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REFERENCE TO RELATED APPLICATIONS
[0001] This application claims priority to European Patent Application No. 11405267.3, filed Jun. 10, 2011, the disclosure of which is incorporated herein by reference.
BACKGROUND OF THE INVENTION
[0002] The invention relates to a linear position measuring system and to a method for determining the absolute position of a carriage along a slide rail.
[0003] For example, systems for determining the position of a carriage are used in combination with guide systems, e.g., linear guides, which encompass a first body and a second body guided on the first body that can move relative to the first body, and here have the job of making it possible to determine the position of the second body relative to the first body. To this end, for example, a measuring scale of the respective device for determining a position can be fixed in place relative to the first body, for example, and a respective scanner can be fixed in place relative to the second body.
[0004] For example, there are linear position measuring systems known in the art for determining an absolute position that encompass the measuring scale marked with measuring points and a scanner that can move relative to the measuring scale for scanning the respective measuring points. For example, these measuring points consist of one or more acquirable markings to identify a position. The markings can be acquired optically or magnetically, for example.
[0005] In optical scanning, the scanner encompasses a sensor for acquiring an image of the measuring points and providing signals making it possible to determine the position of the scanner relative to the measuring scale. In magnetic scanning, the scanner encompasses a magnetic field sensor for acquiring a magnetic field progression of individual permanent magnets, which in this case make up the measuring points of the measuring scale.
[0006] Depending on the respective measuring scale (optical/magnetic), these types of systems can be used, for example, to measure a relative change in the position of the scanner in relation to an initial position, or to record an absolute position of the scanner.
[0007] To reach a point where these types of systems become able to measure relative changes in position of the scanner in relation to the measuring scale, for example, the respective measuring scale can be designed as an incremental scale, and consequently acquire a sequence of several identical, periodically arranged markings spaced apart at equal distances along a prescribed line or measuring scale. For example, to enable the optical scanning of such an incremental measuring scale, the scanner can project an optical image of the respective markings onto a sensor in the form of a photoelectric detector. To measure relative changes in position of the scanner in relation to the measuring scale, the scanner is moved along the track of markings. Moving the scanner here causes a signal to change periodically, for example providing information about how many markings the scanner passed by.
[0008] In addition, signals recorded for various positions of the scanner along the track of markings can be interpolated, making it possible to determine the position of the scanner relative to the markings to within an inaccuracy of less than the distance between adjacent markings.
[0009] In sum, the respective change in the relative position of the scanner can be determined by scanning the measuring points of an incremental measuring scale. So-called incremental position encoders are used for this purpose, which have a comparatively simple design. They offer relatively high resolutions.
[0010] Aside from acquiring the relative movement between the slide rail and track carriage or scanner, the system can also be designed to determine an absolute position of the scanner in relation to a reference scale. The respective absolute position of the scanner can here be determined at any location along the slide rail by measuring a change in the relative position of the scanner in relation to a specific reference point. The reference point must here be scanned in an especially reliable manner, since any misinterpretation would lead to completely erroneous information about the position of the carriage in relation to the slide rail.
[0011] To this end, the reference scale can exhibit one or more reference points along a predetermined line, which each specify a certain absolute position. In order to determine the position, the aforementioned scanner can be moved along the predetermined line, so as to optically or magnetically scan the respective reference points by means of the scanner.
[0012] In sum, these so-called absolute encoders always transmit the position-related information in its entirety, which makes them very well suited for determining and controlling position. The conventional approach involves reading out a piece of binary information, wherein a corresponding optical or magnetic scan is needed for each binary digit. All of these scans must be adjusted relative to each other so that no read error can arise under any circumstances. As the requirements placed on scanning accuracy become ever more stringent, the computation time and power consumption for this purpose increase.
[0013] In the past, the reference points were evaluated using only a simple threshold circuit. Exceeding the threshold causes the function to be digitized. The advantage to this is that plausibility examinations can be performed. The reference signal is here generated by a half bridge. In terms of practical implementation, this half bridge can be realized in the form of the north/south pole of a permanent magnet. An alternating signal results from scanning the magnetic field of a permanent magnet during the relative movement of a scanner along the permanent magnet. For example, the threshold can be set as a function of the desired sensitivity and the amplitude of the alternating signal, or the distance between the peak values (peak-peak). The distance between the peak values can here be influenced by the magnetization width. The position of the peak values is here independent of the measuring signal strength.
[0014] One problem in this approach toward determining the position by scanning the reference point is that the reference pulse width can be varied in relation to the signal amplitude. In the event of a super-elevated signal amplitude, this can result in a reference pulse that is too wide for reliable evaluation. By contrast, if the signal amplitude is too low, reference pulse detection may be mistakenly omitted altogether.
[0015] Another problem lies in the occurrence of overshoots. In practice, an output variable will not reach the desired value after a sudden change in an input variable, e.g., the magnetic field of the permanent magnets, but rather will overshoot the set value, and only adjust or settle into the desired value thereafter. In cases where the reference point is acquired by scanning a magnetic field progression, this phenomenon arises primarily when the reference sensor is in a highly saturated region. As a result, magnetic field lines can be acquired that emerge in the near field of the reference pulse in the opposite direction. This distorts the result of reference point scanning.
[0016] Another problem associated with acquiring the reference point by scanning a magnetic field progression is that mechanical tools with a residual magnetization can apply magnetic poles to the reference track after the fact. Since these imposed interferences result in magnetic poles having a respective width longer than the width of the permanent magnets of the reference track, this leads to a lower amplitude. In addition, the distance between the peak values is reduced. The measuring result of the reference point scan as a whole are greatly distorted as a result.
OBJECTS AND SUMMARY OF THE INVENTION
[0017] The object of the present invention is to provide a linear position measuring system for determining an absolute position of a carriage along a slide rail in which these problems of prior art are resolved.
[0018] This object is achieved by the features in claim 1 .
[0019] A linear position measuring system for determining an absolute position of a carriage along a slide rail contains a reference scale placed along the slide rail and a scanner secured to the track carriage. The scanner is designed to scan reference points along the reference scale, wherein the reference points can be scanned as an essentially analog signal progression, which consists of sequential first and second signal half-wave progressions. The linear position measuring system further encompasses at least one threshold storage device for storing a first and second threshold, whose levels can be varyingly adjusted relative to each other. The linear position measuring system further encompasses a first comparator for comparing the scanned values of the first signal half-wave progression with the first threshold in a sectional interval of the first signal half-wave progression, and to output: those scanned values of the first signal half-wave progression that are less than the first threshold to a first measured value register for storing those values as a first discrete SW 1 half-wave bit value, and those scanned values of the first signal half-wave progression that are greater than the first threshold to the first measured value register for storing those values as a second discrete SW 1 half-wave bit value. The linear position measuring system further encompasses a second comparator for comparing the scanned values of the second signal half-wave progression with the second threshold in a sectional interval of the second signal half-wave progression, and to output: those scanned values of the second signal half-wave progression that are less than the second threshold to a second measured value register for storing those values as a first discrete SW 2 half-wave bit value, and those scanned values of the second signal half-wave progression that are greater than the second threshold to the second measured value register for storing those values as a second discrete SW 2 half-wave bit value. The linear position measuring system further contains a first set measured value register for storing set measured values for the values in the sectional interval of the first signal half-wave progression, and a second set measured value register for storing set measured values for the values in the sectional interval of the second signal half-wave progression, wherein the measured value registers and set measured value registers exhibit an identical bit length. The linear position measuring system further contains at least one logical comparison module for comparing the respective contents of the first and second measured value register with the contents of the first and second set measured value register, and for outputting a differential value from this comparison. The linear position measuring system further contains a tolerance range comparator for comparing the differential value with a predetermined tolerance range, and, based on this comparison, to acquire and output each reference point as an ideal reference point if the differential value lies within a predetermined tolerance range.
[0020] One significant advantage is that this yields a redundant reference point acquisition that enables a precise definition of the reference pulse flanks. This makes it possible to check the plausibility of the acquired values. Another advantage lies in the fact that scanning is a particularly energy-efficient process, so that the power required for this purpose can be supplied from at least one battery or an accumulator. As opposed to conventional linear position measuring systems, this advantageously eliminates the need to provide electrical lines to supply power. The contents of the measured value register (MR 1 , MR 2 ) can be maps of the function f(x)=reference value>SW 1 and f(x)=reference value<SW 2 .
[0021] The reference points are preferably designed as individual permanent magnets, whose respective magnetic field progression can be scanned by the scanner. This enables particularly accurate scanning, since magnetic field scanning is especially insusceptible to interference by comparison to other scanning methods. In addition, scanning can take place at an especially fine resolution, since the permanent magnets can have a particularly narrow width in comparison to other configurations for scanning points.
[0022] The reference points are preferably designed as optical markings, which can be scanned by the scanner. Markings applied to the reference track are here scanned by optical reading heads. This optical scanning is especially cost-effective to realize in comparison to other scanning methods.
[0023] The set measured values are preferably based on at least one error detection simulation. This prevents the acquisition of distorted signal patterns based on an injected interference, for example by magnetic tools. This ensures pure signal scanning.
[0024] The respective first threshold level and second threshold level are preferably based on at least one error detection simulation. The linear position measuring system can be configured to store more than the first and second threshold. For example, the first and second signal half-wave progressions can sequentially follow a sinusoidal wave progression. The values for the first signal half-wave progression can here assume positive values, and the values for the second signal half-wave progression can assume negative values. In this example, the first threshold can be set to a positive level, and the second threshold can be set to a negative level. An especially finely tuned adjustment is enabled overall for achieving a highly accurate scanning.
[0025] The linear position measuring system is preferably designed to prescribe the scanning time based on the reference points at multiples of a 180° angle. The incremental values here prescribe the scanning time at angles of 0°, 180°, 360°, etc.
[0026] The linear position measuring system is preferably designed to interpolate the reference point given a shift in the scanning point angle. One advantage lies in the fact that a reliable position determination is still possible even given a shift in the scanning point angle, for example owing to carriage acceleration. For example, the angle can be shifted by 20°, 200°, etc.
[0027] The aforementioned object is also achieved by means of a method for determining an absolute position of a carriage along a slide rail, with a reference scale placed along the slide rail and a scanner secured to the track carriage. The scanner scans at least one reference point along the reference scale, wherein the reference point is scanned as an essentially analog signal progression, which consists of sequential first and second signal half-wave progressions. The method involves the following steps:
[0028] a) Storing at least one first threshold and one second threshold, wherein their levels are varyingly adjusted relative to each other,
[0029] b) In a sectional interval of the first signal half-wave progression:
[0030] Comparing the scanned values of the first signal half-wave progression with the first threshold by means of a first comparator,
[0031] Outputting those scanned values of the first signal half-wave progression that are less than the first threshold to a first measured value register, and storing those values as a first discrete SW 1 half-wave bit value,
[0032] Outputting those scanned values of the first signal half-wave progression that are greater than the first threshold to the first measured value register, and storing those values as a second discrete SW 1 half-wave bit value,
[0033] c) In a sectional interval of the second signal half-wave progression:
[0034] Comparing the scanned values of the second signal half-wave progression with the second threshold by means of a second comparator,
[0035] Outputting those scanned values of the second signal half-wave progression that are less than the second threshold to a second measured value register, and storing those values as a first discrete SW 2 half-wave bit value,
[0036] Outputting those scanned values of the second signal half-wave progression that are greater than the second threshold to the second measured value register, and storing those values as a second discrete SW 2 half-wave bit value,
[0037] d) Storing set measured values for the values in the sectional interval of the first signal half-wave progression, and set measured values for the values in the sectional interval of the second signal half-wave progression in a respective first and second set measured value register, wherein the measured value registers and set measured value registers exhibit an identical bit length,
[0038] e) Comparing the respective contents of the first and second measured value register with the contents of the first and second set measured value register by means of a logical comparison module, and outputting a differential value from this comparison, and
[0039] f) Comparing the differential value with a predetermined tolerance range by means of a tolerance range comparator and, based on this comparison, acquiring and outputting each reference point as an ideal reference point if the differential value lies within a predetermined tolerance range.
[0040] One significant advantage to the method according to the invention is that it yields a redundant reference point acquisition that enables a precise definition of the reference pulse flanks. This makes it possible to continuously check the plausibility of the acquired values. Another advantage lies in the fact that scanning can be done in a particularly energy-efficient manner. As a result, the power required for reference point acquisition can be supplied from at least one battery or an accumulator. This advantageously eliminates the need to install electrical lines to supply power.
[0041] The reference points are preferably designed as individual permanent magnets, whose respective magnetic field progression is scanned by the scanner. This enables particularly accurate scanning, since magnetic field scanning is especially insusceptible to interference by comparison to other scanning methods. In addition, scanning can take place at an especially fine resolution, since the permanent magnets can have a particularly narrow width in comparison to other configurations for scanning points.
[0042] The reference points are preferably designed as optical markings, which are scanned by the scanner. In this method, optically detectable markings applied to the reference scale are scanned by optical reading heads. This type of scanning is especially cost-effective to realize in comparison with other scanning methods.
[0043] The method preferably further involves the step of generating the set measured values based on at least one error detection simulation. This prevents the acquisition of distorted signal patterns in advance. Such distorted signal patterns can be based on an injected magnetic interference, for example caused by magnetic tools. This ensures an overall pure signal scanning.
[0044] The method preferably further involves the step of generating at least the level of the first threshold and the level of the second threshold based on at least one error detection simulation. This enables an especially finely tuned adjustment for achieving a highly accurate scanning.
[0045] The scanning time is preferably prescribed based on the reference points at multiples of a 180° angle. As a consequence, the incremental values prescribe the scanning time at angles of 0°, 180°, 360°, etc.
[0046] The reference point is preferably interpolated given a shift in the scanning point angle. As a result, a reliable position determination is still permanently ensured even given a shift in the scanning point angle, for example owing to carriage acceleration. For example, the angle can be shifted by 20°, 200°, etc.
[0047] Various other objects, advantages and features of the present invention will become readily apparent to those of ordinary skill in the art, and the novel features will be particularly pointed out in the appended claims.
BRIEF DESCRIPTION OF THE DRAWINGS
[0048] The following detailed description, given by way of example and not intended to limit the present invention solely thereto, will best be appreciated in conjunction with the accompanying drawings, wherein like reference numerals denote like elements and parts, in which:
[0049] FIG. 1 is a detailed view of a linear position measuring system, which depicts a magnified section of a slide rail; and
[0050] FIG. 2 is an analog signal progression resulting in response to a magnetic field progression that is scanned by means of a scanner in the linear position measuring system guided along a reference scale.
DETAILED DESCRIPTION OF THE INVENTION
[0051] FIG. 1 presents a detailed view of a linear position measuring system 10 , which depicts a magnified flank section of a slide rail 12 of the linear position measuring system 10 . The slide rail 12 is used to guide a carriage, to which a scanner is fixedly secured (neither is shown). An incremental scale 14 and a reference scale 16 are applied to the flank of the slide rail 12 .
[0052] The incremental scale 14 consists of adjacently arranged permanent magnets 18 , which are alternately aligned in the N-S, N-S, etc. direction. By way of illustration, the resultant magnetic field progressions are schematically depicted.
[0053] In order to be able to measure relative changes in position of the scanner in relation to the incremental scale 14 , the carriage with the scanner is moved along the track of the permanent magnets 18 . The scanner movement here results in a periodic change in a measuring signal in response to the magnetic field progression of the individual permanent magnets 18 . This periodic change in the measuring signal provides information about the number of permanent magnets 18 by which the scanner was moved. This in turn gives an indication of the distance traversed by the carriage in relation to the slide rail 12 and time.
[0054] The reference scale 16 also secured to the slide rail 12 contains individual reference points 20 , which are arranged in such a way that an absolute position of the scanner can be determined in relation to the reference scale 16 . The respective absolute position of the scanner can here be determined at any location along the slide rail 12 by measuring a change in relative position of the scanner in relation to a specific (e.g., coded) reference point 20 . The reference points 20 must here be scanned in an especially reliable manner, since any misinterpretation would lead to completely erroneous information about the position of the carriage in relation to the slide rail 12 .
[0055] FIG. 2 shows an analog signal progression S resulting in response to a magnetic field progression of a reference point that is scanned by means of a scanner guided along a reference scale (neither is shown). According to the invention, a first threshold SW 1 and a second threshold SW 2 are set and stored.
[0056] In a timeframe (t=0 to T 1 ) of positive half-wave values for the signal progression S, which is referred to as the first signal half-wave progression S 1 , those scanned values of the analog signal progression S that are less than the first threshold SW 1 are stored as a first discrete SW 1 half-wave bit value. In the example shown on the figure, this value assumes the binary value “0”. This binary value “0” is stored in a first measured value register MR 1 .
[0057] In the timeframe of positive half-wave values (t=0 to T 1 ) for the signal progression S (first signal half-wave progression S 1 ), those scanned values of the analog signal progression S that are greater than the first threshold SW 1 are stored as a second discrete SW 1 half-wave bit value. In the example shown on the figure, this value assumes the binary value “1”. This binary value “1” is also stored in the first measured value register MR 1 . Therefore, the bit sequence (content) 01100xxx is stored in the measured value register MR 1 .
[0058] Further, in a timeframe (t=T 1 to T 2 ) of negative half-wave values for the analog signal progression S, which is referred to as the second signal half-wave progression S 2 , those scanned values of the analog signal progression S that are greater than the second threshold SW 2 are stored as a first discrete SW 2 half-wave bit value. In the example shown on the figure, this value assumes the binary value “0”. This binary value “0” is stored in a second measured value register MR 2 .
[0059] In the timeframe (t=T 1 to T 2 ) of negative half-wave values for the analog signal progression S (second signal half-wave progression S 2 ), those scanned values of the analog signal progression S that are less than the second threshold SW 2 are stored as a second discrete SW 2 half-wave bit value. In the example shown on the figure, this value assumes the binary value “1”. This binary value “1” is stored in the second measured value register MR 2 . Therefore, the bit sequence (content) xxxx0110 is stored in the measured value register MR 2 .
[0060] The linear position measuring system further incorporates a first set measured value register and a second set measured value register (neither is shown), which each store respective set measured values for the values in the timeframe of positive half-wave values (first signal half-wave progression S 1 ) and set measured values for the values in the timeframe of negative half-wave values (second signal half-wave progression S 2 ). These set measured values are based on simulations. The measured value registers MR 1 , MR 2 and the set measured value registers can each exhibit an identical bit length.
[0061] A logical comparison module, for example a comparator, compares the respective contents of the first and second measured value register MR 1 , MR 2 with the contents of the first and second set measured value register. For example, the first set measured value register stores the bit sequence 01100xxx, and the second set measured value register stores the bit sequence xxxx0110. In this example, as a result of comparing the stored contents of the first set measured value register with the contents stored in the first measured value register MR 1 , the logical comparison module outputs a signal indicating a correlation between the contents (plausibility). In addition, as a result of comparing the stored contents of the second set measured value register with the contents stored in the second measured value register MR 2 , the logical comparison module outputs a signal indicating a correlation between the contents.
[0062] Based on this comparison (complete correlation), the linear position measuring system thus acquires the scanned reference point of the reference pattern as an ideal reference point. The linear position measuring system can be designed to acquire the reference point of the reference pattern as an ideal reference point even if the comparison yields an incomplete correlation, but the difference between the stored contents of the first and/or second set measured value register and the contents stored in the first and/or second measured value register MR 1 , RM 2 lies within a predetermined tolerance range.
[0063] However, if this difference lies outside the predetermined tolerance range, the linear position measuring system is designed to discard the acquired signal progression. In other words, the linear position measuring system is configured not to take into account this signal progression as a reference point. As a result, the linear position measuring system is prevented from erroneously acquiring a signal progression, for example arising from an overshoot or residual magnetization, as the reference point. This tangibly increases the overall reliability of reference point acquisition. The reduced scanning rate by comparison to prior art also clearly reduces power consumption by the scanner. This advantageously enables the scanner to derive its power from an accompanying battery or an accumulator.
[0064] The present invention has been described in the context of a number of embodiments, and multiple variations and examples thereof. It is to be understood, however, that other expedients known to those skilled in the art or disclosed herein may be employed without departing from the spirit of the invention.
[0065] Therefore, it is intended that the appended claims be interpreted as including the embodiments described herein, the alternatives mentioned above, and all equivalents thereto.
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A linear position measuring system and a method for determining an absolute position of a carriage along a slide rail are disclosed. An analog signal progression (S) based at on at least one reference point is here discretely scanned in response to a first threshold (SW 1 ) and second threshold (SW 2 ). The resultant digital values are stored in a first measured value register (MR 1 ) and a second measured value register (MR 2 ). The contents of the first and second measured value register (MR 1 , MR 2 ) are compared with the respective contents of a first and second set measured value register. The reference point is output as an ideal reference point if the differential value lies within a predetermined tolerance range, and is otherwise discarded.
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BACKGROUND OF THE INVENTION 1. Field of the Invention
This invention relates to a process for the production of quaternary ammonium salts of fatty acid hydroxyalkanesulfonic acids, in which a hydroxyalkanesulfonic acid is subjected to the condensation reaction with a C 6-18 fatty acid at elevated temperature and reduced pressure, any water of solution present and the water of reaction formed are directly removed from the reaction mixture and the fatty acid hydroxyalkanesulfonic acid is reacted with a base to form the corresponding quaternary ammonium salt of the fatty acid hydroxyalkanesulfonic acid. 2. Description of the Related Art
Fatty acid hydroxyalkanesulfonic acid salts, more particularly fatty acid isethionates in the C 12-14 chain length range, are anionic surfactants with only minimal sensitivity to hardness, high foaming and wetting power and excellent compatibility with the skin. More particularly, they are distinguished by the fact that the skin can be cleansed without overly drying out. In addition, the soaps containing these compounds can even be used by people unable to tolerate typical high pH soaps. Accordingly, these compounds are used in cosmetic preparations and cleansing formulations
Commercial fatty acid hydroxyalkanesulfonic acid salts are generally produced from the corresponding salt of hydroxyalkanesulfonic acid by reaction with the fatty acid in the presence of an esterification catalyst, for example ZnO, at temperatures of up to 250° C. However, dark-colored products are obtained in the production of ammonium fatty acid hydroxysulfonic acid salts by this process.
The fatty acid isethionates, particularly the sodium fatty acid isethionates frequently used, show only limited solubility in water which restricts their use to soaps, such as syndets and combination bars and opaque liquid formulations.
Quaternary ammonium salts of fatty acid hydroxyalkanesulfonic acids, more particularly ammonium fatty acid isethionate, are highly soluble in water and may be used in clear liquid formulations. However, this possibility is impaired by the fact that the quaternary ammonium salts of fatty acid isethionic acid prepared by conventional methods are dark in color so that, in the absence of bleaching, the liquid formulations containing them are also dark in color.
The problem addressed by the present invention was to provide a process for the production of quaternary ammonium salts of fatty acid hydroxyalkanesulfonic acids which would enable these compounds to be obtained in high yields and in light-colored highly concentrated form.
SUMMARY OF THE INVENTION
This invention relates to a process for making a quaternary ammonium salt of a fatty acid hydroxyalkanesulfonic acid comprising the steps of: (a) reacting a hydroxyalkanesulfonic acid of the formula (I):
HO--(C.sub.n H.sub.2n)--SO.sub.3 H (I)
wherein n=2 to 4 with a fatty acid of the formula (II):
R.sup.2 COOH (II)
wherein R 2 CO is an aliphatic, linear or branched acyl radical having from 6 to 18 carbon atoms at a temperature range of from about 60° C. to about 120° C. and at a pressure sufficient to vaporize water at said temperature range to form a reaction mixture comprised of said fatty acid hydroxyalkanesulfonic acid while removing water from a reaction mixture; (b) dissolving said reaction mixture in an organic solvent; (c) forming a quaternary ammonium salt of said fatty acid hydroxyalkanesulfonic acid by reacting said reaction mixture with a base at a temperature of 18° C. to 35° C.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
It has surprisingly been found that it is possible by the process according to the invention to produce high yields of quaternary ammonium salts of fatty acid hydroxyalkanesulfonic acids which are light in color. The process according to the invention may be carried out at considerably lower temperatures than known processes and without a catalyst.
In the process according to the invention, the hydroxyalkanesulfonic acid and the fatty acid are first subjected to the condensation reaction at temperatures of 60° to 120° C. and preferably at temperatures of 90° to 110° C. Any water of solution present and the water of reaction formed are directly distilled off. The molar ratio of fatty acid to hydroxyalkanesulfonic acid is in the range from 1.5:1 to 1:1.5 and preferably in the range from 1:1 to 1:1.2.
The condensation reaction is preferably carried out with no additional catalyst. The advantage of carrying out the reaction in this way is that there is no need for the removal of the catalyst from the reaction product otherwise necessary in condensation reactions and no catalyst residues are present in the reaction product.
The hydroxyalkanesulfonic acid used is preferably used in water-free form. Water present in the starting substances is distilled off at the beginning of the reaction. The hydroxyalkanesulfonic acid may readily be produced from its salts. It is preferably obtained from the sodium salt via acidic ion exchangers.
The fatty acid used as starting product corresponding to general formula (II) R 2 COOH is selected from caproic acid, oenanthic acid, caprylic acid, pelargonic acid, capric acid, undecanoic acid, undecenoic acid, lauric acid, lauroleic acid, tridecanoic acid, myristic acid, myristoleic acid, pentadecanoic acid, palmitic acid, palmitoleic acid, heptadecanoic acid, stearic acid, petroselic acid, petroselaidic acid, oleic acid, elaidic acid, linoleic acid, linolaidic acid, linolenic acid, elaeostearic acid and technical mixtures thereof. Fatty acids on a vegetable or animal basis, which may be completely or partly hydrogenated, are preferred. Mixtures of coconut oil fatty acid are particularly preferred.
The condensation reaction is carried out under a pressure under which water boils so that the water of reaction can readily be removed. A pressure in the range from about 2 to 100 mbar is preferred, water jet vacuum being particularly preferred.
The reaction mixture of hydroxyalkanesulfonic acid and fatty acid is heated in vacuo. The mixture should be heated only slowly because the reaction mixture can foam in vacuo at the beginning of the reaction. The beginning and end of the reaction are reflected in the formation of water of reaction. On completion of the reaction, the reaction mixture is kept at elevated temperature for about another 20 minutes to 1 hour to remove any water present. Removal of the water can be accelerated by addition to the reaction mixture of an organic solvent which forms a low-boiling azeotrope with water and which removes the water as an azeotrope from the reaction mixture.
The mixture is then dissolved in an inert organic solvent. Suitable solvents are any solvents with which the condensation product forms a homogeneous solution. Particularly suitable solvents are aliphatic and aromatic hydrocarbons, such as n-hexane, petroleum ether, isooctane; halogenated hydrocarbons, such as methylene chloride, chloroform or carbon tetrachloride; and alcohols, such as methanol, ethanol, n-propanol and i-propanol or mixtures thereof. Petroleum ether or a mixture of petroleum ether and i-propanol is preferably used.
The dissolved condensation product is reacted with a base at a temperature of 18° C. to 35° C. and preferably at a temperature of 20° C. to 27° C. The base may be used in the form of a pure substance or may be diluted with a corresponding solvent or inert gas. Suitable bases are, for example, ammonia, primary, secondary and tertiary (lower) alkylamines, in which lower alkyl is an alkyl containing 1 to 4 carbon atoms, or aminoalcohols, in which the alcohol is a lower alcohol containing 1 to 4 carbon atoms, and glucamine. Examples of suitable alkyl amines are monomethyl amine, monoethyl amine, monopropyl amine, monobutyl amine, dimethyl amine, diethyl amine, dipropyl amine, dibutyl amine, trimethyl amine, triethyl amine, tripropyl amine, tributyl amine. Examples of suitable alkanolamines are, for example, trimethanolamine, triethanolamine, tripropyl amine and tributyl amine.
The quaternary ammonium salt of the fatty acid hydroxyalkanesulfonic acid formed generally accumulates in the form of a white precipitate. On completion of the reaction, the reaction product is isolated in known manner. The solid product can normally be filtered off from the reaction mixture and subsequently washed with fresh solvent or solvent mixture several times, generally at least twice, and then dried in vacuo. If the product is soluble in the solvent, the solution obtained may be directly further processed or the product is obtained by distilling off the solvent.
The reaction according to the invention gives a white powder in a high yield of generally more than 90%.
The invention is illustrated by the following Example.
Example
About 57.9 g of isethionic acid (93%, 0.427 mole) and 85.53 g lauric acid (0.427 mole) were combined under nitrogen and heated in a water jet vacuum. The reaction actually began below 100° C. and was accompanied by gentle foaming. The main reaction was terminated after 1 h. The reaction mixture was kept at a maximum temperature of 120° C. for another 30 minutes.
11.8 g water and small quantities of lauric acid distilled over (theoretical: 11.6 g water). The resulting reaction mixture (131.6 g) was dissolved in 1.4 liters petroleum ether and ammonia was passed through with stirring at 25° C. The quaternary ammonium salt precipitating was washed three times with fresh petroleum ether and dried in a water jet vacuum. 135 g of a white powder were obtained. The product had the following composition:
approximately 91 to 93% of lauroyl isethionate NH 4 salt (determined by Epton titration of the anionic surfactant content)
approximately 2 to 3% of lauric acid NH 4 salt (determined by HPLC) and
approximately 5 to 7% of ammonium isethionate (determined by HPLC).
After filtration and washing with the solvent, the product had a Klett color value of 49 (1 cm cuvette, 30% solution) whereas a commercial product had a Klett color value of 69 (1 cm cuvette, 30% solution).
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Quaternary ammonium salts of fatty acid hydroxyalkanesulfonic acids are made by reacting a hydroxyalkanesulfonic acid of the formula (I):
HO--(C.sub.n H.sub.2n)--SO.sub.3 H (I):
wherein n=2 to 4 with a fatty acid having from 6 to 18 carbon atoms at a temperature range of from about 60° C. to about 120° C. and at a reduced pressure followed b reaction with an amine in an organic solvent.
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BACKGROUND OF INVENTION
[0001] 1. Field of the Invention
[0002] This invention is in the field of printing, more specifically in transferring images for printing techniques, and still more specifically in the field of making flexographic printing plates with flat top dots. The invention is also in the field of transferring images from one surface to another.
[0003] 2. Description of the Related Art
[0004] A common method of preparation of a simple flexographic (“flexo”) printing plate from a so-called analog sheet photopolymer (such as supplied by, for example, DuPont, Kodak, or Flint Group) currently involves the steps of (a) printing a black negative image on a white substrate; (b) photographing the negative image; (c) developing the film negative; (d) positioning the film negative on top of the sheet photopolymer in a special exposure unit; (e) placing a thin plastic vacuum sheet over the negative; (f) applying a vacuum to the laminate thus formed (vacuum sheet, negative, and sheet photopolymer); (g) exposing this laminate to actinic radiation through the negative for an amount of time sufficient to create a crosslinked polymerized image in the photopolymer; (h) removing the laminate from the unit and separating the vacuum sheet and negative from the exposed sheet photopolymer; and (i) mechanically removing the uncrosslinked photopolymer from the sheet with a solvent to develop a relief image.
[0005] The vacuum step (f) is critical in this process. If there are any pockets of air between the negative and the surface of the photopolymer, the UV light will be refracted by the interfaces between the air, the film and the photopolymer and the final image after exposure will be distorted. If the pockets of air are large enough, they can even lead to mechanical failure of the plate by creating thin spots in the photopolymer. Moreover, ambient oxygen in any air pockets in contact with surface of the photopolymer inhibits full curing of the photopolymer all the way to the photopolymer surface. (This is thought to be because oxygen in the air reacts with gases formed within the photopolymer layer during UV curing, the products of which slow the curing rate.) Provided the negative and vacuum sheet are skillfully placed, the vacuum system in the special exposure unit will remove a great majority (but not all) such pockets of air. The high vacuum capability of the special exposure unit is one reason the exposure unit is so expensive.
[0006] All of the above steps except perhaps (c) and (f) require human handling and make the entire process slow. For this reason, a method combining or eliminating some of these steps is called for to speed the process and permit a simpler and less expensive exposure unit to be used.
[0007] Another common method of preparing a flexo plate involves creating a negative image directly on the opaque-coated side, or thermal layer, of a so-called digital photopolymer sheet (also called computer-to-plate or CTP, such as supplied by, for example, DuPont, Kodak, or Flint Group) by ablating portions of the thermal layer using, for example, an IR laser. This technique has the advantage of eliminating the need for a film negative and the distortion effects of air bubbles trapped under the negative, but unless a vacuum sheet or a coating is applied on top of the ablated surface to keep air out during UV exposure, full curing of the photopolymer all the way to the surface is still inhibited. Further, in the case of CTP imaging, the image material itself can release water vapor under high vacuum, which can collect into pockets. Thus, no matter whether the image is applied in the form of a film negative or ablated into digital sheet photopolymer, small relief detail such as halftone dots do not have flat tops and cannot transfer ink with sufficiently sharp image edges onto the surface to be printed. It has also been determined that flexo plates with flat top dots last longer (endure more impressions) than rounded dots because they distribute the impact stress more evenly throughout the polymer. There is thus a need for methods of imaging photopolymer sheets which solve these problems.
[0008] Another art related to the instant invention is that of placing images on surfaces that cannot be run through a printer, such as walls, furniture, doors, and windows. The prior art includes painting, applique, stenciling and etching. All of these techniques are more or less skill, labor, and time intensive. There is a need for a rapid and less skill-intensive method.
BRIEF DESCRIPTION OF THE INVENTION
[0009] The methods of the instant invention relate to printing. The first method is for transferring fine detail inkjet images onto analog photopolymer sheets to produce flexo plates with flat top dots. The second method relates to preventing photopolymer exposure to air during curing or formation of gas bubbles using digital flexo plate technology, again to produce flexo plates with flat top dots. These two methods eliminate the aforementioned problems with gas bubbles, reduce the number of steps required and the level of expertise necessary to execute them, produce flexo plates with better flat top dots, and produce final prints of higher quality, than achievable by current methods under the best of conditions. The third method of the invention provides a way to transfer printed images to non-porous surfaces that cannot be run through a printer, such as windows.
[0010] All of these methods begin by preparing a preliminary laminate of an inkjet-receptive emulsion/release coating (hereinafter referred to as a “release coating”) onto a plastic, e.g., polyester, backing sheet. Once the preliminary laminate is made, a protective film may be placed over the release coating for storage and handling, to be removed before use in the invented methods.
[0011] In the first method, a clear release coating is imaged and used to transfer its image to an analog photopolymer sheet by the application of a clear adhesive to the photopolymer sheet followed by application of the image side of the preliminary laminate to the adhesive. A first laminate of the instant invention is thus created. It is possible to get the same result, of course, by applying the adhesive to the image side of the preliminary laminate instead of the photopolymer sheet. The adhesive must be compatible with both the image material, the release coating, and the photopolymer to which the preliminary laminate is being affixed. The adhesive should be a fast self-curing resin that produces a stronger bond between the image material and the photopolymer surface than exists between the release coating and the backing sheet. Once the adhesive cures, the backing sheet is peeled off the release coating and image material. The sheet photopolymer so imaged is then exposed to actinic radiation (without the need for vacuum) and processed normally.
[0012] In the second method of the instant invention, involving a pre-imaged photopolymer sheet such as a digital plate, the adhesive is applied to the imaged photopolymer, followed by application of the preliminary laminate to the adhesive. A second laminate of the instant invention is thus created. As with the aforementioned first method, it is possible to get the same result by applying the adhesive to the preliminary laminate instead of the photopolymer sheet. Again, the adhesive must be compatible with both the image material and the non-porous surface to which the preliminary laminate is being affixed, and should be a fast self-curing resin that produces a stronger bond between the release coating and the non-porous surface than exists between the release coating and the backing sheet. Once the adhesive cures, the backing sheet is peeled off the release coating and image material. The sheet photopolymer is then exposed to actinic radiation (without the need for vacuum) and processed normally.
[0013] In the third method of the invention, the backing sheet of the preliminary laminate need not be transparent. A clear release coating is applied to the backing sheet to form the preliminary laminate, and the image is printed (or stamped or drawn) on the release coating. A clear adhesive layer is spread on the non-porous surface, and the image side of the preliminary laminate is pressed into the adhesive to form a third laminate of the instant invention. The adhesive should be a fast self-curing resin that produces a stronger bond between the release coating and the non-porous surface than exists between the release coating and the backing sheet. After the adhesive cures, the backing sheet is peeled off, leaving the image on the non-porous surface.
BRIEF DESCRIPTION OF THE DRAWINGS
[0014] FIG. 1 depicts in cross-section a prior art method of making a flexographic printing plate from an image negative using a sheet photopolymer.
[0015] FIG. 2 is a magnified cross-sectional view of an analog photopolymer sheet exposed according to the prior art in FIG. 1 under a good vacuum.
[0016] FIG. 3 is a magnified cross-sectional view of a digital photopolymer sheet exposed according to other prior art.
[0017] FIG. 4 is a magnified cross-sectional view of a digital photopolymer sheet exposed according to other prior art under a good vacuum.
[0018] FIG. 5 is a magnified cross-sectional view of the preliminary laminate used in all three of the methods of the invention.
[0019] FIG. 6 is a magnified perspective view of the preliminary laminate being inkjet printed in accordance with the first method of the invention.
[0020] FIG. 7 shows in magnified cross-section the printed preliminary laminate being applied to a photopolymer sheet for production of a flexo plate in accordance with the first method of the invention to form the first embodiment laminate of the invention.
[0021] FIG. 8 shows in magnified cross-section the backing sheet being peeled off the unexposed sheet photopolymer in accordance with the first method of the invention.
[0022] FIG. 9 is a magnified cross-section of the preliminary laminate being applied to a digitally-imaged sheet photopolymer in accordance with the second method of the invention to form the second embodiment laminate of the invention.
[0023] FIG. 10 shows in magnified cross-section the photopolymer sheet prepared according to the first method of the invention being exposed to actinic radiation.
[0024] FIG. 11 is a magnified cross-sectional view of an analog photopolymer sheet exposed according to the first method of the invention.
[0025] FIG. 12 is a magnified cross-sectional view of a digital photopolymer sheet exposed according to the second method of the invention.
[0026] FIG. 13 depicts in magnified cross-section the finished flexo plate after removal of soluble materials in accordance with the first and second methods of the invention.
[0027] FIG. 14 depicts in magnified cross-section an example of the application of a printed preliminary laminate to transfer an inkjet image to glass in accordance with the third method of the invention.
[0028] FIG. 15 depicts in magnified cross-section removal of the backing sheet from the inkjet image on glass in accordance with the third method of the invention.
DETAILED DESCRIPTION OF THE INVENTION
[0029] Referring now to the drawings, which are not to scale, and in which like reference characters refer to like elements among the drawings, FIG. 1 depicts in magnified cross-section a prior art method of making a flexographic printing plate from a photographic film negative 1 and a so-called analog sheet photopolymer 2 . The film negative 1 consists of a plurality of black areas opaque to actinic radiation. Henceforth in this description, the actinic radiation will be exemplified by, and referred to as, UV (ultraviolet) light, and the sheet photopolymers mentioned will be of the types that are curable by UV light, but without the intention to limit the invention or its use to UV and photopolymers sensitive to UV.
[0030] Again referring to FIG. 1 , transparent areas 3 between the black areas in the film negative 1 allow UV light to pass through. Not uncommonly, a transparent area may be as small as a single dot in a halftone image, perhaps corresponding to a single pixel of a digital image or a single (missing) droplet from an inkjet printer. The sheet photopolymer 2 consists of a layer of photosensitive copolymer 4 bonded to a transparent polyester substrate 5 . The combination of film negative 1 and sheet photopolymer 2 is placed on a transparent bottom glass 6 in a special exposure machine, and a transparent vacuum sheet 7 is placed over the negative. A top glass 8 is then lowered down on top of the vacuum sheet 7 , and a vacuum is applied to entire sandwich by withdrawing air through a network of grooves 9 . Once the air is withdrawn to a hard vacuum, lower UV lights 10 are turned on for a length of time sufficient to cure a floor area 11 within the copolymer layer 4 of the desired thickness on top of the substrate 5 . The upper UV lights 12 are then turned on to shine through the transparent areas 3 in the image layer 1 . The lights are on for a length of time sufficient to expose areas within the remainder of the copolymer 4 and create a substantially vertical relief pattern 13 . The exposed sheet photopolymer 2 is then removed from the apparatus and developed into a flexo plate by known washing and/or scrubbing techniques to remove any unpolymerized photopolymer.
[0031] Making a flexo plate from CTP technology looks similar to FIG. 1 , with the exception that the opaque image is formed directly on the upper surface of the copolymer 4 , so the thin air space between the negative and the copolymer surface is eliminated. Nevertheless, some air will still exist between the vacuum sheet 7 and the copolymer surface depending on the intensity of the vacuum and how carefully the vacuum sheet is applied to eliminate air bubbles. Some water vapor bubbles may appear anyway if there is any moisture in the opaque image material.
[0032] FIG. 2 is a more highly magnified cross-sectional view of a portion of an analog photopolymer sheet 2 exposed and developed as described in FIG. 1 under a good vacuum as taught in the prior art. It shows a single relief dot 20 formed under a one pixel wide transparent area 3 in a film negative 1 . Even under good vacuum there will be some gas 21 (predominantly air) beneath the vacuum sheet 7 and underneath the negative 1 in contact with the surface 22 of the copolymer 4 . As a result, the shoulders 23 of the top 24 of the dot 20 are slightly rounded. This is believed to be caused by the presence of oxygen at the surface 22 interfering with crosslinking of the photopolymer. The printed image of this dot will not be sharp.
[0033] FIG. 3 is the same view of a relief dot 20 produced using a pre-imaged digital (CTP) photopolymer sheet 30 and no vacuum sheet. A digital photopolymer sheet 30 differs from an analog sheet 2 in that it has not only a clear substrate layer 5 and a photosensitive copolymer layer 4 , but also an opaque image layer 31 . The image layer 31 has been ablated with an IR laser to produce a clear etched area 32 through which UV light can pass to create a positive relief image in the flexo plate. Without any covering of the imaged sheet 30 , gas 21 in the form of oxygen in the ambient air can come into contact freely with the surface 22 of the copolymer 4 during UV exposure. The top 24 of the dot 20 is even more rounded than in FIG. 2 and may not even reach the surface 22 of the copolymer layer 4 . The printed image of this dot oftentimes appears as a tiny squiggle where the dot should be.
[0034] FIG. 4 is the same view of a relief dot 20 produced using a pre-imaged digital (CTP) photopolymer sheet 30 , but with most air excluded from the copolymer layer 4 through the use of a vacuum sheet 7 as known in the prior art. When the vacuum is applied prior to UV exposure, the sheet 7 is pulled down into the etched area 32 . In a manner similar to that shown in FIG. 2 , this greatly reduces, but does not eliminate, gas 21 from being present near the surface 22 of the copolymer 4 . Moreover, under high vacuum, any moisture in the image material 31 can evaporate and add to the gas 21 . The result is better than that shown in FIG. 3 but roughly the same as FIG. 2 .
[0035] FIG. 5 is a magnified cross-sectional view of the preliminary laminate 43 used in all three methods of the instant invention. The preliminary laminate consists of a backing sheet 41 coated with a release coating 42 . While the inventor has used polyester as a backing sheet in the practice of this invention, the backing sheet 41 may be any smooth, low-porosity material such as many other plastics including polystyrene. Low porosity is essential so that the release coating does not bond tightly to it. The release coating 42 must likewise be formulated not to bond with the backing sheet (for instance, not to soften or chemically etch the backing sheet polymer) but to adhere to it slightly until the backing sheet is ultimately peeled off as discussed further in detail below. The release coating 42 must be inkjet-receptive in the sense that ink droplets from an inkjet printer must adhere to it firmly, but dry on the surface without spreading. A suitable release coating practiced by the inventor is an inkjet-receptive emulsion with no binder additives such as an OSCC clear glossy inkjet-receptive coating. The method of coating the backing sheet 41 requires that the release coating 42 be thin and smooth, as can be produced by curtain coater, a Mayer rod applicator, or a slot-die applicator, to name a few. If the preliminary laminate is to be used to transfer images to a sheet photopolymer, then both layers must be transparent to whatever type of actinic radiation (typically UV) is needed to cause polymerization of the photopolymer.
[0036] FIG. 6 is a magnified perspective view of a portion of the preliminary laminate 43 being printed with a digital inkjet image 60 in accordance with the first method of the invention. An inkjet print head 61 (typified by that of a water-based piezoelectric printer used to print photopolymer sheets) is moving above and across the release coating 42 in the direction A. As it goes, droplets 62 of UV-opaque ink are discharged onto the release coating 42 according to a computer-generated pattern, forming the UV-opaque negative image 60 . The release coating 42 has the purpose of temporarily bonding the inkjet image 60 to the backing sheet 41 .
[0037] FIG. 7 shows in magnified cross-section the inkjet-printed preliminary laminate 43 from FIG. 6 being applied to an analog sheet photopolymer 2 to produce the first laminate of the invention. This first laminate is then used to produce a flexo plate in accordance with the first method of the invention. As in FIG. 1 , the analog sheet photopolymer 2 consists of a layer of photosensitive copolymer 4 bonded to a transparent polyester substrate 5 . An adhesive layer 70 is first applied to the surface of the copolymer layer 4 . The imaged preliminary laminate 43 is then inverted and pressed into the adhesive layer 70 to produce the first laminate of the invention (note that the backing sheet 41 is uppermost in this view). Importantly, again, the adhesive chosen must bond the inkjet image 60 to the copolymer 4 more tightly than the release coating 42 is bonded to the backing sheet 41 .
[0038] FIG. 8 shows in cross-section the backing sheet 41 being peeled off the unexposed analog sheet photopolymer 2 in accordance with the first method of the invention, leaving behind the release coating 42 , the image 60 , and the adhesive 70 . It is desirable to do this before the UV exposure because any gases that might be generated by the heating of the materials under the lights might otherwise be trapped under the backing sheet.
[0039] FIG. 9 is a magnified cross-section of the preliminary laminate 43 from FIG. 5 being applied to a digital (CTP) sheet photopolymer 30 in accordance with the second method of the invention. In this second method, no image is printed on the preliminary laminate 43 as in FIG. 6 . Rather, an opaque image 31 is created on the digital sheet photopolymer 30 by ablation of its image coating, or thermal layer, using an IR laser or similar method. Thus, this figure differs from FIG. 7 simply in that the image 31 , being part of the sheet photopolymer 30 , is in direct contact with the surface of the photosensitive copolymer 4 instead of the release coating 42 . So, while the role of the preliminary laminate 43 here does not include transferring the image, its critical role still is to provide an anaerobic and bubble-free condition at the uncoated surface of the photosensitive copolymer 4 .
[0040] FIG. 10 shows in magnified cross-section an analog photopolymer sheet as prepared in FIG. 8 being exposed to UV light in accordance with the first method of the invention. (This same procedure can be applied to the CTP photopolymer sheet sealed with the preliminary laminate as shown in FIG. 9 once the backing sheet 41 has been peeled off, in accordance with the second method of the invention.) The process is similar to, but simpler than, that shown in FIG. 1 . Here, the imaged sheet photopolymer 2 is placed on a transparent bottom glass 6 . Lower UV lights 10 are turned on for a length of time sufficient to cure a floor area 11 partway up within the photopolymer from the substrate 5 . The upper UV lights 12 are then turned on to shine through the transparent areas 3 in the image layer 1 . The lights are on for a length of time sufficient to expose areas within the remainder of the copolymer 4 and create the relief pattern 13 . The exposed sheet photopolymer 2 is then developed into a flexo plate by washing and/or scrubbing to remove any unpolymerized photopolymer. Hence it is not sufficient merely to provide an adhesive 70 that will bond the image 60 to the copolymer layer 4 more tightly than the release coating 42 bonds the image 60 to the backing sheet 41 . It is also necessary that the image 60 and the adhesive 70 be removable from the optically crosslinked portion of the copolymer layer 4 by the process normally used to develop a relief image. The typical process of solvent washing and scrubbing suitably removes the adhesive layer 70 , the image 60 and the release coating 42 along with the uncrosslinked photopolymer.
[0041] FIG. 11 is a magnified view of a relief dot 20 produced using the first laminate of the invention as shown in FIG. 7 and prepared in accordance with the first method of the invention. The release coating 42 and the layer of adhesive 70 keep air away from the surface 22 of the copolymer 4 . The top 24 of the dot 20 is formed all the way up to the edge 50 of the inkjet-printed area 60 and is therefore flat. The printed image of the dot will be sharp and round. Thus, this first laminate and first method of the invention produce flat top dots of a quality unique to current digital flexo printing plates. This dot shape enables printers to improve substantially their print quality and consistency and increases the print life of the plate, making flexo competitive with gravure and offset printing processes.
[0042] FIG. 12 is a highly magnified view of a relief dot 20 produced using the second laminate of the invention as shown in FIG. 9 according to the second method of the invention. The release coating 42 and the layer of adhesive 70 keep air away from the surface 22 of the copolymer 4 . However water vapor liberated from the image material 31 by heat from the exposure lamps (not shown) diffuses upward through the adhesive 70 and the release coating 42 and into the ambient air. The top 24 of the dot 20 is formed all the way up to the edge 50 of the etched area 32 and is therefore flat. The printed image of the dot will be sharp and round. The second laminate of the invention produces flat top dots of a quality unique to current digital flexo printing plates. This dot shape enables printers to improve substantially their print quality and consistency and increases the print life of the plate, making flexo competitive with gravure and offset printing processes.
[0043] FIG. 13 depicts in cross-section a portion of the finished flexo plate 130 after conventional washing and scrubbing, leaving the photopolymerized portions of the copolymer layer 4 supported by the substrate 5 . Note that because the laminates of the invention have isolated the photopolymer sheet from oxygen during curing, the relief dot 20 has sharp shoulders 23 .
[0044] In summary, the steps of the first method of the invention for making a flexo plate from an inkjet image are: (a) preparing a preliminary laminate by coating a flexible backing sheet with a release coating; (b) printing a mask image on the release coating; (c) coating the active surface of a photopolymer sheet with an adhesive; (d) rolling the image-bearing preliminary laminate onto the adhesive, image side down, so that there are no visible air bubbles under the image; (e) when the adhesive sets, peeling the backing sheet away from the release coating, leaving the release coating and the mask image adhesively bonded to the photopolymer sheet; (f) exposing the masked photopolymer to actinic radiation sufficient to produce the desired cured relief image; and (g) washing the mask image, adhesive, release coating and unexposed photopolymer off the photopolymer substrate and doing any other post-exposure processing as required. Step (c) may alternatively be coating the mask image with adhesive instead of the active surface of the photopolymer sheet. It is possible to get the same result, of course, by applying the adhesive to the image side of the preliminary laminate instead of the photopolymer sheet.
[0045] Because the image-bearing preliminary laminate used in the above method is adhesively bonded to the photopolymer, there are no air spaces such as would be attendant to the use of a film negative, and, so long as the preliminary laminate is carefully applied to the photopolymer sheet, there is no ambient air in contact with the photopolymer during curing (the process is anaerobic). Any water vapor given off by the image material will diffuse away from the photopolymer into the ambient air. It is therefore not necessary to put it and the photopolymer sheet under vacuum prior to exposure. This allows the use of a simpler, less expensive unit for the UV exposure and eliminates the steps of positioning a negative film, applying a vacuum sheet, creating a vacuum to remove gases, and removing the negative film after exposure of the photopolymer sheet.
[0046] The steps of the second method of the invention for making a flexo plate from a digital image are: (a) preparing a preliminary laminate by coating a flexible backing sheet with a release coating; (b) ablating a mask image into the thermal layer of a digital photopolymer sheet; (c) coating the imaged thermal layer with an adhesive; (d) rolling the preliminary laminate onto the adhesive so that there are no visible air bubbles under the image; (e) when the adhesive sets, peeling the backing sheet away from the release coating, leaving the release coating and the mask image bonded to the photopolymer sheet; (f) exposing the masked photopolymer to actinic radiation sufficient to produce the desired cured relief image; and (g) washing the mask image, adhesive, release coating and unexposed photopolymer off the photopolymer substrate and doing any other post-exposure processing as required. Step (c) may alternatively be coating the release coating with adhesive instead of the imaged thermal layer of the photopolymer sheet.
[0047] FIG. 14 depicts in magnified cross-section an example of the third method of the invention for applying an inkjet-printed preliminary laminate 43 from FIG. 6 to transfer its inkjet image 60 to a pane of glass 71 . First, an adhesive layer 70 is applied to the surface of the glass 71 (or the inkjet-printed surface of the preliminary laminate). The preliminary laminate with the image is then inverted and pressed into the adhesive layer 70 (note that the backing sheet 41 is uppermost in this view). Importantly, the adhesive chosen must bond the image to the glass more securely than the release coating 42 bonds to the backing sheet 41 . An example of an adhesive that works successfully to bond an image to glass, where the backing sheet of the preliminary laminate is polyester and the inkjet ink is water-based, is ethyl-cyanoacrylate glue (“superglue”). Ethyl-cyanoacrylate glue polymerizes very quickly, allowing enough time to coat the glass and seat the imaged preliminary laminate on it, without etching, dissolving or distorting the image. In the actual practice of transferring an image to glass, the choice of ink would likely be water-insoluble as most imaged glass surfaces are likely at least to come into contact with condensate from the atmosphere at some point in time.
[0048] FIG. 15 depicts in cross-section removal of the backing sheet 41 from the release coating 42 in accordance with the third method of the invention. The release coating 42 bonds to the backing sheet 41 with less peel strength than it bonds to the image 60 and adhesive 70 . Thus, once the adhesive 70 cures, the backing sheet 41 may be peeled off the release coating 42 as shown, leaving the image on the glass. Because the release coating is clear, it does not matter that it remains on the image. The aforementioned clear glossy inkjet-receptive coating produced by Ontario Specialty Coatings Corporation is water soluble, so that if the ink is insoluble, the release coating 42 may be wiped off with a damp cloth.
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Two methods using two respective laminates produce flexographic printing plates with flat top dots from sheet photopolymers. The methods use a preliminary laminate to isolate the photopolymer surface from the ambient air. A third method enables images to be transferred to non-porous surfaces.
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BACKGROUND OF THE INVENTION
The field of the present invention is that of turbomachines, more particularly that of turbomachine low-pressure turbine nozzles. It relates more precisely to a ceramic matrix composite (CMC) material turbine nozzle. CMC materials are typically formed of a fibrous reinforcement of refractory fibers, such as carbon or ceramic fibers, densified by a ceramic or at least partially ceramic matrix.
DESCRIPTION OF THE PRIOR ART
Modern turbomachines are conventionally produced in the form of an assembly of modules including either mobile parts or fixed parts. They comprise firstly, starting from the upstream end, one or more compressor modules disposed in series that compress air aspirated into an air inlet. The air is then introduced into a combustion chamber where it is mixed with a fuel and burned. The combustion gases pass through one or more turbine modules that drive the compressor or compressors. The gases are finally ejected either into a nozzle to produce a propulsion force or onto a free turbine to produce power that is recovered on a transmission shaft.
The turbomachine generally includes at the exit from the combustion chamber a set of fixed blades also known as a high-pressure turbine nozzle, enabling straightening of the flow of gases in the direction of a mobile high-pressure turbine wheel; it is generally followed, in the downstream direction, by a fixed low-pressure nozzle that straightens the flow at the exit from the high-pressure turbine toward a mobile low-pressure turbine wheel.
The low-pressure turbine nozzle blades are solid parts including an airfoil extending between a shroud and a root positioned at its upper and lower ends; they are generally provided with dedicated cooling, which is to the detriment of the energy balance of the engine. At present low-pressure nozzles are produced in metal alloys, which necessitates cooling them. For this purpose cooling air flows through them that is then directed toward turning parts cooling injectors. A high flow of air therefore passes through the nozzle, since it must enable both cooling of the nozzle and feeding of the injectors. The flow of cooling air degrades the performance of the engine since it is obtained to the detriment of the power delivered by the engine.
Improving performance and reducing polluting emissions leads moreover to envisaging ever higher combustion temperatures, imposing ever higher stresses on the hot portions of turbomachines, i.e. the parts situated downstream of the combustion chamber. It is then desirable to use CMC materials as much as possible for the fixed parts because of their very good thermal and structural properties. CMC parts have the advantage of combining beneficial mechanical properties, making them suitable for the production of structural elements, with that of retaining these mechanical properties at high temperatures.
To limit the impact on the low-pressure nozzles in terms of mass and flow of air, the use of CMC materials on the one hand enables the mass of the nozzle to be limited, because of their low density, and on the other hand their cooling to be eliminated or at least very greatly reduced, because of their good temperature resistance. However, integrating a CMC material is technologically difficult because it expands less than the metals around it.
CMC low-pressure nozzles have been designed, one example of which is given in patent application No. FR 1059315 in the name of the applicant. The corresponding device comprises CMC nozzle airfoils and a metal turbine internal casing, the two parts being attached to an external metal collar by means of a tube that has a function of guiding the flow cooling the internal casing in addition to this structural support function.
The drawbacks of this solution are, firstly, that too much of a structural function is imparted to the tube supplying the cooling air, which complicates its production, and, secondly, centering of the internal casing is poor because of the great length of this tube. It has therefore appeared beneficial to separate these two functions and for the cooling tube to retain only the function of supplying the internal casing with cooling air, the function of retaining the internal casing then being transferred to another part.
SUMMARY OF THE INVENTION
An object of the present invention is to remedy the drawbacks of the prior art devices by proposing a ceramic matrix composite material low-pressure turbine nozzle that necessitates no or little cooling flow and that is mechanically compatible with the metal parts around it.
To this end, the invention consists in a composite material turbine nozzle blade including an airfoil adapted to have a cooling fluid flow through it and extending between a shroud and a root, said shroud being shaped to be fixed to one or more turbine casings of a turbomachine and said root being shaped to provide a junction with a turbine internal casing so as to transfer said cooling fluid to said internal casing, wherein its root is produced with a loosened texture and includes, on the one hand, a loosened texture lug on the internal upstream side and a loosened texture lug on the internal downstream side, the two lugs on the internal side shaping the flow of gas and, on the other hand, a loosened texture lug on the external upstream side and a loosened texture lug on the external downstream side, the ends of the two lugs on the external side extending radially relative to the rotation axis of the turbomachine to form means for supporting and centering said internal casing.
The radial orientation of the external lower loosened texture lugs enables the internal casing to be allowed to expand in use by providing it with flanges that are also oriented radially. This ensures the compatibility of a CMC part like the low-pressure nozzle with a metallic internal casing.
The shroud is advantageously produced with a loosened texture and includes, on the one hand, a loosened texture lug on the internal upstream side and a loosened texture lug on the internal downstream side, the two lugs on the internal side shaping the gas stream and, on the other hand, a loosened texture lug on the external upstream side and a loosened texture lug on the external downstream side, the two external lugs being adapted to fix said blade to the structure of the turbomachine. The similar shapes of the root and the shroud facilitate their production.
In one particular embodiment the airfoil is hollow and the shroud and the root are pierced by a hole to provide a passage for a cooling tube intended to route cooling air to the internal casing.
The invention also relates to a turbine nozzle constituted by an assembly of blades as described hereinabove.
It relates further to an assembly constituted of a turbine nozzle as described hereinabove and a metallic turbine internal casing, said internal casing including two radially oriented flanges shaped to support it and to center it through cooperation with the external lower loosened texture lugs of the blades of said nozzle.
In such an assembly, the internal casing advantageously further includes a longitudinal extension shaped to form a radial abutment for one of the external lower lugs of at least one nozzle blade and to allow relative movement in the axial direction between the blade and the internal casing by virtue of their differential expansion.
The invention also relates to an assembly constituted of a turbine nozzle constituted by an assembly of blades as described above, a metallic turbine casing, said internal casing including two radially oriented flanges shaped to support and center it through cooperation with the external lower loosened texture lugs of the blades of said nozzle, and at least one cooling tube passing through said holes of a blade, the internal casing further including means for retaining said tube in the axial and circumferential directions and allowing a degree of freedom to said tube in translation in the radial direction.
In such an assembly, the internal casing advantageously further includes a longitudinal extension shaped to form a radial abutment for one of the external lower lugs of at least one nozzle blade and to allow relative movement in the axial direction between the blade and the internal casing by virtue of their differential expansion.
The invention relates finally to a turbomachine turbine module including an assembly as described hereinabove and to a turbomachine including such a module.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention will be better understood and other objects, details, features and advantages thereof will become more clearly apparent in the course of the following detailed explanatory description of one embodiment of the invention given by way of illustrative and nonlimiting example only with reference to the appended diagrammatic drawing.
In the drawing:
FIG. 1 is a general view in section of a turbine module showing a low-pressure nozzle in its environment, and
FIG. 2 is a view in section of a low-pressure turbine nozzle of one embodiment of the invention.
DESCRIPTION OF PREFERRED EMBODIMENTS
In the remainder of the description the terms axial and radial relate to the direction of the rotation axis of the turbomachine. For their part, the terms upstream and downstream refer to the direction of flow of the air or burned gases in the gas stream of this turbomachine, as represented by thick arrows in FIG. 1 . The terms upper and lower relate to the greater or lesser radial distance of the element concerned. Finally, the terms external and internal refer to a greater or lesser distance from the median axis of the gas stream.
Referring to FIG. 1 , there are seen the principal components of the hot parts of a turbomachine comprising a high-pressure turbine blade 1 and a low-pressure turbine blade 2 between which is a low-pressure turbine nozzle blade 3 . These hot parts also comprise a high-pressure turbine nozzle, not shown, upstream of the high-pressure blade 1 .
The low-pressure nozzle blade 3 is fixed by its upper part to structural parts referred to as the high-pressure turbine casing 6 and the low-pressure turbine casing 7 by means of hooks integrating in grooves provided for this purpose on said turbine casings. This nozzle blade is hollow to provide a passage for air necessary for cooling the low-pressure turbine internal casing and the high-pressure turbine mobile blades 1 and low-pressure turbine mobile blades 2 . Because of its CMC structure, it does not need cooling and therefore has no perforations on the surface of its airfoil, which is swept by the flow of hot gases of the turbomachine.
A cooling pipe 4 leading from an air bleed on the compressor is fixed facing the upper end of the nozzle to feed the various portions of the hot parts with cooling air. These parts include a turbine internal casing 5 the function of which is to fasten together the roots of the low-pressure nozzle blades 3 and to direct the cooling air toward the mobile turbine blades 1 and 2 . The cooling air therefore flows from the cooling pipe 4 via the interior of the airfoil of the turbine nozzle 3 toward the turbine internal casing 5 , which it cools, and is then divided to flow through the cooling internal cavities of the mobile blades 1 and 2 . It is then re-injected into the flow through the cooling orifices of those blades.
Referring now to FIG. 2 , there is seen a low-pressure turbine nozzle blade 3 including an airfoil 10 for straightening the flow of gas at the outlet from the high-pressure turbine blade wheel 1 before it enters the low-pressure turbine wheel 2 . This airfoil is extended in its upper portion by a shroud 11 and in its lower portion by a root 12 . The nozzle blade 3 is produced entirely from a CMC material and thus has no perforations on its airfoil 10 for evacuating the cooling air, the material used being sufficiently resistant to high temperatures and having no need to be swept by a cooling film. The shroud 11 and root 12 are also produced from a CMC material in one piece with the airfoil 10 , with a loosened texture on the upstream and downstream sides of the shroud or root. A loosened texture is characterized by a separation within its thickness of the layer of fibers forming the shroud or root to form two distinct layers, called loosened texture lugs, that diverge radially relative to each other whilst remaining connected by the ceramic matrix. The shroud and root thus have, both on their upstream side and on their downstream side, two loosened texture lugs, one reconstituting the flow of gas upstream or downstream of the airfoil 10 and the other serving either to attach the nozzle blade 3 to the turbine casings or to fix the internal casing 5 .
The shroud 11 is divided on the upstream side into two loosened texture lugs, an internal upper upstream lug 111 that forms the upper portion of the flow passage upstream of the airfoil 10 and an external upper upstream lug 112 that is engaged in a hook 61 carried by the high-pressure turbine casing 6 to support the nozzle blade 3 on the upstream side. In the downstream direction it is also divided into two loosened texture lugs, an internal upper downstream lug 113 that forms the upper portion of the flow passage downstream of the airfoil 10 and an external upper downstream portion 114 that is engaged in a hook 71 carried by the low-pressure turbine casing 7 to support the nozzle blade 3 on the downstream side.
In the same way, the root 12 is divided in the upstream direction into two loosened texture lugs, an internal lower upstream lug 121 that forms the lower portion of the flow passage upstream of the airfoil 10 and an external lower upstream lug 122 for centering and axial retention of the internal casing 5 on its upstream side through cooperation with the upstream flange 51 of that internal casing. On the downstream side it is also divided into two loosened texture lugs, an internal lower downstream lug 123 that forms the lower portion of the flow passage downstream of the airfoil 10 and an external lower downstream lug 124 that centers and axially retains the internal casing 5 on its downstream side through cooperation with the downstream flange 52 of this internal casing.
The upstream and downstream external loosened texture lugs enable, on the one hand, positioning of the low-pressure nozzle 3 in its engine environment by the upper lugs 112 and 114 , like the metallic nozzle hooks of the prior art, and, on the other hand, retention of the internal casing 5 in position relative to the low-pressure turbine nozzle by the lower lugs 122 and 124 .
The two external lower lugs 122 and 124 are bent and assume a radial direction where they are joined to the terminal flanges 51 and 52 of the internal casing 5 , which are also radially oriented, to enable sliding of this internal casing on the cylindrical walls formed by said external lower lugs. This configuration accommodates differences in radial expansion that exist between the CMC material low-pressure nozzle and the metallic internal casing 5 . The internal casing 5 also includes a longitudinal extension 50 extending in the axial direction along which the external lower lug 124 of the low-pressure nozzle blade 3 can slide for good retention of the internal casing 5 by the low-pressure nozzle 3 despite the different axial expansion of the two parts.
FIG. 2 also shows a cooling tube 8 that passes through the airfoil 10 of the nozzle 3 and conducts cooling air coming from the cooling pipe 4 toward the internal casing 5 and the cooling internal cavities of the mobile blades 1 and 2 . This air merely passes through the hollow airfoil 10 without escaping from the tube 8 or cooling the airfoil 10 , which is made of CMC to resist the temperature of the gas flow. The upper portion of this cooling tube 8 is supported by a metallic exterior collar 9 that is also supported by the hooks 61 and 71 of the high-pressure turbine casing 6 and the low-pressure turbine casing 7 . Its lower portion is simply retained slidably by an extension of the internal casing 5 in the form of a radially oriented chimney 53 . The tube 8 has enlargements at both ends, which imparts to it a so-called “dog's bone” shape, to facilitate retaining it in position. The external end 8 e is held by a circlip engaged in a groove produced for this purpose in the exterior collar 9 , whereas the internal end 8 i is merely guided radially by the chimney 53 of the internal casing, in which it is free to expand when it becomes hot. To this end a radial clearance delimited by a shoulder is provided in the chimney 53 to enable expansion of the tube 8 passing through the low-pressure nozzle blade 3 and the internal casing 5 .
How the parts of a turbine module including a CMC material low-pressure turbine nozzle conforming to the invention are structurally retained is described next.
The nozzle blade 3 is supported by its external upper loosened texture lugs 112 and 114 that are introduced into the hooks 6 and 7 of the high-pressure and low-pressure turbine casings. This being the case, the internal upper loosened texture lugs 111 and 113 are naturally positioned so as to assure the continuity of the gas stream between the outlet of the wheel of the high-pressure turbine 1 and the inlet of that of the low-pressure turbine 2 . Also engaged in these hooks is the exterior collar 9 that supports the cooling tube 8 . This exterior collar interlocks with the high-pressure turbine casing 6 , which prevents it rotating about the engine axis. An axial clearance is provided between the high-pressure turbine casing 6 and the assembly constituted by the external upper upstream loosened texture lug 112 and the upstream end of the metallic collar 9 , so as to enable differential expansion of the CMC material of the low-pressure nozzle and the metal of the exterior collar 9 under thermal load.
The cooling tube 8 is supported by the exterior collar 9 via its circlip and has no rigid connection in its lower portion to the internal casing 5 , which eliminates all structural action of this cooling tube. Its fixing to this exterior collar and its passage through holes produced in the shroud 11 of the nozzle 3 nevertheless provides the function of preventing rotation of the nozzle 3 around the axis of the turbomachine. This structural function imparted to the cooling tube 8 is limited, however, the point of application of the loads at the level of the holes in the shroud 11 being close to the point of attachment of the tube to the exterior collar.
The internal casing 5 is positioned and centered on the low-pressure nozzle with no intervention by the cooling tube 8 . The upstream and downstream external lower lugs 122 , 124 of the low-pressure nozzle blade 3 are respectively pressed onto the upstream and downstream flanges 51 , 52 of the internal casing 5 , which because of their radial orientation allow the metallic internal casing 5 to expand radially facing the CMC low-pressure nozzle. Moreover, the external lower downstream lug 124 of the low-pressure nozzle blade 3 is positioned radially against the longitudinal extension 50 of the internal casing 5 , which assures radial centering of the internal casing on the low-pressure nozzle and allows expansion of the internal casing caused by heating.
In the final analysis, the solution provided by the invention consists in imparting to the low-pressure nozzle a structural function relating to retention and centering of the internal casing 5 . The latter is thus retained axially and radially by the CMC low-pressure nozzle; it is also prevented from rotating about the engine axis by the exterior collar 9 via the cooling tube 8 .
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A composite material turbine nozzle blade including an airfoil adapted to have a cooling fluid flow through it and extending between a shroud and a root is provided. The shroud is shaped to be attached to one or more turbine casings of a turbomachine and the root is shaped to provide a junction with a turbine internal casing. The root is produced with a loosened texture and includes an external upstream side loosened texture lug and an external downstream side loosened texture lug. The ends of the two external side lugs extend radially relative to the rotation axis of the turbomachine to form a device for supporting and centering the internal casing.
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CROSS REFERENCE TO RELATED APPLICATION
This application is a continuation of U.S. application Ser. No. 11/284,379, filed Nov. 21, 2005, which is incorporated herein by reference.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to method of producing hydrofluorocarbons, and particularly lower alkyl hydrofluorocarbons, from hydrochlorocarbons.
2. Description of Related Art
It is known that when certain halocarbons are released into the atmosphere, they undergo reactions that result in the depletion of the Earth's ozone layer. Examples of environmentally harmful halocarbons include certain hydrochlorocarbons (HCCs), hydrochlorofluorocarbons (HCFCs), and chlorofluorocarbons (CFCs). One such CFC is trichlorofluoromethane (CFC-11), a compound that conventionally has been used in foam insulation applications. Due to CFC-11's potential for environmental damage, replacements for this compound have been sought. One proposed substitute for CFC-11 in foaming application is 1,1-dichloro-1-fluoroethane (HCFC-141b). Although HCFC-141b also adversely affects the ozone layer, its impact is significantly less than that of CFC-11.
Certain lower alkyl hydrofluorocarbons, including the compound 1,1,1,3,3-pentafluoropropane (HFC-245fa), have been identified as a potential replacements for HCFC-141b in a variety of applications, most notably insulation and refrigeration applications. HFC-245fa has good insulation characteristics, low toxicity, correct vapor pressure and low flammability properties. Accordingly the demand for HFC-245fa has grown and as well as a need for more economical means of producing compounds such as HFC-245fa.
Methods for producing hydrofluorocarbons (HFCs) by reacting hydrogen fluoride (HF) with various hydrochlorocarbon and/or hydrochlorofluorocarbon compounds are known. For example, various schemes for producing HFC-245fa from 1,1,1,3,3-pentachloropropane (HCC-240fa) or 1,3,3,3-tetrachloro-1-propene (HCC-1230) and hydrogen fluoride (HF) either in the liquid or vapor phase have been described. See, for example, U.S. Pat. Nos. 5,902,912 and 5,710,352. For liquid phase processes, a catalyst such as SbCl 5 or SbF 3 Cl 2 is usually required to promote the exchange of chlorine atoms on the organic reactant with fluorine atoms of the hydrogen fluoride reactant. Unfortunately, the reaction conditions (e.g. reactant and catalyst concentrations, temperatures, pressures and the need for oxidants such as chlorine to maintain catalyst activity) required to promote this halogen exchange process can be extremely corrosive to metals commonly used for liquid phase reactors, such as Monel, Inconel and Hastelloy C. As a result of the extremely corrosive reaction environment most reactors used for fluorination processes must be lined with fluoropolymers. However, these lined reactors suffer from poor heat transfer and HF permeation of the liner. In addition, the use of Cl 2 as an oxidant results in a yield loss due to chlorination of various raw materials, intermediates, and reactants.
SUMMARY OF THE INVENTION
Applicants have discovered advantageous methods for preparing alkyl hydrofluorocarbons, such as C2-C4 hydrofluorocarbons, and preferably HFC-245fa. In preferred embodiments the methods include liquid phase reactions which overcome many of the disadvantages of prior processes, including the many of the problems mentioned herein.
In one preferred aspect, applicants have discovered that HFC-245fa can be employed as a solvent for a superacid system in which HFC-245fa can also be prepared at commercially viable production rates and under conditions that are not corrosive to metals such as Hastelloy C. The preferred methods of the present invention utilize a reaction system (eg., reactants, solvent, acid, and catalyst) capable of achieving low to negligible corrosion rates with respect to certain metals and alloys, while also achieving productivities (defined as amount of product made per unit of time per unit volume of reaction mass) equal to or greater than systems which employ corrosive “conventional” halide exchange liquid phase reaction systems (e.g. high concentration SbCl 5 ). The preferred method and systems of the present invention can thus utilize reactors constructed with contact materials having greater heat transfer rates (eg., metals) as compared to fluoropolymer lined reactors which are necessitated by the highly corrosive conventional liquid phase reaction systems. In addition, the preferred aspects of the present invention can be in the form of continuous production methods and systems using equipment configurations similar to those currently employed in the production of other HCFC and HFC compounds such as chlorodifluoromethane (HCFC-22), 1,1-dichloro-1-fluoroethane (HCFC-141b), and 1,1,1-trifluoroethane (HCFC-143a).
According to preferred aspects of the present invention, at least one non-fluorinated hydrochlorocarbon, such as HCC-240fa and/or HCC-1230, is added to a solution comprising: (a) a solvent (preferably C2-C4 hydrofluorocarbon solvent, more preferably C3 hydrofluorocarbon solvent, and even more preferably HFC-245fa solvent); (b) a fluorinating agent (such as HF); and (c) a fluorination catalyst, such as a metal pentafluoride under conditions effective to produce the desired C2-C4 hydrofluorocarbon reaction product, preferably HFC-245fa.
Although not wanting to be bound to any particular theory, it is thought that when a fluorinating agent, particularly HF, reacts in the presence of metal halide catalyst, such as SbF 5 , TaF 5 , and NbF 5 , an exothermic reaction occurs to form a superacid system. It is believed that this reaction may occur according to the following reaction scheme:
2 HF+MF 5 →[H 2 F] (+) [MF 6 ] (−)
The higher Lewis acidity of super-acids such as anhydrous hexafluoroantiminic acid (HSbF 6 ), anhydrous hexafluorotantalic acid (HTaF 6 ), or anhydrous hexafluoroniobic acid (HNbF 6 ) relative to conventional acid catalysts such as “HSbCl 5 F” and “HSbF 4 Cl 2 ” (as measured by the Hammet scale) allow for lower concentrations of catalyst to be employed while still achieving similar productivity. In addition, the reaction mechanism may be different than the “Swarts” reaction based systems which are presumably dominant under conditions of high SbCl 5 concentration and low HF concentration. Moreover, compared to conventional acid catalysts, fully fluorinated superacids require much less, if any, oxidants (such as chlorine) to maintain their activity, thus further lowering yield losses due to the presence of Cl 2 in the reaction system and further lowering the corrosive tendency of the reaction system. The corrosion of reactors which use lower concentrations of fully fluorinated superacid catalyst is considerably less compared to conventional high SbCl 5 concentration system. The latter has been demonstrated to be very corrosive to metals such as Hastelloy C and Monel 400. Also, the low catalyst concentration system of certain preferred aspects of the present invention has other benefits, such as the low viscosity and the presence of only one liquid phase in the reactor.
One preferred aspect of the present invention provides methods of producing C2-C4 hydrofluorcarbons, preferably 1,1,1,3,3-pentafluoropropane, comprising: (a) providing a solution comprising a metal halide fluorination catalyst at least partially dissolved in an azeotrope-like mixture of 1,1,1,3,3-pentafluoropropane and hydrogen fluoride; and (b) adding to the solution at least one non-fluorinated HCC to form a liquid reaction system under conditions effective to convert at least a portion, and preferably a substantial portion, of said non-fluorinated HCC (preferably by reaction of said HCC with said HF) to the desired C2-C4 hydrofluorcarbon, preferably 1,1,1,3,3-pentafluoropropane.
In certain preferred embodiments, the present invention provides a continuous process for the preparation of HFC-245fa which comprises continuously introducing a stream comprising C3 hydrochlorocarbon, preferably 1,1,1,3,3-pentachloropropane, 1,3,3,3-tetrachloro-1-propene or combinations of these into a reactor containing a solution of HFC-245fa, HF, and a metal halide fluorination catalyst selected from the group consisting of SbF 5 , NbF 5 , TaF 5 and mixtures of TaF 5 and SnF 4 under conditions which produce HFC-245fa. Preferably the process also includes the step of introducing anhydrous hydrogen fluoride into said reaction system.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 depicts a schematic representation of an embodiment of the present invention wherein a desired HFC (such as HFC-245fa) is produced via a continuous process.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
Preferred aspects of the present invention provide for the catalytic, liquid phase fluorination of at least one non-fluorinated hydrochlorocarbon, such as HCC-240fa, HCC-1230, or a mixture of HCC-240fa and HCC-1230, with HF, wherein the reaction product and the solvent for the reaction are both HFC-245fa. In certain embodiments of the invention, a solution of HFC-245fa, HF and catalyst is first prepared in a fluorination reactor. The reactor according to such preferred aspects of the invention may be any suitable fluorination reaction pressure vessel or autoclave which is constructed from materials that are resistant to the corrosive effects of hydrogen fluoride at the temperatures and pressures of the reaction, such as Hastelloy C, Monel, Inconel, Molybdenum or fluoropolymer lined steel. After this solution is prepared and the reactor is brought to the desired temperature and pressure, the hydrochlorocarbon and HF are fed into the reactor, preferably substantially simultaneously.
Preferred liquid phase metal halide catalysts for this reaction are SbF 5 , NbF 5 , TaF 5 , mixtures of TaF 5 and SnF 4 , and some combination thereof. At the preferred concentrations and temperatures employed in this reaction, the HFC-245fa, HF, and catalyst are preferably completely, or at least mostly, miscible. The exothermic reaction between the HF and metal halide preferably occurs to form a superacid, presumably according to the following scheme:
2 HF+MF 5 →[H 2 F] (+) [MF 6 ] (−)
The reaction mixture is then preferably brought to reaction temperature and pressure conditions such that the HF/HFC-245fa azeotrope-like composition is formed, and preferably begins to reflux.
As used herein the term “azeotrope-like” refers, in a broad sense, to compositions that are strictly azeotropic and compositions that behave like azeotropic mixtures. From fundamental principles, the thermodynamic state of & fluid is defined by pressure, temperature, liquid composition, and vapor composition. An azeotropic mixture is a system of two or more components in which the liquid composition and vapor composition are equal at the state pressure and temperature. In practice, this means that the components of an azeotropic mixture are constant boiling and cannot be separated during a phase change.
Thus, “azeotrope-like” compositions are constant boiling or essentially constant boiling. In other words, for azeotrope-like compositions, the composition of the vapor formed during boiling or evaporation is identical, or substantially identical, to the original liquid composition. Thus, with boiling or evaporation, the liquid composition changes, if at all, only to a minimal or negligible extent. This is to be contrasted with non-azeotrope-like compositions in which, during boiling or evaporation, the liquid composition changes to a substantial degree.
Another characteristic of azotrope-like compositions is that there is a range of compositions containing the same components in varying proportions that are azeotrope-like or constant boiling. All such compositions are intended to be covered by the terms “azeotrope-like” and “constant boiling”. For example, it is well known that at differing pressures, the composition of a given azeotrope will vary at least slightly, as does the boiling point of the composition. Thus, an azeotrope of A and B represents a unique type of relationship, but with a variable composition depending on temperature and/or pressure. It follows that, for azeotrope-like compositions, there is a range of compositions containing the same components in varying proportions that are azeotrope-like. All such compositions are intended to be covered by the term azeotrope-like as used herein.
The reactor in accordance with preferred aspects of the present invention is preferably maintained at a temperature of from about 60° C. to 120° C., more preferably from about 70° C. to 110° C., and even more preferably from about 80° C. to 100° C. The reactor pressure is preferentially maintained at the vapor pressure of the HF/HFC-245fa azeotrope-like composition, which is largely determined by the temperature of the reactor system as well as its composition. The HF/HFC-245fa azeotrope-like vapor pressure characteristics and compositions are described in U.S. Pat. No. 6,001,796, which is incorporated herein by reference.
Preferred non-fluorinated hydrochlorocarbons include, HCC-240fa, HCC-1230, and combinations thereof. Without being bound by or to any particular theory of operation, it is believed that when these reactants are used the overall net reactions are as follows:
HCC-240fa CCl 3 —CH 2 —CH 2 Cl+5 HF→CF 3 —CH 2 —CF 2 H+5HCl
HCC-1230 CCl 3 —CH═CHCl+5 HF→CF 3 —CH 2 —CF 2 H+4HCl
During the latter parts of the reactions, it is believed that certain volatile intermediates are formed which can be separated from the reaction product and returned back to the reactor in order to be converted into the HFC-245fa product, which has a boiling point of 15° C. at 1 atmosphere of pressure. These intermediates include, but are not limited to, the following compounds:
1,3,3,3-tetrfluoro-1-chloropropane (HCFC-244) nbp=39° C.
3,3,3-trifluoro-1-chloropropene (HCFC-1233) nbp=21° C.
1,3,3,3-tetrafluoro-1-propene (HFC-1234) nbp=−19° C.
The preferred net molar feed ratio of HF to HCC (preferably HCC-240, HCC-1230, or some combination thereof) is from about 3:1 to about 8:1, more preferably from about 4:1 to about 6:1, and even more preferably in certain embodiments about 5:1. Since some HF may be lost from the reaction system via carryover with the HCl byproduct, this loss is preferably compensated for by raising the feed ratio accordingly. A significantly higher ratio could result in the gradual accumulation of HF in the reactor, while a significantly lower net ratio could result in the gradual depletion of HF in the reactor. Of course, the exact amount of HF in the feed can be controlled by monitoring the amount of HF in the reaction product in accordance with known techniques.
Preferably, the mole ratio of HF to HCC-230 and/or HCC-1230 in the reaction system is greater than about 10:1. The mole ratio of HF:HFC-245fa in the reactor is preferably not more than about 12:1, more preferably not more than about 8:1, and most preferably about 6:1.
The amount of catalyst in the reactor can vary within the broad scope of the present invention depending upon numerous factors, including the trade-off between increased production and the potential increase in corrosion. The amount of catalyst preferably ranges from about 0.5 wt % to about 10 wt % of the starting mixture, more preferably from about 1 wt % to about 5 wt % and most preferably from about 2 wt % to about 4 wt %. The molar ratio of HF to catalyst initially present and prior to the HCC addition is preferably at least about 10:1, more preferably at least about 20:1, and even more preferably at least about 40:1. The amount of HFC-245fa solvent present in the reaction mixture at steady state preferably ranges from about 40 to about 80 wt %, more preferably from about 45 to about 70 wt %, and even more preferably from about 50 to about 60 wt %.
In certain preferred embodiments, the solvent is put into the reaction vessel at startup and preferably maintained within acceptable levels, which in preferred embodiments is substantially constant amount, by removal of HFC-245fa as it is generated. Due to the azeotrope-like composition formed by HF and the product/solvent, any HF lost is preferably replaced by additional HF input. This loss can arise when a portion of the HF/HFC-245fa azeotrope-like composition is removed from the reactor so that at least a part of the HFC-245fa can be separated as a product. Any suitable means can be used to separate HFC-245fa from the azeotrope-like composition, including the extraction of HF from the azeotrope-like composition by concentrated sulfuric acid. HFC-245fa has very limited miscibility in H 2 SO 4 relative to HF, and the resulting HF—H 2 SO 4 solution can be heated to distill off the HF, which can then be returned to the reactor as a recycle stream.
The preferred feed rate of HCC-240fa or HCC-1230 ranges from about 0.1 to about 10 lbs/gallon-hour based upon the total volume of liquids in the reactor. A more preferred range is from about 1 to about 5 lbs/gallon-hour, while the most preferred range is from about 2 to about 4 lbs/gallon-hour.
In certain preferred embodiments, the unreacted hydrochlorocarbons, such as HCC-230, and partially fluorinated intermediates are volatilized from the liquid reaction mixture, along with HF and the HF/HFC-245fa azeotrope-like composition, and then recycled back to the to the reactor for further fluorination. In general, almost all of the intermediates are less volatile than the product, and therefore this recycle of higher boiling materials (with the exception of HFC-1234) is easily effected by fractional distillation techniques well known to those skilled in the art.
This continuous production process can utilize several features of existing liquid phase HF reaction processes, including a pressure reactor connected to a continuous fractional distillation column or series of columns. FIG. 1 depicts one preferred embodiment of this invention wherein a reactor is maintained at a constant level and composition by feeding HF, chlorinated feed and recycled organics into the reaction vessel R-1 at a rate that the chlorinated materials will be converted into the desired product, such as the preferred HFC-245fa. In addition to the HF and organic feeds, small amounts of desiccants, such as SOCl 2 , COCl 2 or COF 2 may be added in order to remove any trace amounts of water that would enter the reaction system. For example, HF may contain 500 ppm H 2 O, which, over time, can accumulate in the reboiler if not removed (e.g. by a reaction that consumes the water molecules). The vapor outputs from the reactor, consisting mostly of HCl, the HF/HFC-245fa azeotrope-like composition, and various smaller amounts of intermediates and feedstock, are preferably directed to a fractional distillation column T-1, where most of the higher boiling compounds are condensed/refluxed back to the reactor. The vapor stream leaving the partial condenser of T-1 is then preferably fed to another column T-2, under conditions so that the by-product HCl is refluxed and vented off for either collection or neutralization. The higher boiling materials from the reboiler of column T-2 can then be fed to another column T-3, wherein the remaining trace intermediates, such as HFC-1234, are preferably distilled-off and recycled back to the reactor, while higher boiling compounds that accumulate are preferably then fed to column T-4. In this T-4 distillation column, when present, the HFC-245fa/HF azeotrope-like composition (which generally comprises from about 22 wt % HF/88 wt % HFC-245fa) is preferably distilled off and transferred to the HF extraction unit while the accumulated higher boiling compounds such as HCFC-244 and HCFC-1233 are fed back to the reactor, preferably at rates equal to their accumulation. The HF/HFC-245fa vapor stream leaving the top of T-4 (via the partial condenser) is then preferably fed to an HF extraction column, where the HF present in the vapor azeotrope-like composition is extracted by a fluid such as sulfuric acid or fluorosulfonic acid. The crude HFC-245fa is then collected and, if desired, further purified to yield the desired product.
In many preferred embodiments it is highly desired that the catalyst and the HCC material(s) not be allowed to contact each other except in the presence of a molar excess of HF in order to inhibit or substantially prevent catalyst deactivation. Such a deactivation may occur by a process known as the Swarts reaction, resulting in a chlorinated metal halide that possesses a significantly lower (Lewis) acidity, as measured via the Hammet scale. An example of the undesired Swarts reaction would be as follows:
CCl 3 —CH 2 —CHCl 2 +SbF 5 →CF 3 —CH 2 —CCl 2 H+SbF 3 Cl 2
In contrast, the preferred reaction mechanism according to the present invention is believed to be represented as follows:
R—Cl+[H 2 F][SbF 6 ][R (+) ][SbF 6 ] (−) +HCl+HF
[R (+) ][SbF 6 ] (−) +2HF→R—F+[H 2 F][SbF 6 ]
The HCl byproduct is preferentially vented off from the system and either condensed with a low temperature coolant in a second distillation system, or neutralized with an appropriate base such as NaOH or CaCO 3 . If the HCl by-product is to be neutralized, the high pressure gas (at a range of 100 to 300 psig) can be used as a source of refrigeration as it is expanded from the cold high pressure state to atmospheric pressure. This would reduce the energy consumption of the process, as there is a considerable amount of HCl made from the conversion of HCC-240 into HFC-245fa (1.36 lbs HCl/lb HFC-245fa).
The present mechanism differs from the Swarts reaction, even though the end result is similar. The Swarts reaction, which can take place even in the absence of HF, occurs as follows:
R
-
C
l
+
SbF
(
5
-
x
)
C
l
(
x
)
→
[
R
(
+
)
]
[
SbF
(
5
-
x
)
Cl
(
x
+
1
)
(
-
)
]
→
R
-
F
+
SbF
(
4
-
x
)
Cl
(
x
+
1
)
x
=
0
,
1
,
2
,
3
or
4
In practice, the Swarts catalyst can be regenerated with HF:
Sb (4−x) Cl (x+1) +HF→SbF (5−x) Cl (x) +HCl
The by-product HCl formed, is easily distilled away from the re-generated Swarts catalyst due to its low boiling point (nbp=−83° C.) versus the normal boiling point of HF (nbp=+20° C.). This catalyst can also decompose into the +3 valency by eliminating Cl 2 ; for example:
SbF 3 Cl 2 →SbF 3 +Cl 2
This is a temperature related equilibrium reaction (increasing dramatically as the temperature rises from 75° C.) that needs to be reversed by the addition of Cl 2 into the reaction system. The Sb +3 halides are ineffective as halogen exchange catalysts with HCCs/HFCs.
According to certain preferred embodiments, the reaction process has a first step wherein a carefully maintained ratio of HF to HCC (such as HCC-240fa, HCC-1234 or combinations of these) is fed into a reactor after a HFC-245fa/HF/catalyst system is refluxing at the correct temperature and pressure, for example in column T-1. As the system approaches steady state, recycled organic feeds and recycled HF can be sent back to the reactor; as this occurs, the HF:organic feed ratio can be trimmed back to a mole ratio of about 5:1. This method is preferred because the vapor exiting the initial column would contain HCl, HFC-245fa, and HF in a molar ratio of approximately 5:1:1.68, and thus depleting the HF in the reactor, leading to the possibility of increased corrosion as the net molar ratio of catalyst to HF increases towards undesirable levels.
Since both the HF and organic feed might contain a small but significant amount of water (500 ppm with the HF, <50 ppm for the organic), a dehydrating agent such as SOCl 2 or COF 2 can be added in small amounts depending upon the amount of water present in these feeds. Water may act as a base in the system, decreasing the acidity of the system as measured on the Hammet scale. Since CO 2 and HCl have very similar vapor pressures, the use of dehydrating agents that also produce CO 2 are preferred because the CO 2 can then be easily vented off from the system along with the HCl at the top of column T-2.
The liquid accumulated in the reboiler of column T-2 is then be sent to column T-3, where the small amounts of more volatile organic intermediates can be separated from the HFC-245fa and HF. The HF/HFC-245fa enriched mixture that accumulates in the reboiler of column T-3 is then be sent to column T-4, where the HF/HFC-245fa is distilled away from higher boiling intermediates such as HCFC-244 and these higher boiling compounds are then sent back to the reactor at a rate equal to their accumulation in the reboiler.
The HF/HFC-245fa azeotrope-like composition can exit from the top of column T-4 and be vented into the HF extraction unit. The purified vapor leaving the top of this extraction column (the extraction column where concentrated H 2 SO 4 is added in a counter-current fashion) is then be condensed and accumulated prior to any further purification steps—for example the removal of trace HF and trace amounts of unsaturated compounds, such as CF 3 —CH═CClH and CF 3 —CH═CFH. The resulting sulfuric acid-HF-fluorosulfonic acid solution leaving the bottom of the extraction column is then sent to a reboiler where the majority of the HF would be fractionally distilled away from the H 2 SO 4 —HSO 3 F solution. The HF distillate can be condensed and recycled back to the HCFC synthesis reactor, while the HF depleted hot H 2 SO 4 solution can be sent back to the extraction column T-4 after being cooled. The small amount of HFC-245fa and volatile unsaturated compounds contained in the distilled HF can also be included in this recycle stream. At this point, an HFC-245fa product having a purity at least about 99% is achievable.
EXAMPLES
The following non-limiting examples serve to illustrate certain aspects of the invention.
Example 1
Into a stirred 600 ml Hastelloy C autoclave was added 7.0 gram (0.032 gram-mole) of SbF 5 and 56.7 grams anhydrous HF (2.84 gram-moles). Next, 85.9 grams of HFC-245fa (0.642 mole) was added, followed by 48.5 grams (0.224 mole) of HCC-240fa. The mixture was then pressurized with N 2 to 170 psig, and then heated to about 120° C. over a 1 hour period and maintained at this temperature for an additional 2.5 hours. The bulk of the reaction took place in 34 minutes, as indicated by the amount of HCl byproduct vented from the system. The starting mole ratio of HF to HFC-245fa to SbF 5 was 88:19.8:1. Due to the evolution of HCl, the pressure rose significantly above the HF/HFC-245fa autogeneous pressure, and gas from the autoclave at a pressure greater than 400 psig was vented through a KOH scrubber/dryer and into a liquid nitrogen chilled collection cylinder over a 34 minute period. In this acid removing scrubber, a considerable amount of the product underwent a dehydrohalogenation reaction (forming the HFC-1234). The gas evolution ceased after the first hour, and was bled to atmospheric pressure at the end of the experiment. A total of 106.4 grams of organic was collected in the receiver with the following composition: 85.7% HFC-245fa, 9.4% HFC-1234, 2.52% HCFC-1233 and 1.48% HCFC-244 (the latter 3 compounds are intermediates in the synthesis of HFC-245fa). The net yield of product and formation of HFC-1234 byproduct, based upon the HCC-240 consumed, was 42.4% and 42.4%, respectively. There was no visible corrosion observed in this reaction, where the maximum temperature was 121° C. (560 psig. The net substitution of fluorine for chlorine on the organic feed was 98.1%. The reactor productivity was 2.5 lbs HFC-245fa/gallon-hr and 2.15 lbs HFC-1234/gallon-hr. When the HFC-245fa and HFC-1234 are treated as all HFC-245fa (HFC-245fa+KOH→HFC-1234+KF+H 2 O), the productivity would be near 5 lbs/gallon-hour.
Comparative Example 2
This example demonstrates the corrosion rate of a SbCl 5 /HF system on equipment that can be used to produce HFC-245fa. Into a stirred Hastelloy C autoclave was added 299 parts SbCl 5 (1 mole) and 60 parts HF (3 mole). The mixture was heated to 80° C. for 4 hours in preparation for the addition of HCC-240fa and Cl 2 , when HF was observed to be leaking from the autoclave. The corrosion rate was approximately 0.06 inches/hour on the baffle/thermowell, and even greater on the agitator blades, where the fluid velocities were greatest.
Example 3
A corrosion study was performed on an HF/SbF 5 /HFC-245fa system at 90° C. upon various metals and alloys. Using a solution of 5 wt % SbF 5 , 47.7 wt % HF and 47.3 wt % HFC-245fa, the corrosion rate for Hastelloy C, Inconel 600, Incoloy 825, Monel 400, SS 316 and C1018 carbon steel. The results of this example are provided in Table 1.
TABLE 1
Materials of Construction
Corrosion Rate (mils/year)
Hastelloy C
0
Inconel 600
27
Incoloy 825
9
Monel 400
30
SS 316
21
C1018 carbon steel
96
Having thus described a few particular embodiments of the invention, various alterations, modifications, and improvements will readily occur to those skilled in the art. Such alterations, modifications, and improvements, as are made obvious by this disclosure, are intended to be part of this description though not expressly stated herein, and are intended to be within the spirit and scope of the invention. Accordingly, the foregoing description is by way of example only, and not limiting. The invention is limited only as defined in the following claims and equivalents thereto.
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A process for the production of C2-C4 hydrofluorocarbon, such as 1,1,1,3,3-pentafluoropropane, by contacting a non-fluorinated hydrochlorocarbon with a fluorinating agent, such as hydrogen fluoride, in a liquid catalyst system preferably comprising fluorinated superacid catalyst prepared from SbF 5 , NbF 5 , TaF 5 or TaF 5 /SnF 4 and HF.
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This application claims the benefit under 35 U.S.C. §119(e) of United States Provisional application Ser. No. 60/038,301, filed Feb. 21, 1997.
BACKGROUND OF THE INVENTION
This invention relates generally to dogging devices and more particularly to dogging devices used with panic exit and actuator assemblies.
The dogging function of an exit device on a door secures the active bar of the exit device in the depressed position with the device latching bolt retracted. Activating a dogging device is accomplished by depressing the active bar and rotating a hex wrench clockwise through a hole adjacent to the bar. This action will hold the depressed bar and retracted latch until the dogging function is deactivated. Another method to activate the dogging device is cylinder dogging where the hex wrench is replaced with a locking cylinder. In the dogged state, egress may be gained by pulling from the outside of the door or pushing from the inside. A dogged device now permits heavy traffic to egress from the previously locked exterior without the actuation of levers, knobs or key cylinders. Dogging devices in high traffic applications will reduce the potential for wear by disabling all moving parts.
Current dogging devices require disassembly to convert the dogging device from a hex shaft to a locking cylinder. It is possible to assemble the dogging device incorrectly, which can render the dogging device inoperable.
The foregoing illustrates limitations known to exist in present dogging devices. Thus, it is apparent that it would be advantageous to provide an alternative directed to overcoming one or more of the limitations set forth above. Accordingly, a suitable alternative is provided including features more fully disclosed hereinafter.
SUMMARY OF THE INVENTION
In one aspect of the present invention, this is accomplished by providing a dogging device for a latch assembly having a translating latching and unlatching control rod, comprising: a dogging hook having a hook portion thereon, the dogging hook being pivotable about an axis between a first position engaging the latching and unlatching control rod and a second position not engaging the latching and unlatching control rod; an operator co-axial with the dogging hook axis and engaging the dogging hook; a spring biasing the dogging hook in either of the first or Second positions; and a clip means for axially retaining the operator and the dogging hook.
The foregoing and other aspects will become apparent from the following detailed description of the invention when considered in conjunction with the accompanying drawing figures.
BRIEF DESCRIPTION OF THE DRAWING FIGURES
FIG. 1 is a partial perspective of a typical exit device showing the dogging device of the present invention;
FIG. 2 is a perspective view of the dogging device shown in FIG. 1;
FIG. 3 is an exploded perspective view of the dogging device shown in FIG. 2;
FIG. 3A is a cross-sectional view of a dogging adapter;
FIG. 4 is a plan view of the dogging device shown in FIG. 2;
FIG. 5 is side view of the dogging device shown in FIG. 2;
FIG. 6 is a perspective view of a cylinder adapter for use with the dogging device shown in FIG. 2; and
FIG. 7 is a perspective view of the dogging device shown in FIG. 2 with the cylinder adapter shown in FIG. 6 in place of a hex operator shaft.
DETAILED DESCRIPTION
FIG. 1 shows a perspective view of a dogging device 10 for use with a latch assembly 12. The dogging device 10 has a dogging hook 20 which is rotatable between an engaging position where the dogging hook 20 engages a laterally moveable latching and unlatching control rod 14 on the latching assembly. When in the engaging position, the engagement of the dogging hook 20 holds the control rod 14 in position which in turn holds the active bar (not shown) of the latch assembly 12 depressed and the latching bolt (not shown) of the latch assembly retracted, i.e., "dogged".
The dogging device 10 includes the dogging hook 20, which has a hook portion 22 for engaging the control rod 14, an aperture 24 with an engaging keyway 26 for keyed engagement with a dogging adapter 70. The dogging adapter 70 consists of a cylindrical body 71 having an axially extending opening 72 therein. In the preferred embodiment, the axial opening 72 is hex-sided as shown in the FIGURES. The dogging adapter 70 has a shoulder portion 73 at its base for engaging the lower surface of a dogging plate 80. The dogging adapter 70 further has an axially extending key 74 on the outside of the cylindrical body 71. A U-shaped spring or clip 50 inserts into the dogging adapter 70. The U-shaped spring 50 engages the dogging hook 20 and an operator 30, 60. The U-shaped spring 50 axially retains the dogging hook 20, the dogging adapter 70 and the operator 30, 60. An over center spring 40 biases the dogging hook 20 in either of the engaged or disengaged positions.
In one embodiment, the operator 30, 60 is a hex shaft 30. The hex shaft 30 is chamfered at the base for easy insertion over the U-shaped spring clip 50. The hex shaft 30 has a groove 32 for engagement by the U-shaped spring clip 50. An internal hex in the top of the shaft accepts a 5/32 Allen wrench.
In a second embodiment, the operator 30, 60 is a cylinder adapter 60. The cylinder adapter 60 consists of a plate 62 having central aperture 66 with a pair of opposed notches 68 extending from the aperture 66 and a keyway 69 also extending from the aperture 66. The keyway 69 mates with the dogging adapter key 74. The notches 68 allow the cylinder adapter 60 to snap into position by engaging the free ends of the U-shaped spring clip 50. The cylinder adapter has two upstanding arms 64, which engage a rotatable tongue (not shown) of a locking and unlocking device (not shown).
The dogging plate 80 is the base of the dogging device 10. The dogging plate 80 has an aperture 82 through which the dogging adapter 70 and U-shaped spring clip 50 are inserted. Extending from the dogging plate aperture 82 is a limiting keyway 89 which interacts with the dogging adapter key 74 to limit the rotation of the dogging adapter 70 and attached dogging hook 20. One end of the dogging plate 80 has a first upturned portion 84 with cutout 88 for attachment of one end of spring 40. The other end of the dogging plate 80 has a second upturned portion 86 with forked section or guides 87 to restrain the side to side movement of the control rod 14 during engagement. An embossed section 83, the depressed portion, helps prevent installing spring 40 upside down. Cutout 88 is shaped with an approximate hourglass shape, i.e., a circular portion connected to a transversely extending approximately rectangular portion, to simplify installation of the spring 40 and retain a loop end 44 of the spring 40.
The spring 40 is an over center spring formed from a compression spring. Load is transferred across the spring 40 from the last coil at the looped end 44 against the dogging plate 80 and through the coils to the wire form end 42. The wire formed end 42 has an extension from the coils to provide clearance for the operation of the dogging hook 20. After this extension, a vertical form in the wire form end 42 is used to transfer the load to the dogging hook 20. The small bend at the end of the wire form end 42 prevents the spring 40 from disengaging from the dogging hook 20. The opposite end of the spring 40 contains a long loop, which serves as a handle for installation as well as a positioning aid. Because the load of the spring 40 is highest when the dogging hook 20 is in the center of its travel, the dogging hook 20 in unstable, which results in the spring 40 biasing the dogging hook 20 in either of the engaged or disengaged positions.
The dogging hook 20 has a center aperture 24 with an engaging keyway 26 extending therefrom. The combination of keyway 26, the shape of the dogging hook 20 and the dogging adapter key 74 only allows the dogging hook 20 to be assembled onto the dogging adapter 70 in one way, thereby preventing incorrect assembly. Because the control rod 14 may have several operating positions, the hook portion 22 is contoured to form one or more steps which allow the dogging hook 20 to engage control rod 14 in a plurality of positions.
The U-shaped spring clip 50 contains bends at the free ends of the spring 50 that form retaining heads 52. These retaining heads 52 cause the U-shaped spring clip 50 to retain itself in the dogging adapter 70 after the spring 50 is installed into the dogging adapter 70. The curvature at the top of the retaining heads 52 allow for easy insertion of the dogging hook 20 and the hex shaft 30. The flats, approximately right angle surfaces at the bottom the retaining heads 52, make these parts more difficult to remove. The bottom of the U-shaped spring clip 50 has a widened base portion 56 which abuts the underside of the dogging adapter 70 to prevent the spring clip 50 from being pushed completely through the dogging adapter axial opening 72. Each retaining head 52 has a small notch 54 that interacts with the cylinder adapter notches 68 retaining the cylinder adapter 60 on the dogging adapter 70.
The U-shaped spring clip 50 is inserted through the bottom of the dogging adapter 70 and snaps into two opposed slots or grooves 75 on the inside of the dogging adapter axial opening 72. The retaining heads 52 fit into two dogging adapter notches 76 at the upper ends of grooves 75 (FIG. 3A). With the U-shaped spring clip 50 in place, the dogging plate 80 is placed over the spring clip retaining heads 52 and onto the shoulder 73 of the dogging adapter 70. When the dogging hook 20 is placed over the dogging adapter 70, the U-shaped spring clip 50 will snap back, thereby axially securing all three components, dogging hook 20, dogging adapter 70, and spring clip 50. The hex shaped hole 72 in the center of the dogging adapter 70 accepts the hex shaft 30.
The dogging device 10 allows for easy field conversion from hex dogging (FIGS. 1 through 5) to cylinder dogging (FIGS. 6 and 7). First, remove the latch assembly 14 endcap and coverplate (not shown) and pull the hex shaft 30 straight out. Take a cylinder adapter 60 and press over the U-shaped spring clip 50. Because of the cylinder adapter keyway 69 and the cylinder adapter upstanding arms 64, the cylinder adapter 60 can only be installed one way. The endcap is the replaced along with a coverplate having a locking and unlocking device installed in the coverplate.
To operate the dogging device 10 having a hex shaft 30 installed, first, the latching assembly 12 is operated to depress the active bar (not shown) and retract latching bolt (not shown) and to move the control rod 14 towards the dogging device 10. Then, a hex Allen wrench through a hole in the latch assembly 12 coverplate and into the hex shaped hole in the hex shaft 30. The Allen wrench is rotated, causing the hex shaft 30 rotate, thereby rotating the dogging hook 20 from a disengaged position to an engaged position where the hook portion 22 of the dogging hook 20 engages the control rod 14. After the Allen wrench is removed, the over center spring 40 will bias (or keep) the dogging hook 20 in the engaged position where the dogging hook 20 will prevent the control rod 14 from disengaging from the dogging device 10 and thereby keep the active bar depressed and the latching bolt retracted, i.e., dogging the latching device 12 in an open condition.
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A dogging device for securing a panic exit and actuation device in an unlatched condition. The dogging device uses a U-shaped spring clip to secure a base plate, a dogging adapter and a dogging hook together. The base plate, dogging adapter and dogging hook are rotated about a common axis by an operator, which can either be a hex shaft or a cylinder adapter operated by a keyed lock, from a disengaged position to an engaged position where the dogging hook engages a control rod of the exit device thereby holding, or dogging, the exit device in an unlatched condition. An over center spring is used to bias the dogging hook into either the engaged or the disengaged position.
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BACKGROUND OF THE INVENTION
This invention relates to knitting machines for producing knitted articles incorporating warp yarns and possibly also weft yarns. The invention is applicable to both flat bed and circular knitting machines.
SUMMARY OF THE INVENTION
According to the present invention there is provided in a knitting machine means defining a needle bed, combined needles and jacks movable in the bed, sinkers arranged to co-operate with the needles, means defining guides for knitting yarn, and means defining guides for weft yarn, the improvement wherein there is provided means defining an additional bed, a pair of yarn supply members slidably mounted on the additional bed and interdigitated with respect to a contiguous pair of needles, yarn guides mounted on the yarn supply members so arranged that the guides can move to the front of the needles, wedge means mounted on the additional bed for resiliently diverging the individual members of each pair of yarn supply members, and control means for controlling operation of said wedge means according to a required program.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention will now be described, by way of example, with reference to the accompanying diagrammatic drawings, in which:
FIG. 1 is a fragmentary front elevation of the needle bed corresponding to two feeds (for a circular machine this view can be considered as a developed view of a portion of the needle cylinder);
FIG. 2 is a local section on line II--II of FIG. 1;
FIG. 3 is a plan as viewed from line III--III of FIG. 1;
FIG. 4 is a section similar to that of FIG. 2 but showing further details, the section being taken on the line IV--IV of FIG. 7;
FIGS. 5 and 6 are respectively an axial view and a plan view of the ends of a sinker, as viewed from lines V--V and VI--VI of FIG. 4;
FIG. 7 is a plan view of FIG. 4;
FIGS. 8 and 9; 10 and 11; 12 and 13; 14 and 15 respectively illustrate in cross-section and in plan view, limited to a pair of yarn supply members, different positions of various elements of the machine to form an interlaced knit fabric;
FIGS. 16, 17, 18 and 19 illustrate a first knit fabric produced on a machine in accordance with the invention in the two views, namely front and back of the fabric and in the sections on the lines XVIII--XVIII of FIG. 16 and XIX--XIX of FIG. 17;
FIGS. 20 and 21 show another form of knit fabric, respectively from the back and the front;
FIGS. 22, 23, 24 and 25 illustrate the front and back views and also two sections of a further knit fabric; and
FIGS. 26, 27 and 28 illustrate additional knit fabrics which can be obtained by a knitting machine in accordance with the invention.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring to the drawings and in particular to FIGS. 1 to 15, the knitting machine includes a needle carrying-bed and needles 4 slidable therein. The bed may be either flat or cylindrical, and in the latter event the views shown can be considered as developments of the needle cylinder. To control the needles, butts 6 of the needles co-operate with raising cam profiles 8 (FIG. 1) and with lowering cam profiles 10 and 12. In addition the needles can be operated by underlying jacks 14, provided with butts of several types and with different arrangements to co-operate with cams 16 to effect the desired needle selections, according to criteria known per se. These selections can be effected by several cams, with several rows of butts on the jacks and with butts having an appropriate distribution in the various rows. For those skilled in the art, an indication of the desired way of selecting the needles, is sufficient to establish the actually required arrangement of the insertion and disengagement controls of the cams, to obtain the desired selection with the aid of the jacks.
Between one needle 4 and the next, a sinker 18 is provided having a tip 18A (FIGS. 4 and 12) arranged to act on the fed yarns and a butt 18B which co-operates with cam profiles 20A, 20B, shaped as seen in FIG. 7 with inclined control cam profile 20C for moving the sinkers away from the needles and profile 20E for the interdigitation of the tip of each sinker between the needles.
Yarn-guides 22 and 24 are arranged successively in the direction of relative movement of the needles, each corresponding to one of the profiles 20C and 20E. The yarn-guides 22 feed yarn M1 for binding plain knitting while the yarn-guide 24 feeds a weft yarn T0, which is thicker. Additional yarn-guides are provided, for an overall or partial utilization, in pairs for each needle, and each is arranged in a fixed position with respect to the needles, to feed warp or vertical weft yarns, indicated by TV1 and TV2.
An additional front or bed 26 is provided lying normally to the bed 1 and spaced therefrom so that between the two beds, fabric can pass (see FIG. 4).
In the front or bed 26, provided with grooves substantially corresponding to the sinkers 18, a total of three movable members is provided. In the bottom section of each groove a slide member 28 can slide, including a wedge 28A at the end thereof next the needle bed, and including a control butt 28B on the opposite end. The tip of the wedge 28A is directed towards the butt 28B, that is on the opposite side of the needle bed.
Above the wedge member 28 in each groove left and right hand yarn supply members 30S and 30D are mounted. These supply members 30S and 30D are symmetrical with respect to a common plane, one being on the left and the other on the right. Each member 30 has a control butt; the butts 32X of alternate pairs of supply members 30 are aligned according to a different alignment from that of butts 32Y of the other pairs of supply members 30, so that the butts 32X (even number location) substantially cooperate with a profiled channel 34X and the butts 32Y (odd number location) co-operate with a profiled channel 34Y. Each of the two channels 34X and 34Y may have ramps to advance the members 30 such as 36Y and 38Y of the channel 34 (the latter ramp being formed by a cam 40Y).
In FIG. 7 the channel 34X is assumed to be rectilinear and the channel 34Y is provided with ramps to advance the members 30 and with corresponding retracting ramps 42Y and 44Y. The channels 34Y, 34X, and the channel 46 for the butts 28B may be formed above the front or bed 26 by members indicated in the drawing (FIG. 7) by C10, C11, C12 and C13.
The yarn supply member 30S and 30D corresponding to one of their upwardly directed deviations have fins 48 outwardly-diverging to form a V-shaped seat arranged to co-operate with the respective wedge 28A. Towards the end, each yarn supply member 30 has a hook extension 50 functioning as a yarn-guide, and is slightly bent away from the plane of the member. Each yarn supply member terminates moreover in a downwardly extending extension 52, having an inclination away from the plane of the member and is provided with eyelets 54 for the passage of the yarn TV2, TV1 respectively.
The operation of the assemblies 28, 30S and 30D, when actuated by the respective butts sliding in the channels 46, 34X and 34Y is as follows:
Under starting conditions (see FIGS. 8 and 9) the yarn supply members 30S and 30D are located in a retracted position that is, they lie to the rear of the row of needles 4. The wedges 28A are located in the bed and slightly spaced from the fins 48. The yarn supply members, owing to their own elasticity contact one another at the roots of the extensions 52, and divergence of these extensions is due only to their relaxed condition. Under these conditions a pair of yarn supply members can be advanced by means of the ramps 36Y and 38Y of the channel 34Y, or of the corresponding ramps of the channel 34X, and almost simultaneously or in advance also the slide member 28 and thus the wedge 28A are caused to advance. Under these conditions, the extensions 52 still adjacent one another at their roots, advance to the front of the row of needles (see FIGS. 10 and 11) passing between one needle and the next, that is between the needles indicated by 4S and 4D in FIGS. 11, 13 and 15. By the action of the return ramp of the channel 46, the wedge 28A is then retracted and in this way, acting on the fins 48, causes resilient divergence of the projecting portions of the yarn supply members 30S and 30D, as shown in FIGS. 12 and 13. The extensions 52 are thereby moved outside the needles 4S, 4D, considered as a pair, and thus the outside of the gap formed by the needles.
In the meanwhile, according to a selection desired, the needles can be raised completely or partially and thus in the embodiment illustrated, both the needles 4S and 4D, or only one thereof may have been raised, this depending upon the article to be produced. In the diverged configuration of the yarn supply members they may be retracted with the extensions 52 on the outside of the pair of needles 4S and 4D, by means of the ramps 42Y or 44Y, while simultaneously the wedge 28A is retracted by the corresponding ramp of the channel 46. Consequently, a yarn TV1 and/or TV2, which is carried by the members 50, 54 of a yarn supply member 30S or 30D, is brought in close proximity to the needle which has been raised, such as the needle 4S of FIGS. 12 to 15, above the latch of the raised needles. The yarns TV1 and/or TV2 remain engaged by the needles (even if the latter come down and then go up without being cleared), while these needles all take up a knitting yarn such as M1. The needles, in particular, may be relevelled and again raised in order that all take up the knitting yarn M1.
Restriction of the yarn supply members 30S and 30D, besides the stopping of the wedge 28A, determines the mutual resumption of the rest condition in which the members lie close to one another.
An operation of advance, diverging and retraction and thus of return of the yarn supply members 30S and 30D to their rest condition can be accomplished by alternate pairs in front of the several yarn feeds, with selection possibilities afforded by the channels 34X and 34Y, while the control of the wedge 28A can be repeated for all the pairs of carrier members, being inactive if not accompanied by the described movement of the yarn supply members of the respective pair. In fact the return to the rest condition of the yarn supply means takes place when the latter fully retract subsequently to the withdrawal of the wedge, whereby the wedge loses the contact with the fins which still have to complete retraction.
It will be apparent that the deposit of a yarn TV1 or TV2 in front of the respective needle can be selected both as a function of the raising or of the missed raising of the corresponding needle, and as a function of the advance or missed advance of the supply member or better of the pair of corresponding supply members, still as a function of the presence or absence of the yarn in the yarn engaging elements 50 and 54 of the supply member considered. With these selections it is possible to obtain different distribution conditions of the warp (or vertical weft) yarns TV1, TV2, to obtain articles with different interlacings (or patterns) as hereinafter indicated.
In order to better appreciate the formation of an interlacing, FIG. 7 is to be considered, in which a portion of the machine is shown, in which two consecutive feeds are provided. At the zone PX, the needles 4 are still low and the stitch is cleared; the sinker 18 is at its retracted position, while the yarn supply members are in the advanced stage (according to this embodiment, by the action of the ramp 36Y formed by the profiles C12 and C13), also the wedge 28, 28A being caused to advance by the ramp of the channel 46 formed by the profiles C10 and C11.
In the zone PY, the sinker 18 has advanced by the action of the ramp 20E (formed by the profiles C14 and C15) and has located the weft yarn T0 (supplied by the yarn-guide 24) behind the needles (also see FIG. 4), the needles still being low. The yarn supply members 30S and 30D have already been advanced with the extensions 52 in front of the needles and are about to be diverged. It is to be noted that the control of the yarn supply members 30S and 30D is operated according to alternate pairs and thus one pair remains retracted and the other one is caused to advance by the ramp 36Y.
In the passage from the zone PY to the zone PZ, the needles have been raised and the weft yarn PO is kept by the sinkers 18 behind the needles, while after raising of the needles (raising is selected by the controls operated for example by the jacks 14) the retraction of wedge 28A is initiated, and the wedge diverges the extensions 52, acting on the fins 48 of the advanced pair of yarn supply members. In this manner, the yarns TV1 and/or TV2 which are carried by the extensions 52, are wound in front of the needles and on the latches of the raised needles.
In the zone PW, the previously advanced supply members 30S and 30D are retracted and are closed, that is are brought towards one another behind the needles, so that the yarns TV1 and/or TV2, which have been engaged by respective selectively raised needles remain engaged by the needles hooks, clearing the loop of the stitch and the knot formed by the warp yarns TV1 and/or TV2. Before the lowering of the needles or in a subsequent stage by the action of a fresh raising of the needles, the knitting yarn M1 is fed, which is fed in every case when all the needles have been raised, apart the previous solution, in order to form with the yarn M1 a plain stitch.
As already stated previously, different fabrics are obtained through the selection possibilities afforded by the jacks 14, through the control arrangements of the yarn supply members 30S and 30D, through the arrangement of the yarns TV1 and TV2 (for example, on all the pairs, on one pair and one not, on member 30S and not on member 30D, or on member 30D and not member 30S, or on a right-hand supply member of a pair and on the left-hand one of the adjacent ones) and through possible additional conditions, for example also of selection or not of the needles to keep the weft T0 in certain zones in front of the needles rather than behind them.
One example of a knit fabric produced is illustrated in FIGS. 16 to 19, which respectively illustrate the front and the back and lateral views of the fabric. The yarns TV1 and TV2 are supplied to all the pairs of the supply members, which however at each feed cause one pair to advance and the next one to remain retracted, and exchange at the subsequent feed (in a feed, the even number pairs and in the subsequent, the odd number pairs); in this manner all the needles have two yarns TV1 and TV2 crossed and alternated one with respect to the other, for one course of stitches.
In FIGS. 20 and 21, which respectively illustrate the front and the back of another knit fabric, the supply members are fed with the yarns TV1 and TV2, one pair being fed and the other one not being fed, and the needles are selected a top one and a bottom one, always offset one with respect to the other from one course of stitches to the next.
In FIGS. 22 to 25 which respectively illustrate the front and the back and lateral views of another knit fabric, in each pair of supply members 30S and 30D, there is a single yarn TV1 which feeds the only supplier 30D and the needles are selected, a top one and a bottom one, alternate and always offset one from the other in each course of stitches or loops. In an alternative, the supply member 30S with the yarn TV2 may be used.
In FIG. 26 a portion of an article is illustrated which is produced by means of the following working steps. A feed is arranged for the formation of a course formed by a thick thread M2, a top needle and two low ones with the same arrangement as in the forming of plain stitch. At the contiguous feed, the subsequent course is formed by the selection of two top needles and a low one, which take up the yarn M1 from the yarn-guide G1. At the contiguous feed there is formed a third course by means of the arrangement of a top needle and two low ones, fed by the supply member 30D with the yarn TV1 or indifferently by the supply member 30S with the yarn TV2. At the still contiguous feed the subsequent course is set up by the selection of two top needles and a low one, which pick up the yarn M1 from the yarn-guide G1. By repeating the above indicated steps, the knit fabric shown in FIG. 26 is produced.
In FIGS. 27 and 28 there are shown further variations of the knit fabric including the possibility of producing without the introduction of the yarn M1, but of only yarns M2 and of warp yarns TV3 such as those indicated by TV1 or TV2.
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A flat bed or circular knitting machine has an additional bed which accommodates in grooves or tricks pairs of yarn-guide members which are controlled alternatively by cams to co-operate with needles of the machine. The ends of each yarn-guide member carries a hook which co-operates with an eyelet to effect the actual guiding function.
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STATEMENT OF GOVERNMENT INTEREST
The invention described herein may be manufactured and used by or for the Government of the United States of America for governmental purposes without the payment of any royalties thereon or therefor.
CROSS REFERENCE TO RELATED PATENT APPLICATIONS
This patent application is co-pending with four related patent applications entitled Early Commit Timestamp Computer Database Protocol, Ser. No. 08/238,033; U.S. Pat. No. 5,530,851; Early Commit Optimistic Projection-Based Computer Database Protocol, Ser. No. 08/238,036; U.S. Pat. No. 5,561,794; Merge, Commit Recovery Protocol for Real-time Database Management Systems, Ser. No. 08/236,900; U.S. Pat. No. 5,497,487; and Replay Recovery Protocol for Real-time Database Management Systems, Ser. No. 08/238,034; U.S. Pat. No. 5,524,239; all by the same inventor and filed on the same date as subject patent application.
BACKGROUND OF THE INVENTION
(1) Field of the Invention
The present invention relates to a computer database method for providing an early database commit while increasing database concurrency and limiting cascading aborts to minimize the impact on recovery for a decomposed database and transaction system.
(2) Description of the Prior Art
Real-time command, control and communications (C 3 ) systems control physical systems by extracting data from sensors, processing the extracted data, and performing control actions based on this processed data. Real-time C 3 systems are applied to applications where timeliness of data access, data processing and reactive responses are critical to the applications successful operations.
Real-time C 3 systems are being applied to a wide variety of physical systems, such as automotive control, aircraft control, spacecraft control, power management, automated factories, medical assistance and defense oriented systems. The main function of real-time C 3 systems is to manage and utilize information to control the real world environment. Therefore, these systems can be viewed as large information management systems that must respond in predictable ways and within specified time frames.
Real-time C 3 systems differ from conventional, general purpose systems in the sense that consistency and correctness of the real-time systems operation is dependent on the timeliness and predictability of responses to the controlled processes activities. In a real-time C 3 system, information is repeatedly collected from the physical system. Collected information is sampled, converted, formatted, timestamped and inserted into the control computer's database for each sampling period of the systems sensors. Stored data must be provided to the control software and system operators to be acted on to produce some desired control action.
Once the data is inserted into the database, it is used to compute a variety of related parameters. For example, raw sensor inputs from a radar system can be read and reduced to a bearing, range, and speed. These data items in turn can be used to compute detailed tracks of contacts, allowing for long-term tracking of an object. In addition, the raw information can be used to compute a profile on an object being tracked. This makes possible the classification and identification of an observed object. Transactions written to accomplish these computations require predictable and correct access, but not necessarily serializable access.
Real-time computing systems are being applied to a greater variety of control applications that require timely information.
Researchers are looking towards real-time computer systems as an emerging and important discipline in computer science and engineering. The real-time systems are characterized as possessing time dependent operations, reliable hardware and software, synergy with the controlled environment, predictable service. Predictability should be maintained not only in task scheduling, but also in scheduling all assets such as input/output, processing, communications, storage, and specialized controllers.
Databases within real-time systems must satisfy not only database consistency constraints but also timing constraints associated with transactions.
Responsive real-time databases must be predictable yet timely in their service. Real-time databases must incorporate features from real-time operating systems schedulers. A means to select the most appropriate database action to perform is necessary, and the scheduler must be adaptive to an ever changing real-time systems state. For correct database operations, real-time schedulers must be integrated with high performance concurrency control algorithms.
Recovery techniques based on rollback are not adequate in a real-time environment nor are present concurrency control techniques based on locking due to added blocking delays. Transactions must use non-serializable techniques, embedded transaction semantic knowledge, decomposition of transactions and the database to form more concurrent executions.
Transactions represent the unit of work recognized by users as being atomic. "Atomic" meaning that the operation or operations must be complete execution or be aborted all together. Transactions serve the dual purpose as the unit for concurrency and recovery in database systems. Concurrency provides for indivisible access to data objects by concurrently executing users; and recovery provides for data restoration due to hardware, software, and transaction failures.
Due to these properties researchers look towards the use of transactions as a tool for structuring computations in distributed systems.
Research into transaction decomposition is relatively new; however, researches have studied breaking transactions into nested elementary transactions to increase concurrency. One approach to this is to decompose transactions into disjointed operations separated by breakpoints which breakpoints define allowable interleaving to allow increased concurrency. Another approach is to decompose transactions into data flow graphs of transaction computations steps which can be optimized to increase performance.
The data itself can also be decomposed into atomic data sets (ADS) to allow a more concurrent execution of decomposed transaction steps. Many researchers indicate that a finer granularity on data objects can increase data concurrency if managed properly. Availability and timeliness of data and processing has been pointed out as being a desirable feature in real-time database management systems and may be more important that consistency. Thus, the cited research indicates using transaction decomposition, database decomposition, and parallel and concurrent execution of database actions to provide for increased performance.
Concurrency control is used to ensure database consistency while allowing a set of transactions to execute concurrently. The problem solved by concurrency control is to allow non-interfering readers and writers free access, while controlling and coordinating the actions of conflicting readers and writers. There are three basic concurrency control approaches for transaction processing in database systems: locking, timestamp ordering and optimistic. The basic concurrency control techniques rely on syntactic information to make concurrency control decisions. The correctness of the algorithms is based on serializability theory.
These concurrency control techniques are inherently pessimistic. They avoid conflicts by enforcing serialization of conflicting database actions. Prior art literature points out that serializability as a correctness criteria is to stiff a requirement for real-time systems. Real-time concurrency control algorithms, must integrate real-time scheduling algorithms with concurrency control techniques.
Semantic information about transactions can be used to develop non-serializable scheduling of transaction steps that nonetheless are correct executions. A prior art method using this breaks transactions into a collection of disjoint classes. Transactions that belong to the same class are compatible allowing for arbitrary interleaving, whereas transactions that belong to different classes are incompatible and cannot interleave. Another prior art method defines a scheme wherein the transaction writing system decomposes transactions into steps upon which concurrency control can be performed. Transactions are broken at breakpoints, and type classes defined on the breakpoints. Transactions of compatible classes can interleave at this point, others cannot. A further refinement of this technique is achieved by using a larger volume of transaction class types which results in a finer granularity of breakpoints. This system increases concurrency by adopting a looser definition of correctness than serializability.
Other prior art research suggests the use of decomposition of both transactions and the database into finer granules to increase concurrency. In this theory the database and transactions are decomposed into atomic data sets (ADS) and elementary transactions respectively. Elementary transactions are executed concurrently on distributed assets of an ADS. This theory suggests that if elementary transactions are serialized with respect to an ADS then correct and consistent database executions result.
The aforementioned schemes do not address the issues in management of real-time data which are driven by the needs of the overall system, based on criticality of operations, nature of deadlines, and timing requirements. This paper develops and presents transaction concurrency control algorithms for real-time systems, based on decomposition of both the database and individual transactions, along with the application of criticalness, deadlines, and timing requirements to improve real-time database systems performance and predictability.
SUMMARY OF THE INVENTION
Accordingly, it is a general purpose and object of the present invention to provide a method for operation of a real-time database system.
It is a further object that such real-time database system provide a high degree of concurrency.
Another object is that such system avoid transaction errors when possible and provide recovery when forced to abort an operation.
These objects are accomplished with the present invention by providing a computer database method wherein the data is organized into atomic data sets and transactions are separated into projections which operate on only one atomic data set. Multiple transactions can thereby access the same atomic data set using a locking protocol wherein locks are held by each projection. On access to a data item, the system detects existing locks. If locks are not found, the system locks the data and performs the access. When existing locks are found the system delays execution of the command and determines if a deadlock is present. To recover from a deadlock, related projections are merged together and reexecuted. The system merges related projections from other transactions and reexecutes if the deadlock continues. When the deadlock continues after execution of the above steps, a victim projection is chosen and aborted. The victim projection is restarted after commit of the conflicting projection.
BRIEF DESCRIPTION OF THE DRAWINGS
A more complete understanding of the invention and many of the attendant advantages thereto will be readily appreciated as the same becomes better understood by reference to the following detailed description when considered in conjunction with the accompanying drawings wherein:
FIG. 1 shows an example of a transaction before it is broken into projections;
FIG. 2 shows an example of a transaction that is broken into projections;
FIG. 3 shows pseudocode for a transaction having multiple projections;
FIG. 4 shows a flow chart of the command execution process of the early commit locking protocol of the current invention; and
FIG. 5 shows an example transaction and a waits-for graph for that transaction.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Database systems manage formatted collections of shared data. The database consists of collections of data fields, which are the finest granularity of data units available for users to manipulate. A data field is a basic data type such as name, age, address, etc. These basic data fields are organized into data items. Data items are the units for managing concurrency. Data items are not nested inside each other. Data items can be in the form of conventional records or objects. In this application the terms "item" and "record" are used interchangeably.
Relationships in the form of mathematical predicates are defined over items of the database. These predicates restrict the altering of database data items and structures. Database consistency means that all constraints are true. Constraints have the general form of predicates on database items. Constraints between data items of the database describe how database structures and items can be manipulated.
Constraints on database items are used to decompose the database into atomic data sets (ADSs). The database is a set of data items. Let i 1 , i 2 be two distinct items from the set of database items. Let constraint, C(i 1 , i 2 ), hold if there is a constraint that refers to i 1 and i 2 . Let C' denote the transitive and reflexive closure of C. The closure of constraints forms equivalence relations. The equivalence relations induced by C' are called atomic data sets (ADSs). Consistency is maintained on each ADS in isolation from other ADSs.
Transactions define logical units of work on the database. Transactions have a lower bound (begin transaction, BT) and an upper bound (end transaction, ET) defining boundaries for transaction management. Between boundaries, transactions enclose operations on the database of the form: read a data item x, r(x) or write a data item x, w(x), and transaction code.
For example, consider the transaction of FIG. 1. Let v 1 , v 2 , v 3 , and v 4 be variables of transaction T. Let a,b,c, and d be data items from an ADS. Execution of statement S 6 : w(d, V 4 ) causes the variable V 4 to be written to the data item d. Statement S 1 : v 1 :=r(a) represents a read from data item a into variable v 1 . The reading of a data item into a variable defines the variables value. Statement S 5 is an assignment statement. Assignment statements use variables to define new or existing variables. Statements of this type are of the form v 0 :=f(vlist) where vlist represents a set of variables used in computing v 0 and f is a function performed over vlist. S 5 applies function f i using variables v 1 , v 2 , and v 3 to define variable v 4 .
The conventional transaction model is extended to include boundaries on atomic data set accesses. These boundaries are formed on the initiation of access and termination of access to an atomic data set. The first request is preceded by a subbegin marker (sb) indicating the lower bound of access by this transaction on a named ADS. Terminate can be either a subabort (sa) or subcommit (sc) operation indicating the upper bound of access by this transaction on a named ADS.
A transaction accessing an ADS A, acquires resources in A as needed and releases resources once the last access to ADS A is performed. Transaction writers define when the first access to ADS A occurs and when the last access is performed. Boundaries for projections are formed using subbegin and subterminate statements.
After the last access to ADS A, a transaction cannot acquire more data items from ADS A. In this fashion the access and manipulation of ADS A, between the initial request for access until the final access forms a projection upon which concurrency control can be enforced. A projection π A (i) contains all accesses to ADS A from transaction T i and none from any other transaction.
An example of projections from a transaction is shown in FIG. 2. In this example A and B are individual ADSs. Let a, b, and c be items from these ADS A, and d be an item from ADS B. Access to items in ADS A are bound in between sb(A) and sc(A), or sa(A), and, likewise, accesses to ADS B are bound between sb(B) and sc(B), or sa(B). A statement that reads a data item defines the variable the data item is read into. A read statement is in the projection controlling access to the data item read.
In the example of FIG. 2, statements S 1 , S 2 , S 3 define local variables v 1 , v 2 , and v 3 by reading ADS A data items a, b, and c into these variables. Statements S 1 , S 2 , and S 3 are in projection π A since variables v 1 , v 2 , and v 3 are defined by reading data items from ADS A. Statement S 5 defines variable v 4 by reading data item d from ADS B into v 4 . Statement S 5 is in π B by reading a data item from ADS B.
A statement that writes a data item defines the data item. A write statement is in the projection controlling access to the data item written. In the example of FIG. 2 statement S 6 defines data item d of ADS B when it performs the write operation w(d, v 4 ) ; therefore, statement S 6 is in projection π B .
A statement, S directly depends on a statement S' if S follows S' and S uses at least one variable defined by S'. In the example of FIG. 2, assignment statement S 5 defines variable V 4 by performing a function f on variables in projection π A . Since statement S 5 uses variables from statements S 1 , S 2 and S 3 , S 5 directly depends on S 1 , S 2 and S 3 .
A statement S depends on a statement S' if S directly depends on S', or there is a statement S* such that S directly depends on S* and S* depends on S'. In the example of FIG. 2, write statement S 8 writes data item d using variable v 4 . Variable v 4 was defined in S 5 , therefore S 8 depends on S 5 . In addition since S 5 directly depends on S 1 , S 2 and S 3 , S 8 depends on S 1 , S 2 and S 3 .
A projection accesses data items outside of its boundaries by using statements in siblings. A projection π that uses statements that are in or depend on a sibling π', depend on π'. In FIG. 2, statements S 5 and S 6 are in projection π B , and statements S 1 , S 2 and S 3 are in π A . Statement S 6 uses variable V 4 defined by statement S 5 which depends on statements S 1 , S 2 and S 3 . Since S 6 depends on S 5 and S 5 depends on statements in π A , then π B depends on π A .
A projection π that depends on a sibling π' cannot commit until π commits. In FIG. 2 projection π B cannot commit until projection π A , is ready to commit. The delaying of commit will maintain the correctness of executions in the face of failures.
Projections act independently on ADS's. A projection acts on a single ADS reading data items into variables, using variables to perform computations and to define variables and data items. If no interaction with sibling projections occur the projection can commit. If a projection uses a sibling's variables, it depends on the sibling projection. Dependent projections must wait for siblings to commit to do likewise. A projection that depends on no siblings need not delay. In FIG. 2, projection π A can commit when ready since it does not depend on π B or any other sibling. Projection π B must delay commit until π A commits, since π B depends on π A . Correct and consistent execution results if projections of a transaction coordinate in this fashion.
Projections from distinct transactions cannot use variables defined within other transactions. For correct and consistent execution, projections from distinct transactions must be committed serializably with each other on individual atomic data sets.
A projection π A (i) from a transaction T i and a projection π A (j) from another transaction T j that act on the same ADS A must execute such that, the effects of the concurrently executing projections on the database either precede or follow each other. In the above example, projection π A (i) of T i either precedes execution of projection π A (j) of T j or π A (i) follows the execution of projection π A (j). The correct execution of conflicting projections is determined by formation of projection schedules for each atomic data set and checking if the schedules are serializable.
Conventional two-phase locking breaks execution into two phases, lock acquisition and lock release. In the first phase, the growing phase, transactions acquire locks on database items as needed. Once a transaction completes execution, it enters the second phase, the shrinking phase, when transactions release locks. A transaction that has released its locks cannot acquire more locks.
Locks are requested from the lock manager. If locks are not already held on an item or requested locks are compatible with those held, locks are granted. If the lock manager cannot grant a request, the requesting transaction is placed in a wait state. Upon releasing a lock, waiting transactions are unblocked.
In two-phase locking, deadlocks can occur and must be detected or avoided. The locking protocol disclosed herein detects deadlocks. When a transaction initially accesses an ADS, a node in the transaction waits-for graph is created. The waits-for graph is periodically tested for cycles. If deadlock is detected, a victim is chosen and aborted.
In the early commit locking protocol, sets of locks can be released during different stages of a transaction's execution. A transaction acquires a lock on a data item before that transaction's first access to the data item and releases the lock when access to an ADS is complete. Locks cannot be acquired or reacquired on an ADS by a transaction that has released locks on the ADS.
Primitives such as lock request and lock release are the same as in conventional locking approaches. The difference is in the duration of lock holding and lock acquisition being performed separately for each ADS. A projection π A requests locks from ADS A for reads and writes to a data item in A. Conflicts on locks cause waiting as in conventional system, though the duration of the wait may be shorter since waits are on ADSs instead of large monolithic databases.
Another difference from conventional systems occurs when deadlock is detected. Failed transactions are not totally aborted, only projections conflicting with the deadlocked transaction's projections on the same ADS are aborted. In discussing this protocol, let T be a transaction identifier, x be a data item. As used hereinafter, subterminate represents a subcommit or subabort operation. Transaction T operates by requesting locks on data items using read data item x, r(x), or write data item x, w(x), operations. On the last access to an ADS A, a transaction releases locks using a subterminate command, subcommit, sc A , or subabort, sa A . The example in FIG. 3, performs access to three atomic data sets ADS A, ADS B, and ADS C using parallel executions. Data item x is in ADS A, data item y is in ADS B, and data item z is in ADS C. The execution of these three projections can be performed nonserializably with other transactions' projections on the same ADSs. Given that π 1 represents all accesses to ADS A from transaction T, π 2 accesses to ADS B, and π 3 accesses to ADS C. π 1 , π 2 and π 3 can be executed concurrently if no depends-on relationships exist between the projections.
Referring now to FIG. 4, there is shown a flow chart for the command execution process of the early commit locking protocol. Locks are managed for each atomic data set separately. If no locks are held on any of the atomic data sets then all three accesses can be handled concurrently. If locks are held on one of the atomic data sets requested then only that projection is delayed, not the entire transaction. In the above example projection π 1 acting on ADS A can perform its access and commit even if projection π 2 acting on ADS B and projection π 3 acting oil ADS C are forced to wait until locks on data items in ADS B and ADS C are released. This allows other transactions to access AD', A before transaction T commits, increasing concurrency.
The lock manager receives lock requests from transactions. If the request does not conflict with held locks, the request can be granted. If a lock cannot be granted, the requester's projection is blocked and an edge is added to the waits-for graph. The waits-for graph is checked for cycles. If cycles are found, the requester's transaction is selected as a victim, restarted, releasing held data items for other projections' use.
For example, in FIG. 5, if two transactions T 1 and T 2 execute on the same ADSs, a deadlock between transactions T 1 and T 2 exists in a conventional database, while no deadlock exists in the disclosed early commit locking protocol. In this example, a lock by a projection is represented as π X (Y) where X is the ADS being locked and Y is the transaction locking the projection. In the example, A and B are distinct ADSs with variable a being in ADS A and b being in ADS B. In step one of this example, execution of the w(a, v a ) statement in T 1 causes the system to create a node π A (1) in the waits-for graph representing the lock acquired on data item a in ADS A. Another node, π B (2), is created by the execution of the w(b, v b ) statement in T 2 . At step two, T 1 attempts to execute v b :=r(b) causing the lock manager to attempt to place a lock on data item b in ADS B. Because a lock is already held because of T 2 's statement in step one, the lock manager does not allow the lock. No cycles are detected so the system inserts a node π A (2) and an edge 1 in the waits-for graph and waits for the lock to be released before executing the statement. The T 2 statement, v a :=r(a), attempts to execute but is also delayed; however, the system detects cycling indicating a deadlock.
In the inventive protocol, deadlocks are resolved by merging waits-for graph nodes from the same transaction into a single node when there are depends-on relationships between sibling projections. In FIG. 5, π A (1) and π B (1) are merged into a single node because, as indicated by the cycling, π A (1) depends on π B (1). The merged graph is again examined for cycles. Since in this case there is an edge between new node π A ,B (1) and π B (2), and another single edge between π A (2) and merged node π A ,B (1), no cycles are found, and no further action is required. π B (2) commits allowing projection π B (1) to acquire needed data items and to commit. Once the combined projections commit waiting projection π A (2) can acquire needed data items and also commit.
If, in addition to the data use dependencies between sibling projections of transaction T 1 , there is a depends-on relationship between sibling projections of transaction T 2 then the system merges projection π A (2) and projection π B (2) into a single node. The reduced waits-for graph is reexamined for cycles. If cycles continue to exist, a projection must be aborted. The system call be optimized to abort the projection which is farthest from commit, the projection which is least critical, or the projection which has spent the least time in processing. After commit of the conflicting projection, the aborted projection can be restarted.
The mechanisms to construct an early commit locking protocol are the same as in conventional locking systems. Accesses are controlled by lock and unlock operations. The difference is in how lock tables are used and controlled. Locks are maintained as a set of lock tables with each ADS having a single table representing the locks held on the ADS's data items.
All requests for locks and unlocks are sent to the appropriate ADS lock table. Entries in the lock table are examined on all lock requests to compute if the request can be satisfied. If a request can be satisfied, requested locks are set and the requested operation is performed. The table for each ADS is maintained in its master pointer block in the ADS index, as an extra field in the index entries. To maintain the correct status of locks, the new master index must possess the same settings for locks on commit. This is accomplished by making the copying of lock settings part of the commit process. Until all locks have been set in the committing projections copy index, the master is maintained as the prime index. When the committing projections copy index is ready, the master pointer is updated to point to the new master, the committing projection copy index.
The early commit locking protocol of this invention differs from conventional protocols in fundamental ways. The database is composed of a collection of atomic data sets instead of a single monolithic database. Each ADS maintains consistency in isolation from other ADSs. Transaction operations are partitioned over ADSs. Each transaction's collection of operations on an ADS constitutes a projection of these operations over the ADS. Projections from distinct transactions operate on individual ADS serializably. Locking is handled on a projection basis using a waits-for graph to detect and recover from transaction errors.
The advantages of the present invention over the prior art are that the early commit locking protocol allows multiple transactions to be executed concurrently using the same atomic data set. Transaction errors are avoided by merging projections before the projections are aborted. A projection is aborted only if merging and rescheduling cannot resolve the error.
Obviously many modifications and variations of the present invention may become apparent in light of the above teachings. In light of the above, it is therefore understood that within the scope of the appended claims, the invention may be practiced otherwise than as specifically described.
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A computer database method wherein the data is organized into atomic data ts and transactions are separated into projections which operate on only one atomic data set. Multiple transactions can thereby access the same atomic data set using a locking protocol wherein locks are held by each projection. On access to a data item, the system detects existing locks. If locks are not found, the system locks the data and performs the access. When existing locks are found the system delays execution of the command and determines if a deadlock is present. To recover from a deadlock, related projections are merged together and reexecuted. The system merges related projections from other transactions and reexecutes if the deadlock continues. When the deadlock continues after execution of the above steps, a victim projection is chosen and aborted. The victim projection is restarted after commit of the conflicting projection.
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FIELD OF THE INVENTION
[0001] This invention relates to transportable farm implements. Although the title designates the preferred embodiment of a disc harrow, the apparatus is suitable for suspending any number of work tools from the structure, such as sprayers, fertilizers, planters, tillers, etc. The apparatus is convertible from a working mode, in which wings are spread to a maximum width to permit farm operations to cover a wide swath with each pass, and a transport mode, in which the wings are folded into a compact width and height such that is can legally be transported on roads and highways without special permits, escorts, lighting, or hours of transporting.
BACKGROUND OF THE INVENTION
[0002] The prior art contains numerous patents for farm implements that are convertible between a transport mode and a use mode. Thus, U.S. Pat. No. 5,715,893 discloses a towable farm implement having wings that are lifted on a turntable and rotated 90 degrees, so that the wings that extend laterally in the use mode are lifted and rotated to fore and aft positions extending from the turntable. FIG. 9 of that patent shows a long tongue member 24 for hitching to a tractor to tow the implement from a storage location to a use location. Such an apparatus could not be transported on a highway from a manufacturing site to a customer without special permits, escorts and hours of transportation. There is a need for a farm implement that can be shipped from manufacturer to farmer by common carrier on highways without the need for escorts, special permits, flashing lights or restricted hours of transport.
[0003] U.S. Pat. No. 4,159,038 discloses an earthworking implement having foldable wings to allow movement of “implements that are over ten meters or more wide from one field to another” (column 1, lines 15-16). Road-legal limits vary from jurisdiction to jurisdiction, but commonly a load cannot be more than eight feet wide nor more that fourteen feet above the road, much less than the dimensions of the load in this patent. Similarly U.S. Pat. No. 3,692,121 shows liftable wings that can be raised to a position over the main frame, but the main frame is not road-legal, so the apparatus cannot be transported over the highway from the manufacturer to the user without special permits. Both of these prior art patents use fluid cylinders of long thrust to lift the wings (82 in the '038 patent and 42 in '121).
[0004] Likewise, U.S. Pat. No. 4,479,554 has a main frame that is not road-legal, so lifting the wings cannot make it road-legal. Moreover, a piston cylinder 110 has a long thrust in this patent. There is a need for a road-legal apparatus that can be folded compactly by means of a short thrust cylinder.
SUMMARY OF THE INVENTION
[0005] The present invention provides a road-legal farm implement that can be expanded to work a wide swath by activating a fluid pressure cylinder powered by the hydraulic system of the towing vehicle as is common in the art. A bridge above the main frame holds a fluid cylinder that pushes lifting arms to raise wings to a location above the main frame within a road-legal envelope. The basic frame is approximately eight feet in width with dependent work implements. The wings, when lowered to the work position, extend approximately eight feet each, one laterally extending forward of the main frame and the other extending laterally rearward from the main frame. Two sets of wings may be added to a tandem harrow on the main frame. Each wing is raised by a single small hydraulic cylinder with a stroke as short as eight inches and a bore of approximately three inches. When in the transport position, wheels located in width slightly less than the road-legal width provide maximum stability while being transported. All wings are folded above the wheels so that no part of the wings or other elements of the apparatus extends beyond the plane formed vertically from the outer edges of the wheels.
BRIEF DESCRIPTION OF THE DRAWINGS
[0006] [0006]FIG. 1 is an isometric view of the main frame that supports the apparatus.
[0007] [0007]FIG. 2 is a front elevation view of the front wing assembly and main gang in the work position.
[0008] [0008]FIG. 3 is an isometric view of the bridge assembly.
[0009] [0009]FIG. 4 is a front elevation view of the front wing assembly and main gang in the transport position.
[0010] [0010]FIG. 5 is an isometric view of the hitch assembly.
[0011] [0011]FIG. 6 is an elevation view of an alternate hold-down assembly.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0012] [0012]FIG. 1 illustrates the main frame 11 that rides on a sufficient number of wheels with pneumatic tires to support the weight of the apparatus. I have found that four 15″×18″ wheels 12 , 13 , 14 and 16 , mounted on axle 17 transversely to the main frame 11 are sufficient to support the weight of the apparatus in the transport mode. 9.5L tires are suitable. Axle 17 rides on axle blocks, one of which is shown at 18 in FIG. 1. Wheels 12 , 13 , 14 and 16 are rotatable from a tilling position in which the work implements engage the soil (the “up” position) and a transport position in which the wheels engage the surface being traversed (the “down” position). As shown in FIG. 1, axle block 18 carries blocks 19 which support rod 20 . Welded plates 15 engage rod 20 to permit rotation of rod 20 between the up position and the down position. Each wheel 12 , 13 , 14 and 16 rotates about an axle 17 , which is carried on plate 15 attached to rod 20 , which rotates in the series of blocks 19 , to place wheels and implements in the desired transport or work position.
[0013] Frame 11 consists of two main parallel rails 21 and 22 inboard of the outer wheels 12 and 16 as the primary load bearing elements running longitudinally front to rear. At the front ends of rails 21 and 22 are hangers 26 and 27 from which a conventional hitch (not shown) depends for towing by a tractor or other towing vehicle. Outboard of the rails 21 and 22 are stabilizers 23 and 24 . Stabilizer 23 carries axle block 18 and encloses wheel 12 to provide maximum stability in the transport mode. Stabilizer 23 also supports the wing assemblies presently to be described in a manner to minimize roll in the transport mode. Stabilizer 24 operates in the same way as stabilizer 23 , but on the right side.
[0014] Rails 21 and 22 are separated by forward cross member 28 and rear cross member 29 . Forward cross member 28 supports a center mount 31 for the hitch (not shown). Rail 21 supports gang attachment 32 for the forward gang of discs or other farm implements supported by the main frame. Multiple holes in gang attachment 32 allow for adjustable angles for the main gang relative to the direction of towing in the work position. A pin (not shown) permits the user to select the desired hole for the angle needed for the work task, as is conventional. Gang attachment 33 is mounted on the rear of rail 21 to accommodate the rear gang of work implements attached to the main frame. Following discs on tandem harrows typically require less adjustment, so rear gang attachment 33 has fewer holes.
[0015] Between main rails 21 and 22 are inboard rails 36 and 37 that support a conventional wheel raising apparatus to lift the wheels from the lower transport position to the raised work position in which the discs or other farm implements can engage the soil. Wheel 13 rides between rail 21 and rail 36 , and wheel 14 rides between rail 37 and rail 22 . A conventional hydraulic wheel raising attachment (not shown) is mounted on rails 36 and 37 at rear mount 38 and forward mount 39 . Because the load in raising the wheels is primarily borne on the front mount 39 , there are additional wheel-raising cross members 41 and 42 to carry the load to the main rails 21 and 22 .
[0016] [0016]FIG. 2 illustrates the front wing assembly 46 in the work position with wings 47 and 48 extended from main gang 49 in a continuous array of work implements. Each of wings 47 and 48 and main gang 49 has a desired number of discs or work implements dependent therefrom. FIG. 2 only shows two discs rotatable in blocks 51 and 52 , but it will be understood that any number of implements and blocks may be attached to gangs 47 , 48 and 49 . As is conventional in tandem disc harrows, the forward discs turn soil over in one direction and rear discs turn the soil in the opposite direction. Accordingly, the rear wing assembly (not shown) is identical to the front wing assembly in FIG. 2 except that the discs are in the opposite direction.
[0017] Wings 47 and 48 each have brackets 53 and 54 , respectively, welded to the beam to provide pivot pins 56 and 57 , respectively, for raising the wings 47 and 48 . Brackets 53 and 54 allow the main frame 11 (FIG. 1) to extend between brackets 53 and 54 above main gang 49 , which is releasably attached to the main frame (not shown in FIG. 2). Each of brackets 53 and 54 is attached by one or more bolts 58 and 59 to bridge assembly 61 spanning the space above main frame 11 and anchoring pivot pins 62 and 63 about which upper arms 64 and 66 pivot.
[0018] Upper arms 64 and 66 are connected, through elbows 67 and 68 , respectively, to lower arms 69 and 71 , which are, in turn, attached to braces 72 and 73 , respectively, welded to wings 47 and 48 . Braces 72 and 73 have holes into which pins 74 and 76 are inserted to provide pivot points for lower arms 69 and 71 , respectively.
[0019] Lifting of wings 47 and 48 is accomplished by hydraulic cylinders 77 and 78 for each wing connected to the hydraulic system of the towing vehicle. Cylinders 77 and 78 are relatively small, given the weight of the apparatus, and achieve the lifting task by pushing upper arms 64 and 66 upwardly about pivot points 62 and 63 . I prefer a hydraulic cylinder with a stroke of less than 12 inches, with an 8 inch stroke and 3 inch bore being optimum. The cylinders 77 and 78 are shown in FIG. 2 in a closed position, with the rod of cylinder 77 attached to pin 79 through a projection in upper arm 64 . Likewise, Cylinder 78 is attached to pin 81 in a projection of upper arm 66 . Cylinder 77 , at its lower end, is attached to pin 82 in bracket 53 . Cylinder 78 has a corresponding pin 83 in bracket 54 .
[0020] When cylinders 77 and 78 are activated, they push upper arms 64 and 66 upwardly through pins 79 and 81 , respectively to cause arms 64 and 66 to rotate about pins 62 and 63 . Lower arms 69 and 71 also raise, pivoting about elbows 67 and 68 , at the upper end, and pins 74 and 76 at the lower end. The movement of only eight inches of the piston rods in cylinders 77 and 78 is sufficient to raise wings 47 and 48 to a position for transport inside the vertical plane defined by the outer limits of stabilizers 23 and 24 (FIG. 1).
[0021] [0021]FIG. 3 is a detail of the bridge assembly 61 shown in FIG. 2. Bridge 61 has two parallel plates 85 and 86 of identical configuration. One or more holes 58 and 59 are formed in the outward ends of the plates 85 and 86 to adjustably attach to corresponding holes 58 and 59 in brackets 53 and 54 (FIG. 2). Plates 85 and 86 are connected by welded plates 87 , 88 and 89 to keep them rigidly parallel. The pivot pins 62 and 63 of FIG. 2 are accommodated by tubes 91 , 92 , 93 and 94 aligned with holes 96 and 97 in plate 85 . Corresponding holes (not shown) are in plate 86 . This reinforcement serves to enhance the main load-bearing pivot pins 62 and 63 .
[0022] [0022]FIG. 4 shows the assembly of FIG. 2 in a folded position for transport. Cylinders 77 and 78 have their rods 101 and 102 extended less than twelve inches. This raises upper arms 64 and 66 by pushing on pins 79 and 81 attached to projections on arms 64 and 66 . Lower arms 69 and 71 extend between elbows 67 and 68 and pins 74 and 76 in braces 72 and 73 , respectively. In the folded position, locking pins 103 and 104 pass through each of lower arms 69 and 71 and braces 72 and 73 to prevent wings 47 and 48 from accidentally jarring loose from the folded position.
[0023] [0023]FIG. 5 illustrates the hitch assembly 105 for towing the apparatus in either the work position or the folded transport position. Parallel plates 106 and 107 are welded to cross member 108 forward of main frame 11 (FIG. 1). In FIG. 1, the left side is the forward end of the frame and the right side is the aft end of frame 11 . In FIG. 5, however, the left side is the aft end of the hitch assembly 105 and the right side is the front end, the opposite of FIG. 1. Thus, forward facing U-shaped brace 110 has holes 111 and 112 that permit a pin (not shown) to extend through each hole and tube 113 at the front end of hanger 26 (FIG. 1) to secure the left side of the hitch to the left side of the main frame 11 . Similarly, U-shaped brace 116 on hitch assembly 105 extends rearwardly to embrace hanger 27 and tube 114 (FIG. 1) to permit a pin (not shown) to extend between holes 117 and 118 through tube 114 , whereby the right side of hitch assembly is attached to hanger 27 of frame 11 . A plurality of holes 121 permit the hitch assembly 105 to be adjustably secured to the towing vehicle for the desired pitch of the working implements in relation to the ground. Hole 122 allows a pin to attach a tongue (not shown) connecting the hitch to the towing vehicle.
[0024] [0024]FIG. 6 shows an alternate hold-down assembly to hold down wings in the work position, while permitting them to flex when being raised or lowered. As illustrated in FIG. 2, lower arm 71 is secured to brace 73 by means of pin 76 . While this configuration is suitable for work applications, it does not permit the wing 48 to flex as it is being folded up or down. In a preferred embodiment, I use an additional hold-down assembly 126 outboard of the brace 73 . Assembly 126 consists of an arm 127 extending between a riser 128 secured to wing 48 , as by welding. Arm 127 pivots on pin 129 extending through riser 128 . Arm 127 is in two parts separated by turnbuckle 131 , allowing the two parts to be adjusted in length. Arm 127 extends through box 132 , consisting of two parallel welded plates, only one of which is shown at 133 , secured to wing 48 , as by welding. Arm 127 slidably passes through the box 132 as the wing 48 flexes during raising and lowering. Box 132 is formed by the two plates 133 , upper pin 134 and lower pin 136 separating the plates 133 . Given the length of wing 48 and the flexibility of steel, arm 127 can be adjusted by turnbuckle 131 to allow arm 127 to pass through box 132 to the extent necessary. When the wing 48 is lowered to the work position, it may be held down solid and immovable by placing a pin (not shown) in hole 137 . The pin engages box 132 to prevent arm 127 from sliding through between plates 133 , making it immovable, barring the flexing of wing 48 in the work position.
[0025] The road-legal requirements for transporting on roads and highways vary by jurisdiction. It is the intent of this invention to comply with the legal requirements of all jurisdictions. As an example, many jurisdictions will permit loads on roads without escorts, wide load signs, or special permits if they do not exceed eight feet in width nor fourteen feet in height. However, because these limitations may change over time, I do not want to be limited to this particular example.
[0026] The embodiments described above have been described with particularity to enable one skilled in the art to make and use them. Modifications and changes from these embodiments may be made by one having ordinary skill in the art without departing from the inventive concepts defined in the claims.
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A farm implement convertible between a work position and a transport position is disclosed. In the transport position, a compact package is formed less than eight feet in width and less than 14 feet in height. Right and left wings connected to the main frame may be raised by pushing articulated arms a short distance to fold the wings above the main frame.
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BACKGROUND OF THE INVENTION
This invention relates to novel intravenous solutions for influencing renal function and for follow-up maintenance therapy. An intravenous solution of the invention is more particularly for treating altered renal function or for prophylactically conditioning the kidney to resist that the kidney enters a condition of altered renal function. The term altered renal function as employed herein means a qualitatively and quantitatively depleted or insufficient production of urine, insufficient clearance of metabolic and toxic substances normally cleared by the kidney such as electrolytes, urea, creatinine, phosphates, endogenous and exogenous toxins, pharmaceuticals and their metabolites, a depleted or insufficient ability of the kidney to acidify the urine by excretion of non-volatile or strong acids, or a depleted or insufficient capability of the kidney to produce bicarbonate and thus inability of the kidney to maintain a metabolic acid-base balance within acceptable limits. In such conditions, the therapy normally involves administration of diuretics, preferably loop diuretics, to encourage diuresis.
The intravenous solution of the invention in general finds application in treating patients preliminary to, during and after surgical intervention or any other condition or treatment which may lead to altered renal function. Examples of treatment with potentially nephrotoxic substances include contrast media, antibiotics, cytostatics, cytotoxic drugs, and immuno suppressive drugs. A wide variety of solutions, some being described as substitution fluids are employed for intravenous administration. Commonly used solutions and their compositions are shown in the following Table I:
TABLE I__________________________________________________________________________ Concentrations Ionic concentration mval/literSolution Solute g/100 ml (Na.sup.+) (K.sup.+) (Ca.sup.2+) (Cl.sup.-) (HCO.sub.3.sup.-)__________________________________________________________________________Dextrose in water 5.00% Glucose 5.00 -- -- -- -- --10.00% Glucose 10.00 -- -- -- -- --SalineHypotonoc (0.45%, NaCl 0.45 77 -- -- 77 --half normal)Isotonic (0.9%, NaCl 0.90 154 -- -- 154 --normal)Hypertonic NaCl 3.00 513 -- -- 513 -- 5.00 855 -- -- 855 --Dextrose in saline5% in 0.22% Glucose 5.00 -- -- -- -- -- NaCl 0.22 38.5 -- -- 38.5 --5% in 0.45% Glucose 5.00 -- -- -- -- -- NaCl 0.45 77 -- -- 77 --5% in 0.9% Glucose 5.00 -- -- -- -- -- NaCl 0.90 154 -- -- 154 --Ringer's NaCl 0.86 KCl 0.03 147 4 5 156 -- CaCl.sub.2 0.03Lactated Ringer's NaCl 0.60 KCl 0.03 CaCl.sub.2 0.02 130 4 3 109 28 Na lactate 0.31 0.31Hypertonic sodium NaHCO.sub.3 5.00 595 -- -- -- 595bicarbonate (0.6 M)Hypertonic sodium NaHCO.sub.3 7.50 893 -- -- -- 893bicarbonate (0.6 M)Potassium chloride KCl 14.85 -- 211 -- 2__________________________________________________________________________
Administration of the Dextrose solutions is physiologically equivalent to the administration of distilled water since glucose is rapidly metabolized to CO 2 and H 2 O. The Dextrose is however essential to render the solution isotonic and thus avoid hemolysis. The Saline solutions are most commonly administered since most patients in need of treatment are not only water-depleted but also Na + depleted, i.e. salt-depleted.
The plasma Na + concentration can be employed to assist in determining which of the above Dextrose, Saline or Dextrose in Saline solutions is most appropriate. The Dextrose solutions provide a small amount of calories, for example the 5% Dextrose or 5% Dextrose in 0,22% saline is equivalent to 200 kcal per liter of solution.
The Ringer's solutions comprised in the above Table include physiologic amounts of K + and Ca ++ in addition to NaCl. The lactated Ringer's solution comprising 28 mEq of lactate per liter (which metabolizes to HCO 3 - ) has a composition close to that of extracellular fluid.
The hypertonic Sodium bicarbonate solutions are primarily employed in the treatment of metabolic acidosis for example by administration of a 7.5% or higher solution comprised in 50 ml ampuls, but can be added to other intravenous solutions, however not including the Ringer's solutions since precipitation of the HCO 3 - with the Ca ++ would take place. Similarly, the Potassium Chloride solution can be added to other intravenous solutions, but care needs to be taken not to intravenously administer any concentrated solution of K + since this can produce an excessive or too rapid increase in plasma concentration of K + , which can be fatal.
Other than the above-mentioned hypertonic Sodium bicarbonate solutions, none of the above solutions are known to have any specific influence on kidney function. The hypertonic Sodium bicarbonate solutions on the other hand are normally administered only in limited quantities, at most in quantities sufficient to temporarily correct, normally only in part, a condition of metabolic acidosis. Suggestions to intravenously administer higher quantities of the available Sodium bicarbonate solutions has met with understandable resistance in view particularly of the fact that such solutions are strongly hypertonic and all comprise very much more than or less than physiological amounts of cation solute. Thus, for example the above-mentioned higher concentration 7.5% Sodium bicarbonate solution available in 50 ml ampuls comprises about 900 mval of Na + , and 900 mval of HCO 3 - per liter of solution which is neither physiological for Na + nor for HCO 3 - . In contrast, the normal value for Na + in the blood is from 135 to 146 mval/liter and the normal value for HCO 3 - is 22 to 26 mval/liter.
SUMMARY OF THE INVENTION
In accordance with the invention, it has been found that relatively large quantities of a solution comprising higher than physiological concentrations of HCO 3 - can be intravenously administered provided that the Sodium content of the solution is not significantly different from physiological levels, i.e. not significantly different from about 135 to about 146 mval/liter. Sodium is the most important electrolyte cation and any significant deviation from physiological concentrations as could arise from i.v. administration of any larger quantity of intravenous solution containing more or less than physiological levels of Na + may create undesirable and dangerous side effects. Thus, if for example any substantial quantity, say in excess of 200 ml, of the 7.5% (0.9M) i.v. sodium bicarbonate solution discussed above were administered to a patient, the patient would tend towards a condition of hypersodemia which has toxic consequences. A condition of hyposodemia similarly can have life endangering consequences so that in general and presuming that the sodium levels in the serum of the patient are within physiological limits, the intravenous solution of the invention comprises a sodium concentration which substantially matches physiological concentrations. On the other hand, as already indicated, the bicarbonate anion concentration in the solution can be very substantially higher than physiological concentrations. However, concentrations of bicarbonate as high as those comprised in known sodium bicarbonate intravenous solutions are not contemplated. The reason is that an excessive or too rapid an increase of bicarbonate in plasma can be fatal as a consequence of systemic alkalosis or hypercapnea (excessive CO 2 concentration arising from decomposition of HCO 3 - into CO 2 and H 2 O). Other anions and cations comprised in the intravenous solution of the invention would in general be within or close to physiological levels. Thus, potassium cation would normally be present in the solution at physiological concentrations but could be left away especially if the patient is inclined to hyperkalemia as is sometimes the case. Similarly, chloride anion would be present at physiological levels but can be lower, which latter solution can find use for a patient which is in a condition of hyperchloremic acidosis, as is also sometimes the case.
In the major proportion of cases in which intravenous infusion of fluids is required, the functioning of the kidney of the patient, even if the kidney was initially healthy, may have been or will be altered by a planned medical intervention. For example, renal dysfunction and failure can be a result of heavy injury or massive intervention. Also, however, many patients requiring infusion of fluids, are in any case already suffering from altered or impaired renal function, e.g. because of age or pre-existing disease. Kidney functions are inadequate in a large majority of cases and it is an object of the present invention to provide a novel intravenous solution which is able in particular to acidify the urine, i.e. to increase the capacity of the kidney to excrete hydrogen ions and metabolic acids in the urine, and to increase the volume of urine i.e. the excretion of excess water, (along with increased clearance of substances normally entrained in the urine). Furthermore, in general, the novel solutions of the present invention can serve to correct any systemic acid-base or electrolyte disorders which may be associated with a condition of acute or chronic renal failure or prevention thereof requiring treatment by intravenous infusion of fluids.
The intravenous solutions of the invention essentially act on the whole length of the renal nephron-segments, i.e. the renal tubulae, in particular on the proximal tubulae, whereas loop diuretics essentially act on the distal tubulae. A combination of the two effects enables the action of the loop diuretic to be potentiated which can offer means for reducing the dose required, and diuresis to be increased. The supply of bicarbonate contained in the solutions of the invention provide an essential substrate for beneficial conditioning renal function.
DETAILED DESCRIPTION OF THE INVENTION
An intravenous solution in accordance with the invention comprises at least the following anions and cations, in amounts, i.e. concentrations, within the ranges indicated in the following Table II:
______________________________________ mval/liter (preferably)______________________________________Na.sup.+ 130 to 150 135 to 146K.sup.+ 0 to 6 2 to 5Cl.sup.- 80 to 125 90 to 110HCO.sub.3.sup.- 25 to 30 to 70 40 to 60______________________________________
A typical solution useful for treating altered renal function comprises the following amounts and concentrations of electrolytes:
______________________________________ mval/liter______________________________________Sodium Chloride 5.026 g Na.sup.+ 146Potassium Chloride 0.298 g K.sup.+ 4Sodium Bicarbonate 5.040 g Cl.sup.- 90Water for infusion solution to 1000.0 ml HCO.sub.3.sup.- 60______________________________________
Once treatment with a solution such as above has achieved the desired results for a reasonable period, i.e. increased urine volume and stabilized acid-base balance for 24 hours or more, a solution comprising less bicarbonate ions, i.e. less than 40 mval/liter but not lower than physiological levels, i.e. 25 mval/liter may be employed for maintenance therapy. However, since it is important that sodium levels not depart significantly from physiological levels, lowering of the bicarbonate content requires an increase in Sodium Chloride content which in turn leads to an increase in Chloride content. Hyperchloremia is often attendant to altered renal function so that increased chloride above physiological levels would in general be avoided.
The dose of intravenous solution administered will of course depend on the weight of the patient, the condition of the patient, specifically the fluid balance, and the effect desired. However, in general, satisfactory results for treating altered renal function and achievement of increased urine volume and associated desired results such as increased clearance of metabolites and toxins, fixed or strong acids, phosphates and the like are obtained when a solution comprising more than about 40 mval/liter of bicarbonate anion is administered at a rate of from 50 to 500 ml of solution/hour (about 15 to 180 drops/min). The total dose required for an adult in twenty-four hours can be as much as 12 liters (=500 ml/hour). An indication of whether or not the dose is adequate can be obtained by blood gas analysis and by measuring fresh urine pH value. If the urine pH value tends towards or is slightly greater than 7.0, adequate dosage has been achieved. Exemplary clinical trials performed with a bicarbonate-electrolyte solution of the invention are summarized below. The six patients were all urological post-operative patients suffering from prostate or kidney carcinoma.
Diagnosis: Prostate-Carcinoma
Operation: Radical Lymphadenectomy
Progression: Diuresis:
1st day: 1085 ml
2nd day: 4130 ml
3rd day: 5270 ml
4th day: 4600 ml
5th day: 1550 ml up to 6 p.m.
(otherwise from 6 a.m. to 6 a.m.)
Infusion program:
1st day:
3000 ml Bicarbonate-electrolyte solution
1000 ml Glucose 5%
2nd day:
2000 ml Combiplasmal
2000 ml Bicarbonate-electrolyte solution +20 mg Lasix +40 mval KCl
1000 ml Ringer
3rd day:
2000 ml Bicarbonate-electrolyte solution +20 mg Lasix +40 mval KCl
2000 ml Combiplasmal
500 ml Glucose 5%
1000 ml Ringer
4th day:
2000 ml Bicarbonate-electrolyte solution +20 mg Lasix +40 mval KCl
1000 ml Glucose 5%
160 ml Combiplasmal
1000 ml Aminosteril 10%
2000 ml Ringer
5th day:
500 ml Aminosteril 10%
500 ml Glucose 5%
1000 ml Ringer
1000 ml Bicarbonate-electrolyte solution +20 mg Lasix +20 mval KCl infused up to 6 p.m.
Balance:
1st day: 2715 ml
2nd day: 870 ml
3rd day: 680 ml
4th day: 1310 ml
5th day: no balance established
Serum values:
1st day:
pH 7,37, PCO 2 39 mmHg, HCO 3 - 23 mmol/l, BA -1.6.
2nd day:
pH 7,42, PCO 2 42 mmHg, HCO 3 - 28 mmol/l, BA +3.6.
Urea-N. 27 mg/dl (7-18), Creatinine 2,3 mg/dl, Ca 8,4 mg/dl.
Phosphorous (inorg) 5,5 mg/dl, Protein 5,2 g/dl (other values normal).
3rd day:
all values normal except Urea-N. 26 mg/dl, Creatinine 2,0 mg/dl.
Uric acid 8,3 mg/dl, K + 3,2 mmol/l.
4th day:
all values normal except Urea-N. 25 mg/dl, Creatinine 1,6 mg/dl.
K + 3,3 mmol/l, Protein 5,6 g/dl.
5th day:
pH 7,41, PCO 2 46 mmHg, HCO 3 - 29 mmol/l, BA +4,2.
Urea-N. 33 mg/dl, Creatinine 1,5 mg/dl, K + 3,4 mmol/l, Ca 8,5 mg/dl, Protein 5,9 g/dl.
Normal range of Serum values:
Blood gas analysis, venous blood:
pH: 7,32-7,38
PCO 2 : 42-50 mmHg
HCO 3 - : 23-27 mmol/l
BA: 0±2,3 mmol/l (BA=base excess/or deficit value)
Serum values:
Urea-N: 7-18 mg/dl
Creatinine: 0,5-1,3 mg/dl
Uric acid: 3-7 mg/dl
Phosphorous (inorg): 2,5-4,5 mg/dl
Protein: 6,0-8,0 g/dl
Na + : 135-146 mmol/l
K + : 3,5-5,0 mmol/l
Cl - : 97-108 mmol/l
Calcium (total): 8,7-10,5 mg/dl
Summary
High daily urine volumes, uncomplicated progression. Transferred to General clinic on 5th postoperative day. Adequate control of serum metabolites concentration. Electrolyte and acid-basis-balance essentially normal, mild potassium- and Protein-deficit. Observation period 5 days.
Diagnosis: Kidney-Carcinoma
Operation: Nephrectomy
Progression: Diuresis:
1st day: 2280 ml
2nd day: 2020 ml
3rd day: 1700 ml (intensive transpiration)
4th day: 2640 ml
Infusion program:
1st day:
2000 ml Bicarbonate-electrolyte solution +20 mg Lasix +40 mval KCl
1000 ml Glucose 5%
2nd day:
1000 ml Glucose 5%
2000 ml Bicarbonate-electrolyte solution +40 mval KCl +20 mg Lasix
3rd day:
2000 ml Bicarbonate-electrolyte solution +40 mval KCl +20 mg Lasix
1000 ml Glucose 5%
500 ml Ringer
4th day:
2000 ml Bicarbonate-electrolyte solution +20 mg Lasix +40 mval KCl
1000 ml Glucose 5%
5th day:
2000 ml Bicarbonate-electrolyte solution +20 mg Lasix +40 mval KCl
1000 ml Glucose 5%
6th day:
1000 ml Bicarbonate-electrolyte solution
500 ml Glucose 5%
Balance:
1st day: +570 ml
2nd day: +1530 ml
3rd day: +1600 ml
4th day: +1000 ml
5th day: +1300 ml
Serum values:
1st day:
not determinated.
2nd day:
Uriea-N 19 mg/dl, Creatinine 1,8 mg/dl, Ca 7,8 mg/dl, Protein 5,4 g/dl, (other values normal).
pH 7,45, PCO 2 45 mmHg, HCO 3 - 31 mmol/l, BA +7,1.
3rd day:
Urea-N 34 mg/dl, Creatinine 2,5 mg/dl, Uric-acid 7,6 mg/dl.
Ca 8,1 mg/dl, Protein 5,6 g/dl, (other values normal).
pH 7,49, PCO 2 40 mmHg, HCO 3 - 30 mmol/l, BA +7,1.
4th day:
Urea-N 49 mg/dl, Creatinine 2,4 mg/dl, Ca 7,4 mg/dl, Protein 5,2 g/dl, (other values normal).
5th day:
pH 7,46, PCO 2 33 mmHg, HCO 3 - 23 mmol/l, BA +1,1.
Urea-N 46 mg/dl, Creatinine 2,0 mg/dl, Protein 5,6 g/dl, Ca 8,0 mg/dl, (other values normal).
6 th day:
Urea-N 37 mg/dl, Creatinine 1,9 mg/dl, Ca 8,2 mg/dl.
Summary
High daily urine volumes. The observation period ended on the 6th day, when the patient was transferred to the General clinic. In general satisfactory progress. Essentially stabilized acid/base status, including serum concentration of metabolites, electrolytes, Na, K, Cl always at normal levels.
Diagnosis: Prostata-Carcinoma
Operation: Radical Prostatectomy, Pelvine Lymphadenectomy
Progression: Diuresis:
1st day: 1380 ml
2nd day: 4400 ml
3rd day: 4100 ml
4th day: 4250 ml
5th day: 4450 ml
6th day: 4100 ml
Infusion program:
1st day (after 3 p.m.):
1000 ml Bicarbonate-electrolyte solution
1000 ml Glucose 5%
1000 ml Ringer
2nd day:
2000 ml Combiplasmal
500 ml Lipofundin
500 ml Glucose 5%
2000 ml Bicarbonate-electrolyte solution +20 mg Lasix +40 mval KCl
500 ml Glucose 5%
3rd day:
2000 ml Bicarbonate-electrolyte solution
2000 ml Combiplasmal
1000 ml Glucose 5%
500 ml Lipofundin
4th day:
500 ml Lipofundin
2000 ml Combiplasmal +20 mval KCl
2000 ml Bicarbonate-electrolyte solution +20 mg Lasix +40 mval KCl
100 ml Humanalbumin
5th day:
500 ml Lipofundin
2000 ml Bicarbonate-electrolyte solution +20 mg Lasix +40 mval KCl
2000 ml Combiplasmal +20 mval KCl
500 ml Glucose 5%
1000 ml Ringer
6th day:
500 ml Lipofundin
1000 ml Combiplasmal
2000 ml Bicarbonate-electrolyte solution +20 mg Lasix +40 mval KCl
500 ml Glucose 5%
7th day:
500 ml Lipofundin
500 ml Glucose 5%
1000 ml Combiplasmal
1000 ml Bicarbonate-electrolyte solution +20 mg Lasix +20 mval KCl
all drugs until 12 a.m. then transferred
Balance:
1st day: +1670 ml
2nd day: +350 ml
3rd day: +1550 ml
4th day: +1120 ml
5th day: +2280 ml
6th day: +750 ml
Serum values:
1st day:
pH 7,36, PCO 2 48 mmHg, HCO 3 - 27 mmol/l, BA +1.5.
2nd day:
Protein 4,9 g/dl (6-8), Ca 7,6 mg/dl (8,7-10,5), other values normal.
pH 7,41, PCO 2 39 mmHg, HCO 3 - 25 mmol/l, BA +1,3.
3rd day:
Potassium 3,4 mmol/l, Protein 4,9 g/dl (6-8), pH 7,41, PCO 2 48 mmHg, HCO 3 - 31 mmol/l, BA +5,6.
4th day:
Potassium 3,3 mmol/l, Ca 7,8 mg/dl, Protein 4,7 g/dl, pH 7,43, PCO 2 39 mmHg, HCO 3 - 27 mmol/l, BA +3,1.
5th day:
Potassium 3,5 mmol/l, Ca 8,2 mg/dl, Protein 5,3 g/dl, pH 7,42, PCO 2 42 mmHg, HCO 3 - 27 mmol/l, BA +2,5.
6th day:
Ca 8,0 mg/dl (8,7-10,5), Protein 5,1 g/dl, pH 7,42, PCO 2 42 mmHg, HCO 3 - 27 mmol/l, BA +2,6.
7th day:
Ca 8,1 mg/dl, Protein 5,1 g/dl, pH 7,42, PCO 2 41 mmHg, HCO 3 - 27 mmol/l, BA +2,6.
Summary
Very high daily urine volumes. Uncomplicated progression, stabilized metabolites, electrolytes and acid-basis-balance, mild potassium-, calcium- and protein-deficit. Transferred to General clinic on 7th postoperative day.
Diagnosis: Kidney-Carcinoma
Operation: Nephrectomy
Progression: Diuresis:
1st day: 2760 ml
2nd day: 620 ml up to 10 a.m.
Infusion program:
1st day:
1000 ml Bicarbonate-electrolyte solution
2000 ml Bicarbonate-electrolyte solution +20 mg Lasix +40 mval KCl
500 ml Glucose 5%
500 ml Ringer
2nd day:
1000 ml Combiplasmal
1000 ml Bicarbonate-electrolyte solution +20 mval KCl +10 mg Lasix
250 ml Glucose 50%, up to 10 a.m.
Balance:
1st day: +1240 ml
2nd day: not evaluated
Serium values:
1st day:
normal.
2nd day:
Protein 4,9 g/dl, Creatinine mg/dl 1,4 mg/dl, Calcium 7,8 mg/dl, pH 7,44, PCO 2 45 mmHg, HCO 3 - 30 mmol/l, BA +6.
Summary
High daily urine volumes. Uncomplicated progression. Transferred to General clinic on 2nd postoperative day. Stabilized metabolites electrolytes and acid-basis balance. Mild protein- and Ca-deficit.
Diagnosis: Kidney-Carcinoma
Operation: Ventral Nephrectomy with Lymphadenectom
Progression: Diuresis:
1st day: 2800 ml
2nd day: 2700 ml
Infusion program:
1st day:
1000 ml Ringer (OP)
2000 ml Bicarbonate-electrolyte solution +20 mg Lasix +40 mval KCl
2nd day:
2000 ml Combiplasmal
2000 ml Bicarbonate-electrolyte solution +20 mg Lasix +40 mval KCl
500 ml Glucose 5%
Balance:
1st day: +200 ml
2nd day: +1700 ml
Serum values:
1st day:
not evaluated.
2nd day:
normal except Creatinine mg/dl 2,0 mg/dl.
pH 7,43, PCO 2 42 mmHg, HCO 3 - 28 mmol/l, BA +3,9.
Summary
High daily urine volumes. Progression without complications. Observation period 2 days. Metabolites concentration, electrolytes and blood gases essentially normal.
Diagnosis: Stenosis of Urethra, Prostata-Carcinoma, Diab. mellitus
Operation: Pelvine Lymphadenectomy
Progression: Diuresis:
1st day: 2880 ml
2nd day: 2200 ml
3rd day: 4030 ml
Infusion program:
1st day:
2000 ml Bicarbonate-electrolyte solution, +20 mg Lasix +40 mval KCl
1000 ml Glucose 5%
2nd day:
2000 ml Bicarbonate-electrolyte solution, 40 mval KCl, 20 mg Lasix
1000 ml Glucose 5%
3rd day:
2000 ml Bicarbonate-electrolyte solution, +40 mval KCl, 20 mg Lasix
4th day:
1000 ml Bicarbonate-electrolyte solution, +40 mval KCl, 20 mg Lasix
Balance:
1st day: -470 ml
2nd day: +1490 ml
3rd day: -530 ml
Serum values:
1st day:
Urea-N. 21 mg/dl (norm 7-18), Uric acid 8,9 mg/dl (-7).
other values normal.
2nd day:
mild higher value of Urea N. and Uric acid.
Protein 4,9 g/dl (6-8), Ca 7,8 mg/dl (8,7-10,5).
pH 7,41, PCO 2 49 mmHg, HCO 3 - 31 mmol/l, BA +5,4.
3rd day:
Chloride 96 mmol/l (97-108), Ca. 7,8 mg/dl, Protein 4,9 g/dl.
other values normal.
pH 7,49, PCO 2 48 mmHg, HCO 3 - 37, BA +12,5
4th day:
Uric acid. 8,9 mg/dl, Potassium 3,4 mmol/l, Ca 8 mg/dl.
Phosphor 2,3 mg/dl (2,5-4,5), Protein 4,9 g/dl.
other values normal
Summary
High daily urine volumes. Stabilized metabolites, electrolytes-values, Protein mildly lower. Transferred to General clinic on 4th postoperative day=end of observation. Uncomplicated progression.
Of course, the solutions of the invention may comprise additional substances, such as pharmaceuticals, trace elements soluble and stable Ca and/or Mg compounds.
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Disclosed is a novel therapy involving infusion of specially adapted electrolyte solution comprising essentially physiological concentrations of sodium and other cations and in general higher than physiological concentrations of bicarbonate. The therapy is related to treatment of altered renal function and prophylactic treatment of a patient to resist onset of altered renal function.
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BACKGROUND OF THE INVENTION
The invention relates to a thermal spraying apparatus and also to a thermal spraying process for coating a substrate.
“Thermal spraying” has been established for a long time in the manufacture of single parts and in industrial series production. The most common thermal spraying processes which are in particular also used in series production for the coating of the surfaces of large numbers of substrates are, for example, flame spraying with a spray powder or with a spray wire, arc spraying, high velocity flame spraying (HVOF), detonation spraying or plasma spraying. The above-named list of thermal spraying processes is certainly not exhaustive. On the contrary, the person averagely skilled in the art is familiar with a large number of variations of the listed processes, and of further processes, for example special processes such as flame spray welding.
In this connection thermal spraying has opened up broad areas of use. One can certainly estimate that thermal spraying as a surface coating process is the coating technology with probably the largest area of use with regard to its possibilities of use. Thus a delimitation of the areas of use of the spraying processes listed above does not seem particularly sensible because the areas of use can overlap one another.
In this context the spectrum of use of the different thermal spraying processes ranges from the improvement of the performance of stressed surfaces against mechanical stresses, such as friction for example, against high temperatures, against chemical attacks on the surface to aesthetic use such as for example the improvement of the appearance of objects of personal use. The range of substrates whose surfaces are routinely coated by thermal spraying today is correspondingly broad. Typical examples are parts of all kinds which are subject to wear and tear, components of combustion engines such as the running surfaces of cylinders in petrol or diesel engines, pistons and piston rings of these engines, the application of heat insulation layers onto turbine parts of turbines for use on land or in the air, the coating of hydraulic pistons, kitchen utensils, such as pots or pans, and much more. All materials which can be melted or at least become viscous or melted at the surface by the supply of energy can be considered as spraying material in the form of spray powder or spray wires, for example. Practically all kinds of materials can be coated in this manner, for example wood, glass, ceramics, metals, steels and alloys, but also plastics and textiles.
Special applications very often demand the application of a coating which is constructed from a plurality of individual layers sprayed on top of one another. Thus, by way of example, a coating which is intended to protect a turbine blade against the extreme conditions in the turbine in the operating state can consist of a bond layer or a connecting layer, which guarantees a good connection to the substrate of a layer to be applied. An anti-diffusion layer can be applied on this which prevents a diffusion of alloy components out of the substrate or vice versa for example. A special hard layer can be provided as a further layer of the surface layer which protects against mechanical and chemical attacks in particular and finally a heat insulating layer can be applied as a covering layer, for example on the basis of zirconium oxide for protection against the high temperatures which prevail in the operating state of the turbine.
As the above-named example impressively shows, one of the great advantages of thermal spraying is that a coating can be applied from a layer system of a plurality of individual layers which can be sprayed from completely different materials and thus can also fulfill different functions. Furthermore it is also possible in special cases to combine different thermal spraying processes when applying a layer system, so that a specific layer of the layer system can be applied by means of a plasma spraying process, for example, and another layer of the same layer system, for example a final thermal insulating layer, is sprayed on by means of a HVOF process. It is even possible to combine a thermal spraying process with another coating process, for example with a thin layer process such as PVD (physical vapor deposition) or CVD (chemical vapor deposition) or with an arc vaporization process for example.
A typical example is the application of a dual-layer system with a plasma spraying process wherein the two layers have to be sprayed with two different spray powders. Thus it is known for example to apply a coating to a substrate as protection against wear which additionally has to satisfy certain aesthetic demands. The actual wear protection layer can have excellent wear protection characteristics, for example, and can also, for example, have a gleaming white color following the application, which is desired for aesthetic reasons. However, it can happen that the wear protection layer has very bad adhesive characteristics on the substrate to be coated. Therefore it is current practice, prior to the application of the for example white, aesthetically pleasing wear protection layer, to initially apply a bond layer made of another material directly to the surface of the substrate, i.e. using a different spray material than the spray powder from which the wear protection layer is formed. The spray powder for the bond layer is selected in such a way in this arrangement that, on the one hand, the spray powder has very good adhesive characteristics to the substrate and, on the other hand, so that the white wear protection layer adheres very well to the bond layer. As a result one has a coating comprised of a dual-layer system which as a whole adheres very well to the substrate and on the other hand offers a very good wear protection against mechanical attacks on the surface, with the coated surface simultaneously having an aesthetic white appearance.
A decisive disadvantage in the manufacture of these and other multiple layer systems, in particular in series production using the thermal spraying process known from the prior art and using the known thermal spraying apparatuses used for thermal spraying, is that the spraying procedure has to be interrupted during the coating process, at the transition from the spraying of one individual layer to the spraying of the next layer which has to be sprayed using a different spray material or using a different spraying process. This is because the spray pistol has to be exchanged, in order to change the type of spray pistol, and/or because another spray wire has to be installed. Depending on the specific thermal spraying apparatus or the specific thermal spraying process which is used, it can also be necessary to interrupt the spraying process to spray on a further layer, or to install the substrate in another thermal spraying apparatus, in order to then apply the further layer by means of the other thermal spraying apparatus.
The problems which were explained previously by way of example using the spraying process known from the prior art and the known thermal spraying apparatus lead to a considerable complication of the coating procedure as a whole. This requires additional equipment and results in the tying up of working resources, leading in particular to an increase in the working time during coating and thus to a clear cost increase for the corresponding products.
At least in some cases, i.e. in some quite special cases, namely in cases which relate to the thermal spraying of coatings made of a plurality of individual layers on the surface of a substrate by means of two or more different spray powders, attempts were made to avoid these problems by, for example, providing two or more different feeds in a plasma spraying apparatus which are associated with different powder supplies instead of a single feed for one spray powder.
In the above-named plasma spray apparatus, a plasma beam is produced by means of a plasma spray pistol, into which a spray powder is introduced by means of the feed, which is, for example, melted in the plasma flame of the plasma beam and is thrown onto the surface of a substrate which is to be coated, so that a surface layer made of the material of the spray powder forms on the substrate.
If now, by way of example, two feeds are provided for the spray powder, which can be fed with spray powder from two different spray powder supplies, then it is possible in this way to apply two (or more) different layers one after the other onto the surface of a substrate and thus to form a coating of a multiple layer system without changing the spraying process. A corresponding known thermal spraying process can for example be carried out in the following manner. A shutoff device is provided between the spray powder supplies, in which a certain spray powder is stored for supplying the feeds with spray powder, and the corresponding feed itself, so that the supply of the feed with spray powder can either be enabled or prevented.
To illustrate the process, reference will be made in the following to the dual-layer system already mentioned above, which comprises a bond layer which for example has a black color due to the spray powder used and a wear protection layer applied to this which should have a gleaming white color for aesthetic reasons.
For the application of this dual-layer system by means of a plasma spraying apparatus, a plasma flame is ignited initially in a spray pistol which is directed towards the substrate which is to be coated, so that spray powder which has been introduced into the plasma flame and sintered by the plasma flame is thrown onto the surface of the substrate to form a layer.
For the formation of the dual-layer system, the connection between the spray powder supply which contains the spray powder for the formation of the white wear protection layer is first interrupted so that no spray powder for the formation of the wear protection layer can be supplied to the corresponding feed. However the connection between the feed and the powder supply which contains the spray powder for formation of the bond layer is open, so that the powder for the formation of the bond layer can be supplied to the plasma flame.
By this means in a first process step, the bond layer can initially be applied to the substrate. When the application of the bond layer is complete the feeding of the spray powder to the feed from the spray powder supply is discontinued, so that no further spray powder can any longer be supplied to the corresponding feed from this powder supply.
Thereafter the connection is established between the feed which is associated with the powder supply which contains the spray powder for the formation of the white wear protection layer and the powder supply so that the spray powder for the formation of the white wear protection layer is supplied to the plasma flame and correspondingly the white wear protection layer can be applied on the previously applied black bond layer. Thus it is indeed possible using this apparatus known from the prior art to spray a dual- or multi-layer system using different spray powders, without interrupting the spraying process, i.e. without switching off the plasma flame and/or exchanging a feed for the spray powder and/or installing the substrate into another plasma spraying apparatus for the formation of a second layer.
A considerable disadvantage of this known plasma spraying apparatus is however that in a spray powder feed itself or in a connection line between a spray powder supply and the feed even after an interruption of the connection between the spray powder supply and the associated feed the remains of the corresponding spray powder still exist. The result of this is that by means of the considerable negative pressure which the plasma flame produces, these remnants of the spray powder are sucked out of the feed during further spraying together with another spray powder which is supplied to the plasma flame as described above from another feed for the spraying of a further layer, and thus the spray powder, which is actually intended for the formation of a further layer, is contaminated. This means that the further layer contains certain constituents of the spray powder which were actually intended solely for the formation of a first layer.
It is obvious that pollutants such as these can have considerable negative consequences. If for example pollutants are introduced into the white wear protection layer described above by that powder which should actually only form the black bond layer, the white covering layer will not have the lovely aesthetic white color but rather be dyed more or less grey or contain black spots. If aesthetic qualities play a certain role in a product, then a product with a surface which has been polluted in this manner is of course unusable and has to be rejected.
However pollutants in a layer can also lead to a clear deterioration of the mechanical, chemical, physical or thermal characteristics of the polluted layer. Even small amounts of pollutants can, in special cases, lead to certain layer characteristics deteriorating so dramatically that the coating as a whole no longer has the desired characteristics and the coated part is unusable and has to be rejected.
SUMMARY OF THE INVENTION
It is an object of the present invention to make available an improved thermal spraying apparatus and also an improved thermal spraying process using multiple layer systems which can be applied to a substrate, with the disadvantages known from the prior art being overcome.
The invention thus relates to a thermal spraying apparatus for coating a surface of a substrate by means of a coating material. The thermal spraying apparatus includes a spray pistol with a heating device for heating up the coating material in a heating zone and also a charging apparatus with a feed through which the coating material can be introduced into the heating zone. In this arrangement the thermal spraying apparatus is designed in such a manner that a relative position between the feed and the heating zone can be altered in the operating state.
Due to the fact that the relative position can be altered in the operating state between the feed and the heating zone, in which a spray powder which has been brought via a feed can be heated, a feed can be removed from the range of influence of the plasma flame when it is no longer needed for the supply of a spray powder in a second coating procedure following a first coating procedure, so that powder can no longer be sucked out of the no longer needed feed due to the suction action of the plasma flame. Thus, for example, a subsequent layer which may have to be sprayed with another spray powder can no longer be polluted by the powder which was used to spray the previous layer.
Thus, multi-layer systems made of different materials can be applied to a substrate in a particularly simple and efficient manner, without the spraying procedure having to be interrupted during the change from spraying a first layer of a layer system to be applied to the spraying of a further layer using a different spray powder in such a way that a feed for the spray powder is changed and/or that the substrate for applying a further layer onto a first sprayed layer has to be installed into another spraying apparatus.
In a preferred embodiment of a thermal spraying apparatus, the heating device of the thermal spraying apparatus is a plasma burner and/or a heating device for flame spraying and/or a heating device for detonation spraying and/or another thermal heat source. This means that the thermal spraying apparatus in accordance with the invention which is to be explained in the following can essentially be carried out using all known thermal spraying processes; i.e. the type of heating device and thus the type of the spraying pistol which a thermal spraying apparatus in accordance with the invention includes can be any of the spraying pistols or heating devices known from the prior art. Thus the spraying apparatus in accordance with the invention or the process in accordance with the invention can be employed universally and is suitable for applying practically any conceivable thermal coating using any desired spraying material, no matter whether spraying powder or spraying wire or a spraying material in a different form is applied onto a substrate, which can be made of any kind of material at all.
In an embodiment which is particularly important for industrial practice, the thermal spraying apparatus is designed in such a way in this arrangement that the feed is arranged to be movable in relation to the heating device. This can, for example, be realized in that the spray pistol itself has a position in relation to the spraying apparatus per se which cannot be altered in the operating state, whereas a position of the feed in relation to the heating zone, in other words for example in relation to the position to the plasma flame of a plasma spraying pistol, can be altered. For this purpose, in a special embodiment, the feed can, for example, be mounted on a movable carriage which is displaceable in relation to the heating zone which is, for example, defined by the plasma flame of a plasma spray pistol.
Preferably but not necessarily, as will be explained later on with a special example, at least a first feed and a second feed are provided, with at least the first feed, in a special case the first and second feeds, being arranged to be movable in relation to the heating device. In this arrangement a first coating material can be fed via the first feed and a second coating material can be fed via the second feed. An arrangement such as this allows the spraying of two or more different layers of a coating system using two or more different spray powders one after the other onto a substrate in a very efficient manner, without having to interrupt the spraying procedure as a whole and without resulting in a mixing or contamination of the different spray powders. Thus with the first feed, a first spray powder can be transported into the heating zone for spraying a first layer. When the first layer is finished, the first feed can be moved away from the range of influence of the heating zone and a second, different spray powder, for spraying a second layer onto the first layer, can be introduced into the heating zone via the second feed, without fear of a contamination of the second spray powder with the first spray powder. It is also conceivable that the second feed is only moved into the range of influence of the heating zone after the first feed has been removed from the range of influence of the heating zone. Different variants can be preferred depending on the spraying procedure used or the demands on the layer to be sprayed or the design of the coating processes as a whole and the nature of the actual spraying apparatus used.
In a further special embodiment of a thermal spraying apparatus in accordance with the invention, the heating device is movably arranged in relation to the feed. This means that as an alternative to the embodiment explained previously it is, for example, also possible for two different feeds to be present, which are, for example, connected to two different spray powder stores for the delivery of spray powder, with the position of the two feeds in relation to the thermal spraying apparatus as such being fixed in the operating state. In this case the spray pistol is movably arranged in relation to its position to the two feeds. The spray pistol can be arranged on a movable carrier for example, so that the spray pistol is arranged in relation to the first feed for spraying in such a way that a first spray powder can be introduced into the heating zone via the first feed and the spray pistol is displaced by movement of the movable carrier in such a way that spray powder from the second feed can be introduced into the heating zone, while the first feed is no longer located in the range of influence of the heating zone. In an apparatus such as this it is possible to spray two different layers onto a substrate next to each other without interrupting the spraying procedure per se. In a preferred variant of the embodiment explained above, the substrate is moved in synchronism with the spray pistol, by suitable coupling to the displacement of the spray pistol, so that two layers can also be sprayed one on top of the other.
It is also possible, in another embodiment of a thermal spraying apparatus in accordance with the invention, for at least one second heating device to be provided in addition to a first heating device and for at least the first heating device to be movably arranged in relation to one feed, and preferably for both to be movable in relation to one feed. In this way it is possible to apply different layers to one substrate using different types of spray pistols and/or using different spray powders.
In particular, for example, in an apparatus in accordance with the invention, when a substrate is to be provided with different layers alternately using a spray pistol for flame spraying or for HVOF spraying and a plasma spray pistol, a layer can first be applied by means of flame spraying and a second layer can be applied by means of plasma spraying. Since in the known apparatuses for flame spraying or for HVOF spraying the powder feed takes place as a rule axially via the feed and not radially from the outside, the feeds are, for example, swung out of the range of influence of the heating zone during the coating step by means of flame spraying, since the feeds are not required during flame spraying. When the coating step by means of flame spraying is complete, the spray pistol for flame spraying is exchanged for a plasma spray pistol and the feed for conducting the spray powder into the melting zone is swung correspondingly in the direction of the melting zone, which is produced by the plasma spray pistol. A cleaning unit can be further provided so that, if necessary, a feed for the spray powder can be moved out of the range of influence of the heating zone so that the feed can be cleaned by the cleaning unit, as is sufficiently familiar to the person averagely skilled in the art, so that the feed is again put into an ideal condition for a subsequent coating procedure.
It goes without saying from the above explanations that either the feed and/or the heating device and/or the cleaning unit are jointly movably arranged by means of a drive or are respectively individually linearly movably arranged relative to one another.
In this arrangement the relative movement of the previously named components of a thermal spraying apparatus in accordance with the invention does not have to be a linear movement. Depending on the circumstances or the special requirements placed on the spraying conditions, the path of the relative movement towards one another can also be more complicated than simply linear. Thus the feed and/or the heating device and/or the cleaning unit can, for example, be rotatably arranged relative to each other by means of a drive, which can be of advantage in particular when during a spraying procedure changes should be made between more than two different spray powders, and/or when changes should be made between more than two different types of spray pistol.
In this arrangement the drive for producing the relative movement can be a pneumatic drive and/or a hydraulic drive and/or a magnetic drive and/or an electrical drive, in particular a linear motor or a rotary machine or of any other kind.
The invention further relates to a thermal spraying process to be carried out in one of the thermal spraying apparatuses described above, with a surface of a substrate being coated with a coating material by means of a thermal spraying apparatus, including a spray pistol with a heating device and a charging apparatus with a feed, with the coating material being introduced via the feed into the heating zone and being heated in the heating zone by the heating device and with the relative position between the feed and the heating device being changed in the operating state.
The invention will be explained in more detail with the help of the drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 a shows a thermal spraying apparatus known from the prior art;
FIG. 1 shows an embodiment of a thermal apparatus made in accordance with the invention with a movably arranged feed;
FIG. 2 shows a different embodiment in accordance with FIG. 1 with rotatably arranged feeds;
FIG. 3 shows a third embodiment with pivotably arranged feeds; and
FIG. 4 shows an embodiment with a movably arranged spray pistol.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Before a few embodiments of thermal spraying apparatuses in accordance with the invention are explained further with the help of the drawings, a typical arrangement of a thermal spraying apparatus 1 ′ known from the prior art will be explained with reference to FIG. 1 a as briefly as possible for the sake of clarity. The features known from the prior art are characterized in this arrangement by reference numerals with dashes.
A typical known thermal spraying apparatus 1 ′ includes, as illustrated schematically in FIG. 1 a , essentially a spray pistol 5 ′, which has a heating device, for example a plasma burner, which makes available a plasma flame in the region of a heating zone 6 ′. A feed 8 ′ is fixed to the spray pistol 5 ′ by means of a powder injector holder 12 ′, the feed 8 ′ being connected to a powder supply 10 ′, which contains coating material 4 ′, for example spray powder 4 ′, which can be conducted to the heating zone 6 ′ by means of the feed 8 ′, so that the coating material 4 ′ can be heated in the heating zone 6 ′ and then can be applied to the substrate 3 ′ for the formation of a layer. Characteristic for the known thermal spraying apparatus 1 ′ in this arrangement is that the relative position 9 ′ between the feed 8 ′ and the heating zone 6 ′ remains unaltered, at least during a complete spraying procedure which is symbolized by the point with the reference numeral 9 ′.
FIGS. 1-4 explained in the following correspond from the point of view of the type of illustration to a vertical section in accordance with the type of illustration of FIG. 1 a . However FIGS. 1-4 are illustrations of thermal spraying apparatuses in accordance with the invention and do not represent the prior art like FIG. 1 a.
FIG. 1 shows, in schematic illustration, a thermal spraying apparatus in accordance with the invention which will be given the reference numeral 1 in the following.
This embodiment, which is particularly important in practice, is particularly suitable, for example, to spray on a coating made of two layers using two different spray powders 4 , 41 , 42 onto a surface 2 of a substrate 3 one after another and one over the other. In the arrangement illustrated in FIG. 1 the substrate 3 is coated in turn with a spray powder 41 and a spray powder 42 for the formation of a two-layer system.
Two containers 10 , a first container 101 and a second container 102 , are provided as spray powder supplies 10 , 101 , 102 , which contain two different spray powders 4 , a first spray powder 41 and a second spray powder 42 , for spraying two different layers. The container 101 is connected to the first feed 81 via a first lead 111 , so that the first spray powder 41 can be brought into a heating zone 6 via the first feed 81 . Analogue to this the second feed 82 is connected to the second container 102 via the second lead 112 so that when the second feed 82 is located in the region of the heating zone 6 , the second spray powder 42 can be brought into the heating zone for spraying a second layer. A cut-off valve 131 , 152 is respectively provided in the leads 111 , 112 so that the powder supply from the containers 41 , 42 to the corresponding feeds 81 , 82 can either be stopped by closing of the cut-off valve 131 , 152 or can be made possible by opening of one of the cut-off valves 131 , 152 . The two cut-off valves 81 , 82 are provided together on a movable rail which will be referred to generally in the following as the powder injector holder 12 . The fact that the powder injector holder 12 is displaceable is shown symbolically by the double arrow 9 . As shown in FIG. 1 , the substrate 3 is coated with a first layer using the spray powder 41 . When the coating procedure, i.e. the coating with the spray powder 41 , has been completed, the powder injector holder is displaced towards the left-hand side along the double arrow 9 in accordance with the drawing, by means of a drive not shown in FIG. 1 , until the feed 82 is positioned in such a way that spray powder 42 can be brought into the melting zone 6 by means of the feed 82 . Thus a second layer can then be sprayed onto the first layer which was sprayed on with the spray powder 41 without fear of a pollution of the second spray powder 42 by the first spray powder 41 . While one of the layers is sprayed onto the substrate, a cleaning unit 20 can be used to clean the feed that is positioned away from heating zone 6 .
Another embodiment in accordance with FIG. 1 with rotatably arranged feeds is illustrated schematically in FIG. 2 .
In the embodiment illustrated here, three different feeds 8 , namely a first feed 81 , a second feed 82 and a third feed 83 , are provided which are arranged on a powder injector holder 12 which is essentially formed as a circular ring. The substrate 3 can be coated with at least three different layers one after the other by means of the thermal spraying apparatus 1 shown in FIG. 2 . It is of course possible, without any problems, to provide more or less than three feeds 8 on the circular powder injector. This also applies to the powder injector holder 12 in accordance with FIG. 1 in just the same way. In principle the coating procedure functions with the thermal spraying apparatus 1 in accordance with FIG. 2 analogously to that as already explained at length in the description of FIG. 1 . The essential difference is to be found in the fact that the changing from one feed 8 , for example of the first feed 81 , to another feed 82 or 83 takes place by means of a rotary movement of the powder injector holder 12 about a rotational axis 14 , as symbolized by the double arrow 9 , and not by means of a linear movement as in the powder injector holder in accordance with FIG. 1 .
A third embodiment with pivotably arranged feeds is illustrated in FIG. 3 . This spraying apparatus 1 is also suitable for coating the substrate 3 with two different spray powders 41 , 42 one after the other. The essential difference is merely that the changing of the feeds 81 , 82 takes place due to the fact that the feeds 81 , 82 can be pivoted, preferably simultaneously, about respective pivot axes 14 , as is shown symbolically by the double arrow 9 . This means that, for example when a first layer has been sprayed with a spray powder 41 from the container 101 onto the surface 2 of the substrate 3 , the feed 81 is swivelled away out of the range of the heating zone 6 to the left-hand side about the axis 141 in accordance with the drawing and the feed 82 is swivelled about the axis 142 into the range of the heating zone 6 . The valves 13 which regulate the supply of the spray powder 41 , 42 are opened or closed, precisely as has already been described above for the two other embodiments.
Finally an embodiment of a spraying apparatus 1 in accordance with the invention with movably arranged spray pistols 5 , 51 , 52 is shown in FIG. 4 . This special embodiment is particularly suitable when, for example, two layers are to be applied using one and the same spray powder with two different spray pistols. It is well known that layers with different characteristics can be sprayed using one and the same spray powder by using different spray pistols which work with different spraying parameters or according to different processes. Thus the spray pistol 51 shown schematically in FIG. 4 can be a Sulzer Metco F4-MB plasma spray gun for example while the spray pistol 52 is a Sulzer Metco Triplex II plasma spray gun. Layers of considerably higher quality can be sprayed using the latter for example, so that an optimum surface is achieved while a bond layer is, for example, sprayed on using the F4-MB plasma spray gun, for which fewer demands are made with regard to its surface, since this is subsequently covered by the very high quality layer, sprayed with the Triplex spray pistol 52 . Whereas the two above-named types of spray pistol 5 are both plasma spray pistols 5 , the two spray pistols 51 , 52 could also be two spray pistols which work according to different principles. Thus for example the spray pistol 51 can be a flame spray pistol or a wire spray pistol 52 . It goes without saying that any other combination of types of spray pistols 5 is also possible.
In the embodiment shown in FIG. 4 , in contrast to the embodiments explained with the help of FIGS. 1-3 , a substrate 3 which is to be coated is positioned in front of a feed 8 , with a first spray pistol 51 being exchangeable for a second spray pistol 52 during a spraying procedure.
Here the two spray pistols 51 , 52 are mounted on a movable spray pistol holder 15 which can be displaced during the spraying procedure in the direction of the double arrow 9 to change the spray pistols, so that one after the other, a layer can be sprayed on first, using the spray pistol 51 and after this a second layer can be sprayed on using the spray pistol 52 . It goes without saying that analogously to the embodiments in accordance with FIG. 2 and FIG. 3 , the spray pistols 51 , 52 can also be mounted on an annular spray pistol holder 15 , or that the spray pistols 51 , 52 can also be arranged to be pivotable. Of course more than two of the same or different spray pistols can also be provided on a spray pistol holder 15 in order to be able to spray more than two different layers onto a substrate 3 .
It is clear that the embodiments which have been explained in more detail above can also be combined in any suitable manner. This means that thermal spraying apparatuses 1 are in particular possible in which a plurality of the same or different types of spray pistols 5 can be provided, as well as one or more different feeds 8 , which are movable relative to one another separately or jointly, so that layer systems can be sprayed from different spray powders and/or according to different spraying processes such as, for example, plasma spraying, wire spraying, HVOF, etc.
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The invention relates to a thermal spraying apparatus ( 1 ) for coating a surface ( 2 ) of a substrate ( 3 ) by means of a coating material ( 4 ). The thermal spraying apparatus ( 1 ) includes a spray pistol ( 5 ) with a heating device for heating the coating material ( 4 ) in a heating zone ( 6 ) and also a charging apparatus ( 7 ) with a feed ( 8 ) through which the coating material ( 4 ) can be introduced into the heating zone ( 6 ). In this arrangement the thermal spraying apparatus is so designed that a relative position ( 9 ) between the feed ( 8 ) and the heating zone ( 6 ) can be changed in the operating state.
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CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] The present application is the U.S. national phase of International Application No. PCT/EP2014/075901 filed Nov. 28, 2014, which claims priority of German Application No. 10 2013 224 412.6 filed Nov. 28, 2013, the entirety of which is incorporated herein by reference.
FIELD OF THE INVENTION
[0002] The invention relates to a method for investigating a sample, derived from a biological source, using CARS microscopy, in which method a resonance signal generated by coherent anti-Stokes Raman scattering by excitation of at least one resonance site of the sample by means of laser irradiation is sensed in image-producing fashion.
BACKGROUND OF THE INVENTION
[0003] “Nonlinear Raman spectroscopy” is understood to mean spectroscopic investigation methods that are based on nonlinear Raman scattering of light at solids or gases. The present invention refers to microscopic investigation methods based on coherent anti-Stokes Raman scattering (CARS).
[0004] For investigation methods of this kind (also referred to as “CARS microscopy”), two lasers that emit light of different wavelengths (v P and v S , the pump and Stokes light beams), where v S should be tunable, are used to generate a CARS spectrum v CARS : v CARS =2v P −v S , I CARS ≈(I P ) 2 −I S .
[0005] FIG. 2 schematically depicts a term diagram of a CARS transition. If the frequency difference v P −v S matches the frequency difference between two molecular vibration states |1> and |0> in an investigated sample, the CARS signal becomes amplified. Structures of a sample in which different molecular states of this kind occur and are also correspondingly detectable (typically, characteristic chemical bonds) are referred to hereinafter as “resonance sites.” Corresponding structures of a molecule, or molecules in general that contain them, are also referred to as “scatterers.”
[0006] The pump light beam and Stokes light beam are coaxially combined for microscopy applications, and are focused together onto the same sample volume. The direction in which the anti-Stokes radiation is emitted is determined from the phase adaptation condition for the underlying four-wave mixing process, as depicted schematically in FIG. 3 .
[0007] Methods and apparatuses for CARS microscopy are known, for example, from DE 102 43 449 A1 (simultaneously U.S. Pat. No. 7,092,086 B2), which describes a CARS microscope having means for generating a pump light beam and a Stokes light beam that are directable coaxially through a microscope optical system onto a sample, and having a detector for detecting corresponding detected light.
[0008] Further physical principles of CARS microscopy may be gathered from current reference works (see e.g. Xie, X.S., et al., Coherent Anti-Stokes Raman Scattering Microscopy, in: J. B. Pawley (ed.), Handbook of Biological Confocal Microscopy, 3rd edition, New York, Springer, 2006).
[0009] As compared with conventional or confocal Raman microscopy, in CARS microscopy it is possible in particular to achieve higher detected light yields and better suppression of obtrusive secondary effects. The detected light furthermore can be more easily separated from the illuminating light.
[0010] Because, as mentioned, characteristic natural vibrations of the molecules in a sample, or of specific chemical bonds, can be used in CARS microscopy, it allows species-selective imaging that in principle dispenses with further tagging and dyes. With CARS microscopy, molecular structure information about a sample can be obtained with three-dimensional spatial resolution.
[0011] CARS microscopy always relies, however, on the presence of corresponding resonance sites in the sample. If resonance sites are absent or if, for structures of interest, the frequency differences of their vibration states are not sufficiently distinguished from those of the surroundings, they cannot be detected. In addition, with known methods for CARS microscopy it is often difficult to suppress the non-resonant background.
[0012] Picosecond laser pulses can be used, for example, to manipulate or decrease the non-resonant background, but they require the use of correspondingly complex lasers. Further possibilities for reducing the non-resonant background are so-called “epi-detection” and polarization-sensitive detection. Time-resolved methods are also utilized in this context. A further possibility is to control the phase of the excitation pulses.
[0013] The aforesaid methods nevertheless prove to be more or less cumbersome in practice. Selective accentuation of defined structures in a sample can also be desirable in certain cases, but this is not possible in conventional methods for CARS microscopy.
SUMMARY AND ADVANTAGES OF THE INVENTION
[0014] The present invention aims to provide a remedy here, and its object is to furnish a correspondingly improved method for CARS microscopy.
[0015] This object is achieved by a method for investigating a sample, derived from a biological source, using CARS microscopy, in which method a resonance signal generated by coherent anti-Stokes Raman scattering by excitation of at least one resonance site of the sample by means of laser irradiation is sensed in image-producing fashion, wherein the method comprises furnishing at least one resonance site by means of a bioorthogonal reaction of an intrinsic chemical structure of the sample with at least one reaction partner.
[0016] Preferred embodiments are the subject matter of the description below.
[0017] The present invention proceeds from a known method for CARS microscopy. A method of this kind encompasses the investigation of a sample derived from a biological source, in which method a signal generated by coherent anti-Stokes Raman scattering by excitation of resonance sites in the sample by means of laser irradiation is sensed in image-producing fashion, and in which structural properties of the chemical structures containing the resonance sites can also optionally be derived from the signal.
[0018] When a “sample derived from a biological source” is referred to in the context of the present invention, this can involve a sample removed directly from a biological system, for example an animal tissue sample, a plant structure, and/or a prepared specimen derived therefrom. The present invention can also be utilized, however, in more or less highly processed samples, for example in food chemistry. The present invention is especially suitable, for example, for purity checking, for example of oils.
[0019] The invention is of course particularly suitable for tagging in biological samples, for example nerve tissue, in which the intelligence of a tag can be combined with the specificity of vibrational spectroscopy. It thus becomes possible, for example, simultaneously to check lipids for tags and to process them in image-producing fashion; these could previously only be sensed separately.
[0020] The structural properties of the chemical structures encompassing the resonance sites can be derived in known fashion from the signal generated by coherent anti-Stokes Raman scattering. A corresponding signal, which for example can also be obtained in the form of spectra when tunable Stokes light beams are used, contains features, for example corresponding wavelengths, bands, and/or peaks, that are specific for the respectively contained resonance sites, in particular the respective chemical bonds. These are indicated as Raman shifts or CARS shifts (which correspond to the frequency differences between the respective molecular vibration states), typically in the form of wave numbers. One skilled in the art may gather characteristic wavelengths obtained for chemical bonds from relevant reference works.
[0021] The present invention is also suitable for the use of Stokes light beams of fixed wavelength. Although spectra are not acquired in this case, the signal generated by coherent anti-Stokes Raman scattering can be used in this case as well for image production.
[0022] A method of this kind thus encompasses, according to the present invention, the furnishing of at least one resonance site by means of a bioorthogonal reaction of an intrinsic chemical structure of the sample with at least one further reaction partner, i.e. the introduction, by way of a bioorthogonal reaction, of a corresponding structure that is not inherently contained in the sample.
[0023] The term “bioorthogonal reaction” will be further explained in detail below. The term “intrinsic chemical structure” is understood here as a chemical structure that is already contained in the sample as a result of its origin. In samples deriving from biological sources this refers, for example, to aliphatic chains having corresponding bonds in lipids, peptide bonds in proteins, and the like. Intrinsic chemical structures of this kind comprise resonance sites that can be sensed in image-producing fashion using CARS microscopy.
[0024] In contrast to such intrinsic resonance sites, or the chemical structures on which they are based, resonance sites introduced according to the present invention into a sample are those that the sample does not comprise based on its natural origin. The invention thus makes it possible to equip a sample that inherently does not possess, or does not possess sufficient, resonance sites, or in which the resonance sites do not exhibit the desired localization or specificity, with corresponding resonance sites.
[0025] According to the present invention provision can be made either that the at least one resonance site is at least partly part of the at least one further reaction partner, and/or that said site is generated at least partly by the bioorthogonal reaction itself. The former case corresponds fundamentally to conventional staining reactions and/or tagging reactions with fluorescent dyes. Here, as a rule, a fluorescent or color-imparting structure is furnished in a corresponding molecule, and is coupled to reactive structures of the sample. In contrast thereto, however, utilization of the method according to the present invention also makes it possible to generate resonance sites in the context of performance of the bioorthogonal reaction itself.
[0026] This can be accomplished, for example, by cycloaddition of a conjugated diene to a dienophile (which can have a double or triple bond), as illustrated below:
[0000]
[0000] If, for example, the residue Y is used here as a coupling site, it is possible to generate, for addition and complete reaction of a suitable diene, a structure that is depicted on the right in the reaction equation above and exhibits, because of its specific properties, a well-defined CARS pattern to which a subsequent detection process can be matched.
[0027] As mentioned, the method according to the present invention can also be used in particular to highlight or make visible chemical structures normally not detectable by means of CARS microscopy.
[0028] The present invention makes it possible in particular, once the resonance sites have been created by means of the bioorthogonal reaction, to use small molecules that can be introduced deep into a corresponding tissue, since no steric hindrance occurs and, for example, they diffuse through a tissue. This is a substantial advantage in the context of the use of bioorthogonal reactions as compared with conventional staining techniques, for example using fluorescent dyes. This type of introduction into tissue is of particular interest because, as mentioned, three-dimensional image production is possible by means of CARS microscopy.
[0029] As mentioned, the present invention is based on the use of bioorthogonal chemical reactions. “Bioorthogonal reactions” are understood in the context of the present Application as chemical reactions that can proceed in living systems without appreciably interfering with natural processes. Bioorthogonal reactions can in particular proceed with no cell-damaging effects.
[0030] The term “bioorthogonality” and the chemical reactions relevant here are known to those skilled in the art (see E. M. Sletten and C. R. Bertozzi, “Bioorthogonal chemistry, or: Fishing for selectivity in a sea of functionality” [Bioorthogonale Chemie-oder: in einem Meer aus Funktionalität nach Selektivität fischen], Angew. Chem. 121 (38), 7108-7133, 2009, concurrently E. M. Sletten and C. R. Bertozzi, “Bioorthogonal Chemistry: Fishing for Selectivity in a Sea of Functionality,” Angew. Chem. Int. Ed. Engl. 48 (38), 6974-6998, 2009). An overview is also provided by K. V. Reyna and Q. Lin, “Bioorthogonal Chemistry: Recent Progress and Future Directions,” Chem. Commun. (Camb.) 46(10), 1589-1600, 2010.
[0031] Typical bioorthogonal reactions encompass, for example, 1,3-dipolar cycloaddition between azides and cyclooctynes (so-called “copper-free click chemistry,” see J. M. Baskin et al., “Copper-Free Click Chemistry for Dynamic In Vivo Imaging,” Proc. Natl. Acad. Sci. USA 104 (43), 16793-16797, 2007). Other typical reactions are the reaction between nitrones and the aforesaid cyclooctynes, oxime/hydrate formation from aldehydes and ketones, tetrazine reactions, isonitrile-based click reactions, and quadricyclane formation.
[0032] A Diels-Alder reaction and/or a Staudinger ligation are considered particularly advantageous for use in the bioorthogonal reaction according to the present invention. Staudinger ligation is a highly chemoselective method for producing bioconjugates. The respective reaction partners are bioorthogonal to almost all functional groups present in biological systems, and already react in an aqueous environment at room temperature. This allows Staudinger ligation to be used even in the complex surroundings of a living cell. Reference is made, regarding details, to the relevant technical literature (see e.g. S. Sander et al., “Staudinger Ligation as a Method for Bioconjugation,” Angew. Chem. Int. Ed. Engl. 50 (38), 8806-8827, 2011).
[0033] The use of bioorthogonal reactions typically encompasses two steps. Firstly a cellular substrate, i.e. in this case the sample to be investigated, is equipped with a bioorthogonal functional group that is introduced into the sample and is also referred to as a “chemical reporter.” Substrates that are used include, for example, metabolites, enzyme inhibitors, etc., and in the context of the present invention all compounds or tissues that are to be tagged and for which improved visualization in CARS microscopy is desired. The bioorthogonal functional group, also referred to as a chemical reporter, must not substantially modify the structure of the sample, so as not to negatively affect bioactivity. In a second step a tagging substance, having a complementary functional group that reacts with the chemical reporter, is introduced.
[0034] The use of bioorthogonal reactions in combination with CARS microscopy makes possible dedicated detection of target sites in any samples, for example in cells, without negatively affecting biochemical processes that may continue to occur. Subsequently thereto, the tagging reaction causes the actual synthesis or introduction of the “active” substance for CARS image production.
[0035] This method allows the CARS-active scattering cross section of the respective target to be increased, or to be generated in the first place by suitable synthesis reactions. A corresponding method combines, by way of chemical image production, the advantage of known multi-photon techniques with a corresponding selective reaction. Especially as compared with the conventional use of fluorescent dyes as image-producing elements (e.g. for single-photon methods), target sites located deeper in the tissue can be utilized for image production thanks to the advantageous steric properties of the compounds used in the bioorthogonal reactions.
[0036] A further advantage that can be obtained by way of the features proposed according to the present invention is, as mentioned, a reproducible counter-staining of the non-resonant background in the context of CARS microscopy.
[0037] As mentioned, CARS methods generally take into account a non-resonant background that can conventionally also be used as a “counter-stain.” This has the disadvantage, however, that the background is statistical. With the features proposed according to the present invention, on the other hand, a defined background can be introduced by way of a corresponding actively performed “counter-stain,” so that specific molecules can be targeted and the resulting image can be correlated with the background that has been generated. This enables an improvement in the reproducibility of corresponding CARS methods, as well as improved quantitative conclusions.
[0038] As is generally known, conventional Raman methods are not overly sensitive and require strong Raman scatterers. CARS microscopy is substantially more sensitive, although it cannot be used like Raman spectroscopy in highly specific complex substance mixtures. In some circumstances this lower specificity is not sufficient for the task on which the investigative method is based. The invention, on the other hand, allows a corresponding increase in specificity and additionally an increase in scattering cross section when the latter is necessary.
[0039] Particularly advantageous examples of bioorthogonal reactions in the context of the present invention encompass at least one reaction step in the form of a modified Huisgen cycloaddition, a nitrone dipolar cycloaddition, a norbornene cycloaddition, a (4+1) cycloaddition, and/or an oxanorbornadiene cycloaddition.
[0040] The aforementioned copper-free click reactions are particularly suitable for use in the context of the present invention, for example utilizing cyclooctynes. The cyclooctynes are, for example, coupled to an azide group that can in turn be introduced into a corresponding sample as a first reaction partner. Azide groups are bioorthogonal in particular because they are small, and can thus penetrate easily into the corresponding tissue and not produce any steric changes. Azides do not occur in natural samples, so that no competing secondary biological reactions exist (see M. F. Debets et al., “Azide: a unique dipole for metal-free bioorthogonal ligations,” Chembiochem. 11(9), 1168-84, 2010). Cyclooctynes are larger, but they have sufficient stability and orthogonality that they too are suitable for in vivo tagging.
[0041] A tetrazine reaction, a tetrazole reaction, and/or a quadricyclane reaction can also, in particular, be used in the context of the present invention as at least one reaction step of the bioorthogonal reaction. Such reactions are also known in principle.
[0042] As already explained repeatedly, the at least one intrinsic structure of the sample can firstly be coupled to a first reaction partner, and the reaction partner coupled to the intrinsic structure of the sample can then be coupled to a further reaction partner. Any reaction partner can encompass the resonance site, or the latter can be formed only by a reaction among any two or more reaction partners.
[0043] A method in which a structure of the sample which does not intrinsically have a resonance site is equipped with a resonance site by means of the bioorthogonal reaction is regarded as particularly advantageous. As explained, this relates in particular to the inherently non-resonant background, which in conventional methods yields statistical signals that are nevertheless not reproducible. The invention, conversely, makes it possible to tag the non-resonant background with corresponding resonance sites and thus to generate a stable, reproducible background signal. The latter is advantageously generated by selecting suitable compounds in such a way that it stands out in contrasting fashion from the structures that are actually of interest, for example exhibits peaks at distinctly different wavelengths.
[0044] A corresponding method can encompass furnishing resonance sites for the structures of the non-resonant background of the sample, and correlating a signal component of the resonance signal attributable to those resonance sites with a signal component attributable to intrinsic resonance sites of the sample.
[0045] It is understood that the features recited above and those yet to be explained below are usable not only in the respective combination indicated, but also in other combinations or in isolation, without departing from the scope of the present invention.
[0046] The invention is schematically depicted in the drawings on the basis of an exemplifying embodiment, and will be described in detail below with reference to the drawings.
DESCRIPTION OF THE FIGURES
[0047] FIG. 1 schematically illustrates a CARS microscope that can be used in a method according to an embodiment of the invention.
[0048] FIG. 2 shows a term diagram of a CARS transition that can be the basis of an embodiment of the invention.
[0049] FIG. 3 illustrates a four-wave mixing process that can be the basis of an embodiment of the invention.
[0050] FIG. 4 illustrates a method according to an embodiment of the invention in accordance with a schematic diagram.
[0051] FIG. 5 illustrates a method according to an embodiment of the invention in accordance with a schematic diagram.
[0052] FIG. 6 illustrates a method according to an embodiment of the invention in accordance with a schematic flow chart.
[0053] In the Figures, elements that correspond to one another are labeled with identical reference characters and are not repeatedly explained.
DETAILED DESCRIPTION OF THE INVENTION
[0054] FIG. 1 shows a microscope, embodied as confocal scanning microscope 100 , that contains a laser 101 for generating a light beam 102 of a first wavelength of, for example, 800 nm. Laser 101 can be embodied as a mode-coupled titanium-sapphire laser 103 . Light beam 102 is focused with an incoupling optic 104 into the end of a, for example, microstructured optical element 105 for wavelength modification, which element can be embodied as a light-guiding fiber made of photonic band gap material 106 .
[0055] An outcoupling optic 108 is provided, for example, in order to collimate the wavelength-broadened light beam 107 that emerges from the light-guiding fiber made of photonic band gap material 106 . The spectrum of the correspondingly wavelength-modified light beam is as a result, for example, almost continuous over the wavelength region from 300 nm to 1600 nm, the light power level being largely constant over the entire spectrum.
[0056] Wavelength-broadened light beam 107 passes through a suppression means 108 , for example a dielectric filter 109 , that, in wavelength-broadened light beam 107 , reduces the power level of the light component in the region of the first wavelength to the level of the other wavelengths of wavelength-broadened light beam 107 . Wavelength-modified light beam 107 is then focused, for example with an optic 110 , onto an illumination pinhole 111 , and then arrives at a selection means 112 that is embodied as an acousto-optical component 113 and functions as a main beam splitter. A pump light beam 114 and a Stokes light beam 115 , each having a wavelength defined by a user, can be selected with selection means 112 .
[0057] From selection means 112 , pump light beam 114 and Stokes light beam 115 , which proceed coaxially, travel to a scanning mirror 116 that guides them through a scanning optic 117 , a tube optic 118 , and an objective 119 and over a sample 1 . Detected light 120 emerging from sample 1 , which light is depicted in the drawing with dashed lines, travels (when, for example, descanned detection is provided) back through objective 119 , tube optic 118 , and scanning optic 117 to scanning mirror 116 and then to selection means 112 , passes through the latter, and after traversing a detection pinhole 121 is detected with a detector 122 that is embodied as a multi-band detector. When, for example, non-descanned detection is likewise provided, two further detectors 123 , 124 can be provided on the condenser side. Detected light 125 emerging in a straight-ahead direction from the sample is collimated by a condenser 126 and distributed by a dichroic beam splitter 127 , as a function of wavelength, to further detectors 123 , 124 . Filters 128 , 129 are provided in front of the detectors in order to suppress those components of the detected light which have the wavelengths of pump light beam 114 or of Stokes light beam 115 , or of other light.
[0058] FIGS. 2 and 3 have already been referred to in the introductory section.
[0059] FIG. 4 shows, in the respective partial figures A and B, a sample 1 derived from a biological source. Sample 1 can be, for example, a cell to be tagged and/or a surface of a microscopic section and/or a correspondingly prepared tissue sample.
[0060] In the example depicted, sample 1 comprises an intrinsic chemical structure, labeled 2 , that is capable of coupling with a reaction partner, here labeled 3 . In the example depicted, reaction partner 3 encompasses a coupling site 4 and a resonance site 5 that, upon excitation by means of laser irradiation, can produce a resonance signal as a result of coherent anti-Stokes Raman scattering.
[0061] Figure detail A of FIG. 4 shows a non-coupled state between intrinsic chemical structure 2 of sample 1 and reaction partner 3 . Partial figure B, on the other hand, illustrates a coupled state, the result of which is that resonance site 5 of reaction partner 3 can now be used as part of sample 1 for detection.
[0062] Whereas FIG. 4 and its parts A and B show a single-stage reaction, FIG. 5 illustrates a two-stage reaction. In this, intrinsic chemical structure 2 is firstly coupled to a coupler molecule 6 that comprises a first functional group 7 for coupling to intrinsic chemical structure 2 of sample 1 , and a second functional group 8 for coupling to reaction partner 3 that carries resonance site 5 . Intrinsic chemical structure 2 of sample 1 couples here to first functional group 7 of coupler molecule 6 ; reaction partner 3 couples with its coupling site 4 to second functional group 8 of coupler molecule 6 . Coupling sites 4 and resonance sites 5 that are in part drawn differently in FIGS. 4 and 5 serve only for illustration. According to FIG. 5 as well, resonance site 5 becomes part of sample 1 and can correspondingly be detected. Unlike in FIG. 4 , however, partial figure A here shows a coupled state, and partial figure B an uncoupled state.
[0063] In FIG. 6 a method according to an embodiment of an invention is depicted in the form of a schematic flow chart and is labeled 10 in its entirety. The method begins in a method step 11 with the furnishing of a sample 1 . In a method step 12 a bioorthogonal reaction of an intrinsic chemical structure of the sample with at least one further reaction partner is carried out. In a step 13 the sample, having the resonance site that has been furnished by means of the bioorthogonal reaction in step 12 , is introduced into a suitable investigation system, for example a CARS microscope according to FIG. 1 . In step 14 an investigation of the sample is performed in the investigation system. A correspondingly obtained signal is sensed in a step 15 and used, for example, to derive at least one structural property of a chemical structure containing the at least one resonance site.
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A method for investigating a sample ( 1 ), derived from a biological source, using CARS microscopy is proposed, in which method a resonance signal generated by coherent anti-Stokes Raman scattering by excitation of at least one resonance site ( 5 ) of the sample ( 1 ) by means of laser irradiation is sensed in image-producing fashion. The method according to the present invention encompasses furnishing at least one resonance site ( 5 ) by means of a bioorthogonal reaction of an intrinsic chemical structure ( 2 ) of the sample ( 1 ) with at least one reaction partner ( 3, 6 ).
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a polyurethane composition which is stabilized to light-induced embrittlement and to discoloration or change caused by combustion gas as well as atmospheric conditions, and is improved in dyeability. In addition, the composition retains these high performance characteristics against treatments as such end-product processing, dyeing, commercial dry cleaning, and the like. Accordingly, the present composition is utilizable for a wide variety of polyurethane articles including elastic foams, elastic fibers, synthetic leather, etc.
2. Description of the Prior Art
Japanese Patent Publication No. 6510/72 discloses that a phenolic compound having a specific constitution and molecular weight acts as an antioxidant for polyurethane, depresses the coloration thereof caused by smoggy air, and is scarcely extractable from polyurethane fibers with perchloroethylene, a commercial dry cleaning solvent. Japanese Patent Publication No. 48895/72 also discloses that polyurethane compositions, not only improved in dyeability but which are also markedly stabilized against the yellowing caused by ultraviolet rays or by harmful gas, can be obtained by incorporating a stabilizer polyurethane which contains a restricted tertiary amine structure having a specific constitution and molecular weight. Moreover, Japanese Patent Application Laid-Open Nos. 221355/84 and 223751/84 disclose that polyurethane compositions markedly improved in dyeability and in gas resistance can be obtained by incorporating a stabilizer polyurethane which contains a tertiary amine structure different from the above having a specific constitution and molecular weight with a specific terminal structure. The light stability of these compositions can be improved synergistically by joint use of an antioxidant and a light stabilizer.
In any of these prior art compositions, a polymer having the repeating unit of a low molecular compound is used as a stabilizer. The molecular weight of the polymeric stabilizer is defined but it is an average value, that is, the stabilizer has some molecular weight distribution. Accordingly, these stabilizers contain low-molecular fractions which, during the fiber making process, are liable to bleed out on the fiber surface and form scum. In addition, the low-molecular fractions tend to be lost during the processing or dry cleaning of the fibers. The stabilizers also contain high molecular fractions which have poor stabilizing effects. Even when the stabilizer of the most desirable average molecular weight is chosen, it is inevitable that the stability of the polyurethane fibers is remarkably lowered by subjecting them to processing, for example, dyeing under common conditions of pH 4 and a temperature near to 100° C. or commercial dry cleaning.
Consequently there is still a strong demand for an excellent polyurethane composition and stabilizer therefor that can solve these problems.
SUMMARY OF THE INVENTION
An object of the invention is to provide a stable polyurethane composition.
Another object of the invention is to provide a stabilizer for polyurethane compositions which has excellent characteristics.
Other objects of the invention will be apparent from the following detailed description of the embodiments.
In view of the above, the present inventors have made intensive studies, and as a result, found that novel compounds consisting of relatively large molecules represented by the following general formula (I) are excellent as stabilizers for polyurethane, and that polyurethane compositions containing these compounds have superior properties to those of the prior art compositions. ##STR5##
In this formula, X is a residue represented by the following formula (II) or (III), at least three of Y 1 , Y 2 , Y 3 , and Y 4 are residues represented by the following general formula (IV), and the other one, if present, is a glycidyl derivative residue: ##STR6##
In formula (IV); R 1 and R 2 are each an alkyl or aralkyl group, at least one of R 1 and R 2 is attached through its primary carbon to the nitrogen atom, and the total number of carbon atoms of R 1 and R 2 is at least 4; and Z is a residue represented by the following general formula (V), thereby at least three residues Z represented by the general formula (V) are contained in the compounds represented by the general formula (I). ##STR7##
In formula (V), R 1 and R 4 are the same or different and each represent an alkyl group of 1 to 4 carbon atoms.
The stabilizer of the present invention is capable of improving polyurethane to a great extent in the resistance to gas-caused yellowing and to light-induced embrittlement. When the stabilizer is used jointly with other types of antioxidant and light stabilizer, the resistance to light-induced embrittlement can be enhanced remarkably by synergy. In addition, these stabilizing effects are scarcely lost by treatments such as dyeing and commercial dry cleaning. Moreover the dyeability is enhanced with the stabilizer to a level comparable to those of the known prior art compositions containing tertiary amine groups.
As can be seen particularly from the results of Example 2 of the present invention and Comparative Example 1, the polyurethane composition of the invention has greatly improved light stability and excellent resistance to gas-caused yellowing, as compared with stabilizer-free polyurethane compositions and with those containing well-known prior art stabilizers. The polyurethane composition of the invention exhibits the feature of well-withstanding a harsh treatment such as dry cleaning, while retaining these excellent properties. Further, as can be seen from the results of Example 3 and Comparative Example 2, the present polyurethane composition is synergistically improved in light stability by addition of other types of antioxidants and light stabilizers. The synergistically enhanced stability also is retained without deterioration by such a harsh treatment as dry cleaning. These features of the present polyurethane composition have been scarcely found in the properties of well-known prior art polyurethane compositions. Therefore, polyurethane articles superior in practicality and scarcely degradable can be obtained according to the present invention.
BRIEF DESCRIPTION OF THE DRAWINGS
FIGS. 1, 2, 3, and 4 show infrared absorption spectra of typical stabilizer compounds of the present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
The stabilizer compound of the present invention can be produced with ease, for example, in the following way: The epoxy groups of N,N,N',N'-tetraglycidylxylylenediamine (supplied by Mitsubishi Gas Chemicals Inc. under the tradename of Tetrad-Y) (hereinafter designated as TGX) or 1,3-bis(N,N-diglycidylaminomethyl)cyclohexane (supplied by the same company under the tradename of Tetrad-D) (hereinafter designated as TGH) are reacted with an equivalent amount of a dialkylamine to prepare a compound represented by the general formula ##STR8## wherein X, R 1 , and R 2 have the same meaning as in formulae (II), (III), and (IV). Then the compound of formula (VI) and isophoronediisocyanate are reacted in a molar ratio of 1:4, that is, the hydroxyl groups of the compound of formula (VI) is reacted with the more reactive one of the two isocyanate groups of isophorone diisocyanate, to prepare a compound represented by the following general formula (VII): ##STR9##
Then the isocyanate groups of the compound of formula (VII) are reacted with an equivalent amount of an N,N-dialkylhydrazine to yield a compound of the present invention.
The tetrafunctional epoxy compounds TGX and TGH used in the invention are obtained by the reaction of methaxylylene diamine with epichlorohydrin and the reaction of 1,3bis(aminomethyl)cyclohexane with epichlorohydrin, respectively. Other tetrafunctional epoxy compounds may be produced by the reaction of epichlorohydrin with other aliphatic diamines, for example, ethylenediamine, hexamethylenediamine, isophoronediamine, bis(3-aminopropyl)ether, p-xylylenediamine, and 1,4-bis(aminomethyl)cyclohexane, and may be used similarly to TGX and TGH as raw materials for stabilizer compounds of the present invention. Those epoxy compounds, however, are hard to synthesize without unfavorable side reactions and hence are not suitable for practical use.
Suitable dialkylamines for the preparation of compounds of formula (VI) include secondary amines, for example, diethylamine, di-n-propylamine, N-methyl-N-isobutylamine, dimethylallylamine, di-n-butylamine, di(2-ethylhexyl)amine, dibenzylamine, and N-methyl-N-laurylamine. Dimethylamine and N-methyl-N-ethylamine are undesirable, because the resulting compounds represented by formula (VI), in the reaction thereof with isophoronediisocyanate, show marked tendencies to decrease the difference in reactivity between the two isocyanate groups of isophoronediisocyanate and hence are liable to undergo crosslinking during this reaction. Other dialkylamines undesirable because of their poor reactivities with the epoxy groups of TGX and TGH are compounds, e.g. diisopropylamine, di-sec-butylamine, and dicyclohexylamine, in which the nitrogen atom is linked to the secondary carbon atoms of both the alkyl groups, and those, e.g. N-methyl-N-t-butylamine, in which the nitrogen atom is linked to the tertiary carbon atom of one of the two alkyl groups. Dialkylamines having too many carbon atoms are also undesirable, because the stabilizer derived from such a dialkylamine has low concentrations of tertiary amine and semicarbazide residues and hence an excessive amount of the stabilizer is necessary for blending in order to achieve the intended effect. Thus, dialkylamines of up to about 20 carbon atoms are desirable. Specially preferred dialkylamines are di-n-butylamine, di(2-ethylhexyl)amine, and dibenzylamine. These dialkylamines may be used alone or in combination.
The diisocyanate used to react with the compound of formula (VI) needs to have a large difference in reactivity between the two isocyanate groups. Among such diisocyanates, isophoronediisocyanate is readily available.
Suitable N,N-dialkylhydrazines for the reaction with the compound of formula (VII) include, for example, N,N-diisopropylhydrazine and, N-methyl-N-ethylhydrazine. The alkyl group is preferably a lower alkyl having up to 4 carbon atoms. N,N-dimethylhydrazine is specially preferred. These N,N-dialkylhydrazines may be used alone or in combination.
The compound of the present invention contains generally 6 tertiary amine residues and 4 semicarbazide residues in the molecule, but the effect of the invention can be achieved even when five tertiary amine residues or three semicarbazide residues are contained therein. Accordingly, the compound can be reacted with glycidyl groups or isocyanate groups without adverse effects on the reaction of glycidyl groups with dialkylamines, or on the reaction of isocyanate groups with secondary alcohols or with N,N-dialkylhydrazines, and can therefore be utilized to give variation on the structure of the stabilizer compound of formula (I).
The polyurethane composition of the present invention is stabilized by physically mixing the stabilizer of formula (I) into an elastic polyurethane. Such polyurethanes are generally produced by reacting hydroxyl substituted polymers, such as polyester, polyether, and polycarbonate, of molecular weights from 600 to 3000 with a stoichiometrically excess of organic diisocyanate to prepare intermediate polymers having terminal isocyanate groups, followed by reacting the intermediate polymers with a compound, such as water, hydrazine, organic diamine, glycol, dihydrazide, or aminoalcohol, which have two active hydrogen atoms in the molecule, thereby extending the polymer chains. These segmented polyurethanes having urethane bonds in the molecule are generally well known in the art.
In the present invention, the amount of the stabilizer in such a polyurethane is desired to be in an amount necessary to attain the intended resistance to light-induced embrittlement and to gas-caused yellowing. More than this amount is undesirable since it will bring about side effects. Generally suitable amounts of the stabilizer are such that the total concentration of the tertiary amine and semicarbazide residues becomes 10 to 400 milliequivalents/kg polymer. When the total concentration is less than said lower limit, the effect of the present invention cannot be achieved. Preferably the total concentration is from 30 to 150 milliequivalents/kg polymer.
If desired, it is possible to additionally incorporate an antioxidant such as a hindered phenol or amine type of antioxidant and/or an ultraviolet absorber such as a benzotriazole type of ultraviolet absorber into the composition of the present invention. Surprisingly, the incorporation of these additives synergistically improve the composition of the present invention in the stability to light-induced embrittlement and sometimes in the stability to gas-caused yellowing.
The composition of the present invention may further contain a pigment and other common additives, as desired.
The following examples illustrate preferred embodiments of the present invention.
EXAMPLE 1
Preparation of stabilizer
The preparation process, divided into three steps, is described below. In the first step, a 500-ml flask equipped with a stirrer was fed with each of TGX and TGH and each of various dialkylamines (including a mixture of two dialkylamines) in an amount equivalent to the epoxy groups of the charged TGX or TGH. The air in the flask was replaced by nitrogen gas, the flask was sealed, and the reaction was conducted with stirring at a temperature for a period of time as shown in Table 1.
TABLE 1______________________________________Sym- Temp. TimeNo. bol Feedstock for reaction (°C.) (hr)______________________________________1 A-1 TGX.sup.(a) + Diethylamine 70 242 A-2 TGX + Di-n-butylamine 125 73 A-3 TGX + Diisobutylamine 150 74 A-4 TGX + Di(2-ethylhexyl)amine 150 165 A-5 TGH.sup.(b) + Di(2-ethylhexyl)amine 150 246 A-6 TGX +Dibenzylamine 125 77 A-7 TGH +Dibenzylamine 150 78 A-8 TGX +Dibenzylamine + Ethyl- 125 7 cellosolve.sup.(c)______________________________________ Notes .sup.(a) TGX = N,N,N',N'--tetraglycidylm-xylylene-diamine .sup.(b) TGH = 1,3Bis(N,N--diglycidylaminomethyl)cyclohexane .sup.(c) TGX (4 equivalents of epoxy) to Dibenzylamine (3 equivalents to the whole epoxy of TGX) and Ethylcellosolve (1 equivalent to the whole epoxy of TGX) (Ethylcellosolve = C.sub.2 H.sub.5 OC.sub.2 H.sub.4 OH, i.e., ethylene glycol monoethyl ether).
In the second step, isophoronediisocyanate was added to the reaction mixture obtained in the first step (molar ratio of isophoronediosocyanate to produced secondary alcohol residues=1:1) and heating with stirring was further continued. The reaction was conducted at 70° C. for 3 hours in case of A-1 (symbol in Table 1), at 90° C. for 2.5 hours in case of A-2, and at 95° C. for 2.5 hours in cases of A-3 to A-8. Then a suitable amount of dimethylacetamide was added, and the reaction mixture was cooled to 60° C.
In the third step, a 40% dimethylacetamide solution of N,N-dimethylhydrazine (an amount equivalent to the isocyanate groups remaining in the reaction product of the second step) but, in case of A-8, N,N-dimethylhydrazine (3/4 equivalent) and t-butylamine (1/4 equivalent), was added to the reaction mixture obtained in the second step, and stirring was continued for 20 minutes.
Each of the thus obtained stabilizer solutions corresponding to A-1, A-2, A-4, and A-6 was poured into water with stirring to precipitate the stabilizer, which was then thoroughly washed with water, and dried in vacuo at 50° C. for 20 hours. The thus obtained compounds were measured for infrared absorption spectra and melting points. Results of the infrared spectrometry are shown in FIGS. 1-4. The melt point measurement was conducted by using an apparatus supplied by Mitamura Riken Co., Ltd. (model 7-12). The results were as follows:
______________________________________Stabilizer corresponding to A-1 114° C.Stabilizer corresponding to A-2 94° C.Stabilizer corresponding to A-4 91° C.Stabilizer corresponding to A-6 55° C.______________________________________
EXAMPLE 2
Stabilizers from Example 1 was each added to a polyurethane solution described below so that the total concentration of tertiary amine and semicarbazide residues would become 100 milliequivalents/kg polymer, and 40-denier fibers were made from the mixture in the manner described below. The obtained fibers were found to have satisfactory physical properties for use. Then these fibers, after pretreatment as described below, were evaluated for light resistance and resistance to gas-caused yellowing in the manner described below. Results of the evaluation are shown in Table 2, wherein symbol numbers corresponding to those shown in Table 1, indicate each the composition containing the stabilizer prepared from the corresponding feedstock shown in Table 1.
Preparation of Polyurethane Solution
1000 parts by weight (hereinafter parts by weight are abbreviated as parts) of polytetramethylene glycol of average molecular weight 1600 and 250 parts of 4,4'-diphenylmethanediisocyanate were reacted with stirring at 80° C. under a stream of nitrogen gas to give a prepolymer having isocyanate groups at both ends of the molecule. This prepolymer was dissolved in 1800 parts of dimethylacetamide to form a homogeneous solution, which was then added to a solution of 24.4 parts ethylenediamine and 2.2 parts diethylamine in 1100 parts dimethylacetamide at room temperature. The reaction proceeded quickly, giving a highly viscous solution having a viscosity of 2800 poises at 30° C. Further, 57.45 parts of titanium oxide containing a small amount of a blue-tingeing dye and 164 parts of dimethylacetamide were mixed to thorough dispersion, and added gradually to the above solution with sufficient stirring, yielding a highly viscous solution having a viscosity of 2070 poises at 30° C. This solution is designated as dope A.
Preparation of polyurethane fibers
Various stabilizers (obtained in Example 1) of the present invention were each added to a portion of dope A with stirring to form a uniform solution. The solution was degassed in vacuo to remove bubbles and then discharged through spinneret holes into an atmosphere of about 200° C. to spin fibers. Their drying, false twisting, oiling, and winding-up at a speed 500 n/m gave 40-denier fibers.
Treatment of fibers
Two treatments designated as treatment A and treatment B were conducted. Treatment A is a wash, wherein 40-denier polyurethane fibers in a 50% stretched state under tension are immersed in boiling water for 1 hour, then washed in aqueous solution of a detergent (tradename: New Beads) (concentration 1.3 g/l) at 40° C. for 40 minutes, rinsed with water, and dried at 45° C. for 15 minutes.
Treatment B is a combination of dyeing and dry cleaning, wherein 40-denier polyurethane fibers in a 50% stretched state under tension are immersed in a boiling dyeing bath for 1 hour. The dyeing bath is composed of 1.2 wt% of a dye (tradename: Blankophor CL), 0.5 g/l of ammonium acetate, and acetic acid (a concentration necessary to make the pH 4.0 at room temperature). Then the fibers are rinsed with city water in its stream for 20 minutes, dried at 40° C. for 30 minutes, then immersed in perchloroethylene at 25° C. for 2 hours, and dried at 30° C. for 30 minutes.
Tests for resistance to light-induced embrittlement and to gas-caused yellowing
The test for the resistance to light-induced embrittlement was conducted as follows: 40-denier fibers without stretch are fixed on a white thick paper, and irradiated in a Fade-O-Meter (model FAL-3, supplied by Suga Shikenki Co., Ltd.). Tensile strength of the irradiated sample is measured at a strain rate of 1000%/min by using a tensile tester (model VTM-3, supplied by Toyo-Baldwin Co., Ltd.).
The degree of light-induced embrittlement was represented by the time for halving the tensile strength (hereinafter this time is designated as τ1/2), determined from the relation between the irradiation period and the retention of strength.
The yellowing caused by NOx gas was examined by using the three units respectively with an accelerating test in accordance with JIS L 0855-1976. The yellowing caused by combustion gas was tested in accordance with AATCC-23.
The degrees of yellowing were evaluated by visual observation and ranked into the following classes: class 1--yellow-brown colored, class 2--yellow colored, class 3--pale yellow colored, class 4--slightly colored, and class 5--colorless. When the tinctorial strength was at the middle of two adjoining classes, its rank was expressed by (the number of the higher class-0.5).
COMPARATIVE EXAMPLE 1
A non-segmented polyurethane which is a known stabilizer, containing tertiary amine structure was prepared as follows:
Reaction was carried out by adding 0.05 ml of dibutyltin diacetate to a mixture of 150 g of 4-t-butyl-4-aza-2,6-heptanediol, 175 g of 4,4'-methylenedicyclo hexyldisocyanate, and 210 g of N,N-dimethylacetamide with stirring at room temperature, and continued stirring at 70° C. for 90 minutes.
The thus obtained non-segmented polyurethane (hereinafter designated as TBC) was mixed in a polyurethane solution (the same as used in Example 2) so that the concentration of tertiary amine residues would become 100 milliequivalents/kg polymers. Then polyurethane fibers were prepared from the above mixture, treated, and tested, in the same manner as in Example 2. Results of the test are shown in Table 2. In addition, fibers were prepared from a polyurethane solution containing no stabilizer, and performance characteristics of the fibers were evaluated.
TABLE 2__________________________________________________________________________ Light resistance Degree of yellowing Degree of yellowing τ 1/2 (hr) JIS L 0855-1976 AATCC-23 Stabi- Treat- Treat- Treat- Treat- Treat- Treat- lizer ment A ment B ment A ment B ment A ment B__________________________________________________________________________Example B-1 5 4 4 3 3 32 B-2 8 5 4 4 3.5 3.5 B-3 10 7 3.5 3.5 4 4 B-4 12 9 4 4 4 4 B-5 12 8 4 4 4 4 B-6 20 12 4 3.5 4.5 4.5 B-7 13 10 4 3.5 4.5 4.5 B-8 16 8 4 3.5 4 4Comparative Known 5 1 4 3 3 3Example stabilizer1 TBC No 3 2 1 1 1.5 1.5 stabilizer__________________________________________________________________________
It can be seen from Table 2 that fibers formed from the polyurethane composition of the present invention are excellent in light resistance, particularly superior in light resistance remaining after treatment with perchloroethylene, i.e. after treatment B, said light resistance being a problem of polyurethane fibers containing the prior art stabilizer. It is also revealed that polyurethane fibers according to the present invention are good in resistance to gas-caused yellowing.
EXAMPLE 3
Stabilizers of the present invention were each incorporated, similarly to Example 2, in a polyurethane solution so that said concentration would become 100 milliequivalents/kg polymer. To the resulting mixtures was added a hindered phenolic antioxidant of molecular weight about 2500 produced by reacting isobutylene gas with a p-cresol-dicyclopentadiene condensation product (hereinafter this antioxidant is designated as CCB). Fibers were prepared from the resulting polyurethane solutions. Further, fibers were formed similarly but without addition of CCB. Results of testing light resistance and resistance to gas-caused yellowing on the obtained fibers are shown in Table 3.
COMPARATIVE EXAMPLE 2
The same amount of the same hindered phenolic antioxidant CCB as used in Example 3 was incorporated into the polymer solution prepared in Comparative Example 1. Fibers were formed from this polymer solution, and tested for light resistance and resistance to gas-caused yellowing. Results of the tests are shown in Table 3.
TABLE 3__________________________________________________________________________ Degree of Degree of Light resistance yellowing yellowing τ 1/2 (hr) JIS L 0855-1976 AATCC-23 Anti- Treat- Treat- Treat- Treat- Treat- Treat-Stabilizer oxidant ment A ment B ment A ment B ment A ment B__________________________________________________________________________Example B-4 CCB 47 23 4 4 4 43 B-5 CCB 44 21 4 3.5 4 4 B-6 CCB 43 22 3.5 3.5 4 4.5 B-7 CCB 40 21 4 3.5 4.5 4.5Compara- Known CCB 29 6 3.5 2.5 3 3tive Ex- stabilizerample 2 TBC None CCB 20 5 1 1 2 2Example B-4 None 12 9 4 4 4 42 B-5 None 12 8 4 4 4 4Compara- Known None 5 1 4 3 3 3tive Ex- stabilizerample 1 TBC__________________________________________________________________________
It can be seen from Table 3 that the stabilizer of the present invention when used jointly with an antioxidant (Example 3), exhibits a synergistic effect of improving the light resistance, that is, the effect in this case is greater than the expected effects produced by the separate uses of the stabilizer and the antioxidant. In contrast, the known prior art stabilizer of Comparative Example 2 proves to produce a simple summation of the effects.
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A polyurethane composition comprising an effective amount of a stabilizer compound represented by the general formula ##STR1## wherein, X is a residue represented the formula ##STR2## and at least three of Y 1 , Y 2 , Y 3 , and Y 4 are residues represented by the general formula ##STR3## wherein R 1 and R 2 are each an alkyl or aralkyl group with the proviso that at least one of R 1 and R 2 is attached through its primary carbon to the nitrogen atom and the total number of carbon atoms of R 1 and R 2 is at least 4, the other one of Y 1 , Y 2 , Y 3 , and Y 4 , if present, is a glycidyl derivative residue, and Z is a residue represented by the general formula ##STR4## wherein R 3 and R 4 are the same or different and represent each an alkyl group of 1 to 4 carbon atoms, thereby at least three residues Z represented by the general formula (V) are contained in the compound represented by the general formula (I), and a stabilizer for polyurethane compositions represented by said general formula (I).
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TECHNICAL FIELD
[0001] This invention relates to the field of semiconductor materials, and in particular, to the growth of semiconductor crystals.
BACKGROUND OF THE INVENTION
[0002] An obstacle in realizing next-generation microelectronic and optoelectronic devices and optimal integration of these devices is found in lattice mismatches between different crystals of group III-V semiconductor materials. Generally, the lattice mismatch between a substrate and an epitaxial over-layer induces strains within the over-layer. This may lead to strain relaxation which can result in formation of material defects such as dislocations within the crystalline structure of the over-layer. FIG. 1 illustrates a mismatched over-layer 1 epitaxially grown over a substrate 2 , the boundary between the over-layer 1 and the substrate 2 being indicated with reference numeral 4 . As shown in FIG. 1, the lattice constant associated with the over-layer 1 is different from the lattice constant associated with the substrate 2 , hence the term “mismatched over-layer”. Strain relaxation due to lattice mismatch is accommodated by the formation of mismatch dislocations 3 within the crystal. Defects within a crystal generally degrade the performance of devices made from the crystal, because such defects can scatter movement of carriers (electrons and holes) and can act as carrier traps and/or recombination centers. It is thus useful to provide means for growing a crystal over-layer which has different lattice constant from the substrate on which the over-layer is grown, in such a fashion that strain relaxation does not occur and mismatch dislocations do not form. FIG. 2 is an example of this, in which the structure of over-layer 1 is preserved and no mismatch dislocations are formed.
[0003] In the prior art, two main approaches are used to address the lattice mismatch problem and the strain relaxation it causes:
[0004] 1) In a first approach, defects are confined in thick relaxed buffers so that the top active layer of a device can be of a different lattice constant from that of the substrate and is as defect free as possible.
[0005] 2) In a second approach, thin compliant solid layers are bonded to foreign substrates and re-growth is performed.
[0006] However, these approaches still present performance degradation problems. A buffer layer of defects degrades the quality of the active layer on top of the buffer layer used for a device. In addition, thick buffer layers are not very suitable for device fabrication because high mesa or deep isolation implants are then necessary for device isolation, and can result in high leakage currents and low wafer yields. Further, procedures for implementing the second approach are rather complicated due to problems associated with wafer bonding, fabrication of thin layers (tens of Å in thickness) and re-growth on surfaces contaminated in the wafer-bonding and fabrication processes.
[0007] Hence, there is a need for a method of growing a crystal over a substrate such that mismatch dislocations are prevented from appearing within the crystal, even though the crystal and the substrate have different lattice constants.
BRIEF DESCRIPTION OF THE INVENTION
[0008] In accordance with this invention, compliant layers of group-V species are formed in situ, which distinguishes this invention from the prior art. Indeed, in this invention, formation of compliant layers does not require wafer-bonding and fabrication procedures performed outside of the growth chamber. Furthermore, crystals grown on top of compliant layers will not be strained and therefore, will not suffer strain relaxation which results in dislocation defects.
[0009] The present invention relates to processes and methods which facilitate the epitaxial growth of group III-V crystals of different lattice constants on top of each other. One object of this invention is to suppress strain relaxation associated with lattice-mismatched epitaxy. This is realized with a growth process that initially forms a substrate surface free of oxides. The growth process then deposits, at appropriately low growth temperatures, a layer of condensed group-V species and a mono-layer of constituent group-III atoms in order for the crystal over-layer to retain the condensed layer. Subsequently, the mono-layer is annealed at a higher temperature. Finally, the bulk of the crystal over-layer is grown with the condensed group-V layer accommodating the strain build-up which occurs during the bulk growth.
[0010] In one example of the lattice-mismatch growth process, the substrate may be gallium arsenide, the condensed group-V species may be arsenic and the crystal over-layer to be grown may be indium arsenide (The lattice constant of indium arsenide differs from that of gallium arsenide by 7.2%).
[0011] In one aspect, the present invention relates to a semiconductor device comprising a substrate of a group-III/group-V material, a layer of a group-V material disposed over the substrate, a mono-layer of group-III atoms disposed over the layer of group-V material, and a layer of a group-III/group-V crystal epitaxially grown over the mono-layer.
BRIEF DESCRIPTION OF THE DRAWINGS
[0012] [0012]FIG. 1 is a schematic representation of a mismatched layer where some of the strain has relaxed by the formation of mismatched dislocations within the grown upper layer;
[0013] [0013]FIG. 2 is a schematic representation of how lattice mismatch is accommodated by a condensed layer of group-V species in accordance with this invention;
[0014] [0014]FIG. 3 is a schematic representation of the growth chamber illustrating desorption of surface oxides from the surface of the substrate;
[0015] [0015]FIG. 4 is a schematic representation of the growth chamber illustrating the deposit of a first layer of group-V species over the substrate;
[0016] [0016]FIG. 5 is a schematic representation of the growth chamber illustrating the deposit of a second layer of group-III species over the first layer of group-V species;
[0017] [0017]FIG. 6 is a schematic representation of the growth chamber illustrating the epitaxial growth of a crystal over the second layer;
[0018] [0018]FIG. 7 is a schematic representation of a semiconductor device in accordance with this invention; and
[0019] [0019]FIG. 8 is a schematic representation illustrating an exemplary embodiment of a semiconductor device in accordance with this invention.
DETAILED DESCRIPTION OF THE INVENTION
[0020] In accordance with this invention, the process or method of growing of a group III-V crystal on top of another group III-V crystal (substrate), without introducing lattice-mismatch defects, include the following steps:
[0021] Step 1: Thermal Desorption Cleansing of the Substrate
[0022] In a preferred embodiment, the material forming the substrate upon which the epitaxial over-layer is to be grown may include GaAs, GaP, InAs or InP. As would be apparent to the skilled person, other group III-V compounds or crystals may be used as well.
[0023] In this step, and as illustrated by FIG. 3, the substrate 7 is first heated inside a growth chamber 6 , to a temperature T s , where T s ranges from about 495° C. to about 600° C. Vapor 8 comprising group-V species (e.g., As 2 , As 4 , P 2 ,P 4 or other group-V members) is introduced in the growth chamber 6 when the substrate 7 is heated. The pressure P of the vapor 8 introduced may range from about 0.004 pa to about 0.012 pa, which pressure P is larger than the vapor pressure P s of the substrate 7 at temperature T s . The temperature of the vapor 8 which is introduced in the growth chamber 6 , may range from about 300° C. to about 1000° C. The substrate 7 is then annealed under this over-pressure of group-V species vapor, at temperature T s , and desorption of surface oxides 9 from the substrate 7 takes place, with the surface oxides being removed from the chamber by pump 20 .
[0024] Step 2: In situ Introduction of Condensed Group-V Species
[0025] As sown in FIG. 4, an ultra-thin layer 11 of condensed group-V species (layer 4 of FIG. 1) which, in a preferred embodiment may comprise As 2 , As 4 , P 2 or P 4 , is then introduced in situ at a temperature T c , which temperature is lower than the optimal growth temperature for epitaxy of the crystal which is to be grown. Temperature T c may vary from about 30° C. to about 250° C. In this step, and as illustrated by FIG. 4, a vapor 13 comprising a group-V species is introduced onto the surface of the substrate 7 by opening shutter 19 . When the temperature T s of the substrate 7 is appropriately low (between about 30° C. and about 250° C.), and the pressure P c of the group-V vapor 13 is adequate (about 0.004 pa to about 0.012 pa), condensation of the group-V species on the substrate 7 takes place. The thickness of the layer 11 of group-V species which condenses on the surface of the substrate 7 , can be controlled by varying the temperature T s of the substrate 7 . Indeed, the amount of desorption from the condensed layer of group-V species is dependent on the temperature. In other words, different thicknesses of the layer 11 can be achieved by varying the temperature T s . The temperature T s of the substrate 7 is preferably set such that the thickness of the layer of the group-V species falls into a range of several Å to a few tens of Å. The desired thickness of the layer 11 is achieved as soon as the temperature T s is reached, generally in a matter of seconds.
[0026] Step 3: Deposit of a Mono-layer of Group-III Atoms on the Group-V Layer
[0027] A layer of group-III atoms 12 is then deposited over the group-V layer 11 previously deposited on the substrate 7 , as illustrated by FIG. 5. This layer 12 may be have a thickness ranging from one atom to a few atoms. In the preferred embodiment, the layer 12 is a mono-layer of group-III atoms. The layer of group-III atoms 12 may comprise In, Ga, Al or any combination of Ga, Al and In. The deposit may be made by opening, for an appropriate duration of time (between about 1 second and about 3 seconds) the shutter 14 of the furnace 15 containing a vapor of group-III atoms 17 . This duration of time may vary according to the geometry of the shutter 14 and furnace 15 , and the evaporation rate of the group-III atoms introduced. The vapor of group-III atoms is introduced at a temperature ranging from about 780° C. to about 1250° C. and at a pressure of about 5×10 −5 pa. In atoms are preferably introduced at a temperature of about 780° C., Ga atoms are preferably introduced at a temperature of about 900° C., and Al atoms are preferably introduced at a temperature of about 1200° C.
[0028] After introduction of the vapor of group-III atoms 17 in the growth chamber 6 , the vapor of group-III atoms 17 condenses on the surface of the substrate 7 above the layer of group-V atoms 11 , forming a mono-layer of group-III atoms 12 . At this stage the substrate 7 is kept at a temperature T d ranging from about 30° C. to about 250° C. and the pressure of the group-V vapor 13 which was introduced in step 2 is maintained around 0.008 pa. The mono-layer of group-III atoms 12 , is then annealed by raising the temperature of the substrate T d to a temperature from about 400° C. to about 580° C., under a pressure of group-V vapor 13 of about 0.008 pa. Such mono-layer of group-III atoms 12 has the property of changing the desorption tendency of the group-V species layer 11 lying underneath, and allows retention of the group-V species layer 11 during the annealing phase, which precedes the actual epitaxial growth of the crystal at an optimal growth temperature. The group-III atoms in the mono-layer 12 will seek lattice sites of a lower free energy during annealing, and will therefore form a propitious starting atomic plane for subsequent epitaxial growth. Because the bonding, between group-V molecules in the thin condensed layer 11 initially deposited, is much weaker than that between atoms of the solid crystal to be grown, the group-V molecules will relocate during the subsequent epitaxy to accommodate the lattice mismatch between the solid substrate crystal 7 and the desired solid crystal over-layer.
[0029] Step 4: Epitaxial Growth of Crystal
[0030] Growth of bulk group III-V species layer 18 may then be initiated by opening again the shutter 14 of the group-III furnace 15 as illustrated by FIG. 6. Such group III-V species layer 18 may include InAs, In x Ga 1−x As, In x Al 1−x As or GaP, but other group III-V species may be contemplated as well. In a preferred embodiment, group-V species and group-III species are introduced in the growth chamber with the ratio of the group-V flux to the group-III flux being maintained in the range of about 1.5 to about 3.
[0031] For the purpose of illustration, the method of growing a group III-V crystal on top of another group III-V crystal, without introducing lattice-mismatch defects, is described in the particular example where the substrate is GaAs, the thin-layer of group-V species is As 2 , the mono-layer of group-III atoms is indium, and the crystal epitaxially grown is InAs. This method comprises the following steps:
[0032] Step 1: Thermal Desorption Cleaning of the Substrate
[0033] In one embodiment of this invention, a GaAs substrate 7 is heated to about 600° C. and annealed for about 10 minutes under an As 2 vapor 8 at a pressure of about 0.008 pa, which pressure is larger than the vapor pressure of GaAs at 600° C.
[0034] Step 2: In situ Introduction of Condensed Group-V Species
[0035] In this step, the temperature of the substrate 7 is first allowed to drop or is cooled to about 110° C. while the substrate 7 is subjected to an As 2 vapor pressure 13 of about 0.008 pa, so that a condensed layer 11 of As 2 is formed on the surface of the substrate 7 . The As 2 condensed layer 11 is then thinned down to the desired thickness, which thickness is preferably around several tens of Å or less, by then raising the temperature of the substrate 7 to about 250° C.
[0036] Step 3: Deposit of a Mono-layer of Group-III Atoms on the Group-V Layer
[0037] In this exemplary embodiment, the desired number of group-III atoms per surface area forming the mono-layer is approximately 6.5e14 cm −2 . The shutter 14 of the furnace 15 is opened to introduce indium vapor 17 at 790° C. so that a mono-layer of indium 12 is deposited over the condensed As 2 layer 11 . When the group-III flux incident on the growth surface is about 6.5e14/2.2 cm −2 s −1 , the shutter is preferably opened for 2.2 seconds in order to obtain the desired mono-layer of 6.5e14 cm −2 group-III atoms. The substrate temperature is kept at about 250° C. while still being subjected to a pressure of As 2 vapor 13 of about 0.008 pa. The temperature of the substrate 7 is then raised to about 400° C. while the As 2 pressure 13 inside the growth chamber is maintained around 0.008 pa. The mono-layer of indium 12 is annealed when the substrate temperature ramps from about 250° C. to about 400° C. After this step, the conditions are propitious for epitaxial growth of InAs, without introducing dislocation defects due to lattice mismatch between the GaAs substrate and the InAs crystal.
[0038] Step 4: Epitaxial Growth of Crystal
[0039] Growth of bulk InAs layer 18 may then be initiated by reopening the shutter 14 of the indium furnace 15 . The temperature is maintained at the optimal epitaxial growth temperature for InAs, between about 400° C. and about 450° C., while the ratio of the group-V flux to the group-III flux introduced, is preferably maintained around 2.5.
[0040] In the methods described above, the substrate 7 may be heated in any way known in the art, including through contact heat diffusion or radiation heat transfer. In one embodiment, a tantalum filament is heated up by inducing an electrical current through the filament. The filament is preferably disposed adjacent the back of the substrate, such that the heated filament radiates energy to the substrate. Heat shields may be disposed under both the substrate and the filament in such a way that most of the heat radiated by the filament is efficiently transmitted to the substrate.
[0041] A pump 20 may be used throughout the steps of the methods of the present invention in order to rid the growth chamber of unwanted residual vapors, including surface oxides.
[0042] In another aspect, the present invention relates to a semiconductor device as shown in FIG. 7. The semiconductor 20 comprises a substrate 7 of a group-III/group-V material, a layer 11 of group-V material disposed over the substrate 7 , a mono-layer 12 of group-III atoms disposed over the layer 11 , and a layer 18 of epitaxially grown group-III/group-V crystal disposed over the mono-layer 12 . In an exemplary embodiment of the semiconductor device 20 shown in FIG. 8, the substrate 7 is GaAs, the layer 11 is As 2 , the mono-layer 12 is In, and the crystal 18 is InAs.
[0043] Even though the present invention is described in connection with specific group-III and group-V elements, any combination of these elements may be used.
[0044] Having described the invention in connection with certain embodiments thereof, modifications will certainly suggest themselves to those skilled in the art. As such, the invention is not to be limited to the disclosed embodiments except as required by the appended claims.
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The present invention relates a method for epitaxial growth of a second group III-V crystal having a second lattice constant over a first group III-V crystal having a first lattice constant, wherein strain relaxation associated with lattice-mismatched epitaxy is suppressed and thus dislocation defects do not form. In the first step, the surface of the first group III-V crystal (substrate) is cleansed by desorption of surface oxides. In the second step, a layer of condensed group-V species is condensed on the surface of the first group III-V crystal. In the third step, a mono-layer of constituent group-III atoms is deposited over the layer of condensed group-V species in order for the layer of constituent group-III atoms to retain the condensed group-V layer. Subsequently, the mono-layer of group-III atoms is annealed at a higher temperature. In the fourth step, bulk of the second group III-V crystal is grown with the condensed group-V layer accommodating the strain build-up which occurs during the bulk growth.
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CROSS-REFERENCE TO RELATED APPLICATIONS
This application is a continuation-in-part of application Ser. No. 650,414, filed Jan. 19, 1976 and which is a continuation of application Ser. No. 492,692 filed July 29, 1974 and now abandoned.
BACKGROUND OF THE INVENTION
This invention pertains to printers and more particularly to single element printers which are motor driven.
Of the many uses for printers there are two which predominate in number. They are keyboard controlled typewriters and signal controlled output devices for computers, communications terminals and the like. In fact, many such output devices utilize conventional electric typewriters. Of the conventional electric typewriters the single-element print head variety as exemplified by the IBM Selectric family have become the most popular. While such typewriters are adequate for many tasks, it should be realized they are highly complex machines containing innumerable mechanical drives, linkages and the like. This complexity results in an initially expensive machine. In addition, while a typewriter is satisfactory for use by a typist, it not only has a too low upper limit of speed when driven by a computer or the like, but also is not sufficiently rugged for the extended periods of continued use required in many computer, word processing and communications applications. Furthermore, such machines are noisy. These limitations arise from the mechanical complexity of presently available typewriters.
SUMMARY OF THE INVENTION
It is, accordingly, a general object of the invention to provide an improved printer.
It is another object of the invention to provide an improved printer wherein coded combinations of signals represent the characters to be printed and these coded combinations of signals are processed to select the type characters for printing.
It is a further object of the invention to provide an improved single element print head printer.
Briefly, the invention contemplates a print head opposite a platen. The print head includes a print element bearing type characters which are selected by a positioning means. The print element is supported on a rocker means which carries a cam follower and is pivotably mounted so that the print element can impact the platen. A drive shaft with a cam which cooperates with the cam follower is driven by a drive means for unidirectionally rotating the shaft during each cycle at two different speeds, one speed being related to the actual character being printed and the other speed being related to the time required for the print head and element to be in the desired position for printing.
BRIEF DESCRIPTION OF THE DRAWINGS
Other objects, the features and advantages of the invention will be apparent from the following detailed description when read with the accompanying drawing which shows by way of example, and not limitation, an exemplary embodiment of the invention.
In the drawing:
FIG. 1 shows a block diagram of a printer system in accordance with the invention;
FIG. 2 is a logic diagram of the character source of FIG. 1;
FIG. 3 is a logic diagram of the print control of FIG. 1;
FIG. 4 is a plan view of the printer of FIG. 1, the view omitting unrelated parts and being partially diagrammatic;
FIG. 5 is a diagrammatic side view of the printer of FIG. 4 showing cooperating elements and their logic-controlled energizing means;
FIG. 6 is a view similar to FIG. 5 except that structure is clarified, energizing means are omitted or shown schematically and the print head or rocker assembly is retracted;
FIG. 7 is a front view taken on line 7--7 in FIG. 6, parts broken away or are phantom outline and similar except that the rocker assembly is in the print position;
FIG. 8 is a fragmentary plan view taken on the line 8--8 in FIG. 6; and
FIG. 9 are waveforms used to describe the operation of the system.
DETAILED DESCRIPTION
The printer system in accordance with the invention as shown in FIG. 1 includes a printer PR which is connected to character source CS via rotation control unit RC, tilt control TC, print shaft control PC and index control IC. The printer PR hereinafter more fully described, includes a print head having a print element upon the partially spherical surface on which are disposed, by way of example, four rows of twentytwo or twenty-four type characters. At any given time one of these type characters occupies a print position, i.e., is directly opposite a platen so that when the print element is driven against a record-medium-carrying platen, the desired character is printed on the record medium. Each type character on the print element can be represented by a two-quantity address relative to this print position or another fixed position. In particular, each type of character is given an address having a first part indicating the row containing the character and a second part indicating its position within the row. The print element is connected via a shaft to a bidirectional motor (such as but not necessarily a step motor) which rotates the print element to present different type characters within a row for printing when receiving signals via cable DR from rotation control RC. In addition, coupled to the shaft is a transducer which emits a pulse on line SR for each character increment of rotation of the shaft. A second transducer on the shaft emits a single pulse (fiducial) of line FR when the shaft has a specific angular position, i.e. the fiducial point or home position. The print element is also connected via a linkage to another motor of the same type as mentioned above which rotates when receiving signals on line DT from tilt control TC to tilt the element for making available different rows of type characters for printing. Similarly, this motor is connected to transducers which emit pulses on lines FT and ST representing respectively the fiducial position and each row increment of tilt.
The print element is carried on a print head including a rocker which is driven toward the platen to print the character of the print element at the print position. This is accomplished by mechanisms driven during each revolution of a D.C. motor in response to the signal on line DP from print control PC. The amplitude of the signal on line DP determines how fast the motor rotates. Connected to the shaft of this motor (print shaft) are transducers which generate a single pulse on each of the lines CH, C3, and C6 during different angular positions of the shaft. During each rotation, a pulse on line C3 occurs when actual driving of the print head begins, a pulse on line C6 occurs after the actual driving has ended, and a pulse on line CH occurs at the "end" of each revolution. In addition, operatively coupled to the shaft is a tachometer which generates a signal on line SS whose amplitude is proportional to the instantaneous rotational velocity of the shaft.
The print head is supported on a print carrier which is driven laterally parallel to the platen to position the print head sequentially opposite different portions of the record medium (i.e. horizontal indexing or escaping and hereinafter called indexing) so that a line of characters can be printed. The indexing is performed by mechanisms driven by a bidirectional motor (for example but not necessarily, a step motor) in response to signals on cable DI from index control IC. Fixed to the shaft of this motor is a transducer which emits a pulse on line SI for each index increment the shaft has rotated. There is a transducer adjacent to the path of travel of the carrier to indicate when the carrier is at a left margin position by emitting a single fiducial pulse on line FI.
The character source CS hereinafter described in detail includes a character code generator which generates coded combinations of bits representing characters and also generates a "sprocket" pulse indicating a character code is available. There are two types of characters generated. The first type are the alpha-numerics and symbols which must be printed and the second type control movement of the carrier, i.e., space, backspace, tab and carrier return. The source CS includes means for detecting the second type of characters and transmitting unique signals representing these characters. For example, when the character is a carrier return a signal is fed respectively on line CR to index control IC. For each of the printable characters source CS divides the character code into: a first binary number which is fed bits-in-parallel, on cable RV to rotation control RC, this number representing the rotational or column address of the character on the print shell; a second binary number which is fed, bits-in-parallel, on cable TV to tilt control TC, this number representing the row address of the character on the print shell; a third binary number which is fed, bits-in-parallel, via cable PV to print shaft control PC, this number representing the required speed of rotation of the print shaft character; and a fourth binary number which is fed, bits-in-parallel, via cable IV to index control IC, this number represents how many index increments should be performed for the character to permit proportional spacing.
The rotational control RC in general comprises: an absolute position counter which registers as binary number the instantaneous rotational position of the print shell and is unit incremented or decremented in response to pulses on line SR in accordance with the direction of rotation of the shell and is cleared to a home value upon receipt of the fiducial pulse on line FR; a desired position register which receives information from lines RV and stores the rotational position or address of the desired character and a comparator means which compares the numbers stored in the counter and register to stop the rotation when the numbers are equal, and to transmit directional drive signals on cable DR to printer PR.
Tilt control TC is generally the same as rotational control RC and receives its desired address from cable TV, its fiducial pulse from line FT and its incrementing or decrementing pulses from line ST while transmitting its directional drive signals on cable DT.
The index control IC generally comprises: an absolute position counter which registers as a binary number the instantaneous lateral position of the carrier which is unit changed in response to pulses on line SI in accordance with the direction of movement of the carrier; a next position register which is an accumulator register for storing a binary number which gets changed by an amount indicated by the number on line IV: and a comparator means which compares the numbers stored in the counter and register to transmit directional drive signals on cable DI to printer PR. For non printed characters such as carrier return, the indexing starts under the control of the receipt of signals on line CR. At the end of the carrier return and the like operations index control emits a signal on line EI.
It should be noted that since the rotation, tilt and index controls form no part of the invention, they will not be described in detail.
The print control PC hereinafter more fully described in detail is basically a digital-to-analog converter, and a servo-system driving a DC motor.
Each coded combination of bits received from character source CS is connected to a DC voltage which is fed to a drive motor in the printer PR. During each rotation of the drive shaft in the printer PR between the time from the signal on line C6 to the signal on line C3 the drive motor is driven to rotate at a speed required for desired impact of the print element in accordance with the character to be printed. During the remainder of the cycle the motor is driven to rotate at a speed which is a function of the character just printed and the next character to be printed so that the longest one of the tilt, rotate and index operations for this next character ends just as the shaft is in position without waiting to print this next character.
The operation of the printer system PS as shown in FIG. 1 with the aid of the timing diagram of FIG. 9 will be described for general operation realizing that the rotation control RC, tilt control TC and index control IC are initialized and their counters phased with their associated motors by a signal on line BG from character source CS. The basic timing for the system is controlled by rotation of the print shaft of the printer PR whose transducer sequentially and repetitively generates signals on lines CH, C3 and C6. In general at a time TCHN (N=1, 2, 3, . . . ) a signal on line CH from printer PR to character source CS calls for a new character. Then at a time TC3N (N=1, 2, 3, . . . ) a signal on line C3 from the printer PR causes source CS to emit the tilt, rotate and index numbers, respectively on lines TV, RV and IV to the tilt control TC, the rotation control RC and the index control IV. The controls now initiate tilting rotating and indexing by sending signals via lines DT, DR and DI to printer PR. At the same time these numbers are compared in the character source CS with the same numbers for the character that was just printed to determine at what speed the print control PC will drive the print shaft such that the new character is printed just when print head has reached the new index position and the print element is at the tilt and rotate positions which place this new character in the print position. In effect, as will hereinafter become apparent a signal is generated on line DP whose amplitude is a function of the time it will take for the longest of the three movements (tilt, rotate, index to be performed). This signal then drives the print shaft so that the rocker begins moving when the print head and print element arrive at the desired positions. Just before this instant at time TC6N (N=1, 2, 3, . . . ) printer PR emits a signal on line C6 which causes character source CS to change the number being fed to print control PC. This new number is associated with the size of the character to be printed and in effect controls the impact speed. Print control PC in response to this signal transmits a signal on line DP to the printer PR so that the shaft now decelerates to a velocity such that the rocker is thrown forward with a velocity to accomplish the desired impact force. Then the process repeats itself for the next character. Thus it is seen from FIG. 9, that the shaft switches between to velocity levels, one which is related to the impact required for the character to be printed, i.e., velocities VI1, VI2, VI3, . . . for three successive characters, and the other which is related to the time required to move the print head and element between successive characters, i.e., the velocities VD1, VD2, VD3, . . . .
For control characters like carrier return and others taking a long time to accomplish, as will hereinafter become apparent, the print shaft stops just after the printer PR emits a signal on line CH so that the rocker is not thrown until a character is to be printed. In effect no signal is emitted on line DP so the shaft is not rotated. At the end of the carrier return operations the index control IC emits a signal on line EI which character source CS responds to as if it were a signal on line CH.
The character source CS shown in FIG. 2 centers around character code generator CCG which is connected by multiline cable CC1 to decode register DRG. Character code generator CCG can take on many forms such as a keyboard, a computer, a miniprocessor, a modem, a teletypewriter, a magnet tape, disc, card or drum memory, etc. Its requirement is that it present the coded representation of one character each time it receives a pulse from line SC. Preferably, the character codes are presented bits in parallel onto cable CC1. For example, if the code being used represents tilt, rotate, index and impact value of two, six, six and two bits respectively then these sixteen bits are presented simultaneously on sixteen parallel lines of cable CC1. After each character code is so presented code generator CCG emits a character available pulse on line CA.
One character code is emitted onto the lines of cable CC1, each time a pulse is present on line SC connected to the output of three-input OR-circuit B1. At the start of operations the initial clear device IC emits a pulse of line BG which is connected to an input of OR-circuit B1. During normal operations pulses on line CH connected to another input of the OR-circuit B1 call for the characters. At the end of a carrier return a signal on line EI, connected to the third input of the OR-circuit, from the index control IC calls for the next character by emitting a pulse of line SC. It should be noted that the line SC is connected to the input of a delay device DD, such as a one-shot circuit whose output emits a pulse of line GO a given time after receipt of a pulse at its input.
Decode register DRG can be a sixteen-stage flip-flop register wherein each flip-flop has an information input connected to one of the lines of cable CC1 and a gating input connected to line CA. The output of each flip-flop is connected to a line of cable CC2. The lines of cable CC2 are connected to a decoder ROM DCD which decodes the character codes for unique characters such as a carrier return. If the code for carrier return is present then the decoder ROM DC emits a signal on line CR. The cable CC2 is connected to first register FRG which can be the same as decode register DRG. Note that the line C3 is connected to the gating inputs.
The outputs of the first register FRG are connected to the sixteen lines of cable CC3. All sixteen lines of cable CC3 are connected via cable CC3-16 to second register SRG which is similar to the other two registers, however, with line C6 connected to the gating inputs. The two lines of cable CC3 which carry the two bits of the tilt number became cable TV, the six lines of the cable which carry the six bits of the rotate number become cable RV and the six lines of the cable which carry the six bits of the index number become cable IV.
These fourteen lines of CC3-14 (without the two lines carry the impact number) are fed to the minuend inputs of a fourteen-bit parallel subtractor SUB, while the same fourteen lines of cable CC4-14 connected to the outputs of fourteen of the flip-flops of the register SRG are connected to the subtrahend inputs of subtractor SUB. The output of the subtractor SUB will be a fourteen bit number plus a sign bit connected via fifteen-line cable CC6 to inputs of velocity ROM VRM.
The outputs of the two flip-flops of register SRG which store the impact number are connected to gates G2 which can be two two-input AND-circuits each have one input connected to one of the lines of the cable and another input to the line 6-H. The outputs of gates G2 are connected via two-line cable CC7 to inputs of the velocity ROM.
The velocity ROM VRM can be a read only memory having a plurality of addressed registers. Each register stores a number related to a particular shaft velocity. The memory can be divided into two fields. The first field is addressed by the signals on cable CC7. It will be assumed that there can be up to four impact velocities. Therefore each one of four registers of the memory will store an impact velocity number related to an impact velocity. The coded combinations of bits on the two lines of the cable CC7 can select each of these registers.
The same principle prevails for the intercharacter velocity numbers. In this case there are sufficient registers in a second field of the memory to store velocity numbers for all combinations of two successive characters. These registers are selected by signals on lines CC6. In either case the velocity numbers are emitted on lines of cable CC7 to gates G3 which are again a parallel array of two-input AND-circuits with one input connected to one of the lines of the cable CC7 and a second input connected to line H-3. The outputs of the gates G3 are connected to lines of cable PV.
The remainder of the character source CS is the trailing-edge triggered set-reset flip-flops F1, F2 and F3 whose function is to divide each print shaft cycle into different operating segments.
The operation of the character source CS will now be described. When the initial clear unit IC emits a pulse on line BG it clears the flip-flops F1 and F2, all the registers and calls for the first character by a signal on line SC. The character is fed from character source CS to register DRG. It will be assumed the character is not a carrier return or the like. Shortly thereafter delay DD emits a pulse on line GO which reacts flip-flop F3 opening gates G3. Since gates G1 and G2 are closed a zero address is fed to the velocity ROM. In the zero address register is a number which causes the print shaft to rotate at some velocity. When the shaft reaches a certain position printer PR emits a pulse on line C3. This pulse sets flip-flop F1 and opens register FRG which receives the first character. Register FRG transmits the tilt, rotate and index numbers to cables TV, RV and IV, respectively, and the print head and element start moving to the desired character position. At the same time the character code is fed to the minuend input of the subtractor while the subtrahend input receives a number equal to all zeroes, i.e., the home position of the print head and element. The subtrahend emits a remainder number which is fed via gates G1 to the velocity ROM. The address selected therein emits an intercharacter velocity number which is fed via cable CC7 and gates G3 to cable PV. The shaft is now accelerated to the intercharacter velocity and sometime thereafter a pulse is received on line C6. This pulse restores flip-flop F1 closing gates G1, sets flip-flop F2 opening gates G2 and opens second register SRG which receives the character in first register FRG. The impact velocity number is fed from register FRG via cable CC4-2, gates G2, and cable CC7 to velocity ROM VRM. The contents of the register associated with that velocity number are fed via cable CC7 and gates G3 to cable PV. The shaft now decelerates the desired impact velocity. Sometime after impact, printer PR emits a pulse on line CH. This pulse passes through OR-circuit B1 to line SC calling for the second character which is loaded as previously described. The pulse on line CH is fed to AND-circuit G4. This pulse has a duration such that it will be present long enough to gate a signal on line CR from decoder ROM DCD if the character being loaded into decoder register DRG (the second character) is a carrier return. It is assumed that the second character is not a carrier return, therefore flip-flop F3 is not set and gates G3 remain open so that the print shaft keeps rotating. Sometime therafter a pulse is present on line C3 and the cycle continues as above with the subtraction being performed between the character codes in registers FRG and SRG to determine intercharacter velocity, etc.
Whenever a carrier return is decoded, the pulse on line CH gates the signal on line CR at AND-circuit G4 setting flip-flop F3 which blocks gates G3 and the shaft stops since no velocity number is present on lines PV. The CR signal at an inhibiting input of AND-circuit G5 prevents to signal on line GO from resetting the flip-flop F3. When the carrier return operation is finished a signal is fed via line EI through OR-circuit B1 to call for the next character and the operation proceeds as described above. If this character is not a carrier return there is no signal on line CR so that when delay device DD emits a signal onto line GO it resets flip-flop F3 via AND-circuit G5.
Note although the velocity ROM stored all possible intercharacter velocity numbers, the system can be implemented differently. One could determine by comparisons which of the three operations (tilt, rotate or index) took the longest time and then using this value as an address search in a smaller ROM for the desired velocity value.
The print control PC shown in FIG. 3 is basically a servo system wherein the print velocity number on the lines of cable PV is converted in digital-to-analog converter DA to a signal whose amplitude represents the desired shaft velocity. This signal is fed to one input of difference amplifier OA. A signal on line SS connected to a tachometer on the shaft has an amplitude which represents the actual shaft velocity. This signal is fed to the other input of the amplifier OA. Difference amplifier OA transmits the difference or error signal to the power amplifier PA whose output is connected to line DP.
The printer PR is shown in FIGS. 4 to 8. A print carrier assembly 20 is trunnioned at a pair of rollers 22 straddling a traverse rod 24 fixed in frame 14 and pairs of rollers 26 straddling a traverse rod 28 also fixed in frame 14.
Carrier 20, comprising a ribbon-feed 30, a print head 32 and a D.C. motor 50, is stepped via a cable means 34, by a step motor 36. A transducer 38, on motor 36 relays information to index control IC of FIG. 1.
In particular, when step motor 26 receives the stepping signals on cable DI from index control IC, the motor rotates pulley 34A causing the cable means 34 to move the carrier 20 to the left or right. At the same time, transducer 38 which can comprise a disc 38A with a band of slots, and a light source-light sensitive cell, such as a light emitting diode-photosensitive solid state device straddling the band indicated generally as combination 38B, emits a pulse on line SI each time a slot of disc 38A is operatively opposite combination 38B. In addition, carrier 20 carries a light interposer 39A which interrupts a light path established between a light source and a light sensitive cell indicated generally at 39B to cause the transmission of a pulse on line FI to index control IC when the print carrier 20 is at the left hand margin. (This signal can be used for carrier return complete signal.)
The print head has rotate step motor 42 which rotates in a clockwise or counter-clockwise direction as viewed in FIG. 4 in response to step signals received on cable DR from the rotation control RC of FIG. 1. Connected to the shaft of motor 42 is a slotted disc having one band of twenty-two equispaced slots (one for each character in a row) and a second band with a single slot. Each of the bands is straddled by light source-light sensitive cell combinations indicated generally by box 44. Thus as the motor 42 is stepped a pulse is emitted on line SR as each of the slots of the first band is sensed. In addition, whenever the slot of the second band is sensed a pulse is emitted on line FR to rotation control RC of FIG. 1. The details of how step motor 42 rotates print head 40 will be described hereinafter in detail.
A tilt step motor 46 rotates clockwise or counter-clockwise in response to step signals received on cable DT from tilt control TC of FIG. 1. Connected to the shaft of motor 46 is a slotted disc having one band with four slots one for each row of characters and a second band with a single slot, each of the bands is straddled by a light source-light sensitive cell combination indicated generally by box 48. Thus as the motor 46 is stepped a pulse is emitted on line ST as each slot of the first band is sensed, and whenever the slot of the second band is sensed a pulse is emitted on line FT to tilt control TC of FIG. 1.
Shaft 18 is driven by D.C. motor 50 in response to signals received on cable DP from print control PC, the amplitude of the signal determining the rotational velocity of the shaft. Connected to the shaft of motor 50 is a disc having three slots, each in different bands, straddling each band is a light source, light sensitive cell combination indicated generally by box 52. Thus, as the motor 50 is rotated a pulse is emitted sequentially on lines CH, C3 and C6. The positions of the slots associated with line C3 are chosen to indicate when the actual printing is to start as will hereinafter become apparent.
In addition, a tachometer 53 is operatively connected to shaft 18 to give a voltage on line SS whose amplitude is an indication of the instantaneous velocity of the shaft.
The platen-rotation means 54 and ribbon-feed means 56, although linked operatively through manual, mechanical and logic control, are not a part of the invention, and therefore are referenced for edification only.
The basic operations and logic references shown in FIG. 5 center around velocity-controlled cam 58 which cooperates with follower 66 to impel the rocker assembly 60 of print head 32 clockwise around bearing 62 driving the print element 40 toward platen 16. Cam 58 is fixed on shaft 18 which is spindled on carrier 20. Shaft 18 is rotated by D.C. motor 50 which is mounted on carrier 20. In fact, shaft 18 can be the shaft of motor 50. In this way, the print head driving mechanism is greatly simplified over previously known driving mechanisms. (Two additional cams, described hereinafter, are also mounted on shaft 18.)
As best seen in FIGS. 6, 7, and 8, the print head 32 comprises the rocker assembly 60 and the tilt means 68.
The rocker assembly includes pivotable base member 60, mounted for rotation about bearing 62. The member 60 has a yoke 104 and an arm 102 which carries cam follower 66. Yoke 104 spindles print element 40 at bearings 40B, spindles shaft 74 in a bearing, and arm 96 in a bearing 108.
Passing through the base of rocker 60 is shaft 74 of motor 42 having one end connected to universal joint 76. (See particularly FIG. 7). Above universal joint 76, the upper section 74a of shaft 74 is journaled through a housing 40c, tiltable on bearings 40b, to connection with print shell 40. The other end of shaft 74 is the shaft of motor 42 whose housing is mounted on the rocker. Thus rotation of motor 42 presents the twenty-two different angular positions each associated with a different character in the rows of characters on print shell 40 to platen 16.
The tilt means 68 comprises the motor 46 mounted on carrier 20. The shaft of motor 46 is connected via arm 70 and link 72 to bearing 40a in housing 40c. By this means, the rotation of motor 46 selects which of the rows of characters on print element 40 is to be presented to platen 16. It should be noted that since link 72 connected between bearing 40a and pin 70a passes through the pivot point of rocker 60 (i.e. bearing 62) as shown in FIGS. 5 and 6 the differential linkage length is minimized during the pivoting of the rocker assembly 60.
In FIGS. 7 and 8 there is shown on shaft 18 a ribbon feed cam 80 for controlling the ribbon 82. Since the ribbon feed portion of the printer forms no part of the present invention and will not be discussed further.
In addition, shaft 18 has a detent-control cam 84. An arm 86, spindled at a bearing 88, carries a cam follower 90. The outer end of arm 86 spindles a roller 86a engaged by a second arm 92 spindled at a bearing 94. Arm 92, in turn, is engaged by a detent arm 96 that is biased counter-clockwise by a first spring 98 and by a second spring. The detent arm 96 engages and disengages tilt and rotate detents during the print operation.
In operation, rotate motor 42 rotates shaft 74 to select the "column" of the desired character on print element 40 while at the same time tilt motor 46 operative via link 72 tilts print element 40 to the row of the desired character. All this time the shaft 18 is rotating and during each revolution three motions are performed as a result of the rotation of cam 58 to drive rocker member 60, a rotation of cam 80 to move ribbon 82 and a rotation of cam 84 to control the detenting of the print element 40.
During the print part of each shaft cycle rocker assembly 60 responds to follower 66 mounted thereon. This response moves print element 40 towards platen 16 in two separate velocity patterns. Follower 66 is first accelerated by the rise in cam 58 from the dwell 58a to, substantially, the peak 58b, from which point velocity is imparted to the mass of print head 32. In this manner, print shell 40 prints characters at variable impact dependent upon acceleration changes in motor 50. Thereafter the velocity of shaft 18 is determined by the time it will take for the head and print element thereon to be in position for printing the next character.
Finally cam 80 causes the indexing of ribbon 82.
While specific circuits, components and devices have been shown and described it should be realized that they are not unique. For example, the decoders can be decoding matrices, read only memories, programmable read only memories, random access memories, etc. In addition, some of the drive motors were described as step motors. However, these can be any type of servomotor and particularly bidirectionally controlled D.C. motors. The transducers were shown as opto-electrical devices. They could be any shaft position indicating devices using conductive, magnetic, capacitive or other techniques. The tachometer could take on many forms such as a simple generator whose input shaft is connected to the drive shaft 18.
While only one embodiment of the invention has been shown and described in detail there will now be obvious to those skilled in the art many modifications and variations satisfying many or all of the objects of the invention but which do not depart from the spirit thereof.
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A printer has a horizontally movable carrier which supports a print head including a print element on which are disposed type characters in a two dimensional array with the element controllably movable by motors in two degrees of freedom to selectively position each type character opposite a record-medium-carrying platen for printing. The print head is on a rocker having a cam follower which cooperates with a cam on a shaft driven by a variable speed motor which is also on the carrier. During printing the motor speed is controlled so that the print element is driven against the platen with a force related to the particular character being printed. The motor speed is further controlled so that there is not only a minimum wait between the printing of successive characters but there are also minimum accelerations and decelerations of the motor.
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CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a continuation of and claims priority under 35 U.S.C. §120 to U.S. patent application Ser. No. 11/749,599 entitled “IMAGE SCALING ARRANGEMENT” filed May 16, 2007, which is a continuation of and claimed priority under 35 U.S.C. §120 to U.S. patent application Ser. No. 10/973,657 entitled “IMAGE SCALING ARRANGEMENT” filed Oct. 25, 2004, now U.S. Pat. No. 7,433,546 issued Oct. 7, 2008.
[0002] Ser. No. 10/973,657 is related to: (i) U.S. application Ser. No. 10/973,925 entitled “MULTIPLE MEDIA TYPE SYNCHRONIZATION BETWEEN HOST COMPUTER AND MEDIA DEVICE,” filed Oct. 25, 2004, which is hereby incorporated herein by reference; (ii) U.S. Provisional Application No. 60/622,304, Oct. 25, 2004, and entitled “WIRELESS SYNCHRONIZATION BETWEEN MEDIA PLAYER AND HOST DEVICE,” which is hereby incorporated herein by reference; (iii) U.S. application Ser. No. 10/277,418, filed Oct. 21, 2002, and entitled “INTELLIGENT INTERACTION BETWEEN MEDIA PLAYER AND HOST COMPUTER,” which is hereby incorporated herein by reference; and (iv) U.S. application Ser. No. 10/118,069, filed Apr. 5, 2002, and entitled “INTELLIGENT SYNCHRONIZATION OF MEDIA PLAYER WITH HOST COMPUTER,” which are hereby incorporated herein by reference.
BACKGROUND OF THE INVENTION
[0003] 1. Field of the Invention
[0004] The present invention relates to portable media devices and more particularly to data transfer with portable media devices.
[0005] 2. Description of the Related Art
[0006] The hand-held consumer electronics market is exploding, and an increasing number of these products including for example PDAs, music players, cellular phones, cameras, and video games have increased their functionality to distance themselves from their competitors. By way of example, cellular phones have added PDA and camera functionality, PDAs have added cellular phone and music player functionality, music players have added PDA and video game functionality, etc. In the future, it is foreseeable that the functionality of all these devices will continue to merge into a single device. As these products evolve, it is believed that many design challenges will be encountered.
[0007] Many hand-held computing devices work hand in hand with a personal computer. The personal computer typically serves as a base to the portable hand-held computer device. For example, because they are hand-held, they are typically a portable extension of the personal computer. Like personal computers, these highly portable devices typically include a processor that operates to execute computer code and produce and use data in conjunction with an operating system. Unlike personal computers, however, these devices typically use less complex operating systems as well as smaller and less expensive processors that are slower than the processors used in personal computers. While this may be appropriate when the devices operate normally, difficulties arise when these hand-held computing devices are called upon to perform process intensive tasks. The difficulties include slow responsiveness and high power consumption. As a result, the user may be left with a negative user experience, i.e., users may not like a product that is slow and whose battery life is short.
[0008] Personal computers typically include software that helps manage the handheld computing devices. The personal computer may include for example a photo management program that helps transfer photos from the camera to the personal computer. The photo management program may also allow a user to sort, store and catalog their images as well as to provide touch-up capabilities such as red eye reduction, black and white conversion, image cropping and rotation. In some cases, the cameras modify the original image by embedding or storing thumbnail images inside the original image. The photo management program uses the embedded thumbnail images when importing the original image. For example, as each photo is being imported, the photo management program may show the thumbnail image thereby relaying to the user that the image is being imported.
[0009] In addition to photo management programs, the personal computer may also include music management programs that help transfer music from the personal computer to a music player such as an MP3 music player. Like the photo management program their music, the music management program may also allow a user to sort, modify, store and catalog their music. More particularly, the music program may give the user the ability to organize their music into playlists, edit file information, record music, download files to a music player, purchase music over the Internet (World Wide Web), run a visualizer to display the music in a visual form, and encode or transcode music into different audio formats such as MP3, AIFF, WAV, AAC, and ALE. Typically, music players only understand a single music format. Therefore, the music management program typically can to transcode the music stored in the personal computer from one music format to the desired music format of a music player.
[0010] In some cases, both the photo and music programs are linked so that the images and music stored therein can be played together. For example, the photo management program may allow a user to produce slide shows that show images to music. By way of example, the photo management program may correspond to iPhoto® and the music management program may correspond to iTunes®, both of which are manufactured by and available from Apple Computer Inc. of Cupertino, Calif.
[0011] Synchronization operations have been conventionally performed between portable devices, such as Personal Digital Assistants (PDAs) and host computers, to synchronize electronic files or other resources. For example, these files or other resources can pertain to text files, data files, calendar appointments, emails, to-do lists, electronic rolodexes, etc.
[0012] In the case of media players, such as MP3 players, files are typically moved between a host computer and a media player through use of a drag and drop operation, like is conventionally done with respect to copying of a data file from a Windows desktop to a floppy disk. Hence, the user of the media player can manually initiates synchronization for individual media items. As a consequence, synchronization tends to be tedious and time consuming for users. More recently, media players have been able to be synchronized with a host computer when a bus connection over a cable is made. Here, the synchronization can be automatically initiated when the cable is connected between the host computer and the media player. The iPod® offered by Apple Computer, Inc. of Cupertino, Calif. has the capability to provide such synchronization over a cable.
[0013] Thus, there is a continuing need for improved features for connecting and transferring data between media devices and their hosts.
SUMMARY OF THE INVENTION
[0014] The invention relates, in one embodiment, to a computing device. The computing device includes at least a data storage device for storing at least a plurality of media items, and a media management module configured to at least (i) receive a media request for at least one media item from a portable media device; (ii) obtain information regarding characteristics for the portable media device; (iii) obtain, based on the characteristics, a set of media items for each of the at least one media item being requested by the media request; and (iv) cause the set of media items to be sent to the portable media device.
[0015] The invention relates, in another embodiment, to a computing device. The computing device includes at least a data storage device for storing at least a plurality of media items, and a media management module configured to at least (i) pre-process a plurality of media items to produce a plurality of additional media items from each of the media items; (ii) store the additional media items in said data storage device; and (iii) deliver at least the additional media items to a portable media device.
[0016] The invention relates, in another embodiment, to a portable media device. The portable media device includes at least a data storage device configured to store media data pertaining to media items and to store device characteristics pertaining to said portable media device, an output device, and a processing device configured to (i) send at least a portion of the device characteristics to a host device, (ii) receive media data pertaining to one or more media items to be stored on said data storage device, the one or more media items having same or like media data, the received media data being obtained at the host device based on the device characteristics pertaining to said portable media device, (iii) storing the received media data to said data storage device, (iv) subsequently determining whether a particular media item of the one or more media items is to be output by said portable media device, (v) selecting an appropriate one of the determined media items to be output, and (vi) output the data for the selected determined media item.
[0017] The invention relates, in another embodiment, to a computer readable medium that stores computer program code for managing media items. The computer readable medium includes computer program code for receiving a media request for at least one media item from a portable media device, the media request including or referencing information regarding characteristics of the portable media device, computer program code for generating, based on the characteristics, a set of media items for each of the at least one media item being requested by the media request, the set of the media items generated from the at least one media item including a plurality of media items that have the same or like media data, and computer program code for sending the set of media items to the portable media device.
BRIEF DESCRIPTION OF THE DRAWINGS
[0018] The invention will be readily understood by the following detailed description in conjunction with the accompanying drawings, wherein like reference numerals designate like structural elements, and in which:
[0019] FIG. 1 is a method of transferring image data between a host device and a portable media device, in accordance with one embodiment of the present invention.
[0020] FIG. 2 is an operational method for a portable media device, in accordance with one embodiment of the present invention.
[0021] FIG. 3 is a method of transferring image data between a host device and a portable media device, in accordance with one embodiment of the present invention.
[0022] FIG. 4 is an exemplary diagram of a photo database file, in accordance with one embodiment of the present invention.
[0023] FIGS. 5A-5F are diagrams of image set files, in accordance with several embodiments of the present invention.
[0024] FIG. 6 is media method, in accordance with one embodiment of the present invention.
[0025] FIG. 7 is a block diagram of a media management system, in accordance with one embodiment of the present invention.
[0026] FIG. 8 is a block diagram of a media player, in accordance with one embodiment of the present invention.
[0027] FIG. 9 is perspective view of a handheld computing device, in accordance with one embodiment of the present invention.
[0028] FIG. 10 is a media device operational method, in accordance with one embodiment of the present invention.
[0029] FIGS. 11A-11E are diagrams of several exemplary screen shots of a media player with photo viewing capabilities, in accordance with several embodiments of the present invention.
[0030] FIG. 11F is a diagram of a pictorial of a TV screen image provided by a television coupled to the media player, in accordance with one embodiment of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
[0031] The present invention relates to portable media devices with image functionality and also to image transfer between portable media devices and their hosts. Media devices with image functionality typically require several different image formats to support the various display modes of the media device. For example, media devices typically require a full screen image that fills the entire display screen of the media device as well as various thumbnail images, which may help a user browse through a group of images.
[0032] One method for creating these various images is to download the original image to the portable media device and then to transcode the original image into the required formats on the portable media device when they need to be displayed. This is sometimes referred to as processing data on-the-fly. While this may work, it is generally believed that this methodology has several drawbacks that make it less appealing to the user. For example, because formatting images is a process intensive task (especially on portable media devices that lack the horsepower of their larger hosts), portable media devices tend to operate slowly and consume more power. Hence, formatting images on portable media devices tend to result in an unsatisfactory user experience. For one, the user has to wait while the image is being formatted. For another, the battery of the portable media device tends to run out more regularly.
[0033] In order to overcome these drawbacks, the present invention provides a method where images are preformatted on the host before or during the download thereto. When an image is identified for download various preformatted images derived from the original image (and possibly the original images) are sent to the portable media device. The processing is performed on the host, which can handle these tasks more easily than the portable media player. The tasks may, for example, include scaling, cropping, rotation, color correction and the like. Once received by the portable media device, the preformatted images and possibly the original image are stored for later use. By storing these images, the media device is relieved from having to perform any of the labor intensive tasks associated with image formatting. That is, the preformatted images relieve the media device of much of the work required to display them. As a result, the device operates faster and without repeated needs for recharging. In one embodiment, at least some of the preformatted images are thumbnail images.
[0034] During media device use, a user may request that an image be displayed. Instead of processing the original image as in the method described above, the device simply obtains the appropriate preformatted image from storage and presents it to the user on a display. The preformatted images may include a full screen image and several different thumbnail sized images. The full screen image typically depends on the size of the display contained in the portable media device, i.e., the full screen image generally fills the entire screen. The different sized thumbnail images, which come in various sizes, may be used in a variety of ways including separately or together. For example, a plurality of smaller thumbnails may be grouped together so that a user can quickly browse through a large number of images. The preformatted images may also follow formats associated with standards or other devices to which the portable media device can be linked. For example, at least one the preformatted images may be based on television formats so that the portable media device can present images on televisions (TVs). The TV formats may, for example, include NTSC, PAL, HDTV, and the like. The formats may also be based on formats associated with printers, cameras or similar image using devices.
[0035] In some cases, the media device when connected to a host expresses or informs the host as to which image formats are desired when an image is downloaded to the media device. The media device may, for example, send various image profiles corresponding to the different formats to the host device. The image profile generally contains the attributes or keys for each image format. By way of example, the image profiles may describe size, orientation, pixel format, color depth, etc. for each image format. This particular methodology helps with compatibility issues that typically come up when different media devices having different versions of software and hardware are used, i.e., the version of the software/hardware is made irrelevant since the media device expresses what information it wants from the host device.
[0036] Embodiments of the invention are discussed below with reference to FIGS. 1-11F . However, those skilled in the art will readily appreciate that the detailed description given herein with respect to these figures is for explanatory purposes as the invention extends beyond these limited embodiments.
[0037] FIG. 1 is a method 100 of transferring image data between a host device and a portable media device, in accordance with one embodiment of the present invention. The method 100 may, for example, be performed by media management software. The method includes blocks 102 , 104 and 106 . In block 102 , an image download request is received at the host device. The image download request designates at least one image stored on the host device for downloading to the portable media device. In some cases, only a single image is requested and in other cases a plurality of images are requested. The request can be made at the host device or the media device through a user interface. For example, the user may select a group of images and then select a download button. Alternatively, the request can be made by the media device without user input.
[0038] In block 104 , an image collection for each requested image is produced at the host device. Each image collection contains the new versions or different formats of the original image. In some cases, the image collection may also contain the original image. For example, the new versions may include a full screen image, which corresponds to the screen size on the media player, various thumbnail images, each of which are typically smaller versions of the original image, as well as various other images including for example TV images. It should be noted that the file sizes of the new versions are typically much smaller than the file size of the original image. They therefore take up less space in storage than would the corresponding original image.
[0039] Each new version has a different image profile based on the display needs of the portable media device. The image profiles for particular media devices may be stored in the host device or the image profiles may be given to the host device by the media device. In the first case, the media device may provide the host device with an Identifier (ID), which can be used by the host to determine the image profiles for the requesting media device. For example, after obtaining the ID the host may refer to a previously stored table or list that includes all the capabilities of the identified media device. In the later case, the media device may automatically upload this information as part of synchronization or handshaking procedure with the host device.
[0040] The image profile generally includes a list of keys or attributes which define the qualities or characteristics of each image. The keys or attributes may include for example FormatID, RenderWidth, RenderHeight, DisplayWidth, DisplayHeight, PixelFormat, Sizing, BackColor, Rotation, ScanFormat, ColorAdjustment, GammaAdjustment, and the like.
[0041] FormatID refers to an identification number that defines the image profile. Changing any of the attributes within the image profile will change the identification number. The media management program uses this ID to identify thumbnail locations in both the host and media devices.
[0042] RenderWidth is the width of the image in pixels at render time. RenderHeight is the height of the image in pixels at render time. RenderWidth and RenderHeight generally refers to actual physical size.
[0043] DisplayWidth is the width of the image in pixels at display time. DisplayHeight is the height of the image in pixels at display time. It should be noted that DisplayHeight and DisplayWidth can differ from RenderHeight and RenderWidth in those cases like NTSC where the pixels are not square. DisplayWidth and DisplayHeight generally refer to the true size.
[0044] PixelFormat describes information encoded in each pixel (e.g., color components (RGB), transparency, etc.). Several formats can be used including, for example, the QuickDraw/QuickTime pixel format.
[0045] Sizing describes what happens if the original image is smaller than the desired thumbnail. By way of example, if 0, scale the image to the desired height/width. If 1, scale the image to the desired height/width only if the image is larger than RenderWidth or RenderHeight, i.e., don't scale small images. If 2, center-crop the image to the desired height/width rather than scaling it.
[0046] BackColor describes what color the background should be in cases where the images don't fill the entire viewing area. The background color may be in big-endian ARGB format as a hexadecimal string.
[0047] Rotation described if and how an image should be rotated. The image rotation is typically in degrees. For example, the rotation values may be 0, 90, 180 and 270.
[0048] ScanFormat designates what scan format the image is stored in. ImageFormat may include progressive format or interlace format.
[0049] ColorAdjustment describes whether or not a color adjustment is needed, and if needed what the color adjustment should be. By way of example, if 0, no color adjustment is applied. If 1, NTSC color adjustment is applied. If 2, PAL color adjustment is applied.
[0050] GammaAdjustment describes whether a gamma correction needs to be applied to the image (e.g., brightness). If not supplied, no correction is done.
[0051] In block 106 , the image collection for each requested image is sent to the portable media device as part of the downloading process. Once received by the portable media device, the image collection is stored in the portable media device for later use. The image collection may be stored in the memory of the portable media device. In order to efficiently store the images in memory, each of the different image sets may be stored in their own file. That is, images having the same image profile are grouped in the same file. For example, the original images may be stored in a first file, the full screen images may be stored in a second file, a first set of thumbnail images may be stored in a third file, a second set of thumbnail images may be stored in a fourth file, the TV images may be stored in a fifth file and so on.
[0052] It should be noted that in some cases, the original image may not be sent to or stored on the hand held media device. This may be done to save valuable storage space on the hand held media devices that typically have limited storage capacity. As should be appreciated, the file size of the original image is typically much larger than the thumbnail images and therefore they can take up more space in memory. The decision of whether to include the original image with the rest of the images may be made by the user. For example, the user may be presented with a choice as whether they desire or do not desire to download or store the original image. This decision may be based on how the user uses the media device. For some, the media device may be used to transfer images from one host to another. In cases such as these, the user typically wants to include the original image. The decision may be set for all downloads or it may be made at each down load request. Similarly, the same decision can be made for all the different formats if so desired (as some of these formats may not be needed).
[0053] Once downloaded and during operation of the media device, a display request may be made on the media device. Thereafter, one or more images are retrieved from memory based on the display request. The display request indicates the images to be shown on the media player and/or images that are to be sent to another device connected to the media device. Once retrieved, the images can be displayed. The manner in which the images are displayed are typically determined by the mode of the media device. The modes can include a browse mode, a slide show mode, a full screen mode, etc. In browse mode, a plurality of tiny thumbnail images are displayed in rows and columns. In a slide show mode, a medium thumbnail image may be displayed in the center and smaller thumbnail images may be displayed on either side of the medium thumbnail image. The small image to the left of the medium image may represent a previously shown image, the medium image may represent the current image being shown, and the small image to the left of the medium image may represent the next image in the slide show sequence. If a TV is connected to the media device, the media device may output the TV version of the current image being shown to the TV. In a full screen mode, the full screen image is displayed.
[0054] FIG. 2 is an operational method for a portable media device 200 , in accordance with one embodiment of the present invention. The method includes blocks 202 , 204 , 206 and 208 . In block 202 , image data is stored. The image data includes at least a plurality of image collections. The image collections contain a plurality of differently formatted images based on an original image and may also include the original image. The image collections are not formed on the portable media device. They are separately generated on a device other than the portable media device. The image collections may for example be generated on a host device that downloads them to the portable media device for storage. By way of example, the image collections may be provided by the method described in FIG. 1 . Alternatively or additionally, the image collections may be downloaded from another portable media device that has already downloaded them from a host.
[0055] In block 204 , a display command is received. The display command designates one or more images of the image data to be displayed. The display command may be generated via a user making a selection on the user interface of the media player.
[0056] In block 206 , at least the designated images are retrieved. In some cases, only the designated images are retrieved. In other case, more than the designated images are retrieved. For example, although the display command may only designate a single image, other images associated or linked to that image may be additionally retrieved.
[0057] In block 208 , the one or more retrieved images are outputted. The retrieved images may be outputted to a display. The display may be located on the portable media device or it may be located external to the portable media device. In either case, upon receiving the retrieved images, the retrieved images are displayed. IN some cases, all of the images are displayed, and in other case only a portion of the images are displayed. The later case may be implemented when the size and number of images is greater than the screen size.
[0058] FIG. 3 is a method 300 of transferring image data between a host device and a portable media device, in accordance with one embodiment of the present invention. The method may for example be performed by a media management program operating on the host device. The method begins at block 302 where a down load request is received. The download request designates one or more images to be downloaded from the host device to the portable media device. The download request is typically implemented via a user selection, i.e., a user selects one or more images and initiates a downloading procedure.
[0059] Following block 302 , the method proceeds to block 304 where a database entry is created for each image to be downloaded. The database entry provides information about the images to be downloaded. The information may for example be metadata. Following block 304 , the method proceeds to block 306 where the database entry is written or copied on the media device. The database entry is typically copied to an image database on the media device. If an image database does not exist, one will typically be created. If one does exist, the database entry will be copied thereto.
[0060] Also following block 304 , the method proceeds to block 308 where an image collection is created on the host. This may include transcoding new versions of the selected image based on a plurality of image profiles, and grouping the new versions of the original image and in some cases the original image into an image collection. The image profiles define the features of the new images. By way of example, the image profiles may include keys for making thumbnails and other images such as those which can be used on TV, printers, and other media devices (e.g., camera). The image profiles may be supplied to the host device by the media device, and thereafter stored locally on the host device. This may be part of the synchronization procedure that occurs between the host device and media device when they are connected together.
[0061] Following block 308 , the method proceeds to block 310 where each image in the image collection is written or copied to the media device. That is, each new version of the original image and in some cases the original image are copied to the media device. In one embodiment, each particular type of image is stored in a separate file on the media device. For example, all of the originals are stored in an original image file, all of a first thumbnails are stored in a first thumbnail image file, and so on.
[0062] Following block 310 , the method proceeds to block 312 where the database entry is updated. That is, the database entry is filled with the appropriate image data. The step of updating typically includes grouping together all the images of a particular image collection (original, thumbnails, TV), and providing pointers to the location where the actual image is stored (e.g., image files).
[0063] It should be noted that in most cases the host device stores a copy of the database entry and image collections in parallel with the media device.
[0064] It should be noted that the all or some of the steps mentioned above can occur separately as distinct events or they can occur simultaneously. In the later case, at least some of the steps can be interleaved. In interleaving, while some images are being copied, other images are being created. Interleaving is generally preferred in order to reduce the amount of time needed for downloading.
[0065] The image data stored in the media device will now be described. As mentioned above the image data is spread among multiple files. The main image database file holds image metadata, photo album lists, and “pointers” to the original image as well as all available thumbnails. The images themselves are stored either as individual files (originals) or in image set files, which contain one or more thumbnails of the same type. This is typically done to save storage space. It should be noted, however, that this is not a limitation and that the images may be stored as an image collection rather than in separate files.
[0066] In one embodiment, the photo database file contains a header followed by several “sections.” The number of sections can be widely varied although it is expected that the photo database will contain three sections: image list section, album list section and the image record ID table. The image list section contains a list of all images stored on the media device. Each image entry contains all of the metadata for an image as well as a list of locations for all available images associated therewith including the original, thumbnails and TV. Each image has a unique persistent record ID which is used in both the album and record ID table sections. The album list section contains a list of the albums, each of which is simply an ordered list of image record IDs. The image record ID table is a table containing record IDs and file offsets for all images, sorted in ascending record ID order. This table allows the media device to quickly load only those image records for a given album, rather than requiring loading the whole image record list.
[0067] The images themselves are stored in image set files. Each image set file contains a file header, followed by one or more images, each with a header. This allows scavenging of the data should the need arise. The image records in the photo database are by file specification (path) and file offset, so it is not necessary to parse an image set file to get to a particular image. The number of images per file and/or the maximum image files size may be widely varied. By way of example, the maximum size may be 500 Megabytes.
[0068] The following is an exemplary layout for the photo database stored on the media device:
[0000]
File header
Image List Section Header
Image List header
Image 1 metadata
Image 1 Original Image Location
Image 1 Thumbnail 1 Image location
<additional image locations>
Image 2 Metadata
Image 2 Original Image Location
Image 2 Thumbnail 1 Image location
<additional image locations>
<additional images>
Album List Section Header
Album 1 Metadata
Album 1 Image Record ID 1
Album 1 Image Record ID 2
<additional album images>
Album 1 Metadata
Album 1 Image Record ID 1
Album 1 Image Record ID 2
<additional album images>
<additional albums>
Record ID List Section Header
Record ID List Header
Record ID 1 Description
Record ID 2 Description
<additional record Ids>
[0069] The following is an exemplary layout for an image set file stored on the media device:
[0000]
File Header
Image 1 Header
Image 1 Data
Image 2 Header
Image 2 Data
<additional images>
[0070] FIG. 4 is an exemplary diagram of a photo database file 350 , in accordance with one embodiment of the present invention. The photo database 350 includes a file header 352 , an image list section header 354 , an album list section header 356 and a record ID list section header 358 . Inside the images list section header 354 are image entries 360 , and pointers 362 , which provide image locations for the various images in the image entry including for example the original image O and a plurality of thumbnails T thereof. Inside the album list section header 356 are album entries 364 and record IDs 366 for each of the images in the album. Inside the record ID list section header 358 are Record ID list header 368 and record ID descriptions 370 .
[0071] FIGS. 5A-5E are diagrams of exemplary image set files 372 , in accordance with one embodiment of the present invention. FIG. 5A is a diagram of an original image set file 372 A, FIG. 5B is a diagram of a tiny thumbnail set file 372 B, FIG. 5C is a diagram of a small thumbnail set file 372 C, FIG. 5D is a diagram of a medium thumbnail set file 372 D, FIG. 5E is a diagram of a full screen image set file 372 E, and FIG. 5F is a diagram of a TV screen image set file 372 F. In each of these figures, the image set files 372 include a file header 374 , image headers 376 and the actual image data 378 .
[0072] FIG. 6 is media method 400 , in accordance with one embodiment of the present invention. The method may be performed on a media system including a host device such as a personal computer and a media device. The method begins at block 402 where one or more images are uploaded into a personal computer. The images may be uploaded from a camera, memory device, Internet or the like. After block 402 , the method proceeds to block 404 where the images are stored in the personal computer. Blocks 402 and 404 may be accomplished with a media management program. In Block 406 , a media player is connected to the personal computer. This may be accomplished through a wired or wireless connection. The connection may include a handshaking and/or synching procedure.
[0073] In some cases, the media management program is automatically opened when the two devices are connected. The particular media management program opened may depend on the type of media device. If the media device is a music player, the media management program may be a music program. If the media device is a photo player, the media management program may be an image program. If the media device is a combination music/photo player, the media management program may be music program or a photo program or a combination of the two. If the different programs are operated independently, the music program and the photo program may be linked so that information can be shared there between. For example, the music program may be able to access data from the photo program and vice versa.
[0074] In block 408 , images and/or image identifiers (e.g., text) are presented on the personal computer. This too may be accomplished with the media management program. In fact, the images and image identifiers may be included in a photo window associated with a graphical user interface. In block 410 , a download command is generated. The download command designates one or more images to be downloaded from the personal computer to the portable media device. The download command may be generated when a user selects one or more images and hits a download feature located in the photo window.
[0075] In block 412 , the image formats required by the portable media device are determined. The determination may be made before the download or it may be made as part of the downloading process. In some cases, the host device stores a list of required formats for a variety of media devices. In other cases, the portable media device supplies the personal computer with required formats and image profiles, which describe how to format each image. In block 414 , new versions of the original image are created. That is, using the image profiles, the personal computer transcodes the original image into differently formatted images based on the image profile. By way of example, the transcoding may be performed by a multimedia technology such as QuickTime of Apple Computers Inc. of Cupertino, Calif. QuickTime is a powerful, cross platform, multimedia technology for manipulating, enhancing, and storing video, sound, animation, graphics, text, music, and the like. In Block 416 , the new versions of the original image and in some cases the original image are copied and stored onto the media device.
[0076] In block 418 , the media device is disconnected from the personal computer thereby allowing the images to be transported via the portable media device. In block 420 , a display command is generated on the media device during transport. In block 422 , one or more images are retrieved based on the display command. In block 424 , at least one of the retrieved images is presented. The retrieved image can be any of the stored images including the original and/or the new images. The retrieved image can be presented on the portable media device as for example though an LCD and/or it can be presented on an external display such as a television.
[0077] FIG. 7 is a block diagram of a media management system 500 , in accordance with one embodiment of the present invention. The media management system 500 includes a host computer 502 and a media player 504 . The host computer 502 is typically a personal computer. The host computer, among other conventional components, includes a management module 506 , which is a software module. The management module 506 provides for centralized management of media items not only on the host computer 502 but also on the media player 504 . More particularly, the management module 506 manages those media items stored in a media store 508 associated with the host computer 502 . The management module 506 also interacts with a media database 510 to store media information associated with the media items stored in the media store 508 .
[0078] The media items may correspond to audio, images or video items. The media information, on the other hand, pertains to characteristics or attributes of the media items. For example, in the case of audio or audiovisual media, the media information can include one or more of: title, album, track, artist, composer and genre. These types of media information are specific to particular media items. In addition, the media information can pertain to quality characteristics of the media items. Examples of quality characteristics of media items can include one or more of: bit rate, sample rate, equalizer setting, volume adjustment, start/stop and total time, etc.
[0079] Still further, the host computer 502 includes a play module 512 . The play module 512 is a software module that can be utilized to play certain media items stored in the media store 508 . The play module 412 can also utilize media information from the media database 510 . Typically, the media information of interest corresponds to the media items to be played by the play module 512 .
[0080] The host computer 502 also includes a communication module 514 that couples to a corresponding communication module 416 within the media player 504 . A connection or link 518 removeably couples the communication modules 514 and 416 . In one embodiment, the connection or link 518 is a cable that provides a data bus, such as a FIREWIRE™ bus or USB bus, which is well known in the art. In another embodiment, the connection or link 518 is a wireless channel or connection through a wireless network. Hence, depending on implementation, the communication modules 514 and 516 may communicate in a wired or wireless manner.
[0081] The media player 504 also includes a media store 520 that stores media items within the media player 504 . The media items being stored to the media store 520 are typically received over the connection or link 518 from the host computer 502 . More particularly, the management module 506 sends all or certain of those media items residing on the media store 508 over the connection or link 518 to the media store 520 within the media player 504 . Additionally, the corresponding media information for the media items that is also delivered to the media player 504 from the host computer 502 can be stored in a media database 522 . In this regard, certain media information from the media database 510 within the host computer 502 can be sent to the media database 522 within the media player 504 over the connection or link 518 . Still further, lists identifying certain of the media items can also be sent by the management module 506 over the connection or link 518 to the media store 520 or the media database 522 within the media player 504 .
[0082] Furthermore, the media player 504 includes a play module 524 that couples to the media store 520 and the media database 522 . The play module 524 is a software module that can be utilized to play certain media items stored in the media store 520 . The play module 524 can also utilize media information from the media database 422 . Typically, the media information of interest corresponds to the media items to be played by the play module 524 .
[0083] Hence, in one embodiment, the media player 504 has limited or no capability to manage media items on the media player 504 . However, the management module 506 within the host computer 502 can indirectly manage the media items residing on the media player 504 . For example, to “add” a media item to the media player 504 , the management module 506 serves to identify the media item to be added to the media player 504 from the media store 508 and then causes the identified media item to be delivered to the media player 504 . As another example, to “delete” a media item from the media player 504 , the management module 506 serves to identify the media item to be deleted from the media store 508 and then causes the identified media item to be deleted from the media player 504 . As still another example, if changes (i.e., alterations) to characteristics of a media item were made at the host computer 502 using the management module 506 , then such characteristics can also be carried over to the corresponding media item on the media player 504 . In one implementation, the additions, deletions and/or changes occur in a batch-like process during synchronization of the media items on the media player 504 with the media items on the host computer 502 .
[0084] In another embodiment, the media player 504 has limited or no capability to manage playlists on the media player 504 . However, the management module 506 within the host computer 502 through management of the playlists residing on the host computer can indirectly manage the playlists residing on the media player 504 . In this regard, additions, deletions or changes to playlists can be performed on the host computer 502 and then by carried over to the media player 404 when delivered thereto.
[0085] As previously noted, synchronization is a form of media management. The ability to automatically initiate synchronization was also previously discussed. Still further, however, the synchronization between devices can be restricted so as to prevent automatic synchronization when the host computer and media player do not recognize one another.
[0086] According to one embodiment, when a media player is first connected to a host computer (or even more generally when matching identifiers are not present), the user of the media player is queried as to whether the user desires to affiliate, assign or lock the media player to the host computer. When the user of the media player elects to affiliate, assign or lock the media player with the host computer, then a pseudo-random identifier is obtained and stored in either the media database or a file within both the host computer and the media player. In one implementation, the identifier is an identifier associated with (e.g., known or generated by) the host computer or its management module and such identifier is sent to and stored in the media player. In another implementation, the identifier is associated with (e.g., known or generated by) the media player and is sent to and stored in a file or media database of the host computer.
[0087] FIG. 8 is a block diagram of a media player 600 , in accordance with one embodiment of the present invention. The media player 600 includes a processor 602 that pertains to a microprocessor or controller for controlling the overall operation of the media player 600 . The media player 600 stores media data pertaining to media items in a file system 604 and a cache 606 . The file system 604 is, typically, a storage disk or a plurality of disks. The file system 604 typically provides high capacity storage capability for the media player 600 . However, since the access time to the file system 604 is relatively slow, the media player 600 can also include a cache 606 . The cache 606 is, for example, Random-Access Memory (RAM) provided by semiconductor memory. The relative access time to the cache 606 is substantially shorter than for the file system 604 . However, the cache 506 does not have the large storage capacity of the file system 604 . Further, the file system 504 , when active, consumes more power than does the cache 606 . The power consumption is often a concern when the media player 600 is a portable media player that is powered by a battery (not shown). The media player 600 also includes a RAM 620 and a Read-Only Memory (ROM) 622 . The ROM 622 can store programs, utilities or processes to be executed in a non-volatile manner. The RAM 620 provides volatile data storage, such as for the cache 606 .
[0088] The media player 600 also includes a user input device 608 that allows a user of the media player 600 to interact with the media player 600 . For example, the user input device 608 can take a variety of forms, such as a button, keypad, dial, etc. Still further, the media player 600 includes a display 610 (screen display) that can be controlled by the processor 602 to display information to the user. A data bus 611 can facilitate data transfer between at least the file system 604 , the cache 606 , the processor 602 , and the CODECs 612 .
[0089] In one embodiment, the media player 600 serves to store a plurality of media items in the file system 604 . The media items may for example correspond to audio (e.g., songs, books), images (e.g., photos) or videos (e.g., movies). When a user desires to have the media player play a particular media item, a list of available media items is typically displayed on the display 610 . Then, using the user input device 608 , a user can select one of the available media items. The processor 602 , upon receiving a selection of a particular media item, supplies the media data (e.g., audio file, image file or video file) for the particular media item to the appropriate device. For audio items, the processor supplies the media item to a coder/decoder (CODEC) 612 . The CODEC 612 then produces analog output signals for a speaker 614 . The speaker 614 can be a speaker internal to the media player 600 or external to the media player 600 . For example, headphones or earphones that connect to the media player 600 would be considered an external speaker.
[0090] For visual items, the processor supplies the media item to the display 610 . The display may for example be a liquid crystal display (LCD) that is integral with the media player. Alternatively, the display may be an external display such as a CRT or LCD, or a television of any particular type. In some cases, the processor is configured to supply media data to both an integrated display and an external display. In cases such as this, the media data displayed on both displays may be the same of it may be different. In the later case, for example, the internal display may include a slide show interface showing the previous image, the next image and the image currently being displayed on the external display.
[0091] The media player 600 also includes a network/bus interface 616 that couples to a data link 618 . The data link 618 allows the media player 600 to couple to a host computer. The data link 618 can be provided over a wired connection or a wireless connection. In the case of a wireless connection, the network/bus interface 616 can include a wireless transceiver.
[0092] In another embodiment, a media player can be used with a docking station. The docking station can provide wireless communication capability (e.g., wireless transceiver) for the media player, such that the media player can communicate with a host device using the wireless communication capability when docked at the docking station. The docking station may or may not be itself portable.
[0093] The wireless network, connection or channel can be radio-frequency based, so as to not require line-of-sight arrangement between sending and receiving devices. Hence, synchronization can be achieved while a media player remains in a bag, vehicle or other container.
[0094] The host device can also be a media player. In such case, the synchronization of media items can between two media players.
[0095] The various aspects, embodiments, implementations or features of the invention can be used separately or in any combination.
[0096] The invention is preferably implemented by software, but can also be implemented in hardware or a combination of hardware and software. The invention can also be embodied as computer readable code on a computer readable medium. The computer readable medium is any data storage device that can store data which can thereafter be read by a computer system. Examples of the computer readable medium include read-only memory, random-access memory, CD-ROMs, DVDs, magnetic tape, optical data storage devices, and carrier waves. The computer readable medium can also be distributed over network-coupled computer systems so that the computer readable code is stored and executed in a distributed fashion.
[0097] FIG. 9 is perspective view of a handheld computing device 700 , in accordance with one embodiment of the present invention. The computing device 700 is capable of processing data and more particularly media such as audio, video, images, etc. By way of example, the computing device 700 may generally correspond to a music player, game player, video player, camera, cell phone, personal digital assistant (PDA), and/or the like. With regards to being handheld, the computing device 700 can be operated solely by the user's hand(s), i.e., no reference surface such as a desktop is needed. In some cases, the handheld device is sized for placement into a pocket of the user. By being pocket sized, the user does not have to directly carry the device and therefore the device can be taken almost anywhere the user travels (e.g., the user is not limited by carrying a large, bulky and heavy device).
[0098] As shown, the computing device 700 includes a housing 712 that encloses and supports internally various electrical components (including integrated circuit chips and other circuitry) to provide computing operations for the device. The integrated circuit chips and other circuitry may include a microprocessor, memory, a battery, and various input/output (I/O) support circuitry. In most cases, the microprocessor executes instructions and carries out operations associated with the computing device. For example, using instructions retrieved for example from memory, the microprocessor may control the reception and manipulation of input and output data between components of the computing device 700 . In fact, the microprocessor may work with an operating system to execute computer code and produce and use data stored in memory. By way of example, the memory may include a hard drive, flash memory, Read-Only Memory (ROM), Random-Access Memory (RAM) and/or the like.
[0099] The computing device 700 also includes a display 714 . The display 714 , which is assembled within the housing 712 and which is visible through an opening in the housing 712 , is used to display a graphical user interface (GUI) as well as other information to the user (e.g., text, objects, graphics). The display 714 generally takes the form of a flat panel display such as a liquid crystal display (LCD).
[0100] The computing device 700 also includes one or more input devices 718 configured to transfer data from the outside world into the computing device 700 . The input devices 718 may for example be used to perform tracking/scrolling, to make selections or to issue commands in the computing device 700 . By way of example, the input devices 718 may correspond to keypads, joysticks, touch screens, touch pads, track balls, wheels, buttons, switches, and/or the like. In the illustrated embodiment, the computing device 700 includes a touch pad 718 A and a plurality of buttons 718 B, which are assembled within the housing 712 and which are accessible through openings in the housing 712 .
[0101] The computing device 700 may include one or more switches 720 including power switches, hold switches, and the like. Furthermore, the device 700 may include one or more connectors 722 including data ports and power terminals 722 A and B, as well as audio and/or video jacks 722 C.
[0102] In the illustrated embodiment, the computing device 700 is a pocket sized hand held music/photo player that allows a user to store a large collection of music and photos, and to listen to this music and view the photos on the go (e.g., while working, traveling, exercising, etc.). In such a case, the memory may contain media management software having both music playing and photo displaying capabilities. Furthermore, the GUI may visually provide music and photo menus, as well as music and photo controls to the user. Moreover, the touch pad may provide scrolling functions, which allow a user to traverse through menus or controls on the GUI as well as to browse through a list of songs or photos, and the buttons may provide button functions that open a menu, play a song, display a photo, fast forward through a song, seek through a playlist or album and/or the like. In addition, the music/photo player typically includes an audio jack for outputting audio, a video jack for outputting photos and videos and a data port for transmitting and receiving media data (and other data.) to and from a host device. In some cases, the audio and video jack are combined into a single jack. By way of example, the music photo player may correspond to the iPod® series music players manufactured by Apple Computer of Cupertino, Calif.
[0103] FIG. 10 is a media device operational method 800 , in accordance with one embodiment of the present invention. The operational method 800 may for example be performed on a portable media device, and more particularly a portable music/photo player. The method 800 generally begins at block 802 where a main menu is presented to a user on a display. See for example FIG. 11A , which shows the main menu 850 presented on the display. The main menu 850 generally includes several options 852 associated with operating the media device. By way of example, the main menu 850 may include options 852 such as music, photos, extras, settings, shuffle songs and backlight. In most cases, each of the options 852 includes its own sub menu of sub options, which are associated with the main option. Each of these sub options may open another sub menu of sub options or they may initiate an action. By way of example, the music submenu may include music library, playlist, and browse options and the photo sub menu may include photo library, album and slide show setting options
[0104] Following block 802 , the method proceeds to block 804 where a determination is made as to whether the photo option was selected. If not, the method waits or proceeds back to block 802 . If so (as shown by the slider bar in FIG. 11A ), the method proceeds to block 806 where the photo sub menu is presented to the user on the display. By way of example, see FIG. 11B which shows the photo sub menu 854 presented on the display. The photo sub menu 854 may include one or more photo options 856 , which may represent different modes of photo viewing, and which may give the user the ability to change settings associated with photo viewing. In the illustrated embodiment, the sub menu 854 includes a photo library option, one or more album options and a photo settings options.
[0105] Following block 806 , the method proceeds to block 808 where a determination is made as to whether or not the library option is selected. If the library option is selected, the method proceeds to block 810 where all the stored images are retrieved. Thereafter, in block 812 , the images are displayed based on predetermined settings. If the library is not selected, the method proceeds to block 814 where a determination is made as to whether or not the album option is selected. If the album option is selected, the method proceeds to block 816 where only the album images are retrieved. Thereafter, in block 818 , the images are displayed based on predetermined settings.
[0106] In either of blocks 812 and 818 , the entire group or some portion of the retrieved group can be displayed. The amount displayed generally depends on the number of images inside the library or album. If it is large, the screen may not be capable of displaying all of the images at once. In cases such as these, some of the images are kept out of the viewing area until the user decides to pull them up. The manner in which they are displayed generally depends on the desired display configuration established in the settings menu.
[0107] In browse mode, a large group of tiny thumbnails 858 are displayed in columns and rows as shown in FIG. 11C . The user can browse through the tiny thumbnails 858 via a scrolling action either image by image or row by row or column by column, etc. As the user scrolls through the images a new set of data (e.g., images or line of images) is brought into view in the viewing area. In most cases, once the viewing area is full, each new set of data appears at the edge of the viewing area and all other sets of data move over one position. That is, the new set of data appears for each set of data that moves out of the viewing area. In some cases, when a particular image is selected while browsing, the full screen version of that image is displayed as shown in FIG. 11E . Alternatively, the configuration shown in FIG. 11D may be displayed with the current image being the medium thumbnail of the image selected, and the previous and next images being the small thumbnails of the images located next to the image selected.
[0108] In slide show mode, only the previous, current, and next images are displayed. The previous and next images may be small thumbnails 860 while the current image may be a medium thumbnail 862 as shown in FIG. 11D . The user may traverse through the retrieved images by clicking a forward or back button, i.e., the forward button causes the current image to move to the previous image, the next image to move to the current image, and a new image to move into the next image. In some cases, when a the current image is selected while traversing through the slide show, the full screen version 864 of that image is displayed as shown in FIG. 11E .
[0109] In TV mode, the TV thumbnail(s) 866 is outputted to a TV for display as shown in FIG. 11F . The TV display may mimic what is being shown on the media player. For example, the TV display may display any of the previous screen shots ( FIGS. 11C , 11 D, 11 E) or variations thereof. During a slide show, for example, the TV screen image may be based on the same original image as the current image in the slide show window.
[0110] If the album option is not selected, the method proceeds to block 820 where a determination is made as to whether or not the setting option is selected. If the setting option is selected, the method proceeds to block 822 where a setting menu is presented to the user on the display. The setting menu may include control settings pertaining to one or more display events. In fact, the setting menu may serve as a control panel for reviewing and/or customizing the control settings, i.e., the user may quickly and conveniently review the control settings and make changes thereto. Once the user saves the changes, the modified control settings will be employed to handle future display events. By way of example, the settings may include features that allow a user to assign music tracks to albums, to turn the assigned music on/off, to turn TV out on/off, to choose between modes, etc. The settings may also allow a user to select slide shows and whether to display the images in full screen or slide show mode and whether to show the images in random or sequenced order as well as to end or repeat when finished.
[0111] While this invention has been described in terms of several preferred embodiments, there are alterations, permutations, and equivalents, which fall within the scope of this invention. It should also be noted that there are many alternative ways of implementing the methods and apparatuses of the present invention. For example, although the invention is primarily directed at images, it should be noted that it may also be applied to music. In the case of music, different versions of the same song may be created, downloaded and stored. The different versions can be based on a variety of things including for example adjustments made to characteristics of the song (e.g., tempo, pitch), adding or removing elements of the song (e.g., voice or instrument), and/or the like. It is therefore intended that the following appended claims be interpreted as including all such alterations, permutations, and equivalents as fall within the true spirit and scope of the present invention.
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Methods and system for transferring images between devices is disclosed. For example, differently scaled images by a host device may automatically and/or selectively be transferred to a media player for display. In turn, appropriately scaled images may be transferred automatically and/or selectively to another display device for example a TV, camera or printer. The selectivity may occur either at the host level or at the player level.
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CROSS-REFERENCE TO RELATED APPLICATION
None.
BACKGROUND OF THE INVENTION
The present invention relates to a system and method for detecting the presence of water. More particularly, it relates to a solid-state electronic circuit for detecting the presence of water and a method for using the circuit.
Undetected water leaks can cause property damage, equipment shutdowns, and expensive clean-up costs. Furthermore, these leaks can create a hazardous working environment for persons in the vicinity of a leak. Typical uses for water detection systems include placement beneath air conditioning systems to detect condensation overflow, placement in homes to detect water overflow onto the floor from a sump, and placement in selected locations in various-commercial processes to detect undesired water leaks and overflows.
One type of water detection system, a closed-circuit-type system, includes a sensor having two conductive probes. The sensor is placed at the location that water detection is desired, and the presence of water is detected when the water closes an electrical circuit by connecting the two probes. This closed-circuit-type water detection system is capable of detecting a thin film of water. The amount of water necessary for proper operation of this type of water detection system depends upon the sensitivity of the circuit and its ability to detect a flow of electrons between the two probes.
Closed-circuit-type water detection systems, known in the prior art, all have shortcomings that limit their effectiveness, reliability, and safety. One system uses a high voltage applied to the probes in a series circuit, along with a relay. While the high voltage may help to detect the presence of smaller amounts of water, it has several disadvantages, including creating an unsafe condition for persons in the operating environment. Other systems apply high current levels to the probes, which can result in an unsafe operating condition and can cause deterioration of the probes due to electrolysis. Still other water detection systems use highly sensitive solid-state circuitry, but the design limits the possible distance between the sensor and an alarm. This distance is limited because the use of long wires creates a voltage drop, a capacitive effect, and an inductive effect which can act to create false alarms.
There remains a need in the art for an effective and safe water detection system that can detect very small amounts of water, and for a system that allows the sensors to be placed at substantial distances from an alarm.
BRIEF SUMMARY OF THE INVENTION
The present invention is a water detection system for detecting water and activating an alarm. In one embodiment, the system includes a sensor and an alarm. The sensor includes a first probe and a second probe coupled to an amplifying and switching circuit. The sensor further includes first and second terminals located across the amplifying and switching circuit. The first probe and second probe are configured to contact any of the liquid present in the operating environment. The alarm housing includes an alarm circuit for activating an alarm and is electrically coupled to the first and second terminals of the sensor.
While several alternative embodiments are disclosed, still other embodiments of the present invention will become apparent to those skilled in the art from the following detailed description, wherein is shown and described only the embodiments of the invention, by way of illustration, of the best modes contemplated for carrying out the invention. As will be realized, the invention is capable of modification in various obvious aspects, all without departing from the spirit and scope of the present invention.
Accordingly, the drawings and detailed description are to be regarded as illustrative in nature and not restrictive.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a block diagram showing components of a water detection system according to a first embodiment of the present invention.
FIG. 2 is a schematic diagram showing the circuitry of the water detection system shown in FIG. 1 .
FIG. 3 is a perspective view of a water detection system according to a second embodiment of the present invention.
FIG. 4 is a schematic diagram of the circuitry of the second embodiment of the present invention.
DETAILED DESCRIPTION
FIG. 1 is a block diagram of a water detection system 10 according to a first embodiment of the present invention. As shown in FIG. 1, the water detection system 10 includes a voltage source 12 , a relay coil 14 , and a water sensor 16 , connected in series. The voltage source 12 provides the electricity to power the circuit. The relay coil 14 activates when a sufficient level of current flows through the circuit and operates to control an alarm or other auxiliary device. The water sensor 16 is placed at the detection site and operates by closing a circuit upon detection of the presence of water. In one embodiment of the present invention, all of the components shown in FIG. 1 are contained within one housing, which is then placed directly at the detection site. In another embodiment of the present invention, the voltage source 12 and the relay coil 14 are located in a separate housing and are coupled to the water sensor 16 by an electrical conductor. The voltage source 12 is typically either a battery or a direct current power supply.
FIG. 2 is a schematic diagram showing the water detection system 10 . As shown near the top of FIG. 2, the voltage source 12 includes a first conductor 18 a , coupled to a negative terminal, and a second conductor 18 b , coupled to a positive terminal. As shown near the middle of FIG. 2, the water sensor 16 includes a first terminal 20 a and a second terminal 20 b . The first conductor 18 a is coupled to the first terminal 20 a of the water sensor 16 . The second conductor 18 b is coupled to the relay coil 14 , which in turn is coupled to the second terminal 20 b of the water sensor 16 .
As shown near the bottom of FIG. 2, the water sensor 16 includes a first probe 22 a , a second probe 22 b , a first resistor 24 a , a second resistor 24 b , a transistor circuit 26 , a capacitor 28 , and a diode 30 . The probes 22 a and 22 b act as the terminals of a switch that is closed by the presence of water. In one embodiment, the probes 22 a and 22 b are placed about one half inch apart. The resistors 24 a and 24 b are biasing resistors and have appropriate values to allow proper operation of the transistor circuit 26 . The values of the resistors 24 a and 24 b control the sensitivity of the transistor circuit 26 , and one of ordinary skill in the art can select appropriate resistance values. The transistor circuit 26 is connected across the probes 22 a and 22 b . The capacitor 28 acts to smooth any ripple voltage in the signal coming from the voltage source 12 . The diode 30 acts to prevent the circuit from damage if the terminals of the voltage source 12 are connected to the water sensor 16 in reverse polarity.
In one embodiment of the present invention, the water detection system is contained within one housing, which is placed at the water detection site. In other words, each of the voltage source 12 , the relay coil 14 , and the water sensor 16 , are placed within the same housing. The relay coil 14 includes additional leads (not shown) that couple to an alarm device.
During operation of the water detection system 10 of the present invention, the water detection system 10 is placed at the water detection site. When no water is present, or insufficient water is present to create a conduction path between the probes 22 a and 22 b , no current from the voltage source 12 will flow in the circuit. At this point, the electric potential of the voltage source 12 between the positive and negative terminals is present across first terminal 20 a and second terminal 20 b , as the potential will move through the relay coil 14 . This electric potential then enters the water sensor 16 where the diode 30 prevents a reverse polarity connection, and the capacitor 28 smooths the signal. This smoothed voltage signal is then communicated to the emitter and collector terminals of the transistor circuit 26 . The electric potential is further transmitted to the probes 22 a and 22 b . At this time, however, as no water is present, the current does not flow through the circuit, as it is open at the probes 22 a and 22 b.
When water is present between the probes 22 a and 22 b , it will close the circuit and cause current to flow. Because of the high resistance of water, only a small amount of current will flow. In the case of distilled water, it is possible that only a very small level of current will flow through the circuit. This current flow is detected at the base of the transistor circuit 26 .
As shown in FIG. 2, in the center of the water sensor 16 , the transistor circuit 26 includes an amplifying transistor 32 and a switching transistor 34 . The small current flow, now present across the probes 22 a and 22 b , reaches the base of the amplifying transistor 32 , which then operates to allow a current to flow from the voltage source 12 through the amplifying transistor 32 and out its emitter. The emitter of the amplifying transistor 32 , as shown in FIG. 2, is coupled to the base of the switching transistor 34 . This current flow, reaching the base of the switching transistor 34 , allows a larger current from the voltage source 12 to be amplified through the switching transistor 34 . When the switching transistor 34 is activated, it allows a larger amount of current to flow through the circuit from the voltage source 12 , thereby effectively acting to close a switch between the first terminal 20 a and the second terminal 20 b . In one embodiment of the present invention, the transistor circuit 26 is a Darlington transistor, as known to those of skill in the art.
The switching transistor 34 , however, has an internal resistance which allows some amount of the current to continue to flow, through the probes 22 a and 22 b , to the base of the amplifying transistor 32 , which ensures that the switching transistor 34 remains active as long as water is present. At this point, a majority of the current from the voltage source 12 will flow through the relay 14 and the switching transistor 34 , thereby activating the relay.
In one embodiment, the relay coil 14 needs seventy percent of its rated voltage to activate. Therefore, any extremely small current that are amplified by the transistor circuit 26 do not cause the relay coil 14 to activate. Once the current level reach the necessary level, the relay coil 14 is activated, and remains activated until it is reduced to five percent of its rated voltage. Thus, once the relay coil 14 is activated, the voltage at the first terminal 20 a and the second terminal 20 b can vary widely without causing the relay coil 14 to deactivate.
In one embodiment of the present invention, the circuitry components of the water sensor 16 are encapsulated in epoxy, and the entire housing is sealed to prevent water damage.
FIG. 3 is a perspective view of a water detection system 100 according to a second embodiment of the present invention. The water detection system 100 includes an alarm panel 102 , a water sensor 104 , and a power supply 106 . The alarm panel 102 is electrically coupled to the water sensor 104 . The alarm panel 102 is further electrically coupled to the power supply 106 . The power supply 106 , in one embodiment, is designed to convert one hundred twenty volts alternating current into nine volts direct current, and is plugged into a standard wall receptacle. In other embodiments, the power supply 106 is designed to convert power having a wide variety of voltages and frequencies to nine volts direct current. This allows the water detection system 100 to be used with power outlets around the world. In another embodiment, the power supply 106 is a battery. The power supply 106 provides the power needed for operation of the water detection system 100 . The design of the present invention allows the water sensor 104 to be placed at a large distance from the alarm panel 102 , by using conductive wire. Excessive wire length is not a problem, as it is in the prior art, because the circuitry that performs the sensing is located in the water sensor 104 . Therefore, false positive signals are not created by long wire length, in the design of the present invention.
The alarm panel 102 , as shown near the top of FIG. 3, includes an audible alarm 108 , abnormal indicator light 110 , an alarm indicator light 112 , a test switch 114 , and a silence switch 116 , all contained within a housing 118 . The components of the alarm panel 102 will be described in greater detail below with reference to the circuit diagram shown in FIG. 4 . The water sensor 104 includes probes 120 A and 120 B on a bottom surface of a housing 122 .
FIG. 4 shows a circuit schematic for the water detection system 100 of the present invention. As shown near the top of FIG. 4, the alarm panel 102 is connected to the power supply 106 . Power from the power supply 106 flows into the circuit as indicated. The circuitry of the alarm panel 102 include an alarm relay coil 124 and a silence relay coil 126 . The alarm relay coil 124 includes a first set of contacts 128 and a second set of contacts 130 . The first set of contacts 128 includes normally closed contacts 128 a and normally open contacts 128 b . The second set of contacts 130 include normally closed contacts 130 a and normally open contacts 130 b . The silence relay coil 126 includes a first set of contacts 132 and a second set of contacts 134 . The first set of contacts 132 includes normally closed contacts 132 a and normally open contacts 132 b . The second set of contacts 134 includes normally closed contacts 134 a and normally open contacts 134 b . The circuitry of the alarm panel 102 further includes a battery 136 connected to the negative terminal of the power supply 106 , by a first diode 138 , when external voltage is present at the power supply 106 . A second diode 140 connects the battery 136 to the positive terminal of the power supply 106 when external voltage is absent. Also, when external voltage is absent, the first diode 138 acts as an open circuit to prevent the battery 136 from energizing the normal indicator light 110 . This indicates to the operator that power has failed, and also acts to conserve the energy of the battery 136 . As shown near the bottom of FIG. 4, the wires 142 a and 142 b are designed for coupling to the water sensor 104 . The internal circuitry of the water sensor 104 is not shown in FIG. 3, because it is the same as that of the water sensor 16 shown in FIG. 2 .
During operation, when no water is present across the probes 22 a and 22 b of the water sensor 104 , power from the power supply 106 will flow through the normal indicator light 110 , the normally closed contacts 128 a , and the normally closed contacts 132 a . This will cause the normal indicator light 110 to glow, indicating a normal operating condition. At this time, current is not flowing through any other portion of the circuit in the alarm panel 102 . As explained above, with reference to FIG. 2, the electric potential from the power supply 106 is transmitted to the terminals 20 a and 20 b of the water sensor 104 through the alarm relay coil 124 . When water is present across the terminals 22 a and 22 b , the water sensor 104 will operate, as described above with reference to FIG. 2, and current will begin to flow through the water sensor 104 circuitry. At this point, with water present between the probes 22 a and 22 b , the water sensor 104 essentially acts to close the path between contacts 20 a and 20 b and allow current to flow through the circuitry in the alarm panel 102 .
This closed path allows current to flow through the alarm indicator light 112 , causing it to glow, indicating an alarm condition. It further allows current to flow through the alarm relay coil 124 . Once current reaches seventy percent of the rated level of the alarm relay coil 124 , it will activate. Because the alarm relay coil 124 is not activated until seventy percent of its rated level is reached, it acts to cancel out minor current fluctuations that may be present in the system. The alarm relay coil 124 is not activated until it a sufficiently high current level is reached. When the alarm relay coil 124 activates the first set of contacts 128 switch so that the normally closed contacts 128 a open, and the normally open contacts 128 b close, this switch causes the normal indicator light 110 to shut off, indicating that water has been detected. It also allows current to flow through the buzzer 108 to create an audible alarm signal. The second set of contacts 130 of the alarm relay coil 124 , as shown near the bottom right in FIG. 4, are intended for use with an auxiliary device. For instance, they could be connected to a device that is the cause of the water leak and the leak detection will act to shut down the device.
If the operator of the water detection system 10 wishes to shut off the audible alarm created by the buzzer 108 , he may press the silence switch 116 . Pressing the silence switch 116 will energize the silence relay coil 126 , causing actuation of its first set of contacts 132 and its second set of contacts 134 . The normally closed contacts 132 a will open and the normally open contacts 132 b will close. Opening of contacts 132 a will cause the buzzer 108 to be cut off from the power supply 106 . The closing of the normally open contacts 132 b causes the silence relay coil 126 to latch on as it creates a coupling to the power supply 106 even after the silence switch 116 is released. The activation of the silence relay coil 126 will also cause the normally open contact 134 b to close and the normally closed contact 134 a to open. The opening of the normally closed contacts 134 a will deactivate the alarm relay coil 124 . The current will now flow through the silence relay coil 126 instead of the alarm relay coil 124 .
When water is removed from the probes 22 a and 24 b , the current will stop flowing through the water sensor 104 and the silence relay coil 126 will deactivate, returning the system to its initial state. In one embodiment, the circuitry of the alarm panel 102 includes a test switch 114 which may be used to test the various indicators on the alarm panel 102 .
In an alternative embodiment of the present invention, the alarm relay coil 124 is located in a housing separate from the alarm panel 102 . In another embodiment of the present invention, multiple water sensors 104 can be connected to the alarm panel 102 to provide zone protection. The circuitry of the alarm panel 102 is capable of monitoring multiple water detectors 104 by connecting each of the water detectors to the terminals 20 a and 20 b in parallel. The presence of water at any set of probes of any of the water sensors 104 will cause the alarm circuitry to activate. The design of the present invention allows the use of multiple water detectors 104 , because the water detectors 104 do not draw current until water is present. Therefore, there is essentially no limit on the number of water detectors 104 than can be used. In another of the present invention, a float switch is connected in parallel with the water sensor 104 . When either the water sensor 104 or the float switch detects the presence of water, or water at a specified level, it will activate the alarm circuitry.
While the above description describes the present invention with reference to water detection, it should be appreciated that the present invention may also be used to detect the presence or the level of other conductive liquids. Although the present invention has been described with reference to preferred embodiments, persons skilled in the art will recognize that changes may be made in form and detail without departing from the spirit and scope of the invention.
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A water detection system for detecting water and activating an alarm is provided. The water detection system includes an alarm relay and a water sensor. The water sensor includes a solid state switching and amplifying circuit for detecting low levels of current flow and amplifying the signal to activate the alarm relay. In one embodiment, the water detection system further includes an alarm panel, including visual and audible alarms activated by the alarm relay. In one embodiment, the water detection system includes multiple water sensors for providing zone protection. In one embodiment, the alarm relay is configured to shut-down the device causing the presence of water. A method for implementation of the water detection system is also provided.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The subject invention generally pertains to sectional doors and more specifically to a release mechanism for such a door.
2. Description of Related Art
A sectional door typically includes a series of panels whose adjacent horizontal edges are each pivotally connected by a row of hinges. As the door opens or closes, the door panels travel along two lateral tracks that in one configuration curve between horizontal and vertical. To close the door, the tracks guide the panels to a vertical position. When the door opens, the hinges allow the panels to curve around onto horizontal sections of the tracks, where the door panels store horizontally overhead. In other configurations, the sectional door maintains a generally vertical, planar configuration and is stored more directly above the doorway. Such doors, regardless of their configuration, can be powered up or down or can be manually operated. To ease the operation of the door, a torsion spring is often used to offset the weight of the door panels. Sectional doors are commonly used as residential garage doors; however, they are also often used in warehouses and other industrial buildings.
When used in high-traffic industrial applications, sectional doors are very susceptible to being struck by large trucks, trailers, forklifts and other vehicles passing through the doorway. There are different reasons why vehicles collide with doors. One of the more common causes is a door's torsion spring becoming weak with age or not being properly preloaded. This can allow a door to droop down into the doorway from a fully open position or not open fully at all. In such cases, an upper edge of a vehicle traveling through the doorway may strike the lower portion of the drooping door, which can damage one or more door panels, as well as damage door-mounting hardware, such as hinges, rollers and track.
Doors are also often installed adjacent to a dock leveler of a loading dock. When the door is closed, such doors can be damaged as material handling equipment stage loads on the dock leveler. For instance, a forklift may accidentally push a load up against the door.
Consequently, some doors are provided with some type of breakaway feature that allows a door to give way to a collision without being damaged. For example, a sectional door described in U.S. Pat. No. 5,727,614 includes a track-following roller that can break away from its mounting bracket in reaction to a collision. After the collision, the roller can be reattached to the bracket. The breakaway device, however, has its limitations. Upon breaking away, the roller can completely separate from the mounting bracket, thus an impact could throw the roller where it may be difficult to find. This is particularly true for a loading dock door that is installed adjacent to a dock leveler. In such cases, the roller may fall into a pit that is underneath a conventional dock leveler or fall into some snow that may be just outside the building. It also appears that the '614 device breaks away at a predetermined force, which cannot be readily adjusted or altered once the door is installed. Depending on the application, it may be desirable to have a door that breaks away in one direction easier than another. For instance, for heavier doors, it may be desirable to have a higher breakaway force in one direction (from outside to inside), so that the door does not break away under its own weight when fully open and stored overhead. It some cases, for example, it may be beneficial to have a door whose breakaway feature only acts in one direction. In windy areas, it may be better to have a door that only breaks away in an outward direction to avoid the door giving way to strong winds.
Another breakaway device, shown in U.S. Pat. No. 6,039,106 does include a means for adjusting the breakaway force. The breakaway force is adjusted by turning a setscrew, which adjusts the pressure that a spring-loaded plunger exerts against a detent of a track-following guide member. Under sufficient breakaway force, the guide member is able to swing its detent out from underneath the force of the plunger; however, the guide member does not completely separate from the plunger. The swinging motion also releases the guide member out from within the track, which releases the door to avoid damage. Although the device has an adjustable breakaway, it appears that the breakaway force is the same in both directions and that the device cannot be readily locked to disable the breakaway feature.
Other examples of breakaway mechanisms are shown in U.S. Pat. Nos. 5,392,836 and 6,053,237. These devices; however, share some of the same limitations of the other breakaway devices that have already been discussed.
SUMMARY OF THE INVENTION
In order to provide a versatile breakaway device for a sectional door, a release mechanism includes a first member for releasably coupling a track-following guide member to a bracket connected to the door. The first member may be able to snap into and out of the guide member to allow the guide member to move between an operative position where the guide member engages the track and a dislodged position where the guide member separates from the track, or the first member may engage or disengage the guide member in other ways.
In some embodiments, the guide member includes a roller.
In some embodiments, the release mechanism releases easier in one direction than another.
In some embodiments, the release mechanism is selectively reconfigureable to a releasable mode and a non-releasable mode.
In some embodiments, the release mechanism is selectively reconfigureable by selectively inserting a pin in different holes.
In some embodiments, the release mechanism includes a releasable pin that is U-shaped.
In some embodiments, the release mechanism is capable of being reset to its operative position without the use of tools.
In some embodiments, the first member and the guide member completely separate from each other upon moving from the operative position to the dislodged position.
In some embodiments, the guide member is pivotal about the retaining member.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a front view of one embodiment of an overhead-storing sectional door in a partially open position, with the door being viewed from inside a building and looking out.
FIG. 2 is a cross-sectional view taken along line 2 — 2 of FIG. 1 .
FIG. 3 is a front view of one example of a door panel hinge.
FIG. 4 is an end view of the hinge of FIG. 3 .
FIG. 5 is an end view of one embodiment of a release mechanism.
FIG. 6 is a front view of FIG. 5 .
FIG. 7 is a top view of a guide member of the release mechanism shown in FIG. 6 .
FIG. 8 is a cross-sectional view taken along line 8 — 8 of FIG. 1, showing a release mechanism is an operative position.
FIG. 9 is similar to FIG. 8, but with the release mechanism in a dislodged position.
FIG. 10 is similar to FIG. 8, but with the pins of the release mechanism in a different position.
FIG. 11 is similar to FIG. 10, but with the release mechanism in a dislodged position.
FIG. 12 is a top view of a guide member that provides a release mechanism with bi-directional breakaway.
FIG. 13 is a perspective view of a retainer being inserted into a block of a guide member to provide unidirectional breakaway.
FIG. 14 is similar to FIG. 13, but with the retainer being inserted into the block so as to disable the breakaway feature.
FIG. 15 is a top view of the block of FIGS. 13 and 14 with a roller inserted in the block.
FIG. 16 is similar to FIG. 8, but of another release mechanism in an operative position.
FIG. 17 is the release mechanism of FIG. 16, but with the release mechanism in a dislodged position.
FIG. 18 is a cross-sectional view taken along line 18 — 18 of FIG. 16 .
FIG. 19 is similar to FIG. 1, but with the door closed.
FIG. 20 is a cross-sectional view taken along line 20 — 20 of FIG. 19 (with some features pertaining to the rollers and release mechanism omitted for clarity).
FIG. 21 is a cross-sectional view taken along line 21 — 21 of FIG. 1 (with some features pertaining to the rollers and release mechanism omitted for clarity).
DESCRIPTION OF THE PREFERRED EMBODIMENT
A sectional door 10 , shown partially open in FIGS. 1 and 2, includes a series of door panels 12 , 14 , 16 and 18 that are interconnected along their adjacent horizontal edges by hinges 20 . As door 10 opens or closes relative to a doorway 22 defined by a wall 23 , guide members 24 guide the movement of the panels along two lateral tracks 26 and 28 . In this example, tracks 26 and 28 curve between horizontal and vertical; however, it is well within the scope of the invention to have tracks 26 and 28 run generally linearly or only curve slightly, so that when the door opens, the door panels move above doorway 22 while remaining in a generally vertical or slightly angled orientation. To close door 10 , the vertical sections of tracks 26 and 28 guide the panels to a vertical position across doorway 22 , as indicated by the positions of panels 12 and 14 . When door 10 opens, hinges 20 allow the panels to curve around onto the horizontal sections of tracks 26 and 28 , where the door panels store horizontally overhead, as indicated by the position of panel 18 .
The actual structure of panels 12 , 14 , 16 and 18 can vary from one door to another, vary among panels of the same door, or be the same for each panel of the same door and still remain well within the scope of the invention. A door panel according to this embodiment comprises a foam core 30 protected by a tough outer shell 32 . Shell 32 may comprise a rectangular metal frame that supports two parallel face panels. The metal frame can also serve as a strong base to which door hardware can be mounted, such as hinges 20 and pliable seals 34 . Seals 34 help seal the gap between adjacent door panels. In some cases, hinges 20 comprise a hinge pin 36 that pivotally couples two U-shaped hinge plates 38 and 40 , as shown in FIGS. 3 and 4. Hinge plates 38 and 40 can be fastened to the edge of a door panel by way of fasteners 42 . It should be noted; however, that the present invention can be applied to doors with other types of hinges; different types of seals (or no seals); and door panels of various other designs, such as those that are solid or hollow.
The primary focus of the invention is to provide a sectional door with a feature that helps protect a door that may be subjected to excessive forces, such as forces that occur during an impact. Such a feature can be provided by a release mechanism 44 that allows one or more door panels (or even just part of one panel) to move away from its guide tracks in response to a sufficient breakaway force being exerted against the door.
In a preferred embodiment, release mechanism 44 includes a U-shaped bracket 46 that attaches adjacent an edge (preferably to the frame) of a panel (e.g., panel 12 ) by way of a fastener 48 , as shown in FIGS. 5 and 6. Between two flanges 50 and 52 , bracket 46 supports guide member 24 , which in this case, includes a nylon block 54 that supports a shaft 56 of a roller 58 (or some other type of track-guided element, not limited to only those that roll). In some cases, the axial position of shaft 56 can be limited or restrained by some feature such as a conventional cotter pin, C-clip, E-clip, push nut, sleeve 102 (to be explained further with reference to FIG. 15) or in the case of the preferred embodiment, a setscrew 60 that clamps against the side of shaft 56 .
To render mechanism 44 releasable under impact (or some other sufficient force applied in the direction indicated by arrow 62 of FIG. 9 ), block 54 is releasably coupled to bracket 46 in a manner that allows guide member 24 to move from an operative position of FIG. 8 to a dislodged position of FIG. 9 . At the same time, block 54 is also coupled to bracket 46 such that the guide member 24 stays attached to the panel even after moving to the dislodged position. Toward that end for release mechanism 44 , elongated elements, such as pins 64 and 66 couple block 54 to bracket 46 . The term, “pin” refers to any elongated element, examples of which include, but are not limited to, a clevis pin, roll pin, cotter pin, dowel, screw, rivet, nail, threaded rod, etc. Although pins 64 and 66 are used in a preferred embodiment, other elongated elements that do not necessarily resemble a pin are also well within the scope of the invention. Pin 64 extends through two aligned holes in flanges 50 and 52 , with a portion 64 ′ (FIG. 6) of pin 64 extending through a hole 68 (FIG. 7) in block 54 . In this way, guide member 24 is pivotally mounted to the panel. Alternatively, opposite ends of pin 64 can be welded or otherwise attached to flanges 50 and 52 without the use of holes in the flanges of bracket 46 . In a similar manner, pin 66 also extends through two aligned holes in flanges 50 and 52 ; however, to provide release mechanism 44 with the ability to break away, a portion 66 ′ (FIG. 6) of pin 66 is received within a slot 70 in block 54 . In this way, a releasable coupling is created between guide member 24 and panel 12 , wherein pin 66 is a first member adapted for selective engagement with the guide member 24 to form a releasable coupling that allows the guide member to move from the engaged to the dislodged position by virtue of complete separation between guide member 24 and pin 66 in response to a force exerted in direction 62 , which is generally perpendicular to panel 12 . A neck 72 of slot 70 is reduced in width to allow pin 66 to selectively engage (e.g., snap in or out) with block 54 , as block 54 swings about pin 64 between the operative and dislodged positions. Pin 64 thus forms a second member that fastens guide member 24 to panel 12 such that guide member 24 stays with panel 12 even after it has moved to the dislodged position.
Disengagement between pin 64 and slot 70 occurs when an impact force applied against and generally perpendicular to panel 12 , as indicated by arrow 62 , is reacted by a counter force that track 28 exerts against roller 58 in an opposite direction. The counter force being spaced apart from pin 64 produces a clockwise (as viewed in FIG. 9) torque on block 54 about pin 64 . The torque forces block 54 to rotate about pin 64 and away from pin 66 (thus separating therefrom) when the force applied along direction 62 is sufficient release pin 66 from slot 70 .
To return release mechanism 44 from its dislodged position to its operative position, panel 12 is moved back to its normal operating position adjacent track 28 , roller 58 is reinserted into track 28 , and pin 66 and block 54 are reconnected. To reconnect pin 66 and 54 , the two can be snapped back together or pin 66 can be lifted or lowered lengthwise back into slot 70 once slot 70 is realigned with the holes that receive pin 66 . The terms, “snap” and “snapped” refer to the engagement or disengagement of two elements, wherein at least one of the elements resiliently deforms as the two elements engage or disengage.
Although pins 64 and 66 are preferably non-frangible, in some cases it may be desirable to make pin 64 (and/or pin 66 ) frangible. Pin 64 when frangible could release block 54 from bracket 46 under a predetermined force that is sufficient to break pin 64 but not be so great as to significantly damage other parts of release mechanism 44 . Thus, a frangible pin 64 can serve as a sacrificial piece that is relatively inexpensive and easy to replace after panel 12 is dislodged. To render pin 64 frangible, pin 64 can be made of a relatively weak material or be sized to limit its strength.
To selectively disable the breakaway feature of release mechanism 44 , pin 66 is removed from slot 70 and the corresponding holes of bracket 46 , and reinserted through another set of holes 74 and 76 that are in bracket 46 and block 54 , respectively, as shown in FIG. 10 .
To allow a door panel to move in response to an impact from either direction (i.e., from inside to outside, as indicated by arrow 62 of FIG. 9, or from outside to inside, as indicated by an arrow 76 of FIG. 11 ), a release mechanism 44 ′ can be provided with a modified block 78 , as shown in FIG. 12 . Block 78 is similar to block 54 ; however, a slot 80 in block 78 replaces hole 68 of block 54 . Slots 70 and 80 are similar in that they both allow their respective pins 66 and 64 to selectively and engage and release block 78 . Sufficient force acting against a door panel in the direction of arrow 77 can force block 78 to swing about pin 66 and break away from pin 64 , or sufficient force acting in an opposite direction (direction 62 of FIG. 9) can force block 78 to swing about pin 64 and break away from pin 66 . Thus, release mechanism 44 ′ has two pivot points: pin 64 and 66 . Moreover, pin 64 in this embodiment forms a second member that is adapted for selective engagement with the guide member. Thus, both pins 64 and 66 are capable of pivotally mounting guide member 24 to panel 12 when breakaway or release occurs about the other pin, while at the same time being capable of themselves selectively disengaging from guide member 24 for an appropriately directed breakaway force. To provide one or more guide member 24 with sufficient clearance to swing to the position of FIG. 11, door panel 12 and/or the other door panels are provided with a notched out section 79 .
In some cases, pin 64 and slot 80 , and pin 66 and slot 70 may be sized differently to provide release mechanism 44 ′ with a breakaway threshold that is greater in one direction than the other. In other cases, the dimensions of pins 64 and 66 and their fit within their respective slots 80 and 70 may be identical and still provide a threshold differential or breakaway threshold that is greater in direction 77 than in direction 62 by virtue of track 28 being closer to pin 66 than to pin 64 , which provides a leverage advantage to a force acting in direction 62 (opposite to direction 77 ). To provide an equal breakaway threshold in both directions, the engagement between pin 64 in slot 80 may be made loser than the engagement between pin 66 and slot 70 to compensate for the threshold differential brought on by pins 64 and 66 being at an unequal distance away from track 28 .
Although pins 64 and 66 have been described as individual pins, the two pins can be joined or formed as a unitary U-shaped retainer 82 , as shown in FIGS. 13-15. Retainer 82 comprises a pin 84 and a pin 86 that are connected by a cross member 88 . Retainer 82 can be used in conjunction with a block 90 that is similar to blocks 54 and 78 . The distance between a hole 92 and a slot 94 is preferably the same as the distance between a hole 96 and hole 92 , with the layout of slot 94 and holes 92 and 96 corresponding to a matching pattern of three holes in a bracket similar to that of bracket 46 . Inserting retainer 82 in the position of FIG. 13 (i.e., pin 84 in hole 92 , and pin 86 in slot 94 ) provides a release mechanism that operates like release mechanism 44 of FIG. 9 . And inserting retainer 82 in the position of FIG. 14 (i.e., pin 84 in hole 92 , and pin 86 in hole 96 ) disables the breakaway feature to provide an operating mode similar to release mechanism 44 of FIG. 10. A hole 98 for a setscrew 100 is positioned so as not to interfere with hole 96 . Sleeve 102 , as shown in FIG. 15, extends over the shaft of the guide roller to reinforce the shaft and help establish a certain spacing between the roller and block 90 .
As a further illustration of the inventive release mechanism, an alternative embodiment including release mechanism 44 ″ is provided, as shown in FIGS. 16-18. Release mechanism 44 ″ includes a guide member 24 ′ whose shaft 56 ′ is pivotally coupled to a door panel 12 ′ by way of a pin 104 that that can be connected to panel 12 ′ directly or connected indirectly through a bracket 106 . With sufficient force acting in direction 62 , guide member 24 ′ pivots about pin 104 to disengage or separate from a releasable bracket 108 , which is attached to panel 12 ′ at a position between pivot pin 104 and the portion of guide member 24 ′ engaged with the track. In some embodiments, releasable bracket 108 is a snap-action device; however, bracket 108 is schematically illustrated to encompass any device that is adapted for selective engagement (FIGS. 16 and 18) and disengagement (FIG. 17) with guide member 24 ′. Releasable bracket 108 thus forms a first member adapted for selective engagement with the guide member 24 ′ in a similar sense to the way that pin 66 of the embodiment of FIG. 9 is adapted for selective engagement with guide member 24 . That is, the concept of adapted for selective engagement can encompass the situation where the guide member is yieldable relative to a generally rigid first member (as in slot 70 yielding relative to the generally rigid pin 66 in FIG. 9) and the situation where the guide member is generally rigid, and it is the first member that yields relative to the guide member (as in releasable bracket 108 yielding relative to generally rigid shaft 56 ′ of guide member 24 ′ in FIGS. 16 - 18 ). In all of the embodiments described so far, then, the guide member is pivotally mounted to the panel, and a first member is provided that is adapted for selective engagement with the guide member to selectively place the guide member in an operative position and a dislodged position, with the first member and guide member being separated in the dislodged position.
To allow door 10 to be held in a closed position without limiting the breakaway ability of a release mechanism, door 10 is provided with a latch mechanism 110 , as shown in FIGS. 1, 2 and 19 - 21 . Latch mechanism 110 includes a base 112 whose position is stationary and a traveling bar 114 , which is attached to panel 14 . A pin 116 rotatably couples an arm 118 to base 112 , so arm 118 that can swing over and thus capture traveling bar 114 to inhibit door 10 from opening, as shown in FIGS. 19 and 20. Even though arm 118 engaging bar 114 inhibits panel 14 from rising, door panel 14 can still be forcibly dislodged in direction 62 , because panel 14 (as it becomes dislodged) can move bar 114 from the restraint of arm 118 by moving arm 144 in direction 62 .
To release door 10 under normal, non-breakaway conditions, arm 118 can swing away from bar 114 and preferably swing over and onto a stationary bar 120 that extends from base 112 , as shown in FIGS. 1, 2 and 21 . To inhibit arm 118 from accidentally swinging off bars 114 or 120 , a distal end of each bar 114 and 120 can be provided with a hole to receive the shackle of a padlock 122 , whereby padlock 122 can hold arm 118 at either selected location: on bar 114 or 120 .
Although the invention is described with reference to a preferred embodiment, it should be appreciated by those skilled in the art that various modifications are well within the scope of the invention. Therefore, the scope of the invention is to be determined by reference to the claims that follow.
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A release mechanism for protecting a sectional door under impact allows one or more door panels to breakaway from its guide track without damaging the door. The release mechanism includes a snap-in pin that can be selectively repositioned to provide various operating modes. Examples of operating modes include unidirectional release, bi-directional release, and a disabled mode. In some cases, the breakaway threshold is greater in one direction than another. In the disabled mode, the release mechanism is not meant to release. Some embodiments include a door locking mechanism that still allows the release mechanism to operate.
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FIELD OF THE INVENTION
The present invention relates to battery charging systems.
BACKGROUND
With the increase in popularity of electric and hybrid vehicles that utilize rechargeable battery systems for at least a portion of their power source, the need for charging stations to recharge these battery systems is increasing. Although most battery systems can be recharged from a domestic wall socket, many support faster charging at higher voltages and currents which requires more expensive dedicated equipment with specialized connectors. Some systems may use 240 Volt AC or 500 Volt DC high-current to provide greatly accelerated charging.
BRIEF DESCRIPTION OF THE DRAWINGS
The present invention is illustrated by way of example, and not limitation, in the figures of the accompanying drawings and in which like reference numerals refer to similar elements and in which:
FIG. 1 illustrates an exemplary chart showing a how charging capacity demand changes over time for a public electric vehicle charging station;
FIG. 2 illustrates one embodiment of an electric vehicle charging station that provides increased charging capacity utilization and increased vehicle capacity;
FIG. 3 shows an exemplary system diagram for a control unit;
FIG. 4 illustrates an exemplary sequence of operations to manage the allocation of charging capacity to vehicles requiring charge in a charging station;
FIG. 5 illustrates an exemplary sequence of operations to determine the allocation of charging capacity to vehicles coupled to a charging station, and
FIG. 6 illustrates an exemplary sequence of operations to determine the charging requirement of vehicles coupled to a charging station; and
FIG. 7 provides an example of a table showing the relationship between charging priority and price paid.
DETAILED DESCRIPTION
In various embodiments disclosed herein, an electric vehicle charging station is described that utilizes a plurality of dynamically allocated charger units and charger points to provide a number of benefits including, without limitation, a) increasing the utilization and efficiency of the available charging capacity of the charging station, b) increasing the number of vehicles that may be using the charging station at any one time, c) providing more options (including dynamically determined options) to the operators of the vehicles using the charging station regarding charging time, cost, and other factors, and d) allowing for easier maintenance of the charging station, and so forth.
Depending on the needs of the vehicle operator and the current state-of-charge of the battery system, the power required to charge a vehicle may vary by more than an order of magnitude. For example, a battery system requiring a 30 minute charge may require 16 times the power of a similar battery system in a similar state-of-charge requiring an 8 hour charge. An example of the charging demand profile for an electric vehicle charging station is shown in FIG. 1 . While the charging station is easily able to accommodate the power requirements of several attached vehicles with longer required charging periods, the high power demand of 2 vehicles requiring a very short charging period during the mid-day time period causes the charging station to exceed its available charging capacity.
FIG. 2 illustrates one embodiment of an improved charging station 200 . A plurality of power sources 230 provide power to a plurality of charger units 210 that regulate the power and then deliver it via a power distribution network 220 to plurality of charger points 250 that are in turn coupled a plurality of vehicles requiring charge. The power source provides power to the charger units. The form of the power (e.g., AC or DC, low or high voltage, or other forms) delivered by the power source may vary depending on the specific needs of the local environment and the type and availability of external power for the system. Some charging stations may be coupled to a national or local grid. Others may be coupled to solar panels, wind turbines, self-contained generators (e.g., combustion engines), or other forms and combinations of energy supply. The power sources may be physically adjacent to the charger units, or they may be in one or more remote locations. The charger units convert energy from the power sources, using energy conversion techniques such as, but not limited to, DC to DC conversion, AC to DC conversion, DC to AC conversion, AC to AC conversion, current limiting and voltage regulation, as determined, at least in part, by the charging requirements of the vehicle that is using power from the charger unit and/or requirements of the vehicle operator (e.g., the vehicle driver, owner, custodian or other person available to specify such requirements). Power provided from the charger unit may vary over time as necessary to improve factors including, but not limited to, charger unit efficiency, charge time, battery life and charging cost to the vehicle operator.
One or more control units 240 , referred to collectively herein as “the control unit” manage the process of delivering power to the vehicles using the system. The control unit is coupled to the other components of the charging station using a control network 270 which may consist of a shared communication bus, point to point network, wireless network (e.g., Wi-Fi, Bluetooth, Cellular, etc.) or other form of communication mechanism or combination of communication mechanisms. The control unit may be physically co-located with the other components of the charging station, or remotely located (e.g., in a centralized data processing center that manages power delivery in multiple charging stations 200 . The control unit monitors system information from, but not limited to, the power sources, the charger units, the charger points, the vehicle and the vehicle operator to dynamically allocate charger units to charger points and to determine the various power delivery parameters for each vehicle using the system. The charger unit allocation and power delivery parameters may change over time (i.e., dynamically, during the charging interval) in response to changing system information.
FIG. 3 depicts an embodiment of a control unit that may be used to implement each or all of the control units of FIG. 2 . As shown, the control unit includes a processor 310 , memory 320 , and I/O block 330 coupled together with an interconnect bus. The control unit may include numerous other functional blocks in addition to or within the functional blocks shown, including a user interface to enable control unit programming, maintenance and system-level data collection. The control unit is capable of executing programmed instructions (e.g., stored within memory 320 ) to implement various sequences of operations as described herein
Referring again to FIG. 2 , the power distribution network 220 may be used to connect charger units to charger points as determined by the control unit. Depending on the charging requirements of a vehicle, more than one charger unit may be coupled to a single charger point if the power required by a vehicle exceeds the capacity of a single charger unit. Conversely, if the charging power required by multiple vehicles can be provided by a single charging unit, then multiple charger points may be coupled to a single charger unit. The mechanism for connecting a charger unit to a charger point in the power distribution network may include relays, solid state devices or any other mechanism for delivering electrical power from a power source to a load. Should one or more of the charger units become defective, the control unit may de-allocate and disconnect the charger unit(s) from any charger point(s) to allow the charger unit(s) to be safely replaced while the charging station is in operation. Although the overall capacity of the charging station is reduced by loss of a charger unit, the controller may dynamically re-allocate charger units to charger points so that the station may continue to charge all vehicles using the charging station, though at a potentially reduced rate. The charger point provides a mechanism to connect the vehicle to the charging station. The charger point may require the vehicle operator to physically plug a connector into the car, or it may automatically connect to the car using some predetermined standard mechanism. Associated with the charger point, but not necessarily physically coupled to it, is a UI device 260 that both provides information to and accepts input from the operator of the vehicle regarding the charging of the vehicle. While the UI device may be attached to the charger point, other devices, such as cell phones, operator interfaces or infotainment systems in the vehicle, or other devices, wirelessly or physically coupled to the control unit, may be used to provide information to and receive information from the control units in the charging station.
FIG. 4 illustrates an exemplary sequence of operations to manage the allocation of charging capacity to vehicles requiring charge in a charging station. The sequence begins at 410 , where, optionally, the available charging options are determined and presented to the operator of the vehicle. Such options include, but are not limited to, the charge time, the desired resulting state-of-charge after charging completes, and the cost options available. For example, an operator may be prompted to pay more to charge his/her vehicle in a shorter time or to ensure that the charge time is not extended if additional vehicles have coupled to the charging station and the charging demand now exceeds the available charging capacity of the station. Next, at 420 , information is optionally collected regarding operator requirements and options. One embodiment may include the storing of operator-specified preference information, either in a central location, or some other storage, possibly portable, such that the next time the operator charges the vehicle at a charging station having access to the preference information, charging options indicated by the preference information are automatically selected, thereby obviating operator entry of the same information in each charging-station visit reducing the time spent starting the charging process. At operation 430 , the charging system determines the actual charge to be delivered to each vehicle. A more detailed example of this operation is shown in FIG. 5 and described below. At 440 the charging system allocates charging units to charge points as necessary to meet the charging requirements from operation 430 . (It should be noted that the charging requirements from 430 are maximum requirements, as the vehicle may reduce its requirements over time). Operation 440 may result in one charger unit being coupled to one charger point, multiple charger units being coupled to a single charger point, a single charger unit being coupled to multiple charger points, or any combination of the foregoing. The charger units may also be allocated in such a matter as to improve the overall electrical efficiency (and therefore cost effectiveness) of the charging station. For example, if a charger unit operates at 75% efficiency when loaded at 100% (meaning that 25% of the energy is lost during the conversion) compared to 90% efficiency when loaded at 70%, the whole charging station can operate more economically if the charger units are allocated such that they are loaded at 70%, even if this means that more charger units are in operation. Continuing at operation 450 , the charger system adjusts the charge being delivered by the charger units to the charger points to meet the specific needs of the vehicles coupled to the charger points. For example, near the end of the charging process, the power delivered to a vehicle may be reduced or tapered. At 460 , the vehicle operator is optionally provided with information, including but not limited to, the actual power being delivered to his vehicle, which may be different, more or less, from the requested power due to changes in demands from other vehicles attached to the system. At operation 470 , the system evaluates if there have been any changes in charging demand. This could occur due to various events, including but not limited to, an operator decoupling a vehicle from the charging station, a vehicle being coupled to the charging station, a change in requirements from an operator such as a need for faster charging, or a reduction in charge demand from a specific vehicle because the battery system in the vehicle is reaching a fully charged state. If demand has changed, then the system loops back to 410 and optionally presents vehicle operators with a possibly new set of charging options. If there is no change in charging demand, then the system loops back to reevaluate if any change has occurred.
FIG. 5 illustrates an exemplary sequence of operations that may be executed by the controller to determine the allocation of charging capacity to vehicles coupled to a charging station. The sequence begins at operation 510 where the vehicle charging demand (VCD) is determined for each vehicle. The VCD is a rate of charge that is requested for a vehicle at a particular point in time. This process is shown in FIG. 6 and described in more detail below. Next, at 520 , the vehicle charging priority (VCP) is determined. This priority may be determined based on various factors such as the amount the operator is paying, participation in membership programs, the frequency with which the operator uses the charging station, or other factors. The control unit then uses the VCD and VCP and the system charging capacity at operation 530 to determine the vehicle charging rate (VCR) that will be delivered to the vehicle. The VCR is the actual maximum rate of charge that may be delivered to the vehicle. If the sum of all VCDs is less that the capacity of the charging station, then VCR may equal VCD. If not, then VCR may be adjusted based on VCP. Vehicles with higher VCP may receive disproportionally more power than those vehicles with lower VCP. Various techniques may be used to determine the disproportionality, such as determining the priority based on the price paid by the vehicle operator. One embodiment of the relationship between price and priority is shown in the table in FIG. 7 . Referring to FIG. 7 , if a vehicle operator pays $20 for a one hour 50 KW charge (as represented by 710 ), that operator's vehicle would have high priority and receive disproportionally more charge (and thus reach a charged state more quickly) than the vehicle of an operator who only pays $11 (as represented by 720 ) when the total charging demand from all vehicles exceeds the charging station capacity. Whereas if the charging demand did not exceed the charging station capacity, both of the vehicles would receive the same charging power despite the different price paid. In various other embodiments alternate or additional factors may be incorporated to determine disproportionality, including, without limitation, frequency of use of the charging station by an operator, the location, the time of day, and the time of year.
FIG. 6 illustrates one embodiment of a sequence of operations to determine the charging requirement of vehicles coupled to a charging station. Starting at operation 610 , it is determined if the charging station is receiving data from the vehicle (either through the charger point or via some other wireless mechanism) to allow the vehicle to request a specific VCD. If the charging station is receiving data from the vehicle, the sequence continues at 620 where it is determined if the vehicle is requesting a specific VCD. In such cases, processors or other devices in the vehicle may be self-determining the VCD based on the current battery system state-of-charge and other environmental factors (e.g., battery temperature, ambient temperature, etc.), and subsequently communicating the self-determined VCD to the charging station. If the vehicle is requesting a specific VCD (i.e., affirmative determination at 620 ), the sequence continues at operation 650 . Otherwise, if the vehicle has identified itself (decision 630 ), the sequence continues at operation 660 , if not the sequence goes to 640 . If the operator has identified the vehicle, then the sequence continues at 660 , if not the sequence proceeds to operation 670 . At operation 650 the VCD is obtained from the vehicle. At operation 660 the VCD is obtained by using stored charging reference data associated with the identified vehicle. This stored reference data, which may contain information regarding changes to the rate of charge with respect to time, battery system state-of-charge, desired charging time and other factors, may be obtained from the vehicle and/or battery system manufacturer, or accumulated from data collected while charging similar vehicles, or from some other source, or calculated based on various measured factors from the vehicle and battery system. At operation 670 the VCD is determined using charging reference data that is not associated with a specific vehicle. In such cases, as the specific vehicle is not known, the charging parameters may be more conservative, and may be based on various measured factors from the vehicle and battery system. Once the VCD has been determined, the sequence goes to 680 , where the VCD may be adjusted based on operator input, such as desired cost, charging time and other factors. Next at 690 , the electrical connection between the charger point and the vehicle is evaluated. Parameters that may be checked include, but are not limited to, the type of connection (different power levels may require different connections) and the quality of the connection (i.e. the power transfer efficiency, safety). As a result of the checks in 690 , the UI may present information to the operator such that appropriate adjustments may be made if necessary.
The charging station described in the foregoing increases the utilization of the available charging capacity of the charging station and the number of vehicles that may be using the charging station at any one time by dynamically allocating the charger units to charger points. Additionally, through use of a UI or similar device, it may provide more options to the operators of the vehicles using the charging station regarding charging time, cost, and other factors. The described charging station also allows for easier maintenance by, for example, permitting the replacement of portions of the charging station, such as the charger units, while the charging station is in operation as these portions may be deselected from use by the control unit.
In the foregoing description and in the accompanying drawings, specific terminology and drawing symbols have been set forth to provide a thorough understanding of the present invention. In some instances, the terminology and symbols may imply specific details that are not required to practice the invention. For example, the term “coupled” is used herein to express a direct connection as well as a connection through one or more intervening circuits or structures. Device or system “programming” may include, for example and without limitation, loading a control value into a register, one-time programmable-circuit (e.g., blowing fuses within a configuration circuit during device production) or other storage circuit within an integrated circuit device of the host system (or host device) and thereby control an operational aspect of the host system or establish a host system configuration. The terms “exemplary” and “embodiment” are used to express an example, not a preference or requirement. Signal paths that appear as single conductors may include multiple conductors and vice-versa, and components shown as being included within or forming part of other components may instead be disposed separately from such other components. With regard to flow diagrams and the like, the order of operations may be different from those shown and, where practical, depicted operations may be omitted and/or further operations added.
While the invention has been described with reference to specific embodiments thereof, it will be evident that various modifications and changes may be made thereto without departing from the broader spirit and scope. For example, features or aspects of any of the embodiments may be applied, at least where practicable, in combination with any other of the embodiments or in place of counterpart features or aspects thereof. Accordingly, the specification and drawings are to be regarded in an illustrative rather than a restrictive sense.
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A method of operating an electric vehicle charging system utilizing a plurality of charging units and charging points is disclosed. The method includes determining a rate of charge to be delivered to each vehicle and then allocating a respective portion of the total charging capacity of the charging station to each vehicle.
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RELATED APPLICATION(S)
This application is a divisional of U.S. application Ser. No. 10/789,317, filed Feb. 27, 2004 now U.S. Pat. No. 7,498,015. This application also may be related to U.S. application Ser. No. 10/616,147, filed Jul. 8, 2003 and entitled “Compositions and Methods for Forming a Semiconducting and/or Silicon-Containing Film, and Structures Formed Therefrom”, which is incorporated herein by reference in its entirety.
FIELD OF THE INVENTION
The present invention generally relates to the field of silane compositions. More specifically, embodiments of the present invention pertain to methods of forming cyclosilane compounds that are generally liquid at ambient temperatures, compositions including such cyclosilane compounds, methods for forming a semiconductor and/or semiconducting thin film from such cyclosilane compositions, and structures including such a film.
DISCUSSION OF THE BACKGROUND
Silane compounds are conveniently produced by reduction of chlorosilanes with Al-containing reducing agents (e.g., lithium aluminum hydride [LiAlH 4 ], or LAH). The silanes obtained after purification via recondensing or vacuum distillation oftentimes contain an appreciable amount of aluminum compounds. Without intending to be bound by any particular theory, it is believed that the aluminum compounds present in such recondensed or vacuum distilled silanes adversely affect the electrical properties of thin films made from such silanes (e.g., resistivity), and may adversely affect the physical properties of compositions including such silane(s) (e.g., the ability to form a uniform thin layer during spin coating).
Furthermore, there is a long-felt need for a “liquid silicon” composition. Such a composition would primarily comprise silicon, would be in the liquid phase at ambient temperatures (to facilitate handling, deposition and further processing), and would yield commercial quality semiconducting films upon subsequent heating (e.g., annealing or curing). Better yet, the “liquid silicon” composition would be patternable without conventional photolithography (i.e., without depositing conventional photoresist materials).
SUMMARY OF THE INVENTION
This invention is directed towards the preparation of hydrogenated Group IVA compounds (e.g., silanes) with reduced metal impurities (e.g., lithium, sodium, aluminum, etc.). The present invention is directed towards successfully removing aluminum impurities from silanes via a washing step (e.g., with deionized water, dilute acid or other aqueous or polar immiscible washing agent). This washing step may also reduce the amount of lithium, sodium and/or other metal-based impurities that are soluble in the polar phase. Thus, the invention concerns a method of making a hydrogenated Group IVA compound, comprising the steps of (i) reacting a reducible Group IVA compound of the formula A x X y with a metal hydride (e.g., a compound of the formula M 1 a M 2 b H c R d ) to form a metal-contaminated, hydrogenated Group IVA compound; and (ii) washing the metal-contaminated, hydrogenated Group IVA compound with a washing composition comprising an immiscible polar solvent to decontaminate the metal-contaminated, hydrogenated Group IVA compound (e.g., sufficiently to remove a substantial amount of the metal contaminants). In further aspects, the invention concerns a composition comprising one or more (cyclic) Group IVA compounds having less than a particular amount of certain impurities, a method of forming a semiconducting thin film from such a composition, and a thin film structure formed by such a method.
The present invention enables (1) the formation of silicon thin films with significantly reduced Al and/or alkali metal (e.g., Li) impurities, (2) improved stability of an ink containing the present silane composition, and (3) an improved silane deposition process. The present invention further advantageously provides thin film structures having improved physical and/or electrical properties (e.g., film roughness, conductivity, density, adhesion and/or carrier mobility), relative to structures made from an otherwise identical process without the washing step and/or containing a greater proportion of metal impurities. In addition, the properties of the thin films are generally more predictable than those of films produced from similarly prepared (cyclo)silanes, but that have not been washed according to the present invention. These and other advantages of the present invention will become readily apparent from the detailed description of preferred embodiments below.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Reference will now be made in detail to the preferred embodiments of the invention, examples of which are illustrated in the accompanying drawings. While the invention will be described in conjunction with the preferred embodiments, it will be understood that they are not intended to limit the invention to these embodiments. On the contrary, the invention is intended to cover alternatives, modifications and equivalents, which may be included within the spirit and scope of the invention as defined by the appended claims. Furthermore, in the following detailed description of the present invention, numerous specific details are set forth in order to provide a thorough understanding of the present invention. For example, the term “(cyclo)silane” as used herein generally refers to a compound that may contain one or more cyclic rings and that consists essentially of (1) a chain or framework of covalently bound silicon and/or germanium atoms, and (2) hydrogen and/or deuterium atoms bound thereto. In addition, the term “decontaminate” means to remove some, a measurable or significant amount, or substantially all of a contaminant from a composition, and the term “(hydrogenated) elemental material” refers to a material that consists essentially of atoms in an elemental state bound to each other (e.g., silicon and/or germanium in essentially an oxidation state of zero), but which may also include hydrogen atoms nonstoichiometrically, in less than a 1:1 atomic ratio (e.g., to cap or covalently bind so-called “dangling bonds” in the elemental material). However, it will be readily apparent to one skilled in the art that the present invention may be practiced without these specific details. In other instances, well-known methods, procedures, components, and circuits have not been described in detail so as not to unnecessarily obscure aspects of the present invention.
The present invention concerns a method of making hydrogenated Group IVA compounds (e.g., silanes), comprising the steps of (i) reacting a reducible Group IVA compound with a metal hydride to form a metal-contaminated, hydrogenated Group IVA compound (i.e., having one or more metal contaminants); and (ii) washing the metal-contaminated, hydrogenated Group IVA compound with a washing composition comprising an immiscible polar solvent to decontaminate the metal-contaminated, hydrogenated Group IVA compound.
Further aspects of the invention concern (1) a composition comprising one or more cyclic Group IVA compounds of the formula (AH z ) n , where n is from 3 to 12, each A is independently Si or Ge, each of the n instances of z is independently 1 or 2, and the composition contains less than 100 ppm of aluminum with respect to A atoms in the Group IVA compound; (2) an ink for printing a semiconductor and/or semiconducting thin film, including the inventive composition described herein and a solvent in which the composition is soluble; and (3) a method of making a semiconducting film, comprising the steps of depositing the present composition or ink on a substrate and curing the composition to form the semiconducting film. Curing is generally conducted under conditions sufficient to form a doped or undoped polysilane, polygermane or germanium-substituted polysilane having a molecular weight sufficiently high and/or a chemical composition sufficiently insoluble to resist subsequent treatment with processing solvents (e.g., in subsequent cleaning and/or development steps).
A still further aspect of the invention relates to a semiconducting thin film structure comprising an at least partially hydrogenated, at least partially amorphous Group IVA element, the Group IVA element comprising at least one of silicon and germanium, the semiconducting material having less than 100 ppm of aluminum with respect to Group IVA atoms in the thin film structure. In preferred embodiments, the structure may be formed by the present method as described herein.
The invention, in its various aspects, will be explained in greater detail below with regard to exemplary embodiments.
Exemplary Methods of Making a Hydrogenated Group IVA Compound
The present invention relates to a method of making hydrogenated Group IVA compounds (e.g., silanes), comprising the steps of (i) reacting one or more reducible (e.g., halogenated and/or alkoxylated) Group IVA compounds with a metal hydride to form a metal-contaminated, hydrogenated Group IVA compound; and (ii) washing the metal-contaminated, hydrogenated Group IVA compound with a washing composition comprising an immiscible polar solvent to decontaminate the metal-contaminated, hydrogenated Group IVA compound. In various embodiments, the halogenated and/or alkoxylated Group IVA compounds comprise or consist essentially of compound(s) of the formula A x X y , where each A is independently Si or Ge, each X is independently a halogen or an alkoxy group (e.g., a C 1 -C 6 alkoxy group, a C 1 -C 4 alkoxy-C 2 -C 6 alkyleneoxy group, a C 6 -C 12 aryloxy group or a C 6 -C 10 aryl-C 1 -C 4 alkyleneoxy group), x is from 3 to 12, and y is from x to (2x+2); the metal hydride comprises a compound of the formula M 1 a M 2 b H c R d , where M 1 and M 2 are independently first and second metals, each R in the metal hydride compound is independently a ligand bound to at least one of M 1 and M 2 by a covalent, ionic or coordination bond, at least one of a and b is at least 1, c is at least 1, and d is 0 or any integer up to one less than the number of ligand binding sites available on the (a+b) instances of M 1 and M 2 ; and/or the metal-contaminated Group IVA compound is washed with the washing composition sufficiently to remove a substantial amount of the metal contaminants. In certain implementations, x and y are selected such that the Group IVA compound(s) and/or hydrogenated Group IVA compound are liquid at ambient temperatures (e.g., from 15° C. to 30° C.). In other embodiments, M 1 is at least one alkali and/or alkaline earth metal and M 2 is at least one of the transition metals and/or a Group IIIA (or Group 13) element selected from the group consisting of boron, aluminum, gallium, and indium.
Where X in the compound of the formula A x X y is a C 1 -C 6 alkoxy group, a C 1 -C 4 alkoxy-C 2 -C 6 alkyleneoxy group, a C 6 -C 12 aryloxy group or a C 6 -C 10 aryl-C 1 -C 4 alkyleneoxy group, X may be methoxy, ethoxy, n-propoxy, isopropoxy, n-butoxy, s-butoxy, t-butoxy, n-hexyloxy, s-hexyloxy, t-hexyloxy (e.g., —OCH 2 CH 2 C[CH 3 ] 3 ), methoxyethoxy, ethoxyethoxy, propoxyethoxy, methoxypropoxy, ethoxypropoxy, butoxybutoxy, phenoxy (—OC 6 H 5 ), cresyl (—OC 6 H 4 CH 3 ), benzyloxy, etc. Alternatively, two X groups in the compound of the formula A x X y may form a C 2 -C 6 alkylenedioxy group, such as ethylenedioxy (—OCH 2 CH 2 O—) or propylenedioxy (—OCH 2 CH 2 CH 2 O—), or an ortho-arylenedioxy group, such as o-(—O—) 2 C 6 H 4 . However, in preferred embodiments, X is a halogen, such as chloride or bromide (more preferably Cl).
More specifically, the method relates to a metal hydride reduction of a perhalo(cyclo)silane of the formula Si x X y to form a corresponding (cyclo)silane of the formula Si x H y , where the (cyclo)silane is subsequently purified by washing (e.g., with an aqueous washing composition). The present washing step is believed to be novel and to be responsible for the observed reductions in metal impurities. In various embodiments, the washing composition comprises or consists essentially of a polar organic solvent that is immiscible with the silane composition (e.g. acetonitrile), deionized water, a saline solution (e.g., brine), or a dilute aqueous acid. In a preferred implementation, the washing composition consists essentially of deionized water.
However, in various alternative embodiments, the washing composition comprises dilute acid, which (i) has a pH of from 1 to less than 7 (and thus comprises a dilute aqueous acid), (ii) may further comprise a buffer (e.g., the composition comprises a buffered aqueous acid), and/or (iii) is selected from the group consisting of dilute aqueous HCl, dilute aqueous HBr, dilute aqueous HI, etc. Buffers, when employed, may include alkaline metal, alkaline earth and ammonium salts of the corresponding acid used in a dilute acid composition. For example, the buffered aqueous acid may comprise dilute aqueous acetic acid buffered with ammonium acetate and/or an alkali metal acetate salt. Buffers may also include conventional buffers such as conventional sodium and/or potassium phosphate, oxalate and/or tartrate salt buffers. Alkaline solutions (e.g., having a pH of >9) are generally avoided, as such solutions may initiate and/or promote oligomerization, polymerization and/or rearrangement of the (cyclo)silane.
The relative proportions of the contaminated hydrogenated Group IVA compound and the washing composition may be any that effectively remove metal contaminants from the hydrogenated Group IVA compound. For example, the washing composition and the hydrogenated Group IVA compound may be present in a volume ratio of from 10:1 to 1:10 (not including any relatively non-polar organic solvent or other component that may be present in or with the hydrogenated Group IVA compound), from 5:1 to 1:5, or from 3:1 to 1:1.
The present method may further comprise the step of purifying the (metal-contaminated) hydrogenated Group IVA compound, either before or after the washing step. Such purifying typically comprises distilling the hydrogenated Group IVA compound, optionally under reduced pressure (e.g., from 0.1 to 50 Torr) and/or at ambient temperature or higher (e.g., from about 15° C. to about 90° C., or from about 20° C. to about 60° C.). For example, typical conditions for distilling cyclo-Si 5 H 10 include a temperature of about 25° C. and a pressure of about 0.5 Torr.
Prior to the present washing step, the (cyclo)silane may include metal contaminants of up to 0.1-0.2 atom % or more (with respect to silicon and/or germanium atoms in the (cyclo)silane), particularly where the (cyclo)silane is synthesized using aluminum compounds (see the discussion below). However, after the present washing step, the metal contaminant(s) are typically present in a concentration or amount of less than 100 parts per million Group IVA atoms in the (cyclo)silane, preferably less than 10 parts per million Group IVA atoms, and more preferably less than 1 part per million Group IVA atoms. Thus the present washing step is capable of reducing metal contamination (and particularly aluminum contamination) in the hydrogenated Group IVA compound by 2, 3, 4, or more orders of magnitude.
In one example, after distillation or recondensation from a hydro-dehalogenation reaction mixture, the (cyclo)silane or (cyclo)silane mixture is washed with deionized water of pH=7 for a length of time of from about 1 to about 5 minutes. The volume ratio of deionized water to silane(s) is from about 5:1 to about 1:2. After separation of the silane phase and drying over molecular sieves (4 Å) for a length of time of from about 0.1 minutes to about 1 hour, the (cyclo)silane phase is further applied as an ink onto a substrate. The Al content was measured. Compared to a film obtained from an otherwise essentially identical, but unwashed, (cyclo)silane batch, the Al content decreased by about 4 orders of magnitude (from about 0.1 at. % to about 100 ppb), as determined by secondary ion mass spectroscopy (SIMS).
In a further aspect, the method further comprises the step of drying the hydrogenated Group IVA compound, after the washing step. Typically, drying comprises contacting the hydrogenated Group IVA compound with a drying agent or desiccant, such as molecular sieves, anhydrous sodium or magnesium sulfate, anhydrous silica, etc., or exposing the hydrogenated Group IVA compound to a drying agent or desiccant, such as CaCl 2 , CaSO 4 or perhaps even P 2 O 5 that is physically separated from the hydrogenated Group IVA compound (for example by placing the drying agent in one section of a two-walled flask or container and the hydrogenated Group IVA compound in the other section, then sealing the flask or container and optionally purging the atmosphere to put the drying agent and hydrogenated Group IVA compound under a vacuum or an inert atmosphere).
The compound of the formula A x X y may be any straight-chain, branched, cyclic or polycyclic silane, germane, germasilane or silagermane useful for making hydrogenated silanes for thin semiconductor films. However, in preferred embodiments, the compound of the formula A x X y comprises a cyclic or polycyclic perhalosilane or perhalogermasilane. Thus, the resulting (cyclo)silane preferably comprises a cyclic Group IVA compound of the formula (AH z ) n , where n is from 3 to 12, and each of the n instances of z is independently 1 or 2, and in one embodiment, A is Si, n is from 4 to 8, and z is 2. Thus, the perhalosilane may be selected such that it yields such a cyclosilane (or mixture of such cyclosilanes) upon hydro-dehalogenation. In one implementation, the (cyclo)silane comprises a mixture of compounds of the formula (AH z ) n , where the majority (i.e., >50 mol %) of the (cyclo)silane composition consists of (SiH 2 ) 5 , accompanied by smaller molar proportions (e.g., ≦20 mol % each) of (SiH 2 ) 6 , (SiH 2 ) 7 and/or (SiH 2 ) 8 . In various examples, the (cyclo)silane composition comprises >80 mol % (preferably >90 mol %) of (SiH 2 ) 5 , and from 0.1 to 10 mol % each (preferably from 0.5 to 5 mol %) of (SiH 2 ) 6 , (SiH 2 ) 7 and/or (SiH 2 ) 8 . Typically, small amounts (e.g., <10 mol %, preferably <5 mol %, more preferably <3 mol %) of n-silanes and/or iso-silanes of the formula Si n H n+2 are present in such a mixture, where n is from 4 to 10 in such n-silanes and iso-silanes. The (cyclo)silane composition may further contain one or more high molecular weight silanes having, e.g., 60 or more silicon atoms therein. Such higher molecular weight silanes, which may form in a greater amount or proportion the longer the present washing and/or drying steps are conducted, tend to increase the viscosity of the (cyclo)silane composition, thereby improving its properties for certain applications (e.g., inkjetting, spin coating, curing, etc.).
Of course, the present method also comprises a metal hydride reduction (or hydro-dehalogenation) of a reducible (cyclo)perhalosilane (e.g., of the formula A x X y ) to form the hydrogenated Group IVA compound (e.g., of the formula (AH z ) n ). Generally, the metal hydride is added to a solution of A x X y at a temperature of from −78° C. to about 200° C. (preferably from about −20° C. to about 100° C., more preferably from about −10° C. to about 30° C.), depending on the solvent and the reactivities of the A x X y compound(s) and the metal hydride, then the reaction mixture is stirred until the reaction is substantially complete. In various embodiments (except where the metal hydride is generated in situ using a catalytic amount of a metal hydride precursor), a solution of the metal hydride may be added to a solution of A x X y over a period of time of from 1 minute to 10 hours, 5 minutes to 4 hours, or 10 minutes to 2 hours, and/or at a rate of from 1 to 100 mmol of metal hydride/minute, 3 to 50 mmol/minute, or 5 to 25 mmol/minute. In one implementation (on a scale of about 10 grams of [cyclo]silane), a solution of metal hydride is added over about an hour at a rate of about 8-10 mmol/minute. The reaction may be monitored (e.g., by infrared or FT-IR spectroscopy, gas phase chromatography, 1 H or 29 Si NMR spectroscopy, etc.), and if necessary and/or desired, warmed (e.g., from ≦0° C. to ambient temperature, or from ambient temperature to 50-100° C., etc.) until the reaction is complete. This total reaction time may be from 10 minutes to 2 days, 1 to 24 hours, or 4 to 16 hours. The molar ratio of hydrogen atoms in the metal hydride to X groups (e.g., halogen atoms) in the (cyclo)silane can be from 5:1 to about 1:1, and is preferably about 2:1 (e.g., from about 1.9:1 to about 2.1:1).
Exemplary solvents for the metal hydride reduction reaction include alkanes (e.g., C 5 -C 12 branched or unbranched alkanes and cycloalkanes), fluorinated alkanes (e.g., C 3 -C 8 alkanes having from 1 to 2n+2 fluorine substituents and C 3 -C 6 cycloalkanes having from 1 to 2n fluorine substituents, where n is the number of carbon atoms), arenes (e.g., benzene), substituted arenes (e.g., N-methylpyrrole or C 6 -C 10 arenes having from 1 to 8 fluorine substituents and/or C 1 -C 4 alkyl and/or alkoxy substituents; preferably benzenes having from 1 to 6 fluorine, C 1 -C 2 alkyl and/or methoxy substituents), aliphatic ethers (e.g., ethers having two C 2 -C 6 branched or unbranched alkyl groups, or 1 methyl group and one C 4 -C 6 branched or unbranched alkyl group), cyclic ethers (e.g., tetrahydrofuran or dioxane), and glycol ethers (e.g., of the formula (CH 3 (CH 2 ) w )O((CH 2 ) x O) y (CH 2 ) z CH 3 ), where x is independently 2-4 [preferably 2], y is 1-4 [preferably 1 or 2], and w and z are independently 0 to 3 [preferably 0]). The solvent selected for dissolving the perhalo(cyclo)silane compound(s) may be the same as or different from the solvent selected for dissolving the metal hydride. A preferred solvent for dissolving the perhalo(cyclo)silane compound(s) is cyclohexane, and a preferred solvent for dissolving the metal hydride is diethyl ether.
In the perhalo(cyclo)silane compound subject to metal hydride reduction where X is a halogen, X may be selected from the group consisting of Cl, Br and I, but is preferably Cl. Also, the perhalo(cyclo)silane compound of the formula A x X y may comprise a mixture of perhalo(cyclo)silanes of the formula (AX z′ ) n′ , where n′ and z′ are as described above for n and z, but which are independent for each compound in the mixture. In one example, the perhalo(cyclo)silane comprises a mixture of compounds of the formula (SiX 2 ) n′ , where the predominant portion (i.e., >80 mol %) of the perhalo(cyclo)silane composition consists of (SiX 2 ) 5 , accompanied by a smaller molar proportion (e.g., from 0.5 to 10 mol %) of (SiX 2 ) 4 and, typically, an even smaller molar proportion (e.g., from 0 to <10 mol %) of (SiX 2 ) 6 . Thus, in one embodiment, A is Si, x is from 4 to 6, and y is from 8 to 12.
The metal hydride used to reduce the halogenated or alkoxylated (cyclo)silane compound may comprise a compound of the formula M 1 a M 2 b H c R d . In certain embodiments, d is 0, and the metal hydride comprises a compound of the formula M 1 a M 2 b H c ; or a is 0, and the metal hydride comprises a compound of the formula M 2 b H c R d . In some embodiments, M 1 may comprise an alkali or alkaline earth metal, M 2 comprises one or more members selected from the group consisting of transition metals and Group IIIA elements, and a and b are each an integer of at least one. In such embodiments, the alkali metal may be selected from the group consisting of lithium, sodium, potassium, rubidium and cesium (preferably lithium, sodium and potassium); the alkaline earth metal may be selected from the group consisting of beryllium, magnesium, calcium, strontium and barium (preferably magnesium and calcium); the transition metal may be selected from the group consisting of yttrium, lanthanum, titanium, zirconium, vanadium, niobium, tantalum, chromium, molybdenum, tungsten, manganese, rhenium, iron, ruthenium, osmium, cobalt, rhodium, iridium, nickel, palladium and platinum (preferably titanium, zirconium, niobium, chromium, molybdenum, tungsten, rhenium, ruthenium, osmium, rhodium, iridium, palladium and platinum); and the Group IIIA element may be selected from the group consisting of boron, aluminum, gallium and indium (preferably aluminum). In some embodiments, the Group IIIA element may include aluminum and boron (e.g., an aluminoborohydride).
Examples of suitable metal hydrides of the formula M 1 a M 2 b H c include lithium aluminum hydride, calcium aluminum hydride, and (possibly) sodium borohydride. Examples of suitable metal hydrides of the formula M 2 b H c R d include dialkylaluminum hydrides such as diisobutylaluminum hydride (DIBAL). In such compounds (i.e., in which d is at least 1), R may be an alkyl group (e.g., a straight-chain or branched C 1 -C 6 alkyl group), an alkoxy group (e.g., a straight-chain or branched C 1 -C 6 alkoxy group), an alkoxyalkylene group (e.g., a straight-chain or branched C 1 -C 4 alkyl-C 1 -C 6 alkylene group), an alkoxyalkyleneoxy group (e.g., a straight-chain or branched C 1 -C 4 alkoxy-C 1 -C 6 alkylene group), a cyano group, etc. Examples of suitable metal hydrides of the formula M 2 b H c include aluminum hydride, gallium hydride, and aluminum borohydride (AlB 3 H 12 ). A suitable metal hydride of the formula M 1 a M 2 b H c R d is sodium dihydrido-bis-(2-methoxyethoxy)aluminate. Thus, in various embodiments, (i) M 2 comprises a member selected from the group consisting of transition metals and Group IIIA elements (as described above), a is 0 or 1, d is at least 1, and R is an alkyl group, an alkoxy group, an alkoxyalkylene group, an alkoxyalkyleneoxy group or a cyano group (preferably M 2 comprises aluminum, R is a C 1 -C 6 alkyl group, and c and d are integers having a ratio of from 1:2 to 2:1); or (ii) a is 1 and M 1 comprises an alkali metal, each R is independently a C 1 -C 6 alkyl group, a C 1 -C 6 alkoxy group, a C 1 -C 4 alkyl-C 1 -C 6 alkylene group, a C 1 -C 4 alkoxy-C 1 -C 6 alkylene group or a C 1 -C 4 alkoxy-C 1 -C 6 alkyleneoxy group, and c and d are integers having a ratio of from 1:3 to 3:1.
Alternatively, the metal hydride may be generated or created in situ during catalytic hydro-dehalogenation using a transition metal catalyst. In such a case, the transition metal may be selected from those described above, and R may be selected from monodentate ligands (e.g., a trialkyl amine such as trimethyl or triethyl amine, a trialkyl phosphine such as trimethyl or triethyl phosphine, a triaryl phosphine such as triphenyl phosphine, CO, pyridine, CN, a halogen such as Cl, OH, an oxo group [═O], etc.), bidentate ligands (e.g., diethers such as dimethoxyethane, diamines such as 1,2-bis(dimethylamino)ethane or bipyridine, etc.), and polydentate ligands (such as cyclopentadienyl, pentamethylcyclopentadienyl, benzene, etc.). Typically, such catalytic hydro-dehalogenation are performed under a medium to high pressure of hydrogen gas (e.g., from a few atm to many tens of atm; e.g., from 3 to 100 atm, or from 5 to 50 atm), and at a temperature of from ambient temperature (e.g., from about 15° C. to about 30° C.) to several hundred degrees (e.g., up to 100° C., 150° C., or 200° C.).
The halogenated and/or alkoxylated (cyclo)silane compound or composition may be synthesized by reducing and oligomerizing a compound of the formula AR′ 2 X 2 (where R′ is, e.g., aryl [such as phenyl or tolyl] or alkyl [such as methyl, ethyl, propyl, isopropyl, n-butyl, s-butyl, t-butyl, cyclohexyl, etc.), followed by treating the reduced and oligomerized compound with a mixture of a Lewis acid and a hydrogen halide, such as AlCl 3 and HCl gas (e.g., when R′ is aryl) or SbX 5 -based systems (e.g., when R′ is alkyl), to form a corresponding Group IVA halide compound. However, a more preferred synthetic route comprises (a) reducing and oligomerizing a compound of the formula AR′ 2 X 2 , then (b) in one reaction vessel, first (i) treating the reduced and oligomerized compound of the formula A X′ R′ y′ with a mixture of a Lewis acid and a hydrogen halide to form a corresponding Group IVA halide compound, then (ii) reacting the Group IVA halide compound with a metal hydride to produce the hydrogenated Group IVA compound (e.g., of the formula (AH z ) n ). Alternatively, the reduced and oligomerized compound of the formula A X′ R′ y′ (e.g., perphenylpentasilane) may be reacted with HX (e.g., HBr) under high pressure (e.g., in a Parr vessel) without using any catalyst to form the Group IVA halide compound.
Thus, the present method may further comprise the step of reacting a compound of the formula A X′ R′ y′ (e.g., A x′ Ar y′ , where Ar is aryl as described above and x′ and y′ are as described above for x and y, respectively, but which may be the same as or different from x and y, respectively) with HX (in this case, where X is a halogen) and a Lewis acid compound of the formula M 3 p X q to form a perhalo(cyclo)silane (e.g., the compound of the formula A x X y ). In various embodiments, Ar is an aryl group which may be substituted with alkyl (e.g., straight-chain or branched C 1 -C 6 alkyl groups), alkoxy (e.g., straight-chain or branched C 1 -C 6 alkoxy groups), aryl (e.g., C 6 -C 10 aryl groups), aralkyl (where the aryl and alkyl constituents may be as described herein), halogen, dialkylamino (where the alkyl constituents may be as described herein) and/or nitro groups; M 3 comprises a member selected from the group consisting of transition metals and Group IIIA elements (as described above); p is 1 or 2; and/or q is any integer up to the number of ligand binding sites available on the p instances of M 3 . In preferred embodiments, x′ is from 3 to 12, preferably from 4 to 6; y′ is 2*x′; A is Si; Ar is phenyl; and/or X is Cl or Br, preferably Cl. In a preferred implementation, HX is HCl and the compound of the formula M 3 p X q is AlCl 3 .
In one implementation, the reaction between a compound of the formula A x′ Ar y′ , HX and a compound of the formula M 3 p X q to form the perhalo(cyclo)silane and the subsequent hydro-dehalogenation reaction are performed consecutively in a single reaction vessel. Thus, the present method may further comprise adding the metal hydride to the reaction mixture containing the perhalo(cyclo)silane compound(s) (i.e., the product(s) from the reaction between the compound of the formula A X′ R′ y′ HX and a compound of the formula M 3 p X q ), without isolating or purifying the perhalo(cyclo)silane compound(s) before the metal hydride addition.
The reaction to form the perhalo(cyclo)silane compound or composition is generally conducted under rigorously dry conditions. For example, the solvent(s) and reagents in solid or liquid phase are generally purified, degassed and dried (in accordance with conventional techniques) prior to use. Gas phase reagents (e.g., HX gas) are generally purchased in dry form, and techniques to preserve its dryness are generally employed when transferring the gas phase reagent(s) to the reaction vessel. Such gas phase reactants may be continuously added to the reaction vessel (e.g., by bubbling through the reaction mixture). The reaction to form the perhalo(cyclo)silane compound or composition may be conducted at a temperature of from about −78° C. to about 200° C., from about 0° C. to about 150° C., or from ambient temperature (e.g., from about 15° C. to about 30° C.) to about 100° C., until the reaction is complete. As for the hydro-dehalogenation reaction above, the reaction to form the perhalo(cyclo)silane may be monitored (e.g., by infrared or FT-IR spectroscopy, gas phase chromatography, 1 H or 13 C or 29 Si NMR spectroscopy, etc.) to determine completeness. In various embodiments, the reaction may be conducted for a length of time of from 1 to 48 hours, 2 to 24 hours, or 4 to 16 hours. On a scale involving about one-half of a mole of silicon atoms, the reaction was conducted for a length of time of from 5 to 8 hours.
Generally, the solvents suitable for dissolving the perhalo(cyclo)silane described above are suitable for the reaction to form the perhalo(cyclo)silane compound(s). Typically, a catalytic amount of Lewis acid is used in this reaction. For example, the Lewis acid may be present in a ratio of from 1 to 200 mmol (or from 3 to 100 mmol, or from 5 to 50 mmol) per mole of A atoms in the compound of the formula A x′ R′ y′ . Alternatively, the Lewis acid may be present in a ratio of from 0.25 to 100 mmol (or from 1 to 50 mmol, or from 2 to 30 mmol) per mole of R′ substituents or moieties in the compound of the formula A x′ R′ y′ .
A preferred method of synthesizing the compound of the formula A x′ R′ y′ (e.g., A x′ Ar y′ ) comprises reacting a compound of the formula A u R′ v X′ w with a reducing agent to form the compound of the formula A x′ R′ y′ . Typically, u is at least 1, v is at least 1, and w is any integer up (2u+2−v). In one implementation, A is Si, u is 1, v is 1 or 2, and w is (4−v). The reducing agent may be any reducing agent that effectively produces A x′ Ar y′ from A u Ar v X′ w , but preferably, the reducing agent comprises an alkali metal.
The reaction to form the compound of the formula A x′ R′ y′ may also be conducted at a temperature of from about −78° C. to about 200° C., from about −20° C. to about 150° C., or from about −5° C. to about 100° C., until the reaction is complete. In one embodiment, the starting material of the formula A u R′ v X′ w is added to the reaction mixture containing the reducing agent at a first, relatively low temperature (e.g., from about −10° C. to about 10° C.), then after the starting material addition is complete, the reaction temperature is raised to ambient temperature (e.g., from about 15° C. to about 30° C.) for a first period of time, and then (optionally) the reaction mixture is heated to a temperature of less than about 80° C. (e.g., the reflux temperature of a solvent having a boiling point of less than 80° C.) for a second period of time sufficient to substantially complete the reaction. As for the hydro-dehalogenation reaction above, the reaction to form the compound of the formula A x′ R′ y′ may be monitored (e.g., by infrared or FT-IR spectroscopy, gas phase chromatography, 1 H or 13 C or 29 Si NMR spectroscopy, or if the reducing agent is insoluble, by visually observing its disappearance, etc.) to determine completeness. In various embodiments, the first period of time may be from 15 minutes to 16 hours, 30 minutes to 12 hours, or 1 to 8 hours, the second period of time may be from 30 minutes to 48 hours, 1 to 24 hours, or 2 to 12 hours, and the total reaction time may be from 1 to 48 hours, 2 to 24 hours, or 4 to 16 hours. On a scale involving about one mole of silicon atoms, the reaction was conducted for a length of time of about 6-7 hours, and on about a 4 mole scale, for about 10 hours.
Any of the solvents described above for dissolving the perhalo(cyclo)silane or metal hydride are suitable for the coupling reaction (to form A x′ R′ y′ from A u R′ v X′ w ), except for those that may deprotonate in the presence of the reducing agent. Preferred solvents include alkanes (e.g., C 5 -C 12 branched or unbranched alkanes and cycloalkanes), arenes (e.g., benzene), substituted arenes (e.g., benzenes having from 1 to 3 C 1 -C 4 alkyl and/or alkoxy substituents; preferably benzenes having 1 or 2 C 1 -C 2 alkyl and/or methoxy substituents), aliphatic ethers (e.g., ethers having two C 2 -C 6 branched or unbranched alkyl groups, or 1 methyl group and one C 4 -C 6 branched or unbranched alkyl group), cyclic ethers (e.g., tetrahydrofuran or dioxane), and glycol ethers (e.g., of the formula (CH 3 (CH 2 ) w )O((CH 2 ) x O) y (CH 2 ) z CH 3 ), where x is independently 2-4 [preferably 2], y is 1-4 [preferably 1 or 2], and w and z are independently 0 to 3 [preferably 0]). A particularly preferred solvent for the coupling reaction is tetrahydrofuran (THF).
Generally, a slight molar excess of reducing agent is reacted with the starting material of the formula A u R′ v X′ w (e.g., from 1.0 to 1.1 moles, and preferably from 1.001 to 1.05 moles, of reducing agent per mole of X′ atoms in the starting material). After the reaction is complete, a small amount (e.g., from 0.1 to 100 ml, 0.5 to 50 ml, or 1 to 25 ml) of deionized and/or distilled water may be slowly and carefully added to the reaction mixture to quench the reaction. The resulting mixture may be poured into a relatively large amount (e.g., a volume of from 1 to 5 times the reaction mixture volume) of deionized and/or distilled water (preferably at least deionized water), and stirred for a period of time of from 15 minutes to 8 hours, 30 minutes to 6 hours, or 1 to 4 hours. The reaction mixture phases may be separated (e.g., by filtering if the reaction mixture includes a solid phase, or by decanting and/or use of a reparatory funnel if the reaction mixture includes more than one liquid phase), and the organic/silicon-containing phase may be washed with water and dried (e.g., under vacuum, and/or if the product of the formula A x′ R′ y′ has a sufficiently high melting point, by heating to a temperature significantly below its melting point).
In addition to the process described above, compounds of the formulas A x′ R′ y′ , A x′ Ar y′ , A x X y and/or (AH z ) n may be made by conventional methods, such as those described in, e.g., U.S. Pat. Nos. 4,554,180, 4,683,145, 4,820,788, 5,942,637 and 6,503,570, and in, e.g., Kumada, J. Organomet. Chem., 100 (1975) 127-138, Ishikawa et al., Chem. Commun., (1969) 567, Hengge et al., J. Organomet. Chem., 212 (1981) 155-161, Hengge et al., Z. Anorg. Allg. Chem., 459 (1979) 123-130, and Hengge et al., Monatshefte für Chem., 106 (1975) 503-512, the relevant portions of which are incorporated herein by reference. Furthermore, the methods disclosed in any one of these references may be modified as suggested and/or disclosed in another of these references. However, the preferred method comprises reducing and oligomerizing AR′X 3 and/or AR′ 2 X 2 (where R′ is, e.g., phenyl), followed by treating with a mixture of a Lewis acid and a hydrogen halide, such as AlCl 3 and HCl gas, to form a corresponding Group IVA halide compound, then reducing with a metal hydride (such as lithium aluminum hydride) to form a mixture of mainly c-(AH 2 ) x , where x is from 5 to 8, preferably 5 to 6.
Exemplary Compositions
In one aspect, the present invention relates to a composition for forming semiconductor and/or semiconducting thin films, particularly patterned semiconducting thin films, and more particularly patterned silicon thin films. The composition generally comprises (a) at least one cyclic Group IVA compound of the formula (AH x ) n , where n is from 3 to 12, each of the n instances of x is 1 or 2, and each A is independently Si or Ge, and (b) less than 100 ppm of aluminum, with respect to the total number of A atoms in the Group IVA compound. Preferably, the cyclic Group IVA compound(s) comprise cyclosilanes. Thus, the terms “cyclic Group IVA compound(s)” and “cyclosilane(s)” may be used somewhat interchangeably herein. In certain embodiments, the cyclosilane has the formula (AH 2 ) n , where n is from 5 to 8. In further preferred embodiments, the composition comprises less than 10 ppm (and more preferably, less than 1 ppm) of aluminum with respect to atoms of A in the Group IVA compound.
Examples of suitable cyclic Group IVA compounds can be found in U.S. Pat. Nos. 6,541,354, 6,527,847, 6,518,087, 6,514,801, 6,503,570, 5,942,637, 5,866,471 and 4,683,145, and in U.S. Patent Application Publication 2003/0045632, the relevant portions of each of which are incorporated herein by reference. These compounds include c-(SiH 2 ) 3 , c-(SiH 2 ) 4 , c-(SiH 2 ) 5 , c-(SiH 2 ) 6 , c-(SiH 2 ) 7 , c-(SiH 2 ) 8 , tetracyclo-(SiH) 4 , pentacyclo-(SiH) 6 , hexacyclo-(SiH) 8 , c-(SiH 2 ) 4 (GeH 2 ), c-(SiH 2 ) 5 (GeH 2 ), c-(SiH 2 ) 3 (GeH 2 ) 2 , c-(SiH 2 ) 4 (GeH 2 ) 2 , c-(SiH 2 ) 2 (GeH 2 ) 3 , c-(SiH 2 )(GeH 2 ) 4 , c-(GeH 2 ) 5 , and mixtures thereof.
Another aspect of the invention relates to the chemical makeup of the present composition. For example, at least 90 mol % (preferably at least 95 mol %) of the composition consists essentially of the cyclic Group IVA compound (which may, in turn consist of a mixture of such cyclic Group IVA compounds, as described above). In some examples, at least 98 mol % of the composition consists essentially of the cyclic Group IVA compound(s).
Exemplary Inks
In another aspect, the present invention concerns an ink for printing or otherwise forming a semiconductor and/or semiconducting thin film. The ink may comprise or consist essentially of the exemplary (cyclo)silane composition described above. Where the ink consists essentially of the (cyclo)silane, the (cyclo)silane may also function as a solvent for other components (such as binding agents, thickening agents, photosensitizers, semiconductor nanoparticles, etc.). Alternatively, the ink may include, for example, the exemplary (cyclo)silane composition described above and a solvent in which the composition is soluble. In such an embodiment, the (cyclo)silane compound(s) may be present in the ink in a percentage by volume of from 0.1 to 50 vol. %, from 0.5 to 30 vol. %, or from 1.0 to 20 vol. %.
In further embodiments, the solvent in the present ink comprises an aprotic solvent and/or an apolar solvent. In the context of the present invention, an “apolar” solvent is one that may have a gas-phase dipole moment of about 2 debyes or less, about 1 debye or less, or about 0.5 debye or less. In many implementations, an apolar solvent has a dipole moment of about 0 debyes, due to its molecular symmetry (e.g., carbon tetrachloride, tetrachloroethylene, benzene, p-xylene, dioxane) and/or highly covalent nature of the chemical bonds therein (e.g., mineral spirits, hexane, cyclohexane, toluene). In some embodiments, the present ink comprises a solvent having a boiling point of about or less than 250° C., preferably about or less than 200° C., and more preferably about or less than 150° C., at atmospheric pressure.
Exemplary solvents for the present ink composition include alkanes (e.g., C 5 -C 12 branched or unbranched alkanes and cycloalkanes, preferably C 6 -C 10 cycloalkanes such as cyclooctane), halogenated alkanes (e.g., C 1 -C 4 alkanes having from 1 to 2n+2 halogen substituents and C 3 -C 6 cycloalkanes having from 1 to 2n halogen substituents such as fluorine, chlorine and/or bromine, where n is the number of carbon atoms; preferably C 1 -C 2 alkanes having from 2 to 2n+2 fluorine and/or chlorine substituents), arenes (e.g., benzene), substituted arenes (e.g., N-methylpyrrole or C 6 -C 10 arenes having from 1 to 8 halogen substituents and/or C 1 -C 4 alkyl and/or alkoxy substituents; preferably benzenes having from 1 to 6 fluorine, chlorine, C 1 -C 2 alkyl and/or methoxy substituents), aliphatic ethers (e.g., ethers having two C 2 -C 6 branched or unbranched alkyl groups, or 1 methyl group and one C 4 -C 6 branched or unbranched alkyl group), cyclic ethers (e.g., tetrahydrofuran or dioxane), and glycol ethers (e.g., of the formula (CH 3 (CH 2 ) w )O((CH 2 ) x O) y (CH 2 ) z CH 3 ), where x is independently 2-4 [preferably 2], y is 1-4 [preferably 1 or 2], and w and z are independently 0 to 3 [preferably 0]). Cycloalkanes (notably cyclooctane) appear to provide the best results with respect to ink stability.
The present ink may further comprise a surfactant (e.g., a surface tension reducing agent, wetting agent, etc.), a binder and/or a thickening agent, although no such additives are required. In fact, it is advantageous for the ink to exclude such additional components, particularly where such additional components include sufficiently high molar proportions of elements such as carbon, oxygen, sulphur, nitrogen, halogens or heavy metals to adversely affect electrical properties of the resulting thin film. Thus, in one embodiment, the present ink includes a small or trace amount of one or more high molecular weight silanes (e.g., as described above), in an amount effective to improve the wetting characteristics of the ink. Such higher molecular weight silanes may be formed by the preferred method of making a hydrogenated (cyclo)silane. However, where they are present, each of these additional components may be present in trace amounts in the present ink composition. However, the surface tension reducing agent, which is conventional, may be present in an amount of from 0.01 wt. % to 1 wt. %, preferably 0.02 wt. % to 0.1 wt. % of the ink composition. In certain embodiments, the surface tension reducing agent may comprise a conventional hydrocarbon surfactant, a conventional fluorocarbon surfactant or a mixture thereof. The wetting agent is generally present in an amount of from 0.05 wt. % to 1 wt. %, preferably 0.1 wt. % to 0.5 wt. % of the ink composition. The surfactant may be present in an amount of from 0.01 wt. % to 1 wt. %, preferably 0.05 wt. % to 0.5 wt. % of the ink composition. The binder and/or thickening agent, each of which is conventional, may be present in an amount sufficient to provide the ink composition with predetermined flow properties at a given processing temperature. However, typical amounts of these components in the composition are from 0.01 wt. % to 10 wt. %, preferably 0.1 wt. % to 5 wt. %
Exemplary Methods of Forming a Semiconductor and/or Semiconducting Thin Film
The present invention further concerns a method of forming a semiconductor and/or semiconducting thin film from the present (cyclo)silane compound(s), composition and/or ink. This method may comprise the steps of depositing a layer of the (cyclo)silane composition compound(s), composition and/or ink on a substrate; and curing the compound(s), composition and/or ink to form the semiconductor film. As discussed above, in general, the composition comprises or consists essentially of the (cyclo)silane compound(s), and the ink comprises the composition and a solvent in which the cyclic Group IVA compound is soluble.
In this method, depositing may comprise spin coating, dip coating, spray coating, ink jetting, slit coating, meniscus coating, or microspotting the (cyclo)silane compound(s), composition or ink on the substrate. Also, curing may comprise oligomerizing and/or polymerizing the cyclic Group IVA (cyclosilane) compound. Oligomerizing and/or polymerizing the cyclosilane generally comprises (i) heating the composition to a temperature of at least about 100° C. (preferably at least about 200° C. or at least about 300° C. to transform the cyclosilane into a higher molecular weight oligomeric, polymeric or [hydrogenated] elemental material), (ii) irradiating the compound or composition, or (iii) both heating and irradiating, as described in (i) and (ii). When curing is performed at a relatively low temperature (e.g., from about 100° C. to about 200° C., preferably from about 100° C. to about 150° C.), it generally evaporates or removes the solvent (particularly when performed under vacuum), and may transform part or all of the cyclosilane into a higher molecular weight oligomeric or polymeric material. Thus, curing may comprise (i) a first heating phase at a first temperature to evaporate and/or remove any solvent, and (ii) a second heating phase at a second temperature higher than said first temperature to transform the cyclosilane into a polymeric or (hydrogenated) elemental material. Typically, curing times may vary from 10 seconds to 60 minutes (preferably 30 seconds to 30 minutes) depending on the applied temperature and the desired film characteristics (e.g., hydrogen content, impurity level, density or extent of densification, level or percentage of crystallinity, doping levels, doping profile, etc.). Furthermore, when an ink is deposited, curing may further comprise drying the ink before heating and/or irradiating the compound or composition.
When the method of making a film includes irradiating the (cyclo)silane compound(s) or composition, the method may further comprise patterning the semiconductor thin film. In one embodiment, patterning comprises selectively irradiating portions of the layer of (cyclo)silane compound(s), composition or ink with light having a wavelength and/or intensity sufficient to oligomerize, polymerize or otherwise reduce the solubility of the (cyclo)silane compound(s) in the irradiated portions, and subsequently removing non-irradiated portions of the layer with a suitable solvent to form the pattern (e.g., developing the layer). The substep of selectively irradiating the layer may comprise (i) positioning at least one of the substrate and a mask such that the portions of the composition that will form the patterned structures can be selectively irradiated, and the non-irradiated portions (i.e., corresponding to the areas of the layer to be removed) cannot be irradiated, then (ii) irradiating the layer with light (e.g., ultraviolet, visible or infrared light) through the mask. The mask, which is conventional, is generally one that absorbs light of a wavelength or wavelength range used for the irradiating substep. Preferred UV radiation sources include those with an emission at 254 nm (e.g., a conventional handheld UV-lamp, an Hg lamp, etc.), as are known in the art.
The curing step may comprise a “polysilane” formation phase or step, and an annealing phase or step. The term “polysilane” is used as a convenient notation for any polymer of silane, germane, or combination thereof. Conversion of the cyclic Group IVA compound(s) to form a doped or undoped polysilane, polygermane, poly(germa)silane or poly(sila)germane generally occurs by irradiation with an appropriate dose of an appropriate energy of radiation, or thermally at a temperature around or above 100° C. A conventional radical initiator, such as 2,2′-azobisisobutyronitrile (AIBN), 1,1′-azobiscyclohexanecarbonnitrile, dibenzoylperoxide, butyl lithium, silyl potassium or hexamethyldisilane (and others) may lower the temperature for polysilane formation to below 100° C. Other methods to catalyze the formation of polysilanes from the cyclic Group IVA compound(s) include adding known transition metal complexes such as cyclopentadienyl complexes of early transition metals such as Hf, Zr, Ti and V (and known derivatives thereof). The amount of radical initiator added can vary from 0.00001 mol % to 10 mol % with respect to the cyclic Group IVA compound(s). Polysilanes may also be formed by ring opening polymerization of cyclic silanes. Formation of the semiconductor film generally occurs at a temperature above 200° C., more preferably above 300° C., and most preferably from about 350° C. to about 400° C.
Preferred curing conditions for films formed from the present cyclic Group IVA compound(s), composition or ink include curing at a temperature of about 400° C. or less, in the presence of a reducing atmosphere such as an argon/hydrogen mixture. Such conditions are believed to remove hydrogen and carbon-containing species from the film effectively and/or at a suitable rate. However, in such a case, subsequent lower-temperature annealing of a silicon film formed from such cured compositions may dramatically improve the film's electrical characteristics. The lower-temperature annealing is generally conducted in a reducing atmosphere (preferably in an argon-hydrogen mixture, more preferably containing ≦10% H 2 by weight or moles, and in one implementation, about 5 wt. % H 2 ), at a temperature in the range of from 250° C. to 400° C., preferably from about 300° C. to about 350° C., for a length of time of from 10 minutes to 12 hours, preferably from about 30 minutes to about 10 hours, and in one implementation, about 8 hours.
After curing and/or annealing, the method may further comprise cleaning the substrate with the patterned semiconductor thin film thereon, for example to remove any uncured composition or ink. This step may comprise rinsing with or immersing the substrate in a solvent, draining the solvent from the substrate, and drying the substrate and patterned semiconductor thin film. Solvent rinsing or washing may include the same procedure(s) as are typically used in photoresist development and/or photoresist etching (e.g., rinsing, immersing, spraying, vapor condensation, etc.). Preferred solvents include solvents in which the unpolymerized cyclic Group IVA compounds have a high solubility, such as the hydrocarbon and ether solvents described above for the exemplary ink.
In preferred embodiments, the pattern comprises a two-dimensional array of lines having a width of from 100 nm to 100 μm, preferably from 0.5 μm to 50 μm, and more preferably from 1 μm to 20 μm. The lines may have an inter-line spacing of from 100 nm to 100 μm, preferably 200 nm to 50 μm, more preferably 500 nm to 10 μm. Furthermore, at least a subset of the lines may have a length of from 1 μm to 5000 μm, preferably 2 μm to 2000 μm, more preferably 5 μm to 1000 μm, and a thickness of from 0.001 μm to 1000 μm, preferably 0.01 μm to 500 μm, more preferably 0.05 μm to 250 μm. Furthermore, the lines may comprise a first set of parallel lines along a first axis, and a second set of parallel lines along a second axis perpendicular to the first axis. Although parallel and perpendicular lines may minimize adverse effects from adjacent lines and/or maximize the predictability of electromagnetic field effects from adjacent lines, the patterned lines may take any shape and/or take any course that can be designed and formed.
Exemplary Semiconducting Thin Film Structures
A further aspect of the invention relates to a semiconducting thin film structure comprising or consisting essentially of a partially hydrogenated, at least partially amorphous Group IVA element, the Group IVA element comprising at least one of silicon and germanium, the semiconducting material having less than 100 ppm (preferably less than 10 ppm, more preferably less than 1 ppm) of Group IIIA metal contaminants (other than intentionally added boron) relative to the Group IVA element. In many cases, the semiconducting thin film structure comprises a pattern of semiconducting material on a substrate. The semiconducting material in the present semiconducting thin film structure is preferably made from the present composition and/or according to the present method(s). The cyclic Group IVA compound(s) in the present composition may help improve the quality of the thin film interface to adjacent oxide, for example by improving planarization of the semiconductor thin film. Improved adherence to an underlying substrate may also be provided, possibly by increasing the surface area of the film that makes chemical and/or physical contact with the underlying substrate at or before the time of curing and/or annealing.
In the present thin film structure, the at least partially hydrogenated amorphous Group IVA element preferably comprises amorphous silicon. Also, the (partially) hydrogenated, amorphous Group IVA element may further comprise a dopant (e.g., B, P or As), which may be covalently bound to Group IVA atoms therein (see, e.g., copending and commonly assigned U.S. Ser. No. 10/616,147, filed on Jul. 8, 2003, the relevant portions of which are incorporated herein by reference). In such a case, the dopant concentration profile or gradient may be substantially uniform throughout the entire thickness of the semiconductor thin film.
In another embodiment, the cured thin film may have a controlled doping profile; for example, it may comprise multiple layers of differently doped silicon. In one embodiment, a bottom layer may comprise one of p-doped silicon (i.e., where the composition comprises a compound containing boron) or n-doped silicon (i.e., where the composition comprises a compound containing P or As), a second layer thereon may comprise the other of p-doped silicon or n-doped silicon, an optional third layer on the second layer that comprises silicon having the same dopant type (p-doped or n-doped) as the bottom layer, in which the dopant may be present in the same, a higher or a lower concentration than the bottom layer, an optional fourth layer on the third layer that comprises silicon having the same dopant type (p-doped or n-doped) as the second layer, in which the dopant may be present in the same, a higher or a lower concentration than the second layer, and so on. Alternatively, the cured thin film may comprise lightly doped silicon (i.e., where the composition comprises a compound containing B, P or As in an amount or percentage by weight or moles sufficient to provide, e.g., from 10 −10 to 10 −7 moles of dopant per mole of Group IVA element) and a layer or region of heavily doped silicon (e.g., where the composition comprises a compound containing B, P or As in an amount or percentage by weight or moles sufficient to provide, e.g., from 10 −7 to 10 −4 moles of dopant per mole of Group IVA element) of the same dopant type. Such a structure may further comprise (i) a layer or region of oppositely doped silicon above it, below it and/or adjacent to it, and/or (ii) a layer or region of very heavily doped silicon (e.g., where the composition comprises a compound containing B, P or As in an amount or percentage by weight or moles sufficient to provide, e.g., from 10 −4 to 10 −3 moles of dopant per mole of silicon) above it and/or adjacent to it.
In a further embodiment, the semiconducting thin film may comprise one or more layers in a thin film transistor (TFT) and/or capacitor (such as a MOS capacitor). In yet another embodiment, the semiconducting thin film may be used for a photovoltaic device. For instance, a photovoltaic device may be made by the above process, but with a film thickness of from 1 to 1000 microns, preferably 5 to 500 microns, whereas the preferred thickness for a TFT is from 10 to 500 nm, more preferably from 50 to 100 nm.
However, in a preferred embodiment, the present thin film structure comprises a patterned, two-dimensional array of lines, each line having a width of from 100 nm to 100 μm, more preferably from 0.5 μm to 50 μm, and even more preferably from 1 μm to 20 μm. The lines may have an inter-line spacing of from 100 nm to 100 μm, preferably from 0.5 μm to 50 μm, more preferably from 1 μm to 20 μm. The thin film pattern lines may also have a length of from 1 μm to 5000 μm, at least a subset of the lines preferably having a length of from 2 μm to 1000 μm, more preferably from 5 μm to 500 μm. The lines may have a thickness of from 0.001 μm to 1000 μm, preferably from 0.005 μm to 500 μm, more preferably from 0.05 μm to 100 μm.
In certain embodiments, the substrate may comprise a transparent glass or plastic display window, and the circuit, circuit element, integrated circuit or block thereof may comprise a thin film transistor (TFT) display element. Alternatively, the substrate may comprise a silicon wafer or metal substrate, and the circuit, circuit element, integrated circuit or block thereof may comprise a radio frequency identification circuit (e.g., a so-called RF ID tag or device).
EXAMPLES
Synthesis of Perphenylcyclosilanes
In a 3 L four neck round bottom flask fitted with an addition funnel, a reflux condenser, a thermocouple and an overhead stirrer, 18.3 g (2.64 mol) Li ribbon (Aldrich, 0.38 mm thick) cut into small pieces under argon are suspended in 1 L of dry THF (tetrahydrofuran). Under vigorous stirring, 333 g (1.32 mol) Ph 2 SiCl 2 (Aldrich) is added to this suspension at a rate that allows for complete addition after 60 to 80 minutes. The suspension is kept between −5° C. and 5° C. during addition. After addition is complete, the reaction solution is allowed to warm up to room temperature. Additional stirring for a minimum of 3 hrs, or until all lithium has reacted, produces a yellow to red colored suspension. The suspension is heated to reflux for 3 hrs. After cooling to room temperature, any remaining silyllithium compounds are destroyed by adding a small amount (2-10 mL) of deionized water. The resulting white suspension (which can be handled in ambient atmosphere) is poured onto 4 L of deionized water and stirred vigorously for 3 hours. The off white precipitate is filtered and washed with 5×200 mL of DI water followed by 5×200 mL of cyclohexane. The resulting colorless powder is dried under vacuum at 180° C. for 24 hours. The yield after drying is 200 g.
A thermogravimetric analysis of the powder indicated no mass loss when heated to 200° C. 1 H-NMR analysis showed that the powder is a mixture containing at least 4 different species. The relative amounts observed for each species may vary from batch to batch. Generally, the reaction products include 60-98 mol % (Ph 2 Si) 5 , 1-40 mol % (Ph 2 Si) 4 and 0.5-10 mol % for other species, including (Ph 2 Si) 6 . The components of the mixture may be separated by recrystallization from toluene or ethyl acetate, whereby both (Ph 2 Si) 5 and (Ph 2 Si) 4 have been isolated in >99% purity as determined by 1 H-NMR. The identity of both (Ph 2 Si) 5 and (Ph 2 Si) 4 have been verified by X-ray structure determination and melting point determination.
Larger Scale Synthesis of Perphenylcyclosilanes
In a 12 L four neck round bottom flask fitted with an addition funnel, a reflux condenser, a thermocouple and an overhead stirrer, 73.6 g (10.6 mol) Li ribbon (Aldrich, 0.38 mm thick) cut into small pieces under argon, is suspended in 4 L of dry THF (tetrahydrofuran). Under vigorous stirring, 1.338 kg (5.284 mol) Ph 2 SiCl 2 (Aldrich) is added to the suspension at a rate that allows for complete addition after 210 minutes. The suspension is kept between −5° C. and 5° C. during addition. After addition is complete, the reaction solution is allowed to warm up to room temperature. Additional stirring for a minimum of 3 hrs, or until all lithium has reacted, produces a yellow to red colored suspension. The suspension is heated to reflux for 7 hrs. After cooling to room temperature, any remaining silyllithium compounds are destroyed by adding a small amount (10-20 mL) of deionized water. The resulting white suspension (which can be handled in ambient atmosphere) is poured into 20 L of deionized water and stirred vigorously for 3 hours. The off white precipitate is filtered and washed with 3×1000 mL of DI water followed by 3×500 mL of cyclohexane. The resulting colorless powder is dried under vacuum at 170° C. for 24 hours. The yield after drying is 760 g.
A thermogravimetric analysis of the powder indicated no mass loss when heated to 200° C. 1 H-NMR analysis showed that the powder is a mixture containing at least 4 different species (see Table 1). In one example, the mixture contained 72 mol % (Ph 2 Si) 5 , 25 mol % (Ph 2 Si) 4 , and 3 mol % of other species, including (Ph 2 Si) 6 . Data from other examples are shown in Table 1. The mixture may be separated by recrystallization from toluene or ethyl acetate, whereby (Ph 2 Si) 5 has been isolated in >95% purity as determined by 1 H-NMR. The identities of both (Ph 2 Si) 5 and (Ph 2 Si) 4 have been verified by melting point determination.
TABLE 1
Other
Phenylsilane
Yield
species
(%, based on
Amount
[Ph 2 Si] 5
[Ph 2 Si] 4
including [Ph 2 Si] 6
[Ph 2 Si] x ,
Example
(g)
(%)
(%)
(%)
x = 4,5)
1
142
70
27
4
76
2
188
64
32
4
78
3
118
90
5
5
71
4
203
90
5
5
85
5
200
71
24
5
83
6
197
70
26
5
82
7
207
86
8
6
86
8
99
85
9
6
82
9
204
85
9
6
85
10
203
92
3
5
85
11
203
84
7
9
84
12
760
73
22
5
79
Synthesis of Cyclosilanes
In a 3 L 3-neck flask equipped with a reflux condenser and a gas dispersion tube, 100 g of a perphenylcyclosilane mixture obtained as described above and 3 g freshly sublimed AlCl 3 are suspended in 1 L of dry cyclohexane. Under vigorous stirring, dry HCl gas is bubbled through this suspension at ambient temperature until an almost colorless to yellow solution is obtained. Under continuous HCl addition, the solution is stirred for another 5-8 hrs or until all phenyl groups have been replaced by chlorine as indicated by 1 H-NMR, 29 Si-NMR and FT-IR. 400 mL of a 1M ethereal solution of LiAlH 4 (Aldrich) is added under vigorous stirring to the perchlorocyclosilane solution at 0° C. After 1 hour, the addition is complete, and the resulting suspension is further stirred at room temperature for another 15 hrs. Two phases are formed upon removing 800 ml solvent under reduced pressure. The lower phase containing precipitated byproduct is removed with a separatory funnel to yield about 125 ml of a clear solution. The reaction product is distilled under reduced pressure (0.5 Ton, 25° C.) to afford 9 ml clear colorless liquid.
1 H-NMR, 29 Si-NMR, GC/MS, GPC/UV and GPC/RI analysis of the liquid confirm that a mixture of (cyclo)silanes has been formed with cyclopentasilane as the main component (between 75 and 99 mol %). Cyclohexasilane can be identified as a second component (between 0.5 and 10 mol %). Other silane species are formed in amounts between 0 and 6 mol %, as well as aromatic and aliphatic byproducts. Table 2 below lists product distribution data in wt. % (as determined by GC/MS) from a number of examples of cyclosilane synthesis performed according to this description. The numbers may not add up to 100% in all cases due to rounding.
TABLE 2
[H 2 Si] x
Si n H 2n+2
Si n H 2n−x
Amount
[H 2 Si] 5
[H 2 Si] 6
x > 6
4 ≦ n ≦ 8
n > 4, x > 0
Organics
Example
(g)
(%)
(%)
(%)
(%)
(%)
(%)
13
3.0
78.8
8.6
0.3
5.0
0.2
7.2
14
6.0
88.3
4.7
0.0
1.4
0.2
5.3
15
4.0
91.1
5.8
0.0
1.3
0.0
5.3
16
1.9
90.4
7.0
0.3
0.8
0.7
0.9
17
7.9
91.4
7.2
0.2
0.5
0.0
0.7
18
3.8
83.8
10.0
0.5
1.3
0.2
4.2
19
2.3
99.4
0.6
0.0
0.0
0.0
0.0
20
7.2
92.1
5.2
0.2
0.7
0.9
0.9
21
7.3
85.5
9.7
1.0
1.1
0.5
2.2
22
9.5
92.3
6.4
0.1
0.7
0.2
0.3
Water Wash
1 mL of a cyclosilane mixture as described above was added to an amber vial containing 2 ml degassed, deionized (DI) water. The two phases were mixed vigorously and allowed to sit for 1 min. The upper phase (which contained the cyclosilane) was then transferred to another vial, dried over 4 Å molecular sieves and filtered through a 0.2 μm membrane to obtain a clear liquid.
Treating the cyclosilane mixture with water after distillation of the raw material effects a substantial reduction of the amount of Al in the silane and substantially removes Al contamination in the Si film after spin coating. The amount of Al in the silane mixture before treating with water may be as high as 2%, depending on the nature and amount of Al byproduct (following the reduction of the perchlorocyclosilane mixture and the distillation procedure used to purify the reduced cyclosilane mixture). Regardless of the absolute amount of Al before contact with water, water washing and the subsequent separation of the silane phase from the water phase that now contains the Al component results in a silane film after spin coating in which the Al content is reduced to less than 100 ppm, preferably less than 10 ppm and more preferably less than 1 ppm. The treatment with water may also be carried out with slightly acidified water (e.g., water containing buffered acetic acid to keep the pH below 7). Exposure of the silane mixture to alkaline conditions should be avoided as it may lead to uncontrolled Si—Si bond scission and polymerization. Minimal chemical effects on the silane composition may be achieved when aqueous washing is carried out (preferably with neutral or DI water). It has been found that continued or longer exposure of the cyclosilane mixture to water may lead to isomerization of some silanes to different silanes, including higher molecular weight silanes. This effect may be advantageously used to adjust the volatility and/or viscosity of the silane composition in an ink before deposition. For example, viscosity, surface tension and wetting behavior of the resulting silane composition/film may be adjusted in this way. Contact with water can occur by either adding the silane mixture to water or adding the water to the silane mixture. The ratio of water to silane mixture is in the range of 10:1 to 1:10, more preferably between 5:1 and 1:5, and even more preferably it is about 2:1. The silane mixture after separation from the aqueous phase is further dried using standard drying methods, such as contacting with molecular sieves. Preferably, the molecular sieves comprise beads of the 4 Å type (e.g., commercially available from Aldrich Chemical Co.). After filtering, as the cyclosilane is generally temperature and light sensitive, so it is stored at low temperatures, preferably at or below room temperature and with light and UV protection (e.g., storing in a darkened vial or wrapping with aluminum foil) to further avoid any unwanted isomerization or generation of higher molecular weight components.
CONCLUSION/SUMMARY
Thus, the present invention provides a method for making a (cyclo)silane, a silane composition having reduced metal impurities, an ink including the silane composition, and a method for making semiconductor structures and/or semiconducting thin films. By washing the (cyclo)silane with a polar-phase washing composition or agent, a substantial amount of certain metal impurities (e.g., aluminum and/or alkali metals, such as lithium or sodium) may be removed, thereby greatly improving the electrical properties of a thin film formed from a composition containing the (cyclo)silane.
The foregoing descriptions of specific embodiments of the present invention have been presented for purposes of illustration and description. They are not intended to be exhaustive or to limit the invention to the precise forms disclosed, and obviously many modifications and variations are possible in light of the above teaching. The embodiments were chosen and described in order to best explain the principles of the invention and its practical application, to thereby enable others skilled in the art to best utilize the invention and various embodiments with various modifications as are suited to the particular use contemplated. It is intended that the scope of the invention be defined by the Claims appended hereto and their equivalents.
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A method of making hydrogenated Group IVA compounds having reduced metal-based impurities, compositions and inks including such Group IVA compounds, and methods for forming a semiconductor thin film. Thin semiconducting films prepared according to the present invention generally exhibit improved conductivity, film morphology and/or carrier mobility relative to an otherwise identical structure made by an identical process, but without the washing step. In addition, the properties of the present thin film are generally more predictable than those of films produced from similarly prepared (cyclo)silanes that have not been washed according to the present invention. The present invention advantageously provides semiconducting thin film structures having qualities suitable for use in electronics applications, such as display devices or RF ID tags, while enabling high-throughput manufacturing processes that form such thin films in seconds or minutes, rather than hours or days as with conventional photolithographic processes.
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BACKGROUND OF THE INVENTION
This invention relates to novel peptides and more particularly to unique peptides having from 6 to 8 amino acid residues which are useful as inhibitors of myristoylating enzymes.
Fatty acid acylation of specific eukaryotic proteins is a well established process which can conveniently be divided into two categories. On the one hand, palmitate (C 16 ) is linked to membrane proteins via ester or thioester linkage post-translationally, probably in the Golgi apparatus.
On the other hand, it is known that myristate (C 14 ) becomes covalently bound to soluble and membrane proteins via amide linkage early in the protein biosynthetic pathway. In the N-myristoylated proteins, amino-terminal glycine residues are known to be the site of acylation. See Aitkin et al., FEBS Lett. 150, 314-318 (1982); Schultz et al., Science 227, 427-429 (1985); Carr et al., Proc. Natl. Acad. Sci. USA 79, 6128-6131 (1982); Ozols et al., J. Biol. Chem. 259, 13349-13354 (1984); and Henderson et al., Proc. Natl. Acad. Sci. USA 80, 339-343 (1983).
The function of protein N-myristoylation is only beginning to be understood. Four of the known N-myristoyl proteins --p60 src , cyclic AMP-dependent protein kinase catalytic subunit, the calcineurin B-subunit, and the Murine Leukemia Virus oncogenic gag-abl fusion protein--are either protein kinases or a regulator of a phosphoprotein phosphatase (calcineurin) which modulate cellular metabolic processes. For p60 v-src , it has been shown that myristoylation is required for membrane association and expression of this protein's cell transforming potential. See Cross et al., Molec. Cell. Biol. 4, 1834-1842 (1984); Kamps et al., Proc. Natl. Acad. Sci. USA 82, 4625-4628 (1985).
The development of relatively short synthetic peptides which can be conveniently made by synthetic peptide synthesis would be highly desirable for identifying and in studying the regulation of enzyme action in fatty acid acylation. Such peptides could serve as synthetic substrates for the myristoylating enzyme in yeasts and mammalian cells. They could also serve as highly specific competitive inhibitors of the naturally-occurring substrates. Novel synthetic peptides which thus serve as substrates of myristoylating enzymes are disclosed in copending application Ser. No. 894,235, filed concurrently herewith. A preferred example of such substrates is the octapeptide
Gly-Asn-Ala-Ala-Ala-Ala-Arg-Arg.
The myristoylation reaction can be represented as follows: ##STR2##
BRIEF DESCRIPTION OF THE INVENTION
In accordance with the present invention, novel peptide inhibitors of myristoylating enzymes are provided which have an amino acid sequence selected from the group consisting of the following sequences or a physiologically acceptable amide or salt derivative thereof; ##STR3## wherein R=Leu, Phe, Tyr or Val.
Illustrative amide derivatives of these peptides are the carboxyamides. Illustrative salt derivatives are the HCl salts.
DETAILED DESCRIPTION OF THE INVENTION
The novel peptides of this invention can be made by appropriate adaptation of conventional methods for peptide synthesis. Thus, the peptide chain can be prepared by a series of coupling reactions in which the constituent amino acids are added to the growing peptide chain in the desired sequence. The use of various N-protecting groups, e.g., the carbobenzyloxy group or the t-butyloxycarbonyl group (BOC), various coupling reagents, e.g., dicyclohexylcarbodiimide or carbonyldimidazole, various active esters, e.g., esters of N-hydroxypthalimide or N-hydroxy-succinimide, and various cleavage reagents, e.g., trifluoracetic acid, HCL in dioxane, boron tris-(trifluoracetate) and cyanogen bromide, and reaction in solution with isolation and purification of intermediates is well-known classical peptide methodology.
Preferably, the peptides of this invention are prepared by the well-known Merrifield solid support method. See Merrifield, J. Amer. Chem. Soc. 85, 2149-54 (1963) and Science 150, 178-85 (1965). This procedure, though using many of the same chemical reactions and blocking groups of classical peptide synthesis, provides a growing peptide chain anchored by its carboxyl terminus to a solid support, usually cross-linked polystyrene or styrenedivinylbenzene copolymer. This method conveniently simplifies the number of procedural manipulations since removal of the excess reagents at each step is effected simply by washing of the polymer.
The general reaction sequence for conventional Merrifield peptide synthesis can be illustrated as follows: ##STR4## This step III follows cleavage of t-BOC such as by treatment, for example, with 25% trifluoracetic acid in methylene chloride and liberation of N-terminal amine by excess of triethylamine, thereby enabling it to react with the activated carboxyl of the next protected amino acid (R 2 ). A final step involves cleavage of the completed peptide from the PS resin such as by treatment, for example, with anhydrous HF in anisole.
Further background information on the established solid phase synthesis procedure can be had by reference to the treatise by Stewart and Young, "Solid Phase Peptide Synthesis," W. H. Freeman & Co., San Francisco, 1969, nad the review chapter by Merrifield in Advances in Enzymology 32, pp. 221-296, F. F. Nold, Ed., Interscience Publishers, New York, 1969; and Erickson and Merrifield, The Proteins, Vol. 2, p. 255 et seq. (ed. Neurath and Hill), Academic Press, New York, 1976.
The preferred peptide inhibitors of this invention are the octapeptides
Gly-Phe-Ala-Ala-Ala-Ala-Arg-Argp
and
Gly-Tyr-Ala-Ala-Ala-Ala-Arg-Arg.
Illustrative hexapeptide and heptapeptide inhibitors of this invention have one or two arginine deletions, respectively, at the carboxy termini of the above preferred octapeptides. The preferred peptides contain hydrophobic residues in amino acid position 2. They do not function as substrates for myristoylating enzymes but inhibit the myristoylation of the substrate Gly-Asn-Ala-Ala-Ala-Ala-Arg-Arg. Illustratively, the tyrosine-containing octapeptide has an apparent K i of 0.15 mM.
The octapeptide inhibitors containing the hydrophobic leucine or valine residues in amino acid position 2 function as substrates, but they have greatly increased apparent k m s of 0.3 mM and 0.7 mM and decreased maximum velocities relative to the substrate Gly-Asn-Ala-Ala-Ala-Ala-Arg-Arg. Both of these octapeptides inhibit the myristoylation of Gly-Asn-Ala-Ala-Ala-Ala-Arg-Arg. Illustratively, the leucine-containing octapeptide competitively inhibits with a K i of 0.06 mM.
Except for the substitution of the leucine, phenylalanine, tyrosine or valine in place of asparagine in amino acid position 2, the preferred octapeptides of this invention contain the six amino-terminal residues of bovine cardiac muscle cAMP-dependent protein kinase, followed by two arginine residues which replace the lysine residue in the native N-terminal heptapeptide sequence reported by Carr et al., Proc. Natl. Acad. Sci. USA 79, 6128-6131 (1982). The Carr heptapeptide was obtained as a blocked tryptic fragment upon proteolysis of a cyanogen bromide cleavage fragment of the native protein. Since the endogenous protein was already myristoylated, the peptide could not have been used as an in vitro acyl acceptor.
The synthetic octapeptide Gly-Asn-Ala-Ala-Ala-Ala-Arg-Arg was initially used to identify a unique enzymatic activity which transfers myristic acid to the amino terminal glycine of this and other peptides. The inhibitor activity of the novel peptides for the myristoylating enzyme is illustratively demonstrated with the N-myristoylglycylpeptide synthetase (N-myristoyl transferase) from Saccharomyces cerevisiae. The enzyme activity was determined in an in vitro assay which measures the transfer of [ 3 H]-myristic acid to the acceptor peptide. The transfer reaction is dependent on adenosine triphosphate (ATP) and coenzyme A (CoA). The enzymatic product was then identified by high performance liquid chromatography (HPLC) by co-elution with a chemically synthesized myristoyl peptide standard. To demonstrate that the enzymatic reaction product and the chemically synthesized standard were identical and contained myristate covalently bound to glycine, HPLC-purified standards and enzymatic products were both digested with pronase and analyzed by reverse phase HPLC. Both contained M-myristoyl glycine.
A protease-deficient strain of Saccharomyces cerevisiae, JR153 [Hemmings et al., Proc. Natl. Acad. Sci. USA 78, 435-439 (1981)], was used as a source of N-myristoylglycylpeptide synthetase to illustratively demonstrate the acylation of the octapeptides. This strain was shown to contain endogenous N-myristoyl proteins by labeling yeast with [ 3 H]myristic acid followed by lysis of cells and analysis of cellular proteins by sodium dodecylsulfate polyacrylamide gel electrophoresis (SDS-PAGE). N-[ 3 H]myristoyl glycine could be isolated from labeled endogenous acyl proteins by digestion with pronase followed by separation and analysis by reversed phase HPLC.
The following examples will illustrate the invention in greater detail although it will be understood that the invention is not limited to these specific examples.
EXAMPLE 1
All peptides herein were prepared essentially by the following method used for an illustrative peptide as a substrate of myristoylating enzymes:
A.
Synthesis of Gly-Asn-Ala-Ala-Ala-Ala-Arg-Arg-NH 2
The peptide was synthesized on p-methylbenzhydrylamine resin having a substitution of 0.35 mmol amino groups/gram of resin by the method of Merrifield [R. B. Merrifield, J. Am. Chem. Soc., 85, 2149-2154 (1963)] BOC-protected amino acids (4 equivalents) were used to form symmetrical anhydrides by mixing a 2:1 ratio of BOC-amino acid and dicyclohexylcarbodiimide in dichloromethane for 15 minutes. The solvent was evaporated in vacuo and the anhydride was redissolved in dimethylformamide and mixed with the resin and agitated for 1 hour. In the reaction of asparagine (and glutamine and arginine), an equimolar amount of hydroxybenzotriazole (based on amino acid) was included in the reaction mixture. The BOC-protecting groups were removed using 50% trifluoroacetic acid (TFA) in dichloromethane and the resin was neutralized with 10% diisopropylethylamine in dimethylformamide prior to coupling of amino acids.
The peptide was removed from the resin and deprotected using liquid HF/anisole (9:1, v/v) at 0 degrees for one hour. The crude peptide was extracted from the resin with 50% aqueous acetic acid and lyophilized.
B.
Purification
Crude peptide was dissolved in water and applied to a Waters μ-Bondapak C 18 column (19 mm×150 mm) and eluted with a gradient of 0-15% acetonitrile (0.05% TFA) in water (0.05% TFA) over 15 minutes at a flow rate of 9 ml/min. Fractions containing the product were combined and lyophilized, and the purity and identity of the peptide were ascertained by analytical HPLC and by amino acid analysis.
EXAMPLE 2
Labeling and extraction of yeast protein for electrophoretic analysis
Yeast (S. cerevisiae strain JR153, mating type alpha, trpl, prbl, prcl, pep4-3) was grown to an optical density at 660 nm of 1 to 3 in a rotary shaker at 30° C. in YPD medium (1% yeast extract, 2% Bactopeptone, 2% dextrose in distilled water). Fifteen ml aliquots of yeast culture were labeled for 30 minutes under identical conditions by addition of 1 mCi of [ 3 H]fatty acid in 10 μl of ethanol. At the end of the labeling period, the cultures were cooled for five minutes on ice and the cells were pelleted at 4° C. by centrifugation at 7600 x g for 10 minutes. Cells were then resuspended in 1 ml of 10 mM NaN 3 in 140 mM NaCl/10 mM phosphate, pH 7.2, transferred to 1.5 ml polypropylene conical centrifuge tubes, and collected by centrifugation at 4° C. as above. The supernatant was discarded, and the cells were suspended in 100 μl of 5 mM Tris, pH 7.4, 3 mM dithiothreitol, 1% SDS, 1 mM phenylmethylsulfonylfluoride, and broken with one cell volume equivalent of 0.5 mm glass beads, by six 30 second spurts of vigorous vortexing with cooling on ice between each vortexing. Debris was removed by centrifugation for 30 seconds at 8000 x g in a table top Eppendorf centrifuge. The supernatant was then alkylated in 125 μl of 8 mM Tris, pH 8.0, with 20 mM iodoacetamide for 1 hour at room temperature. Twenty microliter aliquots were analyzed by conventional SDS-PAGE and fluorography methodology essentially as described by Olson et al., J. Biol. Chem. 259, 5364-5367 (1984).
Analysis of the linkage [ 3 H]fatty acids to proteins
Twenty microliters of the reduced and alkylated [ 3 H]fatty acid labeled yeast protein was treated with 7 μl of freshly prepared 4M hydroxylamine/20 mM glycine, pH 10. After treatment for 4 hours at 23° C., samples were prepared for electrophoresis and fluorography as above.
To determine the hydroxylamine-stable linkage of [ 3 H]myristic acid to the 20,000 dalton acylprotein in JR153, the cultures were labeled as described above except that the cells were treated for 15 minutes prior to addition of fatty acid with 2 μg/ml cerulenin, a known inhibitor of yeast fatty acid synthesis which enhances the labeling of the specific acylproteins in JR153 several fold. Cellular protein was then prepared and separated by SDS 12% polyacrylamide gel electrophoresis as described above, running molecular weight prestained protein standards in gel lanes adjacent to sample lanes. After electrophoresis, 2 mm gel slices were cut from the undried gel sample lanes in the 20,000 dalton molecular weight region. Gel slices were rinsed rapidly with 0.5 ml of 10% methanol in water, then individually digested for 72 hours at 37° C. with 1 mg of Pronase E (Sigma, St. Louis, Mo.) in 1 ml of 50 mM ammonium bicarbonate, pH 7.9, with mixing on a Labquake mixer (Labindustries, Berkeley, Calif.). One microliter of toluene was added per digest to retard microbial growth. One mg of fresh Pronase E was added at 24 hours. Following digestion, the radioactivity present in aliquots of each digest was determined. The digest from the slice containing radioactivity was removed, the gel slice was rinsed once with 500 μl of 0.1% SDS, and the digest and rinse were combined and acidified to pH 1-2 with 40 μl of 6 N HCl. The acidified solution was extracted twice with 1.5 ml of chloroform-methanol (2:1, v/v). The combined organic phases were backwashed once with 1 ml of chloroformmethanol-0.01 N HCl (1:10:10, v/v/v), and the organic phase dried under a stream of nitrogen. The residue was redissolved in 50% methanol-50% HPLC buffer A (see below). Ninety-seven percent of the radioactivity present in the original protein digest was recovered after the extraction protocol. The sample was analyzed by reverse phase HPLC on a Walters μ-Bondapak C 18 column at a flow rate of 1 ml per min, using as buffer A, 0.1% trifluoroacetic acid/0.05% triethylamine in water, and as buffer B, 0.1% trifluoracetic acid in acetonitrile, eluting with a 1% per minute acetonitrile gradient. One minute fractions were collected, and radioactivity was determined by liquid scintillation counting. The myristoyl-[ 3 H]glycine standard was synthesized essentially as described by Towler and Glaser, Biochemistry 25, 878-884 (1986), and analyzed by HPLC as above.
Synthesis of fatty acyl peptide standards
The synthesis of acylpeptide standards was performed by reacting the radioactive symmetric myristic acid or palmitic acid anhydride with GlyAsnAlaAlaAlaAlaArgArg in pyridine. One hundred microcuries of [ 3 H]fatty acid was treated with 4 μl of the respective fatty acyl chloride, then suspended in 150 μl of pyridine containing 4.8 mg of the respective non-radioactive fatty acid. The reaction was allowed to proceed for 60 minutes at 23° C. Sixty-five microliters of this solution was then added to 400-500 μg of GlyAsnAlaAlaAlaAlaArgArg. The reaction was allowed to proceed overnight with mixing on a Labquake Mixer. The pyridine was then evaporated under vacuum, the residue extracted twice with 0.3 ml of petroleum ether, and redissolved in 400 μl of 50% methanol in water. The reaction products were then purified and analyzed by reverse phase HPLC as described above. The chemically synthesized standard and the enzymatic product were also both digested with Pronase E and analyzed by reverse phase HPLC as described above for the 20,000 dalton acylprotein, except that 200 μg of the protease was sufficient for complete digestion.
Preparation of yeast extract for the assay of N-myristoylglycylpeptide synthetase activity
Yeast cultures were grown as described above to O.D. 660 nm of 1 to 3. Cells from 40 ml of culture were collected by centrifugation at 4° C. at 7600 x g for 10 minutes. The supernatant was decanted, the cell pellet was resuspended by pipetting into 1 ml of cold 10 mM Tris, pH 7.4, transferred to a 1.5 ml conical polypropylene centrifuge tube, and the cells were then repelleted at 4° C. at 7600 x g for 10 minutes. Cells were resuspended in 400 μl of cold assay lysis buffer (10 mM Tris, pH 7.4, 1 mM dithiothreitol, 0.1 mM ethyleneglycol-bis(β-aminoethyl ether) N,N,N',N'-tetraacetic acid (EGTA), 10 μg/ml Aprotinin) by pipetting. Approximately 400 μl of 0.5 mm glass beads were added to the resuspended cells, and the cells were lysed by vortexing as described above for lysis of radioactively labeled cells. After allowing the beads to settle, the lysate was collected and cellular debris was removed by centrifugation at 4° C. at 1000 x g for 10 minutes. The supernatant was then centrifuged at 4° C. at 45,000 rpm for 30 minutes in a Beckman 75 Ti rotor. The supernatant was removed, and the crude membrane pellet was resuspended by pipetting into 400 μl of cold assay lysis buffer. Aliquots of the three cellular fractions were either assayed immediately or stored at -60° C. The activity associated with crude membranes was stable at -60° C. for at least 3 months. Protein was determined by the method of Peterson, Anal. Biochem. 83, 346-356 (1977).
Assay for N-myristoylglycylpeptide synthetase activity
[ 3 H]Fatty acyl CoA was synthesized enzymatically and added to the incubation as follows. The acyl CoA synthetase reaction consisted of (per one assay tube): 0.5 μCi of [ 3 H]myristic acid; 25 μl of 2X assay buffer (20 mM Tris, pH 7.4, 2 mM dithiothreitol, 10 mM MgCl 2 , 0.2 mM EGTA); 5 μl of 50 mM ATP in distilled water, adjusted to pH 7.0 with NaOH; μl of 20 mM lithium CoA in distilled water; 15 μl of lmU/μl of Pseudomonas acyl CoA synthetase (Sigma) in 50 mM N-2-hydroxyethylpiperazine-N'-2-ethane sulfonic acid, pH 7.3; 2.5 μl of distilled water. The reaction was allowed to proceed for 20 minutes at 30° C. Typically, 40% to 50% of the [ 3 H]fatty acid was converted to its CoA ester by this procedure as measured by determining the radioactivity remaining in the reaction after acidification with 6 N HCl to pH 2.0 and extraction 6 times with 5 volumes of heptane, a modification of the method of Hosaka et al., Meth. Enzymol. 71, 325-333 (1981). Fifty microliters of this reaction were added to tubes containing 40 μl of assay extraction buffer (see above) and 10 μl of 1 mM GlyAsnAlaAlaAlaAlaArgArg. The assay was initiated by the addition of 10 μl of yeast cell extract (typically 50 μg of protein) per tube, followed by incubation at 30° C. for 10 min. The assay was terminated by the addition of 110 μl of methanol and 10 μl of 100% trichloracetic acid (w/v) per tube, followed by cooling ten minutes on ice. Precipitated protein was removed by centrifugation at 8000 x g for 3 minutes in a tabletop Eppendorf centrifuge. (Under these conditions, 95% of synthetic [ 3 H]myristoylpeptide or [ 3 H]palmitoylpeptide remined soluble when added to an assay mixture.) Fifty microliters of the supernatant were mixed with 75 μl methanol and 75 μl of HPLC buffer A, and analyzed by reverse phase HPLC on a 3.9 mm by 30 cm Waters μ-Bondapak C 18 column using the same HPLC buffers described above, starting at 35% acetonitrile and eluting with a 1% per minute acetonitrile gradient. One minute fractions were collected and the radioactivity in each fraction determined by liquid scintillation counting. [ 3 H]Myristoyl-GlyAsnAlaAlaAlaAlaArgArg eluted at 24 minutes, while [ 3 H]palmitoyl-GlyAsnAlaAlaAlaAlaArgArg eluted at 30 minutes.
Results
The chemically synthesized standards of [ 3 H]-myristoylglycylpeptide and [ 3 H]palmitoylglycylpeptide prepared as described above were found to elute from the reverse phase HPLC column with 59% and 65% acetonitrile, respectively, under the conditions used for analyzing assay samples. In the cell lysates prepared and fractionated into crude membranes and soluble fractions above, N-Myristoylglycylpeptide synthetase activity was detected in both crude membrane and soluble fractions, with the specific activities of total, soluble, and membrane fractions being 1410, 1320, and 2260 dpm per μg protein per 10 min assay, respectively. From the initial reaction velocities, it was estimated that 65% of the activity resided in the crude membrane fractions.
The enzymatic reaction product and the chemically synthesized standard [ 3 H]-myristoylpeptide were demonstrated to be identical and to contain myristate covalently bound to glycine when analyzed by the reverse phase HPLC as described above.
To demonstrate the specificity of the N-myristoylglycylpeptide synthetase for the peptide substrate, the ability of other glycylpeptides to competitively inhibit acylation of GlyAsnAlaAlaAlaAlaArgArg also was examined. As can be seen in Table I, below, Test 3, 1 mM concentrations of a dipeptide, a tetrapeptide, and a decapeptide had no effect on myristoylation of 18 μM peptide substrate (ca. one-eighth its K m ). Thus, the N-myristoylglycylpeptide synthetase exhibits specifity for the octapeptide substrate.
TABLE I______________________________________Characterization of N--myristoylglycine peptide synthase Rate of Myristoylpeptide SynthesisTest DPM × 10.sup.3 /10 min______________________________________1 Control 111- ATP 9- CoA 12 Control 83Heated Membranes (5 min/65°) 23 Control 26.7+ 1 mM GN 28.0+ 1 mM GPRP 25.6+ 1 mM GSSKSPKDPS 27.4______________________________________
Assays were carried out as described above, using crude membrane fractions from yeast with changes as indicated. In Test 1, the dependence of the assay on ATP and CoA was tested in the absence of exogenous fatty acid CoA ligase. In Test 2, it was demonstrated that the yeast enzyme is heat labile, and in Test 3, that addition of other peptides containing N-terminal glycine does not inhibit the reaction which in this test was measured using only 18 μM peptide substrate rather than the usual 90 μM, in order to maximize possible inhibitory effects.
EXAMPLE 3
Several octapeptides illustrating the present invention were synthesized by the solid phase Merrifield procedure essentially as described in Example 1 and then tested for activity as substrates or inhibitors for the myristoylating enzyme from yeast (S. cerevisiae strain JR153). The octapeptide substrate specificity of the enzyme was tested under the assay conditions described in Example 2 but using 1 μCi of [ 3 H]- myristic acid per assay tube. The yeast enzyme used in this example was partially purified from a crude homogenate of the cultured yeast cells by fractionation with 51-70% (NH 4 ) 2 SO 4 followed by ion exchange column chromatography with DEAE-Sepharose® CL-6B (Pharmacia) and affinity chromatography with CoA-agarose affinity matrix (Pharmacia). The octapeptides were characterized kinetically with the respective kinetic data (K m , V max and K i ) being shown in Table II, below.
TABLE II__________________________________________________________________________Octapeptide Substrate Specificity of YeastMyristoylating Enzyme K.sub.m Relative K.sub.iOctapeptide Sequence (mM) V.sub.max (%) (mM)__________________________________________________________________________Gly--Asn--Ala--Ala--Ala--Ala--Arg--Arg 0.06 100*Gly--Val--Ala--Ala--Ala--Ala--Arg--Arg 0.7 8 0.06Gly--Leu--Ala--Ala--Ala--Ala--Arg--Arg 0.3 5 0.06Gly--Tyr--Ala--Ala--Ala--Ala--Arg--Arg 0.15Gly--Phe--Ala--Ala--Ala--Ala--Arg--Arg 0.15__________________________________________________________________________ *The V.sub.max for this octapeptide substrate was 2840 pmol myristoyl peptide formed per minute per mg of the partially purified yeast enzyme.
The foregoing results were unexpected and surprising insofar as they show that the octapeptides with tyrosine or phenylalanine penultimate to the amine-terminal glycine bind to the myristoylating enzyme as indicated by their ability to competitively inhibit myristoylation of the Gly-Asn-Ala-Ala-Ala-Ala-Arg-Arg substrate, yet themselves failed to act as acyl acceptors at any specific rate. The octapeptides with leucine and valine residues at position 2 also inhibit myristoylation of the foregoing substrate.
Substantially similar results as above are obtained when one or two of the carboxy terminal arginines are deleted from the octapeptide.
Standard amino acid abbreviations are used to identify the sequence of the peptides herein as follows:
______________________________________Amino Acid Abbreviation______________________________________L-Alanine Ala or AL-Arginine Arg or RL-Asparagine Asn or NL-Aspartic acid Asp or DL-Glutamine Gln or QL-Glycine Gly or GL-Leucine Leu or LL-Lysine Lys or KL-Proline Pro or PL-Serine Ser or SL-Tyrosine Tyr or YL-Valine Val or V______________________________________
Various other examples will be apparent to the person skilled in the art after reading the present disclosure without departing from the spirit and scope of the invention, and it is intended that all such other examples be included in the scope of the appended claims. Thus, variations in the individual amino acids and/or the chain length of the peptides which do not adversely or detrimentally affect their biologic activity as inhibitors for myristoylating enzymes as defined herein are intended to be included within the scope of the appended claims.
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An octapeptide inhibitor of myristoylating enzymes is disclosed having an amino acid sequence selected from the group consisting of the following sequences or a physiologically acceptable amide or salt derivative thereof: ##STR1## wherein R=Leu, Phe, Tyr or Val.
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BACKGROUND OF THE INVENTION
a. Field of the Invention
This invention relates to a method and apparatus for performing a desired operation in a selected mandrel of a well having a tubing string and at least one mandrel at an intermediate location in the tubing string. More particularly this invention relates to a running assembly including operating tool means to perform the desired operation and selector stop means to positively locate the operating tool means with respect to the selected mandrel. The apparatus is constructed so that once the selector stop means locates the operating tool means, manipulation of the operating tool means to perform the desired operation disengages the selector stop means. Additionally, this invention relates to a method of utilizing a running assembly to positively locate operating tool means with respect to a selected mandrel when the tubing string has at least one mandrel at an intermediate location in the string, and from that location, manipulating the operating tool means to perform the desired operation in a selected mandrel.
B. The Prior Art
A well is often equipped with at least one mandrel in which an operation will be performed at an intermediate position within the tubing string. Generally a plurality of such mandrels are positioned within the tubing string and an identical operation may be performed in each mandrel. A single type of operating tool means may be utilized. To perform the operation in the proper mandrel the location of the tool must be known.
When wire line equipment is employed, it is possible to determine the location of the operating tool means with respect to any selected mandrel by measuring the length of the line that has been paid out.
Where pumpdown equipment is utilized no satisfactory method of determining the position of the operating tool has been available. Conventionally, two types of systems are used to ascertain the location of a pump down running assembly. Both systems are unable to positively locate the running assembly in intermediate positions in the tubing string.
One system attempts to locate the running assembly by measuring the amount of fluid pumped into the well. Inaccurate locations are calculated with this system because of fluid seepage past the pump down locomotives and because of trapped gases in the column of pumped fluids.
In the second conventional system, a plurality of nipples with a restrictive bore are placed in the tubing string. The running assembly is temporarily impeded when passing through such a nipple. The purpose of impeding movement of the running assembly is to create a registrable increase in fluid pressure. Unfortunately, such nipples also contribute to the hanging up of the running assembly. In addition, they do not provide a good indication of where the running assembly is located because it may also hang up on other obstructions in the tubing. Such an unintended hangup provides a pressure increase similar to the pressure increase which occurs when the running assembly passes through a restrictive bore nipple.
Thus, at depths in excess of several thousand feet, it is presently impossible to accurately locate the pumpdown running assembly in the drill string. As mandrels are often positioned within a couple of hundred feet of each other, the error associated with locating a pump down running assembly means that the operator is unable to ascertain if the running assembly is in the vicinity of a selected mandrel in which he wants to perform a desired operation or if it is in the vicinity of some other mandrel. Performing the operation in the wrong mandrel, at the very least, means that the running assembly has to be removed from the well, redressed, and rerun in an attempt to perform the operation in the selected mandrel, all at a considerable waste of time and expense. Other consequences of performing the operation in the wrong mandrel, such as killing the well, killing the wrong zone, treating the wrong zone, or allowing two zones to communicate with each other, are much more serious.
Some running assemblies include a locator tool means. The locator tool means carries locator keys which are matched with the internal recess of a predetermined locator nipple. Upon movement of the running assembly through the well tubing, the locator keys engage the recess of the predetermined locator nipple to position the running assembly. With the locator keys remaining in position, pins are sheared and/or telescoping sleeves moved to permit operation of the work tool. The locating tool means may be left in the tubing along with a work tool, as disclosed in U.S. Pat. No. 2,673,614 to Miller, or the locating tool means may be removed from the tubing leaving a locked tool similar to the "Model `A` Locking Device" and "Model `B` Locator Tool" disclosed in a Harold Brown Company brochure entitled "Wireline Production Equipment for Flow and Pressure Control". In either event, by positioning different locator keys on the locator tool means, the running assembly is located at a different locator nipple. Problems with such systems are that the operation is performed with the locator keys engaging the locating nipple, the keys interfere with the operation of the work tool, the amount and type of manipulations that may be made to the work tool are limited, and the work tool must employ a combination of shear pins and/or large telescoping sleeves to perform the desired operation.
Occasionally, even with a wireline, due to operator inattentiveness or a malfunction of the line counter, the running assembly may overshoot the desired operating mandrel. The running assembly then must be relocated in the well before the desired operation may be performed.
OBJECTS OF THE INVENTION
It is an object of this invention to provide a method and apparatus for locating a pumpdown or wireline running assembly with respect to a selected mandrel at an intermediate position within the well from which location the running assembly may be moved to permit performance of the desired operation in the selected mandrel.
It is a further object of this invention to provide a means for locating a pumpdown running assembly within a tubing from which location the running assembly is moved so that, (i) the locating means does not interfere with the performance of the operation, (ii) the amount and type of manipulations of a work tool is not limited, and (iii) the work tool is not limited to a combination of shear pins and/or large telescoping sleeves to perform the desired operation.
Additionally, it is an object of this invention to provide a method of performing a desired operation in a selected mandrel of a well wherein the pumpdown running assembly is positively located and then moved to a second position where the work tool can be manipulated to perform the desired operation.
These and other objects, features, and advantages of this invention will be apparent from the drawings, the detailed description, and the appended claims.
BRIEF DESCRIPTION OF THE DRAWINGS
In the drawings wherein like numerals indicate like parts and wherein illustrative embodiments of this invention are shown,
FIG. 1 is a fragment and sectional view of a well tubing and casing string having a plurality of stop nipples and side pocket mandrels;
FIG. 2 is a view in elevation of a running assembly including selector stop means and kickover tool means;
FIGS. 3, 4, 5, and 6 are a series of views, partially in elevation and partially in section, showing running and manipulation of the selector stop means and the kickover tool means of FIG. 2 to install equipment in a specified side pocket mandrel;
FIG. 7 is a view in elevation of a running assembly including selector stop means and operating tool means adapted to shift a sleeve valve means in the tubing string; and
FIG. 8 is a view partially in elevation and partially in section of the selector stop means and operating tool means of FIG. 7 in position to shift a sleeve valve means in the tubing string.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
A tubing string 10 is normally run with at least one mandrel at an intermediate location in the tubing string, in which it will be desired to perform an operation. The tubing string 10 will be in a casing 12 of a well for producing fluids.
When the well is equipped to employ gas lift recovery, a plurality of mandrels, such as side pocket mandrels 14, may be provided in the tubing string 10. The side pocket mandrel 14 includes a bore 16 extending therethrough of generally the same size and aligned with the bore of the tubing string 10. The mandrel 14 also includes a side pocket receptacle 18 for receiving and retaining equipment. The side pocket mandrel 14 engages an operating tool means, commonly known as a kickover tool means, during the installation or retrieval of equipment from the side pocket receptacle 18. When, as illustrated, there are more than one side pocket mandrel 14 in the tubing string 10, on a single run of the kickover tool means, one piece of equipment is installed or retrieved from a selected side pocket mandrel 14.
Means are provided in the tubing string 10 to selectively cooperate with means on the running assembly to positively locate the running assembly with respect to at least one of the intermediately spaced mandrels 14. The selective, cooperable, locating means in the tubing string 10 is a stop nipple 20 such as that disclosed in U.S. Pat. No. 2,673,614 to Miller; such patent being hereby incorporated by reference for all purposes. When, as illustrated, a plurality of mandrels 14 are positioned at spaced locations within the tubing string 10, a plurality of stop nipples 20 are preferably also positioned at spaced locations within the tubing string 10. To provide a means for selectively locating the running assembly with respect to different mandrels 14 each stop nipple 20 is positioned with respect to a different one of the mandrels 14 and each stop nipple 20 is positioned a known distance from at least one of the mandrels 14. It will be apparent that a single nipple 20 might be utilized to locate more than one mandrel 12 when the mandrels are sufficiently close together.
Although the operational tools can be run into the well on a conventional wireline, or the like, they will be herein described as being moved in and out of the well by pumped fluids as in conventional pump down operations.
The running assembly to be run in the tubing string 10 includes pump down locomotive means 22, selector stop means 24, and operating tool means 26.
The illustrated pump down piston locomotive means 22 is conventional in form and connected to the selector stop means 24 but it is to be understood that the locomotive means 22 could be attached to either or both of the operating tool means 26 and the selector stop means 24. The pumpdown locomotive means 22 may be a pair of oppositely facing swab cups obtainable from TRW Mission in Houston, Texas. The attachment may be through a set of jars (not shown) so that a jarring force may be applied during the manipulation and operation of the operating tool means 26. The pump down locomotive means 22 is responsive to the action of fluid pumped in the tubing string 10 to move the running assembly in either direction through the tubing string 10.
The selector stop means 24 cooperates with a selected stop nipple 20 to limit the movement of the running assembly in one direction through the tubing string 10. The stopping of the running assembly by the cooperation of selector stop means 24 and the selected stop nipple 20 positively locates the running assembly with respect to the selected mandrel 14. The illustrated selector stop means 24 and nipple 20 are the same as those shown in the aforesaid U.S. Patent to Miller. Different key configurations and mating nipples permit the stop means to land in selected nipples. (Note that the recesses in nipple 20 and 20a are different lengths and a key designed to fit nipple 20a will not fit nipple 20).
The illustrated operating tool means 26 is a kickover tool means. The kickover tool means 26 is identical to the kickover tool disclosed in U.S. Pat. No. 3,837,398 to John H. Yonker, the entire disclosure of which is hereby incorporated by reference. The kickover tool means operates, in the manner described in the aforesaid patent, to install or retrieve equipment from the side pocket receptacle 18 of side pocket mandrels 14.
Means are provided for connecting together the operating tool means 26 and the selector stop means 24. The connecting means spaces the operating tool means 26 a sufficient distance from the selector stop means 24 so that the selector stop means 24 is disengaged from the selected stop nipple 20 when the operating tool means 26 is in a position to coact with the selected mandrel 14 to effect operation of the operating tool means 26. The operating tool means 26 and the selector stop means 24 are thus connected together such that when the selector stop means 24 has engaged a selected stop nipple 20, the distance between the operating tool means 26 and the selector stop means 24 is less than the distance between the selected stop nipple 20 and the selected mandrel 14. The connecting means may be a separate sub connecting the operating tool means 26 with the selector stop means 24, or alternatively, each of the operating tool means 26 and the selector stop means 24 may have means, such as interconnecting threads, for connecting one to the other.
Referring now to FIGS. 3 through 6, the method in which equipment is installed or retrieved from one selected mandrel 14 of the well will be described.
The running assembly is made up to include the pump down locomotive means 22, the selector stop means 24 and the kickover tool means 26. Although there may be a plurality of stop nipples in the tubing string 10, the selector stop means is designed to cooperate only with one selected stop nipple 20.
The running assembly is run downward through the tubing string 10 by fluid pressure. Dummy valves (not shown) will block flow through all mandrels above the working mandrel. Thus flow will pass through the working mandrel to a circulating port (not shown) provided below the lowermost side pocket mandrel or other landing nipple, sliding sleeve or the like (not shown), which is to cooperate with the tool string 26. The pumped fluids flow through such port into the casing-tubing annulus to return to the surface. Since the selector stop means and nonselected stop nipple are not designed to cooperate with each other, the running assembly may be run past any number of such nonselected stop nipples 20. In this manner the running assembly is run through the tubing string 10 past side pocket mandrels 14 in which it is not desired to install or retrieve equipment.
When the running assembly is attempted to be run through the one selected stop nipple 20, the selector stop means 24 cooperates with the stop nipple 20 to stop further downward movement of the running assembly. At this time the pumpdown locomotive means 22 is above the selected mandrel 14 while the kickover tool means has been run past the operating location of the selected mandrel 14 and is in an inoperable position within the tubing string 10. However, the kickover tool means 26 is positively located a known distance below the selected mandrel 14. The stopping of the downward movement of the running assembly to positively locate the kickover tool means 24 with respect to side pocket mandrel 12 is depicted in FIG. 3. Now, by utilizing a given sequence of manipulations, the kickover tool means 26 can engage the side pocket mandrel 12 to perform the desired operation therein.
To manipulate the kickover tool means, fluid pressure is applied to the casing-tubing annulus and the tubing at the surface is opened to permit the stop means 24 to disengage from the stop 20 nipple and the running assembly is moved upwardly in the tubing string 10 until the kickover tool is actuated as it becomes positioned in the selected mandrel 14 in the usual manner with respect to the side pocket 18 and is run downwardly again to install equipment 28 in the side pocket as illustrated in FIG. 4.
If desired,, while the kickover tool means 26 is being run upward, it can be oriented by the engagement of locator key means 30 with an orienting sleeve means 32 in the tubing string 10. The orienting of the kickover tool means 26 orients the kickover tool means 26 with respect to the side pocket receptacle of the selected side pocket mandrel 14.
While the kickover tool means 26 is engaging the selected side pocket mandrel 14 to install or retrieve equipment, the selector stop means 24 remains disengaged from the selected stop nipple 20. With the selector stop means 22 thus disengaged, the selector stop means does not interfere with the performance of the operation, the manipulations to operate the kickover tool means 26 are not limited, and a kickover tool means rather than a work tool having only a combination of shear pins and/or telescoping sleeves can be employed.
FIGS. 4, 5 and 6 show the manipulation of the kickover tool means 26 disclosed in the aforesaid U.S. Pat. No. 3,837,398 to install equipment 28 in the side pocket receptacle 18 of the selected mandrel 14. As disclosed in the aforementioned patent, manipulation of the kickover tool means 26 to install equipment 28 includes moving the tool upward through the tubing until the dog means 34 associated with said kickover tool means 26 engages stop means 36 in the tubing string 10. A continued upward application of force actuates or activates the kickover tool means 26. The kickover tool means 26 may then start its downward motion (See FIG. 4) and is moved downwardly until equipment 28 is installed in the side pocket receptacle 18 as shown in FIG. 5. Once the equipment 28 is installed, the kickover tool means 26 can be removed from the tubing string 10 by movement in an upward direction as shown in FIG. 6.
Mandrels, other than side pocket mandrels, may be positioned at intermediate locations in the well tubing string. For example, the tubing string 38 could include at least one mandrel 40 (FIGS. 7 and 8) with a shifting sleeve valve means comprising a sleeve 42 and port means 44. The mandrel 40 with its shifting valve means could be the same as that disclosed in U.S. Pat. No. 3,638,723 issued Feb. 1, 1973 to Albert W. Carroll; the disclosure of said patent being hereby incorporated by reference for all purposes.
To selectively locate a running assembly with respect to any such intermediately positioned mandrel 40, the well would also include at least one stop nipple 20b as previously described. The stop nipples 20b would be positioned a known distance from at least one of the mandrels 40 and each such stop nipple would be positioned with respect to a different mandrel 40.
The running assembly would then include a pump down locomotive means, selector stop means 24b, and operating tool means 46.
The pump down locomotive means is conventional and in conjunction with fluid being pumped through the tubing string 38 operates to transport the running assembly in either direction through the tubing string 38.
The selector stop means 24b is designed to be cooperable with the stop nipple 20b to selectively limit movement of the running assembly in one direction through the tubing string.
The operating tool means 46 may be the shifting tool disclosed in the aforesaid U.S. Pat. No. 3,638,723. It is designed to perform the operation of shifting sleeve 42 of mandrel 40.
The operating tool means 46 and the selector stop means 24b are connected together so that when the selector stop means 24b is cooperating with the selected stop nipple 20b to positively locate the running assembly, the operating tool means 46 is not engaging mandrel 40 to shift sleeve 42. However, when the operating tool means 46 is engaging mandrel 40 to shift sleeve 42 the selector stop means 24b no longer cooperates with nipple 20b but is instead disengaged from the nipple.
To perform the operation of shifting a sleeve in a selected mandrel 40, the running assembly is run downward through the tubing string 38 by circulating fluid. The selector stop means 24b cooperates with the selected stop nipple 20b to limit the downward movement of the running assembly. This positively locates the running assembly with respect to the selected mandrel 40. From this location, the running assembly is moved upwardly by reverse circulation until the operating tool means 46 passes sleeve 42. In passing sleeve 42, the shifting tool means 46 is activated to its operative position. The operating tool means 46 is then circulated downward to engage selected mandrel 40 to shift sleeve 42 down as shown in FIG. 8. While the operating tool means 46 is engaging mandrel 40 it can be seen that the selector stop means 24b is disengaged from the selected stop nipple 20b. (FIG. 8)
It can thus be appreciated that a novel method and apparatus combination has been provided to enable a pumpdown running assembly to perform a desired operation in any selected mandrel.
Mandrels in addition to the illustrated side pocket mandrels 14 and the shifting sleeve valve mandrels 40, may be employed in accordance with this invention. The mandrels may be any type of mandrel in which a desired operation is performed. The operations include inserting equipment, retrieving equipment, opening a valve, closing a valve, shifting a sleeve, etc. The operating mandrel would include appropriate components to engage the operating tool means to perform the desired operation. A plurality of identical mandrels may be positioned at spaced locations in the tubing string. The desired operation may be performed in any one of the mandrels without performing it in others.
The stop nipples may be any means in the well that can cooperate with means on the running assembly to selectively stop movement of the running assembly through the well in one direction. At least one stop nipple is provided and it is positioned a known distance from a selected mandrel. Preferably, as many stop nipples as mandrels are provided. Then each stop nipple may be positioned a known distance from a different one of the mandrels.
The selector stop means of the running assembly is then any means that can cooperate with and engage the stop nipples to limit further movement of the running assembly in one direction through the well. It does not limit movement of the running assembly in the other direction through the well. Indeed, the running assembly is moved in said other direction once it is positively located by the cooperating engagement of the selector stop means and the stop nipple to position the operating tool means in the vicinity of the selected mandrel.
The operating tool means is any tool that will perform the desired operation. The tool may be universal, that is, the tool can be one that can perform the operation in all of the mandrels. It is then the combination of the stop nipple and the running assembly having a selector stop means and the operating tool means which enables the desired operation to be performed in a selected one or more mandrels. The operating tool means and the selector stop means are connected together so that when the selector stop means is cooperating with the stop nipple to positively locate the running assembly the operating tool means is not engaging the selected mandrel and cannot perform the desired operation. However, when the operating tool means is engaging the selected mandrel and is performing the desired operation the selector stop means no longer cooperates with and engages the stop nipple. In this manner the manipulations that may be made to the operating tool means is not limited, nor is the design of the operating tool means limited.
It can be seen from the foregoing that the objects of this invention have been obtained. An apparatus has been provided which enables a running assembly to be selectively located in the well but which does not limit the type of manipulations nor construction of an operating tool means. A method of performing a desired operation in a selected mandrel in a well has been provided whereby a running assembly is located and from which location is moved to another location to permit operating tool means to perform a desired operation.
The foregoing disclosure and description of the invention are illustrative and explanatory thereof and various changes in the size, shape and materials, as well as in the details of the illustrated construction may be made within the scope of the appended claims without departing from the spirit of the invention.
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An apparatus and method for performing a desired operation in a selected mandrel in a well. The apparatus includes a running assembly with selector stop means and operating tool means. The running assembly is run in the tubing string until the selector stop means positively locates it with respect to the selected mandrel. The operating tool means can then be manipulated to perform the desired operation in the selected mandrel. This abstract is neither intended to define the invention of the application which, of course, is measured by the claims, nor is it intended to be limiting as to the scope of the invention in any way.
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CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This present application is a continuation-in-part of U.S. application Ser. No. 09/688,437 filed on Oct. 16, 2000.
BACKGROUND OF INVENTION
[0002] The invention is related to sonic logging of earth formations. More specifically, the invention is related to methods for processing sonic logging instrument signals to improve the quality of estimation of certain formation properties.
[0003] Description of Related Art
[0004] In the oil and gas industry, subsurface formations are typically probed by well logging tools to determine formation characteristics which can be used to predict or assess the profitability and producibility of subsequent drilling or production operations. In many cases, acoustic logging tools are used to measure formation acoustic properties which may be used to produce images or derive related characteristics for the formations.
[0005] Acoustic waves are periodic vibrational disturbances resulting from acoustic energy which propagates through a medium, such as the subsurface formation. Acoustic waves are typically characterized in terms of their frequency, amplitude, and speed of propagation. Acoustic properties of interest for formations may include compressional wave speed, shear wave speed, borehole modes, and formation slowness. Additionally, acoustic images may be used to depict borehole wall conditions and other geological features away from the borehole. These acoustic measurements have applications in seismic correlation, petrophysics, rock mechanics and other areas.
[0006] Recordings of acoustic properties as functions of depth are known as acoustic logs. Information obtained from acoustic logs may be useful in a variety of applications, including well to well correlation, determining porosity, determining mechanical or elastic parameters of rock to give an indication of lithology, detecting over-pressured formation zones, and enabling the conversion of a seismic time trace to a depth trace based on the measured speed of sound in the formation.
[0007] Sonic logging of earth formations entails lowering an acoustic logging instrument into a wellbore traversing the formations. The instrument typically includes one or more acoustic sources (i.e., a transmitter) for emitting acoustical energy into subsurface formations and one or more acoustic receivers for receiving acoustic energy. The transmitter is periodically actuated to emit pulses of acoustic energy into the wellbore, which travel through the wellbore and into the formation. After propagating through the wellbore and formation, some of the acoustic energy travels to the receivers, where it is detected. Various attributes of the detected acoustic energy are subsequently related to subsurface or tool properties of interest.
[0008] [0008]FIG. 1 shows a conventional sonic logging instrument. The instrument 10 is shown disposed in a wellbore 12 traversing an earth formation 20 . The wellbore 12 is typically filled with a drilling fluid 14 (also called “mud”) that is used during the drilling of the wellbore. The instrument 10 is generally implemented in a tubular 13 support, which in the case of a drilling tool includes a passage 13 A through its center for pumping the drilling fluid 14 to a mud motor (not shown) and/or a drill bit (not shown) at the bottom of a drill string (not shown). The logging instrument 10 includes one or more acoustic transmitters 16 and a plurality of acoustic receivers 18 disposed in the tubular 13 . The receivers 18 are shown spaced apart from each other, along the longitudinal axis of the instrument 10 , at a selected distance h. One of the receivers 18 closest to the transmitter 16 is axially spaced therefrom by a selected distance a. It will be appreciated by those skilled in the art that even though the instrument shown in FIG. 1 has the same distance h between each of the receivers, the distance between each receiver is variable. The instrument 10 also houses one or more conventional computer modules 21 including processors, memory, and software to process waveform signal data as known in the art. As also known in the art, the computer module(s) 21 can be disposed within the instrument, at the earth surface, or combined between the two as shown in FIG. 1. Conventional sonic logging instruments are further described in U.S. Pat. Nos. 5,852,587, 4,543,648, 5,510,582, 4,594,691, 5,594,706 and 6,082,484.
[0009] In operation, the instrument transmitter 16 is periodically actuated or “fired”, sending pulses of acoustic energy, shown generally at 22 , into the drilling fluid 14 where they travel through the wellbore 12 , and are eventually detected by the receivers 18 . Depending on the axial spacings a and h, on the types of transmitter and receivers used, and on the acoustic characteristics of the particular earth formations penetrated by the wellbore adjacent the instrument 10 , the receivers 18 will generate electrical signals in response to the acoustic energy which have particular waveforms. Examples of such waveforms are shown in FIG. 2A at 30 , 32 , 34 , and 36 . Typically each waveform 30 , 32 , 34 , and 36 will include a relatively high amplitude event 30 A, 32 A, 34 A, 36 A, respectively, which corresponds to the arrival from the earth formation of the energy which was emitted from the transmitter 16 and has passed along the wellbore wall. The time at which each high amplitude event 30 A, 32 A, 34 A, 36 A actually occurs in each waveform depends on the axial spacing of the particular receiver, the acoustic properties (particularly acoustic velocity) of the particular earth formations between the transmitter and receivers, and on the lateral and angular position of the instrument in the wellbore. Similarly, examples of waveforms made by successive firings of the transmitter 16 are shown in FIG. 2B at 38 , 40 , 42 and 44 ; in FIG. 2C at 46 , 48 , 50 and 52 ; and in FIG. 2D at 54 , 56 , 58 and 60 .
[0010] Processing techniques known in the art for determining compressional and/or shear velocity include correlation of the acoustic energy waveforms detected at the receivers. The correlation is performed using various values of slowness (inverse of velocity) until a degree of coherence between all the waveforms reaches a maximum. The value of slowness (or velocity) at which the degree of coherence is determined to be at a maximum is selected as the slowness or velocity for the formation interval in which the receivers are disposed at the time the transmitter is actuated.
[0011] The certainty or accuracy of the velocity determination using correlation techniques can be improved by summing the waveforms (also know as “stacking”) detected at the receivers for a selected number of transmitter actuations, such as shown in FIGS. 2A through 2D, and determining the slowness time coherence (STC) from the stacked waveforms. In STC processing, the measured signal is typically time window “filtered” and stacked, and a semblance function is computed. The semblance function relates the presence or absence of an arrival with a particular slowness and particular arrival time. If the assumed slowness and arrival time do not coincide with that of the measured arrival, the semblance takes on a smaller value. Consequently arrivals in the received waveforms manifest themselves as local peaks in a plot of semblance versus slowness and arrival time. These peaks are typically found in a peak-finding routine. Coherence techniques such as STC or semblance-based calculations are further described in U.S. Pat. Nos. 4,543,648, 4,594,691, and 5,594,706 (all incorporated herein by reference).
[0012] It should be noted that the example waveforms of FIGS. 2A through 2D are simulated compressional waveforms for an earth formation having a compressional interval velocity of 100 microseconds per foot (328 microseconds/meter). Random noise has been added to each simulated waveform. The actual waveforms of the detected acoustic energy, the arrival times and the noise type will of course depend on formation and instrument factors.
[0013] Conventional waveform correlation techniques have been useful in cases where the logging instrument is moved slowly or is small compared to the wellbore, such as in conventional “wireline” logging operations. U.S. Pat. No. 4,819,214 to Gutowski et al. describes a wireline sonic logging tool using an N-th root filter to determine coherence. However, with measurements made during the drilling of the wellbore (known as “logging-while-drilling” (LWD)) conventional correlation techniques have proven less useful. One reason for these correlation techniques being less effective in LWD applications is due the violent vibration and movement the instrument sustains during the drilling operation.
[0014] Prior art methods for calculating slowness have been less than satisfactory because waveforms from successive transmitter firings detected at the same receiver have been known to vary so much in character and arrival time that stacking may result in near total loss of the true signal. A substantial cause of the waveform variation is the vibration and lateral motion/eccentering of the logging instrument, which hinders true signal detection, particularly in LWD operations.
[0015] [0015]FIG. 3 shows a flow chart of a conventional technique for calculating slowness, wherein the transmitter is repeatedly fired at 62 , 66 , 70 and the measured signal waveforms are stacked together at 71 by combining samples taken from the different transmitter actuations. A coherence measurement is then performed on the stacked waveforms, at 76 . A coherence plot 77 (See FIG. 5A) is then obtained from the coherence measurement and the formation slowness is derived from the coherence measurement. As previously discussed, the variance between the detected waveforms can substantially alter true signal recognition. The loss of true signal character is compounded in the stacking, resulting in an unreliable slowness calculation.
[0016] There remains a need for techniques to improve the certainty and accuracy of sonic velocity determination.
SUMMARY OF INVENTION
[0017] One aspect of the invention provides a system for sonic logging of an earth formation. The system comprises a logging instrument adapted for disposal within a wellbore traversing the formation; at least one acoustic transmitter disposed on the logging instrument; at least one receiver adapted to detect acoustic signals disposed on the logging instrument; processor means adapted to process acoustic signals to determine a coherence measure from acoustic signals detected by the at least one receiver and associated with the at least one transmitter actuations; and processor means adapted to average the coherence measure for a plurality of the at least one transmitter actuations to determine a property of the formation.
[0018] One aspect of the invention provides a system for sonic logging of an earth formation. The system comprises a logging instrument adapted for disposal within a wellbore traversing the formation; at least one acoustic transmitter disposed on the logging instrument; at least one receiver adapted to detect acoustic signals disposed on the logging instrument; processor means adapted to process acoustic signals without stacking the signals to determine a coherence measure from acoustic signals detected by the at least one receiver and associated with the at least one transmitter actuations; and processor means adapted to average the coherence measure for a plurality of the at least one transmitter actuations to determine a property of the formation.
[0019] One aspect of the invention provides a method for sonic logging of an earth formation. The method comprises repeatedly actuating an acoustic transmitter on a well logging instrument disposed in a wellbore traversing the formation; detecting acoustic signals with at least one receiver disposed on the instrument; determining a coherence measure from the detected acoustic signals associated with the at least one transmitter actuations; and averaging the coherence measure for a plurality of the transmitter actuations to determine a property of the formation.
[0020] One aspect of the invention provides a method for sonic logging of an earth formation. The method comprises repeatedly actuating an acoustic transmitter on a well logging instrument disposed in a wellbore traversing the formation; detecting acoustic signals with at least one receiver disposed on the instrument; determining a coherence measure from the detected acoustic signals associated with the at least one transmitter actuations without stacking the signals; and averaging the coherence measure for a plurality of the transmitter actuations to determine the slowness of the formation.
[0021] Other aspects and advantages of the invention will be apparent from the description which follows and the accompanying drawings.
BRIEF DESCRIPTION OF DRAWINGS
[0022] [0022]FIG. 1 shows a representative sonic logging instrument that can be used with the invention.
[0023] [0023]FIGS. 2A through 2D show synthesized receiver waveforms from sonic transmitter firings.
[0024] [0024]FIG. 3 shows a flow chart of a prior art technique for determining formation slowness.
[0025] [0025]FIG. 4 shows a flow chart of an embodiment of a process according to the invention.
[0026] [0026]FIGS. 5A and 5B respectively show a comparison of results obtained using prior art processing and multichannel coherence measure processing according to the invention, using as signals the waveforms shown in FIGS. 2A through 2D.
[0027] [0027]FIG. 6 shows an example of velocity calculation results obtained using an embodiment of the invention compared with results obtained using prior art methods including wireline techniques.
DETAILED DESCRIPTION
[0028] The present invention provides an improved technique for determining formation slowness. FIG. 4 illustrates the general process of the invention. Transmitter 1 is fired, at 62 , generating waveforms such as 30 - 36 in FIG. 2A. These waveforms are used to calculate a coherence measure at 64 and to generate a slowness time coherence plot at 65 . Similarly, for transmitter firing number 2 , at 66 , the resulting receiver waveforms are used to calculate a coherence measure at 68 and to generate a slowness time coherence plot at 69 . This continues for a selected number of transmitter firings, N, at 70 to calculate the N-th coherence measure at 72 and to generate the N-th slowness time coherence plot at 73 . The multichannel coherence measure produces N slowness time coherence plots. The multichannel coherence measure is then averaged at 74 to generate an average coherence plot (See FIG. 5B). The averaged coherence 74 is then used to determine the formation slowness using conventional techniques as known in the art, for example as described in U.S. Pat. Nos. 4,543,648, 4,594,691 and 4,543,648.
[0029] As known in the art, the sonic waveforms can be processed in digital and/or analog form. The detection of acoustic signals by the receivers 18 may take place at one time and processing of the waveform signals in accordance with the invention may be done at another time, or processing may be done while the instrument 10 is being moved and operated in the wellbore. The term acoustic waveform signals, as used herein, includes both real-time and subsequent use of signals detected by the instrument.
[0030] It will be understood that slowness time coherence is one form of calculating a mutichannel coherence measure of the detected acoustic energy. Those skilled in the art will recognize that the present invention can be implemented with other methods for calculating multichannel coherence of the detected acoustic signals. Some embodiments may use coherence calculation techniques other than semblance techniques to determine velocity (not shown).
[0031] A comparison of the processing results from prior art methods with those obtained using the techniques of the invention can be observed in FIGS. 5A and 5B. FIG. 5A shows a plot of prior art STC processing using the waveforms shown in FIGS. 2A through 2D, wherein the detected waveforms are combined and stacked from successive transmitter actuations (See FIG. 3). The STC is a three dimensional plot of coherence versus arrival time and slowness. As can be observed at 78 in FIG. 5A, the coherence of the stacked waveforms is relatively low, and the calculated slowness is inaccurate.
[0032] [0032]FIG. 5B shows a coherence plot calculated using an embodiment of the invention and the waveforms shown in FIGS. 2A through 2D. Combining the coherence values from various firings in the slowness/time plane produces the averaged coherence measure. As can be observed at 80 , the semblance shows a much higher coherence value resulting in a more accurate slowness calculation.
[0033] An example of results obtained using embodiments of the invention to determine velocity as compared with a prior art method is shown in FIG. 6. Velocity (slowness) calculation using a conventional method on data acquired using an LWD instrument is shown at curve 106 . Velocity calculation using a conventional method on data acquired with a wireline-conveyed instrument is shown at curve 102 . LWD sonic signal data processed according to the techniques of the invention is shown at curve 104 . As can be observed in FIG. 6, the invention produces comparable to wireline-acquired data from LWD acquired data, whereas prior art methods produced noisy and/or erratic results from such data.
[0034] It will be apparent to those skilled in the art that the invention can be implemented by programming one or more suitable general-purpose computers/processors, such as the computer module(s) 21 shown in FIG. 1, to perform the techniques of the invention. Such computer modules are described in U.S. Pat. No. 5,594,706. The programming may be accomplished through the use of one or more program storage devices (memory modules in the computer module 21 ) readable by the processor and encoding one or more programs of instructions executable by the computer/processor for performing the operations described herein.
[0035] The program storage device may take the form of, e.g., one or more floppy disks; a CD-ROM or other optical disk; a magnetic tape; a read-only memory chip (ROM); and other forms known in the art or subsequently developed. The program of instructions may be “object code,” i.e., in binary form that is executable more-or-less directly by the computer; in “source code” that requires compilation or interpretation before execution; or in some intermediate form such as partially compiled code. The precise forms of the program storage device, the encoding of instructions, and of the type of processor(s) are immaterial here.
[0036] As shown in FIG. 1, the instrument 10 can be implemented with internal computer modules 21 , or the module(s) can be located on the earth surface as known in the art. Once acquired, the data may be stored and/or processed downhole or communicated to the surface in real via conventional telemetry systems known in the art. An example of “mud-pulse” telemetry techniques used in sonic LWD is described in U.S. Pat. No. 5,852,587.
[0037] Other embodiments of the invention can be devised which do not depart from the scope of the invention. For example, by the principle of reciprocity, a sonic logging instrument 10 of the invention can be configured wherein the receivers 18 are substituted by transmitters, the transmitter 16 is substituted by receivers. The instruments of the invention are equipped with conventional electronics, circuitry, and software to activate the sources and sensors to obtain the desired measurements as known in the art. It will also be appreciated that while the invention is particularly suited to LWD applications, there is no reason why the techniques of the invention cannot be applied to other logging implementations, including wireline instruments, coiled tubing conveyed measurements, logging-while-tripping, or sonic logging measurements made by any other conveyance mechanism known in the art.
[0038] For the purposes of this specification it will be clearly understood that the word “comprising” means “including but not limited to”, and that the word “comprises” has a corresponding meaning.
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The invention provides techniques for calculating velocity from sonic signals with an improved signal to noise ratio, accuracy and certainty of result. Multichannel coherence measures are calculated from sonic transmitter signals and averaged to produce an average coherence measure. The formation slowness is determined from the averaged coherence measure.
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TECHNICAL FIELD
This invention relates generally to the field of health care and physical therapy. More particularly, the invention relates to a method of ultrasonic therapy in which, prior to the application of ultrasonic energy, the site at which the ultrasonic transducer is to come into contact with the patient's skin is treated topically with a formulation which enhances the therapeutic effects of ultrasonic energy.
BACKGROUND OF THE INVENTION
Physical therapists have long utilized therapeutic ultrasound because of its thermal and mechanical effects on tissue. Ultrasound (sound at a frequency greater than approximately 20 KHz.) can be produced by applying an alternating electrical current, at the desired frequency, to a transducer incorporating a piezoelectric crystal. The current causes the shape of the crystal to oscillate between a resting state and a different state, thereby producing a sonic wave. The sonic wave can be continuous or pulsed, depending on how the transducer is driven.
Typical indications calling for ultrasonic therapy include tendinitis, bursitis, carpal tunnel syndrome, neck pain and lower back pain. Continuous ultrasound is typically used when thermal effects are desired, for example to reduce muscle spasm. On the other hand, pulsed ultrasound is often preferred for treatment where heat exacerbates pain in the patient, or when only non-thermal, mechanical effects of ultrasound, e.g. enhancement of tissue regeneration, are desired.
In transdermal ultrasonic therapy, a coupling gel is used between the transducer and the patient's skin to eliminate any layer of air, and thereby reduce reflections resulting from the difference in the acoustical impedances of air and the transducer. Typical coupling agents are mineral oil, glycerin, propylene glycol, water and water-based gels.
Ultrasonic therapy is widely used, but for effective treatment, it has generally been necessary to apply ultrasonic energy either at a high intensity or for long intervals of time, or both. An important object of this invention is to provide a method for carrying out ultrasonic therapy in which the transmission of ultrasonic energy through the patient's skin is enhanced.
SUMMARY OF THE INVENTION
In accordance with the invention, a solution of a nicotinic acid ester is applied to a defined area of a patient's skin overlying a tissue lesion to be treated. The nicotinic acid ester is applied to the defined area of the patient's skin by means of a swab pre-saturated with a mixture including the nicotinic acid ester and an alcohol. Following the application of the nicotinic acid ester, ultrasonic energy is applied to the internal tissue lesion by a transducer in contact with the defined area to which the nicotinic acid ester was applied. It has been found that the nicotinic acid ester and the ultrasonic energy, acting together, produce a surprising effect as exhibited by measurements of cutaneous circulation (perfusion). The application of the nicotinic acid ester to the skin apparently produces a hydration of the stratum corneum (the surface layer of the patient's epidermis), which, prior to hydration, has a relatively high acoustic impedance compared to the that of the underlying epidermal and dermal layers and the overlying coupling agent. Hydration of the stratum comeum causes its acoustic impedance to approach that of the underlying layers and the coupling agent. The modification of the impedance of the stratum corneum reduces the reflection coefficients at the interface between the stratum corneum and the underlying granular layer of the epidermis and at the interface between the coupling agent and the stratum corneum, thereby improving the transmission of ultrasonic energy to the internal tissue lesion.
A preferred nicotinic acid ester is methyl nicotinate, applied in a solution containing approximately 1% (wt.) methyl nicotinate, approximately 10%-20% (wt.) isopropyl alcohol and water. The frequency of the ultrasonic energy is preferably in the range of approximately 700 KHz. to 3500 KHz.
Other objects, advantages and details of the invention will be apparent from the following detailed description, when read in conjunction with the drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is an elevational view of a swab stick for applying the nicotinic acid ester solution according to the invention, showing the package containing the swab stick opened and partially broken away;
FIG. 2 is a schematic cross section showing an ultrasonic transducer, a layer of coupling agent, the patient's epidermis, and part of the dermis, with the direction of the transmitted ultrasound and its reflections being shown by arrows;
FIG. 3 is a schematic cross section showing an ultrasonic transducer, a layer of coupling agent, and the stratum corneum of the patient's epidermis, the stratum corneum being untreated, as in the prior art; and
FIG. 4 is a schematic cross section showing an ultrasonic transducer, a layer of coupling agent, and the stratum corneum of the patient's epidermis, the stratum corneum being treated with a nicotinic acid ester in accordance with the invention.
DETAILED DESCRIPTION
Ultrasonic therapy in accordance with the invention is preferably carried out by utilizing a pre-packaged methyl nicotinate swab stick 10 as shown in FIG. 1, the stick comprising a stiff, extruded tube 12 of plastics material, e.g. polyethylene, having a quantity of fiber affixed at one end in the form of a dense bulb 14, saturated with a solution of a nicotinic acid ester, preferably a solution consisting of approximately 1% (wt.) methyl nicotinate, approximately 10% (wt.) isopropyl alcohol, and water. The fiber can be a natural fiber such as cotton, a synthetic cotton-like material such as rayon, or a blend of natural and synthetic fibers.
The pre-saturated swab stick 10 is supplied enclosed in a package 16 made from two sheets 18 and 20, each consisting of a layer of coated paper and a layer of aluminum foil, the paper layer of sheet 18 being indicated at 22 and the foil layer of sheet 18 being indicated at 24. The two sheets are adhesively secured to each other along a border 26 to form an air and liquid-tight enclosure for the swab stick.
Isopropyl alcohol is preferably present in the methyl nicotinate solution because of its antiseptic properties, to increase the shelf life of the swab stick, to aid in cleansing the surface of the skin, and to enhance the penetration of the methyl nicotinate into the skin by fluidizing the lipid barriers in the skin. To be effective, the amount of isopropyl alcohol in the solution should be at least 10% by weight based on the total weight of the solution.
Prior to treatment with ultrasonic energy, a defined area of the patient's skin is swabbed with the methyl nicotinate solution. The defined area overlies the tissue lesion being treated. Immediately after the area is swabbed with the methyl nicotinate solution, a coupling agent is applied to the same area and an ultrasonic transducer is brought into contact with the defined area through the coupling agent, and operated.
When therapeutic ultrasound is applied to a patient, it is usually in the frequency range from 870 kHz. to 3.3 MHz., at an intensity up to about 3 W/cm 2 , and is applied by means of a piezoelectric transducer such as transducer 26, shown schematically in FIG. 2. The ultrasonic energy is transmitted through a thin layer 28 of a coupling agent, typically a water-based gel to the surface 30 of the skin of the patient. The skin consists of a dermis 32 and an epidennis, the latter comprising four principal layers: the basilar membrane or basal layer 34, the stratum spinosun, or spinous layer 36, the stratum granulosum or granular layer 38, and the stratum corneum or horny layer 40.
The stratum corneum 40 is typically about 10 μM thick, and consists of keratinized cells. Its water content is normally less than that of the underlying granular, spinous and basal layers, and consequently its acoustic impedance, the product of its density and the velocity of sound through it, is greater than that of the underlying layers. The density ρ of an acoustic medium has the dimensions g/cm 3 , and c, the velocity of sound in the medium, has the dimensions cm/sec. Thus, the acoustic impedance ρc has the dimensions ##EQU1##
The power reflection coefficient R at an interface between two media having acoustic impedances ρ 1 c 1 and ρ 2 c 2 is given by the equation: ##EQU2## Thus, reflection is minimized as the acoustic impedances of the two media approach each other.
While I do not wish to be bound by any particular theory, I believe that the topical application of the nicotinic acid ester solution to the patient prior to the application of ultrasonic energy increases cutaneous circulation by stimulation of the axons innervating the small papillary and subpapillary arterioles, and, as a result, causes hydration of the stratum corneum. and in the stratum comeum.
The hydration of the stratum corneum occurs very rapidly as a result of the application of the nicotinic acid ester. Hydration decreases the acoustic impedance of the stratum corneum 40 so that it approaches that of the underlying epidermal layers 38, 36 and 34, the dermal layer 32, and the coupling agent 28. Consequently, reflections 42 of the ultrasonic energy from the interface between the coupling agent 28 and the stratum corneum 40 are reduced. Likewise reflections 44 at the interface between the stratum corneum 40 and the granular layer 38 are reduced. With the reduction in reflected energy, more energy is transmitted through the epidermis and dermis to the lesion being treated. The hydration of the stratum corneum also reduces the ultrasonic attenuation of the stratum corneum.
The application of the nicotinic acid ester to the stratum corneum, both by itself, and in combination with the applied ultrasonic energy, also fluidizes the lipid interface between the keratinized proteins in the stratum corneum, and alters the spacing between the proteins. The fluidization of the lipid interface and the alteration of the spacing between proteins, also contribute to the decrease in the acoustic impedance of the stratum corneum and to the decrease in its attenuation of the ultrasonic energy.
As shown in FIG. 3, the stratum corneum comprises multiple layers (two of which are shown at 46 and 48) of keratinized proteins 50. These proteins are normally closely spaced from one another and separated by a lipid interface. Ultrasonic energy applied by a transducer 26 through a coupling agent layer 28 is both reflected and absorbed by the layers of the stratum corneum. The upwardly directed arrows signify reflected energy.
As shown in FIG. 4, which depicts the stratum corneum after having been treated by the application of a nicotinic acid ester, the lipid interface between the proteins becomes fluidized and the spacing of the proteins is altered. This fluidization of the lipid interface and the alteration of the spacing of the proteins also contributes to the decrease of the acoustic impedance of the stratum corneum and to the decrease in its attenuation coefficient. In FIG. 4, the arrows indicate that more of the ultrasonic energy is directed through the stratum corneum, and that less energy is absorbed or reflected.
In contrast, conventional gels and other coupling agents produce little hydration of the stratum corneum even after ultrasound is applied for five minutes, and have little effect on the acoustic impedance and attenuation coefficient of the stratum corneum.
The effectiveness of methyl nicotinate and ultrasonic treatment in combination was demonstrated by a study carried out on ten healthy volunteers, ranging in age from 19 to 57. Individuals having a history of vascular or skin pathology were excluded from the study.
A Moor Instruments, Inc. LDI laser Doppler image scanner was used to assess cutaneous circulation. Laser light was directed toward the skin through a glass optical fiber. A fiber-optic system was used to collect a portion of the backscattered light and direct it to a photodetector. Movement of red blood cells caused a Doppler shift in the frequency of the backscattered light. From the frequency shift, information concerning the quantity and velocity of the red blood cells was determined.
The subjects were positioned supine on a stationary table with hip and knee flexion maintained, lending support to the lower back. The procedure was carried out in two phases. With a subject positioned on the table, a baseline scan was taken of a 2×3 inch rectangular area on the anterior shoulder prior to the application of ultrasound. Ultrasound was administered at a frequency of 3.3 MHz. and a power level of 1.5 watts/cm 2 for five minutes. A repeat scan was performed immediately following treatment. On another, non-consecutive day, each subject was returned for the same procedure, on the same shoulder, preceded by a preparatory application of a 1% solution of methyl nicotinate in water.
The numbers in the following table, which represent "perfusion," correspond to the Doppler shift in the laser light as measured by the laser Doppler image scanner, and are proportional to the speed and concentration of red blood cells in the volume of tissue in which the measurement took place. The laser Doppler image scanner measures perfusion to a depth of approximately 1 mm.
______________________________________Pre treatment Post-treatment Day 1 Day 1 Day 2 Control ChangeSubject (Control) Day 2 (Control) (Swabbed) change Day 2______________________________________1 49.00 42.00 63.00 390.00 14.00 348.002 71.00 35.00 143.00 251.00 72.00 216.003 33.00 21.00 245.00 220.00 212.00 199.004 78.00 56.00 70.00 482.00 -8.00 426.005 38.00 71.00 143.00 359.00 105.00 288.006 38.00 38.00 105.00 397.00 67.00 359.007 31.00 29.00 31.00 211.00 0.00 182.008 38.00 29.00 55.00 283.00 17.00 254.009 42.00 46.00 177.00 245.00 135.00 199.0010 50.00 40.00 55.00 187.00 5.00 147.00MEAN 46.80 41.00 108.70 303.00 61.90 261.80STD 15.07 13.73 64.03 93.20 67.92 86.09______________________________________
The change in perfusion from pre-treatment to post-treatment is tabulated or each subject. The mean change in perfuision was 61.9 for the control, and 261.8 when the shoulders were swabbed with methyl nicotinate solution prior to application of the ultrasound. A paired t-test shows that there is a significant difference between the change in perfusion for the control and the change in perfusion for effected by methyl nicotinate treatment. (t=4.971, df=9, p=0.001). The study basically indicates that the combination of methyl nicotinate and ultrasound produces a much greater perfusion change than is accomplished by ultrasound alone.
The methyl nicotinate solution has also been found to be more effective than a hot pack as a preliminary to ultrasound treatment. In a study of hot pack application followed by ultrasound treatment, the mean change in perfusion was 151.20, showing that the hot pack followed by ultrasound was more effective than ultrasound alone, but substantially less effective than methyl nicotinate followed by ultrasound, the latter producing a mean change in perfusion of 261.80.
Methyl nicotinate solution can be applied, preferably by the use of a pre-packaged swab, as shown in FIG. 1, to increase the effectiveness of transdermal ultrasound, in many different situations. Specific indications include carpal tunnel syndrome, tennis elbow, medial epicondylitis (golfer's's elbow), plantar fasciitis, DeQuervain's tenosynovitis, patellar tendinitis, Achilles tendinitis, rotator cuff syndrome, low back pain, myofascial trigger points, trigger finger, hamstring tendinitis, olecranon bursitis, iliotibial-band friction syndrome, calcaneal bursitis and biceps brachii tendinitis.
The following example illustrates a specific sequence of steps carried out in a treatment in accordance with the invention.
EXAMPLE
The swab was presaturated with a solution consisting of 1% methyl nicotinate, 10% isopropyl alcohol, and 89% water.
The packaged swab was opened by tearing the package in such a way that the user's fingers could grasp the extruded tube 12 without contacting the bulb 14. This prevents the active ingredient from coming into contact with the hands. A predefined 2 inch×3 inch area of the patient's shoulder was swabbed with a up and down and side to side motion. A commercially available coupling agent, AQUASONIC 100 ultrasound transmission gel, available from Parker Laboratories, Inc. of Orange, N.J., U.S.A., was then applied to the same area, and immediately thereafter, an ultrasonic transducer was brought into contact with the area. Ultrasound at 3.3 MHz. was applied for five minutes at a level of 1.5 watts/cm 2 .
This treatment was applied to a patient with acute rotator cuff strain. As a result of a short series of treatments, the patient experienced decreased pain, increased range of motion and increased tension development.
Hyperemia, the overt measure of increased local circulation, subsides in two to three hours. Localized circulation increases the mobility of intracellular fluids to the extracellular spaces and thus accelerates metabolism. The accelerated metabolism facilitates mitotic replication of somatic cells and ultimately tissue repair. This is accomplished because the increased circulation provides the oxygenated blood necessary to catalyze the oxidative phosphorylation of ATP prerequisite to cellular repair.
The application of the methyl nicotinate solution followed by 5 minutes of ultrasound (3.3 MHZ) elevates the surface blood flow 4 to 8 times above the pre-application level. It also increases the moisture content of the skin. These effects occur within about 2 minutes after application. They last at optimum level for approximately 90 minutes and then decrease gradually over another 90 minute interval.
Methyl nicotinate is not recommended for use in facial area, and it is particularly important to avoid contact with the eyes. It is not intended for use with diagnostic ultrasound.
The procedure has applications in sports medicine. For example methyl nicotinate application followed by therapeutic ultrasound can be used to increase superficial perfusion in the pitching shoulder of a baseball pitcher prior to a game or workout. The same treatment can also be applied to the shoulders, back or knees of an ice hockey player, to the hamstring area of a football player or to the shoulders or knees of a weight lifter.
Among the advantages of the use of a nicotinic acid ester as a preliminary treatment is the fact that it acts very rapidly. Since it reaches its full effect within about two minutes, and part of that time is taken up by the application of the coupling agent, there is no need for the therapist to wait for the methyl nicotinate to take effect. Substantially immediately after the desired area of the skin is swabbed with the nicotinic acid ester, the coupling agent is applied, and the ultrasonic transducer can be applied to the patient's skin and operated.
Modifications can be made in the solution. For example, the concentration of methyl nicotinate can be varied from 0.5% to 5%. The isopropyl alcohol content can be eliminated altogether, but, if present, should be in the range from about 10% to 50%. Other alcohols, for example, ethyl alcohol, can be used instead of isopropyl alcohol. Likewise, various other additives can be included in the solution containing methyl nicotinate, and other modifications can be made to the composition of the methyl nicotinate solution and the method of its application without departing from the scope of the invention as defined in the following claims.
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Methyl nicotinate, when swabbed onto the skin prior to the application of therapeutic ultrasound, produces a surprising enhancement of the effect of the ultrasound treatment, making it possible to use less power and to apply the ultrasound over a shorter interval, and requiring no significant waiting time for the nicotinic acid ester to take effect.
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BACKGROUND OF THE INVENTION
The present invention relates to a gimballed optical system, and more particularly to a gimballed optical system combining a laser transmitter and receiver into a single system.
Lasers applied to pointing and tracking systems can provide some very desirable features, such as high spatial resolution, accurate centroid tracking, target discrimination, coding, etc. Semi-active trackers have been used, but all require a separately controlled and operated laser.
SUMMARY OF THE INVENTION
Accordingly, the present invention provides an active laser seeker with a self-contained laser so that target radiation is not required. A laser contained in the seeker provides a source of optical energy in the form of a beam which is deflected by optical elements through the hollow shafts of a gimballed system. The laser beam output is directed to be coincident with the center of the field-of-view of the gimballed system.
BRIEF DESCRIPTION OF THE DRAWING
FIG. 1 is a perspective view of the present invention illustrating the transmission path.
FIG. 2 is a cross-sectional view of the present invention illustrating the reception path.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring now to the drawing, FIG. 1 shows a two-axis gimballed optical system having a transparent dome 10, an inner gimbal 12 and an outer gimbal 14. The system is mounted on a stable platform 16. A primary objective mirror 18, such as a concave mirror, is either mounted fixedly to the stable platform, or is mounted on the inner gimbal 12 as illustrated, to act as an optical receiving mirror. A plurality of optical elements, such as prisms P1 through P8, are mounted on the system so that optical energy in the form of an optical beam from an optical emitter, such as a laser 9, is directed along the axis of the outer gimbal 14, then along the interior of the outer gimbal to the axis of the inner gimbal 12, along the axis of the inner gimbal, then to the optical axis of the system, and finally along the optical axis of the system as an output beam. An X, Y, Z-coordinate system is superimposed in FIG. 1 for ease of illustration.
The laser input beam is folded by prism P1, mounted on the stable platform 16, along the y-axis to prism P2, mounted on the inner surface of the outer gimbal 14. Prism P2 remains in optical alignment with P1 regardless of the angle through which the outer gimbal 14 is rotated. The beam is folded by P2 along the inner-surface of the outer gimbal 14 to prisms P3, P4 and P5 with P5 located on the x-axis. Prisms P3 through P5 also are mounted on the inner surface of the outer gimbal 14. Prism P5 folds the beam along the x-axis to prism P6, mounted on the inner surface of the inner gimbal 12. As with P2, prism P6 remains in optical alignment with P5 regardless of the angle through which the inner gimbal rotates. The beam is folded by prism P6 to prism P7 and P8, with P8 located on the z-axis. Prism P8 then folds the beam so that it is directed along the z-axis which is the optical axis of the system. A central housing 20 is mounted on the inner gimbal 12 by support posts 22, and the housing contains prism P8 as well as the receiver optics.
FIG. 2 shows the receiver optics for the system with an optional viewing system included. An optical quadrature detector 24, such as a photodiode with its associated preamplifier, is mounted on the rear of the housing 20 at the focal plane of the primary mirror 18 so that the detector faces the mirror. An optical bandpass filter 26 is also mounted on the housing 20 between the mirror 18 and the detector 24 adjacent to the detector to pass radiation only near and centered at the frequency of the transmitting laser. If the optional viewing system is desired, a lens with a dichoric surface coating 28 is mounted on the rear of the housing 20 so that the received laser energy passes through the dichroic to the quadrature detector 24, but other frequencies are reflected to the viewing sensor 30 via a lens 32 and mirror 34 assembly, the lens being located in a central hole through the primary mirror 18. The viewing sensor 30 could be a TV tube, a charge coupled device (CCD), a charge injection device (CID), a monolithic focal plane array (MFPA), or the like.
The prisms used are total internal reflecting prisms, and are preferred over mirrors or fiber-optic bundles since they are easier to mount, minimize polarization effects, permit optical alignment with a visible CW laser and have high coupling coefficients with no erection torques. The input prism P1 and the output prism P8 may be provided with adjustable mounts to permit alignment capability. Also, some degree of output beam divergenece control is possible by adding a small lens element on each side of the output prism P8, or anywhere else it is convenient for this collimator lens pair, such as external to the output prism shown at 21 but inside the dome 10. Finally, the laser path from the laser input to the output prism P8 may be optically shielded, as by lens mount 22, for example, to prevent stray laser radiation.
In operation a laser provides an optical beam which is deflected by the prisms P1 through P8 through the hollow shafts of the gimbals 12 and 14 to the system optical axis, and then along the optical axis through the dome 10. A small portion of the beam is then reflected by a target and returns to the system, passing through the dome 10 to reflect from the primary mirror 18 onto the optical quadnature detector 24, where it is converted into electrical energy for processing by the system electronics to provide, for example, position and range information. A portion of the received energy may be reflected from the dichroic-lens assembly 28 via a lens 32 and mirror 34 assembly to a viewing sensor 30 to provide the operator with a viewing system. The instantaneous field-of-view is determined by the detector 24, and for a photodiode it is typically 4° depending upon the photodiode diameter. Gimbal movement is typically ±55° around both axes, depending upon the gimbal limits.
Thus, the system can scan for a target, and then lock onto and follow the target once found. The operator, by means of the viewing system, can make a determination whether to stay with the target located, or whether to search for another target. Very small boresight errors are maintained with this system, resulting in improved performance. Since only a single optical system is used, there also are resultant reductions in space, cost and complexity.
The present invention may be applied to any gimbal system, free gyro stabilized or rate-aided stabilized, with only the geometry and optical/mechanical hardware differing. Besides application to missile guidance, the system may be used for stabilized airborne laser illumination, ground based or airborne laser radar, and the like. Obviously many other modifications and variations of the present invention are possible in light of the above teachings. It is therefore to be understood that, within the scope of the appended claims, the invention may be practiced otherwise than as specifically described.
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A gimballed active optical system for pointing and tracking having a laseream output which coincides with the gimbal system instantaneous field-of-view over wide angles to produce an active laser seeker.
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FIELD OF THE INVENTION
The present invention relates to a fixation device for a bone fracture.
BACKGROUND OF THE INVENTION
A fixation device according to the species is already known from DE 41 13 083 A1. This fixation device has three or four rings as clamping jaws, said rings being designed as either closed or sector rings. The rings are connected with one another by rods. For mutual positioning of the rings, the rods are axially displaceable and pivotable with respect to the rings and can be clamped in position respective to the rings. Holders are provided on the rings for bone wires or bone fixation and retaining pins.
The known fixation device permits free relative movement of the rings in space so that the bone fragments can be positioned and repositioned very exactly. The fixation device is secured in a stable fashion in precisely set positions by clamping the rods to the rings.
A fixation device is known from DE 94 01 291 U that has only two clamping jaws for provisional emergency care of the patient, with each sector ring having two holders for the clamping pins and with each holder having at least two receptacles for the clamping pins, i.e. the fixation and retaining pins, said receptacles being offset with respect to one another perpendicularly with respect to the plane of the sector ring. The clamping pins are designed as cylindrical pins that have a small point at their anterior ends, said point being capable of being pressed superficially into the bone. These clamping pins are provided with an external thread in their rear areas. After the clamping jaws are positioned, the clamping pins are then advanced by the suitably designed receptacle that cooperates with the external threads of the clamping pins until they rest on the surface of the bone and provide the necessary grip. This fixation of the clamping pins is cumbersome and time-consuming.
SUMMARY OF THE INVENTION
An object of the present invention therefore is to improve a fixation device according to the species in such fashion that positioning and fixation of the fixation device on the bone are considerably simplified.
This object is achieved according to the invention with a fixation device with clamping jaws having rods connecting the clamping jaws, the rods being adjustable axially and angularly relative to the clamping jaws and clampable in a desired position. The fixation device includes a fixation pin applicator releasably connectable with the clamping jaws for bringing a fixation pin into a desired position.
The fixation device offers a minimally invasive alternative to surgery of fractures of the tibia. The individual fragments are secured in the area of the cortex in each instance without the medullary cavity being opened (so-called pinless nail method). The fixation device can be applied rapidly and simply because of the fixation pin applicator provided according to the invention, and permits intraoperative and postoperative repositioning in all planes. This technique avoids contamination of the medullary cavity. A direct procedural change to marrow nailing poses no risk, i.e., it can be performed without an increased risk of infection. In addition, when the fixation device according to the invention is used, the device can remain in place even during marrow nailing, considerably simplifying marrow nailing and also allowing the procedure to be performed more rapidly.
Advantageous embodiments of the present invention include that the fixation pin applicator can be designed in the form of a pistol, and can have in addition to a fixed handle, a movable handle part by which a plunger acting on the fixation pin can be displaced.
In the retaining pin applicator, a transport plate for moving the plunger against the force of a spring can be moved by the movable handle part. The plunger and therefore the retaining pin is thus moved toward the desired position by this transport plate.
The fixation pin applicator can be secured to the clamping jaw by a latching mechanism in an especially simple fashion. To release the latching mechanism, the fixation pin applicator has an externally operable release that is connected by a rod with the latching mechanism.
The fixation device can include of two clamping jaws that can be brought into the desired position with respect to one another by corresponding rods. According to one advantageous embodiment of the present invention, however, additional connecting elements can be linked to the clamping jaws, said elements having suitable clamping devices to receive additional rods and hence to connect additional clamping jaws. The fixation device can thus be expanded as desired.
The fixation and retaining pins can have different shapes. Thus, they can be made straight or bent at an angle as single pins. They can also be designed as so-called dual pins, forked pins located parallel to one another. Fixation pins can also be made spoon-shaped at their ends and provided with a plurality of points parallel to one another, and here as well they can be in the form of single or dual pins.
BRIEF DESCRIPTION OF THE DRAWINGS
Further details and advantages of the invention will now be described in greater detail with reference to an embodiment shown in the drawing.
FIG. 1 is an axial plan view of the fixation device with the fixation pin applicator in place, and
FIG. 2 is a view as in FIG. 1, with the fixation pin applicator shown in another operating position.
FIG. 3 is a perspective view of the fixation device clamping jaw of FIG. 1 with an additional clamping jaw.
DETAILED DESCRIPTION
The fixation device has a plurality of clamping jaws shown in FIG. 3, with only one such clamping jaw 10 being shown in FIGS. 1 and 2. Clamping jaws 10 in this case are formed from straight sections bent at an angle with respect to one another, but can also be formed of sector rings. Clamping jaws 10 are connected by axial rods, shown in FIG. 3. The axial rods are axially displaceable in the clamping jaws and can be pivoted relative to the plane of clamping jaws 10. As a result, free three-dimensional adjustment of clamping jaws 10 relative to one another is possible. In a given desired position, the rods can be clamped in clamping jaws 10 both axially and in their pivoted position. As a result, clamping jaws 10 are connected in stable fashion with one another in their mutual positions in space.
Clamping jaws 10 have two clamping receptacles 12 to receive rods, rods 50, shown in FIG. 3. Clamping receptacles 12 are equipped with clamping balls as described in greater detail in DE 94 02 291 U and DE 41 13 083 A, incorporated herein by reference in their entirety.
As shown and described in the drawings and text of the German '083 patent, the clamping balls have a passage that extends diametrically across the ball, and is designed to receive an axial rod. The clamping balls also have slots cut on their surface, along meridian lines. These slots allow the clamping ball to contract radially by a small amount when squeezed, so that the diameter of the passage is reduced. The specific configuration of the clamping balls is not important, as long as they allow a reduction in diameter of the passage when the clamping ball is squeezed.
The connection between the axial rods and the clamping jaw of the present invention can be fixed in a desired position by pressing a clamping plate against the jaw. This is achieved by tightening screws that hold the clamping plate to the jaw, so that movement of the rods in all axes is stopped.
The slotted balls can pivot, for example, between spherical or conical bearing surfaces. By tightening the clamping plate against the jaw, the bearing friction between the slotted balls and the bearing surfaces can be adjusted, to impede or completely prevent motion of the balls. The tightening of the clamping plate also immobilizes the rod placed in the passage of the axial balls, by reducing the diameter of the passage through the balls. The rods are thus prevented from translating and from rotating relative to the jaw.
In operation, the axial rods 50 shown in FIG. 3 are inserted in passages of the clamping balls, while the screws attaching the clamping plate to the clamping jaw are loose. Once the clamping jaw 10 is in the proper position relative to the rod, the screws are tightened, preventing further rotation of the clamping balls, and translation of the axial rods within the passage.
A retaining pin 14 can be inserted at one end of clamping jaw 10, perpendicularly to clamping jaw 10. This retaining pin 14, as shown in the embodiment illustrated here, can be designed as a so-called double-spoon pin. For this purpose, retaining pin 14 is bent at its free end so that it is spoon-shaped in cross section and has a plurality of points 16 that serve for fixation in the cortex of a tibia 18 for example.
At the opposite free end of clamping jaw 10, a fixation pin 20 is guided in an axially displaceable manner in the direction a indicated by the double arrow. For axial displaceability of fixation pin 20, in other words for positioning said pin in the cortex of tibia 18, a fixation pin applicator 22 is connected securely but releasably by a latching mechanism 24 with clamping jaw 10.
Fixation pin 20 can be positioned rapidly and simply at the desired location using fixation pin applicator 22. After fixation pin 20 has been positioned, in other words after point 26 of fixation pin 20 has engaged the cortex, said pin being V-shaped for example, fixation pin 20 is secured to the clamping jaw in any known manner that allows the two components to be connected and then released as needed. After fixation pin 20 has been secured to the clamping jaw, fixation pin applicator 22 is released from clamping jaw 10.
Fixation pin applicator 22 is designed in the shape of a pistol and has a fixed handle 28 and a housing 30 that resembles a pistol barrel. A plunger 32 is located in housing 30, said plunger being axially displaceable in the direction b indicated by the double arrow, said plunger acting on the fixation pin inserted into fixation pin applicator 22. Plunger 32 is displaceable by means of a transport plate 34. This transport plate is impacted upon by a movable handle part 36 as the movable handle part is pivoted in the direction c indicated by the double arrow. This kinematic arrangement is apparent from a comparison of FIG. 1 showing handle part 36 in its initial position and FIG. 2 showing the handle part in its pivoted position.
A release lever 38 is also mounted on fixation pin applicator 22, said lever being connected by a rod 40 with latching mechanism 24. The fixation pin applicator can be released in simple fashion from clamping jaw 10 by actuating release lever 38.
The fixation device according to the invention can be used as follows: first, clamping jaws 10 are fitted with the selected retaining pin 14. Then the fixation pin applicator is connected to the clamping jaw, with a selected fixation pin 20 being inserted. This clamping jaw, provided with pins 14 and 20, is placed over the portion of tibia 18 where implantation is to occur and the apparent perforations in the skin are marked. A lengthwise incision approximately 8 to 10 mm long is made in the skin with a scalpel, the soft tissues are scraped away using a raspatory, and the bone is exposed down to the periosteum. Then the selected fixation and retaining pins 20 and 14, together with fixation pin applicator 22 and clamping jaw 10, are introduced into the soft tissues, ideally between the bone and the raspatory, until retaining pin 14 gains a sufficient grip in the vicinity of the rear edge of the tibia. Then fixation pin 20 is introduced by means of fixation pin applicator 22 through the prepared skin incision in the area of the forward edge of the tibia until proper bone contact is achieved. The implants are finally fixed in place by multiple actuation of handle 36. A sufficient grip of clamping jaw 10 is obtained when the injured extremity can be lifted at the clamping jaw from the support without the pins tearing loose. In the same fashion, the fragment opposite the fracture is secured with one or two clamping jaws 10.
When dual pins are used, it is sufficient to connect the clamping jaws located proximally and distally with respect to the fracture by means of sufficiently long rods. The fracture is repositioned for example while being viewed on an x-ray image converter. As soon as the axes of the fragments have been aligned, final fixation of the rods is performed.
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A fixation device with clamping jaws with rods connecting the clamping jaws, said rods being adjustable axially and angularly for positioning relative to the clamping jaws and clampable in the desired position, and with fixation and retaining pins that are receivable in a clampable fashion in the clamping jaws. According to the present invention, a fixation pin applicator can be connected in a releasable fashion. A fixation pin can be brought into a desired position using of the fixation pin.
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BACKGROUND OF THE INVENTION
The present invention relates to a focus adjusting mechanism for use in a device having variable magnification means, and more particularly to a focus adjusting mechanism for use with variable magnifiction means such as a plurality of projecting lenses of varying focal lengths, and adapted for use in reader-printers and like apparatus.
Microfiche films, one type of microfilms, are used at various reduced scales (microfilming reduction ratios) generally for recording literature, papers and documents. The recorded images carried on microfiche films are viewed or copied with the use of reader-printers which, if equipped with a single projecting lens of definite focal length, will involve a limitation on the size of projectable enlarged images.
Accordingly, conventional reader-printers may be provided with a plurality of projecting lenses of varying focal lengths, one of which will be selectively positioned in an operative position to give the desired magnification in accordance with a particular microfiche film. These lenses, however, require a space for storage, are not easily and quickly changed and must be focused every time the lenses are changed.
To overcome these drawbacks, an apparatus has been proposed and placed into use as disclosed in U.S. Pat. No. 3,713,737. The disclosed apparatus comprises a plurality of projecting lenses having varying focal lengths and a support plate carrying the lenses together and movable to bring the desired projecting lens to a projecting position. With the movement of the support plate, the focusing ring on the selected lens comes into engagement with a single focusing dial fixedly provided in the vicinity of the projecting position so that the lens can be focused by the dial. Although the apparatus has found wide use because of its outstanding usefulness, the apparatus still remains to be improved in respect of the following drawback.
With the apparatus described, the change of the projecting lenses involves disengagement and engagement between the focusing ring of the lens and the focusing dial. This could permit a small amount of rotation of the focusing ring entirely independently of focusing adjustment. This phenomenon will be described below in greater detail. When the focusing ring on a lens moves with the support plate relative to the focusing dial, the ring has not been completely disengaged from the dial means in the initial stage of the relative movement, with the result that this movement entails slight rotation of the ring and the dial means. This phenomenon also takes place when the focusing ring in a disengaged position comes into engagement with the dial means. This gives rise to a serious objection, for example, when a projecting lens, once focused, is shifted to a non-projecting position and thereafter returned to the projecting position again, because each shift of the lens to the non-projecting position and then back to the projecting position causes rotation of the focusing ring on the lens, thereby bringing the lens out of focus and necessitating focus adjustment again.
To overcome the above drawback, Published Unexamined Japanese Utility Model Application No. 51/52252 proposes an expedient in which the objectionable rotation of the focusing ring of the lens is precluded by rendering the focus adjusting dial means less resistant to rotation than the focusing ring. Although the objectionable rotation of the focusing ring can be prevented to some extent according to the proposal, the drawback still remains to be fully eliminated, consequently entailing the frequent necessity of refocusing during use.
For reference, the focus adjustment of projecting lenses for reader-printers will be described specifically with numerical values. The projecting lenses usually used have a magnification of about 10 to about 50X. Thus, even the slightest shift in the focus of the lens will produce blurred enlarged images upon projection. It has been found that the projecting lens, when shifted about 0.02 mm from its focused position, produces blurred images which can be detected with the unaided eye. Calculated as the angular displacement of the focusing ring of the lens, such amount of shift corresponds to as small as about 3 to about 4 deg.
SUMMARY OF THE INVENTION
The main object of the present invention is to provide a novel and useful focus adjusting mechanism for use in devices having variable magnification means.
Another object of this invention is to provide a focus adjusting mechanism which is adapted for use in a device having variable magnification means and which overcomes the foregoing drawbacks of conventional devices.
Another object of this invention is to provide a focus adjusting mechanism for use in devices having variable magnification means such as projecting lenses with focusing rings which are not rotatable except by a focusing action.
Another object of this invention is to provide a focus adjusting mechanism for use in devices with variable magnification means which has a high degree of operability.
Another object of this invention is to provide a focus adjusting mechanism which is particularly suited to microfilm or microfiche readers or microfilm or microfiche reader-printers.
These and other objects of the present invention can be accomplished by providing a focus adjusting mechanism for use with variable magnification means in which the means for focusing the magnification means can be shifted to a nonoperating position relative to a projecting lens before changing the projecting lens.
More specifically, the objects of the invention are accomplished by providing a focus adjusting mechanism which includes a support fixedly carrying a plurality of projecting lenses and movable for selectively bringing one of the projecting lenses to a projecting position, focus adjusting first means shiftable between an operating position and a nonoperating position, second means biasing the focus adjusting means toward the operating position for rendering a projecting lens adjustable by the focus adjusting first means when the lens is positioned in the projecting position, and third means for shifting the focus adjusting means to the nonoperating position against the action of the second means to permit changing the lenses.
The focus adjusting mechanism has further features.
First, the focus adjusting mechanism includes a lever for moving the support. The lever is shiftable relative to the support at least between a first position and a second position.
Second, the third means is connected by coupling means to the lever for moving the support and is movable by the shift of the lever to the second position to shift the focus adjusting means.
Third, the shift of the lever to the second position renders the support movable by the lever.
Fourth, the focus adjusting mechanism includes means for biasing the lever toward the first position.
These and other objects, advantages and features of the invention will become apparent from the following description thereof when read in conjunction with the accompanying drawings which illustrate exemplary embodiments of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
In the drawings:
FIG. 1 is a perspective view showing a reader-printer in which a focus adjusting mechanism according to the present invention is used for its variable magnification means;
FIG. 2 is a diagram schematically showing the interior construction of the reader-printer illustrated in FIG. 1;
FIG. 3 is an enlarged perspective view showing the focus adjusting mechanism used in the reader-printer;
FIG. 4 is a perspective view showing another embodiment of the focus adjusting mechanism according to the present invention and adapted for use with variable magnification means; and
FIG. 5 is a view partly in section showing the embodiment of FIG. 4.
In the following description, like parts are designated by like reference numbers throughout the several views of the attached drawings.
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the focus adjusting mechanism of this invention for variable magnification devices will be described below with reference to the accompanying drawings which show the invention as incorporated in a reader-printer for illustrative purposes.
FIGS. 1 and 2 show the reader-printer in its entirety. A microfiche film (not shown) is held in a planar position by a carrier 3 supported on a frame 2 of the main body 1 of the reader-printer. The carrier 3 is movable toward the front or rear and also sidewise. The film is illuminated by a light source 10 through a group of condenser lenses 11. An enlarged image of that portion of the film which is illuminated is projected by a projecting lens 40 and mirrors 13, 14 and 15 onto a screen 17, provided on the front side of the main body 1.
The carrier 3 has upper and lower glass plates (not shown) for holding the microfiche film therebetween. For a copying operation, the mirror 15 is movable about a pivot 16 to the position indicated in two-dot-and-dash lines in FIG. 2.
A roll of photosensitive paper 18 is supported on a spool 19. Arranged along the path of transport of the photosensitive paper are a pair of feed rollers 20, a cutter 21, a pair of transport rollers 22a, a charger 23, a press roller 24, a suction belt 25 and a suction unit 26. The photosensitive paper 18 is exposed at an exposure station 27 provided by the suction belt 25 in a planar form under the action of the suction unit 26. The path of transport of the paper extending from the exposure station 27 is provided with a pair of transport rollers 22b, a developing unit 28, a pair of squeeze rollers 32 and a pair of dehumidifying rollers 33. The developing unit 28 includes a tank 29 filled with a developer, lower electrode rollers 30 partly immersed in the developer and upper electrode rollers 31 disposed above the rollers 30.
Provided on the front side of the main body 1 are copying switch 34, an exposure adjusting knob 35, a copy number setting dial 36, a paper size changing switch 37, and other control elements.
The focus adjusting mechanism of this invention will be described in greater detail with reference to FIG. 3.
FIG. 3 shows the interior construction of the projecting lens unit 50 of the reader-printer shown in FIG. 1. The unit 50 includes a projecting lens changing lever 47 and a focusing dial 64, both of which are partially exposed to outside so as to be operable from outside. Unit 50 has two lenses, namely first and second projecting lenses 40a and 40b, having different focal lengths.
The focusing dial 64 is rotatably mounted on a shaft 65 fixed to one end of a lever 73. Lever 73 is pivotably supported by a pivot 70 and is biased by a spring 71 in the direction of an illustrated arrow A into contact at its side edge with a positioning pin 72. FIG. 3 shows the first projecting lens 40a in the projecting position. When the lens 40a is thus positioned, the focusing dial 64 is in its operating position with its outer periphery held in engagement with a focusing ring 41a on the first projecting lens 40a by the force of the spring 71. The focusing dial 64, when operated by rotation, causes rotation of ring 41a to cause focus adjustment of the lens 40a in the projecting position.
The lens changing lever 47 is pivotably mounted on a lever shaft 48 which is fixed to a projecting lens support plate 80. Plate 80 supports the first and second lenses 40a and 40b and is movable in the directions of arrows B by guide rollers 81a, 81b, 81c and 81d rotatably mounted on the main body. The support plate 80 is provided with magnets 82a and 82b at its opposite side ends. When the first lens 40a is in the projecting position, the magnet 82a and a magnetic block 83a fixed to the main body attract each other, holding the support 80 in the illustrated position. When the second lens 40b is in the projecting position, the magnet 82b and a magnetic block 83b will magnetically attract each other. The support plate 80 is provided with a microswitch actuating member 84 which selectively turns on or off microswitches 85 and 86 mounted on the main body. Switches 85 and 86 feed an electric signal to an electric circuit in the reader-printer main body to indicate which of the lenses is in the projecting position. The electric signal can be utilized by the circuit, for example, for adjusting the amount of exposure of the photosensitive paper in accordance with the magnification of the selected lens.
The lens changing lever 47 is associated with an intermediate plate 90 fixed to the support plate 80 by posts 87 and 88. By springs 94 and 95 a link plate 93 is connected to the intermediate plate 90 which is fixedly provided with pins 91 and 92 engaging in slots formed in the link plate 93. Springs 91 and 92 have equal biasing force and act to retain the link plate 93 in the illustrated neutral position. A pin 96 is fixedly provided at the midpoint of link plate 93 and engages in a slot formed in the lens changing lever 47.
The link plate 93 is formed with a cam face on one side thereof in contact with a portion of the dial shaft 65. The cam face is so shaped that only when the link plate 93 is in its neutral position as shown, a recessed portion of the cam face is in contact with a portion of the dial shaft 65, thereby allowing the focusing dial 64 to be in its operating position. When the link plate 93 is brought out of its neutral position, that portion of the dial shaft 65 comes into contact with a projection of the cam face, thereby moving the lever 73 in the direction opposite to the arrow A against the action of the spring 71 and consequently causes the focusing dial 64 to be moved to its nonoperating position.
The operation of the focus adjusting mechanism of this invention will now be described.
First, the second projecting lens 40b in the position shown in FIG. 3 will be shifted to the projecting position in place of the first lens 40a in the following manner. When changing the lens, the operator holds the lens changing lever 47 and moves the lever in the direction of an arrow C shown. In the initial stage of this movement, the lever 47 pivotally moves about the lever pivot 48 slightly since the support plate 80 is held in the illustrated position by the magnetic attraction between the magnet 82a and the magnetic block 83a. The pin 96 causes the link plate 93 to also move in the direction of arrow C, following the lever 47. Although not described, the force of the springs 94 and 95 and the magnetic attraction between the magnets 82a, 82b and the magnetic blocks 83a, 83b are so determined as to permit such a movement.
The movement of the link plate 93 causes the pins 91 and 92 fixed to the intermediate plate 90 to bear against the link plate 93 toward one end of the plate 93. In this state, the lever 47 is held to the support plate 80 against movement relative thereto only in the direction of the arrow C, at the two points of the pivot 48 and the pin 96. Accordingly, when moved further in the direction of the arrow C, the lens changing lever 47 causes the support plate 80 also to follow the movement of the lever 47 in this direction against the magnetic attraction between the magnet 82a and the magnetic block 83a.
Before movement of the support plate 80 occurs, an important action takes place when the link plate 93 starts to follow the lens changing lever 47. When the link plate 93 moves in the direction of the arrow C from its neutral position, the dial shaft 65 in contact with the recessed portion of the cam face of the plate 93 comes into contact with the projection of the cam face, causing the lever 73 to pivot in the direction opposite to arrow A against the action of the spring 71. This moves the focusing dial 64 in the direction opposite to arrow A from its operating position in which it is in engagement with the focusing ring 41a of the first lens 40a, thus bringing the dial 64 to a nonoperating position out of engagement with the ring 41a. This movement is followed by the aforementioned movement of the support plate 80, so that even when the focusing ring 41a moves relative to the focusing dial 64 on the main body for the change of lens, the ring and the dial, which are completely out of engagement with each other, will not affect each other and cause focusing movement of the lens 40a.
As the support plate 80 moves in the direction of the arrow C with the movement of the lens changing lever 47, the dial shaft 65 sliding on the projection of the cam face of the link plate 93 comes into another recessed portion of the cam face closer to the lens 40b, allowing the focusing dial 64 to move in the direction of arrow A. At this time, however, the projecting lens 40b has not reached the projecting position, and the dial 64 will not engage the ring 41b of the lens 40b.
When the support plate 80 further moves in the direction of arrow C, the dial shaft 65 temporarily engaging in the recessed portion of the cam face rides onto another projection of the cam face. The support plate 80 slightly moves in the same direction in this state to bring the second projecting lens 40b to the projecting position, whereupon the actuating member 84 operates the microswitches 85 and 86, which in turn feed to the main body electric circuit an electric signal indicating that the second lens 40b has reached the projecting position. The magnet 82b and the magnetic block 83b now magnetically attract each other and lock the lens 40b to the projecting position. Thus the lens is completely installed in place. On completing the change of lenses, the operator releases the lens changing lever 47 from the hand to free the lever 47 from the force which has been acting thereon in the direction of the arrow C, whereupon the link plate 93 returns in the direction opposite to arrow C to its neutral position under the action of the springs 94 and 95. At this time, the lens changing lever 47 also moves in the same direction by a small amount. As a result, the dial shaft 65 riding on the projection of the cam face of the link plate 93 engages in the recessed portion to shift the focusing dial 64 in the direction of arrow A to the operating position. With the second lens 40b already brought to the projecting position at this time, the focusing dial 64 properly comes into engagement with the focusing ring 41b. Consequently the second lens 40b can be focused by turning the dial 64 from outside.
If the focusing dial 64 is likely to contact the focusing rings 41a, 41b when temporarily shifted to its operating position during the foregoing lens changing movement, means may be provided for preventing the shift of the dial to the operating position while the lenses 40a, 40b are not in the projecting position. More specifically, the intermediate plate 90 may be formed with a cam face adapted for contact with the dial shaft 65 fulfilling the requirements described above.
In order to move lens 40a into the operating position in place of lens 40b, lever 47 will be moved in the direction opposite to arrow C, but the mechanism operates basically in the same manner as described above, so this changing operation will not be described.
As will be apparent from the above description, the mechanism of this invention assures focus adjustment with ease and does not involve the focal movement of the projecting lens due to contact with the focusing means every time the lens is changed, thus eliminating the necessity of readjustment of the lens once it has been focused despite the replacement of the lens.
Another embodiment of the focus adjusting mechanism of this invention will be described below with reference to FIGS. 4 and 5.
FIG. 4 is a perspective view showing a modification of the projecting lens unit 50 illustrated in FIG. 3. The modified parts are designated by reference numerals over 100 and will be described below, while the same parts as in FIG. 3 are indicated by the same reference numerals and will not be described.
A lens changing lever 101, which is substantially T-shaped, is supported by an intermediate plate 103 and slidable in the direction of an arrow D. The intermediate plate 103 is fixed to the support plate 80. The upper bar portion 102 of the T-shaped lever 101 is formed at its opposite ends with slots 102', in which pins 104 and 105 fixed to the plate 103 are inserted respectively, while a pin 107 fixed to the lever 101 extends through a slot 103' formed in the intermediate plate 103. A spring 108 extending from the pin 107 to a pin 106 on the intermediate plate 103 biases the lens changing lever 101 toward the direction opposite to arrow D at all times.
A pin 109 projects downward from the lever 101 and is held by the action of the spring 108 in contact with one side of a lever positioning plate 110 attached to the main body and having recesses 111 and 112 in that side. The lever 101 is held in position with respect to the direction of the arrow D and relative to the intermediate plate 103, by the contact between the pin 109 and the plate 110. The recesses 111 and 112 are so located that the pin 109 is engageable therein when the first and second projecting lenses 40a and 40b are in the projecting position respectively.
The upper bar portion 102 of the T-shaped lever 101 is provided with a bent portion (see FIG. 5) for contact with the dial shaft 65. When the lever 101 is moved in the direction of the arrow D, the bent portion moves the dial shaft 65 in the direction opposite to the arrow A shown, consequently bringing the focusing dial 64 out of engagement with the focusing ring 41a or 41b of the lens. While the pin 109 is in engagement with the side recessed portion 111 or 112 of the positioning plate 110, the focusing dial 64 is in engagement with the focusing ring 41a or 41b on the corresponding lens.
Briefly this embodiment operates in the following manner when shifting the second projecting lens 40b in the position of FIG. 4 to the projecting position. The reverse lens changing procedure will not be described.
The operator holds the lens changing lever 101 and moves the lever in the direction of the arrow D. This movement shifts the focusing dial 64 in the direction opposite to arrow A out of engagement with the focusing ring 41a of the lens 40a, thus shifting the dial 64 to a non-operating position. At the same time, the pin 109 moves out of the side recess 111 of the positioning plate 110 to render the changing lever 101 movable in the direction of an arrow E in FIG. 4.
When the lever 101 is moved in the direction of the arrow E, the support plate 80 also moves with the lever 101, bringing the lens 40b to the projecting position. The pin 109 which opposes the side recess 112 of the positioning plate 110 at this time engages in the recess 112, with the result that the dial 64 which has been in its nonoperating position shifts to the operating position into engagement with the focusing ring 41b of the lens 40b. Consequently the lens 40b can be focused by the focusing dial 64. The pin 109 and the recess 112 provide a click stop to hold the projecting lens 40b in the projecting position.
Although the present invention has been fully described by way of example with reference to the accompanying drawings, it is to be noted that various changes and modifications will be apparent to those skilled in the art. Therefore, unless otherwise such changes and modifications depart from the scope of the present invention, they should be construed as included therein.
For instance, whereas the embodiments of the focus adjusting mechanism of this invention described are adapted for use in a variable magnification device employing two lenses, the invention is similarly useful for variable magnification devices in which more than two lenses are used.
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In an optical system including a plurality of projecting lenses mounted on a support plate and selectively usable by moving the support plate for projecting copy images at varying magnifications, a focus adjusting mechanism includes focus adjusting first means shiftable between an operating position and a nonoperating position, second means biasing the focus adjusting means toward the operating position for rendering a projecting lens adjustable by the focus adjusting means when the lens is positioned in the projecting position, and third means for shifting the focus adjusting means to the nonoperating position against the action of the second means to permit changing the lenses.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to variant aequorin genes and a process for producing variant aequorin proteins. More particularly it relates to variant aequorin genes prepared according to a site-specific mutagenesis method using a synthetic oligonucleotide, and a process for producing the above-mentioned proteins by the use of the above-mentioned genes.
2. Description of the Related Art
Aequorin existent in nature is the so-called photoprotein separated from photogenic Aequorea living in the sea, followed by separation and purification, and has been known as a biologically active substance in living body having a high utility value. Namely, since aequorin emits light by way of metal ions such as Ca 2+ , Sr 2+ , etc., it is utilized as a reagent for detecting trace Ca 2+ (10 -9 M), and in particular, it has been confirmed to be effective for measuring intercellular Ca 2+ . However, its production quantity is extremely small so that it is the present status that the quantity is insufficient even as an agent for research.
Thus, firstly the present inventors separated cDNA gene from photogenic Aequorea, identified it and referred to it as pAQ440 (Japanese patent application laid-open No. Sho 61-135586/1986). Further, we succeeded in producing aequorin protein inside Escherichia coli by means of recombinant DNA technique (Japanese patent application No. Sho 60-280259/1985), and also disclosed that it is possible to detect metal ions such as Ca 2+ by making use of this aequorin protein (Japanese patent application No. Sho 61-103849/1986).
However, as to its photogenic mechanism, many unclarified points are still present. Elucidation of the photogenic mechanism of aequorin protein and its correct understanding will extend a possibility of concrete applications of aequorin protein. More particularly, understanding of aequorin as a functional protein having a utility in the aspect of structure and function of protein will be linked to elucidation of the photogenic mechanism of aequorin and also will have a profound meaning in the aspect of protein engineering and further a commercial utilization value.
In view of the technical situation relative to aequorin protein, the present inventors have prepared variants of natural type aequorin gene (pAQ440) by means of recombinant DNA technique, and have succeeded in producing variant aequorin genes inside Escherichia coli by making use of the above genes. Further, by comparing the structure and function of these variant aequorin genes with those of pAQ440, it has become possible to more profoundly analyze the photogenic mechanism of the latter pAQ440.
As apparent from the foregoing, the object of the present invention is to provide many kinds of specified variant aequorin genes useful for making the above-mentioned analysis possible, and a process for producing variant aequorin proteins by the use of the above variant aequorin genes.
Further, as described above, as to the photogenic mechanism, the present inventors have analyzed the structure and function of the aequorin gene according to the site-specific mutagenesis method (Japanese patent application Nos. Sho 61-245108/1986 and Sho 61-245109/1986).
However, during the regeneration process of aequorin wherein aequorin which is light-emissive due to calcium is reconstructed in the presence of apoaequorin, coelenterazine as a substrate, molecular form oxygen and 2-mercaptoethanol as a reducing agent, it has been known that 2-mercaptoethanol is necessary to be in a high concentration. The reason why 2-mercaptoethanol is required is unclear, but a possibility of converting the --S--S--bond of aequorin protein(apoaequorin) into --SH,HS--is suggested.
Thus, it is very meaningful to produce variant aequorin proteins which do not require the presence of 2-mercaptoethanol as a reducing agent at the time of regeneration of aequorin by means of recombinant DNA technique, and this will be linked to elucidation of the regeneration mechanism of aequorin and further it will have a profound meaning in the aspect of protein engineering and also a utilization value in the scientific and commercial aspect.
In view of the above-mentioned technical situation of aequorin protein, the present inventors have prepared variants of natural type aequorin gene (pAQ440) by means of recombinant DNA technique, and have succeeded in producing variant aequorin genes inside Escherichia coli by making use of these genes.
Further, it has become possible to produce apoaequorin from which regeneration of aequorin is possible without needing the presence of 2-mercaptoethanol, using variant aequorin genes of the present invention as described later. The variant aequorin genes could have been obtained by converting G of TGC as a base arrangement which can form cysteine residual group on the aequorin gene, into C, to thereby exchange the serine residual group into the cysteine residual group in apoaequorin molecule.
SUMMARY OF THE INVENTION
The present invention resides in the following constitutions (1) to (4):
(1) In the following base arrangement of pAQ440 as aequorin gene: ##STR1## variants having converted a base or bases indicated in the following items (i) to (xiii) into other definite base or bases, or having deleted bases indicated therein:
(i) a variant having converted the 220th base G into C;
(ii) a variant having converted the 238th base G into A;
(iii) a variant having converted the 307th base C into T, and also the 308th base A into T;
(iv) a variant having converted the 499th base G into C;
(v) a variant having converted the 568th base T into C;
(vi) a variant having converted the 569th base G into C;
(vii) a variant having converted the 590th base G into C;
(viii) a variant having converted the 607th base G into C;
(ix) a variant having converted the 625th base G into A;
(x) a variant having converted the 616th base G into C, and also the 625th base G into A;
(xi) a variant having converted the 674th base G into C;
(xii) a variant having deleted the 205th to the 207th bases GAT; and
(xiii) a variant having deleted the 592nd to the 594th bases GAT.
(2) In the following base arrangement of pAQ440 as aequorin gene: ##STR2## a process for producing a variant aequorin protein which comprises using variants having converted a base or bases indicated in the following items (i) to (xiii) into other definite base or bases, or having deleted bases indicated therein:
(i) a variant having converted the 220th base G into C;
(ii) a variant having converted the 238th base G into A;
(iii) a variant having converted the 307th base C into T, and also the 308th base A into T;
(iv) a variant having converted the 499th base G into C;
(v) a variant having converted the 568th base T into C;
(vi) a variant having converted the 569th base G into C;
(vii) a variant having converted the 590th base G into C;
(viii) a variant having converted the 607th base G into C;
(ix) a variant having converted the 625th base G into A;
(x) a variant having converted the 616th base G into C, and also the 625th base G into A;
(xi) a variant having converted the 674th base G into C;
(xii) a variant having deleted the 205th to the 207th bases GAT; and
(xiii) a variant having deleted the 592nd to the 594th bases GAT.
(3) In the following base arrangement of pAQ440 as aequorin gene: ##STR3## variants having converted a base or bases indicated in the following items (i) to (iv) into other definite base or bases indicated therein:
(i) a variant having converted the 569th base G into C and the 590th base G into C;
(ii) a variant having converted the 590th G into C and the 674th G into C;
(iii) a variant having converted the 674th G into C and the 569th G into C; and
(iv) a variant having converted the 569th base G into C, the 590th base G into C and the 674th base G into C.
(4) In the following base arrangement of pAQ440 as aequorin gene: ##STR4##
a process for producing a variant aequorin protein which comprising using
variants having converted a base or bases indicated in the following items (i) to (iv) into other definite base or bases indicated therein:
(i) a variant having converted the 569th base G into C and the 590th base G into C;
(ii) a variant having converted the 590th G into C and the 674th G into C;
(iii) a variant having converted the 674th G into C and the 569th G into C; and
(iv) a variant having converted the 569th base G into C, the 590th base G into C and the 674th base G into C.
BRIEF DESCRIPTION OF THE DRAWING
The accompanying drawing shows a chart illustrating the site-specific mutagenesis method of Example 1 of the present invention.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
The variant genes of the present invention may be produced through the process as illustrated in the accompanying drawing. According to the process of the present invention, variations as mentioned later were introduced into the aequorin gene by the use of a synthetic oligonucleotide and according to a site-specific mutagenesis method. The variation process has no particular limitation, but for example, gap-duplex process (Morinaga et al, Bio/Technology, Vol. 2, 636-639 (1984) may be employed. According to the process, for example, a synthetic oligonucletide is used as a variation source as shown later in Table 1. Such a synthetic oligonucleotide may be synthesized employing a commercially available automatic DNA synthesis apparatus and its purification is preferably carried out employing a high performance liquid chromatography. The purified product is subjected to end-phosphorylation in a conventional manner to obtain a primer for preparing a plasmid.
On the other hand, an Eco RI-Hind III fragment and an Aat II fragment of a plasmid pAQ440 shown in the accompanying drawing are used and the Aat II fragment is subjected to dephosphorylation treatment in a conventional manner.
The two fragments based on pAQ440, obtained as above, together with the above-mentioned end-phosphorylated primer are, for example, subjected to three-stage treatment (treatment at definite temperatures and for definite times) to carry out annealing. The three stages refer to a combination consisting of an order of e.g. (100° C., 5 minutes), (30° C., 30 minutes) and (4° C., 30 minutes).
Next, with the resulting variant pAQ gene, transformation into E. coli is carried out as follows:
For example, dXTP (X=G.A.T.C.) obtained as above and Klenow fragment (E. coli polymerase) are reacted in the presence of T 4 -ligase to prepare a duplex chain. The thus formed plasmid duplex chain is transformed into E. coli in a conventional manner. Further, the variant plasmid (variant of pAQ440) is screened using the above-mentioned respective variant source primers as probes, according to colony hybridization. The identification method of the variant has no particular limitation, but the base arrangement is determined e.g. according to dideoxy method (Hattori et al, Anal. Biochem. 152, 232-238, 1986) to detect the variant base.
Next, in the present invention (the invention of production process), production of aequorin protein inside Escherichia coli is carried out using the above-mentioned variant aequorin gene.
Namely, the outline of the production is as follows:
the cDNA fragment of Hind III-Eco RI of the variant pAQ440 gene is subjected to cloning into the Hind III-Eco RI part of the plasmid pUC9-2 having a promoter of lac; the resulting plasmid is transformed into Escherichia coli such as HB101 (D1210i Q ) strain; and using the resulting Escherichia coli and an expression derivative such as IPTG, an aequorin protein is produced inside Escherichia coli.
The production process and the bacterial bodies-collecting process are carried out in a conventional manner. The collected bacterial bodies are dissolved in a suitable known buffer solution, followed by breaking the bacterial bodies in a conventional manner such as ultrasonic wave treatment and obtaining the supernatant by means of centrifugal treatment to use it as an enzymatic solution for measurement.
The method for measuring the luminescence relative to this solution is carried out as follows:
With a definite quantity of the solution are mixed a substrate (coelenterazine) and a reducing agent (2-mercaptoethanol) each in a definite quantity in the case of the above-mentioned inventions (1) and (2), while with the definite quantity of the solution is not mixed 2-mercaptomethanol in the case of the above-mentioned inventions (3) and (4), followed by maturing the resulting respective solutions under ice-cooling for 2 or 3 hours, transferring the resulting solutions into a reaction cell inside a phototube measurement apparatus, further injecting a definite quantity of CaCl 2 solution into the cell and measuring the resulting luminescence.
The synthetic oligonucleotide (primer) of the above inventions (1) and (2) is shown later in Table 1 of Example 1, and the aequorin activity of the primer is shown later in Table 2. The extent to which the aequorin activity varies or is extinct depending on what a site the base arrangement of aequorin gene is varied or base(s) therein are removed at is apparent from Tables 1 and 2.
The synthetic oligonucleotide (primer) to be measured, of the above-inventions (3) and (4) is shown later in Table 3 of Example 2, and the aequorin activity of the primer is shown later in Table 4 of the Example. It is apparent from Tables 3 and 4 that aequorin is reproduced by varying the base arrangement of aequorin gene, even when no 2-mercaptoethanol is added.
In particular, in the case of Cl+2+3S wherein the cysteine residual groups at all of the three parts have been converted into serine residual groups, it is apparent that aequorin is reproduced almost completely.
The present invention will be described in more detail by way of Examples.
EXAMPLE 1
1) Introduction of mutagenesis into aequorin gene (pAQ440) according to a site-specific mutagenesis process using a synthetic oligonucleotide (see the accompanying drawing)
The site-specific mutagenesis process was carried out according to gap-duplex process of Morinaga et al (Bio/Technology, Vol. 2, 630-639 (1984)). Namely, as shown later in Table 1, a synthetic oligonucleotide was used as a variation source. As the synthetic oligonucleotide, there was used a product obtained by preparing a raw product by means of an automatic DNA synthesis apparatus manufactured by ABI Company, followed by purifying it according to high performance liquid chromatography and carrying out end-phosphorylation with T4 kinase. Eco RI-Hind III fragment and Aat II fragment of pAQ440 were used, and Aat II fragment was treated with an alkali phosphatase to carry out dephosphorylation. These two fragments together with the primer were treated at 100° C. for 5 minutes, followed by allowing the resulting material to stand at 30° C. for 3 minutes and further at 4° C. for 30 minutes to carry out annealing and reacting dXTP (X=G, A, T, C) with Klenow fragment (Escherichia coli polymerase) in the presence of T4-ligase to prepare a duplex chain.
The thus formed plasmid duplex chain was transformed into E. coli in a conventional manner, and the variant plasmid (variant of pAQ440) was screened by colony hybridization, using the respective variant source primers as probes. As to the ascertainment of the variant, the base arrangement was determined according to the dideoxy process of Hattori et al (Anal. Biochem. 152, 232-238, 1986) and the variant base was detected.
2) Production of variant aequorin protein inside E. coli by the use of various variant aequorin genes
cDNA fragment of Hind III-Eco RI of variant pAQ440 gene was subjected to cloning into the Hind III-Eco RI part of plasmid pUC9-2 having lac promoter, and transforming into E. coli HB101 (D1210i Q ) strain to produce variant aequorin protein inside E. coli by means of expression inducer IPTG.
Namely, 1 / 100 of the quantity of the bacterial bodies obtained by cultivating pUC9-2 plasmid containing the variant aequorin gene for 12 hours was added to a L-broth medium (10 ml) containing Ampicillin (50 μg/ml), followed by cultivating the mixture at 37° C. for 2 hours, adding IPTG so as to give a final concentration of 1 mM, further cultivating the mixture at 37° C. for 2 hours, collecting the resulting bacterial bodies, washing them with M9 salt solution (5 ml), dissolving the resulting washed material in 20 mM Tris-HCl buffer (pH 7.6) (2.5 ml) containing 10 mM EDTA, breaking the bacterial bodies by supersonic wave treatment (60 seconds), carrying out centrifugal separation at 10,000 rpm for 10 minutes and using the resulting supernatant as an enzyme solution to be measured.
As to the measurement method, coelenterazine as a substrate (6 μg) and 2-mercaptoethanol (10 μl) were added to the enzyme solution (1 ml), followed by allowing the mixture to stand on ice for 2 to 3 hours, transferring it into a reaction cell in a phototube measurement apparatus, further pouring 20 mM CaCl 2 (1.5 ml) therein and measuring the resulting luminescence. The results are shown in Table 2.
TABLE 1______________________________________Synthetic oligonucleotide (primer) used inthe site-specific mutagenesis method and the variation siteVariation Name of Synthetic oligonucleotidessite primer 5' 3'______________________________________220th G1R ##STR5##449th G2R ##STR6##607th G3R ##STR7##569th C1S ##STR8##568th C1R ##STR9##590th C2S ##STR10##674th C3S ##STR11##307 & 308th HF ##STR12##238th E35K ##STR13##625th E164K ##STR14##616 & 625th D161H+K ##STR15##205-207th 24ΔD CAATTTCCTT . . . GTCAACCACA592-515th 153ΔD CAGAGTGTGC . . . ATTGATGAAA______________________________________ =; Variation site .; Deleted site
TABLE 2______________________________________Production of variant aequorininside Escherichia coli Activity ×10.sup.-8 Quanta/sec.______________________________________(Measurement 1)Control (Aequorin) 38.9G1R 0G2R 19.2G3R 37.9HF 0E35K 0E164K 0D161H + K 024ΔD 0153ΔD 0(Measurement 2)Control (Aequorin) 22.9C1S 15.4C1R 11.0C2S 13.6C3S 6.8______________________________________
EXAMPLE 2
Example 1 was repeated except that the synthetic oligonucleotide (primer) used in the site-specific mutagenesis method and the variation site were varied. The variant sources used are shown in Table 3 and the results are shown in Table 4.
TABLE 3______________________________________Synthetic oligonucleotide (primer) used inthe site-specific mutagenesis method and the variation siteVariation Name of Primer base arrangementsite primer 5' 3'______________________________________569th C1S ##STR16##590th C2S ##STR17##674th C3S ##STR18##______________________________________
TABLE 4______________________________________Reproduction of variant aequorinsproduced inside Escherichia coli(addition effect of 2-mercaptoethanol) Relative activity value (%) 2-MercaptoethanolVariant aequorin Non-addition Addition______________________________________Control (Aequorin) 8 100C1S 14 54C2S 21 68C3S 30 18C1 + 2S 0 1C2 + 3S 54 26C3 + 1S 36 8C1 + 2 + 3S 95 21______________________________________ Note: In the above table, 100% refers to 3.0 × 10.sup.-9 light quantum/sec. C1 + 2S: a variant obtained by converting the first and second cysteines into serines; C2 + 3S: a variant obtained by converting the second and third cysteines into serines; C3 + 1S: a variant obtained by converting the third and first cysteines into serines; and C1 + 2 + 3S: a variant obtained by converting the first, second and third cysteines into serines.
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Various variants of photoprotein aequorin (pAQ440), useful for elucidating the mechanism of its luminescence and thereby extending the possibility of concrete applications of aequorin protein, and a process for producing variant aequorin proteins are provided, which variants are obtained by converting base(s) in a specified order of the base arrangement of aequorin gene into other base(s), or by deleting a certain bases in specified continued orders thereof, according to site-specific mutagenesis method.
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This is a divisional of application Ser. No. 07/394,052, filed Aug. 17, 1989, now abandoned.
BACKGROUND OF THE INVENTION
Tis invention relates to fluorescent 7-hydroxy coumarin compounds with substitutions in the 4 position having a length greater than one carbon atom. The compounds thus are derivatives of 4-methylumbelliferone (7-hydroxy-4-methyl coumarin, or 4-MU), the detectable label used in the IM x ® instrument assays (Abbott Laboratories, Abbott Park, Ill.).
A number of fluorometric labels are known to one of ordinary skill in the art. However, for compatibility reasons, applicants desired a fluorophore label that had electronic properties substantially similar to the 4-MU utilized in the IM x ® instrument. Otherwise, the label might fluoresce at a wavelength the instrument could not detect absent special filters and the like. A label optimized to the existing instrument was necessary.
The search began for a coumarin or umbelliferone nucleus that had an activated or activatable tether that could be coupled to a desired molecule. Such a tether to a coumarin nucleus had been obtained in the past by a Pechmann condensation to give either a 4-position methyl group or a 3-position alkyl substitution on the coumarin [H. V. Pechmann and C. Duisberg, Chem. Ber. 16, 2119 1883)]: ##STR2## Where R represents the activatable tether.
The 4-methyl product does not provide an activatable tether group. The effect of 3-position substitution on electronic structure in coumarins is shown in the 13 C NMR spectra complied by Parmar and Boll [Mag. Res. Chem., 26, 430-433 (1988)]. If R of the product above is H, the 13 C NMR chemical shift of C-3 is 110 ppm; while if R is CH 2 COOEt, C-3 resonates at 115 ppm. This means that the relative electron density on C-3 has decreased upon alkyl substitution, disturbing the electronic structure of the coumarin nucleus. Thus, the Pechmann condensation was not useful since it did not produce 4-substituted materials, exclusive of having substitution at the 3-position, and since a compound having no substituent at the 3-position was desired because of the need for substantially similar electronic properties as 4-MU.
SUMMARY OF THE INVENTION
In one aspect, the invention relates to a compound of the formula: ##STR3## wherein R 1 is selected from the group consisting of H, --G--OZ, --G--SZ, --G--NHY, --SZ, --NHY, substituted phenyl, and substituted or unsubstituted alkyl of the general formula --G--CH 3 where G represents an alkylene chain having from 1 to about 25 carbon atoms, and Z and Y represent protecting groups; and
wherein R 2 is selected from the group consisting of H, --J--OH, --J--SH, --J--NH 2 , --COOH, --J--OTs, --J--X, --SH, --NH 2 , --COOR', and substituted or unsubstituted alkyl of the general formula --J--CH 3 , where J represents an alkylene chain having from 1 to about 10 carbon atoms, X represents a halide, and R' represents an alkylene chain having from 1 to about 10 carbon atoms.
In another aspect, the invention relates to a process of synthesis for the compounds described above. The steps of the synthesis comprise:
a) reacting 4-bromomethyl-7-methoxycourmarin with a monoalkylated (R 1 ) malonic ester under conditions sufficient to achieve condensation of the ester to give the monoalkylated (2-bis(carbalkoxy)-1-ethyl) derivative;
b) removing one of the carbalkoxy groups from the product of step a);
c) demethylation of the product of step b) to give the 7-hydroxycoumarin compound; and
d) chemically modifying the remaining ester to yield a desired R 2
preferably, step b) is performed according to the process of Krapcho in the presence of NaCl and DMSO at high temperatures. It is also preferred that step c) is performed by reacting ethanethol (EtSH) with the product of step b) at 0° C. in the presence of AlCl 3 and dichloromethane.
Finally, the invention also comprises a method of using the compounds described above. The 7-hydroxy-4-methyl coumarins are known to fluoresce. By conjugating the compounds to a biological macromolecule, the presence of absence of the macromolecule can be quantified. For example, a method of using compounds according to the invention comprises:
a) coupling the compound to a biological macromolecule to be used in a reaction of interest; and
b) determining the amount of macromolecule by measuring the fluorescence of the compound.
Preferably, the compounds according to the invention are conjugated to a member of a specific binding pair, such as an antibody of antigen for determination in an immunoassay. They may also be conjugated to oligonucleotides and used in PCR or other hybridization assays.
DETAILED DESCRIPTION OF THE INVENTION
The invention comprises compositions of matter, processes of synthesis and methods of use for the compounds.
Compounds:
In one aspect, the invention relates to compounds having the general formula: ##STR4##
R 1 is selected from the group consisting of H, --G--OZ, --G--SZ, --G--NHY, --SZ, --NHY, substituted or unsubstituted phenyl, and substituted or unsubstituted alkyl of the general formula --G--CH 3 , where G represents an alkylene chain having from 1 to about 25 carbon atoms, and Z and Y represent protecting groups. R 2 is selected from the group consisting of H, --J--OH, --J--SH, --J--NH 2 , --COOH, --J--OTs, --J--X, --SH, --NH 2 , --COOR', and substituted or unsubstituted alkyl of the general formula --J--CH 3 , where J represents an alkylene chain having from 1 to about 10 carbon atoms, X represents a halide, and R' represents an alkylene chain having from 1 to about 10 carbon atoms.
Arbitrarily, R 1 derives from the central, monoalkylated R 1 of the malonic ester; while R 2 is converted from the COOEt end chain of the ester. R 1 can be selected from any of the groups listed above, although H is preferred. Other R 1 groups may require protecting groups to enable them to withstand the ensuing reactions. As used herein, "protecting group" refers to any group that can be attached to a functional moiety permitting it to withstand future reaction conditions without destroying the function; and which later can be removed or substituted to give back the functional group. For example, if alcohol or thiol groups are used, a protective group Z is used. In the case of alcohols, Z may be t-butyldimethylsilyl of tetrahydropyran; while for thiols, a preferred Z is triphenylmethyl. Protective group Y is similarly required for amino substituents. In this case, acetyl is a preferred protecting group. It is to be understood, of course, that other protecting groups are known in the art, and are obvious extension falling within the scope of the invention.
R 2 can be a greater number of groups since it is converted from the COOEt ester after the other reactions are completed. Conventional organic chemistry methods can place almost any group in the R 2 position, although there is little practical reason why some groups would be made. The preferred group will be dictated by the linking moiety present on the biological macromolecule of interest (see below). For example, if the macromolecule contains a primary amine, it is preferred that R 2 be (or be converted to) a N-hydroxysuccinimide ester. Other preferred R 2 groups are given in Table 1 below. A tosyl group, Ts, may also be created at R 2 and is useful as an intermediate to create other R 2 groups as shown in the Examples.
As used herein, "alkylene" refers to any straight or branched chain spacer groups containing less than 50 carbon atoms, including but not limited to, --CH 2 --, --CH(CH 3 )--, --CH(C 2 H 5 )--, --CH(CH 3 )CH 2 --, --(CH 2 ) 3 --, and the like. The length of the alkylene chain is preferably short to enhance solubility, to avoid steric problems, and to be readily available commercially. Ideally, the alkylene chain G should be from 1 to about 10 carbon atoms long, while the alkylene chain J should be from 1 to about 5 carbon atoms long. In either case, the alkylene chain may be substituted.
"Aryl" refers to substituents having ring structures. For solubility reasons, phenyl or substituted phenyl is preferred over larger aryl groups.
Both aryl and alkylene substituents at the R 1 positions may be substituted. As used herein, "substituted" refers to the presence of moieties covalently bonded to the aryl or alkylene groups, including, but not limited to, halide (especially Br and Ci), nitro, lower alkoxy (having from 1-6 carbon atoms, especially methoxy and ethoxy), lower alkyl (having from 1-6 carbon atoms, especially methyl and ethyl), hydroxy, and amino (protecting group may be required). Subject to the limits of organic chemistry, the substituting groups may be placed anywhere, and in any number, on the alkylene or phenyl substituent.
It should be recalled that the object of the invention was to put a tether group in the 4 position of the coumarin nucleus. Therefore, if R 1 is H, it is pointless to convert R 2 to H or alkyl since there would then be no functional group to serve as a tether. It is important to the invention that at least one of R 1 and R 2 provide a functional group that is, or can be activated to be, reactive with a biological macromolecule or a linker as described below.
The compounds of the present invention find utility as fluorophores. Specifically, the side chains in the 4 position enable the compounds to be covalently coupled to other molecules through conventional chemistries, without affecting the electron configurations that are responsible for this fluorometric properties. For example, the 7-hydroxy-2-oxo-2H-1-benzopyran-4-propionic acid was synthesized for the purpose of covalently labeling biological macromolecules such as oligonucleotide primers. An example of how the compounds are so used can be found in copending application Ser. No. 07/394,051, filed Aug. 17, 1989 which is incorporated herein by reference. The labeled macromolecules can then be detected by any fluorometric procedure, such as on an IM x ® instrument, without recourse to enzymatic signal amplification.
The compounds can be also be used as dye markers at the 5' end of an oligonucleotide for sequencing purposes.
Process of Synthesis:
The compounds of the present invention can be chemically synthesized in 3 or more steps starting the from 4-bromomethyl-7-methoxycoumarin 1 (Aldrich Chemical Co., Milwaukee, Wis.). The compounds were prepared as shown below. Generally speaking, malonic ester displacement of the bromide in 1, in the presence of NaH, afforded monoalkylated 2 according to the following reaction: ##STR5##
Krapcho decarbalkoxylation [Krapcho, A. P.; Weimaster, J. F.; Eldridge, J. M.; Jahngen, Jr., E. G. E.; Lovey, A. J.; Stephens, W. D. J. Org. Chem. (1978) 43: 138-147] removed one of the two ester groups to give 3 in good yield. The reaction is best carried out at high temperatures using NaCl as follows: ##STR6##
Demethylation of 3 to give the 7-hydroxycoumarin was accomplished under the conditions of Fujita as described in [Node, et al J. Org. Chem. (1980) 45: 4275-4277]. Briefly, the conditions involve a strong Lewis acid, AlCl3, and ethane thiol (EtSH) as a weak Lewis base, a source of protons, and a soft nucleophile. After several other methods {including BBr 3 , [McOmie, et al. Tetrahedron (1968) 24: 2289-2292]; Me 3 Sil, [Ho, et al, Angew, Chem. (1976) 88: 847]; and NaSEt [Feutrill, et al. Tetrahedron Letters (1970) 161: 327-328]} failed, the conditions of Fujita finally effected demethylation to give 4, albeit in only low yields. ##STR7##
The ester is among the claimed R 2 groups. To arrive at the other R 2 groups, conventional organic chemistry can be used, directly from the ester or from other intermediate groups. For example, saponification of 4 gave the acid 5 as shown below. ##STR8##
From either the ester or the acid, the remaining R 2 groups can be obtained through the following reactions. Where R 2 is to be an alcohol, LiBH4 reduction gives the desired product. The alcohol hydroxyl can then be converted to either the thiol or the amino through the intermediate hydroxy tosylate. The ester may also be reduced to the aldehyde using diisobutylaluminum hydride (DIBAL, Aldrich Chemical Co.). Longer alkylene chains can be synthesized from the aldehyde using an appropriate Wittig or Wadsworth/Emmons reagent.
Methods of Use:
Finally, the invention also comprises a method of using the compounds described above. The 7-hydroxy-4-methyl coumarins are known to fluoresce. By conjugating the compounds to a biological macromolecule, the presence or absence of the macromolecule can be quantified. For example, compounds according to the invention may be conjugated to antibodies for determination in an immunoassay. They may also be conjugated to oligonucleotides and used in PCR or other nucleic acid hybridization assays.
The conjugation is generally carried out by activating the fluorophore with a reactive group. In the case of a carboxyl R 2 to be reacted with a primary amine on a target macromolecule, the preferred activator is N-hydroxysuccinimide ester. Other activating groups are known in the art for use with the various R 2 groups and various target macromolecule linking moieties. Table 1 below is a nonexhaustive listing of some exemplary target moieties, likely R 2 groups and useful activators. In some cases, the conjugation is best performed using a linker or spacer molecule. The linker may be heterobifunctional or homobifunctional depending on the circumstances. The correct linker can also be determined by one of ordinary skill in the art.
______________________________________TargetMoiety (on Preferred R.sub.2biomolecule Linker Group Activator______________________________________amine none carboxyl NHS-esteramine maleimide thiol none (stable linkage)amine thiol thiol none (easily reversible linkage)carboxyl none amine (carbodiimide)vicinal diol (oxidation) amine (cyanoborohydride reduction after linkage)thiol none amine maleimide (stable linkage)thiol none thiol none (easily reversible linkage)hydroxyl (convert to amine none tosyl)hydroxyl (convert to hydroxyl none phosphate ester)______________________________________
The invention will now be further described by way of Examples.
EXAMPLES
EXAMPLE 1
Synthesis of 4-(2-carboxy-1-ethyl)-7-hydroxy-2-oxo-2H-1-Benzopyran
Throughout this example, R represents Hydrogen.
A. materials and Methods
Chemical reagents were purchased from Aldrich. Proton NMR spectra were obtained at 300 MHz on a General Electric QE-300 spectrometer, referenced to TMS internal standard in ppm (δ). Coupling constants are given in hertz. Mass Spectra were obtained using direct chemical ionization on a Kratos MS 50 instrument. Amino modifier II was purchased from Clontech Laboratories (Palo Alto, Calif.) TLC analyses were done using 250 μm Analtech silica gel plates. Flash column chromatographies were run with EM Kieselgel-60 (70-230 mesh). Spectral and elemental analyses were performed by the Analytical Research Department, Abbott Laboratories.
B. Synthesis of 4-(2-bis(carbethoxy)-1-ethyl)-7-methoxy-2-oxo-2H-1-Benzopyran (2) ##STR9## To a suspension of 240 mg of 60% NaH mineral oil dispersion (6 mmol) in 10 mL of DMF was added 961 μL (6 mmol) of diethyl malonate. After the foaming subsided and the suspension cleared to a solution, 1346 mg (5 mmol) of 4-bromomethyl-7-methoxycoumarin was added all at once. After stirring for 4 h at room temperature, the DMF was stripped off, and the residue partitioned between 0.01 M HCl/hexane. The organic phase was concentrated and vacuum dried, then as much as possible was taken up into 4 mL of 50/50 EtOAc/hexane. Flash chromatography gave 670 mg of 2 as a white solid, 49%.
Analysis gave:
1H NMR (CDCl 3 ) δ7.56 (d, 1 H, J=8.8), 6.88 (dd, 1 H, J=2.6, 8.8), 6.84 (br s, 1H), 4.23 (q, 2 H, J=7.2), 4.22 (q, 2 H, J=7.2), 3.88 (s, 3 H), 3.74 (t, 1 H, J=7.4), 3.36 (dd, 2 H, J=1.1, 7.4), 1.27 (t, 6 H, J=7.4)
MS m/z 349 (100, M+H)
IR (film, cm-1) 1715 (vs), 1614 (vs)
Anal. (C 18 H 20 O 7 ) C, H.
C. Synthesis of 4-(2-carbethoxy-1-ethyl)-7-methoxy-2-oxo-2H-1-Benzopyran (3) ##STR10## To a solution of 44.8 mg (0.13 mmol) of 2 in 6 mL of DMSO was added 15 mg of NaCol, followed by 4.6 mL of water. The reaction was stirred in an oil bath at 180° C. for 2.5 h, and was cooled to room temperature. After addition of 45 mL of water to the reaction mixture, the resultant emulsion was extracted with 2×40 mL EtOAc. The organic phase was concentrated by rotary evaporation, and was vacuum dried. After uptake into 3 mL of 25% EtOAc in hexane, flash chromatography using the same solvent system gave 31.4 mg of 3, 88%.
Analysis gave:
1H NMR (CDCl 3 ) δ7.55 (d, 1H, j=8.8), 6.88 (dd, 1H, J=2.6, 8.8), 6.83 (d, 1H, J=2.6), 6.13 (t, 1H, J=1.1), 4.19 (q, 2H, J=7), 3.88 (s, 3H), 3.06 (t, 2H, J=8), 2.71 (t, 2H, J=8), 1.28 (t, 3H, J=7)
MS 277 (100, M+H)
IR (film, cm-1) 1730 (vs), 1612 (vs)
Anal. (C 15 H 16 O 5 ) C, H.
D. Synthesis of 4-(2-carbethoxy-1-ethyl)-7-hydroxy-2-oxo-2H-1-Benzopyran (4) ##STR11##
To a suspension of 726 mg (5.4 mmol) of AlCl 3 in 10 mL of dichloromethane at 0° C. was added 4 mL of EtSH. The suspension became a clear solution within seconds. Then, 298 mg (1.08 mmol) of 3 in 4 mL of dichloromethane was added, turning the yellow solution red in color. The ice bath was removed, and the reaction stirred to room temperature for 3 h. The solvents were removed in vacuo, and the residue thoroughly vacuum dried. The residue was extracted into EtOAc as much as possible, then the extract was flash chromatographed using 30/70 EtOAc/hexane. The long- and short-wave UV active band gave 76.7 mg (27%) of 4.
Analysis gave:
1H NMR (CDCl 3 ) δ7.5 (d, 1H, J=8.5), J=8.5), 6.9 (d, 1H, J=2.6), 6.85 (dd, 1H, J=8.5, 2.6), 6.1 (br s, 1H, 4.18 (q, 2H, J=7.4), 3.08 (br, t, 2H, J=7), 2.71 (br t, 2H, J=7), 1.28 (t, 3H, J=7.4)
MS 263 (M+H)
IR (Film, cm-1) 3280 (s, br), 1730 (vs), 1693 (vs), 1608 (vs), 1565 (s)
Anal. (C 14 H 14 O 5 ) C,H.
E. Synthesis of 4-(2-carboxy-1-ethyl)-7-hydroxy-2-oxo-2H-1-Benzopyran (5) ##STR12##
A 36.7 mg sample of ester 4 was suspended into 10 mL of water, and 25 mL of 50% aqueous NaOH was added. The resultant solution was stirred at room temperature for 4 h. TLC analysis (30/70 EtOAc/hexane) after this time showed that no starting material remained. The mixture was acidified using 1 mL of 1 M HCl. A precipitate formed upon acidification, and the white solid was left to deposit for 1 h. After the solid was filtered off and thoroughly washed with 1 M HCl, it was vacuum dried to give 14.1 mg (43%) of analytically pure 5.
Analysis gave:
1H NMR (NaOD/D 2 O) δ7.5 (d, 1H, J=8.8), 6.74 (dd, 1H, J=2.2, 8.8), 6.53 (d, 1H, J=2.2), 5.97 (br s, 1H), 2.91 (t, 2H, J=7.4), 2.5 (t, 2H, J=7.4)
MS (FAB, H2O) 235 (M+H)
IR (KBr, cm-1) 3440 (s, br), 1710 (vs), 1611 (vs), 1568 (vs), 1400 (s)
Anal. (C 12 H 10 O 5 ) C, H.
F. Synthesis of 4-(2-carboxy-1-ethyl)-7-hydroxy-2-oxo-2H-1-Benzopyran, N-hydroxy succinimide ester (6). ##STR13## To a suspension of 6.4 mg (27.3 mmol) of 5 in 6 mL of MeCN was added 4.7 mg (41 mmol) of N-hydroxysuccinimide, 8.4 mg (41 mmol) of dicyclohexylcarbodiimide (DCCD) and 2 mg of 4,4-dimethylaminopyridine. The reaction was stirred at room temperature for 24 h, and the solvent was removed in vacuo. The residue was taken up into 750 μL of DMF, and coupled directly with oligonucleotide.
The coupling and use of this product are described in more detail in copending application Ser. No. 07/394,051 filed Aug. 17, 1989, which has been incorporated herein by reference.
EXAMPLE 2
Synthesis of 4-(2-carboxy-2-R 1 -1-ethyl)-7-hydroxy-2-oxo-2H-1-Benzopyran
Example 1 is repeated with R 1 group s according to Table 2.
TABLE 2
R 1 group
--CH 3
--CH 2 CH 3
--CH 2 CH 2 -O-t-butyldimethylsilyl
--CH 2 CH 2 -NH-acetyl
--NH-acetyl
EXAMPLE 3
Synthesis of Alcoholic R 2 Group
Compound (4) from Example 1 is modified to contain an alcoholic R 2 group (--CH 2 OH) by reducing the ester with LiBH 4 under conditions cited by Brown in: H. C. Brown, Hydroboration, p. 245, Benjamin, N.Y., N.Y. (1962).
EXAMPLE 4
Synthesis of Thiol R 2 Group
The compound from Example 3 is modified to contain a thiol R 2 group (--CH 2 SH) by conversion using the tosylate under conditions of Price and Stacy in: Organic Synthesis Collective vol. 3, p. 86 (1955).
EXAMPLE 5
Synthesis of Amine R 2 Group
The compound from Example 3 is modified to contain an amino R 2 group (--CH 2 NH 2 ) by conversion using the tosylate under conditions of a Gabriel synthesis of primary amines, wherein the tosylate is displaced by sodium phthalimide. The phthalimide is then removed with hydrazine to give the primary amine.
The above examples serve to illustrate the invention and should not be construed as limiting the scope of the invention. Rather, the scope of the invention is limited only by the appended claims.
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A process for synthesis of a compound of the formula: ##STR1## said process comprising the steps of (a) reacting 4-bromomethyl-7-methoxy coumarin with a malonic ester under conditions sufficient to achieve condensation of the ester to give the monoalkylated (2-bis(carbalkoxy)-2-R 1 -1-ethyl) derivative; (b) removing one of the carbalkoxy groups from the product of step (a); (c) demethylation of the product of step (b) to give the 7-hydroxycoumarin compound; and (d) chemically modifying the remaining ester to yield a desired R 2 .
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RELATED APPLICATIONS
[0001] This application claims priority as a divisional application of U.S. patent application Ser. No. 10/267,188 filed Oct. 9, 2002, the entirety of which is hereby incorporated by reference.
TECHNICAL FIELD
[0002] The present invention generally relates to the repair of internal body tissue. More particularly, the present invention relates to surgical instruments and procedures that can be used for the repair of hernias.
BACKGROUND OF THE INVENTION
[0003] A hernia is a defect in a muscle of a person through which internal body organs can protrude into the inguinal tissue. This can happen in the groin area, the abdominal wall, the bowels, the diaphram, the scrotal sac or even a disk in the vertebral bones. Hernias can cause discomfort as well as a lump under the skin. The most common type of hernia occurs in the abdomen, in which part of the intestines protrude through the abdominal wall to form a hernial sac. When such a hernia occurs in the abdominal region, conventional corrective surgery has been required to correct the defect.
[0004] Surgical mesh materials or patches have been developed for the repair of hernias. These mesh materials help reinforce and close the hernia. Various surgical techniques have been utilized to apply and secure the surgical mesh over the hernia. In one surgical approach, laparascopy techniques and devices are utilized to apply a surgical mesh from a remote location under the hernia to be repaired. This surgical operation generally involves repairing the hernia by retracting the intra-abdominal contents away from the hernia defect and then inserting a bundle of surgical mesh into the patient to block the defect. A surgical patch is usually secured over the mesh to hold it in place.
[0005] However, surgical operations utilizing such laparacopic devices and techniques can be complicated. In addition, such operations typically require the use of general anesthesia and costly disposable instrumentation to support the laparoscopic surgery. In addition, this surgical technique can suffer from the difficulty of spreading and holding the surgical mesh over the defect in a satisfactory manner. Further, it may be difficult to affix the surgical patch in a smoothly expanded manner without causing substantial subsequent tension on the abdominal portions to which the mesh is affixed.
[0006] In another surgical approach, a hernia can be repaired by attaching a surgical patch directly over the hernia. In this technique, a surgeon opens the abdominal cavity of a patient by a surgical incision through the major abdominal muscles. Several layers of the abdominal wall are generally separated to reach the herniated portions and to prepare an opening for the insertion of the surgical patch. Before the surgical patch is inserted into the patient, 4-12 sutures are passed under a memory recoil ring located near the perimeter of the patch. The surgeon then folds and compacts the surgical patch and inserts the patch through the incision into the patient's preperitoneal space. Thereafter, the surgeon uses his fingers to move and flatten out the patch within the preperitoneal space to ensure that none of the edges of the patch are flipped back. Once the hernia mesh patch covers the defect in the patient's abdominal cavity, the edges of the fascial defect are lifted and the perimeter sutures previously placed through the patch are passed through the peritoneum and posterior fascia/sheath. The sutures are then tied and trimmed.
[0007] However, if the sutures are not passed through the tissue directly above the ring of the patch, the sutures may be placed under tension and the patch may become distorted. In addition, it can also be time consuming for the surgeon to secure all of the sutures in place. Further, the surgical patch utilized in this technique typically includes the use of a resilient circumferential ring located near the outer edge that creates tension throughout the patch to help expand the patch, thereby increasing the cost of the patch.
SUMMARY OF THE INVENTION
[0008] In view of the above, the present invention provides surgical apparatus and procedures for the repair of hernia. The surgical apparatus and procedures provide a low cost and efficient procedure for the repair hernias. The surgical apparatus and procedures also allow a hernia to be repaired with less tension, a smaller wound or incision, superior fixation and at a potentially lower cost to the patient than traditional methods. The apparatus and procedures further allow a surgeon to secure a patch over a defect without the use of sutures and in less time than traditional surgical procedures.
[0009] One method for repairing a hernia in accordance with the present invention includes the steps of making an incision through a skin layer of a patient near the hernia, creating an entrance into the preperitoneal space above the peritoneum at a location above the hernia, identifying and freeing a hernia sac, creating a pocket in the preperitoneal space, directing a surgical patch down through the incision and into the preperitoneal space, and expanding the surgical patch in the preperitoneal space. The method further includes the steps of inserting a distal end of a surgical fastening device through the incision and into the surgical patch, actuating the surgical fastening device to drive a fastener through the surgical patch and into the tissue of the patient, moving the distal end of the surgical fastening device to another location, actuating the surgical fastening device to drive a second fastener through the surgical patch and into the tissue of the patient, and closing the incision with stitches.
[0010] One surgical apparatus in accordance with the present invention includes a surgical patch applicator for positioning a patch of surgical patch over a hernia defect. The surgical patch applicator generally includes an elongated member having a first end and a second end. The second end is sized for insertion into an opening of the surgical hernia patch. A lumen extends through the elongated member and a balloon is coupled to the second end of the elongated member. The balloon inflates in a planar direction to expand the surgical hernia patch over the hernia defect when a fluid is introduced into the lumen.
[0011] Another surgical apparatus in accordance with the present invention includes a surgical stapling instrument for applying at least one surgical staple to fasten a surgical hernia patch to internal body tissue. The surgical instrument includes a handle assembly have a longitudinal axis. A staple cartridge housing is mounted to the handle assembly and is adapted to receive the at least one staple. The staple cartridge housing is dimensioned for insertion through an incision and has a staple actuator mechanism for applying the at least one staple into the tissue. An actuation mechanism is operatively coupled to the staple actuator mechanism to operate the staple actuation mechanism. A surgeon can rotate the staple cartridge housing in order to apply staples at desired surgical locations.
[0012] The invention, together with further attendant advantages, will best be understood by reference to the following detailed description of the presently preferred embodiments of the invention, taken in conjunction with the accompanying drawings. It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory and are intended to provide further explanation of the invention as claimed.
BRIEF DESCRIPTION OF THE DRAWINGS
[0013] A preferred embodiment of the present invention will be described in detail below in connection with the drawings in which:
[0014] FIG. 1 is a diagrammatical view of the repair of a hernia of a patient using surgical apparatus in accordance with the present invention;
[0015] FIG. 2 is a fragmentary diagrammatical cross-sectional view of an incision in an abdominal wall of a patient having a hernia, wherein a surgical hernia patch is being prepared for insertion into the incision of the patient;
[0016] FIG. 3 is a fragmentary diagrammatical cross-sectional view of the incision in the abdominal wall of FIG. 2 , wherein the surgical hernia patch is being inserted into hernia of the patient;
[0017] FIG. 4 is a fragmentary diagrammatical cross-sectional view of the incision in the abdominal wall of FIG. 2 , wherein a balloon of a surgical patch applicator is inserted into the incision and into the surgical hernia patch;
[0018] FIG. 5 is a fragmentary diagrammatical cross-sectional view of the incision in the abdominal wall of FIG. 2 , wherein the balloon of the surgical patch applicator is inflated to expand the surgical hernia patch;
[0019] FIG. 6 is a fragmentary diagrammatical cross-sectional view of the incision in the abdominal wall of FIG. 2 , wherein a stapling cartridge housing of a surgical stapling instrument is inserted into the incision and into the surgical hernia patch;
[0020] FIG. 7 is a side elevational view of the surgical patch applicator of FIG. 4 ;
[0021] FIG. 8 is a side elevational view of the surgical stapling instrument of FIG. 6 ;
[0022] FIG. 9 is a side elevational view of another embodiment of a surgical stapling instrument in accordance with the present invention;
[0023] FIG. 10 is a side elevational view another embodiment of a surgical stapling instrument in accordance with the present invention, with the instrument in its extended position;
[0024] FIG. 11 is a side elevational view of the surgical stapling instrument of FIG. 10 , with the instrument in its retracted position;
[0025] FIG. 12 is a side elevational view of another embodiment of the surgical stapling instrument having a plurality of staple cartridge housings in accordance with the preset invention;
[0026] FIG. 13 is a perspective view of the surgical patch of FIG. 1 ; and
[0027] FIGS. 14-20 show various embodiments of surgical fasteners.
DESCRIPTION OF PREFERRED EMBODIMENTS
[0028] Before explaining the preferred embodiments in detail, it should be noted that the invention is not limited in its application or use to the details of construction and arrangement of parts illustrated in the accompanying drawings and description, because the illustrative embodiments of the invention may be implemented or incorporated in other embodiments, variations and modifications, and may be practiced or carried out in various ways. Furthermore, unless otherwise indicated, the terms and expressions employed herein have been chosen for the purpose of describing the preferred embodiments of the present invention for the convenience of the reader and are not for the purpose of limitation.
[0029] Referring now to the drawings in detail, and particularly to FIGS. 1-6 , a procedure for the repair a hernia of a patient is illustrated. The surgical procedure allows a hernia to be repaired with less tension, a smaller wound or incision, superior fixation and at a potentially lower cost to the patient than traditional methods. The surgical procedure also allows a surgeon to repair a hernia more quickly than traditional techniques and without the use of sutures. Although the surgical procedure will be described in reference to a repair of an inguinal hernia, it will be recognized that the following surgical procedure can be used to repair other types of hernias and internal tissue of a patient.
[0030] As shown in FIG. 1-2 , the surgeon creates an entrance into the patient by opening the abdominal cavity by creating a surgical incision 100 through the major abdominal muscles. The surgical incision 100 is preferably positioned approximately two to three centimeters above the location where an inguinal hernia 102 has occurred. The surgical incision 100 can be made by a blade, such as a surgical scalpel.
[0031] After the incision 100 is made in the abdominal cavity, the surgeon then works through the incision 100 and uses a muscle splitting technique to dissect deeply into the patient's preperitoneal space 104 . Several layers of the abdominal wall are generally separated to reach the herniated portions and to prepare an opening for the insertion of a surgical hernia patch 200 . During the separation, the surgeon identifies and frees up the hernia sac and creates a pocket 106 in the preperitoneal space 104 where the surgical hernia patch 200 can be inserted.
[0032] After the pocket 106 in the preperitoneal space 104 has been created, the surgeon selects a suitable surgical hernia patch 200 to be used for the repair of the patient's hernia 102 . The selected surgical hernia patch 200 is folded and further compacted, as may be necessary, by the surgeon so that the selected surgical hernia patch 200 may be conveniently inserted through the incision 100 and down into the properitoneal space 104 as shown in FIG. 3 .
[0033] Once the surgical hernia patch 200 is inserted in the preperitoneal space 104 , the surgeon can then use a hernia patch applicator 300 to conveniently and accurately position the surgical hernia patch 200 to cover the hernia 102 . In order to position the patch, the surgeon inserts the hernia patch applicator 300 into the incision and into the surgical hernia patch 200 as shown in FIG. 4 . A balloon 302 of the hernia patch applicator 300 is passed through a slit or hole 202 in the top layer of the surgical hernia patch 200 and into a pouch formed between the top and bottom layers of the surgical hernia patch 200 . The balloon 302 is then inflated to cause the surgical hernia patch 300 to unfold and expand into a planar configuration in the pocket 106 within the preperitoneal space 104 as shown in FIG. 5 , thereby causing the surgical hernia patch 200 to expand over the hernia. The hernia patch applicator 300 can easily move and expand the surgical hernia patch 200 over the hernia 102 so that the edges of the surgical hernia patch 200 overlap the circumference of the hernia 102 . Once the surgical hernia patch 200 is properly positioned, the balloon 302 of the hernia patch applicator 300 is deflated and removed.
[0034] Alternatively, the surgical hernia patch 200 may initially be placed over the balloon 302 of the surgical patch applicator 300 and then inserted into the incision 100 of the patient. Thereafter, the balloon 302 may be inflated to cause the surgical hernia patch 200 to expand over the hernia 102 . It will also be recognized that the surgeon may desire to use his fingers to position the surgical hernia patch 200 instead of using the hernia patch applicator 300 .
[0035] Once the surgical hernia patch 200 is properly positioned, the surgeon closes the hernia 102 by applying a plurality of staples or fasteners with a surgical stapling instrument 400 to secure the surgical hernia patch 200 to the abdominal wall of the patient. In order to fasten the surgical hernia patch 200 to the abdominal wall, the surgeon inserts a staple cartridge housing 402 of the surgical stapling instrument 400 into the slit or opening 202 in the top layer of the surgical hernia patch 200 as shown in FIG. 6 . When the staple cartridge housing 402 is positioned at a desired location, a staple actuator button 412 of the surgical stapling instrument 400 is pressed to drive a staple or fastener through the top layer of the surgical hernia patch 200 and into the tissue of the abdominal wall. Thereafter, the staple cartridge housing 402 is rotated to another location and the operation is repeated to drive another staple through the surgical hernia patch 200 and into the tissue. The staple cartridge housing 402 can be readily rotated to different positions to apply staples at various locations along the edges of the surgical hernia patch 200 . After the surgical hernia patch 200 is secured to the patient, the surgeon removes the surgical stapling instrument 400 and closes the incision 100 .
[0036] Soon after the surgery, the patient's body reacts to the surgical hernia patch 200 and scar tissue grows into the patch to permanently fix the surgical hernia patch 200 in its intended position over the repaired area, where the hernia 102 was located. The surgical hernia patch 200 also helps protect against future hernias.
[0037] Referring now to FIG. 7 , a preferred embodiment of the surgical patch applicator 300 for use in the repair of a hernia is illustrated. The surgical patch applicator 300 allows a surgical hernia patch to be readily positioned over the circumference of the hernia. The surgical patch applicator 300 preferably includes an elongated body or tube 302 and an inflatable/deflatable balloon 304 .
[0038] The elongated body 302 of the surgical patch applicator 300 preferably has a substantially circular cross-section, but may have any suitable cross-section, such as a square or an elliptical cross-section. The elongated body 302 can have any suitable length depending upon the particular hernia procedure and can be constructed of any suitable material that provides sufficiently rigidity to permit insertion of the elongated body into the herniated site. The elongated body 302 can be constructed from nylon, Teflon, polyurethane, or polyethylene. It will be recognized that the elongated body 302 can be made from a variety of other materials including, for example, polypropylene, polyamide, polyethylenterephthalate, polyamide, other polymers and polycarbonates as well as other suitable forms of plastic.
[0039] The proximal end 306 of the elongated body 302 is attached to a connector or adaptor 308 through which fluid may be introduced under pressure into the balloon. The connector 308 permits the elongated body 302 to be attached or coupled to other devices, such as, a fluid source. The connector 308 can include, but is limited to, a Luer Lock connector, a quick connector, a ferrule connector, a threadable connector, and the like.
[0040] As shown in FIG. 7 , the elongated body 302 of the surgical patch applicator 300 further has an interior lumen or conduit 310 positioned therein. The lumen 310 can be any suitable size and shape. The lumen 310 extends longitudinally from the proximal end 306 of the elongated body 302 to an opening or aperture 312 at the distal end 314 of the elongated body 302 . The opening 312 permits the fluid to be transmitted through the lumen 310 into the interior of the balloon 304 to controllably inflate and/or deflate the balloon 304 as further described below.
[0041] The balloon 304 of the surgical patch applicator 300 is preferably attached at the distal end 314 of the elongated body 302 . The balloon 304 can be made of latex, silicone rubber, polyethylene, polyamide or any other suitable material. The balloon 304 can be configured in various sizes. The balloon 304 is disposed over the opening 312 in the elongated body 302 to permit the lumen 310 to be in fluid communication with the interior of the balloon 304 . As a result, when fluid is transmitted through the lumen 310 and into the interior of the balloon 304 , the fluid will cause the balloon 304 to inflate. When the balloon 304 is inflated, the balloon 304 preferably expands radially outward or in a planar fashion to form a disk-like shape. FIG. 5 shows the balloon 304 in an expanded configuration in which the balloon 304 is inflated.
[0042] When the fluid is extracted or removed from the interior of the balloon 304 , the balloon 304 will deflate. The fluid that may be used to inflate and deflate the balloon 304 can be a liquid, such as water or saline, or a gas, such as air, inert gas, carbon dioxide, helium, nitrogen, or the like. The fluid may be injected into and removed from the lumen 310 of the surgical patch applicator 300 by a fluid source such as, for example, a rubber bulb, a syringe, a micro pump or the like (not shown).
[0043] Referring now to FIG. 8 , a preferred embodiment of the surgical stapling instrument 400 for attaching a surgical hernia patch to internal body tissue is illustrated. The surgical stapling instrument 400 is adapted for insertion through a slit or a slot of the surgical hernia patch in order to apply one or more surgical staples through the top layer of the surgical hernia patch and into the patient's tissue at a desired surgical site. Preferably, the surgical stapling instrument 400 applies the staples near the edges of the surgical hernia patch. The surgical stapling instrument 400 may be readily rotated to various different positions to apply the staples or fasteners at various locations along the edges of the surgical hernia patch.
[0044] As shown in FIG. 8 , the surgical stapling instrument generally 400 includes a handle assembly 402 and a staple cartridge housing 404 . The handle assembly 402 preferably consists of a plastic material, but may be constructed from any suitable material. The handle assembly 402 of the surgical stapling instrument 400 generally includes an outer sleeve 406 , an inner sleeve or shaft 408 , a rotatable control knob 410 , and a stapler actuator button 412 .
[0045] The outer sleeve 406 of the handle assembly 402 is substantially cylindrically shaped and is adapted to be held by a user or surgeon, but may be any suitable shape or size which allows it to be grasped by the user. The outer sleeve 406 may include a manual grip to facilitate grasping of the surgical stapling instrument 400 by a user.
[0046] As shown in FIG. 8 , the distal end 414 of the inner sleeve 408 is connected to the staple cartridge housing 404 , and the proximal end 416 of the inner sleeve 408 is coupled to the staple actuating button 412 . The staple actuating button 412 causes the surgical stapling instrument 400 to advance and drive a staple or fastener disposed in the staple cartridge housing 404 into the tissue at the surgical site.
[0047] The rotatable control knob 410 of the surgical stapling instrument 400 is attached to inner sleeve 408 and is adapted to rotate the inner sleeve 408 about its longitudinal axis, thereby rotating the staple cartridge housing 404 relative to the outer sleeve 406 of the handle assembly 402 . The control knob 410 can rotate the staple cartridge housing 404 a full 360 degrees. The control knob 410 preferably comprises a disc-like member, but may be any suitable shape or size which allows it to be rotated by the user.
[0048] The handle assembly 402 may also include a ratchet mechanism (not shown) to allow the user to set and retain the staple cartridge housing 404 at different rotational positions relative to the longitudinal axis of the outer sleeve 406 of the handle assembly 402 . The ratchet mechanism may be formed by a plurality of ratchet teeth on the outer wall of the inner sleeve 408 of the handle assembly 402 for engaging a pair of notches or detents mounted on inner wall of the outer sleeve 406 . The ratchet teeth and detents provide a ratchet mechanism for controlling and retaining the staple cartridge housing 404 in different rotational positions relative the longitudinal axis of the inner sleeve 408 . The notches can provide a series of stop positions which correspond to angular orientations preferably of 0, 45, 90, 135, 180, 225, 270, 315, and 360 degrees relative to the longitudinal axis of the inner sleeve 408 . In one embodiment, the inner wall of the outer sleeve is provided with notches which allow the staple cartridge housing 404 to be rotated in 8 equal angular increments of 45 degrees. It will be recognized that the outer wall of the inner sleeve may contain the notches while the inner wall of the outer sleeve contains the ratchet teeth.
[0049] Referring still to FIG. 8 , the staple cartridge housing 404 is mounted for rotation about the longitudinal axis of the handle assembly 402 . The control knob 410 of the surgical stapling instrument 400 can be turned by a user to rotate the staple cartridge housing 404 in order to adjust the rotational position of the staple cartridge housing 404 relative to the handle assembly 402 . The staple cartridge housing 404 includes a staple actuating device 418 and a staple or fastener cartridge 422 . The staple cartridge 422 of the surgical cartridge housing 404 contains a plurality of staplers or fasteners that can be driven upwardly relative to the longitudinal axis of the handle assembly 402 for placement in tissue. The staple actuating device 418 advances the staple and drives the staple into the tissue. The staple actuating device 418 preferably prevents more than one fastener from being placed in the “ready” position. A variety of actuation and fastener feeding mechanisms may be employed to advance the staplers or fasteners in the staple cartridge 422 of the surgical stapling instrument 400 and to place the fasteners in the tissue at the surgical site.
[0050] In use, the stapling cartridge housing 404 is positioned at the desired position over the surgical site by operating the rotatable control knob 410 to adjust the rotational orientation of the staple cartridge housing 404 . With the staple cartridge housing 404 adjusted to the desired orientation, the staple actuator button 412 is squeezed to actuate the staple actuating device 418 to apply one of the staples to the tissue at the surgical site. Thereafter, the staple cartridge housing 404 is rotated to another location and the operation is repeated to apply another staple to the tissue. These features of the surgical stapling instrument 400 allow the staple cartridge housing 404 to be aligned with the desired region of the internal body tissue to which the staple or fastener is applied. Although the surgical stapling instrument 400 is described as a single load device, it will be recognized that it may be multiple load device. It will also be recognized that the surgical stapling instrument 400 may use any suitable staple or fastener, such as a surgical anchor, a surgical screw, or the like.
[0051] Referring now to FIG. 9 , another embodiment of a surgical stapling instrument 500 is illustrated. The surgical stapling instrument 500 in many respects corresponds in construction and function to the previously described surgical stapling instrument 400 of FIG. 8 . Components of the surgical stapling instrument 500 which generally correspond to those components to the surgical stapling instrument 400 of FIG. 8 are designated by like reference numerals in the 500 hundred series. As shown in FIG. 9 , the surgical stapling instrument 500 generally includes a handle assembly 502 , a staple cartridge housing 504 , and a staple actuating button 512 . In this embodiment, the surgeon manually rotates the handle assembly to rotate the staple cartridge housing 504 . It will also be recognized that a gripping member or outer sleeve may be coupled to the handle assembly 502 .
[0052] Referring now to FIGS. 10-11 , another embodiment of a surgical stapling instrument 600 is illustrated. The surgical stapling instrument 600 in many respects corresponds in construction and function to the previously described surgical stapling instrument 500 of FIG. 9 . Components of the surgical stapling instrument 600 which generally correspond to those components to the surgical stapling instrument 500 of FIG. 9 are designated by like reference numerals in the 600 hundred series. As shown in FIGS. 10-11 , the staple cartridge housing 604 of the surgical stapling instrument 600 can be extended and retracted to facilitate the insertion into a surgical hernia patch and/or application of fasteners. FIG. 11 shows the surgical stapling instrument 600 in its retracted position while FIG. 10 shows the surgical stapling instrument in its extended position. It will be recognized that the surgical stapling instrument 600 may include an outer sleeve (not shown) to facilitate rotation of the staple cartridge housing as described in reference to FIG. 8 .
[0053] Referring now to FIG. 12 , another embodiment of a surgical stapling instrument 700 is illustrated. The surgical stapling instrument 700 in many respects corresponds in construction and function to the previously described surgical stapling instrument 500 of FIG. 9 . Components of the surgical stapling instrument 700 which generally correspond to those components to the surgical stapling instrument 500 of FIG. 9 are designated by like reference numerals in the 700 hundred series. As shown in FIG. 12 , the surgical stapling instrument 700 includes a second staple cartridge housing 705 . It is contemplated that the surgical stapling instrument can have any suitable number of staple cartridge housings. The surgical stapling instrument 600 may include an outer sleeve (not shown) to facilitate rotation of the staple cartridge housing as described in reference to FIG. 8 . It will be recognized that the stapling cartridge housings 704 and 705 of surgical stapling instrument 700 may be retracted and expanded as described in reference to FIGS. 10 and 11 .
[0054] Referring now to FIG. 13 , one embodiment of a surgical hernia patch 800 for implanting within a patient's body space for the repair a hernia is shown. The surgical hernia patch is composed of a top layer 802 and a bottom layer 804 . The top and bottom layer are preferably constructed of a polypropylene material. The top and bottom layer are secured together near their outer edges to hereby form a pocket therebetween. The top layer preferably has a circular opening 806 adapted to receive a balloon of a surgical patch applicator and a staple cartridge housing of a surgical stapling instrument. Preferably, the patch does not contain memory recoil ring that is typically located near the perimeter of the patch.
[0055] FIGS. 14-19 illustrate a variety of fasteners that can be used to attach a surgical hernia patch to the tissue of the patient. The fasteners can be constructed from any suitable material. FIG. 20 shows another embodiment of a fastener 900 that can be used to attach a surgical hernia patch to the tissue of the patient. The fastener 900 can be filled with an adhesive substance, such as bio-glue, to facilitate the attachment of the fastener to the tissue. When the fastener 900 is applied to the tissue, the adhesive substance is forced out of the fastener 900 through at least one aperture or hole 902 and into the surrounding tissue.
[0056] The surgical apparatus and procedures described above allow a hernia to be repaired with less tension, a smaller wound or incision, superior fixation and at a potentially lower cost to the patient than traditional methods. The surgical procedures also allow a surgeon to repair a hernia more quickly than traditional techniques and without the use of sutures.
[0057] Although the present invention has been described in detail by way of illustration and example, it should be understood that a wide range of changes and modifications can be made to the preferred embodiments described above without departing in any way from the scope and spirit of the invention. For example, a fiber optic visualization apparatus can be incorporated into any of the surgical apparatus described above. Thus, the described embodiments are to be considered in all respects only as illustrative and not restrictive, and the scope of the invention is, therefore, indicated by the appended claims rather than the foregoing description. All changes that come within the meaning and range of equivalency of the claims are to be embraced within their scope.
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The present invention relates to devices and methods for the repair of hernia. One method for repairing a hernia the steps of making an incision through a skin layer of a patient near the hernia, creating an entrance into the preperitoneal space above the peritoneum at a location above the hernia, identifying and freeing a hernia sac, creating a pocket in the preperitoneal space, directing a surgical patch down through the incision and into the preperitoneal space, and expanding the surgical patch in the preperitoneal space. The method further includes the steps of inserting a distal end of a surgical fastening device through the incision and into the surgical patch, actuating the surgical fastening device to drive a fastener through the surgical patch and into the tissue of the patient, moving the distal end of the surgical fastening device to another location, actuating the surgical fastening device to drive a second fastener through the surgical patch and into the tissue of the patient, and closing the incision with stitches. One surgical apparatus for repairing a hernia includes a surgical stapling instrument for applying at least one surgical staple to fasten a surgical hernia patch to internal body tissue. The surgical instrument includes a handle assembly have a longitudinal axis. A staple cartridge housing is mounted to the handle assembly and is adapted to receive the at least one staple. The staple cartridge housing is dimensioned for insertion through an incision and has a staple actuator mechanism for applying the at least one staple into tissue. An actuation mechanism is operatively coupled to the staple actuator mechanism to operate the staple actuation mechanism.
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TECHNICAL FIELD
This invention relates to pneumatic impact tools, particularly to reversible self-propelled ground piercing tools.
BACKGROUND OF THE INVENTION
Self-propelled pneumatic tools for making small diameter holes through soil are well known. Such tools are used to form holes for pipes or cables beneath roadways without need for digging a trench across the roadway. These tools include, as general components, a torpedo-shaped body having a tapered nose and an open rear end, an air supply hose which enters the rear of the tool and connects it to an air compressor, a piston or striker disposed for reciprocal movement within the tool, and an air distributing mechanism for causing the striker to move rapidly back and forth. The striker impacts against the front wall (anvil) of the interior of the tool body, causing the tool to move violently forward into the soil. The friction between the outside of the tool body and the surrounding soil tends to hold the tool in place as the striker moves back for another blow, resulting in incremental forward movement through the soil. Exhaust passages are provided in the tail assembly of the tool to allow spent compressed air to escape into the atmosphere.
Most impact boring tools of this type have a valveless air distributing mechanism which utilizes a stepped air inlet. The step of the air inlet is in sliding, sealing contact with a tubular cavity in the rear of the striker. The striker has radial passages through the tubular wall surrounding this cavity, and an outer bearing surface of enlarged diameter at the rear end of the striker. This bearing surface engages the inner surface of the tool body.
Air fed into the tool enters the cavity in the striker through the air inlet, creating a constant pressure which urges the striker forward. When the striker has moved forward sufficiently far so that the radial passages clear the front end of the step, compressed air enters the space between the striker and the body ahead of the bearing surface at the rear of the striker. Since the cross-sectional area of the front of the striker is greater than the cross-sectional area of its rear cavity, the net force exerted by the compressed air now urges the striker backwards instead of forwards. This generally happens just after the striker has imparted a blow to the anvil at the front of the tool.
As the striker moves rearwardly, the radial holes pass back over the step and isolate the front chamber of the tool from the compressed air supply. The momentum of the striker carries it rearwardly until the radial holes clear the rear end of the step. At this time the pressure in the front chamber is relieved because the air therein rushes out through the radial holes and passes through exhaust passages at the rear of the tool into the atmosphere. The pressure in the rear cavity of the striker, which defines a constant pressure chamber together with the stepped air inlet, then causes the striker to move forwardly again, and the cycle is repeated.
In some prior tools, the air inlet includes a separate air inlet pipe which is secured to the body by a radial flange having exhaust holes therethrough, and a stepped bushing connected to the air inlet pipe by a flexible hose. These tools have been made reversible by providing a threaded connection between the air inlet sleeve and the surrounding structure which holds the air inlet concentric with the tool body. See, for example, Sudnishnikov et al. U.S. Pat. No. 3,756,328 and Wentworth et al. U.S. Pat. Nos. 5,025,868 and 5,199,151. The threaded connection allows the operator to rotate the air supply hose and thereby displace the stepped air inlet rearwardly relative to the striker. Since the stroke of the striker is determined by the position of the step, i.e., the positions at which the radial holes are uncovered, rearward displacement of the stepped air inlet causes the striker to hit against the tail nut at the rear of the tool instead of the front anvil, driving the tool rearward out of the hole. Sudnishnikov U.S. Pat. No. 3,616,865 describes a screw-reverse tool wherein exhaust is ported through a central tube that extends in parallel with the compressed air inlet.
Screw reverse mechanisms have obvious limitations. Rotating the hose can become difficult if the tool has traveled far underground, and in any case the tool cannot be switched to reverse rapidly. For this reason, several reversing mechanisms have been proposed which use a second source of compressed air in order to actuate a valve in the tool in order to switch to reverse. See Schmidt U.S. Pat. No. 4,250,972, Spektor U.S. Pat. No. 5,226,487 and Wilson U.S. Pat. No. 5,172,771. A tool described in Kostylev U.S. Pat. No. 4,683,960 provides a central port in the middle of the step to exhaust air sooner than normal when the valve is open and divert compressed air through the central port when the valve is closed, but the valve is operated manually by pulling on a cable. A spring biases the valve to the closed position.
A further reversing mechanism described in Spektor U.S. Pat. No. 5,311,950 reverses upon lowering of the pressure of compressed air. The described tool, however, requires many different parts designed to be assembled in a complex manner.
Despite the availability of many alterative reversing mechanisms, a need remains for a system that is simple, easy to use, reliable, and operable by remote control rather than rotating a hose or pulling on a cable. The present invention addresses this need.
SUMMARY OF THE INVENTION
The present invention provides a pneumatic ground piercing tool having a reversing mechanism than can be operated by remote control but which does not contain a moving valve member inside the tool which become jammed and does not require changing the operating pressure of an air compressor. Such a tool generally includes, as essential components, an elongated tubular housing having a rear opening, a striker disposed for reciprocation within an internal chamber of the housing to impart impacts to a rear impact surface of the anvil for driving the body through the ground, an air distributing mechanism for effecting reciprocation of the striker, a tail assembly mounted in a rear end opening of the housing that secures the striker and air distributing mechanism in the housing, and a reversing mechanism including a supplemental air line capable of supplying compressed air for reverse operation. The supplemental air line is connected to a radial port in the air distributing mechanism. Opening the supplemental air line to the atmosphere produces a short stroke forward mode of operation useful for operations wherein a less forceful impact is desirable.
According to a preferred form of the invention, a reversible pneumatic ground piercing tool of the invention comprises an elongated tool body having a rear opening and a front nose including an anvil. A striker is disposed for reciprocation within an internal chamber of the housing to impart impacts to a rear impact surface of the anvil for driving the tool through the ground, the striker having a rear bearing in sealed, sliding engagement with an inner wall of the tool body.
An air distributing mechanism reciprocates of the striker. The air distributing mechanism includes a rearwardly-opening recess in the striker having one or more radial air flow ports extending through a wall of the recess, and a bushing slidably disposed in the recess in sealed engagement with the recess wall, the bushing having a front external edge and a rear external edge. A first air flow passage extends through the bushing from rear to front in a lengthwise direction, and a first air hose is connected to the first air flow passage for supplying compressed air to the recess to push the striker forward until the radial port in the recess wall passes the front edge of the bushing, at which time compressed air enters a forward pressure chamber ahead of the rear seal bearing of the striker, thereby beginning a rearward stroke of the striker. Travel of the striker continues rearwardly until the radial port in the recess wall passes over the rear edge of the bushing, thereby depressurizing the forward pressure chamber in a known manner.
A tail assembly mounted in a rear end opening of the housing secures the striker and air distributing mechanism in the housing, and receives rearward impacts from the striker when the tool is operating in reverse.
The reversing mechanism includes a second air flow passage extending from the rear of the bushing to a radial port on an exterior surface of the bushing between its front and rear external edges, and a second air hose connected to the second air flow passage for supplying compressed air to the radial port in the bushing. This pressurizes the forward pressure chamber when the radial port in the recess wall moves over the radial port in the bushing, and thereby begins a rearward stroke sooner than if no compressed air had been supplied to the radial port of the bushing.
The invention further contemplates a method of operating an impact boring tool of the invention in forward and reverse modes by selectively opening and closing valves connected to each of the air lines. The valves can be located at the air compressor for ease of operation. Other objects, features and advantages of the invention will become apparent from the following detailed description. It should be understood, however, that the detailed description is given by way of illustration only, since various changes and modifications within the spirit and scope of the invention will become apparent to those skilled in the art from this detailed description.
BRIEF DESCRIPTION OF THE DRAWING
The invention will hereafter be described with reference to the accompanying drawing, wherein like numerals denote like elements, and:
FIG. 1 is a lengthwise sectional view of an impact tool according to the invention taken along the line 1--1 in FIG. 6;
FIG. 2 is enlarged, partial lengthwise sectional view of the rear of the impact tool taken along the line 2--2 in FIG. 6;
FIG. 3 is a cross-sectional view taken along the line 3--3 in FIG. 2;
FIG. 4 is a cross-sectional view taken along the line 4--4 in FIG. 2;
FIG. 5 is a cross-sectional view taken along the line 5--5 in FIG. 1;
FIG. 6 is a rear end view of the tool of FIGS. 1 and 2;
FIG. 7 is a schematic diagram of the tool of FIG. 1 connected to a valve system according to the invention;
FIG. 8 is a schematic diagram of the valves of FIG. 7 positioned for full-power forward operation;
FIG. 9 is a schematic diagram of the valves of FIG. 7 positioned for short-stroke forward operation; and
FIG. 10 is a schematic diagram of the valves of FIG. 7 positioned for reverse operation.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
Referring now to FIGS. 1 to 6, a pneumatic ground piercing tool 10 according to the invention includes, as main components, a tool body 11 which includes a tubular housing 21 and head assembly 22 forming a frontwardly tapering nose, a striker 12 for impacting against the interior of body 11 to drive the tool forward, a stepped air inlet conduit 13 which cooperates with striker 12 for forming an air distributing mechanism for supplying compressed air to reciprocate striker 12, a tail assembly 14 which allows exhaust air to escape from the tool, secures conduit 13 to body 11, and a reversing mechanism 16 built into stepped conduit 13.
Tool body 11 and striker 12 are designed in generally in the same manner as described in Wentworth et al. U.S. patent application Ser. No. 07/878,741, filed May 5, 1992, the entire contents of which are incorporated by reference herein. Striker 12 is disposed for sliding, back-and-forth movement inside of tool body 11 forwardly of conduit 13 and tail assembly 14. Striker 12 comprises a generally cylindrical rod 31 having frontwardly and rearwardly opening blind holes (recesses) 32, 33 respectively therein. Pairs of plastic, front and rear seal bearing rings 34, 36 are disposed in corresponding annular grooves in the outer periphery of rod 31 for supporting striker 12 for movement along the inner surface of housing 21. Annular front impact surface 39 impacts against anvil 23 when the tool is in forward mode, and an annular rear impact surface 41 impacts against front end 45 of tail assembly 14 when the tool is in rearward mode.
A plurality of rear radial ports 42 allow communication between recess 33 and an annular space 43 between striker 12 and housing 21 bounded by seal rings 34, 36. A second set of front radial holes 44 allow communication between space 43 and front recess 32. Annular space 43, holes 44, front recess 32 and the interior space of body 11 ahead of rings 34 together comprise the variable-volume forward pressure chamber 35 of the tool.
Tool body 11 comprises a cylindrical tubular housing 21 having a tapered head assembly 22 which may include a detachable head. Head assembly 22 includes an anvil 23 mechanically secured in a front opening 27 of the body, by, for example, external threads 28 engaged with internal threads 29 formed on the inner periphery of housing 21 near the front opening. Anvil 23 has a forwardly extending central rod 24 which extends in the axial direction of the tool. Anvil 23 preferably comprises a steel cylinder having a central hole 30. Rod 24 has a rear end portion 15 which is retained in central hole 30 of anvil 23. Central hole 30 tapers frontwardly, and rear end portion 15 of rod 24 has a frontwardly tapering outer surface that fits closely within central hole 30. Anvil 23 further has a front, outwardly extending annular flange 40 which engages a step 46 formed on the inner periphery of front end opening 27 of housing 21. Flange 40 engages step 46 and thereby acts as a stop to retain the anvil against excessive rearward movement.
A detachable head 26 is mounted on rod 24 by means of a central opening 47 through which rod 24 extends. Central opening 47 is slightly larger in diameter than rod 24 at a front end of central opening 47 to facilitate sliding movement of the detachable head along rod 24. An inner boss 48 at the rear end of head 26 spaced slightly inwardly from the outer periphery of head 26 fits inside front end opening 27 of housing 21 to help secure head 26 against housing 21 in the proper position.
A releasable locking mechanism 25 secures head 26 over the front opening 27 of housing 21. Releasable locking mechanism 25 includes a ring nut 67 threadedly secured on a front circumferential threaded outer surface portion 68 of rod 24 disposed in front of head 26, whereby head 26 is clamped between housing 21 and nut 67. Mechanism 25 further comprises suitable means for clamp-loading head 26 to the nut 67, such as one or more threaded bolts 69 inserted through threaded holes 70 in nut 67. Holes 70 extend in parallel to the lengthwise axis of the tool and are preferably arranged in a symmetrical formation around the center hole 47 of nut 67.
The ends of bolts 69 engage an annular front surface of detachable head 26, pressing head 26 against housing 21 and thereby stretching rod 24 to provide the clamp-loading effect. The intermediate portion of rod 24 within opening 47 has a slightly reduced diameter to accommodate distortion of rod 24 during stretching. Nose bolts 69 are preferably tightened to exert at least about 100,000 pounds of tensile force on rod 24.
Referring to FIGS. 2 to 6, stepped air inlet conduit 13 includes a tubular bushing 52 and a pair of flexible hoses 53A, 53B. Hoses 53A, 53B, which may be made of rubberized fabric, are secured by couplings 55 to rear end portions of associated fittings 50. Each fitting 50 is threadedly secured in the rear end opening of a lengthwise hole 60A, 60B in the body of bushing 52, thereby forming a pair of air flow passages which supply compressed air to the recess 33 to carry out the forward stroke of the tool in a manner similar to known tools.
The cylindrical outer surface of bushing 52 is inserted into recess 33 in slidable, sealing engagement with the wall thereof. Cavity 33 and the adjoining interior space of stepped conduit 13 together comprise a rear pressure chamber which communicates intermittently with the front, variable pressure chamber by means of holes 42. Bushing 52 may, if needed, have front and rear plastic bearing rings 57A, 57B disposed in annular peripheral grooves to reduce air leakage between bushing 52 and the wall of cavity 33. Bushing 52 may be made of a light-weight material such as plastic.
Reversing mechanism 16 includes a third hose 53C connected to a third hole 60C in bushing 52. A coupling 55 secures hose 53C to a rear end portion of an associated fitting 50 in the same manner as hoses 53A, 53B, except that hose 53C does not communicate with recess 33. Instead, as shown, hole 53C is a blind hole, and a radial port 61 located between front and rear seal bearings 57A, 57B communicates with it. Port 61 is opened and closed by the sliding movement of striker 12 for purposes described hereafter, and may be formed as annular, outwardly opening groove in bushing 52 that communicates with lengthwise hole 60C by means of a single opening 62.
As shown in FIGS. 2-4, hoses 53A-53C are offset from the central axis of the tool and extend in parallel with the tool axis. Although three hoses are shown in the preferred embodiment, hoses 53A, 53B are separated mainly for reasons of design and do not differ in function. A single hose could be used in place of the pair of hoses shown. However, dividing the main air hose in two as shown permits relocation of the hoses in a symmetrical triangular formation that facilitates manufacture and keeps the weight of the tool more evenly balanced.
Tail assembly 14 according to the invention includes a tail nut 71 threadedly coupled to the interior of tool body 11 near the rear end opening thereof, a disk-shaped end cap 72 and a connecting rod 74 which secures bushing 52 at a predetermined position within the tool body. Unlike similar prior tools, tail nut 71 can be a thin-walled tubular sleeve instead of a generally solid steel cylinder with a small central hole. Nut 71 has a number of small, rearwardly opening threaded holes ranged in a circular formation which align with corresponding holes in end cap 72 so that cap 72 can be secured to nut 71 by means of bolts 73 once nut 71 has been threadedly secured inside of tool body 11.
Rod 74 is preferably made of steel and tapers frontwardly as shown so that it has sufficient ability to stretch under the shock of impact. A front end portion of connecting rod 74 is press-fitted into a hole 75 at the center of bushing 52. A rear threaded end portion of connecting rod 74 extends through a hole 76 at the center of cap 72 and is secured by a washer and nut assembly 77.
Although rod 74 may be directly secured to end cap 72, it is preferred to provide a shock dampening isolator 90 between rod 74 and cap 72 to improve the life of rod 74. Isolator 90 includes a pair of front and rear plastic (Delrin) sleeves 92A, 92B mounted on the outside of rod 74 in contact with opposite sides of cap 72 as shown. Rear sleeve 92A is clamped between a flange 93 formed on rod 74 and the rear face of cap 72. Front sleeve 92B is similarly confined between the front face of cap 72 and a washer 94 held in place by a nut 95. A pair of thin metal sleeves 96A, 96B may be secured around the outsides of plastic sleeves 92A, 92B, respectively, to protect sleeves 92A, 92B. Rear sleeve 92B may be omitted if desired, with shortening of rod 74 so that nut 95, with or without washer 94, would be tightenable against the outside of end cap 72.
It has been found that rigid plastic sleeves 92A, 92B effectively protect rod 74 from the axial shocks that are transmitted through the body each time the striker makes a forward or rearward impact. Conventional shock absorbers used to protect the air inlet from shocks transmitted from the tool body, e.g., as shown in U.S. Pat. Nos. 3,756,328 and 5,025,868 cited above, are made of a rubber or a similar elastomeric material. Surprisingly, it has been found according to the present invention that a stronger, more rigid, non-elastomeric sleeve made of a hard plastic can serve as an effective shock absorber with improved durability.
Referring to FIG. 7, to operate the hoses 53A-53C, a valve assembly 80 is provided. Valve assembly 80 includes a main shutoff valve 81 which cuts off all air from the air compressor 82. When valve 81 is open, compressed air flows through a branched passage or fitting 83 through a second valve 84 to each of hoses 53A, 53B, which may be connected to valve 84 by branched passage or fitting 86. A further valve 87 regulates air flow through the other branch of passage 83. When valve 87 is open, compressed air enters a further branched passage or fitting 88 to which hose 53C is connected and thereby enters hose 53C. A fourth valve 89 provided on the other branch of passage 88 isolates passage 88 from an exhaust muffler 91.
Referring now to FIGS. 8 to 10, the tool 10 of the invention can be operated in three different modes depending on the state of each of the air hoses. The latter may be either pressurized, sealed but not pressurized, or open and unpressurized, as described hereafter. In regular forward mode operation, as shown in FIG. 8, valves 81 and 84 are open and valves 87 and 89 are closed. Hoses 53A, 53B are pressurized to drive striker 12 forward so that it impacts against anvil 23 in a manner known in the art to propel the tool forward through the ground. Hose 53C is isolated by valves 87, 89 and remains sealed and unpressurized. By this means, open port 61 has no effect on the tool's operation even though radial ports 42 pass over it during the cycling of the striker 12.
FIG. 9 illustrates the second operating mode, short-stroke forward mode. The configuration is the same as shown in FIG. 8, except that valve 89 is now open. When the striker 12 is moving rearwardly after an impact against anvil 23 in normal forward mode, exhausting of the space 43 does not normally occur until ports 42 pass over the rear edge of bushing 52. Compressed air then flows rearwardly within the tool body and exits through exhaust holes 79 formed in end cap 72 at positions offset from holes 78 through which hoses 53A-53C pass. In short-stroke forward mode, exhausting occurs prematurely because hose 53C is open to the atmosphere, and the rearward momentum of the striker is thereby lessened, shortening the overall stroke.
The reduction in stroke length makes the forward impact less powerful. This is very useful during start-up and other situations where low-power operation is required, such as engaging the head of the tool with a pipe pushing collet. With a full power stroke, the collet or other adapter might become jammed on the tool head, or be damaged. Switching between modes is carried out in a simple manner by opening and closing valve 89 with any need to change the setting of the air compressor. In addition, where valve 89 is of the type that provides continuous adjustment between open, closed, and partially open positions, the operator can use valve 89 to selectively control the forward speed of the tool anywhere between maximum speed (valve closed) and short-stroke forward speed (valve open).
FIG. 10 illustrates the valve configuration for reverse mode operation. Valves 84 and 89 are closed, and valves 81 and 87 are open. Hose 53C is thus pressurized, and hoses 53A, 53B remain sealed and unpressurized. In this state, the point at which the front chamber is pressurized for rearward movement is offset to the rear by the distance from port 61 to the front edge of bushing 52, causing striker 12 to begin the reverse stroke sooner. During the reverse stroke, radial ports 42 become covered by bushing 52 and do not permit communication between recess 33 and outer annular space 43. Since hoses 53A, 53B are sealed, air pressure builds up in recess 33 as the volume of recess 33 decreases due to rearward movement of the striker. When ports 42 pass over the rear edge of bushing 52 and exhausting occurs, the pressure ahead of striker 12 drops, and the force of the pressure in recess 33 then urges the striker forwardly again. The temporary compression of air within recess 33 and hoses 53A, 53B provides an air spring which provides a weak forward stroke to the striker. If needed, a mechanical coil spring could also be provided in recess 33 for a similar purpose with its ends confined by the front end of recess 33 and the front end of bushing 52. If the tool is shut off in the position shown in FIG. 1 so that port 61 is covered by the rear end of striker 12, it will be necessary to start the tool in one of the forward modes before switching to reverse.
The tool of the present invention, when used in combination with the described valve assembly, provides a number of advantages over prior reversing mechanisms. Switching between forward and reverse modes is easily accomplished by opening and closing valves at the compressor with any need to stop the tool and perform manual switching operations, as in a conventional screw reverse. Greater reliability and simplicity are achieved by avoiding the placement of moving valve members and other moving parts in the tool body where such parts would be subject to impacts and shocks during operation. The striker remains the only moving part in the tool itself, and the position of bushing 52 does not change. Further, as noted above, the reversing mechanism of the invention can also provide for a third, short stroke forward mode of operation.
It will be understood that the foregoing description is of preferred exemplary embodiments of the invention, and that the invention is not limited to the specific forms shown. Modifications may be made in without departing from the scope of the invention as expressed in the appended claims.
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A pneumatic ground piercing tool has a reversing mechanism than can be operated by remote control but which does not contain a moving valve member inside the tool which become jammed. Such a tool generally includes, as essential components, an elongated tubular housing having a rear opening, a striker disposed for reciprocation within an internal chamber of the housing to impart impacts to a rear impact surface of the anvil for driving the body through the ground, an air distributing mechanism for effecting reciprocation of the striker, a tail assembly mounted in a rear end opening of the housing that secures the striker and air distributing mechanism in the housing, and a reversing mechanism including a supplemental air line capable of supplying compressed air for reverse operation to a radial port in the air distributing mechanism. Opening the supplemental air line to the atmosphere produces a short stroke forward mode of operation useful for operations wherein a less forceful impact is desirable.
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This is a continuation of application Ser. No. 6/939,597 filed Dec. 9, 1988, now abandoned which is a division of co-pending application Serial No. 744,363, filed June 13, 1985 now abandoned.
The present invention relates to reinforcing filament bundles in the form of elongated granules and to their use in dispersing fibers in thermoplastic resins during injection molding processes.
BACKGROUND OF THE INVENTION
Fiber filled plastic compounds suitable for injection molding have become widely used. The fibers impart many valuable characteristics to the injection molded articles, foremost of which are high dimensional stability, high modulus of elasticity, high resistance to distortion by heat, high tensile strength, unusually high flexural modulus and low shrinkage during curing. Glass-reinforced thermoplastic injection molding compounds and injection molding processes employing them are described in Bradt, U.S. Pat. No. 2,877,501. The technology of the Bradt patent has subsequently been extended. In addition to the styrene resins, styrene-acrylonitrile copolymer resins and styrene-butadiene copolymer resins described therein, numerous other injection-moldable thermoplastic resins, such as polycarbonate resins, acrylonitrile-butadiene-styrene terpolymer resins, poly (ethylene terephthalate) resins, polysulfone resins, polyphenylene ether resin, nylon resins, and the like, are effectively reinforced by glass fibers. Moreover, instead of glass fibers, subsequently developed commercial products are reinforced with filaments of carbon fibers, graphite fibers, aramid fibers, stainless steel filaments and others, as well as mixtures of any of the foregoing, many such products stemming directly from the technology disclosed in the above-mentioned U.S. Pat. No. 2,877,501. Such technology involves providing elongated granules, each of the granules containing a bundle of elongated reinforcing filaments extending generally parallel to each other longitudinally of the granule and a thermoplastic molding composition surrounding and permeating the bundle. In the process of injection molding, such granules are forced into a mold, wherein the filaments will be dispersed and produce molded articles with improved properties in comparison with the molded thermoplastic alone.
The above-mentioned U.S. Pat. No. 2,877,501, discloses pellets comprising 15-60 wt. % glass in thermoplastic resin, e.g., polystyrene. This corresponds to 8.1%-42.9% of filaments by volume and correspondingly 91.9-57.1% by volume of resin. Current processes for making such prior art filament-filled granules require a compounding/pelletizing step, in which the thermoplastic material is mixed with filaments, usually chopped bundles of filaments, and usually in an extruder, then the extrudate is chopped into molding granules. Such equipment is not readily available to the molder, and a number of specialty compounders have established businesses in which fibers from one source, and thermoplastics from another source are formulated into granules in drums or truckloads for sale to molders. It would be desirable to by-pass such compounders and permit molders to feed mixtures of thermoplastics and fibers directly into the molding press hopper achieving fiber dispersion by shear forces at the screw, nozzle, check valve, runners, gates, etc., in the injection molding machine. It would also be desirable to use, in comparison with the prior art, much less resin in the pellets, e.g., 2.5-32.5% by volume (instead of 57.1-91.9%) and much higher filament loadings, e.g., 67.5-97.5% by volume (instead of 8.1-42.9% by volume). However, until the present invention, this has not been possible because the fiber or filament bundles separate during chopping and tumbling with the reduced volume fractions of resin. There is also a tendency for the resin to degrade if the temperature is raised to lower viscosity and enhance dispersion. Moreover, individual fibers can become airborne and cause problems in handling.
The improved elongated granule of the present invention solves such problems by substituting for the thermoplastic matrix separating and coating the fiber bundles, in the prior art, a much thinner layer of an efficient thermoplastic adhesive, which acts as a binder. As will be shown, such a judiciously selected binder will hold the fiber bundle together sufficiently to prevent broken bundles during chopping into elongated pellets and tumbling with the resin to be reinforced, and then the adhesive binder will readily break down in the presence of molten resin and thereafter not interfere with fiber dispersion, or degrade the resin properties, or constitute an environmental hazard.
As will be seen, the molding process itself can be used to disperse the resin uniformly throughout the molded part thus avoiding the compounding/pelletizing step.
As a decidedly unexpected advantage, and to further demonstrate the importance of the present invention, greater and more uniform dispersions of the fibers are achieved. It has been found that when using electrically conductive fibers, such as nickel coated graphite fibers, superior electromagnetic shielding is obtained at equal load levels (compared with compounded pellets), providing better shielding at one-half the cost, and, in comparison with the use of conductive, e.g., silver, paint there is much less or no secondary finishing with equivalent or better shielding, for superior physical properties, and superior long term reliability.
DESCRIPTION OF THE DRAWING
In the drawing,
FIG. 1 is a somewhat idealized isometric view, on an enlarged scale, of a molding granule of the prior art;
FIG. 2 is a somewhat idealized, fragmental cross-section of a molding granule of the prior art on a still further enlarged scale;
FIG. 3 is a somewhat idealized isometric view, on an enlarged scale, of a molding granule according to this invention, showing closer packing and no overcoat;
FIG. 4 is a somewhat idealized, fragmental cross-section of a molding granule of this invention on a still further enlarged scale;
FIG. 5a is a semi-schematic diagram showing a preferred way of making the elongated molding pellets of this invention; and
FIG. 5b is a semi-schematic drawing illustrating the way in which the pellets of this invention are mixed and molded into shaped articles.
SUMMARY OF THE INVENTION
In accordance with the invention, there are provided injection molding compounds comprising elongated granules, each of the granules containing a bundle of elongated reinforcing filaments extending generally parallel to each other longitudinally of the granule and substantially uniformly dispersed throughout the granule in a thermally stable, film forming thermoplastic adhesive which substantially surrounds each filament.
Also contemplated by the invention are mixed injection molding compositions comprising:
(i) thermoplastic resin molding granules; and
(ii) elongated granules comprising 67.5-97.5% by volume of reinforcing filaments extending generally parallel to each other longitudinally of each of the granules and substantially uniformly dispersed throughout the granule in from 2.5 to 32.5% by volume of a thermally stable, film forming thermoplastic adhesive, the amount of component (ii) in the composition being sufficient to provide 5-60% by weight of the filaments per 100% by weight of (i) plus (ii).
It is a further feature of the invention to provide a method of manufacturing an injection molding compound comprising the steps of continuously passing reinforcing filaments through one or more baths of a thermally stable, film forming thermoplastic adhesive in a solvent, e.g., water, to impregnate the filaments, passing the impregnated filaments through a sized opening to remove any excess adhesive, passing the impregnated filaments into a heating zone first to evaporate the solvent and then to flux the thermoplastic adhesive, and withdrawing the treated filaments from the heating zone and thereafter chopping them into elongated granules, whereby there are produced granules comprising 67.5-97.5% by volume of reinforcing filaments extending generally parallel to each other longitudinally of the granule, substantially uniformly dispersed throughout said granule in from 2.5-32.5% by volume of a thermally stable, film forming thermoplastic adhesive which substantially surrounds each said filament.
In still another aspect, the present invention contemplates as an improvement in the process of injection molding, the step of forcing into a mold an injection molding composition comprising a blend of:
(i) thermoplastic molding granules; and
(ii) an amount effective to provide reinforcement of elongated granules, each of the granules containing a bundle of reinforcing filaments extending generally parallel to each other longitudinally of the granule substantially uniformly dispersed in a thermally stable, film forming thermoplastic adhesive which substantially surrounds each said filament.
DETAILED DESCRIPTION OF THE INVENTION
Referring to the drawing, FIGS. 3 and 4, each filament contained in the injection molding granule is surrounded by and the bundle is impregnated by the thermally stable, film forming thermoplastic adhesive. The pellet itself may be of cylindrical or rectangular or any other cross-sectional configuration, but preferably is cylindrical. The length of the granules can vary, but for most uses, 1/8 inch-3/4 inch will be acceptable and 1/8 inch-1/4 inch will be preferred. The differences between the pellets of this invention and those of the prior art can be seen by comparison of FIG. 1 with FIG. 3 and FIG. 2 with FIG. 4, respectively. Unlike the prior art (FIGS. 1 and 2) the pellets of this invention have close-packed filaments and the thermoplastic adhesive jacket is substantially dispersed upon contact with hot molten thermoplastic in the present invention. On the other hand, the prior art pellets will not readily separate into reinforcing filaments because of interference by the relatively thick jacket of thermoplastic resin.
Instead of using a lot of resin to impregnate the fiber bundle and surround it, as is done in the prior art, it is essential to use an adhesive efficient for the purposes of the invention, and that is to bind a high proportion of filaments into each elongated granule and maintain them throughout the chopping process. The adhesive preferably will be used also in an amount which is not substantially in excess of that which maintains the fiber bundle integrity during chopping. This amount will vary depending on the nature of the fibers, the number of fibers in the bundle, the fiber surface area, and the efficiency of the adhesive, but generally will vary from 2.5 to 32.5% and preferably from 5 to 15% by volume of the granule.
For uniform adhesive pick up on the fibers in the bundle it is preferred to use a small, but effective amount of a conventional coupling agent, which also enhances bonding to numerous different substrates. Aminosilanes are preferred for this purpose, the only requirement being that they be miscible with any solvent system used for impregnation and compatible with the thermoplastic film forming adhesive. A preferred aminosilane is N (2-aminoethyl)-3-aminopropyltrimethoxysilane (available from Dow-Corning corp. under the trade designation Z 6020). Also suitable are gamma-methacryloxypropyltrimethoxysilane and gamma-chloropropyltrimethoxysilane.
It is a preferred feature of the invention also to include in the adhesive a small, but effective amount of a plasticizer. This is helpful to soften and reduce the melting point (glass transition temperature, Tg) of the adhesive, and to facilitate blending and molding with the lower melting thermoplastics, e.g., acrylonitrile-butadiene-styrene (ABS) terpolymer resins. As with the coupling agent, the only critical requirements are that the plasticizers be miscible with any solvent system used for impregnation and compatible with the film forming adhesive.
Careful consideration should be given to selection of the film forming thermoplastic adhesive, subject to the above-mentioned parameters. Some adhesives are more efficient than others, and some, which are suggested for use as fiber sizings in the prior art will not work. For example, poly(vinyl acetate) and poly(vinyl alcohol), the former being suggested by Bradt in U.S. Pat. No. 2,877,501, as a sizing, do not work herein because, it is believed, thermosetting or cross linking occurs and this operates to prevent rapid melting and complete dispersion in the injection molding machine. While such materials are suitable for the resin rich compounded granules used in the the Bradt patent, they are unsuitable herein.
Much preferred are a class of resins comprising poly (C 2 -C 6 alkyl oxazolines). These are somewhat structurally related to N,N-dimethylformamide (DMF) and have many of its miscibility properties. A readily available such polymer is poly(2-ethyl oxazoline), Dow Chemical Co. PEOx. This can also be made by techniques known to those skilled in this art. Poly(2-ethyl oxazoline) is a thermoplastic, low viscosity, water-soluble adhesive. It can be used in the form of amber-colored and transparent pellets 3/16" long and 1/8" diameter. Typical molecular weights are 50,000 (low); 200,000 (medium) and 500,000 (high). Being water soluble, it is environmentally acceptable for deposition from aqueous media. It also wets the fibers well because of low viscosity. It is thermally stable up to 380° C. (680° F.) in air at 500,000 molecular weight. When used as an adhesive for fiber bundles, it does not fracture appreciably during chopping to minimize free filaments from flying about, which can be a safety hazard. When blended with pellets of a thermoplastic resin system, this material will melt readily allowing complete dispersion of the fibers throughout the resin melt while in a molding machine. However, pellets bound with this thermoplastic adhesive are indefinitely stable with the resin pellets during blending, and don't break apart prematurely.
As a result of a number of trials, the invention as currently practiced provides optimum results when the following guidelines are adhered to:
The fiber type can vary, any fiber being known to be useful as a filler or reinforcement in a resin system can be used. Preferred fibers are carbon or graphite fibers, glass fibers, aramid fibers, stainless steel fibers, metal coated graphite fibers, or a mixture of any of the foregoing.
The preferred thermoplastic adhesive comprises poly(ethyloxazoline), having a molecular weight in the range of about 25,000 to about 1,000,000, preferably 50,000-500,000, most preferably about 50,000.
It is preferred that the adhesive be deposited onto the filaments from a solvent system which can comprise any polar organic solvent, e.g., methanol, or mixture of such solvents, or water, alone, or in admixture. Acceptable bath concentrations for the thermoplastic adhesive can vary but is generally in the range of 2.5-12% by weight, preferably 2.5-6%, and especially preferably 2.5-4% by weight.
If a plasticizer is used, this too can vary in type and amount, but generally a poly(C 2 -C 6 alkylene glycol) is used, such as a poly(ethylene glycol) or poly(propylene glycol), e.g., a CARBOWAX® from Union Carbide Corp. Acceptable molecular weights range from 200 to 600, with 200-400 being preferred and 300 most preferred. Bath concentrations can range from 0.1 to 0.5%, preferably from 0.3 to 0.5%, by weight.
If a coupling agent is used, this will preferably be an aminosilane, preferably N-(2-aminoethyl)-3-aminopropyltrimethoxysilane. The bath concentration of the coupling agent can vary widely, but in general is from 0.1 to 1.0% by weight, preferably 0.25 to 0.75% by weight, most preferably 0.5% by weight.
The amount of non-filament material in the filament-containing granules of the invention will vary, but, in general, will range from 2.5 to 32.5% by volume with any fiber, preferably from 5 to 15% by volume.
The non-filament content in the elongated fiber-containing pellets, by component, is as follows, 60-100% by weight of adhesive, 80% preferred; 20-0% of plasticizer, 8% preferred, and 40-0% of coupling agent, 12% preferred.
The length of the elongated granule will generally range from 1/8 to 3/4 inch, preferably from 1/8 to 1/4 inch. The diameters of each elongated granule can vary, depending primarily on the number of filaments and the thickness of each filament in the bundle. Typically, thicknesses will vary from about one-forty-eighth to about three-sixteenths inch in diameter. Preferably, the diameter will be in the range of from about one-thirty-second to about one-eighth inches in diameter.
Numerous thermoplastic resins can be employed with the elongated granules of the present invention. In general any resin that can be injection molded and that can benefit from a uniform dispersion of fibers can be used. For example polystyrene, styrene/acrylic acid copolymer, styrene/acrylonitrile copolymer, polycarbonate, poly (methyl methacrylate) poly(acrylonitrile/butadiene/styrene), polyphenylene ether, nylon, poly(1,4-butylene terephthalate), mixtures of any of the foregoing, and the like, can be used.
It is preferred to manufacture the injection molding composition of this invention by a continuous process. A suitable apparatus is shown in FIG. 5a. Typically, bundles of filaments, such as graphite fiber tows or metal coated graphite fiber tows, 3,000 to 12,000 filaments per bundle, glass yarns, 240 filaments to a strand, or stainless steel tow, 1159 filaments per bundle, are drawn from storage roller 2 and passed through one or more baths 4, containing the thermally stable, film forming thermoplastic adhesive in a solvent medium, e.g., water, to impregnate the filaments, then through die 6, to control pick up. The impregnated filaments thereafter are passed into a heating zone, e.g., oven 8, to evaporate the solvent, e.g., water and then to flux the thermoplastic adhesive. The treated filaments 10 are withdrawn from the heated zone, transported to chopper 12 and cut into fiber pellets illustratively varying between 1/8-1/4" according to the requirements of the particular apparatus. The pellets are then stored in a suitable container 14 for subsequent use. Any coupling agent and/or plasticizers can be deposited from separate baths, but conveniently they are included in a single bath with the adhesive. It will be observed that this procedure results in the orientation of the reinforcing fibers along one axis of the granule.
To carry out the molding method of the present invention, a flow diagram in the general form illustrated in FIG. 5b is preferably employed. Fiber pellets 16 are mixed with resin pellets 18 to produce a blended mixture 20. This is added to conventional hopper 20 on molding press 24. When passing through cylinder 26, prior to being forced into mold 28 a uniform dispersion of the fibers is accomplished. Removal of molded article 30 provides a fiber reinforced item produced according to this invention.
It is understood that other plasticizers, mold lubricants, coloring agents, and the like, can be included, and that the amount of reinforcement in the components can be varied according to well-understood techniques in this art.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
The following are examples of the present invention but are not to be construed to limit the claims in any manner whatsoever. The electrical mesaurements (Shielding effectiveness (SE) values in decibles ) are averages usually of four samples.
EXAMPLE 1
Using an apparatus of the type generally shown in FIG. 5a a bath comprising the following is formulated:
______________________________________Component % by weight______________________________________poly(ethyl oxazoline), MW 50,000 4.0poly(ethylene glycol), MW 300 0.3N-(2-aminoethyl)-3-amino- 0.4propyltrimethoxy-silaneWater 95.3______________________________________
A tow of continuous graphite fibers (12,000 count) each of which has an electroplated nickel coating thereon is led through the bath. The graphite filaments each average about 7 microns in diameter. The nickel-coating thereon is approximately 0.5 microns in thickness. The nickel coated graphite tows are prepared by continuous electroplating in accordance with the procedure described in European Patent Application No. 0088884 (published September 21, 1983). After passing out of the coating bath the treated fibers are drawn through 60 mil die then passed through an oven at about 300° F. The impregnated filaments then are chopped to 1/4" lengths and there are produced elongated granules of approximately 1/16" in diameter of cylindrical shape and form. The non-filament material content is 9% by volume.
EXAMPLE 2
Using the process generally shown in FIG. 5b, sufficient of the elongated pellets produced in Example 1 are blended with pellets of a thermoplastic molding resin composition comprising poly(2,6-dimethyl-1,4-phenylene ether) and high impact polystyrene (HIPS) (General Electric Co. NORYL® N-190) to provide 10 weight percent cf nickel-coated graphite filaments in the blend. The blended mixture is molded in an injection molding press into work pieces suitable for physical and electrical testing. The electromagnetic shielding effectiveness (SE) and EMI attenuation are measured to determine dispersion efficiency for comparison with the prior art at the same filament loading.
EXAMPLES 3 AND 4
The procedure of Example 2 is repeated, substituting sufficient of the elongated pellets of Example 1, respectively, to provide 15% and 20% by weight of nickel-coated graphite filaments in the blend, and
For comparison purposes, molding pellets according to the prior art are prepared, containing nickel-coated graphite dispersed in an extruder to a level of 10, 15 and 20 weight percent in polyphenylene ether/styrene resin, and workpieces suitable for measuring SE are produced.
The Electro-Metrics Dual Chamber test fixture was used according to ASTM ES7-83 to measure the shielding effectiveness (SE) of the compositions of Examples 2-4 of this invention, for comparison with extrusion compounded pellets of the prior art. The results are set forth in Table 1:
TABLE 1______________________________________Shielding Effectiveness Polyphenylene Ether/HIPS Containing Nickel-Plated Graphite FilamentsEXAMPLE 2 2A* 3 3A* 4 4A*______________________________________Composition (parts by weight)Polphenylene ether/high 90 90 85 85 80 80impact polystyreneNickel-coated graphite -- 10 -- 15 -- 20chopped filaments, 1/8"Elongated film bonded 10 -- 15 -- 20 --bundles (Examples 2-4)Shielding Effectiveness,decibels @30 MHz 34 13 59 40 69 52100 MHz 27 12 50 29 62 36300 MHz 34 30 61 32 73 501000 MHz 17 12 64 14 75 30______________________________________ *Controls
These data are especially noteworthy because each 10 dB of attenuation represents an order of magnitude. Therefore, a difference of 20 dB between two readings is actually a factor of 100 and a difference of 50 dB is a factor of 100,000. The data for the compositions made using elongated granules of this invention are far superior to the compounded plastic/fiber of the control. The 10% NCG data of Examples 2 is as good as the 15% compounded comparison 3A* data and the 15% data of Example 3 is better than the 20% compounded comparison 4A* data. Such differences are significant--as much as 50 dB.
EXAMPLE 5
The procedure of Example 2 is repeated substituting for the thermoplastic resin pellets, pellets comprising poly(acrylonitrile/butadiene/styrene) (Borg Warner CYCOLAC® KJB) resin and plaques suitable for measuring SE effect are molded.
EXAMPLE 6
The procedure of Example 2 is repeated but poly(bisphenol-A carbonate) resin pellets (General Electric LEXAN® 920) are substituted, and plaques suitable for measuring SE are prepared.
EXAMPLES 7-9
The procedure of Example 1 is repeated, substituting for the nickel coated graphite tows, tows of uncoated graphite fibers (Example 7), glass fibers, 240 filaments/strand (Example 8), and stainless steel fiber tows comprising 1159 count filaments each measuring about 7 microns in diameter (Example 9). Elongated granules according to this invention were prepared, comprising about 85 to 95% by volume of the respective filaments.
EXAMPLE 10
The procedure of Example 2 is repeated but poly(bisphenol-A carbonate) resin pellets are substituted, and elongated fiber pellets of stainless steel fibers (Example 9) are substituted to provide 15% by weight. Plaques for measuring SE properties and test pieces for strength testing were preferred.
The Shielding Effectiveness of the compositions molded from the mixtures of Examples 5, 6 and 10 were measured by ASTM ES7-83 as described above, compared with compositions melt blended on a compounding extruder, as in the prior art, before injection molding, and the data are set forth in Table 2:
TABLE 2______________________________________Shielding Effectiveness of Polycarbonate andABS Resins Containing Nickel Coated Graphiteand Stainless Steel FilamentsExample 5 5A* 6 6A* 9______________________________________Compositions (parts by weight)poly(bisphenol-A) carbonate -- -- 90 90 90poly(acrylonitrile/butadiene/ 90 90 -- -- --styrene)nickel coated graphite 10 -- 10 -- --elongated film bondedbundlesnickel coated graphite -- 10 -- 10 --chopped towsstainless steel elongated -- -- -- -- 15film bonded bundlesShielding Effectiveness,decibels @30 MHz 21 18 30 13 35100 MHz 19 17 29 12 25300 MHz 38 35 40 34 371000 MHz 12 12 20 10 16______________________________________ *Melt blended on a compounding extruder before injection molding.
Again, significant enhancement of SE data are obtained after using the bonded bundles according to the present invention.
EXAMPLES 11-14
The general procedure of Example 2 is used to formulate and mold physical strength test pieces from polycarbonate resin and the film bonded pellets according to this invention of Examples 1, 7, 8 and 9. The compositions used and the results obtained are set forth in Table 3:
TABLE 3______________________________________Compositions of Aromatic Polycarbonate andFilm-Bonded Pellets of Nickel Coated Graphite,Graphite, Glass and Stainless Steel FilamentsEXAMPLE 11 11A* 11B* 12 13 14______________________________________Composition (parts byweight)poly(bisphenol-A carbonate) 85 100 85 85 85 85nickel-coated graphite 15 -- -- -- -- --fiber film bonded pellets(Example 1)nickel-coated graphite -- -- 15 -- -- --chopped fibersgraphite fiber film bonded -- -- -- 15 -- --pellets (Example 7)Glass fiber film bonded -- -- -- -- 15 --pellets (Example 8)Stainless steel fiber film -- -- -- -- -- 15bonded pellets (Example 9)Properties**Tensile Strength (ksi) 13.1 8.5 11.1 16.6 11.6 8.6Tensile Modulus (Msi) 1.06 0.32 0.97 1.62 0.73 0.48______________________________________ *Control **Control -- melt blended on a compounding extruder before injection molding. ***Test method ASTM D638.
The tensile strength and modulus of the molded articles are very favorably influenced by using film bonded pellets according to the present invention.
In making the elongated pellets of this invention, other fibers can be substituted, e.g., aramid fiber, e.g., KEVLAR® fiber, ceramic fiber, or combinations of any of the foregoing such fibers. Aramid fiber is particularly interesting because it is virtually impossible to chop and blend with thermoplastic resins because it frays and birdnests. When prepared in the form of coated bundles herein, aramid fiber chops very well and mixes easily.
The foregoing patents and publications are incorporated herein by reference.
Many variations of the present invention will suggest themselves to those skilled in the art in light of the foregoing detailed description. All such obvious variations are within the full intended scope cf the appended claims.
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Elongated granules of reinforcing fibers extending generally parallel to each other longitudinally of the granule substantially uniformly dispersed throughout a thermally stable, readily melting, film forming thermoplastic adhesive, providing complete dispersion of the fibers during an injection molding cycle, conserving physical properties and providing significantly better EMI shielding than prior art extruder compounded resin/fiber blends.
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CROSS REFERENCE TO RELATED APPLICATIONS
[0001] The present application claims the benefit of and priority to U.S. Provisional Patent Application Ser. No. 61/752,295, filed Jan. 14, 2013, and the contents of which are hereby incorporated by reference in its entirety.
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
[0002] Not applicable.
REFERENCE TO APPENDIX
[0003] Not applicable.
BACKGROUND OF THE INVENTION
[0004] The present invention relates to oil well pumps and more particularly to an improved hydraulic oil well pump that is electronically controlled using limit or proximity switches to control a valving arrangement that eliminates shock or excess load from the pumping string or sucker rod during pumping, and especially when changing direction of the sucker rod at the bottom of a stroke. In one embodiment, a time delay halts the movement of the sucker rod or pumping string to allow accumulation of oil in a slow following well. In another embodiment, the pumping string rapidly falls to the bottom of the stroke in order to shake or jar debris from the string.
BRIEF SUMMARY OF THE INVENTION
[0005] The present invention provides a hydraulic oil well pumping apparatus. The system of the present invention utilizes a hydraulic cylinder having a piston or rod that is movable between upper and lower piston positions. A pumping string or sucker rod extends downwardly from the piston, the pumping string or sucker rod being configured to extend into an oil well for pumping oil from the well.
[0006] A prime mover such as an engine is connected to a compensating type hydraulic pump.
[0007] A directional control valve moves between open flow and closed flow positions. A hydraulic flow line connects the pump and the hydraulic cylinder.
[0008] Electronic controls are provided that control movement of the piston as it moves between the upper and lower positions.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS
[0009] For a further understanding of the nature, objects, and advantages of the present invention, reference should be had to the following detailed description, read in conjunction with the following drawings, wherein like reference numerals denote like elements and wherein:
[0010] FIG. 1 is an exploded, elevation view of the preferred embodiment of the apparatus of the present invention;
[0011] FIG. 2 is an elevation view of the preferred embodiment of the apparatus of the present invention;
[0012] FIG. 2A is a partial elevation view of the preferred embodiment of the apparatus of the present invention;
[0013] FIG. 3 is a sectional view of the preferred embodiment of the apparatus of the present invention, taken along lines 3 - 3 of FIG. 2 ;
[0014] FIGS. 4A , 4 B and 4 C are fragmentary, elevation views of the preferred embodiment of the apparatus of the present invention illustrating operation of the apparatus;
[0015] FIG. 5 is a partial perspective view of the preferred embodiment of the apparatus of the present invention; and
[0016] FIGS. 6-7 are schematic diagrams of the preferred embodiment of the apparatus of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
[0017] The Figures described above and the written description of specific structures and functions below are not presented to limit the scope of what Applicants have invented or the scope of the appended claims. Rather, the Figures and written description are provided to teach any person skilled in the art to make and use the inventions for which patent protection is sought. Those skilled in the art will appreciate that not all features of a commercial embodiment of the inventions are described or shown for the sake of clarity and understanding. Persons of skill in this art will also appreciate that the development of an actual commercial embodiment incorporating aspects of the present inventions will require numerous implementation-specific decisions to achieve the developer's ultimate goal for the commercial embodiment. Such implementation-specific decisions may include, and likely are not limited to, compliance with system-related, business-related, government-related and other constraints, which may vary by specific implementation, location and from time to time. While a developer's efforts might be complex and time-consuming in an absolute sense, such efforts would be, nevertheless, a routine undertaking for those of skill in this art having benefit of this disclosure. It must be understood that the inventions disclosed and taught herein are susceptible to numerous and various modifications and alternative forms. Lastly, the use of a singular term, such as, but not limited to, “a,” is not intended as limiting of the number of items. Also, the use of relational terms, such as, but not limited to, “top,” “bottom,” “left,” “right,” “upper,” “lower,” “down,” “up,” “side,” and the like are used in the written description for clarity in specific reference to the Figures and are not intended to limit the scope of the invention or the appended claims.
[0018] FIGS. 1-7 show generally the preferred embodiment of the apparatus of the present invention designated generally by the numeral 10 .
[0019] Oil well pump 10 provides a reservoir 11 for containing hydraulic fluid. A prime mover 12 such as an engine is provided for driving a compensating pump 13 . The pump 13 is used to transmit hydraulic pressure, pressurized hydraulic fluid received from reservoir 11 via flow line 33 to a hydraulic cylinder or petroleum lift cylinder 14 . Lift cylinder 14 can be a Parker (www.parker.com) model GG699076A0. The hydraulic lift cylinder 14 includes a cylinder body 15 having a hollow interior 16 .
[0020] A cylinder rod 17 is mounted in sliding or telescoping fashion to the cylinder body 15 extending into the interior 16 of cylinder body 15 . The cylinder rod 17 has an upper end portion 18 and a lower end portion 19 . During use, the lower end portion 19 extends below cylinder body 15 as shown in FIGS. 1-4C and 6 - 7 .
[0021] In FIG. 1 , the lower end portion 19 of cylinder rod 17 is attached with coupling 20 to a pumping string or sucker rod 21 . The pumping string or sucker rod 21 is comprised of a number of joints, connected end to end. A pumping part of the sucker rod 21 is generally positioned next to a perforated zone of the well. Such a pumping string 21 or sucker rod 21 is known in the art and is used to pump oil from an oil well as the sucker rod 21 moves up and down.
[0022] The lift cylinder 14 is mounted upon Christmas tree 22 . The Christmas tree 22 is mounted at the well head of an oil well at the upper end portion of well pipe 23 . A suitable structural frame 38 can be used for supporting hydraulic cylinder 14 and its cylinder rod 17 above Christmas tree 22 as shown in FIGS. 1-4C and 6 - 7 .
[0023] A plurality of proximity or limit switches 24 , 25 , 26 are provided. Switches 24 , 25 , 26 can be for example those manufactured by Turck Company, model number N120-CP40AP6X2/510. As shown in FIGS. 2-2A , these proximity or limit switches 24 , 25 , 26 can be mounted to frame 38 . During use, these proximity or limit switches 24 , 25 , 26 can be used to sense the position of the lower end portion 19 of cylinder rod 17 and then send an electronic signal to the controller 39 (commercially available), then the controller 39 sends a signal to the manifold 35 that includes directional valve 28 , proportioning valve 31 , and ventable relief valve 37 (e.g. Parker Sterling model no. AO4H3HZN).
[0024] Hydraulic fluid flow lines are provided for transmitting hydraulic fluid under pressure to hydraulic lift cylinder 14 via flow lines 27 , 29 . Directional valve 28 receives flow from flow line 29 . Flow line 27 extends between directional valve 28 and cylinder 14 . To initiate operation, pump 13 transmits fluid flow through the manually vented relief valve 37 thus removing pressure from the system prior to start up. When the engine or prime mover 12 is started, it activates the hydraulic pump 13 , flow still initially traveling through the relief valve 37 and flow line 34 to reservoir 11 .
[0025] The cycle of operation begins by vent closure of valve 37 so that oil flowing in flow line 29 now travels to directional valve 28 . At about the same time, the directional valve 28 is energized so that oil under pressure is directed via flow line 27 to hydraulic lift cylinder 14 body 15 and its hollow interior 16 . The cylinder rod 17 will then elevate, lifting the pumping string 21 or sucker rod 21 with it (see FIG. 2 ). In one embodiment, a delay cycle is provided wherein the cylinder rod 17 and pumping string 21 remain in this elevated position for a selected time interval. This time delay in the elevated position is used when the well is slow flowing. A well can be slow flowing when the oil is more viscous or if the well is an older well with a lesser volume of available oil to pump. The delay cycle must first be turned on via the HMI (human machine interface). Once this is done the operator can adjust the amount of time that the cylinder pauses (delays) at the top of the stroke. The amount of time of the delay may be 0 seconds to 65000 seconds (18 hours). This can be changed if needed. The delay cycle offers several benefits. The delay cycle allows gas separation at the down hole pump intake—resulting in greater pump efficiency. The delay cycle minimizes rod reversal effect, which allows the rod time to relax before starting its downward stroke. The delays also allows the tubing fluid load above the travel valve time to equalize with the standing valve—resulting in reduced fluid pound effect at the down hole rod pump.
[0026] Frame 38 carries the plurality of proximity or limit switches 24 , 25 , 26 . When the cylinder rod 17 reaches the top of its stroke, the proximity switch 24 (which is an uppermost proximity switch) senses the position of coupling 20 and energizes the directional valve 28 so that it closes the flow line 29 and flows through proportional valve 31 . Valve 31 is a manual proportional valve with flow check for restricted flow on return of hydraulic oil to the reservoir, thus allowing a restricted flow to control the rate of descent of cylinder rod 17 . Because the pump 13 is a compensating pump, it continues to run but does not continue to pump fluid. It can be set to halt fluid flow at a certain pressure value (e.g. 3000 psi, or 210.92 kgf/cm2) which can be set by design depending upon the weight of sucker rod 21 . In other words, pump 13 is volume compensating and pressure responsive. Such a compensating pump is manufactured by Parker such as their model no. P1100PSO1SRM5AC00E1000000.
[0027] When the directional valve 28 is used to close flow line 29 , the compensating pump 13 continues to rotate with the engine 12 but no longer pumps fluid in flow line 29 . The directional valve 28 opens drain line 30 at about the same time that line 29 is closed. Fluid in hydraulic cylinder 14 now drains via flow lines 27 and 30 through proportioning valve 31 and cylinder rod 17 descends relative to cylinder body 15 . The hydraulic fluid draining from cylinder body 15 interior 16 continues to flow via flow lines 27 and 30 through proportioning valve 31 and cooler 36 and then into flow line 32 which is a drain line to reservoir 11 . The flow line 32 can be provided with oil cooler 36 (e.g. Thermal Transfer model BOL-8-1-9) and an oil filter (e.g. Parker model no. RF2210QUP35Y9991) if desired.
[0028] Since pressure no longer forces cylinder rod 17 upwardly, it begins to drop (see FIGS. 4A and 7 ). As it drops relative to lift cylinder body 15 , coupling 20 will meet a second proximity or limit switch 25 which is below limit switch 24 (see FIGS. 2 , 4 A, 4 B, 4 C). The limit switch 25 is closer to the lower end portion (for example, 1 foot, or 0.30 meters) of cylinder body 15 than to upper end portion of body 15 . When the coupling 20 reaches proximity or limit switch 25 , in one embodiment ( FIG. 2A ) it signals the directional valve 28 that it should switch to allow the flow of fluid to travel through the proportioning valve 31 via flow lines 27 , 30 .
[0029] The proportioning valve 31 is a manual proportioning valve with flow check for restricted flow on return of hydraulic oil to the reservoir. When the coupling 20 reaches the proximity or limit switch 25 , the directional valve switches to direct the flow to lift the cylinder 14 . The choking action that takes place in the proportioning valve 31 has the effect of gradually slowing the speed of the cylinder rod 17 and its connected sucker rod 21 . The use of Parker No. FMDDDSM Manapac manual sandwich valve located between directional valve and the solenoid controls dampens the transition of the directional valve from the upstroke or downstroke to allow bumpless transfer of fluid to the cylinder 14 and balances pressures. This choking of flow by the proportioning valve 31 also slows action of cylinder rod 17 , preventing undue stress from being transmitted to the sucker rod 21 as the bottom of the downstroke of cylinder rod 17 is approached, then reached.
[0030] Directional valve 28 can be a Parker® valve model number D61VW001B4NKCG. Proportioning valve 31 can be a Parker® valve model number DFZ01C600012.
[0031] In one embodiment, the cylinder rod 17 and pumping string 21 are allowed to fall without any slowing. This free fall of rod 17 and string 21 from the elevated position to the rod 17 lowest position. Such free fall creates a jar or shock that dislodges any trash or unwanted debris from the string 21 . The operator turns the clean cycle on via the HMI. After the clean cycle is turned on, the next stroke down will perform the clean function event. The event starts by pumping the cylinder to the top of the stroke. For the current embodiment, it goes to the top switch. After reaching the top switch the down stroke for the clean out cycle begins. The bypass valve opens and the direction valve closes (resulting in the pump de-stroking to bypass pressure). The proportional valve ramps open to 75%, and the cylinder is drained resulting in the down stroke. The middle switch is ignored (this is unique for this function). When the bottom switch is detected the proportional valve is shut closed (not ramped; also unique). This has the benefit of creating a gentler “abrupt” stop by closing the proportional valve very quickly (not ramping it closed). This triggers the end of the clean out cycle. The function is turned off and the normal cycle resumes. Alternatively, the step requiring an operator to turn the cleaning cycle on may be eliminated, and this cleaning or cleanout cycle may be scheduled to automatically occur at a selected interval.
[0032] In one embodiment, an improved direct mount smart cylinder that does not use proximity switches may be used with an oil well pump, including sucker rod pumping. As a result, this embodiment does not require the use of a pedestal, though one may still be used if warranted. A linear displacement transducer may be installed inside the direct mount smart cylinder in order to measure the linear displacement of the rod of the oil well pump. The direct mount smart cylinder is able to determine the position of the rod without the use of proximity switches. A hall effects linear displacement transducer may be used.
[0033] The direct mount smart cylinder embodiment offers several benefits. It minimizes the possible points of oil leaks because a stuffing box is no longer needed. The height of the oil well pump may be reduced by half when a direct mount smart cylinder is implemented. The connection to the well is improved because no guy wires are used with the direct mount smart cylinder. The direct mount smart cylinder provides the position through the stroke instead of only at the location of the proximity switches. Because only one cable runs to the linear displacement sensor instead of multiple proximity sensors, the assembly of the oil well pump is easier and is safer because there are fewer loose electronics. The stroke length may be changed through the control system human machine interface without having to move proximity sensors. There are fewer or no moving parts in sight on the wellhead. The linear displacement transducer is a no wear item. The direct mount smart cylinder embodiment also increases the ability to change the speed on the fly.
[0034] Other and further embodiments utilizing one or more aspects of the inventions described above can be devised without departing from the spirit of Applicant's invention. Discussion of singular elements can include plural elements and vice-versa.
[0035] The order of steps can occur in a variety of sequences unless otherwise specifically limited. The various steps described herein can be combined with other steps, interlineated with the stated steps, and split into multiple steps. Similarly, elements have been described functionally and can be embodied as separate components or can be combined into components having multiple functions.
[0036] The inventions have been described in the context of preferred and other embodiments and not every embodiment of the invention has been described. Obvious modifications and alterations to the described embodiments are available to those of ordinary skill in the art. The disclosed and undisclosed embodiments are not intended to limit or restrict the scope or applicability of the invention conceived of by the Applicants, but rather, in conformity with the patent laws, Applicants intend to fully protect all such modifications and improvements that come within the scope or range of equivalent of the following claims.
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A hydraulic oil well pumping arrangement employs a compensating type hydraulic pump, a directional valving arrangement and a proportioning valving arrangement. When the directional valve is energized, oil is directed to the rod end of the hydraulic cylinder. In one embodiment, a time delay halts the movement of the sucker rod or pumping string to allow accumulation of oil in a slow following well. In another embodiment, the pumping string rapidly falls to the bottom of the stroke in order to shake or jar debris from the string.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to an FM receiver for receiving FSK binary signals and more particularly to a signal processing circuit such as a data limiter with a capacitively coupled voltage clamped input for exhibiting fast response time in the presence of input disturbances.
2. Background of the Invention
A block diagram of a prior art FM receiver system suitable for use in a synchronous paging system is illustrated in FIG. 1. The receiver comprises the antenna 10 which receives an RF signal and transmits it to a receiver 12 where the RF signal is amplified and converted into a first intermediate frequency (IF) signal by an RF amplifier and first mixer, respectively. This IF signal is preferrably directed to the receiver's back end where the first IF signal is converted to a second IF signal (in a dual conversion receiver) amplified, limited, filtered and demodulated. The voltage level of the output signal at output 14 represents the coded binary data. Output 14 may of course be viewed as having a Thevenin equivalent of a voltage source in series with an output resistance which is not shown. The output 14 of the receiver 12 is capacitively coupled to the input 15 of a data limiter 16 via a coupling capacitor 18. Internal or external limiter bias resistors (not shown) are normally used to bias the data limiter 16. The output of the data limiter 16 is directed to a data processor 20 for further desired processing.
The FM receiver system also includes one or more switches 22 (normally transistors) connected between the various components of the FM receiver system and the power supply. This switch is periodically turned ON and OFF by battery saver circuit 24 to provide a battery saving feature, which is a technique well known to those skilled in the art. A switch 26 (also, normally a transistor) is periodically closed to precharge the coupling capacitor 18, preferrably by placing a resistor 27 in parallel with the limiter bias resistors and input impedance thereby reducing the overall RC time constant. Switch 26 is normally closed simultaneously with the switch 22 but normally remains closed for a shorter time than switch 22 to provide this precharging feature.
Normally, in situations where it is necessary to pass digital data from the receiver 12 to the data limiter 16, capacitor 18 will be a relatively large value in order to pass the low frequency information in digital signals. Thus, a long time may be required to charge the capacitor 18, especially when it is connected to a high impedance such as the limiter bias resistors for the data limiter 16. A long charge time necessitates that receiver "ON" time be increased correspondingly to ensure that capacitor 18 is charged to its correct bias point and that valid data is delivered to the data processor 20 during the data decoding interval. The battery saver feature is clearly degraded by the extended receiver "ON" time since this consumes more battery energy than is desirable. The switch 26 is used to alleviate this situation by providing a momentary low impedance charge path in parallel with the data limiter's bias resistors immediately upon receipt of power from the battery saver 24, that is, when the switch 22 is closed. This allows capacitor 18 to more rapidly charge to a voltage dependent upon the average value of the incoming data. If the incoming data can be depended upon to have no long strings of ones or zeros the charging of capacitor 18 will closely approximate the desired bias voltage. Data decoding of the received bit stream can begin more rapidly and continue until the battery voltage B+ is again removed by switch 22, thereby enhancing the battery saver feature.
However, one problem still exists even when the coupling capacitor 18 is precharged. Under ideal conditions (an alternating one-zero data pattern) the average voltage level at the output of the receiver 12 will be at the desired carrier reference voltage, that is the voltage level which corresponds to an undeviated RF carrier signal. During the precharge interval, capacitor 18 will charge to a bias voltage which is consistent with this carrier reference voltage and proper data decoding will occur. If a long string of ones or zeros is received immediately before the opening of switch 26 the average DC voltage at the receiver output 14 will be offset from the desired reference. The average DC voltage is increased if a large number of ones are received or decreased if a large number of zeros are received.
Thus, relatively substantial DC voltage offsets from the correct bias voltage across capacitor 18 may still occur if this technique is used in an asynchronous system with unpredictable data patterns. This may result in erroneous outputs from the data limiter 16, long response time (the delay required between receipt of a signal and occurrence of valid data at the limiter output), and may ultimately result in the end user receiving no message or an erroneous message which differs from the originally transmitted message.
SUMMARY OF THE INVENTION
It is an object of the present invention to provide an improved signal processing circuit such as a data limiter with voltage clamped input.
It is another object of the present invention to provide a data limiter with enhanced response time.
It is another object of the present invention to provide a data limiter with enhanced response time which is suitable for use in either battery saver or non-battery saver receivers.
It is a further object of the present invention to provide a data limiter with voltage clamped input for fast response time suitable for use in battery saver receiver systems.
These and other objects of the present invention will become apparent to those skilled in the art upon consideration of the following description of the invention.
According to one embodiment of the present invention, a signal processing arrangement for reducing data errors due to excess bias offset and with enhancing response time when input signals are capacitively coupled to its input includes a first voltage comparing circuit for comparing the input signal with the reference voltage and providing a first output signal when the input signal exceeds the reference voltage by a first predetermined voltage. A first voltage clamp circuit is coupled to the input and prevents the voltage at the input from exceeding the reference voltage by more than the first predetermined voltage. A second voltage comparing circuit compares the input signal with the reference voltage and provides a second output signal when the input signal decreases below the reference voltage by a second predetermined voltage. A second voltage clamping circuit prevents the voltage at the input from decreasing below the reference voltage by more than the second predetermined voltage. Preferrably, the first and second voltage comparing circuits are selectively actuable by a battery saver control circuit.
The features of the invention believed to be novel are set forth with particularity in the appended claims. The invention itself, however both as to organization and method of operation, together with further objects and advantages thereof, may be best understood by reference to the following description taken in conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 shows a battery saver receiver system utilizing a precharging technique to enhance response time.
FIG. 2 shows a battery saver implementation of the present invention.
FIG. 3 shows an embodiment of the present invention implemented in a non-battery saver system.
FIG. 4 is a more detailed schematic of the present invention.
FIG. 5 shows a more detailed schematic of transconductance amplifier 134 utilized in FIG. 4.
FIG. 6 shows a more detailed schematic of transconductance amplifier 136 of FIG. 4.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Turning now to FIG. 2, a battery saver implementation of the present invention is shown. Once again antenna 10 provides receiver 12 with an input signal which is ultimately converted to a demodulated signal at receiver output 14 and delivered to capacitor 18. In the present embodiment, an F.M. receiver for receiving FSK binary data is preferred, but this is not to be limiting. A voltage clamp circuit 100 is coupled at its terminal 101 to the other terminal of capacitor 18 and also to an input 115 of data limiter 116. Terminal 105 of voltage clamp circuit 100 is coupled to input terminal 117 of limiter 116, which is also coupled to the limiter's bias source labeled V BIAS to establish the limiter's threshold voltage. A control input 123 of clamp circuit 100 is coupled to a battery saver circuit 124. Battery saver circuit 124 also serves as a control circuit which controls switch 22 to effect normal battery saver operation. The output of limiter 116 drives data processor 20. While the present invention is preferrably practiced in conjunction with a data limiter, it will be clear that the voltage clamp arrangement may be useful for other types of signal processing arrangements.
In operation, voltage clamp circuit 100 examines the input voltage of the limiter at terminal 115 and compares that to the reference voltage at terminal 117 which is the limiter threshold voltage. It then determines what effect the incoming data, which is charging and discharging capacitor 18, and what effect the switching of switch 22 during battery saver operation, is having upon the voltage at the input 115 of limiter 116. If it is determined that the input voltage has reached a predetermined maximum acceptable upward deviation from the limiter threshold voltage, voltage clamp circuit 100 clamps the input voltage at terminal 115 at this predetermined maximum level.
If on the other hand, it is determined that the input voltage has reached a predetermined maximum acceptable downward deviation from the limiter threshold level, voltage clamp circuit 100 clamps the voltage at node 115 at this predetermined lower limit. In this manner, capacitor 18, is maintained at an appropriate charge to properly deliver data to limiter 116 for processing. This prevents slow response time and excessive data errors. Of course, it is clear that at least one of the upward and downward deviations must be greater than zero volts.
For the battery saver systems of FIG. 2, it may be desirable to only actuate the voltage clamp circuit by providing an appropriate signal at control input 123, for the first few moments of the battery saver cycle, thereby forcing a rapid charge of capacitor 18. Or, it may be preferrable to have voltage clamp circuit 100 actuated for the entire battery saver cycle, i.e. voltage clamp circuit 100 would be actuated whenever switch 22 is closed.
The RC time constant associated with capacitor 18 when voltage clamp circuit 100 is not actuated is clearly determined primarily by the Thevenin resistance at the output of receiver 12 in series with the input resistance of limiter 116. This time constant should preferrably be chosen to allow the lowest conceivable frequencies of data information to pass. When the clamp circuit is actuated and when the voltage at the input 115 of limiter 116 reaches either limiter voltage, the input impedance of the limiter is shunted thereby significantly reducing the time constant. One data bit period has been found suitable for the shorter time constant.
One advantage of the present arrangement is that it can be utilized in non-battery saver receiver systems. Such an implementation is shown in FIG. 3 wherein receiver 12 is continously actuated as is voltage clamp circuit 100. While in the preferred embodiment, voltage clamp circuit 100 would be actuated by a high signal level at control input 123 such as B+, those skilled in the art will readily recognize that other embodiments may be equally functional.
Turning now to FIG. 4, a more detailed representation of the present invention is shown. According to this embodiment, bias voltage V+ is supplied to limiter 116 through a pair of bias resistors 130 and 132 to establish the limiter threshold, but this is not to be limiting. A first transconductance amplifier 134 serves as a comparing circuit and has its positive input coupled to terminal 115 and its negative input coupled to terminal 117. A second transconductance amplifier 136 serves as a comparing circuit and is similarly connected. Transconductance amplifiers 134 and 136 are preferrably selectively actuable by applying a high logic level at terminals 138 and 140 respectively. The junction of terminals 138 and 140 forms control input 123 to be driven by battery saver circuit 124.
Transconductance amplifers 134 and 136 serve to compare the input voltage at terminal 115 with the reference voltage at terminal 117 and are preferrably somewhat specialized for the present application. In order to begin a change in state at the output of amplifier 134, its inverting input must see a voltage level which is greater than the non-inverting input by a predetermined voltage. This predetermined voltage is the difference between the reference voltage level at the limiter input and the minimum permissible input voltage. Similarly, transconductance amplifier 136 begins changing output states when the non-inverting terminal is a predetermined voltage greater than the inverting terminal, wherein this predetermined voltage is the permissible differential between the reference voltage and the maximum acceptable input voltage. One embodiment for implementing such transconductance amplifiers will be discussed later.
The output 141 of transconductance amplifer 134 drives the base of a PNP transistor 142 which serves as a voltage clamp. The collector of transistor 142 is coupled to node 115 and the emitter of transistor 142 is coupled to a DC source B+ having a voltage level greater than a saturation voltage above the lower limit of the permissible input voltage at node 115. Similarly, an NPN transistor 144 serves as a voltage clamp and has its base driven by the output 143 of transconductance amplifier 136 and its collector coupled to node 115. The emitter of NPN transistor 144 is coupled to a DC voltage source V- having a voltage level which is less than one saturation voltage lower than the upper permissible input voltage at node 115. In the preferred embodiment transistors 142 and 144 are in a common emitter configuration, however, a common collector configuration may be successfully utilized for either or both, provided amplifiers 134 and 136 are reconfigured accordingly. Thus, when the input voltage at node 115 approaches the upper limit of permissible input voltage, transconductance amplifier 136 causes transistor 144 to begin to turn on, clamping the voltage at node 115 at its upper limit. Conversely, if the input voltage at node 115 drops to near the lower limit of permissible input voltages, transconductance amplifier 134 begins to turn on transistor 142 clamping the voltage at node 115 to its lower limit. In this manner, the voltage at node 115 is always within the upper and lower limit of permissible voltage.
In the preferred embodiment, the present invention is practiced in conjunction with a miniature paging receiver. Such paging receiver, typically operates on a single low voltage battery cell having an output voltage of approximately 1.3 volts. As such, B+ is preferrably approximately 1.3 volts. Accordingly, V+ may be approximately 1 volt and V- may be approximately 0.35 volts. The preferred input voltage at node 115 is centered around approximately 1.0 volts and the FM detector provides an output of approximately 100 millivolts peak to peak. In such a system it is desirable for the output of the FM detector to be reasonably consistent. In the preferred embodiment, it is desirable to maintain the voltage at node 115 within approximately 50 millivolts of its optimum input voltage so that the total acceptable range is about the same as the peak-to-peak output of the FM detector. As such, transconductance amplifiers 134 and 136 should experience a change in output when the voltage at node 115 attempts to deviate by more than approximately 50 millivolts from this optimum voltage. The circuits of FIGS. 5 and 6 show transconductance amplifiers which have approximately 54 millivolts of offset before an output transition takes place.
It should be noted that the input signals at terminal 115 will not likely appear as perfectly square, logic-like signals since the limiter's purpose is to transform them into appropriate logic signals. This is, of course, accomplished in the limiter by comparing the input with the reference voltage and making a logic decision based upon that comparison. If the amplitude of the input signal is substantially less peak-to-peak than the difference between the upper permissible input voltage and the lower permissible input voltage, and if a capacitor voltage offset error is created (by battery saver or other signal disturbance) then the non-ideal wave shape of the input signal, coupled with the offset error, will create a situation wherein substantial deviation from an ideal 50% duty cycle (in an alternating one-zero pattern) is likely. It is, therefore, desirable for the peak-to-peak amplitude of the input signal to be equal to or slightly less than the difference between the upper and lower permissible input levels. This causes clamp circuit 100 to operate only when a disturbance necessitates it and allows conventional operation otherwise. This, however, is not to be limiting since the circuit will also function with larger input signals.
Turning now to FIG. 5, a preferred configuration of transconductance amplifier 134 is shown to include NPN transistors 150 and 152 having their emitters coupled together to form a differential amplifier configuration. The junction of their emitters is coupled through a current source 154 to ground. The base of transistor 150 forms the inverting input of amplifier 134 while the base of transistor 152 forms the non-inverting input of amplifier 134. The ratio of the area of the emitters of transistors 152 and 150 are scaled at a ratio of 8 to 1 as shown with the emitter of transistor 152 having 8 times the area of transistor 150 in order to achieve the desired 54 millivolts of offset voltage. By adjusting this ratio, the offset voltage may be changed to match the peak output of the FM detector. As it is well known in the art, every time the ratio is doubled an additional 18 millivolts of offset is attained.
A PNP transistor 156 having two collectors has a first of the collectors coupled back to its base and coupled to the collector of transistor 152. The second collector is coupled to the collector of transistor 150 and this junction forms the amplifiers' output 141. The emitter of transistor 156 is coupled to B+. The connection of transistor 156 forms a current mirror supplying current to transistor 150. Diode 158 is coupled between node 141 and V- with its anode connected to node 141 in order to prevent amplifier 134 from saturating.
Transistors 150, 152, 156, and current source 154 form the heart of amplifier 134. An NPN transistor 160 has its collector coupled through a resistor 162 to the base of transistor 156. The emitter of transistor 160 is grounded. The base of transistor 160 is normally pulled toward B+ by resistor 164. An NPN transistor 166 has its emitter coupled to ground and its collector coupled to the base of transistor 160. The base of transistor 166 is coupled to ground through a resistor 170 and to node 138 through a resistor 168. Transistors 160 and 166 along with their associated resistors are utilized to effect turn-off of amplifier 134. When the amplifier is turned ON a logic high level is applied to node 138. This turns transistor 166 ON cutting off transistor 160 which allows the base of transistor 156 to be driven by the collector of transistor 152.
When a low logic level is applied to input 138, transistor 166 is turned OFF allowing transistor 160 to be turned ON. By appropriately choosing resistor 162 to draw more current than current source 154 supplies, transistor 160 is able to effectively disable amplifier 134 by forcing the current from the second collector of transistor 156 to always exceed the current from the collector of transistor 150 regardless of the input voltage conditions. This forces the output of amplifier 134 to the high state when the amplifier is turned OFF. In the preferred embodiment, current source 154 sources approximately 10 microamps of current but this is not to be limiting.
Turning now to FIG. 6, a detailed schematic of a preferred transconductance amplifer suitable for use as amplifier 136 is shown. Amplifier 136 includes a pair of transistors 180 and 182, both NPN, which have their emitters connected to form a differential amplifer. The emitters are coupled through current source 184 to ground. In this amplifer the emitter areas of transistors 180 to 182 are at a ratio of 8 to 1 (that is, the emitter of transistor 180 is larger). The base of transistor 180 forms the inverting input of the amplifier, while the base of transistor 182 forms the non-inverting input of the amplifier. A PNP transistor 186 has two collectors, one of which is coupled back to its base and in turn coupled to the collector of transistor 182. The second collector is coupled to the collector of transistor 180 and forms output node 143. The emitter of transistor 186 is coupled to B+. A diode 188 is coupled between B+ and output node 141 with its anode towards B+ in order to prevent output saturation. These components form the heart of transconductance amplifier 136.
A PNP transistor 190 has its emitter coupled to B+ and its collector to the base of transistor 186. The base of transistor 190 is coupled through a resistor 192 to B+. The base of transistor 190 is driven through resistor 194 by the collector of transistor 196. The emitter of transistor 196 is coupled to ground and the base of transistor 196 is normally pulled high through a resistor 198. The base of transistor 196 is driven by the collector of a transistor 200. The emitter of transistor 200 is connected to ground and the base is normally pulled low to ground through a resistor 202. The base is driven by node 140 through a resistor 204.
In normal operation, a logic high is applied to node 140 in order to enable amplifier 136. This turns on transistor 200 which in turn turns off transistor 196 thereby turning off transistor 190. When a logic low appears at node 140 transistor 200 is turned off which allows transistor 196 to be turned on which turns on transistor 190 shorting the base of transistor 186 to B+. Resistors 192 and 194 should be selected so that transistor 190 can source more current than current source 184 can sink (preferrably about 10 μA). This effectively disables amplifier 136 by forcing its output to a low state. It is clear that many other possible configurations are suitable for amplifier 134 and 136.
Thus it is apparent that in accordance with the present invention, an apparatus that fully satisfies the objectives, aims and advantages is set forth above. While the invention has been described in conjunction with specific embodiments, it is evident that many alternatives, modifications and variations will become apparent to those skilled in the art in light of the foregoing description. Accordingly, it is intended that the present invention embrace all such alternatives, modifications and variations as fall within the spirit and broad scope of the appended claims.
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A signal processing circuit with enhanced response time includes a data limiter circuit having an input and an input capacitor having one terminal coupled to the input. A first selectively actuable voltage clamping circuit responds to a first comparing circuit and is coupled to the input for preventing the voltage at the input from exceeding a predetermined upper voltage. A second selectively actuable voltage clamping circuit is responsive to a second comparing circuit and is coupled to the input for preventing the voltage at the input from decreasing below a predetermined lower voltage.
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TECHNICAL FIELD
The present invention relates generally to semiconductor devices and, in particular, to a clock synchronization circuit and a semiconductor device having the same.
BACKGROUND DESCRIPTION
The operating speed of a central processing unit (CPU), which is a signal processing unit, has been radically improved over the last several years. However, the operating speed of dynamic random access memory (DRAM) semiconductor devices, which correspond to the main memory of a CPU, has not been greatly improved. Rather, it has been identified as a main bottle-neck factor of computer systems. To reduce the difference in operating speed between a CPU and a DRAM semiconductor device, new DRAM semiconductor devices are being developed such as synchronous DRAM (SDRAM) semiconductor devices, Rambus DRAM semiconductor devices, synclink DRAM semiconductor devices, and so forth. These DRAM semiconductor devices have a feature such that data received from an external source or output to the outside is processed in synchronization with an internal clock. The internal clock is generated from an external clock signal which is received from an external source. A circuit which synchronizes the internal clock signal with the external clock signal is referred to as a clock synchronization circuit. A phase locked loop and a delay locked loop are included in the clock synchronization circuit. Among them, the delay locked loop is usually used in the DRAM semiconductor devices.
FIG. 1 is a block diagram of a clock synchronization circuit 101 according to the prior art. Referring to FIG. 1, the clock synchronization circuit 101 has a dual loop structure having a core delay locked loop 111 and a peripheral delay locked loop 113 . The core delay locked loop 111 receives an external clock signal inCLK and generates 6 sub clock signals CK 1 through CK 6 (hereinafter collectively referred to as “CK 1 -CK 6 ”). The sub clock signals CK 1 -CK 6 have a predetermined phase difference. The peripheral delay locked loop 113 receives the sub clock signals CK 1 -CK 6 , generates a clock signal Q, and synchronizes the clock signal Q with an external clock signal inCLK using a phase interpolation technique. The peripheral delay locked loop 113 includes a phase selector 121 , a selection phase transformer 131 , a phase interpolator 141 , a phase detector 151 and a controller 161 . The phase interpolator 141 interpolates the phases of signals Φ′ and Ψ′ output from the selective phase transformer 131 to generate the clock signal Q. The phase interpolator 141 receives 16 bits of signals output from the controller 161 in order to determine the degree of interpolation of the phase of the clock signal Q.
The phase interpolation technique used by the conventional clock synchronization circuit 101 can achieve its effects when the slew rate of an external clock signal inCLK is small, or when a smaller phase boundary can be provided by increasing the number of sub-clock signals CK 1 -CK 6 generated by the core delay locked loop 111 . However, in the former case, the dynamic noise sensitivity of the clock synchronization circuit 101 is increased, so that jitter performance is degraded. In the latter case, a burden on the clock synchronization circuit 101 is increased.
Accordingly, it would be desirable and highly advantageous to have a clock synchronization circuit having improved jitter performance.
SUMMARY OF THE INVENTION
The problems stated above, as well as other related problems of the prior art, are solved by the present invention, a clock synchronization circuit and a semiconductor device having the same. Both the clock synchronization circuit and semiconductor device have improved jitter performance with respect to prior art devices.
According to a first aspect of the invention, there is provided a clock synchronization circuit for synchronizing an external clock signal with an internal clock signal. The circuit is connected to a clock buffer adapted to output the internal clock signal. The circuit includes: a first loop adapted to receive the external clock signal and output a plurality of reference clock signals having a predetermined phase difference therebetween; and a second loop adapted to delay the plurality of reference clock signals, select a signal from among the plurality of delayed reference clock signals, provide the selected signal to the clock buffer, detect a phase difference between the internal clock signal output from the clock buffer and the external clock signal, generate a plurality of control voltages to reduce the detected phase difference, and control a delay amount of each of the plurality of reference clock signals in response to the plurality of control voltages, so as to synchronize the internal clock signal with the external clock signal.
According to a second aspect of the invention, there is provided a clock synchronization circuit for synchronizing an external clock signal with an internal clock signal. The circuit is connected to a clock buffer. The circuit includes: a first loop adapted to receive the external clock signal and output first through fourth reference clock signals, consecutive pairs of the first through fourth reference clock signals having a 90° phase difference therebetween; and a second loop having first through fourth voltage control delay units adapted to delay the first through fourth reference clock signals, the second loop adapted to select a reference clock signal from among the first through fourth delayed reference clock signals, provide the selected reference clock signal to the clock buffer for conversion to the internal clock signal, detect a phase difference between the internal clock signal output from the clock buffer and the external clock signal, generate a plurality of control voltages having different levels according to the detected phase difference to reduce the detected phase difference, provide the plurality of control voltages to the first through fourth voltage control delay units, and control the delay amount of the selected reference clock signal in response to a control voltage from among the plurality of control voltages, so as to synchronize the internal clock signal with the external clock signal.
According to a third aspect of the invention, a level of the control voltage applied to a voltage control delay unit among the first through fourth voltage control delay units that outputs the selected reference clock signal is different from levels of other control voltages from among the plurality of control voltages applied to other voltage control delay units among the first through fourth voltage control delay units that generate unselected reference clock signals.
According to a fourth aspect of the invention, delay amounts applied to the first through fourth reference clock signals are always detected, the selected reference clock signal is switched to an unselected one of the first through fourth delayed reference clock signals having a phase that lags a phase of the selected reference clock signal by 90° when the delay amount of the selected reference clock signal approaches a maximum value, and the selected reference clock signal is switched to an unselected one of the first through fourth delayed reference clock signals having a phase that leads the phase of the selected reference clock signal by 90° when the delay amount of the selected reference clock signal approaches a minimum value.
According to a fifth aspect of the invention, there is provided a clock synchronization circuit for synchronizing an external clock signal with an internal clock signal. The circuit is connected to a clock buffer. The circuit includes: a first loop adapted to receive the external clock signal and output a first and a second reference clock signal, the reference clock signals being differential signals having a 90° phase difference therebetween; and a second loop having a first voltage control delay unit adapted to delay the first reference clock signal to output a first and a second differential clock signal, and a second voltage control delay unit adapted to delay the second reference clock signal to output a third and a fourth differential clock signal, wherein each of the first and second voltage control delay units is controlled by one of a reference voltage and a control voltage, the second loop adapted to select a differential clock signal among the first through fourth differential clock signals output from the first and second voltage control delay units, provide the selected differential clock signal to the clock buffer, detect a phase difference between the internal clock signal output from the clock buffer and the external clock signal, and provide the control voltage to one of the first and the second voltage control delay units according to the detected phase difference to reduce the detected phase difference, so that a delay amount of the selected differential clock signal is controlled, so as to synchronize the internal clock signal with the external clock signal.
According to a sixth aspect of the invention, a level of the reference voltage is different from a level of the control voltage.
According to a seventh aspect of the invention, delay amounts of the first through fourth differential clock signals are always detected, the selected differential clock signal is switched to an unselected one of the first through fourth differential clock signals having a phase that lags the phase of the selected clock signal by 90° when the delay amount of the selected differential clock signal approaches a maximum value, and the selected differential clock signal is switched to an unselected one of the first through fourth differential clock signals having a phase that leads the phase of the selected clock signal by 90° when the delay amount of the selected differential clock signal approaches a minimum value.
According to an eighth aspect of the invention, there is provided a semiconductor device including: a clock buffer adapted to output an internal clock signal suitable for internal use by the semiconductor device; a first loop adapted to receive the external clock signal and output a plurality of reference clock signals having a predetermined phase difference therebetween; and a second loop adapted to delay the plurality of reference clock signals, select a signal from among the plurality of delayed reference clock signals, provide the selected signal to the clock buffer for conversion to the internal clock signal, detect a phase difference between the internal clock signal output from the clock buffer and the external clock signal, generate a plurality of control voltages to reduce the detected phase difference, and control a delay amount of each of the plurality of reference clock signals in response to the plurality of control voltages, so as to synchronize the internal clock signal with the external clock signal.
According to a ninth aspect of the invention, the semiconductor device is a synchronous dynamic random access memory (SDRAM) semiconductor device.
According to a tenth aspect of the invention, there is provided a semiconductor device including: a clock buffer adapted to output an internal clock signal suitable for internal use by the semiconductor device; a first loop adapted to receive an external clock signal and output first through fourth reference clock signals having a 90° phase difference therebetween; and a second loop having first through fourth voltage control delay units adapted to delay the first through fourth reference clock signals, the second loop adapted to select a reference clock signal among the first through fourth reference clock signals output from the first through fourth voltage control delay units and provide the selected reference clock signal to the clock buffer for conversion to the internal clock signal, detect a phase difference between the internal clock signal output from the clock buffer and the external clock signal, generate a plurality of control voltages having different levels according to the detected phase difference to reduce the detected phase difference, provide the plurality of control voltages to the first through fourth voltage control delay units, and control delay amounts of the first through fourth reference clock signals in response to the plurality of control voltages, so as to synchronize the internal clock signal with the external clock signal.
According to an eleventh aspect of the invention, there is provided a semiconductor device including: a clock buffer adapted to output an internal clock signal suitable for internal use by the semiconductor device; a first loop adapted to receive an external clock signal and output first and second reference clock signals of differential types having a 90° phase difference therebetween; and a second loop having a first voltage control delay unit adapted to delay the first reference clock signal to output a first and a second differential clock signal, and a second voltage control delay unit adapted to delay the second reference clock signal to output a third and a fourth differential clock signal, wherein each of the first and second voltage control delay units is controlled by one of a reference voltage and a control voltage, the second loop adapted to select a signal among the first through fourth differential clock signals output from the first and second voltage control delay units, provide the selected signal to the clock buffer for conversion to the internal clock signal, detect a phase difference between the internal clock signal output from the clock buffer and the external clock signal, and provide the control voltage to one of the first and the second voltage control delay units according to the detected phase difference to reduce the detected phase difference, so that a delay amount of the selected signal is controlled, so as to synchronize the internal clock signal with the external clock signal.
These and other aspects, features and advantages of the present invention will become apparent from the following detailed description of preferred embodiments, which is to be read in connection with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a block diagram of a clock synchronization circuit according to the prior art;
FIG. 2 is a block diagram illustrating a clock synchronization circuit according to an illustrative embodiment of the invention together with a clock buffer;
FIG. 3 is a timing diagram illustrating clock switching of the second loop of FIG. 2 according to an illustrative embodiment of the invention;
FIG. 4, which is a block diagram illustrating the second loop of FIG. 2 in further detail according to an illustrative embodiment of the invention;
FIG. 5 is a block diagram illustrating the operations of the first and second charge pumps of FIG. 4 according to an illustrative embodiment of the invention;
FIGS. 6A and 6B, which are phase diagram illustrating the delay control methods performed by the first through fourth voltage control delay units of FIG. 2 according to an illustrative embodiment of the invention;
FIG. 7 is a block diagram illustrating the window finder of FIG. 4 in further detail according to an illustrative embodiment of the invention;
FIG. 8 is a block diagram of a clock synchronization circuit according to the second illustrative embodiment of the invention together with a clock buffer;
FIG. 9 is a block diagram illustrating the second loop of FIG. 8 in further detail according to an illustrative embodiment of the invention; and
FIG. 10 is a phase diagram illustrating a delay control method performed by the second loop of FIG. 8 according to an illustrative embodiment of the invention.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
It is to be understood that the present invention may be implemented in various forms of hardware, software, firmware, special purpose processors, or a combination thereof. Preferably, the present invention is implemented as a combination of both hardware and software, the software being an application program tangibly embodied on a program storage device. The application program may be uploaded to, and executed by, a machine comprising any suitable architecture. Preferably, the machine is implemented on a computer platform having hardware such as one or more central processing units (CPU), a random access memory (RAM), and input/output (I/O) interface(s). The computer platform also includes an operating system and microinstruction code. The various processes and functions described herein may either be part of the microinstruction code or part of the application program (or a combination thereof) which is executed via the operating system. In addition, various other peripheral devices may be connected to the computer platform such as an additional data storage device.
It is to be further understood that, because some of the constituent system components depicted in the accompanying Figures may be implemented in software, the actual connections between the system components may differ depending upon the manner in which the present invention is programmed. Given the teachings herein, one of ordinary skill in the related art will be able to contemplate these and similar implementations or configurations of the present invention.
A general description of the present invention will now be provided to introduce the reader to the concepts of the invention. Subsequently, more detailed descriptions of various aspects of the invention will be provided with respect to FIGS. 2 through 10.
Hereinafter, embodiments of the present invention will be described in detail with reference to the attached drawings. However, the embodiments of the present invention can be modified into various other forms, and the scope of the present invention must not be interpreted as being restricted to the embodiments. The embodiments are provided to more completely explain the scope of the present invention to those skilled in the art. In the entire specification, like reference numerals denote the same members. Furthermore, each embodiment disclosed and described in this specification includes a conductive-type embodiment that is complementary to each embodiment.
FIG. 2 is a block diagram illustrating a clock synchronization circuit 201 according to an illustrative embodiment of the invention together with a clock buffer 221 . The clock synchronization circuit 201 includes first and second loops 211 and 213 . The first loop 211 receives an external clock signal inCLK and generates first through fourth reference clock signals RefCLK 1 through RefCLK 4 (hereinafter collectively referred to as “REFCLK 1 -REFCLK 4 ”). Each consecutive pair of the first through fourth reference clock signals RefCLK 1 -RefCLK 4 have a phase difference of 90 degrees. That is, the phase of the second reference clock signal RefCLK 2 lags the phase of the first clock signal RefCLK 1 by 90 degrees, the phase of the third reference clock signal RefCLK 3 lags the phase of the second reference clock signal RefCLK 2 by 90 degrees, and the phase of the fourth reference clock signal RefCLK 4 lags the phase of the third reference clock signal RefCLK 3 by 90 degrees. If the number of the clock reference clock signal RefCLK 1 through RefCLK 4 is increased, the phase difference between the reference clock signals RefCLK 1 through RefCLK 4 is reduced.
The second loop 213 receives the first through fourth reference clock signals RefCLK 1 through RefCLK 4 and outputs a clock signal iCLK. That is, the second loop 213 controls the delay amounts of the first through fourth reference clock signals RefCLK 1 through RefCLK 4 using an analog control voltage, and synchronizes an internal clock signal fCLK with an external clock signal inCLK. The second loop 213 selects one among the first through fourth clock signals CLK 1 -CLK 4 obtained by controlling the delay amounts of the first through fourth reference clock signals RefCLK 1 -RefCLK 4 , and provides the selected clock signal as a clock signal iCLK to the clock buffer 221 .
As shown in FIG. 3, which is a timing diagram illustrating clock switching of the second loop 213 of FIG. 2 according to an illustrative embodiment of the invention, when the delay amount of the selected clock signal iCLK increases and approaches a maximum value or when the delay amount thereof decreases and approaches a minimum value, the selected clock signal is switched to another clock signal. For example, if the delay amount of the first clock signal CLK 1 approaches the maximum value in a state where the first clock signal CLK 1 has been selected, the first clock signal CLK 1 is switched to the second clock signal CLK 2 , while the first, third and fourth clock signals CLK 1 , CLK 3 and CLK 4 return to the original phase relationship provided from the first loop 211 . If the delay amount of the first clock signal CLK 1 approaches the minimum value, the first clock signal CLK 1 is switched to the fourth clock signal CLK 4 . As described above, the selected clock signal iCLK is switched to another clock signal before it reaches the limit of the maximum value or minimum value of its delay amount, whereby the total phase region can be covered.
Referring back to FIG. 2, the second loop 213 includes first through fourth voltage control delay units 231 through 234 , a multiplexer 241 , a phase detector 251 and a controller 261 .
The first through fourth voltage control delay units 231 through 234 delay the first through fourth reference clock signals RefCLK 1 -RefCLK 4 , respectively, output from the first loop 211 . Each of the first through fourth voltage control delay units 231 through 234 consists of four delay elements, as shown in FIG. 4, which is a block diagram illustrating the second loop 213 of FIG. 2 in further detail according to an illustrative embodiment of the invention. Among the first through fourth voltage control delay units 231 through 234 , a voltage control delay unit for outputting a selected clock signal iCLK is controlled by a control voltage which is different from control voltages by which voltage control delay units for outputting non-selected clock signals are controlled. For example, if the first clock signal CLK 1 is selected, a control voltage VC 1 supplied from the controller 261 to the first voltage control delay unit 231 is different from control voltages VC 2 supplied to the second through fourth voltage control delay units 232 through 234 . The control voltages VC 2 , which are supplied to the second through fourth voltage control delays 232 through 234 for outputting non-selected clock signals, are the same.
In the first through fourth voltage control delay units 231 through 234 , the delay time for each of the first through fourth clock signals CLK 1 -CLK 4 varies with the number of delay elements included in each of the delay units. That is, when a large number of delay elements are provided, the delay time for each of the first through fourth clock signals CLK 1 through CLK 4 becomes long (i.e., increasing the number of delay units increases the delay time). On the other hand, when a small number of delay elements are provided, the delay time for each of the first through fourth clock signals CLK 1 through CLK 4 becomes short (i.e., decreasing the number of delay units decreases the delay time). Also, the delay amount of each of the first through fourth clock signals CLK 1 through CLK 4 varies with the sizes of the control voltages VC 1 and VC 2 applied to the first through fourth voltage control delay units.
A delay control method of the first through fourth voltage control delay units 231 through 234 will now be described with reference to FIGS. 6A and 6B, which are phase diagram illustrating the delay control methods performed by the first through fourth voltage control delay units 231 through 234 of FIG. 2 according to an illustrative embodiment of the invention. FIG. 6A refers to the case where the delay amount of the selected clock signal iCLK increases, and FIG. 6B refers to the case where the delay amount of the selected clock signal iCLK decreases. The selected clock signal iCLK is delayed within the delay control range of the first through fourth voltage control delay units 231 through 234 . The selected clock signal iCLK must be switched to another clock signal before its delay amount reaches the maximum or minimum value, and must be able to be continuously switched in any direction. Here, as a delay range to be covered by the first through fourth voltage control delays 231 through 234 becomes narrower, the number of delay elements included in each of the first through fourth voltage control delays 231 through 234 decreases. Thus, power consumption is reduced, and the jitter performance is improved.
When a condition occurs in which the delay variation speed of the selected clock signal iCLK is three times as fast as the delay variation speeds of three unselected clock signals, switching between the clock signals CLK 1 through CLK 4 can be continuously conducted in every direction. In FIG. 6A, the initial phases of the first through fourth clock signals CLK 1 through CLK 4 exist at 0 degree, 90 degrees, 180 degrees and 270 degrees, respectively, and the first clock signal CLK 1 at 0 degree is initially selected. When the first clock signal CLK 1 is rotated counterclockwise due to an increase in its delay amount, the second through fourth clock signals CLK 2 through CLK 4 rotate clockwise, during which the first and second clock signals CLK 1 and CLK 2 meet at +67.5 degrees. Then, the second clock signal CLK 2 is selected as the clock signal iCLK, and the first, third and fourth clock signals CLK 1 , CLK 3 and CLK 4 are moved from the original position to a position departing by 7.5 degrees. FIG. 6B shows the case where the first clock signal CLK 1 is switched to the second clock signal CLK 2 , and then the second clock signal CLK 2 is rotated clockwise due to a decrease in its delay amount. When the second clock signal CLK 2 is rotated clockwise, the first, third and fourth clock signals CLK 1 , CLK 3 and CLK 4 are rotated counterclockwise. During that time, when the first and second clock signals CLK 1 and CLK 2 meet each other, the first clock signal CLK 1 is re-selected as the clock signal iCLK, while the second through fourth clock signals CLK 2 through CLK 4 are moved from the original positions to positions departing by 7.5 degrees. In this method, a delay range to be covered by a voltage control delay unit is −67.5° to +67.5°.
The multiplexer 241 is connected to the first through fourth voltage control delay units 231 through 234 , and receives the first through fourth clock signals CLK 1 -CLK 4 and selects one among the first through fourth clock signals CLK 1 -CLK 4 in response to a control signal MC output from the controller 261 .
The clock buffer 221 converts the voltage level of the clock signal iCLK output from the multiplexer 241 and outputs the internal clock signal fCLK. The clock buffer 221 is widely used in semiconductor devices, in particular, in SDRAM semiconductor devices. In this case, the clock buffer 221 converts the voltage level of the received clock signal iCLK into a voltage level suitable to the inside of SDRAM semiconductor devices to generate the internal clock signal fCLK.
The phase detector 251 receives the internal clock signal fCLK and the external clock signal inCLK, compares the phases of the two signals to each other to generate phase information signals up and dn, and provides the phase information signals up and dn to the controller 261 . The phase detector 251 can be implemented by a typical phase detector.
The controller 261 receives the phase information signals up and dn, and outputs the control voltages VC 1 and VC 2 for controlling the delay amounts of the first through fourth voltage control delay units 231 through 234 on the basis of phase information included in the phase information signals up and dn. The controller 261 also receives the first through fourth clock signals CLK 1 -CLK 4 output from the first through fourth voltage control delay units 231 through 234 and detects a phase window wherein the first through fourth clock signals CLK 1 -CLK 4 exist, to determine which clock signal is to be selected by the multiplexer 241 .
A detailed block diagram of the controller 261 is shown in FIG. 4 which, as noted above, is a block diagram illustrating the second loop 213 of FIG. 2 in further detail according to an illustrative embodiment of the invention. Referring to FIG. 4, the controller 261 includes a window finder 411 , a state decoder 421 , and first and second charge pumps 431 and 432 .
The window finder 411 receives the first through fourth clock signals CLK 1 -CLK 4 and a selection code signal sel, and finds a phase window where the selected clock signal iCLK exists, thereby determining whether the current selected clock signal iCLK is to be switched. FIG. 7 is a block diagram illustrating the window finder 411 of FIG. 4 in further detail according to an illustrative embodiment of the invention. Referring to FIG. 7, the window finder 411 includes inverters 711 through 714 , NAND gates 721 through 724 , D flip-flops 731 through 734 , and multiplexers 741 and 742 . The inverters 711 through 714 and the NAND gates 721 through 724 receive the first through fourth clock signals CLK 1 -CLK 4 and make a window between the clock edges of each of the first through fourth clock signals CLK 1 -CLK 4 . The window is sampled by the rising edge of the selected clock signal iCLK, to find a phase window where the current selected clock signal iCLK exists. The window information is output as signals up_sel and dn_sel while passing through the multiplexers 741 and 742 which are controlled by a selection code signal. If the selection code signal is ‘00’ and the second clock signal CLK 2 must be selected since the first clock signal has been selected, the signal up_sel is output to increase the current selection code signal. The window finder 411 is an important block to determine jitter upon switching between clock signals. Therefore, the structure of the window finder 411 must be designed to be as symmetrical as possible, to reduce a path mismatch between the paths of the first through fourth clock signals CLK 1 through CLK 4 and the path of a selected clock signal iCLK.
Referring back to FIG. 4, the state decoder 421 receives the output signals up_sel and dn_sel of the window finder 411 , determines the next selection code from a current selection code, and provides a signal MC depending on the determined selection code to the multiplexer 241 . Also, the state decoder 421 provides the selection code signal sel to the window finder 411 .
The first and second charge pumps 431 and 432 receive the output signals up and dn of the phase detector 251 and generate differential control voltages VC 1 and VC 2 . Here, when the first charge pump 431 is provided with the output signal up of the phase detector 251 , then the second charge pump 432 is provided with the output signal dn of the phase detector 251 . When the first charge pump 431 is provided with the output signal dn of the phase detector 251 , then the second charge pump 432 is provided with the output signal up of the phase detector 251 .
FIG. 5 is a block diagram illustrating the operations of the first and second charge pumps 431 and 432 of FIG. 4 according to an illustrative embodiment of the invention. Referring to FIGS. 4 and 5, the first charge pump 431 provides the control voltage VC 1 to a voltage control delay unit for generating a selected clock signal iCLK, and the second charge pump 432 provides the control voltage VC 2 to voltage control delay units for generating non-selected clock signals. The first and second charge pumps 431 and 432 provide the same current. The capacitors 511 through 514 are connected to the first through fourth voltage control delay units 231 through 234 , respectively. When the capacities of the capacitors 511 through 514 are all the same, a selected clock signal iCLK is delayed at a speed that is three times as fast as the delay speeds of unselected clock signals. When the selected clock signal iCLK is switched to another clock signal, the first and second charge pumps 431 and 432 are switched to corresponding capacitors, so as to provide the control voltages VC 1 and VC 2 to corresponding voltage control delay units 231 through 234 , and charge re-distribution occurs in each capacitor, so that the delay control range of −67.5° to +67.5° shown in FIGS. 6A and 6B is established.
FIG. 8 is a block diagram of a clock synchronization circuit 801 according to the second illustrative embodiment of the invention together with a clock buffer 221 . The same reference numerals of FIG. 8 as those of FIG. 2 denote the same elements. Referring to FIG. 8, a clock synchronization circuit 801 includes first and second loops 811 and 813 . The first loop 811 generates first and second reference clock signals RefCLK 1 and RefCLK 2 having a phase difference of 90 degrees. The second loop 813 includes first and second voltage control delay units 831 and 832 , a multiplexer 241 , a phase detector 251 and a controller 861 . The clock synchronization circuit 801 can perform the same function as the function of the clock synchronization circuit 201 shown in FIG. 2, since the first and second reference clock signals RefCLK 1 and RefCLK 2 applied to the first and second voltage control delay units 831 and 832 are differential signals and clock signals output from the first and second voltage control delay units 831 and 832 are also differential signals.
FIG. 9 is a block diagram illustrating the second loop 813 of FIG. 8 in further detail according to an illustrative embodiment of the invention. Referring to FIG. 9, the controller 861 includes a charge pump 875 , a boundary detector 871 and a state decoder 873 . Each of the first and second voltage control delay units 831 and 832 includes seven delay elements. A voltage control delay unit for outputting a selected clock signal iCLK, and a voltage control delay unit for outputting non-selected clock signals, are controlled by different voltages. If clock signals CLK 3 and CLK 4 output from the second voltage control delay unit 832 are selected, the second voltage control delay unit 832 is provided with a control voltage VC from the controller 861 , while the first voltage control delay unit 831 is provided with a reference voltage Vref. The first voltage control delay unit 831 outputs first and second clock signals CLK 1 and CLK 2 of differential types having a 180° phase difference, and the second voltage control delay unit 832 outputs the third and fourth clock signals CLK 3 and CLK 4 of differential types having 90° phase differences with respect to the first and second clock signals CLK 1 and CLK 2 , respectively.
The boundary detector 871 determines whether to increase or decrease a current selection code, using the phase relationship between the first through fourth clock signals CLK 1 through CLK 4 . The state decoder 873 receives the output of the boundary detector 871 and determines a next selection code from the current selection code, so as to control the multiplexer 241 . The output signal of the phase detector 251 drives the charge pump 875 . The delay amount of a selected voltage control delay unit is controlled by the control voltage VC generated by the charge pump 875 , and the delay amount of the other unselected voltage control unit is controlled by the reference voltage Vref.
FIG. 10 is a phase diagram illustrating a delay control method performed by the second loop 813 of FIG. 8 according to an illustrative embodiment of the invention. In the case where the first clock signal CLK 1 is selected, when the first clock signal CLK 1 is consistent with the third clock signal CLK 3 having a 90° phase due to an increase in its delay amount, it is switched to the third clock signal CLK 3 . In the same case, when the first clock signal CLK 1 is consistent with the fourth clock signal CLK 4 having a 90° phase due to a decrease in its delay amount, it is switched to the fourth clock signal CLK 4 . Here, the first and second clock signals CLK 1 and CLK 2 maintain a 180° phase difference between them since they are differential signals, and the third and fourth clock signals CLK 3 and CLK 4 also maintain a 180° phase difference between them since they are differential signals. As described above, the delay range of the first clock signal CLK 1 is between −90° and +90°, so that the clock synchronization circuit 801 provides a wider delay range than the delay range provided by the clock synchronization circuit 201 of the first embodiment (FIG. 2 ).
The clock synchronization circuit 801 can cover the entire phase region since continuous switching can be made at the clock boundary between two signals of the clock signals CLK 1 through CLK 4 , similar to the clock synchronization circuit 201 shown in FIG. 2 . In the clock synchronization circuit 801 , each of the first and second voltage control delay units 831 and 832 has a greater number of delay elements than the number of delay elements included in each of the first through fourth voltage control delay units 231 through 234 in the clock synchronization circuit 201 of FIG. 2 . However, the total number of delay elements in the clock synchronization circuit 801 is smaller than that of the delay elements in the clock synchronization circuit 201 .
The clock synchronization circuits 201 and 801 according to the first and second embodiments of the present invention, respectively, can be realized in semiconductor devices, in particular, in SDRAM semiconductor devices.
As described above, the clock synchronization circuits 201 and 801 according to the present invention each having a dual loop include voltage control delay units 231 through 234 and voltage control delay units 831 and 832 , respectively, such that the influence of dynamic noise is reduced and jitter performance is enhanced.
Although the illustrative embodiments have been described herein with reference to the accompanying drawings, it is to be understood that the present system and method is not limited to those precise embodiments, and that various other changes and modifications may be affected therein by one skilled in the art without departing from the scope or spirit of the invention. All such changes and modifications are intended to be included within the scope of the invention as defined by the appended claims.
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A clock synchronization circuit is provided for synchronizing an external clock signal with an internal clock signal. The circuit is connected to a clock buffer adapted to output the internal clock signal. The circuit includes a first loop adapted to receive the external clock signal and output a plurality of reference clock signals having a predetermined phase difference therebetween. A second loop is adapted to delay the plurality of reference clock signals; select a signal from among the plurality of delayed reference clock signals; provide the selected signal to the clock buffer; detect a phase difference between the internal clock signal output from the clock buffer and the external clock signal; generate a plurality of control voltages to reduce the detected phase difference, and control a delay amount of each of the plurality of reference clock signals in response to the plurality of control voltages; so as to synchronize the internal clock signal with the external clock signal.
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CROSS-REFERENCES TO RELATED APPLICATIONS
[0001] This application is a continuation-in-part application of U.S. application Ser. No. 09/842,992 filed Apr. 26, 2001, which is incorporated herein by reference.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] This invention relates generally to a soldering iron and, more particularly, to a soldering iron having a releasable and replaceable cartridge and associated handle that may be replaced with a customized handle for a particular user.
[0004] 2. General Background and State of the Art
[0005] Cartridge type soldering irons have been in use for a number of years. One example of a cartridge type soldering iron is disclosed in U.S. Pat. No. 4,839,501. As disclosed therein, there is a replaceable cartridge and associated rigid handle. One of the problems with a soldering iron with a replaceable cartridge as shown in the U.S. Pat. No. 4,839,501 is that it is not comfortable for every user. That is, if a user does not like the size or shape of the handle of a soldering iron, the user has to either find another iron that is more comfortable or continue to use the uncomfortable soldering iron. Moreover, a soldering iron may be handled by a number of users, which can cause hygiene problems. This is especially true because most germs are transmitted via human hands.
[0006] Therefore, there is a need for a cartridge type soldering iron having a handle that can be fitted to a particular user and, at the same time, minimize any hygiene problems being caused by a number of users handling the same soldering iron.
INVENTION SUMMARY
[0007] The present invention solves the aforementioned problems with a cartridge type soldering iron by providing a handle that is releasable from the soldering iron cartridge and replaceable with a handle that is more comfortable to the user. This allows a user to select a handle that is ergonomically friendly to his hand and replace it with the replaceable handle that is design to fit the soldering iron cartridge. There are a number of advantages to the present invention. One of the advantages is that a user can choose its own handle with the desired, shape, size, color, and material. Another advantage is that since each user has its own handle, hygiene problems may be minimized. Still another advantage is the cost savings because as the replaceable handle wares out, only the handle needs to be replaced rather than the whole soldering iron.
[0008] The above described and many other features and attendant advantages of the present invention will become apparent from a consideration of the following detailed description when considered in conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0009] A detailed description of exemplary embodiments according to the invention will be made with reference to the accompanying drawings.
[0010] [0010]FIG. 1 is an exemplary view of an assembled soldering iron in accordance with one embodiment of the present invention;
[0011] [0011]FIG. 2 is an exemplary view of a disassembled soldering iron of FIG. 1;
[0012] [0012]FIG. 3 is an exemplary view of a disassembled soldering iron in accordance with an alternative embodiment of the present invention;
[0013] [0013]FIG. 4 is an alternative embodiment of a connector;
[0014] [0014]FIG. 5 is yet another alternative embodiment of a connector;
[0015] [0015]FIG. 6A is an exemplary view of an alternative embodiment of the present invention;
[0016] [0016]FIG. 6B is an exemplary cross-sectional view of the embodiment illustrated in FIG. 6A; and
[0017] [0017]FIG. 7 is an exemplary view of a sleeve and handle illustrated in FIG. 6A coupled to a substantially similar connector illustrated in FIG. 1.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0018] This description is not to be taken in a limiting sense, but is made merely for the purpose of illustrating the general principles of the invention. The section titles and overall organization of the present detailed description are for the purpose of convenience only and are not intended to limit the present invention.
[0019] [0019]FIG. 1 illustrates by way of example a soldering iron cartridge 10 (cartridge) having a sleeve 12 disposed within an insulator 14 , which is also disposed within a releasable handle 16 . This assembly is further adapted to electrically connect to a connector 18 having a cord extending to a plug 48 .
[0020] [0020]FIG. 2 illustrates by way of example the cartridge 10 disassembled. The sleeve 12 has a proximal end 22 and a distal end 20 . The proximal end 22 is adapted to couple to a connector end 24 having electrical contact areas 26 and 26 ′. The distal end of the sleeve 12 is adapted to couple to a tip 28 which is designed to concentrate the heat generated by the electrical heating elements 30 within the sleeve 12 (not shown). That is, the electrical energy supplied to the electrical heat element 30 via the electrical contact areas 26 and 26 ′ are converted into heat and focused along the tip 28 . Optionally, the sleeve 12 may have a notch 32 along the surface of the sleeve 12 so that it may be used to position the insulator 14 at a predetermined position relative to the sleeve 12 , as further discussed below.
[0021] As illustrated by way of example in FIG. 2, the insulator 14 has an opening 34 running axially therethrough. The shape of the opening 34 may be substantially similar to the outer configuration of the sleeve 12 . Once the sleeve 12 is inserted through the opening 34 , the cartridge 10 may be firmly held in place. Moreover, within the opening 34 may be a tooth 36 which is adapted to engage with the notch 32 thereby positioning the insulator 14 relative to the sleeve 12 in a predetermined position. Additionally, the sleeve 12 may be fixed or releasably held within the opening 34 of the insulator 14 .
[0022] Optionally, the insulator 14 may have an outer ring 38 which is made of temperature-sensitive material. That is, as the sleeve 12 near the tip 28 gets hot, the outer ring 38 may indicate such a rise in temperature by varying its color, depending on the temperature of the sleeve. This way, a user may be warned that the soldering iron is hot. Moreover, the length of the insulator 14 may be sized so that it is less than the length of the sleeve between its proximal and distal ends.
[0023] [0023]FIG. 2 also illustrates an exemplary handle 16 having a hole therethrough along the longitudinal axis. The configuration of the hole 40 may be substantially similar to the outer configuration of insulator 14 . Once the insulator 14 is inserted into the hole 40 , it snugly fits into the hole 40 and it is removable. The outer circumference of the handle 16 may vary in size, shape, and may be made of a variety of materials with different degrees of firmness. This allows a particular user to pick a handle that is ergonomically comfortable to grip. Because each user may have his own handle 16 , the hygiene problem is minimized. Cost-wise, when the handle 16 wears out, rather than replacing the whole soldering iron cartridge 10 , just the handle 16 may be replaced. The handle 16 may be made of foam and may be carbon impregnated to allow static discharge. Moreover, the handle 16 , may be washable. Of course, the handle 16 may be made of a variety of materials known to those skilled in the art including rubber, elastomers, and plastics.
[0024] [0024]FIG. 2 further illustrates by example the connector 18 having a receptacle opening 42 therein. Within the receptacle opening 32 are electrical contact fingers 44 positioned to make electrical contact with the electrical contact areas 26 and 26 ′ of the connector end 24 . That is, once the connector end 24 is inserted into the receptacle opening 42 , electrical contact fingers 44 make electrical contact with the electrical contact areas 26 and 26 ′. Connector 18 also includes a cord 46 which is coupled to a plug 48 which is adapted to insert into an electrical outlet. Note that the length of the handle 16 is designed to fit flush against the outer ring 38 and fit flush against the opposite end. This way, once the connector end 24 is inserted into the receptacle opening 42 , the connector, connector end, and the handle are flush against each other.
[0025] [0025]FIG. 3 illustrates by example an alternative embodiment of the present invention wherein the sleeve 12 is inserted into a hole 40 ′ of the handle 16 ′. In this embodiment, the insulator 14 is eliminated, unlike the previous embodiment in FIG. 2. The sleeve 12 may be releasable from the handle 16 ′, and the handle 16 ′ may have a tooth 50 adapted to associate with the notch 32 of the sleeve 12 to position the handle 16 ′ relative to the sleeve 12 at a predetermined position. One of the reasons for not needing the insulator 14 is that much of the heat is focused near the distal end 20 and minimal heat is conducted back along the sleeve 12 to the location of the notch 32 , so that a handle 16 ′ made of foam would not degrade due to the heat. Of course, the hole 40 ′ is now sized to be substantially similar in dimension to the configuration of the sleeve 12 . Moreover, the handle 16 ′ may have an outer ring 38 ′ to indicate the temperature of the outer ring 38 ′.
[0026] With regard to the cross-section of the sleeve 12 , it may have a variety of cross-sectional shapes such as circular, oval, square, or rectangular. The hole 40 ′ however need not be similar to the cross-sectional area of the sleeve 12 , although at least a portion of the hole 40 ′ is used to engage the outer surface of the sleeve 12 to somewhat firmly hold the sleeve 12 in its predetermined position. As such, air passageways may be formed between the handle 16 ′ and the sleeve 12 to radiate the heat away from the handle 16 ′. Of course, the cross-section of the hole 40 ′ may correspond to the cross-section of the sleeve 12 to make continuous contact between the handle 16 ′ and the surface of the sleeve 12 .
[0027] [0027]FIG. 4 illustrates by way of example an alternative way of coupling the cord 46 to the connector 18 . In this embodiment, the cord 46 is coupled to the connector 18 at about a 45° angle so that it may be more comfortable for a user to hold the cartridge 10 . Still further, as illustrated by way of example in FIG. 5, the core 46 may be coupled to the connector 18 at about a 90° angle to each other for application in which such relationship would aid the user in using the cartridge 10 more comfortably.
[0028] [0028]FIGS. 6A and 6B illustrate still another alternative embodiment of the present invention wherein the sleeve 12 ′ is inserted into a hole 40 ″ of a handle 16 ″. In this embodiment, the sleeve 12 ′ has a ring 38 ″ at a predetermined position to act as a stopper along a longitudinal axis of the sleeve 12 ′. Moreover, the handle 16 ″ is divided into two portions, a distal portion 52 and a proximal portion 54 . The distal portion 52 has a bore 50 adapted to receive the ring 38 ″. As such, as the distal end 22 ′ of the sleeve 12 ′ is inserted through the bore 50 of the distal portion 52 , the ring 38 ″ acts as a stopper to prevent the handle 16 ″ from moving further toward the distal end 20 ′ of the sleeve 12 ′. This ensures that the handle 16 ″ is correctly positioned relative to the sleeve 12 ′. Moreover, the outer configuration of the proximal portion 54 may be sized for a particular user, as such, the outer configuration of the proximal portion 54 may be smaller than the outer configuration of the distal portion 52 . Conversely, the outer configuration of the distal portion 52 may be greater than the proximal portion 54 .
[0029] To assemble the cartridge illustrated in FIGS. 6A and 6B, a user first selects from a variety of handles which are most comfortable for the user. In other words, a user selects from a variety of handles having a different outer configuration along the proximal portion 54 designed for a particular user. Once a handle 16 ″ has been selected, the proximal end 22 ′ of the sleeve 12 ′ is inserted through the bore 50 until the ring 38 ″ stops the handle 16 ″ in its predetermined position. Then, the proximal portion 22 ′ is inserted into connector 18 until an electrical contact is made. This way, the cartridge illustrated in FIGS. 6A and 6B may be customized for a particular user. Moreover, in this embodiment, the sleeve 12 ′ is coupled to the connector 18 having a core that is at about a 45° angle relative to the longitudinal axis of the sleeve 12 ′. Alternatively, as illustrated in FIG. 7, a connector 18 having a core that is substantially in line with the longitudinal axis of the sleeve 12 ′ may be used as well.
[0030] In closing, it is noted that specific illustrative embodiments of the invention have been disclosed hereinabove. With respect to the claims, it is applicant's intention that the claims not be interpreted in accordance with the sixth paragraph of 35 U.S.C. § 112 unless the term “means” is used following by a functional statement.
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The present invention allows a user to select a handle that is ergonomically friendly to a user's hand and replace it with the replaceable handle that is designed to fit over a soldering iron rod. There are a number of advantages to the present invention. One of the advantages is that a user can choose an individual handle with the desired shape, size, color, and material. Another advantage is that since each user has an individual handle, hygiene problems may be minimized. Still another advantage is the cost savings because as the replaceable handle wears out, only the handle needs to be replaced rather than the whole soldering iron.
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BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention generally relates to wellhead components for supporting the use of downhole pumps. More particularly, the present invention relates to a top mounted rotating stuffing box configured for sealing production fluid from the atmosphere.
[0003] 2. Description of the Related Art
[0004] The present invention generally relates to wellhead components for The present invention generally relates to wellhead components for Oil and gas in newly discovered reservoirs usually flow to the surface by natural lift. The natural formation pressure of a reservoir provides the energy or driving force to move reservoir fluids horizontally into a wellbore, through production tubing, and through surface processing equipment. During the life of any producing well, however, the natural reservoir pressure decreases as reservoir fluids are removed from the formation. As the natural downhole pressure drops to the sum of the hydrostatic head in the wellbore and the facility pressure, the fluids cease to spontaneously flow to the surface. Therefore, artificial lift methods such as sucker-rod pumping, downhole pumping, and gas injection lift techniques, for example, are employed to lift the fluids to the surface.
[0005] Many wells today use a downhole pumping apparatus such as progressing cavity pump (PCP) systems to lift fluids from within the production well to the surface. As its name implies, a PCP system comprises a PCP, also referred to herein as “pump”, located within the wellbore and a drive system located at the surface of the well. A drive system comprises, among other components, a motor (typically a hydraulic motor) for providing torque and rotation to a drive string, and a drive unit for transmitting the torque downhole. A drive string disposed within the production tubing connects the pump and hydraulic motor. The pump comprises a rotor disposed within a stator located within the production tubing. The well is produced by utilizing the hydraulic motor to rotate the drive string, which, in turn, drives the rotor of the pump. The result is a non-pulsating positive displacement flow of fluids towards the surface of the well.
[0006] A major problem associated with downhole PCP implementations is sealing the pressurized production fluid and preventing it from escaping into the atmosphere from surface equipment. Often, stuffing boxes are used to help seal to the production fluid. Accordingly, numerous stuffing boxes for use with PCP implementations are available in the marketplace. Typically, the stuffing boxes are of the bottom mount variety. As the term “bottom mount” implies, the stuffing boxes are placed below the hydraulic motor and other components of the drive system. In many cases, the stuffing box is located beneath the drive system and directly above the wellhead.
[0007] The harsh operating environment of a PCP implementation necessitates regular servicing of stuffing boxes due to failed bearings and seals within. Servicing or replacing stuffing boxes prove to be difficult in the case of bottom mount stuffing boxes because they are difficult to gain access to. This is mainly because the drive system needs to be disconnected from the wellhead in order to remove the stuffing box.
[0008] There are some top mount stuffing boxes available in the marketplace, but they utilize rope packings as the primary seals. Those skilled in the art will understand that under rigorous conditions, rope type packings have a tendency to lose shape, or “weep”, which renders these packings ineffective for containing pressurized production fluids. Further, available top mounted stuffing boxes tend to damage other components of the drive system, such as a drive unit.
[0009] Therefore, there is a need for a top mounted stuffing box that allows for quick installation or removal without requiring the removal of other components of the drive system, such as the hydraulic motor or the drive unit. There is a further need for the stuffing box to contain seals that are more reliable and wear resistant than those known in existing stuffing boxes known in the art. There is yet a further need for the stuffing box to mate with other components of the drive system in a manner that will not damage these components.
SUMMARY OF THE INVENTION
[0010] In one respect, the present invention provides a downhole pump implementation. The downhole pump implementation comprises a drive string and a drive system comprising a top mounted rotating stuffing box, wherein the top mounted rotating stuffing box rotates with the drive string. The downhole pump implementation also includes a downhole progressing cavity pump.
[0011] In another respect, the present invention provides a method of replacing a stuffing box. The method includes providing a wellhead and a drive system, wherein the drive system comprises a top mounted rotating stuffing and a drive unit. The method also includes providing a safety clamp for securing the weight of the drive string. The method also includes shutting down the well, securing the weight of the drive string by placing the safety clamp on an exposed portion of the drive string at the surface and holding the drive unit stationary. The method also includes rotating the stuffing box a quarter turn in either direction, relative to the drive unit and lifting the stuffing box upwards and removing the stuffing box from the drive system.
[0012] In yet another respect, the present invention provides an assembly for pumping fluid. The assembly includes a top mounted rotating stuffing box, an upper stand pipe and a lower standpipe. The assembly also includes a drive system comprising a drive unit, and a drive string.
BRIEF DESCRIPTION OF THE DRAWINGS
[0013] So that the manner in which the above recited features, the advantages and objects for the present invention can be more fully understood, certain embodiments of the invention are illustrated in the appended drawings.
[0014] FIG. 1 is a cross-sectional view of a wellbore illustrating a rotating stuffing box, hydraulic, motor, drive unit and Progressing Cavity Pump (PCP) in accordance with one embodiment of the present invention.
[0015] FIG. 2 is a cross-sectional view of a rotating stuffing box, drive unit and hydraulic motor according to one embodiment of the present invention.
[0016] FIG. 3 is a detailed cross-sectional view of a rotating stuffing box and a portion of a corresponding drive unit according to one embodiment of the present invention.
[0017] FIG. 4 is a detailed cross-sectional view of a drive unit according to one embodiment of the present invention.
[0018] FIG. 5 illustrates the configuration of a lower standpipe, standpipe base and integral housing according to one embodiment of the present invention.
[0019] FIG. 6 illustrates an exterior view of a rotating stuffing box and drive unit according to one embodiment of the current invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0020] The apparatus and methods of the present invention, in the context of downhole pump implementations, provide the sealing of production fluid from the environment using a top-mounted rotating stuffing box.
[0021] The discussion below focuses primarily on utilizing top-mounted rotating stuffing boxes together with a split standpipe configuration for use with downhole pump implementations, such as progressing cavity pumps (PCP's). The principles of the present invention also allow for the quick installation or removal of the stuffing box without the need to remove other components such as a corresponding drive unit belonging to a drive system.
[0022] FIG. 1 presents a cross-sectional view of a wellbore 5 . As illustrated, the wellbore 5 has a string of casing 30 fixed in the formation 6 by cured cement 7 . The wellbore 5 also includes a downhole PCP implementation in accordance with one embodiment of the present invention. Surface components of the PCP implementation include a hydraulically powered drive system 10 and composite pumping tree 20 . Downhole components of the PCP implementation include a drive string 40 , PCP 60 and an anchor 80 .
[0023] Surface based drive systems, and more specifically hydraulic motor based drive systems, have been used with downhole PCP's for more than two decades. These systems are ideal for applications requiring precise torque control and adjustable wellhead speed. Referring back to FIG. 1 , the drive system 10 , which includes the hydraulic motor 11 , suspends and rotates a drive string 40 that, in turn, operates a downhole PCP 60 . The drive system 10 also comprises a stuffing box 100 and a drive unit 200 according to one embodiment of the present invention; these components will be described in more detail with reference to FIGS. 2, 3 and 4 .
[0024] Below the drive system 10 is a composite pumping tree 20 (also referred to herein as a wellhead), which typically comprises high and low pressure rams to manage the pressure of the production fluid and to keep the fluid from escaping into the atmosphere from the interface between the wellhead and the remainder of the wellbore components below.
[0025] The wellbore 5 also comprises casing 30 that is located below the wellhead and extends downhole to the production zone. Those skilled in the art will appreciate that a wide variety of casing (e.g., different sizes, materials, etc.) is available in the marketplace. In the context of the present invention, it should be understood that the casing extends from the wellhead 20 to below the PCP 60 . In other words, the drive string 40 and PCP operate within the casing 30 .
[0026] The drive string 40 may comprise multiple polished rods 41 and sucker rods 42 connected to each other via threaded couplings 43 . Polished rods 41 are manufactured to tight tolerances and therefore have exceptionally uniform outer diameters that are polished to facilitate a pressure seal at the interface between the polished rod and the stuffing box 100 . Sucker rods 42 are similar to polished rods 41 , but do not provide the polished surfaces, as they are not meant to interact with seals. Sucker rods 42 are threaded on each end and are manufactured to dimension standards and metal specifications set by the petroleum industry, typically their lengths are between 25 to 30 feet and the diameter varies from ½ to 1⅛ inches.
[0027] The Progressing Cavity Pump 60 may be located directly below the sucker rods 42 . Typically, PCP's 60 comprise a single helical-shaped rotor 62 that turns inside a double helical elastomer-lined stator 61 . The stator 61 is attached to the production tubing string 50 above and remains stationary during pumping. It is quite common for External Upset Ends (EUE) type tubing to be utilized as production tubing 50 . As stated earlier, the rotor 62 may be attached to the drive string 40 which is suspended and rotated by the drive system at the surface. As the rotor 62 turns eccentrically in the stator 61 , a series of sealed cavities form and progress from the inlet to the discharge end of the pump 60 . The result is a non-pulsating positive displacement flow of production fluid with a discharge rate proportional to the size of the cavity, rotational speed of the rotor 62 and the differential pressure across the pump 60 .
[0028] For one embodiment, fluid is directed to the inlet of the PCP 60 via a tagbar 70 . Connected below the tagbar 70 is an anchor 80 , which restricts the stator 61 and production tubing 50 from rotating. In other words, the anchor provides for relative rotation between the stator 61 and rotor 62 , thereby allowing the pump to urge production fluid uphole.
[0029] FIG. 2 presents a cross-sectional view of a hydraulic drive system 10 comprising a hydraulic motor 11 , rotating stuffing box 100 , and drive unit 200 according to one embodiment of the present invention. An integral housing 250 connects the drive system 10 to the wellhead 20 below. The stuffing box 100 is installed at the top of the main shaft 210 of the drive unit 200 . For one embodiment, a drive gear 12 is coupled to the main shaft 210 via the main shaft slot 215 . The main shaft slot 215 allows for torque supplied by the hydraulic motor 11 to be transferred through the main shaft 210 . The stuffing box 100 and the manner in which it interfaces with the top of the main shaft 210 will be described in detail with reference to FIG. 3 , and the drive unit 200 will be described in more detail with reference to FIG. 4 .
[0030] FIG. 3 is a detailed cross-sectional view of a rotating stuffing box 100 and a portion of a corresponding drive unit 200 according to one embodiment of the present invention. A top sub 101 is installed at the top of the stuffing box 100 assembly and threadedly connects with a stuffing box housing 102 below. It should be noted that for some embodiments, other configurations of a top sub 101 could be utilized. For example, if it is desired to attach additional pieces of equipment above the stuffing box 100 , the upper portion of top sub 101 may be configured with a threaded connection to allow for other tools to be threadedly connected above the top sub 101 .
[0031] An upper standpipe 103 is located entirely within the stuffing box 100 and a corresponding lower standpipe 104 extends below from a bore in the stuffing box 100 . The upper standpipe 103 and lower standpipe 104 comprise dogs 104 B designed to prohibit rotational movement between the upper standpipe 103 and lower standpipe 104 . In other words, the upper 103 and lower 104 standpipes do not rotate relative to each other. This interface between the upper and lower standpipes will be described further with reference to FIG. 6 .
[0032] The arrangement of the upper standpipe 103 , lower standpipe 104 and standpipe seal 105 should be noted. As described earlier, there is no rotational movement between the upper standpipe 103 and lower standpipe 104 . In terms of axial movement between the upper standpipe 103 and lower standpipe 104 , the dogs 104 B ensure that there is very little relative movement (if any) during normal operation. Therefore, it is possible for the standpipe seal 105 to be a standard O-ring rather than a packing, which is typically used by existing tools. The standpipe seal 105 , placed within the interface of the upper standpipe 103 and lower standpipe 104 , prevents production fluid from leaking from escaping to the various annular gaps of the stuffing box 100 and the surrounding atmosphere.
[0033] As stated earlier, during operation, components of the drive string 40 , such as the polished rod 41 , are positioned in the bore of the stuffing box 100 and drive unit 200 . Also, the downhole pump 60 is ensures that pressurized production fluid is being urged towards the surface through the annular space between the drive string 40 and the production tubing 50 . At the surface, the production fluid continues to be urged upward through the annular surface between the drive string 40 and the inner bore of the lower standpipe 104 and upper standpipe 103 .
[0034] The polished rod packing 112 prevents production fluid from escaping from the annular space between the polished rod 41 and the stuffing box 100 . It should be noted that the annular spaces between the upper standpipe 103 and the stuffing box housing 102 are also pressurized by the production fluid.
[0035] In other words, the region above loaded lip seal assembly 107 is pressurized to the same pressure as the production fluid in the bore of the stuffing box assembly 100 . As a result, the loaded lip seal assembly 107 is forced downwards towards a standpipe packing 108 . In the process of moving downwards, the loaded lip seal assembly 107 pressurizes grease located immediately below in region 107 B, to the production fluid pressure.
[0036] The result is that the standpipe packing 108 is under the same pressure as the production fluid. Those skilled in the art will acknowledge that a balanced seal implementation, such as the one described above, facilitates better performance of seals and packings such as the standpipe packing 108 , which extends operating life of the stuffing box assembly 100 . Particularly, a balanced seal configuration helps to prevent problems with packings such as “weep” associated with many rope type packings used in existing stuffing boxes.
[0037] A variety of sealing elements including the O-ring assemblies 106 and lower loaded lip seal assembly 116 are also utilized to prevent production fluid from escaping from annular areas within the stuffing box housing 102 . The attributes and functionality of these additional sealing elements listed above are understood by those skilled in the art. They will also appreciate that many different varieties and configurations of sealing elements may be used in other embodiments of the present invention, as dictated by requirements of the specific application.
[0038] During operation, as the drive string 40 rotates, it may sway and whip, which will intermittently impart a transverse load against the stuffing box assembly 100 , and more specifically to components such as the stuffing box housing 102 . Accordingly, the stuffing box housing 102 will impart a corresponding transverse load against a standpipe bearing 109 that separates the stuffing box housing 102 and the upper standpipe 103 . The standpipe bearing 109 is designed to accept the transverse loading and will facilitate smooth relative rotation between the stuffing box housing 102 (which is rotating with drive string 40 ) and the upper standpipe 103 while minimizing separation between the stuffing box housing 102 and the upper standpipe 103 . A separation would result in leakage of the production fluid.
[0039] Grease zerks 110 are provided to allow for the injection of grease (and/or other lubricants) into the annular areas formed between the upper standpipe 103 and the stuffing box housing 102 . Plugs 111 are utilized to retain the lubricants in the annular areas contained within the stuffing box assembly 100 .
[0040] In addition, a polished rod packing 112 is provided. During operation, the polished rod 41 components of the drive string will be adjacent to this packing. A spacer 113 installed directly below ensures the packing will seal properly against the polished rod 41 during operation.
[0041] As described with reference to FIG. 1 , the drive string 40 is lowered through the stuffing box 100 and the remainder of the drive system 10 . A bushing 114 placed within the top portion of the upper standpipe 103 provides a guide for the drive string as it is lowered through the drive unit and as the drive string rotates in place (without axial movement) during pump operation. The bushing 114 prevents the drive string 40 from coming in contact with the upper or lower standpipes. Further, the bushing 114 assists in keeping the drive string 40 axially parallel with the stuffing box 100 assembly—this assists the rod packing 112 in preventing leakage of the production fluid.
[0042] It should be noted that the lower portion of the stuffing box housing 102 fits inside the top portion of the main shaft 210 . A hexagonal profile is provided at the bottom of the stuffing box housing 102 . A corresponding hexagonal opening is provided at the top of the main shaft 210 . The interface between the stuffing box housing 102 and the main shaft 210 allows for quick and simple installation and removal of the stuffing box 100 from the drive system 10 , and will be discussed in more detail with reference to FIG. 6 .
[0043] FIG. 4 provides a detailed view of the drive unit 200 . The entire lower standpipe 104 is shown. As can be seen, the lower standpipe 104 extends through the bore of the main shaft 210 and is anchored in the standpipe base 220 . As mentioned earlier, the upper standpipe 103 and lower standpipe 104 do not rotate with the drive unit 200 . The standpipe base 220 is secured within the top portion of the integral housing 250 .
[0044] FIG. 5 provides a detailed view of the interface between the lower standpipe 104 and the standpipe base 220 , and the interface between the standpipe base 220 and the integral housing 250 . The lower standpipe 104 is press fit into the standpipe base 220 —this ensures that the lower standpipe 104 does not rotate along with the main shaft 210 . The standpipe base 220 is placed in the integral housing 250 . The standpipe base comprises dogs 221 that fit into recesses 251 , ensuring that the standpipe base 220 does not move relative to the integral housing 250 .
[0045] Referring back to FIG. 4 , it can be seen that the main shaft 210 is supported by upper bearings 216 and lower bearings 218 . As is typical of other units known in the art, the drive unit 200 according to embodiments of the present invention is configured to support the weight of the entire drive string 40 and pump 60 . During operation, upper bearings 216 are utilized to manage transverse loading, and lower bearings 218 are designed to counteract both transverse and axial loading. Essentially, upper bearings 216 and lower bearings 218 allow for smooth and uninterrupted rotation of the drive unit, drive string 40 and pump 60 .
[0046] The stuffing box 100 is mounted on top of the main shaft 210 . FIG. 6 illustrates an external view of the interface between the stuffing box 100 and the main shaft 210 , and more specifically the corresponding hexagonal profiles, labeled with reference numbers 175 and 275 , on the bottom of the stuffing box 100 and the top portion of the main shaft 210 , respectively. The hexagonal profile on each of these components facilitates the quick removal of the stuffing box from the drive system 100 .
[0047] For instance, the stuffing box assembly 100 can be removed by being turned approximately a quarter of a turn (in either direction) in a manner to allow for the hexagonal profile on the bottom of the stuffing box housing 102 to be matched with the hexagonal profile of the top portion of the main shaft 210 . Once the profiles are matched up, the stuffing box 100 can be lifted axially upward relative to the main shaft 210 and removed. In other words, if the hexagonal profiles are not matched up, the stuffing box remains locked linearly onto the main shaft 210 .
[0048] Accordingly, in order to install the stuffing box 100 onto the drive unit 200 , the hexagonal profiles first need to be matched. Next, the stuffing box should be lowered onto the main shaft 210 of the drive unit 200 . Finally, the stuffing box 100 needs to be turned a quarter turn in either direction in order to be locked into place.
[0049] To demonstrate the advantages offered by embodiments of the present invention in the context of PCP implementations, procedures for replacing a conventional bottom mounted stuffing box and a top mounted stuffing box according to one embodiment of the present invention are described and compared below.
[0050] As stated earlier, bottom mounted stuffing boxes are typically installed between the drive unit and wellhead. In order to replace a bottom mounted stuffing box, the first step is to shutdown the well by following safe shutdown procedures. Next, the weight of the drive string is taken off the drive unit and is supported by a flushby truck or separate winch. Next, the entire drive system (including the hydraulic motor and drive unit) is disconnected from the wellhead; the drive unit is lifted out of the way with yet another winch line or picker. Next, the drive string is secured by setting a safety clamp (such as that described in commonly owned U.S. Pat. No. 6,557,643) on the polished rod that is exposed between the suspended drive system and wellhead. At this point, the safety clamp can be relied upon to maintain the weight of the drive string 40 . Next, with the secondary winch line or picker truck, the entire drive system 10 can be lifted up and over the drive string 40 . Finally, the bottom mount stuffing box is accessible and it is possible to remove the bottom mount stuffing box and replace it with another stuffing box. In order to resume operations, all the steps listed above would have to be performed in reverse to reinstall the drive system onto wellhead.
[0051] In contrast, a top mounted stuffing box, according to embodiments of the present invention, can be replaced easily without disconnecting the drive system from the wellhead. First, the well is shutdown according to the proper procedures. Next, a safety clamp can be used to support the weight of the drive string below the stuffing box 100 . Finally, the stuffing box is turned approximately a quarter turn in either direction, lifted upwards and removed from the drive system 10 .
[0052] Accordingly, the stuffing box is installed by matching the hexagonal profiles on the bottom of the stuffing box 100 and the top of the drive unit 200 . Next, the stuffing box 100 is lowered until corresponding tabs 104 B of the upper standpipe 103 and lower standpipe 104 make contact. Finally, the stuffing box 100 is turned a quarter turn in either direction to ensure that the stuffing box is locked onto the drive system.
[0053] A top mounted rotating stuffing box implemented according to embodiments of the present invention provides a variety of benefits including quick and easy installation or replacement, better sealing performance and longer operating life. The split standpipe configuration described herein facilitates ease of installation, while a balanced seal configuration improves sealing performance and extends operating life. Further, the balanced seal configuration allows for avoiding problems (such as weep) and the relatively short operating life associated with conventional rope packings. In addition, the top mounted stuffing box of the present invention is configured to interface with a drive unit (belonging to a drive system) in a manner that does not damage the drive unit as do many existing stuffing boxes. Accordingly, the top mounted -rotating stuffing box described above with reference to embodiments of the present invention provides numerous advantages over existing stuffing boxes available in the marketplace.
[0054] While the foregoing is directed to embodiments of the present invention, other and further embodiments of the invention may be devised without departing from the basic scope thereof, and the scope thereof is determined by the claims that follow.
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A system comprising a top mounted rotating stuffing box is provided for use with downhole pump (e.g., Progressing Cavity Pump) applications. The system also includes a split standpipe configuration that allows the stuffing box to be quickly installed or removed as needed. The split standpipe feature combined with the top-mounted aspect of the stuffing box allow for the corresponding drive units to stay intact while the stuffing box is being installed or removed.
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1. Field of the Invention
The present invention relates generally to a weaving process and particularly to a hands only weaving process.
2. Background of the Invention
Weaving is an ancient process that has been used by a multitude of historical and contemporary civilization for aesthetic and functional purposes. The weaving looms that are available for use, whether of cardboard construction or mechanical structure, have similar limits in regard to ease of use, which often include issues related to size, convenience, and ability to operate the mechanisms. These limits prohibit opportunities for instruction as well as participation in the art and craft as it is difficult to keep the warp strands in place in the simpler of looms and complicated to set the warp strands in the more complicated looms. Furthermore, the weft strands tend to pull-in under the tension of the process generating unsatisfactory results. The cost alone of a loom can also be a major barrier for individual or educational use of the art and craft of weaving.
Some prior patents attempting to simplify the weaving process include U.S. Pat. No. 2,136,552 titled “Hand Loom,” issued to Page on Nov. 15, 1938; U.S. Pat. No. 2,527,333 titled “Toy Handweaving Device” issued to Raizen on Oct. 24, 1950; U.S. Pat. No. 2,601,715 titled “Weaving Device” issued to Simonds on Jul. 1, 1952; U.S. Pat. No. 6,149,437 titled “Method for making toys from pliant rods” issued to Corliss on Nov. 21, 2000 and U.S. Design Pat. No. D469,818 titled “Hand-Knitting Toy” issued to Asou on Feb. 4, 2003.
The devices shown in these patents present similar issues regarding ease of use. A loom is needed to implement the process of weaving. The “Weaving Device” and “Method for making toys from pliant rods” patents also call for a unique material to be used for the weaving process.
BRIEF SUMMARY OF THE INVENTION
The present invention provides a method for hands only weaving without a manufactured loom, which can allow for ease of use to enable participation in the art and craft of weaving. When performing the process of the present invention, the weaving strands should be kept on the fingers and the weaving can be allowed to cascade down the palm side of the hand as it grows. The present invention process can be practiced in a multiple of settings. The weaving can be created on any hand or foot or approximation thereof using as few as two or all of the appendages thereof. Though not considered limiting, the description of the present invention method for purposes of explanation will entail the application of the hand and the use of all of the digits as warp features for the weaving. Some general steps, which are discussed and further broken down into more steps, for the present invention hands only weaving process can include:
1. The induction of the strand as it is woven in this fashion. The strand can be attached to the loom (hand) by any known manner, such as, but not limited to, tying a loop on the end and placing it on one of the warp features (digits). The strand can then be woven over, under, and between the warp features (digits) until there are preferably at least two strands across each of the warp features (digits).
2. At least one strand can then be lifted over the other(s) and then removed from the end of the warp feature (digit).
3. At this point, more of the strand is woven into the loom in a manner stated in general step 1 until there are at least two strands across each warp feature (digit). The procedure stated in general step 2 is repeated. This procedure continues until there is a product that can measure from approximately ¼″ to indefinite length. If desired, an additional strand may be attached at the end of the previous with a square knot.
4. If there is an interruption to the weaving process, the generating loops can be secured with any known apparatus, such as, but not limited to, a paperclip, hair pin, bobby pin, safety pin, etc. to avoid unraveling of the weaving. The weaving can be continued simply by replacing the generating loops on the warp features (digits) and removing the securing apparatus.
5. The length and the width of the weaving can be modified by lacing the ends or sides of terminated rib of weavings together. These modifications enable the products of the present invention fingertip weaving to be created into many different articles.
When performing the steps of the present invention hands only weaving process, control should be maintained on the tightness or looseness of the weave by the placement of the weaving strands between the base knuckle joint by the hand to the tips of the fingers, and to allow the weaving to cascade down the palm side of the hand as it grows. The present invention process can be used to create many different articles, including, but not limited to, hats, scarves, blankets, nets, headbands, shawls, ponchos, sweaters, etc.
It is an object of the present invention to provide a hands only weaving process.
It is another object of the present invention to provide a hands only weaving process not requiring the use of any manufactured looms.
BRIEF DESCRIPTION OF THE DIAGRAMS
FIGS. 1–48 are perspective views illustrating, in detail, the various steps which can be used for the present invention hands only weaving process.
Some key figures include FIG. 3 which illustrates the use of both hands as the loom and shuttle for Hands Only Weaving. The dominant (working) hand serves as the shuttle; the non-dominant (holding) hand is the loom; FIG. 9 which illustrates the first step necessary to complete a row of Hands Only Weaving; FIG. 23 which illustrates the use of an object such as a paper clip to remove the weaving from the holding hand for storage when there is an intermission in the process; FIG. 30 which illustrates the beginning of modifications to the length of a given rib of Hands Only Weaving; and FIG. 44 illustrates the appearance of the weaving as the width has been increased as two ribs have been joined together.
DETAILED DESCRIPTION OF THE INVENTION
FIGS. 1–48 illustrate the various steps involved for the present invention hands only weaving process including the steps used to join two or more ribs to create the potential for fashioning the weaving into many different articles which includes, but is not limited to, blankets, sweaters, etc. Initially, to better understand the present invention process a list of terms, along with their definitions, will be provided: (1) Definitions for General Weaving Terms Include:
a. Loom—a structure that is used as a form for weaving.
b. Shuttle—a structure that is used to pass material through the weaving loom.
c. Warp—the part of a structure that is woven around.
d. Weft—the part of the weaving that is added to the warp.
(2) Terms Specially Defined for the Present Invention Hands Only Weaving Process Include:
Holding hand—the non-dominant hand which serves as the loom. Though not limiting, the left hand can serve as the holding hand for a right handed practitioner and the right hand can serve as the holding hand for a left handed practitioner.
Working hand—the dominant hand which serves as the shuttle. Though not limiting, the right hand can serve as the working hand for a right handed practitioner and the left hand can serve as the working hand for a left handed practitioner.
Loops—basic structure of the weaving. Used to perpetuate, terminate, and assemble the weaving and related weaving products.
Tail—the originating end of the weaving.
Head—the generating end of the weaving from which the process may be secured, continued or terminated.
Rib—any segment of weaving, can be of any length.
Run—one set of weaving the thread over and under the digits. There can be four complete runs to begin the weaving and two complete runs to create a row. This can also be referred to as a pass.
Row—this is a completed set of runs, especially when the weft threads have been taken off and over the tips of the fingers which serve as the warp features.
Warp features—the digits of the holding hand in fingertip weaving. The digits are referred to as the pinky, ring, middle, index, and thumb.
(3) Description of the Hands Only Weaving Process
a. Beginning the Weave
As seen in FIGS. 1 and 2 the process begins with a simple loop that will fit onto the designated finger, such as, but not limited to, the pinky finger. The holding hand becomes a weaving loom at this point as the loop is placed upon the pinky. An alternative to providing a loop can be wrapping the strand around the pinky two or three times counter clockwise. In FIGS. 3 and 4 the weaving begins as the strand begins a run under the ring finger and over the middle finger, with the run continuing under the next warp feature. In this procedure that is the index finger, and the over the thumb. This completes the first run.
As seen in FIG. 5 the weaving continues with the second run under the thumb; over the index, under the middle, and over the ring finger. In FIG. 6 the third run is shown being made under and over the pinky then continuing the path under the ring, over the middle, and so on to the thumb. FIGS. 7 and 8 show the fourth and final run, which continues under the thumb and is completed over the index, under the middle, and over the ring where it rests as the next step is implemented.
As seen in FIG. 9 , in order to complete a row, the strands of the first and second runs can be lifted over the strands of the third and fourth runs and off of the tips of the digits (warp features). Beginning with the pinky the strand is lifted closest to the hand up and over the strand closest to the tip of that digit. In FIG. 10 the movement is shown continued to remove the strand off of the tip of that digit and release the hold. In FIG. 11 the motion is repeated to remove the strands closest to the hand over the strands closest to the tip of the related digit until all five digits have one strand remaining in place. A sequential method of moving from pinky to thumb can encourage consistency in technique to help in creating a uniform weave. By removing the strand indicated in this step, a “dropped loop” error can be eliminated. FIG. 12 shows that the weaving can be examined as it begins to generate on the palm side of the hand.
b. Continuing the Weave
As seen FIG. 13 the weave can be continued with a new run which can begin under, then over the pinky and under the ring. The pattern can continue until the strand is resting on the thumb. In Figure the second run is shown beginning under the thumb to follow through over the index. In FIG. 15 , the run is shown continuing the weaving pattern over to the ring where it can rest for the completion of a new row, similar to the row described in FIGS. 9–11 . As seen in FIG. 16 , snugly pulling on the tail reveals the definition of the rows of the weaving as the work progresses.
c. Tightening or Loosening the Weave
Throughout the weaving process, it may be necessary to either tighten or loosen the strand that is being used for the weaving. This may depend upon the nature of the fiber being used and the desired quality of the weave. The weaving can be tightened or loosened after the completion of a row. As seen in FIG. 17 , to tighten the weaving, the single strand in place on the middle finger can be gently pulled upon until it feels snug upon the pinky. The single strand remaining on the thumb can then be gently pulled to tighten the strand around the middle finger ( FIG. 18 ). The single strand remaining on the index can be gently pulled to tighten the strand around the thumb ( FIG. 19 ). The single strand remaining on the ring can be gently pulled to tighten the strand around the index.
As seen in FIG. 21 , the single strand handing from the ring can be gently pulled to tighten the strand on that digit. If the weaving needs to be loosened, the steps described above for FIGS. 17–21 can be performed in reverse order. Whether tightening or loosening the weaving, the amount of the strand increased in these steps can be controlled to help prevent the weave from becoming too loose or too tight. The quality of the weave can also be controlled with the placement of the strands upon the digits. The weaving can be tighter as it is placed closer to the fingernails. A larger weave can result as the weaving is placed closer to the base of the digits.
d. Securing and Storing the Weave
The weaving can be removed from the hand loom as needed and secured from unraveling with a variety of items. FIGS. 22–26 show the use of a securing device, such as a clip (i.e. paper clip, etc,) or pin (i.e. hair pin, etc.) as it is slipped into the loop on the pinky. Other common securing devices which will prevent unraveling, such as, but not limited to, other pins (i.e. bobby pins, safety pins, etc.) can also be used and are also considered within the scope of the invention. The pinky can be withdrawn from the weaving as the relative loop is in place upon the securing device. The securing device can be slipped into the loops of the successive digits which are then withdrawn from the weaving. Finally, the securing device can be slipped into the loop of the thumb. The thumb can then be withdrawn from its loop as the thumb loop is placed upon the securing device which is then bent back into shape to retain the head of the weaving. The weaving can be stored in a manner that prevents tangles to the product. The weaving may be replaced upon the hand loom by following the steps described for FIGS. 22–26 in reverse order. It is preferred to return the digit to the corresponding loop (begin with the thumb and ending with the pinky) prior to removing the securing device from that loop.
e. Terminating the Weave
The weaving may be terminated by cutting the strand that is hanging from the ring finger ( FIG. 27 ). As seen in FIG. 28 the cut end of the strand is shown taken through the loop on the pinky. The pinky can then be removed from the loop. This process can be continued through the loops of each of the fingers. The end of the strand can then be passed through the loop of the thumb as the thumb is removed from the loop ( FIG. 29 ). A gentle pull can be used to tighten the loops in the head of the weaving to help keep it secure.
f. Modifying the Length of the Weave
As seen in FIG. 30 any rib may be modified in length by cutting it preferably completely across in width. One fourth to one half of an inch in additional length can be retained to allow for the adjustment of the tail and the head, when preparing these parts for a product. Both cut ends may have many short, cut pieces ( FIG. 31 ). As seen in FIG. 32 , the cut pieces can be removed before the ends are prepared for a product. The new ends can become either a head or a tail, depending upon the proximity to the head and tail of the original rib ( FIG. 33 ). The end that becomes a head can have five loops that can be secured similar to the securement previously shown in FIGS. 28 and 29 . The head of the rib can be defined with five loops that can be secured by passing a strand through them ( FIGS. 34 and 35 ).
g. Adding to the Width of the Weave
As seen in FIG. 36 , two ribs may be joined together in a manner that will increase the width of the weaving. A tertiary strand can be tied or otherwise attached to the strand coming from the tail end of the rib from the loops on the side proximal to the second rib that will be attached to the first. It can be helpful to align the ribs so that the tails and heads are going the same direction. The first four loops on the side of the first rib that is to be attached to the second rib can be fitted onto the tips of the fingers, one loop for each finger ( FIG. 37 ). The thumb can remain free to assist in this process. Next, the first four loops on the side of the second rib that is to be attached to the first rib can be fitted onto the same finger tips ( FIG. 38 ). The strand discussed in FIG. 36 can then be guided into both sets of loops on the index finger (Finger 39 ). In beginning with the loops of the second rib that was placed on the finger to the other side of the loops of the first rib that was placed on the finger a consistent path can be maintained.
As the strand is passed completely through both sets of loops, the index finger can be removed from those loops ( FIG. 40 ). As seen in FIG. 41 , the joining strand can be passed through both sets of loops on each successive finger, with each successive finger being removed as the strand passed through, ending with the loops on the pinky. The next set of four loops can then be placed upon the corresponding fingers, always reserving the thumb to assist in the lacing process ( FIG. 42 ). The joining strand is passed through both sets on each finger as shown in FIGS. 39–41 . This process can be repeated until the desired width is achieved.
As seen in FIG. 43 , the joining strand can be secured by tying it to the strand existing from the head of the first piece that was used in this process. A gentle pull can define the weave pattern. The other side of the weave appears as a series of loops in distinct longitudinal rows ( FIG. 44 ).
h. Adding to the Length of the Weave or Creating a Band
The head and tail may be joined to either increase the length of a given rib or to create a band. Before this step is begun, the length of the strand extending from the head and the tail can be examined. Preferably, the length of the strand can be at least two or three inches longer than the width of the rib. If necessary, additional length can be tied or otherwise attached to this strand by conventional means, such as, but not limited to, using a square knot. Beginning with the head, the loops can be placed upon each digit relative to the order of the row ( FIG. 45 ). Preferably, the same loops can fit upon the digit it was generated upon.
FIG. 46 shows that it may be a little more difficult to fit the tail loops upon the digits. Thus, it is preferred to find the best fit for each of the loops. As seen in FIG. 47 the terminated strand can be threaded through each set of loops as they rest on each digit in a methodical, sequential manner. Next, the strand can be gently pulled as it passes through the loops on each digit to take up any slack. The digits can be removed from the loops and the lacing strand can be secured such as, but not limited to, by tying a square knot with it and the strand existing from the tail. As seen in FIG. 48 this process can create a band if connecting the head and tail of a given rib or can create a longer rib if connecting the heads and tails of more than one rib.
While the invention has been described and disclosed in certain terms and has been illustrated by disclosure of certain embodiments or modifications, persons skilled in the art who have acquainted themselves with the invention will appreciate that it is not necessarily limited by such terms nor to the specific embodiments and modifications disclosed herein. Thus, a wide variety of alternatives, suggested by the teachings herein, can be practiced without departing from the spirit of the invention and are also considered within the scope of the invention.
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A process for weaving that can be implemented using just the hands as the loom and shuttle, a weaving material such as yarn, an instrument for cutting like nail clippers or a small pair of scissors, and an object for intermissions in the process such as a paper clip. The weaving process is simplified to the most basic concepts of weaving that can be enjoyed by any age group, such as, but not limited to, from five-year-old children to adults. The absence of barriers like cumbersome weaving looms permits the process to be practiced in a multitude of settings.
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This is a continuation-in-part of U.S. Ser. No. 802,391, filed June 1, 1977, now U.S. Pat. No. 4,325,961.
BACKGROUND OF THE INVENTION
The present invention is concerned with novel substituted α-fluoromethyl-α-amino alkanoic acids.
An unsubstituted α-fluoromethyl-α-amino alkanoic acid, namely 2-fluoromethylalanine, having the formula: ##STR1## is known [Kollonitsch et al, J. Org. Chem., 40, 3808-9 (1975)]. No specific biological activity for this compound is suggested. This compound (A) is prepared by fluorodehydroxylation of the corresponding 2-hydroxymethylalanine.
α-Methyl amino acids, such as L-α-methyl-3,4-dihydroxyphenylalanine (α-methyldopa, an antihypertensive agent, are known to have decarboxylase inhibiting activity (Goodman, et al., The Pharmacological Basis of Therapeutics, Mac Millan Company, New York, N.Y. 1970, p. 577; Canadian Patent No. 737,907).
Novel substituted α-fluoromethyl-α-amino alkanoic acids have been discovered. These novel acids have decarboxylase inhibiting activity significantly greater than that of α-methyl amino acids.
SUMMARY OF THE INVENTION
Novel substituted α-fluoromethyl-α- amino alkanoic acids and esters thereof.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
An embodiment of the present invention is compounds having the formula ##STR2## wherein R is a substituted C 1 -C 4 alkyl group and R 1 is H or C 1 -C 18 alkyl.
The pharmaceutically acceptable acid addition salts of the formula I compounds are also included. In general, the salts are those of the formula I base with a suitable organic or inorganic acid. Preferred inorganic acid salts are the hydrohalides, e.g., hydrochlorides, hydroiodides, hydrobromides; the sulfates, and the phosphates. The hydrohalides, and especially the hydrochlorides, are more preferred.
The formula I compounds have a chiral center and may occur in optically active forms i.e., as optical isomers. These isomers are designated conventionally by the symbols L and D, + and -, l and d, S and R or combinations thereof. Where the compound name or formula has no isomer designation, the name or formula includes the individual isomer mixtures thereof and racemates.
The compounds having the S-isomer configuration are, in general, preferred.
R is a substituted alkyl group exemplified by ##STR3##
R 1 is H or C 1 -C 18 alkyl. Examples of suitable alkyl groups are methyl, octadecyl, 2-ethylhexyl, t-butyl, hexyl, isopropyl, ethyl, undecyl and the like; C 1 -C 6 alkyl is preferred and ehtyl is especially preferred. H is a most preferred definition of R 1 .
Preferred compounds of formula I are those where R is ##STR4## especially where R 1 is hydrogen.
Compounds which are particularly preferred have the formula ##STR5## More preferred formula II compounds are those wherein R 2 is hydrogen and R 1 is hydrogen or ethyl. Especially preferred formula II compounds are those wherein R 1 and R 2 are hydrogen, with the S-isomer configuration being most preferred.
Another particularly preferred compound has the formula ##STR6## especially where R 1 is hydrogen. The S-isomer of formula III is most preferred.
Especially preferred compounds are those of the formulae ##STR7##
The compounds of the present invention have physiological or chemotherapeutic uses. In most cases, the biological activities of these compounds are in large measure a consequence of their potent decarboxylase inhibiting activities. Decarboxylases are enzymes which act on α-amino acid substrates, effecting decarboxylation to produce the corresponding amine. This action is illustrated by the following equation: ##STR8##
By inhibiting this decarboxylation, the biosynthestic pathway to a number of biologically significant amines can be modulated or inhibited with physiologically useful consequences. For example α-fluoromethyl dopa inhibits dopa decarboxylase and can be used in combination with dopa to potentiate the latter's usefulness in the treatment of Parkinson's disease. α-Fluoromethyl histidine inhibits biosynthesis of histamine via decarboxylation of histidine (ED 50 in mice ˜0.4 mg/kg). Consequently, it and combinations with histamine antagonists have utilities in the prevention of gastric lesions and in treating allergic conditions. α-Fluoromethyl ornithine by virtue of its ornithine decarboxylase inhibition interrupts polyamine biosynthesis and is of utility in the treatment of some neoplasms. α-Fluoromethyl arginine is an effective antibacterial. α-Fluoromethyl glutamic acid is a CNS stimulant.
The present compounds also are substantially specific in their decarboxylase inhibition activity, that is an α-fluoromethyl-αamino acid generally inhibits the decarboxylation of the corresponding non α-fluoromethyl acid. For example, α-fluoromethyl dopa inhibits the decarboxylation of dopa; α-fluoromethyl histidine will inhibit the decarboxylation of histidine, etc.
Because of this specificity and potency as decarboxylase inhibitors, the present compounds are also useful as diagnostic tools to determine the presence and importance of the corresponding decarboxylase in relation to diseases or to the functioning of biological systems. For example, the importance of γ-amino-butyric acid in the central nervous system (CNS) may be studied by inhibiting its biosynthesis using an α-fluoro-methyl glutamic acid, etc. This diagnostic utility is aided by the potent and in many instances irreversible decarboxylase inhibiting activity of the present α-fluoromethyl amino acids.
Representative compounds have been determined to have decarboxylase inhibiting activity using conventional in-vitro assays.
α-Fluoromethyl-3,4-dihydroxyphenylalanine , α-fluoromethyl tyrosine, and α-fluoromethylmeta -tyrosine have also been found to have antihypertensive activity. This activity is determined by observing the antihypertensive effect (blood pressure reduction) on (peroral or parenteral) administration of the compounds to a spontaneously hypertensive (SH) rat. This observed effect indicates that the compounds are effective as antihypertensive agents, when conventionally administered in suitable amounts in an appropriate pharmaceutical dosage form to a hypertensive human. The pharmaceutical dosage form is conventionally prepared and generally includes conventional, pharmaceutically acceptable diluents.
The compounds of the present invention may be prepared using any convenient method.
One such useful process involves the reaction of an α-hydroxymethyl-α-amino acid with SF 4 in liquid HF, as illustrated by the following equation: ##STR9## The reaction is generally carried out at temperatures ranging from about -80° C. to about 20° C. This general reaction is also referred to as fluorodehydroxylation and is described in the Journal of Organic Chemistry 40, 3809-10 (1975). BF 3 may be used to promote the reaction.
Another method for preparation of the substituted α-fluoromethyl α-amino alkanoic acids involves the application of photofluorination. For a description of this method, see Journal of the American Chemical Society, 92, 7494 (1970) and ibid., 98, 5591 (1976). For example, α-fluoromethylglutamic acid is prepared: ##STR10## Both optical isomers of α-methylglutamic acid are known; thus this method is useful for preparation of both optical isomers of α-fluoromethylglutamic acid.
Similarly, α-fluoromethyl-ornithine is prepared by photofluorination of α-methyl-ornithine: ##STR11## Since both optical isomers of α-methylornithine are available, this method of synthesis can deliver both of the two optical isomers of α-fluoromethyl-ornithine.
α-Fluoromethyl-ornithine is a suitable starting material for synthesis of α-fluoromethyl-arginine by reaction with S-methylisothiourea: ##STR12##
An acid addition salt of a compound of the present invention may be prepared by conventional treatment of the free α-amino acid with a useful acid generally in a suitable solvent.
A single enantiomer of the present compounds may also be obtained by (1) resolving the fluorinated amino acid racemate using conventional resolution techniques or (2) resolving the precursor α-hydroxymethyl-α-amino acid using conventional resolution techniques and then fluorodehydroxylating the precursor enantiomer. A conventional resolution technique involves forming a salt of the α-amino acid with an optically active base and subsequently recovering the specific enantiomer from the salt. Compounds of the formula ##STR13## where R 2 is C 2 -C 6 alkanoyl are prepared by acylating the corresponding compound where R 2 is hydrogen. Conventional acylating agents and conditions are employed.
Compounds of the formula ##STR14## where R 1 is C 1 -C 18 alkyl are prepared by esterifying the corresponding compound where R 1 is hydrogen. Again, conventional esterification reagents and conditions are employed.
The following examples illustrate preparation of representative compounds of the present invention. All temperatures are in ° C. The fluorodehydroxylation reactions described in the examples were performed in reactors made of KEL-F®. Melting points are determined in open capillary and are uncorrected.
EXAMPLE 1
Preparation of R,S-Alpha-(Fluoromethyl)-3-Hydroxy-Tyrosine ##STR15##
One and 5/10 g of R,S, α-(hydroxymethyl)-3-hydroxytyrosine hydrochloride (α-hydroxymethyl-DOPA HCl) was dissolved in 50 ml of anhydrous hydrogen fluoride, while being cooled in a dry-ice-acetone bath. The HF solvent was then evaporated after removal of the cooling bath with a stream of nitrogen gas. This operation transforms the HCl salt into the HF salt of the starting material. (Alternatively 1.3 g of the free amino acid may be used as starting material, thus eliminating the need for the above operation.) The HF salt thus obtained is redissolved by passing into the reactor a stream of HF gas after cooling it in a dry-ice-acetone bath, until a 30 ml liquid HF was collected in the reactor. Sulfur tetrafluoride gas (1.2 ml, measured in liquid state at -78° C.) was then passed in, the dry-ice-acetone cooling bath was then removed and replaced by a cooling bath kept at -12° C. After 15 hours of aging, the solvent was evaporated with a stream of N 2 , the residue was dissolved in 50 ml of 2.5 M aqueous HCl, evaporated to dryness in vacuo and subjected to amino acid analysis on Spinco-Beckman amino acid analyzer. This analysis indicated the formation of α-fluoromethyl-3-hydroxy-tyrosine. The product R,S-alpha-fluoromethyl-3-hydroxy-tyrosine is isolated by ion-exchange chromtography in the same manner as it is described in Example 2 for S-alpha-fluoromethyl -3-hydroxy-tyrosine.
EXAMPLE 2
Preparation of S-alpha-Fluoromethyl-3-Hydroxy-Tyrosine
A. Preparation of R-α-hydroxymethyl-3-hydroxy -tyrosine
50 g of 3[3', 4'-diacetoxyphenyl]-2-acetamino -2-acetoxymethyl-propionic acid is added into 204 ml of 4 M aqueous KOH with stirring. After 1 hour of stirring (under nitrogen), the solution contains potassium salt of 3(3', 4'-dihydroxyphenyl) -2-acetamino-2-hydroxymethyl-propionic acid, formed in essentially quantitative yield. Without isolation, by methylation with dimethyl sulfate, this compound is transformed into 3(3', 4'-dimethoxyphenyl)-2-acetamino-2-hydroxymethyl-propionic acid. This operation is performed at room temperature under N 2 gas by dropwise addition with vigorous stirring of dimethyl sulfate (about 64 ml) and 4 M aqueous KOH solution (about 148 ml) over a period of about 1 hour.
The reaction mixture was stirred for another hour, then left standing overnight. Acidification (at 5°-10° C. with 55 ml of conc. aqueous HCl), extraction with ethyl acetate (12×300 ml), drying over Na 2 SO 4 and evaporation in vacuo gave R,S-3(3', 4'-dimethoxyphenyl-2-acetamino-2-hydroxymethyl-propionic acid. It was purified by recrystallization from 1325 ml of acetonitrile, m.p. 154°-6° C. (dec).
Twenty-nine and 1/10 g of strychnine was suspended in 1.12 1 of ethanol 2BA, heated to reflux, then 26.1 g of R,S-3(3', 4'-dimethoxy-phenyl) -2-acetamino-2-hydroxymethyl-propionic acid was added. The solution thus obtained was allowed to cool down and left standing overnight at room temperature. Crystals of the strychnine salt of antimer, "A" separate; m.p. 193°-194° C. ("HM").
The mother-liquor of the above named precipitation was evaporated in vacuo to dryness and recrystallized from 270 ml of ethanol 2BA; the hot solution is allowed to cool to room temperature and left standing at room temperature for ˜3 hours, then kept in the refrigerator for ˜4 hours. The crystals formed were collected on a filter and after drying, recrystallized from acetonitrile to give strychine salt of antimer "B" of 3(3'4'-dimethoxy-phenyl)-2-acetamino-2-hydroxymethyl -propionic acid m.p. 130°-132° C. (dec.). Yield 17.5 g.
Seventeen g of this strychnine salt was decomposed by dissolving it first in 160 ml of water; 31 ml of 1 M aq. NaOH solution was added. The strychnine separated was removed by filtration and the soltuion evaporated to small volume in vacuo and applied onto a small ion exchange resin column (150 ml of AG-X2 cation exchange Dowex 50 resin, 200/400 mesh). Elution with water, followed by evaporation in vacuo of the fractions which showed absorption, as indicated by an LKB UV absorption monitor (UVICORD II - 8300). This compound, antimer "B" of 3(3', 4'-dimethoxyphenyl)-2-acetamino-2--hydroxymethyl -propionic-acid showed [α] D : 78.3 +0.5° (C., 1425 in 0.1 M aq. NaOH).
Transformation of the above compound into the corresponding stereo-isomer of α-hydroxymethyl-3-hydroxytyrosine: Four and 43/100 g of antimer "B" of 3(3', 4'-dimethoxyphenyl)-2-acetamino-2-hydroxymethylpropionic acid is dissolved in 100 ml conc. HCl and sealed and heated for 90 minutes in a Fisher-porter tube immersed into an oil bath of 130° C. The solvent was evaporated in vacuo and the above HCl treatment repeated. The residue thus obtained represents R-α-hydroxymethyl-3-hydroxy tyrosine hydrochloride.
B. Fluorodehydroxylation
8 g of R-α-hydroxymethyl-3-hydroxytyrosine ·HCl is charged to a 1 l. reactor. The reactor is immersed into a dry-ice acetone bath and 80 ml of liquid HF is condensed on top of the substrate. To remove the HCl present, the cooling-bath is removed and the HF solvent removed by passing in a stream of N 2 gas. The reactor is immersed into the cooling bath again and a stream of HF gas is passed in until a liquid volume of ˜250 ml collects. 6.2 ml of SF 4 (17.6 mmol/ml: ˜109 mmol) is then bubbled in, the solution aged for ˜1 hour, the cooling bath exchanged for an ethylene-glycol bath kept at -16° C. and the solution aged for ˜22 hours. Boron trifluoride gas is passed in until saturation and the solution aged again at -16° C. for 46 hours. The cooling bath is removed and the solvent evaporated by passing through it a vigorous steam of N 2 gas. The residue is quenched in ˜100 ml of ice-cold aqueous HCl (2.5 M), evaporated in vacuo, the residue dissolved in water and added onto a column of cation-exchange resin. 2.2 1 of AG-50-X-8 resin (200/400 mesh) was employed. Elution with 0.25 M aq. HCl, containing 5% methanol; in ˜8.5 hours, 7.2 1 of this solvent is pumped through the column. This is followed by 7.2 1 of 0.4 M aq. HCl with 7.5% methanol in 8.5 hours, then concluding with 0.6 M aq. HCl with 10% methanol. 22 ml fractions are collected, 10 tubes per rack. Tubes in racks No 45-66 contained the desired compound. Evaporation in vacuo gave HCl salt of S isomer of α-fluoromethyl-3-hydroxy-tyrosine.
For liberation of the free amino acid, 4.826 g of this compound was dissolved in 90 ml of isopropanol, filtered through Celite. 6.2 ml of propylene oxide was added to the filtrate and the suspension kept at room temperature for 3.5 hours, then at ˜5° C. for another 2.5 hours. The S α-fluoromethyl-3-hydroxy-tyrosine thus formed was collected by filtration, washed with isopropanol and dried overnight in vacuo at 76° . [α] D : +9.3 O ±0.5, c, 1.82 in 1:1 mixture of trifluoracetic acid and water.
EXMPLE 3
Preparation of R-α-Fluoromethyl-3-Hydroxy-Tyrosine
For preparation of the above named compound, the strychnine salt of antimer A of 3(3', 4'-dimethoxyphenyl)-2-acetamino-2-hydroxymethyl -propionic acid (Example 2 "HM") was carried through steps analogous to those in Example 2. The final product of the sequential steps was R-α-fluoromethyl-3-hydroxy-tyrosine, with [α] D : -9° (c, 2.5 in a 1:1 mixture of H 2 O-trifluoroacetic acid).
EXAMPLE 4
R,S-α-Fluoromethyl-Tyrosine
One and 5/100 g (0.005 mol) of R,S-α-hydroxymethyl-tyrosine is charged into a reactor. The reactor is immersed into a dry-ice-acetone bath and ˜50 ml of liquid HF is collected by passing in a stream of HF gas. Under continuing cooling, SF 4 gas (4 ml, measured in liquid state at -78° C.) is passed in, then BF 3 gas until saturation at -78° C. (Stirring with magnetic stirrer). The deep-red solution thus obtained is aged overnight at -78° C.; the cooling bath is removed then, and the solvent evaporated by blowing a dry stream of nitrogen gas through it. The residue is dissolved in 20 ml of 2.5 M aq. HCl and evaporated to dryness in vacuo. The residue is dissolved in water and applied to a strong acid cation-exchange resin column, prepared with 100 ml of AG50-X-8 resin (200/400 mesh). The column is first washed with water (1.8 l), followed by 0.5 M aq. HCl. 20 ml fractions of the effluent are collected and the course of the elution is followed by UV monitor of LKB, Model UVICORD II. The fractions corresponding to the main peak in the UV curve are combined and evaporated to dryness in vacuo, to yield hydrochloride salt of R,S-fluoromethyl-tyrosine. 400 mg of this salt is dissolved in 6 ml of water; after a few minutes, crystallization of R,S-fluoromethyl-tyrosine begins. After standing overnight at 5° C., the product is filtered, washed with water, ethanol and diethylether and dried in vacuo at 76° C., to give R,S-α-fluoromethyl tyrosine.
EXAMPLE 5
R,S-α-Fluoromethyl-Histidine (FM HIST) ##STR16##
(A) Racemic N(im)Benzyl-Histidine
Thirty g of N(im)Benzyl-L-histidine is dissolved in 600 ml H 2 O and the soltuion heated in a high-pressure autoclave at 200° C. for 8 hours with shaking. The autoclave is cooled to room temperature, the clear supernatant solution evaporated in vacuo to dryness to give the R,S-α-fluoromethyl-histidine as a colorless crystal.
(B) R,S-α-Hydroxymethyl-N(im)Benzyl-Histidine (II)
Twenty g of rac. N(im)benzyl-histidine is dissolved in 1 l of hot water, then 40 g of basic cupric carbonate is added in portions and the mixture refluxed with stirring for 1 hour. The mixture is filtered while hot and the filtrate is evaporated in vacuo to give Cu chelate of racemic N(im)benzyl-histidine as a blue solid.
A mixture of 31 ml of formalin (38% H 2 CO), 3.1 ml of pyridine and 2.13 g of Na 2 CO 3 is heated with stirring to 70° C. then 20 g of the above named Cu-chelate is added and the system heated and stirred at 75° for 90 minutes. Evaporation in vacuo gives a blue solid residue. This is dissolved in a mixture of 50 ml of H 2 O with 50 ml of conc. NH 4 OH and charged onto a cation-exchange resin column (Dowex 50-X-8, 300 ml resin in the NH 4 -form) and eluted with 2 M aq. NH 4 OH solution. The effluent is monitored with LKB UVICORD II UV absorption monitor and the 1.1 l. portion of the effluent with UV absorption is combined, evaporated in vacuo to a solid. The residue is dissolved in a mixture of 60 ml of H 2 O with 5 ml of conc. aq. NH 4 OH and charged onto an anion exchange resin column (300 ml of Dowex 1-X-2 resin in the OH - form). The column is washed with water (2 l.) and eluted with 2 M aq. HCl, monitored with a UVICORD II for UV absorption. The effluent fractions with ultraviolet absorption were combined and evaporated to dryness, to give substantially pure HCl salt of N(im)benzyl-α-hydroxymethyl-histidine (II) (new compound). This compound is transformed into α-hydroxymethyl-histidine (III) in the following way: 12.5 g of II is dissolved in 200 ml of liquid NH 3 (3-neck flask, equipped with "cold-finger" condenser filled with dry-ice-acetone), then sodium is added (5.5 g, cut in small pieces) until the blue color persists for 10 minutes. NH 4 Cl is added then to consume the excess Na (indicated by decolorization) and the NH 3 solvent is allowed to evaporate under a stream of N 2 . The product III thus obtained is purified by chromatography on a cation-exchange resin column (2.2 l. of Dowex-50-X-8, 200/400 mesh). Crude III is dissolved in 100 ml of H 2 O and applied onto the resin column. The column is washed first with water (4 l.) then developed with aq. HCl (1.5 M, then 2 M). 20 ml fractions are collected, flow rate 600 ml/h.
______________________________________Fraction No. Pauly Reaction______________________________________ 1-400 1.5 M HCl -401-670 2 M HCl -671 & later +______________________________________
Fractions 671-760 are combined and evaporated in vacuo to dryness, to give III: R,S-α-hydroxymethyl-histidine.2HCl (new compound).
(C) R,S-α-Fluoromethyl-Histidine (IV)
Two and 73/100 g of R,S-αhydroxymethyl-histidine. 2 HCl(III) is dissolved in 70 ml of liq. HF, then evaporated to dryness by passing in a stream of N 2 . The residue thus obtained represents the hydrofluoride salt of c-hydroxy-methyl-histidine. It is redissolved in 200 ml of liq. HF (dry-ice-acetone cooling bath), then 9 ml SF 4 is passed in (measured as liquid at -78° C.). The solution is stored overnight, while being kept in a cooling bath of -12° C. The solution is saturated then with BF 3 gas, left standing for 5 hours, saturated again at -12° C. and left aging at the same temperature for 66 hours. The cooling-bath is then removed and the solvent evaporated by passing in a stream of N 2 . The residue represents mainly HBF 4 salt of α-fluoro-methyl-histidine. This is dissolved in 100 ml of 2.5 M aq. HCl, evaporated to dryness and transformed into the HCl salt as follows: It is redissolved in H 2 O and applied onto a cation-exchange resin column (100 ml of AG50-X-2, 200/400 mesh), eluted with H 2 O until effluent is neutral and free of F - . The product is released then from the column by 3 M aq. HCl, evaporated to dryness in vacuo, to result in a residue, consisting mainly of dihydrochloride of IV. For final purification, this is rechromatographed on another AG-50-X-2 column (900 ml resin).
______________________________________Elution with: 0.5 M aq. HCl - 1 l. 1.0 M aq. HCl - 1.5 l. 1.5 M aq. HCl - 3.3 l (collection begins here, 20-ml frac- tions) 2.0 M aq. HCl - 8.00 l.______________________________________
The desired product IV was located by Pauly test. Fractions 390-470 are combined, evaporated to dryness in vacuo, to give pure dihydrochloride of IV. Recrystallization from water-isopropanol (1:9 v/v) gives the crystalline monohydrochloride salt of α-fluoromethyl-histidine, m.p. 226°-7° (dec.).
EXAMPLE 6
Synthesis of R,S-α-Fluoromethyl-Ornithine
(A) R,S-α-Hydroxymethyl-δ-N-Benzoyl-Ornithine
Copper chelate of R,S-δ-benzoyl-ornithine (7.995 g) is added in small portions onto a mixture made of formalin (38% H 2 CO; 12.45 ml), pyridine (1.25 ml), and sodium carbonate (0.81 g) at 70° C., under mechanical stirring. After further 90 minutes stirring at 75° C., it is evaporated to dryness in vacuo, the dark blue residue dissolved in a mixture of 30 ml of H 2 O and 30 ml of conc. aq. NH 3 solution and charged to a cation-exchange resin column (130 ml of Dowex 50-X-8 in the NH 4 + form) to remove Cu 2+ . The column is eluted with 250 ml of 2 M aq. NH 3 and the effluent evaporated to dryness in vacuo. The residue is redissolved in H 2 O and applied onto an anion exchange resin column (Dowex 1-X-2, OH - form, 130 ml resin). The column is washed with H 2 O (250 ml) and eluted with 3 M aq. HCl. The HCl effluent is concentrated in vacuo to give R,S-α-Hydroxymethyl-δ-N-Benzoyl-Ornithine.
(B) R,S-α-Hydroxymethyl-Ornithine Dihydrochloride
Three and 5/10 g of the product obtained in (A) is dissolved in 40 ml of 6 M aq. HCl and refluxed for 21 hours. The solution is extracted with toluene (2×40 ml) and the aqueous phase evaporated in vacuo to dryness, to give R,S-α-hydroxymethyl-ornithine dihydrochloride (new compound).
(C) R,S-α-Fluoromethyl Ornithine
One and 1/10 g of the product obtained under (B) is placed into a reactor, the reactor immersed into a dry-ice-acetone bath and HF gas passed in until HF solution of ˜25 ml volume is formed in the reactor. The cooling bath is removed and the solvent evaporated by passing in a stream of N 2 . The residue thus obtained represents the HF salt of R,S-α-hydroxymethyl-ornithine. This residue is redissolved in HF, by cooling the reactor in the dry-ice-acetone bath and passing in HF gas until 50 ml volume is reached. SF 4 gas is passed in (4 ml as measured in liquid state at -78° C.), the dry-ice-acetone cooling bath removed and replaced by a bath kept at -15° C. After aging for 16 hours at -15° C., BF 3 gas is passed in for saturation. After 5 hours further aging, the cooling bath is removed and the solvent evaporated by passing in a stream of N 2 . The residue is dissolved in 6 M aq. HCl, evaporated to dryness in vacuo and redissolved in H 2 O (10 ml). This solution is applied onto a Dowex 50-X-8 cation-exchange resin column (400 ml resin, 200/400 mesh, H + form). The column is first washed with H 2 O (800 ml); elution with 2 M aq. HCl, 15 ml fractions are collected. Flow rate 600 ml/h. Every 5th fraction is spotted on TLC plate and developed with ninhydrin spray. Fractions No. 171-220 are combined and evaporated to dryness in vacuo, to deliver a mixture of amino acids, the main component being R,S-α-fluoromethyl-ornithine.2HCl. For further purification, this product is rechromatographed on another column, made of Dowex 50-X-8 cation exchange resin (200/400 mesh). For development, the column is first washed with water, then eluted with 1.5 aq. HCl, flow rate 0.6 l/h. 20-ml fractions are collected. The residue obtained on evaporation of fractions No. 521-540 represents pure R,S-α-fluoromethyl-ornithine dihydrochloride.
EXAMPLE 7
Synthesis of S-α-Fluoromethyl-Tyrosine
A. Preparation of The Copper Chelate of Tyrosine Methyl ether
Twentyfive g of R,S-tyrosine methyl ether (128 mmol) was dissolved in 646 ml of 0.2 N NaOH at 80° C. and this solution was added to 16.1 g of copper sulfate pentahydrate dissolved in 1600 ml of water at 80° C. An immediate precipitate was formed and the solution was allowed to cool overnight after which it was filtered affording 28.9 g of the copper chelate of R,S-tyrosine methyl ether.
B. R,S-α-Hydroxymethyl tyrosine methyl ether
Twentynine g of the copper (Cu ++ ) chelate of tyrosine methyl ether (0.064 mole) was added at 70° C. under stirring a solution of 3.9 g sodium carbonate, 52 ml of 37% aqueous formaldehyde and 5.2 ml of pyridine (nitrogen blanket). After completion of addition, there was added another 18 ml of formaldehyde solution and 1.6 ml of pyridine. After heating at 70° C. for 3.5 h and allowing the solution to cool to room temperature in an additional 1.5 h, the solution remained at room temperature overnight. In the morning, there appeared copious blue crystals which were filtered and the filtrate concentrated to dryness in vacuo. After the residue was dissolved in water and reconcentrated to dryness, it was dissolved in 90 ml of 4 N HCl. After filtration the solution was used to dissolve the above blue crystals. This required an additional 300 ml of 4 N HCl. The solution was then treated with hydrogen sulfide, filtered through a diatomaceous earth filter aid and concentrated to about 40 g of crude product. This was applied to a strong acid cation exchange resin (0.5 l of Dowex 50 X 8), eluted with 4 l of water and then 2 N aqueous ammonia. The effluent was monitored with UVICORD II (recording ultraviolet spectrophotometer) and the UV absorbing fraction was concentrated in vacuo to 22.16 g of pure R,S-α-hydroxymethyl-tyrosine methyl ether.
C. R,S-N-Acetyl-α-hydroxymethyl-Tyrosine Methyl Ether
Nineteen and 7/10 g of R,S-α-hydroxymethyl-tyrosine methyl ether (87.5 mmol) was suspended in 200 ml of dry pyridine, then 68 ml of acetic anhydride was added. After aging overnight at room temperature, the solution was concentrated in vacuo to dryness and azeotroped with 2×50 ml toluene. The residue was dissolved in 118 ml of methanol and 130 ml of aqueous 2.5 N NaOH solution and stirred at room temperature for 3.5 h. Acidification with 30 ml of conc. HCl followed by extraction (with 4×200 ml of ethyl acetate, and then drying and concentration afforded 21 g of crude product. This was recrystallized from 75 ml of acetonitrile yielding 9.35 g of R,S-N-acetyl-α-hydroxymethyl-tyrosine methyl ether, mp 151-152° C. dec.
D. Optical Resolution of R,S-N-Acetyl-α-hydroxymethyl-tyrosine methyl ether
Ten g of R,S-N-acetyl-α-hydroxymethyl-tyrosine methyl ether and 6.18 g of d-ephedrine were dissolved in 50 ml of methanol. The solution was concentrated to dryness in vacuo and then redissolved in 50 ml of warm acetonitrile. Crystallization afforded 7.34 g of the d-ephedrine salt of R-N-acetyl-α-hydroxymethyl-tyrosine methyl ether, mp 125-131° C. (Crop A). Crop A was recrystallized from 40 ml of acetonitrile affording 4.78 g of Crop B, mp 130°-134° C. The mother liquors from A and B were combined, concentrated, the residues dissolved in 22.4 ml of 2.5 N NaOH and 50 ml of H 2 O. The aqueous solutions were extracted with 2×75 ml ethyl acetate. The aqueous solutions were cooled and acidified with 5 ml of conc. HCl and the resultant solution extracted with 3×70 ml ethyl acetate. The dried organic solution was concentrated to 7.73 g (Crop C). Crop C and 4.7 g of 1-ephedrine were dissolved in 50 ml of methanol and concentrated to 12.39 g (Crop D). This was recrystallized from 50 ml acetonitrile to yield 5.06 g of the 1-ephedrine were dissolved in 50 ml of methanol and concentrated to 12.39 g (Crop D). This was recrystallized from 50 ml acetonitrile to yield 5.06 g of the 1-ephedrine salt of S-N-acetyl-α-hydroxymethyl-tyrosine methyl ether (Crop E), mp 131.5-133.5° C. dec. Crop E was recrystallized from 27 ml of acetonitrile to give Crop F, 4.72 g, mp 130.5-134.5° C. dec. Combined the mother liquors from Crop F and Crop E, and concentrated to 7.31 g of Crop G. Crop G was converted back to the free acid using the method which was used to obtain Crop C and there was obtained 3.0 g of Crop H. This was treated as was the initial R,S-material with 1.9 g of d-ephedrine. Recrystallization of the salt from 17 ml of acetonitrile afforded 2.4 g Crop J, mp 127-130° C. Crop J was recrystallized to 2.06 g of Crop K, mp 130-134° C dec.
Combined Crops B and K (6.52 g) were recrystallized from 40 ml of acetonitrile affording 6.06 g of the d-ephedrine salt of R-N-acetyl-α-hydroxymethyl-tyrosine methyl ether (75.8% overall).
The free acid was regenerated in the same manner that the combined mother liquors of Crops A and B were converted to Crop C and there was obtained 3.50 g of R-N-acetyl-α-hydroxymethyl-tyrosine methyl ether: [α] D =+92° (C, 1.35, 0.27 N NaOH).
E. R-α-Hydroxymethyl-Tyrosine
Three and 3/10 g of R-N-acetyl-α-hydroxymethyl-tyrosine methyl ether was dissolved in 100 ml of conc. HCl and heated in a pressure tube at 130° C. for 2 h. The solution was concentrated to dryness, the residue dissolved in 35 ml of H 2 O, filtered and treated with 1 ml of pyridine. 2.11 g of pure R-α-hydroxymethyl-tyrosine (81%) crystallized out: [α] D =0.86° (C, 50% aqueous trifluoroacetic acid). The circular dichroism (CD) spectrum has the same sense as the CD of S-α-methyl-tyrosine.
F. S-α-Fluoromethyl-Tyrosine
Following the procedure of example 4, S- α-fluoromethyl-tyrosine was prepared from R-α-hydroxymethyl-tyrosine.
EXAMPLE 8
(±)-α-Fluoromethylglutamic Acid
6.56 g of α-methylglutamic acid hemihydrate is photofluorinated in liquid HF solution, employing the general technique described in Journal of the American Chemical Society, 92, 7494 (1970) and 98, 5591 (1976). The substrate was dissolved in 120 ml of liquid HF and irradiated with a 2500 W ultraviolet light source under stirring while fluoroxytrifluoro-methane (CF 3 OF) gas (3.0 ml as measured in liquid form at -78° C.) was passed in the course of 80 min, under cooling in a dry-ice-acetone bath. After another 80-minute period with irradiation under similar conditions, an additional similar dose of CF 3 OF was added in 3 hours, continuing with the stirring, cooling and irradiation. The mixture was kept overnight in the dry-ice-acetone bath, then it was further fluorinated (with 3 ml of CF 3 OF, added in 5 hours with irradiation). Nitrogen gas was blown through the solution for removal of the solvent and the residue was evaporated with 2.5 N aq. HCl (2X) in vacuo. The residue was dissolved in 40 ml of water. To 10 ml of this solution 10 ml of conc. HCl was added and the mixture was refluxed for about 68 hours. After treatment with DARCO G-60, the filtrate was evaporated in vacuo and the residue refluxed with 30 ml of conc. HCl for another 68-hour period. After treatment with DARCO, the solution was evaporated to dryness, dissolved in 10 ml of conc. HCl and heated in a sealed glass tube for 24 hours in an oil-bath kept at 130-135°. Evaporation in vacuo to dryness gave a residue which was dissolved in H 2 O and subjected to elution chromatography on a cation-exchange resin column, made of 360 ml of AG50-X12 (mesh 200/400). Eluants: 2.6 l of H 2 O, followed by 0.1 N aq. HCl (1.5 l) then by 0.15 N aq. HCl. UV absorption of the effluent was monitored by a recording UV at 206 nm. 15-ml fractions of effluent were collected and 20 fractions, corresponding to the first ultraviolet absorbing peak, were combined and evaporated in vacuo to dryness, to give α-fluoromethyl-glutamic acid hydrochloride. For liberation of the amino acid, this was dissolved in isopropanol, filtered, then propylenoxide added. α-Fluoromethyl-glutamic acid 0.7 H 2 O crystallizes out of the solution. This compound is a time-dependent inhibitor of glutamic acid decarboxylase.
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Novel substituted α-fluoromethyl-α-amino alkanoic acids and esters thereof are disclosed. The novel compounds have biological activity including decarboxylase inhibition.
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CROSS-REFERENCE TO RELATED APPLICATION
The present non-provisional patent application is a continuation-in-part of application Ser. No. 13/133,405, filed Jun. 8, 2011, and entitled SURGICAL DEVICE FOR CORRECTION OF SPINAL DEFORMITIES, which is incorporated in full by reference herein. The present non-provisional patent application claims the benefit of priority of: foreign Patent Application No. GB0822507.0, which is entitled SURGICAL DEVICE FOR CORRECTION OF SPINAL DEFORMITIES and which was filed Dec. 10, 2008; foreign Patent Application No. GB0902416.7, which is entitled SURGICAL DEVICE FOR CORRECTION OF SPINAL DEFORMITIES and which was filed Feb. 16, 2009; foreign Patent Application No. GB0913457.8, which is entitled SURGICAL DEVICE FOR CORRECTION OF SPINAL DEFORMITIES and which was filed Aug. 3, 2009, all of which are incorporated in full by reference herein.
FIELD OF THE INVENTION
The present invention relates generally to a surgical device for the correction of deformities of the spinal column and finds particular, although not exclusive, utility in devices which are surgically implantable.
BACKGROUND OF THE INVENTION
At present, the surgical correction of deformities of the spinal column involves a surgical procedure for the insertion of fixation implant devices, such as pedicle screws or hooks, to each vertebra followed by application of external forces to achieve the desired correction of the shape of the spinal column and attachment of the said fixation devices to rigid rod-like elements to achieve permanent stabilisation of the involved part of the spinal column. Bone graft is also added to achieve permanent fusion of the same part of the spinal column.
Previous devices for correcting spinal deformities have involved the fixation of bone screws which connect to rods via pivoting connections, for example as described in WO-A2-2007/014119. Also, the use of ratchet mechanisms with spinal implants is known from WO-A2-2008/057861, WO 2007/143709 and EP-A2-1051947. Although these arrangements increase the versatility and ease of application of implants used for spinal fixation, the application of all currently used implants and methods for surgical correction of deformities of the spinal column results in the amount of correction of the deformity achieved during the surgical procedure often being limited. Furthermore, during application of all current implants and methods for surgical correction of deformities of the spinal column the entire correction is achieved during the surgical procedure and no further degree of correction is possible thereafter as the involved part of the spinal column is permanently fused. The consequences of this are the permanent loss of spinal motion and subsequent increase of the mechanical loads to the adjacent mobile spinal segments frequently leading to wear of these segments.
One device, described in US-A1-2005/0261770, has various arrangements of interconnecting vertebral supports including pivoting and sliding arrangements between the components in an attempt to avoid fusion and permanent loss of the mobility of the spinal column. However, such implants cannot be used as spinal deformity correcting devices as no means for adjusting the relative position of the vertebrae is provided. Other devices are described in US-A1-2006/155279, EP-A1-0667127, US-A1-2003/191470, U.S. Pat. No. 5,951,555, U.S. Pat. No. 5,672,175 and GB2412320 which include springs, flexible rods or other force-generating means, such as memory alloys, attempt to prevent development of the deformity or even to gradually correct a deformity of the spinal column. Although such disclosed devices are able to facilitate the development of corrective forces between parts of the spinal column most are passive and are unable to provide for the progressive correction of spinal deformities assisted by active movements of the human body. The present invention addresses this issue.
BRIEF SUMMARY OF THE INVENTION
In a first aspect, the invention provides a surgical device for the correction of deformities of the spinal column comprising a spinal column straightening means for permitting the relative rotation of two substantially adjacent vertebrae about a common axis substantially only in opposite rotational directions. The surgical device may be arranged such that, in use, the anterior edges of the end plates of two substantially adjacent vertebrae are substantially only permitted to move either closer to one another or further apart from one another. Correspondingly, the posterior edges of the end plates of two substantially adjacent vertebrae may be substantially only permitted to move either further apart from one another or closer to one another. The spinal column straightening means, in one embodiment, is a spinal column straightener.
The term “substantially” is used here in the phrase “substantially only permitted to move either closer to one another or further apart from one another” because it is contemplated that there may be an element of “play” in the device such that a slight degree of opposite relative movement occurs.
This device, which may be affixed to the posterior surfaces of vertebrae, therefore allows one of two modes of operation. The first is where adjacent vertebrae are permitted to increase their separation towards their front surfaces and/or reduce their separation towards their rear surfaces, thus straightening spines which are curved forwardly. The second is where adjacent vertebrae are permitted to decrease their separation towards their front surfaces and/or increase their separation towards their rear surfaces, thus straightening spines which are curved rearwardly. Furthermore, because the device substantially prevents rotation of the vertebrae in the opposite direction (of whichever mode of operation is selected) the device prevents the curved nature of the spine from worsening or returning to its former bent form after straightening. Moreover, as the individual stretches upwardly, thus temporarily straightening the spine, the device allows the adjacent vertebrae to straighten relative to one another but will prevent them from returning to the their previously curved form. Over time, an individual's curved spine may be corrected to one which more closely resembles a typical “straight” spine.
The term “substantially” is used with the phrase “only in opposite rotational directions” because it is contemplated that there may be an element of “play” in the device such that the adjacent vertebrae may rotate in the same direction. However, the amount of this common rotational movement may be minor compared to the opposite rotational movement effected due to the individual's typical daily activities.
The surgical device may include rotation means for permitting the relative rotation of the two said substantially adjacent vertebrae. This relative rotation may be about the common axis. In this regard, the common axis may be located within the spinal column and substantially outside the surgical device. The rotation means may include a ratchet means. This ratchet means may be for permitting relative rotation of two substantially adjacent vertebrae about the common axis substantially only in opposite rotational directions. The ratchet may comprise well known features such as a pawl and teeth. In at least one embodiment, the rotation means is a rotation controller. The rotation controller may include two, preferably but not exclusively, symmetrically positioned ratchet means arranged on either side of the rotation controller.
The common axis, in use, may be substantially perpendicular to the length of the spinal column. This axis may lie substantially parallel to the intersection of the coronal and transverse planes.
The surgical device may include connection means for connecting with two bone fixing elements, each element fixable, in use, to each said adjacent vertebra. In one embodiment, the connection means is connection apparatus.
The bone fixing elements may comprise substantially parallel longitudinal axes, such that, in use, the longitudinal axes are substantially parallel to the intersection of the median and transverse planes.
The common axis may, in use, be substantially perpendicular to the said longitudinal axes or intersection of the median and transverse planes.
The surgical device may further comprise rotation means for permitting, in use, the relative rotation of the two said adjacent vertebrae about an axis substantially parallel to the longitudinal axes of the bone fixing element, or intersection of the median and transverse planes.
The connection means may comprise a first male member and a first female member.
One of the two said bone fixing elements may comprise a second female member and the first male member may be connectable with this second female member.
The first male member may be rotatably and/or slidably connectable with the second female member.
The first female member may be connectable with a bone fixing element in an adjacent vertebra.
The first female member may be rotatably and/or slidably connectable with the bone fixing element.
Either or both of the first and second female members may include pivoting means for either permitting or restricting relative angular movement of any connected first male member or bone fixing element. In one embodiment, the pivoting means is a pivot controller.
The surgical device may include one or more bone fixing elements.
The surgical device may include at least one bone fixing element fixable, in use, to a first vertebra.
The surgical device may include alternative connection means for connecting with another bone fixing element fixable, in use, to a second adjacent vertebra.
The alternative connection means may comprise a first alternative female member and a first alternative male member.
The first alternative female member may be connectable with the first alternative male member of an adjacent device.
The first alternative female member may be rotatably and/or slidably connectable with the first alternative male member of the adjacent device.
The first alternative female member may include pivoting means for either permitting or restricting relative angular movement of any connected alternative male member or bone fixing element.
The first alternative female member and first alternative male member may be on opposite sides of the ratchet means.
The surgical device may include means for connecting either directly or indirectly with an adjacent similar device. When connectable directly one of the male members may be insertable into one of the female members. When connectable indirectly another intermediate element may be interposed therebetween. This intermediate element may comprise one or more male members and one or more female members, although other means of interconnection are contemplated. The intermediate element may be a rod.
Additional articulating elements may be provided within the female members shaped preferably, but not exclusively, in such a manner as to allow additional interposed articulations of the ‘ball-and-socket’ type and of the ‘sliding’ type between the articulating elements and the male and female members.
In one embodiment, the stem includes a longitudinal split along its longitudinal axis. The split may extend along the entire length or along only part of its length. The split may be arranged preferably, but not exclusively, along the sagittal plane (when installed in use). It may at least partially separate the stem into two limbs. In use the distance or separation between the two limbs may be increased temporarily and reversibly. This separation may allow the ratchet(s) to be temporarily overcome such that the angle between the stem and the bone fixing element may be set during installation. After this step the separation of the two limbs may be reduced such the influence of the ratchet(s) is again enforced over this angle.
In a second aspect, the invention provides a surgical device for correction of deformities of the spinal column comprising at least two mutually interconnectable segments arranged for affixation on at least two separate vertebrae of the spinal column, each segment comprising a first part, equipped with at least one bone fixing element adapted for affixation on at least one vertebra of the spinal column, a second part, connectable to the said first part at an axially arranged connection permitting rotation of the said first and second parts relative to each other around a first axis, the said second part also being equipped with at least one stem able to withstand mechanical loads during use, the said second part also being equipped with at least one connecting hole of design appropriate, firstly, to allow insertion of the said stem of at least one other segment of the surgical device disclosed herein to the said connecting hole and, secondly, to allow pivoting (angular movement) and axial sliding of the said stem in the said connecting hole, a ratchet arrangement of the said axially arranged connection between the said first and second parts permitting, in use, the said first and second parts to rotate relative to each other around the said first axis of rotation in a single predetermined direction but preventing the said first and second parts from rotating around the said first axis of rotation in an opposite direction, wherein, during use, at least two mutually interconnected segments of the surgical device disclosed herein are affixed on at least two separate vertebrae of the spinal column, the said stem of the said second part of the segment affixed on the vertebra above being axially inserted in the said connecting hole of the said second part of the segment affixed on the vertebra below, permitting angular movements between the said two vertebrae of the spinal column in the desired direction of correction of the deformity but preventing any angular movement between the said two vertebrae of the spinal column in the opposite to the said desired direction, and wherein, during normal daily activity or special exercise-induced movements of the human spinal column, any loads applied to the spinal column directed in a direction opposite to the said desired direction of correction of the said spinal deformity are endured, resisted and prevented by at least two mutually interconnected segments of the surgical device disclosed herein, whilst all other loads are endured solely by the spinal column protecting thus the surgical device disclosed herein from mechanical failure or loosening of its secure affixation on a vertebrae of the spinal column, and whereby, over a period of time, gradual correction of the said spinal deformity can be achieved without additional force generating means.
As described herein there is provided a surgical device for gradual correction of deformities of the spinal column without fusion of the involved part of the spinal column. The device may comprise mutually interconnected segments affixable to separate vertebrae of the spinal column. Their arrangement may comprise a ratchet as part of a pivoting connection between the part affixed to the bone and a support. The support may have a connecting opening to permit free relative rotation and axial movement, but which may restrict relative angulatory movement at least in one plane, between the mutually interconnected segments.
The configuration of the surgical device may permit gradual angular correction of the relative position of the vertebrae while at the same time all other movements, including those affected by axial loading of the spinal column are allowed. It is to be appreciated that gradual correction of a deformity of the spinal column may be achieved over a period of time following the application of the surgical device effected by active and passive movements of the spinal column during normal daily activities and exercising while, at the same time, the mobility of all parts of the spinal column may be preserved.
The bone fixing elements described and/or claimed herein may be of the pedicle screw variety.
BRIEF DESCRIPTION OF THE DRAWINGS
The above and other characteristics, features and advantages of the present invention will become apparent from the following detailed description, taken in conjunction with the accompanying drawings, which illustrate, by way of example, the principles of the invention. This description is given for the sake of example only, without limiting the scope of the invention. The reference figures quoted below refer to the attached drawings.
FIG. 1 is a perspective view of a device according to a first embodiment of the invention;
FIG. 2 is a perspective view of two of the devices of FIG. 1 in use with vertebrae;
FIG. 3 is a cross-sectional side view of a series of devices according to a second embodiment of the invention in use with a series of adjacent vertebrae;
FIG. 4 is a perspective view of a device according to a third embodiment of the invention;
FIG. 5 is a perspective view of a device according to a fourth embodiment of the invention;
FIG. 6 is a close-up perspective view of the device of FIG. 5 ;
FIG. 7 is a perspective view of two of the devices of FIG. 5 in use with two vertebrae;
FIG. 8 is a close-up perspective view of the two devices of FIG. 7 ;
FIG. 9 is a perspective view of a device according to a fifth embodiment of the invention;
FIG. 10 is a perspective view of a device according to a sixth embodiment of the invention;
FIG. 11 is a perspective view of a device according to a seventh embodiment of the invention;
FIG. 12 is a perspective view of the device of FIG. 11 with an alternative feature;
FIG. 13 is a perspective view of a device according to an eighth embodiment of the invention;
FIG. 14 is a rear elevational view of the device of FIG. 13 ;
FIG. 15 is a perspective view of a device according to an ninth embodiment of the invention; and
FIG. 16 a perspective view of a device according to a tenth embodiment of the invention.
FIG. 17 is a perspective view of a device according to an eleventh embodiment of the invention.
FIG. 18 is a partial view of a device according to a twelfth embodiment of the invention.
FIG. 19 is a perspective view of a device according to a thirteenth embodiment of the invention.
DETAILED DESCRIPTION OF THE INVENTION
The present invention will be described with respect to particular embodiments and with reference to certain drawings but the invention is not limited thereto but only by the claims. The drawings described are only schematic and are non-limiting. In the drawings, the size of some of the elements may be exaggerated and not drawn to scale for illustrative purposes. The dimensions and the relative dimensions do not correspond to actual reductions to practice of the invention.
Furthermore, the terms first, second, third and the like in the description and in the claims, are used for distinguishing between similar elements and not necessarily for describing a sequence, either temporally, spatially, in ranking or in any other manner. It is to be understood that the terms so used are interchangeable under appropriate circumstances and that the embodiments of the invention described herein are capable of operation in other sequences than described or illustrated herein.
Moreover, the terms top, bottom, over, under and the like in the description and the claims are used for descriptive purposes and not necessarily for describing relative positions. It is to be understood that the terms so used are interchangeable under appropriate circumstances and that the embodiments of the invention described herein are capable of operation in other orientations than described or illustrated herein.
It is to be noticed that the term “comprising”, used in the claims, should not be interpreted as being restricted to the means listed thereafter; it does not exclude other elements or steps. It is thus to be interpreted as specifying the presence of the stated features, integers, steps or components as referred to, but does not preclude the presence or addition of one or more other features, integers, steps or components, or groups thereof. Thus, the scope of the expression “a device comprising means A and B” should not be limited to devices consisting only of components A and B. It means that with respect to the present invention, the only relevant components of the device are A and B.
Similarly, it is to be noticed that the term “connected”, used in the description, should not be interpreted as being restricted to direct connections only. “Connected” may mean that two or more elements are either in direct physical or that two or more elements are not in direct contact with each other but yet still co-operate or interact with each other.
Reference throughout this specification to “one embodiment” or “an embodiment” means that a particular feature, structure or characteristic described in connection with the embodiment is included in at least one embodiment of the present invention. Thus, appearances of the phrases “in one embodiment” or “in an embodiment” in various places throughout this specification are not necessarily all referring to the same embodiment, but may refer to different embodiments.
Furthermore, the particular features, structures or characteristics may be combined in any suitable manner, as would be apparent to one of ordinary skill in the art from this disclosure, in one or more embodiments.
Similarly it should be appreciated that in the description of exemplary embodiments of the invention, various features of the invention are sometimes grouped together in a single embodiment, figure, or description thereof for the purpose of streamlining the disclosure and aiding in the understanding of one or more of the various inventive aspects. This method of disclosure, however, is not to be interpreted as reflecting an intention that the claimed invention requires more features than are expressly recited in each claim. Rather, as the following claims reflect, inventive aspects lie in less than all features of a single foregoing disclosed embodiment. Thus, the claims following the detailed description are hereby expressly incorporated into this detailed description, with each claim standing on its own as a separate embodiment of this invention.
Furthermore, while some embodiments described herein include some but not other features included in other embodiments, combinations of features of different embodiments are meant to be within the scope of the invention, and form different embodiments, as would be understood by those skilled in the art. For example, in the following claims, any of the claimed embodiments can be used in any combination.
In the description provided herein, numerous specific details are set forth. However, it is understood that embodiments of the invention may be practised without these specific details. In other instances, well-known methods, structures and techniques have not been shown in detail in order not to obscure an understanding of this description.
The invention will now be described by a detailed description of several embodiments of the invention. It is clear that other embodiments of the invention can be configured according to the knowledge of persons skilled in the art without departing from the true spirit or technical teaching of the invention, the invention being limited only by the terms of the appended claims.
In FIG. 1 a surgical device 10 for the correction of deformities of the spinal column includes a rotation means 11 (substantially cylindrical in shape) for allowing rotation between two elements; the two elements being a stem, or male member, 12 and a means 18 of connecting with a bone-fixing element 30 . The stem 12 is substantially cylindrical. In this embodiment, the means 18 of connecting with the bone fixing element 30 is a socket, or female member, 16 arranged on an arm radiating away from the means 11 for allowing rotation.
The rotation means 11 includes a ratchet mechanism 20 which permits the two sides of the rotation means 11 to only rotate in opposite directions relative to one another about a common axis referenced “A”. In FIG. 1 , the arrow referenced “B” indicates the direction in which the bone fixing element 30 is permitted to rotate, and the arrow referenced “C” indicates the direction in which the stem 12 is permitted to rotate. The angle between the longitudinal axis of the stem 12 and the longitudinal axis of the bone fixing element 30 is indicated “Φ”. In use, the bone fixing element 30 and the stem 12 may only rotate in opposite directions such that the angle Φ may increase but not decrease. This restriction is effected by the ratchet 20 .
The bone fixing element 30 comprises a shaft 32 having a screw thread 34 at one end and a head 36 at the other end. The head 36 is larger than the shaft 32 and of the socket 16 thus preventing the rotation means 11 from slipping off the bone fixing element 30 .
The shaft 32 of the bone fixing element 30 may rotate within the socket 16 thus allowing, in use, sideways flexing (in the coronal plane) of the spinal column. The bone fixing element 30 includes a socket, or female member, in the head 38 . This will be explained in more detail below.
FIG. 2 shows two devices 10 in use together with two adjacent vertebrae 40 , 42 . The bone fixing elements 30 have been screwed into each vertebra 40 , 42 such that each device 10 is held captive thereto by the heads 36 of the respective bone fixing elements 30 . The stem 12 of the upper device 10 has been inserted into the socket 38 of the bone fixing element 30 holding the lower device 10 captive. The stem 12 may rotate and move axially within the socket 38 thus allowing a certain amount of freedom of movement between adjacent vertebrae other than that restricted by the ratchet 20 .
The socket 38 in head 36 of the upper bone fixing element 30 may receive a stem 12 of another device 10 (not shown) attached to a vertebra above (not shown). Likewise, the stem 12 of the lowermost device 10 may be received in the socket 38 of another device 10 (not shown) attached to a vertebra below (not shown).
Because of the ability for the various elements (bone fixing shaft 32 and socket 16 ; stem 12 and socket 38 ) to move relative to one another in one or more directions and/or planes as necessary, due to an arranged tolerance in the respective male and female members, the actual vertebrae 40 , 42 do not rotate about the axis A (in FIG. 1 ).
Rather, they will rotate about the natural axes of the vertebrae, which will lie substantially in the sagittal, transverse and coronal planes.
A series 100 of devices 110 may be affixed to a series of vertebrae 40 , 42 , 44 , 46 , 48 forming a portion of a spinal column as shown in FIG. 3 . These devices 110 are slightly different to the devices 10 described above but operate in a similar manner. They each include a rotation means 111 (substantially cylindrical in shape) for allowing rotation between a bone fixing element 130 and a stem 112 . Each stem 112 is inserted into the device 110 below.
In this way the angle Φ may be increased but not substantially decreased. This means that the vertical gap “D” between the front edges of adjacent vertebrae may be increased but not substantially decreased.
A third embodiment of the device 210 is shown in FIG. 4 . It comprises a stem 212 attached to one side 214 of a rotational ratchet 220 , and a bone fixing element 230 comprising a screw thread 234 and a shaft 232 directly attached to the other side 218 of the ratchet 220 . The two sides 214 , 218 make up the rotation means 211 (which is substantially cylindrical in shape). The ratchet 220 restricts relative rotational movement of the two sides in a similar manner to that described above.
In this embodiment, a socket 238 is provided in the body of the rotation means 211 . This socket may receive a stem 212 from an adjacent device 210 , in a similar manner to that described above, such that an array of devices 210 may be interconnected. The socket 238 is arranged such that the stem 212 may rotate and move axially and angularly within it thus allowing a certain amount of freedom of movement between adjacent vertebrae other than that restricted by the ratchet 20 .
A fourth embodiment of the device 310 is shown in FIG. 5 . This device 310 is similar to the device 210 shown in FIG. 4 except that the shaft 332 of the bone fixing element 330 is not directly attached to the rotation means 311 , which is substantially cylindrical in shape. Rather, a socket 316 is provided in the body of the rotation means 311 adjacent the socket 338 for receiving the stem 312 of an adjacent device 310 . This socket 316 may receive the shaft 332 of the bone fixing element 330 . The socket 316 is arranged such that the stem 312 may rotate and move axially and angularly within it thus mallowing a certain amount of freedom of movement between adjacent vertebrae other than that restricted by the ratchet 20 . This is more clearly shown in FIG. 6 .
The axial movement is referenced “F”, the rotational movement is referenced “E”, and the angular movement is referenced “G”. All other features are the same as described with regard to FIG. 5 .
FIG. 7 shows two devices 310 arranged together, and connected or affixed to two adjacent vertebrae 40 , 42 , such that the stem 312 of the upper device 310 is inserted into the socket 238 of the lower device 310 . The arrow referenced “H” indicates the direction in which the upper vertebrae 40 may rotate relative to the axis of rotation “A”. FIG. 8 indicates the rotational “I”, axial “J” and angular “K” movement which the upper stem 312 may make relative to the lower socket 338 . There may also be some rotational movement therebetween (not shown).
A different embodiment of the device 410 is shown in FIG. 9 . This device 410 has a rotation means 411 (substantially cylindrical in shape) comprising two ratchets 420 a , 420 b separating the rotation means 411 into three portions. At each end portion of the rotation means 411 a stem 412 a , 412 b is provided projecting radially away. A socket, or female member, 416 is provided radially through the middle portion of the rotation means 411 . This socket 416 may receive a shaft 432 of a bone fixing element 430 (refer to FIG. 10 ) such that it may be affixed to vertebra. Each stem 412 a , 412 b may be connected to a bone fixing element 43 either directly or indirectly. An example is shown in FIG. 10 . The device 450 comprises a substantially cylindrical element comprising two sockets, or female members, 438 , 456 which pass radially through the cylindrical element from one side to the other. These two sockets 438 , 456 are aligned such that their respective bores are substantially perpendicular to one another. The shaft 432 of a bone fixing element is shown inserted into one of the sockets 456 . The other socket 438 may receive one of the stems 412 a , 412 b described above. Two devices 450 may be arranged one on each stem 412 a , 412 b . By virtue of ratchet 420 a the upper bone fixing element, in device 450 , and the one in the rotation means 411 may rotate relative to one another but only in opposite directions. Also, by virtue of ratchet 420 b the lower bone fixing element, in another device 450 , and the one in the rotation means 411 may rotate relative to one another but only in opposite directions.
The relative rotation of the two sets of bone fixing elements 430 may rotate around a common axis referenced “L” passing through the longitudinal central axis of the substantially cylindrical rotation means 411 .
FIG. 11 shows yet another embodiment of the device 510 . This device 510 includes a bone fixing element 530 rotatably connected to one side of a rotation means 511 . On the other side of the rotation means 511 a stem, or male member, 512 is provided. The stem 512 and bone fixing element 530 may rotate relative to one another limited by some means, possibly a ratchet means (not shown), such that they may only rotate away from each other (as shown in the Figure) so that angle Φ may be increased but not substantially decreased.
A socket, or female member, 538 is provided with the rotation means 511 for receiving a stem 512 from an adjacent device 510 as shown in FIG. 12 . The position of the socket 538 is arranged substantially on the same axis as the longitudinal length of the bone fixing element 530 . However, the longitudinal axis/direction of the bore of the socket 538 is substantially perpendicular to the longitudinal axis of the bone fixing element 530 .
This Figure, (bone fixing element 530 removed for clarity purposes) also includes a variant to the device 510 shown in FIG. 11 in that the socket 539 is a ball socket. This allows angular as well as axial and rotational movement of the stem 512 of the adjacent device 510 relative to the device 510 .
Another embodiment is shown in FIGS. 13 and 14 . This device 610 is similar to the device 510 described above, having a rotation means 611 and a bone fixing element 634 . However, the socket 638 for receiving the stem 612 of an adjacent device 610 is arranged to one side of the bone fixing element 634 as is more clearly shown in FIG. 14 . This view is from “behind” the device 610 looking along the length of the bone fixing element 634 . The socket 638 is arranged on the other side of the ratchet means 620 from the bone fixing element 634 and has its bore substantially perpendicular to the longitudinal length of the bone fixing element 634 .
A ninth embodiment is shown in FIG. 15 . This embodiment 710 comprises a bone fixing element 730 which comprises a thread 734 , a shaft 732 and a head 736 . The head includes a socket 736 for receiving the stem 712 of an adjacent device 710 . The stem 712 is attached to, or integral with one half 717 of the rotation means 711 . This rotation means permits relative rotation between the stem 712 and the bone fixing element 730 around an axis which substantially lies long the intersection of the transverse and coronal planes. The rotation means 711 comprises a body 717 at the base of which the stem 712 is connected and at the upper end of which two arms 718 , 719 are provided. The other half of the rotation means 711 comprises a body 721 on which are provided two axles or pins 715 (only one being shown) around which the two arms 718 , 719 are arranged thus allowing relative rotation of the two halves 717 , 721 .
The body 721 also includes a female socket 716 through which the shaft 732 of the bone fixing element 730 is arranged allowing relative rotational movement between the bone fixing element 730 and the stem 712 about the longitudinal axis of the bone fixing element 730 .
The rotation means 711 includes a ratchet 720 which in this case comprises a set of teeth on one of the two halves 717 , 721 and a pawl on the other of the two halves. It is possible that the pawl is another set of teeth, the sets of teeth arranged and provided to allow them to slide over one another in one direction but prevent them sliding over one another in the other direction.
FIG. 16 shows an embodiment 810 which is similar to the ninth embodiment described in conjunction with FIG. 15 . The only difference is that device 810 includes a means for attaching another transverse stem 813 to the head 836 of the bone fixing element 830 . Alternatively, the transverse stem may be integral with the head 836 .
Another bone fixing element 830 is provided in the same vertebra 40 and arranged laterally to one side of the other. The transverse stem 813 connects the heads 836 of the two bone fixing elements 830 . In this way greater stability is provided to the structure and to the spinal column. It should be understood that the concept of an additional bone fixing element 830 and interconnection between the two bone fixing elements 830 in the same vertebra may be applied to any of the other embodiments described herein.
In the foregoing description of the various embodiments, it has been explained how the angle Φ may increase but not decrease. It is to be understood that the opposite effect is also possible, namely that the angle Φ may decrease but not increase. This restriction may be effected by appropriate arrangement of the ratchet as required.
Although when describing the various sockets, or female members, 38 , 238 , 316 , 338 , 416 , 456 , 438 , 538 , 539 , 638 it has been explained that they are arranged to allow relative rotational, axial and angular movement with the stem or shaft it should be understood that in some embodiments it may be desirable to limit or even restrict some or all of this allowance. It is possible to include means, such as contoured surfaces, for permitting only relative movement between the stem, and/or shaft, and socket in one or more directions (axial, rotational, angular) and/or planes (sagittal, coronal, transverse).
For instance it may be preferred to restrict relative angulatory movement in one or more planes such as the sagittal plane.
Any of the embodiments described herein may include a ball joint in any of the female sockets.
Furthermore, although not all of the bone fixing elements 30 , 330 , 430 are shown including a head of greater size than the socket through which they may be inserted it is to be understood that they may include such a head to prevent them from disengaging with their corresponding devices and/or rotation means.
An eleventh embodiment of the invention is shown in FIG. 17 . This device 910 is similar to the device 10 shown in FIG. 1 insofar as the device 910 includes a rotation means 911 allowing rotation between two elements; the two elements being a stem, or male member, 912 and a means 918 of connecting with a bone-fixing element 930 . The stem 912 is bifurcated at one end into two arms 913 between which the means 918 for connecting with a bone fixing element (also known as the bone fixing element root holder), is held. However, in this embodiment, the rotation means 911 includes a curved ratchet mechanism 920 which permits the two elements 912 and 918 of the rotation means 911 to only rotate in opposite directions relative to one another about a common axis referenced “A” which lies substantially outside the device 910 and preferably, but not exclusively, anterior to the device 910 . It will be appreciated by those skilled in the art that the arrangement of placing the common axis of rotation “A” anterior to the device 910 approximates the common axis of rotation “A” to the natural axis of rotation of the vertebrae of the spine and significantly facilitates the rotational function of the device 910 . Axis “A” may lie substantially parallel to the intersection of the transverse and coronal planes.
The term “curved” is used to describe that the ratchet teeth may be arranged in an arc, being a portion of a circle, subtending an angle of between 5 and 90 degrees.
In this embodiment, one set of teeth of the ratchet 920 is positioned on the outer surface of the bone fixing element root holder 918 , and the other set is positioned on the inside surface of one of the arms 913 . It is possible (but not shown in FIG. 17 ) that another ratchet is provided between the other arm 913 and the other side of the bone fixing element root holder 918 .
FIG. 18 shows a portion of a device 1010 according to a twelfth embodiment of the invention. This device 1010 includes a bone fixing element 1030 similar to the bone fixing element 30 shown in FIG. 1 and a socket, or female member, 1038 similar to the socket, or female member, 38 in the bone fixing element 30 shown in FIG. 1 . The stem 1012 , similar to the stem 12 shown in FIG. 1 , is not shown for the sake of clarity. Connection between two adjacent devices is provided by inserting the stem 1012 of an adjacent device (shown only partially here for clarity) into the socket, or female member, 1038 in a manner similar to the manner illustrated in FIG. 2 .
In this embodiment an articulating element 1057 is provided within the socket, or female member, 1038 of the bone fixing element 1030 . The articulating element 1057 is arranged preferably, but not exclusively, between the anterior edge of the stem 1012 and the internal surface of the socket, or female member, 1038 and shaped preferably, but not exclusively, in a such manner as to allow ‘ball-and-socket’ type rotational articulation between 1058 the anterior surface of the articulating element 1057 and the internal surface of the socket, or female member, 1038 and ‘sliding’ type articulation 1059 between the posterior surface of the articulating element 1057 and the anterior surface of the stem 1012 . It will be appreciated by those skilled in the art that the arrangement of providing an articulating element 1057 within the socket, or female member, 1038 of the bone fixing element 1030 allows angular as well as axial and rotational movement of the stem 1012 within the socket, or female member, 1038 of the bone fixing element 1030 and, at the same time, reduces significantly the development of contact stresses on the contact surfaces during use.
A thirteenth embodiment of the invention is shown in FIG. 19 . This device 1110 is similar to the device 10 shown in FIG. 1 insofar as the device 1110 includes a rotation means 1111 allowing rotation between two elements; the two elements being a stem, or male member, 1112 and a means 1118 of connecting with a bone-fixing element 1130 (otherwise known as a bone fixing element root holder). However, in this embodiment the rotation means 1111 includes two separate and preferably, but not exclusively, symmetrically positioned ratchet mechanisms 1120 a and 1120 b which permit the two elements 1112 and 1118 of the rotation means 1111 to only rotate in opposite directions relative to one another about a common axis.
The male member 1112 bifurcates into two arms 1113 at its upper end between which the rotation means 1111 is located.
In this embodiment, the stem 1112 includes a longitudinal split 1160 provided through its longitudinal length. In this Figure the split 1160 is shown extending from the male member's upper end, at a point where the two arms 1113 commence, almost all the way to the distal and lowest end. It is to be understood that different devices may be provided with different length splits, as required. The two sides of the longitudinal split 1160 are shown approximately parallel to the sagittal plane. Other orientations are contemplated. It will be appreciated by those skilled in the art that the arrangement of the longitudinal split 1160 through the stem 1112 allows, in use, the two arms 1113 to be moved apart and away from one another in the directions indicated by the arrows referenced 1161 a and 1162 b . With the two arms 1113 moved in this manner the two sets of teeth in each ratchet 1120 a , 1120 b will become disengaged such that the bone fixing element 1130 may be rotated relative to the male member 1112 . When the desired angle therebetween has been reached, the two arms 1113 may be moved back towards together (in direction opposite to those referenced 1162 a 1162 b . In this regard, the material composition of the male member 1112 may be selected to provide a degree of resilience such that the two arms 1113 are maintained in relatively close relationship (such that the ratchet teeth are engaged) without any force being imparted thereon. The arms 1113 may spring back to this position after being held temporarily apart.
In one embodiment, the split may extend from one end to the other of the male member 1112 and connecting means for releasably retaining the two male member halves together may be provided. For instance, a clip, spring, bungee or other such connecting means may be employed.
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The present invention relates generally to a surgical device for the correction of deformities of the spinal column and finds particular, although not exclusive, utility in devices which are surgically implantable. Presently known implantable surgical devices are unable to provide for the progressive correction of spinal deformities assisted by active movements of the human body without fusion of the involved part of the spinal column. The present surgical device comprises a spinal column straightening means for permitting the relative rotation of two substantially adjacent vertebrae about a common axis substantially only in opposite rotational directions.
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BACKGROUND OF THE INVENTION
This invention relates generally to epicyclic power transmissions, and more particularly to such power transmissions wherein gear means are eccentrically mounted and journalled for gyration about a common axis and connected to a torque arm or plate to prevent rotation, yet permit torque transmission, through appropriate means, such as chain to an output shaft.
U.S. Pat. Nos. 3,726,158 and 3,013,447 each describe eccentric Torque Transmissions, utilizing eccentric motion, but neither teach nor suggest the eccentric mounting of a plurality of gear means for gyrating motion, with the throws being equally spaced for efficient operation.
SUMMARY OF THE INVENTION
According to the present invention an improved epicyclic power transmission is provided. The transmission includes a torque plate or torque arm, and an input shaft journalled for rotation. A plurality of gears are eccentrically mounted on the input shaft, and are interconnected to each other and to the torque arm to prevent rotation of the gears but permit gyration of the gears about a common axis and to translate the gyration to an increased torque output.
DESCRIPTION OF THE DRAWINGS
FIG. 1 is a longitudinal sectional view of one embodiment of a power transmission according to this invention:
FIG. 2 is a perspective exploded view of the gears of FIG. 1;
FIG. 3 is a detail view of a portion of FIG. 1 showing the interconnection of the gears;
FIG. 4 is a detail view similar to FIG. 3 of another embodiment of the driving interconnection of the gears;
FIG. 5 is a detail view of yet another embodiment of a driving interconnection of the gears;
FIG. 6 is a detail view of a slightly modified form of the driving connection of FIG. 3;
FIG. 7 is a detail view of still another embodiment of a driving interconnection of the gears;
FIG. 8 is a longitudinal sectional view of yet another embodiment of this invention;
FIG. 9 is a sectional view taken substantially along the plane designated by line 9--9 of FIG. 8;
FIG. 10 is a longitudinal sectional view of a two chain embodiment of this invention; and
FIG. 11 is an exploded perspective view of the gears of FIG. 10.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring now to the drawings, and for the present to FIGS. 1, 2 and 3, one embodiment of a power transmission according to the present invention is shown. The transmission includes a housing 10, having a torque plate or torque arm 12 secured to one end thereof by bolts, one of which is shown at 13. An input shaft 14 extends through the torque plate 12 into the housing 10, and is journalled in the plate 12 by bearing 16, and sealed by seal 18.
The input shaft 14 is provided with a pair of axially spaced eccentrics 20 and 22 on which are journalled a pair of gears 24 and 26 respectively by a pair of bearings 28 and 30 respectively. The eccentrics 20 and 22 have their throws spaced by about 180°; i.e. they are essentially equally spaced on the input shaft 14.
The torque plate 12 is provided with six circumferentially spaced cylindrical recesses, two of which are shown at 32, and which are equally spaced from each other.
The gear 24 is provided with six circumferentially spaced pins 34 mounted thereon and extending therethrough. Bushings 36 are provided on one end of each of pins 34 and extend with pins 34 into the recesses 32, and bear against the cylindrical side walls of the recesses. The diameter of each of the recesses 32 is larger than the diameter of the bushings 36.
The gear 26 is also provided with six circumferentially equally spaced pins 38, which are axially offset with respect to the pins 34. The pins extend on both sides of the gear 26. Six annular rings 40 are provided and are arranged to journal, on their interior surfaces, the ends of pins 34 and 38 which are adjacent to each other on their respective gears 24 and 26.
Extending from within the housing 10 is an output shaft 42 which is journalled on the end of the input shaft 14 by bearing 44 and on the housing 10 by bearings 46. An output gear 48 is rigidly secured to the shaft 42.
A three stand chain 50 circumferentially engages the teeth of the gears 24, 26 and 48 to provide a driving interconnection therebetween.
In operation, a rotary input of the input shaft 14 is translated into a gyratory motion of the gears 24 and 26 with respect to the centerline of the shaft 14 by action of the pins 34, 38, the rings 40, bushing 36 and recesses 32. This motion will cause the gears 24 and 26 to drive the chain 50 at a reduced speed and increased torque. The chain 50 also being connected to the output gear 48, which is concentric with the centerline of the output shaft 42, will rotatably drive the output shaft 42 at the increased power, decreased speed from the input shaft.
FIGS. 4 through 11 show other embodiments of the invention.
FIG. 4 shows an embodiment where unitary crank arms 54 interconnect the gears 24 and 26. This eliminates the need for separate pins and interconnecting rings. The remainder is the same including bushings 36 which ride in recesses (not shown).
In FIG. 5 the six circumferentially spaced pins are provided in two sets of pin assemblies, each having three or more pins. In one of the sets each assembly includes a pin 60 secured to torque plate 12a and surrounded by a bushing 62. The bushing 62 rides in a circular opening 64 in gear 24a. In the other set an enlarged pin 66 is secured to the torque plate 12a, passes through one of the openings 64 and has a reduced end 68 surrounded by a bushing 70, the bushing 70 riding in circular opening 72 in the gear 26a. This arrangement provides the same type of gyratory movement as the arrangement in FIGS. 1 through 3 and FIG. 4.
FIGS. 6 and 7 show other embodiments of the pin assemblies. The device of FIG. 6 is similar to FIGS. 1 through 3 except that pins 34a and 38a are shorter than pins 34 and 38 and have some overlap. In the embodiment of FIG. 7 three separate pins 74, 76, and 78 are utilized, affixed to the torque plate 12, gears 24 and 26 respectively. Rings 80 connect pins 74 and 76, and rings 82 interconnect pins 76 and 78. This also will produce a gyratory motion of gears 24 and 26.
FIGS. 8 and 9 show yet another embodiment of the power transmission. In this embodiment gear 24 has six pins 84 threadably engaged and circumferentially arranged. One end of each pin mounts a bushing 86 disposed in one of the recesses 32. The other end of the pin extends through opening 88 in gear 26 and is surrounded by bushing 90 co-acting against the inner surface of opening 88. This configuration also produces a gyrating motion.
FIGS. 10 and 11 show another embodiment which utilizes a double chain configuration. In this embodiment the housing 100 journals shaft 102 for rotation in end plate 103 on bearing 104. In this case the shaft has a first pair of eccentrics 106 and 108 with opposite throws; i.e. spaced 180°. A first pair of gears 110 and 112 are journalled on the eccentrics by bearings 114 and 116 respectively. The shaft 102 also has a second pair of eccentrics 118 and 120 on which are journalled gears 122 and 124 respectively by bearings 126 and 128 respectively. A first set of three or more equally circumferentially spaced pins, bushings or fillets 130 are threaded into gear 122, pass through openings 132 and are secured to gear 110 by nuts 133. Similarly a second set of three equally circumferentially spaced pins 134 are threaded into gear 124, pass through openings 136, and are secured to gear 112 by nuts 137.
A torque plate 138 is rigidly secured to the end plate 103, and an output gear 140 is rigidly secured to output shaft 142 which, in turn, is journalled by bearings 144 and 146 respectively on the input shaft 102 and housing 100. A first strand of triple chain 148 connects gears 110, 112 and torque plate 138. A second strand of triple chain 150 connects gears 122, 124 and output gear 140.
In this embodiment pins 130 cause gears 110 and 122 to act as a unit and pins 134 cause gears 112 and 124 to act as a unit. Each of these two gear units, acting under the action of the eccentric and guided by openings 132 and 136, gyrate both with respect to each other and the centerlines of the shafts 102 and 142 to cause a torque to be transmitted to the output shaft 142 responsive to rotation of the input shaft 102.
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An improved epicyclic power transmission is disclosed. An input shaft is journalled on a torque plate. Gears are mounted on eccentrics on the input shaft. Chain connects the gears to the torque plate to prevent rotation of the gears but permit gyration of the gears. The chain also connects the gears to an output shaft whereby the gyratory motion of the gears is translated to rotation of the output shaft on an increased torque and reduced speed.
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CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application claims priority of U.S. provisional application serial No. 60/293,040 entitled “Quick Rail System”, filed May 23, 2001, such application being incorporated herein by reference.
FIELD OF THE INVENTION
[0002] This invention relates generally to railings, and, more particularly to modular systems suitable for commercial and private railings and balustrades.
BACKGROUND OF THE INVENTION
[0003] Metal railing systems, but more especially stainless steel railing systems, presently on the market usually require components to be welded together to form the required shapes and frames. This can only be achieved in a workshop environment, and is very time consuming due to the required polishing of the welded seams. On modular metal systems, which do exist, the connections are either complicated, unsuitable for consumer installation or unsightly, making most of these systems only suitable for factory or some commercial installations.
[0004] In addition, the requirements of many building authorities for vertical spacing of spindles or similar components in balusters to prevent small children from falling through the gaps, makes the use of existing stainless components prohibitively expensive, as those systems are labor intensive and/or require many fittings.
[0005] It is therefore an object of this invention to improve the ease of installation and construction of railings for decks, balconies, marine docks, tennis courts, and other applications, which require a barrier for safety, esthetics or a separation.
[0006] It is a further object of this invention to offer the lowest possible number of components with which to cover virtually all variations encountered in the above applications, and to provide components in such a way, that the installation can be done by moderately skilled consumers with very simple tools, or by professional contractors in far shorter installation times than is possible presently. A special feature of the system is the possibility to use either vertical spindles or balusters, or to use virtually any horizontal cable or wire system on the market today, as determined by the architect, and/or in accordance with any relevant building regulations.
[0007] It is a further object of this invention to offer maximum corrosion resistance and an essentially maintenance free railing system, yet be price competitive with other materials, which do not offer these advantages, through the use of innovative design and manufacturing of the individual components.
SUMMARY OF THE INVENTION
[0008] The objects set forth above as well as further and other objects and advantages of the present invention are achieved by the embodiments of the invention described herein below.
[0009] The invention is based on commercially available stainless steel (or other material) tubing, which is connected into a railing, or into a framework by especially designed fittings, which allow all possible standard rail configuration. The common item to all such fittings is a special dovetail connector, which accepts all fittings, and which is easy to attach to the tubing, yet provides a safe and largely tamperproof connection.
[0010] The outer framework of the tubing is very similar for virtually all applications, whether the inside consists of commercially available horizontal wire or cable systems, or uses the spindles in a baluster system, which is part of this invention, except that the lower tubing may be omitted for the horizontal cables.
[0011] Whereas most installations require vertical tubing or “uprights” to be mounted on a horizontal surface, it is sometimes desirable to attach uprights to a vertical surface, and therefore the system has been designed for both possibilities.
[0012] It is also a common requirement for steps to lead from or to the railing, and for these steps to either be in line or at right angles (either left or right) to the railing. All four possibilities are covered in this invention, as are all possible angles of such steps either up or down, using the identical fitting.
[0013] Also common to the system is, that all connections may be held together by mechanical connections, instead of welded connections. The connections may further be held together by a commercially available epoxy, yet the system only relies on the epoxy to prevent rattles or vibration, and will stay together safely through the mechanical connections even if the epoxy fails, has been badly applied, or is not there.
[0014] For a better understanding of the present invention, together with other and further objects thereof, reference is made to the accompanying drawings and detailed description and its scope will be pointed out in the appended claims.
BRIEF DESCRIPTION OF THE DRAWINGS
[0015] [0015]FIG. 1 a is a pictorial view of a mounting base of this invention;
[0016] [0016]FIG. 1 b is a bottom view of the mounting base of this invention;
[0017] [0017]FIG. 2 a is an exploded pictorial view of a base bracket for mounting on a vertical surface;
[0018] [0018]FIG. 2 b is a pictorial side view of the base bracket mounted on a vertical surface;
[0019] [0019]FIG. 3 a is a partial cross-sectional view of a dovetail connector of this invention with a connecting screw;
[0020] [0020]FIG. 3 b is an exploded view of the dovetail connector of this invention shown with a connecting screw extending therefrom;
[0021] [0021]FIG. 4 a is a pictorial view of a straight version of a rail connector of this invention;
[0022] [0022]FIG. 4 b is a pictorial view of a left version of a rail connector of this invention;
[0023] [0023]FIG. 4 c is a cross-sectional view of a right version of a rail connector of this invention;
[0024] [0024]FIG. 4 d is a pictorial view of a right version of a rail connector of this invention;
[0025] [0025]FIG. 5 a is a pictorial view of a straight version of an adjustable rail connector of this invention;
[0026] [0026]FIG. 5 b is a pictorial view of a left version of an adjustable rail connector of this invention;
[0027] [0027]FIG. 5 c is a pictorial view of a right version of an adjustable rail connector of this invention;
[0028] [0028]FIG. 5 d is a pictorial view of a male rail adaptor of this invention;
[0029] [0029]FIG. 6 a is a pictorial view of one embodiment of a post cap used with a railing system of this invention;
[0030] [0030]FIG. 6 b is a pictorial view of a second embodiments of a post cap used with a railing system of this invention;
[0031] [0031]FIG. 7 is a side view of a railing system of this invention with spindles in a balustrade;
[0032] [0032]FIG. 8 is a side view of a railing system of this invention using commercially available wire rope systems; and
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0033] The railing system of the present invention comprises a plurality of vertical tubes or posts, one or more horizontal rails extending between adjacent posts, and a modular connecting means for connecting the vertical posts to the horizontal rails. Posts are installed on either a vertical or horizontal surface through a mounting base, either alone or in combination with a base bracket.
[0034] [0034]FIGS. 1 a and 1 b show an illustration of the mounting base 10 used for all posts or uprights. The base 10 features a spigot 12 , which fits snugly inside a standard tube (not shown). The base may also have recessed holes 16 for attachment to a surface or other railing system component by bolts or screws. The base 10 is preferably symmetrical, and can therefore be turned 180 degrees, which is of benefit since it reduces the amount of prefabricated base assemblies which need to be offered for use with the present invention. An upright standard tube or post can be fitted on site to the spigot 12 of the base 10 using an epoxy, or could be supplied with the base 10 as a welded and polished assembly having the correct height, thus saving on installation time. It is also possible to use the base 10 for a horizontally oriented tubular component, such as when connecting a horizontal rail component to a pre-existing wall.
[0035] [0035]FIG. 2 a is an illustration of a base bracket 14 for use in vertical mounting in the mounting base 10 of the present invention. The base bracket 14 is used when the railing needs to be mounted on a vertical surface 15 , such as shown in FIG. 2 b , inwards and over the top of the surface 15 . The top flange 17 of the base bracket 14 is shaped in such a way as to accept the mounting base 10 and to provide a strong support against side loading from any direction. In FIG. 2 a , the top flange 17 is shown with an aperture of the same size as the spigot 12 of the base 10 . However, in an alternate embodiment (not shown), the top flange 17 may also be a solid layer of material. If recessed holes 16 are used in the base 17 , the top flange 17 may also have recessed holes 16 to receive screws or bolts for attachment. The recessed holes 16 in the base 10 can be provided with screws 18 of a suitable size to allow the mounting base 10 to be connected to the top flange 17 of the base bracket 14 . Attached to the top flange 17 at a right angle is a side flange 19 capable of being attached to a vertical surface 15 , as shown in FIG. 2 b , through bolts, screws or other means, such as adhesives, known in the art depending upon the material of that surface.
[0036] In another embodiment of the base bracket 14 , the base bracket 14 is manufactured reversed. That is, the base 14 will be a mirror image of the embodiment shown in FIG. 2 a , which will allow the post to be mounted away from the vertical surface 15 as opposed to inwards over the vertical surface 15 . The same features and requirements of the base bracket 14 discussed above will apply.
[0037] [0037]FIGS. 3 a and 3 b illustrate of a dovetail connector fitting 20 for use with the present invention. This fitting is the common mechanism used to fix all other connective fitting components to the posts, with the exception of the base 10 and bracket 14 , and serves to connect any vertical tube to any horizontal tube. The dovetail connector 20 has several unique features.
[0038] The backside 22 of the dovetail connector 20 is shaped to a radius, which allows a perfect fit to the outside of a standard tube and is attached to the post. In a preferred embodiment, the dovetail connector back 22 has a short stub or spigot 24 and the standard tube or post has an aperture capable of receiving the stub or spigot which is used for initial location on the tube, and which greatly increases the shear strength vertically and horizontally when the system is in use. A commercially available glue or epoxy may also be used to secure the backside 22 of the dovetail connector to the post.
[0039] The dovetail connector underside 26 is shaped to perfectly complete the circular crosssection of any of the fitting components used in conjunction with the dovetail connector 20 . This is aesthetically pleasing and offers no sharp corners or edges, as the connecting screw 28 is also recessed into that curved surface. The dovetail connector top 30 has a hole 32 , which lines up with the recessed hole 34 in the underside 26 . A suitable screw 28 , which is commercially available but might have to be modified in length, is inserted into an aperture 34 on the underside 26 of the dovetail connector, passes through an aperture 32 in the top edge 30 , which provides a perfect alignment, and finally enters a threaded hole inside each of the fitting components used in conjunction with the dovetail connector 20 . When the screw 28 is tightened, the dovetail connector 20 and the matching fitting component are tightly connected and complement each other similar to a simple puzzle.
[0040] To facilitate alignment of the connecting screw 28 during assembly, and to prevent such screw from getting lost, it is preferable to fit a commercially available rubber “O” ring 36 of suitable size over the screw 28 in such a way, that the end of the screw is flush with the top edge 30 of the dovetail connector 20 . This screw 28 is therefore “pre-loaded” for final assembly.
[0041] In one preferred embodiment, the dovetail connector 20 has a center opening 38 to allow small electric wires and the like to pass from the horizontal tubes into the vertical tubes, thus allowing LED lights to be installed. In yet another embodiment, the dovetail connector 20 has a recessed hole 40 which can be used to permanently fasten the dovetail connector 20 to the upright tube, either by welding, or by sheet-metal screw, or by a suitable rivet.
[0042] [0042]FIGS. 4 a - d show illustrations of a rail connector fitting used in conjunction with the dovetail connector 20 described above. A straight rail connector 40 , shown in FIG. 4 a , allows rails to be in line, i.e. 180 degrees with respect to each other, with a possibility of 5 degrees variation either way, if required. The left rail connector 42 , shown in FIG. 4 b , and right rail connector 44 , shown in FIG. 4 d , are identical to the straight rail connector, except the left connector 42 and right connector 44 each have a shortened wing 46 with respect to wing 48 , which allows them to be placed next to each on the post such that the sides having the shortened wing 46 are adjacent thus forming any 90 degree to 170 degree angle with respect to each other. Angles from 60 degrees to 90 degrees can be achieved by using the same left and right but the shortened wing 46 will have to be trimmed back by grinding it to suit the desired angle.
[0043] Referring also to FIG. 4 c , there are several features common to all three fittings. The wings 46 and 48 are designed in such a way as to fit perfectly around the outside of a given tube, and to blend the horizontal tube into the vertical tube. Apart from being aesthetically very pleasing, as there are no sharp edges or corners, the wings 46 and 48 serve to further take significant side loads against the railing, such as those being experienced when a heavy person falls against it. In combination with the short stub 24 on the dovetail connector 20 , which takes the smaller vertical load, and also contributes to horizontal loads, the rail system can take very significant side (horizontal) loads, which are essentially being limited only by the choice of tubing used.
[0044] The rail connector underside 50 is open and designed in such a way as to accept the dovetail connector 20 inside where it becomes hidden like a simple puzzle, except for the small exposed underside of it, which complements and closes the opening perfectly. An opening 41 on the end of the rail connector opposite the wings 46 and 48 is shaped to receive the end of a rail component.
[0045] Preferably, the rail connector internally threaded hole 52 near the top is designed to accept the end of the connecting screw 28 “pre-loaded” into the dovetail connector 20 .
[0046] [0046]FIGS. 5 a - 5 c show illustrations of the stair rail connectors which have been designed in three versions, a straight stair rail connector 56 , a left adjustable rail connector 54 and right adjustable rail connector 58 . The adjustable rail connectors are used to connect railings for up or down stairs to a standard railing. Each stair rail connector 54 , 56 and 58 is identical to the rail connectors 40 , 42 and 44 described above and shown in FIGS. 4 a - 4 d , except that end 41 of is replaced by a conventional knuckle joint 59 in the stair rail connectors 54 , 56 and 58 . Thus, the left adjustable rail connector 56 and right adjustable rail connector 58 each have a shortened wing, which allows them to be placed next to each other on a post such that the shortened wings are adjacent, just as a left rail connector 42 and right rail connector 44 may be placed next to each other. Further, a left rail connector 42 or right rail connector 44 may be placed next to a right stair rail connector 58 or left stair rail connector 54 , respectively, by locating the sides of the connectors having a shortened wing adjacent to each other. In addition to all the features embodied in the standard rail connectors the three fittings have additional common features.
[0047] [0047]FIG. 5 d shows an adjustable male rail adaptor 60 that fits into the knuckle joint 59 of the stair rail connectors 54 , 56 and 58 . A suitable connecting screw is used which is commercially available. This arrangement allows the stair rail to be positioned at an angle within a vertical plane with respect to a post, and thus the same fitting can be used for a handrail for a stairway to either go up or done.
[0048] All possible standard uses of a connected stair handrail are covered such as a straight in-line connection, a left and right connection, and all of those either going up or down. A commercially available recessed screw fixes the up or down angle once selected.
[0049] [0049]FIGS. 6 a and 6 b show two embodiments of post caps 62 for use with the present invention to close the top of the vertical tube. Those skilled in the art will recognize that several varieties of caps may be used in the railing system, thus allowing for different appearances at a low cost. For example, the embodiment shown in FIG. 6 a , the post cap 62 has a flat top surface, while in the embodiment shown in FIG. 6 b , the post cap 62 has a domed crown.
[0050] Referring also to FIG. 7, the post caps 62 will be fitted onto the top of a rail post or tube 78 . Preferably, a commercially available glue or epoxy is added, which has the simple function of preventing a possible loss of the cap 62 . If the railing system 70 is fitted with LED lights 64 , the small size electric wires from each horizontal section can be reached and connected if the cap 62 is removed, and subsequent access for maintenance or replacement is possible.
[0051] [0051]FIG. 7 shows an illustration of an embodiment of the railing system 70 of this invention with the tubular components being vertical spindles in a baluster type arrangement. Depending on the building code, a maximum distance between each spindle 72 may be predetermined which governs the spacing between the tubes. At the desired spacing, holes that match the outside diameter of the spindles 72 are drilled into the underside of the top horizontal rail 74 and the top side of the lower horizontal rail 76 .
[0052] The spindles 72 consist of identical pieces of straight rod, which has a slight chamfer at each end to allow easier inserting into the holes. The length of each spindle 72 is identical, and is determined by the desired distance between the top rail 74 and bottom rail 76 . A section is assembled on the floor by simply inserting the spindles 72 into the holes of the bottom rail 76 and the top rail 74 . The length of the spindles 72 determines the total height of the baluster, since they touch the inside of the horizontal rails at the lowest and the highest points. The completed section is held together temporarily by tape, rubber “bungee cord” or similar, and then slotted into the four dovetail connectors 20 attached to the rail post 78 from the top and pushed down. Once the four hidden screws have been tightened, there is no possible movement by the spindles 72 as they are captured and held tight by the top rail 74 and bottom rail 76 .
[0053] [0053]FIG. 8 represents a rail system 70 using horizontal wire rope 80 strands or similar commercially available cable systems which pass through each upright tube or rail post 78 at the desired height. Each horizontal wire rope 80 is attached to the end posts 82 and is tightened. The resulting horizontal pulling force obtained by the tensioning acts to compress the horizontal tubes and thus further strengthens the completed rail system 70 . The rail system 70 of this invention may be used with many possible attachments and is not limited to the examples described herein. In one embodiment, as shown in FIG. 8, LED Lights 75 are attached to the railing. Wiring for such LED lights is threaded through the rails and posts to make the railing more aesthetically pleasing.
[0054] Although the invention has been described with respect to various embodiments, it should be realized this invention is also capable of a wide variety of further and other embodiments.
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A modular railing system is disclosed which is based on commercially available tubing, which is connected into a railing by especially designed fittings, which connect to each other and the rails and posts of the railing system to allow all possible standard rail configuration. All connections are thereby held together by mechanical connections, instead of welded connections.
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BACKGROUND OF THE INVENTION
This application pertains to the art of video control circuitry and more particularly to diagnostic scanners incorporating a video output display. The invention is particularly applicable to ultrasonic diagnostic scanners operating in the B scan mode, i.e., examining a planar region of a patient. Although the invention will be described with particular reference to ultrasonic scanning equipment, it will be appreciated that the invention has other applications such as controlling displays from computerized tomographic scanners and other diagnostic equipment which produce video displays and to broader applications incorporating video control circuitry generally.
Video display devices for diagnostic equipment commonly consist of a patient scanning means for scanning the patient and determining diagnostic values corresponding to small incremental subregions of the patient. Diagnostic values, such as accoustic reflectivity or radiation absorption, are derived by the scanner for each subregion. The diagnostic values derived from each pass of the scanner are stored at a plurality of addresses in a memory--each address corresponding to one subregion. Commonly, scanners make a plurality of passes deriving a plurality of diagnostic values for each of many subregions. The plurality of diagnostic values derived for each subregion are generally summed, averaged or compared for substitution with diagnostic values at each memory address.
After sufficient passes, the diagnostic values at each address are used to create a video display. The position in the display is determined by and corresponds to the position of the subregion in the patient. Mathematical analysis of the values, such as convolutions, Fourier transformations, least-squares analysis, and others, may be employed to adjust the stored diagnostic values to improve the quality of the display. The grey tone at each position in the display is related to the magnitude of the diagnostic value at each address.
A standard video display has about 480 parallel scan lines. In a black and white video monitor, each scan line can be cut into most any number of display positions, commonly, called "pixels". For convenience, each scan line has been commonly cut into 512 pixels. This, in turn, requires 262,144 memory addresses which are commonly gained by using a 512×512 memory--a readily purchased electronic commodity.
The display by the nature of video monitors, being a planar rectangular grid of pixels, the subregions of the patient selected are generally chosen to be a planar, rectangular grid of subregions. The rectangular grid is again 512 subregions square.
Oftentimes, a medical diagnostician finds that only a small part of a planar region scanned is of medical interest. Accordingly, the value to the diagnostician of the video display is improved if the smaller region of interest is enlarged for easier viewing. Because the controls for conventional video monitors in diagnostic equipment are generally digital controls, the image commonly can be enlarged only by powers of 2. That is, a diagnostician can view the entire planar region; a quarter of the planar region; an eighth of the planar region, etc.
Conventionally, the controls for video displays for diagnostic scanners use read zoom implementations to enlarge the display size. A read zoom enlarges the display by displaying only a fraction of the diagnostic values stored in the memory but displaying each one a plurality of times. For example, if only a half the memory elements in the X direction and half memory elements in the Y direction are to be displayed the 512×512 memory has effectively been reduced to a 256×256 memory. However, the 256×256 memory is still displayed on a 512×512 pixel video display. Thus, each memory element generates four pixels of video display. Even interpolating the diagnostic values in adjacent memory elements only partially improves the picture. Further, enlargements such as eight or sixteen times form a very coarse display. Further, although the display is enlarged, the resolution is not improved because the same data is displayed only larger.
In ultrasonic diagnostic scanners the subregions which diagnostic value represent, is determined with a system such as that shown in the article by Joseph H. Holmes, William Wright, Edward P. Meyer, G. J. Posakony and Douglass H. Howry entitled "Ultrasonic Contact Scanner for Diagnostic Application", The American Journal of Medical Electronics, Vol. 4, No. 4 pp 147-152 October-December, 1965. In such a system, an ultrasonic transducer is moved across the surface of the patient with a rocking motion to view a planar region therebeneath. As the transducer is moved, it transmits ultrasonic accoustic pulses and receives echoes from tissue interfaces in the body. The strength of an echo is an indication of the accoustic reflectivity of a subregion. The position of the subregion is easily determined geometrically from the position of the transducer, the angular orientation of the transducer, and the length of time from transmission of an ultrasonic pulse to the receipt of each echo. The subregions, position of the transducer and angular orientation of the transducer are commonly referenced in terms of an x,y coordinate system. Conventionally, the processing equipment for deriving appropriate address of the memory for each subregion from the position and orientation of the transducer treats the x position, y position, slope of x, and slope of y values each as independent variables. This is a relatively large number of variables to be processed and requires a large amount of processing circuitry.
Traditionally, in ultrasonic scanners the video monitor is oriented so that the scan of the electron beam is vertical. This entails orienting the video display tube 90° rotated from most other video displays. This is done perhaps because the ultrasonic pulses are transmitted through the body often in a vertical direction or at an angle with respect to the vertical. Further the 512×512 memory produces a roughly square display or 1×1 aspect ratio allowing the top of the screen to be used for displaying textual material such as the patient's name, the date, the scale and other diagnostic information. However, a cross section of the human body is not generally square. Rather, for patients resting on their backs, the cross section is wider than it is high. Thus, the roughly square display is often awkard for displaying planar regions of the human patient.
SUMMARY OF THE INVENTION
The present invention contemplates a new and improved video display control which overcomes all of the above referenced problems and others and provides an easier to use, economical to produce control which improves resolution of the display. In accordance with the present invention, there is provided a video display control which includes a continuously variable analog write zoom. This allows the affected sizes of the subregions of the planar region under examination to be reduced as the display is zoomed to an enlarged scale. In accordance with a more limited aspect of the invention, the memory is modified and the display modified and reoriented to produce a 4×3 aspect ratio which matches the aspect ratio of the human torso.
In accordance with a still more limited aspect of the invention, the coordinate position determining electronics is reduced by handling the x position, y position, x slope and y slope as a pair of independent and a pair of dependent variables rather than four independent variables.
A principal advantage of the invention is improvement of video display images for medical diagnostic purposes. Another advantage of the invention is the simplification and increased versility of the write zoom electronics.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention may take physical form in certain parts and arrangements of parts of preferred embodiment of which will be described in detail in this specification and illustrated in the accompanying drawings which form a part hereof.
FIG. 1 illustrates a system diagram of a diagnostic scanner in accordance with the present invention;
FIG. 2 is a block diagram of the analog processor module of FIG. 1;
FIG. 3 is a block diagram of the B-mode buffer of FIG. 1;
FIGS. 4A and 4B are a block diagram of the accumulator of FIG. 1;
FIGS. 5A and 5B are a block diagram of the memory control of FIG. 1;
FIG. 6 is a block diagram of the memory of FIG. 1;
FIG. 7 is a block diagram of the video port of FIG. 1; and
FIG. 8 is a block diagram of a box generator.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring now to the drawings wherein the showings are for the purposes of illustrating the preferred embodiment of the invention only and not for purposes of limiting the invention. FIG. 1 shows a block diagram of an ultrasonic scanning device including a video display. The system includes a sonographic scanning system 10 which includes the ultrasonic transducer, transducer position and orientation resolving system and a front control panel for the system.
The scanning system produces diagnostic data as a series of diagnostic values; coordinate position data from which the coordinates of the subregion producing each diagnostic value can be derived, and control signals for controlling the mode and manner of transforming the position and diagnostic data into a video display.
In the preferred embodiment the scanner is an ultrasonic scanner. The diagnostic values are the accoustic reflectivity of the subregions. Other scanners which produce different types of diagnostic values may, of course, also be used. Included in the coordinate position data are the coordinate position of transducer, the slope of the transducer, the time of ultrasonic transmission and the time of echo receipt. The control functions include a box positioning control for positioning a box around a next region of interest in a display. A write zoom control causes the next scan of the transducer to produce an enlarged display only of the boxed region or other smaller region. Numerous other control functions are enumerated and alluded to below.
Diagnostic data, position data, transmit and echo timing signals and control signals are conveyed from the sonographic scanning system 10 to an analog processor 12. The analog processor digitizes the analog diagnostic values at a rate of about 8 Mhz.
Further, the analog processor scales the position data in accord with a field-of-view control signal from scanning system 10. It should be appreciated that as the video display is enlarged, the subregions in the planar region examined become smaller. Accordingly, as the ultrasonic pulse traverses the patient, it crosses subregion boundaries more rapidly. The analog processor determines the subregion coordinates for the scale selected corresponding to each digitized diagnostic value and converts the subregion coordinates from analog-to-digital. This digital signal, the digital offset position information or DOPI, is in the preferred embodiment a 14-bit signal. Further, the analog processor provides timing signals MA0, MA1 and MCLK indicating the initial position and slope signals to an accumulator 16.
The digital diagnostic values are conveyed from analog processor 12 to a buffer 14 for temporary storage in a fast memory before being transferred to a slower main memory.
The digital offset position information DOPI are applied to buffer 14. The buffer adjusts these signals to shift the coordinate system describing the subregions, so that the coordinates of the selected group of subregions corresponds with the coordinates displayed by the video display. This transformation produces positionally offset position information, POPI.
The timing signals from the analog processor are conveyed to an accumulator 16. From the timing signals the accumulator generates change in x coordinate signals Δx, change in y coordinate signals Δy, and write data gate signals WDG which are sent to the buffer to show the corresponding positionally offset position information for respective diagnostic values. In response to the Δx, Δy and WDG signals the buffer returns add x count XADDCT signals and add y count YADDCT signals to an address clock in the accumulator. In response to the address clock, the accumulator generates in conjunction with a memory control 18 the actual memory address IAX and IAY each diagnostic value.
The memory control 18 in response to control signals from the control panel provides timing and priority control over memory functions, provides video sync and timing functions, and accesses a main memory 20 for read out.
The main memory 20 stores the diagnostic values for each subregion at a corresponding address and reads out the stored diagnostic values for each pixel of the display.
A video port 22 performs final processing of digital video signals and converts the digital signals to analog for display in a video monitor screen. The final processing includes superimposing of alpha numeric characters or the zoom box on the video display and changing and inverting the grey scale ranges.
A Microprocessor 26 is connected with the memory control and video port to enable the system to produce more sophisticated refinements in manipulation of the data whereby more meaningful diagnostic display can be obtained.
The analog processor, shown in FIG. 2, includes a video conversion means 102 for converting analog diagnostic data into a digital representation and a position conversion means 104 for scaling the analog position data and converting it into a digital representation. The position conversion means 104 includes means 110 for receiving data indicative of the x slope, y slope, x position and y position. Also included in the position conversion means is a means 112 for translating the subregion within the planar region of the patient which corresponds to the center of the video display. Means 112 enables the displayed area to be translated across the planar region of the patient until a specific region of interest is centered within the display. Further, the position converter means include a field-of-view decoder means 114 for adjusting the scale of the display. In the preferred embodiment, the field-of-view decoder enables the operator to select among six preselected scales, specifically scales in which the distance from the top to the bottom of the video display is equivalent to 5, 10, 20, 30, 40 or 50 centimeters.
In addition to the field-of-view scaler means 114, which enables the operator to select among preselected discrete scales, is a means 116 for continuously adjusting the scale. Means 116 enables an operator to zoom in on a small region of interest in the planar region displayed to enlarge and clarify it. Regardless of which of the six preselected field-of-view scales are in use the continuous adjustment means can enlarge the scale.
The 5 centimeter scale has a resolution on the order of a tenth of a millimeter. Presently the quality of transducers and other physical limitations of ultrasonic scanning systems make a tenth millimeter an outside limit on resolution. Depending on numerous factors, such as the type of tissue in the region of the patient examined, the frequency of the ultrasonic pulses, etc. around a tenth millimeter of resolution, noise seriously degrades the displayed images. The preferred embodiment limits resolution to a tenth millimeter to accomodate currently available transducers. It is appreciated that the limits on the enlargement controls may be selected greater or lesser than a tenth millimeter resolution.
The position conversion means 104 also includes a box shaper means 118, which in conjunction with means 116 for continuously adjusting the scale, is used to cause a character generator to generate a rectangular outline on the video screen indicating the region which will be examined, if a scan is made with the current zoom setting.
The position conversion means 104 also function to convert the position signals from an analog to a digital format. This conversion is done with an analog-to-digital conversion means 120 which converts the position signals as modified for the translations in the center of the display, for discrete scale adjustments and for continuous scale adjustments from an analog to a digital representation.
Further, the converter includes a timing means 112 which performs a clocking function. In ultrasonic diagnostic scanners, the timing means is triggered by the transmission of an ultrasonic pulse to start a series of clock pulses. Each time an echo is received the time elapsed, i.e. number of clock pulses since the ultrasonic transmission is noted. The elapsed time indicates a distance between the transducer and the subregion which produced the echo. These timing pulses include the MA0, MA1 and MCLK pulses sent to the accumulator 16 and pulses for scaling by the position conversion means 104 for use in deriving the digital offset position information.
Looking now to the details of the position conversion means 104, to operate the scanner the technician first selects a field-of-view or scale of the display, i.e. the size of the area of the planar region of the examined patient to be displayed. This selection is made from the front control panel of scanning system 10 which produces a field-of-view control signal FOV. There are six, in the preferred embodiment, field-of-view lines--one for each discretely selectable scale--connecting the control panel with an encoder 140 in the field-of-view decoding means 114. This encoder transforms signals received on each of the six inputs into a unique 3-bit address designating the selected scale. This 3-bit address is used in performing several scaling functions within the position conversion means 104. For scaling the x and y position and slope signals according to the field-of-view selected, the three bit address of the field-of-view decoder means selects a corresponding multiplication factor. The selection is made from among six multiplication factors, one corresponding to each of the selectable field-of-view scales. This selecting is carried out by an addressable multiplication factor selection means 142 consisting of six voltages forming the multiplication factors and an addressable multiplexer 146 for choosing the voltage corresponding to the selected scale. To generate the six scaling voltages, a reference voltage is applied to an attenuator 144 consisting of a ladder network of resistors which attenuates the reference voltage in several steps to produce six scaling voltages. In response to a receipt of the 3-bit address from encoder means 140, multiplexer 146 selects the attenuated voltage which corresponds to the 3-bit address. The selected multiplication factor is conveyed from multiplexer 146 to a multiplying means 148. The multiplying means multiplies the scaling voltage by a zoom factor from continuous scale adjusting means 116 or by unity if means 116 for continuously adjusting the scale has not been activated. This modification of the multiplication factor will be discussed below. The multiplication factor as modified in multiplication means 148 is conveyed to a multiplying means 150 which multiplies the x and y slope and position signals by the appropriate multiplication factor. In the preferred embodiment, the multiplication means 150 is so connected and the scaling voltages so chosen that the multiplication means 150 multiplies the x and y slope and position signals by the scaling factor to adjust the size and coordinate positions of the subregions. The field-of-view adjusted x and y position and slope analog signals are connected to analog digital conversion means 120.
Means 110 for receiving the x and y slope and position is connected to a multiplexer 152. Multiplexer 152 is clocked by MA0 and MA1 timing signals from timing means 122 to serialize these four types of data and feed them singly to multiplication means 150.
Means 116 for continuously adjusting the scale receives an analog voltage indicative of the scale from the front control panel of the scanning system 10. This enables the scale to be continuously adjusted or zoomed. The analog voltage indicative of the continuously adjustable scaling factor is applied to an attenuator 160 consisting of a ladder network of resistors which attenuates the voltage in steps to produce five graduated output signals. These signals are appropriately scaled to intermesh with five of the field-of-view scales. Although all six field-of-view scales could be further enlarged in the preferred embodiment, the maximum scale is 5 centimeters for both the continuously adjustable scale and the discretely adjustable field-of-view scale. Thus, the 5 centimeter field-of-view scale is not able, by choice of design, to be further enlarged. This is, of course, merely by choice and a sixth output could be provided so that the 5 centimeter scale could be further enlarged. A multiplexer 162 is addressed by the 3-bit address from encoder 140 to select the appropriately scaled outputs from the ladder network 160 of the zoom factor for the field-of-view selected. The continuously adjustable scaling factor as adjusted for the selected field-of-view scale from multiplexer 162, is conveyed to a switching means 164 in the field-of-view scaler means. This switching means is controlled from the front control panel to assume one of two states depending on whether the means 116 for continuously adjusting the scale is actuated. As reference above, switching means 164 selects either a unity value or the zoom factor as one of the inputs to multiplication means 148. Thus, by operating the continuously variable zoom control, the operator affects the multiplication factor which is selected for weighting the x and y slope and position signal to adjust the subregion sizes.
The zoom factor is also connected to means 118 for shaping a rectangular box on the display corresponding to the size of the zoomed field-of-view relative to the instant display. The zoom factor chosen by multiplexer 162 forms an index for a box generator which generates a rectangular box of appropriate size on the display. A compatible box generator will be discussed in conjunction with FIG. 8 below.
Means 112 for translating the center of the display is likewise connected to the front control panel of scanning system 10. This means receives an analog voltage corresponding to the displacement in the x direction and an analog voltage corresponding to the displacement in the y direction. These two signals are connected to a switching means 170 which acts as a multiplexer to serialize the x and y offset values in time coordination with the MA1 timing signals. The x and y translation analog input signals are again applied across an attenuator 172 comprising a ladder network of resistors to produce six scaled analog translation outputs one coordinated with each of the six field-of-view scales. Again a multiplexer 174 which is addressed with the 3-bit address from the encoder 140 selects the appropriate attenuated form at the x or y translation output from among the six signals for the field-of-view scale chosen.
The selected translation output is conveyed to a means 176 for superimposing the x or y translation on the x or y position signal. This means includes a differential amplifier 178 for combining the x position signal received by means 110 with the x translation to produce a translated x position signal. Similarly, the y position and translation signals are combined in another differential amplifier 180 to produce a translated y position signal. The translated x and y position signals are connected with multiplexer 152. Multiplexer 152 receives a control input from the control panel of scanning system 10 indicating whether the translated or untranslated x and y position signals are to be serialized and conveyed to multiplying means 150.
Thus, the output of multiplier means 150 represents x and y coordinates appropriately translated and scaled for the fixed field-of-view scale and the continuously variable zoom scale. Thus, the output signals from multiplier 150 represent an appropriate scaling of the subregions so that each subregion corresponds to one display pixel in the scale chosen for viewing. In the preferred embodiment, the subregions vary from a tenth millimeter square for the 5 centimeter scale to one millimeter square for the 50 centimeter scale.
Analog-to-digital conversion means 120 includes a sample and hold means 182 which receives the output of multiplying means 150. The sample and hold means connects a storage means such as a capacitor 184 with multiplier means 150 for a sufficient duration that the capacitor becomes charged to a voltage equal to the instantaneous voltage output of multiplier means 150. With a steady state voltage on capacitor 184, the capacitor is disconnected from multiplier means 150 and connected with analog-to-digital converter means 186. The steady state voltage on capacitor 184 is converted by a fourteen bit analog-to-digital converter 186 to a 14-bit digital representation, referenced above as the digitally offset position information (DOPI) which is conveyed to buffer means 14.
Looking now in detail to the diagnostic value processing part of the analog processor and in particular the video converter means 102 for converting analog diagnostic data to a digital, representation, there is provided a video speed analog-to-digital conversion means. This conversion means receives logarithmically compressed diagnostic data from scanning system 10 and produces a series of 5-bit digital video data words at about an eight megahertz rate. Video conversion means 102 includes a sample and hold means 202 which receives analog diagnostic data. The sample and hold means connects a storage means such as capacitor 204 with scanning system 10 for a sufficient duration that the capacitor becomes charged to a voltage equal to the instantaneous voltage representing diagnostic data. After a sufficient time for capacitor 204 to reach a steady state value, it is disconnected from scanning means 10 and connected with a 2-bit analog-to-digital converter 210 for transforming the steady state analog voltage on capacitor 204 into a digital representation.
A clock means 220 controlled in part by a series of enable signals from timing means 122 clocks the video converter means 102. Clock pulses periodically cause storage means 204 to be connected and disconnected from the analog diagnostic data and synchronize the various converters and latches to be described below.
The succession of steady state voltages on the storage means 204 are each converted by 2-bit analog-to-digital converter 210 to the two most significant bits of the digital representation. The two most significant bits are stored temporarily in a latch 222.
The 2-bit analog-to-digital converter approximates the analog signal as the 2-bit binary signal. However, the 2-bit binary signal is not of the accuracy desired. In most instances there is an error between the actual analog signal and the 2-bit digital output. To further refine the digital output, this error in approximating the analog signal is a 2-bit digital output is isolated and the isolated error used in additional analog-to-digital converters to determine the less significant bits of the initial analog diagnostic data. This is achieved by using a 2-bit digital to analog converter 224 which converts the two most significant digital bits into an analog signal representing the two bits exactly. The analog diagnostic data from sample and hold means 202 is subtractively combined in a summing node 226 with the analog output from the 2-bit digital to analog converter 224 in order to isolate the analog signal corresponding to the error in approximating the analog diagnostic data as the two most significant bits.
The isolated error signal from summing node 226 is transformed by an analog-to-digital flash converter 230 to a 7-bit digital representation. In the flash converter 230, the analog error voltage is compared with seven regular incremented reference voltages to form a series of seven highs and lows which represent the number of referenced voltages which the error signal exceeds. These seven highs and lows form the 7-bit signal.
The 7-bit signal and the 2-bit most significant bits from latch 222 are stored in a 9-bit latch 232. The seven bits are coverted from a string of seven sequential highs and lows by an encoder 234 to a 3-bit binary representation. The 3-bit binary representation and the two most significant bits from latch 232 are conveyed to a 5-bit latch 236. The output of the 5-bit latch forms a 5-bit video word indicative of the diagnostic data.
In this way the video converter means converts analog diagnostic data which in ultrasonic diagnostics is generally log compressed and gain scaled into a 5-bit digital representation. In the preferred embodiment, a 5-bit digital representation is formed from the analog diagnostic data every 125 nanoseconds. The 5-bit digital representation was chosen for its ability to produce 32 grey shades on the video display. A larger or smaller number of bits can be used to increase or decrease the number of different grey scales. Of the numerous shades of grey a video monitor can produce, the average human eye can differentiate only about 20 shades.
FIG. 3 shows details of buffer 14. The 14-bit digitally offset position information from analog-to-digital converter 120 is received by an ADDER 302. The ADDER 302 combines the position information with a signal from a PROM 304. PROM 304 is addressed from the front control panel of scanning system 10 to select an appropriate position offset to be added to the position information. The position offset translates the subregion or scanner coordinate system to match the coordinate system of the video display and selects for a square 512×512 display, a rectangular 512×640 display, or a multiple image display. In the scanner coordinate system the center of the transducer field-of-view is arbitrarily assigned the 0,0 coordinate, whereas the video monitor works only in the positive quadrant, i.e. the lower left hand corner is assigned 0,0. PROM 304 supplies the appropriate offset to achieve this coordinate transformation. Further, in the preferred embodiment either a 512×512 main memory or a 512×640 main memory may be selected. The 512×640 memory produces a 512×640 array of generally square pixels forming a display with a 4×3 aspect ratio. Another feature of the preferred embodiment is a control signal, QUAD, to the PROM 304 from the front control panel changing the format of the video display from a single image to four images each in one quarter of the video display. This requires different offsets be applied to the position information. Similarly, other offset signals may be desirable in other circumstances. It may, for example, be desirable to have a six or nine image format of the video monitor. The positionally offset information is serialized by a multiplexer 306 to form positionally offset position information signals, POPI. For other modes of display such as an A scan, multiplexer 306 can be controlled to vary position signals selected and their order.
Also in buffer 14 is a means for generating a system timing signal. This includes a divider 310 which receives a horizontal drive signal from the memory control 18. Divider 310 divides this timing signal by one of a plurality of division factors. These factors vary with mode of operation. For the B mode display, a division factor 16 has been found desirable. Other division factors such as 20 for the TM mode may be used.
The buffer further includes a means for enabling the system to write on the video screen. This means includes a GATE 320. The GATE 320 produces an enable signal, BXMIT, to the accumulator to enable writing on the screen. This enable signal is in response to a valid transmit signal received from the analog processor 12 which enables the display of a B mode display. Alternately, the GATE may be operated by a transmit signal which enables the display for a TM scan. Another control for GATE 320 is an erase in progress signal, EIP, from memory control 18. This signal blanks the video screen by inhibiting the enable circuit from GATE 320 to the accumulator during an erase cycle in order to prevent interference from appearing on the screen. Other controls such as from divider 310 which may be used in the A mode display may be used to control GATE 320.
The buffer further includes a pair of buffer memories which operate simultaneously but out of sequence so that one reads data into the slow speed main memory while the other receives high speed data from the analog processor. The system is actuated in response to a signal VRAY from the accumulator 16 indicating that there is a valid ultrasonic transmission and a correct positioning of the ultrasonic transducer. Each valid ray signal indicates a new transmission of an ultrasonic pulse from the transducer and reverses the functions of the two buffer memories.
As an ultrasonic pulse travels through the planar region of a patient, it crosses subregion boundaries. At a slope between vertical and 45°, the pulse crosses subregion boundaries more rapidly in the y direction than in the x direction. Similarly, at angles between horizontal and 45° the pulse crosses subregion boundaries more rapidly in the x direction. By definition the boundary crossed most rapidly, either x or y, is chosen as the independent variable and the other the dependent variable.
From the slope or orientation of the transducer a ratio of the crossing of boundaries in the independent variable direction to the crossing of boundaries in the dependent variable direction is readily determined. In stepping through a rectangular grid, such as the display pixels, this ratio indicates the number of pixels stepped along one axis relative to the other. For example, a ratio of 2:1 indicates that after a first step is taken in the independent direction and the corresponding pixel address no step is taken in the dependent direction. When a second step in the independent direction is taken because of the 2:1 ratio, a first step is taken in the dependent direction.
Thus, it will be appreciated that for each ultrasonic pulse, the x and y coordinates of all the diagnostic values need not be known. Rather, only the independent variable, the above ratio, and changes or crossings of the pixel boundary in the independent variable direction need be known. From these three factors, all the x,y coordinates can be recreated.
The buffer memory function uses this principle to reduce the required memory capacity. The buffer memories each are addressed only by the independent variable, to address the storage location of each 5-bit digital video data word. Further, along with the five video data bits, a sixth bit is stored indicating whether the present video word represents a position a subregion displaced in the x direction from the previous data word, Δx. Similarly, a seventh bit is stored indicating whether the data word represents a position a subregion displaced in the y direction, Δy. This enables each buffer memory to be a smaller 1×1024×7 memory rather than the larger 512×640×5 main memory.
The 5-bit video data words from the analog processor 12 are received by a latch 330. Also received by latch 330 are signals from accumulator 16 indicating the crossing of a subregion boundary in the x direction, Δx, and the crossing in the y direction, Δy. Additionally, a write data gate signal, WDG, is received from accumulator 16 indicating the independent variable. The WDG signal, as will be shown in the detailed discussion of the accumulator below is the same as the one of Δx or Δy signals which is the independent variable. Latch 330 collects these signals and produces a 7-bit output for storage in the buffer memories--five bits of video data, one bit for Δx and one for Δy. The WDG signal is conveyed through latch 330 to a control means 332.
The control means 332 controls the address generators for the buffer memories and the read/write functions of the memories. Each time an ultrasonic pulse is transmitted by the transducer a valid ray signal, VRAY, is received by control means 332 from the analog processor. In response to the VRAY signal, the control means reverses the read/write functions of the buffer memories.
The two buffer memories referenced 334 and 336, each receive 7-bit signals from latch 330 for storage and either a read enable or a write enable signal from control 332. One buffer memory writes in the data produced in response to an ultrasonic pulse while the other reads out to the main memory the data produced in response to the preceding ultrasonic pulse. Because the ultrasonic transducer pulses with a periodicity on the order of a kilohertz, there is sufficient time for data to be read from a buffer memory to the main memory before the buffer memory is required to write in another ultrasonic pulse of data.
Connected between control means 332 and buffer memories 334 and 336 is a means for addressing the buffer memories. This means includes an address counter 340 for addressing buffer memory 334 and an address counter 342 for addressing buffer memory 336. Upon receiving a VRAY signal control means 332 resets the address counter for the memory in the write mode. Thereafter, upon receiving each video word, the control means 332 is clocked by clock signal, ACLK from the accumulator 16. In response to the clock signal, and WDG the control means 332 steps the address counter one step. This causes the address from the address counter to the buffer memory to change by one address, hence, changing the storage location for the 7-bit signal from latch 330.
After a memory is loaded with data from one ultrasonic pulse, control means 332 sends a memory load request signal, MLDRQ, to the memory control 18. If the main memory is ready to load, a memory load signal, MLDC, is sent to control means 332.
A multiplexer 350 receives the data read out of the one of the buffer memories which is in the read mode. The multiplexer divides the seven stored bits, conveying the five video data bits to a comparator 352 and conveying the Δx and Δy bits to control means 332. Upon receiving each Δx signal, the control means 332 produces an add one x count signal, XADDCT, conveyed to accumultor 16 for use in changing the address in the main memory to which the video data is conveyed. Similarly, the Δy signals cause control means 332 to produce an add one y count signal YADDCT, which is conveyed to accumulator 16 for use in changing the address in the main memory.
Comparator 352 receives new video data from multiplexer 350 and the video data already stored in the main memory at the corresponding main memory address from a bus transceiver 354. Comparator 352 compares these two magnitudes and returns the larger to transceiver 354 for return to the main memory. Alternately, comparator 352 may be replaced with a circuit for averaging the new video data with the already stored video data in a weighted manner.
FIGS. 4A and 4B show the accumulator 16 which receives positionally offset position information, POPI, from buffer 14 and produces the Δx, Δy and the WDG signals which the buffer uses in producing add count x and add count y signals, XADDCT and YADDCT. The XADDCT and YADDCT signals are received by accumulator 16 for use in generating addresses for the main memory 20.
The positionally offset position information signals are received by a means 402 for determining whether the x or y coordinate is going to be the independent variable and by a means 404 for determining a starting x coordinate for video data from each ultrasonic pulse and by a means 406 for determining a starting y coordinate for video data from each ultrasonic pulse.
The means 402 for determining the independent variable determines whether positionally offset position information signals for each ultrasonic pulse are changing more rapidly along the x or y coordinates and selects that coordinate for the independent variable. Changes in the dependent variable coordinate are thereafter determined from the ratio of the rate of change in the x and y directions and the changes in the independent variable.
Twelve bits of positionally offset position information signals from buffer 14 form one input to twelve exclusive OR gates 410. The other input of each EXCLUSIVE OR gate is formed by the 13th-bit of the positionally offset position information signal which is indicative of the sign. From the EXCLUSIVE OR gates 410, the outputs are sent to an adder 412 which separates the positionally offset position information into x and y components. The x component is held in a latch means 414 and the y component in a latch means 416. A comparator 418 compares the slope or rate of change of the x component from latch 414 and the slope or rate of change of the y component from latch 416 and produces an output signal indicating whether the x or y component is changing more rapidly; that is, whether x or y is the independent variable. The selected coordinate to be the independent variable is conveyed to a multiplexer 420 and forms one input thereof. The functioning of multiplexer 420 will be explained in more detail below after its other inputs have been discussed.
Positionally offset position information signals conveyed to the means 404 for determining the x starting coordinate are received by an x position register 430 and an x slope register 432. Position register 430 registers the x coordinate position of the transducer at the time of pulsing the ultrasonic transducer. A multiplexer 434 conveys the x coordinate position received to 14 bits of a 26 bit accumulator 430. Multiplexer 434 receives a select signal from a control means 438 and the sign extension from the x slope register 432. As the ultrasonic pulse traverses the patient, the x coordinate of the position within the patient determines which diagnostic values represent changes. Each time a new ultrasonic pulse is generated, BXMIT from the B mode buffer 14 causes control means 438 to load the initial values of x position from register 430 and x slope from register 432 into the accumulator 436. If the x slope value is positive, the sign extension from register 432 presented to multiplexer 434 and subsequently to the top fourteen bits of accumulator 436 will be zero. This condition will add one to the x coordinate value stored in accumulator 436 each time an x coordinate boundary is crossed. If the x slope value is negative, the sign extension from register 432 presented to multiplexer 434 and subsequently to the top fourteen bits of accumulator 436 will be one. This condition will subtract one from the x coordinate value stored in accumulator 436 each time an x coordinate boundary is crossed. As the ultrasonic pulse traverses the patient, the x coordinate of the position within the patient determines which the diagnostic values represent changes. The next x coordinate is compared by a comparator 440 with the boundaries which are displayable on the video screen. The boundaries of the displayed region are supplied by a multiplexer 442 in accordance with a selection signal from the front panel, selecting the 512×512 or the 512×640 format. If the next x coordinate is within the boundaries, an enabling signal is sent to an AND gate 444.
The 6 bits of the most significant starting x coordinate position from accumulator 436 are fed to a gating and latching means 450 which is the initial x starting address for use in producing addresses in the main memory 20. Gating and latching means 450 is enabled by AND gate 444 if both the x and y coordinates are within the display boundary. The gating and latch means 450 is connected with an up/down counter 452 which is incremented with each crossing of a pixel or subregion boundary when main memory 20 is loaded. Each crossing in the positive x direction increases the count, and in the negative x direction decreases the count. Whether the signal is traversing x in the positive or negative direction is determined by other circuitry discussed below. Each time the up/down counter 452 counts, it conveys the new count to a buffer 454 which forms a new x address, IAX, on the address bus line connected with memory 20.
The slope register 432 registers the slope or angular orientation of the transducer. The slope is expressed as a ratio of the rate of video word generation to the rate of change in the x direction. It is expressed as a fraction less than one. Accumulator 436 is clocked by control means 438 with each video word generation to add the slope fraction to the value in a reserved 12-bit section of the accumulator. The fractions are so chosen that each time an x coordinate is crossed, the sum in the accumulator crosses 1. The crossing of this sum produces an x carry signal c//x for use in generating the Δx signal.
Similarly, the positionally offset position information signals are received by a y position register 460 in a y slope register 462. Again, a y starting position is conveyed by a multiplexer 464 to 14 reserved bits of the 26-bit digital accumulator 466. Multiplexer 464 receives a select signal from control means 468 and sign extension from the y slope register 462. As in the x accumulator, the initial y position and y slope values are loaded in accumulator 466 by control means 468 upon receipt of BXMIT from the B mode buffer 14. A control means 468, actuated by a clock from the analog processor 12, again controls multiplexer 464 and accumulator 466 so that a rate multiplier is again formed in which each time the sum of the fractional parts crosses 1, a y carry signal c//y is produced. The next y position from the 14-bit position signal in accumulator 466 is fed to comparator 470 which compares position signal with boundary signal from a multiplexer 472 to determine whether or not the present subregion of the patient is within the display area. If the next y position is within the display region, AND gate 444 receives an enable signal. If the next subregion is within both the x and y boundaries, AND gate 444 receives two enable signals and, in turn, enables gating and latch means 450 and 480. This coincidence gated with BXMIT produces the signal VRAY.
The six bits of the starting y address are conveyed to gating and latch means 480 which again is enabled only when both the x and y addresses are within the viewing area of the monitor. The y addresses received by gating and latch means 480 within the display area are conveyed to an up/down counter 482 which counts up each time the y address changes by the equivalent of one pixel in the positive direction and down each time the y address changes by one pixel in the negative direction when main memory 20 is being loaded. The count from counter 482 is fed to a buffer 484 and conveyed to the address bus for generating addresses IAY, into main memory 20.
Whether x and y addresses to main memory 20 are increasing or decreasing is determined for up/down counters 452 and 482 from the x sign signal, from the x slope register 432, from the y sign signal, from the y slope register 462 and from the add x count and add y count signals from buffer 14. The x sign signal forms one input to a first flip-flop 490 and the y sign signal forms one input to a second flip-flop 492. Both flip-flops also receive clocking pulses. The Q output of flip-flop 490 and the add y count signal from buffer 14 form the inputs to a NAND gate 494, the output of which forms the decrease x signal to counter 452. Similarly, the NOT Q output of flip-flop 490 and the add x count from buffer 14 form the inputs of another NAND gate 496, the output of which forms the increase x signal. Similarly, the Q and NOT Q outputs of flip-flop 492 each form one input, respectively, of NAND gates 498 and 500 while the add y count and the add x count signals form the other inputs, respectively. The outputs of NAND gates 498 and 500 form the decrease and increase y signals, respectively, for counter 482.
The x sign signal from slope register 432 and the x carry signal from accumulator 436 each form an input to an EXCLUSIVE OR gate 510. Similarly, the y sign and y carry signal each form the input to another EXCLUSIVE OR gate 512. When the slope is positive, a carry signal will occur only when a pixel boundary is crossed. However, when the slope is negative, a carry signal is produced by the accumulator with every pulse except when a pixel boundary is crossed. Accordingly, the EXCLUSIVE OR gates 510 and 512 are used to transform these two opposite, but equivalent, indications of the crossing of a pixel boundary into a uniform indication of the boundary crossing. These pixel boundary crossing signals x and y form inputs into multiplexer 420 along with the independent variable signal from comparator 418. As explained above, the independent variable is either Δx or Δy, whichever comparator 418 determines to be changing most rapidly. These three signals are conveyed to a latch 520 which is clocked to produce the above discussed write data gate, WDG, signal, the Δx signal and the Δy signal for buffer 14.
As the system is designed, the independent variable changes more rapidly than the dependent variable. If this expectation is not met, errors may occur. When the orientation of the transducer is very close to 45°, round off errors in accumulators 436 and 466 in producing the carry x and carry y signal may, from time to time, cause a dependent variable to appear to vary more rapidly than the independent variable. To preclude the dependent variable from appearing to change more rapidly than the independent variable, a dependent variable control means 530 is provided. This means allows only one pixel boundary crossing signal in the dependent variable direction to be generated for each pixel boundary crossing signal in the independent variable direction. If a second or additional apparent boundary crossing signal in dependent variable direction occurs, the additional signal is stored until such time that two crossing signals in the independent variable direction occur without intervening crossing signal in the dependent variable direction. At that time, the stored crossing signal in the dependent variable direction will be inserted to preserve the appropriate ratio of independent-to-dependent variable direction, crossing signals.
Means 530 includes a NAND gate 532 which receives a delayed clock pulse on one input and pixel boundary crossing signals in independent variable direction on the other input for presetting a flip-flop 534. The delayed clock pulse is generated by a clock 536, such as an eight megahertz oscillator, which is connected indirectly to a delay line 540. The output of the delay 540 forms the delayed clock input to NAND gate 532. The boundary crossing signals in the dependent direction and the delayed clock pulse from delay 540 form the inputs of an AND gate 542. Coincidence of the clock and a dependent variable boundary crossing signal causes an output pulse from AND gate 542 to a NOR gate 544. Each time there is no coincidence on the inputs of NOR gate 544, it will enable an up/down counter 546 to count up one count. Each time a dependent variable boundary crossing signal is produced by multiplexer 420, counter 546 counts up one count. Each time an independent variable boundary crossing signal is produced, flip-flop 534 produces an output which is returned to an input of multiplexer 420 to indicate an independent variable boundary crossing signal has been sent to latch 520 and to form one input to an AND gate 550. Other inputs to AND gate 550 include an enable signal from the up/down counter which is produced in response to each up count and an enable signal from a NOR gate 552 whose input again comes from the up/down counter 546. The output of NOR gate 552 indicates that a dependent variable boundary crossing signal has been conveyed to an input of multipliexer 420 from counter 546. In this manner, each time a dependent variable boundary crossing signal is conveyed from multiplexer 420, AND gate 542 and OR gate 544 cause counter 546 to count up one count. And each time an independent variable crossing signal is conveyed from multiplexer 420, flip-flop 534 with AND gate 550 and OR gate 544 causes counter 546 to count back down one count. Upon counting down one count, an output signal is produced indicative of the temporarily stored dependent variable boundary crossing, which indication is conveyed to the input of multiplexer 420. Accordingly, if two dependent variables crossing signals are conveyed before a second independent variable boundary crossing signal is conveyed, up/down counter 546 will count up two numbers. Then, upon the next occurrence of an independent variable boundary crossing signal, the up/down counter will count down one number transferring a dependent variable boundary crossing indication to multiplexer 420. As long as the ratio of independent-to-dependent variable boundary crossing signals remains, one-to-one counter 546 counts up and down between 1 and 2. However, when an independent variable boundary crossing signal is conveyed, not followed by a dependent variable boundary crossing signal, the stored count in up/down counter 546 at that time will be counted out of counter 546 and into multiplexer 420. Also connected to up/down counter 546 is an input 554 connected to the analog processor to receive a load signal each time an ultrasonic beam is transmitted from the transducer into the patient. This load signal zeroes counter 546.
Shown in FIGS. 5A and 5B are details of memory control means 18. Memory control includes a means 600 for producing memory timing signals. This means includes an oscillator 602, such as a delay line oscillator, with a cycle time on the order of 500 to 600 nanoseconds. Timing signals from the oscillator are conveyed to a memory timing means 604 which shapes and modifies timing signals to produce a plurality of timing signals for main memory means 20.
Also included in the memory control is a priority encoder 610 which receives a series of request signals for special display formats, such as display control, refresh, erase, computer port, and memory load. Priority encoder 610 produces an encoded output to a latch 612 which is gated by a timing signal from memory timing means 604. Latch 612 temporarily stores the encoded signal for reading by a decoder 614. Decoder 614 is cycled by memory timing means 604 to produce display control, refresh, erase, computer port, and memory load control signals. Connected to decoder 614 to receive the control signals are display control means 620, refresh means 622, erase means 624, computer port means 626, and memory load means 628. In response to the control signal, each of these means generates the appropriate sequence of addresses onto the address bus. Further, each of these means, upon completing their sequence of addresses, produces a request signal for the corresponding function which is returned to reset the priority encoder 610.
Memory control means 18 includes a display control means 620 for generating the addresses and control signals for main memory 20 to read out the stored diagnostic data to the video port. Display control means 620 generates signals serial data buffer load (SDB load), serial data load (SD load), and serial data clock (SD clock) which act on a special portion of main memory 20, described later to allow serialized video data words to be applied to the video port 22. The signal video is also generated which gates the serialized video data to the video port 22.
Included in memory control means 18 is a circuit means 622 which provides refresh addresses to main memory 20. This insures that data stored in main memory 20 is not destroyed.
Memory control means 18 includes a means 624 for generating erase addresses and write signals to write zeros into main memory 20 to erase previously stored ultrasound data.
Memory control means 18 includes a computer port means 626 which gives the microprocessor access to the main memory 20 for retrieving and/or altering data stored in main memory 20. The microprocessor accesses the main memory through an address and control decoder means 640, and a data bus transceiver 672. By proper selection of control codes an x address counter/register 646 and a y address counter/register 660 are accessed to set up a unique x,y coordinate in main memory 20. The addresses set up in registers 646 and 660 may be read back into the microcomputer through a multiplexor 670 and data bus transceiver 672. The microprocessor may also access a control register 642 through means 640 and 672 to set up the control modes for an x and a y counter/registers 646 and 660. The microprocessor can read or write specific data points from main memory 20 through transceiver 672 and a video data bus transducer 674. When proper codes are set up in control register 642, each time a data point in read or written by the microcomputer the x or y address will increment after the read or write operation.
A memory load means 628 is also included. The actual circuitry is located on the B mode buffer 14. This means allows the buffer memories to be loaded into main memory 20 through bus transceiver 354 located on the buffer 14. Each memory load cycle MLDC will advance the buffer being read out by one address. Internal codes in the buffer memories 334, 336 tell control means 332 that main memory 20 is loaded and no more memory load cycles are generated.
Another part of the control is a TV or video monitor control means including an oscillator 680 on the order of 24 1/2 megahertz. The frequency produced by oscillator 680 is divided by a divider 682 to produce clock pulses for controlling memory means 20. These clock pulses are used for synchronizing the read-out of video data from the memory 20 with the sweep and scan timing of the video monitor. A second divider 684, again, reduces frequency of oscillator 680 to produce a timing signal for controlling a TV sync generator 686. The TV sync generator produces a series of video control signals including composite sync, composite blanking, horizontal drive, vertical drive, odd field, and even field video control signals.
Details of main memory means 20 are shown in FIG. 6. The heart of the memory means is a memory array 700 which, in the preferred embodiment, is a 512×640×5 RAM memory. This enables the memory to store five bits of diagnostic data corresponding to an array of 512×640 subregions or pixels. Other memory sizes, of course, may be used.
The five bits of diagnostic data are received from the video data bus by a bus transceiver 702. Bus transceiver 702 conveys the five bits of video data to the memory array 700 in time with a clock pulse to coordinate with the appropriate main memory address signals.
Diagnostic data stored in the memory array 700 is addressed out to a multiplexer 704. Multiplexer 704 returns stored diagnostic data to bus transceiver 702. Thus, bus transceiver 702 receives the new diagnostic data from the video data bus and corresponding data already stored in memory array 700. In response to a control signal, transceiver 702 selects one or the other of the values to become the stored data in the memory array at each address.
The stored data read from memory array 700 is also conveyed to an octal D latch 710. Data signals are gated through latch 710 by appropriate gating signals into a shift register 712. Shift register 712 also receives appropriate load and clocking signals to resest the shift register and the clock data therethrough to serialize the video data for display.
The y main memory addresses, IAY, from address bus driver 662 and a part of the x main memory address from address bus driver 650 in memory control means 18 are conveyed to a multiplexer 720 in main memory means 20. Multiplexer 720 multiplexes these address signals to generate partially the addresses within the memory array 700 to which the diagnostic data from the data bus is being conveyed. Multiplexer 720 is clocked to synchronize the address with the corresponding diagnostic data. A buffer 722 receives the clock pulses from the memory timing means 604 of the memory control means for clocking memory 700 to coordinate the flow of data.
The remaining x main memory addresses are generated within main memory means 20. The remaining x address signals from the x address bus driver 650 of the memory control means are received by a latch 730. Latch 730 produces enable signals for multiplexer 704 and bus transceiver 702. Additionally, it provides one input to AND gate 732, which receives an x address signal as a second input. The output of NAND gate 732 provides an enable signal to octal D latch 710 and to a buffer 734. Buffer 734 recieves an 8-bit write signal to produce a 16-bit write enable signal for use in conjunction with addressing memory array 700.
Video port 22 is shown in greater detail in FIG. 7. When main memory means 20 is in the read mode, diagnostic data stored in the individual 5-bit memory elements of memory array 700 is fed serially through shift register 712 to a multiplexer 802 of the video port. Multiplexer 802 also may receive calibration and test video signals. The data selected by multiplexer 802 for viewing is conveyed to an ADDER 810. ADDER 810 adds a digital offset signal received from an analog-to-digital converter 812 to the serial data for the purpose of shifting the position of display of the video gray scale information on the video screen. The analog-to-digital converter 812 receives an analog signal from the position potentiometer on the front control panel.
In addition to the gray scale position discussed above, the system include a gray scale window control. The window potentiometer controls an analog-to-digital converter 814, the output of which is applied to a window interpolator 820. This interpolator adjusts the number of gray shades displayed. The number of shades are adjustable continuously from 1 to 32.
Video data from window interpolator 820 is conveyed to a PROM 822 where they may be adjusted by a transfer function. The adjusted video data are conveyed to a multiplexer 824 which superimposes on the video data other video signals such as from a character generator, a box generator, a grid generator, a caliper generator, etc. Also, the multiplexing order of multiplexer 824 can be controlled to invert the video image.
The video data from multiplexer 824 are conveyed to a latch 830 which is gated by a gate means 832 in response to composite blanking and smoothing signals. As a video data is gated through latch 830, it is converted from digital-to-analog by a digital-to-analog converter 834. Composit sync signals are added to the analog video signals by an adding means 836. After amplification by an amplifier 840, the signals are conveyed to a large TV or video monitor such as would be viewed by the diagnostician.
Signals from PROM 822 are also conveyed to a PROM 850 which performs a gamma correction function. The gamma corrected video signals from PROM 850, along with the other video signals such as from a character, box, or caliber generator, are conveyed to a multiplexer 852 for superimposing as selected. From multiplexer 852, the video signals are conveyed to a latch 854 which is again gated by gate 832. Digital video signals gated through latch 854 are converted by a digital-to-analog converter 856 to analog video signals and combined in an ADDER 858 with composite sync signals. The synced analog data is amplified by an amplifier 860 and conveyed to a small TV or video monitor such as would be coupled with a photographic camera for recording the display. The gamma correction of PROM 850 may be varied to match the photographic film used.
The digital signals generated by analog-to-digital converters 812 and 814, in response to the position and window signals from the control panel, are conveyed to a multiplexer 870. A microcomputer bus port 872 controls multiplexer 870 to cause it to feed the position or window signals to the microcomputer bus port on command. Microcomputer bus port 872 interfaces with the microcomputer bus port for sending this data to the microcomputer.
FIG. 8 shows the details of the box generator. The box generator includes an x sweep intergrater 900 including an amplifier 902 which amplifies a horizontal drive signal, a constant current source 904 and an integrating capacitor 906. The integrated x sweep signal is amplified by an x sweep amplifier means 910 which includes an amplifier 912, a source of an offset voltage 914 and a unity gain inverting amplifier 916 which receives the outputs of amplifier 912 and offset voltage 914 to produce the negative voltage indicative of the x sweep.
Analogously there is a y sweep intergrater 920 again including an amplifier 922, constant current, source 924, and integrating capacitor 926. The integrated y sweep is conveyed to a y sweep amplifier 930 in which an offset voltage 934 is combined with the integrated sweep voltage in amplifier 932 to produce positive y sweep indication.
To position the box on the video display, x and y box offset signals are received and amplified respectively by amplifiers 940 and 942. The amplified x and y offset signals are conveyed to x and y integrate and hold circuits 944 and 946, respectively.
The size of the box is determined by a box gain signal from box shaper 118 which is adjusted by a differential amplifier 948. A summing node 950 sums the outputs of the x sweep amplifier, the x integrate and hold circuit and the box gain amplifier to form one input of a differential amplifier 952 which functions as an x comparator. The outputs of the x sweep amplifier and the x integrate and hold are summed at another summing node 954 with a ground signal to produce one input of a second differential amplifier 956 which acts as another x comparator. The second input of differential amplifier 956 to which the first sum is compared is obtained from a summing node 958 which combines the box gain with a ground signal.
Similarly, a summing node 960 sums the output of the y sweep amplifier, the y integrate and hold circuit and the box gain amplifier to produce one input of a differential amplifier 962. The amplifier 962 compares this sum with the ground signal to function as a y comparator.
Similarly, another summing node 964 sums the output of the y sweep amplifier, the y integrate and hold circuit to form one input of the differential amplifier 966 which acts as another y comparator. A summing node 968, which sums the output of box gain amplifier 948 with a ground signal, compares the second input to differential amplifier 966 with which the voltage at summing node 964 is compared. The outputs of differential amplifiers 952 and 956 are conveyed to a monostable flip-flop 970. Similarly, the outputs of differential amplifier 962 and 966 are conveyed to another monostable flip-flop 972. An enable signal generated when the zoom or box function is to be used, enables flip-flops 970 and 972, respectively. Outputs of flip-flop 970 are conveyed to an OR gate 974 to produce an output which the series of x pulses. Analogously, outputs of flip-flops of 972 are conveyed to an OR gate 976 to produce a series of y pulses.
The output of differential amplifier 952 is inverted and gated with the output of differential amplifier 956 in an AND gate 980. The output of differential amplifier 966 is conveyed to a NOR gate 982 for gating with the output of OR gate 976. The output of NOR gate 982 is gated with the output of differential amplifier 962 in an AND gate 984. The output of AND gate 984 is gated with the x pulses from OR gate 974 in a NAND gate 986.
Similarly, the y pulses from OR gate 976 are gated with the output of AND gate 980 in a NAND gate 988. The x and y pulses, which are passed by NAND gate 986 and AND gate 988, are conveyed to an OR gate 990 whose output is amplified by an amplifier 992.
Thus, as the x and y coordinate positions are indexed at which coordinates of the box should appear, a pulse is conveyed through gate 990.
The invention has been described with reference to the preferred embodiment. Obviously, numerous modifications and alterations will occur to others upon reading and understanding this specification. It is our intention to include all such modifications and alterations insofar as they come within the scope of the appended claims or the equivalents thereof.
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An ultrasonic scanner is disclosed for examining a planar region of a patient. The scanner has a transducer for emitting ultrasonic waves into the planar region of a patient which is defined by an array of subregions separated by subregion boundaries and for transforming echoes received from the planar region into electronic diagnostic values, and an electromechanical device for producing an indication of the position and the angular orientation of the transducer. The scanner also has a main memory having a plurality of addresses corresponding to the subregions for storing such diagnostic value at an address corresponding to the represented subregion, and a CRT display for displaying the diagnostic values stored in the memory. The position indication and angular orientation indication are used for generating the memory address for the diagnostic values corresponding to each echo. The addresses are generated with an analog processor, accumulator and buffer.
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FIELD AND SUMMARY OF THE INVENTION
The present invention refers to an improved device for the false twist drafting of textile material in the form of slubbing. The device conually operates in combination with continuous spinners of the "selfacting" or "ring" type or the like. The device includes two offset and opposite rotating members in order to form portions of rotating walls with annular shoulders which are approximately cone-shaped and surrounded by circular crown front surfaces at right angles to the axis of rotation of the members. The surfaces are partially opposed while the shoulders cooperate tangentially to perform a twist and a draft on the slubbing.
According to the invention, one of the members is mounted to protrude toward the other member, thereby the material may be easily inserted sideways between the two opposite members.
In a possible embodiment of the invention, the members are axially urged toward each other and one of the two rotating members is cantilever mounted on its own shaft on the side facing the other member.
In another possible embodiment of the invention, pairs of spaced apart members are provided on a drive shaft, presenting on their facing fronts, the shoulders and the crown surfaces, and a body of revolution is provided between the two members of each pair which presents two opposite fronts each of which being opposed to the inner front of one of the two members and shaped like the front of it. The body abuts with its own shoulders on those of the two members, is rotatively driven by them and cooperates with them in order to treat two slubbings.
BRIEF DESCRIPTION OF THE DRAWINGS
The drawings show some non-limitative practical examples of the invention wherein:
FIG. 1 is an assembly and schematic view showing use of the invention;
FIG. 2 is an enlarged detail of the device for the treatment of a slubbing according to the invention.
FIG. 3 is a view taken substantially along the line III--III of FIG. 2;
FIG. 4 is a detail of the two false twist members of FIG. 2;
FIG. 5 is a view of a detail of the member surfaces during working; FIGS. 6, 7 and 8 show detailed sections on lines VI--VI, VII--VII and VIII--VIII of FIG. 5;
FIG. 9 is an elevational with FIG. 10 taken on line X--X of FIG. 9, to illustrate a variant of the invention.
FIG. 11 is in front elevation of a modified embodiment;
FIG. 12 is an enlarged detail of another device for the treatment of a slubbing;
FIG. 13 is a sectional view taken substantially on to line XII--XII of FIG. 12;
FIG. 14 is an enlarged detail of FIG. 13; and
FIGS. 15 and 16 show schematic assembly views of two applications to a selfacting spinner and to a divider for carding assortment.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
In FIGS. 1 to 3, 51 indicates the structure of a continuous spinning machine of the so-called "ring" type, with a support 53 for a beam 55 of textile material in the form of slubbing to be spinned, which partially rests on a cylinder 57 which actuates the unwinding of the slubbings S at a constant speed. 59 and 61 indicate small cylinders for feeding the slubbings to the working spans. 63 indicates a thread guide for guiding the thread to an axial position over the relevant spindle 65. Cops 67 are successively inserted on the spindle for the formation of yarn bobbins. The spindle is made to rotate, for example, through belt means 69. 71 indicates the frame making up the ring races for spinning the yarns fed through the thread guides 63. The rotation of the spindle and the reciprocating axial movement between the frame 71 and the spindles, as well as the relative progressive axial displacement between the assemblies, cause the yarn formation along the so-called balloon 73 and the thread winding in the form of reels or cops 75, the relevant ring of each spindle sliding in its own race on the frame 71 around the spindle. A false twist draft is carried out between cylinders 59, 61 and the spinning assembly by a device 77 whose construction and operation is described below.
Along the front of the spindles and above them, a horizontal shaft 79 is supported by the structure 51 and is rotated by the actuating members of the machine. On this shaft and in rotation therewith, friction cylinders 81 are mounted and spaced apart by a pitch corresponding to the one between the spindles 65. Shoulders 83 for spring means 85 are also mounted on shaft 79 for rotation therewith. Between each friction cylinder 81 and each shoulder 83 on shaft 74, a rotating discoidal member 87 is axially slidable, and mounted for rotation with the shaft. In correspondence with each spindle, the structure 51 bears also a support 89 with an arm 91, on which a second member 93 is rotatable and is supported by a shaft 94 protruding toward the rotating member 87. This member 93 may be either idly mounted on or integral to the shaft 94 which, in turn, is idly mounted on the support 89, 91. The shaft 94 is parallel to the shaft 79. The member 93 presents a cylindrical friction surface 95 which is able to cooperate with the respective friction cylinder 81. The arrangement of the support 89, 91 and rotating member 93, 95 is such that the friction cylindrical surface 95 abuts on the friction cylinder 81 to receive the rotation movement from it and thus from the shaft 79. Only one or every one of the surfaces will be elastic. The member 93, being in an axially fixed position, is pressed by the rotating member 87 which is axially urged by the spring 85. The members 93, 95 are cantilever mounted all in the same direction in order to result opposite to the respective rotating members 87 which are urged by respective springs 85.
The cooperation between each member 93 and the relevant member 87, performed in the manner described afterwards, imposes a false twist and a draft to the slubbing in the length between the pair of cylinders 59, 61 and the pair of members 87, 93. The false twist is lost at the outlet of the assembly 77 made up of the operational members 87 and 93, while the material is subjected to the twist due to the ring spinning assembly described above, the twists reaching the material--through the thread guide 63--upon its leaving the device 77.
In the variant shown in FIGS. 9 and 10, the transmission between the shaft 79 and each rotating means 93 is achieved through toothed crowns 81A and 95A--rather than by friction between the elements 81 and 95--whose pitch circles have identical diameters, as also the active surfaces of elements 81 and 95 have identical diameters, to obtain in any case a transmission ratio of 1:1 and opposite rotation directions of the two members 87 and 93.
The way of operation of each false twist device represented by the pair of members 87 and 93 will now be described with reference to FIGS. 4 to 8. In FIGS. 4 to 8, the active members for acting on a slubbing S and causing its stretching comprise two rotating members here denoted by 1 and 3 and corresponding to the members 87 and 93, mounted on the two shafts here denoted by 5 and 7 and corresponding to the shafts 79 and 94. The shafts are parallel and rotate in opposite directions, as indicated by arrows f1 and f3, in order to have a concordant downward direction of rotation in the zone of maximum closeness between the two members 1 and 3, such direction being concordant to the one indicated by arrow fS of downward advancement of the slubbing S. The two members 1 and 3 are mounted in opposite directions and result in contact with each other along a short segment in correspondence with tapered circular shoulders indicated by 1A and 3A of the two members 1 and 3 respectively. The profile of the tapers 1A and 3A may be slightly different from the surfaces having a truncated cone shape and, in any case, ensure a substantially continuous contact along a profile length where the two circular shoulders overlap. It will be noted from the drawing that the two surfaces 1A, 3A having a truncated cone shape and face the offset and opposite members 1, 3, present the laying plans of the minor and major basis offset between them. The distance between the plans containing the minor basis of the surfaces 1A, 3A is indicated by L. By adjusting the position of the members 1 and 3 on the shafts 5 and 7 and by adjusting the center distance between the shafts 5 and 7, it is possible to vary the distance L. A support may be provided between the two members 1 and 3 in a direction which is at right angles to the two shafts 5 and 7. The two members 1 and 3 may be mounted on the shafts 5 and 7, so that in addition to the rotation coupling, they can be urged in order to axially slide in opposite directions to each other according to arrow f7 (FIGS. 3 and 8) on the shaft 5, corresponding to the shaft 79 of FIGS. 1 to 3.
The members 1 and 3 of each working group present, outside the shoulders 1A and 3A, respective surfaces 15A and 17A which overlap in two zones T1 and T3 shown in FIG. 5. The frontal surfaces 15A and 17A superimpose also on the frontal surfaces inside the shoulders 3A and 1A. The interspace between surfaces 15A and 17A corresponds to the one indicated by L as defined above between the minor basis of the frontal end surfaces inside the shoulders 1A and 3A of the members 1 and 3. As a consequence, the adjustment of the relative position between the members 1 and 3 and thus the distance L, determines also the interspace between the frontal surfaces 15A and 17A which overlap at the zones T1 and T3. The surfaces 15A and 17A may be suitably roughened and, in particular, they may present annular concentric grooves which cross at zones T1 and T3. In FIG. 5, C generically denotes the zone of contact, that is the segment of contact between the two tapered surfaces 1A and 3A. Considering in particular the sectional views of FIGS. 5, 6 and 7, it will be noted that--owing to the rotations according to arrows f1 and f3 of the members 1 and 3--the opposite portions of the surfaces 15A and 17A at the zones T1 and T3 are provided with movements which can be resolved into concordant longitudinal components C1, C3 and opposite transversal components C2, C12 in correspondence of the zones T1, and C5, C15 in correspondence of the zones T3. At the segment C of contact between the shoulders 1A and 3A, there occurs only a longitudinal component according to arrow fS, that is according to the sole components C1 and C3 of the contact reactions at that point.
The inserted slubbing S moves approximately tangent--in the contact segment C--to the surfaces of shoulders 1A and 3A, and it is stretched in the direction of arrow fS due to the effect of the direct action of contact with it by the surfaces 3A and 1A in the zone of segment C, and partly due to the effect of components C1 and C3 in the zones T1 and T3 of opposition between the surfaces 15A and 17A. Upstream of the contact segment C, the slubbing S, in addition to undergoing drafting for the reasons stated above, is also subjected to a twist due to a friction effect as a consequence of components C2 and C12 acting on the slubbing with a counter-clockwise torsion in zone T1 as illustrated in FIG. 4. Accordingly, in the zone there occurs a temporary or false twist which is present just at the drafting zone. This false twist is eliminated just beyond the contact segment C, in the zone T3 downstream of the contact segment C, owing to the effect of the torque acting in a clockwise direction (See FIG. 7) and due to components C5, C15. Just beyond the point of contact--represented by segment C--between the textile material and the members 1 and 3, the material in transit may also be effected by the final torsion of the spinning members illustrated in FIG. 1, or by the temporary or false twist of a second drafting and false twisting group.
At the beginning or in case of breakage, the slubbing which is drawn near the rotating members, immediately and spontaneously assumes the working arrangement (substantially symmetrical in the axial views of the device) due to the components acting upon it as soon as it is inserted between the annular elements 15 and 17, or 87 and 93, respectively. Thus, it is a particularly easy task to watch the multiple draft groups provided in a continuous drawing frame and achieved as described above.
Substantially, referring again to FIGS. 1 to 3, due to the action of the device 77 on each slubbing S there is obtained a draft in the free span length between the pair of cylinders 59, 61 and the device 77, owing to the greater return speed of the thread provided by the members 87, 93 of the device 77 with respect to the surface velocity of rollers 59, 61. Such a draft is accompanied by false twist, thereby getting a slubbings regulation with the draft of same slubbings. Most of the false twist is lost after passing the pair of members 87, 93, while the twists of the ring spinning assembly take place at this moment reaching the material upon its outlet from device 77.
At the beginning of the work or on occasion of thread breakage, the material may be easily inserted by the operator between the members 87, 93 of each device 77 always in the same direction according to arrow fx. The material, once inserted in the above mentioned manner, automatically sets itself in the right arrangement already illustrated. This arrangement, instead of having a substantially straight orientation, may be developed according to two slightly inclined lengths, that is as shown in FIGS. 2 and 11, rather than as shown in FIGS. 4 and 5, without altering the system operation.
In order to facilitate the material insertion according to arrows fx, there may be provided at the back of the pairs of members 87, 93 respective shaped stems 100, which guide the material to the correct position where it is subjected to draft and false twist.
In FIG. 11 another embodiment is shown, according to which, rotating members 487 (analogous to those indicated by 87) are mounted on the shaft 479 (equivalent to that indicated by 79) and arranged two by two in opposite directions and thus with the active surfaces facing each other and spaced apart, as well as urged one toward the other. Between the two members 487 there is provided either a friction cylinder 481, or a cylinder with two toothed crowns. In the spacing between the two members 487, a support 489 bears two rotating members 493 (equivalent in those indicated by 93) overhanging at their opposite sides, facing in opposite directions and each one cooperating with the corresponding member 487. In this instance, the insertion of the material between the two specularly symmetrical false twist devices must be carried out according to arrows F2 which are symmetrically inclined. In this case, the false twist is imposed in opposite directions to the two adjacent slubbings S1 and S2 fed by the unit described above and illustrated in FIG. 1, while in the previously described solutions, where the members 93 are oriented in the same direction, the twist is concordant in all the fed slubbings.
The transmission of rotation by friction is simpler and more silent, but it may give rise to some alterations of the transmission ratio in case the material should bunch around a friction surface. On the contrary, a gear transmission does not give rise to alterations of the transmission ratio.
In the embodiment of FIGS. 12 to 14, the assembly of a continuous spinning machine of the so-called ring type is analogous to the one illustrated in FIG. 1 and presents a false twist device 177 in place of that indicated by 77 already described.
Along the front of the spindles and above them, a horizontal shaft 179 carried by the structure 51 is put into rotation by the actuating members of the machine. At pitch spacings corresponding to that between the spindles 65, pairs of members 181 are mounted on the shaft 179 and rotate therewith; each of the members 181 presents a working front with an annular shoulder 183 having a conical profile and a surface 185 outside the shoulder and developed as a circular crown with annular grooves or other friction surfaces. In correspondence with each spindle there is the front of a member 181. Between two facing members 181, the structure 151 bears also a support 189 with an arm 191 forming a saddle within which a body of revolution 193 is housed and rests at a point on the arm 191 as well as on the two shoulders 183 of the two discoidal members 181 approximately facing each other and spaced apart by the distance measured between the faced fronts of the two members 181. More particularly, this body 193 is approximately cylindrical and presents an intermediate annular throat 194 for housing the arm 191, which thus guides the body 193. The body 193 also has two bases facing the shaped fronts 183, 185 of the two members 181 and shaped like these fronts, that is each one having a conical annular shoulder 195 and a circular crown surface 197 with grooves or other friction faces, able to cooperate with the respective friction surface 185 of the opposite front, while the shoulders 195 rest on the respective shoulders 183, so that the body 193 rests on the shoulders 183 and with the bottom of the throat 194 which comes in contact at the point 191A (FIG. 12) with the arm 191. The body 193 may be easily removed from and laid on the members 181, 181, 191 without difficulty, and may be driven into rotation by the shoulders 183. The further contact at 191A may be also carried out through a rolling means in order to reduce friction.
The cooperation between each front 183, 185 of a member 181 and the relevant opposite front or base 195, 197 of a body 193, imposes--in the manner described below--a false twist and a draft to the slubbing over the length between the pair of cylinders 61 (FIG. 1) and the pair of members 181, 193 of the unit 177, the slubbing passing through the shoulders 183 and 195. The false twist is lost at the outlet of the unit 177, while the twist due to the spinning assembly takes place on the material. The twists reach--through the thread guide 61--the material just leaving the unit 177.
The operation of the device 177 is completely analogous to the one described with reference to FIGS. 4 to 8.
While FIG. 1 shows an installation of the device in a continuous ring spinner, FIG. 15 shows instead an installation of the device in an intermittent (self-acting) spinner. In this instance, the slubbings of the cop or beam 201 are unwound by the support cylinder 203. A pair of cylinders 205 feeds the slubbings to the draft and twist device 207 formed according to any of the ways already described. The slubbing S undergoes the draft and false twist over the length S4 between the units 205 and 207. The stretched slubbings leaving the devices 207 form the "stretch" AG which is called back by the spindles carriage 220 when it goes away according to arrow f212 to form the yarn. The devices 207 are operated, in this case, with intermittent movement synchronized to the slubbings feed.
FIG. 16 shows an application of the invention to the divider of a carding assortment, where 351 denotes the doffer, 353 the comb, 355 the dividing unit with the pairs of rubbing leathers 357. At the outlet of the latter there may be possibly provided a pair of feeding cylinders 359 and a device 361 of a type described earlier, for the draft and false twist. The material is then wound around the beams or reels 363 for the next spinning operation.
It will be understood that the drawing shows only an example given as a practical demonstration of the invention, which may vary with regard to form and disposition without coming leaving the basic idea of the invention itself.
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Two offset and opposite rotating members have annular shoulders which are surrounded by frontal surfaces that are being at right angles to the axis of rotation of the members and partially opposed to each other. A first one of the members is mounted on a rotation drive shaft, and is made up of two faced disks, while the other one rests with its own shoulders on the shoulders of the first member and rests also on another point for mutual positioning of the members. Material to be processed may be easily inserted sideways between the two opposite members.
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CROSS-REFERENCE TO RELATED APPLICATIONS
This is a divisional application of co-pending parent application having U.S. application Ser. No. 12/163,944, filed Jun. 27, 2008, which is a continuation of U.S. application Ser. No. 11/106,256, filed Apr. 13, 2005, now U.S. Pat. No. 7,399,401, which is a continuation-in-part (CIP) of U.S. application Ser. No. 10/683,659, filed Oct. 9, 2003, now U.S. Pat. No. 6,916,159, which claims benefit and priority based on U.S. Provisional Application No. 60/417,464, entitled “Disposable Pump For Drug Delivery System,” filed on Oct. 9, 2002, U.S. Provisional Application No. 60/424,613, entitled “Disposable Pump And Actuation Circuit For Drug Delivery System,” filed on Nov. 6, 2002, and U.S. Provisional Application No. 60/424,414, entitled “Automatic Biological Analyte Testing Meter With Integrated Lancing Device And Methods Of Use,” filed Nov. 6, 2002, each of which is incorporated herein in its entirety by this reference. This non-provisional application is also related to U.S. Pat. No. 6,560,471, entitled “Analyte Monitoring Device and Methods of Use,” issued May 6, 2003, which is incorporated herein in its entirety by reference.
FIELD OF INVENTION
This invention generally relates to fluid delivery devices, systems, and methods. This invention further relates to small volume, disposable medical devices for the precision delivery of medicines or drugs such as insulin, and associated systems and methods.
BACKGROUND OF THE INVENTION
Insulin pumps are widely available and are used by diabetic people to automatically deliver insulin over extended periods of time. All currently available insulin pumps employ a common pumping technology, the syringe pump. In a syringe pump, the plunger of the syringe is advanced by a lead screw that is turned by a precision stepper motor. As the plunger advances, fluid is forced out of the syringe, through a catheter to the patient. The choice of the syringe pump as a pumping technology for insulin pumps is motivated by its ability to precisely deliver the relatively small volume of insulin required by a typical diabetic (about 0.1 to about 1.0 cm 3 per day) in a nearly continuous manner. The delivery rate of a syringe pump can also be readily adjusted through a large range to accommodate changing insulin requirements of an individual (e.g., basal rates and bolus doses) by adjusting the stepping rate of the motor. While the syringe pump is unparalleled in its ability to precisely deliver a liquid over a wide range of flow rates and in a nearly continuous manner, such performance comes at a cost. Currently available insulin pumps are complicated and expensive pieces of equipment costing thousands of dollars. This high cost is due primarily to the complexity of the stepper motor and lead screw mechanism. These components also contribute significantly to the overall size and weight of the insulin pump. Additionally, because of their cost, currently available insulin pumps have an intended period of use of up to two years, which necessitates routine maintenance of the device such as recharging the power supply and refilling with insulin.
U.S. Pat. No. 6,375,638 of Clyde Nason and William H. Stutz, Jr., entitled “Incremental Motion Pump Mechanisms Powered by Shape Memory Alloy Wire or the Like,” issued Apr. 23, 2002, and naming Medtronic MiniMed, Inc. as the assignee, which patent is incorporated herein in its entirety by this reference, describes various ratchet type mechanisms for incrementally advancing the plunger of a syringe pump. The ratchet mechanisms are actuated by a shape memory alloy wire. The embodiments taught by Nason et al. involve a large number of moving parts, and are mechanically complex, which increases size, weight and cost, and can reduce reliability.
SUMMARY OF THE INVENTION
A fluid delivery system constructed according to the present invention can be utilized in a variety of applications. As described in detail below, it can be used to deliver medication to a person or animal. The invention can be applied in other medical fields, such as for implantable micro-pump applications, or in non-medical fields such as for small, low-power, precision lubricating pumps for precision self-lubricating machinery.
In its preferred embodiment, the present invention provides a mechanical insulin delivery device for diabetics that obviates the above-mentioned limitations of the syringe pump namely size, weight, cost and complexity. By overcoming these limitations, a precise and reliable insulin delivery system can be produced with sufficiently low cost to be marketed as a disposable product and of sufficiently small size and weight to be easily portable by the user. For example, it is envisioned that such a device can be worn discretely on the skin as an adhesive patch and contain a three-day supply of insulin after the use of which the device is disposed of and replaced.
The present invention relates to a miniature precision reciprocating displacement pump head driven by a shape memory alloy actuator. Shape memory alloys belong to a class of materials that undergo a temperature induced phase transition with an associated significant dimensional change. During this dimensional change, shape memory alloys can exert a significant force and can thus serve as effective actuators. The shape memory alloy actuator provides an energy efficiency about one thousand times greater than that of a conventional electromechanical actuator, such as a solenoid, and a force to mass ratio about ten thousand times greater. Additionally, the cost of shape memory alloy materials compares favorably to the cost of electromechanical devices with similar capabilities.
The device of the present invention is intended to be operated in a periodic dosing manner, i.e., liquid is delivered in periodic discrete doses of a small fixed volume rather than in a continuous flow manner. The overall liquid delivery rate for the device is controlled and adjusted by controlling and adjusting the dosing period. Thus the device employs a precision timing mechanism in conjunction with a relatively simple mechanical system, as opposed to a complex mechanical system, such as that embodied by the syringe pump.
A precision timing device is an inherently small, simple and inexpensive device. It is an underlying assumption of the invention (and a reasonable conclusion of process control theory) that in the treatment of diabetes, there is no clinical difference between administering insulin in periodic discrete small doses and administering insulin in a continuous flow, as long as the administration period of the discrete dose is small compared to the interval of time between which the blood glucose level is measured. For the present invention, a small dose size is regarded as on the order of 0.10 units of insulin (1 microliter) assuming a standard pharmaceutical insulin preparation of 100 units of insulin per ml (U100). A typical insulin dependent diabetic person uses between 10 and 100 units of insulin per day, with the average diabetic person using 40 units of insulin. Thus the present invention would deliver the daily insulin requirements of the average diabetic person in 400 individual discrete doses of 1 μl each with a dosing period that can be programmed by the user. A pump constructed according to the present invention can have a predetermined discrete dosage volume that is larger or smaller than 1 μl, but preferably falls within the range of 0.5 to 5 μl, and more preferably falls within the range of 1 to 3 μl. The smaller the discrete dose is of a particular pump design, the more energy required by the device to deliver a given amount of fluid, since each pump cycle consumes roughly the same amount of energy regardless of discrete dosage size. On the other hand, the larger the discrete dosage is, the less precise the pump can mimic the human body in providing a smooth delivery rate. A device constructed according to the present invention is also suitable for delivery of other drugs that might be administered in a manner similar to insulin.
It is further intended that the present invention could be used as a disposable component of a larger diabetes management system comprised of additional disposable and non-disposable components. For example, the present invention could be coupled with a continuous blood glucose monitoring device and remote unit, such as a system described in U.S. Pat. No. 6,560,471, entitled “Analyte Monitoring Device and Methods of Use,” issued May 6, 2003. In such an arrangement, the hand-held remote unit that controls the continuous blood glucose monitoring device could wirelessly communicate with and control both the blood glucose monitoring unit and the fluid delivery device of the present invention. The monitor and pump could be physically separate units, or could share one or more disposable and/or non-disposable components. For example, a disposable pump constructed according to the present invention and charged with a 3-day supply of insulin, a small battery and a disposable glucose sensor could be integrated into a single housing and releasably coupled with non-disposable components such as control electronics, a transmitter/receiver and a user interface to comprise a small insulin delivery device that could be worn on the skin as an adhesive patch. Alternatively, the battery (or batteries) and/or sensor could be replaced separately from the disposable pump. Such arrangements would have the advantage of lowering the fixed and recurring costs associated with use of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
A detailed description of various embodiments of the invention is provided herein with reference to the accompanying drawings, which are briefly described below.
FIG. 1A shows a schematic representation of a most general embodiment of the invention.
FIG. 1B shows a schematic representation of an alternative general embodiment of the invention.
FIG. 2A shows a schematic representation of a preferred embodiment of the invention.
FIGS. 2B and 2C show enlarged details of a preferred embodiment of the invention.
FIG. 3 shows a schematic representation of a preferred embodiment of a check valve to be used in the invention.
FIG. 4 shows a schematic representation of a preferred embodiment of a pulse generation circuit to be used with the invention.
FIG. 5 shows data from the experimental characterization of the reproducibility of a functional model of the invention.
FIG. 6 shows data from the experimental characterization of the energy utilization of a functional model of the invention.
FIG. 7 shows a schematic representation of a first alternative embodiment of the invention.
FIG. 8 shows a schematic representation of a second alternative embodiment of the invention.
FIG. 9 shows a schematic representation of a first alternative embodiment of a pulse generation circuit to be used with the invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
A device of the present invention includes a miniature precision reciprocating displacement pump driven by a shape memory alloy wire linear actuator and controlled by a programmable pulse generating circuit. For purposes of description, the device is divided into three subcomponents, a precision miniature reciprocating displacement pump head, a shape memory alloy linear actuator, and a programmable pulse generating circuit. Each subcomponent is comprised of multiple elements. A schematic representation of a most general embodiment of the invention is shown in FIG. 1A and is described below.
The miniature precision pump head is comprised of the following elements: a rigid substrate 101 to which other components may be attached so as to fix their orientation and position relative to one another, a fluid reservoir 102 for storing the fluid to be pumped 103 and a small cavity, henceforth referred to as the displacement cavity 104 , whose volume can be varied between precisely defined limits. The limit corresponding to a state of maximum volume for the displacement cavity 104 is defined as the first limit 105 and the limit corresponding to a state of minimum volume for the displacement cavity 104 is defined as the second limit 106 . An inlet conduit 107 connects the displacement cavity 104 to the fluid reservoir 102 and thus permits fluid flow between the two. An inlet check valve 108 is situated within the inlet conduit 107 such that fluid flow is restricted to flowing from the fluid reservoir 102 to the displacement cavity 104 . An outlet conduit 109 connects the displacement cavity 104 to some point 111 to which it is desired to deliver the fluid. An outlet check valve 110 is situated within the outlet conduit 109 such that fluid flow is restricted to flowing from the displacement cavity 104 to the point 111 to which it is desired to deliver the fluid.
The shape memory alloy actuator is comprised of a shape memory allow material, such as a nickel-titanium alloy material, sometimes referred to as “nitinol.” The shape memory alloy material is sensitive to temperature or heat. For example, the material temporarily shrinks at a certain temperature, or shrinkage temperature, such as about 70° C. above ambient temperature for nitinol, and expands at a relatively lower temperature to return to its original condition. In response to being heated to the above-described shrinkage temperature, the shape memory alloy undergoes a dimensional change, such as a change in its length. In this way, a wire composed of a material such as nitinol, can undergo a change in length and a return toward its original length one or more times via temperature treatment or repeated temperature cycling. It is contemplated that a material that expands by going through a phase transition at a certain temperature and shrinks at a different temperature to return toward its original condition could be used.
In the process of undergoing a dimensional change, as described above, the shape alloy material goes through a reversible phase transition or transformation, or a reversible structural phase transition, upon a change in temperature. Generally, such a transition represents a change in the material from one solid phase of the material to another, for example, by virtue of a change in the crystal structure of the material or by virtue of a reordering of the material at a molecular level. In the case of nitinol, for example, the superelastic alloy has a low temperature phase, or martensitic phase, and a high temperature phase, or austenitic phase. These phases can also be referred to in terms of a stiff phase and a soft and malleable phase, or responsive phase. The particular phase transition associated with a particular alloy material may vary.
The shape memory alloy actuator is also comprised of the following elements. A movable member is referred to as a plunger 112 and is fixed by a rigid restraint 113 such that it is constrained to a periodic motion of precisely fixed limits. The plunger 112 is situated in relation to and/or attached to the displacement cavity 104 such that movement of the plunger 112 within the limits of its constrained motion will cause the volume of the displacement cavity 104 to be varied between its limits 105 , 106 . A biasing spring 115 is situated relative to the rigid restraint 113 and the plunger 112 such that at equilibrium, the biasing spring 115 exerts a force on the plunger 112 whose direction is that which would induce the displacement cavity 104 toward a state of minimum volume, i.e., toward its second limit 106 . A length of shape memory alloy wire 114 is connected at one end to the plunger 112 and at another end to the rigid substrate 101 . The shape memory alloy wire 114 is situated such that its dimensional change will give rise to motion of the plunger 112 . The shape memory alloy wire 114 and the biasing spring 115 are both of sufficient dimension such that when the shape memory alloy wire 114 is heated so as to induce phase transition and associated dimensional change, the wire will move the plunger 112 against the force of the biasing spring 115 “in one generally uninterrupted motion” to its second limit 105 so as to create a state of maximum volume within the displacement cavity 104 , whereas when the shape memory alloy is allowed to cool to ambient temperature, the force imparted by the biasing spring 115 will stretch the shape memory alloy wire 114 until the point where the displacement cavity 104 is in a state of minimum volume.
The programmable pulse generating circuit is comprised of a source of electric power 116 , an electrical connection 117 from the source of electric power 116 to each end of the shape memory alloy wire 114 and a programmable pulse generating circuit 118 situated along the electrical connection 117 such that pulses of electricity from the electric power source 116 may be applied to the shape memory alloy wire 114 automatically in a preset regular periodic manner.
Operation of the device proceeds in a cyclic manner. For purposes of description the beginning of the cycle is defined as the following state. All void space within the fluid reservoir 102 , inlet 107 and outlet 109 conduit, inlet 108 and outlet 110 check valves and displacement cavity 104 are completely filled with the fluid 103 to be pumped. The shape memory alloy wire 114 is at ambient temperature and thus in a state of maximum length. Correspondingly, the position of the plunger 112 is such that the volume of the displacement chamber 104 is at its minimum value. The biasing spring 115 is in a compressed state such that it exerts a force on the plunger 112 consistent with a state of minimum volume of the displacement cavity 104 . Operation of the device involves first a heating of the shape memory alloy wire 114 to a temperature and for a period of time sufficient to induce phase transition and an associated dimensional change. Heating of the shape memory alloy wire 114 is accomplished by passing an electric current though it. The duration of the electric heating period is preset and is controlled by the timing and switching circuit 118 . The dimensional change of the shape memory alloy wire 114 will result in the movement of the plunger 112 against the opposing force of biasing spring 115 so as to vary the volume of the displacement chamber 104 toward its first limit 105 and a state of maximum volume. As the volume of the displacement cavity 104 is increased, fluid 103 is drawn into the displacement cavity 104 from the fluid reservoir 102 through the inlet conduit 107 and inlet check valve 108 . Fluid 103 is not drawn into the displacement cavity 104 through the outlet conduit 109 due to the one-way flow restriction of the outlet check valve 110 . After the preset duration, the current is then switched off by the timing and switching circuit 118 allowing the shape memory alloy wire 114 to cool below its phase transition temperature. Cooling proceeds via natural convection to the ambient environment. When the shape memory alloy wire 114 cools below its phase transition temperature, the force exerted by the biasing spring 115 stretches the shape memory alloy wire 114 to its original maximum length. This allows the movement of the plunger 112 so as to vary the volume of the displacement cavity 104 toward its second limit 106 and a state of minimum volume. As the volume of the displacement cavity 104 is decreased, fluid 103 is pushed out of the displacement cavity 104 through the outlet conduit 109 and outlet check valve 110 . Fluid 103 is not pushed out of the displacement cavity 104 through the inlet conduit 107 due to the one-way flow restriction of the inlet check valve 108 . Thus one complete heating and cooling cycle of the shape memory alloy wire 114 results in the delivery of a volume of fluid 103 from the fluid reservoir 102 to the end of the outlet conduit 111 . The volume of fluid delivered with each cycle is precisely equal to the difference between the maximum and minimum volumes of the displacement cavity 104 as determined by the precisely defined limits 105 , 106 . The overall rate of fluid delivery is controlled by varying the period of time between actuations of the shape memory alloy actuator 104 .
An Alternative General Embodiment of the Invention
A schematic representation of an alternative general embodiment of the invention is shown in FIG. 1B . The alternative general embodiment includes all of the same components and elements as the general embodiment shown in FIG. 1A with the following exceptions. In this embodiment of the invention, heating of the shape memory alloy material 114 so as to cause a phase transition associated shortening of its length results in a minimum volume condition for the displacement cavity 104 . This may be achieved, for example, through the use of a pivoting linkage assembly 119 connecting the biasing spring 115 to the plunger 112 .
Detailed Description of a Preferred Embodiment of the Invention
As stated previously, it is an intention of the present invention that it be sufficiently small and sufficiently inexpensive to be practically used as both a portable device and as a disposable device. For example, a device that can be comfortably worn on the skin as an adhesive patch and can be disposed of and replaced after 3 days of use. A preferred embodiment of the invention includes specific embodiments of the various elements and components of the general embodiment that are consistent with this intention.
A preferred embodiment of the invention is diagrammed schematically in FIGS. 2A , 2 B and 2 C and is comprised of all of the same elements and components of the general embodiment of the invention shown in FIGS. 1A and 1B with the following exceptions. In a preferred embodiment of the invention the displacement cavity is comprised of an elastomeric diaphragm pump head 201 . An enlarged view of the details of the diaphragm pump head 201 is shown by FIG. 2B with pump head 201 in a state of minimum volume and by FIG. 2C with pump head 201 in a state of maximum volume. The diaphragm pump head is comprised of an elastomeric diaphragm 202 set adjacent to a rigid substrate 203 and scaled about a perimeter of the elastomeric diaphragm 202 . The displacement cavity 204 is then comprised of the volume in between the adjacent surfaces of the rigid substrate 203 and the elastomeric diaphragm 202 within the sealed perimeter.
Separate inlet 205 and outlet 206 conduits within the rigid substrate 203 access the displacement volume of the elastomeric diaphragm pump head 201 with the inlet conduit 205 connecting the displacement cavity 204 with a fluid reservoir 207 and the outlet conduit 206 connecting the displacement cavity 204 to the point to which it is desired to deliver fluid 208 . An inlet check valve 209 and an outlet check valve 210 are situated within the inlet conduit 205 and outlet conduit 206 respectively, oriented such that the net direction of flow is from the fluid reservoir 207 to the point to which it is desired to deliver fluid 208 .
The plunger 211 is comprised of a cylindrical length of rigid dielectric material. The plunger 211 is situated within a cylindrical bore 212 of a rigid restraint 213 such that the axis of the plunger 211 is oriented normal to surface of the elastomeric diaphragm 202 . The flat head of the plunger 211 is functionally attached to the non-wetted surface of elastomeric diaphragm 202 opposite the displacement cavity 204 such that movement of the plunger 211 along a line of motion coincident with its axis will cause the concomitant variation in the volume of the displacement cavity 204 . The biasing spring 214 is situated within the cylindrical bore 212 of the rigid restraint 213 , coaxial with the plunger 211 . The relative positions and dimensions of the plunger 211 , the rigid restraint 213 and the biasing spring 214 are such that at equilibrium the biasing spring 214 exerts a force on the plunger 211 along a line coincident with its axis such that the displacement cavity 204 is in a state of minimum volume ( FIG. 2A ).
A straight length of shape memory alloy wire 215 is situated in a position coincident with the axis of the plunger 211 . One end of the shape memory alloy wire 215 is fixed to the rigid restraint 203 and electrically connected by connection 216 to the programmable pulse generating circuit 217 and the electric power source 218 . The other end of the shape memory alloy wire 215 along with an electrical connection 219 to that end is connected to the end of the plunger 211 . The shape memory alloy wire 215 and the biasing spring 214 are both of sufficient dimension such that when the shape memory alloy wire 215 is heated so as to induce phase transition and associated dimensional change, it will pull the plunger 211 against the force of the biasing spring 214 so as to create a state of maximum volume within the displacement cavity 204 , whereas when the shape memory alloy is allowed to cool to ambient temperature, the force imparted by biasing spring 214 will stretch the shape memory alloy wire 215 until the point where the displacement cavity 204 is in a state of minimum volume.
A preferred embodiment of an inlet and outlet check valve is shown in cross-section in FIG. 3 and is comprised of a molded one-piece elastomeric valve which can be press-fit into the inlet or outlet conduit. An important feature for a check valve appropriate for use in the present invention is that it possesses a low cracking pressure and provides a tight seal in the absence of any back pressure. A preferred embodiment of such a check valve is comprised of a thin-walled elastomeric dome 301 situated on top of a thick elastomeric flange 302 . The top of the dome has a small slit 303 cut through it that is normally closed. A fluid pressure gradient directed toward the concave side 304 of the dome will induce an expansion of the dome 301 forcing the slit 303 open so as to allow fluid to flow through the valve in this direction. A fluid pressure gradient directed toward the convex side 305 of the dome will induce a contraction of the dome 301 forcing the slit 303 shut so as to prohibit fluid to flow through the valve in this direction.
A preferred embodiment of a pulse generating circuit is shown in FIG. 4 and is comprised of a 200 milliamp-hour, lithium-manganese oxide primary battery 401 , a high capacitance, low-equivalent series resistance (ESR) electrochemical capacitor 402 , a programmable digital timing circuit 403 , and a low-resistance field effect transistor switch 404 . The shape memory alloy wire is indicated in FIG. 4 symbolically as a resistor 405 . The battery 401 and electrochemical capacitor 402 are electrically connected to each other in parallel and are connected to the shape memory alloy wire 405 through the transistor switch 404 . The programmable timing circuit 403 , also powered by the battery 401 , sends a gating signal to the transistor switch 404 , as programmed by the user in accordance with the user's pumping requirements. During the period of time for which the transistor switch 404 is open, the battery 401 will keep the electrochemical capacitor 402 at a state of full charge. During the period of time for which the transistor switch 404 is closed, power will be delivered to the shape memory alloy wire 405 , primarily from the electrochemical capacitor 402 rather than from the battery 401 , owing to the substantially lower ESR associated with the electrochemical capacitor 402 . As such, the battery 401 is substantially isolated from the high current draw associated with the low resistance of the shape memory alloy wire 405 and the useful life of the battery 401 is significantly extended.
A preferred embodiment of a fluid reservoir 207 appropriate for use with the present invention is one for which the volume of the fluid reservoir diminishes concomitantly as fluid is withdrawn such that it is not necessary to replace the volume of the withdrawn fluid with air or any other substance. A preferred embodiment of a fluid reservoir 207 might comprise a cylindrical bore 220 fitted with a movable piston 221 , for example, a syringe, or a balloon constructed of a resilient material.
Operation of the preferred embodiment of the invention proceeds in a manner analogous to that described for the most general embodiment. In addition to its simplicity, the preferred embodiment has the advantage of physically blocking any fluid flow from the fluid reservoir to the point to which it is desired to deliver the fluid when there is no power being supplied to the system. This provides additional protection against an overdose caused by fluid expanding or being siphoned through the check valves when the system is inactive.
Detailed Description of a Functional Model of the Invention
A functional model of a preferred embodiment of the invention has been constructed and its performance has been characterized. The functional model is similar in appearance to the preferred embodiment of the invention shown in FIGS. 2 , 3 and 4 and is described in more detail below. The fixed rigid components of the pump including the rigid restraint and the rigid substrate of the diaphragm pump head are each machined from a monolithic block of acetal. Inlet and outlet conduits are additionally machined out of the same block. Check valves are commercially available one-piece elastomeric valves (for example, Check Valve, Part # VA4914, available from Vernay Laboratories Inc. of Yellow Springs, Ohio). A length of shape memory alloy actuator is 40 mm long and 125 μm in diameter (for example, Shape Memory Alloy Wire, Flexinol 125 LT, available from Mondo-tronics, Inc. of San Rafael, Calif.). Electrical connections to the ends of the shape memory alloy actuator are made with 30 AWG copper wire. The copper wire is twisted to the shape memory alloy wire to effect a good electrical connection. A plunger is machined out of acetal and has an overall length of 10.0 mm and a shaft diameter of 3.2 mm. An elastomer diaphragm is comprised of 0.025 mm thick silicon rubber film (for example, Silicon Rubber Film, Cat. # 86435K31, available from McMaster Carr, of Los Angeles, Calif.). The flat head of the plunger is secured to the elastomer diaphragm with epoxy (for example, Epoxy, Stock #14250, available from ITW Devcon, of Danvers, Mass.). The ends of the shape memory alloy wire-copper conductor assembly are connected to the plunger and to the rigid restraint with epoxy. A stainless steel biasing spring has an overall length of 12.7 mm, an outside diameter of 3.0 mm, a wire diameter of 0.35 mm and a spring constant of 0.9 N/mm (for example, Biasing Spring, Cat. # C0120-014-0500, available from Associated Spring, of Dallas, Tex.).
A pulse generating circuit is comprised of an adjustable analog timing circuit based on a 556 dual timing integrated circuit (for example, 556 Dual Timing Circuit, Part # TS3V556, available from ST Microelectronics, of San Jose, Calif.). Power is supplied by a 3 V lithium-manganese dioxide primary cell (for example, Li/MgO 2 Battery, Part # DL2032, available from Duracell, of Bethel, Conn.). Power load leveling is facilitated by the use of an electrochemical supercapacitor (for example, Electrochemical Supercapacitor, Part # B0810, available from PowerStor Inc., of Dublin, Calif.) in parallel with the battery. High-power switching is achieved with a field effect transistor (for example, Field Effect Transistor Switch, Part # IRLZ24N, available from International Rectifier, of El Segundo, Calif.).
The functional model was characterized with respect to reproducibility, insulin stability and energy consumption. The model was operated by heating the shape memory alloy wire with a short pulse of current and then allowing the shape memory alloy wire to cool. Each heating pulse and subsequent cooling period comprised a single actuation cycle.
A device that is used to automatically deliver a drug to an individual over an extended period of time should do so with extreme precision. This is particularly critical when the drug being delivered is one that might have dangerous health consequences associated with an inappropriate dose. Insulin is one such drug. An excessive dose of insulin can result in dangerously low blood glucose level, which in turn can lead to coma and death. Thus any device to be used for automatically delivering insulin to a diabetic person must be able to demonstrate a very high level of precision. To characterize the precision with which the invention can deliver insulin, the functional model was repeatedly cycled at a constant period of actuation and the total quantity of liquid delivered was measured as a function of the number of actuation cycles. FIG. 5 shows typical results. The data in FIG. 5 were obtained with an actuation period of 28 seconds and a pulse duration of 0.15 seconds. In FIG. 5 markers show actual data points and the line represents a least squares fit of the data points. Data were collected over 8500 cycles at which point the measurement was stopped. The fit to the data has a slope of 1.997 mg/cycle and a linear correlation coefficient of 0.999 indicating that the functional model delivered extremely consistent volumes of liquid with each actuation over the course of the measurement.
Another important requirement for any medical device that handles insulin is that the device does not damage the insulin. Insulin is a large and delicate biomolecule that can readily be damaged by the mechanical action (e.g., shear stress) of a pumping device. Three common modes of insulin destruction which result in a loss of bioactivity are aggregation, where individual insulin molecules bond together to form various polymer structures, degradation, where individual insulin molecules are broken apart, and denaturing, where individual molecules remain intact but lose their characteristic conformation. All three modes of insulin destruction are exacerbated by elevated temperatures. Thus, in the development of a practical insulin pumping device, preferably, it should be demonstrated that the device does not damage insulin. To characterize the insulin stability associated with the invention, a quantity of insulin (Insulin, Humalog U100, available from Eli Lilly, of Indianapolis, Ind.) was set up to recycle continuously through the functional model over the course of several days at 37° C. Samples of the insulin were collected each day for evaluation. This resulted in a series of pumped insulin samples with an increasing amount of pump stress. The insulin samples were then analyzed by reverse-phase high performance liquid chromatography. The chromatography indicated a 2% loss of insulin concentration after a single pass through the pump and a further loss of another 5% of the insulin concentration after 3 days of recycling.
It is desirable for a small and inexpensive insulin delivery device to be able to execute its maximum intended term of use with the energy from a single small inexpensive primary battery. Based on a 0.1 unit dose size and a maximum insulin consumption of 100 units per day for 3 days, a maximum term of use for the inventive device might be considered to be 3000 cycles. To characterize the energy consumption of the invention, the functional model was operated continuously for several days at an actuation period of 85 seconds while the voltage of a 200 milliamp-hour, 2032 lithium/manganese dioxide battery was monitored. FIG. 6 shows typical results. A typical voltage vs. capacity curve for the lithium/manganese dioxide battery is characterized by an initial drop in voltage from about 3.2 V to a plateau voltage of about 2.8 V. The voltage of the battery remains at this plateau level for the duration of its useful life. The battery voltage will then drop precipitously to a value below 2 V when its capacity expires. The data in FIG. 6 indicate that the battery is still at its plateau voltage after 4000 pump cycles and thus the 200 milliamp-hour, lithium/manganese dioxide battery is more than adequate to power the device of the present invention for its intended term of use.
Alternative Embodiments of the Invention
A first alternative embodiment of the invention is diagrammed schematically in FIG. 7 and is comprised of all of the same subcomponents and elements of the most general embodiment of the invention shown in FIG. 1 with the following exceptions. In a first alternative embodiment of the invention, the displacement cavity, as well as the inlet and outlet conduit, are all comprised of a single length of small-diameter flexible and resilient tubing 701 . The tubing 701 is situated within a restraining fixture 702 secured to a rigid base 703 so as to fix the position and orientation of the tubing 701 relative to the other elements of the device. Inlet 704 and outlet 705 check valves are located within the bore of the tubing 701 such that they have a common orientation for flow direction and such that a length of empty tubing 701 exists in between the two check valves 704 , 705 . The volume within the inner diameter of the tubing 701 and in between the two check valves 704 , 705 comprises a displacement cavity 706 . The volume of the displacement cavity 706 is varied by compressing the resilient tubing 701 with a plunger 707 (described below) at a position midway between the two check valves 704 , 705 . The volume within the inner diameter of the tubing 701 and in between the two check valves 704 , 705 when the tubing 701 is uncompressed defines the maximum volume of displacement cavity 706 . The volume within the inner diameter of the tubing 701 and in between the two check valves 703 , 704 when the tubing 701 is fully compressed by the plunger 707 defines the minimum volume of the displacement cavity 705 .
The plunger 707 is comprised of a cylindrical length of rigid dielectric material and includes a flange 708 and a tapered end 709 . The plunger 707 is situated within a cylindrical bore 710 of a rigid restraint 711 such that the axis of the plunger 707 is oriented normal to the axis of the resilient tubing 701 and such that the tapered head 709 of the plunger 707 may be alternately pressed against the resilient tubing 701 and removed from contact with the resilient tubing 701 with movement of the plunger 707 along a line of motion coincident with the its axis. A biasing spring 712 is fitted around the shaft of the plunger 707 in between the rigid restraint 711 and the plunger flange 708 . The relative positions and dimensions of the plunger 707 , the rigid restraint 711 and the biasing spring 712 are such that at equilibrium the biasing spring 712 exerts a force on the plunger 707 along a line coincident with its axis that is sufficient to fully collapse the resilient tubing 701 and thus create a state of minimum volume of the displacement cavity 706 .
A straight length of shape memory alloy wire 713 is situated in a position coincident with the axis of the plunger 707 . One end of the shape memory alloy wire 713 is attached to the rigid base 703 and electrically connected by connection 716 to the pulse generating circuit 714 and the electric power source 715 . The other end of the shape memory alloy wire 713 along with an electrical connection 717 to that end is attached to the shaft of the plunger 707 . The shape memory alloy wire 713 is of sufficient length and strength that when heated so as to induce phase transition and associated dimensional change it will pull the plunger 707 away from contact with the resilient tubing 701 against the opposing force of the biasing spring 713 .
A second alternative embodiment of the invention is diagrammed schematically in FIG. 8 and is comprised of all of the same subcomponents and elements of the most general embodiment of the invention shown in FIG. 1 with the following exceptions. A displacement cavity 801 is comprised of a cylindrical shell 802 and tube 803 arrangement where the tube 803 is coaxial with the shell 802 and can move freely within the shell 802 along a line coincident with that axis. The volume of the displacement cavity 801 is varied by moving the tube 803 relative to the shell 802 . Movement of the tube 803 into the shell 802 reduces the volume of the displacement cavity 801 whereas movement of the tube out of the shell increases the volume of the displacement cavity 801 . A dynamic seal 804 , for example and elastomer o-ring, seals the displacement cavity 801 while not interfering adversely with the relative motion of the shell 802 and tube 803 . Outlet 805 and inlet 806 conduits access the displacement cavity 801 through the ends of the shell 802 and tube 803 respectively. Outlet 807 and inlet 808 check valves are situated within the shell 802 and tube 803 respectively. A biasing spring 809 is situated within the displacement cavity 801 so as to resist the motion of the displacement cavity 801 toward a state of reduced volume. A shape memory alloy wire 810 is attached between the shell 802 and the tube 803 along the outside of the assembly such that when the shape memory alloy wire 810 is heated so as to induce phase transition and associated dimensional change it will incline the displacement cavity 801 toward a state of reduced volume. The shape memory alloy wire 810 is electrically connected by connector 811 to a programmable pulse generating circuit 812 and a source of electric power 813 . Hard stops (not shown) on the limits of the relative positions of the shell 802 and tube 803 define the maximum and minimum volumes of the displacement volume 801 .
Operation of both the first and second alternative embodiments of the invention proceed in a manner analogous to that described for the most general embodiment and preferred embodiment of the invention.
In all of the embodiments described above, a shape memory alloy wire acts as an actuator to drive a movable member to increase or decrease the fluid volume in the pump head, and once the wire cools a spring is used to return the movable member back to its original position. Those of reasonable skill in this field will appreciate that a multitude of other biasing means exist, one or more of which can be used in place of or in addition to the spring. In fact, a shape memory alloy can be constructed in such a way that it drives the movable member in both directions to act as both an actuator and a return biasing element. For example, the shape memory alloy can be coiled much like a spring to drive the movable member in one direction when heated and in the other direction when cooled.
A first alternative embodiment of a pulse generating circuit is diagrammed schematically in FIG. 9 and is comprised of a 200 milliamp-hour lithium-manganese dioxide primary battery 901 , a DC to DC converter 902 , a capacitor 903 , a low-resistance field effect transistor switch 904 , a programmable digital timing circuit 905 , an inductor 906 and a diode 908 . The shape memory alloy wire is indicated in FIG. 9 symbolically as a resistor 907 . The objective of this embodiment of a pulse generating circuit is that the pulses of power delivered to the shape memory alloy wire 907 can be of a higher voltage, and thus higher current, than that associated with the preferred embodiment of a pulse generating circuit diagrammed in FIG. 4 and described previously. A high voltage, high current power pulse has the advantage that it can actuate the circuit in a shorter more efficient time period. Additionally, the alternative embodiment of a pulse generating circuit allows the useful life of the battery 901 to be extended to a lower voltage and can prevent other circuitry powered by the battery from resetting when the battery voltage droops as is likely to happen in the preferred embodiment. The battery 901 and capacitor 903 are electrically connected to each other in parallel through the DC to DC converter 902 . The capacitor 903 is further connected to the shape memory alloy wire 907 through the transistor switch 904 . The programmable timing circuit 905 , also powered by the battery 901 sends a gating signal to the transistor switch 904 as programmed by the user in accordance with their pumping requirements. During the period for which the transistor switch 904 is open, the DC to DC converter 902 draws energy from the battery 901 and stores it in the capacitor 903 . Use of the DC to DC converter 902 allows the voltage of the capacitor 903 to be charged to a significantly higher value than that associated with the battery 901 and to be charged to the same voltage throughout the life of the battery 901 regardless of the battery voltage. It is intended that the transistor switch 904 may be modulated to send an overall energy pulse as a single pulse or as a sequence of discrete smaller pulses. It is intended that these smaller pulses may be sequenced so as to tailor a custom profile for the overall energy pulse. The custom profile would ensure optimal energy delivery to the shape memory alloy without exceeding its fusing characteristics. The inclusion of the inductor 906 and diode 908 allows current to continue to flow through the shape memory alloy wire 907 after the transistor switch 904 is opened when the pulse is modulated. This allows further control of the energy delivered to the shape memory alloy.
Various references, publications, provisional and non-provisional United States patent applications, and/or United States patents, have been identified herein, each of which is incorporated herein in its entirety by this reference. Various aspects and features of the present invention have been explained or described in relation to beliefs or theories or underlying assumptions, although it will be understood that the invention is not bound to any particular belief or theory or underlying assumption. Various modifications, processes, as well as numerous structures to which the present invention may be applicable will be readily apparent to those of skill in the art to which the present invention is directed, upon review of the specification. Although the various aspects and features of the present invention have been described with respect to various embodiments and specific examples herein, it will be understood that the invention is entitled to protection within the full scope of the appended claims.
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A system for the metering and delivery of small discrete volumes of liquid is comprised of a small or minimal number of inexpensive components. One such component is a movable member, such as a miniature precision reciprocating displacement pump head, which is driven by an actuator that comprises a shape memory alloy material. The operating mechanism of the system is of little or minimal complexity. The system facilitates the precise metering and delivery of the small discrete volumes of liquid. Potential applications for the system include subcutaneous, long-term, automated drug delivery, for example, the delivery of insulin to a person with diabetes. In such an application, the small, simple and inexpensive nature of the invention would allow for its use as both a portable and a disposable system.
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BACKGROUND
The invention generally relates to a technique for continuous modulation of Orthogonal Frequency Division Multiplexing (OFDM) signals.
Many recent implementations of digital wireless communication systems (wireless or cable-based systems, for example) use Orthogonal Frequency Division Multiplexing (OFDM) for environments where there is strong interference or multipath reflections. However, one disadvantage of using OFDM is the use of a Fast Fourier Transform (FFT) and an inverse FFT (IFFT) in the demodulator (for an OFDM transmitter) and modulator (for an OFDM receiver), respectively. In this manner, as described below, the calculation of the FFT and inverse FFT may add a considerable amount of complexity to OFDM transmitter/receiver due to the large processing block that is required on each end of the communication link.
For purposes of maximizing statistical multiplexing gain, many communication systems assign subsets of OFDM subcarriers to individual users, terminals or electrical devices in both the upstream and downstream directions. In this manner, the data associated with a particular user, terminal or electrical device is modulated via the associated subset of OFDM subcarriers. The resultant OFDM modulated signal is then modulated via an RF carrier signal, and the resultant signal is transmitted over a wireless link. This OFDMA modulation technique is commonly called OFDMA for Orthogonal Frequency Division Multiple Access.
The IFFT is an N point operation, i.e., the IFFT is based on a set of N subcarriers. In this manner, for the OFDM transmitter, the data that is assigned to a particular subset of these subcarriers forms an IFFT input data vector that is processed via the IFFT to produce a digital signal. This signal represents the modulation of the data with the subset of subcarriers. The IFFT involves numerous mathematical operations (accumulate and multiply operations, for example) and requires an input data vector of N coefficients.
It is possible that some of the OFDM subcarriers may not be assigned to a particular transmitter. As a result, the block computation of the IFFT for OFDM modulation may involve using zeros for the N coefficients (of the IFFT input data vector) that are associated with the unassigned subcarriers. As a result of the use of these zero value coefficients, many zero result mathematical operations in the IFFT are performed, thereby resulting in inefficient computation of the IFFT.
Thus, there is a continuing need for an arrangement or technique to address one or more of the problems that are stated above.
BRIEF DESCRIPTION OF THE DRAWING
FIG. 1 is a schematic diagram of an OFDMA transmitter according to an embodiment of the invention.
FIG. 2 is an illustration of the generation of an OFDM symbol according to the prior art.
FIG. 3 is a signal flow diagram for computation of an inverse Radix-two IFFT according to the prior art.
FIG. 4 is a signal flow diagram for the computation of an IDFT according to an embodiment of the invention.
FIG. 5 is a flow diagram depicting a modulation technique according to an embodiment of the invention.
FIG. 6 is a table depicting a comparison of the modulation technique of the present invention and a modulation technique of the prior art.
FIGS. 7 and 9 are waveforms depicting real and imaginary components of OFDM subcarriers according to an embodiment of the invention.
FIG. 8 is a flow diagram depicting a technique to generate an OFDM guard interval according to an embodiment of the invention.
FIG. 10 is a flow diagram depicting a technique to generate a cyclic prefix according to an embodiment of the invention.
FIG. 11 is a schematic diagram of a wireless communication system according to an embodiment of the invention.
DETAILED DESCRIPTION
Referring to FIG. 1 , an embodiment 10 of an OFDMA transmitter in accordance with the invention receives data to be transmitted over a communication link, such as a cable-based or wireless link, as examples. As an example, referring also to FIG. 11 , the transmitter 10 may be used as part of a receiver 204 /transmitter 10 pair 209 (two shown in FIG. 11 , as an example) in a wireless communication system 200 , such as a wireless local area network (LAN), for example.
As part of the wireless communication system 200 , the transmitter 10 is assigned a subset of OFDM subcarriers for use in transmitting the data over a wireless link 203 to other wireless devices 205 . In this manner, the assigned subset of OFDM subcarriers may be used to communicate data associated with a particular user, terminal or electrical device 210 that is coupled to the pair 209 for purposes of communicating over the wireless link 203 .
Referring to FIG. 1 , during its course of operation, an encoder 12 of the transmitter 10 receives data (via communication lines 11 ) to be transmitted over the wireless link 203 ( FIG. 11 ), and this data is updated at a predefined sampling rate. The encoder 12 may, for example, introduce an error correcting scheme into the data. The encoder 12 may also perform other operations on the received data, such as a mapping operation, for example. More specifically, the encoder 12 may map the data received by the encoder 12 into a complex value space using quadrature amplitude modulation (QAM). Other and different operations by the encoder 12 are possible.
The encoder 12 provides the encoded data (via communication lines 13 ) to an Inverse Discrete Fourier Transform (IDFT) engine 14 of the transmitter 10 . The IDFT engine 14 includes a processor 31 that executes instructions 33 that, in turn, are stored in a memory 35 of the IDFT engine 14 . The encoded data may be viewed as being divided into segments, with each segment representing a coefficient that is associated with one of the assigned subcarriers.
As described below, the IDFT engine 14 modulates these coefficients with the assigned subcarriers to produce a time-varying digital signal. This digital signal, in turn, is communicated (via communication lines 19 ) to a digital-to-analog converter (DAC) 20 that converts the digital signal into an analog signal. Analog transmission circuitry 23 subsequently modulates this analog signal with at least one radio frequency (RF) carrier signal and transmits the resultant RF signal by driving an antenna 44 in response to the RF signal.
The digital signal that is produced by the IDFT engine 14 forms the information for OFDM symbols that are indicated by the signal that is transmitted by the antenna 44 . In this manner, each basic OFDM symbol is formed from an N point IDFT and has a duration that is equal to a periodic rate at which the OFDM symbols are generated. When viewed in the frequency domain, each basic OFDM symbol includes sinc functions that are located at the frequencies of the OFDM subcarriers.
Because the transmitted OFDM symbols may travel along different paths, interference may occur between symbols that are transmitted at different times. This interference, in turn, may degrade the orthogonality of the OFDM modulation and as a result, may prevent full recovery of the transmitted data. To prevent this interference, the IDFT engine 14 extends the length of the basic OFDM symbol by a guard interval, an extension that extends the current OFDM symbol's transmission beyond the time when a reflected previously transmitted OFDM symbol would interfere. The generation of the guard interval is discussed below.
The IDFT engine 14 differs from its inverse Fast Fourier Transform (IFFT) counterpart that is found in a conventional OFDMA transmitter. In this manner, a conventional OFDM transmitter uses the IFFT to calculate the IDFT, as for certain conditions the IFFT uses symmetry to reduce the number of required mathematical operations to compute the IDFT. The IFFT requires, however, an IFFT input data vector that contains coefficients for all of the OFDM subcarriers, regardless if fewer than all of the subcarriers are assigned for purposes of modulation by the transmitter 10 . The traditional OFDM transmitter accommodates this scenario by using zero values in the IFFT input data vector for the coefficients that are associated with unassigned subcarriers. However, this conventional technique requires that mathematical operations (multiplication and accumulation operations, for example) still have to be performed in connection with these non-assigned subcarriers, resulting in numerous zero result computations and inefficient modulation.
In contrast to a conventional OFDMA transmitter, the transmitter 10 uses the IDFT engine 14 that, in its computation of the IDFT, only performs mathematical operations that are associated with assigned subcarriers and does not perform such mathematical operations that are associated with unassigned subcarriers. Thus, the IDFT engine 14 performs continuous OFDM modulation.
To further illustrate this difference, FIG. 2 depicts the generation of an OFDM symbol 50 using the conventional IFFT technique. As shown, in the prior art, data 62 for assigned subcarriers is passed into an IFFT engine 56 that generates a cyclic prefix 52 as well as the basic OFDM symbol 54 . The duration of the basic OFDM symbol 54 defines the period of OFDM signal generation. Zero value data 60 for unassigned subcarriers completes the IFFT input vector for the IFFT engine 56 .
The event of the mathematical operations that are performed in conventional OFDMA transmitters because of the processing of zero value coefficients for the non-assigned subcarriers becomes apparent when a signal flow diagram of the IFFT is examined. For example, FIG. 3 depicts a signal flow diagram for the computation of an inverse radix-two IFFT. As shown, for an eight-point IFFT, three stages 82 , 84 and 86 are required to compute the IFFT. Additional stages must be added to compute a larger IFFT. As depicted in FIG. 3 , each discrete output value from the last stage 86 depends on every input coefficient. Thus, introducing a zero value for one of the input coefficients produces a significant number of mathematical operations that produce a value of zero.
In contrast to the conventional OFDMA transmitter, the transmitter 10 includes the IDFT engine 14 that calculates discrete time values (called x n ) pursuant to the following expression:
x n = ∑ f = 0 N - 1 X f · ⅇ - j2π f n / N , Equation 1
where “f” is an integer representing a discrete subcarrier frequency index (and thus, each different value for “f” references a different subcarrier); “N” represents the length of the IDFT and the number of subcarriers; and “X f ” represents the coefficients (of the IDFT input vector) to be modulated. The expression “e −2πfn/N ” represents a complex exponential value that is associated with a particular subcarrier, as selected by the “f” index. Thus, the coefficient “X 1 ,” for example, is associated with a subcarrier that is referenced by a “1” for the “f” index.
Using Equation 1, the IDFT engine 14 calculates each x n discrete value by performing mathematical operations (multiply and accumulate operations, for example) only with the X f coefficients components that are associated with assigned subcarriers. Referring to FIG. 4 , in this manner, to compute the IDFT for a particular x n value, a maximum of N multiply operations 92 are needed, and the results of the operations 92 are accumulated as indicated by reference numeral 94 . However, the IDFT engine 14 selectively performs these multiply operations 92 , as the operations 92 that are associated with non-assigned subcarriers are skipped.
For example, if the subcarrier that is associated with a “f” index of “1” is not assigned, then the IDFT engine 14 does not perform the multiply operation 92 a in the calculation of any of the x n values. Not only are “n” multiply operations not performed for this example, accumulate operations to accumulate zero value multiplication results are also not performed, thereby resulting in more efficient modulation.
Thus, the IDFT engine 14 may, in some embodiments of the invention, use a technique 100 that is depicted in FIG. 5 for the calculation of each x n value. To perform the technique 100 , as well as other techniques described herein, the processor 31 of the IDFT engine 14 may execute the instructions 33 (see FIG. 1 ) that are stored in the memory 35 . In the technique 100 , the IDFT engine 14 initializes (block 101 ) the “f” index to zero and determines (block 102 ) the subcarriers that have been assigned to the transmitter 10 for purposes of modulating data that is received by the transmitter 10 . In this manner, the transmitter 10 is assigned a subset of the OFDM subcarriers that are available for communication over the wireless link 203 (see FIG. 11 ), and this subset may be dynamically reassigned. The IDFT engine 14 may receive an indication of the current assigned subset via communication lines 243 (see FIG. 1 ) that are coupled to the OFDM receiver 204 (part of the OFDM receiver transmitter pair 209 ) that decodes received information indicating reallocation of the subcarriers.
Subsequently, in the technique 100 , the IDFT engine 14 determines (diamond 104 ) whether the subcarrier that is associated with the current value of the “f” index is assigned. If not, then control transfers to block 110 where the “f” frequency index is incremented by one. If the subcarrier that is associated with the current value of the “f” index is assigned, then the IDFT engine 14 calculates (block 106 ) the next component of the x n value by multiplying the complex exponential (see Eq. 1) that is indexed by the “f” index with the appropriate coefficient. Subsequently, the IDFT engine 14 adds (block 108 ) this component of the x n value to the other computed components, and control returns to block 110 where the “f” frequency index is incremented by one.
Next, the IDFT engine 14 determines (diamond 111 ) by examining the value of the “f” frequency index whether all components of the IDFT have been calculated. If not, control returns to diamond 104 . Otherwise, the IDFT engine 14 terminates the routine 100 , as the value of a particular x n value has been computed. Thus, the IDFT engine 14 uses the technique 100 to calculate each x n value.
As an example, a table 112 in FIG. 6 depicts a comparison of the technique 100 used by the IDFT engine 14 with Radix-2 IFFT computations. In particular, the entries in column 113 are different numbers of available OFDM subcarriers (assigned and unassigned); the entries in column 114 are the numbers of computations required by the Radix-2 IFFT computations for the different available OFDM subcarriers; and the entries of column 116 define points where the calculations of the IDFT engine 14 are more efficient than the calculations of the Radix-2 IFFT. In this manner, for the case where the number of assigned subcarriers (column 113 ) does not exceed the values indicated in column 116 , the technique provided by the IDFT engine 14 provides a computational benefit over the conventional IFFT-based modulation.
For example, if the total number of available subcarriers is sixty four (row 3 of table 112 ), then as long as six or less subcarriers are assigned, the IDFT engine 14 is computationally more efficient than an engine that uses Radix-2 IFFT computations.
Cyclic extensions of OFDM symbols are commonly used to provide guard intervals to combat channel multipath effects. The guard interval for a particular OFDM symbol may be inserted ahead of (called a cyclic prefix) or behind (called a cyclic extension) the basic OFDM symbol. However, regardless of whether a cyclic prefix or extension is added, either scheme may be simplified using the technique used by the IDFT engine 14 , as described below.
For example, in some embodiments of the invention, the IDFT engine 14 creates a cyclic extension by generating x n discrete values for values of “n” that exceed “N.” In other words, the symbol generation extends beyond the period that is defined by the rate at which the basic OFDM symbols (without guard intervals) are generated.
For example, FIG. 7 depicts a real component 120 and an imaginary component 122 of one subcarrier and a real component 124 and an imaginary component 126 of another subcarrier. Initially, the phases of these subcarriers are aligned, and when “n” is equal to “N” (two hundred seventy five, for example), as indicated by the vertical line 125 , the interval in which the basic OFDM symbol is generated has elapsed. However, as shown, the IDFT engine 14 continues the IDFT beyond that interval to generate the cyclic extension.
Thus, in some embodiments of the invention, the IDFT engine 14 may use a technique 130 (see FIG. 8 ) to generate the x n values and generate the cyclic extension. In this manner, in the technique 130 , the IDFT engine 14 determines (diamond 132 ) whether “n” is equal to “N.” If so, the IDFT engine 14 determines (diamond 134 ) whether a cyclic extension is to be generated, and if so, the IDFT engine 14 determines (diamond 135 ) whether “n” is equal to “M,” an index used to indicate the end of the cyclic extension.
If “n” is less than “N” for the case where no cyclic extension is to be generated or “n” is less than “M” for the case where a cyclic extension is to be generated, then the IDFT engine 14 proceeds to block 136 . Otherwise, all of the x n values for the current OFDM symbol have been generated, and the technique 130 is terminated. In block 136 , the IDFT engine 14 computes the x n value in accordance with the technique 100 described above. Next, the IDFT engine 14 increments (block 138 ) “n” by one and control returns to diamond 132 .
FIG. 9 depicts a scenario in which the IDFT engine 14 appends a cyclic prefix to the basic OFDM symbol. In this manner, FIG. 9 depicts a real component 151 and an imaginary component 152 of one subcarrier and a real component 154 and an imaginary component 156 of another subcarrier. The phases of the subcarriers are aligned beginning with “n” being equal to approximately twenty five (for this example), as indicated by a vertical line 150 . Thus, from the time from when “n=0” to when “n=25,” the IDFT engine 14 generates a cyclic prefix.
In some embodiments of the invention, the IDFT engine 14 generates the cyclic prefix by rotating the frequencies of the subcarriers. For example, if the cyclic prefix is ten percent of the length of the OFDM generation interval, then the IDFT engine 14 selectively pre-rotates the phase of each subcarrier by −2π·0.1·n·f radians, where “f” is the frequency index defined above and “n” is an integer.
Thus, to generate the cyclic prefix, in some embodiments of the invention, the IDFT engine 14 performs a technique 170 that is depicted in FIG. 10 . In the technique 170 , the IDFT engine 14 determines (diamond 172 ) whether a cyclic prefix is to be generated. If so, then the IDFT engine 14 determines (diamond 174 ) the needed rotation of the subcarrier frequencies and then subsequently rotates (block 175 ) the subcarrier frequencies by the determined amount.
In some embodiments of the invention, the IDFT engine 14 may also perform symbol shaping to reduce sidelobes in the frequency domain. Conventional transmitters may perform such symbol shaping by applying a weighting function (a Raised-Cosine function) in the time domain. However, instead of applying a weighting function in the time domain, the IDFT engine 14 may, in some embodiments of the invention, apply the weighting function in the frequency domain due to the commutativity of the multiplication operations used by the IDFT engine 14 . In this manner, as described above, for each x n value, the IDFT described above multiplies a coefficient that is associated with a particular subcarrier frequency with a complex exponential function that is associated with the subcarrier frequency. Thus, to apply a weighting function, each coefficient may be scaled according to the weighting function to apply the weighting function in the frequency domain.
Alternatively, the weighting function may be applied in the time domain before the IDFT, thereby providing another advantage to the technique that is described herein.
Other embodiments are within the scope of the following claims. For example, although an IDFT is described for purposes of modulation, a DFT instead of the IDFT may be used for modulation using the zero data skipping technique that is described above. In this manner, for these embodiments, the receiver that receives the OFDM symbols uses an IDFT engine for purposes of demodulation. Thus, the term “discrete frequency transformation,” as used in the context of this application, may mean either a discrete frequency transformation or an inverse discrete frequency transformation.
While the invention has been disclosed with respect to a limited number of embodiments, those skilled in the art, having the benefit of this disclosure, will appreciate numerous modifications and variations therefrom. It is intended that the appended claims cover all such modifications and variations as fall within the true spirit and scope of the invention.
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A technique includes basing a discrete frequency transformation on the number of subcarriers in a predetermined set of subcarriers. One or more subcarriers of the set are assigned to modulate data, and the remaining subcarriers of the set are not assigned to modulate the data. The discrete frequency transformation is performed on the data to modulate the data, and mathematical operations that are associated with the subcarriers not assigned to modulate the data are excluded from the transformation.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to semiconductor devices and more specifically to the structures of semiconductor devices having a fuse layer disconnected through light radiation so as to control a redundant circuit.
2. Description of the Background Art
It has been well known to provide a redundant circuit for recovering semiconductor devices from defects. In general, a fuse layer is formed together with the redundant circuit. The fuse layer that is disconnected as appropriate allows a defective circuit to be replaced by the redundant circuit. A semiconductor device with such a fuse layer is disclosed e.g. in U.S. Pat. No. 5,589,706.
FIG. 19 shows a schematic configuration of a dynamic random access memory (DRAM) as one example of a semiconductor device with a redundant circuit. Referring to FIG. 19, a memory cell array 20 includes a word line WL extending in a row direction from a row decoder 21 via a word driver 22 , and a bit line BL extending in a column direction from a column decoder 23 . Word line WL and bit line BL are crossed with each other. A memory cell MC is provided at a crossing of word line WL and bit line BL.
Outside word line WL, a spare word line SWL extends in the row direction from a spare decoder 24 via a spare word driver 25 . A spare memory cell SMC is provided at a crossing of spare word line SWL and each bit line BL.
Spare memory cell SMC, spare decoder 24 and spare word driver 25 configure a redundant circuit. Spare decoder 24 connects with a defective-address comparing circuit 26 in which a fuse layer is formed. The fuse layer controls the redundant circuit. Defective-address comparing circuit 26 receives row addresses. FIG. 20 shows a fuse layer of a DRAM configured as above and a vicinity of the fuse layer in cross section.
Referring to FIG. 20, a fuse layer 3 is formed on a semiconductor substrate 1 , with an interlayer insulation film 2 interposed therebetween. Fuse layer 3 is covered by an insulation layer 4 formed e.g. of silicon oxide film.
A defective circuit is recovered by disconnecting fuse layer 3 configured as described above. In general, laser light is employed to disconnect fuse layer 3 . The principle of the disconnection of fuse layer 3 through laser light will now be described.
Referring again to FIG. 20, laser light 5 illuminates fuse layer 3 . Thus, laser light 5 is absorbed by fuse layer 3 and fuse layer 3 is thus heated. Consequently, fuse layer 3 changes in phase from solid to liquid to gas. Thus, the evaporation pressure of fuse layer 3 pushes isolation layer 4 upwards to create a crack 9 in isolation layer 4 , as shown in FIG. 21 .
When the evaporation pressure of fuse layer 3 exceeds a predetermined value, fuse layer 3 is disconnected and insulation layer 4 overlying fuse layer 3 is blown away to create a blow trace 4 a , as shown in FIG. 22 .
Conventional fuse layers are often designed in view of electrical characteristics, processing convenience and the like. Accordingly, in shifting to semiconductor devices having a structure of a new generation, a member totally different from that of the previous generation can be adopted as a fuse layer, a plurality of fuse layers provided can each have a different dimension, and each fuse layer can be surrounded by an oxide film having a different thickness. As a result, blow traces created by fuse layer disconnection cannot have a uniform dimension and this results in a disadvantage that a fuse layer can not be disconnected reliably.
Furthermore, it has been increasingly difficult to disconnect an underlying fuse layer due to high integration of elements configuring a semiconductor device and to an increased film thickness associated with a reduced number of the steps of the process for manufacturing the same. Currently, an interconnection layer located as high as possible is increasingly used as a fuse layer.
The interconnection layer located as high as possible is formed mainly of metal material. It has been known, however, that metal material increases the reflection of illumination light from the interconnection layer in transferring an interconnection pattern onto the interconnection layer and the interconnection pattern cannot be transferred satisfactorily. To address this disadvantage, a film is provided on the surface of the interconnection layer to reduce the reflection of illumination light.
An anti-diffusion film is also provided between the semiconductor substrate and the interconnection layer of metal to prevent the ions of the silicon of the semiconductor substrate from diffusing into the interconnection layer. From the reason provided above, a three-layered structure is frequently used for the interconnection layer adopted as a fuse layer.
The fuse layer structured of three layers is, however, structurally not preferable in disconnecting the fuse layer. Furthermore, the region provided with the fuse layer is lower in interconnection density than a memory region. As a result, if the process for forming an interconnection layer in the memory region is similar to that for forming an interconnection layer in the fuse layer, the cross section of the fuse layer varies from location to location due to the low interconnection density.
Furthermore, when the beam wavelength of the laser light illuminating the fuse layer is approximately equal in dimension to the width of the fuse layer and the beam diameter of the laser light is larger than the width of the fuse layer, the profile of the light absorbed by the fuse layer significantly depends on the shape of the fuse layer and this results in a very complicated profile of the light absorbed by the fuse layer.
The laser light absorption into the fuse layer allows the optical energy of the laser light to be transformed into thermal energy so that the fuse layer changes in phase from solid to liquid to gas and the fuse layer is thus disconnected. While the light-absorption profile corresponds to heat-emission profile, it is difficult to reliably disconnect the fuse layer and obtain a smaller blow trace depending on the structure of the fuse layer when the heat-emission profile of the fuse layer is a profile which is not suitable for disconnecting the fuse layer.
SUMMARY OF THE INVENTION
The present invention has been made to overcome the disadvantages described above.
One object of the present invention is to provide a semiconductor device having a fuse layer capable of being disconnected reliably and providing a smaller blow trace.
Another object of the present invention is to miniaturize the semiconductor device.
A semiconductor device according to the present invention includes a first insulation layer, a plurality of fuse layers extending on the insulation layer in one direction and disconnected through light illumination to control a redundant circuit, a pseudo fuse layer provided on the first insulation layer along at least one side of the fuse layer, a second insulation layer formed to cover the fuse layers and the pseudo fuse layer, and a protection film formed on the second insulation layer and having an opening at a region opposite to the fuse layers. The fuse layers have a spacing of less than 4 μm or 4.5 μm to 5.5 μm.
In transferring an interconnection pattern for the fuse layers, the pseudo fuse layer thus provided allows any deformation in cross section of the interconnection pattern that would be otherwise caused at a surface of low interconnection density to be caused at the pseudo fuse layer rather than the fuse layers. Since the pseudo fuse layer is not disconnected through light illumination, there will not be any disadvantage caused if such a deformation of an interconnection pattern is caused at the pseudo fuse layer.
In the fuse layer disconnection, the fuse layers that are uniformed in cross section and have a spacing of less than 4 μm or 4.5 μm to 5.5 μm can allow for reliable disconnection of the fuse layers and uniform blow traces.
Preventing the enlargement of a blow trace of a fuse layer that is caused at a surface of low interconnection density, can reduce the dimensions of the opening provided in the production film formed on the second insulation film covering the fuse layers. As a result, the area required for the opening can be reduced and hence the semiconductor device can be miniaturized. The opening reduced in dimension renders it difficult for water and the like to enter the semiconductor device and can thus improve the water resistance of the semiconductor device.
The structure as described below is adopted so as to provide the present invention in more preferable condition.
The surface of the pseudo fuse layer opposite to that surface of the pseudo fuse layer which faces the fuse layers is inclined such that the pseudo fuse layer tapers upwards.
Since any deformation in an interconnection pattern for the fuse layers that would be otherwise caused at a surface of low interconnection density in transferring the interconnection pattern is caused at the pseudo fuse layer, the fuse layers can be uniform in cross section.
The fuse layers are each structured of at least two stacked layers, with a layer of a material with a relatively high boiling point provided as a surface layer. The pseudo fuse layer has the same structure as the fuse layers.
Still preferably, the fuse layers and the pseudo fuse layer are each formed of the three layers of a nitride layer, a metal layer and a nitride layer. The boiling point of the nitride layer is higher than that of a material for the metal layer. Such a structure allows the fuse layers to be patterned precisely.
Still preferably, the width of the pseudo fuse layer is equal to or smaller than that of the fuse layers. Furthermore, that sidewall of the opening provided in the protection film which is opposite to a side of the fuse layer is located between the surface of the fuse layer opposite to the pseudo fuse layer and the surface of the pseudo fuse layer opposite to the fuse layer.
Such a structure contemplates area reduction of the region required for the opening provided in the protection film formed on the second insulation layer covering the fuse layers and hence miniaturization of the semiconductor device.
The foregoing and other objects, features, aspects and advantages of the present invention will become more apparent from the following detailed description of the present invention when taken in conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a plan view of a semiconductor device with fuse layers in the background art.
FIG. 2 is a cross section taken along line A-A′ of FIG. 1 .
FIG. 3 is an enlarged partial cross section of a portion B shown in FIG. 2 .
FIG. 4 is an enlarged cross section of one fuse layer.
FIG. 5 is a plan view when laser light (linearly polarized) illuminates a fuse layer such that the laser light is polarized parallel to the fuse layer.
FIG. 6 is a cross section taken along line B-B′ of FIG. 5 .
FIG. 7 represents a light-intensity profile of laser light.
FIG. 8 is a cross section for illustrating a profile of heat emission when laser light (linearly polarized) illuminates a fuse layer such that the laser light is polarized parallel to the fuse layer.
FIG. 9 is a plan view showing a shape of a blow trace for parallel polarization.
FIG. 10 is a cross section for illustrating a profile of heat emission when laser light linearly polarized) illuminates a fuse layer such that the laser light is polarized perpendicular to the fuse layer.
FIG. 11 is a plan view showing a shape of a blow trace for circularly polarized light.
FIG. 12 (A) is a schematic diagram showing a geometrical relation between a fuse layer 3 and an incident angle of laser light 5 , and
FIG. 12 (B) is a graph of the reflectance of laser light 5 off an inclined surface 3 t versus an incident angle θ 2 .
FIG. 13 is a plan view of a semiconductor device with fuse layer 3 according to an embodiment of the present invention.
FIG. 14 is a cross section taken along line A-A′ of FIG. 13 .
FIG. 15 is an enlarged partial cross section of a portion E shown in FIG. 14 .
FIG. 16 is a plan view showing a shape of a blow trace in one embodiment.
FIG. 17 is a cross section showing a relation between a position of a side surface of an opening 6 a provided in a protection film 6 (denoted as L 2 in the figure) and a position of a fuse layer 3 side surface facing to a pseudo fuse layer 7 (denoted as L 1 in the figure).
FIG. 18 is a graph of the probability that a large hole is created (%) versus the spacing between fuse layers (μm).
FIG. 19 is a block diagram showing a schematic configuration of a Dynamic Random Access Memory (DRAM).
FIG. 20 is a cross section of a conventional fuse layer and a vicinity thereof.
FIGS. 21 and 22 are first and second cross sections showing how the conventional fuse layer is disconnected.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
A semiconductor device according to an embodiment of the present invention will now be described with reference to the drawings. The background art leading to the present invention will now be described in order to fully understand the structure of the semiconductor device according to the present embodiment.
The structure of the semiconductor device with a fuse layer will now be described with reference to FIGS. 1-4.
An oxide film 2 is formed on a semiconductor substrate 1 . On oxide film 2 is formed a plurality of fuse layers 3 having a predetermined profile in cross section. As shown in FIG. 3, fuse layer 3 is structured by the three layers of a nitride layer 3 a to prevent the ions of the silicon of semiconductor substrate 1 from diffusing into fuse layer 3 , a metal layer 3 b as an interconnection layer and a nitride layer 3 c serving as an anti-reflection film.
On fuse layers 3 is formed an insulation layer 4 covering fuse layers 3 . On insulation layer 4 is provided a protection film 6 provided with an opening 6 a located above fuse layers 3 .
Disconnection of fuse layer 3 will now be described with reference to FIG. 4 . Laser light 5 illuminates fuse layer 3 from above insulation layer 4 . Thus laser light 5 is absorbed by fuse layer 3 so that fuse layer 3 is heated. Consequently, fuse layer 3 changes in phase from solid to liquid to gas. Thus, the evaporation pressure of fuse layer 3 pushes insulation layer 4 upwards. When the evaporation pressure of fuse layer 3 exceeds a predetermined value, fuse layer 3 is disconnected and insulation layer 4 on fuse layer 3 is blown away to form a blow trace.
As has been described above, fuse layer 3 is often structured by three layers or multiple layers. This results in an uneven profile of the laser light absorbed by fuse layer 3 . Furthermore, the heat conduction resulting from the laser light absorption by fuse layer 3 is also complicated, since the film which forms a layer has a different physical property with respect to heat.
A relation between a direction of an electric field of laser light and a cross-sectional profile of a fuse layer will now be described with reference to FIGS. 5-11.
The surface of fuse layer 3 is covered with a material with a complex index of refraction m=n−i×k, wherein the square of a real-number term n minus the square of an imaginary-number term k (n 2 −k 2 ) has a negative value. Fuse layer 3 is adapted to have a rectangular cross-section.
Under the conditions provided as above, if the direction of the electric field of laser light 5 (linearly polarized) illuminating fuse layers 3 substantially corresponds to the longitudinal direction of fuse layer 3 (parallel polarization), as shown in FIGS. 5 and 6, such laser light 5 absorption is profiled that an edge (circled and labeled as C in the figure) of fuse layer 3 absorbs most of laser light 5 , as shown in FIG. 8 .
Since the light-absorption profile corresponds to heat-emission profile, the edge of fuse layer 3 reaches its boiling point in a short period of time and fuse layer 3 is thus disconnected. It should be noted that laser light 5 shown in FIG. 5 is adapted to have a beam diameter corresponding to a region of 1/e 2 in the laser-light intensity profile shown in FIG. 7 .
While the rapidly increased temperature allows fuse layer 3 to be disconnected, the time required for the disconnection of fuse layer 3 is approximately 10 ns, which is too short a period of time to soften a large portion of the surrounding oxide film through heat conduction. As a result, a blow trace 4 a created in insulation layer 4 that is associated with the disconnection of fuse layer 3 has a substantially rectangular profile, as shown in the plan view of FIG. 9 . This allows a reduced spacing between the fuse layer 3 interconnections and hence a reduced area of opening 6 a provided in protection film 6 .
When the direction of the electric field of laser light 5 (linearly polarized) illuminating fuse layer 3 is substantially orthogonal to the longitudinal direction of fuse layer 3 (orthogonal polarization), there is a laser light 5 absorption profile provided that is different from that for parallel polarization. More specifically, laser light 5 is absorbed at the upper and side surfaces of fuse layer 3 (i.e. the region denoted as D in the figure), as shown in FIG. 10 . The light-absorption profile corresponds to heat-emission profile and the temperature of fuse layer 3 is thus prevented from increasing only at a specific portion. Thus the temperature of fuse layer 3 increases gradually.
The gradual elevation of the temperature of fuse layer 3 expands that region of insulation layer 4 surrounding fuse layer 3 which is softened. As a result, blow trace 4 a created in insulation layer 4 that is associated with the disconnection of fuse layer 3 has a large, ellipsoidal profile, so that the spacing between fuse layer 3 interconnections and hence the area of opening 6 a provided in protection film 6 cannot be reduced.
It is thus preferable that the direction of the electric field of laser light 5 substantially correspond to or be polarized substantially parallel to the longitudinal direction of fuse layer 3 in irradiating fuse layer 3 with laser light 5 to disconnect fuse layer 3 .
While the parallel polarization allows the reduction in the spacing between fuse layer 3 interconnections and hence the reduction of the area of opening 6 a provided in protection film 6 , it is often difficult to irradiate all fuse layers 3 with laser light 5 through parallel polarization.
Accordingly, in practice, fuse layer 3 , which is dominantly formed of a material having a boiling point of less than 3000K, is illuminated and disconnected by laser light 5 through circular polarization in view of the fact that fuse layers 3 arranged in various directions have different longitudinal directions and of the rectangularity of blow trace 4 a , since circular polarization has characteristics intermediate between parallel polarization and orthogonal polarization.
The circularly polarized laser light 5 illuminating fuse layer 3 , however, causes the problem as described below. The profile of blow traces 4 a created when circularly polarized light is employed to disconnect fuse layers 3 varies, as shown in FIG. 11, even if fuse layers 3 are formed in the same opening 6 a . More specifically, a fuse layer 3 located at the center of opening 6 a has a substantially rectangular blow trace 4 a , whereas a fuse layer 3 located at an end of opening 6 a has a blow trace 4 a the profile of which is similar to an extremely large, half moon.
For example, when fuse layers 3 have a width of 1.0 μm and a spacing of 4 μm, blow trace 4 a protrudes from an end surface of fuse layer 3 by approximately 8 μm to 10 μm. Accordingly, a distance of at least 10 μm is required between the end surface of fuse layer 3 and the end of opening 6 a . This disadvantageously prevents reduction of the area of opening 6 a and hence miniaturization of the semiconductor device.
The following is the reason why blow trace 4 a of fuse layer 3 located at an end of opening 6 a has such a profile as described above.
It has been known as an empirical fact in the process for patterning fuse layer 3 that fuse layer 3 for a region of high interconnection density is patterned according to the transferred pattern, whereas fuse layer 3 for a region of low interconnection density is not patterned according to the transferred pattern and consequently an inclined surface 3 t is formed so that fuse layer 3 is gradually tapered upwards, as shown in the enlarged cross section in FIG. 3 .
A phenomenon caused when laser light 5 illuminates inclined surface 3 t of fuse layer 3 will also be described with reference to FIGS. 12A and 12B.
FIG. 12 (A) is a schematic diagram showing a geometrical relation between fuse layer 3 and an incident angle of laser light 5 , wherein an inclination θ 1 of inclined surface 3 t of fuse layer 3 is equal to an incident angle θ 2 of laser light 5 on inclined surface 3 t .
FIG. 12 (B) is a graph of the reflectance of laser light 5 off inclined surface 3 t versus incident angle θ 2 . For laser light 5 polarized horizontally, the reflectance increases as the value of incident angle θ 2 increases.
For laser light 5 polarized vertically, the reflectance decreases as the value of incident angle θ 2 increases. In particular, the reflectance significantly drops when incident angle θ 2 exceeds 60°, and the reflectance is minimized when incident angle θ 2 is approximately 80°. The reflectance for laser light 5 circularly polarized is similar in profile to that for laser light 5 vertically polarized, although smaller in variance.
Thus, when inclined surface 3 t is illuminated with laser light 5 circularly polarized, the temperature at the vicinity of inclined surface 3 t increases gradually and fuse laser 3 is thus disconnected, as is similar with laser light 5 polarized vertically.
The gentle temperature elevation expands that region of insulation layer 4 surrounding inclined surface 3 t which is softened. Thus, blow trace 4 a profiled like a half moon is created in insulation layer 4 surrounding inclined surface 3 t when fuse layer 3 is disconnected.
Based on the background art described above, the structure described hereinafter is applied to a semiconductor device according to an embodiment of the present invention. This structure will now be described with reference to FIGS. 13-15.
The semiconductor device according to the present embodiment has an oxide film 2 formed on a semiconductor substrate 1 . On oxide film 2 is formed a fuse layer 3 having a predetermined profile in cross section. Fuse layer 3 is configured of the three layers of a nitride layer 3 a to prevent the ions of the silicon of semiconductor substrate 1 from diffusing into fuse layer 3 , a metal layer 3 b as an interconnection layer, and a nitride layer 3 c serving as an anti-reflection film, as shown in FIG. 15 .
On fuse layer 3 is formed an insulation layer 4 covering fuse layer 3 . On insulation layer 4 is formed a protection film 6 having an opening 6 a located above fuse layer 3 .
A pseudo fuse layer 7 , which is not used for replacing a defective circuit with a redundant circuit, is provided in a region outside fuse layers 3 provided inside the same opening 6 a formed in protection film 6 .
Since pseudo fuse layer 7 is formed simultaneously in the process for patterning fuse layer 3 , pseudo fuse layer 7 has the same layered structure as that of fuse layer 3 . Since one side surface of pseudo fuse layer 7 faces a region of low interconnection density, inclined surface 3 t , which has been conventionally formed inevitably on fuse layer 3 , is formed as an inclined surface 7 t on pseudo fuse layer 7 , as shown in FIG. 15 .
Consequently, all of fuse layers 3 can have a same, symmetrical profile in cross section and thus a symmetrical profile of light absorption. Thus, blow traces 4 a can all have a rectangular profile, as shown in FIG. 16, and accordingly the spacing between fuse layers 3 can be reduced.
Since pseudo fuse layer 7 is not disconnected by laser light 5 , protection film 6 can be provided to cover pseudo fuse layer 7 . As shown in FIG. 17, the position of a side surface of opening 6 a provided in protection film 6 (i.e. L 2 in the figure) is only required to be closer to pseudo fuse layer 7 than the position of the fuse layer 3 side surface facing pseudo fuse layer 7 (i.e., Li in the figure) to pseudo fuse layer 7 .
Accordingly, the area of opening 6 a can be designed depending on fuse layer 3 rather than pseudo fuse layer 7 . Thus, the area of opening 6 a can be reduced and accordingly the semiconductor device can be miniaturized.
The area reduction of opening 6 a renders it difficult for water and the like to enter the semiconductor device so that the water resistance of the semiconductor device can be improved.
When fuse layer 3 is disconnected with pseudo fuse layer 7 provided as described above, however, blow trace 4 a has a round profile with a probability. For example, when the spacing between fuse layers 3 (denoted by P 1 in FIG. 16) is 6.5 μm, the probability that blow trace 4 a has a round profile, referred to the probability of large-hole creation hereinafter, is 0.65% without pseudo fuse layer 7 provided and 0.15% with pseudo fuse layer 7 provided. That is, the probability of large-hole creation with pseudo fuse layer 7 provided can only be approximately one fourth of that without pseudo fuse layer 7 provided.
FIG. 18 is a graph of the probability of large-hole creation (%) versus the spacing between fuse layers 3 (μm). As is apparent from the figure, the probability of large-hole creation can be reduced to approximately 0.025% when fuse layers 3 have a spacing of less than 4 μm, and it can be reduced to approximately 0.04% when fuse layers 3 have a spacing of 4.5 μm to 5.5 μm. Thus, it can be said that a preferable spacing between fuse layers 3 of the semiconductor device according to the present embodiment is less than 4 μm or 4.5 μm to 5.5 μm.
It should be noted that pseudo fuse layer 7 may or may not be connected to any circuits. Although pseudo fuse layer 7 and fuse layer 3 are same in film material in view of production efficiency, they may be different in film material as long as they are formed through the same patterning step.
Since pseudo fuse layer 7 does not function as fuse layer 3 , the width of pseudo fuse layer 7 may have any value larger than the limit of resolution in transferring the pattern therefor. Thus, the width of pseudo fuse layer 7 can be equal to all or less than that of fuse layer 3 .
While the above description has been provided with a DRAM as one example of the semiconductor devices to which fuse layer 3 and pseudo fuse layer 7 are applied, fuse layer 3 and pseudo fuse layer 7 are applicable to not only DRAMs but various semiconductor devices with a fuse layer, such as ERAMs.
Although the present invention has been described and illustrated in detail, it is clearly understood that the same is by way of illustration and example only and is not to be taken by way of limitation, the spirit and scope of the present invention being limited only by the terms of the appended claims.
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A semiconductor device includes: an insulation layer; a fuse layer extending on the insulation layer in one direction and disconnected through light radiation to control a redundant circuit; a pseudo fuse layer on the insulation layer along at least one side of the fuse layer; another insulation layer covering the fuse layer and the pseudo fuse layer; and a protection film formed on another insulation layer and having an opening in a region opposite to the fuse layer. Fuse layers having a spacing of less than 4 μm or 4.5 to 5.5 μm. Such a structure allows a semiconductor device with a fuse layer capable of being disconnected reliably and providing a smaller blow trace.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to the clutch, brake and gear arrangement of an automatic transmission for motor vehicles, particularly to such arrangements that combine planetary gear units and layshaft gearsets.
2. Prior Art
Four-speed automatic transmissions conventionally include multiple planetary gearsets; five or six friction elements, such as hydraulically actuated clutches and brakes; a torque converter; and damped torque converter lock-up clutch. These transmissions are employed in rear-wheel drive vehicles wherein the transmission shafts and engine crankshaft are parallel to the longitudinal axis of the vehicle, and front-wheel drive vehicles wherein the transaxle and engine crankshaft are parallel to the transverse axis of the vehicle.
A current trend in the automotive industry is to provide five-speed and six-speed automatic transmissions, which conventionally require three planetary gear units and even a larger number of friction elements to control the gearing than are required in four-speed transmissions. Automatic transmissions having five or six forward speed ratios require greater size, particularly increased length, to accommodate additional planetary gear unit and friction elements. Furthermore, automatic transmissions require nonsynchronous gearshifting, which conventionally require still greater use of one-way couplings and more space within the transmission casing, particularly space in the direction of the transmission's length.
These trends toward features that enhance performance of automatic transmissions have produced need for an extremely compact transmission suitable for use in a front-wheel drive vehicle and able to fit in a space that is greatly reduced in comparison to the space required for conventional five-speed or six-speed automatic transmissions. Front-wheel drive vehicles present particularly acute problems because of the inherent space limitation associated with packaging the transmission and engine with their axes directed transversely between the drive wheels of the vehicle.
U.S. Pat. No. 5,106,352 describes a multiple speed automatic transmission having two gearsets comprising constant mesh gear wheels, a double planetary gearset, and first and second control brakes. The transmission is able to provide six forward speeds, brake neutral and reverse drive.
SUMMARY OF THE INVENTION
It is an object of this invention to provide a multiple speed automatic transmission in a highly compact form requiring a minimal number of friction element to control operation of the components of the gear units and gearsets that produce the various speed ratios. The transmission is suitable for use in nonsynchronous and synchronous modes of operation. One version of the transmission provides nonsynchronous sequential upshifts and downshifts and nonsynchronous jump shifts, in which a gear ratio change is made between nonsequential gear ratios.
A transmission according to this invention includes a combination of planetary gear units and conventional layshaft gearsets, the gear units and gearsets being arranged such that elements of the gear units are driven from the input shaft through the layshaft gearsets at two different speed ratios.
An advantage of the gear arrangement according to this invention is its compact size, particularly the reduction in overall length of the transmission and the gear box required to contain the transmission. An additional advantage is the low number of hydraulically actuated friction elements required to control the transmission gear elements.
In realizing these advantages and objectives a transmission according to the present invention includes an underdrive gearset and an overdrive gearset driveably connected to an input shaft and elements of first and second planetary gear units. Each planetary gear unit includes a sun gear, ring gear, pinions meshing with the sun gear and ring gear, and carrier rotatably supporting the pinions. The sun gear of the first gear unit, carrier of the second gear unit and one of the gearsets are mutually driveably connected. The carrier of the first gear unit, ring gear of the second gear unit and output shaft are mutually driveably connected. The control elements of the transmission hold the sun gear of the first gear unit and components connected to that sun gear against rotation on the transmission casing. A first friction clutch releasably connects the input shaft to one of the gearsets; a second friction clutch releasably connects the input shaft to the other of the gearsets. Two additional friction clutches releasably connect the ring gear of the first gear unit to one of the gearsets and the sun gear of the second gear unit to one of the gearsets.
A six-speed version of the transmission includes a second friction brake adapted to hold one of the gearsets against rotation on the transmission casing. A transmission according to the invention that produces five forward speed ratios, reverse drive and first speed ratio in a manually selected range requires only four hydraulically actuated friction clutches, a friction brake band and overrunning coupling. Six forward speed ratios, reverse drive and first speed ratio in a manually selected range are produced in a transmission according to this invention through operation of only four hydraulically actuated friction clutches, two friction brakes and one overrunning coupling.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic diagram showing an arrangement of gearing, couplings, clutches and brakes for a transmission acceding to the invention.
FIG. 2 is a schedule showing the engaged and disengaged state of the clutches, brake and coupling of FIG. 1 corresponding to the various gear ratios produced by the transmission.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring first to FIG. 1, an engine crankshaft 10 is driveably connected to a bladed impeller 12 of a hydrokinetic torque converter 14, which further includes a bladed turbine 16 and bladed stator 18. The impeller, turbine, and stator define a toroidal flow path, in which hydraulic fluid circulates, thereby producing a hydrokinetic drive connection between the impeller and turbine. The stator is mounted on a stator shaft through an overrunning coupling 22, which produces a one-way drive connection between the stator rotor and casing 20. A torque converter bypass clutch 24, an hydraulically-actuated friction element, is engaged to driveably connect crankshaft 10 to a transmission input shaft 26 and is released to connect the crankshaft and input shaft through torque converter 14.
Input shaft 26 is fixed to a pinion 36 of a first gearset 38, and it is releasably connected to a pinion 40 of a second gearset 42 by an hydraulically-actuated friction clutch 44, which is engaged and disengaged in accordance with the schedule of FIG. 2. Pinion 40, which is supported rotatably on shaft 26, is in continual meshing engagement with gear 46 of the second gearset.
A first gearset 38 includes a pinion 36, fixed to input shaft 26, and a gear 48, which is in continual meshing engagement with pinion 36.
Shaft 26 drives an hydraulic pump, which is supplied with hydraulic fluid from a sump. The pump outlet side is connected to an hydraulic control and actuation circuit, through which the torque converter 14 is continually supplied with a source of pressurized hydraulic fluid. Bypass clutch 24, one of a number of hydraulically-actuated friction elements, i.e., clutches and brakes, is engaged by the effect of pressurizing fluid carried to the bypass clutch and is disengaged by venting the bypass clutch pressure source.
A first simple planetary gear unit 50 includes sun gear 52, ring gear 54, carrier 56, and a set of planetary pinions 58, rotatably supported on carrier 56 and in continuous meshing engagement with ring gear 54 and sun gear 52.
A second simple planetary gear unit 60 includes sun gear 62, ring gear 64, carrier 66 and a set of planetary pinions 68, supported rotatably on carrier 66 and in continuous meshing engagement with sun gear 67 and ring gear 64.
Sun gear 52 is driveably connected to gear 48. Ring gear 64, carrier 56, and output shaft 70 are mutually driveably connected.
Final drive gearing, in continual meshing engagement with output shaft 70, drives the spindle of an axle differential mechanism located between axleshafts (not shown), while transmitting power to the drive wheels of the vehicle.
Input shaft 26 is releasably connected through clutch 44, a hydraulically-actuated friction clutch, to pinion 40 of the second gearset 42. Pinion 46 of the second gearset is driveably connected by member 72 to carrier 66 of the second planetary gear unit 60. Brake 74, a hydraulically-actuated friction brake, produces a releasable connection between the transmission casing 20 and pinion 40, whereby gear 46, member 72, and carrier 66 are selectively held against rotation on the transmission casing.
Clutch 76, another hydraulically-actuated friction clutch, releasably connects gear 46 and ring gear 54 of the first planetary gear unit 50.
Clutch 78, an hydraulically-actuated friction clutch, releasably connects gear 48 of the first gear set 38 and sun gear 62 of the second planetary gear unit 60, which is connected to the clutch 78 by a disc member 80. Sun gear 62 and disc 80 are held against engagement on the transmission casing 20 by engaging second brake 82.
The first gearset 38 has a gear ratio of 1.3; therefore, sun gear 52 turns slower than input shaft 26. The second gearset 42 has a gear ratio of 0,810; therefore, carrier 66 rotates faster than the input shaft.
The first forward speed ratio is produced by engaging clutch 76 and brake 74 and by disengaging the other clutches and brake. Brake 74 holds the second gear set 42, member 72, and carrier 66 fixed against rotation. Clutch 76 completes the connection of ring gear 54 to member 72; therefore, gear 54 is also held against rotation. The first gearset drives ring gear 52 slower than input shaft 26, the gearset reaction is at ring gear 54, and the output is taken at carrier 56 and output shaft 70.
The second forward speed ratio results by maintaining clutch 76, disengaging brake 74 and engaging brake 82. Brake 82 provides the gearset reaction by holding sun gear 62 fixed against rotation. Clutch 82 driveably connects carrier 66 and ring gear 54. Sun gear 52 is driven through the first gearset 38 at a speed faster than that of the input shaft and output shaft 70 is driven by carrier 56, which rotates at the same speed as ring gear 64.
A third forward speed ratio results when clutches 76 and 78 are engaged and the other friction elements are disengaged. In this condition, carrier 66 is driveably connected by clutch 76 to ring gear 54. The input shaft drives sun gear 52 through the first gearset 38 and sun gear 62 through clutch 78. Output shaft 70 is driven by the carrier 56, which is directly connected to ring gear 64.
The fourth forward speed ratio results when clutches 76 and 44 are engaged and the other friction elements are disengaged. Accordingly, sun gear 52 is underdriven in relation to the speed of input shaft 26, and carrier 66 and ring gear 54, which are interconnected through operation of clutch 76, are overdriven in relation to the speed of the input shaft. The output is taken at carrier 56 and output shaft 70.
When clutches 44 and 78 are engaged and the other friction elements disengaged, a fifth forward speed ratio is produced. Clutch 78 and sun gear 52 of the first planetary gear unit is underdriven due to its connection to gear 48 of the first gearset 38, and sun gear 62 is driven at the same speed as sun gear 52 due to the connection to gear 48 through engagement of clutch 78. Carrier 66 is overdriven in relation to the speed of input shaft 26 through operation of the second gearset 42 and the connection that exists between gear 46, member 72. The driven members of the second planetary gear unit 60, viz., sun gear 62 and carrier 66, operate to drive ring gear 64, carrier 56, and output shaft 70.
The sixth forward speed ratio results by engaging brake 82 and clutch 44 and disengaging the other friction elements. Sun gear 62 is held against rotation on the transmission casing 20 through disc 80 and the drivable connection made by engagement of brake 82 to the transmission casing. The driving member of the second planetary gear unit 60, carrier 66, is overdriven in relation to the speed of input shaft 26 through operation of the second gear unit 42. The driven element, ring gear 64, drives the output, carrier 56, and output shaft 70.
To produce reverse drive, clutch 78 and brake 74 are engaged and the other friction elements are disengaged. Due to the drive connection produced by clutch 78, sun gear 62 is underdriven from input shaft 26 through operation of first gearset 38. Carrier 66 is fixed on housing 20 against rotation due to the engagement of brake 74, and the output is taken at ring gear 64, carrier 56, and output shaft 70.
Nonsynchronous 1-2 and 2-1 gearshifts are produced by installing an overrunning coupling 90 between the transmission housing and input shaft 26. Coupling 90, which produces a one-way drive connection between the housing and shaft 26, includes a hub 92 fixed to the shaft, a ring 94 fixed to the housing, rollers 96 located between the ring and hub and mutually spaced about the coupling axis, the rollers engaging a cam surface on the ring or hub to connect driveably the ring and hub in one direction of rotation, and disengaging the cam surface to disconnect the ring and hub in the opposite direction of rotation. FIG. 1 shows the coupling located between brake 74 and pinion 40.
The first gear ratio can be produced also through operation of coupling 90 by engaging clutch 76 and disengaging the other friction elements, including brake 74. Gearset 38 drives sun gear 52 from shaft 26. The gearset reaction is provided at ring gear 54, which is held fixed against rotation on the housing due to the one-way drive connection between the shaft 26 and the housing produced by coupling 90. The output is taken at carrier 56 and shaft 70.
To produce the other forward and reverse gear ratios, either coupling 90 overruns or (as in the case of reverse drive) brake 74 is engaged to connect shaft 26 to the housing, rather than producing that connection through coupling 90.
This arrangement produces a compact transaxle for use in front wheel drive vehicles having a combination of lay shaft gearsets and planetary gear units. The transaxle produces six forward speed ratios and reverse drive through operation of only five friction elements.
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An automatic transmission for an automotive vehicle includes first and second simple planetary gear units, certain of whose elements are continually interconnected and certain others are releasably connected through operation of five friction elements, hydraulically-actuated clutches and brakes. The input shaft of the transmission drives elements of the planetary gear units through an underdrive gearset and an overdrive gearset. Various speed ratios result by either underdriving or overdriving a driven element of the planetary gear unit or both underdriving one element and overdriving another element.
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FIELD
[0001] This application relates generally to horticulture implements. More particularly, this application relates to sprouters for growing and harvesting sprouts and methods of using sprouters.
BACKGROUND
[0002] Seed sprouting is the practice of germinating seeds into sprouts that may be eaten raw or cooked. Some common varieties of sprouts grown and eaten including alfalfa, mung bean, broccoli, watercress, wheat berry, soybean, and clover. Because various health benefits that have been identified with eating sprouts, many people have become interested in home-based seed sprouting, in which individuals can grow sprouts at home. In conventional, home-based seed sprouting, seeds are placed in a first container, such as a jar. Before the seeds sprout, they are kept wet by soaking and/or periodically rinsing the seeds within the container. After the seeds begin to the sprout, the sprouts are kept moist, but should not be kept overly moist or wet, which may stunt or stop sprout growth. During this growth phase, the sprouted seeds are placed in a second container, such as a tray, where the sprouts can grow in an open environment until harvested.
[0000] Because these conventional, home-based seed sprouting practices required proper watering and timely transport of the seeds between separate containers, individuals can make mistakes in caring for the sprouts, which result in low crop yields or crop failure. Accordingly, it would be beneficial to improve sprouting techniques and systems to minimize the labor and accuracy required to produce optimal seed sprout harvests.
SUMMARY
[0003] Devices for growing sprouts, also known as sprouters, and methods for using sprouters are taught in this document. Exemplary sprouters may include at least one tray or a plurality of trays configured to stack vertically. The trays may be formed from a hydrophobic material. They trays may each include a side wall and a bottom surface, the bottom surface having a plurality of openings. The sprouter may include a lid configured to cover the open top of one of the plurality of trays and a collection tray configured to collect water from the plurality of trays.
[0004] In some embodiments, the plurality of openings may be in fluid communication with the collection tray. The bottom surface may include at least one raised feature and the plurality of openings may extend through the bottom surface and the at least one raised feature. The bottom surface and the side wall may define a volume having an open top. The side wall may be translucent.
[0005] The hydrophobic material may be polypropylene and the plurality of openings each having a diameter of about 1/16″. The sprouter may be configured to automatically adjust the maximum water levels in the at least one tray depending on whether seeds in the tray are germinated and growing or soaking.
[0006] Exemplary sprouters may be used by performing a number of steps, including: placing seeds in at least one tray; placing the at least one tray on a collection tray; pouring water in the at least one tray; providing holes in the at least one tray; providing a maximum water level in the at least one tray for soaking seeds; automatically adjusting the maximum water level when the seeds germinate; and collecting water in excess of the maximum water level in the collection tray.
[0007] In some embodiments, the at least one tray may be a plurality of trays, and further include the step of stacking the plurality of trays vertically, wherein water from a top tray in the vertical stack supplies the others of the plurality of trays through the holes in the top tray. The top tray may be covered with a lid. Water may be supplied to the plurality of trays by pouring water in the top tray.
[0008] In other embodiments, the at least one tray may be formed from a hydrophobic material and the holes in the at least one tray may be sized such that the surface tension of pure water and the hydrophobic properties of the tray material resists passage of the pure water through the holes. The automatically adjusting may be facilitated by germinating seeds soaking in water changing the surface tension of the soaking water and reducing the resistance to passage through the holes. The seeds are placed on and around the raised features. Water in the collection tray is used in the step of pouring water.
BRIEF DESCRIPTION OF THE DRAWINGS
[0009] The following description can be better understood in light of the Figures, in which:
[0010] FIG. 1 shows a perspective view of some embodiments of an exemplary sprouter having multiple trays;
[0011] FIG. 2 shows a perspective view of some embodiments of an exemplary sprouter having multiple trays with transparent sidewalls;
[0012] FIG. 3 shows a perspective view of some embodiments of an exemplary tray for use with a sprouter;
[0013] FIG. 4 shows a top view of some embodiments of the tray shown in FIG. 3 ;
[0014] FIG. 5 shows a bottom view of some embodiments of the tray shown in FIG. 3 ;
[0015] FIG. 6 shows a cross section view of some embodiments of an exemplary sprouter having multiple trays containing growing sprouts;
[0016] FIG. 7 a shows a cross section view of some embodiments of an exemplary tray containing seeds that are unsprouted;
[0017] FIG. 7 b shows a cross section view of some embodiments of the tray shown in FIG. 4 a containing seeds that are germinated;
[0018] FIG. 7 c shows a cross section view of some embodiments of the tray shown in FIGS. 7 a and 7 b containing seeds that are sprouted and growing; and
[0019] FIG. 8 shows a flowchart of some embodiments of a method of growing seed sprouts in the sprouter.
[0020] The Figures illustrate specific aspects of exemplary sprouters and methods for making such devices. Together with the following description, the Figures demonstrate and explain the principles of the methods and structures produced through these methods. Some dimensions and thicknesses may be exaggerated for illustration purposes. The same reference numerals in different drawings represent the same element, and thus their descriptions will not be repeated.
DETAILED DESCRIPTION
[0021] The following description supplies specific details in order to provide a thorough understanding. Nevertheless, the skilled artisan would understand that the sprouter and associated methods of making and using the sprouter can be implemented and used without employing these specific details. Indeed, the sprouter and associated methods can be placed into practice by modifying the illustrated devices and methods and can be used in conjunction with any other apparatus and techniques conventionally used in the industry.
[0022] Some embodiments of a sprouter 100 and methods for using such are shown in FIGS. 1-8 . The sprouter 100 , as shown in FIG. 1 , may generally include one or more growth trays 110 , a collection tray 160 , and a lid 140 . Some embodiments may include a single growth tray 110 , while other embodiments may include multiple growth trays 110 , such as 3, 5, 10, 15, or more than 15 growth trays 110 . Each of growth trays 110 can be stacked vertically on top each other and on top of the collection tray 160 , and the lid 140 can be placed on top of the topmost growth tray 110 . In use, seeds 132 can be placed within each growth tray 110 and left there during the entire growth process, from soaking to harvesting. Thus, there may be no need to move germinated or sprouted seeds between multiple containers, as is required in some conventional seed sprouting techniques. This can simplify the process of growing seed sprouts and also reduce the likelihood of damaging the sprouted or germinated seeds while transporting them from one container to another or forgetting to transport the seeds at the proper time. Moreover, by vertically stacking the growth trays 110 , as shown, a user can efficiently utilize available space for growing sprouts.
[0023] In some embodiments, each of the growth trays 110 may be stackable, such that multiple growth trays 110 can be stacked vertically on top of one another to form the body of the sprouter 100 . In some configurations, the bottom portion of each growth tray 110 can be slidably received into a top opening of a lower growth tray 110 when stacked to stabilize the stack of growth trays 110 . In some configurations, the interface 118 between adjacent growth trays 110 can further or alternatively include an interlocking feature that selectively locks adjacent growth trays 110 together to prevent the unintentional removal of one growth tray 110 from another. In use, each of the one or more growth trays 110 can be selectively lifted off of a lower growth tray 110 or the collection tray 160 so that a user can access the contents of the lower tray.
[0024] In some embodiments, the collection tray 160 may form the base of the sprouter 100 and collect water that seeps downwards through the one or more growth trays 110 . Accordingly, the collection tray 160 can be shaped and configured to form a dish or other semi-enclosed container that can retail a liquid therein. In some configurations, the collection tray 160 that has no holes except for a top opening into which is inserted the bottom side of a growth tray 110 . In other configurations, the collection tray 160 may include one or more polls disposed on a side portion of the collection tray 160 that forms an outlet for water when the collection tray 160 is filled or nearly filled with water. The collection tray 160 can be sized to collect various quantities of water, such as between about 1 cup of water and about 10 cups of water, between about 2 cups of water and about 4 cups of water, or more than about 10 cups of water. In some configurations, the collection tray 160 can have substantially the same shape and size as the one or more growth trays 110 .
[0025] In some embodiments, a lid 140 may be placed on the top of topmost growth tray 110 to cover the opening of the topmost growth tray 110 . The lid can form a solid barrier between the topmost growth tray 110 can assist to retain moisture and odors within the sprouter 100 . In some configurations, this barrier may be airtight, while in other embodiments this barrier can permit air to flow therethrough. The lid 140 can be removable so that a user can access the contents of the topmost growth tray 110 . In other embodiments, a lid 140 may not be included with the sprouter 110 .
[0026] Referring still to FIG. 1 , in some configurations, the combination of the lid 140 , one or more of the growth trays 110 , and the collection tray 160 may form a substantially enclosed container. Moreover, in some embodiments, there may be no substantial openings or air holes between the interior of the growth trays 110 and the external environment when the one or more growth trays 110 are properly stacked and the lid 140 is properly positioned. In other embodiments, one or more air holes may be placed in the lid 140 , the one or more growth trays 110 , and/or the collection tray 160 .
[0027] In some embodiments, one or more of the lid 140 , the one or more growth trays 110 , and/or the collection tray 160 may be made of a durable, water-proof material. Non-limiting examples of materials that can be used to manufacture these parts of the sprouter 100 may include glass, ceramics, composite materials, and other suitable materials. In some instances, these parts can be made of a thermoplastic polymer such as polypropylene, polyethylene, polyvinyl chloride, or other suitable material. In some embodiments, the growth trays 110 may be formed of or coated with a material that is hydrophobic in nature, such as PTFE, polypropylene, poly (ether imide), poly (vinylidene fluoride) and polysulfones or other suitable materials. In some configurations, the lid 140 , the one or more growth trays 110 , and/or the collection tray 160 are formed at least partially in an injection molding, vacuum forming, hydroforming, or other suitable process.
[0028] The sprouter 100 can have various shapes and sizes. As shown in FIG. 1 , in some embodiments, the sprouter 100 may have a cylindrical shape, such that each of the growth trays 110 , the collection tray 160 , and the lid 140 may have a circular horizontal cross-section. In other embodiments, these parts may have a non-circular cross-section, such as a square cross-section or a cross-section having the shape of another polygon. The sprouter 100 can be made to have various heights that depend in part on the number and size of each individual growth tray 110 and the collection tray 160 . In some configurations, the height of each individual growth tray 110 may be between about 1 inch and about 4 inches, between about 1.5 inches and about 3 inches, or between about 1.5 inches and about 2.5 inches. In some configurations, the length, width, and/or circumference of each individual growth tray 110 may be between about 2 inches and about 24 inches, between about 3 inches and about 12 inches, or between about 4 inches and about 8 inches.
[0029] FIG. 2 shows some embodiments of the sprouter 100 with one or more growth trays 110 made of a transparent or semi-transparent material. Such material can permit light to enter into each tray as may be beneficial for at least some of the phases of sprout growth. As shown, these materials may allow the bottom surface of each growth tray 110 to be seen through the sidewall of each growth tray 110 . As shown, in some configurations, the bottom surfaces of each growth tray 110 may include a textured surface or a pattern of raised ribs whereon seeds can be placed, sprouted, and grown to maturity. FIG. 6 shows some embodiments of a growth tray 110 that may include a floor 120 and sidewalls 112 . In some embodiments, one or more raised ribs 124 may extend upwards from the floor 120 of the growth tray 110 . The raised ribs 124 can be disposed in a predetermined pattern, such as the illustrated circular-type pattern. The raised ribs 124 can be disposed in other such patterns such as straight rows or in rows that extend from center of the floor 120 to near the sidewall(s) 112 . In other embodiments, the floor 120 may include a textured surface rather than raised ribs 124 . In some configurations, the raised ribs 124 can extend upwards between about 1/32 of an inch to about ⅛ of an inch. The raised ribs 124 or textured surface can reduce the amount of water required within the bottom surface of the growth tray 110 .
[0030] As shown in FIG. 3 , in some configurations, the one or more holes 122 in the floor 120 of the growth tray 110 may be formed through a raised rib 124 or other raised structure. The height of the raised rib(s) 124 or other raise structures can be selected so that the height of the water level 174 is configured to be retained at a predetermined height after water has stopped draining from the one or more holes 122 , as described above. Accordingly, even if the water within the growth tray 110 were to completely drain out of the holes 122 down to the level of the raised rib 124 , there would still be water between the floor 120 and the top of the raised trip 124 within the growth tray 110 , which could keep the seeds moist. Accordingly, in some embodiments, the height of the raised ribs 124 is selected based upon the desired water level 174 within the growth tray 110 after water has stopped draining from the one or more holes 122 .
[0031] FIG. 4 shows a top view of the growth tray 110 of FIG. 3 . This Figure depicts the circular-type pattern of the raised ribs 124 on the floor 120 of the growth tray 110 . As shown, in some embodiments, one or more channels 126 can be formed through the pattern of the raised ribs 124 to facilitate fluid flow along the floor 120 of the growth tray 110 . These channels 126 can ensure the water is substantially evenly distributed among the seeds or sprouts within the growth tray 110 . As further shown, in some configurations, the one or more holes 122 can be formed through a raised rib 124 that is wider than the diameter of the one or more holes 122 . In the embodiments shown in FIG. 7 , the growth tray 110 includes sixteen holes. In other embodiments, the growth tray 110 can include more than sixteen holes for fewer than sixteen holes depending on the size of the growth tray 110 and size of the holes 122 .
[0032] FIG. 5 shows a bottom view of the growth tray 110 FIGS. 3 and 4 . As shown, in some embodiments, the holes 122 extend completely through the floor 120 of the growth tray 110 . The floor of the growth tray 110 may also form a substantially flat and enclosed surface that can be inserted into the top of a lower growth tray 110 when stacked, as shown in FIG. 1 .
[0033] FIG. 6 shows some embodiments of a sprouter 100 having four growth trays 110 stacked vertical upon a collection tray 160 . Each growth tray 110 can include a floor 120 upon which seeds can be placed and one or more sidewalls 112 that can extend in a substantially vertical direction from the floor 120 . The bottom portion of each growth tray 110 can include an inward-oriented ledge 118 that can be compatibly inserted into the top portion of an adjacent, lower growth tray 110 . The inward-oriented ledge 118 can have outer dimensions that approximate the inner dimensions of the top portion of an adjacent, lower growth tray 110 such that the inwardly-oriented ledge 118 can be inserted within the adjacent growth tray 110 without excess space therebetween. In embodiments where growth tray 110 includes a circular, horizontal cross section, the inwardly-oriented ledge 118 can also include a circular, horizontal cross section having a smaller, outer diameter than the outer diameter of the main portion of the growth tray 110 . In some configurations, the outer diameter of the inwardly-oriented ledge 118 may approximate the inner diameter of the opening of the growth tray 110 .
[0034] In order to provide water to the seeds and sprouts 130 growing within each growth tray 110 , one or more holes 122 can be formed through the floor 120 of each growth tray 110 . The holes 122 may be formed within an outer ring of the raised ribs 124 to provide a residual amount of water that will remain in the growth tray 110 . In some instances, as water 172 is poured into the top growth tray 110 , it trickles down through the one or more holes 122 to the growth tray 110 below it. This trickling process continues until any excess water 172 is collected in the collection tray 160 . Accordingly, a user may water the seeds 132 or sprouts 138 by adding an adequate amount water into the top growth tray 110 , which then trickles down into each of the lower growth trays 110 through the holes 122 .
[0035] Referring still to FIG. 6 , in some embodiments, the material used to form the one or more growth trays 110 and the size of the one or more holes 122 may be selected so that the surface tension between the one or more holes 122 and the water 172 is large enough that some water 172 is retained within each tray after each watering. When the height of the water level 174 is above a certain height, the water pressure will be greater than the surface tension at the holes 122 , causing some of the water 172 to pass through the holes 122 . Once the water level 174 is below a certain height, the surface tension pressure at the holes 122 is less than the pressure and no more water flows. As such, proper selection of an appropriately hydrophobic material and correct sizing of the holes 122 can allow the correct amount of water to be automatically retained within each growth tray 110 , which can minimize the watering accuracy required for users to accurately water the seeds or sprouts 130 . In these instances, some water will be retained within each of the growth trays 110 . Accordingly, by adjusting the size of the one or more holes 122 in the growth trays 110 or by using materials with different hydrophobic properties, the height of the water level 174 retained within each growth tray 110 can be adjusted.
[0036] For example, in some configurations, the height of the water level 174 retained in the growth trays 110 after water 172 has stopped draining therefrom, when there are no germinated or sprouted seeds within the growth trays 110 , is about ¼″ to about 3/16″. In other configurations, this height may be about 1/16″ to about ⅛″. Moreover, in some embodiments, the size of the holes 122 that may provide the above-listed water levels 174 can be from about 1/64″ to about ⅛″. In some embodiments, the size of the one or more holes is about 1/16″.
[0037] Some different stages of growing sprouts 130 from seeds 132 using the sprouter 100 are shown in FIGS. 7 a to 7 c . To grow sprouts 130 within the growth tray 110 , the desired seeds 132 may be placed on the bottom surface 120 of the growth tray 110 . Some common varieties of seeds including alfalfa, mung bean, broccoli, watercress, wheat berry, soybean, and clover may be grown in the sprouter 110 . To initiate growth, the seeds 132 are soaked in water. Generally, the seeds 132 may need to be soaked for approximately one to three days or possibly longer until germination. Accordingly, as mentioned above, the size of one or more holes 122 in the growth tray 110 and the material used to form the growth tray 110 are selected such that the one or more holes 122 stops draining water when the water level 174 reaches a predetermined height. In this way, each growth tray 110 can retain enough water to properly soak the seeds 132 until germination. In some configurations, the one or more holes 122 and the growth tray 110 are configured such that the water level water level is about ¼″ to about ⅜″ of an inch when un-germinated seeds are contained within the growth tray 110 .
[0038] FIG. 7 b shows the growth tray 110 and seeds 132 of FIG. 4 a after the seeds 132 begin to germinate and sprout. It has been recognized, that when seeds 130 begin to germinate they release one or more enzymes into the water 172 within the growth tray 110 which can affect the surface tension of the water 172 , which consequently affects the force required to push the water 172 through the holes 122 . These enzymes have been observed to decrease the surface tension of the water 174 , which subsequently can reduce the height of the water level 174 within the tray. Advantageously, at the same time the seeds 132 begin to germinate and release these enzymes, the seeds 132 are no longer required to be soaked in water 172 . At this point, the seeds 132 are beginning to sprout and entered a growth stage in which they may require a lower water level 174 in order to be kept moist for optimal growth. Accordingly, in some configurations, the one or more holes 122 and the growth tray 110 may be configured such that the water level may be maintained at about 1/32″ to about 3/16″ when germinated seeds release one or more enzymes into the water 172 .
[0039] FIG. 7 c shows the growth tray 110 of FIGS. 7 a and 7 b after the seeds 132 have grown into mature sprouts 130 . At this point, the sprouts 130 can be harvested and eaten or cooked. Between the period of seed sprouting and sprout harvesting, the sprouts should be kept moist, but should not be overwatered, which may stunt or prohibit growth. During growth, the seeds 132 and/or the growing sprouts 130 may continue to release one or more enzymes that affect the surface tension between the one or more holes 122 and the water 172 within the growth tray 110 . Accordingly, during sprout growth, the height of the water level 172 may be lower than the height of the water level 172 present in the growth tray 110 during seed soaking. Accordingly, as shown, water may be placed periodically into the one or more growth trays 110 , particularly into the top tray. For example, sprouts may be watered with about ½ cup two times per day while they are growing. As previously described, as water may only need to be placed into the topmost growth tray 110 , from which the water can drain through the one or more holes 122 into any lower growth trays 110 , and finally into the reservoir 170 of the bottom tray 160 .
[0040] FIG. 8 shows a flowchart of a method 200 for growing sprouts within sprouter. In step 202 , seeds may be placed within the one or more growth trays of the sprouter. For effective growth, the seeds 132 may be evenly spread across the bottom surface of the one or more growth trays. When more than one growth tray is used, the growth trays can be stacked on top of each other and on top of a collection tray. In step 204 , water may be added to the top growth tray of the sprouter. Water may be added until each growth tray includes an adequate amount of water and stops draining excess water. In some instances, such as when sprouter includes between about one to about four growth trays, a half of a cup of water may be all that is required to be placed into the top growth tray two times per day. If the sprouter includes more than four growth trays, more than about a half of a cup water may be needed.
[0041] In step 206 , the user may continue water this seeds regularly, noting that after this seeds sprout, the growth trays will automatically retain less water. In step 208 , the user removes excess water from the reservoir 170 from the collection tray 160 before the collection tray 160 becomes full. Lastly, in step 210 , the user may harvest the sprouts 130 when the sprouts 130 reach maturity. The period from seed sprouting to maturity will be based on the type of seed and the environmental conditions, and they generally take between about a couple of days to about several weeks. In some instances, the method 200 further includes removing and replacing the lid each time water is added to the sprouter. It has been observed, that the act of opening the lid twice a day may provide enough oxygen to the sprouts for adequate sprout grow.
[0042] In addition to any previously indicated modification, numerous other variations and alternative arrangements may be devised by those skilled in the art without departing from the spirit and scope of this description, and appended claims are intended to cover such modifications and arrangements. Thus, while the information has been described above with particularity and detail in connection with what is presently deemed to be the most practical and preferred aspects, it will be apparent to those of ordinary skill in the art that numerous modifications, including, but not limited to, form, function, manner of operation and use may be made without departing from the principles and concepts set forth herein. Also, as used herein, examples are meant to be illustrative only and should not be construed to be limiting in any manner.
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Exemplary sprouters may provide automatic water level adjustment for soaking seeds and growing sprouts from those seeds in trays formed from a hydrophobic material and with holes in the bottom surface of the tray sized such that the surface tension of pure water and the hydrophobic properties of the tray material resists passage of the pure water through the holes. The automatically adjusting may be facilitated by germinating seeds soaking in water changing the surface tension of the soaking water and reducing the resistance to passage through the holes.
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BACKGROUND OF THE INVENTION
The present invention relates to an arrangement for enhancing the cooling capacity of portable personal computers. More particularly, the invention is directed to the provision of an arrangement for increasing the cooling capacity of portable personal computers, particularly such as laptop or notebook computers. The computer possesses a keyboard having the rear edge thereof hingedly connected with the bottom of an openable display unit or panel, and containing heat-generating computer electronics, from which heat is removed through a heat pipe terminating in a coupling arrangement possessing elements which connect to and disconnect from each other when, respectively, docking and undocking the portable personal computer in a docking station so as to facilitate the transference of heat from the portable personal computer through the coupling arrangement into the docking station from whence the heat is dissipated to the surroundings through the intermediary of a heat sink.
Commencing from the time of conception and design development of computers, and especially portable personal computers; for instance such as laptop computers or the like, there has been encountered the aspect of thermal management as a result of heat which is generated by the processor and other electronic components of the computer. As is widely known in the computer technology, excessive amounts of heat can readily degrade the performance of computers, and additionally may cause the components of the computers to be damaged. Consequently, thermal management is frequently considered to be an extremely important aspect in the design and development of computers.
The capacity and performance of portable personal computers, such as laptop computers, notebook computers or the like, has recently been enhanced to such an extent that; for example, since the beginning of 1996, the thermal dissipation requirements of portable personal computers (PCS) have increased from about 10 watts to 25 watts and even higher values. This increase in the thermal dissipation requirements is a result of ever increasing CPU performance and additional functionality; such as DVD, modem, audio and the like, which are provided by future PCS. As elucidated in an article by Albert Yu, “The Future of Microprocessors”, IEEE Micro, December 1996, pages 46 through 53, the trend of increasing power dissipation in the form of heat for portable personal computers will continue in the foreseeable future. Thus, at the widely employed A4 form factor for a portable personal computer; in essence, a 297 by 210 mm footprint, for instance, the cooling limit for a portable PC without an active cooling device, such as a cooling fan or providing additional passive cooling capacity is currently approximately 15 to 20 watts.
Although cooling capacity can be added through the installation of an active cooling device, such as a fan, this is normally not desirable inasmuch as these devices take up space, consume power and generate noise. Particularly in a portable personal computer, space and battery consumption and service life are at a premium, and the generating of noise is deemed to be highly undesirable. As a result, active cooling devices have been employed as a last resort in attempts to obtain additional cooling capacity. In contrast therewith, passive cooling methods and arrangements are considered to be most desirable and efficient since they do not consume any power, generate no noise and quite often take up no additional space. Thus, providing a greater cooling capacity than the current limits in order to meet the anticipated thermal dissipation requirements of future portable personal computers, represents not only a potential competitive advantage in industry, but also provides a significant product differentiation from currently available and commercially sold portable personal computers.
In particular with regard to the power consumption of laptop computers, there has been recently a continued increase in the power of the CPU. For example, the total of power of a laptop computer is normally about 10 watts, and has now increased to a range of about 30 to 40 watts or higher, whereas the CPU power has been increased from about 2 to 6 watts and, conceivably, can be as high as in the 10 watt range. Most of this power will eventually be dissipated in the form of heat to the surroundings. Consequently, being able to remove increased amounts of heat from the laptop computer becomes a critical factor in the construction and operation of such laptop computers.
One approach to solving the heat load problem is to run the processor chip, which is usually the greatest heat generator, at two different clock speeds, a slow speed which generates less heat, when the portable personal computer is used in a mobile environment, and a faster, hotter state when used in an immobile environment, such as when used in a docking station, where power and space is abundantly available. This allows the user to use the full speed of the processor while at a docking station where the full power of the computer is most often needed and at the same time the user can use the computer in a mobile state, i.e. powered by battery only and without a docking station, with the processor running at a reduced rate to minimize heat generation. In order for this approach to work, means for dissipating additional heat is needed when the computer is installed in a docking station.
DISCUSSION OF THE PRIOR ART
various arrangements and devices for increasing the cooling capacities of laptop computers are currently known in the technology.
Erler, et al., U.S. Pat. No. 5,704,212 discloses a heat sink in a docking station which comes into contact with the bottom of a computer when the latter is docked. A fan in the docking station then dissipates the heat from the heat sink into the ambient air. One problem with this approach is that the heat generated by the heat producing elements in the computer must be transmitted to the bottom contact area, either by restricting the placement of these heat producing elements to a bottom contact area or by transferring the heat by means of a conductive element or a heat pipe. Another problem with this approach resides in that the amount of heat removed through the bottom contact area is highly dependent upon the material which is used for the contact area. In most instances, material employed in presently produced portable personal computers is ABS plastic, which is a relatively poor choice of material for transmitting heat. When using a better conductor, such as aluminum, the amount of heat to which this area is subjected, even when the computer is operated at a lower power in a mobile mode, is enough to produce a hot spot which is uncomfortable for the user to touch when the computer is operated while resting on the lap of the user.
Paulsel, et al., U.S. Pat. No. 5,694,292 discloses a similar approach where a computer rests on spacers while docked in the docking station. This arrangement forms an air channel between a support shelf and the bottom of the computer. Air is then drawn through the air channel by means of a fan in the docking station thus cooling the bottom surface of the computer. However, this concept is subject to precisely the same disadvantages as the approach employed in Erler, et al.
Rahamim, et al., U.S. Pat. No. 5,550,710 discloses a device similar to a portable personal computer, called a personal processor module. In this publication, liquid heat sinks convey heat to an outer case of aluminum where either a fan or a heat pipe carries heat away from the surface of the case. While this represents an appropriate method of dissipating heat for a personal processor module since the latter does not come into contact with the user while in use, it would not be satisfactory for a portable personal computer since the user would be subject to touching an uncomfortably hot surface.
SUMMARY OF THE INVENTION
Accordingly, in order to clearly and unambiguously provide advantages over the current state-of-the-technology, the present invention discloses an automatic coupling arrangement or device between a heat pipe which is located within the portable personal computer and a heat dissipating arrangement located within a docking station. The heat pipe connection extending between the heat generating device in the computer, such as the electronics or a processor chip, and a coupling element representing one-half of a coupling device which resides between the computer is attachable to a second half of the coupling device which is a coupling element of the docking station, and wherein a heat dissipating arrangement communicating with the coupling device, such as a heat sink and a fan, is located within the docking station for transfer ring heat thereto from the computer.
Accordingly, it is an object of the present invention to provide an arrangement for effectuating the automatic coupling between a heat pipe of a portable personal computer and a heat dissipating arrangement including a heat sink located in a docking station in which the computer is adapted to be docked, and which facilitates the transfer of heat from the computer to the heat sink located in the docking station.
Another object of the present invention is to provide a method of coupling a heat pipe in a portable personal computer and which leads from a source of heat generation in the computer to a first coupling element, and wherein a second coupling element which is a component of a docking station, upon being coupled with the first coupling element when the computer is docked in the docking station, is adapted to have heat transferred thereto from the heat pipe and transferred to a heat sink in the docking station so as to dissipate the heat received from the computer.
BRIEF DESCRIPTION OF THE DRAWINGS
Reference may now be had to the following detailed description of preferred embodiments of the invention, taken in conjunction with the accompanying drawings; in which:
FIG. 1 illustrates, generally diagrammatically, a perspective rear and side view of a portable personal computer which is in the process of being docked in a docking station;
FIG. 2 illustrates, on an enlarged scale, a portion of the personal computer and docking station of FIG. 1, showing the coupling arrangement for the transfer of heat from the computer to the docking station in an uncoupled position;
FIG. 3 illustrates, in a manner similar to FIG. 1, the portable personal computer in a docked position on a docking station, with portions being broken away to show the interconnected coupling arrangement for the transfer of heat from the computer to the docking station;
FIG. 4 illustrates an enlarged axial cross-sectional view of the coupling arrangement as utilized in FIG. 3;
FIG. 5 illustrates, generally diagrammatically, an exploded perspective view of a second embodiment of a coupling arrangement for the thermal interconnection between a portable personal computer and a docking station;
FIG. 6 illustrates, generally diagrammatically, an internal perspective representation of the portable personal computer of FIG. 5, with portions of the internal components having been removed for purposes of clarity;
FIG. 7 illustrates, on an enlarged scale, a perspective detail view of one-half of the thermal coupling arrangement which is thermally attached through the intermediary of a heat pipe to a heat dissipating device, as employed in the embodiment of FIG. 5; and
FIG. 8 illustrates, on an enlarged scale, an elevational cross-sectional view of a modified thermal coupling device with one element of the coupling device being thermally attached through the intermediary of a heat pipe to a heat dissipating device in a docking station, and being illustrative of the mounting aspect thereof.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
Basically, heat pipes operate on the principle that a liquid will boil when heated in a sealed container having a volume of the liquid contained therein, where the gaseous or vaporized liquid flows to the colder end of the sealed container and condenses, thus transporting heat energy from the hot end to the cold end of the container. The condensate then returns to the hot end of the container either by gravity or by gravity assisted by a wick contained in the volume. These devices are well known in the art and can be obtained by purchasing them from; for example, Thermacore Corporation, Lancaster, Pa., or Fujikura, Ltd., Tokyo, Japan. These devices are capable of transferring heat at a rate that is equivalent to 100 to 200 times that of the conductivity of copper.
Referring to FIG. 1, which represents a perspective, partly broken away view of a portable personal computer 10 resting on but not yet docked a docking station shelf 12 of a docking station 14 , the computer contains a heat generating device 16 such as a processor chip mounted on a printed circuit board 18 . Attached on top of the heat generating device 16 is a heat spreader 20 , this attachment being made such that heat generated by the heat generating device 16 will readily conduct heat to heat spreader 20 . This is a process which is well known in the technology. In a similar manner, heat pipe 22 is thermally attached to the heat spreader 20 .
The cold end of the heat pipe 22 is thermally attached to a receiving socket 24 of a coupling device. Socket 24 is made of a material possessing a good thermal conductivity, such as copper or aluminum.
When portable personal computer 10 is pushed forwardly in the direction of arrow A so as to be docked in the docking station 14 , plug 30 is automatically inserted into the socket 24 . The plug 30 has one end of a second heat pipe 36 thermally attached thereto, whereas the opposite end of heat pipe 36 is thermally attached to a heat sink 44 in the docking station 14 . Heat from heat sink 44 is then dissipated into the ambient air by natural convection or by means of a fan 46 .
Referring to FIG. 2, at the end of the motion causing the docking of the computer 10 , after the plug 30 has been inserted into socket 24 , a spring 38 is compressed so as to exert an axial force against the plug 30 . A reaction force from the spring 38 is taken up by a stationary bracket 40 . The motion of compressing of the spring 38 is taken up by permitting platform 42 carrying the heat sink 44 to slide along rods 48 and 50 which are attached to the stationary bracket 40 . However, numerous other ways are possible to take up the motion of the heat sink 44 ; for example, if the heat sink 44 is sufficiently small, which would be likely if the amount of heat which is to be removed is small, then the heat sink 44 can simply cantilever off the heat pipe 36 , thereby eliminating the need for rods 48 and 50 .
An important consideration in transferring heat from heat pipe 22 to socket 24 is to provide for a large area of contact with a good thermal connection therebetween. For example, a 3 mm diameter copper heat pipe inserted into a hole in a copper block which is 25 mm deep, has a clearance of 25 to 50 micrometers, and when the two pieces are soldered together, this provides enough thermal conductivity at the interface such that approximately eight watts of power can be transferred to the block for a temperature difference of six degrees C. If a greater power dissipation is necessary, larger diameter heat pipes and proportionally greater areas of contact can be employed.
The heat pipe 22 is inserted into a hole 26 in socket 24 and soldered in place. Another hole 28 in the socket 24 has a conical shape to accept a similarly shaped plug 30 when the portable personal computer 10 is pushed forwardly to dock it in the docking station 14 . In this position, as shown in FIG. 3, heat is transferred from the socket 24 to the plug 30 across the interface of surface 32 , as shown in FIG. 2, on socket 24 and surface 34 on the plug 30 . Plug 30 has a central hole 30 a through which a second heat pipe 36 is inserted and then soldered thereto, whereas the opposite end of heat pipe 36 is thermally attached to the heat sink 40 .
The axial force acting on the plug 30 causes a normal force to be exerted against socket surface 32 the by plug surface 34 which is equal to the axial force divided by the sine of the cone angle (axis to surface) of plug 30 . A small or acute cone angle (with the sine of the angle approaching zero) will cause the formation of an extremely large normal force. However, it is well known that friction and the elasticity of the material causes small or acutely angled conical plugs to lock into mating conical holes. A standard “self-releasing” taper, in effect, one that does not lock, is one which subtends an angle of 3.5 inches per linear foot, or about sixteen degrees. This is close to an optimum angle for generating a large surfaced normal force but which still does not lock the socket and plug together. The angle could be made smaller or narrower by the application of friction-reducing coatings.
In order to provide for a good contact between the surfaces 32 and 34 , there must be some angular compliance between the plug 30 and socket 24 . One method of achieving this is if heat pipe 36 is of a smaller diameter (3 or 4 mm), it will flex enough to allow the plug 30 to seat into socket 24 . Alternatively, if heat pipe 36 does not allow for an adequate compliance, soft compliant bushings 52 may be used between hard bushings 54 and the platform 42 . Another means of accommodating compliance which is shown in a further embodiment hereinbelow, is to insert a compliant member, such as a sponge rubber element between the heat sink 44 and the platform 42 . Additionally, as stated above, if heat sink 44 can be cantilevered off heat pipe 36 , then the heat sink 44 would be free to move so as to be able to accommodate small angular errors.
In order to attain an almost negligible thermal resistance between the surfaces 32 and 34 when these are engaged, the area of contact is needed to be about twice that of the soldered joint between the heat pipe 22 and the socket 24 . For example, a 3 mm diameter heat pipe soldered into a hole which is 20 mm deep has a contact area of 251 mm 2 . A conical frustum which has a minor diameter of 4 mm, a cone angle of 16 degrees and a height of 17 mm has a lateral area of 498 mm 2 .
Inasmuch as an important consideration in designing a portable personal computer is to make the construction thereof as light as possible, the socket 24 is produced from as little material as possible. The socket consists of a conical cavity 28 , with the hole 26 arranged optimally with its axis extending parallel to the lateral face of conical cavity 28 , and with approximately one-millimeter thick material surrounding these two cavities, a detail of the socket 24 and plug 30 being shown in FIG. 4, the latter being a sectional view taken along a plane extending through the respective centerlines of cavities 26 and 28 .
Another embodiment of the present invention is shown in FIG. 5 . In this embodiment, there is employed a docking station 124 without a sliding shelf 12 . Instead, a computer 110 is equipped with an electrical plug 112 , a thermal plug 114 and a thermal socket 116 on the bottom thereof adapted to mate with, respectively, an electrical socket 118 , a thermal plug 120 and a thermal socket 122 located on docking station 124 . Since there is no sliding shelf provided adapted to accurately guide computer 110 such that electrical plug 112 aligns with electrical socket 118 , the thermal plugs 120 and 114 and sockets 120 and 122 may be used for this purpose. Plug 120 and socket 114 are conically shaped, as in the previous embodiment, whereas the 116 and socket 122 are wedge-shaped. This arrangement allows the conical plug 120 and socket 114 to locate computer 110 in a plane parallel to its bottom surface, and wedge plug 116 and socket 122 to rotationally locate computer 110 with the same plane. A resting pad 126 is located on the docking station 124 , which supports computer 110 at one point while engaged with docking station 124 . The thermal plug 120 and thermal socket 122 serve as two other resting points. By means of this three-point resting arrangement, the socket 114 and plug 116 are ensured as to their proper seating in, respectively, plug 120 and socket 122 .
Referring to FIG. 6, socket 114 and plug 116 are thermally attached to heat pipes 128 and 130 in the computer, which in turn are connected to heat generating devices, as in the previous embodiment. Socket 122 is thermally connected to heat pipe 132 which is, in turn, thermally connected to heat sink 134 , as shown in FIG. 7 . Similarly, plug 120 is connected to heat pipe 138 and heat sink 140 , as shown in FIG. 8 . It is to be understood that heat pipes 132 and 138 may not be necessary in all applications, and that conductive means for transferring heat may be used instead of heat pipes 132 and 138 .
Structure may be required in order to take up small angular misalignments of the plug 120 and socket 122 when these are engaged in, respectively, socket 114 and with plug 116 . Referring to FIG. 8, plug 120 is provided with a shoulder 142 and a tapered guide shaft 144 . The shaft 144 is inserted into a hole 146 through a stationary bracket 148 , and plug 120 rests on shoulder 142 . Plug 120 is loosely secured by means of washer 150 and screw 152 . When socket 114 engages the plug 120 , the plug 120 is then allowed to tilt through a small angle, since the tapered shaft 144 is also permitted to tilt through a small angle within the hole 146 . Socket 122 is provided with has a similar mounting arrangement. When small angles are accommodated in this manner, the motion of plug 120 and socket 122 must be taken up in some way, consequently, as stated above, small diameter heat pipes made of flexible material may flex to take up this motion. Another method would be to mount heat sinks 134 and 140 on a flexible resilient pad 154 , such as made of sponge rubber, as shown in FIGS. 7 and 8.
While there has been shown and described what are considered to be preferred embodiments of the invention, it will, of course, be understood that various modifications and changes in form or detail could readily be made without departing from the spirit of the invention. It is, therefore, intended that the invention be not limited to the exact form and detail herein shown and described, nor to anything less than the whole of the invention herein disclosed as hereinafter claimed.
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An arrangement and method for enhancing the cooling capacity of portable personal computers. More particularly, there is provided to the provision of an arrangement for increasing the cooling capacity of portable personal computers, particularly such as laptop or notebook computers. The computer possesses a keyboard having the rear edge thereof hingedly connected with the bottom of an openable display unit or panel, and containing heat-generating computer electronics, from which heat is removed through a heat pipe terminating in a coupling arrangement possessing elements which connect to and disconnect from each other when, respectively, docking and undocking the portable personal computer in a docking station so as to facilitate the transference of heat from the portable personal computer through the coupling arrangement into the docking station from whence the heat is dissipated to the surroundings through the intermediary of a heat sink.
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This application claims the benefit of U.S. Provisional Application No. 60/096,888 filed Aug. 17, 1998.
BACKGROUND OF THE INVENTION
This invention relates, in general, to scoring tools, and, in particular, to scoring tools for wallpaper removal.
DESCRIPTION OF THE PRIOR ART
In the prior art various types of scoring tools have been proposed. For example, U.S. Pat. No. 2,295,317 to Young discloses a roughing tool with a plurality of cutting wheels each of which has a plurality of teeth thereon.
U.S. Pat. No. 2,677,180 to Schierghofer discloses a cutter for wall coverings which has a single wheel with cutting teeth.
U.S. Pat. No. 2,684,533 to Kern discloses a cutter having two cutting wheels.
U.S. Pat. No. 3,514,854 to Norfleet discloses a scarifier which has a plurality of teeth, each of which has a plurality of teeth thereon.
SUMMARY OF THE INVENTION
The present invention is directed to a scoring tool which can be used to aid in removing wallpaper. The tool has a hand grip to which is connected a pair of cutting wheels. The wheels are mounted in the lower portion of the hand grip so the wheels diverge away from each other.
It is an object of the present invention to provide a new and improved scoring tool for aiding in the removal of wallpaper.
It is an object of the present invention to provide a new and improved scoring tool which is easy to use.
It is an object of the present invention to provide a new and improved scoring tool which will move easily in a pivoting motion.
These and other objects and advantages of the present invention will be fully apparent from the following description, when taken in connection with the annexed drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a side view of the present invention.
FIG. 2 is an end view of the present invention.
FIG. 3 is a view of the present invention showing the internal shape of the tool.
FIG. 4 is a partial view of the scoring wheels of the present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring now to the drawings in greater detail, FIG. 1 shows the scoring tool 1 of the present invention. The tool is designed to puncture wallpaper that is to be removed from a wall. The punctures in the wallpaper allow a solution, that will loosen the glue that holds the wallpaper, to penetrate through the wallpaper and reach the underlying glue. This tool will also be useful if there are more than one layer of wallpaper or if the wallpaper has been painted over, since in these instances it will be harder for the removal solution to reach the underlying glue.
The tool 1 is made in two identical housing halves 2, as shown in FIG. 2, which will be held together by screws or bolts (not shown) passing through apertures 4. Each of the housing halves 2 have a groove 3 which provides a place for the user to position their fingers as they are using the tool. The groove will position the user's fingers away from the cutting blades 5. In addition, projection 13 also serves to protect the user's fingers from the cutting blades.
At the bottom of the housing halves 2 are positioned two cutting or scoring wheels 5. Each of the wheels 5 are fashioned as saw blades with a plurality of teeth 12 positioned around the periphery, as shown in FIGS. 2 and 4. As can be clearly seen in FIG. 4, the teeth 12 are alternatingly set to the right and left of an imaginary center line passing through the plane of the circular blade. This alternating set of the teeth will allow clearance when cutting, and, in addition, they will provide a wider array of holes in the paper than if the blades were positioned inline. That is, since the teeth are offset each tooth will make a hole to one side of the center line of the blade and the next tooth will make a hole to the opposite side of the center line of the blade. If all the teeth were aligned, the holes would be inline or even overlap.
In addition, as seen in FIG. 3, the blades 5 are inclined with respect to the longitudinal center line of the housing halves 2. The preferred inclination A is 20° from the center line 13 of the housing half 2. The angle that each blade makes to the perpendicular is reversed so that the blades 5 diverge away from each other as they exit the bottom of the housing halves 2. This design allows the blades to rotate freely without interference which would occur if the blades 5 were parallel. Also, the geometry of the blades allow the tool 1 a pivoting rotation as the user moves the tool over the wall.
As shown in FIG. 4, each blade 5 is mounted on an axle 10 and held on the axle by flanges 11. It should be noted that the blades could be permanently mounted on the axle by making the flanges fixed to the axle, or the blades 5 could be made removable by making at least one of the flanges 11 removable.
As shown in FIG. 3, each blade is mounted in a lower portion of the housing halves 2 so the blades project approximately 1/8 inch from the bottom of the housing. Each of the housing halves 2 have a recess 6 to receive the blade and allow it to rotate. In addition, the housing halves each have recesses 7 to receive the flanges 11, and supports 9, 9' to support the axle 10.
Although the Scoring Tool and the method of using the same according to the present invention has been described in the foregoing specification with considerable details, it is to be understood that modifications may be made to the invention which do not exceed the scope of the appended claims and modified forms of the present invention done by others skilled in the art to which the invention pertains will be considered infringements of this invention when those modified forms fall within the claimed scope of this invention.
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A a scoring tool which can be used to aid in removing wallpaper. The tool has a hand grip to which is connected a pair of cutting wheels. The wheels are mounted in the lower portion of the hand grip so the wheels diverge away from each other.
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This application is a division of Ser. No. 239,569, filed Sept. 1, 1988, now Pat. No. 4,918,033.
FIELD OF THE INVENTION
The present invention relates generally to the deposition of conductive layers on a substrate. More particularly, it relates to a plasma enhanced CVD process for the deposition of tungsten or layers containing tungsten on a semiconductor surface by in situ formation of tungsten fluorides in the reaction chamber.
BACKGROUND OF THE INVENTION
In the development of VLSI technology, there is a strong demand for improved microfabrication techniques and materials, e.g., refractory metals, which are used for self-aligned gate processes. Conventionally used polysilicon, although having many desirable properties, such as good etchability, good oxidation characteristics, mechanical stability at high temperatures, excellent step coverage and adhesion, has the major disadvantage of a relatively high resistance. A heavily doped 0.5 micron thick polysilicon film, for example, has a sheet resistance of about 20 to 50 ohms per square, which is a major constraint in VLSI circuit design. Therefore, as line widths in VLSI circuits shrink, the major speed limitations arise from the RC time constant associated with silicon gates and polysilicon interconnect lines, thereby limiting high speed performance at very reduced geometries. To reduce interconnect resistivity, it is desirable to deposit refractory metals or metal silicides instead of polysilicon lines.
Refractory metals for VLSI applications are customarily deposited by three different methods: sputtering, evaporation, and chemical vapor deposition. The main advantage of the sputtering process is that both pure refractory metals and refractory metal silicides can be sputtered. The disadvantage of sputtering is poor step coverage.
Evaporation of refractory metals has been investigated as a means for forming VLSI. However, evaporation has many of the deficiencies associated with sputtering. For example, step coverage is poor, and the deposition process is complex using evaporation techniques.
Chemical vapor deposition (CVD) and low-pressure chemical vapor deposition (LPCVD) of refractory metals offer several advantages over sputtering and evaporation techniques. CVD of refractory metals can provide good coverage, reduced system complexity, and higher purity deposits. Also, in some applications, selective CVD does not require an additional photolithography step when the refractory metal is deposited only on areas with certain chemical reactivities. For example, tungsten hexafluoride will react with silicon or polysilicon gates, but not with the surrounding silicon dioxide isolation areas.
However, tungsten films formed in the past by CVD methods have suffered from a number of limitations. Tungsten films formed by the hydrogen reduction of tungsten hexafluoride, according to the equation,
WF.sub.6 +3H.sub.2 →W+6HF (1)
produce hydrofluoric acid as a by-product. This is undesirable since the HF tends to etch away the silicon dioxide area surrounding the polysilicon gate, potentially destroying the device. Also, the thickness of films formed by the hydrogen reduction method is difficult to reproduce, and the films formed by this method are highly stressed which can cause delamination of the films from the substrate.
Tunsten films also have been formed by the silicon reduction of tungsten hexafluoride according to the equation:
2WF.sub.6 +3Si+2W+3SiF.sub.4 ( 2)
This reaction has two major disadvantages. Like the hydrogen method, the films produced by this method are highly stressed. Furthermore, the silicon reduction method requires that silicon be available in order for the reaction to take place. As the tungsten is deposited, less and less silicon is available from the underlying area, which causes the reaction to be self-limiting. Typically, only films of about 30 to 40 nm thickness can be deposited. Beyond this thickness, other methods of depositing tungsten are required.
A refinement of the CVD method consists in decomposing tungsten hexafluoride by igniting a discharge plasma, which permits a drastic reduction in the reaction temperature. This most up-to-date method is known as Plasma Enhanced Chemical Vapor Deposition (PECVD).
However, the reaction gas tungsten hexafluoride used in CVD and PECVD methods poses several severe problems. Tungsten hexafluoride is highly toxic. Due to its boiling point of 17.06° C. and vapor pressure of 1.6 bar at 30° C., longer lines have to be avoided and/or the temperature of the entire supply means has to be stabilized. Further, tungsten hexafluoride has been found to be difficult to control, and it decomposes valves and flow controllers. And, it is difficult to obtain in a highly pure form, and, in addition, when available in that form, it is very expensive.
SUMMARY OF THE INVENTION
Accordingly, it is an object of the present invention to provide a method for depositing tungsten which eliminates the above-mentioned difficulties.
The advantages offered by the invention are mainly that the gas, WF x , which is normally used to deposit tungsten layers or layers containing tungsten, is formed in the plasma deposition chamber by the action of a suitable etch gas on a suitable cathode material, e.g., tungsten.
In accordance with the invention, there is provided a PECVD method for depositing a refractory metal layer on a semiconductor substrate in a plasma deposition chamber, which comprises a refractory metal cathode and an anode. In the method of the invention, a fluoro compound etch gas is reacted with the refractory metal cathode in the deposition chamber to convert the metal to gaseous refractory metal fluorides, and a layer of the refractory metal is deposited on a semiconductor substrate positioned on the anode of the chamber by exposing the substrate to the gaseous refractory metal fluorides.
The invention also provides an apparatus for the deposition of refractory metal layers or layers containing refractory metal on a semiconductor substrate. In accordance with this aspect of the invention, the apparatus comprises a plasma deposition chamber having a port through which a fluoro compound etch gas is introduced into the chamber and a port through which the chamber is evacuated, a refractory metal cathode configuration within the chamber, an anode within the chamber, and energy impression means for ionizing the etch gas in the chamber, whereby the etch gas reacts with the refractory metal cathode configuration to convert the metal to gaseous refractory metal fluorides which decompose to form a deposited layer on a semiconductor substrate positioned on the anode.
The foregoing and other objects, features and advantages of the invention will be apparent from the following more particular description of the preferred embodiments of the invention, as illustrated in the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is an illustration of a plasma deposition system with in situ formation of WF x .
FIG. 2A is a mass spectrum graph of the gas emerging from the deposition system after the introduction of CF 4 into the chamber.
FIG. 2B is a mass spectrum graph of the gas emerging from the deposition system after the introduction of CF 4 into the chamber and plasma ignition.
FIG. 2C is a mass spectrum graph of the gas emerging from the deposition system after the introduction of WF 6 into the chamber.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
The present invention provides for the reaction gas necessary for the PECVD method to be generated in the plasma deposition chamber by plasma etching a suitable cathode material. For this purpose, the different reaction characteristics at the cathode (etching) and at the anode (deposition) of the plasma deposition chamber are utilized.
The system for carrying out the method of the invention is shown in the schematic of FIG. 1. The apparatus is a modified Plasma Therm PK 14 deposition system operating at 13.56 MHz. The chamber 10 contains a cathode and an anode 26. The cathode configuration consists of an electrode 18 and a tungsten sheet 24 of the same size which is spaced about 1 cm from the electrode 18. The electrode 18 and the tungsten sheet 24 are electrically connected to form a `hollow cathode`. Silicon wafers 28 are placed on the anode 26 which is spaced about 8 cm from the tungsten sheet 24. The etch gas (e.g., CF 4 , NF 3 , SF 6 , etc.), which acts on the tungsten sheet 24, is introduced into the chamber 10 through a port 12 and enters the hollow cathode region 20 via a gas shower 22. The etch gas is excited by an h.f. generator 16. A vacuum pump (not shown) is provided to evacuate the chamber 10 through the port 14. The operation of the hollow cathode system results in an increased yield of electrons and free radicals in the hollow cathode region 20 between the cathode 18 and the tungsten sheet 24 owing to a higher ionization level of the discharge in this region. As a result, a higher number of WF x ions will diffuse towards the targets 26 with silicon wafers 28. Details of a hollow cathode system are described, for example, by Ch. M. Horwitz, in "Hollow cathode reactive sputter etching--A new high-rate process", Appl. Phys. Lett. 43(10), 15 Nov. 1983, pp. 977-979, which is incorporated herein by reference.
In accordance with the invention, the action of an etch gas, such as CF 4 , SF 6 , NF 3 , etc., on the tungsten sheet 24 provides active species WF x which are caused to decompose in the vicinity of the substrates 28, forming a deposited tungsten layer or a layer containing tungsten thereon.
In a practical example, CF 4 is bled into the system and a plasma is ignited in the reaction chamber 10. As mentioned above, a spacing of about 1 cm between the cathode 18 and the tungsten sheet 24 is employed. The cathode/anode spacing is not critical; a spacing of about 8 cm is employed. The flow rate of CF 4 is about 50 sccm/min. The deposition system operates with the h.f. power of 13.56 MHz. The pressure, monitored by a baratron gauge (not shown), is maintained at a value of 9.0 Pa by a throttle valve (also not shown). The deposition chamber 10 is kept slightly above room temperature at about 50° C. The anode 26 which carries wafers 28 is not heated. The gas which is produced after the introduction of 50 sccm/min. of CF 4 and which emerges from the exhaust side of the chamber 10 is analyzed, using a differentially pumped quadrupole mass spectrometer. The method used for this purpose is described by J. Bartha et al. in "IN SITU DETERMINATION OF GROWTH RATE AND STOCHIOMETRY IN A HETEROGENEOUS CVD REACTOR", IBM Technical Disclosure Bulletin, Vol. 29, No. 11, Apr. 1987, p. 4851, which is incorporated herein by reference.
FIGS. 2A-C show mass spectra of the gas emerging from the system under different conditions as measured with identical sensitivity. After the introduction of CF 4 , no significant masses could be observed in the mass range 150-300 (FIG. 2A). The conditions of FIG. 2B are obtained by plasma ignition.
Particularly evident, are six new groups of mass peaks, each containing four single peaks corresponding to the natural tungsten isotopes 182 (26.5%), 183 (14.5%), 184 (30.5%) and 186 (28.5%). The six groups correspond to W and the fluoro compounds WF, WF 2 , WF 3 , WF 4 , and WF 5 , respectively. The conclusion to be drawn from this is that WF x compounds are formed by CF 4 etching the tungsten sheet 24 connected to the cathode 18. A gas containing WF x compounds, i.e. WF 6 , is normally used to deposit tungsten layers or layers containing tungsten. Systematic tests have shown that the concentration of the WF x compounds is less dependent on the CF 4 flow than on the HF power, which clearly points to a plasma-induced chemical reaction.
However, a guantitative evaluation of the mass spectrum of FIG. 2B is difficult, as the formation of tungsten and/or WF x constitutes an absolute change. To be able to determine to what inlet flow of WF 6 the intensity of tungsten and/or WF x (FIG. 2B) corresponds, a mixture of nitrogen and WF 6 was introduced into the chamber 10. For this purpose, the basic pressure of the chamber was adjusted by a nitrogen flow, then WF 6 was added from the outside according to the state of the art, and the tungsten and/or WF x intensities were determined without maintaining the plasma. FIG. 2C shows the mass spectrum in this case. For a qualitative evaluation, WF 6 flows of 0, 10, 20 and 30 sccm/min. were used. It is remarkable that the quality of the cracking pattern of WF 6 , i.e., the groups to be associated with the tungsten isotopes W, and/or their fluoro compounds WF, WF 2 , WF 3 , WF 4 , and WF 5 (FIG. 2C) substantially match those of FIG. 2B. This means that the gas composition of WFx ions formed in situ by the etch reaction according to the invention corresponds to that of the gas formed by the introduction of WF 6 .
A comparison of the intensities of WF x , formed in situ by the etch reaction, with the intensities formed by the introduction of WF 6 , indicates that the parameters of the former yield a WF x concentration in the deposition chamber which corresponds to a WF 6 flow of about 7.5 sccm/min. According to the state of the art (D. L. Brors et al., SEMICONDUCTOR INTERNATIONAL, May 1984, pp. 82-85; and K. Akitmoto et al., Appl. Phys. Lett. 39(5), September 1981, pp. 445-446), WF6 flows of about 5 to 50 sccm/min. are generally used to produce tungsten layers or layers containing tungsten.
In the above example, a layer which clearly contained tungsten was deposited on silicon dioxide wafers 28. The test method used was EDAX (energy dispersive analysis of X-rays). This method is unfortunately insensitive to light elements, such as C or F. Therefore, ESCA (electron spectroscopy for chemical analysis) was used as a further test method. A tungsten layer contaminated with polymerized CF 4 was detected. The drawback of polymerized CF 4 may be remedied by the use of another etch gas.
The present invention shows that a gas may be chemically produced in a plasma reaction chamber by the reaction of a selected gas with the cathode material. The gas thus produced is suitable for depositing the cathode material on semiconductor substrates arranged on the anode. This deposition method corresponds to the previously mentioned PECVD method with its known advantages, in particular, uniform step coverage of structured substrates. Trends that seem to be emerging in semiconductor technology are to use pure tungsten as a gate material for future chip generations with still lower sheet resistances. Such chip generations also require low process temperatures. These requirements are met by the process according to the invention.
While the invention has been particularly shown and described with reference to preferred embodiments thereof, it will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention. For example, it should be understood that modifications with respect to the etch gas and the cathode material may be made; specifically, molybdenum or layers containing molybdenum can be deposited in the manner described in conjunction with tungsten.
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The apparatus comprises a plasma deposition chamber having a port through which a fluoro compound etch gas is introduced into the chamber and a port through which the chamber is evacuated, refractory metal cathode configuration within the chamber, an anode within the chamber, and energy impression means for ionizing the etch gas in the chamber, whereby the etch gas reacts with the refractory metal cathode configuration to convert the metal to gaseous refractory metal fluorides which decompose to form a deposited layer on a semiconductor substrate positioned on the anode.
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RELATED APPLICATIONS
[0001] This application claims the benefit of priority to U.S. Provisional Patent Application Ser. No. 60/914,475, filed Apr. 27, 2007.
FIELD OF THE INVENTION
[0002] The invention relates to the field of coupling gels used to aid in the transmission of ultrasound waves, and to the use of ultrasound probe position fixation devices.
BACKGROUND OF THE INVENTION
Ultrasonography
[0003] Ultrasonography, also known as sonography, is a technique used in medical imaging in which high-frequency sound waves (typically between 1 and 20 MHz) are reflected off internal organs and the echo pattern is converted into a picture of the structures beneath the transducer. Because ultrasound images are captured in real-time, they can show the structure and movement of the body's internal organs, as well as blood flowing through blood vessels.
[0004] Ultrasound examinations can help to diagnose a variety of conditions and to assess organ damage following illness. Ultrasound is used to help physicians diagnose symptoms such as pain, swelling and infection. Ultrasound is a useful way of examining many of the body's internal organs and conditions, including but not limited to the: heart and blood vessels, including the abdominal aorta and its major branches (for example, for abdominal aortic aneurism); liver; gallbladder; spleen; pancreas; kidneys; bladder; uterus, ovaries, and unborn child (fetus) in pregnant patients; ectopic pregnancy; eyes; thyroid and parathyroid glands; scrotum (testicles); and breast. Ultrasound is also used to diagnose a variety of heart conditions and to assess damage after a heart attack or other illness.
[0005] In addition, ultrasound is increasingly used to guide medical procedures such as those involving needle puncture. Examples include, but are not limited to; needle delivery of anesthesia; placement of central venous catheters; placement of pulmonary artery catheters; needle biopsy and fine needle aspiration; amniocentesis; femoral catheter placement; and, egg harvesting. In these and other applications, a sterile coupling gel is often used. The ultrasound transducing surface is coated with a sterile or non-sterile gel, and then the transducer may be placed in a sterile fragile sheath. The outer surface of the sheath, or the surface of the patient's skin, is then coated with sterile ultrasound gel.
[0006] Conventional methods for targeted delivery of local anesthesia have been utilized with varying success for decades. A traditional method includes assessing needle location using the tactile feedback (clicks, pops) that the needle generates as it penetrates tissue adjacent to the desired nerve site. Another method attempts to correctly locate the anesthesia needle using paresthesia, the abnormal neurological sensations that results when the needle touches the intended nerve.
[0007] A slightly more advanced method to guide anesthesia delivery which has largely supplanted the older methods of clicks, pops or paresthesia is that of nerve stimulation. In this method, an insulated needle is attached to an electrically charged live wire. As the needle approaches the nerve, the patient will experience an involuntary movement caused by the electrically charged needle stimulating the desired nerve once it is sufficiently close to the nerve.
[0008] In addition to being unreliable in correctly identifying the nerve, these conventional procedures are fairly slow and can be unsafe to the patient due to the need for multiple and/or incorrectly placed injections. Ultrasound guided delivery of anesthesia provides a more effective, safer and faster alternative to these conventional approaches.
[0009] Central venous catheter line placement has also been traditionally executed using a ‘feel’ approach. Certain anatomical landmarks such as bones are used to identify the location of the jugular vein. However, obesity, vascular disease, hypotension, and many other factors can create a unique set of challenges in correctly identifying the location for even the most experienced healthcare provider. The American College of Emergency Physicians has recognized the importance of this skill by including it in the 2001 policy statement “Use of Ultrasound Imaging by Emergency Physicians” (Ann. Emerg. Med. 2001; 38:469-70), which calls ultrasound-guided central venous access one of the “primary applications for emergency ultrasound.”
[0010] In performing needle biopsy, such as breast biopsy, ultrasound guidance has proven quite valuable. After placing an ultrasound probe over the site of the breast lump and using local anesthesia, the radiologist guides a biopsy needle directly into the mass. Tissue specimens are then taken using either an automatic spring-loaded or vacuum-assisted device (VAD). Ultrasound is most often used to guide breast biopsy when a breast abnormality is visible on ultrasound. When it is necessary to do an open surgical biopsy, a guide wire first is passed directly into the mass. This procedure also may be guided by ultrasound.
[0011] Other broad applications of sonography include phonophoresis and wound healing. Phonophoresis (also known as sonophoresis or ultrasonophoresis) is the movement of a medication or other substance through the skin by the application of sonic radiation to the medicament placed upon the skin. In wound healing, ultrasound plays a role because it has been well established that ultrasound by itself can speed up the healing process in open wounds.
[0012] More recently, the use of high intensity focused ultrasound (HIFU) for therapeutic purposes, as opposed to imaging, has received significant attention in the medical community. HIFU therapy employs ultrasound transducers that are capable of delivering 1,000-10,000 W/cm 2 to a focal spot, in contrast to diagnostic imaging ultrasound, where intensity levels are usually below 0.1 W/cm 2 . A portion of the energy from these high intensity sound waves is transferred to the targeted location as thermal energy. The amount of thermal energy thus transferred can be sufficiently intense to cauterize undesired tissue, or to cause necrosis of undesired tissue (by inducing a temperature rise to beyond 70° C.) without actual physical charring of the tissue. Tissue necrosis can also be achieved by mechanical action alone (i.e., by cavitation that results in mechanical disruption of the tissue structure). Further, where the vascular system supplying blood to an internal structure is targeted, HIFU can be used to induce hemostasis. The focal region of this energy transfer can be tightly controlled so as to obtain necrosis of abnormal or undesired tissue in a small target area without damaging adjoining normal tissue. Thus, deep-seated tumors can be destroyed with HIFU without surgical exposure of the tumor site.
Ultrasound Coupling Gels
[0013] Sound waves are poorly transmitted by air and thus require a coupling mechanism for proper transmission. This coupling mechanism is commonly a viscous fluid or gel which, due to its physical and acoustic properties, acts to displace air, fill contours between the piezoelectric transducer and the body, and enable successful transfer of the acoustic energy. Many ultrasound coupling gels exist in the market place in both sterile and non-sterile forms. Sterile ultrasound gels include Sterile Aquasonic® 100 (Parker Labs, Inc., Orange, N.J., 07050), Ultra/Phonic™ (Pharmaceutical Innovations, Newark, N.J.), UltraBio Sterile (Sonotech, Bellingham, Wash., 98225) and Sonogel—Sterile (Sonogel Vertriebs GmbH, D-65520 Bad Camberg). Sterile ultrasound gels are typically provided in single-use individually wrapped sterile foil pouches of 20 g each. The UltraBio product (U.S. Pat. No. 6,866,630 to Larson et al.) describes an in vivo biocompatible, bioeliminating sterile diagnostic ultrasound imaging couplant and lubricant.
[0014] Some ultrasound applications, for example fetal ultrasound, desire the ability to continuously move and reposition the ultrasound probe in order to gain multiple images at multiple angles of multiple sites. Other ultrasound applications, such as but not limited to the ultrasound guided procedures described above, desire the ability to move the ultrasound transducer until an optimal position is located, and then desire the probe to remain stable in this position until the user intentionally adjusts the position of the probe. In these applications, the ultrasound probe is commonly held in one hand of the caregiver while the procedure requiring guidance is performed with the other hand. Current ultrasound coupling gels generally exhibit a slippery or low friction state and thus leave the probe susceptible to unwanted movement, potentially leading to loss of visualization of the target site, the need to relocate the site, misguided or repeat punctures and an overall decrease in safety, effectiveness and procedure efficiency.
[0015] Efforts to utilize adhesive or bioadhesive coupling agents have been disclosed. U.S. Pat. No. 5,522,878 to Montecalvo et al. describes a solid, multipurpose, flexible, ultrasonic, biomedical couplant hydrogel in sheet form to facilitate transfer of ultrasound energy to and from a patient. Also described is a method of attaching the sheet to skin to hold the couplant gel in place during an exam, which constitutes a band of pressure sensitive adhesive bonded to plastic foam, such as foamed rubber, that is located along the outer perimeter of the sheet. The hydrogel sheet described is not adhesive in and of itself, but depends on sufficient perspiration to make the gel somewhat tacky. The adhesive border, so described, is not acoustic self-coupling, therefore restricting ultrasound scanning to areas exclusive of those covered with adhesive covered foam. The level of adhesion of the hydrogel sheet is fixed and the tacky surface is only between the skin and the sheet. It is meant to cling to the skin while the transducer moves freely on top of it. It is not intended to aid in the maintenance of the probe's final position, but rather to improve ease of handling by being easily applied to and removed from the body.
[0016] U.S. Pat. No. 6,719,699 to Smith describes adhesive hydrogel films or sheets as acoustic coupling media attachable to the active face (transducer) of ultrasound instruments (such as probes or scanheads) and to the inner face of latex, polyurethane or other polymeric probe covers; thereby, enabling the transfer of acoustic energy between an ultrasound probe and an object of interest when used in conjunction with a gel or liquid ultrasound couplant on the skin surface. The adhesive hydrogel comprises acoustic transmission media and is adhesive on both sides of the film. Such adhesive hydrogels films are so comprised as to render desirable levels of acoustic transmission with acceptable low levels of acoustic artifacts, distortion and attenuation. The invention of U.S. Pat. No. 6,719,699 allows for an adhesion between the probe surface and the inner face of a probe cover. The invention does not aid in the effort of helping to secure or fix the probe in an intended desired position. Nor does the invention describe a gel which varies in adhesion and viscosity over time.
[0017] U.S. Pat. No. 5,394,877 to Orr et al. describes a contact medium structure attachable to externally applied medical diagnostic devices for providing self-adherence of a medical device to the skin of a patient thereby eliminating the need for retaining belts or similar means. A contact medium is described that is inherently adhesive, hydrophilic, skin compatible, ultrasonic compatible and pressure sensitive to facilitate self-adhesion of the medical device to the patient's skin. The device of Orr et al. necessitates the use of a flexible support element which must be manually set in place to fix the ultrasound probe in its desired position. The inherently adhesive contact medium has a fixed adhesion. It does not allow for easy positioning of the transducer followed by a natural and automatic inherent increase in adhesion and viscosity to assist in holding the transducer in the desired position. Because the invention utilizes the flexible support element which holds a mesh-reinforced hydrogel film in place, it is not conducive to ultrasound guided procedures such as needle guided procedures as previously discussed.
[0018] U.S. Pat. No. 5,070,888 to Hon et al. details the use of a strong adhesive on the abdomen of a patient that forms a solid bond with the skin in order to secure the transducer to the patient. U.S. Pat. No. 4,920,966 to Hon et al. describes an adhesive layer applied to the surface of a disc-shaped transducer base in contact with the skin. Such an adhesive in these patents is sufficiently strong to maintain the transducer in place on the patient without the use of a belt. However, such a system is difficult to remove because the adhesive would bond to the skin of the patient and require the use of solvents for the removal of the transducer from the patient. The inherently adhesive contact medium has a fixed adhesion. It does not allow for easy positioning of the transducer followed by a natural and automatic inherent increase in adhesion and viscosity to assist in holding the transducer in the desired position.
[0019] U.S. Pat. No. 6,048,323 to Hon et al. describes the use of a hydrogel layer present on the lower surface of a fastening pads for attachment to the patient. The hydrogel is a mild adhesive which is sufficiently strong to provide the necessary fixation forces to fix the transducer support plate on the patient, but does not form a strong bond with the skin of the patient. The hydrogel is easily removed from the skin of the patient without the use of solvents. This hydrogel requires the use of an additional fastening pad, and does not experience the increase in adhesion over time that first allows positioning before aiding in anchoring the transducer in the desired position. It is also not suitable for guided injection procedures due to the use of the fastening pad.
[0020] In light of the aforementioned problems with current techniques, it would be advantageous to have an ultrasound coupling gel which initially allows for easy movement and positioning of the ultrasound transducer, and then inherently increases in viscosity and adhesion over time, assisting in fixing the probe to the skin in the desired position, all the while providing for consistent contact with the patient's skin to allow for proper transmission of the wave signal. Additionally, it would be advantageous to have the aforementioned product which allows for unimpeded ultrasound guided procedures such as needle injection, and the ability to intentionally remove or reposition the transducer if desired even after ultimate adhesion has been achieved.
SUMMARY OF THE INVENTION
[0021] The present invention relates to a variable adhesion ultrasound coupling gel. A reverse phase acoustic coupling gel initially allows easy movement and positioning of the ultrasound transducer before experiencing an inherent marked increase in viscosity and adhesion which assists in fixing the probe in place once the desired position is identified. Once ultimate adhesion is achieved, the gel will continue to allow intentional repositioning or removal of the transducer. The coupling gel allows for unimpeded ultrasound guided procedures such as ultrasound guided needle puncture. By first allowing the healthcare provider to easily position the ultrasound transducer, and then assisting in the fixation of the transducer in the desired position, the coupling gel enables a more effective, safer and shorter procedure in ultrasound guided procedures.
BRIEF DESCRIPTION OF THE FIGURES
[0022] FIG. 1 depicts the dependence of viscosity (cP) on temperature (° C.) of a solution of poloxamer 288 (BASF Pluronic® F98) (25% w/w) and Carbopol 981NF (Lubrizol®) (1% w/w) in a 50 mM tromethamine solution in purified water. The viscosity was recorded using a Brookfield DV-II+ Pro viscometer at 50 rpm.
[0023] FIG. 2 shows a rheological experiment illustrating the shear thinning nature of a solution of poloxamer 288 (BASF Pluronic® F98) (25% w/w) and Carbopol 981 NF (Lubrizol®) (1% w/w) in a 50 mM tromethamine solution in purified water using the Brookfield viscometer ranging from 50 rpm to 0.5 rpm at 31° C.
[0024] FIG. 3 depicts the dependence of viscosity (cP) on temperature (° C.) of a solution of poloxamer 407 (BASF Pluronic® F127) (20% w/w) and Carbopol 981NF (Lubrizol®) (1% w/w) in a 50 mM tromethamine solution in purified water. The viscosity was recorded using a Brookfield DV-II+Pro viscometer at 50 rpm.
[0025] FIG. 4 depicts a rheological experiment illustrating the shear thinning nature of a solution of poloxamer 407 (BASF Pluronic® F127) (20% w/w) and Carbopol 981NF (Lubrizol®) (1% w/w) in a 50 mM tromethamine solution in purified water using the Brookfield viscometer ranging from 50 rpm to 0.5 rpm at 31° C.
[0026] FIG. 5 depicts the dependence of viscosity (cP) on temperature (° C.) of a solution of poloxamer 407 (BASF Pluronic® F127) (22.5% w/w) and Carbopol 981NF (Lubrizol®) (1% w/w) in a 50 mM tromethamine solution in purified water. The viscosity was recorded using a Brookfield DV-II+ Pro viscometer at 50 rpm.
[0027] FIG. 6 depicts a comparison between three gels of the force required to move an object upon initial application and after 60 seconds. The data depicted on the left were gathered from experiments utilizing the following solution: poloxamer 407 (BASF Pluronic® F127) (22.5% w/w) and Carbopol 981NF (Lubrizol®) (1% w/w) in a 50 mM tromethamine solution in purified water. The data depicted in the middle were gathered from experiments utilizing the following solution: poloxamer 288 (BASF Pluronic® F98) (25% w/w) and Carbopol 981NF (Lubrizol®) (1% w/w), in a 50 mM tromethamine solution in purified water. The data depicted on the right were gathered from experiments utilizing commercially available Aquasonic® 100 (Parker Labs).
[0028] FIG. 7 depicts a representative pair of images visualized with Philips HD11XE at 12 MHz. The image in A was visualized using Aquasonic® 100; the image in B was visualized using Pluromed P288/CB981 gel.
[0029] FIG. 8 depicts a pair of images visualized with Philips HD11XE at 8 MHz (top) and a pair of images visualized with Philips HD11XE at 10 MHz (bottom). In both cases, the image in A was visualized using Aquasonic® 100; the image in B was visualized using Pluromed P288/CB981 gel.
[0030] FIG. 9 depicts a pair of images visualized with GE LOGIQe at 8 MHz (top) and a pair of images visualized with GE LOGIQe at 10 MHz (bottom). In both cases, the image in A was visualized using Aquasonic® 100; the image in B was visualized using Pluromed P288/CB981 gel.
[0031] FIG. 10 depicts a pair of images visualized with GE LOGIQe at 12 MHz (top) and a pair of images visualized with Sonosite MicroMAXX using the “Res” setting (bottom). In both cases, the image in A was visualized using Aquasonic® 100; the image in B was visualized using Pluromed P288/CB981 gel.
[0032] FIG. 11 depicts a pair of images visualized with Sonosite MicroMAXX using the “Gen” setting (top) and a pair of images visualized with Sonosite MicroMAXX using the “Pen” setting (bottom). In both cases, the image in A was visualized using Aquasonic® 100; the image in B was visualized using Pluromed P288/CB981 gel.
[0033] FIG. 12 depicts a pair of images visualized with Zonare at 10 MHz (top) and a pair of images visualized with Zonare at 17 MHz (bottom). In both cases, the image in A was visualized using Aquasonic® 100; the image in B was visualized using Pluromed P288/CB981 gel.
DESCRIPTION OF THE INVENTION
[0034] The device of this invention is a time- and temperature-sensitive variable adhesion ultrasound coupling gel. A reverse phase polymer is utilized as an ultrasound acoustic coupling gel. The coupling gel is initially in a low viscosity, low adhesion state when applied to the surface of the patient's skin, allowing the ultrasound transducer to be easily moved and positioned while identifying the desired location. The gel experiences an inherent increase in adhesion and viscosity when exposed to the skin for a period of time, providing a non-permanent adhesion to the surface of the skin and assisting in fixing the transducer in its intended location. The gel also experiences varying viscosity in response to varying shears applied to the gel. As the shear applied decreases, the viscosity of the gel increases, while increasing shear yields decreasing viscosity. This feature of the gel allows for intentional repositioning or removal of the ultrasound transducer after ultimate adhesion has been reached. The gel is easily cleaned from the skin without the use of solvents when the procedure is complete. The coupling gel also allows for unimpeded ultrasound guided procedures. By first allowing the healthcare provider to easily position the ultrasound transducer, and then assisting in the fixation of the transducer in the desired position, the coupling gel enables a more effective, safer and shorter procedure in ultrasound guided procedures. The coupling gel is biocompatible and its components are non-irritating.
[0035] The reverse phase polymer can include a poloxamer. The term “poloxamer” denotes a symmetrical block copolymer, consisting of a core of PPG polyoxyethylated to both its terminal hydroxyl groups, i.e. conforming to the interchangeable generic formula (PEG)X-(PPG)Y-(PEG)X and (PEO)X-(PPO)Y-(PEO)X. Each poloxamer name ends with an arbitrary code number, which is related to the average numerical values of the respective monomer units denoted by X and Y.
[0036] The term “reverse phase polymer” as used herein refers to a polymer that is typically encountered as a solution at ambient temperature, but which undergoes a gelation at or near physiological temperature. Reverse phase polymers include poloxamer 407 (BASF Pluronic® F127), poloxamer 188 (BASF Pluronic® F68), poloxamer 288 (BASF Pluronic® F98), poloxamer 338 (BASF Pluronic® F108), poly(N-isopropylacrylamide), poly(methyl vinyl ether), poly(N-vinylcaprolactam); and certain poly(organophosphazenes). See Bull. Korean Chem. Soc. 2002, 23, 549-554.
[0037] In general, the reverse phase polymers used in the methods of the invention, which become a viscous gel at or about skin surface temperature, can be dispelled onto the patient's skin in a low viscosity form resembling that of a liquid or free-flowing lower viscosity gel. The dispelled material once approaching skin surface temperature undergoes a transition from a liquid or free-flowing gel to a more viscous gel, thereby also experiencing an increase in adhesion. Additionally, the reverse phase polymer can be a shear-thinning material, in which the viscosity increases as the applied shear decreases, and conversely the viscosity decreases as the applied shear increases. The reverse phase polymers used in connection with the methods of the invention may comprise a block copolymer with reverse thermal gelation properties. The block copolymer can further comprise a polyoxyethylene-polyoxypropylene block copolymer such as a biodegradable, biocompatible copolymer of polyethylene oxide and polypropylene oxide. Also, the reverse phase polymer can include a therapeutic agent such as an antiseptic agent. The reverse phase polymer can also include additives to increase the ultimate adhesion of the gel. The reverse phase polymer can also include viscosity modifiers, such as sodium chloride, to adjust the viscosity of the gel. The reverse phase polymer can also include additives, such as preservatives or antimicrobials, to extend the shelf life of the gel.
[0038] Notably, poloxamer polymers (trade name Pluronic® polymers) have unique surfactant abilities and extremely low toxicity and immunogenic responses. These products have low acute oral and dermal toxicity and low potential for causing irritation or sensitization, and the general chronic and sub-chronic toxicity is low. In fact, Pluronic® polymers are among a small number of surfactants that have been approved by the FDA for direct use in medical applications and as food additives (BASF (1990) Pluronic® & Tetronic® Surfactants, BASF Co., Mount Olive, N.J.). Recently, several Pluronic® polymers have been found to enhance the therapeutic effect of drugs, and the gene transfer efficiency mediated by adenovirus. (March K L, Madison J E, Trapnell B C. “Pharmacokinetics of adenoviral vector-mediated gene delivery to vascular smooth muscle cells: modulation by poloxamer 407 and implication for cardiovascular gene therapy” Hum Gene Therapy 1995, 6, 41-53).
[0039] The molecular weight of the reverse phase polymer is preferably between about 1,000 and about 50,000, more preferably between about 5,000 and about 35,000. Preferably the polymer is in an aqueous solution. For example, typical aqueous solutions contain about 10% to about 50% polymer, preferably about 20% to about 40%. The molecular weight of a suitable reverse phase polymer (such as a poloxamer) may be, for example, between about 5,000 and about 25,000, and more particularly between about 7,000 and about 20,000.
[0040] The pH of the reverse phase polymer formulation is, generally, about 3.0 to about 8.0, more preferably between about 5.0 and about 7.8, which are suitable pH levels for exposure to mammalian skin. The pH level may be adjusted by any suitable acid or base, such as hydrochloric acid or sodium hydroxide.
[0041] Suitable reverse phase polymers include polyoxyethylene-polyoxypropylene (PEO-PPO) block copolymers. Three examples are Pluronic® F127, F98, and F108, which are PEO-PPO block copolymers with molecular weights in the range of about 12,600 to about 14,600. Each of these compounds is available from BASF of Mount Olive, N.J. Pluronic® F98 at about 12-45% concentration in saline tromethamine solution in purified water (Tris) is an example of a suitable reverse phase polymeric material. Pluronic® F108 at about 12-45% concentration in Tris is another example of a suitable material. Pluronic® F127 at about 12-45% concentration in Tris is another example of a suitable material. Low concentrations of dye (such as crystal violet), hormones, therapeutic agents, fillers, antiseptics and antibiotics can be added to the reverse phase polymer. In general, other biocompatible, biodegradable PEO-PPO block copolymers that exist as a gel at skin surface temperature and as a liquid or low viscosity gel at below skin surface temperature may also be used according to the present invention.
[0042] The average molecular weights of the poloxamers range from about 1,000 to greater than 16,000 daltons. Because the poloxamers are products of a sequential series of reactions, the molecular weights of the individual poloxamer molecules form a statistical distribution about the average molecular weight. In addition, commercially available poloxamers contain substantial amounts of poly(oxyethylene) homopolymer and poly(oxyethylene)/poly(oxypropylene) diblock polymers. The relative amounts of these byproducts increase as the molecular weights of the component blocks of the poloxamer increase. Depending upon the manufacturer, these byproducts may constitute from about 15 to about 50% of the total mass of the polymer.
[0043] The reverse phase polymers may be purified using a process for the fractionation of water-soluble polymers, comprising the steps of dissolving a known amount of the polymer in water, adding a soluble extraction salt to the polymer solution, maintaining the solution at a constant optimal temperature for a period of time adequate for two distinct phases to appear, and separating physically the phases. Additionally, the phase containing the polymer fraction of the preferred molecular weight may be diluted to the original volume with water, extraction salt may be added to achieve the original concentration, and the separation process repeated as needed until a polymer having a narrower molecular weight distribution than the starting material and optimal physical characteristics can be recovered.
[0044] Additives to increase the ultimate adhesion of the gel can include suitable high molecular weight polyacrylic acid polymers such as Carbopols® from The Lubrizol Corporation (formerly Noveon, Inc., Cleveland, Ohio). Suitable Carbopols® include Carbopol® 981 NF, Carbopol® 980NF, Carbopol® 971 NF, Carbopol® 974NF, Carbopol® 941 NF, Carbopol® 940NF. Carbopol® 981 NF is commonly used for topical applications. The average viscosity of the Carbopols® ranges from about 4,000 to about 65,000 cP, and preferably between about 4,000 and about 30,000 cP, at about 0.5% wt concentration and about 7.5 pH.
[0045] The preferred embodiment of the ultrasound coupling gel includes poloxamer 288 and Carbopol® 981 NF in a solution of purified water or tromethamine in purified water (Tris). The concentration of poloxamer 288 ranges from about 10% (w/w) to about 50% with the preferred range between about 20% and about 40%. The concentration of Carbopol® 981 NF ranges from about 0.1% to about 3% with the preferred range between about 0.5% and about 2% (wt/wt). The balance of the solution is purified water, tromethamine in purified water, or a buffer solution.
[0046] Other embodiments of the reverse phase polymer include poloxamer 407 (Pluronic® F127), poloxamer 188 (Pluronic® F68), poloxamer 288 (Pluronic® F98), poloxamer 338 (Pluronic® F108), poly(N-isopropylacrylamide), poly(methyl vinyl ether), poly(N-vinylcaprolactam), certain poly(organophosphazenes), and other reverse phase polymers. These other embodiments can include adhesion additives such as Carbopol® 981 NF, Carbopol® 980NF, Carbopol® 971NF, Carbopol® 974NF, Carbopol® 941NF, and Carbopol® 940NF. The concentration of reverse phase polymer ranges from about 10% (w/w) to about 50% with the preferred range between about 20% and about 40%. The concentration of adhesion additives ranges from about 0.1% to about 3% with the preferred range between about 0.5% and about 2% (wt/wt). The balance of the solution can be purified water, saline solution, phosphate buffered saline solution, or tromethamine in purified water (Tris).
[0047] Still other embodiments may include reverse phase polymers that have undergone the purification/fractionation process described above.
[0048] Still other embodiments may include any additives to increase ultimate adhesion of the coupling gel, including but not limited to: polycarbophil; sodium alginate; sodium chloride; sodium dihydrogen phosphate; sodium monohydrogen phosphate; protamine; and, polysaccharide.
[0049] Still other embodiments may include any additives that would act to modify the viscosity of the reverse phase polymer.
[0050] Still other embodiments may include any additives that would not eliminate the reverse phase thermosensitive properties of the gel as described in this invention.
[0051] The transition from the low viscosity/low adhesion state to the higher viscosity/higher adhesion state will occur between about 1 and about 180 seconds, and preferably between about 5 and about 90 seconds,
[0052] In procedures where an ultrasound probe is covered by a protective sheath as previously mentioned, the ultrasound coupling gel of the present invention not only provides acceptable lubricating and/or acoustic coupling properties on the outside of the protective sheath but also within the sheath (i.e. between the ultrasound probe and the sheath).
[0053] It is also within the scope of the present invention to apply the inventive couplant directly to an organ or tissue, and then proceed with ultrasound imaging by contacting the couplant-coated organ or tissue with the active area of a transducer. It is to be understood that while the present invention has been discussed with reference to medical ultrasound applications within and on a human body, it is not to be limited thereto. The present invention is also contemplated to be applicable within other animals such as in veterinary ultrasound.
[0054] While the invention has been described with reference to preferred embodiments it is to be understood that the invention is not limited to the particulars thereof. The present invention is intended to include process, formulation and modifications which would be apparent to those skilled in the art to which the subject matter pertains without deviating from the spirit and scope of the specification.
EXEMPLIFICATION
[0055] The invention now being generally described, it will be more readily understood by reference to the following examples, which are included merely for purposes of illustration of certain aspects and embodiments of the present invention, and are not intended to limit the invention.
Example 1
[0056] Poloxamer 288 (BASF Pluronic® F98) and Carbopol 981 NF (Lubrizol®) were added to a solution of tromethamine (50 mM in purified water, pH 7.3) to create a solution of 25% (w/w) P288, 1% Carbopol 981NF, and 74% tromethamine buffer. Viscosity was recorded over a temperature range of 15° C. to 37° C. using a Brookfield DV-II+ Pro viscometer set at 50 rpm. The resulting viscosity vs. temperature curve is presented in FIG. 1 . FIG. 1 displays the reverse-thermosensitive nature of the solution due to the inclusion of P288. The peak viscosity of 9,366 cP at 25° C. was 427% that of the viscosity at 15° C. This significant increase in viscosity, along with the increased bioadhesion due to the presence of Carbopol, resulted in a less slippery surface for the ultrasound probe, thus reducing unwanted probe movement. With a peak viscosity encountered above room temperature, the gel was less viscous upon initial application and became more viscous upon warming due to the skin's temperature.
[0057] Rheology was then performed using the Brookfield viscometer ranging from 50 rpm to 0.5 rpm at 31° C. The data are presented in FIG. 2 . FIG. 2 displays the shear thinning nature of the solution. As the shear increased due to increasing rate of rotation of the viscometer, the viscosity decreased. This effect is significant in the ultrasound application. As the probe was brought to rest upon identifying the target location, the lack of shear stress on the gel yielded a more viscous gel. If the user initiated probe movement to fine-tune the probe location, the viscosity of the gel decreased, thus allowing easier movement of the probe.
Example 2
[0058] Poloxamer 407 (BASF Pluronic® F127) and Carbopol 981NF (Lubrizol®) were added to a solution of tromethamine (50 mM in purified water, pH 7.3) to create a solution of 20% (w/w) P407, 1% Carbopol 981NF, and 79% tromethamine buffer. Viscosity was recorded over a temperature range of 10° C. to 37° C. using a Brookfield DV-II+ Pro viscometer set at 50 rpm. The resulting viscosity vs. temperature curve appears in FIG. 3 . FIG. 3 displays the reverse-thermosensitive nature of the solution due to the inclusion of P407. The peak viscosity of 7,636 cP at 20° C. was 358% that of the viscosity at 10° C. This significant increase in viscosity, along with the increased bioadhesion due to the presence of carbopol, resulted in a less slippery surface for the ultrasound probe, thus reducing unwanted probe movement. Also significant was the point of peak viscosity. At 20° C., roughly room temperature, the gel has already reached its higher viscosity state, compared to the previous example in which the peak viscosity is reached only after the solution is warmed to 25° C.
[0059] Rheology was then performed using the Brookfield viscometer ranging from 50 rpm to 0.5 rpm at 31° C. The data are presented in FIG. 4 . FIG. 4 displays the shear thinning nature of the solution. As the shear increased due to increasing rate of rotation of the viscometer, the viscosity decreased. This is significant in the ultrasound application. As the probe was brought to rest upon identifying the target location, the lack of shear stress on the gel yielded a more viscous gel. If the user initiated probe movement to fine-tune the probe location, the viscosity of the gel decreased, thus allowing easier movement of the probe.
Example 3
[0060] Poloxamer 407 (BASF Pluronic® F127) and Carbopol 981NF (Lubrizol®) were added to a solution of tromethamine (50 mM in purified water, pH 7.3) to create a solution of 22.5% (w/w) P407, 1% Carbopol 981NF, and 76.5% tromethamine buffer. Viscosity was recorded over a temperature range of 10° C. to 37° C. using a Brookfield DV-II+ Pro viscometer set at 50 rpm. The resulting viscosity vs. temperature curve is presented in FIG. 5 . FIG. 5 displays the reverse-thermosensitive nature of the solution due to the inclusion of P407. The peak viscosity of 7,826 cP at 20° C. was 708% that of the viscosity at 10° C. This significant increase in viscosity, along with the increased bioadhesion due to the presence of carbopol, resulted in a less slippery surface for the ultrasound probe, thus reducing unwanted probe movement. Also significant is the point of peak viscosity. At 20° C., roughly room temperature, the gel has already reached its higher viscosity state. This is contrasted with the first example, in which the peak viscosity is reached only after the solution is warmed to 25° C.
Example 4
[0061] The force required to move a weighted plastic cylinder, upon initial application and then after 60 seconds, was compared for three different gels. Poloxamer 407 (BASF Pluronic® F127) and Carbopol 981NF (Lubrizol( ) were added to a solution of tromethamine (50 mM in purified water, pH 7.3) to create a solution of 22.5% (w/w) P407, 1% Carbopol 981NF and 76.5% tromethamine buffer solution for the first gel. The second gel comprised poloxamer 288 (BASF Pluronic® F98) and Carbopol 981 NF (Lubrizol®) in a solution of tromethamine (50 mM in purified water, pH 7.3). This created a solution of 25% (w/w) P288, 1% carbopol 981NF, and 74% tromethamine buffer solution. Aquasonic® 100 (Parker Labs) was purchased and was the third gel tested. A 5.5-cm diameter plastic cylinder was loaded to achieve a total weight of 117.5 grams. Four milliliters of each sample were applied to the skin and the loaded cylinder was placed on the gel. A scale (American Weigh Scales H11) with the ability to measure forces from 0.005 lbs to 11 lbs was used to measure the maximum force required to move the cylinder over a length of 2 inches. This was performed upon initial application of the gel to the skin and again after 60 seconds, a sufficient amount of time for the gel to warm to skin temperature. Twelve pairs of measurements (T=0 and T=60 seconds) were collected for P288 25%/CB981NF 1%/Tris 74%. Ten pairs of measurements (T=0 and T=60 seconds) were collected for P407 22.5%/CB981NF 1%/Tris 76.5%. Eight pairs of measurements (T=0 and T=60 seconds) were collected for Aquasonic 100. The average force required to move the cylinder for each gel is seen in FIG. 6 .
[0062] The average force at T0 required to move the cylinder through the P407 22.5%/CB981NF 1% gel is 0.34 lbs. At T60, the force is 0.62 lbs, 81% higher. The average force at T0 required to move the cylinder through the P288 25%/CB981 NF 1% gel is 0.17 lbs. At T60, the force is 0.38 lbs, 128% higher. The average force at T0 required to move the cylinder through the Aquasonic 100 gel is 0.15 lbs. At T60, the force is 0.19 lbs, 22% higher. P288 25%/CB981NF 1% yielded an initial force sufficiently comparable to Aquasonic, and yet the force required increased substantially upon warming, thus aiding in the reduction of unwanted probe movement.
Example 5
[0063] Two gels were compared in their ability to transmit ultrasound waves. An ex vivo model was designed to simulate an ultrasound-guided peripheral nerve block procedure, in which a needle is inserted towards a target under ultrasound visualization. A turkey breast was used as a phantom. Poloxamer 288 (BASF Pluronic® F98) and Carbopol 981NF (Lubrizol®) were added to a solution of tromethamine (50 mM in purified water, pH 7.3) to create a solution of 25% (w/w) P288, 1% Carbopol 981NF, and 74% tromethamine buffer solution. Commercially available Aquasonic® 100 (Parker Labs) was purchased. Four different ultrasound systems were used with different frequency settings. The 11 ultrasound system/frequency setting iterations evaluated were:
Sonosite MicroMAXX—L38 probe
‘Res’ ‘Gen’ ‘Pen’
Zonare—L10-5 probe
10 MHz 17 MHz
GE LOGIQe—12L probe
8 MHz 10 MHz 12 MHz
Philips HD11XE—L12-3 probe
8 MHz 10 MHz 12 MHz
[0079] The P288/CB981 gel was allowed to come to temperature in a 37° C. water bath before being applied to the turkey breast. An image was captured by an experienced anesthesiologist for both gels for each of the 11 ultrasound system/frequency setting iterations. The images (depicted in FIGS. 7-12 ) were then evaluated by 10 blinded evaluators who rated the image quality for each pair as follows:
a. Sample A is a better image b. Sample B is a better image c. There is no clinical difference between images A and B
[0083] A representative image pair is the Philips HD11XE at 12 MHz ( FIG. 7 ). The images are clinically indistinguishable. In both images, a block needle is clearly visualized entering the tissue from the upper right corner of the image. Muscle appears the same in both images with very good resolution of fine internal structure, while a brightly echogenic fascial plane is crisply defined in both images. Deeper bony and fascial structures are equally visualized in both images. Any very slight differences in the images can be attributed to subtle differences in probe position relative to the specimen.
[0084] The results of the comparisons by the 10 blinded evaluators are seen below in Table 1. If Sample A (Aquasonic 100) was preferred, a score of −1 is entered. If Sample B (P288 25%/CB981NF 1%) was preferred, a score of +1 is entered. If no clinical difference was found, a score of 0 is entered. Eight out of 10 reviewers indicated that, over the spectrum of all samples, Sample B (P288 25%/CB981NF 1%) provided a preferred image. Two out of ten reviewers indicated that, over the spectrum of all samples, there was no clinical difference between the two samples. Of the 110 total sample pair evaluations, Sample A (Aquasonic 100) was preferred 25.5% of the time, Sample B (P288 25%/CB981NF 1%) was preferred 42.7% of the time, and no clinical difference was found 31.8% of the time.
[0000]
TABLE 1
Rev
Rev
Rev
Rev
Rev
Rev
Rev
Rev
Rev
Rev
Avg by
System/Frequency
1
2
3
4
5
6
7
8
9
10
sample
Philips HD11XE - 8 MHz
0
1
−1
1
1
1
1
0
−1
1
0.40
Philips HD11XE - 10 MHz
1
1
1
1
1
1
1
0
1
1
0.90
Philips HD11XE - 12 MHz
1
0
0
0
1
−1
0
0
0
0
0.10
GE LOGIQe - 8 MHz
1
−1
0
0
1
1
1
1
−1
−1
0.20
GE LOGIQe - 10 MHz
−1
1
−1
1
−1
1
0
1
1
1
0.30
GE LOGIQe - 12 MHz
−1
−1
−1
0
−1
−1
0
0
−1
1
−0.50
Sonosite MicroMAXX - Res
1
1
0
0
1
0
0
0
1
0
0.40
Sonosite MicroMAXX - Gen
1
1
1
0
0
1
1
1
1
0
0.70
Sonosite MicroMAXX - Pen
1
−1
1
0
0
1
0
0
1
1
0.40
Zonare - 10 MHz
−1
−1
0
0
−1
1
−1
−1
−1
0
−0.50
Zonare - 17 MHz
1
−1
0
0
−1
−1
−1
−1
0
−1
−0.50
Average by Reviewer
0.36
0.00
0.00
0.27
0.09
0.36
0.18
0.09
0.09
0.27
Average of Total
0.17
INCORPORATION BY REFERENCE
[0085] All of the U.S. patents and U.S. published patent applications cited herein are hereby incorporated by reference.
EQUIVALENTS
[0086] Those skilled in the art will recognize, or be able to ascertain using no more than routine experimentation, many equivalents to the specific embodiments of the invention described herein. Such equivalents are intended to be encompassed by the following claims.
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One aspect of the present invention relates to a method of ultrasonography, utilizing a gel comprising a reverse phase polymer which facilitates the transmission of high-frequency sound waves. Further, the inherent properties of the reverse phase polymer result in increased adhesion at higher temperatures, thereby helping to maintain the desired position of the ultrasound probe until the user intends to adjust the probe's position. In certain embodiments, the method is utilized in a medical procedure in which stability of an ultrasound probe or transducer in an intended desired position can improve the outcome or increase the efficiency of the procedure. In certain embodiments, the gel further comprises an additive to increase the ultimate adhesion of the gel. In still other embodiments, the gel can be used on the skin, on a protective sheath encasing an ultrasound probe, or between the sheath and the probe, or any or all of them.
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FIELD OF THE INVENTION
This invention relates to hydrocarbon-based fuels, especially diesel fuels, having improved ignition and combustion characteristics, or cetane ratings, by the addition of a peroxide-type compound.
BACKGROUND OF THE INVENTION
Hydrocarbon distillates and residue-containing oils having characteristics which render them otherwise suitable for use as fuels for compression-ignition or diesel engines, or other atomising or vaporising-type burners, frequently have igition characteristics that render them unsuitable or only poorly suitable for such use. Fuels that have poor ignition characteristics, i.e., relatively high spontaneous ignition temperatures, exhibit an undesirably long ignition lag, between the time the fuel is injected into a zone of combustion and the time when the fuel ignites. In diesel engines, for example, a large ignition lag results in combustion of the fuel and the development of pressure over an improper portion of the crank angle period and piston stroke, resulting in knocking, rough engine operation, incomplete combustion in the combustion zone, power loss, and ultimately detriment to the engine.
To overcome these ignition or combustion problems, the fuel may be refined to produce a higher proportion of straight chain hydrocarbons similar to the original industry standard, cetane. The ignition quality of a diesel fuel is normally expressed in terms of its cetane number. The cetane number of a given fuel is defined as the percent proportion of cetane (a fast-burning C 16 paraffinic constituent) in a α-methylnaphthalene (a slow-burning aromatic material) that will match the performance of the fuel at the same compression ratio in a standard test engine.
Various agents, including nitrates such as 2-ethylhexyl nitrate, have been used to improve cetane ratings. Certain nitrate esters are described for this purpose in EP-A-0146381. However, nitrates can give rise to NO x emissions in exhaust, and this is environmentally undesirable.
Peroxides have been widely used as free radical inhibitors (curing agents) for the polymer industry. Some have been proposed as cetane improvers. For example Kirsch et al, Combust. Flame 43 (1981) 11-21, describe the use of di-tert-butyl peroxide as well as certain nitrates for this purpose.
U.S. Pat. No. 3,468,962 describes the preparation of "peroxyacetals and peroxyketals" of the formula R 1 OO--CR 2 R 3 --OR 4 from alkylidenediperoxides of the formula R 2 R 3 C(OOR 1 ) 2 . The latter are in fact perketals as the term is now understood and as it is used herein. CR 2 R 3 can be a cyclaliphatic radical. The products are said to be useful as agents for improving the cetane number of gasolines.
SUMMARY OF THE INVENTION
According to the present invention, the cetane value of a hydrocarbon-based fuel is increased by the addition of a minor amount of a perketal of the formula R 2 R 3 C(OOR 1 ) 2 wherein R 1 is a C 4-10 tertiary alkyl group and R 2 and R 3 together with the attached C atom from a cyclalkane ring optionally substituted by one or more C 1-4 alkyl radicals or other essentially inert substituents, such as one or more halogen atoms, or the like.
DESCRIPTION OF THE INVENTION
The fuel is, say, petroleum. It is preferably a diesel fuel, i.e., of the type for use in diesel engines and other atomising or vaporising type burners. By "diesel types", "fuel compositions boiling in the diesel range", or similar language, is meant those petroleum fractions from which the fuel is derived which are useful as fuel oil, gas oil and diesel oil and which distill above the kerosene fraction and below the lubricating oil fraction, that is, between about 250° C. and about 400° C.
The perketals used in the invention are employed in hydrocarbon-based fuels in an amount sufficient to improve the ignition quality or cetane rating of the fuel. This amount will vary somewhat according to the nature of the fuel, such as the base stock from which it is formed, and properties which may be varied by refining of the fuel. These cetane improving agents can be added to diesel fuel fractions as single components, or a mixture of several of these agents can be used. Normally, a noticeable improvement in the ignition quality of a fuel oil will be obtained by incorporating therein as little as 0.05% per volume of the perketal, and the use of about 0.5 to about 2.5% by volume will result in a marked improvement. The improvement in cetane rating per unit volume increment of nitrate esters often gradually declines somewhat at proportions in the range of 0.5 to 1% by volume, but that effect is not seen in this case.
Perketals conforming to the above general formula can be employed as cetane-improving agents where each of the designated alkyl groups includes a greater number of carbon atoms than represented above. As the size of the molecule and the carbon content increase much beyond what is defined by the above formula, the improvement in cetane rating may diminish. In general, as the carbon content decreases, the cetane rating improvement increases. Relatively small molecules, or those containing relatively small amounts of carbon, present increased hazards owing to the volatility and the relatively explosive character of some such compounds. Thus the compounds represented by the above formula and defined pendant radicals represent a compromise between optimum cetane improvement and practical handling and storage considerations of the cetane improving agents themselves. It is preferred that R 1 is tert-butyl and/or that CR 2 R 3 is cyclohexylidene optionally substituted by one or more CH 3 groups. Particularly preferred perketals are 1,1-bis(tert-butylperoxy)cyclohexane and 1,1-bis(tert-butylperoxy)-3,3,5-trimethylcyclohexane.
The perketals used in the invention are known per se, or can be prepared by known methods. Perketals of the type used in this invention are described as starting materials in U.S. Pat. No. 3,468,962, and methods for their preparation are described therein, which disclosures are incorporated herein by reference.
The cetane-improving agents used in the present invention can be incorporated in the hydrocarbon-based fuels disclosed herein in any suitable manner. These perketals are normally soluble in paraffinic as well as aromatic hydrocarbons in the proportions disclosed herein and, therefore, can be incorporated directly in the fuels. However, since the cetane-improving agents of the present invention are normally used in very small amounts, it may be preferable, from the standpoints of facilitating formation of a homogeneous mixture and also accurately measuring the correct proportions, to employ the cetane-improving agents in the form of a concentrated or stock solution in either a solvent which is compatible with the fuel, or the fuel itself.
The hydrocarbon-based fuel compositions of this invention may contain, in addition to the perketal, other additives to improve the fuels in one or more respects. For example, the fuel compositions of this invention may also contain oxidation inhibitors, anti-foam agents and other ignition quality or combustion-improvement agents.
The following examples illustrate the invention which should not be regarded as limiting the invention in any way.
EXAMPLES
A fuel having a cetane value of 45 was treated by the addition of various amounts of 1,1-bis(tert-butylperoxy)cyclohexane and 1,1-bis(tert-butylperoxy)-3,3,5-trimethylcyclohexane, hereinafter abbreviated as DBPCH and DBPTMCH. The results are tabulated below. The cetane values are averages of three tests in each case. The data indicate that both perketals give an increase of nearly 20 in cetane rating, at a concentration of 1% v/v. Under the same conditions, 1% of the acyclic analogue 2,2-bis(tert-butylperoxy)butane increased the cetane value by 11, to 56, 1% di-tert-butyl peroxide by about 13 to 58.4, and 1% 2-ethylhexyl nitrate by slightly more.
______________________________________ Amount wrt FuelAdditive (% v/v) Cetane Rating______________________________________ -- -- 45DBPCH 0.12 51.5DBPCH 0.25 54.1DBPCH 0.30 54.7DBPCH 0.50 57.1DBPCH 0.77 58.7DBPCH 1.01 64.1DBPCH 1.29 66.7DBPCH 1.81 71.5DBPTMCH 0.05 48.1DBPTMCH 0.1 50.5DBPTMCH 0.2 50.7DBPTMCH 0.4 55.8DBPTMCH 1.0 62.7______________________________________
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A hydrocarbon-based fuel to which has been added a minor amount, sufficient to increase the cetane value of the fuel, of a perketal of the formula
R.sup.2 R.sup.3 C(OOR.sup.1).sub.2
wherein R 1 is a C 4-10 tertiary alkyl group and R 2 and R 3 together with the attached C atom form a cycloalkane ring optionally substituted by one or more C 1-4 alkyl radicals or other essentially inert substituents, such as halogen.
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BACKGROUND OF THE INVENTION
[0001] 1. Field of Invention
[0002] The invention relates to a control system of a vehicle, especially a tractor, equipped with a Continuously Variable Transmission (CVT) of the hydrostatic-mechanical split type which includes a hydraulic drive circuit in which a hydraulic pump supplies pressurised fluid to a hydraulic motor.
[0003] 2. Description of Related Art
[0004] A hitch, such as a three-point linkage is one known arrangement used to attach implements to a drawing vehicle, for example an agricultural tractor. The implement may be fully mounted or semi-mounted on the tractor whereby a semi-mounted implement has a wheel engaging with the ground during soil operation while a fully-mounted implement puts all its load on the three-point linkage.
[0005] Three point linkages most frequently consist of two lower lifting arms to which an implement is attached. The lower lifting arms can be pivoted by respective hydraulic actuating cylinders to adjust the height position of the implement relative to the tractor. Furthermore, these lower lifting arms may be manually adjusted by length to be appropriate for an implement to be attached. An additional top link connects the implement to the tractor above the lower lifting arms. This top link is used to pivot the implement about a horizontal transverse axis and is adjustable by means of a threaded connection, or a hydraulic cylinder.
[0006] Alternative designs of three-point linkages are known, such as the arrangements shown in U.S. Pat. No. 6,321,851, US 2003/217852 and U.S. Pat. No. 5,997,024 in which the lower links are replaced by two or four variable length hydraulic rams. This variable length ram arrangement enables multi axis movement of any implement attached to the linkage.
[0007] To control the three-point linkage, modern tractors are mainly equipped with electronic linkage control systems to improve work quality and operator comfort during operation.
[0008] Such electronic linkage control systems operate in three well known modes:
[0009] Position Control:
[0010] In general, the tractor speed is kept constant by a speed control system and the position of the lower lifting arms is sensed directly or indirectly so that the working depth of the implement in the soil can be adjusted whilst the speed of the tractor is kept constant.
[0011] Draft Control:
[0012] The implement is raised and lowered in the soil depending on the draft force applied by the implement to reduce fuel consumption, avoid engine stall or avoid damage of the implement or tractor. Again, vehicle speed is kept constant. If the implement is lowered into the ground an initial draft is applied defining a zero level. The operator can then set a value representing a force increase which means that the operator can decide how fast the implement is lifted when a small force increase or a large force increase occurs. The value of the force entered by the operator does not represent an exact value of the force applied, e.g. 5 kN, but defines the responsiveness of the draft control. The objective of this function is to move the implement while avoiding excessive draft or pull force variations. Therefore, a draft force sensor, typically in the form of a draft force sensing pin which connects the lower lifting arms to the tractor chassis is used to measure the horizontal load applied to the tractor by the implement.
[0013] Intermix of Position/Draft Control:
[0014] This control arrangement, as its name implies, is a mixture of position and draft control in which a draft control system can only lift the implement within a limited range of positions. This function is provided to avoid excessive movement of the implement in the soil resulting in poor working quality. Again, vehicle speed is kept constant by a speed control system.
[0015] Only the draft control and intermix mode (both referred to as drag modes) operate under measurement of the drag force. Generally, deactivating the drag modes results in that the system enters the position mode with no drag force influencing the lifting heights. It may however be difficult to install a draft force sensing pin due to the complex three-dimensional geometry of a linkage. Further, the sensing pins may become dirty or damaged and thus may not function properly. Accordingly, a control system which does not rely on sensing pins is preferred.
[0016] A linkage control based on CVT parameters can result in that the control system moves the position of the linkage over a wide vertical displacement range as a reaction to the drag force. Various situations have been identified in which the movement of the linkage should be limited in drag mode, since otherwise the draft control will cause the implement to crash to the ground, or cause the linkage to collide with the wheels of the tractor, or the drawbar of an trailer.
[0017] For example, if the draft force rises continuously because a plough in the ground has hit a rock, the draft control will move the linkage up until the highest end position is reached. Other situations have been identified where an increasing, or decreasing draft force will cause vertical displacement of the linkage and any attached implement to the lowest or highest position. Detecting these situations can be quite difficult. Some implements are simply towed by attachment to a ball hitch rather than being mounted to the linkage, with actuators on the implement controlling operating conditions of the implement based on information received from the tractor, for example via a CAN-BUS link, or ISOBUS.
[0018] In the case where an implement is attached to a ball hitch on the tractor, or a when a tow bar is attached to the tractor, that is, the linkage is not used, a drag force determined by the CVT would deliver a significant change of drag signal when the roll of the tractor changes, or the vehicle travels uphill, or downhill or during acceleration. Under normal circumstances, this would cause the linkage to move, and thus when a tow bar is attached would cause it, or the linkage to collide with the tow bar.
[0019] In the case where an implement is being transported in a lifted position, the operator is ordinarily responsible for deactivating the draft or intermix mode manually when travelling along a road with an implement held in a lifted position. If this is not done the drag force determined by the CVT delivers a significant change of drag signal when the roll of the tractor changes, or the vehicle travels uphill, or downhill or during acceleration. This could result in the implement to be lowered and crashing to the ground.
[0020] In the case where an implement is attached which is not in contact with the ground during operation, for example fertiliser spreaders and sprayers, the CVT delivers a significant change of drag signal when the roll of the tractor changes, or the vehicle travels uphill, or downhill or during acceleration. This would ordinarily result in the implement being highered which is not intended, or lowered which is also not intended and may be dangerous if not expected.
[0021] In the case of acceleration to a new speed regardless of the position of the implement, the change of drag signal may result in unintentional movement of the linkage. The faster the vehicle is going, the greater is the risk of damage through unintentional movement of the linkage.
OVERVIEW OF THE INVENTION
[0022] It is an aim of the invention to provide a safer draft control function on a tractor which limits the movement of the linkage as a result of a change in draft signal. It is a further object of the invention to provide a control system which avoids the use of draft force sensing pins.
[0023] In accordance with the invention there is provided a control system for a tractor having a transmission with a hydraulic drive circuit in which a hydraulic pump supplies pressurised fluid to a hydraulic motor, wherein said control system controls an operating condition of an implement attached to the tractor and said control system comprises a pressure sensing means which senses the pressure in the hydraulic drive circuit and provides a signal which is indicative of the current pull force necessary to pull the implement, the system further comprising a control means which receives the pressure signal and a second signal relating to the speed of the tractor and adjusts the current position of the implement to a new position when said pressure signal varies, characterised in that the new position lies within a pre-determined position range dependent on the second signal in order to maintain an optimal, yet safe operating condition of the implement.
[0024] By limiting the vertical displacement of the linkage, even though the draft force is changing, the control system prevents damage to the implement, or the tractor.
[0025] The higher the speed of the tractor, the narrower the pre-determined position range is. This thus improves safety at higher speeds.
[0026] Preferably, the pre-determined position range is effected when attachment of the implement is detected.
[0027] Preferably, the new position of the implement is effected by controlling movement of a linkage to which the implement is attached.
[0028] More preferably, the linkage is a three point linkage.
[0029] For linkage mounted implements, a control system can control the position of an implement attachment linkage relative to the tractor via an actuator means which raises and lowers the implement linkage relative to the tractor. Such a control system can be used to control a linkage which is attached to the rear and/or front of the tractor. No additional draft force sensors are involved as the variation of the pull force of the linkage is determined from the variation in the hydraulic drive circuit pressure. Also the need to use existing pin sensors is avoided.
BRIEF DESCRIPTION OF THE DRAWINGS
[0030] The present invention will now be described, by way of example only, with reference to the accompanying drawings in which:—
[0031] FIG. 1 diagrammatically shows a side view of a tractor with a linkage control system embodying the present invention,
[0032] FIG. 2 diagrammatically shows a driveline of a tractor with a hydrostatic mechanical CVT and having a linkage control system embodying the present invention,
[0033] FIG. 3 diagrammatically shows in more detail the hydrostatic mechanical CVT portion of the driveline of FIG. 2 , and
[0034] FIG. 4 shows the forces acting between a tractor wheel and the ground.
DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS
[0035] Referring to the drawings, an agricultural tractor 1 has a driveline 2 having a combustion engine 3 , a flywheel 4 , a continuously variable transmission, or CVT, T of the hydrostatic-mechanical split type and a rear axle housing 300 . Combustion engine 3 is connected to the CVT, T by chassis part 310 .
[0036] A three-point linkage 400 is attached to the rear axle housing 300 and mainly consists of two lower lifting arms 401 to which an implement is attached. A plough 500 with ground engaging means 501 is attached to lower lifting arms 401 . An additional top link 402 connects the implement 500 to the tractor 1 . The top link 402 is of a hydraulic type adjustable in length to adjust the inclination of the plough 500 with the ground. The lower lifting arms 401 can be pivoted about axis A by respective hydraulic actuating cylinders 403 which move rocker arm 404 and lift rod 405 . The height of the lifting arms can thus be changed by pivoting the lifting arms about axis A and this movement is hereafter referred to as the vertical displacement of the lifting arms. The hydraulic actuating cylinders 403 are supplied with an actuating fluid by a control valve 406 . Control valve 204 controls which chamber 403 a (to lift the implement) or chamber 403 b (to lower the implement) of the hydraulic actuating cylinders 403 is charged with fluid. Control valve 406 is connected to a pump 407 which is driven by combustion engine 3 and connected with a fluid tank 408 .
[0037] The position of the lower lift arms 401 is indirectly measured by a position sensor 409 which senses the position of a cam 410 attached to rocker arm 404 .
[0038] An additional pressure sensor 411 is provided to measure the fluid pressure in the chamber 403 a of the hydraulic actuating cylinders 403 . The fluid in chamber 403 a is compressed when the implement weight is fully taken up by the three-point linkage 400 and therefore a pressure increase indicates movement of the implement to a high position for transportation.
[0039] A tractor control unit 13 is provided to control various functions of the vehicle. The control unit 13 is electronically connected to various components via CAN-BUS, for example, the transmission and display and input devices. The control unit 13 also contains software to drive the electronic linkage control system. The control unit 13 is connected to an input and display device 13 a in the tractor cab to receive input from the operator and to show information to the operator.
[0040] Position sensor 409 , control valve 406 and pressure sensor 411 are connected to the control unit 13 .
[0041] FIG. 2 shows the driveline 2 of the tractor 1 in more detail. The torque supplied by combustion engine 3 via a flywheel 4 is distributed to a mechanical branch 6 and a hydrostatic branch 7 of the transmission T via a planetary drive 5 . The hydrostatic branch 7 mainly consists of hydrostats 200 , 210 , wherein hereafter the hydrostat 200 is designated as the hydraulic pump 200 and the hydrostat 210 as the hydraulic motor 210 . Both hydraulic pump 200 and hydraulic motor 210 can be pivoted by an adjustment unit, also referred to as an ADU to change delivery/intake volume as described in FIG. 3 .
[0042] Both the mechanical branch 6 and the hydrostatic branch 7 of the transmission are driven and brought together on a CVT output shaft 10 at the end of CVT, T. The CVT output shaft 10 delivers an output torque to the respective driveline front and rear axles 11 and 12 .
[0043] CVT output shaft 10 drives a rear axle differential 12 a splitting the torque to a left rear axle portion 12 b and a right rear axle portion 12 c . Both rear axle portions 12 b , 12 c are provided with brakes 12 d , final reduction gears 12 e and wheels 12 f.
[0044] CVT output shaft 10 also drives a front axle drive gear pair 11 a followed by a front wheel drive clutch 11 b to disengage and engage front axle driveline. In addition a front brake 11 c is provided which is connected to a cardan shaft 11 d which ends in a front axle differential 11 e splitting the torque to a left front axle portion 11 f and a right front axle portion 11 g . Both front axle portions 11 f , 11 g are provided with final reduction gears 12 h and wheels 12 i . Wheels 12 i are steerable about a substantially vertical axis using a hydraulic steering cylinder 11 j mounted on the front axle.
[0045] The driveline 2 is also equipped with an anti-skid system 15 which mainly consists of an anti-skid control unit 15 a integrated in the tractor control unit 13 of the tractor 1 , speed sensors 15 b for each wheel 11 i , 12 f and a further anti-skid sensor 15 c . The anti-skid sensor 15 c provides parameters to control the brake function, for example acceleration in various axes, or inclinations of the vehicle. Anti-skid control unit 15 a may be separate from tractor control unit 13 .
[0046] Alternatively, a GPS system may also deliver parameters such as the acceleration or the inclination of the vehicle.
[0047] FIG. 3 shows a diagrammatic sketch of the hydrostatic mechanical split type transmission T having an adjustment unit ADU defined by the broken line. The components outside the broken line belong to the power unit of the transmission.
[0048] The hydrostats 200 , 210 illustrated in FIGS. 2 and 3 are an axial piston pump and an axial piston motor of an oblique-axis design, in which the delivery/intake volume is changed by the pivoting of the axis of rotation of the pistons to an axle drive shaft, not shown.
[0049] By means of a first valve unit 30 allocated to hydraulic pump 200 and by means of a second valve unit 31 allocated to the hydraulic motor 210 , the individual pivot angle of the hydraulic pump 200 and/or of the hydraulic motor 210 can be adjusted.
[0050] Depending on the specified revolution speed transmission ratio iT set by the operator via control unit 13 an actuator element 20 is rotated by means of an actuator motor 21 . The actuator motor 21 is in this case controlled by the control unit 13 . Because the valve units 30 , 31 are coupled to the actuator element 20 , these valve units 30 , 31 are displaced corresponding to the actuator element 20 . As a result, oil present in a line 32 can flow into a cylinder 33 , 33 ′, 34 , 34 ′ allocated to the valve unit 30 , 31 .
[0051] Due to the displacement of the actuator element 20 , the oil flow is accordingly directed out of line 32 and into the cylinders 33 , 33 ′, 34 , 34 ′. Thereby the pivot angle of the hydraulic pump 200 and of the hydraulic motor 210 is adjusted. The pivot angle, and therefore the delivery volume of the hydraulic pump 200 and the intake volume of the hydraulic motor 210 can be changed accordingly. This makes it possible for the revolution speed of the axle drive shaft (not shown in FIGS. 2 and 3 ) to be adjusted, and with it the revolution speed transmission ratio of the transmission T.
[0052] The hydraulic pump 200 is connected by fluid circuit HC to the hydraulic motor 210 . The fluid circuit HC in has an upper circuit UHC and a lower circuit LHC. The direction of the arrow F represents a flow direction of the fluid located inside the hydraulic circuit HC during forwards travel of the tractor and the direction of the arrow R represents a flow direction of the fluid during reverse travel of the tractor.
[0053] By means of a first measuring unit 110 , the pressure value pUHC prevailing in the upper circuit UHC can be measured. This pressure value pUHC is then sent to the control unit 13 represented in FIG. 1 . Moreover, both the pressure in the upper circuit UHC as well as the pressure in the lower circuit LHC is conducted by means of a shuttle valve 120 to a second measuring unit 100 in order to measure the pressure value pHCmax. This pressure value pHCmax is also sent to the control unit 13 .
[0054] The shuttle valve in the transmission T is designed in such a way so as to communicate to the second measuring unit 100 the greater of the two pressures present in the upper circuit UHC or the lower circuit LHC as a pressure value pHCmax. When the tractor is stationary, the second measuring unit 100 issues a system pressure of the upper circuit UHC or the lower circuit LHC as pressure value pHCmax. A rotation sensor, not visible in FIG. 2 , is arranged at the hydraulic motor 210 with which the direction of the rotation of the hydraulic motor 210 is determined and the direction of travel of the vehicle can be concluded.
[0055] When the vehicle is stationary a system pressure of about 15 bar is set in the fluid circuit HC. This system pressure of 15 bar results from the fact that, by means of a supply line 130 , the fluid circuit HC is supplied with a constant system pressure by means of a constant hydraulic pump, not shown, driven by the combustion engine. Two check valves 140 prevent oil from flowing back into the supply line. As soon as the utility vehicle moves or the transmission is no longer stationary, the pressure inside the fluid circuit rises, depending on the drive torque, to a high-pressure value of over 15 bar. With an average loading of the transmission, a high-pressure value of between 250-350 bar is provided. A limit of 500 bar must not be exceeded to avoid over stressing of the transmission and its components.
[0056] Pressure pHCmax, transmission ratio iT, or the pivot angle of the hydraulic motor 210 , or alternatively the intake volume V of the hydraulic motor 210 represent parameters which determine the output torque Mhydr of the hydraulic branch 7 . As the transmission ratio iT is known, the pivot angle and intake volume parameters of the hydraulic motor 210 are can be determined by look-up tables or characteristic maps.
[0057] As described in relation to FIG. 1 , the torque supplied by combustion engine 3 is distributed to a mechanical branch 6 and a hydrostatic branch 7 of the hydrostatic mechanical split type transmission T in which the fraction of torque transmitted by both branches depends on the transmission ratio iT. So if the fraction of the hydrostatic branch 7 is determined as described above, the fraction Mmech transmitted by the mechanical branch 6 can also be determined depending on the current transmission ratio iT.
[0058] The overall output torque MOT of the transmission can then be calculated from
[0000]
MOT
=
Mhydr
+
Mmech
=
pHC
max
*
V
2
π
+
Mmech
(
Equation
1
)
[0059] The pressure pHCmax is measured as described above and the intake volume V of the hydraulic motor 210 is determined by characteristic maps depending on the transmission ratio iT.
[0000] The output torque MOT of the transmission is supplied to the wheels resulting in a wheel torque MW:
[0000] MW=MOT*iTW (Equation 2)
[0060] In this equation iTW represents the overall gear ratio between the transmission and wheel and is the product of the gear ratio of the rear axle differential 12 a and the final reduction gears 12 e in rear wheel mode, for example:
[0000] ITW= 9.2(for the rear axle differential 12 a )×3.58(for the final reduction gears 12 e )=32.97 overall.
[0061] Knowing the wheel torque MW, the pull force FP can be calculated by using the known relationship of the forces on a wheel as shown in the diagram in FIG. 4 .
[0000] MW=FP*r+FV*f=FC*r (Equation 3)
[0000] In which:
r represents the effective wheel radius depending on tyre pressure and wheel size provided by the wheel manufacturer in respective tables f represents the offset of the point of application of the wheel vertical force (see FIG. 4 ) caused by roll resistance and sinking of the wheels
[0064] The circumferential force FC is a theoretical value achieved by converting equation (3):
[0000]
FC
=
M
W
r
=
FP
+
FV
*
f
r
(
Equation
4
)
[0065] As the linkage control only needs an indication of an increase in pull force FP, FV (which remains constant) can be ignored and so the equation can be simplified to:
[0000]
M
W
r
=
FP
(
Simplified
Eq
.
4
)
[0066] Thus an increase of the pull force ΔFP would result in an increase of the torque demand ΔMW and therefore an increase of pHCmax.
[0067] As pHCmax is constantly measured in the system, this parameter can be used to control the linkage based on an increased draft force applied by the implement.
[0068] So by monitoring pHCmax which is already done for transmission control and protection purposes, an increase or decrease of the draft or pull force can be detected and processed in the electronic linkage control system to provide functions like draft control and intermix position/draft control.
[0069] The change in drag force is fed into a tractor control unit which is programmed to higher, or lower the linkage in response to the change as programmed. In accordance with the invention, the vertical displacement of the linkage is limited.
[0070] This limit prevents the implement or tractor being damaged unnecessarily by a downwards or upwards movement of the linkage in response to a change in drag force.
[0071] There are four cases where the movement of the linkage in response to a change in drag force may cause problems when in drag mode. In each case, the implement is in an operating condition be it attached to a ball hitch and not the linkage, or stowed for transportation, or attached for operation without contacting the ground, or semi mounted or fully mounted. The term implement covers all tools, attachments and equipment which can be attached to a tractor including the following which is not an exhaustive list: ploughs, tow bars, sprayers, mowers, drills and planters.
[0072] In the case where an implement is attached to a ball hitch and not the linkage, or a trailer is connected by a tow bar to the tractor. A decrease in drag force may result in the linkage being highered which may cause the linkage to collide with the wheels of the tractor or the tow bar which is dangerous. Similarly, if an increase in drag force is detected, for example if a tractor is travelling uphill, the linkage may be lowered which may result in an attached tow bar colliding with the tractor wheels.
[0073] So, in a first step, an implement is detected (for example, via the electric supply/light connector). Alternatively fluid couplings may be used to detect the attachment of an implement. But this connector does not provide information as to where the implement is attached (that is whether it is attached to the linkage or to the ball hitch).
[0074] Moreover, the pressure in the lifting cylinders cannot always be used to detect whether an implement is not attached or semi mounted to the linkage.
[0075] For example, an unloaded linkage may result in the lifting cylinders indicating a pressure of 11 bar which represents a mass of the linkage as being around 600 kg. When a plough is mounted to the linkage and engages the ground (semi mounted) the pressure may change to about 15 bar as the ground supports some of the weight of the plough. On the headland, when fully lifting the plough from the ground for rotation, the pressure may increase to about 45 bar. The difference in pressure between the implement being semi mounted and an unloaded linkage is small: 4 bar+/−a tolerance of 1 to 2 bar which is difficult to detect. This may result in that the condition of a plough being semi mounted is not detectable by the system and as a result the drag mode will remain in an active mode because the pressure limit has not been reached. If this happens, then the linkage may be moved to its highest or lowest position in response to the drag force which can have serious ramifications if an implement, such as a plough is attached. If the pressure limit is set too high by the operator, the drag mode is deactivated while an implement is attached.
[0076] Therefore, in accordance with the invention the vertical displacement of the linkage is limited in the drag mode when an implement is attached to a ball hitch of the tractor and not the linkage, or when a tow bar is attached to the tractor to avoid the implement or tow bar being dropped to the ground, or raised high unexpectedly.
[0077] In the case where an implement is stowed for transportation in a fully lifted position. In this situation the implement is held high in a stowed position for transportation on the road. Using the cylinder pressure to detect the lifted position is not suitable. As described above, the pressure of the lifting cylinders of a lifted linkage can be too similar to the cylinder pressures when the implement is engaging the ground. It is therefore difficult to safely distinguish between these two different situations.
[0078] Therefore, in accordance with the invention the vertical displacement of the linkage is limited when an implement is being transported to avoid the case of an implement being dropped onto the road.
[0079] In the case where an implement is not contacting the ground during operation, for example an attached spreader. If the operator forgets to deactivate the drag mode, the sprayer may be lowered or highered unintentionally when a change in drag is sensed. Again, if vertical displacement of the linkage is limited in response to a change in drag force, the damage to an attached implement which does not contact the ground during normal operation is avoided or limited.
[0080] In the case where an implement is fully mounted, semi mounted, stowed for transportation or attached for operating above the ground, the risk of damage caused by an unintentional movement of the linkage is greater the faster the tractor is travelling. Accordingly, the range of the vertical displacement of the linkage is limited in relation to the speed of the tractor. The higher the speed of travel of the tractor, the narrower the vertical displacement range of the linkage. For example, if the tractor is travelling between 0-10 km/hr, the linkage may have a limited range of movement of 20 cm. If the speed is between 11-20 km/hr, the range of movement of the linkage may be limited to 10 cm, thus reducing the risk.
[0081] The linkage may also be equipped with means to detect if an implement is attached thereto, for example a sensor in the attachment hooks of the lower links 401 . The range of vertical displacement of the linkage can be limited accordingly as described in the above situations.
[0082] In accordance with the invention, the vertical displacement of the linkage is limited for the drag mode by pre-determined settings defined by the linkage or tractor manufacturer or by the operator.
[0083] As the difference of the pull force FP cannot be used as a control parameter for damping the implement linkage when the linkage is stowed high in a position for transportation, the pressure sensor 411 is provided to measure the fluid pressure in the chamber 403 a of the hydraulic actuating cylinders 403 . A variation of the measured pressure signal from sensor 411 indicates that the implement is oscillating which can also result in the weight on the front axle varying which can cause the tractor to oscillate which impacts on the steering and stability of the tractor. So the signal from pressure sensor 411 is forwarded to the control unit 13 to adjust the damping characteristics of the implement lifting circuit. The damping characteristics can then be adjusted by the linkage control system by adjusting the control valve 406 to reduce oscillation by allowing the implement to move relative to the tractor and thus increase driving steerability and stability.
[0084] As described previously, there are different modes of linkage operation: Position control mode, Draft Control mode and Position/Draft intermix mode in which the height of the linkage is continually supported by the tractor. But the linkage can also be set to a “float position” mode in which implements, such as seed drills, which have a ground contacting wheel or wheels can follow the ground contours with part of the weight of the implement supported by the implement wheel or wheels) and part of the weight supported by the linkage as the implement is drawn along behind the tractor.
[0085] Alternatively, the damping may be adjusted by means of wheel load sensors which indicate the variation in wheel load which is symptomatic of tractor oscillation. These wheel load sensors may be pressure sensors measuring pressure variations in the suspension cylinder of the front axle, or strain gauges in the rigid rear axle housing.
[0086] Although the foregoing examples have concentrated on linkage control systems, as indicated previously the invention is not so limited, being applicable to any tractor control system for the controlled operation of an implement where a draft force measurement is required.
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A control system for a tractor having a transmission with a hydraulic drive circuit in which a hydraulic pump supplies pressurised fluid to a hydraulic motor. The control system controls an operating condition of an implement attached to the tractor and said control system comprises a pressure sensing means which senses the pressure in the hydraulic drive circuit and provides a signal which is indicative of the current pull force necessary to pull the implement. The control system further comprises a control means which receives the pressure signal and a second signal relating to the speed of the tractor and adjusts the current position of the implement to a new position when said pressure signal varies. The new position lies within a pre-determined position range dependent on the second signal in order to maintain an optimal, yet safe operating condition of the implement.
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CONTRACTUAL ORIGIN OF THE INVENTION
The United States Government has rights in this invention pursuant to Contract No. EY-76-C-07-1570 between the U.S. Department of Energy and EG&G Idaho, Inc.
BACKGROUND OF THE INVENTION
This invention represents an improvement in bearings utilized in rotor assembly fluid metering devices. The intended application of the invention is in the metering of flow parameters in a high pressure water steam line in relatively inaccessible locations. In such an environment, conventional unlubricated bearings typically suffer from mechanical wear and bearing corrosion. Corrosion products are also generated from the pipes enclosing the flowing fluid, and the resulting particulate corrosion matter can cause seizure of conventional bearings. Attempts have been made to prevent bearing to shaft contact by use of hydrodynamic bearings, but this type of bearing requires a minimum critical rotational velocity before the rotational forces induce the formation of complete fluid film between the moving parts. E. E. Bisson and W. J. Anderson, Advanced Bearing Technology, NASA, 1964. As a consequence, bearing lifetime is still substantially reduced by low rotational velocity mechanical wear and corrosion effects. Hydrostatic bearing systems have also been developed, which provide for pressurized injection of fluid between bearing surfaces; however, such systems require complex plumbing and multiple bearing fluid supply sources, which often result in pressure differences among the different bearing cavities of the device. C. Cusano and T. F. Conry, Trans. of ASME, J. Eng. for Ind. (Feb. 1974).
It is therefore, an object of the invention to provide a hydrostatic bearing fluid system with a common fluid pressure supply system, thereby establishing a uniform bearing fluid pressure throughout the system.
It is a further object of the invention to provide a means for rapid replacement of fluid between all bearing surfaces, in a hydrostatic bearing fluid system, thereby minimizing crevice corrosion.
Additional objects, advantages, and novel features of the invention will be set forth in part in the description which follows, and in part, will become apparent to those skilled in the art upon examination of the following or may be learned by practice of the invention. The objects and advantages of the invention may be realized and attained by means of the instrumentalities and combinations, particularly pointed out in the appended claims.
SUMMARY OF THE INVENTION
The present invention relates to the use of hydrostatic fluid bearings for the support of rotating parts in devices such as turbines and compressors. The invention described herein includes a rotor assembly in a fluid metering device with bearing fluid supplied to all bearing interfaces by a distribution means which yields an equilibirum pressure throughout the system and also results in rapid replacement of bearing fluid between bearing surfaces.
BRIEF DESCRIPTION OF DRAWINGS
FIG. 1 is a cross section of the bearing fluid distribution system as a whole;
FIG. 2 shows a cross section through line 2--2 of FIG. 1;
and
FIG. 3 shows a cross section through line 3--3 of FIG. 1.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
The preferred embodiment is shown in FIGS. 1--3. In FIG. 1, fluid meter assembly 10 is bolted to assembly mount 12, which may be attached with mounting bolts 14 to the interior of pipelines containing fluid to be metered. In the embodiment shown, the fluid flow to be metered is from right to left as shown by arrow 11. During fluid flow, rotor assembly 16 is separated from all adjacent component surfaces by a film of hydrostatic bearing fluid 17 injected under pressure. Common fluid pressure supply 18 delivers bearing fluid at a constant pressure to all bearing surfaces through tubing 20 to fluid meter assembly 10. Bearing fluid 17 passes through tubing 20, which enters downstream bearing assembly 22. Within downstream bearing assembly 22, tubing 20 passes through cylindrical housing 24 and concentric housing 26 and terminates at interior inlet 28 of housing 26.
Rotor shaft 30 is attached by weldments 32 to interior housing 26 such that shaft 30 is concentrically mated to tubing 20 at interior inlet 28. Enclosure of bearing assembly 22 is completed by attachment of downstream thrust bearing section 34 to interior housing 26 by weldments 35. Downstream thrust bearing section 34 encircles rotor shaft 30 and fits in a recess in housing 26 such that the exterior face of section 34 is flush with the bearing surface of assembly 22 facing the bearing surface of rotor hub 36.
Bearing fluid 17 enters downstream bearing reservoir 37 of assembly 22 through a plurality of downstream shaft orifices 38 in rotor shaft 30 and exits reservoir 37 through a plurality of downstream thrust orifices 40 in downstream thrust bearing section 34, shown in FIG. 2. Referring to FIG. 2, thrust orifices 40 pass through section 34 and terminate in downstream thrust bearing pockets 42 which act to spread the flow of bearing fluid 17 before impacting upon the adjacent face of rotor hub 36. The intent is to spread the fluid flow pattern over the entire bearing surface in order to avoid metal-to-metal contact during bearing operation and to replace all fluid within the interface of the bearings, thereby minimizing crevice corrosion effects. Bearing fluid 17 also is injected through a plurality of rotor shaft orifices 44 between the exterior surfaces of rotor 30 and the inside radial surface of rotor assembly 16. Rotor shaft orifices 44 exit rotor shaft 30 and terminate in shaft pockets 46 which act to spread the flow of bearing fluid 17 along the entire bearing interface between rotor shaft 30 and the inside radial surface of rotor hub 36. Again, the purpose is to avoid metal-to-metal contact and minimize crevice corrosion effects by rapid replacement of fluid at bearing interfaces.
Rotor shaft 30 terminates within upstream bearing reservoir 47 of upstream bearing assembly 48, rotor shaft 30 having an exterior threaded surface 50 engaged to upstream thrust bearing section 52. Enclosure of assembly 48 is completed by attachment of bearing flow cap 54 over upstream thrust bearing section 52. Bearing fluid 17 enters reservoir 47 of assembly 48 through the open end of rotor shaft 30 and exits assembly 48 through a plurality of upstream thrust orifices 56 in upstream thrust bearing section 52, shown in face view in FIG. 3. Upstream thrust orifices 56 pass through section 52 and terminate in upstream thrust bearing pockets 58 which spread the flow of bearing fluid 17 to avoid metal-to-contact during bearing operation and also to minimize crevice corrosion effects by rapid replacement of fluid at bearing interfaces. As shown in FIG. 3, one possible geometry for bearing pockets 58 is of concentric inner and outer arc sides of a circle and closed semi-circular ends.
During operation of fluid meter assembly 10, common fluid pressure supply 18 provides bearing fluid 17 at one common pressure to all bearing surfaces. An intervening fluid film is interposed between bearing surfaces at all times regardless of the presence or lack of hydrodynamic forces operating on rotor assembly 16. The uniformity of bearing fluid pressure from common fluid pressure supply 18 gives rise to extremely stable mechanical operation, thereby minimizing mechanical wear of bearing surfaces. The design of the bearing distribution system insures complete coverage of bearing interfaces with a uniform film of bearing fluid 17 at a constant pressure. In addition to improvement of mechanical stability of bearing operation, the bearing fluid distribution system results in rapid replacement of fluid between bearing surfaces. Rapid fluid replacement minimizes crevice corrosion effects by eliminating build-up of contaminants and eliminating stagnant fluid collection, all of which can prevent crevice corrosion being the limiting factor in fluid bearing operation.
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A rotor assembly fluid metering device has been improved by development of a hydrostatic bearing fluid system which provides bearing fluid at a common pressure to rotor assembly bearing surfaces. The bearing fluid distribution system produces a uniform film of fluid between bearing surfaces and allows rapid replacement of bearing fluid between bearing surfaces, thereby minimizing bearing wear and corrosion.
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CROSS REFERENCE RELATED TO APPLICATION
This application relates to co-pending U.S. application Ser. No. 07/717,685 entitled IMPROVED DISPOSABLE LAP BLANK filed in the name of Ken Wood on Jun. 19, 1991, and which application being commonly assigned with the assignee of the present invention.
BACKGROUND OF THE INVENTION
This invention relates to a blocking apparatus for an ophthomalic lens blank of the type having a finished exteriorly disposed outer surface and an interiorly disposed inner surface capable of being machined to satisfy a given prescription, and deals more particularly with an apparatus for automatically blocking by bonding the exteriorly disposed outer surface of the lens blank to a block in precise orientation relative to reference structure on the block so that the block can be mounted directly to an automated surfacing generator where the inner surface is machined in correct orientation to the outer surface to achieve the desired prescription.
In the creation of a lens surface using automated surfacing generating systems, such as disclosed in U.S. Pat. No. 4,989,316 issued to Logan et al., data describing prescription information is transmitted to the computer of the surface generating system, and is thereafter used by the machine to cut the interiorly disposed surface of the lens to create the desired lens. The machine disclosed in this patent, as well as with other such machines that are presently in the marketplace, require that the finished outer surface of the lens blank be bonded to a block for holding the lens so that it can be placed in the surfacing machine during a cutting operation and in a lapping machine during the fining and polishing process.
Previous methods for lens blocking require manual alignment of the lens with a universal grid in accordance with axis and centering data for a prescription and marking the lens with ink to create reference marks for the actual blocking operation. At the blocking device, these marks are visually aligned with the block and a low melting point metal alloy is injected between lens and block to bond the two together. Thus, it can be seen that there are two manual alignments, the first involving visual information of a universal grid and the markings that are made on the lens relative to this grid and the second being the actual alignment of these markings with corresponding reference points on the blocking station. Among the drawbacks associated with such prior art methods is the necessity for each alignment to be made by a skilled operator. In addition, the metal alloy used to bond the lens blank to the block includes such elements as bismuth, tin, cadmium and lead, which materials are toxic and environmentally hazardous. Also, the characteristics of the molten alloy are such that the surface of the lens blank to which the alloy is bonded to, must be treated, for example, by precoating the outer surface of the lens as a means of improving adhesion of these bonding agents.
In addition, it is essential that the lens blank outer surface and the block are bonded in precise alignment with one another in accordance with prescription data because the surface generator machines the inner surface with reference to the block, and the correct prescription can be achieved only if the inner surface of the lens is aligned correctly with the outer confronting surface of the block. This relative positioning of the block and the lens opposing surfaces affects the accuracy of obtaining a desired lens thickness, since this outcome is dependent on the spacing of the block and the outer surface of the lens. Also, prismatic power depends on centering and skewing of the block on the outer surface of the lens. Cylinder power axis, required for astigmatism correction, depends on angular orientation of the block relative to any multifocal elements on the outer surface of the lens. Thus, a number of factors influence the relative positioning of the lens blank relative to the block.
Previous lens mounting blocks limited the type of lens surfaces which could be cut in the involved lens blank. That is, in these previously known blocks, the lens blank was supported by portions of the block which projected from it so that only a partial gap was provided to space the lens blank from the block. Because these projecting block portions supported the lens blank about its periphery, they did not allow the lens to be machined to a zero thickness in areas of the lens which overlie them, such as in the case of a "feathered" lens shape. Even if these projections did not interfere with such surfacing processes, the alloy bonding material which holds the lens blank to the block, would not lend itself to being readily cut by the cutting tool given its hardness and the inherent toxicity attributable to having metallic shavings released into a work environment.
It is therefore an object of the invention to provide an apparatus of the aforementioned type in which alignment of the lens blank relative to a given orientation on a blocking part is accomplished by material viewing without sighting devices thereby eliminating the heretofore known problem of viewing parallax.
Still a further object of the invention is to provide an automated blocking system whereby a user is may conduct an alignment procedure on one blank while simultaneously conducting a blocking operation on another.
A further object in the invention is to provide a system whereby prescription data describing the orientation of a lens surface to be machined relative to the block it is to be bonded to is stored in a host computer and is on-demand downloaded from the host to an apparatus of the type heretofore discussed.
It is still a further object of the invention to provide a machinable bonding agent for bonding in a lens blank and block assembly so as to support the lens blank such that up to zero thickness cuts can be made in the blank about its periphery without cutting the block.
Yet still a further object of the invention is to provide an apparatus capable of the bonding a lens blank with the block using various bonding agents, including low melting point thermoplastic, through management of temperature and pressure during the injection and curing cycle and to provide such a bonding agent which eliminates the need for pre-coating the outer surface of the lens as a means of improving adhesion of the bonding agent.
Another object of the invention is to provide a blocking system which provides a uniform support for the lens blank to assure aberration free surface generation and polishing.
Still a further object of the invention is to provide a block position sensing support which during a bonding operation detects incorrect positioning of the block in the apparatus thereby stopping the process to avoid blocking in unwanted prismatic power and incorrect lens thickness.
A further object of the invention is to provide a block positioning support whereby the block is automatically moved to a designated angular orientation to align the prescription cylinder axis.
SUMMARY OF THE INVENTION
The invention resides in an apparatus and related method for automated blocking of an ophthalmic lens blank to a block for working the lens. The apparatus comprises a base and a means supported on the base for displaying a target image for a given orientation of a lens blank relative to the base. An alignment station is provided and is supported by the base for supporting and aligning a lens blank relative to the target image. Along with the alignment station, a blocking station is also provided and is supported by the base for receiving and supporting a block in a given orientation relative to the base. A transport means is located intermediate and adjacent the alignment and blocking stations for moving the lens blank from the alignment station to the blocking station while maintaining lens blank orientation established at the alignment station. The blocking station includes a blocking support for the lens block, a lens blank support, and a means for injecting heated liquid bonding material between lens and block which solidifies on cooling to join the lens blank and the block to one another.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1a is a front elevation view of the automated blocking apparatus as covered by its housing.
FIG. 1b is a top plan view of the apparatus of FIG. 1.
FIG. 2 is a front elevation view of the automated blocking apparatus with the housing removed.
FIG. 3 is a top plan view of the automated blocking apparatus with the housing removed.
FIG. 4 is a schematic of the central control system.
FIG. 5 is a vertical section view taken along line 5--5 in FIG. 2 showing the viewing tower.
FIG. 6a is a partially fragmentary side elevation view showing the positioning device apart from the apparatus as a whole.
FIG. 6b is a detailed top plan view of the positioning device shown apart from the apparatus.
FIG. 6c is a front elevation view of the device shown in FIG. 6b.
FIG. 7 is a top plan view of the alignment support ring as attached to the mounting block.
FIG. 8 is a side elevation view of the alignment support ring shown in FIG. 7.
FIG. 9 is a partially fragmentary vertical section view showing the blocking station of the apparatus.
FIG. 10 is a vertical sectional view taken along line 9--9 in FIG. 2.
FIG. 11 illustrates the superposition of the support ring and provided target as superimposed on one another and as displayed in the viewing tower.
FIGS. 12a and 12b show a first embodiment of a block seating device.
FIGS. 12c and 12d show the block seating board connections in a second embodiment of a blocking station.
FIG. 13a is a schematic diagram of the block seating sensor circuit.
FIG. 13b is a schematic diagram showing in more detail the circuitry of FIG. 13a.
FIGS. 14a and 14b illustrate a flowchart of the general operation of the apparatus.
FIG. 15 is a detailed flowchart illustrating the operations of the computer generated graphic template feature of the invention.
FIG. 16 illustrates a projected target for a round multi-focal lens with off centered axis.
FIG. 17 illustrates a projected target for a flat top multi-focal lens.
FIG. 18 illustrates a projected target for a progressive lens.
FIG. 19 illustrates a projected target for a single vision lens.
FIG. 20 illustrates decentration and other optical offsets respectively on a lens.
FIG. 21 shows a deblocking device.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
FIG. 1 illustrates an automated lens blocking apparatus generally illustrated as 2 embodying the present invention. The apparatus is of the type which can be placed on a support, such as, the flat surface of a table, and operated by a user if desired while sitting. A housing 3 encloses the apparatus giving the apparatus a streamlined, low profile look. A user interface is provided in the form of a keypad 13 which is linked to appropriate controls in the apparatus to cause automatic blocking of a lens blank to an associated block in a manner which is provided in accordance with the invention.
As best illustrated in FIGS. 1-3, the apparatus 2 is comprised of a base 1 with a display screen 5 and an alignment support ring 8 having an upwardly directed annular edge for supporting a lens blank 14, each supported on the base, and above which screen is disposed an optical tower 4 which presents the user with a projected alignment template 6 created by the display screen and on which is superimposed a projection of an alignment support ring 8. A pick and place means 10 is also provided and includes a releasable gripping means 12 controllably positionable between a first location X1 located coincidentally with the alignment support ring 8 and a second location X2 located coincidentally with a blocking station 16, with the pick and place means 10 further being provided with means capable of lifting the lens blank 14 off the alignment support ring 8 and transporting it to the blocking station 16 disposed generally adjacent the ring 8. The blocking station includes a support 20 for supporting a lens block 22 to be bonded to an associated lens blank and a reservoir means 18 having a supply of bonding material in liquid form provided to releasably secure the lens blank to the block at the blocking station. The reservoir means includes a tub-like member 17 defined by a base 19 and four side walls 21,21 opening upwardly so adapted to contain a bath of the liquified blocking material. Operations of the apparatus are controlled by a central controller 24 linked to the display screen 5, the pick and place transport means 10 and the appropriate subcontrol systems associated with the blocking station 16.
The central controller 24 as illustrated in FIG. 4 is provided as part of the apparatus 2 and is housed within the housing 28 and is connected to the keypad 13 for data input purposes and operation controls. The system includes a central processing unit 48 which, in the illustrated example, is comprised of a 286 CPU board with a 1.44 Megabyte ROM disk on which is encoded the EXECUTABLE program for the automatic lens blocking operation. The CPU board further includes 640 Kilobytes of RAM which is linked to the ROM disk through appropriate bus work such that the ROM program is downloaded to RAM as a part of a start up procedure. Also linked to the CPU board 48 are serial ports 50 and 52 connectable to external data providing sources. Among these sources is an external reader, such as a bar code scanner, which scans job number which may for example be printed on the holding box of the lens to be worked. The other is connectable to a host computer in which a data base of particular job files including the needed descriptive information for each job is stored.
The central controller 24 further includes an input/output sub-controller 54 linked to a peripheral driver 56 for driving peripheral devices 58, such as bonding material, heaters 60,60 associated with the reservoir means 17, an axis motor 62 associated with the blocking station 16, a traveler arm positioning drive motor 64 associated with the pick and place means 10 and a bank 66,66 of solenoid actuated valves each individually separately activatable to introduce pressurized air to respective air activated devices, such as actuators as well as being responsible for controlling the flow of bonding material at the blocking station 16. The central control 24 also includes a LCD sub-controller 68 linked to the display screen 5 for causing the projected alignment template to be displayed on the screen in accordance with data prescribing the characteristics of the displayed image. The keypad 13 which is primarily provided for the user to prompt certain commands by depressing keys to cause, for example, transport of the blank to the blocking station, also allows the user to edit or manually enter data otherwise downloaded for example, from a host computer or entered by scanning.
Referring now to FIG. 5, and in particular to the details of optical tower 4, it should be seen that the optical tower is provided with a display screen 5, a tower frame 26 extending upwardly from and disposed internally within the base 1 and which upper frame portion being covered by a housing 28 partially enclosing the tower and defining a viewing port 30 opening to the front of the apparatus. The viewing port presents the image 6 shown in FIG. 1a to the user which is the combined affects of the superposition of the alignment support ring 8 and the graphic generated by the display screen 5 as together projected through a mirror and lens projection system housed within the optical tower 4. The projection system further includes a radiant energy source 34 in the preferred form of a halogen lamp disposed within the housing at the top of the optical tower, a first light redirecting mirror 36 disposed adjacent to the lamp 34 and oriented at an angle relative thereto such that light radiated from the lamp is redirected downwardly through a fresnel collimating lens 44 toward the display screen 5 supported on the apparatus base 1 below it. Disposed below the display screen 5 and the alignment support ring 8 is a diffusing surface 37 on which the projected image of the lens and display screen graphics are formed, and which surface is defined by a frosted MYLAR Film. A mirror 38 is oriented at an angle with respect to the downwardly directed light. A third light redirecting mirror 40 is provided at the back of the tower and is disposed generally adjacent the second mirror 38 for the purpose of reflecting the image cast onto it by the second mirror toward a viewing mirror 42. The viewing mirror is disposed generally at the back of the tower and is located adjacent the third light redirecting mirror 40 such that the image cast onto it is caused to reflect on the viewing mirror and be seen by the user through the viewing port 30. The superimposed image formed on the diffusing surface 37 is caused to pass through a second collimating freznel lens 46 disposed between the second and third light redirecting mirrors 38 and 40 prior to being projected on the viewing mirror 42. The lens 46 is an enlarging lens and is provided to enable easier viewing of the formed image.
The display screen 5 is a translucent liquid crystal display of the type commonly found in back-lit laptop computers and accordingly allows the collimated light RE directed downwardly from the first light redirecting mirror to pass through it and allow the displayed image to be projected along with the outline of the lens blank and various features onto the diffusing screen 37. The liquid crystal display is covered by a protecting glass plate 7 supported on the base 1 and may take many forms, but in the preferred embodiment it is 540×480 pixel VGA screen which is commercially available.
Referring now to FIGS. 6a-6c, and in particular to the details of the pick and place means 10, it should be seen that this means includes two spaced vertically extending support posts 72,72 disposed on the base 1, a way 74 having a central axis A and secured against movement within the posts at its opposite ends, and a traveler arm 76 disposed for movement along the way and driven in the indicated L direction by a drive means 78 and pivotal about the axis A of the way 74 through the intermediary of a pivot actuator means 80. The traveler arm 76 is cantilevered outwardly of the way 74 and carries at its distal end 120 a vacuum operated holding means 82 adapted to engage the inner surface 84 of the lens blank 14. The traveler arm 76 includes a journalling part 88 disposed about the way 74 for both pivotal movement about the axis A and linear movement in the indicated L direction. To these ends, the journalling part 88 is connected at its underside to a belt 90 which is trained at one end about a drive pulley 92 associated with the stepper motor 64 and is trained at its opposite end about a return pulley 96 rotatably mounted to an associated one of the posts 72,72. An opening 97 is formed in the one of the support posts 72,72 located adjacent the drive motor 64 permitting the endless belt 90 to pass between the drive and return pulleys.
Pivotal movement of the traveler arm 76 is effected by the pivot actuator means 80 which includes a double acting actuator 104 and a drive bar 98 extending substantially parallel to the axis A of the way 74. The drive bar is held in spaced parallel relationship with the way by means of end blocks 100,100 each journalled about the way 74 and each secured to the drive bar 98 at its opposite distal ends. One of the end blocks 100,100 includes a lever 102 integrally connected with it and projecting radially outwardly of the axis A in a generally upwardly extending direction. The lever 102 is connected to the double acting actuator 104 such that the sliding actuator rod 106 is pivotally connected at its free end to the lever 102 of the juxtaposed one of the end blocks 100,100 at 108, while the opposite end of the actuator 104 is connected to the base at a second pivot location 110. Pressurized air lines are connected to the actuator through inlets 112 and 114 the introduction and ceasation of pressurized air through each of these inlets being respectively controlled by solenoid valves disposed in the rack 66. A generally U-shaped cutout 116 is formed in the back side face of the journalling part 88 and is sized to snugly receive the outer diameter of the drive bar 98. The traveler arm 76 through this connection is thus caused to pivot between a lowered position resulting from the actuator being energized and the rod 106 prompted to its extended position, and a raised position corresponding to the retraction of the rod 26 by the respective introduction of pressurized air into the inlets 114 and 112 at different times.
The traveler arm 76, as illustrated is cantilevered outwardly of the way 74 such that the holding means 82 carried by it is positioned for engagement with the opposed face 84 of the lens blank when the lens blank 14 is positioned in the alignment support ring 8. The holding means 82 includes for this purpose a ball and socket gripper 122 disposed at the distal end 120 of the traveler arm 76. The socket part 124 of the gripper is threadly attached to the arm 76 and includes a cavity 126 communicating with an inlet 128 disposed between the cavity and the outer surface of the socket. A vacuum source is provided (not shown) remotely of the arm 76 and communicates with the cavity 126 through a vacuum line 73 connected between the inlet 128 and the vacuum source, with one of the solenoid valves in the bank 66 operating at a point along this line to selectively controllably open and close the applied vacuum to the gripper 122. Disposed annularly about the downwardly facing opening defined by the cavity 126 is a rubber seal 130 which seats on the confronting spherical surface of the ball part 132. The spherical surface of the ball part is mechanically maintained in confrontation with the rubber seal 130 by an elastic elongate element 134 acting between the two mated parts. A passage 136 is formed in the ball part 132 and communicates between the outer spherical surface of this part and a flared opening 138 disposed at the lower end of the ball part. The elastic element 134 is secured at its top end to the socket part and is stretched through the passage 136 and secured against movement at its opposite lower end within the flared opening 138 of the ball part. It being noted that the securement of the lower end of the elastic element 134 within the flared opening 138 does not significantly restrict the introduction of vacuum through the opening.
Disposed about the base of the ball part 132 is a lip seal 140 which acts between the ball part 132 and the inner surface 84 of the lens blank 14 to form an air seal when the arm is lowered bringing the gripper and the lens blank into engagement and with vacuum being continuously applied. It is a feature of the invention to allow the gripper 122 to engage the surface 84 of the lens blank 14 with a prescribed amount of positional adaptability provided by the elongate flexible element 134 such that the ball part 132 may reorient itself relative to the socket part during seating of the bellows seal 140 to the surface 84 of the lens blank. Once such seating on the lens surface is effected, the vacuum communicating within the gripper 138 not only serves to hold the lens blank to the gripper but further serves to lock the orientation of the ball part relative to the socket part through the intermediary of the annular seal 130 acting on the top spherical surface of the ball part 132.
Referring now to FIGS. 7, 8, and 9, it should be seen that the blocking station 16 includes a blocking ring 142 secured relative to the base on a blocking stand 144 disposed within and supported by the base 19 of the reservoir means 17 for the purpose of receiving and supporting a block 176 situated below a lens blank to be bonded with the supported block. The alignment support ring 8 is fixedly connected to the blocking ring by a coupling bar 148 integrally connected with the ring support at one end and is secured against movement at its other opposite end to the blocking ring 142 by suitable attachment means, such as screws 150,150, or the like. The alignment support ring 8 is disposed above the display screen 5 and is maintained in registration with a location known on the screen by the securement of the coupling arm 148 to the blocking ring 142. The alignment ring is also maintained in a vertically stable position through the intermediary of two sets screws 152,152 which rest on the glass cover plate 7 fixed to the base above the display screen 5. The coupling arm 148 has a bend 156 located in it intermediate its length for the purpose of vertically situating the upwardly directed edge 158 of the alignment ring 146 in a plane P coincident with the correspondingly upwardly directed edge 146 provided in the blocking ring 142 and is aided in such registry by the support of the sets screws 152,152 acting on the glass plate 7. The alignment ring 8 is thus positioned over the display screen 5 such that a visually discernable target 350 is projected about ring 8 for lens blank alignment purposes as will hereinafter become apparent as is best illustrated in FIG. 11.
The blocking stand 144 is specifically adapted to simultaneously hold a lens blank and a block in spaced vertical relationship in order that a bonding material B be interposed therebetween. To these ends, the blocking stand 144 is defined by a frame 159 having a generally hollow interior portion or chamber 160 disposed at its bottom end separated from the remainder of the blocking stand by a containment wall 162 and sidewalls 164,164 disposed generally orthogonally to the containment wall. Interposed between the blocking ring 142 and the chamber 160 is a fluid passage 166 communicating between the chamber and the blocking ring for the purpose of delivering and introducing the liquified bonding material B into the interior confines of the blocking ring 142 through an inlet 168. The interior of the blocking ring is provided with a frustoconical surface portion 170 which creates a mold cavity for the liquid bonding material. This interior ends in a support shoulder 172 defining a shouldered opening 174 correspondingly sized and shaped to receive a correspondingly shouldered structure 167 formed on the rear face of the lens block 176 as best illustrated in FIGS. 12a and 12b. A rotatable part 178 is journalled to the frame 159 for rotation about the indicated rotational axis C oriented concentrically with the shouldered opening 174 and is controllably rotatably driven by a positioning step motor 180 having a drive sprocket 186 drivingly connected to the rotatable part 178 through the intermediary of a toothed belt 182 engaging drive teeth 184 disposed about the periphery of the rotatable part 178 and about the periphery of the drive sprocket 186.
Mounted within the frame 159 of the blocking stand 144 is an actuator 188 having a sliding rod 190 vertically moveable between an extended position corresponding to the position taken by the rod when a user initially places the block 176 onto the blocking ring 142 and a retracted position corresponding to the lens block being lowered into the shouldered opening 174 and seated against the shoulder 172. Provided on the rotatable part 178 is an indicator 192 which co-acts with a sensor 194 secured to the frame 159 and connected to the peripheral driver 56 of the control system to establish an angular origin from which the part 178 is controllably rotated by the motor 180. The rotatable part 178 also includes at least one vertically disposed locating pin 196 which has an appropriately sized end shaped to fit within a corresponding sized and shaped blind locating opening 177 formed in the back face 163 of the lens block 176 so as to cause the block to be rotated a given angular amount from its designated origin according to any off axis parameter prescribed by the lens prescription. A barrier plate 161 is mounted to the frame to protect the component parts of the motor drive from damage by bonding material, but this plate nevertheless includes a circular opening allowing the locating pin(s) to freely rotate about the axis C.
The bonding material B in the preferred embodiment is a low melting temperature thermoplastic which exists normally in solid form and is maintained in a liquified state within the reservoir means 17 by a plurality of electric heater elements 200,200 which line the base 19 of the reservoir and are controllably energized by the peripheral driver 56 to maintain the blocking material at a temperature of 115-160 degrees Fahrenheit depending on the bonding material selected. For this purpose, a sensor is located within the reservoir to monitor the temperature of the bonding material bath and is linked to the control system to insure the designated temperature of the bath is maintained. The process of bonding the lens blank to the block involves situating the lens blank in a vertically spaced relationship relative to the block while the two parts are mounted on the stand 144 to create a gap G therebetween and injecting the liquified bonding material B into this gap to effect bonding. This is accomplished by causing the liquified blocking material B to move upwardly through the fluid passage 166 from the chamber 160 and fill the gap G. To effect such movement of the blocking material B, a positive air pressure source (not shown) is provided and is introduced into the chamber 160 through an opening 202 disposed between the chamber and a pressurized air line 204. The introduction of pressurized air into the chamber 160 is controlled by one of the solenoid actuator valves in the bank 66 acting independently and in response to a given key being depressed by the user. As such, depending on the volume of pressurized air introduced into the chamber 160, a corresponding displaced volume of the liquified blocking material is caused to be moved upwardly through the passage 166. This volume may be varied by varying the air pressure in the chamber, for example, by pulse width modulating the signal responsible for opening and closing of the air pressure solenoid valve in order to effect these ends. This is important in that depending on the viscosity of the liquified bonding material B, the solenoid valve responsible for introducing pressurized air into the chamber 160, can effectively be fluttered to create a tamping effect in the gap G as the material is caused to harden. Formed along a portion of the edge of the blocking ring 142 is a shallow cutout 141 which permits the bonding material to bleed out of the blocking ring as during the injection process.
The blocking ring 142 as best depicted in FIG. 7, is a hollow internally toroidal member having an internal confine 147 communicating with an inlet 143 and an outlet 145 the inlets and outlets are connected to a refrigeration station (not shown) which provides a supply of chilled water to the interior confines 141 for the purpose of fast hardening otherwise liquified blocking material B.
Referring now to FIG. 10, it should be seen that the liquified bonding material B in the bath contained in the reservoir means 17 flows freely between the reservoir and the chamber 160 of the blocking stand through an inlet 206 formed in one of the sidewalls 164,164 of the chamber 160. During periods when the lens blank is not being bonded to a block, the inlet 206 is normally open, but is closed-to-flow when blocking occurs. Closure and sealing of the inlet results in the chamber being effectively isolated so that it may be pressurized. This is done through the intermediary of a gate 208 which is pivotally mounted to an involved sidewall 164 such that it is operatively moveable between an opened position as indicated in the solid line wherein the inlet 206 is unrestricted against fluid passage and a closed position as indicated in phantom line corresponding to the condition where the inlet is closed to flow. To effect such pivotal movement of the gate 208, an actuator 210 is provided and is secured at one end to the base 1 of the apparatus and includes a sliding rod 211 moveable between extended and retracted positions corresponding respectively to the closed to flow and open to flow conditions of the inlet 206. The actuator 210 is connected to a pressurized air source, the on and off conditions of pressurized lines to the actuator, being controlled by one of the solenoid valves in the bank 66.
It is highly important to the blocking process to insure that the lens block is flushly seated in the blind opening before the blocking material B is injected. To these ends, a means is provided as part of the blocking stand 144 to ensure proper seating of the block during the bonding process. As illustrated in FIGS. 12a and 12b, the preferred means for this purpose includes providing a placement disc 171 disposed coaxially above the rotating part 178 and rotatably connected to the rotatable part 178 through the intermediary of the locating pin 196. The disc has an upper face 181 and a opposite lower face 183 and is secured against movement to the distal end of the vertically moveable rod 190 so as to be controllably moveably positionable between a raised position as illustrated in FIG. 12a corresponding the position assumed by the disc when a block is to be mounted on it and a lowered position as illustrated in FIG. 12b corresponding to the position assumed by the block during bonding of the block to a given lens blank. The placement disc 171 includes a diametric cut 179 opening to the bottom face 181 and a central slot 185 communicating with the cutout 179 and located in line with the central rotational axis C of the rotating part 178. Received within the internal cutout 179 are a pair of gripping arms 187,189 which are pivotally connected to the placement disc 171 in a scissors-like fashion through the intermediary of a pivot pin 191. Each of the gripper arms has a generally L-shaped configuration defined by a lower lever portion 193 extending orthogonally to the central axis C and gripping portion 197 extending generally coincidentally with the central axis C. Each of the gripping portions 197,197 is complimentary shaped when caused to be moved in a side-by-side orientation so as to create a generally arrow-like projection 201 which is symmetric about the axis C. Further, each of the gripping portions 197,197 includes an underflange 205 which extends generally orthogonally to the central axis C for the purpose of engaging behind a mounting flange 209,209 formed in the back face of the block.
Disposed within the placement disc 171 area first biasing means 207,207 which act between the top surfaces of the lever portions 193,193 of the arms and the internal surface of the cutout 179 to maintain the arrow-like configuration of the gripper portions 197,197. Disposed below the placement disc 171 is a second biasing means 209 which in the preferred embodiment takes the form of a helical spring disposed concentrically about the sliding rod 190 and the central axis C. The second biasing means 209 acts against an annular ring 211 positioned between it and the lower end faces of the level arm portions 193,193 to otherwise bias the gripper portions 197,197 apart from one another in the indicated condition as shown in FIG. 12b and to cause locking to occur between the upper surface 181 of the disc and the block.
The relative forces of the first and second biassing means are selected such that with the upward movement of the sliding rod 190, the force generated by the first biasing means 207 will exceed that imposed by the second biasing means 209 such that the arms 189 and 190 will be moved under the bias of the first biasing means so as to move the gripper portions 197,197 to a closed position to assume the arrow-like shape. Alternatively, as the sliding rod 190 is moved to a lowered or retracted position as illustrated in FIG. 12b, the force generated by the second biasing means is such that it exceeds that applied by the first biasing means so as to cause the gripper arm portions 197,197 of the arms 189,187 to be moved apart. The travel of the rod 190 has some lost motion such that the block is not only positively gripped by the disc, but is also caused to be positively held down under the force of the actuator 188. Seating is enhanced by the use of three equidistantly spaced support pins 232,232 mounted to the frame 159. Also, to better assist the user in the correctly mounting the block to the placement disc, a second locating pin 213 is provided and is given an elongate cross-sectional shape relative to that of pin 196 and fits within a correspondingly shaped hole 215 formed in the back face 163 of the block 176. This arrangement insures single orientation fitting of the block on the disc.
Referring to FIGS. 12c,12d and 13a,13b, a second embodiment of a means for insuring proper seating of the block on the support shoulder 172 is illustrated. To these ends, the shoulder 172 as best illustrated in FIG. 12c is defined by a substantially annular seating means 212 located within the blocking ring 142. The seating means includes a generally toroidal printed circuit board 214 plated on opposite sides thereof with three arcuate segment sets 216a,b, 218a,b, 220a,b each respectively occupying a 120 degree portion of the circuit board 214. For purposes of this discussion, the arcuate segments occupying the top face of the circuit board will be designated under the "a[ label while those occupying the underlying face of the circuit board will be designated under the "b" label. These arcuate segments are connected to appropriate control circuitry for the purpose of detecting a seating condition whereby the lens block 176 is not flushly seated on the shoulder 172. This is important because any deviation from an otherwise flushly seated lens block prior to the blocking operation commencing, will result in unwanted prism and incorrect thickness being machined into the lens surface once the lens blank and block assembly is placed into an automated cutting machine, such as the one disclosed in the aforesaid U.S. Pat. No. 4,989,316.
As illustrated in FIG. 12d, leads 222a,b, 224a,b and 226a,b are provided and respectively connect to corresponding ones of each of the upper and lower arcuate segments 214a,b, 216a,b and 218a,b. The leads 222a,b, 224a,b, and 226a,b connect through the printed circuit board 214 within openings 223,223 which are partially plated continuously with the arcuate segment to which the respective lead is attached. The seating means 212 further includes the three equidistantly spaced pins 232,232 which are disposed about the circuit board 214 each having a top surface 234 disposed slightly above the upper surface of the upper arcuate segments by about 5 thousands of an inch and each having a lower portion anchored to the frame 159 in a dielectric support material, such as one made from a phenol base. The top surfaces 234,234 of each of the pins 232,232 engage and support the lens block when it is placed within the shouldered opening 174 of the blocking ring 142 and thus support the base of the block slightly above each of the upper arcuate segments.
Referring now to FIGS. 13a and 13b, and in particular to the circuit which carries out the determination of proper seating for the lens block 176, it should be seen that each of the upper arcuate segments 216a, 218a and 220a are effectively separate capacitors whose capacitance is determined by the distance the bottom surface 175 of the block is located relative to them. By monitoring the capacitance of each upper segment, a determination can be made as to whether the position of the bottom surface 175 of the block is flushly seated within the shouldered opening 174 of the blocking ring 142. The upper arcuate segments 216a, 218a and 220a are each respectively separately connected to individual voltage sources V 1 , V 2 , V 3 which are passed through respective amplifiers 236, 238 and 240 and then through associated resistors R1, R2, and R3 to apply a known voltage to each of the upper arcuate segments of about 20 volts. The voltage sources V 1 , V 2 , V 3 are generated by a power supply circuit (not shown) which supplies alternating current at phases 120 degrees apart from one another to the input lead of each of the amplifiers 236, 238 and 240. The three phase arrangement of the power supply is intended so that the net voltage between the arcuate segments at any given point in time is equal to zero. Junctions 242, 244 and 246 connect the leads of each arcuate segment 216a, 218a and 220a to a peak detector 248. The output of the peak detector is connected to a comparator 250, the resultant logic of which comparator is input to the central processor 24 at the input/output subcontroller 54. The peak detector is comprised of three diodes 252, 254 and 256 with the input end of each of each diode respectively connected through lines to each of the junctions 242, 244 and 246 and having the output line of each diode connected in parallel with one another at junction 251. Thus, the highest inputted voltage passing through each of the three diodes of the peak detector, reverse biases the remaining two diodes and causes the highest voltage passing through the open diode to be the input voltage to the comparator 250. To stabilize the output voltage signal from the open diode, a capacitance circuit 258 is provided at the junction 251.
A reference voltage V B is applied to the comparator 250, and against this reference voltage, the voltage V A taken from the open diode is compared such that a resultant voltage V 0 equalling the difference between V A and V B is calculated. A LOGIC 1 condition is generated, if, for example, V A is greater than or equal to V B , thereby making V 0 greater than or equal to PG,31 0, and a LOGIC 0 condition being generated if V A is less than V B , thereby making V 0 a negative number. Thus, the largest existent distance between the bottom face 175 of the block and each upper arcuate segment 216a, 218a and 220a is determinable by measuring voltages at junctures 242, 244 and 246 and comparing the highest determined voltage to a reference voltage which corresponds to a maximum allowable distance. This is made possible through the capacitance of the associated arcuate segments being ultimately controlled by the proximity of the metallic undersurface 175 of the lens block 176 since capacitance is inversely proportional to distance.
The lower arcuate segments 216b, 218b and 220b are provided for the purpose of eliminating voltage potentials on the lower surfaces of the upper arcuate segments 216a, 218a and 220a, leaving the sole capacitance in the circuit to be between the between top surfaces of the upper arcuate segments and the under surface 175 of the lens block 176. For this purpose, voltage follower means 260, 262 and 264 are provided and each has its input line connected respectively to the junctions 242, 244 and 246, with each output line being connected respectively to associated ones of the leads 222b, 224b and 226b of the lower arcuate segments 216b, 218b and 220b.
Each of the voltage follower means as best illustrated in FIG. 13b is an operational amplifier having an input voltage taken at respective ones of the junctions 242, 244 and 246 such that the output of each of the amplifiers follows the voltage applied at each of the upper arcuate segments 216a, 218a and 220a thereby balancing the voltages on the opposed faces of the upper and lower arcuate segments.
In summary, it is important that the block be properly seated prior to injecting the blocking adhesive. Improper seating will result in unwanted prism and/or the wrong lens thickness. In order to ensure proper seating of the block, a special sensor is employed. The sensor operates by detecting the capacitance between three capacitor sensing plates and the block. The capacitor plates are driven by a symmetrical three phase sinusoidal signal source through separate series resistors. A three phase capacitive coupling to the block tends to make the block voltage zero with respect to ground (the block is at virtual ground) because the vector sum of a symmetrical three phase signal is zero. Capacitance, which is inversely proportional to distance, is detected by measuring the peak voltage at each capacitor plate. When the block is seated properly, the capacitance is maximum, and the peak voltage is minimum. All three plate voltages are connected to a common peak detector through separate diodes. Thus, the peak detector output follows the highest input voltage. In other words, the block must be seated close to all three plates for the detector to have a minimum acceptable output. A comparator signals the controller when the detector output is low enough. The plate capacitance may be small compared to other stray capacitance. In order to minimize the undesirable effects on the stray capacitance, standard guard techniques are employed.
Operation of the complete system is illustrated by the flowchart of FIGS. 14a and 14b. The process is started by switching on the machine at the appropriate power ON switch (Step 266) which causes the downloading of the EXECUTABLE program into RAM and the heating elements 200 in the reservoir 18 to be energized and the blocking material B to take a liquid form. When the apparatus is powered up, the pick and place device 10 is initialized by raising the traveler arm 76 and moving it past a sensor 71 fixed to the base and thereafter moving the arm a predetermined distance from the sensor to a park location as illustrated in FIG. 6b in dotted line to keep the arm to keep clear of both the alignment and blocking rings 8 and 142 during the alignment process. Along with the initialization of the pick and place means is the simultaneous initialization of the locating pin 196 of the rotatable part in the blocking stand. (Step 268) Job description information is then accounted for by either manual entry of the job number through the keypad 13 (Step 272), or (Step 270) by on-demand downloading of data from a host computer through serial port 50 by entering a known JOB NUMBER through the Keypad or by using a bar code scanner (Step 272). The specific parameters of the job intended to be worked on are next caused to be displayed by the user depressing the ENTER key. (Step 276) As needed, the user may use the projected data to select the specifically called for lens type from a list of differing lens types. As will be discussed in greater detail with reference to FIGS. 15a and 15b, the graphic display options provided thereafter in the EXECUTABLE program are, for the most part, driven by the lens type that is called for by the prescription information. For the moment, it is only necessary to understand that the graphic display, in addition to displaying the called for parameters of a given job, also generates a full scale target 350 as depicted in FIG. 11, used to effect correct alignment of the lens blank relative to the ring 8.
Once a desired job with its associated data and target are displayed in the viewing port 30 in a manner best seen in FIG. 1a, the operator thereafter places the lens blank 14 on the alignment ring 8 and causes the edges or multifocal features of the blank to be positioned within the projected target thereby referencing the lens blank to a given prescribed orientation ultimately taken relative to the lens block to which it will be bonded. (Step 278) It is noted that the EXECUTABLE program for any given job calls up data on the right lens first, followed in turn by the respective data for the left lens of a given job.
The lens block 176 is also aligned relative to the locating pin(s) and positioned within the blocking ring 142 of the blocking station 16 such that the alignment opening 177 formed on the surface 175 receives the locating pin 198. To aid in achieving such alignment, a notch or other indicator may be formed on the block which aligns with a corresponding orientation marking made on the blocking stand 144. (Step 280) The user then prompts the machine by pressing the appropriate key on the keypad 13 to initiate the transport of the aligned lens blank to the blocking station 16 for placement on the blocking ring 142 in the precise orientation relative to the base that it maintained on the alignment ring 146. (Step 282) In response to the user prompting the MOVE command, the transport arm 76 is moved from its park position to the X1 position over the alignment ring 8, vacuum is applied to the gripper 82 and pressurized air is introduced through the appropriate chamber of the pivot actuator 80 to cause the traveler arm 76 to rotate downward into engagement with the upwardly facing surface 84 of the lens blank 14. Also, the normally up condition of the sliding rod 188 of the blocking station vertical actuator 190 is caused to move to its lowered position while at the same time, the pivotal gate 208 is moved to its closed to flow position. (Step 284) It is noted that in the case where a sensor type seating device is used, such as discussed with reference to FIGS. 12c and 12d, any improper seating signal must be remedied first before the blocking process is allowed to continue. Also, if there is an off-axis parameter for the prescription of the specified lens (Step 286), the block is rotated by the stepper motor 180 acting through the rotatable part 178 to precisely rotate the block in the prescribed angular orientation relative to the blocking ring 142 which surrounds it. (Step 288)
The traveler arm 76 is caused to be raised by the energization of the appropriate chamber of the actuator and shortly thereafter the traveler arm stepper motor 64 is caused to rotate a given number steps to thereby linearly move the gripper 122 from the X1 location adjacent the blocking ring 142 to the X2 location over the blocking ring 142. (Step 290) Thereafter, the appropriate expansion chamber of the actuator 80 is caused to be energized to thereby lower the traveler arm to place the lens blank squarely on the blocking ring 142. (Step 292) With the traveler arm lowered and effectively clamping the lens blank to the blocking ring 142, the user again prompts the controller by depressing a FILL command key (Step 294).
Once the operator presses the FILL keypad button, pressurized air is introduced through the line 204 by the controlled energization of one of the solenoid valves in the bank 66 thereby causing the liquified bonding material to fill the gap G between the lens blank and its corresponding block. The user continues to cause the flow of liquified blocking material into the gap by holding the FILL command key down until such time as the bonding material fills the void between the lens and the block, whereupon he or she releases the FILL key (Step 298). If the FILL key is not pressed again within a given interval, for example, five seconds (Step 300), then the controller begins counting through a second interval to allow for hardening of the bonding material B, which second interval is approximately 20 seconds depending on the characteristics of the bonding material B. (Step 302)
The solenoid valve controlling the introduction of pressurized air through the line 204 is pulse width modulated by the central controller during the second interval (Step 304) thereby maintaining a reduced pressure in the inlet 148 during the hardening process. This prevents the backflow of liquified bonding material through the fluid passage 166 during the hardening process and thus prevents the formation any undesirable void.
After a time period allowing for filling and hardening, the applied vacuum to the gripper 118 is stopped and the appropriate chamber of the pivot actuator 80 is energized thereby raising the arm away from the lens blank and the actuator 188 is energized to lift the now bonded lens blank with the block out the blocking station 16. (Step 306) During the hardening period as provided for in Step 302, the program allows for the alignment phase of the next lens to be conducted by presenting the target for the left lens, for example, in a two lens job to be presented on the display screen for alignment by the user such that once the hardening process is complete the transport process on the now aligned following lens can be effected.
Referring now to FIG. 15, and in particular to the program responsible for displaying the projected graphic target and related data on the display screen 5, it should be seen that the program is essentially driven by data input to it either initially by a host computer entered through the keyboard by a user. It should be noted that in either case the user may, despite whatever data exists in the file of the central controller 24, subject this data to editing by using the keypad 13.
Data corresponding to the specific prescription called for is assigned to each lens blank to be blocked. This data is displayed on the screen 5 and includes the following list of parameters arranged on the screen as best illustrated in FIG. 11:
(1) JOB NUMBER:
(2) EYE:
(3) TYPE:
(4) DIAMETER:
(5) SEGMENT:
(6) INSET:
(7) DROP
(8) AXIS:
(9) A DECENTRATION:
(10) B DECENTRATION:
(11) FRONT:
(12) BLOCK TYPE
The data input for each of the parameters (1)-(11) above, will affect the type, size and the presentation of the target 350 which is ultimately presented on the screen. The target 350 is created using commercially available graphics routines which create the box-like target using the input parameters for the job to be blocked, which in the case of the target box 350 is the DIAMETER parameter. It is noted that two boxes are displayed, the solid outer box is the true blank diameter with a inner slightly smaller dashed-line box defining a backup diameter for irregularities in the edge blank which may cause difficulties in the alignment using only the solid line outer box. Using a combination of sides from either of the dashed or solid lined boxes will qualify the lens for proper seating within the given target area. (Step 314)
The SEGMENT parameter corresponds to the width of the secondary focal lens, if any is required by the prescription. Before any segment calculation can be made however, the program must first determine whether the lens is of one of the types referenced in the program, namely, flat-top, round segment, progressive, aspheric or special lens. (Step 316) If the lens is one in which a secondary or third lens is involved, then a required value for the SEGMENT width parameter must be entered. (Step 318) If the lens is not one of these types, then the program assumes the involved lens is a single vision lens (Step 320) and accounts for the next parameter.
FIGS. 16 and 17 depict how segment length information is used by projecting an open box 352 having a width w defined by a segment length 354 which is used by the computer to project a target area in which the secondary lens is to be aligned. In the case of a progressive lens, the lens is manufactured with reference markings which include crosshair, axis line, and a center dot marking the geometric center of the lens blank and its proper axial orientation. In this case, the graphic display as illustrated in FIG. 18 projects a target line 356 on which is centered the marking for the lens.
INSET and DROP parameters which are particular to multifocal lenses are next accounted for. As illustrated in FIG. 20, the INSET parameter is the distance H of the secondary lens taken from the center of the blank BC to a reference point usually the horizontal middle of the secondary lens or a vertical marking in the case of a progressive lens. The DROP parameter is the measurement V of the secondary lens from the blank block center BC to either the top edge of the secondary lens in the case of a flat top bifocal or to the horizontal marking in the case of a progressive lens (Step 322). A DECENTRATION and B DECENTRATION which respectively represent vertical displacement and horizontal displacement of the lens center relative to the block center may optionally be provided for the purpose of producing prismatic power. (Step 324)
The AXIS parameter is next accounted for. Here, a value for the orientation of a cylinder axis relative to its orientation on the block is determined as between 0 and ±180 degrees. FIG. 19 illustrates a target for a single vision lens with zero AXIS displayed as a simple square with an axis line 358 in a 0 degree position indicating that the cylindrical axis is disposed therealong. (Step 326)
The final parameter check is made with regard to the data entered for the FRONT value describing the curvature outwardly disposed convexed surface 86 of the lens blank. The FRONT value is the curvature in diopters usually provided on the package label of the lens. The FRONT parameter is used in the determination of a desired curvature for the lens block 176. It is desired to obtain generally parallel relationship between the outwardly disposed exterior surface 86 of the lens blank 16 and the opposing surface 173 such that any shrinkage occurring as a result of the blocking material hardening, will occur uniformly throughout the gap G. To these ends the computer using the value for the inputted FRONT parameter compares the value for the FRONT curvature against a series of ranges for the purpose of determining in what range the indicated FRONT value should lie. (Step 328) As illustrated in FIG. 18, the result of this determination is the presentation of a message 360 on the screen indicating that at least in this case Number 4 block is required. (Step 330) The following table is an example of the different block sizes available for a given diopter range for the FRONT curvature of the lens.
______________________________________Block Size (Diopters) Range (Diopters)______________________________________2 diopter block 0.5 to 3.04 diopter block 3.1 to 5.96 diopter block 6.0 to 7.98 diopter block 8.0 to 9.910 diopter block 10.0 to 12.0______________________________________
With the appropriate block size now determined and the appropriate message at 360 generated, the user then selects the appropriate block size from a selection of blocks that are provided and places it into the blocking ring in the manner previously discussed hereto with reference to FIGS. 14a and 14b. As further illustrated in FIG. 18, in the case where data is downloaded from a host computer, such information may include a graphic outline 357 of the lens shape as part of the graphic displayed.
After surfacing of the interior surface 84 of the lens blank is accomplished, detaching the block from the lens may be accomplished by providing a deblocking means 400. The deblocking device 400 as illustrated in FIG. 21 is provided and includes two jaw members 402 and 404 one of which jaw members is moveable relative to the other and connected to an actuator 406 moveable between a retracted and an extended position corresponding respectively to the jaws being opened to receive the now blocked lens blank and an extended position wherein a moveable jaw 404 is caused to cleave the bond interface between the outwardly disposed surface 86 and the harden bonding material B. The actuator 406 is connected to a pressurized air source and is caused to move the slidable jaw 404 between its extended and retracted position by the control opening and closing of a valve interposed between the actuator and a pressurized air source along a pressurized air line.
By the foregoing, an automated lens blocking apparatus has been disclosed in the preferred embodiment. However numerous modification and substitutions may be had to the invention without departing from the spirit of the invention. For example, as disclosed the apparatus includes a single blocking station but it is not outside of the purview of the invention to provide a double blocking stations each orientated side by side with one another and extend the length of the way 74 of the pick and place device to accommodate the additional travel needed by the traveler arm 76. Also, the listing of specific lens characteristics which makes up part of the graphic image need not be limited to those disclosed above, but may include other characteristics, such as, any desired PRISM characteristic.
According the invention has been described by way of illustration rather than imitation.
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An apparatus for blocking an ophthalmic lens blank for working the lens includes an alignment station for supporting and aligning the lens blank relative to a target image and a transport means for moving the lens from the alignment station to a blocking station while maintaining lens orientation. The blocking station includes a support for a lens block, support for the lens, and a mechanism for injecting heated liquid bonding material between lens and block which solidifies on cooling to join the lens and block.
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BACKGROUND OF THE INVENTION
The invention relates to the surface state of tires particularly their protection against the consequences of the various antioxidants and antiozonants that they contain migrating to the surface.
It is known that certain polymers, in particular vulcanized rubber compositions based on diene polymers containing ethylenic double bonds in their main chain, are very sensitive to the action of ozone.
When an article made with such a diene elastomer composition is subjected to the action of a stress in the presence of ozone, the deleterious effect of the ozone is manifested by the appearance of surface cracks oriented perpendicularly to the stress direction. If this stress remains, or each time it occurs, the cracks grow and may cause complete failure of the article.
In order to limit this degradation, antiozone chemical compounds as well as waxes are commonly incorporated into elastomer compositions. The antiozone chemical compounds slow down the formation and propagation of the cracks under static and dynamic stressing conditions. The waxes provide additional static protection by forming a protective surface coating.
These means of combating degradation due to ozone have proved their effectiveness. However, the most effective antiozone compounds are also characterized by a very high tendency to migrate through their polymeric substrate and end up staining and coloring the adjacent surfaces. For example, yellowish or brown stains appear at the surface of the tire walls. This phenomenon is called "coloration". Surface migration of the waxes also modifies the external appearance of the surfaces of elastomer compositions, making them dull and gray. This phenomenon is called wax "efflorescence".
These migrations are particularly damaging in the case of "white-walled" tires but they may also seriously compromise the attractive appearance of "black-walled" tires whose external surfaces lose their shiny appearance and acquire a dull grayish one.
In order to preserve the attractive appearance of the white walls of tires up to the moment when they are put into service, protective coatings are usually employed. These coatings are applied to the walls after the tires have been manufactured. They are mainly based on polyvinyl alcohol ("PVA") flexibilized by plasticizers and contain "barrier" agents, for example mica particles, in order to slow down the migration of these chemical antiozonants and these waxes to the surface. U.S. Pat. No. 5,149,591 describes one of these protective coatings. However, these coatings are visible, thick, have limited mechanical strength and must be removed before the tires are put into service. The present invention proposes to solve these problems.
The mechanical behavior of uncrosslinked polymers varies as a function of temperature, from a glassy region at low temperatures, where the behavior is glass-like, that is to say rigid and brittle, to a fluid-flow region at elevated temperatures. Between these two regions is a region called the "rubbery plateau" where the behavior is rubber-like, that is to say close to that of an elastomer, as long as the molecular weight of the polymer is high enough for there to be entanglements (see: "Viscoelastic Properties of Polymers", John D. Ferry, 3rd ed., John Wiley & Sons, 1980, especially Chapters 10, 12 and 13).
The temperature at which the mechanical behavior of the polymer changes from this glass-like, rigid and brittle behavior to this rubber-like behavior is called the "glass transition temperature" (or "T g ") of the polymer. This glass transition temperature is an essential characteristic of polymers.
The glass transition temperature is usually determined by differential enthalpy analysis (see "Introduction to Thermal Analysis: techniques and applications", Michael E. Brown, Pub. Chapman and Hall, New York, 1988). This technique, more commonly known by the initials DSC (Differential Scanning Calorimetry), consists in determining the variations in specific heat of a specimen whose temperature is being raised. It demonstrates the presence of transitions or reactions which are accompanied by the release of energy (exothermic transition or reaction) or absorption of energy (endothermic transition or reaction). The glass transition is an endothermic transition.
SUMMARY OF THE INVENTION
The subject of the invention is an aqueous composition intended to form an antimigration and antiozone protective coating on the external surface of a tire, this coating being such that it does not have to be removed when these tires are put into actual service.
The aqueous composition according to the invention comprises an aqueous emulsion of at least:
(a) a polymer called constituent I, said constituent I being a homopolymer or copolymer based on at least one monomer chosen from the group of acrylic, methacrylic and vinyl esters and having a glass transition temperature below 0° C.; and
(b) a constituent II chosen from the group consisting of a hydrophilic silica and a homopolymer or copolymer based on at least one monomer chosen from the group of acrylic, methacrylic and vinyl monomers, said homopolymer or copolymer having a glass transition temperature above 25° C.
The constituent I chosen may especially be a styrene/butyl acrylate copolymer having a styrene content of the order of 20% by weight. The glass transition temperature of such a polymer is -21° C.
Such an aqueous composition enables a continuous, flexible and adherent coating to be formed on the surface of the tire, even in the absence of plasticizer. This coating discourages all the antiozonants present in the rubber compounds of the tire from migrating to the surface, without it being necessary to add a barrier agent such as mica, and, because of its presence, it discourages degradation due to ozone. The rubber-like behavior of the coating obtained enables it to withstand all the deformations undergone between manufacture and sale of the tires, and even thereafter
The presence of the constituent II reduces the stickiness which a coating would have were it formed with the above component I as the sole main constituent. This stickiness is detrimental to the mechanical strength of the coating and makes it sensitive to dust and to soiling since it readily becomes dirty.
The constituent II may be a hydrophilic silica having a weight content of between 5 and 25 parts per 100 parts of dry polymer. Preferably, the silica content is between 10 and 15 parts. In addition to its effect on stickiness, the silica enhances the mechanical properties of the coating formed.
According to one embodiment, the constituent II is a homopolymer or copolymer based on at least one monomer chosen from the group of acrylic, methacrylic and vinyl monomers, said constituent II having a glass transition temperature above 25° C.
Such a constituent II may especially be a copolymer or blend of homopolymers of ethyl acrylate and methyl methacrylate having an ethyl acrylate proportion by weight of the order of 55%, or of polyvinyl acetate. In either case, the proportion by weight of the constituent II is between 35 and 55 parts by weight per 100 parts of dry polymer. Below 35 parts, the stickiness of the coating formed is often still pronounced and above 55 parts the coating obtained, being stiff, cannot easily follow the deformations undergone by the tires.
The constituent II may also be polyvinyl alcohol in the proportion of from 10 to 50 parts by weight per 100 parts of dry polymer.
According to another example, the constituent II is poly(N-vinyl-2-pyrrolidone) in the proportion of from 10 to 40 parts by weight per 100 parts of dry polymer.
In these last two cases, when the amount of constituent II exceeds the maximum values indicated, the coating formed becomes too rigid as well as too sensitive to the action of water.
The constituent II may also be a polyvinyl alcohol/poly(N-vinyl-2-pyrrolidone) copolymer.
According to another variant of the invention, the aqueous composition, in addition to the constituent I and the constituent II composed either of a copolymer or blend of homopolymers of ethyl acrylate and methyl methacrylate having a proportion by weight of ethyl acrylate of the order of 55%, or of polyvinyl acetate, may contain a constituent III consisting of a water-soluble vinyl homopolymer or copolymer chosen from the group of polyvinyl alcohols, poly(N-vinyl-2-pyrrolidone)s and vinyl alcohol/N-vinyl-2-pyrrolidone copolymers.
Adding this constituent III improves the wetting of the compositions on the rubber surface and the mechanical strength of the coating formed after drying.
Advantageously, this variant of the composition according to the invention, with at least three constituents, I, II and III, has, per 100 parts of dry polymer:
(a) from 50 to 75 parts of constituent I;
(b) from 15 to 28 parts of constituent II; and
(c) from 7 to 25 parts of constituent III.
The various alternative forms of the aqueous composition according to the invention may all advantageously contain a hydrophilic silica in the proportion of from 5to 30 parts by weight per 100 parts of dry polymer. This silica has a thixotropic effect which makes it easier to apply the aqueous composition to the rubber surface. Moreover, the amount of silica present in the composition enables the appearance of the coating obtained after drying to be changed from a shiny appearance (for an amount from 0 to 10 parts approximately) to a matt appearance (for an amount of the order of from 20 to 30 parts), passing through all possible gradations.
Advantageously, the aqueous composition according to the invention may also include surfactants in order to promote wetting on the rubber surface.
The above compositions have the advantage of producing transparent coatings which do not conceal the various markings placed on the walls of tires during their manufacture and their testing. It is thus possible for these coatings to be used for protecting white walls.
In order to give a particular attractive character to the protected rubber surface, the aqueous composition according to the invention may also contain pigments. In particular, these pigments may be carbon black in order to prevent whitening of the coating obtained after prolonged contact with water or in regions of large deformations.
In a known way, this aqueous composition may also include antifoaming agents in order to make it easier to apply with a gun.
In order to prepare an aqueous composition according to the invention, the following are put in succession into a container:
the water;
the silica, if necessary;
the carbon black or any pigment, if necessary;
the surfactant;
the antifoaming agent, if necessary;
the polyvinyl alcohol or polyvinyl pyrrolidone, depending on the case, and if necessary;
the constituent I or the constituents I and II, depending on the case.
The constituents of the aqueous composition are put in cold. Known means are used to stir until the substances of the aqueous composition are completely dispersed, then the emulsion obtained is filtered through a 150 μm nylon cloth in order to remove any small particles of poorly dispersed material.
The subject of the invention is also a method for the antimigration and antiozone protection of a tire surface, in which:
a thin layer of an aqueous composition as above is applied to said rubber surface;
said layer is allowed to dry until a protective coating is formed.
The application is performed by any known means, especially by a brush, a roller or by spraying with a gun.
In order for the coating formed to have good mechanical strength after the aqueous composition has dried, it is essential to apply the composition in one or more successive layers. Good results are obtained with dry coatings having a total thickness of between 1 and 30 μm. Preferably the coatings have a thickness of from 3 to 15 μm.
Preferably it is applied to the external surface of new tires in order to guarantee non-coloration of the tires by surface migration of chemical antiozonants, at least throughout all the transporting, storage and testing operations until they are put into service.
In addition, since the coating formed has a high mechanical strength, this coating can withstand all the above operations and remain in place after the tires have been put into service and can, by its presence, thus ensure that an attractive high-quality appearance and effective ozone protection are maintained for several thousands of kilometers and/or for several months.
Even if the coating may be sensitive to the abrasion and knocks which the tire walls may suffer in service, it has the other advantage of being removed by wearing away in the form of a fine powder without disbondment, so as to be virtually undetectable by eye.
Of course, the protective coating cannot be effective on all the parts of the tire in permanent contact with the ground, such as the tread, since in this case it wears away very rapidly. However, it is highly advantageous to deposit it over the entire surface since it coats and protects the tread before it is used and, thereafter, continues to act on all the other parts which are not in contact with the ground, such as the walls and the bottoms of the grooves of the tread patterns.
DESCRIPTION OF PREFERRED EMBODIMENTS
The invention is illustrated by means of the examples below, which should not be construed as limiting its scope.
In the examples, the properties of the compositions are evaluated as follows:
"coloration/efflorescence": test of the ability of the coating to discourage surface migration of all the antiozonants;
"handling": test of the mechanical strength of the coating when handling a tire and when fitting it onto a rim (this test imposes extensional deformations on the surface of the walls greater than 40%);
"dynamic behavior": test of the mechanical strength of the coating under dynamic stressing, 12000 kilometers on a rolling road with an imposed deflection of 35% at 60 kilometers per hour; this test imposes a dynamic extensional deformation on the surface of the walls of the order of 15%;
"rubbing": test of the mechanical strength of the coating during operations of tires rubbing against one another;
"sidewalk chafing": rubbing of the coated wall of a tire against a sidewalk over a few meters; test to see how the coating is removed under mechanical rubbing, whether by wearing away as a powder, or disbandment;
"water": test of the resistance of the coating during prolonged immersion in water, this being a simulation of long-term storage of a vehicle in a parking lot in a puddle of water;
"heat": 50° C. oven test of the resistance of the coating over at least 6 months;
"mechanical behavior after aging": weather exposure of coated tires followed by a test of the mechanical strength of the coating;
"aging/appearance": visual observation of the aesthetic appearance of the coating after deposition and during aging;
"washing": test of the resistance of the coating to washing by rubbing it with an aqueous solution to which soap has been added;
"deposition": assessment of the ease of application of the composition to a rubber surface.
Table 1 gives the formulations of the coatings tested and Table 2 gives the results obtained. The formulations are given on the basis of 100 parts of dry polymer.
TABLE 1__________________________________________________________________________Composition A B C D E F G H I J K L__________________________________________________________________________PVA.sup.(1) 100 40 16PVP.sup.(2) 30 16 15StBuAc.sup.(3) 100 100 62 60 70 65 62 60 63 63 62EA/MM.sup.(4) 35 38 40 21 21PVAc.sup.(5) 38 23silica.sup.(6) 16 13 21 12 22 22 22glycerine 16surfactant.sup.(7) 30 9 9.0 9 13 10 13 17 12 9 9 9antifoaming agent.sup.(8) 12 12 12 26 20 12 17 12 12 12N772 black 8 8 8total water 1800 250 370 630 1200 1000 310 530 690 630 630 620__________________________________________________________________________ .sup.(1) polyvinyl alcohol: Rhodoviol 25/140 (RhonePoulenc) (T.sub.g : +49° C.***); .sup.(2) polyvinyl pyrrolidone: Luviskol K90 (BASF) (T.sub.g : approx. +175° C.*); .sup.(3) aqueous emulsion having 50% of a styrene/butyl acrylate copolymer: Rhodopas GS 125 (RhonePoulenc) (T.sub.g : -21° C.**); .sup.(4) aqueous emulsion having 40% of an ethyl acrylate/methyl methacrylate copolymer (T.sub.g : +34° C.***); .sup.(5) aqueous emulsion having 54% of polyvinyl acetate (T.sub.g : 28 t 31° C.*); .sup.(6) hydrophilic amorphous silica: Aerosil 200 (Degussa); .sup.(7) nonionic surfactant: octyl phenyl polyethylene oxide (Cinnopal OP9 from Henkel); .sup.(8) antifoaming agent: BYK 070 (BYK); *Reference: Encyclopedia of Chemical Technology, 3rd edition, Vol. 23; **Reference: RhonePoulenc measurements; ***Reference: internal measurements.
TABLE 2__________________________________________________________________________Composition A B C D E F G H I J K L__________________________________________________________________________coloration efflorescence +++ ++ ++ ++ +++ +++ +++ +++ +++ +++ +++ +++handling --- + ++ ++ ++ ++ ++ +++ +++ +++ +++ +++dynamic behavior --- +++ +++ +++ ++ ++ +++ +++ +++ +++ +++ +++rubbing + - ++ ++ ++ ++ ++ +++ +++ +++ +++ +++sidewalk chafing --- + ++ ++ ++ ++ ++ +++ +++ +++ +++ +++water --- +++ +++ + + + +++ +++ +++ +++ +++ +++heat --- + ++ +++ ++ +++ +++ +++ +++ +++ +++ +++aging/mechanical behavior --- ++ ++ ++ + + +++ +++ +++ +++ +++ +++aging/appearance - -- ++ + ++ ++ ++ +++ +++ +++ +++ +++washing --- +++ +++ +++ + + +++ +++ +++ ++ ++ ++deposition +++ + ++ + ++ ++ ++ ++ ++ +++ +++ +++__________________________________________________________________________
The assessment scale used in the tests is as follows:
______________________________________excellent +++ inadequate -very good ++ very inadequate --satisfactory + unacceptable ---______________________________________
All the coatings formed with the compositional examples presented are very good to excellent in the "coloration/efflorescence" test.
Example A relates to an aqueous composition based on polyvinyl alcohol (PVA) with plasticizer added. This polymer has a high glass transition temperature (+49° C.) and does not impart rubber-like behavior to the coating at the temperatures at which tires are usually handled and stored. The coating obtained is excellent in terms of migration resistance and very good in respect of its ease of application; on the other hand, it is unacceptable in all the tests where large deformations are imposed on it, statically and dynamically, because it is too rigid, despite the presence of the plasticizer. This rigidity leads to disbondment from the rubber surface to which it is applied.
Example B provides the simplest solution based on a styrene/butyl acrylate copolymer. This polymer has a glass transition temperature of -21° C. and consequently the coating obtained has a rubber-like behavior and is greatly superior to the previous one in all the mechanical strength tests under high static and dynamic deformations. However, it is only satisfactory in the handling test, inadequate in the rubbing test and very inadequate in terms of appearance in the aging test because of an undesirable stickiness which makes it sensitive to rubbing and to becoming dirty.
Composition C is a first solution which corrects the stickiness, by the addition of silica. The coating obtained is very good to excellent in all the tests.
Another solution is given by coating D, by means of polyvinyl acetate. Compared to coating C, D is superior in the handling and heat resistance tests but is only acceptable in terms of water resistance because of whitening.
Examples E and F are based on the same styrene/butyl acrylate copolymer to which polyvinyl alcohol (E) or polyvinyl pyrrolidone (F) has been added. The behavior of these two coatings is very similar, being very good to excellent in all the tests, apart from the water-resistance, washing and aging/mechanical-behavior tests where they are acceptable. This is due to the solubility of these two polymers in water.
The choice of an ethyl acrylate/methyl methacrylate copolymer, as the second constituent in the aqueous composition, corresponds to Example G. The coating obtained is superior to the previous two in the water-resistance and washing tests. The mechanical strength after aging is also improved.
The mechanical properties and the appearance of the coating formed may be further improved by adding silica to the composition of Example G, that is Example H.
A preferred example of the aqueous composition according to the invention is Example I. Its formulation is very similar to Example H with a lower silica content, giving the coating a slightly shinier appearance. This formulation does not contain an antifoaming agent, a fact which does not degrade the film deposition properties. The coating obtained is transparent, which has the advantage of not concealing the markings placed on the wall of the tires during their manufacture and their tests. This coating is particularly suitable for protecting white walls, which it enhances by virtue of its slightly shiny appearance. It does not have to be removed when vehicles equipped with tires thus coated are put into service.
Examples J, K and L correspond to three other preferred variants according to the invention. The aqueous composition is, in this case, based on a blend of three polymers:
StBuAc+EA/MM+PVP: Example J;
StBuAc+EA/MM+PVA: Example K;
StBuAc+PVAC+PVP: Example L.
The coatings obtained are excellent in all the tests. It should be noted that resistance to washing with rubbing in the presence of soap, is slightly inferior, but it may be useful to be able to remove the coating easily in certain cases.
In all cases, the presence of silica improves the appearance of the coating obtained, giving it a slightly matt appearance (Examples H, I, J, K and L). Finally, the presence of carbon black in Examples J, K and L improves the resistance to whitening in the presence of water and to large deformations.
A final test, specifically for ozone resistance, was carried out on Example J, the test being called the "Volkswagen test". The purpose of this test is to evaluate the ozone resistance of a tire wall. It consists of a static test carried out on a section of tire two centimeters in width taken from between the bead wire and the top plies. The section thus produced is fixed to a tube 20 millimeters in radius by a brass wire. The surface deformation is of the order of 12%. The test pieces thus prepared are exposed to ozone in an oven under the following conditions:
______________________________________Ozone concentration 200 ± pphm (parts per hundred million)Relative humidity 60 ± 5%Temperature 25 ± 2° C.Duration 46 hours______________________________________
The test has been successfully passed when visual observation reveals no crack initiation.
A tire was aged for four months and then half of it protected by a coating according to the invention. Control test pieces--without a protective coating--and protected test pieces were then removed and tested.
The control test pieces show pronounced cracking. The protected test pieces exhibit no initiation of cracking in the regions protected by the coating according to the invention.
This test, the most severe of all the tests demanded by automobile manufacturers, shows unambiguously the effectiveness of the protective coating according to the invention.
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Aqueous composition intended to form an antimigration and antiozone protective coating on the external surface of a tire, comprising an aqueous emulsion of at least: (a) a polymer called constituent I, said constituent I being a homopolymer or copolymer based on at least one monomer chosen from the group of acrylic, methacrylic and vinyl esters and having a glass transition temperature below 0° C.; and (b) a constituent II chosen from the group consisting of a hydrophilic silica and a homopolymer or copolymer based on at least one monomer chosen from the group of acrylic, methacrylic and vinyl monomers, said homopolymer or copolymer having a glass transition temperature above 25° C.
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RELATED APPLICATIONS
This application claims the benefit of Provisional Application Ser. No. 60/681,427 filed May 16, 2005, titled “Debugging Software-Controlled Cache Coherence,” and Provisional Application Ser. No. 60/681,551, filed May 16, 2005, entitled, “Emulation/Debugging With Real-Time System Control”, both of which are incorporated by reference herein as if reproduced in full below.
BACKGROUND
Moore's law, which is based on empirical observations, predicts that the speed of integrated circuits (IC's) doubles every eighteen months As a result, IC's with faster microprocessors and memory are often available for use in the latest electronic products every eighteen months. Although successive generations of IC's with greater functionality and features may be available every eighteen months, this does not mean that they can then be quickly incorporated into the latest electronic products In fact, one major hurdle in bringing electronic products to market is ensuring that the IC's, with their increased features and functionality, work as intended.
IC's are designed to operate in either a test mode or an operation mode, To facilitate the configuration of the IC in a test mode, test logic is embedded on the IC which exchanges data through test pins on the IC using a standard test interface such as Joint Testing Action Group (JTAG) or a real time data exchange (RTDX) type of interface developed by Texas instruments, Inc. This test logic is typically referred to as design-for-test (DFT) technology.
One such DFT technology is a scan design which creates one or more scan chains by serially tying together internal logic such as a set of registers and flip-flops in the IC. During the test mode of operation for the integrated circuit scan data is loaded into the internal logic of the IC through the test interface. After loading the test data, the IC is instructed to perform whatever operations would be caused by the scan data being loaded into the internal logic to create a scan signature. The scan signature is then read out from the test interface and compared with expected results to determine the operability of the IC. As the amount of internal logic has increased proportional to the increases predicted by Moore's Law, the size of scan chains and scan signatures has caused scan testing to become a lengthy and costly part of the IC development. As such, the development of scan compression DFT techniques has been used to shorten the amount of time testing takes and reduce the amount of data exchanged between testing equipment and an IC.
Uninitialized register files can cause a problem for DFT techniques that use scan compression because the output of the register file is not known. This unknown output value corrupts the signature that is calculated by the scan compression logic, thus invalidating the test.
Some testing equipment is very inefficient at masking and removing unknown values. Uninitialized register files can also cause a problem for this test equipment and can increase test time and in turn increase test costs.
SUMMARY
Disclosed herein is a system and method for initializing a register file during a test period for an integrated circuit, wherein the register file has one or more input ports. A counter, when enabled, is initialized and counts the write cycles of the register file and outputs a current count value to the one or more input ports of the register file. As such, a known value is written into each address location of the register file.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 depicts an example of a system for testing an integrated circuit (IC).
FIG. 2 depicts an example of a register file which can be loaded with known values for testing.
FIG. 3 depicts an example of a register file with two write ports which can be loaded with known values for testing.
FIG. 4 depicts values that may be written into the register file of FIG. 2 .
FIG. 5 depicts values that may be written into the register file of FIG. 3 .
FIG. 6 depicts values that may be written into a register file with four write ports.
FIG. 7 depicts an example of a register file with two write ports that write to mutually exclusive portions of a register file and can be loaded with known values for testing.
FIG. 8 depicts values that may be written into the register file of FIG. 7 .
DETAILED DESCRIPTION
FIG. 1 discloses an exemplary integrated circuit (IC) 100 that is to be tested by a monitoring computer 140 . Monitoring computer 140 outputs various control signals 145 to IC 100 through test pins 105 and receives output 150 from the IC. Based on the values received from output 150 a determination can be made as to whether or not the IC 100 is working as intended IC 100 may comprise a register file 110 , a processor core 115 , and a memory 155 . Processor core 115 may have a plurality of functional units for manipulating data in a desired manner based on instructions that are input to the processor core 115 . Register file 110 may be an array of processor registers used by processor core 115 to stage data and instructions between memory 155 and the functional units of processor core 115 . The interactions between processor core 115 and register file 110 may take place through a data and communications bus 135 . Memory 155 may be a cache memory of one or more levels which may further access off-chip memory 160 to fetch any data or instructions not presently stored in memory 155 or store any data or instructions which do not fit in memory 155 any more. Memory 160 may be a random access memory (RAM), hard disk drive, or any other suitable storage device.
Within IC 100 test pins 105 may provide an input 120 to a register file 110 and processor core 115 to select the operation of IC 100 between a normal mode and a test mode. In a normal mode of operation the register file 110 is placed under the control of processor core 115 and all other test pins not corresponding to input 120 are ignored. Once an IC 100 is working as intended, the IC 100 may be placed in an electronic product and the test pin corresponding to input 120 may be permanently hardwired in the electronic product such that the IC 100 is always in the normal mode of operation. Monitoring computer 140 may provide a signal to a test pin 105 corresponding to input 120 to place the IC 100 in a test mode In a test mode of operation the register file 110 is initialized while scan data is loaded into one or more scan chains of processor core 115 through input 125 . The initialization of register file 110 may be accomplished by writing known values to all or most of the memory locations in register file 110 . Once the scan data is loaded into the one or more scan chains, processor core 115 operates as dictated by the scan data. Throughout this operation the processor core 115 may interact with the register file 110 . The resultant states of the scan chains are shifted out to the monitoring computer 140 through outputs 130 and 150 . The values input to monitoring computer 140 through output 150 are compared to expected values to determine whether or not IC 100 is working as intended.
FIG. 2 discloses an exemplary embodiment of register file 110 comprising a register file 200 , counter 205 , and selection logic 210 . Register file 200 has write clock (WCLK), address write (AW), data (D), write enable (WEN), and address read (AR) inputs and an output (O). The WCLK input may be a single bit line clock input used to time the writing of data to register file 200 , Data held on a data bus at the D input is written to the address present on an address bus at the AW input. The single bit line WEN input enables the writing of data at the D input to the address at the AW input. The data output at the O output to bus 240 comprises data read from the address held on an address bus at the AR input. Input 215 may provide a single bit clock signal, input 220 may provide a write address from an address bus, input 225 may provide a data value from a data bus, input 230 may provide a single bit write enable signal, input 235 may provide a read address from an address bus, and output 240 may provide a data output to a data bus. Inputs 215 , 220 , 230 , and 235 may be provided from processor core 115 through data and communications bus 135 . Input 225 may be provided from either the processor core 115 or the memory 155 and output 240 may be provided to either the processor core 115 or the memory 155 .
Selection logic 210 comprises one or more multiplexers (mux's), or any other selection logic, to select between inputs for testing or for normal operation of the register file 200 based on the value of a Scan Enable signal. The Scan Enable signal may be provided through test input 120 in FIG. 1 and is asserted for the duration of loading scan data into a scan chain in processor core 115 . When the Scan Enable signal is low the selection logic 210 preferably selects inputs for normal operation. As such, selection logic 210 would select inputs 220 , 225 , and 230 for the AW, D, and WEN register file inputs respectively In the normal mode of operation, the low Scan Enable signal also disables the operation of counter 205 .
When the Scan Enable signal is high, counter 205 is enabled to operate and is initialized, for example to a zero count value, and preferably begins counting up. Counter 205 is synchronized to the WCLK input of register file 200 and, as such, for each clock cycle on the WCLK input the counter 205 preferably counts up once. Also, the WCLK input may be synchronized with the input of scan data into scan chains of processor core 115 such that as each piece of scan data is loaded into a scan chain, the clock signal on the WCLK input may cycle once. When the Scan Enable signal is high, the selection logic 210 preferably selects the counter output bus 245 for the AW and D inputs, and a hard-wired high signal, for example “1”, for the WEN input for register file 200 . As such, the register file 200 is enabled to write for the duration that the Scan Enable signal is high. The value held on the D input is written to the address held on the AW input each clock cycle of the clock provided by the WCLK input. Since the value on the D input is the same as the value on the AW input, which is the value held on the counter output bus 245 by counter 205 , if the counter counts through the entire address range of the register file 200 , then the value of each address is written into each address location in the register file 200 . As such, known values are provided to register file 200 for testing. For example, if counter 205 is initialized by the Scan Enable signal to a zero value and counts up, then a value of 0x00000000 is written into address location 0x00000000, a value of 0x00000001 is written into address location 0x00000001, all the way up to a value of 0xFFFFFFFF being written into address location 0xFFFFFFFF in register file 200 as shown in FIG. 4 . Since the Scan Enable signal is asserted for the duration of loading scan data into a scan chain in processor core 115 , then as long as the longest scan chain is at least as long as the full address range of register file 200 , every location in the register file 200 would have a known value.
It is noted that while the above description was made with regard to the Scan Enable signal being a particular polarity, ire., high or low, in order to accomplish a particular task, this is not limiting. For instance, when the Scan Enable signal is high the selection logic 210 may select inputs for normal operation as opposed to selecting the output of the counter 205 for inputs AW and D and the high signal for the WEN input, as was the case in the above description. Also, counter 205 does not have to be initialized to a zero value and count up, but may also be initialized to a very high value, such as the highest address value of register file 200 , and count down.
If a register file has an address range that exceeds the length of the longest scan chain and the register file has multiple write ports a solution is provided below with regards to FIG. 3 . FIG. 3 shows an exemplary embodiment of register file 110 comprising a register file 300 , counter 305 , and selection logic 310 and 315 . In this embodiment register file 300 has two write ports with inputs AW 0 , D 0 , and WEN 0 comprising the first write port and inputs AW 1 , D 1 , and WEN 1 comprising the second write port. The remaining inputs and output are similar to those described with regard to FIG. 2 . In particular, inputs 325 and 345 and output 375 of FIG. 3 correspond to inputs 215 and 235 and output 240 of FIG. 2 respectively. Further, each of inputs 330 - 340 and 350 - 360 correspond to inputs 220 - 230 of FIG. 2 respectively. As such, inputs 325 , 330 , 340 - 350 , and 360 may be provided from processor core 115 through data and communications bus 135 . Inputs 335 and 355 may be provided from either the processor core 115 or the memory 155 and output 375 may be provided to either the processor core 115 or the memory 155 .
Selection logic 310 and 315 each comprise one or more multiplexers (mux's), or any other selection logic, to select inputs for each write port between inputs for testing or normal operation of the register file 300 based on the value of a Scan Enable signal. The Scan Enable signal may be provided through test input 120 in FIG. 1 and is asserted for the duration of loading scan data into a scan chain in processor core 115 . When the Scan Enable signal is low, selection logic 310 and 315 preferably select inputs for normal operation. As such, selection logic 310 would select inputs 330 , 335 , and 340 for the AW 0 , D 0 , and WEN 0 inputs respectively for the first write port of register file 300 , Selection logic 315 would select inputs 350 , 355 , and 360 for the AW 1 , D 1 , and WEN 1 inputs respectively for the second write port of register file 300 , In the normal mode of operation, the low Scan Enable signal also disables the operation of counter 305 .
When the Scan Enable signal is high, counter 305 is enabled to operate and is initialized, for example to a zero count value, and preferably begins counting up. Counter 305 is synchronized to the WCLK input of register file 300 and, as such, for each cycle of the WCLK input the counter 305 preferably counts up once. Also, the WCLK input may be synchronized with the input of scan data into scan chains of processor core 115 such that as each piece of scan data is loaded into a scan chain, the clock signal on the WOCLK input may cycle once. When the Scan Enable signal is high, the selection logic 310 and 315 preferably selects the counter output bus 320 for the AW 0 , AW 1 , D 0 , and D 1 and a hard-wired high signal, for example “1”, for the WEN 0 and WEN 1 inputs for register file 300 . Further note that for the first write port the most significant bit of the counter output bus 320 is hardwired to a low value 365 , for example “0”, and for the second write port the most significant bit of the counter output bus 320 is hardwired to a high value 370 , for example “1”.
For the first write port the register file 300 is enabled to write for the duration that the Scan Enable signal is high. The value held on the D 0 input is written to the address held on the AW 0 input each clock cycle of the clock provided by the WCLK input. Since the value on the D 0 input is the same as the value on the AW 0 input, which is the value held on the counter output bus 320 by counter 305 with the most significant bit of the counter output bus 320 held low, if the counter 305 counts through half of the address range of the register file 300 , then the value of each address is written into each address location in the first half of register file 300 . As such, known register file values for the first half of register file 300 are provided for testing. For example, if counter 305 is initialized by the Scan Enable signal to a zero value and counts up, then a value of 0x00000000 is written into address location 0x00000000, a value of 0x00000000 is written into address location 0x00000001, all the way up to a value of 0x7FFFFFFF being written into address location 0x7FFFFFFF in register file 300 as shown in FIG. 5
For the second write port the register file 300 is similarly enabled to write for the duration that the Scan Enable signal is high and the value held on the D 1 input is written to the address held on the AW 1 input each clock cycle of the clock provided by the WCLK input. Since the value on the D 1 input is the same as the value on the AW 1 input, which is the value held on the counter output bus 320 by counter 305 with the most significant bit of counter output bus 320 held high, if the counter 305 counts through half of the address range of the register file 300 , then the value of each address is written into each address location in the second half of register file 300 . As such, known register file values for the second half of register file 300 are provided for testing. For example, if counter 305 is initialized by the Scan Enable signal to a zero value and counts up, then a value of 0x80000000 is written into address location 0x80000000, a value of 0x80000001 is written into address location 0x80000001, all the way up to a value of 0xFFFFFFFF being written into address location 0xFFFFFFFF in register file 300 as shown in FIG. 5 .
Since the Scan Enable signal is asserted for the duration of loading scan data into a scan chain in processor core 115 , then as long as the longest scan chain is at least as long as it takes counter 305 to count half of the address range of register file 300 , every location in the register file 300 would have a known input.
FIG. 5 depicts the values that would be written into register file 300 . If register file 300 comprised a 32-bit memory, then the first write port would write values 0x80000000 through 0x7FFFFFFF into address locations 0x00000000 through 0x7FFFFFFF. The second write port would write values 0x80000000 through 0xFFFFFFFF into address locations 0x80000000 through 0xFFFFFFFF. As such, every location in register file 300 would have a known value.
It is noted that while the above description was made with regard to the Scan Enable signal being a particular polarity, ie., high or low, in order to accomplish a particular task, this is not limiting. For instance, when the Scan Enable signal is high the selection logic 310 and 315 may select inputs for normal operation as opposed to selecting the output of the counter 305 for inputs AW 0 , AW 1 , D 0 , and D 1 , and the high signal for inputs WEN 0 and WEN 1 as was the case in the above description. Also, counter 305 does not have to be initialized to a zero value and count up, but may also be initialized to a very high value, such as half of the highest address value of register file 300 , and count down.
It is noted that register file 300 may have more than two write ports, wherein hard wired values for the most significant bits of the counter output bus 320 would count through each of the write ports. For example, if there were four write ports then the two most significant bits of the counter output bus 320 would be hard wired to count through each write port and the counter 305 would count through the remaining values in the address. In particular, a first write port would have a “00” input hardwired on the two most significant bits of the counter output bus 320 , a second write port would have a “01” input hardwired on the two most significant bits of the counter output bus 320 , a third write port would have a “10” input hardwired on the two most significant bits of the counter output bus 320 , and a fourth write port would have a “11” input hardwired on the two most significant bits of the counter output bus 320 . FIG. 6 depicts the values that may be written into a register file with four write ports. In this case, counter 305 would only need to count through a quarter of the address range of register file 300 . Since the Scan Enable signal is asserted for the duration of loading scan data into a scan chain in processor core 115 , then as long as the longest scan chain is at least as long as it takes counter 305 to count a quarter of the full address range of register file 300 , every location in the register file 300 would have a known input.
It is further noted that register file 300 may have a number of write ports that is not a multiple of two. In this case combinational logic may be used to evenly divide the entire address range of register file 300 between each of the write ports. The combinational logic may provide a variable number on the most significant bits of counter output bus 320 to each write port. For example, if there are three write ports then the two most significant bits of the counter output bus 320 would have variable values on each of the write ports so as to ensure the entire address range of the register file 300 is counted to write known values into each memory location of register file 300 .
In an alternative embodiment, if a register file has an address range that exceeds the length of the longest scan chain and the register file has multiple write ports a solution is provided below with regards to FIG. 7 . The solution illustrated in FIG. 7 is different from that shown in FIG. 3 in that each write port writes to mutually exclusive portions of register file 700 . In particular, FIG. 7 shows an exemplary embodiment of register file 110 comprising a register file 700 , counter 705 , and selection logic 710 and 715 . In this embodiment register file 700 has two write ports with inputs AW 0 , D 0 , and WEN 0 comprising the first write port and inputs AW 1 , D 1 , and WEN 1 comprising the second write port. The remaining inputs and output are similar to those described with regard to FIG. 2 In particular, inputs 725 and 745 and output 765 of FIG. 7 correspond to inputs 215 and 235 and output 240 of FIG. 2 respectively. Further, each of inputs 730 - 740 and 750 - 760 correspond to inputs 220 - 230 of FIG. 2 respectively. As such, inputs 725 , 730 , 740 - 750 , and 760 may be provided from processor core 115 through data and communications bus 135 . inputs 735 and 755 may be provided from either the processor core 115 or the memory 155 , and output 765 may be provided to either the processor core 115 or the memory 155 .
Selection logic 710 and 715 each comprise one or more multiplexers (mux's), or any other selection logic, to select inputs for each write port between inputs for testing or normal operation of the register file 700 based on the value of a Scan Enable signal. The Scan Enable signal may be provided through test input 120 in FIG. 1 and is asserted for the duration of loading scan data into a scan chain in processor core 115 . When the Scan Enable signal is low, selection logic 710 and 715 preferably select inputs for normal operation. As such, selection logic 710 would select inputs 730 , 735 , and 740 for the AW 0 , D 0 , and WEN 0 inputs respectively for the first write port of register file 700 . Selection logic 715 would select inputs 750 , 755 , and 760 for the AW 1 , D 1 , and WEN 1 inputs respectively for the second write port of register file 700 . In the normal mode of operation, the low Scan Enable signal also disables the operation of counter 305 .
When the Scan Enable signal is high, counter 705 is enabled to operate and is initialized, for example to a zero count value, and preferably begins counting up. Counter 705 is synchronized to the WCLK input of register file 700 and, as such, for each cycle of the WCLK input the counter 705 preferably counts up once. Also, the WCLK input may be synchronized with the input of scan data into scan chains of processor core 115 such that as each piece of scan data is loaded into a scan chain, the clock signal on the WCLK input may cycle once. When the Scan Enable signal is high, the selection logic 710 and 715 preferably selects the counter output bus 720 for the AW 0 , AW 1 , D 0 , and D 1 and a hard-wired high signal, for example “1”, for the WEN 0 and WEN 1 inputs for register file 700 . Since each write port writes to a mutually exclusive portion of the register file 700 , none of the bits in the counter output bus 720 need to be hardwired with a high or low value. In other words, the values held on counter output bus 720 are exclusively provided by counter 705 .
For the first write port the register file 700 is enabled to write for the duration that the Scan Enable signal is high. The value held on the D 0 input is written to the address held on the AW 0 input each clock cycle of the clock provided by the WCLK input. Since the value on the D 0 input is the same as the value on the AW 0 input, which is the value held on the counter output bus 720 by counter 705 , if the counter 705 counts through the full address range of the first write port, then the value of each address is written into each address location in the portion of register file 700 corresponding to the first write port. As such, known register file values for the portion of register file 700 corresponding to the first write port are provided for testing. For example, if counter 705 is initialized by the Scan Enable signal to a zero value and counts up as long, then a value of 0x00000000 is written into address location 0x00000000 of the first write port, a value of 0x00000001 is written into address location 0x00000001 of the first write port, all the way up to a value of 0xFFFFFFFF being written into address location 0xFFFFFFFF of the first write port in register file 700 as shown in FIG. 8 .
For the second write port the register file 700 is similarly enabled to write for the duration that the Scan Enable signal is high The value held on the D 0 input is written to the address held on the AW 0 input each clock cycle of the clock provided by the WCLK input. Since the value on the D 0 input is the same as the value on the AW 0 input, which is the value held on the counter output bus 720 by counter 705 , if the counter 705 counts through the full address range of the second write port, then the value of each address is written into each address location in the portion of register file 700 corresponding to the second write port. As such, known register file values for the portion of register file 700 corresponding to the second write port are provided for testing. For example, if counter 705 is initialized by the Scan Enable signal to a zero value and counts up, then a value of 0x00000000 is written into address location 0x00000000 of the second write port, then a value of 0x00000001 is written into address location 0x00000001 of the second write port, all the way up to a value of 0xFFFFFFFF being written into address location 0xFFFFFFFF of the second write port in register file 700 as shown in FIG. 8
Since the Scan Enable signal is asserted for the duration of loading scan data into a scan chain in processor core 115 , then as long as the longest scan chain is at least as long as it takes counter 705 to count the full address range of each write port of register file 700 , every location in the register file 700 would have a known input.
FIG. 8 depicts the values that would be written into register file 700 . If each write port of register file 700 writes to a 32-bit portion of register file 700 , then the first write port would write values 0x00000000 through 0xFFFFFFFF into address locations 0x00000000 through 0xFFFFFFFF of the first write port. The second write port would write values 0x00000000 through 0xFFFFFFFF into address locations 0x00000000 through 0xFFFFFFFF of the second write port. As such, every location in the register file 700 would have a known value.
It is noted that while the above description was made with regard to the Scan Enable signal being a particular polarity, i.e., high or low, in order to accomplish a particular task, this is not limiting. For instance, when the Scan Enable signal is high the selection logic 710 and 715 may select inputs for normal operation as opposed to selecting the output of the counter 705 for inputs AW 0 , D 0 , AW 1 , and D 1 and the high signal for the WEN 0 and WEN 1 inputs as was the case in the above description. Also, counter 705 does not have to be initialized to a zero value and count up, but may also be initialized to a very high value, such as the highest address value of each write port of register file 700 , and count down.
It is noted that register file 700 may have more than two write ports, wherein for each additional write port the counter output bus 720 would simply be input to selection logic for each addition write port.
As such, disclosed above is a system and method for placing known values into a register file while loading scan data into a scan chain, This enables the use of scan compression without needing to mask and remove unknown values which reduces test time and in turn reduces test costs. It also enables the real paths to and from the register file to be tested. Preferably, the embodiments disclosed above avoid using a mux, with its associated delay and size, to bypass the register file.
While various system and method embodiments have been shown and described herein, it should be understood that the disclosed systems and methods may be embodied in many other specific forms without departing from the spirit or scope of the invention The present examples are to be considered as illustrative and not restrictive. The intention is not to be limited to the details given herein, but may be modified within the scope of the appended claims along with their full scope of equivalents.
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A system and method for initializing a register file during a test period for an integrated circuit, wherein the register file has one or more input ports. A counter, when enabled, is initialized and counts at each write cycle of the register file and outputs a current count value to the input ports of the register file to pre-load the register file to a known state.
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CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is based upon and claims the benefit of priority from prior Japanese Patent Application No. 2010-019392, filed Jan. 29, 2010, the entire contents of which are incorporated herein by reference.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention relates to knots for fishing nets, such as gill nets or trammel nets, used in fishing, and a method for manufacturing knots for fishing nets.
[0004] 2. Description of the Related Art
[0005] Conventionally, as disclosed in Jpn. Pat. Appln. KOKOKU Publication No. 57-42740, the process of manufacturing a knot for a fishing net, such as a gill net or a trammel net, includes the formation of a double knot by winding a warp twice about the loop portion of a weft, or the formation of a knot by interlacing warps and wefts. Each formation results in a large knot.
[0006] In fishing nets with such knots, a nylon monofilament double-knot fishing net is very slippery and the knot is liable to be loosened in the course of catching fish, so that the net may be easily torn while it is being lifted, allowing fish easily to escape. A knot specifically made by a complex interlacing of wefts and warps may not loosen. However, the knot will expand so that when the net is thrown into water or lifted from there, the knot may itself be caught in the net mesh. As a result, the net may become tangled, making it difficult to cast the net into the water, or the net may be torn. Moreover, the net may not open sufficiently underwater, making it difficult to catch fish. In addition, as the knot is large, it may offer greater engagement to water currents, and thus the fishing net may easily be swept along underwater, with the result that it fails to spread out smoothly underwater. Another disadvantage is that floating garbage and dirt in the water will easily cling to such a net, making operation of the net difficult.
BRIEF SUMMARY OF THE INVENTION
[0007] The foregoing drawbacks result from the knot structure. Accordingly, the invention aims to provide a fishing net configured such that movements of the upper hook, weft lifting plate, and reed of a net weaving machine are appropriately combined and changed to form a loop in a warp, a weft is then passed through this loop, and only the warp is tightly pulled to form a knot. The warps and wefts are thereby appropriately interlaced to a degree sufficient to prevent the knot from loosening easily. Furthermore, since the knots are small, knots are less likely to be caught in the net mesh, the net is less likely to be pulled by the currents, and garbage or dirt is less likely to cling to the net. The present invention also aims to provide a method for easily manufacturing such a fishing net.
[0008] The present invention relate to, a fishing net comprising a knot made by a method comprises: lifting a weft and rotating an upper hook once until a part of the lifted weft is hooked around the upper hook; hooking a warp around the upper hook from a direction opposite to that of the weft hooked around the upper hook; then half rotating the upper hook, thereby detaching the weft from the upper hook; lowering the lifting plate and rotating the upper hook one and a half rotations in a direction opposite to that of the previous rotation, thereby forming a loop in the warp; pulling middle of the warp into the loop by use of an under hook; subsequently detaching, from the under hook, the middle of the warp passed through the loop; and passing the weft into a loop portion of the middle of the warp.
[0009] The present invention relate to, a method for manufacturing a fishing net knot, comprising: lifting a weft by use of a lifting plate of a net weaving machine and rotating an upper hook once until a part of the lifted weft is hooked around the upper hook; hooking a warp around the upper hook from a direction opposite to that of the weft hooked around the upper hook; half rotating the upper hook, thereby detaching the weft from the upper hook; lowering the lifting plate and rotating the upper hook one and a half rotations in a direction opposite to that of the previous rotation, thereby forming a loop in the warp; pulling middle of the warp into the loop by use of an under hook; subsequently detaching, from the under hook, the middle of the warp passed through the loop; and passing the weft into a loop portion of the middle of the warp.
[0010] The present invention relate to, a fishing net comprising a knot made by a method comprising: lifting a weft and rotating an upper hook once until a part of the lifted weft is hooked around the upper hook; hooking a warp around the upper hook in the same direction as that of the weft; half rotating the upper hook in a direction opposite to that of the previous rotation, thereby detaching the weft from the upper hook; half rotating the upper hook in the same direction again, thereby forming a loop in the warp; pulling middle of the warp into the loop by use of an under hook; subsequently detaching, from the under hook, the middle of the warp passed through the loop; and passing the weft into a loop portion of the middle of the warp.
[0011] The present invention relate to, a method for manufacturing a fishing net knot, comprising: lifting a weft by use of a lifting plate of a net weaving machine, and rotating an upper hook once until a part of the lifted weft is hooked around the upper hook; hooking a warp around the upper hook in the same direction as that of the weft; half rotating the upper hook in a direction opposite to that of the previous rotation, thereby detaching the weft from the upper hook; half rotating the upper hook in the same direction again, thereby forming a loop in the warp; pulling middle of the warp into the loop by use of an under hook; subsequently detaching, from the under hook, the middle of the warp passed through the loop; and passing the weft into a loop portion of the middle of the warp.
[0012] The present invention relate to, a fishing net comprising a knot made by a method comprising: lifting a weft by use of a lifting plate of a net weaving machine and rotating an upper hook once until a part of the lifted weft is hooked around the upper hook; hooking a warp around the upper hook in the same direction as that of the weft; half rotating the upper hook in a direction opposite to that of the previous rotation, thereby detaching the weft from the upper hook; subsequently rotating the upper hook one and a half rotations in a direction opposite to that of the previous rotation, thereby forming a loop in the warp; pulling middle of the warp into the loop by use of an under hook; subsequently detaching, from the under hook, the middle of the warp passed through the loop; and passing the weft into a loop portion of the middle of the warp.
[0013] The present invention relate to, a method for manufacturing a fishing net knot, comprising: lifting a weft and rotating an upper hook once until a part of the lifted weft is hooked around the upper hook; hooking a warp around the upper hook in the same direction as that of the weft; half rotating the upper hook in a direction opposite to that of the previous rotation, thereby detaching the weft from the upper hook; subsequently rotating the upper hook one and a half rotations in a direction opposite to that of the previous rotation, thereby forming a loop in the warp; pulling middle of the warp into the loop by use of an under hook; subsequently detaching, from the under hook, the middle of the warp passed through the loop; and passing the weft into a loop portion of the middle of the warp.
[0014] Additional advantages of the invention will be set forth in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. The advantages of the invention may be realized and obtained by means of the instrumentalities and combinations particularly pointed out hereinafter.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING
[0015] The accompanying drawings, which are incorporated in and constitute a part of the specification, illustrate embodiments of the invention, and together with the general description given above and the detailed description of the embodiments given below, serve to explain the principles of the invention.
[0016] FIG. 1 is an explanatory side view of a net weaving machine (netting machine), illustrating a procedure for manufacturing a fishing net according to one embodiment of the present invention;
[0017] FIG. 2 is an explanatory side view of a net weaving machine, illustrating a procedure for manufacturing a fishing net according to one embodiment of the present invention;
[0018] FIG. 3 is an explanatory side view of a net weaving machine, illustrating a procedure for manufacturing a fishing net according to one embodiment of the present invention;
[0019] FIG. 4 is an explanatory side view of a net weaving machine, illustrating a procedure for manufacturing a fishing net according to one embodiment of the present invention;
[0020] FIG. 5 is an explanatory side view of a net weaving machine, illustrating a procedure for manufacturing a fishing net according to one embodiment of the present invention;
[0021] FIG. 6 is an explanatory side view of a net weaving machine, illustrating a procedure for manufacturing a fishing net according to one embodiment of the present invention;
[0022] FIG. 7 is an explanatory side view of a net weaving machine, illustrating a procedure for manufacturing a fishing net according to one embodiment of the present invention;
[0023] FIG. 8 is an explanatory side view of a net weaving machine, illustrating a procedure for manufacturing a fishing net according to one embodiment of the present invention;
[0024] FIG. 9 is an explanatory side view of a net weaving machine, illustrating a procedure for manufacturing a fishing net according to one embodiment of the present invention;
[0025] FIG. 10 is an explanatory side view of a net weaving machine, illustrating a procedure for manufacturing a fishing net according to one embodiment of the present invention;
[0026] FIG. 11A is an explanatory view showing a loose knot of the fishing net according to one embodiment of the present invention;
[0027] FIG. 11B is an explanatory view showing a tight knot of the fishing net according to one embodiment of the present invention;
[0028] FIG. 12 is an explanatory side view of a net weaving machine, illustrating a procedure for manufacturing a fishing net according to another embodiment of the present invention;
[0029] FIG. 13 is an explanatory side view of a net weaving machine, illustrating a procedure for manufacturing a fishing net according to another embodiment of the present invention;
[0030] FIG. 14 is an explanatory side view of a net weaving machine, illustrating a procedure for manufacturing a fishing net according to another embodiment of the present invention;
[0031] FIG. 15 is an explanatory side view of a net weaving machine, illustrating a procedure for manufacturing a fishing net according to another embodiment of the present invention;
[0032] FIG. 16 is an explanatory side view of a net weaving machine, illustrating a procedure for manufacturing a fishing net according to another embodiment of the present invention;
[0033] FIG. 17 is an explanatory side view of a net weaving machine, illustrating a procedure for manufacturing a fishing net according to another embodiment of the present invention;
[0034] FIG. 18A is an explanatory view showing a loose knot of the fishing net according to another embodiment of the present invention;
[0035] FIG. 18B is an explanatory view showing a tight knot of the fishing net according to another embodiment of the present invention;
[0036] FIG. 19 is an explanatory side view of a net weaving machine, illustrating a procedure for manufacturing a fishing net according to still another embodiment of the present invention;
[0037] FIG. 20 is an explanatory side view of a net weaving machine, illustrating a procedure for manufacturing a fishing net according to still another embodiment of the present invention;
[0038] FIG. 21 is an explanatory side view of a net weaving machine, illustrating a procedure for manufacturing a fishing net according to still another embodiment of the present invention;
[0039] FIG. 22 is an explanatory side view of a net weaving machine, illustrating a procedure for manufacturing a fishing net according to still another embodiment of the present invention;
[0040] FIG. 23 is a side view of a net weaving machine, illustrating a procedure for manufacturing a fishing net according to still another embodiment of the present invention;
[0041] FIG. 24 is an explanatory side view of a net weaving machine, illustrating a procedure for manufacturing a fishing net according to still another embodiment of the present invention;
[0042] FIG. 25A is an explanatory view showing a loose knot of the fishing net according to still another embodiment of the present invention; and
[0043] FIG. 25B is an explanatory view showing a tight knot of the fishing net according to still another embodiment of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
[0044] An embodiment of the present invention will now be described with reference to the drawings. FIG. 1 is a view illustrating the making of a knot as viewed from the side of a net weaving machine (netting machine).
[0045] In FIG. 1 , reference numeral 1 represents a rotatable upper hook. This upper hook 1 has an axis of rotation which extends vertically. As viewed from above, the upper hook 1 is able to rotate to the left and right about the axis in addition to tilting forward and backward. The upper hook 1 is driven by an upper hook driving mechanism (not shown) so as to have a specific movement. A hook member 1 a of the upper hook 1 projects approximately perpendicular to the axis of rotation of the upper hook 1 .
[0046] In FIG. 1 , reference numeral 4 is a lifting plate. The lifting plate 4 is driven by a lifting-plate drive mechanism (not shown) so as to lift weft 7 drawn from a shuttle 6 disposed on one side. The shuttle 6 accommodates a spool (a disk-like bobbin) 10 , described below (see FIGS. 9 and 10 ).
[0047] Disposed opposite to the lifting plate 4 with respect to the upper hook 1 is a reed 5 that draws warp 8 . This reed 5 is driven by a drive mechanism (not shown). Warp 8 is moved up and down, right and left, and forward and backward by this reed 5 , and is hooked around the hook member 1 a of the upper hook 1 . Below the upper hook 1 are a guide hook 2 for determining the drawing position for warp 8 , and a net slider 3 for guiding the woven net.
[0048] Referring to FIGS. 1 to 11 , a procedure for manufacturing a net by weaving weft 7 and warp 8 will now be described.
[0049] First, the upper hook 1 is raised as shown in FIG. 1 , and the lifting plate 4 lifts the weft 7 while the hooking member 1 a faces the reed 5 , as shown in FIG. 2 . After the lifting plate 4 lifts the weft 7 , the upper hook 1 is half rotated to the left from the position shown in FIG. 1 and brought into the position shown in FIG. 2 . The upper hook 1 is further half rotated to the left from the position in FIG. 2 to the position in FIG. 3 . Consequently, the weft 7 is hooked around the hooking member 1 a of the upper hook 1 , though the upper hook 1 returns to the position shown in FIG. 1 in the state of FIG. 3 .
[0050] Next, using the read 5 , a warp 8 in the opposite direction to the weft 7 is hooked around the hooking member 1 a of the upper hook 1 , as in FIG. 4 . In the position in FIG. 4 , the upper hook 1 is half rotated to the right so that the weft 7 is detached from the hooking member 1 a of the upper hook 1 , as shown in FIG. 5 .
[0051] Subsequently, the lifting plate 4 pushing the weft 7 upward is lowered, then the upper hook 1 is rotated one and a half rotations to the left so that the warp 8 forms a loop 8 a , as shown in FIGS. 6 and 7 . As a result of the one and a half leftward rotations of the upper hook 1 , the upper hook 1 twists the loop 8 a of the warp 8 . Consequently, the position of the upper hook 1 in FIG. 5 changes to that shown in FIG. 7 .
[0052] Next, as shown in FIG. 8 , an under hook 9 is passed through the loop 8 a from the side where the shuttle 6 is located. In this position, the read 5 is moved up and down, left and right, or forward and backward until the middle of the warp 8 is hooked around the hook 9 a of the under hook 9 , with the hook 9 a having passed through the loop 8 a as shown in FIG. 8 .
[0053] Subsequently, as shown in FIG. 9 , with the middle of the warp 8 hooked around the hook 9 a , the under hook 9 is drawn such that the middle of the warp 8 is passed through the loop 8 a and pulled toward the shuttle 6 .
[0054] Subsequently, as shown in FIG. 10 , the under hook 9 is moved so that the loop portion of the middle of the warp 8 hooked around the hook 9 a is released from the hook 9 a . Then, the warp 8 is guided below the shuttle 6 accommodating the spool (disk-like bobbin) 10 around which the weft 7 to be drawn is wound, thereby releasing the loop portion of the warp 8 . Consequently, the loop portion of the warp 8 is passed along the lower slant face and arcuate face of the shuttle 6 while the weft 7 is passed through the loop 8 a and the loop 8 a is detached from the upper hook. Thus, the knot is formed.
[0055] As a result of the foregoing procedure, a loose knot is formed from the weft 7 and warp 8 , as shown in FIG. 11A . Finally, by tightly binding the weft 7 and warp 8 , a tight knot as shown in FIG. 11B is formed and hence a specific fishing net is obtained.
[0056] Next, a procedure for weaving a fishing net knot according to another embodiment of the present invention will be described with reference to FIGS. 12 to 18 .
[0057] In this embodiment, the middle of a weft 7 is lifted using a lifting plate 4 and, in this state, as in FIG. 12 , an upper hook 1 is half rotated to the right twice until the weft 7 is hooked around a hooking member 1 a of the upper hook 1 . Subsequently, as shown in FIG. 13 , the middle of a warp 8 is hooked on the hooking member 1 a of the upper hook 1 in the same direction as the weft 7 , by moving a read 5 up and down, left and right, or forward and backward until the middle is hooked on the hooking member 1 a of the upper hook 1 .
[0058] Then, as shown in FIG. 14 , the upper hook 1 is half rotated to the left (in other words, in the opposite direction of the previous rotation) so that the weft 7 is detached from the hooking member 1 a of the upper hook 1 . In this position, the lifting plate 4 is lowered as shown in FIG. 15 .
[0059] Furthermore, as shown in FIG. 16 , the upper hook 1 is half rotated to the left to form a loop 8 a in the warp 8 . Then, an under hook 9 is inserted into the loop 8 a of the warp 8 , as shown in FIG. 17 , and the middle of the warp 8 is hooked around a hook 9 a of the under hook 9 . Next, in the same manner as described above, the middle of the warp 8 is fed into the loop 8 a and pulled out while the weft 7 is also passed through this loop to form a knot.
[0060] Thus, a loose knot, as shown in FIG. 18A , is formed. When the knot is tied more tightly at the end, a fishing net knot as shown in FIG. 18B is formed.
[0061] Next, a procedure for weaving a fishing net knot according to still another embodiment of the present invention will be described with reference to FIGS. 19 to 25 .
[0062] In this embodiment, first, as shown in FIG. 19 , a weft 7 is lifted by a lifting plate 4 and then an upper hook 1 is half rotated to the right. Subsequently as shown in FIG. 20 , the upper hook 1 is half rotated to the right until the weft 7 is hooked around a hooking member 1 a of the upper hook 1 . Next, a warp 8 is hooked around the hook member 1 a in the same direction as the weft 7 (see FIG. 20 ).
[0063] Subsequently, the upper hook 1 is half rotated to the left (i.e., opposite to the above rotating direction) so that the weft 7 is detached from upper hook 1 (see FIG. 21 ). Then, as shown in FIG. 22 , the lifting plate 4 is lowered and the upper hook 1 is rotated to the right one and a half rotations to form a loop 8 a in the warp 8 , as shown in FIG. 23 . In the same manner as described above, an under hook 9 is passed through the loop 8 a until the middle of the warp 8 is hooked around a hook 9 a of the under hook 9 (see FIG. 24 ). Then, the middle of the warp 8 is passed through the loop 8 a and pulled in the opposite direction while the weft 7 is also passed through this loop. Thus, a knot is formed.
[0064] Thus, a loose knot as shown in FIG. 25A is formed. When the knot is tied more tightly at the end, a fishing net knot as shown in FIG. 25B is formed.
[0065] Although the invention has been described in its preferred and modified forms, it is understood that the invention is not limited to the above descriptions and other various combinations are possible.
[0066] Additional advantages and modifications will readily occur to those skilled in the art. Therefore, the invention in its broader aspects is not limited to the specific details and representative embodiments shown and described herein. Accordingly, various modifications may be made without departing from the spirit or scope of the general inventive concept as defined by the appended claims and their equivalents.
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A fishing net includes a knot made by a method. The method includes, lifting a weft and rotating an upper hook once until a part of the lifted weft is hooked around the upper hook, hooking a warp around the upper hook from a direction opposite to that of the weft hooked around the upper hook, then half rotating the upper hook, thereby detaching the weft from the upper hook, lowering the lifting plate and rotating the upper hook one and a half rotations in a direction opposite to that of the previous rotation, thereby forming a loop in the warp, pulling middle of the warp into the loop by use of an under hook, subsequently detaching, from the under hook, the middle of the warp passed through the loop, and passing the weft into a loop portion of the middle of the warp.
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This application is a division of my copending U.S. application for patent, Ser. No. 764,391, filed Aug. 12, 1985 now U.S. Pat. No. 4,640,363.
BACKGROUND OF THE INVENTION
This invention relates to systems and apparatus used in conducting production tests of underwater wells from floating vessels and specifically relates to a more reliable system utilizing a new and novel bleedoff tool in the test string.
During production testing of underwater wells located in deep water, using a test system which includes a test tree similar to the TEST TREE of U.S. Pat. No. 4,494,609 to Schwendemann, pressure in the test string may become so high as to induce high axial tensile forces in the test tree and cause friction seizure of the test tree disconnect members and prevent mechanical disconnect of the test tree, with possibly disastrous results.
SUMMARY OF THE INVENTION
The subsea test tree is normally unlatched for disconnect by remotely applying hydraulic pressure through selected control lines. In the event disconnect cannot be accomplished hydraulically, a quick disconnect for emergency situations may by made by applying torque to the handling string on the drill ship, to rotate the latch section of the tree and mechanically disconnect from the test tree body, which is held against rotation by blowout preventer rams closed on the test string below the test tree.
If during test operation, the test tree body valve is closed and the handling string retainer valve is closed, well pressure from the test string will be trapped between these valves and will induce an axial tensile load on the subsea test tree which increases friction between threaded disconnect members in the test tree. If the internal tree pressure is high enough, the disconnect members in the tree latch are friction seized and locked and rotation and mechanical disconnect cannot occur. Hydraulic disconnect cannot occur even if control lines are intact because they cannot withstand the high pressure required to overcome the friction between the disconnect members. If no disconnect can be made even in an embergency situation, severe disaster may result.
A bleedoff tool of the present invention, installed between the subsea test tree and retainer valve in the handling string, may be operated by turning the handling string, to bleed and reduce the trapped high pressure directly into the riser or control lines around the retainer valve and into the handling string above. As the lower piston end of the bleedoff tool and test tree latch section cannot rotate, torque applied to the upper body end of the tool will turn the body on the piston and shear pins to open a flow passage from inside to outside the tool. Reduction of the trapped pressure will permit rotation of the tree latch section for quick mechanical disconnect and disaster will be prevented.
During well test operations, if control line integrity is lost, the retainer valve in the handling string cannot be operated to prevent all fluids in the handing string from being dumped into the riser or surrounding water as the subsea test tree is disconnected. The bleedoff tool is provided with an internal valve which closes automatically when the tool is operated to retain fluids above in the handling string. This closed vlave isolates a smaller volume of trapped fluids in the handling string, which may be bled rapidly through the bleedoff tool, providing more rapid pressure reduction and subsea test tree disconnect. Also, the smaller isolated volume will impart a much smaller upthrust or "launching" force to the handling string on disconnect of the subsea test tree.
If there is a need to rotate the handling and test strings together before operating the bleedoff tool, pull may be applied to the handling string to engage friction surfaces in the bleedoff tool and torque may now be transmitted through the tool without loading operating shear pins.
The bleedoff tool is additionally provided with a liquid filled chamber which serves as a liquid bearing providing free rotation between the bleedoff tool body and piston.
Also, the bleedoff tool of this invention is provided with equal sealed areas having a balancing effect which prevents high internal pressures from moving the piston out of the body to engage stop shoulder friction surfaces and prevent free relative rotation of the body around the piston.
One object of this invention is to provide a more reliable deep water production well testing system for underwater wells.
Another object of this invention is to provide a handling string for a well test system in which pressure may be rapidly reduced to assure quick mechanical disconnect of the subsea test tree.
Another object is to provide a bleedoff tool for a test tree handling string, which is operable by predetermined torque and may be selectively operated to transmit greater than operating torque and will continue to transmit torque after operation.
Another object is to provide a bleedoff tool having a predetermined operating torque which is not changed by axial tension or compressive loads applied to the tool or high pressure therein.
Another object of this invention is to provide a bleedoff tool having a valve therein, which automatically closes during operation and prevents down flow through the tool.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 (A, B and C) is a schematic drawing showing the upper portion of a test string in a riser while testing a well.
FIG. 2 (A and B) is a half section elevation view drawing of the bleedoff tool of this invention.
FIG. 3 is a cross section view along line 3--3 of FIG. 2.
DESCRIPTION OF THE PREFERRED EMBODIMENT
FIG. 1, shows a subsea test tree 10 having a body portion 10a and a latch portion 10b. The test tree is made up in the upper portion of a pipe string, which is useful in the well testing and the system of this invention. The upper portion of the test string includes a hanger 11, a bleedoff tool 12 of this invention and a retainer valve 13. A lubricator valve 14 may also be included if desired or the VALVE of U.S. Pat. No. 4,522,370 to Noack and Rathie, which functions as both a lubricator valve and a retainer valve. The entire well test string is made up and run from a floating vessel through riser 15 and open blowout preventer 16 into the well, until hanger 11 lands on an internal shoulder 17 in the underwater well head. Routine well testing operations may now be conducted and the subsea test latch quickly disconnected from the body, if required, by first closing blowout preventer 16 on pipe below the test tree to prevent the test tree body from rotating and rotating the upper handling string portion of the pipe string and tools therein above the test tree.
If during testing operations, using the system of this invention, a quick disconnect of the test tree is required and the handling string and test tree latch portion cannot be released hydraulically nor rotated out of the body portion because of high pressure trapped between the closed retainer and subsea test tree valves in the handling string, the bleedoff tool of this invention may be operated to reduce the pressure.
The bleedoff tool 12 of this invention, in the preferred form is shown in FIG. 2, and has an appropriate thread 18 on upper body 19 for connection in the handling string. Connected in the upper body by threads 20 is a flapper prop 21, sealed to the upper body by resilient seal 22. The flapper prop is positioned in the body by jam nut 23. The upper body has a flow passage 19a to conduct trapped well fluid to a conduit (not shown) connected at threads 24 from shear open plug 25 which has flow passage 25a. The plug has been installed in sealing threads 26 cut through the wall between flow passage 19a and bore 19b in upper body 19. A plug 27 threaded into the body wall, closes the hole through which sealing threads 26 were cut. Resulient seal 28 seals plug 27 in the upper body. Connected to the upper body with threads 29 is a lower body 30. A resilient seal 31 seals the lower and upper bodies together. A second seal, metal ring 32 is compressed between the upper and lower bodies, sealing therebetween.
The lower body has a donwwardly extending lug 30a, a friction surface 30b and a number of shearable screws 33 are threadedly connected in the lower body wall and each protrudes into one of the slots 34a in lower mandrel 34. The lower mandrel has an appropriate thread 35 for connection into the well test string, a wall opening 34b, a lug 34c and is swivelably sealed in the lower body by resilient seal 36, which is positioned by retainer 37. The lower mandrel is connected to flapper mandrel 38 with threads 39. The flapper mandrel has a slot 38a, into which shear open plug 25 protrudes and a friction surface 38b. Retained in bore 38c on the upper end of the flapper mandrel by flapper housing 40 is a flapper seat 41. The flapper housing is connected to the mandrel by thread 42 and the flapper seat is sealed to the mandrel with resilient seal 43. There is a groove cut in the upper end of the flapper seat in which a resilient seal 44 is installed and a sealing surface 41a has been formed on the flapper seat. A pin 45 pivotally attaches a flapper valve 46, having a sealing surface 46a, to the flapper seat. A spring 47 is positioned around the pin, biasing the flapper valve toward closed position where sealing surface 46a sealingly engages sealing surface 41a and resilient seal 44, closing longitudinal flow passage 48 to downflow only.
FIG. 2 shows the flapper prop 21 positioned radially by plug 25 and pin 33 so the prop extension 21a prevents spring 47 from moving the flapper valve to closed position.
Connected and sealed to flapper mandrel 38 by threads 49 and resilient seal 50, respectively, is an upper mandrel 51. This upper mandrel is rotatably sealed in bore 19b with resilient seal 52 and rotatably sealed around flapper prop 21 with resilient seal 53. These seals and their backup rings are reatined on the upper mandrel with retainers 54 and 55. A sealed chamber C is formed in upper body 19 by seals 52 and 53. There are two holes (not shown) drilled from the outside of upper body 19 to allow chamber C to be filled with a liquid, preferably light oil. The holes and chamber are sealed by installing sealing plugs (not shown) in the holes.
Relative rotation between connected bodies 19, and 30, or body portion of the bleedoff tool, and connected mandrels 34, 38 and 51, or piston portion of the bleedoff tool, is prevented by shear open plug 25 protruding into slot 38a and shear screws 33 protruding into slot 34a.
The bleedoff tool, as shown in FIG. 2, is made up in the handling string above the subsea test tree and below the retainer valve and a conduit to the handling string above the retainer valve may be connected to the bleedoff tool body by thread 24 communicating flow passage 19a with the interior of the handling string or if no conduit is connected, flow passage 19a will communicate with the riser interior.
At any time during running in or pulling the test string from a well, the full weight of the test string suspended from the bleedoff tool will pull the tool mandrels (piston) out of the tool bodies, reducing liquid pressure in chamber C and increasing the normal length of the bleedoff tool until friction surface 38b contacts friction surface 30b.
When these friction surfaces contact, torque may be transmitted through the bleedoff tool. The friction surface roughness may be increased or friction surfaces grooved to create a clutching action and increase torque transmitted by the bleedoff tool when the friction surfaces contact.
When it is necessary to operate the bleedoff tool, almost the total weight of the test string is supported by hanger 11 on internal shoulder 17 and only the weight of the handling string above the bleedoff tool is supported by the bleedoff tool. This weight loads the bleedoff tool bodies, moving friction surface 30b from contact with friction surface 38b, increasing the pressure in liquid chamber C. When the friction surfaces are not contacting, the liquid chamber acts as a liquid bearing, supporting the weight of the handling string and providing low friction rotation of the bleedoff tool bodies around the tool piston portion.
The bleedoff tool has been provided with equal balancing areas, which prevent movement of the piston to further extend from or move into the bodies when trapped pressure is in passage 48. When the retainer valve above and the test tree valve below the bleedoff tool are closed, pressure is trapped therebetween in the handling string and bleedoff tool passage 48 and a tensile load is placed on the bleedoff tool moving friction surface 30b into moving contact with friction surface 38b, preventing relative rotation of the bodies and piston and operation of the bleedoff tool. The pressure trapped in passage 48 acts on the area sealed by seal 53 and through opening 34b on the area sealed by seal 52 tending to force the piston into the bodies. This pressure acts simultaneously on the area sealed by seal 36, (area of passage 48 plus annular area of mandrel 34 in seal 36) and tends to force the piston from the bodies. As these sealed areas are equal by design, the bleefoff tool is pressure balanced and high pressure in passage 48 will not move the piston into or further extend it out of the bodies.
When sufficient torque is placed on the handling string above the bleedoff tool to rotate the tool bodies around the tool piston, plug 25 and pins 33 and sheared, flapper prop 21 is rotated from under flapper 46, which is moved to closed position by spring 47 and pressure trapped between the closed retainer and test tree valves and in bleedoff tool passage 48 will flow through wall opening 34b, now open plug flow passage 25a, flow passage 19a and into the riser annulus exterior of the tool or a connected conduit and then into the handling string above the retainer valve. The cumulative torque shear values of pins 33 and plug 25 will determine the torque necessary to shear the plug and pins for rotation of the bleedoff tool bodies around the piston. The reduction in trapped pressure has reduced tensile loading on the test tree and friction between threaded disconnect members has been reduced greatly.
Continued rotation of the tool bodies relative to the piston after shear will contact body lug 30a with mandrel lug 34c, providing for transmission of handling string torque through the bleedoff tool to the test tree latch section to rotate the tree latch portion relative to the tree body and complete the emergency disconnect procedure.
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Disclosed is a safety system for well testing, utilizing a new and novel bleedoff tool in the subsea test tree handling string, which provides rapid pressure reduction in the handling string and assures mechanical disconnect of the subsea test tree if the test tree cannot be disconnected hydraulically. The bleedoff tool is operated and opened to bleed pressure from the handling string by applying a predetermined torque. This tool may be extended by pull to transmit higher than opening torque and will transmit torque after opening. The bleedoff tool contains an internal valve, which closes when the bleedoff tool is opened, and retains fluids in the handling string. The bleedoff tool operating torque values are not changed by high internal pressures or great axial tension or compressive loads on the tool.
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TECHNICAL FIELD
[0001] The present application generally relates to user authentication.
BACKGROUND ART
[0002] Mobile phones have become very common. Unfortunately, also the thefts of mobile phones have become more common. A thief may seek for use of the phone, to resell the phone for money and/or access to content within a phone. For the owner, the phones are personal items because of various sensitive private data they contain. Mobile phones are also being equipped with ever larger memories and often contain emails, short messages, calendar entries, phone books, call logs, photos and video clips taken by the phone, physical exercise diaries, shopping lists, and even online banking credentials.
SUMMARY
[0003] According to a first example aspect of the invention there is provided an apparatus comprising:
a memory; a processor configured to cause receiving of a user determination of a pool of images and; the processor being further configured to form from the pool of images a set of images for user authentication; the processor being further configured to divide the set of images into two mutually exclusive subsets: a key image subset comprising images referred to as key images and a decoy image subset comprising images referred to as decoy images; the processor being further configured to produce an assortment of decoy images and key images; the processor being further configured to cause displaying of the assortment of decoy and key images; the processor being further configured to cause receiving of user identification of images held as key images; and the processor being further configured to verify whether the identification of key images matched with the key images selected by the processor.
[0012] The proportion of key images to the decoy images in the assortment may match with the proportion of key images in the key image subset with the decoy images in the decoy image subset.
[0013] The displaying of the assortment may comprise displaying two or more different groups of images. Each group of images may comprise identical number of key images. Alternatively, the distribution of key images between the groups of images may be random.
[0014] The processor may be configured to form the groups of images such that one key image may only appear in one group of images in the assortment. Alternatively, a common key image may appear in more than one group of images.
[0015] The processor may be configured to form the groups of images such that one decoy image may only appear in one group of images in the assortment. Alternatively, a common decoy image may appear in more than one group of images.
[0016] The key images and the decoy images may be presented in the assortment such that each image in the set of images appears with identical likelihood. The identical likelihood of appearance may hinder frequency based detection of key images.
[0017] The processor may be configured to cause providing the user with feedback of selection of an image in the form of chosen from a group consisting of: tactile response, sound, change in shape, highlight of the selected image, and signal provided by background illumination.
[0018] The processor may be configured to cause displaying the key images to the user.
[0019] The forming of the set of images may comprise rejecting images that are not likely subjectively distinctive over other images. The forming of the set may further comprise determining images with entropy level below a predetermined minimum level. The forming of the set may further or alternatively comprise determining images that resemble other images with a correlation that is higher than a predetermined maximum level.
[0020] The apparatus may be selected from a group consisting of: mobile communication device; personal digital assistant; music player; navigation apparatus; digital camera; camcorder; laptop computer; access control apparatus; and laundry machine.
[0021] According to a second example aspect of the invention there is provided a method comprising:
receiving of a user determination of a pool of images and; forming from the pool of images a set of images for user authentication; dividing the set of images into two mutually exclusive subsets: a key image subset comprising images referred to as key images and a decoy image subset comprising images referred to as decoy images; producing an assortment of decoy images and key images; causing displaying of the assortment of decoy and key images; causing receiving of user identification of images held as key images; and verifying whether the identification of key images matched with the key images selected by the processor.
[0029] The proportion of key images to the decoy images in the assortment may match with the proportion of key images in the key image subset with the decoy images in the decoy image subset.
[0030] The displaying of the assortment may comprise displaying two or more different groups of images. Each group of images may comprise identical number of key images. Alternatively, the distribution of key images between the groups of images may be random.
[0031] The method may comprise forming the groups of images such that one key image may only appear in one group of images in the assortment. Alternatively, a common key image may appear in more than one group of images.
[0032] The method may comprise forming the groups of images such that one decoy image may only appear in one group of images in the assortment. Alternatively, a common decoy image may appear in more than one group of images.
[0033] The key images and the decoy images may be presented in the assortment such that each image in the set of images appears with identical likelihood. The identical likelihood of appearance may hinder frequency based detection of key images.
[0034] The method may further comprise causing providing the user with feedback of selection of an image in the form of chosen from a group consisting of: tactile response, sound, change in shape, highlight of the selected image, and signal provided by background illumination.
[0035] The forming of the set of images may comprise rejecting images that are not likely subjectively distinctive over other images. The forming of the set may further comprise determining images with entropy level below a predetermined minimum level. The forming of the set may further or alternatively comprise determining images that resemble other images with a correlation that is higher than a predetermined maximum level.
[0036] The method may further comprise causing displaying of the key images to the user.
[0037] The method may be performed in an apparatus selected from a group consisting of: mobile communication device; personal digital assistant; music player; navigation apparatus; digital camera; camcorder; laptop computer; access control apparatus; and laundry machine.
[0038] According to a third example aspect of the invention there is provided a computer executable program comprising computer executable program code, which when executed by a computer, causes the computer to cause an apparatus to perform any method according the second example aspect.
[0039] The computer program may be stored in a memory medium. The memory medium may comprise a digital data storage such as a data disc or diskette, optical storage, magnetic storage, holographic storage, opto-magnetic storage, phase-change memory, resistive random access memory, magnetic random access memory, solid-electrolyte memory, ferroelectric random access memory, organic memory or polymer memory. The memory medium may be formed into a device without other substantial functions than storing memory or it may be formed as part of a device with other functions, including but not limited to a memory of a computer, a chip set, and a sub assembly of an electronic device.
[0040] Different non-binding example aspects and embodiments of the present invention have been illustrated in the foregoing. The above embodiments are used merely to explain selected aspects or steps that may be utilized in implementations of the present invention. Some embodiments may be presented only with reference to certain example aspects of the invention. It should be appreciated that corresponding embodiments may apply to other example aspects as well.
BRIEF DESCRIPTION OF THE DRAWINGS
[0041] The invention will be described, by way of example only, with reference to the accompanying drawings, in which:
[0042] FIG. 1 shows a schematic drawing of a system according to a first example embodiment of the invention;
[0043] FIG. 2 shows a block diagram of an apparatus according to a second example embodiment of the invention;
[0044] FIG. 3 shows an assortment of authentication images according to a seventh example embodiment of the invention;
[0045] FIG. 4 shows an assortment of authentication images according to an eleventh example embodiment of the invention; and
[0046] FIG. 5 shows a flow chart illustrating a process according to a twelfth example embodiment of the invention.
DETAILED DESCRIPTION
[0047] In the following description, like numbers denote like elements.
[0048] FIG. 1 shows a schematic drawing of a system 100 according to a first example embodiment of the invention. The system 100 comprises a user 110 , an apparatus 120 , and an external image repository 130 such as a home computer or network based backup server storing images possessed by the user 110 . The images may be, for instance, photograph images taken by the user. User access to the apparatus 120 is controlled by the apparatus 120 in accordance with an example embodiment of the invention by receiving of a user determination of a pool of images, forming from the pool of images a set of images for user authentication, dividing the set of images into two mutually exclusive subsets: a key image subset comprising images referred to as key images and a decoy image subset comprising images referred to as decoy images; displaying the key images to the user 110 , producing an assortment of decoy images and key images, displaying the assortment of decoy and key images, receiving identification of images held as key images; and verifying whether the identification of key images matched with the key images selected by the processor.
[0049] FIG. 2 shows a block diagram of an apparatus 120 according to a second example embodiment of the invention that is also applicable with the first example embodiment. FIG. 2 also depicts blocks that are not necessarily present in some other embodiments of the invention. Hence, alike the whole description, the description of FIG. 2 is also to be understood as description of some example structures that may be omitted, replaced by other structures or supplemented by structures that are not expressly described in this context. The apparatus 120 comprises a main processor 210 in general control of different functions of the apparatus 120 . Moreover, the apparatus 120 comprises a memory 220 with a work memory 222 and a non-volatile memory 224 that may store, among others, software or operating instructions 224 , graphical authentication data 230 that comprises key images 232 and decoy images 234 , and user media gallery 240 . For communications, the apparatus 120 comprises a communication unit 250 and an antenna 260 . A battery 270 may be provided for mobile operation. For use as a viewfinder and/or for displaying instructions and/or presenting different prompts for a user 110 , the apparatus 110 may comprise a display 280 .
[0050] In a third example embodiment of the invention applicable with the first and second example embodiments, the main processor 210 comprises, for instance, one or more master control processor, central processing unit, and/or digital signal processor. Moreover, in a fourth example embodiment of the invention applicable with any of the first to third example embodiments, the main processor 210 and the camera processor are integrally formed while presented as logically separate blocks in FIG. 2 .
[0051] In a fifth example embodiment of the invention applicable with any of the first to fourth example embodiments, the memory is partly or entirely secured. For instance, the memory may comprise a trusted platform module (TPM) configured to secure secrecy of data.
[0052] The work memory 222 may comprise, for instance, random access memory, video random access memory or dynamic random access memory.
[0053] The non-volatile memory 224 may comprise flash-ram, electronically erasable read only memory, hard disk, hard disk array, optical storage, memory stick, memory card and/or magnetic memory.
[0054] The software 224 may comprise operating system, device drivers, program libraries, program interpreters, interpreting software platforms, binary applications, scripts, applets, macros and/or applications.
[0055] In a sixth example embodiment of the invention applicable with any of the first to fifth example embodiments, the apparatus 120 is selected from a group consisting of: mobile communication device; personal digital assistant; music player; navigation apparatus; digital camera; camcorder; laptop computer; access control apparatus; and laundry machine.
[0056] FIG. 3 shows an assortment of authentication images according to a seventh example embodiment of the invention applicable with any of the first to sixth example embodiments. It is appreciated that the assortment typically comprises a number of different groups of authentication images, but it suffices to show in FIG. 3 only one such group to describe this example embodiment.
[0057] FIG. 3 shows a grid 300 of authentication images according to an eighth example embodiment of the invention applicable with any of the first to seventh example embodiment. The grid generally comprises N rows and M columns, where N ranges between 2 and 10 and M ranges between 2 and 10. Grids dimensioned as 3×3 or 3×4 may directly mapped to normal keypad of a mobile phone, but of course larger grids accommodate more authentication images. The grid 300 of FIG. 3 is a 3×3 grid with rows R 1 to R 3 and columns C 1 to C 3 . According to a ninth example embodiment of the invention applicable with any of the first to eighth example embodiment, the number of rows and columns is so determined that the individual images on the display of the apparatus 120 are distinguishable from one another by the user 110 .
[0058] Some of the authentication images shown in the grid 300 are key images while the others are decoy images. The user 110 knows by heart the key images. According to a tenth example embodiment of the invention applicable with any of the first to ninth example embodiment, to authenticate herself to the apparatus 120 , the user 110 identifies to the apparatus 120 the images that she considers as key images.
[0059] Let us assume that in grid 300 , the image in the center is a key image. Thus, the user 110 points out that image R 2 C 2 to the apparatus 120 (e.g. by touching the image if a touch screen is used or by tapping a corresponding key on the keypad). After the user 110 has pointed out the key image(s), the user 110 confirms that the key image identification for shown grid is complete and the apparatus 120 can proceed to show further grids or to check whether given identification(s) and the key images match. Alternatively to waiting for a user 110 to enter a confirmation when the entry of key image identification is complete, the apparatus 120 may be configured to input a number of identifications corresponding to the number of key images and automatically proceed when all identifications have been provided by the user 110 .
[0060] FIG. 4 shows an assortment of authentication images according to an eleventh example embodiment of the invention applicable with any of the first to tenth example embodiment, FIG. 4 differs from FIG. 3 in that in FIG. 4 , same image may appear in more than one cell of the grid 300 . In this example, it is assumed that two cells (C 1 R 1 and C 2 R 2 ) of the grid 300 share a common key image and two cells (C 3 R 1 and C 3 R 3 ) share a common decoy image. Of course, the doubled image need not be a key image. FIG. 4 merely illustrates an example in which each authentication image is randomly selected without regard to images used elsewhere in the assortment of authentication images.
[0061] In the example embodiment illustrated by FIG. 3 , each authentication image appears only once so that even if the assortment is distributed on more than one different page or group of images, no two groups shares a common image, whether key image or decoy image.
[0062] In the eleventh example embodiment illustrated by FIG. 4 , instead, a common image may appear twice in one group and/or a common image may appear in two or more groups of images. Operation according to some example embodiments of the invention will next be described in connection with FIG. 5 .
[0063] FIG. 5 shows a flow chart according to a twelfth example embodiment of the invention applicable with any of the first to eleventh example embodiment illustrating a process according to an example embodiment of the invention. The process starts from block 500 in which the apparatus 120 is running and an authentication is being taken to use. In step 502 , a pool of images is defined by the user and authentication images are determined from the pool. The authentication images may also be referred to as a set of images for user authentication. That the user defines the pool of images may be beneficial for recognizing the authentication images as the images may then be associated with people and places that are familiar to the user. For privacy reasons, the user may, for instance, only select images that she is happy to let others see.
[0064] According to a thirteenth example embodiment of the invention applicable with any of the first to twelfth example embodiment, the process involves computationally rejecting images that are not likely subjectively distinctive over other images, 504 . This rejecting may be based on determining images that resemble other images with a correlation that is higher than a predetermined maximum level. In an example embodiment of the invention, Daly's Visible Differences (VDP) predictor is used to estimate whether an image is likely too similar with another image.
[0065] According to a fourteenth example embodiment of the invention applicable with any of the first to thirteenth example embodiment, the determining of the authentication images may further comprise rejecting images with entropy level below a predetermined minimum level, 506 . In one example embodiment of the invention, canny edge detection is used to identify the proportion of each image taken up with edges. If this measure falls below a given threshold, the entropy is deemed to be insufficient for the image in question likely possessing sufficient subjective distinctiveness.
[0066] According to a fifteenth example embodiment of the invention applicable with any of the first to fourteenth example embodiment, rejected images are replaced by other images of the image pool, after testing such replacement images in a fashion similar to that described in connection with steps 502 to 506 . The process of selecting authentication images may be substantially automatic so as to avoid user bias in selecting key images. According to a sixteenth example embodiment of the invention applicable with any of the first to fifteenth example embodiment, after the authentication images are selected, a key image subset is formed and the key images are taught to the user, 508 . The number of decoy images may be at least 8 times the number of key images, e.g. 8, 9 or 12, in order to counter intersection attacks. According to a seventeenth example embodiment of the invention applicable with any of the first to sixteenth example embodiment, the teaching of the key images comprises showing the key images to the user 110 and allowing the user 110 to rehearse selecting the key images from among remaining authentication images (wherein the remaining images form a decoy image set). The teaching may also be staged so that first a part or all of the key images are taught to the user 110 and the user 110 is also allowed to later learn the key images to refresh and maintain knowledge of the key images.
[0067] The stage in which the key images are shown to the user 110 is sensitive in terms of security. Normal users 110 would also understand the need to perform this step in privacy such that the key images are not exposed to a shoulder attack at this stage, even if under normal use the apparatus 120 could also be seen by friends or colleagues of the user 110 and thus the apparatus 120 might become exposed to a shoulder attack, i.e. potentially malicious people seeing some authentication images over the shoulder of the user 110 . Normal authentications are to some extent protected against shoulder attacks by dimensioning the total number of authentication images and the number of authentication images in the assortment such that an attacker would not gain sufficient likelihood of success even if she were able to identify all the key images.
[0068] Steps 500 to 508 in FIG. 5 prepare the apparatus 120 to a state in which the apparatus 120 is ready to authenticate the user 110 with the authentication images. According to an eighteenth example embodiment of the invention applicable with any of the first to seventeenth example embodiment, the apparatus 120 then, at some point of time, detects 510 a need to authenticate the user 110 . In response, the apparatus 120 randomly selects decoy images and key images to an assortment for use to authenticate the user, 512 . The selecting may apply any of the following principles:
one authentication image appears only once in the assortment; any image in the assortment is selected independently of other images so that images may appear more than once; the proportion of key image instances in the assortment matches with the proportion of key images in the authentication images such that the frequency of appearance of particular image would not indicate whether that image would more likely be a key image or decoy image.
[0072] According to a nineteenth example embodiment of the invention applicable with any of the first to eighteenth example embodiment, the apparatus 120 shows to the user 110 the assortment in one or more groups of images, 514 . The user 110 then identifies to the apparatus 120 the images which she has found as key images, 516 . According to a twentieth example embodiment of the invention applicable with any of the first to nineteenth example embodiment, the user 110 is provided with feedback to assure the user 110 of successful selection. The feedback may be in the form of chosen from a group consisting of: tactile response, sound, change in shape, highlight of the selected image, and signal provided by background illumination.
[0073] In a twenty-first example embodiment of the invention applicable with any of the first to twentieth example embodiment, the assortment is shown by the apparatus 120 in groups of one image i.e. image by image. In this embodiment, the user is informed of an associated identifier for each image when shown to the user. The user then provides the identifiers to the apparatus 120 . The identifiers may be provided while the images are being identified. In a twenty-second example embodiment applicable with any of the first to twenty-first example embodiment, the apparatus 120 only accepts the identifiers after presenting all of the authentication images of the assortment so as to prevent a shoulder attacker from determining the key images from the timing of identifier entry.
[0074] The showing of the images one by one takes place in a twenty-third example embodiment applicable with any of the first to eighteenth or twentieth to twenty-second example embodiment by displaying the images as a moving chain or as a drum wherein approaching images are shown as smaller images and presently shown image is displayed as a larger image together with the identifier.
[0075] According to a twenty-fourth example embodiment of the invention applicable with any of the first to twenty-third example embodiment, the identifier is formed as a pair of key legends so as to allow a user to memorize the identifiers for the time when the assortment is being displayed and then enter the identifiers by using keys according to the key legends. For instance, in ITU-T keypad of mobile phones, there are typically printed numbers 0 to 9 and subsets of alphabets “abc”, “der, “ghi”, jkl”, “mno”, “pqrs”, “tuv”, “wxyz”. The first alphabet of each subset may be used as a part of a legend pair. For instance, one legend may be expressed as “m2” indicative of user having to first apply key 6 (for “m”) and then key 2.
[0076] According to a twenty-fifth example embodiment of the invention applicable with any of the first to twenty-fourth example embodiment, the apparatus 120 then checks whether the user 110 identified key images match with the key images in the assortment, 518 . If yes, the user 110 is authenticated 520 and normal operation follows 522 . If no, the authentication failure is determined 524 , according to a twenty-sixth example embodiment of the invention applicable with any of the first to twenty-fifth example embodiment, a report of the authentication error is produced 526 to the user 110 and the apparatus 120 checks 528 whether a maximum number of attempts has been made already. If there are no more attempts left or if there is no limit for the number of attempts but simply a delay is incurred to mitigate brute force attacks, the process resumes to step 512 . Otherwise, secondary authentication may be started 530 to verify whether the user 110 has authentication to use the apparatus 120 or whether the apparatus 120 should be finally locked 532 . However, if the secondary authentication succeeds, the process jumps to step 522 for normal operation. At this stage, according to a twenty-seventh example embodiment of the invention applicable with any of the first to twenty-sixth example embodiment, the user is provided with an option to study the key images again and/or to cause regeneration of the authentication keys starting from step 502 .
[0077] According to a twenty-eighth example embodiment of the invention applicable with any of the first to twenty-seventh example embodiment, the apparatus changes the appearance of the images identified by the user 110 when the user has provided the respective identification. The change of appearance may be temporary and/or persistent. The change may involve, for instance, short flash of brightness of the image, concealing of the identified image, replacement of the identified image with another image, or changing the identified image more dim or blurred.
[0078] In a twenty-ninth example embodiment of the invention applicable with any of the first to twenty-eighth example embodiment, correction of an erroneous identification is provided by interpreting subsequent identification of a given image as reversal of preceding identification of that image.
[0079] In this document, identification of an image has been used as a shortcut for referring to the identification of an image instance in a particular cell of the grid. Namely, it is understood that one image may reside in more than one cell. However, even in that case, some example embodiments automatically select each instance of an image when one cell containing that image has been identified.
[0080] In a thirtieth example embodiment of the invention applicable with any of the first to twenty-ninth example embodiment, the key images are assigned a particular order. In this case, when more than one key image is displayed simultaneously in an assortment, the user shall identify the key images according to the defined order in order to authenticate herself. The order of the key images may be taught to the user by teaching the key images in that order so that the user 110 will learn the order of the key images on learning the key images.
[0081] The foregoing description has provided by way of non-limiting examples of particular implementations and embodiments of the invention a full and informative description of the best mode presently contemplated by the inventors for carrying out the invention. It is however clear to a person skilled in the art that the invention is not restricted to details of the embodiments presented above, but that it can be implemented in other embodiments using equivalent means or in different combinations of embodiments without deviating from the characteristics of the invention.
[0082] Furthermore, some of the features of the above-disclosed embodiments of this invention may be used to advantage without the corresponding use of other features. As such, the foregoing description shall be considered as merely illustrative of the principles of the present invention, and not in limitation thereof. Hence, the scope of the invention is only restricted by the appended patent claims.
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An apparatus lets a user to determine a pool of images and then forms from the pool of images a set of images for user authentication and divides the set of images into two mutually exclusive subsets: a key image subset comprising images referred to as key images and a decoy image subset comprising images referred to as decoy images. The apparatus displays the key images to the user to teach the key images to the user. Then, to authenticate the user, the apparatus produces an assortment of decoy images and key images, and displays the assortment to the user. The apparatus receives from the user identification of images held as key images and verifies whether the identification of key images matched with the key images selected by the processor.
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CROSS-REFERENCE TO RELATED APPLICATIONS
The present application is the US national stage under 35 U.S.C. §371 of International Application No. PCT/FR2008/051167 which claims the priority of French application 0756333 filed on Jul. 9, 2007, the content of which (description, claims and drawings) is incorporated herein by reference.
BACKGROUND
The invention relates to a method for starting the internal combustion engine of an automobile. This method is particularly useful for cold start operations. In general, the goal of the invention is to reduce at the origin the polluting emissions of gasoline engines.
The quality of fuel used for vehicles varies greatly, especially as a function of the geographical zone where the vehicles operate. A particularly variable physical property of fuel is its vaporizing capacity, in other words its varying volatility. This capacity is well known in Anglo-Saxon literature under the acronym RVP (Raid Vapor Pressure). This acronym will be used in the following description of the invention. Fuels that vaporize easily are called HRVP (High RVP) and fuels that do not vaporize easily are called LRVP (Low RVP).
In order to start correctly, a gasoline engine requires a mixture of air and gasoline close to the stoichiometric mixture. This assumes proper control of the quantity of fuel under gaseous form. According to the volatility of the fuel, the quantity of fuel under gaseous form that participates in the combustion during cold start and when the engine is cranked can vary enormously for the same quantity of injected fuel.
In order to ensure a sufficient quantity of fuel under gaseous form for proper combustion during start and cranking of the engine, calibrations are made with a fuel that is representative of a fuel with relatively low volatility (LRVP). Then, tests are performed to ensure that when a more volatile fuel is used, type HRVP, the injected quantities are not excessive and there is no risk that excess gasoline in vapor form will hinder the combustion, due to the mixture becoming non-inflammable.
Therefore, the adjustment is the same regardless of the fuel. Consequently, when a relatively more volatile fuel is used, the quantity of fuel in vapor form is excessive during start and cranking of the engine. This excess does not participate in the combustion and is found in the exhaust of the engine in the form of unburned hydrocarbons (HC). This has a direct impact on the polluting emissions of the engine because even if the vehicle is equipped with a catalyst, the catalyst is not cold primed and the unburned hydrocarbons escape to the atmosphere.
During start in extreme cold, when the ambient temperature is below −15° C., the excess fuel in vapor form also creates black smoke at the exhaust.
BRIEF SUMMARY
Attempts were made to resolve this problem by adjusting the quantity of fuel injected in the engine cylinder during the start phase as a function of the vaporizing capacity of the fuel. Since it is difficult to measure this capacity directly in a vehicle, the vaporizing capacity of the fuel was estimated as a function of a speed gradient of the engine occurring after the first combustion in an engine cylinder. This gradient can be calibrated as a function of different types of fuel having different vaporizing capacities.
This method improves the adjustment of the fuel quantity injected in the engine during a start operation occurring after estimation of the vaporizing capacity of the fuel. Nevertheless, the obtained result is not very reliable in the light of other parameters that influence the performed measurement.
The goal of the invention is to improve the robustness of start performance, in particular cold start, by proposing to vary the calibration of a reference gradient as a function of the evolution of the internal friction torque of the engine.
To this end, the goal of the invention is a method for starting an internal combustion engine associated with means for adjusting, during the start operation of the engine, the quantity of injected fuel as a function of the estimated volatility of the fuel based on the comparison between the engine speed gradient measured during a preceding start operation and an reference gradient corresponding with a predefined fuel, characterized by a correction stage of the reference gradient as a function of the evolution of the friction torque of the engine.
Advantageously, the engine is associated with control means supervising its operation that use the evolution of the friction torque. In this way, the invention can be implemented without the need to add a supplementary sensor in the vehicle for measuring the evolution of the friction torque, because this information is already available at the engine control level.
Conventionally, the speed gradients can be determined starting from a first combustion occurring during the start operation.
Advantageously, the speed gradient correction is proportional to the ratio between the evolution of the friction torque and the inertia of the engine.
The speed gradients can be determined as the difference in engine speed between two successive combustions and the correction of the speed gradient proportional to the time separating the two successive combustions.
Advantageously, the reference gradient is a function of the engine temperature and the number of combustions that have taken place since the first combustion.
Several reference gradients can be defined for distinct values of the fuel vaporizing capacity. The quantity of fuel to be injected can be defined in linear or discrete manner as a function of the measured gradient value with respect to the reference values.
During the start operation, the gradient measured during one or more previous first start operations can be taken into account. For instance, the average can be made of several starts or an aberrant gradient measurement can be eliminated.
The present invention applies in particular to so-called “gasoline” engines, with spark ignition, and more in particular to engines likely to be supplied with different types of fuels, especially “gasoline” or alcohol based fuels (pure or in mixture with gasoline), in particular, FLEXFUEL type engines.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention will be better understood and other advantages will come to light in the detailed description of an implementation mode, given as an example, illustrated by the attached drawing in which:
FIG. 1 shows an example of the evolution of engine speed during the start operation;
FIG. 2 shows an example of the measured engine speed evolution relative to a reference evolution;
FIG. 3 shows schematically a correction made to the reference speed evolution as a function of the variation of the internal friction torque of the engine.
For clarity reasons, the same elements have the same references in the different figures.
DETAILED DESCRIPTION
FIG. 1 shows in chronogram form an example of engine speed evolution during a start operation. The abscissa is graduated in seconds and PMH (upper dead point). This second graduation corresponds with points in time where combustions are likely to occur. These points are indicated by vertical arrows and continuing dotted lines. On the ordinate, the rotational speed of the engine is expressed in revolutions per minute.
At the time origin, 0 on the time axis, a start operation of the engine is initiated. Up to the fourth upper dead point, the vehicle starter cranks the engine at a speed between 300 and 400 revolutions per minute. At the fourth upper dead point, a first combustion 100 occurs in one engine cylinder. This first combustion is indicated in FIG. 1 by a star with five points. Beyond the fourth upper dead point, the engine speed increases until it reaches approximately 1400 revolutions per minute and then it decreases until it stabilizes at approximately 1000 revolutions per minute after the twentieth upper dead point. In practice, the engine speed is measured in each upper dead point, which is represented by a stair step curve 101 connecting the engine speed values in each upper dead point. Another, smoothened curve 102 connects directly the engine speed values measured in the different upper dead points.
FIG. 2 shows, with the same references as FIG. 1 , a so-called reference evolution 103 , similar to curve 102 . Curve 103 is the ideal evolution for the engine. If a start operation follows evolution 103 , the engine ejects the minimum possible amount of pollutants. Therefore, the fuel quantity injected in the engine cylinders during a start operation must be regulated so that it approaches as much as possible evolution 103 .
On FIG. 2 , another curve 104 represents the actual measured curve of a start operation. The first combustion 105 of evolution 104 occurs after the first combustion 106 of evolution 103 . The maximum speed 107 reached by evolution 104 is around 1100 revolutions per minute. Speed 107 is lower than the maximum speed 108 reached by evolution 103 . In addition, during the speed increase, after the first combustion, the gradient of evolution 104 , or slope of evolution 104 , is lower than the gradient of evolution 103 .
It is known that this gradient is a function of the RVP of the used fuel. Furthermore, it was observed that this gradient depended also of the friction torque of the engine. By engine friction torque is understood all the resistance elements opposing the rotation of the engine without generating a speed. The friction torque is generated specifically inside the engine and through the transmission chain up to the clutch of the vehicle. These resistance elements are expressed in torque and are a function of different parameters such as engine speed.
The engine speed is easily determined by measurement and is taken into account in the reference evolution 103 . The initial friction torque of the engine, in other words the existing friction of a new engine, is also taken into account in the reference evolution 103 . On the other hand the friction torque is likely to evolve during the life of the engine. For instance, the friction torque evolves with engine wear and when the lubrication oil used in the engine is changed.
Consequently, for the same fuel (identical RVP), and while maintaining identical quantities of injected fuel, different engine speed evolutions can be measured during start operations. By maintaining a constant reference evolution, there is a risk of evolving the injected fuel quantities when the friction torque varies. This would result in the operation of the engine moving away from the stoichiometric ratio and the generation of pollution.
According to the invention, in order to improve the operation of the engine the reference evolution is corrected as a function of the variation of the engine friction torque.
Furthermore, modern vehicles are equipped with engine control means. These means implement, for instance, a torque feedback structure for the CME torque available at the crankshaft as a function of a command issued when the accelerator pedal of the vehicle is depressed by the driver of the vehicle. To this CME torque must be added the friction torque CMF of the engine and the distribution chain in order to obtain the CMI torque that must be supplied by the internal combustion of the engine.
The engine control means measure the evolution of the friction torque ΔCMF over the life of the engine. According to the invention, the information regarding the evolution of the friction torque ΔCMF is used for correcting the reference gradient.
In general, the torque is equal to the product of inertia and speed gradient. Applied to the idling engine, without driving the wheels, we have:
CMF = J mot · ⅆ ω mot ⅆ t ( 1 ) or : ⅆ ω mot ⅆ t = CMF J mot ( 2 )
equation in which J mot represents the inertia of the engine, ω mot represents the rotational speed of the engine and t the time.
Introducing the evolution of the friction torque ΔCMF, equation (2) becomes:
ⅆ ω mot _ ref _ corrected ⅆ t = - Δ CMF J mot + ⅆ ω mot _ ref ⅆ t ( 3 )
equation in which
ⅆ ω mot - ref ⅆ t
represents the reference gradient of the rotational speed of the engine and
ⅆ ω mot _ ref _ corrected ⅆ t
represents the corrected reference gradient of the rotational speed of the engine.
Equation (3) can be transformed in an equation with easy to measure engine parameters:
(
N
n
-
N
n
-
1
)
ref
_
corrected
=
-
Δ
CMF
J
mot
*
30
π
*
T
PMH
+
(
N
n
-
N
n
-
1
)
ref
(
4
)
In equation (4), the rotational speeds of the engine Ni are expressed in revolutions per minute at moments i in which combustions are likely to occur. T PMH expressed in seconds represents the time interval separating two previously described moments.
The factor
30 π
ensures the homogeneity of the equation by converting radians per second in revolutions per minute.
FIG. 3 represents equation (4) in schematic form. A box 110 represents a table defining the reference gradient (N n −N n-1 ) ref . The value of the reference gradient is a function of the engine temperature, for instance the temperature of the cooling liquid, designated as input T water of box 110 , and of the number of PMH's, designated Nb_PMH, elapsed since the first combustion.
The correction function
Δ CMF J mot * 30 π * T PMH
of the engine friction torque evolution is represented by box 111 . The application of the correction to the reference gradient in order to obtain the corrected speed gradient is represented by box 112 .
The measured gradient is then compared with the corrected speed gradient. The result of this comparison is a function of the RVP of the fuel used by the engine. Therefore, the quantity of fuel injected during the next start can be modified so that the measured gradient is as close as possible to the corrected gradient.
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The invention relates to a method for starting an internal combustion engine associated with means for adapting, during an engine start operation, an amount of fuel injected based on an estimation of the volatility (PVR) of the fuel based on the comparison between a gradient of the engine speed measured upon a preceding start operation and a reference gradient ( 110 ) corresponding to a predetermined fuel, characterized by the step ( 111 ) of correcting the reference gradient based on a change (ΔCMF) in the engine friction torque.
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CROSS-REFERENCE TO RELATED APPLICATION
This application claims priority of Korea patent Application No. 99-62083, filed on Dec. 24, 1999.
BACKGROUND OF THE INVENTION
(a) Field of the Invention
The present invention relates to a control method for a diesel engine, and more particularly, to a control method for a diesel engine in which a vehicle speed limit is increased after determining that the vehicle is travelling on a downgrade, thereby enabling the momentum of the downgrade to be used to propel the vehicle.
(b) Description of the Related Art
The main structural elements of a diesel engine for converting heat energy into mechanical energy are not significantly different from those of the gasoline engine. However, the processes of fuel supply and fuel combustion are performed differently in the diesel and gasoline engines. In particular, only air is supplied during the intake stroke, and after compression to a high compression ratio of 15-22:1, resulting in an increase in temperature to roughly 500-600° C., fuel injected into the combustion chamber is ignited as a result of the high temperature generated therein (i.e., the fuel undergoes self-combustion).
Accordingly, a fuel injection system is needed in the diesel engine. Also, diesel fuel, which easily self-combusts, must be used. The fuel injection system of the diesel engine includes a fuel tank, a fuel pipe, a fuel supply pump, a fuel filter, an injection pump, a high pressure pipe, and an injection nozzle. Fuel is supplied to the injection nozzle by first passing through these elements in the order listed.
The injection pump is driven by an engine crankshaft to pressurize fuel to a high pressure and inject the fuel into the combustion chamber through the injection nozzle. The fuel is injected into the combustion chamber at a predetermined pressure and at the appropriate time. Together with the shape of the combustion chamber, injection timing, injection period, fuel injection amount, injection state (i.e., spray travel distance or penetration force), distribution state, degree of atomization, etc., these are all important factors in determining the combustion state. A governor and timer are provided in the injection pump to enable the variation of fuel injection amounts and fuel injection timing.
The fuel injection amount and fuel injection timing can be mechanically controlled or electronically controlled using a microcomputer. These parameters are now, for the most part, controlled electronically. Also, much research is being conducted to enable more precise control of fuel injection amount and timing.
Diesel engines are more often found in large vehicles such as buses and trucks. As a safety precaution, a speed limit device is typically provided to prevent the vehicle from travelling over a predetermined speed of, for example, a legal speed limit. That is, when the predetermined speed is exceeded, operation of the accelerator pedal has no effect in that the fuel supply to the engine is cut-off.
In both the vehicle equipped with the mechanical and electronic control of the fuel injection amount and fuel injection timing, it is possible to disengage such control. In the case of the diesel engine that is electronically controlled, it is possible to remove or disconnect the vehicle speed sensor, thereby disenabling fuel injection amount and timing control. However, when the vehicle speed sensor is removed or disconnected, various other electronic controls are also disabled, such as the automatic cruise control.
SUMMARY OF THE INVENTION
The present invention has been made in an effort to solve the above problems.
It is an object of the present invention to provide a control method for a diesel engine in which the vehicle speed limit is automatically increased to a specific level to enable an increase in speed by the operation of the accelerator pedal.
To achieve the above object, the present invention provides a method for controlling a diesel engine comprising the steps of determining if a vehicle is travelling on a downgrade; outputting a predetermined fuel supply cut-off signal when the vehicle is travelling on a downgrade; determining an error between a vehicle speed limit and a present vehicle speed; setting an aiming speed as a first predetermined value; determining an aiming error; determining if the aiming error is greater than 0; setting an enable vehicle speed as a second predetermined value when the aiming error is greater than 0; setting the enable vehicle speed to 0 when the aiming error is less than 0; subtracting the error between the vehicle speed limit and the present vehicle speed from the enable vehicle speed to thereby derive an enable error; determining if the enable error is greater than 0; setting an offset vehicle speed Off_set as a third predetermined value when the enable error is greater than 0; setting the offset vehicle speed to 0 when the enable error is not greater than 0; determining if an accelerator pedal position has reached or is greater than a fourth predetermined value; adding the offset vehicle speed to the vehicle speed limit to thereby obtain a new vehicle speed limit when the accelerator position has reached the fourth predetermined value; determining if the present vehicle speed is less than the new vehicle speed limit; outputting a fuel supply control signal when the present vehicle speed is less than the new vehicle speed limit; and outputting a fuel supply cut-off control signal when the present vehicle speed is greater than the new vehicle speed limit.
According to a feature of the present invention, it is determined if the vehicle is travelling on a downgrade when the vehicle speed exceeds the vehicle speed limit for over a predetermined duration of time.
According to another feature of the present invention, the first and second predetermined values are stored in a pre-installed program and are respectively 6 kph and 4 kph.
According to still another feature of the present invention, when the enable error is greater than 0, it is determined that the vehicle has reached the end of the downgrade.
According to still yet another feature of the present invention, the third predetermined value is stored in a pre-installed program and is 20 kph.
According to still yet another feature of the present invention, the fourth predetermined value is 50%.
BRIEF DESCRIPTION OF THE DRAWINGS
The accompanying drawings, which are incorporated in and constitute a part of the specification, illustrate an embodiment of the invention, and, together with the description, serve to explain the principles of the invention:
FIG. 1 is a block diagram of a diesel engine control system to which the present invention is applied;
FIG. 2 is a flow chart of a control method for a diesel engine according to a preferred embodiment of the present invention; and
FIG. 3 shows various graphs of vehicle speed and fuel supply in relation to time as a vehicle travels on a downgrade.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Preferred embodiments of the present invention will now be described in detail with reference to the accompanying drawings.
FIG. 1 shows a block diagram of a diesel engine control system to which the present invention is applied.
The diesel engine control system comprises a detection unit 10 including a vehicle speed sensor 11 for detecting vehicle speed and an accelerator pedal position sensor 12 for detecting a position of an accelerator pedal; a control unit 20 for controlling fuel supply; and a fuel injector 30 operated according to signals output by the control unit 20 to supply fuel and cut off the supply of the same.
The control unit 20 receives signals output by the detection unit 10 to determine vehicle speed and accelerator pedal position, and compares the vehicle speed with a predetermined vehicle speed limit. When the vehicle speed exceeds the vehicle speed limit, the control unit 20 outputs a fuel supply cut-off signal. Using the detected vehicle speed, the control unit 20 also determines if the vehicle is travelling on a downgrade, as well as when an end of the downgrade has been reached. When the vehicle is travelling on a downgrade, an offset vehicle speed is established and it is determined if the position of the accelerator pedal has reached or exceeded a third predetermined value. When the position of the accelerator pedal is at or exceeds the third predetermined value, the offset vehicle speed is added to the predetermined vehicle speed limit to generate a new vehicle speed limit. Next, the control unit 20 determines if the detected vehicle speed is less than the new vehicle speed limit. When the detected vehicle speed is less than the new vehicle speed limit, the control unit 20 outputs a fuel supply control signal, and when the detected vehicle speed is greater than the new vehicle speed limit, the control unit 20 outputs a fuel supply cut-off control signal.
FIG. 2 shows a flow chart of a control method for a diesel engine according to a preferred embodiment of the present invention.
The control unit 20 , which performs control of the diesel engine using a pre-installed program, receives driving detection signals from the detection unit 10 in step S 100 . That is, the vehicle speed sensor 11 and the accelerator pedal position sensor 12 detect vehicle speed and accelerator pedal position, respectively, then outputs corresponding detection signals to the control unit 20 .
The control unit 20 receives and reads the detection values of vehicle speed and acceleration pedal position from the detection unit 10 , then determines if the vehicle speed exceeds a vehicle speed limit stored in a memory of the pre-installed program in step S 110 . When the vehicle speed exceeds the vehicle speed limit, the control unit 20 determines that the vehicle is travelling on a downgrade (see FIG. 3 ), after which the control unit 20 outputs a predetermined fuel supply cut-off signal to the fuel injector 30 in step S 120 . The fuel injector 30 is driven by the fuel supply cut-off signal output by the control unit 20 to thereby discontinue the supply of fuel to the engine.
Next, the control unit 20 subtracts the vehicle speed limit from the presently detected vehicle speed and determines an error between the vehicle speed limit and the vehicle speed in step S 130 . The control unit 20 then sets an aiming speed as a first predetermined value (e.g., 6 kph) stored in the memory of the pre-installed program in step S 140 .
After step S 140 , the control unit 20 subtracts the aiming speed from the error between the vehicle speed limit and the vehicle speed to derive an aiming error Am_Err in step S 150 . The control unit 20 then determines if the aiming error Am_Err is greater than 0 in step S 160 .
When the aiming error Am_Err is greater than 0, the control unit 20 sets an enable vehicle speed as a second predetermined value (e.g., 4 kph) stored in the memory of the pre-installed program in step S 170 . However, when the aiming error Am_Err is less than 0, the control unit 20 sets the enable vehicle speed to 0 in step S 171 . After either step S 170 or S 171 , the control unit 20 subtracts the error between the vehicle speed limit and the present vehicle speed from the enable vehicle speed to thereby derive an enable error En_Err in step S 180 .
Subsequently, the control unit 20 determines if the enable error En_Err is greater than 0 in step S 190 . When the enable error En_Err is greater than 0, the control unit 20 sets an offset vehicle speed Off_set as a third predetermined value (e.g., 20 kph) stored in the memory of the pre-installed program in step S 200 . At this time, it is determined that the vehicle has reached the end of the downgrade.
However, when the enable error En_Err is not greater than 0 in step S 190 , the control unit 20 determines that the vehicle is still on the downgrade such that the offset vehicle speed Off_set is set to 0 in step S 201 . Either after step S 200 or S 201 , the control unit 20 determines if the accelerator pedal position has reached or is greater than, by operation of the driver, a fourth predetermined value in step S 210 . When the accelerator pedal position is less than the fourth predetermined value, the control process is ended.
When the accelerator position has reached the fourth predetermined value, the control unit 20 adds the offset vehicle speed Off_set to the vehicle speed limit stored in the pre-installed program to thereby obtain a new vehicle speed limit New_Speed in step S 220 . The control unit 20 then determines if the present vehicle speed is less than the new vehicle speed limit New_Speed in step S 230 .
When the present vehicle speed is less than the new vehicle speed limit New_Speed, the control unit 20 outputs a fuel supply control signal to the fuel injector 30 such that the vehicle increases to a speed corresponding to the position of the accelerator pedal operated by the driver in step S 240 . However, when the present vehicle speed is greater than the new vehicle speed limit New_Speed, the control unit 20 outputs a fuel supply cut-off control signal to the fuel injector 30 in step S 250 . The fuel injector 30 acts accordingly.
In the control method of the present invention as described above, after determining when the vehicle is driving on a downgrade, the vehicle speed limit is increased to a specific level to enable an increase in speed by the operation of the accelerator pedal. Accordingly, the momentum of a downgrade can be used.
Although preferred embodiments of the present invention have been described in detail hereinabove, it should be clearly understood that many variations and/or modifications of the basic inventive concepts herein taught which may appear to those skilled in the present art will still fall within the spirit and scope of the present invention, as defined in the appended claims.
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A method for controlling a diesel engine, is provided where when a vehicle is traveling on a downgrade, an enable vehicle speed is set according to a calculated aiming error, and a vehicle speed limit is modified based on an accelerator pedal position and by an offset value that is set according to an enable error calculated based on the present vehicle speed limit, the present vehicle speed, and the enable vehicle speed.
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This is a continuation of application Ser. No. 647,752 filed Jan. 9th, 1976 and now abandoned.
BACKGROUND OF THE INVENTION
The present invention relates to clinical evaluation of hearing loss and more particularly to an improved probe tip for use with ear test equipment.
There is a test procedure for evaluating hearing losses and/or ear disease, for example, which is known as Acoustic Impedance Testing or Impedance Audiometry. The test uses acoustical measurements made within the patient's outer ear canal and includes the step of closing off the ear canal adjacent to the patient's tympanic membrane with a probe. The probe has a tip to form an air seal for permitting the control of the air pressure within the sealed cavity and the transmission to and receipt of sound signals from the closed cavity. Several other hearing tests use probes with tips.
The equipment for these tests has been used heretofore with a number of ear probe tips for forming the seals. The probe tip of the present invention is improved whereby it forms a better and more sure seal permitting the tests to be done quickly and conveniently without critical adjustments of the probes or of the probe supports. This is of particular value in the case of children and certain other patients who may have short attention span or an inability to cooperate in the test procedures.
Accordingly, an object of the present invention is to provide improved probe tips for clinical evaluations of hearing losses or other ear problems.
Another object of the present invention is to provide an improved probe tip of more efficient form for providing better sealing and for use with various probe supports including hand held probes and others. It likewise eliminates losing or displacing the tip within the external auditory canal.
Other and further objects of the invention will be obvious upon an understanding of the illustrative embodiment about to be described or will be indicated in the appended claims, and various advantages not referred to herein will occur to one skilled in the art upon employment of the invention in practice.
BRIEF DESCRIPTION OF THE DRAWING
A preferred embodiment of the invention has been chosen for purposes of illustration and description and is shown in the accompanying drawing forming a part of the specification, wherein:
FIG. 1 is a perspective view of a preferred embodiment of the tip in position on a hand held probe.
FIG. 2 is a vertical sectional view of the probe tip in test position.
FIG. 3 is a vertical sectional view of the probe tip corresponding to FIG. 2 but with the probe differently positioned.
FIG. 4 is an exploded perspective view of the probe tip and a supporting probe end.
DESCRIPTION OF THE PREFERRED EMBODIMENT
This invention relates particularly to an improved probe tip for use in performing a number of tests in connection with a clinical evaluation of hearing losses or other problems. The following description will refer to typical tests in a general way, particularly with reference to FIGS. 2 and 3 to provide a background for the description of the elements of the tip and its improved features as used on a typical probe. The tip is particularly useful with a hand held probe, for example, as used in acoustic impedance tests in the setup illustrated diagrammatically in FIG. 1. The tip is also useful with a variety of differing probes and probe mountings including head bands.
FIG. 1 illustrates one form of a hand held probe for use with test equipment for a test known as Tympanometry. This test uses a probe 1 with a tip 2 in accordance with the invention to form a closed-off cavity 3 within the patient's ear canal 4. FIGS. 2 and 3 illustrates a probe 1 equipped with a tip 2 in accordance with the present invention held at the patient's ear canal 4 so that the tip 2 closes off and hermetically seals the cavity 3 adjacent to the ear tympanic membrane 5. The resilient cuff or tip 2 on the ear probe 1 is positioned on the inner end of the probe 1 for forming the air-tight or hermetic seal with the canal 4 walls at a generally ring-like area 6.
The tympanometric test provides for the transmission of a sound signal wave of a predetermined frequency and volume through the probe 1 to the sealed-off cavity 3. The testing involves the supply of this sound signal to the cavity 3 with the tympanic membrane 5 being stressed or conditioned by the adjustment of the air pressure within the sealed cavity 3. The tympanometric measurements are made for determining ear drum compliance changes as the air pressure is altered within the sealed cavity 3.
Probes 1 also are used in a generally similar way with sealed ear canals for Static Compliance Testing and for Acoustic Reflex Threshhold tests. In the Static Compliance Test, which measures the middle ear sytem mobility, a condition of the testing also requires a setting and an adjustment of air pressure within the sealed-off ear canal 4.
The Improved Probe Tip
The improved tip 2 will now be described in detail with reference to the drawing. As illustrated in the drawing, the tip 2 comprises a central support portion 7 adapted for engagement with the end of the rigid probe member 1. The tip has a rounded convex skirt or flange 8 projecting from the inner end of the central support portion 7. The improved tip 2 is preferably formed of a soft resilient material such as latex, silicon or a plastic resin with a corresponding softness and resiliency. The support portion 7 includes a central aperture 9 which preferably has a cross-section of increasing size outwardly of the support 7 of the general form illustrated in FIG. 4 for facilitating the application of the tip 2 to the probe 1 and for firmly retaining the tip 2 in place on the probe 1 during testing. This portion of the tip 2 fits into locking engagement with a lock or gripping flange 10 on the inner end of the hollow metallic or other rigidly formed probe 1.
The convex and projecting flange 8 preferably has a rounded shape as substantially as illustrated. This mushroom-like shape together with the relatively thin cross-section and flexible nature of the material results in the formation of a tight seal between the outer surface of the probe flang 8 and the walls of the ear canal 4 under test.
A tight seal is obtained regardless of the precise alignment of the probe with respect to the opening in the ear canal 4. FIG. 2, for example, illustrates the probe 1 being aligned with an essentially axial alignment with the ear canal 4 and with a seal being provided more or less uniformly around a ring-like area 6 on the flange tip 2.
FIG. 3 illustrates a seal being formed even where the probe 1 may be presented to the ear canal 4 at an angle. In this case, a seal is formed on an outer portion 11 of the flange 8 on one side of the tip 2 and at a more centrally positioned area 12 of the flange 8 on an opposite section of the tip 2.
This sealing capability permits a tight seal to be made for satisfactory testing without requiring precise positioning of the test probe 1 and without requiring the application of substantial forces on the probe 1. This makes the new tip 2 particularly useful for a variety of test instruments including a hand held probe 13 which may have the general form illustrated in FIG. 1.
A hand held probe is applied to the ear of the patient under test while being held in the clinician's hand. The improved tip 2 facilitates such a hand held operation as it permits a seal to be made without difficult or cirtical probe alignment being required to establish or to maintain the desired ear canal air pressure.
The improved sealing capacity of the tip 2 alos adapts it for use with other probes including those mounted on adjustable head bands as it also eliminates the need for any critical positioning of the probes on the bands during the testing.
It will be seen that an improved probe tip has been provided which is adapted for hand held use and other uses and which thereby provides for fully satisfactory acoustic testing of a patient's hearing with a decrease in the manipulations required by the clinician. This results in a reduction in the required test time as well as providing increased comfort for the patient being tested.
As various changes may be made in the form, construction and arrangement of the parts herein without departing from the spirit and scope of the invention and without sacrificing any of its advantages, it is to be understood that all matter herein is to be interpreted as illustrative and not in a limiting sense.
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A tip for an ear test probe is disclosed for use in clinical evaluations of hearing problems. There are a number of important tests for evaluating hearing system losses which are based upon measurements taken in patients' external ear canals using a probe which uses a tip to seal the ear canal. An improved tip is described for such tests. The tip has an improved curved flange structure which helps to insure perfect sealing of the ear canal without requiring precise probe positioning or high probe sealing pressures.
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This invention relates to a method and apparatus for selective multi-color dyeing of individual yarns and producing therefrom a predetermined complex design in a tufted carpet, which can be repeated in continuous production. The invention particularly relates to carpets made by machines commonly called tufting machines in which yarns fed to individual needles of a continuously reciprocating bank of needles are pushed through a backing sheet to form tufts, stitches or loops that may be cut or remain as uncut pile in the finished carpet.
PRIOR ART
Heretofore many variations of tufting machines have been developed which are capable of producing cut or uncut pile of uniform or different heights -- high, low or intermediate -- and a large variety of combinations of the same. An almost infinite variety of designs have been produced using one or more or all of said varieties of pile producing a sculptured effect and/or including color variations.
When using differently colored yarns which have been pre-dyed in bulk, practical considerations limit production of many desirable designs even though a myriad of multi-colored designs have been made.
When producing floral, modernistic, oriental or other complex designs different colors have been sprayed on the pile of completed carpets, or have been printed in various ways thereon, to produce the desired design. However, problems have arisen in applying the dyes to finished pile, due to inability to penetrate the pile and to apply the dyes evenly and completely and only in the areas (sometimes very small) where the dye should be and remain.
It has been proposed to apply different colored dyes to the individual yarns at spaced predetermined positions along their lengths, determined with reference to a pattern or design that is ultimately to appear in the finished carpet. However, for various reasons, these proposals have been impractical or have not been commercially successful.
SUMMARY OF THE INVENTION
According to the present invention a machine and method are provided in which the yarns are prepared to be dyed, and are then dyed individually at different places along their length with different colors; and they are prepared for delivery to a tufting machine and are fabricated into a carpet bearing a predetermined complex design. All this is done without interruption and without variation of the relationship of the yarns, one to another. More specifically, the individual yarns are conditioned for dyeing by being led from a supply in the form of a sheet to a bath containing cleansing and wetting materials, after which the yarns are squeezed between pressure rollers to remove most of the liquid. Then the yarns are directly passed individually over a series of dye pick-up rolls. In the course of this passage, the yarns are lowered into contact with one or more or all of the pick-up rolls for predetermined limited times to cause predetermined variable lengths of the individual yarns to be individually dyed. The colors and lengths of the dyeing are determined by the desired pattern that is to appear as the dyed segments of yarn become loops, tufts or stitches in the carpet fabric.
After dyeing, the sheet of yarns may immediately enter a steam chamber wherein the dye is fixed in the yarn or the dye setting may be omitted at this stage and the sheet may immediately enter a drying chamber from which the yarns are individually fed through identical length guide tubes directly to the conventional tufting machine, whose feed rolls are synchronized with and have the same peripheral speed as the rolls that fed the yarn sheet to the dyeing portion of the apparatus.
Throughout, the positions of the individual dyed yarns relative to one another are maintained so that as they enter the tufting machine they will have the same relationship as when the dyes were applied. Thus, in the carpet fabric the colored tufts will appear in a relationship or pattern which was predetermined before the dyes were applied.
Time delay means are provided to delay disengagement of the yarns from the dye-pick-up rolls and to cause this to occur simultaneously with complete cessation of the movement of the tufting machine to compensate for momentum of the tufting machinery when the power to it is shut off vis-a-vis the instantaneous lifting of the yarn from the pick-up rolls.
Provision is also made for easy and quick removal of the dye-pick-up rolls and their troughs for cleaning, replacement or repair.
The several objects and advantages of the invention will become apparent as it is described in connection with the drawings.
DESCRIPTION OF THE INVENTION
In the drawings,
FIGS. 1 and 2 are elevational views showing diagrammatically the method and apparatus embodying the invention, FIG. 2 being a continuation of FIG. 1.
FIG. 3 is a plan view of the end of the apparatus of FIG. 1 where a sheet of yarns enters and is subjected to treatment before dyeing.
FIG. 4 is a side elevational sectional view taken along line 4--4 of FIG. 3 showing the yarn passage through the position of the apparatus shown in FIG. 3.
FIG. 5 is a side elevational view of the end of the apparatus of FIG. 1 showing the driving mechanism for the draw and squeeze rolls.
FIG. 6 is an elevational view partly broken away and partly in section of a dye-pick-up roll and its trough removed from the dyeing machine.
FIG. 7 is a sectional view taken along line 7--7 of FIG. 6.
FIG. 8 is a circuit diagram of the control of the motors and switches which operate the apparatus.
FIG. 9 is a fragmentary side elevational view showing diagrammatically one of the pattern drums.
Referring to the drawings, the yarns Y from a creel or spools, are spread into the form of a sheet, are threaded up through a horizontal yarn guide plate 9 having several rows of staggered holes, from which the yarns pass around a horizontal idler roll 13 and around and over a parallel draw roll 12 mounted on a horizontal shaft 12s supported in bearing 12b in the machine frame F above the idler roll 13. The draw roll has a rough surface and is power driven and pulls the yarns from the supply.
The machine frame F may be of any suitable form and number of parts to support the various elements of the machine as described herein.
PRE-TREATMENT OF THE YARN ENDS
In order to prepare and condition the yarns so that they will pick-up and retain dyes, later to be applied at spaced places along the length of the yarns, a bath is provided in a trough or like receptacle 17.
The bath in the receptacle or trough 17 preferably contains common wetting, cleansing, and anti-foaming agents. The precise composition and character of the wetting, cleansing, and anti-foaming agents is selected and determined in accordance with the composition of the particular fibers of the yarn and the dyes used. The composition of these agents per se is not a part of this invention. These agents are available on the market from various suppliers, and they are sold under a number of trade names. It is important, however, that the yarns be treated at this stage in the process in order that dye which is applied in the immediately-following dyeing stage of the process is absorbed and penetrates the fibers of the yarns in the short time that the yarns are subjected to the dyes. Even though wetting and anti-foaming agents may also be present in the dye bath to facilitate adherence of the dyes on the hereinafter described dye-pick-up rolls, it is important to pretreat the yarn ends so that they will be in optimum condition to accept the dye.
The yarn sheet passes from the draw roll 12 into the bath under the first (20) of a pair of parallel horizontal squeeze rolls 20, 22 which are mounted on shafts 23, 25 journalled in bearings in bearing blocks 29, 29' supported from the machine frame at each end of the rolls. The passage of the yarns between the squeeze rolls leaves the yarns with about 80% moisture content. That is to say if 100 represents the weight of the dry yarn, its weight on leaving the squeeze rolls would be 180. From these rolls, the yarns go directly to dyeing apparatus which in the example illustrated is provided with means to apply four colors in succession at spaced points along each individual yarn end, or pair or small group of yarn ends.
THE DYEING APPARATUS
In order to apply dye at spaced positions along the yarns, four (or more or less) identical stainless steel dye-pick-up rolls 32, 52, 72, 92 are provided, mounted on shafts 34, 54, 74, 94, and positioned over troughs 30, 50, 70 and 90, containing dyes of different colors and additive chemicals to assist adherence of the dyes to the pick-up rolls, to penetrate the yarn, to fix the dye to the fibers and to reduce foam. The lower part of each roll is immersed in the bath and picks up dye as the roll turns. The shaft 34 of roll 32 is journalled in bearings in bearing blocks 38. The trough 30, bearings and roll 32 are supported in such a way as to be removable as a unit sidewise from the machine as will presently be described. The rolls 52, 72, 92 are similarly supported and positioned with respect to their dye troughs and are removable.
Above each pick-up roll is mounted a bank of yarn-end-manipulating assemblies located in one, two or more parallel rows extending parallel to the rolls. For example, in a typical 36 inch width machine, there were 48 assemblies in each of two rows, with the assemblies in the second row staggered or offset from the first row, by reason of space limitation requirements. Thus, there were a total of 96 assemblies across the 36 inches of width of the machine. In the typical machine being described, two "repeats" were provided. This was done by having a pair of yarn ends under control of each piston rod of each of the hereinafter described yarn manipulating assemblies, thus providing a total of 192 yarns to be fed to the tufting machine.
Each yarn-manipulating assembly comprises a vertically mounted pneumatic cylinder such as 40 containing a plunger with a stem or piston rod such as 42 extending out the lower end in a position offset from directly-vertical position over the roll. The plunger and roll are normally biased upwardly by a coiled compressing spring within the cylinder 40. A conventional electromagnetically operated solenoid valve (not shown) controls inlet and exhaust of air to and from the cylinder through a connection such as 44 to an air supply.
The details of the pneumatic assemblies and solenoid valves need not be described since they are known pieces of equipment having been available on the market and used for various purposes in various machines (see Hackney et al. U.S. Pat. No. 2,954,865).
The individual yarn ends (or pair of ends in the example being described) pass through openings at the lower end of the downwardly extending portions of the piston rods. These openings are preferably apertures with straight horizontal bottom edges and generally of rectangular shape. Alternatively the openings may have open bottoms. Each of the assemblies is placed so that when its piston and rod are down, the yarn end or ends it carries will be pushed down into contact with the adjacent pick-up roll. More specifically, the first assembly controls the position of the yarn Y between the squeeze roll 22 and itself. In the inactivated position the rod 42 is up, in the position shown in FIG. 1, and the yarn is out of contact with the pick-up roll 32. When activated, the rod 42 moves down carrying the yarn into contact with the pick-up roll 32.
In corresponding fashion when the rod 62 of the second assembly is inactivated (up, as shown in FIG. 1), the yarn is held from contacting the roll 52, whether or not the first assembly is activated. But when the second assembly is activated, the rod 62 moves down and carries the yarn into contact with pick-up roll 52 as shown in dashed lines in FIG. 1.
And, likewise, when rod 82 of the third assembly is up, the yarn is held from contacting the third pick-up roll 72, whether or not the rod 62 of the second assembly is activated.
From the explanation given, it will be understood how activation of the fourth assembly will cause the yarn to contact the fourth pick-up roll (as shown in FIG. 2), or to be freed to move up from such contact upon deactivation.
Since the yarn is constantly moving forward through the machine, the yarn end will be dyed with different colors along its length. The places where a particular color is applied will depend upon when the particular dye assembly is activated. The length of the stretch or segment that is dyed will depend on how long the activation continues and how fast the yarn sheet is moving.
The variety of color sequences is infinite along any yarn end or ends carried and controlled by the four longitudinally positioned assemblies (which may be more or less in any particular machine) and so also are the lengths of individual dyed stretches, therealong. Moreover, the variety of colorings of yarns transversely across the sheet is infinite since the adjacent yarn ends which are carried by individual transversely adjacent assemblies can be dyed entirely independently of each other.
In order to provide a support for a sagging yarn or a broken yarn, a thin wire 45 such as a piano wire is tautly stretched horizontally and transversely across the machine about midway between the dye-pick-up rolls 32 and 52. The wire is located slightly, e.g., approximately 1/4 inch, below the plane of the tops of rolls 32 and 52 and is secured to the sides of the machine frame. Similarly, wires 45' and 45" are located between rolls 52 and 72 and 72 and 92.
Control of the solenoid valves which activate the pneumatic yarn-manipulating assemblies may be by a power driven rotating pattern drum 80 with conductive fingers 81 rubbing over conductive and non-conductive portions of a pattern laid out on the surface of the drum. See FIG. 9.
Alternatively, other pattern controls may be employed, of which the digital pattern control as disclosed in the Strother et al U.S. Pat. No. 3,722,434 assigned to the assignee of this application is only one example.
PATTERN CONTROL
A pattern is prepared and laid out on a drum such as 80 in FIG. 9 for controlling the movement of each individual yarn as it passes over the first dye-pick-up roll 32; and likewise, separate drums are provided and separate patterns are prepared to be put on each drum for each of the other dye-pick-up rolls 52, 72 and 92. All drums are alike and all rotate at the same speed.
There is a need for separate pattern drums and patterns for controlling the yarn movement in connection with each assembly because of complications arising when an attempt is made to use only one drum and pattern having conductive and non-conductive areas and switch fingers for all four solenoid valves for all of the yarn ends in the yarn sheet. Even in small 36 inch width machines, there are space problems and overlapping control lines due to the hundreds of elements involved. Similar problems arise when the pattern control consists of light and dark areas with light conductive plastic rods with associated light responsive electric switching devices, sometimes known as electric-eyes, are used.
Due to the longitudinal spacing along the length of the machine of the yarn control assemblies and dye rolls, the zero or starting point of the patterns as laid out on the pattern drums is different on each drum. In other words, the controlling action of the drums must be coordinated; and the start of the patterns on the second, third and fourth drums must follow the start of the first drum by the amount of time taken for the yarn to travel from the first drum to the second, third or fourth drum. Having determined the starting point, the pattern layout may be determined for each drum.
DYE ROLL AND TROUGH REMOVAL
Because the apparatus runs for considerable periods of time and is subject to wear and because the dye baths and dye-pick-up rolls must be maintained in clean and unimpaired operating condition, it is desirable to be able to clean, repair or replace the dye-applicator rolls and troughs quickly and easily. For that purpose, each trough and its dye applicator roll is assembled as a unit and fabricated so that the unit can be removed separately from the machine with great ease and facility without the other dye units being affected. Since all the units are mounted in the same manner, a description of the first unit will suffice.
Roll 32 is made of stainless steel and is located in the metal trough 30. The trough is or may be of a stainless steel sheet bent into U-shape as at 31 with folded over portions forming parallel side walls 33 which extend downwardly and are welded or otherwise secured along its bottom edges to a flat horizontal bottom plate 35 (see FIG. 7). The plate 35 is mounted at each end on inverted T-shaped pedestals 37 which rest on the floor.
The ends of the U-portion 31 of the trough are closed by flat vertical plates 39a, 39d which are welded or otherwise secured to the trough. To support the roll 32 bearing blocks 38 are mounted on the end plates 39a, and on an intermediate wall 39b which support bearings for the ends of the shaft 34.
One end of the shaft extends outwardly in the direction in which the unit is to be removed from the machine and has a drive gear 41 mounted thereon by which the roll 32 is rotated when the unit is in place in the machine. At the other end of the trough, the intermediate wall 39b and end wall 39d form a compartment 39c. The intermediate wall 39b does not extend all the way to the bottom of the trough, thus providing a passage for flow of the dye between the compartment 39c and the central part of the trough. A removable open-ended overflow stand pipe 35p is positioned over a machined orifice and outlet pipe 35x in the bottom of the compartment 39c making a tight joint. Upon lifting of the stand pipe, the dye of the trough may be drained. But while the stand pipe is standing in place, the level of dye in the trough is maintained at not more than the height of the stand pipe. Dye may be continuously fed into the trough and circulated in any suitable conventional fashion.
Although the trough and roll unit above described is horizontally removable, it will be understood that the units could be individually vertically removable.
After the final dye assembly has been passed by, the yarn sheet goes into a conventional drying chamber 115 wherein the yarns are thoroughly dried.
As an alternative, instead of deferring setting of the dye, the yarn may be carried on into a conventional steam chamber (not shown) between the dyeing stage and the drying chamber wherein the steam causes the dye to penetrate into the fibers of the yarns and to be set.
FEED TO THE TUFTING MACHINE
After drying, the yarns are fed into a horizontal yarn guide plate 116 secured at the exit end of the drying chamber 115. The guide plate 116 has holes arranged in it, like the entrance yarn guide plate 9, for each individual yarn end. Attached to the plate 116 over each hole is a yarn guide tube 118 made of transparent synthetic plastic material or any other suitable tubular material. In the previously mentioned typical example there were 192 holes and 192 guide tubes. The whole group or set of yarn guide tubes is led conveniently overhead to a conventional tufting machine, designated generally by numeral 120. The tubes 118 are secured at their exit end to a yarn guide plate 122 like plate 116 supported from and transversely across the tufting machine.
The tufting machine may be a kind that produces pile of uniform height; or it may be of the kind that produces high or low loop pile or a combination thereof (as, for example, by said U.S. Pat. No. 2,954,865) or it may produce cut or loop pile or a combination thereof (as, for example, by Bryant et al. U.S. Pat. No. 3,187,699). One yarn end is fed through each guide tube. The tubes 118 must be of equal length, so that the yarns exiting therefrom will be in the same relationship laterally in the sheet as they were on entering the tubes and as maintained throughout the processing, from the time the dye was applied thereto. If there is a difference in lateral relationship of the yarns at the tufting needles from the predetermined relationship when leaving the dye rolls, the colors will appear off-set in the carpet and not in conformity with the desired pattern.
As the yarn ends exit from the guide tubes 118, they pass between one or more pairs of power driven feed rolls 124, 126, of the tufting machine. Two pairs of feed rolls are preferred, in order to avoid slippage and misregister of the yarns at the feed stage and to provide more positive feed of the yarn ends. The feed rolls 124, 126 are synchronized with the draw roll 12, which, it will be recalled, controls the feed of the sheet of yarns to the dye-pick-up rolls, and are geared so that the peripheral speeds of the draw roll 12 and the machine feed rolls 124, 126 are the same, whether or not the diameters of the draw roll 12 and the feed rolls 124, 126 are the same.
SYNCHRONIZATION OF YARN FEEDS
Synchronization of the tufting machine yarn feed rolls 124, 126 with draw roll 12, and squeeze rolls 20, 22 of the dyeing machine is accomplished by chain and gear drive connections as follows:
Referring to FIG. 5, mounted on one extended end of shaft 25 of squeeze roll 22 is a gear 15. A similar gear 14 is mounted on an extended end of shaft 12s of the draw roll 12. Trained around gears 14 and 15 is a chain 16 causing the shafts 12s and 25 to rotate in unison, and together with them the draw and squeeze rolls 12 and 22, respectively, which are of the same diameter and therefore rotate with the same peripheral speed.
Also on squeeze roll-shaft 25 is another gear 18 around which is trained a chain 19 which is guided around idler gears (not shown) and in tracks (not shown) to the end of the dyeing machine and onward to gears (not shown) on the shafts of tufting machine rolls 124, 126 (see FIG. 2). This gearing causes the tufting machine rolls 124, 126 to rotate at the same peripheral speed as the draw and squeeze rolls, and also maintains the rotation of all said gears and rolls in synchronism.
SYNCHRONIZATION OF CESSATION OF YARN DYEING WITH CESSATION OF TUFTING MACHINE MOVEMENT
The tufting machine is driven by an electric motor M-1 under control of a conventional electromagnetic motor control switch EMS as diagrammatically shown in FIG. 8.
From the main shaft of the tufting machine, through a conventional adjustable reduction gear box and V-pulleys and V-belt (not shown), the yarn feed rolls 124, 126 are driven; and likewise the draw roll 12 and squeeze roll 22 are driven synchronously therewith as above described.
The drums of the pattern control mechanism are driven by a chain and gear connection 26, 27, 28 from a gear 26 on the squeeze roll shaft 25 and gear 28 on the pattern drum shaft by chain 27 (see FIGS. 3 and 9). The ratio of this gearing is determined for rotation of the pattern drum with a linear speed which will cause production of the dye pattern on the yarns of the yarn sheet in a predetermined length so that ultimately, when the yarn is tufted into a carpet in the tufting machine, the desired pattern will appear in the carpet.
Thus one motor, M-1, drives the tufting machine and its yarn feed rolls 124, 126 and squeeze roll 22, draw roll 12 and the pattern drums.
The dye pick-up rolls are driven by a variable speed motor M-2 through gear and chain connections or by any other connection. These dye pick-up rolls rotate continuously while the dye is in the receptacles 30, 50, 70, 90 which helps to keep the dye mixed. Each roll may be driven separately if so desired.
When the power to the tufting machine motor is turned off by pressing push button switch PB-2, the tufting machine, due to inertia of its motor and parts, does not stop instantaneously but continues for a few cycles of reciprocation. In contrast, when the electric power is cut off to the electrical elements of the pattern control system, specifically the pattern drums and solenoid valves, the solenoid valves close the air supply to the pneumatic cylinders 40. Thereupon, the piston rods 42, 62, 82, 102, being spring biased upwardly, immediately rise and the yarn sheet also rises out of contact with the dye-pick-up rolls. This prevents the yarns from picking up excess dye from the continuously rotating pick-up rolls.
In order to keep the pattern control operating while the tufting machine and the yarns are coming to a halt, a conventional time delay switch TDS, which is controlled by the electromagnetic motor control switch EMS, is placed in series circuit from the power line L 2 to the solenoid valves SV. The time delay of the opening of switch TDS is adjustable, but the closing is simultaneous with the closing of the contacts of the electromagnetic controller EMS.
Since the pattern drums are mechanically driven by gear and chain connections synchronously with the yarn feed rolls 124, 126 and draw roll 12 and squeeze roll 22, the drums will slow down and stop rotating as the rolls and yarn movement stop. The opening of the time delay switch will be adjusted to coincide with the dead-stop of the tufting machine, so that yarn rise from pick-up rolls will occur at that moment.
To start operations, push button switch PB-1 is closed. This closes the circuit to, and energizes, the coil of the electromagnetic control switch EMS, which closes its holding contacts a and b and the contacts c and d in the circuit to motor M-1, and auxiliary contacts e and f to the electric solenoid coil of time delay switch TDS. Thus, the tufting machine, the dyeing apparatus, and pattern control apparatus are simultaneously activated electrically and mechanically, with the pattern controls and yarn moving rods 42, 62, 82, 102, in the same condition as when they stopped.
The switches shown diagrammatically in FIG. 8 may be purchased on the market and are of known and common construction. Therefore, their structural details and circuitry need not be described herein.
Referring to the typical example, since 192 yarn ends pass through the dyeing machine, there will be 192 ends available to the tufting machine. And since 96 ends constitute each repeat (for convenience referred to as the "left" and "right" repeats) and since each pneumatically controlled piston rod controls a pair of yarn ends, two yarn ends will be dyed the same, e.g., the first yarn of the left repeat will be the same as the first yarn of the right repeat. Therefore, dyed yarns will be available to make two identical patterns across the carpet fabricated by the tufting machine. To accomplish this, the yarns issuing from the drying machine must be fed in a particular way to the tufting machine.
Assuming the yarn ends are numbered consecutively and the tufting machine needles are likewise numbered consecutively in the same direction, in the left repeat:
Yarn No. 1 will pass through tube No. 1 to needle No. 1;
Yarn No. 3 will pass through tube No. 3 to needle No. 2;
Yarn No. 5 will pass through tube No. 5 to needle No. 3;
Yarn No. 7 will pass through tube No. 7 to needle No. 4, and so on, until the end of the left repeat, where:
Yarn No. 185 will pass through tube No. 185 to needle No. 93;
Yarn No. 187 will pass through tube No. 187 to needle No. 94;
Yarn No. 189 will pass through tube No. 189 to needle No. 95.
Yarn No. 191 will pass through tube No. 191 to needle No. 96.
In the right repeat:
Yarn No. 2 will pass through tube No. 2 to needle No. 97;
Yarn No. 4 will pass through tube No. 4 to needle No. 98;
Yarn No. 6 will pass through tube No. 6 to needle No. 99;
Yarn No. 8 will pass through tube No. 8 to needle No. 100, and so on, until the end of the right repeat, where:
Yarn No. 186 will pass through tube No. 186 to needle No. 189;
Yarn No. 188 will pass through tube No. 188 to needle No. 190;
Yarn No. 190 will pass through tube No. 190 to needle No. 191;
Yarn No. 192 will pass through tube No. 192 to needle No. 192.
In other words, one yarn from each pneumatic control from left to right consecutively (1 through 96 pneumatic controls) will go to needles 1 through 96 consecutively forming the left 18 inches width repeat.
Also, one yarn from each pneumatic control from left to right consecutively (1 through 96 pneumatic controls) will go to needles 97 through 192 consecutively forming the right 18 inches width repeat.
The pattern repeat width may be altered by adding more yarn ends, manipulating assemblies, and pattern pick-up fingers (in the case of the continued use of the pattern drums).
Thus, each repeat at the entrance end provides two identical patterns side-by-side in the carpet; and a method is provided whereby the dyeing of a plurality of yarn ends simultaneously enables the production of an equal number of identical patterns side-by-side in a carpet.
Obviously, the number of ends under control of each individual piston rod will determine the number of patterns that can be duplicated across the carpet, practical considerations imposing the only limitation on the number.
The product produced by the tufting machine is an intermediate product. If the dye setting has been deferred, the intermediate product may be treated when convenient, conventionally in a steam chamber or otherwise to set the dye, and then may be finished in conventional fashion by application of adhesive and a heavy backing sheet.
Or, in the case of the previously mentioned alternative of setting the dye immediately after dyeing, the tufted product resulting from the tufting operation may be finished when convenient, by application of adhesive and a strong backing sheet as usual.
Modifications within the scope of the invention will occur to those skilled in the art. Therefore, the invention is not limited to the details of the apparatus and method as illustrated and described.
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The apparatus and the method of the invention dyes the yarn ends of a sheet thereof individually at predetermined positions along their lengths and manufactures tufted carpets therefrom in a tufting machine to provide a predetermined multi-colored complex pattern in the carpet. The invention includes pretreatment of the yarn in a wetting and cleansing bath, removing excess bath liquid in preparation for dyeing, synchronizing the yarn feed at the start with the feed to the tufting machine, simultaneous dyeing of pairs of adjacent yarn ends and separating them for delivery to the tufting machine in an arrangement to produce identical patterns side-by-side in the carpet.
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FIELD OF THE INVENTION
The present invention relates to one-directional drive apparatus which allows drive in one direction and prevents it in the other direction.
More specifically, the invention relates to a drive apparatus capable of transmitting a rotation motion from a motive source such as an electric motor to a driven source but prevents transmission from the driven source to the motive source. One of the applications of such apparatus is associated with a vehicle in which the window glass is opened and closed by a motor operated by the driver. However, the motor is desirably locked against its rotation to prevent the window glass from being opened or closed when the driver or any other person tries to open or close the window directly with his hands.
DESCRIPTION OF THE PRIOR ART
In the conventional type of drive apparatus opening and closing the window of a vehicle, the afore-mentioned one-directional drive mechanism with drive prevention in the opposite direction is achieved by using a reduction gear consisting of a worm and a worm wheel. In attempting to design a power actuation system including the above-mentioned drive mechanism, it was found that the reduction ratio of the worm reduction gear was very low. This, however, caused the need for a high-power electric motor to open and close the window. Therefore, in order to provide a compact and cheaper one-directional drive apparatus with drive prevention in the opposite direction, a coil spring is used.
Since one of the examples of the one-directional drive apparatus with reverse drive prevention mounted in a vehicle body is disclosed and claimed in the U.S. Pat. No. 3,757,472, the construction and operation thereof will now be explained hereinafter.
Referring now to FIG. 5, in operation of the drive mechanism when an electric motor (not shown) is activated, a spur gear 20 and pins 21 are rotated counter-clockwise or clockwise.
Since the four circumferentially spaced integral pins 21 of the spur gear 20 are pressed into holes 23 in a cup-like stamping 22, relative rotation between the pins 21 and the cup-like stamping 22 is prevented. In rotating counter-clockwise or clockwise, a flange portion 24 on the cup-like stamping 22 engages a tab 26 or 27 of a coil spring 25. At this time, if the cup-like stamping 22 is rotated counter-clockwise, the flange portion 24 engages the tab 26, and if rotated clockwise the flange portion 24 then engages the tab 27. In both directions, the flange's engaging the tab 26 or 27 imparts a slight counter-clockwise or clockwise rotation thereto which winds up the coil spring 25 such that the free outside diameter of the coil spring 25 becomes smaller.
An internal peripheral surface of a ring stamping 28 tightly engages the coil spring 25 which has a free-outside diameter larger than that of the ring stamping 28. Therefore, winding up the coil spring 25 disengages it from the internal surface of the ring stamping 28, this, then, allows rotation of the pins 21 and the cup-like stamping 22.
An output rotation disc 29 with a pinion 31 has four circumferentially spaced arcuate slots 30 which receive the pins 21 while allowing relative rotation between the cup-like stamping 22 and the output rotation disc 29.
Next, how the drive prevention in the other direction, namely, to drive the pins 21 from the output rotation disc side, is prevented, will now be explained.
When the output pinion 31 is rotated the output rotation disc 29 is also rotated. At this time, a circumferential wall 33 is spaced inwardly from the coil spring 25 and located in an arcuate space 267 defined between the tabs 26 and 27. Raising or lowering the window by the driver or any other person with his hands produces a counter-clockwise or clockwise rotation of the output pinion gear 31, this allowing a slight counter-clockwise or clockwise rotation of the disc 29 until an under-cut portion 32 engages either the tab 26 or the tab 27. Further rotation of the pinion gear 31 unwinds the coil spring 25 such that its free outside diameter becomes larger, so that the coil spring 25 tightly engages the internal surface of the stamped ring 28. The rotation torque thereon further tightens the coil spring 25 against the internal surface of the stamped ring 28, thus preventing the pinion 31 from further rotation.
However, such directional drive mechanism with reverse drive prevention as constructed above has short-comings as noted hereinafter. Namely, the diameter of the coil spring 25 is usually so designed that it is small whereby even a relatively small force is sufficient to possibly make the free outside diameter of the coil spring 25 larger in order to tighten the coil spring 25 against the internal surface on the ring stamping 28. This results in possibly breaking the small tabs 26 and 27.
SUMMARY OF THE INVENTION
It is, therefore, an object of the present invention to provide a compact, easily assembled, durable and reliable one-directional drive apparatus with reverse drive prevention.
Another object of the present invention is to provide a window glass opening and closing system incorporating such one-directional drive apparatus for easily opening and closing a window by the motor operated by the driver, but for locking the window against falling under its own weight or being pushed down or lifted up by the driver or any other person directly with his hands.
Briefly stated, in order to accomplish the afore-going objects, and according to features of the present invention, there are provided a coil spring 10 having a first integral tab 10b1 at one end and a second integral tab 10b2 at the opposite end making up an arcuate space defined between the tabs 10b1 and 10b2, a ring member 11 into which the coil spring 10 is inserted such that an internal peripheral surface of the ring member 11 engages the coil spring 10, an input rotating member 8 having a pair of projections spaced inwardly from the coil spring 10 and rotatably disposed in the arcuate space 10a, pivoting on almost center of the coil spring 10, and an output rotating member 12 having a pair of projections 12a inserted into an inward space 10c other than the arcuate space 10a between the tabs 10b, respectively, the output rotating member 12 being rotatably disposed in the inward space 10c, pivoting on almost center of the coil spring 10.
According to an additional feature of the present invention, there are provided first and second stamped reinforcement members 13 and 14 covering the both end sides of the coil spring 10 respectively, the first and second stamped reinforcement members also covering the first and second extended tab portions. According to the construction thus made above, a breaking or a transformation of the tabs 10b can be avoided by being protected by the first and second stamped reinforcement members 13 and 14 respectively when the coil spring 10 is wound up or unwound. Therefore, a dependable one-directional drive apparatus with reverse drive prevention is provided with a small-diameter coil spring 10.
BRIEF DESCRIPTION OF DRAWINGS
FIG. 1 is a side view in partial cross-section of an actuator used for a power-actuated window opening and closing system incorporating a one-directional drive with reverse drive prevention embodying the present invention;
FIG. 2 is a sectional view taken along line II--II of FIG. 1;
FIG. 3 is an exploded and perspective view of the parts shown in FIG. 2;
FIG. 4a is an exploded view in perspective of some of the parts shown in FIG. 3; and
FIG. 4b is an end view of the spring shown in FIG. 4a.
FIG. 5 is an exploded view in perspective of the corresponding part of the conventional drive mechanism.
DESCRIPTION OF PREFERRED EMBODIMENT
Hereinafter, an embodiment of the present invention will now be explained in detail with reference to the drawings of FIGS. 1 to 4, which is an actuator for opening and closing a window of a vehicle.
Referring now to FIG. 1, an electric motor 1 is a known type of a DC motor having a permanent magnet 2, which consists of an armature 3, a commutator 4, brushes 5 and an output shaft 6. A housing 7 may be divided into two parts, a housing part 7a in which the DC motor is disposed, and a housing part 7b in which a reduction gear is installed. FIG. 1 shows a side view of the actuator used for the power-actuated window opening and closing system incorporating the one-directional drive apparatus of the present invention, including a partial cross-section of the inside of the motor housing 7a and a partial top-view of the housing 7b.
The motor output shaft 6 is, as shown in FIG. 1, extended along of the housing 7b and is rotatably disposed by means of a not-illustrated thrust bearing in the housing 7b.
Referring now to FIG. 2 the output shaft 6, journaled in the housing 7b, has a worm 6a thereon which meshes with a worm wheel 8a on an input rotating member 8. A fixed shaft 9 is fixed by means of staking to the center portion of the housing 7b. The fixed shaft 9 is crimped at 9a to prevent itself from working out of the housing 7b such that the shaft 9 is erected perpendicular to the housing 7b.
The input rotation member 8 is arranged and rotatably disposed on the fixed shaft 9.
As best understood in conjunction with FIGS. 2 and 3, the input rotation member 8 consists of three members, the members being rotated all together. One of the members is a worm wheel body 81 comprising a toothed element 8a; another member is a damper 82 made of rubber; and the last member an end plate 83 connected through the damper 82 to the worm wheel body 81.
Between the end plate 83 and the worm wheel body 81 is bonded the damper 82 through which the rotation motion of the worm wheel body 81 is then transmitted to the end plate 83. Shapes of those three members are better illustrated in FIG. 3.
As also understood in FIG. 3, the end plate 83 has a pair of projections 83a, one of the projections 83a being inserted into the arcuate space 10a defined between the tabs 10b1 and 10b2 of the coil spring 10.
The coil spring 10 is shown in relation to first and second reinforcement members 13 and 14 in FIG. 4(a). The coil spring 10 has at both ends a pair of tabs 10b1 and 10b2, both extending toward the center of the coil spring 10, one of which is not seen by being hidden behind the spring portion 10 in the figure. FIG. 4(b) shows an end view of the coil spring 10 having the tabs 10b1 and 10b2. There is formed an arcuate space 10a defined between the tabs 10b1 and 10b2 and the arcuate peripheral portion of the coil spring 10. The coil spring 10 per se need not be a spring especially designed for achieving the object of this invention, but may be the same as the conventional type spring 25 referred to in FIG. 5.
As also well understood in FIG. 2, the coil spring 10 is inserted into an iron plate ring member 11 fixed to the housing 7b such that an internal peripheral surface of the ring member 11 engages an outer peripheral surface of the coil spring 10.
An output rotation member 12 is rotatably disposed on the fixed shaft 9. This output rotation member 12 includes a pair of projecting portions 12a which are inserted into an inward space 10c other than the arcuate space 10a defined between the tabs 10b1 and 10b2 and the periphery of the coil spring 10. The first reinforcement member 13 is located between the output rotation member 12 and the coil spring 10. On the other hand, between the input rotation member 8 and the coil spring 10 is inserted the second reinforcement member 14. The first and second reinforcement members 13 and 14 have almost the same shape, both having flange portions 13a and 14a housing the tabs 10b respectively, flange portions 13b and 14b, and circumferential wall or sleeve portions 13c and 14c inserted into the coil spring 10. These first and second reinforcement ring members 13 and 14 holding the coil spring 10 from both end sides are supported by an edge portion 11a of the ring member 11 and an edge portion 12b of the output rotation member 12 respectively as shown in FIG. 2.
The drive mechanism of the above embodiment will now be explained. The D.C motor 1 is activated rotating the input rotating member 8 which causes the required relative movement between the projections 83a and the second reinforcement ring member 14, which in turn causes the coil spring 10 to wind up, thereby its free outside diameter becomes smaller. This wind up releases the coil spring 10 from the internal surface of the ring member 11. However, opposite torques on each of the tabs 10b1 and 10b2 aid in the unwinding of the coil spring 10 and tighten its engagement with the internal surface of the ring member 11.
The projections 83a of the input rotating member 8 push the tabs 10b1 and 10b2 of the coil spring 10 with great force in a circumferential direction. However, the tabs 10b are prevented from being twisted or broken because that such force is first received by the first and second support members 13 and 14, and further those tabs 10b are housed in the bulge portions 13a and 14a, and protected thereby.
On the other hand, when the window is pushed down or lifted up by the driver or any other person with his hands, an output pinion 15 tries to rotate counter-clockwise or clockwise, thereby the projecting portion 12a engages the bulge portion 14a of the input reinforcement ring member 14 or the bulge portion 13a of the output reinforcement ring member 14 at 13a1 according to the direction of the rotation. However, even if the output pinion 15 is rotated either counter-clockwise or clockwise, the coil spring 10 is designed so that it tries to unwind and tightly engages the internal peripheral surface of the ring member 11, causing braking effects therebetween, thus preventing the rotation movements. Even at this time, the tabs 10b1 and 10b2 are prevented from being twisted or broken for the same reason, as explained above, because the tabs 10b1 and 10b2 are housed in the bulge portions 13a and 14a, and protected thereby.
In the embodiment of the present invention thus far described, as the input and output reinforcement ring members 13 and 14 are so provided as to protect the tabs 10b1 and 10b2 from being twisted or broken. As a result, there is provided a compact, cheaper, durable and reliable one-directional drive apparatus with reverse drive prevention with a coil spring having an even smaller diameter than that of the conventional type coil spring.
In the embodiment of the present invention thus far described, further, a smaller diameter coil spring which easily winds up or unwinds, or in other words, of which the free outside diameter can be easily changed, can be used. Thus the motor can easily control the opening and closing of a vehicle window, while on the other hand, the reverse drive prevention effect is improved to a great extent.
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A dependable and reliable one-directional drive apparatus with drive prevention in the other direction is presented wherein a first and second reinforcement ring members are used to protect mechanically fragile tab portions of a coil spring while using a small diameter coil spring. One of the applications of the drive mechanism is a power actuated window-drive apparatus for a motor vehicle.
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BACKGROUND OF THE INVENTION
In the chemical and energy providing industries there is a great demand for gas containing substantial amounts of hydrogen and/or carbon monoxide in various mixtures and purities. Such gas may be used, for instance, as a starting material for the manufacture of chemical products -- e.g., ammonia, alcohols, etc., -- as a reducing agent, as a clean fuel or in hydrogenation processes. A well-known and widely employed method for the preparation of such a gas is the partial combustion of hydrocarbonaceous fuels in a substantially void or hollow reactor. One of the attractive aspects of this process is its flexibility in the types of hydrocarbon fuels which can be converted to the desired gaseous products. Suitable hydrocarbonaceous fuels which may be subject to partial combustion in this non-catalytic process include normally gaseous and liquid hydrocarbons, e.g., middle distillates and light and heavy fuel oil, as well as liquid fuels mixed with solid carbon-containing particles such as the carbon soot typically obtained as a product of partial combustion. The combustion can be effected with oxygen, with air, or with air which has been enriched with oxygen. Frequently steam is added to the reaction mixture.
A frequently used hydrocarbonaceous fuel is a residual petroleum fraction which fuel contains ash-forming constituents. However, the percentage of ash is relatively low, i.e., generally not exceeding 0.05% weight, and in the conventional hollow reactors such an ash content presents no difficulties. The ash particles thus formed leave the reactor with the product gases and are separated from the gases by means known in the art, before, after or during cooling of the gases.
However, some hydrocarbonaceous fuels employed contain more than about 0.1%w finely dispersed solids. Liquid petroleum fractions with a far higher content of finely dispersed solids is obtained, for instance, from the mining and processing of tar sands. These tar sand deposits occur in very large deposits at various places on earth and present potentially valuable sources of petroleum. Dependent on the process employed to extract the petroleum from the tar sands, liquid petroleum fractions are obtained with a solids content varying typically from about 0.5 to about 5.0% weight. These solids consist mainly of sand and clay particles.
Another source of high solid content hydrocarbonaceous fuel employed in partial combustion processes is a liquid petroleum fraction containing a dispersion of coal, soot or coke. The coal may be hard coal, such as anthracite, or bituminous coal, brown coal or lignite. Such dispersions of solid particles in liquid petroleum fractions are useful fuels in partial combustion processes because it is a convenient means of pressurizing solid fuel in a reactor in order to gasify the solid and liquid fuel. The solid particles, in particular the various type of coal, typically contain ash-forming constituents.
It has now been found that employing such liquid petroluem fractions containing finely dispersed solids as feed to a partial combustion process results in the formation of deposits in the reactor, in particular on the wall opposite the fuel inlet, and in such amounts that normal operation must regularly be interrupted for removing such deposits from the reactor walls.
CONVENTIONAL OPERATION
In a typical partial combustion reactor, the oxidant-air, oxygen or a mixture of the two are introduced into the reaction chamber in such a fashion that the oxidizing gas is rotated tangentially around the injected finely dispersed fuel in order to promote the stability of the flare. See, for example, British Pat. No. 1,116,979. Further, the oxidant is given this strong rotary motion because this also promotes swirling of the reaction mixture in the reactor and consequently improves the mixing of fuel and oxidant. A result of this strong swirling action in the reactor is that the solid particles in the feed are flung against the wall of the reactor. As long as these particles are hard and non-sticky, there is little problem of deposits and accumulation. In the case of solids that are molten under the prevailing reaction conditions, there is, as a rule, also no accumulation problem, at least not for the side and top walls of the reactor, because the molten substance is fairly thin-flowing and tends to flow down the walls of the reactor. However, when non-combusted or only partly combusted oil is present in the reaction chamber, the oil acts as an adhesive, as a result of which a sticky substance with a high solids content can be deposited on the reactor wall. Although, due to the high temperature in the reactor, the hydrocarbons in the deposits are cracked and carbonized, the deposits remain on the reactor walls. Accordingly, not only ash-forming particles, such as clay, sand, etc., adhere to the reactor walls, but if the fuel contains a dispersion of coal in oil, the deposits also contain coal particles that have not yet been combusted.
Under conventional process conditions with a strong swirl, the reaction mixture in the reactor has an outward swirl in which a relatively large amount of partly combusted oil is still present, especially in the middle and upper part of the reactor where deposits can be formed. One measure in the degree of swirl within the reactor is the ratio of the axial velocity component (V ax ) of the oxidant as compared to the tangential velocity compounds (V tan ) of the oxidant as measured at the outlet of the injection device. In conventional processes the ratio of V ax to V tan is typically less than 2, resulting in such a degree of outward swirl of the reaction mixture in the reactor as to create deposits on the reactor walls.
SUMMARY OF THE INVENTION
The present invention is an improvement in the process for the partial combustion of a liquid hydrocarbon fuel containing finely dispersed solids in a substantially void reactor wherein the fuel is mixed with or finely dispersed in an oxygen-containing gas and passed as a solid-containing gaseous jet through at least one supply opening in the reactor and wherein the oxygen-containing gas is introduced into the reactor with an axial as well as tangential velocity component so as to impart a swirl to the flame, which improvement comprises maintaining the ratio of the axial velocity component (V ax ) of the oxygen-containing gas as compared to the tangential velocity component (V tan ) of the oxygen-containing gas in excess of 3.0, preferably 4 to 5.
By maintaining this relatively high ratio of V ax to V tan , the outward swirl of the fuel-oxygen mixture is greatly reduced resulting in a longer residence time for the fuel particles in the body of hot gas. In addition, the chances of contact of the uncombusted fuel with the reactor wall is decreased and the time available for oxidation has increased such that no adhesive substance is present to cause solid particles to adhere to the wall.
Also disclosed is an apparatus suitable for carrying out the process according to the invention. The apparatus comprises a substantially void reactor having an inlet device with a central tube for the supply of the fuel surrounded by an inlet channel for the oxidant, the center line of the tube and the channel coinciding with the center line of the reactor, the inlet channel being provided with a tangentially directed supply tube for the oxidant, while the ratio of the diameter of the channel for the oxidant to the diameter of the output opening of that channel is at least 3. Thus, the oxidant is forced to flow through a relatively more narrow opening than found in conventional design whereby the axial component of the velocity is increased.
THE DRAWINGS
The invention is described in greater detail with reference to the accompanying drawings. These drawings which illustrate the process and apparatus of the present invention are intended to be illustrative rather than limiting on its scope.
FIG. 1 is a longitudinal section of an apparatus according to the invention.
FIG. 2 shows in more detail a longitudinal section in which such an apparatus is compared with an apparatus according to prior art.
DETAILED DESCRIPTION OF THE INVENTION
The partial combustion step of the present invention can be suitably carried out using air, oxygen-enriched air or oxygen as the oxidant source (oxygen-containing gas). In any case, it is contemplated that the reaction will be conducted under conditions of temperature and pressure such that the reaction is self-supporting. Accordingly, the reaction temperature, broadly stated, is from about 700° to about 2000°C with a reaction pressure of from atmospheric to about 600 psig. Within the broad range the reaction temperature and pressure are preferably 900°-1400°C and atmospheric to 30 psig, respectively, when air is used as the oxidant source with somewhat higher temperatures and pressures, e.g., 1100°-1700°C and atmospheric to 600 psig, being employed when oxygen is used as the source of oxygen-containing gas.
The hydrocarbonaceous fuels which are suitable for use in the process of the invention include any liquid hydrocarbon feed material containing finely dispersed solids, preferably greater than about 0.1% finely dispersed solids. Examples of suitable hydrocarbonaceous fuels include those mentioned in the section of the specification entitled Background of the Invention. Examples of liquid hydrocarbon or petroleum fractions include gasoline, kerosene, naphtha, distillates, gas oils and residual oils. A particularly preferred feed to be employed in the present invention is the petroleum fraction obtained from the processing of tar sands.
The O/C ratio (oxygen to carbon) of the total oxygen-containing gas and hydrocarbonaceous fuel feedstock introduced into the partial combustion reaction zone may suitably vary between about 0.8 and about 2.0 with ratios in the range of 0.8 to about 1.2 being preferred.
Certain benefits, such as reduced soot make, are also realized in the process when steam is introduced into the reactor with either or both of the hydrocarbon fuel and/or oxygen-containing gas feedstock to the partial combustion reactor. Thus, in an optional embodiment of the invention, the oxygen-containing gas, the hydrocarbonaceous fuel or the oxygen-containing gas/hydrocarbonaceous fuel admixture may be mixed with steam or passage into the partial combustion reactor. Additionally, either or both of the hydrocarbonaceous fuel and oxygen-containing gas feedstreams may be subject to preheating via external heat exchange prior to introduction into the partial combustion reactor.
The apparatus suitable for carrying out the process according to the invention comprises a substantially void reactor having an inlet device with a central tube for the supply of the fuel surrounded by an inlet channel for the oxygen-containing gas, the center lines of the tube and the channel coinciding with the center line of the reactor, the inlet channel being provided with a tangentially directed supply tube for the oxygen-containing gas, while the ratio of the diameter of the channel for the oxidant to the diameter of the outlet opening of that channel is at least 3.
If desired, it is possible to adapt an inlet device of current dimensions suitable for the gasification of oil to the gasification of liquid hydrocarbons containing finely dispersed solids. This may be done by applying a thin coating of a suitable metal, e.g., steel, to the inside of the channel for the oxidant near the outlet opening.
According to the present invention, a reactor with a conventional length to width ratio of about 2 to 3 gives excellent performance. If desired, a reactor with a larger length to width ratio may be employed and be adapted to the length of the flame.
If only one supply device is present, the center line of it preferably coincides with the center line of the reactor. If a plurality of supply devices are present, they are preferably arranged in a regular array relative to the center line of the reactor, the distance between any two supply devices being at least 10 times as large as the diameter of the outlet of the supply device and the diameter of the reactor being so large that the distance between the wall of the reactor and the nearest supply device is at least five times as large the diameter of the outlet of the supply device.
The invention is further illustrated by means of reference to the figures and an illustrative embodiment. Note that the figures and illustrative embodiment are given for the purpose of illustration only and that the invention is not to be regarded as limited to any of the specific conditions or reactants recited therein.
DETAILED DESCRIPTION OF THE DRAWINGS
Referring to FIG. 1, only a small portion of the reactor wall, indicated by 1, is shown. The inlet device 2 contains a central pipe or tube 3 for supply of the liquid hydrocarbon feed which liquid feed contains finely dispersed solids. This central tube 3 is surrounded by a channel 4 for the oxygen-containing gas, which gas may or may not be mixed with steam. The channel 4 is connected to a tangentially directed oxidant supply tube 5 such that the oxidant from supply tube 5 rotates around fuel tube 3 in the direction of outlet 6. The ratio of the diameter D of channel 4 to diameter d of outlet 6 is significant since as this ratio is increased, the gaseous oxidant-fuel mixture will enter the reaction chamber with a larger axial component of the velocity. A typical ratio of D to d according to the present invention is about 4.5 as compared to a value of less than about 3 for a conventional design. The inlet device is furthermore provided with a water jacket 7 having an inlet 8 and outlet 9 for the circulating cooling water.
FIG. 2 indicates how a conventional inlet device may be adapted for use in the present invention. The lefthand side of FIG. 2 shows a conventional inlet device whereas the righthand side shows a conventional inlet device modified for use in the present invention. D 1 , D 2 , d 1 and d 2 denote the diameters in accordance with D and d of FIG. 1. Parts 10 and 11 have the same dimensions and diameter D 1 equals diameter D 2 . It has been shown in FIG. 2 that by applying a coating 12 of a suitable steel and by a minor modification of the lining 13 of the nozzle of the inlet device, that diameter d 2 has been made smaller than diameter d 1 and consequently D 2 /d.sub. 2 < D 1 /d 1 .
ILLUSTRATIVE EMBODIMENT I
A series of runs were carried out in a semi-commercial installation, each with a running time of between 18 and 24 hours. The runs were carried out with a heavy oil originating from a tar sand deposit. In runs 1-5, the oil had an ash content of 0.64%w while in run 6 the ash content was 2.1%w. Gasification was conducted with air preheated to 400°-500°C and feed preheated to 160°-170°C. The pressure in the reactor was 16-17 bar. The results of the run, including the additional process conditions are given below in Table I. V ax and V tan are the velocity components of the air alone as measured at the outlet of the supply device (comparable to opening 6 of FIG. 1). "Ash retention" is the difference between the amount of ash introduced into the reactor with the fuel and the amount of ash leaving the reactor with the gas, expressed as a percentage of the ash present in the feed. After run 3, a 25 mm thick layer of porous ash was found to be adhering to the top and to the side wall down to about the middle of the reactor. The temperature in the reactor was invariably lower than the melting point of the ash present in the feed (about 1320°C).
Table I______________________________________Run Feed Oxygen Steam Temp. Ash V.sub.ax AshNo. kg/h Nm.sup.3 /kg kg/kg °C supply V.sub.tan reten- feed feed kg/h tion %______________________________________1 174 0.85 0.50 1260 1.11 1.9 422 171 0.85 1.49 1173 1.09 1.9 363 146 0.95 0.00 1179 0.93 1.9 924 163 0.69 1.03 1177 1.04 4.3 75 159 0.70 0.48 1225 1.02 4.3 136 167 0.63 0.91 1290 3.52 4.3 0______________________________________
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A process for the gasification of oil containing finely dispersed solids, e.g., oil from tar sands, by partial combustion in a hollow reactor is disclosed in which process the gaseous oxidant is introduced into the reactor under flow conditions characterized by a relatively large axial velocity component as compared with the tangential flow component resulting in a relatively long flame.
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This application is a continuation of PCT/CA99/00227 filed Mar. 16, 1999 designating the United States and claiming priority of Canadian Patent Application Serial Number 2,232,536 filed Mar. 19, 1998.
BACKGROUND OF THE INVENTION
(a) Field of the Invention
The invention relates to the use of Saccharomyces cerevisiae highly related mannosyltransferases encoding genes that, when inhibited, cause lethality of the yeast cell and to a novel cell-based antifungal screening assay.
(b) Description of Prior Art
Fungi constitute a vital part of our ecosystem but once they penetrate the human body and start spreading they cause an infection or "mycosis" and they can pose a serious threat to human health. Fungal infections have dramatically increased in the last two (2) decades with the development of more sophisticated medical interventions and are becoming a significant cause of morbidity and mortality. Infections due to pathogenic fungi are frequently acquired by debilitated patients with depressed cell-mediated immunity such as those with HIV and now also constitute a common complication of many medical and surgical therapies. Risk factors that predispose individuals to the development of mycosis include neutropenia, use of immunosuppressive agents at the time of organ transplants, intensive chemotherapy and irradiation for hematopoietic malignancies or solid tumors, use of corticosteroids, extensive surgery and prosthetic devices, indwelling venous catheters, hyperalimentation and intravenous drug use, and when the delicate balance of the normal flora is altered through antimicrobial therapy.
The yeast genus Candida constitutes one of the major groups that cause systemic fungal infections and the five medically relevant species which are most often recovered from patients are C. albicans, C. tropicalis, C. glabrata, C. parapsilosis and C. krusei.
Much of the structure of fungal and animal cells along with their physiology and metabolism is highly conserved. This conservation in cellular function has made it difficult to find agents that selectively discriminate between pathogenic fungi and their human hosts, in the way that antibiotics do between bacteria and man. Because of this, the common antifungal drugs, like amphotericin B and the azole-based compounds are often of limited efficacy and are frequently highly toxic. In spite of these drawbacks, early initiation of antifungal therapy is crucial in increasing the survival rate of patients with disseminated candidiasis. Moreover, resistance to antifungal drugs is becoming more and more prominent. For example, 6 years after the introduction of fluconazole, an alarming proportion of Candida strains isolated from infected patients have been found to be resistant to this drug and this is especially the case with vaginal infections. There is thus, a real and urgent need for specific antifungal drugs to treat mycosis.
The fungal cell wall: a resource for new antifungal targets
In recent years, we have focused our attention on the fungal extracellular matrix, where the cell wall constitutes an essential, fungi-specific organelle that is absent from human/mammalian cells, and hence offers an excellent potential target for specific antifungal antibiotics. The cell wall of fungi is essential not only in maintaining the osmotic integrity of the fungal cell but also in cell growth, division and morphology. The cell wall contains a range of polysaccharide polymers, including chitin, β-glucans and O-Serine/Threonine-linked mannose sidechains of glycoproteins. β-glucans, homopolymers of glucose, are the main structural component of yeast cell wall, and constitute up to 60% of the dry weight of the cell wall. Based on their chemical linkage, two different types of polymers can be found: β1,3-glucan and β1,6-glucan.
Mannoproteins are an intrinsic part of the cell wall where they are intercalated in the meshwork of the glucose and chitin polymers and the attachment of mannose to cell surface proteins is a process essential for fungal viability. A great variety of cell surface mannoproteins are cross-linked through disulfide bounds or linked to cell wall polymers through glycosidic bonds. Many of these cell wall glycoproteins are of unknown function and do not appear to possess any enzymatic activity, but likely have structural roles in cell wall architecture and integrity.
It would be highly desirable to be provided with the identification and subsequent validation of new cell wall related targets that can be used in specific enzymatic and cellular assays leading to the discovery of new clinically useful antifungal compounds.
SUMMARY OF THE INVENTION
One aim of the present invention is to provide the identification and subsequent validation of a new target that can be used in specific enzymatic and cellular assays leading to the discovery of new clinically useful antifungal compounds.
In the yeast Saccharomyces cerevisiae, we have identified highly related mannosyltransferases encoding genes that, when inhibited, cause lethality of the yeast cell. These enzymes are not found in human cells as they participate in the synthesis of fungal-specific structures (O- and N- mannosyl chains in the cell wall).
The essential nature of these enzymes will serve as the basis of different screens for novel antifungal compounds.
The yeast Saccharomyces cerevisiae, although not a pathogen, is the proven model organism for pathogenic fungi as it is closely related taxonomically to the opportunistic pathogens and genes highly homologous to the different members of the S. cerevisiae mannosyltransferase family have been found in Candida albicans.
It can be presumed that these mannosyl transferases are also essential in C. albicans.
In accordance with the present invention there is provided antifungal screening assays for identifying compounds which inhibit mannosyltransferases involved in protein O- and N-glycosylation, which comprises the steps of:
a) subjecting specific mannosyltransferase protein encoded by a Saccharomyces cerevisiae mannosyltransferase encoding gene, wherein said gene is selected from the group consisting of KRE2/MNT1, YUR1, KTR1, KTR2, KTR3, KTR4, KTR5, KTR6 and KTR7;
b) subjecting step a) to a screened compound and determining absence or presence on proteins of specific O- and N-linked oligosaccharides, wherein absence of these glycans is indicative of an antifungal compound.
In accordance with the present invention there is also provided an in vivo antifungal screening assay for identifying compounds which inhibit mannosyltransferase involved in protein O- and N-glycosylation, which comprises the steps of:
a) separately cultivating a mutant yeast strain lacking at least one gene for synthesis of mannosyltransferase and a control yeast strain containing said at least one gene;
b) subjecting said both yeast strains of step a) to screened compound and determining if said compound selectively inhibits growth of a wild type strain which is indicative of an antifungal compound.
The gene used in accordance with this method may be selected from the group consisting of KRE2/MNT1, YUR1, KTR1, KTR2, KTR3, KTR4, KTR5, KTR6 and KTR7.
The mutants with defects (null or defective alleles) in one or more of the KTR genes can be examined for altered patterns of transcription of all yeast genes, by hybridizing to whole yeast genome array. These altered patterns of gene transcripts when compared to the wild type strain can be used to generate a profile or fingerprinting of the defects caused by the KTR mutations. This fingerprinting can be used to generate a diagnostic set of reporter genes regulated by the promoter and upstream elements of the relevant regulated genes. This diagnostic set of reporter genes can then be placed into yeast strains and subjected to inhibitory compounds to form a screen for compounds that elicit a reporter response equivalent to that generated by KTR defects in the mutant strains. Such compounds are candidates for inhibitors of the Ktrp proteins and hence candidates for specific antifungal inhibitors.
In accordance with the present invention there is also provided an in vivo antifungal screening assay for identifying compounds that elicit a reporter response equivalent to that generated by KTR defects in the mutant strains, which comprises the steps of:
a) cultivating yeast strains having a diagnostic set of reporter genes of defects caused by KTR mutations; and
b) subjecting said yeast strains of step a) to screened compound and determining if said compound selectively inhibit growth of wild type strain which is indicative of a compound being a candidate for inhibitors of the Ktrp proteins and/or a candidate for specific antifungal inhibitors.
In accordance with the present invention there is also provided an in vitro method for the diagnosis of diseases caused by fungal infection in a patient, which comprises the steps of:
a) obtaining a biological sample from said patient;
b) subjecting said sample to PCR using a primer pair specific for a mannosyltransferase gene of Candida albicans homolog to a gene selected from the group consisting of KRE2/MNT1, YUR1, KTR1, KTR2, KTR3, KTR4, KTR5, KTR6 and KTR7, wherein a presence of said gene is indicative of the presence of fungal infection, such as a fungal infection caused by Candida.
In accordance with the present invention there is also provided an in vitro method for the diagnosis of diseases caused by fungal infection in a patient, which comprises the steps of:
a) obtaining a biological sample from said patient;
b) subjecting said sample to an antibody specific for a specific Ktrp mannosyltransferase antigen, wherein a presence of said antigen is indicative of the presence of fungal infection, such as a fungal infection caused by Candida.
In accordance with the present invention there is also provided the use of at least one of the Saccharomyces cerevisiae mannosyltransferase gene selected from the group consisting of KRE2/HNT1, YUR1, KTR1, KTR2, KTR3, KTR4, KTR5, KTR6 and KTR7 and fragments thereof as a probe for the isolation of homologs in other species.
BRIEF DESCRIPTION OF THE DRAWING
FIG. 1 illustrates the relational homology tree of mannosyltransferase catalytic domains of the Ktrp family.
DETAILED DESCRIPTION OF THE INVENTION
In the Bussey laboratory at McGill, we work on several aspects of cell wall and glycoprotein synthesis. These studies have lead to the identification and subsequent validation of new targets that can be used in specific enzymatic and cellular assays leading to the discovery of new clinically useful antifungal compounds.
We have been studying at length the nine-membered KTR mannosyltransferase gene family of which some members have been shown to encode enzymes that are involved in the elaboration of O- and N-linked oligosaccharides of extracellular matrix proteins including those of the cell wall. The yeast complete genome sequence has revealed that the KTR gene family consists of the KRE2/MNT1, YUR1, KTR1, KTR2, KTR3, KTR4, KTR5, KTR6 and KTR7 genes (Lussier, M. et al., Yeast 13:267-274, 1997). As with other known glycosyltransferases, all genes in this family are predicted, and some have been shown, to encode type-II membrane proteins with a short cytoplasmic N-terminus, a membrane-spanning region, and a highly conserved catalytic lumenal domain.
Similarity between different family members is variable and ranges from 62% identity between Yur1p and Ktr2p to 24% identity for Ktr5p and Ktr6p which constitute the 2 most divergent enzymes in the family. A relational homology tree constructed using the catalytic domains of all proteins of the family has allowed grouping of the different enzymes (FIG. 1). The tree shows for example that Kre2p is most related to Ktr1p and Ktr3p, that Yur1p and Ktr2p form a subfamily as do Ktr5p and Ktr7p . In contrast, Ktr4p and Ktr6p are not closely related to each other or to any other members of the family and may play distinct roles.
The KRE2/MNT1 gene was the first member of the family to be isolated as a gene implicated in cell wall assembly conferring K1 killer toxin resistance when mutated and found to encode a medial Golgi α1,α2-mannosyltransferase. Kre2p/Mnt1p along with Ktr1p and Ktr3p have overlapping roles and collectively add most of the second and the third α1,2-linked mannose residues on O-linked oligosaccharides and are also jointly involved in N-linked glycosylation, possibly in establishing some of the outer chain α1,2-linkages (Lussier, M. et al., J. Biol. Chem. 272:15527-15531, 1997). Initial functional characterization of Yur1p and Ktr2p has revealed that they are Golgi mannosyltransferases involved in N-linked glycosylation, possibly as redundant enzymes but when inactivated show no defects in O-linked glycosylation (Lussier, M. et al., J. of Biol. Chem., 271:11001.-11008, 1996. Finally, it has been recently shown that KTR6/MNN6 encodes a phosphomannosyltransferase modifying N-linked outer chains.
Multiple disruptions of KTR family members cause lethality
To explore functional relationships between the different family members of the upper branches of the relational homology tree (FIG. 1) and more closely so examine their role and essentiality, yeast strains bearing mutations in the KTR1, KTR3, KRE2, YUR1 and KTR2 genes were investigated for lethality.
Experimental strategy:
Lethality of a ktr1 ktr3 yur1 ktr2 quadruple disruptant was demonstrated by crossing both ktr1::LYS2 ktr2::URA3 ktr3::HIS3 (Mata) and ktr1::LYS2 ktr2::URA3 yurl::HIS3 (Mat∝) triple disruptants, sporulating the resulting diploid and analyzing the independent assortment of the ktr3::HIS3 and yur1::HIS3 alleles in the spore progeny. All resulting spores carry inactivated copies of their KTR1 and KTR2 gene (ktrl::LYS2 ktr2::URA3).
TABLE 1______________________________________The three classes of tetrads produced in the cross Parental Ditype Non Parental Ditype Tetratype______________________________________2 spores: yur1::HIS3 2 spores: yur1::HIS3 1 spore: YUR1 KTR3 ktr3::HIS3 KTR3 (AB- SENT) 2 spores: ktr3::HIS3 2 spores: YUR1 1 spore: yur1::HIS3 YURI KTR3 KTR3 1 spore: ktr3::HIS3 YUR1 1 spore: yur1::HIS3 ktr3::HIS3 (ABSENT) 6 tetrads of this 7 tetrads of this type 28 tetrads of this type type in total. in total. 2:2 lethality. in total. Of the 3 All 4 spores are viable The 2 living spores viable spores, 2 are and His.sup.+ are His.sup.- His.sup.+______________________________________
Results
Deletional disruptions of the KTR1, KTR3, KRE2, YUR1 and KTR2 genes were previously obtained, and no single, double or triple disruptants were found to be lethal whereas a strain in which all five genes of this subfamily were inactivated was found to not be able to grow. A remaining question was to see whether any of the four possible quadruple disruptants resulting from different permutation of knockouts would cause death. Using standard genetic techniques ktr1 kre2 yur1 ktr2, ktr3 kre2 yur1 ktr2, ktr1 ktr3 kre2 yur1 quadruple disruptants were obtained and thus shown to be viable while a ktr1 ktr3 yur1 ktr2 disruptant could not be obtained, demonstrating the essential nature of these 4 enzymes (Table 1).
Discussion
Studying the roles of the KTR gene family has proven informative both for the analysis of the enzymes that are involved in protein O- and N-glycosylation, and also to offer insights into the biological reasons that allow such diversity of related gene products to occur. The minimal combination of genes that when inactivated cause lethality represents the 2 most homologous gene pair in the family. When only one of these 4 genes, namely KTR1, KTR2, KTR3 or YUR1, has not been inactivated in the collection of all possible quadruple disruptions, the yeast cell grows slowly suggesting that when both members of one gene pair are missing, members of the other subfamily may be partially able to functionally substitute for the missing enzymes or that inactivation of gene pairs cause different cellular defects and it is a combination of these that cause lethality.
The precise reasons why the ktr1 ktr3 yur1 ktr2 quadruple disruptant is unable to survive remain to be determined but these results again corroborate that glycosylation is an essential process in yeast. The fact that the lethality of the quadruple knock out can be moderately circumvented by growth on the osmotic stabilizer sorbitol suggest that some cell wall defects are at the source of the lethality in normal growth conditions.
Finally, these results indicate that the enzymes situated in the upper part of the relational homology tree form a functional subfamily that have highly similar roles which are very distinct from those enzymes situated in the bottom part of the tree since the presence in the genome of active copies of KTR4, KTR5, KTR6 and KTR7 cannot rescue the quadruple disruptant from death. The highly related Ktr1p, Ktr2p, Ktr3p and Yur1p enzymes can thus serve as the basis of an enzymatic screen for novel antifungal drugs since the similarity in their functioning imply that a specific compound could inhibit all of them at once and consequently kill the yeast cells.
The present invention will be more readily understood by referring to the following examples which are given to illustrate the invention rather than to limit its scope.
EXAMPLE I
In Vitro Screening Method for Specific Antifungal Agents (Enzymatic-Based Assay)
The broad aim is to identify novel compounds that inhibit the α1,2-mannosyltransferase activities that are singly or collectively shared by Ktr1p, Ktr3p, Yur1p and Ktr2p. This task can be accomplished by existing methodologies such as the production of large amounts of each protein and by the availability of genetic tools, such as the ability to delete or overexpress gene products involved in protein glycosylation. Such assays will permit the screening of possible compounds that inhibit specific steps in the synthesis of O- and N-linked oligosaccharides, resulting in lethality or diminished virulence of the yeast cell. When such inhibitors are found, they can be evaluated as candidates for specific antifungal agents.
EXAMPLE II
Use of Ktr1p, Ktr3p, Yur1p and Ktr2p in an In Vivo Screening Method for Specific Antifungal Agents (Cellular-Based Assay)
Antifungal drug screens based on whole-cell assays in which members of the KTR family would be targeted. For example, a quadruple null mutant containing a specific Ktrp Candida albicans homolog or a KTR S. cerevisiae thermosensitive allele can be constructed permitting a specific screen in which compounds could be tested for their ability to inhibit growth or kill such a strain while having no effect on a control strain. The direct scoring on cells of the level of efficacy of a particular compound alleviates the costly and labor intensive establishment of an in vitro enzymatic assay. The availability of genetic tools, such as the ability to delete or overexpress the identified gene products permits the establishment of this new screening method. When such inhibitors are found, they can be evaluated as candidates for specific antifungal agents.
EXAMPLE III
Use of the Essential Nature of the KTR Family in All Fungi
Isolation and use of functional homologs of Ktr1p, Ktr3p, Yur1p and Ktr2p family members from all fungi. All known fungi possess mannoproteins and likely have KTR homologs in their genomes. Specific ktr mutants allow isolation of similar genes from other pathogenic fungi by functional complementation. All KTR genes can also serve as probes to isolate by homology KTR homologs from other yeasts. In addition, Ktrp allows isolation of homologs in other species by the techniques of reverse genetics where antibodies raised against any Ktrp family members could be used to screen expression libraries of pathogenic fungi for expression of KTR homologs that would immunologically cross react with antibodies raised against S. cerevisiae KRE2, YUR1, KTR1-7.
While the invention has been described in connection with specific embodiments thereof, it will be understood that it is capable of further modifications and this application is intended to cover any variations, uses, or adaptations of the invention following, in general, the principles of the invention and including such departures from the present disclosure as come within known or customary practice within the art to which the invention pertains and as may be applied to the essential features hereinbefore set forth, and as follows in the scope of the appended claims.
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The present invention relates to an antifungal in vitro and in vivo screening assays for identifying compounds which inhibit mannosyltransferases involved in protein O- and N-glycosylation. The antifungal screening assay for identifying a compound which inhibit mannosyltransferases involved in protein O- and N-glycosylation, comprises the steps of: a) subjecting proteins to a specific mannosyltransferase protein encoded by a Saccharomyces cerevisiae mannosyltransferase encoding gene, wherein said gene is selected from the group consisting of KRE2/MNT1, YUR1, KTR1, KTR2, KTR3, KTR4, KTR5, KTR6 and KTR7; b) subjecting step a) to a screened compound and determining the absence or presence of protein O- and N-glycosylation, wherein the absence of protein O- and N-glycosylation is indicative of an antifungal compound. There is also disclosed an in vitro method for the diagnosis of diseases caused by fungal infection in a patient.
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BACKGROUND OF THE INVENTION
The present invention relates to method of automatically removing fully wound bobbin tubes and replacing them with empty bobbin tubes in a textile spinning machine of the type having a plurality of spinning stations, each of which includes a yarn drafting system, a spindle for receiving a bobbin tube and a funnel coaxial with and extending over the spindle for applying yarn from the drafting system for winding about the bobbin tube.
Textile spinning machines of the aforementioned type provide the advantage of being capable of operation at approximately three times the production speed of ring spinning machines. As a natural result, the bobbin tubes about which the spun yarn is wound become fully wound in a correspondingly more rapid manner than in ring spinning machines and, in turn, the bobbin tubes must be exchanged more frequently.
Accordingly, a need exists for a method of exchanging fully wound bobbin tubes with empty bobbin tubes in such funnel-type spinning machines in a rapid and reliable manner utilizing an exchange mechnism of simple contruction.
SUMMARY OF THE INVENTION
Briefly summarized, the present invention provides such a bobbin exchange method by performing the basic steps of initially interrupting spinning operation of the spinning machine while maintaining unbroken the several yarns being simultaneously spun and the separating the spindles and the funnels from one another in an axial direction followed by separating the spindles and funnels from one another in a radial direction. The fully wound bobbin tubes are then removed from the spindles and empty bobbin tubes are placed on the spindles while still maintaining the yarns unbroken. The years are engaged with the empty bobbin tubes in the area of the spindles and then the yarns are severed between the removed fully wound bobbin tubes and the empty bobbin tubes. After the spindles and funnels are repositioned in relative spinning disposition with each funnel coaxial with and extending over the respectively associated spindle, the spinning operation is resumed.
A rapid and reliable exchange of the spinning bobbins can be performed according to the method of this invention. The connection of the yarns between the fully-wound spinning bobbins and the respectively associated drafting systems is preserved initially by means of the funnels and then later the yarn ends are automatically connected to the empty replacement bobbin tubes, such that the present method may be readily incorporated into the control program of a spinning machine.
According to a further aspect of the present invention, the yarns are clamped on the spindles when the empty bobbin tubes are placed thereon. Thus, it is unnecessary to provide special yarn holding or yarn catching devices to secure the yarn ends in position.
It is preferred in the performance of the method of the present invention that the spindles and the funnels execute only one of their relative movements at a time, i.e. relative axial movement or relative radial movement. This results in a clear division of the associated drives. Since relative movement between the funnel and the spindle is necessary in any event as a part of the normal bobbin winding process, it is advantageous if the movable element, normally the spindle, is utilized to execute the separating movement in advance of the doffing operation in the present method. It is additionally advantageous that the relative radial separation of the spindles and the funnels be preformed by moving the funnels toward a central area of the spinning machine where sufficient space is available to accommodate this movement.
Preferably, a reserve extent of each yarn is formed in the area between each fully wound bobbin tube and the respectively associated drafting system in order to accommodate clamping of the yarns as aforementioned or possibly underwinding of the yarns on the respective fully wound bobbin tubes. The reserve yarn extents may be formed after the interruption of the spinning operation by pulling a portion of each yarn off its fully wound bobbin tube. Alternatively, the reserve yarn extents may be formed in advance of the spinning interruption. Upon resumption of the spinning operation, the remainder of each reserve yarn extent is released and wound onto the respectively associated empty bobbin tube.
To accommodate one possible embodiment of the present method, a pair of receptacles adapted for holding bobbin tubes is mounted in association with each funnel and an empty bobbin tube is retained by a first receptacle of each receptacle pair. When the spindles and funnels are radially separated, the second receptacle of each receptacle pair is positioned in axial alignment with the respectively associated spindle. To remove the fully wound bobbin tubes, the spindles and the associated second receptacles are moved axially toward one another to engage and retain the fully wound bobbin tubes on the spindles by the associated second receptacles, following which the spindles and the associated second receptacles are axially separated to remove the fully wound bobbin tubes from the spindles. To then place the empty bobbin tubes on the spindles, the first receptacle of each receptacle pair is positioned in axial alignment with the respectively associated spindle and the spindles and associated first receptacles are moved axially toward one another to dispose the empty bobbin tubes retained by the first receptacles on the respectively associated spindles. The empty bobbin tubes are then released from the first receptacles and the spindles and the associated first receptacles are axially separated from one another. Thereafter, the funnels are again positioned in coaxial spinning disposition over the respectively associated spindles and the spinning operation is resumed. Preferably, the fully wound bobbin tubes are removed from the second receptacles after the spinning operation has been resumed.
In this embodiment, after the fully wound bobbin tubes have been removed from spindles and before the spindles and the first receptacles are moved toward one another, an extent of each yarn trailing from the associated fully wound bobbin tube is placed transversely over an end of the associated empty bobbin tube facing the associated spindle. Each of the first and second receptacles of each receptacle pair are preferably constructed for gripping an outwardmost end of each bobbin tube facing away from the spindles to facilitate the steps of retaining the empty and fully wound bobbin tubes.
In this embodiment of the present method, the movements required for exchange of full and empty bobbin tubes are advantageously limted to a minimum. The empty replacement bobbin tubes are already held by the receptacles associated with each spinning funnel to be ready for the exchange operation and, during the performance of the actual exchange, the full bobbin tubes, once removed from the spindles, need not be transported completely away from the area of the spindles. Once the exchange is completed, the spinning operation can be immediately resumed and thereafter the fully wound bobbin tubes can be removed from the receptacles and a new set of empty replacement bobbin tubes introduced to the receptacles in preparation for the next exchange operation.
BRIEF DESCRIPTION OF THE DRAWINGS
FIGS. 1-7 are side elevational views of an individual spinning station in a spinning machine having a plurality of such spinning stations, illustrating sequential stages in a first embodiment of the bobbin tube exchange method of the present invention; and
FIGS. 8-16 are similar side elevational view of an individual spinning station showing sequential stages in the performance of another embodiment of bobbin tube exchange operation according to the present method.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring now to the accompanying drawings, each drawing illustrates a single spinning station of a textile spinning machine of the type having a plurality of adjacent spinning stations linearly aligned in a row along the spinning machine, preferably at both opposite longitudinal sides of the machines. Each spinning station includes a drafting mechanism, broadly indicated at 1, to which a roving is fed from a roving bobbin or other suitable supply (not shown), the drafting mechanism operating to draw the roving to a predetermined extent to produce a yarn of a desired fineness. Each spinning station additionally is provided with an upright spindle 3 driven by an individual drive motor 4. A bobbin tube is coaxially supported on the spindle 3 for winding of the spun yarn peripherally about the bobbin tube, the composite package of the wound yarn and the supporting bobbin tube commonly being known as a bobbin, indicated by the reference numeral 5. The spun yarn is fed progressively to the bobbin 5 via a generally conical funnel member 2, commonly referred to as a bell, positioned coaxially to the spindle 3 and extending over the spindle 3 and the supported bobbin 5 during the normal spinning operation. The funnel 2 is provided with an axial yarn inlet at its upper end coaxial with the spindle 3 to serve as a guide conduit for the spun yarn. Another conduit section extends radially outwardly from the axial yarn guide conduit, normally at an inclination in the direction of yarn travel, and opens to the outer periphery of the funnel 2. Thus, the spun yarn enters the funnel 2 axially through the axial yarn guide conduit, moves radially outwardly therefrom through the radial conduit section, then travels downwardly in a helical manner along the outer periphery of the funnel 2 and is directed about the lowermost edge of the funnel onto the bobbin 5 of winding thereabout.
The funnel 2 is normally mounted in a freely rotatable manner so that the funnel 2 rotates in response to the helical traveling movement of the yarn along the outer funnel periphery. However, it is also possible to positively drive and/or brake the funnel, as necessary or desirable.
The spun yarn of the bobbin 5 is wound in a so-called cop build-up pattern onto the bobbin tube which is set coaxially on the spindle 3. For this purpose, an appropriate relative movement of the spindle 3 and the funnel 2 axially with respect to one another is carried out over the course of the bobbin winding operation to apply the spun yarn to the bobbin 5 in a vertically reciprocating back-and-forth motion which gradually shifts to the upper end of the bobbin. In the embodiment shown, the vertical back-and-forth motion is accomplished by alternately raising and lowering the spindle 3 together with its drive motor 4 relative to the funnel 2.
When the bobbin 5 has been wound with yarn to its full capacity, the bobbin 5 and the funnel 2 will be in the relative positions shown in FIG. 1. At this point, the spinning operation is interrupted so that a bobbin exchange operation can be initiated. For this purpose, the spindles 3 and the funnels 2 are initially moved away from one another in an axial direction, preferably by lowering the spindles 3 relative to the funnels 2, to a sufficient extent that the upper ends of the bobbins 5 are spaced below the lower edges of the respective funnels 2, as shown in FIG. 2. In doing so, a corresponding length of the yarn is pulled off each bobbin 5 so that no breakage of the yarn occurs (FIG. 2). The funnels 2 and their holders 10 are then shifted as a unit radially with respect to the spindles 3 inwardly toward the central area of the spinning machine, as shown in FIG. 3. At the same time, a yarn engaging element 6, which for example may be a bent wire member formed in an inverted V-shape, is moved into contact with the portion of each yarn extending between the associated bobbin 5 and funnel 2. The yarn engaging element 6 is then moved obliquely downwardly and inwardly toward the central area of the spinning machine as indicated by the directional arrow in FIG. 3 until the element 6 reaches a final resting disposition approximately horizontally adjacent the lower ends of the supporting tubes of the bobbins 5 slightly above a shoulder portion on which each bobbin tube rests on the associated spindle 3 and on which an empty replacement bobbin tube will subsequently be rested. (See FIG. 4).
A conveyor belt or other suitable bobbin tube transport device, representatively indicated at 7, extends along each side of the spinning machine and is provided at regular intervals with upwardly projecting bobbin tube support pins. Empty replacement bobbin tubes 9 are placed on alternate ones of the support pins with the intervening pins being left free. A suitable bobbin gripping transfer device is moved into position for grasping the fully wound bobbins 5 in the position of FIG. 3 and is then moved to remove the bobbins 5 from the spindles 3 and to deposit the bobbins 5 on the free pins of the transport conveyor 7, as representatively shown in FIG. 4. A known type of such transfer device 8 suitable for this purpose is utilized in conventional ring spinning machines. During this operation, the extent of the yarns between the drafting system 1 and the bobbins 5 remains uninterrupted and unbroken. The extent of the yarns extending from the lower edge of the funnels 2, about the yarn guide element 6 and to the upper end of the bobbins 5 on the conveyor 7 forms a reserve of each yarn, as shown in FIG. 4.
Once the removed bobbins 5 have been placed on the conveyor 7, it is then moved an incremental distance equivalent to the spacing between adjacent spindles, whereby the yarns are deflected somewhat from the spindle 3 to be located in a defined position relative thereto without breaking the yarns. The transfer device 8 is then operated to remove the empty bobbin tubes 9 from the conveyor 7 and to place each tube 9 coaxially on a respective spindle 3, as shown in FIG. 5. In doing so, the extent of each yarn between the yarn engaging element 6 and the upper end of the respective bobbin 5 just removed is clamped securely on the respective spindle 3 by the lower end of the replacement bobbin tube 9. Each yarn is then severed along its extent between the empty bobbin tube 9 and the removed bobbin 5 by a suitable cutting device, shown only schematically in FIGS. 5 at 17, after which the full bobbins 5 can be transported away from the spinning machine by the conveyor 7.
A new empty replacement bobbin tube 9 having been placed onto each spindle 3, the drive motors 4 of the spindles 3 are reactivated and, simultaneously, the yarn engagement elements 6 are withdrawn away from the area of the spinning stations, as represented by the directional arrows in FIG. 6. The spindle 3 and its motor 4 is then moved upwardly to extend coaxially into the funnel 2 and the drafting system 1 is also reactivated, thereby resuming the spinning operation with the spun yarn traveling helically along the outer periphery of the funnel 2 for winding application about the empty bobbin tube 9, all as representatively shown in FIG. 7. In normal fashion, the spindle 3 is moved vertically back-and-forth with respect to the funnel 2 to build the wound yarn on the bobbin tube 9 in the desired aforementioned fashion, while the funnel 2 rotates only in response to the traveling movement of the yarn.
FIGS. 8-16 depict another embodiment of the bobbin exchange method of the present invention. Since the individual spinning positions of the spinning machine in such embodiment do not differ in principle from the spinning positions of the above-described embodiment of FIGS. 1-7, the corresponding elements in FIGS. 8-16 are identified by the same reference numerals. In this embodiment, each spinning position differs only in that the holders 11 for the funnnels 2 are provided with a pair of receptacles 12, 13 for each spinning station. An empty bobbin tube 9 is held by each receptacle 13 immediately adjacent to the associated funnel 2 for the respective spinning station. After the bobbin 5 in spinning operation is wound to its fully capacity, the spinning operation is stopped with the funnel 2, the spindle 3 and the bobbin 5 at each spinning station in the relative dispositions shown in FIG. 8. The funnel 2 and the spindle 3 are separated axially from one another by lowering the spindle 3 and its motor 4 to a spacing below the lower edge of the funnel 2, as shown in FIG. 9. A yarn engaging element 14 located between the drafting system 1 and the upper yarn inlet side of the funnels 2 is then moved outwardly away from the spinning machine obliquely with respect to the travel path of the yarns to engage and pull a portion of each yarn off its associated full bobbin 5, forming a reserve extent of each yarn in the area between the drafting systems 1 and the funnels 2, as shown in FIG. 10. Either during or after this formation of the reserve extent of the yarns, the holders 11 of the funnels 2 are moved radially with respect to the spindles 3 in the direction inwardly toward the central area of the spinning machine until the free receptacle 12 of each holder 11 is located vertically above the respective spindle 3, as shown in FIG. 11. In doing so, each yarn is pulled from its helical disposition on the outer periphery of its funnel 2. The spindles 3 are next raised until the upper end of the bobbin tube of each full bobbin 5 is engaged with the associated free receptacle 12 positioned thereabove, as shown in FIG. 12. Each receptacle 12 includes gripper elements which are configured and adapted to extend interiorly within a bobbin tube and engage behind a compatible corresponding inner annular flange of a bobbin tube so as to hold a bobbin tube securely. Accordingly, when the receptacles 12 are engaged by the upper end of the respective full bobbins 5, the receptacles 12 grip and securely retain the bobbins 5 when the spindles 3 are subsequently lowered. The gripper elements are further adapted to release a bobbin tube when the tube is raised with respect to the receptacle 12. Such gripper elements are known, for example, in holding devices for roving bobbins.
After the fully wound bobbins 5 have been engaged and gripped by the receptacles 12 to transfer the bobbins 5 to the holders 11, the spindles 3 are again lowered until they are completely free of the full bobbins 5, as shown in FIG. 13. The extent of each yarn between the upper end of its full bobbin 5 and its funnel 2 is then drawn downwardly by means of suitable guide elements, representatively indicated at 18, to dispose each yarn transversely across the lower edge of the associated empty bobbin tube held in the holder 11. The guide element 18 performing this operation may, for example, be a ring having V-shaped indentations adapted to engage the yarn. To accommodated this operation, the yarn engaging element 14 is moved in reverse toward the spinning machine to release a portion of each yarn reserve, as indicated by the directional arrow in FIG. 13.
The holders 11 are then moved radially with respect to the spindle 3 a short distance outwardly away from the central area of the spinning machine to locate the empty bobbin tubes 9 vertically above the respective spindles 3 in coaxial relation therewith. The spindles 3 are then moved upwardly to extend interiorly into the bobbin tubes 9, as shown in FIG. 14. The receptacles 13 which support the bobbin tubes 9 are of substantially the same above-described construction as the receptacles 12. Thus, the empty bobbin tubes 9 are released from the receptacles 13 to rest coaxially on the spindles 3 when the spindles 3 are raised to a sufficient extent to slightly raise the bobbin tubes 9 with respect to their receptacles 13. Upon release of the empty bobbin tubes 9 onto the spindles 3, the respective portions of the yarns extending across the lower facing edges of the bobbin tubes 9 are clamped securely between the bobbin tubes 9 and the spindles 3. Thereupon, each yarn is severed along its extent between its clamped portion and its respective full bobbin 5, after which the spindles 3 with the newly received empty bobbin tubes 9 are moved downwardly, as shown in FIG. 15. The holders 11 are then moved radially withe respect to the lowered spindles 3 into the orignal disposition (FIG. 8) wherein the funnels 2 are coaxially above the spindles 3 (FIG. 15). Once this disposition is reached, the drives 4 of the spindles 3 are reactivated while simultaneously the yarn engagement element 14 is removed to its orignal disposition out of engagement with the yarns to release the remaining yarn reserve. The spindles 3 with their empty bobbin tubes 9 are then moved upwardly to penetrate into the interior of their respectively associated funnels 2 and the drafting systems 1 are reactivated to resume normal spinning operation, as indicated in FIG. 16.
Advantageously, the completion of this described exchange of fully wound bobbins 5 with empty bobbin tubes 9 requires only a relatively short time span between the initial interruption of normal spinning operation and the resumption of spinning operation, since the individual components need be moved only very short distances no more than is absolutely necessary to execute the successive steps of the exchange operation. Moreover, the final removal of the fully wound bobbins 5 from the receptacles 12, as well as the replacement of new empty bobbin tubes 9 onto the receptacles 13 in preparation for the next succeeding exchange operation, can be conveniently performed after the spinning machine is returned to normal spinning operation in the final step of FIG. 16.
As those persons skilled in the art will understand, it is normally not readily possible in spinning machines of the type using a funnel 3 rather than a ring and traveler to position a trailing yarn underwinding in the area of the lower tube end of fully wound bobbins 5 at the completion of spinning operation. In contrast, the method of the present invention advantageously makes possible the formation of yarn underwindings utilizing the reserve extent of each yarn formed in the course of the method steps represented by FIGS. 10 and 11. For this purpose, a ring or other suitable implement (not shown) is operated coaxially about each fully wound bobbin 5 during the method interval represented by FIG. 11 to guide the trailing extent of yarn from the bobbin 5 into the area of the lower end of the bobbin tube of the bobbin 5 so that an underwinding can then be formed thereat by releasing a portion of the yarn reserve formed by the yarn engaging element 14. This may be accomplished by moving the ring coaxially along the spindle axis while the bobbins 5 are in the position of FIG. 11 or by moving the spindles 3 to deliver the bobbins 5 to a stationary ring. Once the underwinding is formed, the ring is removed (or the bobbin 5 is removed from the ring) and the bobbin exchange operation is continued in the same manner as aforedescribed, the only difference being that, instead of the yarn extending from the upper end of the full bobbins 5 to the radial opening in the funnel 2 as shown in FIG. 11, the yarn insteasd extends from the underwinding to the funnel 2. Nevertheless, this difference would not result in any basic change in the performance of the subsequent steps of the bobbin exchange operation.
It will therefore be readily understood by those persons skilled in the art that the present invention is susceptible of a broad utility and application. Many embodiments and adaptations of the present invention other than those herein described, as well as many variations, modifications and equivalent arrangements will be apparent from or reasonably suggested by the present invention and the foregoing description thereof, without departing from the substance or scope of the present invention. Accordingly, while the present invention has been described herein in detail in relation to its preferred embodiment, it is to be understood that this disclosure is only illustrative and exemplary of the present invention and is made merely for purposes of providing a full and enabling disclosure of the invention. The foregoing disclosure is not intended or to be construed to limit the present invention or otherwise to exclude any such other embodiment, adaptations, variations, modifications and equivalent arrangements, the present invention being limited only by the claims appended hereto and the equivalents thereof.
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In a spinning machine of the type having plural spinning stations each including a drafting system, a bobbin spindle and a coaxial funnel, the automatic exchange of empty bobbin tubes for fully wound bobbin tubes on the spindles is accomplished by interrupting the spinning operation without yarn breakage or severing, separating the spindles and funnels axially and radially from one another, removing the fully wound bobbin tubes and placing empty bobbin tubes on the spindles, engaging the still unbroken yarns with the empty bobbin tubes, then severing the yarns between the removed fully wound bobbin tubes and the replacement empty tubes, and repositioning the funnels and spindles and resuming spinning operation.
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BACKGROUND OF THE INVENTION
The invention relates to a process for the preparation of a starch ester of a number average molecular weight of 1000-50,000 and a degree of substitution of 0.4-3.0 by esterification of a starch with one or more monocarboxylic acids. By starch is to be understood here a starch which may or may not be degraded and/or alkoxylated. By degree of substitution is to be understood here the number of substituents, up to a maximum of 3.0 anhydroglucose unit.
In actual practice, the preparation of starch esters having a low degree of substitution is usually carried out by re-esterification with a vinyl ester or by reaction with acetic anhydride under alkaline or neutral conditions. The preparation of a starch ester having a high degree of substitution generally takes place in an organic solvent, use being made of acetic anhydride or an acid chloride. The large scale preparation in this way of starch ester from a higher monocarboxylic acid, however, is unattractive because of the lack of commercial anhydrides or acid chlorides. A problem to the preparation of starch esters is the poor solubility of starch in usual organic solvents and, moreover, starch is poorly accessible to organic compounds, which generally results in a low reactivity.
SUMMARY OF THE INVENTION
The process according to the invention is characterized in that a mixture of 100 parts by weight of starch, 0.5-9 equivalents per anhydroglucose unit of a monocarboxylic acid containing 1-7 carbon atoms and up to 1000 parts by weight of water is subjected to an esterification reaction at a temperature of 40°-270° C., in which process water is withdrawn from the mixture until the resulting starch ester has the degree of substitution desired. Subsequently, to the resulting solution in the monocarboxylic acid of the starch ester thus prepared there may be added a hydroxyl compound which can be esterified with the monocarboxylic acid containing 1-7 carbon atoms and the mixture obtained is subjected to an esterification reaction at a temperature of 40°-270° C. with simultaneously removal of water, so that there is obtained a solution of the starch ester in an ester of the monocarboxylic acid.
Advantages of the present process are that it can readily be applied on a large scale and that instead of expensive anhydrides or acid chlorides, use may be made of inexpensive, water-soluble monocarboxylic acids. Other advantages of the process are that the use of expensive organic solvents can be avoided, and that it can be carried out under the conditions of temperature, pressure and safety precautions normally observed in the chemical industry. Another advantage is that a product is obtained in a form in which it can be directly used in the fields of application mentioned below.
DETAILED DESCRIPTION OF THE INVENTION
The starch which in the process according to the invention is used as starting compound can be obtained in a known way by degradation beforehand or in situ or a natural starch by means of, for example, an acid or in accordance with an oxidative, enzymatic or mechanical method. The starch can be dried at 20° C. in an atmosphere of a relative humidity of 65%. Like cellulose, starch is a polysaccharide, but it differs from cellulose in that the anhydroglucose units are interconnected by a 1,4-β-glucosidic bond instead of a 1.4-α-glucosidic bond. As a starch may be used any starch, such as maize starch, potato starch, wheat starch, rice starch, tapioca starch, or sorghum starch. According to the invention, it is preferred that use should be made of a native starch or a starch which has previously been degraded to a starch having a number average molecular weight of 1200-6000.
For the esterification of the starch with the monocarboxylic acid, it is preferred according to the invention that an aqueous mixture of the starch and the monocarboxylic acid be heated over a period ranging from a few minutes to a few days, preferably 6-14 hours, to a temperature of in particular 60°-165° C. It is preferred that use should be made of 1.0-3.0 equivalnts of the monocarboxylic acid per anhydroglycose unit of the starch. The mixture of the starch and the monocarboxylic acid preferably also contains up to 150 parts by weight of water per 100 parts by weight of starch.
Because of the afore-described esterification reaction, many hydroxyl groups will disappear from the starch, as a result of which it becomes satisfactorily soluble in organic solvents and therefore very suitable for use in coating compositions, printing inks and glues.
Examples of monocarboxylic acids containing 1-7 carbon atoms are formic acid, acetic acid, mono-, di- or tri-chloracetic acid, mercaptoacetic acid, propionic acid, 2-hydroxy-propionic acid, 2-chloropropionic acid, acrylic acid, 2-bromo-2-methyl propionic acid, methacrylic acid, 2,2-dimethyl propionic acid, butyric acid, isobutyric acid and crotonic acid. It is preferred that use should be made of a monocarboxylic acid containing 2-5 carbon atoms.
The esterification of the starch may optionally be carried out in the presence of a catalyst, for instance an acid compound such as methane sulphonic acid, p-toluene sulphonic acid, oxalic acid, sulphuric acid, hydrochloric acid, a sulphonic acid cation exchanger, phosphoric acid, nitric acid, or a Lewis acid, such a zinc chloride or the ether adduct of boron trifluoride. These catalysts are generally applied in a concentration of 0-10% by weight, preferably 2-4% by weight, based on the starch.
During or after the afore-described esterification reaction according to the present process, so much water will be removed from the esterification mixture that a product of the desired degree of substitution is obtained. The water is generally removed by distillation, preferably under reduced pressure and/or by azeotropic distillation, use being made of an organic solvent, such as toluene, xylene, trichloromethane and methylene chloride.
If desired subsequent to the reaction of the starch with the monocarboxylic acid, the remaining free hydroxyls of the starch can be reacted with a carboxylic anhydride or carboxylic halide. Such reactions are well known to those skilled in the art. In the instant invention, such a reaction will result in a degree of substitution of 3, with an increase in hydrophilicity and thus higher solubility in organic solvents.
An essential step in the process according to the invention is the conversion of non-reacted monocarboxylic acid in the solution of the prepared starch ester in the monocarboxylic acid. To this end, a suitable amount of a hydroxyl compound esterifiable with the monocarboxylic acid is added and the resulting mixture subjected to an esterification reaction. As a rule, the esterifiable hydroxyl compound is added in an amount of 0.85-1.0, preferably 0.98-1.0 equivalent per equivalent of monocarboxylic acid. This esterification reaction is generally carried out at a temperature of 40°-270° C., preferably 60°-165° C.
As examples of suitable hydroxyl compounds may be mentioned ethanol, n-propanol, ethylene glycol, 1,6 hexane diol, glycerol, tripropylene glycol and pentaerythritol. It is preferred that use should be made of ethylene glcyol. The water evolved during the esterification reaction is removed by distillation in a known manner, for instance azeotropically, using an organic solvent such as toluene.
The dissolved starch ester prepared by the process of the invention may advantageously be applied in many fields, for instance, as a binder in a coating composition together with a suitable curing agent such as an aminoplast or a polyisocyanate, or as a substitute for cellulose acetobutyrate. The present starch ester solutions may also be used in a UV-curable offset printing ink or as a substitute for ethyl cellulose in a rotogravure ink. Further, they may be applied as so-called polyol component in glues.
The invention will be further described in but not limited by the following examples. The term air-dry starch as used in these examples refers to a starch dried at a temperature of 20° C. in an atmosphere of a relative humidity of 65%. The thickness of the coating was measured in the dried state.
EXAMPLE 1
To a mixture of 693 g of propionic acid and 20 g of paratoluene sulphonic acid contained in a reactor equipped with a stirrer, a gas inlet and an axeotropic water separator there were added, with stirring, 500 g of air-dry, acid-degraded potato starch (moisture content: 10%; number average molecular weight: 1400). The suspension was heated, with stirring, to a temperature of 100° C. After 30 minutes, the starch had dissolved. The solution was then cooled to 80° C. Subsequently, water was distilled off under subatmospheric pressure and the vacuum was gradually increased. After 91/2 hours, the degree of substitution was 1.57 and in all, 400 ml of liquid (120 ml of water and 280 ml of propionic acid) had been removed. After 250 ml of toluene had been added, another 20 ml of water were removed as toluene/water azeotrope. Then 55 g of ethylene glycol were added and, over a period of 2 hours, the remaining propionic acid was esterified, in which process another 20 ml of water were removed azeotropically. Adding 3.9 g of lithium carbonate resulted in the neutralization of the paratoluene sulphonic acid catalyst. After filtration, a clear solution having a solids content of 50% by weight was obtained. The starch ester prepared had a degree of substitution of 1.57 and a number average molecular weight of 2000.
Next, a coating composition was prepared from 140 g of the afore-described starch ester solution, 43 g of a 70% by weight solution of a partially butoxylated melamine, 100 g of rutile titanium dioxide and 10 g of propylene glycol methyl ether acetate; it was ground to a fineness smaller than 5 μm. The composition was brought to spray viscosity (19 seconds DIN-cup No. 4 at 20° C.) with a mixture of equal parts by weight of xylene and propylene glycol methyl ether acetate. The sprayable composition, which had a very high solids content (55% by weight), was sprayed onto a steel panel (Bonder 132) at a pressure of 3 bar and in a thickness of 30 μm. After 10 minutes, the coating was cured for 30 minutes at a temperature of 100° C. The resulting coating displayed a high gloss (95 at 60°), satisfactory hardness (160 seconds Konig hardness) and excellent resistance to organic solvents and water and after a test period of 24 hours the coating did not shown any changes.
EXAMPLE 2
In a reactor fitted with a stirrer, a gas inlet and an azeotropic water separator, a suspension of 300 g of air-dry, acid-degraded potato starch (moisture content: 10%; number average molecular weight: 2500) in a mixture of 300 g of water, 300 g of butyric acid and 6 g of methane sulphonic acid was heated to a temperature of 95° C. After 4 hours, the starch had dissolved. Subsequently, the temperature was decreased to 80° C. and 200 ml of butyric acid were added to the solution. At that temperature, water was removed at subatmospheric pressure and the vacuum was gradually increased. After 81/2 hours, 550 ml of liquid (360 ml of water and 190 ml of butyric acid) had been removed. Following the addition of 270 ml of toluene, another 25 ml of water were removed. The resulting starch ester had a dgree of substitution of 1.6. Subsequently, 200 ml of acetic anhydride were added. After all OH-groups had reacted, acetic acid was distilled off as well as was possible. Subsequently, 125 g of ethylene glycol were added and the remaining butyric acid was esterified and water was removed azeotropically in the same way as indicated in Example 1. After neutralization of the catalyst by means of lithium carbonate and filtration, a clear solution having a solids content of 58% by weight was obtained. The starch ester prepared had a degree of substitution of 3.0, and a number average molecular weight of 3000.
Next, a coating composition was prepared from 11.6 g of the previously prepared solution of the starch ester, 15.8 g of a vinyl acetate copolymer (available under the trademark Cerafak 100 XB 10 of Cera Chemie), 24.0 g of a saturated polyester resin (available under the trademark Setal 173-GR-60 of Kunstharsfabriek Synthese), 6.7 g of a paste of an aluminum pigment (available under the trademark Sparkle Silver AR 5000 of Silberline), 12.2 g of butyl acetate and 8.9 g of xylene. This composition with a relatively high solids content of 43% was sprayed on to a steel panel (Bonder 132) in a coating thickness of 15 μm. After 15 minutes, a conventional clear composition based on an acrylate polyol and a polyisocyanate was applied by spraying wet on wet in a coating thickness of 40 m and cured for 7 days at room temperature. While the clear composition was applied, it was not found to mix (strike-in) with the undercoat. The coating system obtained displayed a good appearance.
EXAMPLE 3
In a reactor equipped with a gas inlet, a stirrer and an azeotropic water separator, 500 g of air-dry, acid-degraded potato starch (moisture content: 10%; number average molecular weight: 1400) were dissolved under nitrogen in 300 g of water at 90° C. Thereupon, 250 g of propionic acid and 5 g of hydroquinone were added. After the solution had become clear, it was cooled to 60° C. and 250 g of acrylic acid and 10 g of methane sulphonic acid were added. After the solution had turned clear again, the removal of water by vacuum distillation was started. After 4 hours, another 100 g of propionic acid and 100 g of acrylic acid were added and the removal of water was continued using toluene as an entrainer. The resulting starch ester had a degree of substitution of 1.5. Thereupon, 425 g of acetic anhydride were added. After all OH-groups had reacted, acetic acid was distilled off as well as was possible. Subsequently, 140 g of ethylene glycol were added and the remaining propionic acid and acrylic acid was esterified and water was removed azeotropically in the same way as indicated in Example 1. After neutralization of the catalyst by means of lithium carbonate and filtration, a clear solution having a solids content of 50% by weight was obtained. The starch ester prepared had a degree of substitution of 3.0 and a number average molecular weight of 2000.
Then an overprint varnish with a viscosity of 5 Pa.s was prepared from 62.6 g of the previously prepared solution of the starch ester, 68.7 g of the triacrylic ester of the adduct of 1 mole of glycerol and 3 moles of propylene oxide and 7.5 g of methoxybenzoin methyl ether. The composition was roller coated onto cardboard in a layer thickness of 12 μm and cured for 1.8 seconds by subjecting it to UV radiation from a high-pressure UV lamp (Hannovia 80 W/cm) positioned at a distance from it of 7 cm. A non-sticky surface was obtained. The coating displayed a gloss higher than 90 at an angle of 60° and very good mechanical properties, such as excellent flexibility.
EXAMPLE 4
The preparation of the starch ester solution according to Example 1 was repeated, except that use was made of a maize starch having a moisture content of 13% and a number average molecular weight of 320×10 6 . This starch was mixed with 500 g of water, 500 g of butyric acid and 10 g of methane sulphonic acid. After 36 hours, the degree of substitution was 1.73. Then 100 g of ethylene glycol were added, and a clear solution with a solids content of 60% by weight was obtained. The starch ester prepared had a degree of substitution of 1.73 and a number average molecular weight of 16,000.
EXAMPLE 5
Example 4 was repeated, except that use was made of an acid-degraded potato starch having a moisture content of 10% and a number average molecular weight of 1400. This starch was mixed with 500 g of water, 1000 g of crotonic acid and 10 g of methane sulphonic acid. The starch ester prepared had a degree of substitution of 1.70. Then 322 g of ethylene glycol were added and a clear solution with a solids content of 32% by weight was obtained. The resulting starch ester had a degree of substitution of 1.70 and a number average molecular weight of 2000.
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Preparation of a starch ester having an Mn of 1000-50,000 and a degree of substitution of 0.4-3.0 by heating a mixture of starch, a Cl-7 monocarboxylic acid, water, and optionally a catalyst and meanwhile withdrawing water until the ester being formed has attained the desired degree of substitution. Optionally remaining free hydroxyl groups may be esterified by reaction with a carboxylic anhydride of -halide. The resulting solution may be treated to neutralize remaining free monocarboxylic acid by mixing it with an esterifiable hydroxyl compound and esterifying it at 40°-270° under the removal of water. In this way, use is made of cheap ingredients, and the resulting product is suitable for immediate use in a number of applications, e.g., as binder in coating compositions.
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TECHNICAL FIELD
The invention relates generally to deriving tilt-corrected seismic data in a seismic sensor module having a plurality of sensing elements arranged in multiple axes.
BACKGROUND
Seismic surveying is used for identifying subterranean elements, such as hydrocarbon reservoirs, fresh water aquifers, gas injection reservoirs, and so forth. In performing seismic surveying, seismic sources are placed at various locations above an earth surface or sea floor, with the seismic sources activated to generate seismic waves directed into the subterranean structure. Examples of seismic sources include explosives, air guns, or other sources that generate seismic waves. In a marine seismic surveying operation, the seismic sources can be towed through water.
The seismic waves generated by a seismic source travel into the subterranean structure, with a portion of the seismic waves reflected back to the surface for receipt by seismic sensors (e.g., geophones, hydrophones, etc.). These seismic sensors produce signals that represent detected seismic waves. Signals from seismic sensors are processed to yield information about the content and characteristic of the subterranean structure.
For land-based seismic data acquisition, seismic sensors are implanted into the earth. Typically, seismic signals traveling in the vertical direction are of interest in characterizing elements of a subterranean structure. Since a land-based seismic data acquisition arrangement typically includes a relatively large number of seismic sensors, it is usually impractical to attempt to implant seismic sensors in a perfectly vertical orientation.
If a seismic sensor, such as a geophone, is tilted from the vertical orientation, then a vertical seismic signal (also referred to as a “compression wave” or “P wave”) would be recorded with attenuated amplitude. Moreover, seismic signals in horizontal orientations (also referred to as “shear waves” or “S waves”) will leak into the compression wave, where the leakage of the seismic signals into the compression wave is considered noise. Since the tilts of the seismic sensors in the land-based seismic data acquisition arrangement are unknown and can differ randomly, the noise will be incoherent from seismic sensor to seismic sensor, which makes it difficult to correct for the noise by performing filtering.
SUMMARY
In general, according to an embodiment, a seismic sensor module includes sensing elements arranged in a plurality of axes to detect seismic signals in a plurality of respective directions. The seismic sensor module also includes a processor to receive data from the sensing elements and to determine inclinations of the axes with respect to a particular orientation. The processor is to further use the determined inclinations to combine the data received from the sensing elements to derive tilt-corrected seismic data for the particular orientation.
Other or alternative features will become apparent from the following description, from the drawings, and from the claims.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 illustrates an exemplary survey arrangement that includes seismic sensor modules according to some embodiments.
FIGS. 2-3 illustrate an exemplary deployment of seismic sensor modules.
FIG. 4 is a schematic diagram of a seismic sensor module according to an embodiment.
FIG. 5 is a flow diagram of a process of deriving tilt-corrected seismic data in the seismic sensor module of FIG. 4 , according to an embodiment.
DETAILED DESCRIPTION
In the following description, numerous details are set forth to provide an understanding of the present invention. However, it will be understood by those skilled in the art that the present invention may be practiced without these details and that numerous variations or modifications from the described embodiments are possible.
FIG. 1 illustrates an example survey arrangement (spread) that includes an array of seismic sensor modules 102 . In accordance with some embodiments, the seismic sensor modules are multi-axis seismic sensor modules that each includes a processor to perform tilt correction to obtain seismic data along a vertical orientation (vertical direction) and to remove or reduce noise due to leakage of seismic signals propagating along horizontal orientations into the vertical seismic signal. More generally, the processor is able to obtain seismic data along a target orientation (which can be a vertical orientation, horizontal orientation, or any other orientation), and the processor is able to remove or reduce noise due to leakage of seismic signals propagating along other orientations into the seismic signal propagating in the target orientation.
The seismic sensor modules 102 are connected by communications links 104 (which can be in the form of electrical cables, for example) to respective routers 106 and 108 (also referred to as “concentrators”). A “concentrator” refers to a communications module that routes data between nodes of a survey data acquisition system.
Alternatively, instead of performing wired communications over electrical cables, the seismic sensor modules 102 can perform wireless communications with respective concentrators.
The concentrators 108 are connected by communications links 110 . Seismic data acquired by the seismic sensor modules 102 are communicated through the concentrators 106 , 108 to a central recording station 112 (e.g., a recording truck). The recording station 112 includes a storage subsystem to store the received seismic data from the seismic sensor modules 102 . The recording station 112 is also responsible for management of the seismic sensor modules and concentrators, as well as the overall network.
One or more seismic sources 114 are provided, where the seismic sources 114 can be activated to propagate seismic signals into a subterranean structure underneath the earth on which the arrangement of seismic sensor modules 102 are deployed. Seismic waves are reflected from the subterranean structure, with the reflected seismic waves received by the survey sensor modules in the survey spread.
FIG. 2 illustrates three seismic sensor modules 102 A, 102 B, 102 C that have been implanted into the earth 200 . Each seismic sensor module 102 A, 102 B, or 102 C includes a respective implantation member (e.g., anchor) 202 A, 202 B, or 202 C that has a tip to allow for ease of implantation. The seismic sensor module 102 B has been implanted into the earth 200 to have a substantially vertical orientation (vertical direction) such that the seismic sensor module 102 B is not tilted with respect to the vertical orientation (Z axis of the sensor module 102 B is parallel to the vertical orientation). Also shown are X and Y axes, which are the horizontal axes that are orthogonal to each other and orthogonal to the Z axis.
The seismic sensor module 102 C has been implanted to have a slight tilt such that the Z axis is at an angle β with respect to the vertical orientation. The seismic sensor module 102 A has a much larger tilt with respect to the vertical orientation; in fact, the seismic sensor module 102 A has been improperly implanted to lay on its side such that its Z axis is greater than 900 offset with respect to the vertical orientation.
As further depicted in FIG. 2 , each of the seismic sensor modules 102 A, 102 B, and 102 C includes a respective processor 210 A, 210 B, and 210 C. Each processor 210 A, 210 B, or 210 C is able to perform tilt correction according to some embodiments to correct for tilt of the respective seismic sensor module from the vertical orientation. After tilt correction, the Z, X and Y axes are properly oriented, as shown in FIG. 3 . More specifically, in FIG. 3 , the Z axis of each of the seismic sensor modules 210 A, 210 B, and 210 C is generally parallel to the vertical orientation. As a result, the seismic data along the Z axis is tilt-corrected with respect to the vertical orientation.
FIG. 4 illustrates a seismic sensor module 102 according to an embodiment. The seismic sensor module 102 has a housing 302 defining an inner chamber 303 in which various components can be provided. The components include seismic sensing elements 304 , 306 , and 308 along the Z, X, and Y axes, respectively. In one embodiment, the seismic sensing elements 304 , 306 , and 308 can be accelerometers.
The seismic sensing elements 304 , 306 , and 308 are electrically connected to a processor 210 in the seismic sensor module 102 . The “processor” can refer to a single processing component or to multiple processing components to perform predefined processing tasks. The processing component(s) can include application-specific integrated circuit (ASIC) component(s) or digital signal processor(s), as examples. The processing component(s) can be programmed by firmware or software to perform such tasks. The “processor” can also include filtering circuitry, analog-to-digital converting circuitry, and so forth (which can be part of or external to the processing circuitry).
The processor 210 is connected to a storage device 212 , in which tilt-corrected seismic data 214 computed by the processor 210 can be stored. The seismic sensor module 102 also includes a telemetry module 216 , which is able to send tilt-corrected seismic data over the communications link 104 (which can be a wired or wireless link). In accordance with some embodiments, instead of sending tilt-corrected seismic data in all three axes, just the tilt-corrected seismic data along a single axis (e.g., Z axis) is sent. As a result, communications link bandwidth is conserved, since the amount of seismic data that has to be sent is reduced. In one implementation, the telemetry module 216 sends the Z-axis tilt-corrected seismic data in one single telemetry channel, instead of multiple telemetry channels to communicate seismic data for all three axes. The phrase “telemetry channel” refers to a portion of the communications link bandwidth, which can be a time slice, a particular one of multiple frequencies, and so forth.
Referring further to FIG. 5 , the seismic sensing elements 304 , 306 , and 308 (e.g., accelerometers) record (at 502 ) seismic signals (particle motion signals) in the three respective Z, X, and Y axes. Also, each seismic sensing element 304 , 306 , and 308 records the component of the gravity field along the respective Z, X, or Y axis. The gravity field component recorded by each seismic sensing element is the DC component. In an alternative implementation, the seismic sensing elements 304 , 306 , and 308 can be implemented with a three-component ( 3 C) moving coil geophone.
The processor 210 determines (at 504 ) the inclinations of the seismic sensing elements 304 , 306 , and 308 . The inclination of each respective seismic sensing element is determined by extracting the DC component (expressed in terms of g or gravity) of the recorded signal from the seismic sensing element. The DC component can be extracted by taking an average of the recorded signal over time, or by filtering out the high-frequency components of the recorded signal (using a low-pass filter). The arccosine of the DC component provides the inclination of each axis (Z, X, or Y) with respect to the vertical orientation. Alternatively, if the seismic sensing elements 304 , 306 , and 308 are implemented with a 3 C moving coil geophone, then inclinometers can be used to measure the Inclinations of the elements.
If the seismic sensing elements 304 , 306 , and 308 are arranged to be exactly orthogonal to each other, then the inclinations of the seismic sensing elements 304 , 306 , and 308 with respect to the vertical orientation will be the same value. However, due to manufacturing tolerances, the seismic sensing elements 304 , 306 , and 308 may not be exactly orthogonal to each other, so that the inclinations can be slightly different.
Once the inclinations of the seismic sensing elements 304 , 306 , and 308 are known, the processor 210 rotates (at 506 ) the seismic data recorded by the seismic sensing elements 304 , 306 , and 308 to the vertical orientation and to the two orthogonal horizontal orientations, respectively. Rotating the seismic data involves extrapolating the recorded (tilted) seismic data to the respective vertical or horizontal orientation, as well as removing any noise caused by leakage into a seismic signal along a first orientation (e.g., vertical orientation) of seismic signals in other orientations (e.g., horizontal orientations).
Next, the vertical tilt-corrected seismic data only is sent (at 508 ) by the seismic sensor module 102 . By sending just the vertical tilt-corrected seismic data and not the horizontal seismic data, communications link bandwidth is conserved. In alternative embodiments, instead of sending just the vertical seismic data, horizontal tilt-corrected seismic data can be sent instead. In fact, the seismic sensor module 102 can be selectively programmed or instructed by the recording station 112 (such as in response to a command by a human operator) to send tilt-corrected seismic data along a particular orientation. Also, the operator can select that non-tilt-corrected seismic data along one or more orientations is sent, which may be useful for test, trouble-shooting, or quality control purposes. As yet another alternative, different signal orientations can be sent from different sensor modules, at different spatial spacing. For example, vertical direction can be selected for all sensor modules, and horizontal direction(s) can be selected for only a subset of these sensor modules.
In a different implementation, techniques according to some embodiments can be applied in a seismic data acquisition arrangement that uses just shear-wave seismic sources (e.g., shear-wave acoustic vibrators). As a result, a seismic sensor module will record in just the X and Y horizontal orientations. If the seismic sensor module further includes a compass or magnetometer, then the X and Y seismic signals can be rotated to account for inclinations with respect to any target azimuth (e.g., source-receiver direction or perpendicular to the source-receiver direction, to obtain radial or transverse energy from the shear wave generated by the shear-wave seismic source). After rotation, just the seismic data along one direction has to be sent.
In the same survey, compression-wave seismic sources can also be activated, with the seismic sensor module recording the seismic signal along the vertical orientation. In this case, only the vertical seismic data would be transmitted by the seismic sensor module for recording in the recording station 112 ( FIG. 1 ).
In addition to the tasks depicted in FIG. 5 , alternative implementations can also perform seismic sensor module calibration between tasks 502 and 504 . Also, filtering can be applied between tasks 502 and 504 , and/or between 506 and 508 , to filter out noise such as ground roll noise, which is the portion of a seismic source signal produced by a seismic source that travels along the ground rather than travels into the subterranean structure.
While the invention has been disclosed with respect to a limited number of embodiments, those skilled in the art, having the benefit of this disclosure, will appreciate numerous modifications and variations therefrom. It is intended that the appended claims cover such modifications and variations as fall within the true spirit and scope of the invention.
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A seismic sensor module includes sensing elements arranged in a plurality of axes to detect seismic signals in a plurality of respective directions, and a processor to receive data from the sensing elements and to determine inclinations of the axes with respect to a particular orientation. The determined inclinations are used to combine the data received from the sensing elements to derive tilt-corrected seismic data for the particular orientation.
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RELATED APPLICATION
[0001] This patent application is a continuation of co-pending application Ser. No. 13/338,971, filed on Dec. 28, 2011, which claims priority to U.S. Provisional Application Ser. No. 61/490,403, filed on May 26, 2011, the contents of each are hereby incorporated by reference in their entirety.
FIELD
[0002] Disclosed herein is a light wavelength converting material for taggant applications and quantitative diagnostics.
ENVIRONMENT
[0003] In the processing and packaging of various consumer products, oils, greases and lubricants may come into contact with the product.
[0004] Typically, lubricants can come into contact with consumer products due to leakage of lubricants through gaskets or seals, from sliding mechanisms, from drum systems, from gear boxes, from pumps, from sealed rolling bearing units, from chains and belts, and the like. For example, lubricants are used in a variety of machines commonly used in the preparation and packaging of produce for market.
[0005] Since lubricants of similar compositions are used throughout the various stages of produce treatment and packaging, it is often difficult for the manufacturer to locate the source of a particular lubricant. As such, the manufacturer is forced to conduct a time consuming search for the source of the lubricant which is lowering the quality of the manufactured products.
[0006] One possible way to detect the presence of undesired lubricants would be to add a taggant to the lubricant that could be readily detected on-line and at production speeds. However, suitable oil soluble taggants are not known to exist.
[0007] Therefore, it would be advantageous if an oil-soluble taggant could be developed that would enable inspection to be conducted on-line, in real time, during the production process.
SUMMARY
[0008] In one form, disclosed is a fluorescent taggant composition, comprising a Stokes-shifting taggant, which absorbs radiation at a first wavelength and emits radiation at a second wavelength, different from said first wavelength; and an oil or lubricant.
[0009] In another form, disclosed is a taggant composition, comprising an oil-soluble fluorescent taggant and an oil or lubricant.
[0010] In yet another form, disclosed is a compound comprising a tetrabutylammonium chloride complex of Indocyanine Green (ICG).
BRIEF DESCRIPTION OF THE DRAWINGS
[0011] The forms disclosed herein are illustrated by way of example, and not by way of limitation, in the figures of the accompanying drawings and in which like reference numerals refer to similar elements and in which:
[0012] FIG. 1 is a representation of the infrared absorption and emission peaks of the Indocyanine Green (ICG) complex taggant, illustrating the Stokes-shift;
[0013] FIG. 2 is a representation of the infrared absorption and emission peaks of a modified ICG-complex, illustrating a secondary emission peak;
[0014] FIG. 3 is a representation of the infrared absorption peak for the modified ICG-complex of Example 1;
[0015] FIG. 4 is a representation of the infrared excitation and emission peaks for the modified ICG-complex of Example 1; and
[0016] FIG. 5 is an H-nuclear magnetic resonance scan of the ICG-complex according to this invention.
DETAILED DESCRIPTION
[0017] Various aspects will now be described with reference to specific forms selected for purposes of illustration. It will be appreciated that the spirit and scope of the apparatus, system and methods disclosed herein are not limited to the selected forms. Moreover, it is to be noted that the figures provided herein are not drawn to any particular proportion or scale, and that many variations can be made to the illustrated forms. Reference is now made to FIGS. 1-5 , wherein like numerals are used to designate like elements throughout.
[0018] Each of the following terms written in singular grammatical form: “a,” “an,” and “the,” as used herein, may also refer to, and encompass, a plurality of the stated entity or object, unless otherwise specifically defined or stated herein, or, unless the context clearly dictates otherwise. For example, the phrases “a device,” “an assembly,” “a mechanism,” “a component,” and “an element,” as used herein, may also refer to, and encompass, a plurality of devices, a plurality of assemblies, a plurality of mechanisms, a plurality of components, and a plurality of elements, respectively.
[0019] Each of the following terms: “includes,” “including,” “has,” “having,” “comprises,” and “comprising,” and, their linguistic or grammatical variants, derivatives, and/or conjugates, as used herein, means “including, but not limited to.”
[0020] Throughout the illustrative description, the examples, and the appended claims, a numerical value of a parameter, feature, object, or dimension, may be stated or described in terms of a numerical range format. It is to be fully understood that the stated numerical range format is provided for illustrating implementation of the forms disclosed herein, and is not to be understood or construed as inflexibly limiting the scope of the forms disclosed herein.
[0021] Moreover, for stating or describing a numerical range, the phrase “in a range of between about a first numerical value and about a second numerical value,” is considered equivalent to, and means the same as, the phrase “in a range of from about a first numerical value to about a second numerical value,” and, thus, the two equivalently meaning phrases may be used interchangeably.
[0022] It is to be understood that the various forms disclosed herein are not limited in their application to the details of the order or sequence, and number, of steps or procedures, and sub-steps or sub-procedures, of operation or implementation of forms of the method or to the details of type, composition, construction, arrangement, order and number of the system, system sub-units, devices, assemblies, sub-assemblies, mechanisms, structures, components, elements, and configurations, and, peripheral equipment, utilities, accessories, and materials of forms of the system, set forth in the following illustrative description, accompanying drawings, and examples, unless otherwise specifically stated herein. The apparatus, systems and methods disclosed herein can be practiced or implemented according to various other alternative forms and in various other alternative ways.
[0023] It is also to be understood that all technical and scientific words, terms, and/or phrases, used herein throughout the present disclosure have either the identical or similar meaning as commonly understood by one of ordinary skill in the art, unless otherwise specifically defined or stated herein. Phraseology, terminology, and, notation, employed herein throughout the present disclosure are for the purpose of description and should not be regarded as limiting.
[0024] Provided are new oil soluble, light wavelength-converting, preferably upconverting, compositions for taggant applications and quantitative diagnostics in connection with lubricants, such as by way of non-limiting example, the detection of errant lubricants on product that comes into contact with lubricated machinery. Other taggant applications are contemplated, including, but not limited to, anti-counterfeiting, brand protection, or verification that a machine contains a correct lubricant, and other possible applications. A detection system enables the development of near real time, low cost, compact, portable and highly sensitive detection, monitoring and diagnostics of modifications to manufacturing process systems in real world environments. It is the unique process (e.g. the conversion of visible light to infrared light, infrared to visible light and the upconversion of infrared to higher energy infrared) that enables high sensitivity detection against almost any sample or environmental background.
[0025] Using the system, theoretical particle detection (10 −23 mol) of molecules added to analytic mixtures can be achieved through the use of on-line verification methods and even handheld detection applications. Detection sensitivity of 10 −20 mol is possible in a variety of detection schemes, and even direct visual detection of 10 −14 mol sensitivity has been demonstrated using a hand held 3.0 to 9.0 volt laser diode system against backgrounds of various colors and compositions. The narrow emission bandwidths and small particle size of these materials enable the simultaneous detection of multiple analytes (i.e. multiplexed assays).
[0026] According to the present invention, a detectable taggant compound is added to the various lubricants used in manufacturing and processing machinery, and advantageously taggant compounds having different characteristics are added into the lubricants at different processing locations, such that detection of one or more of these taggant compounds can enable rapid identification of the location of the source of lubricant contamination in the manufactured product.
[0027] Advantageously, the taggant compound is one which is detectable by fluorescence when it is exposed to particular wavelengths of light. In particular, a suitable taggant is one which absorbs energy at one wavelength and fluoresces/emits at a different wavelength. Such materials are well-known in the art as Stokes-shifting materials, and have recently found increasing use in inks for security marking of documents, such as banknotes and the like, to render such documents less susceptible to counterfeiting or copying.
[0028] However, most conventional Stokes-shifting and anti-Stokes shifting materials are composed of inorganic compounds, such as doped rare earth metal particles as described in U.S. Published Patent Application No. 2010/0219377, which are insoluble in lubricants. It would be advantageous if taggant compounds could be formulated to be soluble or dispersible in oils or lubricants.
[0029] According to the present invention, the taggant may be an organic compound comprised of purified crystals from naturally occurring chlorophyll. Suitable naturally-occurring chlorophyll crystals include Chlorophyll A (CAS number 1406-65-1) and Chlorophyll B (CAS number 519-62-0). These taggants are known as being down-converting or fluorescent, and are sensitive to excitation at a particular narrow bandwidth of IR light (680 nanometers). The taggant emits light at a different wavelength (715 nanometers). A similar compound may be a benze-indolium perchlorate or a benze-indolium tosolyate. Such materials absorb at around 670 nanometers and emit at a wavelength of about 713 nanometers. The chemical structure for Chlorophyll A is provided below.
[0000]
[0000] Since this compound is an organic chemical, it is readily dissolved in oils and lubricants.
[0030] In another form, an oil-soluble fluorescent material has been developed based on Indocyanine Green (ICG), the chemical structure of which is provided below.
[0000]
[0031] ICG is sodium 4-[2-[1E,3E,5E,7Z)-7-[1,1-dimethyl-3-(4-sulfonatobutyl)-benzo[e]indol-2-ylidene]hepta-1,3,5-trienyl]-1,1-dimethyl-benzo[e]indol-3-ium-3-yl]butane-1-sulfonate, an infrared fluorescing compound currently used in the medical industry for imaging cells and blood flows in the human body, which in its conventional form is water-soluble.
[0032] The newly developed taggant is an ICG-complex available from Persis Science LLC, Andreas Pa. The chemical structure for a tetrabutylammonium chloride complexation of ICG is provided below and analytical structural information is provided in FIG. 5 .
[0000]
[0033] The new ICG-complex is sensitive to a particular narrow absorption band of IR light between about 760 to about 810 nanometers ( FIG. 3 ), and emits light at a different band between about 810 to about 840 nanometers ( FIG. 4 ), with discrete absorbance peaks at about 785 nanometers ( FIGS. 4 ) and 805 nanometers ( FIG. 1 ), and a discrete emission peak at about 840 nanometers ( FIG. 1 ).
[0034] The ICG complex can be added to oils or lubricants in the amounts of approximately 1 ppb to 5%, preferably a range of 1 ppm to 2000 ppm, based on the weight of the lubricant.
[0035] Additionally, the nature of the ICG complexing agent can be modified to impart one or more secondary NIR reflectance wavelengths adjacent to the major emission peak at 840 nanometers. By utilizing such variations in the complexing agent, and adding differently complexed ICG compounds in lubricants at differing locations in the overall process, a single detector can be located at the end of the process, and when contamination is detected, the contaminated product can be removed from the process and further analyzed for said secondary NIR reflectance peaks, to determine the location of the source of contamination. FIG. 2 is an illustration of the absorption and emission peaks of a modified ICG-complex, showing a secondary emission peak of a longer wavelength on the shoulder of the primary emission peak.
[0036] The detection system of the present invention can be used in many processes and for consumer products which are susceptible to lubricant contamination during the manufacturing process, such as for example in the growing, collection, processing and/or packaging of packaged consumer goods, such as food products, beverages, tipped and non-tipped cigars, cigarillos, snus and other smokeless tobacco products, smoking articles, electronic cigarettes, distilled products, pharmaceuticals, frozen foods and other comestibles, and the like. Further applications could include clothing, furniture, finished wood or lumber or any other manufactured or packaged product wherein an absence of oil spotting is desired.
[0037] The taggant can be added to process machinery lubricants in minor amounts, so as to obtain ultimate concentrations in the oil/lubricant as low as between about 10 ppm and 100 ppm, typically at a concentration of about 50 ppm. At these taggant concentration levels the detection system can detect as little as 10 microliters of oil, or even as little as 1 microliter of tagged oil.
[0038] However, in order to provide for easier treatment of oils or lubricants already in place within various machines, it can be more convenient to formulate a master batch of the taggant in any particular oil, wherein the taggant is mixed at higher concentrations in the base oil/lubricant, such as from about 0.1 to about 5 wt % taggant, or even from about 0.2 to about 2 wt % taggant, in a balance of the base oil/lubricant. A portion of such tagged master batch is then easily transported and added to oils/lubricants which are already in place in the machines to be treated, for example by adding a small amount of the tagged master batch to the oil sump of the machine.
[0039] When the taggant is not an oil-soluble taggant, such as when it is an inorganic particle, an optional surfactant or dispersant additive can be added in an amount effective to facilitate dispersion of the taggant particles in the base oil. Such surfactants/dispersants are well-known in the art and their identities need not be repeated herein.
[0040] Specific forms will now be described further by way of example. While the following examples demonstrate certain forms of the subject matter disclosed herein, they are not to be interpreted as limiting the scope thereof, but rather as contributing to a complete description.
EXAMPLES
Example 1
[0041] 500 mg of complexed ICG (Product No. OT-1013, available from Persis Science LLC of Andreas Pa.) is dispersed into 1.0 kg of Klüberoil 68 using a speedmixer. Klüberoil 68 is available from Klüber Lubrication North America L.P., Londonderry, N.H. The material is mixed for 10.0 minutes at a speed of 2100 RPM. The resulting master batch concentrate is slowly added to an additional 100.0 kg of Kluberoil 68 while stirring under high speed dispersion. A sample of the material is placed into a Shimadzu 5301 Fluorometer and the excitation and emission spectrographs are recorded. When excited at a wavelength of 785, a strong infrared emission is noted from 810 nanometers to 960 nanometers. See FIG. 3 for a representation of the infrared absorption peak for the ICG-complex of Example 1 and FIG. 4 for a representation of the infrared excitation and emission peaks for the ICG-complex of Example 1.
Example 2
[0042] The above example is modified slightly using a tetrabutylammonium bromide complexation of an Infrared dye IR830, available from Sigma-Aldrich of St. Louis, Mo. After mixing, it is noted that the material will produce fluorescence around 833 nanometers when excited with approximately 0.5 mW of 785 light.
Example 3
[0043] Upconverting nanoparticles, MED C-19 (Yb 2 O 3 :Er 3+ ), were obtained from Persis Science, LLC in a slurry format in DMSO. The DMSO was dialyzed from the aqueous phase leaving the particles in aqueous phase. The particles were dried and dispersed into Kluberoil 68 using a Speedmixer. The dispersion was measured optically using a Spex Fluorolog-3. The oil suspension was excited at 970 nm and the detection occurred in the visible from 400 to 700 nm to determine the presence of the tagged oil.
Example 4
[0044] 0.5 wt % of a europium chelate, available from Honeywell Corporation under the trade name of CD-335, was incorporated into 99.5 wt % of Lubriplate 220 oil using a horizontal media mill. Adequate detection was achieved using UV LED's at a wavelength of 363 nm and an APD detector with a 600 nm-700 nm notch filter.
Example 5
[0045] 1.0 wt % of an infrared absorbing dithiolene dye commercially available from Epolin, Inc—358 Adams St. Newark N.J. 07105, was dissolved via mixing with 99 parts of Kluber Oil 220 under nitrogen with a stir bar for 5 hours. The resulting mixture was analyzed for infrared absorption. The absorption occurred from 800 nm to 1200 nm with a peak at around 1060 nm. The detection was achieved by contrast imaging with a Cognex In-Sight vision system and using a Monster LED light system with a wavelength of 850 nm. A Midwest optical filter 850 bandpass was used to isolate the absorption.
[0046] While the present invention has been described and illustrated by reference to particular forms, those of ordinary skill in the art will appreciate that the invention lends itself to variations not necessarily illustrated herein. For this reason, then, reference should be made solely to the appended claims for purposes of determining the true scope of the present invention.
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A process for detecting oil or lubricant contamination in the production of an article by adding a Stokes-shifting taggant to an oil or lubricant of a machine utilized to produce the article or a component thereof, irradiating the articles produced with a first wavelength of radiation, and monitoring the articles for emission of radiation at a second wavelength. The taggant can be in the form of a composition containing a Stokes-shifting taggant, which absorbs radiation at a first wavelength and emits radiation at a second wavelength, different from said first wavelength, dissolved or dispersed in an oil or lubricant.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a coreless packaging substrate and a method for manufacturing the same, and, more particularly, to a light weighted and compact coreless packaging substrate, and a method for manufacturing the same.
2. Description of Related Art
As the electronic industry develops rapidly, researches move towards electronic devices with multifunction and high efficiency. Hence, circuit boards with lots of active and passive components and circuit connections thereon transfer from single-layered boards to multiple-layered boards so that the requirements such as integration and miniaturization in semiconductor packaging substrate can be met. Furthermore, interlayer connection technique is also applied in this field to expand circuit layout space in a limited circuit board and to meet the demand of the application of high-density integrated circuits.
For manufacturing conventional semiconductor packaging structures, a chip is mounted on the top surface of a substrate first, and then connected thereto by wire bonding. Alternatively, the chip is connected with the substrate by flip chip technique. Subsequently, solder balls are disposed on the bottom surface of the substrate and electrically connected to a printed circuit board. However, even though the purpose of high quantity pin counts can be achieved through the method illustrated above, the electrical performance of a device operated in high frequency or at high speed can be unstable or limited due to the long paths of conductive circuits. Moreover, the complexity of the manufacturing process is relatively increased because many connective interfaces are required for conventional semiconductor packaging structures.
In the method for manufacturing a flip-chip substrate, a packaging substrate is formed by providing a core board at first, and then followed by drilling, metal electroplating, plugging, circuit patterning, and so on to complete an inner structure. Subsequently, a multilayer substrate is afforded by built-up processes, as shown in FIGS. 1A to 1E , which show a flowchart for manufacturing a built-up type multilayer substrate. In FIG. 1A , a core board 11 is prepared first. The core board 11 includes a core layer 111 having a predetermined thickness, and a circuit layer 112 formed thereon. Meanwhile, the core layer 111 has a plurality of plated through holes (PTHs) 113 formed therein so that the PTHs 113 can be electrically connected to the circuit layer 112 on the core layer 111 . As shown in FIG. 1B , the core board 11 is processed through a built-up process. The built-up process is illustrated as follows. First, a dielectric layer 12 is disposed on the surface of the core board 11 . The dielectric layer 12 has a plurality of vias exposing part of the circuit layer 112 serving as conductive pads 112 a . With reference to FIG. 1C , a seed layer 14 is formed by electroless plating or sputtering on the surface of the dielectric layer 12 . Then, a patterned resist layer 15 is formed on the seed layer 12 so that the conductive pads 112 a can be exposed by a plurality of openings 150 formed in the resist layer 15 . With regard to FIG. 1D , conductive vias 16 a and a patterned circuit layer 16 are formed by electroplating respectively in the vias and in the openings 150 of the resist layer 15 . The circuit layer 16 can be electrically connected to the conductive pads 112 a by the connection of the conductive vias 16 a . Subsequently, the resist layer 15 and the seed layer 14 covered thereby are removed to afford a first circuit built-up structure 10 a . Referring to FIG. 1E , a second built-up structure 10 b is formed on the surface of the first built-up structure 10 a in the same manner as the first built-up structure 10 a so that a multilayer packaging substrate 10 is obtained.
The above-mentioned manufacturing begins from provision of a core board, followed by drilling, metal electroplating, plugging, circuit patterning and so on to complete an inner structure, and finally to performing built-up processes to afford a multilayer packaging substrate. However, in the manufacturing illustrated above, there is a need to form PTHs by drilling and electroplating etc. Therefore, many circuit layout spaces are occupied by the PTHs because the diameter and the depth of each PTH are greater than those of each conductive via. Moreover, undesirable cross-talk, noises, or signal decay resulting from excessive length of signal transmitting pathway could easily occur. In order to solve the disadvantages arising from long signal transduction pathway, the design of the circuit layout is often dense on a chip disposition side electrically connected to a chip. In contrast, the density of the circuit layout on a solder ball disposition side connected to a printed circuit board could be sparse. For most of the packaging substrates, the numbers of the circuit layers on the both sides are identical. When the density of the circuit layout on the solder ball disposition side is too sparse, not only many layout spaces are idle, but also the number of laminated layers is increased. Because multiple circuit layers need to be included, manufacturing processes become more complex. In addition, the packaging substrate is hard to be used in high frequency because of long conductive circuits and high impedance.
SUMMARY OF THE INVENTION
In view of the above-mentioned, the present invention provides a method for manufacturing a coreless packaging substrate comprising the following steps. First, a core board is provided. Then, a metal adhesive layer is formed on the surface of the core board. Subsequently, a patterned first solder mask layer is formed on the surface of the metal adhesive layer, wherein the first solder mask layer has a plurality of first openings. Further, a metal pillar is formed in each of the first openings, and a metal layer is formed on the surface of the metal pillars and part of the surface of the first solder mask layer. Furthermore, a circuit built-up structure is formed on the surfaces of the metal layer and the first solder mask layer, wherein the metal layer is embedded in the circuit built-up structure. Moreover, a patterned second solder mask layer is formed on the circuit built-up structure, wherein the second solder mask layer has a plurality of second openings exposing circuits of the circuit built-up structure, and the exposed circuits serve as second conductive pads. Finally, the core board and the metal adhesive layer are removed to expose the metal pillars serving as first conductive pads.
Also, the present invention provides a coreless packaging substrate which can be manufactured by the foregoing method but is not limited thereto.
The coreless packaging substrate in the present invention comprises: a circuit built-up structure, a first solder mask layer, and a second solder mask layer. A plurality of metal layers are embedded under one surface of the circuit built-up structure, and a plurality of second conductive pads are formed on the other surface of the circuit built-up structure. The first solder mask layer is disposed on the surface of the circuit built-up structure having the metal layers, which has a plurality of first openings exposing part of the metal layers. Each of the first openings has a metal pillar therein, and the metal pillars serve as first conductive pads. The second solder mask layer is disposed on the surface of the circuit built-up structure having the second conductive pads, which has a plurality of second openings to expose the second conductive pads.
In the present invention, the first conductive pads and the second conductive pads can be bump pads or ball pads. While the first conductive pads are bump pads electrically connected to a chip, the second conductive pads in the other surface of the circuit built-up structure can be ball pads electrically connected to an electronic device such as a printed circuit board. On the other hand, while the first conductive pads are ball pads electrically connected to an electronic device such as a printed circuit board, the second conductive pads in the other surface of the circuit built-up structure can be bump pads electrically connected to a chip.
In the method for manufacturing a coreless packaging substrate in the present invention, the metal adhesive layer is formed by electroplating or electroless plating. In addition, the metal adhesive layer is made of a metal having a melting point lower than that of the packaging substrate. Preferably, the metal can be Sn. Therefore, the metal adhesive layer can be removed preferably by thermomelting so as to be removed at the same time of removing the core board.
In the processes for manufacturing a coreless packaging substrate in the present invention, the core board used preferably can be a copper clad laminate (CCL).
The method for manufacturing a coreless packaging substrate in the present can further comprise forming a seed layer prior to form the metal pillars and the metal layer. The seed layer is mainly used as a conductive pathway of electric currents for follow-up processes, and can be made of a material selected from the group consisting of Cu, Sn, Ni, Cr, Ti, and Cu—Cr alloys. Herein, the seed layer is made by sputtering or electroless plating.
In the method of the present invention for manufacturing a coreless packaging substrate, the metal pillars and the metal layer can be formed at the same time. In detail, a seed layer can be formed on the surface of the first solder mask layer and in the first openings. Subsequently, a patterned resist layer is formed on the first solder mask layer in order to expose the first openings. Then, electroplating is performed. Finally, the resist layer and the part of the seed layer covered by the resist layer are removed so that the metal pillars and the metal layer are formed at the same time. Besides, the metal pillars and the metal layer in the present invention can be preferably made of Cu.
In the method of the present invention for manufacturing a coreless packaging substrate, the first openings in the first solder mask and the second openings in the second solder mask are formed preferably by photolithography process including exposing and developing.
The circuit built-up structure of the present invention can comprise a dielectric layer, circuit layers disposed on the dielectric layer, and conductive vias formed in the dielectric layer. Besides, the circuit built-up structure of the present invention can be monolayer or multilayer. The circuit layers in the circuit built-up structure of the present invention, which also includes the second conductive pads formed from the circuit layers on the surface of the circuit built-up structure, and the conductive vias can be made of a material selected from the group consisting of Cu, Sn, Ni, Cr, Ti, and Cu—Cr alloys, but preferably is made of Cu.
In conclusion, the present invention provides a solution to problems such as low circuit layout density, excessive circuit layers, long conductive lines and high impedance in a general packaging substrate having a core board. Additionally, the coreless packaging substrate of the present invention does not have through holes so as to achieve the purposes of advanced circuit layout density, reduced manufacture procedures, and decreased thickness of the packaging substrate. Therefore, the object of obtaining a lightweight and compact packaging substrate can be accomplished.
Other objects, advantages, and novel features of the invention will become more apparent from the following detailed description when taken in conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIGS. 1A to 1E are cross-sectional views of conventional packaging substrates;
FIGS. 2A to 2E show a flow chart for manufacturing a coreless packaging substrate in a cross-sectional view in a preferred example of the present invention; and
FIGS. 3A to 3B show part of a flow chart for manufacturing a coreless packaging substrate in a cross-sectional view in a preferred example of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Because of the specific embodiments illustrating the practice of the present invention, a person having ordinary skill in the art can easily understand other advantages and efficiency of the present invention through the content disclosed therein. The present invention can also be practiced or applied by other variant embodiments. Many other possible modifications and variations of any detail in the present specification based on different outlooks and applications can be made without departing from the spirit of the invention.
The drawings of the embodiments in the present invention are all simplified charts or views, and only reveal elements relative to the present invention. The elements revealed in the drawings are not necessarily aspects of the practice, and quantity and shape thereof are optionally designed. Further, the design aspect of the elements can be more complex.
EXAMPLE 1
With reference to FIGS. 2A to 2E , there is shown a process flow for manufacturing a coreless packaging substrate in a cross-sectional view in the present example.
As shown in FIG. 2A , a core board 20 is provided first. In the present example, a copper clad laminate is used as the core board 20 . Then, a metal adhesive layer 21 is formed on the surface of the core board 20 by electroplating or electroless plating. The material of the metal adhesive layer 21 used in the present example is Sn. The melting point of Sn is at about 232° C., and that is lower than those of other materials used in the packaging substrate of the present example. Besides, the copper clad laminated used in the present example is beneficial to form the metal adhesive layer 21 thereon.
Subsequently, a patterned first solder mask layer 22 is formed on the surface of the metal adhesive layer 21 as shown in FIG. 2B . For example, the first solder mask layer 22 can be made of photoimagable polymer. A plurality of first openings are formed in the first solder mask layer by photolithography. Then, a seed layer (not shown) is formed by sputtering or electroless plating on the surface of the first solder mask layer 22 and in the first openings 221 . The seed layer can be made of a material selected from the group consisting of Cu, Sn, Ni, Cr, Ti, and Cu—Cr alloys, but preferably is made of Cu. Furthermore, a resist layer 23 is formed on the surface of the first solder mask layer 22 . A resist open area 231 corresponding to each of the first openings 221 is formed by photolithography. Herein, the resist layer 23 can be made of dry film or liquid photoresist. In the present example, dry film is used as the resist layer 23 .
Further, a metal pillar 241 and a metal layer 242 are formed by electroplating or electroless plating respectively in each of the first openings 221 and in each of the resist open areas 231 . Then, the resist layer 23 and the part of the seed layer covered by the resist layer 23 are removed so that the structure as shown in FIG. 2C can be afforded.
Furthermore, in FIG. 2D , a circuit built-up structure 30 is formed on the surfaces of the metal layer 242 and the first solder mask layer 22 . The circuit built-up structure 30 comprises a dielectric layer 31 , circuit layers 32 , and conductive vias 33 . The circuit layers 32 are formed by photolithography of a resist layer (not shown) together with electroplating, and disposed on the dielectric layer 31 . The conductive vias 33 are formed in the dielectric layer 31 through forming vias (not shown) by laser ablation together with electroplating. Herein, the metal layer 242 is embedded in the dielectric layer 30 of the circuit built-up structure 30 . The conductive vias 33 can be electrically connected to the metal layer 242 . In addition, the circuit layers 32 and the conductive vias 33 can be made of a material selected from the group consisting of Cu, Sn, Ni, Cr, Ti, and Cu—Cr alloys. In the present example, Cu is used as the material of the circuit layers 32 and the conductive vias 33 . The dielectric layer 31 can be made of, for example, Ajinomoto Build-up Film (ABF). Subsequently, a second solder mask layer 25 is formed on the circuit built-up structure 30 . A plurality of second openings 251 are formed by photolithography on the second solder mask layer 25 so as to expose the circuit layers 32 of the circuit built-up structure 30 , and the exposed circuit layers 32 can serve as ball pads 51 which can be electrically connected to an electronic device such as printed circuit board.
Finally, as shown in FIG. 2E , the structure shown in FIG. 2D can be heated to melt the metal adhesive layer 21 . Due to the metal adhesive layer 21 having a melting point lower than those of the other materials used in the packaging substrate of the present example, the temperature can be raised to the point higher than the melting point of the metal adhesive layer 21 but lower than that being tolerated by the other materials in the packaging substrate so that the core board 20 can be removed after the metal adhesive layer 21 is melted. After that, chemical solutions can be used to clean and remove residues of the metal adhesive layer 21 . Surface treatment can be further performed on the metal pillars 241 to improve the performance of the packaging substrate. Posterior to removing the core board 20 , the metal pillars 241 of the circuit built-up structure formed in each of the first openings 221 can serve as a bump pad 41 capable of being electrically connected to a chip. Accordingly, the coreless packaging substrate of the present invention is manufactured.
Conclusively, the coreless packaging substrate in the present example, as shown in FIG. 2E , comprises: a circuit built-up structure 30 , a first solder mask layer 22 , and a second solder mask layer 25 . A plurality of metal layers 242 are embedded under one surface of the circuit built-up structure 30 , and a plurality of ball pads 51 are formed on the other surface of the circuit built-up structure 30 . The first solder mask layer 22 is disposed on the surface of the circuit built-up structure 30 having the metal layers 242 , which has a plurality of first openings 221 exposing part of the metal layers 242 . Each of the first openings 221 has a metal pillar 241 therein, and the respective metal pillar 241 serves as a bump pad 41 . The second solder mask layer 25 is disposed on the surface of the circuit built-up structure 30 having the bump pads 51 , which has a plurality of second openings 251 to expose the bump pads 51 .
EXAMPLE 2
With reference to FIGS. 3A to 3B , there is shown a flow chart for manufacturing a coreless packaging substrate in a cross-sectional view in the present example. The manner of the present example is approximately similar to that of Example 1, but there are differences illustrated as follows. As shown in FIG. 3A , the metal pillars 241 in the present example are used mainly for conduction to an electronic device such as printed circuit board in the follow-up processes. Positions exposed by the second openings 251 of the second solder mask layer 25 on the circuit layers 32 in the circuit built-up structure 30 are used for connection to a chip in the follow-up processes. Therefore, the first openings 221 formed in the first solder mask layer 22 are of the diameter larger than those of the second openings 251 formed in the second solder mask layer 25 .
The subsequent steps are the same as those of the Example 1. After the core board 20 is removed in the present example, as shown in FIG. 3B , each metal pillar 241 can serve as a ball pad 52 electrically connected to printed circuit board. Finally, the coreless packaging substrate of the present example can be afforded.
Accordingly, the coreless packaging substrate of the present example is different from that of the Example 1, especially in that each metal pillar 241 embedded under one surface of the circuit built-up structure 30 serves as a ball pad 52 for conduction to printed circuit board, and the bump pads formed on the other surface of the circuit built-up structure 30 are electrically connected to a chip.
In conclusion, the present invention provides a metal adhesive layer which has a melting point lower than that of the coreless packaging substrate thereof. This is why the core board adhered to the coreless packaging substrate of the present invention can be removed by using the above-mentioned property of the metal adhesive layer. Besides, in the circuit built-up structure of the packaging substrate in the present invention, the metal layers are embedded under one surface thereof. The solder mask layer is disposed on the surface having the metal layers and has a plurality of openings exposing part of the metal layers. Additionally, there is a metal pillar in each of the openings, and each metal pillar can serve as a bump or ball pad so as to be electrically connected to a chip or printed circuit board. Hence, in the present invention, not only the purposes (for an advance in circuit layout density and possession of a compact and light packaging substrate) can be achieved, but also the problems (such as large number of circuit layers and complexity of manufacturing processes) can be solved.
Although the present invention has been explained in relation to its preferred embodiment, it is to be understood that many other possible modifications and variations can be made without departing from the scope of the invention as hereinafter claimed.
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Method for making a coreless packaging substrate are disclosed in the present invention. The coreless packaging substrate is made by first providing a metal adhesion layer having a melting point lower than that of the substrate, and removing a core board connected with the substrate therefrom through melting the metal adhesion layer. In addition, the disclosed packaging substrate further includes a circuit built-up structure of which has the electrical pads embedded under a surface. The disclosed packaging substrate can achieve the purposes of reducing the thickness, increasing circuit layout density, and facilitating the manufacturing of the substrate.
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RELATED U.S. APPLICATION
[0001] This application is based upon and claims the benefit of Provisional Application No. 60/310,323 filed Aug. 6, 2001.
SPECIFICATION
[0002] Field of the Invention
[0003] The present invention relates to baseball games, and particularly to the game of T-ball.
BACKGROUND OF THE INVENTION
[0004] Baseball has been and continues to be a very popular sport in the United States and in many foreign countries. With the development of better medical understanding of the stresses imposed on players, a variation of the baseball game known as T-ball has become increasingly popular as a means of avoiding injury to young players' arms from throwing baseballs at too early an age. The game of T-ball avoids the necessity of having a skilled catcher in order to retrieve balls thrown by a pitcher. T-ball is played by means of placing a ball on some form of mount where it can be hit by a player swinging a baseball bat in the same manner that a player would swing at a ball being thrown by a pitcher. The T-ball holding device is similar in several respects to many batting training apparatuses or batting tees which allow baseball players to practice their swing without the necessity of a human pitcher.
[0005] A successful T-ball apparatus requires that the device holding the ball be adjustable to accommodate players of different sizes. The adjustment should be easily accomplished in a short period of time.
[0006] Additionally, the pieces of the assembly should be strong enough to withstand the strength of being hit by a baseball bat when the batter swings and misses the ball.
[0007] For example, U.S. Pat. No. 4,979,741 entitled “Batting Training apparatus” which issued to Butcher (1990), shows a batting training apparatus with a ball mounted on a vertical stand that enables a user to determine an improper swing.
[0008] U.S. Pat. No. 5,004,234 entitled “Adjustable Batting Tee” which issued to Hollis (1991) shows a batting tee in which the vertical ball holding member is movable with respect to the home plate base unit.
[0009] U.S. Pat. No. 5,388,823 entitled “Adjustable Baseball Batting Tee” which issued to Prieto (1995) also shows a batting tee in which the vertical ball holding member is movable within a plurality of locations within the strike zone.
[0010] U.S. Pat. No. D373,806 entitled “Batting Tee” which issued to Bunnell (1996) shows a batting tee unit in which the vertical ball holding member is movable within the confines of the home plate unit.
[0011] U.S. Pat. No. 5,556,091 entitled “Baseball Holder for Baseball Batting Practice” issued to Lin (1996) shows a baseball holder in which the ball holding member can be adjusted radially from and around the center of home plate.
[0012] U.S. Pat. No. 5,893,806 entitled “Batting Instruction Method and Apparatus” issued to Martinez (1999) shows a Baseball T that has two ball supporting members.
[0013] U.S. Pat. No. 5,897,444 entitled “Ball Support Batting Tee” issued to Hellyer (1999) shows baseball tee that has at least two interconnected arm members that pivot from the base.
[0014] U.S. Pat. No. 5,928,092 entitled “Batting Tee for Baseball and Softball” issued to Keeter et al.(1999) shows a baseball tee holder that includes a horizontal member with multiple ball holding means.
[0015] U.S. Pat. No. D410,052 entitled “Support Base for a Baseball Batting Practice Tee” issued to Davis et al. (1999) shows a batting Tee whereby the vertical member is slidably connected to home plate.
[0016] U.S. Pat. No. 6,358,163 entitled “Durable Batting Tee for Baseball” issued to Tanner (2002) shows an adjustable compression nut and an inverted flexible cone.
[0017] Additionally, there are several design patents that also disclose batting Tees: U.S. Pat. No. D430,243 issued to Alberti et al. (2000), U.S. Pat. No. D430,629 issued to Alberti (2000), U.S. Pat. No. D433,722 to Hsu et al., and U.S. Pat No. D451,566 to De Chenne (2001).
[0018] Unfortunately, the prior art patents fail to meet the light weight and easily transportable requirements associated with today's young players as well as the dictates of manufacture and shipping required in today's marketplace. Therefore, what is needed is a T-ball device which is easily transportable, light and durable, and can be easily moved from one playing location to another by young players.
[0019] Furthermore, what has become ever more important, is that the apparatus should be contained in some form of storage means which allows the components to be broken down into a relatively small space. The small space is extremely desirable since very often these items are made overseas and shipped to the United States. The volume of space occupied by the assembly will have a very large effect on the final price of the goods. The more compact the assembly, the lower the freight charges will be.
SUMMARY OF THE INVENTION
[0020] To achieve the aims set forth above, the present invention sets forth an assemblage of parts manufactured of lightweight materials which can be quickly and easily assembled. The height of the holder for the ball can be easily and quickly adjusted.
[0021] The entire unit, including the home plate base, can be easily disassembled, thus minimizing its size and bulk for storage and/or for shipping. The home plate base is formed by two interlocking segments which are fixed in position by means of a locking collar. The locking collar also positions the base member that supports a vertical stanchion member that raises the level of the ball holder above home plate.
[0022] An extension rod telescopically fits within the upper end of the stanchion member and has a positioning grommet that easily slides along the outer circumference of the extension member to position the extension member so as to elongate and increase the height of the ball holding member located on the end of the extension member.
[0023] Storage means are provided with the kit to enable the parts to be disassembled and stored in a compact manner for easy storage and transportation.
OBJECTS OF THE INVENTION
[0024] It is therefore an object of the present invention to provide a plastic T-ball game kit.
[0025] It is another object of the present invention to provide a T-ball game kit that is easy to assemble and disassemble.
[0026] It is another object of the present invention to provide a T-ball game kit that is easy to ship and transport.
[0027] It is another object of the present invention to provide a T-ball game kit that is to be used by children and adults of different ages.
[0028] It is another object of the present invention to provide a T-ball game kit that is safe and durable.
[0029] It is another object of the present invention to provide a T-ball game kit that is adjustable for children and adults.
[0030] It is another object of the present invention to provide a T-ball game kit that allows children to practice their baseball swings.
[0031] It is another object of the present invention to provide a extra safe T-ball game kit in which the bat and ball are made of foam rubber.
BRIEF DESCRIPTION OF THE DRAWINGS
[0032] For a more complete understanding of the present invention, reference may be had to the following description of the preferred embodiments taken in connection with the following drawings, of which:
[0033] [0033]FIG. 1 is a perspective view of the various components of the T-ball game kit of the present invention.
[0034] [0034]FIG. 2 is a view of the home plate unit, adjusted to an intermediate height position.
[0035] [0035]FIG. 3 is a view of the assembled home plate unit with the extension member retracted to its minimum length and the ball resting on top of the ball holding unit.
[0036] [0036]FIG. 4 is an exploded view of the Home plate unit showing the various components of the assembly.
[0037] [0037]FIG. 5 is a side view showing the assembled home plate unit with certain components in partial cross section.
[0038] [0038]FIG. 6 is an exploded view of the T-ball holding member showing certain components in partial cross section.
[0039] [0039]FIG. 7 is a bottom view of the home plate showing the male and female portions before assembly.
[0040] [0040]FIG. 8 a is a side view of the positioning grommet.
[0041] [0041]FIG. 8 b is a top view of the positioning grommet.
[0042] [0042]FIG. 9 a is a side view of the locking nut which joins the locking collar to hold the two segments of home plate together.
[0043] [0043]FIG. 9 b is a top view of the locking nut showing the grooves in the flange, which receives the base screw member.
[0044] [0044]FIG. 10 is a perspective view of the component parts of the present invention contained in plastic packaging forming a kit.
DETAILED DESCRIPTION OF THE INVENTION
[0045] The present invention is principally composed of a home plate unit 10 , an apparatus for holding a ball at an elevated position. The invention can also include a bat 12 and a ball 14 . The bat consists of a foam rubber material having plastic end caps 16 and 18 and a hollow cylindrical supporting core around which the foam is positioned. Optionally, the bat can include a handle such as that found in U.S. Pat No. D443,907 to Tarica.
[0046] [0046]FIG. 2 shows a T-ball player in a position ready to swing the bat at the ball resting on top of the home plate unit. The home plate unit includes a home plate 20 , a stanchion supporting base 80 , a stanchion member 90 , an extension member 22 and a T-Ball holding member 26 . The home plate, the stanchion supporting base, the stanchion member, the extension member and the T-ball holding member can be made of plastic or any other suitable material, such as wood or aluminum. When assembled, the extension member may be retracted as shown in FIG. 3, extended as shown in FIG. 1, or in an intermediate position as shown in FIG. 2.
[0047] The T-ball holding member 26 , as further illustrated in FIGS. 4, 5 and 6 , has a top 28 and bottom 30 . The top 28 includes an inwardly curved shaped cup 27 upon which the ball 14 is placed. The bottom 30 of this holding member includes an opening 32 into which one end of the extension member 22 is inserted. The T-ball holder contains a horizontal annular depression 34 designating the juncture of the lower cylindrical portion 31 from the upper tapered portion 29 of the T-ball holding member. The inner surface of the annular depression 34 provides an internal stop for the end of the extension member 22 when it is inserted into the bottom 30 of the T-ball holding member.
[0048] The extension member 22 , shown in FIGS. 1, 2, 4 , 5 and 6 , is tubular and hollow and has both a bottom end 23 and a top end 24 .
[0049] [0049]FIGS. 4, 5, and 6 , show a positioning grommet 40 which is placed around the extension member 22 for purposes of vertically adjusting the height of the extension member. The grommet is preferably made of plastic or rubber. As shown in FIGS. 8 a and 8 b , the positioning grommet 40 has an upper face 42 , a lower face 44 and a bore 46 . Resilient positioning fingers 48 extend into the bore of the positioning grommet. As can be seen from FIGS. 5 and 6 , the diameter of the bore 46 is smaller than the outer diameter of the stanchion member 90 so that the positioning grommet will sit on the top of the stanchion member and cannot be positioned lower than the top of the stanchion member. The diameter of bore 46 is wider than the outer diameter of the extension member 22 , but the ends of the resilient positioning fingers 48 form a circular opening which has a circumference which is smaller than the outer circumference of the extension member.
[0050] Therefore, the positioning grommet can be slid over the extension member by deformation of the resilient positioning fingers 48 and slid along the extension member 22 until a desired extension length is achieved. The extension member will then telescope into the upper end of stanchion member 90 up to the position of the positioning grommet. The deformation of the resilient positioning fingers is sufficient to hold the positioning grommet in its location against the combined weight of the extension member and the T-ball holding member.
[0051] FIGS. 3 - 6 show a stanchion member 90 . The stanchion member is a tubular cylinder with an upper end 92 and a lower end 94 . The inner diameter of the stanchion member is such that the extension member can be slidably inserted inside.
[0052] FIGS. 3 - 6 also show a stanchion supporting base 80 . The stanchion supporting base has an upper, non-threaded end 82 and a lower threaded end 84 . The upper end of the stanchion supporting base has a diameter sufficient to receive the lower end of the stanchion member. The lower end of the stanchion supporting base is threaded to receive the threaded base screw member 74 .
[0053] [0053]FIGS. 2, 4 and 7 show top and bottom views of a home plate 20 . The home plate is pentagon-shaped and is comprised of two segments, a male segment 50 and a female segment 52 . The male segment and the female segment each have a top side 54 and a bottom side 56 . The bottom sides of both the female 52 and male 50 segments contain structural strengthening ribs 58 and 59 , respectively. The male and female segments 50 and 52 , respectively have raised portions 106 and 108 . The raised portions include arcuate semi-circular grooves 102 , 104 , respectively, circumferentially disposed about the aperture 64 which is formed by semi-circular depressions 65 in male segment 50 and 69 in female segment 52 . The male segment has joining fingers 60 , while the female segment has corresponding joining pockets 62 . Each of the male and female segments contain a semicircular groove 102 , 104 , respectively of a locking collar 64 .
[0054] [0054]FIGS. 4, 5, 6 , 9 a and 9 b show a locking collar 66 . The locking collar 66 has a bottom 69 and top 70 . Additionally, located on the interior surface of the locking collar is a flange 67 that contains grooves 68 . The flange contains an upper face 71 and a lower face 72 . The locking collar 66 is positioned within the ring formed about aperture 64 , which ring is formed by the semi-circular grooves 102 and 104 in home plate segment member 50 and 52 when the segments are assembled to form home plate.
[0055] [0055]FIGS. 4 and 6 show the threaded base screw member 74 . The threaded base screw member has a screw head 76 that contains extensions 75 at opposite sides. The extensions 75 engage grooves 68 in locking collar 66 when the home plate unit 10 is assembled. The threaded base screw member fits through the bottom of the locking collar and aperture 64 of the assembled plate to engage the threaded end of the stanchion supporting base.
[0056] [0056]FIG. 10 shows a packaging container made of clear molded plastic which contains a top half and a bottom half designed to compactly hold all of the components of the game kit.
[0057] To use the kit described, only the home plate unit 20 needs assembly. Before assembly begins, the component pieces must be removed from the plastic packaging container 100 .
[0058] The home plate unit is assembled from the bottom up, i.e., from the home plate up to the T-ball holding member. Home plate is assembled by putting the joining fingers 60 of the male segment 50 into the joining pockets 62 of the female segment 52 , as shown in FIG. 4. The locking collar 66 is then placed in the circumferential groove 110 about aperture 64 formed by arcuate grooves 102 , 104 so that the locking collar holds the male and female segments of home plate together. The threaded base screw member 74 is inserted through the locking collar 66 as shown in FIGS. 4 and 6, in such a manner that the extensions 75 fit into the grooves 68 of the locking nut and the locking collar is held firm by friction fit in the circumferential groove 110 . When properly inserted, the threaded base screw member will not rotate separately from the locking collar. Additionally, the threaded portion 77 of the base screw member 74 will extend past the top of the raised portion of home plate as shown in FIG. 5.
[0059] The lower threaded end 72 of the stanchion supporting base 80 is then screwed onto the protruding threaded portion of the threaded base screw member 74 . The stanchion member, if not already so, is inserted in the stanchion supporting base. The positioning grommet 40 is then placed on extension member 22 which then is inserted into the stanchion member 90 . The positioning grommet on the extension member will abut the top of the stanchion member. Next, the T-ball holding member 26 is inserted on top of the extension member, as shown in FIGS. 4 - 6 . This is accomplished by placing the top of the extension member 22 into the bottom opening 32 of the T-ball holding member. The home plate unit is now completely assembled. To disassemble the home plate unit, the aforementioned process is preferably performed in reverse order, going from top to bottom, i.e., from T-ball holding member to home plate.
[0060] In storing or packing the components of the present invention, the following is the preferred order of steps. First, the bat, the ball, and the T-ball holding member are placed into the bottom half of the packaging container 100 having depressions formed to hold these items, 112 for the bat 114 for the stanchion and extension members and 116 for the ball holding member. Before placing the stanchion member in the packaging container, the positioning grommet should be placed on the end of the extension member, which should then be placed inside the stanchion member. The locking nut should then be placed on the other end of the stanchion member and the threaded base screw should be inserted into the threaded end of the stanchion supporting base, and the whole assembly placed into the bottom half of the packaging container. The top half of the packaging container is now placed on top of the bottom half of the packaging container. The female segment of home plate is slid into the proper molded portion of the top half of the packaging container and the male segment of home plate is slid under the female segment of home plate and into the proper molded portion of the top half of the packaging container. FIG. 10 shows a top view of the present invention inside the packaging container.
[0061] The present invention is used for children as well as adults who want to either play a game of T-ball with others, or who may want to practice their batting. After assembling the home plate unit, the T-ball batter approaches the home plate unit and adjusts the height of the T-ball holding member. The adjustment is accomplished by moving the extension member either up or down, with the positioning grommet resting on top of the stanchion member. The desired height of the T-ball holding member may depend on such factors as the batter's height, age, and swing. Once the T-ball holding member is adjusted, the ball is then placed on the T-ball holding member. The batter then approaches the home plate unit with bat in hand, as illustrated in FIG. 2, just as a baseball player would approach home plate in a normal baseball game. After positioning himself or herself in front of the home plate unit, the batter swings at the ball located on top of the T-ball holding member, hoping to hit the ball. If the swing is successful or the ball falls off the T-holder, the ball is retrieved, repositioned and the batter tries again. If the swing is unsuccessful, the batter may still swing again.
LIST OF ELEMENTS
[0062] [0062] 10 home plate unit
[0063] [0063] 12 bat
[0064] [0064] 14 ball
[0065] [0065] 16 , 18 end caps
[0066] [0066] 20 home plate
[0067] [0067] 22 extension member
[0068] [0068] 23 bottom end
[0069] [0069] 24 top end
[0070] [0070] 26 T-ball holding member
[0071] [0071] 27 inwardly curved shaped cup
[0072] [0072] 28 top
[0073] [0073] 29 upper tapered portion
[0074] [0074] 30 bottom
[0075] [0075] 31 lower cylindrical portion
[0076] [0076] 32 opening
[0077] [0077] 34 annular depression
[0078] [0078] 40 positioning grommet
[0079] [0079] 42 upper face
[0080] [0080] 44 lower face
[0081] [0081] 46 bore
[0082] [0082] 48 resilient positioning fingers
[0083] [0083] 50 male segment
[0084] [0084] 52 female segment of 20
[0085] [0085] 54 top side— 50 , 52
[0086] [0086] 56 bottom side— 50 , 52
[0087] [0087] 58 structural strengthening ribs— 58
[0088] [0088] 59 structural strengthening ribs— 50
[0089] [0089] 60 joining fingers
[0090] [0090] 62 joining pockets
[0091] [0091] 64 aperture
[0092] [0092] 65 semi-circular depression— 50
[0093] [0093] 66 locking collar
[0094] [0094] 67 flange
[0095] [0095] 68 grooves
[0096] [0096] 70 top
[0097] [0097] 71 lower face
[0098] [0098] 72 upper face
[0099] [0099] 74 threaded base screw member
[0100] [0100] 75 extensions
[0101] [0101] 76 head
[0102] [0102] 77 threaded end
[0103] [0103] 80 stanchion supporting base
[0104] [0104] 82 lower, threaded end
[0105] [0105] 84 upper, non-threaded end
[0106] [0106] 90 stanchion member
[0107] [0107] 92 upper end
[0108] [0108] 94 lower end
[0109] [0109] 100 packaging container
[0110] [0110] 102 groove 50
[0111] [0111] 104 groove 52
[0112] [0112] 106 raised position 50
[0113] [0113] 108 raised position 52
[0114] [0114] 112 depression for holding bat
[0115] [0115] 114 depression for holding extension and stanchion
[0116] [0116] 116 depression for holding ball holder
[0117] [0117] 118 depression for holding ball
[0118] [0118] 120 molded holder for 52
[0119] [0119] 122 molded holder for 50
[0120] It will be understood that the embodiments described herein are merely exemplary and that a person skilled in the art may make many variations and modifications without departing from the spirit and scope of the invention. All such modifications and variations are intended to be included within the scope of the invention as described herein.
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A baseball playing kit includes telescoping vertical supports mounted on a base plate. An intermediate support is adjustable in height for different sized users. A tapered support holds a foam covered ball at the upper end. The base is divided into segments that can be easily assembled. A lower threaded vertical support is secured to the base by a threaded base member and a locking member secures the base segments together. A foam covered bat is included. The various components are separable for packaging into a small container for shipping and storage and are easily assembled into a complete game unit.
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BACKGROUND OF THE INVENTION
In the clotting of blood, the α- and β-chains of blood protein fibrinogen is cleaved at the Arg-Gly (arginyl glycine) bonds by the enzyme thrombin, producing fibrin which polymerizes and is subsequently crosslinked enzymatically to form a permanent blood clot. The art suggests that the specificity of the thrombin-fibrinogen reaction is attributable to the amino acid sequence of the α- and β-chains of fibrinogen, particularly in the vicinity of the Arg-Gly bonds. In the synthesis of the 14-22 sequence of the α(A) chain of human fibrinogen for study of its activity, i.e., binding and cleavage, toward the enzyme thrombin, analogs and fragments of this nonapeptide were synthesized in order to assess how activity toward thrombin would vary with change or alteration of structure.
SUMMARY OF THE INVENTION
In the course of the research leading to this invention, biological screeing revealed that certain novel derivatives of the tripeptide, Gly-Pro-Arg (glycylprolylarginine) exhibited substantial anticoagulant activity in vitro. While the tripeptide itself was known, and was found to occur in the α(A) chain of the fibrinogen of many mammalian species, derivatives of this invention were not previously known. It was also discovered as part of this invention that some derivatives of the dipeptide, pro-Arg(prolylarginine) were compounds to have high in vitro anti-coagulant activity. The new cmpounds of this invention, then, encompass protected Pro-Arg dipeptides and protected Gly-Pro-Arg tripeptides and their salts with a pharmaceutically acceptable acid (the anions of which are relatively innocuous to mammals at dosages consistent with good biological activity of said salts) and, when recovered from methanol, may be solvated with methanol, e.g., a member of the group consisting of L-prolyl-L-arginine benzyl ester p-toluenesulfonate trifluoroacetate, glycyl-L-prolyl-L-arginine benzyl ester p-toluenesulfonate trifluoroacetate, N-t-butyloxycarbonyl-L-prolyl-L-arginine benzyl ester p-toluenesulfonate methanolate, N-benzyloxycarbonyl-L-prolyl-L-arginine benzyl ester p-toluenesulfonate methanolate and N-t-butyloxycarbonylglycyl-L-prolyl-L-arginine benzyl ester p-toluenesulfonate, and similarly protected peptides and their salts. The protective groups used in the synthesis of products of this invention are those conventionally used in polypeptide synthesis for protecting amino and carboxylic acid groups. Representative protective groups are indicated in the preparative examples.
Since simple peptides and their derivatives are readily degradable, e.g., to amino acids, the compounds of this invention would be expected to be less toxic than heparin and coumarin derivatives in animal therapy. Also, their effects as anticoagulants are shorter-lived than coumarin or heparin or their derivatives, hence the probability of excessive bleeding should be easier to control.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
The following additional description and examples further describe the invention and the manner and process of making and using it to enable the art skilled to make and use the same and set forth the best mode contemplated by the inventors of carrying out the invention.
PREPARATION A:
ARGININE BENZYL ESTER DI-P-TOLUENESULFONATE
A stirred mixture of 8.7 g. (0.05 mole) of L-arginine, 20.9 g. (0.11 mole) of p-toluenesulfonic acid monohydrate, 125 ml. of benzyl alcohol and 130 ml. of benzene was refluxed for ca. 18 hours. Azeotropic removal of water was facilitated by the use of a Dean-Stark trap. The reaction mixture was decanted from the reaction vessel while still warm and diluted with ethyl acetate, precipitating the product as a white hygroscopic solid. The product was collected on a sintered glass funnel while it was protected from atmospheric moisture by a solvent blanket consisting first of a solution of benzyl alcohol and ethyl acetate, then ethyl acetate and finally ether. The ether-damp solid was then dried in the funnel in a vacuum desiccator over Drierite desiccant. There was obtained 26 g. (85%) of white solid which had a neutral equivalent of 598 vs. theory of 609. Infrared (Nujol mull): ν, 3180 and 3280 (N-H), 2700 (≡N +--H ), 1755 (>C=O, ester)cm + 1 . Exposure of the product to air resulted first in liquefaction followed by crystallization of the hydrate, m.p. 66°-67.5°C., [α] D 25 + 2.16 (c 1.946, ethanol), N.E. 627 (theory 627).
Anal. Calcd for C 27 H 36 N 4 O 8 S 2 .H 2 O: C,51.74; H,6.11; N, 8.94; S, 10.23. Found: C, 51.47; H, 6.07; N, 8.85; S,9.94.
EXAMPLE 1: N-t-Butyloxycarbonyl-L-prolyl-L-arginine Benzyl Ester p-Toluenesulfonate Methanolate
A. Dicyclohexylcarbodiimide Coupling Procedure
A stirred mixture of 11.0 g. (0.018 mole) of arginine benzyl ester di-p-toluenesulfonate, 2.08 g. (0.018 mole) of N-hydroxysuccinimide, 3.90 g. (0.0181 mole) of N-t-butyloxycarbonyl-L-proline and 100 of acetonitrile was treated with 2.52 ml. (0.0181 mole) of triethylamine. This mixture was then cooled to ≦0°C. whereupon a solution of 3.75 g. (0.0181 mole) of dicyclohexylcarbodiimide in ca. 10 ml. of acetonitrile was added. Stirring in the cold was continued for 3 hours and at room temperature for 48 hours. Precipitated dicyclohexylurea (3.8 g., 94%) was removed by filtration and washed with acetonitrile. The combined filtrate and wash was freed of solvent in vacuo and the residue was partitioned between 100 ml. portions of methylene chloride and water. The organic layer was separated, washed again with water, dried over Na 2 SO 4 and Drierite desiccant and freed exhaustively of solvent. There was left as the residue 11.9 g. of white amorphous, foam-like solid. This solid, 10.6 g., was stirred in 200 ml. of ether, and the mixture was filtered. Evaporation of the filtrate left 10.0 g. of amorphous foam-like solid. A 2.0 g. portion of this was heated in 80-100 ml. of benzene and filtered; evaporation of the filtrate left 1.8 g. of white solid (same appearance as observed previously) of which 1.5 g. was chromatographed on a column (2.2 (O.D.) × 30 cm) of silica gel which was prepared with methylene chloride. The column was eluted with 100 ml. of methylene chloride, then a mixture of methylene chloride and methanol (4:1, v/v). There was recovered from the main fraction, 1.2 g., of purified product. Tlc(SiO 2 ; 250 μ,n-BuOH:AcOH:H 2 O, 3:1:1): U.V. sensitive, R f 0.77 (p-toluenesulfonic acid), 0.87 (dipeptide product); chlorination (t-BuOCl/KI plus o-tolidine) sensitive, R f 0.87; ninhydrin sensitive, none. [α] D 25 - 40.3°C.(c 2.07, ethanol). Nmr (DMSO-D 6 (DMSO-d.sub. - 1.34 (singlet, (CH 3 ) 3 C--), -1.72 (cluster, ##EQU1## in Pro and Arg), -2.31 (singlet, ##SPC1##
, -3.20 (cluster, --CH 2 --N in Pro and Arg), -3.46 (singlet CH 3 OH), -4.2 (cluster, α-methinyl protons in Pro and Arg), -5.13 (singlet, ##SPC2##
-7.15 and -7.58 (doublets of p-toluenesulfonic acid ring protons superimposed over some --N--H's) -7.36 (singlet, ring protons of benzyl function) ppm (TMS).
Anal. Calcd. for C 23 H 35 N 5 O 5 .CH 3 C 6 H 4 SO 3 H.CH 3 OH: C, 55.9; H, 7.1; N, 10.5; S, 4.82. Found: C, 56.4; H, 6.8; N, 10.9; S, 4.98.
B. mixed Anhydride Coupling Procedure
To a stirred mixture of 10.8 g. (0.05 mole) of N-t-butyloxycarbonyl-L-proline and 100 ml. of methylene chloride protected from atmospheric moisture was added a solution of 6.84 g. (0.05 mole) of i-butyl choroformate in 10 ml. of methylene chloride. This mixture was cooled to -20°C. whereupon a solution of 5.06 g. (0.05 mole) of N-methylmorpholine in 10 ml. of methylene chloride was added dropwise during 3-5 minutes, the reaction temperature being maintained at ≦-15°C. Five minutes after the addition was completed a cold (ca. 5°C.) solution of 31.2 g. (0.05 equivalent) of L-arginine benzyl ester di-p-toluenesulfonate and 5.06 g. (0.05 mole) of N-methylmorpholine in ca. 150 ml. of methylene chloride was added in small portions to the well-stirred reaction mixture, the temperature being controlled between -15° to -10°C. After the addition, stirring was continued at -17° to -13°C. for 30 minutes, -13° to -7°C. for 45 minutes and then allowed to warm slowly to room temperature and stir overnight. The opaque reaction mixture was washed (2 × 100 ml.) with water, dried (MgSO 4 ), filtered through diatomaceous earth and evaporated to dryness in vacuo leaving 32.6 g. of cream-white, amorphous, foam-like solid as the residue. This was triturated in 150 ml. of water, then partitioned between 250 ml. of methylene chloride. The organic layer was separated, dried (MgSO 4 ), treated with Darco activated carbon and evaporated to dryness in vacuo leaving 31.3 g. of white foam-like solid. This was powdered and stirred under 390 ml. of ether overnight; the ether was decanted and the solid washed with ether by decantation and dried by yielding 29.3 g. of product which was finally purified as previously by chormatography on a column (6.5 × 56 cm) of silica gel. The column was eluted first with ca. 1 l. of methylene chloride and thereafter with methylene chloridemethanol (9:1 v/v Fractions 1-14 (200 ml.) were free of any material; fractions 15-21 (150 ml.) contained, after evaporation, 0.1, 8.1, 4.8, 3.7, 1.6, 0.5 and 0.2 g., respectively; fractions 16-20 left characteristically white, amorphous foam-like solids which were shown by thin-layer chromatography to be homogeneous and identical to the product of part A. Nmr spectra were also identical to that of the product of part A. Total yield, 18.7 g. (56%).
EXAMPLE 2: L-Prolyl-L-arginine Benzyl Ester p-Toluenesulfonate Trifluoroacetate
N-t-Butyloxycarbonyl-L-prolyl-L-arginine p-toluenesulfonate methanolate, 3.7 g. (5.55 mmoles), was stirred in 25 ml. of a solution of methylene chloride-trifluoroacetic acid (2:3 v/v) containing 1% anisole while protected from moisture. After 25 minutes, the solution was evaporated in vacuo at room temperature. Ether was added to the concentrate and the mixture was evaporated again. The residue was dissolved in 40-50 ml. of methylene chloride and diluted to 200 ml. with ether. Resulting crystallization of the product was facilitated by scratching then cooling. The product was collected on sintered glass, washed with methylene chloride-ether solution and ether, and dried to yield 2.8 g. (78%) of white solid. Nmr spectrum of the product was essentially like that of the starting material, except for the absence of the t-butyl and the methyl (methanol absorptions. [α] D 25 -25.2 (c 1.092, ethanol).
Anal. Calcd. for C 18 H 25 N 5 O 5 .CH 3 C 6 H 4 SO 3 H.CF 3 CO 2 H: C, 50.1; H, 5.60; N, 10.8; Found: C, 49.9; H, 5.42; N, 10.6.
EXAMPLE 3: N-t-Butyloxycarbonylglycyl-L-prolyl-L-arginine Benzyl Ester p-Toluenesulfonate
To a stirred solution of 12.0 g. (0.02 equiv.) of L-prolyl-L-arginine benzyl ester p-toluenesulfonate 598), 3.6 (Neut. Equiv. = 3.6 g. (0.0206 mole) of N-t-butyloxycarbonylglycine, and 2.05 g. (0.0203 mole) of triethylamine in 90 ml. of methylene chloride at -5°C. was added in portions a solution of 4.2 g. (0.0203 mole) of dicyclohexylcarbodiimide in 20 ml. of methylene chloride. Stirring was continued at -5° to 0°C. for 1.5 hours, then allowed to warm slowly to room temperature and stir overnight. After removal of dicyclohexylurea by filtration, the filtrate and wash were evaporated and the residue was partitioned between 50 ml. of water and 125 ml. of methylene chloride. The organic layer was separated, dried (MgSO 4 ) and evaporated leaving 14.2 g. of white gelatinous solid. This was dissolved in 85 ml. of benzene, filtered through diatomaceous earth and the filtrate was diluted with 300 ml. of ether which caused the separation of a semi-solid mass. When settling was complete, the mixture was decanted and the residue was triturated with ether causing complete solidification of the mass. The solid was collected, washed with ether, dried at room temperature under modest vacuum, then at 50-55°C. in a vacuum oven. Obtained 12.6 g. of white powder-like solid. Nmr (DMSO-d 6 ): -1.37 (sharp singlet, (CH 3 ) 3 C--), -1.8 (cluster, ##EQU2## in Pro and Arg), -2.3 (singlet, ##SPC3##
ca. -3.5 (cluster, ##EQU3## of Pro and Arg and CH 2 of Gly), -4.35 (cluster, α-methinyl protons), -5.13 (singlet, ##SPC4##
-7.35 (singlet, benzyl ring protons), -7.18 and -7.61 (doublets, ring protons of ##SPC5##
ppm (TMS).
EXAMPLE 4: Glycyl-L-Prolyl-L-Arginine Benzyl Ester p-Toluenesulfonate Trifluoroacetate
N-t-Butyloxycarbonylglycyl-L-prolyl-L-arginine benzyl ester p-toluenesulfonate, 2.1 g., was stirred in 20 ml. of methylene chloride-trifluoroacetic acid (3.2 v/v) containing 1% anisole with exclusion of moisture for 20 minutes. After evaporation, the residue was dissolved in 20 ml. of methylene chloride, filtered and the filtrate was diluted with ca. 50 ml. of ether. A semi-solid separated which failed to crystallize on refrigeration. The supernatant was decanted and ether was added to the residue. Trituration led to crystallization and the product was collected, washed well with ether, then dried in vacuo at 50°C. and at room temperature to yield 1.95 g., [α] D 25 -41.7°C. (c 0.992, ethanol).
Anal. Calcd. for C 20 H 30 N 6 0 6 .CH 3 C 6 H 4 SO 3 H.CF 3 CO 2 H: C, 49.9; H, 5.38; N, 11.9. Found: C, 49.4; H, 5.51; N, 11.9.
EXAMPLE 5: N-Benzyloxycarbonyl-L-prolyl-L-arginine Benzyl Ester p-Toluenesulfonate Methanolate
To a stirred mixture of 6.0 g. (0.0241 mole) of benzyloxycarbonyl-L-proline and 100 ml. of methylene chloride protected from atmospheric moisture was added at ca. 10°C. a solution of 3.3 g. (0.0241 mole) of i-butyl chloroformate in 10 ml. of methylene chloride. This mixture was cooled to -20°C. whereupon a solution of 2.43 g. (0.0241 mole) of N-methylmorpholine in 5 ml. of methylene chloride was added dropwise during 6 minutes, the reaction temperature being maintained between -20°C. to -15°C. Five minutes later, an opaque solution of 15.8 g. (0.0253 equivalent) of L-arginine benzyl ester di-p-toluenesulfonate and 2.56 g. (0.0253 mole) of N-methylmorpholine in ca. 120 ml. of methylene chloride, pre-cooled at -5°C., was added in small portions such that the reaction temperature could be maintained between -15° to -10°C. Stirring and cooling at -15° to -10° C. was continued for two hours, then the reaction mixture was allowed to warm to room temperature and stir overnight. The opaque reaction mixture was washed successively with water, dilute salt solution and saturated salt solution, dried over MgSO 4 , treated with Darco activated carbon and diatomaceous earth and filtered. Removal of solvent from the filtrate in vacuo at >45°C. left 15.7 g. of amber semi-solid mass as the residue which was then chromatographed on a column (2.5 × 60 cm.) of silica gel. The column was eluted successively with methylene chloride (800 ml.), methylene chloride containing 1% (400 ml.), 3% (400 ml.) and 5% (1300 ml.) methanol. Fractions 1-10 (200 ml.) were void of any material. Fractions 11-22 (75 ml.) were examined by tlc (SiO 2 ; 250 μ, n-BuOH:AcOH:H 2 O,3:1:1). Fractions 15-19 were homogeneous (R f 0.76, I 2 sensitive) and yielded, after evaporation, a total of 4.6 g. (fractions 14, 20, 21 and 22 were slightly contaminated, yielding 2.8 g. after evaporation). [α] d 25 -43.3°C. (c 1.20, ethanol). Nmr (DMSO-d 6 ): -1.75 (cluster, ##EQU4## in Pro and Arg), -2.08 (singlet, --OH of methanol), -2.19 (singlet ##SPC6##
-3.08 (cluster, ##EQU5## in Pro and Arg), -3.35 (singlet CH 3 OH), -4.28 (cluster, α-methinyl H's in Pro and Arg), -5.03 and -5.13 (benzyl --CH 2 --'s). -7.16 and -7.58 (doublets of p-toluenesulfonic acid ring protons superimposed over some --N--H's), -7.38 (singlet, benzyl rings', protons) ppm (TMS).
Anal. Calcd. for: C 26 H 33 N 5 O 4 .C 7 H 8 SO 3 .CH 3 OH: C, 59.7; H, 6.63; N, 10.2; S, 4.69. Found. C, 59.2; H, 6.48; N, 10.3; S,4.46.
The compounds of this invention are useful as anticoagulants, since they inhibit thrombin which they bind. Their anticoagulant activity was determined by measuring thrombin time (TT) utilizing an in vitro test wherein exogenous thrombin is added to oxalated plasma and clotting time is measured in the presence of the test compound. The plasma recalcification time (PRT) was also used in an in vitro test for measuring thrombin inhibition wherein exogenous calcium ions were added to oxalated plasma (the system makes its thrombin in situ), and measuring clotting time in the presence of the compounds.
Following Table I presents in vitro thrombin times for the dipeptide and tripeptide compounds of this invention as compared with the known anticoagulant TAME at the indicated peptide concentrations with the indicated conventional clotting mixture.
TABLE I__________________________________________________________________________In Vitro Thrombin Times.sup.a for Gly-Pro-Arg and Pro-Arg Derivatives Thrombin Times (sec) at Peptide Concentrations (mg/ml)Peptide 0.125 0.25 0.5 1.0 2.0__________________________________________________________________________Control 15 sec 0 0 0 0 0Boc-Gly-Pro-Arg-OBzl.TsOH (Ex. 3) 23 29 42 56 75Gly-Pro-Arg-OBzl.TsOH.CF.sub.3 CO.sub.2 H (Ex. 4) 19 26 44 68 135Boc-Pro-Arg-OBzl.TsOH.MeOH (Ex. 1) 40 44 73 91 159Pro-Arg-OBzl.TsOH.CF.sub.3 CO.sub.2 H (Ex. 2) 19 23 31 46 69Tos-Arg-OMe (TAME) 24 30 39 68 87__________________________________________________________________________ .sup.a Clotting mixture: 0.2 ml. oxalated dog plasma, 0.1 ml. barbital buffer containing peptide and 0.1 ml. thrombin (1 unit/ml.) Boc = t-butyloxycarbonyl TAME = tosylarginine methyl ester hydrochloride Bzl = benzyl
In the following Table II, PRT (average) for each of the compounds of this invention as compared with TAME anticoagulant are given in seconds.
TABLE II______________________________________In Vitro Thrombin Times, Comparisons with TAMEConc. TestCompoundmg/ml→ 0.25 0.5 1.0 1.5 2______________________________________Boc-Gly-Pro-Arg-OBzl.TsOH.sup.(a) (Example 3) 88 110 146 202TAME 105 120 176 203 230Control 66 sec.H-Gly-Pro-Arg-OBzl.TsOH.CF.sub.3 CO.sub.2 H.sup. (a) (Example 4) 77 100 198 246 296TAME 96 123 168 220 273Control 55 secBoc-Pro-Arg-OBzl.TsOH.MeOH.sup.(a) (Example 1) 128 160 207 229 250TAME 105 120 176 203 230Control 66 secH-Pro-Arg-OBzl.TsOH.CF.sub.3 CO.sub.2 H.sup.(a) (Example 2) 89 102 134 209 --TAME 105 120 176 203 230Control 66 secZ-Pro-Arg-OBzl.TsOH.MeOH.sup.(b) Example 5) 240 270 345 -- 435TAME 188 210 240 -- 285Control 115 sec.______________________________________ .sup.(a) Clotting Mixture: 0.2 ml. oxalated dog plasma 0.1 ml. Barbital buffer saline containing test compound 0.1 ml. CaCl.sub.2 0.025 M Z = benzyloxycarbonyl Bzl = benzyl TsOH = p-toluenesulfonic acid .sup.(b) Clotting Mixture: 0.1 ml. oxalated dog plasma 0.2 ml. Barbital buffer saline containing test compound 0.1 ml. CaC1.sub.2 0.025 M
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Fibrinogen peptide derivatives which have biological activity as anticoagulants of blood having the dipeptide moiety prolylarginine or the tripeptide moiety glycylprolylarginine, e.g., L-prolyl-L-arginine benzyl ester p-toluenesulfonate trifluoroacetate, glycyl-L-prolyl-L-arginine benzyl ester p-toluenesulfonate trifluoroacetate, N-t-butyloxycarbonyl-L-prolyl-L-arginine benzyl ester p-toluenesulfonate methanolate, N-benzyloxycarbonyl-prolyl-L-arginine benzyl ester p-toluenesulfonate methanolate and N-t-butyloxycarbonylglycol-L-prolyl-L-arginine benzyl ester p-toluenesulfonate.
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FIELD OF THE INVENTION
The present invention relates to propellant systems and more particularly, but without limitation thereto, to a chemical bonding system for bonding a solid propellant to its inhibitor sleeve that may be used in gas generators for missile systems.
BACKGROUND OF THE INVENTION
Modern guided missiles need high performance gas generators for providing high pressure and temperature gases to control nozzles of post boost control systems and the like. This provides gas energy to achieve forward, reverse, pitch, yaw and roll thrust control of the missile equipment and re-entry body sections. Prior art techniques have not provided the high performance required for advanced weapon systems that must undergo severe operating environments and have longer term burn requirements for high pressure and temperature gases. Moreover, modern weapon systems often have long storage life requirements wherein propellants that have excessively aged, for example, may be easily replaced with a fresh propellant contained in an inhibitor sleeve that forms part of a replaceable propellant grain assembly. This requires repeatable close tolerances, long term dimensionable stability and inhibitor to propellant bonding that will withstand long duration, high temperature and pressure conditions. These and other requirements have been accomplished by the solid propellant to inhibitor bonding system of the present invention.
OBJECTS OF THE INVENTION
An object of the present invention is to provide a solid propellant to inhibitor bonding system for use in replaceable propellant grain assemblies.
A further object of the present invention is to provide a cost effective, efficient and reliable propellant to inhibitor chemical bonding system.
SUMMARY OF THE INVENTION
These and other objects have been demonstrated by the propellant to inhibitor bonding system of the present invention which is used with an inhibitor sleeve that has one end attached to an end closure having interior insulation, made of the same rubber insulation material as the inhibitor, and forming a cylindrical cavity for receiving a poured propellant mix. The bonding system of the present invention is employed prior to pouring the propellant mix. This bonding system involves cleaning the interior surface of the cavity with freon solvent and brush applying a barrier coat, comprising an epoxy resin with amine curing agents, to the interior surface of the cleaned inhibitor. The barrier coat is then cured and a liner is then brush coated onto the cured interior surface of the barrier coat. The liner is then cured and the propellant is then cast into the cavity formed by the lined inhibitor sleeve and insulated closure. It is important that the polymer and curing agent of the propellant and liner be the same to assure optimum compatibility, effective adhesion and bonding. This is accomplished by providing common chemical constituents even though they are formed by different processes and have other different chemical constituents. All of the above described characteristics have been achieved by the propellant to inhibitor bonding system of the present invention which will be described in detail with reference to the accompanying tables and drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is an overall side elevation view of the gas generator assembly which employs the propellant to inhibitor bonding system of the present invention.
FIG. 1A is a sectional view of the forward section of FIG. 1.
FIG. 2 is a sectional-view of the aft end of the solid propellant grain assembly.
FIG. 3 is a burn-back pattern of the grain.
FIG. 4 is a cross-sectional view of the propellant grain assembly and the forward closure assembly.
GLOSSARY
The following is a glossary of elements and structural members as referenced and employed in the present invention.
11 gas generator
13 propellant grain
15 inhibitor
17 internal insulation
19 case
21 external insulation
23 internal insulation
25 forward closure
27 external insulation
29 gas outlet assembly
30 igniter
31 cylindrical cavity
34 thickened forward section of case 19
35, 37, 39, 41 attachment lugs
43 thickened section of forward enclosure 25
45 o-ring groove
47 annular retaining key groove
49 handling holes
51 retaining key
53 o-ring
79 exposed aft section of the grain
81 inhibitor after casting but before machining
82 interface between the exterior cylindrical surface of the inhibitor 15 and the internal insulation 17
83 position of surface of grain after casting but before machining
85, 87, 89 annular concentric grooves
91 flat face of grain
93, 95 chamferred faces of grain
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring now to the drawings wherein like reference numerals are used to designate like or corresponding parts throughout the various figures thereof, there is shown in FIG. 1 a side elevation sectional view of the gas generator assembly of the present invention as indicated by reference numeral 11. FIG. 1A shows a sectional view of the forward end of the generator of FIG. 1.
Gas generator 11 includes propellant grain 13, inhibitor 15, internal insulation 17, case 19, external insulation 21, gas outlet assembly 29, and igniter 30. The forward section shown in FIG. 1A includes internal insulation 23, forward closure case 25 and external insulation 27.
The propellant grain assembly 32 shown in FIG. 4 comprises cylindrical inhibitor 15, solid propellant grain 13 and forward closure 24, also shown in FIG. 1A. Forward closure assembly 24 includes forward closure 25, internal insulation 23 and external insulation 27 attached thereto.
Case 19 of is of cylindrical configuration with an integral aft dome section, a thickened forward section 34 as shown in FIG. 1A and attachment lugs 35, 37, 39, and 41. Forward closure 25 has a domed configuration, thickened section 43, o-ring groove 45, retaining key groove 47 and four handling holes 49. The forward closure is attached to the case with a retaining key 51 and is sealed by means of o-ring 53.
The propellant grain is made from a hydroxyl terminated polybutadiene polymer propellant with HMX solid particles used as an oxydizer (HTPB/HMX) composite propellant with flame temperature of about 3,000° F. The propellant weight is approximately 250 pounds and is a cast-in-sleeve configuration having a length of about 29 inches and a diameter of about 13 inches. The grain is an end burning design with a configured start up surface for added initial burn area and uniform flame front propagation.
Interface 82 between the exterior cylindrical surface of the inhibitor and the interior cylindrical surface of the gas generator, as shown in FIG. 1A, is an interference fit that requires maintaining a very close dimensional tolerance of the diameter of the inhibitor under severe mechanical and thermodynamic conditions. (An interference fit has no clearance.) This requires an extremely effective bond between the propellant 13 and inhibitor 15. In addition, during operation there is propellant burn-back from the aft end of the inhibitor. The peripheral end seal between the propellant and inhibitor is critical because a break in the seal will result in undesirable burning along the radial surface and not the end. This also requires an extremely effective bond between the propellant and inhibitor. An interference fit also maximizes propellant weight and assures mechanical integrity.
The propellant grain assembly is loaded and unloaded by cooling the grain assembly to provide necessary clearance between the inhibitor and insulator and then subjected to normal temperature conditions where the interface has an interference fit.
FIGS. 2 and 4, show propellant grain 13 and inhibitor 15 of propellant grain assembly 32. Between the grain 13 and inhibitor 15 and between the grain and the forward closure assembly 24 is an adhesive bonding system for interconnecting the grain, inhibitor and forward closure assembly. The method of manufacture is to pour the propellant and machine the exposed aft section 79 (see FIG. 2) after the propellant has been cured. This is accomplished by using an elongated inhibitor, as shown by dotted line 81 in FIGS. 2 and 5, and pouring the propellant into the assembly in the vertical position. The cavity is filled with propellant to the position shown by dotted line 83 and allowed to cure. The propellant and inhibitor are then machined as shown and described below.
System operation consists of meeting ignition characteristics and a flow rate range for a given pressure range dictated by missile requirements. This is accomplished by the unique design of the aft grain configuration which defines the initial burn area. From FIGS. 2 and 4, it can be seen that the grain includes annular concentric grooves 85, 87 and 89, flat section 91 and chamfer sections 93 and 95. The configuration of these grooves, flat section and chamfers along with the tapered grain diameter together define an initial burn area that results in appropriate burn progression. The design considerations include clearance for thermal expansion during storage and operation, clearance for the igniter diffuser mounted in the case, maximizing propellant weight, optimizing surface area progression, ease of manufacture, and a configuration that assures grain ignition and burn progression as shown in FIG. 3. Grooves 85, 87 and 89 provide the required additional initial surface area to overcome system heat losses and achieve proper initial operating pressures.
Table I shows the characteristics of the propellant grain 13 of FIG. 6 for a HTPB/HMX grain material, flame temperature 3,000° F., and grain weight 232 pounds.
TABLE I______________________________________Grain dimensions (inches)______________________________________ d.sub.1 13.0 d.sub.2 12.12-12.04 d.sub.3 9.82-9.78 d.sub.4 9.25-9.21 d.sub.5 7.42-7.38 d.sub.6 6.79-6.75 d.sub.7 5.44-5.36 d.sub.8 2.42-2.38 d.sub.9 14.25 d.sub.10 13.46-13.42 d.sub.11 13.60-13.56 d.sub.12 13.67-13.63 r 0.110-0.090 l 29.0 l.sub.1 1.16-1.13 l.sub.2 1.94-1.91 l.sub.3 8.29-8.27 l.sub.4 3.01-2.99______________________________________
Slot 87 shown in FIG. 2 provides proper burn pattern and clearance for the diffuser of the igniter assembly under highest temperature storage conditions when the propellant grain expands in the longitudinal direction. The radial interface between the exterior surface of the inhibitor and the interior surface of the insulator is an interference fit having no clearance. This is done to maximize propellant weight and to eliminate separation of the inhibitor and the propellant grain. Elimination of this separation is critical to prevent propellant burn-back in the interface between the grain surface and the inhibitor. The propellant grain assembly is loaded and unloaded by cooling the grain assembly to provide the necessary clearances between the inhibitor and insulator and then subjecting the propellant grain to normal temperature conditions which expands the grain to form an interference fit.
The forward closure assembly includes titanium forward closure 25, internal insulation 23 and external insulation 27. The forward closure assembly is attached to the forward end of inhibitor 15 by means of an epoxy adhesive, for example. Between the outer surface of the forward closure 25 and inner surface of inhibitor 15 and between forward end of closure 25 and the interior surface of interior insulation 23 is the epoxy adhesive bonding system of the present invention. Although performing different functions, inhibitor 15 and internal insulator 23 are made of the same rubber type material as defined below. The overall method of manufacture is to assemble the inhibitor 15 and forward closure assembly 17 to form a cylindrical cavity. The chemical bonding system materials are applied to the interior surfaces of the cavity and propellant is then poured into the cavity. This is accomplished by using an elongated inhibitor 81 and pouring the propellant into the vertically positioned cylindrical cavity 31 as shown in FIG. 2. The propellant and inhibitor interconnected by the bonding system of the present invention are then machined with concentric grooves 85, 87, 89 and surfaces 91, 93, and 95 as shown in FIG. 2.
The constituents and process of the propellant to inhibitor bonding system of the present invention are as follows:
(1) The above described inhibitor and forward closure assembly (which contains insulation 23 bonded to forward closure 25) are assembled and placed into casting tooling. The inhibitor 15 and interior insulation 21 are made of the same material and generally comprise an ethylene propylene, diene monomer (EPDM/neoprene rubber binders containing silica powder and aramid fibers.) The specific chemical composition is set forth in Tables II and III as follows:
TABLE II__________________________________________________________________________(Chemical Composition) By Weight Composition in Parts per 100 Parts of Rubber Binder (PHR)Function Ingredient Minimum Maximum Nominal__________________________________________________________________________Binder EPDM Elastomer 79.0 81.0 80.0 2 Chlorobutadiene 19.0 21.0 20.0 1,3 ElastomerFiller Silica Hydrate 29.0 31.0 30.0Antioxidants Polymerized Trimethyl 1.9 2.1 2.0 Dihydroquinoline Alkylated Diphenylamines and 0.9 1.1 1.0 Diphenyl-P-PhenylendiameneCuring Agent 40% a,a' Bis (Tert-Butylperoxy) 5.5 5.7 5.6 DiisopropylbenzeneProcessing Aids Napthenic Process Oil 4.9 5.1 5.0 Synthetic Polyterpene Resin 4.9 5.1 5.0Fiber Aramid Fiber (.25 inch) 27.0 29.0 28.0Activator Zinc Oxide, Technical 4.9 5.1 5.0__________________________________________________________________________
TABLE III__________________________________________________________________________(Functional Description of Ingredients)Ingredient Description__________________________________________________________________________EPDM Elastomer EPDM elastomer; binder also adds chemical bond sites2 Chlorobutadiene 1,3 Elastomer Choroprene elastomer added to improve processing and bondingSilica Hydrate Mineral filler to improve thermal properties (mixing and packing)Polymerized Trimethylquinoline Polymerized trimethylquinoline antioxidant prevents aging degradation of the polymer chainAlkylated Diphenylamines and Diphenylamine; antioxidant used in combinationDiphenyl-p-Phenylendiamene with above for high temperature storage conditions40% a,a' Bis (Tert-Butylperoxy), 40% active peroxide supported on BurgessDiisopropylbenzene (curative) KE clay; curative for both polymers also provides aging stability as compared to Sulfer, for example.Napthenic Process Oil Lubricating oil; improve mixingSynthetic Polyterpene Resin Tackifier added to improve green tack (adhesion between uncured layers)Aramid Fiber (.25 inch) Aramid fiber reinforcement; improved char retention and thermal propertiesZinc Oxide Activator for curing agent__________________________________________________________________________
The following are the process steps used to prepare the uncured thermal insulation and inhibitor composition.
(1) The initial batch includes mixing the binders, antioxidants, processing aids and catalyst. A Banbury mixer is used for approximately 2 minutes.
(a) The fiber filler is then mixed with the step (I) constituents. A Banbury mixer is used for three submixes each for approximately one minute.
(b) The curative is then mixed with the step (2) constituents. A Banbury mixer is used for approximately one minute to form a slab about 4 inches thick, one foot wide and from one to two feet long.
(c) The mixed slab of step (3) is then calendered to about 0.1 inch thick.
(d) The calendered material of step (4) is then remixed in a Banbury mixer for about one minute to form a mixed slab as defined in step (3).
(e) The mixed slab of step (5) is then calendered to about an 0.1 inch thick sheet having a 4 foot width.
(f) A thin plastic cover sheet is applied to one surface of the step (6) uncured insulation sheet and rolled for subsequent use.
(g) When used; the uncured insulation is cut to proper configuration; the configured insulation is laid up and the plastic sheet is removed. If additional insulation thickness is required another piece of uncured insulation is cut to proper configuration and laid up against the first uncured insulation sheet and the plastic sheet is removed. The first and second sheets are tacky and are pressed together to form contiguous insulation sheets. The process is repeated until the total desired uncured insulation thickness is achieved.
(h) The uncured insulation of step (8) is then cured by subjecting it to elevated temperatures wherein the time and temperature is dependent upon the total thickness of uncured insulation. The inhibitor sleeve has a nominal thickness of about 150 mils, a length of about 30 inches and a diameter of about 13 inches.
(2) The inner surface of the cavity formed by inhibitor sleeve 15 and insulator 23 is cleaned with a methyl ethyl ketone (MEK) dampened lint free cloth and is then dried for at least 60 minutes.
(3) A barrier coat is then brush applied to the interior surface of the cleaned cavity. The barrier coat is an epoxy resin with amine curing agent, such as Scotchcast-8™ (made by The Minnesota Mining and Manufacturing Co.). The barrier coat is brush applied to a nominal weight of about 0.35 pounds or about 3-4 mils thickness.
(4) The barrier coat is then cured wherein the cure time and temperature is 24 hours minimum at 60° to 90° F. plus 1 hour minimum at 170°±5° F.
(5) A liner is then brush coated onto the cured interior surface of the barrier coat. The inhibitor sleeve and forward closure are preheated to 170° F. for 2 to 6 hours prior to liner application. The liner is applied in two brush coats and has a final nominal weight of about 0.25 pounds or 2-3 mils. thickness. The chemical composition of the liner is carbon black, isophorone diisocyanate liquid, polybutadiene liquid hydroxyl terminated (type II), and ferric acetylacetonate. The mixing process of the uncured liner material is as follows:
(a) Add polybutadiene liquid hydroxyl terminated (type II) and ferric acetylacetonate to mixer and blend 1 hour minimum at low speed with mix temperature 160°±10° F. Cool to 90°±10° F. before further processing.
(b) Add isophorone diisocyanate and blend 10 minutes minimum at low speed.
(c) Screen carbon black through a 100 mesh screen using Ro-Tap with approximately 5 mm diameter glass beads. Add approximately 1/3 of the carbon black to mix and blend for 10 minutes minimum at low mixer speed. Repeat mixing step for each of the two remaining portions of carbon black.
(d) When all ingredients have been added and mixed, run mixer at low speed for 60 minutes minimum under vacuum of 25 inches of mercury minimum. Mix temperature shall not exceed 90° F. Break vacuum with nitrogen or argon.
(e) Clean storage cans and lids with solvent and allow to air dry. Transfer mix to 1 quart can, and 1 pint can. Purge cans with nitrogen or argon before filling. After filling, flush with nitrogen or argon before installing lids.
(f) Store in deep freeze at 0°±10° F. for one (1) year.
(6) The liner is then cured for a total time of 72 to 96 hours at a temperature of 170° F.±5° F. If propellant casting operations are not to begin immediately purge with nitrogen and seal. The lined assembly may be stored up to 2 weeks maximum before casting at 60° to 90° F.
(7) The propellant is manufactured and then cast into the lined cavity. The propellant materials are cyclotetramethylenetetranitramine, i.e, HMX (class I), carbon black, isophorone diisocyanate, and polybutadiene liquid hydroxyl terminated (type II).
(a) The mixing process of the uncured propellant begins by adding the polybutadiene liquid hydroxyl terminated (type II) and the carbon black to mixer. The carbon black shall be added within 4 hours maximum of removal from "in use" storage. Blend the ingredients for 5 minutes at atmospheric pressure and then under vacuum for 15 minutes at a minimum vacuum of 28 inches of mercury. The vacuum shall be broken with nitrogen. While mixing, add ground Class 1 HMX utilizing a vibrating feeder. This mixing shall be for a minimum of 40 minutes at atmospheric pressure. While mixing, add the unground Class 1 HMX utilizing a vibrating feeder. This mixing shall be for a minimum of 45 minutes at atmospheric pressure followed by blending for a minimum of 1 hour at a minimum vacuum of 28 inches mercury. Vacuum shall be broken with nitrogen.
(b) Remove sample for moisture analysis and total solids test.
(c) Add IPDI, mix 10 to 12 minutes, at atmospheric pressure. Blend under vacuum at a minimum vacuum of 28 inches of mercury for 90 minutes. During the final mixing, the mixer shall be run at its slowest speed and the water jacket temperature adjusted to yield a final mix temperature of 140°±5° F. Break vacuum with nitrogen. The propellant shall be cast within 10 hours maximum upon completion of mixing.
(d) The casting process of the uncured propellant begins by preheating the casting hardware assembly 2 to 6 hours at 170°±10° F. prior to casting if not already hot from the liner cure.
(e) The hopper shall be loaded with propellant and replenished as necessary during casting. The hopper water jacket temperature is maintained at 140°±10° F. and relative humidity is maintained at 30 to 60% during casting.
(f) Evacuate the inhibitor sleeve/closure assembly to a pressure of not less than 5 mm of mercury. Close off vacuum line to inside of inhibitor sleeve, but maintain vacuum on outside of inhibitor sleeve to prevent sleeve from collapsing during casting. Open hopper valve to allow propellant to flow into inhibitor sleeve, allowing pressure in the sleeve to be not more than 20 mm of mercury until the propellant level is approximately 1 inch from bottom of casting tooling "clamp" ring, discontinue breaking vacuum and add propellant to obtain correct height of maximum of 2 inches from bottom of "clamp" ring. Close hopper valve and break vacuum. Remove casting hopper and measure propellant level. If insufficient propellant, replace casting hopper, evacuate the sleeve to a pressure of not more than 120 mm of mercury and cast additional propellant. Release vacuum on inside of sleeve first, then release vacuum on outside of sleeve.
(g) The propellant is then cured, thereby bonding the propellant to liner inhibitor 15, by sealing the end of the casting cylinder and applying nitrogen gas at a pressure of 40±5 psig for the first 60 hours minimum of cure. The propellant shall be cured for a total time of 140 to 164 hours at 170° F.±5° F. Total deviations from propellant cure temperature totaling one hour are permitted provided that the excursion temperatures are greater then 40° F. and less than 200° F. Total deviations in excess of one hour and less than 12 hours are permitted provided the excursion temperatures are greater than 130° F. and less than 90° F. The total propellant cure time is to be extended by the total time of propellant cure temperature excursion below 165° F.
(h) The nitrogen gas shall be released and the grain assembly allowed to cool 1 hour minimum after cure.
After the above described manufacturing and curing process the assembly is then machined as previously described and as shown in the FIG. 4.
Because of the severe temperature, time, pressure and load conditions put on a gas generator of the type described it is critical that the metal case to non-metal bonding system be effective under adverse conditions. The present invention provides such a bonding system the details of which are as follows:
(1) The titanium case (6AL-4V) is sandblasted with a 180 grit aluminum oxide abrasive to a surface roughness not to exceed 125 microinches.
(2) The interior sandblasted surface is then cleaned by using a lint free cloth dampened in methyl ethyl ketone (MEK) solvent.
(3) A corrosion resistant coating, such as Chemlok 205™ (rubber to metal adhesive primer made by Lord Chemical Products), is then applied by brush application and having a nominal thickness of 1-2 mils. Chemlok 205™, for example, is a chlorinated resin and phenolic blend in 79% solvent with 5% titanium dioxide and 1% zinc oxide.
(4) The Corrosion resistant coating is then air dried at ambient temperature and atmosphere for at least 60 minutes.
(5) A metal to rubber adhesive coating, such as Chemlock 252™, is then applied by brush application and leaving a nominal thickness of 1-2 mils. Chemlock 252™, for example, is a chlorinated resin with EPDM rubber curing agent.
(6) The adhesive coating is then air dried at ambient temperature and atmosphere for at least 60 minutes.
(7) Uncured insulation material is then laid up against the interior surface of the air dried adhesive coating. Several layers are used until the desired insulation characteristics (defined by thickness or weight) are achieved. Each layer adheres to the next since the uncured material is tacky. Between each layer a vacuum bag is inserted and a vacuum is pulled between the bag and the insulation material to attach adjacent layers of material. The insulation material preferable has plastic backing for storage and handling purposes.
A specific example of the lay-up process for the sheets of uncured insulation is as follows:
1. For the metal aft dome insulation cut five patterns, four patterns of approximately 0.100 inch thick and 1 additional pattern (thickness as required of insulating material). Pattern sizes are nominal in inches as follows:
TABLE IV______________________________________Pattern OD ID Thickness______________________________________1 14.60 2.670 .1002 14.60 2.425 .1003 14.70 2.290 .1004 14.75 2.155 .1005 14.80 2.030 As required______________________________________
2. For the metal case insulation cut five patterns of approximately 0.100 inch thick insulating material. Pattern sizes are nominal in inches as follows:
TABLE V______________________________________ LengthPattern Width Bottom Top______________________________________1 26 13/16 451/4 451/22 25 45 44 11/164 251/2 431/4 433/45 61/2 421/4 421/2______________________________________
The grain direction of the insulation material shall run axially with the motor case.
3. Lay dome patterns on table and clean top side with MEK and allow to air dry 10 minutes minimum.
4. Place patterns 1 and 2 clean sides mating into a dome preform fixture. Leave plastic backing on the outsides.
5. Place patterns 3 and 4 in similar condition. Remove plastic backing from outside of pattern 4 and clean with MEK. Allow to air dry 10 minutes minimum. Place pattern 5, clean, unprotected side on pattern 4. Leave plastic backing on outsides of patterns 3 and 5. Place patterns into a dome preform fixture.
6. Place mold assembly into a press and pressurize to 5-8 tons for 5-8 minutes minimum. Allow insulating material to stay in mold until needed.
7. Remove dome insulation from fixture. Remove the plastic backing and clean with MEK. Allow to air dry 10 minutes minimum.
8. Place pattern into the case first, locating the edge the distance from case retaining key groove. Smooth the pattern against the inside of case. Wipe the pattern surface with MEK and allow to air dry 10 minutes minimum. Filtered circulating air is to be used for approximately 2 minutes.
9. Install conventional cure ring in case. Install an oven film bag and fasten to cure ring with vacuum sealer or equivalent. Attach vacuum lines to fittings on cure ring and elbow connector and pull vacuum (24 inch Hg) for 10 minutes minimum.
10. Remove cure ring, oven film bag and vacuum lines. Cure ring may be left in place.
11. Install two ply dome insulation piece into case. Align insulation hole with entrance to outlet.
12. Pull vacuum per Steps 9 and 10.
13. Install remaining dome insulation piece into case per steps 11 and 12.
14. Install remaining patterns individually per steps 9 and 10.
15. Using new O-rings, install case cure ring into end of case and install conventional retaining key cure plug. Place teflon glass fabric on dome and side wall full length. Install cure bag into gas generator case. Secure cure bag to cure ring with rubber strip and hose clamp. Remove gas generator case assembly from handling fixture and place on cart and secure. Install ortman key plug and apply vacuum sealer or equivalent to all sealing areas of case.
16. Pull vacuum of 24 inches Hg for 30 minutes minimum. Ensure that cure bag has all the wrinkles out, is seated correctly and there are no leaks. This step may be performed after installation into an autoclave but prior to the start of the heating of the autoclave.
17. Move case to the autoclave. Place gas generator case on cure cart and install in autoclave.
18. The insulation, adhesive and casing are now cured which results in a bonding between the case and insulation. A specific example of the autoclave curing process is as follows:
(a) Attach vacuum line from pump to vacuum fitting on case outlet.
(b) With assembly under a vacuum of 24 inches of mercury minimum, start heating autoclave to 160° F.±10° F. and maintain for 2.0-3.0 hours at temperature.
(c) Start air compressor and pressurize assembly to 125-145 psig and increase the temperature to 195° F.±10° F. Maintain temperature and pressure for 1.5-2.0 hours.
(d) Increase autoclave temperature to 325° F.±10° F. and maintain for 3.5-4.0 hours. NOTE: Any deviation from the required temperature tolerance of 10° F. or less for a total of 15 minutes or less will be acceptable as long as the actual cure time to the required temperature is within the required cure time tolerance except when the temperature deviates above the temperature requirement.
(e) Maintain 125-145 psig until autoclave temperature reaches 150° F. This cool down period shall not be less than 30 minutes.
(f) Release pressure, remove assembly from autoclave and allow to cool to ambient.
(g) Remove all fittings, cure bag, and glass fabric from gas generator case. Clean case as necessary using MEK.
19. After the completion of step 18 the interior surface is machined to final dimensions for receiving the propellant grain assembly.
This invention has been described in detail with particular reference to a certain preferred embodiment, but it will be understood that variations and modifications can be effected within the spirit and scope of the invention.
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A solid propellant to inhibitor bonding system for use in replaceable prolant grain assemblies is used with an inhibitor sleeve that has one end attached to an end closure having interior insulation, made of the same rubber insulation material as the inhibitor, and forming a cylindrical cavity for receiving a poured propellant mix. The bonding system is employed prior to pouring the propellant mix. This bonding system involves cleaning the interior surface of the cavity with freon solvent and brush applying a barrier coat, comprising an epoxy resin with amine curing agents, to the interior surface of the cleaned inhibitor. The barrier coat is then cured and a liner is then brush coated onto the cured interior surface of the barrier coat. The liner is then cured and the propellant is then cast into the cavity formed by the lined inhibitor sleeve and insulated closure. It is important the the polymer and curing agent of the propellant and liner be the same to assure optimum compatibility and effective adhesive bonding. This is accomplished by providing common chemical constituents even though they are formed by different processes and have other different chemical constituents.
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FIELD OF THE INVENTION
This invention relates to the art of pipelines, and specifically, pipelines which are buried in underground trenches along their length.
BACKGROUND OF THE INVENTION
Pipelines are used to transport fluids, typically oil, gas and other petroleum products, across long distances. In the current art of installing new pipelines, the pipe is lowered into trench and laid on top of the support benches, which are spaced along the length of the trench floor. The trench containing the newly laid pipe is then backfilled normally in two stages. A layer of uniform, rock-free subsoil is introduced into the trench so that it flows around and beneath the pipe between the spaced support benches, fills up the open area between the sides of the pipe and the trench walls, and covers the pipe to a specified height over the pipe. In the art this procedure is termed “pipeline padding” or “padding”. The second backfill stage is to then utilize the remaining spoil previously excavated from the trench to complete the trench backfill. After the backfilling is completed, a hydrostatic test is conducted. The pipe is filled with water and placed under high pressure for a period of time, usually 24 hours, in which the pressure is monitored and the pipe section is tested for leaks.
After the pipeline has been installed and hydrostatically tested an additional test is conducted. Devices called “sizing pigs” are sent through the pipe. It is during this procedure that damage to the pipe is found and identified. All dents and buckles as well as most “out-of-round” sections must be dug up and repaired before the pipeline can be placed into service. This repair work is very expensive and time consuming. The support benches hold the pipeline above the trench floor both during backfilling and while the pipe is in service. Because rocks on the trench floor may dent the pipe or damage the protective coating on the outside of the pipe, it is very important that the pipe does not come into contact with the trench floor during service as well as during installation. Sandbags are commonly used as support benches. These bags are can be stacked to any desired height. Another popular bench material is high density foam blocks. These blocks are strong enough to support the pipeline without collapsing. U.S. Pat. Nos. 4,068,488 to. Ball discloses the use of inflatable support pads that temporarily support the pipeline during backfilling. These bags are removed as the backfill material approaches the bag during backfilling. The patent calls for a granular bedding/padding material to be forcibly injected under the pipe to obtain full compaction. The bedding, being fully compacted prior to the removal of the temporary pad, will then support the pipe at the same pipe position. U.S. Pat. Nos. 4,488,836 and 4,806,049 to Cour disclose the use of bags filled water to install pipeline in ocean bottoms or trenches that are not stable. The purpose of which is to keep the trench walls from collapsing before the pipe can be installed. The pipe is then laid on top of the pressurized bladder which has filled the trench. The bladder is then deflated allowing the pipe to drop down to the unpadded trench floor while, as the pipe is being lowered, the unstable trench walls would collapse inward on top of the pipe. All three patents teach that the pipe is placed on the filled bag or bags, and then the bag is deflated, allowing padding or the bottom of the trench material to support the pipe. Each bag has a valve that is opened to allow deflation. Such air filled and water filled bags are more expensive than sandbags and foam blocks. Consequently, they are seldom used.
To insure that the pipe support benches perform the function of supporting the pipe above the trench floor for operating pipelines, it will be apparent to one of skill in the art that the benches must be constructed to be strong enough and be spaced close enough together so that the benches can adequately support more than the weight of the actual pipe itself. After the support benches are placed along the trench floor they will be subjected to the accumulative loads of the pipe itself, the fill material and the contents of the pipe.
FIG. 1 shows a typical pipeline installation of the prior art before backfilling. The pipeline 12 is supported on spaced apart benches 13 placed on the floor of a trench 14 . For illustrative purposes, consider a steel pipe 36 inches in outer diameter with a wall thickness of 0.500 inches and with support benches located at 15 foot intervals along the trench floor, as shown in FIG. 1 . When the pipe is laid on top of the spaced support benches, each support bench will experience a load of 2,860 pounds, assuming each bench will support an equal weight. As the trench is backfilled, the support benches will experience additional loading above the weight of the pipe alone. For the purposes of this example, we can estimate the additional loading during backfill to approximate ½ of the weight of the pipe. Employing this approximation, each bench will now experience a load of 4,290 pounds, again assuming each bench will support an equal weight. After the trench has been backfilled, the pipe is then filled with water and hydrostatically tested. In this example and again assuming equal bench weight distribution, each support bench will experience an additional load of 6,250 pounds for a total weight of approximately 10,540 pounds.
In the above example, dynamic loading has been ignored and it was assumed that each bench will experience equal loading. In the actual practice of installing pipelines, however, dynamic loading and unequal bench loading can exist. For example, if the bottom surface of a section of pipe does not align with the surface of the trench floor, it may be possible for individual support benches to experience increased loading several times as great as those shown in the above example. In FIG. 2, the bottom surface of the pipe 12 is shown to be out of alignment with the trench floor. As a result, support benches 1 and 4 are supporting the entire weight of the pipe section and the pipe is suspended above support benches 2 and 3 . Support benches 1 and 4 are therefore supporting approximately twice the weight that would otherwise be supported had non-alignment not occurred. Pipeline installers are supposed to carefully observe pipeline installation to assure that the pipeline is supported by all of the benches. If gaps are seen like those in FIG. 2 the installer is required to lift the pipeline and insert one or more shims 15 as shown in FIG. 3 . However, it is quite common for the installer to miss or even ignore gaps between benches and the pipeline especially when using expanded polystyrene benches.
With the necessity of insuring that the bottom surface of the pipe does not come into contact with the trench floor, and the risks of expensive pipe damage if it does contact the trench floor, the current method is to provide support benches constructed strong enough to support the entire expected loading calculated as in the above example plus an appropriate safety factor multiplier. Therefore, each bench will support the total weight or loading, namely, the weight of the empty pipe, the weight of the backfill, the weight of the water filled pipe during hydrostatic testing, the dynamic loading, and the increased weight caused by unequal bench loading. However, constructing the support benches rigid enough and placing the benches close enough together to support the total weight or loading as practiced in the current art makes it very likely that the position of the pipe after it has been initially lowered into the trench and placed on the support benches will remain fairly constant. That is, the height of the bottom surface of the pipe above the trench floor when the pipe is initially laid on top of the support benches will remain the same (or very nearly so) throughout the pipeline installation and testing processes.
As previously described, immediately after the pipe has been placed on top of the support benches, rock-free subsoil is introduced into the trench so that it flows around and under the pipe into the open area beneath the pipe between the support benches. Because the support benches have been constructed rigid enough to support the additional loads experienced after the placement of the padding material, the pipe cannot move to a position sufficiently low enough to compact the padding material beneath the pipe. Because the padding material beneath the pipe is not compacted, it will be readily affected by water, thus contributing to the well known problem of padding wash-out. Furthermore, when the padding material is not compacted, the pipe has no additional support after installation. Consequently, the installed pipe is supported by only the support benches themselves. In normal practice, it is not unusual that a typical underground pipeline be actually supported along less than 10 percent of its length. Unequal support bench loading can cause individual or a series of individual benches to be subjected to tremendous loading. Sometimes unequal loading has occurred in the practice of installing underground pipelines to such a degree that individual, or a series of individual benches fail, thereby allowing that particular section of pipe to drop to the trench floor.
Size and costs are other serious concerns with having the support benches constructed to support the total weight or loading on the pipe. It is necessary that these individual benches have a large enough surface area to prevent the pipe from being subjected to resultant point loading sufficient enough to cause the pipe to be flattened or ovalized (out-of-round). Should that occur an expensive dig-up and repair would be necessary.
Consequently, there is a need for a method of installing pipeline that permits installation without resultant uneven loading of support benches and yet is no more expensive or complicated than current installation methods.
SUMMARY OF THE INVENTION
I provide a method of installing pipeline using benches strong enough to support the pipe after the pipe has been lowered into the trench and padded. However, as opposed to the practice of the current state of the art, the benches are constructed to fail when additional cumulative loading produced by complete backfill and hydrostatic testing is applied. This method will accomplish beneficial outcomes not seen in the current art. A pipeline installed according to the present invention will be supported by the padding material beneath the pipe between the benches. As a result, a much greater percentage of the actual pipe will be supported. Further, the padding material beneath the pipe will be compacted, thereby greatly reducing the well-known problem of padding wash-out.
BRIEF DESCRIPTION OF THE DRAWING
FIG. 1 is a diagram showing a pipeline supported by spaced benches according to the prior art
FIG. 2 is a diagram similar to FIG. 1 illustrating the problem of unequal dynamic loading that occurs when the bottom of the pipeline is not aligned with the floor of the excavated trench.
FIG. 3 is a diagram similar to FIGS. 1 and 2 showing a support bench with a shim used to correct the problem shown in FIG. 2 .
FIG. 4 is a perspective view of a support bench according to the present invention in place on a trench floor
FIG. 5 is a perspective view similar to FIG. 4 showing a pipeline disposed on the support bench and compressing the support bench according to the present invention.
FIG. 6 is a perspective view showing the pipeline and support bench of FIG. 5 with padding material added.
FIG. 7 is a perspective view showing the pipeline and support bench of FIG. 6 with complete backfill added, thereby further compressing the support bench.
FIG. 8 is a perspective view showing the support bench fully compressed according to one embodiment of this invention.
FIG. 9 is a perspective view showing the support bench under a condition of structural failure according to a second embodiment of this invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring to FIGS. 5 through 9, I provide a support bench 20 that is cube-shaped or a rectangular solid. If desired, a concave surface can be provided on the top of the bench. Preferably the bench has a height equal to or greater to the distance above the trench floor at which the pipe is to be positioned. Commonly, this distance is 12 inches. For that reason FIG. 4 identifies the height of the bench as 12″, but it should be understood that the bench could be any desired height. Furthermore, although the figures show the pipe being supported by a support bench constructed of a single block at each support location, it should be understood that two or more blocks could be stacked to create a support bench. Unlike the benches of the prior art, bench 20 is constructed and sized to fail at a pre-determined weight loading. This weight will be a function of the material and dimension of the actual pipe, as well as the intended spacing between the support benches.
To install a pipeline in accordance with the present invention the support benches are placed into the trench at spaced apart locations on the trench floor. The pipe is then lowered into the trench and placed on top of the support benches in a manner so as to insure that the support benches will experience little or slight dynamic loading. The previously described condition of unequal support bench loading must be avoided. To prevent unequal bench loading from occurring, it is necessary to employ measures to correct non-alignment. Sections of pipe which do not align with the trench floor will be apparent during the lowering-in of the pipe. The lowering-in operation should be observed and monitored and when it is seen that the bottom surface of the pipe does not come into contact with a particular support bench, the lowering-in operation should be stopped, the pipe should be lifted, and an appropriate size shim should be installed on top of that support bench, as shown in FIG. 3 . This procedure should be repeated throughout the complete lowering operation to make certain that every support bench is providing support to the pipe.
After the pipe has been lowered into the trench and placed on the support benches as described above, padding material is placed into the trench according to conventional practice. However, the padding operation should be closely monitored to insure that padding material completely fills in the open area beneath the pipe between the support benches. To eliminate the possibility of bridging, it is suggested that the padding material be introduced into the trench in such a manner that the padding material flows on both sides of the pipe somewhat equally. That should assure that the padding material enters the open area beneath the pipe from both sides. Furthermore, it is suggested that the padding material also be introduced in such a way that the padding material will be flowing into the area beneath the pipe in a constantly forward direction in a continuous manner. That is, the open area beneath the pipe will be filled in front of and before the padding material builds in the open trench and fills in the area between the pipe and the trench walls. As the padding material is introduced to the trench in this manner, the padding material, as it is building up in the trench, will also flow forward, filling in the open area beneath the pipe first. This procedure will eliminate the possibility of bridging in which case padding material would be prevented from entering the area immediately beneath the pipe, thereby creating “void” areas. In this regard, it has been shown that if padding material is dumped from the side of the trench quickly so that a volume or batch of padding material is introduced suddenly, bridging often occurs. By following this procedure, the pipe will be supported fairly equally by all support benches. Somewhat loose and non-compacted padding material will have filled in the area immediately beneath the pipe, and the pipe will have been prevented from coming into contact with the trench floor.
When the pipe 12 is placed on top of the bench 20 , the resultant load may cause some calculable deformation of the support bench. Further deformation may occur when backfill material is placed on top of the pipe. Consequently, FIGS. 6 and 7 show the height of the support bench that was originally 12″ to be 10″ after placement of the pipe and 9″ after backfilling.
As described previously, the largest load and the largest single increase in loading occurs when the pipe is filled with water for hydrostatic testing. According to a preferred embodiment of this invention, the support benches are to be designed to fail to support this loading. In the installation of 36 inch steel pipe discussed above the bench would be designed to fail when subjected to a weight of 10,540 pounds. It should be noted, however, that the support bench could be designed to fail anytime after the area beneath the pipe has been properly padded. For example, the benches could fail upon placement of the backfill material on top of the pipe. That would be at 4,290 pounds in the example. This allows a load design window in which the support benches are to fail. However, the benches must not fail during the lowering-and pipe placement or during padding operations. The benches may fail or not fail after padding material has been placed under the pipe while the trench backfill is completed. The benches must fail to support the total loading when the pipe is filled with water for hydrostatic testing.
As another example consider a steel pipe 24 inches in outer diameter with a wall thickness of 0.375 inches and with support benches located at 15 foot intervals along the trench floor. When the pipe is laid on top of the spaced support benches each support bench will experience a load of 1,420 pounds assuming each bench supports an equal weight. As the trench is backfilled, the support benches will experience additional loading. For the purposes of this example, we can estimate the additional loading during backfill to approximate ½ of the weight of the pipe. Employing this approximation, each bench will now experience a load of 2,130 lbs., again assuming each bench is supporting an equal weight. After the trench has been backfilled, the pipe is then filled with water and hydrostatically tested. Again assuming equal bench weight distribution, each support bench will experience an additional load of 2,760 pounds for a total weight of approximately 4,890 pounds.
As yet another example, a steel pipe 36 inches in outer diameter with a wall thickness of 0.500 inches is placed on support benches located at 12 foot intervals. Assuming that each bench supports an equal weight, each bench would experience a load of 2,290 pounds when the pipe is placed on the benches. Estimating the backfill as providing half the weight of the pipe, each bench will carry a load of 3,435 pounds after backfilling. When the pipe is filled with water and hydrostatically tested an additional load of 5,000 pounds will be added to each bench. Therefore, the total weight at which the bench should fail is approximately 8,435 pounds.
It is the function rather than the composition of the support benches that is critical. Therefore, those skilled in the art will recognize that many different materials and bench constructions could be used. However, in general, it is contemplated that the support benches may be one of two general designs. First, the support benches may be constructed of a material which would remain rigid and not deform throughout all loading prior to failure. Such a bench may be a rigid homogeneous material such as a high density foam that shatters at a specific load. The bench could be a frame structure in which the top surface that receives the pipe is supported by legs that break or buckle at a specific loading. Preferably, the support benches are constructed of a material which would deform or flatten when subjected to increased loads, while still providing support, prior to failure. One such material would be expanded polystyrene. Support benches constructed of material showing these properties would produce a “soft” support bench versus a “hard” support bench.
FIGS. 4 through 8 show a single soft support bench comprised of a material which would deform or flatten when subjected to increasing loads. In FIG. 4 a single support bench is shown to have a height of 12 inches The actual height of the benches is not germane to this invention, except that it should be sufficient to allow a desired amount of padding material to flow under the pipe. When the pipe is placed on top of the bench, the resultant load will cause some calculable deformation of the support bench. For descriptive purposes, in this example, the support bench has been deformed (flattened) two inches. Hence, FIG. 5 shows the pipe supported 10 inches above the trench floor. After padding material has been placed beneath the pipe, the pipe is still being supported by the support bench 10 inches above the trench floor. At that point there is loose, non-compacted padding material, shown as reference number 24 in FIG. 6, beneath the pipe between the benches. The padding material is providing zero support to the pipe. After the trench has been completely backfilled with fill material 28 the support bench is compressed. Consequently FIG. 7 shows the pipe 12 resting 9 inches above the trench floor. This lowering of the pipe a distance of one inch from the previous FIG. 6 compresses the non-compacted padding material 24 from a depth of 10 inches to a depth of 9 inches and provides a degree of compaction producing some support to the pipe by the padding material. The support benches are no longer supporting 100 per cent of the total load. When the pipe 12 is filled with water for hydrostatic testing after backfilling the support benches fail allowing the pipe to drop until padding material 24 beneath the pipe is fully compacted. After such failure the compacted material beneath the pipe is supporting 100% of the load. After such failure and compaction the pipe will be some distance h above the bottom of the trench. If the height had been 9″ after backfilling as illustrated in FIG. 7, then h would be less than 9″. This condition is illustrated in FIG. 8 where h is some distance smaller than the distance of the pipe above the trench floor prior to hydrostatic testing. In another embodiment the support bench is made of a material that will shatter or break into may pieces when subjected to a predetermined load. Such shattering could occur when the pipe is filled with water or when backfill is placed on top of the pipe. This embodiment would then be in multiple pieces 20 a as shown in FIG. 9 .
As the pipe drops lower, padding material 24 is compacted to a greater extent. In this condition, the padding material will be providing an increasing percentage of support while the support benches will be providing a decreasing percentage of support. It is entirely probable that, under the methods described here, the padding material will become fully compacted before the support bench would actually fail. The support bench as shown in FIG. 8 has been deformed and still is providing a share of the total support. Because the padding material is now fully compacted, the pipe can not drop any lower. Therefore, no further loading can be seen by the support bench, and the pipe is supported over 100% of its length.
Both of the preferred embodiments achieve the objective of providing greater support for a buried pipeline. In the embodiment illustrated by FIG. 9, the pipe is supported solely by the padding material beneath the pipe. This provides for the pipe to be supported along a much greater percentage of its length (approximately 90%) than that provided by the current art (approximately 10%). In the embodiment shown in FIG. 8, the pipe will be supported along 100% of its length. In both cases, however, the padding material beneath the pipe will have been fully compacted. Such full compaction does not occur when pipelines are installed using known support benches.
Another benefit which will be realized by this invention is that by designing and building support benches weaker than those required by the current art, material costs will be reduced as well. It is not unrealistic that this expense could be reduced by of 50 to 75%.
The examples given herein are meant for illustration purposes only and are not meant to limit the scope of the invention, which is properly delimited by the claims which follow.
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A method for supporting an underground pipeline in an excavated trench. The method involves supporting the pipeline on specially-designed support benches at spaced intervals. The benches are designed to fail when exposed to a predetermined load, which load will be placed on the benches at some point during the backfilling of the trench or when the pipeline undergoes hydrostatic testing. When the benches fail, the fill under the pipeline is compacted and thereby supports the pipeline in lieu of the support benches.
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FIELD OF THE INVENTION
[0001] The present invention relates to a process for preparing radiolabelled compounds. More specifically, the present invention relates to a process for preparing radiolabelled compounds, which involves incorporation of radioactive carbonyl groups into precursors, which are then used to make the radiolabelled compounds. These radiolabelled compounds have a number of uses including in vivo imaging techniques such as positron emission tomography.
BACKGROUND OF THE INVENTION
[0002] Positron emission tomography (PET) is a non-invasive imaging technique that offers high spatial and temporal resolution and allows quantification of tracer concentrations in tissues. The technique involves the use of radiotracers labelled with positron emitting radionuclides, which permit measurement of parameters regarding the physiology or biochemistry of a variety of living tissues.
[0003] Compounds can be labelled with positron or gamma emitting radionuclides. The most commonly used positron emitting (PET) radionuclides are 11 C, 18 F, 15 O and 13 N, which are accelerator produced, and have half lives of 20.4, 109.8, 2 and 10 minutes respectively. Due to their short half-lives 11 C, 15 O and 13 N labelled radiopharmaceuticals have to be use at the site of production and require the development of specific synthetic procedures.
[0004] 11 C (T 1/2 =20.4 min) is an important neutron-deficient radionuclide for PET because it can substitute for non-radioactive carbon in any organic molecule without altering their biological and physiochemical properties. An important part of the elaboration of new procedures to incorporate PET radionuclides into molecules is the development and handling of new 11 C labelled precursors.
[0005] 11 C can be produced in the absence of the naturally occurring stable isotopes 12 C and 13 C, and with high yields on a small proton accelerator using the 14 N(p,α) 11 C reaction in a target gas containing nitrogen (Christman, et al., 1975; Clark, et al., 1975 and Welch et al., 1968). In the presence of oxygen trace (e.g. 0.1% oxygen), the radiochemical species formed is [ 11 C]carbon dioxide which is suitable for use directly as in the 11 C-carboxylation of Grignard reagents (organomagnesium halides). [ 11 C]carbon dioxide can also be converted into a variety of secondary radiolabelled chemical entities such as high specific activity [ 11 C]methyl iodide.
[0006] An important consideration for radiolabelling with carbon-11 is the maximization of specific activity of the radiolabelled compound. Isotopic dilution of [ 11 C]carbon dioxide with atmospheric carbon dioxide (3.4×10 4 ppm) substantially reduces its specific activity and therefore limits the application of the resultant radiolabelled compound as a PET probe.
[0007] As an alternative method to using [ 11 C]carbon dioxide for radiolabelling compounds, [ 11 C]carbon monoxide may be used instead, as it is less prone to isotopic dilution with atmospheric carbon monoxide (0.1 ppm). Methods for the production of [ 11 C]carbon monoxide by reducing [ 11 C]carbon dioxide using reducing metals at high temperatures are well known (Gmelins 1972; Clark, et al., 1975; Zeisler, et al., 1997). Zinc and molybdenum are the most widely used reducing agent for the [ 11 C]carbon dioxide/carbon monoxide conversion.
[0008] However, it is difficult to trap 11 CO in the small volume of organic solvent in which most of the precursors for the production of radiolabelled compounds are soluble. Small volumes of solvent are required because this allows easy isolation of the radiolabelled product by means of preparative HPLC and increases the concentration of the starting materials in the reaction mixture, thereby forcing the reaction in the desired direction.
[0009] In 1978 Roeda, et al., described a method for the production of [ 11 C]phosgene from [ 11 C]carbon monoxide however, its practical use in the production of radiopharmaceuticals has been very limited due low yields and the lack of suitable equipment and methods to efficiently trap and react carbon monoxide.
[0010] Existing methods for the trapping of [ 11 C]carbon monoxide for the production of radiolabelled compounds rely on the use of high pressure or recirculation of [ 11 C]carbon monoxide to maintain adequately high levels of [ 11 C]carbon monoxide in solution (Kihlberg, et al., 1999; Hostetler, et al., 2002). This requires the use of dedicated automated robotic systems for the handling of [ 11 C]carbon monoxide and specialised equipment.
[0011] Borane carbonyl (H 3 BCO) is the immediate precursor to boranocarbonates, such as the potassium salt K 2 [H 3 BCO 2 ] which were reported to release CO in water at elevated temperatures in 1967 (Malone et al., 1967; Malone et al., 1967a). Although yields of the solid, air stable K 2 [H 3 BCO 2 ], produced from the known methods of B 2 H 6 +CO are good, it is not convenient to work under pressurised conditions with H 3 B.CO, as it is a pyrophoric gas (Carter, et al., 1965; Mayer, 1971). Alberto et al., (2001) found that by preparing H 3 B.CO from commercially available H 3 B.THF and reacting it in situ with an alcoholic solution of potassium hydroxide, K 2 [H 3 CO 2 ] could be produced at ambient pressures. This result was achieved by controlling the equilibrium of the two-way reaction between H 3 BCO and H 3 B.THF by selectively condensing the THF out of the reaction. The resultant K 2 [H 3 CO 2 ] was then used as an in situ source of CO in aqueous solution and as a reducing agent.
[0012] It has now been found that radiolabelled H 3 B.CO can be used to release radiolabelled carbon monoxide in organic solvents, aqueous solvents and mixtures of organic and aqueous solvents in order to prepare radiolabelled compounds without the need for high pressure autoclaves or recirculation units.
BRIEF SUMMARY OF THE INVENTION
[0013] Accordingly, in a first aspect the invention provides a process for the preparation of radiolabelled H 3 B.CO comprising contacting H 3 B in a suitable solvent with carbon monoxide and a suitable base, characterised in that the carbon monoxide is radiolabelled.
[0014] Radiolabelled H 3 B.CO may be prepared by the reaction of borane (H 3 B) in a suitable solvent with radiolabelled carbon monoxide. Suitable solvents for this reaction are those which solubilize H 3 B and allow it to co-ordinate with free electron pairs of the oxygen, for example tetrahydrofuran (THF) and ethers such as diethyl ether and dioxane. THF is preferred as a solvent due to its physical characteristics of a high boiling point, a lower affinity towards water and its comparable low price.
[0015] Hydrides of other elements, such as aluminium gallium, indium and thallium hydride would also be expected to co-ordinate with radiolabelled carbon monoxide. However, the instability of aluminium hydride in solvents suitable for this reaction means that if an aluminium compound were to be used it would preferably be compounds such as AlCl 3 in THF or aluminium tri organyls.
[0016] Free solvent may be removed from the reaction by condensation or other suitable means such as a solid support. This achieves the advantage of shifting the equilibrium of the reaction towards increased production of radiolabelled H 3 B.CO.
[0017] The carbon monoxide used in the reaction may be labelled by any conventional method with any of the following isotopes 11 C, 13 C, 14 C, 15 O or 18 O. Preferably 11 C is used.
[0018] Suitable solvents for use in the process of the invention include ethers such as diethyl ether and dioxane, and tetrahydrofuran. Preferably tetrahydrofuran is used. Suitable mixtures of solvents may also be used.
[0019] In a second aspect the invention provides the use of radiolabelled H 3 B.CO prepared according to the first aspect of the invention, as a donor of radiolabelled carbon monoxide in the manufacture by carbonylation of radiolabelled compounds.
[0020] In practice the second aspect of the invention may be carried out by using the radiolabelled H 3 B.CO prepared according to the first aspect of the invention in a coupling reaction as set out in Scheme 1 below, in which coupling reactions are typically carried out with a halide or a triflate (trifluoromethanesulfonate) with a nucleophile (alcohol, amine, thiol) or a organostannane, a base and a catalyst such as a palladium(0) catalyst to obtain esters, amides, ketones, aldehydes, carboxylic thioesters or by reacting a nitro component or an azido derivative to form isocyanate derivatives or condensing two nucleophiles in presence of selenium to synthesized carbamates, thiocarbamates, carbonates and ureas.
[0021] Suitable bases for use in the process of the invention include triethylamine (TEA), N-Methyldibutylamine (MDBA), M-Methyl-2,2,6,6-tetramethylpiperidine (N-MTMP) and N,N-di-isopropyl-ethylamine (DIPEA). Suitable mixtures of bases may also be used.
[0022] The starting materials and reagents for use in the first and second aspects of the invention are available commercially or can be synthesised by well-known and conventional methods. The reaction conditions used in the formation of non-radiolabelled H 3 B.CO can be sourced from Alberto et al., (2001), other reaction conditions such as the radiolabelling of CO and carbonylation reactions are well known.
[0023] [ 11 C]CO, prepared by reduction of [ 11 C]CO 2 with a reducing metal (commonly zinc or molybdenum), is trapped using conventional methods such as molecular sieves in liquid nitrogen or silica and is then carried into a solution of BH 3 .THF using an inert gas carrier. The [ 11 C]borane carbonyl ([ 11 C] H 3 B.CO) complex thus formed is then carried through to a reaction chamber in which it is reacted with suitable components to construct the required compound using conventional coupling methods. Conventional coupling reaction often take place at elevated temperatures and the reaction chamber may be made of materials suitable for use in a microwave (such as glass).
[0024] In order to promote the formation of the [ 11 C]borane carbonyl THF is removed from the reaction, typically by condensation. Coupling reactions are typically carried out reacting [ 11 C]borane carbonyl with the appropriate starting materials and reagents as depicted in scheme 1.
[0025] Suitable compounds for radiolabelling by this method are those which contain a carbonyl group (some examples are shown in Scheme 2).
[0026] Amides and imides can also contain lactams and carboxylic esters can also contain lactones.
[0027] In a third aspect the invention provides radiolabelled H 3 B.CO prepared in accordance with the first aspect of the invention.
[0028] In fourth aspect the invention provides radiolabelled compounds prepared by carbonylation in accordance with the second aspect of the invention.
[0029] Edidepride (N-((S)-1-Ethyl-pyrrolidin-2-ylmethyl)-3-iodo-5-methoxy-benzamide), FLB (5-bromo-N-((S)-1-ethyl-pyrrolidin-2-ylmethyl)-2,3-dimethoxy-benzamide) and raclopride (3,5-dichloro-N-((S)-1-ethyl-pyrrolidin-2-ylmethyl)-2-hydroxy-6-methoxy-benzamide), which are all dopamine D2 ligands and PK11195 (1-(2-Chloro-phenyl)-isoquinoline-3-carboxylic acid), which is a benzodiazepine receptor ligand are commonly used PET ligands that contain carbonyl groups that can be labelled with [ 11 C]CO.
[0030] In a fifth aspect the invention provides use of the radiolabelled compounds according to the fourth aspect of the invention in imaging techniques such as positron emission tomography, modified single photon emission tomography and autoradiography (classical and phosphor imaging plates).
[0031] In a sixth aspect the invention provides a composition comprising a radiolabelled compound in accordance with the fourth aspect of the invention and a pharmaceutically acceptable carrier or carriers, suitable for use in the above mentioned imaging techniques.
DETAILED DESCRIPTION OF THE INVENTION
[0032] The invention is further described through the following examples:
EXAMPLES
[0000] Abbreviation List:
[0000]
THF: Tetrahydrofuran
TEA: Triethylamine
DBU: 1,8-Diazabicyclo[5.4.0]undec-7-ene
TMP: Tetramethylpiperidine
DMF: Dimethylformamide
DIPEA: N,N-di-isopropyl-ethylamine
MDBA: N-Methyldibutylamine
N-MTMP: M-Methyl-2,2,6,6-tetramethylpiperidine
Synthesis of [ 11 C]N-benzyl-benzamide (I)
[0041]
Example 1
[0000] Preparation of the Reaction Vial
[0042] Palladium(II) diacetate (0.5 mg, 0.0022 mmol) and triphenylphosphine (2.9 mg, 0.011 mmol) were dissolved in 700 μL THF (degassed by bubbling N 2 through it for few minutes). Then, iodobenzene (1.5 mg, 0.00735 mmol) and benzylamine (1.2 mg, 0.011 mmol) dissolved in 300 μL THF (degassed by bubbling N 2 through it for few minutes) were added to the solution of palladium complex. TEA (1.6 μL, 0.0088 mmol) was added, and the reaction vial was placed in the reaction-setup in a bath at −78° C.
[0000] Synthesis
[0043] [ 11 C]Carbon dioxide was produced by the 14 N(p,α) 11 C nuclear reaction using a nitrogen gas target (containing 1% oxygen) pressurised to 150 psi and bombarded with 16 MeV protons using the General Electric Medical Systems PETtrace 200 cyclotron. Typically, the irradiation time was 30 minutes using-a 40 μA beam current. After irradiation, [ 11 C]carbon dioxide was trapped and concentrated on 4 Å molecular sieves. The trapped [ 11 C]CO 2 was released from molecular sieves in a stream of nitrogen (30 mL/min) by heating them to 350° C. [ 11 C]CO 2 was reduced on-line to [ 11 C]carbon monoxide after passing through a quartz tube filled with zinc granular heated to 400° C. The produced [ 11 C]carbon monoxide was transferred in our system set-up at 30 mL/min, where it was condensed on 4 Å molecular sieves at −196° C. After 6 min delivery and trapping of the [ 11 C]CO, the radioactive gas was then released at room temperature in a flow of nitrogen (6 mL/min) to bubble through a BH 3 .THF solution (1.5 mL of a 1.0 M solution) in order to make the [ 11 C]BH 3 .CO complex. This complex was carried with the flow of nitrogen through an empty vial cooled at −60° C. to remove the THF, and finally through the reaction vial containing the reactants (cf. preparation of the reaction vial above) cooled at −78° C. The trapping process took approximately 6 min (when the radioactivity level measured in the reaction vial has reached a maximum). The delivery tubings were then removed and the reaction vial heated in an oven at 110° C. for 10 min. The crude product was filtered through a 0.45 μm filter and analysed using analytical radio HPLC.
[0044] Analytical HPLC was performed using a Dionex system (SUMMIT HPLC system), equipped with a Dionex HPLC pump (Model P 680A LPG) with a 200 μl injection loop connected in series with a Phenomenex Sphereclone 5u ODS(2) column (250×4.60 mm, 5 μm), a variable Dionex UV/VIS detector (Type UVD 170U/340U) in series with a sodium iodide radiodetector of in-house design.
[0045] The desired end-product was identified by co-injection with a non-radioactive reference. The given yields of the product are based on the final radioactivity trapped in the reaction vial at EOS (End Of Synthesis).
[0046] The analytical HPLC showed the formation of the desired radiolabelled [ 11 C]N-benzylbenzamide in Example 1 in approximately 1.7% yield.
Example 2
[0047] The synthesis of [ 11 C]N-benzyl-benzamide was carried out as described in Example 1 except that the palladium(II) diacetate (0.5 mg, 0.0022 mmol) and triphenylphosphine (2.9 mg, 0.011 mmol) were dissolved in 700 μL of a solution of THF:H 2 O, 4:1 (degassed by bubbling N 2 through it for few minutes), the iodobenzene (1.5 mg, 0.00735 mmol) and benzylamine (1.2 mg, 0.011 mmol) were dissolved in 300/L of a solution of THF:H 2 O, 4:1 (degassed by bubbling N 2 through it for few minutes). The reaction vial was placed in the reaction-setup in a bath at 0° C. and after the trapping of the [ 11 C]BH 3 .CO the reaction vial was heated at 120° C. for 8 min, filtered and analysed for radioactivity content. The analysis of the HPLC chromatograms showed the formation of the desired radiolabelled [ 11 C]N-benzylbenzamide in approximately 7% yield.
Example 3
[0048] The synthesis of [ 11 C]N-benzyl-benzamide was carried out as described in Example 1 except that the palladium(II) diacetate (0.5 mg, 0.0022 mmol) and triphenylphosphine (2.9 mg, 0.011 mmol) were dissolved in 700 μL of a solution of THF+2% H 2 O (degassed by bubbling N 2 through it for few minutes), the iodobenzene (1.5 mg, 0.00735 mmol) and benzylamine (1.2 mg, 0.011 mmol) were dissolved in 300 μL of a solution of THF+2% H 2 O (degassed by bubbling N 2 through it for few minutes) and after the trapping of the [ 11 C]BH 3 .CO, the reaction vial was heated at 120° C. for 8 min, filtered and analysed for radioactivity content. The analysis of the HPLC chromatograms showed the formation of the desired [ 11 C]N-benzylbenzamide in approximately 30% yield.
Example 4
[0049] The synthesis of [ 11 C]N-benzyl-benzamide was carried out as described in Example 1 except that the palladium(II) diacetate (0.5 mg, 0.0022 mmol) and triphenylphosphine (2.9 mg, 0.011 mmol) were dissolved in 700 μL of a solution of THF+1% H 2 O (degassed by bubbling N 2 through it for few minutes), the iodobenzene (1.5 mg, 0.00735 mmol) and benzylamine (1.2 mg, 0.011 mmol) were dissolved in 300 μL of a solution of THF+1% H 2 O (degassed by bubbling N 2 through It for few minutes) and after the trapping of the [ 11 C]BH 3 .CO the reaction vial was heated at 50° C. for 8 min, filtered and analysed for radioactivity content. The analysis of the HPLC chromatograms showed the formation of the desired [ 11 C]N-benzylbenzamide in approximately 17% yield.
Example 5
[0050] The synthesis of [ 11 C]N-benzyl-benzamide was carried out as described in Example 4 except that after the trapping of the [ 11 C]BH 3 .CO, the reaction vial was heated at 70° C. for 8 min, filtered and analysed for radioactivity content. The analysis of the HPLC chromatograms showed the formation of the desired [ 11 C]N-benzylbenzamide in approximately 47% yield.
Example 6
[0051] The synthesis of [ 11 C]N-benzyl-benzamide was carried out as described in Example 4 except that after the trapping of the [ 11 C]BH 3 .CO, the reaction vial was heated at 85° C. for 8 min, filtered and analysed for radioactivity content. The analysis of the HPLC chromatograms showed the formation of the desired [ 11 C]N-benzylbenzamide in approximately 47% yield.
Example 7
[0052] The synthesis of [ 11 C]N-benzyl-benzamide was carried out as described in Example 4 except that after the trapping of the [ 11 C]BH 3 .CO, the reaction vial was heated at 120° C. for 8 min, filtered and analysed for radioactivity content. The analysis of the HPLC chromatograms showed the formation of the desired [ 11 C]N-benzylbenzamide in approximately 47% yield.
Example 8
[0053] The synthesis of [ 11 C]N-benzyl-benzamide was carried out as described in Example 4 except that after the trapping of the [ 11 C]BH 3 .CO, the reaction vial was heated at 140° C. for 8 min, filtered and analysed for radioactivity content. The analysis of the HPLC chromatograms showed the formation of the desired [ 11 C]N-benzylbenzamide was approximately 28% yield.
Example 9
[0054] The synthesis of [ 11 C]N-benzyl-benzamide was carried out as described in Example 5 except that DBU (1.3 μL, 0.0016 mmol) was used instead of TEA. The analysis of the HPLC chromatograms showed traces of the formation of the desired [ 11 C]N-benzylbenzamide.
Example 10
[0055] The synthesis of [ 11 C]N-benzyl-benzamide was carried out as described in Example 5 except that 2,2,6,6-TMP (1.7 μL, 0.009 mmol) was used instead of TEA. The analysis of the HPLC chromatograms showed the formation of the desired [ 11 C]N-benzylbenzamide in approximately 8% yield.
Example 11
[0056] The synthesis of [ 11 C]N-benzyl-benzamide was carried out as described in Example 5 except that pyridine (0.7 μL, 0.0088 mmol) was used instead of triethylamine and the reaction vial was heated from 40 to 80° C. for 15 min, filtered and analysed for radioactivity content. The analysis of the HPLC chromatograms showed the formation of the desired [ 11 C]N-benzylbenzamide in approximately 28% yield.
Example 12
[0057] The synthesis of [ 11 C]N-benzyl-benzamide was carried out as described in Example 5 except that benzylamine (3.6 mg, 0.034 mmol) was used instead of TEA and the reaction vial was heated 90° C. for 8 min, filtered and analysed for radioactivity content. The analysis of the HPLC chromatograms showed the formation of the desired [ 11 C]N-benzylbenzamide in approximately 20% yield.
Example 13
[0058] The synthesis of [ 11 C]N-benzyl-benzamide was carried out as described in Example 4 except that the palladium(II) diacetate, triphenylphosphine, iodobenzene and benzylamine benzylamine were dissolved in DMF, and after the addition of TEA the reaction vial was placed in the reaction-setup in a bath at −50° C. After the trapping of the [ 11 C]BH 3 .CO the reaction vial was heated at 90° C. for 8 min, filtered and analysed for radioactivity content. The analysis of the HPLC chromatograms showed the formation of the desired [ 11 C]N-benzylbenzamide in approximately 23% yield.
Example 14
[0059] The synthesis of [ 11 C]N-benzyl-benzamide was carried out as described In Example 4 except that the palladium(II) diacetate, triphenylphosphine, iodobenzene and benzylamine benzylamine were dissolved in 1,2-dichloroethane, and after the addition of TEA the reaction vial was placed in the reaction-setup in a bath at −20° C. After the trapping of the [ 11 C]BH 3 .CO the reaction vial was heated at 110° C. for 8 min, filtered and analysed for radioactivity content. The analysis of the HPLC chromatograms showed the formation of the desired [ 11 C]N-benzylbenzamide in approximately 12% yield.
Example 15
[0000] Preparation of the Reaction Vial
[0060] Preparation of the reaction vial was carried out as described in Example 1 except that the palladium (II) diacetate (0.5 mg, 0.0022 mmol) and triphenylphosphine (2.9 mg, 0.11 mmol) were dissolved in 700 μL THF with 1% H 2 O and the iodobenzene (1.5 mg, 0.00735 mmol) and benzylamine (1.2 mg, 0.011 mmol) were dissolved in 300 μL degassed THF with 1% H 2 O.
[0000] Synthesis
[0061] Synthesis of [ 11 C]N-benzyl-benzamide was carried out as described in Example 1 except that the produced [ 11 C]CO was condensed onto a trap at −196° C. made from a 12-inch coil of 1/16″ stainless steel tubing, 0.040″ i.d., packed with carbonex 1000, 45/60 mesh (Supelco). After 6 min delivery and trapping of the [ 11 C]CO, the radioactive gas was then released at room temperature and carried out through an empty vial in a flow of nitrogen (6 mL/min) into a reactor loaded with the BH 3 .THF solution (1.5 mL of a 1.0 M solution in THF) in order to form the [ 11 C]BH 3 .CO complex. The complex was then carried with the flow of nitrogen through an empty vial cooled at −78° C., and finally through the reaction vial containing the reactants cooled at −78° C. After 6 min of delivery of the [ 11 C]BH 3 .CO complex the tubings were removed and the reaction vial heated in an oven at a temperature o 95° C. for 10 min. The crude product was filtered through a 0.45 μm filter and analysed for radioactivity Content The analysis of the HPLC chromatograms showed the formation of the desired [ 11 C]N-benzylbenzamide in approximately 47% yield.
Example 16
[0062] The synthesis of [ 11 C]N-benzyl-benzamide was carried out as described in Example 15 except that the TEA was replaced with DIPEA (1.53 μL, 0.0088 mmol) and the reaction vial containing the [ 11 C]BH 3 .CO complex was heated in an oven at 90° C. for 10 min, filtered and analysed for radioactivity content The analysis of the HPLC chromatograms showed the formation of the desired [ 11 C]N-benzylbenzamide in approximately 91% yield
Synthesis of [ 11 C]phthalide
[0063]
Example 17
[0064] Tetrakis(triphenylphosphine)palladium(0) (1.1 mg, 0.95 μmol) was dissolved in 500 μL of a solution of THF+1% H 2 O (degassed by bubbling N 2 through it for few minutes). Then, a mixture of 2-bromobenzyl alcohol (1.1 mg, 0.006 mmol) and K 2 CO 3 (5 mg, 0.036 mmol) were dissolved in 300 μL of THF+1% H 2 O (degassed by bubbling N 2 through it for few minutes) and added to the solution of the palladium complex. The reaction vial was placed in the reaction-setup in a bath at −78° C. After the trapping of the [ 11 C]BH 3 .CO as described in Example 1, the reaction was heated at 100° C. for 4 min, filtered and analysed for radioactivity content The analysis of the HPLC chromatograms showed the formation of the desired [ 11 C]phthalide in traces.
Example 18
[0065] Palladium(II) diacetate (0.8 mg, 0.0035 mmol) and triphenylphosphine (5 mg, 0.020 mmol) were dissolved in 700 μL of a solution of THF+1% H 2 O (degassed by bubbling N 2 through it for few minutes). Then, a mixture of 2-bromobenzyl alcohol (2.2 mg, 0.012 mmol) and K 2 CO 3 (5 mg, 0.036 mmol) were dissolved in 300 μL of THF+1% H 2 O (degassed by bubbling N 2 through it for few minutes) and added to the solution of the palladium complex. The reaction vial was placed in the reaction-setup in a bath at −78° C. After the trapping of the [ 11 C]BH 3 .CO as described in Example 1, the reaction was heated at 120° C. for 5 min, filtered and analysed for radioactivity content. The analysis of the HPLC chromatograms showed the formation of the desired [ 11 C]phthalide in traces.
Example 19
[0066] Palladium(II) diacetate (0.8 mg, 0.0035 mmol) and triphenylphosphine (5 mg, 0.020 mmol) were dissolved in 700 μL of a solution of THF (degassed by bubbling N 2 through it for few minutes). Then, a mixture of 2-bromobenzyl alcohol (2.2 mg, 0.012 mmol) and DBU (2.0 μL, 0.014 mmol) was dissolved in 300 μL of THF (degassed by bubbling N 2 through it for few minutes) and added to the solution of the palladium complex. The reaction vial was placed in the reaction-setup In a bath at −78° C. After the trapping of the [ 11 C]BH 3 .CO as described in Example 1, the reaction was heated at 110° C. for 5 min, filtered and analysed for radioactivity content. The analysis of the HPLC chromatograms showed the formation of the desired [ 11 C]phthalide in traces.
Example 20
[0067] Palladium(II) diacetate (0.8 mg, 0.0035 mmol) and triphenylphosphine (5 mg, 0.020 mmol) were dissolved in 700 μL of a solution of THF (degassed by bubbling N 2 through it for few minutes). Then, a solution of 2-bromobenzyl alcohol (2.2 mg, 0.012 mmol) in 300 μL of THF (degassed by bubbling N 2 through it for few minutes) was added to the solution of the palladium complex. The reaction vial was placed in the reaction-setup in a bath at −78° C. After the trapping of the [ 11 C]BH 3 .CO as described in Example 1, the reaction was heated at 120° C. for 5 min, filtered and analysed for radioactivity content. The analysis of the HPLC chromatograms showed the formation of the desired [ 11 C]phthalide in approximately 40% yield.
Example 21
[0068] Palladium(II) diacetate (0.5 mg, 0.0022 mmol) and triphenylphosphine (2.9 mg, 0.011 mmol) were dissolved in 700 μL of a solution of THF+1% H 2 O (degassed by bubbling N 2 through it for few minutes). Then, a mixture of 2-bromobenzyl alcohol (2.2 mg, 0.012 mmol) and TEA (1.9 μL, 0.014 mmol) were dissolved in 300 μL of THF+1% H 2 O (degassed by bubbling N 2 through it for few minutes) and added to the solution of the palladium complex. The reaction vial was placed in the reaction-setup in a bath at −78° C. After the trapping of the [ 11 C]BH 3 .CO as described in Example 1, the reaction was heated at 90° C. for 8 min, filtered and analysed for radioactivity content. The analysis of the HPLC chromatograms showed the formation of the desired [ 11 C]phthalide in approximately 26% yield.
Example 22
[0069] Palladium(II) diacetate (1.0 mg, 0.0044 mmol) and triphenylphosphine (6 mg, 0.022 mmol) were dissolved in 700 μL of a solution of THF+1% H 2 O (degassed by bubbling N 2 through it for few minutes). Then, a mixture of 2-bromobenzyl alcohol (2.2 mg, 0.012 mmol) and TEA (1.9 μL, 0.014 mmol) were dissolved in 300 μL of THF+1% H 2 O (degassed by bubbling N 2 through it for few minutes) and added to the solution of the palladium complex. The reaction vial was placed in the reaction-setup in a bath at −78° C. After the trapping of the [ 11 C]BH 3 .CO as described in Example 1, the reaction was heated at 90° C. for 8 min, filtered and analysed for radioactivity content. The analysis of the HPLC chromatograms showed the formation of the desired [ 11 C]phthalide in approximately 20% yield.
Example 23
[0070] Palladium(II) diacetate (0.5 mg, 0.0022 mmol) and triphenylphosphine (2.9 mg, 0.011 mmol) were dissolved in 700/L of a solution of THF with 1% H 2 O (degassed by bubbling N 2 through it for few minutes). Then, a mixture of 2-bromobenzyl alcohol (1.37 mg, 0.0073 mmol) and DIPEA (1.53 μL, 0.0088 mmol) were dissolved in 300 μL of THF with 1% H2O (degassed by bubbling N2 through it for few minutes) and added to the solution of the palladium complex. The reaction vial was placed in the reaction-setup in a bath at −78 C. The trapping of the [ 11 C]BH 3 .CO complex was carried out as described in Example 15 and the reaction was heated at 95° C. for 10 min, filtered and analysed for radioactivity content. The analysis of HPLC chromatograms showed the formation of the desired [ 11 C]phthalide in approximately 40% yield.
Example 24
[0071] The synthesis of [ 11 C]phthalide was carried out as described in Example 23 except that the reaction was heated at 95° C. for 8 min, filtered and analysed for radioactivity content. The analysis of the HPLC chromatograms showed the formation of the desired [ 11 C]phthalide in approximately 89% yield min
Synthesis of [ 11 C]N-Methylnicotinamide
[0072]
Example 25
[0073] Palladium(II) diacetate (0.5 mg, 0.0022 mmol) and triphenylphosphine (2.9 mg, 0.011 mmol) were dissolved in 400 μL of a solution of THF with 1% H 2 O (degassed by bubbling N 2 through it for 5 minutes). Then, a mixture of 3-iodopyridine (1.5 mg, 0.0073 mmol) and DIPEA (1.53 μL, 0.0088 mmol) were dissolved in 600 μL of methylamine 2.0 M in solution in THF and then added to the solution of the palladium complex. The reaction vial was placed in the reaction-setup in a bath at −78° C. After the trapping of the [ 11 C]BH 3 .CO as described in Example 15, the reaction was heated at 140° C. for 8 min, filtered and analysed for radioactivity content. The analysis of the HPLC chromatograms showed the formation of the desired [ 11 C] N-Methylnicotinamide in approximately 95% yield
Synthesis of [ 11 C]6-[(3-cyclobutyl-2,3,4,5-tetrahydro-1H-3-benzazepin-7-yl)oxy]-N-methylnicotinamide (WO 2004/056369)
[0074]
Example 26
[0075] Palladium(II) diacetate (0.5 mg, 0.0022 mmol) and triphenylphosphine (2.9 mg, 0.011 mmol) were dissolved in 700 μL of a solution of THF with 1% H 2 O (degassed by bubbling N 2 through it for 5 minutes). Then, a mixture of 3-cyclobutyl-7-[(5-iodo-2-pyridinyl)oxy]-2,3,4,5-tetrahydro-1H-3-benzazepine (3.1 mg, 0.0073 mmol), DIPEA (1.53 μL, 0.0088 mmol) and methylamine 2.0 M (0.011 mmol, 5.48 μL solution in THF) were dissolved in 300 μL of THF with 1% H 2 O (degassed by bubbling N2 through it for 5 minutes) and added to the solution of the palladium complex. The reaction vial was placed in the reaction-setup in a bath at −78° C. After the trapping of the [ 11 C]BH 3 .CO as described in Example 15, the reaction was heated at 100° C. for 8 min filtered and analysed for radioactivity content. The analysis of the HPLC chromatograms showed the formation of the desired [ 11 C]6-[(3-cyclobutyl-2,3,4,5-tetrahydro-1H-3-benzazepin-7-yl)oxy]-N-methylnicotinamide in approximately 6.5% yield.
Example 27
[0076] Palladium(II) diacetate (0.5 mg, 0.0022 mmol) and triphenylphosphine (2.9 mg, 0.011 mmol) were dissolved in 400 μL of a solution of THF with 1% H 2 O (degassed by bubbling N 2 through it for few minutes). Then, a mixture of 3-cyclobutyl-7-[(5-iodo-2-pyridinyl)oxy]-2,3,4,5-tetrahydro-1H-3-benzazepine (1.6 mg, 0.00365 mmol), DIPEA (1.53 μL, 0.0088 mmol) and methylamine 2.0 M (0.011 mmol, 5.48 μL solution in THF) were dissolved in 300 μL of THF with 1% H2O (degassed by bubbling N2 through it for 5 minutes) and added to the solution of the palladium complex. The reaction vial was placed in the reaction-setup in a bath at −78° C. After the trapping of the [ 11 C]BH 3 .CO as described in Example 15, the reaction was heated at 140° C. for 8 min, filtered and analysed for radioactivity content. The analysis of the HPLC chromatograms showed the formation of the desired [ 11 C]6-[(3-cyclobutyl-2,3,4,5-tetrahydro-1H-3-benzazepin-7-yl)oxy]-N-methylnicotinamide in approximately 44.4% yield
Example 28
Synthesis of [ 11 C](4-(1-{4-[4-(3-Piperidin-1-yl-propoxy)-phenyl]-piperazin-1-yl}-methanoyl)-benzonitrile (WO 2004/035556)
[0077]
[0078] Palladium(II) diacetate (0.5 mg, 0.0022 mmol) and triphenylphosphine (2.9 mg, 0.011 mmol) were dissolved in 700 μL of a solution of THF with 1% H 2 O (degassed by bubbling N 2 through it for 5 minutes). Then, a mixture of 1-(4-{[3-(1-piperidinyl)propyl]oxy}phenyl)piperazine (2.05 mg, 0.0055 mmol), DIPEA (1.86 μL, 0.011 mmol) and 4-iodo-benzonitrile (0.0036 mmol, 0.85 mg) were dissolved in 300 μL of THF with 1% H2O (degassed by bubbling N2 through it for 5 minutes) and added to the solution of the palladium complex. The reaction vial was placed in the reaction-setup in a bath at −78° C. After the trapping of the [ 11 C]BH 3 .CO as described in Example 15, the reaction was heated at 140° C. for 7 min, filtered and analysed for radioactivity content. The analysis of the HPLC chromatograms showed the formation of the desired [[ 11 C](4-(1-{4-[4-(3-Piperidin-1-yl-propoxy)-phenyl]-piperazin-1-yl}-methanoyl)-benzonitrile in approximately 30% yield.
REFERENCES
[0000]
Alberto et al J. Am. Chem. Soc . (2001) 123, 3135-3136
Carter, J. C., Pary R. W., J. Am. Chem. Soc . (1965), 87, 2354-2358
Christman D. R., Finn R. D., Karistrom K. I. and Wolf A. P. (1975) Int. J. Appl. Radiat. Isot 26, 435-442
Clark, J. C. and Buckingham, P. D. (1975) Short - lived Radioactive Gases for Medical Use , p 231. Butterworths, London
Gmelins (1972) Handbuch der Anorganishen Chemie Vol. ‘Kohlenstoff’ C2, p. 203. Springer, Heidelberg
Hostetler, E. D. and Burns, H. D., Nucl. Med. Biol. (2002) 29, 845-848
Kihlberg, T., Bengt Langstrom T. B., J. Org. Chem . (1999) 64, 9201-9205
Malone L. J., Parry R. W., Inorg. Chem . (1967), 6, 817-822
Malone L. J., Inorg. Chem. (1967a), 6, 2260-2262
Mayer E., Monatsh. Chem. (1971), 102, 940-945
Roeda D., Crouzel C. and Van Zanten B (1978) Radiochem. Radioanal. Letts 33, 175-178
Welch M. J. and Ter-Pogossian M. M. (1968) Radiation Res. 36, 580-587)
Zeisler S. K., Nader M., Theobald A. and Oberdorfer F. (1997) Appl. Radiat. Isot . vol. 48, 1091-1095
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A process for preparing radiolabelled compounds by incorporation of radioactive carbonyl groups into precursors, which are then used to make the radiolabelled compounds. These radiolabelled compounds have a number of uses including in vivo imaging techniques such as positron emission tomography.
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CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application derives and claims priority from U.S. provisional application 61/369,365 filed 30 Jul. 2010, which application is incorporated herein by reference.
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
[0002] Not applicable.
BACKGROUND OF THE INVENTION
[0003] This invention relates in general to furnaces for melting metals and more particularly to a regenerative furnace having an easily detached media box.
[0004] Some furnaces that supply molten metal for casting and other procedures utilize regenerative furnaces to improve efficiency. The typical regenerative furnace includes an enclosure having a hearth at its bottom for containing a molten metal, which is often aluminum. At one end of the furnace the hearth has tap holes for withdrawing the molten metal. At the other end the furnace has two ports located above the hearth, and these ports are connected to burner assemblies that operate alternately for supplying hot gases to the interior of the furnace enclosure—indeed, hot enough to maintain the metal in the hearth in a molten condition.
[0005] Regenerative burners operate as a duel burner unit or as a pair, i.e., burner “A” and burner “B”. While burner “A” is firing, the media in its media box is releasing stored heat to the combustion air entering the furnace to elevate the temperature of the combustion air. The combustion air flows through the media in the media box to the burner head to mix with the gas or oil for combustion in the furnace. At the same time, burner “B” is being utilized as an exhaust system for the combustion hot waste gasses. An exhaust fan draws these hot waste gasses through the burner head of burner “B” and through the media in the burner “B” media box, where the hot waste gasses elevate the temperature of the media and the media bed lining. Once the exhaust gasses downstream of the media box reach a predetermined temperature, which usually takes about 40 to 60 seconds, a pair of air/exhaust duct cycling valves reverse their positions. This switches burner “A” from the burner firing into the furnace to the burner exhausting out of the furnace, and simultaneously switches burner “B” from the burner exhausting to the burner firing. These air/exhaust duct cycling valves are used for switching and reversing the flow of hot gases and combustion air through the media beds.
[0006] Each burner assembly has a burner and a media box containing a media that serves as a heat sink. The media usually takes the form of ceramic alumina spheres about one-inch in diameter. When the burner of one burner assembly operates, the hot exhaust gases that it produces discharge into the furnace enclosure above the molten metal and exhaust through the other burner assembly, passing through the media box of that other assembly. Here, the hot exhaust gasses elevate the temperature of the media as the media absorb heat from the hotter gases. After passing through the media, the hot waste gasses discharge into a lateral duct near the bottom of the media box. Then about 40 seconds later the burner shuts down and the burner of the assembly through which the hot gases formerly discharged ignites, the flow of hot gases reverses and combustion air flows through the furnace enclosure. The combustion air for that burner passes through the hot media in the media box for that burner assembly where the temperature of the combustion air is elevated as the media release their stored heat into the cooler gases. Hence, the burner operates more efficiently. Of course, the hot gases from the furnace enclosure now flow out of the idle burner assembly and elevate the temperature of the media in the media box of that assembly. The burners of the two burner assemblies alternate in supplying hot gases to the furnace enclosure, so that the molten metal within the hearth is continuously subjected to hot gases.
[0007] During this process, a dross develops over the surface of the molten metal in the hearth that contains various contaminants, such as salts and oxides of aluminum, which the hot exhaust gases pick up. As the gases flow through the media in the media boxes of the two burner assemblies, they deposit some of those contaminants onto the media. These deposits will eventually clog the media. Hence, from time to time each media box is detached from the burner and the lateral duct to which it is connected and taken to a remote location where the media are cleaned and otherwise reconditioned. This is a time-consuming procedure that traditionally requires removing bolts from hot flanges where the burner and the lateral duct couple to the media box and then maneuvering the heavy media box away from the burner and duct without damaging either.
[0008] It is therefore desirable to provide a burner assembly in which the media box is adapted to rapidly disconnect from and reconnect to the burner and duct associated with high a temperature furnace. The burner assembly of the present invention overcomes the problems described above and provides significant benefits over existing configurations.
DESCRIPTION OF THE DRAWINGS
[0009] The illustrative embodiments of the present invention are shown in the following drawings which form a part of the specification:
[0010] FIG. 1 is a side elevation view, partially broken away, of a furnace constructed in accordance with and embodying the present invention;
[0011] FIG. 2 is an elevation view of the burner assembly for the furnace with the media box of that assembly withdrawn from the burner;
[0012] FIG. 3 is a plan view of the media box and carriage, with the media box disengaged from the furnace;
[0013] FIG. 4 is an end elevation view of the burner assembly engaged with a furnace;
[0014] FIG. 5 is a side elevation view of the burner assembly showing the media box engaged by a lift truck, but not yet displaced;
[0015] FIG. 6 is a side view similar to FIG. 5 , but showing the truck tilting the media box in the carriage to separate the media box from the burner;
[0016] FIG. 7 is a side view similar to FIG. 6 , but showing truck withdrawing the media box and carriage from the burner;
[0017] FIG. 8 is a side elevation view showing the media box at a media washing station;
[0018] FIG. 9 is an elevation view similar to FIG. 8 , but showing the media box tilted to discharge the media into a washing basket at the media washing station;
[0019] FIG. 10 is an end elevation view showing the media box at the washing station; and
[0020] FIG. 11 is a plan view of a furnace constructed in accordance with and embodying the present invention having two interchangeable burner assemblies;
[0021] Corresponding reference characters indicate corresponding parts throughout the several views of the drawings.
DETAILED DESCRIPTION OF INVENTION
[0022] Referring now to the drawings, a regenerative furnace A ( FIGS. 1 , 5 - 7 ) for melting metal and maintaining the metal in a molten state includes a furnace enclosure 2 and a hearth 4 within the enclosure 2 for containing the molten metal. At its one end the enclosure 2 has two ports 6 ( FIG. 11 ) at which two separate yet interchangeable burner assemblies 10 are connected to the enclosure 2 . The burner assemblies 10 operate alternately such that while one or the other discharges hot gases, the product of combustion into the furnace enclosure 2 , the other burner assembly 10 receives the hot exhaust gasses from the furnace enclosure 2 and directs it into a laterally directed duct 12 ( FIG. 4 ). The duct 12 acts to supply gases for combustions when not acting to exhaust gasses from the furnace enclosure 2 .
[0023] Each burner assembly 10 includes a burner 20 that is mounted on the furnace enclosure 2 , a media box 22 that is located between the burner 20 and the lateral duct 12 , and a carriage 24 that supports the media box 22 such, the burner assembly 10 being configured such that it can with relative ease be withdrawn away from the lateral duct 12 and burner 20 . To this end, the carriage 24 moves along rails 26 that extend past the lateral duct 12 and generally beneath the burner 20 .
[0024] The burner 20 ( FIG. 1 ) includes a burner head 30 that is attached to the furnace enclosure 2 at one of the ports 6 of the enclosure 2 such that its interior opens into the interior of the enclosure 2 . The head 30 has several nozzles 32 that discharge one or more combustible gases into the head 30 where the gas or gases mix with combustion air and ignite to produce a flame that is directed through the burner head 30 and into the interior of the furnace enclosure 2 . That combustion air enters the head 30 through a burner throat 34 that extends generally downwardly from the head 30 . At its lower end, the throat 34 has a flange 36 that is disposed generally horizontally, but slightly askew such that the flange 36 is presented upwardly at a slight angle away from the enclosure with respect to the vertical.
[0025] The lateral duct 12 ( FIG. 4 ) also has a flange 40 , but its flange 40 is presented upwardly at an oblique angle with respect to the horizontal, preferably at 45°.
[0026] The carriage 24 ( FIG. 1 ) has a frame 50 fitted with wheels 52 that rest on and are capable of rolling along the rails 26 . The frame 50 supports side walls 54 that are spaced far enough apart to receive the media box 22 between them without binding. At their upper ends, the side walls 54 have cradles 56 that define an axis X that extends horizontally and transversely with respect to the rails 26 . The rails 26 enable the carriage 24 to move toward and away from the furnace enclosure 2 , but have stops 58 that establish a fixed position beyond which the carriage 24 cannot advance farther toward the furnace enclosure 2 .
[0027] The media box 22 includes ( FIGS. 1 , 3 & 4 ) spaced apart side walls 60 , and spaced apart end walls 61 and 62 , one of which end walls 61 is positioned at the front of the box 22 where it is presented toward the furnace enclosure 2 and the other of which end walls 62 is at the back of the box 22 and is presented away from the enclosure 2 . In addition, the box 22 has a bottom wall 64 and a top lid 66 . All of the walls 60 - 62 , 64 and the lid 66 are arranged to provide the box 22 with an orthogonal configuration. The spacing between the two side walls 60 is less than the spacing between the side walls 54 of the carriage 24 , so that the media box 22 will fit freely between the side walls 54 of the carriage 24 to be supported above the frame 50 of the carriage 24 . To this end, the box 22 has trunnions 68 that project laterally from its side walls 60 and into the cradles 56 on the side walls 54 of the carriage 24 , and when so disposed a space exists between the bottom wall 64 of the box 22 and the frame 50 of the carriage 24 . This enables the media box 22 to pivot about the axis X on the carriage 24 . Moreover, the trunnions 68 are offset horizontally from the horizontal center of gravity for the media box 22 such that the horizontal center of gravity is located between the trunnions 68 and the back end wall 62 . As a consequence, the media box 22 seeks to rotate about the axis X such that the front end wall 61 will seek to move upward, the rear end wall 62 will seek to move downward, and the media box 22 will seek to assume a tilted position on the carriage 24 .
[0028] One of the side walls 60 near the bottom wall 64 has a port 70 that opens laterally and terminates at a flange 72 that lies oblique to the horizontal at an angle corresponding to the angle of the flange 40 on the lateral duct 12 . The flange 72 carries a high temperature seal 74 that interfaces with the flange 40 . Near the lid 66 , the side walls 60 have fork lift rails 78 , which can receive the tines of a fork on a lift truck.
[0029] The lid 66 of the media box 22 has a vertical port 80 that opens into the interior of the box 22 near the front end wall 61 . The port 80 terminates at a pocket 82 that is large enough to receive the flange 36 on the burner throat 34 . The pocket 82 contains high temperature seal 84 at its base. The pocket 82 does indeed receive the flange 36 on the burner throat 34 , but only when the forward most wheels 52 of the carriage are against the stop 58 on the rails 26 . Moreover, when the box 22 is so disposed, its lateral port 70 aligns with the lateral duct 12 , and the flange 40 on the duct 12 seats against the seal 74 of the flange 72 on the port 70 . In addition to the vertical port 80 , the lid 66 has a re-sealable top latch door 86 for gaining access to the interior of the box 22 . Moreover, the lid 66 itself is removable from the media box 22 .
[0030] The back end wall 62 also has a removable latch door 88 that when removed exposes the interior of the box 22 . Further, the end wall 62 also has a bracket 90 at which an upwardly directed force may be applied to the box 22 to tilt it on its trunnions 68 about the axis X.
[0031] Normally, the box 22 , owing to the displacement of its center of gravity rearward from the trunnions 68 , seeks to tilt downwardly at its bracket 90 , but when the media box 22 is positioned such that the pocket 80 is receiving the burner throat 34 , the rotation of the media box 22 about its trunnions 68 is restrained by the burner 20 , since the flange 36 of its burner throat 34 is in the pocket 82 of the vertical port 80 . Indeed, the off-center force from the forward location of the trunnions 78 acts to seat the high temperature seal 84 that is in the pocket 82 snugly against flange 36 on the burner throat 34 . The off-center force also seats the seal 74 on the oblique flange 72 of the lateral port 70 snugly against the oblique flange 40 or the lateral duct 12 . Of course, if utilized, the pin 104 positioned in the bores 100 and 102 , must first be removed to allow the media box 22 to freely rotate about its axis X in the carriage 24 .
[0032] Referring to FIG. 1 , a through bore 100 is positioned in one of the side walls 54 of the carriage 24 such that it aligns with a bore 102 in the corresponding side wall 60 of the media box 22 when the media box 22 is rotated about its axis X to disengage the media box 22 from the furnace A. A pin 104 , configured to fit within the bores 100 and 102 , can then be placed through the through bore 100 and into the bore 102 to prevent the media box 22 from further rotating about its axis X until the pin 104 is removed. Pressure from the tendency for the media box 22 to rotate about its axis X will hold the pin 104 in place in the bores 100 and 102 . In fact, it will be necessary to apply rotational counter pressure to the media box 22 to allow the pin 104 to be readily withdrawn from the bores 100 and 102 .
[0033] The media box 22 ( FIG. 1 ) contains a grid-like rack 94 that extends horizontally from end wall 61 to end wall 62 and likewise horizontally from one side wall 60 to the other. The rack 94 lies immediately below the latch door 88 in the back end wall 62 and above the port 70 in the one side wall 60 . The rack 94 supports media 96 consisting of discrete elements, which may be spherical or some other configuration and are formed from a substance capable of withstanding the temperature of exhaust gases leaving the furnace enclosure 2 and passing into the media box 22 at the burner throat 34 . Such media 96 may comprise, for example, ceramic alumina spheres of about one inch diameter. These exhaust gases pass through the media 96 and heat the media 96 , thus elevating the temperature of the media 96 to enable the media 96 to serve as a heat sink. When the furnace cycle reverses, combustion air enters the media box 22 at the lateral port 70 and flows through the media 96 to extract heat from them. As a consequence, the combustion air undergoes an increase in temperature, so that it enters the burner 20 at an elevated temperature. This renders the combustion in the burner 20 more efficient.
[0034] However, in flowing through the furnace enclosure 2 , the hot exhaust gases pick up contaminants such as salts and metal oxides, including aluminum oxides and salts, from the dross that floats over the molten metal in the hearth. When the hot exhaust gases flow from the furnace enclosure 2 in the opposite direction into the media box 22 while the burner 20 is shut down, the contaminants picked up by the hot exhaust gases deposit on the media 96 . As a consequence, from time to time the media box 22 needs to be detached from the burner assembly 10 and the lateral duct 12 so that the media 96 within it can be cleaned.
[0035] When using the present invention, this detachment is a quick and simple procedure. To this end, a lift truck B ( FIGS. 5-7 ) having a fork 100 that can be maneuvered upwardly and downwardly is fitted at the very front of its fork 100 with an attachment tool 102 that is capable of engaging the bracket 90 at the back end of the media box 22 from beneath such that the truck B can exert an upwardly directed force on the bracket 90 as well as a horizontal force along the direction of the rails 26 . Indeed, the truck B is maneuvered to bring the attachment tool 102 beneath the bracket 90 on the media box 22 ( FIG. 5 ). Thereupon, the fork 100 is elevated while the truck B itself remains stationary ( FIG. 6 ). The upwardly directed force tilts the media box 22 about the axis X of the trunnions 68 , causing the front end of the media box 22 to dip downwardly and its back end to rise. Thereupon the pocket 82 at the front of the box 22 withdraws from the burner throat 34 . Simultaneously, the oblique flange 72 on the port 70 lifts off the oblique flange 40 in the lateral duct 12 ( FIG. 7 ). The operator of the lift truck B then reverses the truck B to pull the media box 22 away from the burner assembly 10 and lateral duct 12 .
[0036] The box 22 moves on the carriage 24 which follows the rails 26 away from burner throat 34 until the box 22 is positioned such that it will not contact the burner throat 34 when the box 22 is allowed to rotate within the carriage 24 to its point of rest with the bracket 90 pressed against the ground below the box 22 . The box 22 may then be raised and removed from the carriage 24 . The operator can then deliver the media box 22 to a location where the media 96 may be removed from it. This may, for example, involve removing the attachment tool 102 from the fork 100 of the lift truck B and inserting the tines of the fork 100 into the fork lift rails 78 of the media box 22 . Alternately, the lid 66 may be removed to gain access to the media 96 .
[0037] Once the media 96 are cleaned and replaced in the media box 22 , the truck operator maneuvers the truck B so that the box 22 is placed atop the carriage 24 with the trunnions 68 resting in the cradles 56 in the side walls 54 of the carriage 24 , where the carriage 24 has remained positioned atop the rails 26 . The operator of the truck B then places the attachment tool 102 on the fork 100 of the truck B and engages tool 102 with the bracket 90 on the back end of the media box 22 . An upwardly directed force applied to the bracket 90 tilts the box 22 on the carriage 24 , lowering the pocket 82 in its vertical port 80 and elevating the lateral port 70 on its one side wall 60 ( FIG. 7 ). The operator moves the truck, and thereby the carriage 24 , forwardly toward the furnace enclosure 2 until the forward wheels 52 of the carriage 24 abut against the stops 58 at the ends of the rails 26 ( FIG. 6 ). The operator then lowers the fork 100 and, by reason of the displacement of its center of gravity from the trunnions 68 , the media box 22 tilts back to a horizontal orientation in which it is restrained by the flange 36 on the burner throat 34 ( FIG. 5 ). The flange 36 seats in the pocket 82 of the vertical port 80 , effecting a barrier with the seal 84 in that pocket 82 . The seal 74 in the oblique flange 72 of the lateral port 70 likewise seats against the oblique flange 40 at the end of the lateral duct 12 ( FIG. 4 ).
[0038] The construction of the media box 22 and its placement at the end of the furnace enclosure 2 on the carriage 24 not only facilitates rapid removal of the media box 22 , but also the actual removal of contaminants from the media 96 . In this regard, once the media box 22 is separated from the burner throat 34 and the lateral duct 12 , and is withdrawn from those furnace components by the truck B, the truck operator engages the fork 100 of the truck B with the fork lift rails 78 along the side walls 60 of the media box and delivers the media box 22 to a media cleaning station C ( FIGS. 8-10 ). The station C includes a frame 110 that has side walls 112 that are spaced apart sufficiently to enable the media box 22 to freely fit between them. Moreover, the side walls 112 at their upper ends have cradles 114 that are capable of receiving the trunnions 68 on the media box 22 when the media box 22 is positioned between the side walls 112 . This arrangement resembles the carriage 24 , except that the side walls 112 are higher, and the frame 110 rests in a fixed position. The frame 110 supports a washing basket 116 that is offset from the side walls 112 , yet aligned with the space between them. The washing basket 120 has porous walls, preferably formed from a grid-like material having openings smaller than the individual elements of the media 96 .
[0039] To remove contaminants from the media 96 , the truck operator raises the media box 22 to a position in which its trunnions 68 are above the cradles 114 of the cleaning station C and the latch door 88 on the back end wall 62 is above the washing basket 120 . The operator then lowers the media box 22 until its trunnions 68 are received in the cradles 114 on the side walls 112 and the box 22 is supported by the side walls 112 ( FIG. 8 ). Owing to the displacement of the center of gravity for the media box 22 from the trunnions 68 , the media box 22 tilts downwardly toward the basket 120 once free of the fork 100 of the truck B ( FIG. 9 ). Thereupon, the latch door 88 in the back end wall 62 of the media box 22 is removed, and the media 96 are allowed to tumble out of the box 22 into the washing basket 120 . While in the washing basket 120 , the media 96 are subjected to a cleaning process, such as for example a stream of water, that removes the contaminants deposited on media 96 .
[0040] Once the contaminants are removed, the media 96 are returned to the media box 22 where the media 96 are supported on the porous rack 94 . Thereupon, the media box 22 is moved to the carriage 24 and the carriage 24 is maneuvered to bring the pocket 82 of the box 22 beneath and in pressed contact with the burner throat 34 , and to simultaneously align and interconnect the port 70 with the lateral duct 12 .
[0041] In lieu of the media 96 which takes the form of a multitude of discrete elements organized randomly on the rack 94 , the high temperature heat sink in the media box 22 may take other alternate forms, such as the form of a solid block that is porous. Indeed, the block may be oriented vertically so that the gases flow horizontally through it.
[0042] While we have described in the detailed description different configurations that may be encompassed within the disclosed embodiments of this invention, numerous other alternative configurations, that would now be apparent to one of ordinary skill in the art, may be designed and constructed within the bounds of my invention as set forth in the claims. Moreover, the above-described novel burner assembly 10 of the present invention can be arranged in a number of other and related varieties of configurations without expanding beyond the scope of my invention as set forth in the claims.
[0043] For example, the present invention is not limited to a single or even two sets of assemblies 10 , but may include multiple sets of interchangeable media boxes 22 and carriages 24 . Additionally, each of the components of the assembly 10 may be of varying sizes and shapes, so long as the configuration of each component, when combined in the assembly 10 , allows the assembly 10 to have the unique features and attributes as described in this disclosure. Further, the assembly 10 may be configured to allow the media box 22 to releasably attach to a single port or duct (such as at 34 and 12 ), or multiple such ports or ducts as may be desired or necessary for the proper operation of the furnace system.
[0044] Of course, the carriage 24 may be configured to be tilted and/or withdrawn from the furnace by a variety of other methods other than by a lift truck B. For example, the carriage 24 my incorporate a motor or other such self-contained locomotion apparatus. Alternatively, dissociated pistons, pulley systems, or other such devices may alternately be used to tilt and/or move the carriage 24 .
[0045] Further, depending on the configuration of the furnace and its burners and combustion gas ducts, the media box 22 may be configured to tilt or rotate forward, backward, or from side to side to engage with and disengage from such burners and ducts. In addition, it is contemplated that the operation of the assembly 10 could be automated, such as with a computer control system.
[0046] Additional variations or modifications to the configuration of the novel heater system media bed float system 10 of the present invention may occur to those skilled in the art upon reviewing the subject matter of this invention. Such variations, if within the spirit of this disclosure, are intended to be encompassed within the scope of this invention. The description of the embodiments as set forth herein, and as shown in the drawings, is provided for illustrative purposes only and, unless otherwise expressly set forth, is not intended to limit the scope of the claims, which set forth the metes and bounds of our invention.
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A burner assembly comprising a burner with a body and a burner throat extending downwardly from the burner body, a carriage located below the burner and provided with a cradle, a media box configured to pivotally mate with the cradle along a horizontal axis of the media box such that the media box is supported on the carriage at the axis and can rotate on the carriage about the axis, the media box having a port that connects with the burner throat but that separates from the burner throat when the media box is tilted about its axis, and media in the media box to serve as a heat sink, where the axis is horizontally offset from the media box's center of gravity, and the media box may be rotated about the horizontal axis to allow for ready engagement and disengagement between the media box and the burner.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to viscous fluid heaters having rotors that shear viscous fluid to generate heat, which is transferred to circulating coolant.
2. Description of the Related Art
Viscous fluid heaters, which are operated by drive force of automobile engines, have become widely used as auxiliary heat sources. Japanese Unexamined Patent Publication No. 2-246823 discloses a typical viscous fluid heater, which is incorporated into the heating system of an automobile.
The viscous fluid heater includes front and rear housings that define a heating chamber, A water jacket (heat exchange chamber) is defined outside the heating chamber. The front housing rotatably supports a drive shaft by means of a bearing. A rotor is fixed to one end of the drive shaft and is rotated integrally with the drive shaft in the heating chamber. Adjacent labyrinth grooves are formed in the front and rear surfaces of the rotor. Labyrinth grooves are also formed in the heating chamber walls opposing the front and rear surfaces of the rotor. Each labyrinth groove of the rotor surfaces is arranged between two labyrinth grooves of the opposing wall. Viscous fluid such as silicone oil fills the space between the heating chamber walls and the rotor surfaces.
The drive force of the engine rotates the drive shaft together with the rotor in the heating chamber. The rotation of the rotor shears the viscous fluid that fills the space between the heating chamber walls and the rotor surfaces to generate heat. Heat is transferred from the heated viscous fluid to the coolant circulating in the water jacket. The heated coolant is then sent to an exterior heater circuit to warm the passenger compartment.
In prior art viscous fluid heaters, most of the viscous fluid in the heating chamber ocuupies a slight gap provided between the rotor surfaces and the heating chamber walls. The rotating force produced by the engine is transmitted to the drive shaft of the viscous fluid heater. Thus, the rotating speed of the rotor is determined by the engine speed. When the angina speed is high, the shearing of the viscous fluid heats the fluid to a high temperature. High temperatures accelerate the deterioration of the viscous fluid. Deterioration of the viscous fluid decreases the viscosity of the fluid. If the viscosity of the fluid becomes low, the generated heat per rotation of the rotor decreases accordingly. Therefore, the heater may not produce the desired amount of heat.
SUMMARY OF THE INVENTION
Accordingly, it is an objective of the present invention to provide a viscous fluid heater that prolongs the life of the viscous fluid.
It is a further objective of the present invention to provide a viscous fluid heater having an improved heating efficiency.
To achieve the above objectives, the present invention provides a viscous fluid type heater. The heater includes a heating chamber containing viscous fluid. The heating chamber has a first wall. A rotor is located in the heating chamber. The rotor is rotated by a drive shaft to shear the viscous fluid and produce heat in the heating chamber. The rotor has a first surface facing the first wall. The first rotor surface and the first wall are spaced apart by a predetermined distance. Some of the viscous fluid occupies the space between the first rotor surface and the first wall and is sheared when the rotor is rotated. A heat exchange chamber is located close to the heating chamber. The heat exchange chamber communicates with a coolant circuit. Heat generated by the fluid shearing is transmitted from the heating chamber to the coolant in the heat exchange chamber to heat the coolant in the fluid circuit. A support shaft supports the rotor. The support shaft is eccentrically coupled to the drive shaft.
Other aspects and advantages of the invention will become apparent from the following description, taken in conjunction with the accompanying drawings, illustrating by way of example the principals of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
The features of the present invention that are believed to be novel are set forth with particularly in the appended claims. The invention, together with objects and advantages thereof, may best be understood by reference to the following description of the presently preferred embodiments together with the accompanying drawings in which:
FIG. 1 is a cross-sectional view showing a first embodiment of a viscous fluid heater according to the present invention;
FIG. 2 is a cross-sectional view taken along the line 2--2 in FIG. 1;
FIG. 3 is a cross-sectional view taken along the line. 3--3 in FIG. 1;
FIG. 4 is an explanatory diagram showing the movement of the rotor;
FIG. 5 is a partial cross-sectional view showing a second embodiment of a viscous fluid heater according to the present invention;
FIG. 6(a) is a partial cross-sectional view showing a third embodiment or a viscous fluid heater according to the present invention;
FIG. 6(b) is an enlarged view showing a portion of the viscous fluid heater of FIG. 6(a);
FIG. 7 is a partial cross-sectional view showing a water jacket employed in a further embodiment of a viscous fluid heater according to the present invention;
FIG. 8 is a partial cross-sectional view showing a water jacket employed in a further embodiment of a viscous fluid heater according to the present invention;
FIGS. 9(a), 9(b), and 9(c) are front views, each showing a pattern provided on the rotor to increase the shearing force of the rotor in a viscous fluid heater according to further embodiments of the present invention; and
FIGS. 10(a) and 10(b) are front views each showing a rotor employed in a viscous fluid heater according to further embodiments of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
A first embodiment of a viscous fluid heater according to the present invention, which Is incorporated in a heater of an automobile, will now be described with reference to FIGS. 1 to 3.
As shown in FIG. 1, a plurality of bolts 4 (three in this embodiment) fasten a front housing 1, a rear housing 2, and a rear plate 3 to one another. An O-ring 5 seals the gap between the front housing 1 and the rear housing 2, while a gasket 6 seals the gap between the rear housing 2 and the rear plate 3. The rear housing 2 is formed from a material having superior heat conductivity, such as aluminum or aluminum alloy. The rear plate 3 is formed from a material such as stainless steel, the heat conductivity of which is inferior to that of the rear housing 2.
A bore 1a is provided in the rear side of the front housing 1. A bore 2a, which is connected with the bore 1a, is provided in the front side of the rear housing 2. The bores 1a, 2a define a heating chamber 7. A socket 1b, which is communicated with the bore 1a, is provided in the front housing 1. The socket 1b and the heating chamber 7 are coaxial. A drive shaft 8 is received in the socket 1b and is rotatably supported by a bearing 9. The bearing 9 is an angular bearing and is provided with lip seals. The lip seals prevent the viscous fluid in the heating chamber 7 from leaking out of the heating chamber 7 through the space between the inner race and outer race of the bearing 9. One end of the bearing 9 abuts against the front housing 1 while the other end of the bearing 9 abuts against a stopper ring 10. Thus, the bearing 9 is hold at a predetermined position. A large diameter portion Sa is defined at the rear end of the drive shaft 8. The bearing 9 supports the large diameter portion 8a of the drive shaft 8.
An eccentric shaft 11 is fixed to the large diameter portion 8a of the drive shaft 8 extending into the heating chamber 7. The axis of the eccentric shaft 11 is eccentric to the drive shaft 8. A cylindrical rotor 12 is fitted to the eccentric shaft 11 so that the rotor 12 and the eccentric shaft 11 are coaxial. The rotor 12 is fixed so that it does not rotate relative to the eccentric shaft 11.
The rotor 12 includes a rear surface 12a, which faces the rear housing 2. The rotor 12 is arranged on the eccentric shaft 11 so that a first gap δ of 0.1 mm to 0.5 mm is provided between the rear surface 12a and the opposing wall of the rear housing 2. The range of the first gap δ has been experimentally based on efficiency. A variable second gap ε is provided between the peripheral surface of the rotor 12 and the peripheral wall of the heating chamber 7 in the radial direction of the heating chamber 7. The minimum distance of the second gap ε is uniform throughout the heating chamber 7 and is determined at a value that efficiently shears the viscous fluid included in the second gap ε.
A reservoir 13 and an annular water jacket 14 are defined in the rear housing 2 in front of the rear plate 3 at positions corresponding to the heating chamber 7. The water jacket 14 defines a heat exchange chamber that is adjacent to the heating chamber 7. The heating chamber 7 is communicated with the reservoir 13 through passages 2b, 2c, which extend through the rear housing 2. A certain amount of silicone oil F, which serves as the viscous fluid, is provided in the heating chamber 7 and the reservoir 13. The passage 2b connects the lower portion of the reservoir 13 with the heating chamber 7, while the passage 2c connects the upper portion of the reservoir 13 with the heating chamber 7. Silicone oil F is reserved in the reservoir 13, with the surface of the silicone oil F located below the passage 2c.
The rear housing 2 includes a partition 2d (FIG. 3) and two arcuate fins 2e. The partition 2d extends radially in the water jacket 14. Each fin 2e projects toward the gasket 6 and extends circumferentially about the reservoir 13 in the water jacket 14. The partition 2d is in contact with the gasket 6, while each fin 2e is spaced from the gasket 6.
As shown in FIG. 3, an inlet 15 and an outlet 16 are provided in the rear housing 2. Coolant flows through the inlet 14 into the water jacket 14 from a heater circuit (not shown) of an automobile. The coolant in the water jacket 14 returns to the heater circuit through the outlet 16. The partition 2d separates the inlet 15 from the outlet 16. Thus, the coolant that flown into the water jacket 14 through the inlet 15 is guided by the fins 2e and is circulated through the water jacket 14 in a clockwise direction, as viewed in FIG. 3. After circulating through the water jacket 14, the coolant flows out of the water jacket 14 though the outlet 16.
A cylindrical support 1c projects from the front housing 1. An electromagnetic clutch 17 is arranged in the vicinity of the front ends of the drive shaft 9 and tho cylindrical support 1c. The electromagnetic clutch 17 includes a pulley 19 and a disc-like clutch plate 21. The pulley 19 is rotatably supported on the support 1c by an angular bearing. A support ring 20 is fastened to the front end of the drive shaft 8. The clutch plate 21 is fitted on the support ring 20. Relative sliding in the axial direction is permitted between the clutch plate 21 and the support ring 20. A loaf spring 22 is arranged in front of the clutch plate 21 with its central portion fixed to the support ring 20. The peripheral portion of the leaf spring 22 (upper and lower portions, as viewed in FIG. 1) is fastened to the peripheral portion of the clutch plate 21 by rivets, or similar fasteners. The rear surface of the clutch plate 21 faces the front surface 19a of the pulley 19. The front surface functions as another clutch plate. The pulley 19 is operably connected to an automobile engine (not shown) by a belt (not shown). A annular solenoid coil 23 is supported by the front housing 1 to apply electromagnetic force (attraction force) to the clutch plate 21 through the front surface 19a of the pulley 19.
When the engine is driven with the viscous fluid heater connected to the exterior heater circuit, the rotational force of the engine is transmitted to the pulley 19. The solenoid coil 23 of the electromagnetic clutch 17 is then excited to move the clutch plate 21 against the force of the leaf spring 22. This engages the clutch plate 21 with the front surface 19a of the pulley 19. The engagement transmits the rotation of the pulley 19 to the drive shaft 8 through the clutch plate 21 and the support ring 20. The rotational speed of the drive shaft 8 is varied in correspondence with the speed of the exterior drive source, or the engine.
Rotation of the drive shaft 8 orbits the eccentric shaft 11 about the axis of the drive shaft 8. The rotor 12 orbits integrally with the eccentric shaft 11 in the heating chamber 7. In this state, as shown in FIG. 4, the rotor 12 moves from position A to position B, then to position C, and finally to position D. The orbiting movement of the rotor 12 shears the silicone oil F, which is included between the rear surface 12a of the rotor and the rear wall of the heating chamber 7. This produces fluid friction and heats the silicone oil F.
Heat exchange takes place between the heated silicone oil F and the coolant circulating through the water jacket 14. The heated coolant is then returned to the heater circuit (not shown) to warm the passenger compartment. The water jacket 14 is located outside the heating chamber 7 adjacent to the rear surface 12a of the rotor 12. In other words, the water jacket 14 is located near the heat source. This efficiently transfers the heat generated in the heating chamber to the water jacket 14. Thus, the heat exchange efficiency between the silicone oil F in the heating chamber and the coolant circulating through the water jacket 14 is improved.
Viscous fluid occupies the space provided in the heating chamber 7 to allow orbiting of the rotor 12. This space includes the first gap δ and the second gap ε. The first gap δ is between the rear surface 12a of the rotor 12 and the rear wall of the heating chamber 7. The variable second gap ε is between the peripheral surface of the rotor 12 and the peripheral wall of the heating chamber 7. The second gap ε is connected with the first gap δ. As the rotor 12 orbits, the second gap ε varies. This moves the silicone oil F in the second gap ε in correspondence with the orbiting of the rotor 12. The orbiting of the rotor 12 also moves the silicone oil F out of the first gap δ and into the second gap ε. In this manner, the silicone oil F in the first gap δ is continuously replaced by silicone oil F from the second gap ε. Accordingly, continuous shearing of the silicone oil F over a long period of time is avoided. Therefore, the same silicone oil F is not sheared constantly and kept at a high temperature for a long period of time, even if the engine runs continuously at a high speed. This prevents rapid deterioration of the silicone oil F.
When the rotor 12 orbits about the drive shaft 8 in the heating chamber 7, the silicone oil F applies a reaction force to the rotor 12 in a direction opposite to the orbiting direction of the rotor 12. However, since the rotor 12 is fixed to the eccentric shaft 11, relative rotation between the rotor 12 and the eccentric shaft 11 is prohibited. As a result, the force applied to the rotor 12 by the rotation of the drive shaft 8 results in additional fluid friction in the silicone oil F.
The fine 2e guide the coolant along a predetermined circulating route in the water jacket 14. This eliminates problems such as insufficient circulation and stationary coolant in the water jacket 14. Accordingly, heat exchange takes place efficiently between the heating chamber 7 and the coolant circulating through the water jacket 14.
Each fin 2e projects into the water jacket 14 in the vicinity of the heating chamber 7. This increases the heat surface transfer area between the coolant, which circulates through the water jacket 14, and the walls adjacent to the heating chamber 7. Thus, the fins 2e further improve the heat exchange efficiency. Furthermore, each fin 2e is spaced from the opposing rear plate 3. This prevents heat from being conducted directly from the fins 2e to the rear plate 3, which would then transfer the heat externally. Thus, the efficiency of heat exchange between the heating chamber 7 and the coolant circulating in the water jacket 14 is further improved.
The reservoir 13 reserves silicone oil P. During orbiting of the rotor 12, the silicone oil F in the heating chamber 7 flows into the reservoir 13 through the passage 2c, while the silicone oil F in the reservoir 13 flows into the heating chamber 7 through the passage 2b. Thus, heat is not generated within the same silicone oil F for a long period of time. This prolongs the life of silicone oil F.
The rear housing 2 is formed of a material having superior heat conductivity. This efficiently conducts heat generated in the heating chamber 7 to the coolant circulating in the water jacket 14. Furthermore, the rear plate 3 is formed of a material having low heat conductivity. This hinders conduction of heat from the water jacket 14 through the rear plate 3.
A further embodiment according to the present invention will now be described with reference to FIG. 5.
In this embodiment, the silicone oil F (viscous fluid) is sheared in the heating chamber 7 by both the front and rear surfaces of the rotor 24.
The rotor 24 includes a large diameter portion 24a and a small diameter portion 24d. The large diameter portion 24a is provided on the front side of the rotor 24, while the small diameter portion 24d is provided on the rear side of the rotor 24. A rear surface 24b is defined on the rear end of the large diameter portion 24a, while a front surface 24c is defined on the front and of the large diameter portion 24a. A large bore 7a is provided in the heating chamber 7 in correspondence with the large diameter portion of the rotor 24. A wall surface 7c is defined in the large bore 7a facing the front surface 24c of the small diameter portion 24d. The heating chamber 7 also includes a small bore 7b in correspondence with the small diameter portion 24d of the rotor 24. The diameter of the small bore 7b permits enough space to permit the orbiting of the rotor 24, while also providing maximum area for the wall surface 7c.
A gap ζ is provided between the front surface 24c of the small diameter portion 24d and the opposing wall surface 7c, while a gap δ is provided between the rear surface 24b of the large diameter portion 24a and the opposing wall of the rear housing 2. The dimension of gap δ is the same an that of the first embodiment. In the same manner as the first embodiment, a variable gap ε is provided between the large diameter portion 24d of the rotor 24 and the radially opposing peripheral wall of the large bore 7a. A further variable gap η is provided between the small diameter portion 24d of the rotor 24 and the radially opposing peripheral wall the small bore 7b. The dimensions of gap ε and gap η (when minimum) are equal to each other.
Like the first embodiment, in this embodiment, the rotor 24 orbits in the heating chamber 7 during rotation of the drive shaft 8. This shears and heats the silicone oil F located between the rear surface 24b of the large diameter portion and the opposing wall of the rear housing 2 and the silicone oil F between the front surface 24c of the small diameter portion 24d and the wall surface 7c of the heating chamber 7. Simultaneously, the orbiting of the rotor 24 moves the silicone oil F in the gaps ε and η and circulates the silicone oil F. Thus, the same silicone oil F is not sheared for a significant length of time. This prevents deterioration of the silicone oil F.
In this embodiment, the silicone oil F between the front surface 24c of the rotor 24 and the opposing wall 7c of the heating chamber 7 is also sheared to produce heat. This improves the heating output of tho viscous fluid heater per rotation of the drive shaft 8. Furthermore, the area of the rotor 12 that contributes to heating is increased without enlarging the rotor, and the volume of the rotor is smaller. The provides a lighter rotor and reduces power consumption.
A third embodiment according to the present invention will now be described with reference to FIGS. 6(a), 6(b).
In the third embodiment, the axial lengths of the rotor 12 and the heating chamber 7 are shorter than that of the above embodiments. Furthermore, a flap 25, functioning as a valve, is provided in the reservoir 13 to selectively open and close the passage 2b.
The flap 25 is formed from a material such as a bimetal or a shape memory alloy. When the temperature of the heating chamber 7 exceeds a predetermined value, the flap 25 closes the passage 2b. The flap 25 opens the passage 2b when the temperature of the heating chamber 7 is lower than the predetermined value. The predetermined temperature is one at which the silicone oil F rapidly deteriorates. The temperature at which the flap 25 starts to deform is not equal to but is lower than the predetermined temperature. The temperature at which the flap 25 closes is selected in consideration of the difference between the temperature in the heating chamber 7 and the temperature at the location of the flap 25.
When the temperature of the heating chamber 7 is lower than the predetermined value,, the flap 25 is maintained at an open state, as shown by the solid lines in FIGS. 6(a) and 6(b). This permits the silicone oil F in the reservoir 13 to flow into the heating chamber 7. As a result, the silicone oil F circulates between the heating chamber 7 and the reservoir 13. However, when the temperature of the heating chamber 7 exceeds the predetermined value, the flap 25 deforms to a closed state, as shown by the dotted lines in FIG. 6(b). This hinders the flow of the silicone oil F from the reservoir 13 to the heating chamber 7. When the passage 2b is closed, continuous rotation of the rotor 12 causes the silicone oil F to continue returning to the reservoir 13 through the passage 2c. This decreases the amount of the silicone oil F in the heating chamber 7 and reduces the heating of the silicone oil F. Consequently, overheating of the silicone oil F is prevented. Therefore, the life of the silicone oil F is prolonged in comparison with the first two embodiments.
It should be apparent to those skilled in the art that the present invention may be embodied in many other specific forms without departing from the spirit or scope of the invention. Particularly, the present invention may also be modified as described below.
FIGS. 7 and 8 each show variations of the water jacket in further embodiments. In the embodiment of FIG. 7, an additional water jacket 26 is defined in the front housing 1 by a generally annular groove, which is opened toward the rear housing 2. A further gasket 6 is arranged between the front housing 1 and the rear housing 2 to prevent leakage of coolant from the water jacket 26. The water jacket 26 is provided with an inlet and an outlet (neither are shown). Coolant from the heater circuit (not shown) is distributed between the two water jackets 14, 26. The coolant streams discharged from the water jackets 14, 26 are joined when returning to the heater circuit.
In the embodiment shown in FIG. 8, most of the heating chamber 7 is defined in the rear housing 2. A generally annular groove 27 extends around the heating chamber 7 and communicates with the water jacket 14.
The viscous fluid heaters of the embodiments shown in FIGS. 7 and 8 both have a higher heat exchange efficiency in comparison with a viscous fluid heater that has a water jacket provided only in the wall of the heating chamber 7 adjacent to the rear surface 12a of the rotor 12.
FIGS. 9(a), 9(b), and 9(c) each show shearing force enhancing pattern that is employed in a further embodiment. Each pattern is formed by recessed areas in the rear surface 12a of the rotor 12 or the rear surface 24b of the rotor 24 to improve the shearing force applied to the viscous fluid. The dimension of the gap a between the rear surface 12a or 24b and the opposing wall of the heating chamber 7 is varied by each recessed area during orbiting of the rotor 12 or 24. For example, FIG. 9(a) shows a plurality of circular bores (or recesses) 28 that are formed in the rear surface 12a. FIG. 9(b) shows a plurality of grooves 29 that extend radially in the rear surface 12a of the rotor 12. FIG. 9(c) shows a plurality of radial slits 30 that extend axially through the rotor 12. It is preferable that the corners formed by the bores 28, the grooves 29, and the slits 30 not be chamfered.
The shearing force enhancing pattern, on the rear surface 12a reduces the effective heating area of the rear surface 12a. However, the dimension of the gap between the rear surface 12a of the rotor 12 and the opposing wall of the heating chamber 7 changes as the rotor 12 orbits and rotates. During orbiting of the rotor 12, as the dimension of the gap increases, that is, as the bores 28, grooves 29, or slits 30 come to face the opposing wall of the heating chamber 7, the shearing force of the rotor 12 is increased. However, if the recessed areas dominate a large portion of the rear surface 12a, the effective heating area will be insufficient. This would decrease the amount of heat generated by the viscous fluid heater. Accordingly, it is preferable that the total recessed areas (slits, holes, etc.) not exceed 20 percent of the area of the rear surface 12a.
Furthermore, gas contained in the viscous fluid is collected by the bores 28, the grooves 29, or the slits 30. This eliminates most of the gas in the gap between the rear surface 12a and the opposing wall of the rear housing 2 when generating heat. Consequently, the shearing force is applied more efficiently to the viscous fluid.
The machining of the bores 28 is more simple than the machining of the grooves 29 or the slits 30. Furthermore, the bores 28 need not be circular and may take arbitrary shapes. For example, the bore 28 may be polygonal, triangular, rectangular, or oval. Additionally, the bores 28 may be extended through the rotor 12.
The grooves 29 and the slits 30 increase the places at which the gap between the rear surface 12a and the opposing wall of the heating chamber 7 varies when the rotor 12 orbits. Furthermore, if the amount of gas collected in the grooves 29 or the slits 30 becomes large, the gas escapes into the heating chamber 7 from the peripheral surface of the rotor 12. Therefore, the gas does not return to the gap between the rear surface 12a of the rotor 12 and the opposing wall of the heating chamber 7. As a result, the shearing effect is not degraded.
In the shearing force (enhancing pattern, the bores 28, the grooves 29, and the slits 30 may be combined with one another.
When the viscous fluid is sheared at opposite sides of the rotor 24, as in the embodiment of FIG. 5, the bores 28, the grooves 29, or the slits 30 may be provided on surfaces 24b, 24c of the rotor 24. A shearing force enhancing pattern provided on the front surface 24c has the same advantages as one provided on the rear surface 24b.
Instead of applying the shearing force enhancing pattern to the rear surfaces 12a, 24b or the front surface 24c, the pattern may be provided in the walls of the heating chamber 7 facing the surfaced 12a, 24b, or 24c. A shearing force enhancing pattern provided on the walls of the heating chamber 7 has the same advantages as one provided on the rotors 12, 24. Also, the shearing force enhancing pattern may be provided on both the rotor 12, 24 and the walls of the heating chamber 7.
The shearing force enhancing pattern may be constituted by projections that project from the surfaces of the rotors 12, 24 or from the walls of the heating chamber 7 opposing the rotor surfaces. The height of each projection (the projecting amount) must be smaller than the optimum distance between the rotor 12, 24 and the opposing wall of the heating chamber 7 for shearing the viscous fluid effectively when there are no projections. Thus, the projections need to be machined accurately. Although the machining of the projections is complicated, the added heating efficiency of the projections is higher than that of the bores 28, the grooves 29, or the slits 30.
FIGS. 10(a) and 10(b) each show variations of the rotor 12 that are employed in further embodiments. The shape of the rotor 12, 24 is not restricted. For example, as shown in FIG. 10(a), the rotor 12 may be oval, or as shown in FIG. 10(b), the rotor 12 may be arcuate. The rotor 12, 24 may also be polygonal like a triangle or a rectangle. An oval or arcuate form decreases the volume of the rotor 12, 24 with respect to the volume of the heating chamber 7. This increases the proportion of the viscous fluid in the heating chamber 7 that does not undergo shearing with respect to the proportion of the viscous fluid that undergoes shearing. Accordingly, the life of the viscous fluid is prolonged.
The reservoir 13 may be eliminated from the structure of the viscous fluid heater. The space provided to permit orbiting of the rotor 12, 24 may be used to accommodate a relatively large amount of viscous fluid. Thus, even without the reservoir 13, the life of the viscous fluid may be prolonged when compared to prior art viscous fluid heaters. Furthermore, if the reservoir 13 is eliminated, the space of the reservoir 13 may be used to enlarge the water jacket 14. This would increase the efficiency of heat exchange between the heating chamber 7 and the coolant in the water jacket 14.
The electromagnetic clutch 17 may be eliminated from the structure of the viscous fluid heater. In this case, the pulley 19 in supported by the drive shaft 8 to rotate the pulley 19 integrally with the drive shaft 8. The pulley 19 transmits the drive force of the engine directly to the drive shaft 8.
Any type of media that produces fluid friction when sheared by a rotor and generates heat may be used as the viscous fluid. Thus, the viscous fluid 15 not limited to high viscosity fluid or semi-fluids such as silicone oil.
Therefore, the present examples and embodiments are to be considered as illustrative and not restrictive and the invention is not to be limited to the details given herein, but may be modified within the cope of the appended claims.
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A viscous fluid type heater including a heating chamber and a heat exchange chamber, which is adjacent to the heating chamber. The heating chamber contains viscous fluid and a rotor. The heat exchange chamber is connected to a coolant circuit. The rotor is rotated by a drive shaft to shear the viscous fluid and produce heat in the heating chamber. The heat is transferred to the heat exchange chamber from the heating chamber to heat coolant passing through the heat exchange chamber and circulating in the fluid circuit. The heating chamber has a rear wall. The rotor has a rear surface facing the rear wall. Viscous fluid located between the wall and the rotor is sheared when the rotor rotates. A support shaft is supported by the rotor. The support shaft is eccentrically coupled to the drive shaft, which forces the viscous fluid located between the wall and the rotor to be periodically displaced. This prevents prolonged heating of any part of the fluid, which extends the life of the fluid.
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BACKGROUND OF THE INVENTION
This invention relates to an FM receiver and more particularly to an FM stereophonic receiver equipped with a noise pulse suppression device.
Noise due to automobile electric motor wipers, particularly noise pulses emanating from automobile ignitions cause trouble in an FM receiver. Such noise pulse is capable of suppression to a limited extent by a limiter circuit after intermediate frequency amplification. However, in practice, the noise pulse is not sufficiently reduced or eliminated by such a limiter circuit. Heretofore, in order to more sufficiently remove the noise pulses, a noise suppression circuit 10 as shown in FIG. 1 has been employed.
Referring to FIG. 1, an FM detected composite signal containing a 19 KHz pilot signal, which is the output of an FM detection circuit 1, is delivered to both a delay circuit 2 and a noise pulse detection circuit 3 comprising a high-pass filter. The afore-mentioned noise pulse is detected out from the composite signal by means of the high-pass filter and then the composite signal is delivered to a shaping circuit 4 in the timed relationship with the occurrence of the noise pulse. The shaping circuit 4 constitutes a monostable multivibrator, which produces control pulses for a predetermined duration. On the other hand, the composite signal passing through the delay circuit 2 is applied to a gate circuit 5 whose gating operation is controlled in response to the output pulses of the multivibrator (4).
The gate circuit 5 operates to prevent the composite signal from being delivered to the next stage during the presence of the output pulses of the multivibrator (4). For the time period when the output pulse of the multivibrator (4) is applied to the gate circuit 5, the output of a level hold circuit 6 is delivered to the next stage. Hence, the level hold circuit 6 functions to hold the composite signal at the level immediately before the cut-off operation of the gate circuit 5. The outputs of the gate circuit 5 and the level hold circuit 6 are delivered to a multiplex (MPX) demodulator circuit 8 where the composite signal is separated into signals for right and left channels.
FIGS. 2(a) through 2(c) are waveform diagrams for operational description of the circuit shown in FIG. 1. FIG. 2(a) is the FM detected composite signal containing the 19 KHz pilot signal. Assuming now that a noise pulse (not shown) is superimposed on the composite signal at a time interval T between t 1 and t 2 , the multivibrator (4) operates in response to the output of high-pass filter (3) to produce inhibit pulses for the duration of T. The gate circuit 5 is then put in a cut-off condition for the duration of T, and therefore the FM detected composite signal is not delivered to the next stage. In this situation, the level hold circuit 6 holds the level of the composite signal at the time t 1 and the same is transmitted to the MPX demodulator circuit 8. The signal as shown in FIG. 2(b) is applied to the MPX demodulator circuit 8. The signal shown in FIG. 2(b) is demodulated into a waveform as shown in FIG. 2(c) after low-pass filtering in the demodulator circuit 8.
As can be appreciated, although the noise pulse introduced at the time interval T is removed, unwanted noise still remains as a part of the audio signal. Particularly, in the case where the audio signal is minute relative to the 19 KHz pilot signal, unwanted noise proportional to the level of the pilot signal becomes notable as can be seen from FIG. 2(c).
SUMMARY OF THE INVENTION
Accordingly, an object of the present invention is to provide an FM receiver with a noise pulse suppression device capable of completely eliminating the aforementioned unwanted noises.
Briefly, and in accordance with the present invention, when the gate circuit 5 of FIG. 1 is in the cut-off condition so as not to transmit the composite signal to the MPX demodulator circuit 8, a signal with the same frequency and the same phase as the 19 KHz pilot signal is superimposed on the output of the level hold circuit 6. Hence the unwanted noise component caused by the pilot signal is suppressed. A signal locked with the pilot signal derived from a phase locked loop in the MPX demodulator circuit 8 is employed for the signal to be superimposed thereon.
BRIEF DESCRIPTION OF THE DRAWINGS
In the drawings:
FIG. 1 is a block diagram showing a conventional noise suppression device;
FIGS. 2(a) through 2(c) are waveform diagrams for description of the device shown in FIG. 1;
FIG. 3 is a block diagram showing one embodiment according to the present invention;
FIG. 4 is a circuit diagram showing an example of essential sections shown in FIG. 3; and
FIG. 5 is a block diagram showing another embodiment according to the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
One embodiment according to the present invention will now be described with reference to FIGS. 3 through 6.
FIG. 3 is a block diagram illustrating one preferred embodiment of the present invention, in which like numerals refer to like sections shown in FIG. 1. The MPX demodulator circuit 8 is a conventionally known circuit construction employing a phase locked loop (PLL) 9 to obtain a 38 KHz subcarrier signal locked with the 19 KHz pilot signal. Specifically, a composite signal received from the noise suppression circuit 7 is augmented by means of an amplifier 10 and then applied to a decoder 11. The pilot signal is applied to one input of a phase comparator 13. A voltage controlled oscillator (VC0) 16 provides at its output a 76 KHz signal which is then subjected to frequency division into 38 KHz by means of a frequency divider 17. The output of the frequency divider 17 is further subjected to frequency division into 19 KHz by means of a second frequency divider 18. The output of the frequency divider 18 is applied to the other input of the phase comparator 13.
The output of the phase comparator 13 is applied through a low-pass filter 14 to a d.c. amplifier 15, and thereafter to VCO 16 for control to the phase of oscillation frequency of the VCO 16. The 38 KHz sub-carrier frequency from the frequency divider 17 is applied through a switching circuit 19 to the decoder 11. The output of the decoder 11 passes through a low-pass filter 12, from which signals for left and right channels are derived.
The switching circuit 19 is employed to prevent the sub-carrier from being transmitted to the decoder 11 when a monophonic signal is received. For achieving this result, a discrimination circuit 20 is provided to discriminate the presence of the pilot signal from the composite signal. More specifically, the pilot signal output derived from the amplifier 10 is applied to one input of a phase comparator 21 and a 19 KHz output of the frequency divider 18 is applied to the other input thereof through a flip-flop 22 so that the output of the flip-flop 22 is the same phase as that of the pilot signal. The output of the comparator 21 is delivered through a low-pass filter 23 to a control signal generating section 24 and the output controls a stereo indicator (ST IND) and the aforementioned switching circuit 19.
In the present invention, the 19 KHz signal (which corresponds in FIG. 3 to the output of the flip-flop 22) is superimposed on the output signal of the level hold circuit 6 only for the interval T. The 19 KHz signal is completely locked with the pilot signal obtained through the PLL circuit 9 in the demodulator circuit 8. To implement this signal processing, there are provided a waveform transformation circuit 26, an automatic gain control (AGC) drive circuit 27, an AGC circuit 28 and a level setting circuit 29. The 19 KHz output signal of the flip-flop 22 in the PLL circuit 9 is applied through a gate circuit 25 to the input of the waveform transformation circuit 26. The gating operation of the gate circuit 25 is controlled by the control signal obtained from the pilot signal discrimination circuit 20. In the case of receiving a monophonic broadcasting program, the gate circuit 25 operates to cut-off the 19 KHz signal and to prevent a free-running frequency (19 KHz) signal produced in the PLL circuit from being superimposed on the output signal of the hold circuit 6. This prevents misoperation in the case of monophonic operation.
The waveform transformation circuit 26 is employed to transform the rectangular waveform signal obtained through the PLL circuit 9 into a sine waveform signal. The sine waveform signal is then applied to the AGC circuit 28 which operates in correspondence with the level of the pilot signal to supply the 19 KHz signal with the same level as that of the pilot signal to the MPX demodulator circuit 8 when the gate circuit 5 is in the cut-off condition.
FIG. 4 is a circuit diagram showing the essential parts of the present invention shown in FIG. 3.
The 19 KHz signal obtained through the PLL circuit 9 is applied to the base of a transistor Q 1 included in the gate circuit 25 via a series-connected resistor R 1 and capacitor C 1 . The base of the transistor Q 1 is coupled to a positive power source +V through a resistor R 2 and receives the control signal through resistors R 3 and R 4 .
The waveform transformation circuit 26 includes a transistor Q 2 having at its collector a parallel-connected capacitor C 2 and coil L for tuning the 19 KHz signal. The emitters of transistors Q 1 and Q 2 are commonly connected, thereby constituting a differential amplifier. A reference voltage is applied to the base of the transistor Q 2 using resistors R 5 and R 6 . The commonly connected emitters of the transistors Q 1 and Q 2 are grounded via the collector emitter path of a transistor Q 3 and a resistor R 7 .
Accordingly, if the level of the control signal is set to be high at the time of monophonic broadcasting whereas the level thereof is set to be low at the time of stereophonic broadcasting, the transistor Q 1 reaches a saturated condition and the transistor Q 2 is in a non-conductive condition in the former case. Both the transistors Q 1 and Q 2 become normally conductive in the latter case. Thus, the purpose as a gate is attained by the transistor Q 1 . The 19 KHz signal transformed into a sine waveform by the tuning elements is applied through a capacitor C 7 to the next stage.
The output of the phase comparator 21 passes through the low-pass filter 23 comprising a capacitor C 5 to thereby convert the output of the phase comparator 21 into a d.c. signal, and the level is varied in proportion to the level of the pilot signal. Resistors R 7 and R 8 are provided for buffering and do not affect the operations of the phase comparator 21 and the low pass-filter 23. When the pilot signal is applied to the phase comparator 21, the d.c. voltage is yielded between points A and A', which is then augmented by a differential amplifier comprising transistors Q 4 and Q 5 . The output of the differential amplifier is applied to the base of a transistor Q 6 via a resistor R 10 . As a result, the transistor Q 6 is rendered conductive and a current flows through resistors R 12 and R 13 coupled to the collector thereof.
The juncture point B between the resistors R 12 and R 13 is connected to the base of the transistor Q 3 , thereby biasing the transistor Q 3 when the transistor Q 6 is conductive. The signal to be supplied to the MPX demodulator circuit 8 when the gate circuit 5 is in the cut-off condition is adjusted by a variable resistor VR so as to be same level as that of the pilot signal. Accordingly, regardless of the differential level in the pilot signal because of the broadcasting station signal, the 19 KHz signal with the same level as that of the pilot signal being received is supplied to the MPX demodulator circuit 8.
In the level transformation circuit 29, the applied input signal through the capacitor C 7 is subjected to an impedance transformation by an emitter-follower circuit comprising a transistor Q 7 and resistors R 14 and R 15 , and is then applied to a level setting resistor VR via a resistor R 16 . The level setting resistor VR is used as the series connected resistor to a capacitor C 8 included also in the level hold circuit 6. The transistor Q 8 operates as a constant current source of the differential amplifier comprising the transistors Q 1 and Q 2 . Since in the differential amplifier the gain thereof varies depending on the collector currents flowing in the respective transistors, the gain of the waveform transformation circuit 26 can be controlled by controlling the base bias of the transistor Q 4 . This is the AGC operation, which is implemented in accordance with the level variation of the pilot signal being received. Accordingly, the 19 KHz signal to be supplied to the MPX demodulator circuit 8 when the gate circuit 5 is in cut-off condition is automatically controlled so that the level thereof is in coincidence with that of the pilot signal being received.
In the circuit construction as described, the output part of the delay circuit 2 which is the preceeding stage of the gate circuit 5 is an emitter-follower construction as shown in FIG. 4 comprising a transistor Q 8 and a resistor R 17 . In normal operation where the gate circuit 5 transmits the composite signal, the impedance at point C, i.e. the output point of the gate circuit 5 is low in equivalent to the output impedance of the emitter-follower of the delay circuit 2, which may be in the order of 20 Ohms. Conversely, the impedance of the level setting circuit 29 as viewed from a point D, i.e. the juncture point of the capacitor C 8 and the variable resistor VR is relatively high in comparison with the impedance at the point A. This is because the former impedance is equivalent to the parallel resistance of the series-connected resistor R 16 and emitter-follower (Q 7 ) and the resistance of resistor VR, wherein the resistance of resistors VR and R 16 are in the order of several kilo Ohms. Accordingly, due to the impedance ratio, the output signal of the level setting circuit 29 is attenuated and does not appear on the point C. However, in the case where the gate circuit 5 carries out a cut-off operation, a signal appears on the point C such that the 19 KHz signal is superimposed on the output signal of the level hold circuit 6.
As described, only during the cut-off interval T the 19 KHz signal is superimposed on the composite signal. Hence, the object of the present invention is achieved.
FIG. 5 is a block diagram showing another embodiment of the present invention. The output of a 19 KHz level setting circuit 29 is applied to the gate circuit 5 which operates to selectively switch the composite FM detected signal obtained from the output of the delay circuit 2 and the 19 KHz signal obtained from the level setting circuit 29 and then transmit it to the next state. Therefore, by controlling the gating operation of the gate circuit 5 in response to the output signal of the pulse shaping circuit 4, the 19 KHz signal is superimposed on the output of the level hold circuit 6 only during the time interval T.
As is described in detail, according to the present invention, during the production of unwanted noise pulse emanating from, for example, automobile ignitions, the transmission of the composite signal is interrupted by the gate circuit 5 and the signal with the same phase and the same frequency as those of the pilot signal is superimposed on the composite signal of the level immediately before the transmission of the composite signal is interrupted. Accordingly, the present invention is advantageous in that so-called switching noise as produced in the conventional circuit is suppressed and the circuit construction is simplified because the signal to be superimposed thereon is derived from the multiplex demodulator circuit.
In the case where the time interval (T) is approximately 30 to 50 micro seconds during which the gate circuit 5 carries out the cut-off operation due to the pulse noise, the time for releasing the lock of PLL circuit due to the intermission of the pilot signal is determined by the time constant of the low-pass filter 14 and which is generally in the order of several micro seconds. Therefore, no inconvenience is caused in the operation of the demodulator circuit by the intermission of the pilot signal due to the cut-off operation of the gate circuit 5.
While the invention has been explained with respect to the preferred embodiments, it is apparent that modifications can be made without departing from the scope thereof.
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An FM receiver including a noise pulse detection circuit which receives an FM detected signal containing a pilot signal and produces a control signal when a noise pulse is detected. A gate is operable to interrupt the transmission of the FM detected signal to the subsequent stage for the duration of the presence of the noise pulse responsive to the control signal and a holding circuit holds the FM detected signal of the level immediately before the interrupting operation of the gate. A multiplex demodulator receives outputs of the gate and the holding circuit for demodulating an applied FM detected signal. A signal generator is provided in the multiplex demodulator for generating a signal whose frequency and phase are same as those of the pilot signal. A superimposing circuit superimposes a signal obtained from the signal generator on the output of the holding circuit for the duration of the presence of the noise pulse.
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BACKGROUND OF THE INVENTION
The present invention relates to a method and apparatus for producing an air textured yarn having a relatively low residual shrinkage.
Methods and apparatus are known from German Patent 32 10 784, in which the yarn to be textured is supplied as a preoriented, thermoplastic yarn. The yarn is drawn in a draw zone and subsequently extended in an air nozzle to form loops, curls, bows and the like. The yarn produced has a residual shrinkage. In the scope of the present application, the phase "residual shrinkage" is intended to mean the tendency (shrinkage tendency) of the yarn to shrink when being heated, for example, by hot air or hot water.
Shrinkage is a shortening of the yarn, which occurs in fact when it is heated, and which is expressed by the formula (L1-L2)×100/L1%, with L1being the original and L2 the shortened length of the yarn. The shrinkage cannot be greater than the previously existing residual shrinkage. However, a residual shrinkage can still remain despite the shrinkage.
If the known method is applied, the residual shrinkage, i.e. the tendency to shrink can be reduced only by a suitable aftertreatment subsequent to the process. Although it is possible to reduce the residual shrinkage of the yarn by such measures for aftertreatment of the shrinkage, these measures, however, have considerable disadvantages. This applies particularly to textured yarns, since the aftertreatment subsequently affects or even damages the crimp. Primarily, a shrinkage treatment can be carried out intensively only when the yarn is subjected to "contact heating," i.e. when the yarn passes over a hot plate of a heated godet. However, this procedure is generally not suitable for textured yarns, because it results in an ironing effect. This means that a previously imparted yarn texture is again removed in part, primarily on one side of the yarn, by its contact with the hot surface.
A method of aftertreatment for the purpose of reducing the shrinkage of an air textured yarn is known from U.S. Pat. No. 3,892,020 which corresponds to DE-OS 23 59 102. In this process, the air textured yarn is wound onto a very soft package under little tension of less than 0.4 grams/denier. This package is subsequently dyed in a heated dye liquor. As a result thereof a shrinkage is started, and the residual shrinkage remaining in the yarn is reduced accordingly. However, this method is not adapted to carry out the treatment for reducing the residual shrinkage on an air texturing machine. Particularly disadvantageous is that the package must be wound under a low yarn tension, which adversely affects the transportability of the package. Furthermore, the package and the yarn are damaged by the increased yarn tension, which builds as the shrinkage becomes effective.
The residual shrinkage can also be reduced prior to texturing. To this end, it is known that a thermoplastic drawing process of thermoplastic yarns can be followed by a treatment for reducing shrinkage in a relaxation zone. The relaxation zone follows the actual draw zone, and is formed between two godets or feed systems, with the yarn being heated in the relaxation zone. As a result thereof the length of the yarn path and thus the height of the air texturing machine is necessarily increased. Primarily, however, this relaxation treatment will always result in the problem that the reduction of the shrinkage in such a relaxation zone has its limits, inasmuch as the tension of a yarn traveling between godets cannot be reduced to any desired extent, and consequently the shrinkage is dependent on the limited speed difference of the godets.
The above is based on the fact that a yarn must always advance in a straight line between two feed systems and consequently be under a certain minimum tension. The shrinkage which occurs in fact results from the state of equilibrium between the shrinkage tendency on the one hand and the yarn tension on the other.
A method of reducing residual shrinkage, in which a multifilament yarn is simultaneously interlaced or entangled, is disclosed in U.S. Pat. No. 3,069,836. In this method, the yarn, which is first drawn between two godets assisted by an unheated draw pin, passes through a relaxation zone, in which the entry speed is greater than the exit speed. While in the relaxation zone, the yarn passes through a nozzle, which is supplied by a heated gas. The shrinkage which is this accomplished is, as aforesaid, dependent on the difference of these speeds. The application of hot air serves both to produce a shrinkage and to make a yarn which has its filaments entangled. The method is not suitable for producing a crimp, because it will produce a yarn whose filaments are chemophysically changed in their inner structure by the action of heat during the air texturing operation. Even if curls and loops were produced in the filaments, such a crimp of this yarn would not be stable. This means that this crimp would again be removed from the yarn by the application of tensile forces. Tensile forces, which suffice to remove this crimp, however, occur already as a result of the shrinkage in the relaxation zone, as well as also during the aftertreatment by subsequent stabilizing and heat setting processes, which are provided, according to U.S. Pat. No. 32,047, for improving the length stability of the yarn, and in particular in weaving and knitting. As a result, such a yarn would not be usable as a crimped yarn.
An air texturing method in the meaning of the present application is understood to be a method, in which a continuous, synthetic yarn, which comprises a plurality of individual filaments, is subjected to the action of an air texturing nozzle. In the air texturing nozzle, an unheated air jet is blown onto the yarn. As a result, the individual filaments are deformed to loops, curls, bows or the like without thereby substantially changing the chemophysical structure of the filaments. The filaments extending substantially parallel at first are only geometrically relocated in an irregular form, thereby forming in particular loops, curls and bows. A particularly suitable method of producing high-quality yarns is disclosed in German Patent 27 49 867 and corresponding U.S. Pat. No. 32,047. Suitable nozzles are shown in the dissertation "Die Texturierung von Filamentgarnen im Luftstrom" by Bock, Aachen 1984/1985.
It is accordingly an object of the present invention to efficiently produce an air textured yarn, which is low in shrinkage, i.e., has little residual shrinkage.
SUMMARY OF THE INVENTION
The above and other objects and advantages of the present invention are achieved in the embodiments illustrated herein by the provision of a method and apparatus for producing an air textured yarn and which includes the steps of advancing a continuous filament yarn along a path of travel, and drawing the advancing yarn in a drawing zone positioned along the path of travel. The drawing step includes guiding the advancing yarn into contact with a yarn engaging member and then about a positively rotated godet which serves to withdraw the advancing yarn from the yarn engaging member and draw the same. Also, the drawing godet is heated so as to heat the yarn to a temperature which is higher than the second order transition temperature of the yarn. The advancing yarn is guided from the heated godet to an air jet nozzle while permitting the heated yarn to shrink and thereby reduce the residual shrinkage, and a jet of unheated air is applied to the advancing yarn while passing the advancing yarn through the air jet nozzle and so as to impart loops, curls, bows and the like to the advancing yarn. Also, the unheated air acts to cool the yarn to a temperature below the second order transition temperature of the yarn. The advancing yarn is then withdrawn from the air jet nozzle, and wound into a package.
The present invention permits the residual shrinkage to be reduced to a much greater extent than in the above noted known methods. A special advantage of the invention is that texturing is not adversely affected. Of particular importance in this regard is that an intensive heating of the yarn occurs. Consequently, the yarn can be heated to a temperature above the second order transition temperature of the yarn, so that the crystalline structure, which is firmly anchored up to this temperature, softens and inner tensions diminish. On the other hand, however, the yarn is cooled in the air texturing nozzle to a very great extent, so that shrinkage is stopped and texturing occurs on the cold yarn.
The present invention represents a fortunate integration of the relaxation process into the air texturing process. The yarn is heated at the outlet end of the draw zone, and an intensive heating can be achieved by utilizing a heated godet in the drawing zone as described above. Also, very low yarn tensions in the texturing zones, and thus a good shrinkage effect, can be achieved.
In comparison with yarns which are treated by the described known methods of reducing residual shrinkage, the tendency to residual shrinkage of the yarns treated according to the present invention is less than half. This results from the fact that the method of the present invention does not have the aforesaid limitations of the known processes because, according to the present invention, the shrinkage to be adjusted is not dependent on the speed difference in the relaxation zone (entry speed less exit speed), and the yarn tension does not increase as a result of the occurrence of the shrinkage. Rather, the yarn tension to be adjusted and thus also the shrinkage are based alone on the tensile force of the air texturing nozzle.
In the preferred embodiment, the yarn is withdrawn from the heated godet by the air texturing nozzle under a tension of less than about 0.1 cN/dtex, and removed from the air texturing nozzle under a tension of less than about 0.05 cN/dtex. These low yarn tensions of the texturing zone are differently adjusted before and after the air texturing nozzle. In so doing, the yarn may be considerably deflected at the outlet end of the air texturing nozzle, preferably of about 90°. This deflection is novel as compared to the usual straight yarn path in the entangling process, and it is readily possible with air texturing nozzles.
The heat and shrinkage treatments of the present invention allow for any inadequacies or shortcomings of the preceding draw process to be overcome. More specifically, with the present invention it becomes possible to draw polyester yarns with an unheated draw pin, which so far has been possible only with nylon 6.6 yarns. Since the heat and shrinkage treatments occur prior to the texturing, inadequacies or shortcomings of the drawing process can no longer produce irregularities in the texturing result. Consequently, the present invention has the further benefit of reducing the expenditure for process and mechanical engineering to obtain a good, regular drawing, and of selectively texturing nylon 6.6 or polyester yarns, textile or industrial yarns on one machine without a change.
With the present invention, it thus becomes possible to draw the yarn by the sensible heat developing in the drawing operation, thereby eliminating already prior to the actual texturing operation any irregularities of the drawing process, which otherwise occur in such a process, by the subsequent intensive shrinkage treatment. It is thus possible to produce yarns having a great strength and the desired properties with regard to elongation and residual shrinkage.
The method of the present invention is particularly suitable for drawing and air texturing preoriented yarns, in particular polyester yarns (note U.S. Pat. No. 3,772,872).
The yarn tension decisive for the shrinkage is generated by the tensile force of the texturing nozzle. The tensile force of the texturing nozzle is again dependent on the speed of the yarn. The yarn speed is determined by the circumferential speed of the draw roll, which precedes the texturing nozzle. The difference between the circumferential speed of the draw roll and the feed system subsequent to the texturing nozzle is not decisive for the shrinkage because, according to the present invention, this difference is always greater than the amount of the desired shrinkage. The latter is defined alone by the tensile force of the nozzle and by the influence of the temperature of the draw roll. Stated otherwise, the overfeed of the yarn in the texturing zone is always greater than the shrinkage adjusted by the tensile force of the nozzle and the temperature of the draw roll. Thus, the overfeed O=(v5-v10)×100:v10, with v10=circumferential speed of the feed system subsequent to the texturing nozzle; and V5=circumferential speed of the draw roll. The shrinkage is expressed by the equation S=(L1-L2)×100:L1, with L1=original length of the yarn; and L2=length of the yarn after the shrinkage.
As a result of the fact that the overfeed is greater than the adjusted shrinkage, it is accomplished that the yarn can be crimped in the desired manner. The difference between overfeed and adjusted shrinkage is typically about 1-10% for industrial yarns, in which texturing serves in particular the purpose of roughening the yarn, so as to improve, for example, its running capability (sewing threads) or its adhesion to other materials (industrial fabrics, tire cord).
The difference between overfeed and adjusted shrinkage ranges from about 10% to 300% for textile yarns. What matters in the case of textile yarns is to influence appearance, touch, bulkiness and other properties in such a manner as is desired for clothing and other textile uses.
As a result of the present invention, it becomes possible to design and construct the air texturing machine, despite the additionally installed means for reducing the residual shrinkage, in a more simple manner and with a lesser overall height than previous standard air texturing machines, which do not offer the possibility of reducing the residual shrinkage.
BRIEF DESCRIPTION OF THE DRAWINGS
Some of the objects and advantages of the present invention having been stated, others will appear as the description proceeds, when taken in conjunction with the accompanying drawings, in which
FIG. 1 is a schematic view of an apparatus for producing an air textured yarn in accordance with the present invention;
FIG. 2 is a schematic representation of a device for measuring the residual shrinkage of a yarn;
FIG. 3 is a schematic view of a second embodiment of an apparatus for conducting comparative tests of the present invention; and
FIG. 4 is a schematic sectional view of an air texturing machine which embodies the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring more particularly to the drawings, FIG. 1 discloses an apparatus for practicing the present invention and wherein a preoriented yarn is unwound by a first feed system 3 from a supply package 1 over a yarn guide 2, and passes through a draw zone 4, whence it is withdrawn by a draw system (draw roll) 5. In the draw zone 4, the yarn is guided over a heatable draw pin 6 with a looping of 360°. Behind the draw roll 5, the yarn passes through an air texturing nozzle 7, which is supplied with unheated compressed air, and so that the yarn is cooled to an extent that shrinkage comes to a standstill. Thus when the yarn undergoes an air texturing treatment, it is not heated to its deformation point. Consequently, the deformations generated by the air jet treatment do not affect the chemophysical structure of the yarn. Upon its impact on the yarn, the air expands and consequently cools down further. As the air jet expands, the individual filaments of the multifilament manmade yarn are blown to loops, curls, bows, and the like. These geometrical deformations, which interlace and entangle, thereby form the texture of the yarn.
It should be emphasized that the air, which is supplied to the texturing nozzle, is unheated and has a temperature which is less than the temperature at which the crystalline structure of the yarn freezes, and consequently any shrinkage comes to a standstill. Normally, the air temperature is below 40° C. As the air expands, it is cooled further, and the air which leaves the nozzle has a temperature of less than 10° C. Taking into account that the texturing nozzle is operated by compressed air under a pressure of between 6 and 10 bar, the yarn previously heated by the draw roll is likewise considerably quenched in the texturing nozzle so that its temperature also drops below the temperature at which its crystalline structure freezes. Consequently, it should be understood that the yarn is cooled by the air texturing nozzle, thereby bringing the shrinkage to a standstill. This has the advantage that texturing by the formation of the loops, curls, bows and the like occurs only when shrinkage has come to a standstill. Consequently, texturing is no longer affected or influenced by the shrinkage. This is very significant, inasmuch as the production of an air textured yarn with a good length stability after texturing makes it necessary to first exert a tensile force on the yarn before the latter is compacted by subsequent further heat and shrinkage treatments. To this extent, reference is made to the above noted German Patent 27 49 867 and corresponding U.S. Pat. No. 32,047. As a result, the method of the present invention is a significant supplement to the known method.
As is schematically indicated in FIG. 1, the air channels 8, which are directed in the texturing nozzle 7 to a yarn channel 9, have a directional component in the direction of the yarn path. This allows the air texturing nozzle 7 to also exert an advancing effect and a tensile force on the yarn. The yarn leaves the air texturing nozzle 7 substantially under no tension, and the yarn is then deflected and guided to a feed system 10. The deflection ranges from 30° to 90°, preferably 90°, and is accomplished in that the feed system 10 does not extend along the axis of the yarn channel 9, but is laterally displaced therefrom. Consequently, the deflection does not occur by reason of the yarn traveling over a yarn guide, but rather the yarn leaving the air channel first continues to be advanced by the air jets in a straightline and must then change its direction toward the feed system 10. This type of deflection results in a substantial decrease of the yarn tension. Consequently, the yarn tension is higher between the draw roll 5 and the texturing nozzle 7 than the yarn tension, which increases again behind the texturing nozzle 7 after the deflection and before the feed system 10. The yarn tensions before and behind the air texturing nozzle amount, for example, to 6 cN and 5 cN.
Located downstream the feed system 10 is a suitable yarn treatment means, such as is particularly known from German Patent 27 49 867 and corresponding U.S. Pat. No. Re. 32,047. More specifically, the yarn can be drawn in a stabilizing zone between two godets without any elastic or plastic deformation and without being heated. Alternatively or preferably subsequent to the stabilization, the yarn can be guided through a setting zone at temperatures up to 245° C. The successive arrangement of a stabilizing zone and a setting zone results in a particularly compact yarn of little instability. Subsequently, the yarn is reciprocated transversely to its direction of advance by a traversing mechanism 11, and wound on a package 12. The package 12 is driven by a friction roll 13 at a constant circumferential speed.
According to the invention, the draw roll 5 is heated. It should be emphasized that the temperature of the draw roll 5 is higher than the temperature of the draw pin 6. When drawing and relaxing polyester and polyethylene terephthalate yarns the temperature of the draw roll 5 is about 200°-245° C. When the draw pin 6 is heated, its temperature ranges from about 80° to 140° C.
In the case of polyamide yarns, i.e., nylon and perlon yarns, a cold drawing is possible in accordance with normal practice. In so proceeding, the yarns are looped about a draw pin, which is not supplied with heat from an external source. The method of the present invention makes it possible to eliminate entirely the heating of the draw pin 6 also in the case of polyester. In so doing, temperatures ranging from 80° to 140° develop automatically in the yarn as a result of the drawing. The use of an unheated draw pin is also possible, in particular when high draw ratios, which are significantly above the yield point of the yarn, are applied by a corresponding adjustment of the circumferential speeds of the feed system 3 on the one hand and draw roll 5 on the other.
In a test, a preoriented yarn of 295 dtex was drawn between the godets 3 and 5. The speed of godet 3 was 205 meters per minute, and that of godet 5 was 400 meters per minute. Godet 5 was heated to 240°. Beforehand, the yield point of the yarn was determined at a drawing of 1.95. A yarn of 159 dtex was produced with a breaking strength of 4.6 cN/dtex, an elongation of 21% and a TESTRITE™ shrinkage of O. A hot air shrinkage was determined at 1.4%. Then, the draw ratio was reduced, and the same test was conducted with the speed of godet 3 having been 216 meters per minute. The result was a 167 dtex yarn with a breaking strength of 2.5 cN/dtex, a breaking elongation of 9.7% and a TESTRITE™ shrinkage of 0.5%
The above results show that an adjustment of the draw ratio permits the yarn properties to be significantly regulated, in particular the breaking strength, breaking elongation and residual shrinkage. The adjustment of the draw ratio and the temperature of the draw roll 5 makes it possible to produce yarns with very different properties, in particular, breaking strength, breaking elongation, residual shrinkage, even with the use of a nonheated draw pin. Consequently, the present invention makes it possible to use one and the same texturing machine without modification for the production of different yarns. In particular, it becomes possible to produce industrial and textile yarns with one and the same machine. Industrial yarns include such yarns as are used for industrial purposes, such as, for example, sewing thread, reinforcement yarns for webs of fabric, plastic sheets, rubber sheets, and tire cord. Textile yarns are in particular those, which serve directly the human use, in particular clothing.
FIG. 2 illustrates a suitable apparatus for a quick measurement of the residual shrinkage. Such an apparatus is commercially available under the trademark TESTRITE™. This instrument is used especially for comparative tests, and allows the percentage (L1-L2: L1×100) to be determined, by which a pretreated yarn shrinks, when it is subjected to a shrinkage treatment on the TESTRITE™ instrument at the same clamping length, at the same heating length, as well as under the same yarn tension.
The yarn is firmly secured at one end 15 and guided over a measuring roll 16 at the other end. Behind the measuring roll 16, the yarn is loaded by a weight 17. The measuring roll is connected with a needle 18, so that a change in the yarn length is indicated on a scale. The yarn is heated by a heater 19 with a yarn slot 20. It results from general testing principles that when a test is run, the treatment time, the clamping length of the yarn between clamp 15 and measuring roll 16, the length of the heater 19, the temperature of the heater 19, and the weight 17 remain constant
To conduct comparative tests, an apparatus as shown in FIG. 3 was used. In these tests, a polyethylene terephthalate yarn was drawn between the draw rolls 3 and 5 to a final denier of 167 dtex and then air textured. In the first instance, the drawing process occurred, as schematically indicated in FIG. 3, between the feed systems 3 and 5 in that the yarn was first guided over a hot pin 6 and then over a hot plate 21. The draw pin was heated to a temperature ranging from 90° to 120° C., and the hot plate had a temperature around 240° C. A yarn was produced with a strength of 4.11 cN/dtex, a breaking elongation of 12% and a TESTRITE™ residual shrinkage of 6% to 7%. In this test, however, the temperature control on the draw pin and the hot plate was very critical and a very careful adjustment of the temperatures was necessary. In comparison therewith, the method of the present invention, i.e. with the use of a heated draw roll in the place of a hot plate 21, permitted without difficulty a hot drawing with a heated draw pin despite the subsequent hot shrinkage treatment, as results from the following comparative test.
For a comparison, the same yarn was air textured in a processing sequence as shown in FIG. 1. This means that in the draw zone the yarn was guided only over the draw pin 6 heated to 140° C., but not over a hot plate. In its place, the godet 5 was heated to a temperature of 240° C. The yarn was looped about the godet so many times that it resulted in a heated yarn length of 1 meter. The yarn was withdrawn from the heated godet by the air texturing nozzle under a tension of 6 cN and then drawn off from the zone of the air texturing nozzle by the feed system 10 at a correspondingly reduced speed and with a tensile force of 5 cN. An air textured yarn was thus produced, which had substantially the same strength values (breaking strength and breaking elongation) as the yarn produced by the conventional process. The TESTRITE™ shrinkage, however, was reduced to less than 1%.
FIG. 4 is a schematic, cross sectional view of one position of a multi-position air texturing machine, which embodies the present invention. The special feature is that the use of the present invention permits a very simple design and construction of the draw zones and, consequently, a low overall height of the machine. The machine is provided with a creel for supply packages 1.1 and 1.2, on which a preoriented yarn is wound, such as polyester, in particular polyethylene terephthalate yarns. The yarns are unwound over yarn guides 2.1 and 2.2 by means of feed systems 3.1 and 3.2, and advance to draw zones 4.1 and 4.2. Each of the draw zones comprises respectively the aforesaid feed systems 3.1 or 3.2 and draw systems 5.1 or 5.2. The speeds of the feed systems 3.1, 3.2 and the draw systems 5.1 and 5.2 can be adjusted differently from each other. Consequently, it is possible to draw yarns at a different draw ratio. Special emphasis should be laid on the arrangement of the draw zones 4.1 and 4.2, which provide for an opposite direction of the yarn path, though, but are aligned one on top of the other. The two yarns advancing from their supply packages, pass between the two draw zones and then move on to their respective feed system 3.1 or 3.2. While the one yarn advances from feed system 3.1 downwardly over a draw pin 6.1 to the draw system 5.1, the other yarn moves from feed system 3.2 upwardly over draw pin 6.2 to draw system 5.2. For the purpose of drawing, each yarn loops about the draw pin 6.1 or 6.2 respectively by 360°. The draw pin 6.1 is cold, i.e., no heating system is provided to heat the draw pin. The draw pin 6.2 has a larger diameter and can be heated. The godet 5.1 is equipped with a heating system and can be heated to suitable temperatures up to 300° C. Suitable godets are disclosed, for example, in U.S. Pat. No. 3,435,171 and U.S. Pat. No. 3,487,187.
The illustrated yarn path has the advantage that the feed systems 3.1 and 3.2 are not in a very low location above the floor, which allows a simple threading of the yarn on these feed systems. However, another advantage is that the yarn leaving the heated godet 5.1 has a large distance to cover to the subsequent air texturing nozzle 7.
The two yarns advancing from the godets 5.1 and 5.2 respectively enter into the texturing nozzle 7, which is located above the draw zone 4.2. Prior to their entry, at least one of the yarns passes through a water nozzle 27, or is moistened in any other appropriate manner, for example, in a water bath. The water nozzle and air texturing nozzle are accommodated in a water box 28, which can be opened for servicing. The two yarns are joined in the air texturing nozzle 7, and an air jet is directed on the two yarns, which has a component in the direction of advance. By the impact of the air jet, the filaments of the two yarns are cooled, blended with each other and deformed to loops, curls, bows and the like. Since the speed of the draw systems 5.1 and 5.2 can be different, it is possible to guide the yarns into the air texturing nozzle at a different overfeed. This allows to produce effect yarns with very different properties.
The composite yarn produced in air texturing nozzle 7 is subjected to a drawing between a feed system 10 and another feed system 21, as is disclosed in U.S. Pat. No. 32,047. A stabilizing zone is arranged substantially horizontally above the operator aisle, since the feed system 10 on the one side and the feed system 21 on the other side of the operator aisle are located at the same height. The speed ratio of the feed systems 21 and 10 determines the ratio at which the composite yarn is drawn in the stabilizing zone 25. Also this drawing occurs within the elastic range and is not intended to lead to a plastic deformation of the yarn. The speed of the feed system 21 can be up to 15% higher than that of feed system 10.
Upon leaving the feed system 21, the composite yarn passes through the heated tube 23 of a heater 22. A feed system 24 withdraws the yarn from the setting zone 26. The heated tube 23 extends substantially vertically below the feed system 21, so that the yarn advances vertically from above to the bottom. The speeds of the feed systems 24 and 21 are so adapted that the withdrawal speed of feed system 24 is preferably somewhat lower, approximately 2% to 10%, than the speed of feed system 21. This allows to provide in the setting zone for another, controlled shrinkage of the yarn limited by the speed difference, if need be. Finally, the yarn is wound on package 12. The takeup system is arranged at a height favorable for the operator on the side of the heater 22, which faces the operator aisle.
The package is driven on its circumference by a friction roll 13 operating at a constant speed. Indicated at 11 is a yarn traversing mechanism. It is likewise possible to adjust the speeds for both the feed systems 21 and 24 and the friction roll 13 independently of each other. This allows different yarn tensions to be established in the stabilizing zone 25 and the setting zone 26. Further details are disclosed in the aforesaid U.S. Patent. It should be noted that the feed systems 10 and 21 can be driven at the same speed. In this case, no stabilization is needed. It is likewise possible to put the heater 22 out of operation. In this case, no heat setting will occur. The combination of stabilization in zone 25 and heat setting in zone 26, however, allows a yarn to be produced which is particularly well suited for further processing, and which also excels in good textile properties.
It should also be noted that the draw system 5.2 can be unheated or heated. If the godet 5.2 is heated, the draw pin 6.2 can likewise be unheated.
The aforesaid layout of the machine permits a low overall height. In particular, the feed systems 10 and 21 are located at such a height that they can be serviced from the floor. This is accomplished in that the draw zones 4.1 and 4.2 are each equipped only with godets and draw pins. It is also a special advantage that the yarn guided over the heated draw roll 5.1 has a long distance to reach the texturing nozzle, which gives it sufficient time to shrink before it is quenched in the texturing nozzle, which brings the shrinkage to a standstill.
The following table represents test results for the production of a textile and an industrial yarn. The measuring points I-IX indicated therein are shown in FIG. 1. The speeds of feed systems 3, 5 and 10 are indicated in percent so as to be in relation to each other. Indicated at measuring point VI of these tests are the yarn properties, residual shrinkage, and elongation before shrinkage or without shrinkage, and likewise at measuring point IX the same values with a shrinkage treatment according to the present invention. It shows that also with the use of a nonheated draw pin it is possible for both a textile and an industrial yarn to adjust to the required properties, although the draw process itself, i.e., without a residual shrinkage treatment, does not yet lead to usable yarn properties.
TABLE______________________________________POY PESMeasuring Textile IndustrialPoint Processing Variable Yarn Yarn______________________________________I Spinning denier 410 dtex 410 dtexI Yield point 180% 180%II Speed v3% 100% 100%III Yarn temperature 80° C. 130° C.IV Residual shrinkage 10% 12% at 177° C.IV Elongation E 18% 8%IV Spinning denier 210 dtex 178 dtexV Speed v5% 195% 230%V Temperature of draw 190° 240° roll T5VI Yarn tension S1 7.0 cN 6.8 cNVII Yarn tension S2 6.0 cN 5.8 cNVII Yarn temperature ≦40° C. ≦40° C.VIII Overfeed (7 + 20)% (7 + 4)%VIII Speed v10 142% 197.8%IX Residual shrinkage S 1.8 2% (at 177° C.)IX Elongation 25% 14%______________________________________
In the drawings and specification, there has been set forth a preferred embodiment of the invention, and although specific terms are employed, they are used in a generic and descriptive sense only and not for purposes of limitation.
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A method and apparatus for producing an air textured yarn is disclosed, and wherein a partially oriented yarn is withdrawn from a supply package, drawn, and then directly advanced into an air texturing nozzle, wherein a jet of unheated air serves to impart loops, curls, bows and the like to the advancing yarn. The drawing godet of the drawing system is heated so as to heat the advancing yarn, and the yarn is then advanced from the heated godet to the air jet nozzle under a relatively low tension so as to permit the heated yarn to shrink and thereby reduce the residual shrinkage. The jet is unheated air in the air jet nozzle also cools the yarn ahnd thus the formation of the loops, etc. occurs only after shrinkage has ceased.
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BACKGROUND OF THE INVENTION
[0001] The present invention relates to a method of measuring skin cholesterol. More particularly, the invention pertains to a method for the direct assay of cholesterol in skin samples removed by tape stripping, with a view to identifying individuals at risk of having atherosclerosis as well as those at risk of developing atherosclerosis and similar diseases associated with and attributable to high cholesterol levels.
[0002] Numerous studies have shown that atherosclerosis and its complications, such as heart attacks and strokes, are major causes of morbidity and mortality in almost all countries of the world.
[0003] Cost effective prevention of atherosclerosis requires the identification of individuals at risk, thereby allowing their medical treatment and change of life style. A desired goal is identifying those individuals belonging to the high-risk group but there are difficulties in selecting optimum methods for discriminating individuals at risk.
[0004] A widely used method for identifying individuals at risk of having atherosclerosis is based on the measurement of total cholesterol levels in venous blood plasma (Consensus Conference on Lowering Blood Cholesterol to Prevent Heart Disease, JAMA, 1985, 253, pg. 2080). Patients are considered to be at high-risk if their cholesterol level is over 240 mg/dL and there have been recent moves to lower this threshold level to lower values.
[0005] However, total cholesterol levels alone do not accurately predict a patient's risk level. A better prediction can be made by analyzing blood plasma lipoproteins; in particular, measurement of low density and high-density lipoprotein (HDL) cholesterol levels is advantageous (Total and High Density Lipoprotein Cholesterol in the Serum and Risk of Mortality, British Medical Journal, 1985, 290, pg. 1239-1243).
[0006] Despite their advantage, use of the above methods requires blood sampling after a period of fasting. Additionally, the sampling is uncomfortable, poses a risk of infection and the required analysis of plasma lipoproteins and cholesterol is complicated and expensive. Moreover, studies have shown that blood plasma analysis may not entirely reflect the process of cholesterol accumulation in the arterial wall and other tissues. In many cases, neither plasma cholesterol levels nor even complete lipid profiles correlate with the severity of atherosclerosis.
[0007] Significant levels of cholesterol occur in tissue as well as in plasma and it has been shown that tissue cholesterol plays a leading role in development of atherosclerosis. Tissues, including skin, have been identified which accumulate cholesterol in the same way as the arterial wall and studies have demonstrated a close correlation between cholesterol content in the arterial wall and the skin. For example, cholesterol was extracted from lyophilized skin samples and measured using traditional chemical and biochemical techniques. (Nikitin Y. P., Gordienko I. A., Dolgov A. V., Filimonova T. A. “Cholesterol content in the skin and its correlation with lipid quotient in the serum in normals and in patients with ischemic cardiac disease”, Cardiology, 1987, II, No. 10, P. 48-51). While useful, this method is too complicated and painful to be employed for large scale population screening.
[0008] U.S. Pat. No. 4,458,686 describes a method of quantifying various compounds in the blood directly under the skin or on its surface. The method is based on measuring oxygen concentration changes electrochemically, for instance, via polarography. In the case of non-volatile substances that do not diffuse through the skin, it is necessary to implant enzymes under the skin to effect oxygen changes at the skin surface. This patent also discloses the potential of using such methods to quantify the amount of cholesterol using cholesterol oxidase. The complex instrumentation and procedures needed require the services of highly skilled personnel for making measurements, thus limiting the usefulness of the method for screening large numbers of people.
[0009] Determination of the cholesterol content in skin gives a measure of the extent of atherosclerosis and can be obtained through standard laboratory analysis of skin biopsy specimens. However, there is considerable pain involved in taking a skin sample and a risk of infection at the sampling site. In addition, this method has other disadvantages because the thick skin specimens incorporate several skin layers, including the outermost horny layer (stratum corneum), epidermis and dermis. Since the dermal layer is highly vascularized, skin biopsy samples contain blood vessels and blood elements. They may also contain sweat and sebaceous glands and the secretions contained therein. Additionally, subcutaneous fat is located directly under the derma and may also contaminate specimens. Therefore, skin biopsy specimens are heterogeneous and their analysis may give false data on cholesterol content in the skin.
[0010] U.S. Pat. No. 5,489,510 describes a non-invasive method for the visual identification of cholesterol on skin using a reagent having a specific cholesterol binding component in combination with a reagent having an indicator component to provide a visual color change corresponding to the presence of the component bound to cholesterol of the skin. The method overcomes many of the objections of earlier procedures and meets many of the desired goals required for a simple mass screening to identify individuals at risk of having atherosclerosis. The procedure is done directly on the palmar skin and, while it is quick and simple, it requires all individuals to be tested to be present at a doctor's office or clinic where the test is conducted. This of course limits effective large scale screening.
[0011] Molar ratios of the lipids, including cholesterol, in stratum corneum have been determined on samples obtained by direct, solvent extraction of skin (Norlen L., et al. J. Invest. Dermatology 72-77, 112, 1999). High performance liquid chromatography (HPLC) and gas liquid chromatography in conjunction with mass spectrometry were used to separate and analyze the lipids. The analytical methods are complex, but more importantly, the use of corrosive and irritant organic solvent systems to extract human skin for routine determinations is not practical.
[0012] The lipid profile of the stratum corneum layer of skin has been determined using a tape stripping method as described by A. Weerheim and M. Ponec (Arch. Dermatol. Res., 191-199, 293, 2001). In this study, lipids, including cholesterol, were solvent extracted from stratum corneum after tape stripping of skin. The resultant lipid extract was separated by high performance thin-layer chromatography. This method is very laborious. It requires three consecutive solvent systems to effect the separation of the lipids, a staining and charring method to visualize the components and a densitometry step to determine the relative amounts of the lipids. The method does not lend itself to the simple and rapid determination of cholesterol levels in large numbers of samples.
SUMMARY OF THE INVENTION
[0013] It is therefore an object of the present invention to overcome the above drawbacks and to provide a simple and non-invasive method of measuring skin cholesterol, which allows for effective large scale screening.
[0014] According to a first aspect of the invention, there is provided a method of measuring skin cholesterol, which comprises the steps of:
a) providing a tape comprising a backing member coated on at least one side thereof with a medical adhesive; b) applying the tape onto a selected area of skin to adhere the tape to the selected skin area; c) stripping the tape off the selected skin area to obtain a sample representative of an outer stratum corneum layer of the skin, the sample adhering to the tape so as to have exposed skin constituents; d) providing a source of an affinity-enzymatic compound of formula A-C-B, wherein A is a detecting agent having affinity for cholesterol, B is an enzymatic visualizing agent and C is a binding agent linking the detecting agent and the visualizing agent to one another; e) applying a predetermined amount of the affinity-enzymatic compound onto a predetermined surface area of the sample and allowing the compound to remain in contact therewith for a period of time sufficient to cause binding of the detecting agent to cholesterol present in the exposed skin constituents; and f) applying a predetermined amount of a color developing agent onto the predetermined surface area of the sample, whereby the color developing agent reacts with the enzymatic visualizing agent to form a colored product having a color indicative of cholesterol level.
[0021] According to a second aspect of the invention, there is provided a method of measuring skin cholesterol, which comprises the steps of:
a) providing a tape comprising a backing member coated on at least one side thereof with a medical adhesive; b) applying the tape onto a selected area of skin to adhere the tape to the selected skin area; c) stripping the tape off the selected skin area to obtain a sample representative of an outer stratum corneum layer of the skin, the sample adhering to the tape so as to have exposed skin constituents; d) providing a source of an affinity signal-generating compound of formula A-C-B′, wherein A is a detecting agent having affinity for cholesterol, B′ is a signal-generating indicator agent and C is binding agent linking the detecting agent and the indicator agent to one another; e) applying a predetermined amount of the affinity signal-generating compound onto a predetermined surface area of the sample and allowing the compound to remain in contact therewith for a period of time sufficient to cause binding of the detecting agent to cholesterol present in the exposed skin constituents; and f) measuring the signal generated by the indicator agent to provide a value indicative of cholesterol level.
[0028] According to a third aspect of the invention, there is provided a method of measuring skin cholesterol, which comprises the steps of:
a) providing a tape comprising a backing member coated on at least one side thereof with a medical adhesive; b) applying the tape onto a selected area of skin to adhere the tape to the selected skin area; c) stripping the tape off the selected skin area to obtain a sample representative of an outer stratum corneum layer of the skin, the sample adhering to the tape so as to have exposed skin constituents; d) providing a source of cholesterol oxidase as a detecting agent having affinity for cholesterol; e) applying a predetermined amount of cholesterol oxidase onto a predetermined surface area of the sample and allowing the cholesterol oxidase to remain in contact therewith for a period of time sufficient to cause oxidation of cholesterol and formation of hydrogen peroxide; and f) measuring the amount of hydrogen peroxide formed in step (e), the amount of hydrogen peroxide measured being indicative of cholesterol level.
[0035] The present invention also provides, in a fourth aspect thereof, a kit for use in carrying out a method according to the first aspect. The kit comprises:
the aforesaid tape; the aforesaid source of affinity-enzymatic compound of formula A-C-B, wherein A, B and C are as defined above; and a source of the aforesaid color developing agent.
[0039] The invention further provides, in a fifth aspect thereof, a kit for use in carrying out a method according to the second aspect. The kit comprises:
the aforesaid tape; and the aforesaid source of affinity signal-generating compound of formula A-C-B′, wherein A, B′ and C are as defined above.
[0042] The invention additionally provides, in a sixth aspect thereof, a kit for use in carrying out a method according to the third aspect. The kit comprises:
the aforesaid tape; and the aforesaid source of cholesterol oxidase.
[0045] Applicant has found quite surprisingly that the measurement of skin cholesterol can be carried out directly on the skin sample adhering to the aforementioned tape. The procurement of skin samples removed by tape stripping from donor individuals allows assays to be conducted at distant and centralized sites and also allows assays from many individuals to be run concurrently. Thus, the method according to the invention is suitable for large scale screening of individuals for assessing their risk of cardiovascular disease.
DETAILED DESCRIPTION OF THE INVENTION
[0046] Use is preferably made of a tape comprising a backing member formed of polyester. The tape is coated on at least one side thereof with a medical adhesive. The term “medical adhesive” as used herein refers to an adhesive which is hypoallergic and safe for application to the skin. Such an adhesive is preferably a pressure-sensitive adhesive, for example, an adhesive comprising an elastomer formed of block polymers of styrene-isoprene-styrene or styrene-butadiene-styrene.
[0047] A particularly preferred tape for use in the method of the invention is a double-coated pressure-sensitive medical grade tape sold by 3M under Product #9877, or by Adhesive Research, Inc. under Product #8570.
[0048] Double-coated pressure-sensitive tapes are generally available with an easily removable protective liner. The liner protects the tape from adhering until it is removed and keeps the adhesive from becoming contaminated. Liners may be placed on either side of the double-coated tape or the tape may have a single liner and be wound onto itself, thereby protecting both surfaces.
[0049] Liners with differential release properties may be used so that a first side of adhesive may be exposed while protecting the second adhesive surface. A double-coated tape with differential liners is particularly advantageous for skin sampling. Removal of the first liner allows the tape to be stuck onto the backing support of a sampling device and leaves the skin-sampling side covered with the second liner. This second liner protects the skin sampling adhesive area from sticking and from contamination until it is to be used. When required for skin sampling, the second liner is removed.
[0050] The tape can be applied onto any part of skin, but the most suitable part is the surface of a palm because the palm does not have sebaceous glands whose secretions contain cholesterol which may affect diagnostic results. Additionally, the skin on the palm is readily accessible for sampling.
[0051] It is desirable to obtain uniform amounts of skin samples for analysis. Application of the adhesive tape for sampling is typically and routinely done using a single application of the tape to the skin. Additional amounts of stratum corneum material can be obtained by additional applications of the tape to the skin. Each subsequent application of the tape to the skin results in additional skin adhering to the tape. This process continues until the tape becomes saturated with skin material after which it is no longer sticky. The number of applications required to saturate a tape depends on the type of adhesive used, but for most commonly used adhesive tapes, saturation is achieved with less than ten applications. Applying tape to a fresh area of skin for each subsequent stripping results in better and faster saturation of the tape. Therefore, for consistent and good sampling, it is convenient to make ten applications of a tape to the skin, using new areas of skin for each application.
[0052] After skin sampling, the sampling device is closed and shipped to a central laboratory for assay of cholesterol.
[0053] When using a compound of formula A-C-B or A-C-B′ for the analysis of cholesterol in the skin samples, the detecting agent A can be for example a steroid glycoside, a triterpene glycoside, a hydrophobic protein, a polyene antibiotic or an anti-cholesterol antibody. Use is preferably made of a steroid glycoside, such as digitonin. The binding agent C, on the other hand, is preferably a copolymer of maleic anhydride and N-vinylpyrrolidone.
[0054] In the case where use is made of a compound of formula A-C-B, the enzymatic visualizing agent B is preferably an enzyme selected from the group consisting of peroxidase, alkaline phosphatase, urease, galactosidase, glucose oxidase and acetylcholinesterase. Peroxidase such as horseradish peroxidase is preferred. In this particular case, after step (e), the peroxidase is activated with hydrogen peroxide to form an activated peroxidase, and the color developing agent used in step (f) reacts with the activated peroxidase to form the aforesaid colored product. To this end, a predetermined amount of an aqueous solution containing hydrogen peroxide and the color developing agent is applied in step (f) onto the predetermined surface area of the sample. Examples of suitable color developing agents which can be used in step (f) include 2,2′-azino-di-(3-ethylbenzthiazoline-6-sulfonic acid) and 3,3′,5,5′-tetramethyl benzidine. 3,3′5,5′-Tetramethyl benzidine is preferred.
[0055] In the case where use is made of a compound of formula A-C-B′, the indicator agent B′ can be for example a dye, a fluorophore, a radioisotope, a metal sol compound or a chemiluminescent compound. When the indicator agent is a dye, step (f) can be carried out by spectrophotometry, such as colorimetry. When the indicator agent is a fluorophore, step (f) can be carried out by fluorometry. When the indicator agent is a radioisotope, step (f) can be carried out by means of a radioactivity sensor. When the indicator agent is a metal-sol compound, step (f) can be carried out by colorimetry. When the indicator agent is a chemiluminescent compound, step (f) can be carried out by luminometry.
[0056] In the case where use is made of cholesterol oxidase as a detecting agent having affinity for cholesterol, step (f) is preferably carried out by means of an electrochemical sensor, for instance, amperometrically using an electrode. Step (f) can also be carried out by spectrophotometry after addition of peroxidase and a colorimetric indicator. The peroxidase used is preferably horseradish peroxidase. Examples of suitable colorimetric indicators which can be used include 2,2′-azino-di-(3-ethylbenzthiazoline-6-sulfonic acid) and 3,3′,5,5′-tetramethyl benzidine. A colorimetric indicator consisting of a multicomponent oxidative coupling reagent of Trinder or Ngo-Lenhoff type can also be used. When use is made of peroxidase and a colorimetric indicator, the aforementioned kit for carrying out the method according to the third aspect of the invention further comprises a source of peroxidase and a source of the colorimetric indicator.
[0057] The method according to the invention enables to achieve a simple, high-throughput skin cholesterol assay.
BRIEF DESCRIPTION OF THE DRAWINGS
[0058] The following non-limiting examples illustrate the invention, reference being made to the accompanying drawings, in which:
[0059] FIG. 1 is a top view of a sampling device as used in Example 2; and
[0060] FIG. 2 is a fragmentary view of the sampling device illustrated in FIG. 1 , showing details of the sampling member thereof.
EXAMPLE 1
[0061] A double-coated pressure-sensitive medical grade tape having a protective release liner on an upper sampling side and sold by Adhesive Research, Inc. was used. A piece of tape 1 inch by 1 inch was cut. The piece of tape was stuck, using the exposed, lower adhesive surface to one end of a 1 inch by 3 inch thin plastic (white polystyrene) member, leaving a 1 inch by 2 inch piece of uncovered plastic as a handle for applying the tape to the skin and for labeling the sample.
[0062] To obtain a skin sample, the protective liner was removed and the exposed adhesive area applied to a clean dry section of skin. Pressure was applied to the back of the plastic member over the adhesive area to effect good contact of the adhesive with the skin. The plastic member with the attached tape and stratum corneum sample was then peeled from the skin.
[0063] The sample was cut into four equal pieces each measuring ½ inch by ½ inch. One piece was placed in a well of a 12 well tissue culture plate, or similar container, with the skin sampling side facing up. An aliquot of reagent of the type A-C-B was then applied onto a predetermined surface area of the skin sample. The A-C-B reagent used was a conjugate of digitonin (A) linked to horseradish peroxidase (B) through a maleic anhydride-N-vinylpyrrolidone copolymer (C). The reagent was left in contact with the skin sample for 15 minutes at room temperature, after which it is removed by aspiration. Thereafter, the sample was washed with three separate aliquots of a wash solution to remove non-specifically bound reagent. The piece was then placed in a new, clean well of a 12 well tissue culture plate, or similar container, with the skin sampling side facing up. An aliquot of substrate solution was applied to the sample and left in contact with the skin sample for 15 minutes at room temperature. The substrate solution used was Enhanced K-Blue reagent available from Neogen Corp.(Lexington, Ky., USA) and containing hydrogen peroxide and tetramethyl benzidine as color developing agent. An aliquot of the developed substrate solution was removed from the well and added to an aliquot of 1 N sulfuric acid in a well of a 96 well microwell plate. The optical density of the resulting solution, which is a measure of the amount of cholesterol in the skin sample, was read at 450 nm on a plate reading spectrophotometer.
EXAMPLE 2
[0064] Use was made of a sampling device as shown in FIG. 1 . The sampling device which is generally designated by reference numeral 10 is formed of plastic (polypropylene) and comprises a sampling member 12 connected to a closure member 14 by an integral hinge 16 . The closure member 14 has a peripheral rim 18 and four pins 20 , adapted to lock into, respectively, a peripheral groove 22 and four holes 24 formed in the sampling member 12 . Folding the hinge 16 causes engagement of the rim 18 with the groove 22 and of the pins 20 with the holes 24 , thereby ensuring that the two halves of the device 10 remain closed and sealed to prevent dust and contamination of the interior surfaces. The outer surface (not shown) of the closure member 14 has a flat area for receiving a label and barcode strip, for sample identification. The sampling member 12 and closure member 14 are respectively provided with finger-tabs 26 and 28 for opening the device 10 .
[0065] A double-coated pressure-sensitive medical grade tape 30 having a protective Kraft paper release liner 32 and sold by 3M under Product #9877 was adhered to the central area of the sampling member 12 . The release liner 32 is wider than the adhesive tape 30 , thereby defining a strip 32 ′ along one edge with no attached tape. This strip 32 ′ of liner overhangs the edge of the device to form a tab for easy removal of the liner. Immediately before use, the liner 32 is removed using the overhanging tab 32 ′ and this exposes the adhesive of the tape 30 for skin sampling.
[0066] The palmar skin area for sampling was cleaned and dried. The tape 30 with the exposed adhesive was applied onto the palm. The tape 30 was pressed against the skin by applying pressure to the back of the sampling member 12 above the adhesive area, thereby causing adherence of the stratum corneum layer. The device 10 was peeled away, reapplied to a new area of the palm and again pressed to the skin. The device is peeled away and applied to the palmar skin in this way for a total of 10 applications.
[0067] Two small dipsticks 4 mm in width were cut from the device 10 as follows. An end portion of the sampling member 12 was removed by cutting along the portion of groove 22 which is adjacent to the tab 26 . Three cuts were then made along guide lines 36 (shown in FIG. 2 ) molded into the sampling member 12 , to delineate the 4 mm sticks, cutting from the edge to just past the centre line. The two 4 mm wide sticks were released from the sampling member 12 by making a third cut across the center of the member 12 , using guide line 38 molded into the member 12 . These sticks had an upper portion devoid of tape and a lower portion with tape having the skin sample adhered thereto.
[0068] The sticks were each placed into 100 uL solution of an A-C-B reagent in wells of a 96 well microwell plate. The reagent was a conjugate of digitonin (A) linked to horseradish peroxidase (B) through a maleic anhydride-N-vinylpyrrolidone copolymer (C) and was used at a concentration of approximately 1 μg/mL. The sticks were left in the solution for 15 minutes at room temperature, after which they were removed and placed into new wells of a microwell plate containing 200 μL of wash solution. The microwell plate was agitated to effect washing and after 1 min the sticks were removed to new wells containing 200 μL of fresh wash solution and again agitated for 1 min. Washing with agitation was done a third time, after which the sticks were removed and placed in 100 uL of a substrate solution (Enhanced K-Blue reagent). The sticks were incubated with the substrate solution, in the dark, for 15 minutes at room temperature, and then removed. One hundred (100) μL of 1 N sulfuric acid were added to the wells with the substrate solution to stop further reaction and the optical density of the resulting solution was read at 450 nm on a plate reading spectrophotometer, to provide a measure of the amount of cholesterol in the skin sample.
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Skin cholesterol is measured by applying an adhesive tape onto a selected area of the skin to adhere the tape to the selected skin area and stripping the tape off the selected skin area to obtain a sample representative of the outer stratum corneum layer of the skin, the sample adhering to the tape so as to have exposed skin constituents. The sample is assayed using a detector reagent that specifically binds to cholesterol and in addition has an indicator component that allows quantitation of the amount of cholesterol present in the exposed skin constituents.
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FIELD OF THE INVENTION
The present invention relates generally to radiation sensors and more particularly to such a radiation sensor having a radiation sensing medium crystal mounted in a housing having integral collimating means which directs the radiation onto the sensing medium.
BACKGROUND OF THE INVENTION
Radiation sensors are well known in the art. One such radiation sensor is a Geiger counter which senses the emission of radiation from a radiating source and emits signals indicative of the number of charged particles impinging on a radiation sensitive crystal carried in the housing of the Geiger counter apparatus. Radiation sensors come in many different forms and are usable in many different environments.
In coal mining, for example, radiation sensors are used to detect radiation emissions from layers of shale and other materials carried in the ground. Typically, a coal mine is found to contain alternating layers of coal and shale (and other materials mixed in the shale). Radiation is generally emitted from the shale layer and through the inert coal layer. By sensing (counting) the number of charged particles striking a radiation sensor (crystal), the thickness of the coal layer can be deductively substantially determined.
In a coal mining operation, a mining machine is moved within a coal seam, and coal is extracted from the seam. The coal mining machine generally includes coal extraction apparatus which is movable in elevation while the coal mining machine is movable within the coal seam of the tunnel. Thus, the cuts must be such that while successively removing coal from the vertical surface of the coal seam, a predetermined thickness of coal is often desired to be left on the roof of the tunnel so as to prevent roof material (shale, etc.) from crashing down from above. If too much coal (roof coal) is left on the roof, much valuable and expensive coal is left in the mine, resulting in a very expensive mining operation; and, if too little roof coal is left, the layer of roof material can deteriorate, crumble, and fall, creating unsafe conditions.
In the past, one method of determining the thickness of the roof coal was to temporarily terminate the coal cutting operation and move the machine so that a drill may be used to bore through the coal layer until the coal layer was penetrated and the roof material layer contacted by the tip of the drill bit. Such procedure was time consuming and costly. Therefore, various arrangements of radiation sensing elements were resorted to in an effort to eliminate such time consuming and costly drilling procedures.
SUMMARY OF THE INVENTION
It is an object of the present invention, therefore, to provide a radiation sensor for detecting emissions of radiation from a source of radiation.
It is another object of the present invention to provide such a radiation sensor with a protective housing which shields a radiation sensitive medium, such as a crystal, carried in the housing.
It is yet another object of the present invention to provide the housing with integral collimating means so that charged particles are concentrated on the sensitive portion of the radiation sensitive crystal.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is an elevational view of a longwall shearer in operational position in a coal mine. The radiation sensing device of the present invention is shown mounted on the longwall shearing machine.
FIG. 2 is a pictorial view of the radiation sensor device of the present invention.
FIG. 3 is a longitudinal sectional view taken along line 3--3 of the device of FIG. 2.
FIG. 4 is a cross-sectional view taken along line 4--4 of FIG. 2.
FIG. 5 is a longitudinal cross-sectional view of another embodiment of the present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENT
As seen in FIG. 1, a longwall shearing machine 10 is shown to include a body 12 having a ranging arm 14 pivotally secured thereto and a cutter drum 16 mounted on the end of the ranging arm. Such machines are known in the art, and one such machine is disclosed in U.S. Pat. No. 4,154,084.
The structure of the coal interface is shown in FIG. 1 to include layers of materials 18, such as shale, etc., and coal 20. The materials 18 typically emit radiation which passes through the inert coal. The machine is movable along the vertical face 22 of the wall and provides successive cuts into the vertical wall while leaving a predetermined amount (thickness) 24 of coal at the roof 26 of the tunnel (roof coal) for reasons explained, supra.
To determine the thickness of the roof coal during the mining operation, a radiation sensor assembly 28 is mounted (supported) on the machine 10 to receive and indicate the amount of charged particles striking the radiation sensitive crystal of the sensor assembly. As the thickness of the roof coal decreases, the amount of signals emitted by the sensor increases since more radiation is passed through thinner roof coal.
The radiation sensing device 28 is shown in the figures to include a rectangular housing 29 enclosing a crystal 30 (FIG. 2). The housing is shown to have two adjoining sections 31 and 33, a bottom wall 32, end walls 34 and 36, side walls 38 and 40, and a cover 42. A lead liner 44 is mounted to one end wall 34, the side walls 38 and 40, and a rear portion 46 of the bottom wall 32. The second portion 48 of bottom wall 32 and the end wall 36 need not be lined with lead since the electronics (and not the crystal) is mounted in this section of the housing.
Retaining cover 42 is provided with a series of elongated spaced openings 50 in a portion 52 thereof. A portion 54 of the cover does not contain these openings since the electronics and not the crystal is mounted in the section of the housing which is enclosed by cover portion 54. The electronics is indicated (in FIG. 3) by the numeral 56. The electronics includes electronic circuits which contain components that change the output from the crystal to electrical impulses which are directed to a photomultiplier tube 57 whose output is indicative of the received radiation. Such electronic circuitry and crystals are well known in the art.
The elongated openings 50 (FIGS. 3 and 4) are positioned in spaced side-by-side relation in cover 42, and a series of baffles 52 are provided in the cover and include a projecting portion 53 which 52 depends from the lower surface 56 of cover 42. A single baffle is positioned between adjacent openings 50 and is provided with a thickness X. This dimension X is determined by the desired "look" angle θ (FIGS. 5 and 6). It should be obvious that as the dimension X varies, so does the angle θ.
A protective shield 58 is provided on the top surface of cover 42 to prevent debris from entering the housing 29. Shield 58 is made of a material (such as Plexiglass™, etc.) which permits the radiation to pass onto the crystal.
FIG. 5 is an elevational view of another embodiment of the present invention wherein like numbers refer to like parts. As seen in FIG. 5, the lower portion of housing 29 (side walls, end walls, and bottom) is similar to that illustrated in FIG. 3 and discussed supra. A different cover 60, however, is used in this embodiment. The cover 60 is provided with baffles 62 which are built into the cover and contained between the upper and lower surfaces 64 and 66, respectively, of the cover. The baffles are spaced a predetermined distance apart to define the angle θ at which radiation is directed into the housing and onto the sensitive portion of the crystal.
A second protective shield 68 of radiation-pervious material is shown (FIG. 5) to be positioned between the lower surface 66 and the upper portion of housing 29 to serve as a vent for any internal explosions, as is well known in the art. The dimension (thickness) X is chosen so as to produce the desired angle θ as discussed in conjunction with the embodiment illustrated in FIG. 3.
It is to be understood that while the sensor assembly of the present invention has been discussed in conjunction with a "mining machine," such a mining machine may be longwall or continuous types or any of other types of "mining" machines.
It is to be further understood that the sensor assembly of the present invention measures a substantial thickness of coal where adequate gamma radiation exists in seam boundary coal. Furthermore, the sensor assembly is very rugged, is provided with a moisture-sealed construction, and is easily installed on existing or new mining machines.
It should be noted that the covers for the lower enclosure may, if desired, have a lead lining on the bottom surfaces thereof; however, as shown in the drawings, the covers are made of heavy metal and are thick enough to prevent radiation from passing therethrough.
It is to be yet further understood that the present invention is not limited to the precise embodiments as disclosed herein and that other modifications can be made by one of ordinary skill in the art without departing from the spirit and scope of the invention as defined by the appended claims.
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A radiation-sensing assembly adapted for sensing radiation emitted from a source of radiation which may be non-coal layers (shale and other materials) in a coal mine tunnel. The sensor assembly incudes a housing forming an enclosure for a radiation-sensing medium. A cover is provided on the top of the lower portion of the housing, and radiation passes through the cover to impinge on the sensing machine. The cover includes a collimator, which is built into the cover, to direct the radiation from the source to the sensing medium.
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BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to a method for fabricating a fiber array module and, more particularly, to an efficient method for fabricating a fiber array module, which is practical for making fiber array modules rapidly.
[0003] 2. Description of Related Art
[0004] In recent years, optical fibers are intensively used as signal transmission media in optical communication. By matching with the development of high-channel-counts-plane-wave-guides and that of dense-wavelength-DeMux/Mutiplexer-DWDM, the communication through optical fibers can meet the demand for transmitting high-volume-data in high speed in internet communication and broadband communication. In most cases, plane-wave-guides of high channel counts containing at least a fiber array are commonly used or sandwiched between related photoelectric components for transmitting signals between those photoelectric components. A conventional fiber array module generally comprises a fiber array substrate having a plurality of V-grooves for receiving and holding optical fibers and keeping loaded optical fibers in accurate aligned positions. Due to thin thickness, it is difficult to mount and to align optical fibers into the V-grooves of the fiber array substrate. Although various measures are developed and adapted for aligning and mounting optical fibers on the V-grooves of a fiber array substrate, the most commonly employed measure is to load the optical fibers on the V-grooves manually. However, this manual loading method is inaccurate, time-consuming and expensive because more employers and much time are required to load optical fibers in the V-grooves of a fiber array substrate.
[0005] Therefore, it is desirable to provide a fiber array module fabrication method and apparatus that eliminates the aforesaid drawback.
SUMMARY OF THE INVENTION
[0006] It is the main object of the present invention to provide a method for fabricating a fiber array module to simplify the assembling steps, to locating or positioning the optical fibers on said base block accurately, repeatedly and efficiently, and to save the time for assembling.
[0007] It is another object of the present invention to provide a fiber array module fabrication apparatus, which enables simplify the assembling steps, to locating or positioning the optical fibers on said base block accurately, repeatedly and efficiently, and to save the time for assembling optical fiber array substrate
[0008] To achieve these and other objects of the present invention, the method for fabricating a fiber array module comprises the steps of: providing at least one optical fiber ribbon, at least one fiber array substrate having a plurality of fixing grooves, and a device having at least two holder bases with at least one locating groove and aligning grooves, wherein at least one longitudinally extended fixing groove of said fiber array substrate is coated with solders or binders for locating said optical fibers, said locating groove of said holder bases is functioned for locating said optical fiber ribbon, and said aligning grooves is functioned for aligning said optical fibers extended from said ribbon; putting at least one fiber ribbon in said locating groove of said two holder bases, putting said at least one fiber array substrate in between said holder bases, keeping optical fibers of said optical fiber ribbon in the aligning grooves of said holder bases and the fixing grooves of said fiber array substrate; curing said binders or melting said solders through radiation or heat to fasten said optical fibers on said fiber array substrate; and cutting off said optical fibers from said fiber array substrate and then removing fiber array substrate with the secured optical fibers from said two holder bases.
[0009] According to one embodiment of the present invention, the apparatus for fabricating a fiber array module by combining at least one optical fiber ribbon, a fiber array substrate, and a fiber array cover plate, wherein the surface of said optical fibers of said optical fiber ribbon or the surface of said fiber array substrate is coated with a layer of binders or solders, comprises: at least two holder bases having locating grooves and a plurality of longitudinally extended locating grooves, wherein said locating grooves are adapted for holding said optical fiber ribbon and for sandwiching said fiber array substrate therebetween, said locating grooves are adapted for aligning said optical fibers extended from said optical fiber ribbon with respective grooves of said fiber array substrate; and a heater or a light adapted to cure said binders or to melt said solders to fix said optical fibers of said optical fiber ribbon to said fiber array substrate and said fiber array cover plate.
[0010] According to another embodiment of the present invention, the apparatus for fabricating a fiber array module by combining at least one optical fiber ribbon, a fiber array substrate, and a fiber array cover plate, wherein the surface of said optical fibers of said optical fiber ribbon or the surface of said fiber array substrate is coated with a layer of binders or solders, comprises: at least two holder bases having locating grooves and a plurality of longitudinally extended aligning grooves, wherein said locating grooves are adapted for holding said optical fiber ribbon and for sandwiching said fiber array substrate therebetween, said aligning grooves are adapted for aligning said optical fibers extended from said optical fiber ribbon with respective fixing grooves of said fiber array substrate; and a heater or a light adapted for curing said binders or to melting said solders to fix or to fasten said optical fibers of said optical fiber ribbon to said fiber array substrate and said fiber array cover plate.
[0011] Other objects, advantages, and novel features of the invention will become more apparent from the following detailed description when taken in conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0012] [0012]FIG. 1 is a schematic drawing showing a fiber array module fabrication apparatus according to the first embodiment of the present invention.
[0013] [0013]FIG. 2 is a schematic drawing showing a fiber array module fabrication apparatus according to the second embodiment of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0014] The fiber array cover plate to be used for making a fiber array module may be variously embodied. Preferably, the fiber array cover plates are plates having grooves corresponding to the grooves of the fiber array substrate. During step (B) of the fiber array module fabrication method, the fiber array substrate is put in between the two holder bases, keeping the grooves of the fiber array substrate respectively aimed at or connected to the locating grooves of one holder base, and then the optical fibers of the optical fiber ribbon are respectively arranged in the grooves of the fiber array substrate and the locating grooves of the holder base. Preferably, the optical fibers are peripherally coated with a layer of solder or binder. When solder is used, it is preferred to be Sn/Au or Sn/Pb. The selected solder can be coated on the surface of the optical fibers, the fiber array substrate and the corresponding fiber array cover plate. The solder is coated on the optical fibers after stripping of the polymer layer of the optical fibers.
[0015] With reference to FIG. 1, a fiber array module fabrication apparatus 100 in accordance with the first embodiment of the present invention is shown comprising a first holder base 110 having a locating groove, a second holder base 112 having multiple aligning grooves, and a heat source 130 . The holder bases 110 and 112 are adapted to hold a fiber array substrate 300 , for enabling optical fibers 400 to be put in or aimed at grooves in the fiber array substrate 300 . A pivoted cover 114 is respectively provided at the topside of the first holder base 110 and the topside of the second holder base 112 . After positioning of a optical fiber ribbon 420 in the locating groove of the first holder base 110 and arranging of the optical fibers 400 of the optical fiber ribbon 420 in the aligning grooves of the second holder base 112 , the pivoted covers 114 are closed on the holder bases 110 and 112 to hold the optical fiber ribbon 420 in the fiber array substrate 300 . A space is defined between the holder bases 110 and 112 for receiving the fiber array substrate 300 . The heat source 130 provides heat or radiation to melt the applied solders or polymerize the applied binders on the surface of the optical fibers or the surface of the fiber array substrate, thereby causing applied solders or binders to fixedly secure the optical fibers 400 to the fiber array substrate 300 and the corresponding fiber array cover plate. A cutter assembly 132 is pivoted to the second holder base 112 in the space between the holder bases 110 and 112 , and adapted to cut off optical fibers 400 at the ends of the grooves of the fiber array substrate 300 adjacent the second holder base 112 , separating the optical fibers 400 at the fiber array substrate 300 from the second holder base 112 . According to this embodiment, the grooves in the second holder base 112 are preferably V-grooves arranged in parallel.
[0016] The fiber array module fabrication method using the fiber array module fabrication apparatus 100 according to the first embodiment of the present invention is outlined hereinafter. At first, the prepared fiber array substrate 300 is put between the holder bases 110 and 112 , keeping the fixing grooves of the fiber array substrate 300 in alignment with the aligning grooves of the second holder base 112 , and then optical fibers 400 are arranged in the aligning grooves of the second holder base 112 and the fixing grooves of the fiber array substrate 300 . Before installation of the optical fibers 400 , the surface of the fiber array substrate 300 (including the fixing grooves of the fiber array substrate 300 ) is coated with a layer of solders or binders. Preferably, the optical fibers 400 are peripherally coated with a layer of solders or binders. After alignment of the fixing grooves of the fiber array substrate 300 with the aligning grooves of the second holder base 112 , the prepared optical fibers 400 are put in the fixing grooves of the fiber array substrate 300 and the aligning grooves of the second holder base 112 . Because the fixing grooves of the fiber array substrate 300 are respectively aligned with the aligning grooves of the second holder base 112 , the optical fibers 400 can be easily and accurately positioned in the grooves of the fiber array substrate 300 . After positioning of the optical fibers 400 in the grooves of the fiber array substrate 300 and the aligning grooves of the second holder base 112 , the fiber array cover plate 410 is closed on the fiber array substrate 300 over the optical fibers 400 in the fiber array substrate 300 , and the pivoted covers 114 are closed to hold down the optical fiber ribbon 420 in the aligning groove of the first holder base 110 and the optical fibers 400 of the optical fiber ribbon 420 in the aligning grooves of the second holder base 112 , and then the heat source 130 is started to heat or radiate the optical fibers 400 , thereby causing the solder or binder to fixedly secure the optical fibers 400 to the fiber array substrate 300 and the fiber array cover plate 410 . At final, the cutter assembly 132 is operated to cut off the optical fibers along the vertical inner sidewall of the second holder base 112 , and then the assembly of the fiber array substrate 300 , the optical fiber ribbon 420 and the fiber array cover plate 410 , i.e., the finished fiber array module is removed from the fiber array module fabrication apparatus 100 .
[0017] [0017]FIG. 2 shows a fiber array module fabrication apparatus according to the second embodiment of the present invention. According to this embodiment, the fiber array module fabrication apparatus 200 comprises two first holder bases 610 each having a longitudinally extended locating groove, a second holder base 612 having a plurality of longitudinally extended aligning grooves, the second holder base 612 being spaced between the first holder bases 610 , two cutter assemblies 632 respectively pivoted to two opposite vertical lateral sides of the second holder base 612 , and two heat sources 630 respectively arranged between the first holder bases 610 and the second holder base 612 .
[0018] The holder bases 610 and 612 are adapted to hold two fiber array substrates 700 , keeping the fixing grooves of the fiber array substrates 700 respectively aimed at or connected to the aligning grooves of the second holder base 612 , so that optical fibers 400 of optical fiber ribbon s 820 can easily and accurately be put in the fixing grooves of the fiber array substrates 700 . Two covers 614 are respectively pivoted to the first holder bases 610 and adapted to hold down the optical fiber ribbon s 820 . After positioning of optical fiber ribbons 820 in the locating grooves of the first holder bases 610 and arranging of the optical fibers 800 of the optical fiber ribbons 820 in the aligning grooves of the second holder base 612 , the pivoted covers 614 are closed on the first holder bases 610 to hold down the optical fiber ribbons 820 in the fiber array substrates 700 . Two spaces are respectively defined between the first holder bases 610 and the second holder base 612 for receiving the fiber array substrates 700 . The heat sources 130 provide heat or radiation to melt applied solder or polymerize applied binder, thereby causing applied solder or binders to fixedly secure the optical fibers 800 to the fiber array substrates 700 and the corresponding fiber array cover plates. The cutter assemblies 632 are respectively pivoted to the second holder base 612 in the spaces between the first holder bases 610 and second holder base 612 , and adapted to cut off optical fibers 700 at the ends of the grooves of the fiber array substrates 700 adjacent the second holder base 612 , separating the optical fibers 700 at the fiber array substrates 700 from the second holder base 612 . According to this embodiment, the grooves in the second holder base 612 are preferably V-grooves arranged in parallel.
[0019] The fiber array module fabrication method using the fiber array module fabrication apparatus 200 according to the second embodiment of the present invention is outlined hereinafter. At first, the prepared two fiber array substrates 700 are respectively put in between the first holder bases 610 and the second holder base 612 , keeping the fixing grooves of the fiber array substrates 700 in alignment with the aligning grooves of the second holder base 612 , and then optical fibers 400 are arranged in the locating grooves of the second holder base 612 and the grooves of the fiber array substrates 700 . Before installation of the optical fibers 700 , the surface of each fiber array substrate 700 (including the grooves of each fiber array substrate 700 ) is respectively coated with a layer of solders or binders. Preferably, the optical fibers 700 are peripherally coated with a layer of solders or binders. After alignment of the grooves of the fiber array substrates 700 with the aligning grooves of the second holder base 612 , the prepared optical fibers 800 are put in the fixing grooves of the fiber array substrates 700 and the aligning grooves of the second holder base 612 . Because the fixing grooves of the fiber array substrates 700 are respectively aligned with the aligning grooves of the second holder base 612 , the optical fibers 800 can be easily and accurately positioned in the fixing grooves of the fiber array substrates 700 . After positioning of the optical fibers 800 in the fixing grooves of the fiber array substrates 700 and the aligning grooves of the second holder base 612 , the fiber array cover plates 810 are closed on the fiber array substrates 700 over the optical fibers 800 in the fiber array substrates 700 , and the pivoted covers 614 are closed to hold down the optical fiber ribbons 820 in the locating grooves of the first holder base 610 and the optical fibers 800 of the optical fiber ribbon 820 in the aligning grooves of the second holder base 612 , and then the heat source 630 are started to heat or radiate the optical fibers 800 , thereby causing the solders or binders to fixedly secure the optical fibers 800 to the fiber array substrates 700 and the fiber array cover plates 810 . At final, the cutter assemblies 632 are operated to cut off the optical fibers along the two opposite vertical lateral sidewalls of the second holder base 612 , and then the two assemblies of the respective fiber array substrates 700 , optical fiber ribbon s 820 and fiber array cover plates 810 , i.e., the two finished fiber array modules are removed from the fiber array module fabrication apparatus 200 .
[0020] Although the present invention has been explained in relation to its preferred embodiments, it is to be understood that many other possible modifications and variations can be made without departing from the spirit and scope of the invention as hereinafter claimed.
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A fiber array module fabrication method is disclosed including the steps of: (a) preparing a optical fiber ribbon, a solder/binder coated fiber array substrate, and two holder bases, one holder base having longitudinally extended locating grooves, (b) putting the fiber array substrate in between the holder bases and keeping the longitudinally extended grooves of the fiber array substrate in alignment with the longitudinally extended aligning grooves of the holder base and then loading the optical fiber ribbon in the holder bases and keeping the optical fibers of the fiber ribbon in the locating grooves of the holder base and the fixing grooves of the fiber array substrate, (c) heating the solder or radiating the binder to fixedly secure the optical fibers to the fiber array substrate and the fiber array cover plate, and (d) cutting off the optical fibers and removing the finished fiber array module from the holder bases.
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BACKGROUND OF THE INVENTION
The present invention relates to ring furnaces and more particularly to an improved baffle in the side wall flues thereof for producing improved, for example, carbonaceous anodes for use in producing aluminum metal by electrolysis of alumina dissolved in a molten salt electrolyte.
As explained by J. Z. Nelson at the AIME Annual Meeting, Washington, D.C., Feb. 18, 1969,
A carbon baking ring furnace is made up of a number of pits for the anodes, arranged in rows or "sections" in two halves of a suitable building. The number of pits per section ranges from six to nine, and the number of sections per furnace varies from 60 to 96. Pit size is chosen to suit the anodes to be baked -- pits are about three feet wide, nine to ten feet long, and nine to ten feet deep. Refractory flues make up the side walls of each pit, and refractory headwalls form the ends of the pits. The flues are connected in series. Firing and waste gas equipment is movable, so that four to six fires can move around the furnace in procession.
Anodes are packed in the furnace pits in layers, either upright or on end, with sized coke packing material for support as the anodes soften during baking; and with a top blanket of coke to insulate and seal the pit. The packing coke may contain volatiles -- these and volatiles from the anode binder are burned inside the flues (operating at reduced pressure), contributing to fuel input. Cathode blocks may also be baked in ring furnace pits, and cokes and anthracite coals may be calcined.
From 13 to 18 sections in a series are needed for the operation of one "fire" in a ring furnace. A "fire" is a series of burners, arranged with one to each flue in a section. Considering one such fire in a ring furnace, the sections involved would be:
A. one to three sections will have cooled, and are being unpacked. Pit temperatures will be 200° - 300°C.
B. five to seven sections of baked anodes will be cooling. Combustion air for the fire will be drawn through the flues of some or all of these sections. depending on draft capacity. Pit temperatures will range from 400° to 1150°C. Air to the baking section will be 800° - 1100°C.
C. one section will be baking. During the firing time of 40 to 60 hours, pit center temperatures in that section will be raised from 800° - 900°C. to 1100° - 1200°C.
D. two to four sections of green anodes will be preheated by the waste gas passing through their flues. Pit temperatures thus range from "cold" up to 800° - 900°C.; while the waste gas cools from 1300° - 1400°C. down to 300° - 400°C.
E. one to three sections of green anodes will be waiting their turn at preheating as the fire moves toward them.
F. one to three sections of pits will be empty, for any refractory maintenance and for reloading.
For extensive, detailed illustrations of the design of ring furnaces, reference is made to U.S. Pat. Nos. 1,330,164, 1,330,175, and 1,351,281.
These patents have their individual idiosyncrasies, but they all operate essentially as described by J. Z. Nelson.
With respect to 1,330,164, a peculiarity of that design is that the flame first extends out under a cover and over the pits. The present inventors prefer to completely insulate the tops of the pits and to fire directly into the flues of the pit side walls. Also, it is the preferred practice of the present inventors not to run the air or combustion gases underneath the pits, but rather to let them pass directly from side wall flue to side wall flue.
In 1,330,175, it will be seen that the art had already begun to abandon the technique of initially firing underneath a cover and over the pits. Thus, in 1,330,175, firing is directly into the flues in the pit side walls. However, here, too, there is a difference between what was done earlier and the presently preferred practice of the inventors, in that the firing is effected with the flame direction horizontal into the upper part of the flues. In contrast, presently preferred practice is to direct the fuel downwardly into the flue being fired.
In 1,351,281, we have an example of the art's using the downwardly directed introduction of the fuel into the flue in the manner preferred by the inventors.
In the TMS PAPER SELECTION Paper No. A69-26, of the Metallurgical Society of AIME, entitled "Operation of Ring Type Anode Baking Furnaces - Methods of Improving Baked Anode Quality" by R. C. Abrahamson, W. F. Barrier, and A. O. Pinner, which was presented at the TMS-AIME Annual Meeting, February 17-20, 1969, at Washington, D.C., it is explained that a desired goal in the operation of ring furnaces is the maintaining of the temperature within the pits as uniform as possible.
SUMMARY OF THE INVENTION
It is an object of the present invention to provide an improved baffle in the side wall flues of ring furnaces for the purpose of obtaining more uniform temperature distributions in the pits which the side wall flues adjoin.
This as well as other objects which will become apparent in the discussion which follows are achieved, according to the present invention, by providing a ring furnace including pits bounded laterally by side wall flues, the side wall flues being connected in series by means for conducting gases between the side wall flues of the pits, so that heat in previously fired side wall flues can preheat air for combustion in a fired side wall flue and exhaust gases from the fired side wall flue can give up heat to articles in pits bounded by yet-to-be-fired side wall flues, wherein the improvement includes a Y-baffle inverted and centered in at least one of the side wall flues.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a plan, cross sectional view of a portion of a prior art ring furnace, the view being taken on the plane I--I of FIG. 2;
FIG. 2 is a cross sectional view taken on the plane II--II of FIG. 1; and
FIG. 3 is a view, as in approximately one-fourth of FIG. 1, of a ring furnace flue incorporating the improvement of the present invention.
DETAILED DESCRIPTION
Referring firstly to FIGS. 1 and 2, these illustrate a prior art ring furnace. In FIG. 1, the portions of six sections of a ring furnace are shown. For section 10, for instance, the drawing shows all of pit 12 and parts of pits 11 and 13. As noted by Nelson, supra, there may be six to nine pits to a section. The exemplary upright side wall flues 14 and 15 bound pit 12 laterally. Within flue 15 is situated a baffle 16 whose function will be explained below.
At the particular point in time at which this illustration in FIGS. 1 and 2 is made, let it be assumed arbitrarily that fuel is being introduced into flue 17 through opening 38 downwardly in the direction of arrow A, at that end of the flue at which air for combustion of the fuel is flowing into the flue in the manner indicated by arrow B. This air has already been preheated in flues 18, 19, etc. by heat in these flues supplied essentially from hot, but cooling, anodes in pits 20, 21 and 22, 23. The flame in flue 17 descends in its right half and reaches upwards in its left half as indicated by arrow C. Hot products of combustion move along the line of arrow D into flue 15 and act to bring green (i.e. as yet unbaked, or only partially baked) anodes in pits 12, etc. further upwards in temperature, toward the temperature that they will eventually reach, when firing from opening 38 is ceased and firing from opening 24 is begun. Baffles, for instance baffles 16 and 25, are situated in each flue for the purpose of preventing the gas flow from short circuiting between, for example, the inlet and outlet passages 26 and 27 at the opposed upper corner regions of flue 17.
In accordance with the present invention, baffle 25, 16, or one of those unnumbered, is replaced by a similarly centered, inverted Y-baffle 28, as illustrated in FIG. 3. At the larger scale of FIG. 3, as compared with FIG. 2, it has been possible to indicate in FIG. 3 that baffles, in general, are made of bricks. Isolated tie bricks (not shown) generally also extend across the width of flues and into the flue walls at appropriate intervals to lend added strength to the flue construction. Additionally, it is the general practice to make the bricks of the baffles long enough that they extend into the walls of the flues, in order to support the baffles, and, thus, cross hatching on the individual bricks of baffle 28 has been omitted only for the purpose of simplifying the drawings.
Preferably, all of the baffles shown in FIGS. 1 and 2 are replaced by the inverted Y-baffle of the present invention. It has been discovered that this simple change in the baffle form leads to a more uniform temperature in the pits. At the same time, there is no significant increase in the pressure drop experienced by the gases as they flow through a flue.
In FIG. 3, there are illustrated, in °C, the temperatures obtained in a pit bounded on both sides by fired side wall flues each containing an inverted Y-baffle 28. The locations of the temperature values in the figure correspond to the locations on the center line in the adjoining pit where those temperatures exist. Those temperatures in parentheses are for a baffle 25, i.e. for conventional practice, while those figures without parentheses are for the inverted Y-baffle of the present invention. In this illustrative example, the flue dimensions in the figure were approximately ten feet by ten feet, while the flue width (i.e. as measured into and out of the plane of FIG. 3) was approximately six and three-fourths inches. Dimension W was 3-inches, dimension X was 2-inches, dimension Y was 27-inches and dimension Z was 21-inches. Thus, this FIG. 3 is approximately to scale. In both the measurements with the standard baffle 25 and those with the Y-baffle, the same fuel input was used.
The mean pit temperature in these comparative tests was 1030°C for the standard baffle 25 and 1045°C for the inverted Y-baffle. For the Y-baffle, the standard deviation from the mean temperature was 68°C, while for the standard baffle the corresponding standard deviation was 82°C; these standard deviations, in particular, show that a more uniform temperature is being obtained through the use of the inverted Y-baffle. Also evident from this data is the face that, because greater uniformity in temperature has been obtained, it is safe to operate at a higher mean pit temperature, without there being worry that high deviations above the mean pit temperature will result in refractory failure somewhere within the flue.
We are not as yet sure that we have arrived at the optimum inverted Y-baffle. For instance, we believe it may be possible to vary dimensions W, X, Y, and Z and obtain yet further improvements in temperature uniformity. Thus, dimensions Y and Z may be made smaller for the purpose of bringing the legs 32 and 33 of the inverted Y closer to the corners 29 and 30 to increase the corner temperature further. Also, the dimension X at the apex can be made zero, i.e. there is then no gap in the bricks at the apex. Another possibility is to make the design somewhat unsymmetric, for example, by removing just brick 31 when dimension X is zero. It will be appreciated that the purpose of these contemplated changes is to work toward increasing the temperature at those areas which have remained still relatively cool in the temperature map superimposed on FIG. 3.
It will be understood that the above description of the present invention is susceptible to various modifications, changes, and adaptations and the same are intended to be comprehended within the meaning and range of equivalents of the appended claims.
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A ring furnace including pits bounded laterally by side wall flues, the side wall flues being connected in series by means for conducting gases between the side wall flues of the pits, so that heat in previously fired side wall flues can preheat air for combustion in a fired side wall flue and exhaust gases from the fired side wall flue can give up heat to articles in pits bounded by yet-to-be-fired side wall flues, wherein the improvement includes a Y-baffle inverted and centered in at least one of the side wall flues.
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FIELD OF THE INVENTION
[0001] The invention relates to the field of printing systems, and in particular, to print job management.
BACKGROUND
[0002] Printers are common peripheral devices attached to computers. A printer allows a computer user to make a hard copy of documents that are created in a variety of applications and programs on a computer. To function properly, a channel of communication is established (e.g., via a network connection) between the printer and the computer to enable the printer to receive commands and information from the host computer.
[0003] Once a connection is established between a workstation and the printer, printing software is typically implemented at a print server to manage a print job from job entry and management through the complete printing process. Print servers have the ability to route print jobs to multiple different printers by maintaining queues to each serviced printer.
[0004] Typically, a printer operator has the ability to move jobs between queues. There are several reasons as to why an operator may choose to move a job from one printer queue to another. For example, an operator may discover that the time to print the job may take excessively longer remaining in the current queue than if moved to another queue with fewer print jobs.
[0005] Currently, some host server printing software has the ability to provide time estimates for completing a print job at a particular printer based on basic knowledge about the printer (e.g., printer model X prints at 90 pages per minute (ppm)). However, many variables effect the actual print time of a job. Such variables include a time to switch between simplex and duplex, size of the medium sheet, switching between input drawers, time to fold, staple, trim, and/or bind a job, and time to perform automated or manual maintenance or calibration, etc. Thus, time estimates provided by printing software are often inaccurate.
[0006] Accordingly, an improved mechanism for providing a time estimate to complete a print job is desired.
SUMMARY
[0007] In one embodiment, a method is disclosed. The method includes receiving a print job, transmitting a query to two or more printers requesting a time estimate to print the print job at each of the two or more printers, receiving the time estimates from the two or more printers and selecting a first of the two or more printers at which the print job is to be printed based on the received time estimates
[0008] Another embodiment discloses a print server including a printing software product. The printing software product transmits a query to two or more printers requesting a time estimate to print a print job at each of the two or more printers, receives the time estimates from the two or more printers and selects a first of the two or more printers at which the print job is to be printed based on the received time estimates.
[0009] In yet a further embodiment a printing system is disclosed. The printing system includes a print server to receive a print job and a printer to receive a query from the print server, calculate a time estimate to print the print job and transmit the time estimate to the print server.
BRIEF DESCRIPTION OF THE DRAWINGS
[0010] A better understanding of the present invention can be obtained from the following detailed description in conjunction with the following drawings, in which:
[0011] FIG. 1 illustrates one embodiment of a data processing system network;
[0012] FIG. 2 is a flow diagram illustrating one embodiment of a print job time estimation process; and
[0013] FIG. 3 illustrates one embodiment of a computer system.
DETAILED DESCRIPTION
[0014] A print job completion estimation mechanism is described. In the following description, for the purposes of explanation, numerous specific details are set forth in order to provide a thorough understanding of the present invention. It will be apparent, however, to one skilled in the art that the present invention may be practiced without some of these specific details. In other instances, well-known structures and devices are shown in block diagram form to avoid obscuring the underlying principles of the present invention.
[0015] Reference in the specification to “one embodiment” or “an embodiment” means that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment of the invention. The appearances of the phrase “in one embodiment” in various places in the specification are not necessarily all referring to the same embodiment.
[0016] FIG. 1 illustrates one embodiment of a data processing system network 100 . Network 100 includes a data processing system 102 , which may be either a desktop or a mobile data processing system, coupled via communications link 104 to network 106 . In one embodiment, data processing system 102 is a conventional data processing system including a processor, local memory, nonvolatile storage, and input/output devices such as a keyboard, mouse, trackball, and the like, all in accordance with the known art.
[0017] In one embodiment, data processing system 102 includes and employs the Windows operating system, or other operating system, and/or network drivers permitting data processing system 102 to communicate with network 106 for the purposes of employing resources within network 106 . Network 106 may be a local area network (LAN) or any other network over which print requests may be submitted to a remote printer or print server.
[0018] Communications link 104 may be in the form of a network adapter, docking station, or the like, and supports communications between data processing system 102 and network 106 employing a network communications protocol such as Ethernet, the AS/400 Network, or the like.
[0019] According to one embodiment, network 106 includes a print server 108 that serves print requests over network 106 received via communications link 110 between print server 108 and network 106 . Print server 108 subsequently transmits the print requests via communications link 110 to one of printers 109 for printing, which are coupled to network 106 via communications links 111 . In one embodiment, communications links 111 may include a Simple Network Management Protocol (SNMP). However, other communications protocols (e.g., Job Message Format (JMF)) may be implemented.
[0020] In one embodiment, the operating system on data processing system 102 allows a user to select the desired print server 108 and submit requests for service requests to either printer 109 via print server 108 over network 106 . In a further embodiment, print server 108 includes a print queue corresponding to each printer 109 , where each queue includes print jobs requested by remote data processing systems 102 .
[0021] According to one embodiment, print server 108 implements a printing software product that manages the printing of documents between data processing system 102 and printers 109 . In other embodiments, the printing software product manages printing of documents from multiple data processing systems 102 to the one or more printers 109 .
[0022] According to one embodiment, the printing software product may be implemented using either InfoPrint Manager (IPM) or InfoPrint ProcessDirector (IPPD), although other types of printing software may be used instead. In a further embodiment, data processing system 102 includes a print application that interacts with the printing software product at printer server 108 to provide for efficient transmission of print jobs.
[0023] In one embodiment, the printing software product includes a graphical user interface (GUI) 120 that enables a system administrator (or operator) to interact with the printing software product and print application. In a further embodiment, the printing software product (either automatically or under operator control) has the ability to query a printer 109 as to an approximate amount of time that will be required to process one or more print jobs that are pending in a queue associated with the printer 109 . In such an embodiment, printers 109 calculate a time estimate to process the pending print jobs and/or a print job the printing software product is considering submitting. Subsequently, the printers 109 report the estimate to the printing software product.
[0024] FIG. 2 is a flow diagram illustrating one embodiment of a print job time estimation process. At processing block 210 , a print job is received at the printing software product from a data processing system 102 . At processing block 220 , the printing software product queries one or more printers 109 for an estimation of duration and time to print the job. In one embodiment, the query includes a transmission of the print job along with the request for time estimation.
[0025] In another embodiment, the query includes a job description. In such an embodiment, the job description includes a Job Definition Format (JDF) job ticket describing the media to be used for the job in the exact order it will be used. In other embodiments, the job description may include a number for each page size included in the job, or a simple list of media requests. In yet another embodiment, the query may include a basic PostScript program (or print job in other page description language) including blank/null pages with just the media selection commands the job for estimation.
[0026] At processing block 230 , each queried printer 109 performs the estimation. In one embodiment, the estimation is based on size of the print job, number and size of print jobs currently in the queue and printer performance capabilities (e.g., pages printed per minute). Additionally, printers 109 consider other factors in the estimation calculation (e.g., time to switch between simplex and duplex, size of the medium sheet, switching between input drawers, time to fold, staple, trim, and/or bind a job, and time to perform automated or manual maintenance or calibration, print resolution, print quality setting, print speed setting, paper weight, paper thickness, dryer or fuser temperature, simplex printing speed vs. duplex printing speed, color vs. monochrome speed, etc.).
[0027] At processing block 240 , the query estimates (e.g., job duration and theoretical completion time (assuming job submitted now and no other job submitted before)) are received back at the printing software product. At processing block 250 , the printing software product selects the printer 109 to which the print job is to be transmitted for processing based on the received estimation calculations. At processing block 260 , the job is forwarded to the selected printer 109 where it is printed.
[0028] In an embodiment where the full job is transmitted for estimation, printer 109 may hold on to the job without having started it yet. Subsequently, the printing software product would command for the job to be submitted to the print queue upon selection of the printer 109 . This process prevents having to transmit the job across the network twice.
[0029] FIG. 3 illustrates a computer system 300 on which data processing system 102 and/or server 108 may be implemented. Computer system 300 includes a system bus 320 for communicating information, and a processor 310 coupled to bus 320 for processing information.
[0030] Computer system 300 further comprises a random access memory (RAM) or other dynamic storage device 325 (referred to herein as main memory), coupled to bus 320 for storing information and instructions to be executed by processor 310 . Main memory 325 also may be used for storing temporary variables or other intermediate information during execution of instructions by processor 310 . Computer system 300 also may include a read only memory (ROM) and or other static storage device 326 coupled to bus 320 for storing static information and instructions used by processor 310 .
[0031] A data storage device 327 such as a magnetic disk or optical disc and its corresponding drive may also be coupled to computer system 300 for storing information and instructions. Computer system 300 can also be coupled to a second I/O bus 350 via an I/O interface 330 . A plurality of I/O devices may be coupled to I/O bus 350 , including a display device 324 , an input device (e.g., an alphanumeric input device 323 and or a cursor control device 322 ). The communication device 321 is for accessing other computers (servers or clients). The communication device 321 may comprise a modem, a network interface card, or other well-known interface device, such as those used for coupling to Ethernet, token ring, or other types of networks.
[0032] Embodiments of the invention may include various steps as set forth above. The steps may be embodied in machine-executable instructions. The instructions can be used to cause a general-purpose or special-purpose processor to perform certain steps. Alternatively, these steps may be performed by specific hardware components that contain hardwired logic for performing the steps, or by any combination of programmed computer components and custom hardware components.
[0033] Elements of the present invention may also be provided as a machine-readable medium for storing the machine-executable instructions. The machine-readable medium may include, but is not limited to, floppy diskettes, optical disks, CD-ROMs, and magneto-optical disks, ROMs, RAMs, EPROMs, EEPROMs, magnetic or optical cards, propagation media or other type of media/machine-readable medium suitable for storing electronic instructions. For example, the present invention may be downloaded as a computer program which may be transferred from a remote computer (e.g., a server) to a requesting computer (e.g., a client) by way of data signals embodied in a carrier wave or other propagation medium via a communication link (e.g., a modem or network connection).
[0034] Whereas many alterations and modifications of the present invention will no doubt become apparent to a person of ordinary skill in the art after having read the foregoing description, it is to be understood that any particular embodiment shown and described by way of illustration is in no way intended to be considered limiting. Therefore, references to details of various embodiments are not intended to limit the scope of the claims, which in themselves recite only those features regarded as essential to the invention.
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A method disclosed. The method includes receiving a print job, transmitting a query to two or more printers requesting a time estimate to print the print job at each of the two or more printers, receiving the time estimates from the two or more printers and selecting a first of the two or more printers at which the print job is to be printed based on the received time estimates.
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BACKGROUND
[0001] The present invention relates generally to the field of power electronic devices, and particularly to a hardware architecture for motor control drives to provide interfaces for communication and control of motors and processes.
[0002] A wide variety of applications exist for power electronic devices, such as switching devices and systems. In such systems, multiple components may be combined and interconnected for a wide range of functionality. For example, in traditional switchgear applications, such as motor drives, an enclosure is generally provided into which power is routed, along with network signals, sensor inputs, actuator outputs, and so forth. Components within the enclosure are interconnected with external circuitry, and can be interconnected with one another to provide for control, monitoring, circuit protection, and a multitude of other functions. Such conventional approaches, however, require a substantial number of terminations of various conductors, routing of conductors, mounting of various components, and so forth.
[0003] In other types of packaging, components may be associated with one another in mounting areas or bays, which are electrically coupled to buses for routing power to the various components. Examples of this type of packaging may be found in conventional motor control drives, in which various control, monitoring and protective circuits are mounted and interconnected with one another via wiring harnesses, cables, and so forth. In other applications, particularly where power levels are much lower, it has become conventional to provide a “backplane” to which components may be coupled, such as via plug-in connections. Such backplanes are currently in use throughout industrial applications, as for providing data and control signals to and from programmable logic controllers, computer components and peripherals, and so forth. The use of such backplanes, through which data and control signals can be easily routed, presents substantial advantages from the point of view of ease of assembly, replacement, servicing and expansion of overall systems incorporating a large number of interfaced components.
[0004] However, for backplanes using multiple components receiving any number of signals, the routing and timing of such signals to the motor control drive may present hardware and software challenges. The signaling must operate in such a way so that each signal reaches the main processing unit of the motor control drive and may be processed quickly enough to ensure a timely response. Additionally, where synchronization of multiple motors is required, synchronization of the signals of multiple motors and sensors also presents additional challenges.
BRIEF DESCRIPTION
[0005] The present invention provides a novel approach to configuration and management of motor drives and synchronization of signals of such drives. The approach includes a motor drive having a control board and one or more option boards physically connected to the motor drive via a backplane. The motor drive may load a profile for the option board that includes a configuration for the option board. The profile may include a unique identifier and one or more interrupts for the option board.
[0006] Methods, devices, and computer programs are all supported for performing these and other functions of the invention.
DRAWINGS
[0007] These and other features, aspects, and advantages of the present invention will become better understood when the following detailed description is read with reference to the accompanying drawings in which like characters represent like parts throughout the drawings, wherein:
[0008] FIG. 1 is a perspective view of a motor drive in accordance with an embodiment of the present invention;
[0009] FIG. 2 is a block diagram of a motor drive system in accordance with an embodiment of the present invention;
[0010] FIG. 3 is a schematic diagram of the power electronic switching circuitry of FIG. 2 in accordance with an embodiment of the present invention;
[0011] FIG. 4 is a block diagram of multiple motors and drives controlling a process in accordance with an embodiment of the present invention;
[0012] FIG. 5 is a perspective view of a pod and backplane in accordance with an embodiment of the present invention;
[0013] FIG. 6 is a cutaway perspective view of the pod and backplane of FIG. 5 in accordance with an embodiment of the present invention;
[0014] FIGS. 7-10 are perspective views of option boards configured to be used with the pod and backplane of FIGS. 5 and 6 in accordance with an embodiment of the present invention;
[0015] FIG. 11 is a block diagram illustrating connections between a control board and various option boards in accordance with an embodiment of the present invention;
[0016] FIG. 12 depicts an interrupt scheme utilizing a “Control Event” signal and “System Event” signal for synchronized operation of a control board and option boards in accordance with an embodiment of the present invention;
[0017] FIG. 13 depicts a process for operation of a control board and option board using a profile in accordance with an embodiment of the present invention;
[0018] FIGS. 14 and 15 depict screenshots a user interface for configuring a control board and option board in accordance with an embodiment of the present invention; and
[0019] FIG. 16 is a diagrammatical representation of a pair of motor drives, illustrating how multiple drives may be synchronized down to a functional circuit level.
DETAILED DESCRIPTION
[0020] Beginning now with FIG. 1 , a perspective view of a motor drive 100 is depicted. In one embodiment, the motor drive 100 may be a PowerFlex drive manufactured by Rockwell Automation of Milwaukee, Wis. The motor drive 100 may include a housing 102 having cooling vents 104 on one or more sides of the drive 100 . To facilitate interacting with the motor drive 100 , the motor drive 100 may include a human-machine interface (HMI) 106 . The HMI 106 may include a display 108 , such as an LCD or other display and a keypad 110 allowing input by a user. Additionally, the HMI 106 may be removable and dockable in a receptacle 114 in the housing 102 .
[0021] As described further below, the motor drive is adapted to receive three-phase power from a power source, such as the electrical grid and to convert the fixed frequency input power to controlled frequency output power. The motor drive 100 may manage both application of electrical power to the loads, typically including various machines or motors. The drive may also collect data from the loads, or from various sensors associated with the load or the machine system of which the load is part. Such data may be used in monitoring and control functions, and may include parameters such as current, voltage, speed, rotational velocity, temperatures, pressures, and so forth. The motor drive 100 may be associated with a variety of components or devices (not shown) used in the operation and control of the loads. Exemplary devices contained within the motor drive 100 are motor starters, overload relays, circuit breakers, and solid-state motor control devices, such as variable frequency drives, programmable logic controllers, and so forth. As discussed further below, the motor drive 100 may include expandable functionality through the addition of option boards installed in a backplane inside the motor drive 100 . Additionally, the motor drive 100 may be used in conjunction with other motor drives, such that a plurality of motor drives may be used to control one or more processes. As also discussed below, functions within the drive are synchronized, and the drive (and its internal functions) may be synchronized with other drives in an overall machine system.
[0022] FIG. 2 is a block diagram 200 illustrating various internal components of the drive 100 and other devices in the system 200 . For example, the drive 100 may include control circuitry 202 , driver circuitry 204 , and power electronic switching circuitry 206 . The power electronic switching circuitry 206 may receive three-phase power 212 , and output three phase power 214 to a motor 216 . To facilitate control of the motor drive 100 , a remote control monitor 208 may be connected to the motor drive 100 . Additionally, other drives 210 may also be connected to the motor drive 100 and the remote control monitor 208 , such as via a network. Remote control and monitoring functions, and coordinated operation of the drive may be performed via such network connections. Moreover, such networks and network connections may be based on any known or subsequently developed standard, including standard industrial protocols, Ethernet protocols, Internet protocols, wireless protocols, and so froth.
[0023] The control circuitry 202 and driver circuitry 204 may include a control circuit board and various optional function circuits, referred to herein as “option boards”, in accordance with an embodiment of the present invention, as discussed further below. The driver circuitry 204 signals the switches of the power electronic switching circuitry 206 to rapidly close and open, resulting in a three phase waveform output across the output terminals 218 , 220 , and 222 . The driver circuitry 204 is controlled by the control circuitry 202 , which may operate autonomously, or which may respond to command inputs from the remote control monitor 208 through a network. Similarly, operation of the driver circuitry may be coordinated, via the control circuitry, with that of other drives. Many different control schemes and functions may be implemented by the control circuitry, and programs for such operation may be stored on the control board, such as for closed loop speed control, closed loop torque control, among many others.
[0024] FIG. 3 is a schematic diagram of power electronic switching circuitry 206 . As mentioned above, the power electronic switching circuitry will typically receive as an input three phase power 214 , such as from the power grid. The three phase power source is electrically coupled to a set of input terminals 226 , 228 , and 230 that provide three phase AC power of constant frequency to rectifier circuitry 232 . The rectifier circuitry 232 includes components, such as diodes 234 that perform full wave rectification of the three phase voltage waveform. After rectification, all phases of the incoming power are combined to provide DC power to the low side 236 to the high side 238 of a DC bus. Inductors 240 may be coupled to both the high and low sides of the DC bus and act as chokes for smoothing the rectified DC voltage waveform. One or more filter capacitors 242 may link the high side 238 and low side 236 of the DC bus and are also configured to smooth the rectified DC voltage waveform. Together, the inductors and capacitors serve to remove most of the ripple from the waveform, so that the DC bus carries a waveform closely approximating a true DC voltage. It should be noted that the three-phase implementation described herein is not intended to be limiting, and the invention may be employed on single-phase circuitry, as well as on circuitry designed for applications other than motor drives.
[0025] An inverter 244 is coupled to the DC bus and generates a three phase output waveform at a desired frequency for driving a motor 216 connected to the output terminals 218 , 220 , and 222 . In the illustrated embodiment, within the inverter 244 , for each phase, two insulated gate bipolar transistors (IGBT's) 246 are coupled in series, collector to emitter, between the high side 238 and low side 236 of the DC bus. Three of these transistor pairs are then coupled in parallel to the DC bus, for a total of six transistors 246 . Each of the output terminals 218 , 220 , and 222 is coupled to one of the outputs between one of the pairs of transistors 246 . The driver circuitry 204 signals the transistors 246 to rapidly close and open, resulting in a three phase waveform output across output terminals 218 , 220 , and 222 . The driver circuitry 204 is controlled by the control circuitry 202 .
[0026] In some embodiments, multiple motor drives and motors may be used to control a process. For example, as illustrated in FIG. 4 , a process 302 may be controlled by multiple motors 304 such as a first motor M 1 , a second motor M 2 , a third motor M 3 , and a fourth motor M 4 . Each motor 304 may be controlled by a respective motor drive 306 . For example, the motor M 1 may be controlled by motor drive D 1 , the motor M 2 may be controlled by motor drive D 2 , the motor M 3 may be controlled by motor drive D 3 , and the motor M 4 may be controlled by the motor drive D 4 . The motor drives 306 may be connected together via a network 308 , such as a network employing a known standard communications protocol, such as industrial DeviceNet, ControlNet, or Ethernet. A remote control and monitoring station 310 may be connected to the motor drives by the network 308 to provide for control and monitoring of the drives 306 , the motors 304 and the process 302 .
[0027] As discussed above, in some embodiments a motor drive may add functionality, connections, or both through the addition of option boards installed in the motor drive. The option boards may be in communication with other motor drives, motors, sensors, or other devices. As discussed above with respect to FIG. 4 , for example, multiple drives and motors may be used to control a process. In accordance with an embodiment of the present invention, a motor drive may provide one or more serial interfaces for the addition of option boards. Additionally, to facilitate control of highly synchronized drives and motors, the dedicated serial interface may provide synchronization between each of the option boards and the control board or circuitry of the respective motor drive through the use of synchronized interrupts. Additionally, the communication and synchronization between the option boards and the control board may be selected and configured by user, such that different communication speeds may be enabled while maintaining the synchronization. Further, some embodiments may include profiles to select and configure the communication and synchronization of the option boards.
[0028] To facilitate addition of the option cards, a motor drive may include a “pod” 400 having a chassis 402 as shown in FIG. 5 . The pod 400 may be mounted inside a motor drive, and acts as a modular card rack for the option boards discussed below. The pod 400 may include a control board 404 , which may manage and process signals received from the option boards, as discussed further below. The control board 404 may include one or more processors 406 , (which may include microprocessors, CPU's, field programmable gate arrays, etc.) to provide applications, management and processing. The processor 406 may include or be associated with a memory having applications for operating the control board 404 , the option boards in the pod 400 , or any other device in the motor drive. For example, the processor 406 may include applications such as an interface, torque control, vector control, drive logic, Ethernet logic, etc. The control board 404 may also include a field programmable gate array for communication and simple processing tasks. For example, in an embodiment the field programmable gate array may perform transfer, size, and CRC frame adders and receive frame stripping, CRC verification, error handling and communication status without processor intervention. Additionally, the control board 404 may include additional interfaces for connection to other motor drives or devices in accordance with certain data exchange standards, such as IEEE 1588, Ethernet, etc.
[0029] The pod chassis 402 may include a one or more backplanes 408 , which generally support and provide the physical interconnect between the control board 404 and various option boards. The backplanes 408 may include a printed circuit board having any number of slots, plugs, connectors, or other interface structures. The backplane 408 provides for distribution of power and data signals, and enables the option cards to be interfaced with a network. For example, as shown in FIG. 5 , the backplane 408 includes a plurality of slots 410 , configured to receive various option boards as described further below. In one embodiment, the pod 400 may include two backplanes 408 having six slots 410 each.
[0030] The pod chassis 402 may also include additional features to increase reliability and performance. The chassis 402 may include one or more fans 412 and one or vents 414 on any portion of the chassis 402 to allow for airflow and heat dissipation.
[0031] FIG. 6 is a cutaway view of the pod 400 illustrating the pod 400 and backplanes 408 in further detail. The backplanes 408 may include a bus board 416 providing the interface slots 410 and the necessary bus routing to the control board 404 . The backplane 408 may also include one or more communication ports, such as a multi-pin communication port 418 and an Ethernet port 420 . In one embodiment, the backplanes 408 may have six interface slots and may receive up to six option boards. The backplanes 408 may include one or more receptacles 422 configured to receive one or more screws or other fastener to secure an option board, as discussed below. Of course, any number of such option board slots may be provided, depending upon the range of options contemplated for the system.
[0032] FIGS. 7-10 illustrate various option boards configured to mate with the interface slots 410 . It should be appreciated that some embodiments may include options board not illustrated below that include any number of processors, memory, interfaces, inputs and/or outputs. The options boards may provide any desired functionality, including: input and output; signal conditioning; isolation; data conversion; safety; analog-to-digital (A/D) conversion or other data conversion; and communication via standard protocols such as DeviceNet, ControlNet, and/or Ethernet. As explained further below, various option boards may also include one or more of the following components: processor, FPGA, memory, logic registers, clock, terminals, input/output ports, etc. In the presently contemplated embodiment, special option boards may be developed from time to time to address particular system and application needs, to perform particular types of data processing, interfacing with legacy systems, and so forth.
[0033] For example, beginning with FIG. 7 , a first option board 500 may include a processor 502 and an FPGA 503 . To engage an interface slot 410 , the option board 500 may include a bus interface 504 . As mentioned above, in one embodiment the bus interface 504 may be a 6-pin PCI-E interface. Additionally, the option board 500 may have one or more connectors 506 or terminals 508 for connection to various inputs and outputs used by the option board 500 . To secure the option board 500 to the pod 400 , and the receptacles 418 , the option board 500 may include one or more screws 510 , such as thumbscrews. In some embodiments, other mechanisms may be used to secure the option board 500 , such as clips or other fasteners.
[0034] FIG. 8 depicts another option board 514 also having a bus interface 516 for insertion into the interface slots 410 . The option board 514 includes capacitors 518 , and a processor or FPGA 520 . Additionally, the option board 514 includes input-output terminals 522 , and may include one or more screws 524 . FIG. 9 depicts another option board 528 having a bus interface 530 and one or more screws 532 having functions as described above.
[0035] Finally, FIG. 10 illustrates an option board 536 configured to allow use of a “legacy” option board. For example, the option board 536 includes a legacy board 538 mounted to the option board 536 , such as by one or more screws 540 . In such an embodiment, the legacy board may connect to the option board 536 via any interface suitable for communication with both the option board 536 and the legacy board 538 . The option board 536 may provide any emulation, translation, or other processing necessary for communication with the legacy board 538 . The option board 536 may also include a bus interface (not shown) for communication with the interface slots 410 and may also include one or more screws 540 to secure the option board 536 to the pod 400 . Communication from the legacy board 538 may be routed through the option board 526 and the bus interface for communication to the control board. Advantageously, the control board backplanes 408 and option boards described above allow connection of option boards without wiring or other internal cable connections.
[0036] FIG. 11 is a block diagram 600 illustrating the connections between a control board 602 and a plurality of option boards 604 . The option boards 604 may be connected to the control board by dedicated dual channel full duplex serial interfaces 606 . As discussed above, each option board 604 may include a clock that controls the timing of signaling on the respective serial interface 606 . In some embodiments, the control board 602 and option boards 604 may also include a CAN (DPI) channel. As described further below, each channel may carry different signals, such coordinated by an interrupt scheme based on a “Control Event” on a first channel 608 and a “System Event” on a second channel 610 , and the timing of the signals may be controlled by the clock on the option boards 604 . By using the dedicated serial interfaces 606 , the control board 602 allows transfer for serial communication of information from the option boards simultaneously and in parallel. Additionally, as dictated by the timing of the “Control Event,” the data transfer from each option board 604 may be synchronized.
[0037] As described above, in some embodiments the pod 400 may have two (or more) backplanes, as indicated by a dashed regions 612 and 614 . In the illustrated embodiment, because each backplane 612 and 614 may include three interface slots, which in one embodiment may be PCI-E interface slots, three dedicated serial buses are provided on each backplane. In addition to communication with the control board 602 , the option boards 604 may communicate with each other via a network 616 . By using the network 616 , the option boards 604 may communicate with each other without first routing the communication through the control board 602 . In other embodiments, the option boards 604 may route communication to other options boards on the same backplane or an adjacent backplane via the control board 602 .
[0038] As described above, in a presently contemplated embodiment, each channel of the dual channel full duplex serial interfaces 606 may transmit a specific signal. In this embodiment, the signal processing may be implemented by means of an FPGA on the control board 602 . In other embodiments the signal processing may be implemented in software and may use a processor on the control board 602 . FIG. 12 depicts the signals defining the interrupt scheme in further detail, such as a “Control Event” (CTRL) signal 700 and a “System Event” (SYS) signal 702 . In one embodiment, the Control Event signal 700 may be used to coordinate the transfer and collection of data at very short intervals, such as data needed for commutation or generation of the output waveform, while the System Event signal 702 may be used to coordinate transfer and collection of less time-critical data, such as multiple types of system level messages, such as general feedback, communications, I/O, and so forth.
[0039] To ensure synchronization, regardless of the clock timing of each option board, each signal 700 and 702 may have a data acquisition interval and a transfer interval. For example, the Control Event signal may include a data acquisition window 704 and a transfer interval 706 . In one embodiment, the data acquisition window 704 for the Control Event signal may about 6 μs, and the transfer interval may be about 128 μs to about 256 μs. At the end of the data acquisition window, a processor on the control board is interrupted, e.g., via an IRQ, to ensure no wasted idle or wait time is consumed by the CPU. By providing a data acquisition window 704 , the control board is ensured of receiving all data from the option boards in the pod. Thus, in a presently contemplated embodiment, the rising edge 708 of the Control Event signal, the option boards may shift their register to the control board within the 6 μs window. The clock rate of the option boards may be set at the appropriate level to ensure this data is transferred in the data acquisition window. The clock rate may be standardized at 32 MHz, although other rates may be employed. Advantageously, this ensures that all registers (signals) from the options boards will be synchronized. That is, no matter when each option board acquired its data, all options board must report to the control board by the end of the data acquisition window. In one embodiment, the Control Event signal may be referred to as a “Control Event Primary” signal and may be used for control task (commutation) data acquisition from the option cards, such as for such data as torque references, encoder feedback, etc. Further, to facilitate communication with the serial interface, the option boards may include a shift register interface having a 32-bit length, and the transfer rate may controlled by a clock on the option board.
[0040] Similarly, in a presently contemplated embodiment, the System Event signal 702 may include a data acquisition interval 710 and a transfer interval 712 . In such an embodiment, the data acquisition window 710 for the System Event signal 702 may be about 20 μs and the transfer interval may be about 1-2 ms to about 256 μs. In some embodiments, the System Event signal 702 may provide for both a primary and secondary message sent on the data acquisition interval and transfer interval respectively. In such an embodiment, the secondary message must be completed prior to the end of transfer interval. In one embodiment, the primary message may be referred to as a “System Event Primary” and have a 64 byte storage limit, and the secondary message may be referred to as “Secondary Event Continuous” and have a 512 byte storage limit.
[0041] It should be noted that the particular speed, data acquisition interval length, interrupt spacing, and so forth used in the drive may be different from that set forth in the present discussion. For example, the timing of the deterministic interrupt scheme is set based upon such factors as the amount of data to be transferred from the option boards (or from the control circuit to the option boards), and the duration of the data acquisition interval desired, as compared to the duration of the processing window needed. That is, the processing circuitry of the control board will collect and process the data received, and perform the control functions for operation of the motor coupled to the drive, and will need some time to perform such functions. The data acquisition window may be set to a duration that is a function of the anticipated processing time, such as 10%. Such considerations may result in design choices within the ambit of those skilled in the art.
[0042] It will be appreciated that the use of dedicated serial interfaces for each functional circuit (option board), and the interrupt scheme for transfer and collection of data from all such circuits provides a deterministic, synchronous interrupt structure that permits very fast data transfer rates. The serial interfaces essentially function as bit shift registers for the transfer of data without the need for traffic control between the circuits. Similarly, it should be noted that while the rate of transfer of data from the functional circuits may be set, such as at 32 MHz, this rate is actually configurable. Thus, where less data is to be delivered in the available time, a slower data transfer rate from the functional circuit may be set (e.g., as low as 2 MHz), while for more demanding data transfer, even higher rates may be set (e.g., 64 MHz). Moreover, the rates of data transfer from the different option boards, even within a single drive, need not be the same. Different rates may be set for different option boards, while still maintaining synchronization in operation by virtue of the dedicated serial interfaces and deterministic interrupt scheme. Similarly, different data transfer rates may be used for different channels for each board, and these rates may be changed over time. In certain applications the use of different data transfer rates may aid in reducing harmonic distortion or interference between the interfaces and channels.
[0043] The System Event Primary may be used for a “login” function on the serial interface such that each option card may use this signal to log on to the control board and establish communication. The System Event Primary may be used for system task data acquisition, such as analog I/O, digital I/O, feedback, communications, etc. Additionally, in one embodiment the System Event Continuous signal may provide additional communication such as transfer of large data blocks.
[0044] To facilitate communication and interfacing of a control board with the option boards, the control board and/or option boards may use profiles to assist with the “log on” of the option boards. FIG. 13 depicts a process 800 for operation of a control board and option board using a profile in accordance with an embodiment of the present invention. Initially, upon startup of a motor drive having a backplane with a control board as described above, an installed option board is also powered on (block 802 ). The option board sends data to the control board during the data acquisition window of the “System Event” signal (block 804 ), as described above. In response, the control board references a locally stored database (block 806 ) that may store profiles for the various option boards. The control board reads “log on” info received in the data from the option board (block 808 ) that may provide identification information and the state for of option board. The control board then loads the appropriate profile for the option board from the database (block 810 ) and begins communication with the option board (block 812 ).
[0045] In one embodiment, the HMI on a motor drive may provide a user interface for accessing, managing, and configuring the option boards installed in a pod of the motor drive. As mentioned above, the user interface may be provided on a processor and a memory of the control board. In many applications, however, the initial configuration of the drive will be performed by coupling the drive to a workstation, which may include a conventional programmed computer (e.g., personal computer). Screen views provided by software on the workstation, or served by the drive to the workstation facilitate in selecting parameter settings, units of measure, parameter names, and so forth. The profile for each option board, moreover, greatly facilitates this process, and each profile may already preconfigure certain of the settings for the option board, or may reduce the set of options presented to the installer or system integrator to those available or appropriate to that option board and selected system setup. The profiles may thus be part of an automatic device configuration scheme, streamlining setup of the drives by reducing the information presented to the installer and guiding the installer though the setup. It is presently contemplated that such individual profiles may be stored on the option boards (i.e., each option board including its respective profile), and fed to the control board, or a library of profiles may be stored on the control board, and an appropriate profile used for configuration of a specific option board if it is recognized as present in the drive by the control board. Such profiles may also be downloaded to the drive from a library, such as via the network connection provided to the drive, or upon initial installation. Certain of these options may allow for expansion of the number and types of functional circuits available over time.
[0046] FIGS. 14 and 15 depict screenshots of such a user interface in accordance with an embodiment of the present invention. FIG. 13 depicts a first screen 900 having a left hand navigation pane 902 and a right hand parameter pane 904 . As illustrated in FIG. 14 , the navigation pane 902 includes list of the control boards and associated option boards for a motor drive. The control boards may be listed as nodes in the navigation pane and may include any number of collapsible parameters and device underneath. For example, a first node 908 (Node 1 ) corresponds to the “PowerFlex 755” control board. Underneath the first node 908 various parameters 910 are listed. The option boards 912 may also be listed underneath the first node 908 . In one embodiment, the option boards 912 may be arranged according to the interface slots occupied by the option board. For example, a first option board 914 (LCD Module) may be listed in slot 1 , a second option board 916 (20-COMM-E-Ethernet/IP) may be listed in slot 2 , etc.
[0047] By selecting a node 908 , e.g., a control board 908 , or an option board 912 , a user may display the parameters associated with that control board or option board. For example, the right hand pane 904 a list of parameters is displayed, such as the speed parameters 914 . The right hand pane 904 may display information about each item listed, including a node column 916 , a slot column 918 , and a parameter number 920 , with each column displaying the node, slot and parameter respectively of each item. To configure a node, a user may select a parameter, as illustrated by the selected parameter 922 (Speed Ref A Set, e.g., a speed reference).
[0048] As shown in FIG. 15 , the second screen 924 illustrates a pop-up window 926 that displays after selection of a parameter. The pop-up window 926 corresponds to the selected parameter 922 and provides a number of selections. As shown, a first tab 928 (List Selection) displays the port 930 , the parameter 938 , the value 940 and the internal value 942 . Additionally, a minimum value 944 , a maximum value 946 , and a default value 948 may also be set. The port 930 may display a drop down box corresponding to the port or slot selectable by the user. To configure the parameter 922 for a specific port, a user may select the port from the drop down menu 950 , such as selecting port (node) 0 , port 4 , port 5 , etc. After the port 930 is selected, the parameter 938 may be configured by entering a new value. Additional tabs in the pop-window 926 may include additional functionality, such as a “Numeric Edit” tab 952 and an “Advanced tab” 954 . The “Numeric Edit” tab 952 may allow direct editing of numeric parameters, and the “Advanced tab” 954 may include additional configuration operations for the selected parameter 922 . In this manner, a user may configure of any option boards coupled to the backplane of a motor drive. It should be noted that any number of drives may be configured in a similar manner, particularly where numerous drives are networked together in a system. Thus, the system integrator may navigate to a specific drive for its configuration, then to other drives for configuration of the overall system.
[0049] The interrupt scheme described above permits synchronization of all functions within the motor drive, including the acquisition of data from all functional circuits supported on the option boards. That is, because all data is received serially from all of the option board functional circuits and in response to the Command and System interrupts, all of the data is assured of being received by the control circuitry at the same time. Once received, the data can be acted upon by the processing capabilities of the control circuitry in the interim between interrupts. For data that directly affects motor control, sometimes referred to as communication data, the data acquisition is particularly fast, with little time between the interrupts. For other data, the intervals may be more widely spaced in time.
[0050] The same interrupt scheme, and close synchronization of data acquisition can also allow for very accurate synchronization between drives linked to one another via a network. For example, FIG. 16 illustrates a system 1000 in which two motor drives 1002 and 1004 are interconnected to maintain synchronization. Drive 1002 includes a control circuit 1006 of the type described above, coupled to functional circuits 1008 . As in the embodiments described above, the control circuit will typically be supported separately from the functional circuits, such as on a control board, while the functional circuits are supported on option boards. The number and type of such option boards may vary depending upon the system requirements, the type of control to be performed, and so forth. Also as described above, the control circuit communicates with the functional circuits via dedicated serial interfaces, and coordinates the transfer and collection of data from the functional circuits by interrupts, thus maintaining precise synchronization of all drive operations down to the option board level. The control circuit utilizes data collected from the functional circuits to provide control signals to drive circuit 1010 , which powers solid state switches to produce output power for a motor 1012 , as described above.
[0051] Drive 1004 is similarly configured. It includes a control circuit 1014 and a series of functional circuits 1016 that communicate with the control circuit 1014 via dedicated serial interfaces, with data transfer again being coordinated via interrupts as described above. The control circuit 1018 similarly produces control signals that are applied to drive circuit 1018 for driving motor 1020 .
[0052] In system 1000 , the operation of motors 1012 and 1020 is coordinated and synchronized, such as for “multi-axis” control. Such coordinated control is extremely useful in many applications, such as integrated machines in which motors handle product in continuous processes. Examples may include printing applications, paper making applications, product handling applications, and so forth, to mention only a few.
[0053] To permit such high degree of synchronization, a synchronization counter 1022 , or similar device, is included in each drive, and synchronizes the clock of the control circuit for that drive with that of other drives interconnected in the system. In a presently contemplated embodiment, the drives are interconnected via a network connection 1024 , which utilizes an Ethernet communications protocol, although other protocols may be used. The coordination of the synchronization counters is performed in accordance with IEEE 1588 standards.
[0054] It has been found that the use of such clock synchronization between drives, in conjunction with the use of dedicated serial interfaces for functional circuits, and the interrupt scheme for transfer and collection of data from the functional circuits permits an unprecedented degree of coordination and synchronization of the drives. That is, in the overall system, all functional circuits (e.g., input/output circuits, communications circuits, encoders, parameter estimation/calculation circuits, etc.) of all drives can be precisely coordinated insomuch as the interrupts for transfer and collection of data from all such circuits occurs at the same time, as coordinated by synchronization of the clocks of all drives. Such coordination allows the drives to be used in applications and with a degree of precision that was heretofore unavailable in similar production equipment.
[0055] While only certain features of the invention have been illustrated and described herein, many modifications and changes will occur to those skilled in the art. It is, therefore, to be understood that the appended claims are intended to cover all such modifications and changes as fall within the true spirit of the invention.
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A motor drive is provided that includes a control circuit or board and a one or more functional circuits or option boards coupled to the control board, and a profile that includes a configuration for the option board. A method of operating a motor drive that includes loading a profile for a option board coupled to a control board of the controller, wherein the profile comprises a configuration for the option board. A tangible machine-readable medium implementing the method is also provided.
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BACKGROUND OF THE INVENTION
This invention relates to new and useful improvements in a ventilation system for the crankcase of an internal combustion engine.
1. Field of the Invention
Blow-by gases and vapors, such as moisture in the form of steam, hydrocarbons, and unburned fuel, enter the crankcase lubricating oil chamber during IC. engine operation, the gases and vapors occuring because of leakages past the piston rings during operation cycles.
If not removed as fast as they are introduced into the crankcase, contamination of the lubrication oil ensues. This condition has existed since the first IC engine was put into service.
Lubricants are formulated with an additive package for the purpose of suspending and emulsifying extraneous particles picked up from the atmosphere and blow-by vapors, plus gums, varnishes, tars, and acids generated by the combustion process.
Ventilating or scavenging crankcase systems in the past have attempted to provide a method for removing these undesirable particles into the atmosphere by a pressure method.
In normal operation of a reciprocating I.C. engine there is a certain amount of crankcase vapors, continually being developed. These consist in part of gaseous combustion products entering the crankcase by passing between the piston rings and cylinder walls, valve guides and valve stems. This particular portion of the crankcase vapors is often referred to as blow-by.
The crankcase vapors are normally comprised of, fuel, moisture hydrocarbons, soot combustible materials such as atomized oil, diesel fuel, and heavy particulate resulting from engine operation.
The releasing of such vapors and gases into ambient atmosphere is directly related to the development of a smog atmosphere. Obviously, the development of a means for reducing air pollution due to engine operation is a desideratum.
2. Description of the Prior Art
Numerous devices are known to the prior art which function to remove crankcase vapors and the like from the crankcase and pass same into the air carburetor and filtering system or intake manifold thereof unfiltered. For the most part, these crankcase vapors handling devices use a pushing or self-developed pressure method to release the vapors from the crankcase into the intake manifold without filtering or treating same, which my system does.
Thus, by so doing impregnating the lubricant with contaminates is eliminated, oil usage is prolonged, and less consumption is accomplished.
Some systems have been provided by establishing communication between the crankcase interior and the vacuum process now existing in the engine intake manifold. These systems, however, are plagued with the problem of adequate volumetric control of the undesirable vapors, solids and so on, under all conditions of the engine operation.
An apparatus for treating crankcase vapors is now known of which provides for directly removing the crankcase vapors from the crankcase into the intake manifold of the engine. While it removes the crankcase vapors from the engine, it does not substantially increase the hydrocarbon exhaust pollution due to the crankcase vapors being passed through the engine combustion system because of a depth packed filtering processing system before being introduced to the atmosphere.
Another known apparatus utilizes an indirect exhaust manifold heat exchanger to warm the vapors before they are introduced into the engine intake. Such a heat exchanger is known in the prior art as having a low efficiency which only slightly warms the vapors before they are introduced into the engine. The process of warming crankcase vapors and introducing them directly into the engine intake does not make them more significantly suitable for combustion to pollute the atmosphere.
With a gas engine running at idling speed and minimum load conditions, the throttle valve of the carburetor is substantially closed and hence, develops a maximum vacuum downstream of the throttle valve. During such a phase of engine operation, there is a minimum of leakage of gases, vapors and solids into the crankcase chamber. Like the prior application, a diesel engine has little vacuum in the intake air system at idle, this being the necessity of the compressor in constant use as is the operation of the evaculator system.
This constantly keeps the presence of moisture and diesel vapors in the crankcase at a negative state, which in turn minimizes the dilution of the lubricant and significantly reduces oil consumption previously being pushed out of the breather tube in the form of vapors, and at the same time eliminating back pressure to the underside of the pistons, stabilizing the overall performance of the engine. One half pound PSI of constant crankcase back pressure is equal to 86# of drag at all the running time of engine.
In a gas application with the throttle moved to a loaded or more fully-opened position, the manifold vacuum pressure approaches atmosphere effective conditions. At the same time the amount of blow-by gases, vapors and solids emitted into the crankcase and related chambers is substantially increased.
Ergo the need for an efficient crankcase evaculating system capable of constantly: 1. volumetrically controlling the vacuum of the crankcase back pressure, 2. versus ambient atmospheric pressure, 3. intake manifold vacuum and 4. blown air pressure.
In the case of turbo-powered diesel engine power plants, when the engine is under full load the blower is pressurizing the air into the intake manifold. This is the substantial explanation of the difference between this process hereof and the known prior art--#1 In order to remove the so-called fumes from the crankcase ; #2 filtering them to a cleaner state of condition than originally used; #3 the compressor as is adopted in this process is to accommodate three requirements at the same time,that being:
1. evacuating the fumes from the crankcase
2. drawing them through an effective depth-type filtering system and
3. exceeding the air pressure that is being exerted in the intake manifold by the engine blower.
If such a condition is not maintained constantly, a back lash will take place on the evaculator process, that is why the metered pressure from the compressor into the intake manifold has to exceed that of the blower of the engine at all times, supplying additional air and clean atomized fuel to generate additional horse power.
The embodiment of the crankcase fumes treatment apparatus of the present invention envisions a dynamic depth-type filtering system which cleans fuel vapors, and moisture, also non-ferrous solids from the engine crankcase blow-by. The solids are trapped by the filter element which prevents them from reentry to the engine intake manifold in contrast to prior art 2. However, the fuel vapors contained in the blow-by are cleaned and reused by the engine to general horsepower. By extracting the solid contaminants, porous and nonporous particulate but reintroducing cleaned diesel vapors to engine, wear is reduced, horsepower is increased, and the useful life of crankcase lubricant is prolonged and consumption is reduced. Returning fuel vapors to the engine intake manifold increases engine horsepower performance and fuel efficiency dramatically.
The invention provides a crankcase fumes treatment apparatus having a crankcase vapors and solids trap communicably connected with an I.C. engine between the crankcase and the intake manifold which in use will pass the resulting vapors into the intake manifold of the connected engine.
The system offers suitable application in diesel-driven trucks, tractors and buses, diesel-driven marine vessels and industrial generators of all types. Such a system can be modified to work very satisfactorily on automotive applications.
SUMMARY OF THE INVENTION
The embodiment of the crankcase fumes treatment apparatus of the invention envisions a dynamic filtering system which cleans the fuel and the moisture and eliminates the solids from the engine crankcase blow-by. The solids are trapped by a filter system which prevents them from reentering the engine. However, fuel vapors contained in the blow-by are reused by the engine. By extracting the contaminants, such as ferrous particles, engine wear is reduced and the useful life of the crankcase oil is prolonged. Returning the fuel vapors to the engine manifold dramatically increases engine horsepower, performance and fuel efficiency.
The invention provides a crankcase fumes treatment apparatus having a crankcase vapors trap communicably connected with an I.C. engine between the crankcase and the intake manifold which in use will pass crankcase vapors into the crankcase vapors trap and therein separate liquid portions thereof from gaseous portions thereof and pass the resulting vapors into the intake manifold of the connected engine.
The system offers suitable applications in diesel-driven trucks, tractors and buses, diesel-driven marine vessels and industrial diesel generators of all types.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is an exploded schematic diagram showing the key components of the system; and
FIG. 2 is a sectional view through the secondary filter assembly of the invention showing its components in assembled position.
DESCRIPTION OF THE PREFERRED EMBODIMENT
FIG. 1 advantageously serves as a flow diagram of the ventilating system of the invention.
Directly connected to each rocker arm 2 is a rocker arm bonnet 4 which contains a sealed set of replaceable multi-stage filters 6, same representing a plurality of layers of filtering material arranged in the order of descending porosity to define a monolithic, layered porous structure. The layers of different permeabilities and porosities are formed by placing the layers of controlled retention characteristics across the interior diameter of rocker arm bonnet 4.
The rocker arm bonnet represents the primary filter stage.
The multilayered primary microfiltration medium consists of a series of filter elements each comprised of reticulated airfoam "honeycomb" material consisting of a three-dimensional network of interconnecting strands of a polyurethane resin. Each element abuts the next in face-to-face confrontation and is longitudinally aligned with the others. Each varies in porosity from a most coarse inboard layer 8 to a layer of finest porosity 12 as the outboard layer in the direction of airflow through the bonnet, with a layer of intermediate porosity 10 sandwiched between layers 8 and 12.
Filters 8, 10, and 12 are interengaged as by a spindle means 14 extendable through the bank of the filters of the set and having a finger engaging portion by which the filters may be removed unisonly from the bonnet for any replacement or cleaning purpose.
An apertured cover 16 is nestably receivable over the open top of rocker arm bonnet 4 to tightly enclose same.
The blow-by vapors are led into the rocker arm bonnet for the primary filtration.
A connecting conduit 60 leads from the bonnet interior and through its cover 16 to the lower extremity of a secondary subassembly now to be described.
The filtered blow-by vapors are passaged from the primary stage to the secondary stage 18 via conduit 60. The conduit extends through a suitable opening in the bottom wall of a lower housing half part or canister 64.
The secondary stage is termed an evaculator. Conduit 60 is provided with a plurality of equispaced raw vapor inlet ports 62. A magnetic disc 66 circumscribes conduit 60 and seats upon the inner wall of the bottom of lower housing half part 64. Inlet ports 62 are disposed upwardly of magnetic disc 66.
Spaced upwardly of magnetic disc 66 and also circumscribing conduit 60 is a baseplate baffle 68 having a lowermost radially extending circular portion upon which seats a filter gasket 70.
A plug 73 seals off the upper extremity of conduit 60 to influence the passage of the incoming fumes and vapors radially over the face of magnetic disc 66 and into the open space 74 between a filter cartridge 72 and lower housing half part 64.
As the vapors enter through the conduit, they are confronted by the baffle serving to direct the vapors over the magnetic disc which picks up the ferrous particles therein contained, with the non-ferrous particles and moisture being subsequently trapped by filter cartridge 72. That is, the ferrous particulates are captured by the magnetic system upon entry into the sealed secondary stage, while the non-ferrous abrasives continue on in a vacuum atmosphere only to be trapped by the filter cartridge.
Filter cartridge 72 seats upon gasket 70 whereby it is spaced upwardly of the bottom flooring or deck of the lower housing half part to define space 74.
An upper housing half part 76 mates with the lower housing half part 64 at the midsection of the housing, the two components being suitably sealed with an annular U-shaped locking ring 78.
Upwardly of conduit 60 and extending vertically through a provided central opening in filter 72 is a core tube 80 having an interior thread and into the lower end of which plug 73 is threadedly engaged and plug welded thereto.
With the upper extremity of core tube 80, a filter retainer 82 is threadedly engaged, same being sealed against the interior of the top wall of the upper housing half part by an O-ring seal 84, strategically positioned between filter retainer 82 and an outlet 86 extending through the top wall of and leading from the upper housing half part.
An annular filter element gasket 88 is interposed between filter retainer 82 and the top of filter 72 to insure against leakage of any of the vapors and fumes except by passage through the filter and core tube 80 and retainer 82 before exiting via the outlet port 86 as filtered vapors.
An O-ring seal 85, additional to O-ring seal 84, in the lower half of the canister aids to insure the prevention of the vapors from escaping secondary filtration.
A crankcase oil return port 92 is provided in the bottom wall of lower housing half part 64 to which a crankcase oil inlet 94 is threadedly connected.
An anti-syphon valve 96 is disposed outboard of crankcase oil inlet 94 and in which an upper float ball 98 and a connected anti-syphon ball 100 are disposed.
The buoyancy of the oil when present in the antisyphon valve 96 lifts the twin balls 98-100 from the seat of the lower float ball on the crankcase oil outlet port 102 so as to allow the return of the crankcase oil to the engine crankcase. This operation takes place only when excess blow-by in engine crankcase is above normal causing a high concentration of oil accumulation of oil in the lower half of the secondary housing.
The remaining filtered fuel and moisture vapors are exited from the secondary stage via outlet 86 and a threadedly connected conduit 100 to a tertiary filter subassembly, as shown in FIG. 1.
Conduit 100 leads into and through a wall 102 of a clear see-through tertiary stage filter housing 104 in which is disposed a filter element 106.
Within the housing and adjacent filter element 106 a free-spinning fan 108 is provided, same being operable rotatively by virtue of a series of small holes 110 in an activator plate 112, the plate 112 and fan 108 being mounted on a shaft 114.
The fan functions as an indicator of the airflow. When and if the fan slows down in its rotative motion, or ceases rotation, the delivered intelligence is to the effect that a change in filters is indicated.
A cover wall 118 permits the enclosing of the third stage filter at its opposite end.
The third stage assembly performs a pair of essential functions; it acts as a flow indicator filter to be sure, but more importantly, it serves as an indicator of the overall system performance.
The housing, being clear, it is possible to see into same to determine the activity of the free-spinning fan blade. Thus, the overall performance of the system can be assessed.
The color of the third stage filter unit is an indicator of the whole system performance. A discolored filter indicates the presence of varnish or soot and that the filter element should be replaced. The free-wheeling fan rate of turning indicates a direct ratio to the engine fume flow and is a good indicator of system performance. The fan free wheeling means that vapors are moving through the system, and the system is functioning satisfactorily.
The output of the third filter assembly connects via a conduit 120 to the vacuum side of a compressor 122 which provides a vacuum sufficient enough to draw the cleaned vapors through the system. The pressure side of the compressor connects via conduit 124 to the intake manifold 126 of the engine.
Thereby, the fuel being introduced from the crankcase, as so called blow-by, has been cleansed by the system and returned to the engine creating increased horsepower for use, thus, better fuel economy.
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A crankcase fumes treatment apparatus envisions a primary filtering system for extracting fuel, moisture and solids from the engine crankcase, the solids being mainly trapped by a filter element preventing reentry into the engine, with the fuel vapors and moisture being conducted returnably to the engine for increasing horsepower and a secondary filtering system for secondarily filtering the fuel vapors from solids before passage to the engine.
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RELATED APPLICATION
The inventors hereof claim priority under U.S. Provisional patent application Ser. No. 60/032,727, filed Dec. 14, 1996.
FIELD OF THE INVENTION
This invention relates generally to a spill-resistant lid for use with a beverage container, and, more particularly, to an improved spill-resistant lid for use with a hot beverage, like coffee, wherein condiments are commonly added. The present invention provides a spill-resistant lid having means for easy addition of condiments without the need to open or remove lid, and further provides a novel form of stirring rod for use with the spill-resistant lid.
BACKGROUND OF THE INVENTION
In recent years, the fast food service industry has experienced an explosion in growth. That growth has resulted in dramatically increased sales of take-out beverages. The industry has come to demand functional, convenient, inexpensive containers and lids for both hot and cold beverage service. Particularly relevant to the field of the present invention are lids required for use in hot beverage take-out service.
In order to supply such hot beverages to an increasingly mobile customer base, certain functional criteria must be considered in designing suitable hot beverage container lids. Successful designs have met the industry required criteria of being easily manufactured, being susceptible of compact storage for shipment and dispensing, and being inexpensive so as to be disposable following a one time use.
It has been observed, however, that certain other considerations have not been well met in the prior art. Specifically, on-the-go consumers are often concerned with the convenience, ease, and speed in adding condiments, such as sweeteners and creamers, to hot beverages such as coffee, tea, or the like. The industry and its consumers alike are concerned with ways to reduce or prevent the accidental injuries which often occur due to splashing or overturning of such hot beverages.
The design of such lids seemingly has been especially challenging, given that many hot beverages are served at drive-through windows. Wisely or not, consumers may attempt to add condiments to hot beverages while seated in a moving vehicle. Because contemporary hot beverage service lids provide limited access to the hot beverage for purposes of adding such condiments, consumers often remove the lid from the beverage container to add the desired condiments. It is often during this activity that injurious splashes or spills of the hot beverage occur.
Additionally, dripping of the hot beverage is a common experience. The source of such dripping is often attributable to insufficient sealing of the lid periphery against the rim of the cup. This is so because contemporary insulated paper cups are manufactured with a seam joining overlapping edges of the paper. This seam results in a step-type misalignment adjacent the surface of the cup. Because the rim of the cup is formed by rolling the upper edge thereof, the gap ultimately formed between the lid and the cup rim tends to increase. Depending upon the consumer's orientation of the cup when drinking, the resulting gap may result in dripping of the beverage from between the lid and the cup rim at the seam of the cup.
Recognizing this inconvenience, others have provided lid designs intended to increase the hoop strength of the lid. Examples of such designs may be found by referring to U.S. Pat. No. 5,460,286 to Rush et al. Such designs, even when effective, do not completely solve the problem so presented.
Further compounding the dripping problem, certain prior art lids remove the continuous seal between the cup and the lid adjacent the rim surface, as in those designs that utilize a "tear-back" tab portion of the cup lid. An example of such a design may be seen by referring to U.S. Pat. No. 4,738,373 to DeParales. The seal often is not reestablished well enough to prevent the hot beverage from leaking at the exposed junctures between the rim and the lid.
In addition, the "tear-back" tab portion of such a cup lid design may not stay firmly in its open position and can interfere with the consumer while drinking. Furthermore, the edges adjacent the "tear-back" tab portion which are left when the tear is effected can sometimes be sharp. These edges may feel uncomfortable to the consumer while drinking, and in some cases may cut the consumer's mouth.
Other inconveniences may be seen in referring to the prior art. Some lids, commonly referred to as "drink-through" cup lids, can be somewhat difficult for the consumer to drink from. The openings may be inconvenient, involving distortions of the lid from the user's mouth during drinking, as in U.S. Pat. No. 4,582,214 to Dart et al. Sometimes, the flow of the beverage allowed to pass through the openings may be substantially reduced, as in U.S. Pat. No. 4,898,299 to Herbst et al. The reduced beverage flow provided through some such lids may not be sufficient to satiate the consumer.
What is needed and apparently not heretofore available is a hot beverage cup lid which is effective in reducing the spills, splashes, and drips attendant to disposable hot beverage containers of the contemporary fast food service industry. The hot beverage cup lid should be effective in reducing such spills, splashes, and drips, without significantly impeding such flow of the beverage as the consumer may desire. Such a hot beverage cup lid should empty completely. Such a hot beverage cup lid, further, be susceptible of providing the consumer with the ability to safely and conveniently add desired condiments to a hot beverage without necessitating removal of the lid. Additionally, such a hot beverage cup lid should be comfortable to the consumer during use, attractive in design, inexpensive to manufacture, convenient to transport and store, and disposable.
It is the recognition of defects observed within the prior art hot beverage cup lids, combined with the recognition of those needs recited hereinabove, which has formed the objects and the basis for the present invention. It is, therefore, to the provision of such a hot beverage cup lid that the present invention is primarily directed.
SUMMARY OF THE INVENTION
The present invention comprises a hot beverage cup lid of the "drinkthrough" type, having a drink-through opening in the form of an arcuately shaped spout. The spout is located adjacent the upper peripheral rim of the hot beverage cup lid. The internal, substantially continuous peripheral edges of the drink-through opening depend inwardly toward the cup, so that fluid traveling adjacent the walls of the cup lid, as often occurs during vibration or shaking of the cup, is redirected and channeled down and away from the drink opening. The internal, substantially continuous peripheral edges of the drink-through opening allow the drink-through opening to be larger than prior art flat edge openings, so that beverage flow to the consumer is improved.
A condiment funnel is located at, or near, the center of the lid. A condiment funnel opening is provided which serves to channel excess beverage back into the cup, and through which condiments, such as cream or sweetener, may be poured into the cup. The funnel opening also acts to equalize the internal pressure within the cup when the consumer drinks through the cup lid. The funnel opening further acts to vent the cup lid of steam.
Also provided is a stirring rod with a hemispherically shaped flange or ball disposed near the upper portion of the rod. The hemispherical flange or ball rests in the condiment funnel opening and aids the consumer in stirring the beverage. The hemispherical flange also helps thermally seal the cup lid to decrease heat loss from the hot beverage. Optionally, the hemispherical flange or ball may contain a venting means, preferably in the form of a slit, should a higher degree of venting be required. Such an optional venting means further allows any excess beverage collected in the central funnel cavity, which otherwise would be trapped by the hemispherical flange of the stirring rod, to drain back into the container.
An aligning graphic, or indicia, is provided directly opposite the drink-through opening. When this indicia is disposed adjacent to the seam in paper-type cups, the resulting alignment of the cup lid with respect to the seam of the paper cup acts to reduce the drips due to the gap formed between the cup lip and the cup lid.
The usefulness of the present invention is enhanced by the wide variety and range of optional features which may be associated with it. Such optional features may include, but are not limited to: varied color; and, raised or bas-relief surface features of a variety of sizes, shapes, designs, patterns, characters, lettering, or any combination thereof.
Thus, one advantage of the hot beverage cup lid of the present invention is that it is effective in reducing the spills, splashes, and drips attendant to disposable hot beverage containers of the contemporary fast food service industry by providing a unique drink-through opening that resists accidental spilling, splashing, and dripping of a hot beverage. This is so because the present invention provides a contoured drinking spout, and further having internal, substantially continuous peripheral edges substantially surrounding the drink-through opening. These features, in combination, tend to impede travel of the hot beverage along the walls of the lid around the drink-through opening and to further redirect the beverage back into the container.
Another advantage of the hot beverage cup lid of the present invention is that it is effective in reducing spills, splashes, and drips, without significantly impeding such flow of the beverage as the consumer may desire. This is so because the internal, substantially continuous peripheral edges of the drink-through opening allow the drink-through opening to be larger than prior art flat edge openings, so that beverage flow to the consumer is improved.
Another advantage of the hot beverage cup lid of the present invention is that, in an optional configuration, it allows the consumer to completely empty the beverage container during use by providing at least one hole passing between the rim of the drink-through opening and the peripheral wall of the lid.
Another advantage of the hot beverage cup lid of the present invention is that it optionally may be provided with an aligning graphic, or indicia, that resists dripping from cups of the type which are manufactured with overlapping edges. This is so because the indicia is oriented in a position approximately 180° about the periphery of the lid with respect to the drink-through opening. When the indicia of the hot beverage cup lid is aligned adjacent to the overlapping edge, the seam, including the attendant gap formed between the lid and the cup rim, is opposite the direction of pouring of the hot beverage. Because little, if any, of the beverage is allowed to come into contact with the cup rim adjacent the gap, dripping through the gap is thereby minimized.
Another advantage of the hot beverage cup lid of the present invention is that it provides the consumer with the ability to safely and conveniently add desired condiments to a hot beverage without necessitating removal of the lid. This is so because the lid is provided with a central funnel, the funnel having an upper rim sufficiently large to intercept and contain a reasonable quantity of condiments being poured by the consumer thereinto. The funnel acts to direct the condiments towards a central opening which is sufficiently large to pass the condiments unobstructedly, and without clogging, into the beverage container. The funnel further serves to channel back into the container any beverage which may have passed through the funnel opening.
A further advantage of the present invention is that it provides a unique stirring rod for the hot beverage cup lid of the present invention. The stirring rod is provided with a ball or a hemispherical flange. The hemispherical flange is located along the axis of the stirring rod conveniently to serve its purpose, considering the depth of the cup. When the stirring rod is inserted through the central funnel opening, the hemispherical flange acts as a pivotal bearing surface to facilitate stirring of the beverage. When the stirring rod of the present invention is situated as described, its hemispherical flange further acts as a full or partial plug to resist splashing or spilling of the beverage through the central funnel opening, and to restrict the funnel opening against thermal losses. The hemispherical flange optionally may be provided with a venting means, preferably in the form of a slit. The venting means allows any excess beverage collected in the central funnel cavity, which otherwise would be trapped by the hemispherical flange of the stirring rod, to drain back into the container.
Yet another advantage of the present invention is that it is comfortable to the consumer during use, attractive in design, inexpensive to manufacture, convenient to transport and store, and disposable following its use.
Other objectives, features, and advantages of the present invention will become more fully apparent by reference to the following detailed description of the preferred embodiment, the appended claims, and the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
The present invention will be better understood by reading the Detailed Description of the Preferred Embodiment with reference to the accompanying drawing figures, in which like reference numerals denote similar structure and refer to like elements throughout, and in which:
FIG. 1 is a perspective view of the typical cup lid of the present invention showing the central condiment funnel opening, raised drink-through opening, and an alignment indicia disposed adjacent to a paper cup seam;
FIG. 2 is a top view of the present invention shown in FIG. 1;
FIG. 3 is a cross-sectional view of the present invention shown in FIG. 1, taken along line I--I, showing the inwardly curved peripheral edges of the drink-through opening and the function of the ball or hemispherical flange mechanism of the stirring rod of the present invention;
FIG. 4 is a perspective view of the upper third of the stirring rod of the present invention showing a hemispherical flange with a slit for venting of the condiment opening.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
In describing the preferred embodiments of the present invention illustrated in the Figures, specific terminology is employed for the sake of clarity. The invention, however, is not intended to be limited to the specific terminology so selected, and it is to be understood that each specific element includes all technical equivalents which operate in a similar manner to accomplish a similar purpose.
Referring now to the drawing Figures, a preferred embodiment of the present invention is described in detail. Shown in FIGS. 1 through 3 is a drink-through cup lid (10) of the present invention. The cup lid (10) may be removably affixed to a disposable cup (12) well known in the art. Although cup (12) may be fabricated from any of a variety of popular materials, like polystyrene, coated or impregnated papers, and the like, the cup (12) shown in FIG. 1 is fabricated of treated paper. Cup (12) has a seam (14) formed during the manufacturing process by overlapping and sealing the paper edges. As best seen with reference to FIG. 3, cup (12) has a rolled lip (16) formed adjacent its open end (18).
The cup lid (10) includes at least three distinctive features. The first distinctive feature is a contoured spout (20) having at its top surface (22) a drink-through opening (24) disposed about the centerline of the spout (20). The contoured spout (20) is disposed adjacent the periphery of lid (10) and culminates in a substantially flat surface (22) disposed somewhat higher than the upper surface (27) of lid (10). The substantially flat surface (22) of spout (20) may be slightly angled, or tapered, toward the periphery of the lid (10) in order to more comfortably accommodate the consumer's mouth and to aid in directing the flow of the beverage. In the preferred embodiment of the present invention, the substantially flat surface (22) of spout (20) is disposed approximately one-fourth of an inch (1/4") higher than the upper surface (27) of the lid (10), although it will be appreciated that this dimension may be adjusted to accommodate the proportions of a particular size of lid.
As can best be seen with reference to FIGS. 1 and 2, the contour of the spout (20) is such that an inwardly curved depression (28) is formed relative to the upper surface (27) of the lid (10). The advantage of the spout (20) formed in this manner is that the consumer's mouth may comfortably be disposed about spout (20) while drinking, whereby air is effectively sealed out.
As can best be seen with reference to FIG. 3, the drink-through opening (24) is formed with an internal, substantially continuous, downwardly depending surface (26). The advantage of the cup lid (10) of the present invention formed in this manner is that the internal, substantially continuous peripheral edges (26) of the drink-through opening (24) allow the drink-through opening (24) to be larger than prior art flat edge openings, so that beverage flow to the consumer is improved. The contoured spout (20), in combination with the internal, substantially continuous peripheral edges (26) of the drink-through opening (24), tend to impede travel of the hot beverage along the walls of the lid around the drink-through opening (24) and to further redirect the beverage back into the cup (12), as described more fully below.
As can be seen in FIG. 3, the internal, substantially continuous peripheral edges (26) about the drink-through opening (24) serve to help prevent the beverage from accidentally spilling through the drink-through opening (24). It has been observed that when a beverage is going to spill, most of the fluid tends to travel along the surface of cup (12) and lid (10). Unless the cup (12) is accidentally turned at an extreme angle, or upside-down, it is rare for the beverage to "slosh" directly upwards through the drink-opening (24) without contacting the internal surface of the cup (12) or lid (20). When the beverage does contact the surface of the cup (12) or lid (10), surface tension tends to keep it in contact therewith. When the beverage so traveling meets the peripheral edges (26) of the drink-opening (24), it is redirected back into cup (12). During normal drinking these peripheral edges (26) do not interfere with consumption of the beverage.
In an optional configuration, best seen by reference to FIG. 2, the lid (10) of the present invention allows the consumer to completely empty the beverage container during use by providing at least one small hole (30) passing between the rim of the drink-through opening (24) and the peripheral wall of the lid (10).
The second distinctive feature is a condiment funnel (32) formed substantially about the center of the lid (20). As can best be seen with reference to FIG. 3, the condiment funnel (32) depends downwardly from the upper surface (27) of the lid (10) toward the center of cup (12). The condiment funnel (32) concludes in a condiment funnel opening (34) disposed about the center of the lid (20).
In the preferred embodiment of the present invention, the diameter of the condiment funnel (32) adjacent the upper surface (27) of the lid (10) is approximately one inch (1"), and the diameter of the condiment funnel opening (34) is approximately three-sixteenths of an inch (3/16"), although it will be appreciated that these dimensions may be adjusted to accommodate the proportions of a particular size of lid and stirring implement.
The advantage of the condiment funnel (32) of the present invention formed in this manner is that it provides the consumer with the ability to safely and conveniently add desired condiments to a hot beverage without necessitating removal of the lid (10). This is so because condiment funnel (32) has an upper rim sufficiently large to intercept and contain a reasonable quantity of condiments being poured by the consumer thereinto. The funnel acts to direct the condiments towards the central funnel opening (34) which is sufficiently large to pass the condiments unobstructedly, and without clogging, into the cup (12). The condiment funnel (32) further serves to channel back into the cup (12) any beverage which may have passed through the condiment funnel opening (34).
The condiment funnel (32) serves several purposes. As can be seen in FIG. 3, the condiment funnel (32) allows a consumer to add condiments such as cream or sugar directly to a beverage while the cup lid (10) is attached to the cup (12). It also functions as a vent opening while the consumer is drinking, and it allows the use of a stirring rod (36). For the reasons described more fully above, it is rare for beverage to "slosh" directly upwards through the condiment funnel opening (34) at or near the center of the lid (10); therefore, the condiment funnel opening (34) can be large enough to accept condiments and a stirring rod (36).
Other cup lids only provide small diameter holes, or "pin-holes," to serve as vent holes or drain holes. These small openings often are not adequate and can serve to make the beverage pour out in an uneven flow. In other cases, these small openings may allow the beverage to pool in the cup lid because they are too small to return the beverage to the cup. This deficiency sometimes may result in the beverage spilling onto the consumer. As can be seen in FIGS. 1 and 2, the condiment funnel opening (34) of the present invention also serves to collect runoff beverage that may be left over from a drink, and to redirect it into the cup (12).
In addition, and with reference to FIG. 3, the condiment funnel (32) allows the consumer to keep his or her head level while drinking. This is so because, as the consumer drinks, the condiment funnel (32) allows the consumer's nose to protrude into and below the top of the lid (10). Prior-art devices disadvantageously require a consumer to tilt his or her head in order to drink the beverage when it drops below a certain level. Thus, the condiment funnel (32) so provided by the present invention is particularly useful in situations where the consumer needs to see where he or she is driving or walking, yet would like to drink at the same time.
The third distinctive feature is an alignment graphic or indicia (38). As best seen with reference to FIG. 1, the alignment indicia (38) is oriented in a position approximately 180° about the periphery of the lid with respect to the center of the drink-through opening (24). When the indicia (38) of the hot beverage cup lid (10) is aligned adjacent to the overlapping seam (14), the attendant gap formed between the lid (10) and the cup rim (18) is opposite the direction of pouring of the hot beverage. Thus, during normal use, the beverage will always be at a level below the gap. Because little, if any, of the beverage is allowed to come into contact with the cup rim (18) adjacent the gap, dripping through the gap is thereby minimized. It is contemplated that a manufacturer might also provide a similar alignment indicia adjacent the cup seam (14) to help users properly align the indicia (38) along the seam (14).
As best seen with reference to FIGS. 3 and 4, the preferred embodiment includes a stirring rod (36) having a first end (40) for grasping between the consumer's fingers. The stirring rod (36) tapers toward a second end (42) which is widened into a shape conducive to efficient stirring.
Stirring rod (36) is provided with a ball or a hemispherical flange (42). The hemispherical flange (44) is located along the axis of the stirring rod (36) conveniently to serve its purpose, considering the depth of the cup (12), but is typically approximately one-third of the length of the stirring rod (36) from the first end (40). When the stirring rod (36) is inserted through the central funnel opening (34), the hemispherical flange (44) acts as a pivotal bearing surface to facilitate stirring of the beverage. When the stirring rod (36) of the present invention is situated as described, its hemispherical flange (44) further acts as a full or partial plug to resist splashing or spilling of the beverage through the central funnel opening (34), and to restrict the funnel opening (34) against thermal losses.
The hemispherical flange (44) optionally may be provided with a venting means, preferably in the form of a slit (46). The venting means (46) allows any excess beverage collected in the central condiment funnel cavity, which otherwise would be trapped by the hemispherical flange (44) of the stirring rod (38), to drain back into the cup (12).
It will be appreciated that the cup lid (10) of the present invention may be provided with any form of design (48) conducive to the purposes of the merchant establishment. Such design (48) may, for example, take the form of a warning label or a trademark designation. Other optional features, including, but not limited to, aesthetically pleasing coloration, may be provided in conjunction with the present invention without departing from the scope of the invention.
Having thus described exemplary embodiments of the present invention, it should be noted by those skilled in the art that the within disclosures are exemplary only, and that various other alternatives, adaptations, and modifications may be made within the scope of the present invention. Accordingly, the present invention is not limited to the specific embodiments as illustrated herein, but is limited only by the following claims.
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This patent discloses a detachable hot beverage cup lid. There is provided a spill resistant feature within the drink-through opening, a condiment funnel, an alignment indicia opposite the drink-through opening, and a novel stirring rod.
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CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] The present application claims priority to U.S. Provisional Patent Application Ser. No. 60/888,841, filed Feb. 8, 2007, the entire disclosure of which is incorporated by reference herein.
BACKGROUND
[0002] 1. Field of the Invention
[0003] The present invention relates to the field of joint replacement. Specifically, the present invention relates to a joint prosthesis for proximal interphalangeal joints.
[0004] 2. Description of the Related Art
[0005] The replacement of damaged or diseased joints in the human body has been known for some time. Devices utilized to replace natural joint structures generally mimic natural movement of the joint. In addition, such devices are often configured to provide for a natural “at rest” position similar to that of the natural joint.
[0006] Known proximal interphalangeal joint prosthetics typically employ two stems or arms with an intermediate pivoting structure. In some devices, the entire prosthetic is manufactured from a single elastomer material or from metal alloy.
SUMMARY
[0007] The present invention relates to a prosthetic used to replace a damaged joint, such as a pivotal interphalangeal joint, for example. The prosthetic may include a body portion and an outer weave portion. The body portion may include an intermediate portion and a pair of stems connected to, and extending from, the intermediate portion.
[0008] The body portion may be formed from a hydrogel material, which may expand upon absorption of water. In addition, the outer weave portion may include a plurality of layers including a polymer layer and a metal layer. The polymer layer may be located intermediate the metal layer.
[0009] The intermediate portion may include a recess, which may be formed in the palmar side of the intermediate portion.
[0010] In one form thereof, the present invention provides a prosthetic used to replace a damaged joint including a body portion including an intermediate portion and a pair of stems connected to the intermediate portion; and an outer weave encompassing the body portion.
[0011] In another form, the present invention provides a prosthetic used to replace a damaged joint including a body portion including an intermediate portion and a pair of stems connected to the intermediate portion; wherein the body portion is formed from hydrogel.
[0012] In another form, the present invention provides a prosthetic used to replace a damaged joint including a body portion formed from a hydrogel material and including a pair of interconnected stems; and an outer weave at least partially encompassing at least one of the stems.
BRIEF DESCRIPTION OF THE DRAWINGS
[0013] The above-mentioned and other features and advantages of this invention, and the manner of attaining them, will become more apparent and the invention itself will be better understood by reference to the following description of an embodiment of the invention taken in conjunction with the accompanying drawings, wherein:
[0014] FIG. 1 is a perspective view of a prosthetic device embodying the present invention;
[0015] FIG. 2 is a perspective view of the prosthetic device of FIG. 1 with a portion of the outer weave omitted for illustrative purposes;
[0016] FIG. 3 is a side view of a body portion of the prosthetic device, illustrating exemplary ranges of motion thereof from a substantially non-flexed or neutral position shown in solid lines;
[0017] FIG. 4 is a side view of the body portion depicted in FIG. 3 in a flexed position; and
[0018] FIGS. 5-7 are side views of a finger illustrating an exemplary surgical method of implanting the prosthetic of FIG. 1 .
[0019] Corresponding reference characters indicate corresponding parts throughout the several views. The exemplification set out herein illustrates one preferred embodiment of the invention, in one form, and such exemplification is not to be construed as limiting the scope of the invention in any manner.
DETAILED DESCRIPTION
[0020] FIGS. 1 and 2 depict different views of a joint prosthetic, generally indicated by numeral 2 , representing an exemplary embodiment of the present invention. Prosthetic 2 includes a body portion 4 and a cover or weave portion 6 encompassing body portion 4 . In FIG. 2 , a portion of weave portion 6 has been omitted in order to illustrate body portion 4 with respect to weave portion 6 . The depicted embodiment of prosthetic 2 is configured to be utilized in the proximal interphalangeal (PIP) joint of a human finger 30 , as shown in FIG. 7 .
[0021] With reference to FIGS. 3 and 4 , body portion 4 includes a first stem 8 , a second stem 10 and an intermediate portion 12 . Stems 8 , 10 and the intermediate portion 12 may be formed with a unitary one-piece construction. In the present embodiment, body portion 4 may be formed from any suitable hydrogel material.
[0022] A hydrogel is a network of polymer chains that are water-soluble but made insoluble through physical and/or chemical crosslinks. These materials are sometimes found as a colloidal gel in which water is the dispersion medium. Hydrogels are generally formed from natural or synthetic polymers. Hydrogels may be classified as “superabsorbent” and may contain over 99% water, by weight. In addition, hydrogels may have the ability to swell due to water absorption. Hydrogels may also possess a degree of flexibility very similar to natural tissue, due to their significant water content. Suitable hydrogels include hyaluronic acid, polypropylene fumarate, and Poly(ethylene glycol)-co-polylactide, methyl cellulose, and carboxy methyl cellulose.
[0023] In general, the stems 8 , 10 are sized and configured to be received within intramedullary recesses or bores of adjacent bones. For example, in the exemplary implantation depicted in FIG. 7 , the first stem 8 is sized and configured to be received into a bore 42 of the middle phalanges 34 of the finger 30 . Similarly, the second stem 10 is sized and configured to be received into a bore 44 of the proximal phalanges 36 of finger 30 .
[0024] Intermediate portion 12 is configured to provide flexion motion between the first stem 8 and the second stem 10 . With reference again to FIGS. 1 through 4 , intermediate portion 12 includes a first surface 14 and a second surface 16 . In the depicted embodiment, first surface 14 is substantially planar while second surface 16 includes a concave area or recess generally indicated by numeral 18 .
[0025] In the present embodiment, the concave area 18 is located on the palmar side of the prosthetic 2 and includes a bending portion defined by arcuate surface 20 . Arcuate surface 20 extends medial-laterally.
[0026] Second surface 16 also includes two flanges 22 , 24 . The flanges extend in the palmar direction on opposite sides of arcuate surface 20 . As depicted in the figures, the flanges 22 , 24 travel toward each other during flexion movement. The flanges 22 , 24 are configured to engage during flexion movement in order to inhibit over-flexion, as shown in FIG. 4 .
[0027] For illustrative purposes, the first stem 8 defines a central axis, generally indicated by numeral 26 , which extends longitudinally through the center of first stem 8 . Similarly, second stem 10 defines a central axis, generally indicated by numeral 28 , which extends longitudinally through the center of second stem 10 . When in a neutral or rest position depicted in solid lines in FIG. 3 , the first stem 8 extends at a slight angle with respect to the second stem 10 . Accordingly, in the rest position, the first stem 8 and the second stem 10 do not extend along a straight line, rather, axis 26 and axis 28 are positioned at an angle of approximately 15° with respect to each other when the prosthetic 2 is “at rest” or under no significant external forces, or stress. The at rest angle may be any angle suitable for a given usage of prosthetic 2 .
[0028] With reference specifically to FIGS. 3 and 4 , the intermediate portion 12 allows for infinite flexion motion to any position intermediate the positions depicted in phantom in FIG. 3 . As shown in FIG. 3 , in the depicted embodiment, intermediate portion 12 may allow for infinite flexing between about 0° and about 108° as defined by the axes 26 , 28 . FIG. 4 depicts the prosthetic 2 in a flexion position.
[0029] The slight angle defined by the axes 26 , 28 generally conforms to the naturally-biased position of the phalanges 34 , 36 , which generally extend at angles ranging from about 10° to about 50°, depending on the location of the joint. For example, the natural bias of the PIP in a typical index finger differs from the natural bias of a PIP in a ring finger. Those possessing ordinary skill in the art may readily determine a suitable angle to accommodate the natural bias of any extremity at rest.
[0030] It should be noted that the normally biased attitude of the two stems 8 , 10 is at an angle that accommodates the natural bias in the joints. Thus, the bias of the prosthetic 2 will not tend to force a finger in which the prosthetic 2 is implanted into an unnatural straight position or an unnatural overly bent position.
[0031] With reference still to FIGS. 1 and 2 , in the present embodiment, weave portion 6 may comprise multiple braided layers of suitable material. For example, in the embodiment depicted in FIG. 2 , weave portion 6 may include an outer metal layer 7 and a polymer 9 . The polymer layer 9 may be arranged intermediate the hydrogel surface of body 4 and the outer metal layer 7 of the weave 6 . The inclusion of the polymer layer 9 of the weave 6 reduces the potential for the outer metal layer 7 to damage the hydrogel surface of body 4 . If necessary, additional layers of material may be utilized intermediate the hydrogel surface of body portion 4 and the outer metal layer 7 of weave portion 6 to further reduce the potential for damage to body portion 4 .
[0032] Weave portion 6 may be formed in any suitable manner, such as by way of braiding, for example, and may be interconnected to body portion 4 in any known manner. For example, weave portion 6 may be woven around body portion 4 by way of insert braiding. Also, weave portion 6 may be woven in any suitable manner that restricts the motion of the prosthetic 2 in order to ensure the prosthetic does not flex in a direction incompatible with the normal direction of flexion of a joint. In addition, the formation of the weave portion 6 may constrain the motion of the prosthetic to that of a normal joint.
[0033] FIGS. 5 through 7 depict the various stages of an exemplary surgical method for implanting prosthetic 2 in a PIP joint. FIG. 5 depicts a finger 30 including distal phalanges 32 , middle phalanges 34 , proximal phalanges 36 , and a natural PIP joint 38 . In an exemplary method of implantation of prosthetic 2 , a gradual curving dorsal incision may be made over the PIP joint 38 . Through suitable dissection, skin flaps (not shown) may be gently elevated in order to expose a portion of the extensor tendon mechanism (not shown). An additional incision may be made intermediate the central tendon (not shown) and the lateral band (not shown) on the opposite side of finger 30 . The dorsal capsule (not shown) may then be incised in order to expose the PIP joint 38 .
[0034] After suitable incision and preparation has been accomplished, a surgeon may remove the natural PIP joint 38 . In particular, the central tendon (not shown) may be protected with retractors (not shown) while a micro-oscillating saw (not shown) is used to resects the proximal phalanges 36 at a position that results in the removal of the PIP joint 38 . A rongeur (not shown) may also be utilized to remove spurs from the middle phalanges 36 thereby flattening out the middle phalanges.
[0035] As depicted in FIG. 6 , the removal of the PIP joint 38 results in void 40 having a size predetermined to receive prosthetic 2 . The surgeon may remove additional bone structure on the proximal phalanges 36 and the middle phalanges 34 , as necessary, such that void 40 is large enough to receive the intermediate member 12 of the prosthetic 2 .
[0036] The surgeon may then create a start hole (not shown) in the exposed intrameduallary tissue of the remainder of the middle phalanges 34 using a known instrument (not shown) such as a reamer or a sharp awl. The surgeon thereafter removes the intrameduallary tissue in order to create a bore 42 in the middle phalanges 34 configured to receive first stem 8 of prosthetic 2 . The surgeon may employ a series of sequentially sized broaches (not shown) with the final size corresponding to that of first stem 8 . The surgeon may prepare the proximal phalanges 36 in a similar manner thereby resulting in bore 44 .
[0037] The surgeon may optionally attempt a trial fit of the prosthetic 2 . The trial fit may result in additional sizing or shaping of the bores 42 , 44 . In addition, the trial fit may determine if additional portions of the proximal phalanges 36 or the middle phalanges 34 should be removed. Furthermore, the trial fit may be used to determine if a different sized prosthetic 2 is required. A correctly sized prosthetic 2 should seal well against the middle phalanges 34 and the proximal phalanges 36 and be stable.
[0038] The surgeon may then insert the prosthetic 2 and attempt flexion and extension movement on the finger 30 in order to determine if the movement falls within an acceptable range of motion, such that flexion and extension occurs relatively uninhibited over a predetermined range of motion. Those with ordinary skill in the art may determine the acceptable threshold amount of uninhibited range of motion for a given patient. In order to insert the component, the surgeon may insert first stem 8 into bore 42 of the middle phalanges 34 . Second stem 10 may then be inserted into bore 44 of the proximal phalanges 36 , as depicted in FIG. 7 .
[0039] Once the prosthetic 2 has been implanted, the surgeon may close the site using techniques known in the art. Generally, the capsule may be sutured, if necessary. In addition, the exterior mechanism may also be sutured.
[0040] After implantation, the hydrogel composition of the stems 8 , 10 allows the stems 8 , 10 to swell within the finger 30 as the prosthetic absorbs water. Accordingly, less reaming of the phalanges 34 , 36 is necessary since the stems 8 , 10 will initially be relatively short but grow in size and extend into the bores 42 , 44 of the phalanges 34 , 36 as water is absorbed by the prosthetic to provide initial fixation. In addition, the outer layer of metal comprising the weave portion 6 represents a substantially open cell or porous structure promoting osseointegration into which the bone of the phalanges 34 , 36 may grow into after the implant has been implanted for long-term fixation. It should be noted that the expansion of stems 8 , 10 due to the absorption of water will force the outer metal layer of weave portion 6 into contact with the bone of the phalanges 34 , 36 , thereby aiding in the interconnection of the growing bone and the weave 6 . Furthermore, the general properties of the hydrogel comprising body portion 4 functions to cushion the joint in which the prosthetic 2 is inserted.
[0041] While this invention has been described as having exemplary designs, the present invention may be further modified within the spirit and scope of the disclosure. This application is therefore intended to cover any variations, uses, or adaptations of the invention using its general principles. Further, this application is intended to cover such departures from the present disclosure as come within known or customary practice in the art to which this invention pertains.
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A prosthetic for use in an interphalangeal joint including a body portion and a weave portion. The body portion may be manufactured from a hydrogel material. The body portion includes an pair of stems and an intermediate section located in between the two stems. The intermediate section includes a recess allowing for flexing of the body portion.
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CROSS-REFERENCE TO RELATED APPLICATIONS
This application is a continuation of Ser. No. 09/607,920, filed Jun. 30, 2000 now abandoned, and entitled RADIO PROPAGATION MODEL CALIBRATION SOFTWARE.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The invention relates to software, systems and methods used to determine the coverage of cell sites for cellular phones and, more particularly, to a method and system used to generate and calibrate site specific coverage models.
2. Description of the Related Technology
Cellular radio systems provide wireless connections between portable cellular telephones and a cellular radio infrastructure of cell sites and interconnecting network facilities. In an ideal environment with uniform frequency usage and cell coverage, cell sites might be arranged in a honeycomb-like pattern to maximize individual cell utilization. However, such an ideal arrangement is seldom, if ever, applicable in real world environments. Instead, geographic coverage of cell sites is dictated by many factors, including density of users, topology, interference, and other factors. Thus, simulation systems are used to model cell sites and cellular networks as part of cellular network design, upgrade and maintenance procedures. However, because of the variability between and among even similar locations, models must be calibrated to conform to the actual planned cell site environment.
Hoque, U.S. Pat. No. 5,410,736, entitled “Method For Determining Radio Transmitter Sites With Signals That May Potentially Interfere With An Intended Signal At A Radio Receiver Site”, issued Apr. 25, 1995 describing a method for conducting radio transmission systems interference studies by modifying a conventional two-step process of conducting a simple analysis on all potentially interfering systems to eliminate those clearly not causing interference into radio receiver under study, and then conducting a detailed analysis on the remaining systems. The disclosure describes replacing the first step with a method using pre-calculated average terrain elevations over a geographic block for determining whether the loss should be calculated using a smooth terrain calculation method with a simulated single knife edge diffraction obstacle in the path, or a rough terrain calculation method that substitutes a pre-calculated block roughness factor in place of the path roughness factor. The disclosure also describes substituting a new effective antenna height for the actual antenna height in propagation loss calculations.
U.S. Pat. No. 5,787,350 to van der Vorm, et al. entitled “Method for Determining Base Station Locations, and Device for Applying the Method” issued Jul. 28, 1998 describing automated determination of base station locations by calculating, for each location, a number which is a function of a parameter associated with that location (telephone traffic, field strength, motor traffic) and of parameters belonging to adjoining locations, and by assigning a base station to the location having the most extreme number. Then the parameter associated with that location, and the parameters associated with adjoining locations are each adjusted on the basis of an adjustment function associated with the base station, and new numbers are calculated which are a function of the new, adjusted parameters, etc.
Brockel, et al., U.S. Pat. No. 5,794,128, entitled “Apparatus and Processes For Realistic Simulation Of Wireless Information Transport Systems” issued Aug. 11, 1998 describing models and processes for simulating wireless information transport systems using time and frequency dynamic effects on stationary and mobile communications systems. A modeling system includes a data entry module, a communications traffic selection module, a driver database, and voice and data input modules furnishing a simulation input to a network simulation module. The network simulation module has communications “realism” effects, a it distributed interactive simulation structure, a channel error-burst model to transmit random errors, and a multipath modeling module to integrate deterministic and stochastic effects. The multipath modeling module, having a digital radio model and a Terrain-Integrated Rough Earth Model, influences the simulation inputs forming a multipath output, which is adjusted by voice and data inputs to provide a real-time simulation output signal to a module displaying the simulated communications network and link connectivity.
Lee, et al., U.S. Pat. No. 6,032,105 entitled “Computer-Implemented Microcell Prediction Modeling with Terrain Enhancement” issued Feb. 29, 2000 describing a computer-implemented modeling tool for cellular telephone systems that predicts signal strength by considering the effects of terrain and man-made structures on transmitted signals. The modeling tool gives predictions under line of sight conditions, when obstructions occur due to terrain contours, and when mobile or transmitter antennas are blocked by buildings or other structures.
As described in these four disclosures, all of which are incorporated herein by reference in their entirety, various methods and techniques are used to model cellular telephone system operation including predicting coverage of each of the radio transceiver cell sites forming the mosaic network of microwave frequency radio stations communicating with the portable cellular telephones. Such models are critical because, although the cellular service provider measures the signal strength directly, individual measurements would not enable the provider to know the signal strength at every point within the cell to confirm cell coverage and identify and address problem locations.
Unlike theoretical free space propagation, actual signal depends on local up environmental characteristics within the cell. Cellular service providers use models to estimate the signal strength at any point within the cell. These models predict system coverage and potential interference at points within the cell by determining the signal path loss from the cell site to the specific point within the cell. Cellular service providers use this information for a variety of purposes including initial cell site location, placement of addition cell sites, frequency planning, and to determine the power required at specific sites.
Many factors are included in the determination of signal path loss to a specific point within the cell. Three main concerns are transmission, environment and losses due to multiple signal paths (multi-path) causing self-destructive interference. Transmission modeling is used to predict the power available from the antenna at locations within the intended cell site coverage space. In general, the amount of power at the output of the antenna is a function of the amount of power provided to the antenna and the antenna radio frequency radiation pattern. These two factors, power output and antenna gain, sometimes expressed as Effective Radiated Power (ERP), are crucial in determining the signal strength along various radials from the antenna.
Methods for calculating ideal transmission loss are well known. Transmitter power output, transmission cable loss, antenna gain, free space propagation loss, antenna and receiver gain can all be calculated and used to predict a theoretical, best case cell coverage.
Environment modeling involves determining the effects of the terrain features between the cell site and the specific position within the cell. (Contrary to its designation, environmental modeling at typical cellular radio operating frequencies does not normally encompass weather conditions such as humidity, precipitation, temperature, etc.) While signal path losses attributable to dispersion increase as the inverse square of the distance from the cell site increases, environment factors can greatly affect these losses. Modeling of the environment includes the signal reduction due to the distance from the cell site as well as defraction losses caused by buildings or other terrain features between the cell site and the specific point within the cell. Furthermore, since radio propagation conditions vary significantly in typical operating environments, signal path loss models normally account for the statistical variability of the received signal (which is defined as environmental shadowing) by incorporating suitable power margins (offsets) for the purpose of system planning.
A third type of modeling predicts the effects of multiple signal paths and resultant destructive interference at the received location, namely multi-path fading. Multi-path fading results from multiple paths taken by a signal from the cell site to a specific point within a cell. When two or more signal components arrive at a particular reception point in space after traveling different distances, the resultant signals may no longer be in phase. Thus, when these signals are combined, the difference in the phase shifts may combine destructively and produce a degraded sum signal at the specific point. Unfortunately, precise modeling of destructive interference is very difficult because of the number of variables involved and the relatively short 15.1 to 31.2 centimeter wavelengths used by the cellular services. Accordingly, for system planning purposes, power margins (offsets) are normally included in path loss predictions to account for the effects of multi-path fading.
To determine the signal path loss from the cell site to a specific point within the cell, signal path loss equations used by cellular service providers account for transmission and environment losses, and include power margins to account for multi-path fading and environmental shadowing. Cellular service providers may use cell coverage equations from generally accepted signal path loss equations or generate their own proprietary formulae. In either case, once selected, the equations must be calibrated to accurately model a specific cell site. Typical calibrations include calculation of values for geographical environment parameters to account for factors such as, the morphology (e.g. urban, suburban and rural), height differences between the transmitter and remote receiver, and the density and height of terrain features between the two.
As described, the effective planning of cellular networks necessitates the use of suitable models for predicting coverage and interference. Numerous models have been developed and described in the literature. See, for example, IEEE Vehicular Technology Society Committee on Radio Propagation: “Special Issue on Mobile Radio Propagation”, IEEE Transactions on Vehicular Technology , vol. VT-37, no. 1, February 1988, pp.3-72. These models are typically semi-deterministically or empirically based and therefore must be calibrated for specific environments (i.e. a model calibrated for urban Tokyo is likely to be different from that of rural Texas). The calibration process involves modifying the model parameters to accurately approximate relevant measurement data. Typically the propagation models include parameters that account for the geographical environment, e.g. whether the environment is urban or rural, the ground height relative to the transmitter and the terrain between the transmitter and receiver. This environmental information can be obtained from a Geographical Information System (GIS) and should be included in the analysis.
Cellular service providers may use propagation measurement data to calibrate these signal path loss equations. Propagation measurement data is obtained through actual field measurements taken at various locations throughout the cell. Precise measurement locations may be determined using a Global Positioning System (GPS). Typically, a large number of field measurements may be required to accurately calibrate a modeling equation. Once the raw data is collected, it is converted to the appropriate format and used to individualize the cell site to its location.
The calibration process uses the field data collected to define parameters, variable coefficients and constants of equations used to model cell coverage. The calibration is a laborious manual, procedure requiring the significant time and effort of someone skilled in the art.
Automated calibration processes may use basic linear regression techniques on each of the model parameters. See, for example, Bernardin P., et. al.: ‘Cell Radius Inaccuracy: A New Measure Of Coverage Reliability’, IEEE Trans. Veh. Techn ., vol. 47, no. 4, November 1998, pp.1215-1226. However these techniques exhibit two significant problems.
A first problem is caused by variability in the measurement data that can bias the calibration process to produce a model with results falling outside of the set of physically realizable solutions, i.e., a model that effectively defies the laws of physics. For example, the signal attenuation in a cellular environment can be attributed to signal dispersion and sometimes to losses due to signal diffraction and reflection. Accordingly, the minimum loss (in the far field) is equivalent to that associated with signal dispersion, which is defined as the free space loss. Since the free space loss represents a lower bound that cannot be explicitly included in a basic linear regression process, sometimes models that do not make physical sense are generated.
A second problem results from a fundamental assumption of linear regression that the model parameters are uncorrelated, and can therefore be solved independently. That is, each parameter should be independent of variations in the other parameters. However in practice the propagation models used for cellular environments contain parameters that are correlated, for example the diffraction loss is generally correlated with the effective height of the receiver. Accordingly, linear regression can only be used reliably for model calibration when there is a low correlation between the model parameters.
Because of the shortfalls with the existing calibration processes, cellular propagation models are commonly calibrated manually. This technique includes the “artful weaking” of parameter values in repeated attempts to conform the model to the actual field measurements. As expected, interative manual calibration is difficult, time consuming and error prone. In addition, the process may produce hidden anomalies such as singularities in the solution set that might go unnoticed during a manual calibration process but which might produce erroneous predictions when the model is implemented.
Accordingly, a need exists for an automatic calibration device and method of calibrating a radio frequency coverage model to reflect environmental factors and accurately reflect field test data. A need further exists for a method of calibrating a cellular system model that accommodates correlated parameter variables. A further need exists for a cellular model that avoids erroneous solutions attributable to perceived or actual local minimum in favor of global minimum.
SUMMARY OF THE INVENTION
In view of the above, a need exists for an automated equation calibration system and method that provides solutions consistent with physically realizable solutions sets defined by accepted laws and principles of radio transmission theory and other laws of physics, and accommodates correlated variables. A further need exists for a calibration model that includes additional system characteristics to minimize or avoid any manual determination of the calibrated equations.
These and other objects, features and technical advantages are achieved by a system and method that represents measurement and associated data in a matrix form. An automated method is used to calibrate the equations and then evaluate and accept or reject the calibrated equations. The calibrated equations are adjusted if necessary. The user can review the decision to accept the calibrated equation or may adjust the measurement data used in the calibration of the modeling equation. The final calibrated equations are then stored for later use. Models may include the storage of measurement and related information associated within a single row of a matrix. The user may delete specific measurements and associated data from consideration, select or generate specific modeling equations, review calibrated equations or judge criteria, adjust differences between successive calibration equations. A second order gradient search may be designated as the default calibration scheme with the use of a pseudo-exhaustive search for a secondary calibration scheme.
The foregoing has outlined rather broadly the features and technical advantages of the present invention in order that the detailed description of the invention that follows may be better understood. Additional features and advantages of the invention will be described hereinafter which form the subject of the claims of the invention. It should be appreciated by those skilled in the art that the conception and specific embodiment disclosed may be readily utilized as a basis for modifying or designing other structures for carrying out the same purposes of the present invention. It should also be realized by those skilled in the art that such equivalent constructions do not depart from the spirit and scope of the invention as set forth in the appended claims.
BRIEF DESCRIPTION OF THE DRAWING
For a more complete understanding of the present invention, and the advantages thereof, reference is now made to the following descriptions taken in conjunction with the accompanying drawings.
FIG. 1 is a logic flow diagram providing an overview of the measurement data collection and radio propagation model calibration processes.
FIG. 2 is a logic flow diagram for implementing a radio propagation model calibration system according to the invention.
FIG. 3 is a block diagram of the system used for the data collection process in STEP 100 of FIG. 1 . It illustrates the antenna gains, cable losses and transmit power information required for STEP 120 in FIG. 1 .
FIG. 4 is a block diagram of the Modified Newton Second Order Gradient Method to be used for the radio propagation model calibration procedure illustrated in FIG. 2, when the optimization model has a convex (or approximately convex) feasible set and objective function.
FIG. 5 is an illustration of convex and non-convex feasible sets for a constrained optimization model.
FIG. 6 is an illustration of a convex objective function.
FIG. 7 is a block diagram of the pseudo-exhaustive search optimization method to be used by the radio propagation model calibration procedure illustrated in FIG. 2, when the optimization model does not have a convex (or approximately convex) feasible set and objective function.
FIG. 8 is an illustration of typical antenna gain information provided in manufacturers' specifications.
FIG. 9 is a block diagram of a method to approximate the three dimensional antenna gain using two dimensional horizontal and vertical gain information.
FIG. 10 is a bock diagram illustrating a method for calculating the clutter categories of the radio propagation model.
FIG. 11 is a block diagram which shows the processes for the data collection Steps described in FIG. 1 .
DETAILED DESCRIPTION
A model and calibration software according to the invention may be implemented using commercially available development tools, such as Visual C++. The resultant calibration procedures are capable of calibrating cellular propagation models with constrained and correlated model parameters.
For all model calibration techniques an objective function must be defined and represent the objective of the calibration process. In addition it is necessary to define parameter constraints (i.e. the maximum allowable range for each model parameter). The most suitable calibration process depends on the characteristics of the model. If the optimization process is based on minimizing the mean square error between the model predictions and measurement data (which is normally the case when calibrating radio propagation models), it is shown in R. L. Rardin, “ Optimization in operations research ”, Prentice Hall, 1998, that the calibration model has a convex objective function, which is illustrated in FIG. 5 and implies when a local minima is identified, it is also a global minimum. FIG. 5 provides an illustration of convex and non-convex feasible sets for a constrained optimization model. The Diagram in the upper left portion of the figure demonstrates a convex feasible set, which implies that any solution within the feasible set can be reached from any other solution in the feasible set. The diagram in the lower right of the figure demonstrates a non-convex feasible set, which implies that there is no guarantee of being able to move freely between all solutions within the feasible set. A three-dimentional representation of a convex objective function is presented in FIG. 6 .
In addition, if linear (which is typically the case), the model constraints have a convex feasible set, where the feasible set represents the range over which compliance with the model constraints is achieved. Convex and non-convex feasible sets are illustrated in FIG. 4, where it is demonstrated that for convex conditions, the feasible global minimum can be reached from anywhere within the feasible set. Consequently, the calibration process for outdoor propagation models can often be treated as convex and, therefore, a gradient optimization method will provide an optimal solution.
FIG. 1 depicts an overview of the measurement data collection and radio propagation model calibration processes. Referring to FIG. 1, drive-test information is collected at step 100 using appropriate drive-test equipment such as the Comarco Wireless Technologies baseLINE drive test data collection system. The drive-test equipment automatically collects carrier wave measurements from either an existing cell site or from a dedicated test transmitter. A software interface may be used with other drive test tools and formats, such as wireless measurement systems available from Grayson Wireless and the RSAT-2000 system available from LCC International, Inc. When an existing cell site is used for the propagation measurements, a transceiver in the cell site is programmed to transmit a carrier wave at a frequency that does not experience or minimizes co-channel or adjacent channel interference.
At step 102 , the software processes the measurement data into a suitable format for a modeling/GIS (geographical information system) tool, such as MapInfo™, or PlaNET™. Typically the data will be processed into a matrix format consisting of the coordinates of the measurement location and the received signal power at that location. The reformatted data is then processed at step 104 to extract and provide necessary geographical information at each measurement data point, (i.e. clutter classifications, terrain heights and diffraction losses).
Relevant site information is loaded from a text file at step 106 including the antenna height(s), type(s) and orientation, and the cable losses and transmission powers. This information is used to calculate the separation distance, effective height and orientation of the measurement receiver relative to the site and indicate the type of antenna used by the site, which is loaded in Step 108 , and the cable losses and transmission power.
Text files of cell site antenna characteristics including antenna gain in both the horizontal and vertical planes are provided at step 108 . The measured data is then normalized at step 120 to compensate for the antenna gains and the cable losses and transmission powers. Step 122 further refines the data by including previously processed drive-test data for similar measurement environments.
Default model parameters are provided at step 124 , including, for example, the nominal, minimum and maximum parameter values. This data is used at step 126 to process the normalized field strength data and provide a calibrated model. The computed parameters form the calibrated model are stored at step 128 .
The software described herein can be applied to any calibration model for which there is relevant environmental and measurement information. Accordingly, it can be applied to other optimization problems such as for the calibration of in-building cellular path-loss models and other radiation systems in which measured field strength values are used to optimize and calibrate a model.
A significant number of empirical radio frequency path-loss models have been developed in the literature. In general these models account for the distance dependency of the path-loss and other parameters which account for diffraction losses, the relative heights of the transmitting and receiving antennas and the environmental clutter characteristics. For example, the path-loss estimates in the PlaNet™ network planning tool characterize the loss, {tilde over (L)}(dB), by,
{tilde over ( L )}( dB )= K 1 +K 2 log 10 ( d )+ K 3 log 10 ( h eff )+ K 4 Diff+K 5 log 10 ( d ) log 10 ( h eff )+ K 6 log 10 ( h meff )+ K clut , Equation (1)
where the variables are defined in Table 1.
TABLE 1
Model parameter descriptions for Equation (1).
Variable
Description
K 1
Represents a fixed loss associated with the propagation
environment. Commonly this is known as the coupling loss.
K 2
Distance dependency factor of the path-loss, where d is the
path-length
K 3
Effective height factor of the receiving antenna relative to that
of the transmitter, namely h eff .
K 4
Accounts for the diffraction loss, Diff
K 5
Accounts for the inter-relationship between d and h eff on the
path loss.
K 6
Effective height of the mobile factor, h meff
K clut
Represents the environmental clutter factor. This information
can be obtained from geographical data.
The path-loss model given in Equation (1) is used to illustrate the calibration procedure described herein. This procedure utilizes an optimization process which minimizes the mean square error between the measured and predicted path-loss. Since each measurement has values for d, h eff , Diff, h meff , the objective function of the optimization process, f( K ), is given by, f ( K _ ) = min { 1 m ∑ i = 1 m ( P L i - K _ · P _ i ) 2 , Equation ( 2 )
where PL i is the ith path-loss measurement K=[K 1 ,K 2 ,K 3 ,K 4 ,K 5 ,K 6 ,1], m is the number of measurement samples and, P i is given by, P i _ = [ 1 log 10 ( d i ) log 10 ( h eff i ) Diff log 10 ( d i ) · log 10 ( h eff i ) log 10 ( h meff i ) K Chrt i ] . Equation ( 3 )
Generally, the characteristics of the radio path-loss model selected determines the “optimal” calibration process. The radio propagation model calibration software provides several different methods of calibration. In particular, when a convex objective function is coupled with a convex feasible set, this ensures that a local minimum is also the global minimum within the feasible set. In this case the modified Newton Second Order gradient optimization method, which is depicted in FIG. 4, will provide an optimal solution. However, when the software encounters optimization models that do not have a convex (or approximately convex) feasible set and objective function, a pseudo-exhaustive search procedure is adopted for the calibration process.
The objective function expressed in Equation (2) is based on the minimum mean square error between the measurement data and the model predictions, and is therefore convex. Suitable constraints for the objective function in Equation (2) might be, (K 2 +K 5 min(P 3,i ))>20, 0≦K 4 ≦1 and K 1 ,K 3 ,K 6 >0, which are linear and therefore ensure that the feasible set is convex. Consequently, the modified Newton second order gradient method can be used to calibrate the model.
FIG. 4 is a block diagram of the Modified Newton Second Order Gradient Method to be used by the radio propagation model calibration procedure illustrated in FIG. 2, when the optimization model has a convex (or approximately convex) feasible set and objective function
Referring to FIG. 4, at Step 402 , the initial model parameters, K (0) and the model constraints, K min and K max , are loaded. In addition, the stopping tolerance, ε>0, which indicates the required accuracy of the calibration process, is loaded and the solution index is reset, t←0.
The gradient of the objective function indicates its rate of convergence at a particular solution point and therefore provides important information for the calibration process. Accordingly, at Step 404 the objective function gradient, □f( K (t) ), which is the vector of the first order partial derivatives of the objective function, and the Hessian matrix, H( K (t) ), which is the matrix of the second order partial derivatives of the objective function, are calculated at the current point, K (t) . The gradient and Hessian matrix of the objective function expressed in Equation (2) are given by, ∇ f ( K _ ( t ) ) = [ - 2 m ∑ i = 1 m ( L i - K _ · P _ i ) - 2 m ∑ i = 1 m ( L i - K _ · P _ i ) · P 1 , i - 2 m ∑ i = 1 m ( L i - K _ · P _ i ) · P 2 , i - 2 m ∑ i = 1 m ( L i - K _ · P _ i ) · P 3 , i - 2 m ∑ i = 1 m ( L i - K _ · P _ i ) · P 4 , i - 2 m ∑ i = 1 m ( L i - K _ · P _ i ) · P 5 , i ] and Equation ( 4 ) H ( K _ ( t ) ) = [ 2 m , 2 m ∑ i = 1 m P 1 , i , 2 m ∑ i = 1 m P 2 , i , 2 m ∑ i = 1 m P 3 , i , 2 m ∑ i = 1 m P 1 , i P 2 , i , 2 m ∑ i = 1 m P 4 , i 2 m ∑ i = 1 m P 1 , i , 2 m ∑ i = 1 m P 1 , i 2 , 2 m ∑ i = 1 m P 1 , i P 2 , i , 2 m ∑ i = 1 m P 1 , i P 3 , i , 2 m ∑ i = 1 m P 1 , i 2 P 2 , i , 2 m ∑ i = 1 m P 1 , i P 4 , i 2 m ∑ i = 1 m P 2 , i , 2 m ∑ i = 1 m P 1 , i P 2 , i , 2 m ∑ i = 1 m P 2 , i 2 , 2 m ∑ i = 1 m P 2 , i P 3 , i , 2 m ∑ i = 1 m P 1 , i P 2 , i 2 , 2 m ∑ i = 1 m P 2 , i P 4 , i 2 m ∑ i = 1 m P 3 , i , 2 m ∑ i = 1 m P 1 , i P 3 , i , 2 m ∑ i = 1 m P 2 , i P 3 , i , 2 m ∑ i = 1 m P 3 , i 2 , 2 m ∑ i = 1 m P 1 , i P 2 , i P 3 , i , 2 m ∑ i = 1 m P 3 , i P 4 , i 2 m ∑ i = 1 m P 1 , i P 2 , i , 2 m ∑ i = 1 m P 1 , i 2 P 2 , i , 2 m ∑ i = 1 m P 1 , i P 2 , i 2 , 2 m ∑ i = 1 m P 1 , i P 2 , i P 3 , i , 2 m ∑ i = 1 m P 1 , i 2 P 2 , i 2 , 2 m ∑ i = 1 m P 1 , i P 2 , i P 4 , i 2 m ∑ i = 1 m P 4 , i , 2 m ∑ i = 1 m P 1 , i P 4 , i , 2 m ∑ i = 1 m P 1 , i P 4 , i , 2 m ∑ i = 1 m P 2 , i P 4 , i , 2 m ∑ i = 1 m P 1 , i P 2 , i P 4 , i , 2 m ∑ i = 1 m P 4 , i 2 ] Equation ( 5 )
Before commencing with the calibration process it is necessary to determine whether the current point, K (t) is sufficiently close to being stationary that the calibration process can stop. This is determined at Step 406 by calculating whether, ∥∇f( K (t) )∥≦ε, where, ∥∇f( K (t) )∥, is the gradient norm of the objective function and is given by, ∇ f ( K _ ( t ) ) ≡ ∑ j ( ∂ f ∂ K j ) 2 . Equation ( 6 )
If further calibration is required, the optimization move, Δ K (t+1) is calculated at Step 408 based on the “Newton Step” which is given by
ΔK (t+1) =−∇f ( K (t) )·( H ( K (t) )) −1 . Equation (7)
The expression for Δ K (t+1) is derived from the second order Taylor Series approximation which is given by,
f 2 ( K (t) +Δ K (t+1) )= f ( K (t) )+∇ f ( K (t) )Δ K (t+1) +Δ K (t+1) ·H ( K (t) )·Δ K (t+1) . Equation (8)
To determine the move Δ K (t+1) it is necessary to calculate the local optimum of the second order approximation by differentiating it with respect to the components of Δ K (t+1) to give
∇ f 2 (Δ K (t+1) )=∇ f ( K (t) )+ H ( K (t) )·Δ K (t+1) =0, Equation (9)
which can be expressed in terms of the “Newton Step” that is given in Equation (7).
Steps 420 and 422 involve updating the optimization model to the new value and incrementing the model index, t.
At Step 424 the model parameters, K (t) are reviewed to determine whether any model constraints are violated, or equivalently, whether any K i (t) <K (i)min or K i (t) >K (i)max . If there are any model parameters that have values below or above the model constraints, they are set to the minimum and maximum values, respectively, and then excluded from the gradient and Hessian matrix calculations. This approach can be adopted since the optimization model has a convex feasible set and objective function.
The clutter categories are calculated at Step 426 using the process shown in FIG. 10 . The clutter categories are used to bias the propagation predictions based on the environmental conditions. In particular, for outdoor radio propagation models different environmental clutter losses are used for urban, suburban and rural environments to account for the changes in the typical density of obstacles in the propagation path between the transmitter and receiver. Similar clutter classifications can be used in in-building environments to account for areas with differing densities of obstacles such as furniture and wall partitions.
At Step 428 the process returns to Step 404 to continue the optimization cycle.
When the optimization model does not have the required convex characteristics, the software may adopt a pseudo-exhaustive search algorithm. An implementation of a pseudo-exhaustive search procedure is present in FIG. 7 . The initial step size and initial values for the calibration parameters are loaded at Steps 702 and 704 , respectively and at Step 706 the parameter constraint information is loaded.
An order in which the parameters are to be calibrated is selected at step 708 so that the best results are obtained when the most critical parameters, e.g. those relating to distance, antenna height, etc., are considered before less significant parameters. At Step 722 the objective function value is calculated for the incremented and decremented calibration parameters and a result is selected which provides the best fit, i.e. a solution within an acceptable set is selected at step 724 .
A noise component is added to the initial step size at step 720 and the incremented and decremented parameter values are calculated. This technique of adding a noise component helps avoid convergence on an identification of local minima to the exclusion of global solutions.
At Step 728 , as the parameters are being calibrated, the measurement data for each clutter category is treated separately and K clut for the new model parameter is calculated using the linear regression technique described in FIG. 10 . The bottom of the calculation loop occurs at Step 730 , which requires repetition of Steps 720 - 728 for each calibration parameter. The bottom of another loop is defined at Step 740 wherein the step and noise insertion parameters are reduced and Steps 720 - 728 are repeated. Step 742 requires repetition of a process using a specific starting point until no further improvement within a specified tolerance range are achieved. Thus, Step 742 includes repetition of Steps 720 - 740 , however starting from different starting points to identify a best solution set.
Although the NLP approach produces good results, the calibration process is relatively inefficient. Accordingly, as previously described, the software maybe enhanced for reasonably convex objective functions to initially ignore the constraints and determine whether the solution falls within the feasible region. If so then the solution is retained, otherwise the technique described above is used to find a feasible solution (using the unconstrained solution as a starting point). The unconstrained non-linear model can usually be solved using the conventional gradient method, also described previously.
FIG. 2 depicts a logical flow for implementing a radio propagation model calibration system according to the invention including a procedure which permits a standardized approach to model calibration regardless of the radio propagation path loss model selected. Load Data step 202 enables the user to input the processed radio propagation data collected in a form which can be used by the Radio Propagation Model Calibration Software. The user selects the type of propagation model desired for use at Step 204 or, alternatively, defines additional or alternative models, not currently available in the database. At Steps 206 , 208 220 and 222 the software determines whether a modified Newton second order or pseudo-exhaustive search algorithm is to be recommended for the calibration process. The software indicates to the user the recommended calibration method and provides an option for choosing the desired algorithm in Step 228 .
Step 240 optimizes the coefficients within the selected propagation model through the use of the nominated search algorithm. Once the software has calibrated the parameters, the results are displayed at Step 242 , including the calibrated model parameters and the objective function value. If the user is not satisfied with the result, a data filter at step 246 may be used to eliminate any questionable portions of the radio propagation data used in the optimization. Once the questionable portions of the propagation data are eliminated, the user may re-select and re-run the optimization process to produce more accurate parameters. Finally, the calculated parameter results are stored at Step 248 .
FIG. 3 shows an example of a configuration used for measuring actual propagation readings within the coverage area of the measurement site including a block diagram of the system used for the data collection process which is described in STEP 100 of FIG. 1 and illustrating the antenna gains, cable losses and transmit power information required for STEP 120 in FIG. 1 . Either a test transmitter or an existing cell site generates an radio signal in the appropriate frequency range (e.g., 800-900 MHz for cellular systems) that can be received by the tuned radio receiver's antenna and fed to the tuned radio receiver. If an existing cell site is used, the cell site's transceiver is programmed to transmit a carrier wave at the specified frequency so as to avoid co-channel or adjacent channel interference to the maximum extent possible. This may be done by taking the co-channel or adjacent channel devices out of service. A GPS receiver is co-located with the measurement receiver to provide accurate position data of the specific monitor point location within the radio propagation coverage area. Data collected from various points are aggregated to mitigate variability attributable to multi-path fading, and then stored in a text file with the associated GPS coordinates. These results are stored in the data capture, aggregation and storage device. One technique for mitigating multipath fading described in, Lee W. C. Y., “ Mobile Radio Systems ”, McGraw Hill, New York 1985, recommends the measurement data is averaged over distances of approximately 40 wave-lengths (i.e. between approximately 600 and 1450 centimeters for cellular radio operating frequencies). Data is continually captured, aggregated and stored as the radio receiver is moved through the radio coverage area of the measurement transmitter (or cell site). FIG. 11 shows additional detail pertaining to the accumulation of additional data for the radio propagation model calibration in accordance with FIG. 1 .
FIG. 3 illustrates how the cable losses, antenna gains, transmit power and path loss affect the measured signal at the mobile receiver, P r , which can be expressed as,
P r =P t −L t +G t −L r +G r −PL, Equation (10)
where P t and represent the transmitted power, PL represents the radio propagation loss (path-loss) between the transmitter and receiver, and L and G refer to the cable losses and antenna gains, respectively. The intention of the calibration process is to tune a propagation model to characterize the path-loss, PL. Consequently, the power normalization process (STEP 120 in FIG. 1) requires that the cable losses and antenna gains are calculated for each measurement data point. The cable losses are generally static and can be easily measured. However the antenna gains depend on the three dimensional radiation patterns and orientations of the transmitting and receiving antennas and therefore need to be calculated at each measurement location.
FIG. 8 depicts the antenna gain information typically provided in manufacturers' specifications. Since this information is expressed in terms of the two dimensional gain in the horizontal and vertical planes, a simple linear interpolation technique based on the vertical and horizontal antenna patterns can be used to approximate the three dimensional antenna gain. This calculation is well known to those skilled in the art.
A technique for approximating the three dimensional antenna gain at any arbitrary angle is outlined in FIG. 9 and is similar that used in advanced cellular modeling tools. At Step 902 , the antenna gain in the horizontal direction H a is determined for the angle of the measurement data relative to the antenna location, θ. The intermediate angular field data may be obtained by interpolation of actual data.
As part of the antenna gain calculation it is necessary to calculate the difference between the actual antenna gain in the horizontal direction at angle, θ, and the linear approximated gain in the same location. In Step 904 the antenna gains in the bore-sight and back-lobe (180 degrees relative to the bore-sight) are calculated as, H b and H 180 , respectively, and the horizontal linear approximated gain is calculated as, H t = H b - H 180 * θ π ,
in Step 906 . The horizontal differential gain, which is the difference between the actual and linear approximated gains at angle θ, is calculated in Step 908 .
The vertical angle the measurement location makes with the antenna bore-sight, φ, is calculated in Step 920 . This angle is calculated on the basis of the relative heights and separation distances between the radio transmitting and receiving antennas. The vertical angle, φ, is used in Step 922 to calculate the vertical gains in the front and rear lobes, namely V f(φ) and V r(φ) , respectively, and the difference between these gains.
In Step 924 , the approximate three dimensional antenna gain is calculated as, G ( θ , φ ) = V f ( φ ) - ( V b ( φ ) * θ π ) + H Δ Equation ( 11 )
Referring to FIG. 11, a suitable site is chosen at Step 1102 to have radio propagation characteristics that require modeling. Since only a small number of propagation models are typically used when modeling an entire network, it is important to ensure that the measurement sites are chosen carefully. In addition, to avoid measurement errors, it is important to use radio channel that does not experience non-negligible co-channel and adjacent channel interference. Configuration of the equipment is performed at Step 1104 (this configuration is depicted in FIG. 3 ). At Step 1108 , the drive test route is specified and data is collected and aggregated. Finally, the data is saved at Step 1120 (including the field measurement data and the associated GPS coordinates) for later processing and evaluation.
Another aspect of the invention can be used to calibrate RF models for use indoors. When calibrating typical in-building propagation models the processed information required at each data point differs from that required in outdoor systems as follows:
The number and types of walls and floors in the propagation path are taken into consideration. This information is derived from digitized floor plans and the associated loss is calculated based on the angle of the wall or floor relative to that of the assumed propagation path. Depending on the required accuracy, it may be necessary to account for the effect of windows and doorways.
An estimate of the losses attributable to each type of wall and floor is made. These losses may be measured or derived from published results (depending on the required accuracy).
When measuring the in-building path-loss, the method described above can be adopted, however rather than using a GPS system (which cannot be used reliably indoors) it is usual to scan a floor plan into a computer with a touch sensitive screen. As measurement data is collected, the operator uses the touch sensitive screen to indicate the location of the data on the floor plan. As part of the post processing, this information is converted into the effective propagation path-length and is used to determine the location of obstacles, such as walls and floors, in the radio propagation path between the transmitter and receiver.
In an in-building environment the approximate path-loss can be expressed as,
{tilde over ( L )}( dB )= K 1 +K 2 log 10 ( d )+ Q ( WAF )+ P ( FAF ) Equation (12)
where Q(WAF) and P(FAF) account for the signal attenuation attributable to the building walls and floors, respectively.
The objective function for the optimization process, f(L i , {tilde over (L)} i ), can be expressed as, f ( L i , L ~ i ) = min [ 1 m ∑ i = 1 m ( L i ( dB ) - L i ( dB ) ) 2 ] , Equation ( 13 )
where m is the number of data measurements, and L i (dB) and {tilde over (L)} i (dB) represent the measured and predicted path-loss, respectively, at the ith data point.
Although the present invention and its advantages have been described in detail, it should be understood that various changes, substitutions and alterations can be made herein without departing from the spirit and scope of the invention as defined by the appended claims. Moreover, the scope of the present application is not intended to be limited to the particular embodiments of the process, machine, manufacture, composition of matter, means, methods and steps described in the specification. As one of ordinary skill in the art will readily appreciate from the disclosure of the present invention, processes, machines, manufacture, compositions of matter, means, methods, or steps, presently existing or later to be developed that perform substantially the same function or achieve substantially the same result as the corresponding embodiments described herein may be utilized according to the present invention. Accordingly, the appended claims are intended to include within their scope such processes, machines, manufacture, compositions of matter, means, methods, or steps.
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A system and method that provides radio field strength modeling useful for determining cellular telephone site coverage. The system and method automate sampling procedures, collecting data at various monitoring points within a radio propagation coverage area. The collected data is then interpolated and spurious samples are eliminated. The resultant radio field strength data and respective location data is then analyzed using either a modified Newton second order gradient or a pseudo-exhaustive search method to modeling the field strength for convex and non-convex models, respectively. An iterative approach is used to facilitate the use of model constraints and to mitigate calibration errors attributable to highly correlated variables. For pseudo-exhaustive searches, noise is introduced into the data analysis routines to avoid convergence on local minimum which would otherwise inhibit convergence towards global solutions.
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FIELD OF THE INVENTION
[0001] The present invention is applicable in general to all-terrain boards arranged to be ridden by a rider standing on a board member such as skate boards, mountain boards, grass boards and similar devices which may have two, three or four wheels.
[0002] Braking systems for all-terrain boards have been described previously such as in International Patent Application No. PCT/AU98/01007.
[0003] However, there is a need for a braking system for all-terrain boards which enables braking to be effected in a way which is safe, convenient, effective, reliable and predictable.
[0004] The present invention provides an all-terrain board having a braking system which, at least in part, provides safe, convenient, effective, reliable and predictable braking under a range of conditions.
SUMMARY OF THE INVENTION
[0005] In accordance with one aspect of the present invention there is provided an all-terrain board arranged to be ridden by a rider standing on a board member, which comprises a wheel means and a brake means having a braking member arranged to be engaged by a leg of a rider so as to apply braking force to the wheel means of the board.
[0006] In one embodiment of the present invention, the braking member may be arranged to act directly on a wheel of the board. In particular, the braking member may be arranged to act on a tyre of the wheel to impart braking force to the wheel.
[0007] In another embodiment of the present invention the braking member may act indirectly on a wheel of the board. In particular, the braking member may be arranged to cause a braking device to act on a rim of the wheel to impart braking force to the wheel
BRIEF DESCRIPTION OF THE DRAWINGS
[0008] The present invention will now be described, by way of example, with reference to the accompanying drawings, in which:
[0009] [0009]FIG. 1 is a side elevation of an all-terrain board in accordance with a first embodiment of the present invention;
[0010] [0010]FIG. 2 is a view similar to FIG. 1 showing a brake means being applied by a rider;
[0011] [0011]FIG. 3 is a view of a rear portion of the all-terrain board of FIG. 1 to an enlarged scale;
[0012] [0012]FIG. 4 is a view similar to FIG. 3 showing a brake means being applied;
[0013] [0013]FIG. 5 is a side elevation of part of a rear portion of an all-terrain vehicle according to a second embodiment of the present invention showing a brake means;
[0014] [0014]FIG. 6 is a side elevation similar to FIG. 5 showing the brake means being applied to a wheel rim;
[0015] [0015]FIG. 7 is a plan view of the second embodiment of FIG. 5; and
[0016] [0016]FIG. 8 is a plan view similar to FIG. 7 showing the brake means being applied to a wheel rim.
DESCRIPTION OF THE INVENTION
[0017] In FIGS. 1 to 4 of the accompanying drawings, there is shown an all-terrain board 10 including a leading wheel 12 , a rear wheel 14 and a frame 16 interconnecting the wheels 12 and 14 . Each wheel 12 and 14 is provided with a tyre 15 . Further, a board member 17 is mounted on the frame 16 between the wheels 12 and 14 . The board 10 is provided with a brake means 19 .
[0018] As shown in FIGS. 1 and 2 the all-terrain vehicle 10 is arranged to be ridden by a rider 18 standing on the board member 17 .
[0019] As can best be seen in FIGS. 3 and 4 an upright braking member 20 of the brake means 19 extends upwardly from the frame 16 . The braking member 20 is connected to the frame 16 of the board 10 about a transverse pivotal mounting 22 (see FIGS. 3 and 4). Further, the braking member 20 has a concave shape facing the tyre 15 of the rear wheel 14 . Preferably, internally of the concave shape the brake member 20 is provided with a brake contact surface 24 which is formed of material having suitable wear and friction properties to withstand the pressure and temperature of braking against the tyre. Preferably, spring means (not shown) is provided to return the braking member 20 to the non-engaged position shown in FIG. 3 when no force is applied to the braking member 20 .
[0020] In use, the rider 18 rides the all-terrain board 10 in the manner shown in FIG. 1. However, if the rider 18 decides to reduce the speed of the all-terrain board 10 when in motion he simply has to lean backward as shown in FIG. 2. This prevents a rider 18 from being thrown forward when braking and is a natural, safe stance for a rider to maintain when an all-terrain board is slowing down. However, as can be seen in FIG. 2, the arrangement of the present invention enables the rider 18 to apply pressure to the braking member 20 by means of the calf of his rearwardly disposed leg. This causes the braking member 20 to contact the tyre 15 of the rear wheel 14 by means of the brake contact surface 24 . As a result a braking force is applied to the rear wheel 14 and the all-terrain board 10 is caused to slow down. The braking member 20 may be made of steel, aluminium, plastics material or composite material whilst the braking contact surface 24 may be formed of rubber, metal, composite material or suitable plastics material able to withstand the heat, pressure and friction created by braking against the tyre 15 . In this regard, relatively low coefficient of friction plastic materials have been found to offer suitable performance for low cost.
[0021] In FIGS. 5 to 8 there is shown a portion of a rear part of an all-terrain vehicle 50 which is similar to that shown in FIGS. 1 to 4 .
[0022] The vehicle 50 has a rear wheel 52 mounted on a frame 54 . The wheel 52 has a rim 56 having a tyre 58 extending thereabout. The vehicle 50 is provided with a brake means 59 .
[0023] A braking member 60 of the brake means 59 is mounted to the frame 54 by means of a transverse pivotal mounting 62 . Further, as can best be seen in FIGS. 5 and 6, an upright plate member 64 is fixedly mounted to the frame 54 just in front of the mounting 62 of the braking member 60 .
[0024] The plate member 64 has an aperture (not shown) therein through which projects a flexible cable 66 . The cable 66 has a nipple 68 mounted at outer end thereof adjacent to the plate member 64 . The nipple 68 is larger than the aperture in the plate member 64 so that the outer end of the cable 66 cannot pass through the aperture.
[0025] The cable 66 then passes through a conduit 70 which may include a length adjustment means 72 .
[0026] As can be seen in FIGS. 7 and 8, the cable 66 is connected to a bicycle type V-brake 74 . The V-brake 74 has a pair of arms 76 pivotally mounted on pivot points 78 and extending forwardly thereof. The conduit 70 is connected to a leading end of a first arm 76 via a swivel cage 82 pivoting off a leading end of one arm 76 . The cable 66 exits the conduit 70 at one end of the cage 82 and extends across to a cable clamping screw 84 at a leading end of the other arm 76 . Further, forwardly of but adjacent to the pivot points 78 each arm 76 is provided with a brake pad 80 .
[0027] As can be seen in the drawings, in operation, a rider as shown in FIG. 2, applies pressure to the braking member 60 by means of the calf of a rearwardly disposed leg and pivots the braking member 60 about the pivot 62 so as to move the braking member 60 away from the nipple 68 and therefore shorten the effective length of the cable 66 between the leading ends of the arms 76 . This causes these leading ends to be drawn towards each other about the pivot points 78 and therefore causes the brake pads 80 to engage with the rim 56 . This action applies braking force to the wheel 52 and therefore slows down the all-terrain vehicle 50 when it is in motion.
[0028] Each pair of brake arms 76 incorporates internal spring means for returning the arms 76 to the position shown in FIG. 7 when braking is no longer required and pressure ceases to be applied to the braking member 60 .
[0029] V Brakes have been used as the example to describe the braking means. However, it is important to note that the principle of a rider leaning against a calf operated lever to activate a cable or hydraulic operated brake also applies to other types of braking mechanisms such as disk brakes and hub brakes.
[0030] Modifications and variations such as would be apparent to a skilled addressee are deemed within the scope of the present invention.
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An all-terrain board ( 10, 50 ) ridden by a rider ( 18 ) standing on the board ( 10, 50 ) is provided with a braking member which can be engaged by a leg of the rider ( 18 ) and moved into braking engagement with a wheel ( 14, 52 ). The braking engagement may be directly onto a tyre ( 15 ) of the wheel ( 14 ). Alternatively, the braking engagement may be indirectly onto a wheel ( 52 ) through a linkage connecting the brake ( 60 ) to a brake mechanism ( 74 ) acting on a rim ( 56 ) of the wheel ( 52 ).
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This application is a continuation of application Ser. No. 10/463,873, filed Jun. 18, 2003, which claims the benefit of Provisional Application No. 60/398,824, filed Jul. 29, 2002, the entire contents of which are hereby incorporated by reference in this application.
BACKGROUND OF THE INVENTION
The present invention relates to an implantable constriction device for constricting the urethra, urine bladder, anus, colon or rectum of an incontinent patient.
This kind of constriction device, in the form of a banding device in which a band encircles and adjustably constricts a portion of a patient's urethra, urine bladder, anus, colon or rectum, has been used in surgery for treating anal and urinary incontinence. In practice, the band is made of silicone, which is a material approved and widely used for implantation. Moreover, the silicone band has an acceptable tensile strength and is fairly resistant to aggressive body fluids. Where the band is hydraulically adjusted, the hydraulic fluid used typically is an isotonic salt solution mixed with other conventional materials.
A problem with traditional silicone bands, however, is that the silicone material gives the band certain inadequate properties, such as poor fatigue resistance and poor endurance of static bending forces, which over time might result in breakage of the band. Furthermore, silicone is a material that is semi-permeable by liquid, which is a drawback to hydraulic silicone bands, because hydraulic fluid can escape by diffusing through the silicone material. As a result, accurate adjustments of a hydraulic band are difficult to perform because of the loss of hydraulic fluid and the need for the patient to regularly visit a doctor to add hydraulic fluid to and calibrate the constriction device. These inadequate properties are serious, considering that the band is implanted for the rest of the patient's life. Another problem is that the band somewhat restrains the dynamic movements of adjacent organs necessary for the transportation of urine or fecal matter. As a consequence, the band might erode, and over time injure the urethra, urine bladder, anus, colon or rectum.
SUMMARY OF THE INVENTION
The object of the present invention is to provide a new implantable constriction device for treating urinary and anal incontinence having improved properties as compared to traditional constriction devices.
Accordingly, the present invention provides an implantable constriction device for treating an incontinent patient, the device comprising an elongate composite structure adapted to constrict the urethra, urine bladder, anus, colon or rectum of the patient, wherein the elongate composite structure is composed of a base material making the composite structure self-supporting and property improving means for improving at least one physical property of the composite structure other than self-supporting properties.
In accordance with a first embodiment of the invention, the property improving means comprises a coating on the base material at least along a side of the elongate composite structure that is intended to contact the urethra, urine bladder, anus, colon or rectum, wherein the coating has better aggressive body fluid resistance than the base material. Such a coating may comprise a Teflon™, i.e., PTFE or poly-tetra-flouro-ethylene, or Parylene™, i.e., poly-paraxylylene polymer, coating, or a biocompatible metal coating, such as gold, silver or titanium. As a result, the constriction device can be protected from damaging influences of aggressive body fluids, possibly for the rest of the patient's life.
Where traditional silicone material constitutes the base material, a Teflon™, i.e., PTFE or poly-tetra-flouro-ethylene, or Parylene™, i.e., poly-paraxylylene polymer, coating also provides the composite structure with better anti-friction properties than the base material. Good anti-friction properties of the composite structure reduce the risk of the elongate composite structure eroding the urethra, urine bladder, anus, colon or rectum. This is proven by tests, in which the surface of traditional silicone bands has been polished before use. Accordingly, the test results indicate significant improvements in avoiding erosion of the urethra, urine bladder, anus, colon or rectum.
Furthermore, the Teflon™, i.e., PTFE or poly-tetra-flouro-ethylene, Parylene™, i.e. poly-paraxylylene polymer, or metal coating also makes the composite structure, in which the base material is made of silicone, stronger than the traditional silicone band. A stronger band reduces the risk of fracture.
In one alternative to the first embodiment, the elongate composite structure is designed for mechanical adjustment, such as the mechanical solutions disclosed in International Application No. WO 01/45486. In this alternative, the property improving means comprises a core of a soft viscoelastic material, such as silicone gel, typically having a hardness less than 20 Shure, cellulose gel or collagen gel. Where silicone gel is chosen, it may be “Med 3-6300” manufactured by Nusil. Hard silicone constitutes the base material, typically having a hardness of at least 60 Shure, and covers the soft core of viscoelastic material. The soft core makes the implanted elongate composite structure less injurious to the urethra, urine bladder, anus, colon or rectum, and reduces the injury of such organs. Furthermore, the soft core of viscoelastic material may be formed to enclose and protect mechanical adjustment components and other components of the composite structure, whereby fibrosis is prevented from growing into such components.
In another alternative to the first embodiment, the elongate composite structure is designed for hydraulic adjustment, such as the hydraulic solutions disclosed in International Application No. WO 01/50833. In this alternative, the base material forms a closed tubing, which can be inflated by adding hydraulic fluid to the interior of the tubing and deflated by withdrawing hydraulic fluid from the interior of the tubing. The coating of Teflon™, Parylene™ or metal may cover the inner surface of the tubing. The base material may form two coaxial tubular layers of hard silicon, and the property improving means may comprise a tubular intermediate layer of a soft viscoelastic material located between the coaxial tubular layers. Alternatively, the base material may form an outer tubular layer and an inner arcuate layer attached to the outer tubular layer, the outer and inner layers defining a curved space extending longitudinally along the tubing. The property improving means may comprise a viscoelastic material filling the space. The tubing is applied around the urethra, urine bladder, anus, colon or rectum so that the space with viscoelastic material is located closest to the urethra, urine bladder, anus, colon or rectum. The viscoelastic material gives the advantages that erosion of the urethra, urine bladder, anus, colon or rectum is reduced and the risk of hydraulic fluid leaking from the tubing is decreased.
In accordance with a second embodiment of the invention, the base material forms a first layer and the property improving means comprises a second layer applied on the first layer, wherein the second layer is more fatigue resistant than the first layer. The first layer preferably is comprised of hard silicone, whereas the second layer preferably is comprised of a polyurethane layer. In a traditional silicone band, especially the tubular type, that is formed in a loop to constrict the urethra, urine bladder, anus, colon or rectum, the inner surface of the band loop that contacts the urethra, urine bladder, anus, colon or rectum forms bulges and creases that repeatedly change as the band is subjected to dynamic movements from the urethra, urine bladder, anus, colon or rectum and when the size of the band is adjusted. As a consequence, the implanted traditional silicone band has the drawback that it may crack after some time due to fatigue of the silicone material. With the elongate composite structure of the invention, in which hard silicone may constitute the base material and a fatigue resistant polyurethane layer covers the silicone material on the side of the elongate composite structure that contacts the urethra, urine bladder, anus, colon or rectum, this drawback is eliminated.
The property improving means suitably comprises a coating that may be coated on the layer of hard silicone and/or the layer of polyurethane, wherein the coating has better aggressive body fluid resistance properties and/or better anti-friction properties-.than hard silicone. As described above in connection with the first embodiment, the coating may comprise a Teflon™ or Parylene™ coating, or a biocompatible metal coating.
The layer of hard silicone may form an inflatable tubing and the layer of polyurethane may cover the hard silicone layer within the tubing.
In accordance with a third embodiment of the invention, the base material forms an inflatable tubing and the property improving means comprises a liquid impermeable coating coated on the base material. The coating may be coated on the external and/or internal surface of the tubing. Preferably, the liquid impermeable coating comprises a Parylene™, i.e., poly-paraxylylene polymer, coating, or a biocompatible metal coating. Where hard silicone, which is a liquid semi-permeable material, constitutes the base material, the coating of Parylene™, i.e., poly-paraxylylene polymer, or metal gives the advantage that the tubing may be inflated by hydraulic fluid under pressure without risking fluid diffusing through the silicone wall of the tubing.
Also, in the third embodiment, the base material may form two coaxial tubular layers of hard silicon, and the property improving means may comprise a tubular intermediate layer of a soft viscoelastic material located between the coaxial tubular layers. Alternatively, the base material may form an outer tubular layer of hard silicone and an inner arcuate layer of silicone attached to the outer tubular layer. The outer and inner layers define a curved space extending longitudinally along the tubing and filled with the viscoelastic material. The tubing is intended to be applied around the urethra, urine bladder, anus, colon or rectum so that the space with viscoelastic material is located closest to the urethra, urine bladder, anus, colon or rectum.
In accordance with a fourth embodiment of the invention, the property improving means comprises gas, such as air, contained in a multiplicity of cavities formed in the base material to improve the flexibility of the composite structure. In this case, Teflon™, i.e., PTFE or poly-tetra-flouro-ethylene, advantageously constitutes the base material. The cavities may be defined by net structures of the Teflon™, i.e., PTFE or poly-tetra-flouro-ethylene, material. Thus, the resulting composite structure of Teflon™, i.e., PTFE or poly-tetra-flouro-ethylene, and cavities filled with gas is strong, flexible and aggressive body fluid resistant, and has good tensile strength and good anti-friction properties. Also, in the fourth embodiment, the elongate composite structure may comprise an inflatable tubing.
The present invention also provides an implantable constriction device for treating an incontinent patient, comprising an elongate composite structure adapted to constrict the urethra, urine bladder, anus, colon or rectum of the patient, wherein the composite structure includes an elongate biocompatible self-supporting base material having surfaces exposed to aggressive body cells, when the constriction device is implanted in the patient, and a cell barrier coating on the surfaces to prevent body cells from breaking down the base material, which is typically silicone. If the base material were broken down by such body cells, typically macrophages or killer cells, histological particles would be spread in the human body.
The barrier coating may comprise a Parylene™ , i.e., poly-paraxylylene polymer, coating or a biocompatible metal coating.
Alternatively, the barrier coating may comprise a composite of different materials to achieve the cell-barrier protection as described above. There are several examples of such composite materials on the market, for example a composite of polyurethane and silicone called Elaston™.
BRIEF DESCRIPTION OF THE DRAWINGS:
FIG. 1 is a front view of a mechanical constriction device according to the present invention.
FIG. 2 is an enlarged cross-section along the line II-II in FIG. 1 .
FIGS. 3 and 4 are modifications of the embodiment shown in FIG. 2 .
FIG. 5 is a front view of a hydraulic constriction device of the invention.
FIG. 6 is an enlarged cross-section along the line VI-VI in FIG. 5 .
FIGS. 7-10 are modifications of the embodiment shown in FIG. 6 .
FIG. 11 is a modification of the embodiment shown in FIG. 2 .
Referring to the drawing figures, like reference numerals designate identical or corresponding elements throughout the several figures.
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 illustrates a mechanical constriction device 2 according to the invention comprising an elongate composite structure 4 adapted to extend around and constrict the urethra, urine bladder, anus, colon or rectum of a patient. Referring to FIG. 2 , the elongate composite structure 4 comprises a strong band 6 of nylon or the like, a tubular layer 8 of hard silicone, in which the band 6 slides, a soft layer 10 of a viscoelastic material, here a silicone gel having a hardness not more than 20 Shure, encircling the hard silicone layer 8 , and a tubular layer 12 of a self-supporting base material of hard silicone having a hardness of at least 60 Shure, surrounding the soft silicon layer 10 . A coating 14 of Teflon™, i.e. PTFE or poly-tetra-flouro-ethylene, Parylene™, i.e., poly-paraxylylene polymer, or a biocompatible metal, such as gold, silver or titanium, is coated on the outer hard silicone layer 12 to make the composite structure resistant to aggressive body fluids and to give the composite structure good anti-friction properties. A coating of Teflon™, i.e., PTFE or poly-tetra-flouro-ethylene, ParyleneTM, i.e., poly-paraxylylene polymer., or metal may also be coated on the internal surface of the inner tubular hard silicone layer 8 to reduce the friction between the nylon band 6 and the layer 8 . The constriction device 2 has an adjustment means 16 that can displace the end portions of the nylon band 6 relative to each other to either increase or decrease the constriction of the urethra, urine bladder, anus, colon or rectum.
FIG. 3 shows an elongate composite structure 18 similar to that of FIG. 2 , except that a layer 20 of a fatigue resistant material, here polyurethane, is applied on the hard silicone layer 12 along the inner side of the structure 18 that is intended to contact the urethra, urine bladder, anus, colon or rectum. Alternatively, the layer 20 may be tubular and surround the layer 12 .
FIG. 4 shows a cross-section of an elongate composite structure 22 of an embodiment of the invention, in which Teflon™, i.e.. PTFE or poly-tetra-flouro-ethylene, constitutes the self-supporting base material, which is formed with a longitudinal cavity in which a strong nylon band 24 slides. Property improving means in the form of a gas, here air, contained in a multiplicity of cavities 26 are formed in the base material to improve the flexibility thereof.
FIGS. 5 and 6 show a hydraulic constriction device 28 according to the invention comprising an elongate composite structure in the form of an inflatable tubing 30 , in which the base material of hard silicone forms an outer tubular layer 32 and an inner coaxial layer 34 . A viscoelastic material, here soft silicone gel, forms an intermediate layer 36 located between the tubular layers 32 and 34 . Four longitudinal partition walls 38 between the tubular layers 32 and 34 divide the intermediate layer 36 into four sections to prevent the silicone gel from displacing in the circumferential direction of the tubing 30 . (Also, the embodiments according to FIGS. 2 and 3 may be provided with such longitudinal partition walls.) The outer layer 32 is coated with a coating 40 of Teflon™, i.e., PTFE or poly-tetra-flouro-ethylene, Parylene™, i.e., poly-paraxylylene polymer., or metal. Also, the inner layer 34 may be coated with a coating of Teflon™, i.e., PTFE or poly-tetra-flouro-ethylene, Parylene™, i.e., poly-paraxylylene polymer, or metal. If a Parylene™, i.e., poly-paraxylylene polymer, or metal coating is chosen the composite structure will be completely liquid impermeable.
FIG. 7 shows a tubing 42 similar to that of FIG. 6 , except that an inner arcuate layer 44 is substituted for the inner tubular layer 34 . The arcuate layer 44 is attached to the outer tubular layer 32 , so that the outer tubular layer 32 and the arcuate layer 44 define a curved space extending longitudinally along the tubing 42 . A viscoelastic material, here silicone gel 46 , fills the space. In this embodiment there is no need for partition walls of the kind shown in the embodiment shown in FIG. 6 . The tubing 42 is intended to be applied around the urethra, urine bladder, anus, colon or rectum so that the space with the protecting soft silicone gel 46 is located close to the urethra, urine bladder, anus, colon or rectum.
As taught by the embodiment of FIG. 7 , in the composite structures shown in FIGS. 2 and 3 , the soft silicone gel may alternatively be applied in a longitudinal space close to the inner side of the elongate composite structure 4 and 18 , respectively, that is intended to contact the urethra, urine bladder, anus, colon or rectum.
In the same manner as described above in connection with the embodiment of FIG. 3 , a layer of a fatigue resistant material, here polyurethane, may be applied on the outer tubular layer 32 of hard silicone of the tubing 30 and 42 , respectively, along the side of the tubing 30 and 42 , respectively, that is intended to contact the urethra, urine bladder, anus, colon or rectum, when the tubing 30 and 42 , respectively, encircles the urethra, urine bladder, anus, colon or rectum.
FIG. 8 shows a cross-section of an elongate composite structure 48 of an embodiment of the invention, in which Teflon™, i.e., PTFE or poly-tetra-flouro-ethylene, constitutes the self-supporting base material, which is formed to an inflatable tubing 50 . Property improving means in the form of gas contained in a multiplicity of cavities 26 are formed in the base material to improve the flexibility of the tubing 50 .
FIG. 9 shows a cross-section of a tubular composite structure of an embodiment of the invention, in which the self-supporting base material 52 is made of a polymer material suited for implantation, for example silicone or polyurethane. A property improving coating 54 , for example made of Parylene™, i.e., poly-paraxylylene polymer, Teflon™, i.e., PTFE or poly-tetra-flouro-ethylene, or metal, is applied on the external surface or on both the external and internal surfaces of the tubular structure.
FIG. 10 shows the same embodiment as FIG. 9 , except that the base material comprises a layer 56 of polyurethane surrounded by a layer 58 of silicone.
FIG. 11 shows a cross-section of a mechanical constriction device of another embodiment of the invention, comprising a double walled tubing 60 , an external wall 62 and an internal wall 64 spaced from the external wall 62 , of a self-supporting base material of hard silicone. The tubing 60 has partition walls 66 dividing the space between the external and internal walls 62 and 64 , respectively, of the tubing 60 into longitudinal cells 68 , which are filled with a soft viscoelastic material, for example silicone gel. The internal wall 64 is coated with a friction reducing coating 70 , for example made of Teflon™ or the like. A strong band 72 of nylon or the like slides in the tubing 60 on the friction reducing coating 70 to enable adjustment of the constriction device in the same manner as described above in connection with the embodiment according to FIGS. 1 and 2 .
Although the present invention has been described in terms of particular embodiments, it is not intended that the invention be limited to those embodiments. Modifications of the embodiments within the spirit of the invention will be apparent to those skilled in the art. The scope of the invention is defined by the claims that follow.
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An implantable constriction device for treating an incontinent patient comprises an elongate composite structure adapted to constrict the urethra, urine bladder, anus, colon or rectum of the patient. The elongate composite structure is composed of a base material, such as hard silicone, making the composite structure self-supporting. Property improving material is provided for improving at least one physical property of the composite structure other than self-supporting properties, such as fatigue resistance, liquid impermeability, aggressive body cells resistance, anti-friction properties and lifetime.
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BACKGROUND
1. Technical Field
The present invention relates generally to managing access to a computer system, and in particular, to a computer implemented method for securely managing password access to a computer system.
2. Description of Related Art
Passwords are an intrinsic part of functioning within a computerized society. Computer systems often require that a user is authenticated or verified before the user is granted initial or continuing access. Often this authentication or verification is accomplished by requiring the user to enter a password, sometimes with a username, that are known to both the computer system and the user.
Computer systems requiring authentication or verification may be computer devices and/or computer software applications. A computer device requiring a password may be a server, desktop computer, laptop, mobile phone, smart phone, or other type of stationary, portable or mobile device. A computer software application requiring a password for access may be an operating system, browser, website, software program, or other type of software such as a smart phone application.
SUMMARY
The illustrative embodiments provide a method, system, and computer usable program product for providing initial access to the computer system in response to a user providing a first password, and upon detecting a condition meeting a predetermined criteria, providing subsequent access to the computer system in response to the user providing a second password wherein the first password has stronger security than the second password.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS
The novel features believed characteristic of the invention are set forth in the appended claims. The invention itself, further objectives and advantages thereof, as well as a preferred mode of use, will best be understood by reference to the following detailed description of illustrative embodiments when read in conjunction with the accompanying drawings, wherein:
FIG. 1 depicts a block diagram of a network of data processing systems in which various embodiments may be implemented;
FIG. 2 depicts a block diagram of a data processing system in which various embodiments may be implemented;
FIG. 3 depicts a block diagram of a software space for a data processing system in which various embodiments may be implemented;
FIG. 4 depicts a flowchart of the operation of a security manager in which the various embodiments may be implemented;
FIG. 5 depicts a flowchart of the operation of a policy engine in which a first embodiment may be implemented;
FIG. 6 depicts a graphical user interface for setting forth conditions of the policy engine in accordance with the first embodiment; and
FIG. 7 further depicts a flowchart of the operation of a policy engine in which a second embodiment may be implemented.
DETAILED DESCRIPTION
FIG. 1 depicts pictorial representation of a network of data processing systems in which various embodiments may be implemented. Data processing environment 100 is a network of data processing systems also known as computers or computer devices in which the embodiments may be implemented. Software applications may execute on any computer or other type of data processing system in data processing environment 100 . Data processing environment 100 includes network 110 . Network 110 is the medium used to provide communications links between various devices and computers connected together within data processing environment 100 . Network 110 may include connections such as wire, wireless communication links, or fiber optic cables.
Servers 120 and 122 and clients 140 and 142 are coupled to network 110 along with storage unit 130 . In addition, laptops 150 and 152 are coupled to network 110 including wirelessly through s network router 154 . A mobile phone 160 is also coupled to network 110 through a mobile phone tower 162 . Data processing systems, such as server 120 and 122 , client 140 and 142 , laptops 150 and 152 , and mobile phone 160 , may contain data and may have software applications including software tools executing thereon. Other types of data processing systems such as personal digital assistants (PDAs), smart phones, tablets and netbooks may be coupled to network 110 .
Storage 130 may include security manager 136 for managing access to the various computer devices or software applications in accordance with embodiments described herein. Client 140 may include software application 144 and security manager 146 . Laptop 150 and mobile phone 160 may also include software applications 154 and 164 and security managers 156 and 166 . Other types of data processing systems coupled to network 110 may also include software applications and security managers. Software applications could include a web browser, email, or other software application that can process a web page, email, or other type of information to be processed.
Servers 120 and 122 , storage unit 130 , clients 140 and 142 , laptops 150 and 152 , and mobile phone 160 and other data processing devices may couple to network 102 using wired connections, wireless communication protocols, or other suitable data connectivity. Clients 140 and 142 may be, for example, personal computers or network computers.
In the depicted example, server 120 may provide data, such as boot files, operating system images, and applications to clients 140 and 142 and laptop 150 . Clients 140 and 142 and laptop 150 may be clients to server 120 in this example. Clients 140 and 142 , laptops 150 and 152 , mobile phone 160 , or some combination thereof, may include their own data, boot flies, operating system images, and applications. Data processing environment 100 may include additional servers, clients, and other devices that are not shown. For example, other mobile devices may also be connected, to network 102 including smart phones, tablets, personal digital assistants (PDAs), etc.
In the depicted example, data processing environment 100 may be the Internet. Network 110 may represent a collection of networks and gateways that use the Transmission Control Protocol/Internet Protocol (TCP/IP) and other protocols to communicate with one another. At the heart of the Internet is a backbone of data communication links between major nodes or host computers, including thousands of commercial, governmental, educational, and other computer systems that route data and messages. Of course, data processing environment 100 also may be implemented as a number of different types of networks, such as for example, an intranet, a local area network (LAN), or a wide area network (WAN). FIG. 1 is intended as an example, and not as an architectural limitation for the different illustrative embodiments.
Among other uses, data processing environment 100 may be used for implementing a client server environment in which the embodiments may be implemented. A client server environment enables software applications and data to be distributed across a network such that an application functions by using the interactivity between a client data processing system and a server data processing system. Data processing environment 100 may also employ a service oriented architecture where interoperable software components distributed across a network may be packaged together as coherent business applications.
FIG. 2 depicts a block diagram of a data processing system in which various embodiments may be implemented. Data processing system 200 is an example of a computer device, such as server 120 , client 140 , laptop 150 or mobile phone 160 in FIG. 1 , in which computer usable program code or instructions implementing the processes may be located for the illustrative embodiments.
In the depicted example, data processing system 200 includes a CPU or central processing unit 210 which may contain one or more processors and may be implemented using one or more heterogeneous processor systems including a graphics processor. The depicted example also includes a memory 220 which may be used tor storing instructions and data to be processed by CPU 210 . Memory 220 may include a main memory composed of random access memory (RAM), read only memory (ROM), or other types of storage devices. Memory 210 could also include secondary storage devices such as a hard disk drive, DVD drive or other devices which may be internal or external to data processing system 200 . An input output device (I/O) 230 is also shown in the depicted example for managing communications with various input devices and output devices. However, other examples could use the CPU to communicate directly with various input or output devices or use separate input and output controllers.
In the depicted example, a display 240 is shown for the data processing system to communicate with a user or another data processing system. Other types of output devices may be used such as an audio device. An input device 250 is also shown which may be a keyboard, mouse, a touch sensitive display, or other types of input devices.
Data processing system 200 is shown with an internal section 205 and an external section 206 . Often input and output devices may be physically separate from but connected to the CPU and memory. However, that is often not the case such as in mobile phones.
An operating system may run on processor 210 . The operating system coordinates and provides control of various components within data processing system 200 in FIG. 2 . The operating system may be a commercially available operating system. An object oriented programming system may run in conjunction with the operating system and provides calls to the operating system from programs or applications executing on data processing system 200 . Instructions for the operating system, the object-oriented programming system, and applications or programs may be located on secondary storage devices such a hard drive, and may be loaded into RAM for execution by processing unit 210 .
The hardware in FIGS. 1-2 may vary depending on the implementation. Other internal hardware or peripheral devices, such as flash memory, equivalent non-volatile memory, or optical disk drives and the like, may be used, in addition to or in place of the hardware depicted in FIGS. 1 and 2 . In addition, the processes of the embodiments may be applied to a multiprocessor date processing system.
The depicted examples in FIGS. 1-2 and above-described examples are not meant to imply architectural limitations. For example, data processing system 200 may also be a mobile phone 160 , tablet computer, laptop computer, or telephone device.
FIG. 3 depicts a block, diagram of software environment for a data processing system in which the preferred embodiment may be implemented. In a software environment 300 , various software applications may be used by the data processing system for initializing (booting) and running the data processing system. These software programs may be located in the local memory of the data processing system or in the memory of other connected data processing systems such as memory storage of a server.
A BIOS 310 may be used for initializing the data processing system and for various base functions. BIOS (basic input/output system) is typically stored in a local non-volatile memory such as ROM or flash memory on a data processing system motherboard. An operating system (O/S) 320 is used for managing the various computer hardware resources and provides common services for efficient execution of application software. Software applications 330 may be used to perform singular or multiple related specific tasks or functions. An example of a software application would be an internet browser, spreadsheet program, email application, video game, or other function.
Security manager 340 may be used to manage password protection for the data processing system in accordance with the various embodiments described below. Security manager may be called or invoked by each of the types of software shown herein. That is, BIOS 310 may invoke security manager 340 during system initialization. In the preferred embodiment, O/S 320 may invoke security manager 340 upon certain conditions such as when the system is turned on (after BIOS has initialized the system) or when the user attempts to start any application. Any application 330 may also invoke the security manager such as when the application is first started by the user.
Policy engine 350 may be invoked by the security manager. Policy engine may contain the conditions and criteria for determining whether a user may be granted access to a computer system (hardware or software), whether a password may be required, which password may be required for granting access, or whether the user may be denied access. Policy engine 350 may be a separate software entity from security manager 340 or both may be implemented as a single combined entity.
Security manager 340 and/or policy engine 350 may also be incorporated in any of the software used by the data processing system. For example, security manager could be included as part of BIOS 310 , O/S 320 , or any application 330 .
Security manager 340 may be on a particular device such as a mobile phone, PDA, laptop, desktop or other device. Policy engine 350 may be implemented on the same device or on a separate device. For example, security manager could be implemented on a mobile phone while the policy engine may be implemented in a server. In such a case, the security manager may be invoked by the user's actions on a device and then the security manager invokes the policy engine to notify the security manager which action to take (e.g. allow access, require a password or deny access). This and other approaches would allow a central administrator to manage a single policy engine for a multitude of devices.
Another embodiment could use a policy engine on the user device with a centralized set of conditions and criteria stored on a server. The policy engine may then periodically query the conditions and criteria on the server (such as through a localized proxy server) to obtain the latest version of those conditions and criteria and then store those locally for implementation. There are additional alternative approaches where the centralized conditions and criteria may be pushed by the server to user devices with security managers and policy engines. If the policy engine for a user device cannot access the centralized conditions and criteria stored on a server or if no update has been received for a period of time, then a stricter default set of conditions and criteria may be automatically adopted to implement a higher level of security.
Operation of the security manager and policy engine may be session based such as where a given application or website may have certain security requirements. In such a case, the application or website may contain the policy engine and rely on the user device security manager to enforce that security. For example, an application or website may require a very secure password for initial access and then require a second shorter password periodically to allow the user to continue access. In this example, the policy manager may be located on the website server or in the application programming. In an alternative embodiment, the website or application may provide the conditions and criteria for enforcement by the user device security manager and policy engine. In such a case, the conditions and criteria may be downloaded to the user device policy engine, such as with a cookie, when the website or application is initially contacted by the user device. As a result, the user device security manager and policy engine may be used in helping manage such session based security for websites, applications or other types of resources. In these cases, the security manager may be invoked by the website or application for enforcing certain conditions and criteria.
FIG. 4 depicts a flowchart of the operation of a security manager in which the various embodiments may be implemented. This process describes the use of a first password and a second password where the first password has stronger security than the second password. However, a second password would typically be easier for a user to type or otherwise enter and would often be preferred by the user in most cases as a result. Alternative security manager embodiments could also be implemented by one of ordinary skill in the art.
In step 410 , the security manager may be invoked by BIOS, an operating system, an application, or other software program in response to an action by the user or in response to certain conditions be met by the invoking software program. For example, if the user attempts to open a new application on a smart phone, the smart phone operating system may invoke the security manager. Certain information may be passed to the security manager including the location of a computer device, the type of action which caused the security manager to be invoked, or other information useful by the security manager.
In step 420 , various conditions may be applied by a policy engine based on the information passed to the security manager and any other information known by the security manager such as the last time it was invoked. These conditions and their criteria are described in greater detail below with reference to FIG. 5 .
In step 430 , it is determined whether the conditions were not met so that the user or invoking software fails. If so, then access is denied in step 435 to the user or invoking software. In step 440 , if conditions are met such that no password is needed, then access is granted to the user or invoking program in step 450 .
In step 460 , if certain conditions are met from the policy engine conditions in step 420 , then a second password may be acceptable. The second password is typically a shorter and easier to type or enter than a first password. If a second password is acceptable, then in step 465 the user is queried for the second password. Once received, the second password is checked in step 485 against the second password previously stored in the data processing system (or elsewhere accessible by the data processing system). If correct, then the second user or invoking software in allowed access. In the preferred embodiment, the first password may also be acceptable in lieu of the second password. If the second (or first) password was not correct, the processing returns to step 420 .
In step 480 , if a second password would not acceptable according to the policy engine conditions in step 420 , then the user is queried for the first password. If, in step 435 , the first password provided is correct, then the user is allowed access, otherwise processing returns to step 430 .
FIG. 5 depicts a flowchart of the operation of a policy engine in which a first embodiment may be implemented. In this first embodiment, FIG. 5 provides an example of the conditions applied in step 420 of FIG. 4 , although alternative examples and embodiments could easily be implemented such as in FIG. 7 below.
In this first embodiment, the variable P may indicate what password the user must provide. If P is equal to 0, then no password is required. If P is equal to 1, then the second password is acceptable. If P is equal to 2, then the first password is required. If P is equal to 3, then access is denied.
In a first step 500 , it may be determined whether an invalid password was previously provided. If not, then processing continues to step 510 . If yes, then in step 502 it may be determined whether the number on invalid password attempts is greater than the number of acceptable tries. If no in step 502 , then processing returns in step 550 to allow the user to attempt the password again. If yes in step 502 , then P is increased by one and processing returns in step 550 . As a result, if P was previously equal to 1 allowing a second password, then the user must now provide the first password. If P was previously equal to 2 allowing only a first password, then the user may be denied access.
In step 510 , P is set to 0. In step 520 , it may be determined whether the time since the first password was previously entered is less than a minimum. If yes, then processing continues to step 530 . If not, then in step 522 it may be determined whether the time since the first password was entered is greater than a maximum. If yes, the P is set equal to 2 and processing returns in step 550 . If not, then P is set equal to 1 and processing continues to step 530 .
In step 520 , it may be determined whether the time since the first password was previously entered is less than a minimum. If yes, then processing continues to step 530 . If not, then in step 522 it may be determined whether the time since the first password was entered is greater than a maximum. If yes, the P is set equal to 2 and processing returns in step 550 . If not, then P is set equal to 1 and processing continues top step 530 .
In step 530 , it may be determined whether the location of the user is within a minimum distance from a desired location or locations (such as within a few feet of the user's work location). If yes, then processing continues to step 540 . If not, then in step 532 it may be determined whether the user is outside a maximum distance from a desired location(s). If yes, the P is set equal to 2 and processing returns in step 550 . If not, then P is set equal to 1 and processing continues top step 540 .
In step 540 , it may be determined whether the action taken by the user or the type of device being used by the user is a low level threat (such as opening a browser on a desktop computer). If yes, then processing returns in step 550 . If net, then in step 542 it may be determined whether the action taken by the user or the type, of device being used by the user is a high level threat (such as opening a high security database on a mobile phone). If yes, then P is set equal to 2 and processing returns in step 550 . If not, then P is set equal to 1 and processing returns in step 550 .
FIG. 6 depicts a graphical user interface for setting forth conditions and criteria of the policy engine in accordance with the first embodiment. This graphical user interface (GUI) may be used by a user of the data processing system such as a mobile phone or it may be used by an administrator of a network of data processing systems. The administrator may lock this GUI so that no user may adjust its settings. Alternative embodiments may use a different GUI or may require independent programming or other approaches to implement the policy engine.
A graphical user interface window 600 is shown with a variety of boxes to be checked and blanks to be filled in. The conditions and criteria set forth below or in alternative embodiments may be implemented for a single application or all applications for a given user device or all devices on a network.
In column 610 a user or administrator may select which conditions to apply. In this embodiment, if a box is not checked, then the condition to the right of the box is not implemented. Column 620 provides the type of condition that could be applied. Although several conditions are shown in FIG. 6 , different and additional conditions may be used. Column 630 provides the specific criteria or limits for the selected conditions as described below.
Row 640 depicts a time condition and criteria that has been selected in this case as indicated with the checked box in column 610 . The time criteria may be the time since the user entered a valid password, although alternative embodiments may use alternative time measures. The user may provide a minimum time and a maximum time in this case. The time entered could be in seconds, minutes or alternative measure of time. Referring back to FIG. 5 , if the actual time since the last valid password entry is less than the minimum, then no password is needed. If the time is greater than the minimum but less than the maximum, then the user may need to enter a second password. If the time is greater than the maximum, then the user may need to enter a first password which is typically longer and stronger than the second password.
Row 550 depicts a location condition that has been selected in this case as indicated with the checked box in column 610 . The user or administrator may provide latitude and longitude criteria as well as a minimum and maximum distance range criteria. For example, if a data processing device such as a laptop or smartphone is within a minimum distance from a user's workplace (or alternatively a home), then no password is needed. If the data processing device is at a greater distance than a minimum but less than a maximum, then a second password may be needed. If the data processing system is outside a maximum distance then a first password may be needed.
Row 660 depicts a device type condition and criteria. Each type of device may be identified as a low or high risk device in this example. Typically the more mobile a device, the higher the risk. While multiple devices are depicted such as may selected by an administrator, a single data processing apparatus may be depicted when being updated by a user.
Row 670 depicts an action type condition and criteria. Several types of actions are depicted in this example including opening an application such as a spreadsheet application, entering data to an application such as a browser, or even closing an application such as a database application. An action may be any type of action initiated by a user, the user device, of software. An action typically causes the software on the user device to resound in some manner. Many alternative types of actions may be used in alternative embodiment. If may be up to the user, administrator or even software application developer to determine which actions types may initiate invoking the security manager.
Row 680 depicts a maximum number of consecutive invalid passwords attempts allowed by the policy engine. For example, if n is set equal to 2, then after the third invalid attempt of a second password, the user must then provide the first password instead.
FIG. 7 further depicts a flowchart of the operation of a policy engine in which a second embodiment may be implemented. This example utilizes the same conditions and criteria as the first embodiment, yet implements those conditions and criteria differently. Alternative embodiments may use other conditions or use alternative implementations.
In this second embodiment, as in the first embodiment, the variable P indicates what password the user must provide. If P is equal to 0, then no password is required. If P is equal to 1, then the second password is acceptable. If P is equal to 2, then the first password is required. If P is equal to 3, then access is denied. Alternative embodiments may use other methods for indicating which passwords may be acceptable in those embodiments.
In a first step 700 , it may be determined whether an invalid password was previously provided. If not, then processing continues to step 710 . If yes, then in step 702 it may be determined whether the number of invalid password attempts is greater than the number of acceptable tries. If no in step 702 , then processing returns in step 702 to allow the user to attempt the password again. It yes in step 702 , then P is increased by one and processing returns in step 770 . As a result, if P was previously equal to 1 allowing a second password, then the user must now provide the first password. If P was previously equal to 2 allowing only a first password, then the user is denied access.
In step 710 , P is set to 0. In step 720 , it may be determined whether the type of threat is high, such as if the device is a mobile device. If no, the processing continues to step 722 , otherwise processing continues to step 730 . In step 722 , if time since the last valid password is not greater than a maximum, then processing returns to the security manager in step 770 . If time since the last valid password is greater than a maximum, then processing continues to step 724 . In step 724 , P is set equal to 1 and processing returns to the security manager in step 770 .
In step 730 , it may be determined whether time since the last valid password is less than a minimum. If yes, then processing continues to step 724 described above, otherwise processing continues to step 740 .
In step 740 , it may be determined whether the time since the last valid password is greater than a maximum. If yes, then in step 744 P is set equal to 2 and processing returns to the security manager through step 770 . If time since the last valid password is not greater than a maximum, then processing continues to step 750 .
In step 750 , it may be determined whether the location of the data processing device is within a minimum distance of a desired location. If yes, then P is set equal to 1 in step 754 and processing returns to the security manager through step 710 . If no, then processing continues to step 760 . In step 760 , if the location of the data processing device is within a maximum distance from a desired location, the processing continues to step 754 as described above. Otherwise, in step 764 P is set equal to 2 and processing returns to the security manager through step 770 .
Although the first and second embodiments described above refer to a first and second password, alternative embodiments could utilize three or more passwords. In addition, these passwords could be fully independent or subsets of each other. For example, the second password could be a character string and the first password could be the same character string concatenated with a second character string such as a number generated by an encryption key generator.
Various types of conditions and criteria may be developed other than those described herein. For example, the security manager could be invoked when any application is initiated on a user device such as a mobile phone. For the first application or for any highly secure application, the first password may be required before access to that application is allowed. For applications with less security concerns, a second password or possibly no password may be required before access is provided. However, other conditions may apply as well. For example, even if an application has less security concerns, if a sufficient time has passed, a first password may be required anyway.
The invention can take the form of an entirely software embodiment, or an embodiment containing both hardware and software elements. In a preferred embodiment, the invention is implemented in software or program code, which includes but is not limited to firmware, resident software, and microcode.
As will be appreciated by one skilled in the art, aspects of the present invention may be embodied as a system, method or computer program product. Accordingly, aspects of the present invention may take the form of an entirely hardware embodiment, an entirely software embodiment (including firmware, resident software, micro-code, etc.) or an embodiment combining software and hardware aspects that may all generally be referred to herein as a “circuit,” “module” or “system.” Furthermore, aspects of the present invention may take the form of a computer program product embodied in one or more computer readable medium(s) having computer readable program code embodied thereon.
Any combination of one or more computer readable medium(s) may be utilized. The computer readable medium may be a computer readable signal medium or a computer readable storage medium. A computer readable storage medium may be, for example, but not limited to, an electronic, magnetic, optical, electromagnetic, infrared, or semiconductor system, apparatus, or device, or any suitable combination of the foregoing. More specific examples (a non-exhaustive list) of the computer readable storage medium would include the following: an electrical connection having one or more wires, a portable computer diskette, a hard disk, a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EEPROM), or Flash memory, an optical fiber, a per cable compact disc read-only memory (CD-ROM), an optical storage device, a magnetic storage device, or any suitable combination of the foregoing. In the context of this document, a computer readable storage medium may be any tangible medium that can contain, or store a program for use by or in connection with an instruction execution system, apparatus, or device.
A computer readable signal medium may include a propagated data signal with computer readable program code embodied therein, for example, in baseband or as part of a carrier wave. Such a propagated signal may take any of a variety of forms, including, but not limited to, electro-magnetic, optical, or any suitable combination thereof. A computer readable signal medium may be any computer readable medium that is not a computer readable storage medium and that can communicate, propagate, or transport a program for use by or in connection with an instruction execution system, apparatus, or device.
Program code embodied on a computer readable medium may be transmitted using any appropriate medium, including but not limited to wireless, wireline, optical fiber cable, RF, etc., or any suitable combination of the foregoing. Further, a computer storage medium may contain or store a computer-readable program code such that when the computer-readable program code is executed on a computer, the execution of this computer-readable program code causes the computer to transmit another computer-readable program code over a communications link. This communications link may use a medium that is, for example without limitation, physical or wireless.
A data processing system suitable for storing and/or executing program code will include at least one processor coupled directly or indirectly to memory elements through a system bus. The memory elements can include local memory employed during actual execution of the program code, bulk storage media, and cache memories, which provide temporary storage of at least some program code in order to reduce the number of times code must be retrieved from bulk storage media during execution.
A data processing system may act as a server data processing system or a client data processing system. Server and client data processing systems may include data storage media that are computer usable, such as being computer readable. A data storage medium associated with a server data processing system may contain computer usable code such as the security manager or policy engine. A client data processing system may download that computer usable code, such as for storing on a data storage medium associated with the client data processing system, or for using in the client data, processing system. The server data processing system may similarly upload computer usable code from the client data processing system such as conditions and criteria for a policy engine. The computer usable code resulting from a computer usable program product embodiment of the illustrative embodiments may be uploaded or downloaded using server and client data processing systems in this manner.
Input/output or I/O devices (including but not limited to keyboards, displays, pointing devices, etc.) can be coupled to the system either directly or through intervening I/O controllers.
Network adapters may also be coupled to the system to enable the data processing system to become coupled to other data processing systems or remote printers or storage devices through intervening private or public networks. Modems, cable modem and Ethernet cards are just a few of the currently available types of network adapters.
The description of the present invention has been presented for purposes of illustration and description, and is not intended to be exhaustive or limited to the invention in the form disclosed. Many modifications and variations will be apparent to those of ordinary skill in the art. The embodiment was chosen and described in order to explain the principles of the invention, the practical application, and to enable others of ordinary skill in the art to understand the invention for various embodiments with various modifications as are suited to the particular use contemplated.
The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. As used herein, the singular forms “a”, “an” and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms “comprises” and/or “comprising,” when used in this specification, specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof.
The corresponding structures, materials, acts, and equivalents of all means or step plus function elements in the claims below are intended to include any structure, material, or act for performing the function in combination with other claimed elements as specifically claimed. The description of the present invention has been presented for purposes of illustration and description, but is not intended to be exhaustive or limited to the invention in the form disclosed. Many modifications and variations will be apparent to those of ordinary skill in the art without departing from the scope and spirit of the invention. The embodiment was chosen and described in order to best explain the principles of the invention and the practical application, and to enable others of ordinary skill in the art to understand the invention for various embodiments with various modifications as are suited to the particular use contemplated.
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A method, system or computer usable program product for providing initial access Lo the computer system in response to a user providing a first password, and upon detecting a condition meeting a predetermined criteria, providing subsequent access to the computer system in response to the user providing a second password wherein the first password has stronger security than the second password.
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BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to a decoding apparatus, a decoding method, and a decoding program for decoding a low-frequency component from a first coded data obtained by coding a low-frequency component in an audio signal, and decoding the high-frequency component of the audio signal from a second coded data that is used to decode a high-frequency component in the audio signal and the low-frequency component.
[0003] 2. Description of the Related Art
[0004] In recent years, in order to code audio or music, High-Efficiency Advanced Audio Coding (HE-AAC) has been used. The HE-AAC format is an audio compression format mainly used in Moving Picture Experts Group phase 2 (MPEG-2), or Moving Picture Experts Group phase 4 (MPEG-4).
[0005] In the HE-AAC, a low-frequency component in a frequency of an audio signal (signal relating to audio, music, etc.) to be coded is coded according to Advanced Audio Coding (AAC), and a high-frequency component in the frequency is coded according to Spectral Band Replication (SBR). In the SBR format, the high-frequency component in the frequency of the audio signal can be coded using smaller number of bits than that used in the other formats by coding only a part that is hard to predict from the low-frequency component in the frequency of the audio signal. Hereinafter, the data coded according to the AAC format is referred to as AAC data, and the data coded according to the SBR format is referred to as SBR data.
[0006] Now, an example of a decoder that decodes data (hereinafter, referred to as HE-AAC data) coded according to the HE-AAC format is described. FIG. 19 is a functional block diagram illustrating a configuration of a known decoder. As illustrated in FIG. 19 , a decoder 10 includes a data separation section 11 , an AAC decoding section 12 , an analysis filter section 13 , a high-frequency generation section 14 , and synthesis filter section 15 .
[0007] The data separation section 11 is a processing section that when HE-AAC data is acquired, separates AAC data and SBR data contained in the acquired HE-AAC data respectively, outputs the ACC data to the AAC decoding section 12 , and outputs the SBR data to the high-frequency generation section 14 .
[0008] The AAC decoding section 12 is a processing section that decodes AAC data and outputs the decoded AAC data as AAC output audio data to the analysis filter section 13 . The analysis filter section 13 is a processing section that calculates a characteristic between time necessary for the low-frequency component in the audio signal and a frequency based on the ACC audio data acquired from the AAC decoding section 12 , and outputs the calculation result to the synthesis filter section 15 and the high-frequency generation section 14 . Hereinafter, the calculation result outputted from the analysis filter section 13 is referred to as low-frequency component data.
[0009] The high-frequency generation section 14 is a processing section that generates a high-frequency component in the audio signal based on the SBR data acquired from the data separation section 11 and the low-frequency component data acquired from the analysis filter section 13 . Further, the high-frequency generation section 14 outputs the data of the generated high-frequency component as high-frequency component data to the synthesis filter section 15 .
[0010] The synthesis filter section 15 is a processing section that synthesizes the low-frequency component data acquired from the analysis filter section 13 with the high-frequency component data acquired from the high-frequency generation section 14 and outputs the synthesized data as HE-AAC output audio data.
[0011] FIG. 20 is a view for outlining a processing performed in the decoder 10 . As illustrated in FIG. 20 , the decoder 10 replicates a part of low-frequency component data, and adjusts an electric power of the replicated data to generate high-frequency component data. Then, the decoder 10 synthesizes the low-frequency component data with the high-frequency component data to generate HE-AAC output audio data. As described above, the HE-AAC data (audio signal, etc.) that is coded according to the HE-AAC format is decoded as the HE-AAC output audio data by the decoder 10 .
[0012] In Japanese Laid-open Patent Publication No. 2005-338637, a technique for improving auditory quality is disclosed. In the technique, a value of a scale factor in an audio signal is adjusted to correct a mismatch between powers of the audio signal before coding and after coding.
[0013] However, the above-described known technique cannot solve a problem that after an audio signal that contains an attack sound (signal that has a sharp amplitude change) is coded, when the coded audio signal is decoded, it is not possible to appropriately decode a high-frequency component in a frequency of the audio signal.
[0014] The problem in the known technique is specifically described. FIGS. 21A and 21B are views for explaining the problem in the known technique. As illustrated in FIGS. 21A and 21B , in a case where an audio signal that contains an attack sound whose amplitude sharply changes in an extremely short duration is coded according to the SBR format, because of characteristics in the SBR format, a time domain where the attack sound is generated can be extremely short (or, a temporal resolution in the SBR format becomes poorer than that in the AAC format) as compared to a time domain divided according to the SBR format. Then, the power in the time domain that contains the attack signal is averaged, and the attack sound is coded in a state the attack sound is temporally extended.
[0015] That is, it is very important problem to be solved to correct the high-frequency component in the coded audio signal and appropriately decode the audio signal even if the high-frequency component in the audio signal containing the attack signal is not appropriately coded according to the HE-AAC format. Especially, it is important to accurately correct the duration of the attack sound contained in the high-frequency components even if a steady component other than the attack sound exists in the low-frequency components that are coded according to the AAC format.
SUMMARY
[0016] According to an aspect of an embodiment, a method for regenerating an audio signal including a low frequency component and a high frequency component by decoding a coded data including a first coded data and a second coded data, the method comprising the steps of: generating the low frequency component; generating the high frequency component; determining whether the low frequency component has transient characteristics or not; generating a low frequency correction component by removing a stationary component when the audio signal has the transient characteristics; generating a corrected high frequency component by correcting the high-frequency component on the basis of the duration of the low frequency correction component when the audio signal has the transient characteristics; and regenerating the audio signal by synthesizing the low frequency component with the corrected high-frequency component.
BRIEF DESCRIPTION OF THE DRAWINGS
[0017] FIGS. 1A to 1C are views for illustrating outlines and features of a decoder according to a first embodiment of the present invention;
[0018] FIG. 2 is a view illustrating a configuration of a decoder according to a first embodiment of the present invention;
[0019] FIG. 3 is a view illustrating low-frequency component data;
[0020] FIG. 4 is a view illustrating a processing performed in a transient characteristic detection section;
[0021] FIG. 5 is a view illustrating a configuration of a high-frequency correction section;
[0022] FIG. 6 is a view illustrating electric powers E 1 and E h on a time-frequency axis;
[0023] FIG. 7 is a view illustrating a method for calculating a correction coefficient;
[0024] FIG. 8 is a flowchart illustrating a processing procedure performed in a decoder according to the first embodiment of the present invention;
[0025] FIG. 9 is a view illustrating a configuration of a decoder according to a second embodiment of the present invention;
[0026] FIG. 10 is a flowchart illustrating a processing procedure performed in a decoder according to the second embodiment of the present invention;
[0027] FIG. 11 is a view illustrating a configuration of a decoder according to a third embodiment of the present invention;
[0028] FIG. 12 is a view illustrating a processing performed in a stationarity removing section according to the third embodiment of the present invention;
[0029] FIG. 13 is a flowchart illustrating a processing procedure performed in a decoder according to the third embodiment of the present invention;
[0030] FIG. 14 is a view illustrating a configuration of a decoder according to a fourth embodiment of the present invention;
[0031] FIG. 15 is a view illustrating a grouping data;
[0032] FIG. 16 is a view illustrating a processing performed in a stationarity removing section according to the fourth embodiment of the present invention;
[0033] FIG. 17 is a flowchart illustrating a processing procedure performed in a decoder according to the fourth embodiment of the present invention;
[0034] FIG. 18 is a flowchart illustrating a hardware configuration of a computer that forms the decoders according to the first to fourth embodiments of the present invention;
[0035] FIG. 19 is a functional block diagram illustrating a configuration of a known decoder;
[0036] FIG. 20 is a view for outlining a processing performed in a decoder; and
[0037] FIGS. 21A and 21B is views for explaining a problem in a known technique.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0038] Preferred embodiments of a decoding apparatus, decoding method, and decoding program according to the present invention will be described in detail with reference to the attached drawings.
First Embodiment
[0039] First, an outline and features of a decoder according to a first embodiment is described. FIGS. 1A to 1 c are views for illustrating outlines and features of the decoder according to the first embodiment of the present invention. The decoder according to the first embodiment decodes coded audio signal using AAC data obtained by coding a low-frequency component in an audio signal according to the AAC format, and SBR data obtained by coding a high-frequency component in the audio signal according to the SBR format (that is, the decoder decodes the coded audio signal using the HE-AAC format).
[0040] Especially, if the audio signal contains an attack sound (in a case where the audio signal has transient characteristics), the decoder according to the first embodiment removes a stationary component contained in the low-frequency component data obtained by decoding the AAC data, corrects a duration of the high-frequency component data (high-frequency component data in the audio signal that is generated using the low-frequency component data and the SBR data) to match with a duration of the low-frequency component data (corrected low-frequency data) from which the stationary component is removed, and synthesizes the corrected high-frequency component data (corrected high-frequency data) with the low-frequency component data to decode the audio signal (see FIGS. 1A to 1C ).
[0041] As described above, the decoder according to the first embodiment removes the stationary component in the low-frequency component data, corrects the high-frequency component data to match with the duration of the low-frequency component data, and synthesizes the corrected high-frequency data with the low-frequency component data to decode the audio signal. Accordingly, if the audio signal that contains the sound source having the strong transient characteristics such as the attack sound is decoded, it can be prevented that the attack sound temporally extends, and deterioration in the sound quality of the audio signal can be prevented.
[0042] Further, the decoder according to the first embodiment removes the stationary component contained in the low-frequency component data, and corrects the high-frequency component data to match with the duration of the low-frequency component data from which the stationary component is removed. Accordingly, the duration of the high-frequency component data can be accurately corrected.
[0043] Now, a configuration of the decoder according to the first embodiment is described. FIG. 2 is a view illustrating a configuration of a decoder 100 according to a first embodiment of the present invention. As illustrated in FIG. 2 , the decoder 100 includes a data separation section 110 , an AAC decoding section 120 , and an SBR decoding section 125 . The SBR decoding section 125 includes an analysis filter section 130 , a high-frequency generation section 140 , a transient characteristic detection section 150 , an LPC analysis section 160 a , an LPC inverse filter section 160 b , a high-frequency correction section 170 , and a synthesis filter section 180 .
[0044] The data separation section 110 is a processing section that, when HE-AAC data (audio signal coded according to the HE-AAC format) is acquired, separates AAC data and SBR data contained in the acquired HE-AAC data respectively, outputs the AAC data to the AAC decoding section 120 , and outputs the SBR data to the high-frequency generation section 140 .
[0045] The AAC decoding section 120 is a processing section that decodes the AAC data acquired from the data separation section 110 , and outputs the decoded AAC data as AAC output audio data to the analysis filter section 130 and the transient characteristic detection section 150 . The AAC output audio data indicates a characteristic of time and an electric power (power) in the low-frequency component in the audio signal.
[0046] The analysis filter section 130 is a processing section that calculates a characteristic of a time period and a frequency for a low-frequency component in the audio signal based on the AAC output audio data acquired from the AAC decoding section 120 , and outputs the calculated result to the LPC analysis section 160 a , the LPC inverse filter section 160 b , and the synthesis filter section 180 . Hereinafter, the calculation result outputted from the analysis filter section 130 is referred to as low-frequency component data. FIG. 3 is a view illustrating the low-frequency component data. In embodiments of the present invention, in order to remove a stationary component in the low-frequency component data, LPC an analysis is performed on each frequency band (32 bands in a case of the HE-AAC) in the low-frequency component data.
[0047] The high-frequency generation section 140 is a processing section that generates a high-frequency component of the audio signal based on SBR data acquired from the data separation section 110 and low-frequency component data acquired from the analysis filter section 130 . The high-frequency generation section 140 outputs the generated data of the high-frequency component (hereinafter, referred to as high-frequency component data) to the high-frequency correction section 170 .
[0048] The transient characteristic detection section 150 is a processing section that acquires AAC output audio data from the AAC decoding section 120 and determines whether an attack sound is contained in the HE-AAC data based on the acquired AAC output audio data (determines whether the HE-AAC data has transient characteristics or not).
[0049] Now, a processing performed in the transient characteristic detection section 150 is specifically described. FIG. 4 is a view illustrating a processing performed in the transient characteristic detection section 150 . The transient characteristic detection section 150 stores a plurality of pieces of AAC output audio data acquired in the past in a storage section (not shown), calculates an average electric power of each piece of AAC output audio data stored in the storage section, and stores the calculation results. Further, the transient characteristic detection section 150 calculates a value by adding a predetermined threshold to the average electric power and a value by subtracting a predetermined threshold from the average electric power, and stores the values.
[0050] When the AAC output audio data is acquired, the transient characteristic detection section 150 compares the electric power of the acquired AAC output audio data, the value obtained by the addition and the value obtained by the subtraction with each other, and determines whether the HE-AAC data has transient characteristics or not. If the electric power of the AAC output audio data is equal to the value obtained by the addition or more and less than the value obtained by the subtraction, the transient characteristic detection section 150 determines that the HE-AAC has transient characteristics. If the electric power of the AAC output audio data is equal to the value obtained by the subtraction or more and less than the value obtained by the addition, the transient characteristic detection section 150 determines that the HE-AAC has steady characteristics (see FIG. 4 ). Then, the transient characteristic detection section 150 outputs the determination result to the high-frequency correction section 170 .
[0051] The LPC analysis section 160 a is a processing section that acquires the low-frequency component data from the analysis filter section 130 , performs an LPC analysis on the acquired low-frequency component data, and calculates an LPC coefficient. If a frequency band of the low-frequency component data is k (see FIG. 3 ), the LPC analysis is performed on X low (0, k), X low (1, k) . . . , X low (N−1,k) to calculate an LPC coefficient α i (k) ( i =1, . . . , p).
[0052] The N denotes the number of time samples of a current frame (low-frequency component data). The p denotes a maximum order of an LPC coefficient. To calculate the LPC coefficient, known methods such as Levinson-Durbin algorithm or a covariance method can be used. In a case where the low-frequency component data is a complex number, the above-described LPC analysis is performed on a real part and an imaginary part of the low-frequency component data respectively.
[0053] The LPC inverse filter section 160 b is a processing section that acquires low-frequency component data from the analysis filter section 130 and generates corrected low-frequency data by removing a stationary component from the low-frequency component data using an LPC coefficient acquired from the LPC analysis section 160 a.
[0054] For example, if a maximum order of an LPC coefficient is 2 (p=2), a real part and an imaginary part in corrected low-frequency data (equations of an inverse filter of the real part and the imaginary part) can be represented as the following equations.
[0000] [Equation 1]
[0000] Re{X low — mod ( k,n )}= Re{X ( k,n )}+α r,1 ( k )· Re{X ( k,n− 1)}+α r,2 ( k )· Re{X ( k,n− 2)} (1)
[0000] [Equation 2]
[0000] Im{X low — mod ( k,n )}= Im{X ( k,n )}α i,1 ( k )· Im{X ( k,n− 1)}+α i,2 ( k )· Im{X ( k,n− 2)} (2)
[0055] If the LPC analysis is performed on a frequency domain in low-frequency component data, a prediction gain of a stationary component is adequate. However, a prediction gain of low-frequency components other than the stationary component is not adequate. Accordingly, if the above-described equations of the inverse filter shown in the equation (1) and the equation (2) are used, only the stationary component whose prediction gain is adequate is removed from the low-frequency component data.
[0056] In the above-described description, it is assumed that the maximum order of the LPC coefficient is 2. However, the maximum order of the LPC coefficient can be 2 or more. Further, it is possible to remove the stationary component of the low-frequency component data only from a band where an average electric power of a frequency band of the low-frequency component data is equal to a threshold or more. Further, in the above description, it is assumed that the low-frequency component data is a complex number. However, in a case where the low-frequency component data is a real number, a similar processing can be performed only on a real part.
[0057] The high-frequency correction section 170 is a processing section that acquires a determination result from the transient characteristic detection section 150 . If the HE-AAC data has transient characteristics, the high-frequency correction section 170 corrects high-frequency component data based on a duration of the corrected low-frequency data. The high-frequency correction section 170 outputs the corrected high-frequency component data (corrected high-frequency data) to the synthesis filter section 180 . If the HE-AAC data does not have transient characteristics, the high-frequency correction section 170 directly outputs the high-frequency component data acquired from the high-frequency generation section 140 to the synthesis filter section 180 as corrected high-frequency data.
[0058] FIG. 5 is a view illustrating a configuration of the high-frequency correction section 170 . As illustrated in FIG. 5 , the high-frequency correction section 170 includes electric power calculation sections 171 and 172 , a correction coefficient calculation section 173 , and a correction coefficient multiplication section 174 .
[0059] The electric power calculation section 171 is a processing section that converts corrected high-frequency data acquired from the LPC inverse filter section 160 b into an electric power. An electric power E 1 converted by the electric power calculation section 171 can be represented as follows.
[0000] [Equation 3]
[0000] E 1 ( n,k )= Re{X low — mod ( n,k )} 2 +Im{X low — mod ( n,k )} 2 (3)
[0060] The electric power calculation section 171 outputs the converted electric power E 1 to the correction coefficient calculation section 173 .
[0061] The electric power calculation section 172 is a processing section that converts high-frequency component data acquired from the high-frequency generation section 140 into an electric power. An electric power E h converted by the electric power calculation section 172 can be represented as follows.
[0000] [Equation 4]
[0000] E h ( n,k )= Re{X high ( n,k )} 2 +Im{X high ( n,k )} 2 (4)
[0062] The electric power calculation section 172 outputs the converted electric power E h to the correction coefficient calculation section 173 . The electric powers E 1 and E h converted by the electric power calculation sections 171 and 172 are shown on a time-frequency axis as illustrated in FIG. 6 . FIG. 6 is a view illustrating the electric powers E 1 and E h on the time-frequency axis.
[0063] The correction coefficient calculation section 173 is a processing section that calculates a correction coefficient for correcting high-frequency component data based on the E 1 and E h acquired from the electric power calculation sections 171 and 172 . FIG. 7 is a view illustrating a method for calculating the correction coefficient.
[0064] As illustrated in FIG. 7 , if a low frequency exists only in time n, and high frequencies exist in the time n and time n+1, the electric power E 1 in the low frequency is not corrected. In the high frequencies, to match durations in the high frequencies with a duration in the low frequency, values of the electric powers in all time durations that exist before a correction are concentrated. An electric power E′ h (n,1) in the high frequency in a frequency band “1” after the correction can be represented as follows.
[0000] [Equation 5]
[0000] E′ h ( n, 1)= E h ( n, 1)+ E h ( n+ 1,1) (5)
[0065] An electric power E′ h (n+1,1) in the high frequency in the frequency band “1” after the correction can be represented as follows.
[0000] [Equation 6]
[0000] E′ h ( n+ 1,1)=0 (6)
[0066] Similarly, an electric power E′ h (n,2) in the high frequency in a frequency band “2” after the correction can be represented as follows.
[0000] [Equation 7]
[0000] E′ h ( n, 2)= E h ( n, 2)+ E h ( n+ 1,2) (7)
[0067] An electric power E′ h (n+1,2) in the high frequency in the frequency band “2” after the correction can be represented as follows.
[0000] [Equation 8]
[0000] E′ h ( n+ 1,2)=0 (8)
[0068] In the above description, the two durations n and n+1 are used. However, if two or more durations exist, a similar method for correcting an electric power in a high frequency can be employed.
[0069] The correction coefficient calculation section 173 calculates a correction coefficient gain using the electric power E h before correction and the electric power E′ h after correction according to the following equation.
[0000]
[Equation 9]
gain
(
n
,
k
)
=
E
h
′
(
n
,
k
)
E
h
(
n
,
k
)
(
9
)
[0070] The correction coefficient calculation section 173 outputs the calculated correction coefficient to the correction coefficient multiplication section 174 .
[0071] The correction coefficient multiplication section 174 is a processing section that acquires a correction coefficient from the correction coefficient calculation section 173 , multiplies a real part and an imaginary part in high-frequency component data acquired from the high-frequency generation section 140 by the correction coefficient, and generates corrected high-frequency data that is corrected data of the high-frequency component data. A real part and an imaginary part in the corrected high-frequency data can be represented as follows.
[0000] [Equation 10]
[0000] Re{X high — mod }=gain* Re{X high } (10)
[0000] [Equation 11]
[0000] Im{X high — mod }=gain* Im{X high } (11)
[0072] The correction coefficient multiplication section 174 outputs the corrected high-frequency data to the synthesis filter section 180 .
[0073] The synthesis filter section 180 is a processing section that synthesizes low-frequency component data acquired from the analysis filter section 130 with corrected high-frequency data acquired from the high-frequency correction section 170 and outputs the synthesized data as HE-AAC decoded audio data.
[0074] Now, a processing procedure performed in the decoder 100 according to the first embodiment is described. FIG. 8 is a flowchart illustrating a processing procedure performed in the decoder 100 according to the first embodiment of the present invention. As illustrated in FIG. 8 , in the decoder 100 , the data separation section 110 acquires HE-AAC data (step S 101 ), and separates the HE-AAC data into AAC data and SBR data (step S 102 ).
[0075] Then, the AAC decoding section 120 generates AAC output audio data from the AAC data (step S 103 ). The analysis filter section 130 generates low-frequency component data from the AAC output audio data (step S 104 ). The high-frequency generation section 140 generates high-frequency component data from the SBR data and the low-frequency component data (step S 105 ).
[0076] The transient characteristic detection section 150 determines whether the HE-AAC data has transient characteristics or not based on the AAC output audio data (step S 106 ). If the transient characteristic detection section 150 determines that the HE-AAC data has stationarity (step S 107 : NO), the processing proceeds to step S 111 .
[0077] On the other hand, if the transient characteristic detection section 150 determines that the HE-AAC data has transient characteristics (step S 107 : YES), the LPC analysis section 160 a performs an LPC analysis on the low-frequency component data, and calculates an LPC coefficient (step S 108 ). The LPC inverse filter section 160 b generates corrected low-frequency data based on the LPC coefficient (step S 109 ).
[0078] The high-frequency correction section 170 corrects the high-frequency component data and generates corrected high-frequency data (step S 110 ). The synthesis filter section 180 synthesizes the low-frequency component data with the corrected high-frequency data, generates HE-AAC decoded audio data (step S 111 ), and outputs the HE-AAC decoded audio data (step S 112 ).
[0079] As described above, the high-frequency correction section 170 corrects the high-frequency component data using the corrected low-frequency data from which the stationary component is removed. Accordingly, it can be prevented that the attack sound temporally extends, and deterioration in the sound quality of the audio signal can be prevented.
[0080] As described above, in the decoder 100 according to the first embodiment, if the transient characteristic detection section 150 determines that the HE-AAC data contains an attack sound, the LPC analysis section 160 a and the LPC inverse filter section 160 b remove a stationary component contained in the low-frequency component data. Then, the high-frequency correction section 170 generates corrected high-frequency data that is the data whose high-frequency component data is corrected to match with a duration of the corrected low-frequency component data. The synthesis filter section 180 synthesizes the low-frequency component data with the corrected high-frequency data and generates HE-AAC decoded audio data. Accordingly, if an audio signal that contains a sound source that has strong transient characteristics such as an attack sound is decoded, it can be prevented that the attack sound temporally extends, and deterioration in the sound quality of the audio signal can be prevented.
[0081] Further, in the decoder 100 according to the first embodiment, the high-frequency correction section 170 corrects high-frequency component data to match with a duration of corrected low-frequency data from which a stationary component of low-frequency component data is removed. Accordingly, it is possible to adjust a duration of the high-frequency component data to an optimal duration.
Second Embodiment
[0082] Now, a decoder according to a second embodiment of the present invention is described. The decoder according to the second embodiment determines whether an audio signal has transient characteristics or not based on window switch data contained in AAC data. It is assumed that the window switch data includes data of a determination result generated by an encoder for coding the audio signal by determining whether transient characteristics are contained in the audio signal or not.
[0083] Specifically, if the audio signal has transient characteristics, SHORT is set to window switch data. If the audio signal has stationarity, LONG is set to the window switch data. In AAC, the SHORT or LONG is set for each frame. Generally, in a case of a transient characteristic signal such as an attack sound, the SHORT is selected. In a state of the LONG, a temporal resolution is low, and in a state of the SHORT, the temporal resolution is high.
[0084] Accordingly, the decoder according to the second embodiment can determine whether an attack sound is contained in HE-AAC data by simply referring to the window switch data. Thus, it is not necessary to calculate an average electric power as described in the first embodiment, and processing loads of the decoder can be reduced.
[0085] Next, a configuration of the decoder according to the second embodiment is described. FIG. 9 is a view illustrating a configuration of a decoder 200 according to the second embodiment of the present invention. As illustrated in FIG. 9 , the decoder 200 includes a data separation section 210 , an AAC decoding section 220 , and an SBR decoding section 225 . The SBR decoding section 225 includes an analysis filter section 230 , a high-frequency generation section 240 , a transient characteristic detection section 250 , a stationarity removing section 260 , a high-frequency correction section 270 , and a synthesis filter section 280 .
[0086] Since the data separation section 210 , the analysis filter section 230 , the high-frequency generation section 240 , the high-frequency correction section 270 , and the synthesis filter section 280 are similar to the data separation section 110 , the analysis filter section 130 , the high-frequency generation section 140 , the high-frequency correction section 170 , and the synthesis filter section 180 illustrated in FIG. 2 , their descriptions are omitted.
[0087] The AAC decoding section 220 is a processing section that decodes AAC data acquired from the data separation section 210 , and outputs the decoded AAC output audio data to the analysis filter section 230 . Further, the AAC decoding section 220 extracts window switch data included in the decoded AAC data and outputs the extracted window switch data to the transient characteristic detection section 250 .
[0088] The transient characteristic detection section 250 is a processing section that acquires window switch data from the AAC decoding section 220 , determines whether the HE-AAC data has transient characteristics or not based on the acquired window switch data, and outputs the determination result to the high-frequency correction section 270 .
[0089] Specifically, if the SHORT is set to the window switch data, the transient characteristic detection section 250 determines that the HE-AAC data has transient characteristics. If the LONG is set to the window switch data, the transient characteristic detection section 250 determines that the HE-AAC data has stationarity.
[0090] The stationarity removing section 260 is a processing section that performs an LPC analysis on low-frequency component data, and generates corrected low-frequency data by removing a stationary component contained in a low-frequency component. Since the stationarity removing section 260 performs similar processings as those in the LPC analysis section 160 a and the LPC inverse filter section 160 b described in the first embodiment, a detailed description of the stationarity removing section 260 is omitted.
[0091] Now, a processing procedure performed in the decoder 200 according to the second embodiment is described. FIG. 10 is a flowchart illustrating a processing procedure performed in the decoder 200 according to the second embodiment of the present invention. As illustrated in FIG. 10 , in the decoder 200 , the data separation section 210 acquires HE-AAC data (step S 201 ), and separates the HE-AAC data into AAC data and SBR data (step S 202 ).
[0092] Then, the AAC decoding section 220 generates AAC output audio data from the AAC data (step S 203 ) The analysis filter section 230 generates low-frequency component data from the AAC output audio data (step S 204 ). The high-frequency generation section 240 generates high-frequency component data from the SBR data and the low-frequency component data (step S 205 ).
[0093] The transient characteristic detection section 250 determines whether a temporal resolution is the SHORT or the LONG based on window switch data (step S 206 ). If the transient characteristic detection section 250 determines that the temporal resolution is the LONG (step S 207 : NO), the processing proceeds to step S 211 .
[0094] On the other hand, if the transient characteristic detection section 250 determines that the temporal resolution is the SHORT (step S 207 : YES), the stationarity removing section 260 performs an LPC analysis on the low-frequency component data, and calculates an LPC coefficient (step S 208 ). The stationarity removing section 260 generates corrected low-frequency data based on the calculated LPC coefficient (step S 209 ).
[0095] The high-frequency correction section 270 corrects the high-frequency component data and generates corrected high-frequency data (step S 210 ). The synthesis filter section 280 synthesizes the low-frequency component data with the corrected high-frequency data, generates HE-AAC decoded audio data (step S 211 ), and outputs the HE-AAC decoded audio data (step S 212 ).
[0096] As described above, the transient characteristic detection section 250 determines whether HE-AAC data has transient characteristics or not based on window switch data. Accordingly, it is possible to reduce processing loads in the transient characteristic determination.
[0097] As described above, in the decoder 200 according to the second embodiment, the transient characteristic detection section 250 determines whether HE-AAC contains an attack sound based on window switch data. If the transient characteristic detection section 250 determines that the HE-AAC data contains the attack sound, the stationarity removing section 260 removes a stationary component contained in the low-frequency component data. Then, the high-frequency correction section 270 generates corrected high-frequency data that is data whose high-frequency component data is corrected to match with a duration of the corrected low-frequency component data. Further, the synthesis filter section 280 synthesizes the low-frequency component data with the corrected high-frequency data and generates HE-AAC decoded audio data. Accordingly, it is possible to reduce the processing loads in the transient characteristic determination. Further, if an audio signal that contains a sound source that has strong transient characteristics such as an attack sound is decoded, it can be prevented that the attack sound temporally extends, and deterioration in the sound quality of the audio signal can be prevented.
Third Embodiment
[0098] Now, a decoder according to a third embodiment of the present invention is described. If HE-AAC data (audio signal) contains an attack sound, depending on a position of the attack sound, a prediction gain in an PLC analysis may not be enough, and a stationary component in low-frequency component data may not be adequately removed. To solve the problem, the decoder according to the third embodiment divides a frame in the low-frequency component data into two sub-frames. Then, the decoder calculates LPC coefficients in the respective sub frames, the LPC coefficients are different from each other, and removes the stationary component in the low-frequency component data.
[0099] FIG. 11 is a view illustrating a configuration of a decoder 300 according to the third embodiment of the present invention. As illustrated in FIG. 11 , the decoder 300 includes a data separation section 310 , an AAC decoding section 320 , and an SBR decoding section 325 . The SBR decoding section 325 includes an analysis filter section 330 , a high-frequency generation section 340 , a transient characteristic detection section 350 , a stationarity removing section 360 , a high-frequency correction section 370 , and a synthesis filter section 380 .
[0100] Since the data separation section 310 , the analysis filter section 330 , the high-frequency generation section 340 , the high-frequency correction section 370 , and the synthesis filter section 380 are similar to the data separation section 110 , the analysis filter section 130 , the high-frequency generation section 140 , the high-frequency correction section 170 , and the synthesis filter section 180 illustrated in FIG. 2 , their descriptions are omitted. Further, since the AAC decoding section 320 and the transient characteristic detection section 350 are similar to the AAC decoding section 220 and the transient characteristic detection section 250 illustrated in FIG. 9 , their descriptions are omitted.
[0101] The stationarity removing section 360 is a processing section that divides a frame in low-frequency component data acquired from the analysis filter section 330 into two sub-frames. Then, the stationarity removing section 360 calculates LPC coefficients in the respective sub-frames, the LPC coefficients are different from each other, and generates corrected low-frequency data by removing stationary components in the low-frequency component data based on each LPC coefficient.
[0102] FIG. 12 is a view illustrating a processing performed in the stationarity removing section 360 according to the third embodiment of the present invention. When a current frame (frame in the low-frequency component data) is acquired, as illustrated in FIG. 12 , the stationarity removing section 360 divides the current frame into a first sub-frame and a second sub-frame.
[0103] Then, the stationarity removing section 360 , to the first sub-frame, generates a first residual signal by removing a stationary component from the first sub-frame using an LPC coefficient calculated in a previous frame (last frame acquired before the current frame). In order to calculate the residual signal using the LPC coefficient, low-frequency component data X low (0, k) to X low (N/2−1, k) (see FIG. 12 ) and the LPC coefficient of the previous frame are to be substituted into the equation (1) and the equation (2).
[0104] The stationarity removing section 360 , to the second sub-frame, generates a second residual signal from which a stationary component in the second sub-frame is removed by calculating an LPC coefficient in the current frame to low-frequency component data X low (N/2, k) to X low (N−1, k) in the current frame (see FIG. 12 ) and substituting the LPC coefficient of the current frame and the low-frequency component data X low (N/2, k) to X low (N−1, k) into the equation (1) and the equation (2).
[0105] The stationarity removing section 360 performs the above-described processing to all frequency bands in the low-frequency component data. A combination of the first residual signal and the second residual signal is to be corrected low-frequency data from which a stationary component is removed from the low-frequency component data. As described above, by removing a stationary component from divided first sub-frame and second sub-frame, even if a position of an attack sound is not at the first or the last of the frame (for example, at a center of the frame), an adequate prediction gain can be ensured. Accordingly, the stationarity of the low-frequency component data can be adequately removed.
[0106] Now, a processing procedure performed in the decoder 300 according to the third embodiment of the present invention is described. FIG. 13 is a flowchart illustrating a processing procedure performed in the decoder 300 according to the third embodiment of the present invention. As illustrated in FIG. 13 , in the decoder 300 , the data separation section 310 acquires HE-AAC data (step S 301 ), and divides the HE-AAC data into AAC data and SBR data (step S 302 ).
[0107] Then, the AAC decoding section 320 generates AAC output audio data from the AAC data (step S 303 ). The analysis filter section 330 generates low-frequency component data from the AAC output audio data (step S 304 ). The high-frequency generation section 340 generates high-frequency component data from the SBR data and the low-frequency component data (step S 305 ).
[0108] The transient characteristic detection section 350 determines whether a temporal resolution is the SHORT or the LONG based on window switch data (step S 306 ). If the transient characteristic detection section 350 determines that the temporal resolution is the LONG (step S 307 : NO), the processing proceeds to step S 312 .
[0109] On the other hand, if the transient characteristic detection section 350 determines that the temporal resolution is the SHORT (step S 307 : YES), the stationarity removing section 360 divides a frame in the low-frequency component data into a first sub-frame and a second sub-frame (step S 308 ). Then, the transient characteristic detection section 360 performs an LPC analysis on the second sub-frame, calculates an LPC coefficient in the second sub-frame (step S 309 ), and generates corrected low-frequency data (step S 310 ). To calculate an LPC coefficient of the first sub-frame, an LPC coefficient of a previous frame is used.
[0110] The high-frequency correction section 370 corrects the high-frequency component data and generates corrected high-frequency data (step S 311 ). The synthesis filter section 380 synthesizes the low-frequency component data with the corrected high-frequency data, generates HE-AAC decoded audio data (step S 312 ), and outputs the HE-AAC decoded audio data (step S 313 ).
[0111] As described above, stationarity removing section 360 divides a frame into the first sub-frame and the second sub-frame. In the first sub-frame, a stationary component is removed using an LPC coefficient of a previous frame. In the second sub-frame, the stationary component is removed using an LPC that is obtained as a result of an LPC analysis performed on the second sub-frame. Accordingly, it is possible to adequately remove the stationary component from the low-frequency component data wherever an attack sound exists.
[0112] As described above, in the decoder 300 according to the third embodiment, the transient characteristic detection section 350 determines whether HE-AAC data contains an attack sound based on window switch data. If the transient characteristic detection section 350 determines that the HE-AAC contains the attack sound, the stationarity removing section 360 divides a frame in the HE-AAC data into the first sub-frame and the second sub-frame, and removes a stationary component using LPC coefficients corresponding to each frame. Then, the high-frequency correction section 370 generates corrected high-frequency data that is data whose high-frequency component data is corrected to match with a duration of the corrected low-frequency component data. Further, the synthesis filter section 380 synthesizes the low-frequency component data with the corrected high-frequency data and generates HE-AAC decoded audio data. Accordingly, it is possible to adequately remove the stationary component in the low-frequency component data. Further, if an audio signal that contains a sound source that has strong transient characteristics such as an attack sound is decoded, it can be prevented that the attack sound temporally extends, and deterioration in the sound quality of the audio signal can be prevented.
Fourth Embodiment
[0113] Now, a decoder according to a fourth embodiment of the present invention is described. If a frame in low-frequency component data contains an attack sound, depending on a position (time) of the attack sound, a prediction gain in an PLC analysis may not be enough, and a stationary component in low-frequency component data may not be adequately removed. To solve the problem, the decoder according to the fourth embodiment detects the position of the attack sound in the frame, and divides the frame into a plurality of sub-frames based on the detected position. Then, the decoder performs a stationary removal using different LPC coefficients for the respective sub-frames.
[0114] As described above, the decoder according to the fourth embodiment detects the position of the attack sound in the frame in the low-frequency component data, and divides the frame into the plurality of sub-frames based on the detected position. Then, the decoder removes the stationary component using the different LPC coefficients for the respective sub-frames. Accordingly, it is possible to adequately remove the stationary component from the low-frequency component data wherever the attack sound exists.
[0115] FIG. 14 is a view illustrating a configuration of a decoder 400 according to the fourth embodiment of the present invention. As illustrated in FIG. 14 , the decoder 400 includes a data separation section 410 , an AAC decoding section 420 , and an SBR decoding section 425 . The SBR decoding section 425 includes an analysis filter section 430 , a high-frequency generation section 440 , a transient characteristic detection section 450 , a stationarity removing section 460 , a high-frequency correction section 470 , and a synthesis filter section 480 .
[0116] Since the data separation section 410 , the analysis filter section 430 , the high-frequency generation section 440 , the high-frequency correction section 470 , and the synthesis filter section 480 are similar to the data separation section 110 , the analysis filter section 130 , the high-frequency generation section 140 , the high-frequency correction section 170 , and the synthesis filter section 180 illustrated in FIG. 2 , their descriptions are omitted.
[0117] The AAC decoding section 420 decodes AAC data acquired from the data separation section 410 , and outputs the decoded ACC output audio data to the analysis filter section 430 . Further, the AAC decoding section 420 extracts window switch data and grouping data contained in the decoded AAC data, and outputs the window switch data and the grouping data to the transient characteristic detection section 450 .
[0118] The window switch data in the fourth embodiment is similar to that described in the second embodiment. The grouping data is used to detect a position of an attack sound. In the AAC, if the SHORT is set to the window switch data, further, one frame is divided into eight sub-frames. The grouping data indicates how to divide the frame. FIG. 15 is a view illustrating the grouping data.
[0119] For example, in FIG. 15 , if a changing point exists at a position of # 3 (if an attack sound exists at the position of # 3 ), the grouping data considers only the # 3 as one group (group 2 ), and considers preceding and following positions as the other groups (groups 1 and 3 ). Accordingly, using the grouping data, it is possible to determine that the attack sound exists at the changing point (in FIG. 15 , # 3 ).
[0120] The transient characteristic detection section 450 is a processing section that acquires window switch data and grouping data from the AAC decoding section 420 , determines whether HE-AAC data has transient characteristics based on the acquired window switch data, and outputs the determination result to the high-frequency correction section 470 . Further, if the transient characteristic detection section 450 determines that the HE-AAC has transient characteristics, based on the grouping data, the transient characteristic detection section 450 detects the position of the attack sound, and outputs information (hereinafter, referred to as attack sound position data) about the position of the attack sound to the stationarity removing section 460 .
[0121] The stationarity removing section 460 is a processing section that divides a frame in low-frequency component data acquired from the analysis filter section 430 based on a position of an attack sound, calculates LPC coefficients in the respective sub-frames, the LPC coefficients are different from each other, and generates corrected low-frequency data by removing a stationary component in the low-frequency component data based on each LPC coefficient.
[0122] FIG. 16 is a view illustrating a processing performed in the stationarity removing section 460 according to the fourth embodiment of the present invention. The stationarity removing section 460 acquires attack sound position data from the transient characteristic detection section 450 , and divides a current frame (frame in the low-frequency component data) into two sub-frames (first sub-frame and second sub-frame) at before and after the attack sound.
[0123] Then, the stationarity removing section 460 , to the first sub-frame, with respect to low-frequency component data X low (0,k) to X low (n,k) in a current frame, calculates an LPC coefficient in the current frame. Then, the stationarity removing section 460 generates a first residual signal by removing a stationary component from the first sub-frame by substituting the calculated LPC coefficient and low-frequency component data X low (0, k) to X low (n, k) into the equation (1) and the equation (2).
[0124] Then, the stationarity removing section 460 , to the second sub-frame, with respect to low-frequency component data X low (n+1,k) to X low (N−1,k) in a current frame, calculates an LPC coefficient in the current frame. Then, the stationarity removing section 460 generates a second residual signal by removing a stationary component from the second sub-frame by substituting the calculated LPC coefficient and the low-frequency component data X low (n+1, k) to X low (N−1,k) into the equation (1) and the equation (2).
[0125] The stationarity removing section 460 performs the above-described processing to all frequency bands in the low-frequency component data. A combination of the first residual signal and the second residual signal is to be corrected low-frequency data from which the stationary component is removed from the low-frequency component data. As described above, by removing the stationary component from the divided first sub-frame and second sub-frame, even if the position of the attack sound varies, an adequate prediction gain can be ensured. Accordingly, the stationarity of the low-frequency component data can be adequately removed.
[0126] In the fourth embodiment, the stationarity removing section 460 divides a frame into two sub-frames at before and after an attack sound. However, it is possible to divide the frame into three or more sub-frames, calculate LPC coefficients for each sub-frame, and remove a stationary component.
[0127] Now, a processing procedure performed in the decoder 400 according to the fourth embodiment of the present invention is described. FIG. 17 is a flowchart illustrating a processing procedure performed in the decoder 400 according to the fourth embodiment of the present invention. As illustrated in FIG. 17 , in the decoder 400 , the data separation section 410 acquires HE-AAC data (step S 401 ), and divides the HE-AAC data into AAC data and SBR data (step S 402 ).
[0128] Then, the AAC decoding section 420 generates AAC output audio data from the AAC data (step S 403 ), and outputs window switch data and grouping data (step S 404 ). The analysis filter section 430 generates low-frequency component data from the AAC output audio data (step S 405 ).
[0129] The high-frequency generation section 440 generates high-frequency component data from the SBR data and the low-frequency component data (step S 406 ). The transient characteristic detection section 450 determines whether a temporal resolution is the SHORT or the LONG based on the window switch data (step S 407 ). If the transient characteristic detection section 450 determines that the temporal resolution is the LONG (step S 408 : NO), the processing proceeds to step S 413 .
[0130] On the other hand, if the transient characteristic detection section 450 determines that the temporal resolution is the SHORT (step S 408 : YES), the stationarity removing section 460 divides a frame in the low-frequency component data into a first sub-frame and a second sub-frame based on the position of the attack sound (step S 409 ). Then, the transient characteristic detection section 460 performs LPC analyses on each sub-frame, calculates LPC coefficients in each second sub-frame (step S 410 ), and generates corrected low-frequency data (step S 411 ).
[0131] The high-frequency correction section 470 corrects the high-frequency component data and generates corrected high-frequency data (step S 412 ). The synthesis filter section 480 synthesizes the low-frequency component data with the corrected high-frequency data, generates HE-AAC decoded audio data (step S 413 ), and outputs the HE-AAC decoded audio data (step S 414 ).
[0132] As described above, the stationarity removing section 460 divides a frame into the first sub-frame and the second sub-frame based on a position of an attack sound, and a stationary component is removed using different LPC coefficients for each sub-frame. Accordingly, it is possible to adequately remove the stationary component wherever the attack sound exists.
[0133] As described above, if HE-AAC data contains an attack sound, in the decoder 400 according to the fourth embodiment, the stationarity removing section 460 divides low-frequency component data into the first sub-frame and the second sub-frame based on a position of the attack sound, and removes a stationary component using LPC coefficients corresponding to each frame. Then, the high-frequency correction section 470 generates corrected high-frequency data that is data whose high-frequency component data is corrected to match with a duration of the corrected low-frequency component data. The synthesis filter section 480 synthesizes the low-frequency component data with the corrected high-frequency data and generates HE-AAC decoded audio data. Accordingly, it is possible to adequately remove the stationary component in the low-frequency component data wherever the attack sound exists. Further, if an audio signal that contains a sound source that has strong transient characteristics such as an attack sound is decoded, it can be prevented that the attack sound temporally extends, and deterioration in the sound quality of the audio signal can be prevented.
[0134] In the above-described first to fourth embodiments, using the LPC inverse filter (short-term prediction inverse filter), a stationary component contained in low-frequency component data is removed. However, it is not limited to the above, for example, a long-term prediction inverse filter can be used instead of the LPC inverse filter. Further, the stationary component in the low-frequency component data can be removed by a combination of the LPC inverse filter and the long-term prediction inverse filter.
[0135] In the processings described in the above embodiments, all or a part of the processings that have been described to be automatically performed can be manually performed. Further, all or a part of the above-described processings to be manually performed can be automatically performed using a known method. Further, the processing procedures, the control procedures, the specific names, the various data, the information including parameters described in the above descriptions and drawings can be changed if not otherwise specified.
[0136] Further, each structural element in the decoders 100 to 400 illustrated in FIGS. 2 , 9 , 11 , and 14 are described in a functional concept. Accordingly, it is not necessary to physically configure the structural elements as illustrated in the drawings. That is, specific embodiments in distribution and integration of each section are not limited to the illustrated embodiments, all or a part of the sections can be functionally or physically distributed or integrated in any unit depending on various loads and usage conditions. Further, all or a part of each processing function performed in each section can be realized by a central processing unit (CPU) and a program that is analyzed and implemented in the CPU, or hardware by a wired logic.
[0137] FIG. 18 is a flowchart illustrating a hardware configuration of a computer that forms the decoders according to the first to fourth embodiments of the present invention. As illustrated in FIG. 18 , a computer (decoder) 500 includes an input device 501 that receives data such as HE-AAC data, a monitor 502 , a random access memory (RAM) 503 , a read only memory (ROM) 504 , a medium read device 505 that reads data from a storage medium, a network interface 506 that transmits/receives data to/from another device, a CPU 507 , a hard disk drive (HDD), and a bus 509 . These elements are connected by the bus 509 . Furthermore, the computer (decoder) 500 includes a speaker for outputting the regenerated audio signal.
[0138] The HDD 508 stores a decode program 508 b that performs similar functions to the above-described decoders 100 to 400 . When the CPU 507 reads and executes the decode program 508 b , a decode process 507 a is initiated. The decode process 507 a corresponds to the data separation sections 110 , 210 , 310 , and 410 , the AAC decoding sections 120 , 220 , 320 , and 420 , and the SBR decoding sections 125 , 225 , 325 , and 425 .
[0139] Further, the HDD 508 stores HE-AAC data 508 a that is acquired by the input device 501 , or the like. The CPU 507 reads the HE-AAC data 508 a stored in the HDD 508 and stores the data in the RAM 503 . The HDD 508 used the HE-AAC data 503 a stored in the RAM 503 to decode, and store HE-AAC decoded audio data 503 b in the RAM 503 .
[0140] It is not necessary to store the decode program 508 b illustrated in FIG. 18 in the HDD 508 in advance. For example, the decode program 508 b can be stored in a “portable physical medium” such as a flexible disk (FD), a compact disc read only memory (CD-ROM), a Digital Versatile Disc (DVD), a magnetic optical disk, and normalized activity integrated circuit card (IC card) that are to be inserted into a computer, a “fixable physical medium” such as a HDD that is provided inside or outside of the computer, or “another computer (or server)” that is connected to the computer via a public line, the Internet, a local area network (LAN), or a wide area network (WAN). The computer can read the decode program 508 b from these media and implement the program.
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According to an aspect of an embodiment, a method for regenerating an audio signal including a low frequency component and a high frequency component by decoding a coded data including a first coded data and a second coded data, the method comprising the steps of: generating the low frequency component; generating the high frequency component; determining whether the low frequency component has transient characteristics or not; generating a low frequency correction component by removing a stationary component when the audio signal has the transient characteristics; generating a corrected high frequency component by correcting the high-frequency component on the basis of the duration of the low frequency correction component when the audio signal has the transient characteristics; and regenerating the audio signal by synthesizing the low frequency component with the corrected high-frequency component.
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CROSS REFERENCE TO RELATED APPLICATIONS
This application is a Divisional Application of U.S. patent application Ser. No. 10/202,243, filed Jul. 24, 2002 now U.S. Pat. No. 7,079,900, which is a Divisional Application of U.S. patent application Ser. No. 09/515,373, filed Feb. 29, 2000 now abandoned, which claims the benefit of U.S. Provisional Application No. 60/125,873, filed Mar. 24, 1999.
TECHNICAL FIELD OF INVENTION
The present invention relates to electrical stimulation of the retina to produce artificial images for the brain. It relates to electronic image stabilization techniques based on tracking the movements of the eye. It relates to telemetry in and out of the eye for uses such as remote diagnostics and recording from the retinal surface.
The present invention also relates to electrical stimulation of the retina to produce phosphenes and to produce induced color vision. The present invention relates to hermetically sealed electronic and electrode units which are safe to implant in the eye.
BACKGROUND
Color perception is part of the fabric of human experience. Homer (c. 1100 b. c.) writes of “the rosy-fingered dawn”. Lady Murasaki no Shikibu (c. 1000 a.d.) uses word colors (“purple, yellow shimmer of dresses, blue paper”) in the world's first novel. In the early nineteenth century Thomas Young, an English physician, proposed a trichromatic theory of color vision, based on the action of three different retinal receptors. Fifty years later James Clerk Maxwell, the British physicist and Hermann von Helmholtz, the German physiologist, independently showed that all of the colors we see can be made up from three suitable spectral color lights. In 1964 Edward MacNichol and colleagues at Johns Hopkins and George Wald at Harvard measured the absorption by the visual pigments in cones, which are the color receptor cells. Rods are another type of photoreceptor cell in the primate retina. These cells are more sensitive to dimmer light but are not directly involved in color perception. The individual cones have one of three types of visual pigment. The first is most sensitive to short waves, like blue. The second pigment is most sensitive to middle wavelengths, like green. The third pigment is most sensitive to longer wavelengths, like red.
The retina can be thought of a big flower on a stalk where the top of that stalk is bent over so that the back of the flower faces the sun. In place of the sun, think of the external light focused by the lens of the eye onto the back of the flower. The cones and rods cells are on the front of the flower; they get the light which has passed through from the back of the somewhat transparent flower. The photoreceptor nerve cells are connected by synapses to bipolar nerve cells, which are then connected to the ganglion nerve cells. The ganglion nerve cells connect to the optic nerve fibers, which is the “stalk”that carries the information generated in the retina to the brain. Another type of retinal nerve cell, the horizontal cell, facilitates the transfer of information horizontally across bipolar cells. Similarly, another type of cell, the amacrine facilitates the horizontal transfer of information across the ganglion cells. The interactions among the retinal cells can be quite complex. On-center and off-center bipolar cells can be stimulated at the same time by the same cone transmitter release to depolarize and hyperpolarize, respectively. A particular cell's receptive field is that part of the retina, which when stimulated, will result in that cell's stimulation. Thus, most ganglion cells would have a larger receptive field than most bipolar cells. Where the response to the direct light on the center of a ganglion cells receptive field is antagonized by direct light on the surround of its receptive field, the effect is called center-surround antagonism. This phenomenon is important for detecting borders independent of the level of illumination. The existence of this mechanism for sharpening contrast was first suggested by the physicist Ernst Mach in the late 1800's. More detailed theories of color vision incorporate color opponent cells. On the cone level, trichromatic activity of the cone cells occurs. At the bipolar cell level, green-red opponent and blue-yellow opponent processing systems of the center-surround type, occur. For example, a cell with a green responding center would have a annular surround area, which responded in an inhibiting way to red. Similarly there can be red-center responding, green-surround inhibiting response. The other combinations involve blue and yellow in an analogous manner.
It is widely known that Galvani, around 1780, stimulated nerve and muscle response electrically by applying a voltage on a dead frog's nerve. Less well known is that in 1755 LeRoy discharged a Leyden jar, i.e., a capacitor, through the eye of a man who had been blinded by the growth of a cataract. The patient saw “flames passing rapidly downward.”
In 1958, Tassicker was issued a patent for a retinal prosthetic utilizing photosensitive material to be implanted subretinally. In the case of damage to retinal photoreceptor cells that affected vision, the idea was to electrically stimulate undamaged retinal cells. The photosensitive material would convert the incoming light into an electrical current, which would stimulate nearby undamaged cells. This would result in some kind of replacement of the vision lost. Tassicker reports an actual trial of his device in a human eye. (U.S. Pat. No. 2,760,483).
Subsequently, Michelson (U.S. Pat. No. 4,628,933), Chow (U.S. Pat. Nos. 5,016,633; 5,397,350; 5,556,423), and De Juan (U.S. Pat. No. 5,109,844) all were issued patents relating to a device for stimulating undamaged retinal cells. Chow and Michelson made use of photodiodes and electrodes. The photodiode was excited by incoming photons and produced a current at the electrode.
Normann et al. (U.S. Pat. No. 5,215,088) discloses long electrodes 1000 to 1500 microns long designed to be implanted into the brain cortex. These spire-shaped electrodes were formed of a semiconductor material.
Najafi, et al., (U.S. Pat. No. 5,314,458), disclosed an implantable silicon-substrate based microstimulator with an external device which could send power and signal to the implanted unit by RF means. The incoming RF signal could be decoded and the incoming RF power could be rectified and used to run the electronics.
Difficulties can arise if the photoreceptors, the electronics, and the electrodes all tend to be mounted at one place. One issue is the availability of sufficient area to accommodate all of the devices, and another issue is the amount of power dissipation near the sensitive retinal cells. Since these devices are designed to be implanted into the eye, this potential overheating effect is a serious consideration.
Since these devices are implants in the eye, a serious problem is how to hermetically seal these implanted units. Of further concern is the optimal shape for the electrodes and for the insulators, which surround them. In one embodiment there is a definite need that the retinal device and its electrodes conform to the shape of the retinal curvature and at the same time do not damage the retinal cells or membranes.
The length and structure of electrodes must be suitable for application to the retina, which averages about 200 microns in thickness. Based on this average retinal thickness of 200 microns, elongated electrodes in the range of 100 to 500 microns appear to be suitable. These elongated electrodes reach toward the cells to be activated. Being closer to the targeted cell, they require less current to activate it.
In order not to damage the eye tissue there is a need to maintain an average charge neutrality and to avoid introducing toxic or damaging effects from the prosthesis.
A desirable property of a retinal prosthetic system is making it possible for a physician to make adjustments on an on-going basis from outside the eye. One way of doing this would have a physician's control unit, which would enable the physician to make adjustments and monitor the eye condition. An additional advantageous feature would enable the physician to perform these functions at a remote location, e.g., from his office. This would allow one physician to remotely monitor a number of patients remotely without the necessity of the patient coming to the office. A patient could be traveling distantly and obtain physician monitoring and control of the retinal color prosthetic parameters.
Another version of the physician's control unit is a hand-held, palm-size unit. This unit will have some, but not all of the functionality of the physician's control unit. It is for the physician to carry on his rounds at the hospital, for example, to check on post-operative retinal-prosthesis implant patients. Its extreme portability makes other situational uses possible, too, as a practical matter.
The patient will want to control certain aspects of the visual image from the retinal prosthesis system, in particular, image brightness. Consequently, a patient controller, performing fewer functions than the physician's controller is included as part of the retinal prosthetic system. It will control, at a minimum, bright image, and it will control this image brightness in a continuous fashion. The image brightness may be increased or decreased by the patient at any time, under normal circumstances.
A system of these components would itself constitute part of a visual prosthetic to form images in real time within the eye of a person with a damaged retina. In the process of giving back sight to those who are unable to see, it would be advantageous to supply artificial colors in this process of reconstructing sight so that the patient would be able to enjoy a much fuller version of the visual world.
In dealing with externally mounted or externally placed means for capturing image and transmitting it by electronic means or other into the eye, one must deal with the problem of stabilization of the image. For example, a head-mounted camera would not follow the eye movement. It is desirable to track the eye movements relative to the head and use this as a method or approach to solving the image stabilization problem.
By having a method and apparatus for the physician and the technician to initially set up and measure the internal activities and adjust these, the patient's needs can be better accommodated. The opportunity exists to measure internal activity and to allow the physician, using his judgment, to adjust settings and controls on the electrodes. Even the individual electrodes would be adjusted by way of the electronics controlling them. By having this done remotely, by remote means either by telephone or by the Internet or other such, it is clear that a physician would have the capability to intervene and make adjustment as necessary in a convenient and inexpensive fashion, to serve many patients.
SUMMARY OF INVENTION
The objective of the current invention is to restore color vision, in whole or in part, by electrically stimulating undamaged retinal cells, which remain in patients with lost or degraded visual function arising, for example, from Retinitis Pigmentosa or Age-Related Macular Degeneration. This invention is directed toward patients who have been blinded by degeneration of photoreceptors; but who have sufficient bipolar cells, or other cells acting similarly, to permit electrical stimulation.
There are three main functional parts to this invention. One is external to the eye. The second part is internal to the eye. The third part is the communication circuitry for communicating between those two parts. Structurally there are two parts. One part is external to the eye and the other part in implanted within the eye. Each of these structural parts contains two way communication circuitry for communication between the internal and external parts.
The structural external part is composed of a number of subsystems. These subsystems include an external imager, an eye-motion compensation system, a head motion compensation system, a video data processing unit, a patient's controller, a physician's local controller, a physician's remote controller, and a telemetry unit. The imager is a video camera such as a CCD or CMOS video camera. It gathers an image approximating what the eyes would be seeing if they were functional.
The imager sends an image in the form of electrical signals to the video data processing unit. In one aspect, this unit formats a grid-like or pixel-like pattern that is then ultimately sent to electronic circuitry (part of the internal part) within the eye, which drives the electrodes. These electrodes are inside the eye. They replicate the incoming pattern in a useable form for stimulation of the retina so as to reproduce a facsimile of the external scene. In an other aspect of this invention other formats other than a grid-like or pixel like pattern are used, for example a line by line scan in some order, or a random but known order, point-by-point scan. Almost any one-to-one mapping between the acquired image and the electrode array is suitable, as long as the brain interprets the image correctly.
The imager acquires color information. The color data is processed in the video data processing unit. The video data processing unit consists of microprocessor CPU'sand associated processing chips including high-speed data signal processing (DSP) chips.
In one aspect, the color information is encoded by time sequences of pulses separated by varying amounts of time; and, the pulse duration may be different for various pulses. The basis for the color encoding is the individual color code reference ( FIG. 2 a ). The electrodes stimulate the target cells so as to create a color image for the patient, corresponding to the original image as seen by the video camera, or other imaging means.
Color information, in an alternative aspect, is sent from the video data processing unit to the electrode array, where each electrode has been determined to stimulate preferentially one of the bipolar cell types, namely, red-center green-surround, green-center-red-surround, blue-center-yellow-surround, or yellow-center-blue-surround.
An eye-motion compensation system is an aspect of this invention. The eye tracker is based on detection of eye motion from the corneal reflex or from implanted coils of wire, or, more generally, insulated conductive coils, on the eye or from the measurement of electrical activity of extra-ocular muscles. Communication is provided between the eye tracker and the video data processing unit by electromagnetic or acoustical telemetry. In one embodiment of the invention, electromagnetic-based telemetry may be used. The results of detecting the eye movement are transmitted to a video data processing unit, together with the information from the camera means. Another aspect of the invention utilizes a head motion sensor and head motion compensation system. The video data processing unit can incorporate the data of the motion of the eye as well as that of the head to further adjust the image electronically so as to account for eye motion and head motion.
The internal structural part which is implanted internally within the eye, is also composed of a number of subsystems. These can be categorized as electronic circuits and electrode arrays, and communication subsystems, which may include electronic circuits. The circuits, the communication subsystems, and the arrays can be hermetically sealed and they can be attached one to the other by insulated wires. The electrode arrays and the electronic circuits can be on one substrate, or they may be on separate substrates joined by an insulated wire or by a plurality of insulated wires. This is similarly the case for a communication subsystem.
A plurality of predominately electronic substrate units and a plurality of predominately electrode units may be implanted or located within the eye as desired or as necessary. The electrodes are designed so that they and the electrode insulation conform to the retinal curvature. The variety of electrode arrays include recessed electrodes so that the electrode array surface coming in contact with the retinal membrane or with the retinal cells is the non-metallic, more inert insulator.
Another aspect of the invention is the elongated electrode, which is designed to stimulate deeper retinal cells by penetrating into the retina by virtue of the length of its electrodes. A plurality of electrodes is used. The elongated electrodes are of lengths from 100 microns to 500 microns. With these lengths, the electrode tips can reach through those retinal cells not of interest but closer to the target stimulation cells, the bipolar cells. The number of electrodes may range from 100 on up to 10,000 or more. With the development of electrode fabrication technology, the number of electrodes might rage up to one million or more.
Another aspect of the invention uses a plurality of capacitive electrodes to stimulate the retina, in place of non-capacitive electrodes. Another aspect of the invention is the use of a neurotrophic factor, for example, Nerve Growth Factor, applied to the electrodes, or to the vicinity of the electrodes, to aid in attracting target nerves and other nerves to grow toward the electrodes.
Hermetic sealing is accomplished by coating the object to be sealed with a substance selected from the group consisting of silicon carbide, diamond-like coating, silicon nitride and silicon oxide in combination, titanium oxide, tantalum oxide, aluminum nitride, aluminum oxide, zirconium oxide. This hermetic sealing aspect of the invention provides an advantageous alternative to glass coverings for hermetic seals, being less likely to become damaged.
Another feature of one aspect of the structural internal-to-the-eye subsystems is that the electronics receive and transmit information in coded or pulse form via electromagnetic waves. In the case where electromagnetic waves are used, the internal-to-the-eye implanted electronics can rectify the RF, or electromagnetic wave, current and decode it. The power being sent in through the receiving coil is extracted and used to drive the electronics. In some instances, the implanted electronics acquire data from the electrode units to transmit out to the video data processing unit.
In another aspect the information coding is done with ultrasonic sound. An ultrasonic transducer replaces the electromagnetic wave receiving coil inside the eye. An ultrasonic transducer replaces the coil outside the eye for the ultrasonic case. By piezoelectric effects, the sound vibration is turned into electrical current, and energy extracted therefrom.
In another aspect of the invention, information is encoded by modulating light. For the light modulation case, a light emitting diode (LED) or laser diode or other light generator, capable of being modulated, acts as the information transmitter. Information is transferred serially by modulating the light beam, and energy is extracted from the light signal after it is converted to electricity. A photo-detector, such as a photodiode, which turns the modulated light signal into a modulated electrical signal, is used as a receiver.
Another aspect of the structural internal-to-the-eye subsystems of this invention is that the predominately electrode array substrate unit and the predominately electronic substrate unit, which are joined by insulated wires, can be placed near each other or indifferent positions. For example, the electrode array substrate unit can be placed subretinally and the electronic substrate unit placed epiretinally. On a further aspect of this invention, the electronic substrate unit can be placed distant from the retina so as to avoid generating additional heat or decreasing the amount of heat generated near the retinal nerve system. For example, the receiving and processing circuitry could be placed in the vicinity of the pars plana. In the case where the electronics and the electrodes are on the same substrate chip, two of these chips can be placed with the retina between them, one chip subretinal and the other chip epiretinal, such that the electrodes on each may be aligned. Two or more guide pins with corresponding guide hole or holes on the mating chip accomplish the alignment. Alternatively, two or more tiny magnets on each chip, each magnet of the correct corresponding polarity, may similarly align the sub- and epiretinal electrode bearing chips. Alternatively, corresponding parts which mate together on the two different chips and which in a fully mated position hold each other in a locked or “snap-together” relative position.
Now as an element of the external-to-the-eye structural part of the invention, there is a provision for a physician's hand-held test unit and a physician's local or remote office unit or both for control of parameters such as amplitudes, pulse widths, frequencies, and patterns of electrical stimulation.
The physician's hand-held test unit can be used to set up or evaluate and test the implant during or soon after implantation at the patient's bedside. It has, essentially, the capability of receiving what signals come out of the eye and having the ability to send information in to the retinal implant electronic chip. For example, it can adjust the amplitudes on each electrode, one at a time, or in groups. The hand-held unit is primarily used to initially set up and make a determination of the success of the retinal prosthesis.
The physician's local office unit, which may act as a set-up unit as well as a test unit, acts directly through the video data processing unit. The remote physician's office unit would act over the telephone lines directly or through the Internet or a local or wide area network. The office units, local and remote, are essentially the same, with the exception that the physician's remote office unit has the additional communications capability to operate from a location remote from the patient. It may evaluate data being sent out by the internal unit of the eye, and it may send in information. Adjustments to the retinal color prosthesis may be done remotely so that a physician could handle a multiple number of units without leaving his office. Consequently this approach minimizes the costs of initial and subsequent adjustments.
BRIEF DESCRIPTION OF THE DRAWINGS
The above and other features and advantages of the invention will be more apparent from the following detailed description wherein:
FIG. 1 a shows the general structural aspects of the retina color prosthesis system;
FIG. 1 b shows the retina color prosthesis system with a structural part internal (to the eye), with an external part with subsystems for eye-motion feedback to enable maintaining a stable image presentation, and with a subsystems for communicating between the internal and external parts, and other structural subsystems;
FIG. 1 c shows an embodiment of the retina color prosthesis system which is, in part, worn in eyeglass fashion;
FIG. 1 d shows the system in FIG. 1 c in side view;
FIG. 2 a shows an embodiment of the color I coding schemata for the stimulation of the sensation of color;
FIG. 2 b represents an embodiment of the color I conveying method where a “large” electrode stimulates many bipolar cells with the color coding schemata of FIG. 2 a;
FIG. 2 c represents an embodiment of the color II conveying method where an individual electrode stimulates a single type of bipolar cell;
FIG. 3 a represents an embodiment of the telemetry unit including an external coil, an internal (to the eye) coil, and an internal electronic chip;
FIG. 3 b represents an embodiment of the telemetry unit including an external coil, an internal (to the eye) coil, an external electronic chip, a dual coil transfer unit, and an internal electrode array;
FIG. 3 c shows and acoustic energy and information transfer system;
FIG. 3 d shows a light energy and information transfer system;
FIG. 4 represents an embodiment of the external telemetry unit;
FIG. 5 shows an embodiment of an internal telemetry circuit and electrode array switcher;
FIG. 6 a shows a monopolar electrode arrangement and illustrates a set of round electrodes on a substrate material;
FIG. 6 b shows a bipolar electrode arrangement;
FIG. 6 c shows a multipolar electrode arrangement;
FIG. 7 shows the corresponding indifferent electrode for monopolar electrodes;
FIG. 8 a depicts the location of an epiretinal electrode array located inside the eye in the vitreous humor located above the retina, toward the lens capsule and the aqueous humor;
FIG. 8 b shows recessed epiretinal electrodes where the electrically conducting electrodes are contained within the electrical insulation material; a silicon chip acts as a substrate; and the electrode insulator device is shaped so as to contact the retina in a conformal manner;
FIG. 8 c is a rendering of an elongated epiretinal electrode array with the electrodes shown as pointed electrical conductors, embedded in an electrical insulator, where an pointed electrodes contact the retina in a conformal manner, however, elongated into the retina;
FIG. 9 a shows the location of a subretinal electrode array below the retina, away from the lens capsule and the aqueous humor. The retina separates the subretinal electrode array from the vitreous humor;
FIG. 9 b illustrates the subretinal electrode array with pointed elongated electrode, the insulator, and the silicon chip substrate where the subretinal electrode array is in conformal contact with the retina with the electrodes elongated to some depth;
FIG. 10 a shows a iridium electrode that comprises a iridium slug, an insulator, and a device substrate where this embodiment shows the iridium slug electrode flush with the extent of the insulator;
FIG. 10 b indicates an embodiment similar to that shown in FIG. 10 / 12 a , however, the iridium slug is recessed from the insulator along its sides, but with its top flush with the insulator;
FIG. 10 c shows an embodiment with the iridium slug as in FIG. 10 / 12 b ; however, the top of the iridium slug is recessed below the level of the insulator;
FIG. 10 d indicates an embodiment with the iridium slug coming to a point and insulation along its sides, as well as a being within the overall insulation structure;
FIG. 10 e indicates an embodiment of a method for fabricating and the fabricated iridium electrode where on a substrate of silicon an aluminum pad is deposited; on the pad the conductive adhesive is laid and platinum or iridium foil is attached thereby; a titanium ring is placed, sputtered, plated, ion implanted, ion beam assisted deposited (IBAD) or otherwise attached to the platinum or iridium foil; silicon carbide, diamond-like coating, silicon nitride and silicon oxide in combination, titanium oxide, tantalum oxide, aluminum nitride, aluminum oxide or zirconium oxide or other insulator will adhere better to the titanium while it would not adhere as well to the platinum or iridium foil;
FIG. 11 a depicts a preferred electrode where it is formed on a silicon substrate and makes use of an aluminum pad, a metal foil such as platinum or iridium, conductive adhesive, a titanium ring, aluminum or zirconium oxide, an aluminum layer, and a mask;
FIG. 11 b shows an elongated electrode formed on the structure of FIG. 11 a with platinum electroplated onto the metal foil, the mask removed and insulation applied over the platinum electrode;
FIG. 11 c shows a variation of a form of the elongated electrode wherein the electrode is thinner and more recessed from the well sides;
FIG. 11 d shows a variation of a form of the elongated electrode wherein the electrode is squatter but recessed from the well sides;
FIG. 11 e shows a variation of a form of the elongated electrode wherein the electrode is a mushroom shape with the sides of its tower recessed from the well sides and its mushroom top above the oxide insulating material;
FIG. 12 a shows the coil attachment to two different conducting pads at an electrode node;
FIG. 12 b shows the coil attachment to two different conducting pads at an electrode node, together with two separate insulated conducting electrical pathways such as wires, each attached at two different electrode node sites on two different substrates;
FIG. 12 c shows an arrangement similar to that seen in FIG. 12 / 16 d , with the difference that the different substrates are very close with a non-conducting adhesive between them and an insulator such as aluminum or zirconium oxide forms a connection coating over the two substrates, in part;
FIG. 12 d depicts an arrangement similar to that seen in FIG. 12 / 16 c ; however, the connecting wires are replaced by an externally placed aluminum conductive trace;
FIG. 13 shows a hermetically sealed flip-chip in a ceramic or glass case with solder ball connections to hermetically sealed glass frit and metal leads;
FIG. 14 shows a hermetically sealed electronic chip as in FIG. 18 with the addition of biocompatible leads to pads on a remotely located electrode substrate;
FIG. 15 shows discrete capacitors on the electrode-opposite side of an electrode substrate;
FIG. 16 a shows an electrode-electronics retinal implant placed with the electrode half implanted beneath the retina, subretinally, while the electronics half projects above the retina, epiretinally;
FIG. 16 b shows another form of sub- and epi-retinal implantation wherein half of the electrode implant is epiretinal and half is subretinal;
FIG. 16 c shows the electrode parts are lined up by alignment pins or by very small magnets;
FIG. 16 d shows the electrode part lined up by template shapes which may snap together to hold the parts in a fixed relationship to each other;
FIG. 17 a shows the main screen of the physician's (local) controller (and programmer);
FIG. 17 b illustrates the pixel selection of the processing algorithm with the averaging of eight surrounding pixels chosen as one element of the processing;
FIG. 17 c represents an electrode scanning sequence, in this case the predefined sequence, A;
FIG. 17 d shows electrode parameters, here for electrode B, including current amplitudes and waveform timelines;
FIG. 17 e illustrates the screen for choosing the global electrode configuration, monopolar, bipolar, or multipolar;
FIG. 17 f renders a screen showing the definition of bipolar pairs (of electrodes);
FIG. 17 g shows the definition of the multipole arrangements;
FIG. 18 a illustrates the main menu screen for the palm-sized test unit;
FIG. 18 b shows a result of pressing on the stimulate bar of the main menu screen, where upon pressing the start button the amplitudes A 1 and A 2 are stimulated for times t 1 , t 2 , t 3 , and t 4 , until the stop button is pressed;
FIG. 18 c exhibits a recording screen that shows the retinal recording of the post-stimulus and the electrode impedance;
FIG. 19 shows the physician's remote controller that has the same functionality inside as the physician's controller but with the addition of communication means such as telemetry or telephone modem; and
FIG. 20 shows the patient's controller unit.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
The following description is of the best mode presently contemplated for carrying out the invention. This description is not to be taken in a limiting sense, but is merely made for the purpose of describing the general principles of the invention. The scope of the invention should be determined with reference to the claims.
Objective
The objective of the embodiments of the current invention is a retinal color prosthesis to restore color vision, in whole or in part, by electrically stimulating undamaged retinal cells, which remain in patients with, lost or degraded visual function. Embodiments of this retinal color prosthesis invention are directed toward helping patients who have been blinded by degeneration of photoreceptors and other cells; but who have sufficient bipolar cells and the like to permit the perception of color vision by electric stimulation. By color vision, it is meant to include black, gray, and white among the term color.
General Description
Functionally, there are three main parts to an embodiment of this retinal color prosthesis invention. See FIG. 1 a . FIG. 1 a is oriented toward showing the main structural parts and subsystems, with a dotted enclosure to indicate a functional intercommunications aspect. The first part of the embodiment is external ( 1 ) to the eye. The second part is implanted internal ( 2 ) to the eye. The third part is means for communication between those two parts ( 3 ). Structurally there are two parts. One part is external ( 1 ) to the eye and the other part ( 2 ) is implanted within the eye. Each of these structural parts contains two way communication circuitry for communication ( 3 )between the internal ( 2 ) and external ( 1 ) parts.
The external part of the retinal color prosthesis is carried by the patient. Typically, the external part including imager, video data processing unit, eye-tracker, and transmitter/receiver are worn as an eyeglass-like unit. Typical of this embodiment, a front view of one aspect of the structural external part ( 1 ) of the color retinal prosthesis is shown in FIG. 1 c and a side view is shown in FIG. 1 d , ( 1 ). In addition, there are two other units which may be plugged into the external unit; when this is done they act as part of the external unit. The physician's control unit is not normally plugged into the external part worn by the patient, except when the physician is conducting an examination and adjustment of the retinal color prosthetic. The patient's controller may or may not be normally plugged in. When the patient's controller is plugged in, it can also receive signals from a remote physician's controller which then acts in the same way as the plug-in physician's controller.
Examining further the embodiment of the subsystems of the external part, see FIG. 1 b . These include an external color imager ( 111 ), an eye-motion compensation system ( 112 ), a head-motion compensation system ( 131 ), a processing unit ( 113 ), a patient's controller ( 114 ), a physician's local controller ( 115 ), a physicians hand-held palm-size pocket-size unit ( 130 ), a physician's remote controller ( 117 ), and a telemetry means ( 118 ). The color imager is a color video camera such as a CCD or CMOS video camera. It gathers an image approximating what the eyes would be seeing if they were functional.
An external imager ( 111 ) sends an image in the form of electrical signals to the video data processing unit ( 113 ). The video data processing unit consists of microprocessor CPU's and associated processing chips including high-speed data signal processing (DSP) chips. This unit can format a grid-like or pixel-like pattern that is sent to the electrodes by way of the telemetry communication subsystems ( 118 , 121 ). See FIG. 1 b . In this embodiment of the retinal color prosthesis ( FIG. 1 b , ( 121 )), these electrodes are incorporated in the internal-to-the eye implanted part.
These electrodes, which are part of the internal implant ( 121 ), together with the telemetry circuitry ( 121 ) are inside the eye. With other internally implanted electronic circuitry ( 121 ), they cooperate with the electrodes so as to replicate the incoming pattern, in a useable form, for stimulation of the retina so as to reproduce a facsimile perception of the external scene. The eye-motion ( 112 ) and head-motion ( 131 ) detectors supply information to the video data processing unit ( 113 ) to shift the image presented to the retina ( 120 ).
There are three preferred embodiments for stimulating the retina via the electrodes to convey the perception of color. Color information is acquired by the imaging means( 111 ). The color data is processed in the video data processing unit ( 113 ).
First Preferred Color Mode
Color information (See FIG. 2 a ), in the first preferred embodiment, is encoded by time sequences of pulses ( 201 ) separated by varying amounts of time ( 202 ), and also with the pulse duration being varied in time ( 203 ). The basis for the color encoding is the individual color code reference ( 211 through 217 ). The electrodes stimulate the target cells so as to create a color image for the patient, corresponding to the original image as seen by the video camera, or other imaging means. Using temporal coding of electrical stimuli placed (cf. FIG. 2 b , 220 , FIG. 2 c , 230 ) on or near the retina ( FIG. 2 b and FIG. 2 c , 221 , 222 ) the perception of color can be created in patients blinded by outer retinal degeneration. By sending different temporal coding schemes to different electrodes, an image composed of more than one color can be produced. FIG. 2 shows one stimulation protocol. Cathodic stimuli ( 202 ) are below the zero plane ( 220 ) and anodic stimuli ( 203 ) are above. All the stimulus rates are either “fast” ( 203 ) or “slow” ( 202 ) except for green ( 214 ), which includes an intermediate stimulus rate ( 204 ). The temporal codes for the other colors are shown as Red ( 211 ), as Magenta ( 212 ), as Cyan ( 213 ), as Yellow ( 215 ), as Blue ( 216 ), as Neutral ( 217 ). This preferred embodiment is directed toward electrodes which are less densely packed in proximity to the retinal cells.
Second Preferred Color Mode
Color information, in a second preferred embodiment, is sent from the video data processing unit to the electrode array, where each electrode has been determined by test to stimulate one of a bipolar type: red-center green-surround, green-center-red-surround, blue-center-yellow-surround, or yellow-center-blue-surround. In this embodiment, electrodes which are small enough to interact with a single cell, or at most, a few cells are placed in the vicinity of individual bipolar cells, which react to a stimulus with nerve pulse rates and nerve pulse structure (i.e., pulse duration and pulse amplitude). Some of the bipolar cells, when electrically, or otherwise, stimulated, will send red-green signals to the brain. Others will send yellow-blue signals. This refers to the operation of the normal retina. In the normal retina, red or green color photoreceptors (cone cells) send nerve pulses to the red-green bipolar cell which then pass some form of this information up to the ganglion cells and then up to the visual cortex of the brain. With small electrodes individual bipolar cells can be excited in a spatial, or planar, pattern. Small electrodes are those with tip from 0.1 μm to 15 μm, and which individual electrodes are spaced apart from a range 8 μm to 24 μm, so as to approximate a one-to-one correspondence with the bipolar cells. The second preferred embodiment is oriented toward a more densely packed set of electrodes.
Third Preferred Color Mode
A third preferred mode is a combination of the first and of the second preferred modes such that a broader area coverage of the color information encoded by time sequences of pulses, of varying widths and separations and with relatively fewer electrodes is combined with a higher density of electrodes, addressing more the individual bipolar cells.
First Order and Higher Effects
Regardless of a particular theory of color vision, the impinging of colored light on the normal cones, and possibly rods, give rise in some fashion to the perception of color, i.e., multi-spectral vision. In the time-pulse coding color method, above, the absence of all, or sufficient, numbers of working cones (and rods) suggests a generalization of the particular time-pulse color encoding method. The generalization is based on the known, or partly known, neuron conduction pathways in the retina. The cone cells, for example, signal to bipolar cells, which in turn signal the ganglion cells. The original spatial-temporal-color (including black, white) scheme for conveying color information as the cone is struck by particular wavelength photons is then transformed to a patterned signal firing of the next cellular level, say the bipolar cells, unless the cones are absent or don't function. Thus, this second level of patterned signal firing is what one wishes to supply to induce the perception of color vision.
The secondary layer of patterned firing may be close to the necessary primary pattern, in which case the secondary pattern (S) may be represented as P*(1+ε). The * indicates matrix multiplication. P is the primary pattern, represented as a matrix
P = [ p 11 p 1 j p k1 p kj ]
where P represents the light signals of a particular spatial-temporal pattern, e.g., flicker signals for green. The output from the first cell layer, say the cones, is then S, the secondary pattern. This represents the output from the bipolar layer in response to the input from the first (cone) layer. If S=P*(1+ε), where 1 represents a vector and ε represents a small deviation applied to the vector 1 , then S is represented by P to the lowest order, and by P*(1+ε) to the next order. Thus, the response may be seen as a zero order effect and a first order linear effect. Additional terms in the functional relationship are included to completely define the functional relationship. If S is some non-linear function of P, finding S by starting with P requires more terms then the linear case to define the bulk of the functional relationship. However, regardless of the details of one color vision theory or another, on physiological grounds S is some function of P. As in the case of fitting individual patients with lenses for their glasses, variations of parameters are expected in fitting each patient to a particular temporal coding of electrical stimuli.
Scaling Data From Photoreceptors to Bipolar Cells
As cited above, Greenberg (1998), indicates that electrical and photic stimulation of the normal retina operate via similar mechanisms. Thus, even though electrical stimulation of a retina damaged by outer retinal degeneration is different from the electrical stimulation of a normal retina, the temporal relationships are expected to be analogous.
To explain this, it is noted that electrical stimulation of the normal retinal is accomplished by stimulating the photoreceptor cells (including the color cells activated differentially according to the color of light impinging on them). For the outer retinal degeneration, it is precisely these photoreceptor cells which are missing. Therefore, the electrical stimulation in this case proceeds by way of the cells next up the ladder toward the optic nerve, namely, the bipolar cells.
The time constant for stimulating photoreceptor is about 20 milliseconds. Thus the electrical pulse duration would need to be at least 20 milliseconds. The time constant for stimulating bipolar cells is around 9 seconds. These time constants are much longer than for the ganglion cells (about 1 millisecond). The ganglion cells are another layer of retinal cells closer to the optic nerve. The actual details of the behavior of the different cell types of the retina are quite complicated including the different relationships for current threshold versus stimulus duration (cf. Greenberg, 1998). One may, however, summarize an apparent resonant response of the cells based on their time constants corresponding to the actual pulse stimulus duration.
In FIG. 2 , which is extrapolated from external-to-the-eye electrical stimulation data of Young (1977) and from light stimulation data of Festinger, Allyn, and White(1971), there is shown data that would be applicable to the photoreceptor cells. One may scale the data down based on the ratio of the photoreceptor time constant (about 20 milliseconds) to that of the bipolar cells (about 9 milliseconds). Consequently, 50 milliseconds on the time scale in FIG. 2 now corresponds to 25 milliseconds. Advantageously, stimulation rates and duration of pulses, as well as pulse widths may be chosen which apply to the electrode stimulation of the bipolar cells of the retina.
Eye Movement/Head Motion Compensation
In a preferred embodiment, an external imager such as a color CCD or color CMOS video camera ( 111 ) and a video data processing unit ( 113 ), with an external telemetry unit ( 118 ) present data to the internal eye-implant part. Another aspect of the preferred embodiment is a method and apparatus for tracking eye movement ( 112 ) and using that information to shift ( 113 ) the image presented to the retina. Another aspect of the preferred embodiment utilizes a head motion sensor ( 131 ) and a head motion compensation system ( 131 , 113 ). The video data processing unit incorporates the data of the motion of the eye as well as that of the head to further adjust the image electronically so as to account for eye motion and head motion. Thus electronic image compensation, stabilization and adjustment are provided by the eye and head movement compensation subsystems of the external part of the retinal color prosthesis.
Logarithmic Encoding of Light
In one aspect of an embodiment ( FIG. 1 b ), light amplitude is recorded by the external imager ( 111 ). The video data processing unit uses a logarithmic encoding scheme ( 113 ) to convert the incoming light amplitudes into the logarithmic electrical signals of these amplitudes ( 113 ). These electrical signals are then passed on by telemetry ( 118 ), ( 121 ), to the internal implant ( 121 ) which results in the retinal cells ( 120 ) being stimulated via the implanted electrodes ( 121 ), in this embodiment as part of the internal implant ( 121 ). Encoding is done outside the eye, but may be done internal to the eye, with a sufficient internal computational capability.
Energy and Signal Transmission
Coils
The retinal prosthesis system contains a color imager ( FIG. 1 b , 111 ) such as a color CCD or CMOS video camera. The imaging output data is typically processed ( 113 ) into a pixel-based format compatible with the resolution of the implanted system. This processed data ( 113 ) is then associated with corresponding electrodes and amplitude and pulse-width and frequency information is sent by telemetry ( 118 ) into the internal unit coils, ( 311 ), ( 313 ), ( 314 ) (see FIG. 3 a ). Electromagnetic energy, is transferred into and out from an electronic component ( 311 ) located internally in the eye ( 312 ), using two insulated coils, both located under the conjunctiva of the eye with one free end of one coil ( 313 ) joined to one free end of the second coil ( 314 ), the second free end of said one coil joined to the second free end of said second coil. The second coil ( 314 ) is located in proximity to a coil ( 311 ) which is a part of said internally located electronic component, or, directly to said internally located electronic component ( 311 ). The larger coil is positioned near the lens of the eye. The larger coil is fastened in place in its position near the lens of the eye, for example, by suturing. FIG. 3 b represents an embodiment of the telemetry unit temporally located near the eye, including an external temporal coil ( 321 ),an internal (to the eye) coil ( 314 ), an external-to-the-eye electronic chip ( 320 ), dual coil transfer units ( 314 , 323 ), ( 321 , 322 ) and an internal-to-the-eye electrode array ( 325 ). The advantage of locating the external electronics in the fatty tissue behind the eye is that there is a reasonable amount of space there for the electronics and in that position it appears not to interfere with the motion of the eye.
Ultrasonic Sound
In another aspect the information coding is done with ultrasonic sound and in a third aspect information is encoded by modulating light. An ( FIG. 3 c ) ultrasonic transducer ( 341 ) replaces the electromagnetic wave receiving coil on the implant ( 121 )inside the eye. An ultrasonic transducer ( 342 ) replaces the coil outside the eye for the ultrasonic case. A transponder ( 343 ) under the conjunctiva of the eye may be used to amplify the acoustic signal and energy either direction. By piezoelectric effects, the sound vibration is turned into electrical current, and energy extracted therefrom.
Modulated Light Beam
For the light modulation ( FIG. 3 d ) case, a light emitting diode (LED) or laser diode or other light generator ( 361 ), capable of being modulated, acts as the information transmitter. Information is transferred serially by modulating the light beam, and energy is extracted from the light signal after it is converted to electricity. A photo-detector( 362 ), such as a photodiode, which turns the modulated light signal into a modulated electrical signal, is used as a receiver. A set of a photo-generator and a photo-detector are on the implant ( 121 ) and a set is also external to the eye
Prototype-Like Device
FIG. 4 shows an example of the internal-to-the-eye and the external-to-the eye parts of the retinal color prosthesis, together with a means for communicating between the two. The video camera ( 401 ) connects to an amplifier ( 402 ) and to a microprocessor( 403 ) with memory ( 404 ). The microprocessor is connected to a modulator ( 405 ). The modulator is connected to a coil drive circuit ( 406 ). The coil drive circuit is connected to an oscillator ( 407 ) and to the coil ( 408 ). The coil ( 408 ) can receive energy inductively, which can be used to recharge a battery ( 410 ), which then supplies power. The battery may also be recharged from a charger ( 409 ) on a power line source ( 411 ).
The internal-to-the eye implanted part shows a coil ( 551 ), which connects to both a rectifier circuit ( 552 ) and to a demodulator circuit ( 553 ). The demodulator connects to a switch control unit ( 554 ). The rectifier ( 552 ) connects to a plurality of diodes ( 555 )which rectify the current to direct current for the electrodes ( 556 ); the switch control sets the electrodes as on or off as they set the switches ( 557 ). The coils ( 408 ) and ( 551 ) serve to connect inductively the internal-to-the-eye ( 500 ) subsystem and the external-to-the patient ( 400 ) subsystem by electromagnetic waves. Both power and information can be sent into the internal unit. Information can be sent out to the external unit. Power is extracted from the incoming electromagnetic signal and may be accumulated by capacitors connected to each electrode or by capacitive electrodes themselves.
Simple Electrode Implant
FIG. 6 a illustrates a set of round monopolar electrodes ( 602 ) on a substrate material ( 601 ). FIG. 7 shows the corresponding indifferent electrode ( 702 ) for these monopolar electrodes, on a substrate ( 701 ), which may be the back of ( 601 ). FIG. 6 b shows a bipolar arrangement of electrodes, both looking down onto the plane of the electrodes, positive ( 610 ) and negative ( 611 ), and also looking at the electrodes sideways to that view, positive ( 610 ) and negative ( 611 ), sitting on their substrate ( 614 ). Similarly for FIG. 6 c where a multipole triplet is shown, with two positive electrodes ( 621 ) and one negative electrode, looking down on their substrate plane, and looking sideways to that view, also showing the substrate ( 614 ).
Epiretinal Electrode Array
FIG. 8 a depicts the location of an epiretinal electrode array ( 811 ) located inside the eye ( 812 ) in the vitreous humor ( 813 ) located above the retina ( 814 ), toward the lens capsule ( 815 ) and the aqueous humor ( 816 );
One aspect of the present embodiment, shown in FIG. 8 b , is the internal retinal color prosthetic part, which has electrodes ( 817 ) which may be flat conductors that are recessed in an electrical insulator ( 818 ). One flat conductor material is a biocompatible metallic foil ( 817 ). Platinum foil is a particular type of biocompatible metal foil. The electrical insulator ( 818 ) in one aspect of the embodiment is silicone.
The silicone ( 818 ) is shaped to the internal curvature of the retina ( 814 ). The vitreous humor ( 813 ), the conductive solution naturally present in the eye, becomes the effective electrode since the insulator ( 818 ) confines the field lines in a column until the current reaches the retina ( 814 ). A further advantage of this design is that the retinal tissue ( 814 ) is only in contact with the insulator ( 818 ), such as silicone, which may be more inactive, and thus, more biocompatible than the metal in the electrodes. Advantageously, another aspect of an embodiment of this invention is that adverse products produced by the electrodes ( 817 ) are distant from the retinal tissue ( 814 ) when the electrodes are recessed.
FIG. 8 c shows elongated epiretinal electrodes ( 820 ). The electrically conducting electrodes ( 820 ) says are contained within the electrical insulation material ( 818 ); a silicon chip ( 819 ) acts as a substrate. The electrode insulator device ( 818 ) is shaped so as to contact the retina ( 814 ) in a conformal manner.
Subretinal Electrode Array
FIG. 9 a shows the location of a subretinal electrode array ( 811 ) below the retina ( 814 ), away from the lens capsule ( 815 ) and the aqueous humor ( 816 ). The retina ( 814 )separates the subretinal electrode array from the vitreous humor ( 813 ). FIG. 9 b illustrates the subretinal electrode array ( 811 ) with pointed elongated electrodes ( 817 ), the insulator ( 818 ), and the silicon chip ( 819 ) substrate. The subretinal electrode array ( 811 ) is in conformal contact with the retina ( 814 ) with the electrodes ( 817 ) elongated to some depth.
Electrodes
Iridium Electrodes
Now FIG. 10 will illuminate structure and manufacture of iridium electrodes( FIGS. 10 a - e ). FIG. 10 a shows an iridium electrode, which comprises an iridium slug( 1011 ), an insulator ( 1012 ), and a device substrate ( 1013 ). This embodiment shows the iridium slug electrode flush with the extent of the insulator. FIG. 10 b indicates an embodiment similar to that shown in FIG. 10 a , however, the iridium slug ( 1011 ) is recessed from the insulator ( 1012 ) along its sides, but with its top flush with the insulator. When the iridium electrodes ( 1011 ) are recessed in the insulating material ( 1012 ), they may have the sides exposed so as to increase the effective surface area without increasing geometric area of the face of the electrode. If an electrode ( 1011 ) is not recessed it maybe coated with an insulator ( 1012 ), on all sides, except the flat surface of the face ( 1011 )of the electrode. Such an arrangement can be embedded in an insulator that has an overall profile curvature that follows the curvature of the retina. The overall profile curvature may not be continuous, but may contain recesses, which expose the electrodes.
FIG. 10 c shows an embodiment with the iridium slug as in FIG. 10 b , however, the top of the iridium slug ( 1011 ) is recessed below the level of the insulator; FIG. 10 d indicates an embodiment with the iridium slug ( 1011 ) coming to a point and insulation along its sides ( 1021 ), as well as a being within the overall insulation structure ( 1021 ). FIG. 10 e indicates an embodiment of a method for fabricating the iridium electrodes. On a substrate ( 1013 ) of silicon, an aluminum pad ( 1022 ) is deposited. On the pad the conductive adhesive ( 1023 ) is laid and platinum or iridium foil ( 1024 ) is attached thereby. A titanium ring ( 1025 ) is placed, sputtered, plated, ion implanted, ion beam assisted deposited (IBAD) or otherwise attached to the platinum or iridium foil ( 1024 ).Silicon carbide, diamond-like coating, silicon nitride and silicon oxide in combination, titanium oxide, tantalum oxide, aluminum nitride, aluminum oxide or zirconium oxide( 1012 ) or other insulator can adhere better to the titanium ( 1025 ) while it would not otherwise adhere as well to the platinum or iridium foil ( 1024 ). The depth of the well for the iridium electrodes ranges from 0.1 μm to 1 mm.
Elongated Electrodes
Another aspect of an embodiment of the invention is the elongated electrode, which are designed to stimulate deeper retinal cells, in one embodiment, by penetrating the retina. By getting closer to the target cells for stimulation, the current required for stimulation is lower and the focus of the stimulation is more localized. The lengths chosen are 100 microns through 500 microns, including 300 microns. FIG. 8 c is a rendering of an elongated epiretinal electrode array with the electrodes shown as pointed electrical conductors ( 820 ), embedded in an electrical insulator ( 818 ), where the elongated electrodes ( 817 ) contact the retina in a conformal manner, however, penetrating into the retina ( 814 ).
These elongated electrodes, in an aspect of this of an embodiment of the invention may be of all the same length. In a different aspect of an embodiment, they may be of different lengths. Said electrodes may be of varying lengths ( FIG. 8 , 817 ), such that the overall shape of said electrode group conforms to the curvature of the retina ( 814 ). In either of these cases, each may penetrate the retina from an epiretinal position ( FIG. 8 a , 811 ), or, in a different aspect of an embodiment of this invention, each may penetrate the retina from a subretinal position ( FIG. 9 b , 817 ).
One method of making the elongated electrodes is by electroplating with one of an electrode material, such that the electrode, after being started, continuously grows in analogy to a stalagmite or stalactite. The elongated electrodes are 100 to 500 microns in length, the thickness of the retina averaging 200 microns. The electrode material is a substance selected from the group consisting of pyrolytic carbon, titanium nitride, platinum, iridium oxide, and iridium. The insulating material for the electrodes is a substance selected from the group silicon carbide, diamond-like coating, silicon nitride and silicon oxide in combination, titanium oxide, tantalum oxide, aluminum nitride, aluminum oxide or zirconium oxide.
Platinum Electrodes
FIGS. 11( a - e ) demonstrates a preferred structure of, and method of, making, spiked and mushroom platinum electrodes. Examining FIG. 11 a one sees that the support for the flat electrode ( 1103 ) and other components such as electronic circuits (not shown) is the silicon substrate ( 1101 ). An aluminum pad ( 1102 ) is placed where an electrode or other component is to be placed. In order to hermetically seal-off the aluminum and silicon from any contact with biological activity, a metal foil ( 1103 ), such as platinum or iridium, is applied to the aluminum pad ( 1102 ) using conductive adhesive( 1104 ). Electroplating is not used since a layer formed by electroplating, in the range of the required thinness, has small-scale defects or holes which destroy the hermetic character of the layer. A titanium ring ( 1105 ) is next placed on the platinum or iridium foil ( 1103 ). Normally, this placement is by ion implantation, sputtering or ion beam assisted deposition (IBAD) methods. Silicon carbide, diamond-like coating, silicon nitride and silicon oxide in combination, titanium oxide, tantalum oxide, aluminum nitride, aluminum oxide or zirconium oxide ( 1106 ) is placed on the silicon substrate( 1101 ) and the titanium ring ( 1105 ). In one embodiment, an aluminum layer ( 1107 ) is plated onto exposed parts of the titanium ring ( 1105 ) and onto the silicon carbide, diamond-like coating, silicon nitride and silicon oxide in combination, titanium oxide, tantalum oxide, aluminum nitride, aluminum oxide or zirconium oxide ( 1106 ). In this embodiment the aluminum ( 1107 ) layer acts as an electrical conductor. A mask ( 1108 ) is placed over the aluminum layer ( 1107 ).
In forming an elongated, non-flat, electrode ( FIG. 11 b ), platinum is electroplated onto the platinum or iridium foil ( 1103 ). Subsequently, the mask ( 1108 ) is removed and insulation ( 1110 ) is applied over the platinum electrode ( 1109 ).
In FIG. 11 c , a platinum electrode ( 1109 ) is shown which is more internal to the well formed by the silicon carbide, diamond-like coating, silicon nitride and silicon oxide in combination, titanium oxide, tantalum oxide, aluminum nitride, aluminum oxide or zirconium oxide and its titanium ring. The electrode ( 1109 ) is also thinner and more elongated and more pointed. FIG. 11 d shows a platinum electrode formed by the same method as was used in FIGS. 11 a , 11 b , and 11 c . The platinum electrode ( 1192 ) is more internal to the well formed by the silicon carbide, diamond-like coating, silicon nitride and silicon oxide in combination, titanium oxide, tantalum oxide, aluminum nitride, aluminum oxide or zirconium oxide and its titanium ring as was the electrode ( 1109 ) in FIG. 11 c . However it is less elongated and less pointed.
The platinum electrode is internal to the well formed by the silicon carbide, diamond-like coating, silicon nitride and silicon oxide in combination, titanium oxide, tantalum oxide, aluminum nitride, aluminum oxide or zirconium oxide and its titanium ring; said electrode whole angle at it's peak being in the range from 1° to 120°; the base of said conical or pyramidal electrode ranging from 1 micron to 500 micron; the linear section of the well unoccupied by said conical or pyramidal electrode ranging from zero to one-third.
A similar overall construction is depicted in FIG. 11 e . The electrode ( 1193 ),which may be platinum, is termed a mushroom shape. The maximum current density for a given metal is fixed. The mushroom shape presents a relatively larger area than a conical electrode of the same height. The mushroom shape advantageously allows a higher current, for the given limitation on the current density (e.g., milliamperes per square millimeter) for the chosen electrode material, since the mushroom shape provides a larger area.
Inductive Coupling Coils
Information transmitted electromagnetically into or out of the implanted retinal color prosthesis utilizes insulated conducting coils so as to allow for inductive energy and signal coupling. FIG. 12 b shows an insulated conducting coil and insulated conducting electrical pathways, e.g., wires, attached to substrates at what would otherwise be electrode nodes, with flat, recessed metallic, conductive electrodes ( 1201 ). In referring to wire or wires, insulated conducting electrical pathways are included, such as in a “two-dimensional” “on-chip” coil or a “two-dimensional” coil on a polyimide substrate, and the leads to and from these “two-dimensional” coil structures. A silicon carbide, diamond-like coating, silicon nitride and silicon oxide in combination, titanium oxide, tantalum oxide, aluminum nitride, aluminum oxide or zirconium oxide ( 1204 ) is shown acting as both an insulator and an hermetic seal. Another aspect of the embodiment is shown in FIG. 12 d . The electrode array unit ( 1201 ) and the electronic circuitry unit ( 1202 ) can be on one substrate, or they may be on separate substrates ( 1202 ) joined by an insulated wire or by a plurality of insulated wires ( 1203 ). Said separate substrate units can be relatively near one another. For example, they might lie against a retinal surface, either epiretinally or subretinally placed. Two substrates units connected by insulated wires may carry more electrodes than if only one substrate with electrodes was employed, or it might be arranged with one substrate carrying the electrodes, the other the electronic circuitry. Another arrangement has the electrode substrate or substrates placed in a position to stimulate the retinal cells, while the electronics are located closer to the lens of the eye to avoid heating the sensitive retinal tissue.
In all of the FIGS. 12 a , 12 b , and 12 c , a coil ( 1205 ) is shown attached by an insulated wire. The coil can be a coil of wire, or it can be a “two dimensional” trace as an“on-chip” component or as a component on polyimide. This coil can provide a stronger electromagnetic coupling to an outside-the-eye source of power and of signals. FIG. 12 c shows an externally placed aluminum (conductive) trace instead of the electrically conducting wire of FIG. 12 d . Also shown is an electrically insulating adhesive ( 1208 ) which prevents electrical contact between the substrates ( 1202 ) carrying active circuitry( 1209 ).
Hermetic Sealing
Hermetic Coating
All structures, which are subject to corrosive action as a result of being implanted in the eye, or, those structures which are not completely biocompatible and not completely safe to the internal cells and fluids of the eye require hermetic sealing. Hermetic sealing may be accomplished by coating the object to be sealed with silicon carbide, diamond-like coating, silicon nitride and silicon oxide in combination, titanium oxide, tantalum oxide, aluminum nitride, aluminum oxide or zirconium oxide. These materials also provide electrical insulation. The method and apparatus of hermetic sealing by aluminum and zirconium oxide coating is described in a pending U.S. patent application, Ser. No. 08/994,515, now U.S. Pat. No. 6,043,437. The methods of coating a substrate material with the hermetic sealant include sputtering, ion implantation, and ion-beam assisted deposition (IBAD).
Hermetic Box
Another aspect of an embodiment of the invention is hermetically sealing the silicon chip ( 1301 ) by placing it in a metal or ceramic box ( 1302 ) of rectangular cross-section with the top and bottom sides initially open ( FIG. 13 ). The box may be of one( 1302 ) of the metals selected from the group comprising platinum, iridium, palladium, gold, and stainless steel. Solder balls ( 1303 ) are placed on the “flip-chip”, i.e., a silicon-based chip that has the contacts on the bottom of the chip ( 1301 ). Metal feedthroughs ( 1304 ) made from a metal selected from the group consisting of radium, platinum, titanium, iridium, palladium, gold, and stainless steel. The bottom cover ( 1306 ) is formed from one of the ceramics selected from the group consisting of aluminum oxide or zirconium oxide. The inner surface ( 1305 ), toward the solder ball, ( 1303 )) of the feed-through( 1304 ) is plated with gold or with nickel. The ceramic cover ( 1306 ) is then attached to the box using a braze ( 1307 ) selected from the group consisting of: 50%titanium together with 50% nickel and gold. Electronics are then inserted and the metal top cover (of the same metal selected for the box) is laser welded in place.
Separate Electronics Chip Substrate and Electrode Substrate
In one embodiment of the invention ( FIG. 14 ), the chip substrate ( 1401 ) is hermetically sealed in a case ( 1402 ) or by a coating of the aluminum, zirconium, or magnesium oxide coating. However, the electrodes ( 1403 ) and its substrate ( 1404 ) form a distinct and separate element. Insulated and hermetically sealed wires ( 1405 ) connect the two. The placement of the electrode element may be epiretinal, while the electronic chip element may be relatively distant from the electrode element, as much distant as being in the vicinity of the eye lens. Another embodiment of the invention has the electrode element placed subretinally and the electronic chip element placed toward the rear of the eye, being outside the eye, or, being embedded in the sclera of the eye or in or under the choroid, blood support region for the retina. Another embodiment of the invention has the electronic chip element implanted in the fatty tissue behind the eye and the electrode element placed subretinally or epiretinally.
Capacitive Electrodes
A plurality of capacitive electrodes can be used to stimulate the retina, in place of non-capacitive electrodes. A method of fabricating said capacitive electrode uses a pair of substances selected from the pair group consisting of the pairs iridium and iridium oxide; and, titanium and titanium nitride. The metal electrode acts with the insulating oxide or nitride, which typically forms of its own accord on the surface of the electrode. Together, the conductor and the insulator form an electrode with capacitance.
Mini-capacitors ( FIG. 15 ) can also be used to supply the required isolating capacity. The capacity of the small volume size capacitors ( 1501 ) is 0.47 microfarads. The dimensions of these capacitors are individually 20 mils (length) by 20 mils (width)by 40 mils (height). In one embodiment of the invention, the capacitors are mounted on the surface of a chip substrate ( 1502 ), that surface being opposite to the surface containing the active electronics elements of the chip substrate.
Electrode/Electronics Component Placement
In one embodiment ( FIG. 16 a ), the internal-to-the-eye implanted part consists of two subsystems, the electrode component subretinally positioned and the electronic component epiretinally positioned. The electronics component, with its relatively high heat dissipation, is positioned at a distance, within the eye, from the electrode component placed near the retina that is sensitive to heat.
An alternative embodiment shown in FIG. 16 b is where one of the combined electronic and electrode substrate units is positioned subretinally and the other is located epiretinally and both are held together across the retina so as to efficiently stimulate bipolar and associated cells in the retina.
An alternative embodiment of the invention has the electronic chip element implanted in the fatty tissue behind the eye and the electrode element placed subretinally or epiretinally, and power and signal communication between them by electromagnetic means including radio-frequency (RF), optical, and quasi-static magnetic fields, or by acoustic means including ultrasonic transducers.
FIG. 16 c shows how the two electronic-electrode substrate units are held positioned in a prescribed relationship to each other by small magnets. Alternatively the two electronic-electrode substrate units are held in position by alignment pins. Another aspect of this is to have the two electronic-electrode substrate units held positioned in a prescribed relationship to each other by snap-together mating parts, some exemplary ones being shown in FIG. 16 d.
Neurotrophic Factor
Another aspect of the embodiment is the use of a neurotrophic factor, for example, Nerve Growth Factor, applied to the electrodes, or to the vicinity of the electrodes, to aid in attracting target nerves and other nerves to grow toward the electrodes.
Eye-Motion Compensation System
Another aspect of the embodiment is an eye-motion compensation system comprising an eye-movement tracking apparatus ( FIG. 1 b , 112 ); measurements of eye movement; a transmitter to convey said measurements to video data processor unit that interprets eye movement measurements as angular positions, angular velocities, and angular accelerations; and the processing of eye position, velocity, acceleration data by the video data processing unit for image compensation, stabilization and adjustment.
Ways of eye-tracking ( FIG. 1 b , 112 ) include utilizing the corneal eye reflex, utilizing an apparatus for measurements of electrical activity where one or more coils are located on the eye and one or more coils are outside the eye, utilizing an apparatus where three orthogonal coils placed on the eye and three orthogonal coils placed outside the eye, utilizing an apparatus for tracking movements where electrical recordings from extra-ocular muscles are measured and conveyed to the video data processing unit that interprets such electrical measurements as angular positions, angular velocities, and angular accelerations. The video data processing unit uses these values for eye position, velocity, acceleration to compute image compensation, stabilization and adjustment data which is then applied by the video data processor to the electronic form of the image.
Head Sensor
Another aspect of the embodiment utilizes a head motion sensor ( 131 ). The basic sensor in the head motion sensor unit is an integrating accelerometer. A laser gyroscope can also be used. A third sensor is the combination of an integrating accelerometer and a laser gyroscope. The video data processing unit can incorporate the data of the motion of the eye as well as that of the head to further adjust the image electronically so as to account for eye motion and head motion.
Physician's Local Control Unit
Another aspect includes a retinal prosthesis with (see FIG. 1 b ) a physician's local external control unit ( 115 ) allowing the physician to exert setup control of parameters such as amplitudes, pulse widths, frequencies, and patterns of electrical stimulation. The physician's control unit ( 115 ) is also capable of monitoring information from the implanted unit ( 121 ) such as electrode current, electrode impedance, compliance voltage, and electrical recordings from the retina. The monitoring is done via the internal telemetry unit, electrode and electronics assembly ( 121 ).
An important aspect of setting up the retinal color prosthesis is setting up electrode current amplitudes, pulse widths, and frequencies so they are comfortable for the patient. FIGS. 17 a - c and FIGS. 18 a - c illustrate some of the typical displays. A computer-controlled stimulating test that incorporates patient response to arrive at optimal patient settings may be compared to being fitted for eyeglasses, first determining diopter, then cylindrical astigmatic correction, and so forth for each patient. The computer uses interpolation and extrapolation routines. Curve or surface or volume fitting of data maybe used. For each pixel, the intensity in increased until a threshold is reached and the patient can detect something in his visual field. The intensity is further increased until the maximum comfortable brightness is reached. The patient determines his subjective impression of one-quarter maximum brightness, one-half maximum brightness, and three-quarters maximum brightness. Using the semi-automated processing of the patient-in-the-loop with the computer, the test program runs through the sequences and permutations of parameters and remembers the patient responses. In this way apparent brightness response curves are calibrated for each electrode for amplitude. Additionally, in the same way as for amplitude, pulse width and pulse rate (frequency), response curves are calibrated for each patient. The clinician can then determine what the best settings are for the patient.
This method is generally applicable to many, if not all, types of electrode based retinal prostheses. Moreover, it also is applicable to the type of retinal prosthesis, which uses an external light intensifier shining upon essentially a spatially distributed set of light sensitive diodes with a light activated electrode. In this latter case, a physician's test, setup and control unit is applied to the light intensifier which scans the implanted photodiode array, element by element, where the patient can give feedback and so adjust the light intensifier parameters.
Remote Physician's Unit
Another aspect of an embodiment of this invention includes (see FIG. 1 b ) a remote physician control unit ( 117 ) that can communicate with a patient's unit ( 114 ) over the public switched telephone network or other telephony means. This telephone-based pair of units is capable of performing all of the functions of the of the physician's local control unit ( 115 ).
Physician's Unit Measurements, Menus and Displays
Both the physician's local ( 115 ) and the physician's remote ( 117 ) units always measure brightness, amplitudes, pulse widths, frequencies, patterns of stimulation, shape of log amplification curve, electrode current, electrode impedance, compliance voltage and electrical recordings from the retina.
FIG. 17 a shows the main screen of the Physician's Local and Remote Controller and Programmer. FIG. 17 b illustrates the pixel selection of the processing algorithm with the averaging of eight surrounding pixels chosen as one element of the processing. FIG. 17 c represents an electrode scanning sequence, in this case the predefined sequence, A. FIG. 17 d shows electrode parameters, here for electrode B, including current amplitudes and waveform timelines. FIG. 17 e illustrates the screen for choosing the global electrode configuration, monopolar, bipolar, or multipolar. FIG. 17 f renders a screen showing the definition of bipolar pairs (of electrodes). FIG. 17 g shows the definition of the multipole arrangements.
FIG. 18 a illustrates the main menu screen for the palm-sized test unit. FIG. 18 b shows a result of pressing on the stimulate bar of the (palm-sized unit) main menu screen, where upon pressing the start button the amplitudes A 1 and A 2 are stimulated for times t 1 , t 2 , t 3 , and t 4 , until the stop button is pressed. FIG. 18 c exhibits a recording screen that shows the retinal recording of the post-stimulus and the electrode impedance.
FIGS. 19 a , 19 b , and 19 c show different embodiments of the Physician's Remote Controller, which has the same functionality inside as the Physician's Local Controller but with the addition of communication means such as telemetry or telephone modem.
Patient's Controller
Corresponding to the Physician's Local Controller, but with much less capability, is the Patient's Controller. FIG. 20 shows the patient's local controller unit. This unit can monitor and adjust brightness ( 2001 ), contrast ( 2002 ) and magnification ( 2003 ) of the image on a non-continuous basis. The magnification control ( 2003 ) adjusts magnification both by optical zoom lens control of the lens for the imaging means( FIG. 1 , 111 ), and by electronic adjustment of the image in the data processor ( FIG. 2 , 113 ).
While the invention herein disclosed has been described by means of specific embodiments and applications thereof, numerous modifications and variations could be made thereto by those skilled in the art without departing from the scope of the invention set forth in the claims.
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An implantable electronic device is formed within a biocompatible hermetic package. Preferably the implantable electronic device is used for a visual prosthesis for the restoration of sight in patients with lost or degraded visual function. The package may include a hard hermetic box, a thin film hermetic coating, or both.
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CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a continuation-in-part of U.S. patent application Ser. No. 12/757,443. entitled “Intervertebral Implant” (filed Apr. 9, 2010), the contents of which are incorporated herein by reference in their entirety.
BACKGROUND
[0002] Historically, complete removal of a disc from between adjacent vertebrae resulted in the need to immovably fuse the adjacent vertebrae together, and this “spinal fusion” procedures is still used today as a widely-accepted surgical treatment for disc removal stemming from, for example, a degenerative disc disease or disc injury. However, in many instances, disc arthoplasty—the insertion of an artificial intervertebral disc into the intervertebral space between adjacent vertebrae—may be preferable to spinal fusion as the former may help preserve some limited universal movement of the adjacent vertebrae with respect to each other whereas the latter does not. As such, the objective of total disc replacement is not only to diminish pain caused by a degenerated disc, but also to restore anatomy (disc height) and maintain mobility in the functional spinal unit so that the spine remains in an adapted “sagittal balance” (the alignment equilibrium of the trunk, legs, and pelvis necessary to maintain the damping effect of the spine).
[0003] Several forms of intervertebral implants include an upper part mounted to an adjacent vertebra, a lower part mounted to another adjacent vertebra, and a rotation-assist insert located between these two parts. In addition these intervertebral implants are often very small—perhaps ten millimeters wide and a few millimeters high—and are thus difficult for surgeons to hold, orient, and emplace when using just their fingers. Nevertheless, implantation of these intervertebral devices (or “implant devices”) requires precise and careful emplacement in order to ensure correction functioning.
SUMMARY
[0004] To assist with the correct emplacement of an implant device, an insertion tool comprising an implant holder may be utilized. Generally the implant holder must be able to firmly affix to the implant device in order to allow the surgeon to use the necessary pressure and force required to properly emplace the implant device, but then disengage from the implant device once the implant device is correctly positioned and enable the implant holder to be completely withdrawn.
[0005] Disclosed herein are various embodiments directed to an implant holder for an implant device comprising a clamp for coupling to and decoupling from the implant device, and a locking mechanism that, in a first position, causes the clamp to lock the implant device such that the clamp cannot be decoupled from the implant device, and in a second position, causes the clamp to unlock the implant device such that the clamp remains coupled to the implant device in the absence of a sufficient decoupling force (such as a surgeon force, defined later herein) but is decoupled from the implant device in the presence of a sufficient decoupling force.
[0006] Also disclosed herein are several methods of implanting an implant device using an implant holder comprising coupling the implant device to the implant holder, locking the implant device and the implant holder, emplacing the implant device utilizing the implant holder, unlocking the implant device and the implant holder such that the implant device is still coupled to the implant holder, and uncoupling the implant device from the implant holder and withdrawing the implant holder.
[0007] This summary is provided to introduce a selection of concepts in a simplified form that are further described below in the detailed description. This summary is not intended to identify key features or essential features of the claimed subject matter, nor is it intended to be used to limit the scope of the claimed subject matter.
BRIEF DESCRIPTION OF THE DRAWINGS
[0008] To facilitate an understanding of and for the purpose of illustrating the present disclosure, exemplary features and implementations are disclosed in the accompanying drawings, it being understood, however, that the present disclosure is not limited to the precise arrangements and instrumentalities shown, and wherein similar reference characters denote similar elements throughout the several views, and wherein:
[0009] FIG. 1A is a perspective view of a pair of vertebral bodies separated by an intervertebral space;
[0010] FIG. 1B is a side elevation view illustrating the insertion of an intervertebral implant into the intervertebral space between the two vertebral bodies of FIG. 1A ;
[0011] FIG. 1C is a perspective view of the vertebral bodies of FIGS. 1A and 1B with an intervertebral implant inserted into the intervertebral space;
[0012] FIG. 2A is a perspective view of the intervertebral implant illustrated in FIG. 1B which includes first and second endplates and an articulation disposed between the endplates;
[0013] FIG. 2B is a side elevation view of the intervertebral implant illustrated in FIG. 2A ;
[0014] FIG. 3A is a perspective view of an exemplary implementation of an implant holder clamp utilized by several implant holder embodiments disclosed herein;
[0015] FIG. 3B is a top elevation view of the exemplary implementation of the clamp of FIG. 3A ;
[0016] FIG. 3C is a side elevation view of the exemplary implementation of the clamp of FIGS. 3A and 3B ;
[0017] FIG. 4A is a perspective view of the implant holder clamp of FIGS. 3A , 3 B, and 3 C being coupled to an intervertebral implant of FIGS. 2A and 2B (the latter still housed in sterile packaging);
[0018] FIG. 4B is a top view of the implant holder coupled to the intervertebral implant (and together removed from the sterile packaging of FIG. 4A );
[0019] FIG. 4C is a side elevation view of the implant holder coupled to the intervertebral implant illustrated in FIG. 4B ;
[0020] FIG. 5 a top view of an exemplary implementation of an implant holder sleeve (or guide member) utilized by several implant holder embodiments disclosed herein;
[0021] FIG. 6 a top view of an exemplary implementation of an implant holder shaft (or rotation member) utilized by several implant holder embodiments disclosed herein;
[0022] FIG. 7 is a top view of the shaft of FIG. 6 translationally and rotationally coupled with the sleeve of FIG. 5 ;
[0023] FIG. 8A is top view of the sleeve and shaft combination of FIG. 7 coupled to the clamp and implant combination of FIGS. 4B and 4C in an unlocked configuration;
[0024] FIG. 8B is top view of the distal end of the sleeve and shaft combination coupled to the clamp and implant combination in the unlocked configuration illustrated in FIG. 8A ;
[0025] FIG. 9A is perspective view of the implant and the distal end of the implant holder (comprising the clamp, sleeve, and shaft) of FIGS. 8A and 8B in a locked configuration;
[0026] FIG. 9B is top view of the implant and the distal end of the implant holder (comprising the clamp, sleeve, and shaft) in the locked configuration illustrated in FIG. 9A ;
[0027] FIG. 10A is a perspective view of an exemplary implementation of an implant holder emplacement stop system utilized by certain implant holder embodiments disclosed herein;
[0028] FIG. 10B is a side elevation view of the exemplary implementation of the stop system of FIG. 10A ;
[0029] FIG. 10C is a top elevation view of the exemplary implementation of the stop system of FIGS. 10A and 10B ;
[0030] FIG. 11A is a perspective view of the exemplary implementation of an implant holder emplacement stop system of FIGS. 10A , 10 B, and 10 C connectively coupled to the top side of the implant holder sleeve of FIG. 5 ;
[0031] FIG. 11B is a perspective view of the exemplary implementation of an implant holder emplacement stop system of 11 A in an alternative configuration connectively coupled to the bottom side of the implant holder sleeve;
[0032] FIG. 11C is a perspective view of the proximal end of the stop system illustrated in FIG. 11A ; and
[0033] FIG. 12 is an operational flow diagram illustrating a method for emplacing an implant using certain embodiments of the implant holder disclosed herein.
DETAILED DESCRIPTION
[0034] Certain terminology is used in the following description for convenience only and is not limiting. The words “right”, “left”, “lower”, and “upper” designate direction in the drawings to which reference is made. The words “inner”, “outer” refer to directions toward and away from, respectively, the geometric center of the described feature or device. The words “distal” and “proximal” refer to directions taken in context of the item described and, with regard to the instruments herein described, are typically based on the perspective of the surgeon using such instruments. The words “anterior”, “posterior”, “superior”, “inferior”, “medial”, “lateral”, and related words and/or phrases designate preferred positions and orientation in the human body to which reference is made. The terminology includes the above-listed words, derivatives thereof, and words of similar import.
[0035] In addition, various components are described herein as extending horizontally along a longitudinal direction “L” and lateral direction “A”, and vertically along a transverse direction “T”. Unless otherwise specified herein, the terms “lateral”, “longitudinal”, and “transverse” are used to describe the orthogonal directional components of various items. It should be appreciated that while the longitudinal and lateral directions are illustrated as extending along a horizontal plane, and that the transverse direction is illustrated as extending along a vertical plane, the planes that encompass the various directions may differ during use. For instance, when an implant is emplaced into an intervertebral space, the transverse direction T extends generally along the superior-inferior (or caudal-cranial) direction, while the plane defined by the longitudinal direction L and the lateral direction A lie generally in the anatomical plane defined by the anterior-posterior direction and the medial-lateral direction. Accordingly, the directional terms “vertical” and “horizontal” are used to describe the components merely for the purposes of clarity and illustration and are not meant to be limiting.
[0036] FIG. 1A is a perspective view of a pair of vertebral bodies 12 a and 12 b separated by an intervertebral space 14 . FIG. 1B is a side elevation view illustrating the insertion of an intervertebral implant 10 into the intervertebral space 14 between the two vertebral bodies 12 a and 12 b of FIG. 1A . FIG. 1C is a perspective view of the vertebral bodies 12 a and 12 b of FIGS. 1A and 1B with the intervertebral implant 10 inserted into the intervertebral space 14 .
[0037] Referring to FIGS. 1A , 1 B, and 1 C (collectively referred to herein as “FIG. 1 ”), a superior vertebral body 12 a defines a superior vertebral surface 15 a of an intervertebral space 14 , and an adjacent inferior vertebral body 12 b defines an inferior vertebral surface 15 b of the intervertebral space 14 . The intervertebral space 14 may be created by a discectomy where the disc material (not shown) normally found between the two vertebral bodies 12 a and 12 b has been removed to prepare the intervertebral space 14 to receive an orthopedic implant such as, for example, the intervertebral implant 10 .
[0038] During operation the implant 10 is aligned with the intervertebral space 14 . The vertebral bodies 12 a and 12 b are retracted such that the anterior ends 96 of the vertebral bodies are separated generally along the caudal-cranial dimension a distance greater than the posterior ends 98 of the vertebral bodies 12 a and 12 b are separated. The implant 10 may then be inserted into the intervertebral space 14 to achieve restoration of “height” (that is, anatomically correct separation of the superior vertebral surface 15 a from inferior vertebral surface 15 b ) while maintaining mobility.
[0039] FIG. 2A is a perspective view of the intervertebral implant 10 illustrated in FIG. 1B which includes first and second endplates ( 20 and 22 respectively) together forming an articulation disposed between the endplates. FIG. 2B is a side elevation view of the intervertebral implant illustrated in FIG. 2A .
[0040] Referring now to FIGS. 2A and 2B (collectively referred to herein as “FIG. 2 ”), and with reference to FIG. 1 , the implant 10 may include a first or upper component, such as a first or upper endplate 20 adapted to engage the superior vertebral body 12 a , and a second or lower component, such as a second or lower endplate 22 adapted to engage the inferior vertebral body 12 b . The endplates 20 and 22 each carry complementary first and second joint members 75 and 77 , respectively, that provide rounded mating surfaces (concave for joint member 75 and convex for joint member 77 ) in operative contact with each other so as to provide an articulating joint that allows the endplates 20 and 22 360-degree universal movement relative to each other. The upper and lower endplates 20 and 22 can thus pivot relative to each other about a lateral axis, for instance to accommodate flexions and extensions of the vertebrae 12 a and 12 b . Similarly, the upper and lower endplates 20 and 22 can pivot relative to each other about a longitudinal axis, for instance to accommodate lateral bending of the vertebrae 12 a and 12 b . The pivot axis can also lie in any orientation within the horizontal plane defined by the longitudinal and lateral directions.
[0041] In addition to the concave mating surfaces 75 , the upper endplate 20 also comprises an upper endplate body 21 that defines a longitudinally front end 23 , which provides a leading end with respect to insertion of the implant 10 into the intervertebral disc space 14 . The upper endplate body 21 further defines an opposing longitudinal rear end 25 , which provides a trailing end with respect to insertion of the implant 10 into the intervertebral disc space 14 . The upper endplate body 21 further defines opposing first and second lateral sides 27 and 29 , respectively, connected between the front and rear ends 23 and 25 respectively. The upper endplate body 21 further presents an upper (or outer) transverse bone facing surface 24 , and an opposing lower (or inner) transverse surface 43 . The upper endplate 20 includes a plurality of bone fixation spikes 39 projecting transversely outward, or up, from the bone facing surface 24 of the upper endplate body 21 .
[0042] Similarly, in addition to the convex mating surfaces 77 , the lower endplate 22 also comprises a lower endplate body 37 that defines a longitudinally front end 47 , which provides a leading end with respect to insertion of the implant 10 into the intervertebral disc space 14 . The lower endplate body 37 further defines an opposing longitudinal rear end 31 , which provides a trailing end with respect to insertion of the implant 10 into the intervertebral disc space 14 . The lower endplate body 37 further defines opposing first and second lateral sides 33 and 35 , respectively, connected between the front and rear ends 47 and 31 respectively. The lower endplate body 37 further presents a lower (or outer) transverse bone facing surface 26 , and an opposing upper (or inner) transverse surface 45 . The lower endplate 22 includes a plurality of bone fixation spikes 41 projecting transversely outward, or down, from the bone facing surface 26 of the lower endplate body 37 .
[0043] The front ends 23 and 47 of the endplates 20 and 22 define the front end 11 of the implant 10 corresponding to the posterior of the intervertebral space 14 for emplacement, while the rear ends 25 and 31 of the endplates 20 and 22 define the back end 13 of the implant 10 corresponding to the opposing anterior of the intervertebral space 14 for emplacement. Otherwise stated, the front end 11 is emplaced into the posterior region (proximate to posterior ends 98 ) of the intervertebral space 14 and the back end 13 is emplaced into the anterior region (proximate to anterior ends 96 ) of the intervertebral space 14 .
[0044] To facilitate emplacement using an implant holder (various embodiments of which are described in detail later herein), the upper endplate 20 includes laterally opposing notches 85 that are external engagement features extending into the rear end 25 of the endplate body 21 that are sized and shaped to receive the upper portion of the distal end of an insertion tool (or implant holder) configured to insert the implant into an intervertebral space. The lower endplate 22 includes laterally opposing notches 87 extending into the rear end 31 of the endplate body 37 that are sized and shaped to receive the lower portion of an insertion tool configured to insert the implant 10 into an intervertebral space.
[0045] As the implant 10 is inserted into the intervertebral space 14 , the spikes 39 and 41 initially slide freely into the intervertebral space 14 , and prior to full insertion begin to bite into the respective vertebral surfaces 15 a and 15 b . Once the implant 10 has been fully inserted into the intervertebral space 14 , the retraction of the vertebral bodies 12 a and 12 b is released, thereby causing the surfaces 15 a and 15 b to return to their normal direction of extension, whereby the spikes 39 and 41 project into the vertebral surfaces 15 a and 15 b.
[0046] Since it may be challenging to manually handle the implant 10 because of its small size (e.g., less than ten millimeters wide, ten millimeters long, and only a few millimeters thick), a separate instrument—referred to as an implant holder or insertion tool—may be used to emplace the vertebral implant 10 . In general, the implant 10 is fixed to the implant holder, and then the surgeon directly manipulates the implant holder to emplace the implant 10 (without ever directly touching the implant in some embodiments). When the implant 10 is seemingly in place, the surgeon then uses X-rays to check position of the implant 10 (typically in profile) to see whether the implant 10 is properly placed or whether it must still be further maneuvered into a better position, and the surgeon adjusts the implants position as necessary by continuing to manipulate the implant holder. Once the desired emplacement of the implant 10 is seemingly achieved, the implant holder is then detached from the implant 10 and withdrawn, leaving behind the emplaced implant 10 .
[0047] Various implant holders are disclosed herein comprise three functional components: a clamp, a sleeve, and a shaft. While these components are disclosed as distinct, separate, and interchangeable pieces that can be operatively coupled together for utilization, it will be readily understood and appreciated that these three functional components can also be formed as a single tool wherein the components are inseparable, or as a two-part tool wherein any two of the three operational components are formed as a single item. Similarly, an optional fourth component—an emplacement stop system—is also herein disclosed as a separate fourth piece for use with the implant holder but which can also be formed as part of the implant holder (namely the sleeve). Accordingly, nothing herein is intended to limit the embodiments described herein to separable components but, instead, a single formed piece may comprise one or more than one of the operational components described herein.
[0048] FIG. 3A is a perspective view of an exemplary implementation of an implant holder clamp 100 (or clamp) utilized by several implant holder embodiments disclosed herein. FIG. 3B is a top elevation view of the exemplary implementation of the clamp 100 of FIG. 3A . FIG. 3C is a side elevation view of the exemplary implementation of the clamp 100 of FIGS. 3A and 3B .
[0049] Referring to FIGS. 3A , 3 B, and 3 C (collectively referred to herein as “FIG. 3 ”), the implant holder clamp 100 essentially comprises a U-shaped fork with two arms 102 and 104 fixedly coupled to a stem 106 . As illustrated, the stem 106 may comprise a substantially solid rod 110 with a shallow threaded hole 112 at the proximal end for attaching to the threaded end of a shaft. The stem is also fixedly coupled to each arm 102 and 104 proximate to a flexion hole 114 . The arms 102 and 104 are separated from each other by the flexion hole 114 and by a lateral gap 118 running from the flexion hole 114 to the distal end of the clamp 100 . Moreover, each arm 102 and 104 comprises a flexion portion 116 —in part formed by the flexion hole 114 —which provides the arms 102 and 104 with limited flexibility such that they can be moved toward or away from each other relative to their resting position (as illustrated) with the application of force (which also has the effect of decreasing or increasing the width of the lateral gap 118 running between the arms 102 and 104 ).
[0050] The amount of force necessary to slightly separate the two arms 102 and 104 is dependent upon the thickness of the flexion portion 116 and the material from which the flexion portions (and, ostensibly, the entire stem) is made. For various embodiments disclosed herein, the amount of force required is low enough to enable a surgeon of ordinary strength and dexterity to affix an implant 10 onto the arms 102 and 104 of the implant holder clamp 100 as well as enable the implant 10 to detach and remain in position when emplaced in the intervertebral space 14 as the implant holder clamp 100 is withdrawn using a retraction force applied by the surgeon, but yet high enough to prevent the implant 10 from becoming inadvertently detached from the implant holder clamp 100 such as while the implant 10 is being emplaced in a forward longitudinal direction using the implant holder clamp 100 . This force is hereafter referred to as a “surgeon force” and an implant 10 that is attached and detached to an implant holder clamp 100 using surgeon force is said to be “loosely coupled.” In contrast, and as described later herein, when the implant cannot be decoupled from the implant holder using surgeon force, the implant is said to be “fixedly coupled.”
[0051] Referring again to FIG. 3 , each arm 102 and 104 further comprises a central body 120 featuring two of four clamping elements 132 (one superior and one inferior), half of a U-shaped central spacer 130 , and one of a pair of locking surfaces 126 . In normal operation, the four central-projecting clamping elements 132 are able to engage the notches 85 and 87 of the implant device 10 with the application of surgeon force as previously described. However, the locking surfaces 126 of each arm 102 and 104 enable the application of a locking force (for example, by operation of the shaft and sleeve discussed later herein) to fixedly couple the implant 10 to the clamp 100 by preventing the arms 102 and 104 from flexibly opening. Separately, the U-shaped central spacer 130 formed by both arms 102 and 104 semi-circumferentially abut against the convex joint member 77 of the articulating joint of the implant 10 as well as the upper and lower endplates 20 and 22 in order to maintain in parallel the lower (or inner) transverse surface 43 of the upper endplate 20 and the upper (or inner) transverse surface 45 of the lower endplate 22 to give temporary solidity to the implant 10 during its emplacement.
[0052] In addition, each arm also comprises an optical control channel 122 on the upper surface of the arms 102 and 104 to enable the surgeon to visually gauge the location of the back end 13 of the implant 10 when the surgeon uses X-rays to check position of the implant 10 in profile (or laterally). For example, when the clamp 100 and the implant 10 are both made of radio-opaque materials (or any other situation where it is difficult to tell apart the implant 10 from the clamp 100 using X-rays), this optical control channel 122 provides an X-ray-visible feature that enables the surgeon to differentiate between the two components and better determine how far the back end 13 of the implant 10 is embedded (or “implanted” or “emplaced”) in the intervertebral space 14 . To this end, the optical control channel 122 may simply comprise a straight line-of-sight channel (with the arms in the resting position) or, alternatively, it may be coated or filled with X-ray reflective or deflective material to make it even more easily identified using an X-ray. Likewise, the channel may also be shaped differently—such as, for example, narrower medially but wider laterally to provide a less-specific by easier-to-identify reference point—and/or the clamp 100 may comprise more than one channel—such as, for example, a second optical control channel running on the lower endplate running parallel to the first optical control channel 122 .
[0053] FIG. 4A is a perspective view of the implant holder clamp 100 of FIGS. 3A , 3 B, and 3 C being coupled to an intervertebral implant 10 of FIGS. 2A and 2B (the latter still housed in sterile packaging 400 . FIG. 4B is a top view of the implant holder 100 coupled to the intervertebral implant 10 (and together removed from the sterile packaging 400 of FIG. 4A ). FIG. 4C is a side elevation view of the implant holder 10 coupled to the intervertebral implant 10 illustrated in FIG. 4B . Referring to FIGS. 4A , 4 B, and 4 C (collectively referred to herein as “FIG. 4 ”), the implant 10 is removed from its sterile packing longitudinally moving the implant holder 100 with surgeon force to loosely couple with the implant and then retracting the implant holder 100 and the implant 10 from the packaging—which, as illustrated, may be accomplished without the person performing the coupling directly touching the implant 10 . With particular reference to FIG. 4B , it should be noted that the left edge of the optical control channel 122 of the implant holder 100 is substantially aligned with the back end 13 of the implant 10 such that the back end 13 of the implant can be accurately determined by locating the optical control channel 122 during the surgeon's aforementioned X-ray checks.
[0054] FIG. 5 a top view of an exemplary implementation of an implant holder sleeve (or guide member) 200 utilized by several implant holder embodiments disclosed herein. Referring to FIG. 5 , the sleeve 200 comprises a hollow body 210 featuring, at its proximal end, an attachment surface 240 , a service collar 212 , and the proximal opening of the hollow channel 214 running the length of the sleeve 200 . The attachment surface 240 may be used for mounting supplemental devices to the sleeve 200 (such as the stop system discussed later herein, for example). At the distal end, the hollow body 210 features a clamp coupler 216 which in turn comprises two locking tines 220 and the distal opening of the hollow channel 214 in a terminus surface 218 . The two locking tines 220 each comprise a locking surface 222 that are together geometrically angled to substantially match the geometric angle of the two locking surfaces 126 of the implant holder clamp 100 .
[0055] FIG. 6 a top view of an exemplary implementation of an implant holder shaft 300 (or rotation member) utilized by several implant holder embodiments disclosed herein. Referring to FIG. 6 , the sleeve 200 comprises a rod 310 featuring, at its proximal end, an in-hole stabilizer 314 , a mating collar 312 , and a rotation knob 316 . At its distal end, the rod 210 further comprises a threaded post 318 for engaging the threaded hole 112 of the implant holder clamp 100 .
[0056] FIG. 7 is a top view of the shaft 300 of FIG. 6 translationally and rotationally coupled with the sleeve 200 of FIG. 5 , such that the distal end of the shaft (featuring the threaded post 318 ) is inserted through the proximal opening of the hollow channel 214 and runs the length of the sleeve 200 to distal end, wherein the sleeve 200 circumferentially and encloses the distal and medial portions of the shaft 300 .
[0057] FIG. 8A is top view of the sleeve 200 and shaft 300 combination of FIG. 7 (also referred to herein as the “locking mechanism”) coupled to the clamp 100 and implant 10 combination of FIGS. 4B and 4C in an unlocked configuration. FIG. 8B is top view of the distal end of the sleeve and shaft combination coupled to the clamp and implant combination in the unlocked configuration illustrated in FIG. 8A . Referring to FIGS. 8A and 8B (collectively referred to herein as “FIG. 8 ”), the stem 110 (not shown) of the implant holder 100 movably resides in the distal opening of the hollow channel 214 proximate to the terminus surface 218 of the sleeve 200 , and the threaded hole 112 of the implant holder 100 is partially coupled to the threaded post 318 of the shaft 300 . As the shaft 300 continues to be rotated (via the rotation knob 316 in a tightening direction), the threaded post 318 will continue draw the stem 110 (not shown) into the hollow channel 214 and move the implant holder 100 and its pair of locking surfaces 126 closer and closer to the clamp coupler 216 and its locking surfaces 222 . As such, rotating the shaft 300 within the sleeve 200 permits the surgeon (or a skilled assistant) to selectively determine to lock or unlock the clamp 100 which, in turn, determines whether the implant 10 is fixedly coupled (when locked) or loosely coupled (when unlocked) to the clamp 100 .
[0058] FIG. 9A is perspective view of the implant 10 and the distal end of the implant holder (comprising the clamp 100 , sleeve 200 , and shaft 300 ) of FIGS. 8A and 8B in a locked configuration. FIG. 8B is top view of the implant 10 and the distal end of the implant holder (comprising the clamp 100 , sleeve 200 , and shaft 300 ) in the locked configuration illustrated in FIG. 9A . Referring to FIGS. 9A and 9B (collectively referred to herein as “FIG. 9 ”), the stem 110 (not shown) of the implant holder 100 has been maximally retracted into the distal opening of the hollow channel 214 proximate to the terminus surface 218 of the sleeve 200 by rotation of the threaded post 318 via the rotation knob 316 . In this configuration, the implant holder's 100 pair of locking surfaces 126 are in direct contact with the clamp coupler's 216 locking surfaces 222 which, in turn, prevents the arms 102 and 104 (not shown) and their corresponding clamping elements 132 from flexibly opening and decoupling from the implant 10 —that is, the implant 10 is “locked” or fixedly coupled to the clamp 100 of the implant holder (i.e., in a “locked position”). As such, the surgeon may emplace, move, and even withdraw the implant 10 and implant holder clamp 100 using surgeon force without leaving the implant 10 behind (as would be the case in an unlocked configuration) or risking the implant 10 from becoming inadvertently decoupled from the clamp 100 .
[0059] To unlock the implant 10 from the clamp 100 —such as when the surgeon has satisfactorily emplaced the implant 10 into the intervertebral space 14 , for example—the surgeon merely rotates the shaft 200 in a loosening direction opposite the tightening direction (via the rotation knob 316 ) to separate the locking surfaces 126 of the implant holder clamp 100 from the locking surfaces 222 of the implant holder sleeve 200 and again return to a configuration akin to that shown in FIG. 8 , in which instance the implant 10 is again only loosely coupled to the clamp 100 and can be removed by surgeon force from the clamp 100 .
[0060] FIG. 10A is a perspective view of an exemplary implementation of an implant holder emplacement stop system 500 utilized by certain implant holder embodiments disclosed herein. FIG. 10B is a side elevation view of the exemplary implementation of the stop system 500 of FIG. 10A . FIG. 10C is a top elevation view of the exemplary implementation of the stop system of FIGS. 10A and 10B . Referring to FIGS. 10A , 10 B, and 10 C (collectively referred to herein as “FIG. 10 ”), the stop system comprises a clip 502 for clipping to an attachment surface 240 of an implant holder sleeve 200 and rotatably mounting a threaded rotor 504 engaging the threaded proximal end 506 ′ of a stop body 506 . The distal end of the stop body 506 is coupled to a slidable sleeve 508 that, in turn, is coupled to a stop rod 510 ending in a stop surface 512 comprising the most distal end of the stop system 500 . For certain embodiments, the stop system 512 may be used to reduce risk of penetration into spinal canal during the implantation procedure.
[0061] FIG. 11A is a perspective view of the exemplary implementation of an implant holder emplacement stop system of FIGS. 10A , 10 B, and 10 C connectively coupled to the top side of the implant holder sleeve 200 of FIG. 5 . FIG. 11B is a perspective view of the exemplary implementation of an implant holder emplacement stop system of 11 A in an alternative configuration connectively coupled to the bottom side of the implant holder sleeve. FIG. 11C is a perspective view of the proximal end of the stop system illustrated in FIG. 11A . Referring to FIGS. 11A , 11 B, and 11 C (collectively referred to herein as “FIG. 11 ”), by rotating the threaded rotor 504 the surgeon can longitudinally move the stop 512 to correspond to a desired depth such that when used, the stop will abut up against the anterior surface of a vertebrae (such as superior vertebral body 12 a ) and prevent the implant 10 from being emplaced any deeper into the intervertebral space 14 .
[0062] FIG. 12 is an operational flow diagram illustrating a method for emplacing an implant 10 using certain embodiments of the implant holder disclosed herein. Referring to FIG. 12 , at 602 the surgeon (or a qualified assistant) couples the shaft 300 to the sleeve 200 by inserting the shaft 300 into the sleeve 200 as previously discussed herein. At 604 , the surgeon also couples (that is, loosely couples in an unlocked configuration) the clamp 100 to the implant 10 . At 606 the surgeon them coupled the clamp 100 and implant 10 combination to the sleeve 200 and shaft 300 combination (or “locking mechanism”) which initially is still in the unlocked configuration (or “unlocked position”). In an alternative approach, the surgeon could first couple the clamp, sleeve, and shaft in an unlocked configuration, and then couple this three-part assembly to the implant. In other words, there are several ways in which each of the clamp 100 , sleeve 200 , shaft 300 , and implant 10 are coupled, and thus the order presented in FIG. 12 is only exemplary and is in no way limiting.
[0063] At 608 the surgeon then locks the implant 10 into the implant holder by engaging the locking surfaces 126 of the clamp 100 with the locking surfaces 222 of the sleeve 200 and, at 610 , the surgeon then proceeds to emplace the implant 10 using the assembled implant holder (with or without the optional stop system 500 ). After emplacing the implant 10 , the surgeon then uses X-rays (and the optical control channel 122 as an X-ray-visible reference point) to determine if the implant is emplaced in a suitable location. If not (as determined at 614 ), at 624 the surgeon reiteratively re-emplaces the implant 10 by continuing to manipulate the implant 10 via the implant holder and, returning to 612 , checking implant 10 until it is properly emplaced.
[0064] Once properly emplaced, at 616 the implant 10 and implant holder are unlocked and, at step 618 , the implant holder is withdrawn (or retracted) using surgeon force. At 620 , if the embedding of the implant 10 is stable, the implant should remain embedded and, if so, the surgeon can then conclude the embedding portion of the procedure. However, if the implant 10 is not stable and continues to be loosely coupled to the implant holder when withdrawn, then the surgeon needs to re-emplace the implant (or a different implant) at step 624 and continue again from there.
[0065] As will readily appreciated by those of skill in the art, the various components described herein can be formed from a variety of biocompatible materials, such as cobalt chromium molybdenum (CoCrMo), titanium and titanium alloys, stainless steel or other metals, as well as ceramics or polymers such as polyetheretherketone (PEEK), polyetherketoneketone (PEKK), bioresorbable materials, and bonegraft (for example allograft and xenograft). A coating may be added or applied to the various components described herein to improve physical or chemical properties, or to help ensure bony in or on growth of medication. Examples of coatings include plasma-sprayed titanium coating or Hydroxypatite. Moreover, skilled artisans will also appreciate that the various components herein described can be constructed with any dimensions desirable for implantation of any intervertebral space along the spine and, in addition to use as a disc replacement device, are also readily configurable for use with a range of bone-anchored orthopedic prostheses, such as a spinal fusion implant, an interbody spacer, an intervertebral cage, a corpectomy device, hip and knee replacement implants, long bone replacement plates, intramedulary nails and rods, bone fixation plates (such as for fixation of craniomaxillofacial fractures), veterinary implants, and tips for guide wires, and the like.
[0066] The subject matter described above is provided by way of illustration only and should not be construed as limiting. Various modifications and changes may be made to the subject matter described herein without following the example embodiments and applications illustrated and described, and without departing from the true spirit and scope of the present invention, which is set forth in the following claims.
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Disclosed is an implant holder for an implant device comprising a locking mechanism that in a first position causes a clamp coupled to an implant device to lock such that the clamp cannot be decoupled from the implant device, and in a second position causes the clamp to unlock the implant device such that the clamp remains coupled to the implant device in the absence of a sufficient decoupling force but is decoupled from the implant device in the presence of a sufficient decoupling force. Also disclosed are methods of implanting an implant device using an implant holder by coupling the implant device to the implant holder, locking the implant device and the implant holder, emplacing the implant device utilizing the implant holder, unlocking the implant device and the implant holder such that the implant device is still coupled to the implant holder but can be decoupled with sufficient force.
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CROSS-REFERENCE TO RELATED APPLICATIONS
This document, filed under 35 USC 111 and 37 CFR 1.53(b) as a continuation of the United States Patent Application that was filed on Sep. 11, 2008, bearing the title of REFRESHMENT TOWEL AND APPLIED SOLUTION, assigned Ser. No. 12/208,944 and issued as U.S. Pat. No. 8,182,826 on May 22, 2012, which patent claims the benefit of the filing date of the United States Provisional Application for Patent that was filed on Sep. 11, 2007 and assigned Ser. No. 60/971,436
BACKGROUND OF THE INVENTION
It's hot, dang hot! Africa hot! Tarzan couldn't take this kind of heat! This paraphrase of probably the only memorable quote from the movie Biloxi Blues needs no explanation, especially if you have ever tried to accomplish anything outdoors in a southern state in the middle of the summer heat. We have all experienced moments where this quote could be used. Whether on the golf course, sitting in a baseball stadium, sitting on the sidelines while your child is playing soccer, mowing the grass, an outdoor wedding, changing a flat tire, or the like, there are just times that are almost unbearable.
However, if you are an outdoors type of person and you refuse to be imprisoned in your nice air-conditioned home by the summer heat, you most likely have had, and will have, moments when you simply need some relief. People have found themselves in these situations time and time again. Hence, a typical scene in western movies is a sweat drenched, dusty cowboy dunking his head into the horse trough to cool down. This may seem like a refreshing step but, if you have ever raised horses, you will appreciate that a horse trough is certainly no place to be sticking your head. In fact, choosing between the options of a heat stroke or sticking your face into the slimy, grime that floats around in a horse trough is a tough call.
Other, less dramatic techniques have also been employed such as, seeking the shade of a tree, building a fan by folding a piece of paper, putting a cold beverage to your forehead, running through the water sprinklers, retreating to an air-conditioned room, stepping in front of a fan, or wetting a towel to put over the back of your neck.
The human body also has its own solution—sweat glands (or if you are a lady, glow glands). It is well known that as a liquid evaporates, it helps to eradicate heat. This is the purpose of your sweat—it helps to keep your body cool. As sweat evaporates from the surface of your skin, excess heat is removed and as a result, you are cooled. This phenomenon is based on the principle in physics which basically states that a certain amount of heat needs to be applied to a liquid in order for that liquid to evaporate—pass from a liquid form to a vaporous or gaseous form. This amount of heat is referred to as the heat of vaporization. The basis of this principle is that as the heat energy increases the speed of the water molecules also increase. Once the speed of the water molecules reaches a certain speed, they can escape into the air. The heat energy for this process is provided by your body. Thus, the heat used to evaporate sweat is then used up which in turn operates to cool your body down.
This all works quite well in a nice dry environment, however, when you are in a highly humid environment, things begin to break down. First of all, the air in a highly humid environment is already near saturation and thus, cannot absorb much additional water vapor. Thus, the sweat cannot evaporate and you remain hot, and now, a sweaty mess.
The troubles one finds in the heat of the summer don't stop there. First of all, as bacteria on your skin mixes with your sweat, you begin to emit noxious odors. Furthermore, the bugs and insects that once would hit and bounce off of you now have a tendency to hit and stick.
Trying to stay in such conditions is not only a matter of comfort. As salt and sodium exits your body in your sweat, you can quickly dehydrate which can lead to circulatory problems and heat stroke. It is important to ensure that you do not overheat, especially in hot humid environments. Thus, there is a need in the art for a device to assist in the cooling down of an individual.
Because many of the activities that occur outside are athletic in nature, it is not convenient to carry around products typically necessary to help a person stay cool, such as fans, ice, etc. Thus, there is a need in the art for a device that is compact, easy to carry and assists in the cooling down of an individual. Further, corporate and promotional events are often centered around outdoor activities such as a golf tournament, a concert, or a resort. Consequently, there is a need for corporate sponsors to offer their invitees an inexpensive, sanitary, and convenient way to cool off, repel insects, and stay productive while capitalizing on the opportunity to build and enhance brand awareness through a simultaneous dissemination of a trademark, banner, or logo.
Other issues that arise in the summer outdoors can also be a nuisance. For instance, if you go too far south in the state of Georgia, you cross the well known Gnat Line. Below the Gnat Line one is constantly attacked by what some refer to as the Confederate Air Force designed to keep the Yankees away. The fact of the matter is, however, that in the southern states, insects are more prevalent. And to further exasperate matters, most insects, especially gnats, are attracted to moisture. As a result, your sweaty face gets bombarded by a host of gnats. It would be of great benefit to have a device that not only cools a person down but that also could help to alleviate the nuisance from insects. Moreover, while gnats are truly annoying, a device with an insect repellant property is even more desirable when one considers the need to keep more sinister insects at bay, such as mosquitoes, which are prone to carrying and transmitting disease.
In addition, as the world gets educated on the dangers of exposing your skin to the ultraviolet light of the sun, products with an associated Sun Protection Factor (SPF) have grown in popularity. Applying SPF rated products to the skin is imperative if you are working outdoors and prone to getting sunburns. Thus, it would be beneficial for a cooling device to also provide the application of an SPF rated product to the skin.
Part of feeling refreshed obviously includes smelling fresh. Thus, it would be beneficial for a cooling device to also provide a fresh scent to an individual.
Also, because many people have skin prone to drying and cracking, it would be beneficial for a cooling device to provide a means of skin rehydrating and softening.
The various embodiments, features and aspects of the present invention, either by themselves or in conjunction with each other, address each of these needs in the art, as well as other needs in the art as described herein.
BRIEF SUMMARY OF EMBODIMENTS OF THE INVENTION
A refreshment towel with applied solution is an apparatus consisting of a carrying agent, most likely a high quality cotton towel or towelette, that has been saturated with an aqueous solution comprised of various ingredients. The resulting saturated towel can be rubbed on a user's skin such that the aqueous solution that has been absorbed by the towel is transferred. The aqueous solution is specially formulated so that desired sensory results take place when the towel comes in contact with the skin. One aspect of embodiments of the present invention is the aqueous solution, or the specific combinations thereof.
In a preferred embodiment, the specially formulated aqueous solution contains, among other ingredients, a concentration of menthol and alcohol. The presence of the menthol and alcohol creates a cooling sensation to the user when it is applied to the skin. Additionally, menthol and alcohol are well documented as sterilization agents having anti-bacterial properties. Advantageously, a towel soaked in such a solution provides a means of cooling off without having to douse oneself with water, go inside where the air is conditioned, or just shed clothes. Further, the optional inclusion of essential oils and additives, in addition to the menthol and alcohol, can offer additional desirable properties such as sanitation, skin softening and moisturizing, fragrance, invigoration, alertness, relaxation, etc.
Moreover, a quality towel can be weaved, stitched or embroidered to include a logo or other similar decorative items for the purpose of marketing and promotional giveaways. Additionally, embodiments of the invention can be easily packaged and stored until ready for use, after which the remainder is a useful towel or cloth product suited for everyday use.
The uses for the various embodiments of the present invention are virtually limitless and quite varied. Almost universally, anybody in need of physically cooling off can make use of an embodiment of the present invention. Whether a person is just passing the time sitting on the back porch during a hot, balmy summer night, or dug in deep in a foxhole somewhere in the blistering Middle East while serving this great country, the present invention affords a convenient, compact, safe and sanitary way to get some relief from the heat, improve hygiene, or stay alert. Women suffering from “hot flashes” or in the throws of labor, hospital patients in need of physical comfort, missionaries spreading the Gospel in the hot, remote, bug infested corners of the earth, government workers and volunteers working to rebuild disaster areas, men and women of the armed forces exposed to the elements while selflessly defending our freedom, all can benefit from various embodiments of the present invention.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a three dimensional block diagram intended to represent an exploded view of the components making up an exemplary embodiment of the present invention.
FIG. 2 is a block flow chart diagram depicting an exemplary method of manufacture for a typical embodiment of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
The present invention, as well as features and aspects thereof, is directed towards providing a towel, or towelette, that is moistened with a solution which when applied to the body, can help to cool the body, warm the body, refresh the body and provide other beneficial effects as well.
In general, embodiments of the present invention operate to help a subject, such as a person or animal, to stay cool, alert, relaxed, refreshed, and free from, or at least less bothered by, the pestering and biting of insects. In addition, some embodiments of the present invention can be used as promotional items for organizations and businesses to build brand awareness and loyalty by putting their customized logo on the embodiments of the invention, or the packaging thereof, and giving them away after different events and as gifts-awards. Furthermore, embodiments of the present invention have the added benefit of being suitable for other purposes after providing refreshment and cooling to the subject.
More specifically, an exemplary embodiment of the present invention is in the form of a towel or other form of cloth that is soaked in a natural solution. The natural solution includes various ingredients to meet various needs or alleviate various problems. For instance, one embodiment of the present invention may include a carrying agent that is cloth-like in nature and fabricated from natural fibers including, but not limited to, 100% cotton, bamboo fabric, or even a nonwoven material, and saturated or moistened with a specially formulated aqueous solution containing natural products. It should be appreciated that one skilled in the art may choose any material capable of absorbing the aqueous solution, for the purpose of acting as a carrying agent. Once the cloth, or carrying agent, has been saturated with the aforementioned solution, the solution can be applied to a user by simply rubbing the cloth on the skin. Depending on the particular formulation of the aqueous solution, application to the user's skin can operate to perform one or more of the functions in the following non-limiting list:
removing heat calories from the body; cooling the body down; providing a refreshing feeling; soothing a person; helping to awaken or keep a person alert; opening skin pores to enable the body to breathe better and cool more quickly; preventing insects from biting and pestering; moisturizing the skin so that it does not dry out; leaving a fresh scent; cleaning body parts; and/or sanitizing body parts or surfaces.
Preferred embodiments of the present invention employ cotton towels as the carrying agent for the specially formulated aqueous solution. Cotton is a desirable natural fiber for use as the carrying agent because it is readily attainable, all natural, hypoallergenic, absorbent and recyclable. Further, a cotton carrying agent can be kept cool, cold, or frozen. It holds an aqueous solution extremely well and has long term holding ability without degradation. Further, a cotton carrying agent, such as a towel, potentially has long term appeal for usability by an end user as it may be employed for other uses once the aqueous solution it carries has been exhausted. Alternative uses for the towel after its initial purpose is a benefit for such a product when used for promotional purposes. For instance, the towel could be used as a golf towel, a wash cloth, dry towel, etc. Thus, it should be clear that embodiments that use a quality towel actually provide a dual use.
As an alternative to cotton, bamboo fiber is used as a carrying agent in some embodiments of the present invention. One aspect of the present invention when using bamboo fiber as a carrying agent is the added benefit of enhanced absorption capacity. Bamboo has on the order of four times the absorption capacity of cotton and, therefore, is capable of carrying larger quantities of the aqueous solution. Consequently, a carrying agent made of bamboo fiber performs longer for its intended purpose as a carrying agent of the aqueous solution. Further, benefits of bamboo fiber as a carrying agent include the aspect that bamboo fiber has natural anti-bacterial agents useful for sanitation purposes. Also, bamboo affords a user natural UV protection. Advantageously, it is softer than cotton and is comparable in feel to cashmere or silk. In addition, similar to cotton, bamboo is environmentally friendly and a renewable resource. It can be kept cool or frozen. It holds an aqueous solution very well and has long term holding power without degradation. Finally, like cotton, a carrying agent made of bamboo fiber has long term appeal for usability by the end user.
A towel made from natural fibers is the preferred carrying agent for a specially formulated aqueous solution that, when applied to an end user, can operate to impart a desirable sensation or condition. It should be noted that the present invention is not limited to the particular carrying agent, although the particular carrying agent may be considered novel in and of itself. For instance, the carrying agent may even include a nonwoven material, a squeeze bottle, a roll-on type bottle, a moisture stick delivery system such as a deodorant stick, or a spray-on bottle.
One aspect of embodiments of the present invention is the essential oils and liquid mixture, herein called a specially formulated aqueous solution, coupled with a convenient delivery system, that benefit the user wishing to transfer or apply a solution to the skin.
The present invention makes use of a standard foundational mixture from which various embodiments of the specially formulated aqueous solution may be achieved based on subsequent additions of essential oils and other ingredients. The foundational mixture common to most embodiments of the specially formulated aqueous solution is comprised of the following ingredients:
Purified Water 70% to 95% Polysorbate 20 (CAS #9005-64-5) as solubiliser from 3% to 0.005% L-Menthol (CAS #89-78-1) as cooling agent from 4% to 0.005% Ethyl Alcohol (CAS #64-17-5) as solubiliser/cooling agent from 3% to 0.005% Isopropyl Alcohol (CAS #200-661-7) as Denaturant for ethyl alcohol from 3% to 0.005% Peg-6 Caprylic/Capric Glycedires (CAS #127281-18-9) Co-Solubiliser 1.5% to 0.005% Glycerine (CAS #56-81-5) Moisturizer 3% to 0.005% Phenagon PDI (Phenoxyethanol+DMDM Hydantoin+Iodoprophyl Butylcarbamat) Preservative 2.5% to 0.002%
Or
Phenonip (Phenoxyethanol+Methylparabens+Ethylparabens+Prophylparabens+Butylparabens) Preservative 3% to 0.002%
The variations in percent concentrations for the ingredients of the foundational mixture to the aqueous solution are necessary to accommodate choices of subsequent custom additions and carrying agent characteristics. Advantageously, one ingredient of the foundational mixture is a natural moisturizer, glycerine, and serves to offset possible drying effects stemming from the presence of alcohols and menthols used to create cooling sensations or alleviate bacteria. Further, another standard ingredient found in the foundational mixture of the aqueous solution that is a component of the present invention, is a preservative used, advantageously, to give the invention a minimum two year shelf life when stored per the manufacturer's instructions.
Once the foundational mixture has been formulated, additional ingredients are added in order to concoct an aqueous solution designed to deliver specific sensations to an end user. An exemplary formula of these subsequent additions to the foundational mixture includes the following elements:
Lemon Grass Oil (CAS #8007-02-1) Essential oil (insect repellant, and refreshing) 5% to 0.005% Citronella Oil (CAS #8000-29-1) Essential oil (insect repellant, and refreshing) 5% to 0.005% Bergamot Oil (CAS #8000-75-8) Essential oil (invigorating and refreshing) 5% to 0.005% Grapefruit Oil (CAS #8016-20-4) Essential oil (refreshing, cleaning, & fragrance) 5% to 0.003%
The four additional ingredients in the exemplary additive solution outlined immediately above are dissolved in the foundational mixture described prior in order to create a specially formulated aqueous solution. The particular exemplary solution described thus far operates to not only cool an individual when applied to his or her skin (menthol and alcohol), but also to moisturize the skin (glycerine), generate a pleasant fragrance (Lemon Grass Oil, Citronella Oil, Bergamot Oil, Grapefruit Oil), and provide a degree of protection of insects (Lemon Grass Oil, Citronella Oil).
Another aspect of embodiments of the present invention is the relative ease and safety of the application process whereby the specially formulized aqueous solution is transferred from the carrying agent to the skin of the user. Such an aspect is particularly beneficial when considered in light of the exemplary specially formulized aqueous solution described above, which contains elements included as a result of the insect repellent properties. More specifically, because the present invention affords the means to wipe insect repellent on the skin in a targeted fashion, these embodiments of the present invention avoid the need to use c spray-based delivery systems. Advantageously, natural ingredients with insect repellent properties that are used by the present invention can be safely applied to the face in a careful, targeted manner, unlike spray or squirt-based applicators that can cause insect repellent formulas to get into the eyes, ears, nose, and mouth. However, the various aqueous solutions may also be formulated for placement into a spray bottle or other delivery mechanisms if so desired.
Other exemplary mixtures of additive ingredients combined with the foundational formula can create a specially formulated aqueous solution capable of treating a wide number of conditions or providing desirable effects including, but not limited to, relief from hot flashes, relief from sweat flashes, mitigation of foul odor, cleansing and sanitization of skin, changing of mood, and relief from stress. Further, various embodiments of the present invention may employ aqueous solution combinations designed to relax, calm, invigorate, raise awareness, heighten focus, or combat fatigue. Various combinations of the specially formulated aqueous solution component of the present invention may include any one, or a combination of, the elements listed below in addition to the elements outlined in the exemplary formula above:
Peppermint Oil (CAS #68917-18-0) Essential Oil (refreshing and fragrance), 5% to 0.003% Tangerine Oil (CAS #8008-31-9) Essential oil (refreshing, cleaning, & fragrance), 5% to 0.003% Lime Oil (CAS #8008-26-2) Essential oil (refreshing, cleaning, & fragrance), 5% to 0.003% Eucalyptus Citriodora Oil (CAS #8000-48-4) Essential Oil (refreshing, winter time, and fragrance), 4% to 0.003% Eucalyptus Chinese Oil (CAS #68917-18-0 Essential Oil (refreshing, winter time, and fragrance), 4% to 0.003% Grapefruit Oil (CAS #8016-20-4) Essential oil (refreshing, cleaning, & fragrance), 5% to 0.003% Lavender Oil (CAS#008000-28-0) Essential oil (refreshing & fragrance), 5% to 0.002% Lemon Oil (CAS #84929-31-7) Essential oil (refreshing, cleaning, & fragrance), 5% to 0.003% Orange Oil (CAS #8028-48-6) Essential Oil (refreshing, cleaning, & fragrance), 5% to 0.003% Tea Tree Oil (CAS #85085-48-9) Essential oil (refreshing, invigorating & fragrance), 5% to 0.003% Vanilla Oil Essential oil (CAS#008024-06-4) (refreshing, invigorating & fragrance), 5% to 0.003% Green Tea Oil Essential oil (CAS#999999-34-7) (refreshing, invigorating & fragrance), 5% to 0.003% Geranium Oil (CAS #8000-46-2) Essential Oil (refreshing and fragrance), 4% to 0.003% Spearmint Oil (CAS #8007-02-1) Essential oil (refreshing and fragrance), 5% to 0.005% Mandarin Oil (CAS #8008-31-9) Essential oil (refreshing, cleaning, & fragrance), 5% to 0.003% Coconut oil monoglycerides, ethoxylated (CAS#068553-03-7) Synonyms: Glycerides, coco mono-, ethoxylated; Coconut oil monoglycerides, ethoxylated, 5% to 0.003% Coconut diethylamide (CAS #068603-42-9) Synonyms: Coconut diethylamide; Coconut diethanolamide (1); Aldanolamide; Amides, coco, N,N-bis(2-hydroxyethyl); Coconut oil acid diethanolamine, 5% to 0.003% Coconut fatty acids (CAS#061788-47-4) Synonyms: Acids, coconut; Coco fatty acid; Coconut acid; Coconut fatty acids; Coconut oil acids; Fatty acids, coco, 5% to 0.003% Cocoamidopropylbetaine (CAS#061789-40-0) Synonyms: Cocoamidopropyl betaine; N-(Coco alkyl) amido propyl dimethyl betaine; Coconut oil amidopropyl betaine; Quaternary ammonium compounds, (carboxymethyl)3-cocoamidopropyl) dimethyl, hydroxides, inner salts; 1-Propanaminium, 3-amino-N-(carboxymethyl)-N,N-dimethyl-, N-coco acyl derivs., inner salts, 5% to 0.003% Cucumber extract (CAS#089998-01-6) Synonyms: Cucumber extract; Cucumis sativus extract, 5% to 0.003% Vanilla oil/extract (CAS#008024-06-4) Synonyms: Protovanol; Oils, vanilla; Vanilla extract, 5% to 0.003% Green tea (CAS#999999-34-7), 5% to 0.003% Lavender oil (CAS#008000-28-0) Synonyms: Lavender oil; Lavandula officinalis oil; Lavender flowers oil; Oil of lavender; Oils, lavender, 5% to 0.003% Coconut oil, diethanolamine condensate (Surfactant) (CAS#008051-30-7) Synonyms: Surfactants (2); Coconut oil diethanolamine condensate; Coconut oil, reaction products with diethanolamine, 5% to 0.003%
Yet another embodiment of the present invention may include an aqueous solution formulation that contains an ingredient with an associated Sun Protection Factor (SPF) designed to protect a user's skin against UVA and UVB radiation. Because an advantage of the present invention is to cool the body when applied to the skin, it is logical that typical users of the present invention may often be exposed to hot, sunny outdoor conditions. Advantageously, a formulation of the aqueous solution component of the present invention that contains an ingredient with an associated SPF, in addition to the cooling agents, would provide an added bonus of a much needed additional level of protection.
Turning now to the figures in which like references refer to like elements throughout the several views, various aspects and embodiments of the present invention are further described.
FIG. 1 is a three dimensional block diagram intended to represent an exploded view of the present invention in a typical embodiment. As described above, the specially formulized aqueous solution 10 is a combination of the previously outlined foundation mixture in conjunction with additional additives present for desired effects including, but not limited to, insect repellent, SPF quality, and fragrance. The specially formulized aqueous solution 10 is applied to a carrying agent 20 until the carrying agent 20 reaches a point of saturation. Once saturated with the specially formulized aqueous solution 10 , the carrying agent 20 is hermetically sealed in a packaging solution 30 capable of preventing the specially formulized aqueous solution 10 from evaporating out of the carrying agent 20 . In an exemplary embodiment, this packaging can be of superior quality to ensure resistance against evaporation, introduction of bacteria and mold, and operates to provide an extended shelf life. The carrying agent 20 in the preferred embodiment depicted in the figure may be a cloth-like structure constructed of any number of natural fibers including, but not limited to, cellulose, cotton, bamboo, wood products, grass products, or even spray bottles, squeeze bottles, etc. Further, the carrying agent 20 may be of a nonwoven form, a knitted form, a woven form, or any other form known to those skilled in the art of cloth manufacture. It must be appreciated that depending upon the particular formulation of the aqueous solution 10 , the size of the carrying agent 20 , the material of construction for the carrying agent 20 and other specific embodiment factors, the optimum carrying agent 20 gram weight may vary. For example, the preferred range of cloth weight for a woven carrying agent 20 made of cotton and used as a component in the present invention is 22 to 55 grams for a one square foot cloth. The ideal weight, within that range, for the same carrying agent 20 would be roughly 30 grams+/−10%. To further the example, a carrying agent 20 made of cotton that was of a knitted construction and measuring two and a quarter square feet ideally has a weight range of 70 to 85 grams.
Moving now to FIG. 2 , the method of manufacture for the present invention is depicted via a block flow chart. As described prior, typical embodiments of the specially formulated aqueous solutions 10 contain a foundational mixture containing a measure of purified water, polysorbate, 1-menthol, ethyl alcohol, isopropyl alcohol, a moisturizer and preservatives. The preparation 40 of the specially formulated aqueous solution 10 entails combining the foundational mixture with at least one of the essential oils or additives listed prior in this specification. Components in the foundational mixture serve as solvents for the essential oils or additives and enable the creation of the homogenous mixture that is the aqueous solution 10 . Once the aqueous solution 10 has been prepared 40 , it is impregnated 50 into a fibrous cloth carrying agent 20 until the cloth is saturated with the solution 10 . After impregnation 50 of the carrying agent 20 is complete, the product is then sealed 60 in a waterproof package 30 that prevents evaporation of the aqueous solution 10 . The presence of preservatives in the foundational mixture of the aqueous solution 10 combined with the sealed, waterproof packaging 30 provide a means by which the product can be stored for up to two years without degradation of quality. The method is complete when the product is removed 70 from the packaging 30 and applied to the user.
The present invention has been described using detailed descriptions of embodiments thereof that are provided by way of example and are not intended to limit the scope of the invention. The described embodiments comprise different features, not all of which are required in all embodiments of the invention. Some embodiments of the present invention utilize only some of the features or possible combinations of the features. Variations of embodiments of the present invention that are described and embodiments of the present invention comprising different combinations of features noted in the described embodiments will occur to persons of the art.
Further, it will be appreciated by persons skilled in the art that the present invention is not limited by what has been particularly shown and described herein above. Rather, the scope of the invention is defined by the claims that follow.
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A refreshment towel with applied solution is an apparatus consisting of a carrying agent, most likely a high quality cotton towel or towelette, that has been saturated with an aqueous solution comprised of various ingredients. The resulting saturated towel can be rubbed on a user's skin such that the aqueous solution that has been absorbed by the towel is transferred. The aqueous solution is compounded specifically to provide cooling, insect repellant, sun protection, freshness, cleansing and other uses. More specifically, the aqueous solution is specially formulated so that desired sensory results take place when the towel comes in contact with the skin.
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