, the core discharge fixture 60 can be held at angle of inclination greater than the complement of the angle of repose of the powder. This insures that powder is discharged due to the action of the discharge device and not from gravitational flow.
The performance of the core sampler was evaluated using a layered system of microcrystalline cellulose (Avicel, FMC Corporation) and granulated lactose. The lactose was dyed red in order to distinguish it visually from microcrystalline cellulose, which is white. The powders were classified by sieving. The Avicel exhibited a particle size less than 90 microns. The lactose exhibited a particle size ranging from 500 to 710 microns, nominally 600 microns. A layered system of lactose on top of microcrystalline cellulose was formed in a 2000 ml beaker with a diameter of approximately 4 inches. The Avicel layer was 4 inches thick; the lactose layer was 2.5 inches thick.
The performance of three core samplers with different size inner diameters, ⅞ inch, {fraction (11/16)} inch and {fraction (7/16)} inch, were evaluated. The core samplers were used in the manner described in the previous section. The volume of the collected sample may be approximated by the inner diameter of the tube multiplied by the distance which the screw ram is driven between collections. By controlling the number of rotations of the screw driven ram, the size of the collected sample and therefore the number of samples collected from each core was varied. Typically the ram was extended between 0.2 inches and 0.4 inches between samples, corresponding to samples weighing between 0.4 grams and 2 grams. Highly uniform sample weight was achieved by monitoring the sample weight during discharge from the core. Sample weight variability was much lower (relative standard deviation=2%) than for the thief probes described above.
FIG. 5 demonstrates the ability of the core sampler to accurately profile the interface between Avicel and lactose in a layered system. In these cases, the extracted core of powder was divided into approximated 20 smaller sections. The composition of the sections was determined by sieve separation (recall the Avicel had a much smaller particle size). The interface between the Avicel and lactose is sharply resolved, with little contamination of Avicel in the lactose layer or vice versa. The axial resolution of the technique was determined to be less than 1 centimeter. That is, the contamination of powder from one stratum to the next is limited to less than 5% after a distance of 1 centimeter. In contrast, other commercial thief probes yield a much smaller number of samples, require similar or larger amount of labor, and exhibit significantly greater contamination.
To describe the uniformity of powder within a large vessel it is often necessary to sample many locations. The core sampler of the present invention is efficient at extracting a column of powder from the vessel, with tight axial resolution, but it is also necessary to take samples at different radial positions. Insertion of the core sampler into the powder bed does disrupt the powder outside of the sampler, especially in cases where the plowing and capping rod are used. It is necessary to take into account the size of the disrupted zone of powder in order to determine the minimum lateral separation between sampling locations required for accurate sampling.
The disrupted zone of powder can be visualized using layered systems. Most of the disruption is caused by the insertion of the plowing and capping rod. On the side of the capping and plowing rods, the disrupted zone of powder extends for up to 5 centimeters from the core. On the side opposite of the capping and plowing rod, the disrupted zone of powder extends less than 1 centimeter from the core. When the capping and plowing rods are used (as would be the case for free flowing powders), a conservative recommendation for the minimum recommended separation between sampling locations is 5 core diameters. When the capping and plowing rods are not used (as in most cases) the minimum separation between sampling locations is 2 core diameters.
Removal of the core sampler causes significant disruption to the powder bed, because powder outside the sampler collapses into the gap left by removal of the core, disrupting powder several centimeters away. Therefore, in order to maintain the highest amount of radial resolution, an adequate strategy for sampling is to insert all of the core samplers into the powder vessel prior to removing any of them. In this manner, the disturbances to the powder bend during removal of the core cannot affect the powder isolated within the other cores.
As an example, core samplers were used to describe the characterization of blend homogeneity in a 2 cubic foot Tote-Blender manufactured by GEI Galley. This device is an asymmetric tumbler with the bottom section shaped as a hopper and the top a rectangular box. The axis of rotation does not bisect the blender into two equal halves but rather a skewed partition in order to break the symmetry of rotation.
White and Black Art Sand from Clifford W. Estes Co., Inc., located in Lyndhurst, N.J. was mixed in the tote-blending experiments. The range of particle size was between 0-500 μm for both colors. Although the sand used in these experiments was free flowing, the core samplers with the capping rod in place did not yield enough samples, necessitating the use of simple cores. A successful sampling strategy was implemented as follows:
(1) At the end of the mixing experiment, the lid of the blender was removed, and a sampling grid, was attached to the top of the blender to maintain consistency in spacing and straight passage through the granular bed as shown in FIGS. 6 and 7 .
(2) Core samplers were introduced into the mixture without removing any of them.
(3) Tests in layered system showed that the infiltration process did not disturb the sand within the cores.
(4) The samplers were removed discharged in a controlled manner to subdivide them into multiple samples.
The cores used had an inner diameter of 0.75 inches and the rods were inserted 3.5 inches apart. A total of nine rods spanned the spaced allotted by the opening of the blender.
The sampling procedure and the time spent on each step are provided below for the case of one operator performing the sampling alone.
1. Fix the sampling grid on the tote-blender opening upon completion of a mixing experiment (1 minute).
2. Insert the core samplers into the grid holes making sure the pass through the sand bend until their bottom contact the inner hopper walls (1 minute).
3. Extract each core sampler, take it to the discharge device, and extrudate the sample from each sampler, dividing it into “unit does” samples. This procedure takes 9 minutes.
4. The next step is to process the individual unit-dose samples using an appropriate method of analysis. Time required for this procedure obviously depends on the chemical nature of the material and therefore was not estimated for a general case.
The outcome of this sampling procedure is concentration data. FIG. 8 illustrates the concentration profile for black sand versus depth for each core sampler. The initial condition for this experiment had the black and white sand loaded side by side, each on a different side of the baffle, filling 40% of the total volume of the vessel. FIG. 9 displays the axial profile after 30 revolutions. As it is the case for all tumbling mixers, axial mixing is slow; the regions that had initially one color of sand remained high in concentration of that color for this particular experiment. Cores 7 , 2 , 6 are placed in the initially black sand region (positive x-axis), while cores 8 , 4 , 9 are in the initially white region (negative x-axis). Cores 3 , 1 , 5 approximately sample the division line between the colors as shown in FIG. 7 . The entire set of 106 values is reported in Table 1. Mean composition measured by the procedure is 50.44%, in excellent agreement with the amount of black sand initially loaded to the vessel. The RSD is 49%, demonstrating that the mixture is still far from homogeneous after 30 revolutions. As shown in FIG. 10 , nearly complete homogeneity is achieved after 240 revolutions.
In summary, it must be concluded that samples obtained using conventional thief probes are likely to contain significant errors. The insertion of a thief probe into a mixture causes extensive disturbances of the mixture structure, dragging particles along the path of insertion of the thief. The sample that is finally collected is likely to contain particles from all positions along the path. Even in the best case, samples were contaminated by particles originally located as far as 5 to 10 cm away from the sampling location causing errors of 10% or more, i.e., considerably larger than desirable for an accurate characterization of mixture structure.
The device of the present invention enables the extraction of an undisrupted column of powder from a vessel. The column of powder may then be sectioned into subunits using a specially designed discharge device. This allows one to render a large number of representative samples from a powder bed. The core sampler is able to resolve the interfacial layer with an axial resolution of less than 1 centimeter. The radial resolution is demonstrated to be equal to the diameter of the core. Therefore, the described sampling technique is a significantly more accurate means to extract undisturbed powder samples from an intended location. Additionally, the technique is more efficient and may be used to render a larger number of samples with less labor. Also, the weight of the collected samples is controllable. Given these advantages over conventional powder samplers and thieves, the sampling device described here is a simpler and better technique for determining content uniformity of powder within a vessel.
Having thus described the invention in detail, it is to be understood that the foregoing description is not intended to limit the spirit and scope thereof. What is desired to be protected by Letters Patent is set forth in the appended claims.
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A powder sampling method and apparatus is provided for sampling powder from a mixer or a drum. An undisturbed column of powder is extracted from a vessel. The column of powder may then be sectioned into subunits, using a discharge device, providing up to dozens of samples per insertion. Larger number of representative samples of controlled size from a powder bed can be acquired.
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CROSS-REFERENCES TO RELATED APPLICATIONS
[0001] This is a division of U.S. patent application Ser. No. 10/914,570, filed Aug. 7, 2004.
FIELD OF THE INVENTION
[0002] The present invention generally relates to a printed circuit board, and more specifically to a method for fabricating embedded thin film resistors of a printed circuit board.
BACKGROUND OF THE INVENTION
[0003] In general, besides using conventional discrete passive elements, a printed circuit board can also use a thick film or a thin film process to develop the resistors required. In the thick film process, the resistors of the printed circuit board are made of carbon paste printed on the printed circuit board. Then the resistances of the resistors are fine-tuned by the laser trimming. In the thin film process, on the other hand, a nickel-plated copper foil and the epoxy resin of the printed circuit board is pressed together during the fabricating process of the printed circuit board. The nickel-plated side of the copper foil faces toward the printed circuit board and the non-plated side of the copper foil faces outward. Then, in a subsequent photolithography process, an acid etching solution is first used to etch both the copper and nickel layers, and then an alkaline etching solution is used to etch away the copper layer. A number of nickel blocks with the required dimensions are thereby formed. Laser is then used to trim each of the nickel blocks to achieve the precise resistance required.
[0004] In addition, currently, there is an electroless deposition technology that can replace the foregoing thin film method for building the resistor blocks to form thin film resistors.
[0005] In conventional thick film resistor fabricating methods, using high curing temperature carbon paste for the resistors is rather simple, mature, and less costly. However, because the laminate of the printed circuit board is susceptible to high temperature, low curing temperature carbon paste is usually used. The macromolecular polymer contained in the low curing temperature carbon paste will remain in the formed resistors even after the curing and solidification processes of the resistors. The hydrophilic property of the macromolecular polymer is the major factor causing the resistances of the resistors to vary along with the environmental change. Therefore, resistors having constant and precise resistances are difficult to achieve. On the other hand, the conventional thin film methods use the same temperatures and solutions as the conventional printed circuit board fabrication methods. The fabricated embedded resistors also have better stability and accuracy than those made by thick film methods. However, because the nickel-plated copper foil is difficult to manufacture, there are only limited supply sources and therefore the price is high. Although there are methods using the electroless deposition technology, the fabricated thin film resistors have inadequate adherence due to certain process factors. The application of these methods for mass production is thereby limited. Accordingly, the present invention is aimed at overcoming problems and disadvantages of conventional methods for fabricating thin film resistors of printed circuit boards.
SUMMARY OF THE INVENTION
[0006] The method provided by the present invention can be applied to single-sided, double-sided, multi-layered, and build-up printed circuit boards. The present invention develops at least a resistor layer in at least any one layer of the printed circuit board. The resistor layer is then etched to form a number of resistor elements required by the circuit layout of the printed circuit board.
[0007] The embedded thin film resistors made by the present invention replace the bulky conventional discrete resistors. The printed circuit board can therefore have finer circuit layout and much smaller size. The capacitive reactance effect usually found at the connectors of conventional discrete resistors is also avoided. The signal transmission speed and quality of the printed circuit board is therefore significantly enhanced, especially for high frequency applications. The process for forming the resistor layer provided by the present invention is very similar to that used for ordinary printed circuit boards and can be carried out using the same equipment. Therefore there is no significant investment on new equipment. The process for forming the resistor layer provided by the present invention, just like the process for ordinary printed circuit boards, is applicable in mass production and contributes to a significant lower manufacturing cost.
[0008] The foregoing and other objects, features, aspects and advantages of the present invention will become better understood from a careful reading of a detailed description provided herein below with appropriate reference to the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0009] FIG. 1 is a flow chart showing the steps of forming embedded thin film resistors on a printed circuit board according to a first embodiment of the present invention.
[0010] FIGS. 2 ( a )- 2 ( f ) are schematic diagrams showing the various steps of FIG. 1 respectively.
[0011] FIG. 3 is a flow chart showing the steps of forming embedded thin film resistors on a printed circuit board according to a second embodiment of the present invention.
[0012] FIGS. 4 ( a )- 4 ( i ) are schematic diagrams showing the various steps of FIG. 3 respectively.
[0013] FIGS. 5 ( a )- 5 ( e ) are schematic diagrams showing the various steps of depositing multiple resistor layers respectively according to the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0014] FIG. 1 is a flow chart showing the steps of forming embedded thin film resistors on a printed circuit board according to a first embodiment of the present invention. These steps are described sequentially as follows.
[0015] In step 101 , as shown in FIG. 2 ( a ), the conductive wires 21 with resistor wells 22 are formed on a substrate made of an insulating polymer according to layout requirement of circuitry.
[0016] The foregoing conductive wires 21 and resistor wells 22 can be formed using an ordinary printed circuit board fabrication process such as the subtractive, additive, or semi-additive process. The conductive wire 21 is made of copper, aluminum, other well conductive material, or an alloy of the above.
[0017] In step 102 , as shown in FIG. 2 ( b ), an activated layer 3 is coated on top of at least surface of each resistor well 22 so as to activate the insulating polymer of the substrate 1 exposed by each resistor well 22 .
[0018] The foregoing activated layer 3 is made of activated palladium (Pd) or other appropriate activator that can be used to form the activated layer using a printing, spraying, or dipping method.
[0019] In step 103 , as shown in FIG. 2 ( c ), the printed circuit board is immersed in an electroless nickel solution so that a resistor layer 4 with an expected thickness is plated on the activated layer 3 .
[0020] The foregoing resistor layer 4 can be made of a nickel-phosphorus, palladium-phosphorus, ruthenium-phosphorus, or other metallic material having considerable resistance characteristics.
[0021] In step 104 , as shown in FIG. 2 ( d ), an etching resist 5 is coated on the resistor layer 4 , based on the locations and dimensions of the resistors required by the printed circuit board.
[0022] The foregoing etching resist 5 is made of etching resistible dry film, wet film, ink, plastic film, or solder mask ink, and can be formed by a screen printing or photolithography process.
[0023] In step 105 , as shown in FIG. 2 ( e ), the resistor layer 4 is etched to form a number of resistor elements 41 and contact points 42 matching the locations and dimensions of the etching resist 5 . On two ends of each of the resistor elements 41 , contact points 42 are formed so that each resistor element 41 is connected to the conductive wires 21 .
[0024] In step 106 , as shown in FIG. 2 ( f ), the etching resist 5 on the resistor layer 4 is stripped away.
[0025] The foregoing etching resist 5 on the resistor layer 4 may not be stripped away if the etching resist 5 is made of solder mask ink.
[0026] In step 107 , the shape and dimension of each resistor element 41 of the resistor layer 4 is adjusted to obtain accurate resistance by laser trimming.
[0027] At the end of this step, each resistor element 41 of the resistor layer 4 can be coated with protective ink. The protective ink is then heated and solidified so that subsequent processes of the printed circuit board do not affect the resistance of each resistor element 41 . The coating and solidification of the protective ink can also be conducted before the laser trimming. In this way, undesirable influence of the ink coating and solidification on the resistances of the resistor elements 41 can be avoided after their resistances are adjusted by laser trimming.
[0028] FIG. 3 is a flow chart showing the steps of forming embedded thin film resistors on a printed circuit board according to a second embodiment of the present invention. These steps are described sequentially as follows.
[0029] In step 201 , as shown in FIG. 4 ( a ), a conductive layer 2 is formed on a substrate 1 made of an insulating polymer. The conductive layer 2 is then processed, based on the locations and dimensions of the resistors required by the printed circuit board, to form the corresponding resistor windows 23 .
[0030] The conductive layer 2 is made of copper, aluminum, other well conductive material, or an alloy of the above.
[0031] In step 202 , as shown in FIG. 4 ( b ), an activated layer 3 is coated on top of at least surface of each resistor window 23 of the conductive layer 2 so as to activate the insulating polymer of the substrate 1 exposed by each resistor window 23 .
[0032] The foregoing activated layer 3 is made of activated palladium (Pd) or other appropriate activator that can be used to form the activated layer 3 using a printing, spraying, or dipping method.
[0033] In step 203 , as shown in FIG. 4 ( c ), the printed circuit board is immersed in an electroless nickel solution so that a resistor layer 4 with an expected thickness is coated on the activated layer 3 .
[0034] The foregoing resistor layer 4 can be made of a nickel-phosphorus, palladium-phosphorus, ruthenium-phosphorus, or other metallic material having considerable resistance characteristics.
[0035] In step 204 , as shown in FIG. 4 ( d ), an etching resist 5 is coated on the resistor layer 4 , based on the locations and dimensions of the layout of the conductive wires and the resistor windows required by the printed circuit board.
[0036] The foregoing etching resist 5 is made of etching resistible dry film, wet film, ink, plastic film, or solder mask ink, and can be formed by a screen printing or photolithography process.
[0037] In step 205 , as shown in FIG. 4 ( e ), the resistor layer 4 and conductive layer 2 are etched together according to the locations and dimensions of the etching resist 5 so that the layout of conductive wires 21 of the conductive layer 2 and the resistor windows required by the printed circuit board are formed.
[0038] In step 206 , as shown in FIG. 4 ( f ), the etching resist 5 on the resistor layer 4 is stripped away.
[0039] In step 207 , as shown in FIG. 4 ( g ), an etching resistible etching resist 5 ′ is coated on the resistor layer 4 , based on the locations and dimensions of the resistors required by the printed circuit board.
[0040] In step 208 , as shown in FIG. 4 ( h ), the resistor layer 4 is etched to form a number of resistor elements 41 matching the locations and dimensions of the etching resist 5 ′. On two ends of the resistor elements 41 , contact points 42 are formed to connect with the conductive wires 21 of the conductive layer 2 .
[0041] In step 209 , as shown in FIG. 4 ( i ), the etching resist 5 ′ on the resistor layer 4 is stripped away.
[0042] The foregoing etching resist 5 ′ on the resistor layer 4 may not be stripped away if the etching resist 5 ′ is made of solder mask ink.
[0043] In step 210 , the shape and dimension of each resistor element 41 of the resistor layer 4 is adjusted to obtain accurate resistance by laser trimming.
[0044] In the foregoing steps 205 to 209 , the layout of conductive wires 21 is first formed by etching the conductive layer 2 and the resistor elements 41 is then formed by etching the resistor layer 4 . If higher degree of accuracy is required, the etching of the conductive layer 2 and resistor layer 4 can be conducted together so that the layout of conductive wires 21 and each of the resistor elements 41 are formed according to the locations and dimensions of the etching resist 5 . The etching resist 5 is then stripped away. Subsequently, the conductive layer 2 and resistor layer 4 is coated with another etching resist 5 ′ according to the locations and dimensions of the resistors required by the printed circuit board. Then the superfluous resistor layer 4 on the conductive layer 2 is etched away. Each individual resistor elements 41 has two contact points 42 connecting with the conductive wires 21 of the conductive layer 2 . The etching resist 5 ′ is then stripped away.
[0045] At the end of the foregoing process, each resistor element 41 of the resistor layer 4 can be coated with protective ink. The protective ink is then heated and solidified so that subsequent processes of the printed circuit board do not affect the resistance of each resistor element 41 . The coating and solidification of the protective ink can also be conducted before the laser trimming. In this way, undesirable influence of the ink coating and solidification on the resistances of the resistor elements 41 can be avoided after their resistances are adjusted by laser trimming.
[0046] The resistance of the resistor element 41 depends on the thickness and dimension of the resistor element 41 , and the volume resistivity of the material used for the resistor layer 4 . Since the thickness and volume resistivity of the resistor elements 41 are the same because they are all developed from the same deposition of resistor layer 4 , adjusting the dimension of the resistor elements 41 is the only way to differentiate the resistance among the resistor elements 41 . For resistor elements 41 having a large resistance, their shape would be much longer or narrower than those having a smaller resistance. Therefore there is a range limitation on the resistance achievable by varying the dimension of the resistor elements 41 . To overcome these disadvantages, multiple resistor layers 4 can be deposited. As shown in FIG. 5 ( a ), to form a number of resistor elements 41 having similar resistance, a resistor layer 4 having a specific volume resistivity and thickness is deposited first. Then the foregoing process is applied to form the required resistor elements 41 as shown in FIG. 5 ( b ). The resistor elements 41 all have identical thickness and volume resistivity. Their resistances are then fine-tuned by adjusting their dimensions. Then, as shown in FIG. 5 ( c ), a protective film is coated to protect the resistor elements 41 in subsequent operations. Then, for another set of required resistor elements 41 ′, another resistor layer 4 ′ having a specific volume resistivity and thickness is deposited as shown in FIG. 5 ( d ). The same process is repeated to form the required resistor elements 41 ′ as shown in FIG. 5 ( e ). The resistor elements 41 ′ all have identical thickness and volume resistivity. Their resistances are then fine-tuned by adjusting their dimensions. Similarly additional resistor layers can be deposited so that resistor elements can have a large variance in their resistances. The process can be conducted on the same layer or on different layers of a printed circuit board if the printed circuit board has more than one layer.
[0047] The resistor elements 41 and 41 ′ of the resistor layer 4 and 4 ′ respectively can have their dimensions etched or laser-trimmed simultaneously at the end so as to achieve the desired resistances.
[0048] In addition, the method provided by the present invention can be applied to single-sided, double-sided, multi-layered, and build-up printed circuit boards. In these printed circuit boards, at least a resistor layer 4 is formed in at least any one layer of these printed circuit boards and etched to obtain the resistor elements 41 required by the circuit layout of the printed circuit boards. Electrical connections are then established between the resistor elements 41 and the conductive wires 21 .
[0049] Although the present invention has been described with reference to the preferred embodiments, it will be understood that the invention is not limited to the details described thereof. Various substitutions and modifications have been suggested in the foregoing description, and others will occur to those of ordinary skill in the art. Therefore, all such substitutions and modifications are intended to be embraced within the scope of the invention as defined in the appended claims.
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A method for fabricating the embedded thin film resistors of a printed circuit board is provided. The embedded thin film resistors are formed using a resistor layer built in the printed circuit board. Compared with conventional discrete resistors, embedded thin film resistors contribute to a smaller printed circuit board as the space for installing conventional resistors is saved, and better signal transmission speed and quality as the capacitive reactance effect caused by two connectors of the conventional resistors is avoided. The method for fabricating the embedded thin film resistors provided by the invention can be conducted using the process and equipment for conventional printed circuit boards and thereby saving the investment on new types of equipment. The method can be applied in the mass production of printed circuit boards and thereby reduce the manufacturing cost significantly.
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ORIGIN OF THE INVENTION
The invention described herein was made by an employee of the United States Government and may be manufactured and used by or for the Government of the United States of America as governmental purposes without the payment of any royalties thereon or therefor.
DESCRIPTION
Technical Field
The present invention is concerned with mechanical means for pumping hydraulic fluids by extracting the energy from a motive high pressure gas with high efficiency. Secondly, it is concerned with pumping the hydraulic fluid under constant pressure for constant hydraulic horsepower demand. The invention may also be called a high efficiency free-piston hydraulic pump. Obviously, it may be driven in reverse to operate as a gas compressor.
Background of the Invention
The invention may be used in a space vehicle, which dictates a hydraulic pump occupying less space and having a weight less than conventional gas turbine powered rotating hydraulic pumps. It also demands a pump requiring less maintenance and looser tolerances, and one in which parts that are prone to wear out are quickly and cheaply replaced.
Prior Art
The nearest known art is found in U.S. Pat. Nos. 3,170,605; 3,613,169; 3,823,651; 3,961,559; 4,192,482 and 3,695,785. None of these, however, embody the applicant's concept of extracting maximum energy from the driving gas in a blowdown chamber and providing a force multiplier ring which couples the gas piston to the hydraulic piston by engaging variable pitch grooves in both pistons.
GENERAL DISCLOSURE OF THE INVENTION
The present invention utilizes an outer cylindrical housing and piston having a blow-down chamber at one end, and an inner cylinder and piston at the other (hydraulic) end, the inner assembly extending coaxially within the outer piston and being reversed from end to end so that the head of the inner piston exerts pressure on hydraulic fluid admitted through the hydraulic end of the outer cylinder.
The driving gas in the blowdown chamber is not vented out of the assembly until the outer (or gas) piston nears the end of its stroke and uncovers an appropriately located vent or until varying in port 12 is switched to vent. This, of course, means that the pressure driving the gas piston is considerably lower during the last part of the stroke by comparison with the starting pressure. To prevent a like reduction in the force exerted by the hydraulic piston on the fluid being pumped, the two pistons are coupled together by a force multiplier ring which is mounted on the inner cylinder so that it can be rotated but not moved axially (while both pistons move axially but can not be rotated).
To ensure that the pressure on the hydraulic fluid does not diminish from its starting value during a constant hydraulic horsepower demand, even though the gas pressure is allowed to fall off as the gas expands, this ring is mounted to engage both a first helical groove in the inner surface of the gas piston and a second helical groove in the outer surface of the hydraulic piston.
Each of these grooves is of variable pitch, and one is the opposite of the other. The pitch of the gas piston groove increases as this piston passes through its stroke, while the pitch of the hydraulic piston groove decreases correspondingly. Since each groove must pass through the same axial point continuously, i.e., where the anti-friction bearing surfaces of the force multiplier ring enter the grooves, movement of the gas piston an axial distance corresponding to one revolution of its helical groove rotates the ring by camming action, and the same camming action on the hydraulic piston forces it to advance an axial distance corresponding to one revolution of its helical groove. The mathematical form of the helices is determined from the requirement that the pressure exerted by the hydraulic piston remain constant during constant hydraulic horsepower demand while the gas pressure gradually falls off, and will be apparent to those of ordinary skill in the art. The variable pitch profile may be tailored to match a hot gas thermal pressure decay profile; again, such technique will be apparent to those of ordinary skill in the art. The hydraulic pressure capability is determined by the gas to hydraulic piston area ratio and the initial gas pressure.
The invention provides further applications in weight, cost, and space savings by providing a compact unit which can be designed as an integral part of a hydraulic actuator.
The gas and hydraulic piston area ratio may be reversed if high flow-low pressure hydraulic power is desired.
BRIEF DESCRIPTION OF THE DRAWING
The present patent includes a drawing illustrating one preferred embodiment of the invention. In such drawing:
FIG. 1, consisting of one piston set, is a somewhat conceptualized depiction of the invention in longitudinal section, this view showing the pistons at the end of a power stroke.
FIGS. 2, 3 and 4 are half-sections similar to FIG. 1, showing in rather schematic form the relative positions of the pistons at the start, intermediate and final positions they occupy during a power stroke, respectively (FIG. 4 being the same as FIG. 1).
DETAILED DESCRIPTION OF THE DRAWING
The figures show a one piston set assembly in which the fixed parts of the gas-to-hydraulic power converter 1 include the outer cylinder 2 and the inner or smaller cylinder 4, the latter being an integral extension from the hydraulic closer end 6 of the outer cylinder 2; this cylinder is coaxial with the outer cylinder and spaced therefrom by an annulus. The opposed end 8 of the outer cylinder, containing the damper half 10, may be denominated the gas closure 8 because it contains the gas entry port 12, and because this end of the cylinder 2 contains the blowdown chamber 14. A similar damper half is provided by the blind hole 16 in the hydraulic closure 6. Hydraulic fluid is admitted through this closure by one of the conduits 18, with the flow directionally controlled by valves 20. Hydraulic fluid is pumped out the other conduit 18.
The outer or gas cylinder 2 has a cylindrical sidewall 3 provided with an exhaust vent 5. As shown in FIGS. 1 and 4, this vent is not uncovered to permit the escape of the driving gas until the pistons have completed their power stroke. The sidewall 3 also contains an axial groove 7 formed from its bore surface 9, such groove serving as a guide for the gas piston 30 and preventing rotation of the piston by its engagement of the bearing lug 33 protruding from the outer surface of gas piston 30.
The principal moving parts of the depicted gas-to-hydraulic power converter 1 are the gas piston 30, the hydraulic piston 40, and the force multiplier ring 50. As illustrated, the gas piston 30 has the integrally connected head 31 facing the gas closure end 8 of the cylinder and the open-ended cylindrical sidewall 32 extended toward the hydraulic end 6. The hydraulic piston 40 is oppositely disposed within the cylindrical sidewall 4 of the inner cylinder, i.e., with its head 41 facing the hydraulic end 6 of the assembly and with its open-ended cylindrical sidewall 42 extending toward the gas end. Each of the pistons 30 and 40 is axially slideable within its cylinder, making sealing contact with inner sidewall surfaces 9 and 11 respectively, using the indicated seals. Rotation of the gas piston 30 is prevented by the above mentioned interfit of bearing lug 33 in groove 7 of cylinder wall 3, while rotation of the hydraulic piston 40 is prevented by a bearing lug 34 projecting from the head 31 of gas piston 30 into an axial groove 43 of hydraulic piston sidewall 42.
As seen in FIG. 1, the head 41 of hydraulic piston 40 has a damper half 45 which engages the damper half 16. These two elements form a damper to reduce metal-to-metal impact load between the piston and the closure as hydraulic piston 40 reaches the end of its stroke. A similar half damper 35 projecting from the head 31 of gas piston 30 engages the half damper 10 of gas closure 8, for the same purpose. Various damper types other than that illustrated could be used.
It will be noted that as the pistons are depicted in FIG. 1, the sidewall 42 of hydraulic piston 40 extends beyond the sidewall 4 of the inner cylinder, and confronts the inner surface 36 of the gas piston sidewall 32 across an unobstructed annulus. The ring 50 or rather the head 52 thereof is disposed in this space and extends across it so that outside antifriction bearing surface 54 extends into a helical groove 37 in the sidewall 32 of the gas piston, from inside surface 36, and inside antifriction bearing surface 56 extends into another helical groove 46 formed in the hydraulic piston sidewall 42 from its outer surface 47. The ring 50 also includes the sleeve portion 51 disposed coaxially about the common axis 15 of the assembly and integrally secured to the head portion 52. The sleeve portion 51 is rotatably mounted on the inner cylinder 4 by means of the indicated bearings 58, which together with spacers 59 also serve to prevent the ring 50 from making any axial movement.
In operation, the pistons 30 and 40 are moved from the position of FIG. 1 to the starting position of FIG. 2 by utilizing the hydraulic fluid from inlet conduit 18 as the driving fluid; this is readily accomplished because the blowdown chamber 14 has just been exhausted of any high pressure gas, and inlet gas valving 12 ducts to exhaust.
Turning to FIG. 2, it will first be noted that the relative positions of the pistons 30 and 40 are such that the free end 48 of hydraulic piston 40 is in contact with the head 31 of gas piston 30, and the antifriction bearing surfaces 54 and 56 of the ring 50 are near the extreme right hand ends of the two variable pitch grooves 37 and 46. A predetermined quantity ("slug") of gas is admitted to the blowdown chamber 14 through entry vent 12, for instance by connecting vent 12 to an auxiliary storage tank (not shown) by a valve (not shown). The important feature is that this slug of gas has an initial pressure and an initial mass, and thereafter there are no additions to the mass of the gas until the cycle is ready to be replicated. The gas may be a hot gas resulting from a decomposition process carried on in an auxiliary chamber, or integral to chamber 14, or may be a compressed cold gas held therein intermittently, i.e., disconnected from any compressed gas source during the power strokes of the pistons.
As this slug of gas acts on piston head 31, it causes piston 30 to move toward the hydraulic closure 6 of the assembly, increasing the size of chamber 14. As the sidewall slides in this direction, the trailing wall defining its helical groove 37 cams the engaging antifriction bearing surface 54 to rotate ring 50 and its inside antifriction bearing surface 56. Antifriction bearing surface 56 in turn rotates against the leading wall defining helical groove 46 of the hydraulic piston 40, causing this piston to advance. Since the pitches of the two grooves are opposed, that of groove 37 in the gas piston 30 increasing (by comparison with FIG. 2) while groove 46 of the hydraulic piston 40 is decreasing, during the first stages of the power stroke the hydraulic piston necessarily advances farther than the gas piston. This may be seen in FIG. 3 by the distance "X", which is precisely the excess of the advance of piston 40 over that of piston 30. Since in this figure each piston has advanced an axial distance corresponding to 4 revolutions of the ring 50, as may be seen by counting groove tracks from right to left in FIG. 3, the distance "X" is also equal to the difference in the axial spacings of these groove tracks, between track 1 and track 5.
In proceeding from the FIG. 3 intermediate position to the FIG. 4 end position of the pistons, which in the illustration corresponds to 3 revolutions of the ring 50, the gas piston 30 moves through the higher pitch portions of its groove 37 while the hydraulic piston 40 moves through its smaller pitch portions. Stated another way, the force multiplier functioning is such that the hydraulic piston 40 necessarily moves a shorter distance than the gas piston 30, as may be seen by comparing the distance "X" in the two figures. As previously mentioned, such relative movement results from the requirement of injecting a slug of gas at the outset and letting it decrease in pressure as it drives the gas piston and at the same time keeping a constant pressure on the hydraulic fluid, or in other words moving the hydraulic piston at a constant velocity during constant hydraulic horsepower demand.
Among the advantages of the invention are the space and weight savings resulting from the high efficiency gas cycle; if the gas pressure were kept constant at an elevated pressure during the entire power stroke, more gas generating and storage equipment would be required. In addition it may be pointed out that the two pistons and the force multiplier ring are easily replaced, that close fit clearances are not required between either piston and its cylinder (as in conventional hydraulic piston pumps), and that there are no rotating shaft seals, as is common in prior art hydraulic pumps, that frequently cause early failures thereof.
Another advantage is that the pistons are stationary, that is not stroking, when zero hydraulid flow is required although the hydraulic pressure is maintained. This contrast to constant rotating pumps, either electric motor or turbine powered.
By utilizing proper external or port valving, multiple piston set assemblies may be included to reduce stroke switching pressure ripple and/or increase flow capacity. Such techniques will be apparent to those of ordinary skill in the art.
In multiple piston set assembly pumps, the expended gas from one cylinder may, through a design configuration change, be used to help return another piston assembly set to its starting position. This modification will also be apparent to those of ordinary skill in the art.
It is to be understood that the foregoing description of a particular preferred embodiment is illustrative only, and that the scope of the invention is to be limited only as limited in the appended claims, which should be broadly construed to embrace all substantially similar means for accomplishing substantially the same result in a substantially similar manner.
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A gas piston driven hydraulic piston pump in which the gas cycle is of high efficiency by injecting the gas in slugs at the beginning of each power stroke. The hydraulic piston (40) is disposed to operate inside the gas piston (30), and the two pistons, both slidably but non-rotatably mounted, are coupled together with a rotating but non-sliding motion transfer ring (50) extending into antifriction grooves (46 and 37) in the sidewalls (42 and 32) of the two pistons. To make the hydraulic piston move at a constant speed during constant hydraulic horsepower demand and thus exert a constant pressure on the hydraulic fluid, these grooves are machined with variable pitches and one is the opposite of the other, i.e., the gas piston groove (37) increases in pitch during its power stroke while the hydraulic piston groove (46) decreases. Thus the motion transfer ring (50) is properly denominated a force multiplier ring. Any number of piston assembly sets may be used to obtain desired hydraulic horsepower.
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